xref: /vim-8.2.3635/src/eval.c (revision 89eaa418)
1 /* vi:set ts=8 sts=4 sw=4:
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 
237 
238 static int get_env_len(char_u **arg);
239 static char_u * make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
240 static void check_vars(char_u *name, int len);
241 static typval_T *alloc_string_tv(char_u *string);
242 static void delete_var(hashtab_T *ht, hashitem_T *hi);
243 static void list_one_var(dictitem_T *v, char_u *prefix, int *first);
244 static void list_one_var_a(char_u *prefix, char_u *name, int type, char_u *string, int *first);
245 static char_u *find_option_end(char_u **arg, int *opt_flags);
246 
247 #ifdef EBCDIC
248 static int compare_func_name(const void *s1, const void *s2);
249 static void sortFunctions();
250 #endif
251 
252 /* for VIM_VERSION_ defines */
253 #include "version.h"
254 
255 /*
256  * Initialize the global and v: variables.
257  */
258     void
259 eval_init(void)
260 {
261     int		    i;
262     struct vimvar   *p;
263 
264     init_var_dict(&globvardict, &globvars_var, VAR_DEF_SCOPE);
265     init_var_dict(&vimvardict, &vimvars_var, VAR_SCOPE);
266     vimvardict.dv_lock = VAR_FIXED;
267     hash_init(&compat_hashtab);
268     func_init();
269 
270     for (i = 0; i < VV_LEN; ++i)
271     {
272 	p = &vimvars[i];
273 	if (STRLEN(p->vv_name) > 16)
274 	{
275 	    EMSG("INTERNAL: name too long, increase size of dictitem16_T");
276 	    getout(1);
277 	}
278 	STRCPY(p->vv_di.di_key, p->vv_name);
279 	if (p->vv_flags & VV_RO)
280 	    p->vv_di.di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
281 	else if (p->vv_flags & VV_RO_SBX)
282 	    p->vv_di.di_flags = DI_FLAGS_RO_SBX | DI_FLAGS_FIX;
283 	else
284 	    p->vv_di.di_flags = DI_FLAGS_FIX;
285 
286 	/* add to v: scope dict, unless the value is not always available */
287 	if (p->vv_type != VAR_UNKNOWN)
288 	    hash_add(&vimvarht, p->vv_di.di_key);
289 	if (p->vv_flags & VV_COMPAT)
290 	    /* add to compat scope dict */
291 	    hash_add(&compat_hashtab, p->vv_di.di_key);
292     }
293     vimvars[VV_VERSION].vv_nr = VIM_VERSION_100;
294 
295     set_vim_var_nr(VV_SEARCHFORWARD, 1L);
296     set_vim_var_nr(VV_HLSEARCH, 1L);
297     set_vim_var_dict(VV_COMPLETED_ITEM, dict_alloc());
298     set_vim_var_list(VV_ERRORS, list_alloc());
299 
300     set_vim_var_nr(VV_FALSE, VVAL_FALSE);
301     set_vim_var_nr(VV_TRUE, VVAL_TRUE);
302     set_vim_var_nr(VV_NONE, VVAL_NONE);
303     set_vim_var_nr(VV_NULL, VVAL_NULL);
304 
305     set_vim_var_nr(VV_TYPE_NUMBER,  VAR_TYPE_NUMBER);
306     set_vim_var_nr(VV_TYPE_STRING,  VAR_TYPE_STRING);
307     set_vim_var_nr(VV_TYPE_FUNC,    VAR_TYPE_FUNC);
308     set_vim_var_nr(VV_TYPE_LIST,    VAR_TYPE_LIST);
309     set_vim_var_nr(VV_TYPE_DICT,    VAR_TYPE_DICT);
310     set_vim_var_nr(VV_TYPE_FLOAT,   VAR_TYPE_FLOAT);
311     set_vim_var_nr(VV_TYPE_BOOL,    VAR_TYPE_BOOL);
312     set_vim_var_nr(VV_TYPE_NONE,    VAR_TYPE_NONE);
313     set_vim_var_nr(VV_TYPE_JOB,     VAR_TYPE_JOB);
314     set_vim_var_nr(VV_TYPE_CHANNEL, VAR_TYPE_CHANNEL);
315 
316     set_reg_var(0);  /* default for v:register is not 0 but '"' */
317 
318 #ifdef EBCDIC
319     /*
320      * Sort the function table, to enable binary search.
321      */
322     sortFunctions();
323 #endif
324 }
325 
326 #if defined(EXITFREE) || defined(PROTO)
327     void
328 eval_clear(void)
329 {
330     int		    i;
331     struct vimvar   *p;
332 
333     for (i = 0; i < VV_LEN; ++i)
334     {
335 	p = &vimvars[i];
336 	if (p->vv_di.di_tv.v_type == VAR_STRING)
337 	{
338 	    vim_free(p->vv_str);
339 	    p->vv_str = NULL;
340 	}
341 	else if (p->vv_di.di_tv.v_type == VAR_LIST)
342 	{
343 	    list_unref(p->vv_list);
344 	    p->vv_list = NULL;
345 	}
346     }
347     hash_clear(&vimvarht);
348     hash_init(&vimvarht);  /* garbage_collect() will access it */
349     hash_clear(&compat_hashtab);
350 
351     free_scriptnames();
352 # if defined(FEAT_CMDL_COMPL)
353     free_locales();
354 # endif
355 
356     /* global variables */
357     vars_clear(&globvarht);
358 
359     /* autoloaded script names */
360     ga_clear_strings(&ga_loaded);
361 
362     /* Script-local variables. First clear all the variables and in a second
363      * loop free the scriptvar_T, because a variable in one script might hold
364      * a reference to the whole scope of another script. */
365     for (i = 1; i <= ga_scripts.ga_len; ++i)
366 	vars_clear(&SCRIPT_VARS(i));
367     for (i = 1; i <= ga_scripts.ga_len; ++i)
368 	vim_free(SCRIPT_SV(i));
369     ga_clear(&ga_scripts);
370 
371     /* unreferenced lists and dicts */
372     (void)garbage_collect(FALSE);
373 
374     /* functions */
375     free_all_functions();
376 }
377 #endif
378 
379 
380 /*
381  * Set an internal variable to a string value. Creates the variable if it does
382  * not already exist.
383  */
384     void
385 set_internal_string_var(char_u *name, char_u *value)
386 {
387     char_u	*val;
388     typval_T	*tvp;
389 
390     val = vim_strsave(value);
391     if (val != NULL)
392     {
393 	tvp = alloc_string_tv(val);
394 	if (tvp != NULL)
395 	{
396 	    set_var(name, tvp, FALSE);
397 	    free_tv(tvp);
398 	}
399     }
400 }
401 
402 static lval_T	*redir_lval = NULL;
403 #define EVALCMD_BUSY (redir_lval == (lval_T *)&redir_lval)
404 static garray_T redir_ga;	/* only valid when redir_lval is not NULL */
405 static char_u	*redir_endp = NULL;
406 static char_u	*redir_varname = NULL;
407 
408 /*
409  * Start recording command output to a variable
410  * When "append" is TRUE append to an existing variable.
411  * Returns OK if successfully completed the setup.  FAIL otherwise.
412  */
413     int
414 var_redir_start(char_u *name, int append)
415 {
416     int		save_emsg;
417     int		err;
418     typval_T	tv;
419 
420     /* Catch a bad name early. */
421     if (!eval_isnamec1(*name))
422     {
423 	EMSG(_(e_invarg));
424 	return FAIL;
425     }
426 
427     /* Make a copy of the name, it is used in redir_lval until redir ends. */
428     redir_varname = vim_strsave(name);
429     if (redir_varname == NULL)
430 	return FAIL;
431 
432     redir_lval = (lval_T *)alloc_clear((unsigned)sizeof(lval_T));
433     if (redir_lval == NULL)
434     {
435 	var_redir_stop();
436 	return FAIL;
437     }
438 
439     /* The output is stored in growarray "redir_ga" until redirection ends. */
440     ga_init2(&redir_ga, (int)sizeof(char), 500);
441 
442     /* Parse the variable name (can be a dict or list entry). */
443     redir_endp = get_lval(redir_varname, NULL, redir_lval, FALSE, FALSE, 0,
444 							     FNE_CHECK_START);
445     if (redir_endp == NULL || redir_lval->ll_name == NULL || *redir_endp != NUL)
446     {
447 	clear_lval(redir_lval);
448 	if (redir_endp != NULL && *redir_endp != NUL)
449 	    /* Trailing characters are present after the variable name */
450 	    EMSG(_(e_trailing));
451 	else
452 	    EMSG(_(e_invarg));
453 	redir_endp = NULL;  /* don't store a value, only cleanup */
454 	var_redir_stop();
455 	return FAIL;
456     }
457 
458     /* check if we can write to the variable: set it to or append an empty
459      * string */
460     save_emsg = did_emsg;
461     did_emsg = FALSE;
462     tv.v_type = VAR_STRING;
463     tv.vval.v_string = (char_u *)"";
464     if (append)
465 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, (char_u *)".");
466     else
467 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, (char_u *)"=");
468     clear_lval(redir_lval);
469     err = did_emsg;
470     did_emsg |= save_emsg;
471     if (err)
472     {
473 	redir_endp = NULL;  /* don't store a value, only cleanup */
474 	var_redir_stop();
475 	return FAIL;
476     }
477 
478     return OK;
479 }
480 
481 /*
482  * Append "value[value_len]" to the variable set by var_redir_start().
483  * The actual appending is postponed until redirection ends, because the value
484  * appended may in fact be the string we write to, changing it may cause freed
485  * memory to be used:
486  *   :redir => foo
487  *   :let foo
488  *   :redir END
489  */
490     void
491 var_redir_str(char_u *value, int value_len)
492 {
493     int		len;
494 
495     if (redir_lval == NULL)
496 	return;
497 
498     if (value_len == -1)
499 	len = (int)STRLEN(value);	/* Append the entire string */
500     else
501 	len = value_len;		/* Append only "value_len" characters */
502 
503     if (ga_grow(&redir_ga, len) == OK)
504     {
505 	mch_memmove((char *)redir_ga.ga_data + redir_ga.ga_len, value, len);
506 	redir_ga.ga_len += len;
507     }
508     else
509 	var_redir_stop();
510 }
511 
512 /*
513  * Stop redirecting command output to a variable.
514  * Frees the allocated memory.
515  */
516     void
517 var_redir_stop(void)
518 {
519     typval_T	tv;
520 
521     if (EVALCMD_BUSY)
522     {
523 	redir_lval = NULL;
524 	return;
525     }
526 
527     if (redir_lval != NULL)
528     {
529 	/* If there was no error: assign the text to the variable. */
530 	if (redir_endp != NULL)
531 	{
532 	    ga_append(&redir_ga, NUL);  /* Append the trailing NUL. */
533 	    tv.v_type = VAR_STRING;
534 	    tv.vval.v_string = redir_ga.ga_data;
535 	    /* Call get_lval() again, if it's inside a Dict or List it may
536 	     * have changed. */
537 	    redir_endp = get_lval(redir_varname, NULL, redir_lval,
538 					FALSE, FALSE, 0, FNE_CHECK_START);
539 	    if (redir_endp != NULL && redir_lval->ll_name != NULL)
540 		set_var_lval(redir_lval, redir_endp, &tv, FALSE, (char_u *)".");
541 	    clear_lval(redir_lval);
542 	}
543 
544 	/* free the collected output */
545 	vim_free(redir_ga.ga_data);
546 	redir_ga.ga_data = NULL;
547 
548 	vim_free(redir_lval);
549 	redir_lval = NULL;
550     }
551     vim_free(redir_varname);
552     redir_varname = NULL;
553 }
554 
555 # if defined(FEAT_MBYTE) || defined(PROTO)
556     int
557 eval_charconvert(
558     char_u	*enc_from,
559     char_u	*enc_to,
560     char_u	*fname_from,
561     char_u	*fname_to)
562 {
563     int		err = FALSE;
564 
565     set_vim_var_string(VV_CC_FROM, enc_from, -1);
566     set_vim_var_string(VV_CC_TO, enc_to, -1);
567     set_vim_var_string(VV_FNAME_IN, fname_from, -1);
568     set_vim_var_string(VV_FNAME_OUT, fname_to, -1);
569     if (eval_to_bool(p_ccv, &err, NULL, FALSE))
570 	err = TRUE;
571     set_vim_var_string(VV_CC_FROM, NULL, -1);
572     set_vim_var_string(VV_CC_TO, NULL, -1);
573     set_vim_var_string(VV_FNAME_IN, NULL, -1);
574     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
575 
576     if (err)
577 	return FAIL;
578     return OK;
579 }
580 # endif
581 
582 # if defined(FEAT_POSTSCRIPT) || defined(PROTO)
583     int
584 eval_printexpr(char_u *fname, char_u *args)
585 {
586     int		err = FALSE;
587 
588     set_vim_var_string(VV_FNAME_IN, fname, -1);
589     set_vim_var_string(VV_CMDARG, args, -1);
590     if (eval_to_bool(p_pexpr, &err, NULL, FALSE))
591 	err = TRUE;
592     set_vim_var_string(VV_FNAME_IN, NULL, -1);
593     set_vim_var_string(VV_CMDARG, NULL, -1);
594 
595     if (err)
596     {
597 	mch_remove(fname);
598 	return FAIL;
599     }
600     return OK;
601 }
602 # endif
603 
604 # if defined(FEAT_DIFF) || defined(PROTO)
605     void
606 eval_diff(
607     char_u	*origfile,
608     char_u	*newfile,
609     char_u	*outfile)
610 {
611     int		err = FALSE;
612 
613     set_vim_var_string(VV_FNAME_IN, origfile, -1);
614     set_vim_var_string(VV_FNAME_NEW, newfile, -1);
615     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
616     (void)eval_to_bool(p_dex, &err, NULL, FALSE);
617     set_vim_var_string(VV_FNAME_IN, NULL, -1);
618     set_vim_var_string(VV_FNAME_NEW, NULL, -1);
619     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
620 }
621 
622     void
623 eval_patch(
624     char_u	*origfile,
625     char_u	*difffile,
626     char_u	*outfile)
627 {
628     int		err;
629 
630     set_vim_var_string(VV_FNAME_IN, origfile, -1);
631     set_vim_var_string(VV_FNAME_DIFF, difffile, -1);
632     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
633     (void)eval_to_bool(p_pex, &err, NULL, FALSE);
634     set_vim_var_string(VV_FNAME_IN, NULL, -1);
635     set_vim_var_string(VV_FNAME_DIFF, NULL, -1);
636     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
637 }
638 # endif
639 
640 /*
641  * Top level evaluation function, returning a boolean.
642  * Sets "error" to TRUE if there was an error.
643  * Return TRUE or FALSE.
644  */
645     int
646 eval_to_bool(
647     char_u	*arg,
648     int		*error,
649     char_u	**nextcmd,
650     int		skip)	    /* only parse, don't execute */
651 {
652     typval_T	tv;
653     varnumber_T	retval = FALSE;
654 
655     if (skip)
656 	++emsg_skip;
657     if (eval0(arg, &tv, nextcmd, !skip) == FAIL)
658 	*error = TRUE;
659     else
660     {
661 	*error = FALSE;
662 	if (!skip)
663 	{
664 	    retval = (get_tv_number_chk(&tv, error) != 0);
665 	    clear_tv(&tv);
666 	}
667     }
668     if (skip)
669 	--emsg_skip;
670 
671     return (int)retval;
672 }
673 
674 /*
675  * Top level evaluation function, returning a string.  If "skip" is TRUE,
676  * only parsing to "nextcmd" is done, without reporting errors.  Return
677  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
678  */
679     char_u *
680 eval_to_string_skip(
681     char_u	*arg,
682     char_u	**nextcmd,
683     int		skip)	    /* only parse, don't execute */
684 {
685     typval_T	tv;
686     char_u	*retval;
687 
688     if (skip)
689 	++emsg_skip;
690     if (eval0(arg, &tv, nextcmd, !skip) == FAIL || skip)
691 	retval = NULL;
692     else
693     {
694 	retval = vim_strsave(get_tv_string(&tv));
695 	clear_tv(&tv);
696     }
697     if (skip)
698 	--emsg_skip;
699 
700     return retval;
701 }
702 
703 /*
704  * Skip over an expression at "*pp".
705  * Return FAIL for an error, OK otherwise.
706  */
707     int
708 skip_expr(char_u **pp)
709 {
710     typval_T	rettv;
711 
712     *pp = skipwhite(*pp);
713     return eval1(pp, &rettv, FALSE);
714 }
715 
716 /*
717  * Top level evaluation function, returning a string.
718  * When "convert" is TRUE convert a List into a sequence of lines and convert
719  * a Float to a String.
720  * Return pointer to allocated memory, or NULL for failure.
721  */
722     char_u *
723 eval_to_string(
724     char_u	*arg,
725     char_u	**nextcmd,
726     int		convert)
727 {
728     typval_T	tv;
729     char_u	*retval;
730     garray_T	ga;
731 #ifdef FEAT_FLOAT
732     char_u	numbuf[NUMBUFLEN];
733 #endif
734 
735     if (eval0(arg, &tv, nextcmd, TRUE) == FAIL)
736 	retval = NULL;
737     else
738     {
739 	if (convert && tv.v_type == VAR_LIST)
740 	{
741 	    ga_init2(&ga, (int)sizeof(char), 80);
742 	    if (tv.vval.v_list != NULL)
743 	    {
744 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
745 		if (tv.vval.v_list->lv_len > 0)
746 		    ga_append(&ga, NL);
747 	    }
748 	    ga_append(&ga, NUL);
749 	    retval = (char_u *)ga.ga_data;
750 	}
751 #ifdef FEAT_FLOAT
752 	else if (convert && tv.v_type == VAR_FLOAT)
753 	{
754 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
755 	    retval = vim_strsave(numbuf);
756 	}
757 #endif
758 	else
759 	    retval = vim_strsave(get_tv_string(&tv));
760 	clear_tv(&tv);
761     }
762 
763     return retval;
764 }
765 
766 /*
767  * Call eval_to_string() without using current local variables and using
768  * textlock.  When "use_sandbox" is TRUE use the sandbox.
769  */
770     char_u *
771 eval_to_string_safe(
772     char_u	*arg,
773     char_u	**nextcmd,
774     int		use_sandbox)
775 {
776     char_u	*retval;
777     void	*save_funccalp;
778 
779     save_funccalp = save_funccal();
780     if (use_sandbox)
781 	++sandbox;
782     ++textlock;
783     retval = eval_to_string(arg, nextcmd, FALSE);
784     if (use_sandbox)
785 	--sandbox;
786     --textlock;
787     restore_funccal(save_funccalp);
788     return retval;
789 }
790 
791 /*
792  * Top level evaluation function, returning a number.
793  * Evaluates "expr" silently.
794  * Returns -1 for an error.
795  */
796     varnumber_T
797 eval_to_number(char_u *expr)
798 {
799     typval_T	rettv;
800     varnumber_T	retval;
801     char_u	*p = skipwhite(expr);
802 
803     ++emsg_off;
804 
805     if (eval1(&p, &rettv, TRUE) == FAIL)
806 	retval = -1;
807     else
808     {
809 	retval = get_tv_number_chk(&rettv, NULL);
810 	clear_tv(&rettv);
811     }
812     --emsg_off;
813 
814     return retval;
815 }
816 
817 /*
818  * Prepare v: variable "idx" to be used.
819  * Save the current typeval in "save_tv".
820  * When not used yet add the variable to the v: hashtable.
821  */
822     static void
823 prepare_vimvar(int idx, typval_T *save_tv)
824 {
825     *save_tv = vimvars[idx].vv_tv;
826     if (vimvars[idx].vv_type == VAR_UNKNOWN)
827 	hash_add(&vimvarht, vimvars[idx].vv_di.di_key);
828 }
829 
830 /*
831  * Restore v: variable "idx" to typeval "save_tv".
832  * When no longer defined, remove the variable from the v: hashtable.
833  */
834     static void
835 restore_vimvar(int idx, typval_T *save_tv)
836 {
837     hashitem_T	*hi;
838 
839     vimvars[idx].vv_tv = *save_tv;
840     if (vimvars[idx].vv_type == VAR_UNKNOWN)
841     {
842 	hi = hash_find(&vimvarht, vimvars[idx].vv_di.di_key);
843 	if (HASHITEM_EMPTY(hi))
844 	    EMSG2(_(e_intern2), "restore_vimvar()");
845 	else
846 	    hash_remove(&vimvarht, hi);
847     }
848 }
849 
850 #if defined(FEAT_SPELL) || defined(PROTO)
851 /*
852  * Evaluate an expression to a list with suggestions.
853  * For the "expr:" part of 'spellsuggest'.
854  * Returns NULL when there is an error.
855  */
856     list_T *
857 eval_spell_expr(char_u *badword, char_u *expr)
858 {
859     typval_T	save_val;
860     typval_T	rettv;
861     list_T	*list = NULL;
862     char_u	*p = skipwhite(expr);
863 
864     /* Set "v:val" to the bad word. */
865     prepare_vimvar(VV_VAL, &save_val);
866     vimvars[VV_VAL].vv_type = VAR_STRING;
867     vimvars[VV_VAL].vv_str = badword;
868     if (p_verbose == 0)
869 	++emsg_off;
870 
871     if (eval1(&p, &rettv, TRUE) == OK)
872     {
873 	if (rettv.v_type != VAR_LIST)
874 	    clear_tv(&rettv);
875 	else
876 	    list = rettv.vval.v_list;
877     }
878 
879     if (p_verbose == 0)
880 	--emsg_off;
881     restore_vimvar(VV_VAL, &save_val);
882 
883     return list;
884 }
885 
886 /*
887  * "list" is supposed to contain two items: a word and a number.  Return the
888  * word in "pp" and the number as the return value.
889  * Return -1 if anything isn't right.
890  * Used to get the good word and score from the eval_spell_expr() result.
891  */
892     int
893 get_spellword(list_T *list, char_u **pp)
894 {
895     listitem_T	*li;
896 
897     li = list->lv_first;
898     if (li == NULL)
899 	return -1;
900     *pp = get_tv_string(&li->li_tv);
901 
902     li = li->li_next;
903     if (li == NULL)
904 	return -1;
905     return (int)get_tv_number(&li->li_tv);
906 }
907 #endif
908 
909 /*
910  * Top level evaluation function.
911  * Returns an allocated typval_T with the result.
912  * Returns NULL when there is an error.
913  */
914     typval_T *
915 eval_expr(char_u *arg, char_u **nextcmd)
916 {
917     typval_T	*tv;
918 
919     tv = (typval_T *)alloc(sizeof(typval_T));
920     if (tv != NULL && eval0(arg, tv, nextcmd, TRUE) == FAIL)
921     {
922 	vim_free(tv);
923 	tv = NULL;
924     }
925 
926     return tv;
927 }
928 
929 
930 /*
931  * Call some vimL function and return the result in "*rettv".
932  * Uses argv[argc] for the function arguments.  Only Number and String
933  * arguments are currently supported.
934  * Returns OK or FAIL.
935  */
936     int
937 call_vim_function(
938     char_u      *func,
939     int		argc,
940     char_u      **argv,
941     int		safe,		/* use the sandbox */
942     int		str_arg_only,	/* all arguments are strings */
943     typval_T	*rettv)
944 {
945     typval_T	*argvars;
946     varnumber_T	n;
947     int		len;
948     int		i;
949     int		doesrange;
950     void	*save_funccalp = NULL;
951     int		ret;
952 
953     argvars = (typval_T *)alloc((unsigned)((argc + 1) * sizeof(typval_T)));
954     if (argvars == NULL)
955 	return FAIL;
956 
957     for (i = 0; i < argc; i++)
958     {
959 	/* Pass a NULL or empty argument as an empty string */
960 	if (argv[i] == NULL || *argv[i] == NUL)
961 	{
962 	    argvars[i].v_type = VAR_STRING;
963 	    argvars[i].vval.v_string = (char_u *)"";
964 	    continue;
965 	}
966 
967 	if (str_arg_only)
968 	    len = 0;
969 	else
970 	    /* Recognize a number argument, the others must be strings. */
971 	    vim_str2nr(argv[i], NULL, &len, STR2NR_ALL, &n, NULL, 0);
972 	if (len != 0 && len == (int)STRLEN(argv[i]))
973 	{
974 	    argvars[i].v_type = VAR_NUMBER;
975 	    argvars[i].vval.v_number = n;
976 	}
977 	else
978 	{
979 	    argvars[i].v_type = VAR_STRING;
980 	    argvars[i].vval.v_string = argv[i];
981 	}
982     }
983 
984     if (safe)
985     {
986 	save_funccalp = save_funccal();
987 	++sandbox;
988     }
989 
990     rettv->v_type = VAR_UNKNOWN;		/* clear_tv() uses this */
991     ret = call_func(func, (int)STRLEN(func), rettv, argc, argvars, NULL,
992 		    curwin->w_cursor.lnum, curwin->w_cursor.lnum,
993 		    &doesrange, TRUE, NULL, NULL);
994     if (safe)
995     {
996 	--sandbox;
997 	restore_funccal(save_funccalp);
998     }
999     vim_free(argvars);
1000 
1001     if (ret == FAIL)
1002 	clear_tv(rettv);
1003 
1004     return ret;
1005 }
1006 
1007 /*
1008  * Call vimL function "func" and return the result as a number.
1009  * Returns -1 when calling the function fails.
1010  * Uses argv[argc] for the function arguments.
1011  */
1012     varnumber_T
1013 call_func_retnr(
1014     char_u      *func,
1015     int		argc,
1016     char_u      **argv,
1017     int		safe)		/* use the sandbox */
1018 {
1019     typval_T	rettv;
1020     varnumber_T	retval;
1021 
1022     /* All arguments are passed as strings, no conversion to number. */
1023     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
1024 	return -1;
1025 
1026     retval = get_tv_number_chk(&rettv, NULL);
1027     clear_tv(&rettv);
1028     return retval;
1029 }
1030 
1031 #if (defined(FEAT_USR_CMDS) && defined(FEAT_CMDL_COMPL)) \
1032 	|| defined(FEAT_COMPL_FUNC) || defined(PROTO)
1033 
1034 # if (defined(FEAT_USR_CMDS) && defined(FEAT_CMDL_COMPL)) || defined(PROTO)
1035 /*
1036  * Call vimL function "func" and return the result as a string.
1037  * Returns NULL when calling the function fails.
1038  * Uses argv[argc] for the function arguments.
1039  */
1040     void *
1041 call_func_retstr(
1042     char_u      *func,
1043     int		argc,
1044     char_u      **argv,
1045     int		safe)		/* use the sandbox */
1046 {
1047     typval_T	rettv;
1048     char_u	*retval;
1049 
1050     /* All arguments are passed as strings, no conversion to number. */
1051     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
1052 	return NULL;
1053 
1054     retval = vim_strsave(get_tv_string(&rettv));
1055     clear_tv(&rettv);
1056     return retval;
1057 }
1058 # endif
1059 
1060 /*
1061  * Call vimL function "func" and return the result as a List.
1062  * Uses argv[argc] for the function arguments.
1063  * Returns NULL when there is something wrong.
1064  */
1065     void *
1066 call_func_retlist(
1067     char_u      *func,
1068     int		argc,
1069     char_u      **argv,
1070     int		safe)		/* use the sandbox */
1071 {
1072     typval_T	rettv;
1073 
1074     /* All arguments are passed as strings, no conversion to number. */
1075     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
1076 	return NULL;
1077 
1078     if (rettv.v_type != VAR_LIST)
1079     {
1080 	clear_tv(&rettv);
1081 	return NULL;
1082     }
1083 
1084     return rettv.vval.v_list;
1085 }
1086 #endif
1087 
1088 
1089 #ifdef FEAT_FOLDING
1090 /*
1091  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
1092  * it in "*cp".  Doesn't give error messages.
1093  */
1094     int
1095 eval_foldexpr(char_u *arg, int *cp)
1096 {
1097     typval_T	tv;
1098     varnumber_T	retval;
1099     char_u	*s;
1100     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
1101 								   OPT_LOCAL);
1102 
1103     ++emsg_off;
1104     if (use_sandbox)
1105 	++sandbox;
1106     ++textlock;
1107     *cp = NUL;
1108     if (eval0(arg, &tv, NULL, TRUE) == FAIL)
1109 	retval = 0;
1110     else
1111     {
1112 	/* If the result is a number, just return the number. */
1113 	if (tv.v_type == VAR_NUMBER)
1114 	    retval = tv.vval.v_number;
1115 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
1116 	    retval = 0;
1117 	else
1118 	{
1119 	    /* If the result is a string, check if there is a non-digit before
1120 	     * the number. */
1121 	    s = tv.vval.v_string;
1122 	    if (!VIM_ISDIGIT(*s) && *s != '-')
1123 		*cp = *s++;
1124 	    retval = atol((char *)s);
1125 	}
1126 	clear_tv(&tv);
1127     }
1128     --emsg_off;
1129     if (use_sandbox)
1130 	--sandbox;
1131     --textlock;
1132 
1133     return (int)retval;
1134 }
1135 #endif
1136 
1137 /*
1138  * ":let"			list all variable values
1139  * ":let var1 var2"		list variable values
1140  * ":let var = expr"		assignment command.
1141  * ":let var += expr"		assignment command.
1142  * ":let var -= expr"		assignment command.
1143  * ":let var .= expr"		assignment command.
1144  * ":let [var1, var2] = expr"	unpack list.
1145  */
1146     void
1147 ex_let(exarg_T *eap)
1148 {
1149     char_u	*arg = eap->arg;
1150     char_u	*expr = NULL;
1151     typval_T	rettv;
1152     int		i;
1153     int		var_count = 0;
1154     int		semicolon = 0;
1155     char_u	op[2];
1156     char_u	*argend;
1157     int		first = TRUE;
1158 
1159     argend = skip_var_list(arg, &var_count, &semicolon);
1160     if (argend == NULL)
1161 	return;
1162     if (argend > arg && argend[-1] == '.')  /* for var.='str' */
1163 	--argend;
1164     expr = skipwhite(argend);
1165     if (*expr != '=' && !(vim_strchr((char_u *)"+-.", *expr) != NULL
1166 			  && expr[1] == '='))
1167     {
1168 	/*
1169 	 * ":let" without "=": list variables
1170 	 */
1171 	if (*arg == '[')
1172 	    EMSG(_(e_invarg));
1173 	else if (!ends_excmd(*arg))
1174 	    /* ":let var1 var2" */
1175 	    arg = list_arg_vars(eap, arg, &first);
1176 	else if (!eap->skip)
1177 	{
1178 	    /* ":let" */
1179 	    list_glob_vars(&first);
1180 	    list_buf_vars(&first);
1181 	    list_win_vars(&first);
1182 #ifdef FEAT_WINDOWS
1183 	    list_tab_vars(&first);
1184 #endif
1185 	    list_script_vars(&first);
1186 	    list_func_vars(&first);
1187 	    list_vim_vars(&first);
1188 	}
1189 	eap->nextcmd = check_nextcmd(arg);
1190     }
1191     else
1192     {
1193 	op[0] = '=';
1194 	op[1] = NUL;
1195 	if (*expr != '=')
1196 	{
1197 	    if (vim_strchr((char_u *)"+-.", *expr) != NULL)
1198 		op[0] = *expr;   /* +=, -= or .= */
1199 	    expr = skipwhite(expr + 2);
1200 	}
1201 	else
1202 	    expr = skipwhite(expr + 1);
1203 
1204 	if (eap->skip)
1205 	    ++emsg_skip;
1206 	i = eval0(expr, &rettv, &eap->nextcmd, !eap->skip);
1207 	if (eap->skip)
1208 	{
1209 	    if (i != FAIL)
1210 		clear_tv(&rettv);
1211 	    --emsg_skip;
1212 	}
1213 	else if (i != FAIL)
1214 	{
1215 	    (void)ex_let_vars(eap->arg, &rettv, FALSE, semicolon, var_count,
1216 									  op);
1217 	    clear_tv(&rettv);
1218 	}
1219     }
1220 }
1221 
1222 /*
1223  * Assign the typevalue "tv" to the variable or variables at "arg_start".
1224  * Handles both "var" with any type and "[var, var; var]" with a list type.
1225  * When "nextchars" is not NULL it points to a string with characters that
1226  * must appear after the variable(s).  Use "+", "-" or "." for add, subtract
1227  * or concatenate.
1228  * Returns OK or FAIL;
1229  */
1230     static int
1231 ex_let_vars(
1232     char_u	*arg_start,
1233     typval_T	*tv,
1234     int		copy,		/* copy values from "tv", don't move */
1235     int		semicolon,	/* from skip_var_list() */
1236     int		var_count,	/* from skip_var_list() */
1237     char_u	*nextchars)
1238 {
1239     char_u	*arg = arg_start;
1240     list_T	*l;
1241     int		i;
1242     listitem_T	*item;
1243     typval_T	ltv;
1244 
1245     if (*arg != '[')
1246     {
1247 	/*
1248 	 * ":let var = expr" or ":for var in list"
1249 	 */
1250 	if (ex_let_one(arg, tv, copy, nextchars, nextchars) == NULL)
1251 	    return FAIL;
1252 	return OK;
1253     }
1254 
1255     /*
1256      * ":let [v1, v2] = list" or ":for [v1, v2] in listlist"
1257      */
1258     if (tv->v_type != VAR_LIST || (l = tv->vval.v_list) == NULL)
1259     {
1260 	EMSG(_(e_listreq));
1261 	return FAIL;
1262     }
1263 
1264     i = list_len(l);
1265     if (semicolon == 0 && var_count < i)
1266     {
1267 	EMSG(_("E687: Less targets than List items"));
1268 	return FAIL;
1269     }
1270     if (var_count - semicolon > i)
1271     {
1272 	EMSG(_("E688: More targets than List items"));
1273 	return FAIL;
1274     }
1275 
1276     item = l->lv_first;
1277     while (*arg != ']')
1278     {
1279 	arg = skipwhite(arg + 1);
1280 	arg = ex_let_one(arg, &item->li_tv, TRUE, (char_u *)",;]", nextchars);
1281 	item = item->li_next;
1282 	if (arg == NULL)
1283 	    return FAIL;
1284 
1285 	arg = skipwhite(arg);
1286 	if (*arg == ';')
1287 	{
1288 	    /* Put the rest of the list (may be empty) in the var after ';'.
1289 	     * Create a new list for this. */
1290 	    l = list_alloc();
1291 	    if (l == NULL)
1292 		return FAIL;
1293 	    while (item != NULL)
1294 	    {
1295 		list_append_tv(l, &item->li_tv);
1296 		item = item->li_next;
1297 	    }
1298 
1299 	    ltv.v_type = VAR_LIST;
1300 	    ltv.v_lock = 0;
1301 	    ltv.vval.v_list = l;
1302 	    l->lv_refcount = 1;
1303 
1304 	    arg = ex_let_one(skipwhite(arg + 1), &ltv, FALSE,
1305 						    (char_u *)"]", nextchars);
1306 	    clear_tv(&ltv);
1307 	    if (arg == NULL)
1308 		return FAIL;
1309 	    break;
1310 	}
1311 	else if (*arg != ',' && *arg != ']')
1312 	{
1313 	    EMSG2(_(e_intern2), "ex_let_vars()");
1314 	    return FAIL;
1315 	}
1316     }
1317 
1318     return OK;
1319 }
1320 
1321 /*
1322  * Skip over assignable variable "var" or list of variables "[var, var]".
1323  * Used for ":let varvar = expr" and ":for varvar in expr".
1324  * For "[var, var]" increment "*var_count" for each variable.
1325  * for "[var, var; var]" set "semicolon".
1326  * Return NULL for an error.
1327  */
1328     static char_u *
1329 skip_var_list(
1330     char_u	*arg,
1331     int		*var_count,
1332     int		*semicolon)
1333 {
1334     char_u	*p, *s;
1335 
1336     if (*arg == '[')
1337     {
1338 	/* "[var, var]": find the matching ']'. */
1339 	p = arg;
1340 	for (;;)
1341 	{
1342 	    p = skipwhite(p + 1);	/* skip whites after '[', ';' or ',' */
1343 	    s = skip_var_one(p);
1344 	    if (s == p)
1345 	    {
1346 		EMSG2(_(e_invarg2), p);
1347 		return NULL;
1348 	    }
1349 	    ++*var_count;
1350 
1351 	    p = skipwhite(s);
1352 	    if (*p == ']')
1353 		break;
1354 	    else if (*p == ';')
1355 	    {
1356 		if (*semicolon == 1)
1357 		{
1358 		    EMSG(_("Double ; in list of variables"));
1359 		    return NULL;
1360 		}
1361 		*semicolon = 1;
1362 	    }
1363 	    else if (*p != ',')
1364 	    {
1365 		EMSG2(_(e_invarg2), p);
1366 		return NULL;
1367 	    }
1368 	}
1369 	return p + 1;
1370     }
1371     else
1372 	return skip_var_one(arg);
1373 }
1374 
1375 /*
1376  * Skip one (assignable) variable name, including @r, $VAR, &option, d.key,
1377  * l[idx].
1378  */
1379     static char_u *
1380 skip_var_one(char_u *arg)
1381 {
1382     if (*arg == '@' && arg[1] != NUL)
1383 	return arg + 2;
1384     return find_name_end(*arg == '$' || *arg == '&' ? arg + 1 : arg,
1385 				   NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1386 }
1387 
1388 /*
1389  * List variables for hashtab "ht" with prefix "prefix".
1390  * If "empty" is TRUE also list NULL strings as empty strings.
1391  */
1392     void
1393 list_hashtable_vars(
1394     hashtab_T	*ht,
1395     char_u	*prefix,
1396     int		empty,
1397     int		*first)
1398 {
1399     hashitem_T	*hi;
1400     dictitem_T	*di;
1401     int		todo;
1402 
1403     todo = (int)ht->ht_used;
1404     for (hi = ht->ht_array; todo > 0 && !got_int; ++hi)
1405     {
1406 	if (!HASHITEM_EMPTY(hi))
1407 	{
1408 	    --todo;
1409 	    di = HI2DI(hi);
1410 	    if (empty || di->di_tv.v_type != VAR_STRING
1411 					   || di->di_tv.vval.v_string != NULL)
1412 		list_one_var(di, prefix, first);
1413 	}
1414     }
1415 }
1416 
1417 /*
1418  * List global variables.
1419  */
1420     static void
1421 list_glob_vars(int *first)
1422 {
1423     list_hashtable_vars(&globvarht, (char_u *)"", TRUE, first);
1424 }
1425 
1426 /*
1427  * List buffer variables.
1428  */
1429     static void
1430 list_buf_vars(int *first)
1431 {
1432     char_u	numbuf[NUMBUFLEN];
1433 
1434     list_hashtable_vars(&curbuf->b_vars->dv_hashtab, (char_u *)"b:",
1435 								 TRUE, first);
1436 
1437     sprintf((char *)numbuf, "%ld", (long)curbuf->b_changedtick);
1438     list_one_var_a((char_u *)"b:", (char_u *)"changedtick", VAR_NUMBER,
1439 							       numbuf, first);
1440 }
1441 
1442 /*
1443  * List window variables.
1444  */
1445     static void
1446 list_win_vars(int *first)
1447 {
1448     list_hashtable_vars(&curwin->w_vars->dv_hashtab,
1449 						 (char_u *)"w:", TRUE, first);
1450 }
1451 
1452 #ifdef FEAT_WINDOWS
1453 /*
1454  * List tab page variables.
1455  */
1456     static void
1457 list_tab_vars(int *first)
1458 {
1459     list_hashtable_vars(&curtab->tp_vars->dv_hashtab,
1460 						 (char_u *)"t:", TRUE, first);
1461 }
1462 #endif
1463 
1464 /*
1465  * List Vim variables.
1466  */
1467     static void
1468 list_vim_vars(int *first)
1469 {
1470     list_hashtable_vars(&vimvarht, (char_u *)"v:", FALSE, first);
1471 }
1472 
1473 /*
1474  * List script-local variables, if there is a script.
1475  */
1476     static void
1477 list_script_vars(int *first)
1478 {
1479     if (current_SID > 0 && current_SID <= ga_scripts.ga_len)
1480 	list_hashtable_vars(&SCRIPT_VARS(current_SID),
1481 						(char_u *)"s:", FALSE, first);
1482 }
1483 
1484 /*
1485  * List variables in "arg".
1486  */
1487     static char_u *
1488 list_arg_vars(exarg_T *eap, char_u *arg, int *first)
1489 {
1490     int		error = FALSE;
1491     int		len;
1492     char_u	*name;
1493     char_u	*name_start;
1494     char_u	*arg_subsc;
1495     char_u	*tofree;
1496     typval_T    tv;
1497 
1498     while (!ends_excmd(*arg) && !got_int)
1499     {
1500 	if (error || eap->skip)
1501 	{
1502 	    arg = find_name_end(arg, NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1503 	    if (!vim_iswhite(*arg) && !ends_excmd(*arg))
1504 	    {
1505 		emsg_severe = TRUE;
1506 		EMSG(_(e_trailing));
1507 		break;
1508 	    }
1509 	}
1510 	else
1511 	{
1512 	    /* get_name_len() takes care of expanding curly braces */
1513 	    name_start = name = arg;
1514 	    len = get_name_len(&arg, &tofree, TRUE, TRUE);
1515 	    if (len <= 0)
1516 	    {
1517 		/* This is mainly to keep test 49 working: when expanding
1518 		 * curly braces fails overrule the exception error message. */
1519 		if (len < 0 && !aborting())
1520 		{
1521 		    emsg_severe = TRUE;
1522 		    EMSG2(_(e_invarg2), arg);
1523 		    break;
1524 		}
1525 		error = TRUE;
1526 	    }
1527 	    else
1528 	    {
1529 		if (tofree != NULL)
1530 		    name = tofree;
1531 		if (get_var_tv(name, len, &tv, NULL, TRUE, FALSE) == FAIL)
1532 		    error = TRUE;
1533 		else
1534 		{
1535 		    /* handle d.key, l[idx], f(expr) */
1536 		    arg_subsc = arg;
1537 		    if (handle_subscript(&arg, &tv, TRUE, TRUE) == FAIL)
1538 			error = TRUE;
1539 		    else
1540 		    {
1541 			if (arg == arg_subsc && len == 2 && name[1] == ':')
1542 			{
1543 			    switch (*name)
1544 			    {
1545 				case 'g': list_glob_vars(first); break;
1546 				case 'b': list_buf_vars(first); break;
1547 				case 'w': list_win_vars(first); break;
1548 #ifdef FEAT_WINDOWS
1549 				case 't': list_tab_vars(first); break;
1550 #endif
1551 				case 'v': list_vim_vars(first); break;
1552 				case 's': list_script_vars(first); break;
1553 				case 'l': list_func_vars(first); break;
1554 				default:
1555 					  EMSG2(_("E738: Can't list variables for %s"), name);
1556 			    }
1557 			}
1558 			else
1559 			{
1560 			    char_u	numbuf[NUMBUFLEN];
1561 			    char_u	*tf;
1562 			    int		c;
1563 			    char_u	*s;
1564 
1565 			    s = echo_string(&tv, &tf, numbuf, 0);
1566 			    c = *arg;
1567 			    *arg = NUL;
1568 			    list_one_var_a((char_u *)"",
1569 				    arg == arg_subsc ? name : name_start,
1570 				    tv.v_type,
1571 				    s == NULL ? (char_u *)"" : s,
1572 				    first);
1573 			    *arg = c;
1574 			    vim_free(tf);
1575 			}
1576 			clear_tv(&tv);
1577 		    }
1578 		}
1579 	    }
1580 
1581 	    vim_free(tofree);
1582 	}
1583 
1584 	arg = skipwhite(arg);
1585     }
1586 
1587     return arg;
1588 }
1589 
1590 /*
1591  * Set one item of ":let var = expr" or ":let [v1, v2] = list" to its value.
1592  * Returns a pointer to the char just after the var name.
1593  * Returns NULL if there is an error.
1594  */
1595     static char_u *
1596 ex_let_one(
1597     char_u	*arg,		/* points to variable name */
1598     typval_T	*tv,		/* value to assign to variable */
1599     int		copy,		/* copy value from "tv" */
1600     char_u	*endchars,	/* valid chars after variable name  or NULL */
1601     char_u	*op)		/* "+", "-", "."  or NULL*/
1602 {
1603     int		c1;
1604     char_u	*name;
1605     char_u	*p;
1606     char_u	*arg_end = NULL;
1607     int		len;
1608     int		opt_flags;
1609     char_u	*tofree = NULL;
1610 
1611     /*
1612      * ":let $VAR = expr": Set environment variable.
1613      */
1614     if (*arg == '$')
1615     {
1616 	/* Find the end of the name. */
1617 	++arg;
1618 	name = arg;
1619 	len = get_env_len(&arg);
1620 	if (len == 0)
1621 	    EMSG2(_(e_invarg2), name - 1);
1622 	else
1623 	{
1624 	    if (op != NULL && (*op == '+' || *op == '-'))
1625 		EMSG2(_(e_letwrong), op);
1626 	    else if (endchars != NULL
1627 			     && vim_strchr(endchars, *skipwhite(arg)) == NULL)
1628 		EMSG(_(e_letunexp));
1629 	    else if (!check_secure())
1630 	    {
1631 		c1 = name[len];
1632 		name[len] = NUL;
1633 		p = get_tv_string_chk(tv);
1634 		if (p != NULL && op != NULL && *op == '.')
1635 		{
1636 		    int	    mustfree = FALSE;
1637 		    char_u  *s = vim_getenv(name, &mustfree);
1638 
1639 		    if (s != NULL)
1640 		    {
1641 			p = tofree = concat_str(s, p);
1642 			if (mustfree)
1643 			    vim_free(s);
1644 		    }
1645 		}
1646 		if (p != NULL)
1647 		{
1648 		    vim_setenv(name, p);
1649 		    if (STRICMP(name, "HOME") == 0)
1650 			init_homedir();
1651 		    else if (didset_vim && STRICMP(name, "VIM") == 0)
1652 			didset_vim = FALSE;
1653 		    else if (didset_vimruntime
1654 					&& STRICMP(name, "VIMRUNTIME") == 0)
1655 			didset_vimruntime = FALSE;
1656 		    arg_end = arg;
1657 		}
1658 		name[len] = c1;
1659 		vim_free(tofree);
1660 	    }
1661 	}
1662     }
1663 
1664     /*
1665      * ":let &option = expr": Set option value.
1666      * ":let &l:option = expr": Set local option value.
1667      * ":let &g:option = expr": Set global option value.
1668      */
1669     else if (*arg == '&')
1670     {
1671 	/* Find the end of the name. */
1672 	p = find_option_end(&arg, &opt_flags);
1673 	if (p == NULL || (endchars != NULL
1674 			      && vim_strchr(endchars, *skipwhite(p)) == NULL))
1675 	    EMSG(_(e_letunexp));
1676 	else
1677 	{
1678 	    long	n;
1679 	    int		opt_type;
1680 	    long	numval;
1681 	    char_u	*stringval = NULL;
1682 	    char_u	*s;
1683 
1684 	    c1 = *p;
1685 	    *p = NUL;
1686 
1687 	    n = (long)get_tv_number(tv);
1688 	    s = get_tv_string_chk(tv);	    /* != NULL if number or string */
1689 	    if (s != NULL && op != NULL && *op != '=')
1690 	    {
1691 		opt_type = get_option_value(arg, &numval,
1692 						       &stringval, opt_flags);
1693 		if ((opt_type == 1 && *op == '.')
1694 			|| (opt_type == 0 && *op != '.'))
1695 		    EMSG2(_(e_letwrong), op);
1696 		else
1697 		{
1698 		    if (opt_type == 1)  /* number */
1699 		    {
1700 			if (*op == '+')
1701 			    n = numval + n;
1702 			else
1703 			    n = numval - n;
1704 		    }
1705 		    else if (opt_type == 0 && stringval != NULL) /* string */
1706 		    {
1707 			s = concat_str(stringval, s);
1708 			vim_free(stringval);
1709 			stringval = s;
1710 		    }
1711 		}
1712 	    }
1713 	    if (s != NULL)
1714 	    {
1715 		set_option_value(arg, n, s, opt_flags);
1716 		arg_end = p;
1717 	    }
1718 	    *p = c1;
1719 	    vim_free(stringval);
1720 	}
1721     }
1722 
1723     /*
1724      * ":let @r = expr": Set register contents.
1725      */
1726     else if (*arg == '@')
1727     {
1728 	++arg;
1729 	if (op != NULL && (*op == '+' || *op == '-'))
1730 	    EMSG2(_(e_letwrong), op);
1731 	else if (endchars != NULL
1732 			 && vim_strchr(endchars, *skipwhite(arg + 1)) == NULL)
1733 	    EMSG(_(e_letunexp));
1734 	else
1735 	{
1736 	    char_u	*ptofree = NULL;
1737 	    char_u	*s;
1738 
1739 	    p = get_tv_string_chk(tv);
1740 	    if (p != NULL && op != NULL && *op == '.')
1741 	    {
1742 		s = get_reg_contents(*arg == '@' ? '"' : *arg, GREG_EXPR_SRC);
1743 		if (s != NULL)
1744 		{
1745 		    p = ptofree = concat_str(s, p);
1746 		    vim_free(s);
1747 		}
1748 	    }
1749 	    if (p != NULL)
1750 	    {
1751 		write_reg_contents(*arg == '@' ? '"' : *arg, p, -1, FALSE);
1752 		arg_end = arg + 1;
1753 	    }
1754 	    vim_free(ptofree);
1755 	}
1756     }
1757 
1758     /*
1759      * ":let var = expr": Set internal variable.
1760      * ":let {expr} = expr": Idem, name made with curly braces
1761      */
1762     else if (eval_isnamec1(*arg) || *arg == '{')
1763     {
1764 	lval_T	lv;
1765 
1766 	p = get_lval(arg, tv, &lv, FALSE, FALSE, 0, FNE_CHECK_START);
1767 	if (p != NULL && lv.ll_name != NULL)
1768 	{
1769 	    if (endchars != NULL && vim_strchr(endchars, *skipwhite(p)) == NULL)
1770 		EMSG(_(e_letunexp));
1771 	    else
1772 	    {
1773 		set_var_lval(&lv, p, tv, copy, op);
1774 		arg_end = p;
1775 	    }
1776 	}
1777 	clear_lval(&lv);
1778     }
1779 
1780     else
1781 	EMSG2(_(e_invarg2), arg);
1782 
1783     return arg_end;
1784 }
1785 
1786 /*
1787  * If "arg" is equal to "b:changedtick" give an error and return TRUE.
1788  */
1789     int
1790 check_changedtick(char_u *arg)
1791 {
1792     if (STRNCMP(arg, "b:changedtick", 13) == 0 && !eval_isnamec(arg[13]))
1793     {
1794 	EMSG2(_(e_readonlyvar), arg);
1795 	return TRUE;
1796     }
1797     return FALSE;
1798 }
1799 
1800 /*
1801  * Get an lval: variable, Dict item or List item that can be assigned a value
1802  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
1803  * "name.key", "name.key[expr]" etc.
1804  * Indexing only works if "name" is an existing List or Dictionary.
1805  * "name" points to the start of the name.
1806  * If "rettv" is not NULL it points to the value to be assigned.
1807  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
1808  * wrong; must end in space or cmd separator.
1809  *
1810  * flags:
1811  *  GLV_QUIET:       do not give error messages
1812  *  GLV_NO_AUTOLOAD: do not use script autoloading
1813  *
1814  * Returns a pointer to just after the name, including indexes.
1815  * When an evaluation error occurs "lp->ll_name" is NULL;
1816  * Returns NULL for a parsing error.  Still need to free items in "lp"!
1817  */
1818     char_u *
1819 get_lval(
1820     char_u	*name,
1821     typval_T	*rettv,
1822     lval_T	*lp,
1823     int		unlet,
1824     int		skip,
1825     int		flags,	    /* GLV_ values */
1826     int		fne_flags)  /* flags for find_name_end() */
1827 {
1828     char_u	*p;
1829     char_u	*expr_start, *expr_end;
1830     int		cc;
1831     dictitem_T	*v;
1832     typval_T	var1;
1833     typval_T	var2;
1834     int		empty1 = FALSE;
1835     listitem_T	*ni;
1836     char_u	*key = NULL;
1837     int		len;
1838     hashtab_T	*ht;
1839     int		quiet = flags & GLV_QUIET;
1840 
1841     /* Clear everything in "lp". */
1842     vim_memset(lp, 0, sizeof(lval_T));
1843 
1844     if (skip)
1845     {
1846 	/* When skipping just find the end of the name. */
1847 	lp->ll_name = name;
1848 	return find_name_end(name, NULL, NULL, FNE_INCL_BR | fne_flags);
1849     }
1850 
1851     /* Find the end of the name. */
1852     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
1853     if (expr_start != NULL)
1854     {
1855 	/* Don't expand the name when we already know there is an error. */
1856 	if (unlet && !vim_iswhite(*p) && !ends_excmd(*p)
1857 						    && *p != '[' && *p != '.')
1858 	{
1859 	    EMSG(_(e_trailing));
1860 	    return NULL;
1861 	}
1862 
1863 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
1864 	if (lp->ll_exp_name == NULL)
1865 	{
1866 	    /* Report an invalid expression in braces, unless the
1867 	     * expression evaluation has been cancelled due to an
1868 	     * aborting error, an interrupt, or an exception. */
1869 	    if (!aborting() && !quiet)
1870 	    {
1871 		emsg_severe = TRUE;
1872 		EMSG2(_(e_invarg2), name);
1873 		return NULL;
1874 	    }
1875 	}
1876 	lp->ll_name = lp->ll_exp_name;
1877     }
1878     else
1879 	lp->ll_name = name;
1880 
1881     /* Without [idx] or .key we are done. */
1882     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
1883 	return p;
1884 
1885     cc = *p;
1886     *p = NUL;
1887     v = find_var(lp->ll_name, &ht, flags & GLV_NO_AUTOLOAD);
1888     if (v == NULL && !quiet)
1889 	EMSG2(_(e_undefvar), lp->ll_name);
1890     *p = cc;
1891     if (v == NULL)
1892 	return NULL;
1893 
1894     /*
1895      * Loop until no more [idx] or .key is following.
1896      */
1897     lp->ll_tv = &v->di_tv;
1898     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
1899     {
1900 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
1901 		&& !(lp->ll_tv->v_type == VAR_DICT
1902 					   && lp->ll_tv->vval.v_dict != NULL))
1903 	{
1904 	    if (!quiet)
1905 		EMSG(_("E689: Can only index a List or Dictionary"));
1906 	    return NULL;
1907 	}
1908 	if (lp->ll_range)
1909 	{
1910 	    if (!quiet)
1911 		EMSG(_("E708: [:] must come last"));
1912 	    return NULL;
1913 	}
1914 
1915 	len = -1;
1916 	if (*p == '.')
1917 	{
1918 	    key = p + 1;
1919 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
1920 		;
1921 	    if (len == 0)
1922 	    {
1923 		if (!quiet)
1924 		    EMSG(_(e_emptykey));
1925 		return NULL;
1926 	    }
1927 	    p = key + len;
1928 	}
1929 	else
1930 	{
1931 	    /* Get the index [expr] or the first index [expr: ]. */
1932 	    p = skipwhite(p + 1);
1933 	    if (*p == ':')
1934 		empty1 = TRUE;
1935 	    else
1936 	    {
1937 		empty1 = FALSE;
1938 		if (eval1(&p, &var1, TRUE) == FAIL)	/* recursive! */
1939 		    return NULL;
1940 		if (get_tv_string_chk(&var1) == NULL)
1941 		{
1942 		    /* not a number or string */
1943 		    clear_tv(&var1);
1944 		    return NULL;
1945 		}
1946 	    }
1947 
1948 	    /* Optionally get the second index [ :expr]. */
1949 	    if (*p == ':')
1950 	    {
1951 		if (lp->ll_tv->v_type == VAR_DICT)
1952 		{
1953 		    if (!quiet)
1954 			EMSG(_(e_dictrange));
1955 		    if (!empty1)
1956 			clear_tv(&var1);
1957 		    return NULL;
1958 		}
1959 		if (rettv != NULL && (rettv->v_type != VAR_LIST
1960 					       || rettv->vval.v_list == NULL))
1961 		{
1962 		    if (!quiet)
1963 			EMSG(_("E709: [:] requires a List value"));
1964 		    if (!empty1)
1965 			clear_tv(&var1);
1966 		    return NULL;
1967 		}
1968 		p = skipwhite(p + 1);
1969 		if (*p == ']')
1970 		    lp->ll_empty2 = TRUE;
1971 		else
1972 		{
1973 		    lp->ll_empty2 = FALSE;
1974 		    if (eval1(&p, &var2, TRUE) == FAIL)	/* recursive! */
1975 		    {
1976 			if (!empty1)
1977 			    clear_tv(&var1);
1978 			return NULL;
1979 		    }
1980 		    if (get_tv_string_chk(&var2) == NULL)
1981 		    {
1982 			/* not a number or string */
1983 			if (!empty1)
1984 			    clear_tv(&var1);
1985 			clear_tv(&var2);
1986 			return NULL;
1987 		    }
1988 		}
1989 		lp->ll_range = TRUE;
1990 	    }
1991 	    else
1992 		lp->ll_range = FALSE;
1993 
1994 	    if (*p != ']')
1995 	    {
1996 		if (!quiet)
1997 		    EMSG(_(e_missbrac));
1998 		if (!empty1)
1999 		    clear_tv(&var1);
2000 		if (lp->ll_range && !lp->ll_empty2)
2001 		    clear_tv(&var2);
2002 		return NULL;
2003 	    }
2004 
2005 	    /* Skip to past ']'. */
2006 	    ++p;
2007 	}
2008 
2009 	if (lp->ll_tv->v_type == VAR_DICT)
2010 	{
2011 	    if (len == -1)
2012 	    {
2013 		/* "[key]": get key from "var1" */
2014 		key = get_tv_string_chk(&var1);	/* is number or string */
2015 		if (key == NULL)
2016 		{
2017 		    clear_tv(&var1);
2018 		    return NULL;
2019 		}
2020 	    }
2021 	    lp->ll_list = NULL;
2022 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
2023 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
2024 
2025 	    /* When assigning to a scope dictionary check that a function and
2026 	     * variable name is valid (only variable name unless it is l: or
2027 	     * g: dictionary). Disallow overwriting a builtin function. */
2028 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
2029 	    {
2030 		int prevval;
2031 		int wrong;
2032 
2033 		if (len != -1)
2034 		{
2035 		    prevval = key[len];
2036 		    key[len] = NUL;
2037 		}
2038 		else
2039 		    prevval = 0; /* avoid compiler warning */
2040 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
2041 			       && rettv->v_type == VAR_FUNC
2042 			       && var_check_func_name(key, lp->ll_di == NULL))
2043 			|| !valid_varname(key);
2044 		if (len != -1)
2045 		    key[len] = prevval;
2046 		if (wrong)
2047 		    return NULL;
2048 	    }
2049 
2050 	    if (lp->ll_di == NULL)
2051 	    {
2052 		/* Can't add "v:" variable. */
2053 		if (lp->ll_dict == &vimvardict)
2054 		{
2055 		    EMSG2(_(e_illvar), name);
2056 		    return NULL;
2057 		}
2058 
2059 		/* Key does not exist in dict: may need to add it. */
2060 		if (*p == '[' || *p == '.' || unlet)
2061 		{
2062 		    if (!quiet)
2063 			EMSG2(_(e_dictkey), key);
2064 		    if (len == -1)
2065 			clear_tv(&var1);
2066 		    return NULL;
2067 		}
2068 		if (len == -1)
2069 		    lp->ll_newkey = vim_strsave(key);
2070 		else
2071 		    lp->ll_newkey = vim_strnsave(key, len);
2072 		if (len == -1)
2073 		    clear_tv(&var1);
2074 		if (lp->ll_newkey == NULL)
2075 		    p = NULL;
2076 		break;
2077 	    }
2078 	    /* existing variable, need to check if it can be changed */
2079 	    else if (var_check_ro(lp->ll_di->di_flags, name, FALSE))
2080 		return NULL;
2081 
2082 	    if (len == -1)
2083 		clear_tv(&var1);
2084 	    lp->ll_tv = &lp->ll_di->di_tv;
2085 	}
2086 	else
2087 	{
2088 	    /*
2089 	     * Get the number and item for the only or first index of the List.
2090 	     */
2091 	    if (empty1)
2092 		lp->ll_n1 = 0;
2093 	    else
2094 	    {
2095 		lp->ll_n1 = (long)get_tv_number(&var1);
2096 						    /* is number or string */
2097 		clear_tv(&var1);
2098 	    }
2099 	    lp->ll_dict = NULL;
2100 	    lp->ll_list = lp->ll_tv->vval.v_list;
2101 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2102 	    if (lp->ll_li == NULL)
2103 	    {
2104 		if (lp->ll_n1 < 0)
2105 		{
2106 		    lp->ll_n1 = 0;
2107 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2108 		}
2109 	    }
2110 	    if (lp->ll_li == NULL)
2111 	    {
2112 		if (lp->ll_range && !lp->ll_empty2)
2113 		    clear_tv(&var2);
2114 		if (!quiet)
2115 		    EMSGN(_(e_listidx), lp->ll_n1);
2116 		return NULL;
2117 	    }
2118 
2119 	    /*
2120 	     * May need to find the item or absolute index for the second
2121 	     * index of a range.
2122 	     * When no index given: "lp->ll_empty2" is TRUE.
2123 	     * Otherwise "lp->ll_n2" is set to the second index.
2124 	     */
2125 	    if (lp->ll_range && !lp->ll_empty2)
2126 	    {
2127 		lp->ll_n2 = (long)get_tv_number(&var2);
2128 						    /* is number or string */
2129 		clear_tv(&var2);
2130 		if (lp->ll_n2 < 0)
2131 		{
2132 		    ni = list_find(lp->ll_list, lp->ll_n2);
2133 		    if (ni == NULL)
2134 		    {
2135 			if (!quiet)
2136 			    EMSGN(_(e_listidx), lp->ll_n2);
2137 			return NULL;
2138 		    }
2139 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
2140 		}
2141 
2142 		/* Check that lp->ll_n2 isn't before lp->ll_n1. */
2143 		if (lp->ll_n1 < 0)
2144 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
2145 		if (lp->ll_n2 < lp->ll_n1)
2146 		{
2147 		    if (!quiet)
2148 			EMSGN(_(e_listidx), lp->ll_n2);
2149 		    return NULL;
2150 		}
2151 	    }
2152 
2153 	    lp->ll_tv = &lp->ll_li->li_tv;
2154 	}
2155     }
2156 
2157     return p;
2158 }
2159 
2160 /*
2161  * Clear lval "lp" that was filled by get_lval().
2162  */
2163     void
2164 clear_lval(lval_T *lp)
2165 {
2166     vim_free(lp->ll_exp_name);
2167     vim_free(lp->ll_newkey);
2168 }
2169 
2170 /*
2171  * Set a variable that was parsed by get_lval() to "rettv".
2172  * "endp" points to just after the parsed name.
2173  * "op" is NULL, "+" for "+=", "-" for "-=", "." for ".=" or "=" for "=".
2174  */
2175     static void
2176 set_var_lval(
2177     lval_T	*lp,
2178     char_u	*endp,
2179     typval_T	*rettv,
2180     int		copy,
2181     char_u	*op)
2182 {
2183     int		cc;
2184     listitem_T	*ri;
2185     dictitem_T	*di;
2186 
2187     if (lp->ll_tv == NULL)
2188     {
2189 	if (!check_changedtick(lp->ll_name))
2190 	{
2191 	    cc = *endp;
2192 	    *endp = NUL;
2193 	    if (op != NULL && *op != '=')
2194 	    {
2195 		typval_T tv;
2196 
2197 		/* handle +=, -= and .= */
2198 		di = NULL;
2199 		if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
2200 						 &tv, &di, TRUE, FALSE) == OK)
2201 		{
2202 		    if ((di == NULL
2203 			   || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
2204 			      && !tv_check_lock(di->di_tv.v_lock, lp->ll_name,
2205 								      FALSE)))
2206 			    && tv_op(&tv, rettv, op) == OK)
2207 			set_var(lp->ll_name, &tv, FALSE);
2208 		    clear_tv(&tv);
2209 		}
2210 	    }
2211 	    else
2212 		set_var(lp->ll_name, rettv, copy);
2213 	    *endp = cc;
2214 	}
2215     }
2216     else if (tv_check_lock(lp->ll_newkey == NULL
2217 		? lp->ll_tv->v_lock
2218 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
2219 	;
2220     else if (lp->ll_range)
2221     {
2222 	listitem_T *ll_li = lp->ll_li;
2223 	int ll_n1 = lp->ll_n1;
2224 
2225 	/*
2226 	 * Check whether any of the list items is locked
2227 	 */
2228 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
2229 	{
2230 	    if (tv_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
2231 		return;
2232 	    ri = ri->li_next;
2233 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
2234 		break;
2235 	    ll_li = ll_li->li_next;
2236 	    ++ll_n1;
2237 	}
2238 
2239 	/*
2240 	 * Assign the List values to the list items.
2241 	 */
2242 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
2243 	{
2244 	    if (op != NULL && *op != '=')
2245 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
2246 	    else
2247 	    {
2248 		clear_tv(&lp->ll_li->li_tv);
2249 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
2250 	    }
2251 	    ri = ri->li_next;
2252 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
2253 		break;
2254 	    if (lp->ll_li->li_next == NULL)
2255 	    {
2256 		/* Need to add an empty item. */
2257 		if (list_append_number(lp->ll_list, 0) == FAIL)
2258 		{
2259 		    ri = NULL;
2260 		    break;
2261 		}
2262 	    }
2263 	    lp->ll_li = lp->ll_li->li_next;
2264 	    ++lp->ll_n1;
2265 	}
2266 	if (ri != NULL)
2267 	    EMSG(_("E710: List value has more items than target"));
2268 	else if (lp->ll_empty2
2269 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
2270 		: lp->ll_n1 != lp->ll_n2)
2271 	    EMSG(_("E711: List value has not enough items"));
2272     }
2273     else
2274     {
2275 	/*
2276 	 * Assign to a List or Dictionary item.
2277 	 */
2278 	if (lp->ll_newkey != NULL)
2279 	{
2280 	    if (op != NULL && *op != '=')
2281 	    {
2282 		EMSG2(_(e_letwrong), op);
2283 		return;
2284 	    }
2285 
2286 	    /* Need to add an item to the Dictionary. */
2287 	    di = dictitem_alloc(lp->ll_newkey);
2288 	    if (di == NULL)
2289 		return;
2290 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
2291 	    {
2292 		vim_free(di);
2293 		return;
2294 	    }
2295 	    lp->ll_tv = &di->di_tv;
2296 	}
2297 	else if (op != NULL && *op != '=')
2298 	{
2299 	    tv_op(lp->ll_tv, rettv, op);
2300 	    return;
2301 	}
2302 	else
2303 	    clear_tv(lp->ll_tv);
2304 
2305 	/*
2306 	 * Assign the value to the variable or list item.
2307 	 */
2308 	if (copy)
2309 	    copy_tv(rettv, lp->ll_tv);
2310 	else
2311 	{
2312 	    *lp->ll_tv = *rettv;
2313 	    lp->ll_tv->v_lock = 0;
2314 	    init_tv(rettv);
2315 	}
2316     }
2317 }
2318 
2319 /*
2320  * Handle "tv1 += tv2", "tv1 -= tv2" and "tv1 .= tv2"
2321  * Returns OK or FAIL.
2322  */
2323     static int
2324 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
2325 {
2326     varnumber_T	n;
2327     char_u	numbuf[NUMBUFLEN];
2328     char_u	*s;
2329 
2330     /* Can't do anything with a Funcref, Dict, v:true on the right. */
2331     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
2332 						&& tv2->v_type != VAR_SPECIAL)
2333     {
2334 	switch (tv1->v_type)
2335 	{
2336 	    case VAR_UNKNOWN:
2337 	    case VAR_DICT:
2338 	    case VAR_FUNC:
2339 	    case VAR_PARTIAL:
2340 	    case VAR_SPECIAL:
2341 	    case VAR_JOB:
2342 	    case VAR_CHANNEL:
2343 		break;
2344 
2345 	    case VAR_LIST:
2346 		if (*op != '+' || tv2->v_type != VAR_LIST)
2347 		    break;
2348 		/* List += List */
2349 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
2350 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
2351 		return OK;
2352 
2353 	    case VAR_NUMBER:
2354 	    case VAR_STRING:
2355 		if (tv2->v_type == VAR_LIST)
2356 		    break;
2357 		if (*op == '+' || *op == '-')
2358 		{
2359 		    /* nr += nr  or  nr -= nr*/
2360 		    n = get_tv_number(tv1);
2361 #ifdef FEAT_FLOAT
2362 		    if (tv2->v_type == VAR_FLOAT)
2363 		    {
2364 			float_T f = n;
2365 
2366 			if (*op == '+')
2367 			    f += tv2->vval.v_float;
2368 			else
2369 			    f -= tv2->vval.v_float;
2370 			clear_tv(tv1);
2371 			tv1->v_type = VAR_FLOAT;
2372 			tv1->vval.v_float = f;
2373 		    }
2374 		    else
2375 #endif
2376 		    {
2377 			if (*op == '+')
2378 			    n += get_tv_number(tv2);
2379 			else
2380 			    n -= get_tv_number(tv2);
2381 			clear_tv(tv1);
2382 			tv1->v_type = VAR_NUMBER;
2383 			tv1->vval.v_number = n;
2384 		    }
2385 		}
2386 		else
2387 		{
2388 		    if (tv2->v_type == VAR_FLOAT)
2389 			break;
2390 
2391 		    /* str .= str */
2392 		    s = get_tv_string(tv1);
2393 		    s = concat_str(s, get_tv_string_buf(tv2, numbuf));
2394 		    clear_tv(tv1);
2395 		    tv1->v_type = VAR_STRING;
2396 		    tv1->vval.v_string = s;
2397 		}
2398 		return OK;
2399 
2400 	    case VAR_FLOAT:
2401 #ifdef FEAT_FLOAT
2402 		{
2403 		    float_T f;
2404 
2405 		    if (*op == '.' || (tv2->v_type != VAR_FLOAT
2406 				    && tv2->v_type != VAR_NUMBER
2407 				    && tv2->v_type != VAR_STRING))
2408 			break;
2409 		    if (tv2->v_type == VAR_FLOAT)
2410 			f = tv2->vval.v_float;
2411 		    else
2412 			f = get_tv_number(tv2);
2413 		    if (*op == '+')
2414 			tv1->vval.v_float += f;
2415 		    else
2416 			tv1->vval.v_float -= f;
2417 		}
2418 #endif
2419 		return OK;
2420 	}
2421     }
2422 
2423     EMSG2(_(e_letwrong), op);
2424     return FAIL;
2425 }
2426 
2427 /*
2428  * Evaluate the expression used in a ":for var in expr" command.
2429  * "arg" points to "var".
2430  * Set "*errp" to TRUE for an error, FALSE otherwise;
2431  * Return a pointer that holds the info.  Null when there is an error.
2432  */
2433     void *
2434 eval_for_line(
2435     char_u	*arg,
2436     int		*errp,
2437     char_u	**nextcmdp,
2438     int		skip)
2439 {
2440     forinfo_T	*fi;
2441     char_u	*expr;
2442     typval_T	tv;
2443     list_T	*l;
2444 
2445     *errp = TRUE;	/* default: there is an error */
2446 
2447     fi = (forinfo_T *)alloc_clear(sizeof(forinfo_T));
2448     if (fi == NULL)
2449 	return NULL;
2450 
2451     expr = skip_var_list(arg, &fi->fi_varcount, &fi->fi_semicolon);
2452     if (expr == NULL)
2453 	return fi;
2454 
2455     expr = skipwhite(expr);
2456     if (expr[0] != 'i' || expr[1] != 'n' || !vim_iswhite(expr[2]))
2457     {
2458 	EMSG(_("E690: Missing \"in\" after :for"));
2459 	return fi;
2460     }
2461 
2462     if (skip)
2463 	++emsg_skip;
2464     if (eval0(skipwhite(expr + 2), &tv, nextcmdp, !skip) == OK)
2465     {
2466 	*errp = FALSE;
2467 	if (!skip)
2468 	{
2469 	    l = tv.vval.v_list;
2470 	    if (tv.v_type != VAR_LIST)
2471 	    {
2472 		EMSG(_(e_listreq));
2473 		clear_tv(&tv);
2474 	    }
2475 	    else if (l == NULL)
2476 	    {
2477 		/* a null list is like an empty list: do nothing */
2478 		clear_tv(&tv);
2479 	    }
2480 	    else
2481 	    {
2482 		/* No need to increment the refcount, it's already set for the
2483 		 * list being used in "tv". */
2484 		fi->fi_list = l;
2485 		list_add_watch(l, &fi->fi_lw);
2486 		fi->fi_lw.lw_item = l->lv_first;
2487 	    }
2488 	}
2489     }
2490     if (skip)
2491 	--emsg_skip;
2492 
2493     return fi;
2494 }
2495 
2496 /*
2497  * Use the first item in a ":for" list.  Advance to the next.
2498  * Assign the values to the variable (list).  "arg" points to the first one.
2499  * Return TRUE when a valid item was found, FALSE when at end of list or
2500  * something wrong.
2501  */
2502     int
2503 next_for_item(void *fi_void, char_u *arg)
2504 {
2505     forinfo_T	*fi = (forinfo_T *)fi_void;
2506     int		result;
2507     listitem_T	*item;
2508 
2509     item = fi->fi_lw.lw_item;
2510     if (item == NULL)
2511 	result = FALSE;
2512     else
2513     {
2514 	fi->fi_lw.lw_item = item->li_next;
2515 	result = (ex_let_vars(arg, &item->li_tv, TRUE,
2516 			      fi->fi_semicolon, fi->fi_varcount, NULL) == OK);
2517     }
2518     return result;
2519 }
2520 
2521 /*
2522  * Free the structure used to store info used by ":for".
2523  */
2524     void
2525 free_for_info(void *fi_void)
2526 {
2527     forinfo_T    *fi = (forinfo_T *)fi_void;
2528 
2529     if (fi != NULL && fi->fi_list != NULL)
2530     {
2531 	list_rem_watch(fi->fi_list, &fi->fi_lw);
2532 	list_unref(fi->fi_list);
2533     }
2534     vim_free(fi);
2535 }
2536 
2537 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
2538 
2539     void
2540 set_context_for_expression(
2541     expand_T	*xp,
2542     char_u	*arg,
2543     cmdidx_T	cmdidx)
2544 {
2545     int		got_eq = FALSE;
2546     int		c;
2547     char_u	*p;
2548 
2549     if (cmdidx == CMD_let)
2550     {
2551 	xp->xp_context = EXPAND_USER_VARS;
2552 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
2553 	{
2554 	    /* ":let var1 var2 ...": find last space. */
2555 	    for (p = arg + STRLEN(arg); p >= arg; )
2556 	    {
2557 		xp->xp_pattern = p;
2558 		mb_ptr_back(arg, p);
2559 		if (vim_iswhite(*p))
2560 		    break;
2561 	    }
2562 	    return;
2563 	}
2564     }
2565     else
2566 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
2567 							  : EXPAND_EXPRESSION;
2568     while ((xp->xp_pattern = vim_strpbrk(arg,
2569 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
2570     {
2571 	c = *xp->xp_pattern;
2572 	if (c == '&')
2573 	{
2574 	    c = xp->xp_pattern[1];
2575 	    if (c == '&')
2576 	    {
2577 		++xp->xp_pattern;
2578 		xp->xp_context = cmdidx != CMD_let || got_eq
2579 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
2580 	    }
2581 	    else if (c != ' ')
2582 	    {
2583 		xp->xp_context = EXPAND_SETTINGS;
2584 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
2585 		    xp->xp_pattern += 2;
2586 
2587 	    }
2588 	}
2589 	else if (c == '$')
2590 	{
2591 	    /* environment variable */
2592 	    xp->xp_context = EXPAND_ENV_VARS;
2593 	}
2594 	else if (c == '=')
2595 	{
2596 	    got_eq = TRUE;
2597 	    xp->xp_context = EXPAND_EXPRESSION;
2598 	}
2599 	else if (c == '#'
2600 		&& xp->xp_context == EXPAND_EXPRESSION)
2601 	{
2602 	    /* Autoload function/variable contains '#'. */
2603 	    break;
2604 	}
2605 	else if ((c == '<' || c == '#')
2606 		&& xp->xp_context == EXPAND_FUNCTIONS
2607 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
2608 	{
2609 	    /* Function name can start with "<SNR>" and contain '#'. */
2610 	    break;
2611 	}
2612 	else if (cmdidx != CMD_let || got_eq)
2613 	{
2614 	    if (c == '"')	    /* string */
2615 	    {
2616 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
2617 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
2618 			++xp->xp_pattern;
2619 		xp->xp_context = EXPAND_NOTHING;
2620 	    }
2621 	    else if (c == '\'')	    /* literal string */
2622 	    {
2623 		/* Trick: '' is like stopping and starting a literal string. */
2624 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
2625 		    /* skip */ ;
2626 		xp->xp_context = EXPAND_NOTHING;
2627 	    }
2628 	    else if (c == '|')
2629 	    {
2630 		if (xp->xp_pattern[1] == '|')
2631 		{
2632 		    ++xp->xp_pattern;
2633 		    xp->xp_context = EXPAND_EXPRESSION;
2634 		}
2635 		else
2636 		    xp->xp_context = EXPAND_COMMANDS;
2637 	    }
2638 	    else
2639 		xp->xp_context = EXPAND_EXPRESSION;
2640 	}
2641 	else
2642 	    /* Doesn't look like something valid, expand as an expression
2643 	     * anyway. */
2644 	    xp->xp_context = EXPAND_EXPRESSION;
2645 	arg = xp->xp_pattern;
2646 	if (*arg != NUL)
2647 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
2648 		/* skip */ ;
2649     }
2650     xp->xp_pattern = arg;
2651 }
2652 
2653 #endif /* FEAT_CMDL_COMPL */
2654 
2655 /*
2656  * ":unlet[!] var1 ... " command.
2657  */
2658     void
2659 ex_unlet(exarg_T *eap)
2660 {
2661     ex_unletlock(eap, eap->arg, 0);
2662 }
2663 
2664 /*
2665  * ":lockvar" and ":unlockvar" commands
2666  */
2667     void
2668 ex_lockvar(exarg_T *eap)
2669 {
2670     char_u	*arg = eap->arg;
2671     int		deep = 2;
2672 
2673     if (eap->forceit)
2674 	deep = -1;
2675     else if (vim_isdigit(*arg))
2676     {
2677 	deep = getdigits(&arg);
2678 	arg = skipwhite(arg);
2679     }
2680 
2681     ex_unletlock(eap, arg, deep);
2682 }
2683 
2684 /*
2685  * ":unlet", ":lockvar" and ":unlockvar" are quite similar.
2686  */
2687     static void
2688 ex_unletlock(
2689     exarg_T	*eap,
2690     char_u	*argstart,
2691     int		deep)
2692 {
2693     char_u	*arg = argstart;
2694     char_u	*name_end;
2695     int		error = FALSE;
2696     lval_T	lv;
2697 
2698     do
2699     {
2700 	/* Parse the name and find the end. */
2701 	name_end = get_lval(arg, NULL, &lv, TRUE, eap->skip || error, 0,
2702 							     FNE_CHECK_START);
2703 	if (lv.ll_name == NULL)
2704 	    error = TRUE;	    /* error but continue parsing */
2705 	if (name_end == NULL || (!vim_iswhite(*name_end)
2706 						   && !ends_excmd(*name_end)))
2707 	{
2708 	    if (name_end != NULL)
2709 	    {
2710 		emsg_severe = TRUE;
2711 		EMSG(_(e_trailing));
2712 	    }
2713 	    if (!(eap->skip || error))
2714 		clear_lval(&lv);
2715 	    break;
2716 	}
2717 
2718 	if (!error && !eap->skip)
2719 	{
2720 	    if (eap->cmdidx == CMD_unlet)
2721 	    {
2722 		if (do_unlet_var(&lv, name_end, eap->forceit) == FAIL)
2723 		    error = TRUE;
2724 	    }
2725 	    else
2726 	    {
2727 		if (do_lock_var(&lv, name_end, deep,
2728 					  eap->cmdidx == CMD_lockvar) == FAIL)
2729 		    error = TRUE;
2730 	    }
2731 	}
2732 
2733 	if (!eap->skip)
2734 	    clear_lval(&lv);
2735 
2736 	arg = skipwhite(name_end);
2737     } while (!ends_excmd(*arg));
2738 
2739     eap->nextcmd = check_nextcmd(arg);
2740 }
2741 
2742     static int
2743 do_unlet_var(
2744     lval_T	*lp,
2745     char_u	*name_end,
2746     int		forceit)
2747 {
2748     int		ret = OK;
2749     int		cc;
2750 
2751     if (lp->ll_tv == NULL)
2752     {
2753 	cc = *name_end;
2754 	*name_end = NUL;
2755 
2756 	/* Normal name or expanded name. */
2757 	if (check_changedtick(lp->ll_name))
2758 	    ret = FAIL;
2759 	else if (do_unlet(lp->ll_name, forceit) == FAIL)
2760 	    ret = FAIL;
2761 	*name_end = cc;
2762     }
2763     else if ((lp->ll_list != NULL
2764 		   && tv_check_lock(lp->ll_list->lv_lock, lp->ll_name, FALSE))
2765 	    || (lp->ll_dict != NULL
2766 		  && tv_check_lock(lp->ll_dict->dv_lock, lp->ll_name, FALSE)))
2767 	return FAIL;
2768     else if (lp->ll_range)
2769     {
2770 	listitem_T    *li;
2771 	listitem_T    *ll_li = lp->ll_li;
2772 	int	      ll_n1 = lp->ll_n1;
2773 
2774 	while (ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= ll_n1))
2775 	{
2776 	    li = ll_li->li_next;
2777 	    if (tv_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
2778 		return FAIL;
2779 	    ll_li = li;
2780 	    ++ll_n1;
2781 	}
2782 
2783 	/* Delete a range of List items. */
2784 	while (lp->ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
2785 	{
2786 	    li = lp->ll_li->li_next;
2787 	    listitem_remove(lp->ll_list, lp->ll_li);
2788 	    lp->ll_li = li;
2789 	    ++lp->ll_n1;
2790 	}
2791     }
2792     else
2793     {
2794 	if (lp->ll_list != NULL)
2795 	    /* unlet a List item. */
2796 	    listitem_remove(lp->ll_list, lp->ll_li);
2797 	else
2798 	    /* unlet a Dictionary item. */
2799 	    dictitem_remove(lp->ll_dict, lp->ll_di);
2800     }
2801 
2802     return ret;
2803 }
2804 
2805 /*
2806  * "unlet" a variable.  Return OK if it existed, FAIL if not.
2807  * When "forceit" is TRUE don't complain if the variable doesn't exist.
2808  */
2809     int
2810 do_unlet(char_u *name, int forceit)
2811 {
2812     hashtab_T	*ht;
2813     hashitem_T	*hi;
2814     char_u	*varname;
2815     dict_T	*d;
2816     dictitem_T	*di;
2817 
2818     ht = find_var_ht(name, &varname);
2819     if (ht != NULL && *varname != NUL)
2820     {
2821 	d = get_current_funccal_dict(ht);
2822 	if (d == NULL)
2823 	{
2824 	    if (ht == &globvarht)
2825 		d = &globvardict;
2826 	    else if (ht == &compat_hashtab)
2827 		d = &vimvardict;
2828 	    else
2829 	    {
2830 		di = find_var_in_ht(ht, *name, (char_u *)"", FALSE);
2831 		d = di == NULL ? NULL : di->di_tv.vval.v_dict;
2832 	    }
2833 	    if (d == NULL)
2834 	    {
2835 		EMSG2(_(e_intern2), "do_unlet()");
2836 		return FAIL;
2837 	    }
2838 	}
2839 	hi = hash_find(ht, varname);
2840 	if (HASHITEM_EMPTY(hi))
2841 	    hi = find_hi_in_scoped_ht(name, &varname, &ht);
2842 	if (hi != NULL && !HASHITEM_EMPTY(hi))
2843 	{
2844 	    di = HI2DI(hi);
2845 	    if (var_check_fixed(di->di_flags, name, FALSE)
2846 		    || var_check_ro(di->di_flags, name, FALSE)
2847 		    || tv_check_lock(d->dv_lock, name, FALSE))
2848 		return FAIL;
2849 
2850 	    delete_var(ht, hi);
2851 	    return OK;
2852 	}
2853     }
2854     if (forceit)
2855 	return OK;
2856     EMSG2(_("E108: No such variable: \"%s\""), name);
2857     return FAIL;
2858 }
2859 
2860 /*
2861  * Lock or unlock variable indicated by "lp".
2862  * "deep" is the levels to go (-1 for unlimited);
2863  * "lock" is TRUE for ":lockvar", FALSE for ":unlockvar".
2864  */
2865     static int
2866 do_lock_var(
2867     lval_T	*lp,
2868     char_u	*name_end,
2869     int		deep,
2870     int		lock)
2871 {
2872     int		ret = OK;
2873     int		cc;
2874     dictitem_T	*di;
2875 
2876     if (deep == 0)	/* nothing to do */
2877 	return OK;
2878 
2879     if (lp->ll_tv == NULL)
2880     {
2881 	cc = *name_end;
2882 	*name_end = NUL;
2883 
2884 	/* Normal name or expanded name. */
2885 	if (check_changedtick(lp->ll_name))
2886 	    ret = FAIL;
2887 	else
2888 	{
2889 	    di = find_var(lp->ll_name, NULL, TRUE);
2890 	    if (di == NULL)
2891 		ret = FAIL;
2892 	    else
2893 	    {
2894 		if (lock)
2895 		    di->di_flags |= DI_FLAGS_LOCK;
2896 		else
2897 		    di->di_flags &= ~DI_FLAGS_LOCK;
2898 		item_lock(&di->di_tv, deep, lock);
2899 	    }
2900 	}
2901 	*name_end = cc;
2902     }
2903     else if (lp->ll_range)
2904     {
2905 	listitem_T    *li = lp->ll_li;
2906 
2907 	/* (un)lock a range of List items. */
2908 	while (li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
2909 	{
2910 	    item_lock(&li->li_tv, deep, lock);
2911 	    li = li->li_next;
2912 	    ++lp->ll_n1;
2913 	}
2914     }
2915     else if (lp->ll_list != NULL)
2916 	/* (un)lock a List item. */
2917 	item_lock(&lp->ll_li->li_tv, deep, lock);
2918     else
2919 	/* (un)lock a Dictionary item. */
2920 	item_lock(&lp->ll_di->di_tv, deep, lock);
2921 
2922     return ret;
2923 }
2924 
2925 /*
2926  * Lock or unlock an item.  "deep" is nr of levels to go.
2927  */
2928     static void
2929 item_lock(typval_T *tv, int deep, int lock)
2930 {
2931     static int	recurse = 0;
2932     list_T	*l;
2933     listitem_T	*li;
2934     dict_T	*d;
2935     hashitem_T	*hi;
2936     int		todo;
2937 
2938     if (recurse >= DICT_MAXNEST)
2939     {
2940 	EMSG(_("E743: variable nested too deep for (un)lock"));
2941 	return;
2942     }
2943     if (deep == 0)
2944 	return;
2945     ++recurse;
2946 
2947     /* lock/unlock the item itself */
2948     if (lock)
2949 	tv->v_lock |= VAR_LOCKED;
2950     else
2951 	tv->v_lock &= ~VAR_LOCKED;
2952 
2953     switch (tv->v_type)
2954     {
2955 	case VAR_UNKNOWN:
2956 	case VAR_NUMBER:
2957 	case VAR_STRING:
2958 	case VAR_FUNC:
2959 	case VAR_PARTIAL:
2960 	case VAR_FLOAT:
2961 	case VAR_SPECIAL:
2962 	case VAR_JOB:
2963 	case VAR_CHANNEL:
2964 	    break;
2965 
2966 	case VAR_LIST:
2967 	    if ((l = tv->vval.v_list) != NULL)
2968 	    {
2969 		if (lock)
2970 		    l->lv_lock |= VAR_LOCKED;
2971 		else
2972 		    l->lv_lock &= ~VAR_LOCKED;
2973 		if (deep < 0 || deep > 1)
2974 		    /* recursive: lock/unlock the items the List contains */
2975 		    for (li = l->lv_first; li != NULL; li = li->li_next)
2976 			item_lock(&li->li_tv, deep - 1, lock);
2977 	    }
2978 	    break;
2979 	case VAR_DICT:
2980 	    if ((d = tv->vval.v_dict) != NULL)
2981 	    {
2982 		if (lock)
2983 		    d->dv_lock |= VAR_LOCKED;
2984 		else
2985 		    d->dv_lock &= ~VAR_LOCKED;
2986 		if (deep < 0 || deep > 1)
2987 		{
2988 		    /* recursive: lock/unlock the items the List contains */
2989 		    todo = (int)d->dv_hashtab.ht_used;
2990 		    for (hi = d->dv_hashtab.ht_array; todo > 0; ++hi)
2991 		    {
2992 			if (!HASHITEM_EMPTY(hi))
2993 			{
2994 			    --todo;
2995 			    item_lock(&HI2DI(hi)->di_tv, deep - 1, lock);
2996 			}
2997 		    }
2998 		}
2999 	    }
3000     }
3001     --recurse;
3002 }
3003 
3004 #if (defined(FEAT_MENU) && defined(FEAT_MULTI_LANG)) || defined(PROTO)
3005 /*
3006  * Delete all "menutrans_" variables.
3007  */
3008     void
3009 del_menutrans_vars(void)
3010 {
3011     hashitem_T	*hi;
3012     int		todo;
3013 
3014     hash_lock(&globvarht);
3015     todo = (int)globvarht.ht_used;
3016     for (hi = globvarht.ht_array; todo > 0 && !got_int; ++hi)
3017     {
3018 	if (!HASHITEM_EMPTY(hi))
3019 	{
3020 	    --todo;
3021 	    if (STRNCMP(HI2DI(hi)->di_key, "menutrans_", 10) == 0)
3022 		delete_var(&globvarht, hi);
3023 	}
3024     }
3025     hash_unlock(&globvarht);
3026 }
3027 #endif
3028 
3029 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
3030 
3031 /*
3032  * Local string buffer for the next two functions to store a variable name
3033  * with its prefix. Allocated in cat_prefix_varname(), freed later in
3034  * get_user_var_name().
3035  */
3036 
3037 static char_u *cat_prefix_varname(int prefix, char_u *name);
3038 
3039 static char_u	*varnamebuf = NULL;
3040 static int	varnamebuflen = 0;
3041 
3042 /*
3043  * Function to concatenate a prefix and a variable name.
3044  */
3045     static char_u *
3046 cat_prefix_varname(int prefix, char_u *name)
3047 {
3048     int		len;
3049 
3050     len = (int)STRLEN(name) + 3;
3051     if (len > varnamebuflen)
3052     {
3053 	vim_free(varnamebuf);
3054 	len += 10;			/* some additional space */
3055 	varnamebuf = alloc(len);
3056 	if (varnamebuf == NULL)
3057 	{
3058 	    varnamebuflen = 0;
3059 	    return NULL;
3060 	}
3061 	varnamebuflen = len;
3062     }
3063     *varnamebuf = prefix;
3064     varnamebuf[1] = ':';
3065     STRCPY(varnamebuf + 2, name);
3066     return varnamebuf;
3067 }
3068 
3069 /*
3070  * Function given to ExpandGeneric() to obtain the list of user defined
3071  * (global/buffer/window/built-in) variable names.
3072  */
3073     char_u *
3074 get_user_var_name(expand_T *xp, int idx)
3075 {
3076     static long_u	gdone;
3077     static long_u	bdone;
3078     static long_u	wdone;
3079 #ifdef FEAT_WINDOWS
3080     static long_u	tdone;
3081 #endif
3082     static int		vidx;
3083     static hashitem_T	*hi;
3084     hashtab_T		*ht;
3085 
3086     if (idx == 0)
3087     {
3088 	gdone = bdone = wdone = vidx = 0;
3089 #ifdef FEAT_WINDOWS
3090 	tdone = 0;
3091 #endif
3092     }
3093 
3094     /* Global variables */
3095     if (gdone < globvarht.ht_used)
3096     {
3097 	if (gdone++ == 0)
3098 	    hi = globvarht.ht_array;
3099 	else
3100 	    ++hi;
3101 	while (HASHITEM_EMPTY(hi))
3102 	    ++hi;
3103 	if (STRNCMP("g:", xp->xp_pattern, 2) == 0)
3104 	    return cat_prefix_varname('g', hi->hi_key);
3105 	return hi->hi_key;
3106     }
3107 
3108     /* b: variables */
3109     ht = &curbuf->b_vars->dv_hashtab;
3110     if (bdone < ht->ht_used)
3111     {
3112 	if (bdone++ == 0)
3113 	    hi = ht->ht_array;
3114 	else
3115 	    ++hi;
3116 	while (HASHITEM_EMPTY(hi))
3117 	    ++hi;
3118 	return cat_prefix_varname('b', hi->hi_key);
3119     }
3120     if (bdone == ht->ht_used)
3121     {
3122 	++bdone;
3123 	return (char_u *)"b:changedtick";
3124     }
3125 
3126     /* w: variables */
3127     ht = &curwin->w_vars->dv_hashtab;
3128     if (wdone < ht->ht_used)
3129     {
3130 	if (wdone++ == 0)
3131 	    hi = ht->ht_array;
3132 	else
3133 	    ++hi;
3134 	while (HASHITEM_EMPTY(hi))
3135 	    ++hi;
3136 	return cat_prefix_varname('w', hi->hi_key);
3137     }
3138 
3139 #ifdef FEAT_WINDOWS
3140     /* t: variables */
3141     ht = &curtab->tp_vars->dv_hashtab;
3142     if (tdone < ht->ht_used)
3143     {
3144 	if (tdone++ == 0)
3145 	    hi = ht->ht_array;
3146 	else
3147 	    ++hi;
3148 	while (HASHITEM_EMPTY(hi))
3149 	    ++hi;
3150 	return cat_prefix_varname('t', hi->hi_key);
3151     }
3152 #endif
3153 
3154     /* v: variables */
3155     if (vidx < VV_LEN)
3156 	return cat_prefix_varname('v', (char_u *)vimvars[vidx++].vv_name);
3157 
3158     vim_free(varnamebuf);
3159     varnamebuf = NULL;
3160     varnamebuflen = 0;
3161     return NULL;
3162 }
3163 
3164 #endif /* FEAT_CMDL_COMPL */
3165 
3166 /*
3167  * Return TRUE if "pat" matches "text".
3168  * Does not use 'cpo' and always uses 'magic'.
3169  */
3170     static int
3171 pattern_match(char_u *pat, char_u *text, int ic)
3172 {
3173     int		matches = FALSE;
3174     char_u	*save_cpo;
3175     regmatch_T	regmatch;
3176 
3177     /* avoid 'l' flag in 'cpoptions' */
3178     save_cpo = p_cpo;
3179     p_cpo = (char_u *)"";
3180     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
3181     if (regmatch.regprog != NULL)
3182     {
3183 	regmatch.rm_ic = ic;
3184 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
3185 	vim_regfree(regmatch.regprog);
3186     }
3187     p_cpo = save_cpo;
3188     return matches;
3189 }
3190 
3191 /*
3192  * types for expressions.
3193  */
3194 typedef enum
3195 {
3196     TYPE_UNKNOWN = 0
3197     , TYPE_EQUAL	/* == */
3198     , TYPE_NEQUAL	/* != */
3199     , TYPE_GREATER	/* >  */
3200     , TYPE_GEQUAL	/* >= */
3201     , TYPE_SMALLER	/* <  */
3202     , TYPE_SEQUAL	/* <= */
3203     , TYPE_MATCH	/* =~ */
3204     , TYPE_NOMATCH	/* !~ */
3205 } exptype_T;
3206 
3207 /*
3208  * The "evaluate" argument: When FALSE, the argument is only parsed but not
3209  * executed.  The function may return OK, but the rettv will be of type
3210  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
3211  */
3212 
3213 /*
3214  * Handle zero level expression.
3215  * This calls eval1() and handles error message and nextcmd.
3216  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
3217  * Note: "rettv.v_lock" is not set.
3218  * Return OK or FAIL.
3219  */
3220     int
3221 eval0(
3222     char_u	*arg,
3223     typval_T	*rettv,
3224     char_u	**nextcmd,
3225     int		evaluate)
3226 {
3227     int		ret;
3228     char_u	*p;
3229 
3230     p = skipwhite(arg);
3231     ret = eval1(&p, rettv, evaluate);
3232     if (ret == FAIL || !ends_excmd(*p))
3233     {
3234 	if (ret != FAIL)
3235 	    clear_tv(rettv);
3236 	/*
3237 	 * Report the invalid expression unless the expression evaluation has
3238 	 * been cancelled due to an aborting error, an interrupt, or an
3239 	 * exception.
3240 	 */
3241 	if (!aborting())
3242 	    EMSG2(_(e_invexpr2), arg);
3243 	ret = FAIL;
3244     }
3245     if (nextcmd != NULL)
3246 	*nextcmd = check_nextcmd(p);
3247 
3248     return ret;
3249 }
3250 
3251 /*
3252  * Handle top level expression:
3253  *	expr2 ? expr1 : expr1
3254  *
3255  * "arg" must point to the first non-white of the expression.
3256  * "arg" is advanced to the next non-white after the recognized expression.
3257  *
3258  * Note: "rettv.v_lock" is not set.
3259  *
3260  * Return OK or FAIL.
3261  */
3262     int
3263 eval1(char_u **arg, typval_T *rettv, int evaluate)
3264 {
3265     int		result;
3266     typval_T	var2;
3267 
3268     /*
3269      * Get the first variable.
3270      */
3271     if (eval2(arg, rettv, evaluate) == FAIL)
3272 	return FAIL;
3273 
3274     if ((*arg)[0] == '?')
3275     {
3276 	result = FALSE;
3277 	if (evaluate)
3278 	{
3279 	    int		error = FALSE;
3280 
3281 	    if (get_tv_number_chk(rettv, &error) != 0)
3282 		result = TRUE;
3283 	    clear_tv(rettv);
3284 	    if (error)
3285 		return FAIL;
3286 	}
3287 
3288 	/*
3289 	 * Get the second variable.
3290 	 */
3291 	*arg = skipwhite(*arg + 1);
3292 	if (eval1(arg, rettv, evaluate && result) == FAIL) /* recursive! */
3293 	    return FAIL;
3294 
3295 	/*
3296 	 * Check for the ":".
3297 	 */
3298 	if ((*arg)[0] != ':')
3299 	{
3300 	    EMSG(_("E109: Missing ':' after '?'"));
3301 	    if (evaluate && result)
3302 		clear_tv(rettv);
3303 	    return FAIL;
3304 	}
3305 
3306 	/*
3307 	 * Get the third variable.
3308 	 */
3309 	*arg = skipwhite(*arg + 1);
3310 	if (eval1(arg, &var2, evaluate && !result) == FAIL) /* recursive! */
3311 	{
3312 	    if (evaluate && result)
3313 		clear_tv(rettv);
3314 	    return FAIL;
3315 	}
3316 	if (evaluate && !result)
3317 	    *rettv = var2;
3318     }
3319 
3320     return OK;
3321 }
3322 
3323 /*
3324  * Handle first level expression:
3325  *	expr2 || expr2 || expr2	    logical OR
3326  *
3327  * "arg" must point to the first non-white of the expression.
3328  * "arg" is advanced to the next non-white after the recognized expression.
3329  *
3330  * Return OK or FAIL.
3331  */
3332     static int
3333 eval2(char_u **arg, typval_T *rettv, int evaluate)
3334 {
3335     typval_T	var2;
3336     long	result;
3337     int		first;
3338     int		error = FALSE;
3339 
3340     /*
3341      * Get the first variable.
3342      */
3343     if (eval3(arg, rettv, evaluate) == FAIL)
3344 	return FAIL;
3345 
3346     /*
3347      * Repeat until there is no following "||".
3348      */
3349     first = TRUE;
3350     result = FALSE;
3351     while ((*arg)[0] == '|' && (*arg)[1] == '|')
3352     {
3353 	if (evaluate && first)
3354 	{
3355 	    if (get_tv_number_chk(rettv, &error) != 0)
3356 		result = TRUE;
3357 	    clear_tv(rettv);
3358 	    if (error)
3359 		return FAIL;
3360 	    first = FALSE;
3361 	}
3362 
3363 	/*
3364 	 * Get the second variable.
3365 	 */
3366 	*arg = skipwhite(*arg + 2);
3367 	if (eval3(arg, &var2, evaluate && !result) == FAIL)
3368 	    return FAIL;
3369 
3370 	/*
3371 	 * Compute the result.
3372 	 */
3373 	if (evaluate && !result)
3374 	{
3375 	    if (get_tv_number_chk(&var2, &error) != 0)
3376 		result = TRUE;
3377 	    clear_tv(&var2);
3378 	    if (error)
3379 		return FAIL;
3380 	}
3381 	if (evaluate)
3382 	{
3383 	    rettv->v_type = VAR_NUMBER;
3384 	    rettv->vval.v_number = result;
3385 	}
3386     }
3387 
3388     return OK;
3389 }
3390 
3391 /*
3392  * Handle second level expression:
3393  *	expr3 && expr3 && expr3	    logical AND
3394  *
3395  * "arg" must point to the first non-white of the expression.
3396  * "arg" is advanced to the next non-white after the recognized expression.
3397  *
3398  * Return OK or FAIL.
3399  */
3400     static int
3401 eval3(char_u **arg, typval_T *rettv, int evaluate)
3402 {
3403     typval_T	var2;
3404     long	result;
3405     int		first;
3406     int		error = FALSE;
3407 
3408     /*
3409      * Get the first variable.
3410      */
3411     if (eval4(arg, rettv, evaluate) == FAIL)
3412 	return FAIL;
3413 
3414     /*
3415      * Repeat until there is no following "&&".
3416      */
3417     first = TRUE;
3418     result = TRUE;
3419     while ((*arg)[0] == '&' && (*arg)[1] == '&')
3420     {
3421 	if (evaluate && first)
3422 	{
3423 	    if (get_tv_number_chk(rettv, &error) == 0)
3424 		result = FALSE;
3425 	    clear_tv(rettv);
3426 	    if (error)
3427 		return FAIL;
3428 	    first = FALSE;
3429 	}
3430 
3431 	/*
3432 	 * Get the second variable.
3433 	 */
3434 	*arg = skipwhite(*arg + 2);
3435 	if (eval4(arg, &var2, evaluate && result) == FAIL)
3436 	    return FAIL;
3437 
3438 	/*
3439 	 * Compute the result.
3440 	 */
3441 	if (evaluate && result)
3442 	{
3443 	    if (get_tv_number_chk(&var2, &error) == 0)
3444 		result = FALSE;
3445 	    clear_tv(&var2);
3446 	    if (error)
3447 		return FAIL;
3448 	}
3449 	if (evaluate)
3450 	{
3451 	    rettv->v_type = VAR_NUMBER;
3452 	    rettv->vval.v_number = result;
3453 	}
3454     }
3455 
3456     return OK;
3457 }
3458 
3459 /*
3460  * Handle third level expression:
3461  *	var1 == var2
3462  *	var1 =~ var2
3463  *	var1 != var2
3464  *	var1 !~ var2
3465  *	var1 > var2
3466  *	var1 >= var2
3467  *	var1 < var2
3468  *	var1 <= var2
3469  *	var1 is var2
3470  *	var1 isnot var2
3471  *
3472  * "arg" must point to the first non-white of the expression.
3473  * "arg" is advanced to the next non-white after the recognized expression.
3474  *
3475  * Return OK or FAIL.
3476  */
3477     static int
3478 eval4(char_u **arg, typval_T *rettv, int evaluate)
3479 {
3480     typval_T	var2;
3481     char_u	*p;
3482     int		i;
3483     exptype_T	type = TYPE_UNKNOWN;
3484     int		type_is = FALSE;    /* TRUE for "is" and "isnot" */
3485     int		len = 2;
3486     varnumber_T	n1, n2;
3487     char_u	*s1, *s2;
3488     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3489     int		ic;
3490 
3491     /*
3492      * Get the first variable.
3493      */
3494     if (eval5(arg, rettv, evaluate) == FAIL)
3495 	return FAIL;
3496 
3497     p = *arg;
3498     switch (p[0])
3499     {
3500 	case '=':   if (p[1] == '=')
3501 			type = TYPE_EQUAL;
3502 		    else if (p[1] == '~')
3503 			type = TYPE_MATCH;
3504 		    break;
3505 	case '!':   if (p[1] == '=')
3506 			type = TYPE_NEQUAL;
3507 		    else if (p[1] == '~')
3508 			type = TYPE_NOMATCH;
3509 		    break;
3510 	case '>':   if (p[1] != '=')
3511 		    {
3512 			type = TYPE_GREATER;
3513 			len = 1;
3514 		    }
3515 		    else
3516 			type = TYPE_GEQUAL;
3517 		    break;
3518 	case '<':   if (p[1] != '=')
3519 		    {
3520 			type = TYPE_SMALLER;
3521 			len = 1;
3522 		    }
3523 		    else
3524 			type = TYPE_SEQUAL;
3525 		    break;
3526 	case 'i':   if (p[1] == 's')
3527 		    {
3528 			if (p[2] == 'n' && p[3] == 'o' && p[4] == 't')
3529 			    len = 5;
3530 			i = p[len];
3531 			if (!isalnum(i) && i != '_')
3532 			{
3533 			    type = len == 2 ? TYPE_EQUAL : TYPE_NEQUAL;
3534 			    type_is = TRUE;
3535 			}
3536 		    }
3537 		    break;
3538     }
3539 
3540     /*
3541      * If there is a comparative operator, use it.
3542      */
3543     if (type != TYPE_UNKNOWN)
3544     {
3545 	/* extra question mark appended: ignore case */
3546 	if (p[len] == '?')
3547 	{
3548 	    ic = TRUE;
3549 	    ++len;
3550 	}
3551 	/* extra '#' appended: match case */
3552 	else if (p[len] == '#')
3553 	{
3554 	    ic = FALSE;
3555 	    ++len;
3556 	}
3557 	/* nothing appended: use 'ignorecase' */
3558 	else
3559 	    ic = p_ic;
3560 
3561 	/*
3562 	 * Get the second variable.
3563 	 */
3564 	*arg = skipwhite(p + len);
3565 	if (eval5(arg, &var2, evaluate) == FAIL)
3566 	{
3567 	    clear_tv(rettv);
3568 	    return FAIL;
3569 	}
3570 
3571 	if (evaluate)
3572 	{
3573 	    if (type_is && rettv->v_type != var2.v_type)
3574 	    {
3575 		/* For "is" a different type always means FALSE, for "notis"
3576 		 * it means TRUE. */
3577 		n1 = (type == TYPE_NEQUAL);
3578 	    }
3579 	    else if (rettv->v_type == VAR_LIST || var2.v_type == VAR_LIST)
3580 	    {
3581 		if (type_is)
3582 		{
3583 		    n1 = (rettv->v_type == var2.v_type
3584 				   && rettv->vval.v_list == var2.vval.v_list);
3585 		    if (type == TYPE_NEQUAL)
3586 			n1 = !n1;
3587 		}
3588 		else if (rettv->v_type != var2.v_type
3589 			|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
3590 		{
3591 		    if (rettv->v_type != var2.v_type)
3592 			EMSG(_("E691: Can only compare List with List"));
3593 		    else
3594 			EMSG(_("E692: Invalid operation for List"));
3595 		    clear_tv(rettv);
3596 		    clear_tv(&var2);
3597 		    return FAIL;
3598 		}
3599 		else
3600 		{
3601 		    /* Compare two Lists for being equal or unequal. */
3602 		    n1 = list_equal(rettv->vval.v_list, var2.vval.v_list,
3603 								   ic, FALSE);
3604 		    if (type == TYPE_NEQUAL)
3605 			n1 = !n1;
3606 		}
3607 	    }
3608 
3609 	    else if (rettv->v_type == VAR_DICT || var2.v_type == VAR_DICT)
3610 	    {
3611 		if (type_is)
3612 		{
3613 		    n1 = (rettv->v_type == var2.v_type
3614 				   && rettv->vval.v_dict == var2.vval.v_dict);
3615 		    if (type == TYPE_NEQUAL)
3616 			n1 = !n1;
3617 		}
3618 		else if (rettv->v_type != var2.v_type
3619 			|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
3620 		{
3621 		    if (rettv->v_type != var2.v_type)
3622 			EMSG(_("E735: Can only compare Dictionary with Dictionary"));
3623 		    else
3624 			EMSG(_("E736: Invalid operation for Dictionary"));
3625 		    clear_tv(rettv);
3626 		    clear_tv(&var2);
3627 		    return FAIL;
3628 		}
3629 		else
3630 		{
3631 		    /* Compare two Dictionaries for being equal or unequal. */
3632 		    n1 = dict_equal(rettv->vval.v_dict, var2.vval.v_dict,
3633 								   ic, FALSE);
3634 		    if (type == TYPE_NEQUAL)
3635 			n1 = !n1;
3636 		}
3637 	    }
3638 
3639 	    else if (rettv->v_type == VAR_FUNC || var2.v_type == VAR_FUNC
3640 		|| rettv->v_type == VAR_PARTIAL || var2.v_type == VAR_PARTIAL)
3641 	    {
3642 		if (type != TYPE_EQUAL && type != TYPE_NEQUAL)
3643 		{
3644 		    EMSG(_("E694: Invalid operation for Funcrefs"));
3645 		    clear_tv(rettv);
3646 		    clear_tv(&var2);
3647 		    return FAIL;
3648 		}
3649 		if ((rettv->v_type == VAR_PARTIAL
3650 					     && rettv->vval.v_partial == NULL)
3651 			|| (var2.v_type == VAR_PARTIAL
3652 					      && var2.vval.v_partial == NULL))
3653 		    /* when a partial is NULL assume not equal */
3654 		    n1 = FALSE;
3655 		else if (type_is)
3656 		{
3657 		    if (rettv->v_type == VAR_FUNC && var2.v_type == VAR_FUNC)
3658 			/* strings are considered the same if their value is
3659 			 * the same */
3660 			n1 = tv_equal(rettv, &var2, ic, FALSE);
3661 		    else if (rettv->v_type == VAR_PARTIAL
3662 						&& var2.v_type == VAR_PARTIAL)
3663 			n1 = (rettv->vval.v_partial == var2.vval.v_partial);
3664 		    else
3665 			n1 = FALSE;
3666 		}
3667 		else
3668 		    n1 = tv_equal(rettv, &var2, ic, FALSE);
3669 		if (type == TYPE_NEQUAL)
3670 		    n1 = !n1;
3671 	    }
3672 
3673 #ifdef FEAT_FLOAT
3674 	    /*
3675 	     * If one of the two variables is a float, compare as a float.
3676 	     * When using "=~" or "!~", always compare as string.
3677 	     */
3678 	    else if ((rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3679 		    && type != TYPE_MATCH && type != TYPE_NOMATCH)
3680 	    {
3681 		float_T f1, f2;
3682 
3683 		if (rettv->v_type == VAR_FLOAT)
3684 		    f1 = rettv->vval.v_float;
3685 		else
3686 		    f1 = get_tv_number(rettv);
3687 		if (var2.v_type == VAR_FLOAT)
3688 		    f2 = var2.vval.v_float;
3689 		else
3690 		    f2 = get_tv_number(&var2);
3691 		n1 = FALSE;
3692 		switch (type)
3693 		{
3694 		    case TYPE_EQUAL:    n1 = (f1 == f2); break;
3695 		    case TYPE_NEQUAL:   n1 = (f1 != f2); break;
3696 		    case TYPE_GREATER:  n1 = (f1 > f2); break;
3697 		    case TYPE_GEQUAL:   n1 = (f1 >= f2); break;
3698 		    case TYPE_SMALLER:  n1 = (f1 < f2); break;
3699 		    case TYPE_SEQUAL:   n1 = (f1 <= f2); break;
3700 		    case TYPE_UNKNOWN:
3701 		    case TYPE_MATCH:
3702 		    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
3703 		}
3704 	    }
3705 #endif
3706 
3707 	    /*
3708 	     * If one of the two variables is a number, compare as a number.
3709 	     * When using "=~" or "!~", always compare as string.
3710 	     */
3711 	    else if ((rettv->v_type == VAR_NUMBER || var2.v_type == VAR_NUMBER)
3712 		    && type != TYPE_MATCH && type != TYPE_NOMATCH)
3713 	    {
3714 		n1 = get_tv_number(rettv);
3715 		n2 = get_tv_number(&var2);
3716 		switch (type)
3717 		{
3718 		    case TYPE_EQUAL:    n1 = (n1 == n2); break;
3719 		    case TYPE_NEQUAL:   n1 = (n1 != n2); break;
3720 		    case TYPE_GREATER:  n1 = (n1 > n2); break;
3721 		    case TYPE_GEQUAL:   n1 = (n1 >= n2); break;
3722 		    case TYPE_SMALLER:  n1 = (n1 < n2); break;
3723 		    case TYPE_SEQUAL:   n1 = (n1 <= n2); break;
3724 		    case TYPE_UNKNOWN:
3725 		    case TYPE_MATCH:
3726 		    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
3727 		}
3728 	    }
3729 	    else
3730 	    {
3731 		s1 = get_tv_string_buf(rettv, buf1);
3732 		s2 = get_tv_string_buf(&var2, buf2);
3733 		if (type != TYPE_MATCH && type != TYPE_NOMATCH)
3734 		    i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
3735 		else
3736 		    i = 0;
3737 		n1 = FALSE;
3738 		switch (type)
3739 		{
3740 		    case TYPE_EQUAL:    n1 = (i == 0); break;
3741 		    case TYPE_NEQUAL:   n1 = (i != 0); break;
3742 		    case TYPE_GREATER:  n1 = (i > 0); break;
3743 		    case TYPE_GEQUAL:   n1 = (i >= 0); break;
3744 		    case TYPE_SMALLER:  n1 = (i < 0); break;
3745 		    case TYPE_SEQUAL:   n1 = (i <= 0); break;
3746 
3747 		    case TYPE_MATCH:
3748 		    case TYPE_NOMATCH:
3749 			    n1 = pattern_match(s2, s1, ic);
3750 			    if (type == TYPE_NOMATCH)
3751 				n1 = !n1;
3752 			    break;
3753 
3754 		    case TYPE_UNKNOWN:  break;  /* avoid gcc warning */
3755 		}
3756 	    }
3757 	    clear_tv(rettv);
3758 	    clear_tv(&var2);
3759 	    rettv->v_type = VAR_NUMBER;
3760 	    rettv->vval.v_number = n1;
3761 	}
3762     }
3763 
3764     return OK;
3765 }
3766 
3767 /*
3768  * Handle fourth level expression:
3769  *	+	number addition
3770  *	-	number subtraction
3771  *	.	string concatenation
3772  *
3773  * "arg" must point to the first non-white of the expression.
3774  * "arg" is advanced to the next non-white after the recognized expression.
3775  *
3776  * Return OK or FAIL.
3777  */
3778     static int
3779 eval5(char_u **arg, typval_T *rettv, int evaluate)
3780 {
3781     typval_T	var2;
3782     typval_T	var3;
3783     int		op;
3784     varnumber_T	n1, n2;
3785 #ifdef FEAT_FLOAT
3786     float_T	f1 = 0, f2 = 0;
3787 #endif
3788     char_u	*s1, *s2;
3789     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3790     char_u	*p;
3791 
3792     /*
3793      * Get the first variable.
3794      */
3795     if (eval6(arg, rettv, evaluate, FALSE) == FAIL)
3796 	return FAIL;
3797 
3798     /*
3799      * Repeat computing, until no '+', '-' or '.' is following.
3800      */
3801     for (;;)
3802     {
3803 	op = **arg;
3804 	if (op != '+' && op != '-' && op != '.')
3805 	    break;
3806 
3807 	if ((op != '+' || rettv->v_type != VAR_LIST)
3808 #ifdef FEAT_FLOAT
3809 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
3810 #endif
3811 		)
3812 	{
3813 	    /* For "list + ...", an illegal use of the first operand as
3814 	     * a number cannot be determined before evaluating the 2nd
3815 	     * operand: if this is also a list, all is ok.
3816 	     * For "something . ...", "something - ..." or "non-list + ...",
3817 	     * we know that the first operand needs to be a string or number
3818 	     * without evaluating the 2nd operand.  So check before to avoid
3819 	     * side effects after an error. */
3820 	    if (evaluate && get_tv_string_chk(rettv) == NULL)
3821 	    {
3822 		clear_tv(rettv);
3823 		return FAIL;
3824 	    }
3825 	}
3826 
3827 	/*
3828 	 * Get the second variable.
3829 	 */
3830 	*arg = skipwhite(*arg + 1);
3831 	if (eval6(arg, &var2, evaluate, op == '.') == FAIL)
3832 	{
3833 	    clear_tv(rettv);
3834 	    return FAIL;
3835 	}
3836 
3837 	if (evaluate)
3838 	{
3839 	    /*
3840 	     * Compute the result.
3841 	     */
3842 	    if (op == '.')
3843 	    {
3844 		s1 = get_tv_string_buf(rettv, buf1);	/* already checked */
3845 		s2 = get_tv_string_buf_chk(&var2, buf2);
3846 		if (s2 == NULL)		/* type error ? */
3847 		{
3848 		    clear_tv(rettv);
3849 		    clear_tv(&var2);
3850 		    return FAIL;
3851 		}
3852 		p = concat_str(s1, s2);
3853 		clear_tv(rettv);
3854 		rettv->v_type = VAR_STRING;
3855 		rettv->vval.v_string = p;
3856 	    }
3857 	    else if (op == '+' && rettv->v_type == VAR_LIST
3858 						   && var2.v_type == VAR_LIST)
3859 	    {
3860 		/* concatenate Lists */
3861 		if (list_concat(rettv->vval.v_list, var2.vval.v_list,
3862 							       &var3) == FAIL)
3863 		{
3864 		    clear_tv(rettv);
3865 		    clear_tv(&var2);
3866 		    return FAIL;
3867 		}
3868 		clear_tv(rettv);
3869 		*rettv = var3;
3870 	    }
3871 	    else
3872 	    {
3873 		int	    error = FALSE;
3874 
3875 #ifdef FEAT_FLOAT
3876 		if (rettv->v_type == VAR_FLOAT)
3877 		{
3878 		    f1 = rettv->vval.v_float;
3879 		    n1 = 0;
3880 		}
3881 		else
3882 #endif
3883 		{
3884 		    n1 = get_tv_number_chk(rettv, &error);
3885 		    if (error)
3886 		    {
3887 			/* This can only happen for "list + non-list".  For
3888 			 * "non-list + ..." or "something - ...", we returned
3889 			 * before evaluating the 2nd operand. */
3890 			clear_tv(rettv);
3891 			return FAIL;
3892 		    }
3893 #ifdef FEAT_FLOAT
3894 		    if (var2.v_type == VAR_FLOAT)
3895 			f1 = n1;
3896 #endif
3897 		}
3898 #ifdef FEAT_FLOAT
3899 		if (var2.v_type == VAR_FLOAT)
3900 		{
3901 		    f2 = var2.vval.v_float;
3902 		    n2 = 0;
3903 		}
3904 		else
3905 #endif
3906 		{
3907 		    n2 = get_tv_number_chk(&var2, &error);
3908 		    if (error)
3909 		    {
3910 			clear_tv(rettv);
3911 			clear_tv(&var2);
3912 			return FAIL;
3913 		    }
3914 #ifdef FEAT_FLOAT
3915 		    if (rettv->v_type == VAR_FLOAT)
3916 			f2 = n2;
3917 #endif
3918 		}
3919 		clear_tv(rettv);
3920 
3921 #ifdef FEAT_FLOAT
3922 		/* If there is a float on either side the result is a float. */
3923 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3924 		{
3925 		    if (op == '+')
3926 			f1 = f1 + f2;
3927 		    else
3928 			f1 = f1 - f2;
3929 		    rettv->v_type = VAR_FLOAT;
3930 		    rettv->vval.v_float = f1;
3931 		}
3932 		else
3933 #endif
3934 		{
3935 		    if (op == '+')
3936 			n1 = n1 + n2;
3937 		    else
3938 			n1 = n1 - n2;
3939 		    rettv->v_type = VAR_NUMBER;
3940 		    rettv->vval.v_number = n1;
3941 		}
3942 	    }
3943 	    clear_tv(&var2);
3944 	}
3945     }
3946     return OK;
3947 }
3948 
3949 /*
3950  * Handle fifth level expression:
3951  *	*	number multiplication
3952  *	/	number division
3953  *	%	number modulo
3954  *
3955  * "arg" must point to the first non-white of the expression.
3956  * "arg" is advanced to the next non-white after the recognized expression.
3957  *
3958  * Return OK or FAIL.
3959  */
3960     static int
3961 eval6(
3962     char_u	**arg,
3963     typval_T	*rettv,
3964     int		evaluate,
3965     int		want_string)  /* after "." operator */
3966 {
3967     typval_T	var2;
3968     int		op;
3969     varnumber_T	n1, n2;
3970 #ifdef FEAT_FLOAT
3971     int		use_float = FALSE;
3972     float_T	f1 = 0, f2;
3973 #endif
3974     int		error = FALSE;
3975 
3976     /*
3977      * Get the first variable.
3978      */
3979     if (eval7(arg, rettv, evaluate, want_string) == FAIL)
3980 	return FAIL;
3981 
3982     /*
3983      * Repeat computing, until no '*', '/' or '%' is following.
3984      */
3985     for (;;)
3986     {
3987 	op = **arg;
3988 	if (op != '*' && op != '/' && op != '%')
3989 	    break;
3990 
3991 	if (evaluate)
3992 	{
3993 #ifdef FEAT_FLOAT
3994 	    if (rettv->v_type == VAR_FLOAT)
3995 	    {
3996 		f1 = rettv->vval.v_float;
3997 		use_float = TRUE;
3998 		n1 = 0;
3999 	    }
4000 	    else
4001 #endif
4002 		n1 = get_tv_number_chk(rettv, &error);
4003 	    clear_tv(rettv);
4004 	    if (error)
4005 		return FAIL;
4006 	}
4007 	else
4008 	    n1 = 0;
4009 
4010 	/*
4011 	 * Get the second variable.
4012 	 */
4013 	*arg = skipwhite(*arg + 1);
4014 	if (eval7(arg, &var2, evaluate, FALSE) == FAIL)
4015 	    return FAIL;
4016 
4017 	if (evaluate)
4018 	{
4019 #ifdef FEAT_FLOAT
4020 	    if (var2.v_type == VAR_FLOAT)
4021 	    {
4022 		if (!use_float)
4023 		{
4024 		    f1 = n1;
4025 		    use_float = TRUE;
4026 		}
4027 		f2 = var2.vval.v_float;
4028 		n2 = 0;
4029 	    }
4030 	    else
4031 #endif
4032 	    {
4033 		n2 = get_tv_number_chk(&var2, &error);
4034 		clear_tv(&var2);
4035 		if (error)
4036 		    return FAIL;
4037 #ifdef FEAT_FLOAT
4038 		if (use_float)
4039 		    f2 = n2;
4040 #endif
4041 	    }
4042 
4043 	    /*
4044 	     * Compute the result.
4045 	     * When either side is a float the result is a float.
4046 	     */
4047 #ifdef FEAT_FLOAT
4048 	    if (use_float)
4049 	    {
4050 		if (op == '*')
4051 		    f1 = f1 * f2;
4052 		else if (op == '/')
4053 		{
4054 # ifdef VMS
4055 		    /* VMS crashes on divide by zero, work around it */
4056 		    if (f2 == 0.0)
4057 		    {
4058 			if (f1 == 0)
4059 			    f1 = -1 * __F_FLT_MAX - 1L;   /* similar to NaN */
4060 			else if (f1 < 0)
4061 			    f1 = -1 * __F_FLT_MAX;
4062 			else
4063 			    f1 = __F_FLT_MAX;
4064 		    }
4065 		    else
4066 			f1 = f1 / f2;
4067 # else
4068 		    /* We rely on the floating point library to handle divide
4069 		     * by zero to result in "inf" and not a crash. */
4070 		    f1 = f1 / f2;
4071 # endif
4072 		}
4073 		else
4074 		{
4075 		    EMSG(_("E804: Cannot use '%' with Float"));
4076 		    return FAIL;
4077 		}
4078 		rettv->v_type = VAR_FLOAT;
4079 		rettv->vval.v_float = f1;
4080 	    }
4081 	    else
4082 #endif
4083 	    {
4084 		if (op == '*')
4085 		    n1 = n1 * n2;
4086 		else if (op == '/')
4087 		{
4088 		    if (n2 == 0)	/* give an error message? */
4089 		    {
4090 #ifdef FEAT_NUM64
4091 			if (n1 == 0)
4092 			    n1 = -0x7fffffffffffffff - 1; /* similar to NaN */
4093 			else if (n1 < 0)
4094 			    n1 = -0x7fffffffffffffff;
4095 			else
4096 			    n1 = 0x7fffffffffffffff;
4097 #else
4098 			if (n1 == 0)
4099 			    n1 = -0x7fffffffL - 1L;	/* similar to NaN */
4100 			else if (n1 < 0)
4101 			    n1 = -0x7fffffffL;
4102 			else
4103 			    n1 = 0x7fffffffL;
4104 #endif
4105 		    }
4106 		    else
4107 			n1 = n1 / n2;
4108 		}
4109 		else
4110 		{
4111 		    if (n2 == 0)	/* give an error message? */
4112 			n1 = 0;
4113 		    else
4114 			n1 = n1 % n2;
4115 		}
4116 		rettv->v_type = VAR_NUMBER;
4117 		rettv->vval.v_number = n1;
4118 	    }
4119 	}
4120     }
4121 
4122     return OK;
4123 }
4124 
4125 /*
4126  * Handle sixth level expression:
4127  *  number		number constant
4128  *  "string"		string constant
4129  *  'string'		literal string constant
4130  *  &option-name	option value
4131  *  @r			register contents
4132  *  identifier		variable value
4133  *  function()		function call
4134  *  $VAR		environment variable
4135  *  (expression)	nested expression
4136  *  [expr, expr]	List
4137  *  {key: val, key: val}  Dictionary
4138  *
4139  *  Also handle:
4140  *  ! in front		logical NOT
4141  *  - in front		unary minus
4142  *  + in front		unary plus (ignored)
4143  *  trailing []		subscript in String or List
4144  *  trailing .name	entry in Dictionary
4145  *
4146  * "arg" must point to the first non-white of the expression.
4147  * "arg" is advanced to the next non-white after the recognized expression.
4148  *
4149  * Return OK or FAIL.
4150  */
4151     static int
4152 eval7(
4153     char_u	**arg,
4154     typval_T	*rettv,
4155     int		evaluate,
4156     int		want_string UNUSED)	/* after "." operator */
4157 {
4158     varnumber_T	n;
4159     int		len;
4160     char_u	*s;
4161     char_u	*start_leader, *end_leader;
4162     int		ret = OK;
4163     char_u	*alias;
4164 
4165     /*
4166      * Initialise variable so that clear_tv() can't mistake this for a
4167      * string and free a string that isn't there.
4168      */
4169     rettv->v_type = VAR_UNKNOWN;
4170 
4171     /*
4172      * Skip '!' and '-' characters.  They are handled later.
4173      */
4174     start_leader = *arg;
4175     while (**arg == '!' || **arg == '-' || **arg == '+')
4176 	*arg = skipwhite(*arg + 1);
4177     end_leader = *arg;
4178 
4179     switch (**arg)
4180     {
4181     /*
4182      * Number constant.
4183      */
4184     case '0':
4185     case '1':
4186     case '2':
4187     case '3':
4188     case '4':
4189     case '5':
4190     case '6':
4191     case '7':
4192     case '8':
4193     case '9':
4194 	{
4195 #ifdef FEAT_FLOAT
4196 		char_u *p = skipdigits(*arg + 1);
4197 		int    get_float = FALSE;
4198 
4199 		/* We accept a float when the format matches
4200 		 * "[0-9]\+\.[0-9]\+\([eE][+-]\?[0-9]\+\)\?".  This is very
4201 		 * strict to avoid backwards compatibility problems.
4202 		 * Don't look for a float after the "." operator, so that
4203 		 * ":let vers = 1.2.3" doesn't fail. */
4204 		if (!want_string && p[0] == '.' && vim_isdigit(p[1]))
4205 		{
4206 		    get_float = TRUE;
4207 		    p = skipdigits(p + 2);
4208 		    if (*p == 'e' || *p == 'E')
4209 		    {
4210 			++p;
4211 			if (*p == '-' || *p == '+')
4212 			    ++p;
4213 			if (!vim_isdigit(*p))
4214 			    get_float = FALSE;
4215 			else
4216 			    p = skipdigits(p + 1);
4217 		    }
4218 		    if (ASCII_ISALPHA(*p) || *p == '.')
4219 			get_float = FALSE;
4220 		}
4221 		if (get_float)
4222 		{
4223 		    float_T	f;
4224 
4225 		    *arg += string2float(*arg, &f);
4226 		    if (evaluate)
4227 		    {
4228 			rettv->v_type = VAR_FLOAT;
4229 			rettv->vval.v_float = f;
4230 		    }
4231 		}
4232 		else
4233 #endif
4234 		{
4235 		    vim_str2nr(*arg, NULL, &len, STR2NR_ALL, &n, NULL, 0);
4236 		    *arg += len;
4237 		    if (evaluate)
4238 		    {
4239 			rettv->v_type = VAR_NUMBER;
4240 			rettv->vval.v_number = n;
4241 		    }
4242 		}
4243 		break;
4244 	}
4245 
4246     /*
4247      * String constant: "string".
4248      */
4249     case '"':	ret = get_string_tv(arg, rettv, evaluate);
4250 		break;
4251 
4252     /*
4253      * Literal string constant: 'str''ing'.
4254      */
4255     case '\'':	ret = get_lit_string_tv(arg, rettv, evaluate);
4256 		break;
4257 
4258     /*
4259      * List: [expr, expr]
4260      */
4261     case '[':	ret = get_list_tv(arg, rettv, evaluate);
4262 		break;
4263 
4264     /*
4265      * Lambda: {arg, arg -> expr}
4266      * Dictionary: {key: val, key: val}
4267      */
4268     case '{':	ret = get_lambda_tv(arg, rettv, evaluate);
4269 		if (ret == NOTDONE)
4270 		    ret = get_dict_tv(arg, rettv, evaluate);
4271 		break;
4272 
4273     /*
4274      * Option value: &name
4275      */
4276     case '&':	ret = get_option_tv(arg, rettv, evaluate);
4277 		break;
4278 
4279     /*
4280      * Environment variable: $VAR.
4281      */
4282     case '$':	ret = get_env_tv(arg, rettv, evaluate);
4283 		break;
4284 
4285     /*
4286      * Register contents: @r.
4287      */
4288     case '@':	++*arg;
4289 		if (evaluate)
4290 		{
4291 		    rettv->v_type = VAR_STRING;
4292 		    rettv->vval.v_string = get_reg_contents(**arg,
4293 							    GREG_EXPR_SRC);
4294 		}
4295 		if (**arg != NUL)
4296 		    ++*arg;
4297 		break;
4298 
4299     /*
4300      * nested expression: (expression).
4301      */
4302     case '(':	*arg = skipwhite(*arg + 1);
4303 		ret = eval1(arg, rettv, evaluate);	/* recursive! */
4304 		if (**arg == ')')
4305 		    ++*arg;
4306 		else if (ret == OK)
4307 		{
4308 		    EMSG(_("E110: Missing ')'"));
4309 		    clear_tv(rettv);
4310 		    ret = FAIL;
4311 		}
4312 		break;
4313 
4314     default:	ret = NOTDONE;
4315 		break;
4316     }
4317 
4318     if (ret == NOTDONE)
4319     {
4320 	/*
4321 	 * Must be a variable or function name.
4322 	 * Can also be a curly-braces kind of name: {expr}.
4323 	 */
4324 	s = *arg;
4325 	len = get_name_len(arg, &alias, evaluate, TRUE);
4326 	if (alias != NULL)
4327 	    s = alias;
4328 
4329 	if (len <= 0)
4330 	    ret = FAIL;
4331 	else
4332 	{
4333 	    if (**arg == '(')		/* recursive! */
4334 	    {
4335 		partial_T *partial;
4336 
4337 		if (!evaluate)
4338 		    check_vars(s, len);
4339 
4340 		/* If "s" is the name of a variable of type VAR_FUNC
4341 		 * use its contents. */
4342 		s = deref_func_name(s, &len, &partial, !evaluate);
4343 
4344 		/* Invoke the function. */
4345 		ret = get_func_tv(s, len, rettv, arg,
4346 			  curwin->w_cursor.lnum, curwin->w_cursor.lnum,
4347 			  &len, evaluate, partial, NULL);
4348 
4349 		/* If evaluate is FALSE rettv->v_type was not set in
4350 		 * get_func_tv, but it's needed in handle_subscript() to parse
4351 		 * what follows. So set it here. */
4352 		if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
4353 		{
4354 		    rettv->vval.v_string = NULL;
4355 		    rettv->v_type = VAR_FUNC;
4356 		}
4357 
4358 		/* Stop the expression evaluation when immediately
4359 		 * aborting on error, or when an interrupt occurred or
4360 		 * an exception was thrown but not caught. */
4361 		if (aborting())
4362 		{
4363 		    if (ret == OK)
4364 			clear_tv(rettv);
4365 		    ret = FAIL;
4366 		}
4367 	    }
4368 	    else if (evaluate)
4369 		ret = get_var_tv(s, len, rettv, NULL, TRUE, FALSE);
4370 	    else
4371 	    {
4372 		check_vars(s, len);
4373 		ret = OK;
4374 	    }
4375 	}
4376 	vim_free(alias);
4377     }
4378 
4379     *arg = skipwhite(*arg);
4380 
4381     /* Handle following '[', '(' and '.' for expr[expr], expr.name,
4382      * expr(expr). */
4383     if (ret == OK)
4384 	ret = handle_subscript(arg, rettv, evaluate, TRUE);
4385 
4386     /*
4387      * Apply logical NOT and unary '-', from right to left, ignore '+'.
4388      */
4389     if (ret == OK && evaluate && end_leader > start_leader)
4390     {
4391 	int	    error = FALSE;
4392 	varnumber_T val = 0;
4393 #ifdef FEAT_FLOAT
4394 	float_T	    f = 0.0;
4395 
4396 	if (rettv->v_type == VAR_FLOAT)
4397 	    f = rettv->vval.v_float;
4398 	else
4399 #endif
4400 	    val = get_tv_number_chk(rettv, &error);
4401 	if (error)
4402 	{
4403 	    clear_tv(rettv);
4404 	    ret = FAIL;
4405 	}
4406 	else
4407 	{
4408 	    while (end_leader > start_leader)
4409 	    {
4410 		--end_leader;
4411 		if (*end_leader == '!')
4412 		{
4413 #ifdef FEAT_FLOAT
4414 		    if (rettv->v_type == VAR_FLOAT)
4415 			f = !f;
4416 		    else
4417 #endif
4418 			val = !val;
4419 		}
4420 		else if (*end_leader == '-')
4421 		{
4422 #ifdef FEAT_FLOAT
4423 		    if (rettv->v_type == VAR_FLOAT)
4424 			f = -f;
4425 		    else
4426 #endif
4427 			val = -val;
4428 		}
4429 	    }
4430 #ifdef FEAT_FLOAT
4431 	    if (rettv->v_type == VAR_FLOAT)
4432 	    {
4433 		clear_tv(rettv);
4434 		rettv->vval.v_float = f;
4435 	    }
4436 	    else
4437 #endif
4438 	    {
4439 		clear_tv(rettv);
4440 		rettv->v_type = VAR_NUMBER;
4441 		rettv->vval.v_number = val;
4442 	    }
4443 	}
4444     }
4445 
4446     return ret;
4447 }
4448 
4449 /*
4450  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
4451  * "*arg" points to the '[' or '.'.
4452  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
4453  */
4454     static int
4455 eval_index(
4456     char_u	**arg,
4457     typval_T	*rettv,
4458     int		evaluate,
4459     int		verbose)	/* give error messages */
4460 {
4461     int		empty1 = FALSE, empty2 = FALSE;
4462     typval_T	var1, var2;
4463     long	n1, n2 = 0;
4464     long	len = -1;
4465     int		range = FALSE;
4466     char_u	*s;
4467     char_u	*key = NULL;
4468 
4469     switch (rettv->v_type)
4470     {
4471 	case VAR_FUNC:
4472 	case VAR_PARTIAL:
4473 	    if (verbose)
4474 		EMSG(_("E695: Cannot index a Funcref"));
4475 	    return FAIL;
4476 	case VAR_FLOAT:
4477 #ifdef FEAT_FLOAT
4478 	    if (verbose)
4479 		EMSG(_(e_float_as_string));
4480 	    return FAIL;
4481 #endif
4482 	case VAR_SPECIAL:
4483 	case VAR_JOB:
4484 	case VAR_CHANNEL:
4485 	    if (verbose)
4486 		EMSG(_("E909: Cannot index a special variable"));
4487 	    return FAIL;
4488 	case VAR_UNKNOWN:
4489 	    if (evaluate)
4490 		return FAIL;
4491 	    /* FALLTHROUGH */
4492 
4493 	case VAR_STRING:
4494 	case VAR_NUMBER:
4495 	case VAR_LIST:
4496 	case VAR_DICT:
4497 	    break;
4498     }
4499 
4500     init_tv(&var1);
4501     init_tv(&var2);
4502     if (**arg == '.')
4503     {
4504 	/*
4505 	 * dict.name
4506 	 */
4507 	key = *arg + 1;
4508 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
4509 	    ;
4510 	if (len == 0)
4511 	    return FAIL;
4512 	*arg = skipwhite(key + len);
4513     }
4514     else
4515     {
4516 	/*
4517 	 * something[idx]
4518 	 *
4519 	 * Get the (first) variable from inside the [].
4520 	 */
4521 	*arg = skipwhite(*arg + 1);
4522 	if (**arg == ':')
4523 	    empty1 = TRUE;
4524 	else if (eval1(arg, &var1, evaluate) == FAIL)	/* recursive! */
4525 	    return FAIL;
4526 	else if (evaluate && get_tv_string_chk(&var1) == NULL)
4527 	{
4528 	    /* not a number or string */
4529 	    clear_tv(&var1);
4530 	    return FAIL;
4531 	}
4532 
4533 	/*
4534 	 * Get the second variable from inside the [:].
4535 	 */
4536 	if (**arg == ':')
4537 	{
4538 	    range = TRUE;
4539 	    *arg = skipwhite(*arg + 1);
4540 	    if (**arg == ']')
4541 		empty2 = TRUE;
4542 	    else if (eval1(arg, &var2, evaluate) == FAIL)	/* recursive! */
4543 	    {
4544 		if (!empty1)
4545 		    clear_tv(&var1);
4546 		return FAIL;
4547 	    }
4548 	    else if (evaluate && get_tv_string_chk(&var2) == NULL)
4549 	    {
4550 		/* not a number or string */
4551 		if (!empty1)
4552 		    clear_tv(&var1);
4553 		clear_tv(&var2);
4554 		return FAIL;
4555 	    }
4556 	}
4557 
4558 	/* Check for the ']'. */
4559 	if (**arg != ']')
4560 	{
4561 	    if (verbose)
4562 		EMSG(_(e_missbrac));
4563 	    clear_tv(&var1);
4564 	    if (range)
4565 		clear_tv(&var2);
4566 	    return FAIL;
4567 	}
4568 	*arg = skipwhite(*arg + 1);	/* skip the ']' */
4569     }
4570 
4571     if (evaluate)
4572     {
4573 	n1 = 0;
4574 	if (!empty1 && rettv->v_type != VAR_DICT)
4575 	{
4576 	    n1 = get_tv_number(&var1);
4577 	    clear_tv(&var1);
4578 	}
4579 	if (range)
4580 	{
4581 	    if (empty2)
4582 		n2 = -1;
4583 	    else
4584 	    {
4585 		n2 = get_tv_number(&var2);
4586 		clear_tv(&var2);
4587 	    }
4588 	}
4589 
4590 	switch (rettv->v_type)
4591 	{
4592 	    case VAR_UNKNOWN:
4593 	    case VAR_FUNC:
4594 	    case VAR_PARTIAL:
4595 	    case VAR_FLOAT:
4596 	    case VAR_SPECIAL:
4597 	    case VAR_JOB:
4598 	    case VAR_CHANNEL:
4599 		break; /* not evaluating, skipping over subscript */
4600 
4601 	    case VAR_NUMBER:
4602 	    case VAR_STRING:
4603 		s = get_tv_string(rettv);
4604 		len = (long)STRLEN(s);
4605 		if (range)
4606 		{
4607 		    /* The resulting variable is a substring.  If the indexes
4608 		     * are out of range the result is empty. */
4609 		    if (n1 < 0)
4610 		    {
4611 			n1 = len + n1;
4612 			if (n1 < 0)
4613 			    n1 = 0;
4614 		    }
4615 		    if (n2 < 0)
4616 			n2 = len + n2;
4617 		    else if (n2 >= len)
4618 			n2 = len;
4619 		    if (n1 >= len || n2 < 0 || n1 > n2)
4620 			s = NULL;
4621 		    else
4622 			s = vim_strnsave(s + n1, (int)(n2 - n1 + 1));
4623 		}
4624 		else
4625 		{
4626 		    /* The resulting variable is a string of a single
4627 		     * character.  If the index is too big or negative the
4628 		     * result is empty. */
4629 		    if (n1 >= len || n1 < 0)
4630 			s = NULL;
4631 		    else
4632 			s = vim_strnsave(s + n1, 1);
4633 		}
4634 		clear_tv(rettv);
4635 		rettv->v_type = VAR_STRING;
4636 		rettv->vval.v_string = s;
4637 		break;
4638 
4639 	    case VAR_LIST:
4640 		len = list_len(rettv->vval.v_list);
4641 		if (n1 < 0)
4642 		    n1 = len + n1;
4643 		if (!empty1 && (n1 < 0 || n1 >= len))
4644 		{
4645 		    /* For a range we allow invalid values and return an empty
4646 		     * list.  A list index out of range is an error. */
4647 		    if (!range)
4648 		    {
4649 			if (verbose)
4650 			    EMSGN(_(e_listidx), n1);
4651 			return FAIL;
4652 		    }
4653 		    n1 = len;
4654 		}
4655 		if (range)
4656 		{
4657 		    list_T	*l;
4658 		    listitem_T	*item;
4659 
4660 		    if (n2 < 0)
4661 			n2 = len + n2;
4662 		    else if (n2 >= len)
4663 			n2 = len - 1;
4664 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
4665 			n2 = -1;
4666 		    l = list_alloc();
4667 		    if (l == NULL)
4668 			return FAIL;
4669 		    for (item = list_find(rettv->vval.v_list, n1);
4670 							       n1 <= n2; ++n1)
4671 		    {
4672 			if (list_append_tv(l, &item->li_tv) == FAIL)
4673 			{
4674 			    list_free(l);
4675 			    return FAIL;
4676 			}
4677 			item = item->li_next;
4678 		    }
4679 		    clear_tv(rettv);
4680 		    rettv->v_type = VAR_LIST;
4681 		    rettv->vval.v_list = l;
4682 		    ++l->lv_refcount;
4683 		}
4684 		else
4685 		{
4686 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
4687 		    clear_tv(rettv);
4688 		    *rettv = var1;
4689 		}
4690 		break;
4691 
4692 	    case VAR_DICT:
4693 		if (range)
4694 		{
4695 		    if (verbose)
4696 			EMSG(_(e_dictrange));
4697 		    if (len == -1)
4698 			clear_tv(&var1);
4699 		    return FAIL;
4700 		}
4701 		{
4702 		    dictitem_T	*item;
4703 
4704 		    if (len == -1)
4705 		    {
4706 			key = get_tv_string_chk(&var1);
4707 			if (key == NULL)
4708 			{
4709 			    clear_tv(&var1);
4710 			    return FAIL;
4711 			}
4712 		    }
4713 
4714 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
4715 
4716 		    if (item == NULL && verbose)
4717 			EMSG2(_(e_dictkey), key);
4718 		    if (len == -1)
4719 			clear_tv(&var1);
4720 		    if (item == NULL)
4721 			return FAIL;
4722 
4723 		    copy_tv(&item->di_tv, &var1);
4724 		    clear_tv(rettv);
4725 		    *rettv = var1;
4726 		}
4727 		break;
4728 	}
4729     }
4730 
4731     return OK;
4732 }
4733 
4734 /*
4735  * Get an option value.
4736  * "arg" points to the '&' or '+' before the option name.
4737  * "arg" is advanced to character after the option name.
4738  * Return OK or FAIL.
4739  */
4740     int
4741 get_option_tv(
4742     char_u	**arg,
4743     typval_T	*rettv,	/* when NULL, only check if option exists */
4744     int		evaluate)
4745 {
4746     char_u	*option_end;
4747     long	numval;
4748     char_u	*stringval;
4749     int		opt_type;
4750     int		c;
4751     int		working = (**arg == '+');    /* has("+option") */
4752     int		ret = OK;
4753     int		opt_flags;
4754 
4755     /*
4756      * Isolate the option name and find its value.
4757      */
4758     option_end = find_option_end(arg, &opt_flags);
4759     if (option_end == NULL)
4760     {
4761 	if (rettv != NULL)
4762 	    EMSG2(_("E112: Option name missing: %s"), *arg);
4763 	return FAIL;
4764     }
4765 
4766     if (!evaluate)
4767     {
4768 	*arg = option_end;
4769 	return OK;
4770     }
4771 
4772     c = *option_end;
4773     *option_end = NUL;
4774     opt_type = get_option_value(*arg, &numval,
4775 			       rettv == NULL ? NULL : &stringval, opt_flags);
4776 
4777     if (opt_type == -3)			/* invalid name */
4778     {
4779 	if (rettv != NULL)
4780 	    EMSG2(_("E113: Unknown option: %s"), *arg);
4781 	ret = FAIL;
4782     }
4783     else if (rettv != NULL)
4784     {
4785 	if (opt_type == -2)		/* hidden string option */
4786 	{
4787 	    rettv->v_type = VAR_STRING;
4788 	    rettv->vval.v_string = NULL;
4789 	}
4790 	else if (opt_type == -1)	/* hidden number option */
4791 	{
4792 	    rettv->v_type = VAR_NUMBER;
4793 	    rettv->vval.v_number = 0;
4794 	}
4795 	else if (opt_type == 1)		/* number option */
4796 	{
4797 	    rettv->v_type = VAR_NUMBER;
4798 	    rettv->vval.v_number = numval;
4799 	}
4800 	else				/* string option */
4801 	{
4802 	    rettv->v_type = VAR_STRING;
4803 	    rettv->vval.v_string = stringval;
4804 	}
4805     }
4806     else if (working && (opt_type == -2 || opt_type == -1))
4807 	ret = FAIL;
4808 
4809     *option_end = c;		    /* put back for error messages */
4810     *arg = option_end;
4811 
4812     return ret;
4813 }
4814 
4815 /*
4816  * Allocate a variable for a string constant.
4817  * Return OK or FAIL.
4818  */
4819     static int
4820 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
4821 {
4822     char_u	*p;
4823     char_u	*name;
4824     int		extra = 0;
4825 
4826     /*
4827      * Find the end of the string, skipping backslashed characters.
4828      */
4829     for (p = *arg + 1; *p != NUL && *p != '"'; mb_ptr_adv(p))
4830     {
4831 	if (*p == '\\' && p[1] != NUL)
4832 	{
4833 	    ++p;
4834 	    /* A "\<x>" form occupies at least 4 characters, and produces up
4835 	     * to 6 characters: reserve space for 2 extra */
4836 	    if (*p == '<')
4837 		extra += 2;
4838 	}
4839     }
4840 
4841     if (*p != '"')
4842     {
4843 	EMSG2(_("E114: Missing quote: %s"), *arg);
4844 	return FAIL;
4845     }
4846 
4847     /* If only parsing, set *arg and return here */
4848     if (!evaluate)
4849     {
4850 	*arg = p + 1;
4851 	return OK;
4852     }
4853 
4854     /*
4855      * Copy the string into allocated memory, handling backslashed
4856      * characters.
4857      */
4858     name = alloc((unsigned)(p - *arg + extra));
4859     if (name == NULL)
4860 	return FAIL;
4861     rettv->v_type = VAR_STRING;
4862     rettv->vval.v_string = name;
4863 
4864     for (p = *arg + 1; *p != NUL && *p != '"'; )
4865     {
4866 	if (*p == '\\')
4867 	{
4868 	    switch (*++p)
4869 	    {
4870 		case 'b': *name++ = BS; ++p; break;
4871 		case 'e': *name++ = ESC; ++p; break;
4872 		case 'f': *name++ = FF; ++p; break;
4873 		case 'n': *name++ = NL; ++p; break;
4874 		case 'r': *name++ = CAR; ++p; break;
4875 		case 't': *name++ = TAB; ++p; break;
4876 
4877 		case 'X': /* hex: "\x1", "\x12" */
4878 		case 'x':
4879 		case 'u': /* Unicode: "\u0023" */
4880 		case 'U':
4881 			  if (vim_isxdigit(p[1]))
4882 			  {
4883 			      int	n, nr;
4884 			      int	c = toupper(*p);
4885 
4886 			      if (c == 'X')
4887 				  n = 2;
4888 			      else if (*p == 'u')
4889 				  n = 4;
4890 			      else
4891 				  n = 8;
4892 			      nr = 0;
4893 			      while (--n >= 0 && vim_isxdigit(p[1]))
4894 			      {
4895 				  ++p;
4896 				  nr = (nr << 4) + hex2nr(*p);
4897 			      }
4898 			      ++p;
4899 #ifdef FEAT_MBYTE
4900 			      /* For "\u" store the number according to
4901 			       * 'encoding'. */
4902 			      if (c != 'X')
4903 				  name += (*mb_char2bytes)(nr, name);
4904 			      else
4905 #endif
4906 				  *name++ = nr;
4907 			  }
4908 			  break;
4909 
4910 			  /* octal: "\1", "\12", "\123" */
4911 		case '0':
4912 		case '1':
4913 		case '2':
4914 		case '3':
4915 		case '4':
4916 		case '5':
4917 		case '6':
4918 		case '7': *name = *p++ - '0';
4919 			  if (*p >= '0' && *p <= '7')
4920 			  {
4921 			      *name = (*name << 3) + *p++ - '0';
4922 			      if (*p >= '0' && *p <= '7')
4923 				  *name = (*name << 3) + *p++ - '0';
4924 			  }
4925 			  ++name;
4926 			  break;
4927 
4928 			    /* Special key, e.g.: "\<C-W>" */
4929 		case '<': extra = trans_special(&p, name, TRUE);
4930 			  if (extra != 0)
4931 			  {
4932 			      name += extra;
4933 			      break;
4934 			  }
4935 			  /* FALLTHROUGH */
4936 
4937 		default:  MB_COPY_CHAR(p, name);
4938 			  break;
4939 	    }
4940 	}
4941 	else
4942 	    MB_COPY_CHAR(p, name);
4943 
4944     }
4945     *name = NUL;
4946     *arg = p + 1;
4947 
4948     return OK;
4949 }
4950 
4951 /*
4952  * Allocate a variable for a 'str''ing' constant.
4953  * Return OK or FAIL.
4954  */
4955     static int
4956 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
4957 {
4958     char_u	*p;
4959     char_u	*str;
4960     int		reduce = 0;
4961 
4962     /*
4963      * Find the end of the string, skipping ''.
4964      */
4965     for (p = *arg + 1; *p != NUL; mb_ptr_adv(p))
4966     {
4967 	if (*p == '\'')
4968 	{
4969 	    if (p[1] != '\'')
4970 		break;
4971 	    ++reduce;
4972 	    ++p;
4973 	}
4974     }
4975 
4976     if (*p != '\'')
4977     {
4978 	EMSG2(_("E115: Missing quote: %s"), *arg);
4979 	return FAIL;
4980     }
4981 
4982     /* If only parsing return after setting "*arg" */
4983     if (!evaluate)
4984     {
4985 	*arg = p + 1;
4986 	return OK;
4987     }
4988 
4989     /*
4990      * Copy the string into allocated memory, handling '' to ' reduction.
4991      */
4992     str = alloc((unsigned)((p - *arg) - reduce));
4993     if (str == NULL)
4994 	return FAIL;
4995     rettv->v_type = VAR_STRING;
4996     rettv->vval.v_string = str;
4997 
4998     for (p = *arg + 1; *p != NUL; )
4999     {
5000 	if (*p == '\'')
5001 	{
5002 	    if (p[1] != '\'')
5003 		break;
5004 	    ++p;
5005 	}
5006 	MB_COPY_CHAR(p, str);
5007     }
5008     *str = NUL;
5009     *arg = p + 1;
5010 
5011     return OK;
5012 }
5013 
5014     static void
5015 partial_free(partial_T *pt)
5016 {
5017     int i;
5018 
5019     for (i = 0; i < pt->pt_argc; ++i)
5020 	clear_tv(&pt->pt_argv[i]);
5021     vim_free(pt->pt_argv);
5022     dict_unref(pt->pt_dict);
5023     func_unref(pt->pt_name);
5024     vim_free(pt->pt_name);
5025     vim_free(pt);
5026 }
5027 
5028 /*
5029  * Unreference a closure: decrement the reference count and free it when it
5030  * becomes zero.
5031  */
5032     void
5033 partial_unref(partial_T *pt)
5034 {
5035     if (pt != NULL && --pt->pt_refcount <= 0)
5036 	partial_free(pt);
5037 }
5038 
5039 static int tv_equal_recurse_limit;
5040 
5041     static int
5042 func_equal(
5043     typval_T *tv1,
5044     typval_T *tv2,
5045     int	     ic)	    /* ignore case */
5046 {
5047     char_u	*s1, *s2;
5048     dict_T	*d1, *d2;
5049     int		a1, a2;
5050     int		i;
5051 
5052     /* empty and NULL function name considered the same */
5053     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
5054 					   : tv1->vval.v_partial->pt_name;
5055     if (s1 != NULL && *s1 == NUL)
5056 	s1 = NULL;
5057     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
5058 					   : tv2->vval.v_partial->pt_name;
5059     if (s2 != NULL && *s2 == NUL)
5060 	s2 = NULL;
5061     if (s1 == NULL || s2 == NULL)
5062     {
5063 	if (s1 != s2)
5064 	    return FALSE;
5065     }
5066     else if (STRCMP(s1, s2) != 0)
5067 	return FALSE;
5068 
5069     /* empty dict and NULL dict is different */
5070     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
5071     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
5072     if (d1 == NULL || d2 == NULL)
5073     {
5074 	if (d1 != d2)
5075 	    return FALSE;
5076     }
5077     else if (!dict_equal(d1, d2, ic, TRUE))
5078 	return FALSE;
5079 
5080     /* empty list and no list considered the same */
5081     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
5082     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
5083     if (a1 != a2)
5084 	return FALSE;
5085     for (i = 0; i < a1; ++i)
5086 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
5087 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
5088 	    return FALSE;
5089 
5090     return TRUE;
5091 }
5092 
5093 /*
5094  * Return TRUE if "tv1" and "tv2" have the same value.
5095  * Compares the items just like "==" would compare them, but strings and
5096  * numbers are different.  Floats and numbers are also different.
5097  */
5098     int
5099 tv_equal(
5100     typval_T *tv1,
5101     typval_T *tv2,
5102     int	     ic,	    /* ignore case */
5103     int	     recursive)	    /* TRUE when used recursively */
5104 {
5105     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
5106     char_u	*s1, *s2;
5107     static int  recursive_cnt = 0;	    /* catch recursive loops */
5108     int		r;
5109 
5110     /* Catch lists and dicts that have an endless loop by limiting
5111      * recursiveness to a limit.  We guess they are equal then.
5112      * A fixed limit has the problem of still taking an awful long time.
5113      * Reduce the limit every time running into it. That should work fine for
5114      * deeply linked structures that are not recursively linked and catch
5115      * recursiveness quickly. */
5116     if (!recursive)
5117 	tv_equal_recurse_limit = 1000;
5118     if (recursive_cnt >= tv_equal_recurse_limit)
5119     {
5120 	--tv_equal_recurse_limit;
5121 	return TRUE;
5122     }
5123 
5124     /* For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
5125      * arguments. */
5126     if ((tv1->v_type == VAR_FUNC
5127 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
5128 	    && (tv2->v_type == VAR_FUNC
5129 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
5130     {
5131 	++recursive_cnt;
5132 	r = func_equal(tv1, tv2, ic);
5133 	--recursive_cnt;
5134 	return r;
5135     }
5136 
5137     if (tv1->v_type != tv2->v_type)
5138 	return FALSE;
5139 
5140     switch (tv1->v_type)
5141     {
5142 	case VAR_LIST:
5143 	    ++recursive_cnt;
5144 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
5145 	    --recursive_cnt;
5146 	    return r;
5147 
5148 	case VAR_DICT:
5149 	    ++recursive_cnt;
5150 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
5151 	    --recursive_cnt;
5152 	    return r;
5153 
5154 	case VAR_NUMBER:
5155 	    return tv1->vval.v_number == tv2->vval.v_number;
5156 
5157 	case VAR_STRING:
5158 	    s1 = get_tv_string_buf(tv1, buf1);
5159 	    s2 = get_tv_string_buf(tv2, buf2);
5160 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
5161 
5162 	case VAR_SPECIAL:
5163 	    return tv1->vval.v_number == tv2->vval.v_number;
5164 
5165 	case VAR_FLOAT:
5166 #ifdef FEAT_FLOAT
5167 	    return tv1->vval.v_float == tv2->vval.v_float;
5168 #endif
5169 	case VAR_JOB:
5170 #ifdef FEAT_JOB_CHANNEL
5171 	    return tv1->vval.v_job == tv2->vval.v_job;
5172 #endif
5173 	case VAR_CHANNEL:
5174 #ifdef FEAT_JOB_CHANNEL
5175 	    return tv1->vval.v_channel == tv2->vval.v_channel;
5176 #endif
5177 	case VAR_FUNC:
5178 	case VAR_PARTIAL:
5179 	case VAR_UNKNOWN:
5180 	    break;
5181     }
5182 
5183     /* VAR_UNKNOWN can be the result of a invalid expression, let's say it
5184      * does not equal anything, not even itself. */
5185     return FALSE;
5186 }
5187 
5188 /*
5189  * Return the next (unique) copy ID.
5190  * Used for serializing nested structures.
5191  */
5192     int
5193 get_copyID(void)
5194 {
5195     current_copyID += COPYID_INC;
5196     return current_copyID;
5197 }
5198 
5199 /*
5200  * Garbage collection for lists and dictionaries.
5201  *
5202  * We use reference counts to be able to free most items right away when they
5203  * are no longer used.  But for composite items it's possible that it becomes
5204  * unused while the reference count is > 0: When there is a recursive
5205  * reference.  Example:
5206  *	:let l = [1, 2, 3]
5207  *	:let d = {9: l}
5208  *	:let l[1] = d
5209  *
5210  * Since this is quite unusual we handle this with garbage collection: every
5211  * once in a while find out which lists and dicts are not referenced from any
5212  * variable.
5213  *
5214  * Here is a good reference text about garbage collection (refers to Python
5215  * but it applies to all reference-counting mechanisms):
5216  *	http://python.ca/nas/python/gc/
5217  */
5218 
5219 /*
5220  * Do garbage collection for lists and dicts.
5221  * When "testing" is TRUE this is called from test_garbagecollect_now().
5222  * Return TRUE if some memory was freed.
5223  */
5224     int
5225 garbage_collect(int testing)
5226 {
5227     int		copyID;
5228     int		abort = FALSE;
5229     buf_T	*buf;
5230     win_T	*wp;
5231     int		i;
5232     int		did_free = FALSE;
5233 #ifdef FEAT_WINDOWS
5234     tabpage_T	*tp;
5235 #endif
5236 
5237     if (!testing)
5238     {
5239 	/* Only do this once. */
5240 	want_garbage_collect = FALSE;
5241 	may_garbage_collect = FALSE;
5242 	garbage_collect_at_exit = FALSE;
5243     }
5244 
5245     /* We advance by two because we add one for items referenced through
5246      * previous_funccal. */
5247     copyID = get_copyID();
5248 
5249     /*
5250      * 1. Go through all accessible variables and mark all lists and dicts
5251      *    with copyID.
5252      */
5253 
5254     /* Don't free variables in the previous_funccal list unless they are only
5255      * referenced through previous_funccal.  This must be first, because if
5256      * the item is referenced elsewhere the funccal must not be freed. */
5257     abort = abort || set_ref_in_previous_funccal(copyID);
5258 
5259     /* script-local variables */
5260     for (i = 1; i <= ga_scripts.ga_len; ++i)
5261 	abort = abort || set_ref_in_ht(&SCRIPT_VARS(i), copyID, NULL);
5262 
5263     /* buffer-local variables */
5264     FOR_ALL_BUFFERS(buf)
5265 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
5266 								  NULL, NULL);
5267 
5268     /* window-local variables */
5269     FOR_ALL_TAB_WINDOWS(tp, wp)
5270 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
5271 								  NULL, NULL);
5272 #ifdef FEAT_AUTOCMD
5273     if (aucmd_win != NULL)
5274 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
5275 								  NULL, NULL);
5276 #endif
5277 
5278 #ifdef FEAT_WINDOWS
5279     /* tabpage-local variables */
5280     FOR_ALL_TABPAGES(tp)
5281 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
5282 								  NULL, NULL);
5283 #endif
5284 
5285     /* global variables */
5286     abort = abort || set_ref_in_ht(&globvarht, copyID, NULL);
5287 
5288     /* function-local variables */
5289     abort = abort || set_ref_in_call_stack(copyID);
5290 
5291     /* function call arguments, if v:testing is set. */
5292     abort = abort || set_ref_in_func_args(copyID);
5293 
5294     /* v: vars */
5295     abort = abort || set_ref_in_ht(&vimvarht, copyID, NULL);
5296 
5297 #ifdef FEAT_LUA
5298     abort = abort || set_ref_in_lua(copyID);
5299 #endif
5300 
5301 #ifdef FEAT_PYTHON
5302     abort = abort || set_ref_in_python(copyID);
5303 #endif
5304 
5305 #ifdef FEAT_PYTHON3
5306     abort = abort || set_ref_in_python3(copyID);
5307 #endif
5308 
5309 #ifdef FEAT_JOB_CHANNEL
5310     abort = abort || set_ref_in_channel(copyID);
5311     abort = abort || set_ref_in_job(copyID);
5312 #endif
5313 #ifdef FEAT_NETBEANS_INTG
5314     abort = abort || set_ref_in_nb_channel(copyID);
5315 #endif
5316 
5317 #ifdef FEAT_TIMERS
5318     abort = abort || set_ref_in_timer(copyID);
5319 #endif
5320 
5321     if (!abort)
5322     {
5323 	/*
5324 	 * 2. Free lists and dictionaries that are not referenced.
5325 	 */
5326 	did_free = free_unref_items(copyID);
5327 
5328 	/*
5329 	 * 3. Check if any funccal can be freed now.
5330 	 *    This may call us back recursively.
5331 	 */
5332 	free_unref_funccal(copyID, testing);
5333     }
5334     else if (p_verbose > 0)
5335     {
5336 	verb_msg((char_u *)_("Not enough memory to set references, garbage collection aborted!"));
5337     }
5338 
5339     return did_free;
5340 }
5341 
5342 /*
5343  * Free lists, dictionaries, channels and jobs that are no longer referenced.
5344  */
5345     static int
5346 free_unref_items(int copyID)
5347 {
5348     int		did_free = FALSE;
5349 
5350     /* Let all "free" functions know that we are here.  This means no
5351      * dictionaries, lists, channels or jobs are to be freed, because we will
5352      * do that here. */
5353     in_free_unref_items = TRUE;
5354 
5355     /*
5356      * PASS 1: free the contents of the items.  We don't free the items
5357      * themselves yet, so that it is possible to decrement refcount counters
5358      */
5359 
5360     /* Go through the list of dicts and free items without the copyID. */
5361     did_free |= dict_free_nonref(copyID);
5362 
5363     /* Go through the list of lists and free items without the copyID. */
5364     did_free |= list_free_nonref(copyID);
5365 
5366 #ifdef FEAT_JOB_CHANNEL
5367     /* Go through the list of jobs and free items without the copyID. This
5368      * must happen before doing channels, because jobs refer to channels, but
5369      * the reference from the channel to the job isn't tracked. */
5370     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
5371 
5372     /* Go through the list of channels and free items without the copyID.  */
5373     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
5374 #endif
5375 
5376     /*
5377      * PASS 2: free the items themselves.
5378      */
5379     dict_free_items(copyID);
5380     list_free_items(copyID);
5381 
5382 #ifdef FEAT_JOB_CHANNEL
5383     /* Go through the list of jobs and free items without the copyID. This
5384      * must happen before doing channels, because jobs refer to channels, but
5385      * the reference from the channel to the job isn't tracked. */
5386     free_unused_jobs(copyID, COPYID_MASK);
5387 
5388     /* Go through the list of channels and free items without the copyID.  */
5389     free_unused_channels(copyID, COPYID_MASK);
5390 #endif
5391 
5392     in_free_unref_items = FALSE;
5393 
5394     return did_free;
5395 }
5396 
5397 /*
5398  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
5399  * "list_stack" is used to add lists to be marked.  Can be NULL.
5400  *
5401  * Returns TRUE if setting references failed somehow.
5402  */
5403     int
5404 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
5405 {
5406     int		todo;
5407     int		abort = FALSE;
5408     hashitem_T	*hi;
5409     hashtab_T	*cur_ht;
5410     ht_stack_T	*ht_stack = NULL;
5411     ht_stack_T	*tempitem;
5412 
5413     cur_ht = ht;
5414     for (;;)
5415     {
5416 	if (!abort)
5417 	{
5418 	    /* Mark each item in the hashtab.  If the item contains a hashtab
5419 	     * it is added to ht_stack, if it contains a list it is added to
5420 	     * list_stack. */
5421 	    todo = (int)cur_ht->ht_used;
5422 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
5423 		if (!HASHITEM_EMPTY(hi))
5424 		{
5425 		    --todo;
5426 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
5427 						       &ht_stack, list_stack);
5428 		}
5429 	}
5430 
5431 	if (ht_stack == NULL)
5432 	    break;
5433 
5434 	/* take an item from the stack */
5435 	cur_ht = ht_stack->ht;
5436 	tempitem = ht_stack;
5437 	ht_stack = ht_stack->prev;
5438 	free(tempitem);
5439     }
5440 
5441     return abort;
5442 }
5443 
5444 /*
5445  * Mark all lists and dicts referenced through list "l" with "copyID".
5446  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5447  *
5448  * Returns TRUE if setting references failed somehow.
5449  */
5450     int
5451 set_ref_in_list(list_T *l, int copyID, ht_stack_T **ht_stack)
5452 {
5453     listitem_T	 *li;
5454     int		 abort = FALSE;
5455     list_T	 *cur_l;
5456     list_stack_T *list_stack = NULL;
5457     list_stack_T *tempitem;
5458 
5459     cur_l = l;
5460     for (;;)
5461     {
5462 	if (!abort)
5463 	    /* Mark each item in the list.  If the item contains a hashtab
5464 	     * it is added to ht_stack, if it contains a list it is added to
5465 	     * list_stack. */
5466 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
5467 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
5468 						       ht_stack, &list_stack);
5469 	if (list_stack == NULL)
5470 	    break;
5471 
5472 	/* take an item from the stack */
5473 	cur_l = list_stack->list;
5474 	tempitem = list_stack;
5475 	list_stack = list_stack->prev;
5476 	free(tempitem);
5477     }
5478 
5479     return abort;
5480 }
5481 
5482 /*
5483  * Mark all lists and dicts referenced through typval "tv" with "copyID".
5484  * "list_stack" is used to add lists to be marked.  Can be NULL.
5485  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5486  *
5487  * Returns TRUE if setting references failed somehow.
5488  */
5489     int
5490 set_ref_in_item(
5491     typval_T	    *tv,
5492     int		    copyID,
5493     ht_stack_T	    **ht_stack,
5494     list_stack_T    **list_stack)
5495 {
5496     int		abort = FALSE;
5497 
5498     if (tv->v_type == VAR_DICT)
5499     {
5500 	dict_T	*dd = tv->vval.v_dict;
5501 
5502 	if (dd != NULL && dd->dv_copyID != copyID)
5503 	{
5504 	    /* Didn't see this dict yet. */
5505 	    dd->dv_copyID = copyID;
5506 	    if (ht_stack == NULL)
5507 	    {
5508 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
5509 	    }
5510 	    else
5511 	    {
5512 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
5513 		if (newitem == NULL)
5514 		    abort = TRUE;
5515 		else
5516 		{
5517 		    newitem->ht = &dd->dv_hashtab;
5518 		    newitem->prev = *ht_stack;
5519 		    *ht_stack = newitem;
5520 		}
5521 	    }
5522 	}
5523     }
5524     else if (tv->v_type == VAR_LIST)
5525     {
5526 	list_T	*ll = tv->vval.v_list;
5527 
5528 	if (ll != NULL && ll->lv_copyID != copyID)
5529 	{
5530 	    /* Didn't see this list yet. */
5531 	    ll->lv_copyID = copyID;
5532 	    if (list_stack == NULL)
5533 	    {
5534 		abort = set_ref_in_list(ll, copyID, ht_stack);
5535 	    }
5536 	    else
5537 	    {
5538 		list_stack_T *newitem = (list_stack_T*)malloc(
5539 							sizeof(list_stack_T));
5540 		if (newitem == NULL)
5541 		    abort = TRUE;
5542 		else
5543 		{
5544 		    newitem->list = ll;
5545 		    newitem->prev = *list_stack;
5546 		    *list_stack = newitem;
5547 		}
5548 	    }
5549 	}
5550     }
5551     else if (tv->v_type == VAR_FUNC)
5552     {
5553 	abort = set_ref_in_func(tv->vval.v_string, copyID);
5554     }
5555     else if (tv->v_type == VAR_PARTIAL)
5556     {
5557 	partial_T	*pt = tv->vval.v_partial;
5558 	int		i;
5559 
5560 	/* A partial does not have a copyID, because it cannot contain itself.
5561 	 */
5562 	if (pt != NULL)
5563 	{
5564 	    abort = set_ref_in_func(pt->pt_name, copyID);
5565 
5566 	    if (pt->pt_dict != NULL)
5567 	    {
5568 		typval_T dtv;
5569 
5570 		dtv.v_type = VAR_DICT;
5571 		dtv.vval.v_dict = pt->pt_dict;
5572 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5573 	    }
5574 
5575 	    for (i = 0; i < pt->pt_argc; ++i)
5576 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
5577 							ht_stack, list_stack);
5578 	}
5579     }
5580 #ifdef FEAT_JOB_CHANNEL
5581     else if (tv->v_type == VAR_JOB)
5582     {
5583 	job_T	    *job = tv->vval.v_job;
5584 	typval_T    dtv;
5585 
5586 	if (job != NULL && job->jv_copyID != copyID)
5587 	{
5588 	    job->jv_copyID = copyID;
5589 	    if (job->jv_channel != NULL)
5590 	    {
5591 		dtv.v_type = VAR_CHANNEL;
5592 		dtv.vval.v_channel = job->jv_channel;
5593 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5594 	    }
5595 	    if (job->jv_exit_partial != NULL)
5596 	    {
5597 		dtv.v_type = VAR_PARTIAL;
5598 		dtv.vval.v_partial = job->jv_exit_partial;
5599 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5600 	    }
5601 	}
5602     }
5603     else if (tv->v_type == VAR_CHANNEL)
5604     {
5605 	channel_T   *ch =tv->vval.v_channel;
5606 	int	    part;
5607 	typval_T    dtv;
5608 	jsonq_T	    *jq;
5609 	cbq_T	    *cq;
5610 
5611 	if (ch != NULL && ch->ch_copyID != copyID)
5612 	{
5613 	    ch->ch_copyID = copyID;
5614 	    for (part = PART_SOCK; part <= PART_IN; ++part)
5615 	    {
5616 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
5617 							     jq = jq->jq_next)
5618 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
5619 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
5620 							     cq = cq->cq_next)
5621 		    if (cq->cq_partial != NULL)
5622 		    {
5623 			dtv.v_type = VAR_PARTIAL;
5624 			dtv.vval.v_partial = cq->cq_partial;
5625 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5626 		    }
5627 		if (ch->ch_part[part].ch_partial != NULL)
5628 		{
5629 		    dtv.v_type = VAR_PARTIAL;
5630 		    dtv.vval.v_partial = ch->ch_part[part].ch_partial;
5631 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5632 		}
5633 	    }
5634 	    if (ch->ch_partial != NULL)
5635 	    {
5636 		dtv.v_type = VAR_PARTIAL;
5637 		dtv.vval.v_partial = ch->ch_partial;
5638 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5639 	    }
5640 	    if (ch->ch_close_partial != NULL)
5641 	    {
5642 		dtv.v_type = VAR_PARTIAL;
5643 		dtv.vval.v_partial = ch->ch_close_partial;
5644 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5645 	    }
5646 	}
5647     }
5648 #endif
5649     return abort;
5650 }
5651 
5652     static char *
5653 get_var_special_name(int nr)
5654 {
5655     switch (nr)
5656     {
5657 	case VVAL_FALSE: return "v:false";
5658 	case VVAL_TRUE:  return "v:true";
5659 	case VVAL_NONE:  return "v:none";
5660 	case VVAL_NULL:  return "v:null";
5661     }
5662     EMSG2(_(e_intern2), "get_var_special_name()");
5663     return "42";
5664 }
5665 
5666 /*
5667  * Return a string with the string representation of a variable.
5668  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5669  * "numbuf" is used for a number.
5670  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5671  * When both "echo_style" and "dict_val" are FALSE, put quotes around stings as
5672  * "string()", otherwise does not put quotes around strings, as ":echo"
5673  * displays values.
5674  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
5675  * are replaced with "...".
5676  * May return NULL.
5677  */
5678     char_u *
5679 echo_string_core(
5680     typval_T	*tv,
5681     char_u	**tofree,
5682     char_u	*numbuf,
5683     int		copyID,
5684     int		echo_style,
5685     int		restore_copyID,
5686     int		dict_val)
5687 {
5688     static int	recurse = 0;
5689     char_u	*r = NULL;
5690 
5691     if (recurse >= DICT_MAXNEST)
5692     {
5693 	if (!did_echo_string_emsg)
5694 	{
5695 	    /* Only give this message once for a recursive call to avoid
5696 	     * flooding the user with errors.  And stop iterating over lists
5697 	     * and dicts. */
5698 	    did_echo_string_emsg = TRUE;
5699 	    EMSG(_("E724: variable nested too deep for displaying"));
5700 	}
5701 	*tofree = NULL;
5702 	return (char_u *)"{E724}";
5703     }
5704     ++recurse;
5705 
5706     switch (tv->v_type)
5707     {
5708 	case VAR_STRING:
5709 	    if (echo_style && !dict_val)
5710 	    {
5711 		*tofree = NULL;
5712 		r = get_tv_string_buf(tv, numbuf);
5713 	    }
5714 	    else
5715 	    {
5716 		*tofree = string_quote(tv->vval.v_string, FALSE);
5717 		r = *tofree;
5718 	    }
5719 	    break;
5720 
5721 	case VAR_FUNC:
5722 	    if (echo_style)
5723 	    {
5724 		*tofree = NULL;
5725 		r = tv->vval.v_string;
5726 	    }
5727 	    else
5728 	    {
5729 		*tofree = string_quote(tv->vval.v_string, TRUE);
5730 		r = *tofree;
5731 	    }
5732 	    break;
5733 
5734 	case VAR_PARTIAL:
5735 	    {
5736 		partial_T   *pt = tv->vval.v_partial;
5737 		char_u	    *fname = string_quote(pt == NULL ? NULL
5738 							: pt->pt_name, FALSE);
5739 		garray_T    ga;
5740 		int	    i;
5741 		char_u	    *tf;
5742 
5743 		ga_init2(&ga, 1, 100);
5744 		ga_concat(&ga, (char_u *)"function(");
5745 		if (fname != NULL)
5746 		{
5747 		    ga_concat(&ga, fname);
5748 		    vim_free(fname);
5749 		}
5750 		if (pt != NULL && pt->pt_argc > 0)
5751 		{
5752 		    ga_concat(&ga, (char_u *)", [");
5753 		    for (i = 0; i < pt->pt_argc; ++i)
5754 		    {
5755 			if (i > 0)
5756 			    ga_concat(&ga, (char_u *)", ");
5757 			ga_concat(&ga,
5758 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
5759 			vim_free(tf);
5760 		    }
5761 		    ga_concat(&ga, (char_u *)"]");
5762 		}
5763 		if (pt != NULL && pt->pt_dict != NULL)
5764 		{
5765 		    typval_T dtv;
5766 
5767 		    ga_concat(&ga, (char_u *)", ");
5768 		    dtv.v_type = VAR_DICT;
5769 		    dtv.vval.v_dict = pt->pt_dict;
5770 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
5771 		    vim_free(tf);
5772 		}
5773 		ga_concat(&ga, (char_u *)")");
5774 
5775 		*tofree = ga.ga_data;
5776 		r = *tofree;
5777 		break;
5778 	    }
5779 
5780 	case VAR_LIST:
5781 	    if (tv->vval.v_list == NULL)
5782 	    {
5783 		*tofree = NULL;
5784 		r = NULL;
5785 	    }
5786 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
5787 		    && tv->vval.v_list->lv_len > 0)
5788 	    {
5789 		*tofree = NULL;
5790 		r = (char_u *)"[...]";
5791 	    }
5792 	    else
5793 	    {
5794 		int old_copyID = tv->vval.v_list->lv_copyID;
5795 
5796 		tv->vval.v_list->lv_copyID = copyID;
5797 		*tofree = list2string(tv, copyID, restore_copyID);
5798 		if (restore_copyID)
5799 		    tv->vval.v_list->lv_copyID = old_copyID;
5800 		r = *tofree;
5801 	    }
5802 	    break;
5803 
5804 	case VAR_DICT:
5805 	    if (tv->vval.v_dict == NULL)
5806 	    {
5807 		*tofree = NULL;
5808 		r = NULL;
5809 	    }
5810 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
5811 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
5812 	    {
5813 		*tofree = NULL;
5814 		r = (char_u *)"{...}";
5815 	    }
5816 	    else
5817 	    {
5818 		int old_copyID = tv->vval.v_dict->dv_copyID;
5819 		tv->vval.v_dict->dv_copyID = copyID;
5820 		*tofree = dict2string(tv, copyID, restore_copyID);
5821 		if (restore_copyID)
5822 		    tv->vval.v_dict->dv_copyID = old_copyID;
5823 		r = *tofree;
5824 	    }
5825 	    break;
5826 
5827 	case VAR_NUMBER:
5828 	case VAR_UNKNOWN:
5829 	case VAR_JOB:
5830 	case VAR_CHANNEL:
5831 	    *tofree = NULL;
5832 	    r = get_tv_string_buf(tv, numbuf);
5833 	    break;
5834 
5835 	case VAR_FLOAT:
5836 #ifdef FEAT_FLOAT
5837 	    *tofree = NULL;
5838 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
5839 	    r = numbuf;
5840 	    break;
5841 #endif
5842 
5843 	case VAR_SPECIAL:
5844 	    *tofree = NULL;
5845 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
5846 	    break;
5847     }
5848 
5849     if (--recurse == 0)
5850 	did_echo_string_emsg = FALSE;
5851     return r;
5852 }
5853 
5854 /*
5855  * Return a string with the string representation of a variable.
5856  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5857  * "numbuf" is used for a number.
5858  * Does not put quotes around strings, as ":echo" displays values.
5859  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5860  * May return NULL.
5861  */
5862     char_u *
5863 echo_string(
5864     typval_T	*tv,
5865     char_u	**tofree,
5866     char_u	*numbuf,
5867     int		copyID)
5868 {
5869     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
5870 }
5871 
5872 /*
5873  * Return a string with the string representation of a variable.
5874  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5875  * "numbuf" is used for a number.
5876  * Puts quotes around strings, so that they can be parsed back by eval().
5877  * May return NULL.
5878  */
5879     char_u *
5880 tv2string(
5881     typval_T	*tv,
5882     char_u	**tofree,
5883     char_u	*numbuf,
5884     int		copyID)
5885 {
5886     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
5887 }
5888 
5889 /*
5890  * Return string "str" in ' quotes, doubling ' characters.
5891  * If "str" is NULL an empty string is assumed.
5892  * If "function" is TRUE make it function('string').
5893  */
5894     char_u *
5895 string_quote(char_u *str, int function)
5896 {
5897     unsigned	len;
5898     char_u	*p, *r, *s;
5899 
5900     len = (function ? 13 : 3);
5901     if (str != NULL)
5902     {
5903 	len += (unsigned)STRLEN(str);
5904 	for (p = str; *p != NUL; mb_ptr_adv(p))
5905 	    if (*p == '\'')
5906 		++len;
5907     }
5908     s = r = alloc(len);
5909     if (r != NULL)
5910     {
5911 	if (function)
5912 	{
5913 	    STRCPY(r, "function('");
5914 	    r += 10;
5915 	}
5916 	else
5917 	    *r++ = '\'';
5918 	if (str != NULL)
5919 	    for (p = str; *p != NUL; )
5920 	    {
5921 		if (*p == '\'')
5922 		    *r++ = '\'';
5923 		MB_COPY_CHAR(p, r);
5924 	    }
5925 	*r++ = '\'';
5926 	if (function)
5927 	    *r++ = ')';
5928 	*r++ = NUL;
5929     }
5930     return s;
5931 }
5932 
5933 #if defined(FEAT_FLOAT) || defined(PROTO)
5934 /*
5935  * Convert the string "text" to a floating point number.
5936  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
5937  * this always uses a decimal point.
5938  * Returns the length of the text that was consumed.
5939  */
5940     int
5941 string2float(
5942     char_u	*text,
5943     float_T	*value)	    /* result stored here */
5944 {
5945     char	*s = (char *)text;
5946     float_T	f;
5947 
5948     f = strtod(s, &s);
5949     *value = f;
5950     return (int)((char_u *)s - text);
5951 }
5952 #endif
5953 
5954 /*
5955  * Get the value of an environment variable.
5956  * "arg" is pointing to the '$'.  It is advanced to after the name.
5957  * If the environment variable was not set, silently assume it is empty.
5958  * Return FAIL if the name is invalid.
5959  */
5960     static int
5961 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
5962 {
5963     char_u	*string = NULL;
5964     int		len;
5965     int		cc;
5966     char_u	*name;
5967     int		mustfree = FALSE;
5968 
5969     ++*arg;
5970     name = *arg;
5971     len = get_env_len(arg);
5972     if (evaluate)
5973     {
5974 	if (len == 0)
5975 	    return FAIL; /* invalid empty name */
5976 
5977 	cc = name[len];
5978 	name[len] = NUL;
5979 	/* first try vim_getenv(), fast for normal environment vars */
5980 	string = vim_getenv(name, &mustfree);
5981 	if (string != NULL && *string != NUL)
5982 	{
5983 	    if (!mustfree)
5984 		string = vim_strsave(string);
5985 	}
5986 	else
5987 	{
5988 	    if (mustfree)
5989 		vim_free(string);
5990 
5991 	    /* next try expanding things like $VIM and ${HOME} */
5992 	    string = expand_env_save(name - 1);
5993 	    if (string != NULL && *string == '$')
5994 	    {
5995 		vim_free(string);
5996 		string = NULL;
5997 	    }
5998 	}
5999 	name[len] = cc;
6000 
6001 	rettv->v_type = VAR_STRING;
6002 	rettv->vval.v_string = string;
6003     }
6004 
6005     return OK;
6006 }
6007 
6008 
6009 
6010 /*
6011  * Translate a String variable into a position.
6012  * Returns NULL when there is an error.
6013  */
6014     pos_T *
6015 var2fpos(
6016     typval_T	*varp,
6017     int		dollar_lnum,	/* TRUE when $ is last line */
6018     int		*fnum)		/* set to fnum for '0, 'A, etc. */
6019 {
6020     char_u		*name;
6021     static pos_T	pos;
6022     pos_T		*pp;
6023 
6024     /* Argument can be [lnum, col, coladd]. */
6025     if (varp->v_type == VAR_LIST)
6026     {
6027 	list_T		*l;
6028 	int		len;
6029 	int		error = FALSE;
6030 	listitem_T	*li;
6031 
6032 	l = varp->vval.v_list;
6033 	if (l == NULL)
6034 	    return NULL;
6035 
6036 	/* Get the line number */
6037 	pos.lnum = list_find_nr(l, 0L, &error);
6038 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
6039 	    return NULL;	/* invalid line number */
6040 
6041 	/* Get the column number */
6042 	pos.col = list_find_nr(l, 1L, &error);
6043 	if (error)
6044 	    return NULL;
6045 	len = (long)STRLEN(ml_get(pos.lnum));
6046 
6047 	/* We accept "$" for the column number: last column. */
6048 	li = list_find(l, 1L);
6049 	if (li != NULL && li->li_tv.v_type == VAR_STRING
6050 		&& li->li_tv.vval.v_string != NULL
6051 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
6052 	    pos.col = len + 1;
6053 
6054 	/* Accept a position up to the NUL after the line. */
6055 	if (pos.col == 0 || (int)pos.col > len + 1)
6056 	    return NULL;	/* invalid column number */
6057 	--pos.col;
6058 
6059 #ifdef FEAT_VIRTUALEDIT
6060 	/* Get the virtual offset.  Defaults to zero. */
6061 	pos.coladd = list_find_nr(l, 2L, &error);
6062 	if (error)
6063 	    pos.coladd = 0;
6064 #endif
6065 
6066 	return &pos;
6067     }
6068 
6069     name = get_tv_string_chk(varp);
6070     if (name == NULL)
6071 	return NULL;
6072     if (name[0] == '.')				/* cursor */
6073 	return &curwin->w_cursor;
6074     if (name[0] == 'v' && name[1] == NUL)	/* Visual start */
6075     {
6076 	if (VIsual_active)
6077 	    return &VIsual;
6078 	return &curwin->w_cursor;
6079     }
6080     if (name[0] == '\'')			/* mark */
6081     {
6082 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
6083 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
6084 	    return NULL;
6085 	return pp;
6086     }
6087 
6088 #ifdef FEAT_VIRTUALEDIT
6089     pos.coladd = 0;
6090 #endif
6091 
6092     if (name[0] == 'w' && dollar_lnum)
6093     {
6094 	pos.col = 0;
6095 	if (name[1] == '0')		/* "w0": first visible line */
6096 	{
6097 	    update_topline();
6098 	    pos.lnum = curwin->w_topline;
6099 	    return &pos;
6100 	}
6101 	else if (name[1] == '$')	/* "w$": last visible line */
6102 	{
6103 	    validate_botline();
6104 	    pos.lnum = curwin->w_botline - 1;
6105 	    return &pos;
6106 	}
6107     }
6108     else if (name[0] == '$')		/* last column or line */
6109     {
6110 	if (dollar_lnum)
6111 	{
6112 	    pos.lnum = curbuf->b_ml.ml_line_count;
6113 	    pos.col = 0;
6114 	}
6115 	else
6116 	{
6117 	    pos.lnum = curwin->w_cursor.lnum;
6118 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
6119 	}
6120 	return &pos;
6121     }
6122     return NULL;
6123 }
6124 
6125 /*
6126  * Convert list in "arg" into a position and optional file number.
6127  * When "fnump" is NULL there is no file number, only 3 items.
6128  * Note that the column is passed on as-is, the caller may want to decrement
6129  * it to use 1 for the first column.
6130  * Return FAIL when conversion is not possible, doesn't check the position for
6131  * validity.
6132  */
6133     int
6134 list2fpos(
6135     typval_T	*arg,
6136     pos_T	*posp,
6137     int		*fnump,
6138     colnr_T	*curswantp)
6139 {
6140     list_T	*l = arg->vval.v_list;
6141     long	i = 0;
6142     long	n;
6143 
6144     /* List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
6145      * there when "fnump" isn't NULL; "coladd" and "curswant" are optional. */
6146     if (arg->v_type != VAR_LIST
6147 	    || l == NULL
6148 	    || l->lv_len < (fnump == NULL ? 2 : 3)
6149 	    || l->lv_len > (fnump == NULL ? 4 : 5))
6150 	return FAIL;
6151 
6152     if (fnump != NULL)
6153     {
6154 	n = list_find_nr(l, i++, NULL);	/* fnum */
6155 	if (n < 0)
6156 	    return FAIL;
6157 	if (n == 0)
6158 	    n = curbuf->b_fnum;		/* current buffer */
6159 	*fnump = n;
6160     }
6161 
6162     n = list_find_nr(l, i++, NULL);	/* lnum */
6163     if (n < 0)
6164 	return FAIL;
6165     posp->lnum = n;
6166 
6167     n = list_find_nr(l, i++, NULL);	/* col */
6168     if (n < 0)
6169 	return FAIL;
6170     posp->col = n;
6171 
6172 #ifdef FEAT_VIRTUALEDIT
6173     n = list_find_nr(l, i, NULL);	/* off */
6174     if (n < 0)
6175 	posp->coladd = 0;
6176     else
6177 	posp->coladd = n;
6178 #endif
6179 
6180     if (curswantp != NULL)
6181 	*curswantp = list_find_nr(l, i + 1, NULL);  /* curswant */
6182 
6183     return OK;
6184 }
6185 
6186 /*
6187  * Get the length of an environment variable name.
6188  * Advance "arg" to the first character after the name.
6189  * Return 0 for error.
6190  */
6191     static int
6192 get_env_len(char_u **arg)
6193 {
6194     char_u	*p;
6195     int		len;
6196 
6197     for (p = *arg; vim_isIDc(*p); ++p)
6198 	;
6199     if (p == *arg)	    /* no name found */
6200 	return 0;
6201 
6202     len = (int)(p - *arg);
6203     *arg = p;
6204     return len;
6205 }
6206 
6207 /*
6208  * Get the length of the name of a function or internal variable.
6209  * "arg" is advanced to the first non-white character after the name.
6210  * Return 0 if something is wrong.
6211  */
6212     int
6213 get_id_len(char_u **arg)
6214 {
6215     char_u	*p;
6216     int		len;
6217 
6218     /* Find the end of the name. */
6219     for (p = *arg; eval_isnamec(*p); ++p)
6220     {
6221 	if (*p == ':')
6222 	{
6223 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6224 	     * slice "[n:]".  Also "xx:" is not a namespace. */
6225 	    len = (int)(p - *arg);
6226 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
6227 		    || len > 1)
6228 		break;
6229 	}
6230     }
6231     if (p == *arg)	    /* no name found */
6232 	return 0;
6233 
6234     len = (int)(p - *arg);
6235     *arg = skipwhite(p);
6236 
6237     return len;
6238 }
6239 
6240 /*
6241  * Get the length of the name of a variable or function.
6242  * Only the name is recognized, does not handle ".key" or "[idx]".
6243  * "arg" is advanced to the first non-white character after the name.
6244  * Return -1 if curly braces expansion failed.
6245  * Return 0 if something else is wrong.
6246  * If the name contains 'magic' {}'s, expand them and return the
6247  * expanded name in an allocated string via 'alias' - caller must free.
6248  */
6249     int
6250 get_name_len(
6251     char_u	**arg,
6252     char_u	**alias,
6253     int		evaluate,
6254     int		verbose)
6255 {
6256     int		len;
6257     char_u	*p;
6258     char_u	*expr_start;
6259     char_u	*expr_end;
6260 
6261     *alias = NULL;  /* default to no alias */
6262 
6263     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
6264 						  && (*arg)[2] == (int)KE_SNR)
6265     {
6266 	/* hard coded <SNR>, already translated */
6267 	*arg += 3;
6268 	return get_id_len(arg) + 3;
6269     }
6270     len = eval_fname_script(*arg);
6271     if (len > 0)
6272     {
6273 	/* literal "<SID>", "s:" or "<SNR>" */
6274 	*arg += len;
6275     }
6276 
6277     /*
6278      * Find the end of the name; check for {} construction.
6279      */
6280     p = find_name_end(*arg, &expr_start, &expr_end,
6281 					       len > 0 ? 0 : FNE_CHECK_START);
6282     if (expr_start != NULL)
6283     {
6284 	char_u	*temp_string;
6285 
6286 	if (!evaluate)
6287 	{
6288 	    len += (int)(p - *arg);
6289 	    *arg = skipwhite(p);
6290 	    return len;
6291 	}
6292 
6293 	/*
6294 	 * Include any <SID> etc in the expanded string:
6295 	 * Thus the -len here.
6296 	 */
6297 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
6298 	if (temp_string == NULL)
6299 	    return -1;
6300 	*alias = temp_string;
6301 	*arg = skipwhite(p);
6302 	return (int)STRLEN(temp_string);
6303     }
6304 
6305     len += get_id_len(arg);
6306     if (len == 0 && verbose)
6307 	EMSG2(_(e_invexpr2), *arg);
6308 
6309     return len;
6310 }
6311 
6312 /*
6313  * Find the end of a variable or function name, taking care of magic braces.
6314  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
6315  * start and end of the first magic braces item.
6316  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
6317  * Return a pointer to just after the name.  Equal to "arg" if there is no
6318  * valid name.
6319  */
6320     char_u *
6321 find_name_end(
6322     char_u	*arg,
6323     char_u	**expr_start,
6324     char_u	**expr_end,
6325     int		flags)
6326 {
6327     int		mb_nest = 0;
6328     int		br_nest = 0;
6329     char_u	*p;
6330     int		len;
6331 
6332     if (expr_start != NULL)
6333     {
6334 	*expr_start = NULL;
6335 	*expr_end = NULL;
6336     }
6337 
6338     /* Quick check for valid starting character. */
6339     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg) && *arg != '{')
6340 	return arg;
6341 
6342     for (p = arg; *p != NUL
6343 		    && (eval_isnamec(*p)
6344 			|| *p == '{'
6345 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
6346 			|| mb_nest != 0
6347 			|| br_nest != 0); mb_ptr_adv(p))
6348     {
6349 	if (*p == '\'')
6350 	{
6351 	    /* skip over 'string' to avoid counting [ and ] inside it. */
6352 	    for (p = p + 1; *p != NUL && *p != '\''; mb_ptr_adv(p))
6353 		;
6354 	    if (*p == NUL)
6355 		break;
6356 	}
6357 	else if (*p == '"')
6358 	{
6359 	    /* skip over "str\"ing" to avoid counting [ and ] inside it. */
6360 	    for (p = p + 1; *p != NUL && *p != '"'; mb_ptr_adv(p))
6361 		if (*p == '\\' && p[1] != NUL)
6362 		    ++p;
6363 	    if (*p == NUL)
6364 		break;
6365 	}
6366 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
6367 	{
6368 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6369 	     * slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is. */
6370 	    len = (int)(p - arg);
6371 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
6372 		    || (len > 1 && p[-1] != '}'))
6373 		break;
6374 	}
6375 
6376 	if (mb_nest == 0)
6377 	{
6378 	    if (*p == '[')
6379 		++br_nest;
6380 	    else if (*p == ']')
6381 		--br_nest;
6382 	}
6383 
6384 	if (br_nest == 0)
6385 	{
6386 	    if (*p == '{')
6387 	    {
6388 		mb_nest++;
6389 		if (expr_start != NULL && *expr_start == NULL)
6390 		    *expr_start = p;
6391 	    }
6392 	    else if (*p == '}')
6393 	    {
6394 		mb_nest--;
6395 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
6396 		    *expr_end = p;
6397 	    }
6398 	}
6399     }
6400 
6401     return p;
6402 }
6403 
6404 /*
6405  * Expands out the 'magic' {}'s in a variable/function name.
6406  * Note that this can call itself recursively, to deal with
6407  * constructs like foo{bar}{baz}{bam}
6408  * The four pointer arguments point to "foo{expre}ss{ion}bar"
6409  *			"in_start"      ^
6410  *			"expr_start"	   ^
6411  *			"expr_end"		 ^
6412  *			"in_end"			    ^
6413  *
6414  * Returns a new allocated string, which the caller must free.
6415  * Returns NULL for failure.
6416  */
6417     static char_u *
6418 make_expanded_name(
6419     char_u	*in_start,
6420     char_u	*expr_start,
6421     char_u	*expr_end,
6422     char_u	*in_end)
6423 {
6424     char_u	c1;
6425     char_u	*retval = NULL;
6426     char_u	*temp_result;
6427     char_u	*nextcmd = NULL;
6428 
6429     if (expr_end == NULL || in_end == NULL)
6430 	return NULL;
6431     *expr_start	= NUL;
6432     *expr_end = NUL;
6433     c1 = *in_end;
6434     *in_end = NUL;
6435 
6436     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
6437     if (temp_result != NULL && nextcmd == NULL)
6438     {
6439 	retval = alloc((unsigned)(STRLEN(temp_result) + (expr_start - in_start)
6440 						   + (in_end - expr_end) + 1));
6441 	if (retval != NULL)
6442 	{
6443 	    STRCPY(retval, in_start);
6444 	    STRCAT(retval, temp_result);
6445 	    STRCAT(retval, expr_end + 1);
6446 	}
6447     }
6448     vim_free(temp_result);
6449 
6450     *in_end = c1;		/* put char back for error messages */
6451     *expr_start = '{';
6452     *expr_end = '}';
6453 
6454     if (retval != NULL)
6455     {
6456 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
6457 	if (expr_start != NULL)
6458 	{
6459 	    /* Further expansion! */
6460 	    temp_result = make_expanded_name(retval, expr_start,
6461 						       expr_end, temp_result);
6462 	    vim_free(retval);
6463 	    retval = temp_result;
6464 	}
6465     }
6466 
6467     return retval;
6468 }
6469 
6470 /*
6471  * Return TRUE if character "c" can be used in a variable or function name.
6472  * Does not include '{' or '}' for magic braces.
6473  */
6474     int
6475 eval_isnamec(int c)
6476 {
6477     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
6478 }
6479 
6480 /*
6481  * Return TRUE if character "c" can be used as the first character in a
6482  * variable or function name (excluding '{' and '}').
6483  */
6484     int
6485 eval_isnamec1(int c)
6486 {
6487     return (ASCII_ISALPHA(c) || c == '_');
6488 }
6489 
6490 /*
6491  * Set number v: variable to "val".
6492  */
6493     void
6494 set_vim_var_nr(int idx, varnumber_T val)
6495 {
6496     vimvars[idx].vv_nr = val;
6497 }
6498 
6499 /*
6500  * Get number v: variable value.
6501  */
6502     varnumber_T
6503 get_vim_var_nr(int idx)
6504 {
6505     return vimvars[idx].vv_nr;
6506 }
6507 
6508 /*
6509  * Get string v: variable value.  Uses a static buffer, can only be used once.
6510  */
6511     char_u *
6512 get_vim_var_str(int idx)
6513 {
6514     return get_tv_string(&vimvars[idx].vv_tv);
6515 }
6516 
6517 /*
6518  * Get List v: variable value.  Caller must take care of reference count when
6519  * needed.
6520  */
6521     list_T *
6522 get_vim_var_list(int idx)
6523 {
6524     return vimvars[idx].vv_list;
6525 }
6526 
6527 /*
6528  * Set v:char to character "c".
6529  */
6530     void
6531 set_vim_var_char(int c)
6532 {
6533     char_u	buf[MB_MAXBYTES + 1];
6534 
6535 #ifdef FEAT_MBYTE
6536     if (has_mbyte)
6537 	buf[(*mb_char2bytes)(c, buf)] = NUL;
6538     else
6539 #endif
6540     {
6541 	buf[0] = c;
6542 	buf[1] = NUL;
6543     }
6544     set_vim_var_string(VV_CHAR, buf, -1);
6545 }
6546 
6547 /*
6548  * Set v:count to "count" and v:count1 to "count1".
6549  * When "set_prevcount" is TRUE first set v:prevcount from v:count.
6550  */
6551     void
6552 set_vcount(
6553     long	count,
6554     long	count1,
6555     int		set_prevcount)
6556 {
6557     if (set_prevcount)
6558 	vimvars[VV_PREVCOUNT].vv_nr = vimvars[VV_COUNT].vv_nr;
6559     vimvars[VV_COUNT].vv_nr = count;
6560     vimvars[VV_COUNT1].vv_nr = count1;
6561 }
6562 
6563 /*
6564  * Set string v: variable to a copy of "val".
6565  */
6566     void
6567 set_vim_var_string(
6568     int		idx,
6569     char_u	*val,
6570     int		len)	    /* length of "val" to use or -1 (whole string) */
6571 {
6572     clear_tv(&vimvars[idx].vv_di.di_tv);
6573     vimvars[idx].vv_type = VAR_STRING;
6574     if (val == NULL)
6575 	vimvars[idx].vv_str = NULL;
6576     else if (len == -1)
6577 	vimvars[idx].vv_str = vim_strsave(val);
6578     else
6579 	vimvars[idx].vv_str = vim_strnsave(val, len);
6580 }
6581 
6582 /*
6583  * Set List v: variable to "val".
6584  */
6585     void
6586 set_vim_var_list(int idx, list_T *val)
6587 {
6588     clear_tv(&vimvars[idx].vv_di.di_tv);
6589     vimvars[idx].vv_type = VAR_LIST;
6590     vimvars[idx].vv_list = val;
6591     if (val != NULL)
6592 	++val->lv_refcount;
6593 }
6594 
6595 /*
6596  * Set Dictionary v: variable to "val".
6597  */
6598     void
6599 set_vim_var_dict(int idx, dict_T *val)
6600 {
6601     int		todo;
6602     hashitem_T	*hi;
6603 
6604     clear_tv(&vimvars[idx].vv_di.di_tv);
6605     vimvars[idx].vv_type = VAR_DICT;
6606     vimvars[idx].vv_dict = val;
6607     if (val != NULL)
6608     {
6609 	++val->dv_refcount;
6610 
6611 	/* Set readonly */
6612 	todo = (int)val->dv_hashtab.ht_used;
6613 	for (hi = val->dv_hashtab.ht_array; todo > 0 ; ++hi)
6614 	{
6615 	    if (HASHITEM_EMPTY(hi))
6616 		continue;
6617 	    --todo;
6618 	    HI2DI(hi)->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
6619 	}
6620     }
6621 }
6622 
6623 /*
6624  * Set v:register if needed.
6625  */
6626     void
6627 set_reg_var(int c)
6628 {
6629     char_u	regname;
6630 
6631     if (c == 0 || c == ' ')
6632 	regname = '"';
6633     else
6634 	regname = c;
6635     /* Avoid free/alloc when the value is already right. */
6636     if (vimvars[VV_REG].vv_str == NULL || vimvars[VV_REG].vv_str[0] != c)
6637 	set_vim_var_string(VV_REG, &regname, 1);
6638 }
6639 
6640 /*
6641  * Get or set v:exception.  If "oldval" == NULL, return the current value.
6642  * Otherwise, restore the value to "oldval" and return NULL.
6643  * Must always be called in pairs to save and restore v:exception!  Does not
6644  * take care of memory allocations.
6645  */
6646     char_u *
6647 v_exception(char_u *oldval)
6648 {
6649     if (oldval == NULL)
6650 	return vimvars[VV_EXCEPTION].vv_str;
6651 
6652     vimvars[VV_EXCEPTION].vv_str = oldval;
6653     return NULL;
6654 }
6655 
6656 /*
6657  * Get or set v:throwpoint.  If "oldval" == NULL, return the current value.
6658  * Otherwise, restore the value to "oldval" and return NULL.
6659  * Must always be called in pairs to save and restore v:throwpoint!  Does not
6660  * take care of memory allocations.
6661  */
6662     char_u *
6663 v_throwpoint(char_u *oldval)
6664 {
6665     if (oldval == NULL)
6666 	return vimvars[VV_THROWPOINT].vv_str;
6667 
6668     vimvars[VV_THROWPOINT].vv_str = oldval;
6669     return NULL;
6670 }
6671 
6672 #if defined(FEAT_AUTOCMD) || defined(PROTO)
6673 /*
6674  * Set v:cmdarg.
6675  * If "eap" != NULL, use "eap" to generate the value and return the old value.
6676  * If "oldarg" != NULL, restore the value to "oldarg" and return NULL.
6677  * Must always be called in pairs!
6678  */
6679     char_u *
6680 set_cmdarg(exarg_T *eap, char_u *oldarg)
6681 {
6682     char_u	*oldval;
6683     char_u	*newval;
6684     unsigned	len;
6685 
6686     oldval = vimvars[VV_CMDARG].vv_str;
6687     if (eap == NULL)
6688     {
6689 	vim_free(oldval);
6690 	vimvars[VV_CMDARG].vv_str = oldarg;
6691 	return NULL;
6692     }
6693 
6694     if (eap->force_bin == FORCE_BIN)
6695 	len = 6;
6696     else if (eap->force_bin == FORCE_NOBIN)
6697 	len = 8;
6698     else
6699 	len = 0;
6700 
6701     if (eap->read_edit)
6702 	len += 7;
6703 
6704     if (eap->force_ff != 0)
6705 	len += (unsigned)STRLEN(eap->cmd + eap->force_ff) + 6;
6706 # ifdef FEAT_MBYTE
6707     if (eap->force_enc != 0)
6708 	len += (unsigned)STRLEN(eap->cmd + eap->force_enc) + 7;
6709     if (eap->bad_char != 0)
6710 	len += 7 + 4;  /* " ++bad=" + "keep" or "drop" */
6711 # endif
6712 
6713     newval = alloc(len + 1);
6714     if (newval == NULL)
6715 	return NULL;
6716 
6717     if (eap->force_bin == FORCE_BIN)
6718 	sprintf((char *)newval, " ++bin");
6719     else if (eap->force_bin == FORCE_NOBIN)
6720 	sprintf((char *)newval, " ++nobin");
6721     else
6722 	*newval = NUL;
6723 
6724     if (eap->read_edit)
6725 	STRCAT(newval, " ++edit");
6726 
6727     if (eap->force_ff != 0)
6728 	sprintf((char *)newval + STRLEN(newval), " ++ff=%s",
6729 						eap->cmd + eap->force_ff);
6730 # ifdef FEAT_MBYTE
6731     if (eap->force_enc != 0)
6732 	sprintf((char *)newval + STRLEN(newval), " ++enc=%s",
6733 					       eap->cmd + eap->force_enc);
6734     if (eap->bad_char == BAD_KEEP)
6735 	STRCPY(newval + STRLEN(newval), " ++bad=keep");
6736     else if (eap->bad_char == BAD_DROP)
6737 	STRCPY(newval + STRLEN(newval), " ++bad=drop");
6738     else if (eap->bad_char != 0)
6739 	sprintf((char *)newval + STRLEN(newval), " ++bad=%c", eap->bad_char);
6740 # endif
6741     vimvars[VV_CMDARG].vv_str = newval;
6742     return oldval;
6743 }
6744 #endif
6745 
6746 /*
6747  * Get the value of internal variable "name".
6748  * Return OK or FAIL.
6749  */
6750     int
6751 get_var_tv(
6752     char_u	*name,
6753     int		len,		/* length of "name" */
6754     typval_T	*rettv,		/* NULL when only checking existence */
6755     dictitem_T	**dip,		/* non-NULL when typval's dict item is needed */
6756     int		verbose,	/* may give error message */
6757     int		no_autoload)	/* do not use script autoloading */
6758 {
6759     int		ret = OK;
6760     typval_T	*tv = NULL;
6761     typval_T	atv;
6762     dictitem_T	*v;
6763     int		cc;
6764 
6765     /* truncate the name, so that we can use strcmp() */
6766     cc = name[len];
6767     name[len] = NUL;
6768 
6769     /*
6770      * Check for "b:changedtick".
6771      */
6772     if (STRCMP(name, "b:changedtick") == 0)
6773     {
6774 	atv.v_type = VAR_NUMBER;
6775 	atv.vval.v_number = curbuf->b_changedtick;
6776 	tv = &atv;
6777     }
6778 
6779     /*
6780      * Check for user-defined variables.
6781      */
6782     else
6783     {
6784 	v = find_var(name, NULL, no_autoload);
6785 	if (v != NULL)
6786 	{
6787 	    tv = &v->di_tv;
6788 	    if (dip != NULL)
6789 		*dip = v;
6790 	}
6791     }
6792 
6793     if (tv == NULL)
6794     {
6795 	if (rettv != NULL && verbose)
6796 	    EMSG2(_(e_undefvar), name);
6797 	ret = FAIL;
6798     }
6799     else if (rettv != NULL)
6800 	copy_tv(tv, rettv);
6801 
6802     name[len] = cc;
6803 
6804     return ret;
6805 }
6806 
6807 /*
6808  * Check if variable "name[len]" is a local variable or an argument.
6809  * If so, "*eval_lavars_used" is set to TRUE.
6810  */
6811     static void
6812 check_vars(char_u *name, int len)
6813 {
6814     int		cc;
6815     char_u	*varname;
6816     hashtab_T	*ht;
6817 
6818     if (eval_lavars_used == NULL)
6819 	return;
6820 
6821     /* truncate the name, so that we can use strcmp() */
6822     cc = name[len];
6823     name[len] = NUL;
6824 
6825     ht = find_var_ht(name, &varname);
6826     if (ht == get_funccal_local_ht() || ht == get_funccal_args_ht())
6827     {
6828 	if (find_var(name, NULL, TRUE) != NULL)
6829 	    *eval_lavars_used = TRUE;
6830     }
6831 
6832     name[len] = cc;
6833 }
6834 
6835 /*
6836  * Handle expr[expr], expr[expr:expr] subscript and .name lookup.
6837  * Also handle function call with Funcref variable: func(expr)
6838  * Can all be combined: dict.func(expr)[idx]['func'](expr)
6839  */
6840     int
6841 handle_subscript(
6842     char_u	**arg,
6843     typval_T	*rettv,
6844     int		evaluate,	/* do more than finding the end */
6845     int		verbose)	/* give error messages */
6846 {
6847     int		ret = OK;
6848     dict_T	*selfdict = NULL;
6849     char_u	*s;
6850     int		len;
6851     typval_T	functv;
6852 
6853     while (ret == OK
6854 	    && (**arg == '['
6855 		|| (**arg == '.' && rettv->v_type == VAR_DICT)
6856 		|| (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
6857 					    || rettv->v_type == VAR_PARTIAL)))
6858 	    && !vim_iswhite(*(*arg - 1)))
6859     {
6860 	if (**arg == '(')
6861 	{
6862 	    partial_T	*pt = NULL;
6863 
6864 	    /* need to copy the funcref so that we can clear rettv */
6865 	    if (evaluate)
6866 	    {
6867 		functv = *rettv;
6868 		rettv->v_type = VAR_UNKNOWN;
6869 
6870 		/* Invoke the function.  Recursive! */
6871 		if (functv.v_type == VAR_PARTIAL)
6872 		{
6873 		    pt = functv.vval.v_partial;
6874 		    s = pt->pt_name;
6875 		}
6876 		else
6877 		    s = functv.vval.v_string;
6878 	    }
6879 	    else
6880 		s = (char_u *)"";
6881 	    ret = get_func_tv(s, (int)STRLEN(s), rettv, arg,
6882 			curwin->w_cursor.lnum, curwin->w_cursor.lnum,
6883 			&len, evaluate, pt, selfdict);
6884 
6885 	    /* Clear the funcref afterwards, so that deleting it while
6886 	     * evaluating the arguments is possible (see test55). */
6887 	    if (evaluate)
6888 		clear_tv(&functv);
6889 
6890 	    /* Stop the expression evaluation when immediately aborting on
6891 	     * error, or when an interrupt occurred or an exception was thrown
6892 	     * but not caught. */
6893 	    if (aborting())
6894 	    {
6895 		if (ret == OK)
6896 		    clear_tv(rettv);
6897 		ret = FAIL;
6898 	    }
6899 	    dict_unref(selfdict);
6900 	    selfdict = NULL;
6901 	}
6902 	else /* **arg == '[' || **arg == '.' */
6903 	{
6904 	    dict_unref(selfdict);
6905 	    if (rettv->v_type == VAR_DICT)
6906 	    {
6907 		selfdict = rettv->vval.v_dict;
6908 		if (selfdict != NULL)
6909 		    ++selfdict->dv_refcount;
6910 	    }
6911 	    else
6912 		selfdict = NULL;
6913 	    if (eval_index(arg, rettv, evaluate, verbose) == FAIL)
6914 	    {
6915 		clear_tv(rettv);
6916 		ret = FAIL;
6917 	    }
6918 	}
6919     }
6920 
6921     /* Turn "dict.Func" into a partial for "Func" bound to "dict".
6922      * Don't do this when "Func" is already a partial that was bound
6923      * explicitly (pt_auto is FALSE). */
6924     if (selfdict != NULL
6925 	    && (rettv->v_type == VAR_FUNC
6926 		|| (rettv->v_type == VAR_PARTIAL
6927 		    && (rettv->vval.v_partial->pt_auto
6928 			|| rettv->vval.v_partial->pt_dict == NULL))))
6929 	selfdict = make_partial(selfdict, rettv);
6930 
6931     dict_unref(selfdict);
6932     return ret;
6933 }
6934 
6935 /*
6936  * Allocate memory for a variable type-value, and make it empty (0 or NULL
6937  * value).
6938  */
6939     typval_T *
6940 alloc_tv(void)
6941 {
6942     return (typval_T *)alloc_clear((unsigned)sizeof(typval_T));
6943 }
6944 
6945 /*
6946  * Allocate memory for a variable type-value, and assign a string to it.
6947  * The string "s" must have been allocated, it is consumed.
6948  * Return NULL for out of memory, the variable otherwise.
6949  */
6950     static typval_T *
6951 alloc_string_tv(char_u *s)
6952 {
6953     typval_T	*rettv;
6954 
6955     rettv = alloc_tv();
6956     if (rettv != NULL)
6957     {
6958 	rettv->v_type = VAR_STRING;
6959 	rettv->vval.v_string = s;
6960     }
6961     else
6962 	vim_free(s);
6963     return rettv;
6964 }
6965 
6966 /*
6967  * Free the memory for a variable type-value.
6968  */
6969     void
6970 free_tv(typval_T *varp)
6971 {
6972     if (varp != NULL)
6973     {
6974 	switch (varp->v_type)
6975 	{
6976 	    case VAR_FUNC:
6977 		func_unref(varp->vval.v_string);
6978 		/*FALLTHROUGH*/
6979 	    case VAR_STRING:
6980 		vim_free(varp->vval.v_string);
6981 		break;
6982 	    case VAR_PARTIAL:
6983 		partial_unref(varp->vval.v_partial);
6984 		break;
6985 	    case VAR_LIST:
6986 		list_unref(varp->vval.v_list);
6987 		break;
6988 	    case VAR_DICT:
6989 		dict_unref(varp->vval.v_dict);
6990 		break;
6991 	    case VAR_JOB:
6992 #ifdef FEAT_JOB_CHANNEL
6993 		job_unref(varp->vval.v_job);
6994 		break;
6995 #endif
6996 	    case VAR_CHANNEL:
6997 #ifdef FEAT_JOB_CHANNEL
6998 		channel_unref(varp->vval.v_channel);
6999 		break;
7000 #endif
7001 	    case VAR_NUMBER:
7002 	    case VAR_FLOAT:
7003 	    case VAR_UNKNOWN:
7004 	    case VAR_SPECIAL:
7005 		break;
7006 	}
7007 	vim_free(varp);
7008     }
7009 }
7010 
7011 /*
7012  * Free the memory for a variable value and set the value to NULL or 0.
7013  */
7014     void
7015 clear_tv(typval_T *varp)
7016 {
7017     if (varp != NULL)
7018     {
7019 	switch (varp->v_type)
7020 	{
7021 	    case VAR_FUNC:
7022 		func_unref(varp->vval.v_string);
7023 		/*FALLTHROUGH*/
7024 	    case VAR_STRING:
7025 		vim_free(varp->vval.v_string);
7026 		varp->vval.v_string = NULL;
7027 		break;
7028 	    case VAR_PARTIAL:
7029 		partial_unref(varp->vval.v_partial);
7030 		varp->vval.v_partial = NULL;
7031 		break;
7032 	    case VAR_LIST:
7033 		list_unref(varp->vval.v_list);
7034 		varp->vval.v_list = NULL;
7035 		break;
7036 	    case VAR_DICT:
7037 		dict_unref(varp->vval.v_dict);
7038 		varp->vval.v_dict = NULL;
7039 		break;
7040 	    case VAR_NUMBER:
7041 	    case VAR_SPECIAL:
7042 		varp->vval.v_number = 0;
7043 		break;
7044 	    case VAR_FLOAT:
7045 #ifdef FEAT_FLOAT
7046 		varp->vval.v_float = 0.0;
7047 		break;
7048 #endif
7049 	    case VAR_JOB:
7050 #ifdef FEAT_JOB_CHANNEL
7051 		job_unref(varp->vval.v_job);
7052 		varp->vval.v_job = NULL;
7053 #endif
7054 		break;
7055 	    case VAR_CHANNEL:
7056 #ifdef FEAT_JOB_CHANNEL
7057 		channel_unref(varp->vval.v_channel);
7058 		varp->vval.v_channel = NULL;
7059 #endif
7060 	    case VAR_UNKNOWN:
7061 		break;
7062 	}
7063 	varp->v_lock = 0;
7064     }
7065 }
7066 
7067 /*
7068  * Set the value of a variable to NULL without freeing items.
7069  */
7070     void
7071 init_tv(typval_T *varp)
7072 {
7073     if (varp != NULL)
7074 	vim_memset(varp, 0, sizeof(typval_T));
7075 }
7076 
7077 /*
7078  * Get the number value of a variable.
7079  * If it is a String variable, uses vim_str2nr().
7080  * For incompatible types, return 0.
7081  * get_tv_number_chk() is similar to get_tv_number(), but informs the
7082  * caller of incompatible types: it sets *denote to TRUE if "denote"
7083  * is not NULL or returns -1 otherwise.
7084  */
7085     varnumber_T
7086 get_tv_number(typval_T *varp)
7087 {
7088     int		error = FALSE;
7089 
7090     return get_tv_number_chk(varp, &error);	/* return 0L on error */
7091 }
7092 
7093     varnumber_T
7094 get_tv_number_chk(typval_T *varp, int *denote)
7095 {
7096     varnumber_T	n = 0L;
7097 
7098     switch (varp->v_type)
7099     {
7100 	case VAR_NUMBER:
7101 	    return varp->vval.v_number;
7102 	case VAR_FLOAT:
7103 #ifdef FEAT_FLOAT
7104 	    EMSG(_("E805: Using a Float as a Number"));
7105 	    break;
7106 #endif
7107 	case VAR_FUNC:
7108 	case VAR_PARTIAL:
7109 	    EMSG(_("E703: Using a Funcref as a Number"));
7110 	    break;
7111 	case VAR_STRING:
7112 	    if (varp->vval.v_string != NULL)
7113 		vim_str2nr(varp->vval.v_string, NULL, NULL,
7114 						    STR2NR_ALL, &n, NULL, 0);
7115 	    return n;
7116 	case VAR_LIST:
7117 	    EMSG(_("E745: Using a List as a Number"));
7118 	    break;
7119 	case VAR_DICT:
7120 	    EMSG(_("E728: Using a Dictionary as a Number"));
7121 	    break;
7122 	case VAR_SPECIAL:
7123 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
7124 	    break;
7125 	case VAR_JOB:
7126 #ifdef FEAT_JOB_CHANNEL
7127 	    EMSG(_("E910: Using a Job as a Number"));
7128 	    break;
7129 #endif
7130 	case VAR_CHANNEL:
7131 #ifdef FEAT_JOB_CHANNEL
7132 	    EMSG(_("E913: Using a Channel as a Number"));
7133 	    break;
7134 #endif
7135 	case VAR_UNKNOWN:
7136 	    EMSG2(_(e_intern2), "get_tv_number(UNKNOWN)");
7137 	    break;
7138     }
7139     if (denote == NULL)		/* useful for values that must be unsigned */
7140 	n = -1;
7141     else
7142 	*denote = TRUE;
7143     return n;
7144 }
7145 
7146 #ifdef FEAT_FLOAT
7147     float_T
7148 get_tv_float(typval_T *varp)
7149 {
7150     switch (varp->v_type)
7151     {
7152 	case VAR_NUMBER:
7153 	    return (float_T)(varp->vval.v_number);
7154 	case VAR_FLOAT:
7155 	    return varp->vval.v_float;
7156 	case VAR_FUNC:
7157 	case VAR_PARTIAL:
7158 	    EMSG(_("E891: Using a Funcref as a Float"));
7159 	    break;
7160 	case VAR_STRING:
7161 	    EMSG(_("E892: Using a String as a Float"));
7162 	    break;
7163 	case VAR_LIST:
7164 	    EMSG(_("E893: Using a List as a Float"));
7165 	    break;
7166 	case VAR_DICT:
7167 	    EMSG(_("E894: Using a Dictionary as a Float"));
7168 	    break;
7169 	case VAR_SPECIAL:
7170 	    EMSG(_("E907: Using a special value as a Float"));
7171 	    break;
7172 	case VAR_JOB:
7173 # ifdef FEAT_JOB_CHANNEL
7174 	    EMSG(_("E911: Using a Job as a Float"));
7175 	    break;
7176 # endif
7177 	case VAR_CHANNEL:
7178 # ifdef FEAT_JOB_CHANNEL
7179 	    EMSG(_("E914: Using a Channel as a Float"));
7180 	    break;
7181 # endif
7182 	case VAR_UNKNOWN:
7183 	    EMSG2(_(e_intern2), "get_tv_float(UNKNOWN)");
7184 	    break;
7185     }
7186     return 0;
7187 }
7188 #endif
7189 
7190 /*
7191  * Get the string value of a variable.
7192  * If it is a Number variable, the number is converted into a string.
7193  * get_tv_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7194  * get_tv_string_buf() uses a given buffer.
7195  * If the String variable has never been set, return an empty string.
7196  * Never returns NULL;
7197  * get_tv_string_chk() and get_tv_string_buf_chk() are similar, but return
7198  * NULL on error.
7199  */
7200     char_u *
7201 get_tv_string(typval_T *varp)
7202 {
7203     static char_u   mybuf[NUMBUFLEN];
7204 
7205     return get_tv_string_buf(varp, mybuf);
7206 }
7207 
7208     char_u *
7209 get_tv_string_buf(typval_T *varp, char_u *buf)
7210 {
7211     char_u	*res =  get_tv_string_buf_chk(varp, buf);
7212 
7213     return res != NULL ? res : (char_u *)"";
7214 }
7215 
7216 /*
7217  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7218  */
7219     char_u *
7220 get_tv_string_chk(typval_T *varp)
7221 {
7222     static char_u   mybuf[NUMBUFLEN];
7223 
7224     return get_tv_string_buf_chk(varp, mybuf);
7225 }
7226 
7227     char_u *
7228 get_tv_string_buf_chk(typval_T *varp, char_u *buf)
7229 {
7230     switch (varp->v_type)
7231     {
7232 	case VAR_NUMBER:
7233 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
7234 					    (varnumber_T)varp->vval.v_number);
7235 	    return buf;
7236 	case VAR_FUNC:
7237 	case VAR_PARTIAL:
7238 	    EMSG(_("E729: using Funcref as a String"));
7239 	    break;
7240 	case VAR_LIST:
7241 	    EMSG(_("E730: using List as a String"));
7242 	    break;
7243 	case VAR_DICT:
7244 	    EMSG(_("E731: using Dictionary as a String"));
7245 	    break;
7246 	case VAR_FLOAT:
7247 #ifdef FEAT_FLOAT
7248 	    EMSG(_(e_float_as_string));
7249 	    break;
7250 #endif
7251 	case VAR_STRING:
7252 	    if (varp->vval.v_string != NULL)
7253 		return varp->vval.v_string;
7254 	    return (char_u *)"";
7255 	case VAR_SPECIAL:
7256 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
7257 	    return buf;
7258 	case VAR_JOB:
7259 #ifdef FEAT_JOB_CHANNEL
7260 	    {
7261 		job_T *job = varp->vval.v_job;
7262 		char  *status;
7263 
7264 		if (job == NULL)
7265 		    return (char_u *)"no process";
7266 		status = job->jv_status == JOB_FAILED ? "fail"
7267 				: job->jv_status == JOB_ENDED ? "dead"
7268 				: "run";
7269 # ifdef UNIX
7270 		vim_snprintf((char *)buf, NUMBUFLEN,
7271 			    "process %ld %s", (long)job->jv_pid, status);
7272 # elif defined(WIN32)
7273 		vim_snprintf((char *)buf, NUMBUFLEN,
7274 			    "process %ld %s",
7275 			    (long)job->jv_proc_info.dwProcessId,
7276 			    status);
7277 # else
7278 		/* fall-back */
7279 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
7280 # endif
7281 		return buf;
7282 	    }
7283 #endif
7284 	    break;
7285 	case VAR_CHANNEL:
7286 #ifdef FEAT_JOB_CHANNEL
7287 	    {
7288 		channel_T *channel = varp->vval.v_channel;
7289 		char      *status = channel_status(channel);
7290 
7291 		if (channel == NULL)
7292 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
7293 		else
7294 		    vim_snprintf((char *)buf, NUMBUFLEN,
7295 				     "channel %d %s", channel->ch_id, status);
7296 		return buf;
7297 	    }
7298 #endif
7299 	    break;
7300 	case VAR_UNKNOWN:
7301 	    EMSG(_("E908: using an invalid value as a String"));
7302 	    break;
7303     }
7304     return NULL;
7305 }
7306 
7307 /*
7308  * Find variable "name" in the list of variables.
7309  * Return a pointer to it if found, NULL if not found.
7310  * Careful: "a:0" variables don't have a name.
7311  * When "htp" is not NULL we are writing to the variable, set "htp" to the
7312  * hashtab_T used.
7313  */
7314     dictitem_T *
7315 find_var(char_u *name, hashtab_T **htp, int no_autoload)
7316 {
7317     char_u	*varname;
7318     hashtab_T	*ht;
7319     dictitem_T	*ret = NULL;
7320 
7321     ht = find_var_ht(name, &varname);
7322     if (htp != NULL)
7323 	*htp = ht;
7324     if (ht == NULL)
7325 	return NULL;
7326     ret = find_var_in_ht(ht, *name, varname, no_autoload || htp != NULL);
7327     if (ret != NULL)
7328 	return ret;
7329 
7330     /* Search in parent scope for lambda */
7331     return find_var_in_scoped_ht(name, varname ? &varname : NULL,
7332 		no_autoload || htp != NULL);
7333 }
7334 
7335 /*
7336  * Find variable "varname" in hashtab "ht" with name "htname".
7337  * Returns NULL if not found.
7338  */
7339     dictitem_T *
7340 find_var_in_ht(
7341     hashtab_T	*ht,
7342     int		htname,
7343     char_u	*varname,
7344     int		no_autoload)
7345 {
7346     hashitem_T	*hi;
7347 
7348     if (*varname == NUL)
7349     {
7350 	/* Must be something like "s:", otherwise "ht" would be NULL. */
7351 	switch (htname)
7352 	{
7353 	    case 's': return &SCRIPT_SV(current_SID)->sv_var;
7354 	    case 'g': return &globvars_var;
7355 	    case 'v': return &vimvars_var;
7356 	    case 'b': return &curbuf->b_bufvar;
7357 	    case 'w': return &curwin->w_winvar;
7358 #ifdef FEAT_WINDOWS
7359 	    case 't': return &curtab->tp_winvar;
7360 #endif
7361 	    case 'l': return get_funccal_local_var();
7362 	    case 'a': return get_funccal_args_var();
7363 	}
7364 	return NULL;
7365     }
7366 
7367     hi = hash_find(ht, varname);
7368     if (HASHITEM_EMPTY(hi))
7369     {
7370 	/* For global variables we may try auto-loading the script.  If it
7371 	 * worked find the variable again.  Don't auto-load a script if it was
7372 	 * loaded already, otherwise it would be loaded every time when
7373 	 * checking if a function name is a Funcref variable. */
7374 	if (ht == &globvarht && !no_autoload)
7375 	{
7376 	    /* Note: script_autoload() may make "hi" invalid. It must either
7377 	     * be obtained again or not used. */
7378 	    if (!script_autoload(varname, FALSE) || aborting())
7379 		return NULL;
7380 	    hi = hash_find(ht, varname);
7381 	}
7382 	if (HASHITEM_EMPTY(hi))
7383 	    return NULL;
7384     }
7385     return HI2DI(hi);
7386 }
7387 
7388 /*
7389  * Find the hashtab used for a variable name.
7390  * Return NULL if the name is not valid.
7391  * Set "varname" to the start of name without ':'.
7392  */
7393     hashtab_T *
7394 find_var_ht(char_u *name, char_u **varname)
7395 {
7396     hashitem_T	*hi;
7397     hashtab_T	*ht;
7398 
7399     if (name[0] == NUL)
7400 	return NULL;
7401     if (name[1] != ':')
7402     {
7403 	/* The name must not start with a colon or #. */
7404 	if (name[0] == ':' || name[0] == AUTOLOAD_CHAR)
7405 	    return NULL;
7406 	*varname = name;
7407 
7408 	/* "version" is "v:version" in all scopes */
7409 	hi = hash_find(&compat_hashtab, name);
7410 	if (!HASHITEM_EMPTY(hi))
7411 	    return &compat_hashtab;
7412 
7413 	ht = get_funccal_local_ht();
7414 	if (ht == NULL)
7415 	    return &globvarht;			/* global variable */
7416 	return ht;				/* local variable */
7417     }
7418     *varname = name + 2;
7419     if (*name == 'g')				/* global variable */
7420 	return &globvarht;
7421     /* There must be no ':' or '#' in the rest of the name, unless g: is used
7422      */
7423     if (vim_strchr(name + 2, ':') != NULL
7424 			       || vim_strchr(name + 2, AUTOLOAD_CHAR) != NULL)
7425 	return NULL;
7426     if (*name == 'b')				/* buffer variable */
7427 	return &curbuf->b_vars->dv_hashtab;
7428     if (*name == 'w')				/* window variable */
7429 	return &curwin->w_vars->dv_hashtab;
7430 #ifdef FEAT_WINDOWS
7431     if (*name == 't')				/* tab page variable */
7432 	return &curtab->tp_vars->dv_hashtab;
7433 #endif
7434     if (*name == 'v')				/* v: variable */
7435 	return &vimvarht;
7436     if (*name == 'a')				/* a: function argument */
7437 	return get_funccal_args_ht();
7438     if (*name == 'l')				/* l: local function variable */
7439 	return get_funccal_local_ht();
7440     if (*name == 's'				/* script variable */
7441 	    && current_SID > 0 && current_SID <= ga_scripts.ga_len)
7442 	return &SCRIPT_VARS(current_SID);
7443     return NULL;
7444 }
7445 
7446 /*
7447  * Get the string value of a (global/local) variable.
7448  * Note: see get_tv_string() for how long the pointer remains valid.
7449  * Returns NULL when it doesn't exist.
7450  */
7451     char_u *
7452 get_var_value(char_u *name)
7453 {
7454     dictitem_T	*v;
7455 
7456     v = find_var(name, NULL, FALSE);
7457     if (v == NULL)
7458 	return NULL;
7459     return get_tv_string(&v->di_tv);
7460 }
7461 
7462 /*
7463  * Allocate a new hashtab for a sourced script.  It will be used while
7464  * sourcing this script and when executing functions defined in the script.
7465  */
7466     void
7467 new_script_vars(scid_T id)
7468 {
7469     int		i;
7470     hashtab_T	*ht;
7471     scriptvar_T *sv;
7472 
7473     if (ga_grow(&ga_scripts, (int)(id - ga_scripts.ga_len)) == OK)
7474     {
7475 	/* Re-allocating ga_data means that an ht_array pointing to
7476 	 * ht_smallarray becomes invalid.  We can recognize this: ht_mask is
7477 	 * at its init value.  Also reset "v_dict", it's always the same. */
7478 	for (i = 1; i <= ga_scripts.ga_len; ++i)
7479 	{
7480 	    ht = &SCRIPT_VARS(i);
7481 	    if (ht->ht_mask == HT_INIT_SIZE - 1)
7482 		ht->ht_array = ht->ht_smallarray;
7483 	    sv = SCRIPT_SV(i);
7484 	    sv->sv_var.di_tv.vval.v_dict = &sv->sv_dict;
7485 	}
7486 
7487 	while (ga_scripts.ga_len < id)
7488 	{
7489 	    sv = SCRIPT_SV(ga_scripts.ga_len + 1) =
7490 		(scriptvar_T *)alloc_clear(sizeof(scriptvar_T));
7491 	    init_var_dict(&sv->sv_dict, &sv->sv_var, VAR_SCOPE);
7492 	    ++ga_scripts.ga_len;
7493 	}
7494     }
7495 }
7496 
7497 /*
7498  * Initialize dictionary "dict" as a scope and set variable "dict_var" to
7499  * point to it.
7500  */
7501     void
7502 init_var_dict(dict_T *dict, dictitem_T *dict_var, int scope)
7503 {
7504     hash_init(&dict->dv_hashtab);
7505     dict->dv_lock = 0;
7506     dict->dv_scope = scope;
7507     dict->dv_refcount = DO_NOT_FREE_CNT;
7508     dict->dv_copyID = 0;
7509     dict_var->di_tv.vval.v_dict = dict;
7510     dict_var->di_tv.v_type = VAR_DICT;
7511     dict_var->di_tv.v_lock = VAR_FIXED;
7512     dict_var->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
7513     dict_var->di_key[0] = NUL;
7514 }
7515 
7516 /*
7517  * Unreference a dictionary initialized by init_var_dict().
7518  */
7519     void
7520 unref_var_dict(dict_T *dict)
7521 {
7522     /* Now the dict needs to be freed if no one else is using it, go back to
7523      * normal reference counting. */
7524     dict->dv_refcount -= DO_NOT_FREE_CNT - 1;
7525     dict_unref(dict);
7526 }
7527 
7528 /*
7529  * Clean up a list of internal variables.
7530  * Frees all allocated variables and the value they contain.
7531  * Clears hashtab "ht", does not free it.
7532  */
7533     void
7534 vars_clear(hashtab_T *ht)
7535 {
7536     vars_clear_ext(ht, TRUE);
7537 }
7538 
7539 /*
7540  * Like vars_clear(), but only free the value if "free_val" is TRUE.
7541  */
7542     void
7543 vars_clear_ext(hashtab_T *ht, int free_val)
7544 {
7545     int		todo;
7546     hashitem_T	*hi;
7547     dictitem_T	*v;
7548 
7549     hash_lock(ht);
7550     todo = (int)ht->ht_used;
7551     for (hi = ht->ht_array; todo > 0; ++hi)
7552     {
7553 	if (!HASHITEM_EMPTY(hi))
7554 	{
7555 	    --todo;
7556 
7557 	    /* Free the variable.  Don't remove it from the hashtab,
7558 	     * ht_array might change then.  hash_clear() takes care of it
7559 	     * later. */
7560 	    v = HI2DI(hi);
7561 	    if (free_val)
7562 		clear_tv(&v->di_tv);
7563 	    if (v->di_flags & DI_FLAGS_ALLOC)
7564 		vim_free(v);
7565 	}
7566     }
7567     hash_clear(ht);
7568     ht->ht_used = 0;
7569 }
7570 
7571 /*
7572  * Delete a variable from hashtab "ht" at item "hi".
7573  * Clear the variable value and free the dictitem.
7574  */
7575     static void
7576 delete_var(hashtab_T *ht, hashitem_T *hi)
7577 {
7578     dictitem_T	*di = HI2DI(hi);
7579 
7580     hash_remove(ht, hi);
7581     clear_tv(&di->di_tv);
7582     vim_free(di);
7583 }
7584 
7585 /*
7586  * List the value of one internal variable.
7587  */
7588     static void
7589 list_one_var(dictitem_T *v, char_u *prefix, int *first)
7590 {
7591     char_u	*tofree;
7592     char_u	*s;
7593     char_u	numbuf[NUMBUFLEN];
7594 
7595     s = echo_string(&v->di_tv, &tofree, numbuf, get_copyID());
7596     list_one_var_a(prefix, v->di_key, v->di_tv.v_type,
7597 					 s == NULL ? (char_u *)"" : s, first);
7598     vim_free(tofree);
7599 }
7600 
7601     static void
7602 list_one_var_a(
7603     char_u	*prefix,
7604     char_u	*name,
7605     int		type,
7606     char_u	*string,
7607     int		*first)  /* when TRUE clear rest of screen and set to FALSE */
7608 {
7609     /* don't use msg() or msg_attr() to avoid overwriting "v:statusmsg" */
7610     msg_start();
7611     msg_puts(prefix);
7612     if (name != NULL)	/* "a:" vars don't have a name stored */
7613 	msg_puts(name);
7614     msg_putchar(' ');
7615     msg_advance(22);
7616     if (type == VAR_NUMBER)
7617 	msg_putchar('#');
7618     else if (type == VAR_FUNC || type == VAR_PARTIAL)
7619 	msg_putchar('*');
7620     else if (type == VAR_LIST)
7621     {
7622 	msg_putchar('[');
7623 	if (*string == '[')
7624 	    ++string;
7625     }
7626     else if (type == VAR_DICT)
7627     {
7628 	msg_putchar('{');
7629 	if (*string == '{')
7630 	    ++string;
7631     }
7632     else
7633 	msg_putchar(' ');
7634 
7635     msg_outtrans(string);
7636 
7637     if (type == VAR_FUNC || type == VAR_PARTIAL)
7638 	msg_puts((char_u *)"()");
7639     if (*first)
7640     {
7641 	msg_clr_eos();
7642 	*first = FALSE;
7643     }
7644 }
7645 
7646 /*
7647  * Set variable "name" to value in "tv".
7648  * If the variable already exists, the value is updated.
7649  * Otherwise the variable is created.
7650  */
7651     void
7652 set_var(
7653     char_u	*name,
7654     typval_T	*tv,
7655     int		copy)	    /* make copy of value in "tv" */
7656 {
7657     dictitem_T	*v;
7658     char_u	*varname;
7659     hashtab_T	*ht;
7660 
7661     ht = find_var_ht(name, &varname);
7662     if (ht == NULL || *varname == NUL)
7663     {
7664 	EMSG2(_(e_illvar), name);
7665 	return;
7666     }
7667     v = find_var_in_ht(ht, 0, varname, TRUE);
7668 
7669     /* Search in parent scope which is possible to reference from lambda */
7670     if (v == NULL)
7671 	v = find_var_in_scoped_ht(name, varname ? &varname : NULL, TRUE);
7672 
7673     if ((tv->v_type == VAR_FUNC || tv->v_type == VAR_PARTIAL)
7674 				      && var_check_func_name(name, v == NULL))
7675 	return;
7676 
7677     if (v != NULL)
7678     {
7679 	/* existing variable, need to clear the value */
7680 	if (var_check_ro(v->di_flags, name, FALSE)
7681 			       || tv_check_lock(v->di_tv.v_lock, name, FALSE))
7682 	    return;
7683 
7684 	/*
7685 	 * Handle setting internal v: variables separately where needed to
7686 	 * prevent changing the type.
7687 	 */
7688 	if (ht == &vimvarht)
7689 	{
7690 	    if (v->di_tv.v_type == VAR_STRING)
7691 	    {
7692 		vim_free(v->di_tv.vval.v_string);
7693 		if (copy || tv->v_type != VAR_STRING)
7694 		    v->di_tv.vval.v_string = vim_strsave(get_tv_string(tv));
7695 		else
7696 		{
7697 		    /* Take over the string to avoid an extra alloc/free. */
7698 		    v->di_tv.vval.v_string = tv->vval.v_string;
7699 		    tv->vval.v_string = NULL;
7700 		}
7701 		return;
7702 	    }
7703 	    else if (v->di_tv.v_type == VAR_NUMBER)
7704 	    {
7705 		v->di_tv.vval.v_number = get_tv_number(tv);
7706 		if (STRCMP(varname, "searchforward") == 0)
7707 		    set_search_direction(v->di_tv.vval.v_number ? '/' : '?');
7708 #ifdef FEAT_SEARCH_EXTRA
7709 		else if (STRCMP(varname, "hlsearch") == 0)
7710 		{
7711 		    no_hlsearch = !v->di_tv.vval.v_number;
7712 		    redraw_all_later(SOME_VALID);
7713 		}
7714 #endif
7715 		return;
7716 	    }
7717 	    else if (v->di_tv.v_type != tv->v_type)
7718 		EMSG2(_(e_intern2), "set_var()");
7719 	}
7720 
7721 	clear_tv(&v->di_tv);
7722     }
7723     else		    /* add a new variable */
7724     {
7725 	/* Can't add "v:" variable. */
7726 	if (ht == &vimvarht)
7727 	{
7728 	    EMSG2(_(e_illvar), name);
7729 	    return;
7730 	}
7731 
7732 	/* Make sure the variable name is valid. */
7733 	if (!valid_varname(varname))
7734 	    return;
7735 
7736 	v = (dictitem_T *)alloc((unsigned)(sizeof(dictitem_T)
7737 							  + STRLEN(varname)));
7738 	if (v == NULL)
7739 	    return;
7740 	STRCPY(v->di_key, varname);
7741 	if (hash_add(ht, DI2HIKEY(v)) == FAIL)
7742 	{
7743 	    vim_free(v);
7744 	    return;
7745 	}
7746 	v->di_flags = DI_FLAGS_ALLOC;
7747     }
7748 
7749     if (copy || tv->v_type == VAR_NUMBER || tv->v_type == VAR_FLOAT)
7750 	copy_tv(tv, &v->di_tv);
7751     else
7752     {
7753 	v->di_tv = *tv;
7754 	v->di_tv.v_lock = 0;
7755 	init_tv(tv);
7756     }
7757 }
7758 
7759 /*
7760  * Return TRUE if di_flags "flags" indicates variable "name" is read-only.
7761  * Also give an error message.
7762  */
7763     int
7764 var_check_ro(int flags, char_u *name, int use_gettext)
7765 {
7766     if (flags & DI_FLAGS_RO)
7767     {
7768 	EMSG2(_(e_readonlyvar), use_gettext ? (char_u *)_(name) : name);
7769 	return TRUE;
7770     }
7771     if ((flags & DI_FLAGS_RO_SBX) && sandbox)
7772     {
7773 	EMSG2(_(e_readonlysbx), use_gettext ? (char_u *)_(name) : name);
7774 	return TRUE;
7775     }
7776     return FALSE;
7777 }
7778 
7779 /*
7780  * Return TRUE if di_flags "flags" indicates variable "name" is fixed.
7781  * Also give an error message.
7782  */
7783     int
7784 var_check_fixed(int flags, char_u *name, int use_gettext)
7785 {
7786     if (flags & DI_FLAGS_FIX)
7787     {
7788 	EMSG2(_("E795: Cannot delete variable %s"),
7789 				      use_gettext ? (char_u *)_(name) : name);
7790 	return TRUE;
7791     }
7792     return FALSE;
7793 }
7794 
7795 /*
7796  * Check if a funcref is assigned to a valid variable name.
7797  * Return TRUE and give an error if not.
7798  */
7799     int
7800 var_check_func_name(
7801     char_u *name,    /* points to start of variable name */
7802     int    new_var)  /* TRUE when creating the variable */
7803 {
7804     /* Allow for w: b: s: and t:. */
7805     if (!(vim_strchr((char_u *)"wbst", name[0]) != NULL && name[1] == ':')
7806 	    && !ASCII_ISUPPER((name[0] != NUL && name[1] == ':')
7807 						     ? name[2] : name[0]))
7808     {
7809 	EMSG2(_("E704: Funcref variable name must start with a capital: %s"),
7810 									name);
7811 	return TRUE;
7812     }
7813     /* Don't allow hiding a function.  When "v" is not NULL we might be
7814      * assigning another function to the same var, the type is checked
7815      * below. */
7816     if (new_var && function_exists(name, FALSE))
7817     {
7818 	EMSG2(_("E705: Variable name conflicts with existing function: %s"),
7819 								    name);
7820 	return TRUE;
7821     }
7822     return FALSE;
7823 }
7824 
7825 /*
7826  * Check if a variable name is valid.
7827  * Return FALSE and give an error if not.
7828  */
7829     int
7830 valid_varname(char_u *varname)
7831 {
7832     char_u *p;
7833 
7834     for (p = varname; *p != NUL; ++p)
7835 	if (!eval_isnamec1(*p) && (p == varname || !VIM_ISDIGIT(*p))
7836 						   && *p != AUTOLOAD_CHAR)
7837 	{
7838 	    EMSG2(_(e_illvar), varname);
7839 	    return FALSE;
7840 	}
7841     return TRUE;
7842 }
7843 
7844 /*
7845  * Return TRUE if typeval "tv" is set to be locked (immutable).
7846  * Also give an error message, using "name" or _("name") when use_gettext is
7847  * TRUE.
7848  */
7849     int
7850 tv_check_lock(int lock, char_u *name, int use_gettext)
7851 {
7852     if (lock & VAR_LOCKED)
7853     {
7854 	EMSG2(_("E741: Value is locked: %s"),
7855 				name == NULL ? (char_u *)_("Unknown")
7856 					     : use_gettext ? (char_u *)_(name)
7857 					     : name);
7858 	return TRUE;
7859     }
7860     if (lock & VAR_FIXED)
7861     {
7862 	EMSG2(_("E742: Cannot change value of %s"),
7863 				name == NULL ? (char_u *)_("Unknown")
7864 					     : use_gettext ? (char_u *)_(name)
7865 					     : name);
7866 	return TRUE;
7867     }
7868     return FALSE;
7869 }
7870 
7871 /*
7872  * Copy the values from typval_T "from" to typval_T "to".
7873  * When needed allocates string or increases reference count.
7874  * Does not make a copy of a list or dict but copies the reference!
7875  * It is OK for "from" and "to" to point to the same item.  This is used to
7876  * make a copy later.
7877  */
7878     void
7879 copy_tv(typval_T *from, typval_T *to)
7880 {
7881     to->v_type = from->v_type;
7882     to->v_lock = 0;
7883     switch (from->v_type)
7884     {
7885 	case VAR_NUMBER:
7886 	case VAR_SPECIAL:
7887 	    to->vval.v_number = from->vval.v_number;
7888 	    break;
7889 	case VAR_FLOAT:
7890 #ifdef FEAT_FLOAT
7891 	    to->vval.v_float = from->vval.v_float;
7892 	    break;
7893 #endif
7894 	case VAR_JOB:
7895 #ifdef FEAT_JOB_CHANNEL
7896 	    to->vval.v_job = from->vval.v_job;
7897 	    if (to->vval.v_job != NULL)
7898 		++to->vval.v_job->jv_refcount;
7899 	    break;
7900 #endif
7901 	case VAR_CHANNEL:
7902 #ifdef FEAT_JOB_CHANNEL
7903 	    to->vval.v_channel = from->vval.v_channel;
7904 	    if (to->vval.v_channel != NULL)
7905 		++to->vval.v_channel->ch_refcount;
7906 	    break;
7907 #endif
7908 	case VAR_STRING:
7909 	case VAR_FUNC:
7910 	    if (from->vval.v_string == NULL)
7911 		to->vval.v_string = NULL;
7912 	    else
7913 	    {
7914 		to->vval.v_string = vim_strsave(from->vval.v_string);
7915 		if (from->v_type == VAR_FUNC)
7916 		    func_ref(to->vval.v_string);
7917 	    }
7918 	    break;
7919 	case VAR_PARTIAL:
7920 	    if (from->vval.v_partial == NULL)
7921 		to->vval.v_partial = NULL;
7922 	    else
7923 	    {
7924 		to->vval.v_partial = from->vval.v_partial;
7925 		++to->vval.v_partial->pt_refcount;
7926 	    }
7927 	    break;
7928 	case VAR_LIST:
7929 	    if (from->vval.v_list == NULL)
7930 		to->vval.v_list = NULL;
7931 	    else
7932 	    {
7933 		to->vval.v_list = from->vval.v_list;
7934 		++to->vval.v_list->lv_refcount;
7935 	    }
7936 	    break;
7937 	case VAR_DICT:
7938 	    if (from->vval.v_dict == NULL)
7939 		to->vval.v_dict = NULL;
7940 	    else
7941 	    {
7942 		to->vval.v_dict = from->vval.v_dict;
7943 		++to->vval.v_dict->dv_refcount;
7944 	    }
7945 	    break;
7946 	case VAR_UNKNOWN:
7947 	    EMSG2(_(e_intern2), "copy_tv(UNKNOWN)");
7948 	    break;
7949     }
7950 }
7951 
7952 /*
7953  * Make a copy of an item.
7954  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
7955  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
7956  * reference to an already copied list/dict can be used.
7957  * Returns FAIL or OK.
7958  */
7959     int
7960 item_copy(
7961     typval_T	*from,
7962     typval_T	*to,
7963     int		deep,
7964     int		copyID)
7965 {
7966     static int	recurse = 0;
7967     int		ret = OK;
7968 
7969     if (recurse >= DICT_MAXNEST)
7970     {
7971 	EMSG(_("E698: variable nested too deep for making a copy"));
7972 	return FAIL;
7973     }
7974     ++recurse;
7975 
7976     switch (from->v_type)
7977     {
7978 	case VAR_NUMBER:
7979 	case VAR_FLOAT:
7980 	case VAR_STRING:
7981 	case VAR_FUNC:
7982 	case VAR_PARTIAL:
7983 	case VAR_SPECIAL:
7984 	case VAR_JOB:
7985 	case VAR_CHANNEL:
7986 	    copy_tv(from, to);
7987 	    break;
7988 	case VAR_LIST:
7989 	    to->v_type = VAR_LIST;
7990 	    to->v_lock = 0;
7991 	    if (from->vval.v_list == NULL)
7992 		to->vval.v_list = NULL;
7993 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
7994 	    {
7995 		/* use the copy made earlier */
7996 		to->vval.v_list = from->vval.v_list->lv_copylist;
7997 		++to->vval.v_list->lv_refcount;
7998 	    }
7999 	    else
8000 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
8001 	    if (to->vval.v_list == NULL)
8002 		ret = FAIL;
8003 	    break;
8004 	case VAR_DICT:
8005 	    to->v_type = VAR_DICT;
8006 	    to->v_lock = 0;
8007 	    if (from->vval.v_dict == NULL)
8008 		to->vval.v_dict = NULL;
8009 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
8010 	    {
8011 		/* use the copy made earlier */
8012 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
8013 		++to->vval.v_dict->dv_refcount;
8014 	    }
8015 	    else
8016 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
8017 	    if (to->vval.v_dict == NULL)
8018 		ret = FAIL;
8019 	    break;
8020 	case VAR_UNKNOWN:
8021 	    EMSG2(_(e_intern2), "item_copy(UNKNOWN)");
8022 	    ret = FAIL;
8023     }
8024     --recurse;
8025     return ret;
8026 }
8027 
8028 /*
8029  * This function is used by f_input() and f_inputdialog() functions. The third
8030  * argument to f_input() specifies the type of completion to use at the
8031  * prompt. The third argument to f_inputdialog() specifies the value to return
8032  * when the user cancels the prompt.
8033  */
8034     void
8035 get_user_input(
8036     typval_T	*argvars,
8037     typval_T	*rettv,
8038     int		inputdialog,
8039     int		secret)
8040 {
8041     char_u	*prompt = get_tv_string_chk(&argvars[0]);
8042     char_u	*p = NULL;
8043     int		c;
8044     char_u	buf[NUMBUFLEN];
8045     int		cmd_silent_save = cmd_silent;
8046     char_u	*defstr = (char_u *)"";
8047     int		xp_type = EXPAND_NOTHING;
8048     char_u	*xp_arg = NULL;
8049 
8050     rettv->v_type = VAR_STRING;
8051     rettv->vval.v_string = NULL;
8052 
8053 #ifdef NO_CONSOLE_INPUT
8054     /* While starting up, there is no place to enter text. */
8055     if (no_console_input())
8056 	return;
8057 #endif
8058 
8059     cmd_silent = FALSE;		/* Want to see the prompt. */
8060     if (prompt != NULL)
8061     {
8062 	/* Only the part of the message after the last NL is considered as
8063 	 * prompt for the command line */
8064 	p = vim_strrchr(prompt, '\n');
8065 	if (p == NULL)
8066 	    p = prompt;
8067 	else
8068 	{
8069 	    ++p;
8070 	    c = *p;
8071 	    *p = NUL;
8072 	    msg_start();
8073 	    msg_clr_eos();
8074 	    msg_puts_attr(prompt, echo_attr);
8075 	    msg_didout = FALSE;
8076 	    msg_starthere();
8077 	    *p = c;
8078 	}
8079 	cmdline_row = msg_row;
8080 
8081 	if (argvars[1].v_type != VAR_UNKNOWN)
8082 	{
8083 	    defstr = get_tv_string_buf_chk(&argvars[1], buf);
8084 	    if (defstr != NULL)
8085 		stuffReadbuffSpec(defstr);
8086 
8087 	    if (!inputdialog && argvars[2].v_type != VAR_UNKNOWN)
8088 	    {
8089 		char_u	*xp_name;
8090 		int	xp_namelen;
8091 		long	argt;
8092 
8093 		/* input() with a third argument: completion */
8094 		rettv->vval.v_string = NULL;
8095 
8096 		xp_name = get_tv_string_buf_chk(&argvars[2], buf);
8097 		if (xp_name == NULL)
8098 		    return;
8099 
8100 		xp_namelen = (int)STRLEN(xp_name);
8101 
8102 		if (parse_compl_arg(xp_name, xp_namelen, &xp_type, &argt,
8103 							     &xp_arg) == FAIL)
8104 		    return;
8105 	    }
8106 	}
8107 
8108 	if (defstr != NULL)
8109 	{
8110 	    int save_ex_normal_busy = ex_normal_busy;
8111 	    ex_normal_busy = 0;
8112 	    rettv->vval.v_string =
8113 		getcmdline_prompt(secret ? NUL : '@', p, echo_attr,
8114 							      xp_type, xp_arg);
8115 	    ex_normal_busy = save_ex_normal_busy;
8116 	}
8117 	if (inputdialog && rettv->vval.v_string == NULL
8118 		&& argvars[1].v_type != VAR_UNKNOWN
8119 		&& argvars[2].v_type != VAR_UNKNOWN)
8120 	    rettv->vval.v_string = vim_strsave(get_tv_string_buf(
8121 							   &argvars[2], buf));
8122 
8123 	vim_free(xp_arg);
8124 
8125 	/* since the user typed this, no need to wait for return */
8126 	need_wait_return = FALSE;
8127 	msg_didout = FALSE;
8128     }
8129     cmd_silent = cmd_silent_save;
8130 }
8131 
8132 /*
8133  * ":echo expr1 ..."	print each argument separated with a space, add a
8134  *			newline at the end.
8135  * ":echon expr1 ..."	print each argument plain.
8136  */
8137     void
8138 ex_echo(exarg_T *eap)
8139 {
8140     char_u	*arg = eap->arg;
8141     typval_T	rettv;
8142     char_u	*tofree;
8143     char_u	*p;
8144     int		needclr = TRUE;
8145     int		atstart = TRUE;
8146     char_u	numbuf[NUMBUFLEN];
8147 
8148     if (eap->skip)
8149 	++emsg_skip;
8150     while (*arg != NUL && *arg != '|' && *arg != '\n' && !got_int)
8151     {
8152 	/* If eval1() causes an error message the text from the command may
8153 	 * still need to be cleared. E.g., "echo 22,44". */
8154 	need_clr_eos = needclr;
8155 
8156 	p = arg;
8157 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8158 	{
8159 	    /*
8160 	     * Report the invalid expression unless the expression evaluation
8161 	     * has been cancelled due to an aborting error, an interrupt, or an
8162 	     * exception.
8163 	     */
8164 	    if (!aborting())
8165 		EMSG2(_(e_invexpr2), p);
8166 	    need_clr_eos = FALSE;
8167 	    break;
8168 	}
8169 	need_clr_eos = FALSE;
8170 
8171 	if (!eap->skip)
8172 	{
8173 	    if (atstart)
8174 	    {
8175 		atstart = FALSE;
8176 		/* Call msg_start() after eval1(), evaluating the expression
8177 		 * may cause a message to appear. */
8178 		if (eap->cmdidx == CMD_echo)
8179 		{
8180 		    /* Mark the saved text as finishing the line, so that what
8181 		     * follows is displayed on a new line when scrolling back
8182 		     * at the more prompt. */
8183 		    msg_sb_eol();
8184 		    msg_start();
8185 		}
8186 	    }
8187 	    else if (eap->cmdidx == CMD_echo)
8188 		msg_puts_attr((char_u *)" ", echo_attr);
8189 	    p = echo_string(&rettv, &tofree, numbuf, get_copyID());
8190 	    if (p != NULL)
8191 		for ( ; *p != NUL && !got_int; ++p)
8192 		{
8193 		    if (*p == '\n' || *p == '\r' || *p == TAB)
8194 		    {
8195 			if (*p != TAB && needclr)
8196 			{
8197 			    /* remove any text still there from the command */
8198 			    msg_clr_eos();
8199 			    needclr = FALSE;
8200 			}
8201 			msg_putchar_attr(*p, echo_attr);
8202 		    }
8203 		    else
8204 		    {
8205 #ifdef FEAT_MBYTE
8206 			if (has_mbyte)
8207 			{
8208 			    int i = (*mb_ptr2len)(p);
8209 
8210 			    (void)msg_outtrans_len_attr(p, i, echo_attr);
8211 			    p += i - 1;
8212 			}
8213 			else
8214 #endif
8215 			    (void)msg_outtrans_len_attr(p, 1, echo_attr);
8216 		    }
8217 		}
8218 	    vim_free(tofree);
8219 	}
8220 	clear_tv(&rettv);
8221 	arg = skipwhite(arg);
8222     }
8223     eap->nextcmd = check_nextcmd(arg);
8224 
8225     if (eap->skip)
8226 	--emsg_skip;
8227     else
8228     {
8229 	/* remove text that may still be there from the command */
8230 	if (needclr)
8231 	    msg_clr_eos();
8232 	if (eap->cmdidx == CMD_echo)
8233 	    msg_end();
8234     }
8235 }
8236 
8237 /*
8238  * ":echohl {name}".
8239  */
8240     void
8241 ex_echohl(exarg_T *eap)
8242 {
8243     int		id;
8244 
8245     id = syn_name2id(eap->arg);
8246     if (id == 0)
8247 	echo_attr = 0;
8248     else
8249 	echo_attr = syn_id2attr(id);
8250 }
8251 
8252 /*
8253  * ":execute expr1 ..."	execute the result of an expression.
8254  * ":echomsg expr1 ..."	Print a message
8255  * ":echoerr expr1 ..."	Print an error
8256  * Each gets spaces around each argument and a newline at the end for
8257  * echo commands
8258  */
8259     void
8260 ex_execute(exarg_T *eap)
8261 {
8262     char_u	*arg = eap->arg;
8263     typval_T	rettv;
8264     int		ret = OK;
8265     char_u	*p;
8266     garray_T	ga;
8267     int		len;
8268     int		save_did_emsg;
8269 
8270     ga_init2(&ga, 1, 80);
8271 
8272     if (eap->skip)
8273 	++emsg_skip;
8274     while (*arg != NUL && *arg != '|' && *arg != '\n')
8275     {
8276 	p = arg;
8277 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8278 	{
8279 	    /*
8280 	     * Report the invalid expression unless the expression evaluation
8281 	     * has been cancelled due to an aborting error, an interrupt, or an
8282 	     * exception.
8283 	     */
8284 	    if (!aborting())
8285 		EMSG2(_(e_invexpr2), p);
8286 	    ret = FAIL;
8287 	    break;
8288 	}
8289 
8290 	if (!eap->skip)
8291 	{
8292 	    p = get_tv_string(&rettv);
8293 	    len = (int)STRLEN(p);
8294 	    if (ga_grow(&ga, len + 2) == FAIL)
8295 	    {
8296 		clear_tv(&rettv);
8297 		ret = FAIL;
8298 		break;
8299 	    }
8300 	    if (ga.ga_len)
8301 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
8302 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
8303 	    ga.ga_len += len;
8304 	}
8305 
8306 	clear_tv(&rettv);
8307 	arg = skipwhite(arg);
8308     }
8309 
8310     if (ret != FAIL && ga.ga_data != NULL)
8311     {
8312 	if (eap->cmdidx == CMD_echomsg)
8313 	{
8314 	    MSG_ATTR(ga.ga_data, echo_attr);
8315 	    out_flush();
8316 	}
8317 	else if (eap->cmdidx == CMD_echoerr)
8318 	{
8319 	    /* We don't want to abort following commands, restore did_emsg. */
8320 	    save_did_emsg = did_emsg;
8321 	    EMSG((char_u *)ga.ga_data);
8322 	    if (!force_abort)
8323 		did_emsg = save_did_emsg;
8324 	}
8325 	else if (eap->cmdidx == CMD_execute)
8326 	    do_cmdline((char_u *)ga.ga_data,
8327 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
8328     }
8329 
8330     ga_clear(&ga);
8331 
8332     if (eap->skip)
8333 	--emsg_skip;
8334 
8335     eap->nextcmd = check_nextcmd(arg);
8336 }
8337 
8338 /*
8339  * Find window specified by "vp" in tabpage "tp".
8340  */
8341     win_T *
8342 find_win_by_nr(
8343     typval_T	*vp,
8344     tabpage_T	*tp UNUSED)	/* NULL for current tab page */
8345 {
8346 #ifdef FEAT_WINDOWS
8347     win_T	*wp;
8348 #endif
8349     int		nr;
8350 
8351     nr = (int)get_tv_number_chk(vp, NULL);
8352 
8353 #ifdef FEAT_WINDOWS
8354     if (nr < 0)
8355 	return NULL;
8356     if (nr == 0)
8357 	return curwin;
8358 
8359     FOR_ALL_WINDOWS_IN_TAB(tp, wp)
8360     {
8361 	if (nr >= LOWEST_WIN_ID)
8362 	{
8363 	    if (wp->w_id == nr)
8364 		return wp;
8365 	}
8366 	else if (--nr <= 0)
8367 	    break;
8368     }
8369     if (nr >= LOWEST_WIN_ID)
8370 	return NULL;
8371     return wp;
8372 #else
8373     if (nr == 0 || nr == 1 || nr == curwin->w_id)
8374 	return curwin;
8375     return NULL;
8376 #endif
8377 }
8378 
8379 /*
8380  * Find window specified by "wvp" in tabpage "tvp".
8381  */
8382     win_T *
8383 find_tabwin(
8384     typval_T	*wvp,	/* VAR_UNKNOWN for current window */
8385     typval_T	*tvp)	/* VAR_UNKNOWN for current tab page */
8386 {
8387     win_T	*wp = NULL;
8388     tabpage_T	*tp = NULL;
8389     long	n;
8390 
8391     if (wvp->v_type != VAR_UNKNOWN)
8392     {
8393 	if (tvp->v_type != VAR_UNKNOWN)
8394 	{
8395 	    n = (long)get_tv_number(tvp);
8396 	    if (n >= 0)
8397 		tp = find_tabpage(n);
8398 	}
8399 	else
8400 	    tp = curtab;
8401 
8402 	if (tp != NULL)
8403 	    wp = find_win_by_nr(wvp, tp);
8404     }
8405     else
8406 	wp = curwin;
8407 
8408     return wp;
8409 }
8410 
8411 /*
8412  * getwinvar() and gettabwinvar()
8413  */
8414     void
8415 getwinvar(
8416     typval_T	*argvars,
8417     typval_T	*rettv,
8418     int		off)	    /* 1 for gettabwinvar() */
8419 {
8420     win_T	*win;
8421     char_u	*varname;
8422     dictitem_T	*v;
8423     tabpage_T	*tp = NULL;
8424     int		done = FALSE;
8425 #ifdef FEAT_WINDOWS
8426     win_T	*oldcurwin;
8427     tabpage_T	*oldtabpage;
8428     int		need_switch_win;
8429 #endif
8430 
8431 #ifdef FEAT_WINDOWS
8432     if (off == 1)
8433 	tp = find_tabpage((int)get_tv_number_chk(&argvars[0], NULL));
8434     else
8435 	tp = curtab;
8436 #endif
8437     win = find_win_by_nr(&argvars[off], tp);
8438     varname = get_tv_string_chk(&argvars[off + 1]);
8439     ++emsg_off;
8440 
8441     rettv->v_type = VAR_STRING;
8442     rettv->vval.v_string = NULL;
8443 
8444     if (win != NULL && varname != NULL)
8445     {
8446 #ifdef FEAT_WINDOWS
8447 	/* Set curwin to be our win, temporarily.  Also set the tabpage,
8448 	 * otherwise the window is not valid. Only do this when needed,
8449 	 * autocommands get blocked. */
8450 	need_switch_win = !(tp == curtab && win == curwin);
8451 	if (!need_switch_win
8452 		  || switch_win(&oldcurwin, &oldtabpage, win, tp, TRUE) == OK)
8453 #endif
8454 	{
8455 	    if (*varname == '&')	/* window-local-option */
8456 	    {
8457 		if (get_option_tv(&varname, rettv, 1) == OK)
8458 		    done = TRUE;
8459 	    }
8460 	    else
8461 	    {
8462 		/* Look up the variable. */
8463 		/* Let getwinvar({nr}, "") return the "w:" dictionary. */
8464 		v = find_var_in_ht(&win->w_vars->dv_hashtab, 'w',
8465 							      varname, FALSE);
8466 		if (v != NULL)
8467 		{
8468 		    copy_tv(&v->di_tv, rettv);
8469 		    done = TRUE;
8470 		}
8471 	    }
8472 	}
8473 
8474 #ifdef FEAT_WINDOWS
8475 	if (need_switch_win)
8476 	    /* restore previous notion of curwin */
8477 	    restore_win(oldcurwin, oldtabpage, TRUE);
8478 #endif
8479     }
8480 
8481     if (!done && argvars[off + 2].v_type != VAR_UNKNOWN)
8482 	/* use the default return value */
8483 	copy_tv(&argvars[off + 2], rettv);
8484 
8485     --emsg_off;
8486 }
8487 
8488 /*
8489  * "setwinvar()" and "settabwinvar()" functions
8490  */
8491     void
8492 setwinvar(typval_T *argvars, typval_T *rettv UNUSED, int off)
8493 {
8494     win_T	*win;
8495 #ifdef FEAT_WINDOWS
8496     win_T	*save_curwin;
8497     tabpage_T	*save_curtab;
8498     int		need_switch_win;
8499 #endif
8500     char_u	*varname, *winvarname;
8501     typval_T	*varp;
8502     char_u	nbuf[NUMBUFLEN];
8503     tabpage_T	*tp = NULL;
8504 
8505     if (check_restricted() || check_secure())
8506 	return;
8507 
8508 #ifdef FEAT_WINDOWS
8509     if (off == 1)
8510 	tp = find_tabpage((int)get_tv_number_chk(&argvars[0], NULL));
8511     else
8512 	tp = curtab;
8513 #endif
8514     win = find_win_by_nr(&argvars[off], tp);
8515     varname = get_tv_string_chk(&argvars[off + 1]);
8516     varp = &argvars[off + 2];
8517 
8518     if (win != NULL && varname != NULL && varp != NULL)
8519     {
8520 #ifdef FEAT_WINDOWS
8521 	need_switch_win = !(tp == curtab && win == curwin);
8522 	if (!need_switch_win
8523 	       || switch_win(&save_curwin, &save_curtab, win, tp, TRUE) == OK)
8524 #endif
8525 	{
8526 	    if (*varname == '&')
8527 	    {
8528 		long	numval;
8529 		char_u	*strval;
8530 		int		error = FALSE;
8531 
8532 		++varname;
8533 		numval = (long)get_tv_number_chk(varp, &error);
8534 		strval = get_tv_string_buf_chk(varp, nbuf);
8535 		if (!error && strval != NULL)
8536 		    set_option_value(varname, numval, strval, OPT_LOCAL);
8537 	    }
8538 	    else
8539 	    {
8540 		winvarname = alloc((unsigned)STRLEN(varname) + 3);
8541 		if (winvarname != NULL)
8542 		{
8543 		    STRCPY(winvarname, "w:");
8544 		    STRCPY(winvarname + 2, varname);
8545 		    set_var(winvarname, varp, TRUE);
8546 		    vim_free(winvarname);
8547 		}
8548 	    }
8549 	}
8550 #ifdef FEAT_WINDOWS
8551 	if (need_switch_win)
8552 	    restore_win(save_curwin, save_curtab, TRUE);
8553 #endif
8554     }
8555 }
8556 
8557 /*
8558  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
8559  * "arg" points to the "&" or '+' when called, to "option" when returning.
8560  * Returns NULL when no option name found.  Otherwise pointer to the char
8561  * after the option name.
8562  */
8563     static char_u *
8564 find_option_end(char_u **arg, int *opt_flags)
8565 {
8566     char_u	*p = *arg;
8567 
8568     ++p;
8569     if (*p == 'g' && p[1] == ':')
8570     {
8571 	*opt_flags = OPT_GLOBAL;
8572 	p += 2;
8573     }
8574     else if (*p == 'l' && p[1] == ':')
8575     {
8576 	*opt_flags = OPT_LOCAL;
8577 	p += 2;
8578     }
8579     else
8580 	*opt_flags = 0;
8581 
8582     if (!ASCII_ISALPHA(*p))
8583 	return NULL;
8584     *arg = p;
8585 
8586     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
8587 	p += 4;	    /* termcap option */
8588     else
8589 	while (ASCII_ISALPHA(*p))
8590 	    ++p;
8591     return p;
8592 }
8593 
8594 /*
8595  * Return the autoload script name for a function or variable name.
8596  * Returns NULL when out of memory.
8597  */
8598     char_u *
8599 autoload_name(char_u *name)
8600 {
8601     char_u	*p;
8602     char_u	*scriptname;
8603 
8604     /* Get the script file name: replace '#' with '/', append ".vim". */
8605     scriptname = alloc((unsigned)(STRLEN(name) + 14));
8606     if (scriptname == NULL)
8607 	return FALSE;
8608     STRCPY(scriptname, "autoload/");
8609     STRCAT(scriptname, name);
8610     *vim_strrchr(scriptname, AUTOLOAD_CHAR) = NUL;
8611     STRCAT(scriptname, ".vim");
8612     while ((p = vim_strchr(scriptname, AUTOLOAD_CHAR)) != NULL)
8613 	*p = '/';
8614     return scriptname;
8615 }
8616 
8617 /*
8618  * If "name" has a package name try autoloading the script for it.
8619  * Return TRUE if a package was loaded.
8620  */
8621     int
8622 script_autoload(
8623     char_u	*name,
8624     int		reload)	    /* load script again when already loaded */
8625 {
8626     char_u	*p;
8627     char_u	*scriptname, *tofree;
8628     int		ret = FALSE;
8629     int		i;
8630 
8631     /* If there is no '#' after name[0] there is no package name. */
8632     p = vim_strchr(name, AUTOLOAD_CHAR);
8633     if (p == NULL || p == name)
8634 	return FALSE;
8635 
8636     tofree = scriptname = autoload_name(name);
8637 
8638     /* Find the name in the list of previously loaded package names.  Skip
8639      * "autoload/", it's always the same. */
8640     for (i = 0; i < ga_loaded.ga_len; ++i)
8641 	if (STRCMP(((char_u **)ga_loaded.ga_data)[i] + 9, scriptname + 9) == 0)
8642 	    break;
8643     if (!reload && i < ga_loaded.ga_len)
8644 	ret = FALSE;	    /* was loaded already */
8645     else
8646     {
8647 	/* Remember the name if it wasn't loaded already. */
8648 	if (i == ga_loaded.ga_len && ga_grow(&ga_loaded, 1) == OK)
8649 	{
8650 	    ((char_u **)ga_loaded.ga_data)[ga_loaded.ga_len++] = scriptname;
8651 	    tofree = NULL;
8652 	}
8653 
8654 	/* Try loading the package from $VIMRUNTIME/autoload/<name>.vim */
8655 	if (source_runtime(scriptname, 0) == OK)
8656 	    ret = TRUE;
8657     }
8658 
8659     vim_free(tofree);
8660     return ret;
8661 }
8662 
8663 #if defined(FEAT_VIMINFO) || defined(FEAT_SESSION)
8664 typedef enum
8665 {
8666     VAR_FLAVOUR_DEFAULT,	/* doesn't start with uppercase */
8667     VAR_FLAVOUR_SESSION,	/* starts with uppercase, some lower */
8668     VAR_FLAVOUR_VIMINFO		/* all uppercase */
8669 } var_flavour_T;
8670 
8671 static var_flavour_T var_flavour(char_u *varname);
8672 
8673     static var_flavour_T
8674 var_flavour(char_u *varname)
8675 {
8676     char_u *p = varname;
8677 
8678     if (ASCII_ISUPPER(*p))
8679     {
8680 	while (*(++p))
8681 	    if (ASCII_ISLOWER(*p))
8682 		return VAR_FLAVOUR_SESSION;
8683 	return VAR_FLAVOUR_VIMINFO;
8684     }
8685     else
8686 	return VAR_FLAVOUR_DEFAULT;
8687 }
8688 #endif
8689 
8690 #if defined(FEAT_VIMINFO) || defined(PROTO)
8691 /*
8692  * Restore global vars that start with a capital from the viminfo file
8693  */
8694     int
8695 read_viminfo_varlist(vir_T *virp, int writing)
8696 {
8697     char_u	*tab;
8698     int		type = VAR_NUMBER;
8699     typval_T	tv;
8700     void	*save_funccal;
8701 
8702     if (!writing && (find_viminfo_parameter('!') != NULL))
8703     {
8704 	tab = vim_strchr(virp->vir_line + 1, '\t');
8705 	if (tab != NULL)
8706 	{
8707 	    *tab++ = '\0';	/* isolate the variable name */
8708 	    switch (*tab)
8709 	    {
8710 		case 'S': type = VAR_STRING; break;
8711 #ifdef FEAT_FLOAT
8712 		case 'F': type = VAR_FLOAT; break;
8713 #endif
8714 		case 'D': type = VAR_DICT; break;
8715 		case 'L': type = VAR_LIST; break;
8716 		case 'X': type = VAR_SPECIAL; break;
8717 	    }
8718 
8719 	    tab = vim_strchr(tab, '\t');
8720 	    if (tab != NULL)
8721 	    {
8722 		tv.v_type = type;
8723 		if (type == VAR_STRING || type == VAR_DICT || type == VAR_LIST)
8724 		    tv.vval.v_string = viminfo_readstring(virp,
8725 				       (int)(tab - virp->vir_line + 1), TRUE);
8726 #ifdef FEAT_FLOAT
8727 		else if (type == VAR_FLOAT)
8728 		    (void)string2float(tab + 1, &tv.vval.v_float);
8729 #endif
8730 		else
8731 		    tv.vval.v_number = atol((char *)tab + 1);
8732 		if (type == VAR_DICT || type == VAR_LIST)
8733 		{
8734 		    typval_T *etv = eval_expr(tv.vval.v_string, NULL);
8735 
8736 		    if (etv == NULL)
8737 			/* Failed to parse back the dict or list, use it as a
8738 			 * string. */
8739 			tv.v_type = VAR_STRING;
8740 		    else
8741 		    {
8742 			vim_free(tv.vval.v_string);
8743 			tv = *etv;
8744 			vim_free(etv);
8745 		    }
8746 		}
8747 
8748 		/* when in a function use global variables */
8749 		save_funccal = clear_current_funccal();
8750 		set_var(virp->vir_line + 1, &tv, FALSE);
8751 		restore_current_funccal(save_funccal);
8752 
8753 		if (tv.v_type == VAR_STRING)
8754 		    vim_free(tv.vval.v_string);
8755 		else if (tv.v_type == VAR_DICT || tv.v_type == VAR_LIST)
8756 		    clear_tv(&tv);
8757 	    }
8758 	}
8759     }
8760 
8761     return viminfo_readline(virp);
8762 }
8763 
8764 /*
8765  * Write global vars that start with a capital to the viminfo file
8766  */
8767     void
8768 write_viminfo_varlist(FILE *fp)
8769 {
8770     hashitem_T	*hi;
8771     dictitem_T	*this_var;
8772     int		todo;
8773     char	*s = "";
8774     char_u	*p;
8775     char_u	*tofree;
8776     char_u	numbuf[NUMBUFLEN];
8777 
8778     if (find_viminfo_parameter('!') == NULL)
8779 	return;
8780 
8781     fputs(_("\n# global variables:\n"), fp);
8782 
8783     todo = (int)globvarht.ht_used;
8784     for (hi = globvarht.ht_array; todo > 0; ++hi)
8785     {
8786 	if (!HASHITEM_EMPTY(hi))
8787 	{
8788 	    --todo;
8789 	    this_var = HI2DI(hi);
8790 	    if (var_flavour(this_var->di_key) == VAR_FLAVOUR_VIMINFO)
8791 	    {
8792 		switch (this_var->di_tv.v_type)
8793 		{
8794 		    case VAR_STRING: s = "STR"; break;
8795 		    case VAR_NUMBER: s = "NUM"; break;
8796 		    case VAR_FLOAT:  s = "FLO"; break;
8797 		    case VAR_DICT:   s = "DIC"; break;
8798 		    case VAR_LIST:   s = "LIS"; break;
8799 		    case VAR_SPECIAL: s = "XPL"; break;
8800 
8801 		    case VAR_UNKNOWN:
8802 		    case VAR_FUNC:
8803 		    case VAR_PARTIAL:
8804 		    case VAR_JOB:
8805 		    case VAR_CHANNEL:
8806 				     continue;
8807 		}
8808 		fprintf(fp, "!%s\t%s\t", this_var->di_key, s);
8809 		p = echo_string(&this_var->di_tv, &tofree, numbuf, 0);
8810 		if (p != NULL)
8811 		    viminfo_writestring(fp, p);
8812 		vim_free(tofree);
8813 	    }
8814 	}
8815     }
8816 }
8817 #endif
8818 
8819 #if defined(FEAT_SESSION) || defined(PROTO)
8820     int
8821 store_session_globals(FILE *fd)
8822 {
8823     hashitem_T	*hi;
8824     dictitem_T	*this_var;
8825     int		todo;
8826     char_u	*p, *t;
8827 
8828     todo = (int)globvarht.ht_used;
8829     for (hi = globvarht.ht_array; todo > 0; ++hi)
8830     {
8831 	if (!HASHITEM_EMPTY(hi))
8832 	{
8833 	    --todo;
8834 	    this_var = HI2DI(hi);
8835 	    if ((this_var->di_tv.v_type == VAR_NUMBER
8836 			|| this_var->di_tv.v_type == VAR_STRING)
8837 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
8838 	    {
8839 		/* Escape special characters with a backslash.  Turn a LF and
8840 		 * CR into \n and \r. */
8841 		p = vim_strsave_escaped(get_tv_string(&this_var->di_tv),
8842 							(char_u *)"\\\"\n\r");
8843 		if (p == NULL)	    /* out of memory */
8844 		    break;
8845 		for (t = p; *t != NUL; ++t)
8846 		    if (*t == '\n')
8847 			*t = 'n';
8848 		    else if (*t == '\r')
8849 			*t = 'r';
8850 		if ((fprintf(fd, "let %s = %c%s%c",
8851 				this_var->di_key,
8852 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
8853 									: ' ',
8854 				p,
8855 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
8856 								   : ' ') < 0)
8857 			|| put_eol(fd) == FAIL)
8858 		{
8859 		    vim_free(p);
8860 		    return FAIL;
8861 		}
8862 		vim_free(p);
8863 	    }
8864 #ifdef FEAT_FLOAT
8865 	    else if (this_var->di_tv.v_type == VAR_FLOAT
8866 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
8867 	    {
8868 		float_T f = this_var->di_tv.vval.v_float;
8869 		int sign = ' ';
8870 
8871 		if (f < 0)
8872 		{
8873 		    f = -f;
8874 		    sign = '-';
8875 		}
8876 		if ((fprintf(fd, "let %s = %c%f",
8877 					       this_var->di_key, sign, f) < 0)
8878 			|| put_eol(fd) == FAIL)
8879 		    return FAIL;
8880 	    }
8881 #endif
8882 	}
8883     }
8884     return OK;
8885 }
8886 #endif
8887 
8888 /*
8889  * Display script name where an item was last set.
8890  * Should only be invoked when 'verbose' is non-zero.
8891  */
8892     void
8893 last_set_msg(scid_T scriptID)
8894 {
8895     char_u *p;
8896 
8897     if (scriptID != 0)
8898     {
8899 	p = home_replace_save(NULL, get_scriptname(scriptID));
8900 	if (p != NULL)
8901 	{
8902 	    verbose_enter();
8903 	    MSG_PUTS(_("\n\tLast set from "));
8904 	    MSG_PUTS(p);
8905 	    vim_free(p);
8906 	    verbose_leave();
8907 	}
8908     }
8909 }
8910 
8911 /*
8912  * List v:oldfiles in a nice way.
8913  */
8914     void
8915 ex_oldfiles(exarg_T *eap UNUSED)
8916 {
8917     list_T	*l = vimvars[VV_OLDFILES].vv_list;
8918     listitem_T	*li;
8919     int		nr = 0;
8920 
8921     if (l == NULL)
8922 	msg((char_u *)_("No old files"));
8923     else
8924     {
8925 	msg_start();
8926 	msg_scroll = TRUE;
8927 	for (li = l->lv_first; li != NULL && !got_int; li = li->li_next)
8928 	{
8929 	    msg_outnum((long)++nr);
8930 	    MSG_PUTS(": ");
8931 	    msg_outtrans(get_tv_string(&li->li_tv));
8932 	    msg_putchar('\n');
8933 	    out_flush();	    /* output one line at a time */
8934 	    ui_breakcheck();
8935 	}
8936 	/* Assume "got_int" was set to truncate the listing. */
8937 	got_int = FALSE;
8938 
8939 #ifdef FEAT_BROWSE_CMD
8940 	if (cmdmod.browse)
8941 	{
8942 	    quit_more = FALSE;
8943 	    nr = prompt_for_number(FALSE);
8944 	    msg_starthere();
8945 	    if (nr > 0)
8946 	    {
8947 		char_u *p = list_find_str(get_vim_var_list(VV_OLDFILES),
8948 								    (long)nr);
8949 
8950 		if (p != NULL)
8951 		{
8952 		    p = expand_env_save(p);
8953 		    eap->arg = p;
8954 		    eap->cmdidx = CMD_edit;
8955 		    cmdmod.browse = FALSE;
8956 		    do_exedit(eap, NULL);
8957 		    vim_free(p);
8958 		}
8959 	    }
8960 	}
8961 #endif
8962     }
8963 }
8964 
8965 /* reset v:option_new, v:option_old and v:option_type */
8966     void
8967 reset_v_option_vars(void)
8968 {
8969     set_vim_var_string(VV_OPTION_NEW,  NULL, -1);
8970     set_vim_var_string(VV_OPTION_OLD,  NULL, -1);
8971     set_vim_var_string(VV_OPTION_TYPE, NULL, -1);
8972 }
8973 
8974 /*
8975  * Prepare "gap" for an assert error and add the sourcing position.
8976  */
8977     void
8978 prepare_assert_error(garray_T *gap)
8979 {
8980     char buf[NUMBUFLEN];
8981 
8982     ga_init2(gap, 1, 100);
8983     if (sourcing_name != NULL)
8984     {
8985 	ga_concat(gap, sourcing_name);
8986 	if (sourcing_lnum > 0)
8987 	    ga_concat(gap, (char_u *)" ");
8988     }
8989     if (sourcing_lnum > 0)
8990     {
8991 	sprintf(buf, "line %ld", (long)sourcing_lnum);
8992 	ga_concat(gap, (char_u *)buf);
8993     }
8994     if (sourcing_name != NULL || sourcing_lnum > 0)
8995 	ga_concat(gap, (char_u *)": ");
8996 }
8997 
8998 /*
8999  * Add an assert error to v:errors.
9000  */
9001     void
9002 assert_error(garray_T *gap)
9003 {
9004     struct vimvar   *vp = &vimvars[VV_ERRORS];
9005 
9006     if (vp->vv_type != VAR_LIST || vimvars[VV_ERRORS].vv_list == NULL)
9007 	/* Make sure v:errors is a list. */
9008 	set_vim_var_list(VV_ERRORS, list_alloc());
9009     list_append_string(vimvars[VV_ERRORS].vv_list, gap->ga_data, gap->ga_len);
9010 }
9011 
9012     void
9013 assert_equal_common(typval_T *argvars, assert_type_T atype)
9014 {
9015     garray_T	ga;
9016 
9017     if (tv_equal(&argvars[0], &argvars[1], FALSE, FALSE)
9018 						   != (atype == ASSERT_EQUAL))
9019     {
9020 	prepare_assert_error(&ga);
9021 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
9022 								       atype);
9023 	assert_error(&ga);
9024 	ga_clear(&ga);
9025     }
9026 }
9027 
9028     void
9029 assert_match_common(typval_T *argvars, assert_type_T atype)
9030 {
9031     garray_T	ga;
9032     char_u	buf1[NUMBUFLEN];
9033     char_u	buf2[NUMBUFLEN];
9034     char_u	*pat = get_tv_string_buf_chk(&argvars[0], buf1);
9035     char_u	*text = get_tv_string_buf_chk(&argvars[1], buf2);
9036 
9037     if (pat == NULL || text == NULL)
9038 	EMSG(_(e_invarg));
9039     else if (pattern_match(pat, text, FALSE) != (atype == ASSERT_MATCH))
9040     {
9041 	prepare_assert_error(&ga);
9042 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
9043 									atype);
9044 	assert_error(&ga);
9045 	ga_clear(&ga);
9046     }
9047 }
9048 
9049     void
9050 assert_inrange(typval_T *argvars)
9051 {
9052     garray_T	ga;
9053     int		error = FALSE;
9054     varnumber_T	lower = get_tv_number_chk(&argvars[0], &error);
9055     varnumber_T	upper = get_tv_number_chk(&argvars[1], &error);
9056     varnumber_T	actual = get_tv_number_chk(&argvars[2], &error);
9057     char_u	*tofree;
9058     char	msg[200];
9059     char_u	numbuf[NUMBUFLEN];
9060 
9061     if (error)
9062 	return;
9063     if (actual < lower || actual > upper)
9064     {
9065 	prepare_assert_error(&ga);
9066 	if (argvars[3].v_type != VAR_UNKNOWN)
9067 	{
9068 	    ga_concat(&ga, tv2string(&argvars[3], &tofree, numbuf, 0));
9069 	    vim_free(tofree);
9070 	}
9071 	else
9072 	{
9073 	    vim_snprintf(msg, 200, "Expected range %ld - %ld, but got %ld",
9074 				       (long)lower, (long)upper, (long)actual);
9075 	    ga_concat(&ga, (char_u *)msg);
9076 	}
9077 	assert_error(&ga);
9078 	ga_clear(&ga);
9079     }
9080 }
9081 
9082 /*
9083  * Common for assert_true() and assert_false().
9084  */
9085     void
9086 assert_bool(typval_T *argvars, int isTrue)
9087 {
9088     int		error = FALSE;
9089     garray_T	ga;
9090 
9091     if (argvars[0].v_type == VAR_SPECIAL
9092 	    && argvars[0].vval.v_number == (isTrue ? VVAL_TRUE : VVAL_FALSE))
9093 	return;
9094     if (argvars[0].v_type != VAR_NUMBER
9095 	    || (get_tv_number_chk(&argvars[0], &error) == 0) == isTrue
9096 	    || error)
9097     {
9098 	prepare_assert_error(&ga);
9099 	fill_assert_error(&ga, &argvars[1],
9100 		(char_u *)(isTrue ? "True" : "False"),
9101 		NULL, &argvars[0], ASSERT_OTHER);
9102 	assert_error(&ga);
9103 	ga_clear(&ga);
9104     }
9105 }
9106 
9107     void
9108 assert_exception(typval_T *argvars)
9109 {
9110     garray_T	ga;
9111     char_u	*error = get_tv_string_chk(&argvars[0]);
9112 
9113     if (vimvars[VV_EXCEPTION].vv_str == NULL)
9114     {
9115 	prepare_assert_error(&ga);
9116 	ga_concat(&ga, (char_u *)"v:exception is not set");
9117 	assert_error(&ga);
9118 	ga_clear(&ga);
9119     }
9120     else if (error != NULL
9121 	&& strstr((char *)vimvars[VV_EXCEPTION].vv_str, (char *)error) == NULL)
9122     {
9123 	prepare_assert_error(&ga);
9124 	fill_assert_error(&ga, &argvars[1], NULL, &argvars[0],
9125 				  &vimvars[VV_EXCEPTION].vv_tv, ASSERT_OTHER);
9126 	assert_error(&ga);
9127 	ga_clear(&ga);
9128     }
9129 }
9130 
9131     void
9132 assert_fails(typval_T *argvars)
9133 {
9134     char_u	*cmd = get_tv_string_chk(&argvars[0]);
9135     garray_T	ga;
9136 
9137     called_emsg = FALSE;
9138     suppress_errthrow = TRUE;
9139     emsg_silent = TRUE;
9140     do_cmdline_cmd(cmd);
9141     if (!called_emsg)
9142     {
9143 	prepare_assert_error(&ga);
9144 	ga_concat(&ga, (char_u *)"command did not fail: ");
9145 	ga_concat(&ga, cmd);
9146 	assert_error(&ga);
9147 	ga_clear(&ga);
9148     }
9149     else if (argvars[1].v_type != VAR_UNKNOWN)
9150     {
9151 	char_u	buf[NUMBUFLEN];
9152 	char	*error = (char *)get_tv_string_buf_chk(&argvars[1], buf);
9153 
9154 	if (error == NULL
9155 		  || strstr((char *)vimvars[VV_ERRMSG].vv_str, error) == NULL)
9156 	{
9157 	    prepare_assert_error(&ga);
9158 	    fill_assert_error(&ga, &argvars[2], NULL, &argvars[1],
9159 				     &vimvars[VV_ERRMSG].vv_tv, ASSERT_OTHER);
9160 	    assert_error(&ga);
9161 	    ga_clear(&ga);
9162 	}
9163     }
9164 
9165     called_emsg = FALSE;
9166     suppress_errthrow = FALSE;
9167     emsg_silent = FALSE;
9168     emsg_on_display = FALSE;
9169     set_vim_var_string(VV_ERRMSG, NULL, 0);
9170 }
9171 
9172 /*
9173  * Append "str" to "gap", escaping unprintable characters.
9174  * Changes NL to \n, CR to \r, etc.
9175  */
9176     static void
9177 ga_concat_esc(garray_T *gap, char_u *str)
9178 {
9179     char_u  *p;
9180     char_u  buf[NUMBUFLEN];
9181 
9182     if (str == NULL)
9183     {
9184 	ga_concat(gap, (char_u *)"NULL");
9185 	return;
9186     }
9187 
9188     for (p = str; *p != NUL; ++p)
9189 	switch (*p)
9190 	{
9191 	    case BS: ga_concat(gap, (char_u *)"\\b"); break;
9192 	    case ESC: ga_concat(gap, (char_u *)"\\e"); break;
9193 	    case FF: ga_concat(gap, (char_u *)"\\f"); break;
9194 	    case NL: ga_concat(gap, (char_u *)"\\n"); break;
9195 	    case TAB: ga_concat(gap, (char_u *)"\\t"); break;
9196 	    case CAR: ga_concat(gap, (char_u *)"\\r"); break;
9197 	    case '\\': ga_concat(gap, (char_u *)"\\\\"); break;
9198 	    default:
9199 		if (*p < ' ')
9200 		{
9201 		    vim_snprintf((char *)buf, NUMBUFLEN, "\\x%02x", *p);
9202 		    ga_concat(gap, buf);
9203 		}
9204 		else
9205 		    ga_append(gap, *p);
9206 		break;
9207 	}
9208 }
9209 
9210 /*
9211  * Fill "gap" with information about an assert error.
9212  */
9213     void
9214 fill_assert_error(
9215     garray_T	*gap,
9216     typval_T	*opt_msg_tv,
9217     char_u      *exp_str,
9218     typval_T	*exp_tv,
9219     typval_T	*got_tv,
9220     assert_type_T atype)
9221 {
9222     char_u	numbuf[NUMBUFLEN];
9223     char_u	*tofree;
9224 
9225     if (opt_msg_tv->v_type != VAR_UNKNOWN)
9226     {
9227 	ga_concat(gap, tv2string(opt_msg_tv, &tofree, numbuf, 0));
9228 	vim_free(tofree);
9229     }
9230     else
9231     {
9232 	if (atype == ASSERT_MATCH || atype == ASSERT_NOTMATCH)
9233 	    ga_concat(gap, (char_u *)"Pattern ");
9234 	else
9235 	    ga_concat(gap, (char_u *)"Expected ");
9236 	if (exp_str == NULL)
9237 	{
9238 	    ga_concat_esc(gap, tv2string(exp_tv, &tofree, numbuf, 0));
9239 	    vim_free(tofree);
9240 	}
9241 	else
9242 	    ga_concat_esc(gap, exp_str);
9243 	if (atype == ASSERT_MATCH)
9244 	    ga_concat(gap, (char_u *)" does not match ");
9245 	else if (atype == ASSERT_NOTMATCH)
9246 	    ga_concat(gap, (char_u *)" does match ");
9247 	else if (atype == ASSERT_NOTEQUAL)
9248 	    ga_concat(gap, (char_u *)" differs from ");
9249 	else
9250 	    ga_concat(gap, (char_u *)" but got ");
9251 	ga_concat_esc(gap, tv2string(got_tv, &tofree, numbuf, 0));
9252 	vim_free(tofree);
9253     }
9254 }
9255 
9256 
9257 #endif /* FEAT_EVAL */
9258 
9259 
9260 #if defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) || defined(PROTO)
9261 
9262 #ifdef WIN3264
9263 /*
9264  * Functions for ":8" filename modifier: get 8.3 version of a filename.
9265  */
9266 static int get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen);
9267 static int shortpath_for_invalid_fname(char_u **fname, char_u **bufp, int *fnamelen);
9268 static int shortpath_for_partial(char_u **fnamep, char_u **bufp, int *fnamelen);
9269 
9270 /*
9271  * Get the short path (8.3) for the filename in "fnamep".
9272  * Only works for a valid file name.
9273  * When the path gets longer "fnamep" is changed and the allocated buffer
9274  * is put in "bufp".
9275  * *fnamelen is the length of "fnamep" and set to 0 for a nonexistent path.
9276  * Returns OK on success, FAIL on failure.
9277  */
9278     static int
9279 get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen)
9280 {
9281     int		l, len;
9282     char_u	*newbuf;
9283 
9284     len = *fnamelen;
9285     l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, len);
9286     if (l > len - 1)
9287     {
9288 	/* If that doesn't work (not enough space), then save the string
9289 	 * and try again with a new buffer big enough. */
9290 	newbuf = vim_strnsave(*fnamep, l);
9291 	if (newbuf == NULL)
9292 	    return FAIL;
9293 
9294 	vim_free(*bufp);
9295 	*fnamep = *bufp = newbuf;
9296 
9297 	/* Really should always succeed, as the buffer is big enough. */
9298 	l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, l+1);
9299     }
9300 
9301     *fnamelen = l;
9302     return OK;
9303 }
9304 
9305 /*
9306  * Get the short path (8.3) for the filename in "fname". The converted
9307  * path is returned in "bufp".
9308  *
9309  * Some of the directories specified in "fname" may not exist. This function
9310  * will shorten the existing directories at the beginning of the path and then
9311  * append the remaining non-existing path.
9312  *
9313  * fname - Pointer to the filename to shorten.  On return, contains the
9314  *	   pointer to the shortened pathname
9315  * bufp -  Pointer to an allocated buffer for the filename.
9316  * fnamelen - Length of the filename pointed to by fname
9317  *
9318  * Returns OK on success (or nothing done) and FAIL on failure (out of memory).
9319  */
9320     static int
9321 shortpath_for_invalid_fname(
9322     char_u	**fname,
9323     char_u	**bufp,
9324     int		*fnamelen)
9325 {
9326     char_u	*short_fname, *save_fname, *pbuf_unused;
9327     char_u	*endp, *save_endp;
9328     char_u	ch;
9329     int		old_len, len;
9330     int		new_len, sfx_len;
9331     int		retval = OK;
9332 
9333     /* Make a copy */
9334     old_len = *fnamelen;
9335     save_fname = vim_strnsave(*fname, old_len);
9336     pbuf_unused = NULL;
9337     short_fname = NULL;
9338 
9339     endp = save_fname + old_len - 1; /* Find the end of the copy */
9340     save_endp = endp;
9341 
9342     /*
9343      * Try shortening the supplied path till it succeeds by removing one
9344      * directory at a time from the tail of the path.
9345      */
9346     len = 0;
9347     for (;;)
9348     {
9349 	/* go back one path-separator */
9350 	while (endp > save_fname && !after_pathsep(save_fname, endp + 1))
9351 	    --endp;
9352 	if (endp <= save_fname)
9353 	    break;		/* processed the complete path */
9354 
9355 	/*
9356 	 * Replace the path separator with a NUL and try to shorten the
9357 	 * resulting path.
9358 	 */
9359 	ch = *endp;
9360 	*endp = 0;
9361 	short_fname = save_fname;
9362 	len = (int)STRLEN(short_fname) + 1;
9363 	if (get_short_pathname(&short_fname, &pbuf_unused, &len) == FAIL)
9364 	{
9365 	    retval = FAIL;
9366 	    goto theend;
9367 	}
9368 	*endp = ch;	/* preserve the string */
9369 
9370 	if (len > 0)
9371 	    break;	/* successfully shortened the path */
9372 
9373 	/* failed to shorten the path. Skip the path separator */
9374 	--endp;
9375     }
9376 
9377     if (len > 0)
9378     {
9379 	/*
9380 	 * Succeeded in shortening the path. Now concatenate the shortened
9381 	 * path with the remaining path at the tail.
9382 	 */
9383 
9384 	/* Compute the length of the new path. */
9385 	sfx_len = (int)(save_endp - endp) + 1;
9386 	new_len = len + sfx_len;
9387 
9388 	*fnamelen = new_len;
9389 	vim_free(*bufp);
9390 	if (new_len > old_len)
9391 	{
9392 	    /* There is not enough space in the currently allocated string,
9393 	     * copy it to a buffer big enough. */
9394 	    *fname = *bufp = vim_strnsave(short_fname, new_len);
9395 	    if (*fname == NULL)
9396 	    {
9397 		retval = FAIL;
9398 		goto theend;
9399 	    }
9400 	}
9401 	else
9402 	{
9403 	    /* Transfer short_fname to the main buffer (it's big enough),
9404 	     * unless get_short_pathname() did its work in-place. */
9405 	    *fname = *bufp = save_fname;
9406 	    if (short_fname != save_fname)
9407 		vim_strncpy(save_fname, short_fname, len);
9408 	    save_fname = NULL;
9409 	}
9410 
9411 	/* concat the not-shortened part of the path */
9412 	vim_strncpy(*fname + len, endp, sfx_len);
9413 	(*fname)[new_len] = NUL;
9414     }
9415 
9416 theend:
9417     vim_free(pbuf_unused);
9418     vim_free(save_fname);
9419 
9420     return retval;
9421 }
9422 
9423 /*
9424  * Get a pathname for a partial path.
9425  * Returns OK for success, FAIL for failure.
9426  */
9427     static int
9428 shortpath_for_partial(
9429     char_u	**fnamep,
9430     char_u	**bufp,
9431     int		*fnamelen)
9432 {
9433     int		sepcount, len, tflen;
9434     char_u	*p;
9435     char_u	*pbuf, *tfname;
9436     int		hasTilde;
9437 
9438     /* Count up the path separators from the RHS.. so we know which part
9439      * of the path to return. */
9440     sepcount = 0;
9441     for (p = *fnamep; p < *fnamep + *fnamelen; mb_ptr_adv(p))
9442 	if (vim_ispathsep(*p))
9443 	    ++sepcount;
9444 
9445     /* Need full path first (use expand_env() to remove a "~/") */
9446     hasTilde = (**fnamep == '~');
9447     if (hasTilde)
9448 	pbuf = tfname = expand_env_save(*fnamep);
9449     else
9450 	pbuf = tfname = FullName_save(*fnamep, FALSE);
9451 
9452     len = tflen = (int)STRLEN(tfname);
9453 
9454     if (get_short_pathname(&tfname, &pbuf, &len) == FAIL)
9455 	return FAIL;
9456 
9457     if (len == 0)
9458     {
9459 	/* Don't have a valid filename, so shorten the rest of the
9460 	 * path if we can. This CAN give us invalid 8.3 filenames, but
9461 	 * there's not a lot of point in guessing what it might be.
9462 	 */
9463 	len = tflen;
9464 	if (shortpath_for_invalid_fname(&tfname, &pbuf, &len) == FAIL)
9465 	    return FAIL;
9466     }
9467 
9468     /* Count the paths backward to find the beginning of the desired string. */
9469     for (p = tfname + len - 1; p >= tfname; --p)
9470     {
9471 #ifdef FEAT_MBYTE
9472 	if (has_mbyte)
9473 	    p -= mb_head_off(tfname, p);
9474 #endif
9475 	if (vim_ispathsep(*p))
9476 	{
9477 	    if (sepcount == 0 || (hasTilde && sepcount == 1))
9478 		break;
9479 	    else
9480 		sepcount --;
9481 	}
9482     }
9483     if (hasTilde)
9484     {
9485 	--p;
9486 	if (p >= tfname)
9487 	    *p = '~';
9488 	else
9489 	    return FAIL;
9490     }
9491     else
9492 	++p;
9493 
9494     /* Copy in the string - p indexes into tfname - allocated at pbuf */
9495     vim_free(*bufp);
9496     *fnamelen = (int)STRLEN(p);
9497     *bufp = pbuf;
9498     *fnamep = p;
9499 
9500     return OK;
9501 }
9502 #endif /* WIN3264 */
9503 
9504 /*
9505  * Adjust a filename, according to a string of modifiers.
9506  * *fnamep must be NUL terminated when called.  When returning, the length is
9507  * determined by *fnamelen.
9508  * Returns VALID_ flags or -1 for failure.
9509  * When there is an error, *fnamep is set to NULL.
9510  */
9511     int
9512 modify_fname(
9513     char_u	*src,		/* string with modifiers */
9514     int		*usedlen,	/* characters after src that are used */
9515     char_u	**fnamep,	/* file name so far */
9516     char_u	**bufp,		/* buffer for allocated file name or NULL */
9517     int		*fnamelen)	/* length of fnamep */
9518 {
9519     int		valid = 0;
9520     char_u	*tail;
9521     char_u	*s, *p, *pbuf;
9522     char_u	dirname[MAXPATHL];
9523     int		c;
9524     int		has_fullname = 0;
9525 #ifdef WIN3264
9526     char_u	*fname_start = *fnamep;
9527     int		has_shortname = 0;
9528 #endif
9529 
9530 repeat:
9531     /* ":p" - full path/file_name */
9532     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'p')
9533     {
9534 	has_fullname = 1;
9535 
9536 	valid |= VALID_PATH;
9537 	*usedlen += 2;
9538 
9539 	/* Expand "~/path" for all systems and "~user/path" for Unix and VMS */
9540 	if ((*fnamep)[0] == '~'
9541 #if !defined(UNIX) && !(defined(VMS) && defined(USER_HOME))
9542 		&& ((*fnamep)[1] == '/'
9543 # ifdef BACKSLASH_IN_FILENAME
9544 		    || (*fnamep)[1] == '\\'
9545 # endif
9546 		    || (*fnamep)[1] == NUL)
9547 
9548 #endif
9549 	   )
9550 	{
9551 	    *fnamep = expand_env_save(*fnamep);
9552 	    vim_free(*bufp);	/* free any allocated file name */
9553 	    *bufp = *fnamep;
9554 	    if (*fnamep == NULL)
9555 		return -1;
9556 	}
9557 
9558 	/* When "/." or "/.." is used: force expansion to get rid of it. */
9559 	for (p = *fnamep; *p != NUL; mb_ptr_adv(p))
9560 	{
9561 	    if (vim_ispathsep(*p)
9562 		    && p[1] == '.'
9563 		    && (p[2] == NUL
9564 			|| vim_ispathsep(p[2])
9565 			|| (p[2] == '.'
9566 			    && (p[3] == NUL || vim_ispathsep(p[3])))))
9567 		break;
9568 	}
9569 
9570 	/* FullName_save() is slow, don't use it when not needed. */
9571 	if (*p != NUL || !vim_isAbsName(*fnamep))
9572 	{
9573 	    *fnamep = FullName_save(*fnamep, *p != NUL);
9574 	    vim_free(*bufp);	/* free any allocated file name */
9575 	    *bufp = *fnamep;
9576 	    if (*fnamep == NULL)
9577 		return -1;
9578 	}
9579 
9580 #ifdef WIN3264
9581 # if _WIN32_WINNT >= 0x0500
9582 	if (vim_strchr(*fnamep, '~') != NULL)
9583 	{
9584 	    /* Expand 8.3 filename to full path.  Needed to make sure the same
9585 	     * file does not have two different names.
9586 	     * Note: problem does not occur if _WIN32_WINNT < 0x0500. */
9587 	    p = alloc(_MAX_PATH + 1);
9588 	    if (p != NULL)
9589 	    {
9590 		if (GetLongPathName((LPSTR)*fnamep, (LPSTR)p, _MAX_PATH))
9591 		{
9592 		    vim_free(*bufp);
9593 		    *bufp = *fnamep = p;
9594 		}
9595 		else
9596 		    vim_free(p);
9597 	    }
9598 	}
9599 # endif
9600 #endif
9601 	/* Append a path separator to a directory. */
9602 	if (mch_isdir(*fnamep))
9603 	{
9604 	    /* Make room for one or two extra characters. */
9605 	    *fnamep = vim_strnsave(*fnamep, (int)STRLEN(*fnamep) + 2);
9606 	    vim_free(*bufp);	/* free any allocated file name */
9607 	    *bufp = *fnamep;
9608 	    if (*fnamep == NULL)
9609 		return -1;
9610 	    add_pathsep(*fnamep);
9611 	}
9612     }
9613 
9614     /* ":." - path relative to the current directory */
9615     /* ":~" - path relative to the home directory */
9616     /* ":8" - shortname path - postponed till after */
9617     while (src[*usedlen] == ':'
9618 		  && ((c = src[*usedlen + 1]) == '.' || c == '~' || c == '8'))
9619     {
9620 	*usedlen += 2;
9621 	if (c == '8')
9622 	{
9623 #ifdef WIN3264
9624 	    has_shortname = 1; /* Postpone this. */
9625 #endif
9626 	    continue;
9627 	}
9628 	pbuf = NULL;
9629 	/* Need full path first (use expand_env() to remove a "~/") */
9630 	if (!has_fullname)
9631 	{
9632 	    if (c == '.' && **fnamep == '~')
9633 		p = pbuf = expand_env_save(*fnamep);
9634 	    else
9635 		p = pbuf = FullName_save(*fnamep, FALSE);
9636 	}
9637 	else
9638 	    p = *fnamep;
9639 
9640 	has_fullname = 0;
9641 
9642 	if (p != NULL)
9643 	{
9644 	    if (c == '.')
9645 	    {
9646 		mch_dirname(dirname, MAXPATHL);
9647 		s = shorten_fname(p, dirname);
9648 		if (s != NULL)
9649 		{
9650 		    *fnamep = s;
9651 		    if (pbuf != NULL)
9652 		    {
9653 			vim_free(*bufp);   /* free any allocated file name */
9654 			*bufp = pbuf;
9655 			pbuf = NULL;
9656 		    }
9657 		}
9658 	    }
9659 	    else
9660 	    {
9661 		home_replace(NULL, p, dirname, MAXPATHL, TRUE);
9662 		/* Only replace it when it starts with '~' */
9663 		if (*dirname == '~')
9664 		{
9665 		    s = vim_strsave(dirname);
9666 		    if (s != NULL)
9667 		    {
9668 			*fnamep = s;
9669 			vim_free(*bufp);
9670 			*bufp = s;
9671 		    }
9672 		}
9673 	    }
9674 	    vim_free(pbuf);
9675 	}
9676     }
9677 
9678     tail = gettail(*fnamep);
9679     *fnamelen = (int)STRLEN(*fnamep);
9680 
9681     /* ":h" - head, remove "/file_name", can be repeated  */
9682     /* Don't remove the first "/" or "c:\" */
9683     while (src[*usedlen] == ':' && src[*usedlen + 1] == 'h')
9684     {
9685 	valid |= VALID_HEAD;
9686 	*usedlen += 2;
9687 	s = get_past_head(*fnamep);
9688 	while (tail > s && after_pathsep(s, tail))
9689 	    mb_ptr_back(*fnamep, tail);
9690 	*fnamelen = (int)(tail - *fnamep);
9691 #ifdef VMS
9692 	if (*fnamelen > 0)
9693 	    *fnamelen += 1; /* the path separator is part of the path */
9694 #endif
9695 	if (*fnamelen == 0)
9696 	{
9697 	    /* Result is empty.  Turn it into "." to make ":cd %:h" work. */
9698 	    p = vim_strsave((char_u *)".");
9699 	    if (p == NULL)
9700 		return -1;
9701 	    vim_free(*bufp);
9702 	    *bufp = *fnamep = tail = p;
9703 	    *fnamelen = 1;
9704 	}
9705 	else
9706 	{
9707 	    while (tail > s && !after_pathsep(s, tail))
9708 		mb_ptr_back(*fnamep, tail);
9709 	}
9710     }
9711 
9712     /* ":8" - shortname  */
9713     if (src[*usedlen] == ':' && src[*usedlen + 1] == '8')
9714     {
9715 	*usedlen += 2;
9716 #ifdef WIN3264
9717 	has_shortname = 1;
9718 #endif
9719     }
9720 
9721 #ifdef WIN3264
9722     /*
9723      * Handle ":8" after we have done 'heads' and before we do 'tails'.
9724      */
9725     if (has_shortname)
9726     {
9727 	/* Copy the string if it is shortened by :h and when it wasn't copied
9728 	 * yet, because we are going to change it in place.  Avoids changing
9729 	 * the buffer name for "%:8". */
9730 	if (*fnamelen < (int)STRLEN(*fnamep) || *fnamep == fname_start)
9731 	{
9732 	    p = vim_strnsave(*fnamep, *fnamelen);
9733 	    if (p == NULL)
9734 		return -1;
9735 	    vim_free(*bufp);
9736 	    *bufp = *fnamep = p;
9737 	}
9738 
9739 	/* Split into two implementations - makes it easier.  First is where
9740 	 * there isn't a full name already, second is where there is. */
9741 	if (!has_fullname && !vim_isAbsName(*fnamep))
9742 	{
9743 	    if (shortpath_for_partial(fnamep, bufp, fnamelen) == FAIL)
9744 		return -1;
9745 	}
9746 	else
9747 	{
9748 	    int		l = *fnamelen;
9749 
9750 	    /* Simple case, already have the full-name.
9751 	     * Nearly always shorter, so try first time. */
9752 	    if (get_short_pathname(fnamep, bufp, &l) == FAIL)
9753 		return -1;
9754 
9755 	    if (l == 0)
9756 	    {
9757 		/* Couldn't find the filename, search the paths. */
9758 		l = *fnamelen;
9759 		if (shortpath_for_invalid_fname(fnamep, bufp, &l) == FAIL)
9760 		    return -1;
9761 	    }
9762 	    *fnamelen = l;
9763 	}
9764     }
9765 #endif /* WIN3264 */
9766 
9767     /* ":t" - tail, just the basename */
9768     if (src[*usedlen] == ':' && src[*usedlen + 1] == 't')
9769     {
9770 	*usedlen += 2;
9771 	*fnamelen -= (int)(tail - *fnamep);
9772 	*fnamep = tail;
9773     }
9774 
9775     /* ":e" - extension, can be repeated */
9776     /* ":r" - root, without extension, can be repeated */
9777     while (src[*usedlen] == ':'
9778 	    && (src[*usedlen + 1] == 'e' || src[*usedlen + 1] == 'r'))
9779     {
9780 	/* find a '.' in the tail:
9781 	 * - for second :e: before the current fname
9782 	 * - otherwise: The last '.'
9783 	 */
9784 	if (src[*usedlen + 1] == 'e' && *fnamep > tail)
9785 	    s = *fnamep - 2;
9786 	else
9787 	    s = *fnamep + *fnamelen - 1;
9788 	for ( ; s > tail; --s)
9789 	    if (s[0] == '.')
9790 		break;
9791 	if (src[*usedlen + 1] == 'e')		/* :e */
9792 	{
9793 	    if (s > tail)
9794 	    {
9795 		*fnamelen += (int)(*fnamep - (s + 1));
9796 		*fnamep = s + 1;
9797 #ifdef VMS
9798 		/* cut version from the extension */
9799 		s = *fnamep + *fnamelen - 1;
9800 		for ( ; s > *fnamep; --s)
9801 		    if (s[0] == ';')
9802 			break;
9803 		if (s > *fnamep)
9804 		    *fnamelen = s - *fnamep;
9805 #endif
9806 	    }
9807 	    else if (*fnamep <= tail)
9808 		*fnamelen = 0;
9809 	}
9810 	else				/* :r */
9811 	{
9812 	    if (s > tail)	/* remove one extension */
9813 		*fnamelen = (int)(s - *fnamep);
9814 	}
9815 	*usedlen += 2;
9816     }
9817 
9818     /* ":s?pat?foo?" - substitute */
9819     /* ":gs?pat?foo?" - global substitute */
9820     if (src[*usedlen] == ':'
9821 	    && (src[*usedlen + 1] == 's'
9822 		|| (src[*usedlen + 1] == 'g' && src[*usedlen + 2] == 's')))
9823     {
9824 	char_u	    *str;
9825 	char_u	    *pat;
9826 	char_u	    *sub;
9827 	int	    sep;
9828 	char_u	    *flags;
9829 	int	    didit = FALSE;
9830 
9831 	flags = (char_u *)"";
9832 	s = src + *usedlen + 2;
9833 	if (src[*usedlen + 1] == 'g')
9834 	{
9835 	    flags = (char_u *)"g";
9836 	    ++s;
9837 	}
9838 
9839 	sep = *s++;
9840 	if (sep)
9841 	{
9842 	    /* find end of pattern */
9843 	    p = vim_strchr(s, sep);
9844 	    if (p != NULL)
9845 	    {
9846 		pat = vim_strnsave(s, (int)(p - s));
9847 		if (pat != NULL)
9848 		{
9849 		    s = p + 1;
9850 		    /* find end of substitution */
9851 		    p = vim_strchr(s, sep);
9852 		    if (p != NULL)
9853 		    {
9854 			sub = vim_strnsave(s, (int)(p - s));
9855 			str = vim_strnsave(*fnamep, *fnamelen);
9856 			if (sub != NULL && str != NULL)
9857 			{
9858 			    *usedlen = (int)(p + 1 - src);
9859 			    s = do_string_sub(str, pat, sub, NULL, flags);
9860 			    if (s != NULL)
9861 			    {
9862 				*fnamep = s;
9863 				*fnamelen = (int)STRLEN(s);
9864 				vim_free(*bufp);
9865 				*bufp = s;
9866 				didit = TRUE;
9867 			    }
9868 			}
9869 			vim_free(sub);
9870 			vim_free(str);
9871 		    }
9872 		    vim_free(pat);
9873 		}
9874 	    }
9875 	    /* after using ":s", repeat all the modifiers */
9876 	    if (didit)
9877 		goto repeat;
9878 	}
9879     }
9880 
9881     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'S')
9882     {
9883 	/* vim_strsave_shellescape() needs a NUL terminated string. */
9884 	c = (*fnamep)[*fnamelen];
9885 	if (c != NUL)
9886 	    (*fnamep)[*fnamelen] = NUL;
9887 	p = vim_strsave_shellescape(*fnamep, FALSE, FALSE);
9888 	if (c != NUL)
9889 	    (*fnamep)[*fnamelen] = c;
9890 	if (p == NULL)
9891 	    return -1;
9892 	vim_free(*bufp);
9893 	*bufp = *fnamep = p;
9894 	*fnamelen = (int)STRLEN(p);
9895 	*usedlen += 2;
9896     }
9897 
9898     return valid;
9899 }
9900 
9901 /*
9902  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
9903  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
9904  * "flags" can be "g" to do a global substitute.
9905  * Returns an allocated string, NULL for error.
9906  */
9907     char_u *
9908 do_string_sub(
9909     char_u	*str,
9910     char_u	*pat,
9911     char_u	*sub,
9912     typval_T	*expr,
9913     char_u	*flags)
9914 {
9915     int		sublen;
9916     regmatch_T	regmatch;
9917     int		i;
9918     int		do_all;
9919     char_u	*tail;
9920     char_u	*end;
9921     garray_T	ga;
9922     char_u	*ret;
9923     char_u	*save_cpo;
9924     char_u	*zero_width = NULL;
9925 
9926     /* Make 'cpoptions' empty, so that the 'l' flag doesn't work here */
9927     save_cpo = p_cpo;
9928     p_cpo = empty_option;
9929 
9930     ga_init2(&ga, 1, 200);
9931 
9932     do_all = (flags[0] == 'g');
9933 
9934     regmatch.rm_ic = p_ic;
9935     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
9936     if (regmatch.regprog != NULL)
9937     {
9938 	tail = str;
9939 	end = str + STRLEN(str);
9940 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
9941 	{
9942 	    /* Skip empty match except for first match. */
9943 	    if (regmatch.startp[0] == regmatch.endp[0])
9944 	    {
9945 		if (zero_width == regmatch.startp[0])
9946 		{
9947 		    /* avoid getting stuck on a match with an empty string */
9948 		    i = MB_PTR2LEN(tail);
9949 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
9950 								   (size_t)i);
9951 		    ga.ga_len += i;
9952 		    tail += i;
9953 		    continue;
9954 		}
9955 		zero_width = regmatch.startp[0];
9956 	    }
9957 
9958 	    /*
9959 	     * Get some space for a temporary buffer to do the substitution
9960 	     * into.  It will contain:
9961 	     * - The text up to where the match is.
9962 	     * - The substituted text.
9963 	     * - The text after the match.
9964 	     */
9965 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
9966 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
9967 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
9968 	    {
9969 		ga_clear(&ga);
9970 		break;
9971 	    }
9972 
9973 	    /* copy the text up to where the match is */
9974 	    i = (int)(regmatch.startp[0] - tail);
9975 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
9976 	    /* add the substituted text */
9977 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
9978 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
9979 	    ga.ga_len += i + sublen - 1;
9980 	    tail = regmatch.endp[0];
9981 	    if (*tail == NUL)
9982 		break;
9983 	    if (!do_all)
9984 		break;
9985 	}
9986 
9987 	if (ga.ga_data != NULL)
9988 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
9989 
9990 	vim_regfree(regmatch.regprog);
9991     }
9992 
9993     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
9994     ga_clear(&ga);
9995     if (p_cpo == empty_option)
9996 	p_cpo = save_cpo;
9997     else
9998 	/* Darn, evaluating {sub} expression or {expr} changed the value. */
9999 	free_string_option(save_cpo);
10000 
10001     return ret;
10002 }
10003 
10004     static int
10005 filter_map_one(typval_T *tv, typval_T *expr, int map, int *remp)
10006 {
10007     typval_T	rettv;
10008     typval_T	argv[3];
10009     char_u	buf[NUMBUFLEN];
10010     char_u	*s;
10011     int		retval = FAIL;
10012     int		dummy;
10013 
10014     copy_tv(tv, &vimvars[VV_VAL].vv_tv);
10015     argv[0] = vimvars[VV_KEY].vv_tv;
10016     argv[1] = vimvars[VV_VAL].vv_tv;
10017     if (expr->v_type == VAR_FUNC)
10018     {
10019 	s = expr->vval.v_string;
10020 	if (call_func(s, (int)STRLEN(s), &rettv, 2, argv, NULL,
10021 				     0L, 0L, &dummy, TRUE, NULL, NULL) == FAIL)
10022 	    goto theend;
10023     }
10024     else if (expr->v_type == VAR_PARTIAL)
10025     {
10026 	partial_T   *partial = expr->vval.v_partial;
10027 
10028 	s = partial->pt_name;
10029 	if (call_func(s, (int)STRLEN(s), &rettv, 2, argv, NULL,
10030 				  0L, 0L, &dummy, TRUE, partial, NULL) == FAIL)
10031 	    goto theend;
10032     }
10033     else
10034     {
10035 	s = get_tv_string_buf_chk(expr, buf);
10036 	if (s == NULL)
10037 	    goto theend;
10038 	s = skipwhite(s);
10039 	if (eval1(&s, &rettv, TRUE) == FAIL)
10040 	    goto theend;
10041 	if (*s != NUL)  /* check for trailing chars after expr */
10042 	{
10043 	    EMSG2(_(e_invexpr2), s);
10044 	    goto theend;
10045 	}
10046     }
10047     if (map)
10048     {
10049 	/* map(): replace the list item value */
10050 	clear_tv(tv);
10051 	rettv.v_lock = 0;
10052 	*tv = rettv;
10053     }
10054     else
10055     {
10056 	int	    error = FALSE;
10057 
10058 	/* filter(): when expr is zero remove the item */
10059 	*remp = (get_tv_number_chk(&rettv, &error) == 0);
10060 	clear_tv(&rettv);
10061 	/* On type error, nothing has been removed; return FAIL to stop the
10062 	 * loop.  The error message was given by get_tv_number_chk(). */
10063 	if (error)
10064 	    goto theend;
10065     }
10066     retval = OK;
10067 theend:
10068     clear_tv(&vimvars[VV_VAL].vv_tv);
10069     return retval;
10070 }
10071 
10072 
10073 /*
10074  * Implementation of map() and filter().
10075  */
10076     void
10077 filter_map(typval_T *argvars, typval_T *rettv, int map)
10078 {
10079     typval_T	*expr;
10080     listitem_T	*li, *nli;
10081     list_T	*l = NULL;
10082     dictitem_T	*di;
10083     hashtab_T	*ht;
10084     hashitem_T	*hi;
10085     dict_T	*d = NULL;
10086     typval_T	save_val;
10087     typval_T	save_key;
10088     int		rem;
10089     int		todo;
10090     char_u	*ermsg = (char_u *)(map ? "map()" : "filter()");
10091     char_u	*arg_errmsg = (char_u *)(map ? N_("map() argument")
10092 				   : N_("filter() argument"));
10093     int		save_did_emsg;
10094     int		idx = 0;
10095 
10096     if (argvars[0].v_type == VAR_LIST)
10097     {
10098 	if ((l = argvars[0].vval.v_list) == NULL
10099 	      || (!map && tv_check_lock(l->lv_lock, arg_errmsg, TRUE)))
10100 	    return;
10101     }
10102     else if (argvars[0].v_type == VAR_DICT)
10103     {
10104 	if ((d = argvars[0].vval.v_dict) == NULL
10105 	      || (!map && tv_check_lock(d->dv_lock, arg_errmsg, TRUE)))
10106 	    return;
10107     }
10108     else
10109     {
10110 	EMSG2(_(e_listdictarg), ermsg);
10111 	return;
10112     }
10113 
10114     expr = &argvars[1];
10115     /* On type errors, the preceding call has already displayed an error
10116      * message.  Avoid a misleading error message for an empty string that
10117      * was not passed as argument. */
10118     if (expr->v_type != VAR_UNKNOWN)
10119     {
10120 	prepare_vimvar(VV_VAL, &save_val);
10121 
10122 	/* We reset "did_emsg" to be able to detect whether an error
10123 	 * occurred during evaluation of the expression. */
10124 	save_did_emsg = did_emsg;
10125 	did_emsg = FALSE;
10126 
10127 	prepare_vimvar(VV_KEY, &save_key);
10128 	if (argvars[0].v_type == VAR_DICT)
10129 	{
10130 	    vimvars[VV_KEY].vv_type = VAR_STRING;
10131 
10132 	    ht = &d->dv_hashtab;
10133 	    hash_lock(ht);
10134 	    todo = (int)ht->ht_used;
10135 	    for (hi = ht->ht_array; todo > 0; ++hi)
10136 	    {
10137 		if (!HASHITEM_EMPTY(hi))
10138 		{
10139 		    int r;
10140 
10141 		    --todo;
10142 		    di = HI2DI(hi);
10143 		    if (map &&
10144 			    (tv_check_lock(di->di_tv.v_lock, arg_errmsg, TRUE)
10145 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE)))
10146 			break;
10147 		    vimvars[VV_KEY].vv_str = vim_strsave(di->di_key);
10148 		    r = filter_map_one(&di->di_tv, expr, map, &rem);
10149 		    clear_tv(&vimvars[VV_KEY].vv_tv);
10150 		    if (r == FAIL || did_emsg)
10151 			break;
10152 		    if (!map && rem)
10153 		    {
10154 			if (var_check_fixed(di->di_flags, arg_errmsg, TRUE)
10155 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE))
10156 			    break;
10157 			dictitem_remove(d, di);
10158 		    }
10159 		}
10160 	    }
10161 	    hash_unlock(ht);
10162 	}
10163 	else
10164 	{
10165 	    vimvars[VV_KEY].vv_type = VAR_NUMBER;
10166 
10167 	    for (li = l->lv_first; li != NULL; li = nli)
10168 	    {
10169 		if (map && tv_check_lock(li->li_tv.v_lock, arg_errmsg, TRUE))
10170 		    break;
10171 		nli = li->li_next;
10172 		vimvars[VV_KEY].vv_nr = idx;
10173 		if (filter_map_one(&li->li_tv, expr, map, &rem) == FAIL
10174 								  || did_emsg)
10175 		    break;
10176 		if (!map && rem)
10177 		    listitem_remove(l, li);
10178 		++idx;
10179 	    }
10180 	}
10181 
10182 	restore_vimvar(VV_KEY, &save_key);
10183 	restore_vimvar(VV_VAL, &save_val);
10184 
10185 	did_emsg |= save_did_emsg;
10186     }
10187 
10188     copy_tv(&argvars[0], rettv);
10189 }
10190 
10191 #endif /* defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) */
10192