xref: /vim-8.2.3635/src/eval.c (revision fcfe1a9b)
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 static char *e_cannot_mod = N_("E995: Cannot modify existing variable");
32 #ifdef FEAT_FLOAT
33 static char *e_float_as_string = N_("E806: using Float as a String");
34 #endif
35 
36 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
37 
38 static dictitem_T	globvars_var;		/* variable used for g: */
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_oldlocal",	 VAR_STRING), VV_RO},
175     {VV_NAME("option_oldglobal", VAR_STRING), VV_RO},
176     {VV_NAME("option_command",	 VAR_STRING), VV_RO},
177     {VV_NAME("option_type",	 VAR_STRING), VV_RO},
178     {VV_NAME("errors",		 VAR_LIST), 0},
179     {VV_NAME("false",		 VAR_SPECIAL), VV_RO},
180     {VV_NAME("true",		 VAR_SPECIAL), VV_RO},
181     {VV_NAME("null",		 VAR_SPECIAL), VV_RO},
182     {VV_NAME("none",		 VAR_SPECIAL), VV_RO},
183     {VV_NAME("vim_did_enter",	 VAR_NUMBER), VV_RO},
184     {VV_NAME("testing",		 VAR_NUMBER), 0},
185     {VV_NAME("t_number",	 VAR_NUMBER), VV_RO},
186     {VV_NAME("t_string",	 VAR_NUMBER), VV_RO},
187     {VV_NAME("t_func",		 VAR_NUMBER), VV_RO},
188     {VV_NAME("t_list",		 VAR_NUMBER), VV_RO},
189     {VV_NAME("t_dict",		 VAR_NUMBER), VV_RO},
190     {VV_NAME("t_float",		 VAR_NUMBER), VV_RO},
191     {VV_NAME("t_bool",		 VAR_NUMBER), VV_RO},
192     {VV_NAME("t_none",		 VAR_NUMBER), VV_RO},
193     {VV_NAME("t_job",		 VAR_NUMBER), VV_RO},
194     {VV_NAME("t_channel",	 VAR_NUMBER), VV_RO},
195     {VV_NAME("t_blob",		 VAR_NUMBER), VV_RO},
196     {VV_NAME("termrfgresp",	 VAR_STRING), VV_RO},
197     {VV_NAME("termrbgresp",	 VAR_STRING), VV_RO},
198     {VV_NAME("termu7resp",	 VAR_STRING), VV_RO},
199     {VV_NAME("termstyleresp",	 VAR_STRING), VV_RO},
200     {VV_NAME("termblinkresp",	 VAR_STRING), VV_RO},
201     {VV_NAME("event",		 VAR_DICT), VV_RO},
202     {VV_NAME("versionlong",	 VAR_NUMBER), VV_RO},
203 };
204 
205 /* shorthand */
206 #define vv_type		vv_di.di_tv.v_type
207 #define vv_nr		vv_di.di_tv.vval.v_number
208 #define vv_float	vv_di.di_tv.vval.v_float
209 #define vv_str		vv_di.di_tv.vval.v_string
210 #define vv_list		vv_di.di_tv.vval.v_list
211 #define vv_dict		vv_di.di_tv.vval.v_dict
212 #define vv_blob		vv_di.di_tv.vval.v_blob
213 #define vv_tv		vv_di.di_tv
214 
215 static dictitem_T	vimvars_var;		/* variable used for v: */
216 #define vimvarht  vimvardict.dv_hashtab
217 
218 static void ex_let_const(exarg_T *eap, int is_const);
219 static int ex_let_vars(char_u *arg, typval_T *tv, int copy, int semicolon, int var_count, int is_const, char_u *nextchars);
220 static char_u *skip_var_list(char_u *arg, int *var_count, int *semicolon);
221 static char_u *skip_var_one(char_u *arg);
222 static void list_glob_vars(int *first);
223 static void list_buf_vars(int *first);
224 static void list_win_vars(int *first);
225 static void list_tab_vars(int *first);
226 static void list_vim_vars(int *first);
227 static void list_script_vars(int *first);
228 static char_u *list_arg_vars(exarg_T *eap, char_u *arg, int *first);
229 static char_u *ex_let_one(char_u *arg, typval_T *tv, int copy, int is_const, char_u *endchars, char_u *op);
230 static void set_var_lval(lval_T *lp, char_u *endp, typval_T *rettv, int copy, int is_const, char_u *op);
231 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
232 static void ex_unletlock(exarg_T *eap, char_u *argstart, int deep);
233 static int do_unlet_var(lval_T *lp, char_u *name_end, int forceit);
234 static int do_lock_var(lval_T *lp, char_u *name_end, int deep, int lock);
235 static void item_lock(typval_T *tv, int deep, int lock);
236 
237 static int eval2(char_u **arg, typval_T *rettv, int evaluate);
238 static int eval3(char_u **arg, typval_T *rettv, int evaluate);
239 static int eval4(char_u **arg, typval_T *rettv, int evaluate);
240 static int eval5(char_u **arg, typval_T *rettv, int evaluate);
241 static int eval6(char_u **arg, typval_T *rettv, int evaluate, int want_string);
242 static int eval7(char_u **arg, typval_T *rettv, int evaluate, int want_string);
243 
244 static int get_string_tv(char_u **arg, typval_T *rettv, int evaluate);
245 static int get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate);
246 static int free_unref_items(int copyID);
247 static int get_env_tv(char_u **arg, typval_T *rettv, int evaluate);
248 static int get_env_len(char_u **arg);
249 static char_u * make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
250 static void check_vars(char_u *name, int len);
251 static typval_T *alloc_string_tv(char_u *string);
252 static void delete_var(hashtab_T *ht, hashitem_T *hi);
253 static void list_one_var(dictitem_T *v, char *prefix, int *first);
254 static void list_one_var_a(char *prefix, char_u *name, int type, char_u *string, int *first);
255 static void set_var_const(char_u *name, typval_T *tv, int copy, int is_const);
256 static int tv_check_lock(typval_T *tv, char_u *name, int use_gettext);
257 static char_u *find_option_end(char_u **arg, int *opt_flags);
258 
259 /* for VIM_VERSION_ defines */
260 #include "version.h"
261 
262 /*
263  * Return "n1" divided by "n2", taking care of dividing by zero.
264  */
265 	static varnumber_T
266 num_divide(varnumber_T n1, varnumber_T n2)
267 {
268     varnumber_T	result;
269 
270     if (n2 == 0)	// give an error message?
271     {
272 	if (n1 == 0)
273 	    result = VARNUM_MIN; // similar to NaN
274 	else if (n1 < 0)
275 	    result = -VARNUM_MAX;
276 	else
277 	    result = VARNUM_MAX;
278     }
279     else
280 	result = n1 / n2;
281 
282     return result;
283 }
284 
285 /*
286  * Return "n1" modulus "n2", taking care of dividing by zero.
287  */
288 	static varnumber_T
289 num_modulus(varnumber_T n1, varnumber_T n2)
290 {
291     // Give an error when n2 is 0?
292     return (n2 == 0) ? 0 : (n1 % n2);
293 }
294 
295 
296 #if defined(EBCDIC) || defined(PROTO)
297 /*
298  * Compare struct fst by function name.
299  */
300     static int
301 compare_func_name(const void *s1, const void *s2)
302 {
303     struct fst *p1 = (struct fst *)s1;
304     struct fst *p2 = (struct fst *)s2;
305 
306     return STRCMP(p1->f_name, p2->f_name);
307 }
308 
309 /*
310  * Sort the function table by function name.
311  * The sorting of the table above is ASCII dependent.
312  * On machines using EBCDIC we have to sort it.
313  */
314     static void
315 sortFunctions(void)
316 {
317     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
318 
319     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
320 }
321 #endif
322 
323 
324 /*
325  * Initialize the global and v: variables.
326  */
327     void
328 eval_init(void)
329 {
330     int		    i;
331     struct vimvar   *p;
332 
333     init_var_dict(&globvardict, &globvars_var, VAR_DEF_SCOPE);
334     init_var_dict(&vimvardict, &vimvars_var, VAR_SCOPE);
335     vimvardict.dv_lock = VAR_FIXED;
336     hash_init(&compat_hashtab);
337     func_init();
338 
339     for (i = 0; i < VV_LEN; ++i)
340     {
341 	p = &vimvars[i];
342 	if (STRLEN(p->vv_name) > DICTITEM16_KEY_LEN)
343 	{
344 	    iemsg("INTERNAL: name too long, increase size of dictitem16_T");
345 	    getout(1);
346 	}
347 	STRCPY(p->vv_di.di_key, p->vv_name);
348 	if (p->vv_flags & VV_RO)
349 	    p->vv_di.di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
350 	else if (p->vv_flags & VV_RO_SBX)
351 	    p->vv_di.di_flags = DI_FLAGS_RO_SBX | DI_FLAGS_FIX;
352 	else
353 	    p->vv_di.di_flags = DI_FLAGS_FIX;
354 
355 	/* add to v: scope dict, unless the value is not always available */
356 	if (p->vv_type != VAR_UNKNOWN)
357 	    hash_add(&vimvarht, p->vv_di.di_key);
358 	if (p->vv_flags & VV_COMPAT)
359 	    /* add to compat scope dict */
360 	    hash_add(&compat_hashtab, p->vv_di.di_key);
361     }
362     vimvars[VV_VERSION].vv_nr = VIM_VERSION_100;
363     vimvars[VV_VERSIONLONG].vv_nr = VIM_VERSION_100 * 10000 + highest_patch();
364 
365     set_vim_var_nr(VV_SEARCHFORWARD, 1L);
366     set_vim_var_nr(VV_HLSEARCH, 1L);
367     set_vim_var_dict(VV_COMPLETED_ITEM, dict_alloc_lock(VAR_FIXED));
368     set_vim_var_list(VV_ERRORS, list_alloc());
369     set_vim_var_dict(VV_EVENT, dict_alloc_lock(VAR_FIXED));
370 
371     set_vim_var_nr(VV_FALSE, VVAL_FALSE);
372     set_vim_var_nr(VV_TRUE, VVAL_TRUE);
373     set_vim_var_nr(VV_NONE, VVAL_NONE);
374     set_vim_var_nr(VV_NULL, VVAL_NULL);
375 
376     set_vim_var_nr(VV_TYPE_NUMBER,  VAR_TYPE_NUMBER);
377     set_vim_var_nr(VV_TYPE_STRING,  VAR_TYPE_STRING);
378     set_vim_var_nr(VV_TYPE_FUNC,    VAR_TYPE_FUNC);
379     set_vim_var_nr(VV_TYPE_LIST,    VAR_TYPE_LIST);
380     set_vim_var_nr(VV_TYPE_DICT,    VAR_TYPE_DICT);
381     set_vim_var_nr(VV_TYPE_FLOAT,   VAR_TYPE_FLOAT);
382     set_vim_var_nr(VV_TYPE_BOOL,    VAR_TYPE_BOOL);
383     set_vim_var_nr(VV_TYPE_NONE,    VAR_TYPE_NONE);
384     set_vim_var_nr(VV_TYPE_JOB,     VAR_TYPE_JOB);
385     set_vim_var_nr(VV_TYPE_CHANNEL, VAR_TYPE_CHANNEL);
386     set_vim_var_nr(VV_TYPE_BLOB,    VAR_TYPE_BLOB);
387 
388     set_reg_var(0);  /* default for v:register is not 0 but '"' */
389 
390 #ifdef EBCDIC
391     /*
392      * Sort the function table, to enable binary search.
393      */
394     sortFunctions();
395 #endif
396 }
397 
398 #if defined(EXITFREE) || defined(PROTO)
399     void
400 eval_clear(void)
401 {
402     int		    i;
403     struct vimvar   *p;
404 
405     for (i = 0; i < VV_LEN; ++i)
406     {
407 	p = &vimvars[i];
408 	if (p->vv_di.di_tv.v_type == VAR_STRING)
409 	    VIM_CLEAR(p->vv_str);
410 	else if (p->vv_di.di_tv.v_type == VAR_LIST)
411 	{
412 	    list_unref(p->vv_list);
413 	    p->vv_list = NULL;
414 	}
415     }
416     hash_clear(&vimvarht);
417     hash_init(&vimvarht);  /* garbage_collect() will access it */
418     hash_clear(&compat_hashtab);
419 
420     free_scriptnames();
421 # if defined(FEAT_CMDL_COMPL)
422     free_locales();
423 # endif
424 
425     /* global variables */
426     vars_clear(&globvarht);
427 
428     /* autoloaded script names */
429     ga_clear_strings(&ga_loaded);
430 
431     /* Script-local variables. First clear all the variables and in a second
432      * loop free the scriptvar_T, because a variable in one script might hold
433      * a reference to the whole scope of another script. */
434     for (i = 1; i <= ga_scripts.ga_len; ++i)
435 	vars_clear(&SCRIPT_VARS(i));
436     for (i = 1; i <= ga_scripts.ga_len; ++i)
437 	vim_free(SCRIPT_SV(i));
438     ga_clear(&ga_scripts);
439 
440     // unreferenced lists and dicts
441     (void)garbage_collect(FALSE);
442 
443     // functions not garbage collected
444     free_all_functions();
445 }
446 #endif
447 
448 
449 /*
450  * Set an internal variable to a string value. Creates the variable if it does
451  * not already exist.
452  */
453     void
454 set_internal_string_var(char_u *name, char_u *value)
455 {
456     char_u	*val;
457     typval_T	*tvp;
458 
459     val = vim_strsave(value);
460     if (val != NULL)
461     {
462 	tvp = alloc_string_tv(val);
463 	if (tvp != NULL)
464 	{
465 	    set_var(name, tvp, FALSE);
466 	    free_tv(tvp);
467 	}
468     }
469 }
470 
471 static lval_T	*redir_lval = NULL;
472 #define EVALCMD_BUSY (redir_lval == (lval_T *)&redir_lval)
473 static garray_T redir_ga;	/* only valid when redir_lval is not NULL */
474 static char_u	*redir_endp = NULL;
475 static char_u	*redir_varname = NULL;
476 
477 /*
478  * Start recording command output to a variable
479  * When "append" is TRUE append to an existing variable.
480  * Returns OK if successfully completed the setup.  FAIL otherwise.
481  */
482     int
483 var_redir_start(char_u *name, int append)
484 {
485     int		save_emsg;
486     int		err;
487     typval_T	tv;
488 
489     /* Catch a bad name early. */
490     if (!eval_isnamec1(*name))
491     {
492 	emsg(_(e_invarg));
493 	return FAIL;
494     }
495 
496     /* Make a copy of the name, it is used in redir_lval until redir ends. */
497     redir_varname = vim_strsave(name);
498     if (redir_varname == NULL)
499 	return FAIL;
500 
501     redir_lval = ALLOC_CLEAR_ONE(lval_T);
502     if (redir_lval == NULL)
503     {
504 	var_redir_stop();
505 	return FAIL;
506     }
507 
508     /* The output is stored in growarray "redir_ga" until redirection ends. */
509     ga_init2(&redir_ga, (int)sizeof(char), 500);
510 
511     /* Parse the variable name (can be a dict or list entry). */
512     redir_endp = get_lval(redir_varname, NULL, redir_lval, FALSE, FALSE, 0,
513 							     FNE_CHECK_START);
514     if (redir_endp == NULL || redir_lval->ll_name == NULL || *redir_endp != NUL)
515     {
516 	clear_lval(redir_lval);
517 	if (redir_endp != NULL && *redir_endp != NUL)
518 	    /* Trailing characters are present after the variable name */
519 	    emsg(_(e_trailing));
520 	else
521 	    emsg(_(e_invarg));
522 	redir_endp = NULL;  /* don't store a value, only cleanup */
523 	var_redir_stop();
524 	return FAIL;
525     }
526 
527     /* check if we can write to the variable: set it to or append an empty
528      * string */
529     save_emsg = did_emsg;
530     did_emsg = FALSE;
531     tv.v_type = VAR_STRING;
532     tv.vval.v_string = (char_u *)"";
533     if (append)
534 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, FALSE, (char_u *)".");
535     else
536 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, FALSE, (char_u *)"=");
537     clear_lval(redir_lval);
538     err = did_emsg;
539     did_emsg |= save_emsg;
540     if (err)
541     {
542 	redir_endp = NULL;  /* don't store a value, only cleanup */
543 	var_redir_stop();
544 	return FAIL;
545     }
546 
547     return OK;
548 }
549 
550 /*
551  * Append "value[value_len]" to the variable set by var_redir_start().
552  * The actual appending is postponed until redirection ends, because the value
553  * appended may in fact be the string we write to, changing it may cause freed
554  * memory to be used:
555  *   :redir => foo
556  *   :let foo
557  *   :redir END
558  */
559     void
560 var_redir_str(char_u *value, int value_len)
561 {
562     int		len;
563 
564     if (redir_lval == NULL)
565 	return;
566 
567     if (value_len == -1)
568 	len = (int)STRLEN(value);	/* Append the entire string */
569     else
570 	len = value_len;		/* Append only "value_len" characters */
571 
572     if (ga_grow(&redir_ga, len) == OK)
573     {
574 	mch_memmove((char *)redir_ga.ga_data + redir_ga.ga_len, value, len);
575 	redir_ga.ga_len += len;
576     }
577     else
578 	var_redir_stop();
579 }
580 
581 /*
582  * Stop redirecting command output to a variable.
583  * Frees the allocated memory.
584  */
585     void
586 var_redir_stop(void)
587 {
588     typval_T	tv;
589 
590     if (EVALCMD_BUSY)
591     {
592 	redir_lval = NULL;
593 	return;
594     }
595 
596     if (redir_lval != NULL)
597     {
598 	/* If there was no error: assign the text to the variable. */
599 	if (redir_endp != NULL)
600 	{
601 	    ga_append(&redir_ga, NUL);  /* Append the trailing NUL. */
602 	    tv.v_type = VAR_STRING;
603 	    tv.vval.v_string = redir_ga.ga_data;
604 	    /* Call get_lval() again, if it's inside a Dict or List it may
605 	     * have changed. */
606 	    redir_endp = get_lval(redir_varname, NULL, redir_lval,
607 					FALSE, FALSE, 0, FNE_CHECK_START);
608 	    if (redir_endp != NULL && redir_lval->ll_name != NULL)
609 		set_var_lval(redir_lval, redir_endp, &tv, FALSE, FALSE,
610 								(char_u *)".");
611 	    clear_lval(redir_lval);
612 	}
613 
614 	/* free the collected output */
615 	VIM_CLEAR(redir_ga.ga_data);
616 
617 	VIM_CLEAR(redir_lval);
618     }
619     VIM_CLEAR(redir_varname);
620 }
621 
622     int
623 eval_charconvert(
624     char_u	*enc_from,
625     char_u	*enc_to,
626     char_u	*fname_from,
627     char_u	*fname_to)
628 {
629     int		err = FALSE;
630 
631     set_vim_var_string(VV_CC_FROM, enc_from, -1);
632     set_vim_var_string(VV_CC_TO, enc_to, -1);
633     set_vim_var_string(VV_FNAME_IN, fname_from, -1);
634     set_vim_var_string(VV_FNAME_OUT, fname_to, -1);
635     if (eval_to_bool(p_ccv, &err, NULL, FALSE))
636 	err = TRUE;
637     set_vim_var_string(VV_CC_FROM, NULL, -1);
638     set_vim_var_string(VV_CC_TO, NULL, -1);
639     set_vim_var_string(VV_FNAME_IN, NULL, -1);
640     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
641 
642     if (err)
643 	return FAIL;
644     return OK;
645 }
646 
647 # if defined(FEAT_POSTSCRIPT) || defined(PROTO)
648     int
649 eval_printexpr(char_u *fname, char_u *args)
650 {
651     int		err = FALSE;
652 
653     set_vim_var_string(VV_FNAME_IN, fname, -1);
654     set_vim_var_string(VV_CMDARG, args, -1);
655     if (eval_to_bool(p_pexpr, &err, NULL, FALSE))
656 	err = TRUE;
657     set_vim_var_string(VV_FNAME_IN, NULL, -1);
658     set_vim_var_string(VV_CMDARG, NULL, -1);
659 
660     if (err)
661     {
662 	mch_remove(fname);
663 	return FAIL;
664     }
665     return OK;
666 }
667 # endif
668 
669 # if defined(FEAT_DIFF) || defined(PROTO)
670     void
671 eval_diff(
672     char_u	*origfile,
673     char_u	*newfile,
674     char_u	*outfile)
675 {
676     int		err = FALSE;
677 
678     set_vim_var_string(VV_FNAME_IN, origfile, -1);
679     set_vim_var_string(VV_FNAME_NEW, newfile, -1);
680     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
681     (void)eval_to_bool(p_dex, &err, NULL, FALSE);
682     set_vim_var_string(VV_FNAME_IN, NULL, -1);
683     set_vim_var_string(VV_FNAME_NEW, NULL, -1);
684     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
685 }
686 
687     void
688 eval_patch(
689     char_u	*origfile,
690     char_u	*difffile,
691     char_u	*outfile)
692 {
693     int		err;
694 
695     set_vim_var_string(VV_FNAME_IN, origfile, -1);
696     set_vim_var_string(VV_FNAME_DIFF, difffile, -1);
697     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
698     (void)eval_to_bool(p_pex, &err, NULL, FALSE);
699     set_vim_var_string(VV_FNAME_IN, NULL, -1);
700     set_vim_var_string(VV_FNAME_DIFF, NULL, -1);
701     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
702 }
703 # endif
704 
705 /*
706  * Top level evaluation function, returning a boolean.
707  * Sets "error" to TRUE if there was an error.
708  * Return TRUE or FALSE.
709  */
710     int
711 eval_to_bool(
712     char_u	*arg,
713     int		*error,
714     char_u	**nextcmd,
715     int		skip)	    /* only parse, don't execute */
716 {
717     typval_T	tv;
718     varnumber_T	retval = FALSE;
719 
720     if (skip)
721 	++emsg_skip;
722     if (eval0(arg, &tv, nextcmd, !skip) == FAIL)
723 	*error = TRUE;
724     else
725     {
726 	*error = FALSE;
727 	if (!skip)
728 	{
729 	    retval = (tv_get_number_chk(&tv, error) != 0);
730 	    clear_tv(&tv);
731 	}
732     }
733     if (skip)
734 	--emsg_skip;
735 
736     return (int)retval;
737 }
738 
739 /*
740  * Call eval1() and give an error message if not done at a lower level.
741  */
742     static int
743 eval1_emsg(char_u **arg, typval_T *rettv, int evaluate)
744 {
745     char_u	*start = *arg;
746     int		ret;
747     int		did_emsg_before = did_emsg;
748     int		called_emsg_before = called_emsg;
749 
750     ret = eval1(arg, rettv, evaluate);
751     if (ret == FAIL)
752     {
753 	// Report the invalid expression unless the expression evaluation has
754 	// been cancelled due to an aborting error, an interrupt, or an
755 	// exception, or we already gave a more specific error.
756 	// Also check called_emsg for when using assert_fails().
757 	if (!aborting() && did_emsg == did_emsg_before
758 					  && called_emsg == called_emsg_before)
759 	    semsg(_(e_invexpr2), start);
760     }
761     return ret;
762 }
763 
764     int
765 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
766 {
767     char_u	*s;
768     char_u	buf[NUMBUFLEN];
769     funcexe_T	funcexe;
770 
771     if (expr->v_type == VAR_FUNC)
772     {
773 	s = expr->vval.v_string;
774 	if (s == NULL || *s == NUL)
775 	    return FAIL;
776 	vim_memset(&funcexe, 0, sizeof(funcexe));
777 	funcexe.evaluate = TRUE;
778 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
779 	    return FAIL;
780     }
781     else if (expr->v_type == VAR_PARTIAL)
782     {
783 	partial_T   *partial = expr->vval.v_partial;
784 
785 	s = partial_name(partial);
786 	if (s == NULL || *s == NUL)
787 	    return FAIL;
788 	vim_memset(&funcexe, 0, sizeof(funcexe));
789 	funcexe.evaluate = TRUE;
790 	funcexe.partial = partial;
791 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
792 	    return FAIL;
793     }
794     else
795     {
796 	s = tv_get_string_buf_chk(expr, buf);
797 	if (s == NULL)
798 	    return FAIL;
799 	s = skipwhite(s);
800 	if (eval1_emsg(&s, rettv, TRUE) == FAIL)
801 	    return FAIL;
802 	if (*s != NUL)  /* check for trailing chars after expr */
803 	{
804 	    clear_tv(rettv);
805 	    semsg(_(e_invexpr2), s);
806 	    return FAIL;
807 	}
808     }
809     return OK;
810 }
811 
812 /*
813  * Like eval_to_bool() but using a typval_T instead of a string.
814  * Works for string, funcref and partial.
815  */
816     int
817 eval_expr_to_bool(typval_T *expr, int *error)
818 {
819     typval_T	rettv;
820     int		res;
821 
822     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
823     {
824 	*error = TRUE;
825 	return FALSE;
826     }
827     res = (tv_get_number_chk(&rettv, error) != 0);
828     clear_tv(&rettv);
829     return res;
830 }
831 
832 /*
833  * Top level evaluation function, returning a string.  If "skip" is TRUE,
834  * only parsing to "nextcmd" is done, without reporting errors.  Return
835  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
836  */
837     char_u *
838 eval_to_string_skip(
839     char_u	*arg,
840     char_u	**nextcmd,
841     int		skip)	    /* only parse, don't execute */
842 {
843     typval_T	tv;
844     char_u	*retval;
845 
846     if (skip)
847 	++emsg_skip;
848     if (eval0(arg, &tv, nextcmd, !skip) == FAIL || skip)
849 	retval = NULL;
850     else
851     {
852 	retval = vim_strsave(tv_get_string(&tv));
853 	clear_tv(&tv);
854     }
855     if (skip)
856 	--emsg_skip;
857 
858     return retval;
859 }
860 
861 /*
862  * Skip over an expression at "*pp".
863  * Return FAIL for an error, OK otherwise.
864  */
865     int
866 skip_expr(char_u **pp)
867 {
868     typval_T	rettv;
869 
870     *pp = skipwhite(*pp);
871     return eval1(pp, &rettv, FALSE);
872 }
873 
874 /*
875  * Top level evaluation function, returning a string.
876  * When "convert" is TRUE convert a List into a sequence of lines and convert
877  * a Float to a String.
878  * Return pointer to allocated memory, or NULL for failure.
879  */
880     char_u *
881 eval_to_string(
882     char_u	*arg,
883     char_u	**nextcmd,
884     int		convert)
885 {
886     typval_T	tv;
887     char_u	*retval;
888     garray_T	ga;
889 #ifdef FEAT_FLOAT
890     char_u	numbuf[NUMBUFLEN];
891 #endif
892 
893     if (eval0(arg, &tv, nextcmd, TRUE) == FAIL)
894 	retval = NULL;
895     else
896     {
897 	if (convert && tv.v_type == VAR_LIST)
898 	{
899 	    ga_init2(&ga, (int)sizeof(char), 80);
900 	    if (tv.vval.v_list != NULL)
901 	    {
902 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
903 		if (tv.vval.v_list->lv_len > 0)
904 		    ga_append(&ga, NL);
905 	    }
906 	    ga_append(&ga, NUL);
907 	    retval = (char_u *)ga.ga_data;
908 	}
909 #ifdef FEAT_FLOAT
910 	else if (convert && tv.v_type == VAR_FLOAT)
911 	{
912 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
913 	    retval = vim_strsave(numbuf);
914 	}
915 #endif
916 	else
917 	    retval = vim_strsave(tv_get_string(&tv));
918 	clear_tv(&tv);
919     }
920 
921     return retval;
922 }
923 
924 /*
925  * Call eval_to_string() without using current local variables and using
926  * textlock.  When "use_sandbox" is TRUE use the sandbox.
927  */
928     char_u *
929 eval_to_string_safe(
930     char_u	*arg,
931     char_u	**nextcmd,
932     int		use_sandbox)
933 {
934     char_u	*retval;
935     funccal_entry_T funccal_entry;
936 
937     save_funccal(&funccal_entry);
938     if (use_sandbox)
939 	++sandbox;
940     ++textlock;
941     retval = eval_to_string(arg, nextcmd, FALSE);
942     if (use_sandbox)
943 	--sandbox;
944     --textlock;
945     restore_funccal();
946     return retval;
947 }
948 
949 /*
950  * Top level evaluation function, returning a number.
951  * Evaluates "expr" silently.
952  * Returns -1 for an error.
953  */
954     varnumber_T
955 eval_to_number(char_u *expr)
956 {
957     typval_T	rettv;
958     varnumber_T	retval;
959     char_u	*p = skipwhite(expr);
960 
961     ++emsg_off;
962 
963     if (eval1(&p, &rettv, TRUE) == FAIL)
964 	retval = -1;
965     else
966     {
967 	retval = tv_get_number_chk(&rettv, NULL);
968 	clear_tv(&rettv);
969     }
970     --emsg_off;
971 
972     return retval;
973 }
974 
975 /*
976  * Prepare v: variable "idx" to be used.
977  * Save the current typeval in "save_tv".
978  * When not used yet add the variable to the v: hashtable.
979  */
980     void
981 prepare_vimvar(int idx, typval_T *save_tv)
982 {
983     *save_tv = vimvars[idx].vv_tv;
984     if (vimvars[idx].vv_type == VAR_UNKNOWN)
985 	hash_add(&vimvarht, vimvars[idx].vv_di.di_key);
986 }
987 
988 /*
989  * Restore v: variable "idx" to typeval "save_tv".
990  * When no longer defined, remove the variable from the v: hashtable.
991  */
992     void
993 restore_vimvar(int idx, typval_T *save_tv)
994 {
995     hashitem_T	*hi;
996 
997     vimvars[idx].vv_tv = *save_tv;
998     if (vimvars[idx].vv_type == VAR_UNKNOWN)
999     {
1000 	hi = hash_find(&vimvarht, vimvars[idx].vv_di.di_key);
1001 	if (HASHITEM_EMPTY(hi))
1002 	    internal_error("restore_vimvar()");
1003 	else
1004 	    hash_remove(&vimvarht, hi);
1005     }
1006 }
1007 
1008 #if defined(FEAT_SPELL) || defined(PROTO)
1009 /*
1010  * Evaluate an expression to a list with suggestions.
1011  * For the "expr:" part of 'spellsuggest'.
1012  * Returns NULL when there is an error.
1013  */
1014     list_T *
1015 eval_spell_expr(char_u *badword, char_u *expr)
1016 {
1017     typval_T	save_val;
1018     typval_T	rettv;
1019     list_T	*list = NULL;
1020     char_u	*p = skipwhite(expr);
1021 
1022     /* Set "v:val" to the bad word. */
1023     prepare_vimvar(VV_VAL, &save_val);
1024     vimvars[VV_VAL].vv_type = VAR_STRING;
1025     vimvars[VV_VAL].vv_str = badword;
1026     if (p_verbose == 0)
1027 	++emsg_off;
1028 
1029     if (eval1(&p, &rettv, TRUE) == OK)
1030     {
1031 	if (rettv.v_type != VAR_LIST)
1032 	    clear_tv(&rettv);
1033 	else
1034 	    list = rettv.vval.v_list;
1035     }
1036 
1037     if (p_verbose == 0)
1038 	--emsg_off;
1039     restore_vimvar(VV_VAL, &save_val);
1040 
1041     return list;
1042 }
1043 
1044 /*
1045  * "list" is supposed to contain two items: a word and a number.  Return the
1046  * word in "pp" and the number as the return value.
1047  * Return -1 if anything isn't right.
1048  * Used to get the good word and score from the eval_spell_expr() result.
1049  */
1050     int
1051 get_spellword(list_T *list, char_u **pp)
1052 {
1053     listitem_T	*li;
1054 
1055     li = list->lv_first;
1056     if (li == NULL)
1057 	return -1;
1058     *pp = tv_get_string(&li->li_tv);
1059 
1060     li = li->li_next;
1061     if (li == NULL)
1062 	return -1;
1063     return (int)tv_get_number(&li->li_tv);
1064 }
1065 #endif
1066 
1067 /*
1068  * Top level evaluation function.
1069  * Returns an allocated typval_T with the result.
1070  * Returns NULL when there is an error.
1071  */
1072     typval_T *
1073 eval_expr(char_u *arg, char_u **nextcmd)
1074 {
1075     typval_T	*tv;
1076 
1077     tv = ALLOC_ONE(typval_T);
1078     if (tv != NULL && eval0(arg, tv, nextcmd, TRUE) == FAIL)
1079 	VIM_CLEAR(tv);
1080 
1081     return tv;
1082 }
1083 
1084 
1085 /*
1086  * Call some Vim script function and return the result in "*rettv".
1087  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
1088  * should have type VAR_UNKNOWN.
1089  * Returns OK or FAIL.
1090  */
1091     int
1092 call_vim_function(
1093     char_u      *func,
1094     int		argc,
1095     typval_T	*argv,
1096     typval_T	*rettv)
1097 {
1098     int		ret;
1099     funcexe_T	funcexe;
1100 
1101     rettv->v_type = VAR_UNKNOWN;		/* clear_tv() uses this */
1102     vim_memset(&funcexe, 0, sizeof(funcexe));
1103     funcexe.firstline = curwin->w_cursor.lnum;
1104     funcexe.lastline = curwin->w_cursor.lnum;
1105     funcexe.evaluate = TRUE;
1106     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
1107     if (ret == FAIL)
1108 	clear_tv(rettv);
1109 
1110     return ret;
1111 }
1112 
1113 /*
1114  * Call Vim script function "func" and return the result as a number.
1115  * Returns -1 when calling the function fails.
1116  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
1117  * have type VAR_UNKNOWN.
1118  */
1119     varnumber_T
1120 call_func_retnr(
1121     char_u      *func,
1122     int		argc,
1123     typval_T	*argv)
1124 {
1125     typval_T	rettv;
1126     varnumber_T	retval;
1127 
1128     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
1129 	return -1;
1130 
1131     retval = tv_get_number_chk(&rettv, NULL);
1132     clear_tv(&rettv);
1133     return retval;
1134 }
1135 
1136 #if defined(FEAT_CMDL_COMPL) \
1137 	|| defined(FEAT_COMPL_FUNC) || defined(PROTO)
1138 
1139 # if defined(FEAT_CMDL_COMPL) || defined(PROTO)
1140 /*
1141  * Call Vim script function "func" and return the result as a string.
1142  * Returns NULL when calling the function fails.
1143  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
1144  * have type VAR_UNKNOWN.
1145  */
1146     void *
1147 call_func_retstr(
1148     char_u      *func,
1149     int		argc,
1150     typval_T	*argv)
1151 {
1152     typval_T	rettv;
1153     char_u	*retval;
1154 
1155     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
1156 	return NULL;
1157 
1158     retval = vim_strsave(tv_get_string(&rettv));
1159     clear_tv(&rettv);
1160     return retval;
1161 }
1162 # endif
1163 
1164 /*
1165  * Call Vim script function "func" and return the result as a List.
1166  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
1167  * have type VAR_UNKNOWN.
1168  * Returns NULL when there is something wrong.
1169  */
1170     void *
1171 call_func_retlist(
1172     char_u      *func,
1173     int		argc,
1174     typval_T	*argv)
1175 {
1176     typval_T	rettv;
1177 
1178     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
1179 	return NULL;
1180 
1181     if (rettv.v_type != VAR_LIST)
1182     {
1183 	clear_tv(&rettv);
1184 	return NULL;
1185     }
1186 
1187     return rettv.vval.v_list;
1188 }
1189 #endif
1190 
1191 
1192 #ifdef FEAT_FOLDING
1193 /*
1194  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
1195  * it in "*cp".  Doesn't give error messages.
1196  */
1197     int
1198 eval_foldexpr(char_u *arg, int *cp)
1199 {
1200     typval_T	tv;
1201     varnumber_T	retval;
1202     char_u	*s;
1203     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
1204 								   OPT_LOCAL);
1205 
1206     ++emsg_off;
1207     if (use_sandbox)
1208 	++sandbox;
1209     ++textlock;
1210     *cp = NUL;
1211     if (eval0(arg, &tv, NULL, TRUE) == FAIL)
1212 	retval = 0;
1213     else
1214     {
1215 	/* If the result is a number, just return the number. */
1216 	if (tv.v_type == VAR_NUMBER)
1217 	    retval = tv.vval.v_number;
1218 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
1219 	    retval = 0;
1220 	else
1221 	{
1222 	    /* If the result is a string, check if there is a non-digit before
1223 	     * the number. */
1224 	    s = tv.vval.v_string;
1225 	    if (!VIM_ISDIGIT(*s) && *s != '-')
1226 		*cp = *s++;
1227 	    retval = atol((char *)s);
1228 	}
1229 	clear_tv(&tv);
1230     }
1231     --emsg_off;
1232     if (use_sandbox)
1233 	--sandbox;
1234     --textlock;
1235 
1236     return (int)retval;
1237 }
1238 #endif
1239 
1240 /*
1241  * Get a list of lines from a HERE document. The here document is a list of
1242  * lines surrounded by a marker.
1243  *	cmd << {marker}
1244  *	  {line1}
1245  *	  {line2}
1246  *	  ....
1247  *	{marker}
1248  *
1249  * The {marker} is a string. If the optional 'trim' word is supplied before the
1250  * marker, then the leading indentation before the lines (matching the
1251  * indentation in the 'cmd' line) is stripped.
1252  * Returns a List with {lines} or NULL.
1253  */
1254     static list_T *
1255 heredoc_get(exarg_T *eap, char_u *cmd)
1256 {
1257     char_u	*theline;
1258     char_u	*marker;
1259     list_T	*l;
1260     char_u	*p;
1261     int		marker_indent_len = 0;
1262     int		text_indent_len = 0;
1263     char_u	*text_indent = NULL;
1264 
1265     if (eap->getline == NULL)
1266     {
1267 	emsg(_("E991: cannot use =<< here"));
1268 	return NULL;
1269     }
1270 
1271     // Check for the optional 'trim' word before the marker
1272     cmd = skipwhite(cmd);
1273     if (STRNCMP(cmd, "trim", 4) == 0 && (cmd[4] == NUL || VIM_ISWHITE(cmd[4])))
1274     {
1275 	cmd = skipwhite(cmd + 4);
1276 
1277 	// Trim the indentation from all the lines in the here document.
1278 	// The amount of indentation trimmed is the same as the indentation of
1279 	// the first line after the :let command line.  To find the end marker
1280 	// the indent of the :let command line is trimmed.
1281 	p = *eap->cmdlinep;
1282 	while (VIM_ISWHITE(*p))
1283 	{
1284 	    p++;
1285 	    marker_indent_len++;
1286 	}
1287 	text_indent_len = -1;
1288     }
1289 
1290     // The marker is the next word.
1291     if (*cmd != NUL && *cmd != '"')
1292     {
1293 	marker = skipwhite(cmd);
1294 	p = skiptowhite(marker);
1295 	if (*skipwhite(p) != NUL && *skipwhite(p) != '"')
1296 	{
1297 	    emsg(_(e_trailing));
1298 	    return NULL;
1299 	}
1300 	*p = NUL;
1301 	if (vim_islower(*marker))
1302 	{
1303 	    emsg(_("E221: Marker cannot start with lower case letter"));
1304 	    return NULL;
1305 	}
1306     }
1307     else
1308     {
1309 	emsg(_("E172: Missing marker"));
1310 	return NULL;
1311     }
1312 
1313     l = list_alloc();
1314     if (l == NULL)
1315 	return NULL;
1316 
1317     for (;;)
1318     {
1319 	int	mi = 0;
1320 	int	ti = 0;
1321 
1322 	theline = eap->getline(NUL, eap->cookie, 0, FALSE);
1323 	if (theline == NULL)
1324 	{
1325 	    semsg(_("E990: Missing end marker '%s'"), marker);
1326 	    break;
1327 	}
1328 
1329 	// with "trim": skip the indent matching the :let line to find the
1330 	// marker
1331 	if (marker_indent_len > 0
1332 		&& STRNCMP(theline, *eap->cmdlinep, marker_indent_len) == 0)
1333 	    mi = marker_indent_len;
1334 	if (STRCMP(marker, theline + mi) == 0)
1335 	{
1336 	    vim_free(theline);
1337 	    break;
1338 	}
1339 
1340 	if (text_indent_len == -1 && *theline != NUL)
1341 	{
1342 	    // set the text indent from the first line.
1343 	    p = theline;
1344 	    text_indent_len = 0;
1345 	    while (VIM_ISWHITE(*p))
1346 	    {
1347 		p++;
1348 		text_indent_len++;
1349 	    }
1350 	    text_indent = vim_strnsave(theline, text_indent_len);
1351 	}
1352 	// with "trim": skip the indent matching the first line
1353 	if (text_indent != NULL)
1354 	    for (ti = 0; ti < text_indent_len; ++ti)
1355 		if (theline[ti] != text_indent[ti])
1356 		    break;
1357 
1358 	if (list_append_string(l, theline + ti, -1) == FAIL)
1359 	    break;
1360 	vim_free(theline);
1361     }
1362     vim_free(text_indent);
1363 
1364     return l;
1365 }
1366 
1367 /*
1368  * ":let"			list all variable values
1369  * ":let var1 var2"		list variable values
1370  * ":let var = expr"		assignment command.
1371  * ":let var += expr"		assignment command.
1372  * ":let var -= expr"		assignment command.
1373  * ":let var *= expr"		assignment command.
1374  * ":let var /= expr"		assignment command.
1375  * ":let var %= expr"		assignment command.
1376  * ":let var .= expr"		assignment command.
1377  * ":let var ..= expr"		assignment command.
1378  * ":let [var1, var2] = expr"	unpack list.
1379  */
1380     void
1381 ex_let(exarg_T *eap)
1382 {
1383     ex_let_const(eap, FALSE);
1384 }
1385 
1386 /*
1387  * ":const"			list all variable values
1388  * ":const var1 var2"		list variable values
1389  * ":const var = expr"		assignment command.
1390  * ":const [var1, var2] = expr"	unpack list.
1391  */
1392     void
1393 ex_const(exarg_T *eap)
1394 {
1395     ex_let_const(eap, TRUE);
1396 }
1397 
1398     static void
1399 ex_let_const(exarg_T *eap, int is_const)
1400 {
1401     char_u	*arg = eap->arg;
1402     char_u	*expr = NULL;
1403     typval_T	rettv;
1404     int		i;
1405     int		var_count = 0;
1406     int		semicolon = 0;
1407     char_u	op[2];
1408     char_u	*argend;
1409     int		first = TRUE;
1410     int		concat;
1411 
1412     argend = skip_var_list(arg, &var_count, &semicolon);
1413     if (argend == NULL)
1414 	return;
1415     if (argend > arg && argend[-1] == '.')  // for var.='str'
1416 	--argend;
1417     expr = skipwhite(argend);
1418     concat = expr[0] == '.'
1419 	&& ((expr[1] == '=' && current_sctx.sc_version < 2)
1420 		|| (expr[1] == '.' && expr[2] == '='));
1421     if (*expr != '=' && !((vim_strchr((char_u *)"+-*/%", *expr) != NULL
1422 						 && expr[1] == '=') || concat))
1423     {
1424 	/*
1425 	 * ":let" without "=": list variables
1426 	 */
1427 	if (*arg == '[')
1428 	    emsg(_(e_invarg));
1429 	else if (expr[0] == '.')
1430 	    emsg(_("E985: .= is not supported with script version 2"));
1431 	else if (!ends_excmd(*arg))
1432 	    /* ":let var1 var2" */
1433 	    arg = list_arg_vars(eap, arg, &first);
1434 	else if (!eap->skip)
1435 	{
1436 	    /* ":let" */
1437 	    list_glob_vars(&first);
1438 	    list_buf_vars(&first);
1439 	    list_win_vars(&first);
1440 	    list_tab_vars(&first);
1441 	    list_script_vars(&first);
1442 	    list_func_vars(&first);
1443 	    list_vim_vars(&first);
1444 	}
1445 	eap->nextcmd = check_nextcmd(arg);
1446     }
1447     else if (expr[0] == '=' && expr[1] == '<' && expr[2] == '<')
1448     {
1449 	list_T	*l;
1450 
1451 	// HERE document
1452 	l = heredoc_get(eap, expr + 3);
1453 	if (l != NULL)
1454 	{
1455 	    rettv_list_set(&rettv, l);
1456 	    op[0] = '=';
1457 	    op[1] = NUL;
1458 	    (void)ex_let_vars(eap->arg, &rettv, FALSE, semicolon, var_count,
1459 								is_const, op);
1460 	    clear_tv(&rettv);
1461 	}
1462     }
1463     else
1464     {
1465 	op[0] = '=';
1466 	op[1] = NUL;
1467 	if (*expr != '=')
1468 	{
1469 	    if (vim_strchr((char_u *)"+-*/%.", *expr) != NULL)
1470 	    {
1471 		op[0] = *expr;   // +=, -=, *=, /=, %= or .=
1472 		if (expr[0] == '.' && expr[1] == '.') // ..=
1473 		    ++expr;
1474 	    }
1475 	    expr = skipwhite(expr + 2);
1476 	}
1477 	else
1478 	    expr = skipwhite(expr + 1);
1479 
1480 	if (eap->skip)
1481 	    ++emsg_skip;
1482 	i = eval0(expr, &rettv, &eap->nextcmd, !eap->skip);
1483 	if (eap->skip)
1484 	{
1485 	    if (i != FAIL)
1486 		clear_tv(&rettv);
1487 	    --emsg_skip;
1488 	}
1489 	else if (i != FAIL)
1490 	{
1491 	    (void)ex_let_vars(eap->arg, &rettv, FALSE, semicolon, var_count,
1492 								 is_const, op);
1493 	    clear_tv(&rettv);
1494 	}
1495     }
1496 }
1497 
1498 /*
1499  * Assign the typevalue "tv" to the variable or variables at "arg_start".
1500  * Handles both "var" with any type and "[var, var; var]" with a list type.
1501  * When "op" is not NULL it points to a string with characters that
1502  * must appear after the variable(s).  Use "+", "-" or "." for add, subtract
1503  * or concatenate.
1504  * Returns OK or FAIL;
1505  */
1506     static int
1507 ex_let_vars(
1508     char_u	*arg_start,
1509     typval_T	*tv,
1510     int		copy,		// copy values from "tv", don't move
1511     int		semicolon,	// from skip_var_list()
1512     int		var_count,	// from skip_var_list()
1513     int		is_const,	// lock variables for const
1514     char_u	*op)
1515 {
1516     char_u	*arg = arg_start;
1517     list_T	*l;
1518     int		i;
1519     listitem_T	*item;
1520     typval_T	ltv;
1521 
1522     if (*arg != '[')
1523     {
1524 	/*
1525 	 * ":let var = expr" or ":for var in list"
1526 	 */
1527 	if (ex_let_one(arg, tv, copy, is_const, op, op) == NULL)
1528 	    return FAIL;
1529 	return OK;
1530     }
1531 
1532     /*
1533      * ":let [v1, v2] = list" or ":for [v1, v2] in listlist"
1534      */
1535     if (tv->v_type != VAR_LIST || (l = tv->vval.v_list) == NULL)
1536     {
1537 	emsg(_(e_listreq));
1538 	return FAIL;
1539     }
1540 
1541     i = list_len(l);
1542     if (semicolon == 0 && var_count < i)
1543     {
1544 	emsg(_("E687: Less targets than List items"));
1545 	return FAIL;
1546     }
1547     if (var_count - semicolon > i)
1548     {
1549 	emsg(_("E688: More targets than List items"));
1550 	return FAIL;
1551     }
1552 
1553     item = l->lv_first;
1554     while (*arg != ']')
1555     {
1556 	arg = skipwhite(arg + 1);
1557 	arg = ex_let_one(arg, &item->li_tv, TRUE, is_const,
1558 							  (char_u *)",;]", op);
1559 	item = item->li_next;
1560 	if (arg == NULL)
1561 	    return FAIL;
1562 
1563 	arg = skipwhite(arg);
1564 	if (*arg == ';')
1565 	{
1566 	    /* Put the rest of the list (may be empty) in the var after ';'.
1567 	     * Create a new list for this. */
1568 	    l = list_alloc();
1569 	    if (l == NULL)
1570 		return FAIL;
1571 	    while (item != NULL)
1572 	    {
1573 		list_append_tv(l, &item->li_tv);
1574 		item = item->li_next;
1575 	    }
1576 
1577 	    ltv.v_type = VAR_LIST;
1578 	    ltv.v_lock = 0;
1579 	    ltv.vval.v_list = l;
1580 	    l->lv_refcount = 1;
1581 
1582 	    arg = ex_let_one(skipwhite(arg + 1), &ltv, FALSE, is_const,
1583 							    (char_u *)"]", op);
1584 	    clear_tv(&ltv);
1585 	    if (arg == NULL)
1586 		return FAIL;
1587 	    break;
1588 	}
1589 	else if (*arg != ',' && *arg != ']')
1590 	{
1591 	    internal_error("ex_let_vars()");
1592 	    return FAIL;
1593 	}
1594     }
1595 
1596     return OK;
1597 }
1598 
1599 /*
1600  * Skip over assignable variable "var" or list of variables "[var, var]".
1601  * Used for ":let varvar = expr" and ":for varvar in expr".
1602  * For "[var, var]" increment "*var_count" for each variable.
1603  * for "[var, var; var]" set "semicolon".
1604  * Return NULL for an error.
1605  */
1606     static char_u *
1607 skip_var_list(
1608     char_u	*arg,
1609     int		*var_count,
1610     int		*semicolon)
1611 {
1612     char_u	*p, *s;
1613 
1614     if (*arg == '[')
1615     {
1616 	/* "[var, var]": find the matching ']'. */
1617 	p = arg;
1618 	for (;;)
1619 	{
1620 	    p = skipwhite(p + 1);	/* skip whites after '[', ';' or ',' */
1621 	    s = skip_var_one(p);
1622 	    if (s == p)
1623 	    {
1624 		semsg(_(e_invarg2), p);
1625 		return NULL;
1626 	    }
1627 	    ++*var_count;
1628 
1629 	    p = skipwhite(s);
1630 	    if (*p == ']')
1631 		break;
1632 	    else if (*p == ';')
1633 	    {
1634 		if (*semicolon == 1)
1635 		{
1636 		    emsg(_("Double ; in list of variables"));
1637 		    return NULL;
1638 		}
1639 		*semicolon = 1;
1640 	    }
1641 	    else if (*p != ',')
1642 	    {
1643 		semsg(_(e_invarg2), p);
1644 		return NULL;
1645 	    }
1646 	}
1647 	return p + 1;
1648     }
1649     else
1650 	return skip_var_one(arg);
1651 }
1652 
1653 /*
1654  * Skip one (assignable) variable name, including @r, $VAR, &option, d.key,
1655  * l[idx].
1656  */
1657     static char_u *
1658 skip_var_one(char_u *arg)
1659 {
1660     if (*arg == '@' && arg[1] != NUL)
1661 	return arg + 2;
1662     return find_name_end(*arg == '$' || *arg == '&' ? arg + 1 : arg,
1663 				   NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1664 }
1665 
1666 /*
1667  * List variables for hashtab "ht" with prefix "prefix".
1668  * If "empty" is TRUE also list NULL strings as empty strings.
1669  */
1670     void
1671 list_hashtable_vars(
1672     hashtab_T	*ht,
1673     char	*prefix,
1674     int		empty,
1675     int		*first)
1676 {
1677     hashitem_T	*hi;
1678     dictitem_T	*di;
1679     int		todo;
1680     char_u	buf[IOSIZE];
1681 
1682     todo = (int)ht->ht_used;
1683     for (hi = ht->ht_array; todo > 0 && !got_int; ++hi)
1684     {
1685 	if (!HASHITEM_EMPTY(hi))
1686 	{
1687 	    --todo;
1688 	    di = HI2DI(hi);
1689 
1690 	    // apply :filter /pat/ to variable name
1691 	    vim_strncpy((char_u *)buf, (char_u *)prefix, IOSIZE - 1);
1692 	    vim_strcat((char_u *)buf, di->di_key, IOSIZE);
1693 	    if (message_filtered(buf))
1694 		continue;
1695 
1696 	    if (empty || di->di_tv.v_type != VAR_STRING
1697 					   || di->di_tv.vval.v_string != NULL)
1698 		list_one_var(di, prefix, first);
1699 	}
1700     }
1701 }
1702 
1703 /*
1704  * List global variables.
1705  */
1706     static void
1707 list_glob_vars(int *first)
1708 {
1709     list_hashtable_vars(&globvarht, "", TRUE, first);
1710 }
1711 
1712 /*
1713  * List buffer variables.
1714  */
1715     static void
1716 list_buf_vars(int *first)
1717 {
1718     list_hashtable_vars(&curbuf->b_vars->dv_hashtab, "b:", TRUE, first);
1719 }
1720 
1721 /*
1722  * List window variables.
1723  */
1724     static void
1725 list_win_vars(int *first)
1726 {
1727     list_hashtable_vars(&curwin->w_vars->dv_hashtab, "w:", TRUE, first);
1728 }
1729 
1730 /*
1731  * List tab page variables.
1732  */
1733     static void
1734 list_tab_vars(int *first)
1735 {
1736     list_hashtable_vars(&curtab->tp_vars->dv_hashtab, "t:", TRUE, first);
1737 }
1738 
1739 /*
1740  * List Vim variables.
1741  */
1742     static void
1743 list_vim_vars(int *first)
1744 {
1745     list_hashtable_vars(&vimvarht, "v:", FALSE, first);
1746 }
1747 
1748 /*
1749  * List script-local variables, if there is a script.
1750  */
1751     static void
1752 list_script_vars(int *first)
1753 {
1754     if (current_sctx.sc_sid > 0 && current_sctx.sc_sid <= ga_scripts.ga_len)
1755 	list_hashtable_vars(&SCRIPT_VARS(current_sctx.sc_sid),
1756 							   "s:", FALSE, first);
1757 }
1758 
1759 /*
1760  * List variables in "arg".
1761  */
1762     static char_u *
1763 list_arg_vars(exarg_T *eap, char_u *arg, int *first)
1764 {
1765     int		error = FALSE;
1766     int		len;
1767     char_u	*name;
1768     char_u	*name_start;
1769     char_u	*arg_subsc;
1770     char_u	*tofree;
1771     typval_T    tv;
1772 
1773     while (!ends_excmd(*arg) && !got_int)
1774     {
1775 	if (error || eap->skip)
1776 	{
1777 	    arg = find_name_end(arg, NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1778 	    if (!VIM_ISWHITE(*arg) && !ends_excmd(*arg))
1779 	    {
1780 		emsg_severe = TRUE;
1781 		emsg(_(e_trailing));
1782 		break;
1783 	    }
1784 	}
1785 	else
1786 	{
1787 	    /* get_name_len() takes care of expanding curly braces */
1788 	    name_start = name = arg;
1789 	    len = get_name_len(&arg, &tofree, TRUE, TRUE);
1790 	    if (len <= 0)
1791 	    {
1792 		/* This is mainly to keep test 49 working: when expanding
1793 		 * curly braces fails overrule the exception error message. */
1794 		if (len < 0 && !aborting())
1795 		{
1796 		    emsg_severe = TRUE;
1797 		    semsg(_(e_invarg2), arg);
1798 		    break;
1799 		}
1800 		error = TRUE;
1801 	    }
1802 	    else
1803 	    {
1804 		if (tofree != NULL)
1805 		    name = tofree;
1806 		if (get_var_tv(name, len, &tv, NULL, TRUE, FALSE) == FAIL)
1807 		    error = TRUE;
1808 		else
1809 		{
1810 		    /* handle d.key, l[idx], f(expr) */
1811 		    arg_subsc = arg;
1812 		    if (handle_subscript(&arg, &tv, TRUE, TRUE) == FAIL)
1813 			error = TRUE;
1814 		    else
1815 		    {
1816 			if (arg == arg_subsc && len == 2 && name[1] == ':')
1817 			{
1818 			    switch (*name)
1819 			    {
1820 				case 'g': list_glob_vars(first); break;
1821 				case 'b': list_buf_vars(first); break;
1822 				case 'w': list_win_vars(first); break;
1823 				case 't': list_tab_vars(first); break;
1824 				case 'v': list_vim_vars(first); break;
1825 				case 's': list_script_vars(first); break;
1826 				case 'l': list_func_vars(first); break;
1827 				default:
1828 					  semsg(_("E738: Can't list variables for %s"), name);
1829 			    }
1830 			}
1831 			else
1832 			{
1833 			    char_u	numbuf[NUMBUFLEN];
1834 			    char_u	*tf;
1835 			    int		c;
1836 			    char_u	*s;
1837 
1838 			    s = echo_string(&tv, &tf, numbuf, 0);
1839 			    c = *arg;
1840 			    *arg = NUL;
1841 			    list_one_var_a("",
1842 				    arg == arg_subsc ? name : name_start,
1843 				    tv.v_type,
1844 				    s == NULL ? (char_u *)"" : s,
1845 				    first);
1846 			    *arg = c;
1847 			    vim_free(tf);
1848 			}
1849 			clear_tv(&tv);
1850 		    }
1851 		}
1852 	    }
1853 
1854 	    vim_free(tofree);
1855 	}
1856 
1857 	arg = skipwhite(arg);
1858     }
1859 
1860     return arg;
1861 }
1862 
1863 /*
1864  * Set one item of ":let var = expr" or ":let [v1, v2] = list" to its value.
1865  * Returns a pointer to the char just after the var name.
1866  * Returns NULL if there is an error.
1867  */
1868     static char_u *
1869 ex_let_one(
1870     char_u	*arg,		// points to variable name
1871     typval_T	*tv,		// value to assign to variable
1872     int		copy,		// copy value from "tv"
1873     int		is_const,	// lock variable for const
1874     char_u	*endchars,	// valid chars after variable name  or NULL
1875     char_u	*op)		// "+", "-", "."  or NULL
1876 {
1877     int		c1;
1878     char_u	*name;
1879     char_u	*p;
1880     char_u	*arg_end = NULL;
1881     int		len;
1882     int		opt_flags;
1883     char_u	*tofree = NULL;
1884 
1885     /*
1886      * ":let $VAR = expr": Set environment variable.
1887      */
1888     if (*arg == '$')
1889     {
1890 	if (is_const)
1891 	{
1892 	    emsg(_("E996: Cannot lock an environment variable"));
1893 	    return NULL;
1894 	}
1895 	/* Find the end of the name. */
1896 	++arg;
1897 	name = arg;
1898 	len = get_env_len(&arg);
1899 	if (len == 0)
1900 	    semsg(_(e_invarg2), name - 1);
1901 	else
1902 	{
1903 	    if (op != NULL && vim_strchr((char_u *)"+-*/%", *op) != NULL)
1904 		semsg(_(e_letwrong), op);
1905 	    else if (endchars != NULL
1906 			     && vim_strchr(endchars, *skipwhite(arg)) == NULL)
1907 		emsg(_(e_letunexp));
1908 	    else if (!check_secure())
1909 	    {
1910 		c1 = name[len];
1911 		name[len] = NUL;
1912 		p = tv_get_string_chk(tv);
1913 		if (p != NULL && op != NULL && *op == '.')
1914 		{
1915 		    int	    mustfree = FALSE;
1916 		    char_u  *s = vim_getenv(name, &mustfree);
1917 
1918 		    if (s != NULL)
1919 		    {
1920 			p = tofree = concat_str(s, p);
1921 			if (mustfree)
1922 			    vim_free(s);
1923 		    }
1924 		}
1925 		if (p != NULL)
1926 		{
1927 		    vim_setenv(name, p);
1928 		    if (STRICMP(name, "HOME") == 0)
1929 			init_homedir();
1930 		    else if (didset_vim && STRICMP(name, "VIM") == 0)
1931 			didset_vim = FALSE;
1932 		    else if (didset_vimruntime
1933 					&& STRICMP(name, "VIMRUNTIME") == 0)
1934 			didset_vimruntime = FALSE;
1935 		    arg_end = arg;
1936 		}
1937 		name[len] = c1;
1938 		vim_free(tofree);
1939 	    }
1940 	}
1941     }
1942 
1943     /*
1944      * ":let &option = expr": Set option value.
1945      * ":let &l:option = expr": Set local option value.
1946      * ":let &g:option = expr": Set global option value.
1947      */
1948     else if (*arg == '&')
1949     {
1950 	if (is_const)
1951 	{
1952 	    emsg(_("E996: Cannot lock an option"));
1953 	    return NULL;
1954 	}
1955 	/* Find the end of the name. */
1956 	p = find_option_end(&arg, &opt_flags);
1957 	if (p == NULL || (endchars != NULL
1958 			      && vim_strchr(endchars, *skipwhite(p)) == NULL))
1959 	    emsg(_(e_letunexp));
1960 	else
1961 	{
1962 	    long	n;
1963 	    int		opt_type;
1964 	    long	numval;
1965 	    char_u	*stringval = NULL;
1966 	    char_u	*s;
1967 
1968 	    c1 = *p;
1969 	    *p = NUL;
1970 
1971 	    n = (long)tv_get_number(tv);
1972 	    s = tv_get_string_chk(tv);	    /* != NULL if number or string */
1973 	    if (s != NULL && op != NULL && *op != '=')
1974 	    {
1975 		opt_type = get_option_value(arg, &numval,
1976 						       &stringval, opt_flags);
1977 		if ((opt_type == 1 && *op == '.')
1978 			|| (opt_type == 0 && *op != '.'))
1979 		{
1980 		    semsg(_(e_letwrong), op);
1981 		    s = NULL;  // don't set the value
1982 		}
1983 		else
1984 		{
1985 		    if (opt_type == 1)  // number
1986 		    {
1987 			switch (*op)
1988 			{
1989 			    case '+': n = numval + n; break;
1990 			    case '-': n = numval - n; break;
1991 			    case '*': n = numval * n; break;
1992 			    case '/': n = (long)num_divide(numval, n); break;
1993 			    case '%': n = (long)num_modulus(numval, n); break;
1994 			}
1995 		    }
1996 		    else if (opt_type == 0 && stringval != NULL) // string
1997 		    {
1998 			s = concat_str(stringval, s);
1999 			vim_free(stringval);
2000 			stringval = s;
2001 		    }
2002 		}
2003 	    }
2004 	    if (s != NULL)
2005 	    {
2006 		set_option_value(arg, n, s, opt_flags);
2007 		arg_end = p;
2008 	    }
2009 	    *p = c1;
2010 	    vim_free(stringval);
2011 	}
2012     }
2013 
2014     /*
2015      * ":let @r = expr": Set register contents.
2016      */
2017     else if (*arg == '@')
2018     {
2019 	if (is_const)
2020 	{
2021 	    emsg(_("E996: Cannot lock a register"));
2022 	    return NULL;
2023 	}
2024 	++arg;
2025 	if (op != NULL && vim_strchr((char_u *)"+-*/%", *op) != NULL)
2026 	    semsg(_(e_letwrong), op);
2027 	else if (endchars != NULL
2028 			 && vim_strchr(endchars, *skipwhite(arg + 1)) == NULL)
2029 	    emsg(_(e_letunexp));
2030 	else
2031 	{
2032 	    char_u	*ptofree = NULL;
2033 	    char_u	*s;
2034 
2035 	    p = tv_get_string_chk(tv);
2036 	    if (p != NULL && op != NULL && *op == '.')
2037 	    {
2038 		s = get_reg_contents(*arg == '@' ? '"' : *arg, GREG_EXPR_SRC);
2039 		if (s != NULL)
2040 		{
2041 		    p = ptofree = concat_str(s, p);
2042 		    vim_free(s);
2043 		}
2044 	    }
2045 	    if (p != NULL)
2046 	    {
2047 		write_reg_contents(*arg == '@' ? '"' : *arg, p, -1, FALSE);
2048 		arg_end = arg + 1;
2049 	    }
2050 	    vim_free(ptofree);
2051 	}
2052     }
2053 
2054     /*
2055      * ":let var = expr": Set internal variable.
2056      * ":let {expr} = expr": Idem, name made with curly braces
2057      */
2058     else if (eval_isnamec1(*arg) || *arg == '{')
2059     {
2060 	lval_T	lv;
2061 
2062 	p = get_lval(arg, tv, &lv, FALSE, FALSE, 0, FNE_CHECK_START);
2063 	if (p != NULL && lv.ll_name != NULL)
2064 	{
2065 	    if (endchars != NULL && vim_strchr(endchars, *skipwhite(p)) == NULL)
2066 		emsg(_(e_letunexp));
2067 	    else
2068 	    {
2069 		set_var_lval(&lv, p, tv, copy, is_const, op);
2070 		arg_end = p;
2071 	    }
2072 	}
2073 	clear_lval(&lv);
2074     }
2075 
2076     else
2077 	semsg(_(e_invarg2), arg);
2078 
2079     return arg_end;
2080 }
2081 
2082 /*
2083  * Get an lval: variable, Dict item or List item that can be assigned a value
2084  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
2085  * "name.key", "name.key[expr]" etc.
2086  * Indexing only works if "name" is an existing List or Dictionary.
2087  * "name" points to the start of the name.
2088  * If "rettv" is not NULL it points to the value to be assigned.
2089  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
2090  * wrong; must end in space or cmd separator.
2091  *
2092  * flags:
2093  *  GLV_QUIET:       do not give error messages
2094  *  GLV_READ_ONLY:   will not change the variable
2095  *  GLV_NO_AUTOLOAD: do not use script autoloading
2096  *
2097  * Returns a pointer to just after the name, including indexes.
2098  * When an evaluation error occurs "lp->ll_name" is NULL;
2099  * Returns NULL for a parsing error.  Still need to free items in "lp"!
2100  */
2101     char_u *
2102 get_lval(
2103     char_u	*name,
2104     typval_T	*rettv,
2105     lval_T	*lp,
2106     int		unlet,
2107     int		skip,
2108     int		flags,	    /* GLV_ values */
2109     int		fne_flags)  /* flags for find_name_end() */
2110 {
2111     char_u	*p;
2112     char_u	*expr_start, *expr_end;
2113     int		cc;
2114     dictitem_T	*v;
2115     typval_T	var1;
2116     typval_T	var2;
2117     int		empty1 = FALSE;
2118     listitem_T	*ni;
2119     char_u	*key = NULL;
2120     int		len;
2121     hashtab_T	*ht;
2122     int		quiet = flags & GLV_QUIET;
2123 
2124     /* Clear everything in "lp". */
2125     vim_memset(lp, 0, sizeof(lval_T));
2126 
2127     if (skip)
2128     {
2129 	/* When skipping just find the end of the name. */
2130 	lp->ll_name = name;
2131 	return find_name_end(name, NULL, NULL, FNE_INCL_BR | fne_flags);
2132     }
2133 
2134     /* Find the end of the name. */
2135     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
2136     if (expr_start != NULL)
2137     {
2138 	/* Don't expand the name when we already know there is an error. */
2139 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
2140 						    && *p != '[' && *p != '.')
2141 	{
2142 	    emsg(_(e_trailing));
2143 	    return NULL;
2144 	}
2145 
2146 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
2147 	if (lp->ll_exp_name == NULL)
2148 	{
2149 	    /* Report an invalid expression in braces, unless the
2150 	     * expression evaluation has been cancelled due to an
2151 	     * aborting error, an interrupt, or an exception. */
2152 	    if (!aborting() && !quiet)
2153 	    {
2154 		emsg_severe = TRUE;
2155 		semsg(_(e_invarg2), name);
2156 		return NULL;
2157 	    }
2158 	}
2159 	lp->ll_name = lp->ll_exp_name;
2160     }
2161     else
2162 	lp->ll_name = name;
2163 
2164     /* Without [idx] or .key we are done. */
2165     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
2166 	return p;
2167 
2168     cc = *p;
2169     *p = NUL;
2170     /* Only pass &ht when we would write to the variable, it prevents autoload
2171      * as well. */
2172     v = find_var(lp->ll_name, (flags & GLV_READ_ONLY) ? NULL : &ht,
2173 						      flags & GLV_NO_AUTOLOAD);
2174     if (v == NULL && !quiet)
2175 	semsg(_(e_undefvar), lp->ll_name);
2176     *p = cc;
2177     if (v == NULL)
2178 	return NULL;
2179 
2180     /*
2181      * Loop until no more [idx] or .key is following.
2182      */
2183     lp->ll_tv = &v->di_tv;
2184     var1.v_type = VAR_UNKNOWN;
2185     var2.v_type = VAR_UNKNOWN;
2186     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
2187     {
2188 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
2189 		&& !(lp->ll_tv->v_type == VAR_DICT
2190 					   && lp->ll_tv->vval.v_dict != NULL)
2191 		&& !(lp->ll_tv->v_type == VAR_BLOB
2192 					   && lp->ll_tv->vval.v_blob != NULL))
2193 	{
2194 	    if (!quiet)
2195 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
2196 	    return NULL;
2197 	}
2198 	if (lp->ll_range)
2199 	{
2200 	    if (!quiet)
2201 		emsg(_("E708: [:] must come last"));
2202 	    return NULL;
2203 	}
2204 
2205 	len = -1;
2206 	if (*p == '.')
2207 	{
2208 	    key = p + 1;
2209 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
2210 		;
2211 	    if (len == 0)
2212 	    {
2213 		if (!quiet)
2214 		    emsg(_(e_emptykey));
2215 		return NULL;
2216 	    }
2217 	    p = key + len;
2218 	}
2219 	else
2220 	{
2221 	    /* Get the index [expr] or the first index [expr: ]. */
2222 	    p = skipwhite(p + 1);
2223 	    if (*p == ':')
2224 		empty1 = TRUE;
2225 	    else
2226 	    {
2227 		empty1 = FALSE;
2228 		if (eval1(&p, &var1, TRUE) == FAIL)	/* recursive! */
2229 		    return NULL;
2230 		if (tv_get_string_chk(&var1) == NULL)
2231 		{
2232 		    /* not a number or string */
2233 		    clear_tv(&var1);
2234 		    return NULL;
2235 		}
2236 	    }
2237 
2238 	    /* Optionally get the second index [ :expr]. */
2239 	    if (*p == ':')
2240 	    {
2241 		if (lp->ll_tv->v_type == VAR_DICT)
2242 		{
2243 		    if (!quiet)
2244 			emsg(_(e_dictrange));
2245 		    clear_tv(&var1);
2246 		    return NULL;
2247 		}
2248 		if (rettv != NULL
2249 			&& !(rettv->v_type == VAR_LIST
2250 						 && rettv->vval.v_list != NULL)
2251 			&& !(rettv->v_type == VAR_BLOB
2252 						&& rettv->vval.v_blob != NULL))
2253 		{
2254 		    if (!quiet)
2255 			emsg(_("E709: [:] requires a List or Blob value"));
2256 		    clear_tv(&var1);
2257 		    return NULL;
2258 		}
2259 		p = skipwhite(p + 1);
2260 		if (*p == ']')
2261 		    lp->ll_empty2 = TRUE;
2262 		else
2263 		{
2264 		    lp->ll_empty2 = FALSE;
2265 		    if (eval1(&p, &var2, TRUE) == FAIL)	/* recursive! */
2266 		    {
2267 			clear_tv(&var1);
2268 			return NULL;
2269 		    }
2270 		    if (tv_get_string_chk(&var2) == NULL)
2271 		    {
2272 			/* not a number or string */
2273 			clear_tv(&var1);
2274 			clear_tv(&var2);
2275 			return NULL;
2276 		    }
2277 		}
2278 		lp->ll_range = TRUE;
2279 	    }
2280 	    else
2281 		lp->ll_range = FALSE;
2282 
2283 	    if (*p != ']')
2284 	    {
2285 		if (!quiet)
2286 		    emsg(_(e_missbrac));
2287 		clear_tv(&var1);
2288 		clear_tv(&var2);
2289 		return NULL;
2290 	    }
2291 
2292 	    /* Skip to past ']'. */
2293 	    ++p;
2294 	}
2295 
2296 	if (lp->ll_tv->v_type == VAR_DICT)
2297 	{
2298 	    if (len == -1)
2299 	    {
2300 		/* "[key]": get key from "var1" */
2301 		key = tv_get_string_chk(&var1);	/* is number or string */
2302 		if (key == NULL)
2303 		{
2304 		    clear_tv(&var1);
2305 		    return NULL;
2306 		}
2307 	    }
2308 	    lp->ll_list = NULL;
2309 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
2310 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
2311 
2312 	    /* When assigning to a scope dictionary check that a function and
2313 	     * variable name is valid (only variable name unless it is l: or
2314 	     * g: dictionary). Disallow overwriting a builtin function. */
2315 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
2316 	    {
2317 		int prevval;
2318 		int wrong;
2319 
2320 		if (len != -1)
2321 		{
2322 		    prevval = key[len];
2323 		    key[len] = NUL;
2324 		}
2325 		else
2326 		    prevval = 0; /* avoid compiler warning */
2327 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
2328 			       && rettv->v_type == VAR_FUNC
2329 			       && var_check_func_name(key, lp->ll_di == NULL))
2330 			|| !valid_varname(key);
2331 		if (len != -1)
2332 		    key[len] = prevval;
2333 		if (wrong)
2334 		    return NULL;
2335 	    }
2336 
2337 	    if (lp->ll_di == NULL)
2338 	    {
2339 		// Can't add "v:" or "a:" variable.
2340 		if (lp->ll_dict == &vimvardict
2341 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
2342 		{
2343 		    semsg(_(e_illvar), name);
2344 		    clear_tv(&var1);
2345 		    return NULL;
2346 		}
2347 
2348 		// Key does not exist in dict: may need to add it.
2349 		if (*p == '[' || *p == '.' || unlet)
2350 		{
2351 		    if (!quiet)
2352 			semsg(_(e_dictkey), key);
2353 		    clear_tv(&var1);
2354 		    return NULL;
2355 		}
2356 		if (len == -1)
2357 		    lp->ll_newkey = vim_strsave(key);
2358 		else
2359 		    lp->ll_newkey = vim_strnsave(key, len);
2360 		clear_tv(&var1);
2361 		if (lp->ll_newkey == NULL)
2362 		    p = NULL;
2363 		break;
2364 	    }
2365 	    /* existing variable, need to check if it can be changed */
2366 	    else if ((flags & GLV_READ_ONLY) == 0
2367 			     && var_check_ro(lp->ll_di->di_flags, name, FALSE))
2368 	    {
2369 		clear_tv(&var1);
2370 		return NULL;
2371 	    }
2372 
2373 	    clear_tv(&var1);
2374 	    lp->ll_tv = &lp->ll_di->di_tv;
2375 	}
2376 	else if (lp->ll_tv->v_type == VAR_BLOB)
2377 	{
2378 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
2379 
2380 	    /*
2381 	     * Get the number and item for the only or first index of the List.
2382 	     */
2383 	    if (empty1)
2384 		lp->ll_n1 = 0;
2385 	    else
2386 		// is number or string
2387 		lp->ll_n1 = (long)tv_get_number(&var1);
2388 	    clear_tv(&var1);
2389 
2390 	    if (lp->ll_n1 < 0
2391 		    || lp->ll_n1 > bloblen
2392 		    || (lp->ll_range && lp->ll_n1 == bloblen))
2393 	    {
2394 		if (!quiet)
2395 		    semsg(_(e_blobidx), lp->ll_n1);
2396 		clear_tv(&var2);
2397 		return NULL;
2398 	    }
2399 	    if (lp->ll_range && !lp->ll_empty2)
2400 	    {
2401 		lp->ll_n2 = (long)tv_get_number(&var2);
2402 		clear_tv(&var2);
2403 		if (lp->ll_n2 < 0
2404 			|| lp->ll_n2 >= bloblen
2405 			|| lp->ll_n2 < lp->ll_n1)
2406 		{
2407 		    if (!quiet)
2408 			semsg(_(e_blobidx), lp->ll_n2);
2409 		    return NULL;
2410 		}
2411 	    }
2412 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
2413 	    lp->ll_tv = NULL;
2414 	    break;
2415 	}
2416 	else
2417 	{
2418 	    /*
2419 	     * Get the number and item for the only or first index of the List.
2420 	     */
2421 	    if (empty1)
2422 		lp->ll_n1 = 0;
2423 	    else
2424 		/* is number or string */
2425 		lp->ll_n1 = (long)tv_get_number(&var1);
2426 	    clear_tv(&var1);
2427 
2428 	    lp->ll_dict = NULL;
2429 	    lp->ll_list = lp->ll_tv->vval.v_list;
2430 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2431 	    if (lp->ll_li == NULL)
2432 	    {
2433 		if (lp->ll_n1 < 0)
2434 		{
2435 		    lp->ll_n1 = 0;
2436 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2437 		}
2438 	    }
2439 	    if (lp->ll_li == NULL)
2440 	    {
2441 		clear_tv(&var2);
2442 		if (!quiet)
2443 		    semsg(_(e_listidx), lp->ll_n1);
2444 		return NULL;
2445 	    }
2446 
2447 	    /*
2448 	     * May need to find the item or absolute index for the second
2449 	     * index of a range.
2450 	     * When no index given: "lp->ll_empty2" is TRUE.
2451 	     * Otherwise "lp->ll_n2" is set to the second index.
2452 	     */
2453 	    if (lp->ll_range && !lp->ll_empty2)
2454 	    {
2455 		lp->ll_n2 = (long)tv_get_number(&var2);
2456 						    /* is number or string */
2457 		clear_tv(&var2);
2458 		if (lp->ll_n2 < 0)
2459 		{
2460 		    ni = list_find(lp->ll_list, lp->ll_n2);
2461 		    if (ni == NULL)
2462 		    {
2463 			if (!quiet)
2464 			    semsg(_(e_listidx), lp->ll_n2);
2465 			return NULL;
2466 		    }
2467 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
2468 		}
2469 
2470 		/* Check that lp->ll_n2 isn't before lp->ll_n1. */
2471 		if (lp->ll_n1 < 0)
2472 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
2473 		if (lp->ll_n2 < lp->ll_n1)
2474 		{
2475 		    if (!quiet)
2476 			semsg(_(e_listidx), lp->ll_n2);
2477 		    return NULL;
2478 		}
2479 	    }
2480 
2481 	    lp->ll_tv = &lp->ll_li->li_tv;
2482 	}
2483     }
2484 
2485     clear_tv(&var1);
2486     return p;
2487 }
2488 
2489 /*
2490  * Clear lval "lp" that was filled by get_lval().
2491  */
2492     void
2493 clear_lval(lval_T *lp)
2494 {
2495     vim_free(lp->ll_exp_name);
2496     vim_free(lp->ll_newkey);
2497 }
2498 
2499 /*
2500  * Set a variable that was parsed by get_lval() to "rettv".
2501  * "endp" points to just after the parsed name.
2502  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
2503  * "%" for "%=", "." for ".=" or "=" for "=".
2504  */
2505     static void
2506 set_var_lval(
2507     lval_T	*lp,
2508     char_u	*endp,
2509     typval_T	*rettv,
2510     int		copy,
2511     int		is_const,    // Disallow to modify existing variable for :const
2512     char_u	*op)
2513 {
2514     int		cc;
2515     listitem_T	*ri;
2516     dictitem_T	*di;
2517 
2518     if (lp->ll_tv == NULL)
2519     {
2520 	cc = *endp;
2521 	*endp = NUL;
2522 	if (lp->ll_blob != NULL)
2523 	{
2524 	    int	    error = FALSE, val;
2525 
2526 	    if (op != NULL && *op != '=')
2527 	    {
2528 		semsg(_(e_letwrong), op);
2529 		return;
2530 	    }
2531 
2532 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
2533 	    {
2534 		int	il, ir;
2535 
2536 		if (lp->ll_empty2)
2537 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
2538 
2539 		if (lp->ll_n2 - lp->ll_n1 + 1 != blob_len(rettv->vval.v_blob))
2540 		{
2541 		    emsg(_("E972: Blob value does not have the right number of bytes"));
2542 		    return;
2543 		}
2544 		if (lp->ll_empty2)
2545 		    lp->ll_n2 = blob_len(lp->ll_blob);
2546 
2547 		ir = 0;
2548 		for (il = lp->ll_n1; il <= lp->ll_n2; il++)
2549 		    blob_set(lp->ll_blob, il,
2550 			    blob_get(rettv->vval.v_blob, ir++));
2551 	    }
2552 	    else
2553 	    {
2554 		val = (int)tv_get_number_chk(rettv, &error);
2555 		if (!error)
2556 		{
2557 		    garray_T *gap = &lp->ll_blob->bv_ga;
2558 
2559 		    // Allow for appending a byte.  Setting a byte beyond
2560 		    // the end is an error otherwise.
2561 		    if (lp->ll_n1 < gap->ga_len
2562 			    || (lp->ll_n1 == gap->ga_len
2563 				&& ga_grow(&lp->ll_blob->bv_ga, 1) == OK))
2564 		    {
2565 			blob_set(lp->ll_blob, lp->ll_n1, val);
2566 			if (lp->ll_n1 == gap->ga_len)
2567 			    ++gap->ga_len;
2568 		    }
2569 		    // error for invalid range was already given in get_lval()
2570 		}
2571 	    }
2572 	}
2573 	else if (op != NULL && *op != '=')
2574 	{
2575 	    typval_T tv;
2576 
2577 	    if (is_const)
2578 	    {
2579 		emsg(_(e_cannot_mod));
2580 		*endp = cc;
2581 		return;
2582 	    }
2583 
2584 	    // handle +=, -=, *=, /=, %= and .=
2585 	    di = NULL;
2586 	    if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
2587 					     &tv, &di, TRUE, FALSE) == OK)
2588 	    {
2589 		if ((di == NULL
2590 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
2591 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
2592 			&& tv_op(&tv, rettv, op) == OK)
2593 		    set_var(lp->ll_name, &tv, FALSE);
2594 		clear_tv(&tv);
2595 	    }
2596 	}
2597 	else
2598 	    set_var_const(lp->ll_name, rettv, copy, is_const);
2599 	*endp = cc;
2600     }
2601     else if (var_check_lock(lp->ll_newkey == NULL
2602 		? lp->ll_tv->v_lock
2603 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
2604 	;
2605     else if (lp->ll_range)
2606     {
2607 	listitem_T *ll_li = lp->ll_li;
2608 	int	    ll_n1 = lp->ll_n1;
2609 
2610 	if (is_const)
2611 	{
2612 	    emsg(_("E996: Cannot lock a range"));
2613 	    return;
2614 	}
2615 
2616 	/*
2617 	 * Check whether any of the list items is locked
2618 	 */
2619 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
2620 	{
2621 	    if (var_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
2622 		return;
2623 	    ri = ri->li_next;
2624 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
2625 		break;
2626 	    ll_li = ll_li->li_next;
2627 	    ++ll_n1;
2628 	}
2629 
2630 	/*
2631 	 * Assign the List values to the list items.
2632 	 */
2633 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
2634 	{
2635 	    if (op != NULL && *op != '=')
2636 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
2637 	    else
2638 	    {
2639 		clear_tv(&lp->ll_li->li_tv);
2640 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
2641 	    }
2642 	    ri = ri->li_next;
2643 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
2644 		break;
2645 	    if (lp->ll_li->li_next == NULL)
2646 	    {
2647 		/* Need to add an empty item. */
2648 		if (list_append_number(lp->ll_list, 0) == FAIL)
2649 		{
2650 		    ri = NULL;
2651 		    break;
2652 		}
2653 	    }
2654 	    lp->ll_li = lp->ll_li->li_next;
2655 	    ++lp->ll_n1;
2656 	}
2657 	if (ri != NULL)
2658 	    emsg(_("E710: List value has more items than target"));
2659 	else if (lp->ll_empty2
2660 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
2661 		: lp->ll_n1 != lp->ll_n2)
2662 	    emsg(_("E711: List value has not enough items"));
2663     }
2664     else
2665     {
2666 	/*
2667 	 * Assign to a List or Dictionary item.
2668 	 */
2669 	if (is_const)
2670 	{
2671 	    emsg(_("E996: Cannot lock a list or dict"));
2672 	    return;
2673 	}
2674 	if (lp->ll_newkey != NULL)
2675 	{
2676 	    if (op != NULL && *op != '=')
2677 	    {
2678 		semsg(_(e_letwrong), op);
2679 		return;
2680 	    }
2681 
2682 	    /* Need to add an item to the Dictionary. */
2683 	    di = dictitem_alloc(lp->ll_newkey);
2684 	    if (di == NULL)
2685 		return;
2686 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
2687 	    {
2688 		vim_free(di);
2689 		return;
2690 	    }
2691 	    lp->ll_tv = &di->di_tv;
2692 	}
2693 	else if (op != NULL && *op != '=')
2694 	{
2695 	    tv_op(lp->ll_tv, rettv, op);
2696 	    return;
2697 	}
2698 	else
2699 	    clear_tv(lp->ll_tv);
2700 
2701 	/*
2702 	 * Assign the value to the variable or list item.
2703 	 */
2704 	if (copy)
2705 	    copy_tv(rettv, lp->ll_tv);
2706 	else
2707 	{
2708 	    *lp->ll_tv = *rettv;
2709 	    lp->ll_tv->v_lock = 0;
2710 	    init_tv(rettv);
2711 	}
2712     }
2713 }
2714 
2715 /*
2716  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
2717  * and "tv1 .= tv2"
2718  * Returns OK or FAIL.
2719  */
2720     static int
2721 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
2722 {
2723     varnumber_T	n;
2724     char_u	numbuf[NUMBUFLEN];
2725     char_u	*s;
2726 
2727     /* Can't do anything with a Funcref, Dict, v:true on the right. */
2728     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
2729 						&& tv2->v_type != VAR_SPECIAL)
2730     {
2731 	switch (tv1->v_type)
2732 	{
2733 	    case VAR_UNKNOWN:
2734 	    case VAR_DICT:
2735 	    case VAR_FUNC:
2736 	    case VAR_PARTIAL:
2737 	    case VAR_SPECIAL:
2738 	    case VAR_JOB:
2739 	    case VAR_CHANNEL:
2740 		break;
2741 
2742 	    case VAR_BLOB:
2743 		if (*op != '+' || tv2->v_type != VAR_BLOB)
2744 		    break;
2745 		// BLOB += BLOB
2746 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
2747 		{
2748 		    blob_T  *b1 = tv1->vval.v_blob;
2749 		    blob_T  *b2 = tv2->vval.v_blob;
2750 		    int	i, len = blob_len(b2);
2751 		    for (i = 0; i < len; i++)
2752 			ga_append(&b1->bv_ga, blob_get(b2, i));
2753 		}
2754 		return OK;
2755 
2756 	    case VAR_LIST:
2757 		if (*op != '+' || tv2->v_type != VAR_LIST)
2758 		    break;
2759 		// List += List
2760 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
2761 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
2762 		return OK;
2763 
2764 	    case VAR_NUMBER:
2765 	    case VAR_STRING:
2766 		if (tv2->v_type == VAR_LIST)
2767 		    break;
2768 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
2769 		{
2770 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
2771 		    n = tv_get_number(tv1);
2772 #ifdef FEAT_FLOAT
2773 		    if (tv2->v_type == VAR_FLOAT)
2774 		    {
2775 			float_T f = n;
2776 
2777 			if (*op == '%')
2778 			    break;
2779 			switch (*op)
2780 			{
2781 			    case '+': f += tv2->vval.v_float; break;
2782 			    case '-': f -= tv2->vval.v_float; break;
2783 			    case '*': f *= tv2->vval.v_float; break;
2784 			    case '/': f /= tv2->vval.v_float; break;
2785 			}
2786 			clear_tv(tv1);
2787 			tv1->v_type = VAR_FLOAT;
2788 			tv1->vval.v_float = f;
2789 		    }
2790 		    else
2791 #endif
2792 		    {
2793 			switch (*op)
2794 			{
2795 			    case '+': n += tv_get_number(tv2); break;
2796 			    case '-': n -= tv_get_number(tv2); break;
2797 			    case '*': n *= tv_get_number(tv2); break;
2798 			    case '/': n = num_divide(n, tv_get_number(tv2)); break;
2799 			    case '%': n = num_modulus(n, tv_get_number(tv2)); break;
2800 			}
2801 			clear_tv(tv1);
2802 			tv1->v_type = VAR_NUMBER;
2803 			tv1->vval.v_number = n;
2804 		    }
2805 		}
2806 		else
2807 		{
2808 		    if (tv2->v_type == VAR_FLOAT)
2809 			break;
2810 
2811 		    // str .= str
2812 		    s = tv_get_string(tv1);
2813 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
2814 		    clear_tv(tv1);
2815 		    tv1->v_type = VAR_STRING;
2816 		    tv1->vval.v_string = s;
2817 		}
2818 		return OK;
2819 
2820 	    case VAR_FLOAT:
2821 #ifdef FEAT_FLOAT
2822 		{
2823 		    float_T f;
2824 
2825 		    if (*op == '%' || *op == '.'
2826 				   || (tv2->v_type != VAR_FLOAT
2827 				    && tv2->v_type != VAR_NUMBER
2828 				    && tv2->v_type != VAR_STRING))
2829 			break;
2830 		    if (tv2->v_type == VAR_FLOAT)
2831 			f = tv2->vval.v_float;
2832 		    else
2833 			f = tv_get_number(tv2);
2834 		    switch (*op)
2835 		    {
2836 			case '+': tv1->vval.v_float += f; break;
2837 			case '-': tv1->vval.v_float -= f; break;
2838 			case '*': tv1->vval.v_float *= f; break;
2839 			case '/': tv1->vval.v_float /= f; break;
2840 		    }
2841 		}
2842 #endif
2843 		return OK;
2844 	}
2845     }
2846 
2847     semsg(_(e_letwrong), op);
2848     return FAIL;
2849 }
2850 
2851 /*
2852  * Evaluate the expression used in a ":for var in expr" command.
2853  * "arg" points to "var".
2854  * Set "*errp" to TRUE for an error, FALSE otherwise;
2855  * Return a pointer that holds the info.  Null when there is an error.
2856  */
2857     void *
2858 eval_for_line(
2859     char_u	*arg,
2860     int		*errp,
2861     char_u	**nextcmdp,
2862     int		skip)
2863 {
2864     forinfo_T	*fi;
2865     char_u	*expr;
2866     typval_T	tv;
2867     list_T	*l;
2868 
2869     *errp = TRUE;	/* default: there is an error */
2870 
2871     fi = ALLOC_CLEAR_ONE(forinfo_T);
2872     if (fi == NULL)
2873 	return NULL;
2874 
2875     expr = skip_var_list(arg, &fi->fi_varcount, &fi->fi_semicolon);
2876     if (expr == NULL)
2877 	return fi;
2878 
2879     expr = skipwhite(expr);
2880     if (expr[0] != 'i' || expr[1] != 'n' || !VIM_ISWHITE(expr[2]))
2881     {
2882 	emsg(_("E690: Missing \"in\" after :for"));
2883 	return fi;
2884     }
2885 
2886     if (skip)
2887 	++emsg_skip;
2888     if (eval0(skipwhite(expr + 2), &tv, nextcmdp, !skip) == OK)
2889     {
2890 	*errp = FALSE;
2891 	if (!skip)
2892 	{
2893 	    if (tv.v_type == VAR_LIST)
2894 	    {
2895 		l = tv.vval.v_list;
2896 		if (l == NULL)
2897 		{
2898 		    // a null list is like an empty list: do nothing
2899 		    clear_tv(&tv);
2900 		}
2901 		else
2902 		{
2903 		    // No need to increment the refcount, it's already set for
2904 		    // the list being used in "tv".
2905 		    fi->fi_list = l;
2906 		    list_add_watch(l, &fi->fi_lw);
2907 		    fi->fi_lw.lw_item = l->lv_first;
2908 		}
2909 	    }
2910 	    else if (tv.v_type == VAR_BLOB)
2911 	    {
2912 		fi->fi_bi = 0;
2913 		if (tv.vval.v_blob != NULL)
2914 		{
2915 		    typval_T btv;
2916 
2917 		    // Make a copy, so that the iteration still works when the
2918 		    // blob is changed.
2919 		    blob_copy(&tv, &btv);
2920 		    fi->fi_blob = btv.vval.v_blob;
2921 		}
2922 		clear_tv(&tv);
2923 	    }
2924 	    else
2925 	    {
2926 		emsg(_(e_listreq));
2927 		clear_tv(&tv);
2928 	    }
2929 	}
2930     }
2931     if (skip)
2932 	--emsg_skip;
2933 
2934     return fi;
2935 }
2936 
2937 /*
2938  * Use the first item in a ":for" list.  Advance to the next.
2939  * Assign the values to the variable (list).  "arg" points to the first one.
2940  * Return TRUE when a valid item was found, FALSE when at end of list or
2941  * something wrong.
2942  */
2943     int
2944 next_for_item(void *fi_void, char_u *arg)
2945 {
2946     forinfo_T	*fi = (forinfo_T *)fi_void;
2947     int		result;
2948     listitem_T	*item;
2949 
2950     if (fi->fi_blob != NULL)
2951     {
2952 	typval_T	tv;
2953 
2954 	if (fi->fi_bi >= blob_len(fi->fi_blob))
2955 	    return FALSE;
2956 	tv.v_type = VAR_NUMBER;
2957 	tv.v_lock = VAR_FIXED;
2958 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
2959 	++fi->fi_bi;
2960 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
2961 					   fi->fi_varcount, FALSE, NULL) == OK;
2962     }
2963 
2964     item = fi->fi_lw.lw_item;
2965     if (item == NULL)
2966 	result = FALSE;
2967     else
2968     {
2969 	fi->fi_lw.lw_item = item->li_next;
2970 	result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
2971 					  fi->fi_varcount, FALSE, NULL) == OK);
2972     }
2973     return result;
2974 }
2975 
2976 /*
2977  * Free the structure used to store info used by ":for".
2978  */
2979     void
2980 free_for_info(void *fi_void)
2981 {
2982     forinfo_T    *fi = (forinfo_T *)fi_void;
2983 
2984     if (fi != NULL && fi->fi_list != NULL)
2985     {
2986 	list_rem_watch(fi->fi_list, &fi->fi_lw);
2987 	list_unref(fi->fi_list);
2988     }
2989     if (fi != NULL && fi->fi_blob != NULL)
2990 	blob_unref(fi->fi_blob);
2991     vim_free(fi);
2992 }
2993 
2994 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
2995 
2996     void
2997 set_context_for_expression(
2998     expand_T	*xp,
2999     char_u	*arg,
3000     cmdidx_T	cmdidx)
3001 {
3002     int		got_eq = FALSE;
3003     int		c;
3004     char_u	*p;
3005 
3006     if (cmdidx == CMD_let)
3007     {
3008 	xp->xp_context = EXPAND_USER_VARS;
3009 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
3010 	{
3011 	    /* ":let var1 var2 ...": find last space. */
3012 	    for (p = arg + STRLEN(arg); p >= arg; )
3013 	    {
3014 		xp->xp_pattern = p;
3015 		MB_PTR_BACK(arg, p);
3016 		if (VIM_ISWHITE(*p))
3017 		    break;
3018 	    }
3019 	    return;
3020 	}
3021     }
3022     else
3023 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
3024 							  : EXPAND_EXPRESSION;
3025     while ((xp->xp_pattern = vim_strpbrk(arg,
3026 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
3027     {
3028 	c = *xp->xp_pattern;
3029 	if (c == '&')
3030 	{
3031 	    c = xp->xp_pattern[1];
3032 	    if (c == '&')
3033 	    {
3034 		++xp->xp_pattern;
3035 		xp->xp_context = cmdidx != CMD_let || got_eq
3036 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
3037 	    }
3038 	    else if (c != ' ')
3039 	    {
3040 		xp->xp_context = EXPAND_SETTINGS;
3041 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
3042 		    xp->xp_pattern += 2;
3043 
3044 	    }
3045 	}
3046 	else if (c == '$')
3047 	{
3048 	    /* environment variable */
3049 	    xp->xp_context = EXPAND_ENV_VARS;
3050 	}
3051 	else if (c == '=')
3052 	{
3053 	    got_eq = TRUE;
3054 	    xp->xp_context = EXPAND_EXPRESSION;
3055 	}
3056 	else if (c == '#'
3057 		&& xp->xp_context == EXPAND_EXPRESSION)
3058 	{
3059 	    /* Autoload function/variable contains '#'. */
3060 	    break;
3061 	}
3062 	else if ((c == '<' || c == '#')
3063 		&& xp->xp_context == EXPAND_FUNCTIONS
3064 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
3065 	{
3066 	    /* Function name can start with "<SNR>" and contain '#'. */
3067 	    break;
3068 	}
3069 	else if (cmdidx != CMD_let || got_eq)
3070 	{
3071 	    if (c == '"')	    /* string */
3072 	    {
3073 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
3074 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
3075 			++xp->xp_pattern;
3076 		xp->xp_context = EXPAND_NOTHING;
3077 	    }
3078 	    else if (c == '\'')	    /* literal string */
3079 	    {
3080 		/* Trick: '' is like stopping and starting a literal string. */
3081 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
3082 		    /* skip */ ;
3083 		xp->xp_context = EXPAND_NOTHING;
3084 	    }
3085 	    else if (c == '|')
3086 	    {
3087 		if (xp->xp_pattern[1] == '|')
3088 		{
3089 		    ++xp->xp_pattern;
3090 		    xp->xp_context = EXPAND_EXPRESSION;
3091 		}
3092 		else
3093 		    xp->xp_context = EXPAND_COMMANDS;
3094 	    }
3095 	    else
3096 		xp->xp_context = EXPAND_EXPRESSION;
3097 	}
3098 	else
3099 	    /* Doesn't look like something valid, expand as an expression
3100 	     * anyway. */
3101 	    xp->xp_context = EXPAND_EXPRESSION;
3102 	arg = xp->xp_pattern;
3103 	if (*arg != NUL)
3104 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
3105 		/* skip */ ;
3106     }
3107     xp->xp_pattern = arg;
3108 }
3109 
3110 #endif /* FEAT_CMDL_COMPL */
3111 
3112 /*
3113  * ":unlet[!] var1 ... " command.
3114  */
3115     void
3116 ex_unlet(exarg_T *eap)
3117 {
3118     ex_unletlock(eap, eap->arg, 0);
3119 }
3120 
3121 /*
3122  * ":lockvar" and ":unlockvar" commands
3123  */
3124     void
3125 ex_lockvar(exarg_T *eap)
3126 {
3127     char_u	*arg = eap->arg;
3128     int		deep = 2;
3129 
3130     if (eap->forceit)
3131 	deep = -1;
3132     else if (vim_isdigit(*arg))
3133     {
3134 	deep = getdigits(&arg);
3135 	arg = skipwhite(arg);
3136     }
3137 
3138     ex_unletlock(eap, arg, deep);
3139 }
3140 
3141 /*
3142  * ":unlet", ":lockvar" and ":unlockvar" are quite similar.
3143  */
3144     static void
3145 ex_unletlock(
3146     exarg_T	*eap,
3147     char_u	*argstart,
3148     int		deep)
3149 {
3150     char_u	*arg = argstart;
3151     char_u	*name_end;
3152     int		error = FALSE;
3153     lval_T	lv;
3154 
3155     do
3156     {
3157 	if (*arg == '$')
3158 	{
3159 	    char_u    *name = ++arg;
3160 
3161 	    if (get_env_len(&arg) == 0)
3162 	    {
3163 		semsg(_(e_invarg2), name - 1);
3164 		return;
3165 	    }
3166 	    vim_unsetenv(name);
3167 	    arg = skipwhite(arg);
3168 	    continue;
3169 	}
3170 
3171 	/* Parse the name and find the end. */
3172 	name_end = get_lval(arg, NULL, &lv, TRUE, eap->skip || error, 0,
3173 							     FNE_CHECK_START);
3174 	if (lv.ll_name == NULL)
3175 	    error = TRUE;	    /* error but continue parsing */
3176 	if (name_end == NULL || (!VIM_ISWHITE(*name_end)
3177 						   && !ends_excmd(*name_end)))
3178 	{
3179 	    if (name_end != NULL)
3180 	    {
3181 		emsg_severe = TRUE;
3182 		emsg(_(e_trailing));
3183 	    }
3184 	    if (!(eap->skip || error))
3185 		clear_lval(&lv);
3186 	    break;
3187 	}
3188 
3189 	if (!error && !eap->skip)
3190 	{
3191 	    if (eap->cmdidx == CMD_unlet)
3192 	    {
3193 		if (do_unlet_var(&lv, name_end, eap->forceit) == FAIL)
3194 		    error = TRUE;
3195 	    }
3196 	    else
3197 	    {
3198 		if (do_lock_var(&lv, name_end, deep,
3199 					  eap->cmdidx == CMD_lockvar) == FAIL)
3200 		    error = TRUE;
3201 	    }
3202 	}
3203 
3204 	if (!eap->skip)
3205 	    clear_lval(&lv);
3206 
3207 	arg = skipwhite(name_end);
3208     } while (!ends_excmd(*arg));
3209 
3210     eap->nextcmd = check_nextcmd(arg);
3211 }
3212 
3213     static int
3214 do_unlet_var(
3215     lval_T	*lp,
3216     char_u	*name_end,
3217     int		forceit)
3218 {
3219     int		ret = OK;
3220     int		cc;
3221 
3222     if (lp->ll_tv == NULL)
3223     {
3224 	cc = *name_end;
3225 	*name_end = NUL;
3226 
3227 	/* Normal name or expanded name. */
3228 	if (do_unlet(lp->ll_name, forceit) == FAIL)
3229 	    ret = FAIL;
3230 	*name_end = cc;
3231     }
3232     else if ((lp->ll_list != NULL
3233 		 && var_check_lock(lp->ll_list->lv_lock, lp->ll_name, FALSE))
3234 	    || (lp->ll_dict != NULL
3235 		 && var_check_lock(lp->ll_dict->dv_lock, lp->ll_name, FALSE)))
3236 	return FAIL;
3237     else if (lp->ll_range)
3238     {
3239 	listitem_T    *li;
3240 	listitem_T    *ll_li = lp->ll_li;
3241 	int	      ll_n1 = lp->ll_n1;
3242 
3243 	while (ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= ll_n1))
3244 	{
3245 	    li = ll_li->li_next;
3246 	    if (var_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
3247 		return FAIL;
3248 	    ll_li = li;
3249 	    ++ll_n1;
3250 	}
3251 
3252 	/* Delete a range of List items. */
3253 	while (lp->ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
3254 	{
3255 	    li = lp->ll_li->li_next;
3256 	    listitem_remove(lp->ll_list, lp->ll_li);
3257 	    lp->ll_li = li;
3258 	    ++lp->ll_n1;
3259 	}
3260     }
3261     else
3262     {
3263 	if (lp->ll_list != NULL)
3264 	    /* unlet a List item. */
3265 	    listitem_remove(lp->ll_list, lp->ll_li);
3266 	else
3267 	    /* unlet a Dictionary item. */
3268 	    dictitem_remove(lp->ll_dict, lp->ll_di);
3269     }
3270 
3271     return ret;
3272 }
3273 
3274 /*
3275  * "unlet" a variable.  Return OK if it existed, FAIL if not.
3276  * When "forceit" is TRUE don't complain if the variable doesn't exist.
3277  */
3278     int
3279 do_unlet(char_u *name, int forceit)
3280 {
3281     hashtab_T	*ht;
3282     hashitem_T	*hi;
3283     char_u	*varname;
3284     dict_T	*d;
3285     dictitem_T	*di;
3286 
3287     ht = find_var_ht(name, &varname);
3288     if (ht != NULL && *varname != NUL)
3289     {
3290 	d = get_current_funccal_dict(ht);
3291 	if (d == NULL)
3292 	{
3293 	    if (ht == &globvarht)
3294 		d = &globvardict;
3295 	    else if (ht == &compat_hashtab)
3296 		d = &vimvardict;
3297 	    else
3298 	    {
3299 		di = find_var_in_ht(ht, *name, (char_u *)"", FALSE);
3300 		d = di == NULL ? NULL : di->di_tv.vval.v_dict;
3301 	    }
3302 	    if (d == NULL)
3303 	    {
3304 		internal_error("do_unlet()");
3305 		return FAIL;
3306 	    }
3307 	}
3308 	hi = hash_find(ht, varname);
3309 	if (HASHITEM_EMPTY(hi))
3310 	    hi = find_hi_in_scoped_ht(name, &ht);
3311 	if (hi != NULL && !HASHITEM_EMPTY(hi))
3312 	{
3313 	    di = HI2DI(hi);
3314 	    if (var_check_fixed(di->di_flags, name, FALSE)
3315 		    || var_check_ro(di->di_flags, name, FALSE)
3316 		    || var_check_lock(d->dv_lock, name, FALSE))
3317 		return FAIL;
3318 
3319 	    delete_var(ht, hi);
3320 	    return OK;
3321 	}
3322     }
3323     if (forceit)
3324 	return OK;
3325     semsg(_("E108: No such variable: \"%s\""), name);
3326     return FAIL;
3327 }
3328 
3329 /*
3330  * Lock or unlock variable indicated by "lp".
3331  * "deep" is the levels to go (-1 for unlimited);
3332  * "lock" is TRUE for ":lockvar", FALSE for ":unlockvar".
3333  */
3334     static int
3335 do_lock_var(
3336     lval_T	*lp,
3337     char_u	*name_end,
3338     int		deep,
3339     int		lock)
3340 {
3341     int		ret = OK;
3342     int		cc;
3343     dictitem_T	*di;
3344 
3345     if (deep == 0)	/* nothing to do */
3346 	return OK;
3347 
3348     if (lp->ll_tv == NULL)
3349     {
3350 	cc = *name_end;
3351 	*name_end = NUL;
3352 
3353 	/* Normal name or expanded name. */
3354 	di = find_var(lp->ll_name, NULL, TRUE);
3355 	if (di == NULL)
3356 	    ret = FAIL;
3357 	else if ((di->di_flags & DI_FLAGS_FIX)
3358 			&& di->di_tv.v_type != VAR_DICT
3359 			&& di->di_tv.v_type != VAR_LIST)
3360 	    /* For historic reasons this error is not given for a list or dict.
3361 	     * E.g., the b: dict could be locked/unlocked. */
3362 	    semsg(_("E940: Cannot lock or unlock variable %s"), lp->ll_name);
3363 	else
3364 	{
3365 	    if (lock)
3366 		di->di_flags |= DI_FLAGS_LOCK;
3367 	    else
3368 		di->di_flags &= ~DI_FLAGS_LOCK;
3369 	    item_lock(&di->di_tv, deep, lock);
3370 	}
3371 	*name_end = cc;
3372     }
3373     else if (lp->ll_range)
3374     {
3375 	listitem_T    *li = lp->ll_li;
3376 
3377 	/* (un)lock a range of List items. */
3378 	while (li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
3379 	{
3380 	    item_lock(&li->li_tv, deep, lock);
3381 	    li = li->li_next;
3382 	    ++lp->ll_n1;
3383 	}
3384     }
3385     else if (lp->ll_list != NULL)
3386 	/* (un)lock a List item. */
3387 	item_lock(&lp->ll_li->li_tv, deep, lock);
3388     else
3389 	/* (un)lock a Dictionary item. */
3390 	item_lock(&lp->ll_di->di_tv, deep, lock);
3391 
3392     return ret;
3393 }
3394 
3395 /*
3396  * Lock or unlock an item.  "deep" is nr of levels to go.
3397  */
3398     static void
3399 item_lock(typval_T *tv, int deep, int lock)
3400 {
3401     static int	recurse = 0;
3402     list_T	*l;
3403     listitem_T	*li;
3404     dict_T	*d;
3405     blob_T	*b;
3406     hashitem_T	*hi;
3407     int		todo;
3408 
3409     if (recurse >= DICT_MAXNEST)
3410     {
3411 	emsg(_("E743: variable nested too deep for (un)lock"));
3412 	return;
3413     }
3414     if (deep == 0)
3415 	return;
3416     ++recurse;
3417 
3418     /* lock/unlock the item itself */
3419     if (lock)
3420 	tv->v_lock |= VAR_LOCKED;
3421     else
3422 	tv->v_lock &= ~VAR_LOCKED;
3423 
3424     switch (tv->v_type)
3425     {
3426 	case VAR_UNKNOWN:
3427 	case VAR_NUMBER:
3428 	case VAR_STRING:
3429 	case VAR_FUNC:
3430 	case VAR_PARTIAL:
3431 	case VAR_FLOAT:
3432 	case VAR_SPECIAL:
3433 	case VAR_JOB:
3434 	case VAR_CHANNEL:
3435 	    break;
3436 
3437 	case VAR_BLOB:
3438 	    if ((b = tv->vval.v_blob) != NULL)
3439 	    {
3440 		if (lock)
3441 		    b->bv_lock |= VAR_LOCKED;
3442 		else
3443 		    b->bv_lock &= ~VAR_LOCKED;
3444 	    }
3445 	    break;
3446 	case VAR_LIST:
3447 	    if ((l = tv->vval.v_list) != NULL)
3448 	    {
3449 		if (lock)
3450 		    l->lv_lock |= VAR_LOCKED;
3451 		else
3452 		    l->lv_lock &= ~VAR_LOCKED;
3453 		if (deep < 0 || deep > 1)
3454 		    /* recursive: lock/unlock the items the List contains */
3455 		    for (li = l->lv_first; li != NULL; li = li->li_next)
3456 			item_lock(&li->li_tv, deep - 1, lock);
3457 	    }
3458 	    break;
3459 	case VAR_DICT:
3460 	    if ((d = tv->vval.v_dict) != NULL)
3461 	    {
3462 		if (lock)
3463 		    d->dv_lock |= VAR_LOCKED;
3464 		else
3465 		    d->dv_lock &= ~VAR_LOCKED;
3466 		if (deep < 0 || deep > 1)
3467 		{
3468 		    /* recursive: lock/unlock the items the List contains */
3469 		    todo = (int)d->dv_hashtab.ht_used;
3470 		    for (hi = d->dv_hashtab.ht_array; todo > 0; ++hi)
3471 		    {
3472 			if (!HASHITEM_EMPTY(hi))
3473 			{
3474 			    --todo;
3475 			    item_lock(&HI2DI(hi)->di_tv, deep - 1, lock);
3476 			}
3477 		    }
3478 		}
3479 	    }
3480     }
3481     --recurse;
3482 }
3483 
3484 #if (defined(FEAT_MENU) && defined(FEAT_MULTI_LANG)) || defined(PROTO)
3485 /*
3486  * Delete all "menutrans_" variables.
3487  */
3488     void
3489 del_menutrans_vars(void)
3490 {
3491     hashitem_T	*hi;
3492     int		todo;
3493 
3494     hash_lock(&globvarht);
3495     todo = (int)globvarht.ht_used;
3496     for (hi = globvarht.ht_array; todo > 0 && !got_int; ++hi)
3497     {
3498 	if (!HASHITEM_EMPTY(hi))
3499 	{
3500 	    --todo;
3501 	    if (STRNCMP(HI2DI(hi)->di_key, "menutrans_", 10) == 0)
3502 		delete_var(&globvarht, hi);
3503 	}
3504     }
3505     hash_unlock(&globvarht);
3506 }
3507 #endif
3508 
3509 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
3510 
3511 /*
3512  * Local string buffer for the next two functions to store a variable name
3513  * with its prefix. Allocated in cat_prefix_varname(), freed later in
3514  * get_user_var_name().
3515  */
3516 
3517 static char_u	*varnamebuf = NULL;
3518 static int	varnamebuflen = 0;
3519 
3520 /*
3521  * Function to concatenate a prefix and a variable name.
3522  */
3523     static char_u *
3524 cat_prefix_varname(int prefix, char_u *name)
3525 {
3526     int		len;
3527 
3528     len = (int)STRLEN(name) + 3;
3529     if (len > varnamebuflen)
3530     {
3531 	vim_free(varnamebuf);
3532 	len += 10;			/* some additional space */
3533 	varnamebuf = alloc(len);
3534 	if (varnamebuf == NULL)
3535 	{
3536 	    varnamebuflen = 0;
3537 	    return NULL;
3538 	}
3539 	varnamebuflen = len;
3540     }
3541     *varnamebuf = prefix;
3542     varnamebuf[1] = ':';
3543     STRCPY(varnamebuf + 2, name);
3544     return varnamebuf;
3545 }
3546 
3547 /*
3548  * Function given to ExpandGeneric() to obtain the list of user defined
3549  * (global/buffer/window/built-in) variable names.
3550  */
3551     char_u *
3552 get_user_var_name(expand_T *xp, int idx)
3553 {
3554     static long_u	gdone;
3555     static long_u	bdone;
3556     static long_u	wdone;
3557     static long_u	tdone;
3558     static int		vidx;
3559     static hashitem_T	*hi;
3560     hashtab_T		*ht;
3561 
3562     if (idx == 0)
3563     {
3564 	gdone = bdone = wdone = vidx = 0;
3565 	tdone = 0;
3566     }
3567 
3568     /* Global variables */
3569     if (gdone < globvarht.ht_used)
3570     {
3571 	if (gdone++ == 0)
3572 	    hi = globvarht.ht_array;
3573 	else
3574 	    ++hi;
3575 	while (HASHITEM_EMPTY(hi))
3576 	    ++hi;
3577 	if (STRNCMP("g:", xp->xp_pattern, 2) == 0)
3578 	    return cat_prefix_varname('g', hi->hi_key);
3579 	return hi->hi_key;
3580     }
3581 
3582     /* b: variables */
3583     ht = &curbuf->b_vars->dv_hashtab;
3584     if (bdone < ht->ht_used)
3585     {
3586 	if (bdone++ == 0)
3587 	    hi = ht->ht_array;
3588 	else
3589 	    ++hi;
3590 	while (HASHITEM_EMPTY(hi))
3591 	    ++hi;
3592 	return cat_prefix_varname('b', hi->hi_key);
3593     }
3594 
3595     /* w: variables */
3596     ht = &curwin->w_vars->dv_hashtab;
3597     if (wdone < ht->ht_used)
3598     {
3599 	if (wdone++ == 0)
3600 	    hi = ht->ht_array;
3601 	else
3602 	    ++hi;
3603 	while (HASHITEM_EMPTY(hi))
3604 	    ++hi;
3605 	return cat_prefix_varname('w', hi->hi_key);
3606     }
3607 
3608     /* t: variables */
3609     ht = &curtab->tp_vars->dv_hashtab;
3610     if (tdone < ht->ht_used)
3611     {
3612 	if (tdone++ == 0)
3613 	    hi = ht->ht_array;
3614 	else
3615 	    ++hi;
3616 	while (HASHITEM_EMPTY(hi))
3617 	    ++hi;
3618 	return cat_prefix_varname('t', hi->hi_key);
3619     }
3620 
3621     /* v: variables */
3622     if (vidx < VV_LEN)
3623 	return cat_prefix_varname('v', (char_u *)vimvars[vidx++].vv_name);
3624 
3625     VIM_CLEAR(varnamebuf);
3626     varnamebuflen = 0;
3627     return NULL;
3628 }
3629 
3630 #endif /* FEAT_CMDL_COMPL */
3631 
3632 /*
3633  * Return TRUE if "pat" matches "text".
3634  * Does not use 'cpo' and always uses 'magic'.
3635  */
3636     int
3637 pattern_match(char_u *pat, char_u *text, int ic)
3638 {
3639     int		matches = FALSE;
3640     char_u	*save_cpo;
3641     regmatch_T	regmatch;
3642 
3643     /* avoid 'l' flag in 'cpoptions' */
3644     save_cpo = p_cpo;
3645     p_cpo = (char_u *)"";
3646     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
3647     if (regmatch.regprog != NULL)
3648     {
3649 	regmatch.rm_ic = ic;
3650 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
3651 	vim_regfree(regmatch.regprog);
3652     }
3653     p_cpo = save_cpo;
3654     return matches;
3655 }
3656 
3657 /*
3658  * The "evaluate" argument: When FALSE, the argument is only parsed but not
3659  * executed.  The function may return OK, but the rettv will be of type
3660  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
3661  */
3662 
3663 /*
3664  * Handle zero level expression.
3665  * This calls eval1() and handles error message and nextcmd.
3666  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
3667  * Note: "rettv.v_lock" is not set.
3668  * Return OK or FAIL.
3669  */
3670     int
3671 eval0(
3672     char_u	*arg,
3673     typval_T	*rettv,
3674     char_u	**nextcmd,
3675     int		evaluate)
3676 {
3677     int		ret;
3678     char_u	*p;
3679     int		did_emsg_before = did_emsg;
3680     int		called_emsg_before = called_emsg;
3681 
3682     p = skipwhite(arg);
3683     ret = eval1(&p, rettv, evaluate);
3684     if (ret == FAIL || !ends_excmd(*p))
3685     {
3686 	if (ret != FAIL)
3687 	    clear_tv(rettv);
3688 	/*
3689 	 * Report the invalid expression unless the expression evaluation has
3690 	 * been cancelled due to an aborting error, an interrupt, or an
3691 	 * exception, or we already gave a more specific error.
3692 	 * Also check called_emsg for when using assert_fails().
3693 	 */
3694 	if (!aborting() && did_emsg == did_emsg_before
3695 					  && called_emsg == called_emsg_before)
3696 	    semsg(_(e_invexpr2), arg);
3697 	ret = FAIL;
3698     }
3699     if (nextcmd != NULL)
3700 	*nextcmd = check_nextcmd(p);
3701 
3702     return ret;
3703 }
3704 
3705 /*
3706  * Handle top level expression:
3707  *	expr2 ? expr1 : expr1
3708  *
3709  * "arg" must point to the first non-white of the expression.
3710  * "arg" is advanced to the next non-white after the recognized expression.
3711  *
3712  * Note: "rettv.v_lock" is not set.
3713  *
3714  * Return OK or FAIL.
3715  */
3716     int
3717 eval1(char_u **arg, typval_T *rettv, int evaluate)
3718 {
3719     int		result;
3720     typval_T	var2;
3721 
3722     /*
3723      * Get the first variable.
3724      */
3725     if (eval2(arg, rettv, evaluate) == FAIL)
3726 	return FAIL;
3727 
3728     if ((*arg)[0] == '?')
3729     {
3730 	result = FALSE;
3731 	if (evaluate)
3732 	{
3733 	    int		error = FALSE;
3734 
3735 	    if (tv_get_number_chk(rettv, &error) != 0)
3736 		result = TRUE;
3737 	    clear_tv(rettv);
3738 	    if (error)
3739 		return FAIL;
3740 	}
3741 
3742 	/*
3743 	 * Get the second variable.
3744 	 */
3745 	*arg = skipwhite(*arg + 1);
3746 	if (eval1(arg, rettv, evaluate && result) == FAIL) /* recursive! */
3747 	    return FAIL;
3748 
3749 	/*
3750 	 * Check for the ":".
3751 	 */
3752 	if ((*arg)[0] != ':')
3753 	{
3754 	    emsg(_("E109: Missing ':' after '?'"));
3755 	    if (evaluate && result)
3756 		clear_tv(rettv);
3757 	    return FAIL;
3758 	}
3759 
3760 	/*
3761 	 * Get the third variable.
3762 	 */
3763 	*arg = skipwhite(*arg + 1);
3764 	if (eval1(arg, &var2, evaluate && !result) == FAIL) /* recursive! */
3765 	{
3766 	    if (evaluate && result)
3767 		clear_tv(rettv);
3768 	    return FAIL;
3769 	}
3770 	if (evaluate && !result)
3771 	    *rettv = var2;
3772     }
3773 
3774     return OK;
3775 }
3776 
3777 /*
3778  * Handle first level expression:
3779  *	expr2 || expr2 || expr2	    logical OR
3780  *
3781  * "arg" must point to the first non-white of the expression.
3782  * "arg" is advanced to the next non-white after the recognized expression.
3783  *
3784  * Return OK or FAIL.
3785  */
3786     static int
3787 eval2(char_u **arg, typval_T *rettv, int evaluate)
3788 {
3789     typval_T	var2;
3790     long	result;
3791     int		first;
3792     int		error = FALSE;
3793 
3794     /*
3795      * Get the first variable.
3796      */
3797     if (eval3(arg, rettv, evaluate) == FAIL)
3798 	return FAIL;
3799 
3800     /*
3801      * Repeat until there is no following "||".
3802      */
3803     first = TRUE;
3804     result = FALSE;
3805     while ((*arg)[0] == '|' && (*arg)[1] == '|')
3806     {
3807 	if (evaluate && first)
3808 	{
3809 	    if (tv_get_number_chk(rettv, &error) != 0)
3810 		result = TRUE;
3811 	    clear_tv(rettv);
3812 	    if (error)
3813 		return FAIL;
3814 	    first = FALSE;
3815 	}
3816 
3817 	/*
3818 	 * Get the second variable.
3819 	 */
3820 	*arg = skipwhite(*arg + 2);
3821 	if (eval3(arg, &var2, evaluate && !result) == FAIL)
3822 	    return FAIL;
3823 
3824 	/*
3825 	 * Compute the result.
3826 	 */
3827 	if (evaluate && !result)
3828 	{
3829 	    if (tv_get_number_chk(&var2, &error) != 0)
3830 		result = TRUE;
3831 	    clear_tv(&var2);
3832 	    if (error)
3833 		return FAIL;
3834 	}
3835 	if (evaluate)
3836 	{
3837 	    rettv->v_type = VAR_NUMBER;
3838 	    rettv->vval.v_number = result;
3839 	}
3840     }
3841 
3842     return OK;
3843 }
3844 
3845 /*
3846  * Handle second level expression:
3847  *	expr3 && expr3 && expr3	    logical AND
3848  *
3849  * "arg" must point to the first non-white of the expression.
3850  * "arg" is advanced to the next non-white after the recognized expression.
3851  *
3852  * Return OK or FAIL.
3853  */
3854     static int
3855 eval3(char_u **arg, typval_T *rettv, int evaluate)
3856 {
3857     typval_T	var2;
3858     long	result;
3859     int		first;
3860     int		error = FALSE;
3861 
3862     /*
3863      * Get the first variable.
3864      */
3865     if (eval4(arg, rettv, evaluate) == FAIL)
3866 	return FAIL;
3867 
3868     /*
3869      * Repeat until there is no following "&&".
3870      */
3871     first = TRUE;
3872     result = TRUE;
3873     while ((*arg)[0] == '&' && (*arg)[1] == '&')
3874     {
3875 	if (evaluate && first)
3876 	{
3877 	    if (tv_get_number_chk(rettv, &error) == 0)
3878 		result = FALSE;
3879 	    clear_tv(rettv);
3880 	    if (error)
3881 		return FAIL;
3882 	    first = FALSE;
3883 	}
3884 
3885 	/*
3886 	 * Get the second variable.
3887 	 */
3888 	*arg = skipwhite(*arg + 2);
3889 	if (eval4(arg, &var2, evaluate && result) == FAIL)
3890 	    return FAIL;
3891 
3892 	/*
3893 	 * Compute the result.
3894 	 */
3895 	if (evaluate && result)
3896 	{
3897 	    if (tv_get_number_chk(&var2, &error) == 0)
3898 		result = FALSE;
3899 	    clear_tv(&var2);
3900 	    if (error)
3901 		return FAIL;
3902 	}
3903 	if (evaluate)
3904 	{
3905 	    rettv->v_type = VAR_NUMBER;
3906 	    rettv->vval.v_number = result;
3907 	}
3908     }
3909 
3910     return OK;
3911 }
3912 
3913 /*
3914  * Handle third level expression:
3915  *	var1 == var2
3916  *	var1 =~ var2
3917  *	var1 != var2
3918  *	var1 !~ var2
3919  *	var1 > var2
3920  *	var1 >= var2
3921  *	var1 < var2
3922  *	var1 <= var2
3923  *	var1 is var2
3924  *	var1 isnot var2
3925  *
3926  * "arg" must point to the first non-white of the expression.
3927  * "arg" is advanced to the next non-white after the recognized expression.
3928  *
3929  * Return OK or FAIL.
3930  */
3931     static int
3932 eval4(char_u **arg, typval_T *rettv, int evaluate)
3933 {
3934     typval_T	var2;
3935     char_u	*p;
3936     int		i;
3937     exptype_T	type = TYPE_UNKNOWN;
3938     int		type_is = FALSE;    /* TRUE for "is" and "isnot" */
3939     int		len = 2;
3940     int		ic;
3941 
3942     /*
3943      * Get the first variable.
3944      */
3945     if (eval5(arg, rettv, evaluate) == FAIL)
3946 	return FAIL;
3947 
3948     p = *arg;
3949     switch (p[0])
3950     {
3951 	case '=':   if (p[1] == '=')
3952 			type = TYPE_EQUAL;
3953 		    else if (p[1] == '~')
3954 			type = TYPE_MATCH;
3955 		    break;
3956 	case '!':   if (p[1] == '=')
3957 			type = TYPE_NEQUAL;
3958 		    else if (p[1] == '~')
3959 			type = TYPE_NOMATCH;
3960 		    break;
3961 	case '>':   if (p[1] != '=')
3962 		    {
3963 			type = TYPE_GREATER;
3964 			len = 1;
3965 		    }
3966 		    else
3967 			type = TYPE_GEQUAL;
3968 		    break;
3969 	case '<':   if (p[1] != '=')
3970 		    {
3971 			type = TYPE_SMALLER;
3972 			len = 1;
3973 		    }
3974 		    else
3975 			type = TYPE_SEQUAL;
3976 		    break;
3977 	case 'i':   if (p[1] == 's')
3978 		    {
3979 			if (p[2] == 'n' && p[3] == 'o' && p[4] == 't')
3980 			    len = 5;
3981 			i = p[len];
3982 			if (!isalnum(i) && i != '_')
3983 			{
3984 			    type = len == 2 ? TYPE_EQUAL : TYPE_NEQUAL;
3985 			    type_is = TRUE;
3986 			}
3987 		    }
3988 		    break;
3989     }
3990 
3991     /*
3992      * If there is a comparative operator, use it.
3993      */
3994     if (type != TYPE_UNKNOWN)
3995     {
3996 	/* extra question mark appended: ignore case */
3997 	if (p[len] == '?')
3998 	{
3999 	    ic = TRUE;
4000 	    ++len;
4001 	}
4002 	/* extra '#' appended: match case */
4003 	else if (p[len] == '#')
4004 	{
4005 	    ic = FALSE;
4006 	    ++len;
4007 	}
4008 	/* nothing appended: use 'ignorecase' */
4009 	else
4010 	    ic = p_ic;
4011 
4012 	/*
4013 	 * Get the second variable.
4014 	 */
4015 	*arg = skipwhite(p + len);
4016 	if (eval5(arg, &var2, evaluate) == FAIL)
4017 	{
4018 	    clear_tv(rettv);
4019 	    return FAIL;
4020 	}
4021 	if (evaluate)
4022 	{
4023 	    int ret = typval_compare(rettv, &var2, type, type_is, ic);
4024 
4025 	    clear_tv(&var2);
4026 	    return ret;
4027 	}
4028     }
4029 
4030     return OK;
4031 }
4032 
4033 /*
4034  * Handle fourth level expression:
4035  *	+	number addition
4036  *	-	number subtraction
4037  *	.	string concatenation (if script version is 1)
4038  *	..	string concatenation
4039  *
4040  * "arg" must point to the first non-white of the expression.
4041  * "arg" is advanced to the next non-white after the recognized expression.
4042  *
4043  * Return OK or FAIL.
4044  */
4045     static int
4046 eval5(char_u **arg, typval_T *rettv, int evaluate)
4047 {
4048     typval_T	var2;
4049     typval_T	var3;
4050     int		op;
4051     varnumber_T	n1, n2;
4052 #ifdef FEAT_FLOAT
4053     float_T	f1 = 0, f2 = 0;
4054 #endif
4055     char_u	*s1, *s2;
4056     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
4057     char_u	*p;
4058     int		concat;
4059 
4060     /*
4061      * Get the first variable.
4062      */
4063     if (eval6(arg, rettv, evaluate, FALSE) == FAIL)
4064 	return FAIL;
4065 
4066     /*
4067      * Repeat computing, until no '+', '-' or '.' is following.
4068      */
4069     for (;;)
4070     {
4071 	// "." is only string concatenation when scriptversion is 1
4072 	op = **arg;
4073 	concat = op == '.'
4074 			&& (*(*arg + 1) == '.' || current_sctx.sc_version < 2);
4075 	if (op != '+' && op != '-' && !concat)
4076 	    break;
4077 
4078 	if ((op != '+' || (rettv->v_type != VAR_LIST
4079 						 && rettv->v_type != VAR_BLOB))
4080 #ifdef FEAT_FLOAT
4081 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
4082 #endif
4083 		)
4084 	{
4085 	    /* For "list + ...", an illegal use of the first operand as
4086 	     * a number cannot be determined before evaluating the 2nd
4087 	     * operand: if this is also a list, all is ok.
4088 	     * For "something . ...", "something - ..." or "non-list + ...",
4089 	     * we know that the first operand needs to be a string or number
4090 	     * without evaluating the 2nd operand.  So check before to avoid
4091 	     * side effects after an error. */
4092 	    if (evaluate && tv_get_string_chk(rettv) == NULL)
4093 	    {
4094 		clear_tv(rettv);
4095 		return FAIL;
4096 	    }
4097 	}
4098 
4099 	/*
4100 	 * Get the second variable.
4101 	 */
4102 	if (op == '.' && *(*arg + 1) == '.')  // .. string concatenation
4103 	    ++*arg;
4104 	*arg = skipwhite(*arg + 1);
4105 	if (eval6(arg, &var2, evaluate, op == '.') == FAIL)
4106 	{
4107 	    clear_tv(rettv);
4108 	    return FAIL;
4109 	}
4110 
4111 	if (evaluate)
4112 	{
4113 	    /*
4114 	     * Compute the result.
4115 	     */
4116 	    if (op == '.')
4117 	    {
4118 		s1 = tv_get_string_buf(rettv, buf1);	/* already checked */
4119 		s2 = tv_get_string_buf_chk(&var2, buf2);
4120 		if (s2 == NULL)		/* type error ? */
4121 		{
4122 		    clear_tv(rettv);
4123 		    clear_tv(&var2);
4124 		    return FAIL;
4125 		}
4126 		p = concat_str(s1, s2);
4127 		clear_tv(rettv);
4128 		rettv->v_type = VAR_STRING;
4129 		rettv->vval.v_string = p;
4130 	    }
4131 	    else if (op == '+' && rettv->v_type == VAR_BLOB
4132 						   && var2.v_type == VAR_BLOB)
4133 	    {
4134 		blob_T  *b1 = rettv->vval.v_blob;
4135 		blob_T  *b2 = var2.vval.v_blob;
4136 		blob_T	*b = blob_alloc();
4137 		int	i;
4138 
4139 		if (b != NULL)
4140 		{
4141 		    for (i = 0; i < blob_len(b1); i++)
4142 			ga_append(&b->bv_ga, blob_get(b1, i));
4143 		    for (i = 0; i < blob_len(b2); i++)
4144 			ga_append(&b->bv_ga, blob_get(b2, i));
4145 
4146 		    clear_tv(rettv);
4147 		    rettv_blob_set(rettv, b);
4148 		}
4149 	    }
4150 	    else if (op == '+' && rettv->v_type == VAR_LIST
4151 						   && var2.v_type == VAR_LIST)
4152 	    {
4153 		/* concatenate Lists */
4154 		if (list_concat(rettv->vval.v_list, var2.vval.v_list,
4155 							       &var3) == FAIL)
4156 		{
4157 		    clear_tv(rettv);
4158 		    clear_tv(&var2);
4159 		    return FAIL;
4160 		}
4161 		clear_tv(rettv);
4162 		*rettv = var3;
4163 	    }
4164 	    else
4165 	    {
4166 		int	    error = FALSE;
4167 
4168 #ifdef FEAT_FLOAT
4169 		if (rettv->v_type == VAR_FLOAT)
4170 		{
4171 		    f1 = rettv->vval.v_float;
4172 		    n1 = 0;
4173 		}
4174 		else
4175 #endif
4176 		{
4177 		    n1 = tv_get_number_chk(rettv, &error);
4178 		    if (error)
4179 		    {
4180 			/* This can only happen for "list + non-list".  For
4181 			 * "non-list + ..." or "something - ...", we returned
4182 			 * before evaluating the 2nd operand. */
4183 			clear_tv(rettv);
4184 			return FAIL;
4185 		    }
4186 #ifdef FEAT_FLOAT
4187 		    if (var2.v_type == VAR_FLOAT)
4188 			f1 = n1;
4189 #endif
4190 		}
4191 #ifdef FEAT_FLOAT
4192 		if (var2.v_type == VAR_FLOAT)
4193 		{
4194 		    f2 = var2.vval.v_float;
4195 		    n2 = 0;
4196 		}
4197 		else
4198 #endif
4199 		{
4200 		    n2 = tv_get_number_chk(&var2, &error);
4201 		    if (error)
4202 		    {
4203 			clear_tv(rettv);
4204 			clear_tv(&var2);
4205 			return FAIL;
4206 		    }
4207 #ifdef FEAT_FLOAT
4208 		    if (rettv->v_type == VAR_FLOAT)
4209 			f2 = n2;
4210 #endif
4211 		}
4212 		clear_tv(rettv);
4213 
4214 #ifdef FEAT_FLOAT
4215 		/* If there is a float on either side the result is a float. */
4216 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
4217 		{
4218 		    if (op == '+')
4219 			f1 = f1 + f2;
4220 		    else
4221 			f1 = f1 - f2;
4222 		    rettv->v_type = VAR_FLOAT;
4223 		    rettv->vval.v_float = f1;
4224 		}
4225 		else
4226 #endif
4227 		{
4228 		    if (op == '+')
4229 			n1 = n1 + n2;
4230 		    else
4231 			n1 = n1 - n2;
4232 		    rettv->v_type = VAR_NUMBER;
4233 		    rettv->vval.v_number = n1;
4234 		}
4235 	    }
4236 	    clear_tv(&var2);
4237 	}
4238     }
4239     return OK;
4240 }
4241 
4242 /*
4243  * Handle fifth level expression:
4244  *	*	number multiplication
4245  *	/	number division
4246  *	%	number modulo
4247  *
4248  * "arg" must point to the first non-white of the expression.
4249  * "arg" is advanced to the next non-white after the recognized expression.
4250  *
4251  * Return OK or FAIL.
4252  */
4253     static int
4254 eval6(
4255     char_u	**arg,
4256     typval_T	*rettv,
4257     int		evaluate,
4258     int		want_string)  /* after "." operator */
4259 {
4260     typval_T	var2;
4261     int		op;
4262     varnumber_T	n1, n2;
4263 #ifdef FEAT_FLOAT
4264     int		use_float = FALSE;
4265     float_T	f1 = 0, f2 = 0;
4266 #endif
4267     int		error = FALSE;
4268 
4269     /*
4270      * Get the first variable.
4271      */
4272     if (eval7(arg, rettv, evaluate, want_string) == FAIL)
4273 	return FAIL;
4274 
4275     /*
4276      * Repeat computing, until no '*', '/' or '%' is following.
4277      */
4278     for (;;)
4279     {
4280 	op = **arg;
4281 	if (op != '*' && op != '/' && op != '%')
4282 	    break;
4283 
4284 	if (evaluate)
4285 	{
4286 #ifdef FEAT_FLOAT
4287 	    if (rettv->v_type == VAR_FLOAT)
4288 	    {
4289 		f1 = rettv->vval.v_float;
4290 		use_float = TRUE;
4291 		n1 = 0;
4292 	    }
4293 	    else
4294 #endif
4295 		n1 = tv_get_number_chk(rettv, &error);
4296 	    clear_tv(rettv);
4297 	    if (error)
4298 		return FAIL;
4299 	}
4300 	else
4301 	    n1 = 0;
4302 
4303 	/*
4304 	 * Get the second variable.
4305 	 */
4306 	*arg = skipwhite(*arg + 1);
4307 	if (eval7(arg, &var2, evaluate, FALSE) == FAIL)
4308 	    return FAIL;
4309 
4310 	if (evaluate)
4311 	{
4312 #ifdef FEAT_FLOAT
4313 	    if (var2.v_type == VAR_FLOAT)
4314 	    {
4315 		if (!use_float)
4316 		{
4317 		    f1 = n1;
4318 		    use_float = TRUE;
4319 		}
4320 		f2 = var2.vval.v_float;
4321 		n2 = 0;
4322 	    }
4323 	    else
4324 #endif
4325 	    {
4326 		n2 = tv_get_number_chk(&var2, &error);
4327 		clear_tv(&var2);
4328 		if (error)
4329 		    return FAIL;
4330 #ifdef FEAT_FLOAT
4331 		if (use_float)
4332 		    f2 = n2;
4333 #endif
4334 	    }
4335 
4336 	    /*
4337 	     * Compute the result.
4338 	     * When either side is a float the result is a float.
4339 	     */
4340 #ifdef FEAT_FLOAT
4341 	    if (use_float)
4342 	    {
4343 		if (op == '*')
4344 		    f1 = f1 * f2;
4345 		else if (op == '/')
4346 		{
4347 # ifdef VMS
4348 		    /* VMS crashes on divide by zero, work around it */
4349 		    if (f2 == 0.0)
4350 		    {
4351 			if (f1 == 0)
4352 			    f1 = -1 * __F_FLT_MAX - 1L;   /* similar to NaN */
4353 			else if (f1 < 0)
4354 			    f1 = -1 * __F_FLT_MAX;
4355 			else
4356 			    f1 = __F_FLT_MAX;
4357 		    }
4358 		    else
4359 			f1 = f1 / f2;
4360 # else
4361 		    /* We rely on the floating point library to handle divide
4362 		     * by zero to result in "inf" and not a crash. */
4363 		    f1 = f1 / f2;
4364 # endif
4365 		}
4366 		else
4367 		{
4368 		    emsg(_("E804: Cannot use '%' with Float"));
4369 		    return FAIL;
4370 		}
4371 		rettv->v_type = VAR_FLOAT;
4372 		rettv->vval.v_float = f1;
4373 	    }
4374 	    else
4375 #endif
4376 	    {
4377 		if (op == '*')
4378 		    n1 = n1 * n2;
4379 		else if (op == '/')
4380 		    n1 = num_divide(n1, n2);
4381 		else
4382 		    n1 = num_modulus(n1, n2);
4383 
4384 		rettv->v_type = VAR_NUMBER;
4385 		rettv->vval.v_number = n1;
4386 	    }
4387 	}
4388     }
4389 
4390     return OK;
4391 }
4392 
4393 /*
4394  * Handle sixth level expression:
4395  *  number		number constant
4396  *  0zFFFFFFFF		Blob constant
4397  *  "string"		string constant
4398  *  'string'		literal string constant
4399  *  &option-name	option value
4400  *  @r			register contents
4401  *  identifier		variable value
4402  *  function()		function call
4403  *  $VAR		environment variable
4404  *  (expression)	nested expression
4405  *  [expr, expr]	List
4406  *  {key: val, key: val}   Dictionary
4407  *  #{key: val, key: val}  Dictionary with literal keys
4408  *
4409  *  Also handle:
4410  *  ! in front		logical NOT
4411  *  - in front		unary minus
4412  *  + in front		unary plus (ignored)
4413  *  trailing []		subscript in String or List
4414  *  trailing .name	entry in Dictionary
4415  *  trailing ->name()	method call
4416  *
4417  * "arg" must point to the first non-white of the expression.
4418  * "arg" is advanced to the next non-white after the recognized expression.
4419  *
4420  * Return OK or FAIL.
4421  */
4422     static int
4423 eval7(
4424     char_u	**arg,
4425     typval_T	*rettv,
4426     int		evaluate,
4427     int		want_string UNUSED)	/* after "." operator */
4428 {
4429     varnumber_T	n;
4430     int		len;
4431     char_u	*s;
4432     char_u	*start_leader, *end_leader;
4433     int		ret = OK;
4434     char_u	*alias;
4435 
4436     /*
4437      * Initialise variable so that clear_tv() can't mistake this for a
4438      * string and free a string that isn't there.
4439      */
4440     rettv->v_type = VAR_UNKNOWN;
4441 
4442     /*
4443      * Skip '!', '-' and '+' characters.  They are handled later.
4444      */
4445     start_leader = *arg;
4446     while (**arg == '!' || **arg == '-' || **arg == '+')
4447 	*arg = skipwhite(*arg + 1);
4448     end_leader = *arg;
4449 
4450     if (**arg == '.' && (!isdigit(*(*arg + 1))
4451 #ifdef FEAT_FLOAT
4452 	    || current_sctx.sc_version < 2
4453 #endif
4454 	    ))
4455     {
4456 	semsg(_(e_invexpr2), *arg);
4457 	++*arg;
4458 	return FAIL;
4459     }
4460 
4461     switch (**arg)
4462     {
4463     /*
4464      * Number constant.
4465      */
4466     case '0':
4467     case '1':
4468     case '2':
4469     case '3':
4470     case '4':
4471     case '5':
4472     case '6':
4473     case '7':
4474     case '8':
4475     case '9':
4476     case '.':
4477 	{
4478 #ifdef FEAT_FLOAT
4479 		char_u *p;
4480 		int    get_float = FALSE;
4481 
4482 		/* We accept a float when the format matches
4483 		 * "[0-9]\+\.[0-9]\+\([eE][+-]\?[0-9]\+\)\?".  This is very
4484 		 * strict to avoid backwards compatibility problems.
4485 		 * With script version 2 and later the leading digit can be
4486 		 * omitted.
4487 		 * Don't look for a float after the "." operator, so that
4488 		 * ":let vers = 1.2.3" doesn't fail. */
4489 		if (**arg == '.')
4490 		    p = *arg;
4491 		else
4492 		    p = skipdigits(*arg + 1);
4493 		if (!want_string && p[0] == '.' && vim_isdigit(p[1]))
4494 		{
4495 		    get_float = TRUE;
4496 		    p = skipdigits(p + 2);
4497 		    if (*p == 'e' || *p == 'E')
4498 		    {
4499 			++p;
4500 			if (*p == '-' || *p == '+')
4501 			    ++p;
4502 			if (!vim_isdigit(*p))
4503 			    get_float = FALSE;
4504 			else
4505 			    p = skipdigits(p + 1);
4506 		    }
4507 		    if (ASCII_ISALPHA(*p) || *p == '.')
4508 			get_float = FALSE;
4509 		}
4510 		if (get_float)
4511 		{
4512 		    float_T	f;
4513 
4514 		    *arg += string2float(*arg, &f);
4515 		    if (evaluate)
4516 		    {
4517 			rettv->v_type = VAR_FLOAT;
4518 			rettv->vval.v_float = f;
4519 		    }
4520 		}
4521 		else
4522 #endif
4523 		if (**arg == '0' && ((*arg)[1] == 'z' || (*arg)[1] == 'Z'))
4524 		{
4525 		    char_u  *bp;
4526 		    blob_T  *blob = NULL;  // init for gcc
4527 
4528 		    // Blob constant: 0z0123456789abcdef
4529 		    if (evaluate)
4530 			blob = blob_alloc();
4531 		    for (bp = *arg + 2; vim_isxdigit(bp[0]); bp += 2)
4532 		    {
4533 			if (!vim_isxdigit(bp[1]))
4534 			{
4535 			    if (blob != NULL)
4536 			    {
4537 				emsg(_("E973: Blob literal should have an even number of hex characters"));
4538 				ga_clear(&blob->bv_ga);
4539 				VIM_CLEAR(blob);
4540 			    }
4541 			    ret = FAIL;
4542 			    break;
4543 			}
4544 			if (blob != NULL)
4545 			    ga_append(&blob->bv_ga,
4546 					 (hex2nr(*bp) << 4) + hex2nr(*(bp+1)));
4547 			if (bp[2] == '.' && vim_isxdigit(bp[3]))
4548 			    ++bp;
4549 		    }
4550 		    if (blob != NULL)
4551 			rettv_blob_set(rettv, blob);
4552 		    *arg = bp;
4553 		}
4554 		else
4555 		{
4556 		    // decimal, hex or octal number
4557 		    vim_str2nr(*arg, NULL, &len, STR2NR_ALL, &n, NULL, 0, TRUE);
4558 		    if (len == 0)
4559 		    {
4560 			semsg(_(e_invexpr2), *arg);
4561 			ret = FAIL;
4562 			break;
4563 		    }
4564 		    *arg += len;
4565 		    if (evaluate)
4566 		    {
4567 			rettv->v_type = VAR_NUMBER;
4568 			rettv->vval.v_number = n;
4569 		    }
4570 		}
4571 		break;
4572 	}
4573 
4574     /*
4575      * String constant: "string".
4576      */
4577     case '"':	ret = get_string_tv(arg, rettv, evaluate);
4578 		break;
4579 
4580     /*
4581      * Literal string constant: 'str''ing'.
4582      */
4583     case '\'':	ret = get_lit_string_tv(arg, rettv, evaluate);
4584 		break;
4585 
4586     /*
4587      * List: [expr, expr]
4588      */
4589     case '[':	ret = get_list_tv(arg, rettv, evaluate);
4590 		break;
4591 
4592     /*
4593      * Dictionary: #{key: val, key: val}
4594      */
4595     case '#':	if ((*arg)[1] == '{')
4596 		{
4597 		    ++*arg;
4598 		    ret = dict_get_tv(arg, rettv, evaluate, TRUE);
4599 		}
4600 		else
4601 		    ret = NOTDONE;
4602 		break;
4603 
4604     /*
4605      * Lambda: {arg, arg -> expr}
4606      * Dictionary: {'key': val, 'key': val}
4607      */
4608     case '{':	ret = get_lambda_tv(arg, rettv, evaluate);
4609 		if (ret == NOTDONE)
4610 		    ret = dict_get_tv(arg, rettv, evaluate, FALSE);
4611 		break;
4612 
4613     /*
4614      * Option value: &name
4615      */
4616     case '&':	ret = get_option_tv(arg, rettv, evaluate);
4617 		break;
4618 
4619     /*
4620      * Environment variable: $VAR.
4621      */
4622     case '$':	ret = get_env_tv(arg, rettv, evaluate);
4623 		break;
4624 
4625     /*
4626      * Register contents: @r.
4627      */
4628     case '@':	++*arg;
4629 		if (evaluate)
4630 		{
4631 		    rettv->v_type = VAR_STRING;
4632 		    rettv->vval.v_string = get_reg_contents(**arg,
4633 							    GREG_EXPR_SRC);
4634 		}
4635 		if (**arg != NUL)
4636 		    ++*arg;
4637 		break;
4638 
4639     /*
4640      * nested expression: (expression).
4641      */
4642     case '(':	*arg = skipwhite(*arg + 1);
4643 		ret = eval1(arg, rettv, evaluate);	/* recursive! */
4644 		if (**arg == ')')
4645 		    ++*arg;
4646 		else if (ret == OK)
4647 		{
4648 		    emsg(_("E110: Missing ')'"));
4649 		    clear_tv(rettv);
4650 		    ret = FAIL;
4651 		}
4652 		break;
4653 
4654     default:	ret = NOTDONE;
4655 		break;
4656     }
4657 
4658     if (ret == NOTDONE)
4659     {
4660 	/*
4661 	 * Must be a variable or function name.
4662 	 * Can also be a curly-braces kind of name: {expr}.
4663 	 */
4664 	s = *arg;
4665 	len = get_name_len(arg, &alias, evaluate, TRUE);
4666 	if (alias != NULL)
4667 	    s = alias;
4668 
4669 	if (len <= 0)
4670 	    ret = FAIL;
4671 	else
4672 	{
4673 	    if (**arg == '(')		/* recursive! */
4674 	    {
4675 		partial_T *partial;
4676 
4677 		if (!evaluate)
4678 		    check_vars(s, len);
4679 
4680 		/* If "s" is the name of a variable of type VAR_FUNC
4681 		 * use its contents. */
4682 		s = deref_func_name(s, &len, &partial, !evaluate);
4683 
4684 		/* Need to make a copy, in case evaluating the arguments makes
4685 		 * the name invalid. */
4686 		s = vim_strsave(s);
4687 		if (s == NULL)
4688 		    ret = FAIL;
4689 		else
4690 		{
4691 		    funcexe_T funcexe;
4692 
4693 		    // Invoke the function.
4694 		    vim_memset(&funcexe, 0, sizeof(funcexe));
4695 		    funcexe.firstline = curwin->w_cursor.lnum;
4696 		    funcexe.lastline = curwin->w_cursor.lnum;
4697 		    funcexe.doesrange = &len;
4698 		    funcexe.evaluate = evaluate;
4699 		    funcexe.partial = partial;
4700 		    ret = get_func_tv(s, len, rettv, arg, &funcexe);
4701 		}
4702 		vim_free(s);
4703 
4704 		/* If evaluate is FALSE rettv->v_type was not set in
4705 		 * get_func_tv, but it's needed in handle_subscript() to parse
4706 		 * what follows. So set it here. */
4707 		if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
4708 		{
4709 		    rettv->vval.v_string = NULL;
4710 		    rettv->v_type = VAR_FUNC;
4711 		}
4712 
4713 		/* Stop the expression evaluation when immediately
4714 		 * aborting on error, or when an interrupt occurred or
4715 		 * an exception was thrown but not caught. */
4716 		if (evaluate && aborting())
4717 		{
4718 		    if (ret == OK)
4719 			clear_tv(rettv);
4720 		    ret = FAIL;
4721 		}
4722 	    }
4723 	    else if (evaluate)
4724 		ret = get_var_tv(s, len, rettv, NULL, TRUE, FALSE);
4725 	    else
4726 	    {
4727 		check_vars(s, len);
4728 		ret = OK;
4729 	    }
4730 	}
4731 	vim_free(alias);
4732     }
4733 
4734     *arg = skipwhite(*arg);
4735 
4736     /* Handle following '[', '(' and '.' for expr[expr], expr.name,
4737      * expr(expr), expr->name(expr) */
4738     if (ret == OK)
4739 	ret = handle_subscript(arg, rettv, evaluate, TRUE);
4740 
4741     /*
4742      * Apply logical NOT and unary '-', from right to left, ignore '+'.
4743      */
4744     if (ret == OK && evaluate && end_leader > start_leader)
4745     {
4746 	int	    error = FALSE;
4747 	varnumber_T val = 0;
4748 #ifdef FEAT_FLOAT
4749 	float_T	    f = 0.0;
4750 
4751 	if (rettv->v_type == VAR_FLOAT)
4752 	    f = rettv->vval.v_float;
4753 	else
4754 #endif
4755 	    val = tv_get_number_chk(rettv, &error);
4756 	if (error)
4757 	{
4758 	    clear_tv(rettv);
4759 	    ret = FAIL;
4760 	}
4761 	else
4762 	{
4763 	    while (end_leader > start_leader)
4764 	    {
4765 		--end_leader;
4766 		if (*end_leader == '!')
4767 		{
4768 #ifdef FEAT_FLOAT
4769 		    if (rettv->v_type == VAR_FLOAT)
4770 			f = !f;
4771 		    else
4772 #endif
4773 			val = !val;
4774 		}
4775 		else if (*end_leader == '-')
4776 		{
4777 #ifdef FEAT_FLOAT
4778 		    if (rettv->v_type == VAR_FLOAT)
4779 			f = -f;
4780 		    else
4781 #endif
4782 			val = -val;
4783 		}
4784 	    }
4785 #ifdef FEAT_FLOAT
4786 	    if (rettv->v_type == VAR_FLOAT)
4787 	    {
4788 		clear_tv(rettv);
4789 		rettv->vval.v_float = f;
4790 	    }
4791 	    else
4792 #endif
4793 	    {
4794 		clear_tv(rettv);
4795 		rettv->v_type = VAR_NUMBER;
4796 		rettv->vval.v_number = val;
4797 	    }
4798 	}
4799     }
4800 
4801     return ret;
4802 }
4803 
4804 /*
4805  * Evaluate "->method()".
4806  * "*arg" points to the '-'.
4807  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
4808  */
4809     static int
4810 eval_method(
4811     char_u	**arg,
4812     typval_T	*rettv,
4813     int		evaluate,
4814     int		verbose)	/* give error messages */
4815 {
4816     char_u	*name;
4817     long	len;
4818     funcexe_T	funcexe;
4819     int		ret = OK;
4820     typval_T	base = *rettv;
4821 
4822     // Skip over the ->.
4823     *arg += 2;
4824 
4825     // Locate the method name.
4826     name = *arg;
4827     for (len = 0; eval_isnamec(name[len]); ++len)
4828 	;
4829     if (len == 0)
4830     {
4831 	if (verbose)
4832 	    emsg(_("E260: Missing name after ->"));
4833 	return FAIL;
4834     }
4835 
4836     // Check for the "(".  Skip over white space after it.
4837     if (name[len] != '(')
4838     {
4839 	if (verbose)
4840 	    semsg(_(e_missingparen), name);
4841 	return FAIL;
4842     }
4843     *arg += len;
4844 
4845     // TODO: if "name" is a function reference, resolve it.
4846 
4847     vim_memset(&funcexe, 0, sizeof(funcexe));
4848     funcexe.evaluate = evaluate;
4849     funcexe.basetv = &base;
4850     rettv->v_type = VAR_UNKNOWN;
4851     ret = get_func_tv(name, len, rettv, arg, &funcexe);
4852 
4853     /* Clear the funcref afterwards, so that deleting it while
4854      * evaluating the arguments is possible (see test55). */
4855     if (evaluate)
4856 	clear_tv(&base);
4857 
4858     /* Stop the expression evaluation when immediately aborting on
4859      * error, or when an interrupt occurred or an exception was thrown
4860      * but not caught. */
4861     if (aborting())
4862     {
4863 	if (ret == OK)
4864 	    clear_tv(rettv);
4865 	ret = FAIL;
4866     }
4867     return ret;
4868 }
4869 
4870 /*
4871  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
4872  * "*arg" points to the '[' or '.'.
4873  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
4874  */
4875     static int
4876 eval_index(
4877     char_u	**arg,
4878     typval_T	*rettv,
4879     int		evaluate,
4880     int		verbose)	/* give error messages */
4881 {
4882     int		empty1 = FALSE, empty2 = FALSE;
4883     typval_T	var1, var2;
4884     long	i;
4885     long	n1, n2 = 0;
4886     long	len = -1;
4887     int		range = FALSE;
4888     char_u	*s;
4889     char_u	*key = NULL;
4890 
4891     switch (rettv->v_type)
4892     {
4893 	case VAR_FUNC:
4894 	case VAR_PARTIAL:
4895 	    if (verbose)
4896 		emsg(_("E695: Cannot index a Funcref"));
4897 	    return FAIL;
4898 	case VAR_FLOAT:
4899 #ifdef FEAT_FLOAT
4900 	    if (verbose)
4901 		emsg(_(e_float_as_string));
4902 	    return FAIL;
4903 #endif
4904 	case VAR_SPECIAL:
4905 	case VAR_JOB:
4906 	case VAR_CHANNEL:
4907 	    if (verbose)
4908 		emsg(_("E909: Cannot index a special variable"));
4909 	    return FAIL;
4910 	case VAR_UNKNOWN:
4911 	    if (evaluate)
4912 		return FAIL;
4913 	    /* FALLTHROUGH */
4914 
4915 	case VAR_STRING:
4916 	case VAR_NUMBER:
4917 	case VAR_LIST:
4918 	case VAR_DICT:
4919 	case VAR_BLOB:
4920 	    break;
4921     }
4922 
4923     init_tv(&var1);
4924     init_tv(&var2);
4925     if (**arg == '.')
4926     {
4927 	/*
4928 	 * dict.name
4929 	 */
4930 	key = *arg + 1;
4931 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
4932 	    ;
4933 	if (len == 0)
4934 	    return FAIL;
4935 	*arg = skipwhite(key + len);
4936     }
4937     else
4938     {
4939 	/*
4940 	 * something[idx]
4941 	 *
4942 	 * Get the (first) variable from inside the [].
4943 	 */
4944 	*arg = skipwhite(*arg + 1);
4945 	if (**arg == ':')
4946 	    empty1 = TRUE;
4947 	else if (eval1(arg, &var1, evaluate) == FAIL)	/* recursive! */
4948 	    return FAIL;
4949 	else if (evaluate && tv_get_string_chk(&var1) == NULL)
4950 	{
4951 	    /* not a number or string */
4952 	    clear_tv(&var1);
4953 	    return FAIL;
4954 	}
4955 
4956 	/*
4957 	 * Get the second variable from inside the [:].
4958 	 */
4959 	if (**arg == ':')
4960 	{
4961 	    range = TRUE;
4962 	    *arg = skipwhite(*arg + 1);
4963 	    if (**arg == ']')
4964 		empty2 = TRUE;
4965 	    else if (eval1(arg, &var2, evaluate) == FAIL)	/* recursive! */
4966 	    {
4967 		if (!empty1)
4968 		    clear_tv(&var1);
4969 		return FAIL;
4970 	    }
4971 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
4972 	    {
4973 		/* not a number or string */
4974 		if (!empty1)
4975 		    clear_tv(&var1);
4976 		clear_tv(&var2);
4977 		return FAIL;
4978 	    }
4979 	}
4980 
4981 	/* Check for the ']'. */
4982 	if (**arg != ']')
4983 	{
4984 	    if (verbose)
4985 		emsg(_(e_missbrac));
4986 	    clear_tv(&var1);
4987 	    if (range)
4988 		clear_tv(&var2);
4989 	    return FAIL;
4990 	}
4991 	*arg = skipwhite(*arg + 1);	/* skip the ']' */
4992     }
4993 
4994     if (evaluate)
4995     {
4996 	n1 = 0;
4997 	if (!empty1 && rettv->v_type != VAR_DICT)
4998 	{
4999 	    n1 = tv_get_number(&var1);
5000 	    clear_tv(&var1);
5001 	}
5002 	if (range)
5003 	{
5004 	    if (empty2)
5005 		n2 = -1;
5006 	    else
5007 	    {
5008 		n2 = tv_get_number(&var2);
5009 		clear_tv(&var2);
5010 	    }
5011 	}
5012 
5013 	switch (rettv->v_type)
5014 	{
5015 	    case VAR_UNKNOWN:
5016 	    case VAR_FUNC:
5017 	    case VAR_PARTIAL:
5018 	    case VAR_FLOAT:
5019 	    case VAR_SPECIAL:
5020 	    case VAR_JOB:
5021 	    case VAR_CHANNEL:
5022 		break; /* not evaluating, skipping over subscript */
5023 
5024 	    case VAR_NUMBER:
5025 	    case VAR_STRING:
5026 		s = tv_get_string(rettv);
5027 		len = (long)STRLEN(s);
5028 		if (range)
5029 		{
5030 		    /* The resulting variable is a substring.  If the indexes
5031 		     * are out of range the result is empty. */
5032 		    if (n1 < 0)
5033 		    {
5034 			n1 = len + n1;
5035 			if (n1 < 0)
5036 			    n1 = 0;
5037 		    }
5038 		    if (n2 < 0)
5039 			n2 = len + n2;
5040 		    else if (n2 >= len)
5041 			n2 = len;
5042 		    if (n1 >= len || n2 < 0 || n1 > n2)
5043 			s = NULL;
5044 		    else
5045 			s = vim_strnsave(s + n1, (int)(n2 - n1 + 1));
5046 		}
5047 		else
5048 		{
5049 		    /* The resulting variable is a string of a single
5050 		     * character.  If the index is too big or negative the
5051 		     * result is empty. */
5052 		    if (n1 >= len || n1 < 0)
5053 			s = NULL;
5054 		    else
5055 			s = vim_strnsave(s + n1, 1);
5056 		}
5057 		clear_tv(rettv);
5058 		rettv->v_type = VAR_STRING;
5059 		rettv->vval.v_string = s;
5060 		break;
5061 
5062 	    case VAR_BLOB:
5063 		len = blob_len(rettv->vval.v_blob);
5064 		if (range)
5065 		{
5066 		    // The resulting variable is a sub-blob.  If the indexes
5067 		    // are out of range the result is empty.
5068 		    if (n1 < 0)
5069 		    {
5070 			n1 = len + n1;
5071 			if (n1 < 0)
5072 			    n1 = 0;
5073 		    }
5074 		    if (n2 < 0)
5075 			n2 = len + n2;
5076 		    else if (n2 >= len)
5077 			n2 = len - 1;
5078 		    if (n1 >= len || n2 < 0 || n1 > n2)
5079 		    {
5080 			clear_tv(rettv);
5081 			rettv->v_type = VAR_BLOB;
5082 			rettv->vval.v_blob = NULL;
5083 		    }
5084 		    else
5085 		    {
5086 			blob_T  *blob = blob_alloc();
5087 
5088 			if (blob != NULL)
5089 			{
5090 			    if (ga_grow(&blob->bv_ga, n2 - n1 + 1) == FAIL)
5091 			    {
5092 				blob_free(blob);
5093 				return FAIL;
5094 			    }
5095 			    blob->bv_ga.ga_len = n2 - n1 + 1;
5096 			    for (i = n1; i <= n2; i++)
5097 				blob_set(blob, i - n1,
5098 					      blob_get(rettv->vval.v_blob, i));
5099 
5100 			    clear_tv(rettv);
5101 			    rettv_blob_set(rettv, blob);
5102 			}
5103 		    }
5104 		}
5105 		else
5106 		{
5107 		    // The resulting variable is a byte value.
5108 		    // If the index is too big or negative that is an error.
5109 		    if (n1 < 0)
5110 			n1 = len + n1;
5111 		    if (n1 < len && n1 >= 0)
5112 		    {
5113 			int v = blob_get(rettv->vval.v_blob, n1);
5114 
5115 			clear_tv(rettv);
5116 			rettv->v_type = VAR_NUMBER;
5117 			rettv->vval.v_number = v;
5118 		    }
5119 		    else
5120 			semsg(_(e_blobidx), n1);
5121 		}
5122 		break;
5123 
5124 	    case VAR_LIST:
5125 		len = list_len(rettv->vval.v_list);
5126 		if (n1 < 0)
5127 		    n1 = len + n1;
5128 		if (!empty1 && (n1 < 0 || n1 >= len))
5129 		{
5130 		    /* For a range we allow invalid values and return an empty
5131 		     * list.  A list index out of range is an error. */
5132 		    if (!range)
5133 		    {
5134 			if (verbose)
5135 			    semsg(_(e_listidx), n1);
5136 			return FAIL;
5137 		    }
5138 		    n1 = len;
5139 		}
5140 		if (range)
5141 		{
5142 		    list_T	*l;
5143 		    listitem_T	*item;
5144 
5145 		    if (n2 < 0)
5146 			n2 = len + n2;
5147 		    else if (n2 >= len)
5148 			n2 = len - 1;
5149 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
5150 			n2 = -1;
5151 		    l = list_alloc();
5152 		    if (l == NULL)
5153 			return FAIL;
5154 		    for (item = list_find(rettv->vval.v_list, n1);
5155 							       n1 <= n2; ++n1)
5156 		    {
5157 			if (list_append_tv(l, &item->li_tv) == FAIL)
5158 			{
5159 			    list_free(l);
5160 			    return FAIL;
5161 			}
5162 			item = item->li_next;
5163 		    }
5164 		    clear_tv(rettv);
5165 		    rettv_list_set(rettv, l);
5166 		}
5167 		else
5168 		{
5169 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
5170 		    clear_tv(rettv);
5171 		    *rettv = var1;
5172 		}
5173 		break;
5174 
5175 	    case VAR_DICT:
5176 		if (range)
5177 		{
5178 		    if (verbose)
5179 			emsg(_(e_dictrange));
5180 		    if (len == -1)
5181 			clear_tv(&var1);
5182 		    return FAIL;
5183 		}
5184 		{
5185 		    dictitem_T	*item;
5186 
5187 		    if (len == -1)
5188 		    {
5189 			key = tv_get_string_chk(&var1);
5190 			if (key == NULL)
5191 			{
5192 			    clear_tv(&var1);
5193 			    return FAIL;
5194 			}
5195 		    }
5196 
5197 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
5198 
5199 		    if (item == NULL && verbose)
5200 			semsg(_(e_dictkey), key);
5201 		    if (len == -1)
5202 			clear_tv(&var1);
5203 		    if (item == NULL)
5204 			return FAIL;
5205 
5206 		    copy_tv(&item->di_tv, &var1);
5207 		    clear_tv(rettv);
5208 		    *rettv = var1;
5209 		}
5210 		break;
5211 	}
5212     }
5213 
5214     return OK;
5215 }
5216 
5217 /*
5218  * Get an option value.
5219  * "arg" points to the '&' or '+' before the option name.
5220  * "arg" is advanced to character after the option name.
5221  * Return OK or FAIL.
5222  */
5223     int
5224 get_option_tv(
5225     char_u	**arg,
5226     typval_T	*rettv,	/* when NULL, only check if option exists */
5227     int		evaluate)
5228 {
5229     char_u	*option_end;
5230     long	numval;
5231     char_u	*stringval;
5232     int		opt_type;
5233     int		c;
5234     int		working = (**arg == '+');    /* has("+option") */
5235     int		ret = OK;
5236     int		opt_flags;
5237 
5238     /*
5239      * Isolate the option name and find its value.
5240      */
5241     option_end = find_option_end(arg, &opt_flags);
5242     if (option_end == NULL)
5243     {
5244 	if (rettv != NULL)
5245 	    semsg(_("E112: Option name missing: %s"), *arg);
5246 	return FAIL;
5247     }
5248 
5249     if (!evaluate)
5250     {
5251 	*arg = option_end;
5252 	return OK;
5253     }
5254 
5255     c = *option_end;
5256     *option_end = NUL;
5257     opt_type = get_option_value(*arg, &numval,
5258 			       rettv == NULL ? NULL : &stringval, opt_flags);
5259 
5260     if (opt_type == -3)			/* invalid name */
5261     {
5262 	if (rettv != NULL)
5263 	    semsg(_("E113: Unknown option: %s"), *arg);
5264 	ret = FAIL;
5265     }
5266     else if (rettv != NULL)
5267     {
5268 	if (opt_type == -2)		/* hidden string option */
5269 	{
5270 	    rettv->v_type = VAR_STRING;
5271 	    rettv->vval.v_string = NULL;
5272 	}
5273 	else if (opt_type == -1)	/* hidden number option */
5274 	{
5275 	    rettv->v_type = VAR_NUMBER;
5276 	    rettv->vval.v_number = 0;
5277 	}
5278 	else if (opt_type == 1)		/* number option */
5279 	{
5280 	    rettv->v_type = VAR_NUMBER;
5281 	    rettv->vval.v_number = numval;
5282 	}
5283 	else				/* string option */
5284 	{
5285 	    rettv->v_type = VAR_STRING;
5286 	    rettv->vval.v_string = stringval;
5287 	}
5288     }
5289     else if (working && (opt_type == -2 || opt_type == -1))
5290 	ret = FAIL;
5291 
5292     *option_end = c;		    /* put back for error messages */
5293     *arg = option_end;
5294 
5295     return ret;
5296 }
5297 
5298 /*
5299  * Allocate a variable for a string constant.
5300  * Return OK or FAIL.
5301  */
5302     static int
5303 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
5304 {
5305     char_u	*p;
5306     char_u	*name;
5307     int		extra = 0;
5308 
5309     /*
5310      * Find the end of the string, skipping backslashed characters.
5311      */
5312     for (p = *arg + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5313     {
5314 	if (*p == '\\' && p[1] != NUL)
5315 	{
5316 	    ++p;
5317 	    /* A "\<x>" form occupies at least 4 characters, and produces up
5318 	     * to 6 characters: reserve space for 2 extra */
5319 	    if (*p == '<')
5320 		extra += 2;
5321 	}
5322     }
5323 
5324     if (*p != '"')
5325     {
5326 	semsg(_("E114: Missing quote: %s"), *arg);
5327 	return FAIL;
5328     }
5329 
5330     /* If only parsing, set *arg and return here */
5331     if (!evaluate)
5332     {
5333 	*arg = p + 1;
5334 	return OK;
5335     }
5336 
5337     /*
5338      * Copy the string into allocated memory, handling backslashed
5339      * characters.
5340      */
5341     name = alloc(p - *arg + extra);
5342     if (name == NULL)
5343 	return FAIL;
5344     rettv->v_type = VAR_STRING;
5345     rettv->vval.v_string = name;
5346 
5347     for (p = *arg + 1; *p != NUL && *p != '"'; )
5348     {
5349 	if (*p == '\\')
5350 	{
5351 	    switch (*++p)
5352 	    {
5353 		case 'b': *name++ = BS; ++p; break;
5354 		case 'e': *name++ = ESC; ++p; break;
5355 		case 'f': *name++ = FF; ++p; break;
5356 		case 'n': *name++ = NL; ++p; break;
5357 		case 'r': *name++ = CAR; ++p; break;
5358 		case 't': *name++ = TAB; ++p; break;
5359 
5360 		case 'X': /* hex: "\x1", "\x12" */
5361 		case 'x':
5362 		case 'u': /* Unicode: "\u0023" */
5363 		case 'U':
5364 			  if (vim_isxdigit(p[1]))
5365 			  {
5366 			      int	n, nr;
5367 			      int	c = toupper(*p);
5368 
5369 			      if (c == 'X')
5370 				  n = 2;
5371 			      else if (*p == 'u')
5372 				  n = 4;
5373 			      else
5374 				  n = 8;
5375 			      nr = 0;
5376 			      while (--n >= 0 && vim_isxdigit(p[1]))
5377 			      {
5378 				  ++p;
5379 				  nr = (nr << 4) + hex2nr(*p);
5380 			      }
5381 			      ++p;
5382 			      /* For "\u" store the number according to
5383 			       * 'encoding'. */
5384 			      if (c != 'X')
5385 				  name += (*mb_char2bytes)(nr, name);
5386 			      else
5387 				  *name++ = nr;
5388 			  }
5389 			  break;
5390 
5391 			  /* octal: "\1", "\12", "\123" */
5392 		case '0':
5393 		case '1':
5394 		case '2':
5395 		case '3':
5396 		case '4':
5397 		case '5':
5398 		case '6':
5399 		case '7': *name = *p++ - '0';
5400 			  if (*p >= '0' && *p <= '7')
5401 			  {
5402 			      *name = (*name << 3) + *p++ - '0';
5403 			      if (*p >= '0' && *p <= '7')
5404 				  *name = (*name << 3) + *p++ - '0';
5405 			  }
5406 			  ++name;
5407 			  break;
5408 
5409 			    /* Special key, e.g.: "\<C-W>" */
5410 		case '<': extra = trans_special(&p, name, TRUE, TRUE);
5411 			  if (extra != 0)
5412 			  {
5413 			      name += extra;
5414 			      break;
5415 			  }
5416 			  /* FALLTHROUGH */
5417 
5418 		default:  MB_COPY_CHAR(p, name);
5419 			  break;
5420 	    }
5421 	}
5422 	else
5423 	    MB_COPY_CHAR(p, name);
5424 
5425     }
5426     *name = NUL;
5427     if (*p != NUL) /* just in case */
5428 	++p;
5429     *arg = p;
5430 
5431     return OK;
5432 }
5433 
5434 /*
5435  * Allocate a variable for a 'str''ing' constant.
5436  * Return OK or FAIL.
5437  */
5438     static int
5439 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
5440 {
5441     char_u	*p;
5442     char_u	*str;
5443     int		reduce = 0;
5444 
5445     /*
5446      * Find the end of the string, skipping ''.
5447      */
5448     for (p = *arg + 1; *p != NUL; MB_PTR_ADV(p))
5449     {
5450 	if (*p == '\'')
5451 	{
5452 	    if (p[1] != '\'')
5453 		break;
5454 	    ++reduce;
5455 	    ++p;
5456 	}
5457     }
5458 
5459     if (*p != '\'')
5460     {
5461 	semsg(_("E115: Missing quote: %s"), *arg);
5462 	return FAIL;
5463     }
5464 
5465     /* If only parsing return after setting "*arg" */
5466     if (!evaluate)
5467     {
5468 	*arg = p + 1;
5469 	return OK;
5470     }
5471 
5472     /*
5473      * Copy the string into allocated memory, handling '' to ' reduction.
5474      */
5475     str = alloc((p - *arg) - reduce);
5476     if (str == NULL)
5477 	return FAIL;
5478     rettv->v_type = VAR_STRING;
5479     rettv->vval.v_string = str;
5480 
5481     for (p = *arg + 1; *p != NUL; )
5482     {
5483 	if (*p == '\'')
5484 	{
5485 	    if (p[1] != '\'')
5486 		break;
5487 	    ++p;
5488 	}
5489 	MB_COPY_CHAR(p, str);
5490     }
5491     *str = NUL;
5492     *arg = p + 1;
5493 
5494     return OK;
5495 }
5496 
5497 /*
5498  * Return the function name of the partial.
5499  */
5500     char_u *
5501 partial_name(partial_T *pt)
5502 {
5503     if (pt->pt_name != NULL)
5504 	return pt->pt_name;
5505     return pt->pt_func->uf_name;
5506 }
5507 
5508     static void
5509 partial_free(partial_T *pt)
5510 {
5511     int i;
5512 
5513     for (i = 0; i < pt->pt_argc; ++i)
5514 	clear_tv(&pt->pt_argv[i]);
5515     vim_free(pt->pt_argv);
5516     dict_unref(pt->pt_dict);
5517     if (pt->pt_name != NULL)
5518     {
5519 	func_unref(pt->pt_name);
5520 	vim_free(pt->pt_name);
5521     }
5522     else
5523 	func_ptr_unref(pt->pt_func);
5524     vim_free(pt);
5525 }
5526 
5527 /*
5528  * Unreference a closure: decrement the reference count and free it when it
5529  * becomes zero.
5530  */
5531     void
5532 partial_unref(partial_T *pt)
5533 {
5534     if (pt != NULL && --pt->pt_refcount <= 0)
5535 	partial_free(pt);
5536 }
5537 
5538 static int tv_equal_recurse_limit;
5539 
5540     static int
5541 func_equal(
5542     typval_T *tv1,
5543     typval_T *tv2,
5544     int	     ic)	    /* ignore case */
5545 {
5546     char_u	*s1, *s2;
5547     dict_T	*d1, *d2;
5548     int		a1, a2;
5549     int		i;
5550 
5551     /* empty and NULL function name considered the same */
5552     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
5553 					   : partial_name(tv1->vval.v_partial);
5554     if (s1 != NULL && *s1 == NUL)
5555 	s1 = NULL;
5556     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
5557 					   : partial_name(tv2->vval.v_partial);
5558     if (s2 != NULL && *s2 == NUL)
5559 	s2 = NULL;
5560     if (s1 == NULL || s2 == NULL)
5561     {
5562 	if (s1 != s2)
5563 	    return FALSE;
5564     }
5565     else if (STRCMP(s1, s2) != 0)
5566 	return FALSE;
5567 
5568     /* empty dict and NULL dict is different */
5569     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
5570     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
5571     if (d1 == NULL || d2 == NULL)
5572     {
5573 	if (d1 != d2)
5574 	    return FALSE;
5575     }
5576     else if (!dict_equal(d1, d2, ic, TRUE))
5577 	return FALSE;
5578 
5579     /* empty list and no list considered the same */
5580     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
5581     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
5582     if (a1 != a2)
5583 	return FALSE;
5584     for (i = 0; i < a1; ++i)
5585 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
5586 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
5587 	    return FALSE;
5588 
5589     return TRUE;
5590 }
5591 
5592 /*
5593  * Return TRUE if "tv1" and "tv2" have the same value.
5594  * Compares the items just like "==" would compare them, but strings and
5595  * numbers are different.  Floats and numbers are also different.
5596  */
5597     int
5598 tv_equal(
5599     typval_T *tv1,
5600     typval_T *tv2,
5601     int	     ic,	    /* ignore case */
5602     int	     recursive)	    /* TRUE when used recursively */
5603 {
5604     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
5605     char_u	*s1, *s2;
5606     static int  recursive_cnt = 0;	    /* catch recursive loops */
5607     int		r;
5608 
5609     /* Catch lists and dicts that have an endless loop by limiting
5610      * recursiveness to a limit.  We guess they are equal then.
5611      * A fixed limit has the problem of still taking an awful long time.
5612      * Reduce the limit every time running into it. That should work fine for
5613      * deeply linked structures that are not recursively linked and catch
5614      * recursiveness quickly. */
5615     if (!recursive)
5616 	tv_equal_recurse_limit = 1000;
5617     if (recursive_cnt >= tv_equal_recurse_limit)
5618     {
5619 	--tv_equal_recurse_limit;
5620 	return TRUE;
5621     }
5622 
5623     /* For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
5624      * arguments. */
5625     if ((tv1->v_type == VAR_FUNC
5626 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
5627 	    && (tv2->v_type == VAR_FUNC
5628 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
5629     {
5630 	++recursive_cnt;
5631 	r = func_equal(tv1, tv2, ic);
5632 	--recursive_cnt;
5633 	return r;
5634     }
5635 
5636     if (tv1->v_type != tv2->v_type)
5637 	return FALSE;
5638 
5639     switch (tv1->v_type)
5640     {
5641 	case VAR_LIST:
5642 	    ++recursive_cnt;
5643 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
5644 	    --recursive_cnt;
5645 	    return r;
5646 
5647 	case VAR_DICT:
5648 	    ++recursive_cnt;
5649 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
5650 	    --recursive_cnt;
5651 	    return r;
5652 
5653 	case VAR_BLOB:
5654 	    return blob_equal(tv1->vval.v_blob, tv2->vval.v_blob);
5655 
5656 	case VAR_NUMBER:
5657 	    return tv1->vval.v_number == tv2->vval.v_number;
5658 
5659 	case VAR_STRING:
5660 	    s1 = tv_get_string_buf(tv1, buf1);
5661 	    s2 = tv_get_string_buf(tv2, buf2);
5662 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
5663 
5664 	case VAR_SPECIAL:
5665 	    return tv1->vval.v_number == tv2->vval.v_number;
5666 
5667 	case VAR_FLOAT:
5668 #ifdef FEAT_FLOAT
5669 	    return tv1->vval.v_float == tv2->vval.v_float;
5670 #endif
5671 	case VAR_JOB:
5672 #ifdef FEAT_JOB_CHANNEL
5673 	    return tv1->vval.v_job == tv2->vval.v_job;
5674 #endif
5675 	case VAR_CHANNEL:
5676 #ifdef FEAT_JOB_CHANNEL
5677 	    return tv1->vval.v_channel == tv2->vval.v_channel;
5678 #endif
5679 	case VAR_FUNC:
5680 	case VAR_PARTIAL:
5681 	case VAR_UNKNOWN:
5682 	    break;
5683     }
5684 
5685     /* VAR_UNKNOWN can be the result of a invalid expression, let's say it
5686      * does not equal anything, not even itself. */
5687     return FALSE;
5688 }
5689 
5690 /*
5691  * Return the next (unique) copy ID.
5692  * Used for serializing nested structures.
5693  */
5694     int
5695 get_copyID(void)
5696 {
5697     current_copyID += COPYID_INC;
5698     return current_copyID;
5699 }
5700 
5701 /*
5702  * Garbage collection for lists and dictionaries.
5703  *
5704  * We use reference counts to be able to free most items right away when they
5705  * are no longer used.  But for composite items it's possible that it becomes
5706  * unused while the reference count is > 0: When there is a recursive
5707  * reference.  Example:
5708  *	:let l = [1, 2, 3]
5709  *	:let d = {9: l}
5710  *	:let l[1] = d
5711  *
5712  * Since this is quite unusual we handle this with garbage collection: every
5713  * once in a while find out which lists and dicts are not referenced from any
5714  * variable.
5715  *
5716  * Here is a good reference text about garbage collection (refers to Python
5717  * but it applies to all reference-counting mechanisms):
5718  *	http://python.ca/nas/python/gc/
5719  */
5720 
5721 /*
5722  * Do garbage collection for lists and dicts.
5723  * When "testing" is TRUE this is called from test_garbagecollect_now().
5724  * Return TRUE if some memory was freed.
5725  */
5726     int
5727 garbage_collect(int testing)
5728 {
5729     int		copyID;
5730     int		abort = FALSE;
5731     buf_T	*buf;
5732     win_T	*wp;
5733     int		i;
5734     int		did_free = FALSE;
5735     tabpage_T	*tp;
5736 
5737     if (!testing)
5738     {
5739 	/* Only do this once. */
5740 	want_garbage_collect = FALSE;
5741 	may_garbage_collect = FALSE;
5742 	garbage_collect_at_exit = FALSE;
5743     }
5744 
5745     /* We advance by two because we add one for items referenced through
5746      * previous_funccal. */
5747     copyID = get_copyID();
5748 
5749     /*
5750      * 1. Go through all accessible variables and mark all lists and dicts
5751      *    with copyID.
5752      */
5753 
5754     /* Don't free variables in the previous_funccal list unless they are only
5755      * referenced through previous_funccal.  This must be first, because if
5756      * the item is referenced elsewhere the funccal must not be freed. */
5757     abort = abort || set_ref_in_previous_funccal(copyID);
5758 
5759     /* script-local variables */
5760     for (i = 1; i <= ga_scripts.ga_len; ++i)
5761 	abort = abort || set_ref_in_ht(&SCRIPT_VARS(i), copyID, NULL);
5762 
5763     /* buffer-local variables */
5764     FOR_ALL_BUFFERS(buf)
5765 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
5766 								  NULL, NULL);
5767 
5768     /* window-local variables */
5769     FOR_ALL_TAB_WINDOWS(tp, wp)
5770 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
5771 								  NULL, NULL);
5772     if (aucmd_win != NULL)
5773 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
5774 								  NULL, NULL);
5775 #ifdef FEAT_TEXT_PROP
5776     for (wp = first_popupwin; wp != NULL; wp = wp->w_next)
5777 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
5778 								  NULL, NULL);
5779     FOR_ALL_TABPAGES(tp)
5780 	for (wp = tp->tp_first_popupwin; wp != NULL; wp = wp->w_next)
5781 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
5782 								  NULL, NULL);
5783 #endif
5784 
5785     /* tabpage-local variables */
5786     FOR_ALL_TABPAGES(tp)
5787 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
5788 								  NULL, NULL);
5789     /* global variables */
5790     abort = abort || set_ref_in_ht(&globvarht, copyID, NULL);
5791 
5792     /* function-local variables */
5793     abort = abort || set_ref_in_call_stack(copyID);
5794 
5795     /* named functions (matters for closures) */
5796     abort = abort || set_ref_in_functions(copyID);
5797 
5798     /* function call arguments, if v:testing is set. */
5799     abort = abort || set_ref_in_func_args(copyID);
5800 
5801     /* v: vars */
5802     abort = abort || set_ref_in_ht(&vimvarht, copyID, NULL);
5803 
5804     // callbacks in buffers
5805     abort = abort || set_ref_in_buffers(copyID);
5806 
5807 #ifdef FEAT_LUA
5808     abort = abort || set_ref_in_lua(copyID);
5809 #endif
5810 
5811 #ifdef FEAT_PYTHON
5812     abort = abort || set_ref_in_python(copyID);
5813 #endif
5814 
5815 #ifdef FEAT_PYTHON3
5816     abort = abort || set_ref_in_python3(copyID);
5817 #endif
5818 
5819 #ifdef FEAT_JOB_CHANNEL
5820     abort = abort || set_ref_in_channel(copyID);
5821     abort = abort || set_ref_in_job(copyID);
5822 #endif
5823 #ifdef FEAT_NETBEANS_INTG
5824     abort = abort || set_ref_in_nb_channel(copyID);
5825 #endif
5826 
5827 #ifdef FEAT_TIMERS
5828     abort = abort || set_ref_in_timer(copyID);
5829 #endif
5830 
5831 #ifdef FEAT_QUICKFIX
5832     abort = abort || set_ref_in_quickfix(copyID);
5833 #endif
5834 
5835 #ifdef FEAT_TERMINAL
5836     abort = abort || set_ref_in_term(copyID);
5837 #endif
5838 
5839 #ifdef FEAT_TEXT_PROP
5840     abort = abort || set_ref_in_popups(copyID);
5841 #endif
5842 
5843     if (!abort)
5844     {
5845 	/*
5846 	 * 2. Free lists and dictionaries that are not referenced.
5847 	 */
5848 	did_free = free_unref_items(copyID);
5849 
5850 	/*
5851 	 * 3. Check if any funccal can be freed now.
5852 	 *    This may call us back recursively.
5853 	 */
5854 	free_unref_funccal(copyID, testing);
5855     }
5856     else if (p_verbose > 0)
5857     {
5858 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
5859     }
5860 
5861     return did_free;
5862 }
5863 
5864 /*
5865  * Free lists, dictionaries, channels and jobs that are no longer referenced.
5866  */
5867     static int
5868 free_unref_items(int copyID)
5869 {
5870     int		did_free = FALSE;
5871 
5872     /* Let all "free" functions know that we are here.  This means no
5873      * dictionaries, lists, channels or jobs are to be freed, because we will
5874      * do that here. */
5875     in_free_unref_items = TRUE;
5876 
5877     /*
5878      * PASS 1: free the contents of the items.  We don't free the items
5879      * themselves yet, so that it is possible to decrement refcount counters
5880      */
5881 
5882     /* Go through the list of dicts and free items without the copyID. */
5883     did_free |= dict_free_nonref(copyID);
5884 
5885     /* Go through the list of lists and free items without the copyID. */
5886     did_free |= list_free_nonref(copyID);
5887 
5888 #ifdef FEAT_JOB_CHANNEL
5889     /* Go through the list of jobs and free items without the copyID. This
5890      * must happen before doing channels, because jobs refer to channels, but
5891      * the reference from the channel to the job isn't tracked. */
5892     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
5893 
5894     /* Go through the list of channels and free items without the copyID.  */
5895     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
5896 #endif
5897 
5898     /*
5899      * PASS 2: free the items themselves.
5900      */
5901     dict_free_items(copyID);
5902     list_free_items(copyID);
5903 
5904 #ifdef FEAT_JOB_CHANNEL
5905     /* Go through the list of jobs and free items without the copyID. This
5906      * must happen before doing channels, because jobs refer to channels, but
5907      * the reference from the channel to the job isn't tracked. */
5908     free_unused_jobs(copyID, COPYID_MASK);
5909 
5910     /* Go through the list of channels and free items without the copyID.  */
5911     free_unused_channels(copyID, COPYID_MASK);
5912 #endif
5913 
5914     in_free_unref_items = FALSE;
5915 
5916     return did_free;
5917 }
5918 
5919 /*
5920  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
5921  * "list_stack" is used to add lists to be marked.  Can be NULL.
5922  *
5923  * Returns TRUE if setting references failed somehow.
5924  */
5925     int
5926 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
5927 {
5928     int		todo;
5929     int		abort = FALSE;
5930     hashitem_T	*hi;
5931     hashtab_T	*cur_ht;
5932     ht_stack_T	*ht_stack = NULL;
5933     ht_stack_T	*tempitem;
5934 
5935     cur_ht = ht;
5936     for (;;)
5937     {
5938 	if (!abort)
5939 	{
5940 	    /* Mark each item in the hashtab.  If the item contains a hashtab
5941 	     * it is added to ht_stack, if it contains a list it is added to
5942 	     * list_stack. */
5943 	    todo = (int)cur_ht->ht_used;
5944 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
5945 		if (!HASHITEM_EMPTY(hi))
5946 		{
5947 		    --todo;
5948 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
5949 						       &ht_stack, list_stack);
5950 		}
5951 	}
5952 
5953 	if (ht_stack == NULL)
5954 	    break;
5955 
5956 	/* take an item from the stack */
5957 	cur_ht = ht_stack->ht;
5958 	tempitem = ht_stack;
5959 	ht_stack = ht_stack->prev;
5960 	free(tempitem);
5961     }
5962 
5963     return abort;
5964 }
5965 
5966 /*
5967  * Mark a dict and its items with "copyID".
5968  * Returns TRUE if setting references failed somehow.
5969  */
5970     int
5971 set_ref_in_dict(dict_T *d, int copyID)
5972 {
5973     if (d != NULL && d->dv_copyID != copyID)
5974     {
5975 	d->dv_copyID = copyID;
5976 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
5977     }
5978     return FALSE;
5979 }
5980 
5981 /*
5982  * Mark a list and its items with "copyID".
5983  * Returns TRUE if setting references failed somehow.
5984  */
5985     int
5986 set_ref_in_list(list_T *ll, int copyID)
5987 {
5988     if (ll != NULL && ll->lv_copyID != copyID)
5989     {
5990 	ll->lv_copyID = copyID;
5991 	return set_ref_in_list_items(ll, copyID, NULL);
5992     }
5993     return FALSE;
5994 }
5995 
5996 /*
5997  * Mark all lists and dicts referenced through list "l" with "copyID".
5998  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5999  *
6000  * Returns TRUE if setting references failed somehow.
6001  */
6002     int
6003 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
6004 {
6005     listitem_T	 *li;
6006     int		 abort = FALSE;
6007     list_T	 *cur_l;
6008     list_stack_T *list_stack = NULL;
6009     list_stack_T *tempitem;
6010 
6011     cur_l = l;
6012     for (;;)
6013     {
6014 	if (!abort)
6015 	    /* Mark each item in the list.  If the item contains a hashtab
6016 	     * it is added to ht_stack, if it contains a list it is added to
6017 	     * list_stack. */
6018 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
6019 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
6020 						       ht_stack, &list_stack);
6021 	if (list_stack == NULL)
6022 	    break;
6023 
6024 	/* take an item from the stack */
6025 	cur_l = list_stack->list;
6026 	tempitem = list_stack;
6027 	list_stack = list_stack->prev;
6028 	free(tempitem);
6029     }
6030 
6031     return abort;
6032 }
6033 
6034 /*
6035  * Mark all lists and dicts referenced through typval "tv" with "copyID".
6036  * "list_stack" is used to add lists to be marked.  Can be NULL.
6037  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
6038  *
6039  * Returns TRUE if setting references failed somehow.
6040  */
6041     int
6042 set_ref_in_item(
6043     typval_T	    *tv,
6044     int		    copyID,
6045     ht_stack_T	    **ht_stack,
6046     list_stack_T    **list_stack)
6047 {
6048     int		abort = FALSE;
6049 
6050     if (tv->v_type == VAR_DICT)
6051     {
6052 	dict_T	*dd = tv->vval.v_dict;
6053 
6054 	if (dd != NULL && dd->dv_copyID != copyID)
6055 	{
6056 	    /* Didn't see this dict yet. */
6057 	    dd->dv_copyID = copyID;
6058 	    if (ht_stack == NULL)
6059 	    {
6060 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
6061 	    }
6062 	    else
6063 	    {
6064 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
6065 		if (newitem == NULL)
6066 		    abort = TRUE;
6067 		else
6068 		{
6069 		    newitem->ht = &dd->dv_hashtab;
6070 		    newitem->prev = *ht_stack;
6071 		    *ht_stack = newitem;
6072 		}
6073 	    }
6074 	}
6075     }
6076     else if (tv->v_type == VAR_LIST)
6077     {
6078 	list_T	*ll = tv->vval.v_list;
6079 
6080 	if (ll != NULL && ll->lv_copyID != copyID)
6081 	{
6082 	    /* Didn't see this list yet. */
6083 	    ll->lv_copyID = copyID;
6084 	    if (list_stack == NULL)
6085 	    {
6086 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
6087 	    }
6088 	    else
6089 	    {
6090 		list_stack_T *newitem = (list_stack_T*)malloc(
6091 							sizeof(list_stack_T));
6092 		if (newitem == NULL)
6093 		    abort = TRUE;
6094 		else
6095 		{
6096 		    newitem->list = ll;
6097 		    newitem->prev = *list_stack;
6098 		    *list_stack = newitem;
6099 		}
6100 	    }
6101 	}
6102     }
6103     else if (tv->v_type == VAR_FUNC)
6104     {
6105 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
6106     }
6107     else if (tv->v_type == VAR_PARTIAL)
6108     {
6109 	partial_T	*pt = tv->vval.v_partial;
6110 	int		i;
6111 
6112 	/* A partial does not have a copyID, because it cannot contain itself.
6113 	 */
6114 	if (pt != NULL)
6115 	{
6116 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
6117 
6118 	    if (pt->pt_dict != NULL)
6119 	    {
6120 		typval_T dtv;
6121 
6122 		dtv.v_type = VAR_DICT;
6123 		dtv.vval.v_dict = pt->pt_dict;
6124 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
6125 	    }
6126 
6127 	    for (i = 0; i < pt->pt_argc; ++i)
6128 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
6129 							ht_stack, list_stack);
6130 	}
6131     }
6132 #ifdef FEAT_JOB_CHANNEL
6133     else if (tv->v_type == VAR_JOB)
6134     {
6135 	job_T	    *job = tv->vval.v_job;
6136 	typval_T    dtv;
6137 
6138 	if (job != NULL && job->jv_copyID != copyID)
6139 	{
6140 	    job->jv_copyID = copyID;
6141 	    if (job->jv_channel != NULL)
6142 	    {
6143 		dtv.v_type = VAR_CHANNEL;
6144 		dtv.vval.v_channel = job->jv_channel;
6145 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
6146 	    }
6147 	    if (job->jv_exit_cb.cb_partial != NULL)
6148 	    {
6149 		dtv.v_type = VAR_PARTIAL;
6150 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
6151 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
6152 	    }
6153 	}
6154     }
6155     else if (tv->v_type == VAR_CHANNEL)
6156     {
6157 	channel_T   *ch =tv->vval.v_channel;
6158 	ch_part_T   part;
6159 	typval_T    dtv;
6160 	jsonq_T	    *jq;
6161 	cbq_T	    *cq;
6162 
6163 	if (ch != NULL && ch->ch_copyID != copyID)
6164 	{
6165 	    ch->ch_copyID = copyID;
6166 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
6167 	    {
6168 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
6169 							     jq = jq->jq_next)
6170 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
6171 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
6172 							     cq = cq->cq_next)
6173 		    if (cq->cq_callback.cb_partial != NULL)
6174 		    {
6175 			dtv.v_type = VAR_PARTIAL;
6176 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
6177 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
6178 		    }
6179 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
6180 		{
6181 		    dtv.v_type = VAR_PARTIAL;
6182 		    dtv.vval.v_partial =
6183 				      ch->ch_part[part].ch_callback.cb_partial;
6184 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
6185 		}
6186 	    }
6187 	    if (ch->ch_callback.cb_partial != NULL)
6188 	    {
6189 		dtv.v_type = VAR_PARTIAL;
6190 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
6191 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
6192 	    }
6193 	    if (ch->ch_close_cb.cb_partial != NULL)
6194 	    {
6195 		dtv.v_type = VAR_PARTIAL;
6196 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
6197 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
6198 	    }
6199 	}
6200     }
6201 #endif
6202     return abort;
6203 }
6204 
6205     static char *
6206 get_var_special_name(int nr)
6207 {
6208     switch (nr)
6209     {
6210 	case VVAL_FALSE: return "v:false";
6211 	case VVAL_TRUE:  return "v:true";
6212 	case VVAL_NONE:  return "v:none";
6213 	case VVAL_NULL:  return "v:null";
6214     }
6215     internal_error("get_var_special_name()");
6216     return "42";
6217 }
6218 
6219 /*
6220  * Return a string with the string representation of a variable.
6221  * If the memory is allocated "tofree" is set to it, otherwise NULL.
6222  * "numbuf" is used for a number.
6223  * When "copyID" is not NULL replace recursive lists and dicts with "...".
6224  * When both "echo_style" and "composite_val" are FALSE, put quotes around
6225  * stings as "string()", otherwise does not put quotes around strings, as
6226  * ":echo" displays values.
6227  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
6228  * are replaced with "...".
6229  * May return NULL.
6230  */
6231     char_u *
6232 echo_string_core(
6233     typval_T	*tv,
6234     char_u	**tofree,
6235     char_u	*numbuf,
6236     int		copyID,
6237     int		echo_style,
6238     int		restore_copyID,
6239     int		composite_val)
6240 {
6241     static int	recurse = 0;
6242     char_u	*r = NULL;
6243 
6244     if (recurse >= DICT_MAXNEST)
6245     {
6246 	if (!did_echo_string_emsg)
6247 	{
6248 	    /* Only give this message once for a recursive call to avoid
6249 	     * flooding the user with errors.  And stop iterating over lists
6250 	     * and dicts. */
6251 	    did_echo_string_emsg = TRUE;
6252 	    emsg(_("E724: variable nested too deep for displaying"));
6253 	}
6254 	*tofree = NULL;
6255 	return (char_u *)"{E724}";
6256     }
6257     ++recurse;
6258 
6259     switch (tv->v_type)
6260     {
6261 	case VAR_STRING:
6262 	    if (echo_style && !composite_val)
6263 	    {
6264 		*tofree = NULL;
6265 		r = tv->vval.v_string;
6266 		if (r == NULL)
6267 		    r = (char_u *)"";
6268 	    }
6269 	    else
6270 	    {
6271 		*tofree = string_quote(tv->vval.v_string, FALSE);
6272 		r = *tofree;
6273 	    }
6274 	    break;
6275 
6276 	case VAR_FUNC:
6277 	    if (echo_style)
6278 	    {
6279 		*tofree = NULL;
6280 		r = tv->vval.v_string;
6281 	    }
6282 	    else
6283 	    {
6284 		*tofree = string_quote(tv->vval.v_string, TRUE);
6285 		r = *tofree;
6286 	    }
6287 	    break;
6288 
6289 	case VAR_PARTIAL:
6290 	    {
6291 		partial_T   *pt = tv->vval.v_partial;
6292 		char_u	    *fname = string_quote(pt == NULL ? NULL
6293 						    : partial_name(pt), FALSE);
6294 		garray_T    ga;
6295 		int	    i;
6296 		char_u	    *tf;
6297 
6298 		ga_init2(&ga, 1, 100);
6299 		ga_concat(&ga, (char_u *)"function(");
6300 		if (fname != NULL)
6301 		{
6302 		    ga_concat(&ga, fname);
6303 		    vim_free(fname);
6304 		}
6305 		if (pt != NULL && pt->pt_argc > 0)
6306 		{
6307 		    ga_concat(&ga, (char_u *)", [");
6308 		    for (i = 0; i < pt->pt_argc; ++i)
6309 		    {
6310 			if (i > 0)
6311 			    ga_concat(&ga, (char_u *)", ");
6312 			ga_concat(&ga,
6313 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
6314 			vim_free(tf);
6315 		    }
6316 		    ga_concat(&ga, (char_u *)"]");
6317 		}
6318 		if (pt != NULL && pt->pt_dict != NULL)
6319 		{
6320 		    typval_T dtv;
6321 
6322 		    ga_concat(&ga, (char_u *)", ");
6323 		    dtv.v_type = VAR_DICT;
6324 		    dtv.vval.v_dict = pt->pt_dict;
6325 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
6326 		    vim_free(tf);
6327 		}
6328 		ga_concat(&ga, (char_u *)")");
6329 
6330 		*tofree = ga.ga_data;
6331 		r = *tofree;
6332 		break;
6333 	    }
6334 
6335 	case VAR_BLOB:
6336 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
6337 	    break;
6338 
6339 	case VAR_LIST:
6340 	    if (tv->vval.v_list == NULL)
6341 	    {
6342 		*tofree = NULL;
6343 		r = NULL;
6344 	    }
6345 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
6346 		    && tv->vval.v_list->lv_len > 0)
6347 	    {
6348 		*tofree = NULL;
6349 		r = (char_u *)"[...]";
6350 	    }
6351 	    else
6352 	    {
6353 		int old_copyID = tv->vval.v_list->lv_copyID;
6354 
6355 		tv->vval.v_list->lv_copyID = copyID;
6356 		*tofree = list2string(tv, copyID, restore_copyID);
6357 		if (restore_copyID)
6358 		    tv->vval.v_list->lv_copyID = old_copyID;
6359 		r = *tofree;
6360 	    }
6361 	    break;
6362 
6363 	case VAR_DICT:
6364 	    if (tv->vval.v_dict == NULL)
6365 	    {
6366 		*tofree = NULL;
6367 		r = NULL;
6368 	    }
6369 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
6370 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
6371 	    {
6372 		*tofree = NULL;
6373 		r = (char_u *)"{...}";
6374 	    }
6375 	    else
6376 	    {
6377 		int old_copyID = tv->vval.v_dict->dv_copyID;
6378 		tv->vval.v_dict->dv_copyID = copyID;
6379 		*tofree = dict2string(tv, copyID, restore_copyID);
6380 		if (restore_copyID)
6381 		    tv->vval.v_dict->dv_copyID = old_copyID;
6382 		r = *tofree;
6383 	    }
6384 	    break;
6385 
6386 	case VAR_NUMBER:
6387 	case VAR_UNKNOWN:
6388 	    *tofree = NULL;
6389 	    r = tv_get_string_buf(tv, numbuf);
6390 	    break;
6391 
6392 	case VAR_JOB:
6393 	case VAR_CHANNEL:
6394 	    *tofree = NULL;
6395 	    r = tv_get_string_buf(tv, numbuf);
6396 	    if (composite_val)
6397 	    {
6398 		*tofree = string_quote(r, FALSE);
6399 		r = *tofree;
6400 	    }
6401 	    break;
6402 
6403 	case VAR_FLOAT:
6404 #ifdef FEAT_FLOAT
6405 	    *tofree = NULL;
6406 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
6407 	    r = numbuf;
6408 	    break;
6409 #endif
6410 
6411 	case VAR_SPECIAL:
6412 	    *tofree = NULL;
6413 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
6414 	    break;
6415     }
6416 
6417     if (--recurse == 0)
6418 	did_echo_string_emsg = FALSE;
6419     return r;
6420 }
6421 
6422 /*
6423  * Return a string with the string representation of a variable.
6424  * If the memory is allocated "tofree" is set to it, otherwise NULL.
6425  * "numbuf" is used for a number.
6426  * Does not put quotes around strings, as ":echo" displays values.
6427  * When "copyID" is not NULL replace recursive lists and dicts with "...".
6428  * May return NULL.
6429  */
6430     char_u *
6431 echo_string(
6432     typval_T	*tv,
6433     char_u	**tofree,
6434     char_u	*numbuf,
6435     int		copyID)
6436 {
6437     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
6438 }
6439 
6440 /*
6441  * Return a string with the string representation of a variable.
6442  * If the memory is allocated "tofree" is set to it, otherwise NULL.
6443  * "numbuf" is used for a number.
6444  * Puts quotes around strings, so that they can be parsed back by eval().
6445  * May return NULL.
6446  */
6447     char_u *
6448 tv2string(
6449     typval_T	*tv,
6450     char_u	**tofree,
6451     char_u	*numbuf,
6452     int		copyID)
6453 {
6454     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
6455 }
6456 
6457 /*
6458  * Return string "str" in ' quotes, doubling ' characters.
6459  * If "str" is NULL an empty string is assumed.
6460  * If "function" is TRUE make it function('string').
6461  */
6462     char_u *
6463 string_quote(char_u *str, int function)
6464 {
6465     unsigned	len;
6466     char_u	*p, *r, *s;
6467 
6468     len = (function ? 13 : 3);
6469     if (str != NULL)
6470     {
6471 	len += (unsigned)STRLEN(str);
6472 	for (p = str; *p != NUL; MB_PTR_ADV(p))
6473 	    if (*p == '\'')
6474 		++len;
6475     }
6476     s = r = alloc(len);
6477     if (r != NULL)
6478     {
6479 	if (function)
6480 	{
6481 	    STRCPY(r, "function('");
6482 	    r += 10;
6483 	}
6484 	else
6485 	    *r++ = '\'';
6486 	if (str != NULL)
6487 	    for (p = str; *p != NUL; )
6488 	    {
6489 		if (*p == '\'')
6490 		    *r++ = '\'';
6491 		MB_COPY_CHAR(p, r);
6492 	    }
6493 	*r++ = '\'';
6494 	if (function)
6495 	    *r++ = ')';
6496 	*r++ = NUL;
6497     }
6498     return s;
6499 }
6500 
6501 #if defined(FEAT_FLOAT) || defined(PROTO)
6502 /*
6503  * Convert the string "text" to a floating point number.
6504  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
6505  * this always uses a decimal point.
6506  * Returns the length of the text that was consumed.
6507  */
6508     int
6509 string2float(
6510     char_u	*text,
6511     float_T	*value)	    /* result stored here */
6512 {
6513     char	*s = (char *)text;
6514     float_T	f;
6515 
6516     /* MS-Windows does not deal with "inf" and "nan" properly. */
6517     if (STRNICMP(text, "inf", 3) == 0)
6518     {
6519 	*value = INFINITY;
6520 	return 3;
6521     }
6522     if (STRNICMP(text, "-inf", 3) == 0)
6523     {
6524 	*value = -INFINITY;
6525 	return 4;
6526     }
6527     if (STRNICMP(text, "nan", 3) == 0)
6528     {
6529 	*value = NAN;
6530 	return 3;
6531     }
6532     f = strtod(s, &s);
6533     *value = f;
6534     return (int)((char_u *)s - text);
6535 }
6536 #endif
6537 
6538 /*
6539  * Get the value of an environment variable.
6540  * "arg" is pointing to the '$'.  It is advanced to after the name.
6541  * If the environment variable was not set, silently assume it is empty.
6542  * Return FAIL if the name is invalid.
6543  */
6544     static int
6545 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
6546 {
6547     char_u	*string = NULL;
6548     int		len;
6549     int		cc;
6550     char_u	*name;
6551     int		mustfree = FALSE;
6552 
6553     ++*arg;
6554     name = *arg;
6555     len = get_env_len(arg);
6556     if (evaluate)
6557     {
6558 	if (len == 0)
6559 	    return FAIL; /* invalid empty name */
6560 
6561 	cc = name[len];
6562 	name[len] = NUL;
6563 	/* first try vim_getenv(), fast for normal environment vars */
6564 	string = vim_getenv(name, &mustfree);
6565 	if (string != NULL && *string != NUL)
6566 	{
6567 	    if (!mustfree)
6568 		string = vim_strsave(string);
6569 	}
6570 	else
6571 	{
6572 	    if (mustfree)
6573 		vim_free(string);
6574 
6575 	    /* next try expanding things like $VIM and ${HOME} */
6576 	    string = expand_env_save(name - 1);
6577 	    if (string != NULL && *string == '$')
6578 		VIM_CLEAR(string);
6579 	}
6580 	name[len] = cc;
6581 
6582 	rettv->v_type = VAR_STRING;
6583 	rettv->vval.v_string = string;
6584     }
6585 
6586     return OK;
6587 }
6588 
6589 
6590 
6591 /*
6592  * Translate a String variable into a position.
6593  * Returns NULL when there is an error.
6594  */
6595     pos_T *
6596 var2fpos(
6597     typval_T	*varp,
6598     int		dollar_lnum,	/* TRUE when $ is last line */
6599     int		*fnum)		/* set to fnum for '0, 'A, etc. */
6600 {
6601     char_u		*name;
6602     static pos_T	pos;
6603     pos_T		*pp;
6604 
6605     /* Argument can be [lnum, col, coladd]. */
6606     if (varp->v_type == VAR_LIST)
6607     {
6608 	list_T		*l;
6609 	int		len;
6610 	int		error = FALSE;
6611 	listitem_T	*li;
6612 
6613 	l = varp->vval.v_list;
6614 	if (l == NULL)
6615 	    return NULL;
6616 
6617 	/* Get the line number */
6618 	pos.lnum = list_find_nr(l, 0L, &error);
6619 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
6620 	    return NULL;	/* invalid line number */
6621 
6622 	/* Get the column number */
6623 	pos.col = list_find_nr(l, 1L, &error);
6624 	if (error)
6625 	    return NULL;
6626 	len = (long)STRLEN(ml_get(pos.lnum));
6627 
6628 	/* We accept "$" for the column number: last column. */
6629 	li = list_find(l, 1L);
6630 	if (li != NULL && li->li_tv.v_type == VAR_STRING
6631 		&& li->li_tv.vval.v_string != NULL
6632 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
6633 	    pos.col = len + 1;
6634 
6635 	/* Accept a position up to the NUL after the line. */
6636 	if (pos.col == 0 || (int)pos.col > len + 1)
6637 	    return NULL;	/* invalid column number */
6638 	--pos.col;
6639 
6640 	/* Get the virtual offset.  Defaults to zero. */
6641 	pos.coladd = list_find_nr(l, 2L, &error);
6642 	if (error)
6643 	    pos.coladd = 0;
6644 
6645 	return &pos;
6646     }
6647 
6648     name = tv_get_string_chk(varp);
6649     if (name == NULL)
6650 	return NULL;
6651     if (name[0] == '.')				/* cursor */
6652 	return &curwin->w_cursor;
6653     if (name[0] == 'v' && name[1] == NUL)	/* Visual start */
6654     {
6655 	if (VIsual_active)
6656 	    return &VIsual;
6657 	return &curwin->w_cursor;
6658     }
6659     if (name[0] == '\'')			/* mark */
6660     {
6661 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
6662 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
6663 	    return NULL;
6664 	return pp;
6665     }
6666 
6667     pos.coladd = 0;
6668 
6669     if (name[0] == 'w' && dollar_lnum)
6670     {
6671 	pos.col = 0;
6672 	if (name[1] == '0')		/* "w0": first visible line */
6673 	{
6674 	    update_topline();
6675 	    /* In silent Ex mode topline is zero, but that's not a valid line
6676 	     * number; use one instead. */
6677 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
6678 	    return &pos;
6679 	}
6680 	else if (name[1] == '$')	/* "w$": last visible line */
6681 	{
6682 	    validate_botline();
6683 	    /* In silent Ex mode botline is zero, return zero then. */
6684 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
6685 	    return &pos;
6686 	}
6687     }
6688     else if (name[0] == '$')		/* last column or line */
6689     {
6690 	if (dollar_lnum)
6691 	{
6692 	    pos.lnum = curbuf->b_ml.ml_line_count;
6693 	    pos.col = 0;
6694 	}
6695 	else
6696 	{
6697 	    pos.lnum = curwin->w_cursor.lnum;
6698 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
6699 	}
6700 	return &pos;
6701     }
6702     return NULL;
6703 }
6704 
6705 /*
6706  * Convert list in "arg" into a position and optional file number.
6707  * When "fnump" is NULL there is no file number, only 3 items.
6708  * Note that the column is passed on as-is, the caller may want to decrement
6709  * it to use 1 for the first column.
6710  * Return FAIL when conversion is not possible, doesn't check the position for
6711  * validity.
6712  */
6713     int
6714 list2fpos(
6715     typval_T	*arg,
6716     pos_T	*posp,
6717     int		*fnump,
6718     colnr_T	*curswantp)
6719 {
6720     list_T	*l = arg->vval.v_list;
6721     long	i = 0;
6722     long	n;
6723 
6724     /* List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
6725      * there when "fnump" isn't NULL; "coladd" and "curswant" are optional. */
6726     if (arg->v_type != VAR_LIST
6727 	    || l == NULL
6728 	    || l->lv_len < (fnump == NULL ? 2 : 3)
6729 	    || l->lv_len > (fnump == NULL ? 4 : 5))
6730 	return FAIL;
6731 
6732     if (fnump != NULL)
6733     {
6734 	n = list_find_nr(l, i++, NULL);	/* fnum */
6735 	if (n < 0)
6736 	    return FAIL;
6737 	if (n == 0)
6738 	    n = curbuf->b_fnum;		/* current buffer */
6739 	*fnump = n;
6740     }
6741 
6742     n = list_find_nr(l, i++, NULL);	/* lnum */
6743     if (n < 0)
6744 	return FAIL;
6745     posp->lnum = n;
6746 
6747     n = list_find_nr(l, i++, NULL);	/* col */
6748     if (n < 0)
6749 	return FAIL;
6750     posp->col = n;
6751 
6752     n = list_find_nr(l, i, NULL);	/* off */
6753     if (n < 0)
6754 	posp->coladd = 0;
6755     else
6756 	posp->coladd = n;
6757 
6758     if (curswantp != NULL)
6759 	*curswantp = list_find_nr(l, i + 1, NULL);  /* curswant */
6760 
6761     return OK;
6762 }
6763 
6764 /*
6765  * Get the length of an environment variable name.
6766  * Advance "arg" to the first character after the name.
6767  * Return 0 for error.
6768  */
6769     static int
6770 get_env_len(char_u **arg)
6771 {
6772     char_u	*p;
6773     int		len;
6774 
6775     for (p = *arg; vim_isIDc(*p); ++p)
6776 	;
6777     if (p == *arg)	    /* no name found */
6778 	return 0;
6779 
6780     len = (int)(p - *arg);
6781     *arg = p;
6782     return len;
6783 }
6784 
6785 /*
6786  * Get the length of the name of a function or internal variable.
6787  * "arg" is advanced to the first non-white character after the name.
6788  * Return 0 if something is wrong.
6789  */
6790     int
6791 get_id_len(char_u **arg)
6792 {
6793     char_u	*p;
6794     int		len;
6795 
6796     /* Find the end of the name. */
6797     for (p = *arg; eval_isnamec(*p); ++p)
6798     {
6799 	if (*p == ':')
6800 	{
6801 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6802 	     * slice "[n:]".  Also "xx:" is not a namespace. */
6803 	    len = (int)(p - *arg);
6804 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
6805 		    || len > 1)
6806 		break;
6807 	}
6808     }
6809     if (p == *arg)	    /* no name found */
6810 	return 0;
6811 
6812     len = (int)(p - *arg);
6813     *arg = skipwhite(p);
6814 
6815     return len;
6816 }
6817 
6818 /*
6819  * Get the length of the name of a variable or function.
6820  * Only the name is recognized, does not handle ".key" or "[idx]".
6821  * "arg" is advanced to the first non-white character after the name.
6822  * Return -1 if curly braces expansion failed.
6823  * Return 0 if something else is wrong.
6824  * If the name contains 'magic' {}'s, expand them and return the
6825  * expanded name in an allocated string via 'alias' - caller must free.
6826  */
6827     int
6828 get_name_len(
6829     char_u	**arg,
6830     char_u	**alias,
6831     int		evaluate,
6832     int		verbose)
6833 {
6834     int		len;
6835     char_u	*p;
6836     char_u	*expr_start;
6837     char_u	*expr_end;
6838 
6839     *alias = NULL;  /* default to no alias */
6840 
6841     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
6842 						  && (*arg)[2] == (int)KE_SNR)
6843     {
6844 	/* hard coded <SNR>, already translated */
6845 	*arg += 3;
6846 	return get_id_len(arg) + 3;
6847     }
6848     len = eval_fname_script(*arg);
6849     if (len > 0)
6850     {
6851 	/* literal "<SID>", "s:" or "<SNR>" */
6852 	*arg += len;
6853     }
6854 
6855     /*
6856      * Find the end of the name; check for {} construction.
6857      */
6858     p = find_name_end(*arg, &expr_start, &expr_end,
6859 					       len > 0 ? 0 : FNE_CHECK_START);
6860     if (expr_start != NULL)
6861     {
6862 	char_u	*temp_string;
6863 
6864 	if (!evaluate)
6865 	{
6866 	    len += (int)(p - *arg);
6867 	    *arg = skipwhite(p);
6868 	    return len;
6869 	}
6870 
6871 	/*
6872 	 * Include any <SID> etc in the expanded string:
6873 	 * Thus the -len here.
6874 	 */
6875 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
6876 	if (temp_string == NULL)
6877 	    return -1;
6878 	*alias = temp_string;
6879 	*arg = skipwhite(p);
6880 	return (int)STRLEN(temp_string);
6881     }
6882 
6883     len += get_id_len(arg);
6884     // Only give an error when there is something, otherwise it will be
6885     // reported at a higher level.
6886     if (len == 0 && verbose && **arg != NUL)
6887 	semsg(_(e_invexpr2), *arg);
6888 
6889     return len;
6890 }
6891 
6892 /*
6893  * Find the end of a variable or function name, taking care of magic braces.
6894  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
6895  * start and end of the first magic braces item.
6896  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
6897  * Return a pointer to just after the name.  Equal to "arg" if there is no
6898  * valid name.
6899  */
6900     char_u *
6901 find_name_end(
6902     char_u	*arg,
6903     char_u	**expr_start,
6904     char_u	**expr_end,
6905     int		flags)
6906 {
6907     int		mb_nest = 0;
6908     int		br_nest = 0;
6909     char_u	*p;
6910     int		len;
6911 
6912     if (expr_start != NULL)
6913     {
6914 	*expr_start = NULL;
6915 	*expr_end = NULL;
6916     }
6917 
6918     /* Quick check for valid starting character. */
6919     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg) && *arg != '{')
6920 	return arg;
6921 
6922     for (p = arg; *p != NUL
6923 		    && (eval_isnamec(*p)
6924 			|| *p == '{'
6925 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
6926 			|| mb_nest != 0
6927 			|| br_nest != 0); MB_PTR_ADV(p))
6928     {
6929 	if (*p == '\'')
6930 	{
6931 	    /* skip over 'string' to avoid counting [ and ] inside it. */
6932 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
6933 		;
6934 	    if (*p == NUL)
6935 		break;
6936 	}
6937 	else if (*p == '"')
6938 	{
6939 	    /* skip over "str\"ing" to avoid counting [ and ] inside it. */
6940 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
6941 		if (*p == '\\' && p[1] != NUL)
6942 		    ++p;
6943 	    if (*p == NUL)
6944 		break;
6945 	}
6946 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
6947 	{
6948 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6949 	     * slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is. */
6950 	    len = (int)(p - arg);
6951 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
6952 		    || (len > 1 && p[-1] != '}'))
6953 		break;
6954 	}
6955 
6956 	if (mb_nest == 0)
6957 	{
6958 	    if (*p == '[')
6959 		++br_nest;
6960 	    else if (*p == ']')
6961 		--br_nest;
6962 	}
6963 
6964 	if (br_nest == 0)
6965 	{
6966 	    if (*p == '{')
6967 	    {
6968 		mb_nest++;
6969 		if (expr_start != NULL && *expr_start == NULL)
6970 		    *expr_start = p;
6971 	    }
6972 	    else if (*p == '}')
6973 	    {
6974 		mb_nest--;
6975 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
6976 		    *expr_end = p;
6977 	    }
6978 	}
6979     }
6980 
6981     return p;
6982 }
6983 
6984 /*
6985  * Expands out the 'magic' {}'s in a variable/function name.
6986  * Note that this can call itself recursively, to deal with
6987  * constructs like foo{bar}{baz}{bam}
6988  * The four pointer arguments point to "foo{expre}ss{ion}bar"
6989  *			"in_start"      ^
6990  *			"expr_start"	   ^
6991  *			"expr_end"		 ^
6992  *			"in_end"			    ^
6993  *
6994  * Returns a new allocated string, which the caller must free.
6995  * Returns NULL for failure.
6996  */
6997     static char_u *
6998 make_expanded_name(
6999     char_u	*in_start,
7000     char_u	*expr_start,
7001     char_u	*expr_end,
7002     char_u	*in_end)
7003 {
7004     char_u	c1;
7005     char_u	*retval = NULL;
7006     char_u	*temp_result;
7007     char_u	*nextcmd = NULL;
7008 
7009     if (expr_end == NULL || in_end == NULL)
7010 	return NULL;
7011     *expr_start	= NUL;
7012     *expr_end = NUL;
7013     c1 = *in_end;
7014     *in_end = NUL;
7015 
7016     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
7017     if (temp_result != NULL && nextcmd == NULL)
7018     {
7019 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
7020 						   + (in_end - expr_end) + 1);
7021 	if (retval != NULL)
7022 	{
7023 	    STRCPY(retval, in_start);
7024 	    STRCAT(retval, temp_result);
7025 	    STRCAT(retval, expr_end + 1);
7026 	}
7027     }
7028     vim_free(temp_result);
7029 
7030     *in_end = c1;		/* put char back for error messages */
7031     *expr_start = '{';
7032     *expr_end = '}';
7033 
7034     if (retval != NULL)
7035     {
7036 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
7037 	if (expr_start != NULL)
7038 	{
7039 	    /* Further expansion! */
7040 	    temp_result = make_expanded_name(retval, expr_start,
7041 						       expr_end, temp_result);
7042 	    vim_free(retval);
7043 	    retval = temp_result;
7044 	}
7045     }
7046 
7047     return retval;
7048 }
7049 
7050 /*
7051  * Return TRUE if character "c" can be used in a variable or function name.
7052  * Does not include '{' or '}' for magic braces.
7053  */
7054     int
7055 eval_isnamec(int c)
7056 {
7057     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
7058 }
7059 
7060 /*
7061  * Return TRUE if character "c" can be used as the first character in a
7062  * variable or function name (excluding '{' and '}').
7063  */
7064     int
7065 eval_isnamec1(int c)
7066 {
7067     return (ASCII_ISALPHA(c) || c == '_');
7068 }
7069 
7070 /*
7071  * Set number v: variable to "val".
7072  */
7073     void
7074 set_vim_var_nr(int idx, varnumber_T val)
7075 {
7076     vimvars[idx].vv_nr = val;
7077 }
7078 
7079 /*
7080  * Get typval_T v: variable value.
7081  */
7082     typval_T *
7083 get_vim_var_tv(int idx)
7084 {
7085     return &vimvars[idx].vv_tv;
7086 }
7087 
7088 /*
7089  * Get number v: variable value.
7090  */
7091     varnumber_T
7092 get_vim_var_nr(int idx)
7093 {
7094     return vimvars[idx].vv_nr;
7095 }
7096 
7097 /*
7098  * Get string v: variable value.  Uses a static buffer, can only be used once.
7099  * If the String variable has never been set, return an empty string.
7100  * Never returns NULL;
7101  */
7102     char_u *
7103 get_vim_var_str(int idx)
7104 {
7105     return tv_get_string(&vimvars[idx].vv_tv);
7106 }
7107 
7108 /*
7109  * Get List v: variable value.  Caller must take care of reference count when
7110  * needed.
7111  */
7112     list_T *
7113 get_vim_var_list(int idx)
7114 {
7115     return vimvars[idx].vv_list;
7116 }
7117 
7118 /*
7119  * Get Dict v: variable value.  Caller must take care of reference count when
7120  * needed.
7121  */
7122     dict_T *
7123 get_vim_var_dict(int idx)
7124 {
7125     return vimvars[idx].vv_dict;
7126 }
7127 
7128 /*
7129  * Set v:char to character "c".
7130  */
7131     void
7132 set_vim_var_char(int c)
7133 {
7134     char_u	buf[MB_MAXBYTES + 1];
7135 
7136     if (has_mbyte)
7137 	buf[(*mb_char2bytes)(c, buf)] = NUL;
7138     else
7139     {
7140 	buf[0] = c;
7141 	buf[1] = NUL;
7142     }
7143     set_vim_var_string(VV_CHAR, buf, -1);
7144 }
7145 
7146 /*
7147  * Set v:count to "count" and v:count1 to "count1".
7148  * When "set_prevcount" is TRUE first set v:prevcount from v:count.
7149  */
7150     void
7151 set_vcount(
7152     long	count,
7153     long	count1,
7154     int		set_prevcount)
7155 {
7156     if (set_prevcount)
7157 	vimvars[VV_PREVCOUNT].vv_nr = vimvars[VV_COUNT].vv_nr;
7158     vimvars[VV_COUNT].vv_nr = count;
7159     vimvars[VV_COUNT1].vv_nr = count1;
7160 }
7161 
7162 /*
7163  * Save variables that might be changed as a side effect.  Used when executing
7164  * a timer callback.
7165  */
7166     void
7167 save_vimvars(vimvars_save_T *vvsave)
7168 {
7169     vvsave->vv_prevcount = vimvars[VV_PREVCOUNT].vv_nr;
7170     vvsave->vv_count = vimvars[VV_COUNT].vv_nr;
7171     vvsave->vv_count1 = vimvars[VV_COUNT1].vv_nr;
7172 }
7173 
7174 /*
7175  * Restore variables saved by save_vimvars().
7176  */
7177     void
7178 restore_vimvars(vimvars_save_T *vvsave)
7179 {
7180     vimvars[VV_PREVCOUNT].vv_nr = vvsave->vv_prevcount;
7181     vimvars[VV_COUNT].vv_nr = vvsave->vv_count;
7182     vimvars[VV_COUNT1].vv_nr = vvsave->vv_count1;
7183 }
7184 
7185 /*
7186  * Set string v: variable to a copy of "val".
7187  */
7188     void
7189 set_vim_var_string(
7190     int		idx,
7191     char_u	*val,
7192     int		len)	    /* length of "val" to use or -1 (whole string) */
7193 {
7194     clear_tv(&vimvars[idx].vv_di.di_tv);
7195     vimvars[idx].vv_type = VAR_STRING;
7196     if (val == NULL)
7197 	vimvars[idx].vv_str = NULL;
7198     else if (len == -1)
7199 	vimvars[idx].vv_str = vim_strsave(val);
7200     else
7201 	vimvars[idx].vv_str = vim_strnsave(val, len);
7202 }
7203 
7204 /*
7205  * Set List v: variable to "val".
7206  */
7207     void
7208 set_vim_var_list(int idx, list_T *val)
7209 {
7210     clear_tv(&vimvars[idx].vv_di.di_tv);
7211     vimvars[idx].vv_type = VAR_LIST;
7212     vimvars[idx].vv_list = val;
7213     if (val != NULL)
7214 	++val->lv_refcount;
7215 }
7216 
7217 /*
7218  * Set Dictionary v: variable to "val".
7219  */
7220     void
7221 set_vim_var_dict(int idx, dict_T *val)
7222 {
7223     clear_tv(&vimvars[idx].vv_di.di_tv);
7224     vimvars[idx].vv_type = VAR_DICT;
7225     vimvars[idx].vv_dict = val;
7226     if (val != NULL)
7227     {
7228 	++val->dv_refcount;
7229 	dict_set_items_ro(val);
7230     }
7231 }
7232 
7233 /*
7234  * Set v:register if needed.
7235  */
7236     void
7237 set_reg_var(int c)
7238 {
7239     char_u	regname;
7240 
7241     if (c == 0 || c == ' ')
7242 	regname = '"';
7243     else
7244 	regname = c;
7245     /* Avoid free/alloc when the value is already right. */
7246     if (vimvars[VV_REG].vv_str == NULL || vimvars[VV_REG].vv_str[0] != c)
7247 	set_vim_var_string(VV_REG, &regname, 1);
7248 }
7249 
7250 /*
7251  * Get or set v:exception.  If "oldval" == NULL, return the current value.
7252  * Otherwise, restore the value to "oldval" and return NULL.
7253  * Must always be called in pairs to save and restore v:exception!  Does not
7254  * take care of memory allocations.
7255  */
7256     char_u *
7257 v_exception(char_u *oldval)
7258 {
7259     if (oldval == NULL)
7260 	return vimvars[VV_EXCEPTION].vv_str;
7261 
7262     vimvars[VV_EXCEPTION].vv_str = oldval;
7263     return NULL;
7264 }
7265 
7266 /*
7267  * Get or set v:throwpoint.  If "oldval" == NULL, return the current value.
7268  * Otherwise, restore the value to "oldval" and return NULL.
7269  * Must always be called in pairs to save and restore v:throwpoint!  Does not
7270  * take care of memory allocations.
7271  */
7272     char_u *
7273 v_throwpoint(char_u *oldval)
7274 {
7275     if (oldval == NULL)
7276 	return vimvars[VV_THROWPOINT].vv_str;
7277 
7278     vimvars[VV_THROWPOINT].vv_str = oldval;
7279     return NULL;
7280 }
7281 
7282 /*
7283  * Set v:cmdarg.
7284  * If "eap" != NULL, use "eap" to generate the value and return the old value.
7285  * If "oldarg" != NULL, restore the value to "oldarg" and return NULL.
7286  * Must always be called in pairs!
7287  */
7288     char_u *
7289 set_cmdarg(exarg_T *eap, char_u *oldarg)
7290 {
7291     char_u	*oldval;
7292     char_u	*newval;
7293     unsigned	len;
7294 
7295     oldval = vimvars[VV_CMDARG].vv_str;
7296     if (eap == NULL)
7297     {
7298 	vim_free(oldval);
7299 	vimvars[VV_CMDARG].vv_str = oldarg;
7300 	return NULL;
7301     }
7302 
7303     if (eap->force_bin == FORCE_BIN)
7304 	len = 6;
7305     else if (eap->force_bin == FORCE_NOBIN)
7306 	len = 8;
7307     else
7308 	len = 0;
7309 
7310     if (eap->read_edit)
7311 	len += 7;
7312 
7313     if (eap->force_ff != 0)
7314 	len += 10; /* " ++ff=unix" */
7315     if (eap->force_enc != 0)
7316 	len += (unsigned)STRLEN(eap->cmd + eap->force_enc) + 7;
7317     if (eap->bad_char != 0)
7318 	len += 7 + 4;  /* " ++bad=" + "keep" or "drop" */
7319 
7320     newval = alloc(len + 1);
7321     if (newval == NULL)
7322 	return NULL;
7323 
7324     if (eap->force_bin == FORCE_BIN)
7325 	sprintf((char *)newval, " ++bin");
7326     else if (eap->force_bin == FORCE_NOBIN)
7327 	sprintf((char *)newval, " ++nobin");
7328     else
7329 	*newval = NUL;
7330 
7331     if (eap->read_edit)
7332 	STRCAT(newval, " ++edit");
7333 
7334     if (eap->force_ff != 0)
7335 	sprintf((char *)newval + STRLEN(newval), " ++ff=%s",
7336 						eap->force_ff == 'u' ? "unix"
7337 						: eap->force_ff == 'd' ? "dos"
7338 						: "mac");
7339     if (eap->force_enc != 0)
7340 	sprintf((char *)newval + STRLEN(newval), " ++enc=%s",
7341 					       eap->cmd + eap->force_enc);
7342     if (eap->bad_char == BAD_KEEP)
7343 	STRCPY(newval + STRLEN(newval), " ++bad=keep");
7344     else if (eap->bad_char == BAD_DROP)
7345 	STRCPY(newval + STRLEN(newval), " ++bad=drop");
7346     else if (eap->bad_char != 0)
7347 	sprintf((char *)newval + STRLEN(newval), " ++bad=%c", eap->bad_char);
7348     vimvars[VV_CMDARG].vv_str = newval;
7349     return oldval;
7350 }
7351 
7352 /*
7353  * Get the value of internal variable "name".
7354  * Return OK or FAIL.  If OK is returned "rettv" must be cleared.
7355  */
7356     int
7357 get_var_tv(
7358     char_u	*name,
7359     int		len,		/* length of "name" */
7360     typval_T	*rettv,		/* NULL when only checking existence */
7361     dictitem_T	**dip,		/* non-NULL when typval's dict item is needed */
7362     int		verbose,	/* may give error message */
7363     int		no_autoload)	/* do not use script autoloading */
7364 {
7365     int		ret = OK;
7366     typval_T	*tv = NULL;
7367     dictitem_T	*v;
7368     int		cc;
7369 
7370     /* truncate the name, so that we can use strcmp() */
7371     cc = name[len];
7372     name[len] = NUL;
7373 
7374     /*
7375      * Check for user-defined variables.
7376      */
7377     v = find_var(name, NULL, no_autoload);
7378     if (v != NULL)
7379     {
7380 	tv = &v->di_tv;
7381 	if (dip != NULL)
7382 	    *dip = v;
7383     }
7384 
7385     if (tv == NULL)
7386     {
7387 	if (rettv != NULL && verbose)
7388 	    semsg(_(e_undefvar), name);
7389 	ret = FAIL;
7390     }
7391     else if (rettv != NULL)
7392 	copy_tv(tv, rettv);
7393 
7394     name[len] = cc;
7395 
7396     return ret;
7397 }
7398 
7399 /*
7400  * Check if variable "name[len]" is a local variable or an argument.
7401  * If so, "*eval_lavars_used" is set to TRUE.
7402  */
7403     static void
7404 check_vars(char_u *name, int len)
7405 {
7406     int		cc;
7407     char_u	*varname;
7408     hashtab_T	*ht;
7409 
7410     if (eval_lavars_used == NULL)
7411 	return;
7412 
7413     /* truncate the name, so that we can use strcmp() */
7414     cc = name[len];
7415     name[len] = NUL;
7416 
7417     ht = find_var_ht(name, &varname);
7418     if (ht == get_funccal_local_ht() || ht == get_funccal_args_ht())
7419     {
7420 	if (find_var(name, NULL, TRUE) != NULL)
7421 	    *eval_lavars_used = TRUE;
7422     }
7423 
7424     name[len] = cc;
7425 }
7426 
7427 /*
7428  * Handle:
7429  * - expr[expr], expr[expr:expr] subscript
7430  * - ".name" lookup
7431  * - function call with Funcref variable: func(expr)
7432  * - method call: var->method()
7433  *
7434  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
7435  */
7436     int
7437 handle_subscript(
7438     char_u	**arg,
7439     typval_T	*rettv,
7440     int		evaluate,	/* do more than finding the end */
7441     int		verbose)	/* give error messages */
7442 {
7443     int		ret = OK;
7444     dict_T	*selfdict = NULL;
7445     char_u	*s;
7446     typval_T	functv;
7447 
7448     // "." is ".name" lookup when we found a dict or when evaluating and
7449     // scriptversion is at least 2, where string concatenation is "..".
7450     while (ret == OK
7451 	    && (((**arg == '['
7452 		    || (**arg == '.' && (rettv->v_type == VAR_DICT
7453 			|| (!evaluate
7454 			    && (*arg)[1] != '.'
7455 			    && current_sctx.sc_version >= 2)))
7456 		    || (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
7457 					    || rettv->v_type == VAR_PARTIAL)))
7458 		&& !VIM_ISWHITE(*(*arg - 1)))
7459 	    || (**arg == '-' && (*arg)[1] == '>')))
7460     {
7461 	if (**arg == '(')
7462 	{
7463 	    partial_T	*pt = NULL;
7464 	    funcexe_T	funcexe;
7465 
7466 	    /* need to copy the funcref so that we can clear rettv */
7467 	    if (evaluate)
7468 	    {
7469 		functv = *rettv;
7470 		rettv->v_type = VAR_UNKNOWN;
7471 
7472 		/* Invoke the function.  Recursive! */
7473 		if (functv.v_type == VAR_PARTIAL)
7474 		{
7475 		    pt = functv.vval.v_partial;
7476 		    s = partial_name(pt);
7477 		}
7478 		else
7479 		    s = functv.vval.v_string;
7480 	    }
7481 	    else
7482 		s = (char_u *)"";
7483 
7484 	    vim_memset(&funcexe, 0, sizeof(funcexe));
7485 	    funcexe.firstline = curwin->w_cursor.lnum;
7486 	    funcexe.lastline = curwin->w_cursor.lnum;
7487 	    funcexe.evaluate = evaluate;
7488 	    funcexe.partial = pt;
7489 	    funcexe.selfdict = selfdict;
7490 	    ret = get_func_tv(s, -1, rettv, arg, &funcexe);
7491 
7492 	    /* Clear the funcref afterwards, so that deleting it while
7493 	     * evaluating the arguments is possible (see test55). */
7494 	    if (evaluate)
7495 		clear_tv(&functv);
7496 
7497 	    /* Stop the expression evaluation when immediately aborting on
7498 	     * error, or when an interrupt occurred or an exception was thrown
7499 	     * but not caught. */
7500 	    if (aborting())
7501 	    {
7502 		if (ret == OK)
7503 		    clear_tv(rettv);
7504 		ret = FAIL;
7505 	    }
7506 	    dict_unref(selfdict);
7507 	    selfdict = NULL;
7508 	}
7509 	else if (**arg == '-')
7510 	{
7511 	    if (eval_method(arg, rettv, evaluate, verbose) == FAIL)
7512 	    {
7513 		clear_tv(rettv);
7514 		ret = FAIL;
7515 	    }
7516 	}
7517 	else /* **arg == '[' || **arg == '.' */
7518 	{
7519 	    dict_unref(selfdict);
7520 	    if (rettv->v_type == VAR_DICT)
7521 	    {
7522 		selfdict = rettv->vval.v_dict;
7523 		if (selfdict != NULL)
7524 		    ++selfdict->dv_refcount;
7525 	    }
7526 	    else
7527 		selfdict = NULL;
7528 	    if (eval_index(arg, rettv, evaluate, verbose) == FAIL)
7529 	    {
7530 		clear_tv(rettv);
7531 		ret = FAIL;
7532 	    }
7533 	}
7534     }
7535 
7536     /* Turn "dict.Func" into a partial for "Func" bound to "dict".
7537      * Don't do this when "Func" is already a partial that was bound
7538      * explicitly (pt_auto is FALSE). */
7539     if (selfdict != NULL
7540 	    && (rettv->v_type == VAR_FUNC
7541 		|| (rettv->v_type == VAR_PARTIAL
7542 		    && (rettv->vval.v_partial->pt_auto
7543 			|| rettv->vval.v_partial->pt_dict == NULL))))
7544 	selfdict = make_partial(selfdict, rettv);
7545 
7546     dict_unref(selfdict);
7547     return ret;
7548 }
7549 
7550 /*
7551  * Allocate memory for a variable type-value, and make it empty (0 or NULL
7552  * value).
7553  */
7554     typval_T *
7555 alloc_tv(void)
7556 {
7557     return ALLOC_CLEAR_ONE(typval_T);
7558 }
7559 
7560 /*
7561  * Allocate memory for a variable type-value, and assign a string to it.
7562  * The string "s" must have been allocated, it is consumed.
7563  * Return NULL for out of memory, the variable otherwise.
7564  */
7565     static typval_T *
7566 alloc_string_tv(char_u *s)
7567 {
7568     typval_T	*rettv;
7569 
7570     rettv = alloc_tv();
7571     if (rettv != NULL)
7572     {
7573 	rettv->v_type = VAR_STRING;
7574 	rettv->vval.v_string = s;
7575     }
7576     else
7577 	vim_free(s);
7578     return rettv;
7579 }
7580 
7581 /*
7582  * Free the memory for a variable type-value.
7583  */
7584     void
7585 free_tv(typval_T *varp)
7586 {
7587     if (varp != NULL)
7588     {
7589 	switch (varp->v_type)
7590 	{
7591 	    case VAR_FUNC:
7592 		func_unref(varp->vval.v_string);
7593 		/* FALLTHROUGH */
7594 	    case VAR_STRING:
7595 		vim_free(varp->vval.v_string);
7596 		break;
7597 	    case VAR_PARTIAL:
7598 		partial_unref(varp->vval.v_partial);
7599 		break;
7600 	    case VAR_BLOB:
7601 		blob_unref(varp->vval.v_blob);
7602 		break;
7603 	    case VAR_LIST:
7604 		list_unref(varp->vval.v_list);
7605 		break;
7606 	    case VAR_DICT:
7607 		dict_unref(varp->vval.v_dict);
7608 		break;
7609 	    case VAR_JOB:
7610 #ifdef FEAT_JOB_CHANNEL
7611 		job_unref(varp->vval.v_job);
7612 		break;
7613 #endif
7614 	    case VAR_CHANNEL:
7615 #ifdef FEAT_JOB_CHANNEL
7616 		channel_unref(varp->vval.v_channel);
7617 		break;
7618 #endif
7619 	    case VAR_NUMBER:
7620 	    case VAR_FLOAT:
7621 	    case VAR_UNKNOWN:
7622 	    case VAR_SPECIAL:
7623 		break;
7624 	}
7625 	vim_free(varp);
7626     }
7627 }
7628 
7629 /*
7630  * Free the memory for a variable value and set the value to NULL or 0.
7631  */
7632     void
7633 clear_tv(typval_T *varp)
7634 {
7635     if (varp != NULL)
7636     {
7637 	switch (varp->v_type)
7638 	{
7639 	    case VAR_FUNC:
7640 		func_unref(varp->vval.v_string);
7641 		/* FALLTHROUGH */
7642 	    case VAR_STRING:
7643 		VIM_CLEAR(varp->vval.v_string);
7644 		break;
7645 	    case VAR_PARTIAL:
7646 		partial_unref(varp->vval.v_partial);
7647 		varp->vval.v_partial = NULL;
7648 		break;
7649 	    case VAR_BLOB:
7650 		blob_unref(varp->vval.v_blob);
7651 		varp->vval.v_blob = NULL;
7652 		break;
7653 	    case VAR_LIST:
7654 		list_unref(varp->vval.v_list);
7655 		varp->vval.v_list = NULL;
7656 		break;
7657 	    case VAR_DICT:
7658 		dict_unref(varp->vval.v_dict);
7659 		varp->vval.v_dict = NULL;
7660 		break;
7661 	    case VAR_NUMBER:
7662 	    case VAR_SPECIAL:
7663 		varp->vval.v_number = 0;
7664 		break;
7665 	    case VAR_FLOAT:
7666 #ifdef FEAT_FLOAT
7667 		varp->vval.v_float = 0.0;
7668 		break;
7669 #endif
7670 	    case VAR_JOB:
7671 #ifdef FEAT_JOB_CHANNEL
7672 		job_unref(varp->vval.v_job);
7673 		varp->vval.v_job = NULL;
7674 #endif
7675 		break;
7676 	    case VAR_CHANNEL:
7677 #ifdef FEAT_JOB_CHANNEL
7678 		channel_unref(varp->vval.v_channel);
7679 		varp->vval.v_channel = NULL;
7680 #endif
7681 	    case VAR_UNKNOWN:
7682 		break;
7683 	}
7684 	varp->v_lock = 0;
7685     }
7686 }
7687 
7688 /*
7689  * Set the value of a variable to NULL without freeing items.
7690  */
7691     void
7692 init_tv(typval_T *varp)
7693 {
7694     if (varp != NULL)
7695 	vim_memset(varp, 0, sizeof(typval_T));
7696 }
7697 
7698 /*
7699  * Get the number value of a variable.
7700  * If it is a String variable, uses vim_str2nr().
7701  * For incompatible types, return 0.
7702  * tv_get_number_chk() is similar to tv_get_number(), but informs the
7703  * caller of incompatible types: it sets *denote to TRUE if "denote"
7704  * is not NULL or returns -1 otherwise.
7705  */
7706     varnumber_T
7707 tv_get_number(typval_T *varp)
7708 {
7709     int		error = FALSE;
7710 
7711     return tv_get_number_chk(varp, &error);	/* return 0L on error */
7712 }
7713 
7714     varnumber_T
7715 tv_get_number_chk(typval_T *varp, int *denote)
7716 {
7717     varnumber_T	n = 0L;
7718 
7719     switch (varp->v_type)
7720     {
7721 	case VAR_NUMBER:
7722 	    return varp->vval.v_number;
7723 	case VAR_FLOAT:
7724 #ifdef FEAT_FLOAT
7725 	    emsg(_("E805: Using a Float as a Number"));
7726 	    break;
7727 #endif
7728 	case VAR_FUNC:
7729 	case VAR_PARTIAL:
7730 	    emsg(_("E703: Using a Funcref as a Number"));
7731 	    break;
7732 	case VAR_STRING:
7733 	    if (varp->vval.v_string != NULL)
7734 		vim_str2nr(varp->vval.v_string, NULL, NULL,
7735 					    STR2NR_ALL, &n, NULL, 0, FALSE);
7736 	    return n;
7737 	case VAR_LIST:
7738 	    emsg(_("E745: Using a List as a Number"));
7739 	    break;
7740 	case VAR_DICT:
7741 	    emsg(_("E728: Using a Dictionary as a Number"));
7742 	    break;
7743 	case VAR_SPECIAL:
7744 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
7745 	    break;
7746 	case VAR_JOB:
7747 #ifdef FEAT_JOB_CHANNEL
7748 	    emsg(_("E910: Using a Job as a Number"));
7749 	    break;
7750 #endif
7751 	case VAR_CHANNEL:
7752 #ifdef FEAT_JOB_CHANNEL
7753 	    emsg(_("E913: Using a Channel as a Number"));
7754 	    break;
7755 #endif
7756 	case VAR_BLOB:
7757 	    emsg(_("E974: Using a Blob as a Number"));
7758 	    break;
7759 	case VAR_UNKNOWN:
7760 	    internal_error("tv_get_number(UNKNOWN)");
7761 	    break;
7762     }
7763     if (denote == NULL)		/* useful for values that must be unsigned */
7764 	n = -1;
7765     else
7766 	*denote = TRUE;
7767     return n;
7768 }
7769 
7770 #ifdef FEAT_FLOAT
7771     float_T
7772 tv_get_float(typval_T *varp)
7773 {
7774     switch (varp->v_type)
7775     {
7776 	case VAR_NUMBER:
7777 	    return (float_T)(varp->vval.v_number);
7778 	case VAR_FLOAT:
7779 	    return varp->vval.v_float;
7780 	case VAR_FUNC:
7781 	case VAR_PARTIAL:
7782 	    emsg(_("E891: Using a Funcref as a Float"));
7783 	    break;
7784 	case VAR_STRING:
7785 	    emsg(_("E892: Using a String as a Float"));
7786 	    break;
7787 	case VAR_LIST:
7788 	    emsg(_("E893: Using a List as a Float"));
7789 	    break;
7790 	case VAR_DICT:
7791 	    emsg(_("E894: Using a Dictionary as a Float"));
7792 	    break;
7793 	case VAR_SPECIAL:
7794 	    emsg(_("E907: Using a special value as a Float"));
7795 	    break;
7796 	case VAR_JOB:
7797 # ifdef FEAT_JOB_CHANNEL
7798 	    emsg(_("E911: Using a Job as a Float"));
7799 	    break;
7800 # endif
7801 	case VAR_CHANNEL:
7802 # ifdef FEAT_JOB_CHANNEL
7803 	    emsg(_("E914: Using a Channel as a Float"));
7804 	    break;
7805 # endif
7806 	case VAR_BLOB:
7807 	    emsg(_("E975: Using a Blob as a Float"));
7808 	    break;
7809 	case VAR_UNKNOWN:
7810 	    internal_error("tv_get_float(UNKNOWN)");
7811 	    break;
7812     }
7813     return 0;
7814 }
7815 #endif
7816 
7817 /*
7818  * Get the string value of a variable.
7819  * If it is a Number variable, the number is converted into a string.
7820  * tv_get_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7821  * tv_get_string_buf() uses a given buffer.
7822  * If the String variable has never been set, return an empty string.
7823  * Never returns NULL;
7824  * tv_get_string_chk() and tv_get_string_buf_chk() are similar, but return
7825  * NULL on error.
7826  */
7827     char_u *
7828 tv_get_string(typval_T *varp)
7829 {
7830     static char_u   mybuf[NUMBUFLEN];
7831 
7832     return tv_get_string_buf(varp, mybuf);
7833 }
7834 
7835     char_u *
7836 tv_get_string_buf(typval_T *varp, char_u *buf)
7837 {
7838     char_u	*res =  tv_get_string_buf_chk(varp, buf);
7839 
7840     return res != NULL ? res : (char_u *)"";
7841 }
7842 
7843 /*
7844  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7845  */
7846     char_u *
7847 tv_get_string_chk(typval_T *varp)
7848 {
7849     static char_u   mybuf[NUMBUFLEN];
7850 
7851     return tv_get_string_buf_chk(varp, mybuf);
7852 }
7853 
7854     char_u *
7855 tv_get_string_buf_chk(typval_T *varp, char_u *buf)
7856 {
7857     switch (varp->v_type)
7858     {
7859 	case VAR_NUMBER:
7860 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
7861 					    (long_long_T)varp->vval.v_number);
7862 	    return buf;
7863 	case VAR_FUNC:
7864 	case VAR_PARTIAL:
7865 	    emsg(_("E729: using Funcref as a String"));
7866 	    break;
7867 	case VAR_LIST:
7868 	    emsg(_("E730: using List as a String"));
7869 	    break;
7870 	case VAR_DICT:
7871 	    emsg(_("E731: using Dictionary as a String"));
7872 	    break;
7873 	case VAR_FLOAT:
7874 #ifdef FEAT_FLOAT
7875 	    emsg(_(e_float_as_string));
7876 	    break;
7877 #endif
7878 	case VAR_STRING:
7879 	    if (varp->vval.v_string != NULL)
7880 		return varp->vval.v_string;
7881 	    return (char_u *)"";
7882 	case VAR_SPECIAL:
7883 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
7884 	    return buf;
7885         case VAR_BLOB:
7886 	    emsg(_("E976: using Blob as a String"));
7887 	    break;
7888 	case VAR_JOB:
7889 #ifdef FEAT_JOB_CHANNEL
7890 	    {
7891 		job_T *job = varp->vval.v_job;
7892 		char  *status;
7893 
7894 		if (job == NULL)
7895 		    return (char_u *)"no process";
7896 		status = job->jv_status == JOB_FAILED ? "fail"
7897 				: job->jv_status >= JOB_ENDED ? "dead"
7898 				: "run";
7899 # ifdef UNIX
7900 		vim_snprintf((char *)buf, NUMBUFLEN,
7901 			    "process %ld %s", (long)job->jv_pid, status);
7902 # elif defined(MSWIN)
7903 		vim_snprintf((char *)buf, NUMBUFLEN,
7904 			    "process %ld %s",
7905 			    (long)job->jv_proc_info.dwProcessId,
7906 			    status);
7907 # else
7908 		/* fall-back */
7909 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
7910 # endif
7911 		return buf;
7912 	    }
7913 #endif
7914 	    break;
7915 	case VAR_CHANNEL:
7916 #ifdef FEAT_JOB_CHANNEL
7917 	    {
7918 		channel_T *channel = varp->vval.v_channel;
7919 		char      *status = channel_status(channel, -1);
7920 
7921 		if (channel == NULL)
7922 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
7923 		else
7924 		    vim_snprintf((char *)buf, NUMBUFLEN,
7925 				     "channel %d %s", channel->ch_id, status);
7926 		return buf;
7927 	    }
7928 #endif
7929 	    break;
7930 	case VAR_UNKNOWN:
7931 	    emsg(_("E908: using an invalid value as a String"));
7932 	    break;
7933     }
7934     return NULL;
7935 }
7936 
7937 /*
7938  * Turn a typeval into a string.  Similar to tv_get_string_buf() but uses
7939  * string() on Dict, List, etc.
7940  */
7941     char_u *
7942 tv_stringify(typval_T *varp, char_u *buf)
7943 {
7944     if (varp->v_type == VAR_LIST
7945 	    || varp->v_type == VAR_DICT
7946 	    || varp->v_type == VAR_FUNC
7947 	    || varp->v_type == VAR_PARTIAL
7948 	    || varp->v_type == VAR_FLOAT)
7949     {
7950 	typval_T tmp;
7951 
7952 	f_string(varp, &tmp);
7953 	tv_get_string_buf(&tmp, buf);
7954 	clear_tv(varp);
7955 	*varp = tmp;
7956 	return tmp.vval.v_string;
7957     }
7958     return tv_get_string_buf(varp, buf);
7959 }
7960 
7961 /*
7962  * Find variable "name" in the list of variables.
7963  * Return a pointer to it if found, NULL if not found.
7964  * Careful: "a:0" variables don't have a name.
7965  * When "htp" is not NULL we are writing to the variable, set "htp" to the
7966  * hashtab_T used.
7967  */
7968     dictitem_T *
7969 find_var(char_u *name, hashtab_T **htp, int no_autoload)
7970 {
7971     char_u	*varname;
7972     hashtab_T	*ht;
7973     dictitem_T	*ret = NULL;
7974 
7975     ht = find_var_ht(name, &varname);
7976     if (htp != NULL)
7977 	*htp = ht;
7978     if (ht == NULL)
7979 	return NULL;
7980     ret = find_var_in_ht(ht, *name, varname, no_autoload || htp != NULL);
7981     if (ret != NULL)
7982 	return ret;
7983 
7984     /* Search in parent scope for lambda */
7985     return find_var_in_scoped_ht(name, no_autoload || htp != NULL);
7986 }
7987 
7988 /*
7989  * Find variable "varname" in hashtab "ht" with name "htname".
7990  * Returns NULL if not found.
7991  */
7992     dictitem_T *
7993 find_var_in_ht(
7994     hashtab_T	*ht,
7995     int		htname,
7996     char_u	*varname,
7997     int		no_autoload)
7998 {
7999     hashitem_T	*hi;
8000 
8001     if (*varname == NUL)
8002     {
8003 	/* Must be something like "s:", otherwise "ht" would be NULL. */
8004 	switch (htname)
8005 	{
8006 	    case 's': return &SCRIPT_SV(current_sctx.sc_sid)->sv_var;
8007 	    case 'g': return &globvars_var;
8008 	    case 'v': return &vimvars_var;
8009 	    case 'b': return &curbuf->b_bufvar;
8010 	    case 'w': return &curwin->w_winvar;
8011 	    case 't': return &curtab->tp_winvar;
8012 	    case 'l': return get_funccal_local_var();
8013 	    case 'a': return get_funccal_args_var();
8014 	}
8015 	return NULL;
8016     }
8017 
8018     hi = hash_find(ht, varname);
8019     if (HASHITEM_EMPTY(hi))
8020     {
8021 	/* For global variables we may try auto-loading the script.  If it
8022 	 * worked find the variable again.  Don't auto-load a script if it was
8023 	 * loaded already, otherwise it would be loaded every time when
8024 	 * checking if a function name is a Funcref variable. */
8025 	if (ht == &globvarht && !no_autoload)
8026 	{
8027 	    /* Note: script_autoload() may make "hi" invalid. It must either
8028 	     * be obtained again or not used. */
8029 	    if (!script_autoload(varname, FALSE) || aborting())
8030 		return NULL;
8031 	    hi = hash_find(ht, varname);
8032 	}
8033 	if (HASHITEM_EMPTY(hi))
8034 	    return NULL;
8035     }
8036     return HI2DI(hi);
8037 }
8038 
8039 /*
8040  * Find the hashtab used for a variable name.
8041  * Return NULL if the name is not valid.
8042  * Set "varname" to the start of name without ':'.
8043  */
8044     hashtab_T *
8045 find_var_ht(char_u *name, char_u **varname)
8046 {
8047     hashitem_T	*hi;
8048     hashtab_T	*ht;
8049 
8050     if (name[0] == NUL)
8051 	return NULL;
8052     if (name[1] != ':')
8053     {
8054 	/* The name must not start with a colon or #. */
8055 	if (name[0] == ':' || name[0] == AUTOLOAD_CHAR)
8056 	    return NULL;
8057 	*varname = name;
8058 
8059 	// "version" is "v:version" in all scopes if scriptversion < 3.
8060 	// Same for a few other variables marked with VV_COMPAT.
8061 	if (current_sctx.sc_version < 3)
8062 	{
8063 	    hi = hash_find(&compat_hashtab, name);
8064 	    if (!HASHITEM_EMPTY(hi))
8065 		return &compat_hashtab;
8066 	}
8067 
8068 	ht = get_funccal_local_ht();
8069 	if (ht == NULL)
8070 	    return &globvarht;			/* global variable */
8071 	return ht;				/* local variable */
8072     }
8073     *varname = name + 2;
8074     if (*name == 'g')				/* global variable */
8075 	return &globvarht;
8076     // There must be no ':' or '#' in the rest of the name, unless g: is used
8077     if (vim_strchr(name + 2, ':') != NULL
8078 			       || vim_strchr(name + 2, AUTOLOAD_CHAR) != NULL)
8079 	return NULL;
8080     if (*name == 'b')				/* buffer variable */
8081 	return &curbuf->b_vars->dv_hashtab;
8082     if (*name == 'w')				/* window variable */
8083 	return &curwin->w_vars->dv_hashtab;
8084     if (*name == 't')				/* tab page variable */
8085 	return &curtab->tp_vars->dv_hashtab;
8086     if (*name == 'v')				/* v: variable */
8087 	return &vimvarht;
8088     if (*name == 'a')				/* a: function argument */
8089 	return get_funccal_args_ht();
8090     if (*name == 'l')				/* l: local function variable */
8091 	return get_funccal_local_ht();
8092     if (*name == 's'				/* script variable */
8093 	    && current_sctx.sc_sid > 0 && current_sctx.sc_sid <= ga_scripts.ga_len)
8094 	return &SCRIPT_VARS(current_sctx.sc_sid);
8095     return NULL;
8096 }
8097 
8098 /*
8099  * Get the string value of a (global/local) variable.
8100  * Note: see tv_get_string() for how long the pointer remains valid.
8101  * Returns NULL when it doesn't exist.
8102  */
8103     char_u *
8104 get_var_value(char_u *name)
8105 {
8106     dictitem_T	*v;
8107 
8108     v = find_var(name, NULL, FALSE);
8109     if (v == NULL)
8110 	return NULL;
8111     return tv_get_string(&v->di_tv);
8112 }
8113 
8114 /*
8115  * Allocate a new hashtab for a sourced script.  It will be used while
8116  * sourcing this script and when executing functions defined in the script.
8117  */
8118     void
8119 new_script_vars(scid_T id)
8120 {
8121     int		i;
8122     hashtab_T	*ht;
8123     scriptvar_T *sv;
8124 
8125     if (ga_grow(&ga_scripts, (int)(id - ga_scripts.ga_len)) == OK)
8126     {
8127 	/* Re-allocating ga_data means that an ht_array pointing to
8128 	 * ht_smallarray becomes invalid.  We can recognize this: ht_mask is
8129 	 * at its init value.  Also reset "v_dict", it's always the same. */
8130 	for (i = 1; i <= ga_scripts.ga_len; ++i)
8131 	{
8132 	    ht = &SCRIPT_VARS(i);
8133 	    if (ht->ht_mask == HT_INIT_SIZE - 1)
8134 		ht->ht_array = ht->ht_smallarray;
8135 	    sv = SCRIPT_SV(i);
8136 	    sv->sv_var.di_tv.vval.v_dict = &sv->sv_dict;
8137 	}
8138 
8139 	while (ga_scripts.ga_len < id)
8140 	{
8141 	    sv = SCRIPT_SV(ga_scripts.ga_len + 1) =
8142 		ALLOC_CLEAR_ONE(scriptvar_T);
8143 	    init_var_dict(&sv->sv_dict, &sv->sv_var, VAR_SCOPE);
8144 	    ++ga_scripts.ga_len;
8145 	}
8146     }
8147 }
8148 
8149 /*
8150  * Initialize dictionary "dict" as a scope and set variable "dict_var" to
8151  * point to it.
8152  */
8153     void
8154 init_var_dict(dict_T *dict, dictitem_T *dict_var, int scope)
8155 {
8156     hash_init(&dict->dv_hashtab);
8157     dict->dv_lock = 0;
8158     dict->dv_scope = scope;
8159     dict->dv_refcount = DO_NOT_FREE_CNT;
8160     dict->dv_copyID = 0;
8161     dict_var->di_tv.vval.v_dict = dict;
8162     dict_var->di_tv.v_type = VAR_DICT;
8163     dict_var->di_tv.v_lock = VAR_FIXED;
8164     dict_var->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
8165     dict_var->di_key[0] = NUL;
8166 }
8167 
8168 /*
8169  * Unreference a dictionary initialized by init_var_dict().
8170  */
8171     void
8172 unref_var_dict(dict_T *dict)
8173 {
8174     /* Now the dict needs to be freed if no one else is using it, go back to
8175      * normal reference counting. */
8176     dict->dv_refcount -= DO_NOT_FREE_CNT - 1;
8177     dict_unref(dict);
8178 }
8179 
8180 /*
8181  * Clean up a list of internal variables.
8182  * Frees all allocated variables and the value they contain.
8183  * Clears hashtab "ht", does not free it.
8184  */
8185     void
8186 vars_clear(hashtab_T *ht)
8187 {
8188     vars_clear_ext(ht, TRUE);
8189 }
8190 
8191 /*
8192  * Like vars_clear(), but only free the value if "free_val" is TRUE.
8193  */
8194     void
8195 vars_clear_ext(hashtab_T *ht, int free_val)
8196 {
8197     int		todo;
8198     hashitem_T	*hi;
8199     dictitem_T	*v;
8200 
8201     hash_lock(ht);
8202     todo = (int)ht->ht_used;
8203     for (hi = ht->ht_array; todo > 0; ++hi)
8204     {
8205 	if (!HASHITEM_EMPTY(hi))
8206 	{
8207 	    --todo;
8208 
8209 	    /* Free the variable.  Don't remove it from the hashtab,
8210 	     * ht_array might change then.  hash_clear() takes care of it
8211 	     * later. */
8212 	    v = HI2DI(hi);
8213 	    if (free_val)
8214 		clear_tv(&v->di_tv);
8215 	    if (v->di_flags & DI_FLAGS_ALLOC)
8216 		vim_free(v);
8217 	}
8218     }
8219     hash_clear(ht);
8220     ht->ht_used = 0;
8221 }
8222 
8223 /*
8224  * Delete a variable from hashtab "ht" at item "hi".
8225  * Clear the variable value and free the dictitem.
8226  */
8227     static void
8228 delete_var(hashtab_T *ht, hashitem_T *hi)
8229 {
8230     dictitem_T	*di = HI2DI(hi);
8231 
8232     hash_remove(ht, hi);
8233     clear_tv(&di->di_tv);
8234     vim_free(di);
8235 }
8236 
8237 /*
8238  * List the value of one internal variable.
8239  */
8240     static void
8241 list_one_var(dictitem_T *v, char *prefix, int *first)
8242 {
8243     char_u	*tofree;
8244     char_u	*s;
8245     char_u	numbuf[NUMBUFLEN];
8246 
8247     s = echo_string(&v->di_tv, &tofree, numbuf, get_copyID());
8248     list_one_var_a(prefix, v->di_key, v->di_tv.v_type,
8249 					 s == NULL ? (char_u *)"" : s, first);
8250     vim_free(tofree);
8251 }
8252 
8253     static void
8254 list_one_var_a(
8255     char	*prefix,
8256     char_u	*name,
8257     int		type,
8258     char_u	*string,
8259     int		*first)  /* when TRUE clear rest of screen and set to FALSE */
8260 {
8261     /* don't use msg() or msg_attr() to avoid overwriting "v:statusmsg" */
8262     msg_start();
8263     msg_puts(prefix);
8264     if (name != NULL)	/* "a:" vars don't have a name stored */
8265 	msg_puts((char *)name);
8266     msg_putchar(' ');
8267     msg_advance(22);
8268     if (type == VAR_NUMBER)
8269 	msg_putchar('#');
8270     else if (type == VAR_FUNC || type == VAR_PARTIAL)
8271 	msg_putchar('*');
8272     else if (type == VAR_LIST)
8273     {
8274 	msg_putchar('[');
8275 	if (*string == '[')
8276 	    ++string;
8277     }
8278     else if (type == VAR_DICT)
8279     {
8280 	msg_putchar('{');
8281 	if (*string == '{')
8282 	    ++string;
8283     }
8284     else
8285 	msg_putchar(' ');
8286 
8287     msg_outtrans(string);
8288 
8289     if (type == VAR_FUNC || type == VAR_PARTIAL)
8290 	msg_puts("()");
8291     if (*first)
8292     {
8293 	msg_clr_eos();
8294 	*first = FALSE;
8295     }
8296 }
8297 
8298 /*
8299  * Set variable "name" to value in "tv".
8300  * If the variable already exists, the value is updated.
8301  * Otherwise the variable is created.
8302  */
8303     void
8304 set_var(
8305     char_u	*name,
8306     typval_T	*tv,
8307     int		copy)	    // make copy of value in "tv"
8308 {
8309     set_var_const(name, tv, copy, FALSE);
8310 }
8311 
8312 /*
8313  * Set variable "name" to value in "tv".
8314  * If the variable already exists and "is_const" is FALSE the value is updated.
8315  * Otherwise the variable is created.
8316  */
8317     static void
8318 set_var_const(
8319     char_u	*name,
8320     typval_T	*tv,
8321     int		copy,	    // make copy of value in "tv"
8322     int		is_const)   // disallow to modify existing variable
8323 {
8324     dictitem_T	*v;
8325     char_u	*varname;
8326     hashtab_T	*ht;
8327 
8328     ht = find_var_ht(name, &varname);
8329     if (ht == NULL || *varname == NUL)
8330     {
8331 	semsg(_(e_illvar), name);
8332 	return;
8333     }
8334     v = find_var_in_ht(ht, 0, varname, TRUE);
8335 
8336     /* Search in parent scope which is possible to reference from lambda */
8337     if (v == NULL)
8338 	v = find_var_in_scoped_ht(name, TRUE);
8339 
8340     if ((tv->v_type == VAR_FUNC || tv->v_type == VAR_PARTIAL)
8341 				      && var_check_func_name(name, v == NULL))
8342 	return;
8343 
8344     if (v != NULL)
8345     {
8346 	if (is_const)
8347 	{
8348 	    emsg(_(e_cannot_mod));
8349 	    return;
8350 	}
8351 
8352 	/* existing variable, need to clear the value */
8353 	if (var_check_ro(v->di_flags, name, FALSE)
8354 			      || var_check_lock(v->di_tv.v_lock, name, FALSE))
8355 	    return;
8356 
8357 	/*
8358 	 * Handle setting internal v: variables separately where needed to
8359 	 * prevent changing the type.
8360 	 */
8361 	if (ht == &vimvarht)
8362 	{
8363 	    if (v->di_tv.v_type == VAR_STRING)
8364 	    {
8365 		VIM_CLEAR(v->di_tv.vval.v_string);
8366 		if (copy || tv->v_type != VAR_STRING)
8367 		{
8368 		    char_u *val = tv_get_string(tv);
8369 
8370 		    // Careful: when assigning to v:errmsg and tv_get_string()
8371 		    // causes an error message the variable will alrady be set.
8372 		    if (v->di_tv.vval.v_string == NULL)
8373 			v->di_tv.vval.v_string = vim_strsave(val);
8374 		}
8375 		else
8376 		{
8377 		    /* Take over the string to avoid an extra alloc/free. */
8378 		    v->di_tv.vval.v_string = tv->vval.v_string;
8379 		    tv->vval.v_string = NULL;
8380 		}
8381 		return;
8382 	    }
8383 	    else if (v->di_tv.v_type == VAR_NUMBER)
8384 	    {
8385 		v->di_tv.vval.v_number = tv_get_number(tv);
8386 		if (STRCMP(varname, "searchforward") == 0)
8387 		    set_search_direction(v->di_tv.vval.v_number ? '/' : '?');
8388 #ifdef FEAT_SEARCH_EXTRA
8389 		else if (STRCMP(varname, "hlsearch") == 0)
8390 		{
8391 		    no_hlsearch = !v->di_tv.vval.v_number;
8392 		    redraw_all_later(SOME_VALID);
8393 		}
8394 #endif
8395 		return;
8396 	    }
8397 	    else if (v->di_tv.v_type != tv->v_type)
8398 	    {
8399 		semsg(_("E963: setting %s to value with wrong type"), name);
8400 		return;
8401 	    }
8402 	}
8403 
8404 	clear_tv(&v->di_tv);
8405     }
8406     else		    /* add a new variable */
8407     {
8408 	// Can't add "v:" or "a:" variable.
8409 	if (ht == &vimvarht || ht == get_funccal_args_ht())
8410 	{
8411 	    semsg(_(e_illvar), name);
8412 	    return;
8413 	}
8414 
8415 	// Make sure the variable name is valid.
8416 	if (!valid_varname(varname))
8417 	    return;
8418 
8419 	v = alloc(sizeof(dictitem_T) + STRLEN(varname));
8420 	if (v == NULL)
8421 	    return;
8422 	STRCPY(v->di_key, varname);
8423 	if (hash_add(ht, DI2HIKEY(v)) == FAIL)
8424 	{
8425 	    vim_free(v);
8426 	    return;
8427 	}
8428 	v->di_flags = DI_FLAGS_ALLOC;
8429 	if (is_const)
8430 	    v->di_flags |= DI_FLAGS_LOCK;
8431     }
8432 
8433     if (copy || tv->v_type == VAR_NUMBER || tv->v_type == VAR_FLOAT)
8434 	copy_tv(tv, &v->di_tv);
8435     else
8436     {
8437 	v->di_tv = *tv;
8438 	v->di_tv.v_lock = 0;
8439 	init_tv(tv);
8440     }
8441 
8442     if (is_const)
8443 	v->di_tv.v_lock |= VAR_LOCKED;
8444 }
8445 
8446 /*
8447  * Return TRUE if di_flags "flags" indicates variable "name" is read-only.
8448  * Also give an error message.
8449  */
8450     int
8451 var_check_ro(int flags, char_u *name, int use_gettext)
8452 {
8453     if (flags & DI_FLAGS_RO)
8454     {
8455 	semsg(_(e_readonlyvar), use_gettext ? (char_u *)_(name) : name);
8456 	return TRUE;
8457     }
8458     if ((flags & DI_FLAGS_RO_SBX) && sandbox)
8459     {
8460 	semsg(_(e_readonlysbx), use_gettext ? (char_u *)_(name) : name);
8461 	return TRUE;
8462     }
8463     return FALSE;
8464 }
8465 
8466 /*
8467  * Return TRUE if di_flags "flags" indicates variable "name" is fixed.
8468  * Also give an error message.
8469  */
8470     int
8471 var_check_fixed(int flags, char_u *name, int use_gettext)
8472 {
8473     if (flags & DI_FLAGS_FIX)
8474     {
8475 	semsg(_("E795: Cannot delete variable %s"),
8476 				      use_gettext ? (char_u *)_(name) : name);
8477 	return TRUE;
8478     }
8479     return FALSE;
8480 }
8481 
8482 /*
8483  * Check if a funcref is assigned to a valid variable name.
8484  * Return TRUE and give an error if not.
8485  */
8486     int
8487 var_check_func_name(
8488     char_u *name,    /* points to start of variable name */
8489     int    new_var)  /* TRUE when creating the variable */
8490 {
8491     /* Allow for w: b: s: and t:. */
8492     if (!(vim_strchr((char_u *)"wbst", name[0]) != NULL && name[1] == ':')
8493 	    && !ASCII_ISUPPER((name[0] != NUL && name[1] == ':')
8494 						     ? name[2] : name[0]))
8495     {
8496 	semsg(_("E704: Funcref variable name must start with a capital: %s"),
8497 									name);
8498 	return TRUE;
8499     }
8500     /* Don't allow hiding a function.  When "v" is not NULL we might be
8501      * assigning another function to the same var, the type is checked
8502      * below. */
8503     if (new_var && function_exists(name, FALSE))
8504     {
8505 	semsg(_("E705: Variable name conflicts with existing function: %s"),
8506 								    name);
8507 	return TRUE;
8508     }
8509     return FALSE;
8510 }
8511 
8512 /*
8513  * Return TRUE if "flags" indicates variable "name" is locked (immutable).
8514  * Also give an error message, using "name" or _("name") when use_gettext is
8515  * TRUE.
8516  */
8517     int
8518 var_check_lock(int lock, char_u *name, int use_gettext)
8519 {
8520     if (lock & VAR_LOCKED)
8521     {
8522 	semsg(_("E741: Value is locked: %s"),
8523 				name == NULL ? (char_u *)_("Unknown")
8524 					     : use_gettext ? (char_u *)_(name)
8525 					     : name);
8526 	return TRUE;
8527     }
8528     if (lock & VAR_FIXED)
8529     {
8530 	semsg(_("E742: Cannot change value of %s"),
8531 				name == NULL ? (char_u *)_("Unknown")
8532 					     : use_gettext ? (char_u *)_(name)
8533 					     : name);
8534 	return TRUE;
8535     }
8536     return FALSE;
8537 }
8538 
8539 /*
8540  * Return TRUE if typeval "tv" and its value are set to be locked (immutable).
8541  * Also give an error message, using "name" or _("name") when use_gettext is
8542  * TRUE.
8543  */
8544     static int
8545 tv_check_lock(typval_T *tv, char_u *name, int use_gettext)
8546 {
8547     int	lock = 0;
8548 
8549     switch (tv->v_type)
8550     {
8551 	case VAR_BLOB:
8552 	    if (tv->vval.v_blob != NULL)
8553 		lock = tv->vval.v_blob->bv_lock;
8554 	    break;
8555 	case VAR_LIST:
8556 	    if (tv->vval.v_list != NULL)
8557 		lock = tv->vval.v_list->lv_lock;
8558 	    break;
8559 	case VAR_DICT:
8560 	    if (tv->vval.v_dict != NULL)
8561 		lock = tv->vval.v_dict->dv_lock;
8562 	    break;
8563 	default:
8564 	    break;
8565     }
8566     return var_check_lock(tv->v_lock, name, use_gettext)
8567 		    || (lock != 0 && var_check_lock(lock, name, use_gettext));
8568 }
8569 
8570 /*
8571  * Check if a variable name is valid.
8572  * Return FALSE and give an error if not.
8573  */
8574     int
8575 valid_varname(char_u *varname)
8576 {
8577     char_u *p;
8578 
8579     for (p = varname; *p != NUL; ++p)
8580 	if (!eval_isnamec1(*p) && (p == varname || !VIM_ISDIGIT(*p))
8581 						   && *p != AUTOLOAD_CHAR)
8582 	{
8583 	    semsg(_(e_illvar), varname);
8584 	    return FALSE;
8585 	}
8586     return TRUE;
8587 }
8588 
8589 /*
8590  * Copy the values from typval_T "from" to typval_T "to".
8591  * When needed allocates string or increases reference count.
8592  * Does not make a copy of a list, blob or dict but copies the reference!
8593  * It is OK for "from" and "to" to point to the same item.  This is used to
8594  * make a copy later.
8595  */
8596     void
8597 copy_tv(typval_T *from, typval_T *to)
8598 {
8599     to->v_type = from->v_type;
8600     to->v_lock = 0;
8601     switch (from->v_type)
8602     {
8603 	case VAR_NUMBER:
8604 	case VAR_SPECIAL:
8605 	    to->vval.v_number = from->vval.v_number;
8606 	    break;
8607 	case VAR_FLOAT:
8608 #ifdef FEAT_FLOAT
8609 	    to->vval.v_float = from->vval.v_float;
8610 	    break;
8611 #endif
8612 	case VAR_JOB:
8613 #ifdef FEAT_JOB_CHANNEL
8614 	    to->vval.v_job = from->vval.v_job;
8615 	    if (to->vval.v_job != NULL)
8616 		++to->vval.v_job->jv_refcount;
8617 	    break;
8618 #endif
8619 	case VAR_CHANNEL:
8620 #ifdef FEAT_JOB_CHANNEL
8621 	    to->vval.v_channel = from->vval.v_channel;
8622 	    if (to->vval.v_channel != NULL)
8623 		++to->vval.v_channel->ch_refcount;
8624 	    break;
8625 #endif
8626 	case VAR_STRING:
8627 	case VAR_FUNC:
8628 	    if (from->vval.v_string == NULL)
8629 		to->vval.v_string = NULL;
8630 	    else
8631 	    {
8632 		to->vval.v_string = vim_strsave(from->vval.v_string);
8633 		if (from->v_type == VAR_FUNC)
8634 		    func_ref(to->vval.v_string);
8635 	    }
8636 	    break;
8637 	case VAR_PARTIAL:
8638 	    if (from->vval.v_partial == NULL)
8639 		to->vval.v_partial = NULL;
8640 	    else
8641 	    {
8642 		to->vval.v_partial = from->vval.v_partial;
8643 		++to->vval.v_partial->pt_refcount;
8644 	    }
8645 	    break;
8646 	case VAR_BLOB:
8647 	    if (from->vval.v_blob == NULL)
8648 		to->vval.v_blob = NULL;
8649 	    else
8650 	    {
8651 		to->vval.v_blob = from->vval.v_blob;
8652 		++to->vval.v_blob->bv_refcount;
8653 	    }
8654 	    break;
8655 	case VAR_LIST:
8656 	    if (from->vval.v_list == NULL)
8657 		to->vval.v_list = NULL;
8658 	    else
8659 	    {
8660 		to->vval.v_list = from->vval.v_list;
8661 		++to->vval.v_list->lv_refcount;
8662 	    }
8663 	    break;
8664 	case VAR_DICT:
8665 	    if (from->vval.v_dict == NULL)
8666 		to->vval.v_dict = NULL;
8667 	    else
8668 	    {
8669 		to->vval.v_dict = from->vval.v_dict;
8670 		++to->vval.v_dict->dv_refcount;
8671 	    }
8672 	    break;
8673 	case VAR_UNKNOWN:
8674 	    internal_error("copy_tv(UNKNOWN)");
8675 	    break;
8676     }
8677 }
8678 
8679 /*
8680  * Make a copy of an item.
8681  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
8682  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
8683  * reference to an already copied list/dict can be used.
8684  * Returns FAIL or OK.
8685  */
8686     int
8687 item_copy(
8688     typval_T	*from,
8689     typval_T	*to,
8690     int		deep,
8691     int		copyID)
8692 {
8693     static int	recurse = 0;
8694     int		ret = OK;
8695 
8696     if (recurse >= DICT_MAXNEST)
8697     {
8698 	emsg(_("E698: variable nested too deep for making a copy"));
8699 	return FAIL;
8700     }
8701     ++recurse;
8702 
8703     switch (from->v_type)
8704     {
8705 	case VAR_NUMBER:
8706 	case VAR_FLOAT:
8707 	case VAR_STRING:
8708 	case VAR_FUNC:
8709 	case VAR_PARTIAL:
8710 	case VAR_SPECIAL:
8711 	case VAR_JOB:
8712 	case VAR_CHANNEL:
8713 	    copy_tv(from, to);
8714 	    break;
8715 	case VAR_LIST:
8716 	    to->v_type = VAR_LIST;
8717 	    to->v_lock = 0;
8718 	    if (from->vval.v_list == NULL)
8719 		to->vval.v_list = NULL;
8720 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
8721 	    {
8722 		/* use the copy made earlier */
8723 		to->vval.v_list = from->vval.v_list->lv_copylist;
8724 		++to->vval.v_list->lv_refcount;
8725 	    }
8726 	    else
8727 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
8728 	    if (to->vval.v_list == NULL)
8729 		ret = FAIL;
8730 	    break;
8731 	case VAR_BLOB:
8732 	    ret = blob_copy(from, to);
8733 	    break;
8734 	case VAR_DICT:
8735 	    to->v_type = VAR_DICT;
8736 	    to->v_lock = 0;
8737 	    if (from->vval.v_dict == NULL)
8738 		to->vval.v_dict = NULL;
8739 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
8740 	    {
8741 		/* use the copy made earlier */
8742 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
8743 		++to->vval.v_dict->dv_refcount;
8744 	    }
8745 	    else
8746 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
8747 	    if (to->vval.v_dict == NULL)
8748 		ret = FAIL;
8749 	    break;
8750 	case VAR_UNKNOWN:
8751 	    internal_error("item_copy(UNKNOWN)");
8752 	    ret = FAIL;
8753     }
8754     --recurse;
8755     return ret;
8756 }
8757 
8758 /*
8759  * This function is used by f_input() and f_inputdialog() functions. The third
8760  * argument to f_input() specifies the type of completion to use at the
8761  * prompt. The third argument to f_inputdialog() specifies the value to return
8762  * when the user cancels the prompt.
8763  */
8764     void
8765 get_user_input(
8766     typval_T	*argvars,
8767     typval_T	*rettv,
8768     int		inputdialog,
8769     int		secret)
8770 {
8771     char_u	*prompt = tv_get_string_chk(&argvars[0]);
8772     char_u	*p = NULL;
8773     int		c;
8774     char_u	buf[NUMBUFLEN];
8775     int		cmd_silent_save = cmd_silent;
8776     char_u	*defstr = (char_u *)"";
8777     int		xp_type = EXPAND_NOTHING;
8778     char_u	*xp_arg = NULL;
8779 
8780     rettv->v_type = VAR_STRING;
8781     rettv->vval.v_string = NULL;
8782 
8783 #ifdef NO_CONSOLE_INPUT
8784     /* While starting up, there is no place to enter text. When running tests
8785      * with --not-a-term we assume feedkeys() will be used. */
8786     if (no_console_input() && !is_not_a_term())
8787 	return;
8788 #endif
8789 
8790     cmd_silent = FALSE;		/* Want to see the prompt. */
8791     if (prompt != NULL)
8792     {
8793 	/* Only the part of the message after the last NL is considered as
8794 	 * prompt for the command line */
8795 	p = vim_strrchr(prompt, '\n');
8796 	if (p == NULL)
8797 	    p = prompt;
8798 	else
8799 	{
8800 	    ++p;
8801 	    c = *p;
8802 	    *p = NUL;
8803 	    msg_start();
8804 	    msg_clr_eos();
8805 	    msg_puts_attr((char *)prompt, echo_attr);
8806 	    msg_didout = FALSE;
8807 	    msg_starthere();
8808 	    *p = c;
8809 	}
8810 	cmdline_row = msg_row;
8811 
8812 	if (argvars[1].v_type != VAR_UNKNOWN)
8813 	{
8814 	    defstr = tv_get_string_buf_chk(&argvars[1], buf);
8815 	    if (defstr != NULL)
8816 		stuffReadbuffSpec(defstr);
8817 
8818 	    if (!inputdialog && argvars[2].v_type != VAR_UNKNOWN)
8819 	    {
8820 		char_u	*xp_name;
8821 		int	xp_namelen;
8822 		long	argt;
8823 
8824 		/* input() with a third argument: completion */
8825 		rettv->vval.v_string = NULL;
8826 
8827 		xp_name = tv_get_string_buf_chk(&argvars[2], buf);
8828 		if (xp_name == NULL)
8829 		    return;
8830 
8831 		xp_namelen = (int)STRLEN(xp_name);
8832 
8833 		if (parse_compl_arg(xp_name, xp_namelen, &xp_type, &argt,
8834 							     &xp_arg) == FAIL)
8835 		    return;
8836 	    }
8837 	}
8838 
8839 	if (defstr != NULL)
8840 	{
8841 	    int save_ex_normal_busy = ex_normal_busy;
8842 
8843 	    ex_normal_busy = 0;
8844 	    rettv->vval.v_string =
8845 		getcmdline_prompt(secret ? NUL : '@', p, echo_attr,
8846 							      xp_type, xp_arg);
8847 	    ex_normal_busy = save_ex_normal_busy;
8848 	}
8849 	if (inputdialog && rettv->vval.v_string == NULL
8850 		&& argvars[1].v_type != VAR_UNKNOWN
8851 		&& argvars[2].v_type != VAR_UNKNOWN)
8852 	    rettv->vval.v_string = vim_strsave(tv_get_string_buf(
8853 							   &argvars[2], buf));
8854 
8855 	vim_free(xp_arg);
8856 
8857 	/* since the user typed this, no need to wait for return */
8858 	need_wait_return = FALSE;
8859 	msg_didout = FALSE;
8860     }
8861     cmd_silent = cmd_silent_save;
8862 }
8863 
8864 /*
8865  * ":echo expr1 ..."	print each argument separated with a space, add a
8866  *			newline at the end.
8867  * ":echon expr1 ..."	print each argument plain.
8868  */
8869     void
8870 ex_echo(exarg_T *eap)
8871 {
8872     char_u	*arg = eap->arg;
8873     typval_T	rettv;
8874     char_u	*tofree;
8875     char_u	*p;
8876     int		needclr = TRUE;
8877     int		atstart = TRUE;
8878     char_u	numbuf[NUMBUFLEN];
8879     int		did_emsg_before = did_emsg;
8880     int		called_emsg_before = called_emsg;
8881 
8882     if (eap->skip)
8883 	++emsg_skip;
8884     while (*arg != NUL && *arg != '|' && *arg != '\n' && !got_int)
8885     {
8886 	/* If eval1() causes an error message the text from the command may
8887 	 * still need to be cleared. E.g., "echo 22,44". */
8888 	need_clr_eos = needclr;
8889 
8890 	p = arg;
8891 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8892 	{
8893 	    /*
8894 	     * Report the invalid expression unless the expression evaluation
8895 	     * has been cancelled due to an aborting error, an interrupt, or an
8896 	     * exception.
8897 	     */
8898 	    if (!aborting() && did_emsg == did_emsg_before
8899 					  && called_emsg == called_emsg_before)
8900 		semsg(_(e_invexpr2), p);
8901 	    need_clr_eos = FALSE;
8902 	    break;
8903 	}
8904 	need_clr_eos = FALSE;
8905 
8906 	if (!eap->skip)
8907 	{
8908 	    if (atstart)
8909 	    {
8910 		atstart = FALSE;
8911 		/* Call msg_start() after eval1(), evaluating the expression
8912 		 * may cause a message to appear. */
8913 		if (eap->cmdidx == CMD_echo)
8914 		{
8915 		    /* Mark the saved text as finishing the line, so that what
8916 		     * follows is displayed on a new line when scrolling back
8917 		     * at the more prompt. */
8918 		    msg_sb_eol();
8919 		    msg_start();
8920 		}
8921 	    }
8922 	    else if (eap->cmdidx == CMD_echo)
8923 		msg_puts_attr(" ", echo_attr);
8924 	    p = echo_string(&rettv, &tofree, numbuf, get_copyID());
8925 	    if (p != NULL)
8926 		for ( ; *p != NUL && !got_int; ++p)
8927 		{
8928 		    if (*p == '\n' || *p == '\r' || *p == TAB)
8929 		    {
8930 			if (*p != TAB && needclr)
8931 			{
8932 			    /* remove any text still there from the command */
8933 			    msg_clr_eos();
8934 			    needclr = FALSE;
8935 			}
8936 			msg_putchar_attr(*p, echo_attr);
8937 		    }
8938 		    else
8939 		    {
8940 			if (has_mbyte)
8941 			{
8942 			    int i = (*mb_ptr2len)(p);
8943 
8944 			    (void)msg_outtrans_len_attr(p, i, echo_attr);
8945 			    p += i - 1;
8946 			}
8947 			else
8948 			    (void)msg_outtrans_len_attr(p, 1, echo_attr);
8949 		    }
8950 		}
8951 	    vim_free(tofree);
8952 	}
8953 	clear_tv(&rettv);
8954 	arg = skipwhite(arg);
8955     }
8956     eap->nextcmd = check_nextcmd(arg);
8957 
8958     if (eap->skip)
8959 	--emsg_skip;
8960     else
8961     {
8962 	/* remove text that may still be there from the command */
8963 	if (needclr)
8964 	    msg_clr_eos();
8965 	if (eap->cmdidx == CMD_echo)
8966 	    msg_end();
8967     }
8968 }
8969 
8970 /*
8971  * ":echohl {name}".
8972  */
8973     void
8974 ex_echohl(exarg_T *eap)
8975 {
8976     echo_attr = syn_name2attr(eap->arg);
8977 }
8978 
8979 /*
8980  * ":execute expr1 ..."	execute the result of an expression.
8981  * ":echomsg expr1 ..."	Print a message
8982  * ":echoerr expr1 ..."	Print an error
8983  * Each gets spaces around each argument and a newline at the end for
8984  * echo commands
8985  */
8986     void
8987 ex_execute(exarg_T *eap)
8988 {
8989     char_u	*arg = eap->arg;
8990     typval_T	rettv;
8991     int		ret = OK;
8992     char_u	*p;
8993     garray_T	ga;
8994     int		len;
8995     int		save_did_emsg;
8996 
8997     ga_init2(&ga, 1, 80);
8998 
8999     if (eap->skip)
9000 	++emsg_skip;
9001     while (*arg != NUL && *arg != '|' && *arg != '\n')
9002     {
9003 	ret = eval1_emsg(&arg, &rettv, !eap->skip);
9004 	if (ret == FAIL)
9005 	    break;
9006 
9007 	if (!eap->skip)
9008 	{
9009 	    char_u   buf[NUMBUFLEN];
9010 
9011 	    if (eap->cmdidx == CMD_execute)
9012 		p = tv_get_string_buf(&rettv, buf);
9013 	    else
9014 		p = tv_stringify(&rettv, buf);
9015 	    len = (int)STRLEN(p);
9016 	    if (ga_grow(&ga, len + 2) == FAIL)
9017 	    {
9018 		clear_tv(&rettv);
9019 		ret = FAIL;
9020 		break;
9021 	    }
9022 	    if (ga.ga_len)
9023 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
9024 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
9025 	    ga.ga_len += len;
9026 	}
9027 
9028 	clear_tv(&rettv);
9029 	arg = skipwhite(arg);
9030     }
9031 
9032     if (ret != FAIL && ga.ga_data != NULL)
9033     {
9034 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
9035 	{
9036 	    /* Mark the already saved text as finishing the line, so that what
9037 	     * follows is displayed on a new line when scrolling back at the
9038 	     * more prompt. */
9039 	    msg_sb_eol();
9040 	}
9041 
9042 	if (eap->cmdidx == CMD_echomsg)
9043 	{
9044 	    msg_attr(ga.ga_data, echo_attr);
9045 	    out_flush();
9046 	}
9047 	else if (eap->cmdidx == CMD_echoerr)
9048 	{
9049 	    /* We don't want to abort following commands, restore did_emsg. */
9050 	    save_did_emsg = did_emsg;
9051 	    emsg(ga.ga_data);
9052 	    if (!force_abort)
9053 		did_emsg = save_did_emsg;
9054 	}
9055 	else if (eap->cmdidx == CMD_execute)
9056 	    do_cmdline((char_u *)ga.ga_data,
9057 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
9058     }
9059 
9060     ga_clear(&ga);
9061 
9062     if (eap->skip)
9063 	--emsg_skip;
9064 
9065     eap->nextcmd = check_nextcmd(arg);
9066 }
9067 
9068 /*
9069  * Find window specified by "vp" in tabpage "tp".
9070  */
9071     win_T *
9072 find_win_by_nr(
9073     typval_T	*vp,
9074     tabpage_T	*tp)	/* NULL for current tab page */
9075 {
9076     win_T	*wp;
9077     int		nr = (int)tv_get_number_chk(vp, NULL);
9078 
9079     if (nr < 0)
9080 	return NULL;
9081     if (nr == 0)
9082 	return curwin;
9083 
9084     FOR_ALL_WINDOWS_IN_TAB(tp, wp)
9085     {
9086 	if (nr >= LOWEST_WIN_ID)
9087 	{
9088 	    if (wp->w_id == nr)
9089 		return wp;
9090 	}
9091 	else if (--nr <= 0)
9092 	    break;
9093     }
9094     if (nr >= LOWEST_WIN_ID)
9095     {
9096 #ifdef FEAT_TEXT_PROP
9097 	// check tab-local popup windows
9098 	for (wp = tp->tp_first_popupwin; wp != NULL; wp = wp->w_next)
9099 	    if (wp->w_id == nr)
9100 		return wp;
9101 	// check global popup windows
9102 	for (wp = first_popupwin; wp != NULL; wp = wp->w_next)
9103 	    if (wp->w_id == nr)
9104 		return wp;
9105 #endif
9106 	return NULL;
9107     }
9108     return wp;
9109 }
9110 
9111 /*
9112  * Find a window: When using a Window ID in any tab page, when using a number
9113  * in the current tab page.
9114  */
9115     win_T *
9116 find_win_by_nr_or_id(typval_T *vp)
9117 {
9118     int	nr = (int)tv_get_number_chk(vp, NULL);
9119 
9120     if (nr >= LOWEST_WIN_ID)
9121 	return win_id2wp(tv_get_number(vp));
9122     return find_win_by_nr(vp, NULL);
9123 }
9124 
9125 /*
9126  * Find window specified by "wvp" in tabpage "tvp".
9127  * Returns the tab page in 'ptp'
9128  */
9129     win_T *
9130 find_tabwin(
9131     typval_T	*wvp,	// VAR_UNKNOWN for current window
9132     typval_T	*tvp,	// VAR_UNKNOWN for current tab page
9133     tabpage_T	**ptp)
9134 {
9135     win_T	*wp = NULL;
9136     tabpage_T	*tp = NULL;
9137     long	n;
9138 
9139     if (wvp->v_type != VAR_UNKNOWN)
9140     {
9141 	if (tvp->v_type != VAR_UNKNOWN)
9142 	{
9143 	    n = (long)tv_get_number(tvp);
9144 	    if (n >= 0)
9145 		tp = find_tabpage(n);
9146 	}
9147 	else
9148 	    tp = curtab;
9149 
9150 	if (tp != NULL)
9151 	{
9152 	    wp = find_win_by_nr(wvp, tp);
9153 	    if (wp == NULL && wvp->v_type == VAR_NUMBER
9154 						&& wvp->vval.v_number != -1)
9155 		// A window with the specified number is not found
9156 		tp = NULL;
9157 	}
9158     }
9159     else
9160     {
9161 	wp = curwin;
9162 	tp = curtab;
9163     }
9164 
9165     if (ptp != NULL)
9166 	*ptp = tp;
9167 
9168     return wp;
9169 }
9170 
9171 /*
9172  * getwinvar() and gettabwinvar()
9173  */
9174     void
9175 getwinvar(
9176     typval_T	*argvars,
9177     typval_T	*rettv,
9178     int		off)	    /* 1 for gettabwinvar() */
9179 {
9180     win_T	*win;
9181     char_u	*varname;
9182     dictitem_T	*v;
9183     tabpage_T	*tp = NULL;
9184     int		done = FALSE;
9185     win_T	*oldcurwin;
9186     tabpage_T	*oldtabpage;
9187     int		need_switch_win;
9188 
9189     if (off == 1)
9190 	tp = find_tabpage((int)tv_get_number_chk(&argvars[0], NULL));
9191     else
9192 	tp = curtab;
9193     win = find_win_by_nr(&argvars[off], tp);
9194     varname = tv_get_string_chk(&argvars[off + 1]);
9195     ++emsg_off;
9196 
9197     rettv->v_type = VAR_STRING;
9198     rettv->vval.v_string = NULL;
9199 
9200     if (win != NULL && varname != NULL)
9201     {
9202 	/* Set curwin to be our win, temporarily.  Also set the tabpage,
9203 	 * otherwise the window is not valid. Only do this when needed,
9204 	 * autocommands get blocked. */
9205 	need_switch_win = !(tp == curtab && win == curwin);
9206 	if (!need_switch_win
9207 		  || switch_win(&oldcurwin, &oldtabpage, win, tp, TRUE) == OK)
9208 	{
9209 	    if (*varname == '&')
9210 	    {
9211 		if (varname[1] == NUL)
9212 		{
9213 		    /* get all window-local options in a dict */
9214 		    dict_T	*opts = get_winbuf_options(FALSE);
9215 
9216 		    if (opts != NULL)
9217 		    {
9218 			rettv_dict_set(rettv, opts);
9219 			done = TRUE;
9220 		    }
9221 		}
9222 		else if (get_option_tv(&varname, rettv, 1) == OK)
9223 		    /* window-local-option */
9224 		    done = TRUE;
9225 	    }
9226 	    else
9227 	    {
9228 		/* Look up the variable. */
9229 		/* Let getwinvar({nr}, "") return the "w:" dictionary. */
9230 		v = find_var_in_ht(&win->w_vars->dv_hashtab, 'w',
9231 							      varname, FALSE);
9232 		if (v != NULL)
9233 		{
9234 		    copy_tv(&v->di_tv, rettv);
9235 		    done = TRUE;
9236 		}
9237 	    }
9238 	}
9239 
9240 	if (need_switch_win)
9241 	    /* restore previous notion of curwin */
9242 	    restore_win(oldcurwin, oldtabpage, TRUE);
9243     }
9244 
9245     if (!done && argvars[off + 2].v_type != VAR_UNKNOWN)
9246 	/* use the default return value */
9247 	copy_tv(&argvars[off + 2], rettv);
9248 
9249     --emsg_off;
9250 }
9251 
9252 /*
9253  * "setwinvar()" and "settabwinvar()" functions
9254  */
9255     void
9256 setwinvar(typval_T *argvars, typval_T *rettv UNUSED, int off)
9257 {
9258     win_T	*win;
9259     win_T	*save_curwin;
9260     tabpage_T	*save_curtab;
9261     int		need_switch_win;
9262     char_u	*varname, *winvarname;
9263     typval_T	*varp;
9264     char_u	nbuf[NUMBUFLEN];
9265     tabpage_T	*tp = NULL;
9266 
9267     if (check_secure())
9268 	return;
9269 
9270     if (off == 1)
9271 	tp = find_tabpage((int)tv_get_number_chk(&argvars[0], NULL));
9272     else
9273 	tp = curtab;
9274     win = find_win_by_nr(&argvars[off], tp);
9275     varname = tv_get_string_chk(&argvars[off + 1]);
9276     varp = &argvars[off + 2];
9277 
9278     if (win != NULL && varname != NULL && varp != NULL)
9279     {
9280 	need_switch_win = !(tp == curtab && win == curwin);
9281 	if (!need_switch_win
9282 	       || switch_win(&save_curwin, &save_curtab, win, tp, TRUE) == OK)
9283 	{
9284 	    if (*varname == '&')
9285 	    {
9286 		long	numval;
9287 		char_u	*strval;
9288 		int		error = FALSE;
9289 
9290 		++varname;
9291 		numval = (long)tv_get_number_chk(varp, &error);
9292 		strval = tv_get_string_buf_chk(varp, nbuf);
9293 		if (!error && strval != NULL)
9294 		    set_option_value(varname, numval, strval, OPT_LOCAL);
9295 	    }
9296 	    else
9297 	    {
9298 		winvarname = alloc(STRLEN(varname) + 3);
9299 		if (winvarname != NULL)
9300 		{
9301 		    STRCPY(winvarname, "w:");
9302 		    STRCPY(winvarname + 2, varname);
9303 		    set_var(winvarname, varp, TRUE);
9304 		    vim_free(winvarname);
9305 		}
9306 	    }
9307 	}
9308 	if (need_switch_win)
9309 	    restore_win(save_curwin, save_curtab, TRUE);
9310     }
9311 }
9312 
9313 /*
9314  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
9315  * "arg" points to the "&" or '+' when called, to "option" when returning.
9316  * Returns NULL when no option name found.  Otherwise pointer to the char
9317  * after the option name.
9318  */
9319     static char_u *
9320 find_option_end(char_u **arg, int *opt_flags)
9321 {
9322     char_u	*p = *arg;
9323 
9324     ++p;
9325     if (*p == 'g' && p[1] == ':')
9326     {
9327 	*opt_flags = OPT_GLOBAL;
9328 	p += 2;
9329     }
9330     else if (*p == 'l' && p[1] == ':')
9331     {
9332 	*opt_flags = OPT_LOCAL;
9333 	p += 2;
9334     }
9335     else
9336 	*opt_flags = 0;
9337 
9338     if (!ASCII_ISALPHA(*p))
9339 	return NULL;
9340     *arg = p;
9341 
9342     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
9343 	p += 4;	    /* termcap option */
9344     else
9345 	while (ASCII_ISALPHA(*p))
9346 	    ++p;
9347     return p;
9348 }
9349 
9350 /*
9351  * Return the autoload script name for a function or variable name.
9352  * Returns NULL when out of memory.
9353  * Caller must make sure that "name" contains AUTOLOAD_CHAR.
9354  */
9355     char_u *
9356 autoload_name(char_u *name)
9357 {
9358     char_u	*p, *q = NULL;
9359     char_u	*scriptname;
9360 
9361     // Get the script file name: replace '#' with '/', append ".vim".
9362     scriptname = alloc(STRLEN(name) + 14);
9363     if (scriptname == NULL)
9364 	return FALSE;
9365     STRCPY(scriptname, "autoload/");
9366     STRCAT(scriptname, name);
9367     for (p = scriptname + 9; (p = vim_strchr(p, AUTOLOAD_CHAR)) != NULL;
9368 								    q = p, ++p)
9369 	*p = '/';
9370     STRCPY(q, ".vim");
9371     return scriptname;
9372 }
9373 
9374 /*
9375  * If "name" has a package name try autoloading the script for it.
9376  * Return TRUE if a package was loaded.
9377  */
9378     int
9379 script_autoload(
9380     char_u	*name,
9381     int		reload)	    /* load script again when already loaded */
9382 {
9383     char_u	*p;
9384     char_u	*scriptname, *tofree;
9385     int		ret = FALSE;
9386     int		i;
9387 
9388     /* If there is no '#' after name[0] there is no package name. */
9389     p = vim_strchr(name, AUTOLOAD_CHAR);
9390     if (p == NULL || p == name)
9391 	return FALSE;
9392 
9393     tofree = scriptname = autoload_name(name);
9394 
9395     /* Find the name in the list of previously loaded package names.  Skip
9396      * "autoload/", it's always the same. */
9397     for (i = 0; i < ga_loaded.ga_len; ++i)
9398 	if (STRCMP(((char_u **)ga_loaded.ga_data)[i] + 9, scriptname + 9) == 0)
9399 	    break;
9400     if (!reload && i < ga_loaded.ga_len)
9401 	ret = FALSE;	    /* was loaded already */
9402     else
9403     {
9404 	/* Remember the name if it wasn't loaded already. */
9405 	if (i == ga_loaded.ga_len && ga_grow(&ga_loaded, 1) == OK)
9406 	{
9407 	    ((char_u **)ga_loaded.ga_data)[ga_loaded.ga_len++] = scriptname;
9408 	    tofree = NULL;
9409 	}
9410 
9411 	/* Try loading the package from $VIMRUNTIME/autoload/<name>.vim */
9412 	if (source_runtime(scriptname, 0) == OK)
9413 	    ret = TRUE;
9414     }
9415 
9416     vim_free(tofree);
9417     return ret;
9418 }
9419 
9420 /*
9421  * Display script name where an item was last set.
9422  * Should only be invoked when 'verbose' is non-zero.
9423  */
9424     void
9425 last_set_msg(sctx_T script_ctx)
9426 {
9427     char_u *p;
9428 
9429     if (script_ctx.sc_sid != 0)
9430     {
9431 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
9432 	if (p != NULL)
9433 	{
9434 	    verbose_enter();
9435 	    msg_puts(_("\n\tLast set from "));
9436 	    msg_puts((char *)p);
9437 	    if (script_ctx.sc_lnum > 0)
9438 	    {
9439 		msg_puts(_(" line "));
9440 		msg_outnum((long)script_ctx.sc_lnum);
9441 	    }
9442 	    verbose_leave();
9443 	    vim_free(p);
9444 	}
9445     }
9446 }
9447 
9448 /*
9449  * reset v:option_new, v:option_old, v:option_oldlocal, v:option_oldglobal,
9450  * v:option_type, and v:option_command.
9451  */
9452     void
9453 reset_v_option_vars(void)
9454 {
9455     set_vim_var_string(VV_OPTION_NEW,  NULL, -1);
9456     set_vim_var_string(VV_OPTION_OLD,  NULL, -1);
9457     set_vim_var_string(VV_OPTION_OLDLOCAL, NULL, -1);
9458     set_vim_var_string(VV_OPTION_OLDGLOBAL, NULL, -1);
9459     set_vim_var_string(VV_OPTION_TYPE, NULL, -1);
9460     set_vim_var_string(VV_OPTION_COMMAND, NULL, -1);
9461 }
9462 
9463 /*
9464  * Add an assert error to v:errors.
9465  */
9466     void
9467 assert_error(garray_T *gap)
9468 {
9469     struct vimvar   *vp = &vimvars[VV_ERRORS];
9470 
9471     if (vp->vv_type != VAR_LIST || vimvars[VV_ERRORS].vv_list == NULL)
9472 	/* Make sure v:errors is a list. */
9473 	set_vim_var_list(VV_ERRORS, list_alloc());
9474     list_append_string(vimvars[VV_ERRORS].vv_list, gap->ga_data, gap->ga_len);
9475 }
9476 /*
9477  * Compare "typ1" and "typ2".  Put the result in "typ1".
9478  */
9479     int
9480 typval_compare(
9481     typval_T	*typ1,   /* first operand */
9482     typval_T	*typ2,   /* second operand */
9483     exptype_T	type,    /* operator */
9484     int		type_is, /* TRUE for "is" and "isnot" */
9485     int		ic)      /* ignore case */
9486 {
9487     int		i;
9488     varnumber_T	n1, n2;
9489     char_u	*s1, *s2;
9490     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
9491 
9492     if (type_is && typ1->v_type != typ2->v_type)
9493     {
9494 	/* For "is" a different type always means FALSE, for "notis"
9495 	    * it means TRUE. */
9496 	n1 = (type == TYPE_NEQUAL);
9497     }
9498     else if (typ1->v_type == VAR_BLOB || typ2->v_type == VAR_BLOB)
9499     {
9500 	if (type_is)
9501 	{
9502 	    n1 = (typ1->v_type == typ2->v_type
9503 			    && typ1->vval.v_blob == typ2->vval.v_blob);
9504 	    if (type == TYPE_NEQUAL)
9505 		n1 = !n1;
9506 	}
9507 	else if (typ1->v_type != typ2->v_type
9508 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
9509 	{
9510 	    if (typ1->v_type != typ2->v_type)
9511 		emsg(_("E977: Can only compare Blob with Blob"));
9512 	    else
9513 		emsg(_(e_invalblob));
9514 	    clear_tv(typ1);
9515 	    return FAIL;
9516 	}
9517 	else
9518 	{
9519 	    // Compare two Blobs for being equal or unequal.
9520 	    n1 = blob_equal(typ1->vval.v_blob, typ2->vval.v_blob);
9521 	    if (type == TYPE_NEQUAL)
9522 		n1 = !n1;
9523 	}
9524     }
9525     else if (typ1->v_type == VAR_LIST || typ2->v_type == VAR_LIST)
9526     {
9527 	if (type_is)
9528 	{
9529 	    n1 = (typ1->v_type == typ2->v_type
9530 			    && typ1->vval.v_list == typ2->vval.v_list);
9531 	    if (type == TYPE_NEQUAL)
9532 		n1 = !n1;
9533 	}
9534 	else if (typ1->v_type != typ2->v_type
9535 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
9536 	{
9537 	    if (typ1->v_type != typ2->v_type)
9538 		emsg(_("E691: Can only compare List with List"));
9539 	    else
9540 		emsg(_("E692: Invalid operation for List"));
9541 	    clear_tv(typ1);
9542 	    return FAIL;
9543 	}
9544 	else
9545 	{
9546 	    /* Compare two Lists for being equal or unequal. */
9547 	    n1 = list_equal(typ1->vval.v_list, typ2->vval.v_list,
9548 							    ic, FALSE);
9549 	    if (type == TYPE_NEQUAL)
9550 		n1 = !n1;
9551 	}
9552     }
9553 
9554     else if (typ1->v_type == VAR_DICT || typ2->v_type == VAR_DICT)
9555     {
9556 	if (type_is)
9557 	{
9558 	    n1 = (typ1->v_type == typ2->v_type
9559 			    && typ1->vval.v_dict == typ2->vval.v_dict);
9560 	    if (type == TYPE_NEQUAL)
9561 		n1 = !n1;
9562 	}
9563 	else if (typ1->v_type != typ2->v_type
9564 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
9565 	{
9566 	    if (typ1->v_type != typ2->v_type)
9567 		emsg(_("E735: Can only compare Dictionary with Dictionary"));
9568 	    else
9569 		emsg(_("E736: Invalid operation for Dictionary"));
9570 	    clear_tv(typ1);
9571 	    return FAIL;
9572 	}
9573 	else
9574 	{
9575 	    /* Compare two Dictionaries for being equal or unequal. */
9576 	    n1 = dict_equal(typ1->vval.v_dict, typ2->vval.v_dict,
9577 							    ic, FALSE);
9578 	    if (type == TYPE_NEQUAL)
9579 		n1 = !n1;
9580 	}
9581     }
9582 
9583     else if (typ1->v_type == VAR_FUNC || typ2->v_type == VAR_FUNC
9584 	|| typ1->v_type == VAR_PARTIAL || typ2->v_type == VAR_PARTIAL)
9585     {
9586 	if (type != TYPE_EQUAL && type != TYPE_NEQUAL)
9587 	{
9588 	    emsg(_("E694: Invalid operation for Funcrefs"));
9589 	    clear_tv(typ1);
9590 	    return FAIL;
9591 	}
9592 	if ((typ1->v_type == VAR_PARTIAL
9593 					&& typ1->vval.v_partial == NULL)
9594 		|| (typ2->v_type == VAR_PARTIAL
9595 					&& typ2->vval.v_partial == NULL))
9596 	    /* when a partial is NULL assume not equal */
9597 	    n1 = FALSE;
9598 	else if (type_is)
9599 	{
9600 	    if (typ1->v_type == VAR_FUNC && typ2->v_type == VAR_FUNC)
9601 		/* strings are considered the same if their value is
9602 		    * the same */
9603 		n1 = tv_equal(typ1, typ2, ic, FALSE);
9604 	    else if (typ1->v_type == VAR_PARTIAL
9605 					&& typ2->v_type == VAR_PARTIAL)
9606 		n1 = (typ1->vval.v_partial == typ2->vval.v_partial);
9607 	    else
9608 		n1 = FALSE;
9609 	}
9610 	else
9611 	    n1 = tv_equal(typ1, typ2, ic, FALSE);
9612 	if (type == TYPE_NEQUAL)
9613 	    n1 = !n1;
9614     }
9615 
9616 #ifdef FEAT_FLOAT
9617     /*
9618 	* If one of the two variables is a float, compare as a float.
9619 	* When using "=~" or "!~", always compare as string.
9620 	*/
9621     else if ((typ1->v_type == VAR_FLOAT || typ2->v_type == VAR_FLOAT)
9622 	    && type != TYPE_MATCH && type != TYPE_NOMATCH)
9623     {
9624 	float_T f1, f2;
9625 
9626 	f1 = tv_get_float(typ1);
9627 	f2 = tv_get_float(typ2);
9628 	n1 = FALSE;
9629 	switch (type)
9630 	{
9631 	    case TYPE_EQUAL:    n1 = (f1 == f2); break;
9632 	    case TYPE_NEQUAL:   n1 = (f1 != f2); break;
9633 	    case TYPE_GREATER:  n1 = (f1 > f2); break;
9634 	    case TYPE_GEQUAL:   n1 = (f1 >= f2); break;
9635 	    case TYPE_SMALLER:  n1 = (f1 < f2); break;
9636 	    case TYPE_SEQUAL:   n1 = (f1 <= f2); break;
9637 	    case TYPE_UNKNOWN:
9638 	    case TYPE_MATCH:
9639 	    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
9640 	}
9641     }
9642 #endif
9643 
9644     /*
9645 	* If one of the two variables is a number, compare as a number.
9646 	* When using "=~" or "!~", always compare as string.
9647 	*/
9648     else if ((typ1->v_type == VAR_NUMBER || typ2->v_type == VAR_NUMBER)
9649 	    && type != TYPE_MATCH && type != TYPE_NOMATCH)
9650     {
9651 	n1 = tv_get_number(typ1);
9652 	n2 = tv_get_number(typ2);
9653 	switch (type)
9654 	{
9655 	    case TYPE_EQUAL:    n1 = (n1 == n2); break;
9656 	    case TYPE_NEQUAL:   n1 = (n1 != n2); break;
9657 	    case TYPE_GREATER:  n1 = (n1 > n2); break;
9658 	    case TYPE_GEQUAL:   n1 = (n1 >= n2); break;
9659 	    case TYPE_SMALLER:  n1 = (n1 < n2); break;
9660 	    case TYPE_SEQUAL:   n1 = (n1 <= n2); break;
9661 	    case TYPE_UNKNOWN:
9662 	    case TYPE_MATCH:
9663 	    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
9664 	}
9665     }
9666     else
9667     {
9668 	s1 = tv_get_string_buf(typ1, buf1);
9669 	s2 = tv_get_string_buf(typ2, buf2);
9670 	if (type != TYPE_MATCH && type != TYPE_NOMATCH)
9671 	    i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
9672 	else
9673 	    i = 0;
9674 	n1 = FALSE;
9675 	switch (type)
9676 	{
9677 	    case TYPE_EQUAL:    n1 = (i == 0); break;
9678 	    case TYPE_NEQUAL:   n1 = (i != 0); break;
9679 	    case TYPE_GREATER:  n1 = (i > 0); break;
9680 	    case TYPE_GEQUAL:   n1 = (i >= 0); break;
9681 	    case TYPE_SMALLER:  n1 = (i < 0); break;
9682 	    case TYPE_SEQUAL:   n1 = (i <= 0); break;
9683 
9684 	    case TYPE_MATCH:
9685 	    case TYPE_NOMATCH:
9686 		    n1 = pattern_match(s2, s1, ic);
9687 		    if (type == TYPE_NOMATCH)
9688 			n1 = !n1;
9689 		    break;
9690 
9691 	    case TYPE_UNKNOWN:  break;  /* avoid gcc warning */
9692 	}
9693     }
9694     clear_tv(typ1);
9695     typ1->v_type = VAR_NUMBER;
9696     typ1->vval.v_number = n1;
9697 
9698     return OK;
9699 }
9700 
9701     char_u *
9702 typval_tostring(typval_T *arg)
9703 {
9704     char_u	*tofree;
9705     char_u	numbuf[NUMBUFLEN];
9706     char_u	*ret = NULL;
9707 
9708     if (arg == NULL)
9709 	return vim_strsave((char_u *)"(does not exist)");
9710     ret = tv2string(arg, &tofree, numbuf, 0);
9711     /* Make a copy if we have a value but it's not in allocated memory. */
9712     if (ret != NULL && tofree == NULL)
9713 	ret = vim_strsave(ret);
9714     return ret;
9715 }
9716 
9717     int
9718 var_exists(char_u *var)
9719 {
9720     char_u	*name;
9721     char_u	*tofree;
9722     typval_T    tv;
9723     int		len = 0;
9724     int		n = FALSE;
9725 
9726     /* get_name_len() takes care of expanding curly braces */
9727     name = var;
9728     len = get_name_len(&var, &tofree, TRUE, FALSE);
9729     if (len > 0)
9730     {
9731 	if (tofree != NULL)
9732 	    name = tofree;
9733 	n = (get_var_tv(name, len, &tv, NULL, FALSE, TRUE) == OK);
9734 	if (n)
9735 	{
9736 	    /* handle d.key, l[idx], f(expr) */
9737 	    n = (handle_subscript(&var, &tv, TRUE, FALSE) == OK);
9738 	    if (n)
9739 		clear_tv(&tv);
9740 	}
9741     }
9742     if (*var != NUL)
9743 	n = FALSE;
9744 
9745     vim_free(tofree);
9746     return n;
9747 }
9748 
9749 #endif /* FEAT_EVAL */
9750 
9751 
9752 #if defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) || defined(PROTO)
9753 
9754 #ifdef MSWIN
9755 /*
9756  * Functions for ":8" filename modifier: get 8.3 version of a filename.
9757  */
9758 
9759 /*
9760  * Get the short path (8.3) for the filename in "fnamep".
9761  * Only works for a valid file name.
9762  * When the path gets longer "fnamep" is changed and the allocated buffer
9763  * is put in "bufp".
9764  * *fnamelen is the length of "fnamep" and set to 0 for a nonexistent path.
9765  * Returns OK on success, FAIL on failure.
9766  */
9767     static int
9768 get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen)
9769 {
9770     int		l, len;
9771     char_u	*newbuf;
9772 
9773     len = *fnamelen;
9774     l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, len);
9775     if (l > len - 1)
9776     {
9777 	/* If that doesn't work (not enough space), then save the string
9778 	 * and try again with a new buffer big enough. */
9779 	newbuf = vim_strnsave(*fnamep, l);
9780 	if (newbuf == NULL)
9781 	    return FAIL;
9782 
9783 	vim_free(*bufp);
9784 	*fnamep = *bufp = newbuf;
9785 
9786 	/* Really should always succeed, as the buffer is big enough. */
9787 	l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, l+1);
9788     }
9789 
9790     *fnamelen = l;
9791     return OK;
9792 }
9793 
9794 /*
9795  * Get the short path (8.3) for the filename in "fname". The converted
9796  * path is returned in "bufp".
9797  *
9798  * Some of the directories specified in "fname" may not exist. This function
9799  * will shorten the existing directories at the beginning of the path and then
9800  * append the remaining non-existing path.
9801  *
9802  * fname - Pointer to the filename to shorten.  On return, contains the
9803  *	   pointer to the shortened pathname
9804  * bufp -  Pointer to an allocated buffer for the filename.
9805  * fnamelen - Length of the filename pointed to by fname
9806  *
9807  * Returns OK on success (or nothing done) and FAIL on failure (out of memory).
9808  */
9809     static int
9810 shortpath_for_invalid_fname(
9811     char_u	**fname,
9812     char_u	**bufp,
9813     int		*fnamelen)
9814 {
9815     char_u	*short_fname, *save_fname, *pbuf_unused;
9816     char_u	*endp, *save_endp;
9817     char_u	ch;
9818     int		old_len, len;
9819     int		new_len, sfx_len;
9820     int		retval = OK;
9821 
9822     /* Make a copy */
9823     old_len = *fnamelen;
9824     save_fname = vim_strnsave(*fname, old_len);
9825     pbuf_unused = NULL;
9826     short_fname = NULL;
9827 
9828     endp = save_fname + old_len - 1; /* Find the end of the copy */
9829     save_endp = endp;
9830 
9831     /*
9832      * Try shortening the supplied path till it succeeds by removing one
9833      * directory at a time from the tail of the path.
9834      */
9835     len = 0;
9836     for (;;)
9837     {
9838 	/* go back one path-separator */
9839 	while (endp > save_fname && !after_pathsep(save_fname, endp + 1))
9840 	    --endp;
9841 	if (endp <= save_fname)
9842 	    break;		/* processed the complete path */
9843 
9844 	/*
9845 	 * Replace the path separator with a NUL and try to shorten the
9846 	 * resulting path.
9847 	 */
9848 	ch = *endp;
9849 	*endp = 0;
9850 	short_fname = save_fname;
9851 	len = (int)STRLEN(short_fname) + 1;
9852 	if (get_short_pathname(&short_fname, &pbuf_unused, &len) == FAIL)
9853 	{
9854 	    retval = FAIL;
9855 	    goto theend;
9856 	}
9857 	*endp = ch;	/* preserve the string */
9858 
9859 	if (len > 0)
9860 	    break;	/* successfully shortened the path */
9861 
9862 	/* failed to shorten the path. Skip the path separator */
9863 	--endp;
9864     }
9865 
9866     if (len > 0)
9867     {
9868 	/*
9869 	 * Succeeded in shortening the path. Now concatenate the shortened
9870 	 * path with the remaining path at the tail.
9871 	 */
9872 
9873 	/* Compute the length of the new path. */
9874 	sfx_len = (int)(save_endp - endp) + 1;
9875 	new_len = len + sfx_len;
9876 
9877 	*fnamelen = new_len;
9878 	vim_free(*bufp);
9879 	if (new_len > old_len)
9880 	{
9881 	    /* There is not enough space in the currently allocated string,
9882 	     * copy it to a buffer big enough. */
9883 	    *fname = *bufp = vim_strnsave(short_fname, new_len);
9884 	    if (*fname == NULL)
9885 	    {
9886 		retval = FAIL;
9887 		goto theend;
9888 	    }
9889 	}
9890 	else
9891 	{
9892 	    /* Transfer short_fname to the main buffer (it's big enough),
9893 	     * unless get_short_pathname() did its work in-place. */
9894 	    *fname = *bufp = save_fname;
9895 	    if (short_fname != save_fname)
9896 		vim_strncpy(save_fname, short_fname, len);
9897 	    save_fname = NULL;
9898 	}
9899 
9900 	/* concat the not-shortened part of the path */
9901 	vim_strncpy(*fname + len, endp, sfx_len);
9902 	(*fname)[new_len] = NUL;
9903     }
9904 
9905 theend:
9906     vim_free(pbuf_unused);
9907     vim_free(save_fname);
9908 
9909     return retval;
9910 }
9911 
9912 /*
9913  * Get a pathname for a partial path.
9914  * Returns OK for success, FAIL for failure.
9915  */
9916     static int
9917 shortpath_for_partial(
9918     char_u	**fnamep,
9919     char_u	**bufp,
9920     int		*fnamelen)
9921 {
9922     int		sepcount, len, tflen;
9923     char_u	*p;
9924     char_u	*pbuf, *tfname;
9925     int		hasTilde;
9926 
9927     /* Count up the path separators from the RHS.. so we know which part
9928      * of the path to return. */
9929     sepcount = 0;
9930     for (p = *fnamep; p < *fnamep + *fnamelen; MB_PTR_ADV(p))
9931 	if (vim_ispathsep(*p))
9932 	    ++sepcount;
9933 
9934     /* Need full path first (use expand_env() to remove a "~/") */
9935     hasTilde = (**fnamep == '~');
9936     if (hasTilde)
9937 	pbuf = tfname = expand_env_save(*fnamep);
9938     else
9939 	pbuf = tfname = FullName_save(*fnamep, FALSE);
9940 
9941     len = tflen = (int)STRLEN(tfname);
9942 
9943     if (get_short_pathname(&tfname, &pbuf, &len) == FAIL)
9944 	return FAIL;
9945 
9946     if (len == 0)
9947     {
9948 	/* Don't have a valid filename, so shorten the rest of the
9949 	 * path if we can. This CAN give us invalid 8.3 filenames, but
9950 	 * there's not a lot of point in guessing what it might be.
9951 	 */
9952 	len = tflen;
9953 	if (shortpath_for_invalid_fname(&tfname, &pbuf, &len) == FAIL)
9954 	    return FAIL;
9955     }
9956 
9957     /* Count the paths backward to find the beginning of the desired string. */
9958     for (p = tfname + len - 1; p >= tfname; --p)
9959     {
9960 	if (has_mbyte)
9961 	    p -= mb_head_off(tfname, p);
9962 	if (vim_ispathsep(*p))
9963 	{
9964 	    if (sepcount == 0 || (hasTilde && sepcount == 1))
9965 		break;
9966 	    else
9967 		sepcount --;
9968 	}
9969     }
9970     if (hasTilde)
9971     {
9972 	--p;
9973 	if (p >= tfname)
9974 	    *p = '~';
9975 	else
9976 	    return FAIL;
9977     }
9978     else
9979 	++p;
9980 
9981     /* Copy in the string - p indexes into tfname - allocated at pbuf */
9982     vim_free(*bufp);
9983     *fnamelen = (int)STRLEN(p);
9984     *bufp = pbuf;
9985     *fnamep = p;
9986 
9987     return OK;
9988 }
9989 #endif // MSWIN
9990 
9991 /*
9992  * Adjust a filename, according to a string of modifiers.
9993  * *fnamep must be NUL terminated when called.  When returning, the length is
9994  * determined by *fnamelen.
9995  * Returns VALID_ flags or -1 for failure.
9996  * When there is an error, *fnamep is set to NULL.
9997  */
9998     int
9999 modify_fname(
10000     char_u	*src,		// string with modifiers
10001     int		tilde_file,	// "~" is a file name, not $HOME
10002     int		*usedlen,	// characters after src that are used
10003     char_u	**fnamep,	// file name so far
10004     char_u	**bufp,		// buffer for allocated file name or NULL
10005     int		*fnamelen)	// length of fnamep
10006 {
10007     int		valid = 0;
10008     char_u	*tail;
10009     char_u	*s, *p, *pbuf;
10010     char_u	dirname[MAXPATHL];
10011     int		c;
10012     int		has_fullname = 0;
10013 #ifdef MSWIN
10014     char_u	*fname_start = *fnamep;
10015     int		has_shortname = 0;
10016 #endif
10017 
10018 repeat:
10019     /* ":p" - full path/file_name */
10020     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'p')
10021     {
10022 	has_fullname = 1;
10023 
10024 	valid |= VALID_PATH;
10025 	*usedlen += 2;
10026 
10027 	/* Expand "~/path" for all systems and "~user/path" for Unix and VMS */
10028 	if ((*fnamep)[0] == '~'
10029 #if !defined(UNIX) && !(defined(VMS) && defined(USER_HOME))
10030 		&& ((*fnamep)[1] == '/'
10031 # ifdef BACKSLASH_IN_FILENAME
10032 		    || (*fnamep)[1] == '\\'
10033 # endif
10034 		    || (*fnamep)[1] == NUL)
10035 #endif
10036 		&& !(tilde_file && (*fnamep)[1] == NUL)
10037 	   )
10038 	{
10039 	    *fnamep = expand_env_save(*fnamep);
10040 	    vim_free(*bufp);	/* free any allocated file name */
10041 	    *bufp = *fnamep;
10042 	    if (*fnamep == NULL)
10043 		return -1;
10044 	}
10045 
10046 	/* When "/." or "/.." is used: force expansion to get rid of it. */
10047 	for (p = *fnamep; *p != NUL; MB_PTR_ADV(p))
10048 	{
10049 	    if (vim_ispathsep(*p)
10050 		    && p[1] == '.'
10051 		    && (p[2] == NUL
10052 			|| vim_ispathsep(p[2])
10053 			|| (p[2] == '.'
10054 			    && (p[3] == NUL || vim_ispathsep(p[3])))))
10055 		break;
10056 	}
10057 
10058 	/* FullName_save() is slow, don't use it when not needed. */
10059 	if (*p != NUL || !vim_isAbsName(*fnamep))
10060 	{
10061 	    *fnamep = FullName_save(*fnamep, *p != NUL);
10062 	    vim_free(*bufp);	/* free any allocated file name */
10063 	    *bufp = *fnamep;
10064 	    if (*fnamep == NULL)
10065 		return -1;
10066 	}
10067 
10068 #ifdef MSWIN
10069 # if _WIN32_WINNT >= 0x0500
10070 	if (vim_strchr(*fnamep, '~') != NULL)
10071 	{
10072 	    // Expand 8.3 filename to full path.  Needed to make sure the same
10073 	    // file does not have two different names.
10074 	    // Note: problem does not occur if _WIN32_WINNT < 0x0500.
10075 	    WCHAR *wfname = enc_to_utf16(*fnamep, NULL);
10076 	    WCHAR buf[_MAX_PATH];
10077 
10078 	    if (wfname != NULL)
10079 	    {
10080 		if (GetLongPathNameW(wfname, buf, _MAX_PATH))
10081 		{
10082 		    char_u *p = utf16_to_enc(buf, NULL);
10083 
10084 		    if (p != NULL)
10085 		    {
10086 			vim_free(*bufp);    // free any allocated file name
10087 			*bufp = *fnamep = p;
10088 		    }
10089 		}
10090 		vim_free(wfname);
10091 	    }
10092 	}
10093 # endif
10094 #endif
10095 	/* Append a path separator to a directory. */
10096 	if (mch_isdir(*fnamep))
10097 	{
10098 	    /* Make room for one or two extra characters. */
10099 	    *fnamep = vim_strnsave(*fnamep, (int)STRLEN(*fnamep) + 2);
10100 	    vim_free(*bufp);	/* free any allocated file name */
10101 	    *bufp = *fnamep;
10102 	    if (*fnamep == NULL)
10103 		return -1;
10104 	    add_pathsep(*fnamep);
10105 	}
10106     }
10107 
10108     /* ":." - path relative to the current directory */
10109     /* ":~" - path relative to the home directory */
10110     /* ":8" - shortname path - postponed till after */
10111     while (src[*usedlen] == ':'
10112 		  && ((c = src[*usedlen + 1]) == '.' || c == '~' || c == '8'))
10113     {
10114 	*usedlen += 2;
10115 	if (c == '8')
10116 	{
10117 #ifdef MSWIN
10118 	    has_shortname = 1; /* Postpone this. */
10119 #endif
10120 	    continue;
10121 	}
10122 	pbuf = NULL;
10123 	/* Need full path first (use expand_env() to remove a "~/") */
10124 	if (!has_fullname)
10125 	{
10126 	    if (c == '.' && **fnamep == '~')
10127 		p = pbuf = expand_env_save(*fnamep);
10128 	    else
10129 		p = pbuf = FullName_save(*fnamep, FALSE);
10130 	}
10131 	else
10132 	    p = *fnamep;
10133 
10134 	has_fullname = 0;
10135 
10136 	if (p != NULL)
10137 	{
10138 	    if (c == '.')
10139 	    {
10140 		mch_dirname(dirname, MAXPATHL);
10141 		s = shorten_fname(p, dirname);
10142 		if (s != NULL)
10143 		{
10144 		    *fnamep = s;
10145 		    if (pbuf != NULL)
10146 		    {
10147 			vim_free(*bufp);   /* free any allocated file name */
10148 			*bufp = pbuf;
10149 			pbuf = NULL;
10150 		    }
10151 		}
10152 	    }
10153 	    else
10154 	    {
10155 		home_replace(NULL, p, dirname, MAXPATHL, TRUE);
10156 		/* Only replace it when it starts with '~' */
10157 		if (*dirname == '~')
10158 		{
10159 		    s = vim_strsave(dirname);
10160 		    if (s != NULL)
10161 		    {
10162 			*fnamep = s;
10163 			vim_free(*bufp);
10164 			*bufp = s;
10165 		    }
10166 		}
10167 	    }
10168 	    vim_free(pbuf);
10169 	}
10170     }
10171 
10172     tail = gettail(*fnamep);
10173     *fnamelen = (int)STRLEN(*fnamep);
10174 
10175     /* ":h" - head, remove "/file_name", can be repeated  */
10176     /* Don't remove the first "/" or "c:\" */
10177     while (src[*usedlen] == ':' && src[*usedlen + 1] == 'h')
10178     {
10179 	valid |= VALID_HEAD;
10180 	*usedlen += 2;
10181 	s = get_past_head(*fnamep);
10182 	while (tail > s && after_pathsep(s, tail))
10183 	    MB_PTR_BACK(*fnamep, tail);
10184 	*fnamelen = (int)(tail - *fnamep);
10185 #ifdef VMS
10186 	if (*fnamelen > 0)
10187 	    *fnamelen += 1; /* the path separator is part of the path */
10188 #endif
10189 	if (*fnamelen == 0)
10190 	{
10191 	    /* Result is empty.  Turn it into "." to make ":cd %:h" work. */
10192 	    p = vim_strsave((char_u *)".");
10193 	    if (p == NULL)
10194 		return -1;
10195 	    vim_free(*bufp);
10196 	    *bufp = *fnamep = tail = p;
10197 	    *fnamelen = 1;
10198 	}
10199 	else
10200 	{
10201 	    while (tail > s && !after_pathsep(s, tail))
10202 		MB_PTR_BACK(*fnamep, tail);
10203 	}
10204     }
10205 
10206     /* ":8" - shortname  */
10207     if (src[*usedlen] == ':' && src[*usedlen + 1] == '8')
10208     {
10209 	*usedlen += 2;
10210 #ifdef MSWIN
10211 	has_shortname = 1;
10212 #endif
10213     }
10214 
10215 #ifdef MSWIN
10216     /*
10217      * Handle ":8" after we have done 'heads' and before we do 'tails'.
10218      */
10219     if (has_shortname)
10220     {
10221 	/* Copy the string if it is shortened by :h and when it wasn't copied
10222 	 * yet, because we are going to change it in place.  Avoids changing
10223 	 * the buffer name for "%:8". */
10224 	if (*fnamelen < (int)STRLEN(*fnamep) || *fnamep == fname_start)
10225 	{
10226 	    p = vim_strnsave(*fnamep, *fnamelen);
10227 	    if (p == NULL)
10228 		return -1;
10229 	    vim_free(*bufp);
10230 	    *bufp = *fnamep = p;
10231 	}
10232 
10233 	/* Split into two implementations - makes it easier.  First is where
10234 	 * there isn't a full name already, second is where there is. */
10235 	if (!has_fullname && !vim_isAbsName(*fnamep))
10236 	{
10237 	    if (shortpath_for_partial(fnamep, bufp, fnamelen) == FAIL)
10238 		return -1;
10239 	}
10240 	else
10241 	{
10242 	    int		l = *fnamelen;
10243 
10244 	    /* Simple case, already have the full-name.
10245 	     * Nearly always shorter, so try first time. */
10246 	    if (get_short_pathname(fnamep, bufp, &l) == FAIL)
10247 		return -1;
10248 
10249 	    if (l == 0)
10250 	    {
10251 		/* Couldn't find the filename, search the paths. */
10252 		l = *fnamelen;
10253 		if (shortpath_for_invalid_fname(fnamep, bufp, &l) == FAIL)
10254 		    return -1;
10255 	    }
10256 	    *fnamelen = l;
10257 	}
10258     }
10259 #endif // MSWIN
10260 
10261     /* ":t" - tail, just the basename */
10262     if (src[*usedlen] == ':' && src[*usedlen + 1] == 't')
10263     {
10264 	*usedlen += 2;
10265 	*fnamelen -= (int)(tail - *fnamep);
10266 	*fnamep = tail;
10267     }
10268 
10269     /* ":e" - extension, can be repeated */
10270     /* ":r" - root, without extension, can be repeated */
10271     while (src[*usedlen] == ':'
10272 	    && (src[*usedlen + 1] == 'e' || src[*usedlen + 1] == 'r'))
10273     {
10274 	/* find a '.' in the tail:
10275 	 * - for second :e: before the current fname
10276 	 * - otherwise: The last '.'
10277 	 */
10278 	if (src[*usedlen + 1] == 'e' && *fnamep > tail)
10279 	    s = *fnamep - 2;
10280 	else
10281 	    s = *fnamep + *fnamelen - 1;
10282 	for ( ; s > tail; --s)
10283 	    if (s[0] == '.')
10284 		break;
10285 	if (src[*usedlen + 1] == 'e')		/* :e */
10286 	{
10287 	    if (s > tail)
10288 	    {
10289 		*fnamelen += (int)(*fnamep - (s + 1));
10290 		*fnamep = s + 1;
10291 #ifdef VMS
10292 		/* cut version from the extension */
10293 		s = *fnamep + *fnamelen - 1;
10294 		for ( ; s > *fnamep; --s)
10295 		    if (s[0] == ';')
10296 			break;
10297 		if (s > *fnamep)
10298 		    *fnamelen = s - *fnamep;
10299 #endif
10300 	    }
10301 	    else if (*fnamep <= tail)
10302 		*fnamelen = 0;
10303 	}
10304 	else				/* :r */
10305 	{
10306 	    if (s > tail)	/* remove one extension */
10307 		*fnamelen = (int)(s - *fnamep);
10308 	}
10309 	*usedlen += 2;
10310     }
10311 
10312     /* ":s?pat?foo?" - substitute */
10313     /* ":gs?pat?foo?" - global substitute */
10314     if (src[*usedlen] == ':'
10315 	    && (src[*usedlen + 1] == 's'
10316 		|| (src[*usedlen + 1] == 'g' && src[*usedlen + 2] == 's')))
10317     {
10318 	char_u	    *str;
10319 	char_u	    *pat;
10320 	char_u	    *sub;
10321 	int	    sep;
10322 	char_u	    *flags;
10323 	int	    didit = FALSE;
10324 
10325 	flags = (char_u *)"";
10326 	s = src + *usedlen + 2;
10327 	if (src[*usedlen + 1] == 'g')
10328 	{
10329 	    flags = (char_u *)"g";
10330 	    ++s;
10331 	}
10332 
10333 	sep = *s++;
10334 	if (sep)
10335 	{
10336 	    /* find end of pattern */
10337 	    p = vim_strchr(s, sep);
10338 	    if (p != NULL)
10339 	    {
10340 		pat = vim_strnsave(s, (int)(p - s));
10341 		if (pat != NULL)
10342 		{
10343 		    s = p + 1;
10344 		    /* find end of substitution */
10345 		    p = vim_strchr(s, sep);
10346 		    if (p != NULL)
10347 		    {
10348 			sub = vim_strnsave(s, (int)(p - s));
10349 			str = vim_strnsave(*fnamep, *fnamelen);
10350 			if (sub != NULL && str != NULL)
10351 			{
10352 			    *usedlen = (int)(p + 1 - src);
10353 			    s = do_string_sub(str, pat, sub, NULL, flags);
10354 			    if (s != NULL)
10355 			    {
10356 				*fnamep = s;
10357 				*fnamelen = (int)STRLEN(s);
10358 				vim_free(*bufp);
10359 				*bufp = s;
10360 				didit = TRUE;
10361 			    }
10362 			}
10363 			vim_free(sub);
10364 			vim_free(str);
10365 		    }
10366 		    vim_free(pat);
10367 		}
10368 	    }
10369 	    /* after using ":s", repeat all the modifiers */
10370 	    if (didit)
10371 		goto repeat;
10372 	}
10373     }
10374 
10375     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'S')
10376     {
10377 	/* vim_strsave_shellescape() needs a NUL terminated string. */
10378 	c = (*fnamep)[*fnamelen];
10379 	if (c != NUL)
10380 	    (*fnamep)[*fnamelen] = NUL;
10381 	p = vim_strsave_shellescape(*fnamep, FALSE, FALSE);
10382 	if (c != NUL)
10383 	    (*fnamep)[*fnamelen] = c;
10384 	if (p == NULL)
10385 	    return -1;
10386 	vim_free(*bufp);
10387 	*bufp = *fnamep = p;
10388 	*fnamelen = (int)STRLEN(p);
10389 	*usedlen += 2;
10390     }
10391 
10392     return valid;
10393 }
10394 
10395 /*
10396  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
10397  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
10398  * "flags" can be "g" to do a global substitute.
10399  * Returns an allocated string, NULL for error.
10400  */
10401     char_u *
10402 do_string_sub(
10403     char_u	*str,
10404     char_u	*pat,
10405     char_u	*sub,
10406     typval_T	*expr,
10407     char_u	*flags)
10408 {
10409     int		sublen;
10410     regmatch_T	regmatch;
10411     int		i;
10412     int		do_all;
10413     char_u	*tail;
10414     char_u	*end;
10415     garray_T	ga;
10416     char_u	*ret;
10417     char_u	*save_cpo;
10418     char_u	*zero_width = NULL;
10419 
10420     /* Make 'cpoptions' empty, so that the 'l' flag doesn't work here */
10421     save_cpo = p_cpo;
10422     p_cpo = empty_option;
10423 
10424     ga_init2(&ga, 1, 200);
10425 
10426     do_all = (flags[0] == 'g');
10427 
10428     regmatch.rm_ic = p_ic;
10429     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
10430     if (regmatch.regprog != NULL)
10431     {
10432 	tail = str;
10433 	end = str + STRLEN(str);
10434 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
10435 	{
10436 	    /* Skip empty match except for first match. */
10437 	    if (regmatch.startp[0] == regmatch.endp[0])
10438 	    {
10439 		if (zero_width == regmatch.startp[0])
10440 		{
10441 		    /* avoid getting stuck on a match with an empty string */
10442 		    i = MB_PTR2LEN(tail);
10443 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
10444 								   (size_t)i);
10445 		    ga.ga_len += i;
10446 		    tail += i;
10447 		    continue;
10448 		}
10449 		zero_width = regmatch.startp[0];
10450 	    }
10451 
10452 	    /*
10453 	     * Get some space for a temporary buffer to do the substitution
10454 	     * into.  It will contain:
10455 	     * - The text up to where the match is.
10456 	     * - The substituted text.
10457 	     * - The text after the match.
10458 	     */
10459 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
10460 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
10461 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
10462 	    {
10463 		ga_clear(&ga);
10464 		break;
10465 	    }
10466 
10467 	    /* copy the text up to where the match is */
10468 	    i = (int)(regmatch.startp[0] - tail);
10469 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
10470 	    /* add the substituted text */
10471 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
10472 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
10473 	    ga.ga_len += i + sublen - 1;
10474 	    tail = regmatch.endp[0];
10475 	    if (*tail == NUL)
10476 		break;
10477 	    if (!do_all)
10478 		break;
10479 	}
10480 
10481 	if (ga.ga_data != NULL)
10482 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
10483 
10484 	vim_regfree(regmatch.regprog);
10485     }
10486 
10487     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
10488     ga_clear(&ga);
10489     if (p_cpo == empty_option)
10490 	p_cpo = save_cpo;
10491     else
10492 	/* Darn, evaluating {sub} expression or {expr} changed the value. */
10493 	free_string_option(save_cpo);
10494 
10495     return ret;
10496 }
10497 
10498     static int
10499 filter_map_one(typval_T *tv, typval_T *expr, int map, int *remp)
10500 {
10501     typval_T	rettv;
10502     typval_T	argv[3];
10503     int		retval = FAIL;
10504 
10505     copy_tv(tv, &vimvars[VV_VAL].vv_tv);
10506     argv[0] = vimvars[VV_KEY].vv_tv;
10507     argv[1] = vimvars[VV_VAL].vv_tv;
10508     if (eval_expr_typval(expr, argv, 2, &rettv) == FAIL)
10509 	goto theend;
10510     if (map)
10511     {
10512 	/* map(): replace the list item value */
10513 	clear_tv(tv);
10514 	rettv.v_lock = 0;
10515 	*tv = rettv;
10516     }
10517     else
10518     {
10519 	int	    error = FALSE;
10520 
10521 	/* filter(): when expr is zero remove the item */
10522 	*remp = (tv_get_number_chk(&rettv, &error) == 0);
10523 	clear_tv(&rettv);
10524 	/* On type error, nothing has been removed; return FAIL to stop the
10525 	 * loop.  The error message was given by tv_get_number_chk(). */
10526 	if (error)
10527 	    goto theend;
10528     }
10529     retval = OK;
10530 theend:
10531     clear_tv(&vimvars[VV_VAL].vv_tv);
10532     return retval;
10533 }
10534 
10535 
10536 /*
10537  * Implementation of map() and filter().
10538  */
10539     void
10540 filter_map(typval_T *argvars, typval_T *rettv, int map)
10541 {
10542     typval_T	*expr;
10543     listitem_T	*li, *nli;
10544     list_T	*l = NULL;
10545     dictitem_T	*di;
10546     hashtab_T	*ht;
10547     hashitem_T	*hi;
10548     dict_T	*d = NULL;
10549     typval_T	save_val;
10550     typval_T	save_key;
10551     blob_T	*b = NULL;
10552     int		rem;
10553     int		todo;
10554     char_u	*ermsg = (char_u *)(map ? "map()" : "filter()");
10555     char_u	*arg_errmsg = (char_u *)(map ? N_("map() argument")
10556 				   : N_("filter() argument"));
10557     int		save_did_emsg;
10558     int		idx = 0;
10559 
10560     if (argvars[0].v_type == VAR_BLOB)
10561     {
10562 	if ((b = argvars[0].vval.v_blob) == NULL)
10563 	    return;
10564     }
10565     else if (argvars[0].v_type == VAR_LIST)
10566     {
10567 	if ((l = argvars[0].vval.v_list) == NULL
10568 	      || (!map && var_check_lock(l->lv_lock, arg_errmsg, TRUE)))
10569 	    return;
10570     }
10571     else if (argvars[0].v_type == VAR_DICT)
10572     {
10573 	if ((d = argvars[0].vval.v_dict) == NULL
10574 	      || (!map && var_check_lock(d->dv_lock, arg_errmsg, TRUE)))
10575 	    return;
10576     }
10577     else
10578     {
10579 	semsg(_(e_listdictarg), ermsg);
10580 	return;
10581     }
10582 
10583     expr = &argvars[1];
10584     /* On type errors, the preceding call has already displayed an error
10585      * message.  Avoid a misleading error message for an empty string that
10586      * was not passed as argument. */
10587     if (expr->v_type != VAR_UNKNOWN)
10588     {
10589 	prepare_vimvar(VV_VAL, &save_val);
10590 
10591 	/* We reset "did_emsg" to be able to detect whether an error
10592 	 * occurred during evaluation of the expression. */
10593 	save_did_emsg = did_emsg;
10594 	did_emsg = FALSE;
10595 
10596 	prepare_vimvar(VV_KEY, &save_key);
10597 	if (argvars[0].v_type == VAR_DICT)
10598 	{
10599 	    vimvars[VV_KEY].vv_type = VAR_STRING;
10600 
10601 	    ht = &d->dv_hashtab;
10602 	    hash_lock(ht);
10603 	    todo = (int)ht->ht_used;
10604 	    for (hi = ht->ht_array; todo > 0; ++hi)
10605 	    {
10606 		if (!HASHITEM_EMPTY(hi))
10607 		{
10608 		    int r;
10609 
10610 		    --todo;
10611 		    di = HI2DI(hi);
10612 		    if (map && (var_check_lock(di->di_tv.v_lock,
10613 							   arg_errmsg, TRUE)
10614 				|| var_check_ro(di->di_flags,
10615 							   arg_errmsg, TRUE)))
10616 			break;
10617 		    vimvars[VV_KEY].vv_str = vim_strsave(di->di_key);
10618 		    r = filter_map_one(&di->di_tv, expr, map, &rem);
10619 		    clear_tv(&vimvars[VV_KEY].vv_tv);
10620 		    if (r == FAIL || did_emsg)
10621 			break;
10622 		    if (!map && rem)
10623 		    {
10624 			if (var_check_fixed(di->di_flags, arg_errmsg, TRUE)
10625 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE))
10626 			    break;
10627 			dictitem_remove(d, di);
10628 		    }
10629 		}
10630 	    }
10631 	    hash_unlock(ht);
10632 	}
10633 	else if (argvars[0].v_type == VAR_BLOB)
10634 	{
10635 	    int		i;
10636 	    typval_T	tv;
10637 
10638 	    vimvars[VV_KEY].vv_type = VAR_NUMBER;
10639 	    for (i = 0; i < b->bv_ga.ga_len; i++)
10640 	    {
10641 		tv.v_type = VAR_NUMBER;
10642 		tv.vval.v_number = blob_get(b, i);
10643 		vimvars[VV_KEY].vv_nr = idx;
10644 		if (filter_map_one(&tv, expr, map, &rem) == FAIL || did_emsg)
10645 		    break;
10646 		if (tv.v_type != VAR_NUMBER)
10647 		{
10648 		    emsg(_(e_invalblob));
10649 		    return;
10650 		}
10651 		tv.v_type = VAR_NUMBER;
10652 		blob_set(b, i, tv.vval.v_number);
10653 		if (!map && rem)
10654 		{
10655 		    char_u *p = (char_u *)argvars[0].vval.v_blob->bv_ga.ga_data;
10656 
10657 		    mch_memmove(p + idx, p + i + 1,
10658 					      (size_t)b->bv_ga.ga_len - i - 1);
10659 		    --b->bv_ga.ga_len;
10660 		    --i;
10661 		}
10662 	    }
10663 	}
10664 	else
10665 	{
10666 	    // argvars[0].v_type == VAR_LIST
10667 	    vimvars[VV_KEY].vv_type = VAR_NUMBER;
10668 
10669 	    for (li = l->lv_first; li != NULL; li = nli)
10670 	    {
10671 		if (map && var_check_lock(li->li_tv.v_lock, arg_errmsg, TRUE))
10672 		    break;
10673 		nli = li->li_next;
10674 		vimvars[VV_KEY].vv_nr = idx;
10675 		if (filter_map_one(&li->li_tv, expr, map, &rem) == FAIL
10676 								  || did_emsg)
10677 		    break;
10678 		if (!map && rem)
10679 		    listitem_remove(l, li);
10680 		++idx;
10681 	    }
10682 	}
10683 
10684 	restore_vimvar(VV_KEY, &save_key);
10685 	restore_vimvar(VV_VAL, &save_val);
10686 
10687 	did_emsg |= save_did_emsg;
10688     }
10689 
10690     copy_tv(&argvars[0], rettv);
10691 }
10692 
10693 #endif /* defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) */
10694