xref: /vim-8.2.3635/src/eval.c (revision bc2eada5)
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 };
191 
192 /* shorthand */
193 #define vv_type		vv_di.di_tv.v_type
194 #define vv_nr		vv_di.di_tv.vval.v_number
195 #define vv_float	vv_di.di_tv.vval.v_float
196 #define vv_str		vv_di.di_tv.vval.v_string
197 #define vv_list		vv_di.di_tv.vval.v_list
198 #define vv_dict		vv_di.di_tv.vval.v_dict
199 #define vv_tv		vv_di.di_tv
200 
201 static dictitem_T	vimvars_var;		/* variable used for v: */
202 #define vimvarht  vimvardict.dv_hashtab
203 
204 static int ex_let_vars(char_u *arg, typval_T *tv, int copy, int semicolon, int var_count, char_u *nextchars);
205 static char_u *skip_var_list(char_u *arg, int *var_count, int *semicolon);
206 static char_u *skip_var_one(char_u *arg);
207 static void list_glob_vars(int *first);
208 static void list_buf_vars(int *first);
209 static void list_win_vars(int *first);
210 #ifdef FEAT_WINDOWS
211 static void list_tab_vars(int *first);
212 #endif
213 static void list_vim_vars(int *first);
214 static void list_script_vars(int *first);
215 static char_u *list_arg_vars(exarg_T *eap, char_u *arg, int *first);
216 static char_u *ex_let_one(char_u *arg, typval_T *tv, int copy, char_u *endchars, char_u *op);
217 static void set_var_lval(lval_T *lp, char_u *endp, typval_T *rettv, int copy, char_u *op);
218 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
219 static void ex_unletlock(exarg_T *eap, char_u *argstart, int deep);
220 static int do_unlet_var(lval_T *lp, char_u *name_end, int forceit);
221 static int do_lock_var(lval_T *lp, char_u *name_end, int deep, int lock);
222 static void item_lock(typval_T *tv, int deep, int lock);
223 
224 static int eval2(char_u **arg, typval_T *rettv, int evaluate);
225 static int eval3(char_u **arg, typval_T *rettv, int evaluate);
226 static int eval4(char_u **arg, typval_T *rettv, int evaluate);
227 static int eval5(char_u **arg, typval_T *rettv, int evaluate);
228 static int eval6(char_u **arg, typval_T *rettv, int evaluate, int want_string);
229 static int eval7(char_u **arg, typval_T *rettv, int evaluate, int want_string);
230 
231 static int eval_index(char_u **arg, typval_T *rettv, int evaluate, int verbose);
232 static int get_string_tv(char_u **arg, typval_T *rettv, int evaluate);
233 static int get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate);
234 static int free_unref_items(int copyID);
235 static int get_env_tv(char_u **arg, typval_T *rettv, int evaluate);
236 static int get_env_len(char_u **arg);
237 static char_u * make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
238 static void check_vars(char_u *name, int len);
239 static typval_T *alloc_string_tv(char_u *string);
240 static void delete_var(hashtab_T *ht, hashitem_T *hi);
241 static void list_one_var(dictitem_T *v, char_u *prefix, int *first);
242 static void list_one_var_a(char_u *prefix, char_u *name, int type, char_u *string, int *first);
243 static char_u *find_option_end(char_u **arg, int *opt_flags);
244 
245 #ifdef EBCDIC
246 static int compare_func_name(const void *s1, const void *s2);
247 static void sortFunctions();
248 #endif
249 
250 /* for VIM_VERSION_ defines */
251 #include "version.h"
252 
253 /*
254  * Initialize the global and v: variables.
255  */
256     void
257 eval_init(void)
258 {
259     int		    i;
260     struct vimvar   *p;
261 
262     init_var_dict(&globvardict, &globvars_var, VAR_DEF_SCOPE);
263     init_var_dict(&vimvardict, &vimvars_var, VAR_SCOPE);
264     vimvardict.dv_lock = VAR_FIXED;
265     hash_init(&compat_hashtab);
266     func_init();
267 
268     for (i = 0; i < VV_LEN; ++i)
269     {
270 	p = &vimvars[i];
271 	if (STRLEN(p->vv_name) > 16)
272 	{
273 	    EMSG("INTERNAL: name too long, increase size of dictitem16_T");
274 	    getout(1);
275 	}
276 	STRCPY(p->vv_di.di_key, p->vv_name);
277 	if (p->vv_flags & VV_RO)
278 	    p->vv_di.di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
279 	else if (p->vv_flags & VV_RO_SBX)
280 	    p->vv_di.di_flags = DI_FLAGS_RO_SBX | DI_FLAGS_FIX;
281 	else
282 	    p->vv_di.di_flags = DI_FLAGS_FIX;
283 
284 	/* add to v: scope dict, unless the value is not always available */
285 	if (p->vv_type != VAR_UNKNOWN)
286 	    hash_add(&vimvarht, p->vv_di.di_key);
287 	if (p->vv_flags & VV_COMPAT)
288 	    /* add to compat scope dict */
289 	    hash_add(&compat_hashtab, p->vv_di.di_key);
290     }
291     vimvars[VV_VERSION].vv_nr = VIM_VERSION_100;
292 
293     set_vim_var_nr(VV_SEARCHFORWARD, 1L);
294     set_vim_var_nr(VV_HLSEARCH, 1L);
295     set_vim_var_dict(VV_COMPLETED_ITEM, dict_alloc());
296     set_vim_var_list(VV_ERRORS, list_alloc());
297 
298     set_vim_var_nr(VV_FALSE, VVAL_FALSE);
299     set_vim_var_nr(VV_TRUE, VVAL_TRUE);
300     set_vim_var_nr(VV_NONE, VVAL_NONE);
301     set_vim_var_nr(VV_NULL, VVAL_NULL);
302 
303     set_vim_var_nr(VV_TYPE_NUMBER,  VAR_TYPE_NUMBER);
304     set_vim_var_nr(VV_TYPE_STRING,  VAR_TYPE_STRING);
305     set_vim_var_nr(VV_TYPE_FUNC,    VAR_TYPE_FUNC);
306     set_vim_var_nr(VV_TYPE_LIST,    VAR_TYPE_LIST);
307     set_vim_var_nr(VV_TYPE_DICT,    VAR_TYPE_DICT);
308     set_vim_var_nr(VV_TYPE_FLOAT,   VAR_TYPE_FLOAT);
309     set_vim_var_nr(VV_TYPE_BOOL,    VAR_TYPE_BOOL);
310     set_vim_var_nr(VV_TYPE_NONE,    VAR_TYPE_NONE);
311     set_vim_var_nr(VV_TYPE_JOB,     VAR_TYPE_JOB);
312     set_vim_var_nr(VV_TYPE_CHANNEL, VAR_TYPE_CHANNEL);
313 
314     set_reg_var(0);  /* default for v:register is not 0 but '"' */
315 
316 #ifdef EBCDIC
317     /*
318      * Sort the function table, to enable binary search.
319      */
320     sortFunctions();
321 #endif
322 }
323 
324 #if defined(EXITFREE) || defined(PROTO)
325     void
326 eval_clear(void)
327 {
328     int		    i;
329     struct vimvar   *p;
330 
331     for (i = 0; i < VV_LEN; ++i)
332     {
333 	p = &vimvars[i];
334 	if (p->vv_di.di_tv.v_type == VAR_STRING)
335 	{
336 	    vim_free(p->vv_str);
337 	    p->vv_str = NULL;
338 	}
339 	else if (p->vv_di.di_tv.v_type == VAR_LIST)
340 	{
341 	    list_unref(p->vv_list);
342 	    p->vv_list = NULL;
343 	}
344     }
345     hash_clear(&vimvarht);
346     hash_init(&vimvarht);  /* garbage_collect() will access it */
347     hash_clear(&compat_hashtab);
348 
349     free_scriptnames();
350 # if defined(FEAT_CMDL_COMPL)
351     free_locales();
352 # endif
353 
354     /* global variables */
355     vars_clear(&globvarht);
356 
357     /* autoloaded script names */
358     ga_clear_strings(&ga_loaded);
359 
360     /* Script-local variables. First clear all the variables and in a second
361      * loop free the scriptvar_T, because a variable in one script might hold
362      * a reference to the whole scope of another script. */
363     for (i = 1; i <= ga_scripts.ga_len; ++i)
364 	vars_clear(&SCRIPT_VARS(i));
365     for (i = 1; i <= ga_scripts.ga_len; ++i)
366 	vim_free(SCRIPT_SV(i));
367     ga_clear(&ga_scripts);
368 
369     /* unreferenced lists and dicts */
370     (void)garbage_collect(FALSE);
371 
372     /* functions */
373     free_all_functions();
374 }
375 #endif
376 
377 
378 /*
379  * Set an internal variable to a string value. Creates the variable if it does
380  * not already exist.
381  */
382     void
383 set_internal_string_var(char_u *name, char_u *value)
384 {
385     char_u	*val;
386     typval_T	*tvp;
387 
388     val = vim_strsave(value);
389     if (val != NULL)
390     {
391 	tvp = alloc_string_tv(val);
392 	if (tvp != NULL)
393 	{
394 	    set_var(name, tvp, FALSE);
395 	    free_tv(tvp);
396 	}
397     }
398 }
399 
400 static lval_T	*redir_lval = NULL;
401 #define EVALCMD_BUSY (redir_lval == (lval_T *)&redir_lval)
402 static garray_T redir_ga;	/* only valid when redir_lval is not NULL */
403 static char_u	*redir_endp = NULL;
404 static char_u	*redir_varname = NULL;
405 
406 /*
407  * Start recording command output to a variable
408  * When "append" is TRUE append to an existing variable.
409  * Returns OK if successfully completed the setup.  FAIL otherwise.
410  */
411     int
412 var_redir_start(char_u *name, int append)
413 {
414     int		save_emsg;
415     int		err;
416     typval_T	tv;
417 
418     /* Catch a bad name early. */
419     if (!eval_isnamec1(*name))
420     {
421 	EMSG(_(e_invarg));
422 	return FAIL;
423     }
424 
425     /* Make a copy of the name, it is used in redir_lval until redir ends. */
426     redir_varname = vim_strsave(name);
427     if (redir_varname == NULL)
428 	return FAIL;
429 
430     redir_lval = (lval_T *)alloc_clear((unsigned)sizeof(lval_T));
431     if (redir_lval == NULL)
432     {
433 	var_redir_stop();
434 	return FAIL;
435     }
436 
437     /* The output is stored in growarray "redir_ga" until redirection ends. */
438     ga_init2(&redir_ga, (int)sizeof(char), 500);
439 
440     /* Parse the variable name (can be a dict or list entry). */
441     redir_endp = get_lval(redir_varname, NULL, redir_lval, FALSE, FALSE, 0,
442 							     FNE_CHECK_START);
443     if (redir_endp == NULL || redir_lval->ll_name == NULL || *redir_endp != NUL)
444     {
445 	clear_lval(redir_lval);
446 	if (redir_endp != NULL && *redir_endp != NUL)
447 	    /* Trailing characters are present after the variable name */
448 	    EMSG(_(e_trailing));
449 	else
450 	    EMSG(_(e_invarg));
451 	redir_endp = NULL;  /* don't store a value, only cleanup */
452 	var_redir_stop();
453 	return FAIL;
454     }
455 
456     /* check if we can write to the variable: set it to or append an empty
457      * string */
458     save_emsg = did_emsg;
459     did_emsg = FALSE;
460     tv.v_type = VAR_STRING;
461     tv.vval.v_string = (char_u *)"";
462     if (append)
463 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, (char_u *)".");
464     else
465 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, (char_u *)"=");
466     clear_lval(redir_lval);
467     err = did_emsg;
468     did_emsg |= save_emsg;
469     if (err)
470     {
471 	redir_endp = NULL;  /* don't store a value, only cleanup */
472 	var_redir_stop();
473 	return FAIL;
474     }
475 
476     return OK;
477 }
478 
479 /*
480  * Append "value[value_len]" to the variable set by var_redir_start().
481  * The actual appending is postponed until redirection ends, because the value
482  * appended may in fact be the string we write to, changing it may cause freed
483  * memory to be used:
484  *   :redir => foo
485  *   :let foo
486  *   :redir END
487  */
488     void
489 var_redir_str(char_u *value, int value_len)
490 {
491     int		len;
492 
493     if (redir_lval == NULL)
494 	return;
495 
496     if (value_len == -1)
497 	len = (int)STRLEN(value);	/* Append the entire string */
498     else
499 	len = value_len;		/* Append only "value_len" characters */
500 
501     if (ga_grow(&redir_ga, len) == OK)
502     {
503 	mch_memmove((char *)redir_ga.ga_data + redir_ga.ga_len, value, len);
504 	redir_ga.ga_len += len;
505     }
506     else
507 	var_redir_stop();
508 }
509 
510 /*
511  * Stop redirecting command output to a variable.
512  * Frees the allocated memory.
513  */
514     void
515 var_redir_stop(void)
516 {
517     typval_T	tv;
518 
519     if (EVALCMD_BUSY)
520     {
521 	redir_lval = NULL;
522 	return;
523     }
524 
525     if (redir_lval != NULL)
526     {
527 	/* If there was no error: assign the text to the variable. */
528 	if (redir_endp != NULL)
529 	{
530 	    ga_append(&redir_ga, NUL);  /* Append the trailing NUL. */
531 	    tv.v_type = VAR_STRING;
532 	    tv.vval.v_string = redir_ga.ga_data;
533 	    /* Call get_lval() again, if it's inside a Dict or List it may
534 	     * have changed. */
535 	    redir_endp = get_lval(redir_varname, NULL, redir_lval,
536 					FALSE, FALSE, 0, FNE_CHECK_START);
537 	    if (redir_endp != NULL && redir_lval->ll_name != NULL)
538 		set_var_lval(redir_lval, redir_endp, &tv, FALSE, (char_u *)".");
539 	    clear_lval(redir_lval);
540 	}
541 
542 	/* free the collected output */
543 	vim_free(redir_ga.ga_data);
544 	redir_ga.ga_data = NULL;
545 
546 	vim_free(redir_lval);
547 	redir_lval = NULL;
548     }
549     vim_free(redir_varname);
550     redir_varname = NULL;
551 }
552 
553 # if defined(FEAT_MBYTE) || defined(PROTO)
554     int
555 eval_charconvert(
556     char_u	*enc_from,
557     char_u	*enc_to,
558     char_u	*fname_from,
559     char_u	*fname_to)
560 {
561     int		err = FALSE;
562 
563     set_vim_var_string(VV_CC_FROM, enc_from, -1);
564     set_vim_var_string(VV_CC_TO, enc_to, -1);
565     set_vim_var_string(VV_FNAME_IN, fname_from, -1);
566     set_vim_var_string(VV_FNAME_OUT, fname_to, -1);
567     if (eval_to_bool(p_ccv, &err, NULL, FALSE))
568 	err = TRUE;
569     set_vim_var_string(VV_CC_FROM, NULL, -1);
570     set_vim_var_string(VV_CC_TO, NULL, -1);
571     set_vim_var_string(VV_FNAME_IN, NULL, -1);
572     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
573 
574     if (err)
575 	return FAIL;
576     return OK;
577 }
578 # endif
579 
580 # if defined(FEAT_POSTSCRIPT) || defined(PROTO)
581     int
582 eval_printexpr(char_u *fname, char_u *args)
583 {
584     int		err = FALSE;
585 
586     set_vim_var_string(VV_FNAME_IN, fname, -1);
587     set_vim_var_string(VV_CMDARG, args, -1);
588     if (eval_to_bool(p_pexpr, &err, NULL, FALSE))
589 	err = TRUE;
590     set_vim_var_string(VV_FNAME_IN, NULL, -1);
591     set_vim_var_string(VV_CMDARG, NULL, -1);
592 
593     if (err)
594     {
595 	mch_remove(fname);
596 	return FAIL;
597     }
598     return OK;
599 }
600 # endif
601 
602 # if defined(FEAT_DIFF) || defined(PROTO)
603     void
604 eval_diff(
605     char_u	*origfile,
606     char_u	*newfile,
607     char_u	*outfile)
608 {
609     int		err = FALSE;
610 
611     set_vim_var_string(VV_FNAME_IN, origfile, -1);
612     set_vim_var_string(VV_FNAME_NEW, newfile, -1);
613     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
614     (void)eval_to_bool(p_dex, &err, NULL, FALSE);
615     set_vim_var_string(VV_FNAME_IN, NULL, -1);
616     set_vim_var_string(VV_FNAME_NEW, NULL, -1);
617     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
618 }
619 
620     void
621 eval_patch(
622     char_u	*origfile,
623     char_u	*difffile,
624     char_u	*outfile)
625 {
626     int		err;
627 
628     set_vim_var_string(VV_FNAME_IN, origfile, -1);
629     set_vim_var_string(VV_FNAME_DIFF, difffile, -1);
630     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
631     (void)eval_to_bool(p_pex, &err, NULL, FALSE);
632     set_vim_var_string(VV_FNAME_IN, NULL, -1);
633     set_vim_var_string(VV_FNAME_DIFF, NULL, -1);
634     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
635 }
636 # endif
637 
638 /*
639  * Top level evaluation function, returning a boolean.
640  * Sets "error" to TRUE if there was an error.
641  * Return TRUE or FALSE.
642  */
643     int
644 eval_to_bool(
645     char_u	*arg,
646     int		*error,
647     char_u	**nextcmd,
648     int		skip)	    /* only parse, don't execute */
649 {
650     typval_T	tv;
651     varnumber_T	retval = FALSE;
652 
653     if (skip)
654 	++emsg_skip;
655     if (eval0(arg, &tv, nextcmd, !skip) == FAIL)
656 	*error = TRUE;
657     else
658     {
659 	*error = FALSE;
660 	if (!skip)
661 	{
662 	    retval = (get_tv_number_chk(&tv, error) != 0);
663 	    clear_tv(&tv);
664 	}
665     }
666     if (skip)
667 	--emsg_skip;
668 
669     return (int)retval;
670 }
671 
672 /*
673  * Top level evaluation function, returning a string.  If "skip" is TRUE,
674  * only parsing to "nextcmd" is done, without reporting errors.  Return
675  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
676  */
677     char_u *
678 eval_to_string_skip(
679     char_u	*arg,
680     char_u	**nextcmd,
681     int		skip)	    /* only parse, don't execute */
682 {
683     typval_T	tv;
684     char_u	*retval;
685 
686     if (skip)
687 	++emsg_skip;
688     if (eval0(arg, &tv, nextcmd, !skip) == FAIL || skip)
689 	retval = NULL;
690     else
691     {
692 	retval = vim_strsave(get_tv_string(&tv));
693 	clear_tv(&tv);
694     }
695     if (skip)
696 	--emsg_skip;
697 
698     return retval;
699 }
700 
701 /*
702  * Skip over an expression at "*pp".
703  * Return FAIL for an error, OK otherwise.
704  */
705     int
706 skip_expr(char_u **pp)
707 {
708     typval_T	rettv;
709 
710     *pp = skipwhite(*pp);
711     return eval1(pp, &rettv, FALSE);
712 }
713 
714 /*
715  * Top level evaluation function, returning a string.
716  * When "convert" is TRUE convert a List into a sequence of lines and convert
717  * a Float to a String.
718  * Return pointer to allocated memory, or NULL for failure.
719  */
720     char_u *
721 eval_to_string(
722     char_u	*arg,
723     char_u	**nextcmd,
724     int		convert)
725 {
726     typval_T	tv;
727     char_u	*retval;
728     garray_T	ga;
729 #ifdef FEAT_FLOAT
730     char_u	numbuf[NUMBUFLEN];
731 #endif
732 
733     if (eval0(arg, &tv, nextcmd, TRUE) == FAIL)
734 	retval = NULL;
735     else
736     {
737 	if (convert && tv.v_type == VAR_LIST)
738 	{
739 	    ga_init2(&ga, (int)sizeof(char), 80);
740 	    if (tv.vval.v_list != NULL)
741 	    {
742 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
743 		if (tv.vval.v_list->lv_len > 0)
744 		    ga_append(&ga, NL);
745 	    }
746 	    ga_append(&ga, NUL);
747 	    retval = (char_u *)ga.ga_data;
748 	}
749 #ifdef FEAT_FLOAT
750 	else if (convert && tv.v_type == VAR_FLOAT)
751 	{
752 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
753 	    retval = vim_strsave(numbuf);
754 	}
755 #endif
756 	else
757 	    retval = vim_strsave(get_tv_string(&tv));
758 	clear_tv(&tv);
759     }
760 
761     return retval;
762 }
763 
764 /*
765  * Call eval_to_string() without using current local variables and using
766  * textlock.  When "use_sandbox" is TRUE use the sandbox.
767  */
768     char_u *
769 eval_to_string_safe(
770     char_u	*arg,
771     char_u	**nextcmd,
772     int		use_sandbox)
773 {
774     char_u	*retval;
775     void	*save_funccalp;
776 
777     save_funccalp = save_funccal();
778     if (use_sandbox)
779 	++sandbox;
780     ++textlock;
781     retval = eval_to_string(arg, nextcmd, FALSE);
782     if (use_sandbox)
783 	--sandbox;
784     --textlock;
785     restore_funccal(save_funccalp);
786     return retval;
787 }
788 
789 /*
790  * Top level evaluation function, returning a number.
791  * Evaluates "expr" silently.
792  * Returns -1 for an error.
793  */
794     varnumber_T
795 eval_to_number(char_u *expr)
796 {
797     typval_T	rettv;
798     varnumber_T	retval;
799     char_u	*p = skipwhite(expr);
800 
801     ++emsg_off;
802 
803     if (eval1(&p, &rettv, TRUE) == FAIL)
804 	retval = -1;
805     else
806     {
807 	retval = get_tv_number_chk(&rettv, NULL);
808 	clear_tv(&rettv);
809     }
810     --emsg_off;
811 
812     return retval;
813 }
814 
815 /*
816  * Prepare v: variable "idx" to be used.
817  * Save the current typeval in "save_tv".
818  * When not used yet add the variable to the v: hashtable.
819  */
820     static void
821 prepare_vimvar(int idx, typval_T *save_tv)
822 {
823     *save_tv = vimvars[idx].vv_tv;
824     if (vimvars[idx].vv_type == VAR_UNKNOWN)
825 	hash_add(&vimvarht, vimvars[idx].vv_di.di_key);
826 }
827 
828 /*
829  * Restore v: variable "idx" to typeval "save_tv".
830  * When no longer defined, remove the variable from the v: hashtable.
831  */
832     static void
833 restore_vimvar(int idx, typval_T *save_tv)
834 {
835     hashitem_T	*hi;
836 
837     vimvars[idx].vv_tv = *save_tv;
838     if (vimvars[idx].vv_type == VAR_UNKNOWN)
839     {
840 	hi = hash_find(&vimvarht, vimvars[idx].vv_di.di_key);
841 	if (HASHITEM_EMPTY(hi))
842 	    internal_error("restore_vimvar()");
843 	else
844 	    hash_remove(&vimvarht, hi);
845     }
846 }
847 
848 #if defined(FEAT_SPELL) || defined(PROTO)
849 /*
850  * Evaluate an expression to a list with suggestions.
851  * For the "expr:" part of 'spellsuggest'.
852  * Returns NULL when there is an error.
853  */
854     list_T *
855 eval_spell_expr(char_u *badword, char_u *expr)
856 {
857     typval_T	save_val;
858     typval_T	rettv;
859     list_T	*list = NULL;
860     char_u	*p = skipwhite(expr);
861 
862     /* Set "v:val" to the bad word. */
863     prepare_vimvar(VV_VAL, &save_val);
864     vimvars[VV_VAL].vv_type = VAR_STRING;
865     vimvars[VV_VAL].vv_str = badword;
866     if (p_verbose == 0)
867 	++emsg_off;
868 
869     if (eval1(&p, &rettv, TRUE) == OK)
870     {
871 	if (rettv.v_type != VAR_LIST)
872 	    clear_tv(&rettv);
873 	else
874 	    list = rettv.vval.v_list;
875     }
876 
877     if (p_verbose == 0)
878 	--emsg_off;
879     restore_vimvar(VV_VAL, &save_val);
880 
881     return list;
882 }
883 
884 /*
885  * "list" is supposed to contain two items: a word and a number.  Return the
886  * word in "pp" and the number as the return value.
887  * Return -1 if anything isn't right.
888  * Used to get the good word and score from the eval_spell_expr() result.
889  */
890     int
891 get_spellword(list_T *list, char_u **pp)
892 {
893     listitem_T	*li;
894 
895     li = list->lv_first;
896     if (li == NULL)
897 	return -1;
898     *pp = get_tv_string(&li->li_tv);
899 
900     li = li->li_next;
901     if (li == NULL)
902 	return -1;
903     return (int)get_tv_number(&li->li_tv);
904 }
905 #endif
906 
907 /*
908  * Top level evaluation function.
909  * Returns an allocated typval_T with the result.
910  * Returns NULL when there is an error.
911  */
912     typval_T *
913 eval_expr(char_u *arg, char_u **nextcmd)
914 {
915     typval_T	*tv;
916 
917     tv = (typval_T *)alloc(sizeof(typval_T));
918     if (tv != NULL && eval0(arg, tv, nextcmd, TRUE) == FAIL)
919     {
920 	vim_free(tv);
921 	tv = NULL;
922     }
923 
924     return tv;
925 }
926 
927 
928 /*
929  * Call some vimL function and return the result in "*rettv".
930  * Uses argv[argc] for the function arguments.  Only Number and String
931  * arguments are currently supported.
932  * Returns OK or FAIL.
933  */
934     int
935 call_vim_function(
936     char_u      *func,
937     int		argc,
938     char_u      **argv,
939     int		safe,		/* use the sandbox */
940     int		str_arg_only,	/* all arguments are strings */
941     typval_T	*rettv)
942 {
943     typval_T	*argvars;
944     varnumber_T	n;
945     int		len;
946     int		i;
947     int		doesrange;
948     void	*save_funccalp = NULL;
949     int		ret;
950 
951     argvars = (typval_T *)alloc((unsigned)((argc + 1) * sizeof(typval_T)));
952     if (argvars == NULL)
953 	return FAIL;
954 
955     for (i = 0; i < argc; i++)
956     {
957 	/* Pass a NULL or empty argument as an empty string */
958 	if (argv[i] == NULL || *argv[i] == NUL)
959 	{
960 	    argvars[i].v_type = VAR_STRING;
961 	    argvars[i].vval.v_string = (char_u *)"";
962 	    continue;
963 	}
964 
965 	if (str_arg_only)
966 	    len = 0;
967 	else
968 	    /* Recognize a number argument, the others must be strings. */
969 	    vim_str2nr(argv[i], NULL, &len, STR2NR_ALL, &n, NULL, 0);
970 	if (len != 0 && len == (int)STRLEN(argv[i]))
971 	{
972 	    argvars[i].v_type = VAR_NUMBER;
973 	    argvars[i].vval.v_number = n;
974 	}
975 	else
976 	{
977 	    argvars[i].v_type = VAR_STRING;
978 	    argvars[i].vval.v_string = argv[i];
979 	}
980     }
981 
982     if (safe)
983     {
984 	save_funccalp = save_funccal();
985 	++sandbox;
986     }
987 
988     rettv->v_type = VAR_UNKNOWN;		/* clear_tv() uses this */
989     ret = call_func(func, (int)STRLEN(func), rettv, argc, argvars, NULL,
990 		    curwin->w_cursor.lnum, curwin->w_cursor.lnum,
991 		    &doesrange, TRUE, NULL, NULL);
992     if (safe)
993     {
994 	--sandbox;
995 	restore_funccal(save_funccalp);
996     }
997     vim_free(argvars);
998 
999     if (ret == FAIL)
1000 	clear_tv(rettv);
1001 
1002     return ret;
1003 }
1004 
1005 /*
1006  * Call vimL function "func" and return the result as a number.
1007  * Returns -1 when calling the function fails.
1008  * Uses argv[argc] for the function arguments.
1009  */
1010     varnumber_T
1011 call_func_retnr(
1012     char_u      *func,
1013     int		argc,
1014     char_u      **argv,
1015     int		safe)		/* use the sandbox */
1016 {
1017     typval_T	rettv;
1018     varnumber_T	retval;
1019 
1020     /* All arguments are passed as strings, no conversion to number. */
1021     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
1022 	return -1;
1023 
1024     retval = get_tv_number_chk(&rettv, NULL);
1025     clear_tv(&rettv);
1026     return retval;
1027 }
1028 
1029 #if (defined(FEAT_USR_CMDS) && defined(FEAT_CMDL_COMPL)) \
1030 	|| defined(FEAT_COMPL_FUNC) || defined(PROTO)
1031 
1032 # if (defined(FEAT_USR_CMDS) && defined(FEAT_CMDL_COMPL)) || defined(PROTO)
1033 /*
1034  * Call vimL function "func" and return the result as a string.
1035  * Returns NULL when calling the function fails.
1036  * Uses argv[argc] for the function arguments.
1037  */
1038     void *
1039 call_func_retstr(
1040     char_u      *func,
1041     int		argc,
1042     char_u      **argv,
1043     int		safe)		/* use the sandbox */
1044 {
1045     typval_T	rettv;
1046     char_u	*retval;
1047 
1048     /* All arguments are passed as strings, no conversion to number. */
1049     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
1050 	return NULL;
1051 
1052     retval = vim_strsave(get_tv_string(&rettv));
1053     clear_tv(&rettv);
1054     return retval;
1055 }
1056 # endif
1057 
1058 /*
1059  * Call vimL function "func" and return the result as a List.
1060  * Uses argv[argc] for the function arguments.
1061  * Returns NULL when there is something wrong.
1062  */
1063     void *
1064 call_func_retlist(
1065     char_u      *func,
1066     int		argc,
1067     char_u      **argv,
1068     int		safe)		/* use the sandbox */
1069 {
1070     typval_T	rettv;
1071 
1072     /* All arguments are passed as strings, no conversion to number. */
1073     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
1074 	return NULL;
1075 
1076     if (rettv.v_type != VAR_LIST)
1077     {
1078 	clear_tv(&rettv);
1079 	return NULL;
1080     }
1081 
1082     return rettv.vval.v_list;
1083 }
1084 #endif
1085 
1086 
1087 #ifdef FEAT_FOLDING
1088 /*
1089  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
1090  * it in "*cp".  Doesn't give error messages.
1091  */
1092     int
1093 eval_foldexpr(char_u *arg, int *cp)
1094 {
1095     typval_T	tv;
1096     varnumber_T	retval;
1097     char_u	*s;
1098     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
1099 								   OPT_LOCAL);
1100 
1101     ++emsg_off;
1102     if (use_sandbox)
1103 	++sandbox;
1104     ++textlock;
1105     *cp = NUL;
1106     if (eval0(arg, &tv, NULL, TRUE) == FAIL)
1107 	retval = 0;
1108     else
1109     {
1110 	/* If the result is a number, just return the number. */
1111 	if (tv.v_type == VAR_NUMBER)
1112 	    retval = tv.vval.v_number;
1113 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
1114 	    retval = 0;
1115 	else
1116 	{
1117 	    /* If the result is a string, check if there is a non-digit before
1118 	     * the number. */
1119 	    s = tv.vval.v_string;
1120 	    if (!VIM_ISDIGIT(*s) && *s != '-')
1121 		*cp = *s++;
1122 	    retval = atol((char *)s);
1123 	}
1124 	clear_tv(&tv);
1125     }
1126     --emsg_off;
1127     if (use_sandbox)
1128 	--sandbox;
1129     --textlock;
1130 
1131     return (int)retval;
1132 }
1133 #endif
1134 
1135 /*
1136  * ":let"			list all variable values
1137  * ":let var1 var2"		list variable values
1138  * ":let var = expr"		assignment command.
1139  * ":let var += expr"		assignment command.
1140  * ":let var -= expr"		assignment command.
1141  * ":let var .= expr"		assignment command.
1142  * ":let [var1, var2] = expr"	unpack list.
1143  */
1144     void
1145 ex_let(exarg_T *eap)
1146 {
1147     char_u	*arg = eap->arg;
1148     char_u	*expr = NULL;
1149     typval_T	rettv;
1150     int		i;
1151     int		var_count = 0;
1152     int		semicolon = 0;
1153     char_u	op[2];
1154     char_u	*argend;
1155     int		first = TRUE;
1156 
1157     argend = skip_var_list(arg, &var_count, &semicolon);
1158     if (argend == NULL)
1159 	return;
1160     if (argend > arg && argend[-1] == '.')  /* for var.='str' */
1161 	--argend;
1162     expr = skipwhite(argend);
1163     if (*expr != '=' && !(vim_strchr((char_u *)"+-.", *expr) != NULL
1164 			  && expr[1] == '='))
1165     {
1166 	/*
1167 	 * ":let" without "=": list variables
1168 	 */
1169 	if (*arg == '[')
1170 	    EMSG(_(e_invarg));
1171 	else if (!ends_excmd(*arg))
1172 	    /* ":let var1 var2" */
1173 	    arg = list_arg_vars(eap, arg, &first);
1174 	else if (!eap->skip)
1175 	{
1176 	    /* ":let" */
1177 	    list_glob_vars(&first);
1178 	    list_buf_vars(&first);
1179 	    list_win_vars(&first);
1180 #ifdef FEAT_WINDOWS
1181 	    list_tab_vars(&first);
1182 #endif
1183 	    list_script_vars(&first);
1184 	    list_func_vars(&first);
1185 	    list_vim_vars(&first);
1186 	}
1187 	eap->nextcmd = check_nextcmd(arg);
1188     }
1189     else
1190     {
1191 	op[0] = '=';
1192 	op[1] = NUL;
1193 	if (*expr != '=')
1194 	{
1195 	    if (vim_strchr((char_u *)"+-.", *expr) != NULL)
1196 		op[0] = *expr;   /* +=, -= or .= */
1197 	    expr = skipwhite(expr + 2);
1198 	}
1199 	else
1200 	    expr = skipwhite(expr + 1);
1201 
1202 	if (eap->skip)
1203 	    ++emsg_skip;
1204 	i = eval0(expr, &rettv, &eap->nextcmd, !eap->skip);
1205 	if (eap->skip)
1206 	{
1207 	    if (i != FAIL)
1208 		clear_tv(&rettv);
1209 	    --emsg_skip;
1210 	}
1211 	else if (i != FAIL)
1212 	{
1213 	    (void)ex_let_vars(eap->arg, &rettv, FALSE, semicolon, var_count,
1214 									  op);
1215 	    clear_tv(&rettv);
1216 	}
1217     }
1218 }
1219 
1220 /*
1221  * Assign the typevalue "tv" to the variable or variables at "arg_start".
1222  * Handles both "var" with any type and "[var, var; var]" with a list type.
1223  * When "nextchars" is not NULL it points to a string with characters that
1224  * must appear after the variable(s).  Use "+", "-" or "." for add, subtract
1225  * or concatenate.
1226  * Returns OK or FAIL;
1227  */
1228     static int
1229 ex_let_vars(
1230     char_u	*arg_start,
1231     typval_T	*tv,
1232     int		copy,		/* copy values from "tv", don't move */
1233     int		semicolon,	/* from skip_var_list() */
1234     int		var_count,	/* from skip_var_list() */
1235     char_u	*nextchars)
1236 {
1237     char_u	*arg = arg_start;
1238     list_T	*l;
1239     int		i;
1240     listitem_T	*item;
1241     typval_T	ltv;
1242 
1243     if (*arg != '[')
1244     {
1245 	/*
1246 	 * ":let var = expr" or ":for var in list"
1247 	 */
1248 	if (ex_let_one(arg, tv, copy, nextchars, nextchars) == NULL)
1249 	    return FAIL;
1250 	return OK;
1251     }
1252 
1253     /*
1254      * ":let [v1, v2] = list" or ":for [v1, v2] in listlist"
1255      */
1256     if (tv->v_type != VAR_LIST || (l = tv->vval.v_list) == NULL)
1257     {
1258 	EMSG(_(e_listreq));
1259 	return FAIL;
1260     }
1261 
1262     i = list_len(l);
1263     if (semicolon == 0 && var_count < i)
1264     {
1265 	EMSG(_("E687: Less targets than List items"));
1266 	return FAIL;
1267     }
1268     if (var_count - semicolon > i)
1269     {
1270 	EMSG(_("E688: More targets than List items"));
1271 	return FAIL;
1272     }
1273 
1274     item = l->lv_first;
1275     while (*arg != ']')
1276     {
1277 	arg = skipwhite(arg + 1);
1278 	arg = ex_let_one(arg, &item->li_tv, TRUE, (char_u *)",;]", nextchars);
1279 	item = item->li_next;
1280 	if (arg == NULL)
1281 	    return FAIL;
1282 
1283 	arg = skipwhite(arg);
1284 	if (*arg == ';')
1285 	{
1286 	    /* Put the rest of the list (may be empty) in the var after ';'.
1287 	     * Create a new list for this. */
1288 	    l = list_alloc();
1289 	    if (l == NULL)
1290 		return FAIL;
1291 	    while (item != NULL)
1292 	    {
1293 		list_append_tv(l, &item->li_tv);
1294 		item = item->li_next;
1295 	    }
1296 
1297 	    ltv.v_type = VAR_LIST;
1298 	    ltv.v_lock = 0;
1299 	    ltv.vval.v_list = l;
1300 	    l->lv_refcount = 1;
1301 
1302 	    arg = ex_let_one(skipwhite(arg + 1), &ltv, FALSE,
1303 						    (char_u *)"]", nextchars);
1304 	    clear_tv(&ltv);
1305 	    if (arg == NULL)
1306 		return FAIL;
1307 	    break;
1308 	}
1309 	else if (*arg != ',' && *arg != ']')
1310 	{
1311 	    internal_error("ex_let_vars()");
1312 	    return FAIL;
1313 	}
1314     }
1315 
1316     return OK;
1317 }
1318 
1319 /*
1320  * Skip over assignable variable "var" or list of variables "[var, var]".
1321  * Used for ":let varvar = expr" and ":for varvar in expr".
1322  * For "[var, var]" increment "*var_count" for each variable.
1323  * for "[var, var; var]" set "semicolon".
1324  * Return NULL for an error.
1325  */
1326     static char_u *
1327 skip_var_list(
1328     char_u	*arg,
1329     int		*var_count,
1330     int		*semicolon)
1331 {
1332     char_u	*p, *s;
1333 
1334     if (*arg == '[')
1335     {
1336 	/* "[var, var]": find the matching ']'. */
1337 	p = arg;
1338 	for (;;)
1339 	{
1340 	    p = skipwhite(p + 1);	/* skip whites after '[', ';' or ',' */
1341 	    s = skip_var_one(p);
1342 	    if (s == p)
1343 	    {
1344 		EMSG2(_(e_invarg2), p);
1345 		return NULL;
1346 	    }
1347 	    ++*var_count;
1348 
1349 	    p = skipwhite(s);
1350 	    if (*p == ']')
1351 		break;
1352 	    else if (*p == ';')
1353 	    {
1354 		if (*semicolon == 1)
1355 		{
1356 		    EMSG(_("Double ; in list of variables"));
1357 		    return NULL;
1358 		}
1359 		*semicolon = 1;
1360 	    }
1361 	    else if (*p != ',')
1362 	    {
1363 		EMSG2(_(e_invarg2), p);
1364 		return NULL;
1365 	    }
1366 	}
1367 	return p + 1;
1368     }
1369     else
1370 	return skip_var_one(arg);
1371 }
1372 
1373 /*
1374  * Skip one (assignable) variable name, including @r, $VAR, &option, d.key,
1375  * l[idx].
1376  */
1377     static char_u *
1378 skip_var_one(char_u *arg)
1379 {
1380     if (*arg == '@' && arg[1] != NUL)
1381 	return arg + 2;
1382     return find_name_end(*arg == '$' || *arg == '&' ? arg + 1 : arg,
1383 				   NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1384 }
1385 
1386 /*
1387  * List variables for hashtab "ht" with prefix "prefix".
1388  * If "empty" is TRUE also list NULL strings as empty strings.
1389  */
1390     void
1391 list_hashtable_vars(
1392     hashtab_T	*ht,
1393     char_u	*prefix,
1394     int		empty,
1395     int		*first)
1396 {
1397     hashitem_T	*hi;
1398     dictitem_T	*di;
1399     int		todo;
1400 
1401     todo = (int)ht->ht_used;
1402     for (hi = ht->ht_array; todo > 0 && !got_int; ++hi)
1403     {
1404 	if (!HASHITEM_EMPTY(hi))
1405 	{
1406 	    --todo;
1407 	    di = HI2DI(hi);
1408 	    if (empty || di->di_tv.v_type != VAR_STRING
1409 					   || di->di_tv.vval.v_string != NULL)
1410 		list_one_var(di, prefix, first);
1411 	}
1412     }
1413 }
1414 
1415 /*
1416  * List global variables.
1417  */
1418     static void
1419 list_glob_vars(int *first)
1420 {
1421     list_hashtable_vars(&globvarht, (char_u *)"", TRUE, first);
1422 }
1423 
1424 /*
1425  * List buffer variables.
1426  */
1427     static void
1428 list_buf_vars(int *first)
1429 {
1430     char_u	numbuf[NUMBUFLEN];
1431 
1432     list_hashtable_vars(&curbuf->b_vars->dv_hashtab, (char_u *)"b:",
1433 								 TRUE, first);
1434 
1435     sprintf((char *)numbuf, "%ld", (long)curbuf->b_changedtick);
1436     list_one_var_a((char_u *)"b:", (char_u *)"changedtick", VAR_NUMBER,
1437 							       numbuf, first);
1438 }
1439 
1440 /*
1441  * List window variables.
1442  */
1443     static void
1444 list_win_vars(int *first)
1445 {
1446     list_hashtable_vars(&curwin->w_vars->dv_hashtab,
1447 						 (char_u *)"w:", TRUE, first);
1448 }
1449 
1450 #ifdef FEAT_WINDOWS
1451 /*
1452  * List tab page variables.
1453  */
1454     static void
1455 list_tab_vars(int *first)
1456 {
1457     list_hashtable_vars(&curtab->tp_vars->dv_hashtab,
1458 						 (char_u *)"t:", TRUE, first);
1459 }
1460 #endif
1461 
1462 /*
1463  * List Vim variables.
1464  */
1465     static void
1466 list_vim_vars(int *first)
1467 {
1468     list_hashtable_vars(&vimvarht, (char_u *)"v:", FALSE, first);
1469 }
1470 
1471 /*
1472  * List script-local variables, if there is a script.
1473  */
1474     static void
1475 list_script_vars(int *first)
1476 {
1477     if (current_SID > 0 && current_SID <= ga_scripts.ga_len)
1478 	list_hashtable_vars(&SCRIPT_VARS(current_SID),
1479 						(char_u *)"s:", FALSE, first);
1480 }
1481 
1482 /*
1483  * List variables in "arg".
1484  */
1485     static char_u *
1486 list_arg_vars(exarg_T *eap, char_u *arg, int *first)
1487 {
1488     int		error = FALSE;
1489     int		len;
1490     char_u	*name;
1491     char_u	*name_start;
1492     char_u	*arg_subsc;
1493     char_u	*tofree;
1494     typval_T    tv;
1495 
1496     while (!ends_excmd(*arg) && !got_int)
1497     {
1498 	if (error || eap->skip)
1499 	{
1500 	    arg = find_name_end(arg, NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1501 	    if (!vim_iswhite(*arg) && !ends_excmd(*arg))
1502 	    {
1503 		emsg_severe = TRUE;
1504 		EMSG(_(e_trailing));
1505 		break;
1506 	    }
1507 	}
1508 	else
1509 	{
1510 	    /* get_name_len() takes care of expanding curly braces */
1511 	    name_start = name = arg;
1512 	    len = get_name_len(&arg, &tofree, TRUE, TRUE);
1513 	    if (len <= 0)
1514 	    {
1515 		/* This is mainly to keep test 49 working: when expanding
1516 		 * curly braces fails overrule the exception error message. */
1517 		if (len < 0 && !aborting())
1518 		{
1519 		    emsg_severe = TRUE;
1520 		    EMSG2(_(e_invarg2), arg);
1521 		    break;
1522 		}
1523 		error = TRUE;
1524 	    }
1525 	    else
1526 	    {
1527 		if (tofree != NULL)
1528 		    name = tofree;
1529 		if (get_var_tv(name, len, &tv, NULL, TRUE, FALSE) == FAIL)
1530 		    error = TRUE;
1531 		else
1532 		{
1533 		    /* handle d.key, l[idx], f(expr) */
1534 		    arg_subsc = arg;
1535 		    if (handle_subscript(&arg, &tv, TRUE, TRUE) == FAIL)
1536 			error = TRUE;
1537 		    else
1538 		    {
1539 			if (arg == arg_subsc && len == 2 && name[1] == ':')
1540 			{
1541 			    switch (*name)
1542 			    {
1543 				case 'g': list_glob_vars(first); break;
1544 				case 'b': list_buf_vars(first); break;
1545 				case 'w': list_win_vars(first); break;
1546 #ifdef FEAT_WINDOWS
1547 				case 't': list_tab_vars(first); break;
1548 #endif
1549 				case 'v': list_vim_vars(first); break;
1550 				case 's': list_script_vars(first); break;
1551 				case 'l': list_func_vars(first); break;
1552 				default:
1553 					  EMSG2(_("E738: Can't list variables for %s"), name);
1554 			    }
1555 			}
1556 			else
1557 			{
1558 			    char_u	numbuf[NUMBUFLEN];
1559 			    char_u	*tf;
1560 			    int		c;
1561 			    char_u	*s;
1562 
1563 			    s = echo_string(&tv, &tf, numbuf, 0);
1564 			    c = *arg;
1565 			    *arg = NUL;
1566 			    list_one_var_a((char_u *)"",
1567 				    arg == arg_subsc ? name : name_start,
1568 				    tv.v_type,
1569 				    s == NULL ? (char_u *)"" : s,
1570 				    first);
1571 			    *arg = c;
1572 			    vim_free(tf);
1573 			}
1574 			clear_tv(&tv);
1575 		    }
1576 		}
1577 	    }
1578 
1579 	    vim_free(tofree);
1580 	}
1581 
1582 	arg = skipwhite(arg);
1583     }
1584 
1585     return arg;
1586 }
1587 
1588 /*
1589  * Set one item of ":let var = expr" or ":let [v1, v2] = list" to its value.
1590  * Returns a pointer to the char just after the var name.
1591  * Returns NULL if there is an error.
1592  */
1593     static char_u *
1594 ex_let_one(
1595     char_u	*arg,		/* points to variable name */
1596     typval_T	*tv,		/* value to assign to variable */
1597     int		copy,		/* copy value from "tv" */
1598     char_u	*endchars,	/* valid chars after variable name  or NULL */
1599     char_u	*op)		/* "+", "-", "."  or NULL*/
1600 {
1601     int		c1;
1602     char_u	*name;
1603     char_u	*p;
1604     char_u	*arg_end = NULL;
1605     int		len;
1606     int		opt_flags;
1607     char_u	*tofree = NULL;
1608 
1609     /*
1610      * ":let $VAR = expr": Set environment variable.
1611      */
1612     if (*arg == '$')
1613     {
1614 	/* Find the end of the name. */
1615 	++arg;
1616 	name = arg;
1617 	len = get_env_len(&arg);
1618 	if (len == 0)
1619 	    EMSG2(_(e_invarg2), name - 1);
1620 	else
1621 	{
1622 	    if (op != NULL && (*op == '+' || *op == '-'))
1623 		EMSG2(_(e_letwrong), op);
1624 	    else if (endchars != NULL
1625 			     && vim_strchr(endchars, *skipwhite(arg)) == NULL)
1626 		EMSG(_(e_letunexp));
1627 	    else if (!check_secure())
1628 	    {
1629 		c1 = name[len];
1630 		name[len] = NUL;
1631 		p = get_tv_string_chk(tv);
1632 		if (p != NULL && op != NULL && *op == '.')
1633 		{
1634 		    int	    mustfree = FALSE;
1635 		    char_u  *s = vim_getenv(name, &mustfree);
1636 
1637 		    if (s != NULL)
1638 		    {
1639 			p = tofree = concat_str(s, p);
1640 			if (mustfree)
1641 			    vim_free(s);
1642 		    }
1643 		}
1644 		if (p != NULL)
1645 		{
1646 		    vim_setenv(name, p);
1647 		    if (STRICMP(name, "HOME") == 0)
1648 			init_homedir();
1649 		    else if (didset_vim && STRICMP(name, "VIM") == 0)
1650 			didset_vim = FALSE;
1651 		    else if (didset_vimruntime
1652 					&& STRICMP(name, "VIMRUNTIME") == 0)
1653 			didset_vimruntime = FALSE;
1654 		    arg_end = arg;
1655 		}
1656 		name[len] = c1;
1657 		vim_free(tofree);
1658 	    }
1659 	}
1660     }
1661 
1662     /*
1663      * ":let &option = expr": Set option value.
1664      * ":let &l:option = expr": Set local option value.
1665      * ":let &g:option = expr": Set global option value.
1666      */
1667     else if (*arg == '&')
1668     {
1669 	/* Find the end of the name. */
1670 	p = find_option_end(&arg, &opt_flags);
1671 	if (p == NULL || (endchars != NULL
1672 			      && vim_strchr(endchars, *skipwhite(p)) == NULL))
1673 	    EMSG(_(e_letunexp));
1674 	else
1675 	{
1676 	    long	n;
1677 	    int		opt_type;
1678 	    long	numval;
1679 	    char_u	*stringval = NULL;
1680 	    char_u	*s;
1681 
1682 	    c1 = *p;
1683 	    *p = NUL;
1684 
1685 	    n = (long)get_tv_number(tv);
1686 	    s = get_tv_string_chk(tv);	    /* != NULL if number or string */
1687 	    if (s != NULL && op != NULL && *op != '=')
1688 	    {
1689 		opt_type = get_option_value(arg, &numval,
1690 						       &stringval, opt_flags);
1691 		if ((opt_type == 1 && *op == '.')
1692 			|| (opt_type == 0 && *op != '.'))
1693 		    EMSG2(_(e_letwrong), op);
1694 		else
1695 		{
1696 		    if (opt_type == 1)  /* number */
1697 		    {
1698 			if (*op == '+')
1699 			    n = numval + n;
1700 			else
1701 			    n = numval - n;
1702 		    }
1703 		    else if (opt_type == 0 && stringval != NULL) /* string */
1704 		    {
1705 			s = concat_str(stringval, s);
1706 			vim_free(stringval);
1707 			stringval = s;
1708 		    }
1709 		}
1710 	    }
1711 	    if (s != NULL)
1712 	    {
1713 		set_option_value(arg, n, s, opt_flags);
1714 		arg_end = p;
1715 	    }
1716 	    *p = c1;
1717 	    vim_free(stringval);
1718 	}
1719     }
1720 
1721     /*
1722      * ":let @r = expr": Set register contents.
1723      */
1724     else if (*arg == '@')
1725     {
1726 	++arg;
1727 	if (op != NULL && (*op == '+' || *op == '-'))
1728 	    EMSG2(_(e_letwrong), op);
1729 	else if (endchars != NULL
1730 			 && vim_strchr(endchars, *skipwhite(arg + 1)) == NULL)
1731 	    EMSG(_(e_letunexp));
1732 	else
1733 	{
1734 	    char_u	*ptofree = NULL;
1735 	    char_u	*s;
1736 
1737 	    p = get_tv_string_chk(tv);
1738 	    if (p != NULL && op != NULL && *op == '.')
1739 	    {
1740 		s = get_reg_contents(*arg == '@' ? '"' : *arg, GREG_EXPR_SRC);
1741 		if (s != NULL)
1742 		{
1743 		    p = ptofree = concat_str(s, p);
1744 		    vim_free(s);
1745 		}
1746 	    }
1747 	    if (p != NULL)
1748 	    {
1749 		write_reg_contents(*arg == '@' ? '"' : *arg, p, -1, FALSE);
1750 		arg_end = arg + 1;
1751 	    }
1752 	    vim_free(ptofree);
1753 	}
1754     }
1755 
1756     /*
1757      * ":let var = expr": Set internal variable.
1758      * ":let {expr} = expr": Idem, name made with curly braces
1759      */
1760     else if (eval_isnamec1(*arg) || *arg == '{')
1761     {
1762 	lval_T	lv;
1763 
1764 	p = get_lval(arg, tv, &lv, FALSE, FALSE, 0, FNE_CHECK_START);
1765 	if (p != NULL && lv.ll_name != NULL)
1766 	{
1767 	    if (endchars != NULL && vim_strchr(endchars, *skipwhite(p)) == NULL)
1768 		EMSG(_(e_letunexp));
1769 	    else
1770 	    {
1771 		set_var_lval(&lv, p, tv, copy, op);
1772 		arg_end = p;
1773 	    }
1774 	}
1775 	clear_lval(&lv);
1776     }
1777 
1778     else
1779 	EMSG2(_(e_invarg2), arg);
1780 
1781     return arg_end;
1782 }
1783 
1784 /*
1785  * If "arg" is equal to "b:changedtick" give an error and return TRUE.
1786  */
1787     int
1788 check_changedtick(char_u *arg)
1789 {
1790     if (STRNCMP(arg, "b:changedtick", 13) == 0 && !eval_isnamec(arg[13]))
1791     {
1792 	EMSG2(_(e_readonlyvar), arg);
1793 	return TRUE;
1794     }
1795     return FALSE;
1796 }
1797 
1798 /*
1799  * Get an lval: variable, Dict item or List item that can be assigned a value
1800  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
1801  * "name.key", "name.key[expr]" etc.
1802  * Indexing only works if "name" is an existing List or Dictionary.
1803  * "name" points to the start of the name.
1804  * If "rettv" is not NULL it points to the value to be assigned.
1805  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
1806  * wrong; must end in space or cmd separator.
1807  *
1808  * flags:
1809  *  GLV_QUIET:       do not give error messages
1810  *  GLV_NO_AUTOLOAD: do not use script autoloading
1811  *
1812  * Returns a pointer to just after the name, including indexes.
1813  * When an evaluation error occurs "lp->ll_name" is NULL;
1814  * Returns NULL for a parsing error.  Still need to free items in "lp"!
1815  */
1816     char_u *
1817 get_lval(
1818     char_u	*name,
1819     typval_T	*rettv,
1820     lval_T	*lp,
1821     int		unlet,
1822     int		skip,
1823     int		flags,	    /* GLV_ values */
1824     int		fne_flags)  /* flags for find_name_end() */
1825 {
1826     char_u	*p;
1827     char_u	*expr_start, *expr_end;
1828     int		cc;
1829     dictitem_T	*v;
1830     typval_T	var1;
1831     typval_T	var2;
1832     int		empty1 = FALSE;
1833     listitem_T	*ni;
1834     char_u	*key = NULL;
1835     int		len;
1836     hashtab_T	*ht;
1837     int		quiet = flags & GLV_QUIET;
1838 
1839     /* Clear everything in "lp". */
1840     vim_memset(lp, 0, sizeof(lval_T));
1841 
1842     if (skip)
1843     {
1844 	/* When skipping just find the end of the name. */
1845 	lp->ll_name = name;
1846 	return find_name_end(name, NULL, NULL, FNE_INCL_BR | fne_flags);
1847     }
1848 
1849     /* Find the end of the name. */
1850     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
1851     if (expr_start != NULL)
1852     {
1853 	/* Don't expand the name when we already know there is an error. */
1854 	if (unlet && !vim_iswhite(*p) && !ends_excmd(*p)
1855 						    && *p != '[' && *p != '.')
1856 	{
1857 	    EMSG(_(e_trailing));
1858 	    return NULL;
1859 	}
1860 
1861 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
1862 	if (lp->ll_exp_name == NULL)
1863 	{
1864 	    /* Report an invalid expression in braces, unless the
1865 	     * expression evaluation has been cancelled due to an
1866 	     * aborting error, an interrupt, or an exception. */
1867 	    if (!aborting() && !quiet)
1868 	    {
1869 		emsg_severe = TRUE;
1870 		EMSG2(_(e_invarg2), name);
1871 		return NULL;
1872 	    }
1873 	}
1874 	lp->ll_name = lp->ll_exp_name;
1875     }
1876     else
1877 	lp->ll_name = name;
1878 
1879     /* Without [idx] or .key we are done. */
1880     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
1881 	return p;
1882 
1883     cc = *p;
1884     *p = NUL;
1885     v = find_var(lp->ll_name, &ht, flags & GLV_NO_AUTOLOAD);
1886     if (v == NULL && !quiet)
1887 	EMSG2(_(e_undefvar), lp->ll_name);
1888     *p = cc;
1889     if (v == NULL)
1890 	return NULL;
1891 
1892     /*
1893      * Loop until no more [idx] or .key is following.
1894      */
1895     lp->ll_tv = &v->di_tv;
1896     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
1897     {
1898 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
1899 		&& !(lp->ll_tv->v_type == VAR_DICT
1900 					   && lp->ll_tv->vval.v_dict != NULL))
1901 	{
1902 	    if (!quiet)
1903 		EMSG(_("E689: Can only index a List or Dictionary"));
1904 	    return NULL;
1905 	}
1906 	if (lp->ll_range)
1907 	{
1908 	    if (!quiet)
1909 		EMSG(_("E708: [:] must come last"));
1910 	    return NULL;
1911 	}
1912 
1913 	len = -1;
1914 	if (*p == '.')
1915 	{
1916 	    key = p + 1;
1917 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
1918 		;
1919 	    if (len == 0)
1920 	    {
1921 		if (!quiet)
1922 		    EMSG(_(e_emptykey));
1923 		return NULL;
1924 	    }
1925 	    p = key + len;
1926 	}
1927 	else
1928 	{
1929 	    /* Get the index [expr] or the first index [expr: ]. */
1930 	    p = skipwhite(p + 1);
1931 	    if (*p == ':')
1932 		empty1 = TRUE;
1933 	    else
1934 	    {
1935 		empty1 = FALSE;
1936 		if (eval1(&p, &var1, TRUE) == FAIL)	/* recursive! */
1937 		    return NULL;
1938 		if (get_tv_string_chk(&var1) == NULL)
1939 		{
1940 		    /* not a number or string */
1941 		    clear_tv(&var1);
1942 		    return NULL;
1943 		}
1944 	    }
1945 
1946 	    /* Optionally get the second index [ :expr]. */
1947 	    if (*p == ':')
1948 	    {
1949 		if (lp->ll_tv->v_type == VAR_DICT)
1950 		{
1951 		    if (!quiet)
1952 			EMSG(_(e_dictrange));
1953 		    if (!empty1)
1954 			clear_tv(&var1);
1955 		    return NULL;
1956 		}
1957 		if (rettv != NULL && (rettv->v_type != VAR_LIST
1958 					       || rettv->vval.v_list == NULL))
1959 		{
1960 		    if (!quiet)
1961 			EMSG(_("E709: [:] requires a List value"));
1962 		    if (!empty1)
1963 			clear_tv(&var1);
1964 		    return NULL;
1965 		}
1966 		p = skipwhite(p + 1);
1967 		if (*p == ']')
1968 		    lp->ll_empty2 = TRUE;
1969 		else
1970 		{
1971 		    lp->ll_empty2 = FALSE;
1972 		    if (eval1(&p, &var2, TRUE) == FAIL)	/* recursive! */
1973 		    {
1974 			if (!empty1)
1975 			    clear_tv(&var1);
1976 			return NULL;
1977 		    }
1978 		    if (get_tv_string_chk(&var2) == NULL)
1979 		    {
1980 			/* not a number or string */
1981 			if (!empty1)
1982 			    clear_tv(&var1);
1983 			clear_tv(&var2);
1984 			return NULL;
1985 		    }
1986 		}
1987 		lp->ll_range = TRUE;
1988 	    }
1989 	    else
1990 		lp->ll_range = FALSE;
1991 
1992 	    if (*p != ']')
1993 	    {
1994 		if (!quiet)
1995 		    EMSG(_(e_missbrac));
1996 		if (!empty1)
1997 		    clear_tv(&var1);
1998 		if (lp->ll_range && !lp->ll_empty2)
1999 		    clear_tv(&var2);
2000 		return NULL;
2001 	    }
2002 
2003 	    /* Skip to past ']'. */
2004 	    ++p;
2005 	}
2006 
2007 	if (lp->ll_tv->v_type == VAR_DICT)
2008 	{
2009 	    if (len == -1)
2010 	    {
2011 		/* "[key]": get key from "var1" */
2012 		key = get_tv_string_chk(&var1);	/* is number or string */
2013 		if (key == NULL)
2014 		{
2015 		    clear_tv(&var1);
2016 		    return NULL;
2017 		}
2018 	    }
2019 	    lp->ll_list = NULL;
2020 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
2021 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
2022 
2023 	    /* When assigning to a scope dictionary check that a function and
2024 	     * variable name is valid (only variable name unless it is l: or
2025 	     * g: dictionary). Disallow overwriting a builtin function. */
2026 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
2027 	    {
2028 		int prevval;
2029 		int wrong;
2030 
2031 		if (len != -1)
2032 		{
2033 		    prevval = key[len];
2034 		    key[len] = NUL;
2035 		}
2036 		else
2037 		    prevval = 0; /* avoid compiler warning */
2038 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
2039 			       && rettv->v_type == VAR_FUNC
2040 			       && var_check_func_name(key, lp->ll_di == NULL))
2041 			|| !valid_varname(key);
2042 		if (len != -1)
2043 		    key[len] = prevval;
2044 		if (wrong)
2045 		    return NULL;
2046 	    }
2047 
2048 	    if (lp->ll_di == NULL)
2049 	    {
2050 		/* Can't add "v:" variable. */
2051 		if (lp->ll_dict == &vimvardict)
2052 		{
2053 		    EMSG2(_(e_illvar), name);
2054 		    return NULL;
2055 		}
2056 
2057 		/* Key does not exist in dict: may need to add it. */
2058 		if (*p == '[' || *p == '.' || unlet)
2059 		{
2060 		    if (!quiet)
2061 			EMSG2(_(e_dictkey), key);
2062 		    if (len == -1)
2063 			clear_tv(&var1);
2064 		    return NULL;
2065 		}
2066 		if (len == -1)
2067 		    lp->ll_newkey = vim_strsave(key);
2068 		else
2069 		    lp->ll_newkey = vim_strnsave(key, len);
2070 		if (len == -1)
2071 		    clear_tv(&var1);
2072 		if (lp->ll_newkey == NULL)
2073 		    p = NULL;
2074 		break;
2075 	    }
2076 	    /* existing variable, need to check if it can be changed */
2077 	    else if (var_check_ro(lp->ll_di->di_flags, name, FALSE))
2078 		return NULL;
2079 
2080 	    if (len == -1)
2081 		clear_tv(&var1);
2082 	    lp->ll_tv = &lp->ll_di->di_tv;
2083 	}
2084 	else
2085 	{
2086 	    /*
2087 	     * Get the number and item for the only or first index of the List.
2088 	     */
2089 	    if (empty1)
2090 		lp->ll_n1 = 0;
2091 	    else
2092 	    {
2093 		lp->ll_n1 = (long)get_tv_number(&var1);
2094 						    /* is number or string */
2095 		clear_tv(&var1);
2096 	    }
2097 	    lp->ll_dict = NULL;
2098 	    lp->ll_list = lp->ll_tv->vval.v_list;
2099 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2100 	    if (lp->ll_li == NULL)
2101 	    {
2102 		if (lp->ll_n1 < 0)
2103 		{
2104 		    lp->ll_n1 = 0;
2105 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2106 		}
2107 	    }
2108 	    if (lp->ll_li == NULL)
2109 	    {
2110 		if (lp->ll_range && !lp->ll_empty2)
2111 		    clear_tv(&var2);
2112 		if (!quiet)
2113 		    EMSGN(_(e_listidx), lp->ll_n1);
2114 		return NULL;
2115 	    }
2116 
2117 	    /*
2118 	     * May need to find the item or absolute index for the second
2119 	     * index of a range.
2120 	     * When no index given: "lp->ll_empty2" is TRUE.
2121 	     * Otherwise "lp->ll_n2" is set to the second index.
2122 	     */
2123 	    if (lp->ll_range && !lp->ll_empty2)
2124 	    {
2125 		lp->ll_n2 = (long)get_tv_number(&var2);
2126 						    /* is number or string */
2127 		clear_tv(&var2);
2128 		if (lp->ll_n2 < 0)
2129 		{
2130 		    ni = list_find(lp->ll_list, lp->ll_n2);
2131 		    if (ni == NULL)
2132 		    {
2133 			if (!quiet)
2134 			    EMSGN(_(e_listidx), lp->ll_n2);
2135 			return NULL;
2136 		    }
2137 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
2138 		}
2139 
2140 		/* Check that lp->ll_n2 isn't before lp->ll_n1. */
2141 		if (lp->ll_n1 < 0)
2142 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
2143 		if (lp->ll_n2 < lp->ll_n1)
2144 		{
2145 		    if (!quiet)
2146 			EMSGN(_(e_listidx), lp->ll_n2);
2147 		    return NULL;
2148 		}
2149 	    }
2150 
2151 	    lp->ll_tv = &lp->ll_li->li_tv;
2152 	}
2153     }
2154 
2155     return p;
2156 }
2157 
2158 /*
2159  * Clear lval "lp" that was filled by get_lval().
2160  */
2161     void
2162 clear_lval(lval_T *lp)
2163 {
2164     vim_free(lp->ll_exp_name);
2165     vim_free(lp->ll_newkey);
2166 }
2167 
2168 /*
2169  * Set a variable that was parsed by get_lval() to "rettv".
2170  * "endp" points to just after the parsed name.
2171  * "op" is NULL, "+" for "+=", "-" for "-=", "." for ".=" or "=" for "=".
2172  */
2173     static void
2174 set_var_lval(
2175     lval_T	*lp,
2176     char_u	*endp,
2177     typval_T	*rettv,
2178     int		copy,
2179     char_u	*op)
2180 {
2181     int		cc;
2182     listitem_T	*ri;
2183     dictitem_T	*di;
2184 
2185     if (lp->ll_tv == NULL)
2186     {
2187 	if (!check_changedtick(lp->ll_name))
2188 	{
2189 	    cc = *endp;
2190 	    *endp = NUL;
2191 	    if (op != NULL && *op != '=')
2192 	    {
2193 		typval_T tv;
2194 
2195 		/* handle +=, -= and .= */
2196 		di = NULL;
2197 		if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
2198 						 &tv, &di, TRUE, FALSE) == OK)
2199 		{
2200 		    if ((di == NULL
2201 			   || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
2202 			      && !tv_check_lock(di->di_tv.v_lock, lp->ll_name,
2203 								      FALSE)))
2204 			    && tv_op(&tv, rettv, op) == OK)
2205 			set_var(lp->ll_name, &tv, FALSE);
2206 		    clear_tv(&tv);
2207 		}
2208 	    }
2209 	    else
2210 		set_var(lp->ll_name, rettv, copy);
2211 	    *endp = cc;
2212 	}
2213     }
2214     else if (tv_check_lock(lp->ll_newkey == NULL
2215 		? lp->ll_tv->v_lock
2216 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
2217 	;
2218     else if (lp->ll_range)
2219     {
2220 	listitem_T *ll_li = lp->ll_li;
2221 	int ll_n1 = lp->ll_n1;
2222 
2223 	/*
2224 	 * Check whether any of the list items is locked
2225 	 */
2226 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
2227 	{
2228 	    if (tv_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
2229 		return;
2230 	    ri = ri->li_next;
2231 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
2232 		break;
2233 	    ll_li = ll_li->li_next;
2234 	    ++ll_n1;
2235 	}
2236 
2237 	/*
2238 	 * Assign the List values to the list items.
2239 	 */
2240 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
2241 	{
2242 	    if (op != NULL && *op != '=')
2243 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
2244 	    else
2245 	    {
2246 		clear_tv(&lp->ll_li->li_tv);
2247 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
2248 	    }
2249 	    ri = ri->li_next;
2250 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
2251 		break;
2252 	    if (lp->ll_li->li_next == NULL)
2253 	    {
2254 		/* Need to add an empty item. */
2255 		if (list_append_number(lp->ll_list, 0) == FAIL)
2256 		{
2257 		    ri = NULL;
2258 		    break;
2259 		}
2260 	    }
2261 	    lp->ll_li = lp->ll_li->li_next;
2262 	    ++lp->ll_n1;
2263 	}
2264 	if (ri != NULL)
2265 	    EMSG(_("E710: List value has more items than target"));
2266 	else if (lp->ll_empty2
2267 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
2268 		: lp->ll_n1 != lp->ll_n2)
2269 	    EMSG(_("E711: List value has not enough items"));
2270     }
2271     else
2272     {
2273 	/*
2274 	 * Assign to a List or Dictionary item.
2275 	 */
2276 	if (lp->ll_newkey != NULL)
2277 	{
2278 	    if (op != NULL && *op != '=')
2279 	    {
2280 		EMSG2(_(e_letwrong), op);
2281 		return;
2282 	    }
2283 
2284 	    /* Need to add an item to the Dictionary. */
2285 	    di = dictitem_alloc(lp->ll_newkey);
2286 	    if (di == NULL)
2287 		return;
2288 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
2289 	    {
2290 		vim_free(di);
2291 		return;
2292 	    }
2293 	    lp->ll_tv = &di->di_tv;
2294 	}
2295 	else if (op != NULL && *op != '=')
2296 	{
2297 	    tv_op(lp->ll_tv, rettv, op);
2298 	    return;
2299 	}
2300 	else
2301 	    clear_tv(lp->ll_tv);
2302 
2303 	/*
2304 	 * Assign the value to the variable or list item.
2305 	 */
2306 	if (copy)
2307 	    copy_tv(rettv, lp->ll_tv);
2308 	else
2309 	{
2310 	    *lp->ll_tv = *rettv;
2311 	    lp->ll_tv->v_lock = 0;
2312 	    init_tv(rettv);
2313 	}
2314     }
2315 }
2316 
2317 /*
2318  * Handle "tv1 += tv2", "tv1 -= tv2" and "tv1 .= tv2"
2319  * Returns OK or FAIL.
2320  */
2321     static int
2322 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
2323 {
2324     varnumber_T	n;
2325     char_u	numbuf[NUMBUFLEN];
2326     char_u	*s;
2327 
2328     /* Can't do anything with a Funcref, Dict, v:true on the right. */
2329     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
2330 						&& tv2->v_type != VAR_SPECIAL)
2331     {
2332 	switch (tv1->v_type)
2333 	{
2334 	    case VAR_UNKNOWN:
2335 	    case VAR_DICT:
2336 	    case VAR_FUNC:
2337 	    case VAR_PARTIAL:
2338 	    case VAR_SPECIAL:
2339 	    case VAR_JOB:
2340 	    case VAR_CHANNEL:
2341 		break;
2342 
2343 	    case VAR_LIST:
2344 		if (*op != '+' || tv2->v_type != VAR_LIST)
2345 		    break;
2346 		/* List += List */
2347 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
2348 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
2349 		return OK;
2350 
2351 	    case VAR_NUMBER:
2352 	    case VAR_STRING:
2353 		if (tv2->v_type == VAR_LIST)
2354 		    break;
2355 		if (*op == '+' || *op == '-')
2356 		{
2357 		    /* nr += nr  or  nr -= nr*/
2358 		    n = get_tv_number(tv1);
2359 #ifdef FEAT_FLOAT
2360 		    if (tv2->v_type == VAR_FLOAT)
2361 		    {
2362 			float_T f = n;
2363 
2364 			if (*op == '+')
2365 			    f += tv2->vval.v_float;
2366 			else
2367 			    f -= tv2->vval.v_float;
2368 			clear_tv(tv1);
2369 			tv1->v_type = VAR_FLOAT;
2370 			tv1->vval.v_float = f;
2371 		    }
2372 		    else
2373 #endif
2374 		    {
2375 			if (*op == '+')
2376 			    n += get_tv_number(tv2);
2377 			else
2378 			    n -= get_tv_number(tv2);
2379 			clear_tv(tv1);
2380 			tv1->v_type = VAR_NUMBER;
2381 			tv1->vval.v_number = n;
2382 		    }
2383 		}
2384 		else
2385 		{
2386 		    if (tv2->v_type == VAR_FLOAT)
2387 			break;
2388 
2389 		    /* str .= str */
2390 		    s = get_tv_string(tv1);
2391 		    s = concat_str(s, get_tv_string_buf(tv2, numbuf));
2392 		    clear_tv(tv1);
2393 		    tv1->v_type = VAR_STRING;
2394 		    tv1->vval.v_string = s;
2395 		}
2396 		return OK;
2397 
2398 	    case VAR_FLOAT:
2399 #ifdef FEAT_FLOAT
2400 		{
2401 		    float_T f;
2402 
2403 		    if (*op == '.' || (tv2->v_type != VAR_FLOAT
2404 				    && tv2->v_type != VAR_NUMBER
2405 				    && tv2->v_type != VAR_STRING))
2406 			break;
2407 		    if (tv2->v_type == VAR_FLOAT)
2408 			f = tv2->vval.v_float;
2409 		    else
2410 			f = get_tv_number(tv2);
2411 		    if (*op == '+')
2412 			tv1->vval.v_float += f;
2413 		    else
2414 			tv1->vval.v_float -= f;
2415 		}
2416 #endif
2417 		return OK;
2418 	}
2419     }
2420 
2421     EMSG2(_(e_letwrong), op);
2422     return FAIL;
2423 }
2424 
2425 /*
2426  * Evaluate the expression used in a ":for var in expr" command.
2427  * "arg" points to "var".
2428  * Set "*errp" to TRUE for an error, FALSE otherwise;
2429  * Return a pointer that holds the info.  Null when there is an error.
2430  */
2431     void *
2432 eval_for_line(
2433     char_u	*arg,
2434     int		*errp,
2435     char_u	**nextcmdp,
2436     int		skip)
2437 {
2438     forinfo_T	*fi;
2439     char_u	*expr;
2440     typval_T	tv;
2441     list_T	*l;
2442 
2443     *errp = TRUE;	/* default: there is an error */
2444 
2445     fi = (forinfo_T *)alloc_clear(sizeof(forinfo_T));
2446     if (fi == NULL)
2447 	return NULL;
2448 
2449     expr = skip_var_list(arg, &fi->fi_varcount, &fi->fi_semicolon);
2450     if (expr == NULL)
2451 	return fi;
2452 
2453     expr = skipwhite(expr);
2454     if (expr[0] != 'i' || expr[1] != 'n' || !vim_iswhite(expr[2]))
2455     {
2456 	EMSG(_("E690: Missing \"in\" after :for"));
2457 	return fi;
2458     }
2459 
2460     if (skip)
2461 	++emsg_skip;
2462     if (eval0(skipwhite(expr + 2), &tv, nextcmdp, !skip) == OK)
2463     {
2464 	*errp = FALSE;
2465 	if (!skip)
2466 	{
2467 	    l = tv.vval.v_list;
2468 	    if (tv.v_type != VAR_LIST)
2469 	    {
2470 		EMSG(_(e_listreq));
2471 		clear_tv(&tv);
2472 	    }
2473 	    else if (l == NULL)
2474 	    {
2475 		/* a null list is like an empty list: do nothing */
2476 		clear_tv(&tv);
2477 	    }
2478 	    else
2479 	    {
2480 		/* No need to increment the refcount, it's already set for the
2481 		 * list being used in "tv". */
2482 		fi->fi_list = l;
2483 		list_add_watch(l, &fi->fi_lw);
2484 		fi->fi_lw.lw_item = l->lv_first;
2485 	    }
2486 	}
2487     }
2488     if (skip)
2489 	--emsg_skip;
2490 
2491     return fi;
2492 }
2493 
2494 /*
2495  * Use the first item in a ":for" list.  Advance to the next.
2496  * Assign the values to the variable (list).  "arg" points to the first one.
2497  * Return TRUE when a valid item was found, FALSE when at end of list or
2498  * something wrong.
2499  */
2500     int
2501 next_for_item(void *fi_void, char_u *arg)
2502 {
2503     forinfo_T	*fi = (forinfo_T *)fi_void;
2504     int		result;
2505     listitem_T	*item;
2506 
2507     item = fi->fi_lw.lw_item;
2508     if (item == NULL)
2509 	result = FALSE;
2510     else
2511     {
2512 	fi->fi_lw.lw_item = item->li_next;
2513 	result = (ex_let_vars(arg, &item->li_tv, TRUE,
2514 			      fi->fi_semicolon, fi->fi_varcount, NULL) == OK);
2515     }
2516     return result;
2517 }
2518 
2519 /*
2520  * Free the structure used to store info used by ":for".
2521  */
2522     void
2523 free_for_info(void *fi_void)
2524 {
2525     forinfo_T    *fi = (forinfo_T *)fi_void;
2526 
2527     if (fi != NULL && fi->fi_list != NULL)
2528     {
2529 	list_rem_watch(fi->fi_list, &fi->fi_lw);
2530 	list_unref(fi->fi_list);
2531     }
2532     vim_free(fi);
2533 }
2534 
2535 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
2536 
2537     void
2538 set_context_for_expression(
2539     expand_T	*xp,
2540     char_u	*arg,
2541     cmdidx_T	cmdidx)
2542 {
2543     int		got_eq = FALSE;
2544     int		c;
2545     char_u	*p;
2546 
2547     if (cmdidx == CMD_let)
2548     {
2549 	xp->xp_context = EXPAND_USER_VARS;
2550 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
2551 	{
2552 	    /* ":let var1 var2 ...": find last space. */
2553 	    for (p = arg + STRLEN(arg); p >= arg; )
2554 	    {
2555 		xp->xp_pattern = p;
2556 		mb_ptr_back(arg, p);
2557 		if (vim_iswhite(*p))
2558 		    break;
2559 	    }
2560 	    return;
2561 	}
2562     }
2563     else
2564 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
2565 							  : EXPAND_EXPRESSION;
2566     while ((xp->xp_pattern = vim_strpbrk(arg,
2567 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
2568     {
2569 	c = *xp->xp_pattern;
2570 	if (c == '&')
2571 	{
2572 	    c = xp->xp_pattern[1];
2573 	    if (c == '&')
2574 	    {
2575 		++xp->xp_pattern;
2576 		xp->xp_context = cmdidx != CMD_let || got_eq
2577 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
2578 	    }
2579 	    else if (c != ' ')
2580 	    {
2581 		xp->xp_context = EXPAND_SETTINGS;
2582 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
2583 		    xp->xp_pattern += 2;
2584 
2585 	    }
2586 	}
2587 	else if (c == '$')
2588 	{
2589 	    /* environment variable */
2590 	    xp->xp_context = EXPAND_ENV_VARS;
2591 	}
2592 	else if (c == '=')
2593 	{
2594 	    got_eq = TRUE;
2595 	    xp->xp_context = EXPAND_EXPRESSION;
2596 	}
2597 	else if (c == '#'
2598 		&& xp->xp_context == EXPAND_EXPRESSION)
2599 	{
2600 	    /* Autoload function/variable contains '#'. */
2601 	    break;
2602 	}
2603 	else if ((c == '<' || c == '#')
2604 		&& xp->xp_context == EXPAND_FUNCTIONS
2605 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
2606 	{
2607 	    /* Function name can start with "<SNR>" and contain '#'. */
2608 	    break;
2609 	}
2610 	else if (cmdidx != CMD_let || got_eq)
2611 	{
2612 	    if (c == '"')	    /* string */
2613 	    {
2614 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
2615 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
2616 			++xp->xp_pattern;
2617 		xp->xp_context = EXPAND_NOTHING;
2618 	    }
2619 	    else if (c == '\'')	    /* literal string */
2620 	    {
2621 		/* Trick: '' is like stopping and starting a literal string. */
2622 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
2623 		    /* skip */ ;
2624 		xp->xp_context = EXPAND_NOTHING;
2625 	    }
2626 	    else if (c == '|')
2627 	    {
2628 		if (xp->xp_pattern[1] == '|')
2629 		{
2630 		    ++xp->xp_pattern;
2631 		    xp->xp_context = EXPAND_EXPRESSION;
2632 		}
2633 		else
2634 		    xp->xp_context = EXPAND_COMMANDS;
2635 	    }
2636 	    else
2637 		xp->xp_context = EXPAND_EXPRESSION;
2638 	}
2639 	else
2640 	    /* Doesn't look like something valid, expand as an expression
2641 	     * anyway. */
2642 	    xp->xp_context = EXPAND_EXPRESSION;
2643 	arg = xp->xp_pattern;
2644 	if (*arg != NUL)
2645 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
2646 		/* skip */ ;
2647     }
2648     xp->xp_pattern = arg;
2649 }
2650 
2651 #endif /* FEAT_CMDL_COMPL */
2652 
2653 /*
2654  * ":unlet[!] var1 ... " command.
2655  */
2656     void
2657 ex_unlet(exarg_T *eap)
2658 {
2659     ex_unletlock(eap, eap->arg, 0);
2660 }
2661 
2662 /*
2663  * ":lockvar" and ":unlockvar" commands
2664  */
2665     void
2666 ex_lockvar(exarg_T *eap)
2667 {
2668     char_u	*arg = eap->arg;
2669     int		deep = 2;
2670 
2671     if (eap->forceit)
2672 	deep = -1;
2673     else if (vim_isdigit(*arg))
2674     {
2675 	deep = getdigits(&arg);
2676 	arg = skipwhite(arg);
2677     }
2678 
2679     ex_unletlock(eap, arg, deep);
2680 }
2681 
2682 /*
2683  * ":unlet", ":lockvar" and ":unlockvar" are quite similar.
2684  */
2685     static void
2686 ex_unletlock(
2687     exarg_T	*eap,
2688     char_u	*argstart,
2689     int		deep)
2690 {
2691     char_u	*arg = argstart;
2692     char_u	*name_end;
2693     int		error = FALSE;
2694     lval_T	lv;
2695 
2696     do
2697     {
2698 	/* Parse the name and find the end. */
2699 	name_end = get_lval(arg, NULL, &lv, TRUE, eap->skip || error, 0,
2700 							     FNE_CHECK_START);
2701 	if (lv.ll_name == NULL)
2702 	    error = TRUE;	    /* error but continue parsing */
2703 	if (name_end == NULL || (!vim_iswhite(*name_end)
2704 						   && !ends_excmd(*name_end)))
2705 	{
2706 	    if (name_end != NULL)
2707 	    {
2708 		emsg_severe = TRUE;
2709 		EMSG(_(e_trailing));
2710 	    }
2711 	    if (!(eap->skip || error))
2712 		clear_lval(&lv);
2713 	    break;
2714 	}
2715 
2716 	if (!error && !eap->skip)
2717 	{
2718 	    if (eap->cmdidx == CMD_unlet)
2719 	    {
2720 		if (do_unlet_var(&lv, name_end, eap->forceit) == FAIL)
2721 		    error = TRUE;
2722 	    }
2723 	    else
2724 	    {
2725 		if (do_lock_var(&lv, name_end, deep,
2726 					  eap->cmdidx == CMD_lockvar) == FAIL)
2727 		    error = TRUE;
2728 	    }
2729 	}
2730 
2731 	if (!eap->skip)
2732 	    clear_lval(&lv);
2733 
2734 	arg = skipwhite(name_end);
2735     } while (!ends_excmd(*arg));
2736 
2737     eap->nextcmd = check_nextcmd(arg);
2738 }
2739 
2740     static int
2741 do_unlet_var(
2742     lval_T	*lp,
2743     char_u	*name_end,
2744     int		forceit)
2745 {
2746     int		ret = OK;
2747     int		cc;
2748 
2749     if (lp->ll_tv == NULL)
2750     {
2751 	cc = *name_end;
2752 	*name_end = NUL;
2753 
2754 	/* Normal name or expanded name. */
2755 	if (check_changedtick(lp->ll_name))
2756 	    ret = FAIL;
2757 	else if (do_unlet(lp->ll_name, forceit) == FAIL)
2758 	    ret = FAIL;
2759 	*name_end = cc;
2760     }
2761     else if ((lp->ll_list != NULL
2762 		   && tv_check_lock(lp->ll_list->lv_lock, lp->ll_name, FALSE))
2763 	    || (lp->ll_dict != NULL
2764 		  && tv_check_lock(lp->ll_dict->dv_lock, lp->ll_name, FALSE)))
2765 	return FAIL;
2766     else if (lp->ll_range)
2767     {
2768 	listitem_T    *li;
2769 	listitem_T    *ll_li = lp->ll_li;
2770 	int	      ll_n1 = lp->ll_n1;
2771 
2772 	while (ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= ll_n1))
2773 	{
2774 	    li = ll_li->li_next;
2775 	    if (tv_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
2776 		return FAIL;
2777 	    ll_li = li;
2778 	    ++ll_n1;
2779 	}
2780 
2781 	/* Delete a range of List items. */
2782 	while (lp->ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
2783 	{
2784 	    li = lp->ll_li->li_next;
2785 	    listitem_remove(lp->ll_list, lp->ll_li);
2786 	    lp->ll_li = li;
2787 	    ++lp->ll_n1;
2788 	}
2789     }
2790     else
2791     {
2792 	if (lp->ll_list != NULL)
2793 	    /* unlet a List item. */
2794 	    listitem_remove(lp->ll_list, lp->ll_li);
2795 	else
2796 	    /* unlet a Dictionary item. */
2797 	    dictitem_remove(lp->ll_dict, lp->ll_di);
2798     }
2799 
2800     return ret;
2801 }
2802 
2803 /*
2804  * "unlet" a variable.  Return OK if it existed, FAIL if not.
2805  * When "forceit" is TRUE don't complain if the variable doesn't exist.
2806  */
2807     int
2808 do_unlet(char_u *name, int forceit)
2809 {
2810     hashtab_T	*ht;
2811     hashitem_T	*hi;
2812     char_u	*varname;
2813     dict_T	*d;
2814     dictitem_T	*di;
2815 
2816     ht = find_var_ht(name, &varname);
2817     if (ht != NULL && *varname != NUL)
2818     {
2819 	d = get_current_funccal_dict(ht);
2820 	if (d == NULL)
2821 	{
2822 	    if (ht == &globvarht)
2823 		d = &globvardict;
2824 	    else if (ht == &compat_hashtab)
2825 		d = &vimvardict;
2826 	    else
2827 	    {
2828 		di = find_var_in_ht(ht, *name, (char_u *)"", FALSE);
2829 		d = di == NULL ? NULL : di->di_tv.vval.v_dict;
2830 	    }
2831 	    if (d == NULL)
2832 	    {
2833 		internal_error("do_unlet()");
2834 		return FAIL;
2835 	    }
2836 	}
2837 	hi = hash_find(ht, varname);
2838 	if (HASHITEM_EMPTY(hi))
2839 	    hi = find_hi_in_scoped_ht(name, &ht);
2840 	if (hi != NULL && !HASHITEM_EMPTY(hi))
2841 	{
2842 	    di = HI2DI(hi);
2843 	    if (var_check_fixed(di->di_flags, name, FALSE)
2844 		    || var_check_ro(di->di_flags, name, FALSE)
2845 		    || tv_check_lock(d->dv_lock, name, FALSE))
2846 		return FAIL;
2847 
2848 	    delete_var(ht, hi);
2849 	    return OK;
2850 	}
2851     }
2852     if (forceit)
2853 	return OK;
2854     EMSG2(_("E108: No such variable: \"%s\""), name);
2855     return FAIL;
2856 }
2857 
2858 /*
2859  * Lock or unlock variable indicated by "lp".
2860  * "deep" is the levels to go (-1 for unlimited);
2861  * "lock" is TRUE for ":lockvar", FALSE for ":unlockvar".
2862  */
2863     static int
2864 do_lock_var(
2865     lval_T	*lp,
2866     char_u	*name_end,
2867     int		deep,
2868     int		lock)
2869 {
2870     int		ret = OK;
2871     int		cc;
2872     dictitem_T	*di;
2873 
2874     if (deep == 0)	/* nothing to do */
2875 	return OK;
2876 
2877     if (lp->ll_tv == NULL)
2878     {
2879 	cc = *name_end;
2880 	*name_end = NUL;
2881 
2882 	/* Normal name or expanded name. */
2883 	if (check_changedtick(lp->ll_name))
2884 	    ret = FAIL;
2885 	else
2886 	{
2887 	    di = find_var(lp->ll_name, NULL, TRUE);
2888 	    if (di == NULL)
2889 		ret = FAIL;
2890 	    else
2891 	    {
2892 		if (lock)
2893 		    di->di_flags |= DI_FLAGS_LOCK;
2894 		else
2895 		    di->di_flags &= ~DI_FLAGS_LOCK;
2896 		item_lock(&di->di_tv, deep, lock);
2897 	    }
2898 	}
2899 	*name_end = cc;
2900     }
2901     else if (lp->ll_range)
2902     {
2903 	listitem_T    *li = lp->ll_li;
2904 
2905 	/* (un)lock a range of List items. */
2906 	while (li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
2907 	{
2908 	    item_lock(&li->li_tv, deep, lock);
2909 	    li = li->li_next;
2910 	    ++lp->ll_n1;
2911 	}
2912     }
2913     else if (lp->ll_list != NULL)
2914 	/* (un)lock a List item. */
2915 	item_lock(&lp->ll_li->li_tv, deep, lock);
2916     else
2917 	/* (un)lock a Dictionary item. */
2918 	item_lock(&lp->ll_di->di_tv, deep, lock);
2919 
2920     return ret;
2921 }
2922 
2923 /*
2924  * Lock or unlock an item.  "deep" is nr of levels to go.
2925  */
2926     static void
2927 item_lock(typval_T *tv, int deep, int lock)
2928 {
2929     static int	recurse = 0;
2930     list_T	*l;
2931     listitem_T	*li;
2932     dict_T	*d;
2933     hashitem_T	*hi;
2934     int		todo;
2935 
2936     if (recurse >= DICT_MAXNEST)
2937     {
2938 	EMSG(_("E743: variable nested too deep for (un)lock"));
2939 	return;
2940     }
2941     if (deep == 0)
2942 	return;
2943     ++recurse;
2944 
2945     /* lock/unlock the item itself */
2946     if (lock)
2947 	tv->v_lock |= VAR_LOCKED;
2948     else
2949 	tv->v_lock &= ~VAR_LOCKED;
2950 
2951     switch (tv->v_type)
2952     {
2953 	case VAR_UNKNOWN:
2954 	case VAR_NUMBER:
2955 	case VAR_STRING:
2956 	case VAR_FUNC:
2957 	case VAR_PARTIAL:
2958 	case VAR_FLOAT:
2959 	case VAR_SPECIAL:
2960 	case VAR_JOB:
2961 	case VAR_CHANNEL:
2962 	    break;
2963 
2964 	case VAR_LIST:
2965 	    if ((l = tv->vval.v_list) != NULL)
2966 	    {
2967 		if (lock)
2968 		    l->lv_lock |= VAR_LOCKED;
2969 		else
2970 		    l->lv_lock &= ~VAR_LOCKED;
2971 		if (deep < 0 || deep > 1)
2972 		    /* recursive: lock/unlock the items the List contains */
2973 		    for (li = l->lv_first; li != NULL; li = li->li_next)
2974 			item_lock(&li->li_tv, deep - 1, lock);
2975 	    }
2976 	    break;
2977 	case VAR_DICT:
2978 	    if ((d = tv->vval.v_dict) != NULL)
2979 	    {
2980 		if (lock)
2981 		    d->dv_lock |= VAR_LOCKED;
2982 		else
2983 		    d->dv_lock &= ~VAR_LOCKED;
2984 		if (deep < 0 || deep > 1)
2985 		{
2986 		    /* recursive: lock/unlock the items the List contains */
2987 		    todo = (int)d->dv_hashtab.ht_used;
2988 		    for (hi = d->dv_hashtab.ht_array; todo > 0; ++hi)
2989 		    {
2990 			if (!HASHITEM_EMPTY(hi))
2991 			{
2992 			    --todo;
2993 			    item_lock(&HI2DI(hi)->di_tv, deep - 1, lock);
2994 			}
2995 		    }
2996 		}
2997 	    }
2998     }
2999     --recurse;
3000 }
3001 
3002 #if (defined(FEAT_MENU) && defined(FEAT_MULTI_LANG)) || defined(PROTO)
3003 /*
3004  * Delete all "menutrans_" variables.
3005  */
3006     void
3007 del_menutrans_vars(void)
3008 {
3009     hashitem_T	*hi;
3010     int		todo;
3011 
3012     hash_lock(&globvarht);
3013     todo = (int)globvarht.ht_used;
3014     for (hi = globvarht.ht_array; todo > 0 && !got_int; ++hi)
3015     {
3016 	if (!HASHITEM_EMPTY(hi))
3017 	{
3018 	    --todo;
3019 	    if (STRNCMP(HI2DI(hi)->di_key, "menutrans_", 10) == 0)
3020 		delete_var(&globvarht, hi);
3021 	}
3022     }
3023     hash_unlock(&globvarht);
3024 }
3025 #endif
3026 
3027 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
3028 
3029 /*
3030  * Local string buffer for the next two functions to store a variable name
3031  * with its prefix. Allocated in cat_prefix_varname(), freed later in
3032  * get_user_var_name().
3033  */
3034 
3035 static char_u *cat_prefix_varname(int prefix, char_u *name);
3036 
3037 static char_u	*varnamebuf = NULL;
3038 static int	varnamebuflen = 0;
3039 
3040 /*
3041  * Function to concatenate a prefix and a variable name.
3042  */
3043     static char_u *
3044 cat_prefix_varname(int prefix, char_u *name)
3045 {
3046     int		len;
3047 
3048     len = (int)STRLEN(name) + 3;
3049     if (len > varnamebuflen)
3050     {
3051 	vim_free(varnamebuf);
3052 	len += 10;			/* some additional space */
3053 	varnamebuf = alloc(len);
3054 	if (varnamebuf == NULL)
3055 	{
3056 	    varnamebuflen = 0;
3057 	    return NULL;
3058 	}
3059 	varnamebuflen = len;
3060     }
3061     *varnamebuf = prefix;
3062     varnamebuf[1] = ':';
3063     STRCPY(varnamebuf + 2, name);
3064     return varnamebuf;
3065 }
3066 
3067 /*
3068  * Function given to ExpandGeneric() to obtain the list of user defined
3069  * (global/buffer/window/built-in) variable names.
3070  */
3071     char_u *
3072 get_user_var_name(expand_T *xp, int idx)
3073 {
3074     static long_u	gdone;
3075     static long_u	bdone;
3076     static long_u	wdone;
3077 #ifdef FEAT_WINDOWS
3078     static long_u	tdone;
3079 #endif
3080     static int		vidx;
3081     static hashitem_T	*hi;
3082     hashtab_T		*ht;
3083 
3084     if (idx == 0)
3085     {
3086 	gdone = bdone = wdone = vidx = 0;
3087 #ifdef FEAT_WINDOWS
3088 	tdone = 0;
3089 #endif
3090     }
3091 
3092     /* Global variables */
3093     if (gdone < globvarht.ht_used)
3094     {
3095 	if (gdone++ == 0)
3096 	    hi = globvarht.ht_array;
3097 	else
3098 	    ++hi;
3099 	while (HASHITEM_EMPTY(hi))
3100 	    ++hi;
3101 	if (STRNCMP("g:", xp->xp_pattern, 2) == 0)
3102 	    return cat_prefix_varname('g', hi->hi_key);
3103 	return hi->hi_key;
3104     }
3105 
3106     /* b: variables */
3107     ht = &curbuf->b_vars->dv_hashtab;
3108     if (bdone < ht->ht_used)
3109     {
3110 	if (bdone++ == 0)
3111 	    hi = ht->ht_array;
3112 	else
3113 	    ++hi;
3114 	while (HASHITEM_EMPTY(hi))
3115 	    ++hi;
3116 	return cat_prefix_varname('b', hi->hi_key);
3117     }
3118     if (bdone == ht->ht_used)
3119     {
3120 	++bdone;
3121 	return (char_u *)"b:changedtick";
3122     }
3123 
3124     /* w: variables */
3125     ht = &curwin->w_vars->dv_hashtab;
3126     if (wdone < ht->ht_used)
3127     {
3128 	if (wdone++ == 0)
3129 	    hi = ht->ht_array;
3130 	else
3131 	    ++hi;
3132 	while (HASHITEM_EMPTY(hi))
3133 	    ++hi;
3134 	return cat_prefix_varname('w', hi->hi_key);
3135     }
3136 
3137 #ifdef FEAT_WINDOWS
3138     /* t: variables */
3139     ht = &curtab->tp_vars->dv_hashtab;
3140     if (tdone < ht->ht_used)
3141     {
3142 	if (tdone++ == 0)
3143 	    hi = ht->ht_array;
3144 	else
3145 	    ++hi;
3146 	while (HASHITEM_EMPTY(hi))
3147 	    ++hi;
3148 	return cat_prefix_varname('t', hi->hi_key);
3149     }
3150 #endif
3151 
3152     /* v: variables */
3153     if (vidx < VV_LEN)
3154 	return cat_prefix_varname('v', (char_u *)vimvars[vidx++].vv_name);
3155 
3156     vim_free(varnamebuf);
3157     varnamebuf = NULL;
3158     varnamebuflen = 0;
3159     return NULL;
3160 }
3161 
3162 #endif /* FEAT_CMDL_COMPL */
3163 
3164 /*
3165  * Return TRUE if "pat" matches "text".
3166  * Does not use 'cpo' and always uses 'magic'.
3167  */
3168     static int
3169 pattern_match(char_u *pat, char_u *text, int ic)
3170 {
3171     int		matches = FALSE;
3172     char_u	*save_cpo;
3173     regmatch_T	regmatch;
3174 
3175     /* avoid 'l' flag in 'cpoptions' */
3176     save_cpo = p_cpo;
3177     p_cpo = (char_u *)"";
3178     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
3179     if (regmatch.regprog != NULL)
3180     {
3181 	regmatch.rm_ic = ic;
3182 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
3183 	vim_regfree(regmatch.regprog);
3184     }
3185     p_cpo = save_cpo;
3186     return matches;
3187 }
3188 
3189 /*
3190  * types for expressions.
3191  */
3192 typedef enum
3193 {
3194     TYPE_UNKNOWN = 0
3195     , TYPE_EQUAL	/* == */
3196     , TYPE_NEQUAL	/* != */
3197     , TYPE_GREATER	/* >  */
3198     , TYPE_GEQUAL	/* >= */
3199     , TYPE_SMALLER	/* <  */
3200     , TYPE_SEQUAL	/* <= */
3201     , TYPE_MATCH	/* =~ */
3202     , TYPE_NOMATCH	/* !~ */
3203 } exptype_T;
3204 
3205 /*
3206  * The "evaluate" argument: When FALSE, the argument is only parsed but not
3207  * executed.  The function may return OK, but the rettv will be of type
3208  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
3209  */
3210 
3211 /*
3212  * Handle zero level expression.
3213  * This calls eval1() and handles error message and nextcmd.
3214  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
3215  * Note: "rettv.v_lock" is not set.
3216  * Return OK or FAIL.
3217  */
3218     int
3219 eval0(
3220     char_u	*arg,
3221     typval_T	*rettv,
3222     char_u	**nextcmd,
3223     int		evaluate)
3224 {
3225     int		ret;
3226     char_u	*p;
3227 
3228     p = skipwhite(arg);
3229     ret = eval1(&p, rettv, evaluate);
3230     if (ret == FAIL || !ends_excmd(*p))
3231     {
3232 	if (ret != FAIL)
3233 	    clear_tv(rettv);
3234 	/*
3235 	 * Report the invalid expression unless the expression evaluation has
3236 	 * been cancelled due to an aborting error, an interrupt, or an
3237 	 * exception.
3238 	 */
3239 	if (!aborting())
3240 	    EMSG2(_(e_invexpr2), arg);
3241 	ret = FAIL;
3242     }
3243     if (nextcmd != NULL)
3244 	*nextcmd = check_nextcmd(p);
3245 
3246     return ret;
3247 }
3248 
3249 /*
3250  * Handle top level expression:
3251  *	expr2 ? expr1 : expr1
3252  *
3253  * "arg" must point to the first non-white of the expression.
3254  * "arg" is advanced to the next non-white after the recognized expression.
3255  *
3256  * Note: "rettv.v_lock" is not set.
3257  *
3258  * Return OK or FAIL.
3259  */
3260     int
3261 eval1(char_u **arg, typval_T *rettv, int evaluate)
3262 {
3263     int		result;
3264     typval_T	var2;
3265 
3266     /*
3267      * Get the first variable.
3268      */
3269     if (eval2(arg, rettv, evaluate) == FAIL)
3270 	return FAIL;
3271 
3272     if ((*arg)[0] == '?')
3273     {
3274 	result = FALSE;
3275 	if (evaluate)
3276 	{
3277 	    int		error = FALSE;
3278 
3279 	    if (get_tv_number_chk(rettv, &error) != 0)
3280 		result = TRUE;
3281 	    clear_tv(rettv);
3282 	    if (error)
3283 		return FAIL;
3284 	}
3285 
3286 	/*
3287 	 * Get the second variable.
3288 	 */
3289 	*arg = skipwhite(*arg + 1);
3290 	if (eval1(arg, rettv, evaluate && result) == FAIL) /* recursive! */
3291 	    return FAIL;
3292 
3293 	/*
3294 	 * Check for the ":".
3295 	 */
3296 	if ((*arg)[0] != ':')
3297 	{
3298 	    EMSG(_("E109: Missing ':' after '?'"));
3299 	    if (evaluate && result)
3300 		clear_tv(rettv);
3301 	    return FAIL;
3302 	}
3303 
3304 	/*
3305 	 * Get the third variable.
3306 	 */
3307 	*arg = skipwhite(*arg + 1);
3308 	if (eval1(arg, &var2, evaluate && !result) == FAIL) /* recursive! */
3309 	{
3310 	    if (evaluate && result)
3311 		clear_tv(rettv);
3312 	    return FAIL;
3313 	}
3314 	if (evaluate && !result)
3315 	    *rettv = var2;
3316     }
3317 
3318     return OK;
3319 }
3320 
3321 /*
3322  * Handle first level expression:
3323  *	expr2 || expr2 || expr2	    logical OR
3324  *
3325  * "arg" must point to the first non-white of the expression.
3326  * "arg" is advanced to the next non-white after the recognized expression.
3327  *
3328  * Return OK or FAIL.
3329  */
3330     static int
3331 eval2(char_u **arg, typval_T *rettv, int evaluate)
3332 {
3333     typval_T	var2;
3334     long	result;
3335     int		first;
3336     int		error = FALSE;
3337 
3338     /*
3339      * Get the first variable.
3340      */
3341     if (eval3(arg, rettv, evaluate) == FAIL)
3342 	return FAIL;
3343 
3344     /*
3345      * Repeat until there is no following "||".
3346      */
3347     first = TRUE;
3348     result = FALSE;
3349     while ((*arg)[0] == '|' && (*arg)[1] == '|')
3350     {
3351 	if (evaluate && first)
3352 	{
3353 	    if (get_tv_number_chk(rettv, &error) != 0)
3354 		result = TRUE;
3355 	    clear_tv(rettv);
3356 	    if (error)
3357 		return FAIL;
3358 	    first = FALSE;
3359 	}
3360 
3361 	/*
3362 	 * Get the second variable.
3363 	 */
3364 	*arg = skipwhite(*arg + 2);
3365 	if (eval3(arg, &var2, evaluate && !result) == FAIL)
3366 	    return FAIL;
3367 
3368 	/*
3369 	 * Compute the result.
3370 	 */
3371 	if (evaluate && !result)
3372 	{
3373 	    if (get_tv_number_chk(&var2, &error) != 0)
3374 		result = TRUE;
3375 	    clear_tv(&var2);
3376 	    if (error)
3377 		return FAIL;
3378 	}
3379 	if (evaluate)
3380 	{
3381 	    rettv->v_type = VAR_NUMBER;
3382 	    rettv->vval.v_number = result;
3383 	}
3384     }
3385 
3386     return OK;
3387 }
3388 
3389 /*
3390  * Handle second level expression:
3391  *	expr3 && expr3 && expr3	    logical AND
3392  *
3393  * "arg" must point to the first non-white of the expression.
3394  * "arg" is advanced to the next non-white after the recognized expression.
3395  *
3396  * Return OK or FAIL.
3397  */
3398     static int
3399 eval3(char_u **arg, typval_T *rettv, int evaluate)
3400 {
3401     typval_T	var2;
3402     long	result;
3403     int		first;
3404     int		error = FALSE;
3405 
3406     /*
3407      * Get the first variable.
3408      */
3409     if (eval4(arg, rettv, evaluate) == FAIL)
3410 	return FAIL;
3411 
3412     /*
3413      * Repeat until there is no following "&&".
3414      */
3415     first = TRUE;
3416     result = TRUE;
3417     while ((*arg)[0] == '&' && (*arg)[1] == '&')
3418     {
3419 	if (evaluate && first)
3420 	{
3421 	    if (get_tv_number_chk(rettv, &error) == 0)
3422 		result = FALSE;
3423 	    clear_tv(rettv);
3424 	    if (error)
3425 		return FAIL;
3426 	    first = FALSE;
3427 	}
3428 
3429 	/*
3430 	 * Get the second variable.
3431 	 */
3432 	*arg = skipwhite(*arg + 2);
3433 	if (eval4(arg, &var2, evaluate && result) == FAIL)
3434 	    return FAIL;
3435 
3436 	/*
3437 	 * Compute the result.
3438 	 */
3439 	if (evaluate && result)
3440 	{
3441 	    if (get_tv_number_chk(&var2, &error) == 0)
3442 		result = FALSE;
3443 	    clear_tv(&var2);
3444 	    if (error)
3445 		return FAIL;
3446 	}
3447 	if (evaluate)
3448 	{
3449 	    rettv->v_type = VAR_NUMBER;
3450 	    rettv->vval.v_number = result;
3451 	}
3452     }
3453 
3454     return OK;
3455 }
3456 
3457 /*
3458  * Handle third level expression:
3459  *	var1 == var2
3460  *	var1 =~ var2
3461  *	var1 != var2
3462  *	var1 !~ var2
3463  *	var1 > var2
3464  *	var1 >= var2
3465  *	var1 < var2
3466  *	var1 <= var2
3467  *	var1 is var2
3468  *	var1 isnot var2
3469  *
3470  * "arg" must point to the first non-white of the expression.
3471  * "arg" is advanced to the next non-white after the recognized expression.
3472  *
3473  * Return OK or FAIL.
3474  */
3475     static int
3476 eval4(char_u **arg, typval_T *rettv, int evaluate)
3477 {
3478     typval_T	var2;
3479     char_u	*p;
3480     int		i;
3481     exptype_T	type = TYPE_UNKNOWN;
3482     int		type_is = FALSE;    /* TRUE for "is" and "isnot" */
3483     int		len = 2;
3484     varnumber_T	n1, n2;
3485     char_u	*s1, *s2;
3486     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3487     int		ic;
3488 
3489     /*
3490      * Get the first variable.
3491      */
3492     if (eval5(arg, rettv, evaluate) == FAIL)
3493 	return FAIL;
3494 
3495     p = *arg;
3496     switch (p[0])
3497     {
3498 	case '=':   if (p[1] == '=')
3499 			type = TYPE_EQUAL;
3500 		    else if (p[1] == '~')
3501 			type = TYPE_MATCH;
3502 		    break;
3503 	case '!':   if (p[1] == '=')
3504 			type = TYPE_NEQUAL;
3505 		    else if (p[1] == '~')
3506 			type = TYPE_NOMATCH;
3507 		    break;
3508 	case '>':   if (p[1] != '=')
3509 		    {
3510 			type = TYPE_GREATER;
3511 			len = 1;
3512 		    }
3513 		    else
3514 			type = TYPE_GEQUAL;
3515 		    break;
3516 	case '<':   if (p[1] != '=')
3517 		    {
3518 			type = TYPE_SMALLER;
3519 			len = 1;
3520 		    }
3521 		    else
3522 			type = TYPE_SEQUAL;
3523 		    break;
3524 	case 'i':   if (p[1] == 's')
3525 		    {
3526 			if (p[2] == 'n' && p[3] == 'o' && p[4] == 't')
3527 			    len = 5;
3528 			i = p[len];
3529 			if (!isalnum(i) && i != '_')
3530 			{
3531 			    type = len == 2 ? TYPE_EQUAL : TYPE_NEQUAL;
3532 			    type_is = TRUE;
3533 			}
3534 		    }
3535 		    break;
3536     }
3537 
3538     /*
3539      * If there is a comparative operator, use it.
3540      */
3541     if (type != TYPE_UNKNOWN)
3542     {
3543 	/* extra question mark appended: ignore case */
3544 	if (p[len] == '?')
3545 	{
3546 	    ic = TRUE;
3547 	    ++len;
3548 	}
3549 	/* extra '#' appended: match case */
3550 	else if (p[len] == '#')
3551 	{
3552 	    ic = FALSE;
3553 	    ++len;
3554 	}
3555 	/* nothing appended: use 'ignorecase' */
3556 	else
3557 	    ic = p_ic;
3558 
3559 	/*
3560 	 * Get the second variable.
3561 	 */
3562 	*arg = skipwhite(p + len);
3563 	if (eval5(arg, &var2, evaluate) == FAIL)
3564 	{
3565 	    clear_tv(rettv);
3566 	    return FAIL;
3567 	}
3568 
3569 	if (evaluate)
3570 	{
3571 	    if (type_is && rettv->v_type != var2.v_type)
3572 	    {
3573 		/* For "is" a different type always means FALSE, for "notis"
3574 		 * it means TRUE. */
3575 		n1 = (type == TYPE_NEQUAL);
3576 	    }
3577 	    else if (rettv->v_type == VAR_LIST || var2.v_type == VAR_LIST)
3578 	    {
3579 		if (type_is)
3580 		{
3581 		    n1 = (rettv->v_type == var2.v_type
3582 				   && rettv->vval.v_list == var2.vval.v_list);
3583 		    if (type == TYPE_NEQUAL)
3584 			n1 = !n1;
3585 		}
3586 		else if (rettv->v_type != var2.v_type
3587 			|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
3588 		{
3589 		    if (rettv->v_type != var2.v_type)
3590 			EMSG(_("E691: Can only compare List with List"));
3591 		    else
3592 			EMSG(_("E692: Invalid operation for List"));
3593 		    clear_tv(rettv);
3594 		    clear_tv(&var2);
3595 		    return FAIL;
3596 		}
3597 		else
3598 		{
3599 		    /* Compare two Lists for being equal or unequal. */
3600 		    n1 = list_equal(rettv->vval.v_list, var2.vval.v_list,
3601 								   ic, FALSE);
3602 		    if (type == TYPE_NEQUAL)
3603 			n1 = !n1;
3604 		}
3605 	    }
3606 
3607 	    else if (rettv->v_type == VAR_DICT || var2.v_type == VAR_DICT)
3608 	    {
3609 		if (type_is)
3610 		{
3611 		    n1 = (rettv->v_type == var2.v_type
3612 				   && rettv->vval.v_dict == var2.vval.v_dict);
3613 		    if (type == TYPE_NEQUAL)
3614 			n1 = !n1;
3615 		}
3616 		else if (rettv->v_type != var2.v_type
3617 			|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
3618 		{
3619 		    if (rettv->v_type != var2.v_type)
3620 			EMSG(_("E735: Can only compare Dictionary with Dictionary"));
3621 		    else
3622 			EMSG(_("E736: Invalid operation for Dictionary"));
3623 		    clear_tv(rettv);
3624 		    clear_tv(&var2);
3625 		    return FAIL;
3626 		}
3627 		else
3628 		{
3629 		    /* Compare two Dictionaries for being equal or unequal. */
3630 		    n1 = dict_equal(rettv->vval.v_dict, var2.vval.v_dict,
3631 								   ic, FALSE);
3632 		    if (type == TYPE_NEQUAL)
3633 			n1 = !n1;
3634 		}
3635 	    }
3636 
3637 	    else if (rettv->v_type == VAR_FUNC || var2.v_type == VAR_FUNC
3638 		|| rettv->v_type == VAR_PARTIAL || var2.v_type == VAR_PARTIAL)
3639 	    {
3640 		if (type != TYPE_EQUAL && type != TYPE_NEQUAL)
3641 		{
3642 		    EMSG(_("E694: Invalid operation for Funcrefs"));
3643 		    clear_tv(rettv);
3644 		    clear_tv(&var2);
3645 		    return FAIL;
3646 		}
3647 		if ((rettv->v_type == VAR_PARTIAL
3648 					     && rettv->vval.v_partial == NULL)
3649 			|| (var2.v_type == VAR_PARTIAL
3650 					      && var2.vval.v_partial == NULL))
3651 		    /* when a partial is NULL assume not equal */
3652 		    n1 = FALSE;
3653 		else if (type_is)
3654 		{
3655 		    if (rettv->v_type == VAR_FUNC && var2.v_type == VAR_FUNC)
3656 			/* strings are considered the same if their value is
3657 			 * the same */
3658 			n1 = tv_equal(rettv, &var2, ic, FALSE);
3659 		    else if (rettv->v_type == VAR_PARTIAL
3660 						&& var2.v_type == VAR_PARTIAL)
3661 			n1 = (rettv->vval.v_partial == var2.vval.v_partial);
3662 		    else
3663 			n1 = FALSE;
3664 		}
3665 		else
3666 		    n1 = tv_equal(rettv, &var2, ic, FALSE);
3667 		if (type == TYPE_NEQUAL)
3668 		    n1 = !n1;
3669 	    }
3670 
3671 #ifdef FEAT_FLOAT
3672 	    /*
3673 	     * If one of the two variables is a float, compare as a float.
3674 	     * When using "=~" or "!~", always compare as string.
3675 	     */
3676 	    else if ((rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3677 		    && type != TYPE_MATCH && type != TYPE_NOMATCH)
3678 	    {
3679 		float_T f1, f2;
3680 
3681 		if (rettv->v_type == VAR_FLOAT)
3682 		    f1 = rettv->vval.v_float;
3683 		else
3684 		    f1 = get_tv_number(rettv);
3685 		if (var2.v_type == VAR_FLOAT)
3686 		    f2 = var2.vval.v_float;
3687 		else
3688 		    f2 = get_tv_number(&var2);
3689 		n1 = FALSE;
3690 		switch (type)
3691 		{
3692 		    case TYPE_EQUAL:    n1 = (f1 == f2); break;
3693 		    case TYPE_NEQUAL:   n1 = (f1 != f2); break;
3694 		    case TYPE_GREATER:  n1 = (f1 > f2); break;
3695 		    case TYPE_GEQUAL:   n1 = (f1 >= f2); break;
3696 		    case TYPE_SMALLER:  n1 = (f1 < f2); break;
3697 		    case TYPE_SEQUAL:   n1 = (f1 <= f2); break;
3698 		    case TYPE_UNKNOWN:
3699 		    case TYPE_MATCH:
3700 		    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
3701 		}
3702 	    }
3703 #endif
3704 
3705 	    /*
3706 	     * If one of the two variables is a number, compare as a number.
3707 	     * When using "=~" or "!~", always compare as string.
3708 	     */
3709 	    else if ((rettv->v_type == VAR_NUMBER || var2.v_type == VAR_NUMBER)
3710 		    && type != TYPE_MATCH && type != TYPE_NOMATCH)
3711 	    {
3712 		n1 = get_tv_number(rettv);
3713 		n2 = get_tv_number(&var2);
3714 		switch (type)
3715 		{
3716 		    case TYPE_EQUAL:    n1 = (n1 == n2); break;
3717 		    case TYPE_NEQUAL:   n1 = (n1 != n2); break;
3718 		    case TYPE_GREATER:  n1 = (n1 > n2); break;
3719 		    case TYPE_GEQUAL:   n1 = (n1 >= n2); break;
3720 		    case TYPE_SMALLER:  n1 = (n1 < n2); break;
3721 		    case TYPE_SEQUAL:   n1 = (n1 <= n2); break;
3722 		    case TYPE_UNKNOWN:
3723 		    case TYPE_MATCH:
3724 		    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
3725 		}
3726 	    }
3727 	    else
3728 	    {
3729 		s1 = get_tv_string_buf(rettv, buf1);
3730 		s2 = get_tv_string_buf(&var2, buf2);
3731 		if (type != TYPE_MATCH && type != TYPE_NOMATCH)
3732 		    i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
3733 		else
3734 		    i = 0;
3735 		n1 = FALSE;
3736 		switch (type)
3737 		{
3738 		    case TYPE_EQUAL:    n1 = (i == 0); break;
3739 		    case TYPE_NEQUAL:   n1 = (i != 0); break;
3740 		    case TYPE_GREATER:  n1 = (i > 0); break;
3741 		    case TYPE_GEQUAL:   n1 = (i >= 0); break;
3742 		    case TYPE_SMALLER:  n1 = (i < 0); break;
3743 		    case TYPE_SEQUAL:   n1 = (i <= 0); break;
3744 
3745 		    case TYPE_MATCH:
3746 		    case TYPE_NOMATCH:
3747 			    n1 = pattern_match(s2, s1, ic);
3748 			    if (type == TYPE_NOMATCH)
3749 				n1 = !n1;
3750 			    break;
3751 
3752 		    case TYPE_UNKNOWN:  break;  /* avoid gcc warning */
3753 		}
3754 	    }
3755 	    clear_tv(rettv);
3756 	    clear_tv(&var2);
3757 	    rettv->v_type = VAR_NUMBER;
3758 	    rettv->vval.v_number = n1;
3759 	}
3760     }
3761 
3762     return OK;
3763 }
3764 
3765 /*
3766  * Handle fourth level expression:
3767  *	+	number addition
3768  *	-	number subtraction
3769  *	.	string concatenation
3770  *
3771  * "arg" must point to the first non-white of the expression.
3772  * "arg" is advanced to the next non-white after the recognized expression.
3773  *
3774  * Return OK or FAIL.
3775  */
3776     static int
3777 eval5(char_u **arg, typval_T *rettv, int evaluate)
3778 {
3779     typval_T	var2;
3780     typval_T	var3;
3781     int		op;
3782     varnumber_T	n1, n2;
3783 #ifdef FEAT_FLOAT
3784     float_T	f1 = 0, f2 = 0;
3785 #endif
3786     char_u	*s1, *s2;
3787     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3788     char_u	*p;
3789 
3790     /*
3791      * Get the first variable.
3792      */
3793     if (eval6(arg, rettv, evaluate, FALSE) == FAIL)
3794 	return FAIL;
3795 
3796     /*
3797      * Repeat computing, until no '+', '-' or '.' is following.
3798      */
3799     for (;;)
3800     {
3801 	op = **arg;
3802 	if (op != '+' && op != '-' && op != '.')
3803 	    break;
3804 
3805 	if ((op != '+' || rettv->v_type != VAR_LIST)
3806 #ifdef FEAT_FLOAT
3807 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
3808 #endif
3809 		)
3810 	{
3811 	    /* For "list + ...", an illegal use of the first operand as
3812 	     * a number cannot be determined before evaluating the 2nd
3813 	     * operand: if this is also a list, all is ok.
3814 	     * For "something . ...", "something - ..." or "non-list + ...",
3815 	     * we know that the first operand needs to be a string or number
3816 	     * without evaluating the 2nd operand.  So check before to avoid
3817 	     * side effects after an error. */
3818 	    if (evaluate && get_tv_string_chk(rettv) == NULL)
3819 	    {
3820 		clear_tv(rettv);
3821 		return FAIL;
3822 	    }
3823 	}
3824 
3825 	/*
3826 	 * Get the second variable.
3827 	 */
3828 	*arg = skipwhite(*arg + 1);
3829 	if (eval6(arg, &var2, evaluate, op == '.') == FAIL)
3830 	{
3831 	    clear_tv(rettv);
3832 	    return FAIL;
3833 	}
3834 
3835 	if (evaluate)
3836 	{
3837 	    /*
3838 	     * Compute the result.
3839 	     */
3840 	    if (op == '.')
3841 	    {
3842 		s1 = get_tv_string_buf(rettv, buf1);	/* already checked */
3843 		s2 = get_tv_string_buf_chk(&var2, buf2);
3844 		if (s2 == NULL)		/* type error ? */
3845 		{
3846 		    clear_tv(rettv);
3847 		    clear_tv(&var2);
3848 		    return FAIL;
3849 		}
3850 		p = concat_str(s1, s2);
3851 		clear_tv(rettv);
3852 		rettv->v_type = VAR_STRING;
3853 		rettv->vval.v_string = p;
3854 	    }
3855 	    else if (op == '+' && rettv->v_type == VAR_LIST
3856 						   && var2.v_type == VAR_LIST)
3857 	    {
3858 		/* concatenate Lists */
3859 		if (list_concat(rettv->vval.v_list, var2.vval.v_list,
3860 							       &var3) == FAIL)
3861 		{
3862 		    clear_tv(rettv);
3863 		    clear_tv(&var2);
3864 		    return FAIL;
3865 		}
3866 		clear_tv(rettv);
3867 		*rettv = var3;
3868 	    }
3869 	    else
3870 	    {
3871 		int	    error = FALSE;
3872 
3873 #ifdef FEAT_FLOAT
3874 		if (rettv->v_type == VAR_FLOAT)
3875 		{
3876 		    f1 = rettv->vval.v_float;
3877 		    n1 = 0;
3878 		}
3879 		else
3880 #endif
3881 		{
3882 		    n1 = get_tv_number_chk(rettv, &error);
3883 		    if (error)
3884 		    {
3885 			/* This can only happen for "list + non-list".  For
3886 			 * "non-list + ..." or "something - ...", we returned
3887 			 * before evaluating the 2nd operand. */
3888 			clear_tv(rettv);
3889 			return FAIL;
3890 		    }
3891 #ifdef FEAT_FLOAT
3892 		    if (var2.v_type == VAR_FLOAT)
3893 			f1 = n1;
3894 #endif
3895 		}
3896 #ifdef FEAT_FLOAT
3897 		if (var2.v_type == VAR_FLOAT)
3898 		{
3899 		    f2 = var2.vval.v_float;
3900 		    n2 = 0;
3901 		}
3902 		else
3903 #endif
3904 		{
3905 		    n2 = get_tv_number_chk(&var2, &error);
3906 		    if (error)
3907 		    {
3908 			clear_tv(rettv);
3909 			clear_tv(&var2);
3910 			return FAIL;
3911 		    }
3912 #ifdef FEAT_FLOAT
3913 		    if (rettv->v_type == VAR_FLOAT)
3914 			f2 = n2;
3915 #endif
3916 		}
3917 		clear_tv(rettv);
3918 
3919 #ifdef FEAT_FLOAT
3920 		/* If there is a float on either side the result is a float. */
3921 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3922 		{
3923 		    if (op == '+')
3924 			f1 = f1 + f2;
3925 		    else
3926 			f1 = f1 - f2;
3927 		    rettv->v_type = VAR_FLOAT;
3928 		    rettv->vval.v_float = f1;
3929 		}
3930 		else
3931 #endif
3932 		{
3933 		    if (op == '+')
3934 			n1 = n1 + n2;
3935 		    else
3936 			n1 = n1 - n2;
3937 		    rettv->v_type = VAR_NUMBER;
3938 		    rettv->vval.v_number = n1;
3939 		}
3940 	    }
3941 	    clear_tv(&var2);
3942 	}
3943     }
3944     return OK;
3945 }
3946 
3947 /*
3948  * Handle fifth level expression:
3949  *	*	number multiplication
3950  *	/	number division
3951  *	%	number modulo
3952  *
3953  * "arg" must point to the first non-white of the expression.
3954  * "arg" is advanced to the next non-white after the recognized expression.
3955  *
3956  * Return OK or FAIL.
3957  */
3958     static int
3959 eval6(
3960     char_u	**arg,
3961     typval_T	*rettv,
3962     int		evaluate,
3963     int		want_string)  /* after "." operator */
3964 {
3965     typval_T	var2;
3966     int		op;
3967     varnumber_T	n1, n2;
3968 #ifdef FEAT_FLOAT
3969     int		use_float = FALSE;
3970     float_T	f1 = 0, f2;
3971 #endif
3972     int		error = FALSE;
3973 
3974     /*
3975      * Get the first variable.
3976      */
3977     if (eval7(arg, rettv, evaluate, want_string) == FAIL)
3978 	return FAIL;
3979 
3980     /*
3981      * Repeat computing, until no '*', '/' or '%' is following.
3982      */
3983     for (;;)
3984     {
3985 	op = **arg;
3986 	if (op != '*' && op != '/' && op != '%')
3987 	    break;
3988 
3989 	if (evaluate)
3990 	{
3991 #ifdef FEAT_FLOAT
3992 	    if (rettv->v_type == VAR_FLOAT)
3993 	    {
3994 		f1 = rettv->vval.v_float;
3995 		use_float = TRUE;
3996 		n1 = 0;
3997 	    }
3998 	    else
3999 #endif
4000 		n1 = get_tv_number_chk(rettv, &error);
4001 	    clear_tv(rettv);
4002 	    if (error)
4003 		return FAIL;
4004 	}
4005 	else
4006 	    n1 = 0;
4007 
4008 	/*
4009 	 * Get the second variable.
4010 	 */
4011 	*arg = skipwhite(*arg + 1);
4012 	if (eval7(arg, &var2, evaluate, FALSE) == FAIL)
4013 	    return FAIL;
4014 
4015 	if (evaluate)
4016 	{
4017 #ifdef FEAT_FLOAT
4018 	    if (var2.v_type == VAR_FLOAT)
4019 	    {
4020 		if (!use_float)
4021 		{
4022 		    f1 = n1;
4023 		    use_float = TRUE;
4024 		}
4025 		f2 = var2.vval.v_float;
4026 		n2 = 0;
4027 	    }
4028 	    else
4029 #endif
4030 	    {
4031 		n2 = get_tv_number_chk(&var2, &error);
4032 		clear_tv(&var2);
4033 		if (error)
4034 		    return FAIL;
4035 #ifdef FEAT_FLOAT
4036 		if (use_float)
4037 		    f2 = n2;
4038 #endif
4039 	    }
4040 
4041 	    /*
4042 	     * Compute the result.
4043 	     * When either side is a float the result is a float.
4044 	     */
4045 #ifdef FEAT_FLOAT
4046 	    if (use_float)
4047 	    {
4048 		if (op == '*')
4049 		    f1 = f1 * f2;
4050 		else if (op == '/')
4051 		{
4052 # ifdef VMS
4053 		    /* VMS crashes on divide by zero, work around it */
4054 		    if (f2 == 0.0)
4055 		    {
4056 			if (f1 == 0)
4057 			    f1 = -1 * __F_FLT_MAX - 1L;   /* similar to NaN */
4058 			else if (f1 < 0)
4059 			    f1 = -1 * __F_FLT_MAX;
4060 			else
4061 			    f1 = __F_FLT_MAX;
4062 		    }
4063 		    else
4064 			f1 = f1 / f2;
4065 # else
4066 		    /* We rely on the floating point library to handle divide
4067 		     * by zero to result in "inf" and not a crash. */
4068 		    f1 = f1 / f2;
4069 # endif
4070 		}
4071 		else
4072 		{
4073 		    EMSG(_("E804: Cannot use '%' with Float"));
4074 		    return FAIL;
4075 		}
4076 		rettv->v_type = VAR_FLOAT;
4077 		rettv->vval.v_float = f1;
4078 	    }
4079 	    else
4080 #endif
4081 	    {
4082 		if (op == '*')
4083 		    n1 = n1 * n2;
4084 		else if (op == '/')
4085 		{
4086 		    if (n2 == 0)	/* give an error message? */
4087 		    {
4088 #ifdef FEAT_NUM64
4089 			if (n1 == 0)
4090 			    n1 = -0x7fffffffffffffffLL - 1; /* similar to NaN */
4091 			else if (n1 < 0)
4092 			    n1 = -0x7fffffffffffffffLL;
4093 			else
4094 			    n1 = 0x7fffffffffffffffLL;
4095 #else
4096 			if (n1 == 0)
4097 			    n1 = -0x7fffffffL - 1L;	/* similar to NaN */
4098 			else if (n1 < 0)
4099 			    n1 = -0x7fffffffL;
4100 			else
4101 			    n1 = 0x7fffffffL;
4102 #endif
4103 		    }
4104 		    else
4105 			n1 = n1 / n2;
4106 		}
4107 		else
4108 		{
4109 		    if (n2 == 0)	/* give an error message? */
4110 			n1 = 0;
4111 		    else
4112 			n1 = n1 % n2;
4113 		}
4114 		rettv->v_type = VAR_NUMBER;
4115 		rettv->vval.v_number = n1;
4116 	    }
4117 	}
4118     }
4119 
4120     return OK;
4121 }
4122 
4123 /*
4124  * Handle sixth level expression:
4125  *  number		number constant
4126  *  "string"		string constant
4127  *  'string'		literal string constant
4128  *  &option-name	option value
4129  *  @r			register contents
4130  *  identifier		variable value
4131  *  function()		function call
4132  *  $VAR		environment variable
4133  *  (expression)	nested expression
4134  *  [expr, expr]	List
4135  *  {key: val, key: val}  Dictionary
4136  *
4137  *  Also handle:
4138  *  ! in front		logical NOT
4139  *  - in front		unary minus
4140  *  + in front		unary plus (ignored)
4141  *  trailing []		subscript in String or List
4142  *  trailing .name	entry in Dictionary
4143  *
4144  * "arg" must point to the first non-white of the expression.
4145  * "arg" is advanced to the next non-white after the recognized expression.
4146  *
4147  * Return OK or FAIL.
4148  */
4149     static int
4150 eval7(
4151     char_u	**arg,
4152     typval_T	*rettv,
4153     int		evaluate,
4154     int		want_string UNUSED)	/* after "." operator */
4155 {
4156     varnumber_T	n;
4157     int		len;
4158     char_u	*s;
4159     char_u	*start_leader, *end_leader;
4160     int		ret = OK;
4161     char_u	*alias;
4162 
4163     /*
4164      * Initialise variable so that clear_tv() can't mistake this for a
4165      * string and free a string that isn't there.
4166      */
4167     rettv->v_type = VAR_UNKNOWN;
4168 
4169     /*
4170      * Skip '!', '-' and '+' characters.  They are handled later.
4171      */
4172     start_leader = *arg;
4173     while (**arg == '!' || **arg == '-' || **arg == '+')
4174 	*arg = skipwhite(*arg + 1);
4175     end_leader = *arg;
4176 
4177     switch (**arg)
4178     {
4179     /*
4180      * Number constant.
4181      */
4182     case '0':
4183     case '1':
4184     case '2':
4185     case '3':
4186     case '4':
4187     case '5':
4188     case '6':
4189     case '7':
4190     case '8':
4191     case '9':
4192 	{
4193 #ifdef FEAT_FLOAT
4194 		char_u *p = skipdigits(*arg + 1);
4195 		int    get_float = FALSE;
4196 
4197 		/* We accept a float when the format matches
4198 		 * "[0-9]\+\.[0-9]\+\([eE][+-]\?[0-9]\+\)\?".  This is very
4199 		 * strict to avoid backwards compatibility problems.
4200 		 * Don't look for a float after the "." operator, so that
4201 		 * ":let vers = 1.2.3" doesn't fail. */
4202 		if (!want_string && p[0] == '.' && vim_isdigit(p[1]))
4203 		{
4204 		    get_float = TRUE;
4205 		    p = skipdigits(p + 2);
4206 		    if (*p == 'e' || *p == 'E')
4207 		    {
4208 			++p;
4209 			if (*p == '-' || *p == '+')
4210 			    ++p;
4211 			if (!vim_isdigit(*p))
4212 			    get_float = FALSE;
4213 			else
4214 			    p = skipdigits(p + 1);
4215 		    }
4216 		    if (ASCII_ISALPHA(*p) || *p == '.')
4217 			get_float = FALSE;
4218 		}
4219 		if (get_float)
4220 		{
4221 		    float_T	f;
4222 
4223 		    *arg += string2float(*arg, &f);
4224 		    if (evaluate)
4225 		    {
4226 			rettv->v_type = VAR_FLOAT;
4227 			rettv->vval.v_float = f;
4228 		    }
4229 		}
4230 		else
4231 #endif
4232 		{
4233 		    vim_str2nr(*arg, NULL, &len, STR2NR_ALL, &n, NULL, 0);
4234 		    *arg += len;
4235 		    if (evaluate)
4236 		    {
4237 			rettv->v_type = VAR_NUMBER;
4238 			rettv->vval.v_number = n;
4239 		    }
4240 		}
4241 		break;
4242 	}
4243 
4244     /*
4245      * String constant: "string".
4246      */
4247     case '"':	ret = get_string_tv(arg, rettv, evaluate);
4248 		break;
4249 
4250     /*
4251      * Literal string constant: 'str''ing'.
4252      */
4253     case '\'':	ret = get_lit_string_tv(arg, rettv, evaluate);
4254 		break;
4255 
4256     /*
4257      * List: [expr, expr]
4258      */
4259     case '[':	ret = get_list_tv(arg, rettv, evaluate);
4260 		break;
4261 
4262     /*
4263      * Lambda: {arg, arg -> expr}
4264      * Dictionary: {key: val, key: val}
4265      */
4266     case '{':	ret = get_lambda_tv(arg, rettv, evaluate);
4267 		if (ret == NOTDONE)
4268 		    ret = get_dict_tv(arg, rettv, evaluate);
4269 		break;
4270 
4271     /*
4272      * Option value: &name
4273      */
4274     case '&':	ret = get_option_tv(arg, rettv, evaluate);
4275 		break;
4276 
4277     /*
4278      * Environment variable: $VAR.
4279      */
4280     case '$':	ret = get_env_tv(arg, rettv, evaluate);
4281 		break;
4282 
4283     /*
4284      * Register contents: @r.
4285      */
4286     case '@':	++*arg;
4287 		if (evaluate)
4288 		{
4289 		    rettv->v_type = VAR_STRING;
4290 		    rettv->vval.v_string = get_reg_contents(**arg,
4291 							    GREG_EXPR_SRC);
4292 		}
4293 		if (**arg != NUL)
4294 		    ++*arg;
4295 		break;
4296 
4297     /*
4298      * nested expression: (expression).
4299      */
4300     case '(':	*arg = skipwhite(*arg + 1);
4301 		ret = eval1(arg, rettv, evaluate);	/* recursive! */
4302 		if (**arg == ')')
4303 		    ++*arg;
4304 		else if (ret == OK)
4305 		{
4306 		    EMSG(_("E110: Missing ')'"));
4307 		    clear_tv(rettv);
4308 		    ret = FAIL;
4309 		}
4310 		break;
4311 
4312     default:	ret = NOTDONE;
4313 		break;
4314     }
4315 
4316     if (ret == NOTDONE)
4317     {
4318 	/*
4319 	 * Must be a variable or function name.
4320 	 * Can also be a curly-braces kind of name: {expr}.
4321 	 */
4322 	s = *arg;
4323 	len = get_name_len(arg, &alias, evaluate, TRUE);
4324 	if (alias != NULL)
4325 	    s = alias;
4326 
4327 	if (len <= 0)
4328 	    ret = FAIL;
4329 	else
4330 	{
4331 	    if (**arg == '(')		/* recursive! */
4332 	    {
4333 		partial_T *partial;
4334 
4335 		if (!evaluate)
4336 		    check_vars(s, len);
4337 
4338 		/* If "s" is the name of a variable of type VAR_FUNC
4339 		 * use its contents. */
4340 		s = deref_func_name(s, &len, &partial, !evaluate);
4341 
4342 		/* Need to make a copy, in case evaluating the arguments makes
4343 		 * the name invalid. */
4344 		s = vim_strsave(s);
4345 		if (s == NULL)
4346 		    ret = FAIL;
4347 		else
4348 		    /* Invoke the function. */
4349 		    ret = get_func_tv(s, len, rettv, arg,
4350 			      curwin->w_cursor.lnum, curwin->w_cursor.lnum,
4351 			      &len, evaluate, partial, NULL);
4352 		vim_free(s);
4353 
4354 		/* If evaluate is FALSE rettv->v_type was not set in
4355 		 * get_func_tv, but it's needed in handle_subscript() to parse
4356 		 * what follows. So set it here. */
4357 		if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
4358 		{
4359 		    rettv->vval.v_string = NULL;
4360 		    rettv->v_type = VAR_FUNC;
4361 		}
4362 
4363 		/* Stop the expression evaluation when immediately
4364 		 * aborting on error, or when an interrupt occurred or
4365 		 * an exception was thrown but not caught. */
4366 		if (aborting())
4367 		{
4368 		    if (ret == OK)
4369 			clear_tv(rettv);
4370 		    ret = FAIL;
4371 		}
4372 	    }
4373 	    else if (evaluate)
4374 		ret = get_var_tv(s, len, rettv, NULL, TRUE, FALSE);
4375 	    else
4376 	    {
4377 		check_vars(s, len);
4378 		ret = OK;
4379 	    }
4380 	}
4381 	vim_free(alias);
4382     }
4383 
4384     *arg = skipwhite(*arg);
4385 
4386     /* Handle following '[', '(' and '.' for expr[expr], expr.name,
4387      * expr(expr). */
4388     if (ret == OK)
4389 	ret = handle_subscript(arg, rettv, evaluate, TRUE);
4390 
4391     /*
4392      * Apply logical NOT and unary '-', from right to left, ignore '+'.
4393      */
4394     if (ret == OK && evaluate && end_leader > start_leader)
4395     {
4396 	int	    error = FALSE;
4397 	varnumber_T val = 0;
4398 #ifdef FEAT_FLOAT
4399 	float_T	    f = 0.0;
4400 
4401 	if (rettv->v_type == VAR_FLOAT)
4402 	    f = rettv->vval.v_float;
4403 	else
4404 #endif
4405 	    val = get_tv_number_chk(rettv, &error);
4406 	if (error)
4407 	{
4408 	    clear_tv(rettv);
4409 	    ret = FAIL;
4410 	}
4411 	else
4412 	{
4413 	    while (end_leader > start_leader)
4414 	    {
4415 		--end_leader;
4416 		if (*end_leader == '!')
4417 		{
4418 #ifdef FEAT_FLOAT
4419 		    if (rettv->v_type == VAR_FLOAT)
4420 			f = !f;
4421 		    else
4422 #endif
4423 			val = !val;
4424 		}
4425 		else if (*end_leader == '-')
4426 		{
4427 #ifdef FEAT_FLOAT
4428 		    if (rettv->v_type == VAR_FLOAT)
4429 			f = -f;
4430 		    else
4431 #endif
4432 			val = -val;
4433 		}
4434 	    }
4435 #ifdef FEAT_FLOAT
4436 	    if (rettv->v_type == VAR_FLOAT)
4437 	    {
4438 		clear_tv(rettv);
4439 		rettv->vval.v_float = f;
4440 	    }
4441 	    else
4442 #endif
4443 	    {
4444 		clear_tv(rettv);
4445 		rettv->v_type = VAR_NUMBER;
4446 		rettv->vval.v_number = val;
4447 	    }
4448 	}
4449     }
4450 
4451     return ret;
4452 }
4453 
4454 /*
4455  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
4456  * "*arg" points to the '[' or '.'.
4457  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
4458  */
4459     static int
4460 eval_index(
4461     char_u	**arg,
4462     typval_T	*rettv,
4463     int		evaluate,
4464     int		verbose)	/* give error messages */
4465 {
4466     int		empty1 = FALSE, empty2 = FALSE;
4467     typval_T	var1, var2;
4468     long	n1, n2 = 0;
4469     long	len = -1;
4470     int		range = FALSE;
4471     char_u	*s;
4472     char_u	*key = NULL;
4473 
4474     switch (rettv->v_type)
4475     {
4476 	case VAR_FUNC:
4477 	case VAR_PARTIAL:
4478 	    if (verbose)
4479 		EMSG(_("E695: Cannot index a Funcref"));
4480 	    return FAIL;
4481 	case VAR_FLOAT:
4482 #ifdef FEAT_FLOAT
4483 	    if (verbose)
4484 		EMSG(_(e_float_as_string));
4485 	    return FAIL;
4486 #endif
4487 	case VAR_SPECIAL:
4488 	case VAR_JOB:
4489 	case VAR_CHANNEL:
4490 	    if (verbose)
4491 		EMSG(_("E909: Cannot index a special variable"));
4492 	    return FAIL;
4493 	case VAR_UNKNOWN:
4494 	    if (evaluate)
4495 		return FAIL;
4496 	    /* FALLTHROUGH */
4497 
4498 	case VAR_STRING:
4499 	case VAR_NUMBER:
4500 	case VAR_LIST:
4501 	case VAR_DICT:
4502 	    break;
4503     }
4504 
4505     init_tv(&var1);
4506     init_tv(&var2);
4507     if (**arg == '.')
4508     {
4509 	/*
4510 	 * dict.name
4511 	 */
4512 	key = *arg + 1;
4513 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
4514 	    ;
4515 	if (len == 0)
4516 	    return FAIL;
4517 	*arg = skipwhite(key + len);
4518     }
4519     else
4520     {
4521 	/*
4522 	 * something[idx]
4523 	 *
4524 	 * Get the (first) variable from inside the [].
4525 	 */
4526 	*arg = skipwhite(*arg + 1);
4527 	if (**arg == ':')
4528 	    empty1 = TRUE;
4529 	else if (eval1(arg, &var1, evaluate) == FAIL)	/* recursive! */
4530 	    return FAIL;
4531 	else if (evaluate && get_tv_string_chk(&var1) == NULL)
4532 	{
4533 	    /* not a number or string */
4534 	    clear_tv(&var1);
4535 	    return FAIL;
4536 	}
4537 
4538 	/*
4539 	 * Get the second variable from inside the [:].
4540 	 */
4541 	if (**arg == ':')
4542 	{
4543 	    range = TRUE;
4544 	    *arg = skipwhite(*arg + 1);
4545 	    if (**arg == ']')
4546 		empty2 = TRUE;
4547 	    else if (eval1(arg, &var2, evaluate) == FAIL)	/* recursive! */
4548 	    {
4549 		if (!empty1)
4550 		    clear_tv(&var1);
4551 		return FAIL;
4552 	    }
4553 	    else if (evaluate && get_tv_string_chk(&var2) == NULL)
4554 	    {
4555 		/* not a number or string */
4556 		if (!empty1)
4557 		    clear_tv(&var1);
4558 		clear_tv(&var2);
4559 		return FAIL;
4560 	    }
4561 	}
4562 
4563 	/* Check for the ']'. */
4564 	if (**arg != ']')
4565 	{
4566 	    if (verbose)
4567 		EMSG(_(e_missbrac));
4568 	    clear_tv(&var1);
4569 	    if (range)
4570 		clear_tv(&var2);
4571 	    return FAIL;
4572 	}
4573 	*arg = skipwhite(*arg + 1);	/* skip the ']' */
4574     }
4575 
4576     if (evaluate)
4577     {
4578 	n1 = 0;
4579 	if (!empty1 && rettv->v_type != VAR_DICT)
4580 	{
4581 	    n1 = get_tv_number(&var1);
4582 	    clear_tv(&var1);
4583 	}
4584 	if (range)
4585 	{
4586 	    if (empty2)
4587 		n2 = -1;
4588 	    else
4589 	    {
4590 		n2 = get_tv_number(&var2);
4591 		clear_tv(&var2);
4592 	    }
4593 	}
4594 
4595 	switch (rettv->v_type)
4596 	{
4597 	    case VAR_UNKNOWN:
4598 	    case VAR_FUNC:
4599 	    case VAR_PARTIAL:
4600 	    case VAR_FLOAT:
4601 	    case VAR_SPECIAL:
4602 	    case VAR_JOB:
4603 	    case VAR_CHANNEL:
4604 		break; /* not evaluating, skipping over subscript */
4605 
4606 	    case VAR_NUMBER:
4607 	    case VAR_STRING:
4608 		s = get_tv_string(rettv);
4609 		len = (long)STRLEN(s);
4610 		if (range)
4611 		{
4612 		    /* The resulting variable is a substring.  If the indexes
4613 		     * are out of range the result is empty. */
4614 		    if (n1 < 0)
4615 		    {
4616 			n1 = len + n1;
4617 			if (n1 < 0)
4618 			    n1 = 0;
4619 		    }
4620 		    if (n2 < 0)
4621 			n2 = len + n2;
4622 		    else if (n2 >= len)
4623 			n2 = len;
4624 		    if (n1 >= len || n2 < 0 || n1 > n2)
4625 			s = NULL;
4626 		    else
4627 			s = vim_strnsave(s + n1, (int)(n2 - n1 + 1));
4628 		}
4629 		else
4630 		{
4631 		    /* The resulting variable is a string of a single
4632 		     * character.  If the index is too big or negative the
4633 		     * result is empty. */
4634 		    if (n1 >= len || n1 < 0)
4635 			s = NULL;
4636 		    else
4637 			s = vim_strnsave(s + n1, 1);
4638 		}
4639 		clear_tv(rettv);
4640 		rettv->v_type = VAR_STRING;
4641 		rettv->vval.v_string = s;
4642 		break;
4643 
4644 	    case VAR_LIST:
4645 		len = list_len(rettv->vval.v_list);
4646 		if (n1 < 0)
4647 		    n1 = len + n1;
4648 		if (!empty1 && (n1 < 0 || n1 >= len))
4649 		{
4650 		    /* For a range we allow invalid values and return an empty
4651 		     * list.  A list index out of range is an error. */
4652 		    if (!range)
4653 		    {
4654 			if (verbose)
4655 			    EMSGN(_(e_listidx), n1);
4656 			return FAIL;
4657 		    }
4658 		    n1 = len;
4659 		}
4660 		if (range)
4661 		{
4662 		    list_T	*l;
4663 		    listitem_T	*item;
4664 
4665 		    if (n2 < 0)
4666 			n2 = len + n2;
4667 		    else if (n2 >= len)
4668 			n2 = len - 1;
4669 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
4670 			n2 = -1;
4671 		    l = list_alloc();
4672 		    if (l == NULL)
4673 			return FAIL;
4674 		    for (item = list_find(rettv->vval.v_list, n1);
4675 							       n1 <= n2; ++n1)
4676 		    {
4677 			if (list_append_tv(l, &item->li_tv) == FAIL)
4678 			{
4679 			    list_free(l);
4680 			    return FAIL;
4681 			}
4682 			item = item->li_next;
4683 		    }
4684 		    clear_tv(rettv);
4685 		    rettv->v_type = VAR_LIST;
4686 		    rettv->vval.v_list = l;
4687 		    ++l->lv_refcount;
4688 		}
4689 		else
4690 		{
4691 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
4692 		    clear_tv(rettv);
4693 		    *rettv = var1;
4694 		}
4695 		break;
4696 
4697 	    case VAR_DICT:
4698 		if (range)
4699 		{
4700 		    if (verbose)
4701 			EMSG(_(e_dictrange));
4702 		    if (len == -1)
4703 			clear_tv(&var1);
4704 		    return FAIL;
4705 		}
4706 		{
4707 		    dictitem_T	*item;
4708 
4709 		    if (len == -1)
4710 		    {
4711 			key = get_tv_string_chk(&var1);
4712 			if (key == NULL)
4713 			{
4714 			    clear_tv(&var1);
4715 			    return FAIL;
4716 			}
4717 		    }
4718 
4719 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
4720 
4721 		    if (item == NULL && verbose)
4722 			EMSG2(_(e_dictkey), key);
4723 		    if (len == -1)
4724 			clear_tv(&var1);
4725 		    if (item == NULL)
4726 			return FAIL;
4727 
4728 		    copy_tv(&item->di_tv, &var1);
4729 		    clear_tv(rettv);
4730 		    *rettv = var1;
4731 		}
4732 		break;
4733 	}
4734     }
4735 
4736     return OK;
4737 }
4738 
4739 /*
4740  * Get an option value.
4741  * "arg" points to the '&' or '+' before the option name.
4742  * "arg" is advanced to character after the option name.
4743  * Return OK or FAIL.
4744  */
4745     int
4746 get_option_tv(
4747     char_u	**arg,
4748     typval_T	*rettv,	/* when NULL, only check if option exists */
4749     int		evaluate)
4750 {
4751     char_u	*option_end;
4752     long	numval;
4753     char_u	*stringval;
4754     int		opt_type;
4755     int		c;
4756     int		working = (**arg == '+');    /* has("+option") */
4757     int		ret = OK;
4758     int		opt_flags;
4759 
4760     /*
4761      * Isolate the option name and find its value.
4762      */
4763     option_end = find_option_end(arg, &opt_flags);
4764     if (option_end == NULL)
4765     {
4766 	if (rettv != NULL)
4767 	    EMSG2(_("E112: Option name missing: %s"), *arg);
4768 	return FAIL;
4769     }
4770 
4771     if (!evaluate)
4772     {
4773 	*arg = option_end;
4774 	return OK;
4775     }
4776 
4777     c = *option_end;
4778     *option_end = NUL;
4779     opt_type = get_option_value(*arg, &numval,
4780 			       rettv == NULL ? NULL : &stringval, opt_flags);
4781 
4782     if (opt_type == -3)			/* invalid name */
4783     {
4784 	if (rettv != NULL)
4785 	    EMSG2(_("E113: Unknown option: %s"), *arg);
4786 	ret = FAIL;
4787     }
4788     else if (rettv != NULL)
4789     {
4790 	if (opt_type == -2)		/* hidden string option */
4791 	{
4792 	    rettv->v_type = VAR_STRING;
4793 	    rettv->vval.v_string = NULL;
4794 	}
4795 	else if (opt_type == -1)	/* hidden number option */
4796 	{
4797 	    rettv->v_type = VAR_NUMBER;
4798 	    rettv->vval.v_number = 0;
4799 	}
4800 	else if (opt_type == 1)		/* number option */
4801 	{
4802 	    rettv->v_type = VAR_NUMBER;
4803 	    rettv->vval.v_number = numval;
4804 	}
4805 	else				/* string option */
4806 	{
4807 	    rettv->v_type = VAR_STRING;
4808 	    rettv->vval.v_string = stringval;
4809 	}
4810     }
4811     else if (working && (opt_type == -2 || opt_type == -1))
4812 	ret = FAIL;
4813 
4814     *option_end = c;		    /* put back for error messages */
4815     *arg = option_end;
4816 
4817     return ret;
4818 }
4819 
4820 /*
4821  * Allocate a variable for a string constant.
4822  * Return OK or FAIL.
4823  */
4824     static int
4825 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
4826 {
4827     char_u	*p;
4828     char_u	*name;
4829     int		extra = 0;
4830 
4831     /*
4832      * Find the end of the string, skipping backslashed characters.
4833      */
4834     for (p = *arg + 1; *p != NUL && *p != '"'; mb_ptr_adv(p))
4835     {
4836 	if (*p == '\\' && p[1] != NUL)
4837 	{
4838 	    ++p;
4839 	    /* A "\<x>" form occupies at least 4 characters, and produces up
4840 	     * to 6 characters: reserve space for 2 extra */
4841 	    if (*p == '<')
4842 		extra += 2;
4843 	}
4844     }
4845 
4846     if (*p != '"')
4847     {
4848 	EMSG2(_("E114: Missing quote: %s"), *arg);
4849 	return FAIL;
4850     }
4851 
4852     /* If only parsing, set *arg and return here */
4853     if (!evaluate)
4854     {
4855 	*arg = p + 1;
4856 	return OK;
4857     }
4858 
4859     /*
4860      * Copy the string into allocated memory, handling backslashed
4861      * characters.
4862      */
4863     name = alloc((unsigned)(p - *arg + extra));
4864     if (name == NULL)
4865 	return FAIL;
4866     rettv->v_type = VAR_STRING;
4867     rettv->vval.v_string = name;
4868 
4869     for (p = *arg + 1; *p != NUL && *p != '"'; )
4870     {
4871 	if (*p == '\\')
4872 	{
4873 	    switch (*++p)
4874 	    {
4875 		case 'b': *name++ = BS; ++p; break;
4876 		case 'e': *name++ = ESC; ++p; break;
4877 		case 'f': *name++ = FF; ++p; break;
4878 		case 'n': *name++ = NL; ++p; break;
4879 		case 'r': *name++ = CAR; ++p; break;
4880 		case 't': *name++ = TAB; ++p; break;
4881 
4882 		case 'X': /* hex: "\x1", "\x12" */
4883 		case 'x':
4884 		case 'u': /* Unicode: "\u0023" */
4885 		case 'U':
4886 			  if (vim_isxdigit(p[1]))
4887 			  {
4888 			      int	n, nr;
4889 			      int	c = toupper(*p);
4890 
4891 			      if (c == 'X')
4892 				  n = 2;
4893 			      else if (*p == 'u')
4894 				  n = 4;
4895 			      else
4896 				  n = 8;
4897 			      nr = 0;
4898 			      while (--n >= 0 && vim_isxdigit(p[1]))
4899 			      {
4900 				  ++p;
4901 				  nr = (nr << 4) + hex2nr(*p);
4902 			      }
4903 			      ++p;
4904 #ifdef FEAT_MBYTE
4905 			      /* For "\u" store the number according to
4906 			       * 'encoding'. */
4907 			      if (c != 'X')
4908 				  name += (*mb_char2bytes)(nr, name);
4909 			      else
4910 #endif
4911 				  *name++ = nr;
4912 			  }
4913 			  break;
4914 
4915 			  /* octal: "\1", "\12", "\123" */
4916 		case '0':
4917 		case '1':
4918 		case '2':
4919 		case '3':
4920 		case '4':
4921 		case '5':
4922 		case '6':
4923 		case '7': *name = *p++ - '0';
4924 			  if (*p >= '0' && *p <= '7')
4925 			  {
4926 			      *name = (*name << 3) + *p++ - '0';
4927 			      if (*p >= '0' && *p <= '7')
4928 				  *name = (*name << 3) + *p++ - '0';
4929 			  }
4930 			  ++name;
4931 			  break;
4932 
4933 			    /* Special key, e.g.: "\<C-W>" */
4934 		case '<': extra = trans_special(&p, name, TRUE, TRUE);
4935 			  if (extra != 0)
4936 			  {
4937 			      name += extra;
4938 			      break;
4939 			  }
4940 			  /* FALLTHROUGH */
4941 
4942 		default:  MB_COPY_CHAR(p, name);
4943 			  break;
4944 	    }
4945 	}
4946 	else
4947 	    MB_COPY_CHAR(p, name);
4948 
4949     }
4950     *name = NUL;
4951     if (*p != NUL) /* just in case */
4952 	++p;
4953     *arg = p;
4954 
4955     return OK;
4956 }
4957 
4958 /*
4959  * Allocate a variable for a 'str''ing' constant.
4960  * Return OK or FAIL.
4961  */
4962     static int
4963 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
4964 {
4965     char_u	*p;
4966     char_u	*str;
4967     int		reduce = 0;
4968 
4969     /*
4970      * Find the end of the string, skipping ''.
4971      */
4972     for (p = *arg + 1; *p != NUL; mb_ptr_adv(p))
4973     {
4974 	if (*p == '\'')
4975 	{
4976 	    if (p[1] != '\'')
4977 		break;
4978 	    ++reduce;
4979 	    ++p;
4980 	}
4981     }
4982 
4983     if (*p != '\'')
4984     {
4985 	EMSG2(_("E115: Missing quote: %s"), *arg);
4986 	return FAIL;
4987     }
4988 
4989     /* If only parsing return after setting "*arg" */
4990     if (!evaluate)
4991     {
4992 	*arg = p + 1;
4993 	return OK;
4994     }
4995 
4996     /*
4997      * Copy the string into allocated memory, handling '' to ' reduction.
4998      */
4999     str = alloc((unsigned)((p - *arg) - reduce));
5000     if (str == NULL)
5001 	return FAIL;
5002     rettv->v_type = VAR_STRING;
5003     rettv->vval.v_string = str;
5004 
5005     for (p = *arg + 1; *p != NUL; )
5006     {
5007 	if (*p == '\'')
5008 	{
5009 	    if (p[1] != '\'')
5010 		break;
5011 	    ++p;
5012 	}
5013 	MB_COPY_CHAR(p, str);
5014     }
5015     *str = NUL;
5016     *arg = p + 1;
5017 
5018     return OK;
5019 }
5020 
5021 /*
5022  * Return the function name of the partial.
5023  */
5024     char_u *
5025 partial_name(partial_T *pt)
5026 {
5027     if (pt->pt_name != NULL)
5028 	return pt->pt_name;
5029     return pt->pt_func->uf_name;
5030 }
5031 
5032     static void
5033 partial_free(partial_T *pt)
5034 {
5035     int i;
5036 
5037     for (i = 0; i < pt->pt_argc; ++i)
5038 	clear_tv(&pt->pt_argv[i]);
5039     vim_free(pt->pt_argv);
5040     dict_unref(pt->pt_dict);
5041     if (pt->pt_name != NULL)
5042     {
5043 	func_unref(pt->pt_name);
5044 	vim_free(pt->pt_name);
5045     }
5046     else
5047 	func_ptr_unref(pt->pt_func);
5048     vim_free(pt);
5049 }
5050 
5051 /*
5052  * Unreference a closure: decrement the reference count and free it when it
5053  * becomes zero.
5054  */
5055     void
5056 partial_unref(partial_T *pt)
5057 {
5058     if (pt != NULL && --pt->pt_refcount <= 0)
5059 	partial_free(pt);
5060 }
5061 
5062 static int tv_equal_recurse_limit;
5063 
5064     static int
5065 func_equal(
5066     typval_T *tv1,
5067     typval_T *tv2,
5068     int	     ic)	    /* ignore case */
5069 {
5070     char_u	*s1, *s2;
5071     dict_T	*d1, *d2;
5072     int		a1, a2;
5073     int		i;
5074 
5075     /* empty and NULL function name considered the same */
5076     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
5077 					   : partial_name(tv1->vval.v_partial);
5078     if (s1 != NULL && *s1 == NUL)
5079 	s1 = NULL;
5080     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
5081 					   : partial_name(tv2->vval.v_partial);
5082     if (s2 != NULL && *s2 == NUL)
5083 	s2 = NULL;
5084     if (s1 == NULL || s2 == NULL)
5085     {
5086 	if (s1 != s2)
5087 	    return FALSE;
5088     }
5089     else if (STRCMP(s1, s2) != 0)
5090 	return FALSE;
5091 
5092     /* empty dict and NULL dict is different */
5093     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
5094     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
5095     if (d1 == NULL || d2 == NULL)
5096     {
5097 	if (d1 != d2)
5098 	    return FALSE;
5099     }
5100     else if (!dict_equal(d1, d2, ic, TRUE))
5101 	return FALSE;
5102 
5103     /* empty list and no list considered the same */
5104     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
5105     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
5106     if (a1 != a2)
5107 	return FALSE;
5108     for (i = 0; i < a1; ++i)
5109 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
5110 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
5111 	    return FALSE;
5112 
5113     return TRUE;
5114 }
5115 
5116 /*
5117  * Return TRUE if "tv1" and "tv2" have the same value.
5118  * Compares the items just like "==" would compare them, but strings and
5119  * numbers are different.  Floats and numbers are also different.
5120  */
5121     int
5122 tv_equal(
5123     typval_T *tv1,
5124     typval_T *tv2,
5125     int	     ic,	    /* ignore case */
5126     int	     recursive)	    /* TRUE when used recursively */
5127 {
5128     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
5129     char_u	*s1, *s2;
5130     static int  recursive_cnt = 0;	    /* catch recursive loops */
5131     int		r;
5132 
5133     /* Catch lists and dicts that have an endless loop by limiting
5134      * recursiveness to a limit.  We guess they are equal then.
5135      * A fixed limit has the problem of still taking an awful long time.
5136      * Reduce the limit every time running into it. That should work fine for
5137      * deeply linked structures that are not recursively linked and catch
5138      * recursiveness quickly. */
5139     if (!recursive)
5140 	tv_equal_recurse_limit = 1000;
5141     if (recursive_cnt >= tv_equal_recurse_limit)
5142     {
5143 	--tv_equal_recurse_limit;
5144 	return TRUE;
5145     }
5146 
5147     /* For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
5148      * arguments. */
5149     if ((tv1->v_type == VAR_FUNC
5150 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
5151 	    && (tv2->v_type == VAR_FUNC
5152 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
5153     {
5154 	++recursive_cnt;
5155 	r = func_equal(tv1, tv2, ic);
5156 	--recursive_cnt;
5157 	return r;
5158     }
5159 
5160     if (tv1->v_type != tv2->v_type)
5161 	return FALSE;
5162 
5163     switch (tv1->v_type)
5164     {
5165 	case VAR_LIST:
5166 	    ++recursive_cnt;
5167 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
5168 	    --recursive_cnt;
5169 	    return r;
5170 
5171 	case VAR_DICT:
5172 	    ++recursive_cnt;
5173 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
5174 	    --recursive_cnt;
5175 	    return r;
5176 
5177 	case VAR_NUMBER:
5178 	    return tv1->vval.v_number == tv2->vval.v_number;
5179 
5180 	case VAR_STRING:
5181 	    s1 = get_tv_string_buf(tv1, buf1);
5182 	    s2 = get_tv_string_buf(tv2, buf2);
5183 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
5184 
5185 	case VAR_SPECIAL:
5186 	    return tv1->vval.v_number == tv2->vval.v_number;
5187 
5188 	case VAR_FLOAT:
5189 #ifdef FEAT_FLOAT
5190 	    return tv1->vval.v_float == tv2->vval.v_float;
5191 #endif
5192 	case VAR_JOB:
5193 #ifdef FEAT_JOB_CHANNEL
5194 	    return tv1->vval.v_job == tv2->vval.v_job;
5195 #endif
5196 	case VAR_CHANNEL:
5197 #ifdef FEAT_JOB_CHANNEL
5198 	    return tv1->vval.v_channel == tv2->vval.v_channel;
5199 #endif
5200 	case VAR_FUNC:
5201 	case VAR_PARTIAL:
5202 	case VAR_UNKNOWN:
5203 	    break;
5204     }
5205 
5206     /* VAR_UNKNOWN can be the result of a invalid expression, let's say it
5207      * does not equal anything, not even itself. */
5208     return FALSE;
5209 }
5210 
5211 /*
5212  * Return the next (unique) copy ID.
5213  * Used for serializing nested structures.
5214  */
5215     int
5216 get_copyID(void)
5217 {
5218     current_copyID += COPYID_INC;
5219     return current_copyID;
5220 }
5221 
5222 /*
5223  * Garbage collection for lists and dictionaries.
5224  *
5225  * We use reference counts to be able to free most items right away when they
5226  * are no longer used.  But for composite items it's possible that it becomes
5227  * unused while the reference count is > 0: When there is a recursive
5228  * reference.  Example:
5229  *	:let l = [1, 2, 3]
5230  *	:let d = {9: l}
5231  *	:let l[1] = d
5232  *
5233  * Since this is quite unusual we handle this with garbage collection: every
5234  * once in a while find out which lists and dicts are not referenced from any
5235  * variable.
5236  *
5237  * Here is a good reference text about garbage collection (refers to Python
5238  * but it applies to all reference-counting mechanisms):
5239  *	http://python.ca/nas/python/gc/
5240  */
5241 
5242 /*
5243  * Do garbage collection for lists and dicts.
5244  * When "testing" is TRUE this is called from test_garbagecollect_now().
5245  * Return TRUE if some memory was freed.
5246  */
5247     int
5248 garbage_collect(int testing)
5249 {
5250     int		copyID;
5251     int		abort = FALSE;
5252     buf_T	*buf;
5253     win_T	*wp;
5254     int		i;
5255     int		did_free = FALSE;
5256 #ifdef FEAT_WINDOWS
5257     tabpage_T	*tp;
5258 #endif
5259 
5260     if (!testing)
5261     {
5262 	/* Only do this once. */
5263 	want_garbage_collect = FALSE;
5264 	may_garbage_collect = FALSE;
5265 	garbage_collect_at_exit = FALSE;
5266     }
5267 
5268     /* We advance by two because we add one for items referenced through
5269      * previous_funccal. */
5270     copyID = get_copyID();
5271 
5272     /*
5273      * 1. Go through all accessible variables and mark all lists and dicts
5274      *    with copyID.
5275      */
5276 
5277     /* Don't free variables in the previous_funccal list unless they are only
5278      * referenced through previous_funccal.  This must be first, because if
5279      * the item is referenced elsewhere the funccal must not be freed. */
5280     abort = abort || set_ref_in_previous_funccal(copyID);
5281 
5282     /* script-local variables */
5283     for (i = 1; i <= ga_scripts.ga_len; ++i)
5284 	abort = abort || set_ref_in_ht(&SCRIPT_VARS(i), copyID, NULL);
5285 
5286     /* buffer-local variables */
5287     FOR_ALL_BUFFERS(buf)
5288 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
5289 								  NULL, NULL);
5290 
5291     /* window-local variables */
5292     FOR_ALL_TAB_WINDOWS(tp, wp)
5293 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
5294 								  NULL, NULL);
5295 #ifdef FEAT_AUTOCMD
5296     if (aucmd_win != NULL)
5297 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
5298 								  NULL, NULL);
5299 #endif
5300 
5301 #ifdef FEAT_WINDOWS
5302     /* tabpage-local variables */
5303     FOR_ALL_TABPAGES(tp)
5304 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
5305 								  NULL, NULL);
5306 #endif
5307 
5308     /* global variables */
5309     abort = abort || set_ref_in_ht(&globvarht, copyID, NULL);
5310 
5311     /* function-local variables */
5312     abort = abort || set_ref_in_call_stack(copyID);
5313 
5314     /* named functions (matters for closures) */
5315     abort = abort || set_ref_in_functions(copyID);
5316 
5317     /* function call arguments, if v:testing is set. */
5318     abort = abort || set_ref_in_func_args(copyID);
5319 
5320     /* v: vars */
5321     abort = abort || set_ref_in_ht(&vimvarht, copyID, NULL);
5322 
5323 #ifdef FEAT_LUA
5324     abort = abort || set_ref_in_lua(copyID);
5325 #endif
5326 
5327 #ifdef FEAT_PYTHON
5328     abort = abort || set_ref_in_python(copyID);
5329 #endif
5330 
5331 #ifdef FEAT_PYTHON3
5332     abort = abort || set_ref_in_python3(copyID);
5333 #endif
5334 
5335 #ifdef FEAT_JOB_CHANNEL
5336     abort = abort || set_ref_in_channel(copyID);
5337     abort = abort || set_ref_in_job(copyID);
5338 #endif
5339 #ifdef FEAT_NETBEANS_INTG
5340     abort = abort || set_ref_in_nb_channel(copyID);
5341 #endif
5342 
5343 #ifdef FEAT_TIMERS
5344     abort = abort || set_ref_in_timer(copyID);
5345 #endif
5346 
5347     if (!abort)
5348     {
5349 	/*
5350 	 * 2. Free lists and dictionaries that are not referenced.
5351 	 */
5352 	did_free = free_unref_items(copyID);
5353 
5354 	/*
5355 	 * 3. Check if any funccal can be freed now.
5356 	 *    This may call us back recursively.
5357 	 */
5358 	free_unref_funccal(copyID, testing);
5359     }
5360     else if (p_verbose > 0)
5361     {
5362 	verb_msg((char_u *)_("Not enough memory to set references, garbage collection aborted!"));
5363     }
5364 
5365     return did_free;
5366 }
5367 
5368 /*
5369  * Free lists, dictionaries, channels and jobs that are no longer referenced.
5370  */
5371     static int
5372 free_unref_items(int copyID)
5373 {
5374     int		did_free = FALSE;
5375 
5376     /* Let all "free" functions know that we are here.  This means no
5377      * dictionaries, lists, channels or jobs are to be freed, because we will
5378      * do that here. */
5379     in_free_unref_items = TRUE;
5380 
5381     /*
5382      * PASS 1: free the contents of the items.  We don't free the items
5383      * themselves yet, so that it is possible to decrement refcount counters
5384      */
5385 
5386     /* Go through the list of dicts and free items without the copyID. */
5387     did_free |= dict_free_nonref(copyID);
5388 
5389     /* Go through the list of lists and free items without the copyID. */
5390     did_free |= list_free_nonref(copyID);
5391 
5392 #ifdef FEAT_JOB_CHANNEL
5393     /* Go through the list of jobs and free items without the copyID. This
5394      * must happen before doing channels, because jobs refer to channels, but
5395      * the reference from the channel to the job isn't tracked. */
5396     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
5397 
5398     /* Go through the list of channels and free items without the copyID.  */
5399     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
5400 #endif
5401 
5402     /*
5403      * PASS 2: free the items themselves.
5404      */
5405     dict_free_items(copyID);
5406     list_free_items(copyID);
5407 
5408 #ifdef FEAT_JOB_CHANNEL
5409     /* Go through the list of jobs and free items without the copyID. This
5410      * must happen before doing channels, because jobs refer to channels, but
5411      * the reference from the channel to the job isn't tracked. */
5412     free_unused_jobs(copyID, COPYID_MASK);
5413 
5414     /* Go through the list of channels and free items without the copyID.  */
5415     free_unused_channels(copyID, COPYID_MASK);
5416 #endif
5417 
5418     in_free_unref_items = FALSE;
5419 
5420     return did_free;
5421 }
5422 
5423 /*
5424  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
5425  * "list_stack" is used to add lists to be marked.  Can be NULL.
5426  *
5427  * Returns TRUE if setting references failed somehow.
5428  */
5429     int
5430 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
5431 {
5432     int		todo;
5433     int		abort = FALSE;
5434     hashitem_T	*hi;
5435     hashtab_T	*cur_ht;
5436     ht_stack_T	*ht_stack = NULL;
5437     ht_stack_T	*tempitem;
5438 
5439     cur_ht = ht;
5440     for (;;)
5441     {
5442 	if (!abort)
5443 	{
5444 	    /* Mark each item in the hashtab.  If the item contains a hashtab
5445 	     * it is added to ht_stack, if it contains a list it is added to
5446 	     * list_stack. */
5447 	    todo = (int)cur_ht->ht_used;
5448 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
5449 		if (!HASHITEM_EMPTY(hi))
5450 		{
5451 		    --todo;
5452 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
5453 						       &ht_stack, list_stack);
5454 		}
5455 	}
5456 
5457 	if (ht_stack == NULL)
5458 	    break;
5459 
5460 	/* take an item from the stack */
5461 	cur_ht = ht_stack->ht;
5462 	tempitem = ht_stack;
5463 	ht_stack = ht_stack->prev;
5464 	free(tempitem);
5465     }
5466 
5467     return abort;
5468 }
5469 
5470 /*
5471  * Mark all lists and dicts referenced through list "l" with "copyID".
5472  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5473  *
5474  * Returns TRUE if setting references failed somehow.
5475  */
5476     int
5477 set_ref_in_list(list_T *l, int copyID, ht_stack_T **ht_stack)
5478 {
5479     listitem_T	 *li;
5480     int		 abort = FALSE;
5481     list_T	 *cur_l;
5482     list_stack_T *list_stack = NULL;
5483     list_stack_T *tempitem;
5484 
5485     cur_l = l;
5486     for (;;)
5487     {
5488 	if (!abort)
5489 	    /* Mark each item in the list.  If the item contains a hashtab
5490 	     * it is added to ht_stack, if it contains a list it is added to
5491 	     * list_stack. */
5492 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
5493 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
5494 						       ht_stack, &list_stack);
5495 	if (list_stack == NULL)
5496 	    break;
5497 
5498 	/* take an item from the stack */
5499 	cur_l = list_stack->list;
5500 	tempitem = list_stack;
5501 	list_stack = list_stack->prev;
5502 	free(tempitem);
5503     }
5504 
5505     return abort;
5506 }
5507 
5508 /*
5509  * Mark all lists and dicts referenced through typval "tv" with "copyID".
5510  * "list_stack" is used to add lists to be marked.  Can be NULL.
5511  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5512  *
5513  * Returns TRUE if setting references failed somehow.
5514  */
5515     int
5516 set_ref_in_item(
5517     typval_T	    *tv,
5518     int		    copyID,
5519     ht_stack_T	    **ht_stack,
5520     list_stack_T    **list_stack)
5521 {
5522     int		abort = FALSE;
5523 
5524     if (tv->v_type == VAR_DICT)
5525     {
5526 	dict_T	*dd = tv->vval.v_dict;
5527 
5528 	if (dd != NULL && dd->dv_copyID != copyID)
5529 	{
5530 	    /* Didn't see this dict yet. */
5531 	    dd->dv_copyID = copyID;
5532 	    if (ht_stack == NULL)
5533 	    {
5534 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
5535 	    }
5536 	    else
5537 	    {
5538 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
5539 		if (newitem == NULL)
5540 		    abort = TRUE;
5541 		else
5542 		{
5543 		    newitem->ht = &dd->dv_hashtab;
5544 		    newitem->prev = *ht_stack;
5545 		    *ht_stack = newitem;
5546 		}
5547 	    }
5548 	}
5549     }
5550     else if (tv->v_type == VAR_LIST)
5551     {
5552 	list_T	*ll = tv->vval.v_list;
5553 
5554 	if (ll != NULL && ll->lv_copyID != copyID)
5555 	{
5556 	    /* Didn't see this list yet. */
5557 	    ll->lv_copyID = copyID;
5558 	    if (list_stack == NULL)
5559 	    {
5560 		abort = set_ref_in_list(ll, copyID, ht_stack);
5561 	    }
5562 	    else
5563 	    {
5564 		list_stack_T *newitem = (list_stack_T*)malloc(
5565 							sizeof(list_stack_T));
5566 		if (newitem == NULL)
5567 		    abort = TRUE;
5568 		else
5569 		{
5570 		    newitem->list = ll;
5571 		    newitem->prev = *list_stack;
5572 		    *list_stack = newitem;
5573 		}
5574 	    }
5575 	}
5576     }
5577     else if (tv->v_type == VAR_FUNC)
5578     {
5579 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
5580     }
5581     else if (tv->v_type == VAR_PARTIAL)
5582     {
5583 	partial_T	*pt = tv->vval.v_partial;
5584 	int		i;
5585 
5586 	/* A partial does not have a copyID, because it cannot contain itself.
5587 	 */
5588 	if (pt != NULL)
5589 	{
5590 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
5591 
5592 	    if (pt->pt_dict != NULL)
5593 	    {
5594 		typval_T dtv;
5595 
5596 		dtv.v_type = VAR_DICT;
5597 		dtv.vval.v_dict = pt->pt_dict;
5598 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5599 	    }
5600 
5601 	    for (i = 0; i < pt->pt_argc; ++i)
5602 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
5603 							ht_stack, list_stack);
5604 	}
5605     }
5606 #ifdef FEAT_JOB_CHANNEL
5607     else if (tv->v_type == VAR_JOB)
5608     {
5609 	job_T	    *job = tv->vval.v_job;
5610 	typval_T    dtv;
5611 
5612 	if (job != NULL && job->jv_copyID != copyID)
5613 	{
5614 	    job->jv_copyID = copyID;
5615 	    if (job->jv_channel != NULL)
5616 	    {
5617 		dtv.v_type = VAR_CHANNEL;
5618 		dtv.vval.v_channel = job->jv_channel;
5619 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5620 	    }
5621 	    if (job->jv_exit_partial != NULL)
5622 	    {
5623 		dtv.v_type = VAR_PARTIAL;
5624 		dtv.vval.v_partial = job->jv_exit_partial;
5625 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5626 	    }
5627 	}
5628     }
5629     else if (tv->v_type == VAR_CHANNEL)
5630     {
5631 	channel_T   *ch =tv->vval.v_channel;
5632 	ch_part_T   part;
5633 	typval_T    dtv;
5634 	jsonq_T	    *jq;
5635 	cbq_T	    *cq;
5636 
5637 	if (ch != NULL && ch->ch_copyID != copyID)
5638 	{
5639 	    ch->ch_copyID = copyID;
5640 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
5641 	    {
5642 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
5643 							     jq = jq->jq_next)
5644 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
5645 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
5646 							     cq = cq->cq_next)
5647 		    if (cq->cq_partial != NULL)
5648 		    {
5649 			dtv.v_type = VAR_PARTIAL;
5650 			dtv.vval.v_partial = cq->cq_partial;
5651 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5652 		    }
5653 		if (ch->ch_part[part].ch_partial != NULL)
5654 		{
5655 		    dtv.v_type = VAR_PARTIAL;
5656 		    dtv.vval.v_partial = ch->ch_part[part].ch_partial;
5657 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5658 		}
5659 	    }
5660 	    if (ch->ch_partial != NULL)
5661 	    {
5662 		dtv.v_type = VAR_PARTIAL;
5663 		dtv.vval.v_partial = ch->ch_partial;
5664 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5665 	    }
5666 	    if (ch->ch_close_partial != NULL)
5667 	    {
5668 		dtv.v_type = VAR_PARTIAL;
5669 		dtv.vval.v_partial = ch->ch_close_partial;
5670 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5671 	    }
5672 	}
5673     }
5674 #endif
5675     return abort;
5676 }
5677 
5678     static char *
5679 get_var_special_name(int nr)
5680 {
5681     switch (nr)
5682     {
5683 	case VVAL_FALSE: return "v:false";
5684 	case VVAL_TRUE:  return "v:true";
5685 	case VVAL_NONE:  return "v:none";
5686 	case VVAL_NULL:  return "v:null";
5687     }
5688     internal_error("get_var_special_name()");
5689     return "42";
5690 }
5691 
5692 /*
5693  * Return a string with the string representation of a variable.
5694  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5695  * "numbuf" is used for a number.
5696  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5697  * When both "echo_style" and "dict_val" are FALSE, put quotes around stings as
5698  * "string()", otherwise does not put quotes around strings, as ":echo"
5699  * displays values.
5700  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
5701  * are replaced with "...".
5702  * May return NULL.
5703  */
5704     char_u *
5705 echo_string_core(
5706     typval_T	*tv,
5707     char_u	**tofree,
5708     char_u	*numbuf,
5709     int		copyID,
5710     int		echo_style,
5711     int		restore_copyID,
5712     int		dict_val)
5713 {
5714     static int	recurse = 0;
5715     char_u	*r = NULL;
5716 
5717     if (recurse >= DICT_MAXNEST)
5718     {
5719 	if (!did_echo_string_emsg)
5720 	{
5721 	    /* Only give this message once for a recursive call to avoid
5722 	     * flooding the user with errors.  And stop iterating over lists
5723 	     * and dicts. */
5724 	    did_echo_string_emsg = TRUE;
5725 	    EMSG(_("E724: variable nested too deep for displaying"));
5726 	}
5727 	*tofree = NULL;
5728 	return (char_u *)"{E724}";
5729     }
5730     ++recurse;
5731 
5732     switch (tv->v_type)
5733     {
5734 	case VAR_STRING:
5735 	    if (echo_style && !dict_val)
5736 	    {
5737 		*tofree = NULL;
5738 		r = get_tv_string_buf(tv, numbuf);
5739 	    }
5740 	    else
5741 	    {
5742 		*tofree = string_quote(tv->vval.v_string, FALSE);
5743 		r = *tofree;
5744 	    }
5745 	    break;
5746 
5747 	case VAR_FUNC:
5748 	    if (echo_style)
5749 	    {
5750 		*tofree = NULL;
5751 		r = tv->vval.v_string;
5752 	    }
5753 	    else
5754 	    {
5755 		*tofree = string_quote(tv->vval.v_string, TRUE);
5756 		r = *tofree;
5757 	    }
5758 	    break;
5759 
5760 	case VAR_PARTIAL:
5761 	    {
5762 		partial_T   *pt = tv->vval.v_partial;
5763 		char_u	    *fname = string_quote(pt == NULL ? NULL
5764 						    : partial_name(pt), FALSE);
5765 		garray_T    ga;
5766 		int	    i;
5767 		char_u	    *tf;
5768 
5769 		ga_init2(&ga, 1, 100);
5770 		ga_concat(&ga, (char_u *)"function(");
5771 		if (fname != NULL)
5772 		{
5773 		    ga_concat(&ga, fname);
5774 		    vim_free(fname);
5775 		}
5776 		if (pt != NULL && pt->pt_argc > 0)
5777 		{
5778 		    ga_concat(&ga, (char_u *)", [");
5779 		    for (i = 0; i < pt->pt_argc; ++i)
5780 		    {
5781 			if (i > 0)
5782 			    ga_concat(&ga, (char_u *)", ");
5783 			ga_concat(&ga,
5784 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
5785 			vim_free(tf);
5786 		    }
5787 		    ga_concat(&ga, (char_u *)"]");
5788 		}
5789 		if (pt != NULL && pt->pt_dict != NULL)
5790 		{
5791 		    typval_T dtv;
5792 
5793 		    ga_concat(&ga, (char_u *)", ");
5794 		    dtv.v_type = VAR_DICT;
5795 		    dtv.vval.v_dict = pt->pt_dict;
5796 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
5797 		    vim_free(tf);
5798 		}
5799 		ga_concat(&ga, (char_u *)")");
5800 
5801 		*tofree = ga.ga_data;
5802 		r = *tofree;
5803 		break;
5804 	    }
5805 
5806 	case VAR_LIST:
5807 	    if (tv->vval.v_list == NULL)
5808 	    {
5809 		*tofree = NULL;
5810 		r = NULL;
5811 	    }
5812 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
5813 		    && tv->vval.v_list->lv_len > 0)
5814 	    {
5815 		*tofree = NULL;
5816 		r = (char_u *)"[...]";
5817 	    }
5818 	    else
5819 	    {
5820 		int old_copyID = tv->vval.v_list->lv_copyID;
5821 
5822 		tv->vval.v_list->lv_copyID = copyID;
5823 		*tofree = list2string(tv, copyID, restore_copyID);
5824 		if (restore_copyID)
5825 		    tv->vval.v_list->lv_copyID = old_copyID;
5826 		r = *tofree;
5827 	    }
5828 	    break;
5829 
5830 	case VAR_DICT:
5831 	    if (tv->vval.v_dict == NULL)
5832 	    {
5833 		*tofree = NULL;
5834 		r = NULL;
5835 	    }
5836 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
5837 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
5838 	    {
5839 		*tofree = NULL;
5840 		r = (char_u *)"{...}";
5841 	    }
5842 	    else
5843 	    {
5844 		int old_copyID = tv->vval.v_dict->dv_copyID;
5845 		tv->vval.v_dict->dv_copyID = copyID;
5846 		*tofree = dict2string(tv, copyID, restore_copyID);
5847 		if (restore_copyID)
5848 		    tv->vval.v_dict->dv_copyID = old_copyID;
5849 		r = *tofree;
5850 	    }
5851 	    break;
5852 
5853 	case VAR_NUMBER:
5854 	case VAR_UNKNOWN:
5855 	case VAR_JOB:
5856 	case VAR_CHANNEL:
5857 	    *tofree = NULL;
5858 	    r = get_tv_string_buf(tv, numbuf);
5859 	    break;
5860 
5861 	case VAR_FLOAT:
5862 #ifdef FEAT_FLOAT
5863 	    *tofree = NULL;
5864 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
5865 	    r = numbuf;
5866 	    break;
5867 #endif
5868 
5869 	case VAR_SPECIAL:
5870 	    *tofree = NULL;
5871 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
5872 	    break;
5873     }
5874 
5875     if (--recurse == 0)
5876 	did_echo_string_emsg = FALSE;
5877     return r;
5878 }
5879 
5880 /*
5881  * Return a string with the string representation of a variable.
5882  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5883  * "numbuf" is used for a number.
5884  * Does not put quotes around strings, as ":echo" displays values.
5885  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5886  * May return NULL.
5887  */
5888     char_u *
5889 echo_string(
5890     typval_T	*tv,
5891     char_u	**tofree,
5892     char_u	*numbuf,
5893     int		copyID)
5894 {
5895     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
5896 }
5897 
5898 /*
5899  * Return a string with the string representation of a variable.
5900  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5901  * "numbuf" is used for a number.
5902  * Puts quotes around strings, so that they can be parsed back by eval().
5903  * May return NULL.
5904  */
5905     char_u *
5906 tv2string(
5907     typval_T	*tv,
5908     char_u	**tofree,
5909     char_u	*numbuf,
5910     int		copyID)
5911 {
5912     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
5913 }
5914 
5915 /*
5916  * Return string "str" in ' quotes, doubling ' characters.
5917  * If "str" is NULL an empty string is assumed.
5918  * If "function" is TRUE make it function('string').
5919  */
5920     char_u *
5921 string_quote(char_u *str, int function)
5922 {
5923     unsigned	len;
5924     char_u	*p, *r, *s;
5925 
5926     len = (function ? 13 : 3);
5927     if (str != NULL)
5928     {
5929 	len += (unsigned)STRLEN(str);
5930 	for (p = str; *p != NUL; mb_ptr_adv(p))
5931 	    if (*p == '\'')
5932 		++len;
5933     }
5934     s = r = alloc(len);
5935     if (r != NULL)
5936     {
5937 	if (function)
5938 	{
5939 	    STRCPY(r, "function('");
5940 	    r += 10;
5941 	}
5942 	else
5943 	    *r++ = '\'';
5944 	if (str != NULL)
5945 	    for (p = str; *p != NUL; )
5946 	    {
5947 		if (*p == '\'')
5948 		    *r++ = '\'';
5949 		MB_COPY_CHAR(p, r);
5950 	    }
5951 	*r++ = '\'';
5952 	if (function)
5953 	    *r++ = ')';
5954 	*r++ = NUL;
5955     }
5956     return s;
5957 }
5958 
5959 #if defined(FEAT_FLOAT) || defined(PROTO)
5960 /*
5961  * Convert the string "text" to a floating point number.
5962  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
5963  * this always uses a decimal point.
5964  * Returns the length of the text that was consumed.
5965  */
5966     int
5967 string2float(
5968     char_u	*text,
5969     float_T	*value)	    /* result stored here */
5970 {
5971     char	*s = (char *)text;
5972     float_T	f;
5973 
5974     f = strtod(s, &s);
5975     *value = f;
5976     return (int)((char_u *)s - text);
5977 }
5978 #endif
5979 
5980 /*
5981  * Get the value of an environment variable.
5982  * "arg" is pointing to the '$'.  It is advanced to after the name.
5983  * If the environment variable was not set, silently assume it is empty.
5984  * Return FAIL if the name is invalid.
5985  */
5986     static int
5987 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
5988 {
5989     char_u	*string = NULL;
5990     int		len;
5991     int		cc;
5992     char_u	*name;
5993     int		mustfree = FALSE;
5994 
5995     ++*arg;
5996     name = *arg;
5997     len = get_env_len(arg);
5998     if (evaluate)
5999     {
6000 	if (len == 0)
6001 	    return FAIL; /* invalid empty name */
6002 
6003 	cc = name[len];
6004 	name[len] = NUL;
6005 	/* first try vim_getenv(), fast for normal environment vars */
6006 	string = vim_getenv(name, &mustfree);
6007 	if (string != NULL && *string != NUL)
6008 	{
6009 	    if (!mustfree)
6010 		string = vim_strsave(string);
6011 	}
6012 	else
6013 	{
6014 	    if (mustfree)
6015 		vim_free(string);
6016 
6017 	    /* next try expanding things like $VIM and ${HOME} */
6018 	    string = expand_env_save(name - 1);
6019 	    if (string != NULL && *string == '$')
6020 	    {
6021 		vim_free(string);
6022 		string = NULL;
6023 	    }
6024 	}
6025 	name[len] = cc;
6026 
6027 	rettv->v_type = VAR_STRING;
6028 	rettv->vval.v_string = string;
6029     }
6030 
6031     return OK;
6032 }
6033 
6034 
6035 
6036 /*
6037  * Translate a String variable into a position.
6038  * Returns NULL when there is an error.
6039  */
6040     pos_T *
6041 var2fpos(
6042     typval_T	*varp,
6043     int		dollar_lnum,	/* TRUE when $ is last line */
6044     int		*fnum)		/* set to fnum for '0, 'A, etc. */
6045 {
6046     char_u		*name;
6047     static pos_T	pos;
6048     pos_T		*pp;
6049 
6050     /* Argument can be [lnum, col, coladd]. */
6051     if (varp->v_type == VAR_LIST)
6052     {
6053 	list_T		*l;
6054 	int		len;
6055 	int		error = FALSE;
6056 	listitem_T	*li;
6057 
6058 	l = varp->vval.v_list;
6059 	if (l == NULL)
6060 	    return NULL;
6061 
6062 	/* Get the line number */
6063 	pos.lnum = list_find_nr(l, 0L, &error);
6064 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
6065 	    return NULL;	/* invalid line number */
6066 
6067 	/* Get the column number */
6068 	pos.col = list_find_nr(l, 1L, &error);
6069 	if (error)
6070 	    return NULL;
6071 	len = (long)STRLEN(ml_get(pos.lnum));
6072 
6073 	/* We accept "$" for the column number: last column. */
6074 	li = list_find(l, 1L);
6075 	if (li != NULL && li->li_tv.v_type == VAR_STRING
6076 		&& li->li_tv.vval.v_string != NULL
6077 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
6078 	    pos.col = len + 1;
6079 
6080 	/* Accept a position up to the NUL after the line. */
6081 	if (pos.col == 0 || (int)pos.col > len + 1)
6082 	    return NULL;	/* invalid column number */
6083 	--pos.col;
6084 
6085 #ifdef FEAT_VIRTUALEDIT
6086 	/* Get the virtual offset.  Defaults to zero. */
6087 	pos.coladd = list_find_nr(l, 2L, &error);
6088 	if (error)
6089 	    pos.coladd = 0;
6090 #endif
6091 
6092 	return &pos;
6093     }
6094 
6095     name = get_tv_string_chk(varp);
6096     if (name == NULL)
6097 	return NULL;
6098     if (name[0] == '.')				/* cursor */
6099 	return &curwin->w_cursor;
6100     if (name[0] == 'v' && name[1] == NUL)	/* Visual start */
6101     {
6102 	if (VIsual_active)
6103 	    return &VIsual;
6104 	return &curwin->w_cursor;
6105     }
6106     if (name[0] == '\'')			/* mark */
6107     {
6108 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
6109 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
6110 	    return NULL;
6111 	return pp;
6112     }
6113 
6114 #ifdef FEAT_VIRTUALEDIT
6115     pos.coladd = 0;
6116 #endif
6117 
6118     if (name[0] == 'w' && dollar_lnum)
6119     {
6120 	pos.col = 0;
6121 	if (name[1] == '0')		/* "w0": first visible line */
6122 	{
6123 	    update_topline();
6124 	    pos.lnum = curwin->w_topline;
6125 	    return &pos;
6126 	}
6127 	else if (name[1] == '$')	/* "w$": last visible line */
6128 	{
6129 	    validate_botline();
6130 	    pos.lnum = curwin->w_botline - 1;
6131 	    return &pos;
6132 	}
6133     }
6134     else if (name[0] == '$')		/* last column or line */
6135     {
6136 	if (dollar_lnum)
6137 	{
6138 	    pos.lnum = curbuf->b_ml.ml_line_count;
6139 	    pos.col = 0;
6140 	}
6141 	else
6142 	{
6143 	    pos.lnum = curwin->w_cursor.lnum;
6144 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
6145 	}
6146 	return &pos;
6147     }
6148     return NULL;
6149 }
6150 
6151 /*
6152  * Convert list in "arg" into a position and optional file number.
6153  * When "fnump" is NULL there is no file number, only 3 items.
6154  * Note that the column is passed on as-is, the caller may want to decrement
6155  * it to use 1 for the first column.
6156  * Return FAIL when conversion is not possible, doesn't check the position for
6157  * validity.
6158  */
6159     int
6160 list2fpos(
6161     typval_T	*arg,
6162     pos_T	*posp,
6163     int		*fnump,
6164     colnr_T	*curswantp)
6165 {
6166     list_T	*l = arg->vval.v_list;
6167     long	i = 0;
6168     long	n;
6169 
6170     /* List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
6171      * there when "fnump" isn't NULL; "coladd" and "curswant" are optional. */
6172     if (arg->v_type != VAR_LIST
6173 	    || l == NULL
6174 	    || l->lv_len < (fnump == NULL ? 2 : 3)
6175 	    || l->lv_len > (fnump == NULL ? 4 : 5))
6176 	return FAIL;
6177 
6178     if (fnump != NULL)
6179     {
6180 	n = list_find_nr(l, i++, NULL);	/* fnum */
6181 	if (n < 0)
6182 	    return FAIL;
6183 	if (n == 0)
6184 	    n = curbuf->b_fnum;		/* current buffer */
6185 	*fnump = n;
6186     }
6187 
6188     n = list_find_nr(l, i++, NULL);	/* lnum */
6189     if (n < 0)
6190 	return FAIL;
6191     posp->lnum = n;
6192 
6193     n = list_find_nr(l, i++, NULL);	/* col */
6194     if (n < 0)
6195 	return FAIL;
6196     posp->col = n;
6197 
6198 #ifdef FEAT_VIRTUALEDIT
6199     n = list_find_nr(l, i, NULL);	/* off */
6200     if (n < 0)
6201 	posp->coladd = 0;
6202     else
6203 	posp->coladd = n;
6204 #endif
6205 
6206     if (curswantp != NULL)
6207 	*curswantp = list_find_nr(l, i + 1, NULL);  /* curswant */
6208 
6209     return OK;
6210 }
6211 
6212 /*
6213  * Get the length of an environment variable name.
6214  * Advance "arg" to the first character after the name.
6215  * Return 0 for error.
6216  */
6217     static int
6218 get_env_len(char_u **arg)
6219 {
6220     char_u	*p;
6221     int		len;
6222 
6223     for (p = *arg; vim_isIDc(*p); ++p)
6224 	;
6225     if (p == *arg)	    /* no name found */
6226 	return 0;
6227 
6228     len = (int)(p - *arg);
6229     *arg = p;
6230     return len;
6231 }
6232 
6233 /*
6234  * Get the length of the name of a function or internal variable.
6235  * "arg" is advanced to the first non-white character after the name.
6236  * Return 0 if something is wrong.
6237  */
6238     int
6239 get_id_len(char_u **arg)
6240 {
6241     char_u	*p;
6242     int		len;
6243 
6244     /* Find the end of the name. */
6245     for (p = *arg; eval_isnamec(*p); ++p)
6246     {
6247 	if (*p == ':')
6248 	{
6249 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6250 	     * slice "[n:]".  Also "xx:" is not a namespace. */
6251 	    len = (int)(p - *arg);
6252 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
6253 		    || len > 1)
6254 		break;
6255 	}
6256     }
6257     if (p == *arg)	    /* no name found */
6258 	return 0;
6259 
6260     len = (int)(p - *arg);
6261     *arg = skipwhite(p);
6262 
6263     return len;
6264 }
6265 
6266 /*
6267  * Get the length of the name of a variable or function.
6268  * Only the name is recognized, does not handle ".key" or "[idx]".
6269  * "arg" is advanced to the first non-white character after the name.
6270  * Return -1 if curly braces expansion failed.
6271  * Return 0 if something else is wrong.
6272  * If the name contains 'magic' {}'s, expand them and return the
6273  * expanded name in an allocated string via 'alias' - caller must free.
6274  */
6275     int
6276 get_name_len(
6277     char_u	**arg,
6278     char_u	**alias,
6279     int		evaluate,
6280     int		verbose)
6281 {
6282     int		len;
6283     char_u	*p;
6284     char_u	*expr_start;
6285     char_u	*expr_end;
6286 
6287     *alias = NULL;  /* default to no alias */
6288 
6289     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
6290 						  && (*arg)[2] == (int)KE_SNR)
6291     {
6292 	/* hard coded <SNR>, already translated */
6293 	*arg += 3;
6294 	return get_id_len(arg) + 3;
6295     }
6296     len = eval_fname_script(*arg);
6297     if (len > 0)
6298     {
6299 	/* literal "<SID>", "s:" or "<SNR>" */
6300 	*arg += len;
6301     }
6302 
6303     /*
6304      * Find the end of the name; check for {} construction.
6305      */
6306     p = find_name_end(*arg, &expr_start, &expr_end,
6307 					       len > 0 ? 0 : FNE_CHECK_START);
6308     if (expr_start != NULL)
6309     {
6310 	char_u	*temp_string;
6311 
6312 	if (!evaluate)
6313 	{
6314 	    len += (int)(p - *arg);
6315 	    *arg = skipwhite(p);
6316 	    return len;
6317 	}
6318 
6319 	/*
6320 	 * Include any <SID> etc in the expanded string:
6321 	 * Thus the -len here.
6322 	 */
6323 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
6324 	if (temp_string == NULL)
6325 	    return -1;
6326 	*alias = temp_string;
6327 	*arg = skipwhite(p);
6328 	return (int)STRLEN(temp_string);
6329     }
6330 
6331     len += get_id_len(arg);
6332     if (len == 0 && verbose)
6333 	EMSG2(_(e_invexpr2), *arg);
6334 
6335     return len;
6336 }
6337 
6338 /*
6339  * Find the end of a variable or function name, taking care of magic braces.
6340  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
6341  * start and end of the first magic braces item.
6342  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
6343  * Return a pointer to just after the name.  Equal to "arg" if there is no
6344  * valid name.
6345  */
6346     char_u *
6347 find_name_end(
6348     char_u	*arg,
6349     char_u	**expr_start,
6350     char_u	**expr_end,
6351     int		flags)
6352 {
6353     int		mb_nest = 0;
6354     int		br_nest = 0;
6355     char_u	*p;
6356     int		len;
6357 
6358     if (expr_start != NULL)
6359     {
6360 	*expr_start = NULL;
6361 	*expr_end = NULL;
6362     }
6363 
6364     /* Quick check for valid starting character. */
6365     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg) && *arg != '{')
6366 	return arg;
6367 
6368     for (p = arg; *p != NUL
6369 		    && (eval_isnamec(*p)
6370 			|| *p == '{'
6371 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
6372 			|| mb_nest != 0
6373 			|| br_nest != 0); mb_ptr_adv(p))
6374     {
6375 	if (*p == '\'')
6376 	{
6377 	    /* skip over 'string' to avoid counting [ and ] inside it. */
6378 	    for (p = p + 1; *p != NUL && *p != '\''; mb_ptr_adv(p))
6379 		;
6380 	    if (*p == NUL)
6381 		break;
6382 	}
6383 	else if (*p == '"')
6384 	{
6385 	    /* skip over "str\"ing" to avoid counting [ and ] inside it. */
6386 	    for (p = p + 1; *p != NUL && *p != '"'; mb_ptr_adv(p))
6387 		if (*p == '\\' && p[1] != NUL)
6388 		    ++p;
6389 	    if (*p == NUL)
6390 		break;
6391 	}
6392 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
6393 	{
6394 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6395 	     * slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is. */
6396 	    len = (int)(p - arg);
6397 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
6398 		    || (len > 1 && p[-1] != '}'))
6399 		break;
6400 	}
6401 
6402 	if (mb_nest == 0)
6403 	{
6404 	    if (*p == '[')
6405 		++br_nest;
6406 	    else if (*p == ']')
6407 		--br_nest;
6408 	}
6409 
6410 	if (br_nest == 0)
6411 	{
6412 	    if (*p == '{')
6413 	    {
6414 		mb_nest++;
6415 		if (expr_start != NULL && *expr_start == NULL)
6416 		    *expr_start = p;
6417 	    }
6418 	    else if (*p == '}')
6419 	    {
6420 		mb_nest--;
6421 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
6422 		    *expr_end = p;
6423 	    }
6424 	}
6425     }
6426 
6427     return p;
6428 }
6429 
6430 /*
6431  * Expands out the 'magic' {}'s in a variable/function name.
6432  * Note that this can call itself recursively, to deal with
6433  * constructs like foo{bar}{baz}{bam}
6434  * The four pointer arguments point to "foo{expre}ss{ion}bar"
6435  *			"in_start"      ^
6436  *			"expr_start"	   ^
6437  *			"expr_end"		 ^
6438  *			"in_end"			    ^
6439  *
6440  * Returns a new allocated string, which the caller must free.
6441  * Returns NULL for failure.
6442  */
6443     static char_u *
6444 make_expanded_name(
6445     char_u	*in_start,
6446     char_u	*expr_start,
6447     char_u	*expr_end,
6448     char_u	*in_end)
6449 {
6450     char_u	c1;
6451     char_u	*retval = NULL;
6452     char_u	*temp_result;
6453     char_u	*nextcmd = NULL;
6454 
6455     if (expr_end == NULL || in_end == NULL)
6456 	return NULL;
6457     *expr_start	= NUL;
6458     *expr_end = NUL;
6459     c1 = *in_end;
6460     *in_end = NUL;
6461 
6462     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
6463     if (temp_result != NULL && nextcmd == NULL)
6464     {
6465 	retval = alloc((unsigned)(STRLEN(temp_result) + (expr_start - in_start)
6466 						   + (in_end - expr_end) + 1));
6467 	if (retval != NULL)
6468 	{
6469 	    STRCPY(retval, in_start);
6470 	    STRCAT(retval, temp_result);
6471 	    STRCAT(retval, expr_end + 1);
6472 	}
6473     }
6474     vim_free(temp_result);
6475 
6476     *in_end = c1;		/* put char back for error messages */
6477     *expr_start = '{';
6478     *expr_end = '}';
6479 
6480     if (retval != NULL)
6481     {
6482 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
6483 	if (expr_start != NULL)
6484 	{
6485 	    /* Further expansion! */
6486 	    temp_result = make_expanded_name(retval, expr_start,
6487 						       expr_end, temp_result);
6488 	    vim_free(retval);
6489 	    retval = temp_result;
6490 	}
6491     }
6492 
6493     return retval;
6494 }
6495 
6496 /*
6497  * Return TRUE if character "c" can be used in a variable or function name.
6498  * Does not include '{' or '}' for magic braces.
6499  */
6500     int
6501 eval_isnamec(int c)
6502 {
6503     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
6504 }
6505 
6506 /*
6507  * Return TRUE if character "c" can be used as the first character in a
6508  * variable or function name (excluding '{' and '}').
6509  */
6510     int
6511 eval_isnamec1(int c)
6512 {
6513     return (ASCII_ISALPHA(c) || c == '_');
6514 }
6515 
6516 /*
6517  * Set number v: variable to "val".
6518  */
6519     void
6520 set_vim_var_nr(int idx, varnumber_T val)
6521 {
6522     vimvars[idx].vv_nr = val;
6523 }
6524 
6525 /*
6526  * Get number v: variable value.
6527  */
6528     varnumber_T
6529 get_vim_var_nr(int idx)
6530 {
6531     return vimvars[idx].vv_nr;
6532 }
6533 
6534 /*
6535  * Get string v: variable value.  Uses a static buffer, can only be used once.
6536  */
6537     char_u *
6538 get_vim_var_str(int idx)
6539 {
6540     return get_tv_string(&vimvars[idx].vv_tv);
6541 }
6542 
6543 /*
6544  * Get List v: variable value.  Caller must take care of reference count when
6545  * needed.
6546  */
6547     list_T *
6548 get_vim_var_list(int idx)
6549 {
6550     return vimvars[idx].vv_list;
6551 }
6552 
6553 /*
6554  * Set v:char to character "c".
6555  */
6556     void
6557 set_vim_var_char(int c)
6558 {
6559     char_u	buf[MB_MAXBYTES + 1];
6560 
6561 #ifdef FEAT_MBYTE
6562     if (has_mbyte)
6563 	buf[(*mb_char2bytes)(c, buf)] = NUL;
6564     else
6565 #endif
6566     {
6567 	buf[0] = c;
6568 	buf[1] = NUL;
6569     }
6570     set_vim_var_string(VV_CHAR, buf, -1);
6571 }
6572 
6573 /*
6574  * Set v:count to "count" and v:count1 to "count1".
6575  * When "set_prevcount" is TRUE first set v:prevcount from v:count.
6576  */
6577     void
6578 set_vcount(
6579     long	count,
6580     long	count1,
6581     int		set_prevcount)
6582 {
6583     if (set_prevcount)
6584 	vimvars[VV_PREVCOUNT].vv_nr = vimvars[VV_COUNT].vv_nr;
6585     vimvars[VV_COUNT].vv_nr = count;
6586     vimvars[VV_COUNT1].vv_nr = count1;
6587 }
6588 
6589 /*
6590  * Set string v: variable to a copy of "val".
6591  */
6592     void
6593 set_vim_var_string(
6594     int		idx,
6595     char_u	*val,
6596     int		len)	    /* length of "val" to use or -1 (whole string) */
6597 {
6598     clear_tv(&vimvars[idx].vv_di.di_tv);
6599     vimvars[idx].vv_type = VAR_STRING;
6600     if (val == NULL)
6601 	vimvars[idx].vv_str = NULL;
6602     else if (len == -1)
6603 	vimvars[idx].vv_str = vim_strsave(val);
6604     else
6605 	vimvars[idx].vv_str = vim_strnsave(val, len);
6606 }
6607 
6608 /*
6609  * Set List v: variable to "val".
6610  */
6611     void
6612 set_vim_var_list(int idx, list_T *val)
6613 {
6614     clear_tv(&vimvars[idx].vv_di.di_tv);
6615     vimvars[idx].vv_type = VAR_LIST;
6616     vimvars[idx].vv_list = val;
6617     if (val != NULL)
6618 	++val->lv_refcount;
6619 }
6620 
6621 /*
6622  * Set Dictionary v: variable to "val".
6623  */
6624     void
6625 set_vim_var_dict(int idx, dict_T *val)
6626 {
6627     int		todo;
6628     hashitem_T	*hi;
6629 
6630     clear_tv(&vimvars[idx].vv_di.di_tv);
6631     vimvars[idx].vv_type = VAR_DICT;
6632     vimvars[idx].vv_dict = val;
6633     if (val != NULL)
6634     {
6635 	++val->dv_refcount;
6636 
6637 	/* Set readonly */
6638 	todo = (int)val->dv_hashtab.ht_used;
6639 	for (hi = val->dv_hashtab.ht_array; todo > 0 ; ++hi)
6640 	{
6641 	    if (HASHITEM_EMPTY(hi))
6642 		continue;
6643 	    --todo;
6644 	    HI2DI(hi)->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
6645 	}
6646     }
6647 }
6648 
6649 /*
6650  * Set v:register if needed.
6651  */
6652     void
6653 set_reg_var(int c)
6654 {
6655     char_u	regname;
6656 
6657     if (c == 0 || c == ' ')
6658 	regname = '"';
6659     else
6660 	regname = c;
6661     /* Avoid free/alloc when the value is already right. */
6662     if (vimvars[VV_REG].vv_str == NULL || vimvars[VV_REG].vv_str[0] != c)
6663 	set_vim_var_string(VV_REG, &regname, 1);
6664 }
6665 
6666 /*
6667  * Get or set v:exception.  If "oldval" == NULL, return the current value.
6668  * Otherwise, restore the value to "oldval" and return NULL.
6669  * Must always be called in pairs to save and restore v:exception!  Does not
6670  * take care of memory allocations.
6671  */
6672     char_u *
6673 v_exception(char_u *oldval)
6674 {
6675     if (oldval == NULL)
6676 	return vimvars[VV_EXCEPTION].vv_str;
6677 
6678     vimvars[VV_EXCEPTION].vv_str = oldval;
6679     return NULL;
6680 }
6681 
6682 /*
6683  * Get or set v:throwpoint.  If "oldval" == NULL, return the current value.
6684  * Otherwise, restore the value to "oldval" and return NULL.
6685  * Must always be called in pairs to save and restore v:throwpoint!  Does not
6686  * take care of memory allocations.
6687  */
6688     char_u *
6689 v_throwpoint(char_u *oldval)
6690 {
6691     if (oldval == NULL)
6692 	return vimvars[VV_THROWPOINT].vv_str;
6693 
6694     vimvars[VV_THROWPOINT].vv_str = oldval;
6695     return NULL;
6696 }
6697 
6698 #if defined(FEAT_AUTOCMD) || defined(PROTO)
6699 /*
6700  * Set v:cmdarg.
6701  * If "eap" != NULL, use "eap" to generate the value and return the old value.
6702  * If "oldarg" != NULL, restore the value to "oldarg" and return NULL.
6703  * Must always be called in pairs!
6704  */
6705     char_u *
6706 set_cmdarg(exarg_T *eap, char_u *oldarg)
6707 {
6708     char_u	*oldval;
6709     char_u	*newval;
6710     unsigned	len;
6711 
6712     oldval = vimvars[VV_CMDARG].vv_str;
6713     if (eap == NULL)
6714     {
6715 	vim_free(oldval);
6716 	vimvars[VV_CMDARG].vv_str = oldarg;
6717 	return NULL;
6718     }
6719 
6720     if (eap->force_bin == FORCE_BIN)
6721 	len = 6;
6722     else if (eap->force_bin == FORCE_NOBIN)
6723 	len = 8;
6724     else
6725 	len = 0;
6726 
6727     if (eap->read_edit)
6728 	len += 7;
6729 
6730     if (eap->force_ff != 0)
6731 	len += (unsigned)STRLEN(eap->cmd + eap->force_ff) + 6;
6732 # ifdef FEAT_MBYTE
6733     if (eap->force_enc != 0)
6734 	len += (unsigned)STRLEN(eap->cmd + eap->force_enc) + 7;
6735     if (eap->bad_char != 0)
6736 	len += 7 + 4;  /* " ++bad=" + "keep" or "drop" */
6737 # endif
6738 
6739     newval = alloc(len + 1);
6740     if (newval == NULL)
6741 	return NULL;
6742 
6743     if (eap->force_bin == FORCE_BIN)
6744 	sprintf((char *)newval, " ++bin");
6745     else if (eap->force_bin == FORCE_NOBIN)
6746 	sprintf((char *)newval, " ++nobin");
6747     else
6748 	*newval = NUL;
6749 
6750     if (eap->read_edit)
6751 	STRCAT(newval, " ++edit");
6752 
6753     if (eap->force_ff != 0)
6754 	sprintf((char *)newval + STRLEN(newval), " ++ff=%s",
6755 						eap->cmd + eap->force_ff);
6756 # ifdef FEAT_MBYTE
6757     if (eap->force_enc != 0)
6758 	sprintf((char *)newval + STRLEN(newval), " ++enc=%s",
6759 					       eap->cmd + eap->force_enc);
6760     if (eap->bad_char == BAD_KEEP)
6761 	STRCPY(newval + STRLEN(newval), " ++bad=keep");
6762     else if (eap->bad_char == BAD_DROP)
6763 	STRCPY(newval + STRLEN(newval), " ++bad=drop");
6764     else if (eap->bad_char != 0)
6765 	sprintf((char *)newval + STRLEN(newval), " ++bad=%c", eap->bad_char);
6766 # endif
6767     vimvars[VV_CMDARG].vv_str = newval;
6768     return oldval;
6769 }
6770 #endif
6771 
6772 /*
6773  * Get the value of internal variable "name".
6774  * Return OK or FAIL.
6775  */
6776     int
6777 get_var_tv(
6778     char_u	*name,
6779     int		len,		/* length of "name" */
6780     typval_T	*rettv,		/* NULL when only checking existence */
6781     dictitem_T	**dip,		/* non-NULL when typval's dict item is needed */
6782     int		verbose,	/* may give error message */
6783     int		no_autoload)	/* do not use script autoloading */
6784 {
6785     int		ret = OK;
6786     typval_T	*tv = NULL;
6787     typval_T	atv;
6788     dictitem_T	*v;
6789     int		cc;
6790 
6791     /* truncate the name, so that we can use strcmp() */
6792     cc = name[len];
6793     name[len] = NUL;
6794 
6795     /*
6796      * Check for "b:changedtick".
6797      */
6798     if (STRCMP(name, "b:changedtick") == 0)
6799     {
6800 	atv.v_type = VAR_NUMBER;
6801 	atv.vval.v_number = curbuf->b_changedtick;
6802 	tv = &atv;
6803     }
6804 
6805     /*
6806      * Check for user-defined variables.
6807      */
6808     else
6809     {
6810 	v = find_var(name, NULL, no_autoload);
6811 	if (v != NULL)
6812 	{
6813 	    tv = &v->di_tv;
6814 	    if (dip != NULL)
6815 		*dip = v;
6816 	}
6817     }
6818 
6819     if (tv == NULL)
6820     {
6821 	if (rettv != NULL && verbose)
6822 	    EMSG2(_(e_undefvar), name);
6823 	ret = FAIL;
6824     }
6825     else if (rettv != NULL)
6826 	copy_tv(tv, rettv);
6827 
6828     name[len] = cc;
6829 
6830     return ret;
6831 }
6832 
6833 /*
6834  * Check if variable "name[len]" is a local variable or an argument.
6835  * If so, "*eval_lavars_used" is set to TRUE.
6836  */
6837     static void
6838 check_vars(char_u *name, int len)
6839 {
6840     int		cc;
6841     char_u	*varname;
6842     hashtab_T	*ht;
6843 
6844     if (eval_lavars_used == NULL)
6845 	return;
6846 
6847     /* truncate the name, so that we can use strcmp() */
6848     cc = name[len];
6849     name[len] = NUL;
6850 
6851     ht = find_var_ht(name, &varname);
6852     if (ht == get_funccal_local_ht() || ht == get_funccal_args_ht())
6853     {
6854 	if (find_var(name, NULL, TRUE) != NULL)
6855 	    *eval_lavars_used = TRUE;
6856     }
6857 
6858     name[len] = cc;
6859 }
6860 
6861 /*
6862  * Handle expr[expr], expr[expr:expr] subscript and .name lookup.
6863  * Also handle function call with Funcref variable: func(expr)
6864  * Can all be combined: dict.func(expr)[idx]['func'](expr)
6865  */
6866     int
6867 handle_subscript(
6868     char_u	**arg,
6869     typval_T	*rettv,
6870     int		evaluate,	/* do more than finding the end */
6871     int		verbose)	/* give error messages */
6872 {
6873     int		ret = OK;
6874     dict_T	*selfdict = NULL;
6875     char_u	*s;
6876     int		len;
6877     typval_T	functv;
6878 
6879     while (ret == OK
6880 	    && (**arg == '['
6881 		|| (**arg == '.' && rettv->v_type == VAR_DICT)
6882 		|| (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
6883 					    || rettv->v_type == VAR_PARTIAL)))
6884 	    && !vim_iswhite(*(*arg - 1)))
6885     {
6886 	if (**arg == '(')
6887 	{
6888 	    partial_T	*pt = NULL;
6889 
6890 	    /* need to copy the funcref so that we can clear rettv */
6891 	    if (evaluate)
6892 	    {
6893 		functv = *rettv;
6894 		rettv->v_type = VAR_UNKNOWN;
6895 
6896 		/* Invoke the function.  Recursive! */
6897 		if (functv.v_type == VAR_PARTIAL)
6898 		{
6899 		    pt = functv.vval.v_partial;
6900 		    s = partial_name(pt);
6901 		}
6902 		else
6903 		    s = functv.vval.v_string;
6904 	    }
6905 	    else
6906 		s = (char_u *)"";
6907 	    ret = get_func_tv(s, (int)STRLEN(s), rettv, arg,
6908 			curwin->w_cursor.lnum, curwin->w_cursor.lnum,
6909 			&len, evaluate, pt, selfdict);
6910 
6911 	    /* Clear the funcref afterwards, so that deleting it while
6912 	     * evaluating the arguments is possible (see test55). */
6913 	    if (evaluate)
6914 		clear_tv(&functv);
6915 
6916 	    /* Stop the expression evaluation when immediately aborting on
6917 	     * error, or when an interrupt occurred or an exception was thrown
6918 	     * but not caught. */
6919 	    if (aborting())
6920 	    {
6921 		if (ret == OK)
6922 		    clear_tv(rettv);
6923 		ret = FAIL;
6924 	    }
6925 	    dict_unref(selfdict);
6926 	    selfdict = NULL;
6927 	}
6928 	else /* **arg == '[' || **arg == '.' */
6929 	{
6930 	    dict_unref(selfdict);
6931 	    if (rettv->v_type == VAR_DICT)
6932 	    {
6933 		selfdict = rettv->vval.v_dict;
6934 		if (selfdict != NULL)
6935 		    ++selfdict->dv_refcount;
6936 	    }
6937 	    else
6938 		selfdict = NULL;
6939 	    if (eval_index(arg, rettv, evaluate, verbose) == FAIL)
6940 	    {
6941 		clear_tv(rettv);
6942 		ret = FAIL;
6943 	    }
6944 	}
6945     }
6946 
6947     /* Turn "dict.Func" into a partial for "Func" bound to "dict".
6948      * Don't do this when "Func" is already a partial that was bound
6949      * explicitly (pt_auto is FALSE). */
6950     if (selfdict != NULL
6951 	    && (rettv->v_type == VAR_FUNC
6952 		|| (rettv->v_type == VAR_PARTIAL
6953 		    && (rettv->vval.v_partial->pt_auto
6954 			|| rettv->vval.v_partial->pt_dict == NULL))))
6955 	selfdict = make_partial(selfdict, rettv);
6956 
6957     dict_unref(selfdict);
6958     return ret;
6959 }
6960 
6961 /*
6962  * Allocate memory for a variable type-value, and make it empty (0 or NULL
6963  * value).
6964  */
6965     typval_T *
6966 alloc_tv(void)
6967 {
6968     return (typval_T *)alloc_clear((unsigned)sizeof(typval_T));
6969 }
6970 
6971 /*
6972  * Allocate memory for a variable type-value, and assign a string to it.
6973  * The string "s" must have been allocated, it is consumed.
6974  * Return NULL for out of memory, the variable otherwise.
6975  */
6976     static typval_T *
6977 alloc_string_tv(char_u *s)
6978 {
6979     typval_T	*rettv;
6980 
6981     rettv = alloc_tv();
6982     if (rettv != NULL)
6983     {
6984 	rettv->v_type = VAR_STRING;
6985 	rettv->vval.v_string = s;
6986     }
6987     else
6988 	vim_free(s);
6989     return rettv;
6990 }
6991 
6992 /*
6993  * Free the memory for a variable type-value.
6994  */
6995     void
6996 free_tv(typval_T *varp)
6997 {
6998     if (varp != NULL)
6999     {
7000 	switch (varp->v_type)
7001 	{
7002 	    case VAR_FUNC:
7003 		func_unref(varp->vval.v_string);
7004 		/*FALLTHROUGH*/
7005 	    case VAR_STRING:
7006 		vim_free(varp->vval.v_string);
7007 		break;
7008 	    case VAR_PARTIAL:
7009 		partial_unref(varp->vval.v_partial);
7010 		break;
7011 	    case VAR_LIST:
7012 		list_unref(varp->vval.v_list);
7013 		break;
7014 	    case VAR_DICT:
7015 		dict_unref(varp->vval.v_dict);
7016 		break;
7017 	    case VAR_JOB:
7018 #ifdef FEAT_JOB_CHANNEL
7019 		job_unref(varp->vval.v_job);
7020 		break;
7021 #endif
7022 	    case VAR_CHANNEL:
7023 #ifdef FEAT_JOB_CHANNEL
7024 		channel_unref(varp->vval.v_channel);
7025 		break;
7026 #endif
7027 	    case VAR_NUMBER:
7028 	    case VAR_FLOAT:
7029 	    case VAR_UNKNOWN:
7030 	    case VAR_SPECIAL:
7031 		break;
7032 	}
7033 	vim_free(varp);
7034     }
7035 }
7036 
7037 /*
7038  * Free the memory for a variable value and set the value to NULL or 0.
7039  */
7040     void
7041 clear_tv(typval_T *varp)
7042 {
7043     if (varp != NULL)
7044     {
7045 	switch (varp->v_type)
7046 	{
7047 	    case VAR_FUNC:
7048 		func_unref(varp->vval.v_string);
7049 		/*FALLTHROUGH*/
7050 	    case VAR_STRING:
7051 		vim_free(varp->vval.v_string);
7052 		varp->vval.v_string = NULL;
7053 		break;
7054 	    case VAR_PARTIAL:
7055 		partial_unref(varp->vval.v_partial);
7056 		varp->vval.v_partial = NULL;
7057 		break;
7058 	    case VAR_LIST:
7059 		list_unref(varp->vval.v_list);
7060 		varp->vval.v_list = NULL;
7061 		break;
7062 	    case VAR_DICT:
7063 		dict_unref(varp->vval.v_dict);
7064 		varp->vval.v_dict = NULL;
7065 		break;
7066 	    case VAR_NUMBER:
7067 	    case VAR_SPECIAL:
7068 		varp->vval.v_number = 0;
7069 		break;
7070 	    case VAR_FLOAT:
7071 #ifdef FEAT_FLOAT
7072 		varp->vval.v_float = 0.0;
7073 		break;
7074 #endif
7075 	    case VAR_JOB:
7076 #ifdef FEAT_JOB_CHANNEL
7077 		job_unref(varp->vval.v_job);
7078 		varp->vval.v_job = NULL;
7079 #endif
7080 		break;
7081 	    case VAR_CHANNEL:
7082 #ifdef FEAT_JOB_CHANNEL
7083 		channel_unref(varp->vval.v_channel);
7084 		varp->vval.v_channel = NULL;
7085 #endif
7086 	    case VAR_UNKNOWN:
7087 		break;
7088 	}
7089 	varp->v_lock = 0;
7090     }
7091 }
7092 
7093 /*
7094  * Set the value of a variable to NULL without freeing items.
7095  */
7096     void
7097 init_tv(typval_T *varp)
7098 {
7099     if (varp != NULL)
7100 	vim_memset(varp, 0, sizeof(typval_T));
7101 }
7102 
7103 /*
7104  * Get the number value of a variable.
7105  * If it is a String variable, uses vim_str2nr().
7106  * For incompatible types, return 0.
7107  * get_tv_number_chk() is similar to get_tv_number(), but informs the
7108  * caller of incompatible types: it sets *denote to TRUE if "denote"
7109  * is not NULL or returns -1 otherwise.
7110  */
7111     varnumber_T
7112 get_tv_number(typval_T *varp)
7113 {
7114     int		error = FALSE;
7115 
7116     return get_tv_number_chk(varp, &error);	/* return 0L on error */
7117 }
7118 
7119     varnumber_T
7120 get_tv_number_chk(typval_T *varp, int *denote)
7121 {
7122     varnumber_T	n = 0L;
7123 
7124     switch (varp->v_type)
7125     {
7126 	case VAR_NUMBER:
7127 	    return varp->vval.v_number;
7128 	case VAR_FLOAT:
7129 #ifdef FEAT_FLOAT
7130 	    EMSG(_("E805: Using a Float as a Number"));
7131 	    break;
7132 #endif
7133 	case VAR_FUNC:
7134 	case VAR_PARTIAL:
7135 	    EMSG(_("E703: Using a Funcref as a Number"));
7136 	    break;
7137 	case VAR_STRING:
7138 	    if (varp->vval.v_string != NULL)
7139 		vim_str2nr(varp->vval.v_string, NULL, NULL,
7140 						    STR2NR_ALL, &n, NULL, 0);
7141 	    return n;
7142 	case VAR_LIST:
7143 	    EMSG(_("E745: Using a List as a Number"));
7144 	    break;
7145 	case VAR_DICT:
7146 	    EMSG(_("E728: Using a Dictionary as a Number"));
7147 	    break;
7148 	case VAR_SPECIAL:
7149 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
7150 	    break;
7151 	case VAR_JOB:
7152 #ifdef FEAT_JOB_CHANNEL
7153 	    EMSG(_("E910: Using a Job as a Number"));
7154 	    break;
7155 #endif
7156 	case VAR_CHANNEL:
7157 #ifdef FEAT_JOB_CHANNEL
7158 	    EMSG(_("E913: Using a Channel as a Number"));
7159 	    break;
7160 #endif
7161 	case VAR_UNKNOWN:
7162 	    internal_error("get_tv_number(UNKNOWN)");
7163 	    break;
7164     }
7165     if (denote == NULL)		/* useful for values that must be unsigned */
7166 	n = -1;
7167     else
7168 	*denote = TRUE;
7169     return n;
7170 }
7171 
7172 #ifdef FEAT_FLOAT
7173     float_T
7174 get_tv_float(typval_T *varp)
7175 {
7176     switch (varp->v_type)
7177     {
7178 	case VAR_NUMBER:
7179 	    return (float_T)(varp->vval.v_number);
7180 	case VAR_FLOAT:
7181 	    return varp->vval.v_float;
7182 	case VAR_FUNC:
7183 	case VAR_PARTIAL:
7184 	    EMSG(_("E891: Using a Funcref as a Float"));
7185 	    break;
7186 	case VAR_STRING:
7187 	    EMSG(_("E892: Using a String as a Float"));
7188 	    break;
7189 	case VAR_LIST:
7190 	    EMSG(_("E893: Using a List as a Float"));
7191 	    break;
7192 	case VAR_DICT:
7193 	    EMSG(_("E894: Using a Dictionary as a Float"));
7194 	    break;
7195 	case VAR_SPECIAL:
7196 	    EMSG(_("E907: Using a special value as a Float"));
7197 	    break;
7198 	case VAR_JOB:
7199 # ifdef FEAT_JOB_CHANNEL
7200 	    EMSG(_("E911: Using a Job as a Float"));
7201 	    break;
7202 # endif
7203 	case VAR_CHANNEL:
7204 # ifdef FEAT_JOB_CHANNEL
7205 	    EMSG(_("E914: Using a Channel as a Float"));
7206 	    break;
7207 # endif
7208 	case VAR_UNKNOWN:
7209 	    internal_error("get_tv_float(UNKNOWN)");
7210 	    break;
7211     }
7212     return 0;
7213 }
7214 #endif
7215 
7216 /*
7217  * Get the string value of a variable.
7218  * If it is a Number variable, the number is converted into a string.
7219  * get_tv_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7220  * get_tv_string_buf() uses a given buffer.
7221  * If the String variable has never been set, return an empty string.
7222  * Never returns NULL;
7223  * get_tv_string_chk() and get_tv_string_buf_chk() are similar, but return
7224  * NULL on error.
7225  */
7226     char_u *
7227 get_tv_string(typval_T *varp)
7228 {
7229     static char_u   mybuf[NUMBUFLEN];
7230 
7231     return get_tv_string_buf(varp, mybuf);
7232 }
7233 
7234     char_u *
7235 get_tv_string_buf(typval_T *varp, char_u *buf)
7236 {
7237     char_u	*res =  get_tv_string_buf_chk(varp, buf);
7238 
7239     return res != NULL ? res : (char_u *)"";
7240 }
7241 
7242 /*
7243  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7244  */
7245     char_u *
7246 get_tv_string_chk(typval_T *varp)
7247 {
7248     static char_u   mybuf[NUMBUFLEN];
7249 
7250     return get_tv_string_buf_chk(varp, mybuf);
7251 }
7252 
7253     char_u *
7254 get_tv_string_buf_chk(typval_T *varp, char_u *buf)
7255 {
7256     switch (varp->v_type)
7257     {
7258 	case VAR_NUMBER:
7259 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
7260 					    (varnumber_T)varp->vval.v_number);
7261 	    return buf;
7262 	case VAR_FUNC:
7263 	case VAR_PARTIAL:
7264 	    EMSG(_("E729: using Funcref as a String"));
7265 	    break;
7266 	case VAR_LIST:
7267 	    EMSG(_("E730: using List as a String"));
7268 	    break;
7269 	case VAR_DICT:
7270 	    EMSG(_("E731: using Dictionary as a String"));
7271 	    break;
7272 	case VAR_FLOAT:
7273 #ifdef FEAT_FLOAT
7274 	    EMSG(_(e_float_as_string));
7275 	    break;
7276 #endif
7277 	case VAR_STRING:
7278 	    if (varp->vval.v_string != NULL)
7279 		return varp->vval.v_string;
7280 	    return (char_u *)"";
7281 	case VAR_SPECIAL:
7282 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
7283 	    return buf;
7284 	case VAR_JOB:
7285 #ifdef FEAT_JOB_CHANNEL
7286 	    {
7287 		job_T *job = varp->vval.v_job;
7288 		char  *status;
7289 
7290 		if (job == NULL)
7291 		    return (char_u *)"no process";
7292 		status = job->jv_status == JOB_FAILED ? "fail"
7293 				: job->jv_status >= JOB_ENDED ? "dead"
7294 				: "run";
7295 # ifdef UNIX
7296 		vim_snprintf((char *)buf, NUMBUFLEN,
7297 			    "process %ld %s", (long)job->jv_pid, status);
7298 # elif defined(WIN32)
7299 		vim_snprintf((char *)buf, NUMBUFLEN,
7300 			    "process %ld %s",
7301 			    (long)job->jv_proc_info.dwProcessId,
7302 			    status);
7303 # else
7304 		/* fall-back */
7305 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
7306 # endif
7307 		return buf;
7308 	    }
7309 #endif
7310 	    break;
7311 	case VAR_CHANNEL:
7312 #ifdef FEAT_JOB_CHANNEL
7313 	    {
7314 		channel_T *channel = varp->vval.v_channel;
7315 		char      *status = channel_status(channel, -1);
7316 
7317 		if (channel == NULL)
7318 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
7319 		else
7320 		    vim_snprintf((char *)buf, NUMBUFLEN,
7321 				     "channel %d %s", channel->ch_id, status);
7322 		return buf;
7323 	    }
7324 #endif
7325 	    break;
7326 	case VAR_UNKNOWN:
7327 	    EMSG(_("E908: using an invalid value as a String"));
7328 	    break;
7329     }
7330     return NULL;
7331 }
7332 
7333 /*
7334  * Find variable "name" in the list of variables.
7335  * Return a pointer to it if found, NULL if not found.
7336  * Careful: "a:0" variables don't have a name.
7337  * When "htp" is not NULL we are writing to the variable, set "htp" to the
7338  * hashtab_T used.
7339  */
7340     dictitem_T *
7341 find_var(char_u *name, hashtab_T **htp, int no_autoload)
7342 {
7343     char_u	*varname;
7344     hashtab_T	*ht;
7345     dictitem_T	*ret = NULL;
7346 
7347     ht = find_var_ht(name, &varname);
7348     if (htp != NULL)
7349 	*htp = ht;
7350     if (ht == NULL)
7351 	return NULL;
7352     ret = find_var_in_ht(ht, *name, varname, no_autoload || htp != NULL);
7353     if (ret != NULL)
7354 	return ret;
7355 
7356     /* Search in parent scope for lambda */
7357     return find_var_in_scoped_ht(name, no_autoload || htp != NULL);
7358 }
7359 
7360 /*
7361  * Find variable "varname" in hashtab "ht" with name "htname".
7362  * Returns NULL if not found.
7363  */
7364     dictitem_T *
7365 find_var_in_ht(
7366     hashtab_T	*ht,
7367     int		htname,
7368     char_u	*varname,
7369     int		no_autoload)
7370 {
7371     hashitem_T	*hi;
7372 
7373     if (*varname == NUL)
7374     {
7375 	/* Must be something like "s:", otherwise "ht" would be NULL. */
7376 	switch (htname)
7377 	{
7378 	    case 's': return &SCRIPT_SV(current_SID)->sv_var;
7379 	    case 'g': return &globvars_var;
7380 	    case 'v': return &vimvars_var;
7381 	    case 'b': return &curbuf->b_bufvar;
7382 	    case 'w': return &curwin->w_winvar;
7383 #ifdef FEAT_WINDOWS
7384 	    case 't': return &curtab->tp_winvar;
7385 #endif
7386 	    case 'l': return get_funccal_local_var();
7387 	    case 'a': return get_funccal_args_var();
7388 	}
7389 	return NULL;
7390     }
7391 
7392     hi = hash_find(ht, varname);
7393     if (HASHITEM_EMPTY(hi))
7394     {
7395 	/* For global variables we may try auto-loading the script.  If it
7396 	 * worked find the variable again.  Don't auto-load a script if it was
7397 	 * loaded already, otherwise it would be loaded every time when
7398 	 * checking if a function name is a Funcref variable. */
7399 	if (ht == &globvarht && !no_autoload)
7400 	{
7401 	    /* Note: script_autoload() may make "hi" invalid. It must either
7402 	     * be obtained again or not used. */
7403 	    if (!script_autoload(varname, FALSE) || aborting())
7404 		return NULL;
7405 	    hi = hash_find(ht, varname);
7406 	}
7407 	if (HASHITEM_EMPTY(hi))
7408 	    return NULL;
7409     }
7410     return HI2DI(hi);
7411 }
7412 
7413 /*
7414  * Find the hashtab used for a variable name.
7415  * Return NULL if the name is not valid.
7416  * Set "varname" to the start of name without ':'.
7417  */
7418     hashtab_T *
7419 find_var_ht(char_u *name, char_u **varname)
7420 {
7421     hashitem_T	*hi;
7422     hashtab_T	*ht;
7423 
7424     if (name[0] == NUL)
7425 	return NULL;
7426     if (name[1] != ':')
7427     {
7428 	/* The name must not start with a colon or #. */
7429 	if (name[0] == ':' || name[0] == AUTOLOAD_CHAR)
7430 	    return NULL;
7431 	*varname = name;
7432 
7433 	/* "version" is "v:version" in all scopes */
7434 	hi = hash_find(&compat_hashtab, name);
7435 	if (!HASHITEM_EMPTY(hi))
7436 	    return &compat_hashtab;
7437 
7438 	ht = get_funccal_local_ht();
7439 	if (ht == NULL)
7440 	    return &globvarht;			/* global variable */
7441 	return ht;				/* local variable */
7442     }
7443     *varname = name + 2;
7444     if (*name == 'g')				/* global variable */
7445 	return &globvarht;
7446     /* There must be no ':' or '#' in the rest of the name, unless g: is used
7447      */
7448     if (vim_strchr(name + 2, ':') != NULL
7449 			       || vim_strchr(name + 2, AUTOLOAD_CHAR) != NULL)
7450 	return NULL;
7451     if (*name == 'b')				/* buffer variable */
7452 	return &curbuf->b_vars->dv_hashtab;
7453     if (*name == 'w')				/* window variable */
7454 	return &curwin->w_vars->dv_hashtab;
7455 #ifdef FEAT_WINDOWS
7456     if (*name == 't')				/* tab page variable */
7457 	return &curtab->tp_vars->dv_hashtab;
7458 #endif
7459     if (*name == 'v')				/* v: variable */
7460 	return &vimvarht;
7461     if (*name == 'a')				/* a: function argument */
7462 	return get_funccal_args_ht();
7463     if (*name == 'l')				/* l: local function variable */
7464 	return get_funccal_local_ht();
7465     if (*name == 's'				/* script variable */
7466 	    && current_SID > 0 && current_SID <= ga_scripts.ga_len)
7467 	return &SCRIPT_VARS(current_SID);
7468     return NULL;
7469 }
7470 
7471 /*
7472  * Get the string value of a (global/local) variable.
7473  * Note: see get_tv_string() for how long the pointer remains valid.
7474  * Returns NULL when it doesn't exist.
7475  */
7476     char_u *
7477 get_var_value(char_u *name)
7478 {
7479     dictitem_T	*v;
7480 
7481     v = find_var(name, NULL, FALSE);
7482     if (v == NULL)
7483 	return NULL;
7484     return get_tv_string(&v->di_tv);
7485 }
7486 
7487 /*
7488  * Allocate a new hashtab for a sourced script.  It will be used while
7489  * sourcing this script and when executing functions defined in the script.
7490  */
7491     void
7492 new_script_vars(scid_T id)
7493 {
7494     int		i;
7495     hashtab_T	*ht;
7496     scriptvar_T *sv;
7497 
7498     if (ga_grow(&ga_scripts, (int)(id - ga_scripts.ga_len)) == OK)
7499     {
7500 	/* Re-allocating ga_data means that an ht_array pointing to
7501 	 * ht_smallarray becomes invalid.  We can recognize this: ht_mask is
7502 	 * at its init value.  Also reset "v_dict", it's always the same. */
7503 	for (i = 1; i <= ga_scripts.ga_len; ++i)
7504 	{
7505 	    ht = &SCRIPT_VARS(i);
7506 	    if (ht->ht_mask == HT_INIT_SIZE - 1)
7507 		ht->ht_array = ht->ht_smallarray;
7508 	    sv = SCRIPT_SV(i);
7509 	    sv->sv_var.di_tv.vval.v_dict = &sv->sv_dict;
7510 	}
7511 
7512 	while (ga_scripts.ga_len < id)
7513 	{
7514 	    sv = SCRIPT_SV(ga_scripts.ga_len + 1) =
7515 		(scriptvar_T *)alloc_clear(sizeof(scriptvar_T));
7516 	    init_var_dict(&sv->sv_dict, &sv->sv_var, VAR_SCOPE);
7517 	    ++ga_scripts.ga_len;
7518 	}
7519     }
7520 }
7521 
7522 /*
7523  * Initialize dictionary "dict" as a scope and set variable "dict_var" to
7524  * point to it.
7525  */
7526     void
7527 init_var_dict(dict_T *dict, dictitem_T *dict_var, int scope)
7528 {
7529     hash_init(&dict->dv_hashtab);
7530     dict->dv_lock = 0;
7531     dict->dv_scope = scope;
7532     dict->dv_refcount = DO_NOT_FREE_CNT;
7533     dict->dv_copyID = 0;
7534     dict_var->di_tv.vval.v_dict = dict;
7535     dict_var->di_tv.v_type = VAR_DICT;
7536     dict_var->di_tv.v_lock = VAR_FIXED;
7537     dict_var->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
7538     dict_var->di_key[0] = NUL;
7539 }
7540 
7541 /*
7542  * Unreference a dictionary initialized by init_var_dict().
7543  */
7544     void
7545 unref_var_dict(dict_T *dict)
7546 {
7547     /* Now the dict needs to be freed if no one else is using it, go back to
7548      * normal reference counting. */
7549     dict->dv_refcount -= DO_NOT_FREE_CNT - 1;
7550     dict_unref(dict);
7551 }
7552 
7553 /*
7554  * Clean up a list of internal variables.
7555  * Frees all allocated variables and the value they contain.
7556  * Clears hashtab "ht", does not free it.
7557  */
7558     void
7559 vars_clear(hashtab_T *ht)
7560 {
7561     vars_clear_ext(ht, TRUE);
7562 }
7563 
7564 /*
7565  * Like vars_clear(), but only free the value if "free_val" is TRUE.
7566  */
7567     void
7568 vars_clear_ext(hashtab_T *ht, int free_val)
7569 {
7570     int		todo;
7571     hashitem_T	*hi;
7572     dictitem_T	*v;
7573 
7574     hash_lock(ht);
7575     todo = (int)ht->ht_used;
7576     for (hi = ht->ht_array; todo > 0; ++hi)
7577     {
7578 	if (!HASHITEM_EMPTY(hi))
7579 	{
7580 	    --todo;
7581 
7582 	    /* Free the variable.  Don't remove it from the hashtab,
7583 	     * ht_array might change then.  hash_clear() takes care of it
7584 	     * later. */
7585 	    v = HI2DI(hi);
7586 	    if (free_val)
7587 		clear_tv(&v->di_tv);
7588 	    if (v->di_flags & DI_FLAGS_ALLOC)
7589 		vim_free(v);
7590 	}
7591     }
7592     hash_clear(ht);
7593     ht->ht_used = 0;
7594 }
7595 
7596 /*
7597  * Delete a variable from hashtab "ht" at item "hi".
7598  * Clear the variable value and free the dictitem.
7599  */
7600     static void
7601 delete_var(hashtab_T *ht, hashitem_T *hi)
7602 {
7603     dictitem_T	*di = HI2DI(hi);
7604 
7605     hash_remove(ht, hi);
7606     clear_tv(&di->di_tv);
7607     vim_free(di);
7608 }
7609 
7610 /*
7611  * List the value of one internal variable.
7612  */
7613     static void
7614 list_one_var(dictitem_T *v, char_u *prefix, int *first)
7615 {
7616     char_u	*tofree;
7617     char_u	*s;
7618     char_u	numbuf[NUMBUFLEN];
7619 
7620     s = echo_string(&v->di_tv, &tofree, numbuf, get_copyID());
7621     list_one_var_a(prefix, v->di_key, v->di_tv.v_type,
7622 					 s == NULL ? (char_u *)"" : s, first);
7623     vim_free(tofree);
7624 }
7625 
7626     static void
7627 list_one_var_a(
7628     char_u	*prefix,
7629     char_u	*name,
7630     int		type,
7631     char_u	*string,
7632     int		*first)  /* when TRUE clear rest of screen and set to FALSE */
7633 {
7634     /* don't use msg() or msg_attr() to avoid overwriting "v:statusmsg" */
7635     msg_start();
7636     msg_puts(prefix);
7637     if (name != NULL)	/* "a:" vars don't have a name stored */
7638 	msg_puts(name);
7639     msg_putchar(' ');
7640     msg_advance(22);
7641     if (type == VAR_NUMBER)
7642 	msg_putchar('#');
7643     else if (type == VAR_FUNC || type == VAR_PARTIAL)
7644 	msg_putchar('*');
7645     else if (type == VAR_LIST)
7646     {
7647 	msg_putchar('[');
7648 	if (*string == '[')
7649 	    ++string;
7650     }
7651     else if (type == VAR_DICT)
7652     {
7653 	msg_putchar('{');
7654 	if (*string == '{')
7655 	    ++string;
7656     }
7657     else
7658 	msg_putchar(' ');
7659 
7660     msg_outtrans(string);
7661 
7662     if (type == VAR_FUNC || type == VAR_PARTIAL)
7663 	msg_puts((char_u *)"()");
7664     if (*first)
7665     {
7666 	msg_clr_eos();
7667 	*first = FALSE;
7668     }
7669 }
7670 
7671 /*
7672  * Set variable "name" to value in "tv".
7673  * If the variable already exists, the value is updated.
7674  * Otherwise the variable is created.
7675  */
7676     void
7677 set_var(
7678     char_u	*name,
7679     typval_T	*tv,
7680     int		copy)	    /* make copy of value in "tv" */
7681 {
7682     dictitem_T	*v;
7683     char_u	*varname;
7684     hashtab_T	*ht;
7685 
7686     ht = find_var_ht(name, &varname);
7687     if (ht == NULL || *varname == NUL)
7688     {
7689 	EMSG2(_(e_illvar), name);
7690 	return;
7691     }
7692     v = find_var_in_ht(ht, 0, varname, TRUE);
7693 
7694     /* Search in parent scope which is possible to reference from lambda */
7695     if (v == NULL)
7696 	v = find_var_in_scoped_ht(name, TRUE);
7697 
7698     if ((tv->v_type == VAR_FUNC || tv->v_type == VAR_PARTIAL)
7699 				      && var_check_func_name(name, v == NULL))
7700 	return;
7701 
7702     if (v != NULL)
7703     {
7704 	/* existing variable, need to clear the value */
7705 	if (var_check_ro(v->di_flags, name, FALSE)
7706 			       || tv_check_lock(v->di_tv.v_lock, name, FALSE))
7707 	    return;
7708 
7709 	/*
7710 	 * Handle setting internal v: variables separately where needed to
7711 	 * prevent changing the type.
7712 	 */
7713 	if (ht == &vimvarht)
7714 	{
7715 	    if (v->di_tv.v_type == VAR_STRING)
7716 	    {
7717 		vim_free(v->di_tv.vval.v_string);
7718 		if (copy || tv->v_type != VAR_STRING)
7719 		    v->di_tv.vval.v_string = vim_strsave(get_tv_string(tv));
7720 		else
7721 		{
7722 		    /* Take over the string to avoid an extra alloc/free. */
7723 		    v->di_tv.vval.v_string = tv->vval.v_string;
7724 		    tv->vval.v_string = NULL;
7725 		}
7726 		return;
7727 	    }
7728 	    else if (v->di_tv.v_type == VAR_NUMBER)
7729 	    {
7730 		v->di_tv.vval.v_number = get_tv_number(tv);
7731 		if (STRCMP(varname, "searchforward") == 0)
7732 		    set_search_direction(v->di_tv.vval.v_number ? '/' : '?');
7733 #ifdef FEAT_SEARCH_EXTRA
7734 		else if (STRCMP(varname, "hlsearch") == 0)
7735 		{
7736 		    no_hlsearch = !v->di_tv.vval.v_number;
7737 		    redraw_all_later(SOME_VALID);
7738 		}
7739 #endif
7740 		return;
7741 	    }
7742 	    else if (v->di_tv.v_type != tv->v_type)
7743 		internal_error("set_var()");
7744 	}
7745 
7746 	clear_tv(&v->di_tv);
7747     }
7748     else		    /* add a new variable */
7749     {
7750 	/* Can't add "v:" variable. */
7751 	if (ht == &vimvarht)
7752 	{
7753 	    EMSG2(_(e_illvar), name);
7754 	    return;
7755 	}
7756 
7757 	/* Make sure the variable name is valid. */
7758 	if (!valid_varname(varname))
7759 	    return;
7760 
7761 	v = (dictitem_T *)alloc((unsigned)(sizeof(dictitem_T)
7762 							  + STRLEN(varname)));
7763 	if (v == NULL)
7764 	    return;
7765 	STRCPY(v->di_key, varname);
7766 	if (hash_add(ht, DI2HIKEY(v)) == FAIL)
7767 	{
7768 	    vim_free(v);
7769 	    return;
7770 	}
7771 	v->di_flags = DI_FLAGS_ALLOC;
7772     }
7773 
7774     if (copy || tv->v_type == VAR_NUMBER || tv->v_type == VAR_FLOAT)
7775 	copy_tv(tv, &v->di_tv);
7776     else
7777     {
7778 	v->di_tv = *tv;
7779 	v->di_tv.v_lock = 0;
7780 	init_tv(tv);
7781     }
7782 }
7783 
7784 /*
7785  * Return TRUE if di_flags "flags" indicates variable "name" is read-only.
7786  * Also give an error message.
7787  */
7788     int
7789 var_check_ro(int flags, char_u *name, int use_gettext)
7790 {
7791     if (flags & DI_FLAGS_RO)
7792     {
7793 	EMSG2(_(e_readonlyvar), use_gettext ? (char_u *)_(name) : name);
7794 	return TRUE;
7795     }
7796     if ((flags & DI_FLAGS_RO_SBX) && sandbox)
7797     {
7798 	EMSG2(_(e_readonlysbx), use_gettext ? (char_u *)_(name) : name);
7799 	return TRUE;
7800     }
7801     return FALSE;
7802 }
7803 
7804 /*
7805  * Return TRUE if di_flags "flags" indicates variable "name" is fixed.
7806  * Also give an error message.
7807  */
7808     int
7809 var_check_fixed(int flags, char_u *name, int use_gettext)
7810 {
7811     if (flags & DI_FLAGS_FIX)
7812     {
7813 	EMSG2(_("E795: Cannot delete variable %s"),
7814 				      use_gettext ? (char_u *)_(name) : name);
7815 	return TRUE;
7816     }
7817     return FALSE;
7818 }
7819 
7820 /*
7821  * Check if a funcref is assigned to a valid variable name.
7822  * Return TRUE and give an error if not.
7823  */
7824     int
7825 var_check_func_name(
7826     char_u *name,    /* points to start of variable name */
7827     int    new_var)  /* TRUE when creating the variable */
7828 {
7829     /* Allow for w: b: s: and t:. */
7830     if (!(vim_strchr((char_u *)"wbst", name[0]) != NULL && name[1] == ':')
7831 	    && !ASCII_ISUPPER((name[0] != NUL && name[1] == ':')
7832 						     ? name[2] : name[0]))
7833     {
7834 	EMSG2(_("E704: Funcref variable name must start with a capital: %s"),
7835 									name);
7836 	return TRUE;
7837     }
7838     /* Don't allow hiding a function.  When "v" is not NULL we might be
7839      * assigning another function to the same var, the type is checked
7840      * below. */
7841     if (new_var && function_exists(name, FALSE))
7842     {
7843 	EMSG2(_("E705: Variable name conflicts with existing function: %s"),
7844 								    name);
7845 	return TRUE;
7846     }
7847     return FALSE;
7848 }
7849 
7850 /*
7851  * Check if a variable name is valid.
7852  * Return FALSE and give an error if not.
7853  */
7854     int
7855 valid_varname(char_u *varname)
7856 {
7857     char_u *p;
7858 
7859     for (p = varname; *p != NUL; ++p)
7860 	if (!eval_isnamec1(*p) && (p == varname || !VIM_ISDIGIT(*p))
7861 						   && *p != AUTOLOAD_CHAR)
7862 	{
7863 	    EMSG2(_(e_illvar), varname);
7864 	    return FALSE;
7865 	}
7866     return TRUE;
7867 }
7868 
7869 /*
7870  * Return TRUE if typeval "tv" is set to be locked (immutable).
7871  * Also give an error message, using "name" or _("name") when use_gettext is
7872  * TRUE.
7873  */
7874     int
7875 tv_check_lock(int lock, char_u *name, int use_gettext)
7876 {
7877     if (lock & VAR_LOCKED)
7878     {
7879 	EMSG2(_("E741: Value is locked: %s"),
7880 				name == NULL ? (char_u *)_("Unknown")
7881 					     : use_gettext ? (char_u *)_(name)
7882 					     : name);
7883 	return TRUE;
7884     }
7885     if (lock & VAR_FIXED)
7886     {
7887 	EMSG2(_("E742: Cannot change value of %s"),
7888 				name == NULL ? (char_u *)_("Unknown")
7889 					     : use_gettext ? (char_u *)_(name)
7890 					     : name);
7891 	return TRUE;
7892     }
7893     return FALSE;
7894 }
7895 
7896 /*
7897  * Copy the values from typval_T "from" to typval_T "to".
7898  * When needed allocates string or increases reference count.
7899  * Does not make a copy of a list or dict but copies the reference!
7900  * It is OK for "from" and "to" to point to the same item.  This is used to
7901  * make a copy later.
7902  */
7903     void
7904 copy_tv(typval_T *from, typval_T *to)
7905 {
7906     to->v_type = from->v_type;
7907     to->v_lock = 0;
7908     switch (from->v_type)
7909     {
7910 	case VAR_NUMBER:
7911 	case VAR_SPECIAL:
7912 	    to->vval.v_number = from->vval.v_number;
7913 	    break;
7914 	case VAR_FLOAT:
7915 #ifdef FEAT_FLOAT
7916 	    to->vval.v_float = from->vval.v_float;
7917 	    break;
7918 #endif
7919 	case VAR_JOB:
7920 #ifdef FEAT_JOB_CHANNEL
7921 	    to->vval.v_job = from->vval.v_job;
7922 	    if (to->vval.v_job != NULL)
7923 		++to->vval.v_job->jv_refcount;
7924 	    break;
7925 #endif
7926 	case VAR_CHANNEL:
7927 #ifdef FEAT_JOB_CHANNEL
7928 	    to->vval.v_channel = from->vval.v_channel;
7929 	    if (to->vval.v_channel != NULL)
7930 		++to->vval.v_channel->ch_refcount;
7931 	    break;
7932 #endif
7933 	case VAR_STRING:
7934 	case VAR_FUNC:
7935 	    if (from->vval.v_string == NULL)
7936 		to->vval.v_string = NULL;
7937 	    else
7938 	    {
7939 		to->vval.v_string = vim_strsave(from->vval.v_string);
7940 		if (from->v_type == VAR_FUNC)
7941 		    func_ref(to->vval.v_string);
7942 	    }
7943 	    break;
7944 	case VAR_PARTIAL:
7945 	    if (from->vval.v_partial == NULL)
7946 		to->vval.v_partial = NULL;
7947 	    else
7948 	    {
7949 		to->vval.v_partial = from->vval.v_partial;
7950 		++to->vval.v_partial->pt_refcount;
7951 	    }
7952 	    break;
7953 	case VAR_LIST:
7954 	    if (from->vval.v_list == NULL)
7955 		to->vval.v_list = NULL;
7956 	    else
7957 	    {
7958 		to->vval.v_list = from->vval.v_list;
7959 		++to->vval.v_list->lv_refcount;
7960 	    }
7961 	    break;
7962 	case VAR_DICT:
7963 	    if (from->vval.v_dict == NULL)
7964 		to->vval.v_dict = NULL;
7965 	    else
7966 	    {
7967 		to->vval.v_dict = from->vval.v_dict;
7968 		++to->vval.v_dict->dv_refcount;
7969 	    }
7970 	    break;
7971 	case VAR_UNKNOWN:
7972 	    internal_error("copy_tv(UNKNOWN)");
7973 	    break;
7974     }
7975 }
7976 
7977 /*
7978  * Make a copy of an item.
7979  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
7980  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
7981  * reference to an already copied list/dict can be used.
7982  * Returns FAIL or OK.
7983  */
7984     int
7985 item_copy(
7986     typval_T	*from,
7987     typval_T	*to,
7988     int		deep,
7989     int		copyID)
7990 {
7991     static int	recurse = 0;
7992     int		ret = OK;
7993 
7994     if (recurse >= DICT_MAXNEST)
7995     {
7996 	EMSG(_("E698: variable nested too deep for making a copy"));
7997 	return FAIL;
7998     }
7999     ++recurse;
8000 
8001     switch (from->v_type)
8002     {
8003 	case VAR_NUMBER:
8004 	case VAR_FLOAT:
8005 	case VAR_STRING:
8006 	case VAR_FUNC:
8007 	case VAR_PARTIAL:
8008 	case VAR_SPECIAL:
8009 	case VAR_JOB:
8010 	case VAR_CHANNEL:
8011 	    copy_tv(from, to);
8012 	    break;
8013 	case VAR_LIST:
8014 	    to->v_type = VAR_LIST;
8015 	    to->v_lock = 0;
8016 	    if (from->vval.v_list == NULL)
8017 		to->vval.v_list = NULL;
8018 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
8019 	    {
8020 		/* use the copy made earlier */
8021 		to->vval.v_list = from->vval.v_list->lv_copylist;
8022 		++to->vval.v_list->lv_refcount;
8023 	    }
8024 	    else
8025 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
8026 	    if (to->vval.v_list == NULL)
8027 		ret = FAIL;
8028 	    break;
8029 	case VAR_DICT:
8030 	    to->v_type = VAR_DICT;
8031 	    to->v_lock = 0;
8032 	    if (from->vval.v_dict == NULL)
8033 		to->vval.v_dict = NULL;
8034 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
8035 	    {
8036 		/* use the copy made earlier */
8037 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
8038 		++to->vval.v_dict->dv_refcount;
8039 	    }
8040 	    else
8041 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
8042 	    if (to->vval.v_dict == NULL)
8043 		ret = FAIL;
8044 	    break;
8045 	case VAR_UNKNOWN:
8046 	    internal_error("item_copy(UNKNOWN)");
8047 	    ret = FAIL;
8048     }
8049     --recurse;
8050     return ret;
8051 }
8052 
8053 /*
8054  * This function is used by f_input() and f_inputdialog() functions. The third
8055  * argument to f_input() specifies the type of completion to use at the
8056  * prompt. The third argument to f_inputdialog() specifies the value to return
8057  * when the user cancels the prompt.
8058  */
8059     void
8060 get_user_input(
8061     typval_T	*argvars,
8062     typval_T	*rettv,
8063     int		inputdialog,
8064     int		secret)
8065 {
8066     char_u	*prompt = get_tv_string_chk(&argvars[0]);
8067     char_u	*p = NULL;
8068     int		c;
8069     char_u	buf[NUMBUFLEN];
8070     int		cmd_silent_save = cmd_silent;
8071     char_u	*defstr = (char_u *)"";
8072     int		xp_type = EXPAND_NOTHING;
8073     char_u	*xp_arg = NULL;
8074 
8075     rettv->v_type = VAR_STRING;
8076     rettv->vval.v_string = NULL;
8077 
8078 #ifdef NO_CONSOLE_INPUT
8079     /* While starting up, there is no place to enter text. */
8080     if (no_console_input())
8081 	return;
8082 #endif
8083 
8084     cmd_silent = FALSE;		/* Want to see the prompt. */
8085     if (prompt != NULL)
8086     {
8087 	/* Only the part of the message after the last NL is considered as
8088 	 * prompt for the command line */
8089 	p = vim_strrchr(prompt, '\n');
8090 	if (p == NULL)
8091 	    p = prompt;
8092 	else
8093 	{
8094 	    ++p;
8095 	    c = *p;
8096 	    *p = NUL;
8097 	    msg_start();
8098 	    msg_clr_eos();
8099 	    msg_puts_attr(prompt, echo_attr);
8100 	    msg_didout = FALSE;
8101 	    msg_starthere();
8102 	    *p = c;
8103 	}
8104 	cmdline_row = msg_row;
8105 
8106 	if (argvars[1].v_type != VAR_UNKNOWN)
8107 	{
8108 	    defstr = get_tv_string_buf_chk(&argvars[1], buf);
8109 	    if (defstr != NULL)
8110 		stuffReadbuffSpec(defstr);
8111 
8112 	    if (!inputdialog && argvars[2].v_type != VAR_UNKNOWN)
8113 	    {
8114 		char_u	*xp_name;
8115 		int	xp_namelen;
8116 		long	argt;
8117 
8118 		/* input() with a third argument: completion */
8119 		rettv->vval.v_string = NULL;
8120 
8121 		xp_name = get_tv_string_buf_chk(&argvars[2], buf);
8122 		if (xp_name == NULL)
8123 		    return;
8124 
8125 		xp_namelen = (int)STRLEN(xp_name);
8126 
8127 		if (parse_compl_arg(xp_name, xp_namelen, &xp_type, &argt,
8128 							     &xp_arg) == FAIL)
8129 		    return;
8130 	    }
8131 	}
8132 
8133 	if (defstr != NULL)
8134 	{
8135 	    int save_ex_normal_busy = ex_normal_busy;
8136 	    ex_normal_busy = 0;
8137 	    rettv->vval.v_string =
8138 		getcmdline_prompt(secret ? NUL : '@', p, echo_attr,
8139 							      xp_type, xp_arg);
8140 	    ex_normal_busy = save_ex_normal_busy;
8141 	}
8142 	if (inputdialog && rettv->vval.v_string == NULL
8143 		&& argvars[1].v_type != VAR_UNKNOWN
8144 		&& argvars[2].v_type != VAR_UNKNOWN)
8145 	    rettv->vval.v_string = vim_strsave(get_tv_string_buf(
8146 							   &argvars[2], buf));
8147 
8148 	vim_free(xp_arg);
8149 
8150 	/* since the user typed this, no need to wait for return */
8151 	need_wait_return = FALSE;
8152 	msg_didout = FALSE;
8153     }
8154     cmd_silent = cmd_silent_save;
8155 }
8156 
8157 /*
8158  * ":echo expr1 ..."	print each argument separated with a space, add a
8159  *			newline at the end.
8160  * ":echon expr1 ..."	print each argument plain.
8161  */
8162     void
8163 ex_echo(exarg_T *eap)
8164 {
8165     char_u	*arg = eap->arg;
8166     typval_T	rettv;
8167     char_u	*tofree;
8168     char_u	*p;
8169     int		needclr = TRUE;
8170     int		atstart = TRUE;
8171     char_u	numbuf[NUMBUFLEN];
8172 
8173     if (eap->skip)
8174 	++emsg_skip;
8175     while (*arg != NUL && *arg != '|' && *arg != '\n' && !got_int)
8176     {
8177 	/* If eval1() causes an error message the text from the command may
8178 	 * still need to be cleared. E.g., "echo 22,44". */
8179 	need_clr_eos = needclr;
8180 
8181 	p = arg;
8182 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8183 	{
8184 	    /*
8185 	     * Report the invalid expression unless the expression evaluation
8186 	     * has been cancelled due to an aborting error, an interrupt, or an
8187 	     * exception.
8188 	     */
8189 	    if (!aborting())
8190 		EMSG2(_(e_invexpr2), p);
8191 	    need_clr_eos = FALSE;
8192 	    break;
8193 	}
8194 	need_clr_eos = FALSE;
8195 
8196 	if (!eap->skip)
8197 	{
8198 	    if (atstart)
8199 	    {
8200 		atstart = FALSE;
8201 		/* Call msg_start() after eval1(), evaluating the expression
8202 		 * may cause a message to appear. */
8203 		if (eap->cmdidx == CMD_echo)
8204 		{
8205 		    /* Mark the saved text as finishing the line, so that what
8206 		     * follows is displayed on a new line when scrolling back
8207 		     * at the more prompt. */
8208 		    msg_sb_eol();
8209 		    msg_start();
8210 		}
8211 	    }
8212 	    else if (eap->cmdidx == CMD_echo)
8213 		msg_puts_attr((char_u *)" ", echo_attr);
8214 	    p = echo_string(&rettv, &tofree, numbuf, get_copyID());
8215 	    if (p != NULL)
8216 		for ( ; *p != NUL && !got_int; ++p)
8217 		{
8218 		    if (*p == '\n' || *p == '\r' || *p == TAB)
8219 		    {
8220 			if (*p != TAB && needclr)
8221 			{
8222 			    /* remove any text still there from the command */
8223 			    msg_clr_eos();
8224 			    needclr = FALSE;
8225 			}
8226 			msg_putchar_attr(*p, echo_attr);
8227 		    }
8228 		    else
8229 		    {
8230 #ifdef FEAT_MBYTE
8231 			if (has_mbyte)
8232 			{
8233 			    int i = (*mb_ptr2len)(p);
8234 
8235 			    (void)msg_outtrans_len_attr(p, i, echo_attr);
8236 			    p += i - 1;
8237 			}
8238 			else
8239 #endif
8240 			    (void)msg_outtrans_len_attr(p, 1, echo_attr);
8241 		    }
8242 		}
8243 	    vim_free(tofree);
8244 	}
8245 	clear_tv(&rettv);
8246 	arg = skipwhite(arg);
8247     }
8248     eap->nextcmd = check_nextcmd(arg);
8249 
8250     if (eap->skip)
8251 	--emsg_skip;
8252     else
8253     {
8254 	/* remove text that may still be there from the command */
8255 	if (needclr)
8256 	    msg_clr_eos();
8257 	if (eap->cmdidx == CMD_echo)
8258 	    msg_end();
8259     }
8260 }
8261 
8262 /*
8263  * ":echohl {name}".
8264  */
8265     void
8266 ex_echohl(exarg_T *eap)
8267 {
8268     int		id;
8269 
8270     id = syn_name2id(eap->arg);
8271     if (id == 0)
8272 	echo_attr = 0;
8273     else
8274 	echo_attr = syn_id2attr(id);
8275 }
8276 
8277 /*
8278  * ":execute expr1 ..."	execute the result of an expression.
8279  * ":echomsg expr1 ..."	Print a message
8280  * ":echoerr expr1 ..."	Print an error
8281  * Each gets spaces around each argument and a newline at the end for
8282  * echo commands
8283  */
8284     void
8285 ex_execute(exarg_T *eap)
8286 {
8287     char_u	*arg = eap->arg;
8288     typval_T	rettv;
8289     int		ret = OK;
8290     char_u	*p;
8291     garray_T	ga;
8292     int		len;
8293     int		save_did_emsg;
8294 
8295     ga_init2(&ga, 1, 80);
8296 
8297     if (eap->skip)
8298 	++emsg_skip;
8299     while (*arg != NUL && *arg != '|' && *arg != '\n')
8300     {
8301 	p = arg;
8302 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8303 	{
8304 	    /*
8305 	     * Report the invalid expression unless the expression evaluation
8306 	     * has been cancelled due to an aborting error, an interrupt, or an
8307 	     * exception.
8308 	     */
8309 	    if (!aborting())
8310 		EMSG2(_(e_invexpr2), p);
8311 	    ret = FAIL;
8312 	    break;
8313 	}
8314 
8315 	if (!eap->skip)
8316 	{
8317 	    p = get_tv_string(&rettv);
8318 	    len = (int)STRLEN(p);
8319 	    if (ga_grow(&ga, len + 2) == FAIL)
8320 	    {
8321 		clear_tv(&rettv);
8322 		ret = FAIL;
8323 		break;
8324 	    }
8325 	    if (ga.ga_len)
8326 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
8327 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
8328 	    ga.ga_len += len;
8329 	}
8330 
8331 	clear_tv(&rettv);
8332 	arg = skipwhite(arg);
8333     }
8334 
8335     if (ret != FAIL && ga.ga_data != NULL)
8336     {
8337 	if (eap->cmdidx == CMD_echomsg)
8338 	{
8339 	    MSG_ATTR(ga.ga_data, echo_attr);
8340 	    out_flush();
8341 	}
8342 	else if (eap->cmdidx == CMD_echoerr)
8343 	{
8344 	    /* We don't want to abort following commands, restore did_emsg. */
8345 	    save_did_emsg = did_emsg;
8346 	    EMSG((char_u *)ga.ga_data);
8347 	    if (!force_abort)
8348 		did_emsg = save_did_emsg;
8349 	}
8350 	else if (eap->cmdidx == CMD_execute)
8351 	    do_cmdline((char_u *)ga.ga_data,
8352 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
8353     }
8354 
8355     ga_clear(&ga);
8356 
8357     if (eap->skip)
8358 	--emsg_skip;
8359 
8360     eap->nextcmd = check_nextcmd(arg);
8361 }
8362 
8363 /*
8364  * Find window specified by "vp" in tabpage "tp".
8365  */
8366     win_T *
8367 find_win_by_nr(
8368     typval_T	*vp,
8369     tabpage_T	*tp UNUSED)	/* NULL for current tab page */
8370 {
8371 #ifdef FEAT_WINDOWS
8372     win_T	*wp;
8373 #endif
8374     int		nr;
8375 
8376     nr = (int)get_tv_number_chk(vp, NULL);
8377 
8378 #ifdef FEAT_WINDOWS
8379     if (nr < 0)
8380 	return NULL;
8381     if (nr == 0)
8382 	return curwin;
8383 
8384     FOR_ALL_WINDOWS_IN_TAB(tp, wp)
8385     {
8386 	if (nr >= LOWEST_WIN_ID)
8387 	{
8388 	    if (wp->w_id == nr)
8389 		return wp;
8390 	}
8391 	else if (--nr <= 0)
8392 	    break;
8393     }
8394     if (nr >= LOWEST_WIN_ID)
8395 	return NULL;
8396     return wp;
8397 #else
8398     if (nr == 0 || nr == 1 || nr == curwin->w_id)
8399 	return curwin;
8400     return NULL;
8401 #endif
8402 }
8403 
8404 /*
8405  * Find window specified by "wvp" in tabpage "tvp".
8406  */
8407     win_T *
8408 find_tabwin(
8409     typval_T	*wvp,	/* VAR_UNKNOWN for current window */
8410     typval_T	*tvp)	/* VAR_UNKNOWN for current tab page */
8411 {
8412     win_T	*wp = NULL;
8413     tabpage_T	*tp = NULL;
8414     long	n;
8415 
8416     if (wvp->v_type != VAR_UNKNOWN)
8417     {
8418 	if (tvp->v_type != VAR_UNKNOWN)
8419 	{
8420 	    n = (long)get_tv_number(tvp);
8421 	    if (n >= 0)
8422 		tp = find_tabpage(n);
8423 	}
8424 	else
8425 	    tp = curtab;
8426 
8427 	if (tp != NULL)
8428 	    wp = find_win_by_nr(wvp, tp);
8429     }
8430     else
8431 	wp = curwin;
8432 
8433     return wp;
8434 }
8435 
8436 /*
8437  * getwinvar() and gettabwinvar()
8438  */
8439     void
8440 getwinvar(
8441     typval_T	*argvars,
8442     typval_T	*rettv,
8443     int		off)	    /* 1 for gettabwinvar() */
8444 {
8445     win_T	*win;
8446     char_u	*varname;
8447     dictitem_T	*v;
8448     tabpage_T	*tp = NULL;
8449     int		done = FALSE;
8450 #ifdef FEAT_WINDOWS
8451     win_T	*oldcurwin;
8452     tabpage_T	*oldtabpage;
8453     int		need_switch_win;
8454 #endif
8455 
8456 #ifdef FEAT_WINDOWS
8457     if (off == 1)
8458 	tp = find_tabpage((int)get_tv_number_chk(&argvars[0], NULL));
8459     else
8460 	tp = curtab;
8461 #endif
8462     win = find_win_by_nr(&argvars[off], tp);
8463     varname = get_tv_string_chk(&argvars[off + 1]);
8464     ++emsg_off;
8465 
8466     rettv->v_type = VAR_STRING;
8467     rettv->vval.v_string = NULL;
8468 
8469     if (win != NULL && varname != NULL)
8470     {
8471 #ifdef FEAT_WINDOWS
8472 	/* Set curwin to be our win, temporarily.  Also set the tabpage,
8473 	 * otherwise the window is not valid. Only do this when needed,
8474 	 * autocommands get blocked. */
8475 	need_switch_win = !(tp == curtab && win == curwin);
8476 	if (!need_switch_win
8477 		  || switch_win(&oldcurwin, &oldtabpage, win, tp, TRUE) == OK)
8478 #endif
8479 	{
8480 	    if (*varname == '&')
8481 	    {
8482 		if (varname[1] == NUL)
8483 		{
8484 		    /* get all window-local options in a dict */
8485 		    dict_T	*opts = get_winbuf_options(FALSE);
8486 
8487 		    if (opts != NULL)
8488 		    {
8489 			rettv->v_type = VAR_DICT;
8490 			rettv->vval.v_dict = opts;
8491 			++opts->dv_refcount;
8492 			done = TRUE;
8493 		    }
8494 		}
8495 		else if (get_option_tv(&varname, rettv, 1) == OK)
8496 		    /* window-local-option */
8497 		    done = TRUE;
8498 	    }
8499 	    else
8500 	    {
8501 		/* Look up the variable. */
8502 		/* Let getwinvar({nr}, "") return the "w:" dictionary. */
8503 		v = find_var_in_ht(&win->w_vars->dv_hashtab, 'w',
8504 							      varname, FALSE);
8505 		if (v != NULL)
8506 		{
8507 		    copy_tv(&v->di_tv, rettv);
8508 		    done = TRUE;
8509 		}
8510 	    }
8511 	}
8512 
8513 #ifdef FEAT_WINDOWS
8514 	if (need_switch_win)
8515 	    /* restore previous notion of curwin */
8516 	    restore_win(oldcurwin, oldtabpage, TRUE);
8517 #endif
8518     }
8519 
8520     if (!done && argvars[off + 2].v_type != VAR_UNKNOWN)
8521 	/* use the default return value */
8522 	copy_tv(&argvars[off + 2], rettv);
8523 
8524     --emsg_off;
8525 }
8526 
8527 /*
8528  * "setwinvar()" and "settabwinvar()" functions
8529  */
8530     void
8531 setwinvar(typval_T *argvars, typval_T *rettv UNUSED, int off)
8532 {
8533     win_T	*win;
8534 #ifdef FEAT_WINDOWS
8535     win_T	*save_curwin;
8536     tabpage_T	*save_curtab;
8537     int		need_switch_win;
8538 #endif
8539     char_u	*varname, *winvarname;
8540     typval_T	*varp;
8541     char_u	nbuf[NUMBUFLEN];
8542     tabpage_T	*tp = NULL;
8543 
8544     if (check_restricted() || check_secure())
8545 	return;
8546 
8547 #ifdef FEAT_WINDOWS
8548     if (off == 1)
8549 	tp = find_tabpage((int)get_tv_number_chk(&argvars[0], NULL));
8550     else
8551 	tp = curtab;
8552 #endif
8553     win = find_win_by_nr(&argvars[off], tp);
8554     varname = get_tv_string_chk(&argvars[off + 1]);
8555     varp = &argvars[off + 2];
8556 
8557     if (win != NULL && varname != NULL && varp != NULL)
8558     {
8559 #ifdef FEAT_WINDOWS
8560 	need_switch_win = !(tp == curtab && win == curwin);
8561 	if (!need_switch_win
8562 	       || switch_win(&save_curwin, &save_curtab, win, tp, TRUE) == OK)
8563 #endif
8564 	{
8565 	    if (*varname == '&')
8566 	    {
8567 		long	numval;
8568 		char_u	*strval;
8569 		int		error = FALSE;
8570 
8571 		++varname;
8572 		numval = (long)get_tv_number_chk(varp, &error);
8573 		strval = get_tv_string_buf_chk(varp, nbuf);
8574 		if (!error && strval != NULL)
8575 		    set_option_value(varname, numval, strval, OPT_LOCAL);
8576 	    }
8577 	    else
8578 	    {
8579 		winvarname = alloc((unsigned)STRLEN(varname) + 3);
8580 		if (winvarname != NULL)
8581 		{
8582 		    STRCPY(winvarname, "w:");
8583 		    STRCPY(winvarname + 2, varname);
8584 		    set_var(winvarname, varp, TRUE);
8585 		    vim_free(winvarname);
8586 		}
8587 	    }
8588 	}
8589 #ifdef FEAT_WINDOWS
8590 	if (need_switch_win)
8591 	    restore_win(save_curwin, save_curtab, TRUE);
8592 #endif
8593     }
8594 }
8595 
8596 /*
8597  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
8598  * "arg" points to the "&" or '+' when called, to "option" when returning.
8599  * Returns NULL when no option name found.  Otherwise pointer to the char
8600  * after the option name.
8601  */
8602     static char_u *
8603 find_option_end(char_u **arg, int *opt_flags)
8604 {
8605     char_u	*p = *arg;
8606 
8607     ++p;
8608     if (*p == 'g' && p[1] == ':')
8609     {
8610 	*opt_flags = OPT_GLOBAL;
8611 	p += 2;
8612     }
8613     else if (*p == 'l' && p[1] == ':')
8614     {
8615 	*opt_flags = OPT_LOCAL;
8616 	p += 2;
8617     }
8618     else
8619 	*opt_flags = 0;
8620 
8621     if (!ASCII_ISALPHA(*p))
8622 	return NULL;
8623     *arg = p;
8624 
8625     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
8626 	p += 4;	    /* termcap option */
8627     else
8628 	while (ASCII_ISALPHA(*p))
8629 	    ++p;
8630     return p;
8631 }
8632 
8633 /*
8634  * Return the autoload script name for a function or variable name.
8635  * Returns NULL when out of memory.
8636  */
8637     char_u *
8638 autoload_name(char_u *name)
8639 {
8640     char_u	*p;
8641     char_u	*scriptname;
8642 
8643     /* Get the script file name: replace '#' with '/', append ".vim". */
8644     scriptname = alloc((unsigned)(STRLEN(name) + 14));
8645     if (scriptname == NULL)
8646 	return FALSE;
8647     STRCPY(scriptname, "autoload/");
8648     STRCAT(scriptname, name);
8649     *vim_strrchr(scriptname, AUTOLOAD_CHAR) = NUL;
8650     STRCAT(scriptname, ".vim");
8651     while ((p = vim_strchr(scriptname, AUTOLOAD_CHAR)) != NULL)
8652 	*p = '/';
8653     return scriptname;
8654 }
8655 
8656 /*
8657  * If "name" has a package name try autoloading the script for it.
8658  * Return TRUE if a package was loaded.
8659  */
8660     int
8661 script_autoload(
8662     char_u	*name,
8663     int		reload)	    /* load script again when already loaded */
8664 {
8665     char_u	*p;
8666     char_u	*scriptname, *tofree;
8667     int		ret = FALSE;
8668     int		i;
8669 
8670     /* If there is no '#' after name[0] there is no package name. */
8671     p = vim_strchr(name, AUTOLOAD_CHAR);
8672     if (p == NULL || p == name)
8673 	return FALSE;
8674 
8675     tofree = scriptname = autoload_name(name);
8676 
8677     /* Find the name in the list of previously loaded package names.  Skip
8678      * "autoload/", it's always the same. */
8679     for (i = 0; i < ga_loaded.ga_len; ++i)
8680 	if (STRCMP(((char_u **)ga_loaded.ga_data)[i] + 9, scriptname + 9) == 0)
8681 	    break;
8682     if (!reload && i < ga_loaded.ga_len)
8683 	ret = FALSE;	    /* was loaded already */
8684     else
8685     {
8686 	/* Remember the name if it wasn't loaded already. */
8687 	if (i == ga_loaded.ga_len && ga_grow(&ga_loaded, 1) == OK)
8688 	{
8689 	    ((char_u **)ga_loaded.ga_data)[ga_loaded.ga_len++] = scriptname;
8690 	    tofree = NULL;
8691 	}
8692 
8693 	/* Try loading the package from $VIMRUNTIME/autoload/<name>.vim */
8694 	if (source_runtime(scriptname, 0) == OK)
8695 	    ret = TRUE;
8696     }
8697 
8698     vim_free(tofree);
8699     return ret;
8700 }
8701 
8702 #if defined(FEAT_VIMINFO) || defined(FEAT_SESSION)
8703 typedef enum
8704 {
8705     VAR_FLAVOUR_DEFAULT,	/* doesn't start with uppercase */
8706     VAR_FLAVOUR_SESSION,	/* starts with uppercase, some lower */
8707     VAR_FLAVOUR_VIMINFO		/* all uppercase */
8708 } var_flavour_T;
8709 
8710 static var_flavour_T var_flavour(char_u *varname);
8711 
8712     static var_flavour_T
8713 var_flavour(char_u *varname)
8714 {
8715     char_u *p = varname;
8716 
8717     if (ASCII_ISUPPER(*p))
8718     {
8719 	while (*(++p))
8720 	    if (ASCII_ISLOWER(*p))
8721 		return VAR_FLAVOUR_SESSION;
8722 	return VAR_FLAVOUR_VIMINFO;
8723     }
8724     else
8725 	return VAR_FLAVOUR_DEFAULT;
8726 }
8727 #endif
8728 
8729 #if defined(FEAT_VIMINFO) || defined(PROTO)
8730 /*
8731  * Restore global vars that start with a capital from the viminfo file
8732  */
8733     int
8734 read_viminfo_varlist(vir_T *virp, int writing)
8735 {
8736     char_u	*tab;
8737     int		type = VAR_NUMBER;
8738     typval_T	tv;
8739     void	*save_funccal;
8740 
8741     if (!writing && (find_viminfo_parameter('!') != NULL))
8742     {
8743 	tab = vim_strchr(virp->vir_line + 1, '\t');
8744 	if (tab != NULL)
8745 	{
8746 	    *tab++ = '\0';	/* isolate the variable name */
8747 	    switch (*tab)
8748 	    {
8749 		case 'S': type = VAR_STRING; break;
8750 #ifdef FEAT_FLOAT
8751 		case 'F': type = VAR_FLOAT; break;
8752 #endif
8753 		case 'D': type = VAR_DICT; break;
8754 		case 'L': type = VAR_LIST; break;
8755 		case 'X': type = VAR_SPECIAL; break;
8756 	    }
8757 
8758 	    tab = vim_strchr(tab, '\t');
8759 	    if (tab != NULL)
8760 	    {
8761 		tv.v_type = type;
8762 		if (type == VAR_STRING || type == VAR_DICT || type == VAR_LIST)
8763 		    tv.vval.v_string = viminfo_readstring(virp,
8764 				       (int)(tab - virp->vir_line + 1), TRUE);
8765 #ifdef FEAT_FLOAT
8766 		else if (type == VAR_FLOAT)
8767 		    (void)string2float(tab + 1, &tv.vval.v_float);
8768 #endif
8769 		else
8770 		    tv.vval.v_number = atol((char *)tab + 1);
8771 		if (type == VAR_DICT || type == VAR_LIST)
8772 		{
8773 		    typval_T *etv = eval_expr(tv.vval.v_string, NULL);
8774 
8775 		    if (etv == NULL)
8776 			/* Failed to parse back the dict or list, use it as a
8777 			 * string. */
8778 			tv.v_type = VAR_STRING;
8779 		    else
8780 		    {
8781 			vim_free(tv.vval.v_string);
8782 			tv = *etv;
8783 			vim_free(etv);
8784 		    }
8785 		}
8786 
8787 		/* when in a function use global variables */
8788 		save_funccal = clear_current_funccal();
8789 		set_var(virp->vir_line + 1, &tv, FALSE);
8790 		restore_current_funccal(save_funccal);
8791 
8792 		if (tv.v_type == VAR_STRING)
8793 		    vim_free(tv.vval.v_string);
8794 		else if (tv.v_type == VAR_DICT || tv.v_type == VAR_LIST)
8795 		    clear_tv(&tv);
8796 	    }
8797 	}
8798     }
8799 
8800     return viminfo_readline(virp);
8801 }
8802 
8803 /*
8804  * Write global vars that start with a capital to the viminfo file
8805  */
8806     void
8807 write_viminfo_varlist(FILE *fp)
8808 {
8809     hashitem_T	*hi;
8810     dictitem_T	*this_var;
8811     int		todo;
8812     char	*s = "";
8813     char_u	*p;
8814     char_u	*tofree;
8815     char_u	numbuf[NUMBUFLEN];
8816 
8817     if (find_viminfo_parameter('!') == NULL)
8818 	return;
8819 
8820     fputs(_("\n# global variables:\n"), fp);
8821 
8822     todo = (int)globvarht.ht_used;
8823     for (hi = globvarht.ht_array; todo > 0; ++hi)
8824     {
8825 	if (!HASHITEM_EMPTY(hi))
8826 	{
8827 	    --todo;
8828 	    this_var = HI2DI(hi);
8829 	    if (var_flavour(this_var->di_key) == VAR_FLAVOUR_VIMINFO)
8830 	    {
8831 		switch (this_var->di_tv.v_type)
8832 		{
8833 		    case VAR_STRING: s = "STR"; break;
8834 		    case VAR_NUMBER: s = "NUM"; break;
8835 		    case VAR_FLOAT:  s = "FLO"; break;
8836 		    case VAR_DICT:   s = "DIC"; break;
8837 		    case VAR_LIST:   s = "LIS"; break;
8838 		    case VAR_SPECIAL: s = "XPL"; break;
8839 
8840 		    case VAR_UNKNOWN:
8841 		    case VAR_FUNC:
8842 		    case VAR_PARTIAL:
8843 		    case VAR_JOB:
8844 		    case VAR_CHANNEL:
8845 				     continue;
8846 		}
8847 		fprintf(fp, "!%s\t%s\t", this_var->di_key, s);
8848 		p = echo_string(&this_var->di_tv, &tofree, numbuf, 0);
8849 		if (p != NULL)
8850 		    viminfo_writestring(fp, p);
8851 		vim_free(tofree);
8852 	    }
8853 	}
8854     }
8855 }
8856 #endif
8857 
8858 #if defined(FEAT_SESSION) || defined(PROTO)
8859     int
8860 store_session_globals(FILE *fd)
8861 {
8862     hashitem_T	*hi;
8863     dictitem_T	*this_var;
8864     int		todo;
8865     char_u	*p, *t;
8866 
8867     todo = (int)globvarht.ht_used;
8868     for (hi = globvarht.ht_array; todo > 0; ++hi)
8869     {
8870 	if (!HASHITEM_EMPTY(hi))
8871 	{
8872 	    --todo;
8873 	    this_var = HI2DI(hi);
8874 	    if ((this_var->di_tv.v_type == VAR_NUMBER
8875 			|| this_var->di_tv.v_type == VAR_STRING)
8876 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
8877 	    {
8878 		/* Escape special characters with a backslash.  Turn a LF and
8879 		 * CR into \n and \r. */
8880 		p = vim_strsave_escaped(get_tv_string(&this_var->di_tv),
8881 							(char_u *)"\\\"\n\r");
8882 		if (p == NULL)	    /* out of memory */
8883 		    break;
8884 		for (t = p; *t != NUL; ++t)
8885 		    if (*t == '\n')
8886 			*t = 'n';
8887 		    else if (*t == '\r')
8888 			*t = 'r';
8889 		if ((fprintf(fd, "let %s = %c%s%c",
8890 				this_var->di_key,
8891 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
8892 									: ' ',
8893 				p,
8894 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
8895 								   : ' ') < 0)
8896 			|| put_eol(fd) == FAIL)
8897 		{
8898 		    vim_free(p);
8899 		    return FAIL;
8900 		}
8901 		vim_free(p);
8902 	    }
8903 #ifdef FEAT_FLOAT
8904 	    else if (this_var->di_tv.v_type == VAR_FLOAT
8905 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
8906 	    {
8907 		float_T f = this_var->di_tv.vval.v_float;
8908 		int sign = ' ';
8909 
8910 		if (f < 0)
8911 		{
8912 		    f = -f;
8913 		    sign = '-';
8914 		}
8915 		if ((fprintf(fd, "let %s = %c%f",
8916 					       this_var->di_key, sign, f) < 0)
8917 			|| put_eol(fd) == FAIL)
8918 		    return FAIL;
8919 	    }
8920 #endif
8921 	}
8922     }
8923     return OK;
8924 }
8925 #endif
8926 
8927 /*
8928  * Display script name where an item was last set.
8929  * Should only be invoked when 'verbose' is non-zero.
8930  */
8931     void
8932 last_set_msg(scid_T scriptID)
8933 {
8934     char_u *p;
8935 
8936     if (scriptID != 0)
8937     {
8938 	p = home_replace_save(NULL, get_scriptname(scriptID));
8939 	if (p != NULL)
8940 	{
8941 	    verbose_enter();
8942 	    MSG_PUTS(_("\n\tLast set from "));
8943 	    MSG_PUTS(p);
8944 	    vim_free(p);
8945 	    verbose_leave();
8946 	}
8947     }
8948 }
8949 
8950 /* reset v:option_new, v:option_old and v:option_type */
8951     void
8952 reset_v_option_vars(void)
8953 {
8954     set_vim_var_string(VV_OPTION_NEW,  NULL, -1);
8955     set_vim_var_string(VV_OPTION_OLD,  NULL, -1);
8956     set_vim_var_string(VV_OPTION_TYPE, NULL, -1);
8957 }
8958 
8959 /*
8960  * Prepare "gap" for an assert error and add the sourcing position.
8961  */
8962     void
8963 prepare_assert_error(garray_T *gap)
8964 {
8965     char buf[NUMBUFLEN];
8966 
8967     ga_init2(gap, 1, 100);
8968     if (sourcing_name != NULL)
8969     {
8970 	ga_concat(gap, sourcing_name);
8971 	if (sourcing_lnum > 0)
8972 	    ga_concat(gap, (char_u *)" ");
8973     }
8974     if (sourcing_lnum > 0)
8975     {
8976 	sprintf(buf, "line %ld", (long)sourcing_lnum);
8977 	ga_concat(gap, (char_u *)buf);
8978     }
8979     if (sourcing_name != NULL || sourcing_lnum > 0)
8980 	ga_concat(gap, (char_u *)": ");
8981 }
8982 
8983 /*
8984  * Add an assert error to v:errors.
8985  */
8986     void
8987 assert_error(garray_T *gap)
8988 {
8989     struct vimvar   *vp = &vimvars[VV_ERRORS];
8990 
8991     if (vp->vv_type != VAR_LIST || vimvars[VV_ERRORS].vv_list == NULL)
8992 	/* Make sure v:errors is a list. */
8993 	set_vim_var_list(VV_ERRORS, list_alloc());
8994     list_append_string(vimvars[VV_ERRORS].vv_list, gap->ga_data, gap->ga_len);
8995 }
8996 
8997     void
8998 assert_equal_common(typval_T *argvars, assert_type_T atype)
8999 {
9000     garray_T	ga;
9001 
9002     if (tv_equal(&argvars[0], &argvars[1], FALSE, FALSE)
9003 						   != (atype == ASSERT_EQUAL))
9004     {
9005 	prepare_assert_error(&ga);
9006 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
9007 								       atype);
9008 	assert_error(&ga);
9009 	ga_clear(&ga);
9010     }
9011 }
9012 
9013     void
9014 assert_match_common(typval_T *argvars, assert_type_T atype)
9015 {
9016     garray_T	ga;
9017     char_u	buf1[NUMBUFLEN];
9018     char_u	buf2[NUMBUFLEN];
9019     char_u	*pat = get_tv_string_buf_chk(&argvars[0], buf1);
9020     char_u	*text = get_tv_string_buf_chk(&argvars[1], buf2);
9021 
9022     if (pat == NULL || text == NULL)
9023 	EMSG(_(e_invarg));
9024     else if (pattern_match(pat, text, FALSE) != (atype == ASSERT_MATCH))
9025     {
9026 	prepare_assert_error(&ga);
9027 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
9028 									atype);
9029 	assert_error(&ga);
9030 	ga_clear(&ga);
9031     }
9032 }
9033 
9034     void
9035 assert_inrange(typval_T *argvars)
9036 {
9037     garray_T	ga;
9038     int		error = FALSE;
9039     varnumber_T	lower = get_tv_number_chk(&argvars[0], &error);
9040     varnumber_T	upper = get_tv_number_chk(&argvars[1], &error);
9041     varnumber_T	actual = get_tv_number_chk(&argvars[2], &error);
9042     char_u	*tofree;
9043     char	msg[200];
9044     char_u	numbuf[NUMBUFLEN];
9045 
9046     if (error)
9047 	return;
9048     if (actual < lower || actual > upper)
9049     {
9050 	prepare_assert_error(&ga);
9051 	if (argvars[3].v_type != VAR_UNKNOWN)
9052 	{
9053 	    ga_concat(&ga, tv2string(&argvars[3], &tofree, numbuf, 0));
9054 	    vim_free(tofree);
9055 	}
9056 	else
9057 	{
9058 	    vim_snprintf(msg, 200, "Expected range %ld - %ld, but got %ld",
9059 				       (long)lower, (long)upper, (long)actual);
9060 	    ga_concat(&ga, (char_u *)msg);
9061 	}
9062 	assert_error(&ga);
9063 	ga_clear(&ga);
9064     }
9065 }
9066 
9067 /*
9068  * Common for assert_true() and assert_false().
9069  */
9070     void
9071 assert_bool(typval_T *argvars, int isTrue)
9072 {
9073     int		error = FALSE;
9074     garray_T	ga;
9075 
9076     if (argvars[0].v_type == VAR_SPECIAL
9077 	    && argvars[0].vval.v_number == (isTrue ? VVAL_TRUE : VVAL_FALSE))
9078 	return;
9079     if (argvars[0].v_type != VAR_NUMBER
9080 	    || (get_tv_number_chk(&argvars[0], &error) == 0) == isTrue
9081 	    || error)
9082     {
9083 	prepare_assert_error(&ga);
9084 	fill_assert_error(&ga, &argvars[1],
9085 		(char_u *)(isTrue ? "True" : "False"),
9086 		NULL, &argvars[0], ASSERT_OTHER);
9087 	assert_error(&ga);
9088 	ga_clear(&ga);
9089     }
9090 }
9091 
9092     void
9093 assert_exception(typval_T *argvars)
9094 {
9095     garray_T	ga;
9096     char_u	*error = get_tv_string_chk(&argvars[0]);
9097 
9098     if (vimvars[VV_EXCEPTION].vv_str == NULL)
9099     {
9100 	prepare_assert_error(&ga);
9101 	ga_concat(&ga, (char_u *)"v:exception is not set");
9102 	assert_error(&ga);
9103 	ga_clear(&ga);
9104     }
9105     else if (error != NULL
9106 	&& strstr((char *)vimvars[VV_EXCEPTION].vv_str, (char *)error) == NULL)
9107     {
9108 	prepare_assert_error(&ga);
9109 	fill_assert_error(&ga, &argvars[1], NULL, &argvars[0],
9110 				  &vimvars[VV_EXCEPTION].vv_tv, ASSERT_OTHER);
9111 	assert_error(&ga);
9112 	ga_clear(&ga);
9113     }
9114 }
9115 
9116     void
9117 assert_fails(typval_T *argvars)
9118 {
9119     char_u	*cmd = get_tv_string_chk(&argvars[0]);
9120     garray_T	ga;
9121 
9122     called_emsg = FALSE;
9123     suppress_errthrow = TRUE;
9124     emsg_silent = TRUE;
9125     do_cmdline_cmd(cmd);
9126     if (!called_emsg)
9127     {
9128 	prepare_assert_error(&ga);
9129 	ga_concat(&ga, (char_u *)"command did not fail: ");
9130 	ga_concat(&ga, cmd);
9131 	assert_error(&ga);
9132 	ga_clear(&ga);
9133     }
9134     else if (argvars[1].v_type != VAR_UNKNOWN)
9135     {
9136 	char_u	buf[NUMBUFLEN];
9137 	char	*error = (char *)get_tv_string_buf_chk(&argvars[1], buf);
9138 
9139 	if (error == NULL
9140 		  || strstr((char *)vimvars[VV_ERRMSG].vv_str, error) == NULL)
9141 	{
9142 	    prepare_assert_error(&ga);
9143 	    fill_assert_error(&ga, &argvars[2], NULL, &argvars[1],
9144 				     &vimvars[VV_ERRMSG].vv_tv, ASSERT_OTHER);
9145 	    assert_error(&ga);
9146 	    ga_clear(&ga);
9147 	}
9148     }
9149 
9150     called_emsg = FALSE;
9151     suppress_errthrow = FALSE;
9152     emsg_silent = FALSE;
9153     emsg_on_display = FALSE;
9154     set_vim_var_string(VV_ERRMSG, NULL, 0);
9155 }
9156 
9157 /*
9158  * Append "str" to "gap", escaping unprintable characters.
9159  * Changes NL to \n, CR to \r, etc.
9160  */
9161     static void
9162 ga_concat_esc(garray_T *gap, char_u *str)
9163 {
9164     char_u  *p;
9165     char_u  buf[NUMBUFLEN];
9166 
9167     if (str == NULL)
9168     {
9169 	ga_concat(gap, (char_u *)"NULL");
9170 	return;
9171     }
9172 
9173     for (p = str; *p != NUL; ++p)
9174 	switch (*p)
9175 	{
9176 	    case BS: ga_concat(gap, (char_u *)"\\b"); break;
9177 	    case ESC: ga_concat(gap, (char_u *)"\\e"); break;
9178 	    case FF: ga_concat(gap, (char_u *)"\\f"); break;
9179 	    case NL: ga_concat(gap, (char_u *)"\\n"); break;
9180 	    case TAB: ga_concat(gap, (char_u *)"\\t"); break;
9181 	    case CAR: ga_concat(gap, (char_u *)"\\r"); break;
9182 	    case '\\': ga_concat(gap, (char_u *)"\\\\"); break;
9183 	    default:
9184 		if (*p < ' ')
9185 		{
9186 		    vim_snprintf((char *)buf, NUMBUFLEN, "\\x%02x", *p);
9187 		    ga_concat(gap, buf);
9188 		}
9189 		else
9190 		    ga_append(gap, *p);
9191 		break;
9192 	}
9193 }
9194 
9195 /*
9196  * Fill "gap" with information about an assert error.
9197  */
9198     void
9199 fill_assert_error(
9200     garray_T	*gap,
9201     typval_T	*opt_msg_tv,
9202     char_u      *exp_str,
9203     typval_T	*exp_tv,
9204     typval_T	*got_tv,
9205     assert_type_T atype)
9206 {
9207     char_u	numbuf[NUMBUFLEN];
9208     char_u	*tofree;
9209 
9210     if (opt_msg_tv->v_type != VAR_UNKNOWN)
9211     {
9212 	ga_concat(gap, tv2string(opt_msg_tv, &tofree, numbuf, 0));
9213 	vim_free(tofree);
9214     }
9215     else
9216     {
9217 	if (atype == ASSERT_MATCH || atype == ASSERT_NOTMATCH)
9218 	    ga_concat(gap, (char_u *)"Pattern ");
9219 	else
9220 	    ga_concat(gap, (char_u *)"Expected ");
9221 	if (exp_str == NULL)
9222 	{
9223 	    ga_concat_esc(gap, tv2string(exp_tv, &tofree, numbuf, 0));
9224 	    vim_free(tofree);
9225 	}
9226 	else
9227 	    ga_concat_esc(gap, exp_str);
9228 	if (atype == ASSERT_MATCH)
9229 	    ga_concat(gap, (char_u *)" does not match ");
9230 	else if (atype == ASSERT_NOTMATCH)
9231 	    ga_concat(gap, (char_u *)" does match ");
9232 	else if (atype == ASSERT_NOTEQUAL)
9233 	    ga_concat(gap, (char_u *)" differs from ");
9234 	else
9235 	    ga_concat(gap, (char_u *)" but got ");
9236 	ga_concat_esc(gap, tv2string(got_tv, &tofree, numbuf, 0));
9237 	vim_free(tofree);
9238     }
9239 }
9240 
9241 
9242 #endif /* FEAT_EVAL */
9243 
9244 
9245 #if defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) || defined(PROTO)
9246 
9247 #ifdef WIN3264
9248 /*
9249  * Functions for ":8" filename modifier: get 8.3 version of a filename.
9250  */
9251 static int get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen);
9252 static int shortpath_for_invalid_fname(char_u **fname, char_u **bufp, int *fnamelen);
9253 static int shortpath_for_partial(char_u **fnamep, char_u **bufp, int *fnamelen);
9254 
9255 /*
9256  * Get the short path (8.3) for the filename in "fnamep".
9257  * Only works for a valid file name.
9258  * When the path gets longer "fnamep" is changed and the allocated buffer
9259  * is put in "bufp".
9260  * *fnamelen is the length of "fnamep" and set to 0 for a nonexistent path.
9261  * Returns OK on success, FAIL on failure.
9262  */
9263     static int
9264 get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen)
9265 {
9266     int		l, len;
9267     char_u	*newbuf;
9268 
9269     len = *fnamelen;
9270     l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, len);
9271     if (l > len - 1)
9272     {
9273 	/* If that doesn't work (not enough space), then save the string
9274 	 * and try again with a new buffer big enough. */
9275 	newbuf = vim_strnsave(*fnamep, l);
9276 	if (newbuf == NULL)
9277 	    return FAIL;
9278 
9279 	vim_free(*bufp);
9280 	*fnamep = *bufp = newbuf;
9281 
9282 	/* Really should always succeed, as the buffer is big enough. */
9283 	l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, l+1);
9284     }
9285 
9286     *fnamelen = l;
9287     return OK;
9288 }
9289 
9290 /*
9291  * Get the short path (8.3) for the filename in "fname". The converted
9292  * path is returned in "bufp".
9293  *
9294  * Some of the directories specified in "fname" may not exist. This function
9295  * will shorten the existing directories at the beginning of the path and then
9296  * append the remaining non-existing path.
9297  *
9298  * fname - Pointer to the filename to shorten.  On return, contains the
9299  *	   pointer to the shortened pathname
9300  * bufp -  Pointer to an allocated buffer for the filename.
9301  * fnamelen - Length of the filename pointed to by fname
9302  *
9303  * Returns OK on success (or nothing done) and FAIL on failure (out of memory).
9304  */
9305     static int
9306 shortpath_for_invalid_fname(
9307     char_u	**fname,
9308     char_u	**bufp,
9309     int		*fnamelen)
9310 {
9311     char_u	*short_fname, *save_fname, *pbuf_unused;
9312     char_u	*endp, *save_endp;
9313     char_u	ch;
9314     int		old_len, len;
9315     int		new_len, sfx_len;
9316     int		retval = OK;
9317 
9318     /* Make a copy */
9319     old_len = *fnamelen;
9320     save_fname = vim_strnsave(*fname, old_len);
9321     pbuf_unused = NULL;
9322     short_fname = NULL;
9323 
9324     endp = save_fname + old_len - 1; /* Find the end of the copy */
9325     save_endp = endp;
9326 
9327     /*
9328      * Try shortening the supplied path till it succeeds by removing one
9329      * directory at a time from the tail of the path.
9330      */
9331     len = 0;
9332     for (;;)
9333     {
9334 	/* go back one path-separator */
9335 	while (endp > save_fname && !after_pathsep(save_fname, endp + 1))
9336 	    --endp;
9337 	if (endp <= save_fname)
9338 	    break;		/* processed the complete path */
9339 
9340 	/*
9341 	 * Replace the path separator with a NUL and try to shorten the
9342 	 * resulting path.
9343 	 */
9344 	ch = *endp;
9345 	*endp = 0;
9346 	short_fname = save_fname;
9347 	len = (int)STRLEN(short_fname) + 1;
9348 	if (get_short_pathname(&short_fname, &pbuf_unused, &len) == FAIL)
9349 	{
9350 	    retval = FAIL;
9351 	    goto theend;
9352 	}
9353 	*endp = ch;	/* preserve the string */
9354 
9355 	if (len > 0)
9356 	    break;	/* successfully shortened the path */
9357 
9358 	/* failed to shorten the path. Skip the path separator */
9359 	--endp;
9360     }
9361 
9362     if (len > 0)
9363     {
9364 	/*
9365 	 * Succeeded in shortening the path. Now concatenate the shortened
9366 	 * path with the remaining path at the tail.
9367 	 */
9368 
9369 	/* Compute the length of the new path. */
9370 	sfx_len = (int)(save_endp - endp) + 1;
9371 	new_len = len + sfx_len;
9372 
9373 	*fnamelen = new_len;
9374 	vim_free(*bufp);
9375 	if (new_len > old_len)
9376 	{
9377 	    /* There is not enough space in the currently allocated string,
9378 	     * copy it to a buffer big enough. */
9379 	    *fname = *bufp = vim_strnsave(short_fname, new_len);
9380 	    if (*fname == NULL)
9381 	    {
9382 		retval = FAIL;
9383 		goto theend;
9384 	    }
9385 	}
9386 	else
9387 	{
9388 	    /* Transfer short_fname to the main buffer (it's big enough),
9389 	     * unless get_short_pathname() did its work in-place. */
9390 	    *fname = *bufp = save_fname;
9391 	    if (short_fname != save_fname)
9392 		vim_strncpy(save_fname, short_fname, len);
9393 	    save_fname = NULL;
9394 	}
9395 
9396 	/* concat the not-shortened part of the path */
9397 	vim_strncpy(*fname + len, endp, sfx_len);
9398 	(*fname)[new_len] = NUL;
9399     }
9400 
9401 theend:
9402     vim_free(pbuf_unused);
9403     vim_free(save_fname);
9404 
9405     return retval;
9406 }
9407 
9408 /*
9409  * Get a pathname for a partial path.
9410  * Returns OK for success, FAIL for failure.
9411  */
9412     static int
9413 shortpath_for_partial(
9414     char_u	**fnamep,
9415     char_u	**bufp,
9416     int		*fnamelen)
9417 {
9418     int		sepcount, len, tflen;
9419     char_u	*p;
9420     char_u	*pbuf, *tfname;
9421     int		hasTilde;
9422 
9423     /* Count up the path separators from the RHS.. so we know which part
9424      * of the path to return. */
9425     sepcount = 0;
9426     for (p = *fnamep; p < *fnamep + *fnamelen; mb_ptr_adv(p))
9427 	if (vim_ispathsep(*p))
9428 	    ++sepcount;
9429 
9430     /* Need full path first (use expand_env() to remove a "~/") */
9431     hasTilde = (**fnamep == '~');
9432     if (hasTilde)
9433 	pbuf = tfname = expand_env_save(*fnamep);
9434     else
9435 	pbuf = tfname = FullName_save(*fnamep, FALSE);
9436 
9437     len = tflen = (int)STRLEN(tfname);
9438 
9439     if (get_short_pathname(&tfname, &pbuf, &len) == FAIL)
9440 	return FAIL;
9441 
9442     if (len == 0)
9443     {
9444 	/* Don't have a valid filename, so shorten the rest of the
9445 	 * path if we can. This CAN give us invalid 8.3 filenames, but
9446 	 * there's not a lot of point in guessing what it might be.
9447 	 */
9448 	len = tflen;
9449 	if (shortpath_for_invalid_fname(&tfname, &pbuf, &len) == FAIL)
9450 	    return FAIL;
9451     }
9452 
9453     /* Count the paths backward to find the beginning of the desired string. */
9454     for (p = tfname + len - 1; p >= tfname; --p)
9455     {
9456 #ifdef FEAT_MBYTE
9457 	if (has_mbyte)
9458 	    p -= mb_head_off(tfname, p);
9459 #endif
9460 	if (vim_ispathsep(*p))
9461 	{
9462 	    if (sepcount == 0 || (hasTilde && sepcount == 1))
9463 		break;
9464 	    else
9465 		sepcount --;
9466 	}
9467     }
9468     if (hasTilde)
9469     {
9470 	--p;
9471 	if (p >= tfname)
9472 	    *p = '~';
9473 	else
9474 	    return FAIL;
9475     }
9476     else
9477 	++p;
9478 
9479     /* Copy in the string - p indexes into tfname - allocated at pbuf */
9480     vim_free(*bufp);
9481     *fnamelen = (int)STRLEN(p);
9482     *bufp = pbuf;
9483     *fnamep = p;
9484 
9485     return OK;
9486 }
9487 #endif /* WIN3264 */
9488 
9489 /*
9490  * Adjust a filename, according to a string of modifiers.
9491  * *fnamep must be NUL terminated when called.  When returning, the length is
9492  * determined by *fnamelen.
9493  * Returns VALID_ flags or -1 for failure.
9494  * When there is an error, *fnamep is set to NULL.
9495  */
9496     int
9497 modify_fname(
9498     char_u	*src,		/* string with modifiers */
9499     int		*usedlen,	/* characters after src that are used */
9500     char_u	**fnamep,	/* file name so far */
9501     char_u	**bufp,		/* buffer for allocated file name or NULL */
9502     int		*fnamelen)	/* length of fnamep */
9503 {
9504     int		valid = 0;
9505     char_u	*tail;
9506     char_u	*s, *p, *pbuf;
9507     char_u	dirname[MAXPATHL];
9508     int		c;
9509     int		has_fullname = 0;
9510 #ifdef WIN3264
9511     char_u	*fname_start = *fnamep;
9512     int		has_shortname = 0;
9513 #endif
9514 
9515 repeat:
9516     /* ":p" - full path/file_name */
9517     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'p')
9518     {
9519 	has_fullname = 1;
9520 
9521 	valid |= VALID_PATH;
9522 	*usedlen += 2;
9523 
9524 	/* Expand "~/path" for all systems and "~user/path" for Unix and VMS */
9525 	if ((*fnamep)[0] == '~'
9526 #if !defined(UNIX) && !(defined(VMS) && defined(USER_HOME))
9527 		&& ((*fnamep)[1] == '/'
9528 # ifdef BACKSLASH_IN_FILENAME
9529 		    || (*fnamep)[1] == '\\'
9530 # endif
9531 		    || (*fnamep)[1] == NUL)
9532 
9533 #endif
9534 	   )
9535 	{
9536 	    *fnamep = expand_env_save(*fnamep);
9537 	    vim_free(*bufp);	/* free any allocated file name */
9538 	    *bufp = *fnamep;
9539 	    if (*fnamep == NULL)
9540 		return -1;
9541 	}
9542 
9543 	/* When "/." or "/.." is used: force expansion to get rid of it. */
9544 	for (p = *fnamep; *p != NUL; mb_ptr_adv(p))
9545 	{
9546 	    if (vim_ispathsep(*p)
9547 		    && p[1] == '.'
9548 		    && (p[2] == NUL
9549 			|| vim_ispathsep(p[2])
9550 			|| (p[2] == '.'
9551 			    && (p[3] == NUL || vim_ispathsep(p[3])))))
9552 		break;
9553 	}
9554 
9555 	/* FullName_save() is slow, don't use it when not needed. */
9556 	if (*p != NUL || !vim_isAbsName(*fnamep))
9557 	{
9558 	    *fnamep = FullName_save(*fnamep, *p != NUL);
9559 	    vim_free(*bufp);	/* free any allocated file name */
9560 	    *bufp = *fnamep;
9561 	    if (*fnamep == NULL)
9562 		return -1;
9563 	}
9564 
9565 #ifdef WIN3264
9566 # if _WIN32_WINNT >= 0x0500
9567 	if (vim_strchr(*fnamep, '~') != NULL)
9568 	{
9569 	    /* Expand 8.3 filename to full path.  Needed to make sure the same
9570 	     * file does not have two different names.
9571 	     * Note: problem does not occur if _WIN32_WINNT < 0x0500. */
9572 	    p = alloc(_MAX_PATH + 1);
9573 	    if (p != NULL)
9574 	    {
9575 		if (GetLongPathName((LPSTR)*fnamep, (LPSTR)p, _MAX_PATH))
9576 		{
9577 		    vim_free(*bufp);
9578 		    *bufp = *fnamep = p;
9579 		}
9580 		else
9581 		    vim_free(p);
9582 	    }
9583 	}
9584 # endif
9585 #endif
9586 	/* Append a path separator to a directory. */
9587 	if (mch_isdir(*fnamep))
9588 	{
9589 	    /* Make room for one or two extra characters. */
9590 	    *fnamep = vim_strnsave(*fnamep, (int)STRLEN(*fnamep) + 2);
9591 	    vim_free(*bufp);	/* free any allocated file name */
9592 	    *bufp = *fnamep;
9593 	    if (*fnamep == NULL)
9594 		return -1;
9595 	    add_pathsep(*fnamep);
9596 	}
9597     }
9598 
9599     /* ":." - path relative to the current directory */
9600     /* ":~" - path relative to the home directory */
9601     /* ":8" - shortname path - postponed till after */
9602     while (src[*usedlen] == ':'
9603 		  && ((c = src[*usedlen + 1]) == '.' || c == '~' || c == '8'))
9604     {
9605 	*usedlen += 2;
9606 	if (c == '8')
9607 	{
9608 #ifdef WIN3264
9609 	    has_shortname = 1; /* Postpone this. */
9610 #endif
9611 	    continue;
9612 	}
9613 	pbuf = NULL;
9614 	/* Need full path first (use expand_env() to remove a "~/") */
9615 	if (!has_fullname)
9616 	{
9617 	    if (c == '.' && **fnamep == '~')
9618 		p = pbuf = expand_env_save(*fnamep);
9619 	    else
9620 		p = pbuf = FullName_save(*fnamep, FALSE);
9621 	}
9622 	else
9623 	    p = *fnamep;
9624 
9625 	has_fullname = 0;
9626 
9627 	if (p != NULL)
9628 	{
9629 	    if (c == '.')
9630 	    {
9631 		mch_dirname(dirname, MAXPATHL);
9632 		s = shorten_fname(p, dirname);
9633 		if (s != NULL)
9634 		{
9635 		    *fnamep = s;
9636 		    if (pbuf != NULL)
9637 		    {
9638 			vim_free(*bufp);   /* free any allocated file name */
9639 			*bufp = pbuf;
9640 			pbuf = NULL;
9641 		    }
9642 		}
9643 	    }
9644 	    else
9645 	    {
9646 		home_replace(NULL, p, dirname, MAXPATHL, TRUE);
9647 		/* Only replace it when it starts with '~' */
9648 		if (*dirname == '~')
9649 		{
9650 		    s = vim_strsave(dirname);
9651 		    if (s != NULL)
9652 		    {
9653 			*fnamep = s;
9654 			vim_free(*bufp);
9655 			*bufp = s;
9656 		    }
9657 		}
9658 	    }
9659 	    vim_free(pbuf);
9660 	}
9661     }
9662 
9663     tail = gettail(*fnamep);
9664     *fnamelen = (int)STRLEN(*fnamep);
9665 
9666     /* ":h" - head, remove "/file_name", can be repeated  */
9667     /* Don't remove the first "/" or "c:\" */
9668     while (src[*usedlen] == ':' && src[*usedlen + 1] == 'h')
9669     {
9670 	valid |= VALID_HEAD;
9671 	*usedlen += 2;
9672 	s = get_past_head(*fnamep);
9673 	while (tail > s && after_pathsep(s, tail))
9674 	    mb_ptr_back(*fnamep, tail);
9675 	*fnamelen = (int)(tail - *fnamep);
9676 #ifdef VMS
9677 	if (*fnamelen > 0)
9678 	    *fnamelen += 1; /* the path separator is part of the path */
9679 #endif
9680 	if (*fnamelen == 0)
9681 	{
9682 	    /* Result is empty.  Turn it into "." to make ":cd %:h" work. */
9683 	    p = vim_strsave((char_u *)".");
9684 	    if (p == NULL)
9685 		return -1;
9686 	    vim_free(*bufp);
9687 	    *bufp = *fnamep = tail = p;
9688 	    *fnamelen = 1;
9689 	}
9690 	else
9691 	{
9692 	    while (tail > s && !after_pathsep(s, tail))
9693 		mb_ptr_back(*fnamep, tail);
9694 	}
9695     }
9696 
9697     /* ":8" - shortname  */
9698     if (src[*usedlen] == ':' && src[*usedlen + 1] == '8')
9699     {
9700 	*usedlen += 2;
9701 #ifdef WIN3264
9702 	has_shortname = 1;
9703 #endif
9704     }
9705 
9706 #ifdef WIN3264
9707     /*
9708      * Handle ":8" after we have done 'heads' and before we do 'tails'.
9709      */
9710     if (has_shortname)
9711     {
9712 	/* Copy the string if it is shortened by :h and when it wasn't copied
9713 	 * yet, because we are going to change it in place.  Avoids changing
9714 	 * the buffer name for "%:8". */
9715 	if (*fnamelen < (int)STRLEN(*fnamep) || *fnamep == fname_start)
9716 	{
9717 	    p = vim_strnsave(*fnamep, *fnamelen);
9718 	    if (p == NULL)
9719 		return -1;
9720 	    vim_free(*bufp);
9721 	    *bufp = *fnamep = p;
9722 	}
9723 
9724 	/* Split into two implementations - makes it easier.  First is where
9725 	 * there isn't a full name already, second is where there is. */
9726 	if (!has_fullname && !vim_isAbsName(*fnamep))
9727 	{
9728 	    if (shortpath_for_partial(fnamep, bufp, fnamelen) == FAIL)
9729 		return -1;
9730 	}
9731 	else
9732 	{
9733 	    int		l = *fnamelen;
9734 
9735 	    /* Simple case, already have the full-name.
9736 	     * Nearly always shorter, so try first time. */
9737 	    if (get_short_pathname(fnamep, bufp, &l) == FAIL)
9738 		return -1;
9739 
9740 	    if (l == 0)
9741 	    {
9742 		/* Couldn't find the filename, search the paths. */
9743 		l = *fnamelen;
9744 		if (shortpath_for_invalid_fname(fnamep, bufp, &l) == FAIL)
9745 		    return -1;
9746 	    }
9747 	    *fnamelen = l;
9748 	}
9749     }
9750 #endif /* WIN3264 */
9751 
9752     /* ":t" - tail, just the basename */
9753     if (src[*usedlen] == ':' && src[*usedlen + 1] == 't')
9754     {
9755 	*usedlen += 2;
9756 	*fnamelen -= (int)(tail - *fnamep);
9757 	*fnamep = tail;
9758     }
9759 
9760     /* ":e" - extension, can be repeated */
9761     /* ":r" - root, without extension, can be repeated */
9762     while (src[*usedlen] == ':'
9763 	    && (src[*usedlen + 1] == 'e' || src[*usedlen + 1] == 'r'))
9764     {
9765 	/* find a '.' in the tail:
9766 	 * - for second :e: before the current fname
9767 	 * - otherwise: The last '.'
9768 	 */
9769 	if (src[*usedlen + 1] == 'e' && *fnamep > tail)
9770 	    s = *fnamep - 2;
9771 	else
9772 	    s = *fnamep + *fnamelen - 1;
9773 	for ( ; s > tail; --s)
9774 	    if (s[0] == '.')
9775 		break;
9776 	if (src[*usedlen + 1] == 'e')		/* :e */
9777 	{
9778 	    if (s > tail)
9779 	    {
9780 		*fnamelen += (int)(*fnamep - (s + 1));
9781 		*fnamep = s + 1;
9782 #ifdef VMS
9783 		/* cut version from the extension */
9784 		s = *fnamep + *fnamelen - 1;
9785 		for ( ; s > *fnamep; --s)
9786 		    if (s[0] == ';')
9787 			break;
9788 		if (s > *fnamep)
9789 		    *fnamelen = s - *fnamep;
9790 #endif
9791 	    }
9792 	    else if (*fnamep <= tail)
9793 		*fnamelen = 0;
9794 	}
9795 	else				/* :r */
9796 	{
9797 	    if (s > tail)	/* remove one extension */
9798 		*fnamelen = (int)(s - *fnamep);
9799 	}
9800 	*usedlen += 2;
9801     }
9802 
9803     /* ":s?pat?foo?" - substitute */
9804     /* ":gs?pat?foo?" - global substitute */
9805     if (src[*usedlen] == ':'
9806 	    && (src[*usedlen + 1] == 's'
9807 		|| (src[*usedlen + 1] == 'g' && src[*usedlen + 2] == 's')))
9808     {
9809 	char_u	    *str;
9810 	char_u	    *pat;
9811 	char_u	    *sub;
9812 	int	    sep;
9813 	char_u	    *flags;
9814 	int	    didit = FALSE;
9815 
9816 	flags = (char_u *)"";
9817 	s = src + *usedlen + 2;
9818 	if (src[*usedlen + 1] == 'g')
9819 	{
9820 	    flags = (char_u *)"g";
9821 	    ++s;
9822 	}
9823 
9824 	sep = *s++;
9825 	if (sep)
9826 	{
9827 	    /* find end of pattern */
9828 	    p = vim_strchr(s, sep);
9829 	    if (p != NULL)
9830 	    {
9831 		pat = vim_strnsave(s, (int)(p - s));
9832 		if (pat != NULL)
9833 		{
9834 		    s = p + 1;
9835 		    /* find end of substitution */
9836 		    p = vim_strchr(s, sep);
9837 		    if (p != NULL)
9838 		    {
9839 			sub = vim_strnsave(s, (int)(p - s));
9840 			str = vim_strnsave(*fnamep, *fnamelen);
9841 			if (sub != NULL && str != NULL)
9842 			{
9843 			    *usedlen = (int)(p + 1 - src);
9844 			    s = do_string_sub(str, pat, sub, NULL, flags);
9845 			    if (s != NULL)
9846 			    {
9847 				*fnamep = s;
9848 				*fnamelen = (int)STRLEN(s);
9849 				vim_free(*bufp);
9850 				*bufp = s;
9851 				didit = TRUE;
9852 			    }
9853 			}
9854 			vim_free(sub);
9855 			vim_free(str);
9856 		    }
9857 		    vim_free(pat);
9858 		}
9859 	    }
9860 	    /* after using ":s", repeat all the modifiers */
9861 	    if (didit)
9862 		goto repeat;
9863 	}
9864     }
9865 
9866     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'S')
9867     {
9868 	/* vim_strsave_shellescape() needs a NUL terminated string. */
9869 	c = (*fnamep)[*fnamelen];
9870 	if (c != NUL)
9871 	    (*fnamep)[*fnamelen] = NUL;
9872 	p = vim_strsave_shellescape(*fnamep, FALSE, FALSE);
9873 	if (c != NUL)
9874 	    (*fnamep)[*fnamelen] = c;
9875 	if (p == NULL)
9876 	    return -1;
9877 	vim_free(*bufp);
9878 	*bufp = *fnamep = p;
9879 	*fnamelen = (int)STRLEN(p);
9880 	*usedlen += 2;
9881     }
9882 
9883     return valid;
9884 }
9885 
9886 /*
9887  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
9888  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
9889  * "flags" can be "g" to do a global substitute.
9890  * Returns an allocated string, NULL for error.
9891  */
9892     char_u *
9893 do_string_sub(
9894     char_u	*str,
9895     char_u	*pat,
9896     char_u	*sub,
9897     typval_T	*expr,
9898     char_u	*flags)
9899 {
9900     int		sublen;
9901     regmatch_T	regmatch;
9902     int		i;
9903     int		do_all;
9904     char_u	*tail;
9905     char_u	*end;
9906     garray_T	ga;
9907     char_u	*ret;
9908     char_u	*save_cpo;
9909     char_u	*zero_width = NULL;
9910 
9911     /* Make 'cpoptions' empty, so that the 'l' flag doesn't work here */
9912     save_cpo = p_cpo;
9913     p_cpo = empty_option;
9914 
9915     ga_init2(&ga, 1, 200);
9916 
9917     do_all = (flags[0] == 'g');
9918 
9919     regmatch.rm_ic = p_ic;
9920     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
9921     if (regmatch.regprog != NULL)
9922     {
9923 	tail = str;
9924 	end = str + STRLEN(str);
9925 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
9926 	{
9927 	    /* Skip empty match except for first match. */
9928 	    if (regmatch.startp[0] == regmatch.endp[0])
9929 	    {
9930 		if (zero_width == regmatch.startp[0])
9931 		{
9932 		    /* avoid getting stuck on a match with an empty string */
9933 		    i = MB_PTR2LEN(tail);
9934 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
9935 								   (size_t)i);
9936 		    ga.ga_len += i;
9937 		    tail += i;
9938 		    continue;
9939 		}
9940 		zero_width = regmatch.startp[0];
9941 	    }
9942 
9943 	    /*
9944 	     * Get some space for a temporary buffer to do the substitution
9945 	     * into.  It will contain:
9946 	     * - The text up to where the match is.
9947 	     * - The substituted text.
9948 	     * - The text after the match.
9949 	     */
9950 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
9951 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
9952 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
9953 	    {
9954 		ga_clear(&ga);
9955 		break;
9956 	    }
9957 
9958 	    /* copy the text up to where the match is */
9959 	    i = (int)(regmatch.startp[0] - tail);
9960 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
9961 	    /* add the substituted text */
9962 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
9963 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
9964 	    ga.ga_len += i + sublen - 1;
9965 	    tail = regmatch.endp[0];
9966 	    if (*tail == NUL)
9967 		break;
9968 	    if (!do_all)
9969 		break;
9970 	}
9971 
9972 	if (ga.ga_data != NULL)
9973 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
9974 
9975 	vim_regfree(regmatch.regprog);
9976     }
9977 
9978     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
9979     ga_clear(&ga);
9980     if (p_cpo == empty_option)
9981 	p_cpo = save_cpo;
9982     else
9983 	/* Darn, evaluating {sub} expression or {expr} changed the value. */
9984 	free_string_option(save_cpo);
9985 
9986     return ret;
9987 }
9988 
9989     static int
9990 filter_map_one(typval_T *tv, typval_T *expr, int map, int *remp)
9991 {
9992     typval_T	rettv;
9993     typval_T	argv[3];
9994     char_u	buf[NUMBUFLEN];
9995     char_u	*s;
9996     int		retval = FAIL;
9997     int		dummy;
9998 
9999     copy_tv(tv, &vimvars[VV_VAL].vv_tv);
10000     argv[0] = vimvars[VV_KEY].vv_tv;
10001     argv[1] = vimvars[VV_VAL].vv_tv;
10002     if (expr->v_type == VAR_FUNC)
10003     {
10004 	s = expr->vval.v_string;
10005 	if (call_func(s, (int)STRLEN(s), &rettv, 2, argv, NULL,
10006 				     0L, 0L, &dummy, TRUE, NULL, NULL) == FAIL)
10007 	    goto theend;
10008     }
10009     else if (expr->v_type == VAR_PARTIAL)
10010     {
10011 	partial_T   *partial = expr->vval.v_partial;
10012 
10013 	s = partial_name(partial);
10014 	if (call_func(s, (int)STRLEN(s), &rettv, 2, argv, NULL,
10015 				  0L, 0L, &dummy, TRUE, partial, NULL) == FAIL)
10016 	    goto theend;
10017     }
10018     else
10019     {
10020 	s = get_tv_string_buf_chk(expr, buf);
10021 	if (s == NULL)
10022 	    goto theend;
10023 	s = skipwhite(s);
10024 	if (eval1(&s, &rettv, TRUE) == FAIL)
10025 	    goto theend;
10026 	if (*s != NUL)  /* check for trailing chars after expr */
10027 	{
10028 	    EMSG2(_(e_invexpr2), s);
10029 	    goto theend;
10030 	}
10031     }
10032     if (map)
10033     {
10034 	/* map(): replace the list item value */
10035 	clear_tv(tv);
10036 	rettv.v_lock = 0;
10037 	*tv = rettv;
10038     }
10039     else
10040     {
10041 	int	    error = FALSE;
10042 
10043 	/* filter(): when expr is zero remove the item */
10044 	*remp = (get_tv_number_chk(&rettv, &error) == 0);
10045 	clear_tv(&rettv);
10046 	/* On type error, nothing has been removed; return FAIL to stop the
10047 	 * loop.  The error message was given by get_tv_number_chk(). */
10048 	if (error)
10049 	    goto theend;
10050     }
10051     retval = OK;
10052 theend:
10053     clear_tv(&vimvars[VV_VAL].vv_tv);
10054     return retval;
10055 }
10056 
10057 
10058 /*
10059  * Implementation of map() and filter().
10060  */
10061     void
10062 filter_map(typval_T *argvars, typval_T *rettv, int map)
10063 {
10064     typval_T	*expr;
10065     listitem_T	*li, *nli;
10066     list_T	*l = NULL;
10067     dictitem_T	*di;
10068     hashtab_T	*ht;
10069     hashitem_T	*hi;
10070     dict_T	*d = NULL;
10071     typval_T	save_val;
10072     typval_T	save_key;
10073     int		rem;
10074     int		todo;
10075     char_u	*ermsg = (char_u *)(map ? "map()" : "filter()");
10076     char_u	*arg_errmsg = (char_u *)(map ? N_("map() argument")
10077 				   : N_("filter() argument"));
10078     int		save_did_emsg;
10079     int		idx = 0;
10080 
10081     if (argvars[0].v_type == VAR_LIST)
10082     {
10083 	if ((l = argvars[0].vval.v_list) == NULL
10084 	      || (!map && tv_check_lock(l->lv_lock, arg_errmsg, TRUE)))
10085 	    return;
10086     }
10087     else if (argvars[0].v_type == VAR_DICT)
10088     {
10089 	if ((d = argvars[0].vval.v_dict) == NULL
10090 	      || (!map && tv_check_lock(d->dv_lock, arg_errmsg, TRUE)))
10091 	    return;
10092     }
10093     else
10094     {
10095 	EMSG2(_(e_listdictarg), ermsg);
10096 	return;
10097     }
10098 
10099     expr = &argvars[1];
10100     /* On type errors, the preceding call has already displayed an error
10101      * message.  Avoid a misleading error message for an empty string that
10102      * was not passed as argument. */
10103     if (expr->v_type != VAR_UNKNOWN)
10104     {
10105 	prepare_vimvar(VV_VAL, &save_val);
10106 
10107 	/* We reset "did_emsg" to be able to detect whether an error
10108 	 * occurred during evaluation of the expression. */
10109 	save_did_emsg = did_emsg;
10110 	did_emsg = FALSE;
10111 
10112 	prepare_vimvar(VV_KEY, &save_key);
10113 	if (argvars[0].v_type == VAR_DICT)
10114 	{
10115 	    vimvars[VV_KEY].vv_type = VAR_STRING;
10116 
10117 	    ht = &d->dv_hashtab;
10118 	    hash_lock(ht);
10119 	    todo = (int)ht->ht_used;
10120 	    for (hi = ht->ht_array; todo > 0; ++hi)
10121 	    {
10122 		if (!HASHITEM_EMPTY(hi))
10123 		{
10124 		    int r;
10125 
10126 		    --todo;
10127 		    di = HI2DI(hi);
10128 		    if (map &&
10129 			    (tv_check_lock(di->di_tv.v_lock, arg_errmsg, TRUE)
10130 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE)))
10131 			break;
10132 		    vimvars[VV_KEY].vv_str = vim_strsave(di->di_key);
10133 		    r = filter_map_one(&di->di_tv, expr, map, &rem);
10134 		    clear_tv(&vimvars[VV_KEY].vv_tv);
10135 		    if (r == FAIL || did_emsg)
10136 			break;
10137 		    if (!map && rem)
10138 		    {
10139 			if (var_check_fixed(di->di_flags, arg_errmsg, TRUE)
10140 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE))
10141 			    break;
10142 			dictitem_remove(d, di);
10143 		    }
10144 		}
10145 	    }
10146 	    hash_unlock(ht);
10147 	}
10148 	else
10149 	{
10150 	    vimvars[VV_KEY].vv_type = VAR_NUMBER;
10151 
10152 	    for (li = l->lv_first; li != NULL; li = nli)
10153 	    {
10154 		if (map && tv_check_lock(li->li_tv.v_lock, arg_errmsg, TRUE))
10155 		    break;
10156 		nli = li->li_next;
10157 		vimvars[VV_KEY].vv_nr = idx;
10158 		if (filter_map_one(&li->li_tv, expr, map, &rem) == FAIL
10159 								  || did_emsg)
10160 		    break;
10161 		if (!map && rem)
10162 		    listitem_remove(l, li);
10163 		++idx;
10164 	    }
10165 	}
10166 
10167 	restore_vimvar(VV_KEY, &save_key);
10168 	restore_vimvar(VV_VAL, &save_val);
10169 
10170 	did_emsg |= save_did_emsg;
10171     }
10172 
10173     copy_tv(&argvars[0], rettv);
10174 }
10175 
10176 #endif /* defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) */
10177