xref: /vim-8.2.3635/src/eval.c (revision dabfde04)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * eval.c: Expression evaluation.
12  */
13 #define USING_FLOAT_STUFF
14 
15 #include "vim.h"
16 
17 #if defined(FEAT_EVAL) || defined(PROTO)
18 
19 #ifdef VMS
20 # include <float.h>
21 #endif
22 
23 #define DICT_MAXNEST 100	/* maximum nesting of lists and dicts */
24 
25 static char *e_letunexp	= N_("E18: Unexpected characters in :let");
26 static char *e_undefvar = N_("E121: Undefined variable: %s");
27 static char *e_missbrac = N_("E111: Missing ']'");
28 static char *e_dictrange = N_("E719: Cannot use [:] with a Dictionary");
29 static char *e_letwrong = N_("E734: Wrong variable type for %s=");
30 static char *e_illvar = N_("E461: Illegal variable name: %s");
31 #ifdef FEAT_FLOAT
32 static char *e_float_as_string = N_("E806: using Float as a String");
33 #endif
34 
35 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
36 
37 static dictitem_T	globvars_var;		/* variable used for g: */
38 #define globvarht globvardict.dv_hashtab
39 
40 /*
41  * Old Vim variables such as "v:version" are also available without the "v:".
42  * Also in functions.  We need a special hashtable for them.
43  */
44 static hashtab_T	compat_hashtab;
45 
46 /*
47  * When recursively copying lists and dicts we need to remember which ones we
48  * have done to avoid endless recursiveness.  This unique ID is used for that.
49  * The last bit is used for previous_funccal, ignored when comparing.
50  */
51 static int current_copyID = 0;
52 
53 /*
54  * Array to hold the hashtab with variables local to each sourced script.
55  * Each item holds a variable (nameless) that points to the dict_T.
56  */
57 typedef struct
58 {
59     dictitem_T	sv_var;
60     dict_T	sv_dict;
61 } scriptvar_T;
62 
63 static garray_T	    ga_scripts = {0, 0, sizeof(scriptvar_T *), 4, NULL};
64 #define SCRIPT_SV(id) (((scriptvar_T **)ga_scripts.ga_data)[(id) - 1])
65 #define SCRIPT_VARS(id) (SCRIPT_SV(id)->sv_dict.dv_hashtab)
66 
67 static int echo_attr = 0;   /* attributes used for ":echo" */
68 
69 /* The names of packages that once were loaded are remembered. */
70 static garray_T		ga_loaded = {0, 0, sizeof(char_u *), 4, NULL};
71 
72 /*
73  * Info used by a ":for" loop.
74  */
75 typedef struct
76 {
77     int		fi_semicolon;	/* TRUE if ending in '; var]' */
78     int		fi_varcount;	/* nr of variables in the list */
79     listwatch_T	fi_lw;		/* keep an eye on the item used. */
80     list_T	*fi_list;	/* list being used */
81     int		fi_bi;		/* index of blob */
82     blob_T	*fi_blob;	/* blob being used */
83 } forinfo_T;
84 
85 
86 /*
87  * Array to hold the value of v: variables.
88  * The value is in a dictitem, so that it can also be used in the v: scope.
89  * The reason to use this table anyway is for very quick access to the
90  * variables with the VV_ defines.
91  */
92 
93 /* values for vv_flags: */
94 #define VV_COMPAT	1	/* compatible, also used without "v:" */
95 #define VV_RO		2	/* read-only */
96 #define VV_RO_SBX	4	/* read-only in the sandbox */
97 
98 #define VV_NAME(s, t)	s, {{t, 0, {0}}, 0, {0}}
99 
100 static struct vimvar
101 {
102     char	*vv_name;	/* name of variable, without v: */
103     dictitem16_T vv_di;		/* value and name for key (max 16 chars!) */
104     char	vv_flags;	/* VV_COMPAT, VV_RO, VV_RO_SBX */
105 } vimvars[VV_LEN] =
106 {
107     /*
108      * The order here must match the VV_ defines in vim.h!
109      * Initializing a union does not work, leave tv.vval empty to get zero's.
110      */
111     {VV_NAME("count",		 VAR_NUMBER), VV_COMPAT+VV_RO},
112     {VV_NAME("count1",		 VAR_NUMBER), VV_RO},
113     {VV_NAME("prevcount",	 VAR_NUMBER), VV_RO},
114     {VV_NAME("errmsg",		 VAR_STRING), VV_COMPAT},
115     {VV_NAME("warningmsg",	 VAR_STRING), 0},
116     {VV_NAME("statusmsg",	 VAR_STRING), 0},
117     {VV_NAME("shell_error",	 VAR_NUMBER), VV_COMPAT+VV_RO},
118     {VV_NAME("this_session",	 VAR_STRING), VV_COMPAT},
119     {VV_NAME("version",		 VAR_NUMBER), VV_COMPAT+VV_RO},
120     {VV_NAME("lnum",		 VAR_NUMBER), VV_RO_SBX},
121     {VV_NAME("termresponse",	 VAR_STRING), VV_RO},
122     {VV_NAME("fname",		 VAR_STRING), VV_RO},
123     {VV_NAME("lang",		 VAR_STRING), VV_RO},
124     {VV_NAME("lc_time",		 VAR_STRING), VV_RO},
125     {VV_NAME("ctype",		 VAR_STRING), VV_RO},
126     {VV_NAME("charconvert_from", VAR_STRING), VV_RO},
127     {VV_NAME("charconvert_to",	 VAR_STRING), VV_RO},
128     {VV_NAME("fname_in",	 VAR_STRING), VV_RO},
129     {VV_NAME("fname_out",	 VAR_STRING), VV_RO},
130     {VV_NAME("fname_new",	 VAR_STRING), VV_RO},
131     {VV_NAME("fname_diff",	 VAR_STRING), VV_RO},
132     {VV_NAME("cmdarg",		 VAR_STRING), VV_RO},
133     {VV_NAME("foldstart",	 VAR_NUMBER), VV_RO_SBX},
134     {VV_NAME("foldend",		 VAR_NUMBER), VV_RO_SBX},
135     {VV_NAME("folddashes",	 VAR_STRING), VV_RO_SBX},
136     {VV_NAME("foldlevel",	 VAR_NUMBER), VV_RO_SBX},
137     {VV_NAME("progname",	 VAR_STRING), VV_RO},
138     {VV_NAME("servername",	 VAR_STRING), VV_RO},
139     {VV_NAME("dying",		 VAR_NUMBER), VV_RO},
140     {VV_NAME("exception",	 VAR_STRING), VV_RO},
141     {VV_NAME("throwpoint",	 VAR_STRING), VV_RO},
142     {VV_NAME("register",	 VAR_STRING), VV_RO},
143     {VV_NAME("cmdbang",		 VAR_NUMBER), VV_RO},
144     {VV_NAME("insertmode",	 VAR_STRING), VV_RO},
145     {VV_NAME("val",		 VAR_UNKNOWN), VV_RO},
146     {VV_NAME("key",		 VAR_UNKNOWN), VV_RO},
147     {VV_NAME("profiling",	 VAR_NUMBER), VV_RO},
148     {VV_NAME("fcs_reason",	 VAR_STRING), VV_RO},
149     {VV_NAME("fcs_choice",	 VAR_STRING), 0},
150     {VV_NAME("beval_bufnr",	 VAR_NUMBER), VV_RO},
151     {VV_NAME("beval_winnr",	 VAR_NUMBER), VV_RO},
152     {VV_NAME("beval_winid",	 VAR_NUMBER), VV_RO},
153     {VV_NAME("beval_lnum",	 VAR_NUMBER), VV_RO},
154     {VV_NAME("beval_col",	 VAR_NUMBER), VV_RO},
155     {VV_NAME("beval_text",	 VAR_STRING), VV_RO},
156     {VV_NAME("scrollstart",	 VAR_STRING), 0},
157     {VV_NAME("swapname",	 VAR_STRING), VV_RO},
158     {VV_NAME("swapchoice",	 VAR_STRING), 0},
159     {VV_NAME("swapcommand",	 VAR_STRING), VV_RO},
160     {VV_NAME("char",		 VAR_STRING), 0},
161     {VV_NAME("mouse_win",	 VAR_NUMBER), 0},
162     {VV_NAME("mouse_winid",	 VAR_NUMBER), 0},
163     {VV_NAME("mouse_lnum",	 VAR_NUMBER), 0},
164     {VV_NAME("mouse_col",	 VAR_NUMBER), 0},
165     {VV_NAME("operator",	 VAR_STRING), VV_RO},
166     {VV_NAME("searchforward",	 VAR_NUMBER), 0},
167     {VV_NAME("hlsearch",	 VAR_NUMBER), 0},
168     {VV_NAME("oldfiles",	 VAR_LIST), 0},
169     {VV_NAME("windowid",	 VAR_NUMBER), VV_RO},
170     {VV_NAME("progpath",	 VAR_STRING), VV_RO},
171     {VV_NAME("completed_item",	 VAR_DICT), VV_RO},
172     {VV_NAME("option_new",	 VAR_STRING), VV_RO},
173     {VV_NAME("option_old",	 VAR_STRING), VV_RO},
174     {VV_NAME("option_type",	 VAR_STRING), VV_RO},
175     {VV_NAME("errors",		 VAR_LIST), 0},
176     {VV_NAME("false",		 VAR_SPECIAL), VV_RO},
177     {VV_NAME("true",		 VAR_SPECIAL), VV_RO},
178     {VV_NAME("null",		 VAR_SPECIAL), VV_RO},
179     {VV_NAME("none",		 VAR_SPECIAL), VV_RO},
180     {VV_NAME("vim_did_enter",	 VAR_NUMBER), VV_RO},
181     {VV_NAME("testing",		 VAR_NUMBER), 0},
182     {VV_NAME("t_number",	 VAR_NUMBER), VV_RO},
183     {VV_NAME("t_string",	 VAR_NUMBER), VV_RO},
184     {VV_NAME("t_func",		 VAR_NUMBER), VV_RO},
185     {VV_NAME("t_list",		 VAR_NUMBER), VV_RO},
186     {VV_NAME("t_dict",		 VAR_NUMBER), VV_RO},
187     {VV_NAME("t_float",		 VAR_NUMBER), VV_RO},
188     {VV_NAME("t_bool",		 VAR_NUMBER), VV_RO},
189     {VV_NAME("t_none",		 VAR_NUMBER), VV_RO},
190     {VV_NAME("t_job",		 VAR_NUMBER), VV_RO},
191     {VV_NAME("t_channel",	 VAR_NUMBER), VV_RO},
192     {VV_NAME("t_blob",		 VAR_NUMBER), VV_RO},
193     {VV_NAME("termrfgresp",	 VAR_STRING), VV_RO},
194     {VV_NAME("termrbgresp",	 VAR_STRING), VV_RO},
195     {VV_NAME("termu7resp",	 VAR_STRING), VV_RO},
196     {VV_NAME("termstyleresp",	VAR_STRING), VV_RO},
197     {VV_NAME("termblinkresp",	VAR_STRING), VV_RO},
198     {VV_NAME("event",		VAR_DICT), VV_RO},
199 };
200 
201 /* shorthand */
202 #define vv_type		vv_di.di_tv.v_type
203 #define vv_nr		vv_di.di_tv.vval.v_number
204 #define vv_float	vv_di.di_tv.vval.v_float
205 #define vv_str		vv_di.di_tv.vval.v_string
206 #define vv_list		vv_di.di_tv.vval.v_list
207 #define vv_dict		vv_di.di_tv.vval.v_dict
208 #define vv_blob		vv_di.di_tv.vval.v_blob
209 #define vv_tv		vv_di.di_tv
210 
211 static dictitem_T	vimvars_var;		/* variable used for v: */
212 #define vimvarht  vimvardict.dv_hashtab
213 
214 static int ex_let_vars(char_u *arg, typval_T *tv, int copy, int semicolon, int var_count, char_u *nextchars);
215 static char_u *skip_var_list(char_u *arg, int *var_count, int *semicolon);
216 static char_u *skip_var_one(char_u *arg);
217 static void list_glob_vars(int *first);
218 static void list_buf_vars(int *first);
219 static void list_win_vars(int *first);
220 static void list_tab_vars(int *first);
221 static void list_vim_vars(int *first);
222 static void list_script_vars(int *first);
223 static char_u *list_arg_vars(exarg_T *eap, char_u *arg, int *first);
224 static char_u *ex_let_one(char_u *arg, typval_T *tv, int copy, char_u *endchars, char_u *op);
225 static void set_var_lval(lval_T *lp, char_u *endp, typval_T *rettv, int copy, char_u *op);
226 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
227 static void ex_unletlock(exarg_T *eap, char_u *argstart, int deep);
228 static int do_unlet_var(lval_T *lp, char_u *name_end, int forceit);
229 static int do_lock_var(lval_T *lp, char_u *name_end, int deep, int lock);
230 static void item_lock(typval_T *tv, int deep, int lock);
231 
232 static int eval2(char_u **arg, typval_T *rettv, int evaluate);
233 static int eval3(char_u **arg, typval_T *rettv, int evaluate);
234 static int eval4(char_u **arg, typval_T *rettv, int evaluate);
235 static int eval5(char_u **arg, typval_T *rettv, int evaluate);
236 static int eval6(char_u **arg, typval_T *rettv, int evaluate, int want_string);
237 static int eval7(char_u **arg, typval_T *rettv, int evaluate, int want_string);
238 
239 static int get_string_tv(char_u **arg, typval_T *rettv, int evaluate);
240 static int get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate);
241 static int free_unref_items(int copyID);
242 static int get_env_tv(char_u **arg, typval_T *rettv, int evaluate);
243 static int get_env_len(char_u **arg);
244 static char_u * make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
245 static void check_vars(char_u *name, int len);
246 static typval_T *alloc_string_tv(char_u *string);
247 static void delete_var(hashtab_T *ht, hashitem_T *hi);
248 static void list_one_var(dictitem_T *v, char *prefix, int *first);
249 static void list_one_var_a(char *prefix, char_u *name, int type, char_u *string, int *first);
250 static int tv_check_lock(typval_T *tv, char_u *name, int use_gettext);
251 static char_u *find_option_end(char_u **arg, int *opt_flags);
252 
253 /* for VIM_VERSION_ defines */
254 #include "version.h"
255 
256 /*
257  * Return "n1" divided by "n2", taking care of dividing by zero.
258  */
259 	static varnumber_T
260 num_divide(varnumber_T n1, varnumber_T n2)
261 {
262     varnumber_T	result;
263 
264     if (n2 == 0)	// give an error message?
265     {
266 	if (n1 == 0)
267 	    result = VARNUM_MIN; // similar to NaN
268 	else if (n1 < 0)
269 	    result = -VARNUM_MAX;
270 	else
271 	    result = VARNUM_MAX;
272     }
273     else
274 	result = n1 / n2;
275 
276     return result;
277 }
278 
279 /*
280  * Return "n1" modulus "n2", taking care of dividing by zero.
281  */
282 	static varnumber_T
283 num_modulus(varnumber_T n1, varnumber_T n2)
284 {
285     // Give an error when n2 is 0?
286     return (n2 == 0) ? 0 : (n1 % n2);
287 }
288 
289 
290 #if defined(EBCDIC) || defined(PROTO)
291 /*
292  * Compare struct fst by function name.
293  */
294     static int
295 compare_func_name(const void *s1, const void *s2)
296 {
297     struct fst *p1 = (struct fst *)s1;
298     struct fst *p2 = (struct fst *)s2;
299 
300     return STRCMP(p1->f_name, p2->f_name);
301 }
302 
303 /*
304  * Sort the function table by function name.
305  * The sorting of the table above is ASCII dependent.
306  * On machines using EBCDIC we have to sort it.
307  */
308     static void
309 sortFunctions(void)
310 {
311     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
312 
313     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
314 }
315 #endif
316 
317 
318 /*
319  * Initialize the global and v: variables.
320  */
321     void
322 eval_init(void)
323 {
324     int		    i;
325     struct vimvar   *p;
326 
327     init_var_dict(&globvardict, &globvars_var, VAR_DEF_SCOPE);
328     init_var_dict(&vimvardict, &vimvars_var, VAR_SCOPE);
329     vimvardict.dv_lock = VAR_FIXED;
330     hash_init(&compat_hashtab);
331     func_init();
332 
333     for (i = 0; i < VV_LEN; ++i)
334     {
335 	p = &vimvars[i];
336 	if (STRLEN(p->vv_name) > 16)
337 	{
338 	    iemsg("INTERNAL: name too long, increase size of dictitem16_T");
339 	    getout(1);
340 	}
341 	STRCPY(p->vv_di.di_key, p->vv_name);
342 	if (p->vv_flags & VV_RO)
343 	    p->vv_di.di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
344 	else if (p->vv_flags & VV_RO_SBX)
345 	    p->vv_di.di_flags = DI_FLAGS_RO_SBX | DI_FLAGS_FIX;
346 	else
347 	    p->vv_di.di_flags = DI_FLAGS_FIX;
348 
349 	/* add to v: scope dict, unless the value is not always available */
350 	if (p->vv_type != VAR_UNKNOWN)
351 	    hash_add(&vimvarht, p->vv_di.di_key);
352 	if (p->vv_flags & VV_COMPAT)
353 	    /* add to compat scope dict */
354 	    hash_add(&compat_hashtab, p->vv_di.di_key);
355     }
356     vimvars[VV_VERSION].vv_nr = VIM_VERSION_100;
357 
358     set_vim_var_nr(VV_SEARCHFORWARD, 1L);
359     set_vim_var_nr(VV_HLSEARCH, 1L);
360     set_vim_var_dict(VV_COMPLETED_ITEM, dict_alloc_lock(VAR_FIXED));
361     set_vim_var_list(VV_ERRORS, list_alloc());
362     set_vim_var_dict(VV_EVENT, dict_alloc_lock(VAR_FIXED));
363 
364     set_vim_var_nr(VV_FALSE, VVAL_FALSE);
365     set_vim_var_nr(VV_TRUE, VVAL_TRUE);
366     set_vim_var_nr(VV_NONE, VVAL_NONE);
367     set_vim_var_nr(VV_NULL, VVAL_NULL);
368 
369     set_vim_var_nr(VV_TYPE_NUMBER,  VAR_TYPE_NUMBER);
370     set_vim_var_nr(VV_TYPE_STRING,  VAR_TYPE_STRING);
371     set_vim_var_nr(VV_TYPE_FUNC,    VAR_TYPE_FUNC);
372     set_vim_var_nr(VV_TYPE_LIST,    VAR_TYPE_LIST);
373     set_vim_var_nr(VV_TYPE_DICT,    VAR_TYPE_DICT);
374     set_vim_var_nr(VV_TYPE_FLOAT,   VAR_TYPE_FLOAT);
375     set_vim_var_nr(VV_TYPE_BOOL,    VAR_TYPE_BOOL);
376     set_vim_var_nr(VV_TYPE_NONE,    VAR_TYPE_NONE);
377     set_vim_var_nr(VV_TYPE_JOB,     VAR_TYPE_JOB);
378     set_vim_var_nr(VV_TYPE_CHANNEL, VAR_TYPE_CHANNEL);
379     set_vim_var_nr(VV_TYPE_BLOB,    VAR_TYPE_BLOB);
380 
381     set_reg_var(0);  /* default for v:register is not 0 but '"' */
382 
383 #ifdef EBCDIC
384     /*
385      * Sort the function table, to enable binary search.
386      */
387     sortFunctions();
388 #endif
389 }
390 
391 #if defined(EXITFREE) || defined(PROTO)
392     void
393 eval_clear(void)
394 {
395     int		    i;
396     struct vimvar   *p;
397 
398     for (i = 0; i < VV_LEN; ++i)
399     {
400 	p = &vimvars[i];
401 	if (p->vv_di.di_tv.v_type == VAR_STRING)
402 	    VIM_CLEAR(p->vv_str);
403 	else if (p->vv_di.di_tv.v_type == VAR_LIST)
404 	{
405 	    list_unref(p->vv_list);
406 	    p->vv_list = NULL;
407 	}
408     }
409     hash_clear(&vimvarht);
410     hash_init(&vimvarht);  /* garbage_collect() will access it */
411     hash_clear(&compat_hashtab);
412 
413     free_scriptnames();
414 # if defined(FEAT_CMDL_COMPL)
415     free_locales();
416 # endif
417 
418     /* global variables */
419     vars_clear(&globvarht);
420 
421     /* autoloaded script names */
422     ga_clear_strings(&ga_loaded);
423 
424     /* Script-local variables. First clear all the variables and in a second
425      * loop free the scriptvar_T, because a variable in one script might hold
426      * a reference to the whole scope of another script. */
427     for (i = 1; i <= ga_scripts.ga_len; ++i)
428 	vars_clear(&SCRIPT_VARS(i));
429     for (i = 1; i <= ga_scripts.ga_len; ++i)
430 	vim_free(SCRIPT_SV(i));
431     ga_clear(&ga_scripts);
432 
433     /* unreferenced lists and dicts */
434     (void)garbage_collect(FALSE);
435 
436     /* functions */
437     free_all_functions();
438 }
439 #endif
440 
441 
442 /*
443  * Set an internal variable to a string value. Creates the variable if it does
444  * not already exist.
445  */
446     void
447 set_internal_string_var(char_u *name, char_u *value)
448 {
449     char_u	*val;
450     typval_T	*tvp;
451 
452     val = vim_strsave(value);
453     if (val != NULL)
454     {
455 	tvp = alloc_string_tv(val);
456 	if (tvp != NULL)
457 	{
458 	    set_var(name, tvp, FALSE);
459 	    free_tv(tvp);
460 	}
461     }
462 }
463 
464 static lval_T	*redir_lval = NULL;
465 #define EVALCMD_BUSY (redir_lval == (lval_T *)&redir_lval)
466 static garray_T redir_ga;	/* only valid when redir_lval is not NULL */
467 static char_u	*redir_endp = NULL;
468 static char_u	*redir_varname = NULL;
469 
470 /*
471  * Start recording command output to a variable
472  * When "append" is TRUE append to an existing variable.
473  * Returns OK if successfully completed the setup.  FAIL otherwise.
474  */
475     int
476 var_redir_start(char_u *name, int append)
477 {
478     int		save_emsg;
479     int		err;
480     typval_T	tv;
481 
482     /* Catch a bad name early. */
483     if (!eval_isnamec1(*name))
484     {
485 	emsg(_(e_invarg));
486 	return FAIL;
487     }
488 
489     /* Make a copy of the name, it is used in redir_lval until redir ends. */
490     redir_varname = vim_strsave(name);
491     if (redir_varname == NULL)
492 	return FAIL;
493 
494     redir_lval = (lval_T *)alloc_clear((unsigned)sizeof(lval_T));
495     if (redir_lval == NULL)
496     {
497 	var_redir_stop();
498 	return FAIL;
499     }
500 
501     /* The output is stored in growarray "redir_ga" until redirection ends. */
502     ga_init2(&redir_ga, (int)sizeof(char), 500);
503 
504     /* Parse the variable name (can be a dict or list entry). */
505     redir_endp = get_lval(redir_varname, NULL, redir_lval, FALSE, FALSE, 0,
506 							     FNE_CHECK_START);
507     if (redir_endp == NULL || redir_lval->ll_name == NULL || *redir_endp != NUL)
508     {
509 	clear_lval(redir_lval);
510 	if (redir_endp != NULL && *redir_endp != NUL)
511 	    /* Trailing characters are present after the variable name */
512 	    emsg(_(e_trailing));
513 	else
514 	    emsg(_(e_invarg));
515 	redir_endp = NULL;  /* don't store a value, only cleanup */
516 	var_redir_stop();
517 	return FAIL;
518     }
519 
520     /* check if we can write to the variable: set it to or append an empty
521      * string */
522     save_emsg = did_emsg;
523     did_emsg = FALSE;
524     tv.v_type = VAR_STRING;
525     tv.vval.v_string = (char_u *)"";
526     if (append)
527 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, (char_u *)".");
528     else
529 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, (char_u *)"=");
530     clear_lval(redir_lval);
531     err = did_emsg;
532     did_emsg |= save_emsg;
533     if (err)
534     {
535 	redir_endp = NULL;  /* don't store a value, only cleanup */
536 	var_redir_stop();
537 	return FAIL;
538     }
539 
540     return OK;
541 }
542 
543 /*
544  * Append "value[value_len]" to the variable set by var_redir_start().
545  * The actual appending is postponed until redirection ends, because the value
546  * appended may in fact be the string we write to, changing it may cause freed
547  * memory to be used:
548  *   :redir => foo
549  *   :let foo
550  *   :redir END
551  */
552     void
553 var_redir_str(char_u *value, int value_len)
554 {
555     int		len;
556 
557     if (redir_lval == NULL)
558 	return;
559 
560     if (value_len == -1)
561 	len = (int)STRLEN(value);	/* Append the entire string */
562     else
563 	len = value_len;		/* Append only "value_len" characters */
564 
565     if (ga_grow(&redir_ga, len) == OK)
566     {
567 	mch_memmove((char *)redir_ga.ga_data + redir_ga.ga_len, value, len);
568 	redir_ga.ga_len += len;
569     }
570     else
571 	var_redir_stop();
572 }
573 
574 /*
575  * Stop redirecting command output to a variable.
576  * Frees the allocated memory.
577  */
578     void
579 var_redir_stop(void)
580 {
581     typval_T	tv;
582 
583     if (EVALCMD_BUSY)
584     {
585 	redir_lval = NULL;
586 	return;
587     }
588 
589     if (redir_lval != NULL)
590     {
591 	/* If there was no error: assign the text to the variable. */
592 	if (redir_endp != NULL)
593 	{
594 	    ga_append(&redir_ga, NUL);  /* Append the trailing NUL. */
595 	    tv.v_type = VAR_STRING;
596 	    tv.vval.v_string = redir_ga.ga_data;
597 	    /* Call get_lval() again, if it's inside a Dict or List it may
598 	     * have changed. */
599 	    redir_endp = get_lval(redir_varname, NULL, redir_lval,
600 					FALSE, FALSE, 0, FNE_CHECK_START);
601 	    if (redir_endp != NULL && redir_lval->ll_name != NULL)
602 		set_var_lval(redir_lval, redir_endp, &tv, FALSE, (char_u *)".");
603 	    clear_lval(redir_lval);
604 	}
605 
606 	/* free the collected output */
607 	VIM_CLEAR(redir_ga.ga_data);
608 
609 	VIM_CLEAR(redir_lval);
610     }
611     VIM_CLEAR(redir_varname);
612 }
613 
614     int
615 eval_charconvert(
616     char_u	*enc_from,
617     char_u	*enc_to,
618     char_u	*fname_from,
619     char_u	*fname_to)
620 {
621     int		err = FALSE;
622 
623     set_vim_var_string(VV_CC_FROM, enc_from, -1);
624     set_vim_var_string(VV_CC_TO, enc_to, -1);
625     set_vim_var_string(VV_FNAME_IN, fname_from, -1);
626     set_vim_var_string(VV_FNAME_OUT, fname_to, -1);
627     if (eval_to_bool(p_ccv, &err, NULL, FALSE))
628 	err = TRUE;
629     set_vim_var_string(VV_CC_FROM, NULL, -1);
630     set_vim_var_string(VV_CC_TO, NULL, -1);
631     set_vim_var_string(VV_FNAME_IN, NULL, -1);
632     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
633 
634     if (err)
635 	return FAIL;
636     return OK;
637 }
638 
639 # if defined(FEAT_POSTSCRIPT) || defined(PROTO)
640     int
641 eval_printexpr(char_u *fname, char_u *args)
642 {
643     int		err = FALSE;
644 
645     set_vim_var_string(VV_FNAME_IN, fname, -1);
646     set_vim_var_string(VV_CMDARG, args, -1);
647     if (eval_to_bool(p_pexpr, &err, NULL, FALSE))
648 	err = TRUE;
649     set_vim_var_string(VV_FNAME_IN, NULL, -1);
650     set_vim_var_string(VV_CMDARG, NULL, -1);
651 
652     if (err)
653     {
654 	mch_remove(fname);
655 	return FAIL;
656     }
657     return OK;
658 }
659 # endif
660 
661 # if defined(FEAT_DIFF) || defined(PROTO)
662     void
663 eval_diff(
664     char_u	*origfile,
665     char_u	*newfile,
666     char_u	*outfile)
667 {
668     int		err = FALSE;
669 
670     set_vim_var_string(VV_FNAME_IN, origfile, -1);
671     set_vim_var_string(VV_FNAME_NEW, newfile, -1);
672     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
673     (void)eval_to_bool(p_dex, &err, NULL, FALSE);
674     set_vim_var_string(VV_FNAME_IN, NULL, -1);
675     set_vim_var_string(VV_FNAME_NEW, NULL, -1);
676     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
677 }
678 
679     void
680 eval_patch(
681     char_u	*origfile,
682     char_u	*difffile,
683     char_u	*outfile)
684 {
685     int		err;
686 
687     set_vim_var_string(VV_FNAME_IN, origfile, -1);
688     set_vim_var_string(VV_FNAME_DIFF, difffile, -1);
689     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
690     (void)eval_to_bool(p_pex, &err, NULL, FALSE);
691     set_vim_var_string(VV_FNAME_IN, NULL, -1);
692     set_vim_var_string(VV_FNAME_DIFF, NULL, -1);
693     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
694 }
695 # endif
696 
697 /*
698  * Top level evaluation function, returning a boolean.
699  * Sets "error" to TRUE if there was an error.
700  * Return TRUE or FALSE.
701  */
702     int
703 eval_to_bool(
704     char_u	*arg,
705     int		*error,
706     char_u	**nextcmd,
707     int		skip)	    /* only parse, don't execute */
708 {
709     typval_T	tv;
710     varnumber_T	retval = FALSE;
711 
712     if (skip)
713 	++emsg_skip;
714     if (eval0(arg, &tv, nextcmd, !skip) == FAIL)
715 	*error = TRUE;
716     else
717     {
718 	*error = FALSE;
719 	if (!skip)
720 	{
721 	    retval = (tv_get_number_chk(&tv, error) != 0);
722 	    clear_tv(&tv);
723 	}
724     }
725     if (skip)
726 	--emsg_skip;
727 
728     return (int)retval;
729 }
730 
731 /*
732  * Call eval1() and give an error message if not done at a lower level.
733  */
734     static int
735 eval1_emsg(char_u **arg, typval_T *rettv, int evaluate)
736 {
737     char_u	*start = *arg;
738     int		ret;
739     int		did_emsg_before = did_emsg;
740     int		called_emsg_before = called_emsg;
741 
742     ret = eval1(arg, rettv, evaluate);
743     if (ret == FAIL)
744     {
745 	// Report the invalid expression unless the expression evaluation has
746 	// been cancelled due to an aborting error, an interrupt, or an
747 	// exception, or we already gave a more specific error.
748 	// Also check called_emsg for when using assert_fails().
749 	if (!aborting() && did_emsg == did_emsg_before
750 					  && called_emsg == called_emsg_before)
751 	    semsg(_(e_invexpr2), start);
752     }
753     return ret;
754 }
755 
756     int
757 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
758 {
759     char_u	*s;
760     int		dummy;
761     char_u	buf[NUMBUFLEN];
762 
763     if (expr->v_type == VAR_FUNC)
764     {
765 	s = expr->vval.v_string;
766 	if (s == NULL || *s == NUL)
767 	    return FAIL;
768 	if (call_func(s, -1, rettv, argc, argv, NULL,
769 				     0L, 0L, &dummy, TRUE, NULL, NULL) == FAIL)
770 	    return FAIL;
771     }
772     else if (expr->v_type == VAR_PARTIAL)
773     {
774 	partial_T   *partial = expr->vval.v_partial;
775 
776 	s = partial_name(partial);
777 	if (s == NULL || *s == NUL)
778 	    return FAIL;
779 	if (call_func(s, -1, rettv, argc, argv, NULL,
780 				  0L, 0L, &dummy, TRUE, partial, NULL) == FAIL)
781 	    return FAIL;
782     }
783     else
784     {
785 	s = tv_get_string_buf_chk(expr, buf);
786 	if (s == NULL)
787 	    return FAIL;
788 	s = skipwhite(s);
789 	if (eval1_emsg(&s, rettv, TRUE) == FAIL)
790 	    return FAIL;
791 	if (*s != NUL)  /* check for trailing chars after expr */
792 	{
793 	    clear_tv(rettv);
794 	    semsg(_(e_invexpr2), s);
795 	    return FAIL;
796 	}
797     }
798     return OK;
799 }
800 
801 /*
802  * Like eval_to_bool() but using a typval_T instead of a string.
803  * Works for string, funcref and partial.
804  */
805     int
806 eval_expr_to_bool(typval_T *expr, int *error)
807 {
808     typval_T	rettv;
809     int		res;
810 
811     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
812     {
813 	*error = TRUE;
814 	return FALSE;
815     }
816     res = (tv_get_number_chk(&rettv, error) != 0);
817     clear_tv(&rettv);
818     return res;
819 }
820 
821 /*
822  * Top level evaluation function, returning a string.  If "skip" is TRUE,
823  * only parsing to "nextcmd" is done, without reporting errors.  Return
824  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
825  */
826     char_u *
827 eval_to_string_skip(
828     char_u	*arg,
829     char_u	**nextcmd,
830     int		skip)	    /* only parse, don't execute */
831 {
832     typval_T	tv;
833     char_u	*retval;
834 
835     if (skip)
836 	++emsg_skip;
837     if (eval0(arg, &tv, nextcmd, !skip) == FAIL || skip)
838 	retval = NULL;
839     else
840     {
841 	retval = vim_strsave(tv_get_string(&tv));
842 	clear_tv(&tv);
843     }
844     if (skip)
845 	--emsg_skip;
846 
847     return retval;
848 }
849 
850 /*
851  * Skip over an expression at "*pp".
852  * Return FAIL for an error, OK otherwise.
853  */
854     int
855 skip_expr(char_u **pp)
856 {
857     typval_T	rettv;
858 
859     *pp = skipwhite(*pp);
860     return eval1(pp, &rettv, FALSE);
861 }
862 
863 /*
864  * Top level evaluation function, returning a string.
865  * When "convert" is TRUE convert a List into a sequence of lines and convert
866  * a Float to a String.
867  * Return pointer to allocated memory, or NULL for failure.
868  */
869     char_u *
870 eval_to_string(
871     char_u	*arg,
872     char_u	**nextcmd,
873     int		convert)
874 {
875     typval_T	tv;
876     char_u	*retval;
877     garray_T	ga;
878 #ifdef FEAT_FLOAT
879     char_u	numbuf[NUMBUFLEN];
880 #endif
881 
882     if (eval0(arg, &tv, nextcmd, TRUE) == FAIL)
883 	retval = NULL;
884     else
885     {
886 	if (convert && tv.v_type == VAR_LIST)
887 	{
888 	    ga_init2(&ga, (int)sizeof(char), 80);
889 	    if (tv.vval.v_list != NULL)
890 	    {
891 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
892 		if (tv.vval.v_list->lv_len > 0)
893 		    ga_append(&ga, NL);
894 	    }
895 	    ga_append(&ga, NUL);
896 	    retval = (char_u *)ga.ga_data;
897 	}
898 #ifdef FEAT_FLOAT
899 	else if (convert && tv.v_type == VAR_FLOAT)
900 	{
901 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
902 	    retval = vim_strsave(numbuf);
903 	}
904 #endif
905 	else
906 	    retval = vim_strsave(tv_get_string(&tv));
907 	clear_tv(&tv);
908     }
909 
910     return retval;
911 }
912 
913 /*
914  * Call eval_to_string() without using current local variables and using
915  * textlock.  When "use_sandbox" is TRUE use the sandbox.
916  */
917     char_u *
918 eval_to_string_safe(
919     char_u	*arg,
920     char_u	**nextcmd,
921     int		use_sandbox)
922 {
923     char_u	*retval;
924     funccal_entry_T funccal_entry;
925 
926     save_funccal(&funccal_entry);
927     if (use_sandbox)
928 	++sandbox;
929     ++textlock;
930     retval = eval_to_string(arg, nextcmd, FALSE);
931     if (use_sandbox)
932 	--sandbox;
933     --textlock;
934     restore_funccal();
935     return retval;
936 }
937 
938 /*
939  * Top level evaluation function, returning a number.
940  * Evaluates "expr" silently.
941  * Returns -1 for an error.
942  */
943     varnumber_T
944 eval_to_number(char_u *expr)
945 {
946     typval_T	rettv;
947     varnumber_T	retval;
948     char_u	*p = skipwhite(expr);
949 
950     ++emsg_off;
951 
952     if (eval1(&p, &rettv, TRUE) == FAIL)
953 	retval = -1;
954     else
955     {
956 	retval = tv_get_number_chk(&rettv, NULL);
957 	clear_tv(&rettv);
958     }
959     --emsg_off;
960 
961     return retval;
962 }
963 
964 /*
965  * Prepare v: variable "idx" to be used.
966  * Save the current typeval in "save_tv".
967  * When not used yet add the variable to the v: hashtable.
968  */
969     void
970 prepare_vimvar(int idx, typval_T *save_tv)
971 {
972     *save_tv = vimvars[idx].vv_tv;
973     if (vimvars[idx].vv_type == VAR_UNKNOWN)
974 	hash_add(&vimvarht, vimvars[idx].vv_di.di_key);
975 }
976 
977 /*
978  * Restore v: variable "idx" to typeval "save_tv".
979  * When no longer defined, remove the variable from the v: hashtable.
980  */
981     void
982 restore_vimvar(int idx, typval_T *save_tv)
983 {
984     hashitem_T	*hi;
985 
986     vimvars[idx].vv_tv = *save_tv;
987     if (vimvars[idx].vv_type == VAR_UNKNOWN)
988     {
989 	hi = hash_find(&vimvarht, vimvars[idx].vv_di.di_key);
990 	if (HASHITEM_EMPTY(hi))
991 	    internal_error("restore_vimvar()");
992 	else
993 	    hash_remove(&vimvarht, hi);
994     }
995 }
996 
997 #if defined(FEAT_SPELL) || defined(PROTO)
998 /*
999  * Evaluate an expression to a list with suggestions.
1000  * For the "expr:" part of 'spellsuggest'.
1001  * Returns NULL when there is an error.
1002  */
1003     list_T *
1004 eval_spell_expr(char_u *badword, char_u *expr)
1005 {
1006     typval_T	save_val;
1007     typval_T	rettv;
1008     list_T	*list = NULL;
1009     char_u	*p = skipwhite(expr);
1010 
1011     /* Set "v:val" to the bad word. */
1012     prepare_vimvar(VV_VAL, &save_val);
1013     vimvars[VV_VAL].vv_type = VAR_STRING;
1014     vimvars[VV_VAL].vv_str = badword;
1015     if (p_verbose == 0)
1016 	++emsg_off;
1017 
1018     if (eval1(&p, &rettv, TRUE) == OK)
1019     {
1020 	if (rettv.v_type != VAR_LIST)
1021 	    clear_tv(&rettv);
1022 	else
1023 	    list = rettv.vval.v_list;
1024     }
1025 
1026     if (p_verbose == 0)
1027 	--emsg_off;
1028     restore_vimvar(VV_VAL, &save_val);
1029 
1030     return list;
1031 }
1032 
1033 /*
1034  * "list" is supposed to contain two items: a word and a number.  Return the
1035  * word in "pp" and the number as the return value.
1036  * Return -1 if anything isn't right.
1037  * Used to get the good word and score from the eval_spell_expr() result.
1038  */
1039     int
1040 get_spellword(list_T *list, char_u **pp)
1041 {
1042     listitem_T	*li;
1043 
1044     li = list->lv_first;
1045     if (li == NULL)
1046 	return -1;
1047     *pp = tv_get_string(&li->li_tv);
1048 
1049     li = li->li_next;
1050     if (li == NULL)
1051 	return -1;
1052     return (int)tv_get_number(&li->li_tv);
1053 }
1054 #endif
1055 
1056 /*
1057  * Top level evaluation function.
1058  * Returns an allocated typval_T with the result.
1059  * Returns NULL when there is an error.
1060  */
1061     typval_T *
1062 eval_expr(char_u *arg, char_u **nextcmd)
1063 {
1064     typval_T	*tv;
1065 
1066     tv = (typval_T *)alloc(sizeof(typval_T));
1067     if (tv != NULL && eval0(arg, tv, nextcmd, TRUE) == FAIL)
1068 	VIM_CLEAR(tv);
1069 
1070     return tv;
1071 }
1072 
1073 
1074 /*
1075  * Call some Vim script function and return the result in "*rettv".
1076  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
1077  * should have type VAR_UNKNOWN.
1078  * Returns OK or FAIL.
1079  */
1080     int
1081 call_vim_function(
1082     char_u      *func,
1083     int		argc,
1084     typval_T	*argv,
1085     typval_T	*rettv)
1086 {
1087     int		doesrange;
1088     int		ret;
1089 
1090     rettv->v_type = VAR_UNKNOWN;		/* clear_tv() uses this */
1091     ret = call_func(func, -1, rettv, argc, argv, NULL,
1092 		    curwin->w_cursor.lnum, curwin->w_cursor.lnum,
1093 		    &doesrange, TRUE, NULL, NULL);
1094     if (ret == FAIL)
1095 	clear_tv(rettv);
1096 
1097     return ret;
1098 }
1099 
1100 /*
1101  * Call Vim script function "func" and return the result as a number.
1102  * Returns -1 when calling the function fails.
1103  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
1104  * have type VAR_UNKNOWN.
1105  */
1106     varnumber_T
1107 call_func_retnr(
1108     char_u      *func,
1109     int		argc,
1110     typval_T	*argv)
1111 {
1112     typval_T	rettv;
1113     varnumber_T	retval;
1114 
1115     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
1116 	return -1;
1117 
1118     retval = tv_get_number_chk(&rettv, NULL);
1119     clear_tv(&rettv);
1120     return retval;
1121 }
1122 
1123 #if defined(FEAT_CMDL_COMPL) \
1124 	|| defined(FEAT_COMPL_FUNC) || defined(PROTO)
1125 
1126 # if defined(FEAT_CMDL_COMPL) || defined(PROTO)
1127 /*
1128  * Call Vim script function "func" and return the result as a string.
1129  * Returns NULL when calling the function fails.
1130  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
1131  * have type VAR_UNKNOWN.
1132  */
1133     void *
1134 call_func_retstr(
1135     char_u      *func,
1136     int		argc,
1137     typval_T	*argv)
1138 {
1139     typval_T	rettv;
1140     char_u	*retval;
1141 
1142     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
1143 	return NULL;
1144 
1145     retval = vim_strsave(tv_get_string(&rettv));
1146     clear_tv(&rettv);
1147     return retval;
1148 }
1149 # endif
1150 
1151 /*
1152  * Call Vim script function "func" and return the result as a List.
1153  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
1154  * have type VAR_UNKNOWN.
1155  * Returns NULL when there is something wrong.
1156  */
1157     void *
1158 call_func_retlist(
1159     char_u      *func,
1160     int		argc,
1161     typval_T	*argv)
1162 {
1163     typval_T	rettv;
1164 
1165     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
1166 	return NULL;
1167 
1168     if (rettv.v_type != VAR_LIST)
1169     {
1170 	clear_tv(&rettv);
1171 	return NULL;
1172     }
1173 
1174     return rettv.vval.v_list;
1175 }
1176 #endif
1177 
1178 
1179 #ifdef FEAT_FOLDING
1180 /*
1181  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
1182  * it in "*cp".  Doesn't give error messages.
1183  */
1184     int
1185 eval_foldexpr(char_u *arg, int *cp)
1186 {
1187     typval_T	tv;
1188     varnumber_T	retval;
1189     char_u	*s;
1190     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
1191 								   OPT_LOCAL);
1192 
1193     ++emsg_off;
1194     if (use_sandbox)
1195 	++sandbox;
1196     ++textlock;
1197     *cp = NUL;
1198     if (eval0(arg, &tv, NULL, TRUE) == FAIL)
1199 	retval = 0;
1200     else
1201     {
1202 	/* If the result is a number, just return the number. */
1203 	if (tv.v_type == VAR_NUMBER)
1204 	    retval = tv.vval.v_number;
1205 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
1206 	    retval = 0;
1207 	else
1208 	{
1209 	    /* If the result is a string, check if there is a non-digit before
1210 	     * the number. */
1211 	    s = tv.vval.v_string;
1212 	    if (!VIM_ISDIGIT(*s) && *s != '-')
1213 		*cp = *s++;
1214 	    retval = atol((char *)s);
1215 	}
1216 	clear_tv(&tv);
1217     }
1218     --emsg_off;
1219     if (use_sandbox)
1220 	--sandbox;
1221     --textlock;
1222 
1223     return (int)retval;
1224 }
1225 #endif
1226 
1227 /*
1228  * ":let"			list all variable values
1229  * ":let var1 var2"		list variable values
1230  * ":let var = expr"		assignment command.
1231  * ":let var += expr"		assignment command.
1232  * ":let var -= expr"		assignment command.
1233  * ":let var *= expr"		assignment command.
1234  * ":let var /= expr"		assignment command.
1235  * ":let var %= expr"		assignment command.
1236  * ":let var .= expr"		assignment command.
1237  * ":let var ..= expr"		assignment command.
1238  * ":let [var1, var2] = expr"	unpack list.
1239  */
1240     void
1241 ex_let(exarg_T *eap)
1242 {
1243     char_u	*arg = eap->arg;
1244     char_u	*expr = NULL;
1245     typval_T	rettv;
1246     int		i;
1247     int		var_count = 0;
1248     int		semicolon = 0;
1249     char_u	op[2];
1250     char_u	*argend;
1251     int		first = TRUE;
1252     int		concat;
1253 
1254     argend = skip_var_list(arg, &var_count, &semicolon);
1255     if (argend == NULL)
1256 	return;
1257     if (argend > arg && argend[-1] == '.')  // for var.='str'
1258 	--argend;
1259     expr = skipwhite(argend);
1260     concat = expr[0] == '.'
1261 	&& ((expr[1] == '=' && current_sctx.sc_version < 2)
1262 		|| (expr[1] == '.' && expr[2] == '='));
1263     if (*expr != '=' && !((vim_strchr((char_u *)"+-*/%", *expr) != NULL
1264 						 && expr[1] == '=') || concat))
1265     {
1266 	/*
1267 	 * ":let" without "=": list variables
1268 	 */
1269 	if (*arg == '[')
1270 	    emsg(_(e_invarg));
1271 	else if (expr[0] == '.')
1272 	    emsg(_("E985: .= is not supported with script version 2"));
1273 	else if (!ends_excmd(*arg))
1274 	    /* ":let var1 var2" */
1275 	    arg = list_arg_vars(eap, arg, &first);
1276 	else if (!eap->skip)
1277 	{
1278 	    /* ":let" */
1279 	    list_glob_vars(&first);
1280 	    list_buf_vars(&first);
1281 	    list_win_vars(&first);
1282 	    list_tab_vars(&first);
1283 	    list_script_vars(&first);
1284 	    list_func_vars(&first);
1285 	    list_vim_vars(&first);
1286 	}
1287 	eap->nextcmd = check_nextcmd(arg);
1288     }
1289     else
1290     {
1291 	op[0] = '=';
1292 	op[1] = NUL;
1293 	if (*expr != '=')
1294 	{
1295 	    if (vim_strchr((char_u *)"+-*/%.", *expr) != NULL)
1296 	    {
1297 		op[0] = *expr;   // +=, -=, *=, /=, %= or .=
1298 		if (expr[0] == '.' && expr[1] == '.') // ..=
1299 		    ++expr;
1300 	    }
1301 	    expr = skipwhite(expr + 2);
1302 	}
1303 	else
1304 	    expr = skipwhite(expr + 1);
1305 
1306 	if (eap->skip)
1307 	    ++emsg_skip;
1308 	i = eval0(expr, &rettv, &eap->nextcmd, !eap->skip);
1309 	if (eap->skip)
1310 	{
1311 	    if (i != FAIL)
1312 		clear_tv(&rettv);
1313 	    --emsg_skip;
1314 	}
1315 	else if (i != FAIL)
1316 	{
1317 	    (void)ex_let_vars(eap->arg, &rettv, FALSE, semicolon, var_count,
1318 									  op);
1319 	    clear_tv(&rettv);
1320 	}
1321     }
1322 }
1323 
1324 /*
1325  * Assign the typevalue "tv" to the variable or variables at "arg_start".
1326  * Handles both "var" with any type and "[var, var; var]" with a list type.
1327  * When "nextchars" is not NULL it points to a string with characters that
1328  * must appear after the variable(s).  Use "+", "-" or "." for add, subtract
1329  * or concatenate.
1330  * Returns OK or FAIL;
1331  */
1332     static int
1333 ex_let_vars(
1334     char_u	*arg_start,
1335     typval_T	*tv,
1336     int		copy,		/* copy values from "tv", don't move */
1337     int		semicolon,	/* from skip_var_list() */
1338     int		var_count,	/* from skip_var_list() */
1339     char_u	*nextchars)
1340 {
1341     char_u	*arg = arg_start;
1342     list_T	*l;
1343     int		i;
1344     listitem_T	*item;
1345     typval_T	ltv;
1346 
1347     if (*arg != '[')
1348     {
1349 	/*
1350 	 * ":let var = expr" or ":for var in list"
1351 	 */
1352 	if (ex_let_one(arg, tv, copy, nextchars, nextchars) == NULL)
1353 	    return FAIL;
1354 	return OK;
1355     }
1356 
1357     /*
1358      * ":let [v1, v2] = list" or ":for [v1, v2] in listlist"
1359      */
1360     if (tv->v_type != VAR_LIST || (l = tv->vval.v_list) == NULL)
1361     {
1362 	emsg(_(e_listreq));
1363 	return FAIL;
1364     }
1365 
1366     i = list_len(l);
1367     if (semicolon == 0 && var_count < i)
1368     {
1369 	emsg(_("E687: Less targets than List items"));
1370 	return FAIL;
1371     }
1372     if (var_count - semicolon > i)
1373     {
1374 	emsg(_("E688: More targets than List items"));
1375 	return FAIL;
1376     }
1377 
1378     item = l->lv_first;
1379     while (*arg != ']')
1380     {
1381 	arg = skipwhite(arg + 1);
1382 	arg = ex_let_one(arg, &item->li_tv, TRUE, (char_u *)",;]", nextchars);
1383 	item = item->li_next;
1384 	if (arg == NULL)
1385 	    return FAIL;
1386 
1387 	arg = skipwhite(arg);
1388 	if (*arg == ';')
1389 	{
1390 	    /* Put the rest of the list (may be empty) in the var after ';'.
1391 	     * Create a new list for this. */
1392 	    l = list_alloc();
1393 	    if (l == NULL)
1394 		return FAIL;
1395 	    while (item != NULL)
1396 	    {
1397 		list_append_tv(l, &item->li_tv);
1398 		item = item->li_next;
1399 	    }
1400 
1401 	    ltv.v_type = VAR_LIST;
1402 	    ltv.v_lock = 0;
1403 	    ltv.vval.v_list = l;
1404 	    l->lv_refcount = 1;
1405 
1406 	    arg = ex_let_one(skipwhite(arg + 1), &ltv, FALSE,
1407 						    (char_u *)"]", nextchars);
1408 	    clear_tv(&ltv);
1409 	    if (arg == NULL)
1410 		return FAIL;
1411 	    break;
1412 	}
1413 	else if (*arg != ',' && *arg != ']')
1414 	{
1415 	    internal_error("ex_let_vars()");
1416 	    return FAIL;
1417 	}
1418     }
1419 
1420     return OK;
1421 }
1422 
1423 /*
1424  * Skip over assignable variable "var" or list of variables "[var, var]".
1425  * Used for ":let varvar = expr" and ":for varvar in expr".
1426  * For "[var, var]" increment "*var_count" for each variable.
1427  * for "[var, var; var]" set "semicolon".
1428  * Return NULL for an error.
1429  */
1430     static char_u *
1431 skip_var_list(
1432     char_u	*arg,
1433     int		*var_count,
1434     int		*semicolon)
1435 {
1436     char_u	*p, *s;
1437 
1438     if (*arg == '[')
1439     {
1440 	/* "[var, var]": find the matching ']'. */
1441 	p = arg;
1442 	for (;;)
1443 	{
1444 	    p = skipwhite(p + 1);	/* skip whites after '[', ';' or ',' */
1445 	    s = skip_var_one(p);
1446 	    if (s == p)
1447 	    {
1448 		semsg(_(e_invarg2), p);
1449 		return NULL;
1450 	    }
1451 	    ++*var_count;
1452 
1453 	    p = skipwhite(s);
1454 	    if (*p == ']')
1455 		break;
1456 	    else if (*p == ';')
1457 	    {
1458 		if (*semicolon == 1)
1459 		{
1460 		    emsg(_("Double ; in list of variables"));
1461 		    return NULL;
1462 		}
1463 		*semicolon = 1;
1464 	    }
1465 	    else if (*p != ',')
1466 	    {
1467 		semsg(_(e_invarg2), p);
1468 		return NULL;
1469 	    }
1470 	}
1471 	return p + 1;
1472     }
1473     else
1474 	return skip_var_one(arg);
1475 }
1476 
1477 /*
1478  * Skip one (assignable) variable name, including @r, $VAR, &option, d.key,
1479  * l[idx].
1480  */
1481     static char_u *
1482 skip_var_one(char_u *arg)
1483 {
1484     if (*arg == '@' && arg[1] != NUL)
1485 	return arg + 2;
1486     return find_name_end(*arg == '$' || *arg == '&' ? arg + 1 : arg,
1487 				   NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1488 }
1489 
1490 /*
1491  * List variables for hashtab "ht" with prefix "prefix".
1492  * If "empty" is TRUE also list NULL strings as empty strings.
1493  */
1494     void
1495 list_hashtable_vars(
1496     hashtab_T	*ht,
1497     char	*prefix,
1498     int		empty,
1499     int		*first)
1500 {
1501     hashitem_T	*hi;
1502     dictitem_T	*di;
1503     int		todo;
1504     char_u	buf[IOSIZE];
1505 
1506     todo = (int)ht->ht_used;
1507     for (hi = ht->ht_array; todo > 0 && !got_int; ++hi)
1508     {
1509 	if (!HASHITEM_EMPTY(hi))
1510 	{
1511 	    --todo;
1512 	    di = HI2DI(hi);
1513 
1514 	    // apply :filter /pat/ to variable name
1515 	    vim_strncpy((char_u *)buf, (char_u *)prefix, IOSIZE - 1);
1516 	    vim_strcat((char_u *)buf, di->di_key, IOSIZE);
1517 	    if (message_filtered(buf))
1518 		continue;
1519 
1520 	    if (empty || di->di_tv.v_type != VAR_STRING
1521 					   || di->di_tv.vval.v_string != NULL)
1522 		list_one_var(di, prefix, first);
1523 	}
1524     }
1525 }
1526 
1527 /*
1528  * List global variables.
1529  */
1530     static void
1531 list_glob_vars(int *first)
1532 {
1533     list_hashtable_vars(&globvarht, "", TRUE, first);
1534 }
1535 
1536 /*
1537  * List buffer variables.
1538  */
1539     static void
1540 list_buf_vars(int *first)
1541 {
1542     list_hashtable_vars(&curbuf->b_vars->dv_hashtab, "b:", TRUE, first);
1543 }
1544 
1545 /*
1546  * List window variables.
1547  */
1548     static void
1549 list_win_vars(int *first)
1550 {
1551     list_hashtable_vars(&curwin->w_vars->dv_hashtab, "w:", TRUE, first);
1552 }
1553 
1554 /*
1555  * List tab page variables.
1556  */
1557     static void
1558 list_tab_vars(int *first)
1559 {
1560     list_hashtable_vars(&curtab->tp_vars->dv_hashtab, "t:", TRUE, first);
1561 }
1562 
1563 /*
1564  * List Vim variables.
1565  */
1566     static void
1567 list_vim_vars(int *first)
1568 {
1569     list_hashtable_vars(&vimvarht, "v:", FALSE, first);
1570 }
1571 
1572 /*
1573  * List script-local variables, if there is a script.
1574  */
1575     static void
1576 list_script_vars(int *first)
1577 {
1578     if (current_sctx.sc_sid > 0 && current_sctx.sc_sid <= ga_scripts.ga_len)
1579 	list_hashtable_vars(&SCRIPT_VARS(current_sctx.sc_sid),
1580 							   "s:", FALSE, first);
1581 }
1582 
1583 /*
1584  * List variables in "arg".
1585  */
1586     static char_u *
1587 list_arg_vars(exarg_T *eap, char_u *arg, int *first)
1588 {
1589     int		error = FALSE;
1590     int		len;
1591     char_u	*name;
1592     char_u	*name_start;
1593     char_u	*arg_subsc;
1594     char_u	*tofree;
1595     typval_T    tv;
1596 
1597     while (!ends_excmd(*arg) && !got_int)
1598     {
1599 	if (error || eap->skip)
1600 	{
1601 	    arg = find_name_end(arg, NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1602 	    if (!VIM_ISWHITE(*arg) && !ends_excmd(*arg))
1603 	    {
1604 		emsg_severe = TRUE;
1605 		emsg(_(e_trailing));
1606 		break;
1607 	    }
1608 	}
1609 	else
1610 	{
1611 	    /* get_name_len() takes care of expanding curly braces */
1612 	    name_start = name = arg;
1613 	    len = get_name_len(&arg, &tofree, TRUE, TRUE);
1614 	    if (len <= 0)
1615 	    {
1616 		/* This is mainly to keep test 49 working: when expanding
1617 		 * curly braces fails overrule the exception error message. */
1618 		if (len < 0 && !aborting())
1619 		{
1620 		    emsg_severe = TRUE;
1621 		    semsg(_(e_invarg2), arg);
1622 		    break;
1623 		}
1624 		error = TRUE;
1625 	    }
1626 	    else
1627 	    {
1628 		if (tofree != NULL)
1629 		    name = tofree;
1630 		if (get_var_tv(name, len, &tv, NULL, TRUE, FALSE) == FAIL)
1631 		    error = TRUE;
1632 		else
1633 		{
1634 		    /* handle d.key, l[idx], f(expr) */
1635 		    arg_subsc = arg;
1636 		    if (handle_subscript(&arg, &tv, TRUE, TRUE) == FAIL)
1637 			error = TRUE;
1638 		    else
1639 		    {
1640 			if (arg == arg_subsc && len == 2 && name[1] == ':')
1641 			{
1642 			    switch (*name)
1643 			    {
1644 				case 'g': list_glob_vars(first); break;
1645 				case 'b': list_buf_vars(first); break;
1646 				case 'w': list_win_vars(first); break;
1647 				case 't': list_tab_vars(first); break;
1648 				case 'v': list_vim_vars(first); break;
1649 				case 's': list_script_vars(first); break;
1650 				case 'l': list_func_vars(first); break;
1651 				default:
1652 					  semsg(_("E738: Can't list variables for %s"), name);
1653 			    }
1654 			}
1655 			else
1656 			{
1657 			    char_u	numbuf[NUMBUFLEN];
1658 			    char_u	*tf;
1659 			    int		c;
1660 			    char_u	*s;
1661 
1662 			    s = echo_string(&tv, &tf, numbuf, 0);
1663 			    c = *arg;
1664 			    *arg = NUL;
1665 			    list_one_var_a("",
1666 				    arg == arg_subsc ? name : name_start,
1667 				    tv.v_type,
1668 				    s == NULL ? (char_u *)"" : s,
1669 				    first);
1670 			    *arg = c;
1671 			    vim_free(tf);
1672 			}
1673 			clear_tv(&tv);
1674 		    }
1675 		}
1676 	    }
1677 
1678 	    vim_free(tofree);
1679 	}
1680 
1681 	arg = skipwhite(arg);
1682     }
1683 
1684     return arg;
1685 }
1686 
1687 /*
1688  * Set one item of ":let var = expr" or ":let [v1, v2] = list" to its value.
1689  * Returns a pointer to the char just after the var name.
1690  * Returns NULL if there is an error.
1691  */
1692     static char_u *
1693 ex_let_one(
1694     char_u	*arg,		/* points to variable name */
1695     typval_T	*tv,		/* value to assign to variable */
1696     int		copy,		/* copy value from "tv" */
1697     char_u	*endchars,	/* valid chars after variable name  or NULL */
1698     char_u	*op)		/* "+", "-", "."  or NULL*/
1699 {
1700     int		c1;
1701     char_u	*name;
1702     char_u	*p;
1703     char_u	*arg_end = NULL;
1704     int		len;
1705     int		opt_flags;
1706     char_u	*tofree = NULL;
1707 
1708     /*
1709      * ":let $VAR = expr": Set environment variable.
1710      */
1711     if (*arg == '$')
1712     {
1713 	/* Find the end of the name. */
1714 	++arg;
1715 	name = arg;
1716 	len = get_env_len(&arg);
1717 	if (len == 0)
1718 	    semsg(_(e_invarg2), name - 1);
1719 	else
1720 	{
1721 	    if (op != NULL && vim_strchr((char_u *)"+-*/%", *op) != NULL)
1722 		semsg(_(e_letwrong), op);
1723 	    else if (endchars != NULL
1724 			     && vim_strchr(endchars, *skipwhite(arg)) == NULL)
1725 		emsg(_(e_letunexp));
1726 	    else if (!check_secure())
1727 	    {
1728 		c1 = name[len];
1729 		name[len] = NUL;
1730 		p = tv_get_string_chk(tv);
1731 		if (p != NULL && op != NULL && *op == '.')
1732 		{
1733 		    int	    mustfree = FALSE;
1734 		    char_u  *s = vim_getenv(name, &mustfree);
1735 
1736 		    if (s != NULL)
1737 		    {
1738 			p = tofree = concat_str(s, p);
1739 			if (mustfree)
1740 			    vim_free(s);
1741 		    }
1742 		}
1743 		if (p != NULL)
1744 		{
1745 		    vim_setenv(name, p);
1746 		    if (STRICMP(name, "HOME") == 0)
1747 			init_homedir();
1748 		    else if (didset_vim && STRICMP(name, "VIM") == 0)
1749 			didset_vim = FALSE;
1750 		    else if (didset_vimruntime
1751 					&& STRICMP(name, "VIMRUNTIME") == 0)
1752 			didset_vimruntime = FALSE;
1753 		    arg_end = arg;
1754 		}
1755 		name[len] = c1;
1756 		vim_free(tofree);
1757 	    }
1758 	}
1759     }
1760 
1761     /*
1762      * ":let &option = expr": Set option value.
1763      * ":let &l:option = expr": Set local option value.
1764      * ":let &g:option = expr": Set global option value.
1765      */
1766     else if (*arg == '&')
1767     {
1768 	/* Find the end of the name. */
1769 	p = find_option_end(&arg, &opt_flags);
1770 	if (p == NULL || (endchars != NULL
1771 			      && vim_strchr(endchars, *skipwhite(p)) == NULL))
1772 	    emsg(_(e_letunexp));
1773 	else
1774 	{
1775 	    long	n;
1776 	    int		opt_type;
1777 	    long	numval;
1778 	    char_u	*stringval = NULL;
1779 	    char_u	*s;
1780 
1781 	    c1 = *p;
1782 	    *p = NUL;
1783 
1784 	    n = (long)tv_get_number(tv);
1785 	    s = tv_get_string_chk(tv);	    /* != NULL if number or string */
1786 	    if (s != NULL && op != NULL && *op != '=')
1787 	    {
1788 		opt_type = get_option_value(arg, &numval,
1789 						       &stringval, opt_flags);
1790 		if ((opt_type == 1 && *op == '.')
1791 			|| (opt_type == 0 && *op != '.'))
1792 		{
1793 		    semsg(_(e_letwrong), op);
1794 		    s = NULL;  // don't set the value
1795 		}
1796 		else
1797 		{
1798 		    if (opt_type == 1)  // number
1799 		    {
1800 			switch (*op)
1801 			{
1802 			    case '+': n = numval + n; break;
1803 			    case '-': n = numval - n; break;
1804 			    case '*': n = numval * n; break;
1805 			    case '/': n = (long)num_divide(numval, n); break;
1806 			    case '%': n = (long)num_modulus(numval, n); break;
1807 			}
1808 		    }
1809 		    else if (opt_type == 0 && stringval != NULL) // string
1810 		    {
1811 			s = concat_str(stringval, s);
1812 			vim_free(stringval);
1813 			stringval = s;
1814 		    }
1815 		}
1816 	    }
1817 	    if (s != NULL)
1818 	    {
1819 		set_option_value(arg, n, s, opt_flags);
1820 		arg_end = p;
1821 	    }
1822 	    *p = c1;
1823 	    vim_free(stringval);
1824 	}
1825     }
1826 
1827     /*
1828      * ":let @r = expr": Set register contents.
1829      */
1830     else if (*arg == '@')
1831     {
1832 	++arg;
1833 	if (op != NULL && vim_strchr((char_u *)"+-*/%", *op) != NULL)
1834 	    semsg(_(e_letwrong), op);
1835 	else if (endchars != NULL
1836 			 && vim_strchr(endchars, *skipwhite(arg + 1)) == NULL)
1837 	    emsg(_(e_letunexp));
1838 	else
1839 	{
1840 	    char_u	*ptofree = NULL;
1841 	    char_u	*s;
1842 
1843 	    p = tv_get_string_chk(tv);
1844 	    if (p != NULL && op != NULL && *op == '.')
1845 	    {
1846 		s = get_reg_contents(*arg == '@' ? '"' : *arg, GREG_EXPR_SRC);
1847 		if (s != NULL)
1848 		{
1849 		    p = ptofree = concat_str(s, p);
1850 		    vim_free(s);
1851 		}
1852 	    }
1853 	    if (p != NULL)
1854 	    {
1855 		write_reg_contents(*arg == '@' ? '"' : *arg, p, -1, FALSE);
1856 		arg_end = arg + 1;
1857 	    }
1858 	    vim_free(ptofree);
1859 	}
1860     }
1861 
1862     /*
1863      * ":let var = expr": Set internal variable.
1864      * ":let {expr} = expr": Idem, name made with curly braces
1865      */
1866     else if (eval_isnamec1(*arg) || *arg == '{')
1867     {
1868 	lval_T	lv;
1869 
1870 	p = get_lval(arg, tv, &lv, FALSE, FALSE, 0, FNE_CHECK_START);
1871 	if (p != NULL && lv.ll_name != NULL)
1872 	{
1873 	    if (endchars != NULL && vim_strchr(endchars, *skipwhite(p)) == NULL)
1874 		emsg(_(e_letunexp));
1875 	    else
1876 	    {
1877 		set_var_lval(&lv, p, tv, copy, op);
1878 		arg_end = p;
1879 	    }
1880 	}
1881 	clear_lval(&lv);
1882     }
1883 
1884     else
1885 	semsg(_(e_invarg2), arg);
1886 
1887     return arg_end;
1888 }
1889 
1890 /*
1891  * Get an lval: variable, Dict item or List item that can be assigned a value
1892  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
1893  * "name.key", "name.key[expr]" etc.
1894  * Indexing only works if "name" is an existing List or Dictionary.
1895  * "name" points to the start of the name.
1896  * If "rettv" is not NULL it points to the value to be assigned.
1897  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
1898  * wrong; must end in space or cmd separator.
1899  *
1900  * flags:
1901  *  GLV_QUIET:       do not give error messages
1902  *  GLV_READ_ONLY:   will not change the variable
1903  *  GLV_NO_AUTOLOAD: do not use script autoloading
1904  *
1905  * Returns a pointer to just after the name, including indexes.
1906  * When an evaluation error occurs "lp->ll_name" is NULL;
1907  * Returns NULL for a parsing error.  Still need to free items in "lp"!
1908  */
1909     char_u *
1910 get_lval(
1911     char_u	*name,
1912     typval_T	*rettv,
1913     lval_T	*lp,
1914     int		unlet,
1915     int		skip,
1916     int		flags,	    /* GLV_ values */
1917     int		fne_flags)  /* flags for find_name_end() */
1918 {
1919     char_u	*p;
1920     char_u	*expr_start, *expr_end;
1921     int		cc;
1922     dictitem_T	*v;
1923     typval_T	var1;
1924     typval_T	var2;
1925     int		empty1 = FALSE;
1926     listitem_T	*ni;
1927     char_u	*key = NULL;
1928     int		len;
1929     hashtab_T	*ht;
1930     int		quiet = flags & GLV_QUIET;
1931 
1932     /* Clear everything in "lp". */
1933     vim_memset(lp, 0, sizeof(lval_T));
1934 
1935     if (skip)
1936     {
1937 	/* When skipping just find the end of the name. */
1938 	lp->ll_name = name;
1939 	return find_name_end(name, NULL, NULL, FNE_INCL_BR | fne_flags);
1940     }
1941 
1942     /* Find the end of the name. */
1943     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
1944     if (expr_start != NULL)
1945     {
1946 	/* Don't expand the name when we already know there is an error. */
1947 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
1948 						    && *p != '[' && *p != '.')
1949 	{
1950 	    emsg(_(e_trailing));
1951 	    return NULL;
1952 	}
1953 
1954 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
1955 	if (lp->ll_exp_name == NULL)
1956 	{
1957 	    /* Report an invalid expression in braces, unless the
1958 	     * expression evaluation has been cancelled due to an
1959 	     * aborting error, an interrupt, or an exception. */
1960 	    if (!aborting() && !quiet)
1961 	    {
1962 		emsg_severe = TRUE;
1963 		semsg(_(e_invarg2), name);
1964 		return NULL;
1965 	    }
1966 	}
1967 	lp->ll_name = lp->ll_exp_name;
1968     }
1969     else
1970 	lp->ll_name = name;
1971 
1972     /* Without [idx] or .key we are done. */
1973     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
1974 	return p;
1975 
1976     cc = *p;
1977     *p = NUL;
1978     /* Only pass &ht when we would write to the variable, it prevents autoload
1979      * as well. */
1980     v = find_var(lp->ll_name, (flags & GLV_READ_ONLY) ? NULL : &ht,
1981 						      flags & GLV_NO_AUTOLOAD);
1982     if (v == NULL && !quiet)
1983 	semsg(_(e_undefvar), lp->ll_name);
1984     *p = cc;
1985     if (v == NULL)
1986 	return NULL;
1987 
1988     /*
1989      * Loop until no more [idx] or .key is following.
1990      */
1991     lp->ll_tv = &v->di_tv;
1992     var1.v_type = VAR_UNKNOWN;
1993     var2.v_type = VAR_UNKNOWN;
1994     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
1995     {
1996 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
1997 		&& !(lp->ll_tv->v_type == VAR_DICT
1998 					   && lp->ll_tv->vval.v_dict != NULL)
1999 		&& !(lp->ll_tv->v_type == VAR_BLOB
2000 					   && lp->ll_tv->vval.v_blob != NULL))
2001 	{
2002 	    if (!quiet)
2003 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
2004 	    return NULL;
2005 	}
2006 	if (lp->ll_range)
2007 	{
2008 	    if (!quiet)
2009 		emsg(_("E708: [:] must come last"));
2010 	    return NULL;
2011 	}
2012 
2013 	len = -1;
2014 	if (*p == '.')
2015 	{
2016 	    key = p + 1;
2017 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
2018 		;
2019 	    if (len == 0)
2020 	    {
2021 		if (!quiet)
2022 		    emsg(_(e_emptykey));
2023 		return NULL;
2024 	    }
2025 	    p = key + len;
2026 	}
2027 	else
2028 	{
2029 	    /* Get the index [expr] or the first index [expr: ]. */
2030 	    p = skipwhite(p + 1);
2031 	    if (*p == ':')
2032 		empty1 = TRUE;
2033 	    else
2034 	    {
2035 		empty1 = FALSE;
2036 		if (eval1(&p, &var1, TRUE) == FAIL)	/* recursive! */
2037 		    return NULL;
2038 		if (tv_get_string_chk(&var1) == NULL)
2039 		{
2040 		    /* not a number or string */
2041 		    clear_tv(&var1);
2042 		    return NULL;
2043 		}
2044 	    }
2045 
2046 	    /* Optionally get the second index [ :expr]. */
2047 	    if (*p == ':')
2048 	    {
2049 		if (lp->ll_tv->v_type == VAR_DICT)
2050 		{
2051 		    if (!quiet)
2052 			emsg(_(e_dictrange));
2053 		    clear_tv(&var1);
2054 		    return NULL;
2055 		}
2056 		if (rettv != NULL
2057 			&& !(rettv->v_type == VAR_LIST
2058 						 && rettv->vval.v_list != NULL)
2059 			&& !(rettv->v_type == VAR_BLOB
2060 						&& rettv->vval.v_blob != NULL))
2061 		{
2062 		    if (!quiet)
2063 			emsg(_("E709: [:] requires a List or Blob value"));
2064 		    clear_tv(&var1);
2065 		    return NULL;
2066 		}
2067 		p = skipwhite(p + 1);
2068 		if (*p == ']')
2069 		    lp->ll_empty2 = TRUE;
2070 		else
2071 		{
2072 		    lp->ll_empty2 = FALSE;
2073 		    if (eval1(&p, &var2, TRUE) == FAIL)	/* recursive! */
2074 		    {
2075 			clear_tv(&var1);
2076 			return NULL;
2077 		    }
2078 		    if (tv_get_string_chk(&var2) == NULL)
2079 		    {
2080 			/* not a number or string */
2081 			clear_tv(&var1);
2082 			clear_tv(&var2);
2083 			return NULL;
2084 		    }
2085 		}
2086 		lp->ll_range = TRUE;
2087 	    }
2088 	    else
2089 		lp->ll_range = FALSE;
2090 
2091 	    if (*p != ']')
2092 	    {
2093 		if (!quiet)
2094 		    emsg(_(e_missbrac));
2095 		clear_tv(&var1);
2096 		clear_tv(&var2);
2097 		return NULL;
2098 	    }
2099 
2100 	    /* Skip to past ']'. */
2101 	    ++p;
2102 	}
2103 
2104 	if (lp->ll_tv->v_type == VAR_DICT)
2105 	{
2106 	    if (len == -1)
2107 	    {
2108 		/* "[key]": get key from "var1" */
2109 		key = tv_get_string_chk(&var1);	/* is number or string */
2110 		if (key == NULL)
2111 		{
2112 		    clear_tv(&var1);
2113 		    return NULL;
2114 		}
2115 	    }
2116 	    lp->ll_list = NULL;
2117 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
2118 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
2119 
2120 	    /* When assigning to a scope dictionary check that a function and
2121 	     * variable name is valid (only variable name unless it is l: or
2122 	     * g: dictionary). Disallow overwriting a builtin function. */
2123 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
2124 	    {
2125 		int prevval;
2126 		int wrong;
2127 
2128 		if (len != -1)
2129 		{
2130 		    prevval = key[len];
2131 		    key[len] = NUL;
2132 		}
2133 		else
2134 		    prevval = 0; /* avoid compiler warning */
2135 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
2136 			       && rettv->v_type == VAR_FUNC
2137 			       && var_check_func_name(key, lp->ll_di == NULL))
2138 			|| !valid_varname(key);
2139 		if (len != -1)
2140 		    key[len] = prevval;
2141 		if (wrong)
2142 		    return NULL;
2143 	    }
2144 
2145 	    if (lp->ll_di == NULL)
2146 	    {
2147 		// Can't add "v:" or "a:" variable.
2148 		if (lp->ll_dict == &vimvardict
2149 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
2150 		{
2151 		    semsg(_(e_illvar), name);
2152 		    clear_tv(&var1);
2153 		    return NULL;
2154 		}
2155 
2156 		// Key does not exist in dict: may need to add it.
2157 		if (*p == '[' || *p == '.' || unlet)
2158 		{
2159 		    if (!quiet)
2160 			semsg(_(e_dictkey), key);
2161 		    clear_tv(&var1);
2162 		    return NULL;
2163 		}
2164 		if (len == -1)
2165 		    lp->ll_newkey = vim_strsave(key);
2166 		else
2167 		    lp->ll_newkey = vim_strnsave(key, len);
2168 		clear_tv(&var1);
2169 		if (lp->ll_newkey == NULL)
2170 		    p = NULL;
2171 		break;
2172 	    }
2173 	    /* existing variable, need to check if it can be changed */
2174 	    else if ((flags & GLV_READ_ONLY) == 0
2175 			     && var_check_ro(lp->ll_di->di_flags, name, FALSE))
2176 	    {
2177 		clear_tv(&var1);
2178 		return NULL;
2179 	    }
2180 
2181 	    clear_tv(&var1);
2182 	    lp->ll_tv = &lp->ll_di->di_tv;
2183 	}
2184 	else if (lp->ll_tv->v_type == VAR_BLOB)
2185 	{
2186 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
2187 
2188 	    /*
2189 	     * Get the number and item for the only or first index of the List.
2190 	     */
2191 	    if (empty1)
2192 		lp->ll_n1 = 0;
2193 	    else
2194 		// is number or string
2195 		lp->ll_n1 = (long)tv_get_number(&var1);
2196 	    clear_tv(&var1);
2197 
2198 	    if (lp->ll_n1 < 0
2199 		    || lp->ll_n1 > bloblen
2200 		    || (lp->ll_range && lp->ll_n1 == bloblen))
2201 	    {
2202 		if (!quiet)
2203 		    semsg(_(e_blobidx), lp->ll_n1);
2204 		clear_tv(&var2);
2205 		return NULL;
2206 	    }
2207 	    if (lp->ll_range && !lp->ll_empty2)
2208 	    {
2209 		lp->ll_n2 = (long)tv_get_number(&var2);
2210 		clear_tv(&var2);
2211 		if (lp->ll_n2 < 0
2212 			|| lp->ll_n2 >= bloblen
2213 			|| lp->ll_n2 < lp->ll_n1)
2214 		{
2215 		    if (!quiet)
2216 			semsg(_(e_blobidx), lp->ll_n2);
2217 		    return NULL;
2218 		}
2219 	    }
2220 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
2221 	    lp->ll_tv = NULL;
2222 	    break;
2223 	}
2224 	else
2225 	{
2226 	    /*
2227 	     * Get the number and item for the only or first index of the List.
2228 	     */
2229 	    if (empty1)
2230 		lp->ll_n1 = 0;
2231 	    else
2232 		/* is number or string */
2233 		lp->ll_n1 = (long)tv_get_number(&var1);
2234 	    clear_tv(&var1);
2235 
2236 	    lp->ll_dict = NULL;
2237 	    lp->ll_list = lp->ll_tv->vval.v_list;
2238 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2239 	    if (lp->ll_li == NULL)
2240 	    {
2241 		if (lp->ll_n1 < 0)
2242 		{
2243 		    lp->ll_n1 = 0;
2244 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2245 		}
2246 	    }
2247 	    if (lp->ll_li == NULL)
2248 	    {
2249 		clear_tv(&var2);
2250 		if (!quiet)
2251 		    semsg(_(e_listidx), lp->ll_n1);
2252 		return NULL;
2253 	    }
2254 
2255 	    /*
2256 	     * May need to find the item or absolute index for the second
2257 	     * index of a range.
2258 	     * When no index given: "lp->ll_empty2" is TRUE.
2259 	     * Otherwise "lp->ll_n2" is set to the second index.
2260 	     */
2261 	    if (lp->ll_range && !lp->ll_empty2)
2262 	    {
2263 		lp->ll_n2 = (long)tv_get_number(&var2);
2264 						    /* is number or string */
2265 		clear_tv(&var2);
2266 		if (lp->ll_n2 < 0)
2267 		{
2268 		    ni = list_find(lp->ll_list, lp->ll_n2);
2269 		    if (ni == NULL)
2270 		    {
2271 			if (!quiet)
2272 			    semsg(_(e_listidx), lp->ll_n2);
2273 			return NULL;
2274 		    }
2275 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
2276 		}
2277 
2278 		/* Check that lp->ll_n2 isn't before lp->ll_n1. */
2279 		if (lp->ll_n1 < 0)
2280 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
2281 		if (lp->ll_n2 < lp->ll_n1)
2282 		{
2283 		    if (!quiet)
2284 			semsg(_(e_listidx), lp->ll_n2);
2285 		    return NULL;
2286 		}
2287 	    }
2288 
2289 	    lp->ll_tv = &lp->ll_li->li_tv;
2290 	}
2291     }
2292 
2293     clear_tv(&var1);
2294     return p;
2295 }
2296 
2297 /*
2298  * Clear lval "lp" that was filled by get_lval().
2299  */
2300     void
2301 clear_lval(lval_T *lp)
2302 {
2303     vim_free(lp->ll_exp_name);
2304     vim_free(lp->ll_newkey);
2305 }
2306 
2307 /*
2308  * Set a variable that was parsed by get_lval() to "rettv".
2309  * "endp" points to just after the parsed name.
2310  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
2311  * "%" for "%=", "." for ".=" or "=" for "=".
2312  */
2313     static void
2314 set_var_lval(
2315     lval_T	*lp,
2316     char_u	*endp,
2317     typval_T	*rettv,
2318     int		copy,
2319     char_u	*op)
2320 {
2321     int		cc;
2322     listitem_T	*ri;
2323     dictitem_T	*di;
2324 
2325     if (lp->ll_tv == NULL)
2326     {
2327 	cc = *endp;
2328 	*endp = NUL;
2329 	if (lp->ll_blob != NULL)
2330 	{
2331 	    int	    error = FALSE, val;
2332 
2333 	    if (op != NULL && *op != '=')
2334 	    {
2335 		semsg(_(e_letwrong), op);
2336 		return;
2337 	    }
2338 
2339 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
2340 	    {
2341 		int	il, ir;
2342 
2343 		if (lp->ll_empty2)
2344 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
2345 
2346 		if (lp->ll_n2 - lp->ll_n1 + 1 != blob_len(rettv->vval.v_blob))
2347 		{
2348 		    emsg(_("E972: Blob value does not have the right number of bytes"));
2349 		    return;
2350 		}
2351 		if (lp->ll_empty2)
2352 		    lp->ll_n2 = blob_len(lp->ll_blob);
2353 
2354 		ir = 0;
2355 		for (il = lp->ll_n1; il <= lp->ll_n2; il++)
2356 		    blob_set(lp->ll_blob, il,
2357 			    blob_get(rettv->vval.v_blob, ir++));
2358 	    }
2359 	    else
2360 	    {
2361 		val = (int)tv_get_number_chk(rettv, &error);
2362 		if (!error)
2363 		{
2364 		    garray_T *gap = &lp->ll_blob->bv_ga;
2365 
2366 		    // Allow for appending a byte.  Setting a byte beyond
2367 		    // the end is an error otherwise.
2368 		    if (lp->ll_n1 < gap->ga_len
2369 			    || (lp->ll_n1 == gap->ga_len
2370 				&& ga_grow(&lp->ll_blob->bv_ga, 1) == OK))
2371 		    {
2372 			blob_set(lp->ll_blob, lp->ll_n1, val);
2373 			if (lp->ll_n1 == gap->ga_len)
2374 			    ++gap->ga_len;
2375 		    }
2376 		    // error for invalid range was already given in get_lval()
2377 		}
2378 	    }
2379 	}
2380 	else if (op != NULL && *op != '=')
2381 	{
2382 	    typval_T tv;
2383 
2384 	    // handle +=, -=, *=, /=, %= and .=
2385 	    di = NULL;
2386 	    if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
2387 					     &tv, &di, TRUE, FALSE) == OK)
2388 	    {
2389 		if ((di == NULL
2390 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
2391 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
2392 			&& tv_op(&tv, rettv, op) == OK)
2393 		    set_var(lp->ll_name, &tv, FALSE);
2394 		clear_tv(&tv);
2395 	    }
2396 	}
2397 	else
2398 	    set_var(lp->ll_name, rettv, copy);
2399 	*endp = cc;
2400     }
2401     else if (var_check_lock(lp->ll_newkey == NULL
2402 		? lp->ll_tv->v_lock
2403 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
2404 	;
2405     else if (lp->ll_range)
2406     {
2407 	listitem_T *ll_li = lp->ll_li;
2408 	int	    ll_n1 = lp->ll_n1;
2409 
2410 	/*
2411 	 * Check whether any of the list items is locked
2412 	 */
2413 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
2414 	{
2415 	    if (var_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
2416 		return;
2417 	    ri = ri->li_next;
2418 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
2419 		break;
2420 	    ll_li = ll_li->li_next;
2421 	    ++ll_n1;
2422 	}
2423 
2424 	/*
2425 	 * Assign the List values to the list items.
2426 	 */
2427 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
2428 	{
2429 	    if (op != NULL && *op != '=')
2430 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
2431 	    else
2432 	    {
2433 		clear_tv(&lp->ll_li->li_tv);
2434 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
2435 	    }
2436 	    ri = ri->li_next;
2437 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
2438 		break;
2439 	    if (lp->ll_li->li_next == NULL)
2440 	    {
2441 		/* Need to add an empty item. */
2442 		if (list_append_number(lp->ll_list, 0) == FAIL)
2443 		{
2444 		    ri = NULL;
2445 		    break;
2446 		}
2447 	    }
2448 	    lp->ll_li = lp->ll_li->li_next;
2449 	    ++lp->ll_n1;
2450 	}
2451 	if (ri != NULL)
2452 	    emsg(_("E710: List value has more items than target"));
2453 	else if (lp->ll_empty2
2454 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
2455 		: lp->ll_n1 != lp->ll_n2)
2456 	    emsg(_("E711: List value has not enough items"));
2457     }
2458     else
2459     {
2460 	/*
2461 	 * Assign to a List or Dictionary item.
2462 	 */
2463 	if (lp->ll_newkey != NULL)
2464 	{
2465 	    if (op != NULL && *op != '=')
2466 	    {
2467 		semsg(_(e_letwrong), op);
2468 		return;
2469 	    }
2470 
2471 	    /* Need to add an item to the Dictionary. */
2472 	    di = dictitem_alloc(lp->ll_newkey);
2473 	    if (di == NULL)
2474 		return;
2475 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
2476 	    {
2477 		vim_free(di);
2478 		return;
2479 	    }
2480 	    lp->ll_tv = &di->di_tv;
2481 	}
2482 	else if (op != NULL && *op != '=')
2483 	{
2484 	    tv_op(lp->ll_tv, rettv, op);
2485 	    return;
2486 	}
2487 	else
2488 	    clear_tv(lp->ll_tv);
2489 
2490 	/*
2491 	 * Assign the value to the variable or list item.
2492 	 */
2493 	if (copy)
2494 	    copy_tv(rettv, lp->ll_tv);
2495 	else
2496 	{
2497 	    *lp->ll_tv = *rettv;
2498 	    lp->ll_tv->v_lock = 0;
2499 	    init_tv(rettv);
2500 	}
2501     }
2502 }
2503 
2504 /*
2505  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
2506  * and "tv1 .= tv2"
2507  * Returns OK or FAIL.
2508  */
2509     static int
2510 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
2511 {
2512     varnumber_T	n;
2513     char_u	numbuf[NUMBUFLEN];
2514     char_u	*s;
2515 
2516     /* Can't do anything with a Funcref, Dict, v:true on the right. */
2517     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
2518 						&& tv2->v_type != VAR_SPECIAL)
2519     {
2520 	switch (tv1->v_type)
2521 	{
2522 	    case VAR_UNKNOWN:
2523 	    case VAR_DICT:
2524 	    case VAR_FUNC:
2525 	    case VAR_PARTIAL:
2526 	    case VAR_SPECIAL:
2527 	    case VAR_JOB:
2528 	    case VAR_CHANNEL:
2529 		break;
2530 
2531 	    case VAR_BLOB:
2532 		if (*op != '+' || tv2->v_type != VAR_BLOB)
2533 		    break;
2534 		// BLOB += BLOB
2535 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
2536 		{
2537 		    blob_T  *b1 = tv1->vval.v_blob;
2538 		    blob_T  *b2 = tv2->vval.v_blob;
2539 		    int	i, len = blob_len(b2);
2540 		    for (i = 0; i < len; i++)
2541 			ga_append(&b1->bv_ga, blob_get(b2, i));
2542 		}
2543 		return OK;
2544 
2545 	    case VAR_LIST:
2546 		if (*op != '+' || tv2->v_type != VAR_LIST)
2547 		    break;
2548 		// List += List
2549 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
2550 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
2551 		return OK;
2552 
2553 	    case VAR_NUMBER:
2554 	    case VAR_STRING:
2555 		if (tv2->v_type == VAR_LIST)
2556 		    break;
2557 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
2558 		{
2559 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
2560 		    n = tv_get_number(tv1);
2561 #ifdef FEAT_FLOAT
2562 		    if (tv2->v_type == VAR_FLOAT)
2563 		    {
2564 			float_T f = n;
2565 
2566 			if (*op == '%')
2567 			    break;
2568 			switch (*op)
2569 			{
2570 			    case '+': f += tv2->vval.v_float; break;
2571 			    case '-': f -= tv2->vval.v_float; break;
2572 			    case '*': f *= tv2->vval.v_float; break;
2573 			    case '/': f /= tv2->vval.v_float; break;
2574 			}
2575 			clear_tv(tv1);
2576 			tv1->v_type = VAR_FLOAT;
2577 			tv1->vval.v_float = f;
2578 		    }
2579 		    else
2580 #endif
2581 		    {
2582 			switch (*op)
2583 			{
2584 			    case '+': n += tv_get_number(tv2); break;
2585 			    case '-': n -= tv_get_number(tv2); break;
2586 			    case '*': n *= tv_get_number(tv2); break;
2587 			    case '/': n = num_divide(n, tv_get_number(tv2)); break;
2588 			    case '%': n = num_modulus(n, tv_get_number(tv2)); break;
2589 			}
2590 			clear_tv(tv1);
2591 			tv1->v_type = VAR_NUMBER;
2592 			tv1->vval.v_number = n;
2593 		    }
2594 		}
2595 		else
2596 		{
2597 		    if (tv2->v_type == VAR_FLOAT)
2598 			break;
2599 
2600 		    // str .= str
2601 		    s = tv_get_string(tv1);
2602 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
2603 		    clear_tv(tv1);
2604 		    tv1->v_type = VAR_STRING;
2605 		    tv1->vval.v_string = s;
2606 		}
2607 		return OK;
2608 
2609 	    case VAR_FLOAT:
2610 #ifdef FEAT_FLOAT
2611 		{
2612 		    float_T f;
2613 
2614 		    if (*op == '%' || *op == '.'
2615 				   || (tv2->v_type != VAR_FLOAT
2616 				    && tv2->v_type != VAR_NUMBER
2617 				    && tv2->v_type != VAR_STRING))
2618 			break;
2619 		    if (tv2->v_type == VAR_FLOAT)
2620 			f = tv2->vval.v_float;
2621 		    else
2622 			f = tv_get_number(tv2);
2623 		    switch (*op)
2624 		    {
2625 			case '+': tv1->vval.v_float += f; break;
2626 			case '-': tv1->vval.v_float -= f; break;
2627 			case '*': tv1->vval.v_float *= f; break;
2628 			case '/': tv1->vval.v_float /= f; break;
2629 		    }
2630 		}
2631 #endif
2632 		return OK;
2633 	}
2634     }
2635 
2636     semsg(_(e_letwrong), op);
2637     return FAIL;
2638 }
2639 
2640 /*
2641  * Evaluate the expression used in a ":for var in expr" command.
2642  * "arg" points to "var".
2643  * Set "*errp" to TRUE for an error, FALSE otherwise;
2644  * Return a pointer that holds the info.  Null when there is an error.
2645  */
2646     void *
2647 eval_for_line(
2648     char_u	*arg,
2649     int		*errp,
2650     char_u	**nextcmdp,
2651     int		skip)
2652 {
2653     forinfo_T	*fi;
2654     char_u	*expr;
2655     typval_T	tv;
2656     list_T	*l;
2657 
2658     *errp = TRUE;	/* default: there is an error */
2659 
2660     fi = (forinfo_T *)alloc_clear(sizeof(forinfo_T));
2661     if (fi == NULL)
2662 	return NULL;
2663 
2664     expr = skip_var_list(arg, &fi->fi_varcount, &fi->fi_semicolon);
2665     if (expr == NULL)
2666 	return fi;
2667 
2668     expr = skipwhite(expr);
2669     if (expr[0] != 'i' || expr[1] != 'n' || !VIM_ISWHITE(expr[2]))
2670     {
2671 	emsg(_("E690: Missing \"in\" after :for"));
2672 	return fi;
2673     }
2674 
2675     if (skip)
2676 	++emsg_skip;
2677     if (eval0(skipwhite(expr + 2), &tv, nextcmdp, !skip) == OK)
2678     {
2679 	*errp = FALSE;
2680 	if (!skip)
2681 	{
2682 	    if (tv.v_type == VAR_LIST)
2683 	    {
2684 		l = tv.vval.v_list;
2685 		if (l == NULL)
2686 		{
2687 		    // a null list is like an empty list: do nothing
2688 		    clear_tv(&tv);
2689 		}
2690 		else
2691 		{
2692 		    // No need to increment the refcount, it's already set for
2693 		    // the list being used in "tv".
2694 		    fi->fi_list = l;
2695 		    list_add_watch(l, &fi->fi_lw);
2696 		    fi->fi_lw.lw_item = l->lv_first;
2697 		}
2698 	    }
2699 	    else if (tv.v_type == VAR_BLOB)
2700 	    {
2701 		fi->fi_bi = 0;
2702 		if (tv.vval.v_blob != NULL)
2703 		{
2704 		    typval_T btv;
2705 
2706 		    // Make a copy, so that the iteration still works when the
2707 		    // blob is changed.
2708 		    blob_copy(&tv, &btv);
2709 		    fi->fi_blob = btv.vval.v_blob;
2710 		}
2711 		clear_tv(&tv);
2712 	    }
2713 	    else
2714 	    {
2715 		emsg(_(e_listreq));
2716 		clear_tv(&tv);
2717 	    }
2718 	}
2719     }
2720     if (skip)
2721 	--emsg_skip;
2722 
2723     return fi;
2724 }
2725 
2726 /*
2727  * Use the first item in a ":for" list.  Advance to the next.
2728  * Assign the values to the variable (list).  "arg" points to the first one.
2729  * Return TRUE when a valid item was found, FALSE when at end of list or
2730  * something wrong.
2731  */
2732     int
2733 next_for_item(void *fi_void, char_u *arg)
2734 {
2735     forinfo_T	*fi = (forinfo_T *)fi_void;
2736     int		result;
2737     listitem_T	*item;
2738 
2739     if (fi->fi_blob != NULL)
2740     {
2741 	typval_T	tv;
2742 
2743 	if (fi->fi_bi >= blob_len(fi->fi_blob))
2744 	    return FALSE;
2745 	tv.v_type = VAR_NUMBER;
2746 	tv.v_lock = VAR_FIXED;
2747 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
2748 	++fi->fi_bi;
2749 	return ex_let_vars(arg, &tv, TRUE,
2750 			      fi->fi_semicolon, fi->fi_varcount, NULL) == OK;
2751     }
2752 
2753     item = fi->fi_lw.lw_item;
2754     if (item == NULL)
2755 	result = FALSE;
2756     else
2757     {
2758 	fi->fi_lw.lw_item = item->li_next;
2759 	result = (ex_let_vars(arg, &item->li_tv, TRUE,
2760 			      fi->fi_semicolon, fi->fi_varcount, NULL) == OK);
2761     }
2762     return result;
2763 }
2764 
2765 /*
2766  * Free the structure used to store info used by ":for".
2767  */
2768     void
2769 free_for_info(void *fi_void)
2770 {
2771     forinfo_T    *fi = (forinfo_T *)fi_void;
2772 
2773     if (fi != NULL && fi->fi_list != NULL)
2774     {
2775 	list_rem_watch(fi->fi_list, &fi->fi_lw);
2776 	list_unref(fi->fi_list);
2777     }
2778     if (fi != NULL && fi->fi_blob != NULL)
2779 	blob_unref(fi->fi_blob);
2780     vim_free(fi);
2781 }
2782 
2783 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
2784 
2785     void
2786 set_context_for_expression(
2787     expand_T	*xp,
2788     char_u	*arg,
2789     cmdidx_T	cmdidx)
2790 {
2791     int		got_eq = FALSE;
2792     int		c;
2793     char_u	*p;
2794 
2795     if (cmdidx == CMD_let)
2796     {
2797 	xp->xp_context = EXPAND_USER_VARS;
2798 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
2799 	{
2800 	    /* ":let var1 var2 ...": find last space. */
2801 	    for (p = arg + STRLEN(arg); p >= arg; )
2802 	    {
2803 		xp->xp_pattern = p;
2804 		MB_PTR_BACK(arg, p);
2805 		if (VIM_ISWHITE(*p))
2806 		    break;
2807 	    }
2808 	    return;
2809 	}
2810     }
2811     else
2812 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
2813 							  : EXPAND_EXPRESSION;
2814     while ((xp->xp_pattern = vim_strpbrk(arg,
2815 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
2816     {
2817 	c = *xp->xp_pattern;
2818 	if (c == '&')
2819 	{
2820 	    c = xp->xp_pattern[1];
2821 	    if (c == '&')
2822 	    {
2823 		++xp->xp_pattern;
2824 		xp->xp_context = cmdidx != CMD_let || got_eq
2825 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
2826 	    }
2827 	    else if (c != ' ')
2828 	    {
2829 		xp->xp_context = EXPAND_SETTINGS;
2830 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
2831 		    xp->xp_pattern += 2;
2832 
2833 	    }
2834 	}
2835 	else if (c == '$')
2836 	{
2837 	    /* environment variable */
2838 	    xp->xp_context = EXPAND_ENV_VARS;
2839 	}
2840 	else if (c == '=')
2841 	{
2842 	    got_eq = TRUE;
2843 	    xp->xp_context = EXPAND_EXPRESSION;
2844 	}
2845 	else if (c == '#'
2846 		&& xp->xp_context == EXPAND_EXPRESSION)
2847 	{
2848 	    /* Autoload function/variable contains '#'. */
2849 	    break;
2850 	}
2851 	else if ((c == '<' || c == '#')
2852 		&& xp->xp_context == EXPAND_FUNCTIONS
2853 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
2854 	{
2855 	    /* Function name can start with "<SNR>" and contain '#'. */
2856 	    break;
2857 	}
2858 	else if (cmdidx != CMD_let || got_eq)
2859 	{
2860 	    if (c == '"')	    /* string */
2861 	    {
2862 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
2863 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
2864 			++xp->xp_pattern;
2865 		xp->xp_context = EXPAND_NOTHING;
2866 	    }
2867 	    else if (c == '\'')	    /* literal string */
2868 	    {
2869 		/* Trick: '' is like stopping and starting a literal string. */
2870 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
2871 		    /* skip */ ;
2872 		xp->xp_context = EXPAND_NOTHING;
2873 	    }
2874 	    else if (c == '|')
2875 	    {
2876 		if (xp->xp_pattern[1] == '|')
2877 		{
2878 		    ++xp->xp_pattern;
2879 		    xp->xp_context = EXPAND_EXPRESSION;
2880 		}
2881 		else
2882 		    xp->xp_context = EXPAND_COMMANDS;
2883 	    }
2884 	    else
2885 		xp->xp_context = EXPAND_EXPRESSION;
2886 	}
2887 	else
2888 	    /* Doesn't look like something valid, expand as an expression
2889 	     * anyway. */
2890 	    xp->xp_context = EXPAND_EXPRESSION;
2891 	arg = xp->xp_pattern;
2892 	if (*arg != NUL)
2893 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
2894 		/* skip */ ;
2895     }
2896     xp->xp_pattern = arg;
2897 }
2898 
2899 #endif /* FEAT_CMDL_COMPL */
2900 
2901 /*
2902  * ":unlet[!] var1 ... " command.
2903  */
2904     void
2905 ex_unlet(exarg_T *eap)
2906 {
2907     ex_unletlock(eap, eap->arg, 0);
2908 }
2909 
2910 /*
2911  * ":lockvar" and ":unlockvar" commands
2912  */
2913     void
2914 ex_lockvar(exarg_T *eap)
2915 {
2916     char_u	*arg = eap->arg;
2917     int		deep = 2;
2918 
2919     if (eap->forceit)
2920 	deep = -1;
2921     else if (vim_isdigit(*arg))
2922     {
2923 	deep = getdigits(&arg);
2924 	arg = skipwhite(arg);
2925     }
2926 
2927     ex_unletlock(eap, arg, deep);
2928 }
2929 
2930 /*
2931  * ":unlet", ":lockvar" and ":unlockvar" are quite similar.
2932  */
2933     static void
2934 ex_unletlock(
2935     exarg_T	*eap,
2936     char_u	*argstart,
2937     int		deep)
2938 {
2939     char_u	*arg = argstart;
2940     char_u	*name_end;
2941     int		error = FALSE;
2942     lval_T	lv;
2943 
2944     do
2945     {
2946 	if (*arg == '$')
2947 	{
2948 	    char_u    *name = ++arg;
2949 
2950 	    if (get_env_len(&arg) == 0)
2951 	    {
2952 		semsg(_(e_invarg2), name - 1);
2953 		return;
2954 	    }
2955 	    vim_unsetenv(name);
2956 	    arg = skipwhite(arg);
2957 	    continue;
2958 	}
2959 
2960 	/* Parse the name and find the end. */
2961 	name_end = get_lval(arg, NULL, &lv, TRUE, eap->skip || error, 0,
2962 							     FNE_CHECK_START);
2963 	if (lv.ll_name == NULL)
2964 	    error = TRUE;	    /* error but continue parsing */
2965 	if (name_end == NULL || (!VIM_ISWHITE(*name_end)
2966 						   && !ends_excmd(*name_end)))
2967 	{
2968 	    if (name_end != NULL)
2969 	    {
2970 		emsg_severe = TRUE;
2971 		emsg(_(e_trailing));
2972 	    }
2973 	    if (!(eap->skip || error))
2974 		clear_lval(&lv);
2975 	    break;
2976 	}
2977 
2978 	if (!error && !eap->skip)
2979 	{
2980 	    if (eap->cmdidx == CMD_unlet)
2981 	    {
2982 		if (do_unlet_var(&lv, name_end, eap->forceit) == FAIL)
2983 		    error = TRUE;
2984 	    }
2985 	    else
2986 	    {
2987 		if (do_lock_var(&lv, name_end, deep,
2988 					  eap->cmdidx == CMD_lockvar) == FAIL)
2989 		    error = TRUE;
2990 	    }
2991 	}
2992 
2993 	if (!eap->skip)
2994 	    clear_lval(&lv);
2995 
2996 	arg = skipwhite(name_end);
2997     } while (!ends_excmd(*arg));
2998 
2999     eap->nextcmd = check_nextcmd(arg);
3000 }
3001 
3002     static int
3003 do_unlet_var(
3004     lval_T	*lp,
3005     char_u	*name_end,
3006     int		forceit)
3007 {
3008     int		ret = OK;
3009     int		cc;
3010 
3011     if (lp->ll_tv == NULL)
3012     {
3013 	cc = *name_end;
3014 	*name_end = NUL;
3015 
3016 	/* Normal name or expanded name. */
3017 	if (do_unlet(lp->ll_name, forceit) == FAIL)
3018 	    ret = FAIL;
3019 	*name_end = cc;
3020     }
3021     else if ((lp->ll_list != NULL
3022 		 && var_check_lock(lp->ll_list->lv_lock, lp->ll_name, FALSE))
3023 	    || (lp->ll_dict != NULL
3024 		 && var_check_lock(lp->ll_dict->dv_lock, lp->ll_name, FALSE)))
3025 	return FAIL;
3026     else if (lp->ll_range)
3027     {
3028 	listitem_T    *li;
3029 	listitem_T    *ll_li = lp->ll_li;
3030 	int	      ll_n1 = lp->ll_n1;
3031 
3032 	while (ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= ll_n1))
3033 	{
3034 	    li = ll_li->li_next;
3035 	    if (var_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
3036 		return FAIL;
3037 	    ll_li = li;
3038 	    ++ll_n1;
3039 	}
3040 
3041 	/* Delete a range of List items. */
3042 	while (lp->ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
3043 	{
3044 	    li = lp->ll_li->li_next;
3045 	    listitem_remove(lp->ll_list, lp->ll_li);
3046 	    lp->ll_li = li;
3047 	    ++lp->ll_n1;
3048 	}
3049     }
3050     else
3051     {
3052 	if (lp->ll_list != NULL)
3053 	    /* unlet a List item. */
3054 	    listitem_remove(lp->ll_list, lp->ll_li);
3055 	else
3056 	    /* unlet a Dictionary item. */
3057 	    dictitem_remove(lp->ll_dict, lp->ll_di);
3058     }
3059 
3060     return ret;
3061 }
3062 
3063 /*
3064  * "unlet" a variable.  Return OK if it existed, FAIL if not.
3065  * When "forceit" is TRUE don't complain if the variable doesn't exist.
3066  */
3067     int
3068 do_unlet(char_u *name, int forceit)
3069 {
3070     hashtab_T	*ht;
3071     hashitem_T	*hi;
3072     char_u	*varname;
3073     dict_T	*d;
3074     dictitem_T	*di;
3075 
3076     ht = find_var_ht(name, &varname);
3077     if (ht != NULL && *varname != NUL)
3078     {
3079 	d = get_current_funccal_dict(ht);
3080 	if (d == NULL)
3081 	{
3082 	    if (ht == &globvarht)
3083 		d = &globvardict;
3084 	    else if (ht == &compat_hashtab)
3085 		d = &vimvardict;
3086 	    else
3087 	    {
3088 		di = find_var_in_ht(ht, *name, (char_u *)"", FALSE);
3089 		d = di == NULL ? NULL : di->di_tv.vval.v_dict;
3090 	    }
3091 	    if (d == NULL)
3092 	    {
3093 		internal_error("do_unlet()");
3094 		return FAIL;
3095 	    }
3096 	}
3097 	hi = hash_find(ht, varname);
3098 	if (HASHITEM_EMPTY(hi))
3099 	    hi = find_hi_in_scoped_ht(name, &ht);
3100 	if (hi != NULL && !HASHITEM_EMPTY(hi))
3101 	{
3102 	    di = HI2DI(hi);
3103 	    if (var_check_fixed(di->di_flags, name, FALSE)
3104 		    || var_check_ro(di->di_flags, name, FALSE)
3105 		    || var_check_lock(d->dv_lock, name, FALSE))
3106 		return FAIL;
3107 
3108 	    delete_var(ht, hi);
3109 	    return OK;
3110 	}
3111     }
3112     if (forceit)
3113 	return OK;
3114     semsg(_("E108: No such variable: \"%s\""), name);
3115     return FAIL;
3116 }
3117 
3118 /*
3119  * Lock or unlock variable indicated by "lp".
3120  * "deep" is the levels to go (-1 for unlimited);
3121  * "lock" is TRUE for ":lockvar", FALSE for ":unlockvar".
3122  */
3123     static int
3124 do_lock_var(
3125     lval_T	*lp,
3126     char_u	*name_end,
3127     int		deep,
3128     int		lock)
3129 {
3130     int		ret = OK;
3131     int		cc;
3132     dictitem_T	*di;
3133 
3134     if (deep == 0)	/* nothing to do */
3135 	return OK;
3136 
3137     if (lp->ll_tv == NULL)
3138     {
3139 	cc = *name_end;
3140 	*name_end = NUL;
3141 
3142 	/* Normal name or expanded name. */
3143 	di = find_var(lp->ll_name, NULL, TRUE);
3144 	if (di == NULL)
3145 	    ret = FAIL;
3146 	else if ((di->di_flags & DI_FLAGS_FIX)
3147 			&& di->di_tv.v_type != VAR_DICT
3148 			&& di->di_tv.v_type != VAR_LIST)
3149 	    /* For historic reasons this error is not given for a list or dict.
3150 	     * E.g., the b: dict could be locked/unlocked. */
3151 	    semsg(_("E940: Cannot lock or unlock variable %s"), lp->ll_name);
3152 	else
3153 	{
3154 	    if (lock)
3155 		di->di_flags |= DI_FLAGS_LOCK;
3156 	    else
3157 		di->di_flags &= ~DI_FLAGS_LOCK;
3158 	    item_lock(&di->di_tv, deep, lock);
3159 	}
3160 	*name_end = cc;
3161     }
3162     else if (lp->ll_range)
3163     {
3164 	listitem_T    *li = lp->ll_li;
3165 
3166 	/* (un)lock a range of List items. */
3167 	while (li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
3168 	{
3169 	    item_lock(&li->li_tv, deep, lock);
3170 	    li = li->li_next;
3171 	    ++lp->ll_n1;
3172 	}
3173     }
3174     else if (lp->ll_list != NULL)
3175 	/* (un)lock a List item. */
3176 	item_lock(&lp->ll_li->li_tv, deep, lock);
3177     else
3178 	/* (un)lock a Dictionary item. */
3179 	item_lock(&lp->ll_di->di_tv, deep, lock);
3180 
3181     return ret;
3182 }
3183 
3184 /*
3185  * Lock or unlock an item.  "deep" is nr of levels to go.
3186  */
3187     static void
3188 item_lock(typval_T *tv, int deep, int lock)
3189 {
3190     static int	recurse = 0;
3191     list_T	*l;
3192     listitem_T	*li;
3193     dict_T	*d;
3194     blob_T	*b;
3195     hashitem_T	*hi;
3196     int		todo;
3197 
3198     if (recurse >= DICT_MAXNEST)
3199     {
3200 	emsg(_("E743: variable nested too deep for (un)lock"));
3201 	return;
3202     }
3203     if (deep == 0)
3204 	return;
3205     ++recurse;
3206 
3207     /* lock/unlock the item itself */
3208     if (lock)
3209 	tv->v_lock |= VAR_LOCKED;
3210     else
3211 	tv->v_lock &= ~VAR_LOCKED;
3212 
3213     switch (tv->v_type)
3214     {
3215 	case VAR_UNKNOWN:
3216 	case VAR_NUMBER:
3217 	case VAR_STRING:
3218 	case VAR_FUNC:
3219 	case VAR_PARTIAL:
3220 	case VAR_FLOAT:
3221 	case VAR_SPECIAL:
3222 	case VAR_JOB:
3223 	case VAR_CHANNEL:
3224 	    break;
3225 
3226 	case VAR_BLOB:
3227 	    if ((b = tv->vval.v_blob) != NULL)
3228 	    {
3229 		if (lock)
3230 		    b->bv_lock |= VAR_LOCKED;
3231 		else
3232 		    b->bv_lock &= ~VAR_LOCKED;
3233 	    }
3234 	    break;
3235 	case VAR_LIST:
3236 	    if ((l = tv->vval.v_list) != NULL)
3237 	    {
3238 		if (lock)
3239 		    l->lv_lock |= VAR_LOCKED;
3240 		else
3241 		    l->lv_lock &= ~VAR_LOCKED;
3242 		if (deep < 0 || deep > 1)
3243 		    /* recursive: lock/unlock the items the List contains */
3244 		    for (li = l->lv_first; li != NULL; li = li->li_next)
3245 			item_lock(&li->li_tv, deep - 1, lock);
3246 	    }
3247 	    break;
3248 	case VAR_DICT:
3249 	    if ((d = tv->vval.v_dict) != NULL)
3250 	    {
3251 		if (lock)
3252 		    d->dv_lock |= VAR_LOCKED;
3253 		else
3254 		    d->dv_lock &= ~VAR_LOCKED;
3255 		if (deep < 0 || deep > 1)
3256 		{
3257 		    /* recursive: lock/unlock the items the List contains */
3258 		    todo = (int)d->dv_hashtab.ht_used;
3259 		    for (hi = d->dv_hashtab.ht_array; todo > 0; ++hi)
3260 		    {
3261 			if (!HASHITEM_EMPTY(hi))
3262 			{
3263 			    --todo;
3264 			    item_lock(&HI2DI(hi)->di_tv, deep - 1, lock);
3265 			}
3266 		    }
3267 		}
3268 	    }
3269     }
3270     --recurse;
3271 }
3272 
3273 #if (defined(FEAT_MENU) && defined(FEAT_MULTI_LANG)) || defined(PROTO)
3274 /*
3275  * Delete all "menutrans_" variables.
3276  */
3277     void
3278 del_menutrans_vars(void)
3279 {
3280     hashitem_T	*hi;
3281     int		todo;
3282 
3283     hash_lock(&globvarht);
3284     todo = (int)globvarht.ht_used;
3285     for (hi = globvarht.ht_array; todo > 0 && !got_int; ++hi)
3286     {
3287 	if (!HASHITEM_EMPTY(hi))
3288 	{
3289 	    --todo;
3290 	    if (STRNCMP(HI2DI(hi)->di_key, "menutrans_", 10) == 0)
3291 		delete_var(&globvarht, hi);
3292 	}
3293     }
3294     hash_unlock(&globvarht);
3295 }
3296 #endif
3297 
3298 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
3299 
3300 /*
3301  * Local string buffer for the next two functions to store a variable name
3302  * with its prefix. Allocated in cat_prefix_varname(), freed later in
3303  * get_user_var_name().
3304  */
3305 
3306 static char_u	*varnamebuf = NULL;
3307 static int	varnamebuflen = 0;
3308 
3309 /*
3310  * Function to concatenate a prefix and a variable name.
3311  */
3312     static char_u *
3313 cat_prefix_varname(int prefix, char_u *name)
3314 {
3315     int		len;
3316 
3317     len = (int)STRLEN(name) + 3;
3318     if (len > varnamebuflen)
3319     {
3320 	vim_free(varnamebuf);
3321 	len += 10;			/* some additional space */
3322 	varnamebuf = alloc(len);
3323 	if (varnamebuf == NULL)
3324 	{
3325 	    varnamebuflen = 0;
3326 	    return NULL;
3327 	}
3328 	varnamebuflen = len;
3329     }
3330     *varnamebuf = prefix;
3331     varnamebuf[1] = ':';
3332     STRCPY(varnamebuf + 2, name);
3333     return varnamebuf;
3334 }
3335 
3336 /*
3337  * Function given to ExpandGeneric() to obtain the list of user defined
3338  * (global/buffer/window/built-in) variable names.
3339  */
3340     char_u *
3341 get_user_var_name(expand_T *xp, int idx)
3342 {
3343     static long_u	gdone;
3344     static long_u	bdone;
3345     static long_u	wdone;
3346     static long_u	tdone;
3347     static int		vidx;
3348     static hashitem_T	*hi;
3349     hashtab_T		*ht;
3350 
3351     if (idx == 0)
3352     {
3353 	gdone = bdone = wdone = vidx = 0;
3354 	tdone = 0;
3355     }
3356 
3357     /* Global variables */
3358     if (gdone < globvarht.ht_used)
3359     {
3360 	if (gdone++ == 0)
3361 	    hi = globvarht.ht_array;
3362 	else
3363 	    ++hi;
3364 	while (HASHITEM_EMPTY(hi))
3365 	    ++hi;
3366 	if (STRNCMP("g:", xp->xp_pattern, 2) == 0)
3367 	    return cat_prefix_varname('g', hi->hi_key);
3368 	return hi->hi_key;
3369     }
3370 
3371     /* b: variables */
3372     ht = &curbuf->b_vars->dv_hashtab;
3373     if (bdone < ht->ht_used)
3374     {
3375 	if (bdone++ == 0)
3376 	    hi = ht->ht_array;
3377 	else
3378 	    ++hi;
3379 	while (HASHITEM_EMPTY(hi))
3380 	    ++hi;
3381 	return cat_prefix_varname('b', hi->hi_key);
3382     }
3383 
3384     /* w: variables */
3385     ht = &curwin->w_vars->dv_hashtab;
3386     if (wdone < ht->ht_used)
3387     {
3388 	if (wdone++ == 0)
3389 	    hi = ht->ht_array;
3390 	else
3391 	    ++hi;
3392 	while (HASHITEM_EMPTY(hi))
3393 	    ++hi;
3394 	return cat_prefix_varname('w', hi->hi_key);
3395     }
3396 
3397     /* t: variables */
3398     ht = &curtab->tp_vars->dv_hashtab;
3399     if (tdone < ht->ht_used)
3400     {
3401 	if (tdone++ == 0)
3402 	    hi = ht->ht_array;
3403 	else
3404 	    ++hi;
3405 	while (HASHITEM_EMPTY(hi))
3406 	    ++hi;
3407 	return cat_prefix_varname('t', hi->hi_key);
3408     }
3409 
3410     /* v: variables */
3411     if (vidx < VV_LEN)
3412 	return cat_prefix_varname('v', (char_u *)vimvars[vidx++].vv_name);
3413 
3414     VIM_CLEAR(varnamebuf);
3415     varnamebuflen = 0;
3416     return NULL;
3417 }
3418 
3419 #endif /* FEAT_CMDL_COMPL */
3420 
3421 /*
3422  * Return TRUE if "pat" matches "text".
3423  * Does not use 'cpo' and always uses 'magic'.
3424  */
3425     static int
3426 pattern_match(char_u *pat, char_u *text, int ic)
3427 {
3428     int		matches = FALSE;
3429     char_u	*save_cpo;
3430     regmatch_T	regmatch;
3431 
3432     /* avoid 'l' flag in 'cpoptions' */
3433     save_cpo = p_cpo;
3434     p_cpo = (char_u *)"";
3435     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
3436     if (regmatch.regprog != NULL)
3437     {
3438 	regmatch.rm_ic = ic;
3439 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
3440 	vim_regfree(regmatch.regprog);
3441     }
3442     p_cpo = save_cpo;
3443     return matches;
3444 }
3445 
3446 /*
3447  * The "evaluate" argument: When FALSE, the argument is only parsed but not
3448  * executed.  The function may return OK, but the rettv will be of type
3449  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
3450  */
3451 
3452 /*
3453  * Handle zero level expression.
3454  * This calls eval1() and handles error message and nextcmd.
3455  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
3456  * Note: "rettv.v_lock" is not set.
3457  * Return OK or FAIL.
3458  */
3459     int
3460 eval0(
3461     char_u	*arg,
3462     typval_T	*rettv,
3463     char_u	**nextcmd,
3464     int		evaluate)
3465 {
3466     int		ret;
3467     char_u	*p;
3468     int		did_emsg_before = did_emsg;
3469     int		called_emsg_before = called_emsg;
3470 
3471     p = skipwhite(arg);
3472     ret = eval1(&p, rettv, evaluate);
3473     if (ret == FAIL || !ends_excmd(*p))
3474     {
3475 	if (ret != FAIL)
3476 	    clear_tv(rettv);
3477 	/*
3478 	 * Report the invalid expression unless the expression evaluation has
3479 	 * been cancelled due to an aborting error, an interrupt, or an
3480 	 * exception, or we already gave a more specific error.
3481 	 * Also check called_emsg for when using assert_fails().
3482 	 */
3483 	if (!aborting() && did_emsg == did_emsg_before
3484 					  && called_emsg == called_emsg_before)
3485 	    semsg(_(e_invexpr2), arg);
3486 	ret = FAIL;
3487     }
3488     if (nextcmd != NULL)
3489 	*nextcmd = check_nextcmd(p);
3490 
3491     return ret;
3492 }
3493 
3494 /*
3495  * Handle top level expression:
3496  *	expr2 ? expr1 : expr1
3497  *
3498  * "arg" must point to the first non-white of the expression.
3499  * "arg" is advanced to the next non-white after the recognized expression.
3500  *
3501  * Note: "rettv.v_lock" is not set.
3502  *
3503  * Return OK or FAIL.
3504  */
3505     int
3506 eval1(char_u **arg, typval_T *rettv, int evaluate)
3507 {
3508     int		result;
3509     typval_T	var2;
3510 
3511     /*
3512      * Get the first variable.
3513      */
3514     if (eval2(arg, rettv, evaluate) == FAIL)
3515 	return FAIL;
3516 
3517     if ((*arg)[0] == '?')
3518     {
3519 	result = FALSE;
3520 	if (evaluate)
3521 	{
3522 	    int		error = FALSE;
3523 
3524 	    if (tv_get_number_chk(rettv, &error) != 0)
3525 		result = TRUE;
3526 	    clear_tv(rettv);
3527 	    if (error)
3528 		return FAIL;
3529 	}
3530 
3531 	/*
3532 	 * Get the second variable.
3533 	 */
3534 	*arg = skipwhite(*arg + 1);
3535 	if (eval1(arg, rettv, evaluate && result) == FAIL) /* recursive! */
3536 	    return FAIL;
3537 
3538 	/*
3539 	 * Check for the ":".
3540 	 */
3541 	if ((*arg)[0] != ':')
3542 	{
3543 	    emsg(_("E109: Missing ':' after '?'"));
3544 	    if (evaluate && result)
3545 		clear_tv(rettv);
3546 	    return FAIL;
3547 	}
3548 
3549 	/*
3550 	 * Get the third variable.
3551 	 */
3552 	*arg = skipwhite(*arg + 1);
3553 	if (eval1(arg, &var2, evaluate && !result) == FAIL) /* recursive! */
3554 	{
3555 	    if (evaluate && result)
3556 		clear_tv(rettv);
3557 	    return FAIL;
3558 	}
3559 	if (evaluate && !result)
3560 	    *rettv = var2;
3561     }
3562 
3563     return OK;
3564 }
3565 
3566 /*
3567  * Handle first level expression:
3568  *	expr2 || expr2 || expr2	    logical OR
3569  *
3570  * "arg" must point to the first non-white of the expression.
3571  * "arg" is advanced to the next non-white after the recognized expression.
3572  *
3573  * Return OK or FAIL.
3574  */
3575     static int
3576 eval2(char_u **arg, typval_T *rettv, int evaluate)
3577 {
3578     typval_T	var2;
3579     long	result;
3580     int		first;
3581     int		error = FALSE;
3582 
3583     /*
3584      * Get the first variable.
3585      */
3586     if (eval3(arg, rettv, evaluate) == FAIL)
3587 	return FAIL;
3588 
3589     /*
3590      * Repeat until there is no following "||".
3591      */
3592     first = TRUE;
3593     result = FALSE;
3594     while ((*arg)[0] == '|' && (*arg)[1] == '|')
3595     {
3596 	if (evaluate && first)
3597 	{
3598 	    if (tv_get_number_chk(rettv, &error) != 0)
3599 		result = TRUE;
3600 	    clear_tv(rettv);
3601 	    if (error)
3602 		return FAIL;
3603 	    first = FALSE;
3604 	}
3605 
3606 	/*
3607 	 * Get the second variable.
3608 	 */
3609 	*arg = skipwhite(*arg + 2);
3610 	if (eval3(arg, &var2, evaluate && !result) == FAIL)
3611 	    return FAIL;
3612 
3613 	/*
3614 	 * Compute the result.
3615 	 */
3616 	if (evaluate && !result)
3617 	{
3618 	    if (tv_get_number_chk(&var2, &error) != 0)
3619 		result = TRUE;
3620 	    clear_tv(&var2);
3621 	    if (error)
3622 		return FAIL;
3623 	}
3624 	if (evaluate)
3625 	{
3626 	    rettv->v_type = VAR_NUMBER;
3627 	    rettv->vval.v_number = result;
3628 	}
3629     }
3630 
3631     return OK;
3632 }
3633 
3634 /*
3635  * Handle second level expression:
3636  *	expr3 && expr3 && expr3	    logical AND
3637  *
3638  * "arg" must point to the first non-white of the expression.
3639  * "arg" is advanced to the next non-white after the recognized expression.
3640  *
3641  * Return OK or FAIL.
3642  */
3643     static int
3644 eval3(char_u **arg, typval_T *rettv, int evaluate)
3645 {
3646     typval_T	var2;
3647     long	result;
3648     int		first;
3649     int		error = FALSE;
3650 
3651     /*
3652      * Get the first variable.
3653      */
3654     if (eval4(arg, rettv, evaluate) == FAIL)
3655 	return FAIL;
3656 
3657     /*
3658      * Repeat until there is no following "&&".
3659      */
3660     first = TRUE;
3661     result = TRUE;
3662     while ((*arg)[0] == '&' && (*arg)[1] == '&')
3663     {
3664 	if (evaluate && first)
3665 	{
3666 	    if (tv_get_number_chk(rettv, &error) == 0)
3667 		result = FALSE;
3668 	    clear_tv(rettv);
3669 	    if (error)
3670 		return FAIL;
3671 	    first = FALSE;
3672 	}
3673 
3674 	/*
3675 	 * Get the second variable.
3676 	 */
3677 	*arg = skipwhite(*arg + 2);
3678 	if (eval4(arg, &var2, evaluate && result) == FAIL)
3679 	    return FAIL;
3680 
3681 	/*
3682 	 * Compute the result.
3683 	 */
3684 	if (evaluate && result)
3685 	{
3686 	    if (tv_get_number_chk(&var2, &error) == 0)
3687 		result = FALSE;
3688 	    clear_tv(&var2);
3689 	    if (error)
3690 		return FAIL;
3691 	}
3692 	if (evaluate)
3693 	{
3694 	    rettv->v_type = VAR_NUMBER;
3695 	    rettv->vval.v_number = result;
3696 	}
3697     }
3698 
3699     return OK;
3700 }
3701 
3702 /*
3703  * Handle third level expression:
3704  *	var1 == var2
3705  *	var1 =~ var2
3706  *	var1 != var2
3707  *	var1 !~ var2
3708  *	var1 > var2
3709  *	var1 >= var2
3710  *	var1 < var2
3711  *	var1 <= var2
3712  *	var1 is var2
3713  *	var1 isnot var2
3714  *
3715  * "arg" must point to the first non-white of the expression.
3716  * "arg" is advanced to the next non-white after the recognized expression.
3717  *
3718  * Return OK or FAIL.
3719  */
3720     static int
3721 eval4(char_u **arg, typval_T *rettv, int evaluate)
3722 {
3723     typval_T	var2;
3724     char_u	*p;
3725     int		i;
3726     exptype_T	type = TYPE_UNKNOWN;
3727     int		type_is = FALSE;    /* TRUE for "is" and "isnot" */
3728     int		len = 2;
3729     int		ic;
3730 
3731     /*
3732      * Get the first variable.
3733      */
3734     if (eval5(arg, rettv, evaluate) == FAIL)
3735 	return FAIL;
3736 
3737     p = *arg;
3738     switch (p[0])
3739     {
3740 	case '=':   if (p[1] == '=')
3741 			type = TYPE_EQUAL;
3742 		    else if (p[1] == '~')
3743 			type = TYPE_MATCH;
3744 		    break;
3745 	case '!':   if (p[1] == '=')
3746 			type = TYPE_NEQUAL;
3747 		    else if (p[1] == '~')
3748 			type = TYPE_NOMATCH;
3749 		    break;
3750 	case '>':   if (p[1] != '=')
3751 		    {
3752 			type = TYPE_GREATER;
3753 			len = 1;
3754 		    }
3755 		    else
3756 			type = TYPE_GEQUAL;
3757 		    break;
3758 	case '<':   if (p[1] != '=')
3759 		    {
3760 			type = TYPE_SMALLER;
3761 			len = 1;
3762 		    }
3763 		    else
3764 			type = TYPE_SEQUAL;
3765 		    break;
3766 	case 'i':   if (p[1] == 's')
3767 		    {
3768 			if (p[2] == 'n' && p[3] == 'o' && p[4] == 't')
3769 			    len = 5;
3770 			i = p[len];
3771 			if (!isalnum(i) && i != '_')
3772 			{
3773 			    type = len == 2 ? TYPE_EQUAL : TYPE_NEQUAL;
3774 			    type_is = TRUE;
3775 			}
3776 		    }
3777 		    break;
3778     }
3779 
3780     /*
3781      * If there is a comparative operator, use it.
3782      */
3783     if (type != TYPE_UNKNOWN)
3784     {
3785 	/* extra question mark appended: ignore case */
3786 	if (p[len] == '?')
3787 	{
3788 	    ic = TRUE;
3789 	    ++len;
3790 	}
3791 	/* extra '#' appended: match case */
3792 	else if (p[len] == '#')
3793 	{
3794 	    ic = FALSE;
3795 	    ++len;
3796 	}
3797 	/* nothing appended: use 'ignorecase' */
3798 	else
3799 	    ic = p_ic;
3800 
3801 	/*
3802 	 * Get the second variable.
3803 	 */
3804 	*arg = skipwhite(p + len);
3805 	if (eval5(arg, &var2, evaluate) == FAIL)
3806 	{
3807 	    clear_tv(rettv);
3808 	    return FAIL;
3809 	}
3810 	if (evaluate)
3811 	{
3812 	    int ret = typval_compare(rettv, &var2, type, type_is, ic);
3813 
3814 	    clear_tv(&var2);
3815 	    return ret;
3816 	}
3817     }
3818 
3819     return OK;
3820 }
3821 
3822 /*
3823  * Handle fourth level expression:
3824  *	+	number addition
3825  *	-	number subtraction
3826  *	.	string concatenation (if script version is 1)
3827  *	..	string concatenation
3828  *
3829  * "arg" must point to the first non-white of the expression.
3830  * "arg" is advanced to the next non-white after the recognized expression.
3831  *
3832  * Return OK or FAIL.
3833  */
3834     static int
3835 eval5(char_u **arg, typval_T *rettv, int evaluate)
3836 {
3837     typval_T	var2;
3838     typval_T	var3;
3839     int		op;
3840     varnumber_T	n1, n2;
3841 #ifdef FEAT_FLOAT
3842     float_T	f1 = 0, f2 = 0;
3843 #endif
3844     char_u	*s1, *s2;
3845     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3846     char_u	*p;
3847     int		concat;
3848 
3849     /*
3850      * Get the first variable.
3851      */
3852     if (eval6(arg, rettv, evaluate, FALSE) == FAIL)
3853 	return FAIL;
3854 
3855     /*
3856      * Repeat computing, until no '+', '-' or '.' is following.
3857      */
3858     for (;;)
3859     {
3860 	// "." is only string concatenation when scriptversion is 1
3861 	op = **arg;
3862 	concat = op == '.'
3863 			&& (*(*arg + 1) == '.' || current_sctx.sc_version < 2);
3864 	if (op != '+' && op != '-' && !concat)
3865 	    break;
3866 
3867 	if ((op != '+' || (rettv->v_type != VAR_LIST
3868 						 && rettv->v_type != VAR_BLOB))
3869 #ifdef FEAT_FLOAT
3870 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
3871 #endif
3872 		)
3873 	{
3874 	    /* For "list + ...", an illegal use of the first operand as
3875 	     * a number cannot be determined before evaluating the 2nd
3876 	     * operand: if this is also a list, all is ok.
3877 	     * For "something . ...", "something - ..." or "non-list + ...",
3878 	     * we know that the first operand needs to be a string or number
3879 	     * without evaluating the 2nd operand.  So check before to avoid
3880 	     * side effects after an error. */
3881 	    if (evaluate && tv_get_string_chk(rettv) == NULL)
3882 	    {
3883 		clear_tv(rettv);
3884 		return FAIL;
3885 	    }
3886 	}
3887 
3888 	/*
3889 	 * Get the second variable.
3890 	 */
3891 	if (op == '.' && *(*arg + 1) == '.')  // .. string concatenation
3892 	    ++*arg;
3893 	*arg = skipwhite(*arg + 1);
3894 	if (eval6(arg, &var2, evaluate, op == '.') == FAIL)
3895 	{
3896 	    clear_tv(rettv);
3897 	    return FAIL;
3898 	}
3899 
3900 	if (evaluate)
3901 	{
3902 	    /*
3903 	     * Compute the result.
3904 	     */
3905 	    if (op == '.')
3906 	    {
3907 		s1 = tv_get_string_buf(rettv, buf1);	/* already checked */
3908 		s2 = tv_get_string_buf_chk(&var2, buf2);
3909 		if (s2 == NULL)		/* type error ? */
3910 		{
3911 		    clear_tv(rettv);
3912 		    clear_tv(&var2);
3913 		    return FAIL;
3914 		}
3915 		p = concat_str(s1, s2);
3916 		clear_tv(rettv);
3917 		rettv->v_type = VAR_STRING;
3918 		rettv->vval.v_string = p;
3919 	    }
3920 	    else if (op == '+' && rettv->v_type == VAR_BLOB
3921 						   && var2.v_type == VAR_BLOB)
3922 	    {
3923 		blob_T  *b1 = rettv->vval.v_blob;
3924 		blob_T  *b2 = var2.vval.v_blob;
3925 		blob_T	*b = blob_alloc();
3926 		int	i;
3927 
3928 		if (b != NULL)
3929 		{
3930 		    for (i = 0; i < blob_len(b1); i++)
3931 			ga_append(&b->bv_ga, blob_get(b1, i));
3932 		    for (i = 0; i < blob_len(b2); i++)
3933 			ga_append(&b->bv_ga, blob_get(b2, i));
3934 
3935 		    clear_tv(rettv);
3936 		    rettv_blob_set(rettv, b);
3937 		}
3938 	    }
3939 	    else if (op == '+' && rettv->v_type == VAR_LIST
3940 						   && var2.v_type == VAR_LIST)
3941 	    {
3942 		/* concatenate Lists */
3943 		if (list_concat(rettv->vval.v_list, var2.vval.v_list,
3944 							       &var3) == FAIL)
3945 		{
3946 		    clear_tv(rettv);
3947 		    clear_tv(&var2);
3948 		    return FAIL;
3949 		}
3950 		clear_tv(rettv);
3951 		*rettv = var3;
3952 	    }
3953 	    else
3954 	    {
3955 		int	    error = FALSE;
3956 
3957 #ifdef FEAT_FLOAT
3958 		if (rettv->v_type == VAR_FLOAT)
3959 		{
3960 		    f1 = rettv->vval.v_float;
3961 		    n1 = 0;
3962 		}
3963 		else
3964 #endif
3965 		{
3966 		    n1 = tv_get_number_chk(rettv, &error);
3967 		    if (error)
3968 		    {
3969 			/* This can only happen for "list + non-list".  For
3970 			 * "non-list + ..." or "something - ...", we returned
3971 			 * before evaluating the 2nd operand. */
3972 			clear_tv(rettv);
3973 			return FAIL;
3974 		    }
3975 #ifdef FEAT_FLOAT
3976 		    if (var2.v_type == VAR_FLOAT)
3977 			f1 = n1;
3978 #endif
3979 		}
3980 #ifdef FEAT_FLOAT
3981 		if (var2.v_type == VAR_FLOAT)
3982 		{
3983 		    f2 = var2.vval.v_float;
3984 		    n2 = 0;
3985 		}
3986 		else
3987 #endif
3988 		{
3989 		    n2 = tv_get_number_chk(&var2, &error);
3990 		    if (error)
3991 		    {
3992 			clear_tv(rettv);
3993 			clear_tv(&var2);
3994 			return FAIL;
3995 		    }
3996 #ifdef FEAT_FLOAT
3997 		    if (rettv->v_type == VAR_FLOAT)
3998 			f2 = n2;
3999 #endif
4000 		}
4001 		clear_tv(rettv);
4002 
4003 #ifdef FEAT_FLOAT
4004 		/* If there is a float on either side the result is a float. */
4005 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
4006 		{
4007 		    if (op == '+')
4008 			f1 = f1 + f2;
4009 		    else
4010 			f1 = f1 - f2;
4011 		    rettv->v_type = VAR_FLOAT;
4012 		    rettv->vval.v_float = f1;
4013 		}
4014 		else
4015 #endif
4016 		{
4017 		    if (op == '+')
4018 			n1 = n1 + n2;
4019 		    else
4020 			n1 = n1 - n2;
4021 		    rettv->v_type = VAR_NUMBER;
4022 		    rettv->vval.v_number = n1;
4023 		}
4024 	    }
4025 	    clear_tv(&var2);
4026 	}
4027     }
4028     return OK;
4029 }
4030 
4031 /*
4032  * Handle fifth level expression:
4033  *	*	number multiplication
4034  *	/	number division
4035  *	%	number modulo
4036  *
4037  * "arg" must point to the first non-white of the expression.
4038  * "arg" is advanced to the next non-white after the recognized expression.
4039  *
4040  * Return OK or FAIL.
4041  */
4042     static int
4043 eval6(
4044     char_u	**arg,
4045     typval_T	*rettv,
4046     int		evaluate,
4047     int		want_string)  /* after "." operator */
4048 {
4049     typval_T	var2;
4050     int		op;
4051     varnumber_T	n1, n2;
4052 #ifdef FEAT_FLOAT
4053     int		use_float = FALSE;
4054     float_T	f1 = 0, f2 = 0;
4055 #endif
4056     int		error = FALSE;
4057 
4058     /*
4059      * Get the first variable.
4060      */
4061     if (eval7(arg, rettv, evaluate, want_string) == FAIL)
4062 	return FAIL;
4063 
4064     /*
4065      * Repeat computing, until no '*', '/' or '%' is following.
4066      */
4067     for (;;)
4068     {
4069 	op = **arg;
4070 	if (op != '*' && op != '/' && op != '%')
4071 	    break;
4072 
4073 	if (evaluate)
4074 	{
4075 #ifdef FEAT_FLOAT
4076 	    if (rettv->v_type == VAR_FLOAT)
4077 	    {
4078 		f1 = rettv->vval.v_float;
4079 		use_float = TRUE;
4080 		n1 = 0;
4081 	    }
4082 	    else
4083 #endif
4084 		n1 = tv_get_number_chk(rettv, &error);
4085 	    clear_tv(rettv);
4086 	    if (error)
4087 		return FAIL;
4088 	}
4089 	else
4090 	    n1 = 0;
4091 
4092 	/*
4093 	 * Get the second variable.
4094 	 */
4095 	*arg = skipwhite(*arg + 1);
4096 	if (eval7(arg, &var2, evaluate, FALSE) == FAIL)
4097 	    return FAIL;
4098 
4099 	if (evaluate)
4100 	{
4101 #ifdef FEAT_FLOAT
4102 	    if (var2.v_type == VAR_FLOAT)
4103 	    {
4104 		if (!use_float)
4105 		{
4106 		    f1 = n1;
4107 		    use_float = TRUE;
4108 		}
4109 		f2 = var2.vval.v_float;
4110 		n2 = 0;
4111 	    }
4112 	    else
4113 #endif
4114 	    {
4115 		n2 = tv_get_number_chk(&var2, &error);
4116 		clear_tv(&var2);
4117 		if (error)
4118 		    return FAIL;
4119 #ifdef FEAT_FLOAT
4120 		if (use_float)
4121 		    f2 = n2;
4122 #endif
4123 	    }
4124 
4125 	    /*
4126 	     * Compute the result.
4127 	     * When either side is a float the result is a float.
4128 	     */
4129 #ifdef FEAT_FLOAT
4130 	    if (use_float)
4131 	    {
4132 		if (op == '*')
4133 		    f1 = f1 * f2;
4134 		else if (op == '/')
4135 		{
4136 # ifdef VMS
4137 		    /* VMS crashes on divide by zero, work around it */
4138 		    if (f2 == 0.0)
4139 		    {
4140 			if (f1 == 0)
4141 			    f1 = -1 * __F_FLT_MAX - 1L;   /* similar to NaN */
4142 			else if (f1 < 0)
4143 			    f1 = -1 * __F_FLT_MAX;
4144 			else
4145 			    f1 = __F_FLT_MAX;
4146 		    }
4147 		    else
4148 			f1 = f1 / f2;
4149 # else
4150 		    /* We rely on the floating point library to handle divide
4151 		     * by zero to result in "inf" and not a crash. */
4152 		    f1 = f1 / f2;
4153 # endif
4154 		}
4155 		else
4156 		{
4157 		    emsg(_("E804: Cannot use '%' with Float"));
4158 		    return FAIL;
4159 		}
4160 		rettv->v_type = VAR_FLOAT;
4161 		rettv->vval.v_float = f1;
4162 	    }
4163 	    else
4164 #endif
4165 	    {
4166 		if (op == '*')
4167 		    n1 = n1 * n2;
4168 		else if (op == '/')
4169 		    n1 = num_divide(n1, n2);
4170 		else
4171 		    n1 = num_modulus(n1, n2);
4172 
4173 		rettv->v_type = VAR_NUMBER;
4174 		rettv->vval.v_number = n1;
4175 	    }
4176 	}
4177     }
4178 
4179     return OK;
4180 }
4181 
4182 /*
4183  * Handle sixth level expression:
4184  *  number		number constant
4185  *  0zFFFFFFFF		Blob constant
4186  *  "string"		string constant
4187  *  'string'		literal string constant
4188  *  &option-name	option value
4189  *  @r			register contents
4190  *  identifier		variable value
4191  *  function()		function call
4192  *  $VAR		environment variable
4193  *  (expression)	nested expression
4194  *  [expr, expr]	List
4195  *  {key: val, key: val}  Dictionary
4196  *
4197  *  Also handle:
4198  *  ! in front		logical NOT
4199  *  - in front		unary minus
4200  *  + in front		unary plus (ignored)
4201  *  trailing []		subscript in String or List
4202  *  trailing .name	entry in Dictionary
4203  *
4204  * "arg" must point to the first non-white of the expression.
4205  * "arg" is advanced to the next non-white after the recognized expression.
4206  *
4207  * Return OK or FAIL.
4208  */
4209     static int
4210 eval7(
4211     char_u	**arg,
4212     typval_T	*rettv,
4213     int		evaluate,
4214     int		want_string UNUSED)	/* after "." operator */
4215 {
4216     varnumber_T	n;
4217     int		len;
4218     char_u	*s;
4219     char_u	*start_leader, *end_leader;
4220     int		ret = OK;
4221     char_u	*alias;
4222 
4223     /*
4224      * Initialise variable so that clear_tv() can't mistake this for a
4225      * string and free a string that isn't there.
4226      */
4227     rettv->v_type = VAR_UNKNOWN;
4228 
4229     /*
4230      * Skip '!', '-' and '+' characters.  They are handled later.
4231      */
4232     start_leader = *arg;
4233     while (**arg == '!' || **arg == '-' || **arg == '+')
4234 	*arg = skipwhite(*arg + 1);
4235     end_leader = *arg;
4236 
4237     if (**arg == '.' && (!isdigit(*(*arg + 1))
4238 #ifdef FEAT_FLOAT
4239 	    || current_sctx.sc_version < 2
4240 #endif
4241 	    ))
4242     {
4243 	semsg(_(e_invexpr2), *arg);
4244 	++*arg;
4245 	return FAIL;
4246     }
4247 
4248     switch (**arg)
4249     {
4250     /*
4251      * Number constant.
4252      */
4253     case '0':
4254     case '1':
4255     case '2':
4256     case '3':
4257     case '4':
4258     case '5':
4259     case '6':
4260     case '7':
4261     case '8':
4262     case '9':
4263     case '.':
4264 	{
4265 #ifdef FEAT_FLOAT
4266 		char_u *p;
4267 		int    get_float = FALSE;
4268 
4269 		/* We accept a float when the format matches
4270 		 * "[0-9]\+\.[0-9]\+\([eE][+-]\?[0-9]\+\)\?".  This is very
4271 		 * strict to avoid backwards compatibility problems.
4272 		 * With script version 2 and later the leading digit can be
4273 		 * omitted.
4274 		 * Don't look for a float after the "." operator, so that
4275 		 * ":let vers = 1.2.3" doesn't fail. */
4276 		if (**arg == '.')
4277 		    p = *arg;
4278 		else
4279 		    p = skipdigits(*arg + 1);
4280 		if (!want_string && p[0] == '.' && vim_isdigit(p[1]))
4281 		{
4282 		    get_float = TRUE;
4283 		    p = skipdigits(p + 2);
4284 		    if (*p == 'e' || *p == 'E')
4285 		    {
4286 			++p;
4287 			if (*p == '-' || *p == '+')
4288 			    ++p;
4289 			if (!vim_isdigit(*p))
4290 			    get_float = FALSE;
4291 			else
4292 			    p = skipdigits(p + 1);
4293 		    }
4294 		    if (ASCII_ISALPHA(*p) || *p == '.')
4295 			get_float = FALSE;
4296 		}
4297 		if (get_float)
4298 		{
4299 		    float_T	f;
4300 
4301 		    *arg += string2float(*arg, &f);
4302 		    if (evaluate)
4303 		    {
4304 			rettv->v_type = VAR_FLOAT;
4305 			rettv->vval.v_float = f;
4306 		    }
4307 		}
4308 		else
4309 #endif
4310 		if (**arg == '0' && ((*arg)[1] == 'z' || (*arg)[1] == 'Z'))
4311 		{
4312 		    char_u  *bp;
4313 		    blob_T  *blob = NULL;  // init for gcc
4314 
4315 		    // Blob constant: 0z0123456789abcdef
4316 		    if (evaluate)
4317 			blob = blob_alloc();
4318 		    for (bp = *arg + 2; vim_isxdigit(bp[0]); bp += 2)
4319 		    {
4320 			if (!vim_isxdigit(bp[1]))
4321 			{
4322 			    if (blob != NULL)
4323 			    {
4324 				emsg(_("E973: Blob literal should have an even number of hex characters"));
4325 				ga_clear(&blob->bv_ga);
4326 				VIM_CLEAR(blob);
4327 			    }
4328 			    ret = FAIL;
4329 			    break;
4330 			}
4331 			if (blob != NULL)
4332 			    ga_append(&blob->bv_ga,
4333 					 (hex2nr(*bp) << 4) + hex2nr(*(bp+1)));
4334 			if (bp[2] == '.' && vim_isxdigit(bp[3]))
4335 			    ++bp;
4336 		    }
4337 		    if (blob != NULL)
4338 			rettv_blob_set(rettv, blob);
4339 		    *arg = bp;
4340 		}
4341 		else
4342 		{
4343 		    // decimal, hex or octal number
4344 		    vim_str2nr(*arg, NULL, &len, STR2NR_ALL, &n, NULL, 0);
4345 		    *arg += len;
4346 		    if (evaluate)
4347 		    {
4348 			rettv->v_type = VAR_NUMBER;
4349 			rettv->vval.v_number = n;
4350 		    }
4351 		}
4352 		break;
4353 	}
4354 
4355     /*
4356      * String constant: "string".
4357      */
4358     case '"':	ret = get_string_tv(arg, rettv, evaluate);
4359 		break;
4360 
4361     /*
4362      * Literal string constant: 'str''ing'.
4363      */
4364     case '\'':	ret = get_lit_string_tv(arg, rettv, evaluate);
4365 		break;
4366 
4367     /*
4368      * List: [expr, expr]
4369      */
4370     case '[':	ret = get_list_tv(arg, rettv, evaluate);
4371 		break;
4372 
4373     /*
4374      * Lambda: {arg, arg -> expr}
4375      * Dictionary: {key: val, key: val}
4376      */
4377     case '{':	ret = get_lambda_tv(arg, rettv, evaluate);
4378 		if (ret == NOTDONE)
4379 		    ret = dict_get_tv(arg, rettv, evaluate);
4380 		break;
4381 
4382     /*
4383      * Option value: &name
4384      */
4385     case '&':	ret = get_option_tv(arg, rettv, evaluate);
4386 		break;
4387 
4388     /*
4389      * Environment variable: $VAR.
4390      */
4391     case '$':	ret = get_env_tv(arg, rettv, evaluate);
4392 		break;
4393 
4394     /*
4395      * Register contents: @r.
4396      */
4397     case '@':	++*arg;
4398 		if (evaluate)
4399 		{
4400 		    rettv->v_type = VAR_STRING;
4401 		    rettv->vval.v_string = get_reg_contents(**arg,
4402 							    GREG_EXPR_SRC);
4403 		}
4404 		if (**arg != NUL)
4405 		    ++*arg;
4406 		break;
4407 
4408     /*
4409      * nested expression: (expression).
4410      */
4411     case '(':	*arg = skipwhite(*arg + 1);
4412 		ret = eval1(arg, rettv, evaluate);	/* recursive! */
4413 		if (**arg == ')')
4414 		    ++*arg;
4415 		else if (ret == OK)
4416 		{
4417 		    emsg(_("E110: Missing ')'"));
4418 		    clear_tv(rettv);
4419 		    ret = FAIL;
4420 		}
4421 		break;
4422 
4423     default:	ret = NOTDONE;
4424 		break;
4425     }
4426 
4427     if (ret == NOTDONE)
4428     {
4429 	/*
4430 	 * Must be a variable or function name.
4431 	 * Can also be a curly-braces kind of name: {expr}.
4432 	 */
4433 	s = *arg;
4434 	len = get_name_len(arg, &alias, evaluate, TRUE);
4435 	if (alias != NULL)
4436 	    s = alias;
4437 
4438 	if (len <= 0)
4439 	    ret = FAIL;
4440 	else
4441 	{
4442 	    if (**arg == '(')		/* recursive! */
4443 	    {
4444 		partial_T *partial;
4445 
4446 		if (!evaluate)
4447 		    check_vars(s, len);
4448 
4449 		/* If "s" is the name of a variable of type VAR_FUNC
4450 		 * use its contents. */
4451 		s = deref_func_name(s, &len, &partial, !evaluate);
4452 
4453 		/* Need to make a copy, in case evaluating the arguments makes
4454 		 * the name invalid. */
4455 		s = vim_strsave(s);
4456 		if (s == NULL)
4457 		    ret = FAIL;
4458 		else
4459 		    /* Invoke the function. */
4460 		    ret = get_func_tv(s, len, rettv, arg,
4461 			      curwin->w_cursor.lnum, curwin->w_cursor.lnum,
4462 			      &len, evaluate, partial, NULL);
4463 		vim_free(s);
4464 
4465 		/* If evaluate is FALSE rettv->v_type was not set in
4466 		 * get_func_tv, but it's needed in handle_subscript() to parse
4467 		 * what follows. So set it here. */
4468 		if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
4469 		{
4470 		    rettv->vval.v_string = NULL;
4471 		    rettv->v_type = VAR_FUNC;
4472 		}
4473 
4474 		/* Stop the expression evaluation when immediately
4475 		 * aborting on error, or when an interrupt occurred or
4476 		 * an exception was thrown but not caught. */
4477 		if (aborting())
4478 		{
4479 		    if (ret == OK)
4480 			clear_tv(rettv);
4481 		    ret = FAIL;
4482 		}
4483 	    }
4484 	    else if (evaluate)
4485 		ret = get_var_tv(s, len, rettv, NULL, TRUE, FALSE);
4486 	    else
4487 	    {
4488 		check_vars(s, len);
4489 		ret = OK;
4490 	    }
4491 	}
4492 	vim_free(alias);
4493     }
4494 
4495     *arg = skipwhite(*arg);
4496 
4497     /* Handle following '[', '(' and '.' for expr[expr], expr.name,
4498      * expr(expr). */
4499     if (ret == OK)
4500 	ret = handle_subscript(arg, rettv, evaluate, TRUE);
4501 
4502     /*
4503      * Apply logical NOT and unary '-', from right to left, ignore '+'.
4504      */
4505     if (ret == OK && evaluate && end_leader > start_leader)
4506     {
4507 	int	    error = FALSE;
4508 	varnumber_T val = 0;
4509 #ifdef FEAT_FLOAT
4510 	float_T	    f = 0.0;
4511 
4512 	if (rettv->v_type == VAR_FLOAT)
4513 	    f = rettv->vval.v_float;
4514 	else
4515 #endif
4516 	    val = tv_get_number_chk(rettv, &error);
4517 	if (error)
4518 	{
4519 	    clear_tv(rettv);
4520 	    ret = FAIL;
4521 	}
4522 	else
4523 	{
4524 	    while (end_leader > start_leader)
4525 	    {
4526 		--end_leader;
4527 		if (*end_leader == '!')
4528 		{
4529 #ifdef FEAT_FLOAT
4530 		    if (rettv->v_type == VAR_FLOAT)
4531 			f = !f;
4532 		    else
4533 #endif
4534 			val = !val;
4535 		}
4536 		else if (*end_leader == '-')
4537 		{
4538 #ifdef FEAT_FLOAT
4539 		    if (rettv->v_type == VAR_FLOAT)
4540 			f = -f;
4541 		    else
4542 #endif
4543 			val = -val;
4544 		}
4545 	    }
4546 #ifdef FEAT_FLOAT
4547 	    if (rettv->v_type == VAR_FLOAT)
4548 	    {
4549 		clear_tv(rettv);
4550 		rettv->vval.v_float = f;
4551 	    }
4552 	    else
4553 #endif
4554 	    {
4555 		clear_tv(rettv);
4556 		rettv->v_type = VAR_NUMBER;
4557 		rettv->vval.v_number = val;
4558 	    }
4559 	}
4560     }
4561 
4562     return ret;
4563 }
4564 
4565 /*
4566  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
4567  * "*arg" points to the '[' or '.'.
4568  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
4569  */
4570     static int
4571 eval_index(
4572     char_u	**arg,
4573     typval_T	*rettv,
4574     int		evaluate,
4575     int		verbose)	/* give error messages */
4576 {
4577     int		empty1 = FALSE, empty2 = FALSE;
4578     typval_T	var1, var2;
4579     long	i;
4580     long	n1, n2 = 0;
4581     long	len = -1;
4582     int		range = FALSE;
4583     char_u	*s;
4584     char_u	*key = NULL;
4585 
4586     switch (rettv->v_type)
4587     {
4588 	case VAR_FUNC:
4589 	case VAR_PARTIAL:
4590 	    if (verbose)
4591 		emsg(_("E695: Cannot index a Funcref"));
4592 	    return FAIL;
4593 	case VAR_FLOAT:
4594 #ifdef FEAT_FLOAT
4595 	    if (verbose)
4596 		emsg(_(e_float_as_string));
4597 	    return FAIL;
4598 #endif
4599 	case VAR_SPECIAL:
4600 	case VAR_JOB:
4601 	case VAR_CHANNEL:
4602 	    if (verbose)
4603 		emsg(_("E909: Cannot index a special variable"));
4604 	    return FAIL;
4605 	case VAR_UNKNOWN:
4606 	    if (evaluate)
4607 		return FAIL;
4608 	    /* FALLTHROUGH */
4609 
4610 	case VAR_STRING:
4611 	case VAR_NUMBER:
4612 	case VAR_LIST:
4613 	case VAR_DICT:
4614 	case VAR_BLOB:
4615 	    break;
4616     }
4617 
4618     init_tv(&var1);
4619     init_tv(&var2);
4620     if (**arg == '.')
4621     {
4622 	/*
4623 	 * dict.name
4624 	 */
4625 	key = *arg + 1;
4626 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
4627 	    ;
4628 	if (len == 0)
4629 	    return FAIL;
4630 	*arg = skipwhite(key + len);
4631     }
4632     else
4633     {
4634 	/*
4635 	 * something[idx]
4636 	 *
4637 	 * Get the (first) variable from inside the [].
4638 	 */
4639 	*arg = skipwhite(*arg + 1);
4640 	if (**arg == ':')
4641 	    empty1 = TRUE;
4642 	else if (eval1(arg, &var1, evaluate) == FAIL)	/* recursive! */
4643 	    return FAIL;
4644 	else if (evaluate && tv_get_string_chk(&var1) == NULL)
4645 	{
4646 	    /* not a number or string */
4647 	    clear_tv(&var1);
4648 	    return FAIL;
4649 	}
4650 
4651 	/*
4652 	 * Get the second variable from inside the [:].
4653 	 */
4654 	if (**arg == ':')
4655 	{
4656 	    range = TRUE;
4657 	    *arg = skipwhite(*arg + 1);
4658 	    if (**arg == ']')
4659 		empty2 = TRUE;
4660 	    else if (eval1(arg, &var2, evaluate) == FAIL)	/* recursive! */
4661 	    {
4662 		if (!empty1)
4663 		    clear_tv(&var1);
4664 		return FAIL;
4665 	    }
4666 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
4667 	    {
4668 		/* not a number or string */
4669 		if (!empty1)
4670 		    clear_tv(&var1);
4671 		clear_tv(&var2);
4672 		return FAIL;
4673 	    }
4674 	}
4675 
4676 	/* Check for the ']'. */
4677 	if (**arg != ']')
4678 	{
4679 	    if (verbose)
4680 		emsg(_(e_missbrac));
4681 	    clear_tv(&var1);
4682 	    if (range)
4683 		clear_tv(&var2);
4684 	    return FAIL;
4685 	}
4686 	*arg = skipwhite(*arg + 1);	/* skip the ']' */
4687     }
4688 
4689     if (evaluate)
4690     {
4691 	n1 = 0;
4692 	if (!empty1 && rettv->v_type != VAR_DICT)
4693 	{
4694 	    n1 = tv_get_number(&var1);
4695 	    clear_tv(&var1);
4696 	}
4697 	if (range)
4698 	{
4699 	    if (empty2)
4700 		n2 = -1;
4701 	    else
4702 	    {
4703 		n2 = tv_get_number(&var2);
4704 		clear_tv(&var2);
4705 	    }
4706 	}
4707 
4708 	switch (rettv->v_type)
4709 	{
4710 	    case VAR_UNKNOWN:
4711 	    case VAR_FUNC:
4712 	    case VAR_PARTIAL:
4713 	    case VAR_FLOAT:
4714 	    case VAR_SPECIAL:
4715 	    case VAR_JOB:
4716 	    case VAR_CHANNEL:
4717 		break; /* not evaluating, skipping over subscript */
4718 
4719 	    case VAR_NUMBER:
4720 	    case VAR_STRING:
4721 		s = tv_get_string(rettv);
4722 		len = (long)STRLEN(s);
4723 		if (range)
4724 		{
4725 		    /* The resulting variable is a substring.  If the indexes
4726 		     * are out of range the result is empty. */
4727 		    if (n1 < 0)
4728 		    {
4729 			n1 = len + n1;
4730 			if (n1 < 0)
4731 			    n1 = 0;
4732 		    }
4733 		    if (n2 < 0)
4734 			n2 = len + n2;
4735 		    else if (n2 >= len)
4736 			n2 = len;
4737 		    if (n1 >= len || n2 < 0 || n1 > n2)
4738 			s = NULL;
4739 		    else
4740 			s = vim_strnsave(s + n1, (int)(n2 - n1 + 1));
4741 		}
4742 		else
4743 		{
4744 		    /* The resulting variable is a string of a single
4745 		     * character.  If the index is too big or negative the
4746 		     * result is empty. */
4747 		    if (n1 >= len || n1 < 0)
4748 			s = NULL;
4749 		    else
4750 			s = vim_strnsave(s + n1, 1);
4751 		}
4752 		clear_tv(rettv);
4753 		rettv->v_type = VAR_STRING;
4754 		rettv->vval.v_string = s;
4755 		break;
4756 
4757 	    case VAR_BLOB:
4758 		len = blob_len(rettv->vval.v_blob);
4759 		if (range)
4760 		{
4761 		    // The resulting variable is a sub-blob.  If the indexes
4762 		    // are out of range the result is empty.
4763 		    if (n1 < 0)
4764 		    {
4765 			n1 = len + n1;
4766 			if (n1 < 0)
4767 			    n1 = 0;
4768 		    }
4769 		    if (n2 < 0)
4770 			n2 = len + n2;
4771 		    else if (n2 >= len)
4772 			n2 = len - 1;
4773 		    if (n1 >= len || n2 < 0 || n1 > n2)
4774 		    {
4775 			clear_tv(rettv);
4776 			rettv->v_type = VAR_BLOB;
4777 			rettv->vval.v_blob = NULL;
4778 		    }
4779 		    else
4780 		    {
4781 			blob_T  *blob = blob_alloc();
4782 
4783 			if (blob != NULL)
4784 			{
4785 			    if (ga_grow(&blob->bv_ga, n2 - n1 + 1) == FAIL)
4786 			    {
4787 				blob_free(blob);
4788 				return FAIL;
4789 			    }
4790 			    blob->bv_ga.ga_len = n2 - n1 + 1;
4791 			    for (i = n1; i <= n2; i++)
4792 				blob_set(blob, i - n1,
4793 					      blob_get(rettv->vval.v_blob, i));
4794 
4795 			    clear_tv(rettv);
4796 			    rettv_blob_set(rettv, blob);
4797 			}
4798 		    }
4799 		}
4800 		else
4801 		{
4802 		    // The resulting variable is a byte value.
4803 		    // If the index is too big or negative that is an error.
4804 		    if (n1 < 0)
4805 			n1 = len + n1;
4806 		    if (n1 < len && n1 >= 0)
4807 		    {
4808 			int v = blob_get(rettv->vval.v_blob, n1);
4809 
4810 			clear_tv(rettv);
4811 			rettv->v_type = VAR_NUMBER;
4812 			rettv->vval.v_number = v;
4813 		    }
4814 		    else
4815 			semsg(_(e_blobidx), n1);
4816 		}
4817 		break;
4818 
4819 	    case VAR_LIST:
4820 		len = list_len(rettv->vval.v_list);
4821 		if (n1 < 0)
4822 		    n1 = len + n1;
4823 		if (!empty1 && (n1 < 0 || n1 >= len))
4824 		{
4825 		    /* For a range we allow invalid values and return an empty
4826 		     * list.  A list index out of range is an error. */
4827 		    if (!range)
4828 		    {
4829 			if (verbose)
4830 			    semsg(_(e_listidx), n1);
4831 			return FAIL;
4832 		    }
4833 		    n1 = len;
4834 		}
4835 		if (range)
4836 		{
4837 		    list_T	*l;
4838 		    listitem_T	*item;
4839 
4840 		    if (n2 < 0)
4841 			n2 = len + n2;
4842 		    else if (n2 >= len)
4843 			n2 = len - 1;
4844 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
4845 			n2 = -1;
4846 		    l = list_alloc();
4847 		    if (l == NULL)
4848 			return FAIL;
4849 		    for (item = list_find(rettv->vval.v_list, n1);
4850 							       n1 <= n2; ++n1)
4851 		    {
4852 			if (list_append_tv(l, &item->li_tv) == FAIL)
4853 			{
4854 			    list_free(l);
4855 			    return FAIL;
4856 			}
4857 			item = item->li_next;
4858 		    }
4859 		    clear_tv(rettv);
4860 		    rettv_list_set(rettv, l);
4861 		}
4862 		else
4863 		{
4864 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
4865 		    clear_tv(rettv);
4866 		    *rettv = var1;
4867 		}
4868 		break;
4869 
4870 	    case VAR_DICT:
4871 		if (range)
4872 		{
4873 		    if (verbose)
4874 			emsg(_(e_dictrange));
4875 		    if (len == -1)
4876 			clear_tv(&var1);
4877 		    return FAIL;
4878 		}
4879 		{
4880 		    dictitem_T	*item;
4881 
4882 		    if (len == -1)
4883 		    {
4884 			key = tv_get_string_chk(&var1);
4885 			if (key == NULL)
4886 			{
4887 			    clear_tv(&var1);
4888 			    return FAIL;
4889 			}
4890 		    }
4891 
4892 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
4893 
4894 		    if (item == NULL && verbose)
4895 			semsg(_(e_dictkey), key);
4896 		    if (len == -1)
4897 			clear_tv(&var1);
4898 		    if (item == NULL)
4899 			return FAIL;
4900 
4901 		    copy_tv(&item->di_tv, &var1);
4902 		    clear_tv(rettv);
4903 		    *rettv = var1;
4904 		}
4905 		break;
4906 	}
4907     }
4908 
4909     return OK;
4910 }
4911 
4912 /*
4913  * Get an option value.
4914  * "arg" points to the '&' or '+' before the option name.
4915  * "arg" is advanced to character after the option name.
4916  * Return OK or FAIL.
4917  */
4918     int
4919 get_option_tv(
4920     char_u	**arg,
4921     typval_T	*rettv,	/* when NULL, only check if option exists */
4922     int		evaluate)
4923 {
4924     char_u	*option_end;
4925     long	numval;
4926     char_u	*stringval;
4927     int		opt_type;
4928     int		c;
4929     int		working = (**arg == '+');    /* has("+option") */
4930     int		ret = OK;
4931     int		opt_flags;
4932 
4933     /*
4934      * Isolate the option name and find its value.
4935      */
4936     option_end = find_option_end(arg, &opt_flags);
4937     if (option_end == NULL)
4938     {
4939 	if (rettv != NULL)
4940 	    semsg(_("E112: Option name missing: %s"), *arg);
4941 	return FAIL;
4942     }
4943 
4944     if (!evaluate)
4945     {
4946 	*arg = option_end;
4947 	return OK;
4948     }
4949 
4950     c = *option_end;
4951     *option_end = NUL;
4952     opt_type = get_option_value(*arg, &numval,
4953 			       rettv == NULL ? NULL : &stringval, opt_flags);
4954 
4955     if (opt_type == -3)			/* invalid name */
4956     {
4957 	if (rettv != NULL)
4958 	    semsg(_("E113: Unknown option: %s"), *arg);
4959 	ret = FAIL;
4960     }
4961     else if (rettv != NULL)
4962     {
4963 	if (opt_type == -2)		/* hidden string option */
4964 	{
4965 	    rettv->v_type = VAR_STRING;
4966 	    rettv->vval.v_string = NULL;
4967 	}
4968 	else if (opt_type == -1)	/* hidden number option */
4969 	{
4970 	    rettv->v_type = VAR_NUMBER;
4971 	    rettv->vval.v_number = 0;
4972 	}
4973 	else if (opt_type == 1)		/* number option */
4974 	{
4975 	    rettv->v_type = VAR_NUMBER;
4976 	    rettv->vval.v_number = numval;
4977 	}
4978 	else				/* string option */
4979 	{
4980 	    rettv->v_type = VAR_STRING;
4981 	    rettv->vval.v_string = stringval;
4982 	}
4983     }
4984     else if (working && (opt_type == -2 || opt_type == -1))
4985 	ret = FAIL;
4986 
4987     *option_end = c;		    /* put back for error messages */
4988     *arg = option_end;
4989 
4990     return ret;
4991 }
4992 
4993 /*
4994  * Allocate a variable for a string constant.
4995  * Return OK or FAIL.
4996  */
4997     static int
4998 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
4999 {
5000     char_u	*p;
5001     char_u	*name;
5002     int		extra = 0;
5003 
5004     /*
5005      * Find the end of the string, skipping backslashed characters.
5006      */
5007     for (p = *arg + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5008     {
5009 	if (*p == '\\' && p[1] != NUL)
5010 	{
5011 	    ++p;
5012 	    /* A "\<x>" form occupies at least 4 characters, and produces up
5013 	     * to 6 characters: reserve space for 2 extra */
5014 	    if (*p == '<')
5015 		extra += 2;
5016 	}
5017     }
5018 
5019     if (*p != '"')
5020     {
5021 	semsg(_("E114: Missing quote: %s"), *arg);
5022 	return FAIL;
5023     }
5024 
5025     /* If only parsing, set *arg and return here */
5026     if (!evaluate)
5027     {
5028 	*arg = p + 1;
5029 	return OK;
5030     }
5031 
5032     /*
5033      * Copy the string into allocated memory, handling backslashed
5034      * characters.
5035      */
5036     name = alloc((unsigned)(p - *arg + extra));
5037     if (name == NULL)
5038 	return FAIL;
5039     rettv->v_type = VAR_STRING;
5040     rettv->vval.v_string = name;
5041 
5042     for (p = *arg + 1; *p != NUL && *p != '"'; )
5043     {
5044 	if (*p == '\\')
5045 	{
5046 	    switch (*++p)
5047 	    {
5048 		case 'b': *name++ = BS; ++p; break;
5049 		case 'e': *name++ = ESC; ++p; break;
5050 		case 'f': *name++ = FF; ++p; break;
5051 		case 'n': *name++ = NL; ++p; break;
5052 		case 'r': *name++ = CAR; ++p; break;
5053 		case 't': *name++ = TAB; ++p; break;
5054 
5055 		case 'X': /* hex: "\x1", "\x12" */
5056 		case 'x':
5057 		case 'u': /* Unicode: "\u0023" */
5058 		case 'U':
5059 			  if (vim_isxdigit(p[1]))
5060 			  {
5061 			      int	n, nr;
5062 			      int	c = toupper(*p);
5063 
5064 			      if (c == 'X')
5065 				  n = 2;
5066 			      else if (*p == 'u')
5067 				  n = 4;
5068 			      else
5069 				  n = 8;
5070 			      nr = 0;
5071 			      while (--n >= 0 && vim_isxdigit(p[1]))
5072 			      {
5073 				  ++p;
5074 				  nr = (nr << 4) + hex2nr(*p);
5075 			      }
5076 			      ++p;
5077 			      /* For "\u" store the number according to
5078 			       * 'encoding'. */
5079 			      if (c != 'X')
5080 				  name += (*mb_char2bytes)(nr, name);
5081 			      else
5082 				  *name++ = nr;
5083 			  }
5084 			  break;
5085 
5086 			  /* octal: "\1", "\12", "\123" */
5087 		case '0':
5088 		case '1':
5089 		case '2':
5090 		case '3':
5091 		case '4':
5092 		case '5':
5093 		case '6':
5094 		case '7': *name = *p++ - '0';
5095 			  if (*p >= '0' && *p <= '7')
5096 			  {
5097 			      *name = (*name << 3) + *p++ - '0';
5098 			      if (*p >= '0' && *p <= '7')
5099 				  *name = (*name << 3) + *p++ - '0';
5100 			  }
5101 			  ++name;
5102 			  break;
5103 
5104 			    /* Special key, e.g.: "\<C-W>" */
5105 		case '<': extra = trans_special(&p, name, TRUE, TRUE);
5106 			  if (extra != 0)
5107 			  {
5108 			      name += extra;
5109 			      break;
5110 			  }
5111 			  /* FALLTHROUGH */
5112 
5113 		default:  MB_COPY_CHAR(p, name);
5114 			  break;
5115 	    }
5116 	}
5117 	else
5118 	    MB_COPY_CHAR(p, name);
5119 
5120     }
5121     *name = NUL;
5122     if (*p != NUL) /* just in case */
5123 	++p;
5124     *arg = p;
5125 
5126     return OK;
5127 }
5128 
5129 /*
5130  * Allocate a variable for a 'str''ing' constant.
5131  * Return OK or FAIL.
5132  */
5133     static int
5134 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
5135 {
5136     char_u	*p;
5137     char_u	*str;
5138     int		reduce = 0;
5139 
5140     /*
5141      * Find the end of the string, skipping ''.
5142      */
5143     for (p = *arg + 1; *p != NUL; MB_PTR_ADV(p))
5144     {
5145 	if (*p == '\'')
5146 	{
5147 	    if (p[1] != '\'')
5148 		break;
5149 	    ++reduce;
5150 	    ++p;
5151 	}
5152     }
5153 
5154     if (*p != '\'')
5155     {
5156 	semsg(_("E115: Missing quote: %s"), *arg);
5157 	return FAIL;
5158     }
5159 
5160     /* If only parsing return after setting "*arg" */
5161     if (!evaluate)
5162     {
5163 	*arg = p + 1;
5164 	return OK;
5165     }
5166 
5167     /*
5168      * Copy the string into allocated memory, handling '' to ' reduction.
5169      */
5170     str = alloc((unsigned)((p - *arg) - reduce));
5171     if (str == NULL)
5172 	return FAIL;
5173     rettv->v_type = VAR_STRING;
5174     rettv->vval.v_string = str;
5175 
5176     for (p = *arg + 1; *p != NUL; )
5177     {
5178 	if (*p == '\'')
5179 	{
5180 	    if (p[1] != '\'')
5181 		break;
5182 	    ++p;
5183 	}
5184 	MB_COPY_CHAR(p, str);
5185     }
5186     *str = NUL;
5187     *arg = p + 1;
5188 
5189     return OK;
5190 }
5191 
5192 /*
5193  * Return the function name of the partial.
5194  */
5195     char_u *
5196 partial_name(partial_T *pt)
5197 {
5198     if (pt->pt_name != NULL)
5199 	return pt->pt_name;
5200     return pt->pt_func->uf_name;
5201 }
5202 
5203     static void
5204 partial_free(partial_T *pt)
5205 {
5206     int i;
5207 
5208     for (i = 0; i < pt->pt_argc; ++i)
5209 	clear_tv(&pt->pt_argv[i]);
5210     vim_free(pt->pt_argv);
5211     dict_unref(pt->pt_dict);
5212     if (pt->pt_name != NULL)
5213     {
5214 	func_unref(pt->pt_name);
5215 	vim_free(pt->pt_name);
5216     }
5217     else
5218 	func_ptr_unref(pt->pt_func);
5219     vim_free(pt);
5220 }
5221 
5222 /*
5223  * Unreference a closure: decrement the reference count and free it when it
5224  * becomes zero.
5225  */
5226     void
5227 partial_unref(partial_T *pt)
5228 {
5229     if (pt != NULL && --pt->pt_refcount <= 0)
5230 	partial_free(pt);
5231 }
5232 
5233 static int tv_equal_recurse_limit;
5234 
5235     static int
5236 func_equal(
5237     typval_T *tv1,
5238     typval_T *tv2,
5239     int	     ic)	    /* ignore case */
5240 {
5241     char_u	*s1, *s2;
5242     dict_T	*d1, *d2;
5243     int		a1, a2;
5244     int		i;
5245 
5246     /* empty and NULL function name considered the same */
5247     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
5248 					   : partial_name(tv1->vval.v_partial);
5249     if (s1 != NULL && *s1 == NUL)
5250 	s1 = NULL;
5251     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
5252 					   : partial_name(tv2->vval.v_partial);
5253     if (s2 != NULL && *s2 == NUL)
5254 	s2 = NULL;
5255     if (s1 == NULL || s2 == NULL)
5256     {
5257 	if (s1 != s2)
5258 	    return FALSE;
5259     }
5260     else if (STRCMP(s1, s2) != 0)
5261 	return FALSE;
5262 
5263     /* empty dict and NULL dict is different */
5264     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
5265     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
5266     if (d1 == NULL || d2 == NULL)
5267     {
5268 	if (d1 != d2)
5269 	    return FALSE;
5270     }
5271     else if (!dict_equal(d1, d2, ic, TRUE))
5272 	return FALSE;
5273 
5274     /* empty list and no list considered the same */
5275     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
5276     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
5277     if (a1 != a2)
5278 	return FALSE;
5279     for (i = 0; i < a1; ++i)
5280 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
5281 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
5282 	    return FALSE;
5283 
5284     return TRUE;
5285 }
5286 
5287 /*
5288  * Return TRUE if "tv1" and "tv2" have the same value.
5289  * Compares the items just like "==" would compare them, but strings and
5290  * numbers are different.  Floats and numbers are also different.
5291  */
5292     int
5293 tv_equal(
5294     typval_T *tv1,
5295     typval_T *tv2,
5296     int	     ic,	    /* ignore case */
5297     int	     recursive)	    /* TRUE when used recursively */
5298 {
5299     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
5300     char_u	*s1, *s2;
5301     static int  recursive_cnt = 0;	    /* catch recursive loops */
5302     int		r;
5303 
5304     /* Catch lists and dicts that have an endless loop by limiting
5305      * recursiveness to a limit.  We guess they are equal then.
5306      * A fixed limit has the problem of still taking an awful long time.
5307      * Reduce the limit every time running into it. That should work fine for
5308      * deeply linked structures that are not recursively linked and catch
5309      * recursiveness quickly. */
5310     if (!recursive)
5311 	tv_equal_recurse_limit = 1000;
5312     if (recursive_cnt >= tv_equal_recurse_limit)
5313     {
5314 	--tv_equal_recurse_limit;
5315 	return TRUE;
5316     }
5317 
5318     /* For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
5319      * arguments. */
5320     if ((tv1->v_type == VAR_FUNC
5321 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
5322 	    && (tv2->v_type == VAR_FUNC
5323 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
5324     {
5325 	++recursive_cnt;
5326 	r = func_equal(tv1, tv2, ic);
5327 	--recursive_cnt;
5328 	return r;
5329     }
5330 
5331     if (tv1->v_type != tv2->v_type)
5332 	return FALSE;
5333 
5334     switch (tv1->v_type)
5335     {
5336 	case VAR_LIST:
5337 	    ++recursive_cnt;
5338 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
5339 	    --recursive_cnt;
5340 	    return r;
5341 
5342 	case VAR_DICT:
5343 	    ++recursive_cnt;
5344 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
5345 	    --recursive_cnt;
5346 	    return r;
5347 
5348 	case VAR_BLOB:
5349 	    return blob_equal(tv1->vval.v_blob, tv2->vval.v_blob);
5350 
5351 	case VAR_NUMBER:
5352 	    return tv1->vval.v_number == tv2->vval.v_number;
5353 
5354 	case VAR_STRING:
5355 	    s1 = tv_get_string_buf(tv1, buf1);
5356 	    s2 = tv_get_string_buf(tv2, buf2);
5357 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
5358 
5359 	case VAR_SPECIAL:
5360 	    return tv1->vval.v_number == tv2->vval.v_number;
5361 
5362 	case VAR_FLOAT:
5363 #ifdef FEAT_FLOAT
5364 	    return tv1->vval.v_float == tv2->vval.v_float;
5365 #endif
5366 	case VAR_JOB:
5367 #ifdef FEAT_JOB_CHANNEL
5368 	    return tv1->vval.v_job == tv2->vval.v_job;
5369 #endif
5370 	case VAR_CHANNEL:
5371 #ifdef FEAT_JOB_CHANNEL
5372 	    return tv1->vval.v_channel == tv2->vval.v_channel;
5373 #endif
5374 	case VAR_FUNC:
5375 	case VAR_PARTIAL:
5376 	case VAR_UNKNOWN:
5377 	    break;
5378     }
5379 
5380     /* VAR_UNKNOWN can be the result of a invalid expression, let's say it
5381      * does not equal anything, not even itself. */
5382     return FALSE;
5383 }
5384 
5385 /*
5386  * Return the next (unique) copy ID.
5387  * Used for serializing nested structures.
5388  */
5389     int
5390 get_copyID(void)
5391 {
5392     current_copyID += COPYID_INC;
5393     return current_copyID;
5394 }
5395 
5396 /*
5397  * Garbage collection for lists and dictionaries.
5398  *
5399  * We use reference counts to be able to free most items right away when they
5400  * are no longer used.  But for composite items it's possible that it becomes
5401  * unused while the reference count is > 0: When there is a recursive
5402  * reference.  Example:
5403  *	:let l = [1, 2, 3]
5404  *	:let d = {9: l}
5405  *	:let l[1] = d
5406  *
5407  * Since this is quite unusual we handle this with garbage collection: every
5408  * once in a while find out which lists and dicts are not referenced from any
5409  * variable.
5410  *
5411  * Here is a good reference text about garbage collection (refers to Python
5412  * but it applies to all reference-counting mechanisms):
5413  *	http://python.ca/nas/python/gc/
5414  */
5415 
5416 /*
5417  * Do garbage collection for lists and dicts.
5418  * When "testing" is TRUE this is called from test_garbagecollect_now().
5419  * Return TRUE if some memory was freed.
5420  */
5421     int
5422 garbage_collect(int testing)
5423 {
5424     int		copyID;
5425     int		abort = FALSE;
5426     buf_T	*buf;
5427     win_T	*wp;
5428     int		i;
5429     int		did_free = FALSE;
5430     tabpage_T	*tp;
5431 
5432     if (!testing)
5433     {
5434 	/* Only do this once. */
5435 	want_garbage_collect = FALSE;
5436 	may_garbage_collect = FALSE;
5437 	garbage_collect_at_exit = FALSE;
5438     }
5439 
5440     /* We advance by two because we add one for items referenced through
5441      * previous_funccal. */
5442     copyID = get_copyID();
5443 
5444     /*
5445      * 1. Go through all accessible variables and mark all lists and dicts
5446      *    with copyID.
5447      */
5448 
5449     /* Don't free variables in the previous_funccal list unless they are only
5450      * referenced through previous_funccal.  This must be first, because if
5451      * the item is referenced elsewhere the funccal must not be freed. */
5452     abort = abort || set_ref_in_previous_funccal(copyID);
5453 
5454     /* script-local variables */
5455     for (i = 1; i <= ga_scripts.ga_len; ++i)
5456 	abort = abort || set_ref_in_ht(&SCRIPT_VARS(i), copyID, NULL);
5457 
5458     /* buffer-local variables */
5459     FOR_ALL_BUFFERS(buf)
5460 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
5461 								  NULL, NULL);
5462 
5463     /* window-local variables */
5464     FOR_ALL_TAB_WINDOWS(tp, wp)
5465 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
5466 								  NULL, NULL);
5467     if (aucmd_win != NULL)
5468 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
5469 								  NULL, NULL);
5470 
5471     /* tabpage-local variables */
5472     FOR_ALL_TABPAGES(tp)
5473 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
5474 								  NULL, NULL);
5475     /* global variables */
5476     abort = abort || set_ref_in_ht(&globvarht, copyID, NULL);
5477 
5478     /* function-local variables */
5479     abort = abort || set_ref_in_call_stack(copyID);
5480 
5481     /* named functions (matters for closures) */
5482     abort = abort || set_ref_in_functions(copyID);
5483 
5484     /* function call arguments, if v:testing is set. */
5485     abort = abort || set_ref_in_func_args(copyID);
5486 
5487     /* v: vars */
5488     abort = abort || set_ref_in_ht(&vimvarht, copyID, NULL);
5489 
5490 #ifdef FEAT_LUA
5491     abort = abort || set_ref_in_lua(copyID);
5492 #endif
5493 
5494 #ifdef FEAT_PYTHON
5495     abort = abort || set_ref_in_python(copyID);
5496 #endif
5497 
5498 #ifdef FEAT_PYTHON3
5499     abort = abort || set_ref_in_python3(copyID);
5500 #endif
5501 
5502 #ifdef FEAT_JOB_CHANNEL
5503     abort = abort || set_ref_in_channel(copyID);
5504     abort = abort || set_ref_in_job(copyID);
5505 #endif
5506 #ifdef FEAT_NETBEANS_INTG
5507     abort = abort || set_ref_in_nb_channel(copyID);
5508 #endif
5509 
5510 #ifdef FEAT_TIMERS
5511     abort = abort || set_ref_in_timer(copyID);
5512 #endif
5513 
5514 #ifdef FEAT_QUICKFIX
5515     abort = abort || set_ref_in_quickfix(copyID);
5516 #endif
5517 
5518 #ifdef FEAT_TERMINAL
5519     abort = abort || set_ref_in_term(copyID);
5520 #endif
5521 
5522     if (!abort)
5523     {
5524 	/*
5525 	 * 2. Free lists and dictionaries that are not referenced.
5526 	 */
5527 	did_free = free_unref_items(copyID);
5528 
5529 	/*
5530 	 * 3. Check if any funccal can be freed now.
5531 	 *    This may call us back recursively.
5532 	 */
5533 	free_unref_funccal(copyID, testing);
5534     }
5535     else if (p_verbose > 0)
5536     {
5537 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
5538     }
5539 
5540     return did_free;
5541 }
5542 
5543 /*
5544  * Free lists, dictionaries, channels and jobs that are no longer referenced.
5545  */
5546     static int
5547 free_unref_items(int copyID)
5548 {
5549     int		did_free = FALSE;
5550 
5551     /* Let all "free" functions know that we are here.  This means no
5552      * dictionaries, lists, channels or jobs are to be freed, because we will
5553      * do that here. */
5554     in_free_unref_items = TRUE;
5555 
5556     /*
5557      * PASS 1: free the contents of the items.  We don't free the items
5558      * themselves yet, so that it is possible to decrement refcount counters
5559      */
5560 
5561     /* Go through the list of dicts and free items without the copyID. */
5562     did_free |= dict_free_nonref(copyID);
5563 
5564     /* Go through the list of lists and free items without the copyID. */
5565     did_free |= list_free_nonref(copyID);
5566 
5567 #ifdef FEAT_JOB_CHANNEL
5568     /* Go through the list of jobs and free items without the copyID. This
5569      * must happen before doing channels, because jobs refer to channels, but
5570      * the reference from the channel to the job isn't tracked. */
5571     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
5572 
5573     /* Go through the list of channels and free items without the copyID.  */
5574     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
5575 #endif
5576 
5577     /*
5578      * PASS 2: free the items themselves.
5579      */
5580     dict_free_items(copyID);
5581     list_free_items(copyID);
5582 
5583 #ifdef FEAT_JOB_CHANNEL
5584     /* Go through the list of jobs and free items without the copyID. This
5585      * must happen before doing channels, because jobs refer to channels, but
5586      * the reference from the channel to the job isn't tracked. */
5587     free_unused_jobs(copyID, COPYID_MASK);
5588 
5589     /* Go through the list of channels and free items without the copyID.  */
5590     free_unused_channels(copyID, COPYID_MASK);
5591 #endif
5592 
5593     in_free_unref_items = FALSE;
5594 
5595     return did_free;
5596 }
5597 
5598 /*
5599  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
5600  * "list_stack" is used to add lists to be marked.  Can be NULL.
5601  *
5602  * Returns TRUE if setting references failed somehow.
5603  */
5604     int
5605 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
5606 {
5607     int		todo;
5608     int		abort = FALSE;
5609     hashitem_T	*hi;
5610     hashtab_T	*cur_ht;
5611     ht_stack_T	*ht_stack = NULL;
5612     ht_stack_T	*tempitem;
5613 
5614     cur_ht = ht;
5615     for (;;)
5616     {
5617 	if (!abort)
5618 	{
5619 	    /* Mark each item in the hashtab.  If the item contains a hashtab
5620 	     * it is added to ht_stack, if it contains a list it is added to
5621 	     * list_stack. */
5622 	    todo = (int)cur_ht->ht_used;
5623 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
5624 		if (!HASHITEM_EMPTY(hi))
5625 		{
5626 		    --todo;
5627 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
5628 						       &ht_stack, list_stack);
5629 		}
5630 	}
5631 
5632 	if (ht_stack == NULL)
5633 	    break;
5634 
5635 	/* take an item from the stack */
5636 	cur_ht = ht_stack->ht;
5637 	tempitem = ht_stack;
5638 	ht_stack = ht_stack->prev;
5639 	free(tempitem);
5640     }
5641 
5642     return abort;
5643 }
5644 
5645 /*
5646  * Mark all lists and dicts referenced through list "l" with "copyID".
5647  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5648  *
5649  * Returns TRUE if setting references failed somehow.
5650  */
5651     int
5652 set_ref_in_list(list_T *l, int copyID, ht_stack_T **ht_stack)
5653 {
5654     listitem_T	 *li;
5655     int		 abort = FALSE;
5656     list_T	 *cur_l;
5657     list_stack_T *list_stack = NULL;
5658     list_stack_T *tempitem;
5659 
5660     cur_l = l;
5661     for (;;)
5662     {
5663 	if (!abort)
5664 	    /* Mark each item in the list.  If the item contains a hashtab
5665 	     * it is added to ht_stack, if it contains a list it is added to
5666 	     * list_stack. */
5667 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
5668 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
5669 						       ht_stack, &list_stack);
5670 	if (list_stack == NULL)
5671 	    break;
5672 
5673 	/* take an item from the stack */
5674 	cur_l = list_stack->list;
5675 	tempitem = list_stack;
5676 	list_stack = list_stack->prev;
5677 	free(tempitem);
5678     }
5679 
5680     return abort;
5681 }
5682 
5683 /*
5684  * Mark all lists and dicts referenced through typval "tv" with "copyID".
5685  * "list_stack" is used to add lists to be marked.  Can be NULL.
5686  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5687  *
5688  * Returns TRUE if setting references failed somehow.
5689  */
5690     int
5691 set_ref_in_item(
5692     typval_T	    *tv,
5693     int		    copyID,
5694     ht_stack_T	    **ht_stack,
5695     list_stack_T    **list_stack)
5696 {
5697     int		abort = FALSE;
5698 
5699     if (tv->v_type == VAR_DICT)
5700     {
5701 	dict_T	*dd = tv->vval.v_dict;
5702 
5703 	if (dd != NULL && dd->dv_copyID != copyID)
5704 	{
5705 	    /* Didn't see this dict yet. */
5706 	    dd->dv_copyID = copyID;
5707 	    if (ht_stack == NULL)
5708 	    {
5709 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
5710 	    }
5711 	    else
5712 	    {
5713 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
5714 		if (newitem == NULL)
5715 		    abort = TRUE;
5716 		else
5717 		{
5718 		    newitem->ht = &dd->dv_hashtab;
5719 		    newitem->prev = *ht_stack;
5720 		    *ht_stack = newitem;
5721 		}
5722 	    }
5723 	}
5724     }
5725     else if (tv->v_type == VAR_LIST)
5726     {
5727 	list_T	*ll = tv->vval.v_list;
5728 
5729 	if (ll != NULL && ll->lv_copyID != copyID)
5730 	{
5731 	    /* Didn't see this list yet. */
5732 	    ll->lv_copyID = copyID;
5733 	    if (list_stack == NULL)
5734 	    {
5735 		abort = set_ref_in_list(ll, copyID, ht_stack);
5736 	    }
5737 	    else
5738 	    {
5739 		list_stack_T *newitem = (list_stack_T*)malloc(
5740 							sizeof(list_stack_T));
5741 		if (newitem == NULL)
5742 		    abort = TRUE;
5743 		else
5744 		{
5745 		    newitem->list = ll;
5746 		    newitem->prev = *list_stack;
5747 		    *list_stack = newitem;
5748 		}
5749 	    }
5750 	}
5751     }
5752     else if (tv->v_type == VAR_FUNC)
5753     {
5754 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
5755     }
5756     else if (tv->v_type == VAR_PARTIAL)
5757     {
5758 	partial_T	*pt = tv->vval.v_partial;
5759 	int		i;
5760 
5761 	/* A partial does not have a copyID, because it cannot contain itself.
5762 	 */
5763 	if (pt != NULL)
5764 	{
5765 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
5766 
5767 	    if (pt->pt_dict != NULL)
5768 	    {
5769 		typval_T dtv;
5770 
5771 		dtv.v_type = VAR_DICT;
5772 		dtv.vval.v_dict = pt->pt_dict;
5773 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5774 	    }
5775 
5776 	    for (i = 0; i < pt->pt_argc; ++i)
5777 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
5778 							ht_stack, list_stack);
5779 	}
5780     }
5781 #ifdef FEAT_JOB_CHANNEL
5782     else if (tv->v_type == VAR_JOB)
5783     {
5784 	job_T	    *job = tv->vval.v_job;
5785 	typval_T    dtv;
5786 
5787 	if (job != NULL && job->jv_copyID != copyID)
5788 	{
5789 	    job->jv_copyID = copyID;
5790 	    if (job->jv_channel != NULL)
5791 	    {
5792 		dtv.v_type = VAR_CHANNEL;
5793 		dtv.vval.v_channel = job->jv_channel;
5794 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5795 	    }
5796 	    if (job->jv_exit_partial != NULL)
5797 	    {
5798 		dtv.v_type = VAR_PARTIAL;
5799 		dtv.vval.v_partial = job->jv_exit_partial;
5800 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5801 	    }
5802 	}
5803     }
5804     else if (tv->v_type == VAR_CHANNEL)
5805     {
5806 	channel_T   *ch =tv->vval.v_channel;
5807 	ch_part_T   part;
5808 	typval_T    dtv;
5809 	jsonq_T	    *jq;
5810 	cbq_T	    *cq;
5811 
5812 	if (ch != NULL && ch->ch_copyID != copyID)
5813 	{
5814 	    ch->ch_copyID = copyID;
5815 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
5816 	    {
5817 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
5818 							     jq = jq->jq_next)
5819 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
5820 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
5821 							     cq = cq->cq_next)
5822 		    if (cq->cq_partial != NULL)
5823 		    {
5824 			dtv.v_type = VAR_PARTIAL;
5825 			dtv.vval.v_partial = cq->cq_partial;
5826 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5827 		    }
5828 		if (ch->ch_part[part].ch_partial != NULL)
5829 		{
5830 		    dtv.v_type = VAR_PARTIAL;
5831 		    dtv.vval.v_partial = ch->ch_part[part].ch_partial;
5832 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5833 		}
5834 	    }
5835 	    if (ch->ch_partial != NULL)
5836 	    {
5837 		dtv.v_type = VAR_PARTIAL;
5838 		dtv.vval.v_partial = ch->ch_partial;
5839 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5840 	    }
5841 	    if (ch->ch_close_partial != NULL)
5842 	    {
5843 		dtv.v_type = VAR_PARTIAL;
5844 		dtv.vval.v_partial = ch->ch_close_partial;
5845 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5846 	    }
5847 	}
5848     }
5849 #endif
5850     return abort;
5851 }
5852 
5853     static char *
5854 get_var_special_name(int nr)
5855 {
5856     switch (nr)
5857     {
5858 	case VVAL_FALSE: return "v:false";
5859 	case VVAL_TRUE:  return "v:true";
5860 	case VVAL_NONE:  return "v:none";
5861 	case VVAL_NULL:  return "v:null";
5862     }
5863     internal_error("get_var_special_name()");
5864     return "42";
5865 }
5866 
5867 /*
5868  * Return a string with the string representation of a variable.
5869  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5870  * "numbuf" is used for a number.
5871  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5872  * When both "echo_style" and "composite_val" are FALSE, put quotes around
5873  * stings as "string()", otherwise does not put quotes around strings, as
5874  * ":echo" displays values.
5875  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
5876  * are replaced with "...".
5877  * May return NULL.
5878  */
5879     char_u *
5880 echo_string_core(
5881     typval_T	*tv,
5882     char_u	**tofree,
5883     char_u	*numbuf,
5884     int		copyID,
5885     int		echo_style,
5886     int		restore_copyID,
5887     int		composite_val)
5888 {
5889     static int	recurse = 0;
5890     char_u	*r = NULL;
5891 
5892     if (recurse >= DICT_MAXNEST)
5893     {
5894 	if (!did_echo_string_emsg)
5895 	{
5896 	    /* Only give this message once for a recursive call to avoid
5897 	     * flooding the user with errors.  And stop iterating over lists
5898 	     * and dicts. */
5899 	    did_echo_string_emsg = TRUE;
5900 	    emsg(_("E724: variable nested too deep for displaying"));
5901 	}
5902 	*tofree = NULL;
5903 	return (char_u *)"{E724}";
5904     }
5905     ++recurse;
5906 
5907     switch (tv->v_type)
5908     {
5909 	case VAR_STRING:
5910 	    if (echo_style && !composite_val)
5911 	    {
5912 		*tofree = NULL;
5913 		r = tv->vval.v_string;
5914 		if (r == NULL)
5915 		    r = (char_u *)"";
5916 	    }
5917 	    else
5918 	    {
5919 		*tofree = string_quote(tv->vval.v_string, FALSE);
5920 		r = *tofree;
5921 	    }
5922 	    break;
5923 
5924 	case VAR_FUNC:
5925 	    if (echo_style)
5926 	    {
5927 		*tofree = NULL;
5928 		r = tv->vval.v_string;
5929 	    }
5930 	    else
5931 	    {
5932 		*tofree = string_quote(tv->vval.v_string, TRUE);
5933 		r = *tofree;
5934 	    }
5935 	    break;
5936 
5937 	case VAR_PARTIAL:
5938 	    {
5939 		partial_T   *pt = tv->vval.v_partial;
5940 		char_u	    *fname = string_quote(pt == NULL ? NULL
5941 						    : partial_name(pt), FALSE);
5942 		garray_T    ga;
5943 		int	    i;
5944 		char_u	    *tf;
5945 
5946 		ga_init2(&ga, 1, 100);
5947 		ga_concat(&ga, (char_u *)"function(");
5948 		if (fname != NULL)
5949 		{
5950 		    ga_concat(&ga, fname);
5951 		    vim_free(fname);
5952 		}
5953 		if (pt != NULL && pt->pt_argc > 0)
5954 		{
5955 		    ga_concat(&ga, (char_u *)", [");
5956 		    for (i = 0; i < pt->pt_argc; ++i)
5957 		    {
5958 			if (i > 0)
5959 			    ga_concat(&ga, (char_u *)", ");
5960 			ga_concat(&ga,
5961 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
5962 			vim_free(tf);
5963 		    }
5964 		    ga_concat(&ga, (char_u *)"]");
5965 		}
5966 		if (pt != NULL && pt->pt_dict != NULL)
5967 		{
5968 		    typval_T dtv;
5969 
5970 		    ga_concat(&ga, (char_u *)", ");
5971 		    dtv.v_type = VAR_DICT;
5972 		    dtv.vval.v_dict = pt->pt_dict;
5973 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
5974 		    vim_free(tf);
5975 		}
5976 		ga_concat(&ga, (char_u *)")");
5977 
5978 		*tofree = ga.ga_data;
5979 		r = *tofree;
5980 		break;
5981 	    }
5982 
5983 	case VAR_BLOB:
5984 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
5985 	    break;
5986 
5987 	case VAR_LIST:
5988 	    if (tv->vval.v_list == NULL)
5989 	    {
5990 		*tofree = NULL;
5991 		r = NULL;
5992 	    }
5993 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
5994 		    && tv->vval.v_list->lv_len > 0)
5995 	    {
5996 		*tofree = NULL;
5997 		r = (char_u *)"[...]";
5998 	    }
5999 	    else
6000 	    {
6001 		int old_copyID = tv->vval.v_list->lv_copyID;
6002 
6003 		tv->vval.v_list->lv_copyID = copyID;
6004 		*tofree = list2string(tv, copyID, restore_copyID);
6005 		if (restore_copyID)
6006 		    tv->vval.v_list->lv_copyID = old_copyID;
6007 		r = *tofree;
6008 	    }
6009 	    break;
6010 
6011 	case VAR_DICT:
6012 	    if (tv->vval.v_dict == NULL)
6013 	    {
6014 		*tofree = NULL;
6015 		r = NULL;
6016 	    }
6017 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
6018 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
6019 	    {
6020 		*tofree = NULL;
6021 		r = (char_u *)"{...}";
6022 	    }
6023 	    else
6024 	    {
6025 		int old_copyID = tv->vval.v_dict->dv_copyID;
6026 		tv->vval.v_dict->dv_copyID = copyID;
6027 		*tofree = dict2string(tv, copyID, restore_copyID);
6028 		if (restore_copyID)
6029 		    tv->vval.v_dict->dv_copyID = old_copyID;
6030 		r = *tofree;
6031 	    }
6032 	    break;
6033 
6034 	case VAR_NUMBER:
6035 	case VAR_UNKNOWN:
6036 	    *tofree = NULL;
6037 	    r = tv_get_string_buf(tv, numbuf);
6038 	    break;
6039 
6040 	case VAR_JOB:
6041 	case VAR_CHANNEL:
6042 	    *tofree = NULL;
6043 	    r = tv_get_string_buf(tv, numbuf);
6044 	    if (composite_val)
6045 	    {
6046 		*tofree = string_quote(r, FALSE);
6047 		r = *tofree;
6048 	    }
6049 	    break;
6050 
6051 	case VAR_FLOAT:
6052 #ifdef FEAT_FLOAT
6053 	    *tofree = NULL;
6054 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
6055 	    r = numbuf;
6056 	    break;
6057 #endif
6058 
6059 	case VAR_SPECIAL:
6060 	    *tofree = NULL;
6061 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
6062 	    break;
6063     }
6064 
6065     if (--recurse == 0)
6066 	did_echo_string_emsg = FALSE;
6067     return r;
6068 }
6069 
6070 /*
6071  * Return a string with the string representation of a variable.
6072  * If the memory is allocated "tofree" is set to it, otherwise NULL.
6073  * "numbuf" is used for a number.
6074  * Does not put quotes around strings, as ":echo" displays values.
6075  * When "copyID" is not NULL replace recursive lists and dicts with "...".
6076  * May return NULL.
6077  */
6078     char_u *
6079 echo_string(
6080     typval_T	*tv,
6081     char_u	**tofree,
6082     char_u	*numbuf,
6083     int		copyID)
6084 {
6085     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
6086 }
6087 
6088 /*
6089  * Return a string with the string representation of a variable.
6090  * If the memory is allocated "tofree" is set to it, otherwise NULL.
6091  * "numbuf" is used for a number.
6092  * Puts quotes around strings, so that they can be parsed back by eval().
6093  * May return NULL.
6094  */
6095     char_u *
6096 tv2string(
6097     typval_T	*tv,
6098     char_u	**tofree,
6099     char_u	*numbuf,
6100     int		copyID)
6101 {
6102     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
6103 }
6104 
6105 /*
6106  * Return string "str" in ' quotes, doubling ' characters.
6107  * If "str" is NULL an empty string is assumed.
6108  * If "function" is TRUE make it function('string').
6109  */
6110     char_u *
6111 string_quote(char_u *str, int function)
6112 {
6113     unsigned	len;
6114     char_u	*p, *r, *s;
6115 
6116     len = (function ? 13 : 3);
6117     if (str != NULL)
6118     {
6119 	len += (unsigned)STRLEN(str);
6120 	for (p = str; *p != NUL; MB_PTR_ADV(p))
6121 	    if (*p == '\'')
6122 		++len;
6123     }
6124     s = r = alloc(len);
6125     if (r != NULL)
6126     {
6127 	if (function)
6128 	{
6129 	    STRCPY(r, "function('");
6130 	    r += 10;
6131 	}
6132 	else
6133 	    *r++ = '\'';
6134 	if (str != NULL)
6135 	    for (p = str; *p != NUL; )
6136 	    {
6137 		if (*p == '\'')
6138 		    *r++ = '\'';
6139 		MB_COPY_CHAR(p, r);
6140 	    }
6141 	*r++ = '\'';
6142 	if (function)
6143 	    *r++ = ')';
6144 	*r++ = NUL;
6145     }
6146     return s;
6147 }
6148 
6149 #if defined(FEAT_FLOAT) || defined(PROTO)
6150 /*
6151  * Convert the string "text" to a floating point number.
6152  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
6153  * this always uses a decimal point.
6154  * Returns the length of the text that was consumed.
6155  */
6156     int
6157 string2float(
6158     char_u	*text,
6159     float_T	*value)	    /* result stored here */
6160 {
6161     char	*s = (char *)text;
6162     float_T	f;
6163 
6164     /* MS-Windows does not deal with "inf" and "nan" properly. */
6165     if (STRNICMP(text, "inf", 3) == 0)
6166     {
6167 	*value = INFINITY;
6168 	return 3;
6169     }
6170     if (STRNICMP(text, "-inf", 3) == 0)
6171     {
6172 	*value = -INFINITY;
6173 	return 4;
6174     }
6175     if (STRNICMP(text, "nan", 3) == 0)
6176     {
6177 	*value = NAN;
6178 	return 3;
6179     }
6180     f = strtod(s, &s);
6181     *value = f;
6182     return (int)((char_u *)s - text);
6183 }
6184 #endif
6185 
6186 /*
6187  * Get the value of an environment variable.
6188  * "arg" is pointing to the '$'.  It is advanced to after the name.
6189  * If the environment variable was not set, silently assume it is empty.
6190  * Return FAIL if the name is invalid.
6191  */
6192     static int
6193 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
6194 {
6195     char_u	*string = NULL;
6196     int		len;
6197     int		cc;
6198     char_u	*name;
6199     int		mustfree = FALSE;
6200 
6201     ++*arg;
6202     name = *arg;
6203     len = get_env_len(arg);
6204     if (evaluate)
6205     {
6206 	if (len == 0)
6207 	    return FAIL; /* invalid empty name */
6208 
6209 	cc = name[len];
6210 	name[len] = NUL;
6211 	/* first try vim_getenv(), fast for normal environment vars */
6212 	string = vim_getenv(name, &mustfree);
6213 	if (string != NULL && *string != NUL)
6214 	{
6215 	    if (!mustfree)
6216 		string = vim_strsave(string);
6217 	}
6218 	else
6219 	{
6220 	    if (mustfree)
6221 		vim_free(string);
6222 
6223 	    /* next try expanding things like $VIM and ${HOME} */
6224 	    string = expand_env_save(name - 1);
6225 	    if (string != NULL && *string == '$')
6226 		VIM_CLEAR(string);
6227 	}
6228 	name[len] = cc;
6229 
6230 	rettv->v_type = VAR_STRING;
6231 	rettv->vval.v_string = string;
6232     }
6233 
6234     return OK;
6235 }
6236 
6237 
6238 
6239 /*
6240  * Translate a String variable into a position.
6241  * Returns NULL when there is an error.
6242  */
6243     pos_T *
6244 var2fpos(
6245     typval_T	*varp,
6246     int		dollar_lnum,	/* TRUE when $ is last line */
6247     int		*fnum)		/* set to fnum for '0, 'A, etc. */
6248 {
6249     char_u		*name;
6250     static pos_T	pos;
6251     pos_T		*pp;
6252 
6253     /* Argument can be [lnum, col, coladd]. */
6254     if (varp->v_type == VAR_LIST)
6255     {
6256 	list_T		*l;
6257 	int		len;
6258 	int		error = FALSE;
6259 	listitem_T	*li;
6260 
6261 	l = varp->vval.v_list;
6262 	if (l == NULL)
6263 	    return NULL;
6264 
6265 	/* Get the line number */
6266 	pos.lnum = list_find_nr(l, 0L, &error);
6267 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
6268 	    return NULL;	/* invalid line number */
6269 
6270 	/* Get the column number */
6271 	pos.col = list_find_nr(l, 1L, &error);
6272 	if (error)
6273 	    return NULL;
6274 	len = (long)STRLEN(ml_get(pos.lnum));
6275 
6276 	/* We accept "$" for the column number: last column. */
6277 	li = list_find(l, 1L);
6278 	if (li != NULL && li->li_tv.v_type == VAR_STRING
6279 		&& li->li_tv.vval.v_string != NULL
6280 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
6281 	    pos.col = len + 1;
6282 
6283 	/* Accept a position up to the NUL after the line. */
6284 	if (pos.col == 0 || (int)pos.col > len + 1)
6285 	    return NULL;	/* invalid column number */
6286 	--pos.col;
6287 
6288 	/* Get the virtual offset.  Defaults to zero. */
6289 	pos.coladd = list_find_nr(l, 2L, &error);
6290 	if (error)
6291 	    pos.coladd = 0;
6292 
6293 	return &pos;
6294     }
6295 
6296     name = tv_get_string_chk(varp);
6297     if (name == NULL)
6298 	return NULL;
6299     if (name[0] == '.')				/* cursor */
6300 	return &curwin->w_cursor;
6301     if (name[0] == 'v' && name[1] == NUL)	/* Visual start */
6302     {
6303 	if (VIsual_active)
6304 	    return &VIsual;
6305 	return &curwin->w_cursor;
6306     }
6307     if (name[0] == '\'')			/* mark */
6308     {
6309 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
6310 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
6311 	    return NULL;
6312 	return pp;
6313     }
6314 
6315     pos.coladd = 0;
6316 
6317     if (name[0] == 'w' && dollar_lnum)
6318     {
6319 	pos.col = 0;
6320 	if (name[1] == '0')		/* "w0": first visible line */
6321 	{
6322 	    update_topline();
6323 	    /* In silent Ex mode topline is zero, but that's not a valid line
6324 	     * number; use one instead. */
6325 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
6326 	    return &pos;
6327 	}
6328 	else if (name[1] == '$')	/* "w$": last visible line */
6329 	{
6330 	    validate_botline();
6331 	    /* In silent Ex mode botline is zero, return zero then. */
6332 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
6333 	    return &pos;
6334 	}
6335     }
6336     else if (name[0] == '$')		/* last column or line */
6337     {
6338 	if (dollar_lnum)
6339 	{
6340 	    pos.lnum = curbuf->b_ml.ml_line_count;
6341 	    pos.col = 0;
6342 	}
6343 	else
6344 	{
6345 	    pos.lnum = curwin->w_cursor.lnum;
6346 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
6347 	}
6348 	return &pos;
6349     }
6350     return NULL;
6351 }
6352 
6353 /*
6354  * Convert list in "arg" into a position and optional file number.
6355  * When "fnump" is NULL there is no file number, only 3 items.
6356  * Note that the column is passed on as-is, the caller may want to decrement
6357  * it to use 1 for the first column.
6358  * Return FAIL when conversion is not possible, doesn't check the position for
6359  * validity.
6360  */
6361     int
6362 list2fpos(
6363     typval_T	*arg,
6364     pos_T	*posp,
6365     int		*fnump,
6366     colnr_T	*curswantp)
6367 {
6368     list_T	*l = arg->vval.v_list;
6369     long	i = 0;
6370     long	n;
6371 
6372     /* List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
6373      * there when "fnump" isn't NULL; "coladd" and "curswant" are optional. */
6374     if (arg->v_type != VAR_LIST
6375 	    || l == NULL
6376 	    || l->lv_len < (fnump == NULL ? 2 : 3)
6377 	    || l->lv_len > (fnump == NULL ? 4 : 5))
6378 	return FAIL;
6379 
6380     if (fnump != NULL)
6381     {
6382 	n = list_find_nr(l, i++, NULL);	/* fnum */
6383 	if (n < 0)
6384 	    return FAIL;
6385 	if (n == 0)
6386 	    n = curbuf->b_fnum;		/* current buffer */
6387 	*fnump = n;
6388     }
6389 
6390     n = list_find_nr(l, i++, NULL);	/* lnum */
6391     if (n < 0)
6392 	return FAIL;
6393     posp->lnum = n;
6394 
6395     n = list_find_nr(l, i++, NULL);	/* col */
6396     if (n < 0)
6397 	return FAIL;
6398     posp->col = n;
6399 
6400     n = list_find_nr(l, i, NULL);	/* off */
6401     if (n < 0)
6402 	posp->coladd = 0;
6403     else
6404 	posp->coladd = n;
6405 
6406     if (curswantp != NULL)
6407 	*curswantp = list_find_nr(l, i + 1, NULL);  /* curswant */
6408 
6409     return OK;
6410 }
6411 
6412 /*
6413  * Get the length of an environment variable name.
6414  * Advance "arg" to the first character after the name.
6415  * Return 0 for error.
6416  */
6417     static int
6418 get_env_len(char_u **arg)
6419 {
6420     char_u	*p;
6421     int		len;
6422 
6423     for (p = *arg; vim_isIDc(*p); ++p)
6424 	;
6425     if (p == *arg)	    /* no name found */
6426 	return 0;
6427 
6428     len = (int)(p - *arg);
6429     *arg = p;
6430     return len;
6431 }
6432 
6433 /*
6434  * Get the length of the name of a function or internal variable.
6435  * "arg" is advanced to the first non-white character after the name.
6436  * Return 0 if something is wrong.
6437  */
6438     int
6439 get_id_len(char_u **arg)
6440 {
6441     char_u	*p;
6442     int		len;
6443 
6444     /* Find the end of the name. */
6445     for (p = *arg; eval_isnamec(*p); ++p)
6446     {
6447 	if (*p == ':')
6448 	{
6449 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6450 	     * slice "[n:]".  Also "xx:" is not a namespace. */
6451 	    len = (int)(p - *arg);
6452 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
6453 		    || len > 1)
6454 		break;
6455 	}
6456     }
6457     if (p == *arg)	    /* no name found */
6458 	return 0;
6459 
6460     len = (int)(p - *arg);
6461     *arg = skipwhite(p);
6462 
6463     return len;
6464 }
6465 
6466 /*
6467  * Get the length of the name of a variable or function.
6468  * Only the name is recognized, does not handle ".key" or "[idx]".
6469  * "arg" is advanced to the first non-white character after the name.
6470  * Return -1 if curly braces expansion failed.
6471  * Return 0 if something else is wrong.
6472  * If the name contains 'magic' {}'s, expand them and return the
6473  * expanded name in an allocated string via 'alias' - caller must free.
6474  */
6475     int
6476 get_name_len(
6477     char_u	**arg,
6478     char_u	**alias,
6479     int		evaluate,
6480     int		verbose)
6481 {
6482     int		len;
6483     char_u	*p;
6484     char_u	*expr_start;
6485     char_u	*expr_end;
6486 
6487     *alias = NULL;  /* default to no alias */
6488 
6489     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
6490 						  && (*arg)[2] == (int)KE_SNR)
6491     {
6492 	/* hard coded <SNR>, already translated */
6493 	*arg += 3;
6494 	return get_id_len(arg) + 3;
6495     }
6496     len = eval_fname_script(*arg);
6497     if (len > 0)
6498     {
6499 	/* literal "<SID>", "s:" or "<SNR>" */
6500 	*arg += len;
6501     }
6502 
6503     /*
6504      * Find the end of the name; check for {} construction.
6505      */
6506     p = find_name_end(*arg, &expr_start, &expr_end,
6507 					       len > 0 ? 0 : FNE_CHECK_START);
6508     if (expr_start != NULL)
6509     {
6510 	char_u	*temp_string;
6511 
6512 	if (!evaluate)
6513 	{
6514 	    len += (int)(p - *arg);
6515 	    *arg = skipwhite(p);
6516 	    return len;
6517 	}
6518 
6519 	/*
6520 	 * Include any <SID> etc in the expanded string:
6521 	 * Thus the -len here.
6522 	 */
6523 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
6524 	if (temp_string == NULL)
6525 	    return -1;
6526 	*alias = temp_string;
6527 	*arg = skipwhite(p);
6528 	return (int)STRLEN(temp_string);
6529     }
6530 
6531     len += get_id_len(arg);
6532     // Only give an error when there is something, otherwise it will be
6533     // reported at a higher level.
6534     if (len == 0 && verbose && **arg != NUL)
6535 	semsg(_(e_invexpr2), *arg);
6536 
6537     return len;
6538 }
6539 
6540 /*
6541  * Find the end of a variable or function name, taking care of magic braces.
6542  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
6543  * start and end of the first magic braces item.
6544  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
6545  * Return a pointer to just after the name.  Equal to "arg" if there is no
6546  * valid name.
6547  */
6548     char_u *
6549 find_name_end(
6550     char_u	*arg,
6551     char_u	**expr_start,
6552     char_u	**expr_end,
6553     int		flags)
6554 {
6555     int		mb_nest = 0;
6556     int		br_nest = 0;
6557     char_u	*p;
6558     int		len;
6559 
6560     if (expr_start != NULL)
6561     {
6562 	*expr_start = NULL;
6563 	*expr_end = NULL;
6564     }
6565 
6566     /* Quick check for valid starting character. */
6567     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg) && *arg != '{')
6568 	return arg;
6569 
6570     for (p = arg; *p != NUL
6571 		    && (eval_isnamec(*p)
6572 			|| *p == '{'
6573 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
6574 			|| mb_nest != 0
6575 			|| br_nest != 0); MB_PTR_ADV(p))
6576     {
6577 	if (*p == '\'')
6578 	{
6579 	    /* skip over 'string' to avoid counting [ and ] inside it. */
6580 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
6581 		;
6582 	    if (*p == NUL)
6583 		break;
6584 	}
6585 	else if (*p == '"')
6586 	{
6587 	    /* skip over "str\"ing" to avoid counting [ and ] inside it. */
6588 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
6589 		if (*p == '\\' && p[1] != NUL)
6590 		    ++p;
6591 	    if (*p == NUL)
6592 		break;
6593 	}
6594 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
6595 	{
6596 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6597 	     * slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is. */
6598 	    len = (int)(p - arg);
6599 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
6600 		    || (len > 1 && p[-1] != '}'))
6601 		break;
6602 	}
6603 
6604 	if (mb_nest == 0)
6605 	{
6606 	    if (*p == '[')
6607 		++br_nest;
6608 	    else if (*p == ']')
6609 		--br_nest;
6610 	}
6611 
6612 	if (br_nest == 0)
6613 	{
6614 	    if (*p == '{')
6615 	    {
6616 		mb_nest++;
6617 		if (expr_start != NULL && *expr_start == NULL)
6618 		    *expr_start = p;
6619 	    }
6620 	    else if (*p == '}')
6621 	    {
6622 		mb_nest--;
6623 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
6624 		    *expr_end = p;
6625 	    }
6626 	}
6627     }
6628 
6629     return p;
6630 }
6631 
6632 /*
6633  * Expands out the 'magic' {}'s in a variable/function name.
6634  * Note that this can call itself recursively, to deal with
6635  * constructs like foo{bar}{baz}{bam}
6636  * The four pointer arguments point to "foo{expre}ss{ion}bar"
6637  *			"in_start"      ^
6638  *			"expr_start"	   ^
6639  *			"expr_end"		 ^
6640  *			"in_end"			    ^
6641  *
6642  * Returns a new allocated string, which the caller must free.
6643  * Returns NULL for failure.
6644  */
6645     static char_u *
6646 make_expanded_name(
6647     char_u	*in_start,
6648     char_u	*expr_start,
6649     char_u	*expr_end,
6650     char_u	*in_end)
6651 {
6652     char_u	c1;
6653     char_u	*retval = NULL;
6654     char_u	*temp_result;
6655     char_u	*nextcmd = NULL;
6656 
6657     if (expr_end == NULL || in_end == NULL)
6658 	return NULL;
6659     *expr_start	= NUL;
6660     *expr_end = NUL;
6661     c1 = *in_end;
6662     *in_end = NUL;
6663 
6664     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
6665     if (temp_result != NULL && nextcmd == NULL)
6666     {
6667 	retval = alloc((unsigned)(STRLEN(temp_result) + (expr_start - in_start)
6668 						   + (in_end - expr_end) + 1));
6669 	if (retval != NULL)
6670 	{
6671 	    STRCPY(retval, in_start);
6672 	    STRCAT(retval, temp_result);
6673 	    STRCAT(retval, expr_end + 1);
6674 	}
6675     }
6676     vim_free(temp_result);
6677 
6678     *in_end = c1;		/* put char back for error messages */
6679     *expr_start = '{';
6680     *expr_end = '}';
6681 
6682     if (retval != NULL)
6683     {
6684 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
6685 	if (expr_start != NULL)
6686 	{
6687 	    /* Further expansion! */
6688 	    temp_result = make_expanded_name(retval, expr_start,
6689 						       expr_end, temp_result);
6690 	    vim_free(retval);
6691 	    retval = temp_result;
6692 	}
6693     }
6694 
6695     return retval;
6696 }
6697 
6698 /*
6699  * Return TRUE if character "c" can be used in a variable or function name.
6700  * Does not include '{' or '}' for magic braces.
6701  */
6702     int
6703 eval_isnamec(int c)
6704 {
6705     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
6706 }
6707 
6708 /*
6709  * Return TRUE if character "c" can be used as the first character in a
6710  * variable or function name (excluding '{' and '}').
6711  */
6712     int
6713 eval_isnamec1(int c)
6714 {
6715     return (ASCII_ISALPHA(c) || c == '_');
6716 }
6717 
6718 /*
6719  * Set number v: variable to "val".
6720  */
6721     void
6722 set_vim_var_nr(int idx, varnumber_T val)
6723 {
6724     vimvars[idx].vv_nr = val;
6725 }
6726 
6727 /*
6728  * Get number v: variable value.
6729  */
6730     varnumber_T
6731 get_vim_var_nr(int idx)
6732 {
6733     return vimvars[idx].vv_nr;
6734 }
6735 
6736 /*
6737  * Get string v: variable value.  Uses a static buffer, can only be used once.
6738  * If the String variable has never been set, return an empty string.
6739  * Never returns NULL;
6740  */
6741     char_u *
6742 get_vim_var_str(int idx)
6743 {
6744     return tv_get_string(&vimvars[idx].vv_tv);
6745 }
6746 
6747 /*
6748  * Get List v: variable value.  Caller must take care of reference count when
6749  * needed.
6750  */
6751     list_T *
6752 get_vim_var_list(int idx)
6753 {
6754     return vimvars[idx].vv_list;
6755 }
6756 
6757 /*
6758  * Get Dict v: variable value.  Caller must take care of reference count when
6759  * needed.
6760  */
6761     dict_T *
6762 get_vim_var_dict(int idx)
6763 {
6764     return vimvars[idx].vv_dict;
6765 }
6766 
6767 /*
6768  * Set v:char to character "c".
6769  */
6770     void
6771 set_vim_var_char(int c)
6772 {
6773     char_u	buf[MB_MAXBYTES + 1];
6774 
6775     if (has_mbyte)
6776 	buf[(*mb_char2bytes)(c, buf)] = NUL;
6777     else
6778     {
6779 	buf[0] = c;
6780 	buf[1] = NUL;
6781     }
6782     set_vim_var_string(VV_CHAR, buf, -1);
6783 }
6784 
6785 /*
6786  * Set v:count to "count" and v:count1 to "count1".
6787  * When "set_prevcount" is TRUE first set v:prevcount from v:count.
6788  */
6789     void
6790 set_vcount(
6791     long	count,
6792     long	count1,
6793     int		set_prevcount)
6794 {
6795     if (set_prevcount)
6796 	vimvars[VV_PREVCOUNT].vv_nr = vimvars[VV_COUNT].vv_nr;
6797     vimvars[VV_COUNT].vv_nr = count;
6798     vimvars[VV_COUNT1].vv_nr = count1;
6799 }
6800 
6801 /*
6802  * Save variables that might be changed as a side effect.  Used when executing
6803  * a timer callback.
6804  */
6805     void
6806 save_vimvars(vimvars_save_T *vvsave)
6807 {
6808     vvsave->vv_prevcount = vimvars[VV_PREVCOUNT].vv_nr;
6809     vvsave->vv_count = vimvars[VV_COUNT].vv_nr;
6810     vvsave->vv_count1 = vimvars[VV_COUNT1].vv_nr;
6811 }
6812 
6813 /*
6814  * Restore variables saved by save_vimvars().
6815  */
6816     void
6817 restore_vimvars(vimvars_save_T *vvsave)
6818 {
6819     vimvars[VV_PREVCOUNT].vv_nr = vvsave->vv_prevcount;
6820     vimvars[VV_COUNT].vv_nr = vvsave->vv_count;
6821     vimvars[VV_COUNT1].vv_nr = vvsave->vv_count1;
6822 }
6823 
6824 /*
6825  * Set string v: variable to a copy of "val".
6826  */
6827     void
6828 set_vim_var_string(
6829     int		idx,
6830     char_u	*val,
6831     int		len)	    /* length of "val" to use or -1 (whole string) */
6832 {
6833     clear_tv(&vimvars[idx].vv_di.di_tv);
6834     vimvars[idx].vv_type = VAR_STRING;
6835     if (val == NULL)
6836 	vimvars[idx].vv_str = NULL;
6837     else if (len == -1)
6838 	vimvars[idx].vv_str = vim_strsave(val);
6839     else
6840 	vimvars[idx].vv_str = vim_strnsave(val, len);
6841 }
6842 
6843 /*
6844  * Set List v: variable to "val".
6845  */
6846     void
6847 set_vim_var_list(int idx, list_T *val)
6848 {
6849     clear_tv(&vimvars[idx].vv_di.di_tv);
6850     vimvars[idx].vv_type = VAR_LIST;
6851     vimvars[idx].vv_list = val;
6852     if (val != NULL)
6853 	++val->lv_refcount;
6854 }
6855 
6856 /*
6857  * Set Dictionary v: variable to "val".
6858  */
6859     void
6860 set_vim_var_dict(int idx, dict_T *val)
6861 {
6862     clear_tv(&vimvars[idx].vv_di.di_tv);
6863     vimvars[idx].vv_type = VAR_DICT;
6864     vimvars[idx].vv_dict = val;
6865     if (val != NULL)
6866     {
6867 	++val->dv_refcount;
6868 	dict_set_items_ro(val);
6869     }
6870 }
6871 
6872 /*
6873  * Set v:register if needed.
6874  */
6875     void
6876 set_reg_var(int c)
6877 {
6878     char_u	regname;
6879 
6880     if (c == 0 || c == ' ')
6881 	regname = '"';
6882     else
6883 	regname = c;
6884     /* Avoid free/alloc when the value is already right. */
6885     if (vimvars[VV_REG].vv_str == NULL || vimvars[VV_REG].vv_str[0] != c)
6886 	set_vim_var_string(VV_REG, &regname, 1);
6887 }
6888 
6889 /*
6890  * Get or set v:exception.  If "oldval" == NULL, return the current value.
6891  * Otherwise, restore the value to "oldval" and return NULL.
6892  * Must always be called in pairs to save and restore v:exception!  Does not
6893  * take care of memory allocations.
6894  */
6895     char_u *
6896 v_exception(char_u *oldval)
6897 {
6898     if (oldval == NULL)
6899 	return vimvars[VV_EXCEPTION].vv_str;
6900 
6901     vimvars[VV_EXCEPTION].vv_str = oldval;
6902     return NULL;
6903 }
6904 
6905 /*
6906  * Get or set v:throwpoint.  If "oldval" == NULL, return the current value.
6907  * Otherwise, restore the value to "oldval" and return NULL.
6908  * Must always be called in pairs to save and restore v:throwpoint!  Does not
6909  * take care of memory allocations.
6910  */
6911     char_u *
6912 v_throwpoint(char_u *oldval)
6913 {
6914     if (oldval == NULL)
6915 	return vimvars[VV_THROWPOINT].vv_str;
6916 
6917     vimvars[VV_THROWPOINT].vv_str = oldval;
6918     return NULL;
6919 }
6920 
6921 /*
6922  * Set v:cmdarg.
6923  * If "eap" != NULL, use "eap" to generate the value and return the old value.
6924  * If "oldarg" != NULL, restore the value to "oldarg" and return NULL.
6925  * Must always be called in pairs!
6926  */
6927     char_u *
6928 set_cmdarg(exarg_T *eap, char_u *oldarg)
6929 {
6930     char_u	*oldval;
6931     char_u	*newval;
6932     unsigned	len;
6933 
6934     oldval = vimvars[VV_CMDARG].vv_str;
6935     if (eap == NULL)
6936     {
6937 	vim_free(oldval);
6938 	vimvars[VV_CMDARG].vv_str = oldarg;
6939 	return NULL;
6940     }
6941 
6942     if (eap->force_bin == FORCE_BIN)
6943 	len = 6;
6944     else if (eap->force_bin == FORCE_NOBIN)
6945 	len = 8;
6946     else
6947 	len = 0;
6948 
6949     if (eap->read_edit)
6950 	len += 7;
6951 
6952     if (eap->force_ff != 0)
6953 	len += 10; /* " ++ff=unix" */
6954     if (eap->force_enc != 0)
6955 	len += (unsigned)STRLEN(eap->cmd + eap->force_enc) + 7;
6956     if (eap->bad_char != 0)
6957 	len += 7 + 4;  /* " ++bad=" + "keep" or "drop" */
6958 
6959     newval = alloc(len + 1);
6960     if (newval == NULL)
6961 	return NULL;
6962 
6963     if (eap->force_bin == FORCE_BIN)
6964 	sprintf((char *)newval, " ++bin");
6965     else if (eap->force_bin == FORCE_NOBIN)
6966 	sprintf((char *)newval, " ++nobin");
6967     else
6968 	*newval = NUL;
6969 
6970     if (eap->read_edit)
6971 	STRCAT(newval, " ++edit");
6972 
6973     if (eap->force_ff != 0)
6974 	sprintf((char *)newval + STRLEN(newval), " ++ff=%s",
6975 						eap->force_ff == 'u' ? "unix"
6976 						: eap->force_ff == 'd' ? "dos"
6977 						: "mac");
6978     if (eap->force_enc != 0)
6979 	sprintf((char *)newval + STRLEN(newval), " ++enc=%s",
6980 					       eap->cmd + eap->force_enc);
6981     if (eap->bad_char == BAD_KEEP)
6982 	STRCPY(newval + STRLEN(newval), " ++bad=keep");
6983     else if (eap->bad_char == BAD_DROP)
6984 	STRCPY(newval + STRLEN(newval), " ++bad=drop");
6985     else if (eap->bad_char != 0)
6986 	sprintf((char *)newval + STRLEN(newval), " ++bad=%c", eap->bad_char);
6987     vimvars[VV_CMDARG].vv_str = newval;
6988     return oldval;
6989 }
6990 
6991 /*
6992  * Get the value of internal variable "name".
6993  * Return OK or FAIL.  If OK is returned "rettv" must be cleared.
6994  */
6995     int
6996 get_var_tv(
6997     char_u	*name,
6998     int		len,		/* length of "name" */
6999     typval_T	*rettv,		/* NULL when only checking existence */
7000     dictitem_T	**dip,		/* non-NULL when typval's dict item is needed */
7001     int		verbose,	/* may give error message */
7002     int		no_autoload)	/* do not use script autoloading */
7003 {
7004     int		ret = OK;
7005     typval_T	*tv = NULL;
7006     dictitem_T	*v;
7007     int		cc;
7008 
7009     /* truncate the name, so that we can use strcmp() */
7010     cc = name[len];
7011     name[len] = NUL;
7012 
7013     /*
7014      * Check for user-defined variables.
7015      */
7016     v = find_var(name, NULL, no_autoload);
7017     if (v != NULL)
7018     {
7019 	tv = &v->di_tv;
7020 	if (dip != NULL)
7021 	    *dip = v;
7022     }
7023 
7024     if (tv == NULL)
7025     {
7026 	if (rettv != NULL && verbose)
7027 	    semsg(_(e_undefvar), name);
7028 	ret = FAIL;
7029     }
7030     else if (rettv != NULL)
7031 	copy_tv(tv, rettv);
7032 
7033     name[len] = cc;
7034 
7035     return ret;
7036 }
7037 
7038 /*
7039  * Check if variable "name[len]" is a local variable or an argument.
7040  * If so, "*eval_lavars_used" is set to TRUE.
7041  */
7042     static void
7043 check_vars(char_u *name, int len)
7044 {
7045     int		cc;
7046     char_u	*varname;
7047     hashtab_T	*ht;
7048 
7049     if (eval_lavars_used == NULL)
7050 	return;
7051 
7052     /* truncate the name, so that we can use strcmp() */
7053     cc = name[len];
7054     name[len] = NUL;
7055 
7056     ht = find_var_ht(name, &varname);
7057     if (ht == get_funccal_local_ht() || ht == get_funccal_args_ht())
7058     {
7059 	if (find_var(name, NULL, TRUE) != NULL)
7060 	    *eval_lavars_used = TRUE;
7061     }
7062 
7063     name[len] = cc;
7064 }
7065 
7066 /*
7067  * Handle expr[expr], expr[expr:expr] subscript and .name lookup.
7068  * Also handle function call with Funcref variable: func(expr)
7069  * Can all be combined: dict.func(expr)[idx]['func'](expr)
7070  */
7071     int
7072 handle_subscript(
7073     char_u	**arg,
7074     typval_T	*rettv,
7075     int		evaluate,	/* do more than finding the end */
7076     int		verbose)	/* give error messages */
7077 {
7078     int		ret = OK;
7079     dict_T	*selfdict = NULL;
7080     char_u	*s;
7081     int		len;
7082     typval_T	functv;
7083 
7084     while (ret == OK
7085 	    && (**arg == '['
7086 		|| (**arg == '.' && rettv->v_type == VAR_DICT)
7087 		|| (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
7088 					    || rettv->v_type == VAR_PARTIAL)))
7089 	    && !VIM_ISWHITE(*(*arg - 1)))
7090     {
7091 	if (**arg == '(')
7092 	{
7093 	    partial_T	*pt = NULL;
7094 
7095 	    /* need to copy the funcref so that we can clear rettv */
7096 	    if (evaluate)
7097 	    {
7098 		functv = *rettv;
7099 		rettv->v_type = VAR_UNKNOWN;
7100 
7101 		/* Invoke the function.  Recursive! */
7102 		if (functv.v_type == VAR_PARTIAL)
7103 		{
7104 		    pt = functv.vval.v_partial;
7105 		    s = partial_name(pt);
7106 		}
7107 		else
7108 		    s = functv.vval.v_string;
7109 	    }
7110 	    else
7111 		s = (char_u *)"";
7112 	    ret = get_func_tv(s, -1, rettv, arg,
7113 			curwin->w_cursor.lnum, curwin->w_cursor.lnum,
7114 			&len, evaluate, pt, selfdict);
7115 
7116 	    /* Clear the funcref afterwards, so that deleting it while
7117 	     * evaluating the arguments is possible (see test55). */
7118 	    if (evaluate)
7119 		clear_tv(&functv);
7120 
7121 	    /* Stop the expression evaluation when immediately aborting on
7122 	     * error, or when an interrupt occurred or an exception was thrown
7123 	     * but not caught. */
7124 	    if (aborting())
7125 	    {
7126 		if (ret == OK)
7127 		    clear_tv(rettv);
7128 		ret = FAIL;
7129 	    }
7130 	    dict_unref(selfdict);
7131 	    selfdict = NULL;
7132 	}
7133 	else /* **arg == '[' || **arg == '.' */
7134 	{
7135 	    dict_unref(selfdict);
7136 	    if (rettv->v_type == VAR_DICT)
7137 	    {
7138 		selfdict = rettv->vval.v_dict;
7139 		if (selfdict != NULL)
7140 		    ++selfdict->dv_refcount;
7141 	    }
7142 	    else
7143 		selfdict = NULL;
7144 	    if (eval_index(arg, rettv, evaluate, verbose) == FAIL)
7145 	    {
7146 		clear_tv(rettv);
7147 		ret = FAIL;
7148 	    }
7149 	}
7150     }
7151 
7152     /* Turn "dict.Func" into a partial for "Func" bound to "dict".
7153      * Don't do this when "Func" is already a partial that was bound
7154      * explicitly (pt_auto is FALSE). */
7155     if (selfdict != NULL
7156 	    && (rettv->v_type == VAR_FUNC
7157 		|| (rettv->v_type == VAR_PARTIAL
7158 		    && (rettv->vval.v_partial->pt_auto
7159 			|| rettv->vval.v_partial->pt_dict == NULL))))
7160 	selfdict = make_partial(selfdict, rettv);
7161 
7162     dict_unref(selfdict);
7163     return ret;
7164 }
7165 
7166 /*
7167  * Allocate memory for a variable type-value, and make it empty (0 or NULL
7168  * value).
7169  */
7170     typval_T *
7171 alloc_tv(void)
7172 {
7173     return (typval_T *)alloc_clear((unsigned)sizeof(typval_T));
7174 }
7175 
7176 /*
7177  * Allocate memory for a variable type-value, and assign a string to it.
7178  * The string "s" must have been allocated, it is consumed.
7179  * Return NULL for out of memory, the variable otherwise.
7180  */
7181     static typval_T *
7182 alloc_string_tv(char_u *s)
7183 {
7184     typval_T	*rettv;
7185 
7186     rettv = alloc_tv();
7187     if (rettv != NULL)
7188     {
7189 	rettv->v_type = VAR_STRING;
7190 	rettv->vval.v_string = s;
7191     }
7192     else
7193 	vim_free(s);
7194     return rettv;
7195 }
7196 
7197 /*
7198  * Free the memory for a variable type-value.
7199  */
7200     void
7201 free_tv(typval_T *varp)
7202 {
7203     if (varp != NULL)
7204     {
7205 	switch (varp->v_type)
7206 	{
7207 	    case VAR_FUNC:
7208 		func_unref(varp->vval.v_string);
7209 		/* FALLTHROUGH */
7210 	    case VAR_STRING:
7211 		vim_free(varp->vval.v_string);
7212 		break;
7213 	    case VAR_PARTIAL:
7214 		partial_unref(varp->vval.v_partial);
7215 		break;
7216 	    case VAR_BLOB:
7217 		blob_unref(varp->vval.v_blob);
7218 		break;
7219 	    case VAR_LIST:
7220 		list_unref(varp->vval.v_list);
7221 		break;
7222 	    case VAR_DICT:
7223 		dict_unref(varp->vval.v_dict);
7224 		break;
7225 	    case VAR_JOB:
7226 #ifdef FEAT_JOB_CHANNEL
7227 		job_unref(varp->vval.v_job);
7228 		break;
7229 #endif
7230 	    case VAR_CHANNEL:
7231 #ifdef FEAT_JOB_CHANNEL
7232 		channel_unref(varp->vval.v_channel);
7233 		break;
7234 #endif
7235 	    case VAR_NUMBER:
7236 	    case VAR_FLOAT:
7237 	    case VAR_UNKNOWN:
7238 	    case VAR_SPECIAL:
7239 		break;
7240 	}
7241 	vim_free(varp);
7242     }
7243 }
7244 
7245 /*
7246  * Free the memory for a variable value and set the value to NULL or 0.
7247  */
7248     void
7249 clear_tv(typval_T *varp)
7250 {
7251     if (varp != NULL)
7252     {
7253 	switch (varp->v_type)
7254 	{
7255 	    case VAR_FUNC:
7256 		func_unref(varp->vval.v_string);
7257 		/* FALLTHROUGH */
7258 	    case VAR_STRING:
7259 		VIM_CLEAR(varp->vval.v_string);
7260 		break;
7261 	    case VAR_PARTIAL:
7262 		partial_unref(varp->vval.v_partial);
7263 		varp->vval.v_partial = NULL;
7264 		break;
7265 	    case VAR_BLOB:
7266 		blob_unref(varp->vval.v_blob);
7267 		varp->vval.v_blob = NULL;
7268 		break;
7269 	    case VAR_LIST:
7270 		list_unref(varp->vval.v_list);
7271 		varp->vval.v_list = NULL;
7272 		break;
7273 	    case VAR_DICT:
7274 		dict_unref(varp->vval.v_dict);
7275 		varp->vval.v_dict = NULL;
7276 		break;
7277 	    case VAR_NUMBER:
7278 	    case VAR_SPECIAL:
7279 		varp->vval.v_number = 0;
7280 		break;
7281 	    case VAR_FLOAT:
7282 #ifdef FEAT_FLOAT
7283 		varp->vval.v_float = 0.0;
7284 		break;
7285 #endif
7286 	    case VAR_JOB:
7287 #ifdef FEAT_JOB_CHANNEL
7288 		job_unref(varp->vval.v_job);
7289 		varp->vval.v_job = NULL;
7290 #endif
7291 		break;
7292 	    case VAR_CHANNEL:
7293 #ifdef FEAT_JOB_CHANNEL
7294 		channel_unref(varp->vval.v_channel);
7295 		varp->vval.v_channel = NULL;
7296 #endif
7297 	    case VAR_UNKNOWN:
7298 		break;
7299 	}
7300 	varp->v_lock = 0;
7301     }
7302 }
7303 
7304 /*
7305  * Set the value of a variable to NULL without freeing items.
7306  */
7307     void
7308 init_tv(typval_T *varp)
7309 {
7310     if (varp != NULL)
7311 	vim_memset(varp, 0, sizeof(typval_T));
7312 }
7313 
7314 /*
7315  * Get the number value of a variable.
7316  * If it is a String variable, uses vim_str2nr().
7317  * For incompatible types, return 0.
7318  * tv_get_number_chk() is similar to tv_get_number(), but informs the
7319  * caller of incompatible types: it sets *denote to TRUE if "denote"
7320  * is not NULL or returns -1 otherwise.
7321  */
7322     varnumber_T
7323 tv_get_number(typval_T *varp)
7324 {
7325     int		error = FALSE;
7326 
7327     return tv_get_number_chk(varp, &error);	/* return 0L on error */
7328 }
7329 
7330     varnumber_T
7331 tv_get_number_chk(typval_T *varp, int *denote)
7332 {
7333     varnumber_T	n = 0L;
7334 
7335     switch (varp->v_type)
7336     {
7337 	case VAR_NUMBER:
7338 	    return varp->vval.v_number;
7339 	case VAR_FLOAT:
7340 #ifdef FEAT_FLOAT
7341 	    emsg(_("E805: Using a Float as a Number"));
7342 	    break;
7343 #endif
7344 	case VAR_FUNC:
7345 	case VAR_PARTIAL:
7346 	    emsg(_("E703: Using a Funcref as a Number"));
7347 	    break;
7348 	case VAR_STRING:
7349 	    if (varp->vval.v_string != NULL)
7350 		vim_str2nr(varp->vval.v_string, NULL, NULL,
7351 						    STR2NR_ALL, &n, NULL, 0);
7352 	    return n;
7353 	case VAR_LIST:
7354 	    emsg(_("E745: Using a List as a Number"));
7355 	    break;
7356 	case VAR_DICT:
7357 	    emsg(_("E728: Using a Dictionary as a Number"));
7358 	    break;
7359 	case VAR_SPECIAL:
7360 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
7361 	    break;
7362 	case VAR_JOB:
7363 #ifdef FEAT_JOB_CHANNEL
7364 	    emsg(_("E910: Using a Job as a Number"));
7365 	    break;
7366 #endif
7367 	case VAR_CHANNEL:
7368 #ifdef FEAT_JOB_CHANNEL
7369 	    emsg(_("E913: Using a Channel as a Number"));
7370 	    break;
7371 #endif
7372 	case VAR_BLOB:
7373 	    emsg(_("E974: Using a Blob as a Number"));
7374 	    break;
7375 	case VAR_UNKNOWN:
7376 	    internal_error("tv_get_number(UNKNOWN)");
7377 	    break;
7378     }
7379     if (denote == NULL)		/* useful for values that must be unsigned */
7380 	n = -1;
7381     else
7382 	*denote = TRUE;
7383     return n;
7384 }
7385 
7386 #ifdef FEAT_FLOAT
7387     float_T
7388 tv_get_float(typval_T *varp)
7389 {
7390     switch (varp->v_type)
7391     {
7392 	case VAR_NUMBER:
7393 	    return (float_T)(varp->vval.v_number);
7394 	case VAR_FLOAT:
7395 	    return varp->vval.v_float;
7396 	case VAR_FUNC:
7397 	case VAR_PARTIAL:
7398 	    emsg(_("E891: Using a Funcref as a Float"));
7399 	    break;
7400 	case VAR_STRING:
7401 	    emsg(_("E892: Using a String as a Float"));
7402 	    break;
7403 	case VAR_LIST:
7404 	    emsg(_("E893: Using a List as a Float"));
7405 	    break;
7406 	case VAR_DICT:
7407 	    emsg(_("E894: Using a Dictionary as a Float"));
7408 	    break;
7409 	case VAR_SPECIAL:
7410 	    emsg(_("E907: Using a special value as a Float"));
7411 	    break;
7412 	case VAR_JOB:
7413 # ifdef FEAT_JOB_CHANNEL
7414 	    emsg(_("E911: Using a Job as a Float"));
7415 	    break;
7416 # endif
7417 	case VAR_CHANNEL:
7418 # ifdef FEAT_JOB_CHANNEL
7419 	    emsg(_("E914: Using a Channel as a Float"));
7420 	    break;
7421 # endif
7422 	case VAR_BLOB:
7423 	    emsg(_("E975: Using a Blob as a Float"));
7424 	    break;
7425 	case VAR_UNKNOWN:
7426 	    internal_error("tv_get_float(UNKNOWN)");
7427 	    break;
7428     }
7429     return 0;
7430 }
7431 #endif
7432 
7433 /*
7434  * Get the string value of a variable.
7435  * If it is a Number variable, the number is converted into a string.
7436  * tv_get_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7437  * tv_get_string_buf() uses a given buffer.
7438  * If the String variable has never been set, return an empty string.
7439  * Never returns NULL;
7440  * tv_get_string_chk() and tv_get_string_buf_chk() are similar, but return
7441  * NULL on error.
7442  */
7443     char_u *
7444 tv_get_string(typval_T *varp)
7445 {
7446     static char_u   mybuf[NUMBUFLEN];
7447 
7448     return tv_get_string_buf(varp, mybuf);
7449 }
7450 
7451     char_u *
7452 tv_get_string_buf(typval_T *varp, char_u *buf)
7453 {
7454     char_u	*res =  tv_get_string_buf_chk(varp, buf);
7455 
7456     return res != NULL ? res : (char_u *)"";
7457 }
7458 
7459 /*
7460  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7461  */
7462     char_u *
7463 tv_get_string_chk(typval_T *varp)
7464 {
7465     static char_u   mybuf[NUMBUFLEN];
7466 
7467     return tv_get_string_buf_chk(varp, mybuf);
7468 }
7469 
7470     char_u *
7471 tv_get_string_buf_chk(typval_T *varp, char_u *buf)
7472 {
7473     switch (varp->v_type)
7474     {
7475 	case VAR_NUMBER:
7476 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
7477 					    (long_long_T)varp->vval.v_number);
7478 	    return buf;
7479 	case VAR_FUNC:
7480 	case VAR_PARTIAL:
7481 	    emsg(_("E729: using Funcref as a String"));
7482 	    break;
7483 	case VAR_LIST:
7484 	    emsg(_("E730: using List as a String"));
7485 	    break;
7486 	case VAR_DICT:
7487 	    emsg(_("E731: using Dictionary as a String"));
7488 	    break;
7489 	case VAR_FLOAT:
7490 #ifdef FEAT_FLOAT
7491 	    emsg(_(e_float_as_string));
7492 	    break;
7493 #endif
7494 	case VAR_STRING:
7495 	    if (varp->vval.v_string != NULL)
7496 		return varp->vval.v_string;
7497 	    return (char_u *)"";
7498 	case VAR_SPECIAL:
7499 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
7500 	    return buf;
7501         case VAR_BLOB:
7502 	    emsg(_("E976: using Blob as a String"));
7503 	    break;
7504 	case VAR_JOB:
7505 #ifdef FEAT_JOB_CHANNEL
7506 	    {
7507 		job_T *job = varp->vval.v_job;
7508 		char  *status;
7509 
7510 		if (job == NULL)
7511 		    return (char_u *)"no process";
7512 		status = job->jv_status == JOB_FAILED ? "fail"
7513 				: job->jv_status >= JOB_ENDED ? "dead"
7514 				: "run";
7515 # ifdef UNIX
7516 		vim_snprintf((char *)buf, NUMBUFLEN,
7517 			    "process %ld %s", (long)job->jv_pid, status);
7518 # elif defined(MSWIN)
7519 		vim_snprintf((char *)buf, NUMBUFLEN,
7520 			    "process %ld %s",
7521 			    (long)job->jv_proc_info.dwProcessId,
7522 			    status);
7523 # else
7524 		/* fall-back */
7525 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
7526 # endif
7527 		return buf;
7528 	    }
7529 #endif
7530 	    break;
7531 	case VAR_CHANNEL:
7532 #ifdef FEAT_JOB_CHANNEL
7533 	    {
7534 		channel_T *channel = varp->vval.v_channel;
7535 		char      *status = channel_status(channel, -1);
7536 
7537 		if (channel == NULL)
7538 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
7539 		else
7540 		    vim_snprintf((char *)buf, NUMBUFLEN,
7541 				     "channel %d %s", channel->ch_id, status);
7542 		return buf;
7543 	    }
7544 #endif
7545 	    break;
7546 	case VAR_UNKNOWN:
7547 	    emsg(_("E908: using an invalid value as a String"));
7548 	    break;
7549     }
7550     return NULL;
7551 }
7552 
7553 /*
7554  * Turn a typeval into a string.  Similar to tv_get_string_buf() but uses
7555  * string() on Dict, List, etc.
7556  */
7557     char_u *
7558 tv_stringify(typval_T *varp, char_u *buf)
7559 {
7560     if (varp->v_type == VAR_LIST
7561 	    || varp->v_type == VAR_DICT
7562 	    || varp->v_type == VAR_FUNC
7563 	    || varp->v_type == VAR_PARTIAL
7564 	    || varp->v_type == VAR_FLOAT)
7565     {
7566 	typval_T tmp;
7567 
7568 	f_string(varp, &tmp);
7569 	tv_get_string_buf(&tmp, buf);
7570 	clear_tv(varp);
7571 	*varp = tmp;
7572 	return tmp.vval.v_string;
7573     }
7574     return tv_get_string_buf(varp, buf);
7575 }
7576 
7577 /*
7578  * Find variable "name" in the list of variables.
7579  * Return a pointer to it if found, NULL if not found.
7580  * Careful: "a:0" variables don't have a name.
7581  * When "htp" is not NULL we are writing to the variable, set "htp" to the
7582  * hashtab_T used.
7583  */
7584     dictitem_T *
7585 find_var(char_u *name, hashtab_T **htp, int no_autoload)
7586 {
7587     char_u	*varname;
7588     hashtab_T	*ht;
7589     dictitem_T	*ret = NULL;
7590 
7591     ht = find_var_ht(name, &varname);
7592     if (htp != NULL)
7593 	*htp = ht;
7594     if (ht == NULL)
7595 	return NULL;
7596     ret = find_var_in_ht(ht, *name, varname, no_autoload || htp != NULL);
7597     if (ret != NULL)
7598 	return ret;
7599 
7600     /* Search in parent scope for lambda */
7601     return find_var_in_scoped_ht(name, no_autoload || htp != NULL);
7602 }
7603 
7604 /*
7605  * Find variable "varname" in hashtab "ht" with name "htname".
7606  * Returns NULL if not found.
7607  */
7608     dictitem_T *
7609 find_var_in_ht(
7610     hashtab_T	*ht,
7611     int		htname,
7612     char_u	*varname,
7613     int		no_autoload)
7614 {
7615     hashitem_T	*hi;
7616 
7617     if (*varname == NUL)
7618     {
7619 	/* Must be something like "s:", otherwise "ht" would be NULL. */
7620 	switch (htname)
7621 	{
7622 	    case 's': return &SCRIPT_SV(current_sctx.sc_sid)->sv_var;
7623 	    case 'g': return &globvars_var;
7624 	    case 'v': return &vimvars_var;
7625 	    case 'b': return &curbuf->b_bufvar;
7626 	    case 'w': return &curwin->w_winvar;
7627 	    case 't': return &curtab->tp_winvar;
7628 	    case 'l': return get_funccal_local_var();
7629 	    case 'a': return get_funccal_args_var();
7630 	}
7631 	return NULL;
7632     }
7633 
7634     hi = hash_find(ht, varname);
7635     if (HASHITEM_EMPTY(hi))
7636     {
7637 	/* For global variables we may try auto-loading the script.  If it
7638 	 * worked find the variable again.  Don't auto-load a script if it was
7639 	 * loaded already, otherwise it would be loaded every time when
7640 	 * checking if a function name is a Funcref variable. */
7641 	if (ht == &globvarht && !no_autoload)
7642 	{
7643 	    /* Note: script_autoload() may make "hi" invalid. It must either
7644 	     * be obtained again or not used. */
7645 	    if (!script_autoload(varname, FALSE) || aborting())
7646 		return NULL;
7647 	    hi = hash_find(ht, varname);
7648 	}
7649 	if (HASHITEM_EMPTY(hi))
7650 	    return NULL;
7651     }
7652     return HI2DI(hi);
7653 }
7654 
7655 /*
7656  * Find the hashtab used for a variable name.
7657  * Return NULL if the name is not valid.
7658  * Set "varname" to the start of name without ':'.
7659  */
7660     hashtab_T *
7661 find_var_ht(char_u *name, char_u **varname)
7662 {
7663     hashitem_T	*hi;
7664     hashtab_T	*ht;
7665 
7666     if (name[0] == NUL)
7667 	return NULL;
7668     if (name[1] != ':')
7669     {
7670 	/* The name must not start with a colon or #. */
7671 	if (name[0] == ':' || name[0] == AUTOLOAD_CHAR)
7672 	    return NULL;
7673 	*varname = name;
7674 
7675 	// "version" is "v:version" in all scopes if scriptversion < 3.
7676 	// Same for a few other variables marked with VV_COMPAT.
7677 	if (current_sctx.sc_version < 3)
7678 	{
7679 	    hi = hash_find(&compat_hashtab, name);
7680 	    if (!HASHITEM_EMPTY(hi))
7681 		return &compat_hashtab;
7682 	}
7683 
7684 	ht = get_funccal_local_ht();
7685 	if (ht == NULL)
7686 	    return &globvarht;			/* global variable */
7687 	return ht;				/* local variable */
7688     }
7689     *varname = name + 2;
7690     if (*name == 'g')				/* global variable */
7691 	return &globvarht;
7692     /* There must be no ':' or '#' in the rest of the name, unless g: is used
7693      */
7694     if (vim_strchr(name + 2, ':') != NULL
7695 			       || vim_strchr(name + 2, AUTOLOAD_CHAR) != NULL)
7696 	return NULL;
7697     if (*name == 'b')				/* buffer variable */
7698 	return &curbuf->b_vars->dv_hashtab;
7699     if (*name == 'w')				/* window variable */
7700 	return &curwin->w_vars->dv_hashtab;
7701     if (*name == 't')				/* tab page variable */
7702 	return &curtab->tp_vars->dv_hashtab;
7703     if (*name == 'v')				/* v: variable */
7704 	return &vimvarht;
7705     if (*name == 'a')				/* a: function argument */
7706 	return get_funccal_args_ht();
7707     if (*name == 'l')				/* l: local function variable */
7708 	return get_funccal_local_ht();
7709     if (*name == 's'				/* script variable */
7710 	    && current_sctx.sc_sid > 0 && current_sctx.sc_sid <= ga_scripts.ga_len)
7711 	return &SCRIPT_VARS(current_sctx.sc_sid);
7712     return NULL;
7713 }
7714 
7715 /*
7716  * Get the string value of a (global/local) variable.
7717  * Note: see tv_get_string() for how long the pointer remains valid.
7718  * Returns NULL when it doesn't exist.
7719  */
7720     char_u *
7721 get_var_value(char_u *name)
7722 {
7723     dictitem_T	*v;
7724 
7725     v = find_var(name, NULL, FALSE);
7726     if (v == NULL)
7727 	return NULL;
7728     return tv_get_string(&v->di_tv);
7729 }
7730 
7731 /*
7732  * Allocate a new hashtab for a sourced script.  It will be used while
7733  * sourcing this script and when executing functions defined in the script.
7734  */
7735     void
7736 new_script_vars(scid_T id)
7737 {
7738     int		i;
7739     hashtab_T	*ht;
7740     scriptvar_T *sv;
7741 
7742     if (ga_grow(&ga_scripts, (int)(id - ga_scripts.ga_len)) == OK)
7743     {
7744 	/* Re-allocating ga_data means that an ht_array pointing to
7745 	 * ht_smallarray becomes invalid.  We can recognize this: ht_mask is
7746 	 * at its init value.  Also reset "v_dict", it's always the same. */
7747 	for (i = 1; i <= ga_scripts.ga_len; ++i)
7748 	{
7749 	    ht = &SCRIPT_VARS(i);
7750 	    if (ht->ht_mask == HT_INIT_SIZE - 1)
7751 		ht->ht_array = ht->ht_smallarray;
7752 	    sv = SCRIPT_SV(i);
7753 	    sv->sv_var.di_tv.vval.v_dict = &sv->sv_dict;
7754 	}
7755 
7756 	while (ga_scripts.ga_len < id)
7757 	{
7758 	    sv = SCRIPT_SV(ga_scripts.ga_len + 1) =
7759 		(scriptvar_T *)alloc_clear(sizeof(scriptvar_T));
7760 	    init_var_dict(&sv->sv_dict, &sv->sv_var, VAR_SCOPE);
7761 	    ++ga_scripts.ga_len;
7762 	}
7763     }
7764 }
7765 
7766 /*
7767  * Initialize dictionary "dict" as a scope and set variable "dict_var" to
7768  * point to it.
7769  */
7770     void
7771 init_var_dict(dict_T *dict, dictitem_T *dict_var, int scope)
7772 {
7773     hash_init(&dict->dv_hashtab);
7774     dict->dv_lock = 0;
7775     dict->dv_scope = scope;
7776     dict->dv_refcount = DO_NOT_FREE_CNT;
7777     dict->dv_copyID = 0;
7778     dict_var->di_tv.vval.v_dict = dict;
7779     dict_var->di_tv.v_type = VAR_DICT;
7780     dict_var->di_tv.v_lock = VAR_FIXED;
7781     dict_var->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
7782     dict_var->di_key[0] = NUL;
7783 }
7784 
7785 /*
7786  * Unreference a dictionary initialized by init_var_dict().
7787  */
7788     void
7789 unref_var_dict(dict_T *dict)
7790 {
7791     /* Now the dict needs to be freed if no one else is using it, go back to
7792      * normal reference counting. */
7793     dict->dv_refcount -= DO_NOT_FREE_CNT - 1;
7794     dict_unref(dict);
7795 }
7796 
7797 /*
7798  * Clean up a list of internal variables.
7799  * Frees all allocated variables and the value they contain.
7800  * Clears hashtab "ht", does not free it.
7801  */
7802     void
7803 vars_clear(hashtab_T *ht)
7804 {
7805     vars_clear_ext(ht, TRUE);
7806 }
7807 
7808 /*
7809  * Like vars_clear(), but only free the value if "free_val" is TRUE.
7810  */
7811     void
7812 vars_clear_ext(hashtab_T *ht, int free_val)
7813 {
7814     int		todo;
7815     hashitem_T	*hi;
7816     dictitem_T	*v;
7817 
7818     hash_lock(ht);
7819     todo = (int)ht->ht_used;
7820     for (hi = ht->ht_array; todo > 0; ++hi)
7821     {
7822 	if (!HASHITEM_EMPTY(hi))
7823 	{
7824 	    --todo;
7825 
7826 	    /* Free the variable.  Don't remove it from the hashtab,
7827 	     * ht_array might change then.  hash_clear() takes care of it
7828 	     * later. */
7829 	    v = HI2DI(hi);
7830 	    if (free_val)
7831 		clear_tv(&v->di_tv);
7832 	    if (v->di_flags & DI_FLAGS_ALLOC)
7833 		vim_free(v);
7834 	}
7835     }
7836     hash_clear(ht);
7837     ht->ht_used = 0;
7838 }
7839 
7840 /*
7841  * Delete a variable from hashtab "ht" at item "hi".
7842  * Clear the variable value and free the dictitem.
7843  */
7844     static void
7845 delete_var(hashtab_T *ht, hashitem_T *hi)
7846 {
7847     dictitem_T	*di = HI2DI(hi);
7848 
7849     hash_remove(ht, hi);
7850     clear_tv(&di->di_tv);
7851     vim_free(di);
7852 }
7853 
7854 /*
7855  * List the value of one internal variable.
7856  */
7857     static void
7858 list_one_var(dictitem_T *v, char *prefix, int *first)
7859 {
7860     char_u	*tofree;
7861     char_u	*s;
7862     char_u	numbuf[NUMBUFLEN];
7863 
7864     s = echo_string(&v->di_tv, &tofree, numbuf, get_copyID());
7865     list_one_var_a(prefix, v->di_key, v->di_tv.v_type,
7866 					 s == NULL ? (char_u *)"" : s, first);
7867     vim_free(tofree);
7868 }
7869 
7870     static void
7871 list_one_var_a(
7872     char	*prefix,
7873     char_u	*name,
7874     int		type,
7875     char_u	*string,
7876     int		*first)  /* when TRUE clear rest of screen and set to FALSE */
7877 {
7878     /* don't use msg() or msg_attr() to avoid overwriting "v:statusmsg" */
7879     msg_start();
7880     msg_puts(prefix);
7881     if (name != NULL)	/* "a:" vars don't have a name stored */
7882 	msg_puts((char *)name);
7883     msg_putchar(' ');
7884     msg_advance(22);
7885     if (type == VAR_NUMBER)
7886 	msg_putchar('#');
7887     else if (type == VAR_FUNC || type == VAR_PARTIAL)
7888 	msg_putchar('*');
7889     else if (type == VAR_LIST)
7890     {
7891 	msg_putchar('[');
7892 	if (*string == '[')
7893 	    ++string;
7894     }
7895     else if (type == VAR_DICT)
7896     {
7897 	msg_putchar('{');
7898 	if (*string == '{')
7899 	    ++string;
7900     }
7901     else
7902 	msg_putchar(' ');
7903 
7904     msg_outtrans(string);
7905 
7906     if (type == VAR_FUNC || type == VAR_PARTIAL)
7907 	msg_puts("()");
7908     if (*first)
7909     {
7910 	msg_clr_eos();
7911 	*first = FALSE;
7912     }
7913 }
7914 
7915 /*
7916  * Set variable "name" to value in "tv".
7917  * If the variable already exists, the value is updated.
7918  * Otherwise the variable is created.
7919  */
7920     void
7921 set_var(
7922     char_u	*name,
7923     typval_T	*tv,
7924     int		copy)	    /* make copy of value in "tv" */
7925 {
7926     dictitem_T	*v;
7927     char_u	*varname;
7928     hashtab_T	*ht;
7929 
7930     ht = find_var_ht(name, &varname);
7931     if (ht == NULL || *varname == NUL)
7932     {
7933 	semsg(_(e_illvar), name);
7934 	return;
7935     }
7936     v = find_var_in_ht(ht, 0, varname, TRUE);
7937 
7938     /* Search in parent scope which is possible to reference from lambda */
7939     if (v == NULL)
7940 	v = find_var_in_scoped_ht(name, TRUE);
7941 
7942     if ((tv->v_type == VAR_FUNC || tv->v_type == VAR_PARTIAL)
7943 				      && var_check_func_name(name, v == NULL))
7944 	return;
7945 
7946     if (v != NULL)
7947     {
7948 	/* existing variable, need to clear the value */
7949 	if (var_check_ro(v->di_flags, name, FALSE)
7950 			      || var_check_lock(v->di_tv.v_lock, name, FALSE))
7951 	    return;
7952 
7953 	/*
7954 	 * Handle setting internal v: variables separately where needed to
7955 	 * prevent changing the type.
7956 	 */
7957 	if (ht == &vimvarht)
7958 	{
7959 	    if (v->di_tv.v_type == VAR_STRING)
7960 	    {
7961 		VIM_CLEAR(v->di_tv.vval.v_string);
7962 		if (copy || tv->v_type != VAR_STRING)
7963 		{
7964 		    char_u *val = tv_get_string(tv);
7965 
7966 		    // Careful: when assigning to v:errmsg and tv_get_string()
7967 		    // causes an error message the variable will alrady be set.
7968 		    if (v->di_tv.vval.v_string == NULL)
7969 			v->di_tv.vval.v_string = vim_strsave(val);
7970 		}
7971 		else
7972 		{
7973 		    /* Take over the string to avoid an extra alloc/free. */
7974 		    v->di_tv.vval.v_string = tv->vval.v_string;
7975 		    tv->vval.v_string = NULL;
7976 		}
7977 		return;
7978 	    }
7979 	    else if (v->di_tv.v_type == VAR_NUMBER)
7980 	    {
7981 		v->di_tv.vval.v_number = tv_get_number(tv);
7982 		if (STRCMP(varname, "searchforward") == 0)
7983 		    set_search_direction(v->di_tv.vval.v_number ? '/' : '?');
7984 #ifdef FEAT_SEARCH_EXTRA
7985 		else if (STRCMP(varname, "hlsearch") == 0)
7986 		{
7987 		    no_hlsearch = !v->di_tv.vval.v_number;
7988 		    redraw_all_later(SOME_VALID);
7989 		}
7990 #endif
7991 		return;
7992 	    }
7993 	    else if (v->di_tv.v_type != tv->v_type)
7994 	    {
7995 		semsg(_("E963: setting %s to value with wrong type"), name);
7996 		return;
7997 	    }
7998 	}
7999 
8000 	clear_tv(&v->di_tv);
8001     }
8002     else		    /* add a new variable */
8003     {
8004 	// Can't add "v:" or "a:" variable.
8005 	if (ht == &vimvarht || ht == get_funccal_args_ht())
8006 	{
8007 	    semsg(_(e_illvar), name);
8008 	    return;
8009 	}
8010 
8011 	// Make sure the variable name is valid.
8012 	if (!valid_varname(varname))
8013 	    return;
8014 
8015 	v = (dictitem_T *)alloc((unsigned)(sizeof(dictitem_T)
8016 							  + STRLEN(varname)));
8017 	if (v == NULL)
8018 	    return;
8019 	STRCPY(v->di_key, varname);
8020 	if (hash_add(ht, DI2HIKEY(v)) == FAIL)
8021 	{
8022 	    vim_free(v);
8023 	    return;
8024 	}
8025 	v->di_flags = DI_FLAGS_ALLOC;
8026     }
8027 
8028     if (copy || tv->v_type == VAR_NUMBER || tv->v_type == VAR_FLOAT)
8029 	copy_tv(tv, &v->di_tv);
8030     else
8031     {
8032 	v->di_tv = *tv;
8033 	v->di_tv.v_lock = 0;
8034 	init_tv(tv);
8035     }
8036 }
8037 
8038 /*
8039  * Return TRUE if di_flags "flags" indicates variable "name" is read-only.
8040  * Also give an error message.
8041  */
8042     int
8043 var_check_ro(int flags, char_u *name, int use_gettext)
8044 {
8045     if (flags & DI_FLAGS_RO)
8046     {
8047 	semsg(_(e_readonlyvar), use_gettext ? (char_u *)_(name) : name);
8048 	return TRUE;
8049     }
8050     if ((flags & DI_FLAGS_RO_SBX) && sandbox)
8051     {
8052 	semsg(_(e_readonlysbx), use_gettext ? (char_u *)_(name) : name);
8053 	return TRUE;
8054     }
8055     return FALSE;
8056 }
8057 
8058 /*
8059  * Return TRUE if di_flags "flags" indicates variable "name" is fixed.
8060  * Also give an error message.
8061  */
8062     int
8063 var_check_fixed(int flags, char_u *name, int use_gettext)
8064 {
8065     if (flags & DI_FLAGS_FIX)
8066     {
8067 	semsg(_("E795: Cannot delete variable %s"),
8068 				      use_gettext ? (char_u *)_(name) : name);
8069 	return TRUE;
8070     }
8071     return FALSE;
8072 }
8073 
8074 /*
8075  * Check if a funcref is assigned to a valid variable name.
8076  * Return TRUE and give an error if not.
8077  */
8078     int
8079 var_check_func_name(
8080     char_u *name,    /* points to start of variable name */
8081     int    new_var)  /* TRUE when creating the variable */
8082 {
8083     /* Allow for w: b: s: and t:. */
8084     if (!(vim_strchr((char_u *)"wbst", name[0]) != NULL && name[1] == ':')
8085 	    && !ASCII_ISUPPER((name[0] != NUL && name[1] == ':')
8086 						     ? name[2] : name[0]))
8087     {
8088 	semsg(_("E704: Funcref variable name must start with a capital: %s"),
8089 									name);
8090 	return TRUE;
8091     }
8092     /* Don't allow hiding a function.  When "v" is not NULL we might be
8093      * assigning another function to the same var, the type is checked
8094      * below. */
8095     if (new_var && function_exists(name, FALSE))
8096     {
8097 	semsg(_("E705: Variable name conflicts with existing function: %s"),
8098 								    name);
8099 	return TRUE;
8100     }
8101     return FALSE;
8102 }
8103 
8104 /*
8105  * Return TRUE if "flags" indicates variable "name" is locked (immutable).
8106  * Also give an error message, using "name" or _("name") when use_gettext is
8107  * TRUE.
8108  */
8109     int
8110 var_check_lock(int lock, char_u *name, int use_gettext)
8111 {
8112     if (lock & VAR_LOCKED)
8113     {
8114 	semsg(_("E741: Value is locked: %s"),
8115 				name == NULL ? (char_u *)_("Unknown")
8116 					     : use_gettext ? (char_u *)_(name)
8117 					     : name);
8118 	return TRUE;
8119     }
8120     if (lock & VAR_FIXED)
8121     {
8122 	semsg(_("E742: Cannot change value of %s"),
8123 				name == NULL ? (char_u *)_("Unknown")
8124 					     : use_gettext ? (char_u *)_(name)
8125 					     : name);
8126 	return TRUE;
8127     }
8128     return FALSE;
8129 }
8130 
8131 /*
8132  * Return TRUE if typeval "tv" and its value are set to be locked (immutable).
8133  * Also give an error message, using "name" or _("name") when use_gettext is
8134  * TRUE.
8135  */
8136     static int
8137 tv_check_lock(typval_T *tv, char_u *name, int use_gettext)
8138 {
8139     int	lock = 0;
8140 
8141     switch (tv->v_type)
8142     {
8143 	case VAR_BLOB:
8144 	    if (tv->vval.v_blob != NULL)
8145 		lock = tv->vval.v_blob->bv_lock;
8146 	    break;
8147 	case VAR_LIST:
8148 	    if (tv->vval.v_list != NULL)
8149 		lock = tv->vval.v_list->lv_lock;
8150 	    break;
8151 	case VAR_DICT:
8152 	    if (tv->vval.v_dict != NULL)
8153 		lock = tv->vval.v_dict->dv_lock;
8154 	    break;
8155 	default:
8156 	    break;
8157     }
8158     return var_check_lock(tv->v_lock, name, use_gettext)
8159 		    || (lock != 0 && var_check_lock(lock, name, use_gettext));
8160 }
8161 
8162 /*
8163  * Check if a variable name is valid.
8164  * Return FALSE and give an error if not.
8165  */
8166     int
8167 valid_varname(char_u *varname)
8168 {
8169     char_u *p;
8170 
8171     for (p = varname; *p != NUL; ++p)
8172 	if (!eval_isnamec1(*p) && (p == varname || !VIM_ISDIGIT(*p))
8173 						   && *p != AUTOLOAD_CHAR)
8174 	{
8175 	    semsg(_(e_illvar), varname);
8176 	    return FALSE;
8177 	}
8178     return TRUE;
8179 }
8180 
8181 /*
8182  * Copy the values from typval_T "from" to typval_T "to".
8183  * When needed allocates string or increases reference count.
8184  * Does not make a copy of a list, blob or dict but copies the reference!
8185  * It is OK for "from" and "to" to point to the same item.  This is used to
8186  * make a copy later.
8187  */
8188     void
8189 copy_tv(typval_T *from, typval_T *to)
8190 {
8191     to->v_type = from->v_type;
8192     to->v_lock = 0;
8193     switch (from->v_type)
8194     {
8195 	case VAR_NUMBER:
8196 	case VAR_SPECIAL:
8197 	    to->vval.v_number = from->vval.v_number;
8198 	    break;
8199 	case VAR_FLOAT:
8200 #ifdef FEAT_FLOAT
8201 	    to->vval.v_float = from->vval.v_float;
8202 	    break;
8203 #endif
8204 	case VAR_JOB:
8205 #ifdef FEAT_JOB_CHANNEL
8206 	    to->vval.v_job = from->vval.v_job;
8207 	    if (to->vval.v_job != NULL)
8208 		++to->vval.v_job->jv_refcount;
8209 	    break;
8210 #endif
8211 	case VAR_CHANNEL:
8212 #ifdef FEAT_JOB_CHANNEL
8213 	    to->vval.v_channel = from->vval.v_channel;
8214 	    if (to->vval.v_channel != NULL)
8215 		++to->vval.v_channel->ch_refcount;
8216 	    break;
8217 #endif
8218 	case VAR_STRING:
8219 	case VAR_FUNC:
8220 	    if (from->vval.v_string == NULL)
8221 		to->vval.v_string = NULL;
8222 	    else
8223 	    {
8224 		to->vval.v_string = vim_strsave(from->vval.v_string);
8225 		if (from->v_type == VAR_FUNC)
8226 		    func_ref(to->vval.v_string);
8227 	    }
8228 	    break;
8229 	case VAR_PARTIAL:
8230 	    if (from->vval.v_partial == NULL)
8231 		to->vval.v_partial = NULL;
8232 	    else
8233 	    {
8234 		to->vval.v_partial = from->vval.v_partial;
8235 		++to->vval.v_partial->pt_refcount;
8236 	    }
8237 	    break;
8238 	case VAR_BLOB:
8239 	    if (from->vval.v_blob == NULL)
8240 		to->vval.v_blob = NULL;
8241 	    else
8242 	    {
8243 		to->vval.v_blob = from->vval.v_blob;
8244 		++to->vval.v_blob->bv_refcount;
8245 	    }
8246 	    break;
8247 	case VAR_LIST:
8248 	    if (from->vval.v_list == NULL)
8249 		to->vval.v_list = NULL;
8250 	    else
8251 	    {
8252 		to->vval.v_list = from->vval.v_list;
8253 		++to->vval.v_list->lv_refcount;
8254 	    }
8255 	    break;
8256 	case VAR_DICT:
8257 	    if (from->vval.v_dict == NULL)
8258 		to->vval.v_dict = NULL;
8259 	    else
8260 	    {
8261 		to->vval.v_dict = from->vval.v_dict;
8262 		++to->vval.v_dict->dv_refcount;
8263 	    }
8264 	    break;
8265 	case VAR_UNKNOWN:
8266 	    internal_error("copy_tv(UNKNOWN)");
8267 	    break;
8268     }
8269 }
8270 
8271 /*
8272  * Make a copy of an item.
8273  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
8274  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
8275  * reference to an already copied list/dict can be used.
8276  * Returns FAIL or OK.
8277  */
8278     int
8279 item_copy(
8280     typval_T	*from,
8281     typval_T	*to,
8282     int		deep,
8283     int		copyID)
8284 {
8285     static int	recurse = 0;
8286     int		ret = OK;
8287 
8288     if (recurse >= DICT_MAXNEST)
8289     {
8290 	emsg(_("E698: variable nested too deep for making a copy"));
8291 	return FAIL;
8292     }
8293     ++recurse;
8294 
8295     switch (from->v_type)
8296     {
8297 	case VAR_NUMBER:
8298 	case VAR_FLOAT:
8299 	case VAR_STRING:
8300 	case VAR_FUNC:
8301 	case VAR_PARTIAL:
8302 	case VAR_SPECIAL:
8303 	case VAR_JOB:
8304 	case VAR_CHANNEL:
8305 	    copy_tv(from, to);
8306 	    break;
8307 	case VAR_LIST:
8308 	    to->v_type = VAR_LIST;
8309 	    to->v_lock = 0;
8310 	    if (from->vval.v_list == NULL)
8311 		to->vval.v_list = NULL;
8312 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
8313 	    {
8314 		/* use the copy made earlier */
8315 		to->vval.v_list = from->vval.v_list->lv_copylist;
8316 		++to->vval.v_list->lv_refcount;
8317 	    }
8318 	    else
8319 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
8320 	    if (to->vval.v_list == NULL)
8321 		ret = FAIL;
8322 	    break;
8323 	case VAR_BLOB:
8324 	    ret = blob_copy(from, to);
8325 	    break;
8326 	case VAR_DICT:
8327 	    to->v_type = VAR_DICT;
8328 	    to->v_lock = 0;
8329 	    if (from->vval.v_dict == NULL)
8330 		to->vval.v_dict = NULL;
8331 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
8332 	    {
8333 		/* use the copy made earlier */
8334 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
8335 		++to->vval.v_dict->dv_refcount;
8336 	    }
8337 	    else
8338 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
8339 	    if (to->vval.v_dict == NULL)
8340 		ret = FAIL;
8341 	    break;
8342 	case VAR_UNKNOWN:
8343 	    internal_error("item_copy(UNKNOWN)");
8344 	    ret = FAIL;
8345     }
8346     --recurse;
8347     return ret;
8348 }
8349 
8350 /*
8351  * This function is used by f_input() and f_inputdialog() functions. The third
8352  * argument to f_input() specifies the type of completion to use at the
8353  * prompt. The third argument to f_inputdialog() specifies the value to return
8354  * when the user cancels the prompt.
8355  */
8356     void
8357 get_user_input(
8358     typval_T	*argvars,
8359     typval_T	*rettv,
8360     int		inputdialog,
8361     int		secret)
8362 {
8363     char_u	*prompt = tv_get_string_chk(&argvars[0]);
8364     char_u	*p = NULL;
8365     int		c;
8366     char_u	buf[NUMBUFLEN];
8367     int		cmd_silent_save = cmd_silent;
8368     char_u	*defstr = (char_u *)"";
8369     int		xp_type = EXPAND_NOTHING;
8370     char_u	*xp_arg = NULL;
8371 
8372     rettv->v_type = VAR_STRING;
8373     rettv->vval.v_string = NULL;
8374 
8375 #ifdef NO_CONSOLE_INPUT
8376     /* While starting up, there is no place to enter text. When running tests
8377      * with --not-a-term we assume feedkeys() will be used. */
8378     if (no_console_input() && !is_not_a_term())
8379 	return;
8380 #endif
8381 
8382     cmd_silent = FALSE;		/* Want to see the prompt. */
8383     if (prompt != NULL)
8384     {
8385 	/* Only the part of the message after the last NL is considered as
8386 	 * prompt for the command line */
8387 	p = vim_strrchr(prompt, '\n');
8388 	if (p == NULL)
8389 	    p = prompt;
8390 	else
8391 	{
8392 	    ++p;
8393 	    c = *p;
8394 	    *p = NUL;
8395 	    msg_start();
8396 	    msg_clr_eos();
8397 	    msg_puts_attr((char *)prompt, echo_attr);
8398 	    msg_didout = FALSE;
8399 	    msg_starthere();
8400 	    *p = c;
8401 	}
8402 	cmdline_row = msg_row;
8403 
8404 	if (argvars[1].v_type != VAR_UNKNOWN)
8405 	{
8406 	    defstr = tv_get_string_buf_chk(&argvars[1], buf);
8407 	    if (defstr != NULL)
8408 		stuffReadbuffSpec(defstr);
8409 
8410 	    if (!inputdialog && argvars[2].v_type != VAR_UNKNOWN)
8411 	    {
8412 		char_u	*xp_name;
8413 		int	xp_namelen;
8414 		long	argt;
8415 
8416 		/* input() with a third argument: completion */
8417 		rettv->vval.v_string = NULL;
8418 
8419 		xp_name = tv_get_string_buf_chk(&argvars[2], buf);
8420 		if (xp_name == NULL)
8421 		    return;
8422 
8423 		xp_namelen = (int)STRLEN(xp_name);
8424 
8425 		if (parse_compl_arg(xp_name, xp_namelen, &xp_type, &argt,
8426 							     &xp_arg) == FAIL)
8427 		    return;
8428 	    }
8429 	}
8430 
8431 	if (defstr != NULL)
8432 	{
8433 	    int save_ex_normal_busy = ex_normal_busy;
8434 
8435 	    ex_normal_busy = 0;
8436 	    rettv->vval.v_string =
8437 		getcmdline_prompt(secret ? NUL : '@', p, echo_attr,
8438 							      xp_type, xp_arg);
8439 	    ex_normal_busy = save_ex_normal_busy;
8440 	}
8441 	if (inputdialog && rettv->vval.v_string == NULL
8442 		&& argvars[1].v_type != VAR_UNKNOWN
8443 		&& argvars[2].v_type != VAR_UNKNOWN)
8444 	    rettv->vval.v_string = vim_strsave(tv_get_string_buf(
8445 							   &argvars[2], buf));
8446 
8447 	vim_free(xp_arg);
8448 
8449 	/* since the user typed this, no need to wait for return */
8450 	need_wait_return = FALSE;
8451 	msg_didout = FALSE;
8452     }
8453     cmd_silent = cmd_silent_save;
8454 }
8455 
8456 /*
8457  * ":echo expr1 ..."	print each argument separated with a space, add a
8458  *			newline at the end.
8459  * ":echon expr1 ..."	print each argument plain.
8460  */
8461     void
8462 ex_echo(exarg_T *eap)
8463 {
8464     char_u	*arg = eap->arg;
8465     typval_T	rettv;
8466     char_u	*tofree;
8467     char_u	*p;
8468     int		needclr = TRUE;
8469     int		atstart = TRUE;
8470     char_u	numbuf[NUMBUFLEN];
8471     int		did_emsg_before = did_emsg;
8472     int		called_emsg_before = called_emsg;
8473 
8474     if (eap->skip)
8475 	++emsg_skip;
8476     while (*arg != NUL && *arg != '|' && *arg != '\n' && !got_int)
8477     {
8478 	/* If eval1() causes an error message the text from the command may
8479 	 * still need to be cleared. E.g., "echo 22,44". */
8480 	need_clr_eos = needclr;
8481 
8482 	p = arg;
8483 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8484 	{
8485 	    /*
8486 	     * Report the invalid expression unless the expression evaluation
8487 	     * has been cancelled due to an aborting error, an interrupt, or an
8488 	     * exception.
8489 	     */
8490 	    if (!aborting() && did_emsg == did_emsg_before
8491 					  && called_emsg == called_emsg_before)
8492 		semsg(_(e_invexpr2), p);
8493 	    need_clr_eos = FALSE;
8494 	    break;
8495 	}
8496 	need_clr_eos = FALSE;
8497 
8498 	if (!eap->skip)
8499 	{
8500 	    if (atstart)
8501 	    {
8502 		atstart = FALSE;
8503 		/* Call msg_start() after eval1(), evaluating the expression
8504 		 * may cause a message to appear. */
8505 		if (eap->cmdidx == CMD_echo)
8506 		{
8507 		    /* Mark the saved text as finishing the line, so that what
8508 		     * follows is displayed on a new line when scrolling back
8509 		     * at the more prompt. */
8510 		    msg_sb_eol();
8511 		    msg_start();
8512 		}
8513 	    }
8514 	    else if (eap->cmdidx == CMD_echo)
8515 		msg_puts_attr(" ", echo_attr);
8516 	    p = echo_string(&rettv, &tofree, numbuf, get_copyID());
8517 	    if (p != NULL)
8518 		for ( ; *p != NUL && !got_int; ++p)
8519 		{
8520 		    if (*p == '\n' || *p == '\r' || *p == TAB)
8521 		    {
8522 			if (*p != TAB && needclr)
8523 			{
8524 			    /* remove any text still there from the command */
8525 			    msg_clr_eos();
8526 			    needclr = FALSE;
8527 			}
8528 			msg_putchar_attr(*p, echo_attr);
8529 		    }
8530 		    else
8531 		    {
8532 			if (has_mbyte)
8533 			{
8534 			    int i = (*mb_ptr2len)(p);
8535 
8536 			    (void)msg_outtrans_len_attr(p, i, echo_attr);
8537 			    p += i - 1;
8538 			}
8539 			else
8540 			    (void)msg_outtrans_len_attr(p, 1, echo_attr);
8541 		    }
8542 		}
8543 	    vim_free(tofree);
8544 	}
8545 	clear_tv(&rettv);
8546 	arg = skipwhite(arg);
8547     }
8548     eap->nextcmd = check_nextcmd(arg);
8549 
8550     if (eap->skip)
8551 	--emsg_skip;
8552     else
8553     {
8554 	/* remove text that may still be there from the command */
8555 	if (needclr)
8556 	    msg_clr_eos();
8557 	if (eap->cmdidx == CMD_echo)
8558 	    msg_end();
8559     }
8560 }
8561 
8562 /*
8563  * ":echohl {name}".
8564  */
8565     void
8566 ex_echohl(exarg_T *eap)
8567 {
8568     echo_attr = syn_name2attr(eap->arg);
8569 }
8570 
8571 /*
8572  * ":execute expr1 ..."	execute the result of an expression.
8573  * ":echomsg expr1 ..."	Print a message
8574  * ":echoerr expr1 ..."	Print an error
8575  * Each gets spaces around each argument and a newline at the end for
8576  * echo commands
8577  */
8578     void
8579 ex_execute(exarg_T *eap)
8580 {
8581     char_u	*arg = eap->arg;
8582     typval_T	rettv;
8583     int		ret = OK;
8584     char_u	*p;
8585     garray_T	ga;
8586     int		len;
8587     int		save_did_emsg;
8588 
8589     ga_init2(&ga, 1, 80);
8590 
8591     if (eap->skip)
8592 	++emsg_skip;
8593     while (*arg != NUL && *arg != '|' && *arg != '\n')
8594     {
8595 	ret = eval1_emsg(&arg, &rettv, !eap->skip);
8596 	if (ret == FAIL)
8597 	    break;
8598 
8599 	if (!eap->skip)
8600 	{
8601 	    char_u   buf[NUMBUFLEN];
8602 
8603 	    if (eap->cmdidx == CMD_execute)
8604 		p = tv_get_string_buf(&rettv, buf);
8605 	    else
8606 		p = tv_stringify(&rettv, buf);
8607 	    len = (int)STRLEN(p);
8608 	    if (ga_grow(&ga, len + 2) == FAIL)
8609 	    {
8610 		clear_tv(&rettv);
8611 		ret = FAIL;
8612 		break;
8613 	    }
8614 	    if (ga.ga_len)
8615 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
8616 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
8617 	    ga.ga_len += len;
8618 	}
8619 
8620 	clear_tv(&rettv);
8621 	arg = skipwhite(arg);
8622     }
8623 
8624     if (ret != FAIL && ga.ga_data != NULL)
8625     {
8626 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
8627 	{
8628 	    /* Mark the already saved text as finishing the line, so that what
8629 	     * follows is displayed on a new line when scrolling back at the
8630 	     * more prompt. */
8631 	    msg_sb_eol();
8632 	}
8633 
8634 	if (eap->cmdidx == CMD_echomsg)
8635 	{
8636 	    msg_attr(ga.ga_data, echo_attr);
8637 	    out_flush();
8638 	}
8639 	else if (eap->cmdidx == CMD_echoerr)
8640 	{
8641 	    /* We don't want to abort following commands, restore did_emsg. */
8642 	    save_did_emsg = did_emsg;
8643 	    emsg(ga.ga_data);
8644 	    if (!force_abort)
8645 		did_emsg = save_did_emsg;
8646 	}
8647 	else if (eap->cmdidx == CMD_execute)
8648 	    do_cmdline((char_u *)ga.ga_data,
8649 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
8650     }
8651 
8652     ga_clear(&ga);
8653 
8654     if (eap->skip)
8655 	--emsg_skip;
8656 
8657     eap->nextcmd = check_nextcmd(arg);
8658 }
8659 
8660 /*
8661  * Find window specified by "vp" in tabpage "tp".
8662  */
8663     win_T *
8664 find_win_by_nr(
8665     typval_T	*vp,
8666     tabpage_T	*tp)	/* NULL for current tab page */
8667 {
8668     win_T	*wp;
8669     int		nr = (int)tv_get_number_chk(vp, NULL);
8670 
8671     if (nr < 0)
8672 	return NULL;
8673     if (nr == 0)
8674 	return curwin;
8675 
8676     FOR_ALL_WINDOWS_IN_TAB(tp, wp)
8677     {
8678 	if (nr >= LOWEST_WIN_ID)
8679 	{
8680 	    if (wp->w_id == nr)
8681 		return wp;
8682 	}
8683 	else if (--nr <= 0)
8684 	    break;
8685     }
8686     if (nr >= LOWEST_WIN_ID)
8687 	return NULL;
8688     return wp;
8689 }
8690 
8691 /*
8692  * Find a window: When using a Window ID in any tab page, when using a number
8693  * in the current tab page.
8694  */
8695     win_T *
8696 find_win_by_nr_or_id(typval_T *vp)
8697 {
8698     int	nr = (int)tv_get_number_chk(vp, NULL);
8699 
8700     if (nr >= LOWEST_WIN_ID)
8701 	return win_id2wp(tv_get_number(vp));
8702     return find_win_by_nr(vp, NULL);
8703 }
8704 
8705 /*
8706  * Find window specified by "wvp" in tabpage "tvp".
8707  * Returns the tab page in 'ptp'
8708  */
8709     win_T *
8710 find_tabwin(
8711     typval_T	*wvp,	// VAR_UNKNOWN for current window
8712     typval_T	*tvp,	// VAR_UNKNOWN for current tab page
8713     tabpage_T	**ptp)
8714 {
8715     win_T	*wp = NULL;
8716     tabpage_T	*tp = NULL;
8717     long	n;
8718 
8719     if (wvp->v_type != VAR_UNKNOWN)
8720     {
8721 	if (tvp->v_type != VAR_UNKNOWN)
8722 	{
8723 	    n = (long)tv_get_number(tvp);
8724 	    if (n >= 0)
8725 		tp = find_tabpage(n);
8726 	}
8727 	else
8728 	    tp = curtab;
8729 
8730 	if (tp != NULL)
8731 	{
8732 	    wp = find_win_by_nr(wvp, tp);
8733 	    if (wp == NULL && wvp->v_type == VAR_NUMBER
8734 						&& wvp->vval.v_number != -1)
8735 		// A window with the specified number is not found
8736 		tp = NULL;
8737 	}
8738     }
8739     else
8740     {
8741 	wp = curwin;
8742 	tp = curtab;
8743     }
8744 
8745     if (ptp != NULL)
8746 	*ptp = tp;
8747 
8748     return wp;
8749 }
8750 
8751 /*
8752  * getwinvar() and gettabwinvar()
8753  */
8754     void
8755 getwinvar(
8756     typval_T	*argvars,
8757     typval_T	*rettv,
8758     int		off)	    /* 1 for gettabwinvar() */
8759 {
8760     win_T	*win;
8761     char_u	*varname;
8762     dictitem_T	*v;
8763     tabpage_T	*tp = NULL;
8764     int		done = FALSE;
8765     win_T	*oldcurwin;
8766     tabpage_T	*oldtabpage;
8767     int		need_switch_win;
8768 
8769     if (off == 1)
8770 	tp = find_tabpage((int)tv_get_number_chk(&argvars[0], NULL));
8771     else
8772 	tp = curtab;
8773     win = find_win_by_nr(&argvars[off], tp);
8774     varname = tv_get_string_chk(&argvars[off + 1]);
8775     ++emsg_off;
8776 
8777     rettv->v_type = VAR_STRING;
8778     rettv->vval.v_string = NULL;
8779 
8780     if (win != NULL && varname != NULL)
8781     {
8782 	/* Set curwin to be our win, temporarily.  Also set the tabpage,
8783 	 * otherwise the window is not valid. Only do this when needed,
8784 	 * autocommands get blocked. */
8785 	need_switch_win = !(tp == curtab && win == curwin);
8786 	if (!need_switch_win
8787 		  || switch_win(&oldcurwin, &oldtabpage, win, tp, TRUE) == OK)
8788 	{
8789 	    if (*varname == '&')
8790 	    {
8791 		if (varname[1] == NUL)
8792 		{
8793 		    /* get all window-local options in a dict */
8794 		    dict_T	*opts = get_winbuf_options(FALSE);
8795 
8796 		    if (opts != NULL)
8797 		    {
8798 			rettv_dict_set(rettv, opts);
8799 			done = TRUE;
8800 		    }
8801 		}
8802 		else if (get_option_tv(&varname, rettv, 1) == OK)
8803 		    /* window-local-option */
8804 		    done = TRUE;
8805 	    }
8806 	    else
8807 	    {
8808 		/* Look up the variable. */
8809 		/* Let getwinvar({nr}, "") return the "w:" dictionary. */
8810 		v = find_var_in_ht(&win->w_vars->dv_hashtab, 'w',
8811 							      varname, FALSE);
8812 		if (v != NULL)
8813 		{
8814 		    copy_tv(&v->di_tv, rettv);
8815 		    done = TRUE;
8816 		}
8817 	    }
8818 	}
8819 
8820 	if (need_switch_win)
8821 	    /* restore previous notion of curwin */
8822 	    restore_win(oldcurwin, oldtabpage, TRUE);
8823     }
8824 
8825     if (!done && argvars[off + 2].v_type != VAR_UNKNOWN)
8826 	/* use the default return value */
8827 	copy_tv(&argvars[off + 2], rettv);
8828 
8829     --emsg_off;
8830 }
8831 
8832 /*
8833  * "setwinvar()" and "settabwinvar()" functions
8834  */
8835     void
8836 setwinvar(typval_T *argvars, typval_T *rettv UNUSED, int off)
8837 {
8838     win_T	*win;
8839     win_T	*save_curwin;
8840     tabpage_T	*save_curtab;
8841     int		need_switch_win;
8842     char_u	*varname, *winvarname;
8843     typval_T	*varp;
8844     char_u	nbuf[NUMBUFLEN];
8845     tabpage_T	*tp = NULL;
8846 
8847     if (check_secure())
8848 	return;
8849 
8850     if (off == 1)
8851 	tp = find_tabpage((int)tv_get_number_chk(&argvars[0], NULL));
8852     else
8853 	tp = curtab;
8854     win = find_win_by_nr(&argvars[off], tp);
8855     varname = tv_get_string_chk(&argvars[off + 1]);
8856     varp = &argvars[off + 2];
8857 
8858     if (win != NULL && varname != NULL && varp != NULL)
8859     {
8860 	need_switch_win = !(tp == curtab && win == curwin);
8861 	if (!need_switch_win
8862 	       || switch_win(&save_curwin, &save_curtab, win, tp, TRUE) == OK)
8863 	{
8864 	    if (*varname == '&')
8865 	    {
8866 		long	numval;
8867 		char_u	*strval;
8868 		int		error = FALSE;
8869 
8870 		++varname;
8871 		numval = (long)tv_get_number_chk(varp, &error);
8872 		strval = tv_get_string_buf_chk(varp, nbuf);
8873 		if (!error && strval != NULL)
8874 		    set_option_value(varname, numval, strval, OPT_LOCAL);
8875 	    }
8876 	    else
8877 	    {
8878 		winvarname = alloc((unsigned)STRLEN(varname) + 3);
8879 		if (winvarname != NULL)
8880 		{
8881 		    STRCPY(winvarname, "w:");
8882 		    STRCPY(winvarname + 2, varname);
8883 		    set_var(winvarname, varp, TRUE);
8884 		    vim_free(winvarname);
8885 		}
8886 	    }
8887 	}
8888 	if (need_switch_win)
8889 	    restore_win(save_curwin, save_curtab, TRUE);
8890     }
8891 }
8892 
8893 /*
8894  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
8895  * "arg" points to the "&" or '+' when called, to "option" when returning.
8896  * Returns NULL when no option name found.  Otherwise pointer to the char
8897  * after the option name.
8898  */
8899     static char_u *
8900 find_option_end(char_u **arg, int *opt_flags)
8901 {
8902     char_u	*p = *arg;
8903 
8904     ++p;
8905     if (*p == 'g' && p[1] == ':')
8906     {
8907 	*opt_flags = OPT_GLOBAL;
8908 	p += 2;
8909     }
8910     else if (*p == 'l' && p[1] == ':')
8911     {
8912 	*opt_flags = OPT_LOCAL;
8913 	p += 2;
8914     }
8915     else
8916 	*opt_flags = 0;
8917 
8918     if (!ASCII_ISALPHA(*p))
8919 	return NULL;
8920     *arg = p;
8921 
8922     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
8923 	p += 4;	    /* termcap option */
8924     else
8925 	while (ASCII_ISALPHA(*p))
8926 	    ++p;
8927     return p;
8928 }
8929 
8930 /*
8931  * Return the autoload script name for a function or variable name.
8932  * Returns NULL when out of memory.
8933  */
8934     char_u *
8935 autoload_name(char_u *name)
8936 {
8937     char_u	*p;
8938     char_u	*scriptname;
8939 
8940     /* Get the script file name: replace '#' with '/', append ".vim". */
8941     scriptname = alloc((unsigned)(STRLEN(name) + 14));
8942     if (scriptname == NULL)
8943 	return FALSE;
8944     STRCPY(scriptname, "autoload/");
8945     STRCAT(scriptname, name);
8946     *vim_strrchr(scriptname, AUTOLOAD_CHAR) = NUL;
8947     STRCAT(scriptname, ".vim");
8948     while ((p = vim_strchr(scriptname, AUTOLOAD_CHAR)) != NULL)
8949 	*p = '/';
8950     return scriptname;
8951 }
8952 
8953 /*
8954  * If "name" has a package name try autoloading the script for it.
8955  * Return TRUE if a package was loaded.
8956  */
8957     int
8958 script_autoload(
8959     char_u	*name,
8960     int		reload)	    /* load script again when already loaded */
8961 {
8962     char_u	*p;
8963     char_u	*scriptname, *tofree;
8964     int		ret = FALSE;
8965     int		i;
8966 
8967     /* If there is no '#' after name[0] there is no package name. */
8968     p = vim_strchr(name, AUTOLOAD_CHAR);
8969     if (p == NULL || p == name)
8970 	return FALSE;
8971 
8972     tofree = scriptname = autoload_name(name);
8973 
8974     /* Find the name in the list of previously loaded package names.  Skip
8975      * "autoload/", it's always the same. */
8976     for (i = 0; i < ga_loaded.ga_len; ++i)
8977 	if (STRCMP(((char_u **)ga_loaded.ga_data)[i] + 9, scriptname + 9) == 0)
8978 	    break;
8979     if (!reload && i < ga_loaded.ga_len)
8980 	ret = FALSE;	    /* was loaded already */
8981     else
8982     {
8983 	/* Remember the name if it wasn't loaded already. */
8984 	if (i == ga_loaded.ga_len && ga_grow(&ga_loaded, 1) == OK)
8985 	{
8986 	    ((char_u **)ga_loaded.ga_data)[ga_loaded.ga_len++] = scriptname;
8987 	    tofree = NULL;
8988 	}
8989 
8990 	/* Try loading the package from $VIMRUNTIME/autoload/<name>.vim */
8991 	if (source_runtime(scriptname, 0) == OK)
8992 	    ret = TRUE;
8993     }
8994 
8995     vim_free(tofree);
8996     return ret;
8997 }
8998 
8999 #if defined(FEAT_VIMINFO) || defined(FEAT_SESSION)
9000 typedef enum
9001 {
9002     VAR_FLAVOUR_DEFAULT,	/* doesn't start with uppercase */
9003     VAR_FLAVOUR_SESSION,	/* starts with uppercase, some lower */
9004     VAR_FLAVOUR_VIMINFO		/* all uppercase */
9005 } var_flavour_T;
9006 
9007     static var_flavour_T
9008 var_flavour(char_u *varname)
9009 {
9010     char_u *p = varname;
9011 
9012     if (ASCII_ISUPPER(*p))
9013     {
9014 	while (*(++p))
9015 	    if (ASCII_ISLOWER(*p))
9016 		return VAR_FLAVOUR_SESSION;
9017 	return VAR_FLAVOUR_VIMINFO;
9018     }
9019     else
9020 	return VAR_FLAVOUR_DEFAULT;
9021 }
9022 #endif
9023 
9024 #if defined(FEAT_VIMINFO) || defined(PROTO)
9025 /*
9026  * Restore global vars that start with a capital from the viminfo file
9027  */
9028     int
9029 read_viminfo_varlist(vir_T *virp, int writing)
9030 {
9031     char_u	*tab;
9032     int		type = VAR_NUMBER;
9033     typval_T	tv;
9034     funccal_entry_T funccal_entry;
9035 
9036     if (!writing && (find_viminfo_parameter('!') != NULL))
9037     {
9038 	tab = vim_strchr(virp->vir_line + 1, '\t');
9039 	if (tab != NULL)
9040 	{
9041 	    *tab++ = '\0';	/* isolate the variable name */
9042 	    switch (*tab)
9043 	    {
9044 		case 'S': type = VAR_STRING; break;
9045 #ifdef FEAT_FLOAT
9046 		case 'F': type = VAR_FLOAT; break;
9047 #endif
9048 		case 'D': type = VAR_DICT; break;
9049 		case 'L': type = VAR_LIST; break;
9050 		case 'B': type = VAR_BLOB; break;
9051 		case 'X': type = VAR_SPECIAL; break;
9052 	    }
9053 
9054 	    tab = vim_strchr(tab, '\t');
9055 	    if (tab != NULL)
9056 	    {
9057 		tv.v_type = type;
9058 		if (type == VAR_STRING || type == VAR_DICT
9059 			|| type == VAR_LIST || type == VAR_BLOB)
9060 		    tv.vval.v_string = viminfo_readstring(virp,
9061 				       (int)(tab - virp->vir_line + 1), TRUE);
9062 #ifdef FEAT_FLOAT
9063 		else if (type == VAR_FLOAT)
9064 		    (void)string2float(tab + 1, &tv.vval.v_float);
9065 #endif
9066 		else
9067 		    tv.vval.v_number = atol((char *)tab + 1);
9068 		if (type == VAR_DICT || type == VAR_LIST)
9069 		{
9070 		    typval_T *etv = eval_expr(tv.vval.v_string, NULL);
9071 
9072 		    if (etv == NULL)
9073 			/* Failed to parse back the dict or list, use it as a
9074 			 * string. */
9075 			tv.v_type = VAR_STRING;
9076 		    else
9077 		    {
9078 			vim_free(tv.vval.v_string);
9079 			tv = *etv;
9080 			vim_free(etv);
9081 		    }
9082 		}
9083 		else if (type == VAR_BLOB)
9084 		{
9085 		    blob_T *blob = string2blob(tv.vval.v_string);
9086 
9087 		    if (blob == NULL)
9088 			// Failed to parse back the blob, use it as a string.
9089 			tv.v_type = VAR_STRING;
9090 		    else
9091 		    {
9092 			vim_free(tv.vval.v_string);
9093 			tv.v_type = VAR_BLOB;
9094 			tv.vval.v_blob = blob;
9095 		    }
9096 		}
9097 
9098 		/* when in a function use global variables */
9099 		save_funccal(&funccal_entry);
9100 		set_var(virp->vir_line + 1, &tv, FALSE);
9101 		restore_funccal();
9102 
9103 		if (tv.v_type == VAR_STRING)
9104 		    vim_free(tv.vval.v_string);
9105 		else if (tv.v_type == VAR_DICT || tv.v_type == VAR_LIST ||
9106 			tv.v_type == VAR_BLOB)
9107 		    clear_tv(&tv);
9108 	    }
9109 	}
9110     }
9111 
9112     return viminfo_readline(virp);
9113 }
9114 
9115 /*
9116  * Write global vars that start with a capital to the viminfo file
9117  */
9118     void
9119 write_viminfo_varlist(FILE *fp)
9120 {
9121     hashitem_T	*hi;
9122     dictitem_T	*this_var;
9123     int		todo;
9124     char	*s = "";
9125     char_u	*p;
9126     char_u	*tofree;
9127     char_u	numbuf[NUMBUFLEN];
9128 
9129     if (find_viminfo_parameter('!') == NULL)
9130 	return;
9131 
9132     fputs(_("\n# global variables:\n"), fp);
9133 
9134     todo = (int)globvarht.ht_used;
9135     for (hi = globvarht.ht_array; todo > 0; ++hi)
9136     {
9137 	if (!HASHITEM_EMPTY(hi))
9138 	{
9139 	    --todo;
9140 	    this_var = HI2DI(hi);
9141 	    if (var_flavour(this_var->di_key) == VAR_FLAVOUR_VIMINFO)
9142 	    {
9143 		switch (this_var->di_tv.v_type)
9144 		{
9145 		    case VAR_STRING: s = "STR"; break;
9146 		    case VAR_NUMBER: s = "NUM"; break;
9147 		    case VAR_FLOAT:  s = "FLO"; break;
9148 		    case VAR_DICT:   s = "DIC"; break;
9149 		    case VAR_LIST:   s = "LIS"; break;
9150 		    case VAR_BLOB:   s = "BLO"; break;
9151 		    case VAR_SPECIAL: s = "XPL"; break;
9152 
9153 		    case VAR_UNKNOWN:
9154 		    case VAR_FUNC:
9155 		    case VAR_PARTIAL:
9156 		    case VAR_JOB:
9157 		    case VAR_CHANNEL:
9158 				     continue;
9159 		}
9160 		fprintf(fp, "!%s\t%s\t", this_var->di_key, s);
9161 		if (this_var->di_tv.v_type == VAR_SPECIAL)
9162 		{
9163 		    sprintf((char *)numbuf, "%ld",
9164 					  (long)this_var->di_tv.vval.v_number);
9165 		    p = numbuf;
9166 		    tofree = NULL;
9167 		}
9168 		else
9169 		    p = echo_string(&this_var->di_tv, &tofree, numbuf, 0);
9170 		if (p != NULL)
9171 		    viminfo_writestring(fp, p);
9172 		vim_free(tofree);
9173 	    }
9174 	}
9175     }
9176 }
9177 #endif
9178 
9179 #if defined(FEAT_SESSION) || defined(PROTO)
9180     int
9181 store_session_globals(FILE *fd)
9182 {
9183     hashitem_T	*hi;
9184     dictitem_T	*this_var;
9185     int		todo;
9186     char_u	*p, *t;
9187 
9188     todo = (int)globvarht.ht_used;
9189     for (hi = globvarht.ht_array; todo > 0; ++hi)
9190     {
9191 	if (!HASHITEM_EMPTY(hi))
9192 	{
9193 	    --todo;
9194 	    this_var = HI2DI(hi);
9195 	    if ((this_var->di_tv.v_type == VAR_NUMBER
9196 			|| this_var->di_tv.v_type == VAR_STRING)
9197 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
9198 	    {
9199 		/* Escape special characters with a backslash.  Turn a LF and
9200 		 * CR into \n and \r. */
9201 		p = vim_strsave_escaped(tv_get_string(&this_var->di_tv),
9202 							(char_u *)"\\\"\n\r");
9203 		if (p == NULL)	    /* out of memory */
9204 		    break;
9205 		for (t = p; *t != NUL; ++t)
9206 		    if (*t == '\n')
9207 			*t = 'n';
9208 		    else if (*t == '\r')
9209 			*t = 'r';
9210 		if ((fprintf(fd, "let %s = %c%s%c",
9211 				this_var->di_key,
9212 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
9213 									: ' ',
9214 				p,
9215 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
9216 								   : ' ') < 0)
9217 			|| put_eol(fd) == FAIL)
9218 		{
9219 		    vim_free(p);
9220 		    return FAIL;
9221 		}
9222 		vim_free(p);
9223 	    }
9224 #ifdef FEAT_FLOAT
9225 	    else if (this_var->di_tv.v_type == VAR_FLOAT
9226 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
9227 	    {
9228 		float_T f = this_var->di_tv.vval.v_float;
9229 		int sign = ' ';
9230 
9231 		if (f < 0)
9232 		{
9233 		    f = -f;
9234 		    sign = '-';
9235 		}
9236 		if ((fprintf(fd, "let %s = %c%f",
9237 					       this_var->di_key, sign, f) < 0)
9238 			|| put_eol(fd) == FAIL)
9239 		    return FAIL;
9240 	    }
9241 #endif
9242 	}
9243     }
9244     return OK;
9245 }
9246 #endif
9247 
9248 /*
9249  * Display script name where an item was last set.
9250  * Should only be invoked when 'verbose' is non-zero.
9251  */
9252     void
9253 last_set_msg(sctx_T script_ctx)
9254 {
9255     char_u *p;
9256 
9257     if (script_ctx.sc_sid != 0)
9258     {
9259 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
9260 	if (p != NULL)
9261 	{
9262 	    verbose_enter();
9263 	    msg_puts(_("\n\tLast set from "));
9264 	    msg_puts((char *)p);
9265 	    if (script_ctx.sc_lnum > 0)
9266 	    {
9267 		msg_puts(_(" line "));
9268 		msg_outnum((long)script_ctx.sc_lnum);
9269 	    }
9270 	    verbose_leave();
9271 	    vim_free(p);
9272 	}
9273     }
9274 }
9275 
9276 /*
9277  * Reset v:option_new, v:option_old and v:option_type.
9278  */
9279     void
9280 reset_v_option_vars(void)
9281 {
9282     set_vim_var_string(VV_OPTION_NEW,  NULL, -1);
9283     set_vim_var_string(VV_OPTION_OLD,  NULL, -1);
9284     set_vim_var_string(VV_OPTION_TYPE, NULL, -1);
9285 }
9286 
9287 /*
9288  * Prepare "gap" for an assert error and add the sourcing position.
9289  */
9290     void
9291 prepare_assert_error(garray_T *gap)
9292 {
9293     char buf[NUMBUFLEN];
9294 
9295     ga_init2(gap, 1, 100);
9296     if (sourcing_name != NULL)
9297     {
9298 	ga_concat(gap, sourcing_name);
9299 	if (sourcing_lnum > 0)
9300 	    ga_concat(gap, (char_u *)" ");
9301     }
9302     if (sourcing_lnum > 0)
9303     {
9304 	sprintf(buf, "line %ld", (long)sourcing_lnum);
9305 	ga_concat(gap, (char_u *)buf);
9306     }
9307     if (sourcing_name != NULL || sourcing_lnum > 0)
9308 	ga_concat(gap, (char_u *)": ");
9309 }
9310 
9311 /*
9312  * Add an assert error to v:errors.
9313  */
9314     void
9315 assert_error(garray_T *gap)
9316 {
9317     struct vimvar   *vp = &vimvars[VV_ERRORS];
9318 
9319     if (vp->vv_type != VAR_LIST || vimvars[VV_ERRORS].vv_list == NULL)
9320 	/* Make sure v:errors is a list. */
9321 	set_vim_var_list(VV_ERRORS, list_alloc());
9322     list_append_string(vimvars[VV_ERRORS].vv_list, gap->ga_data, gap->ga_len);
9323 }
9324 
9325     int
9326 assert_equal_common(typval_T *argvars, assert_type_T atype)
9327 {
9328     garray_T	ga;
9329 
9330     if (tv_equal(&argvars[0], &argvars[1], FALSE, FALSE)
9331 						   != (atype == ASSERT_EQUAL))
9332     {
9333 	prepare_assert_error(&ga);
9334 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
9335 								       atype);
9336 	assert_error(&ga);
9337 	ga_clear(&ga);
9338 	return 1;
9339     }
9340     return 0;
9341 }
9342 
9343     int
9344 assert_equalfile(typval_T *argvars)
9345 {
9346     char_u	buf1[NUMBUFLEN];
9347     char_u	buf2[NUMBUFLEN];
9348     char_u	*fname1 = tv_get_string_buf_chk(&argvars[0], buf1);
9349     char_u	*fname2 = tv_get_string_buf_chk(&argvars[1], buf2);
9350     garray_T	ga;
9351     FILE	*fd1;
9352     FILE	*fd2;
9353 
9354     if (fname1 == NULL || fname2 == NULL)
9355 	return 0;
9356 
9357     IObuff[0] = NUL;
9358     fd1 = mch_fopen((char *)fname1, READBIN);
9359     if (fd1 == NULL)
9360     {
9361 	vim_snprintf((char *)IObuff, IOSIZE, (char *)e_notread, fname1);
9362     }
9363     else
9364     {
9365 	fd2 = mch_fopen((char *)fname2, READBIN);
9366 	if (fd2 == NULL)
9367 	{
9368 	    fclose(fd1);
9369 	    vim_snprintf((char *)IObuff, IOSIZE, (char *)e_notread, fname2);
9370 	}
9371 	else
9372 	{
9373 	    int c1, c2;
9374 	    long count = 0;
9375 
9376 	    for (;;)
9377 	    {
9378 		c1 = fgetc(fd1);
9379 		c2 = fgetc(fd2);
9380 		if (c1 == EOF)
9381 		{
9382 		    if (c2 != EOF)
9383 			STRCPY(IObuff, "first file is shorter");
9384 		    break;
9385 		}
9386 		else if (c2 == EOF)
9387 		{
9388 		    STRCPY(IObuff, "second file is shorter");
9389 		    break;
9390 		}
9391 		else if (c1 != c2)
9392 		{
9393 		    vim_snprintf((char *)IObuff, IOSIZE,
9394 					      "difference at byte %ld", count);
9395 		    break;
9396 		}
9397 		++count;
9398 	    }
9399 	    fclose(fd1);
9400 	    fclose(fd2);
9401 	}
9402     }
9403     if (IObuff[0] != NUL)
9404     {
9405 	prepare_assert_error(&ga);
9406 	ga_concat(&ga, IObuff);
9407 	assert_error(&ga);
9408 	ga_clear(&ga);
9409 	return 1;
9410     }
9411     return 0;
9412 }
9413 
9414     int
9415 assert_match_common(typval_T *argvars, assert_type_T atype)
9416 {
9417     garray_T	ga;
9418     char_u	buf1[NUMBUFLEN];
9419     char_u	buf2[NUMBUFLEN];
9420     char_u	*pat = tv_get_string_buf_chk(&argvars[0], buf1);
9421     char_u	*text = tv_get_string_buf_chk(&argvars[1], buf2);
9422 
9423     if (pat == NULL || text == NULL)
9424 	emsg(_(e_invarg));
9425     else if (pattern_match(pat, text, FALSE) != (atype == ASSERT_MATCH))
9426     {
9427 	prepare_assert_error(&ga);
9428 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
9429 									atype);
9430 	assert_error(&ga);
9431 	ga_clear(&ga);
9432 	return 1;
9433     }
9434     return 0;
9435 }
9436 
9437     int
9438 assert_inrange(typval_T *argvars)
9439 {
9440     garray_T	ga;
9441     int		error = FALSE;
9442     char_u	*tofree;
9443     char	msg[200];
9444     char_u	numbuf[NUMBUFLEN];
9445 
9446 #ifdef FEAT_FLOAT
9447     if (argvars[0].v_type == VAR_FLOAT
9448 	    || argvars[1].v_type == VAR_FLOAT
9449 	    || argvars[2].v_type == VAR_FLOAT)
9450     {
9451 	float_T flower = tv_get_float(&argvars[0]);
9452 	float_T fupper = tv_get_float(&argvars[1]);
9453 	float_T factual = tv_get_float(&argvars[2]);
9454 
9455 	if (factual < flower || factual > fupper)
9456 	{
9457 	    prepare_assert_error(&ga);
9458 	    if (argvars[3].v_type != VAR_UNKNOWN)
9459 	    {
9460 		ga_concat(&ga, tv2string(&argvars[3], &tofree, numbuf, 0));
9461 		vim_free(tofree);
9462 	    }
9463 	    else
9464 	    {
9465 		vim_snprintf(msg, 200, "Expected range %g - %g, but got %g",
9466 						      flower, fupper, factual);
9467 		ga_concat(&ga, (char_u *)msg);
9468 	    }
9469 	    assert_error(&ga);
9470 	    ga_clear(&ga);
9471 	    return 1;
9472 	}
9473     }
9474     else
9475 #endif
9476     {
9477 	varnumber_T	lower = tv_get_number_chk(&argvars[0], &error);
9478 	varnumber_T	upper = tv_get_number_chk(&argvars[1], &error);
9479 	varnumber_T	actual = tv_get_number_chk(&argvars[2], &error);
9480 
9481 	if (error)
9482 	    return 0;
9483 	if (actual < lower || actual > upper)
9484 	{
9485 	    prepare_assert_error(&ga);
9486 	    if (argvars[3].v_type != VAR_UNKNOWN)
9487 	    {
9488 		ga_concat(&ga, tv2string(&argvars[3], &tofree, numbuf, 0));
9489 		vim_free(tofree);
9490 	    }
9491 	    else
9492 	    {
9493 		vim_snprintf(msg, 200, "Expected range %ld - %ld, but got %ld",
9494 				       (long)lower, (long)upper, (long)actual);
9495 		ga_concat(&ga, (char_u *)msg);
9496 	    }
9497 	    assert_error(&ga);
9498 	    ga_clear(&ga);
9499 	    return 1;
9500 	}
9501     }
9502     return 0;
9503 }
9504 
9505 /*
9506  * Common for assert_true() and assert_false().
9507  * Return non-zero for failure.
9508  */
9509     int
9510 assert_bool(typval_T *argvars, int isTrue)
9511 {
9512     int		error = FALSE;
9513     garray_T	ga;
9514 
9515     if (argvars[0].v_type == VAR_SPECIAL
9516 	    && argvars[0].vval.v_number == (isTrue ? VVAL_TRUE : VVAL_FALSE))
9517 	return 0;
9518     if (argvars[0].v_type != VAR_NUMBER
9519 	    || (tv_get_number_chk(&argvars[0], &error) == 0) == isTrue
9520 	    || error)
9521     {
9522 	prepare_assert_error(&ga);
9523 	fill_assert_error(&ga, &argvars[1],
9524 		(char_u *)(isTrue ? "True" : "False"),
9525 		NULL, &argvars[0], ASSERT_OTHER);
9526 	assert_error(&ga);
9527 	ga_clear(&ga);
9528 	return 1;
9529     }
9530     return 0;
9531 }
9532 
9533     int
9534 assert_report(typval_T *argvars)
9535 {
9536     garray_T	ga;
9537 
9538     prepare_assert_error(&ga);
9539     ga_concat(&ga, tv_get_string(&argvars[0]));
9540     assert_error(&ga);
9541     ga_clear(&ga);
9542     return 1;
9543 }
9544 
9545     int
9546 assert_exception(typval_T *argvars)
9547 {
9548     garray_T	ga;
9549     char_u	*error = tv_get_string_chk(&argvars[0]);
9550 
9551     if (vimvars[VV_EXCEPTION].vv_str == NULL)
9552     {
9553 	prepare_assert_error(&ga);
9554 	ga_concat(&ga, (char_u *)"v:exception is not set");
9555 	assert_error(&ga);
9556 	ga_clear(&ga);
9557 	return 1;
9558     }
9559     else if (error != NULL
9560 	&& strstr((char *)vimvars[VV_EXCEPTION].vv_str, (char *)error) == NULL)
9561     {
9562 	prepare_assert_error(&ga);
9563 	fill_assert_error(&ga, &argvars[1], NULL, &argvars[0],
9564 				  &vimvars[VV_EXCEPTION].vv_tv, ASSERT_OTHER);
9565 	assert_error(&ga);
9566 	ga_clear(&ga);
9567 	return 1;
9568     }
9569     return 0;
9570 }
9571 
9572     int
9573 assert_beeps(typval_T *argvars)
9574 {
9575     char_u	*cmd = tv_get_string_chk(&argvars[0]);
9576     garray_T	ga;
9577     int		ret = 0;
9578 
9579     called_vim_beep = FALSE;
9580     suppress_errthrow = TRUE;
9581     emsg_silent = FALSE;
9582     do_cmdline_cmd(cmd);
9583     if (!called_vim_beep)
9584     {
9585 	prepare_assert_error(&ga);
9586 	ga_concat(&ga, (char_u *)"command did not beep: ");
9587 	ga_concat(&ga, cmd);
9588 	assert_error(&ga);
9589 	ga_clear(&ga);
9590 	ret = 1;
9591     }
9592 
9593     suppress_errthrow = FALSE;
9594     emsg_on_display = FALSE;
9595     return ret;
9596 }
9597 
9598     static void
9599 assert_append_cmd_or_arg(garray_T *gap, typval_T *argvars, char_u *cmd)
9600 {
9601     char_u	*tofree;
9602     char_u	numbuf[NUMBUFLEN];
9603 
9604     if (argvars[1].v_type != VAR_UNKNOWN && argvars[2].v_type != VAR_UNKNOWN)
9605     {
9606 	ga_concat(gap, echo_string(&argvars[2], &tofree, numbuf, 0));
9607 	vim_free(tofree);
9608     }
9609     else
9610 	ga_concat(gap, cmd);
9611 }
9612 
9613     int
9614 assert_fails(typval_T *argvars)
9615 {
9616     char_u	*cmd = tv_get_string_chk(&argvars[0]);
9617     garray_T	ga;
9618     int		ret = 0;
9619 
9620     called_emsg = FALSE;
9621     suppress_errthrow = TRUE;
9622     emsg_silent = TRUE;
9623     do_cmdline_cmd(cmd);
9624     if (!called_emsg)
9625     {
9626 	prepare_assert_error(&ga);
9627 	ga_concat(&ga, (char_u *)"command did not fail: ");
9628 	assert_append_cmd_or_arg(&ga, argvars, cmd);
9629 	assert_error(&ga);
9630 	ga_clear(&ga);
9631 	ret = 1;
9632     }
9633     else if (argvars[1].v_type != VAR_UNKNOWN)
9634     {
9635 	char_u	buf[NUMBUFLEN];
9636 	char	*error = (char *)tv_get_string_buf_chk(&argvars[1], buf);
9637 
9638 	if (error == NULL
9639 		  || strstr((char *)vimvars[VV_ERRMSG].vv_str, error) == NULL)
9640 	{
9641 	    prepare_assert_error(&ga);
9642 	    fill_assert_error(&ga, &argvars[2], NULL, &argvars[1],
9643 				     &vimvars[VV_ERRMSG].vv_tv, ASSERT_OTHER);
9644 	    ga_concat(&ga, (char_u *)": ");
9645 	    assert_append_cmd_or_arg(&ga, argvars, cmd);
9646 	    assert_error(&ga);
9647 	    ga_clear(&ga);
9648 	ret = 1;
9649 	}
9650     }
9651 
9652     called_emsg = FALSE;
9653     suppress_errthrow = FALSE;
9654     emsg_silent = FALSE;
9655     emsg_on_display = FALSE;
9656     set_vim_var_string(VV_ERRMSG, NULL, 0);
9657     return ret;
9658 }
9659 
9660 /*
9661  * Append "p[clen]" to "gap", escaping unprintable characters.
9662  * Changes NL to \n, CR to \r, etc.
9663  */
9664     static void
9665 ga_concat_esc(garray_T *gap, char_u *p, int clen)
9666 {
9667     char_u  buf[NUMBUFLEN];
9668 
9669     if (clen > 1)
9670     {
9671 	mch_memmove(buf, p, clen);
9672 	buf[clen] = NUL;
9673 	ga_concat(gap, buf);
9674     }
9675     else switch (*p)
9676     {
9677 	case BS: ga_concat(gap, (char_u *)"\\b"); break;
9678 	case ESC: ga_concat(gap, (char_u *)"\\e"); break;
9679 	case FF: ga_concat(gap, (char_u *)"\\f"); break;
9680 	case NL: ga_concat(gap, (char_u *)"\\n"); break;
9681 	case TAB: ga_concat(gap, (char_u *)"\\t"); break;
9682 	case CAR: ga_concat(gap, (char_u *)"\\r"); break;
9683 	case '\\': ga_concat(gap, (char_u *)"\\\\"); break;
9684 	default:
9685 		   if (*p < ' ')
9686 		   {
9687 		       vim_snprintf((char *)buf, NUMBUFLEN, "\\x%02x", *p);
9688 		       ga_concat(gap, buf);
9689 		   }
9690 		   else
9691 		       ga_append(gap, *p);
9692 		   break;
9693     }
9694 }
9695 
9696 /*
9697  * Append "str" to "gap", escaping unprintable characters.
9698  * Changes NL to \n, CR to \r, etc.
9699  */
9700     static void
9701 ga_concat_shorten_esc(garray_T *gap, char_u *str)
9702 {
9703     char_u  *p;
9704     char_u  *s;
9705     int	    c;
9706     int	    clen;
9707     char_u  buf[NUMBUFLEN];
9708     int	    same_len;
9709 
9710     if (str == NULL)
9711     {
9712 	ga_concat(gap, (char_u *)"NULL");
9713 	return;
9714     }
9715 
9716     for (p = str; *p != NUL; ++p)
9717     {
9718 	same_len = 1;
9719 	s = p;
9720 	c = mb_ptr2char_adv(&s);
9721 	clen = s - p;
9722 	while (*s != NUL && c == mb_ptr2char(s))
9723 	{
9724 	    ++same_len;
9725 	    s += clen;
9726 	}
9727 	if (same_len > 20)
9728 	{
9729 	    ga_concat(gap, (char_u *)"\\[");
9730 	    ga_concat_esc(gap, p, clen);
9731 	    ga_concat(gap, (char_u *)" occurs ");
9732 	    vim_snprintf((char *)buf, NUMBUFLEN, "%d", same_len);
9733 	    ga_concat(gap, buf);
9734 	    ga_concat(gap, (char_u *)" times]");
9735 	    p = s - 1;
9736 	}
9737 	else
9738 	    ga_concat_esc(gap, p, clen);
9739     }
9740 }
9741 
9742 /*
9743  * Fill "gap" with information about an assert error.
9744  */
9745     void
9746 fill_assert_error(
9747     garray_T	*gap,
9748     typval_T	*opt_msg_tv,
9749     char_u      *exp_str,
9750     typval_T	*exp_tv,
9751     typval_T	*got_tv,
9752     assert_type_T atype)
9753 {
9754     char_u	numbuf[NUMBUFLEN];
9755     char_u	*tofree;
9756 
9757     if (opt_msg_tv->v_type != VAR_UNKNOWN)
9758     {
9759 	ga_concat(gap, echo_string(opt_msg_tv, &tofree, numbuf, 0));
9760 	vim_free(tofree);
9761 	ga_concat(gap, (char_u *)": ");
9762     }
9763 
9764     if (atype == ASSERT_MATCH || atype == ASSERT_NOTMATCH)
9765 	ga_concat(gap, (char_u *)"Pattern ");
9766     else if (atype == ASSERT_NOTEQUAL)
9767 	ga_concat(gap, (char_u *)"Expected not equal to ");
9768     else
9769 	ga_concat(gap, (char_u *)"Expected ");
9770     if (exp_str == NULL)
9771     {
9772 	ga_concat_shorten_esc(gap, tv2string(exp_tv, &tofree, numbuf, 0));
9773 	vim_free(tofree);
9774     }
9775     else
9776 	ga_concat_shorten_esc(gap, exp_str);
9777     if (atype != ASSERT_NOTEQUAL)
9778     {
9779 	if (atype == ASSERT_MATCH)
9780 	    ga_concat(gap, (char_u *)" does not match ");
9781 	else if (atype == ASSERT_NOTMATCH)
9782 	    ga_concat(gap, (char_u *)" does match ");
9783 	else
9784 	    ga_concat(gap, (char_u *)" but got ");
9785 	ga_concat_shorten_esc(gap, tv2string(got_tv, &tofree, numbuf, 0));
9786 	vim_free(tofree);
9787     }
9788 }
9789 
9790 /*
9791  * Compare "typ1" and "typ2".  Put the result in "typ1".
9792  */
9793     int
9794 typval_compare(
9795     typval_T	*typ1,   /* first operand */
9796     typval_T	*typ2,   /* second operand */
9797     exptype_T	type,    /* operator */
9798     int		type_is, /* TRUE for "is" and "isnot" */
9799     int		ic)      /* ignore case */
9800 {
9801     int		i;
9802     varnumber_T	n1, n2;
9803     char_u	*s1, *s2;
9804     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
9805 
9806     if (type_is && typ1->v_type != typ2->v_type)
9807     {
9808 	/* For "is" a different type always means FALSE, for "notis"
9809 	    * it means TRUE. */
9810 	n1 = (type == TYPE_NEQUAL);
9811     }
9812     else if (typ1->v_type == VAR_BLOB || typ2->v_type == VAR_BLOB)
9813     {
9814 	if (type_is)
9815 	{
9816 	    n1 = (typ1->v_type == typ2->v_type
9817 			    && typ1->vval.v_blob == typ2->vval.v_blob);
9818 	    if (type == TYPE_NEQUAL)
9819 		n1 = !n1;
9820 	}
9821 	else if (typ1->v_type != typ2->v_type
9822 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
9823 	{
9824 	    if (typ1->v_type != typ2->v_type)
9825 		emsg(_("E977: Can only compare Blob with Blob"));
9826 	    else
9827 		emsg(_(e_invalblob));
9828 	    clear_tv(typ1);
9829 	    return FAIL;
9830 	}
9831 	else
9832 	{
9833 	    // Compare two Blobs for being equal or unequal.
9834 	    n1 = blob_equal(typ1->vval.v_blob, typ2->vval.v_blob);
9835 	    if (type == TYPE_NEQUAL)
9836 		n1 = !n1;
9837 	}
9838     }
9839     else if (typ1->v_type == VAR_LIST || typ2->v_type == VAR_LIST)
9840     {
9841 	if (type_is)
9842 	{
9843 	    n1 = (typ1->v_type == typ2->v_type
9844 			    && typ1->vval.v_list == typ2->vval.v_list);
9845 	    if (type == TYPE_NEQUAL)
9846 		n1 = !n1;
9847 	}
9848 	else if (typ1->v_type != typ2->v_type
9849 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
9850 	{
9851 	    if (typ1->v_type != typ2->v_type)
9852 		emsg(_("E691: Can only compare List with List"));
9853 	    else
9854 		emsg(_("E692: Invalid operation for List"));
9855 	    clear_tv(typ1);
9856 	    return FAIL;
9857 	}
9858 	else
9859 	{
9860 	    /* Compare two Lists for being equal or unequal. */
9861 	    n1 = list_equal(typ1->vval.v_list, typ2->vval.v_list,
9862 							    ic, FALSE);
9863 	    if (type == TYPE_NEQUAL)
9864 		n1 = !n1;
9865 	}
9866     }
9867 
9868     else if (typ1->v_type == VAR_DICT || typ2->v_type == VAR_DICT)
9869     {
9870 	if (type_is)
9871 	{
9872 	    n1 = (typ1->v_type == typ2->v_type
9873 			    && typ1->vval.v_dict == typ2->vval.v_dict);
9874 	    if (type == TYPE_NEQUAL)
9875 		n1 = !n1;
9876 	}
9877 	else if (typ1->v_type != typ2->v_type
9878 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
9879 	{
9880 	    if (typ1->v_type != typ2->v_type)
9881 		emsg(_("E735: Can only compare Dictionary with Dictionary"));
9882 	    else
9883 		emsg(_("E736: Invalid operation for Dictionary"));
9884 	    clear_tv(typ1);
9885 	    return FAIL;
9886 	}
9887 	else
9888 	{
9889 	    /* Compare two Dictionaries for being equal or unequal. */
9890 	    n1 = dict_equal(typ1->vval.v_dict, typ2->vval.v_dict,
9891 							    ic, FALSE);
9892 	    if (type == TYPE_NEQUAL)
9893 		n1 = !n1;
9894 	}
9895     }
9896 
9897     else if (typ1->v_type == VAR_FUNC || typ2->v_type == VAR_FUNC
9898 	|| typ1->v_type == VAR_PARTIAL || typ2->v_type == VAR_PARTIAL)
9899     {
9900 	if (type != TYPE_EQUAL && type != TYPE_NEQUAL)
9901 	{
9902 	    emsg(_("E694: Invalid operation for Funcrefs"));
9903 	    clear_tv(typ1);
9904 	    return FAIL;
9905 	}
9906 	if ((typ1->v_type == VAR_PARTIAL
9907 					&& typ1->vval.v_partial == NULL)
9908 		|| (typ2->v_type == VAR_PARTIAL
9909 					&& typ2->vval.v_partial == NULL))
9910 	    /* when a partial is NULL assume not equal */
9911 	    n1 = FALSE;
9912 	else if (type_is)
9913 	{
9914 	    if (typ1->v_type == VAR_FUNC && typ2->v_type == VAR_FUNC)
9915 		/* strings are considered the same if their value is
9916 		    * the same */
9917 		n1 = tv_equal(typ1, typ2, ic, FALSE);
9918 	    else if (typ1->v_type == VAR_PARTIAL
9919 					&& typ2->v_type == VAR_PARTIAL)
9920 		n1 = (typ1->vval.v_partial == typ2->vval.v_partial);
9921 	    else
9922 		n1 = FALSE;
9923 	}
9924 	else
9925 	    n1 = tv_equal(typ1, typ2, ic, FALSE);
9926 	if (type == TYPE_NEQUAL)
9927 	    n1 = !n1;
9928     }
9929 
9930 #ifdef FEAT_FLOAT
9931     /*
9932 	* If one of the two variables is a float, compare as a float.
9933 	* When using "=~" or "!~", always compare as string.
9934 	*/
9935     else if ((typ1->v_type == VAR_FLOAT || typ2->v_type == VAR_FLOAT)
9936 	    && type != TYPE_MATCH && type != TYPE_NOMATCH)
9937     {
9938 	float_T f1, f2;
9939 
9940 	f1 = tv_get_float(typ1);
9941 	f2 = tv_get_float(typ2);
9942 	n1 = FALSE;
9943 	switch (type)
9944 	{
9945 	    case TYPE_EQUAL:    n1 = (f1 == f2); break;
9946 	    case TYPE_NEQUAL:   n1 = (f1 != f2); break;
9947 	    case TYPE_GREATER:  n1 = (f1 > f2); break;
9948 	    case TYPE_GEQUAL:   n1 = (f1 >= f2); break;
9949 	    case TYPE_SMALLER:  n1 = (f1 < f2); break;
9950 	    case TYPE_SEQUAL:   n1 = (f1 <= f2); break;
9951 	    case TYPE_UNKNOWN:
9952 	    case TYPE_MATCH:
9953 	    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
9954 	}
9955     }
9956 #endif
9957 
9958     /*
9959 	* If one of the two variables is a number, compare as a number.
9960 	* When using "=~" or "!~", always compare as string.
9961 	*/
9962     else if ((typ1->v_type == VAR_NUMBER || typ2->v_type == VAR_NUMBER)
9963 	    && type != TYPE_MATCH && type != TYPE_NOMATCH)
9964     {
9965 	n1 = tv_get_number(typ1);
9966 	n2 = tv_get_number(typ2);
9967 	switch (type)
9968 	{
9969 	    case TYPE_EQUAL:    n1 = (n1 == n2); break;
9970 	    case TYPE_NEQUAL:   n1 = (n1 != n2); break;
9971 	    case TYPE_GREATER:  n1 = (n1 > n2); break;
9972 	    case TYPE_GEQUAL:   n1 = (n1 >= n2); break;
9973 	    case TYPE_SMALLER:  n1 = (n1 < n2); break;
9974 	    case TYPE_SEQUAL:   n1 = (n1 <= n2); break;
9975 	    case TYPE_UNKNOWN:
9976 	    case TYPE_MATCH:
9977 	    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
9978 	}
9979     }
9980     else
9981     {
9982 	s1 = tv_get_string_buf(typ1, buf1);
9983 	s2 = tv_get_string_buf(typ2, buf2);
9984 	if (type != TYPE_MATCH && type != TYPE_NOMATCH)
9985 	    i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
9986 	else
9987 	    i = 0;
9988 	n1 = FALSE;
9989 	switch (type)
9990 	{
9991 	    case TYPE_EQUAL:    n1 = (i == 0); break;
9992 	    case TYPE_NEQUAL:   n1 = (i != 0); break;
9993 	    case TYPE_GREATER:  n1 = (i > 0); break;
9994 	    case TYPE_GEQUAL:   n1 = (i >= 0); break;
9995 	    case TYPE_SMALLER:  n1 = (i < 0); break;
9996 	    case TYPE_SEQUAL:   n1 = (i <= 0); break;
9997 
9998 	    case TYPE_MATCH:
9999 	    case TYPE_NOMATCH:
10000 		    n1 = pattern_match(s2, s1, ic);
10001 		    if (type == TYPE_NOMATCH)
10002 			n1 = !n1;
10003 		    break;
10004 
10005 	    case TYPE_UNKNOWN:  break;  /* avoid gcc warning */
10006 	}
10007     }
10008     clear_tv(typ1);
10009     typ1->v_type = VAR_NUMBER;
10010     typ1->vval.v_number = n1;
10011 
10012     return OK;
10013 }
10014 
10015     char_u *
10016 typval_tostring(typval_T *arg)
10017 {
10018     char_u	*tofree;
10019     char_u	numbuf[NUMBUFLEN];
10020     char_u	*ret = NULL;
10021 
10022     if (arg == NULL)
10023 	return vim_strsave((char_u *)"(does not exist)");
10024     ret = tv2string(arg, &tofree, numbuf, 0);
10025     /* Make a copy if we have a value but it's not in allocated memory. */
10026     if (ret != NULL && tofree == NULL)
10027 	ret = vim_strsave(ret);
10028     return ret;
10029 }
10030 
10031     int
10032 var_exists(char_u *var)
10033 {
10034     char_u	*name;
10035     char_u	*tofree;
10036     typval_T    tv;
10037     int		len = 0;
10038     int		n = FALSE;
10039 
10040     /* get_name_len() takes care of expanding curly braces */
10041     name = var;
10042     len = get_name_len(&var, &tofree, TRUE, FALSE);
10043     if (len > 0)
10044     {
10045 	if (tofree != NULL)
10046 	    name = tofree;
10047 	n = (get_var_tv(name, len, &tv, NULL, FALSE, TRUE) == OK);
10048 	if (n)
10049 	{
10050 	    /* handle d.key, l[idx], f(expr) */
10051 	    n = (handle_subscript(&var, &tv, TRUE, FALSE) == OK);
10052 	    if (n)
10053 		clear_tv(&tv);
10054 	}
10055     }
10056     if (*var != NUL)
10057 	n = FALSE;
10058 
10059     vim_free(tofree);
10060     return n;
10061 }
10062 
10063 #endif /* FEAT_EVAL */
10064 
10065 
10066 #if defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) || defined(PROTO)
10067 
10068 #ifdef MSWIN
10069 /*
10070  * Functions for ":8" filename modifier: get 8.3 version of a filename.
10071  */
10072 
10073 /*
10074  * Get the short path (8.3) for the filename in "fnamep".
10075  * Only works for a valid file name.
10076  * When the path gets longer "fnamep" is changed and the allocated buffer
10077  * is put in "bufp".
10078  * *fnamelen is the length of "fnamep" and set to 0 for a nonexistent path.
10079  * Returns OK on success, FAIL on failure.
10080  */
10081     static int
10082 get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen)
10083 {
10084     int		l, len;
10085     char_u	*newbuf;
10086 
10087     len = *fnamelen;
10088     l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, len);
10089     if (l > len - 1)
10090     {
10091 	/* If that doesn't work (not enough space), then save the string
10092 	 * and try again with a new buffer big enough. */
10093 	newbuf = vim_strnsave(*fnamep, l);
10094 	if (newbuf == NULL)
10095 	    return FAIL;
10096 
10097 	vim_free(*bufp);
10098 	*fnamep = *bufp = newbuf;
10099 
10100 	/* Really should always succeed, as the buffer is big enough. */
10101 	l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, l+1);
10102     }
10103 
10104     *fnamelen = l;
10105     return OK;
10106 }
10107 
10108 /*
10109  * Get the short path (8.3) for the filename in "fname". The converted
10110  * path is returned in "bufp".
10111  *
10112  * Some of the directories specified in "fname" may not exist. This function
10113  * will shorten the existing directories at the beginning of the path and then
10114  * append the remaining non-existing path.
10115  *
10116  * fname - Pointer to the filename to shorten.  On return, contains the
10117  *	   pointer to the shortened pathname
10118  * bufp -  Pointer to an allocated buffer for the filename.
10119  * fnamelen - Length of the filename pointed to by fname
10120  *
10121  * Returns OK on success (or nothing done) and FAIL on failure (out of memory).
10122  */
10123     static int
10124 shortpath_for_invalid_fname(
10125     char_u	**fname,
10126     char_u	**bufp,
10127     int		*fnamelen)
10128 {
10129     char_u	*short_fname, *save_fname, *pbuf_unused;
10130     char_u	*endp, *save_endp;
10131     char_u	ch;
10132     int		old_len, len;
10133     int		new_len, sfx_len;
10134     int		retval = OK;
10135 
10136     /* Make a copy */
10137     old_len = *fnamelen;
10138     save_fname = vim_strnsave(*fname, old_len);
10139     pbuf_unused = NULL;
10140     short_fname = NULL;
10141 
10142     endp = save_fname + old_len - 1; /* Find the end of the copy */
10143     save_endp = endp;
10144 
10145     /*
10146      * Try shortening the supplied path till it succeeds by removing one
10147      * directory at a time from the tail of the path.
10148      */
10149     len = 0;
10150     for (;;)
10151     {
10152 	/* go back one path-separator */
10153 	while (endp > save_fname && !after_pathsep(save_fname, endp + 1))
10154 	    --endp;
10155 	if (endp <= save_fname)
10156 	    break;		/* processed the complete path */
10157 
10158 	/*
10159 	 * Replace the path separator with a NUL and try to shorten the
10160 	 * resulting path.
10161 	 */
10162 	ch = *endp;
10163 	*endp = 0;
10164 	short_fname = save_fname;
10165 	len = (int)STRLEN(short_fname) + 1;
10166 	if (get_short_pathname(&short_fname, &pbuf_unused, &len) == FAIL)
10167 	{
10168 	    retval = FAIL;
10169 	    goto theend;
10170 	}
10171 	*endp = ch;	/* preserve the string */
10172 
10173 	if (len > 0)
10174 	    break;	/* successfully shortened the path */
10175 
10176 	/* failed to shorten the path. Skip the path separator */
10177 	--endp;
10178     }
10179 
10180     if (len > 0)
10181     {
10182 	/*
10183 	 * Succeeded in shortening the path. Now concatenate the shortened
10184 	 * path with the remaining path at the tail.
10185 	 */
10186 
10187 	/* Compute the length of the new path. */
10188 	sfx_len = (int)(save_endp - endp) + 1;
10189 	new_len = len + sfx_len;
10190 
10191 	*fnamelen = new_len;
10192 	vim_free(*bufp);
10193 	if (new_len > old_len)
10194 	{
10195 	    /* There is not enough space in the currently allocated string,
10196 	     * copy it to a buffer big enough. */
10197 	    *fname = *bufp = vim_strnsave(short_fname, new_len);
10198 	    if (*fname == NULL)
10199 	    {
10200 		retval = FAIL;
10201 		goto theend;
10202 	    }
10203 	}
10204 	else
10205 	{
10206 	    /* Transfer short_fname to the main buffer (it's big enough),
10207 	     * unless get_short_pathname() did its work in-place. */
10208 	    *fname = *bufp = save_fname;
10209 	    if (short_fname != save_fname)
10210 		vim_strncpy(save_fname, short_fname, len);
10211 	    save_fname = NULL;
10212 	}
10213 
10214 	/* concat the not-shortened part of the path */
10215 	vim_strncpy(*fname + len, endp, sfx_len);
10216 	(*fname)[new_len] = NUL;
10217     }
10218 
10219 theend:
10220     vim_free(pbuf_unused);
10221     vim_free(save_fname);
10222 
10223     return retval;
10224 }
10225 
10226 /*
10227  * Get a pathname for a partial path.
10228  * Returns OK for success, FAIL for failure.
10229  */
10230     static int
10231 shortpath_for_partial(
10232     char_u	**fnamep,
10233     char_u	**bufp,
10234     int		*fnamelen)
10235 {
10236     int		sepcount, len, tflen;
10237     char_u	*p;
10238     char_u	*pbuf, *tfname;
10239     int		hasTilde;
10240 
10241     /* Count up the path separators from the RHS.. so we know which part
10242      * of the path to return. */
10243     sepcount = 0;
10244     for (p = *fnamep; p < *fnamep + *fnamelen; MB_PTR_ADV(p))
10245 	if (vim_ispathsep(*p))
10246 	    ++sepcount;
10247 
10248     /* Need full path first (use expand_env() to remove a "~/") */
10249     hasTilde = (**fnamep == '~');
10250     if (hasTilde)
10251 	pbuf = tfname = expand_env_save(*fnamep);
10252     else
10253 	pbuf = tfname = FullName_save(*fnamep, FALSE);
10254 
10255     len = tflen = (int)STRLEN(tfname);
10256 
10257     if (get_short_pathname(&tfname, &pbuf, &len) == FAIL)
10258 	return FAIL;
10259 
10260     if (len == 0)
10261     {
10262 	/* Don't have a valid filename, so shorten the rest of the
10263 	 * path if we can. This CAN give us invalid 8.3 filenames, but
10264 	 * there's not a lot of point in guessing what it might be.
10265 	 */
10266 	len = tflen;
10267 	if (shortpath_for_invalid_fname(&tfname, &pbuf, &len) == FAIL)
10268 	    return FAIL;
10269     }
10270 
10271     /* Count the paths backward to find the beginning of the desired string. */
10272     for (p = tfname + len - 1; p >= tfname; --p)
10273     {
10274 	if (has_mbyte)
10275 	    p -= mb_head_off(tfname, p);
10276 	if (vim_ispathsep(*p))
10277 	{
10278 	    if (sepcount == 0 || (hasTilde && sepcount == 1))
10279 		break;
10280 	    else
10281 		sepcount --;
10282 	}
10283     }
10284     if (hasTilde)
10285     {
10286 	--p;
10287 	if (p >= tfname)
10288 	    *p = '~';
10289 	else
10290 	    return FAIL;
10291     }
10292     else
10293 	++p;
10294 
10295     /* Copy in the string - p indexes into tfname - allocated at pbuf */
10296     vim_free(*bufp);
10297     *fnamelen = (int)STRLEN(p);
10298     *bufp = pbuf;
10299     *fnamep = p;
10300 
10301     return OK;
10302 }
10303 #endif // MSWIN
10304 
10305 /*
10306  * Adjust a filename, according to a string of modifiers.
10307  * *fnamep must be NUL terminated when called.  When returning, the length is
10308  * determined by *fnamelen.
10309  * Returns VALID_ flags or -1 for failure.
10310  * When there is an error, *fnamep is set to NULL.
10311  */
10312     int
10313 modify_fname(
10314     char_u	*src,		// string with modifiers
10315     int		tilde_file,	// "~" is a file name, not $HOME
10316     int		*usedlen,	// characters after src that are used
10317     char_u	**fnamep,	// file name so far
10318     char_u	**bufp,		// buffer for allocated file name or NULL
10319     int		*fnamelen)	// length of fnamep
10320 {
10321     int		valid = 0;
10322     char_u	*tail;
10323     char_u	*s, *p, *pbuf;
10324     char_u	dirname[MAXPATHL];
10325     int		c;
10326     int		has_fullname = 0;
10327 #ifdef MSWIN
10328     char_u	*fname_start = *fnamep;
10329     int		has_shortname = 0;
10330 #endif
10331 
10332 repeat:
10333     /* ":p" - full path/file_name */
10334     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'p')
10335     {
10336 	has_fullname = 1;
10337 
10338 	valid |= VALID_PATH;
10339 	*usedlen += 2;
10340 
10341 	/* Expand "~/path" for all systems and "~user/path" for Unix and VMS */
10342 	if ((*fnamep)[0] == '~'
10343 #if !defined(UNIX) && !(defined(VMS) && defined(USER_HOME))
10344 		&& ((*fnamep)[1] == '/'
10345 # ifdef BACKSLASH_IN_FILENAME
10346 		    || (*fnamep)[1] == '\\'
10347 # endif
10348 		    || (*fnamep)[1] == NUL)
10349 #endif
10350 		&& !(tilde_file && (*fnamep)[1] == NUL)
10351 	   )
10352 	{
10353 	    *fnamep = expand_env_save(*fnamep);
10354 	    vim_free(*bufp);	/* free any allocated file name */
10355 	    *bufp = *fnamep;
10356 	    if (*fnamep == NULL)
10357 		return -1;
10358 	}
10359 
10360 	/* When "/." or "/.." is used: force expansion to get rid of it. */
10361 	for (p = *fnamep; *p != NUL; MB_PTR_ADV(p))
10362 	{
10363 	    if (vim_ispathsep(*p)
10364 		    && p[1] == '.'
10365 		    && (p[2] == NUL
10366 			|| vim_ispathsep(p[2])
10367 			|| (p[2] == '.'
10368 			    && (p[3] == NUL || vim_ispathsep(p[3])))))
10369 		break;
10370 	}
10371 
10372 	/* FullName_save() is slow, don't use it when not needed. */
10373 	if (*p != NUL || !vim_isAbsName(*fnamep))
10374 	{
10375 	    *fnamep = FullName_save(*fnamep, *p != NUL);
10376 	    vim_free(*bufp);	/* free any allocated file name */
10377 	    *bufp = *fnamep;
10378 	    if (*fnamep == NULL)
10379 		return -1;
10380 	}
10381 
10382 #ifdef MSWIN
10383 # if _WIN32_WINNT >= 0x0500
10384 	if (vim_strchr(*fnamep, '~') != NULL)
10385 	{
10386 	    // Expand 8.3 filename to full path.  Needed to make sure the same
10387 	    // file does not have two different names.
10388 	    // Note: problem does not occur if _WIN32_WINNT < 0x0500.
10389 	    WCHAR *wfname = enc_to_utf16(*fnamep, NULL);
10390 	    WCHAR buf[_MAX_PATH];
10391 
10392 	    if (wfname != NULL)
10393 	    {
10394 		if (GetLongPathNameW(wfname, buf, _MAX_PATH))
10395 		{
10396 		    char_u *p = utf16_to_enc(buf, NULL);
10397 
10398 		    if (p != NULL)
10399 		    {
10400 			vim_free(*bufp);    // free any allocated file name
10401 			*bufp = *fnamep = p;
10402 		    }
10403 		}
10404 		vim_free(wfname);
10405 	    }
10406 	}
10407 # endif
10408 #endif
10409 	/* Append a path separator to a directory. */
10410 	if (mch_isdir(*fnamep))
10411 	{
10412 	    /* Make room for one or two extra characters. */
10413 	    *fnamep = vim_strnsave(*fnamep, (int)STRLEN(*fnamep) + 2);
10414 	    vim_free(*bufp);	/* free any allocated file name */
10415 	    *bufp = *fnamep;
10416 	    if (*fnamep == NULL)
10417 		return -1;
10418 	    add_pathsep(*fnamep);
10419 	}
10420     }
10421 
10422     /* ":." - path relative to the current directory */
10423     /* ":~" - path relative to the home directory */
10424     /* ":8" - shortname path - postponed till after */
10425     while (src[*usedlen] == ':'
10426 		  && ((c = src[*usedlen + 1]) == '.' || c == '~' || c == '8'))
10427     {
10428 	*usedlen += 2;
10429 	if (c == '8')
10430 	{
10431 #ifdef MSWIN
10432 	    has_shortname = 1; /* Postpone this. */
10433 #endif
10434 	    continue;
10435 	}
10436 	pbuf = NULL;
10437 	/* Need full path first (use expand_env() to remove a "~/") */
10438 	if (!has_fullname)
10439 	{
10440 	    if (c == '.' && **fnamep == '~')
10441 		p = pbuf = expand_env_save(*fnamep);
10442 	    else
10443 		p = pbuf = FullName_save(*fnamep, FALSE);
10444 	}
10445 	else
10446 	    p = *fnamep;
10447 
10448 	has_fullname = 0;
10449 
10450 	if (p != NULL)
10451 	{
10452 	    if (c == '.')
10453 	    {
10454 		mch_dirname(dirname, MAXPATHL);
10455 		s = shorten_fname(p, dirname);
10456 		if (s != NULL)
10457 		{
10458 		    *fnamep = s;
10459 		    if (pbuf != NULL)
10460 		    {
10461 			vim_free(*bufp);   /* free any allocated file name */
10462 			*bufp = pbuf;
10463 			pbuf = NULL;
10464 		    }
10465 		}
10466 	    }
10467 	    else
10468 	    {
10469 		home_replace(NULL, p, dirname, MAXPATHL, TRUE);
10470 		/* Only replace it when it starts with '~' */
10471 		if (*dirname == '~')
10472 		{
10473 		    s = vim_strsave(dirname);
10474 		    if (s != NULL)
10475 		    {
10476 			*fnamep = s;
10477 			vim_free(*bufp);
10478 			*bufp = s;
10479 		    }
10480 		}
10481 	    }
10482 	    vim_free(pbuf);
10483 	}
10484     }
10485 
10486     tail = gettail(*fnamep);
10487     *fnamelen = (int)STRLEN(*fnamep);
10488 
10489     /* ":h" - head, remove "/file_name", can be repeated  */
10490     /* Don't remove the first "/" or "c:\" */
10491     while (src[*usedlen] == ':' && src[*usedlen + 1] == 'h')
10492     {
10493 	valid |= VALID_HEAD;
10494 	*usedlen += 2;
10495 	s = get_past_head(*fnamep);
10496 	while (tail > s && after_pathsep(s, tail))
10497 	    MB_PTR_BACK(*fnamep, tail);
10498 	*fnamelen = (int)(tail - *fnamep);
10499 #ifdef VMS
10500 	if (*fnamelen > 0)
10501 	    *fnamelen += 1; /* the path separator is part of the path */
10502 #endif
10503 	if (*fnamelen == 0)
10504 	{
10505 	    /* Result is empty.  Turn it into "." to make ":cd %:h" work. */
10506 	    p = vim_strsave((char_u *)".");
10507 	    if (p == NULL)
10508 		return -1;
10509 	    vim_free(*bufp);
10510 	    *bufp = *fnamep = tail = p;
10511 	    *fnamelen = 1;
10512 	}
10513 	else
10514 	{
10515 	    while (tail > s && !after_pathsep(s, tail))
10516 		MB_PTR_BACK(*fnamep, tail);
10517 	}
10518     }
10519 
10520     /* ":8" - shortname  */
10521     if (src[*usedlen] == ':' && src[*usedlen + 1] == '8')
10522     {
10523 	*usedlen += 2;
10524 #ifdef MSWIN
10525 	has_shortname = 1;
10526 #endif
10527     }
10528 
10529 #ifdef MSWIN
10530     /*
10531      * Handle ":8" after we have done 'heads' and before we do 'tails'.
10532      */
10533     if (has_shortname)
10534     {
10535 	/* Copy the string if it is shortened by :h and when it wasn't copied
10536 	 * yet, because we are going to change it in place.  Avoids changing
10537 	 * the buffer name for "%:8". */
10538 	if (*fnamelen < (int)STRLEN(*fnamep) || *fnamep == fname_start)
10539 	{
10540 	    p = vim_strnsave(*fnamep, *fnamelen);
10541 	    if (p == NULL)
10542 		return -1;
10543 	    vim_free(*bufp);
10544 	    *bufp = *fnamep = p;
10545 	}
10546 
10547 	/* Split into two implementations - makes it easier.  First is where
10548 	 * there isn't a full name already, second is where there is. */
10549 	if (!has_fullname && !vim_isAbsName(*fnamep))
10550 	{
10551 	    if (shortpath_for_partial(fnamep, bufp, fnamelen) == FAIL)
10552 		return -1;
10553 	}
10554 	else
10555 	{
10556 	    int		l = *fnamelen;
10557 
10558 	    /* Simple case, already have the full-name.
10559 	     * Nearly always shorter, so try first time. */
10560 	    if (get_short_pathname(fnamep, bufp, &l) == FAIL)
10561 		return -1;
10562 
10563 	    if (l == 0)
10564 	    {
10565 		/* Couldn't find the filename, search the paths. */
10566 		l = *fnamelen;
10567 		if (shortpath_for_invalid_fname(fnamep, bufp, &l) == FAIL)
10568 		    return -1;
10569 	    }
10570 	    *fnamelen = l;
10571 	}
10572     }
10573 #endif // MSWIN
10574 
10575     /* ":t" - tail, just the basename */
10576     if (src[*usedlen] == ':' && src[*usedlen + 1] == 't')
10577     {
10578 	*usedlen += 2;
10579 	*fnamelen -= (int)(tail - *fnamep);
10580 	*fnamep = tail;
10581     }
10582 
10583     /* ":e" - extension, can be repeated */
10584     /* ":r" - root, without extension, can be repeated */
10585     while (src[*usedlen] == ':'
10586 	    && (src[*usedlen + 1] == 'e' || src[*usedlen + 1] == 'r'))
10587     {
10588 	/* find a '.' in the tail:
10589 	 * - for second :e: before the current fname
10590 	 * - otherwise: The last '.'
10591 	 */
10592 	if (src[*usedlen + 1] == 'e' && *fnamep > tail)
10593 	    s = *fnamep - 2;
10594 	else
10595 	    s = *fnamep + *fnamelen - 1;
10596 	for ( ; s > tail; --s)
10597 	    if (s[0] == '.')
10598 		break;
10599 	if (src[*usedlen + 1] == 'e')		/* :e */
10600 	{
10601 	    if (s > tail)
10602 	    {
10603 		*fnamelen += (int)(*fnamep - (s + 1));
10604 		*fnamep = s + 1;
10605 #ifdef VMS
10606 		/* cut version from the extension */
10607 		s = *fnamep + *fnamelen - 1;
10608 		for ( ; s > *fnamep; --s)
10609 		    if (s[0] == ';')
10610 			break;
10611 		if (s > *fnamep)
10612 		    *fnamelen = s - *fnamep;
10613 #endif
10614 	    }
10615 	    else if (*fnamep <= tail)
10616 		*fnamelen = 0;
10617 	}
10618 	else				/* :r */
10619 	{
10620 	    if (s > tail)	/* remove one extension */
10621 		*fnamelen = (int)(s - *fnamep);
10622 	}
10623 	*usedlen += 2;
10624     }
10625 
10626     /* ":s?pat?foo?" - substitute */
10627     /* ":gs?pat?foo?" - global substitute */
10628     if (src[*usedlen] == ':'
10629 	    && (src[*usedlen + 1] == 's'
10630 		|| (src[*usedlen + 1] == 'g' && src[*usedlen + 2] == 's')))
10631     {
10632 	char_u	    *str;
10633 	char_u	    *pat;
10634 	char_u	    *sub;
10635 	int	    sep;
10636 	char_u	    *flags;
10637 	int	    didit = FALSE;
10638 
10639 	flags = (char_u *)"";
10640 	s = src + *usedlen + 2;
10641 	if (src[*usedlen + 1] == 'g')
10642 	{
10643 	    flags = (char_u *)"g";
10644 	    ++s;
10645 	}
10646 
10647 	sep = *s++;
10648 	if (sep)
10649 	{
10650 	    /* find end of pattern */
10651 	    p = vim_strchr(s, sep);
10652 	    if (p != NULL)
10653 	    {
10654 		pat = vim_strnsave(s, (int)(p - s));
10655 		if (pat != NULL)
10656 		{
10657 		    s = p + 1;
10658 		    /* find end of substitution */
10659 		    p = vim_strchr(s, sep);
10660 		    if (p != NULL)
10661 		    {
10662 			sub = vim_strnsave(s, (int)(p - s));
10663 			str = vim_strnsave(*fnamep, *fnamelen);
10664 			if (sub != NULL && str != NULL)
10665 			{
10666 			    *usedlen = (int)(p + 1 - src);
10667 			    s = do_string_sub(str, pat, sub, NULL, flags);
10668 			    if (s != NULL)
10669 			    {
10670 				*fnamep = s;
10671 				*fnamelen = (int)STRLEN(s);
10672 				vim_free(*bufp);
10673 				*bufp = s;
10674 				didit = TRUE;
10675 			    }
10676 			}
10677 			vim_free(sub);
10678 			vim_free(str);
10679 		    }
10680 		    vim_free(pat);
10681 		}
10682 	    }
10683 	    /* after using ":s", repeat all the modifiers */
10684 	    if (didit)
10685 		goto repeat;
10686 	}
10687     }
10688 
10689     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'S')
10690     {
10691 	/* vim_strsave_shellescape() needs a NUL terminated string. */
10692 	c = (*fnamep)[*fnamelen];
10693 	if (c != NUL)
10694 	    (*fnamep)[*fnamelen] = NUL;
10695 	p = vim_strsave_shellescape(*fnamep, FALSE, FALSE);
10696 	if (c != NUL)
10697 	    (*fnamep)[*fnamelen] = c;
10698 	if (p == NULL)
10699 	    return -1;
10700 	vim_free(*bufp);
10701 	*bufp = *fnamep = p;
10702 	*fnamelen = (int)STRLEN(p);
10703 	*usedlen += 2;
10704     }
10705 
10706     return valid;
10707 }
10708 
10709 /*
10710  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
10711  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
10712  * "flags" can be "g" to do a global substitute.
10713  * Returns an allocated string, NULL for error.
10714  */
10715     char_u *
10716 do_string_sub(
10717     char_u	*str,
10718     char_u	*pat,
10719     char_u	*sub,
10720     typval_T	*expr,
10721     char_u	*flags)
10722 {
10723     int		sublen;
10724     regmatch_T	regmatch;
10725     int		i;
10726     int		do_all;
10727     char_u	*tail;
10728     char_u	*end;
10729     garray_T	ga;
10730     char_u	*ret;
10731     char_u	*save_cpo;
10732     char_u	*zero_width = NULL;
10733 
10734     /* Make 'cpoptions' empty, so that the 'l' flag doesn't work here */
10735     save_cpo = p_cpo;
10736     p_cpo = empty_option;
10737 
10738     ga_init2(&ga, 1, 200);
10739 
10740     do_all = (flags[0] == 'g');
10741 
10742     regmatch.rm_ic = p_ic;
10743     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
10744     if (regmatch.regprog != NULL)
10745     {
10746 	tail = str;
10747 	end = str + STRLEN(str);
10748 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
10749 	{
10750 	    /* Skip empty match except for first match. */
10751 	    if (regmatch.startp[0] == regmatch.endp[0])
10752 	    {
10753 		if (zero_width == regmatch.startp[0])
10754 		{
10755 		    /* avoid getting stuck on a match with an empty string */
10756 		    i = MB_PTR2LEN(tail);
10757 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
10758 								   (size_t)i);
10759 		    ga.ga_len += i;
10760 		    tail += i;
10761 		    continue;
10762 		}
10763 		zero_width = regmatch.startp[0];
10764 	    }
10765 
10766 	    /*
10767 	     * Get some space for a temporary buffer to do the substitution
10768 	     * into.  It will contain:
10769 	     * - The text up to where the match is.
10770 	     * - The substituted text.
10771 	     * - The text after the match.
10772 	     */
10773 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
10774 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
10775 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
10776 	    {
10777 		ga_clear(&ga);
10778 		break;
10779 	    }
10780 
10781 	    /* copy the text up to where the match is */
10782 	    i = (int)(regmatch.startp[0] - tail);
10783 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
10784 	    /* add the substituted text */
10785 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
10786 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
10787 	    ga.ga_len += i + sublen - 1;
10788 	    tail = regmatch.endp[0];
10789 	    if (*tail == NUL)
10790 		break;
10791 	    if (!do_all)
10792 		break;
10793 	}
10794 
10795 	if (ga.ga_data != NULL)
10796 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
10797 
10798 	vim_regfree(regmatch.regprog);
10799     }
10800 
10801     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
10802     ga_clear(&ga);
10803     if (p_cpo == empty_option)
10804 	p_cpo = save_cpo;
10805     else
10806 	/* Darn, evaluating {sub} expression or {expr} changed the value. */
10807 	free_string_option(save_cpo);
10808 
10809     return ret;
10810 }
10811 
10812     static int
10813 filter_map_one(typval_T *tv, typval_T *expr, int map, int *remp)
10814 {
10815     typval_T	rettv;
10816     typval_T	argv[3];
10817     int		retval = FAIL;
10818 
10819     copy_tv(tv, &vimvars[VV_VAL].vv_tv);
10820     argv[0] = vimvars[VV_KEY].vv_tv;
10821     argv[1] = vimvars[VV_VAL].vv_tv;
10822     if (eval_expr_typval(expr, argv, 2, &rettv) == FAIL)
10823 	goto theend;
10824     if (map)
10825     {
10826 	/* map(): replace the list item value */
10827 	clear_tv(tv);
10828 	rettv.v_lock = 0;
10829 	*tv = rettv;
10830     }
10831     else
10832     {
10833 	int	    error = FALSE;
10834 
10835 	/* filter(): when expr is zero remove the item */
10836 	*remp = (tv_get_number_chk(&rettv, &error) == 0);
10837 	clear_tv(&rettv);
10838 	/* On type error, nothing has been removed; return FAIL to stop the
10839 	 * loop.  The error message was given by tv_get_number_chk(). */
10840 	if (error)
10841 	    goto theend;
10842     }
10843     retval = OK;
10844 theend:
10845     clear_tv(&vimvars[VV_VAL].vv_tv);
10846     return retval;
10847 }
10848 
10849 
10850 /*
10851  * Implementation of map() and filter().
10852  */
10853     void
10854 filter_map(typval_T *argvars, typval_T *rettv, int map)
10855 {
10856     typval_T	*expr;
10857     listitem_T	*li, *nli;
10858     list_T	*l = NULL;
10859     dictitem_T	*di;
10860     hashtab_T	*ht;
10861     hashitem_T	*hi;
10862     dict_T	*d = NULL;
10863     typval_T	save_val;
10864     typval_T	save_key;
10865     blob_T	*b = NULL;
10866     int		rem;
10867     int		todo;
10868     char_u	*ermsg = (char_u *)(map ? "map()" : "filter()");
10869     char_u	*arg_errmsg = (char_u *)(map ? N_("map() argument")
10870 				   : N_("filter() argument"));
10871     int		save_did_emsg;
10872     int		idx = 0;
10873 
10874     if (argvars[0].v_type == VAR_BLOB)
10875     {
10876 	if ((b = argvars[0].vval.v_blob) == NULL)
10877 	    return;
10878     }
10879     else if (argvars[0].v_type == VAR_LIST)
10880     {
10881 	if ((l = argvars[0].vval.v_list) == NULL
10882 	      || (!map && var_check_lock(l->lv_lock, arg_errmsg, TRUE)))
10883 	    return;
10884     }
10885     else if (argvars[0].v_type == VAR_DICT)
10886     {
10887 	if ((d = argvars[0].vval.v_dict) == NULL
10888 	      || (!map && var_check_lock(d->dv_lock, arg_errmsg, TRUE)))
10889 	    return;
10890     }
10891     else
10892     {
10893 	semsg(_(e_listdictarg), ermsg);
10894 	return;
10895     }
10896 
10897     expr = &argvars[1];
10898     /* On type errors, the preceding call has already displayed an error
10899      * message.  Avoid a misleading error message for an empty string that
10900      * was not passed as argument. */
10901     if (expr->v_type != VAR_UNKNOWN)
10902     {
10903 	prepare_vimvar(VV_VAL, &save_val);
10904 
10905 	/* We reset "did_emsg" to be able to detect whether an error
10906 	 * occurred during evaluation of the expression. */
10907 	save_did_emsg = did_emsg;
10908 	did_emsg = FALSE;
10909 
10910 	prepare_vimvar(VV_KEY, &save_key);
10911 	if (argvars[0].v_type == VAR_DICT)
10912 	{
10913 	    vimvars[VV_KEY].vv_type = VAR_STRING;
10914 
10915 	    ht = &d->dv_hashtab;
10916 	    hash_lock(ht);
10917 	    todo = (int)ht->ht_used;
10918 	    for (hi = ht->ht_array; todo > 0; ++hi)
10919 	    {
10920 		if (!HASHITEM_EMPTY(hi))
10921 		{
10922 		    int r;
10923 
10924 		    --todo;
10925 		    di = HI2DI(hi);
10926 		    if (map && (var_check_lock(di->di_tv.v_lock,
10927 							   arg_errmsg, TRUE)
10928 				|| var_check_ro(di->di_flags,
10929 							   arg_errmsg, TRUE)))
10930 			break;
10931 		    vimvars[VV_KEY].vv_str = vim_strsave(di->di_key);
10932 		    r = filter_map_one(&di->di_tv, expr, map, &rem);
10933 		    clear_tv(&vimvars[VV_KEY].vv_tv);
10934 		    if (r == FAIL || did_emsg)
10935 			break;
10936 		    if (!map && rem)
10937 		    {
10938 			if (var_check_fixed(di->di_flags, arg_errmsg, TRUE)
10939 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE))
10940 			    break;
10941 			dictitem_remove(d, di);
10942 		    }
10943 		}
10944 	    }
10945 	    hash_unlock(ht);
10946 	}
10947 	else if (argvars[0].v_type == VAR_BLOB)
10948 	{
10949 	    int		i;
10950 	    typval_T	tv;
10951 
10952 	    vimvars[VV_KEY].vv_type = VAR_NUMBER;
10953 	    for (i = 0; i < b->bv_ga.ga_len; i++)
10954 	    {
10955 		tv.v_type = VAR_NUMBER;
10956 		tv.vval.v_number = blob_get(b, i);
10957 		vimvars[VV_KEY].vv_nr = idx;
10958 		if (filter_map_one(&tv, expr, map, &rem) == FAIL || did_emsg)
10959 		    break;
10960 		if (tv.v_type != VAR_NUMBER)
10961 		{
10962 		    emsg(_(e_invalblob));
10963 		    return;
10964 		}
10965 		tv.v_type = VAR_NUMBER;
10966 		blob_set(b, i, tv.vval.v_number);
10967 		if (!map && rem)
10968 		{
10969 		    char_u *p = (char_u *)argvars[0].vval.v_blob->bv_ga.ga_data;
10970 
10971 		    mch_memmove(p + idx, p + i + 1,
10972 					      (size_t)b->bv_ga.ga_len - i - 1);
10973 		    --b->bv_ga.ga_len;
10974 		    --i;
10975 		}
10976 	    }
10977 	}
10978 	else
10979 	{
10980 	    // argvars[0].v_type == VAR_LIST
10981 	    vimvars[VV_KEY].vv_type = VAR_NUMBER;
10982 
10983 	    for (li = l->lv_first; li != NULL; li = nli)
10984 	    {
10985 		if (map && var_check_lock(li->li_tv.v_lock, arg_errmsg, TRUE))
10986 		    break;
10987 		nli = li->li_next;
10988 		vimvars[VV_KEY].vv_nr = idx;
10989 		if (filter_map_one(&li->li_tv, expr, map, &rem) == FAIL
10990 								  || did_emsg)
10991 		    break;
10992 		if (!map && rem)
10993 		    listitem_remove(l, li);
10994 		++idx;
10995 	    }
10996 	}
10997 
10998 	restore_vimvar(VV_KEY, &save_key);
10999 	restore_vimvar(VV_VAL, &save_val);
11000 
11001 	did_emsg |= save_did_emsg;
11002     }
11003 
11004     copy_tv(&argvars[0], rettv);
11005 }
11006 
11007 #endif /* defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) */
11008