xref: /vim-8.2.3635/src/eval.c (revision cd5c8f82)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * eval.c: Expression evaluation.
12  */
13 #define USING_FLOAT_STUFF
14 
15 #include "vim.h"
16 
17 #if defined(FEAT_EVAL) || defined(PROTO)
18 
19 #ifdef VMS
20 # include <float.h>
21 #endif
22 
23 #define DICT_MAXNEST 100	/* maximum nesting of lists and dicts */
24 
25 static char *e_letunexp	= N_("E18: Unexpected characters in :let");
26 static char *e_undefvar = N_("E121: Undefined variable: %s");
27 static char *e_missbrac = N_("E111: Missing ']'");
28 static char *e_dictrange = N_("E719: Cannot use [:] with a Dictionary");
29 static char *e_letwrong = N_("E734: Wrong variable type for %s=");
30 static char *e_illvar = N_("E461: Illegal variable name: %s");
31 #ifdef FEAT_FLOAT
32 static char *e_float_as_string = N_("E806: using Float as a String");
33 #endif
34 
35 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
36 
37 static dictitem_T	globvars_var;		/* variable used for g: */
38 #define globvarht globvardict.dv_hashtab
39 
40 /*
41  * Old Vim variables such as "v:version" are also available without the "v:".
42  * Also in functions.  We need a special hashtable for them.
43  */
44 static hashtab_T	compat_hashtab;
45 
46 /*
47  * When recursively copying lists and dicts we need to remember which ones we
48  * have done to avoid endless recursiveness.  This unique ID is used for that.
49  * The last bit is used for previous_funccal, ignored when comparing.
50  */
51 static int current_copyID = 0;
52 
53 /*
54  * Array to hold the hashtab with variables local to each sourced script.
55  * Each item holds a variable (nameless) that points to the dict_T.
56  */
57 typedef struct
58 {
59     dictitem_T	sv_var;
60     dict_T	sv_dict;
61 } scriptvar_T;
62 
63 static garray_T	    ga_scripts = {0, 0, sizeof(scriptvar_T *), 4, NULL};
64 #define SCRIPT_SV(id) (((scriptvar_T **)ga_scripts.ga_data)[(id) - 1])
65 #define SCRIPT_VARS(id) (SCRIPT_SV(id)->sv_dict.dv_hashtab)
66 
67 static int echo_attr = 0;   /* attributes used for ":echo" */
68 
69 /* The names of packages that once were loaded are remembered. */
70 static garray_T		ga_loaded = {0, 0, sizeof(char_u *), 4, NULL};
71 
72 /*
73  * Info used by a ":for" loop.
74  */
75 typedef struct
76 {
77     int		fi_semicolon;	/* TRUE if ending in '; var]' */
78     int		fi_varcount;	/* nr of variables in the list */
79     listwatch_T	fi_lw;		/* keep an eye on the item used. */
80     list_T	*fi_list;	/* list being used */
81 } forinfo_T;
82 
83 
84 /*
85  * Array to hold the value of v: variables.
86  * The value is in a dictitem, so that it can also be used in the v: scope.
87  * The reason to use this table anyway is for very quick access to the
88  * variables with the VV_ defines.
89  */
90 
91 /* values for vv_flags: */
92 #define VV_COMPAT	1	/* compatible, also used without "v:" */
93 #define VV_RO		2	/* read-only */
94 #define VV_RO_SBX	4	/* read-only in the sandbox */
95 
96 #define VV_NAME(s, t)	s, {{t, 0, {0}}, 0, {0}}
97 
98 static struct vimvar
99 {
100     char	*vv_name;	/* name of variable, without v: */
101     dictitem16_T vv_di;		/* value and name for key (max 16 chars!) */
102     char	vv_flags;	/* VV_COMPAT, VV_RO, VV_RO_SBX */
103 } vimvars[VV_LEN] =
104 {
105     /*
106      * The order here must match the VV_ defines in vim.h!
107      * Initializing a union does not work, leave tv.vval empty to get zero's.
108      */
109     {VV_NAME("count",		 VAR_NUMBER), VV_COMPAT+VV_RO},
110     {VV_NAME("count1",		 VAR_NUMBER), VV_RO},
111     {VV_NAME("prevcount",	 VAR_NUMBER), VV_RO},
112     {VV_NAME("errmsg",		 VAR_STRING), VV_COMPAT},
113     {VV_NAME("warningmsg",	 VAR_STRING), 0},
114     {VV_NAME("statusmsg",	 VAR_STRING), 0},
115     {VV_NAME("shell_error",	 VAR_NUMBER), VV_COMPAT+VV_RO},
116     {VV_NAME("this_session",	 VAR_STRING), VV_COMPAT},
117     {VV_NAME("version",		 VAR_NUMBER), VV_COMPAT+VV_RO},
118     {VV_NAME("lnum",		 VAR_NUMBER), VV_RO_SBX},
119     {VV_NAME("termresponse",	 VAR_STRING), VV_RO},
120     {VV_NAME("fname",		 VAR_STRING), VV_RO},
121     {VV_NAME("lang",		 VAR_STRING), VV_RO},
122     {VV_NAME("lc_time",		 VAR_STRING), VV_RO},
123     {VV_NAME("ctype",		 VAR_STRING), VV_RO},
124     {VV_NAME("charconvert_from", VAR_STRING), VV_RO},
125     {VV_NAME("charconvert_to",	 VAR_STRING), VV_RO},
126     {VV_NAME("fname_in",	 VAR_STRING), VV_RO},
127     {VV_NAME("fname_out",	 VAR_STRING), VV_RO},
128     {VV_NAME("fname_new",	 VAR_STRING), VV_RO},
129     {VV_NAME("fname_diff",	 VAR_STRING), VV_RO},
130     {VV_NAME("cmdarg",		 VAR_STRING), VV_RO},
131     {VV_NAME("foldstart",	 VAR_NUMBER), VV_RO_SBX},
132     {VV_NAME("foldend",		 VAR_NUMBER), VV_RO_SBX},
133     {VV_NAME("folddashes",	 VAR_STRING), VV_RO_SBX},
134     {VV_NAME("foldlevel",	 VAR_NUMBER), VV_RO_SBX},
135     {VV_NAME("progname",	 VAR_STRING), VV_RO},
136     {VV_NAME("servername",	 VAR_STRING), VV_RO},
137     {VV_NAME("dying",		 VAR_NUMBER), VV_RO},
138     {VV_NAME("exception",	 VAR_STRING), VV_RO},
139     {VV_NAME("throwpoint",	 VAR_STRING), VV_RO},
140     {VV_NAME("register",	 VAR_STRING), VV_RO},
141     {VV_NAME("cmdbang",		 VAR_NUMBER), VV_RO},
142     {VV_NAME("insertmode",	 VAR_STRING), VV_RO},
143     {VV_NAME("val",		 VAR_UNKNOWN), VV_RO},
144     {VV_NAME("key",		 VAR_UNKNOWN), VV_RO},
145     {VV_NAME("profiling",	 VAR_NUMBER), VV_RO},
146     {VV_NAME("fcs_reason",	 VAR_STRING), VV_RO},
147     {VV_NAME("fcs_choice",	 VAR_STRING), 0},
148     {VV_NAME("beval_bufnr",	 VAR_NUMBER), VV_RO},
149     {VV_NAME("beval_winnr",	 VAR_NUMBER), VV_RO},
150     {VV_NAME("beval_winid",	 VAR_NUMBER), VV_RO},
151     {VV_NAME("beval_lnum",	 VAR_NUMBER), VV_RO},
152     {VV_NAME("beval_col",	 VAR_NUMBER), VV_RO},
153     {VV_NAME("beval_text",	 VAR_STRING), VV_RO},
154     {VV_NAME("scrollstart",	 VAR_STRING), 0},
155     {VV_NAME("swapname",	 VAR_STRING), VV_RO},
156     {VV_NAME("swapchoice",	 VAR_STRING), 0},
157     {VV_NAME("swapcommand",	 VAR_STRING), VV_RO},
158     {VV_NAME("char",		 VAR_STRING), 0},
159     {VV_NAME("mouse_win",	 VAR_NUMBER), 0},
160     {VV_NAME("mouse_winid",	 VAR_NUMBER), 0},
161     {VV_NAME("mouse_lnum",	 VAR_NUMBER), 0},
162     {VV_NAME("mouse_col",	 VAR_NUMBER), 0},
163     {VV_NAME("operator",	 VAR_STRING), VV_RO},
164     {VV_NAME("searchforward",	 VAR_NUMBER), 0},
165     {VV_NAME("hlsearch",	 VAR_NUMBER), 0},
166     {VV_NAME("oldfiles",	 VAR_LIST), 0},
167     {VV_NAME("windowid",	 VAR_NUMBER), VV_RO},
168     {VV_NAME("progpath",	 VAR_STRING), VV_RO},
169     {VV_NAME("completed_item",	 VAR_DICT), VV_RO},
170     {VV_NAME("option_new",	 VAR_STRING), VV_RO},
171     {VV_NAME("option_old",	 VAR_STRING), VV_RO},
172     {VV_NAME("option_type",	 VAR_STRING), VV_RO},
173     {VV_NAME("errors",		 VAR_LIST), 0},
174     {VV_NAME("false",		 VAR_SPECIAL), VV_RO},
175     {VV_NAME("true",		 VAR_SPECIAL), VV_RO},
176     {VV_NAME("null",		 VAR_SPECIAL), VV_RO},
177     {VV_NAME("none",		 VAR_SPECIAL), VV_RO},
178     {VV_NAME("vim_did_enter",	 VAR_NUMBER), VV_RO},
179     {VV_NAME("testing",		 VAR_NUMBER), 0},
180     {VV_NAME("t_number",	 VAR_NUMBER), VV_RO},
181     {VV_NAME("t_string",	 VAR_NUMBER), VV_RO},
182     {VV_NAME("t_func",		 VAR_NUMBER), VV_RO},
183     {VV_NAME("t_list",		 VAR_NUMBER), VV_RO},
184     {VV_NAME("t_dict",		 VAR_NUMBER), VV_RO},
185     {VV_NAME("t_float",		 VAR_NUMBER), VV_RO},
186     {VV_NAME("t_bool",		 VAR_NUMBER), VV_RO},
187     {VV_NAME("t_none",		 VAR_NUMBER), VV_RO},
188     {VV_NAME("t_job",		 VAR_NUMBER), VV_RO},
189     {VV_NAME("t_channel",	 VAR_NUMBER), VV_RO},
190 };
191 
192 /* shorthand */
193 #define vv_type		vv_di.di_tv.v_type
194 #define vv_nr		vv_di.di_tv.vval.v_number
195 #define vv_float	vv_di.di_tv.vval.v_float
196 #define vv_str		vv_di.di_tv.vval.v_string
197 #define vv_list		vv_di.di_tv.vval.v_list
198 #define vv_dict		vv_di.di_tv.vval.v_dict
199 #define vv_tv		vv_di.di_tv
200 
201 static dictitem_T	vimvars_var;		/* variable used for v: */
202 #define vimvarht  vimvardict.dv_hashtab
203 
204 static int ex_let_vars(char_u *arg, typval_T *tv, int copy, int semicolon, int var_count, char_u *nextchars);
205 static char_u *skip_var_list(char_u *arg, int *var_count, int *semicolon);
206 static char_u *skip_var_one(char_u *arg);
207 static void list_glob_vars(int *first);
208 static void list_buf_vars(int *first);
209 static void list_win_vars(int *first);
210 #ifdef FEAT_WINDOWS
211 static void list_tab_vars(int *first);
212 #endif
213 static void list_vim_vars(int *first);
214 static void list_script_vars(int *first);
215 static char_u *list_arg_vars(exarg_T *eap, char_u *arg, int *first);
216 static char_u *ex_let_one(char_u *arg, typval_T *tv, int copy, char_u *endchars, char_u *op);
217 static void set_var_lval(lval_T *lp, char_u *endp, typval_T *rettv, int copy, char_u *op);
218 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
219 static void ex_unletlock(exarg_T *eap, char_u *argstart, int deep);
220 static int do_unlet_var(lval_T *lp, char_u *name_end, int forceit);
221 static int do_lock_var(lval_T *lp, char_u *name_end, int deep, int lock);
222 static void item_lock(typval_T *tv, int deep, int lock);
223 
224 static int eval2(char_u **arg, typval_T *rettv, int evaluate);
225 static int eval3(char_u **arg, typval_T *rettv, int evaluate);
226 static int eval4(char_u **arg, typval_T *rettv, int evaluate);
227 static int eval5(char_u **arg, typval_T *rettv, int evaluate);
228 static int eval6(char_u **arg, typval_T *rettv, int evaluate, int want_string);
229 static int eval7(char_u **arg, typval_T *rettv, int evaluate, int want_string);
230 
231 static int eval_index(char_u **arg, typval_T *rettv, int evaluate, int verbose);
232 static int get_string_tv(char_u **arg, typval_T *rettv, int evaluate);
233 static int get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate);
234 static int free_unref_items(int copyID);
235 static int get_env_tv(char_u **arg, typval_T *rettv, int evaluate);
236 static int get_env_len(char_u **arg);
237 static char_u * make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
238 static void check_vars(char_u *name, int len);
239 static typval_T *alloc_string_tv(char_u *string);
240 static void delete_var(hashtab_T *ht, hashitem_T *hi);
241 static void list_one_var(dictitem_T *v, char_u *prefix, int *first);
242 static void list_one_var_a(char_u *prefix, char_u *name, int type, char_u *string, int *first);
243 static char_u *find_option_end(char_u **arg, int *opt_flags);
244 
245 /* for VIM_VERSION_ defines */
246 #include "version.h"
247 
248 
249 #if defined(EBCDIC) || defined(PROTO)
250 /*
251  * Compare struct fst by function name.
252  */
253     static int
254 compare_func_name(const void *s1, const void *s2)
255 {
256     struct fst *p1 = (struct fst *)s1;
257     struct fst *p2 = (struct fst *)s2;
258 
259     return STRCMP(p1->f_name, p2->f_name);
260 }
261 
262 /*
263  * Sort the function table by function name.
264  * The sorting of the table above is ASCII dependant.
265  * On machines using EBCDIC we have to sort it.
266  */
267     static void
268 sortFunctions(void)
269 {
270     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
271 
272     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
273 }
274 #endif
275 
276 
277 /*
278  * Initialize the global and v: variables.
279  */
280     void
281 eval_init(void)
282 {
283     int		    i;
284     struct vimvar   *p;
285 
286     init_var_dict(&globvardict, &globvars_var, VAR_DEF_SCOPE);
287     init_var_dict(&vimvardict, &vimvars_var, VAR_SCOPE);
288     vimvardict.dv_lock = VAR_FIXED;
289     hash_init(&compat_hashtab);
290     func_init();
291 
292     for (i = 0; i < VV_LEN; ++i)
293     {
294 	p = &vimvars[i];
295 	if (STRLEN(p->vv_name) > 16)
296 	{
297 	    IEMSG("INTERNAL: name too long, increase size of dictitem16_T");
298 	    getout(1);
299 	}
300 	STRCPY(p->vv_di.di_key, p->vv_name);
301 	if (p->vv_flags & VV_RO)
302 	    p->vv_di.di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
303 	else if (p->vv_flags & VV_RO_SBX)
304 	    p->vv_di.di_flags = DI_FLAGS_RO_SBX | DI_FLAGS_FIX;
305 	else
306 	    p->vv_di.di_flags = DI_FLAGS_FIX;
307 
308 	/* add to v: scope dict, unless the value is not always available */
309 	if (p->vv_type != VAR_UNKNOWN)
310 	    hash_add(&vimvarht, p->vv_di.di_key);
311 	if (p->vv_flags & VV_COMPAT)
312 	    /* add to compat scope dict */
313 	    hash_add(&compat_hashtab, p->vv_di.di_key);
314     }
315     vimvars[VV_VERSION].vv_nr = VIM_VERSION_100;
316 
317     set_vim_var_nr(VV_SEARCHFORWARD, 1L);
318     set_vim_var_nr(VV_HLSEARCH, 1L);
319     set_vim_var_dict(VV_COMPLETED_ITEM, dict_alloc());
320     set_vim_var_list(VV_ERRORS, list_alloc());
321 
322     set_vim_var_nr(VV_FALSE, VVAL_FALSE);
323     set_vim_var_nr(VV_TRUE, VVAL_TRUE);
324     set_vim_var_nr(VV_NONE, VVAL_NONE);
325     set_vim_var_nr(VV_NULL, VVAL_NULL);
326 
327     set_vim_var_nr(VV_TYPE_NUMBER,  VAR_TYPE_NUMBER);
328     set_vim_var_nr(VV_TYPE_STRING,  VAR_TYPE_STRING);
329     set_vim_var_nr(VV_TYPE_FUNC,    VAR_TYPE_FUNC);
330     set_vim_var_nr(VV_TYPE_LIST,    VAR_TYPE_LIST);
331     set_vim_var_nr(VV_TYPE_DICT,    VAR_TYPE_DICT);
332     set_vim_var_nr(VV_TYPE_FLOAT,   VAR_TYPE_FLOAT);
333     set_vim_var_nr(VV_TYPE_BOOL,    VAR_TYPE_BOOL);
334     set_vim_var_nr(VV_TYPE_NONE,    VAR_TYPE_NONE);
335     set_vim_var_nr(VV_TYPE_JOB,     VAR_TYPE_JOB);
336     set_vim_var_nr(VV_TYPE_CHANNEL, VAR_TYPE_CHANNEL);
337 
338     set_reg_var(0);  /* default for v:register is not 0 but '"' */
339 
340 #ifdef EBCDIC
341     /*
342      * Sort the function table, to enable binary search.
343      */
344     sortFunctions();
345 #endif
346 }
347 
348 #if defined(EXITFREE) || defined(PROTO)
349     void
350 eval_clear(void)
351 {
352     int		    i;
353     struct vimvar   *p;
354 
355     for (i = 0; i < VV_LEN; ++i)
356     {
357 	p = &vimvars[i];
358 	if (p->vv_di.di_tv.v_type == VAR_STRING)
359 	{
360 	    vim_free(p->vv_str);
361 	    p->vv_str = NULL;
362 	}
363 	else if (p->vv_di.di_tv.v_type == VAR_LIST)
364 	{
365 	    list_unref(p->vv_list);
366 	    p->vv_list = NULL;
367 	}
368     }
369     hash_clear(&vimvarht);
370     hash_init(&vimvarht);  /* garbage_collect() will access it */
371     hash_clear(&compat_hashtab);
372 
373     free_scriptnames();
374 # if defined(FEAT_CMDL_COMPL)
375     free_locales();
376 # endif
377 
378     /* global variables */
379     vars_clear(&globvarht);
380 
381     /* autoloaded script names */
382     ga_clear_strings(&ga_loaded);
383 
384     /* Script-local variables. First clear all the variables and in a second
385      * loop free the scriptvar_T, because a variable in one script might hold
386      * a reference to the whole scope of another script. */
387     for (i = 1; i <= ga_scripts.ga_len; ++i)
388 	vars_clear(&SCRIPT_VARS(i));
389     for (i = 1; i <= ga_scripts.ga_len; ++i)
390 	vim_free(SCRIPT_SV(i));
391     ga_clear(&ga_scripts);
392 
393     /* unreferenced lists and dicts */
394     (void)garbage_collect(FALSE);
395 
396     /* functions */
397     free_all_functions();
398 }
399 #endif
400 
401 
402 /*
403  * Set an internal variable to a string value. Creates the variable if it does
404  * not already exist.
405  */
406     void
407 set_internal_string_var(char_u *name, char_u *value)
408 {
409     char_u	*val;
410     typval_T	*tvp;
411 
412     val = vim_strsave(value);
413     if (val != NULL)
414     {
415 	tvp = alloc_string_tv(val);
416 	if (tvp != NULL)
417 	{
418 	    set_var(name, tvp, FALSE);
419 	    free_tv(tvp);
420 	}
421     }
422 }
423 
424 static lval_T	*redir_lval = NULL;
425 #define EVALCMD_BUSY (redir_lval == (lval_T *)&redir_lval)
426 static garray_T redir_ga;	/* only valid when redir_lval is not NULL */
427 static char_u	*redir_endp = NULL;
428 static char_u	*redir_varname = NULL;
429 
430 /*
431  * Start recording command output to a variable
432  * When "append" is TRUE append to an existing variable.
433  * Returns OK if successfully completed the setup.  FAIL otherwise.
434  */
435     int
436 var_redir_start(char_u *name, int append)
437 {
438     int		save_emsg;
439     int		err;
440     typval_T	tv;
441 
442     /* Catch a bad name early. */
443     if (!eval_isnamec1(*name))
444     {
445 	EMSG(_(e_invarg));
446 	return FAIL;
447     }
448 
449     /* Make a copy of the name, it is used in redir_lval until redir ends. */
450     redir_varname = vim_strsave(name);
451     if (redir_varname == NULL)
452 	return FAIL;
453 
454     redir_lval = (lval_T *)alloc_clear((unsigned)sizeof(lval_T));
455     if (redir_lval == NULL)
456     {
457 	var_redir_stop();
458 	return FAIL;
459     }
460 
461     /* The output is stored in growarray "redir_ga" until redirection ends. */
462     ga_init2(&redir_ga, (int)sizeof(char), 500);
463 
464     /* Parse the variable name (can be a dict or list entry). */
465     redir_endp = get_lval(redir_varname, NULL, redir_lval, FALSE, FALSE, 0,
466 							     FNE_CHECK_START);
467     if (redir_endp == NULL || redir_lval->ll_name == NULL || *redir_endp != NUL)
468     {
469 	clear_lval(redir_lval);
470 	if (redir_endp != NULL && *redir_endp != NUL)
471 	    /* Trailing characters are present after the variable name */
472 	    EMSG(_(e_trailing));
473 	else
474 	    EMSG(_(e_invarg));
475 	redir_endp = NULL;  /* don't store a value, only cleanup */
476 	var_redir_stop();
477 	return FAIL;
478     }
479 
480     /* check if we can write to the variable: set it to or append an empty
481      * string */
482     save_emsg = did_emsg;
483     did_emsg = FALSE;
484     tv.v_type = VAR_STRING;
485     tv.vval.v_string = (char_u *)"";
486     if (append)
487 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, (char_u *)".");
488     else
489 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, (char_u *)"=");
490     clear_lval(redir_lval);
491     err = did_emsg;
492     did_emsg |= save_emsg;
493     if (err)
494     {
495 	redir_endp = NULL;  /* don't store a value, only cleanup */
496 	var_redir_stop();
497 	return FAIL;
498     }
499 
500     return OK;
501 }
502 
503 /*
504  * Append "value[value_len]" to the variable set by var_redir_start().
505  * The actual appending is postponed until redirection ends, because the value
506  * appended may in fact be the string we write to, changing it may cause freed
507  * memory to be used:
508  *   :redir => foo
509  *   :let foo
510  *   :redir END
511  */
512     void
513 var_redir_str(char_u *value, int value_len)
514 {
515     int		len;
516 
517     if (redir_lval == NULL)
518 	return;
519 
520     if (value_len == -1)
521 	len = (int)STRLEN(value);	/* Append the entire string */
522     else
523 	len = value_len;		/* Append only "value_len" characters */
524 
525     if (ga_grow(&redir_ga, len) == OK)
526     {
527 	mch_memmove((char *)redir_ga.ga_data + redir_ga.ga_len, value, len);
528 	redir_ga.ga_len += len;
529     }
530     else
531 	var_redir_stop();
532 }
533 
534 /*
535  * Stop redirecting command output to a variable.
536  * Frees the allocated memory.
537  */
538     void
539 var_redir_stop(void)
540 {
541     typval_T	tv;
542 
543     if (EVALCMD_BUSY)
544     {
545 	redir_lval = NULL;
546 	return;
547     }
548 
549     if (redir_lval != NULL)
550     {
551 	/* If there was no error: assign the text to the variable. */
552 	if (redir_endp != NULL)
553 	{
554 	    ga_append(&redir_ga, NUL);  /* Append the trailing NUL. */
555 	    tv.v_type = VAR_STRING;
556 	    tv.vval.v_string = redir_ga.ga_data;
557 	    /* Call get_lval() again, if it's inside a Dict or List it may
558 	     * have changed. */
559 	    redir_endp = get_lval(redir_varname, NULL, redir_lval,
560 					FALSE, FALSE, 0, FNE_CHECK_START);
561 	    if (redir_endp != NULL && redir_lval->ll_name != NULL)
562 		set_var_lval(redir_lval, redir_endp, &tv, FALSE, (char_u *)".");
563 	    clear_lval(redir_lval);
564 	}
565 
566 	/* free the collected output */
567 	vim_free(redir_ga.ga_data);
568 	redir_ga.ga_data = NULL;
569 
570 	vim_free(redir_lval);
571 	redir_lval = NULL;
572     }
573     vim_free(redir_varname);
574     redir_varname = NULL;
575 }
576 
577 # if defined(FEAT_MBYTE) || defined(PROTO)
578     int
579 eval_charconvert(
580     char_u	*enc_from,
581     char_u	*enc_to,
582     char_u	*fname_from,
583     char_u	*fname_to)
584 {
585     int		err = FALSE;
586 
587     set_vim_var_string(VV_CC_FROM, enc_from, -1);
588     set_vim_var_string(VV_CC_TO, enc_to, -1);
589     set_vim_var_string(VV_FNAME_IN, fname_from, -1);
590     set_vim_var_string(VV_FNAME_OUT, fname_to, -1);
591     if (eval_to_bool(p_ccv, &err, NULL, FALSE))
592 	err = TRUE;
593     set_vim_var_string(VV_CC_FROM, NULL, -1);
594     set_vim_var_string(VV_CC_TO, NULL, -1);
595     set_vim_var_string(VV_FNAME_IN, NULL, -1);
596     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
597 
598     if (err)
599 	return FAIL;
600     return OK;
601 }
602 # endif
603 
604 # if defined(FEAT_POSTSCRIPT) || defined(PROTO)
605     int
606 eval_printexpr(char_u *fname, char_u *args)
607 {
608     int		err = FALSE;
609 
610     set_vim_var_string(VV_FNAME_IN, fname, -1);
611     set_vim_var_string(VV_CMDARG, args, -1);
612     if (eval_to_bool(p_pexpr, &err, NULL, FALSE))
613 	err = TRUE;
614     set_vim_var_string(VV_FNAME_IN, NULL, -1);
615     set_vim_var_string(VV_CMDARG, NULL, -1);
616 
617     if (err)
618     {
619 	mch_remove(fname);
620 	return FAIL;
621     }
622     return OK;
623 }
624 # endif
625 
626 # if defined(FEAT_DIFF) || defined(PROTO)
627     void
628 eval_diff(
629     char_u	*origfile,
630     char_u	*newfile,
631     char_u	*outfile)
632 {
633     int		err = FALSE;
634 
635     set_vim_var_string(VV_FNAME_IN, origfile, -1);
636     set_vim_var_string(VV_FNAME_NEW, newfile, -1);
637     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
638     (void)eval_to_bool(p_dex, &err, NULL, FALSE);
639     set_vim_var_string(VV_FNAME_IN, NULL, -1);
640     set_vim_var_string(VV_FNAME_NEW, NULL, -1);
641     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
642 }
643 
644     void
645 eval_patch(
646     char_u	*origfile,
647     char_u	*difffile,
648     char_u	*outfile)
649 {
650     int		err;
651 
652     set_vim_var_string(VV_FNAME_IN, origfile, -1);
653     set_vim_var_string(VV_FNAME_DIFF, difffile, -1);
654     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
655     (void)eval_to_bool(p_pex, &err, NULL, FALSE);
656     set_vim_var_string(VV_FNAME_IN, NULL, -1);
657     set_vim_var_string(VV_FNAME_DIFF, NULL, -1);
658     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
659 }
660 # endif
661 
662 /*
663  * Top level evaluation function, returning a boolean.
664  * Sets "error" to TRUE if there was an error.
665  * Return TRUE or FALSE.
666  */
667     int
668 eval_to_bool(
669     char_u	*arg,
670     int		*error,
671     char_u	**nextcmd,
672     int		skip)	    /* only parse, don't execute */
673 {
674     typval_T	tv;
675     varnumber_T	retval = FALSE;
676 
677     if (skip)
678 	++emsg_skip;
679     if (eval0(arg, &tv, nextcmd, !skip) == FAIL)
680 	*error = TRUE;
681     else
682     {
683 	*error = FALSE;
684 	if (!skip)
685 	{
686 	    retval = (get_tv_number_chk(&tv, error) != 0);
687 	    clear_tv(&tv);
688 	}
689     }
690     if (skip)
691 	--emsg_skip;
692 
693     return (int)retval;
694 }
695 
696 /*
697  * Top level evaluation function, returning a string.  If "skip" is TRUE,
698  * only parsing to "nextcmd" is done, without reporting errors.  Return
699  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
700  */
701     char_u *
702 eval_to_string_skip(
703     char_u	*arg,
704     char_u	**nextcmd,
705     int		skip)	    /* only parse, don't execute */
706 {
707     typval_T	tv;
708     char_u	*retval;
709 
710     if (skip)
711 	++emsg_skip;
712     if (eval0(arg, &tv, nextcmd, !skip) == FAIL || skip)
713 	retval = NULL;
714     else
715     {
716 	retval = vim_strsave(get_tv_string(&tv));
717 	clear_tv(&tv);
718     }
719     if (skip)
720 	--emsg_skip;
721 
722     return retval;
723 }
724 
725 /*
726  * Skip over an expression at "*pp".
727  * Return FAIL for an error, OK otherwise.
728  */
729     int
730 skip_expr(char_u **pp)
731 {
732     typval_T	rettv;
733 
734     *pp = skipwhite(*pp);
735     return eval1(pp, &rettv, FALSE);
736 }
737 
738 /*
739  * Top level evaluation function, returning a string.
740  * When "convert" is TRUE convert a List into a sequence of lines and convert
741  * a Float to a String.
742  * Return pointer to allocated memory, or NULL for failure.
743  */
744     char_u *
745 eval_to_string(
746     char_u	*arg,
747     char_u	**nextcmd,
748     int		convert)
749 {
750     typval_T	tv;
751     char_u	*retval;
752     garray_T	ga;
753 #ifdef FEAT_FLOAT
754     char_u	numbuf[NUMBUFLEN];
755 #endif
756 
757     if (eval0(arg, &tv, nextcmd, TRUE) == FAIL)
758 	retval = NULL;
759     else
760     {
761 	if (convert && tv.v_type == VAR_LIST)
762 	{
763 	    ga_init2(&ga, (int)sizeof(char), 80);
764 	    if (tv.vval.v_list != NULL)
765 	    {
766 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
767 		if (tv.vval.v_list->lv_len > 0)
768 		    ga_append(&ga, NL);
769 	    }
770 	    ga_append(&ga, NUL);
771 	    retval = (char_u *)ga.ga_data;
772 	}
773 #ifdef FEAT_FLOAT
774 	else if (convert && tv.v_type == VAR_FLOAT)
775 	{
776 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
777 	    retval = vim_strsave(numbuf);
778 	}
779 #endif
780 	else
781 	    retval = vim_strsave(get_tv_string(&tv));
782 	clear_tv(&tv);
783     }
784 
785     return retval;
786 }
787 
788 /*
789  * Call eval_to_string() without using current local variables and using
790  * textlock.  When "use_sandbox" is TRUE use the sandbox.
791  */
792     char_u *
793 eval_to_string_safe(
794     char_u	*arg,
795     char_u	**nextcmd,
796     int		use_sandbox)
797 {
798     char_u	*retval;
799     void	*save_funccalp;
800 
801     save_funccalp = save_funccal();
802     if (use_sandbox)
803 	++sandbox;
804     ++textlock;
805     retval = eval_to_string(arg, nextcmd, FALSE);
806     if (use_sandbox)
807 	--sandbox;
808     --textlock;
809     restore_funccal(save_funccalp);
810     return retval;
811 }
812 
813 /*
814  * Top level evaluation function, returning a number.
815  * Evaluates "expr" silently.
816  * Returns -1 for an error.
817  */
818     varnumber_T
819 eval_to_number(char_u *expr)
820 {
821     typval_T	rettv;
822     varnumber_T	retval;
823     char_u	*p = skipwhite(expr);
824 
825     ++emsg_off;
826 
827     if (eval1(&p, &rettv, TRUE) == FAIL)
828 	retval = -1;
829     else
830     {
831 	retval = get_tv_number_chk(&rettv, NULL);
832 	clear_tv(&rettv);
833     }
834     --emsg_off;
835 
836     return retval;
837 }
838 
839 /*
840  * Prepare v: variable "idx" to be used.
841  * Save the current typeval in "save_tv".
842  * When not used yet add the variable to the v: hashtable.
843  */
844     static void
845 prepare_vimvar(int idx, typval_T *save_tv)
846 {
847     *save_tv = vimvars[idx].vv_tv;
848     if (vimvars[idx].vv_type == VAR_UNKNOWN)
849 	hash_add(&vimvarht, vimvars[idx].vv_di.di_key);
850 }
851 
852 /*
853  * Restore v: variable "idx" to typeval "save_tv".
854  * When no longer defined, remove the variable from the v: hashtable.
855  */
856     static void
857 restore_vimvar(int idx, typval_T *save_tv)
858 {
859     hashitem_T	*hi;
860 
861     vimvars[idx].vv_tv = *save_tv;
862     if (vimvars[idx].vv_type == VAR_UNKNOWN)
863     {
864 	hi = hash_find(&vimvarht, vimvars[idx].vv_di.di_key);
865 	if (HASHITEM_EMPTY(hi))
866 	    internal_error("restore_vimvar()");
867 	else
868 	    hash_remove(&vimvarht, hi);
869     }
870 }
871 
872 #if defined(FEAT_SPELL) || defined(PROTO)
873 /*
874  * Evaluate an expression to a list with suggestions.
875  * For the "expr:" part of 'spellsuggest'.
876  * Returns NULL when there is an error.
877  */
878     list_T *
879 eval_spell_expr(char_u *badword, char_u *expr)
880 {
881     typval_T	save_val;
882     typval_T	rettv;
883     list_T	*list = NULL;
884     char_u	*p = skipwhite(expr);
885 
886     /* Set "v:val" to the bad word. */
887     prepare_vimvar(VV_VAL, &save_val);
888     vimvars[VV_VAL].vv_type = VAR_STRING;
889     vimvars[VV_VAL].vv_str = badword;
890     if (p_verbose == 0)
891 	++emsg_off;
892 
893     if (eval1(&p, &rettv, TRUE) == OK)
894     {
895 	if (rettv.v_type != VAR_LIST)
896 	    clear_tv(&rettv);
897 	else
898 	    list = rettv.vval.v_list;
899     }
900 
901     if (p_verbose == 0)
902 	--emsg_off;
903     restore_vimvar(VV_VAL, &save_val);
904 
905     return list;
906 }
907 
908 /*
909  * "list" is supposed to contain two items: a word and a number.  Return the
910  * word in "pp" and the number as the return value.
911  * Return -1 if anything isn't right.
912  * Used to get the good word and score from the eval_spell_expr() result.
913  */
914     int
915 get_spellword(list_T *list, char_u **pp)
916 {
917     listitem_T	*li;
918 
919     li = list->lv_first;
920     if (li == NULL)
921 	return -1;
922     *pp = get_tv_string(&li->li_tv);
923 
924     li = li->li_next;
925     if (li == NULL)
926 	return -1;
927     return (int)get_tv_number(&li->li_tv);
928 }
929 #endif
930 
931 /*
932  * Top level evaluation function.
933  * Returns an allocated typval_T with the result.
934  * Returns NULL when there is an error.
935  */
936     typval_T *
937 eval_expr(char_u *arg, char_u **nextcmd)
938 {
939     typval_T	*tv;
940 
941     tv = (typval_T *)alloc(sizeof(typval_T));
942     if (tv != NULL && eval0(arg, tv, nextcmd, TRUE) == FAIL)
943     {
944 	vim_free(tv);
945 	tv = NULL;
946     }
947 
948     return tv;
949 }
950 
951 
952 /*
953  * Call some Vim script function and return the result in "*rettv".
954  * Uses argv[argc] for the function arguments.  Only Number and String
955  * arguments are currently supported.
956  * Returns OK or FAIL.
957  */
958     int
959 call_vim_function(
960     char_u      *func,
961     int		argc,
962     char_u      **argv,
963     int		safe,		/* use the sandbox */
964     int		str_arg_only,	/* all arguments are strings */
965     typval_T	*rettv)
966 {
967     typval_T	*argvars;
968     varnumber_T	n;
969     int		len;
970     int		i;
971     int		doesrange;
972     void	*save_funccalp = NULL;
973     int		ret;
974 
975     argvars = (typval_T *)alloc((unsigned)((argc + 1) * sizeof(typval_T)));
976     if (argvars == NULL)
977 	return FAIL;
978 
979     for (i = 0; i < argc; i++)
980     {
981 	/* Pass a NULL or empty argument as an empty string */
982 	if (argv[i] == NULL || *argv[i] == NUL)
983 	{
984 	    argvars[i].v_type = VAR_STRING;
985 	    argvars[i].vval.v_string = (char_u *)"";
986 	    continue;
987 	}
988 
989 	if (str_arg_only)
990 	    len = 0;
991 	else
992 	    /* Recognize a number argument, the others must be strings. */
993 	    vim_str2nr(argv[i], NULL, &len, STR2NR_ALL, &n, NULL, 0);
994 	if (len != 0 && len == (int)STRLEN(argv[i]))
995 	{
996 	    argvars[i].v_type = VAR_NUMBER;
997 	    argvars[i].vval.v_number = n;
998 	}
999 	else
1000 	{
1001 	    argvars[i].v_type = VAR_STRING;
1002 	    argvars[i].vval.v_string = argv[i];
1003 	}
1004     }
1005 
1006     if (safe)
1007     {
1008 	save_funccalp = save_funccal();
1009 	++sandbox;
1010     }
1011 
1012     rettv->v_type = VAR_UNKNOWN;		/* clear_tv() uses this */
1013     ret = call_func(func, (int)STRLEN(func), rettv, argc, argvars, NULL,
1014 		    curwin->w_cursor.lnum, curwin->w_cursor.lnum,
1015 		    &doesrange, TRUE, NULL, NULL);
1016     if (safe)
1017     {
1018 	--sandbox;
1019 	restore_funccal(save_funccalp);
1020     }
1021     vim_free(argvars);
1022 
1023     if (ret == FAIL)
1024 	clear_tv(rettv);
1025 
1026     return ret;
1027 }
1028 
1029 /*
1030  * Call Vim script function "func" and return the result as a number.
1031  * Returns -1 when calling the function fails.
1032  * Uses argv[argc] for the function arguments.
1033  */
1034     varnumber_T
1035 call_func_retnr(
1036     char_u      *func,
1037     int		argc,
1038     char_u      **argv,
1039     int		safe)		/* use the sandbox */
1040 {
1041     typval_T	rettv;
1042     varnumber_T	retval;
1043 
1044     /* All arguments are passed as strings, no conversion to number. */
1045     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
1046 	return -1;
1047 
1048     retval = get_tv_number_chk(&rettv, NULL);
1049     clear_tv(&rettv);
1050     return retval;
1051 }
1052 
1053 #if (defined(FEAT_USR_CMDS) && defined(FEAT_CMDL_COMPL)) \
1054 	|| defined(FEAT_COMPL_FUNC) || defined(PROTO)
1055 
1056 # if (defined(FEAT_USR_CMDS) && defined(FEAT_CMDL_COMPL)) || defined(PROTO)
1057 /*
1058  * Call Vim script function "func" and return the result as a string.
1059  * Returns NULL when calling the function fails.
1060  * Uses argv[argc] for the function arguments.
1061  */
1062     void *
1063 call_func_retstr(
1064     char_u      *func,
1065     int		argc,
1066     char_u      **argv,
1067     int		safe)		/* use the sandbox */
1068 {
1069     typval_T	rettv;
1070     char_u	*retval;
1071 
1072     /* All arguments are passed as strings, no conversion to number. */
1073     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
1074 	return NULL;
1075 
1076     retval = vim_strsave(get_tv_string(&rettv));
1077     clear_tv(&rettv);
1078     return retval;
1079 }
1080 # endif
1081 
1082 /*
1083  * Call Vim script function "func" and return the result as a List.
1084  * Uses argv[argc] for the function arguments.
1085  * Returns NULL when there is something wrong.
1086  */
1087     void *
1088 call_func_retlist(
1089     char_u      *func,
1090     int		argc,
1091     char_u      **argv,
1092     int		safe)		/* use the sandbox */
1093 {
1094     typval_T	rettv;
1095 
1096     /* All arguments are passed as strings, no conversion to number. */
1097     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
1098 	return NULL;
1099 
1100     if (rettv.v_type != VAR_LIST)
1101     {
1102 	clear_tv(&rettv);
1103 	return NULL;
1104     }
1105 
1106     return rettv.vval.v_list;
1107 }
1108 #endif
1109 
1110 
1111 #ifdef FEAT_FOLDING
1112 /*
1113  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
1114  * it in "*cp".  Doesn't give error messages.
1115  */
1116     int
1117 eval_foldexpr(char_u *arg, int *cp)
1118 {
1119     typval_T	tv;
1120     varnumber_T	retval;
1121     char_u	*s;
1122     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
1123 								   OPT_LOCAL);
1124 
1125     ++emsg_off;
1126     if (use_sandbox)
1127 	++sandbox;
1128     ++textlock;
1129     *cp = NUL;
1130     if (eval0(arg, &tv, NULL, TRUE) == FAIL)
1131 	retval = 0;
1132     else
1133     {
1134 	/* If the result is a number, just return the number. */
1135 	if (tv.v_type == VAR_NUMBER)
1136 	    retval = tv.vval.v_number;
1137 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
1138 	    retval = 0;
1139 	else
1140 	{
1141 	    /* If the result is a string, check if there is a non-digit before
1142 	     * the number. */
1143 	    s = tv.vval.v_string;
1144 	    if (!VIM_ISDIGIT(*s) && *s != '-')
1145 		*cp = *s++;
1146 	    retval = atol((char *)s);
1147 	}
1148 	clear_tv(&tv);
1149     }
1150     --emsg_off;
1151     if (use_sandbox)
1152 	--sandbox;
1153     --textlock;
1154 
1155     return (int)retval;
1156 }
1157 #endif
1158 
1159 /*
1160  * ":let"			list all variable values
1161  * ":let var1 var2"		list variable values
1162  * ":let var = expr"		assignment command.
1163  * ":let var += expr"		assignment command.
1164  * ":let var -= expr"		assignment command.
1165  * ":let var .= expr"		assignment command.
1166  * ":let [var1, var2] = expr"	unpack list.
1167  */
1168     void
1169 ex_let(exarg_T *eap)
1170 {
1171     char_u	*arg = eap->arg;
1172     char_u	*expr = NULL;
1173     typval_T	rettv;
1174     int		i;
1175     int		var_count = 0;
1176     int		semicolon = 0;
1177     char_u	op[2];
1178     char_u	*argend;
1179     int		first = TRUE;
1180 
1181     argend = skip_var_list(arg, &var_count, &semicolon);
1182     if (argend == NULL)
1183 	return;
1184     if (argend > arg && argend[-1] == '.')  /* for var.='str' */
1185 	--argend;
1186     expr = skipwhite(argend);
1187     if (*expr != '=' && !(vim_strchr((char_u *)"+-.", *expr) != NULL
1188 			  && expr[1] == '='))
1189     {
1190 	/*
1191 	 * ":let" without "=": list variables
1192 	 */
1193 	if (*arg == '[')
1194 	    EMSG(_(e_invarg));
1195 	else if (!ends_excmd(*arg))
1196 	    /* ":let var1 var2" */
1197 	    arg = list_arg_vars(eap, arg, &first);
1198 	else if (!eap->skip)
1199 	{
1200 	    /* ":let" */
1201 	    list_glob_vars(&first);
1202 	    list_buf_vars(&first);
1203 	    list_win_vars(&first);
1204 #ifdef FEAT_WINDOWS
1205 	    list_tab_vars(&first);
1206 #endif
1207 	    list_script_vars(&first);
1208 	    list_func_vars(&first);
1209 	    list_vim_vars(&first);
1210 	}
1211 	eap->nextcmd = check_nextcmd(arg);
1212     }
1213     else
1214     {
1215 	op[0] = '=';
1216 	op[1] = NUL;
1217 	if (*expr != '=')
1218 	{
1219 	    if (vim_strchr((char_u *)"+-.", *expr) != NULL)
1220 		op[0] = *expr;   /* +=, -= or .= */
1221 	    expr = skipwhite(expr + 2);
1222 	}
1223 	else
1224 	    expr = skipwhite(expr + 1);
1225 
1226 	if (eap->skip)
1227 	    ++emsg_skip;
1228 	i = eval0(expr, &rettv, &eap->nextcmd, !eap->skip);
1229 	if (eap->skip)
1230 	{
1231 	    if (i != FAIL)
1232 		clear_tv(&rettv);
1233 	    --emsg_skip;
1234 	}
1235 	else if (i != FAIL)
1236 	{
1237 	    (void)ex_let_vars(eap->arg, &rettv, FALSE, semicolon, var_count,
1238 									  op);
1239 	    clear_tv(&rettv);
1240 	}
1241     }
1242 }
1243 
1244 /*
1245  * Assign the typevalue "tv" to the variable or variables at "arg_start".
1246  * Handles both "var" with any type and "[var, var; var]" with a list type.
1247  * When "nextchars" is not NULL it points to a string with characters that
1248  * must appear after the variable(s).  Use "+", "-" or "." for add, subtract
1249  * or concatenate.
1250  * Returns OK or FAIL;
1251  */
1252     static int
1253 ex_let_vars(
1254     char_u	*arg_start,
1255     typval_T	*tv,
1256     int		copy,		/* copy values from "tv", don't move */
1257     int		semicolon,	/* from skip_var_list() */
1258     int		var_count,	/* from skip_var_list() */
1259     char_u	*nextchars)
1260 {
1261     char_u	*arg = arg_start;
1262     list_T	*l;
1263     int		i;
1264     listitem_T	*item;
1265     typval_T	ltv;
1266 
1267     if (*arg != '[')
1268     {
1269 	/*
1270 	 * ":let var = expr" or ":for var in list"
1271 	 */
1272 	if (ex_let_one(arg, tv, copy, nextchars, nextchars) == NULL)
1273 	    return FAIL;
1274 	return OK;
1275     }
1276 
1277     /*
1278      * ":let [v1, v2] = list" or ":for [v1, v2] in listlist"
1279      */
1280     if (tv->v_type != VAR_LIST || (l = tv->vval.v_list) == NULL)
1281     {
1282 	EMSG(_(e_listreq));
1283 	return FAIL;
1284     }
1285 
1286     i = list_len(l);
1287     if (semicolon == 0 && var_count < i)
1288     {
1289 	EMSG(_("E687: Less targets than List items"));
1290 	return FAIL;
1291     }
1292     if (var_count - semicolon > i)
1293     {
1294 	EMSG(_("E688: More targets than List items"));
1295 	return FAIL;
1296     }
1297 
1298     item = l->lv_first;
1299     while (*arg != ']')
1300     {
1301 	arg = skipwhite(arg + 1);
1302 	arg = ex_let_one(arg, &item->li_tv, TRUE, (char_u *)",;]", nextchars);
1303 	item = item->li_next;
1304 	if (arg == NULL)
1305 	    return FAIL;
1306 
1307 	arg = skipwhite(arg);
1308 	if (*arg == ';')
1309 	{
1310 	    /* Put the rest of the list (may be empty) in the var after ';'.
1311 	     * Create a new list for this. */
1312 	    l = list_alloc();
1313 	    if (l == NULL)
1314 		return FAIL;
1315 	    while (item != NULL)
1316 	    {
1317 		list_append_tv(l, &item->li_tv);
1318 		item = item->li_next;
1319 	    }
1320 
1321 	    ltv.v_type = VAR_LIST;
1322 	    ltv.v_lock = 0;
1323 	    ltv.vval.v_list = l;
1324 	    l->lv_refcount = 1;
1325 
1326 	    arg = ex_let_one(skipwhite(arg + 1), &ltv, FALSE,
1327 						    (char_u *)"]", nextchars);
1328 	    clear_tv(&ltv);
1329 	    if (arg == NULL)
1330 		return FAIL;
1331 	    break;
1332 	}
1333 	else if (*arg != ',' && *arg != ']')
1334 	{
1335 	    internal_error("ex_let_vars()");
1336 	    return FAIL;
1337 	}
1338     }
1339 
1340     return OK;
1341 }
1342 
1343 /*
1344  * Skip over assignable variable "var" or list of variables "[var, var]".
1345  * Used for ":let varvar = expr" and ":for varvar in expr".
1346  * For "[var, var]" increment "*var_count" for each variable.
1347  * for "[var, var; var]" set "semicolon".
1348  * Return NULL for an error.
1349  */
1350     static char_u *
1351 skip_var_list(
1352     char_u	*arg,
1353     int		*var_count,
1354     int		*semicolon)
1355 {
1356     char_u	*p, *s;
1357 
1358     if (*arg == '[')
1359     {
1360 	/* "[var, var]": find the matching ']'. */
1361 	p = arg;
1362 	for (;;)
1363 	{
1364 	    p = skipwhite(p + 1);	/* skip whites after '[', ';' or ',' */
1365 	    s = skip_var_one(p);
1366 	    if (s == p)
1367 	    {
1368 		EMSG2(_(e_invarg2), p);
1369 		return NULL;
1370 	    }
1371 	    ++*var_count;
1372 
1373 	    p = skipwhite(s);
1374 	    if (*p == ']')
1375 		break;
1376 	    else if (*p == ';')
1377 	    {
1378 		if (*semicolon == 1)
1379 		{
1380 		    EMSG(_("Double ; in list of variables"));
1381 		    return NULL;
1382 		}
1383 		*semicolon = 1;
1384 	    }
1385 	    else if (*p != ',')
1386 	    {
1387 		EMSG2(_(e_invarg2), p);
1388 		return NULL;
1389 	    }
1390 	}
1391 	return p + 1;
1392     }
1393     else
1394 	return skip_var_one(arg);
1395 }
1396 
1397 /*
1398  * Skip one (assignable) variable name, including @r, $VAR, &option, d.key,
1399  * l[idx].
1400  */
1401     static char_u *
1402 skip_var_one(char_u *arg)
1403 {
1404     if (*arg == '@' && arg[1] != NUL)
1405 	return arg + 2;
1406     return find_name_end(*arg == '$' || *arg == '&' ? arg + 1 : arg,
1407 				   NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1408 }
1409 
1410 /*
1411  * List variables for hashtab "ht" with prefix "prefix".
1412  * If "empty" is TRUE also list NULL strings as empty strings.
1413  */
1414     void
1415 list_hashtable_vars(
1416     hashtab_T	*ht,
1417     char_u	*prefix,
1418     int		empty,
1419     int		*first)
1420 {
1421     hashitem_T	*hi;
1422     dictitem_T	*di;
1423     int		todo;
1424 
1425     todo = (int)ht->ht_used;
1426     for (hi = ht->ht_array; todo > 0 && !got_int; ++hi)
1427     {
1428 	if (!HASHITEM_EMPTY(hi))
1429 	{
1430 	    --todo;
1431 	    di = HI2DI(hi);
1432 	    if (empty || di->di_tv.v_type != VAR_STRING
1433 					   || di->di_tv.vval.v_string != NULL)
1434 		list_one_var(di, prefix, first);
1435 	}
1436     }
1437 }
1438 
1439 /*
1440  * List global variables.
1441  */
1442     static void
1443 list_glob_vars(int *first)
1444 {
1445     list_hashtable_vars(&globvarht, (char_u *)"", TRUE, first);
1446 }
1447 
1448 /*
1449  * List buffer variables.
1450  */
1451     static void
1452 list_buf_vars(int *first)
1453 {
1454     list_hashtable_vars(&curbuf->b_vars->dv_hashtab, (char_u *)"b:",
1455 								 TRUE, first);
1456 }
1457 
1458 /*
1459  * List window variables.
1460  */
1461     static void
1462 list_win_vars(int *first)
1463 {
1464     list_hashtable_vars(&curwin->w_vars->dv_hashtab,
1465 						 (char_u *)"w:", TRUE, first);
1466 }
1467 
1468 #ifdef FEAT_WINDOWS
1469 /*
1470  * List tab page variables.
1471  */
1472     static void
1473 list_tab_vars(int *first)
1474 {
1475     list_hashtable_vars(&curtab->tp_vars->dv_hashtab,
1476 						 (char_u *)"t:", TRUE, first);
1477 }
1478 #endif
1479 
1480 /*
1481  * List Vim variables.
1482  */
1483     static void
1484 list_vim_vars(int *first)
1485 {
1486     list_hashtable_vars(&vimvarht, (char_u *)"v:", FALSE, first);
1487 }
1488 
1489 /*
1490  * List script-local variables, if there is a script.
1491  */
1492     static void
1493 list_script_vars(int *first)
1494 {
1495     if (current_SID > 0 && current_SID <= ga_scripts.ga_len)
1496 	list_hashtable_vars(&SCRIPT_VARS(current_SID),
1497 						(char_u *)"s:", FALSE, first);
1498 }
1499 
1500 /*
1501  * List variables in "arg".
1502  */
1503     static char_u *
1504 list_arg_vars(exarg_T *eap, char_u *arg, int *first)
1505 {
1506     int		error = FALSE;
1507     int		len;
1508     char_u	*name;
1509     char_u	*name_start;
1510     char_u	*arg_subsc;
1511     char_u	*tofree;
1512     typval_T    tv;
1513 
1514     while (!ends_excmd(*arg) && !got_int)
1515     {
1516 	if (error || eap->skip)
1517 	{
1518 	    arg = find_name_end(arg, NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1519 	    if (!VIM_ISWHITE(*arg) && !ends_excmd(*arg))
1520 	    {
1521 		emsg_severe = TRUE;
1522 		EMSG(_(e_trailing));
1523 		break;
1524 	    }
1525 	}
1526 	else
1527 	{
1528 	    /* get_name_len() takes care of expanding curly braces */
1529 	    name_start = name = arg;
1530 	    len = get_name_len(&arg, &tofree, TRUE, TRUE);
1531 	    if (len <= 0)
1532 	    {
1533 		/* This is mainly to keep test 49 working: when expanding
1534 		 * curly braces fails overrule the exception error message. */
1535 		if (len < 0 && !aborting())
1536 		{
1537 		    emsg_severe = TRUE;
1538 		    EMSG2(_(e_invarg2), arg);
1539 		    break;
1540 		}
1541 		error = TRUE;
1542 	    }
1543 	    else
1544 	    {
1545 		if (tofree != NULL)
1546 		    name = tofree;
1547 		if (get_var_tv(name, len, &tv, NULL, TRUE, FALSE) == FAIL)
1548 		    error = TRUE;
1549 		else
1550 		{
1551 		    /* handle d.key, l[idx], f(expr) */
1552 		    arg_subsc = arg;
1553 		    if (handle_subscript(&arg, &tv, TRUE, TRUE) == FAIL)
1554 			error = TRUE;
1555 		    else
1556 		    {
1557 			if (arg == arg_subsc && len == 2 && name[1] == ':')
1558 			{
1559 			    switch (*name)
1560 			    {
1561 				case 'g': list_glob_vars(first); break;
1562 				case 'b': list_buf_vars(first); break;
1563 				case 'w': list_win_vars(first); break;
1564 #ifdef FEAT_WINDOWS
1565 				case 't': list_tab_vars(first); break;
1566 #endif
1567 				case 'v': list_vim_vars(first); break;
1568 				case 's': list_script_vars(first); break;
1569 				case 'l': list_func_vars(first); break;
1570 				default:
1571 					  EMSG2(_("E738: Can't list variables for %s"), name);
1572 			    }
1573 			}
1574 			else
1575 			{
1576 			    char_u	numbuf[NUMBUFLEN];
1577 			    char_u	*tf;
1578 			    int		c;
1579 			    char_u	*s;
1580 
1581 			    s = echo_string(&tv, &tf, numbuf, 0);
1582 			    c = *arg;
1583 			    *arg = NUL;
1584 			    list_one_var_a((char_u *)"",
1585 				    arg == arg_subsc ? name : name_start,
1586 				    tv.v_type,
1587 				    s == NULL ? (char_u *)"" : s,
1588 				    first);
1589 			    *arg = c;
1590 			    vim_free(tf);
1591 			}
1592 			clear_tv(&tv);
1593 		    }
1594 		}
1595 	    }
1596 
1597 	    vim_free(tofree);
1598 	}
1599 
1600 	arg = skipwhite(arg);
1601     }
1602 
1603     return arg;
1604 }
1605 
1606 /*
1607  * Set one item of ":let var = expr" or ":let [v1, v2] = list" to its value.
1608  * Returns a pointer to the char just after the var name.
1609  * Returns NULL if there is an error.
1610  */
1611     static char_u *
1612 ex_let_one(
1613     char_u	*arg,		/* points to variable name */
1614     typval_T	*tv,		/* value to assign to variable */
1615     int		copy,		/* copy value from "tv" */
1616     char_u	*endchars,	/* valid chars after variable name  or NULL */
1617     char_u	*op)		/* "+", "-", "."  or NULL*/
1618 {
1619     int		c1;
1620     char_u	*name;
1621     char_u	*p;
1622     char_u	*arg_end = NULL;
1623     int		len;
1624     int		opt_flags;
1625     char_u	*tofree = NULL;
1626 
1627     /*
1628      * ":let $VAR = expr": Set environment variable.
1629      */
1630     if (*arg == '$')
1631     {
1632 	/* Find the end of the name. */
1633 	++arg;
1634 	name = arg;
1635 	len = get_env_len(&arg);
1636 	if (len == 0)
1637 	    EMSG2(_(e_invarg2), name - 1);
1638 	else
1639 	{
1640 	    if (op != NULL && (*op == '+' || *op == '-'))
1641 		EMSG2(_(e_letwrong), op);
1642 	    else if (endchars != NULL
1643 			     && vim_strchr(endchars, *skipwhite(arg)) == NULL)
1644 		EMSG(_(e_letunexp));
1645 	    else if (!check_secure())
1646 	    {
1647 		c1 = name[len];
1648 		name[len] = NUL;
1649 		p = get_tv_string_chk(tv);
1650 		if (p != NULL && op != NULL && *op == '.')
1651 		{
1652 		    int	    mustfree = FALSE;
1653 		    char_u  *s = vim_getenv(name, &mustfree);
1654 
1655 		    if (s != NULL)
1656 		    {
1657 			p = tofree = concat_str(s, p);
1658 			if (mustfree)
1659 			    vim_free(s);
1660 		    }
1661 		}
1662 		if (p != NULL)
1663 		{
1664 		    vim_setenv(name, p);
1665 		    if (STRICMP(name, "HOME") == 0)
1666 			init_homedir();
1667 		    else if (didset_vim && STRICMP(name, "VIM") == 0)
1668 			didset_vim = FALSE;
1669 		    else if (didset_vimruntime
1670 					&& STRICMP(name, "VIMRUNTIME") == 0)
1671 			didset_vimruntime = FALSE;
1672 		    arg_end = arg;
1673 		}
1674 		name[len] = c1;
1675 		vim_free(tofree);
1676 	    }
1677 	}
1678     }
1679 
1680     /*
1681      * ":let &option = expr": Set option value.
1682      * ":let &l:option = expr": Set local option value.
1683      * ":let &g:option = expr": Set global option value.
1684      */
1685     else if (*arg == '&')
1686     {
1687 	/* Find the end of the name. */
1688 	p = find_option_end(&arg, &opt_flags);
1689 	if (p == NULL || (endchars != NULL
1690 			      && vim_strchr(endchars, *skipwhite(p)) == NULL))
1691 	    EMSG(_(e_letunexp));
1692 	else
1693 	{
1694 	    long	n;
1695 	    int		opt_type;
1696 	    long	numval;
1697 	    char_u	*stringval = NULL;
1698 	    char_u	*s;
1699 
1700 	    c1 = *p;
1701 	    *p = NUL;
1702 
1703 	    n = (long)get_tv_number(tv);
1704 	    s = get_tv_string_chk(tv);	    /* != NULL if number or string */
1705 	    if (s != NULL && op != NULL && *op != '=')
1706 	    {
1707 		opt_type = get_option_value(arg, &numval,
1708 						       &stringval, opt_flags);
1709 		if ((opt_type == 1 && *op == '.')
1710 			|| (opt_type == 0 && *op != '.'))
1711 		    EMSG2(_(e_letwrong), op);
1712 		else
1713 		{
1714 		    if (opt_type == 1)  /* number */
1715 		    {
1716 			if (*op == '+')
1717 			    n = numval + n;
1718 			else
1719 			    n = numval - n;
1720 		    }
1721 		    else if (opt_type == 0 && stringval != NULL) /* string */
1722 		    {
1723 			s = concat_str(stringval, s);
1724 			vim_free(stringval);
1725 			stringval = s;
1726 		    }
1727 		}
1728 	    }
1729 	    if (s != NULL)
1730 	    {
1731 		set_option_value(arg, n, s, opt_flags);
1732 		arg_end = p;
1733 	    }
1734 	    *p = c1;
1735 	    vim_free(stringval);
1736 	}
1737     }
1738 
1739     /*
1740      * ":let @r = expr": Set register contents.
1741      */
1742     else if (*arg == '@')
1743     {
1744 	++arg;
1745 	if (op != NULL && (*op == '+' || *op == '-'))
1746 	    EMSG2(_(e_letwrong), op);
1747 	else if (endchars != NULL
1748 			 && vim_strchr(endchars, *skipwhite(arg + 1)) == NULL)
1749 	    EMSG(_(e_letunexp));
1750 	else
1751 	{
1752 	    char_u	*ptofree = NULL;
1753 	    char_u	*s;
1754 
1755 	    p = get_tv_string_chk(tv);
1756 	    if (p != NULL && op != NULL && *op == '.')
1757 	    {
1758 		s = get_reg_contents(*arg == '@' ? '"' : *arg, GREG_EXPR_SRC);
1759 		if (s != NULL)
1760 		{
1761 		    p = ptofree = concat_str(s, p);
1762 		    vim_free(s);
1763 		}
1764 	    }
1765 	    if (p != NULL)
1766 	    {
1767 		write_reg_contents(*arg == '@' ? '"' : *arg, p, -1, FALSE);
1768 		arg_end = arg + 1;
1769 	    }
1770 	    vim_free(ptofree);
1771 	}
1772     }
1773 
1774     /*
1775      * ":let var = expr": Set internal variable.
1776      * ":let {expr} = expr": Idem, name made with curly braces
1777      */
1778     else if (eval_isnamec1(*arg) || *arg == '{')
1779     {
1780 	lval_T	lv;
1781 
1782 	p = get_lval(arg, tv, &lv, FALSE, FALSE, 0, FNE_CHECK_START);
1783 	if (p != NULL && lv.ll_name != NULL)
1784 	{
1785 	    if (endchars != NULL && vim_strchr(endchars, *skipwhite(p)) == NULL)
1786 		EMSG(_(e_letunexp));
1787 	    else
1788 	    {
1789 		set_var_lval(&lv, p, tv, copy, op);
1790 		arg_end = p;
1791 	    }
1792 	}
1793 	clear_lval(&lv);
1794     }
1795 
1796     else
1797 	EMSG2(_(e_invarg2), arg);
1798 
1799     return arg_end;
1800 }
1801 
1802 /*
1803  * Get an lval: variable, Dict item or List item that can be assigned a value
1804  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
1805  * "name.key", "name.key[expr]" etc.
1806  * Indexing only works if "name" is an existing List or Dictionary.
1807  * "name" points to the start of the name.
1808  * If "rettv" is not NULL it points to the value to be assigned.
1809  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
1810  * wrong; must end in space or cmd separator.
1811  *
1812  * flags:
1813  *  GLV_QUIET:       do not give error messages
1814  *  GLV_READ_ONLY:   will not change the variable
1815  *  GLV_NO_AUTOLOAD: do not use script autoloading
1816  *
1817  * Returns a pointer to just after the name, including indexes.
1818  * When an evaluation error occurs "lp->ll_name" is NULL;
1819  * Returns NULL for a parsing error.  Still need to free items in "lp"!
1820  */
1821     char_u *
1822 get_lval(
1823     char_u	*name,
1824     typval_T	*rettv,
1825     lval_T	*lp,
1826     int		unlet,
1827     int		skip,
1828     int		flags,	    /* GLV_ values */
1829     int		fne_flags)  /* flags for find_name_end() */
1830 {
1831     char_u	*p;
1832     char_u	*expr_start, *expr_end;
1833     int		cc;
1834     dictitem_T	*v;
1835     typval_T	var1;
1836     typval_T	var2;
1837     int		empty1 = FALSE;
1838     listitem_T	*ni;
1839     char_u	*key = NULL;
1840     int		len;
1841     hashtab_T	*ht;
1842     int		quiet = flags & GLV_QUIET;
1843 
1844     /* Clear everything in "lp". */
1845     vim_memset(lp, 0, sizeof(lval_T));
1846 
1847     if (skip)
1848     {
1849 	/* When skipping just find the end of the name. */
1850 	lp->ll_name = name;
1851 	return find_name_end(name, NULL, NULL, FNE_INCL_BR | fne_flags);
1852     }
1853 
1854     /* Find the end of the name. */
1855     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
1856     if (expr_start != NULL)
1857     {
1858 	/* Don't expand the name when we already know there is an error. */
1859 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
1860 						    && *p != '[' && *p != '.')
1861 	{
1862 	    EMSG(_(e_trailing));
1863 	    return NULL;
1864 	}
1865 
1866 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
1867 	if (lp->ll_exp_name == NULL)
1868 	{
1869 	    /* Report an invalid expression in braces, unless the
1870 	     * expression evaluation has been cancelled due to an
1871 	     * aborting error, an interrupt, or an exception. */
1872 	    if (!aborting() && !quiet)
1873 	    {
1874 		emsg_severe = TRUE;
1875 		EMSG2(_(e_invarg2), name);
1876 		return NULL;
1877 	    }
1878 	}
1879 	lp->ll_name = lp->ll_exp_name;
1880     }
1881     else
1882 	lp->ll_name = name;
1883 
1884     /* Without [idx] or .key we are done. */
1885     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
1886 	return p;
1887 
1888     cc = *p;
1889     *p = NUL;
1890     v = find_var(lp->ll_name, &ht, flags & GLV_NO_AUTOLOAD);
1891     if (v == NULL && !quiet)
1892 	EMSG2(_(e_undefvar), lp->ll_name);
1893     *p = cc;
1894     if (v == NULL)
1895 	return NULL;
1896 
1897     /*
1898      * Loop until no more [idx] or .key is following.
1899      */
1900     lp->ll_tv = &v->di_tv;
1901     var1.v_type = VAR_UNKNOWN;
1902     var2.v_type = VAR_UNKNOWN;
1903     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
1904     {
1905 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
1906 		&& !(lp->ll_tv->v_type == VAR_DICT
1907 					   && lp->ll_tv->vval.v_dict != NULL))
1908 	{
1909 	    if (!quiet)
1910 		EMSG(_("E689: Can only index a List or Dictionary"));
1911 	    return NULL;
1912 	}
1913 	if (lp->ll_range)
1914 	{
1915 	    if (!quiet)
1916 		EMSG(_("E708: [:] must come last"));
1917 	    return NULL;
1918 	}
1919 
1920 	len = -1;
1921 	if (*p == '.')
1922 	{
1923 	    key = p + 1;
1924 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
1925 		;
1926 	    if (len == 0)
1927 	    {
1928 		if (!quiet)
1929 		    EMSG(_(e_emptykey));
1930 		return NULL;
1931 	    }
1932 	    p = key + len;
1933 	}
1934 	else
1935 	{
1936 	    /* Get the index [expr] or the first index [expr: ]. */
1937 	    p = skipwhite(p + 1);
1938 	    if (*p == ':')
1939 		empty1 = TRUE;
1940 	    else
1941 	    {
1942 		empty1 = FALSE;
1943 		if (eval1(&p, &var1, TRUE) == FAIL)	/* recursive! */
1944 		    return NULL;
1945 		if (get_tv_string_chk(&var1) == NULL)
1946 		{
1947 		    /* not a number or string */
1948 		    clear_tv(&var1);
1949 		    return NULL;
1950 		}
1951 	    }
1952 
1953 	    /* Optionally get the second index [ :expr]. */
1954 	    if (*p == ':')
1955 	    {
1956 		if (lp->ll_tv->v_type == VAR_DICT)
1957 		{
1958 		    if (!quiet)
1959 			EMSG(_(e_dictrange));
1960 		    clear_tv(&var1);
1961 		    return NULL;
1962 		}
1963 		if (rettv != NULL && (rettv->v_type != VAR_LIST
1964 					       || rettv->vval.v_list == NULL))
1965 		{
1966 		    if (!quiet)
1967 			EMSG(_("E709: [:] requires a List value"));
1968 		    clear_tv(&var1);
1969 		    return NULL;
1970 		}
1971 		p = skipwhite(p + 1);
1972 		if (*p == ']')
1973 		    lp->ll_empty2 = TRUE;
1974 		else
1975 		{
1976 		    lp->ll_empty2 = FALSE;
1977 		    if (eval1(&p, &var2, TRUE) == FAIL)	/* recursive! */
1978 		    {
1979 			clear_tv(&var1);
1980 			return NULL;
1981 		    }
1982 		    if (get_tv_string_chk(&var2) == NULL)
1983 		    {
1984 			/* not a number or string */
1985 			clear_tv(&var1);
1986 			clear_tv(&var2);
1987 			return NULL;
1988 		    }
1989 		}
1990 		lp->ll_range = TRUE;
1991 	    }
1992 	    else
1993 		lp->ll_range = FALSE;
1994 
1995 	    if (*p != ']')
1996 	    {
1997 		if (!quiet)
1998 		    EMSG(_(e_missbrac));
1999 		clear_tv(&var1);
2000 		clear_tv(&var2);
2001 		return NULL;
2002 	    }
2003 
2004 	    /* Skip to past ']'. */
2005 	    ++p;
2006 	}
2007 
2008 	if (lp->ll_tv->v_type == VAR_DICT)
2009 	{
2010 	    if (len == -1)
2011 	    {
2012 		/* "[key]": get key from "var1" */
2013 		key = get_tv_string_chk(&var1);	/* is number or string */
2014 		if (key == NULL)
2015 		{
2016 		    clear_tv(&var1);
2017 		    return NULL;
2018 		}
2019 	    }
2020 	    lp->ll_list = NULL;
2021 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
2022 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
2023 
2024 	    /* When assigning to a scope dictionary check that a function and
2025 	     * variable name is valid (only variable name unless it is l: or
2026 	     * g: dictionary). Disallow overwriting a builtin function. */
2027 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
2028 	    {
2029 		int prevval;
2030 		int wrong;
2031 
2032 		if (len != -1)
2033 		{
2034 		    prevval = key[len];
2035 		    key[len] = NUL;
2036 		}
2037 		else
2038 		    prevval = 0; /* avoid compiler warning */
2039 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
2040 			       && rettv->v_type == VAR_FUNC
2041 			       && var_check_func_name(key, lp->ll_di == NULL))
2042 			|| !valid_varname(key);
2043 		if (len != -1)
2044 		    key[len] = prevval;
2045 		if (wrong)
2046 		    return NULL;
2047 	    }
2048 
2049 	    if (lp->ll_di == NULL)
2050 	    {
2051 		/* Can't add "v:" variable. */
2052 		if (lp->ll_dict == &vimvardict)
2053 		{
2054 		    EMSG2(_(e_illvar), name);
2055 		    return NULL;
2056 		}
2057 
2058 		/* Key does not exist in dict: may need to add it. */
2059 		if (*p == '[' || *p == '.' || unlet)
2060 		{
2061 		    if (!quiet)
2062 			EMSG2(_(e_dictkey), key);
2063 		    clear_tv(&var1);
2064 		    return NULL;
2065 		}
2066 		if (len == -1)
2067 		    lp->ll_newkey = vim_strsave(key);
2068 		else
2069 		    lp->ll_newkey = vim_strnsave(key, len);
2070 		clear_tv(&var1);
2071 		if (lp->ll_newkey == NULL)
2072 		    p = NULL;
2073 		break;
2074 	    }
2075 	    /* existing variable, need to check if it can be changed */
2076 	    else if ((flags & GLV_READ_ONLY) == 0
2077 			     && var_check_ro(lp->ll_di->di_flags, name, FALSE))
2078 	    {
2079 		clear_tv(&var1);
2080 		return NULL;
2081 	    }
2082 
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 		/* is number or string */
2095 		lp->ll_n1 = (long)get_tv_number(&var1);
2096 	    clear_tv(&var1);
2097 
2098 	    lp->ll_dict = NULL;
2099 	    lp->ll_list = lp->ll_tv->vval.v_list;
2100 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2101 	    if (lp->ll_li == NULL)
2102 	    {
2103 		if (lp->ll_n1 < 0)
2104 		{
2105 		    lp->ll_n1 = 0;
2106 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2107 		}
2108 	    }
2109 	    if (lp->ll_li == NULL)
2110 	    {
2111 		clear_tv(&var2);
2112 		if (!quiet)
2113 		    EMSGN(_(e_listidx), lp->ll_n1);
2114 		return NULL;
2115 	    }
2116 
2117 	    /*
2118 	     * May need to find the item or absolute index for the second
2119 	     * index of a range.
2120 	     * When no index given: "lp->ll_empty2" is TRUE.
2121 	     * Otherwise "lp->ll_n2" is set to the second index.
2122 	     */
2123 	    if (lp->ll_range && !lp->ll_empty2)
2124 	    {
2125 		lp->ll_n2 = (long)get_tv_number(&var2);
2126 						    /* is number or string */
2127 		clear_tv(&var2);
2128 		if (lp->ll_n2 < 0)
2129 		{
2130 		    ni = list_find(lp->ll_list, lp->ll_n2);
2131 		    if (ni == NULL)
2132 		    {
2133 			if (!quiet)
2134 			    EMSGN(_(e_listidx), lp->ll_n2);
2135 			return NULL;
2136 		    }
2137 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
2138 		}
2139 
2140 		/* Check that lp->ll_n2 isn't before lp->ll_n1. */
2141 		if (lp->ll_n1 < 0)
2142 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
2143 		if (lp->ll_n2 < lp->ll_n1)
2144 		{
2145 		    if (!quiet)
2146 			EMSGN(_(e_listidx), lp->ll_n2);
2147 		    return NULL;
2148 		}
2149 	    }
2150 
2151 	    lp->ll_tv = &lp->ll_li->li_tv;
2152 	}
2153     }
2154 
2155     clear_tv(&var1);
2156     return p;
2157 }
2158 
2159 /*
2160  * Clear lval "lp" that was filled by get_lval().
2161  */
2162     void
2163 clear_lval(lval_T *lp)
2164 {
2165     vim_free(lp->ll_exp_name);
2166     vim_free(lp->ll_newkey);
2167 }
2168 
2169 /*
2170  * Set a variable that was parsed by get_lval() to "rettv".
2171  * "endp" points to just after the parsed name.
2172  * "op" is NULL, "+" for "+=", "-" for "-=", "." for ".=" or "=" for "=".
2173  */
2174     static void
2175 set_var_lval(
2176     lval_T	*lp,
2177     char_u	*endp,
2178     typval_T	*rettv,
2179     int		copy,
2180     char_u	*op)
2181 {
2182     int		cc;
2183     listitem_T	*ri;
2184     dictitem_T	*di;
2185 
2186     if (lp->ll_tv == NULL)
2187     {
2188 	cc = *endp;
2189 	*endp = NUL;
2190 	if (op != NULL && *op != '=')
2191 	{
2192 	    typval_T tv;
2193 
2194 	    /* handle +=, -= and .= */
2195 	    di = NULL;
2196 	    if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
2197 					     &tv, &di, TRUE, FALSE) == OK)
2198 	    {
2199 		if ((di == NULL
2200 		       || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
2201 			  && !tv_check_lock(di->di_tv.v_lock, lp->ll_name,
2202 								  FALSE)))
2203 			&& tv_op(&tv, rettv, op) == OK)
2204 		    set_var(lp->ll_name, &tv, FALSE);
2205 		clear_tv(&tv);
2206 	    }
2207 	}
2208 	else
2209 	    set_var(lp->ll_name, rettv, copy);
2210 	*endp = cc;
2211     }
2212     else if (tv_check_lock(lp->ll_newkey == NULL
2213 		? lp->ll_tv->v_lock
2214 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
2215 	;
2216     else if (lp->ll_range)
2217     {
2218 	listitem_T *ll_li = lp->ll_li;
2219 	int ll_n1 = lp->ll_n1;
2220 
2221 	/*
2222 	 * Check whether any of the list items is locked
2223 	 */
2224 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
2225 	{
2226 	    if (tv_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
2227 		return;
2228 	    ri = ri->li_next;
2229 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
2230 		break;
2231 	    ll_li = ll_li->li_next;
2232 	    ++ll_n1;
2233 	}
2234 
2235 	/*
2236 	 * Assign the List values to the list items.
2237 	 */
2238 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
2239 	{
2240 	    if (op != NULL && *op != '=')
2241 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
2242 	    else
2243 	    {
2244 		clear_tv(&lp->ll_li->li_tv);
2245 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
2246 	    }
2247 	    ri = ri->li_next;
2248 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
2249 		break;
2250 	    if (lp->ll_li->li_next == NULL)
2251 	    {
2252 		/* Need to add an empty item. */
2253 		if (list_append_number(lp->ll_list, 0) == FAIL)
2254 		{
2255 		    ri = NULL;
2256 		    break;
2257 		}
2258 	    }
2259 	    lp->ll_li = lp->ll_li->li_next;
2260 	    ++lp->ll_n1;
2261 	}
2262 	if (ri != NULL)
2263 	    EMSG(_("E710: List value has more items than target"));
2264 	else if (lp->ll_empty2
2265 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
2266 		: lp->ll_n1 != lp->ll_n2)
2267 	    EMSG(_("E711: List value has not enough items"));
2268     }
2269     else
2270     {
2271 	/*
2272 	 * Assign to a List or Dictionary item.
2273 	 */
2274 	if (lp->ll_newkey != NULL)
2275 	{
2276 	    if (op != NULL && *op != '=')
2277 	    {
2278 		EMSG2(_(e_letwrong), op);
2279 		return;
2280 	    }
2281 
2282 	    /* Need to add an item to the Dictionary. */
2283 	    di = dictitem_alloc(lp->ll_newkey);
2284 	    if (di == NULL)
2285 		return;
2286 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
2287 	    {
2288 		vim_free(di);
2289 		return;
2290 	    }
2291 	    lp->ll_tv = &di->di_tv;
2292 	}
2293 	else if (op != NULL && *op != '=')
2294 	{
2295 	    tv_op(lp->ll_tv, rettv, op);
2296 	    return;
2297 	}
2298 	else
2299 	    clear_tv(lp->ll_tv);
2300 
2301 	/*
2302 	 * Assign the value to the variable or list item.
2303 	 */
2304 	if (copy)
2305 	    copy_tv(rettv, lp->ll_tv);
2306 	else
2307 	{
2308 	    *lp->ll_tv = *rettv;
2309 	    lp->ll_tv->v_lock = 0;
2310 	    init_tv(rettv);
2311 	}
2312     }
2313 }
2314 
2315 /*
2316  * Handle "tv1 += tv2", "tv1 -= tv2" and "tv1 .= tv2"
2317  * Returns OK or FAIL.
2318  */
2319     static int
2320 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
2321 {
2322     varnumber_T	n;
2323     char_u	numbuf[NUMBUFLEN];
2324     char_u	*s;
2325 
2326     /* Can't do anything with a Funcref, Dict, v:true on the right. */
2327     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
2328 						&& tv2->v_type != VAR_SPECIAL)
2329     {
2330 	switch (tv1->v_type)
2331 	{
2332 	    case VAR_UNKNOWN:
2333 	    case VAR_DICT:
2334 	    case VAR_FUNC:
2335 	    case VAR_PARTIAL:
2336 	    case VAR_SPECIAL:
2337 	    case VAR_JOB:
2338 	    case VAR_CHANNEL:
2339 		break;
2340 
2341 	    case VAR_LIST:
2342 		if (*op != '+' || tv2->v_type != VAR_LIST)
2343 		    break;
2344 		/* List += List */
2345 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
2346 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
2347 		return OK;
2348 
2349 	    case VAR_NUMBER:
2350 	    case VAR_STRING:
2351 		if (tv2->v_type == VAR_LIST)
2352 		    break;
2353 		if (*op == '+' || *op == '-')
2354 		{
2355 		    /* nr += nr  or  nr -= nr*/
2356 		    n = get_tv_number(tv1);
2357 #ifdef FEAT_FLOAT
2358 		    if (tv2->v_type == VAR_FLOAT)
2359 		    {
2360 			float_T f = n;
2361 
2362 			if (*op == '+')
2363 			    f += tv2->vval.v_float;
2364 			else
2365 			    f -= tv2->vval.v_float;
2366 			clear_tv(tv1);
2367 			tv1->v_type = VAR_FLOAT;
2368 			tv1->vval.v_float = f;
2369 		    }
2370 		    else
2371 #endif
2372 		    {
2373 			if (*op == '+')
2374 			    n += get_tv_number(tv2);
2375 			else
2376 			    n -= get_tv_number(tv2);
2377 			clear_tv(tv1);
2378 			tv1->v_type = VAR_NUMBER;
2379 			tv1->vval.v_number = n;
2380 		    }
2381 		}
2382 		else
2383 		{
2384 		    if (tv2->v_type == VAR_FLOAT)
2385 			break;
2386 
2387 		    /* str .= str */
2388 		    s = get_tv_string(tv1);
2389 		    s = concat_str(s, get_tv_string_buf(tv2, numbuf));
2390 		    clear_tv(tv1);
2391 		    tv1->v_type = VAR_STRING;
2392 		    tv1->vval.v_string = s;
2393 		}
2394 		return OK;
2395 
2396 	    case VAR_FLOAT:
2397 #ifdef FEAT_FLOAT
2398 		{
2399 		    float_T f;
2400 
2401 		    if (*op == '.' || (tv2->v_type != VAR_FLOAT
2402 				    && tv2->v_type != VAR_NUMBER
2403 				    && tv2->v_type != VAR_STRING))
2404 			break;
2405 		    if (tv2->v_type == VAR_FLOAT)
2406 			f = tv2->vval.v_float;
2407 		    else
2408 			f = get_tv_number(tv2);
2409 		    if (*op == '+')
2410 			tv1->vval.v_float += f;
2411 		    else
2412 			tv1->vval.v_float -= f;
2413 		}
2414 #endif
2415 		return OK;
2416 	}
2417     }
2418 
2419     EMSG2(_(e_letwrong), op);
2420     return FAIL;
2421 }
2422 
2423 /*
2424  * Evaluate the expression used in a ":for var in expr" command.
2425  * "arg" points to "var".
2426  * Set "*errp" to TRUE for an error, FALSE otherwise;
2427  * Return a pointer that holds the info.  Null when there is an error.
2428  */
2429     void *
2430 eval_for_line(
2431     char_u	*arg,
2432     int		*errp,
2433     char_u	**nextcmdp,
2434     int		skip)
2435 {
2436     forinfo_T	*fi;
2437     char_u	*expr;
2438     typval_T	tv;
2439     list_T	*l;
2440 
2441     *errp = TRUE;	/* default: there is an error */
2442 
2443     fi = (forinfo_T *)alloc_clear(sizeof(forinfo_T));
2444     if (fi == NULL)
2445 	return NULL;
2446 
2447     expr = skip_var_list(arg, &fi->fi_varcount, &fi->fi_semicolon);
2448     if (expr == NULL)
2449 	return fi;
2450 
2451     expr = skipwhite(expr);
2452     if (expr[0] != 'i' || expr[1] != 'n' || !VIM_ISWHITE(expr[2]))
2453     {
2454 	EMSG(_("E690: Missing \"in\" after :for"));
2455 	return fi;
2456     }
2457 
2458     if (skip)
2459 	++emsg_skip;
2460     if (eval0(skipwhite(expr + 2), &tv, nextcmdp, !skip) == OK)
2461     {
2462 	*errp = FALSE;
2463 	if (!skip)
2464 	{
2465 	    l = tv.vval.v_list;
2466 	    if (tv.v_type != VAR_LIST)
2467 	    {
2468 		EMSG(_(e_listreq));
2469 		clear_tv(&tv);
2470 	    }
2471 	    else if (l == NULL)
2472 	    {
2473 		/* a null list is like an empty list: do nothing */
2474 		clear_tv(&tv);
2475 	    }
2476 	    else
2477 	    {
2478 		/* No need to increment the refcount, it's already set for the
2479 		 * list being used in "tv". */
2480 		fi->fi_list = l;
2481 		list_add_watch(l, &fi->fi_lw);
2482 		fi->fi_lw.lw_item = l->lv_first;
2483 	    }
2484 	}
2485     }
2486     if (skip)
2487 	--emsg_skip;
2488 
2489     return fi;
2490 }
2491 
2492 /*
2493  * Use the first item in a ":for" list.  Advance to the next.
2494  * Assign the values to the variable (list).  "arg" points to the first one.
2495  * Return TRUE when a valid item was found, FALSE when at end of list or
2496  * something wrong.
2497  */
2498     int
2499 next_for_item(void *fi_void, char_u *arg)
2500 {
2501     forinfo_T	*fi = (forinfo_T *)fi_void;
2502     int		result;
2503     listitem_T	*item;
2504 
2505     item = fi->fi_lw.lw_item;
2506     if (item == NULL)
2507 	result = FALSE;
2508     else
2509     {
2510 	fi->fi_lw.lw_item = item->li_next;
2511 	result = (ex_let_vars(arg, &item->li_tv, TRUE,
2512 			      fi->fi_semicolon, fi->fi_varcount, NULL) == OK);
2513     }
2514     return result;
2515 }
2516 
2517 /*
2518  * Free the structure used to store info used by ":for".
2519  */
2520     void
2521 free_for_info(void *fi_void)
2522 {
2523     forinfo_T    *fi = (forinfo_T *)fi_void;
2524 
2525     if (fi != NULL && fi->fi_list != NULL)
2526     {
2527 	list_rem_watch(fi->fi_list, &fi->fi_lw);
2528 	list_unref(fi->fi_list);
2529     }
2530     vim_free(fi);
2531 }
2532 
2533 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
2534 
2535     void
2536 set_context_for_expression(
2537     expand_T	*xp,
2538     char_u	*arg,
2539     cmdidx_T	cmdidx)
2540 {
2541     int		got_eq = FALSE;
2542     int		c;
2543     char_u	*p;
2544 
2545     if (cmdidx == CMD_let)
2546     {
2547 	xp->xp_context = EXPAND_USER_VARS;
2548 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
2549 	{
2550 	    /* ":let var1 var2 ...": find last space. */
2551 	    for (p = arg + STRLEN(arg); p >= arg; )
2552 	    {
2553 		xp->xp_pattern = p;
2554 		MB_PTR_BACK(arg, p);
2555 		if (VIM_ISWHITE(*p))
2556 		    break;
2557 	    }
2558 	    return;
2559 	}
2560     }
2561     else
2562 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
2563 							  : EXPAND_EXPRESSION;
2564     while ((xp->xp_pattern = vim_strpbrk(arg,
2565 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
2566     {
2567 	c = *xp->xp_pattern;
2568 	if (c == '&')
2569 	{
2570 	    c = xp->xp_pattern[1];
2571 	    if (c == '&')
2572 	    {
2573 		++xp->xp_pattern;
2574 		xp->xp_context = cmdidx != CMD_let || got_eq
2575 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
2576 	    }
2577 	    else if (c != ' ')
2578 	    {
2579 		xp->xp_context = EXPAND_SETTINGS;
2580 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
2581 		    xp->xp_pattern += 2;
2582 
2583 	    }
2584 	}
2585 	else if (c == '$')
2586 	{
2587 	    /* environment variable */
2588 	    xp->xp_context = EXPAND_ENV_VARS;
2589 	}
2590 	else if (c == '=')
2591 	{
2592 	    got_eq = TRUE;
2593 	    xp->xp_context = EXPAND_EXPRESSION;
2594 	}
2595 	else if (c == '#'
2596 		&& xp->xp_context == EXPAND_EXPRESSION)
2597 	{
2598 	    /* Autoload function/variable contains '#'. */
2599 	    break;
2600 	}
2601 	else if ((c == '<' || c == '#')
2602 		&& xp->xp_context == EXPAND_FUNCTIONS
2603 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
2604 	{
2605 	    /* Function name can start with "<SNR>" and contain '#'. */
2606 	    break;
2607 	}
2608 	else if (cmdidx != CMD_let || got_eq)
2609 	{
2610 	    if (c == '"')	    /* string */
2611 	    {
2612 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
2613 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
2614 			++xp->xp_pattern;
2615 		xp->xp_context = EXPAND_NOTHING;
2616 	    }
2617 	    else if (c == '\'')	    /* literal string */
2618 	    {
2619 		/* Trick: '' is like stopping and starting a literal string. */
2620 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
2621 		    /* skip */ ;
2622 		xp->xp_context = EXPAND_NOTHING;
2623 	    }
2624 	    else if (c == '|')
2625 	    {
2626 		if (xp->xp_pattern[1] == '|')
2627 		{
2628 		    ++xp->xp_pattern;
2629 		    xp->xp_context = EXPAND_EXPRESSION;
2630 		}
2631 		else
2632 		    xp->xp_context = EXPAND_COMMANDS;
2633 	    }
2634 	    else
2635 		xp->xp_context = EXPAND_EXPRESSION;
2636 	}
2637 	else
2638 	    /* Doesn't look like something valid, expand as an expression
2639 	     * anyway. */
2640 	    xp->xp_context = EXPAND_EXPRESSION;
2641 	arg = xp->xp_pattern;
2642 	if (*arg != NUL)
2643 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
2644 		/* skip */ ;
2645     }
2646     xp->xp_pattern = arg;
2647 }
2648 
2649 #endif /* FEAT_CMDL_COMPL */
2650 
2651 /*
2652  * ":unlet[!] var1 ... " command.
2653  */
2654     void
2655 ex_unlet(exarg_T *eap)
2656 {
2657     ex_unletlock(eap, eap->arg, 0);
2658 }
2659 
2660 /*
2661  * ":lockvar" and ":unlockvar" commands
2662  */
2663     void
2664 ex_lockvar(exarg_T *eap)
2665 {
2666     char_u	*arg = eap->arg;
2667     int		deep = 2;
2668 
2669     if (eap->forceit)
2670 	deep = -1;
2671     else if (vim_isdigit(*arg))
2672     {
2673 	deep = getdigits(&arg);
2674 	arg = skipwhite(arg);
2675     }
2676 
2677     ex_unletlock(eap, arg, deep);
2678 }
2679 
2680 /*
2681  * ":unlet", ":lockvar" and ":unlockvar" are quite similar.
2682  */
2683     static void
2684 ex_unletlock(
2685     exarg_T	*eap,
2686     char_u	*argstart,
2687     int		deep)
2688 {
2689     char_u	*arg = argstart;
2690     char_u	*name_end;
2691     int		error = FALSE;
2692     lval_T	lv;
2693 
2694     do
2695     {
2696 	/* Parse the name and find the end. */
2697 	name_end = get_lval(arg, NULL, &lv, TRUE, eap->skip || error, 0,
2698 							     FNE_CHECK_START);
2699 	if (lv.ll_name == NULL)
2700 	    error = TRUE;	    /* error but continue parsing */
2701 	if (name_end == NULL || (!VIM_ISWHITE(*name_end)
2702 						   && !ends_excmd(*name_end)))
2703 	{
2704 	    if (name_end != NULL)
2705 	    {
2706 		emsg_severe = TRUE;
2707 		EMSG(_(e_trailing));
2708 	    }
2709 	    if (!(eap->skip || error))
2710 		clear_lval(&lv);
2711 	    break;
2712 	}
2713 
2714 	if (!error && !eap->skip)
2715 	{
2716 	    if (eap->cmdidx == CMD_unlet)
2717 	    {
2718 		if (do_unlet_var(&lv, name_end, eap->forceit) == FAIL)
2719 		    error = TRUE;
2720 	    }
2721 	    else
2722 	    {
2723 		if (do_lock_var(&lv, name_end, deep,
2724 					  eap->cmdidx == CMD_lockvar) == FAIL)
2725 		    error = TRUE;
2726 	    }
2727 	}
2728 
2729 	if (!eap->skip)
2730 	    clear_lval(&lv);
2731 
2732 	arg = skipwhite(name_end);
2733     } while (!ends_excmd(*arg));
2734 
2735     eap->nextcmd = check_nextcmd(arg);
2736 }
2737 
2738     static int
2739 do_unlet_var(
2740     lval_T	*lp,
2741     char_u	*name_end,
2742     int		forceit)
2743 {
2744     int		ret = OK;
2745     int		cc;
2746 
2747     if (lp->ll_tv == NULL)
2748     {
2749 	cc = *name_end;
2750 	*name_end = NUL;
2751 
2752 	/* Normal name or expanded name. */
2753 	if (do_unlet(lp->ll_name, forceit) == FAIL)
2754 	    ret = FAIL;
2755 	*name_end = cc;
2756     }
2757     else if ((lp->ll_list != NULL
2758 		   && tv_check_lock(lp->ll_list->lv_lock, lp->ll_name, FALSE))
2759 	    || (lp->ll_dict != NULL
2760 		  && tv_check_lock(lp->ll_dict->dv_lock, lp->ll_name, FALSE)))
2761 	return FAIL;
2762     else if (lp->ll_range)
2763     {
2764 	listitem_T    *li;
2765 	listitem_T    *ll_li = lp->ll_li;
2766 	int	      ll_n1 = lp->ll_n1;
2767 
2768 	while (ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= ll_n1))
2769 	{
2770 	    li = ll_li->li_next;
2771 	    if (tv_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
2772 		return FAIL;
2773 	    ll_li = li;
2774 	    ++ll_n1;
2775 	}
2776 
2777 	/* Delete a range of List items. */
2778 	while (lp->ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
2779 	{
2780 	    li = lp->ll_li->li_next;
2781 	    listitem_remove(lp->ll_list, lp->ll_li);
2782 	    lp->ll_li = li;
2783 	    ++lp->ll_n1;
2784 	}
2785     }
2786     else
2787     {
2788 	if (lp->ll_list != NULL)
2789 	    /* unlet a List item. */
2790 	    listitem_remove(lp->ll_list, lp->ll_li);
2791 	else
2792 	    /* unlet a Dictionary item. */
2793 	    dictitem_remove(lp->ll_dict, lp->ll_di);
2794     }
2795 
2796     return ret;
2797 }
2798 
2799 /*
2800  * "unlet" a variable.  Return OK if it existed, FAIL if not.
2801  * When "forceit" is TRUE don't complain if the variable doesn't exist.
2802  */
2803     int
2804 do_unlet(char_u *name, int forceit)
2805 {
2806     hashtab_T	*ht;
2807     hashitem_T	*hi;
2808     char_u	*varname;
2809     dict_T	*d;
2810     dictitem_T	*di;
2811 
2812     ht = find_var_ht(name, &varname);
2813     if (ht != NULL && *varname != NUL)
2814     {
2815 	d = get_current_funccal_dict(ht);
2816 	if (d == NULL)
2817 	{
2818 	    if (ht == &globvarht)
2819 		d = &globvardict;
2820 	    else if (ht == &compat_hashtab)
2821 		d = &vimvardict;
2822 	    else
2823 	    {
2824 		di = find_var_in_ht(ht, *name, (char_u *)"", FALSE);
2825 		d = di == NULL ? NULL : di->di_tv.vval.v_dict;
2826 	    }
2827 	    if (d == NULL)
2828 	    {
2829 		internal_error("do_unlet()");
2830 		return FAIL;
2831 	    }
2832 	}
2833 	hi = hash_find(ht, varname);
2834 	if (HASHITEM_EMPTY(hi))
2835 	    hi = find_hi_in_scoped_ht(name, &ht);
2836 	if (hi != NULL && !HASHITEM_EMPTY(hi))
2837 	{
2838 	    di = HI2DI(hi);
2839 	    if (var_check_fixed(di->di_flags, name, FALSE)
2840 		    || var_check_ro(di->di_flags, name, FALSE)
2841 		    || tv_check_lock(d->dv_lock, name, FALSE))
2842 		return FAIL;
2843 
2844 	    delete_var(ht, hi);
2845 	    return OK;
2846 	}
2847     }
2848     if (forceit)
2849 	return OK;
2850     EMSG2(_("E108: No such variable: \"%s\""), name);
2851     return FAIL;
2852 }
2853 
2854 /*
2855  * Lock or unlock variable indicated by "lp".
2856  * "deep" is the levels to go (-1 for unlimited);
2857  * "lock" is TRUE for ":lockvar", FALSE for ":unlockvar".
2858  */
2859     static int
2860 do_lock_var(
2861     lval_T	*lp,
2862     char_u	*name_end,
2863     int		deep,
2864     int		lock)
2865 {
2866     int		ret = OK;
2867     int		cc;
2868     dictitem_T	*di;
2869 
2870     if (deep == 0)	/* nothing to do */
2871 	return OK;
2872 
2873     if (lp->ll_tv == NULL)
2874     {
2875 	cc = *name_end;
2876 	*name_end = NUL;
2877 
2878 	/* Normal name or expanded name. */
2879 	di = find_var(lp->ll_name, NULL, TRUE);
2880 	if (di == NULL)
2881 	    ret = FAIL;
2882 	else if ((di->di_flags & DI_FLAGS_FIX)
2883 			&& di->di_tv.v_type != VAR_DICT
2884 			&& di->di_tv.v_type != VAR_LIST)
2885 	    /* For historic reasons this error is not given for a list or dict.
2886 	     * E.g., the b: dict could be locked/unlocked. */
2887 	    EMSG2(_("E940: Cannot lock or unlock variable %s"), lp->ll_name);
2888 	else
2889 	{
2890 	    if (lock)
2891 		di->di_flags |= DI_FLAGS_LOCK;
2892 	    else
2893 		di->di_flags &= ~DI_FLAGS_LOCK;
2894 	    item_lock(&di->di_tv, deep, lock);
2895 	}
2896 	*name_end = cc;
2897     }
2898     else if (lp->ll_range)
2899     {
2900 	listitem_T    *li = lp->ll_li;
2901 
2902 	/* (un)lock a range of List items. */
2903 	while (li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
2904 	{
2905 	    item_lock(&li->li_tv, deep, lock);
2906 	    li = li->li_next;
2907 	    ++lp->ll_n1;
2908 	}
2909     }
2910     else if (lp->ll_list != NULL)
2911 	/* (un)lock a List item. */
2912 	item_lock(&lp->ll_li->li_tv, deep, lock);
2913     else
2914 	/* (un)lock a Dictionary item. */
2915 	item_lock(&lp->ll_di->di_tv, deep, lock);
2916 
2917     return ret;
2918 }
2919 
2920 /*
2921  * Lock or unlock an item.  "deep" is nr of levels to go.
2922  */
2923     static void
2924 item_lock(typval_T *tv, int deep, int lock)
2925 {
2926     static int	recurse = 0;
2927     list_T	*l;
2928     listitem_T	*li;
2929     dict_T	*d;
2930     hashitem_T	*hi;
2931     int		todo;
2932 
2933     if (recurse >= DICT_MAXNEST)
2934     {
2935 	EMSG(_("E743: variable nested too deep for (un)lock"));
2936 	return;
2937     }
2938     if (deep == 0)
2939 	return;
2940     ++recurse;
2941 
2942     /* lock/unlock the item itself */
2943     if (lock)
2944 	tv->v_lock |= VAR_LOCKED;
2945     else
2946 	tv->v_lock &= ~VAR_LOCKED;
2947 
2948     switch (tv->v_type)
2949     {
2950 	case VAR_UNKNOWN:
2951 	case VAR_NUMBER:
2952 	case VAR_STRING:
2953 	case VAR_FUNC:
2954 	case VAR_PARTIAL:
2955 	case VAR_FLOAT:
2956 	case VAR_SPECIAL:
2957 	case VAR_JOB:
2958 	case VAR_CHANNEL:
2959 	    break;
2960 
2961 	case VAR_LIST:
2962 	    if ((l = tv->vval.v_list) != NULL)
2963 	    {
2964 		if (lock)
2965 		    l->lv_lock |= VAR_LOCKED;
2966 		else
2967 		    l->lv_lock &= ~VAR_LOCKED;
2968 		if (deep < 0 || deep > 1)
2969 		    /* recursive: lock/unlock the items the List contains */
2970 		    for (li = l->lv_first; li != NULL; li = li->li_next)
2971 			item_lock(&li->li_tv, deep - 1, lock);
2972 	    }
2973 	    break;
2974 	case VAR_DICT:
2975 	    if ((d = tv->vval.v_dict) != NULL)
2976 	    {
2977 		if (lock)
2978 		    d->dv_lock |= VAR_LOCKED;
2979 		else
2980 		    d->dv_lock &= ~VAR_LOCKED;
2981 		if (deep < 0 || deep > 1)
2982 		{
2983 		    /* recursive: lock/unlock the items the List contains */
2984 		    todo = (int)d->dv_hashtab.ht_used;
2985 		    for (hi = d->dv_hashtab.ht_array; todo > 0; ++hi)
2986 		    {
2987 			if (!HASHITEM_EMPTY(hi))
2988 			{
2989 			    --todo;
2990 			    item_lock(&HI2DI(hi)->di_tv, deep - 1, lock);
2991 			}
2992 		    }
2993 		}
2994 	    }
2995     }
2996     --recurse;
2997 }
2998 
2999 #if (defined(FEAT_MENU) && defined(FEAT_MULTI_LANG)) || defined(PROTO)
3000 /*
3001  * Delete all "menutrans_" variables.
3002  */
3003     void
3004 del_menutrans_vars(void)
3005 {
3006     hashitem_T	*hi;
3007     int		todo;
3008 
3009     hash_lock(&globvarht);
3010     todo = (int)globvarht.ht_used;
3011     for (hi = globvarht.ht_array; todo > 0 && !got_int; ++hi)
3012     {
3013 	if (!HASHITEM_EMPTY(hi))
3014 	{
3015 	    --todo;
3016 	    if (STRNCMP(HI2DI(hi)->di_key, "menutrans_", 10) == 0)
3017 		delete_var(&globvarht, hi);
3018 	}
3019     }
3020     hash_unlock(&globvarht);
3021 }
3022 #endif
3023 
3024 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
3025 
3026 /*
3027  * Local string buffer for the next two functions to store a variable name
3028  * with its prefix. Allocated in cat_prefix_varname(), freed later in
3029  * get_user_var_name().
3030  */
3031 
3032 static char_u *cat_prefix_varname(int prefix, char_u *name);
3033 
3034 static char_u	*varnamebuf = NULL;
3035 static int	varnamebuflen = 0;
3036 
3037 /*
3038  * Function to concatenate a prefix and a variable name.
3039  */
3040     static char_u *
3041 cat_prefix_varname(int prefix, char_u *name)
3042 {
3043     int		len;
3044 
3045     len = (int)STRLEN(name) + 3;
3046     if (len > varnamebuflen)
3047     {
3048 	vim_free(varnamebuf);
3049 	len += 10;			/* some additional space */
3050 	varnamebuf = alloc(len);
3051 	if (varnamebuf == NULL)
3052 	{
3053 	    varnamebuflen = 0;
3054 	    return NULL;
3055 	}
3056 	varnamebuflen = len;
3057     }
3058     *varnamebuf = prefix;
3059     varnamebuf[1] = ':';
3060     STRCPY(varnamebuf + 2, name);
3061     return varnamebuf;
3062 }
3063 
3064 /*
3065  * Function given to ExpandGeneric() to obtain the list of user defined
3066  * (global/buffer/window/built-in) variable names.
3067  */
3068     char_u *
3069 get_user_var_name(expand_T *xp, int idx)
3070 {
3071     static long_u	gdone;
3072     static long_u	bdone;
3073     static long_u	wdone;
3074 #ifdef FEAT_WINDOWS
3075     static long_u	tdone;
3076 #endif
3077     static int		vidx;
3078     static hashitem_T	*hi;
3079     hashtab_T		*ht;
3080 
3081     if (idx == 0)
3082     {
3083 	gdone = bdone = wdone = vidx = 0;
3084 #ifdef FEAT_WINDOWS
3085 	tdone = 0;
3086 #endif
3087     }
3088 
3089     /* Global variables */
3090     if (gdone < globvarht.ht_used)
3091     {
3092 	if (gdone++ == 0)
3093 	    hi = globvarht.ht_array;
3094 	else
3095 	    ++hi;
3096 	while (HASHITEM_EMPTY(hi))
3097 	    ++hi;
3098 	if (STRNCMP("g:", xp->xp_pattern, 2) == 0)
3099 	    return cat_prefix_varname('g', hi->hi_key);
3100 	return hi->hi_key;
3101     }
3102 
3103     /* b: variables */
3104     ht = &curbuf->b_vars->dv_hashtab;
3105     if (bdone < ht->ht_used)
3106     {
3107 	if (bdone++ == 0)
3108 	    hi = ht->ht_array;
3109 	else
3110 	    ++hi;
3111 	while (HASHITEM_EMPTY(hi))
3112 	    ++hi;
3113 	return cat_prefix_varname('b', hi->hi_key);
3114     }
3115 
3116     /* w: variables */
3117     ht = &curwin->w_vars->dv_hashtab;
3118     if (wdone < ht->ht_used)
3119     {
3120 	if (wdone++ == 0)
3121 	    hi = ht->ht_array;
3122 	else
3123 	    ++hi;
3124 	while (HASHITEM_EMPTY(hi))
3125 	    ++hi;
3126 	return cat_prefix_varname('w', hi->hi_key);
3127     }
3128 
3129 #ifdef FEAT_WINDOWS
3130     /* t: variables */
3131     ht = &curtab->tp_vars->dv_hashtab;
3132     if (tdone < ht->ht_used)
3133     {
3134 	if (tdone++ == 0)
3135 	    hi = ht->ht_array;
3136 	else
3137 	    ++hi;
3138 	while (HASHITEM_EMPTY(hi))
3139 	    ++hi;
3140 	return cat_prefix_varname('t', hi->hi_key);
3141     }
3142 #endif
3143 
3144     /* v: variables */
3145     if (vidx < VV_LEN)
3146 	return cat_prefix_varname('v', (char_u *)vimvars[vidx++].vv_name);
3147 
3148     vim_free(varnamebuf);
3149     varnamebuf = NULL;
3150     varnamebuflen = 0;
3151     return NULL;
3152 }
3153 
3154 #endif /* FEAT_CMDL_COMPL */
3155 
3156 /*
3157  * Return TRUE if "pat" matches "text".
3158  * Does not use 'cpo' and always uses 'magic'.
3159  */
3160     static int
3161 pattern_match(char_u *pat, char_u *text, int ic)
3162 {
3163     int		matches = FALSE;
3164     char_u	*save_cpo;
3165     regmatch_T	regmatch;
3166 
3167     /* avoid 'l' flag in 'cpoptions' */
3168     save_cpo = p_cpo;
3169     p_cpo = (char_u *)"";
3170     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
3171     if (regmatch.regprog != NULL)
3172     {
3173 	regmatch.rm_ic = ic;
3174 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
3175 	vim_regfree(regmatch.regprog);
3176     }
3177     p_cpo = save_cpo;
3178     return matches;
3179 }
3180 
3181 /*
3182  * types for expressions.
3183  */
3184 typedef enum
3185 {
3186     TYPE_UNKNOWN = 0
3187     , TYPE_EQUAL	/* == */
3188     , TYPE_NEQUAL	/* != */
3189     , TYPE_GREATER	/* >  */
3190     , TYPE_GEQUAL	/* >= */
3191     , TYPE_SMALLER	/* <  */
3192     , TYPE_SEQUAL	/* <= */
3193     , TYPE_MATCH	/* =~ */
3194     , TYPE_NOMATCH	/* !~ */
3195 } exptype_T;
3196 
3197 /*
3198  * The "evaluate" argument: When FALSE, the argument is only parsed but not
3199  * executed.  The function may return OK, but the rettv will be of type
3200  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
3201  */
3202 
3203 /*
3204  * Handle zero level expression.
3205  * This calls eval1() and handles error message and nextcmd.
3206  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
3207  * Note: "rettv.v_lock" is not set.
3208  * Return OK or FAIL.
3209  */
3210     int
3211 eval0(
3212     char_u	*arg,
3213     typval_T	*rettv,
3214     char_u	**nextcmd,
3215     int		evaluate)
3216 {
3217     int		ret;
3218     char_u	*p;
3219 
3220     p = skipwhite(arg);
3221     ret = eval1(&p, rettv, evaluate);
3222     if (ret == FAIL || !ends_excmd(*p))
3223     {
3224 	if (ret != FAIL)
3225 	    clear_tv(rettv);
3226 	/*
3227 	 * Report the invalid expression unless the expression evaluation has
3228 	 * been cancelled due to an aborting error, an interrupt, or an
3229 	 * exception.
3230 	 */
3231 	if (!aborting())
3232 	    EMSG2(_(e_invexpr2), arg);
3233 	ret = FAIL;
3234     }
3235     if (nextcmd != NULL)
3236 	*nextcmd = check_nextcmd(p);
3237 
3238     return ret;
3239 }
3240 
3241 /*
3242  * Handle top level expression:
3243  *	expr2 ? expr1 : expr1
3244  *
3245  * "arg" must point to the first non-white of the expression.
3246  * "arg" is advanced to the next non-white after the recognized expression.
3247  *
3248  * Note: "rettv.v_lock" is not set.
3249  *
3250  * Return OK or FAIL.
3251  */
3252     int
3253 eval1(char_u **arg, typval_T *rettv, int evaluate)
3254 {
3255     int		result;
3256     typval_T	var2;
3257 
3258     /*
3259      * Get the first variable.
3260      */
3261     if (eval2(arg, rettv, evaluate) == FAIL)
3262 	return FAIL;
3263 
3264     if ((*arg)[0] == '?')
3265     {
3266 	result = FALSE;
3267 	if (evaluate)
3268 	{
3269 	    int		error = FALSE;
3270 
3271 	    if (get_tv_number_chk(rettv, &error) != 0)
3272 		result = TRUE;
3273 	    clear_tv(rettv);
3274 	    if (error)
3275 		return FAIL;
3276 	}
3277 
3278 	/*
3279 	 * Get the second variable.
3280 	 */
3281 	*arg = skipwhite(*arg + 1);
3282 	if (eval1(arg, rettv, evaluate && result) == FAIL) /* recursive! */
3283 	    return FAIL;
3284 
3285 	/*
3286 	 * Check for the ":".
3287 	 */
3288 	if ((*arg)[0] != ':')
3289 	{
3290 	    EMSG(_("E109: Missing ':' after '?'"));
3291 	    if (evaluate && result)
3292 		clear_tv(rettv);
3293 	    return FAIL;
3294 	}
3295 
3296 	/*
3297 	 * Get the third variable.
3298 	 */
3299 	*arg = skipwhite(*arg + 1);
3300 	if (eval1(arg, &var2, evaluate && !result) == FAIL) /* recursive! */
3301 	{
3302 	    if (evaluate && result)
3303 		clear_tv(rettv);
3304 	    return FAIL;
3305 	}
3306 	if (evaluate && !result)
3307 	    *rettv = var2;
3308     }
3309 
3310     return OK;
3311 }
3312 
3313 /*
3314  * Handle first level expression:
3315  *	expr2 || expr2 || expr2	    logical OR
3316  *
3317  * "arg" must point to the first non-white of the expression.
3318  * "arg" is advanced to the next non-white after the recognized expression.
3319  *
3320  * Return OK or FAIL.
3321  */
3322     static int
3323 eval2(char_u **arg, typval_T *rettv, int evaluate)
3324 {
3325     typval_T	var2;
3326     long	result;
3327     int		first;
3328     int		error = FALSE;
3329 
3330     /*
3331      * Get the first variable.
3332      */
3333     if (eval3(arg, rettv, evaluate) == FAIL)
3334 	return FAIL;
3335 
3336     /*
3337      * Repeat until there is no following "||".
3338      */
3339     first = TRUE;
3340     result = FALSE;
3341     while ((*arg)[0] == '|' && (*arg)[1] == '|')
3342     {
3343 	if (evaluate && first)
3344 	{
3345 	    if (get_tv_number_chk(rettv, &error) != 0)
3346 		result = TRUE;
3347 	    clear_tv(rettv);
3348 	    if (error)
3349 		return FAIL;
3350 	    first = FALSE;
3351 	}
3352 
3353 	/*
3354 	 * Get the second variable.
3355 	 */
3356 	*arg = skipwhite(*arg + 2);
3357 	if (eval3(arg, &var2, evaluate && !result) == FAIL)
3358 	    return FAIL;
3359 
3360 	/*
3361 	 * Compute the result.
3362 	 */
3363 	if (evaluate && !result)
3364 	{
3365 	    if (get_tv_number_chk(&var2, &error) != 0)
3366 		result = TRUE;
3367 	    clear_tv(&var2);
3368 	    if (error)
3369 		return FAIL;
3370 	}
3371 	if (evaluate)
3372 	{
3373 	    rettv->v_type = VAR_NUMBER;
3374 	    rettv->vval.v_number = result;
3375 	}
3376     }
3377 
3378     return OK;
3379 }
3380 
3381 /*
3382  * Handle second level expression:
3383  *	expr3 && expr3 && expr3	    logical AND
3384  *
3385  * "arg" must point to the first non-white of the expression.
3386  * "arg" is advanced to the next non-white after the recognized expression.
3387  *
3388  * Return OK or FAIL.
3389  */
3390     static int
3391 eval3(char_u **arg, typval_T *rettv, int evaluate)
3392 {
3393     typval_T	var2;
3394     long	result;
3395     int		first;
3396     int		error = FALSE;
3397 
3398     /*
3399      * Get the first variable.
3400      */
3401     if (eval4(arg, rettv, evaluate) == FAIL)
3402 	return FAIL;
3403 
3404     /*
3405      * Repeat until there is no following "&&".
3406      */
3407     first = TRUE;
3408     result = TRUE;
3409     while ((*arg)[0] == '&' && (*arg)[1] == '&')
3410     {
3411 	if (evaluate && first)
3412 	{
3413 	    if (get_tv_number_chk(rettv, &error) == 0)
3414 		result = FALSE;
3415 	    clear_tv(rettv);
3416 	    if (error)
3417 		return FAIL;
3418 	    first = FALSE;
3419 	}
3420 
3421 	/*
3422 	 * Get the second variable.
3423 	 */
3424 	*arg = skipwhite(*arg + 2);
3425 	if (eval4(arg, &var2, evaluate && result) == FAIL)
3426 	    return FAIL;
3427 
3428 	/*
3429 	 * Compute the result.
3430 	 */
3431 	if (evaluate && result)
3432 	{
3433 	    if (get_tv_number_chk(&var2, &error) == 0)
3434 		result = FALSE;
3435 	    clear_tv(&var2);
3436 	    if (error)
3437 		return FAIL;
3438 	}
3439 	if (evaluate)
3440 	{
3441 	    rettv->v_type = VAR_NUMBER;
3442 	    rettv->vval.v_number = result;
3443 	}
3444     }
3445 
3446     return OK;
3447 }
3448 
3449 /*
3450  * Handle third level expression:
3451  *	var1 == var2
3452  *	var1 =~ var2
3453  *	var1 != var2
3454  *	var1 !~ var2
3455  *	var1 > var2
3456  *	var1 >= var2
3457  *	var1 < var2
3458  *	var1 <= var2
3459  *	var1 is var2
3460  *	var1 isnot var2
3461  *
3462  * "arg" must point to the first non-white of the expression.
3463  * "arg" is advanced to the next non-white after the recognized expression.
3464  *
3465  * Return OK or FAIL.
3466  */
3467     static int
3468 eval4(char_u **arg, typval_T *rettv, int evaluate)
3469 {
3470     typval_T	var2;
3471     char_u	*p;
3472     int		i;
3473     exptype_T	type = TYPE_UNKNOWN;
3474     int		type_is = FALSE;    /* TRUE for "is" and "isnot" */
3475     int		len = 2;
3476     varnumber_T	n1, n2;
3477     char_u	*s1, *s2;
3478     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3479     int		ic;
3480 
3481     /*
3482      * Get the first variable.
3483      */
3484     if (eval5(arg, rettv, evaluate) == FAIL)
3485 	return FAIL;
3486 
3487     p = *arg;
3488     switch (p[0])
3489     {
3490 	case '=':   if (p[1] == '=')
3491 			type = TYPE_EQUAL;
3492 		    else if (p[1] == '~')
3493 			type = TYPE_MATCH;
3494 		    break;
3495 	case '!':   if (p[1] == '=')
3496 			type = TYPE_NEQUAL;
3497 		    else if (p[1] == '~')
3498 			type = TYPE_NOMATCH;
3499 		    break;
3500 	case '>':   if (p[1] != '=')
3501 		    {
3502 			type = TYPE_GREATER;
3503 			len = 1;
3504 		    }
3505 		    else
3506 			type = TYPE_GEQUAL;
3507 		    break;
3508 	case '<':   if (p[1] != '=')
3509 		    {
3510 			type = TYPE_SMALLER;
3511 			len = 1;
3512 		    }
3513 		    else
3514 			type = TYPE_SEQUAL;
3515 		    break;
3516 	case 'i':   if (p[1] == 's')
3517 		    {
3518 			if (p[2] == 'n' && p[3] == 'o' && p[4] == 't')
3519 			    len = 5;
3520 			i = p[len];
3521 			if (!isalnum(i) && i != '_')
3522 			{
3523 			    type = len == 2 ? TYPE_EQUAL : TYPE_NEQUAL;
3524 			    type_is = TRUE;
3525 			}
3526 		    }
3527 		    break;
3528     }
3529 
3530     /*
3531      * If there is a comparative operator, use it.
3532      */
3533     if (type != TYPE_UNKNOWN)
3534     {
3535 	/* extra question mark appended: ignore case */
3536 	if (p[len] == '?')
3537 	{
3538 	    ic = TRUE;
3539 	    ++len;
3540 	}
3541 	/* extra '#' appended: match case */
3542 	else if (p[len] == '#')
3543 	{
3544 	    ic = FALSE;
3545 	    ++len;
3546 	}
3547 	/* nothing appended: use 'ignorecase' */
3548 	else
3549 	    ic = p_ic;
3550 
3551 	/*
3552 	 * Get the second variable.
3553 	 */
3554 	*arg = skipwhite(p + len);
3555 	if (eval5(arg, &var2, evaluate) == FAIL)
3556 	{
3557 	    clear_tv(rettv);
3558 	    return FAIL;
3559 	}
3560 
3561 	if (evaluate)
3562 	{
3563 	    if (type_is && rettv->v_type != var2.v_type)
3564 	    {
3565 		/* For "is" a different type always means FALSE, for "notis"
3566 		 * it means TRUE. */
3567 		n1 = (type == TYPE_NEQUAL);
3568 	    }
3569 	    else if (rettv->v_type == VAR_LIST || var2.v_type == VAR_LIST)
3570 	    {
3571 		if (type_is)
3572 		{
3573 		    n1 = (rettv->v_type == var2.v_type
3574 				   && rettv->vval.v_list == var2.vval.v_list);
3575 		    if (type == TYPE_NEQUAL)
3576 			n1 = !n1;
3577 		}
3578 		else if (rettv->v_type != var2.v_type
3579 			|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
3580 		{
3581 		    if (rettv->v_type != var2.v_type)
3582 			EMSG(_("E691: Can only compare List with List"));
3583 		    else
3584 			EMSG(_("E692: Invalid operation for List"));
3585 		    clear_tv(rettv);
3586 		    clear_tv(&var2);
3587 		    return FAIL;
3588 		}
3589 		else
3590 		{
3591 		    /* Compare two Lists for being equal or unequal. */
3592 		    n1 = list_equal(rettv->vval.v_list, var2.vval.v_list,
3593 								   ic, FALSE);
3594 		    if (type == TYPE_NEQUAL)
3595 			n1 = !n1;
3596 		}
3597 	    }
3598 
3599 	    else if (rettv->v_type == VAR_DICT || var2.v_type == VAR_DICT)
3600 	    {
3601 		if (type_is)
3602 		{
3603 		    n1 = (rettv->v_type == var2.v_type
3604 				   && rettv->vval.v_dict == var2.vval.v_dict);
3605 		    if (type == TYPE_NEQUAL)
3606 			n1 = !n1;
3607 		}
3608 		else if (rettv->v_type != var2.v_type
3609 			|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
3610 		{
3611 		    if (rettv->v_type != var2.v_type)
3612 			EMSG(_("E735: Can only compare Dictionary with Dictionary"));
3613 		    else
3614 			EMSG(_("E736: Invalid operation for Dictionary"));
3615 		    clear_tv(rettv);
3616 		    clear_tv(&var2);
3617 		    return FAIL;
3618 		}
3619 		else
3620 		{
3621 		    /* Compare two Dictionaries for being equal or unequal. */
3622 		    n1 = dict_equal(rettv->vval.v_dict, var2.vval.v_dict,
3623 								   ic, FALSE);
3624 		    if (type == TYPE_NEQUAL)
3625 			n1 = !n1;
3626 		}
3627 	    }
3628 
3629 	    else if (rettv->v_type == VAR_FUNC || var2.v_type == VAR_FUNC
3630 		|| rettv->v_type == VAR_PARTIAL || var2.v_type == VAR_PARTIAL)
3631 	    {
3632 		if (type != TYPE_EQUAL && type != TYPE_NEQUAL)
3633 		{
3634 		    EMSG(_("E694: Invalid operation for Funcrefs"));
3635 		    clear_tv(rettv);
3636 		    clear_tv(&var2);
3637 		    return FAIL;
3638 		}
3639 		if ((rettv->v_type == VAR_PARTIAL
3640 					     && rettv->vval.v_partial == NULL)
3641 			|| (var2.v_type == VAR_PARTIAL
3642 					      && var2.vval.v_partial == NULL))
3643 		    /* when a partial is NULL assume not equal */
3644 		    n1 = FALSE;
3645 		else if (type_is)
3646 		{
3647 		    if (rettv->v_type == VAR_FUNC && var2.v_type == VAR_FUNC)
3648 			/* strings are considered the same if their value is
3649 			 * the same */
3650 			n1 = tv_equal(rettv, &var2, ic, FALSE);
3651 		    else if (rettv->v_type == VAR_PARTIAL
3652 						&& var2.v_type == VAR_PARTIAL)
3653 			n1 = (rettv->vval.v_partial == var2.vval.v_partial);
3654 		    else
3655 			n1 = FALSE;
3656 		}
3657 		else
3658 		    n1 = tv_equal(rettv, &var2, ic, FALSE);
3659 		if (type == TYPE_NEQUAL)
3660 		    n1 = !n1;
3661 	    }
3662 
3663 #ifdef FEAT_FLOAT
3664 	    /*
3665 	     * If one of the two variables is a float, compare as a float.
3666 	     * When using "=~" or "!~", always compare as string.
3667 	     */
3668 	    else if ((rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3669 		    && type != TYPE_MATCH && type != TYPE_NOMATCH)
3670 	    {
3671 		float_T f1, f2;
3672 
3673 		if (rettv->v_type == VAR_FLOAT)
3674 		    f1 = rettv->vval.v_float;
3675 		else
3676 		    f1 = get_tv_number(rettv);
3677 		if (var2.v_type == VAR_FLOAT)
3678 		    f2 = var2.vval.v_float;
3679 		else
3680 		    f2 = get_tv_number(&var2);
3681 		n1 = FALSE;
3682 		switch (type)
3683 		{
3684 		    case TYPE_EQUAL:    n1 = (f1 == f2); break;
3685 		    case TYPE_NEQUAL:   n1 = (f1 != f2); break;
3686 		    case TYPE_GREATER:  n1 = (f1 > f2); break;
3687 		    case TYPE_GEQUAL:   n1 = (f1 >= f2); break;
3688 		    case TYPE_SMALLER:  n1 = (f1 < f2); break;
3689 		    case TYPE_SEQUAL:   n1 = (f1 <= f2); break;
3690 		    case TYPE_UNKNOWN:
3691 		    case TYPE_MATCH:
3692 		    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
3693 		}
3694 	    }
3695 #endif
3696 
3697 	    /*
3698 	     * If one of the two variables is a number, compare as a number.
3699 	     * When using "=~" or "!~", always compare as string.
3700 	     */
3701 	    else if ((rettv->v_type == VAR_NUMBER || var2.v_type == VAR_NUMBER)
3702 		    && type != TYPE_MATCH && type != TYPE_NOMATCH)
3703 	    {
3704 		n1 = get_tv_number(rettv);
3705 		n2 = get_tv_number(&var2);
3706 		switch (type)
3707 		{
3708 		    case TYPE_EQUAL:    n1 = (n1 == n2); break;
3709 		    case TYPE_NEQUAL:   n1 = (n1 != n2); break;
3710 		    case TYPE_GREATER:  n1 = (n1 > n2); break;
3711 		    case TYPE_GEQUAL:   n1 = (n1 >= n2); break;
3712 		    case TYPE_SMALLER:  n1 = (n1 < n2); break;
3713 		    case TYPE_SEQUAL:   n1 = (n1 <= n2); break;
3714 		    case TYPE_UNKNOWN:
3715 		    case TYPE_MATCH:
3716 		    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
3717 		}
3718 	    }
3719 	    else
3720 	    {
3721 		s1 = get_tv_string_buf(rettv, buf1);
3722 		s2 = get_tv_string_buf(&var2, buf2);
3723 		if (type != TYPE_MATCH && type != TYPE_NOMATCH)
3724 		    i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
3725 		else
3726 		    i = 0;
3727 		n1 = FALSE;
3728 		switch (type)
3729 		{
3730 		    case TYPE_EQUAL:    n1 = (i == 0); break;
3731 		    case TYPE_NEQUAL:   n1 = (i != 0); break;
3732 		    case TYPE_GREATER:  n1 = (i > 0); break;
3733 		    case TYPE_GEQUAL:   n1 = (i >= 0); break;
3734 		    case TYPE_SMALLER:  n1 = (i < 0); break;
3735 		    case TYPE_SEQUAL:   n1 = (i <= 0); break;
3736 
3737 		    case TYPE_MATCH:
3738 		    case TYPE_NOMATCH:
3739 			    n1 = pattern_match(s2, s1, ic);
3740 			    if (type == TYPE_NOMATCH)
3741 				n1 = !n1;
3742 			    break;
3743 
3744 		    case TYPE_UNKNOWN:  break;  /* avoid gcc warning */
3745 		}
3746 	    }
3747 	    clear_tv(rettv);
3748 	    clear_tv(&var2);
3749 	    rettv->v_type = VAR_NUMBER;
3750 	    rettv->vval.v_number = n1;
3751 	}
3752     }
3753 
3754     return OK;
3755 }
3756 
3757 /*
3758  * Handle fourth level expression:
3759  *	+	number addition
3760  *	-	number subtraction
3761  *	.	string concatenation
3762  *
3763  * "arg" must point to the first non-white of the expression.
3764  * "arg" is advanced to the next non-white after the recognized expression.
3765  *
3766  * Return OK or FAIL.
3767  */
3768     static int
3769 eval5(char_u **arg, typval_T *rettv, int evaluate)
3770 {
3771     typval_T	var2;
3772     typval_T	var3;
3773     int		op;
3774     varnumber_T	n1, n2;
3775 #ifdef FEAT_FLOAT
3776     float_T	f1 = 0, f2 = 0;
3777 #endif
3778     char_u	*s1, *s2;
3779     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3780     char_u	*p;
3781 
3782     /*
3783      * Get the first variable.
3784      */
3785     if (eval6(arg, rettv, evaluate, FALSE) == FAIL)
3786 	return FAIL;
3787 
3788     /*
3789      * Repeat computing, until no '+', '-' or '.' is following.
3790      */
3791     for (;;)
3792     {
3793 	op = **arg;
3794 	if (op != '+' && op != '-' && op != '.')
3795 	    break;
3796 
3797 	if ((op != '+' || rettv->v_type != VAR_LIST)
3798 #ifdef FEAT_FLOAT
3799 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
3800 #endif
3801 		)
3802 	{
3803 	    /* For "list + ...", an illegal use of the first operand as
3804 	     * a number cannot be determined before evaluating the 2nd
3805 	     * operand: if this is also a list, all is ok.
3806 	     * For "something . ...", "something - ..." or "non-list + ...",
3807 	     * we know that the first operand needs to be a string or number
3808 	     * without evaluating the 2nd operand.  So check before to avoid
3809 	     * side effects after an error. */
3810 	    if (evaluate && get_tv_string_chk(rettv) == NULL)
3811 	    {
3812 		clear_tv(rettv);
3813 		return FAIL;
3814 	    }
3815 	}
3816 
3817 	/*
3818 	 * Get the second variable.
3819 	 */
3820 	*arg = skipwhite(*arg + 1);
3821 	if (eval6(arg, &var2, evaluate, op == '.') == FAIL)
3822 	{
3823 	    clear_tv(rettv);
3824 	    return FAIL;
3825 	}
3826 
3827 	if (evaluate)
3828 	{
3829 	    /*
3830 	     * Compute the result.
3831 	     */
3832 	    if (op == '.')
3833 	    {
3834 		s1 = get_tv_string_buf(rettv, buf1);	/* already checked */
3835 		s2 = get_tv_string_buf_chk(&var2, buf2);
3836 		if (s2 == NULL)		/* type error ? */
3837 		{
3838 		    clear_tv(rettv);
3839 		    clear_tv(&var2);
3840 		    return FAIL;
3841 		}
3842 		p = concat_str(s1, s2);
3843 		clear_tv(rettv);
3844 		rettv->v_type = VAR_STRING;
3845 		rettv->vval.v_string = p;
3846 	    }
3847 	    else if (op == '+' && rettv->v_type == VAR_LIST
3848 						   && var2.v_type == VAR_LIST)
3849 	    {
3850 		/* concatenate Lists */
3851 		if (list_concat(rettv->vval.v_list, var2.vval.v_list,
3852 							       &var3) == FAIL)
3853 		{
3854 		    clear_tv(rettv);
3855 		    clear_tv(&var2);
3856 		    return FAIL;
3857 		}
3858 		clear_tv(rettv);
3859 		*rettv = var3;
3860 	    }
3861 	    else
3862 	    {
3863 		int	    error = FALSE;
3864 
3865 #ifdef FEAT_FLOAT
3866 		if (rettv->v_type == VAR_FLOAT)
3867 		{
3868 		    f1 = rettv->vval.v_float;
3869 		    n1 = 0;
3870 		}
3871 		else
3872 #endif
3873 		{
3874 		    n1 = get_tv_number_chk(rettv, &error);
3875 		    if (error)
3876 		    {
3877 			/* This can only happen for "list + non-list".  For
3878 			 * "non-list + ..." or "something - ...", we returned
3879 			 * before evaluating the 2nd operand. */
3880 			clear_tv(rettv);
3881 			return FAIL;
3882 		    }
3883 #ifdef FEAT_FLOAT
3884 		    if (var2.v_type == VAR_FLOAT)
3885 			f1 = n1;
3886 #endif
3887 		}
3888 #ifdef FEAT_FLOAT
3889 		if (var2.v_type == VAR_FLOAT)
3890 		{
3891 		    f2 = var2.vval.v_float;
3892 		    n2 = 0;
3893 		}
3894 		else
3895 #endif
3896 		{
3897 		    n2 = get_tv_number_chk(&var2, &error);
3898 		    if (error)
3899 		    {
3900 			clear_tv(rettv);
3901 			clear_tv(&var2);
3902 			return FAIL;
3903 		    }
3904 #ifdef FEAT_FLOAT
3905 		    if (rettv->v_type == VAR_FLOAT)
3906 			f2 = n2;
3907 #endif
3908 		}
3909 		clear_tv(rettv);
3910 
3911 #ifdef FEAT_FLOAT
3912 		/* If there is a float on either side the result is a float. */
3913 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3914 		{
3915 		    if (op == '+')
3916 			f1 = f1 + f2;
3917 		    else
3918 			f1 = f1 - f2;
3919 		    rettv->v_type = VAR_FLOAT;
3920 		    rettv->vval.v_float = f1;
3921 		}
3922 		else
3923 #endif
3924 		{
3925 		    if (op == '+')
3926 			n1 = n1 + n2;
3927 		    else
3928 			n1 = n1 - n2;
3929 		    rettv->v_type = VAR_NUMBER;
3930 		    rettv->vval.v_number = n1;
3931 		}
3932 	    }
3933 	    clear_tv(&var2);
3934 	}
3935     }
3936     return OK;
3937 }
3938 
3939 /*
3940  * Handle fifth level expression:
3941  *	*	number multiplication
3942  *	/	number division
3943  *	%	number modulo
3944  *
3945  * "arg" must point to the first non-white of the expression.
3946  * "arg" is advanced to the next non-white after the recognized expression.
3947  *
3948  * Return OK or FAIL.
3949  */
3950     static int
3951 eval6(
3952     char_u	**arg,
3953     typval_T	*rettv,
3954     int		evaluate,
3955     int		want_string)  /* after "." operator */
3956 {
3957     typval_T	var2;
3958     int		op;
3959     varnumber_T	n1, n2;
3960 #ifdef FEAT_FLOAT
3961     int		use_float = FALSE;
3962     float_T	f1 = 0, f2;
3963 #endif
3964     int		error = FALSE;
3965 
3966     /*
3967      * Get the first variable.
3968      */
3969     if (eval7(arg, rettv, evaluate, want_string) == FAIL)
3970 	return FAIL;
3971 
3972     /*
3973      * Repeat computing, until no '*', '/' or '%' is following.
3974      */
3975     for (;;)
3976     {
3977 	op = **arg;
3978 	if (op != '*' && op != '/' && op != '%')
3979 	    break;
3980 
3981 	if (evaluate)
3982 	{
3983 #ifdef FEAT_FLOAT
3984 	    if (rettv->v_type == VAR_FLOAT)
3985 	    {
3986 		f1 = rettv->vval.v_float;
3987 		use_float = TRUE;
3988 		n1 = 0;
3989 	    }
3990 	    else
3991 #endif
3992 		n1 = get_tv_number_chk(rettv, &error);
3993 	    clear_tv(rettv);
3994 	    if (error)
3995 		return FAIL;
3996 	}
3997 	else
3998 	    n1 = 0;
3999 
4000 	/*
4001 	 * Get the second variable.
4002 	 */
4003 	*arg = skipwhite(*arg + 1);
4004 	if (eval7(arg, &var2, evaluate, FALSE) == FAIL)
4005 	    return FAIL;
4006 
4007 	if (evaluate)
4008 	{
4009 #ifdef FEAT_FLOAT
4010 	    if (var2.v_type == VAR_FLOAT)
4011 	    {
4012 		if (!use_float)
4013 		{
4014 		    f1 = n1;
4015 		    use_float = TRUE;
4016 		}
4017 		f2 = var2.vval.v_float;
4018 		n2 = 0;
4019 	    }
4020 	    else
4021 #endif
4022 	    {
4023 		n2 = get_tv_number_chk(&var2, &error);
4024 		clear_tv(&var2);
4025 		if (error)
4026 		    return FAIL;
4027 #ifdef FEAT_FLOAT
4028 		if (use_float)
4029 		    f2 = n2;
4030 #endif
4031 	    }
4032 
4033 	    /*
4034 	     * Compute the result.
4035 	     * When either side is a float the result is a float.
4036 	     */
4037 #ifdef FEAT_FLOAT
4038 	    if (use_float)
4039 	    {
4040 		if (op == '*')
4041 		    f1 = f1 * f2;
4042 		else if (op == '/')
4043 		{
4044 # ifdef VMS
4045 		    /* VMS crashes on divide by zero, work around it */
4046 		    if (f2 == 0.0)
4047 		    {
4048 			if (f1 == 0)
4049 			    f1 = -1 * __F_FLT_MAX - 1L;   /* similar to NaN */
4050 			else if (f1 < 0)
4051 			    f1 = -1 * __F_FLT_MAX;
4052 			else
4053 			    f1 = __F_FLT_MAX;
4054 		    }
4055 		    else
4056 			f1 = f1 / f2;
4057 # else
4058 		    /* We rely on the floating point library to handle divide
4059 		     * by zero to result in "inf" and not a crash. */
4060 		    f1 = f1 / f2;
4061 # endif
4062 		}
4063 		else
4064 		{
4065 		    EMSG(_("E804: Cannot use '%' with Float"));
4066 		    return FAIL;
4067 		}
4068 		rettv->v_type = VAR_FLOAT;
4069 		rettv->vval.v_float = f1;
4070 	    }
4071 	    else
4072 #endif
4073 	    {
4074 		if (op == '*')
4075 		    n1 = n1 * n2;
4076 		else if (op == '/')
4077 		{
4078 		    if (n2 == 0)	/* give an error message? */
4079 		    {
4080 			if (n1 == 0)
4081 			    n1 = VARNUM_MIN; /* similar to NaN */
4082 			else if (n1 < 0)
4083 			    n1 = -VARNUM_MAX;
4084 			else
4085 			    n1 = VARNUM_MAX;
4086 		    }
4087 		    else
4088 			n1 = n1 / n2;
4089 		}
4090 		else
4091 		{
4092 		    if (n2 == 0)	/* give an error message? */
4093 			n1 = 0;
4094 		    else
4095 			n1 = n1 % n2;
4096 		}
4097 		rettv->v_type = VAR_NUMBER;
4098 		rettv->vval.v_number = n1;
4099 	    }
4100 	}
4101     }
4102 
4103     return OK;
4104 }
4105 
4106 /*
4107  * Handle sixth level expression:
4108  *  number		number constant
4109  *  "string"		string constant
4110  *  'string'		literal string constant
4111  *  &option-name	option value
4112  *  @r			register contents
4113  *  identifier		variable value
4114  *  function()		function call
4115  *  $VAR		environment variable
4116  *  (expression)	nested expression
4117  *  [expr, expr]	List
4118  *  {key: val, key: val}  Dictionary
4119  *
4120  *  Also handle:
4121  *  ! in front		logical NOT
4122  *  - in front		unary minus
4123  *  + in front		unary plus (ignored)
4124  *  trailing []		subscript in String or List
4125  *  trailing .name	entry in Dictionary
4126  *
4127  * "arg" must point to the first non-white of the expression.
4128  * "arg" is advanced to the next non-white after the recognized expression.
4129  *
4130  * Return OK or FAIL.
4131  */
4132     static int
4133 eval7(
4134     char_u	**arg,
4135     typval_T	*rettv,
4136     int		evaluate,
4137     int		want_string UNUSED)	/* after "." operator */
4138 {
4139     varnumber_T	n;
4140     int		len;
4141     char_u	*s;
4142     char_u	*start_leader, *end_leader;
4143     int		ret = OK;
4144     char_u	*alias;
4145 
4146     /*
4147      * Initialise variable so that clear_tv() can't mistake this for a
4148      * string and free a string that isn't there.
4149      */
4150     rettv->v_type = VAR_UNKNOWN;
4151 
4152     /*
4153      * Skip '!', '-' and '+' characters.  They are handled later.
4154      */
4155     start_leader = *arg;
4156     while (**arg == '!' || **arg == '-' || **arg == '+')
4157 	*arg = skipwhite(*arg + 1);
4158     end_leader = *arg;
4159 
4160     switch (**arg)
4161     {
4162     /*
4163      * Number constant.
4164      */
4165     case '0':
4166     case '1':
4167     case '2':
4168     case '3':
4169     case '4':
4170     case '5':
4171     case '6':
4172     case '7':
4173     case '8':
4174     case '9':
4175 	{
4176 #ifdef FEAT_FLOAT
4177 		char_u *p = skipdigits(*arg + 1);
4178 		int    get_float = FALSE;
4179 
4180 		/* We accept a float when the format matches
4181 		 * "[0-9]\+\.[0-9]\+\([eE][+-]\?[0-9]\+\)\?".  This is very
4182 		 * strict to avoid backwards compatibility problems.
4183 		 * Don't look for a float after the "." operator, so that
4184 		 * ":let vers = 1.2.3" doesn't fail. */
4185 		if (!want_string && p[0] == '.' && vim_isdigit(p[1]))
4186 		{
4187 		    get_float = TRUE;
4188 		    p = skipdigits(p + 2);
4189 		    if (*p == 'e' || *p == 'E')
4190 		    {
4191 			++p;
4192 			if (*p == '-' || *p == '+')
4193 			    ++p;
4194 			if (!vim_isdigit(*p))
4195 			    get_float = FALSE;
4196 			else
4197 			    p = skipdigits(p + 1);
4198 		    }
4199 		    if (ASCII_ISALPHA(*p) || *p == '.')
4200 			get_float = FALSE;
4201 		}
4202 		if (get_float)
4203 		{
4204 		    float_T	f;
4205 
4206 		    *arg += string2float(*arg, &f);
4207 		    if (evaluate)
4208 		    {
4209 			rettv->v_type = VAR_FLOAT;
4210 			rettv->vval.v_float = f;
4211 		    }
4212 		}
4213 		else
4214 #endif
4215 		{
4216 		    vim_str2nr(*arg, NULL, &len, STR2NR_ALL, &n, NULL, 0);
4217 		    *arg += len;
4218 		    if (evaluate)
4219 		    {
4220 			rettv->v_type = VAR_NUMBER;
4221 			rettv->vval.v_number = n;
4222 		    }
4223 		}
4224 		break;
4225 	}
4226 
4227     /*
4228      * String constant: "string".
4229      */
4230     case '"':	ret = get_string_tv(arg, rettv, evaluate);
4231 		break;
4232 
4233     /*
4234      * Literal string constant: 'str''ing'.
4235      */
4236     case '\'':	ret = get_lit_string_tv(arg, rettv, evaluate);
4237 		break;
4238 
4239     /*
4240      * List: [expr, expr]
4241      */
4242     case '[':	ret = get_list_tv(arg, rettv, evaluate);
4243 		break;
4244 
4245     /*
4246      * Lambda: {arg, arg -> expr}
4247      * Dictionary: {key: val, key: val}
4248      */
4249     case '{':	ret = get_lambda_tv(arg, rettv, evaluate);
4250 		if (ret == NOTDONE)
4251 		    ret = get_dict_tv(arg, rettv, evaluate);
4252 		break;
4253 
4254     /*
4255      * Option value: &name
4256      */
4257     case '&':	ret = get_option_tv(arg, rettv, evaluate);
4258 		break;
4259 
4260     /*
4261      * Environment variable: $VAR.
4262      */
4263     case '$':	ret = get_env_tv(arg, rettv, evaluate);
4264 		break;
4265 
4266     /*
4267      * Register contents: @r.
4268      */
4269     case '@':	++*arg;
4270 		if (evaluate)
4271 		{
4272 		    rettv->v_type = VAR_STRING;
4273 		    rettv->vval.v_string = get_reg_contents(**arg,
4274 							    GREG_EXPR_SRC);
4275 		}
4276 		if (**arg != NUL)
4277 		    ++*arg;
4278 		break;
4279 
4280     /*
4281      * nested expression: (expression).
4282      */
4283     case '(':	*arg = skipwhite(*arg + 1);
4284 		ret = eval1(arg, rettv, evaluate);	/* recursive! */
4285 		if (**arg == ')')
4286 		    ++*arg;
4287 		else if (ret == OK)
4288 		{
4289 		    EMSG(_("E110: Missing ')'"));
4290 		    clear_tv(rettv);
4291 		    ret = FAIL;
4292 		}
4293 		break;
4294 
4295     default:	ret = NOTDONE;
4296 		break;
4297     }
4298 
4299     if (ret == NOTDONE)
4300     {
4301 	/*
4302 	 * Must be a variable or function name.
4303 	 * Can also be a curly-braces kind of name: {expr}.
4304 	 */
4305 	s = *arg;
4306 	len = get_name_len(arg, &alias, evaluate, TRUE);
4307 	if (alias != NULL)
4308 	    s = alias;
4309 
4310 	if (len <= 0)
4311 	    ret = FAIL;
4312 	else
4313 	{
4314 	    if (**arg == '(')		/* recursive! */
4315 	    {
4316 		partial_T *partial;
4317 
4318 		if (!evaluate)
4319 		    check_vars(s, len);
4320 
4321 		/* If "s" is the name of a variable of type VAR_FUNC
4322 		 * use its contents. */
4323 		s = deref_func_name(s, &len, &partial, !evaluate);
4324 
4325 		/* Need to make a copy, in case evaluating the arguments makes
4326 		 * the name invalid. */
4327 		s = vim_strsave(s);
4328 		if (s == NULL)
4329 		    ret = FAIL;
4330 		else
4331 		    /* Invoke the function. */
4332 		    ret = get_func_tv(s, len, rettv, arg,
4333 			      curwin->w_cursor.lnum, curwin->w_cursor.lnum,
4334 			      &len, evaluate, partial, NULL);
4335 		vim_free(s);
4336 
4337 		/* If evaluate is FALSE rettv->v_type was not set in
4338 		 * get_func_tv, but it's needed in handle_subscript() to parse
4339 		 * what follows. So set it here. */
4340 		if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
4341 		{
4342 		    rettv->vval.v_string = NULL;
4343 		    rettv->v_type = VAR_FUNC;
4344 		}
4345 
4346 		/* Stop the expression evaluation when immediately
4347 		 * aborting on error, or when an interrupt occurred or
4348 		 * an exception was thrown but not caught. */
4349 		if (aborting())
4350 		{
4351 		    if (ret == OK)
4352 			clear_tv(rettv);
4353 		    ret = FAIL;
4354 		}
4355 	    }
4356 	    else if (evaluate)
4357 		ret = get_var_tv(s, len, rettv, NULL, TRUE, FALSE);
4358 	    else
4359 	    {
4360 		check_vars(s, len);
4361 		ret = OK;
4362 	    }
4363 	}
4364 	vim_free(alias);
4365     }
4366 
4367     *arg = skipwhite(*arg);
4368 
4369     /* Handle following '[', '(' and '.' for expr[expr], expr.name,
4370      * expr(expr). */
4371     if (ret == OK)
4372 	ret = handle_subscript(arg, rettv, evaluate, TRUE);
4373 
4374     /*
4375      * Apply logical NOT and unary '-', from right to left, ignore '+'.
4376      */
4377     if (ret == OK && evaluate && end_leader > start_leader)
4378     {
4379 	int	    error = FALSE;
4380 	varnumber_T val = 0;
4381 #ifdef FEAT_FLOAT
4382 	float_T	    f = 0.0;
4383 
4384 	if (rettv->v_type == VAR_FLOAT)
4385 	    f = rettv->vval.v_float;
4386 	else
4387 #endif
4388 	    val = get_tv_number_chk(rettv, &error);
4389 	if (error)
4390 	{
4391 	    clear_tv(rettv);
4392 	    ret = FAIL;
4393 	}
4394 	else
4395 	{
4396 	    while (end_leader > start_leader)
4397 	    {
4398 		--end_leader;
4399 		if (*end_leader == '!')
4400 		{
4401 #ifdef FEAT_FLOAT
4402 		    if (rettv->v_type == VAR_FLOAT)
4403 			f = !f;
4404 		    else
4405 #endif
4406 			val = !val;
4407 		}
4408 		else if (*end_leader == '-')
4409 		{
4410 #ifdef FEAT_FLOAT
4411 		    if (rettv->v_type == VAR_FLOAT)
4412 			f = -f;
4413 		    else
4414 #endif
4415 			val = -val;
4416 		}
4417 	    }
4418 #ifdef FEAT_FLOAT
4419 	    if (rettv->v_type == VAR_FLOAT)
4420 	    {
4421 		clear_tv(rettv);
4422 		rettv->vval.v_float = f;
4423 	    }
4424 	    else
4425 #endif
4426 	    {
4427 		clear_tv(rettv);
4428 		rettv->v_type = VAR_NUMBER;
4429 		rettv->vval.v_number = val;
4430 	    }
4431 	}
4432     }
4433 
4434     return ret;
4435 }
4436 
4437 /*
4438  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
4439  * "*arg" points to the '[' or '.'.
4440  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
4441  */
4442     static int
4443 eval_index(
4444     char_u	**arg,
4445     typval_T	*rettv,
4446     int		evaluate,
4447     int		verbose)	/* give error messages */
4448 {
4449     int		empty1 = FALSE, empty2 = FALSE;
4450     typval_T	var1, var2;
4451     long	n1, n2 = 0;
4452     long	len = -1;
4453     int		range = FALSE;
4454     char_u	*s;
4455     char_u	*key = NULL;
4456 
4457     switch (rettv->v_type)
4458     {
4459 	case VAR_FUNC:
4460 	case VAR_PARTIAL:
4461 	    if (verbose)
4462 		EMSG(_("E695: Cannot index a Funcref"));
4463 	    return FAIL;
4464 	case VAR_FLOAT:
4465 #ifdef FEAT_FLOAT
4466 	    if (verbose)
4467 		EMSG(_(e_float_as_string));
4468 	    return FAIL;
4469 #endif
4470 	case VAR_SPECIAL:
4471 	case VAR_JOB:
4472 	case VAR_CHANNEL:
4473 	    if (verbose)
4474 		EMSG(_("E909: Cannot index a special variable"));
4475 	    return FAIL;
4476 	case VAR_UNKNOWN:
4477 	    if (evaluate)
4478 		return FAIL;
4479 	    /* FALLTHROUGH */
4480 
4481 	case VAR_STRING:
4482 	case VAR_NUMBER:
4483 	case VAR_LIST:
4484 	case VAR_DICT:
4485 	    break;
4486     }
4487 
4488     init_tv(&var1);
4489     init_tv(&var2);
4490     if (**arg == '.')
4491     {
4492 	/*
4493 	 * dict.name
4494 	 */
4495 	key = *arg + 1;
4496 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
4497 	    ;
4498 	if (len == 0)
4499 	    return FAIL;
4500 	*arg = skipwhite(key + len);
4501     }
4502     else
4503     {
4504 	/*
4505 	 * something[idx]
4506 	 *
4507 	 * Get the (first) variable from inside the [].
4508 	 */
4509 	*arg = skipwhite(*arg + 1);
4510 	if (**arg == ':')
4511 	    empty1 = TRUE;
4512 	else if (eval1(arg, &var1, evaluate) == FAIL)	/* recursive! */
4513 	    return FAIL;
4514 	else if (evaluate && get_tv_string_chk(&var1) == NULL)
4515 	{
4516 	    /* not a number or string */
4517 	    clear_tv(&var1);
4518 	    return FAIL;
4519 	}
4520 
4521 	/*
4522 	 * Get the second variable from inside the [:].
4523 	 */
4524 	if (**arg == ':')
4525 	{
4526 	    range = TRUE;
4527 	    *arg = skipwhite(*arg + 1);
4528 	    if (**arg == ']')
4529 		empty2 = TRUE;
4530 	    else if (eval1(arg, &var2, evaluate) == FAIL)	/* recursive! */
4531 	    {
4532 		if (!empty1)
4533 		    clear_tv(&var1);
4534 		return FAIL;
4535 	    }
4536 	    else if (evaluate && get_tv_string_chk(&var2) == NULL)
4537 	    {
4538 		/* not a number or string */
4539 		if (!empty1)
4540 		    clear_tv(&var1);
4541 		clear_tv(&var2);
4542 		return FAIL;
4543 	    }
4544 	}
4545 
4546 	/* Check for the ']'. */
4547 	if (**arg != ']')
4548 	{
4549 	    if (verbose)
4550 		EMSG(_(e_missbrac));
4551 	    clear_tv(&var1);
4552 	    if (range)
4553 		clear_tv(&var2);
4554 	    return FAIL;
4555 	}
4556 	*arg = skipwhite(*arg + 1);	/* skip the ']' */
4557     }
4558 
4559     if (evaluate)
4560     {
4561 	n1 = 0;
4562 	if (!empty1 && rettv->v_type != VAR_DICT)
4563 	{
4564 	    n1 = get_tv_number(&var1);
4565 	    clear_tv(&var1);
4566 	}
4567 	if (range)
4568 	{
4569 	    if (empty2)
4570 		n2 = -1;
4571 	    else
4572 	    {
4573 		n2 = get_tv_number(&var2);
4574 		clear_tv(&var2);
4575 	    }
4576 	}
4577 
4578 	switch (rettv->v_type)
4579 	{
4580 	    case VAR_UNKNOWN:
4581 	    case VAR_FUNC:
4582 	    case VAR_PARTIAL:
4583 	    case VAR_FLOAT:
4584 	    case VAR_SPECIAL:
4585 	    case VAR_JOB:
4586 	    case VAR_CHANNEL:
4587 		break; /* not evaluating, skipping over subscript */
4588 
4589 	    case VAR_NUMBER:
4590 	    case VAR_STRING:
4591 		s = get_tv_string(rettv);
4592 		len = (long)STRLEN(s);
4593 		if (range)
4594 		{
4595 		    /* The resulting variable is a substring.  If the indexes
4596 		     * are out of range the result is empty. */
4597 		    if (n1 < 0)
4598 		    {
4599 			n1 = len + n1;
4600 			if (n1 < 0)
4601 			    n1 = 0;
4602 		    }
4603 		    if (n2 < 0)
4604 			n2 = len + n2;
4605 		    else if (n2 >= len)
4606 			n2 = len;
4607 		    if (n1 >= len || n2 < 0 || n1 > n2)
4608 			s = NULL;
4609 		    else
4610 			s = vim_strnsave(s + n1, (int)(n2 - n1 + 1));
4611 		}
4612 		else
4613 		{
4614 		    /* The resulting variable is a string of a single
4615 		     * character.  If the index is too big or negative the
4616 		     * result is empty. */
4617 		    if (n1 >= len || n1 < 0)
4618 			s = NULL;
4619 		    else
4620 			s = vim_strnsave(s + n1, 1);
4621 		}
4622 		clear_tv(rettv);
4623 		rettv->v_type = VAR_STRING;
4624 		rettv->vval.v_string = s;
4625 		break;
4626 
4627 	    case VAR_LIST:
4628 		len = list_len(rettv->vval.v_list);
4629 		if (n1 < 0)
4630 		    n1 = len + n1;
4631 		if (!empty1 && (n1 < 0 || n1 >= len))
4632 		{
4633 		    /* For a range we allow invalid values and return an empty
4634 		     * list.  A list index out of range is an error. */
4635 		    if (!range)
4636 		    {
4637 			if (verbose)
4638 			    EMSGN(_(e_listidx), n1);
4639 			return FAIL;
4640 		    }
4641 		    n1 = len;
4642 		}
4643 		if (range)
4644 		{
4645 		    list_T	*l;
4646 		    listitem_T	*item;
4647 
4648 		    if (n2 < 0)
4649 			n2 = len + n2;
4650 		    else if (n2 >= len)
4651 			n2 = len - 1;
4652 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
4653 			n2 = -1;
4654 		    l = list_alloc();
4655 		    if (l == NULL)
4656 			return FAIL;
4657 		    for (item = list_find(rettv->vval.v_list, n1);
4658 							       n1 <= n2; ++n1)
4659 		    {
4660 			if (list_append_tv(l, &item->li_tv) == FAIL)
4661 			{
4662 			    list_free(l);
4663 			    return FAIL;
4664 			}
4665 			item = item->li_next;
4666 		    }
4667 		    clear_tv(rettv);
4668 		    rettv->v_type = VAR_LIST;
4669 		    rettv->vval.v_list = l;
4670 		    ++l->lv_refcount;
4671 		}
4672 		else
4673 		{
4674 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
4675 		    clear_tv(rettv);
4676 		    *rettv = var1;
4677 		}
4678 		break;
4679 
4680 	    case VAR_DICT:
4681 		if (range)
4682 		{
4683 		    if (verbose)
4684 			EMSG(_(e_dictrange));
4685 		    if (len == -1)
4686 			clear_tv(&var1);
4687 		    return FAIL;
4688 		}
4689 		{
4690 		    dictitem_T	*item;
4691 
4692 		    if (len == -1)
4693 		    {
4694 			key = get_tv_string_chk(&var1);
4695 			if (key == NULL)
4696 			{
4697 			    clear_tv(&var1);
4698 			    return FAIL;
4699 			}
4700 		    }
4701 
4702 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
4703 
4704 		    if (item == NULL && verbose)
4705 			EMSG2(_(e_dictkey), key);
4706 		    if (len == -1)
4707 			clear_tv(&var1);
4708 		    if (item == NULL)
4709 			return FAIL;
4710 
4711 		    copy_tv(&item->di_tv, &var1);
4712 		    clear_tv(rettv);
4713 		    *rettv = var1;
4714 		}
4715 		break;
4716 	}
4717     }
4718 
4719     return OK;
4720 }
4721 
4722 /*
4723  * Get an option value.
4724  * "arg" points to the '&' or '+' before the option name.
4725  * "arg" is advanced to character after the option name.
4726  * Return OK or FAIL.
4727  */
4728     int
4729 get_option_tv(
4730     char_u	**arg,
4731     typval_T	*rettv,	/* when NULL, only check if option exists */
4732     int		evaluate)
4733 {
4734     char_u	*option_end;
4735     long	numval;
4736     char_u	*stringval;
4737     int		opt_type;
4738     int		c;
4739     int		working = (**arg == '+');    /* has("+option") */
4740     int		ret = OK;
4741     int		opt_flags;
4742 
4743     /*
4744      * Isolate the option name and find its value.
4745      */
4746     option_end = find_option_end(arg, &opt_flags);
4747     if (option_end == NULL)
4748     {
4749 	if (rettv != NULL)
4750 	    EMSG2(_("E112: Option name missing: %s"), *arg);
4751 	return FAIL;
4752     }
4753 
4754     if (!evaluate)
4755     {
4756 	*arg = option_end;
4757 	return OK;
4758     }
4759 
4760     c = *option_end;
4761     *option_end = NUL;
4762     opt_type = get_option_value(*arg, &numval,
4763 			       rettv == NULL ? NULL : &stringval, opt_flags);
4764 
4765     if (opt_type == -3)			/* invalid name */
4766     {
4767 	if (rettv != NULL)
4768 	    EMSG2(_("E113: Unknown option: %s"), *arg);
4769 	ret = FAIL;
4770     }
4771     else if (rettv != NULL)
4772     {
4773 	if (opt_type == -2)		/* hidden string option */
4774 	{
4775 	    rettv->v_type = VAR_STRING;
4776 	    rettv->vval.v_string = NULL;
4777 	}
4778 	else if (opt_type == -1)	/* hidden number option */
4779 	{
4780 	    rettv->v_type = VAR_NUMBER;
4781 	    rettv->vval.v_number = 0;
4782 	}
4783 	else if (opt_type == 1)		/* number option */
4784 	{
4785 	    rettv->v_type = VAR_NUMBER;
4786 	    rettv->vval.v_number = numval;
4787 	}
4788 	else				/* string option */
4789 	{
4790 	    rettv->v_type = VAR_STRING;
4791 	    rettv->vval.v_string = stringval;
4792 	}
4793     }
4794     else if (working && (opt_type == -2 || opt_type == -1))
4795 	ret = FAIL;
4796 
4797     *option_end = c;		    /* put back for error messages */
4798     *arg = option_end;
4799 
4800     return ret;
4801 }
4802 
4803 /*
4804  * Allocate a variable for a string constant.
4805  * Return OK or FAIL.
4806  */
4807     static int
4808 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
4809 {
4810     char_u	*p;
4811     char_u	*name;
4812     int		extra = 0;
4813 
4814     /*
4815      * Find the end of the string, skipping backslashed characters.
4816      */
4817     for (p = *arg + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
4818     {
4819 	if (*p == '\\' && p[1] != NUL)
4820 	{
4821 	    ++p;
4822 	    /* A "\<x>" form occupies at least 4 characters, and produces up
4823 	     * to 6 characters: reserve space for 2 extra */
4824 	    if (*p == '<')
4825 		extra += 2;
4826 	}
4827     }
4828 
4829     if (*p != '"')
4830     {
4831 	EMSG2(_("E114: Missing quote: %s"), *arg);
4832 	return FAIL;
4833     }
4834 
4835     /* If only parsing, set *arg and return here */
4836     if (!evaluate)
4837     {
4838 	*arg = p + 1;
4839 	return OK;
4840     }
4841 
4842     /*
4843      * Copy the string into allocated memory, handling backslashed
4844      * characters.
4845      */
4846     name = alloc((unsigned)(p - *arg + extra));
4847     if (name == NULL)
4848 	return FAIL;
4849     rettv->v_type = VAR_STRING;
4850     rettv->vval.v_string = name;
4851 
4852     for (p = *arg + 1; *p != NUL && *p != '"'; )
4853     {
4854 	if (*p == '\\')
4855 	{
4856 	    switch (*++p)
4857 	    {
4858 		case 'b': *name++ = BS; ++p; break;
4859 		case 'e': *name++ = ESC; ++p; break;
4860 		case 'f': *name++ = FF; ++p; break;
4861 		case 'n': *name++ = NL; ++p; break;
4862 		case 'r': *name++ = CAR; ++p; break;
4863 		case 't': *name++ = TAB; ++p; break;
4864 
4865 		case 'X': /* hex: "\x1", "\x12" */
4866 		case 'x':
4867 		case 'u': /* Unicode: "\u0023" */
4868 		case 'U':
4869 			  if (vim_isxdigit(p[1]))
4870 			  {
4871 			      int	n, nr;
4872 			      int	c = toupper(*p);
4873 
4874 			      if (c == 'X')
4875 				  n = 2;
4876 			      else if (*p == 'u')
4877 				  n = 4;
4878 			      else
4879 				  n = 8;
4880 			      nr = 0;
4881 			      while (--n >= 0 && vim_isxdigit(p[1]))
4882 			      {
4883 				  ++p;
4884 				  nr = (nr << 4) + hex2nr(*p);
4885 			      }
4886 			      ++p;
4887 #ifdef FEAT_MBYTE
4888 			      /* For "\u" store the number according to
4889 			       * 'encoding'. */
4890 			      if (c != 'X')
4891 				  name += (*mb_char2bytes)(nr, name);
4892 			      else
4893 #endif
4894 				  *name++ = nr;
4895 			  }
4896 			  break;
4897 
4898 			  /* octal: "\1", "\12", "\123" */
4899 		case '0':
4900 		case '1':
4901 		case '2':
4902 		case '3':
4903 		case '4':
4904 		case '5':
4905 		case '6':
4906 		case '7': *name = *p++ - '0';
4907 			  if (*p >= '0' && *p <= '7')
4908 			  {
4909 			      *name = (*name << 3) + *p++ - '0';
4910 			      if (*p >= '0' && *p <= '7')
4911 				  *name = (*name << 3) + *p++ - '0';
4912 			  }
4913 			  ++name;
4914 			  break;
4915 
4916 			    /* Special key, e.g.: "\<C-W>" */
4917 		case '<': extra = trans_special(&p, name, TRUE, TRUE);
4918 			  if (extra != 0)
4919 			  {
4920 			      name += extra;
4921 			      break;
4922 			  }
4923 			  /* FALLTHROUGH */
4924 
4925 		default:  MB_COPY_CHAR(p, name);
4926 			  break;
4927 	    }
4928 	}
4929 	else
4930 	    MB_COPY_CHAR(p, name);
4931 
4932     }
4933     *name = NUL;
4934     if (*p != NUL) /* just in case */
4935 	++p;
4936     *arg = p;
4937 
4938     return OK;
4939 }
4940 
4941 /*
4942  * Allocate a variable for a 'str''ing' constant.
4943  * Return OK or FAIL.
4944  */
4945     static int
4946 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
4947 {
4948     char_u	*p;
4949     char_u	*str;
4950     int		reduce = 0;
4951 
4952     /*
4953      * Find the end of the string, skipping ''.
4954      */
4955     for (p = *arg + 1; *p != NUL; MB_PTR_ADV(p))
4956     {
4957 	if (*p == '\'')
4958 	{
4959 	    if (p[1] != '\'')
4960 		break;
4961 	    ++reduce;
4962 	    ++p;
4963 	}
4964     }
4965 
4966     if (*p != '\'')
4967     {
4968 	EMSG2(_("E115: Missing quote: %s"), *arg);
4969 	return FAIL;
4970     }
4971 
4972     /* If only parsing return after setting "*arg" */
4973     if (!evaluate)
4974     {
4975 	*arg = p + 1;
4976 	return OK;
4977     }
4978 
4979     /*
4980      * Copy the string into allocated memory, handling '' to ' reduction.
4981      */
4982     str = alloc((unsigned)((p - *arg) - reduce));
4983     if (str == NULL)
4984 	return FAIL;
4985     rettv->v_type = VAR_STRING;
4986     rettv->vval.v_string = str;
4987 
4988     for (p = *arg + 1; *p != NUL; )
4989     {
4990 	if (*p == '\'')
4991 	{
4992 	    if (p[1] != '\'')
4993 		break;
4994 	    ++p;
4995 	}
4996 	MB_COPY_CHAR(p, str);
4997     }
4998     *str = NUL;
4999     *arg = p + 1;
5000 
5001     return OK;
5002 }
5003 
5004 /*
5005  * Return the function name of the partial.
5006  */
5007     char_u *
5008 partial_name(partial_T *pt)
5009 {
5010     if (pt->pt_name != NULL)
5011 	return pt->pt_name;
5012     return pt->pt_func->uf_name;
5013 }
5014 
5015     static void
5016 partial_free(partial_T *pt)
5017 {
5018     int i;
5019 
5020     for (i = 0; i < pt->pt_argc; ++i)
5021 	clear_tv(&pt->pt_argv[i]);
5022     vim_free(pt->pt_argv);
5023     dict_unref(pt->pt_dict);
5024     if (pt->pt_name != NULL)
5025     {
5026 	func_unref(pt->pt_name);
5027 	vim_free(pt->pt_name);
5028     }
5029     else
5030 	func_ptr_unref(pt->pt_func);
5031     vim_free(pt);
5032 }
5033 
5034 /*
5035  * Unreference a closure: decrement the reference count and free it when it
5036  * becomes zero.
5037  */
5038     void
5039 partial_unref(partial_T *pt)
5040 {
5041     if (pt != NULL && --pt->pt_refcount <= 0)
5042 	partial_free(pt);
5043 }
5044 
5045 static int tv_equal_recurse_limit;
5046 
5047     static int
5048 func_equal(
5049     typval_T *tv1,
5050     typval_T *tv2,
5051     int	     ic)	    /* ignore case */
5052 {
5053     char_u	*s1, *s2;
5054     dict_T	*d1, *d2;
5055     int		a1, a2;
5056     int		i;
5057 
5058     /* empty and NULL function name considered the same */
5059     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
5060 					   : partial_name(tv1->vval.v_partial);
5061     if (s1 != NULL && *s1 == NUL)
5062 	s1 = NULL;
5063     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
5064 					   : partial_name(tv2->vval.v_partial);
5065     if (s2 != NULL && *s2 == NUL)
5066 	s2 = NULL;
5067     if (s1 == NULL || s2 == NULL)
5068     {
5069 	if (s1 != s2)
5070 	    return FALSE;
5071     }
5072     else if (STRCMP(s1, s2) != 0)
5073 	return FALSE;
5074 
5075     /* empty dict and NULL dict is different */
5076     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
5077     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
5078     if (d1 == NULL || d2 == NULL)
5079     {
5080 	if (d1 != d2)
5081 	    return FALSE;
5082     }
5083     else if (!dict_equal(d1, d2, ic, TRUE))
5084 	return FALSE;
5085 
5086     /* empty list and no list considered the same */
5087     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
5088     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
5089     if (a1 != a2)
5090 	return FALSE;
5091     for (i = 0; i < a1; ++i)
5092 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
5093 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
5094 	    return FALSE;
5095 
5096     return TRUE;
5097 }
5098 
5099 /*
5100  * Return TRUE if "tv1" and "tv2" have the same value.
5101  * Compares the items just like "==" would compare them, but strings and
5102  * numbers are different.  Floats and numbers are also different.
5103  */
5104     int
5105 tv_equal(
5106     typval_T *tv1,
5107     typval_T *tv2,
5108     int	     ic,	    /* ignore case */
5109     int	     recursive)	    /* TRUE when used recursively */
5110 {
5111     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
5112     char_u	*s1, *s2;
5113     static int  recursive_cnt = 0;	    /* catch recursive loops */
5114     int		r;
5115 
5116     /* Catch lists and dicts that have an endless loop by limiting
5117      * recursiveness to a limit.  We guess they are equal then.
5118      * A fixed limit has the problem of still taking an awful long time.
5119      * Reduce the limit every time running into it. That should work fine for
5120      * deeply linked structures that are not recursively linked and catch
5121      * recursiveness quickly. */
5122     if (!recursive)
5123 	tv_equal_recurse_limit = 1000;
5124     if (recursive_cnt >= tv_equal_recurse_limit)
5125     {
5126 	--tv_equal_recurse_limit;
5127 	return TRUE;
5128     }
5129 
5130     /* For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
5131      * arguments. */
5132     if ((tv1->v_type == VAR_FUNC
5133 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
5134 	    && (tv2->v_type == VAR_FUNC
5135 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
5136     {
5137 	++recursive_cnt;
5138 	r = func_equal(tv1, tv2, ic);
5139 	--recursive_cnt;
5140 	return r;
5141     }
5142 
5143     if (tv1->v_type != tv2->v_type)
5144 	return FALSE;
5145 
5146     switch (tv1->v_type)
5147     {
5148 	case VAR_LIST:
5149 	    ++recursive_cnt;
5150 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
5151 	    --recursive_cnt;
5152 	    return r;
5153 
5154 	case VAR_DICT:
5155 	    ++recursive_cnt;
5156 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
5157 	    --recursive_cnt;
5158 	    return r;
5159 
5160 	case VAR_NUMBER:
5161 	    return tv1->vval.v_number == tv2->vval.v_number;
5162 
5163 	case VAR_STRING:
5164 	    s1 = get_tv_string_buf(tv1, buf1);
5165 	    s2 = get_tv_string_buf(tv2, buf2);
5166 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
5167 
5168 	case VAR_SPECIAL:
5169 	    return tv1->vval.v_number == tv2->vval.v_number;
5170 
5171 	case VAR_FLOAT:
5172 #ifdef FEAT_FLOAT
5173 	    return tv1->vval.v_float == tv2->vval.v_float;
5174 #endif
5175 	case VAR_JOB:
5176 #ifdef FEAT_JOB_CHANNEL
5177 	    return tv1->vval.v_job == tv2->vval.v_job;
5178 #endif
5179 	case VAR_CHANNEL:
5180 #ifdef FEAT_JOB_CHANNEL
5181 	    return tv1->vval.v_channel == tv2->vval.v_channel;
5182 #endif
5183 	case VAR_FUNC:
5184 	case VAR_PARTIAL:
5185 	case VAR_UNKNOWN:
5186 	    break;
5187     }
5188 
5189     /* VAR_UNKNOWN can be the result of a invalid expression, let's say it
5190      * does not equal anything, not even itself. */
5191     return FALSE;
5192 }
5193 
5194 /*
5195  * Return the next (unique) copy ID.
5196  * Used for serializing nested structures.
5197  */
5198     int
5199 get_copyID(void)
5200 {
5201     current_copyID += COPYID_INC;
5202     return current_copyID;
5203 }
5204 
5205 /*
5206  * Garbage collection for lists and dictionaries.
5207  *
5208  * We use reference counts to be able to free most items right away when they
5209  * are no longer used.  But for composite items it's possible that it becomes
5210  * unused while the reference count is > 0: When there is a recursive
5211  * reference.  Example:
5212  *	:let l = [1, 2, 3]
5213  *	:let d = {9: l}
5214  *	:let l[1] = d
5215  *
5216  * Since this is quite unusual we handle this with garbage collection: every
5217  * once in a while find out which lists and dicts are not referenced from any
5218  * variable.
5219  *
5220  * Here is a good reference text about garbage collection (refers to Python
5221  * but it applies to all reference-counting mechanisms):
5222  *	http://python.ca/nas/python/gc/
5223  */
5224 
5225 /*
5226  * Do garbage collection for lists and dicts.
5227  * When "testing" is TRUE this is called from test_garbagecollect_now().
5228  * Return TRUE if some memory was freed.
5229  */
5230     int
5231 garbage_collect(int testing)
5232 {
5233     int		copyID;
5234     int		abort = FALSE;
5235     buf_T	*buf;
5236     win_T	*wp;
5237     int		i;
5238     int		did_free = FALSE;
5239 #ifdef FEAT_WINDOWS
5240     tabpage_T	*tp;
5241 #endif
5242 
5243     if (!testing)
5244     {
5245 	/* Only do this once. */
5246 	want_garbage_collect = FALSE;
5247 	may_garbage_collect = FALSE;
5248 	garbage_collect_at_exit = FALSE;
5249     }
5250 
5251     /* We advance by two because we add one for items referenced through
5252      * previous_funccal. */
5253     copyID = get_copyID();
5254 
5255     /*
5256      * 1. Go through all accessible variables and mark all lists and dicts
5257      *    with copyID.
5258      */
5259 
5260     /* Don't free variables in the previous_funccal list unless they are only
5261      * referenced through previous_funccal.  This must be first, because if
5262      * the item is referenced elsewhere the funccal must not be freed. */
5263     abort = abort || set_ref_in_previous_funccal(copyID);
5264 
5265     /* script-local variables */
5266     for (i = 1; i <= ga_scripts.ga_len; ++i)
5267 	abort = abort || set_ref_in_ht(&SCRIPT_VARS(i), copyID, NULL);
5268 
5269     /* buffer-local variables */
5270     FOR_ALL_BUFFERS(buf)
5271 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
5272 								  NULL, NULL);
5273 
5274     /* window-local variables */
5275     FOR_ALL_TAB_WINDOWS(tp, wp)
5276 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
5277 								  NULL, NULL);
5278 #ifdef FEAT_AUTOCMD
5279     if (aucmd_win != NULL)
5280 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
5281 								  NULL, NULL);
5282 #endif
5283 
5284 #ifdef FEAT_WINDOWS
5285     /* tabpage-local variables */
5286     FOR_ALL_TABPAGES(tp)
5287 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
5288 								  NULL, NULL);
5289 #endif
5290 
5291     /* global variables */
5292     abort = abort || set_ref_in_ht(&globvarht, copyID, NULL);
5293 
5294     /* function-local variables */
5295     abort = abort || set_ref_in_call_stack(copyID);
5296 
5297     /* named functions (matters for closures) */
5298     abort = abort || set_ref_in_functions(copyID);
5299 
5300     /* function call arguments, if v:testing is set. */
5301     abort = abort || set_ref_in_func_args(copyID);
5302 
5303     /* v: vars */
5304     abort = abort || set_ref_in_ht(&vimvarht, copyID, NULL);
5305 
5306 #ifdef FEAT_LUA
5307     abort = abort || set_ref_in_lua(copyID);
5308 #endif
5309 
5310 #ifdef FEAT_PYTHON
5311     abort = abort || set_ref_in_python(copyID);
5312 #endif
5313 
5314 #ifdef FEAT_PYTHON3
5315     abort = abort || set_ref_in_python3(copyID);
5316 #endif
5317 
5318 #ifdef FEAT_JOB_CHANNEL
5319     abort = abort || set_ref_in_channel(copyID);
5320     abort = abort || set_ref_in_job(copyID);
5321 #endif
5322 #ifdef FEAT_NETBEANS_INTG
5323     abort = abort || set_ref_in_nb_channel(copyID);
5324 #endif
5325 
5326 #ifdef FEAT_TIMERS
5327     abort = abort || set_ref_in_timer(copyID);
5328 #endif
5329 
5330     if (!abort)
5331     {
5332 	/*
5333 	 * 2. Free lists and dictionaries that are not referenced.
5334 	 */
5335 	did_free = free_unref_items(copyID);
5336 
5337 	/*
5338 	 * 3. Check if any funccal can be freed now.
5339 	 *    This may call us back recursively.
5340 	 */
5341 	free_unref_funccal(copyID, testing);
5342     }
5343     else if (p_verbose > 0)
5344     {
5345 	verb_msg((char_u *)_("Not enough memory to set references, garbage collection aborted!"));
5346     }
5347 
5348     return did_free;
5349 }
5350 
5351 /*
5352  * Free lists, dictionaries, channels and jobs that are no longer referenced.
5353  */
5354     static int
5355 free_unref_items(int copyID)
5356 {
5357     int		did_free = FALSE;
5358 
5359     /* Let all "free" functions know that we are here.  This means no
5360      * dictionaries, lists, channels or jobs are to be freed, because we will
5361      * do that here. */
5362     in_free_unref_items = TRUE;
5363 
5364     /*
5365      * PASS 1: free the contents of the items.  We don't free the items
5366      * themselves yet, so that it is possible to decrement refcount counters
5367      */
5368 
5369     /* Go through the list of dicts and free items without the copyID. */
5370     did_free |= dict_free_nonref(copyID);
5371 
5372     /* Go through the list of lists and free items without the copyID. */
5373     did_free |= list_free_nonref(copyID);
5374 
5375 #ifdef FEAT_JOB_CHANNEL
5376     /* Go through the list of jobs and free items without the copyID. This
5377      * must happen before doing channels, because jobs refer to channels, but
5378      * the reference from the channel to the job isn't tracked. */
5379     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
5380 
5381     /* Go through the list of channels and free items without the copyID.  */
5382     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
5383 #endif
5384 
5385     /*
5386      * PASS 2: free the items themselves.
5387      */
5388     dict_free_items(copyID);
5389     list_free_items(copyID);
5390 
5391 #ifdef FEAT_JOB_CHANNEL
5392     /* Go through the list of jobs and free items without the copyID. This
5393      * must happen before doing channels, because jobs refer to channels, but
5394      * the reference from the channel to the job isn't tracked. */
5395     free_unused_jobs(copyID, COPYID_MASK);
5396 
5397     /* Go through the list of channels and free items without the copyID.  */
5398     free_unused_channels(copyID, COPYID_MASK);
5399 #endif
5400 
5401     in_free_unref_items = FALSE;
5402 
5403     return did_free;
5404 }
5405 
5406 /*
5407  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
5408  * "list_stack" is used to add lists to be marked.  Can be NULL.
5409  *
5410  * Returns TRUE if setting references failed somehow.
5411  */
5412     int
5413 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
5414 {
5415     int		todo;
5416     int		abort = FALSE;
5417     hashitem_T	*hi;
5418     hashtab_T	*cur_ht;
5419     ht_stack_T	*ht_stack = NULL;
5420     ht_stack_T	*tempitem;
5421 
5422     cur_ht = ht;
5423     for (;;)
5424     {
5425 	if (!abort)
5426 	{
5427 	    /* Mark each item in the hashtab.  If the item contains a hashtab
5428 	     * it is added to ht_stack, if it contains a list it is added to
5429 	     * list_stack. */
5430 	    todo = (int)cur_ht->ht_used;
5431 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
5432 		if (!HASHITEM_EMPTY(hi))
5433 		{
5434 		    --todo;
5435 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
5436 						       &ht_stack, list_stack);
5437 		}
5438 	}
5439 
5440 	if (ht_stack == NULL)
5441 	    break;
5442 
5443 	/* take an item from the stack */
5444 	cur_ht = ht_stack->ht;
5445 	tempitem = ht_stack;
5446 	ht_stack = ht_stack->prev;
5447 	free(tempitem);
5448     }
5449 
5450     return abort;
5451 }
5452 
5453 /*
5454  * Mark all lists and dicts referenced through list "l" with "copyID".
5455  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5456  *
5457  * Returns TRUE if setting references failed somehow.
5458  */
5459     int
5460 set_ref_in_list(list_T *l, int copyID, ht_stack_T **ht_stack)
5461 {
5462     listitem_T	 *li;
5463     int		 abort = FALSE;
5464     list_T	 *cur_l;
5465     list_stack_T *list_stack = NULL;
5466     list_stack_T *tempitem;
5467 
5468     cur_l = l;
5469     for (;;)
5470     {
5471 	if (!abort)
5472 	    /* Mark each item in the list.  If the item contains a hashtab
5473 	     * it is added to ht_stack, if it contains a list it is added to
5474 	     * list_stack. */
5475 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
5476 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
5477 						       ht_stack, &list_stack);
5478 	if (list_stack == NULL)
5479 	    break;
5480 
5481 	/* take an item from the stack */
5482 	cur_l = list_stack->list;
5483 	tempitem = list_stack;
5484 	list_stack = list_stack->prev;
5485 	free(tempitem);
5486     }
5487 
5488     return abort;
5489 }
5490 
5491 /*
5492  * Mark all lists and dicts referenced through typval "tv" with "copyID".
5493  * "list_stack" is used to add lists to be marked.  Can be NULL.
5494  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5495  *
5496  * Returns TRUE if setting references failed somehow.
5497  */
5498     int
5499 set_ref_in_item(
5500     typval_T	    *tv,
5501     int		    copyID,
5502     ht_stack_T	    **ht_stack,
5503     list_stack_T    **list_stack)
5504 {
5505     int		abort = FALSE;
5506 
5507     if (tv->v_type == VAR_DICT)
5508     {
5509 	dict_T	*dd = tv->vval.v_dict;
5510 
5511 	if (dd != NULL && dd->dv_copyID != copyID)
5512 	{
5513 	    /* Didn't see this dict yet. */
5514 	    dd->dv_copyID = copyID;
5515 	    if (ht_stack == NULL)
5516 	    {
5517 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
5518 	    }
5519 	    else
5520 	    {
5521 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
5522 		if (newitem == NULL)
5523 		    abort = TRUE;
5524 		else
5525 		{
5526 		    newitem->ht = &dd->dv_hashtab;
5527 		    newitem->prev = *ht_stack;
5528 		    *ht_stack = newitem;
5529 		}
5530 	    }
5531 	}
5532     }
5533     else if (tv->v_type == VAR_LIST)
5534     {
5535 	list_T	*ll = tv->vval.v_list;
5536 
5537 	if (ll != NULL && ll->lv_copyID != copyID)
5538 	{
5539 	    /* Didn't see this list yet. */
5540 	    ll->lv_copyID = copyID;
5541 	    if (list_stack == NULL)
5542 	    {
5543 		abort = set_ref_in_list(ll, copyID, ht_stack);
5544 	    }
5545 	    else
5546 	    {
5547 		list_stack_T *newitem = (list_stack_T*)malloc(
5548 							sizeof(list_stack_T));
5549 		if (newitem == NULL)
5550 		    abort = TRUE;
5551 		else
5552 		{
5553 		    newitem->list = ll;
5554 		    newitem->prev = *list_stack;
5555 		    *list_stack = newitem;
5556 		}
5557 	    }
5558 	}
5559     }
5560     else if (tv->v_type == VAR_FUNC)
5561     {
5562 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
5563     }
5564     else if (tv->v_type == VAR_PARTIAL)
5565     {
5566 	partial_T	*pt = tv->vval.v_partial;
5567 	int		i;
5568 
5569 	/* A partial does not have a copyID, because it cannot contain itself.
5570 	 */
5571 	if (pt != NULL)
5572 	{
5573 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
5574 
5575 	    if (pt->pt_dict != NULL)
5576 	    {
5577 		typval_T dtv;
5578 
5579 		dtv.v_type = VAR_DICT;
5580 		dtv.vval.v_dict = pt->pt_dict;
5581 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5582 	    }
5583 
5584 	    for (i = 0; i < pt->pt_argc; ++i)
5585 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
5586 							ht_stack, list_stack);
5587 	}
5588     }
5589 #ifdef FEAT_JOB_CHANNEL
5590     else if (tv->v_type == VAR_JOB)
5591     {
5592 	job_T	    *job = tv->vval.v_job;
5593 	typval_T    dtv;
5594 
5595 	if (job != NULL && job->jv_copyID != copyID)
5596 	{
5597 	    job->jv_copyID = copyID;
5598 	    if (job->jv_channel != NULL)
5599 	    {
5600 		dtv.v_type = VAR_CHANNEL;
5601 		dtv.vval.v_channel = job->jv_channel;
5602 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5603 	    }
5604 	    if (job->jv_exit_partial != NULL)
5605 	    {
5606 		dtv.v_type = VAR_PARTIAL;
5607 		dtv.vval.v_partial = job->jv_exit_partial;
5608 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5609 	    }
5610 	}
5611     }
5612     else if (tv->v_type == VAR_CHANNEL)
5613     {
5614 	channel_T   *ch =tv->vval.v_channel;
5615 	ch_part_T   part;
5616 	typval_T    dtv;
5617 	jsonq_T	    *jq;
5618 	cbq_T	    *cq;
5619 
5620 	if (ch != NULL && ch->ch_copyID != copyID)
5621 	{
5622 	    ch->ch_copyID = copyID;
5623 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
5624 	    {
5625 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
5626 							     jq = jq->jq_next)
5627 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
5628 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
5629 							     cq = cq->cq_next)
5630 		    if (cq->cq_partial != NULL)
5631 		    {
5632 			dtv.v_type = VAR_PARTIAL;
5633 			dtv.vval.v_partial = cq->cq_partial;
5634 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5635 		    }
5636 		if (ch->ch_part[part].ch_partial != NULL)
5637 		{
5638 		    dtv.v_type = VAR_PARTIAL;
5639 		    dtv.vval.v_partial = ch->ch_part[part].ch_partial;
5640 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5641 		}
5642 	    }
5643 	    if (ch->ch_partial != NULL)
5644 	    {
5645 		dtv.v_type = VAR_PARTIAL;
5646 		dtv.vval.v_partial = ch->ch_partial;
5647 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5648 	    }
5649 	    if (ch->ch_close_partial != NULL)
5650 	    {
5651 		dtv.v_type = VAR_PARTIAL;
5652 		dtv.vval.v_partial = ch->ch_close_partial;
5653 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5654 	    }
5655 	}
5656     }
5657 #endif
5658     return abort;
5659 }
5660 
5661     static char *
5662 get_var_special_name(int nr)
5663 {
5664     switch (nr)
5665     {
5666 	case VVAL_FALSE: return "v:false";
5667 	case VVAL_TRUE:  return "v:true";
5668 	case VVAL_NONE:  return "v:none";
5669 	case VVAL_NULL:  return "v:null";
5670     }
5671     internal_error("get_var_special_name()");
5672     return "42";
5673 }
5674 
5675 /*
5676  * Return a string with the string representation of a variable.
5677  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5678  * "numbuf" is used for a number.
5679  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5680  * When both "echo_style" and "dict_val" are FALSE, put quotes around stings as
5681  * "string()", otherwise does not put quotes around strings, as ":echo"
5682  * displays values.
5683  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
5684  * are replaced with "...".
5685  * May return NULL.
5686  */
5687     char_u *
5688 echo_string_core(
5689     typval_T	*tv,
5690     char_u	**tofree,
5691     char_u	*numbuf,
5692     int		copyID,
5693     int		echo_style,
5694     int		restore_copyID,
5695     int		dict_val)
5696 {
5697     static int	recurse = 0;
5698     char_u	*r = NULL;
5699 
5700     if (recurse >= DICT_MAXNEST)
5701     {
5702 	if (!did_echo_string_emsg)
5703 	{
5704 	    /* Only give this message once for a recursive call to avoid
5705 	     * flooding the user with errors.  And stop iterating over lists
5706 	     * and dicts. */
5707 	    did_echo_string_emsg = TRUE;
5708 	    EMSG(_("E724: variable nested too deep for displaying"));
5709 	}
5710 	*tofree = NULL;
5711 	return (char_u *)"{E724}";
5712     }
5713     ++recurse;
5714 
5715     switch (tv->v_type)
5716     {
5717 	case VAR_STRING:
5718 	    if (echo_style && !dict_val)
5719 	    {
5720 		*tofree = NULL;
5721 		r = get_tv_string_buf(tv, numbuf);
5722 	    }
5723 	    else
5724 	    {
5725 		*tofree = string_quote(tv->vval.v_string, FALSE);
5726 		r = *tofree;
5727 	    }
5728 	    break;
5729 
5730 	case VAR_FUNC:
5731 	    if (echo_style)
5732 	    {
5733 		*tofree = NULL;
5734 		r = tv->vval.v_string;
5735 	    }
5736 	    else
5737 	    {
5738 		*tofree = string_quote(tv->vval.v_string, TRUE);
5739 		r = *tofree;
5740 	    }
5741 	    break;
5742 
5743 	case VAR_PARTIAL:
5744 	    {
5745 		partial_T   *pt = tv->vval.v_partial;
5746 		char_u	    *fname = string_quote(pt == NULL ? NULL
5747 						    : partial_name(pt), FALSE);
5748 		garray_T    ga;
5749 		int	    i;
5750 		char_u	    *tf;
5751 
5752 		ga_init2(&ga, 1, 100);
5753 		ga_concat(&ga, (char_u *)"function(");
5754 		if (fname != NULL)
5755 		{
5756 		    ga_concat(&ga, fname);
5757 		    vim_free(fname);
5758 		}
5759 		if (pt != NULL && pt->pt_argc > 0)
5760 		{
5761 		    ga_concat(&ga, (char_u *)", [");
5762 		    for (i = 0; i < pt->pt_argc; ++i)
5763 		    {
5764 			if (i > 0)
5765 			    ga_concat(&ga, (char_u *)", ");
5766 			ga_concat(&ga,
5767 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
5768 			vim_free(tf);
5769 		    }
5770 		    ga_concat(&ga, (char_u *)"]");
5771 		}
5772 		if (pt != NULL && pt->pt_dict != NULL)
5773 		{
5774 		    typval_T dtv;
5775 
5776 		    ga_concat(&ga, (char_u *)", ");
5777 		    dtv.v_type = VAR_DICT;
5778 		    dtv.vval.v_dict = pt->pt_dict;
5779 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
5780 		    vim_free(tf);
5781 		}
5782 		ga_concat(&ga, (char_u *)")");
5783 
5784 		*tofree = ga.ga_data;
5785 		r = *tofree;
5786 		break;
5787 	    }
5788 
5789 	case VAR_LIST:
5790 	    if (tv->vval.v_list == NULL)
5791 	    {
5792 		*tofree = NULL;
5793 		r = NULL;
5794 	    }
5795 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
5796 		    && tv->vval.v_list->lv_len > 0)
5797 	    {
5798 		*tofree = NULL;
5799 		r = (char_u *)"[...]";
5800 	    }
5801 	    else
5802 	    {
5803 		int old_copyID = tv->vval.v_list->lv_copyID;
5804 
5805 		tv->vval.v_list->lv_copyID = copyID;
5806 		*tofree = list2string(tv, copyID, restore_copyID);
5807 		if (restore_copyID)
5808 		    tv->vval.v_list->lv_copyID = old_copyID;
5809 		r = *tofree;
5810 	    }
5811 	    break;
5812 
5813 	case VAR_DICT:
5814 	    if (tv->vval.v_dict == NULL)
5815 	    {
5816 		*tofree = NULL;
5817 		r = NULL;
5818 	    }
5819 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
5820 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
5821 	    {
5822 		*tofree = NULL;
5823 		r = (char_u *)"{...}";
5824 	    }
5825 	    else
5826 	    {
5827 		int old_copyID = tv->vval.v_dict->dv_copyID;
5828 		tv->vval.v_dict->dv_copyID = copyID;
5829 		*tofree = dict2string(tv, copyID, restore_copyID);
5830 		if (restore_copyID)
5831 		    tv->vval.v_dict->dv_copyID = old_copyID;
5832 		r = *tofree;
5833 	    }
5834 	    break;
5835 
5836 	case VAR_NUMBER:
5837 	case VAR_UNKNOWN:
5838 	case VAR_JOB:
5839 	case VAR_CHANNEL:
5840 	    *tofree = NULL;
5841 	    r = get_tv_string_buf(tv, numbuf);
5842 	    break;
5843 
5844 	case VAR_FLOAT:
5845 #ifdef FEAT_FLOAT
5846 	    *tofree = NULL;
5847 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
5848 	    r = numbuf;
5849 	    break;
5850 #endif
5851 
5852 	case VAR_SPECIAL:
5853 	    *tofree = NULL;
5854 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
5855 	    break;
5856     }
5857 
5858     if (--recurse == 0)
5859 	did_echo_string_emsg = FALSE;
5860     return r;
5861 }
5862 
5863 /*
5864  * Return a string with the string representation of a variable.
5865  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5866  * "numbuf" is used for a number.
5867  * Does not put quotes around strings, as ":echo" displays values.
5868  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5869  * May return NULL.
5870  */
5871     char_u *
5872 echo_string(
5873     typval_T	*tv,
5874     char_u	**tofree,
5875     char_u	*numbuf,
5876     int		copyID)
5877 {
5878     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
5879 }
5880 
5881 /*
5882  * Return a string with the string representation of a variable.
5883  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5884  * "numbuf" is used for a number.
5885  * Puts quotes around strings, so that they can be parsed back by eval().
5886  * May return NULL.
5887  */
5888     char_u *
5889 tv2string(
5890     typval_T	*tv,
5891     char_u	**tofree,
5892     char_u	*numbuf,
5893     int		copyID)
5894 {
5895     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
5896 }
5897 
5898 /*
5899  * Return string "str" in ' quotes, doubling ' characters.
5900  * If "str" is NULL an empty string is assumed.
5901  * If "function" is TRUE make it function('string').
5902  */
5903     char_u *
5904 string_quote(char_u *str, int function)
5905 {
5906     unsigned	len;
5907     char_u	*p, *r, *s;
5908 
5909     len = (function ? 13 : 3);
5910     if (str != NULL)
5911     {
5912 	len += (unsigned)STRLEN(str);
5913 	for (p = str; *p != NUL; MB_PTR_ADV(p))
5914 	    if (*p == '\'')
5915 		++len;
5916     }
5917     s = r = alloc(len);
5918     if (r != NULL)
5919     {
5920 	if (function)
5921 	{
5922 	    STRCPY(r, "function('");
5923 	    r += 10;
5924 	}
5925 	else
5926 	    *r++ = '\'';
5927 	if (str != NULL)
5928 	    for (p = str; *p != NUL; )
5929 	    {
5930 		if (*p == '\'')
5931 		    *r++ = '\'';
5932 		MB_COPY_CHAR(p, r);
5933 	    }
5934 	*r++ = '\'';
5935 	if (function)
5936 	    *r++ = ')';
5937 	*r++ = NUL;
5938     }
5939     return s;
5940 }
5941 
5942 #if defined(FEAT_FLOAT) || defined(PROTO)
5943 /*
5944  * Convert the string "text" to a floating point number.
5945  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
5946  * this always uses a decimal point.
5947  * Returns the length of the text that was consumed.
5948  */
5949     int
5950 string2float(
5951     char_u	*text,
5952     float_T	*value)	    /* result stored here */
5953 {
5954     char	*s = (char *)text;
5955     float_T	f;
5956 
5957     /* MS-Windows does not deal with "inf" and "nan" properly. */
5958     if (STRNICMP(text, "inf", 3) == 0)
5959     {
5960 	*value = INFINITY;
5961 	return 3;
5962     }
5963     if (STRNICMP(text, "-inf", 3) == 0)
5964     {
5965 	*value = -INFINITY;
5966 	return 4;
5967     }
5968     if (STRNICMP(text, "nan", 3) == 0)
5969     {
5970 	*value = NAN;
5971 	return 3;
5972     }
5973     f = strtod(s, &s);
5974     *value = f;
5975     return (int)((char_u *)s - text);
5976 }
5977 #endif
5978 
5979 /*
5980  * Get the value of an environment variable.
5981  * "arg" is pointing to the '$'.  It is advanced to after the name.
5982  * If the environment variable was not set, silently assume it is empty.
5983  * Return FAIL if the name is invalid.
5984  */
5985     static int
5986 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
5987 {
5988     char_u	*string = NULL;
5989     int		len;
5990     int		cc;
5991     char_u	*name;
5992     int		mustfree = FALSE;
5993 
5994     ++*arg;
5995     name = *arg;
5996     len = get_env_len(arg);
5997     if (evaluate)
5998     {
5999 	if (len == 0)
6000 	    return FAIL; /* invalid empty name */
6001 
6002 	cc = name[len];
6003 	name[len] = NUL;
6004 	/* first try vim_getenv(), fast for normal environment vars */
6005 	string = vim_getenv(name, &mustfree);
6006 	if (string != NULL && *string != NUL)
6007 	{
6008 	    if (!mustfree)
6009 		string = vim_strsave(string);
6010 	}
6011 	else
6012 	{
6013 	    if (mustfree)
6014 		vim_free(string);
6015 
6016 	    /* next try expanding things like $VIM and ${HOME} */
6017 	    string = expand_env_save(name - 1);
6018 	    if (string != NULL && *string == '$')
6019 	    {
6020 		vim_free(string);
6021 		string = NULL;
6022 	    }
6023 	}
6024 	name[len] = cc;
6025 
6026 	rettv->v_type = VAR_STRING;
6027 	rettv->vval.v_string = string;
6028     }
6029 
6030     return OK;
6031 }
6032 
6033 
6034 
6035 /*
6036  * Translate a String variable into a position.
6037  * Returns NULL when there is an error.
6038  */
6039     pos_T *
6040 var2fpos(
6041     typval_T	*varp,
6042     int		dollar_lnum,	/* TRUE when $ is last line */
6043     int		*fnum)		/* set to fnum for '0, 'A, etc. */
6044 {
6045     char_u		*name;
6046     static pos_T	pos;
6047     pos_T		*pp;
6048 
6049     /* Argument can be [lnum, col, coladd]. */
6050     if (varp->v_type == VAR_LIST)
6051     {
6052 	list_T		*l;
6053 	int		len;
6054 	int		error = FALSE;
6055 	listitem_T	*li;
6056 
6057 	l = varp->vval.v_list;
6058 	if (l == NULL)
6059 	    return NULL;
6060 
6061 	/* Get the line number */
6062 	pos.lnum = list_find_nr(l, 0L, &error);
6063 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
6064 	    return NULL;	/* invalid line number */
6065 
6066 	/* Get the column number */
6067 	pos.col = list_find_nr(l, 1L, &error);
6068 	if (error)
6069 	    return NULL;
6070 	len = (long)STRLEN(ml_get(pos.lnum));
6071 
6072 	/* We accept "$" for the column number: last column. */
6073 	li = list_find(l, 1L);
6074 	if (li != NULL && li->li_tv.v_type == VAR_STRING
6075 		&& li->li_tv.vval.v_string != NULL
6076 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
6077 	    pos.col = len + 1;
6078 
6079 	/* Accept a position up to the NUL after the line. */
6080 	if (pos.col == 0 || (int)pos.col > len + 1)
6081 	    return NULL;	/* invalid column number */
6082 	--pos.col;
6083 
6084 #ifdef FEAT_VIRTUALEDIT
6085 	/* Get the virtual offset.  Defaults to zero. */
6086 	pos.coladd = list_find_nr(l, 2L, &error);
6087 	if (error)
6088 	    pos.coladd = 0;
6089 #endif
6090 
6091 	return &pos;
6092     }
6093 
6094     name = get_tv_string_chk(varp);
6095     if (name == NULL)
6096 	return NULL;
6097     if (name[0] == '.')				/* cursor */
6098 	return &curwin->w_cursor;
6099     if (name[0] == 'v' && name[1] == NUL)	/* Visual start */
6100     {
6101 	if (VIsual_active)
6102 	    return &VIsual;
6103 	return &curwin->w_cursor;
6104     }
6105     if (name[0] == '\'')			/* mark */
6106     {
6107 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
6108 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
6109 	    return NULL;
6110 	return pp;
6111     }
6112 
6113 #ifdef FEAT_VIRTUALEDIT
6114     pos.coladd = 0;
6115 #endif
6116 
6117     if (name[0] == 'w' && dollar_lnum)
6118     {
6119 	pos.col = 0;
6120 	if (name[1] == '0')		/* "w0": first visible line */
6121 	{
6122 	    update_topline();
6123 	    /* In silent Ex mode topline is zero, but that's not a valid line
6124 	     * number; use one instead. */
6125 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
6126 	    return &pos;
6127 	}
6128 	else if (name[1] == '$')	/* "w$": last visible line */
6129 	{
6130 	    validate_botline();
6131 	    /* In silent Ex mode botline is zero, return zero then. */
6132 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
6133 	    return &pos;
6134 	}
6135     }
6136     else if (name[0] == '$')		/* last column or line */
6137     {
6138 	if (dollar_lnum)
6139 	{
6140 	    pos.lnum = curbuf->b_ml.ml_line_count;
6141 	    pos.col = 0;
6142 	}
6143 	else
6144 	{
6145 	    pos.lnum = curwin->w_cursor.lnum;
6146 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
6147 	}
6148 	return &pos;
6149     }
6150     return NULL;
6151 }
6152 
6153 /*
6154  * Convert list in "arg" into a position and optional file number.
6155  * When "fnump" is NULL there is no file number, only 3 items.
6156  * Note that the column is passed on as-is, the caller may want to decrement
6157  * it to use 1 for the first column.
6158  * Return FAIL when conversion is not possible, doesn't check the position for
6159  * validity.
6160  */
6161     int
6162 list2fpos(
6163     typval_T	*arg,
6164     pos_T	*posp,
6165     int		*fnump,
6166     colnr_T	*curswantp)
6167 {
6168     list_T	*l = arg->vval.v_list;
6169     long	i = 0;
6170     long	n;
6171 
6172     /* List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
6173      * there when "fnump" isn't NULL; "coladd" and "curswant" are optional. */
6174     if (arg->v_type != VAR_LIST
6175 	    || l == NULL
6176 	    || l->lv_len < (fnump == NULL ? 2 : 3)
6177 	    || l->lv_len > (fnump == NULL ? 4 : 5))
6178 	return FAIL;
6179 
6180     if (fnump != NULL)
6181     {
6182 	n = list_find_nr(l, i++, NULL);	/* fnum */
6183 	if (n < 0)
6184 	    return FAIL;
6185 	if (n == 0)
6186 	    n = curbuf->b_fnum;		/* current buffer */
6187 	*fnump = n;
6188     }
6189 
6190     n = list_find_nr(l, i++, NULL);	/* lnum */
6191     if (n < 0)
6192 	return FAIL;
6193     posp->lnum = n;
6194 
6195     n = list_find_nr(l, i++, NULL);	/* col */
6196     if (n < 0)
6197 	return FAIL;
6198     posp->col = n;
6199 
6200 #ifdef FEAT_VIRTUALEDIT
6201     n = list_find_nr(l, i, NULL);	/* off */
6202     if (n < 0)
6203 	posp->coladd = 0;
6204     else
6205 	posp->coladd = n;
6206 #endif
6207 
6208     if (curswantp != NULL)
6209 	*curswantp = list_find_nr(l, i + 1, NULL);  /* curswant */
6210 
6211     return OK;
6212 }
6213 
6214 /*
6215  * Get the length of an environment variable name.
6216  * Advance "arg" to the first character after the name.
6217  * Return 0 for error.
6218  */
6219     static int
6220 get_env_len(char_u **arg)
6221 {
6222     char_u	*p;
6223     int		len;
6224 
6225     for (p = *arg; vim_isIDc(*p); ++p)
6226 	;
6227     if (p == *arg)	    /* no name found */
6228 	return 0;
6229 
6230     len = (int)(p - *arg);
6231     *arg = p;
6232     return len;
6233 }
6234 
6235 /*
6236  * Get the length of the name of a function or internal variable.
6237  * "arg" is advanced to the first non-white character after the name.
6238  * Return 0 if something is wrong.
6239  */
6240     int
6241 get_id_len(char_u **arg)
6242 {
6243     char_u	*p;
6244     int		len;
6245 
6246     /* Find the end of the name. */
6247     for (p = *arg; eval_isnamec(*p); ++p)
6248     {
6249 	if (*p == ':')
6250 	{
6251 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6252 	     * slice "[n:]".  Also "xx:" is not a namespace. */
6253 	    len = (int)(p - *arg);
6254 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
6255 		    || len > 1)
6256 		break;
6257 	}
6258     }
6259     if (p == *arg)	    /* no name found */
6260 	return 0;
6261 
6262     len = (int)(p - *arg);
6263     *arg = skipwhite(p);
6264 
6265     return len;
6266 }
6267 
6268 /*
6269  * Get the length of the name of a variable or function.
6270  * Only the name is recognized, does not handle ".key" or "[idx]".
6271  * "arg" is advanced to the first non-white character after the name.
6272  * Return -1 if curly braces expansion failed.
6273  * Return 0 if something else is wrong.
6274  * If the name contains 'magic' {}'s, expand them and return the
6275  * expanded name in an allocated string via 'alias' - caller must free.
6276  */
6277     int
6278 get_name_len(
6279     char_u	**arg,
6280     char_u	**alias,
6281     int		evaluate,
6282     int		verbose)
6283 {
6284     int		len;
6285     char_u	*p;
6286     char_u	*expr_start;
6287     char_u	*expr_end;
6288 
6289     *alias = NULL;  /* default to no alias */
6290 
6291     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
6292 						  && (*arg)[2] == (int)KE_SNR)
6293     {
6294 	/* hard coded <SNR>, already translated */
6295 	*arg += 3;
6296 	return get_id_len(arg) + 3;
6297     }
6298     len = eval_fname_script(*arg);
6299     if (len > 0)
6300     {
6301 	/* literal "<SID>", "s:" or "<SNR>" */
6302 	*arg += len;
6303     }
6304 
6305     /*
6306      * Find the end of the name; check for {} construction.
6307      */
6308     p = find_name_end(*arg, &expr_start, &expr_end,
6309 					       len > 0 ? 0 : FNE_CHECK_START);
6310     if (expr_start != NULL)
6311     {
6312 	char_u	*temp_string;
6313 
6314 	if (!evaluate)
6315 	{
6316 	    len += (int)(p - *arg);
6317 	    *arg = skipwhite(p);
6318 	    return len;
6319 	}
6320 
6321 	/*
6322 	 * Include any <SID> etc in the expanded string:
6323 	 * Thus the -len here.
6324 	 */
6325 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
6326 	if (temp_string == NULL)
6327 	    return -1;
6328 	*alias = temp_string;
6329 	*arg = skipwhite(p);
6330 	return (int)STRLEN(temp_string);
6331     }
6332 
6333     len += get_id_len(arg);
6334     if (len == 0 && verbose)
6335 	EMSG2(_(e_invexpr2), *arg);
6336 
6337     return len;
6338 }
6339 
6340 /*
6341  * Find the end of a variable or function name, taking care of magic braces.
6342  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
6343  * start and end of the first magic braces item.
6344  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
6345  * Return a pointer to just after the name.  Equal to "arg" if there is no
6346  * valid name.
6347  */
6348     char_u *
6349 find_name_end(
6350     char_u	*arg,
6351     char_u	**expr_start,
6352     char_u	**expr_end,
6353     int		flags)
6354 {
6355     int		mb_nest = 0;
6356     int		br_nest = 0;
6357     char_u	*p;
6358     int		len;
6359 
6360     if (expr_start != NULL)
6361     {
6362 	*expr_start = NULL;
6363 	*expr_end = NULL;
6364     }
6365 
6366     /* Quick check for valid starting character. */
6367     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg) && *arg != '{')
6368 	return arg;
6369 
6370     for (p = arg; *p != NUL
6371 		    && (eval_isnamec(*p)
6372 			|| *p == '{'
6373 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
6374 			|| mb_nest != 0
6375 			|| br_nest != 0); MB_PTR_ADV(p))
6376     {
6377 	if (*p == '\'')
6378 	{
6379 	    /* skip over 'string' to avoid counting [ and ] inside it. */
6380 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
6381 		;
6382 	    if (*p == NUL)
6383 		break;
6384 	}
6385 	else if (*p == '"')
6386 	{
6387 	    /* skip over "str\"ing" to avoid counting [ and ] inside it. */
6388 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
6389 		if (*p == '\\' && p[1] != NUL)
6390 		    ++p;
6391 	    if (*p == NUL)
6392 		break;
6393 	}
6394 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
6395 	{
6396 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6397 	     * slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is. */
6398 	    len = (int)(p - arg);
6399 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
6400 		    || (len > 1 && p[-1] != '}'))
6401 		break;
6402 	}
6403 
6404 	if (mb_nest == 0)
6405 	{
6406 	    if (*p == '[')
6407 		++br_nest;
6408 	    else if (*p == ']')
6409 		--br_nest;
6410 	}
6411 
6412 	if (br_nest == 0)
6413 	{
6414 	    if (*p == '{')
6415 	    {
6416 		mb_nest++;
6417 		if (expr_start != NULL && *expr_start == NULL)
6418 		    *expr_start = p;
6419 	    }
6420 	    else if (*p == '}')
6421 	    {
6422 		mb_nest--;
6423 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
6424 		    *expr_end = p;
6425 	    }
6426 	}
6427     }
6428 
6429     return p;
6430 }
6431 
6432 /*
6433  * Expands out the 'magic' {}'s in a variable/function name.
6434  * Note that this can call itself recursively, to deal with
6435  * constructs like foo{bar}{baz}{bam}
6436  * The four pointer arguments point to "foo{expre}ss{ion}bar"
6437  *			"in_start"      ^
6438  *			"expr_start"	   ^
6439  *			"expr_end"		 ^
6440  *			"in_end"			    ^
6441  *
6442  * Returns a new allocated string, which the caller must free.
6443  * Returns NULL for failure.
6444  */
6445     static char_u *
6446 make_expanded_name(
6447     char_u	*in_start,
6448     char_u	*expr_start,
6449     char_u	*expr_end,
6450     char_u	*in_end)
6451 {
6452     char_u	c1;
6453     char_u	*retval = NULL;
6454     char_u	*temp_result;
6455     char_u	*nextcmd = NULL;
6456 
6457     if (expr_end == NULL || in_end == NULL)
6458 	return NULL;
6459     *expr_start	= NUL;
6460     *expr_end = NUL;
6461     c1 = *in_end;
6462     *in_end = NUL;
6463 
6464     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
6465     if (temp_result != NULL && nextcmd == NULL)
6466     {
6467 	retval = alloc((unsigned)(STRLEN(temp_result) + (expr_start - in_start)
6468 						   + (in_end - expr_end) + 1));
6469 	if (retval != NULL)
6470 	{
6471 	    STRCPY(retval, in_start);
6472 	    STRCAT(retval, temp_result);
6473 	    STRCAT(retval, expr_end + 1);
6474 	}
6475     }
6476     vim_free(temp_result);
6477 
6478     *in_end = c1;		/* put char back for error messages */
6479     *expr_start = '{';
6480     *expr_end = '}';
6481 
6482     if (retval != NULL)
6483     {
6484 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
6485 	if (expr_start != NULL)
6486 	{
6487 	    /* Further expansion! */
6488 	    temp_result = make_expanded_name(retval, expr_start,
6489 						       expr_end, temp_result);
6490 	    vim_free(retval);
6491 	    retval = temp_result;
6492 	}
6493     }
6494 
6495     return retval;
6496 }
6497 
6498 /*
6499  * Return TRUE if character "c" can be used in a variable or function name.
6500  * Does not include '{' or '}' for magic braces.
6501  */
6502     int
6503 eval_isnamec(int c)
6504 {
6505     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
6506 }
6507 
6508 /*
6509  * Return TRUE if character "c" can be used as the first character in a
6510  * variable or function name (excluding '{' and '}').
6511  */
6512     int
6513 eval_isnamec1(int c)
6514 {
6515     return (ASCII_ISALPHA(c) || c == '_');
6516 }
6517 
6518 /*
6519  * Set number v: variable to "val".
6520  */
6521     void
6522 set_vim_var_nr(int idx, varnumber_T val)
6523 {
6524     vimvars[idx].vv_nr = val;
6525 }
6526 
6527 /*
6528  * Get number v: variable value.
6529  */
6530     varnumber_T
6531 get_vim_var_nr(int idx)
6532 {
6533     return vimvars[idx].vv_nr;
6534 }
6535 
6536 /*
6537  * Get string v: variable value.  Uses a static buffer, can only be used once.
6538  */
6539     char_u *
6540 get_vim_var_str(int idx)
6541 {
6542     return get_tv_string(&vimvars[idx].vv_tv);
6543 }
6544 
6545 /*
6546  * Get List v: variable value.  Caller must take care of reference count when
6547  * needed.
6548  */
6549     list_T *
6550 get_vim_var_list(int idx)
6551 {
6552     return vimvars[idx].vv_list;
6553 }
6554 
6555 /*
6556  * Set v:char to character "c".
6557  */
6558     void
6559 set_vim_var_char(int c)
6560 {
6561     char_u	buf[MB_MAXBYTES + 1];
6562 
6563 #ifdef FEAT_MBYTE
6564     if (has_mbyte)
6565 	buf[(*mb_char2bytes)(c, buf)] = NUL;
6566     else
6567 #endif
6568     {
6569 	buf[0] = c;
6570 	buf[1] = NUL;
6571     }
6572     set_vim_var_string(VV_CHAR, buf, -1);
6573 }
6574 
6575 /*
6576  * Set v:count to "count" and v:count1 to "count1".
6577  * When "set_prevcount" is TRUE first set v:prevcount from v:count.
6578  */
6579     void
6580 set_vcount(
6581     long	count,
6582     long	count1,
6583     int		set_prevcount)
6584 {
6585     if (set_prevcount)
6586 	vimvars[VV_PREVCOUNT].vv_nr = vimvars[VV_COUNT].vv_nr;
6587     vimvars[VV_COUNT].vv_nr = count;
6588     vimvars[VV_COUNT1].vv_nr = count1;
6589 }
6590 
6591 /*
6592  * Set string v: variable to a copy of "val".
6593  */
6594     void
6595 set_vim_var_string(
6596     int		idx,
6597     char_u	*val,
6598     int		len)	    /* length of "val" to use or -1 (whole string) */
6599 {
6600     clear_tv(&vimvars[idx].vv_di.di_tv);
6601     vimvars[idx].vv_type = VAR_STRING;
6602     if (val == NULL)
6603 	vimvars[idx].vv_str = NULL;
6604     else if (len == -1)
6605 	vimvars[idx].vv_str = vim_strsave(val);
6606     else
6607 	vimvars[idx].vv_str = vim_strnsave(val, len);
6608 }
6609 
6610 /*
6611  * Set List v: variable to "val".
6612  */
6613     void
6614 set_vim_var_list(int idx, list_T *val)
6615 {
6616     clear_tv(&vimvars[idx].vv_di.di_tv);
6617     vimvars[idx].vv_type = VAR_LIST;
6618     vimvars[idx].vv_list = val;
6619     if (val != NULL)
6620 	++val->lv_refcount;
6621 }
6622 
6623 /*
6624  * Set Dictionary v: variable to "val".
6625  */
6626     void
6627 set_vim_var_dict(int idx, dict_T *val)
6628 {
6629     int		todo;
6630     hashitem_T	*hi;
6631 
6632     clear_tv(&vimvars[idx].vv_di.di_tv);
6633     vimvars[idx].vv_type = VAR_DICT;
6634     vimvars[idx].vv_dict = val;
6635     if (val != NULL)
6636     {
6637 	++val->dv_refcount;
6638 
6639 	/* Set readonly */
6640 	todo = (int)val->dv_hashtab.ht_used;
6641 	for (hi = val->dv_hashtab.ht_array; todo > 0 ; ++hi)
6642 	{
6643 	    if (HASHITEM_EMPTY(hi))
6644 		continue;
6645 	    --todo;
6646 	    HI2DI(hi)->di_flags |= DI_FLAGS_RO | DI_FLAGS_FIX;
6647 	}
6648     }
6649 }
6650 
6651 /*
6652  * Set v:register if needed.
6653  */
6654     void
6655 set_reg_var(int c)
6656 {
6657     char_u	regname;
6658 
6659     if (c == 0 || c == ' ')
6660 	regname = '"';
6661     else
6662 	regname = c;
6663     /* Avoid free/alloc when the value is already right. */
6664     if (vimvars[VV_REG].vv_str == NULL || vimvars[VV_REG].vv_str[0] != c)
6665 	set_vim_var_string(VV_REG, &regname, 1);
6666 }
6667 
6668 /*
6669  * Get or set v:exception.  If "oldval" == NULL, return the current value.
6670  * Otherwise, restore the value to "oldval" and return NULL.
6671  * Must always be called in pairs to save and restore v:exception!  Does not
6672  * take care of memory allocations.
6673  */
6674     char_u *
6675 v_exception(char_u *oldval)
6676 {
6677     if (oldval == NULL)
6678 	return vimvars[VV_EXCEPTION].vv_str;
6679 
6680     vimvars[VV_EXCEPTION].vv_str = oldval;
6681     return NULL;
6682 }
6683 
6684 /*
6685  * Get or set v:throwpoint.  If "oldval" == NULL, return the current value.
6686  * Otherwise, restore the value to "oldval" and return NULL.
6687  * Must always be called in pairs to save and restore v:throwpoint!  Does not
6688  * take care of memory allocations.
6689  */
6690     char_u *
6691 v_throwpoint(char_u *oldval)
6692 {
6693     if (oldval == NULL)
6694 	return vimvars[VV_THROWPOINT].vv_str;
6695 
6696     vimvars[VV_THROWPOINT].vv_str = oldval;
6697     return NULL;
6698 }
6699 
6700 #if defined(FEAT_AUTOCMD) || defined(PROTO)
6701 /*
6702  * Set v:cmdarg.
6703  * If "eap" != NULL, use "eap" to generate the value and return the old value.
6704  * If "oldarg" != NULL, restore the value to "oldarg" and return NULL.
6705  * Must always be called in pairs!
6706  */
6707     char_u *
6708 set_cmdarg(exarg_T *eap, char_u *oldarg)
6709 {
6710     char_u	*oldval;
6711     char_u	*newval;
6712     unsigned	len;
6713 
6714     oldval = vimvars[VV_CMDARG].vv_str;
6715     if (eap == NULL)
6716     {
6717 	vim_free(oldval);
6718 	vimvars[VV_CMDARG].vv_str = oldarg;
6719 	return NULL;
6720     }
6721 
6722     if (eap->force_bin == FORCE_BIN)
6723 	len = 6;
6724     else if (eap->force_bin == FORCE_NOBIN)
6725 	len = 8;
6726     else
6727 	len = 0;
6728 
6729     if (eap->read_edit)
6730 	len += 7;
6731 
6732     if (eap->force_ff != 0)
6733 	len += (unsigned)STRLEN(eap->cmd + eap->force_ff) + 6;
6734 # ifdef FEAT_MBYTE
6735     if (eap->force_enc != 0)
6736 	len += (unsigned)STRLEN(eap->cmd + eap->force_enc) + 7;
6737     if (eap->bad_char != 0)
6738 	len += 7 + 4;  /* " ++bad=" + "keep" or "drop" */
6739 # endif
6740 
6741     newval = alloc(len + 1);
6742     if (newval == NULL)
6743 	return NULL;
6744 
6745     if (eap->force_bin == FORCE_BIN)
6746 	sprintf((char *)newval, " ++bin");
6747     else if (eap->force_bin == FORCE_NOBIN)
6748 	sprintf((char *)newval, " ++nobin");
6749     else
6750 	*newval = NUL;
6751 
6752     if (eap->read_edit)
6753 	STRCAT(newval, " ++edit");
6754 
6755     if (eap->force_ff != 0)
6756 	sprintf((char *)newval + STRLEN(newval), " ++ff=%s",
6757 						eap->cmd + eap->force_ff);
6758 # ifdef FEAT_MBYTE
6759     if (eap->force_enc != 0)
6760 	sprintf((char *)newval + STRLEN(newval), " ++enc=%s",
6761 					       eap->cmd + eap->force_enc);
6762     if (eap->bad_char == BAD_KEEP)
6763 	STRCPY(newval + STRLEN(newval), " ++bad=keep");
6764     else if (eap->bad_char == BAD_DROP)
6765 	STRCPY(newval + STRLEN(newval), " ++bad=drop");
6766     else if (eap->bad_char != 0)
6767 	sprintf((char *)newval + STRLEN(newval), " ++bad=%c", eap->bad_char);
6768 # endif
6769     vimvars[VV_CMDARG].vv_str = newval;
6770     return oldval;
6771 }
6772 #endif
6773 
6774 /*
6775  * Get the value of internal variable "name".
6776  * Return OK or FAIL.
6777  */
6778     int
6779 get_var_tv(
6780     char_u	*name,
6781     int		len,		/* length of "name" */
6782     typval_T	*rettv,		/* NULL when only checking existence */
6783     dictitem_T	**dip,		/* non-NULL when typval's dict item is needed */
6784     int		verbose,	/* may give error message */
6785     int		no_autoload)	/* do not use script autoloading */
6786 {
6787     int		ret = OK;
6788     typval_T	*tv = NULL;
6789     dictitem_T	*v;
6790     int		cc;
6791 
6792     /* truncate the name, so that we can use strcmp() */
6793     cc = name[len];
6794     name[len] = NUL;
6795 
6796     /*
6797      * Check for user-defined variables.
6798      */
6799     v = find_var(name, NULL, no_autoload);
6800     if (v != NULL)
6801     {
6802 	tv = &v->di_tv;
6803 	if (dip != NULL)
6804 	    *dip = v;
6805     }
6806 
6807     if (tv == NULL)
6808     {
6809 	if (rettv != NULL && verbose)
6810 	    EMSG2(_(e_undefvar), name);
6811 	ret = FAIL;
6812     }
6813     else if (rettv != NULL)
6814 	copy_tv(tv, rettv);
6815 
6816     name[len] = cc;
6817 
6818     return ret;
6819 }
6820 
6821 /*
6822  * Check if variable "name[len]" is a local variable or an argument.
6823  * If so, "*eval_lavars_used" is set to TRUE.
6824  */
6825     static void
6826 check_vars(char_u *name, int len)
6827 {
6828     int		cc;
6829     char_u	*varname;
6830     hashtab_T	*ht;
6831 
6832     if (eval_lavars_used == NULL)
6833 	return;
6834 
6835     /* truncate the name, so that we can use strcmp() */
6836     cc = name[len];
6837     name[len] = NUL;
6838 
6839     ht = find_var_ht(name, &varname);
6840     if (ht == get_funccal_local_ht() || ht == get_funccal_args_ht())
6841     {
6842 	if (find_var(name, NULL, TRUE) != NULL)
6843 	    *eval_lavars_used = TRUE;
6844     }
6845 
6846     name[len] = cc;
6847 }
6848 
6849 /*
6850  * Handle expr[expr], expr[expr:expr] subscript and .name lookup.
6851  * Also handle function call with Funcref variable: func(expr)
6852  * Can all be combined: dict.func(expr)[idx]['func'](expr)
6853  */
6854     int
6855 handle_subscript(
6856     char_u	**arg,
6857     typval_T	*rettv,
6858     int		evaluate,	/* do more than finding the end */
6859     int		verbose)	/* give error messages */
6860 {
6861     int		ret = OK;
6862     dict_T	*selfdict = NULL;
6863     char_u	*s;
6864     int		len;
6865     typval_T	functv;
6866 
6867     while (ret == OK
6868 	    && (**arg == '['
6869 		|| (**arg == '.' && rettv->v_type == VAR_DICT)
6870 		|| (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
6871 					    || rettv->v_type == VAR_PARTIAL)))
6872 	    && !VIM_ISWHITE(*(*arg - 1)))
6873     {
6874 	if (**arg == '(')
6875 	{
6876 	    partial_T	*pt = NULL;
6877 
6878 	    /* need to copy the funcref so that we can clear rettv */
6879 	    if (evaluate)
6880 	    {
6881 		functv = *rettv;
6882 		rettv->v_type = VAR_UNKNOWN;
6883 
6884 		/* Invoke the function.  Recursive! */
6885 		if (functv.v_type == VAR_PARTIAL)
6886 		{
6887 		    pt = functv.vval.v_partial;
6888 		    s = partial_name(pt);
6889 		}
6890 		else
6891 		    s = functv.vval.v_string;
6892 	    }
6893 	    else
6894 		s = (char_u *)"";
6895 	    ret = get_func_tv(s, (int)STRLEN(s), rettv, arg,
6896 			curwin->w_cursor.lnum, curwin->w_cursor.lnum,
6897 			&len, evaluate, pt, selfdict);
6898 
6899 	    /* Clear the funcref afterwards, so that deleting it while
6900 	     * evaluating the arguments is possible (see test55). */
6901 	    if (evaluate)
6902 		clear_tv(&functv);
6903 
6904 	    /* Stop the expression evaluation when immediately aborting on
6905 	     * error, or when an interrupt occurred or an exception was thrown
6906 	     * but not caught. */
6907 	    if (aborting())
6908 	    {
6909 		if (ret == OK)
6910 		    clear_tv(rettv);
6911 		ret = FAIL;
6912 	    }
6913 	    dict_unref(selfdict);
6914 	    selfdict = NULL;
6915 	}
6916 	else /* **arg == '[' || **arg == '.' */
6917 	{
6918 	    dict_unref(selfdict);
6919 	    if (rettv->v_type == VAR_DICT)
6920 	    {
6921 		selfdict = rettv->vval.v_dict;
6922 		if (selfdict != NULL)
6923 		    ++selfdict->dv_refcount;
6924 	    }
6925 	    else
6926 		selfdict = NULL;
6927 	    if (eval_index(arg, rettv, evaluate, verbose) == FAIL)
6928 	    {
6929 		clear_tv(rettv);
6930 		ret = FAIL;
6931 	    }
6932 	}
6933     }
6934 
6935     /* Turn "dict.Func" into a partial for "Func" bound to "dict".
6936      * Don't do this when "Func" is already a partial that was bound
6937      * explicitly (pt_auto is FALSE). */
6938     if (selfdict != NULL
6939 	    && (rettv->v_type == VAR_FUNC
6940 		|| (rettv->v_type == VAR_PARTIAL
6941 		    && (rettv->vval.v_partial->pt_auto
6942 			|| rettv->vval.v_partial->pt_dict == NULL))))
6943 	selfdict = make_partial(selfdict, rettv);
6944 
6945     dict_unref(selfdict);
6946     return ret;
6947 }
6948 
6949 /*
6950  * Allocate memory for a variable type-value, and make it empty (0 or NULL
6951  * value).
6952  */
6953     typval_T *
6954 alloc_tv(void)
6955 {
6956     return (typval_T *)alloc_clear((unsigned)sizeof(typval_T));
6957 }
6958 
6959 /*
6960  * Allocate memory for a variable type-value, and assign a string to it.
6961  * The string "s" must have been allocated, it is consumed.
6962  * Return NULL for out of memory, the variable otherwise.
6963  */
6964     static typval_T *
6965 alloc_string_tv(char_u *s)
6966 {
6967     typval_T	*rettv;
6968 
6969     rettv = alloc_tv();
6970     if (rettv != NULL)
6971     {
6972 	rettv->v_type = VAR_STRING;
6973 	rettv->vval.v_string = s;
6974     }
6975     else
6976 	vim_free(s);
6977     return rettv;
6978 }
6979 
6980 /*
6981  * Free the memory for a variable type-value.
6982  */
6983     void
6984 free_tv(typval_T *varp)
6985 {
6986     if (varp != NULL)
6987     {
6988 	switch (varp->v_type)
6989 	{
6990 	    case VAR_FUNC:
6991 		func_unref(varp->vval.v_string);
6992 		/*FALLTHROUGH*/
6993 	    case VAR_STRING:
6994 		vim_free(varp->vval.v_string);
6995 		break;
6996 	    case VAR_PARTIAL:
6997 		partial_unref(varp->vval.v_partial);
6998 		break;
6999 	    case VAR_LIST:
7000 		list_unref(varp->vval.v_list);
7001 		break;
7002 	    case VAR_DICT:
7003 		dict_unref(varp->vval.v_dict);
7004 		break;
7005 	    case VAR_JOB:
7006 #ifdef FEAT_JOB_CHANNEL
7007 		job_unref(varp->vval.v_job);
7008 		break;
7009 #endif
7010 	    case VAR_CHANNEL:
7011 #ifdef FEAT_JOB_CHANNEL
7012 		channel_unref(varp->vval.v_channel);
7013 		break;
7014 #endif
7015 	    case VAR_NUMBER:
7016 	    case VAR_FLOAT:
7017 	    case VAR_UNKNOWN:
7018 	    case VAR_SPECIAL:
7019 		break;
7020 	}
7021 	vim_free(varp);
7022     }
7023 }
7024 
7025 /*
7026  * Free the memory for a variable value and set the value to NULL or 0.
7027  */
7028     void
7029 clear_tv(typval_T *varp)
7030 {
7031     if (varp != NULL)
7032     {
7033 	switch (varp->v_type)
7034 	{
7035 	    case VAR_FUNC:
7036 		func_unref(varp->vval.v_string);
7037 		/*FALLTHROUGH*/
7038 	    case VAR_STRING:
7039 		vim_free(varp->vval.v_string);
7040 		varp->vval.v_string = NULL;
7041 		break;
7042 	    case VAR_PARTIAL:
7043 		partial_unref(varp->vval.v_partial);
7044 		varp->vval.v_partial = NULL;
7045 		break;
7046 	    case VAR_LIST:
7047 		list_unref(varp->vval.v_list);
7048 		varp->vval.v_list = NULL;
7049 		break;
7050 	    case VAR_DICT:
7051 		dict_unref(varp->vval.v_dict);
7052 		varp->vval.v_dict = NULL;
7053 		break;
7054 	    case VAR_NUMBER:
7055 	    case VAR_SPECIAL:
7056 		varp->vval.v_number = 0;
7057 		break;
7058 	    case VAR_FLOAT:
7059 #ifdef FEAT_FLOAT
7060 		varp->vval.v_float = 0.0;
7061 		break;
7062 #endif
7063 	    case VAR_JOB:
7064 #ifdef FEAT_JOB_CHANNEL
7065 		job_unref(varp->vval.v_job);
7066 		varp->vval.v_job = NULL;
7067 #endif
7068 		break;
7069 	    case VAR_CHANNEL:
7070 #ifdef FEAT_JOB_CHANNEL
7071 		channel_unref(varp->vval.v_channel);
7072 		varp->vval.v_channel = NULL;
7073 #endif
7074 	    case VAR_UNKNOWN:
7075 		break;
7076 	}
7077 	varp->v_lock = 0;
7078     }
7079 }
7080 
7081 /*
7082  * Set the value of a variable to NULL without freeing items.
7083  */
7084     void
7085 init_tv(typval_T *varp)
7086 {
7087     if (varp != NULL)
7088 	vim_memset(varp, 0, sizeof(typval_T));
7089 }
7090 
7091 /*
7092  * Get the number value of a variable.
7093  * If it is a String variable, uses vim_str2nr().
7094  * For incompatible types, return 0.
7095  * get_tv_number_chk() is similar to get_tv_number(), but informs the
7096  * caller of incompatible types: it sets *denote to TRUE if "denote"
7097  * is not NULL or returns -1 otherwise.
7098  */
7099     varnumber_T
7100 get_tv_number(typval_T *varp)
7101 {
7102     int		error = FALSE;
7103 
7104     return get_tv_number_chk(varp, &error);	/* return 0L on error */
7105 }
7106 
7107     varnumber_T
7108 get_tv_number_chk(typval_T *varp, int *denote)
7109 {
7110     varnumber_T	n = 0L;
7111 
7112     switch (varp->v_type)
7113     {
7114 	case VAR_NUMBER:
7115 	    return varp->vval.v_number;
7116 	case VAR_FLOAT:
7117 #ifdef FEAT_FLOAT
7118 	    EMSG(_("E805: Using a Float as a Number"));
7119 	    break;
7120 #endif
7121 	case VAR_FUNC:
7122 	case VAR_PARTIAL:
7123 	    EMSG(_("E703: Using a Funcref as a Number"));
7124 	    break;
7125 	case VAR_STRING:
7126 	    if (varp->vval.v_string != NULL)
7127 		vim_str2nr(varp->vval.v_string, NULL, NULL,
7128 						    STR2NR_ALL, &n, NULL, 0);
7129 	    return n;
7130 	case VAR_LIST:
7131 	    EMSG(_("E745: Using a List as a Number"));
7132 	    break;
7133 	case VAR_DICT:
7134 	    EMSG(_("E728: Using a Dictionary as a Number"));
7135 	    break;
7136 	case VAR_SPECIAL:
7137 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
7138 	    break;
7139 	case VAR_JOB:
7140 #ifdef FEAT_JOB_CHANNEL
7141 	    EMSG(_("E910: Using a Job as a Number"));
7142 	    break;
7143 #endif
7144 	case VAR_CHANNEL:
7145 #ifdef FEAT_JOB_CHANNEL
7146 	    EMSG(_("E913: Using a Channel as a Number"));
7147 	    break;
7148 #endif
7149 	case VAR_UNKNOWN:
7150 	    internal_error("get_tv_number(UNKNOWN)");
7151 	    break;
7152     }
7153     if (denote == NULL)		/* useful for values that must be unsigned */
7154 	n = -1;
7155     else
7156 	*denote = TRUE;
7157     return n;
7158 }
7159 
7160 #ifdef FEAT_FLOAT
7161     float_T
7162 get_tv_float(typval_T *varp)
7163 {
7164     switch (varp->v_type)
7165     {
7166 	case VAR_NUMBER:
7167 	    return (float_T)(varp->vval.v_number);
7168 	case VAR_FLOAT:
7169 	    return varp->vval.v_float;
7170 	case VAR_FUNC:
7171 	case VAR_PARTIAL:
7172 	    EMSG(_("E891: Using a Funcref as a Float"));
7173 	    break;
7174 	case VAR_STRING:
7175 	    EMSG(_("E892: Using a String as a Float"));
7176 	    break;
7177 	case VAR_LIST:
7178 	    EMSG(_("E893: Using a List as a Float"));
7179 	    break;
7180 	case VAR_DICT:
7181 	    EMSG(_("E894: Using a Dictionary as a Float"));
7182 	    break;
7183 	case VAR_SPECIAL:
7184 	    EMSG(_("E907: Using a special value as a Float"));
7185 	    break;
7186 	case VAR_JOB:
7187 # ifdef FEAT_JOB_CHANNEL
7188 	    EMSG(_("E911: Using a Job as a Float"));
7189 	    break;
7190 # endif
7191 	case VAR_CHANNEL:
7192 # ifdef FEAT_JOB_CHANNEL
7193 	    EMSG(_("E914: Using a Channel as a Float"));
7194 	    break;
7195 # endif
7196 	case VAR_UNKNOWN:
7197 	    internal_error("get_tv_float(UNKNOWN)");
7198 	    break;
7199     }
7200     return 0;
7201 }
7202 #endif
7203 
7204 /*
7205  * Get the string value of a variable.
7206  * If it is a Number variable, the number is converted into a string.
7207  * get_tv_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7208  * get_tv_string_buf() uses a given buffer.
7209  * If the String variable has never been set, return an empty string.
7210  * Never returns NULL;
7211  * get_tv_string_chk() and get_tv_string_buf_chk() are similar, but return
7212  * NULL on error.
7213  */
7214     char_u *
7215 get_tv_string(typval_T *varp)
7216 {
7217     static char_u   mybuf[NUMBUFLEN];
7218 
7219     return get_tv_string_buf(varp, mybuf);
7220 }
7221 
7222     char_u *
7223 get_tv_string_buf(typval_T *varp, char_u *buf)
7224 {
7225     char_u	*res =  get_tv_string_buf_chk(varp, buf);
7226 
7227     return res != NULL ? res : (char_u *)"";
7228 }
7229 
7230 /*
7231  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7232  */
7233     char_u *
7234 get_tv_string_chk(typval_T *varp)
7235 {
7236     static char_u   mybuf[NUMBUFLEN];
7237 
7238     return get_tv_string_buf_chk(varp, mybuf);
7239 }
7240 
7241     char_u *
7242 get_tv_string_buf_chk(typval_T *varp, char_u *buf)
7243 {
7244     switch (varp->v_type)
7245     {
7246 	case VAR_NUMBER:
7247 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
7248 					    (varnumber_T)varp->vval.v_number);
7249 	    return buf;
7250 	case VAR_FUNC:
7251 	case VAR_PARTIAL:
7252 	    EMSG(_("E729: using Funcref as a String"));
7253 	    break;
7254 	case VAR_LIST:
7255 	    EMSG(_("E730: using List as a String"));
7256 	    break;
7257 	case VAR_DICT:
7258 	    EMSG(_("E731: using Dictionary as a String"));
7259 	    break;
7260 	case VAR_FLOAT:
7261 #ifdef FEAT_FLOAT
7262 	    EMSG(_(e_float_as_string));
7263 	    break;
7264 #endif
7265 	case VAR_STRING:
7266 	    if (varp->vval.v_string != NULL)
7267 		return varp->vval.v_string;
7268 	    return (char_u *)"";
7269 	case VAR_SPECIAL:
7270 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
7271 	    return buf;
7272 	case VAR_JOB:
7273 #ifdef FEAT_JOB_CHANNEL
7274 	    {
7275 		job_T *job = varp->vval.v_job;
7276 		char  *status;
7277 
7278 		if (job == NULL)
7279 		    return (char_u *)"no process";
7280 		status = job->jv_status == JOB_FAILED ? "fail"
7281 				: job->jv_status >= JOB_ENDED ? "dead"
7282 				: "run";
7283 # ifdef UNIX
7284 		vim_snprintf((char *)buf, NUMBUFLEN,
7285 			    "process %ld %s", (long)job->jv_pid, status);
7286 # elif defined(WIN32)
7287 		vim_snprintf((char *)buf, NUMBUFLEN,
7288 			    "process %ld %s",
7289 			    (long)job->jv_proc_info.dwProcessId,
7290 			    status);
7291 # else
7292 		/* fall-back */
7293 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
7294 # endif
7295 		return buf;
7296 	    }
7297 #endif
7298 	    break;
7299 	case VAR_CHANNEL:
7300 #ifdef FEAT_JOB_CHANNEL
7301 	    {
7302 		channel_T *channel = varp->vval.v_channel;
7303 		char      *status = channel_status(channel, -1);
7304 
7305 		if (channel == NULL)
7306 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
7307 		else
7308 		    vim_snprintf((char *)buf, NUMBUFLEN,
7309 				     "channel %d %s", channel->ch_id, status);
7310 		return buf;
7311 	    }
7312 #endif
7313 	    break;
7314 	case VAR_UNKNOWN:
7315 	    EMSG(_("E908: using an invalid value as a String"));
7316 	    break;
7317     }
7318     return NULL;
7319 }
7320 
7321 /*
7322  * Find variable "name" in the list of variables.
7323  * Return a pointer to it if found, NULL if not found.
7324  * Careful: "a:0" variables don't have a name.
7325  * When "htp" is not NULL we are writing to the variable, set "htp" to the
7326  * hashtab_T used.
7327  */
7328     dictitem_T *
7329 find_var(char_u *name, hashtab_T **htp, int no_autoload)
7330 {
7331     char_u	*varname;
7332     hashtab_T	*ht;
7333     dictitem_T	*ret = NULL;
7334 
7335     ht = find_var_ht(name, &varname);
7336     if (htp != NULL)
7337 	*htp = ht;
7338     if (ht == NULL)
7339 	return NULL;
7340     ret = find_var_in_ht(ht, *name, varname, no_autoload || htp != NULL);
7341     if (ret != NULL)
7342 	return ret;
7343 
7344     /* Search in parent scope for lambda */
7345     return find_var_in_scoped_ht(name, no_autoload || htp != NULL);
7346 }
7347 
7348 /*
7349  * Find variable "varname" in hashtab "ht" with name "htname".
7350  * Returns NULL if not found.
7351  */
7352     dictitem_T *
7353 find_var_in_ht(
7354     hashtab_T	*ht,
7355     int		htname,
7356     char_u	*varname,
7357     int		no_autoload)
7358 {
7359     hashitem_T	*hi;
7360 
7361     if (*varname == NUL)
7362     {
7363 	/* Must be something like "s:", otherwise "ht" would be NULL. */
7364 	switch (htname)
7365 	{
7366 	    case 's': return &SCRIPT_SV(current_SID)->sv_var;
7367 	    case 'g': return &globvars_var;
7368 	    case 'v': return &vimvars_var;
7369 	    case 'b': return &curbuf->b_bufvar;
7370 	    case 'w': return &curwin->w_winvar;
7371 #ifdef FEAT_WINDOWS
7372 	    case 't': return &curtab->tp_winvar;
7373 #endif
7374 	    case 'l': return get_funccal_local_var();
7375 	    case 'a': return get_funccal_args_var();
7376 	}
7377 	return NULL;
7378     }
7379 
7380     hi = hash_find(ht, varname);
7381     if (HASHITEM_EMPTY(hi))
7382     {
7383 	/* For global variables we may try auto-loading the script.  If it
7384 	 * worked find the variable again.  Don't auto-load a script if it was
7385 	 * loaded already, otherwise it would be loaded every time when
7386 	 * checking if a function name is a Funcref variable. */
7387 	if (ht == &globvarht && !no_autoload)
7388 	{
7389 	    /* Note: script_autoload() may make "hi" invalid. It must either
7390 	     * be obtained again or not used. */
7391 	    if (!script_autoload(varname, FALSE) || aborting())
7392 		return NULL;
7393 	    hi = hash_find(ht, varname);
7394 	}
7395 	if (HASHITEM_EMPTY(hi))
7396 	    return NULL;
7397     }
7398     return HI2DI(hi);
7399 }
7400 
7401 /*
7402  * Find the hashtab used for a variable name.
7403  * Return NULL if the name is not valid.
7404  * Set "varname" to the start of name without ':'.
7405  */
7406     hashtab_T *
7407 find_var_ht(char_u *name, char_u **varname)
7408 {
7409     hashitem_T	*hi;
7410     hashtab_T	*ht;
7411 
7412     if (name[0] == NUL)
7413 	return NULL;
7414     if (name[1] != ':')
7415     {
7416 	/* The name must not start with a colon or #. */
7417 	if (name[0] == ':' || name[0] == AUTOLOAD_CHAR)
7418 	    return NULL;
7419 	*varname = name;
7420 
7421 	/* "version" is "v:version" in all scopes */
7422 	hi = hash_find(&compat_hashtab, name);
7423 	if (!HASHITEM_EMPTY(hi))
7424 	    return &compat_hashtab;
7425 
7426 	ht = get_funccal_local_ht();
7427 	if (ht == NULL)
7428 	    return &globvarht;			/* global variable */
7429 	return ht;				/* local variable */
7430     }
7431     *varname = name + 2;
7432     if (*name == 'g')				/* global variable */
7433 	return &globvarht;
7434     /* There must be no ':' or '#' in the rest of the name, unless g: is used
7435      */
7436     if (vim_strchr(name + 2, ':') != NULL
7437 			       || vim_strchr(name + 2, AUTOLOAD_CHAR) != NULL)
7438 	return NULL;
7439     if (*name == 'b')				/* buffer variable */
7440 	return &curbuf->b_vars->dv_hashtab;
7441     if (*name == 'w')				/* window variable */
7442 	return &curwin->w_vars->dv_hashtab;
7443 #ifdef FEAT_WINDOWS
7444     if (*name == 't')				/* tab page variable */
7445 	return &curtab->tp_vars->dv_hashtab;
7446 #endif
7447     if (*name == 'v')				/* v: variable */
7448 	return &vimvarht;
7449     if (*name == 'a')				/* a: function argument */
7450 	return get_funccal_args_ht();
7451     if (*name == 'l')				/* l: local function variable */
7452 	return get_funccal_local_ht();
7453     if (*name == 's'				/* script variable */
7454 	    && current_SID > 0 && current_SID <= ga_scripts.ga_len)
7455 	return &SCRIPT_VARS(current_SID);
7456     return NULL;
7457 }
7458 
7459 /*
7460  * Get the string value of a (global/local) variable.
7461  * Note: see get_tv_string() for how long the pointer remains valid.
7462  * Returns NULL when it doesn't exist.
7463  */
7464     char_u *
7465 get_var_value(char_u *name)
7466 {
7467     dictitem_T	*v;
7468 
7469     v = find_var(name, NULL, FALSE);
7470     if (v == NULL)
7471 	return NULL;
7472     return get_tv_string(&v->di_tv);
7473 }
7474 
7475 /*
7476  * Allocate a new hashtab for a sourced script.  It will be used while
7477  * sourcing this script and when executing functions defined in the script.
7478  */
7479     void
7480 new_script_vars(scid_T id)
7481 {
7482     int		i;
7483     hashtab_T	*ht;
7484     scriptvar_T *sv;
7485 
7486     if (ga_grow(&ga_scripts, (int)(id - ga_scripts.ga_len)) == OK)
7487     {
7488 	/* Re-allocating ga_data means that an ht_array pointing to
7489 	 * ht_smallarray becomes invalid.  We can recognize this: ht_mask is
7490 	 * at its init value.  Also reset "v_dict", it's always the same. */
7491 	for (i = 1; i <= ga_scripts.ga_len; ++i)
7492 	{
7493 	    ht = &SCRIPT_VARS(i);
7494 	    if (ht->ht_mask == HT_INIT_SIZE - 1)
7495 		ht->ht_array = ht->ht_smallarray;
7496 	    sv = SCRIPT_SV(i);
7497 	    sv->sv_var.di_tv.vval.v_dict = &sv->sv_dict;
7498 	}
7499 
7500 	while (ga_scripts.ga_len < id)
7501 	{
7502 	    sv = SCRIPT_SV(ga_scripts.ga_len + 1) =
7503 		(scriptvar_T *)alloc_clear(sizeof(scriptvar_T));
7504 	    init_var_dict(&sv->sv_dict, &sv->sv_var, VAR_SCOPE);
7505 	    ++ga_scripts.ga_len;
7506 	}
7507     }
7508 }
7509 
7510 /*
7511  * Initialize dictionary "dict" as a scope and set variable "dict_var" to
7512  * point to it.
7513  */
7514     void
7515 init_var_dict(dict_T *dict, dictitem_T *dict_var, int scope)
7516 {
7517     hash_init(&dict->dv_hashtab);
7518     dict->dv_lock = 0;
7519     dict->dv_scope = scope;
7520     dict->dv_refcount = DO_NOT_FREE_CNT;
7521     dict->dv_copyID = 0;
7522     dict_var->di_tv.vval.v_dict = dict;
7523     dict_var->di_tv.v_type = VAR_DICT;
7524     dict_var->di_tv.v_lock = VAR_FIXED;
7525     dict_var->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
7526     dict_var->di_key[0] = NUL;
7527 }
7528 
7529 /*
7530  * Unreference a dictionary initialized by init_var_dict().
7531  */
7532     void
7533 unref_var_dict(dict_T *dict)
7534 {
7535     /* Now the dict needs to be freed if no one else is using it, go back to
7536      * normal reference counting. */
7537     dict->dv_refcount -= DO_NOT_FREE_CNT - 1;
7538     dict_unref(dict);
7539 }
7540 
7541 /*
7542  * Clean up a list of internal variables.
7543  * Frees all allocated variables and the value they contain.
7544  * Clears hashtab "ht", does not free it.
7545  */
7546     void
7547 vars_clear(hashtab_T *ht)
7548 {
7549     vars_clear_ext(ht, TRUE);
7550 }
7551 
7552 /*
7553  * Like vars_clear(), but only free the value if "free_val" is TRUE.
7554  */
7555     void
7556 vars_clear_ext(hashtab_T *ht, int free_val)
7557 {
7558     int		todo;
7559     hashitem_T	*hi;
7560     dictitem_T	*v;
7561 
7562     hash_lock(ht);
7563     todo = (int)ht->ht_used;
7564     for (hi = ht->ht_array; todo > 0; ++hi)
7565     {
7566 	if (!HASHITEM_EMPTY(hi))
7567 	{
7568 	    --todo;
7569 
7570 	    /* Free the variable.  Don't remove it from the hashtab,
7571 	     * ht_array might change then.  hash_clear() takes care of it
7572 	     * later. */
7573 	    v = HI2DI(hi);
7574 	    if (free_val)
7575 		clear_tv(&v->di_tv);
7576 	    if (v->di_flags & DI_FLAGS_ALLOC)
7577 		vim_free(v);
7578 	}
7579     }
7580     hash_clear(ht);
7581     ht->ht_used = 0;
7582 }
7583 
7584 /*
7585  * Delete a variable from hashtab "ht" at item "hi".
7586  * Clear the variable value and free the dictitem.
7587  */
7588     static void
7589 delete_var(hashtab_T *ht, hashitem_T *hi)
7590 {
7591     dictitem_T	*di = HI2DI(hi);
7592 
7593     hash_remove(ht, hi);
7594     clear_tv(&di->di_tv);
7595     vim_free(di);
7596 }
7597 
7598 /*
7599  * List the value of one internal variable.
7600  */
7601     static void
7602 list_one_var(dictitem_T *v, char_u *prefix, int *first)
7603 {
7604     char_u	*tofree;
7605     char_u	*s;
7606     char_u	numbuf[NUMBUFLEN];
7607 
7608     s = echo_string(&v->di_tv, &tofree, numbuf, get_copyID());
7609     list_one_var_a(prefix, v->di_key, v->di_tv.v_type,
7610 					 s == NULL ? (char_u *)"" : s, first);
7611     vim_free(tofree);
7612 }
7613 
7614     static void
7615 list_one_var_a(
7616     char_u	*prefix,
7617     char_u	*name,
7618     int		type,
7619     char_u	*string,
7620     int		*first)  /* when TRUE clear rest of screen and set to FALSE */
7621 {
7622     /* don't use msg() or msg_attr() to avoid overwriting "v:statusmsg" */
7623     msg_start();
7624     msg_puts(prefix);
7625     if (name != NULL)	/* "a:" vars don't have a name stored */
7626 	msg_puts(name);
7627     msg_putchar(' ');
7628     msg_advance(22);
7629     if (type == VAR_NUMBER)
7630 	msg_putchar('#');
7631     else if (type == VAR_FUNC || type == VAR_PARTIAL)
7632 	msg_putchar('*');
7633     else if (type == VAR_LIST)
7634     {
7635 	msg_putchar('[');
7636 	if (*string == '[')
7637 	    ++string;
7638     }
7639     else if (type == VAR_DICT)
7640     {
7641 	msg_putchar('{');
7642 	if (*string == '{')
7643 	    ++string;
7644     }
7645     else
7646 	msg_putchar(' ');
7647 
7648     msg_outtrans(string);
7649 
7650     if (type == VAR_FUNC || type == VAR_PARTIAL)
7651 	msg_puts((char_u *)"()");
7652     if (*first)
7653     {
7654 	msg_clr_eos();
7655 	*first = FALSE;
7656     }
7657 }
7658 
7659 /*
7660  * Set variable "name" to value in "tv".
7661  * If the variable already exists, the value is updated.
7662  * Otherwise the variable is created.
7663  */
7664     void
7665 set_var(
7666     char_u	*name,
7667     typval_T	*tv,
7668     int		copy)	    /* make copy of value in "tv" */
7669 {
7670     dictitem_T	*v;
7671     char_u	*varname;
7672     hashtab_T	*ht;
7673 
7674     ht = find_var_ht(name, &varname);
7675     if (ht == NULL || *varname == NUL)
7676     {
7677 	EMSG2(_(e_illvar), name);
7678 	return;
7679     }
7680     v = find_var_in_ht(ht, 0, varname, TRUE);
7681 
7682     /* Search in parent scope which is possible to reference from lambda */
7683     if (v == NULL)
7684 	v = find_var_in_scoped_ht(name, TRUE);
7685 
7686     if ((tv->v_type == VAR_FUNC || tv->v_type == VAR_PARTIAL)
7687 				      && var_check_func_name(name, v == NULL))
7688 	return;
7689 
7690     if (v != NULL)
7691     {
7692 	/* existing variable, need to clear the value */
7693 	if (var_check_ro(v->di_flags, name, FALSE)
7694 			       || tv_check_lock(v->di_tv.v_lock, name, FALSE))
7695 	    return;
7696 
7697 	/*
7698 	 * Handle setting internal v: variables separately where needed to
7699 	 * prevent changing the type.
7700 	 */
7701 	if (ht == &vimvarht)
7702 	{
7703 	    if (v->di_tv.v_type == VAR_STRING)
7704 	    {
7705 		vim_free(v->di_tv.vval.v_string);
7706 		if (copy || tv->v_type != VAR_STRING)
7707 		    v->di_tv.vval.v_string = vim_strsave(get_tv_string(tv));
7708 		else
7709 		{
7710 		    /* Take over the string to avoid an extra alloc/free. */
7711 		    v->di_tv.vval.v_string = tv->vval.v_string;
7712 		    tv->vval.v_string = NULL;
7713 		}
7714 		return;
7715 	    }
7716 	    else if (v->di_tv.v_type == VAR_NUMBER)
7717 	    {
7718 		v->di_tv.vval.v_number = get_tv_number(tv);
7719 		if (STRCMP(varname, "searchforward") == 0)
7720 		    set_search_direction(v->di_tv.vval.v_number ? '/' : '?');
7721 #ifdef FEAT_SEARCH_EXTRA
7722 		else if (STRCMP(varname, "hlsearch") == 0)
7723 		{
7724 		    no_hlsearch = !v->di_tv.vval.v_number;
7725 		    redraw_all_later(SOME_VALID);
7726 		}
7727 #endif
7728 		return;
7729 	    }
7730 	    else if (v->di_tv.v_type != tv->v_type)
7731 		internal_error("set_var()");
7732 	}
7733 
7734 	clear_tv(&v->di_tv);
7735     }
7736     else		    /* add a new variable */
7737     {
7738 	/* Can't add "v:" variable. */
7739 	if (ht == &vimvarht)
7740 	{
7741 	    EMSG2(_(e_illvar), name);
7742 	    return;
7743 	}
7744 
7745 	/* Make sure the variable name is valid. */
7746 	if (!valid_varname(varname))
7747 	    return;
7748 
7749 	v = (dictitem_T *)alloc((unsigned)(sizeof(dictitem_T)
7750 							  + STRLEN(varname)));
7751 	if (v == NULL)
7752 	    return;
7753 	STRCPY(v->di_key, varname);
7754 	if (hash_add(ht, DI2HIKEY(v)) == FAIL)
7755 	{
7756 	    vim_free(v);
7757 	    return;
7758 	}
7759 	v->di_flags = DI_FLAGS_ALLOC;
7760     }
7761 
7762     if (copy || tv->v_type == VAR_NUMBER || tv->v_type == VAR_FLOAT)
7763 	copy_tv(tv, &v->di_tv);
7764     else
7765     {
7766 	v->di_tv = *tv;
7767 	v->di_tv.v_lock = 0;
7768 	init_tv(tv);
7769     }
7770 }
7771 
7772 /*
7773  * Return TRUE if di_flags "flags" indicates variable "name" is read-only.
7774  * Also give an error message.
7775  */
7776     int
7777 var_check_ro(int flags, char_u *name, int use_gettext)
7778 {
7779     if (flags & DI_FLAGS_RO)
7780     {
7781 	EMSG2(_(e_readonlyvar), use_gettext ? (char_u *)_(name) : name);
7782 	return TRUE;
7783     }
7784     if ((flags & DI_FLAGS_RO_SBX) && sandbox)
7785     {
7786 	EMSG2(_(e_readonlysbx), use_gettext ? (char_u *)_(name) : name);
7787 	return TRUE;
7788     }
7789     return FALSE;
7790 }
7791 
7792 /*
7793  * Return TRUE if di_flags "flags" indicates variable "name" is fixed.
7794  * Also give an error message.
7795  */
7796     int
7797 var_check_fixed(int flags, char_u *name, int use_gettext)
7798 {
7799     if (flags & DI_FLAGS_FIX)
7800     {
7801 	EMSG2(_("E795: Cannot delete variable %s"),
7802 				      use_gettext ? (char_u *)_(name) : name);
7803 	return TRUE;
7804     }
7805     return FALSE;
7806 }
7807 
7808 /*
7809  * Check if a funcref is assigned to a valid variable name.
7810  * Return TRUE and give an error if not.
7811  */
7812     int
7813 var_check_func_name(
7814     char_u *name,    /* points to start of variable name */
7815     int    new_var)  /* TRUE when creating the variable */
7816 {
7817     /* Allow for w: b: s: and t:. */
7818     if (!(vim_strchr((char_u *)"wbst", name[0]) != NULL && name[1] == ':')
7819 	    && !ASCII_ISUPPER((name[0] != NUL && name[1] == ':')
7820 						     ? name[2] : name[0]))
7821     {
7822 	EMSG2(_("E704: Funcref variable name must start with a capital: %s"),
7823 									name);
7824 	return TRUE;
7825     }
7826     /* Don't allow hiding a function.  When "v" is not NULL we might be
7827      * assigning another function to the same var, the type is checked
7828      * below. */
7829     if (new_var && function_exists(name, FALSE))
7830     {
7831 	EMSG2(_("E705: Variable name conflicts with existing function: %s"),
7832 								    name);
7833 	return TRUE;
7834     }
7835     return FALSE;
7836 }
7837 
7838 /*
7839  * Check if a variable name is valid.
7840  * Return FALSE and give an error if not.
7841  */
7842     int
7843 valid_varname(char_u *varname)
7844 {
7845     char_u *p;
7846 
7847     for (p = varname; *p != NUL; ++p)
7848 	if (!eval_isnamec1(*p) && (p == varname || !VIM_ISDIGIT(*p))
7849 						   && *p != AUTOLOAD_CHAR)
7850 	{
7851 	    EMSG2(_(e_illvar), varname);
7852 	    return FALSE;
7853 	}
7854     return TRUE;
7855 }
7856 
7857 /*
7858  * Return TRUE if typeval "tv" is set to be locked (immutable).
7859  * Also give an error message, using "name" or _("name") when use_gettext is
7860  * TRUE.
7861  */
7862     int
7863 tv_check_lock(int lock, char_u *name, int use_gettext)
7864 {
7865     if (lock & VAR_LOCKED)
7866     {
7867 	EMSG2(_("E741: Value is locked: %s"),
7868 				name == NULL ? (char_u *)_("Unknown")
7869 					     : use_gettext ? (char_u *)_(name)
7870 					     : name);
7871 	return TRUE;
7872     }
7873     if (lock & VAR_FIXED)
7874     {
7875 	EMSG2(_("E742: Cannot change value of %s"),
7876 				name == NULL ? (char_u *)_("Unknown")
7877 					     : use_gettext ? (char_u *)_(name)
7878 					     : name);
7879 	return TRUE;
7880     }
7881     return FALSE;
7882 }
7883 
7884 /*
7885  * Copy the values from typval_T "from" to typval_T "to".
7886  * When needed allocates string or increases reference count.
7887  * Does not make a copy of a list or dict but copies the reference!
7888  * It is OK for "from" and "to" to point to the same item.  This is used to
7889  * make a copy later.
7890  */
7891     void
7892 copy_tv(typval_T *from, typval_T *to)
7893 {
7894     to->v_type = from->v_type;
7895     to->v_lock = 0;
7896     switch (from->v_type)
7897     {
7898 	case VAR_NUMBER:
7899 	case VAR_SPECIAL:
7900 	    to->vval.v_number = from->vval.v_number;
7901 	    break;
7902 	case VAR_FLOAT:
7903 #ifdef FEAT_FLOAT
7904 	    to->vval.v_float = from->vval.v_float;
7905 	    break;
7906 #endif
7907 	case VAR_JOB:
7908 #ifdef FEAT_JOB_CHANNEL
7909 	    to->vval.v_job = from->vval.v_job;
7910 	    if (to->vval.v_job != NULL)
7911 		++to->vval.v_job->jv_refcount;
7912 	    break;
7913 #endif
7914 	case VAR_CHANNEL:
7915 #ifdef FEAT_JOB_CHANNEL
7916 	    to->vval.v_channel = from->vval.v_channel;
7917 	    if (to->vval.v_channel != NULL)
7918 		++to->vval.v_channel->ch_refcount;
7919 	    break;
7920 #endif
7921 	case VAR_STRING:
7922 	case VAR_FUNC:
7923 	    if (from->vval.v_string == NULL)
7924 		to->vval.v_string = NULL;
7925 	    else
7926 	    {
7927 		to->vval.v_string = vim_strsave(from->vval.v_string);
7928 		if (from->v_type == VAR_FUNC)
7929 		    func_ref(to->vval.v_string);
7930 	    }
7931 	    break;
7932 	case VAR_PARTIAL:
7933 	    if (from->vval.v_partial == NULL)
7934 		to->vval.v_partial = NULL;
7935 	    else
7936 	    {
7937 		to->vval.v_partial = from->vval.v_partial;
7938 		++to->vval.v_partial->pt_refcount;
7939 	    }
7940 	    break;
7941 	case VAR_LIST:
7942 	    if (from->vval.v_list == NULL)
7943 		to->vval.v_list = NULL;
7944 	    else
7945 	    {
7946 		to->vval.v_list = from->vval.v_list;
7947 		++to->vval.v_list->lv_refcount;
7948 	    }
7949 	    break;
7950 	case VAR_DICT:
7951 	    if (from->vval.v_dict == NULL)
7952 		to->vval.v_dict = NULL;
7953 	    else
7954 	    {
7955 		to->vval.v_dict = from->vval.v_dict;
7956 		++to->vval.v_dict->dv_refcount;
7957 	    }
7958 	    break;
7959 	case VAR_UNKNOWN:
7960 	    internal_error("copy_tv(UNKNOWN)");
7961 	    break;
7962     }
7963 }
7964 
7965 /*
7966  * Make a copy of an item.
7967  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
7968  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
7969  * reference to an already copied list/dict can be used.
7970  * Returns FAIL or OK.
7971  */
7972     int
7973 item_copy(
7974     typval_T	*from,
7975     typval_T	*to,
7976     int		deep,
7977     int		copyID)
7978 {
7979     static int	recurse = 0;
7980     int		ret = OK;
7981 
7982     if (recurse >= DICT_MAXNEST)
7983     {
7984 	EMSG(_("E698: variable nested too deep for making a copy"));
7985 	return FAIL;
7986     }
7987     ++recurse;
7988 
7989     switch (from->v_type)
7990     {
7991 	case VAR_NUMBER:
7992 	case VAR_FLOAT:
7993 	case VAR_STRING:
7994 	case VAR_FUNC:
7995 	case VAR_PARTIAL:
7996 	case VAR_SPECIAL:
7997 	case VAR_JOB:
7998 	case VAR_CHANNEL:
7999 	    copy_tv(from, to);
8000 	    break;
8001 	case VAR_LIST:
8002 	    to->v_type = VAR_LIST;
8003 	    to->v_lock = 0;
8004 	    if (from->vval.v_list == NULL)
8005 		to->vval.v_list = NULL;
8006 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
8007 	    {
8008 		/* use the copy made earlier */
8009 		to->vval.v_list = from->vval.v_list->lv_copylist;
8010 		++to->vval.v_list->lv_refcount;
8011 	    }
8012 	    else
8013 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
8014 	    if (to->vval.v_list == NULL)
8015 		ret = FAIL;
8016 	    break;
8017 	case VAR_DICT:
8018 	    to->v_type = VAR_DICT;
8019 	    to->v_lock = 0;
8020 	    if (from->vval.v_dict == NULL)
8021 		to->vval.v_dict = NULL;
8022 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
8023 	    {
8024 		/* use the copy made earlier */
8025 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
8026 		++to->vval.v_dict->dv_refcount;
8027 	    }
8028 	    else
8029 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
8030 	    if (to->vval.v_dict == NULL)
8031 		ret = FAIL;
8032 	    break;
8033 	case VAR_UNKNOWN:
8034 	    internal_error("item_copy(UNKNOWN)");
8035 	    ret = FAIL;
8036     }
8037     --recurse;
8038     return ret;
8039 }
8040 
8041 /*
8042  * This function is used by f_input() and f_inputdialog() functions. The third
8043  * argument to f_input() specifies the type of completion to use at the
8044  * prompt. The third argument to f_inputdialog() specifies the value to return
8045  * when the user cancels the prompt.
8046  */
8047     void
8048 get_user_input(
8049     typval_T	*argvars,
8050     typval_T	*rettv,
8051     int		inputdialog,
8052     int		secret)
8053 {
8054     char_u	*prompt = get_tv_string_chk(&argvars[0]);
8055     char_u	*p = NULL;
8056     int		c;
8057     char_u	buf[NUMBUFLEN];
8058     int		cmd_silent_save = cmd_silent;
8059     char_u	*defstr = (char_u *)"";
8060     int		xp_type = EXPAND_NOTHING;
8061     char_u	*xp_arg = NULL;
8062 
8063     rettv->v_type = VAR_STRING;
8064     rettv->vval.v_string = NULL;
8065 
8066 #ifdef NO_CONSOLE_INPUT
8067     /* While starting up, there is no place to enter text. */
8068     if (no_console_input())
8069 	return;
8070 #endif
8071 
8072     cmd_silent = FALSE;		/* Want to see the prompt. */
8073     if (prompt != NULL)
8074     {
8075 	/* Only the part of the message after the last NL is considered as
8076 	 * prompt for the command line */
8077 	p = vim_strrchr(prompt, '\n');
8078 	if (p == NULL)
8079 	    p = prompt;
8080 	else
8081 	{
8082 	    ++p;
8083 	    c = *p;
8084 	    *p = NUL;
8085 	    msg_start();
8086 	    msg_clr_eos();
8087 	    msg_puts_attr(prompt, echo_attr);
8088 	    msg_didout = FALSE;
8089 	    msg_starthere();
8090 	    *p = c;
8091 	}
8092 	cmdline_row = msg_row;
8093 
8094 	if (argvars[1].v_type != VAR_UNKNOWN)
8095 	{
8096 	    defstr = get_tv_string_buf_chk(&argvars[1], buf);
8097 	    if (defstr != NULL)
8098 		stuffReadbuffSpec(defstr);
8099 
8100 	    if (!inputdialog && argvars[2].v_type != VAR_UNKNOWN)
8101 	    {
8102 		char_u	*xp_name;
8103 		int	xp_namelen;
8104 		long	argt;
8105 
8106 		/* input() with a third argument: completion */
8107 		rettv->vval.v_string = NULL;
8108 
8109 		xp_name = get_tv_string_buf_chk(&argvars[2], buf);
8110 		if (xp_name == NULL)
8111 		    return;
8112 
8113 		xp_namelen = (int)STRLEN(xp_name);
8114 
8115 		if (parse_compl_arg(xp_name, xp_namelen, &xp_type, &argt,
8116 							     &xp_arg) == FAIL)
8117 		    return;
8118 	    }
8119 	}
8120 
8121 	if (defstr != NULL)
8122 	{
8123 	    int save_ex_normal_busy = ex_normal_busy;
8124 	    ex_normal_busy = 0;
8125 	    rettv->vval.v_string =
8126 		getcmdline_prompt(secret ? NUL : '@', p, echo_attr,
8127 							      xp_type, xp_arg);
8128 	    ex_normal_busy = save_ex_normal_busy;
8129 	}
8130 	if (inputdialog && rettv->vval.v_string == NULL
8131 		&& argvars[1].v_type != VAR_UNKNOWN
8132 		&& argvars[2].v_type != VAR_UNKNOWN)
8133 	    rettv->vval.v_string = vim_strsave(get_tv_string_buf(
8134 							   &argvars[2], buf));
8135 
8136 	vim_free(xp_arg);
8137 
8138 	/* since the user typed this, no need to wait for return */
8139 	need_wait_return = FALSE;
8140 	msg_didout = FALSE;
8141     }
8142     cmd_silent = cmd_silent_save;
8143 }
8144 
8145 /*
8146  * ":echo expr1 ..."	print each argument separated with a space, add a
8147  *			newline at the end.
8148  * ":echon expr1 ..."	print each argument plain.
8149  */
8150     void
8151 ex_echo(exarg_T *eap)
8152 {
8153     char_u	*arg = eap->arg;
8154     typval_T	rettv;
8155     char_u	*tofree;
8156     char_u	*p;
8157     int		needclr = TRUE;
8158     int		atstart = TRUE;
8159     char_u	numbuf[NUMBUFLEN];
8160 
8161     if (eap->skip)
8162 	++emsg_skip;
8163     while (*arg != NUL && *arg != '|' && *arg != '\n' && !got_int)
8164     {
8165 	/* If eval1() causes an error message the text from the command may
8166 	 * still need to be cleared. E.g., "echo 22,44". */
8167 	need_clr_eos = needclr;
8168 
8169 	p = arg;
8170 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8171 	{
8172 	    /*
8173 	     * Report the invalid expression unless the expression evaluation
8174 	     * has been cancelled due to an aborting error, an interrupt, or an
8175 	     * exception.
8176 	     */
8177 	    if (!aborting())
8178 		EMSG2(_(e_invexpr2), p);
8179 	    need_clr_eos = FALSE;
8180 	    break;
8181 	}
8182 	need_clr_eos = FALSE;
8183 
8184 	if (!eap->skip)
8185 	{
8186 	    if (atstart)
8187 	    {
8188 		atstart = FALSE;
8189 		/* Call msg_start() after eval1(), evaluating the expression
8190 		 * may cause a message to appear. */
8191 		if (eap->cmdidx == CMD_echo)
8192 		{
8193 		    /* Mark the saved text as finishing the line, so that what
8194 		     * follows is displayed on a new line when scrolling back
8195 		     * at the more prompt. */
8196 		    msg_sb_eol();
8197 		    msg_start();
8198 		}
8199 	    }
8200 	    else if (eap->cmdidx == CMD_echo)
8201 		msg_puts_attr((char_u *)" ", echo_attr);
8202 	    p = echo_string(&rettv, &tofree, numbuf, get_copyID());
8203 	    if (p != NULL)
8204 		for ( ; *p != NUL && !got_int; ++p)
8205 		{
8206 		    if (*p == '\n' || *p == '\r' || *p == TAB)
8207 		    {
8208 			if (*p != TAB && needclr)
8209 			{
8210 			    /* remove any text still there from the command */
8211 			    msg_clr_eos();
8212 			    needclr = FALSE;
8213 			}
8214 			msg_putchar_attr(*p, echo_attr);
8215 		    }
8216 		    else
8217 		    {
8218 #ifdef FEAT_MBYTE
8219 			if (has_mbyte)
8220 			{
8221 			    int i = (*mb_ptr2len)(p);
8222 
8223 			    (void)msg_outtrans_len_attr(p, i, echo_attr);
8224 			    p += i - 1;
8225 			}
8226 			else
8227 #endif
8228 			    (void)msg_outtrans_len_attr(p, 1, echo_attr);
8229 		    }
8230 		}
8231 	    vim_free(tofree);
8232 	}
8233 	clear_tv(&rettv);
8234 	arg = skipwhite(arg);
8235     }
8236     eap->nextcmd = check_nextcmd(arg);
8237 
8238     if (eap->skip)
8239 	--emsg_skip;
8240     else
8241     {
8242 	/* remove text that may still be there from the command */
8243 	if (needclr)
8244 	    msg_clr_eos();
8245 	if (eap->cmdidx == CMD_echo)
8246 	    msg_end();
8247     }
8248 }
8249 
8250 /*
8251  * ":echohl {name}".
8252  */
8253     void
8254 ex_echohl(exarg_T *eap)
8255 {
8256     int		id;
8257 
8258     id = syn_name2id(eap->arg);
8259     if (id == 0)
8260 	echo_attr = 0;
8261     else
8262 	echo_attr = syn_id2attr(id);
8263 }
8264 
8265 /*
8266  * ":execute expr1 ..."	execute the result of an expression.
8267  * ":echomsg expr1 ..."	Print a message
8268  * ":echoerr expr1 ..."	Print an error
8269  * Each gets spaces around each argument and a newline at the end for
8270  * echo commands
8271  */
8272     void
8273 ex_execute(exarg_T *eap)
8274 {
8275     char_u	*arg = eap->arg;
8276     typval_T	rettv;
8277     int		ret = OK;
8278     char_u	*p;
8279     garray_T	ga;
8280     int		len;
8281     int		save_did_emsg;
8282 
8283     ga_init2(&ga, 1, 80);
8284 
8285     if (eap->skip)
8286 	++emsg_skip;
8287     while (*arg != NUL && *arg != '|' && *arg != '\n')
8288     {
8289 	p = arg;
8290 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8291 	{
8292 	    /*
8293 	     * Report the invalid expression unless the expression evaluation
8294 	     * has been cancelled due to an aborting error, an interrupt, or an
8295 	     * exception.
8296 	     */
8297 	    if (!aborting())
8298 		EMSG2(_(e_invexpr2), p);
8299 	    ret = FAIL;
8300 	    break;
8301 	}
8302 
8303 	if (!eap->skip)
8304 	{
8305 	    p = get_tv_string(&rettv);
8306 	    len = (int)STRLEN(p);
8307 	    if (ga_grow(&ga, len + 2) == FAIL)
8308 	    {
8309 		clear_tv(&rettv);
8310 		ret = FAIL;
8311 		break;
8312 	    }
8313 	    if (ga.ga_len)
8314 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
8315 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
8316 	    ga.ga_len += len;
8317 	}
8318 
8319 	clear_tv(&rettv);
8320 	arg = skipwhite(arg);
8321     }
8322 
8323     if (ret != FAIL && ga.ga_data != NULL)
8324     {
8325 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
8326 	{
8327 	    /* Mark the already saved text as finishing the line, so that what
8328 	     * follows is displayed on a new line when scrolling back at the
8329 	     * more prompt. */
8330 	    msg_sb_eol();
8331 	}
8332 
8333 	if (eap->cmdidx == CMD_echomsg)
8334 	{
8335 	    MSG_ATTR(ga.ga_data, echo_attr);
8336 	    out_flush();
8337 	}
8338 	else if (eap->cmdidx == CMD_echoerr)
8339 	{
8340 	    /* We don't want to abort following commands, restore did_emsg. */
8341 	    save_did_emsg = did_emsg;
8342 	    EMSG((char_u *)ga.ga_data);
8343 	    if (!force_abort)
8344 		did_emsg = save_did_emsg;
8345 	}
8346 	else if (eap->cmdidx == CMD_execute)
8347 	    do_cmdline((char_u *)ga.ga_data,
8348 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
8349     }
8350 
8351     ga_clear(&ga);
8352 
8353     if (eap->skip)
8354 	--emsg_skip;
8355 
8356     eap->nextcmd = check_nextcmd(arg);
8357 }
8358 
8359 /*
8360  * Find window specified by "vp" in tabpage "tp".
8361  */
8362     win_T *
8363 find_win_by_nr(
8364     typval_T	*vp,
8365     tabpage_T	*tp UNUSED)	/* NULL for current tab page */
8366 {
8367 #ifdef FEAT_WINDOWS
8368     win_T	*wp;
8369 #endif
8370     int		nr;
8371 
8372     nr = (int)get_tv_number_chk(vp, NULL);
8373 
8374 #ifdef FEAT_WINDOWS
8375     if (nr < 0)
8376 	return NULL;
8377     if (nr == 0)
8378 	return curwin;
8379 
8380     FOR_ALL_WINDOWS_IN_TAB(tp, wp)
8381     {
8382 	if (nr >= LOWEST_WIN_ID)
8383 	{
8384 	    if (wp->w_id == nr)
8385 		return wp;
8386 	}
8387 	else if (--nr <= 0)
8388 	    break;
8389     }
8390     if (nr >= LOWEST_WIN_ID)
8391 	return NULL;
8392     return wp;
8393 #else
8394     if (nr == 0 || nr == 1 || nr == curwin->w_id)
8395 	return curwin;
8396     return NULL;
8397 #endif
8398 }
8399 
8400 /*
8401  * Find window specified by "wvp" in tabpage "tvp".
8402  */
8403     win_T *
8404 find_tabwin(
8405     typval_T	*wvp,	/* VAR_UNKNOWN for current window */
8406     typval_T	*tvp)	/* VAR_UNKNOWN for current tab page */
8407 {
8408     win_T	*wp = NULL;
8409     tabpage_T	*tp = NULL;
8410     long	n;
8411 
8412     if (wvp->v_type != VAR_UNKNOWN)
8413     {
8414 	if (tvp->v_type != VAR_UNKNOWN)
8415 	{
8416 	    n = (long)get_tv_number(tvp);
8417 	    if (n >= 0)
8418 		tp = find_tabpage(n);
8419 	}
8420 	else
8421 	    tp = curtab;
8422 
8423 	if (tp != NULL)
8424 	    wp = find_win_by_nr(wvp, tp);
8425     }
8426     else
8427 	wp = curwin;
8428 
8429     return wp;
8430 }
8431 
8432 /*
8433  * getwinvar() and gettabwinvar()
8434  */
8435     void
8436 getwinvar(
8437     typval_T	*argvars,
8438     typval_T	*rettv,
8439     int		off)	    /* 1 for gettabwinvar() */
8440 {
8441     win_T	*win;
8442     char_u	*varname;
8443     dictitem_T	*v;
8444     tabpage_T	*tp = NULL;
8445     int		done = FALSE;
8446 #ifdef FEAT_WINDOWS
8447     win_T	*oldcurwin;
8448     tabpage_T	*oldtabpage;
8449     int		need_switch_win;
8450 #endif
8451 
8452 #ifdef FEAT_WINDOWS
8453     if (off == 1)
8454 	tp = find_tabpage((int)get_tv_number_chk(&argvars[0], NULL));
8455     else
8456 	tp = curtab;
8457 #endif
8458     win = find_win_by_nr(&argvars[off], tp);
8459     varname = get_tv_string_chk(&argvars[off + 1]);
8460     ++emsg_off;
8461 
8462     rettv->v_type = VAR_STRING;
8463     rettv->vval.v_string = NULL;
8464 
8465     if (win != NULL && varname != NULL)
8466     {
8467 #ifdef FEAT_WINDOWS
8468 	/* Set curwin to be our win, temporarily.  Also set the tabpage,
8469 	 * otherwise the window is not valid. Only do this when needed,
8470 	 * autocommands get blocked. */
8471 	need_switch_win = !(tp == curtab && win == curwin);
8472 	if (!need_switch_win
8473 		  || switch_win(&oldcurwin, &oldtabpage, win, tp, TRUE) == OK)
8474 #endif
8475 	{
8476 	    if (*varname == '&')
8477 	    {
8478 		if (varname[1] == NUL)
8479 		{
8480 		    /* get all window-local options in a dict */
8481 		    dict_T	*opts = get_winbuf_options(FALSE);
8482 
8483 		    if (opts != NULL)
8484 		    {
8485 			rettv->v_type = VAR_DICT;
8486 			rettv->vval.v_dict = opts;
8487 			++opts->dv_refcount;
8488 			done = TRUE;
8489 		    }
8490 		}
8491 		else if (get_option_tv(&varname, rettv, 1) == OK)
8492 		    /* window-local-option */
8493 		    done = TRUE;
8494 	    }
8495 	    else
8496 	    {
8497 		/* Look up the variable. */
8498 		/* Let getwinvar({nr}, "") return the "w:" dictionary. */
8499 		v = find_var_in_ht(&win->w_vars->dv_hashtab, 'w',
8500 							      varname, FALSE);
8501 		if (v != NULL)
8502 		{
8503 		    copy_tv(&v->di_tv, rettv);
8504 		    done = TRUE;
8505 		}
8506 	    }
8507 	}
8508 
8509 #ifdef FEAT_WINDOWS
8510 	if (need_switch_win)
8511 	    /* restore previous notion of curwin */
8512 	    restore_win(oldcurwin, oldtabpage, TRUE);
8513 #endif
8514     }
8515 
8516     if (!done && argvars[off + 2].v_type != VAR_UNKNOWN)
8517 	/* use the default return value */
8518 	copy_tv(&argvars[off + 2], rettv);
8519 
8520     --emsg_off;
8521 }
8522 
8523 /*
8524  * "setwinvar()" and "settabwinvar()" functions
8525  */
8526     void
8527 setwinvar(typval_T *argvars, typval_T *rettv UNUSED, int off)
8528 {
8529     win_T	*win;
8530 #ifdef FEAT_WINDOWS
8531     win_T	*save_curwin;
8532     tabpage_T	*save_curtab;
8533     int		need_switch_win;
8534 #endif
8535     char_u	*varname, *winvarname;
8536     typval_T	*varp;
8537     char_u	nbuf[NUMBUFLEN];
8538     tabpage_T	*tp = NULL;
8539 
8540     if (check_restricted() || check_secure())
8541 	return;
8542 
8543 #ifdef FEAT_WINDOWS
8544     if (off == 1)
8545 	tp = find_tabpage((int)get_tv_number_chk(&argvars[0], NULL));
8546     else
8547 	tp = curtab;
8548 #endif
8549     win = find_win_by_nr(&argvars[off], tp);
8550     varname = get_tv_string_chk(&argvars[off + 1]);
8551     varp = &argvars[off + 2];
8552 
8553     if (win != NULL && varname != NULL && varp != NULL)
8554     {
8555 #ifdef FEAT_WINDOWS
8556 	need_switch_win = !(tp == curtab && win == curwin);
8557 	if (!need_switch_win
8558 	       || switch_win(&save_curwin, &save_curtab, win, tp, TRUE) == OK)
8559 #endif
8560 	{
8561 	    if (*varname == '&')
8562 	    {
8563 		long	numval;
8564 		char_u	*strval;
8565 		int		error = FALSE;
8566 
8567 		++varname;
8568 		numval = (long)get_tv_number_chk(varp, &error);
8569 		strval = get_tv_string_buf_chk(varp, nbuf);
8570 		if (!error && strval != NULL)
8571 		    set_option_value(varname, numval, strval, OPT_LOCAL);
8572 	    }
8573 	    else
8574 	    {
8575 		winvarname = alloc((unsigned)STRLEN(varname) + 3);
8576 		if (winvarname != NULL)
8577 		{
8578 		    STRCPY(winvarname, "w:");
8579 		    STRCPY(winvarname + 2, varname);
8580 		    set_var(winvarname, varp, TRUE);
8581 		    vim_free(winvarname);
8582 		}
8583 	    }
8584 	}
8585 #ifdef FEAT_WINDOWS
8586 	if (need_switch_win)
8587 	    restore_win(save_curwin, save_curtab, TRUE);
8588 #endif
8589     }
8590 }
8591 
8592 /*
8593  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
8594  * "arg" points to the "&" or '+' when called, to "option" when returning.
8595  * Returns NULL when no option name found.  Otherwise pointer to the char
8596  * after the option name.
8597  */
8598     static char_u *
8599 find_option_end(char_u **arg, int *opt_flags)
8600 {
8601     char_u	*p = *arg;
8602 
8603     ++p;
8604     if (*p == 'g' && p[1] == ':')
8605     {
8606 	*opt_flags = OPT_GLOBAL;
8607 	p += 2;
8608     }
8609     else if (*p == 'l' && p[1] == ':')
8610     {
8611 	*opt_flags = OPT_LOCAL;
8612 	p += 2;
8613     }
8614     else
8615 	*opt_flags = 0;
8616 
8617     if (!ASCII_ISALPHA(*p))
8618 	return NULL;
8619     *arg = p;
8620 
8621     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
8622 	p += 4;	    /* termcap option */
8623     else
8624 	while (ASCII_ISALPHA(*p))
8625 	    ++p;
8626     return p;
8627 }
8628 
8629 /*
8630  * Return the autoload script name for a function or variable name.
8631  * Returns NULL when out of memory.
8632  */
8633     char_u *
8634 autoload_name(char_u *name)
8635 {
8636     char_u	*p;
8637     char_u	*scriptname;
8638 
8639     /* Get the script file name: replace '#' with '/', append ".vim". */
8640     scriptname = alloc((unsigned)(STRLEN(name) + 14));
8641     if (scriptname == NULL)
8642 	return FALSE;
8643     STRCPY(scriptname, "autoload/");
8644     STRCAT(scriptname, name);
8645     *vim_strrchr(scriptname, AUTOLOAD_CHAR) = NUL;
8646     STRCAT(scriptname, ".vim");
8647     while ((p = vim_strchr(scriptname, AUTOLOAD_CHAR)) != NULL)
8648 	*p = '/';
8649     return scriptname;
8650 }
8651 
8652 /*
8653  * If "name" has a package name try autoloading the script for it.
8654  * Return TRUE if a package was loaded.
8655  */
8656     int
8657 script_autoload(
8658     char_u	*name,
8659     int		reload)	    /* load script again when already loaded */
8660 {
8661     char_u	*p;
8662     char_u	*scriptname, *tofree;
8663     int		ret = FALSE;
8664     int		i;
8665 
8666     /* If there is no '#' after name[0] there is no package name. */
8667     p = vim_strchr(name, AUTOLOAD_CHAR);
8668     if (p == NULL || p == name)
8669 	return FALSE;
8670 
8671     tofree = scriptname = autoload_name(name);
8672 
8673     /* Find the name in the list of previously loaded package names.  Skip
8674      * "autoload/", it's always the same. */
8675     for (i = 0; i < ga_loaded.ga_len; ++i)
8676 	if (STRCMP(((char_u **)ga_loaded.ga_data)[i] + 9, scriptname + 9) == 0)
8677 	    break;
8678     if (!reload && i < ga_loaded.ga_len)
8679 	ret = FALSE;	    /* was loaded already */
8680     else
8681     {
8682 	/* Remember the name if it wasn't loaded already. */
8683 	if (i == ga_loaded.ga_len && ga_grow(&ga_loaded, 1) == OK)
8684 	{
8685 	    ((char_u **)ga_loaded.ga_data)[ga_loaded.ga_len++] = scriptname;
8686 	    tofree = NULL;
8687 	}
8688 
8689 	/* Try loading the package from $VIMRUNTIME/autoload/<name>.vim */
8690 	if (source_runtime(scriptname, 0) == OK)
8691 	    ret = TRUE;
8692     }
8693 
8694     vim_free(tofree);
8695     return ret;
8696 }
8697 
8698 #if defined(FEAT_VIMINFO) || defined(FEAT_SESSION)
8699 typedef enum
8700 {
8701     VAR_FLAVOUR_DEFAULT,	/* doesn't start with uppercase */
8702     VAR_FLAVOUR_SESSION,	/* starts with uppercase, some lower */
8703     VAR_FLAVOUR_VIMINFO		/* all uppercase */
8704 } var_flavour_T;
8705 
8706 static var_flavour_T var_flavour(char_u *varname);
8707 
8708     static var_flavour_T
8709 var_flavour(char_u *varname)
8710 {
8711     char_u *p = varname;
8712 
8713     if (ASCII_ISUPPER(*p))
8714     {
8715 	while (*(++p))
8716 	    if (ASCII_ISLOWER(*p))
8717 		return VAR_FLAVOUR_SESSION;
8718 	return VAR_FLAVOUR_VIMINFO;
8719     }
8720     else
8721 	return VAR_FLAVOUR_DEFAULT;
8722 }
8723 #endif
8724 
8725 #if defined(FEAT_VIMINFO) || defined(PROTO)
8726 /*
8727  * Restore global vars that start with a capital from the viminfo file
8728  */
8729     int
8730 read_viminfo_varlist(vir_T *virp, int writing)
8731 {
8732     char_u	*tab;
8733     int		type = VAR_NUMBER;
8734     typval_T	tv;
8735     void	*save_funccal;
8736 
8737     if (!writing && (find_viminfo_parameter('!') != NULL))
8738     {
8739 	tab = vim_strchr(virp->vir_line + 1, '\t');
8740 	if (tab != NULL)
8741 	{
8742 	    *tab++ = '\0';	/* isolate the variable name */
8743 	    switch (*tab)
8744 	    {
8745 		case 'S': type = VAR_STRING; break;
8746 #ifdef FEAT_FLOAT
8747 		case 'F': type = VAR_FLOAT; break;
8748 #endif
8749 		case 'D': type = VAR_DICT; break;
8750 		case 'L': type = VAR_LIST; break;
8751 		case 'X': type = VAR_SPECIAL; break;
8752 	    }
8753 
8754 	    tab = vim_strchr(tab, '\t');
8755 	    if (tab != NULL)
8756 	    {
8757 		tv.v_type = type;
8758 		if (type == VAR_STRING || type == VAR_DICT || type == VAR_LIST)
8759 		    tv.vval.v_string = viminfo_readstring(virp,
8760 				       (int)(tab - virp->vir_line + 1), TRUE);
8761 #ifdef FEAT_FLOAT
8762 		else if (type == VAR_FLOAT)
8763 		    (void)string2float(tab + 1, &tv.vval.v_float);
8764 #endif
8765 		else
8766 		    tv.vval.v_number = atol((char *)tab + 1);
8767 		if (type == VAR_DICT || type == VAR_LIST)
8768 		{
8769 		    typval_T *etv = eval_expr(tv.vval.v_string, NULL);
8770 
8771 		    if (etv == NULL)
8772 			/* Failed to parse back the dict or list, use it as a
8773 			 * string. */
8774 			tv.v_type = VAR_STRING;
8775 		    else
8776 		    {
8777 			vim_free(tv.vval.v_string);
8778 			tv = *etv;
8779 			vim_free(etv);
8780 		    }
8781 		}
8782 
8783 		/* when in a function use global variables */
8784 		save_funccal = clear_current_funccal();
8785 		set_var(virp->vir_line + 1, &tv, FALSE);
8786 		restore_current_funccal(save_funccal);
8787 
8788 		if (tv.v_type == VAR_STRING)
8789 		    vim_free(tv.vval.v_string);
8790 		else if (tv.v_type == VAR_DICT || tv.v_type == VAR_LIST)
8791 		    clear_tv(&tv);
8792 	    }
8793 	}
8794     }
8795 
8796     return viminfo_readline(virp);
8797 }
8798 
8799 /*
8800  * Write global vars that start with a capital to the viminfo file
8801  */
8802     void
8803 write_viminfo_varlist(FILE *fp)
8804 {
8805     hashitem_T	*hi;
8806     dictitem_T	*this_var;
8807     int		todo;
8808     char	*s = "";
8809     char_u	*p;
8810     char_u	*tofree;
8811     char_u	numbuf[NUMBUFLEN];
8812 
8813     if (find_viminfo_parameter('!') == NULL)
8814 	return;
8815 
8816     fputs(_("\n# global variables:\n"), fp);
8817 
8818     todo = (int)globvarht.ht_used;
8819     for (hi = globvarht.ht_array; todo > 0; ++hi)
8820     {
8821 	if (!HASHITEM_EMPTY(hi))
8822 	{
8823 	    --todo;
8824 	    this_var = HI2DI(hi);
8825 	    if (var_flavour(this_var->di_key) == VAR_FLAVOUR_VIMINFO)
8826 	    {
8827 		switch (this_var->di_tv.v_type)
8828 		{
8829 		    case VAR_STRING: s = "STR"; break;
8830 		    case VAR_NUMBER: s = "NUM"; break;
8831 		    case VAR_FLOAT:  s = "FLO"; break;
8832 		    case VAR_DICT:   s = "DIC"; break;
8833 		    case VAR_LIST:   s = "LIS"; break;
8834 		    case VAR_SPECIAL: s = "XPL"; break;
8835 
8836 		    case VAR_UNKNOWN:
8837 		    case VAR_FUNC:
8838 		    case VAR_PARTIAL:
8839 		    case VAR_JOB:
8840 		    case VAR_CHANNEL:
8841 				     continue;
8842 		}
8843 		fprintf(fp, "!%s\t%s\t", this_var->di_key, s);
8844 		p = echo_string(&this_var->di_tv, &tofree, numbuf, 0);
8845 		if (p != NULL)
8846 		    viminfo_writestring(fp, p);
8847 		vim_free(tofree);
8848 	    }
8849 	}
8850     }
8851 }
8852 #endif
8853 
8854 #if defined(FEAT_SESSION) || defined(PROTO)
8855     int
8856 store_session_globals(FILE *fd)
8857 {
8858     hashitem_T	*hi;
8859     dictitem_T	*this_var;
8860     int		todo;
8861     char_u	*p, *t;
8862 
8863     todo = (int)globvarht.ht_used;
8864     for (hi = globvarht.ht_array; todo > 0; ++hi)
8865     {
8866 	if (!HASHITEM_EMPTY(hi))
8867 	{
8868 	    --todo;
8869 	    this_var = HI2DI(hi);
8870 	    if ((this_var->di_tv.v_type == VAR_NUMBER
8871 			|| this_var->di_tv.v_type == VAR_STRING)
8872 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
8873 	    {
8874 		/* Escape special characters with a backslash.  Turn a LF and
8875 		 * CR into \n and \r. */
8876 		p = vim_strsave_escaped(get_tv_string(&this_var->di_tv),
8877 							(char_u *)"\\\"\n\r");
8878 		if (p == NULL)	    /* out of memory */
8879 		    break;
8880 		for (t = p; *t != NUL; ++t)
8881 		    if (*t == '\n')
8882 			*t = 'n';
8883 		    else if (*t == '\r')
8884 			*t = 'r';
8885 		if ((fprintf(fd, "let %s = %c%s%c",
8886 				this_var->di_key,
8887 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
8888 									: ' ',
8889 				p,
8890 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
8891 								   : ' ') < 0)
8892 			|| put_eol(fd) == FAIL)
8893 		{
8894 		    vim_free(p);
8895 		    return FAIL;
8896 		}
8897 		vim_free(p);
8898 	    }
8899 #ifdef FEAT_FLOAT
8900 	    else if (this_var->di_tv.v_type == VAR_FLOAT
8901 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
8902 	    {
8903 		float_T f = this_var->di_tv.vval.v_float;
8904 		int sign = ' ';
8905 
8906 		if (f < 0)
8907 		{
8908 		    f = -f;
8909 		    sign = '-';
8910 		}
8911 		if ((fprintf(fd, "let %s = %c%f",
8912 					       this_var->di_key, sign, f) < 0)
8913 			|| put_eol(fd) == FAIL)
8914 		    return FAIL;
8915 	    }
8916 #endif
8917 	}
8918     }
8919     return OK;
8920 }
8921 #endif
8922 
8923 /*
8924  * Display script name where an item was last set.
8925  * Should only be invoked when 'verbose' is non-zero.
8926  */
8927     void
8928 last_set_msg(scid_T scriptID)
8929 {
8930     char_u *p;
8931 
8932     if (scriptID != 0)
8933     {
8934 	p = home_replace_save(NULL, get_scriptname(scriptID));
8935 	if (p != NULL)
8936 	{
8937 	    verbose_enter();
8938 	    MSG_PUTS(_("\n\tLast set from "));
8939 	    MSG_PUTS(p);
8940 	    vim_free(p);
8941 	    verbose_leave();
8942 	}
8943     }
8944 }
8945 
8946 /* reset v:option_new, v:option_old and v:option_type */
8947     void
8948 reset_v_option_vars(void)
8949 {
8950     set_vim_var_string(VV_OPTION_NEW,  NULL, -1);
8951     set_vim_var_string(VV_OPTION_OLD,  NULL, -1);
8952     set_vim_var_string(VV_OPTION_TYPE, NULL, -1);
8953 }
8954 
8955 /*
8956  * Prepare "gap" for an assert error and add the sourcing position.
8957  */
8958     void
8959 prepare_assert_error(garray_T *gap)
8960 {
8961     char buf[NUMBUFLEN];
8962 
8963     ga_init2(gap, 1, 100);
8964     if (sourcing_name != NULL)
8965     {
8966 	ga_concat(gap, sourcing_name);
8967 	if (sourcing_lnum > 0)
8968 	    ga_concat(gap, (char_u *)" ");
8969     }
8970     if (sourcing_lnum > 0)
8971     {
8972 	sprintf(buf, "line %ld", (long)sourcing_lnum);
8973 	ga_concat(gap, (char_u *)buf);
8974     }
8975     if (sourcing_name != NULL || sourcing_lnum > 0)
8976 	ga_concat(gap, (char_u *)": ");
8977 }
8978 
8979 /*
8980  * Add an assert error to v:errors.
8981  */
8982     void
8983 assert_error(garray_T *gap)
8984 {
8985     struct vimvar   *vp = &vimvars[VV_ERRORS];
8986 
8987     if (vp->vv_type != VAR_LIST || vimvars[VV_ERRORS].vv_list == NULL)
8988 	/* Make sure v:errors is a list. */
8989 	set_vim_var_list(VV_ERRORS, list_alloc());
8990     list_append_string(vimvars[VV_ERRORS].vv_list, gap->ga_data, gap->ga_len);
8991 }
8992 
8993     void
8994 assert_equal_common(typval_T *argvars, assert_type_T atype)
8995 {
8996     garray_T	ga;
8997 
8998     if (tv_equal(&argvars[0], &argvars[1], FALSE, FALSE)
8999 						   != (atype == ASSERT_EQUAL))
9000     {
9001 	prepare_assert_error(&ga);
9002 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
9003 								       atype);
9004 	assert_error(&ga);
9005 	ga_clear(&ga);
9006     }
9007 }
9008 
9009     void
9010 assert_match_common(typval_T *argvars, assert_type_T atype)
9011 {
9012     garray_T	ga;
9013     char_u	buf1[NUMBUFLEN];
9014     char_u	buf2[NUMBUFLEN];
9015     char_u	*pat = get_tv_string_buf_chk(&argvars[0], buf1);
9016     char_u	*text = get_tv_string_buf_chk(&argvars[1], buf2);
9017 
9018     if (pat == NULL || text == NULL)
9019 	EMSG(_(e_invarg));
9020     else if (pattern_match(pat, text, FALSE) != (atype == ASSERT_MATCH))
9021     {
9022 	prepare_assert_error(&ga);
9023 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
9024 									atype);
9025 	assert_error(&ga);
9026 	ga_clear(&ga);
9027     }
9028 }
9029 
9030     void
9031 assert_inrange(typval_T *argvars)
9032 {
9033     garray_T	ga;
9034     int		error = FALSE;
9035     varnumber_T	lower = get_tv_number_chk(&argvars[0], &error);
9036     varnumber_T	upper = get_tv_number_chk(&argvars[1], &error);
9037     varnumber_T	actual = get_tv_number_chk(&argvars[2], &error);
9038     char_u	*tofree;
9039     char	msg[200];
9040     char_u	numbuf[NUMBUFLEN];
9041 
9042     if (error)
9043 	return;
9044     if (actual < lower || actual > upper)
9045     {
9046 	prepare_assert_error(&ga);
9047 	if (argvars[3].v_type != VAR_UNKNOWN)
9048 	{
9049 	    ga_concat(&ga, tv2string(&argvars[3], &tofree, numbuf, 0));
9050 	    vim_free(tofree);
9051 	}
9052 	else
9053 	{
9054 	    vim_snprintf(msg, 200, "Expected range %ld - %ld, but got %ld",
9055 				       (long)lower, (long)upper, (long)actual);
9056 	    ga_concat(&ga, (char_u *)msg);
9057 	}
9058 	assert_error(&ga);
9059 	ga_clear(&ga);
9060     }
9061 }
9062 
9063 /*
9064  * Common for assert_true() and assert_false().
9065  */
9066     void
9067 assert_bool(typval_T *argvars, int isTrue)
9068 {
9069     int		error = FALSE;
9070     garray_T	ga;
9071 
9072     if (argvars[0].v_type == VAR_SPECIAL
9073 	    && argvars[0].vval.v_number == (isTrue ? VVAL_TRUE : VVAL_FALSE))
9074 	return;
9075     if (argvars[0].v_type != VAR_NUMBER
9076 	    || (get_tv_number_chk(&argvars[0], &error) == 0) == isTrue
9077 	    || error)
9078     {
9079 	prepare_assert_error(&ga);
9080 	fill_assert_error(&ga, &argvars[1],
9081 		(char_u *)(isTrue ? "True" : "False"),
9082 		NULL, &argvars[0], ASSERT_OTHER);
9083 	assert_error(&ga);
9084 	ga_clear(&ga);
9085     }
9086 }
9087 
9088     void
9089 assert_report(typval_T *argvars)
9090 {
9091     garray_T	ga;
9092 
9093     prepare_assert_error(&ga);
9094     ga_concat(&ga, get_tv_string(&argvars[0]));
9095     assert_error(&ga);
9096     ga_clear(&ga);
9097 }
9098 
9099     void
9100 assert_exception(typval_T *argvars)
9101 {
9102     garray_T	ga;
9103     char_u	*error = get_tv_string_chk(&argvars[0]);
9104 
9105     if (vimvars[VV_EXCEPTION].vv_str == NULL)
9106     {
9107 	prepare_assert_error(&ga);
9108 	ga_concat(&ga, (char_u *)"v:exception is not set");
9109 	assert_error(&ga);
9110 	ga_clear(&ga);
9111     }
9112     else if (error != NULL
9113 	&& strstr((char *)vimvars[VV_EXCEPTION].vv_str, (char *)error) == NULL)
9114     {
9115 	prepare_assert_error(&ga);
9116 	fill_assert_error(&ga, &argvars[1], NULL, &argvars[0],
9117 				  &vimvars[VV_EXCEPTION].vv_tv, ASSERT_OTHER);
9118 	assert_error(&ga);
9119 	ga_clear(&ga);
9120     }
9121 }
9122 
9123     void
9124 assert_fails(typval_T *argvars)
9125 {
9126     char_u	*cmd = get_tv_string_chk(&argvars[0]);
9127     garray_T	ga;
9128 
9129     called_emsg = FALSE;
9130     suppress_errthrow = TRUE;
9131     emsg_silent = TRUE;
9132     do_cmdline_cmd(cmd);
9133     if (!called_emsg)
9134     {
9135 	prepare_assert_error(&ga);
9136 	ga_concat(&ga, (char_u *)"command did not fail: ");
9137 	ga_concat(&ga, cmd);
9138 	assert_error(&ga);
9139 	ga_clear(&ga);
9140     }
9141     else if (argvars[1].v_type != VAR_UNKNOWN)
9142     {
9143 	char_u	buf[NUMBUFLEN];
9144 	char	*error = (char *)get_tv_string_buf_chk(&argvars[1], buf);
9145 
9146 	if (error == NULL
9147 		  || strstr((char *)vimvars[VV_ERRMSG].vv_str, error) == NULL)
9148 	{
9149 	    prepare_assert_error(&ga);
9150 	    fill_assert_error(&ga, &argvars[2], NULL, &argvars[1],
9151 				     &vimvars[VV_ERRMSG].vv_tv, ASSERT_OTHER);
9152 	    assert_error(&ga);
9153 	    ga_clear(&ga);
9154 	}
9155     }
9156 
9157     called_emsg = FALSE;
9158     suppress_errthrow = FALSE;
9159     emsg_silent = FALSE;
9160     emsg_on_display = FALSE;
9161     set_vim_var_string(VV_ERRMSG, NULL, 0);
9162 }
9163 
9164 /*
9165  * Append "str" to "gap", escaping unprintable characters.
9166  * Changes NL to \n, CR to \r, etc.
9167  */
9168     static void
9169 ga_concat_esc(garray_T *gap, char_u *str)
9170 {
9171     char_u  *p;
9172     char_u  buf[NUMBUFLEN];
9173 
9174     if (str == NULL)
9175     {
9176 	ga_concat(gap, (char_u *)"NULL");
9177 	return;
9178     }
9179 
9180     for (p = str; *p != NUL; ++p)
9181 	switch (*p)
9182 	{
9183 	    case BS: ga_concat(gap, (char_u *)"\\b"); break;
9184 	    case ESC: ga_concat(gap, (char_u *)"\\e"); break;
9185 	    case FF: ga_concat(gap, (char_u *)"\\f"); break;
9186 	    case NL: ga_concat(gap, (char_u *)"\\n"); break;
9187 	    case TAB: ga_concat(gap, (char_u *)"\\t"); break;
9188 	    case CAR: ga_concat(gap, (char_u *)"\\r"); break;
9189 	    case '\\': ga_concat(gap, (char_u *)"\\\\"); break;
9190 	    default:
9191 		if (*p < ' ')
9192 		{
9193 		    vim_snprintf((char *)buf, NUMBUFLEN, "\\x%02x", *p);
9194 		    ga_concat(gap, buf);
9195 		}
9196 		else
9197 		    ga_append(gap, *p);
9198 		break;
9199 	}
9200 }
9201 
9202 /*
9203  * Fill "gap" with information about an assert error.
9204  */
9205     void
9206 fill_assert_error(
9207     garray_T	*gap,
9208     typval_T	*opt_msg_tv,
9209     char_u      *exp_str,
9210     typval_T	*exp_tv,
9211     typval_T	*got_tv,
9212     assert_type_T atype)
9213 {
9214     char_u	numbuf[NUMBUFLEN];
9215     char_u	*tofree;
9216 
9217     if (opt_msg_tv->v_type != VAR_UNKNOWN)
9218     {
9219 	ga_concat(gap, echo_string(opt_msg_tv, &tofree, numbuf, 0));
9220 	vim_free(tofree);
9221 	ga_concat(gap, (char_u *)": ");
9222     }
9223 
9224     if (atype == ASSERT_MATCH || atype == ASSERT_NOTMATCH)
9225 	ga_concat(gap, (char_u *)"Pattern ");
9226     else if (atype == ASSERT_NOTEQUAL)
9227 	ga_concat(gap, (char_u *)"Expected not equal to ");
9228     else
9229 	ga_concat(gap, (char_u *)"Expected ");
9230     if (exp_str == NULL)
9231     {
9232 	ga_concat_esc(gap, tv2string(exp_tv, &tofree, numbuf, 0));
9233 	vim_free(tofree);
9234     }
9235     else
9236 	ga_concat_esc(gap, exp_str);
9237     if (atype != ASSERT_NOTEQUAL)
9238     {
9239 	if (atype == ASSERT_MATCH)
9240 	    ga_concat(gap, (char_u *)" does not match ");
9241 	else if (atype == ASSERT_NOTMATCH)
9242 	    ga_concat(gap, (char_u *)" does match ");
9243 	else
9244 	    ga_concat(gap, (char_u *)" but got ");
9245 	ga_concat_esc(gap, tv2string(got_tv, &tofree, numbuf, 0));
9246 	vim_free(tofree);
9247     }
9248 }
9249 
9250 
9251 #endif /* FEAT_EVAL */
9252 
9253 
9254 #if defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) || defined(PROTO)
9255 
9256 #ifdef WIN3264
9257 /*
9258  * Functions for ":8" filename modifier: get 8.3 version of a filename.
9259  */
9260 static int get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen);
9261 static int shortpath_for_invalid_fname(char_u **fname, char_u **bufp, int *fnamelen);
9262 static int shortpath_for_partial(char_u **fnamep, char_u **bufp, int *fnamelen);
9263 
9264 /*
9265  * Get the short path (8.3) for the filename in "fnamep".
9266  * Only works for a valid file name.
9267  * When the path gets longer "fnamep" is changed and the allocated buffer
9268  * is put in "bufp".
9269  * *fnamelen is the length of "fnamep" and set to 0 for a nonexistent path.
9270  * Returns OK on success, FAIL on failure.
9271  */
9272     static int
9273 get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen)
9274 {
9275     int		l, len;
9276     char_u	*newbuf;
9277 
9278     len = *fnamelen;
9279     l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, len);
9280     if (l > len - 1)
9281     {
9282 	/* If that doesn't work (not enough space), then save the string
9283 	 * and try again with a new buffer big enough. */
9284 	newbuf = vim_strnsave(*fnamep, l);
9285 	if (newbuf == NULL)
9286 	    return FAIL;
9287 
9288 	vim_free(*bufp);
9289 	*fnamep = *bufp = newbuf;
9290 
9291 	/* Really should always succeed, as the buffer is big enough. */
9292 	l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, l+1);
9293     }
9294 
9295     *fnamelen = l;
9296     return OK;
9297 }
9298 
9299 /*
9300  * Get the short path (8.3) for the filename in "fname". The converted
9301  * path is returned in "bufp".
9302  *
9303  * Some of the directories specified in "fname" may not exist. This function
9304  * will shorten the existing directories at the beginning of the path and then
9305  * append the remaining non-existing path.
9306  *
9307  * fname - Pointer to the filename to shorten.  On return, contains the
9308  *	   pointer to the shortened pathname
9309  * bufp -  Pointer to an allocated buffer for the filename.
9310  * fnamelen - Length of the filename pointed to by fname
9311  *
9312  * Returns OK on success (or nothing done) and FAIL on failure (out of memory).
9313  */
9314     static int
9315 shortpath_for_invalid_fname(
9316     char_u	**fname,
9317     char_u	**bufp,
9318     int		*fnamelen)
9319 {
9320     char_u	*short_fname, *save_fname, *pbuf_unused;
9321     char_u	*endp, *save_endp;
9322     char_u	ch;
9323     int		old_len, len;
9324     int		new_len, sfx_len;
9325     int		retval = OK;
9326 
9327     /* Make a copy */
9328     old_len = *fnamelen;
9329     save_fname = vim_strnsave(*fname, old_len);
9330     pbuf_unused = NULL;
9331     short_fname = NULL;
9332 
9333     endp = save_fname + old_len - 1; /* Find the end of the copy */
9334     save_endp = endp;
9335 
9336     /*
9337      * Try shortening the supplied path till it succeeds by removing one
9338      * directory at a time from the tail of the path.
9339      */
9340     len = 0;
9341     for (;;)
9342     {
9343 	/* go back one path-separator */
9344 	while (endp > save_fname && !after_pathsep(save_fname, endp + 1))
9345 	    --endp;
9346 	if (endp <= save_fname)
9347 	    break;		/* processed the complete path */
9348 
9349 	/*
9350 	 * Replace the path separator with a NUL and try to shorten the
9351 	 * resulting path.
9352 	 */
9353 	ch = *endp;
9354 	*endp = 0;
9355 	short_fname = save_fname;
9356 	len = (int)STRLEN(short_fname) + 1;
9357 	if (get_short_pathname(&short_fname, &pbuf_unused, &len) == FAIL)
9358 	{
9359 	    retval = FAIL;
9360 	    goto theend;
9361 	}
9362 	*endp = ch;	/* preserve the string */
9363 
9364 	if (len > 0)
9365 	    break;	/* successfully shortened the path */
9366 
9367 	/* failed to shorten the path. Skip the path separator */
9368 	--endp;
9369     }
9370 
9371     if (len > 0)
9372     {
9373 	/*
9374 	 * Succeeded in shortening the path. Now concatenate the shortened
9375 	 * path with the remaining path at the tail.
9376 	 */
9377 
9378 	/* Compute the length of the new path. */
9379 	sfx_len = (int)(save_endp - endp) + 1;
9380 	new_len = len + sfx_len;
9381 
9382 	*fnamelen = new_len;
9383 	vim_free(*bufp);
9384 	if (new_len > old_len)
9385 	{
9386 	    /* There is not enough space in the currently allocated string,
9387 	     * copy it to a buffer big enough. */
9388 	    *fname = *bufp = vim_strnsave(short_fname, new_len);
9389 	    if (*fname == NULL)
9390 	    {
9391 		retval = FAIL;
9392 		goto theend;
9393 	    }
9394 	}
9395 	else
9396 	{
9397 	    /* Transfer short_fname to the main buffer (it's big enough),
9398 	     * unless get_short_pathname() did its work in-place. */
9399 	    *fname = *bufp = save_fname;
9400 	    if (short_fname != save_fname)
9401 		vim_strncpy(save_fname, short_fname, len);
9402 	    save_fname = NULL;
9403 	}
9404 
9405 	/* concat the not-shortened part of the path */
9406 	vim_strncpy(*fname + len, endp, sfx_len);
9407 	(*fname)[new_len] = NUL;
9408     }
9409 
9410 theend:
9411     vim_free(pbuf_unused);
9412     vim_free(save_fname);
9413 
9414     return retval;
9415 }
9416 
9417 /*
9418  * Get a pathname for a partial path.
9419  * Returns OK for success, FAIL for failure.
9420  */
9421     static int
9422 shortpath_for_partial(
9423     char_u	**fnamep,
9424     char_u	**bufp,
9425     int		*fnamelen)
9426 {
9427     int		sepcount, len, tflen;
9428     char_u	*p;
9429     char_u	*pbuf, *tfname;
9430     int		hasTilde;
9431 
9432     /* Count up the path separators from the RHS.. so we know which part
9433      * of the path to return. */
9434     sepcount = 0;
9435     for (p = *fnamep; p < *fnamep + *fnamelen; MB_PTR_ADV(p))
9436 	if (vim_ispathsep(*p))
9437 	    ++sepcount;
9438 
9439     /* Need full path first (use expand_env() to remove a "~/") */
9440     hasTilde = (**fnamep == '~');
9441     if (hasTilde)
9442 	pbuf = tfname = expand_env_save(*fnamep);
9443     else
9444 	pbuf = tfname = FullName_save(*fnamep, FALSE);
9445 
9446     len = tflen = (int)STRLEN(tfname);
9447 
9448     if (get_short_pathname(&tfname, &pbuf, &len) == FAIL)
9449 	return FAIL;
9450 
9451     if (len == 0)
9452     {
9453 	/* Don't have a valid filename, so shorten the rest of the
9454 	 * path if we can. This CAN give us invalid 8.3 filenames, but
9455 	 * there's not a lot of point in guessing what it might be.
9456 	 */
9457 	len = tflen;
9458 	if (shortpath_for_invalid_fname(&tfname, &pbuf, &len) == FAIL)
9459 	    return FAIL;
9460     }
9461 
9462     /* Count the paths backward to find the beginning of the desired string. */
9463     for (p = tfname + len - 1; p >= tfname; --p)
9464     {
9465 #ifdef FEAT_MBYTE
9466 	if (has_mbyte)
9467 	    p -= mb_head_off(tfname, p);
9468 #endif
9469 	if (vim_ispathsep(*p))
9470 	{
9471 	    if (sepcount == 0 || (hasTilde && sepcount == 1))
9472 		break;
9473 	    else
9474 		sepcount --;
9475 	}
9476     }
9477     if (hasTilde)
9478     {
9479 	--p;
9480 	if (p >= tfname)
9481 	    *p = '~';
9482 	else
9483 	    return FAIL;
9484     }
9485     else
9486 	++p;
9487 
9488     /* Copy in the string - p indexes into tfname - allocated at pbuf */
9489     vim_free(*bufp);
9490     *fnamelen = (int)STRLEN(p);
9491     *bufp = pbuf;
9492     *fnamep = p;
9493 
9494     return OK;
9495 }
9496 #endif /* WIN3264 */
9497 
9498 /*
9499  * Adjust a filename, according to a string of modifiers.
9500  * *fnamep must be NUL terminated when called.  When returning, the length is
9501  * determined by *fnamelen.
9502  * Returns VALID_ flags or -1 for failure.
9503  * When there is an error, *fnamep is set to NULL.
9504  */
9505     int
9506 modify_fname(
9507     char_u	*src,		/* string with modifiers */
9508     int		*usedlen,	/* characters after src that are used */
9509     char_u	**fnamep,	/* file name so far */
9510     char_u	**bufp,		/* buffer for allocated file name or NULL */
9511     int		*fnamelen)	/* length of fnamep */
9512 {
9513     int		valid = 0;
9514     char_u	*tail;
9515     char_u	*s, *p, *pbuf;
9516     char_u	dirname[MAXPATHL];
9517     int		c;
9518     int		has_fullname = 0;
9519 #ifdef WIN3264
9520     char_u	*fname_start = *fnamep;
9521     int		has_shortname = 0;
9522 #endif
9523 
9524 repeat:
9525     /* ":p" - full path/file_name */
9526     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'p')
9527     {
9528 	has_fullname = 1;
9529 
9530 	valid |= VALID_PATH;
9531 	*usedlen += 2;
9532 
9533 	/* Expand "~/path" for all systems and "~user/path" for Unix and VMS */
9534 	if ((*fnamep)[0] == '~'
9535 #if !defined(UNIX) && !(defined(VMS) && defined(USER_HOME))
9536 		&& ((*fnamep)[1] == '/'
9537 # ifdef BACKSLASH_IN_FILENAME
9538 		    || (*fnamep)[1] == '\\'
9539 # endif
9540 		    || (*fnamep)[1] == NUL)
9541 
9542 #endif
9543 	   )
9544 	{
9545 	    *fnamep = expand_env_save(*fnamep);
9546 	    vim_free(*bufp);	/* free any allocated file name */
9547 	    *bufp = *fnamep;
9548 	    if (*fnamep == NULL)
9549 		return -1;
9550 	}
9551 
9552 	/* When "/." or "/.." is used: force expansion to get rid of it. */
9553 	for (p = *fnamep; *p != NUL; MB_PTR_ADV(p))
9554 	{
9555 	    if (vim_ispathsep(*p)
9556 		    && p[1] == '.'
9557 		    && (p[2] == NUL
9558 			|| vim_ispathsep(p[2])
9559 			|| (p[2] == '.'
9560 			    && (p[3] == NUL || vim_ispathsep(p[3])))))
9561 		break;
9562 	}
9563 
9564 	/* FullName_save() is slow, don't use it when not needed. */
9565 	if (*p != NUL || !vim_isAbsName(*fnamep))
9566 	{
9567 	    *fnamep = FullName_save(*fnamep, *p != NUL);
9568 	    vim_free(*bufp);	/* free any allocated file name */
9569 	    *bufp = *fnamep;
9570 	    if (*fnamep == NULL)
9571 		return -1;
9572 	}
9573 
9574 #ifdef WIN3264
9575 # if _WIN32_WINNT >= 0x0500
9576 	if (vim_strchr(*fnamep, '~') != NULL)
9577 	{
9578 	    /* Expand 8.3 filename to full path.  Needed to make sure the same
9579 	     * file does not have two different names.
9580 	     * Note: problem does not occur if _WIN32_WINNT < 0x0500. */
9581 	    p = alloc(_MAX_PATH + 1);
9582 	    if (p != NULL)
9583 	    {
9584 		if (GetLongPathName((LPSTR)*fnamep, (LPSTR)p, _MAX_PATH))
9585 		{
9586 		    vim_free(*bufp);
9587 		    *bufp = *fnamep = p;
9588 		}
9589 		else
9590 		    vim_free(p);
9591 	    }
9592 	}
9593 # endif
9594 #endif
9595 	/* Append a path separator to a directory. */
9596 	if (mch_isdir(*fnamep))
9597 	{
9598 	    /* Make room for one or two extra characters. */
9599 	    *fnamep = vim_strnsave(*fnamep, (int)STRLEN(*fnamep) + 2);
9600 	    vim_free(*bufp);	/* free any allocated file name */
9601 	    *bufp = *fnamep;
9602 	    if (*fnamep == NULL)
9603 		return -1;
9604 	    add_pathsep(*fnamep);
9605 	}
9606     }
9607 
9608     /* ":." - path relative to the current directory */
9609     /* ":~" - path relative to the home directory */
9610     /* ":8" - shortname path - postponed till after */
9611     while (src[*usedlen] == ':'
9612 		  && ((c = src[*usedlen + 1]) == '.' || c == '~' || c == '8'))
9613     {
9614 	*usedlen += 2;
9615 	if (c == '8')
9616 	{
9617 #ifdef WIN3264
9618 	    has_shortname = 1; /* Postpone this. */
9619 #endif
9620 	    continue;
9621 	}
9622 	pbuf = NULL;
9623 	/* Need full path first (use expand_env() to remove a "~/") */
9624 	if (!has_fullname)
9625 	{
9626 	    if (c == '.' && **fnamep == '~')
9627 		p = pbuf = expand_env_save(*fnamep);
9628 	    else
9629 		p = pbuf = FullName_save(*fnamep, FALSE);
9630 	}
9631 	else
9632 	    p = *fnamep;
9633 
9634 	has_fullname = 0;
9635 
9636 	if (p != NULL)
9637 	{
9638 	    if (c == '.')
9639 	    {
9640 		mch_dirname(dirname, MAXPATHL);
9641 		s = shorten_fname(p, dirname);
9642 		if (s != NULL)
9643 		{
9644 		    *fnamep = s;
9645 		    if (pbuf != NULL)
9646 		    {
9647 			vim_free(*bufp);   /* free any allocated file name */
9648 			*bufp = pbuf;
9649 			pbuf = NULL;
9650 		    }
9651 		}
9652 	    }
9653 	    else
9654 	    {
9655 		home_replace(NULL, p, dirname, MAXPATHL, TRUE);
9656 		/* Only replace it when it starts with '~' */
9657 		if (*dirname == '~')
9658 		{
9659 		    s = vim_strsave(dirname);
9660 		    if (s != NULL)
9661 		    {
9662 			*fnamep = s;
9663 			vim_free(*bufp);
9664 			*bufp = s;
9665 		    }
9666 		}
9667 	    }
9668 	    vim_free(pbuf);
9669 	}
9670     }
9671 
9672     tail = gettail(*fnamep);
9673     *fnamelen = (int)STRLEN(*fnamep);
9674 
9675     /* ":h" - head, remove "/file_name", can be repeated  */
9676     /* Don't remove the first "/" or "c:\" */
9677     while (src[*usedlen] == ':' && src[*usedlen + 1] == 'h')
9678     {
9679 	valid |= VALID_HEAD;
9680 	*usedlen += 2;
9681 	s = get_past_head(*fnamep);
9682 	while (tail > s && after_pathsep(s, tail))
9683 	    MB_PTR_BACK(*fnamep, tail);
9684 	*fnamelen = (int)(tail - *fnamep);
9685 #ifdef VMS
9686 	if (*fnamelen > 0)
9687 	    *fnamelen += 1; /* the path separator is part of the path */
9688 #endif
9689 	if (*fnamelen == 0)
9690 	{
9691 	    /* Result is empty.  Turn it into "." to make ":cd %:h" work. */
9692 	    p = vim_strsave((char_u *)".");
9693 	    if (p == NULL)
9694 		return -1;
9695 	    vim_free(*bufp);
9696 	    *bufp = *fnamep = tail = p;
9697 	    *fnamelen = 1;
9698 	}
9699 	else
9700 	{
9701 	    while (tail > s && !after_pathsep(s, tail))
9702 		MB_PTR_BACK(*fnamep, tail);
9703 	}
9704     }
9705 
9706     /* ":8" - shortname  */
9707     if (src[*usedlen] == ':' && src[*usedlen + 1] == '8')
9708     {
9709 	*usedlen += 2;
9710 #ifdef WIN3264
9711 	has_shortname = 1;
9712 #endif
9713     }
9714 
9715 #ifdef WIN3264
9716     /*
9717      * Handle ":8" after we have done 'heads' and before we do 'tails'.
9718      */
9719     if (has_shortname)
9720     {
9721 	/* Copy the string if it is shortened by :h and when it wasn't copied
9722 	 * yet, because we are going to change it in place.  Avoids changing
9723 	 * the buffer name for "%:8". */
9724 	if (*fnamelen < (int)STRLEN(*fnamep) || *fnamep == fname_start)
9725 	{
9726 	    p = vim_strnsave(*fnamep, *fnamelen);
9727 	    if (p == NULL)
9728 		return -1;
9729 	    vim_free(*bufp);
9730 	    *bufp = *fnamep = p;
9731 	}
9732 
9733 	/* Split into two implementations - makes it easier.  First is where
9734 	 * there isn't a full name already, second is where there is. */
9735 	if (!has_fullname && !vim_isAbsName(*fnamep))
9736 	{
9737 	    if (shortpath_for_partial(fnamep, bufp, fnamelen) == FAIL)
9738 		return -1;
9739 	}
9740 	else
9741 	{
9742 	    int		l = *fnamelen;
9743 
9744 	    /* Simple case, already have the full-name.
9745 	     * Nearly always shorter, so try first time. */
9746 	    if (get_short_pathname(fnamep, bufp, &l) == FAIL)
9747 		return -1;
9748 
9749 	    if (l == 0)
9750 	    {
9751 		/* Couldn't find the filename, search the paths. */
9752 		l = *fnamelen;
9753 		if (shortpath_for_invalid_fname(fnamep, bufp, &l) == FAIL)
9754 		    return -1;
9755 	    }
9756 	    *fnamelen = l;
9757 	}
9758     }
9759 #endif /* WIN3264 */
9760 
9761     /* ":t" - tail, just the basename */
9762     if (src[*usedlen] == ':' && src[*usedlen + 1] == 't')
9763     {
9764 	*usedlen += 2;
9765 	*fnamelen -= (int)(tail - *fnamep);
9766 	*fnamep = tail;
9767     }
9768 
9769     /* ":e" - extension, can be repeated */
9770     /* ":r" - root, without extension, can be repeated */
9771     while (src[*usedlen] == ':'
9772 	    && (src[*usedlen + 1] == 'e' || src[*usedlen + 1] == 'r'))
9773     {
9774 	/* find a '.' in the tail:
9775 	 * - for second :e: before the current fname
9776 	 * - otherwise: The last '.'
9777 	 */
9778 	if (src[*usedlen + 1] == 'e' && *fnamep > tail)
9779 	    s = *fnamep - 2;
9780 	else
9781 	    s = *fnamep + *fnamelen - 1;
9782 	for ( ; s > tail; --s)
9783 	    if (s[0] == '.')
9784 		break;
9785 	if (src[*usedlen + 1] == 'e')		/* :e */
9786 	{
9787 	    if (s > tail)
9788 	    {
9789 		*fnamelen += (int)(*fnamep - (s + 1));
9790 		*fnamep = s + 1;
9791 #ifdef VMS
9792 		/* cut version from the extension */
9793 		s = *fnamep + *fnamelen - 1;
9794 		for ( ; s > *fnamep; --s)
9795 		    if (s[0] == ';')
9796 			break;
9797 		if (s > *fnamep)
9798 		    *fnamelen = s - *fnamep;
9799 #endif
9800 	    }
9801 	    else if (*fnamep <= tail)
9802 		*fnamelen = 0;
9803 	}
9804 	else				/* :r */
9805 	{
9806 	    if (s > tail)	/* remove one extension */
9807 		*fnamelen = (int)(s - *fnamep);
9808 	}
9809 	*usedlen += 2;
9810     }
9811 
9812     /* ":s?pat?foo?" - substitute */
9813     /* ":gs?pat?foo?" - global substitute */
9814     if (src[*usedlen] == ':'
9815 	    && (src[*usedlen + 1] == 's'
9816 		|| (src[*usedlen + 1] == 'g' && src[*usedlen + 2] == 's')))
9817     {
9818 	char_u	    *str;
9819 	char_u	    *pat;
9820 	char_u	    *sub;
9821 	int	    sep;
9822 	char_u	    *flags;
9823 	int	    didit = FALSE;
9824 
9825 	flags = (char_u *)"";
9826 	s = src + *usedlen + 2;
9827 	if (src[*usedlen + 1] == 'g')
9828 	{
9829 	    flags = (char_u *)"g";
9830 	    ++s;
9831 	}
9832 
9833 	sep = *s++;
9834 	if (sep)
9835 	{
9836 	    /* find end of pattern */
9837 	    p = vim_strchr(s, sep);
9838 	    if (p != NULL)
9839 	    {
9840 		pat = vim_strnsave(s, (int)(p - s));
9841 		if (pat != NULL)
9842 		{
9843 		    s = p + 1;
9844 		    /* find end of substitution */
9845 		    p = vim_strchr(s, sep);
9846 		    if (p != NULL)
9847 		    {
9848 			sub = vim_strnsave(s, (int)(p - s));
9849 			str = vim_strnsave(*fnamep, *fnamelen);
9850 			if (sub != NULL && str != NULL)
9851 			{
9852 			    *usedlen = (int)(p + 1 - src);
9853 			    s = do_string_sub(str, pat, sub, NULL, flags);
9854 			    if (s != NULL)
9855 			    {
9856 				*fnamep = s;
9857 				*fnamelen = (int)STRLEN(s);
9858 				vim_free(*bufp);
9859 				*bufp = s;
9860 				didit = TRUE;
9861 			    }
9862 			}
9863 			vim_free(sub);
9864 			vim_free(str);
9865 		    }
9866 		    vim_free(pat);
9867 		}
9868 	    }
9869 	    /* after using ":s", repeat all the modifiers */
9870 	    if (didit)
9871 		goto repeat;
9872 	}
9873     }
9874 
9875     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'S')
9876     {
9877 	/* vim_strsave_shellescape() needs a NUL terminated string. */
9878 	c = (*fnamep)[*fnamelen];
9879 	if (c != NUL)
9880 	    (*fnamep)[*fnamelen] = NUL;
9881 	p = vim_strsave_shellescape(*fnamep, FALSE, FALSE);
9882 	if (c != NUL)
9883 	    (*fnamep)[*fnamelen] = c;
9884 	if (p == NULL)
9885 	    return -1;
9886 	vim_free(*bufp);
9887 	*bufp = *fnamep = p;
9888 	*fnamelen = (int)STRLEN(p);
9889 	*usedlen += 2;
9890     }
9891 
9892     return valid;
9893 }
9894 
9895 /*
9896  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
9897  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
9898  * "flags" can be "g" to do a global substitute.
9899  * Returns an allocated string, NULL for error.
9900  */
9901     char_u *
9902 do_string_sub(
9903     char_u	*str,
9904     char_u	*pat,
9905     char_u	*sub,
9906     typval_T	*expr,
9907     char_u	*flags)
9908 {
9909     int		sublen;
9910     regmatch_T	regmatch;
9911     int		i;
9912     int		do_all;
9913     char_u	*tail;
9914     char_u	*end;
9915     garray_T	ga;
9916     char_u	*ret;
9917     char_u	*save_cpo;
9918     char_u	*zero_width = NULL;
9919 
9920     /* Make 'cpoptions' empty, so that the 'l' flag doesn't work here */
9921     save_cpo = p_cpo;
9922     p_cpo = empty_option;
9923 
9924     ga_init2(&ga, 1, 200);
9925 
9926     do_all = (flags[0] == 'g');
9927 
9928     regmatch.rm_ic = p_ic;
9929     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
9930     if (regmatch.regprog != NULL)
9931     {
9932 	tail = str;
9933 	end = str + STRLEN(str);
9934 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
9935 	{
9936 	    /* Skip empty match except for first match. */
9937 	    if (regmatch.startp[0] == regmatch.endp[0])
9938 	    {
9939 		if (zero_width == regmatch.startp[0])
9940 		{
9941 		    /* avoid getting stuck on a match with an empty string */
9942 		    i = MB_PTR2LEN(tail);
9943 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
9944 								   (size_t)i);
9945 		    ga.ga_len += i;
9946 		    tail += i;
9947 		    continue;
9948 		}
9949 		zero_width = regmatch.startp[0];
9950 	    }
9951 
9952 	    /*
9953 	     * Get some space for a temporary buffer to do the substitution
9954 	     * into.  It will contain:
9955 	     * - The text up to where the match is.
9956 	     * - The substituted text.
9957 	     * - The text after the match.
9958 	     */
9959 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
9960 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
9961 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
9962 	    {
9963 		ga_clear(&ga);
9964 		break;
9965 	    }
9966 
9967 	    /* copy the text up to where the match is */
9968 	    i = (int)(regmatch.startp[0] - tail);
9969 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
9970 	    /* add the substituted text */
9971 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
9972 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
9973 	    ga.ga_len += i + sublen - 1;
9974 	    tail = regmatch.endp[0];
9975 	    if (*tail == NUL)
9976 		break;
9977 	    if (!do_all)
9978 		break;
9979 	}
9980 
9981 	if (ga.ga_data != NULL)
9982 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
9983 
9984 	vim_regfree(regmatch.regprog);
9985     }
9986 
9987     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
9988     ga_clear(&ga);
9989     if (p_cpo == empty_option)
9990 	p_cpo = save_cpo;
9991     else
9992 	/* Darn, evaluating {sub} expression or {expr} changed the value. */
9993 	free_string_option(save_cpo);
9994 
9995     return ret;
9996 }
9997 
9998     static int
9999 filter_map_one(typval_T *tv, typval_T *expr, int map, int *remp)
10000 {
10001     typval_T	rettv;
10002     typval_T	argv[3];
10003     char_u	buf[NUMBUFLEN];
10004     char_u	*s;
10005     int		retval = FAIL;
10006     int		dummy;
10007 
10008     copy_tv(tv, &vimvars[VV_VAL].vv_tv);
10009     argv[0] = vimvars[VV_KEY].vv_tv;
10010     argv[1] = vimvars[VV_VAL].vv_tv;
10011     if (expr->v_type == VAR_FUNC)
10012     {
10013 	s = expr->vval.v_string;
10014 	if (call_func(s, (int)STRLEN(s), &rettv, 2, argv, NULL,
10015 				     0L, 0L, &dummy, TRUE, NULL, NULL) == FAIL)
10016 	    goto theend;
10017     }
10018     else if (expr->v_type == VAR_PARTIAL)
10019     {
10020 	partial_T   *partial = expr->vval.v_partial;
10021 
10022 	s = partial_name(partial);
10023 	if (call_func(s, (int)STRLEN(s), &rettv, 2, argv, NULL,
10024 				  0L, 0L, &dummy, TRUE, partial, NULL) == FAIL)
10025 	    goto theend;
10026     }
10027     else
10028     {
10029 	s = get_tv_string_buf_chk(expr, buf);
10030 	if (s == NULL)
10031 	    goto theend;
10032 	s = skipwhite(s);
10033 	if (eval1(&s, &rettv, TRUE) == FAIL)
10034 	    goto theend;
10035 	if (*s != NUL)  /* check for trailing chars after expr */
10036 	{
10037 	    EMSG2(_(e_invexpr2), s);
10038 	    goto theend;
10039 	}
10040     }
10041     if (map)
10042     {
10043 	/* map(): replace the list item value */
10044 	clear_tv(tv);
10045 	rettv.v_lock = 0;
10046 	*tv = rettv;
10047     }
10048     else
10049     {
10050 	int	    error = FALSE;
10051 
10052 	/* filter(): when expr is zero remove the item */
10053 	*remp = (get_tv_number_chk(&rettv, &error) == 0);
10054 	clear_tv(&rettv);
10055 	/* On type error, nothing has been removed; return FAIL to stop the
10056 	 * loop.  The error message was given by get_tv_number_chk(). */
10057 	if (error)
10058 	    goto theend;
10059     }
10060     retval = OK;
10061 theend:
10062     clear_tv(&vimvars[VV_VAL].vv_tv);
10063     return retval;
10064 }
10065 
10066 
10067 /*
10068  * Implementation of map() and filter().
10069  */
10070     void
10071 filter_map(typval_T *argvars, typval_T *rettv, int map)
10072 {
10073     typval_T	*expr;
10074     listitem_T	*li, *nli;
10075     list_T	*l = NULL;
10076     dictitem_T	*di;
10077     hashtab_T	*ht;
10078     hashitem_T	*hi;
10079     dict_T	*d = NULL;
10080     typval_T	save_val;
10081     typval_T	save_key;
10082     int		rem;
10083     int		todo;
10084     char_u	*ermsg = (char_u *)(map ? "map()" : "filter()");
10085     char_u	*arg_errmsg = (char_u *)(map ? N_("map() argument")
10086 				   : N_("filter() argument"));
10087     int		save_did_emsg;
10088     int		idx = 0;
10089 
10090     if (argvars[0].v_type == VAR_LIST)
10091     {
10092 	if ((l = argvars[0].vval.v_list) == NULL
10093 	      || (!map && tv_check_lock(l->lv_lock, arg_errmsg, TRUE)))
10094 	    return;
10095     }
10096     else if (argvars[0].v_type == VAR_DICT)
10097     {
10098 	if ((d = argvars[0].vval.v_dict) == NULL
10099 	      || (!map && tv_check_lock(d->dv_lock, arg_errmsg, TRUE)))
10100 	    return;
10101     }
10102     else
10103     {
10104 	EMSG2(_(e_listdictarg), ermsg);
10105 	return;
10106     }
10107 
10108     expr = &argvars[1];
10109     /* On type errors, the preceding call has already displayed an error
10110      * message.  Avoid a misleading error message for an empty string that
10111      * was not passed as argument. */
10112     if (expr->v_type != VAR_UNKNOWN)
10113     {
10114 	prepare_vimvar(VV_VAL, &save_val);
10115 
10116 	/* We reset "did_emsg" to be able to detect whether an error
10117 	 * occurred during evaluation of the expression. */
10118 	save_did_emsg = did_emsg;
10119 	did_emsg = FALSE;
10120 
10121 	prepare_vimvar(VV_KEY, &save_key);
10122 	if (argvars[0].v_type == VAR_DICT)
10123 	{
10124 	    vimvars[VV_KEY].vv_type = VAR_STRING;
10125 
10126 	    ht = &d->dv_hashtab;
10127 	    hash_lock(ht);
10128 	    todo = (int)ht->ht_used;
10129 	    for (hi = ht->ht_array; todo > 0; ++hi)
10130 	    {
10131 		if (!HASHITEM_EMPTY(hi))
10132 		{
10133 		    int r;
10134 
10135 		    --todo;
10136 		    di = HI2DI(hi);
10137 		    if (map &&
10138 			    (tv_check_lock(di->di_tv.v_lock, arg_errmsg, TRUE)
10139 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE)))
10140 			break;
10141 		    vimvars[VV_KEY].vv_str = vim_strsave(di->di_key);
10142 		    r = filter_map_one(&di->di_tv, expr, map, &rem);
10143 		    clear_tv(&vimvars[VV_KEY].vv_tv);
10144 		    if (r == FAIL || did_emsg)
10145 			break;
10146 		    if (!map && rem)
10147 		    {
10148 			if (var_check_fixed(di->di_flags, arg_errmsg, TRUE)
10149 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE))
10150 			    break;
10151 			dictitem_remove(d, di);
10152 		    }
10153 		}
10154 	    }
10155 	    hash_unlock(ht);
10156 	}
10157 	else
10158 	{
10159 	    vimvars[VV_KEY].vv_type = VAR_NUMBER;
10160 
10161 	    for (li = l->lv_first; li != NULL; li = nli)
10162 	    {
10163 		if (map && tv_check_lock(li->li_tv.v_lock, arg_errmsg, TRUE))
10164 		    break;
10165 		nli = li->li_next;
10166 		vimvars[VV_KEY].vv_nr = idx;
10167 		if (filter_map_one(&li->li_tv, expr, map, &rem) == FAIL
10168 								  || did_emsg)
10169 		    break;
10170 		if (!map && rem)
10171 		    listitem_remove(l, li);
10172 		++idx;
10173 	    }
10174 	}
10175 
10176 	restore_vimvar(VV_KEY, &save_key);
10177 	restore_vimvar(VV_VAL, &save_val);
10178 
10179 	did_emsg |= save_did_emsg;
10180     }
10181 
10182     copy_tv(&argvars[0], rettv);
10183 }
10184 
10185 #endif /* defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) */
10186