xref: /vim-8.2.3635/src/eval.c (revision fc65cabb)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * eval.c: Expression evaluation.
12  */
13 #define USING_FLOAT_STUFF
14 
15 #include "vim.h"
16 
17 #if defined(FEAT_EVAL) || defined(PROTO)
18 
19 #ifdef VMS
20 # include <float.h>
21 #endif
22 
23 #define DICT_MAXNEST 100	/* maximum nesting of lists and dicts */
24 
25 static char *e_letunexp	= N_("E18: Unexpected characters in :let");
26 static char *e_undefvar = N_("E121: Undefined variable: %s");
27 static char *e_missbrac = N_("E111: Missing ']'");
28 static char *e_dictrange = N_("E719: Cannot use [:] with a Dictionary");
29 static char *e_letwrong = N_("E734: Wrong variable type for %s=");
30 static char *e_illvar = N_("E461: Illegal variable name: %s");
31 #ifdef FEAT_FLOAT
32 static char *e_float_as_string = N_("E806: using Float as a String");
33 #endif
34 
35 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
36 
37 static dictitem_T	globvars_var;		/* variable used for g: */
38 #define globvarht globvardict.dv_hashtab
39 
40 /*
41  * Old Vim variables such as "v:version" are also available without the "v:".
42  * Also in functions.  We need a special hashtable for them.
43  */
44 static hashtab_T	compat_hashtab;
45 
46 /*
47  * When recursively copying lists and dicts we need to remember which ones we
48  * have done to avoid endless recursiveness.  This unique ID is used for that.
49  * The last bit is used for previous_funccal, ignored when comparing.
50  */
51 static int current_copyID = 0;
52 
53 /*
54  * Array to hold the hashtab with variables local to each sourced script.
55  * Each item holds a variable (nameless) that points to the dict_T.
56  */
57 typedef struct
58 {
59     dictitem_T	sv_var;
60     dict_T	sv_dict;
61 } scriptvar_T;
62 
63 static garray_T	    ga_scripts = {0, 0, sizeof(scriptvar_T *), 4, NULL};
64 #define SCRIPT_SV(id) (((scriptvar_T **)ga_scripts.ga_data)[(id) - 1])
65 #define SCRIPT_VARS(id) (SCRIPT_SV(id)->sv_dict.dv_hashtab)
66 
67 static int echo_attr = 0;   /* attributes used for ":echo" */
68 
69 /* The names of packages that once were loaded are remembered. */
70 static garray_T		ga_loaded = {0, 0, sizeof(char_u *), 4, NULL};
71 
72 /*
73  * Info used by a ":for" loop.
74  */
75 typedef struct
76 {
77     int		fi_semicolon;	/* TRUE if ending in '; var]' */
78     int		fi_varcount;	/* nr of variables in the list */
79     listwatch_T	fi_lw;		/* keep an eye on the item used. */
80     list_T	*fi_list;	/* list being used */
81 } forinfo_T;
82 
83 
84 /*
85  * Array to hold the value of v: variables.
86  * The value is in a dictitem, so that it can also be used in the v: scope.
87  * The reason to use this table anyway is for very quick access to the
88  * variables with the VV_ defines.
89  */
90 
91 /* values for vv_flags: */
92 #define VV_COMPAT	1	/* compatible, also used without "v:" */
93 #define VV_RO		2	/* read-only */
94 #define VV_RO_SBX	4	/* read-only in the sandbox */
95 
96 #define VV_NAME(s, t)	s, {{t, 0, {0}}, 0, {0}}
97 
98 static struct vimvar
99 {
100     char	*vv_name;	/* name of variable, without v: */
101     dictitem16_T vv_di;		/* value and name for key (max 16 chars!) */
102     char	vv_flags;	/* VV_COMPAT, VV_RO, VV_RO_SBX */
103 } vimvars[VV_LEN] =
104 {
105     /*
106      * The order here must match the VV_ defines in vim.h!
107      * Initializing a union does not work, leave tv.vval empty to get zero's.
108      */
109     {VV_NAME("count",		 VAR_NUMBER), VV_COMPAT+VV_RO},
110     {VV_NAME("count1",		 VAR_NUMBER), VV_RO},
111     {VV_NAME("prevcount",	 VAR_NUMBER), VV_RO},
112     {VV_NAME("errmsg",		 VAR_STRING), VV_COMPAT},
113     {VV_NAME("warningmsg",	 VAR_STRING), 0},
114     {VV_NAME("statusmsg",	 VAR_STRING), 0},
115     {VV_NAME("shell_error",	 VAR_NUMBER), VV_COMPAT+VV_RO},
116     {VV_NAME("this_session",	 VAR_STRING), VV_COMPAT},
117     {VV_NAME("version",		 VAR_NUMBER), VV_COMPAT+VV_RO},
118     {VV_NAME("lnum",		 VAR_NUMBER), VV_RO_SBX},
119     {VV_NAME("termresponse",	 VAR_STRING), VV_RO},
120     {VV_NAME("fname",		 VAR_STRING), VV_RO},
121     {VV_NAME("lang",		 VAR_STRING), VV_RO},
122     {VV_NAME("lc_time",		 VAR_STRING), VV_RO},
123     {VV_NAME("ctype",		 VAR_STRING), VV_RO},
124     {VV_NAME("charconvert_from", VAR_STRING), VV_RO},
125     {VV_NAME("charconvert_to",	 VAR_STRING), VV_RO},
126     {VV_NAME("fname_in",	 VAR_STRING), VV_RO},
127     {VV_NAME("fname_out",	 VAR_STRING), VV_RO},
128     {VV_NAME("fname_new",	 VAR_STRING), VV_RO},
129     {VV_NAME("fname_diff",	 VAR_STRING), VV_RO},
130     {VV_NAME("cmdarg",		 VAR_STRING), VV_RO},
131     {VV_NAME("foldstart",	 VAR_NUMBER), VV_RO_SBX},
132     {VV_NAME("foldend",		 VAR_NUMBER), VV_RO_SBX},
133     {VV_NAME("folddashes",	 VAR_STRING), VV_RO_SBX},
134     {VV_NAME("foldlevel",	 VAR_NUMBER), VV_RO_SBX},
135     {VV_NAME("progname",	 VAR_STRING), VV_RO},
136     {VV_NAME("servername",	 VAR_STRING), VV_RO},
137     {VV_NAME("dying",		 VAR_NUMBER), VV_RO},
138     {VV_NAME("exception",	 VAR_STRING), VV_RO},
139     {VV_NAME("throwpoint",	 VAR_STRING), VV_RO},
140     {VV_NAME("register",	 VAR_STRING), VV_RO},
141     {VV_NAME("cmdbang",		 VAR_NUMBER), VV_RO},
142     {VV_NAME("insertmode",	 VAR_STRING), VV_RO},
143     {VV_NAME("val",		 VAR_UNKNOWN), VV_RO},
144     {VV_NAME("key",		 VAR_UNKNOWN), VV_RO},
145     {VV_NAME("profiling",	 VAR_NUMBER), VV_RO},
146     {VV_NAME("fcs_reason",	 VAR_STRING), VV_RO},
147     {VV_NAME("fcs_choice",	 VAR_STRING), 0},
148     {VV_NAME("beval_bufnr",	 VAR_NUMBER), VV_RO},
149     {VV_NAME("beval_winnr",	 VAR_NUMBER), VV_RO},
150     {VV_NAME("beval_winid",	 VAR_NUMBER), VV_RO},
151     {VV_NAME("beval_lnum",	 VAR_NUMBER), VV_RO},
152     {VV_NAME("beval_col",	 VAR_NUMBER), VV_RO},
153     {VV_NAME("beval_text",	 VAR_STRING), VV_RO},
154     {VV_NAME("scrollstart",	 VAR_STRING), 0},
155     {VV_NAME("swapname",	 VAR_STRING), VV_RO},
156     {VV_NAME("swapchoice",	 VAR_STRING), 0},
157     {VV_NAME("swapcommand",	 VAR_STRING), VV_RO},
158     {VV_NAME("char",		 VAR_STRING), 0},
159     {VV_NAME("mouse_win",	 VAR_NUMBER), 0},
160     {VV_NAME("mouse_winid",	 VAR_NUMBER), 0},
161     {VV_NAME("mouse_lnum",	 VAR_NUMBER), 0},
162     {VV_NAME("mouse_col",	 VAR_NUMBER), 0},
163     {VV_NAME("operator",	 VAR_STRING), VV_RO},
164     {VV_NAME("searchforward",	 VAR_NUMBER), 0},
165     {VV_NAME("hlsearch",	 VAR_NUMBER), 0},
166     {VV_NAME("oldfiles",	 VAR_LIST), 0},
167     {VV_NAME("windowid",	 VAR_NUMBER), VV_RO},
168     {VV_NAME("progpath",	 VAR_STRING), VV_RO},
169     {VV_NAME("completed_item",	 VAR_DICT), VV_RO},
170     {VV_NAME("option_new",	 VAR_STRING), VV_RO},
171     {VV_NAME("option_old",	 VAR_STRING), VV_RO},
172     {VV_NAME("option_type",	 VAR_STRING), VV_RO},
173     {VV_NAME("errors",		 VAR_LIST), 0},
174     {VV_NAME("false",		 VAR_SPECIAL), VV_RO},
175     {VV_NAME("true",		 VAR_SPECIAL), VV_RO},
176     {VV_NAME("null",		 VAR_SPECIAL), VV_RO},
177     {VV_NAME("none",		 VAR_SPECIAL), VV_RO},
178     {VV_NAME("vim_did_enter",	 VAR_NUMBER), VV_RO},
179     {VV_NAME("testing",		 VAR_NUMBER), 0},
180     {VV_NAME("t_number",	 VAR_NUMBER), VV_RO},
181     {VV_NAME("t_string",	 VAR_NUMBER), VV_RO},
182     {VV_NAME("t_func",		 VAR_NUMBER), VV_RO},
183     {VV_NAME("t_list",		 VAR_NUMBER), VV_RO},
184     {VV_NAME("t_dict",		 VAR_NUMBER), VV_RO},
185     {VV_NAME("t_float",		 VAR_NUMBER), VV_RO},
186     {VV_NAME("t_bool",		 VAR_NUMBER), VV_RO},
187     {VV_NAME("t_none",		 VAR_NUMBER), VV_RO},
188     {VV_NAME("t_job",		 VAR_NUMBER), VV_RO},
189     {VV_NAME("t_channel",	 VAR_NUMBER), VV_RO},
190     {VV_NAME("termrfgresp",	 VAR_STRING), VV_RO},
191     {VV_NAME("termrbgresp",	 VAR_STRING), VV_RO},
192     {VV_NAME("termu7resp",	 VAR_STRING), VV_RO},
193     {VV_NAME("termstyleresp",	VAR_STRING), VV_RO},
194     {VV_NAME("termblinkresp",	VAR_STRING), VV_RO},
195     {VV_NAME("event",		VAR_DICT), VV_RO},
196 };
197 
198 /* shorthand */
199 #define vv_type		vv_di.di_tv.v_type
200 #define vv_nr		vv_di.di_tv.vval.v_number
201 #define vv_float	vv_di.di_tv.vval.v_float
202 #define vv_str		vv_di.di_tv.vval.v_string
203 #define vv_list		vv_di.di_tv.vval.v_list
204 #define vv_dict		vv_di.di_tv.vval.v_dict
205 #define vv_tv		vv_di.di_tv
206 
207 static dictitem_T	vimvars_var;		/* variable used for v: */
208 #define vimvarht  vimvardict.dv_hashtab
209 
210 static int ex_let_vars(char_u *arg, typval_T *tv, int copy, int semicolon, int var_count, char_u *nextchars);
211 static char_u *skip_var_list(char_u *arg, int *var_count, int *semicolon);
212 static char_u *skip_var_one(char_u *arg);
213 static void list_glob_vars(int *first);
214 static void list_buf_vars(int *first);
215 static void list_win_vars(int *first);
216 static void list_tab_vars(int *first);
217 static void list_vim_vars(int *first);
218 static void list_script_vars(int *first);
219 static char_u *list_arg_vars(exarg_T *eap, char_u *arg, int *first);
220 static char_u *ex_let_one(char_u *arg, typval_T *tv, int copy, char_u *endchars, char_u *op);
221 static void set_var_lval(lval_T *lp, char_u *endp, typval_T *rettv, int copy, char_u *op);
222 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
223 static void ex_unletlock(exarg_T *eap, char_u *argstart, int deep);
224 static int do_unlet_var(lval_T *lp, char_u *name_end, int forceit);
225 static int do_lock_var(lval_T *lp, char_u *name_end, int deep, int lock);
226 static void item_lock(typval_T *tv, int deep, int lock);
227 
228 static int eval2(char_u **arg, typval_T *rettv, int evaluate);
229 static int eval3(char_u **arg, typval_T *rettv, int evaluate);
230 static int eval4(char_u **arg, typval_T *rettv, int evaluate);
231 static int eval5(char_u **arg, typval_T *rettv, int evaluate);
232 static int eval6(char_u **arg, typval_T *rettv, int evaluate, int want_string);
233 static int eval7(char_u **arg, typval_T *rettv, int evaluate, int want_string);
234 
235 static int eval_index(char_u **arg, typval_T *rettv, int evaluate, int verbose);
236 static int get_string_tv(char_u **arg, typval_T *rettv, int evaluate);
237 static int get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate);
238 static int free_unref_items(int copyID);
239 static int get_env_tv(char_u **arg, typval_T *rettv, int evaluate);
240 static int get_env_len(char_u **arg);
241 static char_u * make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
242 static void check_vars(char_u *name, int len);
243 static typval_T *alloc_string_tv(char_u *string);
244 static void delete_var(hashtab_T *ht, hashitem_T *hi);
245 static void list_one_var(dictitem_T *v, char_u *prefix, int *first);
246 static void list_one_var_a(char_u *prefix, char_u *name, int type, char_u *string, int *first);
247 static char_u *find_option_end(char_u **arg, int *opt_flags);
248 
249 /* for VIM_VERSION_ defines */
250 #include "version.h"
251 
252 
253 #if defined(EBCDIC) || defined(PROTO)
254 /*
255  * Compare struct fst by function name.
256  */
257     static int
258 compare_func_name(const void *s1, const void *s2)
259 {
260     struct fst *p1 = (struct fst *)s1;
261     struct fst *p2 = (struct fst *)s2;
262 
263     return STRCMP(p1->f_name, p2->f_name);
264 }
265 
266 /*
267  * Sort the function table by function name.
268  * The sorting of the table above is ASCII dependant.
269  * On machines using EBCDIC we have to sort it.
270  */
271     static void
272 sortFunctions(void)
273 {
274     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
275 
276     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
277 }
278 #endif
279 
280 
281 /*
282  * Initialize the global and v: variables.
283  */
284     void
285 eval_init(void)
286 {
287     int		    i;
288     struct vimvar   *p;
289 
290     init_var_dict(&globvardict, &globvars_var, VAR_DEF_SCOPE);
291     init_var_dict(&vimvardict, &vimvars_var, VAR_SCOPE);
292     vimvardict.dv_lock = VAR_FIXED;
293     hash_init(&compat_hashtab);
294     func_init();
295 
296     for (i = 0; i < VV_LEN; ++i)
297     {
298 	p = &vimvars[i];
299 	if (STRLEN(p->vv_name) > 16)
300 	{
301 	    IEMSG("INTERNAL: name too long, increase size of dictitem16_T");
302 	    getout(1);
303 	}
304 	STRCPY(p->vv_di.di_key, p->vv_name);
305 	if (p->vv_flags & VV_RO)
306 	    p->vv_di.di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
307 	else if (p->vv_flags & VV_RO_SBX)
308 	    p->vv_di.di_flags = DI_FLAGS_RO_SBX | DI_FLAGS_FIX;
309 	else
310 	    p->vv_di.di_flags = DI_FLAGS_FIX;
311 
312 	/* add to v: scope dict, unless the value is not always available */
313 	if (p->vv_type != VAR_UNKNOWN)
314 	    hash_add(&vimvarht, p->vv_di.di_key);
315 	if (p->vv_flags & VV_COMPAT)
316 	    /* add to compat scope dict */
317 	    hash_add(&compat_hashtab, p->vv_di.di_key);
318     }
319     vimvars[VV_VERSION].vv_nr = VIM_VERSION_100;
320 
321     set_vim_var_nr(VV_SEARCHFORWARD, 1L);
322     set_vim_var_nr(VV_HLSEARCH, 1L);
323     set_vim_var_dict(VV_COMPLETED_ITEM, dict_alloc_lock(VAR_FIXED));
324     set_vim_var_list(VV_ERRORS, list_alloc());
325     set_vim_var_dict(VV_EVENT, dict_alloc_lock(VAR_FIXED));
326 
327     set_vim_var_nr(VV_FALSE, VVAL_FALSE);
328     set_vim_var_nr(VV_TRUE, VVAL_TRUE);
329     set_vim_var_nr(VV_NONE, VVAL_NONE);
330     set_vim_var_nr(VV_NULL, VVAL_NULL);
331 
332     set_vim_var_nr(VV_TYPE_NUMBER,  VAR_TYPE_NUMBER);
333     set_vim_var_nr(VV_TYPE_STRING,  VAR_TYPE_STRING);
334     set_vim_var_nr(VV_TYPE_FUNC,    VAR_TYPE_FUNC);
335     set_vim_var_nr(VV_TYPE_LIST,    VAR_TYPE_LIST);
336     set_vim_var_nr(VV_TYPE_DICT,    VAR_TYPE_DICT);
337     set_vim_var_nr(VV_TYPE_FLOAT,   VAR_TYPE_FLOAT);
338     set_vim_var_nr(VV_TYPE_BOOL,    VAR_TYPE_BOOL);
339     set_vim_var_nr(VV_TYPE_NONE,    VAR_TYPE_NONE);
340     set_vim_var_nr(VV_TYPE_JOB,     VAR_TYPE_JOB);
341     set_vim_var_nr(VV_TYPE_CHANNEL, VAR_TYPE_CHANNEL);
342 
343     set_reg_var(0);  /* default for v:register is not 0 but '"' */
344 
345 #ifdef EBCDIC
346     /*
347      * Sort the function table, to enable binary search.
348      */
349     sortFunctions();
350 #endif
351 }
352 
353 #if defined(EXITFREE) || defined(PROTO)
354     void
355 eval_clear(void)
356 {
357     int		    i;
358     struct vimvar   *p;
359 
360     for (i = 0; i < VV_LEN; ++i)
361     {
362 	p = &vimvars[i];
363 	if (p->vv_di.di_tv.v_type == VAR_STRING)
364 	    VIM_CLEAR(p->vv_str);
365 	else if (p->vv_di.di_tv.v_type == VAR_LIST)
366 	{
367 	    list_unref(p->vv_list);
368 	    p->vv_list = NULL;
369 	}
370     }
371     hash_clear(&vimvarht);
372     hash_init(&vimvarht);  /* garbage_collect() will access it */
373     hash_clear(&compat_hashtab);
374 
375     free_scriptnames();
376 # if defined(FEAT_CMDL_COMPL)
377     free_locales();
378 # endif
379 
380     /* global variables */
381     vars_clear(&globvarht);
382 
383     /* autoloaded script names */
384     ga_clear_strings(&ga_loaded);
385 
386     /* Script-local variables. First clear all the variables and in a second
387      * loop free the scriptvar_T, because a variable in one script might hold
388      * a reference to the whole scope of another script. */
389     for (i = 1; i <= ga_scripts.ga_len; ++i)
390 	vars_clear(&SCRIPT_VARS(i));
391     for (i = 1; i <= ga_scripts.ga_len; ++i)
392 	vim_free(SCRIPT_SV(i));
393     ga_clear(&ga_scripts);
394 
395     /* unreferenced lists and dicts */
396     (void)garbage_collect(FALSE);
397 
398     /* functions */
399     free_all_functions();
400 }
401 #endif
402 
403 
404 /*
405  * Set an internal variable to a string value. Creates the variable if it does
406  * not already exist.
407  */
408     void
409 set_internal_string_var(char_u *name, char_u *value)
410 {
411     char_u	*val;
412     typval_T	*tvp;
413 
414     val = vim_strsave(value);
415     if (val != NULL)
416     {
417 	tvp = alloc_string_tv(val);
418 	if (tvp != NULL)
419 	{
420 	    set_var(name, tvp, FALSE);
421 	    free_tv(tvp);
422 	}
423     }
424 }
425 
426 static lval_T	*redir_lval = NULL;
427 #define EVALCMD_BUSY (redir_lval == (lval_T *)&redir_lval)
428 static garray_T redir_ga;	/* only valid when redir_lval is not NULL */
429 static char_u	*redir_endp = NULL;
430 static char_u	*redir_varname = NULL;
431 
432 /*
433  * Start recording command output to a variable
434  * When "append" is TRUE append to an existing variable.
435  * Returns OK if successfully completed the setup.  FAIL otherwise.
436  */
437     int
438 var_redir_start(char_u *name, int append)
439 {
440     int		save_emsg;
441     int		err;
442     typval_T	tv;
443 
444     /* Catch a bad name early. */
445     if (!eval_isnamec1(*name))
446     {
447 	EMSG(_(e_invarg));
448 	return FAIL;
449     }
450 
451     /* Make a copy of the name, it is used in redir_lval until redir ends. */
452     redir_varname = vim_strsave(name);
453     if (redir_varname == NULL)
454 	return FAIL;
455 
456     redir_lval = (lval_T *)alloc_clear((unsigned)sizeof(lval_T));
457     if (redir_lval == NULL)
458     {
459 	var_redir_stop();
460 	return FAIL;
461     }
462 
463     /* The output is stored in growarray "redir_ga" until redirection ends. */
464     ga_init2(&redir_ga, (int)sizeof(char), 500);
465 
466     /* Parse the variable name (can be a dict or list entry). */
467     redir_endp = get_lval(redir_varname, NULL, redir_lval, FALSE, FALSE, 0,
468 							     FNE_CHECK_START);
469     if (redir_endp == NULL || redir_lval->ll_name == NULL || *redir_endp != NUL)
470     {
471 	clear_lval(redir_lval);
472 	if (redir_endp != NULL && *redir_endp != NUL)
473 	    /* Trailing characters are present after the variable name */
474 	    EMSG(_(e_trailing));
475 	else
476 	    EMSG(_(e_invarg));
477 	redir_endp = NULL;  /* don't store a value, only cleanup */
478 	var_redir_stop();
479 	return FAIL;
480     }
481 
482     /* check if we can write to the variable: set it to or append an empty
483      * string */
484     save_emsg = did_emsg;
485     did_emsg = FALSE;
486     tv.v_type = VAR_STRING;
487     tv.vval.v_string = (char_u *)"";
488     if (append)
489 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, (char_u *)".");
490     else
491 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, (char_u *)"=");
492     clear_lval(redir_lval);
493     err = did_emsg;
494     did_emsg |= save_emsg;
495     if (err)
496     {
497 	redir_endp = NULL;  /* don't store a value, only cleanup */
498 	var_redir_stop();
499 	return FAIL;
500     }
501 
502     return OK;
503 }
504 
505 /*
506  * Append "value[value_len]" to the variable set by var_redir_start().
507  * The actual appending is postponed until redirection ends, because the value
508  * appended may in fact be the string we write to, changing it may cause freed
509  * memory to be used:
510  *   :redir => foo
511  *   :let foo
512  *   :redir END
513  */
514     void
515 var_redir_str(char_u *value, int value_len)
516 {
517     int		len;
518 
519     if (redir_lval == NULL)
520 	return;
521 
522     if (value_len == -1)
523 	len = (int)STRLEN(value);	/* Append the entire string */
524     else
525 	len = value_len;		/* Append only "value_len" characters */
526 
527     if (ga_grow(&redir_ga, len) == OK)
528     {
529 	mch_memmove((char *)redir_ga.ga_data + redir_ga.ga_len, value, len);
530 	redir_ga.ga_len += len;
531     }
532     else
533 	var_redir_stop();
534 }
535 
536 /*
537  * Stop redirecting command output to a variable.
538  * Frees the allocated memory.
539  */
540     void
541 var_redir_stop(void)
542 {
543     typval_T	tv;
544 
545     if (EVALCMD_BUSY)
546     {
547 	redir_lval = NULL;
548 	return;
549     }
550 
551     if (redir_lval != NULL)
552     {
553 	/* If there was no error: assign the text to the variable. */
554 	if (redir_endp != NULL)
555 	{
556 	    ga_append(&redir_ga, NUL);  /* Append the trailing NUL. */
557 	    tv.v_type = VAR_STRING;
558 	    tv.vval.v_string = redir_ga.ga_data;
559 	    /* Call get_lval() again, if it's inside a Dict or List it may
560 	     * have changed. */
561 	    redir_endp = get_lval(redir_varname, NULL, redir_lval,
562 					FALSE, FALSE, 0, FNE_CHECK_START);
563 	    if (redir_endp != NULL && redir_lval->ll_name != NULL)
564 		set_var_lval(redir_lval, redir_endp, &tv, FALSE, (char_u *)".");
565 	    clear_lval(redir_lval);
566 	}
567 
568 	/* free the collected output */
569 	VIM_CLEAR(redir_ga.ga_data);
570 
571 	VIM_CLEAR(redir_lval);
572     }
573     VIM_CLEAR(redir_varname);
574 }
575 
576 # if defined(FEAT_MBYTE) || defined(PROTO)
577     int
578 eval_charconvert(
579     char_u	*enc_from,
580     char_u	*enc_to,
581     char_u	*fname_from,
582     char_u	*fname_to)
583 {
584     int		err = FALSE;
585 
586     set_vim_var_string(VV_CC_FROM, enc_from, -1);
587     set_vim_var_string(VV_CC_TO, enc_to, -1);
588     set_vim_var_string(VV_FNAME_IN, fname_from, -1);
589     set_vim_var_string(VV_FNAME_OUT, fname_to, -1);
590     if (eval_to_bool(p_ccv, &err, NULL, FALSE))
591 	err = TRUE;
592     set_vim_var_string(VV_CC_FROM, NULL, -1);
593     set_vim_var_string(VV_CC_TO, NULL, -1);
594     set_vim_var_string(VV_FNAME_IN, NULL, -1);
595     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
596 
597     if (err)
598 	return FAIL;
599     return OK;
600 }
601 # endif
602 
603 # if defined(FEAT_POSTSCRIPT) || defined(PROTO)
604     int
605 eval_printexpr(char_u *fname, char_u *args)
606 {
607     int		err = FALSE;
608 
609     set_vim_var_string(VV_FNAME_IN, fname, -1);
610     set_vim_var_string(VV_CMDARG, args, -1);
611     if (eval_to_bool(p_pexpr, &err, NULL, FALSE))
612 	err = TRUE;
613     set_vim_var_string(VV_FNAME_IN, NULL, -1);
614     set_vim_var_string(VV_CMDARG, NULL, -1);
615 
616     if (err)
617     {
618 	mch_remove(fname);
619 	return FAIL;
620     }
621     return OK;
622 }
623 # endif
624 
625 # if defined(FEAT_DIFF) || defined(PROTO)
626     void
627 eval_diff(
628     char_u	*origfile,
629     char_u	*newfile,
630     char_u	*outfile)
631 {
632     int		err = FALSE;
633 
634     set_vim_var_string(VV_FNAME_IN, origfile, -1);
635     set_vim_var_string(VV_FNAME_NEW, newfile, -1);
636     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
637     (void)eval_to_bool(p_dex, &err, NULL, FALSE);
638     set_vim_var_string(VV_FNAME_IN, NULL, -1);
639     set_vim_var_string(VV_FNAME_NEW, NULL, -1);
640     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
641 }
642 
643     void
644 eval_patch(
645     char_u	*origfile,
646     char_u	*difffile,
647     char_u	*outfile)
648 {
649     int		err;
650 
651     set_vim_var_string(VV_FNAME_IN, origfile, -1);
652     set_vim_var_string(VV_FNAME_DIFF, difffile, -1);
653     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
654     (void)eval_to_bool(p_pex, &err, NULL, FALSE);
655     set_vim_var_string(VV_FNAME_IN, NULL, -1);
656     set_vim_var_string(VV_FNAME_DIFF, NULL, -1);
657     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
658 }
659 # endif
660 
661 /*
662  * Top level evaluation function, returning a boolean.
663  * Sets "error" to TRUE if there was an error.
664  * Return TRUE or FALSE.
665  */
666     int
667 eval_to_bool(
668     char_u	*arg,
669     int		*error,
670     char_u	**nextcmd,
671     int		skip)	    /* only parse, don't execute */
672 {
673     typval_T	tv;
674     varnumber_T	retval = FALSE;
675 
676     if (skip)
677 	++emsg_skip;
678     if (eval0(arg, &tv, nextcmd, !skip) == FAIL)
679 	*error = TRUE;
680     else
681     {
682 	*error = FALSE;
683 	if (!skip)
684 	{
685 	    retval = (get_tv_number_chk(&tv, error) != 0);
686 	    clear_tv(&tv);
687 	}
688     }
689     if (skip)
690 	--emsg_skip;
691 
692     return (int)retval;
693 }
694 
695     static int
696 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
697 {
698     char_u	*s;
699     int		dummy;
700     char_u	buf[NUMBUFLEN];
701 
702     if (expr->v_type == VAR_FUNC)
703     {
704 	s = expr->vval.v_string;
705 	if (s == NULL || *s == NUL)
706 	    return FAIL;
707 	if (call_func(s, (int)STRLEN(s), rettv, argc, argv, NULL,
708 				     0L, 0L, &dummy, TRUE, NULL, NULL) == FAIL)
709 	    return FAIL;
710     }
711     else if (expr->v_type == VAR_PARTIAL)
712     {
713 	partial_T   *partial = expr->vval.v_partial;
714 
715 	s = partial_name(partial);
716 	if (s == NULL || *s == NUL)
717 	    return FAIL;
718 	if (call_func(s, (int)STRLEN(s), rettv, argc, argv, NULL,
719 				  0L, 0L, &dummy, TRUE, partial, NULL) == FAIL)
720 	    return FAIL;
721     }
722     else
723     {
724 	s = get_tv_string_buf_chk(expr, buf);
725 	if (s == NULL)
726 	    return FAIL;
727 	s = skipwhite(s);
728 	if (eval1(&s, rettv, TRUE) == FAIL)
729 	    return FAIL;
730 	if (*s != NUL)  /* check for trailing chars after expr */
731 	{
732 	    clear_tv(rettv);
733 	    EMSG2(_(e_invexpr2), s);
734 	    return FAIL;
735 	}
736     }
737     return OK;
738 }
739 
740 /*
741  * Like eval_to_bool() but using a typval_T instead of a string.
742  * Works for string, funcref and partial.
743  */
744     int
745 eval_expr_to_bool(typval_T *expr, int *error)
746 {
747     typval_T	rettv;
748     int		res;
749 
750     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
751     {
752 	*error = TRUE;
753 	return FALSE;
754     }
755     res = (get_tv_number_chk(&rettv, error) != 0);
756     clear_tv(&rettv);
757     return res;
758 }
759 
760 /*
761  * Top level evaluation function, returning a string.  If "skip" is TRUE,
762  * only parsing to "nextcmd" is done, without reporting errors.  Return
763  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
764  */
765     char_u *
766 eval_to_string_skip(
767     char_u	*arg,
768     char_u	**nextcmd,
769     int		skip)	    /* only parse, don't execute */
770 {
771     typval_T	tv;
772     char_u	*retval;
773 
774     if (skip)
775 	++emsg_skip;
776     if (eval0(arg, &tv, nextcmd, !skip) == FAIL || skip)
777 	retval = NULL;
778     else
779     {
780 	retval = vim_strsave(get_tv_string(&tv));
781 	clear_tv(&tv);
782     }
783     if (skip)
784 	--emsg_skip;
785 
786     return retval;
787 }
788 
789 /*
790  * Skip over an expression at "*pp".
791  * Return FAIL for an error, OK otherwise.
792  */
793     int
794 skip_expr(char_u **pp)
795 {
796     typval_T	rettv;
797 
798     *pp = skipwhite(*pp);
799     return eval1(pp, &rettv, FALSE);
800 }
801 
802 /*
803  * Top level evaluation function, returning a string.
804  * When "convert" is TRUE convert a List into a sequence of lines and convert
805  * a Float to a String.
806  * Return pointer to allocated memory, or NULL for failure.
807  */
808     char_u *
809 eval_to_string(
810     char_u	*arg,
811     char_u	**nextcmd,
812     int		convert)
813 {
814     typval_T	tv;
815     char_u	*retval;
816     garray_T	ga;
817 #ifdef FEAT_FLOAT
818     char_u	numbuf[NUMBUFLEN];
819 #endif
820 
821     if (eval0(arg, &tv, nextcmd, TRUE) == FAIL)
822 	retval = NULL;
823     else
824     {
825 	if (convert && tv.v_type == VAR_LIST)
826 	{
827 	    ga_init2(&ga, (int)sizeof(char), 80);
828 	    if (tv.vval.v_list != NULL)
829 	    {
830 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
831 		if (tv.vval.v_list->lv_len > 0)
832 		    ga_append(&ga, NL);
833 	    }
834 	    ga_append(&ga, NUL);
835 	    retval = (char_u *)ga.ga_data;
836 	}
837 #ifdef FEAT_FLOAT
838 	else if (convert && tv.v_type == VAR_FLOAT)
839 	{
840 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
841 	    retval = vim_strsave(numbuf);
842 	}
843 #endif
844 	else
845 	    retval = vim_strsave(get_tv_string(&tv));
846 	clear_tv(&tv);
847     }
848 
849     return retval;
850 }
851 
852 /*
853  * Call eval_to_string() without using current local variables and using
854  * textlock.  When "use_sandbox" is TRUE use the sandbox.
855  */
856     char_u *
857 eval_to_string_safe(
858     char_u	*arg,
859     char_u	**nextcmd,
860     int		use_sandbox)
861 {
862     char_u	*retval;
863     void	*save_funccalp;
864 
865     save_funccalp = save_funccal();
866     if (use_sandbox)
867 	++sandbox;
868     ++textlock;
869     retval = eval_to_string(arg, nextcmd, FALSE);
870     if (use_sandbox)
871 	--sandbox;
872     --textlock;
873     restore_funccal(save_funccalp);
874     return retval;
875 }
876 
877 /*
878  * Top level evaluation function, returning a number.
879  * Evaluates "expr" silently.
880  * Returns -1 for an error.
881  */
882     varnumber_T
883 eval_to_number(char_u *expr)
884 {
885     typval_T	rettv;
886     varnumber_T	retval;
887     char_u	*p = skipwhite(expr);
888 
889     ++emsg_off;
890 
891     if (eval1(&p, &rettv, TRUE) == FAIL)
892 	retval = -1;
893     else
894     {
895 	retval = get_tv_number_chk(&rettv, NULL);
896 	clear_tv(&rettv);
897     }
898     --emsg_off;
899 
900     return retval;
901 }
902 
903 /*
904  * Prepare v: variable "idx" to be used.
905  * Save the current typeval in "save_tv".
906  * When not used yet add the variable to the v: hashtable.
907  */
908     static void
909 prepare_vimvar(int idx, typval_T *save_tv)
910 {
911     *save_tv = vimvars[idx].vv_tv;
912     if (vimvars[idx].vv_type == VAR_UNKNOWN)
913 	hash_add(&vimvarht, vimvars[idx].vv_di.di_key);
914 }
915 
916 /*
917  * Restore v: variable "idx" to typeval "save_tv".
918  * When no longer defined, remove the variable from the v: hashtable.
919  */
920     static void
921 restore_vimvar(int idx, typval_T *save_tv)
922 {
923     hashitem_T	*hi;
924 
925     vimvars[idx].vv_tv = *save_tv;
926     if (vimvars[idx].vv_type == VAR_UNKNOWN)
927     {
928 	hi = hash_find(&vimvarht, vimvars[idx].vv_di.di_key);
929 	if (HASHITEM_EMPTY(hi))
930 	    internal_error("restore_vimvar()");
931 	else
932 	    hash_remove(&vimvarht, hi);
933     }
934 }
935 
936 #if defined(FEAT_SPELL) || defined(PROTO)
937 /*
938  * Evaluate an expression to a list with suggestions.
939  * For the "expr:" part of 'spellsuggest'.
940  * Returns NULL when there is an error.
941  */
942     list_T *
943 eval_spell_expr(char_u *badword, char_u *expr)
944 {
945     typval_T	save_val;
946     typval_T	rettv;
947     list_T	*list = NULL;
948     char_u	*p = skipwhite(expr);
949 
950     /* Set "v:val" to the bad word. */
951     prepare_vimvar(VV_VAL, &save_val);
952     vimvars[VV_VAL].vv_type = VAR_STRING;
953     vimvars[VV_VAL].vv_str = badword;
954     if (p_verbose == 0)
955 	++emsg_off;
956 
957     if (eval1(&p, &rettv, TRUE) == OK)
958     {
959 	if (rettv.v_type != VAR_LIST)
960 	    clear_tv(&rettv);
961 	else
962 	    list = rettv.vval.v_list;
963     }
964 
965     if (p_verbose == 0)
966 	--emsg_off;
967     restore_vimvar(VV_VAL, &save_val);
968 
969     return list;
970 }
971 
972 /*
973  * "list" is supposed to contain two items: a word and a number.  Return the
974  * word in "pp" and the number as the return value.
975  * Return -1 if anything isn't right.
976  * Used to get the good word and score from the eval_spell_expr() result.
977  */
978     int
979 get_spellword(list_T *list, char_u **pp)
980 {
981     listitem_T	*li;
982 
983     li = list->lv_first;
984     if (li == NULL)
985 	return -1;
986     *pp = get_tv_string(&li->li_tv);
987 
988     li = li->li_next;
989     if (li == NULL)
990 	return -1;
991     return (int)get_tv_number(&li->li_tv);
992 }
993 #endif
994 
995 /*
996  * Top level evaluation function.
997  * Returns an allocated typval_T with the result.
998  * Returns NULL when there is an error.
999  */
1000     typval_T *
1001 eval_expr(char_u *arg, char_u **nextcmd)
1002 {
1003     typval_T	*tv;
1004 
1005     tv = (typval_T *)alloc(sizeof(typval_T));
1006     if (tv != NULL && eval0(arg, tv, nextcmd, TRUE) == FAIL)
1007 	VIM_CLEAR(tv);
1008 
1009     return tv;
1010 }
1011 
1012 
1013 /*
1014  * Call some Vim script function and return the result in "*rettv".
1015  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
1016  * should have type VAR_UNKNOWN.
1017  * Returns OK or FAIL.
1018  */
1019     int
1020 call_vim_function(
1021     char_u      *func,
1022     int		argc,
1023     typval_T	*argv,
1024     typval_T	*rettv)
1025 {
1026     int		doesrange;
1027     int		ret;
1028 
1029     rettv->v_type = VAR_UNKNOWN;		/* clear_tv() uses this */
1030     ret = call_func(func, (int)STRLEN(func), rettv, argc, argv, NULL,
1031 		    curwin->w_cursor.lnum, curwin->w_cursor.lnum,
1032 		    &doesrange, TRUE, NULL, NULL);
1033     if (ret == FAIL)
1034 	clear_tv(rettv);
1035 
1036     return ret;
1037 }
1038 
1039 /*
1040  * Call Vim script function "func" and return the result as a number.
1041  * Returns -1 when calling the function fails.
1042  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
1043  * have type VAR_UNKNOWN.
1044  */
1045     varnumber_T
1046 call_func_retnr(
1047     char_u      *func,
1048     int		argc,
1049     typval_T	*argv)
1050 {
1051     typval_T	rettv;
1052     varnumber_T	retval;
1053 
1054     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
1055 	return -1;
1056 
1057     retval = get_tv_number_chk(&rettv, NULL);
1058     clear_tv(&rettv);
1059     return retval;
1060 }
1061 
1062 #if (defined(FEAT_USR_CMDS) && defined(FEAT_CMDL_COMPL)) \
1063 	|| defined(FEAT_COMPL_FUNC) || defined(PROTO)
1064 
1065 # if (defined(FEAT_USR_CMDS) && defined(FEAT_CMDL_COMPL)) || defined(PROTO)
1066 /*
1067  * Call Vim script function "func" and return the result as a string.
1068  * Returns NULL when calling the function fails.
1069  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
1070  * have type VAR_UNKNOWN.
1071  */
1072     void *
1073 call_func_retstr(
1074     char_u      *func,
1075     int		argc,
1076     typval_T	*argv)
1077 {
1078     typval_T	rettv;
1079     char_u	*retval;
1080 
1081     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
1082 	return NULL;
1083 
1084     retval = vim_strsave(get_tv_string(&rettv));
1085     clear_tv(&rettv);
1086     return retval;
1087 }
1088 # endif
1089 
1090 /*
1091  * Call Vim script function "func" and return the result as a List.
1092  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
1093  * have type VAR_UNKNOWN.
1094  * Returns NULL when there is something wrong.
1095  */
1096     void *
1097 call_func_retlist(
1098     char_u      *func,
1099     int		argc,
1100     typval_T	*argv)
1101 {
1102     typval_T	rettv;
1103 
1104     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
1105 	return NULL;
1106 
1107     if (rettv.v_type != VAR_LIST)
1108     {
1109 	clear_tv(&rettv);
1110 	return NULL;
1111     }
1112 
1113     return rettv.vval.v_list;
1114 }
1115 #endif
1116 
1117 
1118 #ifdef FEAT_FOLDING
1119 /*
1120  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
1121  * it in "*cp".  Doesn't give error messages.
1122  */
1123     int
1124 eval_foldexpr(char_u *arg, int *cp)
1125 {
1126     typval_T	tv;
1127     varnumber_T	retval;
1128     char_u	*s;
1129     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
1130 								   OPT_LOCAL);
1131 
1132     ++emsg_off;
1133     if (use_sandbox)
1134 	++sandbox;
1135     ++textlock;
1136     *cp = NUL;
1137     if (eval0(arg, &tv, NULL, TRUE) == FAIL)
1138 	retval = 0;
1139     else
1140     {
1141 	/* If the result is a number, just return the number. */
1142 	if (tv.v_type == VAR_NUMBER)
1143 	    retval = tv.vval.v_number;
1144 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
1145 	    retval = 0;
1146 	else
1147 	{
1148 	    /* If the result is a string, check if there is a non-digit before
1149 	     * the number. */
1150 	    s = tv.vval.v_string;
1151 	    if (!VIM_ISDIGIT(*s) && *s != '-')
1152 		*cp = *s++;
1153 	    retval = atol((char *)s);
1154 	}
1155 	clear_tv(&tv);
1156     }
1157     --emsg_off;
1158     if (use_sandbox)
1159 	--sandbox;
1160     --textlock;
1161 
1162     return (int)retval;
1163 }
1164 #endif
1165 
1166 /*
1167  * ":let"			list all variable values
1168  * ":let var1 var2"		list variable values
1169  * ":let var = expr"		assignment command.
1170  * ":let var += expr"		assignment command.
1171  * ":let var -= expr"		assignment command.
1172  * ":let var .= expr"		assignment command.
1173  * ":let [var1, var2] = expr"	unpack list.
1174  */
1175     void
1176 ex_let(exarg_T *eap)
1177 {
1178     char_u	*arg = eap->arg;
1179     char_u	*expr = NULL;
1180     typval_T	rettv;
1181     int		i;
1182     int		var_count = 0;
1183     int		semicolon = 0;
1184     char_u	op[2];
1185     char_u	*argend;
1186     int		first = TRUE;
1187 
1188     argend = skip_var_list(arg, &var_count, &semicolon);
1189     if (argend == NULL)
1190 	return;
1191     if (argend > arg && argend[-1] == '.')  /* for var.='str' */
1192 	--argend;
1193     expr = skipwhite(argend);
1194     if (*expr != '=' && !(vim_strchr((char_u *)"+-.", *expr) != NULL
1195 			  && expr[1] == '='))
1196     {
1197 	/*
1198 	 * ":let" without "=": list variables
1199 	 */
1200 	if (*arg == '[')
1201 	    EMSG(_(e_invarg));
1202 	else if (!ends_excmd(*arg))
1203 	    /* ":let var1 var2" */
1204 	    arg = list_arg_vars(eap, arg, &first);
1205 	else if (!eap->skip)
1206 	{
1207 	    /* ":let" */
1208 	    list_glob_vars(&first);
1209 	    list_buf_vars(&first);
1210 	    list_win_vars(&first);
1211 	    list_tab_vars(&first);
1212 	    list_script_vars(&first);
1213 	    list_func_vars(&first);
1214 	    list_vim_vars(&first);
1215 	}
1216 	eap->nextcmd = check_nextcmd(arg);
1217     }
1218     else
1219     {
1220 	op[0] = '=';
1221 	op[1] = NUL;
1222 	if (*expr != '=')
1223 	{
1224 	    if (vim_strchr((char_u *)"+-.", *expr) != NULL)
1225 		op[0] = *expr;   /* +=, -= or .= */
1226 	    expr = skipwhite(expr + 2);
1227 	}
1228 	else
1229 	    expr = skipwhite(expr + 1);
1230 
1231 	if (eap->skip)
1232 	    ++emsg_skip;
1233 	i = eval0(expr, &rettv, &eap->nextcmd, !eap->skip);
1234 	if (eap->skip)
1235 	{
1236 	    if (i != FAIL)
1237 		clear_tv(&rettv);
1238 	    --emsg_skip;
1239 	}
1240 	else if (i != FAIL)
1241 	{
1242 	    (void)ex_let_vars(eap->arg, &rettv, FALSE, semicolon, var_count,
1243 									  op);
1244 	    clear_tv(&rettv);
1245 	}
1246     }
1247 }
1248 
1249 /*
1250  * Assign the typevalue "tv" to the variable or variables at "arg_start".
1251  * Handles both "var" with any type and "[var, var; var]" with a list type.
1252  * When "nextchars" is not NULL it points to a string with characters that
1253  * must appear after the variable(s).  Use "+", "-" or "." for add, subtract
1254  * or concatenate.
1255  * Returns OK or FAIL;
1256  */
1257     static int
1258 ex_let_vars(
1259     char_u	*arg_start,
1260     typval_T	*tv,
1261     int		copy,		/* copy values from "tv", don't move */
1262     int		semicolon,	/* from skip_var_list() */
1263     int		var_count,	/* from skip_var_list() */
1264     char_u	*nextchars)
1265 {
1266     char_u	*arg = arg_start;
1267     list_T	*l;
1268     int		i;
1269     listitem_T	*item;
1270     typval_T	ltv;
1271 
1272     if (*arg != '[')
1273     {
1274 	/*
1275 	 * ":let var = expr" or ":for var in list"
1276 	 */
1277 	if (ex_let_one(arg, tv, copy, nextchars, nextchars) == NULL)
1278 	    return FAIL;
1279 	return OK;
1280     }
1281 
1282     /*
1283      * ":let [v1, v2] = list" or ":for [v1, v2] in listlist"
1284      */
1285     if (tv->v_type != VAR_LIST || (l = tv->vval.v_list) == NULL)
1286     {
1287 	EMSG(_(e_listreq));
1288 	return FAIL;
1289     }
1290 
1291     i = list_len(l);
1292     if (semicolon == 0 && var_count < i)
1293     {
1294 	EMSG(_("E687: Less targets than List items"));
1295 	return FAIL;
1296     }
1297     if (var_count - semicolon > i)
1298     {
1299 	EMSG(_("E688: More targets than List items"));
1300 	return FAIL;
1301     }
1302 
1303     item = l->lv_first;
1304     while (*arg != ']')
1305     {
1306 	arg = skipwhite(arg + 1);
1307 	arg = ex_let_one(arg, &item->li_tv, TRUE, (char_u *)",;]", nextchars);
1308 	item = item->li_next;
1309 	if (arg == NULL)
1310 	    return FAIL;
1311 
1312 	arg = skipwhite(arg);
1313 	if (*arg == ';')
1314 	{
1315 	    /* Put the rest of the list (may be empty) in the var after ';'.
1316 	     * Create a new list for this. */
1317 	    l = list_alloc();
1318 	    if (l == NULL)
1319 		return FAIL;
1320 	    while (item != NULL)
1321 	    {
1322 		list_append_tv(l, &item->li_tv);
1323 		item = item->li_next;
1324 	    }
1325 
1326 	    ltv.v_type = VAR_LIST;
1327 	    ltv.v_lock = 0;
1328 	    ltv.vval.v_list = l;
1329 	    l->lv_refcount = 1;
1330 
1331 	    arg = ex_let_one(skipwhite(arg + 1), &ltv, FALSE,
1332 						    (char_u *)"]", nextchars);
1333 	    clear_tv(&ltv);
1334 	    if (arg == NULL)
1335 		return FAIL;
1336 	    break;
1337 	}
1338 	else if (*arg != ',' && *arg != ']')
1339 	{
1340 	    internal_error("ex_let_vars()");
1341 	    return FAIL;
1342 	}
1343     }
1344 
1345     return OK;
1346 }
1347 
1348 /*
1349  * Skip over assignable variable "var" or list of variables "[var, var]".
1350  * Used for ":let varvar = expr" and ":for varvar in expr".
1351  * For "[var, var]" increment "*var_count" for each variable.
1352  * for "[var, var; var]" set "semicolon".
1353  * Return NULL for an error.
1354  */
1355     static char_u *
1356 skip_var_list(
1357     char_u	*arg,
1358     int		*var_count,
1359     int		*semicolon)
1360 {
1361     char_u	*p, *s;
1362 
1363     if (*arg == '[')
1364     {
1365 	/* "[var, var]": find the matching ']'. */
1366 	p = arg;
1367 	for (;;)
1368 	{
1369 	    p = skipwhite(p + 1);	/* skip whites after '[', ';' or ',' */
1370 	    s = skip_var_one(p);
1371 	    if (s == p)
1372 	    {
1373 		EMSG2(_(e_invarg2), p);
1374 		return NULL;
1375 	    }
1376 	    ++*var_count;
1377 
1378 	    p = skipwhite(s);
1379 	    if (*p == ']')
1380 		break;
1381 	    else if (*p == ';')
1382 	    {
1383 		if (*semicolon == 1)
1384 		{
1385 		    EMSG(_("Double ; in list of variables"));
1386 		    return NULL;
1387 		}
1388 		*semicolon = 1;
1389 	    }
1390 	    else if (*p != ',')
1391 	    {
1392 		EMSG2(_(e_invarg2), p);
1393 		return NULL;
1394 	    }
1395 	}
1396 	return p + 1;
1397     }
1398     else
1399 	return skip_var_one(arg);
1400 }
1401 
1402 /*
1403  * Skip one (assignable) variable name, including @r, $VAR, &option, d.key,
1404  * l[idx].
1405  */
1406     static char_u *
1407 skip_var_one(char_u *arg)
1408 {
1409     if (*arg == '@' && arg[1] != NUL)
1410 	return arg + 2;
1411     return find_name_end(*arg == '$' || *arg == '&' ? arg + 1 : arg,
1412 				   NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1413 }
1414 
1415 /*
1416  * List variables for hashtab "ht" with prefix "prefix".
1417  * If "empty" is TRUE also list NULL strings as empty strings.
1418  */
1419     void
1420 list_hashtable_vars(
1421     hashtab_T	*ht,
1422     char_u	*prefix,
1423     int		empty,
1424     int		*first)
1425 {
1426     hashitem_T	*hi;
1427     dictitem_T	*di;
1428     int		todo;
1429 
1430     todo = (int)ht->ht_used;
1431     for (hi = ht->ht_array; todo > 0 && !got_int; ++hi)
1432     {
1433 	if (!HASHITEM_EMPTY(hi))
1434 	{
1435 	    --todo;
1436 	    di = HI2DI(hi);
1437 	    if (empty || di->di_tv.v_type != VAR_STRING
1438 					   || di->di_tv.vval.v_string != NULL)
1439 		list_one_var(di, prefix, first);
1440 	}
1441     }
1442 }
1443 
1444 /*
1445  * List global variables.
1446  */
1447     static void
1448 list_glob_vars(int *first)
1449 {
1450     list_hashtable_vars(&globvarht, (char_u *)"", TRUE, first);
1451 }
1452 
1453 /*
1454  * List buffer variables.
1455  */
1456     static void
1457 list_buf_vars(int *first)
1458 {
1459     list_hashtable_vars(&curbuf->b_vars->dv_hashtab, (char_u *)"b:",
1460 								 TRUE, first);
1461 }
1462 
1463 /*
1464  * List window variables.
1465  */
1466     static void
1467 list_win_vars(int *first)
1468 {
1469     list_hashtable_vars(&curwin->w_vars->dv_hashtab,
1470 						 (char_u *)"w:", TRUE, first);
1471 }
1472 
1473 /*
1474  * List tab page variables.
1475  */
1476     static void
1477 list_tab_vars(int *first)
1478 {
1479     list_hashtable_vars(&curtab->tp_vars->dv_hashtab,
1480 						 (char_u *)"t:", TRUE, first);
1481 }
1482 
1483 /*
1484  * List Vim variables.
1485  */
1486     static void
1487 list_vim_vars(int *first)
1488 {
1489     list_hashtable_vars(&vimvarht, (char_u *)"v:", FALSE, first);
1490 }
1491 
1492 /*
1493  * List script-local variables, if there is a script.
1494  */
1495     static void
1496 list_script_vars(int *first)
1497 {
1498     if (current_SID > 0 && current_SID <= ga_scripts.ga_len)
1499 	list_hashtable_vars(&SCRIPT_VARS(current_SID),
1500 						(char_u *)"s:", FALSE, first);
1501 }
1502 
1503 /*
1504  * List variables in "arg".
1505  */
1506     static char_u *
1507 list_arg_vars(exarg_T *eap, char_u *arg, int *first)
1508 {
1509     int		error = FALSE;
1510     int		len;
1511     char_u	*name;
1512     char_u	*name_start;
1513     char_u	*arg_subsc;
1514     char_u	*tofree;
1515     typval_T    tv;
1516 
1517     while (!ends_excmd(*arg) && !got_int)
1518     {
1519 	if (error || eap->skip)
1520 	{
1521 	    arg = find_name_end(arg, NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1522 	    if (!VIM_ISWHITE(*arg) && !ends_excmd(*arg))
1523 	    {
1524 		emsg_severe = TRUE;
1525 		EMSG(_(e_trailing));
1526 		break;
1527 	    }
1528 	}
1529 	else
1530 	{
1531 	    /* get_name_len() takes care of expanding curly braces */
1532 	    name_start = name = arg;
1533 	    len = get_name_len(&arg, &tofree, TRUE, TRUE);
1534 	    if (len <= 0)
1535 	    {
1536 		/* This is mainly to keep test 49 working: when expanding
1537 		 * curly braces fails overrule the exception error message. */
1538 		if (len < 0 && !aborting())
1539 		{
1540 		    emsg_severe = TRUE;
1541 		    EMSG2(_(e_invarg2), arg);
1542 		    break;
1543 		}
1544 		error = TRUE;
1545 	    }
1546 	    else
1547 	    {
1548 		if (tofree != NULL)
1549 		    name = tofree;
1550 		if (get_var_tv(name, len, &tv, NULL, TRUE, FALSE) == FAIL)
1551 		    error = TRUE;
1552 		else
1553 		{
1554 		    /* handle d.key, l[idx], f(expr) */
1555 		    arg_subsc = arg;
1556 		    if (handle_subscript(&arg, &tv, TRUE, TRUE) == FAIL)
1557 			error = TRUE;
1558 		    else
1559 		    {
1560 			if (arg == arg_subsc && len == 2 && name[1] == ':')
1561 			{
1562 			    switch (*name)
1563 			    {
1564 				case 'g': list_glob_vars(first); break;
1565 				case 'b': list_buf_vars(first); break;
1566 				case 'w': list_win_vars(first); break;
1567 				case 't': list_tab_vars(first); break;
1568 				case 'v': list_vim_vars(first); break;
1569 				case 's': list_script_vars(first); break;
1570 				case 'l': list_func_vars(first); break;
1571 				default:
1572 					  EMSG2(_("E738: Can't list variables for %s"), name);
1573 			    }
1574 			}
1575 			else
1576 			{
1577 			    char_u	numbuf[NUMBUFLEN];
1578 			    char_u	*tf;
1579 			    int		c;
1580 			    char_u	*s;
1581 
1582 			    s = echo_string(&tv, &tf, numbuf, 0);
1583 			    c = *arg;
1584 			    *arg = NUL;
1585 			    list_one_var_a((char_u *)"",
1586 				    arg == arg_subsc ? name : name_start,
1587 				    tv.v_type,
1588 				    s == NULL ? (char_u *)"" : s,
1589 				    first);
1590 			    *arg = c;
1591 			    vim_free(tf);
1592 			}
1593 			clear_tv(&tv);
1594 		    }
1595 		}
1596 	    }
1597 
1598 	    vim_free(tofree);
1599 	}
1600 
1601 	arg = skipwhite(arg);
1602     }
1603 
1604     return arg;
1605 }
1606 
1607 /*
1608  * Set one item of ":let var = expr" or ":let [v1, v2] = list" to its value.
1609  * Returns a pointer to the char just after the var name.
1610  * Returns NULL if there is an error.
1611  */
1612     static char_u *
1613 ex_let_one(
1614     char_u	*arg,		/* points to variable name */
1615     typval_T	*tv,		/* value to assign to variable */
1616     int		copy,		/* copy value from "tv" */
1617     char_u	*endchars,	/* valid chars after variable name  or NULL */
1618     char_u	*op)		/* "+", "-", "."  or NULL*/
1619 {
1620     int		c1;
1621     char_u	*name;
1622     char_u	*p;
1623     char_u	*arg_end = NULL;
1624     int		len;
1625     int		opt_flags;
1626     char_u	*tofree = NULL;
1627 
1628     /*
1629      * ":let $VAR = expr": Set environment variable.
1630      */
1631     if (*arg == '$')
1632     {
1633 	/* Find the end of the name. */
1634 	++arg;
1635 	name = arg;
1636 	len = get_env_len(&arg);
1637 	if (len == 0)
1638 	    EMSG2(_(e_invarg2), name - 1);
1639 	else
1640 	{
1641 	    if (op != NULL && (*op == '+' || *op == '-'))
1642 		EMSG2(_(e_letwrong), op);
1643 	    else if (endchars != NULL
1644 			     && vim_strchr(endchars, *skipwhite(arg)) == NULL)
1645 		EMSG(_(e_letunexp));
1646 	    else if (!check_secure())
1647 	    {
1648 		c1 = name[len];
1649 		name[len] = NUL;
1650 		p = get_tv_string_chk(tv);
1651 		if (p != NULL && op != NULL && *op == '.')
1652 		{
1653 		    int	    mustfree = FALSE;
1654 		    char_u  *s = vim_getenv(name, &mustfree);
1655 
1656 		    if (s != NULL)
1657 		    {
1658 			p = tofree = concat_str(s, p);
1659 			if (mustfree)
1660 			    vim_free(s);
1661 		    }
1662 		}
1663 		if (p != NULL)
1664 		{
1665 		    vim_setenv(name, p);
1666 		    if (STRICMP(name, "HOME") == 0)
1667 			init_homedir();
1668 		    else if (didset_vim && STRICMP(name, "VIM") == 0)
1669 			didset_vim = FALSE;
1670 		    else if (didset_vimruntime
1671 					&& STRICMP(name, "VIMRUNTIME") == 0)
1672 			didset_vimruntime = FALSE;
1673 		    arg_end = arg;
1674 		}
1675 		name[len] = c1;
1676 		vim_free(tofree);
1677 	    }
1678 	}
1679     }
1680 
1681     /*
1682      * ":let &option = expr": Set option value.
1683      * ":let &l:option = expr": Set local option value.
1684      * ":let &g:option = expr": Set global option value.
1685      */
1686     else if (*arg == '&')
1687     {
1688 	/* Find the end of the name. */
1689 	p = find_option_end(&arg, &opt_flags);
1690 	if (p == NULL || (endchars != NULL
1691 			      && vim_strchr(endchars, *skipwhite(p)) == NULL))
1692 	    EMSG(_(e_letunexp));
1693 	else
1694 	{
1695 	    long	n;
1696 	    int		opt_type;
1697 	    long	numval;
1698 	    char_u	*stringval = NULL;
1699 	    char_u	*s;
1700 
1701 	    c1 = *p;
1702 	    *p = NUL;
1703 
1704 	    n = (long)get_tv_number(tv);
1705 	    s = get_tv_string_chk(tv);	    /* != NULL if number or string */
1706 	    if (s != NULL && op != NULL && *op != '=')
1707 	    {
1708 		opt_type = get_option_value(arg, &numval,
1709 						       &stringval, opt_flags);
1710 		if ((opt_type == 1 && *op == '.')
1711 			|| (opt_type == 0 && *op != '.'))
1712 		{
1713 		    EMSG2(_(e_letwrong), op);
1714 		    s = NULL;  /* don't set the value */
1715 		}
1716 		else
1717 		{
1718 		    if (opt_type == 1)  /* number */
1719 		    {
1720 			if (*op == '+')
1721 			    n = numval + n;
1722 			else
1723 			    n = numval - n;
1724 		    }
1725 		    else if (opt_type == 0 && stringval != NULL) /* string */
1726 		    {
1727 			s = concat_str(stringval, s);
1728 			vim_free(stringval);
1729 			stringval = s;
1730 		    }
1731 		}
1732 	    }
1733 	    if (s != NULL)
1734 	    {
1735 		set_option_value(arg, n, s, opt_flags);
1736 		arg_end = p;
1737 	    }
1738 	    *p = c1;
1739 	    vim_free(stringval);
1740 	}
1741     }
1742 
1743     /*
1744      * ":let @r = expr": Set register contents.
1745      */
1746     else if (*arg == '@')
1747     {
1748 	++arg;
1749 	if (op != NULL && (*op == '+' || *op == '-'))
1750 	    EMSG2(_(e_letwrong), op);
1751 	else if (endchars != NULL
1752 			 && vim_strchr(endchars, *skipwhite(arg + 1)) == NULL)
1753 	    EMSG(_(e_letunexp));
1754 	else
1755 	{
1756 	    char_u	*ptofree = NULL;
1757 	    char_u	*s;
1758 
1759 	    p = get_tv_string_chk(tv);
1760 	    if (p != NULL && op != NULL && *op == '.')
1761 	    {
1762 		s = get_reg_contents(*arg == '@' ? '"' : *arg, GREG_EXPR_SRC);
1763 		if (s != NULL)
1764 		{
1765 		    p = ptofree = concat_str(s, p);
1766 		    vim_free(s);
1767 		}
1768 	    }
1769 	    if (p != NULL)
1770 	    {
1771 		write_reg_contents(*arg == '@' ? '"' : *arg, p, -1, FALSE);
1772 		arg_end = arg + 1;
1773 	    }
1774 	    vim_free(ptofree);
1775 	}
1776     }
1777 
1778     /*
1779      * ":let var = expr": Set internal variable.
1780      * ":let {expr} = expr": Idem, name made with curly braces
1781      */
1782     else if (eval_isnamec1(*arg) || *arg == '{')
1783     {
1784 	lval_T	lv;
1785 
1786 	p = get_lval(arg, tv, &lv, FALSE, FALSE, 0, FNE_CHECK_START);
1787 	if (p != NULL && lv.ll_name != NULL)
1788 	{
1789 	    if (endchars != NULL && vim_strchr(endchars, *skipwhite(p)) == NULL)
1790 		EMSG(_(e_letunexp));
1791 	    else
1792 	    {
1793 		set_var_lval(&lv, p, tv, copy, op);
1794 		arg_end = p;
1795 	    }
1796 	}
1797 	clear_lval(&lv);
1798     }
1799 
1800     else
1801 	EMSG2(_(e_invarg2), arg);
1802 
1803     return arg_end;
1804 }
1805 
1806 /*
1807  * Get an lval: variable, Dict item or List item that can be assigned a value
1808  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
1809  * "name.key", "name.key[expr]" etc.
1810  * Indexing only works if "name" is an existing List or Dictionary.
1811  * "name" points to the start of the name.
1812  * If "rettv" is not NULL it points to the value to be assigned.
1813  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
1814  * wrong; must end in space or cmd separator.
1815  *
1816  * flags:
1817  *  GLV_QUIET:       do not give error messages
1818  *  GLV_READ_ONLY:   will not change the variable
1819  *  GLV_NO_AUTOLOAD: do not use script autoloading
1820  *
1821  * Returns a pointer to just after the name, including indexes.
1822  * When an evaluation error occurs "lp->ll_name" is NULL;
1823  * Returns NULL for a parsing error.  Still need to free items in "lp"!
1824  */
1825     char_u *
1826 get_lval(
1827     char_u	*name,
1828     typval_T	*rettv,
1829     lval_T	*lp,
1830     int		unlet,
1831     int		skip,
1832     int		flags,	    /* GLV_ values */
1833     int		fne_flags)  /* flags for find_name_end() */
1834 {
1835     char_u	*p;
1836     char_u	*expr_start, *expr_end;
1837     int		cc;
1838     dictitem_T	*v;
1839     typval_T	var1;
1840     typval_T	var2;
1841     int		empty1 = FALSE;
1842     listitem_T	*ni;
1843     char_u	*key = NULL;
1844     int		len;
1845     hashtab_T	*ht;
1846     int		quiet = flags & GLV_QUIET;
1847 
1848     /* Clear everything in "lp". */
1849     vim_memset(lp, 0, sizeof(lval_T));
1850 
1851     if (skip)
1852     {
1853 	/* When skipping just find the end of the name. */
1854 	lp->ll_name = name;
1855 	return find_name_end(name, NULL, NULL, FNE_INCL_BR | fne_flags);
1856     }
1857 
1858     /* Find the end of the name. */
1859     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
1860     if (expr_start != NULL)
1861     {
1862 	/* Don't expand the name when we already know there is an error. */
1863 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
1864 						    && *p != '[' && *p != '.')
1865 	{
1866 	    EMSG(_(e_trailing));
1867 	    return NULL;
1868 	}
1869 
1870 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
1871 	if (lp->ll_exp_name == NULL)
1872 	{
1873 	    /* Report an invalid expression in braces, unless the
1874 	     * expression evaluation has been cancelled due to an
1875 	     * aborting error, an interrupt, or an exception. */
1876 	    if (!aborting() && !quiet)
1877 	    {
1878 		emsg_severe = TRUE;
1879 		EMSG2(_(e_invarg2), name);
1880 		return NULL;
1881 	    }
1882 	}
1883 	lp->ll_name = lp->ll_exp_name;
1884     }
1885     else
1886 	lp->ll_name = name;
1887 
1888     /* Without [idx] or .key we are done. */
1889     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
1890 	return p;
1891 
1892     cc = *p;
1893     *p = NUL;
1894     /* Only pass &ht when we would write to the variable, it prevents autoload
1895      * as well. */
1896     v = find_var(lp->ll_name, (flags & GLV_READ_ONLY) ? NULL : &ht,
1897 						      flags & GLV_NO_AUTOLOAD);
1898     if (v == NULL && !quiet)
1899 	EMSG2(_(e_undefvar), lp->ll_name);
1900     *p = cc;
1901     if (v == NULL)
1902 	return NULL;
1903 
1904     /*
1905      * Loop until no more [idx] or .key is following.
1906      */
1907     lp->ll_tv = &v->di_tv;
1908     var1.v_type = VAR_UNKNOWN;
1909     var2.v_type = VAR_UNKNOWN;
1910     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
1911     {
1912 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
1913 		&& !(lp->ll_tv->v_type == VAR_DICT
1914 					   && lp->ll_tv->vval.v_dict != NULL))
1915 	{
1916 	    if (!quiet)
1917 		EMSG(_("E689: Can only index a List or Dictionary"));
1918 	    return NULL;
1919 	}
1920 	if (lp->ll_range)
1921 	{
1922 	    if (!quiet)
1923 		EMSG(_("E708: [:] must come last"));
1924 	    return NULL;
1925 	}
1926 
1927 	len = -1;
1928 	if (*p == '.')
1929 	{
1930 	    key = p + 1;
1931 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
1932 		;
1933 	    if (len == 0)
1934 	    {
1935 		if (!quiet)
1936 		    EMSG(_(e_emptykey));
1937 		return NULL;
1938 	    }
1939 	    p = key + len;
1940 	}
1941 	else
1942 	{
1943 	    /* Get the index [expr] or the first index [expr: ]. */
1944 	    p = skipwhite(p + 1);
1945 	    if (*p == ':')
1946 		empty1 = TRUE;
1947 	    else
1948 	    {
1949 		empty1 = FALSE;
1950 		if (eval1(&p, &var1, TRUE) == FAIL)	/* recursive! */
1951 		    return NULL;
1952 		if (get_tv_string_chk(&var1) == NULL)
1953 		{
1954 		    /* not a number or string */
1955 		    clear_tv(&var1);
1956 		    return NULL;
1957 		}
1958 	    }
1959 
1960 	    /* Optionally get the second index [ :expr]. */
1961 	    if (*p == ':')
1962 	    {
1963 		if (lp->ll_tv->v_type == VAR_DICT)
1964 		{
1965 		    if (!quiet)
1966 			EMSG(_(e_dictrange));
1967 		    clear_tv(&var1);
1968 		    return NULL;
1969 		}
1970 		if (rettv != NULL && (rettv->v_type != VAR_LIST
1971 					       || rettv->vval.v_list == NULL))
1972 		{
1973 		    if (!quiet)
1974 			EMSG(_("E709: [:] requires a List value"));
1975 		    clear_tv(&var1);
1976 		    return NULL;
1977 		}
1978 		p = skipwhite(p + 1);
1979 		if (*p == ']')
1980 		    lp->ll_empty2 = TRUE;
1981 		else
1982 		{
1983 		    lp->ll_empty2 = FALSE;
1984 		    if (eval1(&p, &var2, TRUE) == FAIL)	/* recursive! */
1985 		    {
1986 			clear_tv(&var1);
1987 			return NULL;
1988 		    }
1989 		    if (get_tv_string_chk(&var2) == NULL)
1990 		    {
1991 			/* not a number or string */
1992 			clear_tv(&var1);
1993 			clear_tv(&var2);
1994 			return NULL;
1995 		    }
1996 		}
1997 		lp->ll_range = TRUE;
1998 	    }
1999 	    else
2000 		lp->ll_range = FALSE;
2001 
2002 	    if (*p != ']')
2003 	    {
2004 		if (!quiet)
2005 		    EMSG(_(e_missbrac));
2006 		clear_tv(&var1);
2007 		clear_tv(&var2);
2008 		return NULL;
2009 	    }
2010 
2011 	    /* Skip to past ']'. */
2012 	    ++p;
2013 	}
2014 
2015 	if (lp->ll_tv->v_type == VAR_DICT)
2016 	{
2017 	    if (len == -1)
2018 	    {
2019 		/* "[key]": get key from "var1" */
2020 		key = get_tv_string_chk(&var1);	/* is number or string */
2021 		if (key == NULL)
2022 		{
2023 		    clear_tv(&var1);
2024 		    return NULL;
2025 		}
2026 	    }
2027 	    lp->ll_list = NULL;
2028 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
2029 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
2030 
2031 	    /* When assigning to a scope dictionary check that a function and
2032 	     * variable name is valid (only variable name unless it is l: or
2033 	     * g: dictionary). Disallow overwriting a builtin function. */
2034 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
2035 	    {
2036 		int prevval;
2037 		int wrong;
2038 
2039 		if (len != -1)
2040 		{
2041 		    prevval = key[len];
2042 		    key[len] = NUL;
2043 		}
2044 		else
2045 		    prevval = 0; /* avoid compiler warning */
2046 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
2047 			       && rettv->v_type == VAR_FUNC
2048 			       && var_check_func_name(key, lp->ll_di == NULL))
2049 			|| !valid_varname(key);
2050 		if (len != -1)
2051 		    key[len] = prevval;
2052 		if (wrong)
2053 		    return NULL;
2054 	    }
2055 
2056 	    if (lp->ll_di == NULL)
2057 	    {
2058 		/* Can't add "v:" variable. */
2059 		if (lp->ll_dict == &vimvardict)
2060 		{
2061 		    EMSG2(_(e_illvar), name);
2062 		    return NULL;
2063 		}
2064 
2065 		/* Key does not exist in dict: may need to add it. */
2066 		if (*p == '[' || *p == '.' || unlet)
2067 		{
2068 		    if (!quiet)
2069 			EMSG2(_(e_dictkey), key);
2070 		    clear_tv(&var1);
2071 		    return NULL;
2072 		}
2073 		if (len == -1)
2074 		    lp->ll_newkey = vim_strsave(key);
2075 		else
2076 		    lp->ll_newkey = vim_strnsave(key, len);
2077 		clear_tv(&var1);
2078 		if (lp->ll_newkey == NULL)
2079 		    p = NULL;
2080 		break;
2081 	    }
2082 	    /* existing variable, need to check if it can be changed */
2083 	    else if ((flags & GLV_READ_ONLY) == 0
2084 			     && var_check_ro(lp->ll_di->di_flags, name, FALSE))
2085 	    {
2086 		clear_tv(&var1);
2087 		return NULL;
2088 	    }
2089 
2090 	    clear_tv(&var1);
2091 	    lp->ll_tv = &lp->ll_di->di_tv;
2092 	}
2093 	else
2094 	{
2095 	    /*
2096 	     * Get the number and item for the only or first index of the List.
2097 	     */
2098 	    if (empty1)
2099 		lp->ll_n1 = 0;
2100 	    else
2101 		/* is number or string */
2102 		lp->ll_n1 = (long)get_tv_number(&var1);
2103 	    clear_tv(&var1);
2104 
2105 	    lp->ll_dict = NULL;
2106 	    lp->ll_list = lp->ll_tv->vval.v_list;
2107 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2108 	    if (lp->ll_li == NULL)
2109 	    {
2110 		if (lp->ll_n1 < 0)
2111 		{
2112 		    lp->ll_n1 = 0;
2113 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2114 		}
2115 	    }
2116 	    if (lp->ll_li == NULL)
2117 	    {
2118 		clear_tv(&var2);
2119 		if (!quiet)
2120 		    EMSGN(_(e_listidx), lp->ll_n1);
2121 		return NULL;
2122 	    }
2123 
2124 	    /*
2125 	     * May need to find the item or absolute index for the second
2126 	     * index of a range.
2127 	     * When no index given: "lp->ll_empty2" is TRUE.
2128 	     * Otherwise "lp->ll_n2" is set to the second index.
2129 	     */
2130 	    if (lp->ll_range && !lp->ll_empty2)
2131 	    {
2132 		lp->ll_n2 = (long)get_tv_number(&var2);
2133 						    /* is number or string */
2134 		clear_tv(&var2);
2135 		if (lp->ll_n2 < 0)
2136 		{
2137 		    ni = list_find(lp->ll_list, lp->ll_n2);
2138 		    if (ni == NULL)
2139 		    {
2140 			if (!quiet)
2141 			    EMSGN(_(e_listidx), lp->ll_n2);
2142 			return NULL;
2143 		    }
2144 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
2145 		}
2146 
2147 		/* Check that lp->ll_n2 isn't before lp->ll_n1. */
2148 		if (lp->ll_n1 < 0)
2149 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
2150 		if (lp->ll_n2 < lp->ll_n1)
2151 		{
2152 		    if (!quiet)
2153 			EMSGN(_(e_listidx), lp->ll_n2);
2154 		    return NULL;
2155 		}
2156 	    }
2157 
2158 	    lp->ll_tv = &lp->ll_li->li_tv;
2159 	}
2160     }
2161 
2162     clear_tv(&var1);
2163     return p;
2164 }
2165 
2166 /*
2167  * Clear lval "lp" that was filled by get_lval().
2168  */
2169     void
2170 clear_lval(lval_T *lp)
2171 {
2172     vim_free(lp->ll_exp_name);
2173     vim_free(lp->ll_newkey);
2174 }
2175 
2176 /*
2177  * Set a variable that was parsed by get_lval() to "rettv".
2178  * "endp" points to just after the parsed name.
2179  * "op" is NULL, "+" for "+=", "-" for "-=", "." for ".=" or "=" for "=".
2180  */
2181     static void
2182 set_var_lval(
2183     lval_T	*lp,
2184     char_u	*endp,
2185     typval_T	*rettv,
2186     int		copy,
2187     char_u	*op)
2188 {
2189     int		cc;
2190     listitem_T	*ri;
2191     dictitem_T	*di;
2192 
2193     if (lp->ll_tv == NULL)
2194     {
2195 	cc = *endp;
2196 	*endp = NUL;
2197 	if (op != NULL && *op != '=')
2198 	{
2199 	    typval_T tv;
2200 
2201 	    /* handle +=, -= and .= */
2202 	    di = NULL;
2203 	    if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
2204 					     &tv, &di, TRUE, FALSE) == OK)
2205 	    {
2206 		if ((di == NULL
2207 		       || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
2208 			  && !tv_check_lock(di->di_tv.v_lock, lp->ll_name,
2209 								  FALSE)))
2210 			&& tv_op(&tv, rettv, op) == OK)
2211 		    set_var(lp->ll_name, &tv, FALSE);
2212 		clear_tv(&tv);
2213 	    }
2214 	}
2215 	else
2216 	    set_var(lp->ll_name, rettv, copy);
2217 	*endp = cc;
2218     }
2219     else if (tv_check_lock(lp->ll_newkey == NULL
2220 		? lp->ll_tv->v_lock
2221 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
2222 	;
2223     else if (lp->ll_range)
2224     {
2225 	listitem_T *ll_li = lp->ll_li;
2226 	int ll_n1 = lp->ll_n1;
2227 
2228 	/*
2229 	 * Check whether any of the list items is locked
2230 	 */
2231 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
2232 	{
2233 	    if (tv_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
2234 		return;
2235 	    ri = ri->li_next;
2236 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
2237 		break;
2238 	    ll_li = ll_li->li_next;
2239 	    ++ll_n1;
2240 	}
2241 
2242 	/*
2243 	 * Assign the List values to the list items.
2244 	 */
2245 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
2246 	{
2247 	    if (op != NULL && *op != '=')
2248 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
2249 	    else
2250 	    {
2251 		clear_tv(&lp->ll_li->li_tv);
2252 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
2253 	    }
2254 	    ri = ri->li_next;
2255 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
2256 		break;
2257 	    if (lp->ll_li->li_next == NULL)
2258 	    {
2259 		/* Need to add an empty item. */
2260 		if (list_append_number(lp->ll_list, 0) == FAIL)
2261 		{
2262 		    ri = NULL;
2263 		    break;
2264 		}
2265 	    }
2266 	    lp->ll_li = lp->ll_li->li_next;
2267 	    ++lp->ll_n1;
2268 	}
2269 	if (ri != NULL)
2270 	    EMSG(_("E710: List value has more items than target"));
2271 	else if (lp->ll_empty2
2272 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
2273 		: lp->ll_n1 != lp->ll_n2)
2274 	    EMSG(_("E711: List value has not enough items"));
2275     }
2276     else
2277     {
2278 	/*
2279 	 * Assign to a List or Dictionary item.
2280 	 */
2281 	if (lp->ll_newkey != NULL)
2282 	{
2283 	    if (op != NULL && *op != '=')
2284 	    {
2285 		EMSG2(_(e_letwrong), op);
2286 		return;
2287 	    }
2288 
2289 	    /* Need to add an item to the Dictionary. */
2290 	    di = dictitem_alloc(lp->ll_newkey);
2291 	    if (di == NULL)
2292 		return;
2293 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
2294 	    {
2295 		vim_free(di);
2296 		return;
2297 	    }
2298 	    lp->ll_tv = &di->di_tv;
2299 	}
2300 	else if (op != NULL && *op != '=')
2301 	{
2302 	    tv_op(lp->ll_tv, rettv, op);
2303 	    return;
2304 	}
2305 	else
2306 	    clear_tv(lp->ll_tv);
2307 
2308 	/*
2309 	 * Assign the value to the variable or list item.
2310 	 */
2311 	if (copy)
2312 	    copy_tv(rettv, lp->ll_tv);
2313 	else
2314 	{
2315 	    *lp->ll_tv = *rettv;
2316 	    lp->ll_tv->v_lock = 0;
2317 	    init_tv(rettv);
2318 	}
2319     }
2320 }
2321 
2322 /*
2323  * Handle "tv1 += tv2", "tv1 -= tv2" and "tv1 .= tv2"
2324  * Returns OK or FAIL.
2325  */
2326     static int
2327 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
2328 {
2329     varnumber_T	n;
2330     char_u	numbuf[NUMBUFLEN];
2331     char_u	*s;
2332 
2333     /* Can't do anything with a Funcref, Dict, v:true on the right. */
2334     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
2335 						&& tv2->v_type != VAR_SPECIAL)
2336     {
2337 	switch (tv1->v_type)
2338 	{
2339 	    case VAR_UNKNOWN:
2340 	    case VAR_DICT:
2341 	    case VAR_FUNC:
2342 	    case VAR_PARTIAL:
2343 	    case VAR_SPECIAL:
2344 	    case VAR_JOB:
2345 	    case VAR_CHANNEL:
2346 		break;
2347 
2348 	    case VAR_LIST:
2349 		if (*op != '+' || tv2->v_type != VAR_LIST)
2350 		    break;
2351 		/* List += List */
2352 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
2353 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
2354 		return OK;
2355 
2356 	    case VAR_NUMBER:
2357 	    case VAR_STRING:
2358 		if (tv2->v_type == VAR_LIST)
2359 		    break;
2360 		if (*op == '+' || *op == '-')
2361 		{
2362 		    /* nr += nr  or  nr -= nr*/
2363 		    n = get_tv_number(tv1);
2364 #ifdef FEAT_FLOAT
2365 		    if (tv2->v_type == VAR_FLOAT)
2366 		    {
2367 			float_T f = n;
2368 
2369 			if (*op == '+')
2370 			    f += tv2->vval.v_float;
2371 			else
2372 			    f -= tv2->vval.v_float;
2373 			clear_tv(tv1);
2374 			tv1->v_type = VAR_FLOAT;
2375 			tv1->vval.v_float = f;
2376 		    }
2377 		    else
2378 #endif
2379 		    {
2380 			if (*op == '+')
2381 			    n += get_tv_number(tv2);
2382 			else
2383 			    n -= get_tv_number(tv2);
2384 			clear_tv(tv1);
2385 			tv1->v_type = VAR_NUMBER;
2386 			tv1->vval.v_number = n;
2387 		    }
2388 		}
2389 		else
2390 		{
2391 		    if (tv2->v_type == VAR_FLOAT)
2392 			break;
2393 
2394 		    /* str .= str */
2395 		    s = get_tv_string(tv1);
2396 		    s = concat_str(s, get_tv_string_buf(tv2, numbuf));
2397 		    clear_tv(tv1);
2398 		    tv1->v_type = VAR_STRING;
2399 		    tv1->vval.v_string = s;
2400 		}
2401 		return OK;
2402 
2403 	    case VAR_FLOAT:
2404 #ifdef FEAT_FLOAT
2405 		{
2406 		    float_T f;
2407 
2408 		    if (*op == '.' || (tv2->v_type != VAR_FLOAT
2409 				    && tv2->v_type != VAR_NUMBER
2410 				    && tv2->v_type != VAR_STRING))
2411 			break;
2412 		    if (tv2->v_type == VAR_FLOAT)
2413 			f = tv2->vval.v_float;
2414 		    else
2415 			f = get_tv_number(tv2);
2416 		    if (*op == '+')
2417 			tv1->vval.v_float += f;
2418 		    else
2419 			tv1->vval.v_float -= f;
2420 		}
2421 #endif
2422 		return OK;
2423 	}
2424     }
2425 
2426     EMSG2(_(e_letwrong), op);
2427     return FAIL;
2428 }
2429 
2430 /*
2431  * Evaluate the expression used in a ":for var in expr" command.
2432  * "arg" points to "var".
2433  * Set "*errp" to TRUE for an error, FALSE otherwise;
2434  * Return a pointer that holds the info.  Null when there is an error.
2435  */
2436     void *
2437 eval_for_line(
2438     char_u	*arg,
2439     int		*errp,
2440     char_u	**nextcmdp,
2441     int		skip)
2442 {
2443     forinfo_T	*fi;
2444     char_u	*expr;
2445     typval_T	tv;
2446     list_T	*l;
2447 
2448     *errp = TRUE;	/* default: there is an error */
2449 
2450     fi = (forinfo_T *)alloc_clear(sizeof(forinfo_T));
2451     if (fi == NULL)
2452 	return NULL;
2453 
2454     expr = skip_var_list(arg, &fi->fi_varcount, &fi->fi_semicolon);
2455     if (expr == NULL)
2456 	return fi;
2457 
2458     expr = skipwhite(expr);
2459     if (expr[0] != 'i' || expr[1] != 'n' || !VIM_ISWHITE(expr[2]))
2460     {
2461 	EMSG(_("E690: Missing \"in\" after :for"));
2462 	return fi;
2463     }
2464 
2465     if (skip)
2466 	++emsg_skip;
2467     if (eval0(skipwhite(expr + 2), &tv, nextcmdp, !skip) == OK)
2468     {
2469 	*errp = FALSE;
2470 	if (!skip)
2471 	{
2472 	    l = tv.vval.v_list;
2473 	    if (tv.v_type != VAR_LIST)
2474 	    {
2475 		EMSG(_(e_listreq));
2476 		clear_tv(&tv);
2477 	    }
2478 	    else if (l == NULL)
2479 	    {
2480 		/* a null list is like an empty list: do nothing */
2481 		clear_tv(&tv);
2482 	    }
2483 	    else
2484 	    {
2485 		/* No need to increment the refcount, it's already set for the
2486 		 * list being used in "tv". */
2487 		fi->fi_list = l;
2488 		list_add_watch(l, &fi->fi_lw);
2489 		fi->fi_lw.lw_item = l->lv_first;
2490 	    }
2491 	}
2492     }
2493     if (skip)
2494 	--emsg_skip;
2495 
2496     return fi;
2497 }
2498 
2499 /*
2500  * Use the first item in a ":for" list.  Advance to the next.
2501  * Assign the values to the variable (list).  "arg" points to the first one.
2502  * Return TRUE when a valid item was found, FALSE when at end of list or
2503  * something wrong.
2504  */
2505     int
2506 next_for_item(void *fi_void, char_u *arg)
2507 {
2508     forinfo_T	*fi = (forinfo_T *)fi_void;
2509     int		result;
2510     listitem_T	*item;
2511 
2512     item = fi->fi_lw.lw_item;
2513     if (item == NULL)
2514 	result = FALSE;
2515     else
2516     {
2517 	fi->fi_lw.lw_item = item->li_next;
2518 	result = (ex_let_vars(arg, &item->li_tv, TRUE,
2519 			      fi->fi_semicolon, fi->fi_varcount, NULL) == OK);
2520     }
2521     return result;
2522 }
2523 
2524 /*
2525  * Free the structure used to store info used by ":for".
2526  */
2527     void
2528 free_for_info(void *fi_void)
2529 {
2530     forinfo_T    *fi = (forinfo_T *)fi_void;
2531 
2532     if (fi != NULL && fi->fi_list != NULL)
2533     {
2534 	list_rem_watch(fi->fi_list, &fi->fi_lw);
2535 	list_unref(fi->fi_list);
2536     }
2537     vim_free(fi);
2538 }
2539 
2540 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
2541 
2542     void
2543 set_context_for_expression(
2544     expand_T	*xp,
2545     char_u	*arg,
2546     cmdidx_T	cmdidx)
2547 {
2548     int		got_eq = FALSE;
2549     int		c;
2550     char_u	*p;
2551 
2552     if (cmdidx == CMD_let)
2553     {
2554 	xp->xp_context = EXPAND_USER_VARS;
2555 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
2556 	{
2557 	    /* ":let var1 var2 ...": find last space. */
2558 	    for (p = arg + STRLEN(arg); p >= arg; )
2559 	    {
2560 		xp->xp_pattern = p;
2561 		MB_PTR_BACK(arg, p);
2562 		if (VIM_ISWHITE(*p))
2563 		    break;
2564 	    }
2565 	    return;
2566 	}
2567     }
2568     else
2569 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
2570 							  : EXPAND_EXPRESSION;
2571     while ((xp->xp_pattern = vim_strpbrk(arg,
2572 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
2573     {
2574 	c = *xp->xp_pattern;
2575 	if (c == '&')
2576 	{
2577 	    c = xp->xp_pattern[1];
2578 	    if (c == '&')
2579 	    {
2580 		++xp->xp_pattern;
2581 		xp->xp_context = cmdidx != CMD_let || got_eq
2582 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
2583 	    }
2584 	    else if (c != ' ')
2585 	    {
2586 		xp->xp_context = EXPAND_SETTINGS;
2587 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
2588 		    xp->xp_pattern += 2;
2589 
2590 	    }
2591 	}
2592 	else if (c == '$')
2593 	{
2594 	    /* environment variable */
2595 	    xp->xp_context = EXPAND_ENV_VARS;
2596 	}
2597 	else if (c == '=')
2598 	{
2599 	    got_eq = TRUE;
2600 	    xp->xp_context = EXPAND_EXPRESSION;
2601 	}
2602 	else if (c == '#'
2603 		&& xp->xp_context == EXPAND_EXPRESSION)
2604 	{
2605 	    /* Autoload function/variable contains '#'. */
2606 	    break;
2607 	}
2608 	else if ((c == '<' || c == '#')
2609 		&& xp->xp_context == EXPAND_FUNCTIONS
2610 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
2611 	{
2612 	    /* Function name can start with "<SNR>" and contain '#'. */
2613 	    break;
2614 	}
2615 	else if (cmdidx != CMD_let || got_eq)
2616 	{
2617 	    if (c == '"')	    /* string */
2618 	    {
2619 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
2620 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
2621 			++xp->xp_pattern;
2622 		xp->xp_context = EXPAND_NOTHING;
2623 	    }
2624 	    else if (c == '\'')	    /* literal string */
2625 	    {
2626 		/* Trick: '' is like stopping and starting a literal string. */
2627 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
2628 		    /* skip */ ;
2629 		xp->xp_context = EXPAND_NOTHING;
2630 	    }
2631 	    else if (c == '|')
2632 	    {
2633 		if (xp->xp_pattern[1] == '|')
2634 		{
2635 		    ++xp->xp_pattern;
2636 		    xp->xp_context = EXPAND_EXPRESSION;
2637 		}
2638 		else
2639 		    xp->xp_context = EXPAND_COMMANDS;
2640 	    }
2641 	    else
2642 		xp->xp_context = EXPAND_EXPRESSION;
2643 	}
2644 	else
2645 	    /* Doesn't look like something valid, expand as an expression
2646 	     * anyway. */
2647 	    xp->xp_context = EXPAND_EXPRESSION;
2648 	arg = xp->xp_pattern;
2649 	if (*arg != NUL)
2650 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
2651 		/* skip */ ;
2652     }
2653     xp->xp_pattern = arg;
2654 }
2655 
2656 #endif /* FEAT_CMDL_COMPL */
2657 
2658 /*
2659  * ":unlet[!] var1 ... " command.
2660  */
2661     void
2662 ex_unlet(exarg_T *eap)
2663 {
2664     ex_unletlock(eap, eap->arg, 0);
2665 }
2666 
2667 /*
2668  * ":lockvar" and ":unlockvar" commands
2669  */
2670     void
2671 ex_lockvar(exarg_T *eap)
2672 {
2673     char_u	*arg = eap->arg;
2674     int		deep = 2;
2675 
2676     if (eap->forceit)
2677 	deep = -1;
2678     else if (vim_isdigit(*arg))
2679     {
2680 	deep = getdigits(&arg);
2681 	arg = skipwhite(arg);
2682     }
2683 
2684     ex_unletlock(eap, arg, deep);
2685 }
2686 
2687 /*
2688  * ":unlet", ":lockvar" and ":unlockvar" are quite similar.
2689  */
2690     static void
2691 ex_unletlock(
2692     exarg_T	*eap,
2693     char_u	*argstart,
2694     int		deep)
2695 {
2696     char_u	*arg = argstart;
2697     char_u	*name_end;
2698     int		error = FALSE;
2699     lval_T	lv;
2700 
2701     do
2702     {
2703 	if (*arg == '$')
2704 	{
2705 	    char_u    *name = ++arg;
2706 
2707 	    if (get_env_len(&arg) == 0)
2708 	    {
2709 		EMSG2(_(e_invarg2), name - 1);
2710 		return;
2711 	    }
2712 	    vim_unsetenv(name);
2713 	    arg = skipwhite(arg);
2714 	    continue;
2715 	}
2716 
2717 	/* Parse the name and find the end. */
2718 	name_end = get_lval(arg, NULL, &lv, TRUE, eap->skip || error, 0,
2719 							     FNE_CHECK_START);
2720 	if (lv.ll_name == NULL)
2721 	    error = TRUE;	    /* error but continue parsing */
2722 	if (name_end == NULL || (!VIM_ISWHITE(*name_end)
2723 						   && !ends_excmd(*name_end)))
2724 	{
2725 	    if (name_end != NULL)
2726 	    {
2727 		emsg_severe = TRUE;
2728 		EMSG(_(e_trailing));
2729 	    }
2730 	    if (!(eap->skip || error))
2731 		clear_lval(&lv);
2732 	    break;
2733 	}
2734 
2735 	if (!error && !eap->skip)
2736 	{
2737 	    if (eap->cmdidx == CMD_unlet)
2738 	    {
2739 		if (do_unlet_var(&lv, name_end, eap->forceit) == FAIL)
2740 		    error = TRUE;
2741 	    }
2742 	    else
2743 	    {
2744 		if (do_lock_var(&lv, name_end, deep,
2745 					  eap->cmdidx == CMD_lockvar) == FAIL)
2746 		    error = TRUE;
2747 	    }
2748 	}
2749 
2750 	if (!eap->skip)
2751 	    clear_lval(&lv);
2752 
2753 	arg = skipwhite(name_end);
2754     } while (!ends_excmd(*arg));
2755 
2756     eap->nextcmd = check_nextcmd(arg);
2757 }
2758 
2759     static int
2760 do_unlet_var(
2761     lval_T	*lp,
2762     char_u	*name_end,
2763     int		forceit)
2764 {
2765     int		ret = OK;
2766     int		cc;
2767 
2768     if (lp->ll_tv == NULL)
2769     {
2770 	cc = *name_end;
2771 	*name_end = NUL;
2772 
2773 	/* Normal name or expanded name. */
2774 	if (do_unlet(lp->ll_name, forceit) == FAIL)
2775 	    ret = FAIL;
2776 	*name_end = cc;
2777     }
2778     else if ((lp->ll_list != NULL
2779 		   && tv_check_lock(lp->ll_list->lv_lock, lp->ll_name, FALSE))
2780 	    || (lp->ll_dict != NULL
2781 		  && tv_check_lock(lp->ll_dict->dv_lock, lp->ll_name, FALSE)))
2782 	return FAIL;
2783     else if (lp->ll_range)
2784     {
2785 	listitem_T    *li;
2786 	listitem_T    *ll_li = lp->ll_li;
2787 	int	      ll_n1 = lp->ll_n1;
2788 
2789 	while (ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= ll_n1))
2790 	{
2791 	    li = ll_li->li_next;
2792 	    if (tv_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
2793 		return FAIL;
2794 	    ll_li = li;
2795 	    ++ll_n1;
2796 	}
2797 
2798 	/* Delete a range of List items. */
2799 	while (lp->ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
2800 	{
2801 	    li = lp->ll_li->li_next;
2802 	    listitem_remove(lp->ll_list, lp->ll_li);
2803 	    lp->ll_li = li;
2804 	    ++lp->ll_n1;
2805 	}
2806     }
2807     else
2808     {
2809 	if (lp->ll_list != NULL)
2810 	    /* unlet a List item. */
2811 	    listitem_remove(lp->ll_list, lp->ll_li);
2812 	else
2813 	    /* unlet a Dictionary item. */
2814 	    dictitem_remove(lp->ll_dict, lp->ll_di);
2815     }
2816 
2817     return ret;
2818 }
2819 
2820 /*
2821  * "unlet" a variable.  Return OK if it existed, FAIL if not.
2822  * When "forceit" is TRUE don't complain if the variable doesn't exist.
2823  */
2824     int
2825 do_unlet(char_u *name, int forceit)
2826 {
2827     hashtab_T	*ht;
2828     hashitem_T	*hi;
2829     char_u	*varname;
2830     dict_T	*d;
2831     dictitem_T	*di;
2832 
2833     ht = find_var_ht(name, &varname);
2834     if (ht != NULL && *varname != NUL)
2835     {
2836 	d = get_current_funccal_dict(ht);
2837 	if (d == NULL)
2838 	{
2839 	    if (ht == &globvarht)
2840 		d = &globvardict;
2841 	    else if (ht == &compat_hashtab)
2842 		d = &vimvardict;
2843 	    else
2844 	    {
2845 		di = find_var_in_ht(ht, *name, (char_u *)"", FALSE);
2846 		d = di == NULL ? NULL : di->di_tv.vval.v_dict;
2847 	    }
2848 	    if (d == NULL)
2849 	    {
2850 		internal_error("do_unlet()");
2851 		return FAIL;
2852 	    }
2853 	}
2854 	hi = hash_find(ht, varname);
2855 	if (HASHITEM_EMPTY(hi))
2856 	    hi = find_hi_in_scoped_ht(name, &ht);
2857 	if (hi != NULL && !HASHITEM_EMPTY(hi))
2858 	{
2859 	    di = HI2DI(hi);
2860 	    if (var_check_fixed(di->di_flags, name, FALSE)
2861 		    || var_check_ro(di->di_flags, name, FALSE)
2862 		    || tv_check_lock(d->dv_lock, name, FALSE))
2863 		return FAIL;
2864 
2865 	    delete_var(ht, hi);
2866 	    return OK;
2867 	}
2868     }
2869     if (forceit)
2870 	return OK;
2871     EMSG2(_("E108: No such variable: \"%s\""), name);
2872     return FAIL;
2873 }
2874 
2875 /*
2876  * Lock or unlock variable indicated by "lp".
2877  * "deep" is the levels to go (-1 for unlimited);
2878  * "lock" is TRUE for ":lockvar", FALSE for ":unlockvar".
2879  */
2880     static int
2881 do_lock_var(
2882     lval_T	*lp,
2883     char_u	*name_end,
2884     int		deep,
2885     int		lock)
2886 {
2887     int		ret = OK;
2888     int		cc;
2889     dictitem_T	*di;
2890 
2891     if (deep == 0)	/* nothing to do */
2892 	return OK;
2893 
2894     if (lp->ll_tv == NULL)
2895     {
2896 	cc = *name_end;
2897 	*name_end = NUL;
2898 
2899 	/* Normal name or expanded name. */
2900 	di = find_var(lp->ll_name, NULL, TRUE);
2901 	if (di == NULL)
2902 	    ret = FAIL;
2903 	else if ((di->di_flags & DI_FLAGS_FIX)
2904 			&& di->di_tv.v_type != VAR_DICT
2905 			&& di->di_tv.v_type != VAR_LIST)
2906 	    /* For historic reasons this error is not given for a list or dict.
2907 	     * E.g., the b: dict could be locked/unlocked. */
2908 	    EMSG2(_("E940: Cannot lock or unlock variable %s"), lp->ll_name);
2909 	else
2910 	{
2911 	    if (lock)
2912 		di->di_flags |= DI_FLAGS_LOCK;
2913 	    else
2914 		di->di_flags &= ~DI_FLAGS_LOCK;
2915 	    item_lock(&di->di_tv, deep, lock);
2916 	}
2917 	*name_end = cc;
2918     }
2919     else if (lp->ll_range)
2920     {
2921 	listitem_T    *li = lp->ll_li;
2922 
2923 	/* (un)lock a range of List items. */
2924 	while (li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
2925 	{
2926 	    item_lock(&li->li_tv, deep, lock);
2927 	    li = li->li_next;
2928 	    ++lp->ll_n1;
2929 	}
2930     }
2931     else if (lp->ll_list != NULL)
2932 	/* (un)lock a List item. */
2933 	item_lock(&lp->ll_li->li_tv, deep, lock);
2934     else
2935 	/* (un)lock a Dictionary item. */
2936 	item_lock(&lp->ll_di->di_tv, deep, lock);
2937 
2938     return ret;
2939 }
2940 
2941 /*
2942  * Lock or unlock an item.  "deep" is nr of levels to go.
2943  */
2944     static void
2945 item_lock(typval_T *tv, int deep, int lock)
2946 {
2947     static int	recurse = 0;
2948     list_T	*l;
2949     listitem_T	*li;
2950     dict_T	*d;
2951     hashitem_T	*hi;
2952     int		todo;
2953 
2954     if (recurse >= DICT_MAXNEST)
2955     {
2956 	EMSG(_("E743: variable nested too deep for (un)lock"));
2957 	return;
2958     }
2959     if (deep == 0)
2960 	return;
2961     ++recurse;
2962 
2963     /* lock/unlock the item itself */
2964     if (lock)
2965 	tv->v_lock |= VAR_LOCKED;
2966     else
2967 	tv->v_lock &= ~VAR_LOCKED;
2968 
2969     switch (tv->v_type)
2970     {
2971 	case VAR_UNKNOWN:
2972 	case VAR_NUMBER:
2973 	case VAR_STRING:
2974 	case VAR_FUNC:
2975 	case VAR_PARTIAL:
2976 	case VAR_FLOAT:
2977 	case VAR_SPECIAL:
2978 	case VAR_JOB:
2979 	case VAR_CHANNEL:
2980 	    break;
2981 
2982 	case VAR_LIST:
2983 	    if ((l = tv->vval.v_list) != NULL)
2984 	    {
2985 		if (lock)
2986 		    l->lv_lock |= VAR_LOCKED;
2987 		else
2988 		    l->lv_lock &= ~VAR_LOCKED;
2989 		if (deep < 0 || deep > 1)
2990 		    /* recursive: lock/unlock the items the List contains */
2991 		    for (li = l->lv_first; li != NULL; li = li->li_next)
2992 			item_lock(&li->li_tv, deep - 1, lock);
2993 	    }
2994 	    break;
2995 	case VAR_DICT:
2996 	    if ((d = tv->vval.v_dict) != NULL)
2997 	    {
2998 		if (lock)
2999 		    d->dv_lock |= VAR_LOCKED;
3000 		else
3001 		    d->dv_lock &= ~VAR_LOCKED;
3002 		if (deep < 0 || deep > 1)
3003 		{
3004 		    /* recursive: lock/unlock the items the List contains */
3005 		    todo = (int)d->dv_hashtab.ht_used;
3006 		    for (hi = d->dv_hashtab.ht_array; todo > 0; ++hi)
3007 		    {
3008 			if (!HASHITEM_EMPTY(hi))
3009 			{
3010 			    --todo;
3011 			    item_lock(&HI2DI(hi)->di_tv, deep - 1, lock);
3012 			}
3013 		    }
3014 		}
3015 	    }
3016     }
3017     --recurse;
3018 }
3019 
3020 #if (defined(FEAT_MENU) && defined(FEAT_MULTI_LANG)) || defined(PROTO)
3021 /*
3022  * Delete all "menutrans_" variables.
3023  */
3024     void
3025 del_menutrans_vars(void)
3026 {
3027     hashitem_T	*hi;
3028     int		todo;
3029 
3030     hash_lock(&globvarht);
3031     todo = (int)globvarht.ht_used;
3032     for (hi = globvarht.ht_array; todo > 0 && !got_int; ++hi)
3033     {
3034 	if (!HASHITEM_EMPTY(hi))
3035 	{
3036 	    --todo;
3037 	    if (STRNCMP(HI2DI(hi)->di_key, "menutrans_", 10) == 0)
3038 		delete_var(&globvarht, hi);
3039 	}
3040     }
3041     hash_unlock(&globvarht);
3042 }
3043 #endif
3044 
3045 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
3046 
3047 /*
3048  * Local string buffer for the next two functions to store a variable name
3049  * with its prefix. Allocated in cat_prefix_varname(), freed later in
3050  * get_user_var_name().
3051  */
3052 
3053 static char_u *cat_prefix_varname(int prefix, char_u *name);
3054 
3055 static char_u	*varnamebuf = NULL;
3056 static int	varnamebuflen = 0;
3057 
3058 /*
3059  * Function to concatenate a prefix and a variable name.
3060  */
3061     static char_u *
3062 cat_prefix_varname(int prefix, char_u *name)
3063 {
3064     int		len;
3065 
3066     len = (int)STRLEN(name) + 3;
3067     if (len > varnamebuflen)
3068     {
3069 	vim_free(varnamebuf);
3070 	len += 10;			/* some additional space */
3071 	varnamebuf = alloc(len);
3072 	if (varnamebuf == NULL)
3073 	{
3074 	    varnamebuflen = 0;
3075 	    return NULL;
3076 	}
3077 	varnamebuflen = len;
3078     }
3079     *varnamebuf = prefix;
3080     varnamebuf[1] = ':';
3081     STRCPY(varnamebuf + 2, name);
3082     return varnamebuf;
3083 }
3084 
3085 /*
3086  * Function given to ExpandGeneric() to obtain the list of user defined
3087  * (global/buffer/window/built-in) variable names.
3088  */
3089     char_u *
3090 get_user_var_name(expand_T *xp, int idx)
3091 {
3092     static long_u	gdone;
3093     static long_u	bdone;
3094     static long_u	wdone;
3095     static long_u	tdone;
3096     static int		vidx;
3097     static hashitem_T	*hi;
3098     hashtab_T		*ht;
3099 
3100     if (idx == 0)
3101     {
3102 	gdone = bdone = wdone = vidx = 0;
3103 	tdone = 0;
3104     }
3105 
3106     /* Global variables */
3107     if (gdone < globvarht.ht_used)
3108     {
3109 	if (gdone++ == 0)
3110 	    hi = globvarht.ht_array;
3111 	else
3112 	    ++hi;
3113 	while (HASHITEM_EMPTY(hi))
3114 	    ++hi;
3115 	if (STRNCMP("g:", xp->xp_pattern, 2) == 0)
3116 	    return cat_prefix_varname('g', hi->hi_key);
3117 	return hi->hi_key;
3118     }
3119 
3120     /* b: variables */
3121     ht = &curbuf->b_vars->dv_hashtab;
3122     if (bdone < ht->ht_used)
3123     {
3124 	if (bdone++ == 0)
3125 	    hi = ht->ht_array;
3126 	else
3127 	    ++hi;
3128 	while (HASHITEM_EMPTY(hi))
3129 	    ++hi;
3130 	return cat_prefix_varname('b', hi->hi_key);
3131     }
3132 
3133     /* w: variables */
3134     ht = &curwin->w_vars->dv_hashtab;
3135     if (wdone < ht->ht_used)
3136     {
3137 	if (wdone++ == 0)
3138 	    hi = ht->ht_array;
3139 	else
3140 	    ++hi;
3141 	while (HASHITEM_EMPTY(hi))
3142 	    ++hi;
3143 	return cat_prefix_varname('w', hi->hi_key);
3144     }
3145 
3146     /* t: variables */
3147     ht = &curtab->tp_vars->dv_hashtab;
3148     if (tdone < ht->ht_used)
3149     {
3150 	if (tdone++ == 0)
3151 	    hi = ht->ht_array;
3152 	else
3153 	    ++hi;
3154 	while (HASHITEM_EMPTY(hi))
3155 	    ++hi;
3156 	return cat_prefix_varname('t', hi->hi_key);
3157     }
3158 
3159     /* v: variables */
3160     if (vidx < VV_LEN)
3161 	return cat_prefix_varname('v', (char_u *)vimvars[vidx++].vv_name);
3162 
3163     VIM_CLEAR(varnamebuf);
3164     varnamebuflen = 0;
3165     return NULL;
3166 }
3167 
3168 #endif /* FEAT_CMDL_COMPL */
3169 
3170 /*
3171  * Return TRUE if "pat" matches "text".
3172  * Does not use 'cpo' and always uses 'magic'.
3173  */
3174     static int
3175 pattern_match(char_u *pat, char_u *text, int ic)
3176 {
3177     int		matches = FALSE;
3178     char_u	*save_cpo;
3179     regmatch_T	regmatch;
3180 
3181     /* avoid 'l' flag in 'cpoptions' */
3182     save_cpo = p_cpo;
3183     p_cpo = (char_u *)"";
3184     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
3185     if (regmatch.regprog != NULL)
3186     {
3187 	regmatch.rm_ic = ic;
3188 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
3189 	vim_regfree(regmatch.regprog);
3190     }
3191     p_cpo = save_cpo;
3192     return matches;
3193 }
3194 
3195 /*
3196  * The "evaluate" argument: When FALSE, the argument is only parsed but not
3197  * executed.  The function may return OK, but the rettv will be of type
3198  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
3199  */
3200 
3201 /*
3202  * Handle zero level expression.
3203  * This calls eval1() and handles error message and nextcmd.
3204  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
3205  * Note: "rettv.v_lock" is not set.
3206  * Return OK or FAIL.
3207  */
3208     int
3209 eval0(
3210     char_u	*arg,
3211     typval_T	*rettv,
3212     char_u	**nextcmd,
3213     int		evaluate)
3214 {
3215     int		ret;
3216     char_u	*p;
3217 
3218     p = skipwhite(arg);
3219     ret = eval1(&p, rettv, evaluate);
3220     if (ret == FAIL || !ends_excmd(*p))
3221     {
3222 	if (ret != FAIL)
3223 	    clear_tv(rettv);
3224 	/*
3225 	 * Report the invalid expression unless the expression evaluation has
3226 	 * been cancelled due to an aborting error, an interrupt, or an
3227 	 * exception.
3228 	 */
3229 	if (!aborting())
3230 	    EMSG2(_(e_invexpr2), arg);
3231 	ret = FAIL;
3232     }
3233     if (nextcmd != NULL)
3234 	*nextcmd = check_nextcmd(p);
3235 
3236     return ret;
3237 }
3238 
3239 /*
3240  * Handle top level expression:
3241  *	expr2 ? expr1 : expr1
3242  *
3243  * "arg" must point to the first non-white of the expression.
3244  * "arg" is advanced to the next non-white after the recognized expression.
3245  *
3246  * Note: "rettv.v_lock" is not set.
3247  *
3248  * Return OK or FAIL.
3249  */
3250     int
3251 eval1(char_u **arg, typval_T *rettv, int evaluate)
3252 {
3253     int		result;
3254     typval_T	var2;
3255 
3256     /*
3257      * Get the first variable.
3258      */
3259     if (eval2(arg, rettv, evaluate) == FAIL)
3260 	return FAIL;
3261 
3262     if ((*arg)[0] == '?')
3263     {
3264 	result = FALSE;
3265 	if (evaluate)
3266 	{
3267 	    int		error = FALSE;
3268 
3269 	    if (get_tv_number_chk(rettv, &error) != 0)
3270 		result = TRUE;
3271 	    clear_tv(rettv);
3272 	    if (error)
3273 		return FAIL;
3274 	}
3275 
3276 	/*
3277 	 * Get the second variable.
3278 	 */
3279 	*arg = skipwhite(*arg + 1);
3280 	if (eval1(arg, rettv, evaluate && result) == FAIL) /* recursive! */
3281 	    return FAIL;
3282 
3283 	/*
3284 	 * Check for the ":".
3285 	 */
3286 	if ((*arg)[0] != ':')
3287 	{
3288 	    EMSG(_("E109: Missing ':' after '?'"));
3289 	    if (evaluate && result)
3290 		clear_tv(rettv);
3291 	    return FAIL;
3292 	}
3293 
3294 	/*
3295 	 * Get the third variable.
3296 	 */
3297 	*arg = skipwhite(*arg + 1);
3298 	if (eval1(arg, &var2, evaluate && !result) == FAIL) /* recursive! */
3299 	{
3300 	    if (evaluate && result)
3301 		clear_tv(rettv);
3302 	    return FAIL;
3303 	}
3304 	if (evaluate && !result)
3305 	    *rettv = var2;
3306     }
3307 
3308     return OK;
3309 }
3310 
3311 /*
3312  * Handle first level expression:
3313  *	expr2 || expr2 || expr2	    logical OR
3314  *
3315  * "arg" must point to the first non-white of the expression.
3316  * "arg" is advanced to the next non-white after the recognized expression.
3317  *
3318  * Return OK or FAIL.
3319  */
3320     static int
3321 eval2(char_u **arg, typval_T *rettv, int evaluate)
3322 {
3323     typval_T	var2;
3324     long	result;
3325     int		first;
3326     int		error = FALSE;
3327 
3328     /*
3329      * Get the first variable.
3330      */
3331     if (eval3(arg, rettv, evaluate) == FAIL)
3332 	return FAIL;
3333 
3334     /*
3335      * Repeat until there is no following "||".
3336      */
3337     first = TRUE;
3338     result = FALSE;
3339     while ((*arg)[0] == '|' && (*arg)[1] == '|')
3340     {
3341 	if (evaluate && first)
3342 	{
3343 	    if (get_tv_number_chk(rettv, &error) != 0)
3344 		result = TRUE;
3345 	    clear_tv(rettv);
3346 	    if (error)
3347 		return FAIL;
3348 	    first = FALSE;
3349 	}
3350 
3351 	/*
3352 	 * Get the second variable.
3353 	 */
3354 	*arg = skipwhite(*arg + 2);
3355 	if (eval3(arg, &var2, evaluate && !result) == FAIL)
3356 	    return FAIL;
3357 
3358 	/*
3359 	 * Compute the result.
3360 	 */
3361 	if (evaluate && !result)
3362 	{
3363 	    if (get_tv_number_chk(&var2, &error) != 0)
3364 		result = TRUE;
3365 	    clear_tv(&var2);
3366 	    if (error)
3367 		return FAIL;
3368 	}
3369 	if (evaluate)
3370 	{
3371 	    rettv->v_type = VAR_NUMBER;
3372 	    rettv->vval.v_number = result;
3373 	}
3374     }
3375 
3376     return OK;
3377 }
3378 
3379 /*
3380  * Handle second level expression:
3381  *	expr3 && expr3 && expr3	    logical AND
3382  *
3383  * "arg" must point to the first non-white of the expression.
3384  * "arg" is advanced to the next non-white after the recognized expression.
3385  *
3386  * Return OK or FAIL.
3387  */
3388     static int
3389 eval3(char_u **arg, typval_T *rettv, int evaluate)
3390 {
3391     typval_T	var2;
3392     long	result;
3393     int		first;
3394     int		error = FALSE;
3395 
3396     /*
3397      * Get the first variable.
3398      */
3399     if (eval4(arg, rettv, evaluate) == FAIL)
3400 	return FAIL;
3401 
3402     /*
3403      * Repeat until there is no following "&&".
3404      */
3405     first = TRUE;
3406     result = TRUE;
3407     while ((*arg)[0] == '&' && (*arg)[1] == '&')
3408     {
3409 	if (evaluate && first)
3410 	{
3411 	    if (get_tv_number_chk(rettv, &error) == 0)
3412 		result = FALSE;
3413 	    clear_tv(rettv);
3414 	    if (error)
3415 		return FAIL;
3416 	    first = FALSE;
3417 	}
3418 
3419 	/*
3420 	 * Get the second variable.
3421 	 */
3422 	*arg = skipwhite(*arg + 2);
3423 	if (eval4(arg, &var2, evaluate && result) == FAIL)
3424 	    return FAIL;
3425 
3426 	/*
3427 	 * Compute the result.
3428 	 */
3429 	if (evaluate && result)
3430 	{
3431 	    if (get_tv_number_chk(&var2, &error) == 0)
3432 		result = FALSE;
3433 	    clear_tv(&var2);
3434 	    if (error)
3435 		return FAIL;
3436 	}
3437 	if (evaluate)
3438 	{
3439 	    rettv->v_type = VAR_NUMBER;
3440 	    rettv->vval.v_number = result;
3441 	}
3442     }
3443 
3444     return OK;
3445 }
3446 
3447 /*
3448  * Handle third level expression:
3449  *	var1 == var2
3450  *	var1 =~ var2
3451  *	var1 != var2
3452  *	var1 !~ var2
3453  *	var1 > var2
3454  *	var1 >= var2
3455  *	var1 < var2
3456  *	var1 <= var2
3457  *	var1 is var2
3458  *	var1 isnot var2
3459  *
3460  * "arg" must point to the first non-white of the expression.
3461  * "arg" is advanced to the next non-white after the recognized expression.
3462  *
3463  * Return OK or FAIL.
3464  */
3465     static int
3466 eval4(char_u **arg, typval_T *rettv, int evaluate)
3467 {
3468     typval_T	var2;
3469     char_u	*p;
3470     int		i;
3471     exptype_T	type = TYPE_UNKNOWN;
3472     int		type_is = FALSE;    /* TRUE for "is" and "isnot" */
3473     int		len = 2;
3474     int		ic;
3475 
3476     /*
3477      * Get the first variable.
3478      */
3479     if (eval5(arg, rettv, evaluate) == FAIL)
3480 	return FAIL;
3481 
3482     p = *arg;
3483     switch (p[0])
3484     {
3485 	case '=':   if (p[1] == '=')
3486 			type = TYPE_EQUAL;
3487 		    else if (p[1] == '~')
3488 			type = TYPE_MATCH;
3489 		    break;
3490 	case '!':   if (p[1] == '=')
3491 			type = TYPE_NEQUAL;
3492 		    else if (p[1] == '~')
3493 			type = TYPE_NOMATCH;
3494 		    break;
3495 	case '>':   if (p[1] != '=')
3496 		    {
3497 			type = TYPE_GREATER;
3498 			len = 1;
3499 		    }
3500 		    else
3501 			type = TYPE_GEQUAL;
3502 		    break;
3503 	case '<':   if (p[1] != '=')
3504 		    {
3505 			type = TYPE_SMALLER;
3506 			len = 1;
3507 		    }
3508 		    else
3509 			type = TYPE_SEQUAL;
3510 		    break;
3511 	case 'i':   if (p[1] == 's')
3512 		    {
3513 			if (p[2] == 'n' && p[3] == 'o' && p[4] == 't')
3514 			    len = 5;
3515 			i = p[len];
3516 			if (!isalnum(i) && i != '_')
3517 			{
3518 			    type = len == 2 ? TYPE_EQUAL : TYPE_NEQUAL;
3519 			    type_is = TRUE;
3520 			}
3521 		    }
3522 		    break;
3523     }
3524 
3525     /*
3526      * If there is a comparative operator, use it.
3527      */
3528     if (type != TYPE_UNKNOWN)
3529     {
3530 	/* extra question mark appended: ignore case */
3531 	if (p[len] == '?')
3532 	{
3533 	    ic = TRUE;
3534 	    ++len;
3535 	}
3536 	/* extra '#' appended: match case */
3537 	else if (p[len] == '#')
3538 	{
3539 	    ic = FALSE;
3540 	    ++len;
3541 	}
3542 	/* nothing appended: use 'ignorecase' */
3543 	else
3544 	    ic = p_ic;
3545 
3546 	/*
3547 	 * Get the second variable.
3548 	 */
3549 	*arg = skipwhite(p + len);
3550 	if (eval5(arg, &var2, evaluate) == FAIL)
3551 	{
3552 	    clear_tv(rettv);
3553 	    return FAIL;
3554 	}
3555 	if (evaluate)
3556 	{
3557 	    int ret = typval_compare(rettv, &var2, type, type_is, ic);
3558 
3559 	    clear_tv(&var2);
3560 	    return ret;
3561 	}
3562     }
3563 
3564     return OK;
3565 }
3566 
3567 /*
3568  * Handle fourth level expression:
3569  *	+	number addition
3570  *	-	number subtraction
3571  *	.	string concatenation
3572  *
3573  * "arg" must point to the first non-white of the expression.
3574  * "arg" is advanced to the next non-white after the recognized expression.
3575  *
3576  * Return OK or FAIL.
3577  */
3578     static int
3579 eval5(char_u **arg, typval_T *rettv, int evaluate)
3580 {
3581     typval_T	var2;
3582     typval_T	var3;
3583     int		op;
3584     varnumber_T	n1, n2;
3585 #ifdef FEAT_FLOAT
3586     float_T	f1 = 0, f2 = 0;
3587 #endif
3588     char_u	*s1, *s2;
3589     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3590     char_u	*p;
3591 
3592     /*
3593      * Get the first variable.
3594      */
3595     if (eval6(arg, rettv, evaluate, FALSE) == FAIL)
3596 	return FAIL;
3597 
3598     /*
3599      * Repeat computing, until no '+', '-' or '.' is following.
3600      */
3601     for (;;)
3602     {
3603 	op = **arg;
3604 	if (op != '+' && op != '-' && op != '.')
3605 	    break;
3606 
3607 	if ((op != '+' || rettv->v_type != VAR_LIST)
3608 #ifdef FEAT_FLOAT
3609 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
3610 #endif
3611 		)
3612 	{
3613 	    /* For "list + ...", an illegal use of the first operand as
3614 	     * a number cannot be determined before evaluating the 2nd
3615 	     * operand: if this is also a list, all is ok.
3616 	     * For "something . ...", "something - ..." or "non-list + ...",
3617 	     * we know that the first operand needs to be a string or number
3618 	     * without evaluating the 2nd operand.  So check before to avoid
3619 	     * side effects after an error. */
3620 	    if (evaluate && get_tv_string_chk(rettv) == NULL)
3621 	    {
3622 		clear_tv(rettv);
3623 		return FAIL;
3624 	    }
3625 	}
3626 
3627 	/*
3628 	 * Get the second variable.
3629 	 */
3630 	*arg = skipwhite(*arg + 1);
3631 	if (eval6(arg, &var2, evaluate, op == '.') == FAIL)
3632 	{
3633 	    clear_tv(rettv);
3634 	    return FAIL;
3635 	}
3636 
3637 	if (evaluate)
3638 	{
3639 	    /*
3640 	     * Compute the result.
3641 	     */
3642 	    if (op == '.')
3643 	    {
3644 		s1 = get_tv_string_buf(rettv, buf1);	/* already checked */
3645 		s2 = get_tv_string_buf_chk(&var2, buf2);
3646 		if (s2 == NULL)		/* type error ? */
3647 		{
3648 		    clear_tv(rettv);
3649 		    clear_tv(&var2);
3650 		    return FAIL;
3651 		}
3652 		p = concat_str(s1, s2);
3653 		clear_tv(rettv);
3654 		rettv->v_type = VAR_STRING;
3655 		rettv->vval.v_string = p;
3656 	    }
3657 	    else if (op == '+' && rettv->v_type == VAR_LIST
3658 						   && var2.v_type == VAR_LIST)
3659 	    {
3660 		/* concatenate Lists */
3661 		if (list_concat(rettv->vval.v_list, var2.vval.v_list,
3662 							       &var3) == FAIL)
3663 		{
3664 		    clear_tv(rettv);
3665 		    clear_tv(&var2);
3666 		    return FAIL;
3667 		}
3668 		clear_tv(rettv);
3669 		*rettv = var3;
3670 	    }
3671 	    else
3672 	    {
3673 		int	    error = FALSE;
3674 
3675 #ifdef FEAT_FLOAT
3676 		if (rettv->v_type == VAR_FLOAT)
3677 		{
3678 		    f1 = rettv->vval.v_float;
3679 		    n1 = 0;
3680 		}
3681 		else
3682 #endif
3683 		{
3684 		    n1 = get_tv_number_chk(rettv, &error);
3685 		    if (error)
3686 		    {
3687 			/* This can only happen for "list + non-list".  For
3688 			 * "non-list + ..." or "something - ...", we returned
3689 			 * before evaluating the 2nd operand. */
3690 			clear_tv(rettv);
3691 			return FAIL;
3692 		    }
3693 #ifdef FEAT_FLOAT
3694 		    if (var2.v_type == VAR_FLOAT)
3695 			f1 = n1;
3696 #endif
3697 		}
3698 #ifdef FEAT_FLOAT
3699 		if (var2.v_type == VAR_FLOAT)
3700 		{
3701 		    f2 = var2.vval.v_float;
3702 		    n2 = 0;
3703 		}
3704 		else
3705 #endif
3706 		{
3707 		    n2 = get_tv_number_chk(&var2, &error);
3708 		    if (error)
3709 		    {
3710 			clear_tv(rettv);
3711 			clear_tv(&var2);
3712 			return FAIL;
3713 		    }
3714 #ifdef FEAT_FLOAT
3715 		    if (rettv->v_type == VAR_FLOAT)
3716 			f2 = n2;
3717 #endif
3718 		}
3719 		clear_tv(rettv);
3720 
3721 #ifdef FEAT_FLOAT
3722 		/* If there is a float on either side the result is a float. */
3723 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3724 		{
3725 		    if (op == '+')
3726 			f1 = f1 + f2;
3727 		    else
3728 			f1 = f1 - f2;
3729 		    rettv->v_type = VAR_FLOAT;
3730 		    rettv->vval.v_float = f1;
3731 		}
3732 		else
3733 #endif
3734 		{
3735 		    if (op == '+')
3736 			n1 = n1 + n2;
3737 		    else
3738 			n1 = n1 - n2;
3739 		    rettv->v_type = VAR_NUMBER;
3740 		    rettv->vval.v_number = n1;
3741 		}
3742 	    }
3743 	    clear_tv(&var2);
3744 	}
3745     }
3746     return OK;
3747 }
3748 
3749 /*
3750  * Handle fifth level expression:
3751  *	*	number multiplication
3752  *	/	number division
3753  *	%	number modulo
3754  *
3755  * "arg" must point to the first non-white of the expression.
3756  * "arg" is advanced to the next non-white after the recognized expression.
3757  *
3758  * Return OK or FAIL.
3759  */
3760     static int
3761 eval6(
3762     char_u	**arg,
3763     typval_T	*rettv,
3764     int		evaluate,
3765     int		want_string)  /* after "." operator */
3766 {
3767     typval_T	var2;
3768     int		op;
3769     varnumber_T	n1, n2;
3770 #ifdef FEAT_FLOAT
3771     int		use_float = FALSE;
3772     float_T	f1 = 0, f2;
3773 #endif
3774     int		error = FALSE;
3775 
3776     /*
3777      * Get the first variable.
3778      */
3779     if (eval7(arg, rettv, evaluate, want_string) == FAIL)
3780 	return FAIL;
3781 
3782     /*
3783      * Repeat computing, until no '*', '/' or '%' is following.
3784      */
3785     for (;;)
3786     {
3787 	op = **arg;
3788 	if (op != '*' && op != '/' && op != '%')
3789 	    break;
3790 
3791 	if (evaluate)
3792 	{
3793 #ifdef FEAT_FLOAT
3794 	    if (rettv->v_type == VAR_FLOAT)
3795 	    {
3796 		f1 = rettv->vval.v_float;
3797 		use_float = TRUE;
3798 		n1 = 0;
3799 	    }
3800 	    else
3801 #endif
3802 		n1 = get_tv_number_chk(rettv, &error);
3803 	    clear_tv(rettv);
3804 	    if (error)
3805 		return FAIL;
3806 	}
3807 	else
3808 	    n1 = 0;
3809 
3810 	/*
3811 	 * Get the second variable.
3812 	 */
3813 	*arg = skipwhite(*arg + 1);
3814 	if (eval7(arg, &var2, evaluate, FALSE) == FAIL)
3815 	    return FAIL;
3816 
3817 	if (evaluate)
3818 	{
3819 #ifdef FEAT_FLOAT
3820 	    if (var2.v_type == VAR_FLOAT)
3821 	    {
3822 		if (!use_float)
3823 		{
3824 		    f1 = n1;
3825 		    use_float = TRUE;
3826 		}
3827 		f2 = var2.vval.v_float;
3828 		n2 = 0;
3829 	    }
3830 	    else
3831 #endif
3832 	    {
3833 		n2 = get_tv_number_chk(&var2, &error);
3834 		clear_tv(&var2);
3835 		if (error)
3836 		    return FAIL;
3837 #ifdef FEAT_FLOAT
3838 		if (use_float)
3839 		    f2 = n2;
3840 #endif
3841 	    }
3842 
3843 	    /*
3844 	     * Compute the result.
3845 	     * When either side is a float the result is a float.
3846 	     */
3847 #ifdef FEAT_FLOAT
3848 	    if (use_float)
3849 	    {
3850 		if (op == '*')
3851 		    f1 = f1 * f2;
3852 		else if (op == '/')
3853 		{
3854 # ifdef VMS
3855 		    /* VMS crashes on divide by zero, work around it */
3856 		    if (f2 == 0.0)
3857 		    {
3858 			if (f1 == 0)
3859 			    f1 = -1 * __F_FLT_MAX - 1L;   /* similar to NaN */
3860 			else if (f1 < 0)
3861 			    f1 = -1 * __F_FLT_MAX;
3862 			else
3863 			    f1 = __F_FLT_MAX;
3864 		    }
3865 		    else
3866 			f1 = f1 / f2;
3867 # else
3868 		    /* We rely on the floating point library to handle divide
3869 		     * by zero to result in "inf" and not a crash. */
3870 		    f1 = f1 / f2;
3871 # endif
3872 		}
3873 		else
3874 		{
3875 		    EMSG(_("E804: Cannot use '%' with Float"));
3876 		    return FAIL;
3877 		}
3878 		rettv->v_type = VAR_FLOAT;
3879 		rettv->vval.v_float = f1;
3880 	    }
3881 	    else
3882 #endif
3883 	    {
3884 		if (op == '*')
3885 		    n1 = n1 * n2;
3886 		else if (op == '/')
3887 		{
3888 		    if (n2 == 0)	/* give an error message? */
3889 		    {
3890 			if (n1 == 0)
3891 			    n1 = VARNUM_MIN; /* similar to NaN */
3892 			else if (n1 < 0)
3893 			    n1 = -VARNUM_MAX;
3894 			else
3895 			    n1 = VARNUM_MAX;
3896 		    }
3897 		    else
3898 			n1 = n1 / n2;
3899 		}
3900 		else
3901 		{
3902 		    if (n2 == 0)	/* give an error message? */
3903 			n1 = 0;
3904 		    else
3905 			n1 = n1 % n2;
3906 		}
3907 		rettv->v_type = VAR_NUMBER;
3908 		rettv->vval.v_number = n1;
3909 	    }
3910 	}
3911     }
3912 
3913     return OK;
3914 }
3915 
3916 /*
3917  * Handle sixth level expression:
3918  *  number		number constant
3919  *  "string"		string constant
3920  *  'string'		literal string constant
3921  *  &option-name	option value
3922  *  @r			register contents
3923  *  identifier		variable value
3924  *  function()		function call
3925  *  $VAR		environment variable
3926  *  (expression)	nested expression
3927  *  [expr, expr]	List
3928  *  {key: val, key: val}  Dictionary
3929  *
3930  *  Also handle:
3931  *  ! in front		logical NOT
3932  *  - in front		unary minus
3933  *  + in front		unary plus (ignored)
3934  *  trailing []		subscript in String or List
3935  *  trailing .name	entry in Dictionary
3936  *
3937  * "arg" must point to the first non-white of the expression.
3938  * "arg" is advanced to the next non-white after the recognized expression.
3939  *
3940  * Return OK or FAIL.
3941  */
3942     static int
3943 eval7(
3944     char_u	**arg,
3945     typval_T	*rettv,
3946     int		evaluate,
3947     int		want_string UNUSED)	/* after "." operator */
3948 {
3949     varnumber_T	n;
3950     int		len;
3951     char_u	*s;
3952     char_u	*start_leader, *end_leader;
3953     int		ret = OK;
3954     char_u	*alias;
3955 
3956     /*
3957      * Initialise variable so that clear_tv() can't mistake this for a
3958      * string and free a string that isn't there.
3959      */
3960     rettv->v_type = VAR_UNKNOWN;
3961 
3962     /*
3963      * Skip '!', '-' and '+' characters.  They are handled later.
3964      */
3965     start_leader = *arg;
3966     while (**arg == '!' || **arg == '-' || **arg == '+')
3967 	*arg = skipwhite(*arg + 1);
3968     end_leader = *arg;
3969 
3970     switch (**arg)
3971     {
3972     /*
3973      * Number constant.
3974      */
3975     case '0':
3976     case '1':
3977     case '2':
3978     case '3':
3979     case '4':
3980     case '5':
3981     case '6':
3982     case '7':
3983     case '8':
3984     case '9':
3985 	{
3986 #ifdef FEAT_FLOAT
3987 		char_u *p = skipdigits(*arg + 1);
3988 		int    get_float = FALSE;
3989 
3990 		/* We accept a float when the format matches
3991 		 * "[0-9]\+\.[0-9]\+\([eE][+-]\?[0-9]\+\)\?".  This is very
3992 		 * strict to avoid backwards compatibility problems.
3993 		 * Don't look for a float after the "." operator, so that
3994 		 * ":let vers = 1.2.3" doesn't fail. */
3995 		if (!want_string && p[0] == '.' && vim_isdigit(p[1]))
3996 		{
3997 		    get_float = TRUE;
3998 		    p = skipdigits(p + 2);
3999 		    if (*p == 'e' || *p == 'E')
4000 		    {
4001 			++p;
4002 			if (*p == '-' || *p == '+')
4003 			    ++p;
4004 			if (!vim_isdigit(*p))
4005 			    get_float = FALSE;
4006 			else
4007 			    p = skipdigits(p + 1);
4008 		    }
4009 		    if (ASCII_ISALPHA(*p) || *p == '.')
4010 			get_float = FALSE;
4011 		}
4012 		if (get_float)
4013 		{
4014 		    float_T	f;
4015 
4016 		    *arg += string2float(*arg, &f);
4017 		    if (evaluate)
4018 		    {
4019 			rettv->v_type = VAR_FLOAT;
4020 			rettv->vval.v_float = f;
4021 		    }
4022 		}
4023 		else
4024 #endif
4025 		{
4026 		    vim_str2nr(*arg, NULL, &len, STR2NR_ALL, &n, NULL, 0);
4027 		    *arg += len;
4028 		    if (evaluate)
4029 		    {
4030 			rettv->v_type = VAR_NUMBER;
4031 			rettv->vval.v_number = n;
4032 		    }
4033 		}
4034 		break;
4035 	}
4036 
4037     /*
4038      * String constant: "string".
4039      */
4040     case '"':	ret = get_string_tv(arg, rettv, evaluate);
4041 		break;
4042 
4043     /*
4044      * Literal string constant: 'str''ing'.
4045      */
4046     case '\'':	ret = get_lit_string_tv(arg, rettv, evaluate);
4047 		break;
4048 
4049     /*
4050      * List: [expr, expr]
4051      */
4052     case '[':	ret = get_list_tv(arg, rettv, evaluate);
4053 		break;
4054 
4055     /*
4056      * Lambda: {arg, arg -> expr}
4057      * Dictionary: {key: val, key: val}
4058      */
4059     case '{':	ret = get_lambda_tv(arg, rettv, evaluate);
4060 		if (ret == NOTDONE)
4061 		    ret = get_dict_tv(arg, rettv, evaluate);
4062 		break;
4063 
4064     /*
4065      * Option value: &name
4066      */
4067     case '&':	ret = get_option_tv(arg, rettv, evaluate);
4068 		break;
4069 
4070     /*
4071      * Environment variable: $VAR.
4072      */
4073     case '$':	ret = get_env_tv(arg, rettv, evaluate);
4074 		break;
4075 
4076     /*
4077      * Register contents: @r.
4078      */
4079     case '@':	++*arg;
4080 		if (evaluate)
4081 		{
4082 		    rettv->v_type = VAR_STRING;
4083 		    rettv->vval.v_string = get_reg_contents(**arg,
4084 							    GREG_EXPR_SRC);
4085 		}
4086 		if (**arg != NUL)
4087 		    ++*arg;
4088 		break;
4089 
4090     /*
4091      * nested expression: (expression).
4092      */
4093     case '(':	*arg = skipwhite(*arg + 1);
4094 		ret = eval1(arg, rettv, evaluate);	/* recursive! */
4095 		if (**arg == ')')
4096 		    ++*arg;
4097 		else if (ret == OK)
4098 		{
4099 		    EMSG(_("E110: Missing ')'"));
4100 		    clear_tv(rettv);
4101 		    ret = FAIL;
4102 		}
4103 		break;
4104 
4105     default:	ret = NOTDONE;
4106 		break;
4107     }
4108 
4109     if (ret == NOTDONE)
4110     {
4111 	/*
4112 	 * Must be a variable or function name.
4113 	 * Can also be a curly-braces kind of name: {expr}.
4114 	 */
4115 	s = *arg;
4116 	len = get_name_len(arg, &alias, evaluate, TRUE);
4117 	if (alias != NULL)
4118 	    s = alias;
4119 
4120 	if (len <= 0)
4121 	    ret = FAIL;
4122 	else
4123 	{
4124 	    if (**arg == '(')		/* recursive! */
4125 	    {
4126 		partial_T *partial;
4127 
4128 		if (!evaluate)
4129 		    check_vars(s, len);
4130 
4131 		/* If "s" is the name of a variable of type VAR_FUNC
4132 		 * use its contents. */
4133 		s = deref_func_name(s, &len, &partial, !evaluate);
4134 
4135 		/* Need to make a copy, in case evaluating the arguments makes
4136 		 * the name invalid. */
4137 		s = vim_strsave(s);
4138 		if (s == NULL)
4139 		    ret = FAIL;
4140 		else
4141 		    /* Invoke the function. */
4142 		    ret = get_func_tv(s, len, rettv, arg,
4143 			      curwin->w_cursor.lnum, curwin->w_cursor.lnum,
4144 			      &len, evaluate, partial, NULL);
4145 		vim_free(s);
4146 
4147 		/* If evaluate is FALSE rettv->v_type was not set in
4148 		 * get_func_tv, but it's needed in handle_subscript() to parse
4149 		 * what follows. So set it here. */
4150 		if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
4151 		{
4152 		    rettv->vval.v_string = NULL;
4153 		    rettv->v_type = VAR_FUNC;
4154 		}
4155 
4156 		/* Stop the expression evaluation when immediately
4157 		 * aborting on error, or when an interrupt occurred or
4158 		 * an exception was thrown but not caught. */
4159 		if (aborting())
4160 		{
4161 		    if (ret == OK)
4162 			clear_tv(rettv);
4163 		    ret = FAIL;
4164 		}
4165 	    }
4166 	    else if (evaluate)
4167 		ret = get_var_tv(s, len, rettv, NULL, TRUE, FALSE);
4168 	    else
4169 	    {
4170 		check_vars(s, len);
4171 		ret = OK;
4172 	    }
4173 	}
4174 	vim_free(alias);
4175     }
4176 
4177     *arg = skipwhite(*arg);
4178 
4179     /* Handle following '[', '(' and '.' for expr[expr], expr.name,
4180      * expr(expr). */
4181     if (ret == OK)
4182 	ret = handle_subscript(arg, rettv, evaluate, TRUE);
4183 
4184     /*
4185      * Apply logical NOT and unary '-', from right to left, ignore '+'.
4186      */
4187     if (ret == OK && evaluate && end_leader > start_leader)
4188     {
4189 	int	    error = FALSE;
4190 	varnumber_T val = 0;
4191 #ifdef FEAT_FLOAT
4192 	float_T	    f = 0.0;
4193 
4194 	if (rettv->v_type == VAR_FLOAT)
4195 	    f = rettv->vval.v_float;
4196 	else
4197 #endif
4198 	    val = get_tv_number_chk(rettv, &error);
4199 	if (error)
4200 	{
4201 	    clear_tv(rettv);
4202 	    ret = FAIL;
4203 	}
4204 	else
4205 	{
4206 	    while (end_leader > start_leader)
4207 	    {
4208 		--end_leader;
4209 		if (*end_leader == '!')
4210 		{
4211 #ifdef FEAT_FLOAT
4212 		    if (rettv->v_type == VAR_FLOAT)
4213 			f = !f;
4214 		    else
4215 #endif
4216 			val = !val;
4217 		}
4218 		else if (*end_leader == '-')
4219 		{
4220 #ifdef FEAT_FLOAT
4221 		    if (rettv->v_type == VAR_FLOAT)
4222 			f = -f;
4223 		    else
4224 #endif
4225 			val = -val;
4226 		}
4227 	    }
4228 #ifdef FEAT_FLOAT
4229 	    if (rettv->v_type == VAR_FLOAT)
4230 	    {
4231 		clear_tv(rettv);
4232 		rettv->vval.v_float = f;
4233 	    }
4234 	    else
4235 #endif
4236 	    {
4237 		clear_tv(rettv);
4238 		rettv->v_type = VAR_NUMBER;
4239 		rettv->vval.v_number = val;
4240 	    }
4241 	}
4242     }
4243 
4244     return ret;
4245 }
4246 
4247 /*
4248  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
4249  * "*arg" points to the '[' or '.'.
4250  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
4251  */
4252     static int
4253 eval_index(
4254     char_u	**arg,
4255     typval_T	*rettv,
4256     int		evaluate,
4257     int		verbose)	/* give error messages */
4258 {
4259     int		empty1 = FALSE, empty2 = FALSE;
4260     typval_T	var1, var2;
4261     long	n1, n2 = 0;
4262     long	len = -1;
4263     int		range = FALSE;
4264     char_u	*s;
4265     char_u	*key = NULL;
4266 
4267     switch (rettv->v_type)
4268     {
4269 	case VAR_FUNC:
4270 	case VAR_PARTIAL:
4271 	    if (verbose)
4272 		EMSG(_("E695: Cannot index a Funcref"));
4273 	    return FAIL;
4274 	case VAR_FLOAT:
4275 #ifdef FEAT_FLOAT
4276 	    if (verbose)
4277 		EMSG(_(e_float_as_string));
4278 	    return FAIL;
4279 #endif
4280 	case VAR_SPECIAL:
4281 	case VAR_JOB:
4282 	case VAR_CHANNEL:
4283 	    if (verbose)
4284 		EMSG(_("E909: Cannot index a special variable"));
4285 	    return FAIL;
4286 	case VAR_UNKNOWN:
4287 	    if (evaluate)
4288 		return FAIL;
4289 	    /* FALLTHROUGH */
4290 
4291 	case VAR_STRING:
4292 	case VAR_NUMBER:
4293 	case VAR_LIST:
4294 	case VAR_DICT:
4295 	    break;
4296     }
4297 
4298     init_tv(&var1);
4299     init_tv(&var2);
4300     if (**arg == '.')
4301     {
4302 	/*
4303 	 * dict.name
4304 	 */
4305 	key = *arg + 1;
4306 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
4307 	    ;
4308 	if (len == 0)
4309 	    return FAIL;
4310 	*arg = skipwhite(key + len);
4311     }
4312     else
4313     {
4314 	/*
4315 	 * something[idx]
4316 	 *
4317 	 * Get the (first) variable from inside the [].
4318 	 */
4319 	*arg = skipwhite(*arg + 1);
4320 	if (**arg == ':')
4321 	    empty1 = TRUE;
4322 	else if (eval1(arg, &var1, evaluate) == FAIL)	/* recursive! */
4323 	    return FAIL;
4324 	else if (evaluate && get_tv_string_chk(&var1) == NULL)
4325 	{
4326 	    /* not a number or string */
4327 	    clear_tv(&var1);
4328 	    return FAIL;
4329 	}
4330 
4331 	/*
4332 	 * Get the second variable from inside the [:].
4333 	 */
4334 	if (**arg == ':')
4335 	{
4336 	    range = TRUE;
4337 	    *arg = skipwhite(*arg + 1);
4338 	    if (**arg == ']')
4339 		empty2 = TRUE;
4340 	    else if (eval1(arg, &var2, evaluate) == FAIL)	/* recursive! */
4341 	    {
4342 		if (!empty1)
4343 		    clear_tv(&var1);
4344 		return FAIL;
4345 	    }
4346 	    else if (evaluate && get_tv_string_chk(&var2) == NULL)
4347 	    {
4348 		/* not a number or string */
4349 		if (!empty1)
4350 		    clear_tv(&var1);
4351 		clear_tv(&var2);
4352 		return FAIL;
4353 	    }
4354 	}
4355 
4356 	/* Check for the ']'. */
4357 	if (**arg != ']')
4358 	{
4359 	    if (verbose)
4360 		EMSG(_(e_missbrac));
4361 	    clear_tv(&var1);
4362 	    if (range)
4363 		clear_tv(&var2);
4364 	    return FAIL;
4365 	}
4366 	*arg = skipwhite(*arg + 1);	/* skip the ']' */
4367     }
4368 
4369     if (evaluate)
4370     {
4371 	n1 = 0;
4372 	if (!empty1 && rettv->v_type != VAR_DICT)
4373 	{
4374 	    n1 = get_tv_number(&var1);
4375 	    clear_tv(&var1);
4376 	}
4377 	if (range)
4378 	{
4379 	    if (empty2)
4380 		n2 = -1;
4381 	    else
4382 	    {
4383 		n2 = get_tv_number(&var2);
4384 		clear_tv(&var2);
4385 	    }
4386 	}
4387 
4388 	switch (rettv->v_type)
4389 	{
4390 	    case VAR_UNKNOWN:
4391 	    case VAR_FUNC:
4392 	    case VAR_PARTIAL:
4393 	    case VAR_FLOAT:
4394 	    case VAR_SPECIAL:
4395 	    case VAR_JOB:
4396 	    case VAR_CHANNEL:
4397 		break; /* not evaluating, skipping over subscript */
4398 
4399 	    case VAR_NUMBER:
4400 	    case VAR_STRING:
4401 		s = get_tv_string(rettv);
4402 		len = (long)STRLEN(s);
4403 		if (range)
4404 		{
4405 		    /* The resulting variable is a substring.  If the indexes
4406 		     * are out of range the result is empty. */
4407 		    if (n1 < 0)
4408 		    {
4409 			n1 = len + n1;
4410 			if (n1 < 0)
4411 			    n1 = 0;
4412 		    }
4413 		    if (n2 < 0)
4414 			n2 = len + n2;
4415 		    else if (n2 >= len)
4416 			n2 = len;
4417 		    if (n1 >= len || n2 < 0 || n1 > n2)
4418 			s = NULL;
4419 		    else
4420 			s = vim_strnsave(s + n1, (int)(n2 - n1 + 1));
4421 		}
4422 		else
4423 		{
4424 		    /* The resulting variable is a string of a single
4425 		     * character.  If the index is too big or negative the
4426 		     * result is empty. */
4427 		    if (n1 >= len || n1 < 0)
4428 			s = NULL;
4429 		    else
4430 			s = vim_strnsave(s + n1, 1);
4431 		}
4432 		clear_tv(rettv);
4433 		rettv->v_type = VAR_STRING;
4434 		rettv->vval.v_string = s;
4435 		break;
4436 
4437 	    case VAR_LIST:
4438 		len = list_len(rettv->vval.v_list);
4439 		if (n1 < 0)
4440 		    n1 = len + n1;
4441 		if (!empty1 && (n1 < 0 || n1 >= len))
4442 		{
4443 		    /* For a range we allow invalid values and return an empty
4444 		     * list.  A list index out of range is an error. */
4445 		    if (!range)
4446 		    {
4447 			if (verbose)
4448 			    EMSGN(_(e_listidx), n1);
4449 			return FAIL;
4450 		    }
4451 		    n1 = len;
4452 		}
4453 		if (range)
4454 		{
4455 		    list_T	*l;
4456 		    listitem_T	*item;
4457 
4458 		    if (n2 < 0)
4459 			n2 = len + n2;
4460 		    else if (n2 >= len)
4461 			n2 = len - 1;
4462 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
4463 			n2 = -1;
4464 		    l = list_alloc();
4465 		    if (l == NULL)
4466 			return FAIL;
4467 		    for (item = list_find(rettv->vval.v_list, n1);
4468 							       n1 <= n2; ++n1)
4469 		    {
4470 			if (list_append_tv(l, &item->li_tv) == FAIL)
4471 			{
4472 			    list_free(l);
4473 			    return FAIL;
4474 			}
4475 			item = item->li_next;
4476 		    }
4477 		    clear_tv(rettv);
4478 		    rettv_list_set(rettv, l);
4479 		}
4480 		else
4481 		{
4482 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
4483 		    clear_tv(rettv);
4484 		    *rettv = var1;
4485 		}
4486 		break;
4487 
4488 	    case VAR_DICT:
4489 		if (range)
4490 		{
4491 		    if (verbose)
4492 			EMSG(_(e_dictrange));
4493 		    if (len == -1)
4494 			clear_tv(&var1);
4495 		    return FAIL;
4496 		}
4497 		{
4498 		    dictitem_T	*item;
4499 
4500 		    if (len == -1)
4501 		    {
4502 			key = get_tv_string_chk(&var1);
4503 			if (key == NULL)
4504 			{
4505 			    clear_tv(&var1);
4506 			    return FAIL;
4507 			}
4508 		    }
4509 
4510 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
4511 
4512 		    if (item == NULL && verbose)
4513 			EMSG2(_(e_dictkey), key);
4514 		    if (len == -1)
4515 			clear_tv(&var1);
4516 		    if (item == NULL)
4517 			return FAIL;
4518 
4519 		    copy_tv(&item->di_tv, &var1);
4520 		    clear_tv(rettv);
4521 		    *rettv = var1;
4522 		}
4523 		break;
4524 	}
4525     }
4526 
4527     return OK;
4528 }
4529 
4530 /*
4531  * Get an option value.
4532  * "arg" points to the '&' or '+' before the option name.
4533  * "arg" is advanced to character after the option name.
4534  * Return OK or FAIL.
4535  */
4536     int
4537 get_option_tv(
4538     char_u	**arg,
4539     typval_T	*rettv,	/* when NULL, only check if option exists */
4540     int		evaluate)
4541 {
4542     char_u	*option_end;
4543     long	numval;
4544     char_u	*stringval;
4545     int		opt_type;
4546     int		c;
4547     int		working = (**arg == '+');    /* has("+option") */
4548     int		ret = OK;
4549     int		opt_flags;
4550 
4551     /*
4552      * Isolate the option name and find its value.
4553      */
4554     option_end = find_option_end(arg, &opt_flags);
4555     if (option_end == NULL)
4556     {
4557 	if (rettv != NULL)
4558 	    EMSG2(_("E112: Option name missing: %s"), *arg);
4559 	return FAIL;
4560     }
4561 
4562     if (!evaluate)
4563     {
4564 	*arg = option_end;
4565 	return OK;
4566     }
4567 
4568     c = *option_end;
4569     *option_end = NUL;
4570     opt_type = get_option_value(*arg, &numval,
4571 			       rettv == NULL ? NULL : &stringval, opt_flags);
4572 
4573     if (opt_type == -3)			/* invalid name */
4574     {
4575 	if (rettv != NULL)
4576 	    EMSG2(_("E113: Unknown option: %s"), *arg);
4577 	ret = FAIL;
4578     }
4579     else if (rettv != NULL)
4580     {
4581 	if (opt_type == -2)		/* hidden string option */
4582 	{
4583 	    rettv->v_type = VAR_STRING;
4584 	    rettv->vval.v_string = NULL;
4585 	}
4586 	else if (opt_type == -1)	/* hidden number option */
4587 	{
4588 	    rettv->v_type = VAR_NUMBER;
4589 	    rettv->vval.v_number = 0;
4590 	}
4591 	else if (opt_type == 1)		/* number option */
4592 	{
4593 	    rettv->v_type = VAR_NUMBER;
4594 	    rettv->vval.v_number = numval;
4595 	}
4596 	else				/* string option */
4597 	{
4598 	    rettv->v_type = VAR_STRING;
4599 	    rettv->vval.v_string = stringval;
4600 	}
4601     }
4602     else if (working && (opt_type == -2 || opt_type == -1))
4603 	ret = FAIL;
4604 
4605     *option_end = c;		    /* put back for error messages */
4606     *arg = option_end;
4607 
4608     return ret;
4609 }
4610 
4611 /*
4612  * Allocate a variable for a string constant.
4613  * Return OK or FAIL.
4614  */
4615     static int
4616 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
4617 {
4618     char_u	*p;
4619     char_u	*name;
4620     int		extra = 0;
4621 
4622     /*
4623      * Find the end of the string, skipping backslashed characters.
4624      */
4625     for (p = *arg + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
4626     {
4627 	if (*p == '\\' && p[1] != NUL)
4628 	{
4629 	    ++p;
4630 	    /* A "\<x>" form occupies at least 4 characters, and produces up
4631 	     * to 6 characters: reserve space for 2 extra */
4632 	    if (*p == '<')
4633 		extra += 2;
4634 	}
4635     }
4636 
4637     if (*p != '"')
4638     {
4639 	EMSG2(_("E114: Missing quote: %s"), *arg);
4640 	return FAIL;
4641     }
4642 
4643     /* If only parsing, set *arg and return here */
4644     if (!evaluate)
4645     {
4646 	*arg = p + 1;
4647 	return OK;
4648     }
4649 
4650     /*
4651      * Copy the string into allocated memory, handling backslashed
4652      * characters.
4653      */
4654     name = alloc((unsigned)(p - *arg + extra));
4655     if (name == NULL)
4656 	return FAIL;
4657     rettv->v_type = VAR_STRING;
4658     rettv->vval.v_string = name;
4659 
4660     for (p = *arg + 1; *p != NUL && *p != '"'; )
4661     {
4662 	if (*p == '\\')
4663 	{
4664 	    switch (*++p)
4665 	    {
4666 		case 'b': *name++ = BS; ++p; break;
4667 		case 'e': *name++ = ESC; ++p; break;
4668 		case 'f': *name++ = FF; ++p; break;
4669 		case 'n': *name++ = NL; ++p; break;
4670 		case 'r': *name++ = CAR; ++p; break;
4671 		case 't': *name++ = TAB; ++p; break;
4672 
4673 		case 'X': /* hex: "\x1", "\x12" */
4674 		case 'x':
4675 		case 'u': /* Unicode: "\u0023" */
4676 		case 'U':
4677 			  if (vim_isxdigit(p[1]))
4678 			  {
4679 			      int	n, nr;
4680 			      int	c = toupper(*p);
4681 
4682 			      if (c == 'X')
4683 				  n = 2;
4684 			      else if (*p == 'u')
4685 				  n = 4;
4686 			      else
4687 				  n = 8;
4688 			      nr = 0;
4689 			      while (--n >= 0 && vim_isxdigit(p[1]))
4690 			      {
4691 				  ++p;
4692 				  nr = (nr << 4) + hex2nr(*p);
4693 			      }
4694 			      ++p;
4695 #ifdef FEAT_MBYTE
4696 			      /* For "\u" store the number according to
4697 			       * 'encoding'. */
4698 			      if (c != 'X')
4699 				  name += (*mb_char2bytes)(nr, name);
4700 			      else
4701 #endif
4702 				  *name++ = nr;
4703 			  }
4704 			  break;
4705 
4706 			  /* octal: "\1", "\12", "\123" */
4707 		case '0':
4708 		case '1':
4709 		case '2':
4710 		case '3':
4711 		case '4':
4712 		case '5':
4713 		case '6':
4714 		case '7': *name = *p++ - '0';
4715 			  if (*p >= '0' && *p <= '7')
4716 			  {
4717 			      *name = (*name << 3) + *p++ - '0';
4718 			      if (*p >= '0' && *p <= '7')
4719 				  *name = (*name << 3) + *p++ - '0';
4720 			  }
4721 			  ++name;
4722 			  break;
4723 
4724 			    /* Special key, e.g.: "\<C-W>" */
4725 		case '<': extra = trans_special(&p, name, TRUE, TRUE);
4726 			  if (extra != 0)
4727 			  {
4728 			      name += extra;
4729 			      break;
4730 			  }
4731 			  /* FALLTHROUGH */
4732 
4733 		default:  MB_COPY_CHAR(p, name);
4734 			  break;
4735 	    }
4736 	}
4737 	else
4738 	    MB_COPY_CHAR(p, name);
4739 
4740     }
4741     *name = NUL;
4742     if (*p != NUL) /* just in case */
4743 	++p;
4744     *arg = p;
4745 
4746     return OK;
4747 }
4748 
4749 /*
4750  * Allocate a variable for a 'str''ing' constant.
4751  * Return OK or FAIL.
4752  */
4753     static int
4754 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
4755 {
4756     char_u	*p;
4757     char_u	*str;
4758     int		reduce = 0;
4759 
4760     /*
4761      * Find the end of the string, skipping ''.
4762      */
4763     for (p = *arg + 1; *p != NUL; MB_PTR_ADV(p))
4764     {
4765 	if (*p == '\'')
4766 	{
4767 	    if (p[1] != '\'')
4768 		break;
4769 	    ++reduce;
4770 	    ++p;
4771 	}
4772     }
4773 
4774     if (*p != '\'')
4775     {
4776 	EMSG2(_("E115: Missing quote: %s"), *arg);
4777 	return FAIL;
4778     }
4779 
4780     /* If only parsing return after setting "*arg" */
4781     if (!evaluate)
4782     {
4783 	*arg = p + 1;
4784 	return OK;
4785     }
4786 
4787     /*
4788      * Copy the string into allocated memory, handling '' to ' reduction.
4789      */
4790     str = alloc((unsigned)((p - *arg) - reduce));
4791     if (str == NULL)
4792 	return FAIL;
4793     rettv->v_type = VAR_STRING;
4794     rettv->vval.v_string = str;
4795 
4796     for (p = *arg + 1; *p != NUL; )
4797     {
4798 	if (*p == '\'')
4799 	{
4800 	    if (p[1] != '\'')
4801 		break;
4802 	    ++p;
4803 	}
4804 	MB_COPY_CHAR(p, str);
4805     }
4806     *str = NUL;
4807     *arg = p + 1;
4808 
4809     return OK;
4810 }
4811 
4812 /*
4813  * Return the function name of the partial.
4814  */
4815     char_u *
4816 partial_name(partial_T *pt)
4817 {
4818     if (pt->pt_name != NULL)
4819 	return pt->pt_name;
4820     return pt->pt_func->uf_name;
4821 }
4822 
4823     static void
4824 partial_free(partial_T *pt)
4825 {
4826     int i;
4827 
4828     for (i = 0; i < pt->pt_argc; ++i)
4829 	clear_tv(&pt->pt_argv[i]);
4830     vim_free(pt->pt_argv);
4831     dict_unref(pt->pt_dict);
4832     if (pt->pt_name != NULL)
4833     {
4834 	func_unref(pt->pt_name);
4835 	vim_free(pt->pt_name);
4836     }
4837     else
4838 	func_ptr_unref(pt->pt_func);
4839     vim_free(pt);
4840 }
4841 
4842 /*
4843  * Unreference a closure: decrement the reference count and free it when it
4844  * becomes zero.
4845  */
4846     void
4847 partial_unref(partial_T *pt)
4848 {
4849     if (pt != NULL && --pt->pt_refcount <= 0)
4850 	partial_free(pt);
4851 }
4852 
4853 static int tv_equal_recurse_limit;
4854 
4855     static int
4856 func_equal(
4857     typval_T *tv1,
4858     typval_T *tv2,
4859     int	     ic)	    /* ignore case */
4860 {
4861     char_u	*s1, *s2;
4862     dict_T	*d1, *d2;
4863     int		a1, a2;
4864     int		i;
4865 
4866     /* empty and NULL function name considered the same */
4867     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
4868 					   : partial_name(tv1->vval.v_partial);
4869     if (s1 != NULL && *s1 == NUL)
4870 	s1 = NULL;
4871     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
4872 					   : partial_name(tv2->vval.v_partial);
4873     if (s2 != NULL && *s2 == NUL)
4874 	s2 = NULL;
4875     if (s1 == NULL || s2 == NULL)
4876     {
4877 	if (s1 != s2)
4878 	    return FALSE;
4879     }
4880     else if (STRCMP(s1, s2) != 0)
4881 	return FALSE;
4882 
4883     /* empty dict and NULL dict is different */
4884     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
4885     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
4886     if (d1 == NULL || d2 == NULL)
4887     {
4888 	if (d1 != d2)
4889 	    return FALSE;
4890     }
4891     else if (!dict_equal(d1, d2, ic, TRUE))
4892 	return FALSE;
4893 
4894     /* empty list and no list considered the same */
4895     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
4896     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
4897     if (a1 != a2)
4898 	return FALSE;
4899     for (i = 0; i < a1; ++i)
4900 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
4901 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
4902 	    return FALSE;
4903 
4904     return TRUE;
4905 }
4906 
4907 /*
4908  * Return TRUE if "tv1" and "tv2" have the same value.
4909  * Compares the items just like "==" would compare them, but strings and
4910  * numbers are different.  Floats and numbers are also different.
4911  */
4912     int
4913 tv_equal(
4914     typval_T *tv1,
4915     typval_T *tv2,
4916     int	     ic,	    /* ignore case */
4917     int	     recursive)	    /* TRUE when used recursively */
4918 {
4919     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
4920     char_u	*s1, *s2;
4921     static int  recursive_cnt = 0;	    /* catch recursive loops */
4922     int		r;
4923 
4924     /* Catch lists and dicts that have an endless loop by limiting
4925      * recursiveness to a limit.  We guess they are equal then.
4926      * A fixed limit has the problem of still taking an awful long time.
4927      * Reduce the limit every time running into it. That should work fine for
4928      * deeply linked structures that are not recursively linked and catch
4929      * recursiveness quickly. */
4930     if (!recursive)
4931 	tv_equal_recurse_limit = 1000;
4932     if (recursive_cnt >= tv_equal_recurse_limit)
4933     {
4934 	--tv_equal_recurse_limit;
4935 	return TRUE;
4936     }
4937 
4938     /* For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
4939      * arguments. */
4940     if ((tv1->v_type == VAR_FUNC
4941 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
4942 	    && (tv2->v_type == VAR_FUNC
4943 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
4944     {
4945 	++recursive_cnt;
4946 	r = func_equal(tv1, tv2, ic);
4947 	--recursive_cnt;
4948 	return r;
4949     }
4950 
4951     if (tv1->v_type != tv2->v_type)
4952 	return FALSE;
4953 
4954     switch (tv1->v_type)
4955     {
4956 	case VAR_LIST:
4957 	    ++recursive_cnt;
4958 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
4959 	    --recursive_cnt;
4960 	    return r;
4961 
4962 	case VAR_DICT:
4963 	    ++recursive_cnt;
4964 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
4965 	    --recursive_cnt;
4966 	    return r;
4967 
4968 	case VAR_NUMBER:
4969 	    return tv1->vval.v_number == tv2->vval.v_number;
4970 
4971 	case VAR_STRING:
4972 	    s1 = get_tv_string_buf(tv1, buf1);
4973 	    s2 = get_tv_string_buf(tv2, buf2);
4974 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
4975 
4976 	case VAR_SPECIAL:
4977 	    return tv1->vval.v_number == tv2->vval.v_number;
4978 
4979 	case VAR_FLOAT:
4980 #ifdef FEAT_FLOAT
4981 	    return tv1->vval.v_float == tv2->vval.v_float;
4982 #endif
4983 	case VAR_JOB:
4984 #ifdef FEAT_JOB_CHANNEL
4985 	    return tv1->vval.v_job == tv2->vval.v_job;
4986 #endif
4987 	case VAR_CHANNEL:
4988 #ifdef FEAT_JOB_CHANNEL
4989 	    return tv1->vval.v_channel == tv2->vval.v_channel;
4990 #endif
4991 	case VAR_FUNC:
4992 	case VAR_PARTIAL:
4993 	case VAR_UNKNOWN:
4994 	    break;
4995     }
4996 
4997     /* VAR_UNKNOWN can be the result of a invalid expression, let's say it
4998      * does not equal anything, not even itself. */
4999     return FALSE;
5000 }
5001 
5002 /*
5003  * Return the next (unique) copy ID.
5004  * Used for serializing nested structures.
5005  */
5006     int
5007 get_copyID(void)
5008 {
5009     current_copyID += COPYID_INC;
5010     return current_copyID;
5011 }
5012 
5013 /*
5014  * Garbage collection for lists and dictionaries.
5015  *
5016  * We use reference counts to be able to free most items right away when they
5017  * are no longer used.  But for composite items it's possible that it becomes
5018  * unused while the reference count is > 0: When there is a recursive
5019  * reference.  Example:
5020  *	:let l = [1, 2, 3]
5021  *	:let d = {9: l}
5022  *	:let l[1] = d
5023  *
5024  * Since this is quite unusual we handle this with garbage collection: every
5025  * once in a while find out which lists and dicts are not referenced from any
5026  * variable.
5027  *
5028  * Here is a good reference text about garbage collection (refers to Python
5029  * but it applies to all reference-counting mechanisms):
5030  *	http://python.ca/nas/python/gc/
5031  */
5032 
5033 /*
5034  * Do garbage collection for lists and dicts.
5035  * When "testing" is TRUE this is called from test_garbagecollect_now().
5036  * Return TRUE if some memory was freed.
5037  */
5038     int
5039 garbage_collect(int testing)
5040 {
5041     int		copyID;
5042     int		abort = FALSE;
5043     buf_T	*buf;
5044     win_T	*wp;
5045     int		i;
5046     int		did_free = FALSE;
5047     tabpage_T	*tp;
5048 
5049     if (!testing)
5050     {
5051 	/* Only do this once. */
5052 	want_garbage_collect = FALSE;
5053 	may_garbage_collect = FALSE;
5054 	garbage_collect_at_exit = FALSE;
5055     }
5056 
5057     /* We advance by two because we add one for items referenced through
5058      * previous_funccal. */
5059     copyID = get_copyID();
5060 
5061     /*
5062      * 1. Go through all accessible variables and mark all lists and dicts
5063      *    with copyID.
5064      */
5065 
5066     /* Don't free variables in the previous_funccal list unless they are only
5067      * referenced through previous_funccal.  This must be first, because if
5068      * the item is referenced elsewhere the funccal must not be freed. */
5069     abort = abort || set_ref_in_previous_funccal(copyID);
5070 
5071     /* script-local variables */
5072     for (i = 1; i <= ga_scripts.ga_len; ++i)
5073 	abort = abort || set_ref_in_ht(&SCRIPT_VARS(i), copyID, NULL);
5074 
5075     /* buffer-local variables */
5076     FOR_ALL_BUFFERS(buf)
5077 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
5078 								  NULL, NULL);
5079 
5080     /* window-local variables */
5081     FOR_ALL_TAB_WINDOWS(tp, wp)
5082 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
5083 								  NULL, NULL);
5084     if (aucmd_win != NULL)
5085 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
5086 								  NULL, NULL);
5087 
5088     /* tabpage-local variables */
5089     FOR_ALL_TABPAGES(tp)
5090 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
5091 								  NULL, NULL);
5092     /* global variables */
5093     abort = abort || set_ref_in_ht(&globvarht, copyID, NULL);
5094 
5095     /* function-local variables */
5096     abort = abort || set_ref_in_call_stack(copyID);
5097 
5098     /* named functions (matters for closures) */
5099     abort = abort || set_ref_in_functions(copyID);
5100 
5101     /* function call arguments, if v:testing is set. */
5102     abort = abort || set_ref_in_func_args(copyID);
5103 
5104     /* v: vars */
5105     abort = abort || set_ref_in_ht(&vimvarht, copyID, NULL);
5106 
5107 #ifdef FEAT_LUA
5108     abort = abort || set_ref_in_lua(copyID);
5109 #endif
5110 
5111 #ifdef FEAT_PYTHON
5112     abort = abort || set_ref_in_python(copyID);
5113 #endif
5114 
5115 #ifdef FEAT_PYTHON3
5116     abort = abort || set_ref_in_python3(copyID);
5117 #endif
5118 
5119 #ifdef FEAT_JOB_CHANNEL
5120     abort = abort || set_ref_in_channel(copyID);
5121     abort = abort || set_ref_in_job(copyID);
5122 #endif
5123 #ifdef FEAT_NETBEANS_INTG
5124     abort = abort || set_ref_in_nb_channel(copyID);
5125 #endif
5126 
5127 #ifdef FEAT_TIMERS
5128     abort = abort || set_ref_in_timer(copyID);
5129 #endif
5130 
5131 #ifdef FEAT_QUICKFIX
5132     abort = abort || set_ref_in_quickfix(copyID);
5133 #endif
5134 
5135 #ifdef FEAT_TERMINAL
5136     abort = abort || set_ref_in_term(copyID);
5137 #endif
5138 
5139     if (!abort)
5140     {
5141 	/*
5142 	 * 2. Free lists and dictionaries that are not referenced.
5143 	 */
5144 	did_free = free_unref_items(copyID);
5145 
5146 	/*
5147 	 * 3. Check if any funccal can be freed now.
5148 	 *    This may call us back recursively.
5149 	 */
5150 	free_unref_funccal(copyID, testing);
5151     }
5152     else if (p_verbose > 0)
5153     {
5154 	verb_msg((char_u *)_("Not enough memory to set references, garbage collection aborted!"));
5155     }
5156 
5157     return did_free;
5158 }
5159 
5160 /*
5161  * Free lists, dictionaries, channels and jobs that are no longer referenced.
5162  */
5163     static int
5164 free_unref_items(int copyID)
5165 {
5166     int		did_free = FALSE;
5167 
5168     /* Let all "free" functions know that we are here.  This means no
5169      * dictionaries, lists, channels or jobs are to be freed, because we will
5170      * do that here. */
5171     in_free_unref_items = TRUE;
5172 
5173     /*
5174      * PASS 1: free the contents of the items.  We don't free the items
5175      * themselves yet, so that it is possible to decrement refcount counters
5176      */
5177 
5178     /* Go through the list of dicts and free items without the copyID. */
5179     did_free |= dict_free_nonref(copyID);
5180 
5181     /* Go through the list of lists and free items without the copyID. */
5182     did_free |= list_free_nonref(copyID);
5183 
5184 #ifdef FEAT_JOB_CHANNEL
5185     /* Go through the list of jobs and free items without the copyID. This
5186      * must happen before doing channels, because jobs refer to channels, but
5187      * the reference from the channel to the job isn't tracked. */
5188     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
5189 
5190     /* Go through the list of channels and free items without the copyID.  */
5191     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
5192 #endif
5193 
5194     /*
5195      * PASS 2: free the items themselves.
5196      */
5197     dict_free_items(copyID);
5198     list_free_items(copyID);
5199 
5200 #ifdef FEAT_JOB_CHANNEL
5201     /* Go through the list of jobs and free items without the copyID. This
5202      * must happen before doing channels, because jobs refer to channels, but
5203      * the reference from the channel to the job isn't tracked. */
5204     free_unused_jobs(copyID, COPYID_MASK);
5205 
5206     /* Go through the list of channels and free items without the copyID.  */
5207     free_unused_channels(copyID, COPYID_MASK);
5208 #endif
5209 
5210     in_free_unref_items = FALSE;
5211 
5212     return did_free;
5213 }
5214 
5215 /*
5216  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
5217  * "list_stack" is used to add lists to be marked.  Can be NULL.
5218  *
5219  * Returns TRUE if setting references failed somehow.
5220  */
5221     int
5222 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
5223 {
5224     int		todo;
5225     int		abort = FALSE;
5226     hashitem_T	*hi;
5227     hashtab_T	*cur_ht;
5228     ht_stack_T	*ht_stack = NULL;
5229     ht_stack_T	*tempitem;
5230 
5231     cur_ht = ht;
5232     for (;;)
5233     {
5234 	if (!abort)
5235 	{
5236 	    /* Mark each item in the hashtab.  If the item contains a hashtab
5237 	     * it is added to ht_stack, if it contains a list it is added to
5238 	     * list_stack. */
5239 	    todo = (int)cur_ht->ht_used;
5240 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
5241 		if (!HASHITEM_EMPTY(hi))
5242 		{
5243 		    --todo;
5244 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
5245 						       &ht_stack, list_stack);
5246 		}
5247 	}
5248 
5249 	if (ht_stack == NULL)
5250 	    break;
5251 
5252 	/* take an item from the stack */
5253 	cur_ht = ht_stack->ht;
5254 	tempitem = ht_stack;
5255 	ht_stack = ht_stack->prev;
5256 	free(tempitem);
5257     }
5258 
5259     return abort;
5260 }
5261 
5262 /*
5263  * Mark all lists and dicts referenced through list "l" with "copyID".
5264  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5265  *
5266  * Returns TRUE if setting references failed somehow.
5267  */
5268     int
5269 set_ref_in_list(list_T *l, int copyID, ht_stack_T **ht_stack)
5270 {
5271     listitem_T	 *li;
5272     int		 abort = FALSE;
5273     list_T	 *cur_l;
5274     list_stack_T *list_stack = NULL;
5275     list_stack_T *tempitem;
5276 
5277     cur_l = l;
5278     for (;;)
5279     {
5280 	if (!abort)
5281 	    /* Mark each item in the list.  If the item contains a hashtab
5282 	     * it is added to ht_stack, if it contains a list it is added to
5283 	     * list_stack. */
5284 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
5285 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
5286 						       ht_stack, &list_stack);
5287 	if (list_stack == NULL)
5288 	    break;
5289 
5290 	/* take an item from the stack */
5291 	cur_l = list_stack->list;
5292 	tempitem = list_stack;
5293 	list_stack = list_stack->prev;
5294 	free(tempitem);
5295     }
5296 
5297     return abort;
5298 }
5299 
5300 /*
5301  * Mark all lists and dicts referenced through typval "tv" with "copyID".
5302  * "list_stack" is used to add lists to be marked.  Can be NULL.
5303  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5304  *
5305  * Returns TRUE if setting references failed somehow.
5306  */
5307     int
5308 set_ref_in_item(
5309     typval_T	    *tv,
5310     int		    copyID,
5311     ht_stack_T	    **ht_stack,
5312     list_stack_T    **list_stack)
5313 {
5314     int		abort = FALSE;
5315 
5316     if (tv->v_type == VAR_DICT)
5317     {
5318 	dict_T	*dd = tv->vval.v_dict;
5319 
5320 	if (dd != NULL && dd->dv_copyID != copyID)
5321 	{
5322 	    /* Didn't see this dict yet. */
5323 	    dd->dv_copyID = copyID;
5324 	    if (ht_stack == NULL)
5325 	    {
5326 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
5327 	    }
5328 	    else
5329 	    {
5330 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
5331 		if (newitem == NULL)
5332 		    abort = TRUE;
5333 		else
5334 		{
5335 		    newitem->ht = &dd->dv_hashtab;
5336 		    newitem->prev = *ht_stack;
5337 		    *ht_stack = newitem;
5338 		}
5339 	    }
5340 	}
5341     }
5342     else if (tv->v_type == VAR_LIST)
5343     {
5344 	list_T	*ll = tv->vval.v_list;
5345 
5346 	if (ll != NULL && ll->lv_copyID != copyID)
5347 	{
5348 	    /* Didn't see this list yet. */
5349 	    ll->lv_copyID = copyID;
5350 	    if (list_stack == NULL)
5351 	    {
5352 		abort = set_ref_in_list(ll, copyID, ht_stack);
5353 	    }
5354 	    else
5355 	    {
5356 		list_stack_T *newitem = (list_stack_T*)malloc(
5357 							sizeof(list_stack_T));
5358 		if (newitem == NULL)
5359 		    abort = TRUE;
5360 		else
5361 		{
5362 		    newitem->list = ll;
5363 		    newitem->prev = *list_stack;
5364 		    *list_stack = newitem;
5365 		}
5366 	    }
5367 	}
5368     }
5369     else if (tv->v_type == VAR_FUNC)
5370     {
5371 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
5372     }
5373     else if (tv->v_type == VAR_PARTIAL)
5374     {
5375 	partial_T	*pt = tv->vval.v_partial;
5376 	int		i;
5377 
5378 	/* A partial does not have a copyID, because it cannot contain itself.
5379 	 */
5380 	if (pt != NULL)
5381 	{
5382 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
5383 
5384 	    if (pt->pt_dict != NULL)
5385 	    {
5386 		typval_T dtv;
5387 
5388 		dtv.v_type = VAR_DICT;
5389 		dtv.vval.v_dict = pt->pt_dict;
5390 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5391 	    }
5392 
5393 	    for (i = 0; i < pt->pt_argc; ++i)
5394 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
5395 							ht_stack, list_stack);
5396 	}
5397     }
5398 #ifdef FEAT_JOB_CHANNEL
5399     else if (tv->v_type == VAR_JOB)
5400     {
5401 	job_T	    *job = tv->vval.v_job;
5402 	typval_T    dtv;
5403 
5404 	if (job != NULL && job->jv_copyID != copyID)
5405 	{
5406 	    job->jv_copyID = copyID;
5407 	    if (job->jv_channel != NULL)
5408 	    {
5409 		dtv.v_type = VAR_CHANNEL;
5410 		dtv.vval.v_channel = job->jv_channel;
5411 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5412 	    }
5413 	    if (job->jv_exit_partial != NULL)
5414 	    {
5415 		dtv.v_type = VAR_PARTIAL;
5416 		dtv.vval.v_partial = job->jv_exit_partial;
5417 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5418 	    }
5419 	}
5420     }
5421     else if (tv->v_type == VAR_CHANNEL)
5422     {
5423 	channel_T   *ch =tv->vval.v_channel;
5424 	ch_part_T   part;
5425 	typval_T    dtv;
5426 	jsonq_T	    *jq;
5427 	cbq_T	    *cq;
5428 
5429 	if (ch != NULL && ch->ch_copyID != copyID)
5430 	{
5431 	    ch->ch_copyID = copyID;
5432 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
5433 	    {
5434 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
5435 							     jq = jq->jq_next)
5436 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
5437 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
5438 							     cq = cq->cq_next)
5439 		    if (cq->cq_partial != NULL)
5440 		    {
5441 			dtv.v_type = VAR_PARTIAL;
5442 			dtv.vval.v_partial = cq->cq_partial;
5443 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5444 		    }
5445 		if (ch->ch_part[part].ch_partial != NULL)
5446 		{
5447 		    dtv.v_type = VAR_PARTIAL;
5448 		    dtv.vval.v_partial = ch->ch_part[part].ch_partial;
5449 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5450 		}
5451 	    }
5452 	    if (ch->ch_partial != NULL)
5453 	    {
5454 		dtv.v_type = VAR_PARTIAL;
5455 		dtv.vval.v_partial = ch->ch_partial;
5456 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5457 	    }
5458 	    if (ch->ch_close_partial != NULL)
5459 	    {
5460 		dtv.v_type = VAR_PARTIAL;
5461 		dtv.vval.v_partial = ch->ch_close_partial;
5462 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5463 	    }
5464 	}
5465     }
5466 #endif
5467     return abort;
5468 }
5469 
5470     static char *
5471 get_var_special_name(int nr)
5472 {
5473     switch (nr)
5474     {
5475 	case VVAL_FALSE: return "v:false";
5476 	case VVAL_TRUE:  return "v:true";
5477 	case VVAL_NONE:  return "v:none";
5478 	case VVAL_NULL:  return "v:null";
5479     }
5480     internal_error("get_var_special_name()");
5481     return "42";
5482 }
5483 
5484 /*
5485  * Return a string with the string representation of a variable.
5486  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5487  * "numbuf" is used for a number.
5488  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5489  * When both "echo_style" and "composite_val" are FALSE, put quotes around
5490  * stings as "string()", otherwise does not put quotes around strings, as
5491  * ":echo" displays values.
5492  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
5493  * are replaced with "...".
5494  * May return NULL.
5495  */
5496     char_u *
5497 echo_string_core(
5498     typval_T	*tv,
5499     char_u	**tofree,
5500     char_u	*numbuf,
5501     int		copyID,
5502     int		echo_style,
5503     int		restore_copyID,
5504     int		composite_val)
5505 {
5506     static int	recurse = 0;
5507     char_u	*r = NULL;
5508 
5509     if (recurse >= DICT_MAXNEST)
5510     {
5511 	if (!did_echo_string_emsg)
5512 	{
5513 	    /* Only give this message once for a recursive call to avoid
5514 	     * flooding the user with errors.  And stop iterating over lists
5515 	     * and dicts. */
5516 	    did_echo_string_emsg = TRUE;
5517 	    EMSG(_("E724: variable nested too deep for displaying"));
5518 	}
5519 	*tofree = NULL;
5520 	return (char_u *)"{E724}";
5521     }
5522     ++recurse;
5523 
5524     switch (tv->v_type)
5525     {
5526 	case VAR_STRING:
5527 	    if (echo_style && !composite_val)
5528 	    {
5529 		*tofree = NULL;
5530 		r = tv->vval.v_string;
5531 		if (r == NULL)
5532 		    r = (char_u *)"";
5533 	    }
5534 	    else
5535 	    {
5536 		*tofree = string_quote(tv->vval.v_string, FALSE);
5537 		r = *tofree;
5538 	    }
5539 	    break;
5540 
5541 	case VAR_FUNC:
5542 	    if (echo_style)
5543 	    {
5544 		*tofree = NULL;
5545 		r = tv->vval.v_string;
5546 	    }
5547 	    else
5548 	    {
5549 		*tofree = string_quote(tv->vval.v_string, TRUE);
5550 		r = *tofree;
5551 	    }
5552 	    break;
5553 
5554 	case VAR_PARTIAL:
5555 	    {
5556 		partial_T   *pt = tv->vval.v_partial;
5557 		char_u	    *fname = string_quote(pt == NULL ? NULL
5558 						    : partial_name(pt), FALSE);
5559 		garray_T    ga;
5560 		int	    i;
5561 		char_u	    *tf;
5562 
5563 		ga_init2(&ga, 1, 100);
5564 		ga_concat(&ga, (char_u *)"function(");
5565 		if (fname != NULL)
5566 		{
5567 		    ga_concat(&ga, fname);
5568 		    vim_free(fname);
5569 		}
5570 		if (pt != NULL && pt->pt_argc > 0)
5571 		{
5572 		    ga_concat(&ga, (char_u *)", [");
5573 		    for (i = 0; i < pt->pt_argc; ++i)
5574 		    {
5575 			if (i > 0)
5576 			    ga_concat(&ga, (char_u *)", ");
5577 			ga_concat(&ga,
5578 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
5579 			vim_free(tf);
5580 		    }
5581 		    ga_concat(&ga, (char_u *)"]");
5582 		}
5583 		if (pt != NULL && pt->pt_dict != NULL)
5584 		{
5585 		    typval_T dtv;
5586 
5587 		    ga_concat(&ga, (char_u *)", ");
5588 		    dtv.v_type = VAR_DICT;
5589 		    dtv.vval.v_dict = pt->pt_dict;
5590 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
5591 		    vim_free(tf);
5592 		}
5593 		ga_concat(&ga, (char_u *)")");
5594 
5595 		*tofree = ga.ga_data;
5596 		r = *tofree;
5597 		break;
5598 	    }
5599 
5600 	case VAR_LIST:
5601 	    if (tv->vval.v_list == NULL)
5602 	    {
5603 		*tofree = NULL;
5604 		r = NULL;
5605 	    }
5606 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
5607 		    && tv->vval.v_list->lv_len > 0)
5608 	    {
5609 		*tofree = NULL;
5610 		r = (char_u *)"[...]";
5611 	    }
5612 	    else
5613 	    {
5614 		int old_copyID = tv->vval.v_list->lv_copyID;
5615 
5616 		tv->vval.v_list->lv_copyID = copyID;
5617 		*tofree = list2string(tv, copyID, restore_copyID);
5618 		if (restore_copyID)
5619 		    tv->vval.v_list->lv_copyID = old_copyID;
5620 		r = *tofree;
5621 	    }
5622 	    break;
5623 
5624 	case VAR_DICT:
5625 	    if (tv->vval.v_dict == NULL)
5626 	    {
5627 		*tofree = NULL;
5628 		r = NULL;
5629 	    }
5630 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
5631 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
5632 	    {
5633 		*tofree = NULL;
5634 		r = (char_u *)"{...}";
5635 	    }
5636 	    else
5637 	    {
5638 		int old_copyID = tv->vval.v_dict->dv_copyID;
5639 		tv->vval.v_dict->dv_copyID = copyID;
5640 		*tofree = dict2string(tv, copyID, restore_copyID);
5641 		if (restore_copyID)
5642 		    tv->vval.v_dict->dv_copyID = old_copyID;
5643 		r = *tofree;
5644 	    }
5645 	    break;
5646 
5647 	case VAR_NUMBER:
5648 	case VAR_UNKNOWN:
5649 	    *tofree = NULL;
5650 	    r = get_tv_string_buf(tv, numbuf);
5651 	    break;
5652 
5653 	case VAR_JOB:
5654 	case VAR_CHANNEL:
5655 	    *tofree = NULL;
5656 	    r = get_tv_string_buf(tv, numbuf);
5657 	    if (composite_val)
5658 	    {
5659 		*tofree = string_quote(r, FALSE);
5660 		r = *tofree;
5661 	    }
5662 	    break;
5663 
5664 	case VAR_FLOAT:
5665 #ifdef FEAT_FLOAT
5666 	    *tofree = NULL;
5667 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
5668 	    r = numbuf;
5669 	    break;
5670 #endif
5671 
5672 	case VAR_SPECIAL:
5673 	    *tofree = NULL;
5674 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
5675 	    break;
5676     }
5677 
5678     if (--recurse == 0)
5679 	did_echo_string_emsg = FALSE;
5680     return r;
5681 }
5682 
5683 /*
5684  * Return a string with the string representation of a variable.
5685  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5686  * "numbuf" is used for a number.
5687  * Does not put quotes around strings, as ":echo" displays values.
5688  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5689  * May return NULL.
5690  */
5691     char_u *
5692 echo_string(
5693     typval_T	*tv,
5694     char_u	**tofree,
5695     char_u	*numbuf,
5696     int		copyID)
5697 {
5698     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
5699 }
5700 
5701 /*
5702  * Return a string with the string representation of a variable.
5703  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5704  * "numbuf" is used for a number.
5705  * Puts quotes around strings, so that they can be parsed back by eval().
5706  * May return NULL.
5707  */
5708     char_u *
5709 tv2string(
5710     typval_T	*tv,
5711     char_u	**tofree,
5712     char_u	*numbuf,
5713     int		copyID)
5714 {
5715     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
5716 }
5717 
5718 /*
5719  * Return string "str" in ' quotes, doubling ' characters.
5720  * If "str" is NULL an empty string is assumed.
5721  * If "function" is TRUE make it function('string').
5722  */
5723     char_u *
5724 string_quote(char_u *str, int function)
5725 {
5726     unsigned	len;
5727     char_u	*p, *r, *s;
5728 
5729     len = (function ? 13 : 3);
5730     if (str != NULL)
5731     {
5732 	len += (unsigned)STRLEN(str);
5733 	for (p = str; *p != NUL; MB_PTR_ADV(p))
5734 	    if (*p == '\'')
5735 		++len;
5736     }
5737     s = r = alloc(len);
5738     if (r != NULL)
5739     {
5740 	if (function)
5741 	{
5742 	    STRCPY(r, "function('");
5743 	    r += 10;
5744 	}
5745 	else
5746 	    *r++ = '\'';
5747 	if (str != NULL)
5748 	    for (p = str; *p != NUL; )
5749 	    {
5750 		if (*p == '\'')
5751 		    *r++ = '\'';
5752 		MB_COPY_CHAR(p, r);
5753 	    }
5754 	*r++ = '\'';
5755 	if (function)
5756 	    *r++ = ')';
5757 	*r++ = NUL;
5758     }
5759     return s;
5760 }
5761 
5762 #if defined(FEAT_FLOAT) || defined(PROTO)
5763 /*
5764  * Convert the string "text" to a floating point number.
5765  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
5766  * this always uses a decimal point.
5767  * Returns the length of the text that was consumed.
5768  */
5769     int
5770 string2float(
5771     char_u	*text,
5772     float_T	*value)	    /* result stored here */
5773 {
5774     char	*s = (char *)text;
5775     float_T	f;
5776 
5777     /* MS-Windows does not deal with "inf" and "nan" properly. */
5778     if (STRNICMP(text, "inf", 3) == 0)
5779     {
5780 	*value = INFINITY;
5781 	return 3;
5782     }
5783     if (STRNICMP(text, "-inf", 3) == 0)
5784     {
5785 	*value = -INFINITY;
5786 	return 4;
5787     }
5788     if (STRNICMP(text, "nan", 3) == 0)
5789     {
5790 	*value = NAN;
5791 	return 3;
5792     }
5793     f = strtod(s, &s);
5794     *value = f;
5795     return (int)((char_u *)s - text);
5796 }
5797 #endif
5798 
5799 /*
5800  * Get the value of an environment variable.
5801  * "arg" is pointing to the '$'.  It is advanced to after the name.
5802  * If the environment variable was not set, silently assume it is empty.
5803  * Return FAIL if the name is invalid.
5804  */
5805     static int
5806 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
5807 {
5808     char_u	*string = NULL;
5809     int		len;
5810     int		cc;
5811     char_u	*name;
5812     int		mustfree = FALSE;
5813 
5814     ++*arg;
5815     name = *arg;
5816     len = get_env_len(arg);
5817     if (evaluate)
5818     {
5819 	if (len == 0)
5820 	    return FAIL; /* invalid empty name */
5821 
5822 	cc = name[len];
5823 	name[len] = NUL;
5824 	/* first try vim_getenv(), fast for normal environment vars */
5825 	string = vim_getenv(name, &mustfree);
5826 	if (string != NULL && *string != NUL)
5827 	{
5828 	    if (!mustfree)
5829 		string = vim_strsave(string);
5830 	}
5831 	else
5832 	{
5833 	    if (mustfree)
5834 		vim_free(string);
5835 
5836 	    /* next try expanding things like $VIM and ${HOME} */
5837 	    string = expand_env_save(name - 1);
5838 	    if (string != NULL && *string == '$')
5839 		VIM_CLEAR(string);
5840 	}
5841 	name[len] = cc;
5842 
5843 	rettv->v_type = VAR_STRING;
5844 	rettv->vval.v_string = string;
5845     }
5846 
5847     return OK;
5848 }
5849 
5850 
5851 
5852 /*
5853  * Translate a String variable into a position.
5854  * Returns NULL when there is an error.
5855  */
5856     pos_T *
5857 var2fpos(
5858     typval_T	*varp,
5859     int		dollar_lnum,	/* TRUE when $ is last line */
5860     int		*fnum)		/* set to fnum for '0, 'A, etc. */
5861 {
5862     char_u		*name;
5863     static pos_T	pos;
5864     pos_T		*pp;
5865 
5866     /* Argument can be [lnum, col, coladd]. */
5867     if (varp->v_type == VAR_LIST)
5868     {
5869 	list_T		*l;
5870 	int		len;
5871 	int		error = FALSE;
5872 	listitem_T	*li;
5873 
5874 	l = varp->vval.v_list;
5875 	if (l == NULL)
5876 	    return NULL;
5877 
5878 	/* Get the line number */
5879 	pos.lnum = list_find_nr(l, 0L, &error);
5880 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
5881 	    return NULL;	/* invalid line number */
5882 
5883 	/* Get the column number */
5884 	pos.col = list_find_nr(l, 1L, &error);
5885 	if (error)
5886 	    return NULL;
5887 	len = (long)STRLEN(ml_get(pos.lnum));
5888 
5889 	/* We accept "$" for the column number: last column. */
5890 	li = list_find(l, 1L);
5891 	if (li != NULL && li->li_tv.v_type == VAR_STRING
5892 		&& li->li_tv.vval.v_string != NULL
5893 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
5894 	    pos.col = len + 1;
5895 
5896 	/* Accept a position up to the NUL after the line. */
5897 	if (pos.col == 0 || (int)pos.col > len + 1)
5898 	    return NULL;	/* invalid column number */
5899 	--pos.col;
5900 
5901 #ifdef FEAT_VIRTUALEDIT
5902 	/* Get the virtual offset.  Defaults to zero. */
5903 	pos.coladd = list_find_nr(l, 2L, &error);
5904 	if (error)
5905 	    pos.coladd = 0;
5906 #endif
5907 
5908 	return &pos;
5909     }
5910 
5911     name = get_tv_string_chk(varp);
5912     if (name == NULL)
5913 	return NULL;
5914     if (name[0] == '.')				/* cursor */
5915 	return &curwin->w_cursor;
5916     if (name[0] == 'v' && name[1] == NUL)	/* Visual start */
5917     {
5918 	if (VIsual_active)
5919 	    return &VIsual;
5920 	return &curwin->w_cursor;
5921     }
5922     if (name[0] == '\'')			/* mark */
5923     {
5924 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
5925 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
5926 	    return NULL;
5927 	return pp;
5928     }
5929 
5930 #ifdef FEAT_VIRTUALEDIT
5931     pos.coladd = 0;
5932 #endif
5933 
5934     if (name[0] == 'w' && dollar_lnum)
5935     {
5936 	pos.col = 0;
5937 	if (name[1] == '0')		/* "w0": first visible line */
5938 	{
5939 	    update_topline();
5940 	    /* In silent Ex mode topline is zero, but that's not a valid line
5941 	     * number; use one instead. */
5942 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
5943 	    return &pos;
5944 	}
5945 	else if (name[1] == '$')	/* "w$": last visible line */
5946 	{
5947 	    validate_botline();
5948 	    /* In silent Ex mode botline is zero, return zero then. */
5949 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
5950 	    return &pos;
5951 	}
5952     }
5953     else if (name[0] == '$')		/* last column or line */
5954     {
5955 	if (dollar_lnum)
5956 	{
5957 	    pos.lnum = curbuf->b_ml.ml_line_count;
5958 	    pos.col = 0;
5959 	}
5960 	else
5961 	{
5962 	    pos.lnum = curwin->w_cursor.lnum;
5963 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
5964 	}
5965 	return &pos;
5966     }
5967     return NULL;
5968 }
5969 
5970 /*
5971  * Convert list in "arg" into a position and optional file number.
5972  * When "fnump" is NULL there is no file number, only 3 items.
5973  * Note that the column is passed on as-is, the caller may want to decrement
5974  * it to use 1 for the first column.
5975  * Return FAIL when conversion is not possible, doesn't check the position for
5976  * validity.
5977  */
5978     int
5979 list2fpos(
5980     typval_T	*arg,
5981     pos_T	*posp,
5982     int		*fnump,
5983     colnr_T	*curswantp)
5984 {
5985     list_T	*l = arg->vval.v_list;
5986     long	i = 0;
5987     long	n;
5988 
5989     /* List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
5990      * there when "fnump" isn't NULL; "coladd" and "curswant" are optional. */
5991     if (arg->v_type != VAR_LIST
5992 	    || l == NULL
5993 	    || l->lv_len < (fnump == NULL ? 2 : 3)
5994 	    || l->lv_len > (fnump == NULL ? 4 : 5))
5995 	return FAIL;
5996 
5997     if (fnump != NULL)
5998     {
5999 	n = list_find_nr(l, i++, NULL);	/* fnum */
6000 	if (n < 0)
6001 	    return FAIL;
6002 	if (n == 0)
6003 	    n = curbuf->b_fnum;		/* current buffer */
6004 	*fnump = n;
6005     }
6006 
6007     n = list_find_nr(l, i++, NULL);	/* lnum */
6008     if (n < 0)
6009 	return FAIL;
6010     posp->lnum = n;
6011 
6012     n = list_find_nr(l, i++, NULL);	/* col */
6013     if (n < 0)
6014 	return FAIL;
6015     posp->col = n;
6016 
6017 #ifdef FEAT_VIRTUALEDIT
6018     n = list_find_nr(l, i, NULL);	/* off */
6019     if (n < 0)
6020 	posp->coladd = 0;
6021     else
6022 	posp->coladd = n;
6023 #endif
6024 
6025     if (curswantp != NULL)
6026 	*curswantp = list_find_nr(l, i + 1, NULL);  /* curswant */
6027 
6028     return OK;
6029 }
6030 
6031 /*
6032  * Get the length of an environment variable name.
6033  * Advance "arg" to the first character after the name.
6034  * Return 0 for error.
6035  */
6036     static int
6037 get_env_len(char_u **arg)
6038 {
6039     char_u	*p;
6040     int		len;
6041 
6042     for (p = *arg; vim_isIDc(*p); ++p)
6043 	;
6044     if (p == *arg)	    /* no name found */
6045 	return 0;
6046 
6047     len = (int)(p - *arg);
6048     *arg = p;
6049     return len;
6050 }
6051 
6052 /*
6053  * Get the length of the name of a function or internal variable.
6054  * "arg" is advanced to the first non-white character after the name.
6055  * Return 0 if something is wrong.
6056  */
6057     int
6058 get_id_len(char_u **arg)
6059 {
6060     char_u	*p;
6061     int		len;
6062 
6063     /* Find the end of the name. */
6064     for (p = *arg; eval_isnamec(*p); ++p)
6065     {
6066 	if (*p == ':')
6067 	{
6068 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6069 	     * slice "[n:]".  Also "xx:" is not a namespace. */
6070 	    len = (int)(p - *arg);
6071 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
6072 		    || len > 1)
6073 		break;
6074 	}
6075     }
6076     if (p == *arg)	    /* no name found */
6077 	return 0;
6078 
6079     len = (int)(p - *arg);
6080     *arg = skipwhite(p);
6081 
6082     return len;
6083 }
6084 
6085 /*
6086  * Get the length of the name of a variable or function.
6087  * Only the name is recognized, does not handle ".key" or "[idx]".
6088  * "arg" is advanced to the first non-white character after the name.
6089  * Return -1 if curly braces expansion failed.
6090  * Return 0 if something else is wrong.
6091  * If the name contains 'magic' {}'s, expand them and return the
6092  * expanded name in an allocated string via 'alias' - caller must free.
6093  */
6094     int
6095 get_name_len(
6096     char_u	**arg,
6097     char_u	**alias,
6098     int		evaluate,
6099     int		verbose)
6100 {
6101     int		len;
6102     char_u	*p;
6103     char_u	*expr_start;
6104     char_u	*expr_end;
6105 
6106     *alias = NULL;  /* default to no alias */
6107 
6108     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
6109 						  && (*arg)[2] == (int)KE_SNR)
6110     {
6111 	/* hard coded <SNR>, already translated */
6112 	*arg += 3;
6113 	return get_id_len(arg) + 3;
6114     }
6115     len = eval_fname_script(*arg);
6116     if (len > 0)
6117     {
6118 	/* literal "<SID>", "s:" or "<SNR>" */
6119 	*arg += len;
6120     }
6121 
6122     /*
6123      * Find the end of the name; check for {} construction.
6124      */
6125     p = find_name_end(*arg, &expr_start, &expr_end,
6126 					       len > 0 ? 0 : FNE_CHECK_START);
6127     if (expr_start != NULL)
6128     {
6129 	char_u	*temp_string;
6130 
6131 	if (!evaluate)
6132 	{
6133 	    len += (int)(p - *arg);
6134 	    *arg = skipwhite(p);
6135 	    return len;
6136 	}
6137 
6138 	/*
6139 	 * Include any <SID> etc in the expanded string:
6140 	 * Thus the -len here.
6141 	 */
6142 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
6143 	if (temp_string == NULL)
6144 	    return -1;
6145 	*alias = temp_string;
6146 	*arg = skipwhite(p);
6147 	return (int)STRLEN(temp_string);
6148     }
6149 
6150     len += get_id_len(arg);
6151     if (len == 0 && verbose)
6152 	EMSG2(_(e_invexpr2), *arg);
6153 
6154     return len;
6155 }
6156 
6157 /*
6158  * Find the end of a variable or function name, taking care of magic braces.
6159  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
6160  * start and end of the first magic braces item.
6161  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
6162  * Return a pointer to just after the name.  Equal to "arg" if there is no
6163  * valid name.
6164  */
6165     char_u *
6166 find_name_end(
6167     char_u	*arg,
6168     char_u	**expr_start,
6169     char_u	**expr_end,
6170     int		flags)
6171 {
6172     int		mb_nest = 0;
6173     int		br_nest = 0;
6174     char_u	*p;
6175     int		len;
6176 
6177     if (expr_start != NULL)
6178     {
6179 	*expr_start = NULL;
6180 	*expr_end = NULL;
6181     }
6182 
6183     /* Quick check for valid starting character. */
6184     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg) && *arg != '{')
6185 	return arg;
6186 
6187     for (p = arg; *p != NUL
6188 		    && (eval_isnamec(*p)
6189 			|| *p == '{'
6190 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
6191 			|| mb_nest != 0
6192 			|| br_nest != 0); MB_PTR_ADV(p))
6193     {
6194 	if (*p == '\'')
6195 	{
6196 	    /* skip over 'string' to avoid counting [ and ] inside it. */
6197 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
6198 		;
6199 	    if (*p == NUL)
6200 		break;
6201 	}
6202 	else if (*p == '"')
6203 	{
6204 	    /* skip over "str\"ing" to avoid counting [ and ] inside it. */
6205 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
6206 		if (*p == '\\' && p[1] != NUL)
6207 		    ++p;
6208 	    if (*p == NUL)
6209 		break;
6210 	}
6211 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
6212 	{
6213 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6214 	     * slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is. */
6215 	    len = (int)(p - arg);
6216 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
6217 		    || (len > 1 && p[-1] != '}'))
6218 		break;
6219 	}
6220 
6221 	if (mb_nest == 0)
6222 	{
6223 	    if (*p == '[')
6224 		++br_nest;
6225 	    else if (*p == ']')
6226 		--br_nest;
6227 	}
6228 
6229 	if (br_nest == 0)
6230 	{
6231 	    if (*p == '{')
6232 	    {
6233 		mb_nest++;
6234 		if (expr_start != NULL && *expr_start == NULL)
6235 		    *expr_start = p;
6236 	    }
6237 	    else if (*p == '}')
6238 	    {
6239 		mb_nest--;
6240 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
6241 		    *expr_end = p;
6242 	    }
6243 	}
6244     }
6245 
6246     return p;
6247 }
6248 
6249 /*
6250  * Expands out the 'magic' {}'s in a variable/function name.
6251  * Note that this can call itself recursively, to deal with
6252  * constructs like foo{bar}{baz}{bam}
6253  * The four pointer arguments point to "foo{expre}ss{ion}bar"
6254  *			"in_start"      ^
6255  *			"expr_start"	   ^
6256  *			"expr_end"		 ^
6257  *			"in_end"			    ^
6258  *
6259  * Returns a new allocated string, which the caller must free.
6260  * Returns NULL for failure.
6261  */
6262     static char_u *
6263 make_expanded_name(
6264     char_u	*in_start,
6265     char_u	*expr_start,
6266     char_u	*expr_end,
6267     char_u	*in_end)
6268 {
6269     char_u	c1;
6270     char_u	*retval = NULL;
6271     char_u	*temp_result;
6272     char_u	*nextcmd = NULL;
6273 
6274     if (expr_end == NULL || in_end == NULL)
6275 	return NULL;
6276     *expr_start	= NUL;
6277     *expr_end = NUL;
6278     c1 = *in_end;
6279     *in_end = NUL;
6280 
6281     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
6282     if (temp_result != NULL && nextcmd == NULL)
6283     {
6284 	retval = alloc((unsigned)(STRLEN(temp_result) + (expr_start - in_start)
6285 						   + (in_end - expr_end) + 1));
6286 	if (retval != NULL)
6287 	{
6288 	    STRCPY(retval, in_start);
6289 	    STRCAT(retval, temp_result);
6290 	    STRCAT(retval, expr_end + 1);
6291 	}
6292     }
6293     vim_free(temp_result);
6294 
6295     *in_end = c1;		/* put char back for error messages */
6296     *expr_start = '{';
6297     *expr_end = '}';
6298 
6299     if (retval != NULL)
6300     {
6301 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
6302 	if (expr_start != NULL)
6303 	{
6304 	    /* Further expansion! */
6305 	    temp_result = make_expanded_name(retval, expr_start,
6306 						       expr_end, temp_result);
6307 	    vim_free(retval);
6308 	    retval = temp_result;
6309 	}
6310     }
6311 
6312     return retval;
6313 }
6314 
6315 /*
6316  * Return TRUE if character "c" can be used in a variable or function name.
6317  * Does not include '{' or '}' for magic braces.
6318  */
6319     int
6320 eval_isnamec(int c)
6321 {
6322     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
6323 }
6324 
6325 /*
6326  * Return TRUE if character "c" can be used as the first character in a
6327  * variable or function name (excluding '{' and '}').
6328  */
6329     int
6330 eval_isnamec1(int c)
6331 {
6332     return (ASCII_ISALPHA(c) || c == '_');
6333 }
6334 
6335 /*
6336  * Set number v: variable to "val".
6337  */
6338     void
6339 set_vim_var_nr(int idx, varnumber_T val)
6340 {
6341     vimvars[idx].vv_nr = val;
6342 }
6343 
6344 /*
6345  * Get number v: variable value.
6346  */
6347     varnumber_T
6348 get_vim_var_nr(int idx)
6349 {
6350     return vimvars[idx].vv_nr;
6351 }
6352 
6353 /*
6354  * Get string v: variable value.  Uses a static buffer, can only be used once.
6355  * If the String variable has never been set, return an empty string.
6356  * Never returns NULL;
6357  */
6358     char_u *
6359 get_vim_var_str(int idx)
6360 {
6361     return get_tv_string(&vimvars[idx].vv_tv);
6362 }
6363 
6364 /*
6365  * Get List v: variable value.  Caller must take care of reference count when
6366  * needed.
6367  */
6368     list_T *
6369 get_vim_var_list(int idx)
6370 {
6371     return vimvars[idx].vv_list;
6372 }
6373 
6374 /*
6375  * Get Dict v: variable value.  Caller must take care of reference count when
6376  * needed.
6377  */
6378     dict_T *
6379 get_vim_var_dict(int idx)
6380 {
6381     return vimvars[idx].vv_dict;
6382 }
6383 
6384 /*
6385  * Set v:char to character "c".
6386  */
6387     void
6388 set_vim_var_char(int c)
6389 {
6390     char_u	buf[MB_MAXBYTES + 1];
6391 
6392 #ifdef FEAT_MBYTE
6393     if (has_mbyte)
6394 	buf[(*mb_char2bytes)(c, buf)] = NUL;
6395     else
6396 #endif
6397     {
6398 	buf[0] = c;
6399 	buf[1] = NUL;
6400     }
6401     set_vim_var_string(VV_CHAR, buf, -1);
6402 }
6403 
6404 /*
6405  * Set v:count to "count" and v:count1 to "count1".
6406  * When "set_prevcount" is TRUE first set v:prevcount from v:count.
6407  */
6408     void
6409 set_vcount(
6410     long	count,
6411     long	count1,
6412     int		set_prevcount)
6413 {
6414     if (set_prevcount)
6415 	vimvars[VV_PREVCOUNT].vv_nr = vimvars[VV_COUNT].vv_nr;
6416     vimvars[VV_COUNT].vv_nr = count;
6417     vimvars[VV_COUNT1].vv_nr = count1;
6418 }
6419 
6420 /*
6421  * Save variables that might be changed as a side effect.  Used when executing
6422  * a timer callback.
6423  */
6424     void
6425 save_vimvars(vimvars_save_T *vvsave)
6426 {
6427     vvsave->vv_prevcount = vimvars[VV_PREVCOUNT].vv_nr;
6428     vvsave->vv_count = vimvars[VV_COUNT].vv_nr;
6429     vvsave->vv_count1 = vimvars[VV_COUNT1].vv_nr;
6430 }
6431 
6432 /*
6433  * Restore variables saved by save_vimvars().
6434  */
6435     void
6436 restore_vimvars(vimvars_save_T *vvsave)
6437 {
6438     vimvars[VV_PREVCOUNT].vv_nr = vvsave->vv_prevcount;
6439     vimvars[VV_COUNT].vv_nr = vvsave->vv_count;
6440     vimvars[VV_COUNT1].vv_nr = vvsave->vv_count1;
6441 }
6442 
6443 /*
6444  * Set string v: variable to a copy of "val".
6445  */
6446     void
6447 set_vim_var_string(
6448     int		idx,
6449     char_u	*val,
6450     int		len)	    /* length of "val" to use or -1 (whole string) */
6451 {
6452     clear_tv(&vimvars[idx].vv_di.di_tv);
6453     vimvars[idx].vv_type = VAR_STRING;
6454     if (val == NULL)
6455 	vimvars[idx].vv_str = NULL;
6456     else if (len == -1)
6457 	vimvars[idx].vv_str = vim_strsave(val);
6458     else
6459 	vimvars[idx].vv_str = vim_strnsave(val, len);
6460 }
6461 
6462 /*
6463  * Set List v: variable to "val".
6464  */
6465     void
6466 set_vim_var_list(int idx, list_T *val)
6467 {
6468     clear_tv(&vimvars[idx].vv_di.di_tv);
6469     vimvars[idx].vv_type = VAR_LIST;
6470     vimvars[idx].vv_list = val;
6471     if (val != NULL)
6472 	++val->lv_refcount;
6473 }
6474 
6475 /*
6476  * Set Dictionary v: variable to "val".
6477  */
6478     void
6479 set_vim_var_dict(int idx, dict_T *val)
6480 {
6481     clear_tv(&vimvars[idx].vv_di.di_tv);
6482     vimvars[idx].vv_type = VAR_DICT;
6483     vimvars[idx].vv_dict = val;
6484     if (val != NULL)
6485     {
6486 	++val->dv_refcount;
6487 	dict_set_items_ro(val);
6488     }
6489 }
6490 
6491 /*
6492  * Set v:register if needed.
6493  */
6494     void
6495 set_reg_var(int c)
6496 {
6497     char_u	regname;
6498 
6499     if (c == 0 || c == ' ')
6500 	regname = '"';
6501     else
6502 	regname = c;
6503     /* Avoid free/alloc when the value is already right. */
6504     if (vimvars[VV_REG].vv_str == NULL || vimvars[VV_REG].vv_str[0] != c)
6505 	set_vim_var_string(VV_REG, &regname, 1);
6506 }
6507 
6508 /*
6509  * Get or set v:exception.  If "oldval" == NULL, return the current value.
6510  * Otherwise, restore the value to "oldval" and return NULL.
6511  * Must always be called in pairs to save and restore v:exception!  Does not
6512  * take care of memory allocations.
6513  */
6514     char_u *
6515 v_exception(char_u *oldval)
6516 {
6517     if (oldval == NULL)
6518 	return vimvars[VV_EXCEPTION].vv_str;
6519 
6520     vimvars[VV_EXCEPTION].vv_str = oldval;
6521     return NULL;
6522 }
6523 
6524 /*
6525  * Get or set v:throwpoint.  If "oldval" == NULL, return the current value.
6526  * Otherwise, restore the value to "oldval" and return NULL.
6527  * Must always be called in pairs to save and restore v:throwpoint!  Does not
6528  * take care of memory allocations.
6529  */
6530     char_u *
6531 v_throwpoint(char_u *oldval)
6532 {
6533     if (oldval == NULL)
6534 	return vimvars[VV_THROWPOINT].vv_str;
6535 
6536     vimvars[VV_THROWPOINT].vv_str = oldval;
6537     return NULL;
6538 }
6539 
6540 /*
6541  * Set v:cmdarg.
6542  * If "eap" != NULL, use "eap" to generate the value and return the old value.
6543  * If "oldarg" != NULL, restore the value to "oldarg" and return NULL.
6544  * Must always be called in pairs!
6545  */
6546     char_u *
6547 set_cmdarg(exarg_T *eap, char_u *oldarg)
6548 {
6549     char_u	*oldval;
6550     char_u	*newval;
6551     unsigned	len;
6552 
6553     oldval = vimvars[VV_CMDARG].vv_str;
6554     if (eap == NULL)
6555     {
6556 	vim_free(oldval);
6557 	vimvars[VV_CMDARG].vv_str = oldarg;
6558 	return NULL;
6559     }
6560 
6561     if (eap->force_bin == FORCE_BIN)
6562 	len = 6;
6563     else if (eap->force_bin == FORCE_NOBIN)
6564 	len = 8;
6565     else
6566 	len = 0;
6567 
6568     if (eap->read_edit)
6569 	len += 7;
6570 
6571     if (eap->force_ff != 0)
6572 	len += 10; /* " ++ff=unix" */
6573 # ifdef FEAT_MBYTE
6574     if (eap->force_enc != 0)
6575 	len += (unsigned)STRLEN(eap->cmd + eap->force_enc) + 7;
6576     if (eap->bad_char != 0)
6577 	len += 7 + 4;  /* " ++bad=" + "keep" or "drop" */
6578 # endif
6579 
6580     newval = alloc(len + 1);
6581     if (newval == NULL)
6582 	return NULL;
6583 
6584     if (eap->force_bin == FORCE_BIN)
6585 	sprintf((char *)newval, " ++bin");
6586     else if (eap->force_bin == FORCE_NOBIN)
6587 	sprintf((char *)newval, " ++nobin");
6588     else
6589 	*newval = NUL;
6590 
6591     if (eap->read_edit)
6592 	STRCAT(newval, " ++edit");
6593 
6594     if (eap->force_ff != 0)
6595 	sprintf((char *)newval + STRLEN(newval), " ++ff=%s",
6596 						eap->force_ff == 'u' ? "unix"
6597 						: eap->force_ff == 'd' ? "dos"
6598 						: "mac");
6599 #ifdef FEAT_MBYTE
6600     if (eap->force_enc != 0)
6601 	sprintf((char *)newval + STRLEN(newval), " ++enc=%s",
6602 					       eap->cmd + eap->force_enc);
6603     if (eap->bad_char == BAD_KEEP)
6604 	STRCPY(newval + STRLEN(newval), " ++bad=keep");
6605     else if (eap->bad_char == BAD_DROP)
6606 	STRCPY(newval + STRLEN(newval), " ++bad=drop");
6607     else if (eap->bad_char != 0)
6608 	sprintf((char *)newval + STRLEN(newval), " ++bad=%c", eap->bad_char);
6609 #endif
6610     vimvars[VV_CMDARG].vv_str = newval;
6611     return oldval;
6612 }
6613 
6614 /*
6615  * Get the value of internal variable "name".
6616  * Return OK or FAIL.  If OK is returned "rettv" must be cleared.
6617  */
6618     int
6619 get_var_tv(
6620     char_u	*name,
6621     int		len,		/* length of "name" */
6622     typval_T	*rettv,		/* NULL when only checking existence */
6623     dictitem_T	**dip,		/* non-NULL when typval's dict item is needed */
6624     int		verbose,	/* may give error message */
6625     int		no_autoload)	/* do not use script autoloading */
6626 {
6627     int		ret = OK;
6628     typval_T	*tv = NULL;
6629     dictitem_T	*v;
6630     int		cc;
6631 
6632     /* truncate the name, so that we can use strcmp() */
6633     cc = name[len];
6634     name[len] = NUL;
6635 
6636     /*
6637      * Check for user-defined variables.
6638      */
6639     v = find_var(name, NULL, no_autoload);
6640     if (v != NULL)
6641     {
6642 	tv = &v->di_tv;
6643 	if (dip != NULL)
6644 	    *dip = v;
6645     }
6646 
6647     if (tv == NULL)
6648     {
6649 	if (rettv != NULL && verbose)
6650 	    EMSG2(_(e_undefvar), name);
6651 	ret = FAIL;
6652     }
6653     else if (rettv != NULL)
6654 	copy_tv(tv, rettv);
6655 
6656     name[len] = cc;
6657 
6658     return ret;
6659 }
6660 
6661 /*
6662  * Check if variable "name[len]" is a local variable or an argument.
6663  * If so, "*eval_lavars_used" is set to TRUE.
6664  */
6665     static void
6666 check_vars(char_u *name, int len)
6667 {
6668     int		cc;
6669     char_u	*varname;
6670     hashtab_T	*ht;
6671 
6672     if (eval_lavars_used == NULL)
6673 	return;
6674 
6675     /* truncate the name, so that we can use strcmp() */
6676     cc = name[len];
6677     name[len] = NUL;
6678 
6679     ht = find_var_ht(name, &varname);
6680     if (ht == get_funccal_local_ht() || ht == get_funccal_args_ht())
6681     {
6682 	if (find_var(name, NULL, TRUE) != NULL)
6683 	    *eval_lavars_used = TRUE;
6684     }
6685 
6686     name[len] = cc;
6687 }
6688 
6689 /*
6690  * Handle expr[expr], expr[expr:expr] subscript and .name lookup.
6691  * Also handle function call with Funcref variable: func(expr)
6692  * Can all be combined: dict.func(expr)[idx]['func'](expr)
6693  */
6694     int
6695 handle_subscript(
6696     char_u	**arg,
6697     typval_T	*rettv,
6698     int		evaluate,	/* do more than finding the end */
6699     int		verbose)	/* give error messages */
6700 {
6701     int		ret = OK;
6702     dict_T	*selfdict = NULL;
6703     char_u	*s;
6704     int		len;
6705     typval_T	functv;
6706 
6707     while (ret == OK
6708 	    && (**arg == '['
6709 		|| (**arg == '.' && rettv->v_type == VAR_DICT)
6710 		|| (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
6711 					    || rettv->v_type == VAR_PARTIAL)))
6712 	    && !VIM_ISWHITE(*(*arg - 1)))
6713     {
6714 	if (**arg == '(')
6715 	{
6716 	    partial_T	*pt = NULL;
6717 
6718 	    /* need to copy the funcref so that we can clear rettv */
6719 	    if (evaluate)
6720 	    {
6721 		functv = *rettv;
6722 		rettv->v_type = VAR_UNKNOWN;
6723 
6724 		/* Invoke the function.  Recursive! */
6725 		if (functv.v_type == VAR_PARTIAL)
6726 		{
6727 		    pt = functv.vval.v_partial;
6728 		    s = partial_name(pt);
6729 		}
6730 		else
6731 		    s = functv.vval.v_string;
6732 	    }
6733 	    else
6734 		s = (char_u *)"";
6735 	    ret = get_func_tv(s, (int)STRLEN(s), rettv, arg,
6736 			curwin->w_cursor.lnum, curwin->w_cursor.lnum,
6737 			&len, evaluate, pt, selfdict);
6738 
6739 	    /* Clear the funcref afterwards, so that deleting it while
6740 	     * evaluating the arguments is possible (see test55). */
6741 	    if (evaluate)
6742 		clear_tv(&functv);
6743 
6744 	    /* Stop the expression evaluation when immediately aborting on
6745 	     * error, or when an interrupt occurred or an exception was thrown
6746 	     * but not caught. */
6747 	    if (aborting())
6748 	    {
6749 		if (ret == OK)
6750 		    clear_tv(rettv);
6751 		ret = FAIL;
6752 	    }
6753 	    dict_unref(selfdict);
6754 	    selfdict = NULL;
6755 	}
6756 	else /* **arg == '[' || **arg == '.' */
6757 	{
6758 	    dict_unref(selfdict);
6759 	    if (rettv->v_type == VAR_DICT)
6760 	    {
6761 		selfdict = rettv->vval.v_dict;
6762 		if (selfdict != NULL)
6763 		    ++selfdict->dv_refcount;
6764 	    }
6765 	    else
6766 		selfdict = NULL;
6767 	    if (eval_index(arg, rettv, evaluate, verbose) == FAIL)
6768 	    {
6769 		clear_tv(rettv);
6770 		ret = FAIL;
6771 	    }
6772 	}
6773     }
6774 
6775     /* Turn "dict.Func" into a partial for "Func" bound to "dict".
6776      * Don't do this when "Func" is already a partial that was bound
6777      * explicitly (pt_auto is FALSE). */
6778     if (selfdict != NULL
6779 	    && (rettv->v_type == VAR_FUNC
6780 		|| (rettv->v_type == VAR_PARTIAL
6781 		    && (rettv->vval.v_partial->pt_auto
6782 			|| rettv->vval.v_partial->pt_dict == NULL))))
6783 	selfdict = make_partial(selfdict, rettv);
6784 
6785     dict_unref(selfdict);
6786     return ret;
6787 }
6788 
6789 /*
6790  * Allocate memory for a variable type-value, and make it empty (0 or NULL
6791  * value).
6792  */
6793     typval_T *
6794 alloc_tv(void)
6795 {
6796     return (typval_T *)alloc_clear((unsigned)sizeof(typval_T));
6797 }
6798 
6799 /*
6800  * Allocate memory for a variable type-value, and assign a string to it.
6801  * The string "s" must have been allocated, it is consumed.
6802  * Return NULL for out of memory, the variable otherwise.
6803  */
6804     static typval_T *
6805 alloc_string_tv(char_u *s)
6806 {
6807     typval_T	*rettv;
6808 
6809     rettv = alloc_tv();
6810     if (rettv != NULL)
6811     {
6812 	rettv->v_type = VAR_STRING;
6813 	rettv->vval.v_string = s;
6814     }
6815     else
6816 	vim_free(s);
6817     return rettv;
6818 }
6819 
6820 /*
6821  * Free the memory for a variable type-value.
6822  */
6823     void
6824 free_tv(typval_T *varp)
6825 {
6826     if (varp != NULL)
6827     {
6828 	switch (varp->v_type)
6829 	{
6830 	    case VAR_FUNC:
6831 		func_unref(varp->vval.v_string);
6832 		/* FALLTHROUGH */
6833 	    case VAR_STRING:
6834 		vim_free(varp->vval.v_string);
6835 		break;
6836 	    case VAR_PARTIAL:
6837 		partial_unref(varp->vval.v_partial);
6838 		break;
6839 	    case VAR_LIST:
6840 		list_unref(varp->vval.v_list);
6841 		break;
6842 	    case VAR_DICT:
6843 		dict_unref(varp->vval.v_dict);
6844 		break;
6845 	    case VAR_JOB:
6846 #ifdef FEAT_JOB_CHANNEL
6847 		job_unref(varp->vval.v_job);
6848 		break;
6849 #endif
6850 	    case VAR_CHANNEL:
6851 #ifdef FEAT_JOB_CHANNEL
6852 		channel_unref(varp->vval.v_channel);
6853 		break;
6854 #endif
6855 	    case VAR_NUMBER:
6856 	    case VAR_FLOAT:
6857 	    case VAR_UNKNOWN:
6858 	    case VAR_SPECIAL:
6859 		break;
6860 	}
6861 	vim_free(varp);
6862     }
6863 }
6864 
6865 /*
6866  * Free the memory for a variable value and set the value to NULL or 0.
6867  */
6868     void
6869 clear_tv(typval_T *varp)
6870 {
6871     if (varp != NULL)
6872     {
6873 	switch (varp->v_type)
6874 	{
6875 	    case VAR_FUNC:
6876 		func_unref(varp->vval.v_string);
6877 		/* FALLTHROUGH */
6878 	    case VAR_STRING:
6879 		VIM_CLEAR(varp->vval.v_string);
6880 		break;
6881 	    case VAR_PARTIAL:
6882 		partial_unref(varp->vval.v_partial);
6883 		varp->vval.v_partial = NULL;
6884 		break;
6885 	    case VAR_LIST:
6886 		list_unref(varp->vval.v_list);
6887 		varp->vval.v_list = NULL;
6888 		break;
6889 	    case VAR_DICT:
6890 		dict_unref(varp->vval.v_dict);
6891 		varp->vval.v_dict = NULL;
6892 		break;
6893 	    case VAR_NUMBER:
6894 	    case VAR_SPECIAL:
6895 		varp->vval.v_number = 0;
6896 		break;
6897 	    case VAR_FLOAT:
6898 #ifdef FEAT_FLOAT
6899 		varp->vval.v_float = 0.0;
6900 		break;
6901 #endif
6902 	    case VAR_JOB:
6903 #ifdef FEAT_JOB_CHANNEL
6904 		job_unref(varp->vval.v_job);
6905 		varp->vval.v_job = NULL;
6906 #endif
6907 		break;
6908 	    case VAR_CHANNEL:
6909 #ifdef FEAT_JOB_CHANNEL
6910 		channel_unref(varp->vval.v_channel);
6911 		varp->vval.v_channel = NULL;
6912 #endif
6913 	    case VAR_UNKNOWN:
6914 		break;
6915 	}
6916 	varp->v_lock = 0;
6917     }
6918 }
6919 
6920 /*
6921  * Set the value of a variable to NULL without freeing items.
6922  */
6923     void
6924 init_tv(typval_T *varp)
6925 {
6926     if (varp != NULL)
6927 	vim_memset(varp, 0, sizeof(typval_T));
6928 }
6929 
6930 /*
6931  * Get the number value of a variable.
6932  * If it is a String variable, uses vim_str2nr().
6933  * For incompatible types, return 0.
6934  * get_tv_number_chk() is similar to get_tv_number(), but informs the
6935  * caller of incompatible types: it sets *denote to TRUE if "denote"
6936  * is not NULL or returns -1 otherwise.
6937  */
6938     varnumber_T
6939 get_tv_number(typval_T *varp)
6940 {
6941     int		error = FALSE;
6942 
6943     return get_tv_number_chk(varp, &error);	/* return 0L on error */
6944 }
6945 
6946     varnumber_T
6947 get_tv_number_chk(typval_T *varp, int *denote)
6948 {
6949     varnumber_T	n = 0L;
6950 
6951     switch (varp->v_type)
6952     {
6953 	case VAR_NUMBER:
6954 	    return varp->vval.v_number;
6955 	case VAR_FLOAT:
6956 #ifdef FEAT_FLOAT
6957 	    EMSG(_("E805: Using a Float as a Number"));
6958 	    break;
6959 #endif
6960 	case VAR_FUNC:
6961 	case VAR_PARTIAL:
6962 	    EMSG(_("E703: Using a Funcref as a Number"));
6963 	    break;
6964 	case VAR_STRING:
6965 	    if (varp->vval.v_string != NULL)
6966 		vim_str2nr(varp->vval.v_string, NULL, NULL,
6967 						    STR2NR_ALL, &n, NULL, 0);
6968 	    return n;
6969 	case VAR_LIST:
6970 	    EMSG(_("E745: Using a List as a Number"));
6971 	    break;
6972 	case VAR_DICT:
6973 	    EMSG(_("E728: Using a Dictionary as a Number"));
6974 	    break;
6975 	case VAR_SPECIAL:
6976 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
6977 	    break;
6978 	case VAR_JOB:
6979 #ifdef FEAT_JOB_CHANNEL
6980 	    EMSG(_("E910: Using a Job as a Number"));
6981 	    break;
6982 #endif
6983 	case VAR_CHANNEL:
6984 #ifdef FEAT_JOB_CHANNEL
6985 	    EMSG(_("E913: Using a Channel as a Number"));
6986 	    break;
6987 #endif
6988 	case VAR_UNKNOWN:
6989 	    internal_error("get_tv_number(UNKNOWN)");
6990 	    break;
6991     }
6992     if (denote == NULL)		/* useful for values that must be unsigned */
6993 	n = -1;
6994     else
6995 	*denote = TRUE;
6996     return n;
6997 }
6998 
6999 #ifdef FEAT_FLOAT
7000     float_T
7001 get_tv_float(typval_T *varp)
7002 {
7003     switch (varp->v_type)
7004     {
7005 	case VAR_NUMBER:
7006 	    return (float_T)(varp->vval.v_number);
7007 	case VAR_FLOAT:
7008 	    return varp->vval.v_float;
7009 	case VAR_FUNC:
7010 	case VAR_PARTIAL:
7011 	    EMSG(_("E891: Using a Funcref as a Float"));
7012 	    break;
7013 	case VAR_STRING:
7014 	    EMSG(_("E892: Using a String as a Float"));
7015 	    break;
7016 	case VAR_LIST:
7017 	    EMSG(_("E893: Using a List as a Float"));
7018 	    break;
7019 	case VAR_DICT:
7020 	    EMSG(_("E894: Using a Dictionary as a Float"));
7021 	    break;
7022 	case VAR_SPECIAL:
7023 	    EMSG(_("E907: Using a special value as a Float"));
7024 	    break;
7025 	case VAR_JOB:
7026 # ifdef FEAT_JOB_CHANNEL
7027 	    EMSG(_("E911: Using a Job as a Float"));
7028 	    break;
7029 # endif
7030 	case VAR_CHANNEL:
7031 # ifdef FEAT_JOB_CHANNEL
7032 	    EMSG(_("E914: Using a Channel as a Float"));
7033 	    break;
7034 # endif
7035 	case VAR_UNKNOWN:
7036 	    internal_error("get_tv_float(UNKNOWN)");
7037 	    break;
7038     }
7039     return 0;
7040 }
7041 #endif
7042 
7043 /*
7044  * Get the string value of a variable.
7045  * If it is a Number variable, the number is converted into a string.
7046  * get_tv_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7047  * get_tv_string_buf() uses a given buffer.
7048  * If the String variable has never been set, return an empty string.
7049  * Never returns NULL;
7050  * get_tv_string_chk() and get_tv_string_buf_chk() are similar, but return
7051  * NULL on error.
7052  */
7053     char_u *
7054 get_tv_string(typval_T *varp)
7055 {
7056     static char_u   mybuf[NUMBUFLEN];
7057 
7058     return get_tv_string_buf(varp, mybuf);
7059 }
7060 
7061     char_u *
7062 get_tv_string_buf(typval_T *varp, char_u *buf)
7063 {
7064     char_u	*res =  get_tv_string_buf_chk(varp, buf);
7065 
7066     return res != NULL ? res : (char_u *)"";
7067 }
7068 
7069 /*
7070  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7071  */
7072     char_u *
7073 get_tv_string_chk(typval_T *varp)
7074 {
7075     static char_u   mybuf[NUMBUFLEN];
7076 
7077     return get_tv_string_buf_chk(varp, mybuf);
7078 }
7079 
7080     char_u *
7081 get_tv_string_buf_chk(typval_T *varp, char_u *buf)
7082 {
7083     switch (varp->v_type)
7084     {
7085 	case VAR_NUMBER:
7086 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
7087 					    (long long)varp->vval.v_number);
7088 	    return buf;
7089 	case VAR_FUNC:
7090 	case VAR_PARTIAL:
7091 	    EMSG(_("E729: using Funcref as a String"));
7092 	    break;
7093 	case VAR_LIST:
7094 	    EMSG(_("E730: using List as a String"));
7095 	    break;
7096 	case VAR_DICT:
7097 	    EMSG(_("E731: using Dictionary as a String"));
7098 	    break;
7099 	case VAR_FLOAT:
7100 #ifdef FEAT_FLOAT
7101 	    EMSG(_(e_float_as_string));
7102 	    break;
7103 #endif
7104 	case VAR_STRING:
7105 	    if (varp->vval.v_string != NULL)
7106 		return varp->vval.v_string;
7107 	    return (char_u *)"";
7108 	case VAR_SPECIAL:
7109 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
7110 	    return buf;
7111 	case VAR_JOB:
7112 #ifdef FEAT_JOB_CHANNEL
7113 	    {
7114 		job_T *job = varp->vval.v_job;
7115 		char  *status;
7116 
7117 		if (job == NULL)
7118 		    return (char_u *)"no process";
7119 		status = job->jv_status == JOB_FAILED ? "fail"
7120 				: job->jv_status >= JOB_ENDED ? "dead"
7121 				: "run";
7122 # ifdef UNIX
7123 		vim_snprintf((char *)buf, NUMBUFLEN,
7124 			    "process %ld %s", (long)job->jv_pid, status);
7125 # elif defined(WIN32)
7126 		vim_snprintf((char *)buf, NUMBUFLEN,
7127 			    "process %ld %s",
7128 			    (long)job->jv_proc_info.dwProcessId,
7129 			    status);
7130 # else
7131 		/* fall-back */
7132 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
7133 # endif
7134 		return buf;
7135 	    }
7136 #endif
7137 	    break;
7138 	case VAR_CHANNEL:
7139 #ifdef FEAT_JOB_CHANNEL
7140 	    {
7141 		channel_T *channel = varp->vval.v_channel;
7142 		char      *status = channel_status(channel, -1);
7143 
7144 		if (channel == NULL)
7145 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
7146 		else
7147 		    vim_snprintf((char *)buf, NUMBUFLEN,
7148 				     "channel %d %s", channel->ch_id, status);
7149 		return buf;
7150 	    }
7151 #endif
7152 	    break;
7153 	case VAR_UNKNOWN:
7154 	    EMSG(_("E908: using an invalid value as a String"));
7155 	    break;
7156     }
7157     return NULL;
7158 }
7159 
7160 /*
7161  * Find variable "name" in the list of variables.
7162  * Return a pointer to it if found, NULL if not found.
7163  * Careful: "a:0" variables don't have a name.
7164  * When "htp" is not NULL we are writing to the variable, set "htp" to the
7165  * hashtab_T used.
7166  */
7167     dictitem_T *
7168 find_var(char_u *name, hashtab_T **htp, int no_autoload)
7169 {
7170     char_u	*varname;
7171     hashtab_T	*ht;
7172     dictitem_T	*ret = NULL;
7173 
7174     ht = find_var_ht(name, &varname);
7175     if (htp != NULL)
7176 	*htp = ht;
7177     if (ht == NULL)
7178 	return NULL;
7179     ret = find_var_in_ht(ht, *name, varname, no_autoload || htp != NULL);
7180     if (ret != NULL)
7181 	return ret;
7182 
7183     /* Search in parent scope for lambda */
7184     return find_var_in_scoped_ht(name, no_autoload || htp != NULL);
7185 }
7186 
7187 /*
7188  * Find variable "varname" in hashtab "ht" with name "htname".
7189  * Returns NULL if not found.
7190  */
7191     dictitem_T *
7192 find_var_in_ht(
7193     hashtab_T	*ht,
7194     int		htname,
7195     char_u	*varname,
7196     int		no_autoload)
7197 {
7198     hashitem_T	*hi;
7199 
7200     if (*varname == NUL)
7201     {
7202 	/* Must be something like "s:", otherwise "ht" would be NULL. */
7203 	switch (htname)
7204 	{
7205 	    case 's': return &SCRIPT_SV(current_SID)->sv_var;
7206 	    case 'g': return &globvars_var;
7207 	    case 'v': return &vimvars_var;
7208 	    case 'b': return &curbuf->b_bufvar;
7209 	    case 'w': return &curwin->w_winvar;
7210 	    case 't': return &curtab->tp_winvar;
7211 	    case 'l': return get_funccal_local_var();
7212 	    case 'a': return get_funccal_args_var();
7213 	}
7214 	return NULL;
7215     }
7216 
7217     hi = hash_find(ht, varname);
7218     if (HASHITEM_EMPTY(hi))
7219     {
7220 	/* For global variables we may try auto-loading the script.  If it
7221 	 * worked find the variable again.  Don't auto-load a script if it was
7222 	 * loaded already, otherwise it would be loaded every time when
7223 	 * checking if a function name is a Funcref variable. */
7224 	if (ht == &globvarht && !no_autoload)
7225 	{
7226 	    /* Note: script_autoload() may make "hi" invalid. It must either
7227 	     * be obtained again or not used. */
7228 	    if (!script_autoload(varname, FALSE) || aborting())
7229 		return NULL;
7230 	    hi = hash_find(ht, varname);
7231 	}
7232 	if (HASHITEM_EMPTY(hi))
7233 	    return NULL;
7234     }
7235     return HI2DI(hi);
7236 }
7237 
7238 /*
7239  * Find the hashtab used for a variable name.
7240  * Return NULL if the name is not valid.
7241  * Set "varname" to the start of name without ':'.
7242  */
7243     hashtab_T *
7244 find_var_ht(char_u *name, char_u **varname)
7245 {
7246     hashitem_T	*hi;
7247     hashtab_T	*ht;
7248 
7249     if (name[0] == NUL)
7250 	return NULL;
7251     if (name[1] != ':')
7252     {
7253 	/* The name must not start with a colon or #. */
7254 	if (name[0] == ':' || name[0] == AUTOLOAD_CHAR)
7255 	    return NULL;
7256 	*varname = name;
7257 
7258 	/* "version" is "v:version" in all scopes */
7259 	hi = hash_find(&compat_hashtab, name);
7260 	if (!HASHITEM_EMPTY(hi))
7261 	    return &compat_hashtab;
7262 
7263 	ht = get_funccal_local_ht();
7264 	if (ht == NULL)
7265 	    return &globvarht;			/* global variable */
7266 	return ht;				/* local variable */
7267     }
7268     *varname = name + 2;
7269     if (*name == 'g')				/* global variable */
7270 	return &globvarht;
7271     /* There must be no ':' or '#' in the rest of the name, unless g: is used
7272      */
7273     if (vim_strchr(name + 2, ':') != NULL
7274 			       || vim_strchr(name + 2, AUTOLOAD_CHAR) != NULL)
7275 	return NULL;
7276     if (*name == 'b')				/* buffer variable */
7277 	return &curbuf->b_vars->dv_hashtab;
7278     if (*name == 'w')				/* window variable */
7279 	return &curwin->w_vars->dv_hashtab;
7280     if (*name == 't')				/* tab page variable */
7281 	return &curtab->tp_vars->dv_hashtab;
7282     if (*name == 'v')				/* v: variable */
7283 	return &vimvarht;
7284     if (*name == 'a')				/* a: function argument */
7285 	return get_funccal_args_ht();
7286     if (*name == 'l')				/* l: local function variable */
7287 	return get_funccal_local_ht();
7288     if (*name == 's'				/* script variable */
7289 	    && current_SID > 0 && current_SID <= ga_scripts.ga_len)
7290 	return &SCRIPT_VARS(current_SID);
7291     return NULL;
7292 }
7293 
7294 /*
7295  * Get the string value of a (global/local) variable.
7296  * Note: see get_tv_string() for how long the pointer remains valid.
7297  * Returns NULL when it doesn't exist.
7298  */
7299     char_u *
7300 get_var_value(char_u *name)
7301 {
7302     dictitem_T	*v;
7303 
7304     v = find_var(name, NULL, FALSE);
7305     if (v == NULL)
7306 	return NULL;
7307     return get_tv_string(&v->di_tv);
7308 }
7309 
7310 /*
7311  * Allocate a new hashtab for a sourced script.  It will be used while
7312  * sourcing this script and when executing functions defined in the script.
7313  */
7314     void
7315 new_script_vars(scid_T id)
7316 {
7317     int		i;
7318     hashtab_T	*ht;
7319     scriptvar_T *sv;
7320 
7321     if (ga_grow(&ga_scripts, (int)(id - ga_scripts.ga_len)) == OK)
7322     {
7323 	/* Re-allocating ga_data means that an ht_array pointing to
7324 	 * ht_smallarray becomes invalid.  We can recognize this: ht_mask is
7325 	 * at its init value.  Also reset "v_dict", it's always the same. */
7326 	for (i = 1; i <= ga_scripts.ga_len; ++i)
7327 	{
7328 	    ht = &SCRIPT_VARS(i);
7329 	    if (ht->ht_mask == HT_INIT_SIZE - 1)
7330 		ht->ht_array = ht->ht_smallarray;
7331 	    sv = SCRIPT_SV(i);
7332 	    sv->sv_var.di_tv.vval.v_dict = &sv->sv_dict;
7333 	}
7334 
7335 	while (ga_scripts.ga_len < id)
7336 	{
7337 	    sv = SCRIPT_SV(ga_scripts.ga_len + 1) =
7338 		(scriptvar_T *)alloc_clear(sizeof(scriptvar_T));
7339 	    init_var_dict(&sv->sv_dict, &sv->sv_var, VAR_SCOPE);
7340 	    ++ga_scripts.ga_len;
7341 	}
7342     }
7343 }
7344 
7345 /*
7346  * Initialize dictionary "dict" as a scope and set variable "dict_var" to
7347  * point to it.
7348  */
7349     void
7350 init_var_dict(dict_T *dict, dictitem_T *dict_var, int scope)
7351 {
7352     hash_init(&dict->dv_hashtab);
7353     dict->dv_lock = 0;
7354     dict->dv_scope = scope;
7355     dict->dv_refcount = DO_NOT_FREE_CNT;
7356     dict->dv_copyID = 0;
7357     dict_var->di_tv.vval.v_dict = dict;
7358     dict_var->di_tv.v_type = VAR_DICT;
7359     dict_var->di_tv.v_lock = VAR_FIXED;
7360     dict_var->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
7361     dict_var->di_key[0] = NUL;
7362 }
7363 
7364 /*
7365  * Unreference a dictionary initialized by init_var_dict().
7366  */
7367     void
7368 unref_var_dict(dict_T *dict)
7369 {
7370     /* Now the dict needs to be freed if no one else is using it, go back to
7371      * normal reference counting. */
7372     dict->dv_refcount -= DO_NOT_FREE_CNT - 1;
7373     dict_unref(dict);
7374 }
7375 
7376 /*
7377  * Clean up a list of internal variables.
7378  * Frees all allocated variables and the value they contain.
7379  * Clears hashtab "ht", does not free it.
7380  */
7381     void
7382 vars_clear(hashtab_T *ht)
7383 {
7384     vars_clear_ext(ht, TRUE);
7385 }
7386 
7387 /*
7388  * Like vars_clear(), but only free the value if "free_val" is TRUE.
7389  */
7390     void
7391 vars_clear_ext(hashtab_T *ht, int free_val)
7392 {
7393     int		todo;
7394     hashitem_T	*hi;
7395     dictitem_T	*v;
7396 
7397     hash_lock(ht);
7398     todo = (int)ht->ht_used;
7399     for (hi = ht->ht_array; todo > 0; ++hi)
7400     {
7401 	if (!HASHITEM_EMPTY(hi))
7402 	{
7403 	    --todo;
7404 
7405 	    /* Free the variable.  Don't remove it from the hashtab,
7406 	     * ht_array might change then.  hash_clear() takes care of it
7407 	     * later. */
7408 	    v = HI2DI(hi);
7409 	    if (free_val)
7410 		clear_tv(&v->di_tv);
7411 	    if (v->di_flags & DI_FLAGS_ALLOC)
7412 		vim_free(v);
7413 	}
7414     }
7415     hash_clear(ht);
7416     ht->ht_used = 0;
7417 }
7418 
7419 /*
7420  * Delete a variable from hashtab "ht" at item "hi".
7421  * Clear the variable value and free the dictitem.
7422  */
7423     static void
7424 delete_var(hashtab_T *ht, hashitem_T *hi)
7425 {
7426     dictitem_T	*di = HI2DI(hi);
7427 
7428     hash_remove(ht, hi);
7429     clear_tv(&di->di_tv);
7430     vim_free(di);
7431 }
7432 
7433 /*
7434  * List the value of one internal variable.
7435  */
7436     static void
7437 list_one_var(dictitem_T *v, char_u *prefix, int *first)
7438 {
7439     char_u	*tofree;
7440     char_u	*s;
7441     char_u	numbuf[NUMBUFLEN];
7442 
7443     s = echo_string(&v->di_tv, &tofree, numbuf, get_copyID());
7444     list_one_var_a(prefix, v->di_key, v->di_tv.v_type,
7445 					 s == NULL ? (char_u *)"" : s, first);
7446     vim_free(tofree);
7447 }
7448 
7449     static void
7450 list_one_var_a(
7451     char_u	*prefix,
7452     char_u	*name,
7453     int		type,
7454     char_u	*string,
7455     int		*first)  /* when TRUE clear rest of screen and set to FALSE */
7456 {
7457     /* don't use msg() or msg_attr() to avoid overwriting "v:statusmsg" */
7458     msg_start();
7459     msg_puts(prefix);
7460     if (name != NULL)	/* "a:" vars don't have a name stored */
7461 	msg_puts(name);
7462     msg_putchar(' ');
7463     msg_advance(22);
7464     if (type == VAR_NUMBER)
7465 	msg_putchar('#');
7466     else if (type == VAR_FUNC || type == VAR_PARTIAL)
7467 	msg_putchar('*');
7468     else if (type == VAR_LIST)
7469     {
7470 	msg_putchar('[');
7471 	if (*string == '[')
7472 	    ++string;
7473     }
7474     else if (type == VAR_DICT)
7475     {
7476 	msg_putchar('{');
7477 	if (*string == '{')
7478 	    ++string;
7479     }
7480     else
7481 	msg_putchar(' ');
7482 
7483     msg_outtrans(string);
7484 
7485     if (type == VAR_FUNC || type == VAR_PARTIAL)
7486 	msg_puts((char_u *)"()");
7487     if (*first)
7488     {
7489 	msg_clr_eos();
7490 	*first = FALSE;
7491     }
7492 }
7493 
7494 /*
7495  * Set variable "name" to value in "tv".
7496  * If the variable already exists, the value is updated.
7497  * Otherwise the variable is created.
7498  */
7499     void
7500 set_var(
7501     char_u	*name,
7502     typval_T	*tv,
7503     int		copy)	    /* make copy of value in "tv" */
7504 {
7505     dictitem_T	*v;
7506     char_u	*varname;
7507     hashtab_T	*ht;
7508 
7509     ht = find_var_ht(name, &varname);
7510     if (ht == NULL || *varname == NUL)
7511     {
7512 	EMSG2(_(e_illvar), name);
7513 	return;
7514     }
7515     v = find_var_in_ht(ht, 0, varname, TRUE);
7516 
7517     /* Search in parent scope which is possible to reference from lambda */
7518     if (v == NULL)
7519 	v = find_var_in_scoped_ht(name, TRUE);
7520 
7521     if ((tv->v_type == VAR_FUNC || tv->v_type == VAR_PARTIAL)
7522 				      && var_check_func_name(name, v == NULL))
7523 	return;
7524 
7525     if (v != NULL)
7526     {
7527 	/* existing variable, need to clear the value */
7528 	if (var_check_ro(v->di_flags, name, FALSE)
7529 			       || tv_check_lock(v->di_tv.v_lock, name, FALSE))
7530 	    return;
7531 
7532 	/*
7533 	 * Handle setting internal v: variables separately where needed to
7534 	 * prevent changing the type.
7535 	 */
7536 	if (ht == &vimvarht)
7537 	{
7538 	    if (v->di_tv.v_type == VAR_STRING)
7539 	    {
7540 		vim_free(v->di_tv.vval.v_string);
7541 		if (copy || tv->v_type != VAR_STRING)
7542 		    v->di_tv.vval.v_string = vim_strsave(get_tv_string(tv));
7543 		else
7544 		{
7545 		    /* Take over the string to avoid an extra alloc/free. */
7546 		    v->di_tv.vval.v_string = tv->vval.v_string;
7547 		    tv->vval.v_string = NULL;
7548 		}
7549 		return;
7550 	    }
7551 	    else if (v->di_tv.v_type == VAR_NUMBER)
7552 	    {
7553 		v->di_tv.vval.v_number = get_tv_number(tv);
7554 		if (STRCMP(varname, "searchforward") == 0)
7555 		    set_search_direction(v->di_tv.vval.v_number ? '/' : '?');
7556 #ifdef FEAT_SEARCH_EXTRA
7557 		else if (STRCMP(varname, "hlsearch") == 0)
7558 		{
7559 		    no_hlsearch = !v->di_tv.vval.v_number;
7560 		    redraw_all_later(SOME_VALID);
7561 		}
7562 #endif
7563 		return;
7564 	    }
7565 	    else if (v->di_tv.v_type != tv->v_type)
7566 		internal_error("set_var()");
7567 	}
7568 
7569 	clear_tv(&v->di_tv);
7570     }
7571     else		    /* add a new variable */
7572     {
7573 	/* Can't add "v:" variable. */
7574 	if (ht == &vimvarht)
7575 	{
7576 	    EMSG2(_(e_illvar), name);
7577 	    return;
7578 	}
7579 
7580 	/* Make sure the variable name is valid. */
7581 	if (!valid_varname(varname))
7582 	    return;
7583 
7584 	v = (dictitem_T *)alloc((unsigned)(sizeof(dictitem_T)
7585 							  + STRLEN(varname)));
7586 	if (v == NULL)
7587 	    return;
7588 	STRCPY(v->di_key, varname);
7589 	if (hash_add(ht, DI2HIKEY(v)) == FAIL)
7590 	{
7591 	    vim_free(v);
7592 	    return;
7593 	}
7594 	v->di_flags = DI_FLAGS_ALLOC;
7595     }
7596 
7597     if (copy || tv->v_type == VAR_NUMBER || tv->v_type == VAR_FLOAT)
7598 	copy_tv(tv, &v->di_tv);
7599     else
7600     {
7601 	v->di_tv = *tv;
7602 	v->di_tv.v_lock = 0;
7603 	init_tv(tv);
7604     }
7605 }
7606 
7607 /*
7608  * Return TRUE if di_flags "flags" indicates variable "name" is read-only.
7609  * Also give an error message.
7610  */
7611     int
7612 var_check_ro(int flags, char_u *name, int use_gettext)
7613 {
7614     if (flags & DI_FLAGS_RO)
7615     {
7616 	EMSG2(_(e_readonlyvar), use_gettext ? (char_u *)_(name) : name);
7617 	return TRUE;
7618     }
7619     if ((flags & DI_FLAGS_RO_SBX) && sandbox)
7620     {
7621 	EMSG2(_(e_readonlysbx), use_gettext ? (char_u *)_(name) : name);
7622 	return TRUE;
7623     }
7624     return FALSE;
7625 }
7626 
7627 /*
7628  * Return TRUE if di_flags "flags" indicates variable "name" is fixed.
7629  * Also give an error message.
7630  */
7631     int
7632 var_check_fixed(int flags, char_u *name, int use_gettext)
7633 {
7634     if (flags & DI_FLAGS_FIX)
7635     {
7636 	EMSG2(_("E795: Cannot delete variable %s"),
7637 				      use_gettext ? (char_u *)_(name) : name);
7638 	return TRUE;
7639     }
7640     return FALSE;
7641 }
7642 
7643 /*
7644  * Check if a funcref is assigned to a valid variable name.
7645  * Return TRUE and give an error if not.
7646  */
7647     int
7648 var_check_func_name(
7649     char_u *name,    /* points to start of variable name */
7650     int    new_var)  /* TRUE when creating the variable */
7651 {
7652     /* Allow for w: b: s: and t:. */
7653     if (!(vim_strchr((char_u *)"wbst", name[0]) != NULL && name[1] == ':')
7654 	    && !ASCII_ISUPPER((name[0] != NUL && name[1] == ':')
7655 						     ? name[2] : name[0]))
7656     {
7657 	EMSG2(_("E704: Funcref variable name must start with a capital: %s"),
7658 									name);
7659 	return TRUE;
7660     }
7661     /* Don't allow hiding a function.  When "v" is not NULL we might be
7662      * assigning another function to the same var, the type is checked
7663      * below. */
7664     if (new_var && function_exists(name, FALSE))
7665     {
7666 	EMSG2(_("E705: Variable name conflicts with existing function: %s"),
7667 								    name);
7668 	return TRUE;
7669     }
7670     return FALSE;
7671 }
7672 
7673 /*
7674  * Check if a variable name is valid.
7675  * Return FALSE and give an error if not.
7676  */
7677     int
7678 valid_varname(char_u *varname)
7679 {
7680     char_u *p;
7681 
7682     for (p = varname; *p != NUL; ++p)
7683 	if (!eval_isnamec1(*p) && (p == varname || !VIM_ISDIGIT(*p))
7684 						   && *p != AUTOLOAD_CHAR)
7685 	{
7686 	    EMSG2(_(e_illvar), varname);
7687 	    return FALSE;
7688 	}
7689     return TRUE;
7690 }
7691 
7692 /*
7693  * Return TRUE if typeval "tv" is set to be locked (immutable).
7694  * Also give an error message, using "name" or _("name") when use_gettext is
7695  * TRUE.
7696  */
7697     int
7698 tv_check_lock(int lock, char_u *name, int use_gettext)
7699 {
7700     if (lock & VAR_LOCKED)
7701     {
7702 	EMSG2(_("E741: Value is locked: %s"),
7703 				name == NULL ? (char_u *)_("Unknown")
7704 					     : use_gettext ? (char_u *)_(name)
7705 					     : name);
7706 	return TRUE;
7707     }
7708     if (lock & VAR_FIXED)
7709     {
7710 	EMSG2(_("E742: Cannot change value of %s"),
7711 				name == NULL ? (char_u *)_("Unknown")
7712 					     : use_gettext ? (char_u *)_(name)
7713 					     : name);
7714 	return TRUE;
7715     }
7716     return FALSE;
7717 }
7718 
7719 /*
7720  * Copy the values from typval_T "from" to typval_T "to".
7721  * When needed allocates string or increases reference count.
7722  * Does not make a copy of a list or dict but copies the reference!
7723  * It is OK for "from" and "to" to point to the same item.  This is used to
7724  * make a copy later.
7725  */
7726     void
7727 copy_tv(typval_T *from, typval_T *to)
7728 {
7729     to->v_type = from->v_type;
7730     to->v_lock = 0;
7731     switch (from->v_type)
7732     {
7733 	case VAR_NUMBER:
7734 	case VAR_SPECIAL:
7735 	    to->vval.v_number = from->vval.v_number;
7736 	    break;
7737 	case VAR_FLOAT:
7738 #ifdef FEAT_FLOAT
7739 	    to->vval.v_float = from->vval.v_float;
7740 	    break;
7741 #endif
7742 	case VAR_JOB:
7743 #ifdef FEAT_JOB_CHANNEL
7744 	    to->vval.v_job = from->vval.v_job;
7745 	    if (to->vval.v_job != NULL)
7746 		++to->vval.v_job->jv_refcount;
7747 	    break;
7748 #endif
7749 	case VAR_CHANNEL:
7750 #ifdef FEAT_JOB_CHANNEL
7751 	    to->vval.v_channel = from->vval.v_channel;
7752 	    if (to->vval.v_channel != NULL)
7753 		++to->vval.v_channel->ch_refcount;
7754 	    break;
7755 #endif
7756 	case VAR_STRING:
7757 	case VAR_FUNC:
7758 	    if (from->vval.v_string == NULL)
7759 		to->vval.v_string = NULL;
7760 	    else
7761 	    {
7762 		to->vval.v_string = vim_strsave(from->vval.v_string);
7763 		if (from->v_type == VAR_FUNC)
7764 		    func_ref(to->vval.v_string);
7765 	    }
7766 	    break;
7767 	case VAR_PARTIAL:
7768 	    if (from->vval.v_partial == NULL)
7769 		to->vval.v_partial = NULL;
7770 	    else
7771 	    {
7772 		to->vval.v_partial = from->vval.v_partial;
7773 		++to->vval.v_partial->pt_refcount;
7774 	    }
7775 	    break;
7776 	case VAR_LIST:
7777 	    if (from->vval.v_list == NULL)
7778 		to->vval.v_list = NULL;
7779 	    else
7780 	    {
7781 		to->vval.v_list = from->vval.v_list;
7782 		++to->vval.v_list->lv_refcount;
7783 	    }
7784 	    break;
7785 	case VAR_DICT:
7786 	    if (from->vval.v_dict == NULL)
7787 		to->vval.v_dict = NULL;
7788 	    else
7789 	    {
7790 		to->vval.v_dict = from->vval.v_dict;
7791 		++to->vval.v_dict->dv_refcount;
7792 	    }
7793 	    break;
7794 	case VAR_UNKNOWN:
7795 	    internal_error("copy_tv(UNKNOWN)");
7796 	    break;
7797     }
7798 }
7799 
7800 /*
7801  * Make a copy of an item.
7802  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
7803  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
7804  * reference to an already copied list/dict can be used.
7805  * Returns FAIL or OK.
7806  */
7807     int
7808 item_copy(
7809     typval_T	*from,
7810     typval_T	*to,
7811     int		deep,
7812     int		copyID)
7813 {
7814     static int	recurse = 0;
7815     int		ret = OK;
7816 
7817     if (recurse >= DICT_MAXNEST)
7818     {
7819 	EMSG(_("E698: variable nested too deep for making a copy"));
7820 	return FAIL;
7821     }
7822     ++recurse;
7823 
7824     switch (from->v_type)
7825     {
7826 	case VAR_NUMBER:
7827 	case VAR_FLOAT:
7828 	case VAR_STRING:
7829 	case VAR_FUNC:
7830 	case VAR_PARTIAL:
7831 	case VAR_SPECIAL:
7832 	case VAR_JOB:
7833 	case VAR_CHANNEL:
7834 	    copy_tv(from, to);
7835 	    break;
7836 	case VAR_LIST:
7837 	    to->v_type = VAR_LIST;
7838 	    to->v_lock = 0;
7839 	    if (from->vval.v_list == NULL)
7840 		to->vval.v_list = NULL;
7841 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
7842 	    {
7843 		/* use the copy made earlier */
7844 		to->vval.v_list = from->vval.v_list->lv_copylist;
7845 		++to->vval.v_list->lv_refcount;
7846 	    }
7847 	    else
7848 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
7849 	    if (to->vval.v_list == NULL)
7850 		ret = FAIL;
7851 	    break;
7852 	case VAR_DICT:
7853 	    to->v_type = VAR_DICT;
7854 	    to->v_lock = 0;
7855 	    if (from->vval.v_dict == NULL)
7856 		to->vval.v_dict = NULL;
7857 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
7858 	    {
7859 		/* use the copy made earlier */
7860 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
7861 		++to->vval.v_dict->dv_refcount;
7862 	    }
7863 	    else
7864 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
7865 	    if (to->vval.v_dict == NULL)
7866 		ret = FAIL;
7867 	    break;
7868 	case VAR_UNKNOWN:
7869 	    internal_error("item_copy(UNKNOWN)");
7870 	    ret = FAIL;
7871     }
7872     --recurse;
7873     return ret;
7874 }
7875 
7876 /*
7877  * This function is used by f_input() and f_inputdialog() functions. The third
7878  * argument to f_input() specifies the type of completion to use at the
7879  * prompt. The third argument to f_inputdialog() specifies the value to return
7880  * when the user cancels the prompt.
7881  */
7882     void
7883 get_user_input(
7884     typval_T	*argvars,
7885     typval_T	*rettv,
7886     int		inputdialog,
7887     int		secret)
7888 {
7889     char_u	*prompt = get_tv_string_chk(&argvars[0]);
7890     char_u	*p = NULL;
7891     int		c;
7892     char_u	buf[NUMBUFLEN];
7893     int		cmd_silent_save = cmd_silent;
7894     char_u	*defstr = (char_u *)"";
7895     int		xp_type = EXPAND_NOTHING;
7896     char_u	*xp_arg = NULL;
7897 
7898     rettv->v_type = VAR_STRING;
7899     rettv->vval.v_string = NULL;
7900 
7901 #ifdef NO_CONSOLE_INPUT
7902     /* While starting up, there is no place to enter text. When running tests
7903      * with --not-a-term we assume feedkeys() will be used. */
7904     if (no_console_input() && !is_not_a_term())
7905 	return;
7906 #endif
7907 
7908     cmd_silent = FALSE;		/* Want to see the prompt. */
7909     if (prompt != NULL)
7910     {
7911 	/* Only the part of the message after the last NL is considered as
7912 	 * prompt for the command line */
7913 	p = vim_strrchr(prompt, '\n');
7914 	if (p == NULL)
7915 	    p = prompt;
7916 	else
7917 	{
7918 	    ++p;
7919 	    c = *p;
7920 	    *p = NUL;
7921 	    msg_start();
7922 	    msg_clr_eos();
7923 	    msg_puts_attr(prompt, echo_attr);
7924 	    msg_didout = FALSE;
7925 	    msg_starthere();
7926 	    *p = c;
7927 	}
7928 	cmdline_row = msg_row;
7929 
7930 	if (argvars[1].v_type != VAR_UNKNOWN)
7931 	{
7932 	    defstr = get_tv_string_buf_chk(&argvars[1], buf);
7933 	    if (defstr != NULL)
7934 		stuffReadbuffSpec(defstr);
7935 
7936 	    if (!inputdialog && argvars[2].v_type != VAR_UNKNOWN)
7937 	    {
7938 		char_u	*xp_name;
7939 		int	xp_namelen;
7940 		long	argt;
7941 
7942 		/* input() with a third argument: completion */
7943 		rettv->vval.v_string = NULL;
7944 
7945 		xp_name = get_tv_string_buf_chk(&argvars[2], buf);
7946 		if (xp_name == NULL)
7947 		    return;
7948 
7949 		xp_namelen = (int)STRLEN(xp_name);
7950 
7951 		if (parse_compl_arg(xp_name, xp_namelen, &xp_type, &argt,
7952 							     &xp_arg) == FAIL)
7953 		    return;
7954 	    }
7955 	}
7956 
7957 	if (defstr != NULL)
7958 	{
7959 	    int save_ex_normal_busy = ex_normal_busy;
7960 	    ex_normal_busy = 0;
7961 	    rettv->vval.v_string =
7962 		getcmdline_prompt(secret ? NUL : '@', p, echo_attr,
7963 							      xp_type, xp_arg);
7964 	    ex_normal_busy = save_ex_normal_busy;
7965 	}
7966 	if (inputdialog && rettv->vval.v_string == NULL
7967 		&& argvars[1].v_type != VAR_UNKNOWN
7968 		&& argvars[2].v_type != VAR_UNKNOWN)
7969 	    rettv->vval.v_string = vim_strsave(get_tv_string_buf(
7970 							   &argvars[2], buf));
7971 
7972 	vim_free(xp_arg);
7973 
7974 	/* since the user typed this, no need to wait for return */
7975 	need_wait_return = FALSE;
7976 	msg_didout = FALSE;
7977     }
7978     cmd_silent = cmd_silent_save;
7979 }
7980 
7981 /*
7982  * ":echo expr1 ..."	print each argument separated with a space, add a
7983  *			newline at the end.
7984  * ":echon expr1 ..."	print each argument plain.
7985  */
7986     void
7987 ex_echo(exarg_T *eap)
7988 {
7989     char_u	*arg = eap->arg;
7990     typval_T	rettv;
7991     char_u	*tofree;
7992     char_u	*p;
7993     int		needclr = TRUE;
7994     int		atstart = TRUE;
7995     char_u	numbuf[NUMBUFLEN];
7996 
7997     if (eap->skip)
7998 	++emsg_skip;
7999     while (*arg != NUL && *arg != '|' && *arg != '\n' && !got_int)
8000     {
8001 	/* If eval1() causes an error message the text from the command may
8002 	 * still need to be cleared. E.g., "echo 22,44". */
8003 	need_clr_eos = needclr;
8004 
8005 	p = arg;
8006 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8007 	{
8008 	    /*
8009 	     * Report the invalid expression unless the expression evaluation
8010 	     * has been cancelled due to an aborting error, an interrupt, or an
8011 	     * exception.
8012 	     */
8013 	    if (!aborting())
8014 		EMSG2(_(e_invexpr2), p);
8015 	    need_clr_eos = FALSE;
8016 	    break;
8017 	}
8018 	need_clr_eos = FALSE;
8019 
8020 	if (!eap->skip)
8021 	{
8022 	    if (atstart)
8023 	    {
8024 		atstart = FALSE;
8025 		/* Call msg_start() after eval1(), evaluating the expression
8026 		 * may cause a message to appear. */
8027 		if (eap->cmdidx == CMD_echo)
8028 		{
8029 		    /* Mark the saved text as finishing the line, so that what
8030 		     * follows is displayed on a new line when scrolling back
8031 		     * at the more prompt. */
8032 		    msg_sb_eol();
8033 		    msg_start();
8034 		}
8035 	    }
8036 	    else if (eap->cmdidx == CMD_echo)
8037 		msg_puts_attr((char_u *)" ", echo_attr);
8038 	    p = echo_string(&rettv, &tofree, numbuf, get_copyID());
8039 	    if (p != NULL)
8040 		for ( ; *p != NUL && !got_int; ++p)
8041 		{
8042 		    if (*p == '\n' || *p == '\r' || *p == TAB)
8043 		    {
8044 			if (*p != TAB && needclr)
8045 			{
8046 			    /* remove any text still there from the command */
8047 			    msg_clr_eos();
8048 			    needclr = FALSE;
8049 			}
8050 			msg_putchar_attr(*p, echo_attr);
8051 		    }
8052 		    else
8053 		    {
8054 #ifdef FEAT_MBYTE
8055 			if (has_mbyte)
8056 			{
8057 			    int i = (*mb_ptr2len)(p);
8058 
8059 			    (void)msg_outtrans_len_attr(p, i, echo_attr);
8060 			    p += i - 1;
8061 			}
8062 			else
8063 #endif
8064 			    (void)msg_outtrans_len_attr(p, 1, echo_attr);
8065 		    }
8066 		}
8067 	    vim_free(tofree);
8068 	}
8069 	clear_tv(&rettv);
8070 	arg = skipwhite(arg);
8071     }
8072     eap->nextcmd = check_nextcmd(arg);
8073 
8074     if (eap->skip)
8075 	--emsg_skip;
8076     else
8077     {
8078 	/* remove text that may still be there from the command */
8079 	if (needclr)
8080 	    msg_clr_eos();
8081 	if (eap->cmdidx == CMD_echo)
8082 	    msg_end();
8083     }
8084 }
8085 
8086 /*
8087  * ":echohl {name}".
8088  */
8089     void
8090 ex_echohl(exarg_T *eap)
8091 {
8092     echo_attr = syn_name2attr(eap->arg);
8093 }
8094 
8095 /*
8096  * ":execute expr1 ..."	execute the result of an expression.
8097  * ":echomsg expr1 ..."	Print a message
8098  * ":echoerr expr1 ..."	Print an error
8099  * Each gets spaces around each argument and a newline at the end for
8100  * echo commands
8101  */
8102     void
8103 ex_execute(exarg_T *eap)
8104 {
8105     char_u	*arg = eap->arg;
8106     typval_T	rettv;
8107     int		ret = OK;
8108     char_u	*p;
8109     garray_T	ga;
8110     int		len;
8111     int		save_did_emsg;
8112 
8113     ga_init2(&ga, 1, 80);
8114 
8115     if (eap->skip)
8116 	++emsg_skip;
8117     while (*arg != NUL && *arg != '|' && *arg != '\n')
8118     {
8119 	p = arg;
8120 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8121 	{
8122 	    /*
8123 	     * Report the invalid expression unless the expression evaluation
8124 	     * has been cancelled due to an aborting error, an interrupt, or an
8125 	     * exception.
8126 	     */
8127 	    if (!aborting())
8128 		EMSG2(_(e_invexpr2), p);
8129 	    ret = FAIL;
8130 	    break;
8131 	}
8132 
8133 	if (!eap->skip)
8134 	{
8135 	    p = get_tv_string(&rettv);
8136 	    len = (int)STRLEN(p);
8137 	    if (ga_grow(&ga, len + 2) == FAIL)
8138 	    {
8139 		clear_tv(&rettv);
8140 		ret = FAIL;
8141 		break;
8142 	    }
8143 	    if (ga.ga_len)
8144 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
8145 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
8146 	    ga.ga_len += len;
8147 	}
8148 
8149 	clear_tv(&rettv);
8150 	arg = skipwhite(arg);
8151     }
8152 
8153     if (ret != FAIL && ga.ga_data != NULL)
8154     {
8155 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
8156 	{
8157 	    /* Mark the already saved text as finishing the line, so that what
8158 	     * follows is displayed on a new line when scrolling back at the
8159 	     * more prompt. */
8160 	    msg_sb_eol();
8161 	}
8162 
8163 	if (eap->cmdidx == CMD_echomsg)
8164 	{
8165 	    MSG_ATTR(ga.ga_data, echo_attr);
8166 	    out_flush();
8167 	}
8168 	else if (eap->cmdidx == CMD_echoerr)
8169 	{
8170 	    /* We don't want to abort following commands, restore did_emsg. */
8171 	    save_did_emsg = did_emsg;
8172 	    EMSG((char_u *)ga.ga_data);
8173 	    if (!force_abort)
8174 		did_emsg = save_did_emsg;
8175 	}
8176 	else if (eap->cmdidx == CMD_execute)
8177 	    do_cmdline((char_u *)ga.ga_data,
8178 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
8179     }
8180 
8181     ga_clear(&ga);
8182 
8183     if (eap->skip)
8184 	--emsg_skip;
8185 
8186     eap->nextcmd = check_nextcmd(arg);
8187 }
8188 
8189 /*
8190  * Find window specified by "vp" in tabpage "tp".
8191  */
8192     win_T *
8193 find_win_by_nr(
8194     typval_T	*vp,
8195     tabpage_T	*tp)	/* NULL for current tab page */
8196 {
8197     win_T	*wp;
8198     int		nr;
8199 
8200     nr = (int)get_tv_number_chk(vp, NULL);
8201 
8202     if (nr < 0)
8203 	return NULL;
8204     if (nr == 0)
8205 	return curwin;
8206 
8207     FOR_ALL_WINDOWS_IN_TAB(tp, wp)
8208     {
8209 	if (nr >= LOWEST_WIN_ID)
8210 	{
8211 	    if (wp->w_id == nr)
8212 		return wp;
8213 	}
8214 	else if (--nr <= 0)
8215 	    break;
8216     }
8217     if (nr >= LOWEST_WIN_ID)
8218 	return NULL;
8219     return wp;
8220 }
8221 
8222 /*
8223  * Find window specified by "wvp" in tabpage "tvp".
8224  */
8225     win_T *
8226 find_tabwin(
8227     typval_T	*wvp,	/* VAR_UNKNOWN for current window */
8228     typval_T	*tvp)	/* VAR_UNKNOWN for current tab page */
8229 {
8230     win_T	*wp = NULL;
8231     tabpage_T	*tp = NULL;
8232     long	n;
8233 
8234     if (wvp->v_type != VAR_UNKNOWN)
8235     {
8236 	if (tvp->v_type != VAR_UNKNOWN)
8237 	{
8238 	    n = (long)get_tv_number(tvp);
8239 	    if (n >= 0)
8240 		tp = find_tabpage(n);
8241 	}
8242 	else
8243 	    tp = curtab;
8244 
8245 	if (tp != NULL)
8246 	    wp = find_win_by_nr(wvp, tp);
8247     }
8248     else
8249 	wp = curwin;
8250 
8251     return wp;
8252 }
8253 
8254 /*
8255  * getwinvar() and gettabwinvar()
8256  */
8257     void
8258 getwinvar(
8259     typval_T	*argvars,
8260     typval_T	*rettv,
8261     int		off)	    /* 1 for gettabwinvar() */
8262 {
8263     win_T	*win;
8264     char_u	*varname;
8265     dictitem_T	*v;
8266     tabpage_T	*tp = NULL;
8267     int		done = FALSE;
8268     win_T	*oldcurwin;
8269     tabpage_T	*oldtabpage;
8270     int		need_switch_win;
8271 
8272     if (off == 1)
8273 	tp = find_tabpage((int)get_tv_number_chk(&argvars[0], NULL));
8274     else
8275 	tp = curtab;
8276     win = find_win_by_nr(&argvars[off], tp);
8277     varname = get_tv_string_chk(&argvars[off + 1]);
8278     ++emsg_off;
8279 
8280     rettv->v_type = VAR_STRING;
8281     rettv->vval.v_string = NULL;
8282 
8283     if (win != NULL && varname != NULL)
8284     {
8285 	/* Set curwin to be our win, temporarily.  Also set the tabpage,
8286 	 * otherwise the window is not valid. Only do this when needed,
8287 	 * autocommands get blocked. */
8288 	need_switch_win = !(tp == curtab && win == curwin);
8289 	if (!need_switch_win
8290 		  || switch_win(&oldcurwin, &oldtabpage, win, tp, TRUE) == OK)
8291 	{
8292 	    if (*varname == '&')
8293 	    {
8294 		if (varname[1] == NUL)
8295 		{
8296 		    /* get all window-local options in a dict */
8297 		    dict_T	*opts = get_winbuf_options(FALSE);
8298 
8299 		    if (opts != NULL)
8300 		    {
8301 			rettv_dict_set(rettv, opts);
8302 			done = TRUE;
8303 		    }
8304 		}
8305 		else if (get_option_tv(&varname, rettv, 1) == OK)
8306 		    /* window-local-option */
8307 		    done = TRUE;
8308 	    }
8309 	    else
8310 	    {
8311 		/* Look up the variable. */
8312 		/* Let getwinvar({nr}, "") return the "w:" dictionary. */
8313 		v = find_var_in_ht(&win->w_vars->dv_hashtab, 'w',
8314 							      varname, FALSE);
8315 		if (v != NULL)
8316 		{
8317 		    copy_tv(&v->di_tv, rettv);
8318 		    done = TRUE;
8319 		}
8320 	    }
8321 	}
8322 
8323 	if (need_switch_win)
8324 	    /* restore previous notion of curwin */
8325 	    restore_win(oldcurwin, oldtabpage, TRUE);
8326     }
8327 
8328     if (!done && argvars[off + 2].v_type != VAR_UNKNOWN)
8329 	/* use the default return value */
8330 	copy_tv(&argvars[off + 2], rettv);
8331 
8332     --emsg_off;
8333 }
8334 
8335 /*
8336  * "setwinvar()" and "settabwinvar()" functions
8337  */
8338     void
8339 setwinvar(typval_T *argvars, typval_T *rettv UNUSED, int off)
8340 {
8341     win_T	*win;
8342     win_T	*save_curwin;
8343     tabpage_T	*save_curtab;
8344     int		need_switch_win;
8345     char_u	*varname, *winvarname;
8346     typval_T	*varp;
8347     char_u	nbuf[NUMBUFLEN];
8348     tabpage_T	*tp = NULL;
8349 
8350     if (check_restricted() || check_secure())
8351 	return;
8352 
8353     if (off == 1)
8354 	tp = find_tabpage((int)get_tv_number_chk(&argvars[0], NULL));
8355     else
8356 	tp = curtab;
8357     win = find_win_by_nr(&argvars[off], tp);
8358     varname = get_tv_string_chk(&argvars[off + 1]);
8359     varp = &argvars[off + 2];
8360 
8361     if (win != NULL && varname != NULL && varp != NULL)
8362     {
8363 	need_switch_win = !(tp == curtab && win == curwin);
8364 	if (!need_switch_win
8365 	       || switch_win(&save_curwin, &save_curtab, win, tp, TRUE) == OK)
8366 	{
8367 	    if (*varname == '&')
8368 	    {
8369 		long	numval;
8370 		char_u	*strval;
8371 		int		error = FALSE;
8372 
8373 		++varname;
8374 		numval = (long)get_tv_number_chk(varp, &error);
8375 		strval = get_tv_string_buf_chk(varp, nbuf);
8376 		if (!error && strval != NULL)
8377 		    set_option_value(varname, numval, strval, OPT_LOCAL);
8378 	    }
8379 	    else
8380 	    {
8381 		winvarname = alloc((unsigned)STRLEN(varname) + 3);
8382 		if (winvarname != NULL)
8383 		{
8384 		    STRCPY(winvarname, "w:");
8385 		    STRCPY(winvarname + 2, varname);
8386 		    set_var(winvarname, varp, TRUE);
8387 		    vim_free(winvarname);
8388 		}
8389 	    }
8390 	}
8391 	if (need_switch_win)
8392 	    restore_win(save_curwin, save_curtab, TRUE);
8393     }
8394 }
8395 
8396 /*
8397  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
8398  * "arg" points to the "&" or '+' when called, to "option" when returning.
8399  * Returns NULL when no option name found.  Otherwise pointer to the char
8400  * after the option name.
8401  */
8402     static char_u *
8403 find_option_end(char_u **arg, int *opt_flags)
8404 {
8405     char_u	*p = *arg;
8406 
8407     ++p;
8408     if (*p == 'g' && p[1] == ':')
8409     {
8410 	*opt_flags = OPT_GLOBAL;
8411 	p += 2;
8412     }
8413     else if (*p == 'l' && p[1] == ':')
8414     {
8415 	*opt_flags = OPT_LOCAL;
8416 	p += 2;
8417     }
8418     else
8419 	*opt_flags = 0;
8420 
8421     if (!ASCII_ISALPHA(*p))
8422 	return NULL;
8423     *arg = p;
8424 
8425     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
8426 	p += 4;	    /* termcap option */
8427     else
8428 	while (ASCII_ISALPHA(*p))
8429 	    ++p;
8430     return p;
8431 }
8432 
8433 /*
8434  * Return the autoload script name for a function or variable name.
8435  * Returns NULL when out of memory.
8436  */
8437     char_u *
8438 autoload_name(char_u *name)
8439 {
8440     char_u	*p;
8441     char_u	*scriptname;
8442 
8443     /* Get the script file name: replace '#' with '/', append ".vim". */
8444     scriptname = alloc((unsigned)(STRLEN(name) + 14));
8445     if (scriptname == NULL)
8446 	return FALSE;
8447     STRCPY(scriptname, "autoload/");
8448     STRCAT(scriptname, name);
8449     *vim_strrchr(scriptname, AUTOLOAD_CHAR) = NUL;
8450     STRCAT(scriptname, ".vim");
8451     while ((p = vim_strchr(scriptname, AUTOLOAD_CHAR)) != NULL)
8452 	*p = '/';
8453     return scriptname;
8454 }
8455 
8456 /*
8457  * If "name" has a package name try autoloading the script for it.
8458  * Return TRUE if a package was loaded.
8459  */
8460     int
8461 script_autoload(
8462     char_u	*name,
8463     int		reload)	    /* load script again when already loaded */
8464 {
8465     char_u	*p;
8466     char_u	*scriptname, *tofree;
8467     int		ret = FALSE;
8468     int		i;
8469 
8470     /* If there is no '#' after name[0] there is no package name. */
8471     p = vim_strchr(name, AUTOLOAD_CHAR);
8472     if (p == NULL || p == name)
8473 	return FALSE;
8474 
8475     tofree = scriptname = autoload_name(name);
8476 
8477     /* Find the name in the list of previously loaded package names.  Skip
8478      * "autoload/", it's always the same. */
8479     for (i = 0; i < ga_loaded.ga_len; ++i)
8480 	if (STRCMP(((char_u **)ga_loaded.ga_data)[i] + 9, scriptname + 9) == 0)
8481 	    break;
8482     if (!reload && i < ga_loaded.ga_len)
8483 	ret = FALSE;	    /* was loaded already */
8484     else
8485     {
8486 	/* Remember the name if it wasn't loaded already. */
8487 	if (i == ga_loaded.ga_len && ga_grow(&ga_loaded, 1) == OK)
8488 	{
8489 	    ((char_u **)ga_loaded.ga_data)[ga_loaded.ga_len++] = scriptname;
8490 	    tofree = NULL;
8491 	}
8492 
8493 	/* Try loading the package from $VIMRUNTIME/autoload/<name>.vim */
8494 	if (source_runtime(scriptname, 0) == OK)
8495 	    ret = TRUE;
8496     }
8497 
8498     vim_free(tofree);
8499     return ret;
8500 }
8501 
8502 #if defined(FEAT_VIMINFO) || defined(FEAT_SESSION)
8503 typedef enum
8504 {
8505     VAR_FLAVOUR_DEFAULT,	/* doesn't start with uppercase */
8506     VAR_FLAVOUR_SESSION,	/* starts with uppercase, some lower */
8507     VAR_FLAVOUR_VIMINFO		/* all uppercase */
8508 } var_flavour_T;
8509 
8510 static var_flavour_T var_flavour(char_u *varname);
8511 
8512     static var_flavour_T
8513 var_flavour(char_u *varname)
8514 {
8515     char_u *p = varname;
8516 
8517     if (ASCII_ISUPPER(*p))
8518     {
8519 	while (*(++p))
8520 	    if (ASCII_ISLOWER(*p))
8521 		return VAR_FLAVOUR_SESSION;
8522 	return VAR_FLAVOUR_VIMINFO;
8523     }
8524     else
8525 	return VAR_FLAVOUR_DEFAULT;
8526 }
8527 #endif
8528 
8529 #if defined(FEAT_VIMINFO) || defined(PROTO)
8530 /*
8531  * Restore global vars that start with a capital from the viminfo file
8532  */
8533     int
8534 read_viminfo_varlist(vir_T *virp, int writing)
8535 {
8536     char_u	*tab;
8537     int		type = VAR_NUMBER;
8538     typval_T	tv;
8539     void	*save_funccal;
8540 
8541     if (!writing && (find_viminfo_parameter('!') != NULL))
8542     {
8543 	tab = vim_strchr(virp->vir_line + 1, '\t');
8544 	if (tab != NULL)
8545 	{
8546 	    *tab++ = '\0';	/* isolate the variable name */
8547 	    switch (*tab)
8548 	    {
8549 		case 'S': type = VAR_STRING; break;
8550 #ifdef FEAT_FLOAT
8551 		case 'F': type = VAR_FLOAT; break;
8552 #endif
8553 		case 'D': type = VAR_DICT; break;
8554 		case 'L': type = VAR_LIST; break;
8555 		case 'X': type = VAR_SPECIAL; break;
8556 	    }
8557 
8558 	    tab = vim_strchr(tab, '\t');
8559 	    if (tab != NULL)
8560 	    {
8561 		tv.v_type = type;
8562 		if (type == VAR_STRING || type == VAR_DICT || type == VAR_LIST)
8563 		    tv.vval.v_string = viminfo_readstring(virp,
8564 				       (int)(tab - virp->vir_line + 1), TRUE);
8565 #ifdef FEAT_FLOAT
8566 		else if (type == VAR_FLOAT)
8567 		    (void)string2float(tab + 1, &tv.vval.v_float);
8568 #endif
8569 		else
8570 		    tv.vval.v_number = atol((char *)tab + 1);
8571 		if (type == VAR_DICT || type == VAR_LIST)
8572 		{
8573 		    typval_T *etv = eval_expr(tv.vval.v_string, NULL);
8574 
8575 		    if (etv == NULL)
8576 			/* Failed to parse back the dict or list, use it as a
8577 			 * string. */
8578 			tv.v_type = VAR_STRING;
8579 		    else
8580 		    {
8581 			vim_free(tv.vval.v_string);
8582 			tv = *etv;
8583 			vim_free(etv);
8584 		    }
8585 		}
8586 
8587 		/* when in a function use global variables */
8588 		save_funccal = clear_current_funccal();
8589 		set_var(virp->vir_line + 1, &tv, FALSE);
8590 		restore_current_funccal(save_funccal);
8591 
8592 		if (tv.v_type == VAR_STRING)
8593 		    vim_free(tv.vval.v_string);
8594 		else if (tv.v_type == VAR_DICT || tv.v_type == VAR_LIST)
8595 		    clear_tv(&tv);
8596 	    }
8597 	}
8598     }
8599 
8600     return viminfo_readline(virp);
8601 }
8602 
8603 /*
8604  * Write global vars that start with a capital to the viminfo file
8605  */
8606     void
8607 write_viminfo_varlist(FILE *fp)
8608 {
8609     hashitem_T	*hi;
8610     dictitem_T	*this_var;
8611     int		todo;
8612     char	*s = "";
8613     char_u	*p;
8614     char_u	*tofree;
8615     char_u	numbuf[NUMBUFLEN];
8616 
8617     if (find_viminfo_parameter('!') == NULL)
8618 	return;
8619 
8620     fputs(_("\n# global variables:\n"), fp);
8621 
8622     todo = (int)globvarht.ht_used;
8623     for (hi = globvarht.ht_array; todo > 0; ++hi)
8624     {
8625 	if (!HASHITEM_EMPTY(hi))
8626 	{
8627 	    --todo;
8628 	    this_var = HI2DI(hi);
8629 	    if (var_flavour(this_var->di_key) == VAR_FLAVOUR_VIMINFO)
8630 	    {
8631 		switch (this_var->di_tv.v_type)
8632 		{
8633 		    case VAR_STRING: s = "STR"; break;
8634 		    case VAR_NUMBER: s = "NUM"; break;
8635 		    case VAR_FLOAT:  s = "FLO"; break;
8636 		    case VAR_DICT:   s = "DIC"; break;
8637 		    case VAR_LIST:   s = "LIS"; break;
8638 		    case VAR_SPECIAL: s = "XPL"; break;
8639 
8640 		    case VAR_UNKNOWN:
8641 		    case VAR_FUNC:
8642 		    case VAR_PARTIAL:
8643 		    case VAR_JOB:
8644 		    case VAR_CHANNEL:
8645 				     continue;
8646 		}
8647 		fprintf(fp, "!%s\t%s\t", this_var->di_key, s);
8648 		p = echo_string(&this_var->di_tv, &tofree, numbuf, 0);
8649 		if (p != NULL)
8650 		    viminfo_writestring(fp, p);
8651 		vim_free(tofree);
8652 	    }
8653 	}
8654     }
8655 }
8656 #endif
8657 
8658 #if defined(FEAT_SESSION) || defined(PROTO)
8659     int
8660 store_session_globals(FILE *fd)
8661 {
8662     hashitem_T	*hi;
8663     dictitem_T	*this_var;
8664     int		todo;
8665     char_u	*p, *t;
8666 
8667     todo = (int)globvarht.ht_used;
8668     for (hi = globvarht.ht_array; todo > 0; ++hi)
8669     {
8670 	if (!HASHITEM_EMPTY(hi))
8671 	{
8672 	    --todo;
8673 	    this_var = HI2DI(hi);
8674 	    if ((this_var->di_tv.v_type == VAR_NUMBER
8675 			|| this_var->di_tv.v_type == VAR_STRING)
8676 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
8677 	    {
8678 		/* Escape special characters with a backslash.  Turn a LF and
8679 		 * CR into \n and \r. */
8680 		p = vim_strsave_escaped(get_tv_string(&this_var->di_tv),
8681 							(char_u *)"\\\"\n\r");
8682 		if (p == NULL)	    /* out of memory */
8683 		    break;
8684 		for (t = p; *t != NUL; ++t)
8685 		    if (*t == '\n')
8686 			*t = 'n';
8687 		    else if (*t == '\r')
8688 			*t = 'r';
8689 		if ((fprintf(fd, "let %s = %c%s%c",
8690 				this_var->di_key,
8691 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
8692 									: ' ',
8693 				p,
8694 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
8695 								   : ' ') < 0)
8696 			|| put_eol(fd) == FAIL)
8697 		{
8698 		    vim_free(p);
8699 		    return FAIL;
8700 		}
8701 		vim_free(p);
8702 	    }
8703 #ifdef FEAT_FLOAT
8704 	    else if (this_var->di_tv.v_type == VAR_FLOAT
8705 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
8706 	    {
8707 		float_T f = this_var->di_tv.vval.v_float;
8708 		int sign = ' ';
8709 
8710 		if (f < 0)
8711 		{
8712 		    f = -f;
8713 		    sign = '-';
8714 		}
8715 		if ((fprintf(fd, "let %s = %c%f",
8716 					       this_var->di_key, sign, f) < 0)
8717 			|| put_eol(fd) == FAIL)
8718 		    return FAIL;
8719 	    }
8720 #endif
8721 	}
8722     }
8723     return OK;
8724 }
8725 #endif
8726 
8727 /*
8728  * Display script name where an item was last set.
8729  * Should only be invoked when 'verbose' is non-zero.
8730  */
8731     void
8732 last_set_msg(scid_T scriptID)
8733 {
8734     char_u *p;
8735 
8736     if (scriptID != 0)
8737     {
8738 	p = home_replace_save(NULL, get_scriptname(scriptID));
8739 	if (p != NULL)
8740 	{
8741 	    verbose_enter();
8742 	    MSG_PUTS(_("\n\tLast set from "));
8743 	    MSG_PUTS(p);
8744 	    vim_free(p);
8745 	    verbose_leave();
8746 	}
8747     }
8748 }
8749 
8750 /* reset v:option_new, v:option_old and v:option_type */
8751     void
8752 reset_v_option_vars(void)
8753 {
8754     set_vim_var_string(VV_OPTION_NEW,  NULL, -1);
8755     set_vim_var_string(VV_OPTION_OLD,  NULL, -1);
8756     set_vim_var_string(VV_OPTION_TYPE, NULL, -1);
8757 }
8758 
8759 /*
8760  * Prepare "gap" for an assert error and add the sourcing position.
8761  */
8762     void
8763 prepare_assert_error(garray_T *gap)
8764 {
8765     char buf[NUMBUFLEN];
8766 
8767     ga_init2(gap, 1, 100);
8768     if (sourcing_name != NULL)
8769     {
8770 	ga_concat(gap, sourcing_name);
8771 	if (sourcing_lnum > 0)
8772 	    ga_concat(gap, (char_u *)" ");
8773     }
8774     if (sourcing_lnum > 0)
8775     {
8776 	sprintf(buf, "line %ld", (long)sourcing_lnum);
8777 	ga_concat(gap, (char_u *)buf);
8778     }
8779     if (sourcing_name != NULL || sourcing_lnum > 0)
8780 	ga_concat(gap, (char_u *)": ");
8781 }
8782 
8783 /*
8784  * Add an assert error to v:errors.
8785  */
8786     void
8787 assert_error(garray_T *gap)
8788 {
8789     struct vimvar   *vp = &vimvars[VV_ERRORS];
8790 
8791     if (vp->vv_type != VAR_LIST || vimvars[VV_ERRORS].vv_list == NULL)
8792 	/* Make sure v:errors is a list. */
8793 	set_vim_var_list(VV_ERRORS, list_alloc());
8794     list_append_string(vimvars[VV_ERRORS].vv_list, gap->ga_data, gap->ga_len);
8795 }
8796 
8797     int
8798 assert_equal_common(typval_T *argvars, assert_type_T atype)
8799 {
8800     garray_T	ga;
8801 
8802     if (tv_equal(&argvars[0], &argvars[1], FALSE, FALSE)
8803 						   != (atype == ASSERT_EQUAL))
8804     {
8805 	prepare_assert_error(&ga);
8806 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
8807 								       atype);
8808 	assert_error(&ga);
8809 	ga_clear(&ga);
8810 	return 1;
8811     }
8812     return 0;
8813 }
8814 
8815     int
8816 assert_equalfile(typval_T *argvars)
8817 {
8818     char_u	buf1[NUMBUFLEN];
8819     char_u	buf2[NUMBUFLEN];
8820     char_u	*fname1 = get_tv_string_buf_chk(&argvars[0], buf1);
8821     char_u	*fname2 = get_tv_string_buf_chk(&argvars[1], buf2);
8822     garray_T	ga;
8823     FILE	*fd1;
8824     FILE	*fd2;
8825 
8826     if (fname1 == NULL || fname2 == NULL)
8827 	return 0;
8828 
8829     IObuff[0] = NUL;
8830     fd1 = mch_fopen((char *)fname1, READBIN);
8831     if (fd1 == NULL)
8832     {
8833 	vim_snprintf((char *)IObuff, IOSIZE, (char *)e_notread, fname1);
8834     }
8835     else
8836     {
8837 	fd2 = mch_fopen((char *)fname2, READBIN);
8838 	if (fd2 == NULL)
8839 	{
8840 	    fclose(fd1);
8841 	    vim_snprintf((char *)IObuff, IOSIZE, (char *)e_notread, fname2);
8842 	}
8843 	else
8844 	{
8845 	    int c1, c2;
8846 	    long count = 0;
8847 
8848 	    for (;;)
8849 	    {
8850 		c1 = fgetc(fd1);
8851 		c2 = fgetc(fd2);
8852 		if (c1 == EOF)
8853 		{
8854 		    if (c2 != EOF)
8855 			STRCPY(IObuff, "first file is shorter");
8856 		    break;
8857 		}
8858 		else if (c2 == EOF)
8859 		{
8860 		    STRCPY(IObuff, "second file is shorter");
8861 		    break;
8862 		}
8863 		else if (c1 != c2)
8864 		{
8865 		    vim_snprintf((char *)IObuff, IOSIZE,
8866 					      "difference at byte %ld", count);
8867 		    break;
8868 		}
8869 		++count;
8870 	    }
8871 	    fclose(fd1);
8872 	    fclose(fd2);
8873 	}
8874     }
8875     if (IObuff[0] != NUL)
8876     {
8877 	prepare_assert_error(&ga);
8878 	ga_concat(&ga, IObuff);
8879 	assert_error(&ga);
8880 	ga_clear(&ga);
8881 	return 1;
8882     }
8883     return 0;
8884 }
8885 
8886     int
8887 assert_match_common(typval_T *argvars, assert_type_T atype)
8888 {
8889     garray_T	ga;
8890     char_u	buf1[NUMBUFLEN];
8891     char_u	buf2[NUMBUFLEN];
8892     char_u	*pat = get_tv_string_buf_chk(&argvars[0], buf1);
8893     char_u	*text = get_tv_string_buf_chk(&argvars[1], buf2);
8894 
8895     if (pat == NULL || text == NULL)
8896 	EMSG(_(e_invarg));
8897     else if (pattern_match(pat, text, FALSE) != (atype == ASSERT_MATCH))
8898     {
8899 	prepare_assert_error(&ga);
8900 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
8901 									atype);
8902 	assert_error(&ga);
8903 	ga_clear(&ga);
8904 	return 1;
8905     }
8906     return 0;
8907 }
8908 
8909     int
8910 assert_inrange(typval_T *argvars)
8911 {
8912     garray_T	ga;
8913     int		error = FALSE;
8914     varnumber_T	lower = get_tv_number_chk(&argvars[0], &error);
8915     varnumber_T	upper = get_tv_number_chk(&argvars[1], &error);
8916     varnumber_T	actual = get_tv_number_chk(&argvars[2], &error);
8917     char_u	*tofree;
8918     char	msg[200];
8919     char_u	numbuf[NUMBUFLEN];
8920 
8921     if (error)
8922 	return 0;
8923     if (actual < lower || actual > upper)
8924     {
8925 	prepare_assert_error(&ga);
8926 	if (argvars[3].v_type != VAR_UNKNOWN)
8927 	{
8928 	    ga_concat(&ga, tv2string(&argvars[3], &tofree, numbuf, 0));
8929 	    vim_free(tofree);
8930 	}
8931 	else
8932 	{
8933 	    vim_snprintf(msg, 200, "Expected range %ld - %ld, but got %ld",
8934 				       (long)lower, (long)upper, (long)actual);
8935 	    ga_concat(&ga, (char_u *)msg);
8936 	}
8937 	assert_error(&ga);
8938 	ga_clear(&ga);
8939 	return 1;
8940     }
8941     return 0;
8942 }
8943 
8944 /*
8945  * Common for assert_true() and assert_false().
8946  * Return non-zero for failure.
8947  */
8948     int
8949 assert_bool(typval_T *argvars, int isTrue)
8950 {
8951     int		error = FALSE;
8952     garray_T	ga;
8953 
8954     if (argvars[0].v_type == VAR_SPECIAL
8955 	    && argvars[0].vval.v_number == (isTrue ? VVAL_TRUE : VVAL_FALSE))
8956 	return 0;
8957     if (argvars[0].v_type != VAR_NUMBER
8958 	    || (get_tv_number_chk(&argvars[0], &error) == 0) == isTrue
8959 	    || error)
8960     {
8961 	prepare_assert_error(&ga);
8962 	fill_assert_error(&ga, &argvars[1],
8963 		(char_u *)(isTrue ? "True" : "False"),
8964 		NULL, &argvars[0], ASSERT_OTHER);
8965 	assert_error(&ga);
8966 	ga_clear(&ga);
8967 	return 1;
8968     }
8969     return 0;
8970 }
8971 
8972     int
8973 assert_report(typval_T *argvars)
8974 {
8975     garray_T	ga;
8976 
8977     prepare_assert_error(&ga);
8978     ga_concat(&ga, get_tv_string(&argvars[0]));
8979     assert_error(&ga);
8980     ga_clear(&ga);
8981     return 1;
8982 }
8983 
8984     int
8985 assert_exception(typval_T *argvars)
8986 {
8987     garray_T	ga;
8988     char_u	*error = get_tv_string_chk(&argvars[0]);
8989 
8990     if (vimvars[VV_EXCEPTION].vv_str == NULL)
8991     {
8992 	prepare_assert_error(&ga);
8993 	ga_concat(&ga, (char_u *)"v:exception is not set");
8994 	assert_error(&ga);
8995 	ga_clear(&ga);
8996 	return 1;
8997     }
8998     else if (error != NULL
8999 	&& strstr((char *)vimvars[VV_EXCEPTION].vv_str, (char *)error) == NULL)
9000     {
9001 	prepare_assert_error(&ga);
9002 	fill_assert_error(&ga, &argvars[1], NULL, &argvars[0],
9003 				  &vimvars[VV_EXCEPTION].vv_tv, ASSERT_OTHER);
9004 	assert_error(&ga);
9005 	ga_clear(&ga);
9006 	return 1;
9007     }
9008     return 0;
9009 }
9010 
9011     int
9012 assert_beeps(typval_T *argvars)
9013 {
9014     char_u	*cmd = get_tv_string_chk(&argvars[0]);
9015     garray_T	ga;
9016     int		ret = 0;
9017 
9018     called_vim_beep = FALSE;
9019     suppress_errthrow = TRUE;
9020     emsg_silent = FALSE;
9021     do_cmdline_cmd(cmd);
9022     if (!called_vim_beep)
9023     {
9024 	prepare_assert_error(&ga);
9025 	ga_concat(&ga, (char_u *)"command did not beep: ");
9026 	ga_concat(&ga, cmd);
9027 	assert_error(&ga);
9028 	ga_clear(&ga);
9029 	ret = 1;
9030     }
9031 
9032     suppress_errthrow = FALSE;
9033     emsg_on_display = FALSE;
9034     return ret;
9035 }
9036 
9037     int
9038 assert_fails(typval_T *argvars)
9039 {
9040     char_u	*cmd = get_tv_string_chk(&argvars[0]);
9041     garray_T	ga;
9042     int		ret = 0;
9043 
9044     called_emsg = FALSE;
9045     suppress_errthrow = TRUE;
9046     emsg_silent = TRUE;
9047     do_cmdline_cmd(cmd);
9048     if (!called_emsg)
9049     {
9050 	prepare_assert_error(&ga);
9051 	ga_concat(&ga, (char_u *)"command did not fail: ");
9052 	ga_concat(&ga, cmd);
9053 	assert_error(&ga);
9054 	ga_clear(&ga);
9055 	ret = 1;
9056     }
9057     else if (argvars[1].v_type != VAR_UNKNOWN)
9058     {
9059 	char_u	buf[NUMBUFLEN];
9060 	char	*error = (char *)get_tv_string_buf_chk(&argvars[1], buf);
9061 
9062 	if (error == NULL
9063 		  || strstr((char *)vimvars[VV_ERRMSG].vv_str, error) == NULL)
9064 	{
9065 	    prepare_assert_error(&ga);
9066 	    fill_assert_error(&ga, &argvars[2], NULL, &argvars[1],
9067 				     &vimvars[VV_ERRMSG].vv_tv, ASSERT_OTHER);
9068 	    assert_error(&ga);
9069 	    ga_clear(&ga);
9070 	ret = 1;
9071 	}
9072     }
9073 
9074     called_emsg = FALSE;
9075     suppress_errthrow = FALSE;
9076     emsg_silent = FALSE;
9077     emsg_on_display = FALSE;
9078     set_vim_var_string(VV_ERRMSG, NULL, 0);
9079     return ret;
9080 }
9081 
9082 /*
9083  * Append "str" to "gap", escaping unprintable characters.
9084  * Changes NL to \n, CR to \r, etc.
9085  */
9086     static void
9087 ga_concat_esc(garray_T *gap, char_u *str)
9088 {
9089     char_u  *p;
9090     char_u  buf[NUMBUFLEN];
9091 
9092     if (str == NULL)
9093     {
9094 	ga_concat(gap, (char_u *)"NULL");
9095 	return;
9096     }
9097 
9098     for (p = str; *p != NUL; ++p)
9099 	switch (*p)
9100 	{
9101 	    case BS: ga_concat(gap, (char_u *)"\\b"); break;
9102 	    case ESC: ga_concat(gap, (char_u *)"\\e"); break;
9103 	    case FF: ga_concat(gap, (char_u *)"\\f"); break;
9104 	    case NL: ga_concat(gap, (char_u *)"\\n"); break;
9105 	    case TAB: ga_concat(gap, (char_u *)"\\t"); break;
9106 	    case CAR: ga_concat(gap, (char_u *)"\\r"); break;
9107 	    case '\\': ga_concat(gap, (char_u *)"\\\\"); break;
9108 	    default:
9109 		if (*p < ' ')
9110 		{
9111 		    vim_snprintf((char *)buf, NUMBUFLEN, "\\x%02x", *p);
9112 		    ga_concat(gap, buf);
9113 		}
9114 		else
9115 		    ga_append(gap, *p);
9116 		break;
9117 	}
9118 }
9119 
9120 /*
9121  * Fill "gap" with information about an assert error.
9122  */
9123     void
9124 fill_assert_error(
9125     garray_T	*gap,
9126     typval_T	*opt_msg_tv,
9127     char_u      *exp_str,
9128     typval_T	*exp_tv,
9129     typval_T	*got_tv,
9130     assert_type_T atype)
9131 {
9132     char_u	numbuf[NUMBUFLEN];
9133     char_u	*tofree;
9134 
9135     if (opt_msg_tv->v_type != VAR_UNKNOWN)
9136     {
9137 	ga_concat(gap, echo_string(opt_msg_tv, &tofree, numbuf, 0));
9138 	vim_free(tofree);
9139 	ga_concat(gap, (char_u *)": ");
9140     }
9141 
9142     if (atype == ASSERT_MATCH || atype == ASSERT_NOTMATCH)
9143 	ga_concat(gap, (char_u *)"Pattern ");
9144     else if (atype == ASSERT_NOTEQUAL)
9145 	ga_concat(gap, (char_u *)"Expected not equal to ");
9146     else
9147 	ga_concat(gap, (char_u *)"Expected ");
9148     if (exp_str == NULL)
9149     {
9150 	ga_concat_esc(gap, tv2string(exp_tv, &tofree, numbuf, 0));
9151 	vim_free(tofree);
9152     }
9153     else
9154 	ga_concat_esc(gap, exp_str);
9155     if (atype != ASSERT_NOTEQUAL)
9156     {
9157 	if (atype == ASSERT_MATCH)
9158 	    ga_concat(gap, (char_u *)" does not match ");
9159 	else if (atype == ASSERT_NOTMATCH)
9160 	    ga_concat(gap, (char_u *)" does match ");
9161 	else
9162 	    ga_concat(gap, (char_u *)" but got ");
9163 	ga_concat_esc(gap, tv2string(got_tv, &tofree, numbuf, 0));
9164 	vim_free(tofree);
9165     }
9166 }
9167 
9168 /*
9169  * Compare "typ1" and "typ2".  Put the result in "typ1".
9170  */
9171     int
9172 typval_compare(
9173     typval_T	*typ1,   /* first operand */
9174     typval_T	*typ2,   /* second operand */
9175     exptype_T	type,    /* operator */
9176     int		type_is, /* TRUE for "is" and "isnot" */
9177     int		ic)      /* ignore case */
9178 {
9179     int		i;
9180     varnumber_T	n1, n2;
9181     char_u	*s1, *s2;
9182     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
9183 
9184     if (type_is && typ1->v_type != typ2->v_type)
9185     {
9186 	/* For "is" a different type always means FALSE, for "notis"
9187 	    * it means TRUE. */
9188 	n1 = (type == TYPE_NEQUAL);
9189     }
9190     else if (typ1->v_type == VAR_LIST || typ2->v_type == VAR_LIST)
9191     {
9192 	if (type_is)
9193 	{
9194 	    n1 = (typ1->v_type == typ2->v_type
9195 			    && typ1->vval.v_list == typ2->vval.v_list);
9196 	    if (type == TYPE_NEQUAL)
9197 		n1 = !n1;
9198 	}
9199 	else if (typ1->v_type != typ2->v_type
9200 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
9201 	{
9202 	    if (typ1->v_type != typ2->v_type)
9203 		EMSG(_("E691: Can only compare List with List"));
9204 	    else
9205 		EMSG(_("E692: Invalid operation for List"));
9206 	    clear_tv(typ1);
9207 	    return FAIL;
9208 	}
9209 	else
9210 	{
9211 	    /* Compare two Lists for being equal or unequal. */
9212 	    n1 = list_equal(typ1->vval.v_list, typ2->vval.v_list,
9213 							    ic, FALSE);
9214 	    if (type == TYPE_NEQUAL)
9215 		n1 = !n1;
9216 	}
9217     }
9218 
9219     else if (typ1->v_type == VAR_DICT || typ2->v_type == VAR_DICT)
9220     {
9221 	if (type_is)
9222 	{
9223 	    n1 = (typ1->v_type == typ2->v_type
9224 			    && typ1->vval.v_dict == typ2->vval.v_dict);
9225 	    if (type == TYPE_NEQUAL)
9226 		n1 = !n1;
9227 	}
9228 	else if (typ1->v_type != typ2->v_type
9229 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
9230 	{
9231 	    if (typ1->v_type != typ2->v_type)
9232 		EMSG(_("E735: Can only compare Dictionary with Dictionary"));
9233 	    else
9234 		EMSG(_("E736: Invalid operation for Dictionary"));
9235 	    clear_tv(typ1);
9236 	    return FAIL;
9237 	}
9238 	else
9239 	{
9240 	    /* Compare two Dictionaries for being equal or unequal. */
9241 	    n1 = dict_equal(typ1->vval.v_dict, typ2->vval.v_dict,
9242 							    ic, FALSE);
9243 	    if (type == TYPE_NEQUAL)
9244 		n1 = !n1;
9245 	}
9246     }
9247 
9248     else if (typ1->v_type == VAR_FUNC || typ2->v_type == VAR_FUNC
9249 	|| typ1->v_type == VAR_PARTIAL || typ2->v_type == VAR_PARTIAL)
9250     {
9251 	if (type != TYPE_EQUAL && type != TYPE_NEQUAL)
9252 	{
9253 	    EMSG(_("E694: Invalid operation for Funcrefs"));
9254 	    clear_tv(typ1);
9255 	    return FAIL;
9256 	}
9257 	if ((typ1->v_type == VAR_PARTIAL
9258 					&& typ1->vval.v_partial == NULL)
9259 		|| (typ2->v_type == VAR_PARTIAL
9260 					&& typ2->vval.v_partial == NULL))
9261 	    /* when a partial is NULL assume not equal */
9262 	    n1 = FALSE;
9263 	else if (type_is)
9264 	{
9265 	    if (typ1->v_type == VAR_FUNC && typ2->v_type == VAR_FUNC)
9266 		/* strings are considered the same if their value is
9267 		    * the same */
9268 		n1 = tv_equal(typ1, typ2, ic, FALSE);
9269 	    else if (typ1->v_type == VAR_PARTIAL
9270 					&& typ2->v_type == VAR_PARTIAL)
9271 		n1 = (typ1->vval.v_partial == typ2->vval.v_partial);
9272 	    else
9273 		n1 = FALSE;
9274 	}
9275 	else
9276 	    n1 = tv_equal(typ1, typ2, ic, FALSE);
9277 	if (type == TYPE_NEQUAL)
9278 	    n1 = !n1;
9279     }
9280 
9281 #ifdef FEAT_FLOAT
9282     /*
9283 	* If one of the two variables is a float, compare as a float.
9284 	* When using "=~" or "!~", always compare as string.
9285 	*/
9286     else if ((typ1->v_type == VAR_FLOAT || typ2->v_type == VAR_FLOAT)
9287 	    && type != TYPE_MATCH && type != TYPE_NOMATCH)
9288     {
9289 	float_T f1, f2;
9290 
9291 	if (typ1->v_type == VAR_FLOAT)
9292 	    f1 = typ1->vval.v_float;
9293 	else
9294 	    f1 = get_tv_number(typ1);
9295 	if (typ2->v_type == VAR_FLOAT)
9296 	    f2 = typ2->vval.v_float;
9297 	else
9298 	    f2 = get_tv_number(typ2);
9299 	n1 = FALSE;
9300 	switch (type)
9301 	{
9302 	    case TYPE_EQUAL:    n1 = (f1 == f2); break;
9303 	    case TYPE_NEQUAL:   n1 = (f1 != f2); break;
9304 	    case TYPE_GREATER:  n1 = (f1 > f2); break;
9305 	    case TYPE_GEQUAL:   n1 = (f1 >= f2); break;
9306 	    case TYPE_SMALLER:  n1 = (f1 < f2); break;
9307 	    case TYPE_SEQUAL:   n1 = (f1 <= f2); break;
9308 	    case TYPE_UNKNOWN:
9309 	    case TYPE_MATCH:
9310 	    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
9311 	}
9312     }
9313 #endif
9314 
9315     /*
9316 	* If one of the two variables is a number, compare as a number.
9317 	* When using "=~" or "!~", always compare as string.
9318 	*/
9319     else if ((typ1->v_type == VAR_NUMBER || typ2->v_type == VAR_NUMBER)
9320 	    && type != TYPE_MATCH && type != TYPE_NOMATCH)
9321     {
9322 	n1 = get_tv_number(typ1);
9323 	n2 = get_tv_number(typ2);
9324 	switch (type)
9325 	{
9326 	    case TYPE_EQUAL:    n1 = (n1 == n2); break;
9327 	    case TYPE_NEQUAL:   n1 = (n1 != n2); break;
9328 	    case TYPE_GREATER:  n1 = (n1 > n2); break;
9329 	    case TYPE_GEQUAL:   n1 = (n1 >= n2); break;
9330 	    case TYPE_SMALLER:  n1 = (n1 < n2); break;
9331 	    case TYPE_SEQUAL:   n1 = (n1 <= n2); break;
9332 	    case TYPE_UNKNOWN:
9333 	    case TYPE_MATCH:
9334 	    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
9335 	}
9336     }
9337     else
9338     {
9339 	s1 = get_tv_string_buf(typ1, buf1);
9340 	s2 = get_tv_string_buf(typ2, buf2);
9341 	if (type != TYPE_MATCH && type != TYPE_NOMATCH)
9342 	    i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
9343 	else
9344 	    i = 0;
9345 	n1 = FALSE;
9346 	switch (type)
9347 	{
9348 	    case TYPE_EQUAL:    n1 = (i == 0); break;
9349 	    case TYPE_NEQUAL:   n1 = (i != 0); break;
9350 	    case TYPE_GREATER:  n1 = (i > 0); break;
9351 	    case TYPE_GEQUAL:   n1 = (i >= 0); break;
9352 	    case TYPE_SMALLER:  n1 = (i < 0); break;
9353 	    case TYPE_SEQUAL:   n1 = (i <= 0); break;
9354 
9355 	    case TYPE_MATCH:
9356 	    case TYPE_NOMATCH:
9357 		    n1 = pattern_match(s2, s1, ic);
9358 		    if (type == TYPE_NOMATCH)
9359 			n1 = !n1;
9360 		    break;
9361 
9362 	    case TYPE_UNKNOWN:  break;  /* avoid gcc warning */
9363 	}
9364     }
9365     clear_tv(typ1);
9366     typ1->v_type = VAR_NUMBER;
9367     typ1->vval.v_number = n1;
9368 
9369     return OK;
9370 }
9371 
9372     char_u *
9373 typval_tostring(typval_T *arg)
9374 {
9375     char_u	*tofree;
9376     char_u	numbuf[NUMBUFLEN];
9377     char_u	*ret = NULL;
9378 
9379     if (arg == NULL)
9380 	return vim_strsave((char_u *)"(does not exist)");
9381     ret = tv2string(arg, &tofree, numbuf, 0);
9382     /* Make a copy if we have a value but it's not in allocated memory. */
9383     if (ret != NULL && tofree == NULL)
9384 	ret = vim_strsave(ret);
9385     return ret;
9386 }
9387 
9388     int
9389 var_exists(char_u *var)
9390 {
9391     char_u	*name;
9392     char_u	*tofree;
9393     typval_T    tv;
9394     int		len = 0;
9395     int		n = FALSE;
9396 
9397     /* get_name_len() takes care of expanding curly braces */
9398     name = var;
9399     len = get_name_len(&var, &tofree, TRUE, FALSE);
9400     if (len > 0)
9401     {
9402 	if (tofree != NULL)
9403 	    name = tofree;
9404 	n = (get_var_tv(name, len, &tv, NULL, FALSE, TRUE) == OK);
9405 	if (n)
9406 	{
9407 	    /* handle d.key, l[idx], f(expr) */
9408 	    n = (handle_subscript(&var, &tv, TRUE, FALSE) == OK);
9409 	    if (n)
9410 		clear_tv(&tv);
9411 	}
9412     }
9413     if (*var != NUL)
9414 	n = FALSE;
9415 
9416     vim_free(tofree);
9417     return n;
9418 }
9419 
9420 #endif /* FEAT_EVAL */
9421 
9422 
9423 #if defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) || defined(PROTO)
9424 
9425 #ifdef WIN3264
9426 /*
9427  * Functions for ":8" filename modifier: get 8.3 version of a filename.
9428  */
9429 static int get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen);
9430 static int shortpath_for_invalid_fname(char_u **fname, char_u **bufp, int *fnamelen);
9431 static int shortpath_for_partial(char_u **fnamep, char_u **bufp, int *fnamelen);
9432 
9433 /*
9434  * Get the short path (8.3) for the filename in "fnamep".
9435  * Only works for a valid file name.
9436  * When the path gets longer "fnamep" is changed and the allocated buffer
9437  * is put in "bufp".
9438  * *fnamelen is the length of "fnamep" and set to 0 for a nonexistent path.
9439  * Returns OK on success, FAIL on failure.
9440  */
9441     static int
9442 get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen)
9443 {
9444     int		l, len;
9445     char_u	*newbuf;
9446 
9447     len = *fnamelen;
9448     l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, len);
9449     if (l > len - 1)
9450     {
9451 	/* If that doesn't work (not enough space), then save the string
9452 	 * and try again with a new buffer big enough. */
9453 	newbuf = vim_strnsave(*fnamep, l);
9454 	if (newbuf == NULL)
9455 	    return FAIL;
9456 
9457 	vim_free(*bufp);
9458 	*fnamep = *bufp = newbuf;
9459 
9460 	/* Really should always succeed, as the buffer is big enough. */
9461 	l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, l+1);
9462     }
9463 
9464     *fnamelen = l;
9465     return OK;
9466 }
9467 
9468 /*
9469  * Get the short path (8.3) for the filename in "fname". The converted
9470  * path is returned in "bufp".
9471  *
9472  * Some of the directories specified in "fname" may not exist. This function
9473  * will shorten the existing directories at the beginning of the path and then
9474  * append the remaining non-existing path.
9475  *
9476  * fname - Pointer to the filename to shorten.  On return, contains the
9477  *	   pointer to the shortened pathname
9478  * bufp -  Pointer to an allocated buffer for the filename.
9479  * fnamelen - Length of the filename pointed to by fname
9480  *
9481  * Returns OK on success (or nothing done) and FAIL on failure (out of memory).
9482  */
9483     static int
9484 shortpath_for_invalid_fname(
9485     char_u	**fname,
9486     char_u	**bufp,
9487     int		*fnamelen)
9488 {
9489     char_u	*short_fname, *save_fname, *pbuf_unused;
9490     char_u	*endp, *save_endp;
9491     char_u	ch;
9492     int		old_len, len;
9493     int		new_len, sfx_len;
9494     int		retval = OK;
9495 
9496     /* Make a copy */
9497     old_len = *fnamelen;
9498     save_fname = vim_strnsave(*fname, old_len);
9499     pbuf_unused = NULL;
9500     short_fname = NULL;
9501 
9502     endp = save_fname + old_len - 1; /* Find the end of the copy */
9503     save_endp = endp;
9504 
9505     /*
9506      * Try shortening the supplied path till it succeeds by removing one
9507      * directory at a time from the tail of the path.
9508      */
9509     len = 0;
9510     for (;;)
9511     {
9512 	/* go back one path-separator */
9513 	while (endp > save_fname && !after_pathsep(save_fname, endp + 1))
9514 	    --endp;
9515 	if (endp <= save_fname)
9516 	    break;		/* processed the complete path */
9517 
9518 	/*
9519 	 * Replace the path separator with a NUL and try to shorten the
9520 	 * resulting path.
9521 	 */
9522 	ch = *endp;
9523 	*endp = 0;
9524 	short_fname = save_fname;
9525 	len = (int)STRLEN(short_fname) + 1;
9526 	if (get_short_pathname(&short_fname, &pbuf_unused, &len) == FAIL)
9527 	{
9528 	    retval = FAIL;
9529 	    goto theend;
9530 	}
9531 	*endp = ch;	/* preserve the string */
9532 
9533 	if (len > 0)
9534 	    break;	/* successfully shortened the path */
9535 
9536 	/* failed to shorten the path. Skip the path separator */
9537 	--endp;
9538     }
9539 
9540     if (len > 0)
9541     {
9542 	/*
9543 	 * Succeeded in shortening the path. Now concatenate the shortened
9544 	 * path with the remaining path at the tail.
9545 	 */
9546 
9547 	/* Compute the length of the new path. */
9548 	sfx_len = (int)(save_endp - endp) + 1;
9549 	new_len = len + sfx_len;
9550 
9551 	*fnamelen = new_len;
9552 	vim_free(*bufp);
9553 	if (new_len > old_len)
9554 	{
9555 	    /* There is not enough space in the currently allocated string,
9556 	     * copy it to a buffer big enough. */
9557 	    *fname = *bufp = vim_strnsave(short_fname, new_len);
9558 	    if (*fname == NULL)
9559 	    {
9560 		retval = FAIL;
9561 		goto theend;
9562 	    }
9563 	}
9564 	else
9565 	{
9566 	    /* Transfer short_fname to the main buffer (it's big enough),
9567 	     * unless get_short_pathname() did its work in-place. */
9568 	    *fname = *bufp = save_fname;
9569 	    if (short_fname != save_fname)
9570 		vim_strncpy(save_fname, short_fname, len);
9571 	    save_fname = NULL;
9572 	}
9573 
9574 	/* concat the not-shortened part of the path */
9575 	vim_strncpy(*fname + len, endp, sfx_len);
9576 	(*fname)[new_len] = NUL;
9577     }
9578 
9579 theend:
9580     vim_free(pbuf_unused);
9581     vim_free(save_fname);
9582 
9583     return retval;
9584 }
9585 
9586 /*
9587  * Get a pathname for a partial path.
9588  * Returns OK for success, FAIL for failure.
9589  */
9590     static int
9591 shortpath_for_partial(
9592     char_u	**fnamep,
9593     char_u	**bufp,
9594     int		*fnamelen)
9595 {
9596     int		sepcount, len, tflen;
9597     char_u	*p;
9598     char_u	*pbuf, *tfname;
9599     int		hasTilde;
9600 
9601     /* Count up the path separators from the RHS.. so we know which part
9602      * of the path to return. */
9603     sepcount = 0;
9604     for (p = *fnamep; p < *fnamep + *fnamelen; MB_PTR_ADV(p))
9605 	if (vim_ispathsep(*p))
9606 	    ++sepcount;
9607 
9608     /* Need full path first (use expand_env() to remove a "~/") */
9609     hasTilde = (**fnamep == '~');
9610     if (hasTilde)
9611 	pbuf = tfname = expand_env_save(*fnamep);
9612     else
9613 	pbuf = tfname = FullName_save(*fnamep, FALSE);
9614 
9615     len = tflen = (int)STRLEN(tfname);
9616 
9617     if (get_short_pathname(&tfname, &pbuf, &len) == FAIL)
9618 	return FAIL;
9619 
9620     if (len == 0)
9621     {
9622 	/* Don't have a valid filename, so shorten the rest of the
9623 	 * path if we can. This CAN give us invalid 8.3 filenames, but
9624 	 * there's not a lot of point in guessing what it might be.
9625 	 */
9626 	len = tflen;
9627 	if (shortpath_for_invalid_fname(&tfname, &pbuf, &len) == FAIL)
9628 	    return FAIL;
9629     }
9630 
9631     /* Count the paths backward to find the beginning of the desired string. */
9632     for (p = tfname + len - 1; p >= tfname; --p)
9633     {
9634 #ifdef FEAT_MBYTE
9635 	if (has_mbyte)
9636 	    p -= mb_head_off(tfname, p);
9637 #endif
9638 	if (vim_ispathsep(*p))
9639 	{
9640 	    if (sepcount == 0 || (hasTilde && sepcount == 1))
9641 		break;
9642 	    else
9643 		sepcount --;
9644 	}
9645     }
9646     if (hasTilde)
9647     {
9648 	--p;
9649 	if (p >= tfname)
9650 	    *p = '~';
9651 	else
9652 	    return FAIL;
9653     }
9654     else
9655 	++p;
9656 
9657     /* Copy in the string - p indexes into tfname - allocated at pbuf */
9658     vim_free(*bufp);
9659     *fnamelen = (int)STRLEN(p);
9660     *bufp = pbuf;
9661     *fnamep = p;
9662 
9663     return OK;
9664 }
9665 #endif /* WIN3264 */
9666 
9667 /*
9668  * Adjust a filename, according to a string of modifiers.
9669  * *fnamep must be NUL terminated when called.  When returning, the length is
9670  * determined by *fnamelen.
9671  * Returns VALID_ flags or -1 for failure.
9672  * When there is an error, *fnamep is set to NULL.
9673  */
9674     int
9675 modify_fname(
9676     char_u	*src,		// string with modifiers
9677     int		tilde_file,	// "~" is a file name, not $HOME
9678     int		*usedlen,	// characters after src that are used
9679     char_u	**fnamep,	// file name so far
9680     char_u	**bufp,		// buffer for allocated file name or NULL
9681     int		*fnamelen)	// length of fnamep
9682 {
9683     int		valid = 0;
9684     char_u	*tail;
9685     char_u	*s, *p, *pbuf;
9686     char_u	dirname[MAXPATHL];
9687     int		c;
9688     int		has_fullname = 0;
9689 #ifdef WIN3264
9690     char_u	*fname_start = *fnamep;
9691     int		has_shortname = 0;
9692 #endif
9693 
9694 repeat:
9695     /* ":p" - full path/file_name */
9696     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'p')
9697     {
9698 	has_fullname = 1;
9699 
9700 	valid |= VALID_PATH;
9701 	*usedlen += 2;
9702 
9703 	/* Expand "~/path" for all systems and "~user/path" for Unix and VMS */
9704 	if ((*fnamep)[0] == '~'
9705 #if !defined(UNIX) && !(defined(VMS) && defined(USER_HOME))
9706 		&& ((*fnamep)[1] == '/'
9707 # ifdef BACKSLASH_IN_FILENAME
9708 		    || (*fnamep)[1] == '\\'
9709 # endif
9710 		    || (*fnamep)[1] == NUL)
9711 #endif
9712 		&& !(tilde_file && (*fnamep)[1] == NUL)
9713 	   )
9714 	{
9715 	    *fnamep = expand_env_save(*fnamep);
9716 	    vim_free(*bufp);	/* free any allocated file name */
9717 	    *bufp = *fnamep;
9718 	    if (*fnamep == NULL)
9719 		return -1;
9720 	}
9721 
9722 	/* When "/." or "/.." is used: force expansion to get rid of it. */
9723 	for (p = *fnamep; *p != NUL; MB_PTR_ADV(p))
9724 	{
9725 	    if (vim_ispathsep(*p)
9726 		    && p[1] == '.'
9727 		    && (p[2] == NUL
9728 			|| vim_ispathsep(p[2])
9729 			|| (p[2] == '.'
9730 			    && (p[3] == NUL || vim_ispathsep(p[3])))))
9731 		break;
9732 	}
9733 
9734 	/* FullName_save() is slow, don't use it when not needed. */
9735 	if (*p != NUL || !vim_isAbsName(*fnamep))
9736 	{
9737 	    *fnamep = FullName_save(*fnamep, *p != NUL);
9738 	    vim_free(*bufp);	/* free any allocated file name */
9739 	    *bufp = *fnamep;
9740 	    if (*fnamep == NULL)
9741 		return -1;
9742 	}
9743 
9744 #ifdef WIN3264
9745 # if _WIN32_WINNT >= 0x0500
9746 	if (vim_strchr(*fnamep, '~') != NULL)
9747 	{
9748 	    /* Expand 8.3 filename to full path.  Needed to make sure the same
9749 	     * file does not have two different names.
9750 	     * Note: problem does not occur if _WIN32_WINNT < 0x0500. */
9751 	    p = alloc(_MAX_PATH + 1);
9752 	    if (p != NULL)
9753 	    {
9754 		if (GetLongPathName((LPSTR)*fnamep, (LPSTR)p, _MAX_PATH))
9755 		{
9756 		    vim_free(*bufp);
9757 		    *bufp = *fnamep = p;
9758 		}
9759 		else
9760 		    vim_free(p);
9761 	    }
9762 	}
9763 # endif
9764 #endif
9765 	/* Append a path separator to a directory. */
9766 	if (mch_isdir(*fnamep))
9767 	{
9768 	    /* Make room for one or two extra characters. */
9769 	    *fnamep = vim_strnsave(*fnamep, (int)STRLEN(*fnamep) + 2);
9770 	    vim_free(*bufp);	/* free any allocated file name */
9771 	    *bufp = *fnamep;
9772 	    if (*fnamep == NULL)
9773 		return -1;
9774 	    add_pathsep(*fnamep);
9775 	}
9776     }
9777 
9778     /* ":." - path relative to the current directory */
9779     /* ":~" - path relative to the home directory */
9780     /* ":8" - shortname path - postponed till after */
9781     while (src[*usedlen] == ':'
9782 		  && ((c = src[*usedlen + 1]) == '.' || c == '~' || c == '8'))
9783     {
9784 	*usedlen += 2;
9785 	if (c == '8')
9786 	{
9787 #ifdef WIN3264
9788 	    has_shortname = 1; /* Postpone this. */
9789 #endif
9790 	    continue;
9791 	}
9792 	pbuf = NULL;
9793 	/* Need full path first (use expand_env() to remove a "~/") */
9794 	if (!has_fullname)
9795 	{
9796 	    if (c == '.' && **fnamep == '~')
9797 		p = pbuf = expand_env_save(*fnamep);
9798 	    else
9799 		p = pbuf = FullName_save(*fnamep, FALSE);
9800 	}
9801 	else
9802 	    p = *fnamep;
9803 
9804 	has_fullname = 0;
9805 
9806 	if (p != NULL)
9807 	{
9808 	    if (c == '.')
9809 	    {
9810 		mch_dirname(dirname, MAXPATHL);
9811 		s = shorten_fname(p, dirname);
9812 		if (s != NULL)
9813 		{
9814 		    *fnamep = s;
9815 		    if (pbuf != NULL)
9816 		    {
9817 			vim_free(*bufp);   /* free any allocated file name */
9818 			*bufp = pbuf;
9819 			pbuf = NULL;
9820 		    }
9821 		}
9822 	    }
9823 	    else
9824 	    {
9825 		home_replace(NULL, p, dirname, MAXPATHL, TRUE);
9826 		/* Only replace it when it starts with '~' */
9827 		if (*dirname == '~')
9828 		{
9829 		    s = vim_strsave(dirname);
9830 		    if (s != NULL)
9831 		    {
9832 			*fnamep = s;
9833 			vim_free(*bufp);
9834 			*bufp = s;
9835 		    }
9836 		}
9837 	    }
9838 	    vim_free(pbuf);
9839 	}
9840     }
9841 
9842     tail = gettail(*fnamep);
9843     *fnamelen = (int)STRLEN(*fnamep);
9844 
9845     /* ":h" - head, remove "/file_name", can be repeated  */
9846     /* Don't remove the first "/" or "c:\" */
9847     while (src[*usedlen] == ':' && src[*usedlen + 1] == 'h')
9848     {
9849 	valid |= VALID_HEAD;
9850 	*usedlen += 2;
9851 	s = get_past_head(*fnamep);
9852 	while (tail > s && after_pathsep(s, tail))
9853 	    MB_PTR_BACK(*fnamep, tail);
9854 	*fnamelen = (int)(tail - *fnamep);
9855 #ifdef VMS
9856 	if (*fnamelen > 0)
9857 	    *fnamelen += 1; /* the path separator is part of the path */
9858 #endif
9859 	if (*fnamelen == 0)
9860 	{
9861 	    /* Result is empty.  Turn it into "." to make ":cd %:h" work. */
9862 	    p = vim_strsave((char_u *)".");
9863 	    if (p == NULL)
9864 		return -1;
9865 	    vim_free(*bufp);
9866 	    *bufp = *fnamep = tail = p;
9867 	    *fnamelen = 1;
9868 	}
9869 	else
9870 	{
9871 	    while (tail > s && !after_pathsep(s, tail))
9872 		MB_PTR_BACK(*fnamep, tail);
9873 	}
9874     }
9875 
9876     /* ":8" - shortname  */
9877     if (src[*usedlen] == ':' && src[*usedlen + 1] == '8')
9878     {
9879 	*usedlen += 2;
9880 #ifdef WIN3264
9881 	has_shortname = 1;
9882 #endif
9883     }
9884 
9885 #ifdef WIN3264
9886     /*
9887      * Handle ":8" after we have done 'heads' and before we do 'tails'.
9888      */
9889     if (has_shortname)
9890     {
9891 	/* Copy the string if it is shortened by :h and when it wasn't copied
9892 	 * yet, because we are going to change it in place.  Avoids changing
9893 	 * the buffer name for "%:8". */
9894 	if (*fnamelen < (int)STRLEN(*fnamep) || *fnamep == fname_start)
9895 	{
9896 	    p = vim_strnsave(*fnamep, *fnamelen);
9897 	    if (p == NULL)
9898 		return -1;
9899 	    vim_free(*bufp);
9900 	    *bufp = *fnamep = p;
9901 	}
9902 
9903 	/* Split into two implementations - makes it easier.  First is where
9904 	 * there isn't a full name already, second is where there is. */
9905 	if (!has_fullname && !vim_isAbsName(*fnamep))
9906 	{
9907 	    if (shortpath_for_partial(fnamep, bufp, fnamelen) == FAIL)
9908 		return -1;
9909 	}
9910 	else
9911 	{
9912 	    int		l = *fnamelen;
9913 
9914 	    /* Simple case, already have the full-name.
9915 	     * Nearly always shorter, so try first time. */
9916 	    if (get_short_pathname(fnamep, bufp, &l) == FAIL)
9917 		return -1;
9918 
9919 	    if (l == 0)
9920 	    {
9921 		/* Couldn't find the filename, search the paths. */
9922 		l = *fnamelen;
9923 		if (shortpath_for_invalid_fname(fnamep, bufp, &l) == FAIL)
9924 		    return -1;
9925 	    }
9926 	    *fnamelen = l;
9927 	}
9928     }
9929 #endif /* WIN3264 */
9930 
9931     /* ":t" - tail, just the basename */
9932     if (src[*usedlen] == ':' && src[*usedlen + 1] == 't')
9933     {
9934 	*usedlen += 2;
9935 	*fnamelen -= (int)(tail - *fnamep);
9936 	*fnamep = tail;
9937     }
9938 
9939     /* ":e" - extension, can be repeated */
9940     /* ":r" - root, without extension, can be repeated */
9941     while (src[*usedlen] == ':'
9942 	    && (src[*usedlen + 1] == 'e' || src[*usedlen + 1] == 'r'))
9943     {
9944 	/* find a '.' in the tail:
9945 	 * - for second :e: before the current fname
9946 	 * - otherwise: The last '.'
9947 	 */
9948 	if (src[*usedlen + 1] == 'e' && *fnamep > tail)
9949 	    s = *fnamep - 2;
9950 	else
9951 	    s = *fnamep + *fnamelen - 1;
9952 	for ( ; s > tail; --s)
9953 	    if (s[0] == '.')
9954 		break;
9955 	if (src[*usedlen + 1] == 'e')		/* :e */
9956 	{
9957 	    if (s > tail)
9958 	    {
9959 		*fnamelen += (int)(*fnamep - (s + 1));
9960 		*fnamep = s + 1;
9961 #ifdef VMS
9962 		/* cut version from the extension */
9963 		s = *fnamep + *fnamelen - 1;
9964 		for ( ; s > *fnamep; --s)
9965 		    if (s[0] == ';')
9966 			break;
9967 		if (s > *fnamep)
9968 		    *fnamelen = s - *fnamep;
9969 #endif
9970 	    }
9971 	    else if (*fnamep <= tail)
9972 		*fnamelen = 0;
9973 	}
9974 	else				/* :r */
9975 	{
9976 	    if (s > tail)	/* remove one extension */
9977 		*fnamelen = (int)(s - *fnamep);
9978 	}
9979 	*usedlen += 2;
9980     }
9981 
9982     /* ":s?pat?foo?" - substitute */
9983     /* ":gs?pat?foo?" - global substitute */
9984     if (src[*usedlen] == ':'
9985 	    && (src[*usedlen + 1] == 's'
9986 		|| (src[*usedlen + 1] == 'g' && src[*usedlen + 2] == 's')))
9987     {
9988 	char_u	    *str;
9989 	char_u	    *pat;
9990 	char_u	    *sub;
9991 	int	    sep;
9992 	char_u	    *flags;
9993 	int	    didit = FALSE;
9994 
9995 	flags = (char_u *)"";
9996 	s = src + *usedlen + 2;
9997 	if (src[*usedlen + 1] == 'g')
9998 	{
9999 	    flags = (char_u *)"g";
10000 	    ++s;
10001 	}
10002 
10003 	sep = *s++;
10004 	if (sep)
10005 	{
10006 	    /* find end of pattern */
10007 	    p = vim_strchr(s, sep);
10008 	    if (p != NULL)
10009 	    {
10010 		pat = vim_strnsave(s, (int)(p - s));
10011 		if (pat != NULL)
10012 		{
10013 		    s = p + 1;
10014 		    /* find end of substitution */
10015 		    p = vim_strchr(s, sep);
10016 		    if (p != NULL)
10017 		    {
10018 			sub = vim_strnsave(s, (int)(p - s));
10019 			str = vim_strnsave(*fnamep, *fnamelen);
10020 			if (sub != NULL && str != NULL)
10021 			{
10022 			    *usedlen = (int)(p + 1 - src);
10023 			    s = do_string_sub(str, pat, sub, NULL, flags);
10024 			    if (s != NULL)
10025 			    {
10026 				*fnamep = s;
10027 				*fnamelen = (int)STRLEN(s);
10028 				vim_free(*bufp);
10029 				*bufp = s;
10030 				didit = TRUE;
10031 			    }
10032 			}
10033 			vim_free(sub);
10034 			vim_free(str);
10035 		    }
10036 		    vim_free(pat);
10037 		}
10038 	    }
10039 	    /* after using ":s", repeat all the modifiers */
10040 	    if (didit)
10041 		goto repeat;
10042 	}
10043     }
10044 
10045     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'S')
10046     {
10047 	/* vim_strsave_shellescape() needs a NUL terminated string. */
10048 	c = (*fnamep)[*fnamelen];
10049 	if (c != NUL)
10050 	    (*fnamep)[*fnamelen] = NUL;
10051 	p = vim_strsave_shellescape(*fnamep, FALSE, FALSE);
10052 	if (c != NUL)
10053 	    (*fnamep)[*fnamelen] = c;
10054 	if (p == NULL)
10055 	    return -1;
10056 	vim_free(*bufp);
10057 	*bufp = *fnamep = p;
10058 	*fnamelen = (int)STRLEN(p);
10059 	*usedlen += 2;
10060     }
10061 
10062     return valid;
10063 }
10064 
10065 /*
10066  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
10067  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
10068  * "flags" can be "g" to do a global substitute.
10069  * Returns an allocated string, NULL for error.
10070  */
10071     char_u *
10072 do_string_sub(
10073     char_u	*str,
10074     char_u	*pat,
10075     char_u	*sub,
10076     typval_T	*expr,
10077     char_u	*flags)
10078 {
10079     int		sublen;
10080     regmatch_T	regmatch;
10081     int		i;
10082     int		do_all;
10083     char_u	*tail;
10084     char_u	*end;
10085     garray_T	ga;
10086     char_u	*ret;
10087     char_u	*save_cpo;
10088     char_u	*zero_width = NULL;
10089 
10090     /* Make 'cpoptions' empty, so that the 'l' flag doesn't work here */
10091     save_cpo = p_cpo;
10092     p_cpo = empty_option;
10093 
10094     ga_init2(&ga, 1, 200);
10095 
10096     do_all = (flags[0] == 'g');
10097 
10098     regmatch.rm_ic = p_ic;
10099     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
10100     if (regmatch.regprog != NULL)
10101     {
10102 	tail = str;
10103 	end = str + STRLEN(str);
10104 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
10105 	{
10106 	    /* Skip empty match except for first match. */
10107 	    if (regmatch.startp[0] == regmatch.endp[0])
10108 	    {
10109 		if (zero_width == regmatch.startp[0])
10110 		{
10111 		    /* avoid getting stuck on a match with an empty string */
10112 		    i = MB_PTR2LEN(tail);
10113 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
10114 								   (size_t)i);
10115 		    ga.ga_len += i;
10116 		    tail += i;
10117 		    continue;
10118 		}
10119 		zero_width = regmatch.startp[0];
10120 	    }
10121 
10122 	    /*
10123 	     * Get some space for a temporary buffer to do the substitution
10124 	     * into.  It will contain:
10125 	     * - The text up to where the match is.
10126 	     * - The substituted text.
10127 	     * - The text after the match.
10128 	     */
10129 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
10130 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
10131 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
10132 	    {
10133 		ga_clear(&ga);
10134 		break;
10135 	    }
10136 
10137 	    /* copy the text up to where the match is */
10138 	    i = (int)(regmatch.startp[0] - tail);
10139 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
10140 	    /* add the substituted text */
10141 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
10142 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
10143 	    ga.ga_len += i + sublen - 1;
10144 	    tail = regmatch.endp[0];
10145 	    if (*tail == NUL)
10146 		break;
10147 	    if (!do_all)
10148 		break;
10149 	}
10150 
10151 	if (ga.ga_data != NULL)
10152 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
10153 
10154 	vim_regfree(regmatch.regprog);
10155     }
10156 
10157     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
10158     ga_clear(&ga);
10159     if (p_cpo == empty_option)
10160 	p_cpo = save_cpo;
10161     else
10162 	/* Darn, evaluating {sub} expression or {expr} changed the value. */
10163 	free_string_option(save_cpo);
10164 
10165     return ret;
10166 }
10167 
10168     static int
10169 filter_map_one(typval_T *tv, typval_T *expr, int map, int *remp)
10170 {
10171     typval_T	rettv;
10172     typval_T	argv[3];
10173     int		retval = FAIL;
10174 
10175     copy_tv(tv, &vimvars[VV_VAL].vv_tv);
10176     argv[0] = vimvars[VV_KEY].vv_tv;
10177     argv[1] = vimvars[VV_VAL].vv_tv;
10178     if (eval_expr_typval(expr, argv, 2, &rettv) == FAIL)
10179 	goto theend;
10180     if (map)
10181     {
10182 	/* map(): replace the list item value */
10183 	clear_tv(tv);
10184 	rettv.v_lock = 0;
10185 	*tv = rettv;
10186     }
10187     else
10188     {
10189 	int	    error = FALSE;
10190 
10191 	/* filter(): when expr is zero remove the item */
10192 	*remp = (get_tv_number_chk(&rettv, &error) == 0);
10193 	clear_tv(&rettv);
10194 	/* On type error, nothing has been removed; return FAIL to stop the
10195 	 * loop.  The error message was given by get_tv_number_chk(). */
10196 	if (error)
10197 	    goto theend;
10198     }
10199     retval = OK;
10200 theend:
10201     clear_tv(&vimvars[VV_VAL].vv_tv);
10202     return retval;
10203 }
10204 
10205 
10206 /*
10207  * Implementation of map() and filter().
10208  */
10209     void
10210 filter_map(typval_T *argvars, typval_T *rettv, int map)
10211 {
10212     typval_T	*expr;
10213     listitem_T	*li, *nli;
10214     list_T	*l = NULL;
10215     dictitem_T	*di;
10216     hashtab_T	*ht;
10217     hashitem_T	*hi;
10218     dict_T	*d = NULL;
10219     typval_T	save_val;
10220     typval_T	save_key;
10221     int		rem;
10222     int		todo;
10223     char_u	*ermsg = (char_u *)(map ? "map()" : "filter()");
10224     char_u	*arg_errmsg = (char_u *)(map ? N_("map() argument")
10225 				   : N_("filter() argument"));
10226     int		save_did_emsg;
10227     int		idx = 0;
10228 
10229     if (argvars[0].v_type == VAR_LIST)
10230     {
10231 	if ((l = argvars[0].vval.v_list) == NULL
10232 	      || (!map && tv_check_lock(l->lv_lock, arg_errmsg, TRUE)))
10233 	    return;
10234     }
10235     else if (argvars[0].v_type == VAR_DICT)
10236     {
10237 	if ((d = argvars[0].vval.v_dict) == NULL
10238 	      || (!map && tv_check_lock(d->dv_lock, arg_errmsg, TRUE)))
10239 	    return;
10240     }
10241     else
10242     {
10243 	EMSG2(_(e_listdictarg), ermsg);
10244 	return;
10245     }
10246 
10247     expr = &argvars[1];
10248     /* On type errors, the preceding call has already displayed an error
10249      * message.  Avoid a misleading error message for an empty string that
10250      * was not passed as argument. */
10251     if (expr->v_type != VAR_UNKNOWN)
10252     {
10253 	prepare_vimvar(VV_VAL, &save_val);
10254 
10255 	/* We reset "did_emsg" to be able to detect whether an error
10256 	 * occurred during evaluation of the expression. */
10257 	save_did_emsg = did_emsg;
10258 	did_emsg = FALSE;
10259 
10260 	prepare_vimvar(VV_KEY, &save_key);
10261 	if (argvars[0].v_type == VAR_DICT)
10262 	{
10263 	    vimvars[VV_KEY].vv_type = VAR_STRING;
10264 
10265 	    ht = &d->dv_hashtab;
10266 	    hash_lock(ht);
10267 	    todo = (int)ht->ht_used;
10268 	    for (hi = ht->ht_array; todo > 0; ++hi)
10269 	    {
10270 		if (!HASHITEM_EMPTY(hi))
10271 		{
10272 		    int r;
10273 
10274 		    --todo;
10275 		    di = HI2DI(hi);
10276 		    if (map &&
10277 			    (tv_check_lock(di->di_tv.v_lock, arg_errmsg, TRUE)
10278 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE)))
10279 			break;
10280 		    vimvars[VV_KEY].vv_str = vim_strsave(di->di_key);
10281 		    r = filter_map_one(&di->di_tv, expr, map, &rem);
10282 		    clear_tv(&vimvars[VV_KEY].vv_tv);
10283 		    if (r == FAIL || did_emsg)
10284 			break;
10285 		    if (!map && rem)
10286 		    {
10287 			if (var_check_fixed(di->di_flags, arg_errmsg, TRUE)
10288 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE))
10289 			    break;
10290 			dictitem_remove(d, di);
10291 		    }
10292 		}
10293 	    }
10294 	    hash_unlock(ht);
10295 	}
10296 	else
10297 	{
10298 	    vimvars[VV_KEY].vv_type = VAR_NUMBER;
10299 
10300 	    for (li = l->lv_first; li != NULL; li = nli)
10301 	    {
10302 		if (map && tv_check_lock(li->li_tv.v_lock, arg_errmsg, TRUE))
10303 		    break;
10304 		nli = li->li_next;
10305 		vimvars[VV_KEY].vv_nr = idx;
10306 		if (filter_map_one(&li->li_tv, expr, map, &rem) == FAIL
10307 								  || did_emsg)
10308 		    break;
10309 		if (!map && rem)
10310 		    listitem_remove(l, li);
10311 		++idx;
10312 	    }
10313 	}
10314 
10315 	restore_vimvar(VV_KEY, &save_key);
10316 	restore_vimvar(VV_VAL, &save_val);
10317 
10318 	did_emsg |= save_did_emsg;
10319     }
10320 
10321     copy_tv(&argvars[0], rettv);
10322 }
10323 
10324 #endif /* defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) */
10325