xref: /vim-8.2.3635/src/eval.c (revision e16b00a1)
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_list_set(rettv, l);
4669 		}
4670 		else
4671 		{
4672 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
4673 		    clear_tv(rettv);
4674 		    *rettv = var1;
4675 		}
4676 		break;
4677 
4678 	    case VAR_DICT:
4679 		if (range)
4680 		{
4681 		    if (verbose)
4682 			EMSG(_(e_dictrange));
4683 		    if (len == -1)
4684 			clear_tv(&var1);
4685 		    return FAIL;
4686 		}
4687 		{
4688 		    dictitem_T	*item;
4689 
4690 		    if (len == -1)
4691 		    {
4692 			key = get_tv_string_chk(&var1);
4693 			if (key == NULL)
4694 			{
4695 			    clear_tv(&var1);
4696 			    return FAIL;
4697 			}
4698 		    }
4699 
4700 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
4701 
4702 		    if (item == NULL && verbose)
4703 			EMSG2(_(e_dictkey), key);
4704 		    if (len == -1)
4705 			clear_tv(&var1);
4706 		    if (item == NULL)
4707 			return FAIL;
4708 
4709 		    copy_tv(&item->di_tv, &var1);
4710 		    clear_tv(rettv);
4711 		    *rettv = var1;
4712 		}
4713 		break;
4714 	}
4715     }
4716 
4717     return OK;
4718 }
4719 
4720 /*
4721  * Get an option value.
4722  * "arg" points to the '&' or '+' before the option name.
4723  * "arg" is advanced to character after the option name.
4724  * Return OK or FAIL.
4725  */
4726     int
4727 get_option_tv(
4728     char_u	**arg,
4729     typval_T	*rettv,	/* when NULL, only check if option exists */
4730     int		evaluate)
4731 {
4732     char_u	*option_end;
4733     long	numval;
4734     char_u	*stringval;
4735     int		opt_type;
4736     int		c;
4737     int		working = (**arg == '+');    /* has("+option") */
4738     int		ret = OK;
4739     int		opt_flags;
4740 
4741     /*
4742      * Isolate the option name and find its value.
4743      */
4744     option_end = find_option_end(arg, &opt_flags);
4745     if (option_end == NULL)
4746     {
4747 	if (rettv != NULL)
4748 	    EMSG2(_("E112: Option name missing: %s"), *arg);
4749 	return FAIL;
4750     }
4751 
4752     if (!evaluate)
4753     {
4754 	*arg = option_end;
4755 	return OK;
4756     }
4757 
4758     c = *option_end;
4759     *option_end = NUL;
4760     opt_type = get_option_value(*arg, &numval,
4761 			       rettv == NULL ? NULL : &stringval, opt_flags);
4762 
4763     if (opt_type == -3)			/* invalid name */
4764     {
4765 	if (rettv != NULL)
4766 	    EMSG2(_("E113: Unknown option: %s"), *arg);
4767 	ret = FAIL;
4768     }
4769     else if (rettv != NULL)
4770     {
4771 	if (opt_type == -2)		/* hidden string option */
4772 	{
4773 	    rettv->v_type = VAR_STRING;
4774 	    rettv->vval.v_string = NULL;
4775 	}
4776 	else if (opt_type == -1)	/* hidden number option */
4777 	{
4778 	    rettv->v_type = VAR_NUMBER;
4779 	    rettv->vval.v_number = 0;
4780 	}
4781 	else if (opt_type == 1)		/* number option */
4782 	{
4783 	    rettv->v_type = VAR_NUMBER;
4784 	    rettv->vval.v_number = numval;
4785 	}
4786 	else				/* string option */
4787 	{
4788 	    rettv->v_type = VAR_STRING;
4789 	    rettv->vval.v_string = stringval;
4790 	}
4791     }
4792     else if (working && (opt_type == -2 || opt_type == -1))
4793 	ret = FAIL;
4794 
4795     *option_end = c;		    /* put back for error messages */
4796     *arg = option_end;
4797 
4798     return ret;
4799 }
4800 
4801 /*
4802  * Allocate a variable for a string constant.
4803  * Return OK or FAIL.
4804  */
4805     static int
4806 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
4807 {
4808     char_u	*p;
4809     char_u	*name;
4810     int		extra = 0;
4811 
4812     /*
4813      * Find the end of the string, skipping backslashed characters.
4814      */
4815     for (p = *arg + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
4816     {
4817 	if (*p == '\\' && p[1] != NUL)
4818 	{
4819 	    ++p;
4820 	    /* A "\<x>" form occupies at least 4 characters, and produces up
4821 	     * to 6 characters: reserve space for 2 extra */
4822 	    if (*p == '<')
4823 		extra += 2;
4824 	}
4825     }
4826 
4827     if (*p != '"')
4828     {
4829 	EMSG2(_("E114: Missing quote: %s"), *arg);
4830 	return FAIL;
4831     }
4832 
4833     /* If only parsing, set *arg and return here */
4834     if (!evaluate)
4835     {
4836 	*arg = p + 1;
4837 	return OK;
4838     }
4839 
4840     /*
4841      * Copy the string into allocated memory, handling backslashed
4842      * characters.
4843      */
4844     name = alloc((unsigned)(p - *arg + extra));
4845     if (name == NULL)
4846 	return FAIL;
4847     rettv->v_type = VAR_STRING;
4848     rettv->vval.v_string = name;
4849 
4850     for (p = *arg + 1; *p != NUL && *p != '"'; )
4851     {
4852 	if (*p == '\\')
4853 	{
4854 	    switch (*++p)
4855 	    {
4856 		case 'b': *name++ = BS; ++p; break;
4857 		case 'e': *name++ = ESC; ++p; break;
4858 		case 'f': *name++ = FF; ++p; break;
4859 		case 'n': *name++ = NL; ++p; break;
4860 		case 'r': *name++ = CAR; ++p; break;
4861 		case 't': *name++ = TAB; ++p; break;
4862 
4863 		case 'X': /* hex: "\x1", "\x12" */
4864 		case 'x':
4865 		case 'u': /* Unicode: "\u0023" */
4866 		case 'U':
4867 			  if (vim_isxdigit(p[1]))
4868 			  {
4869 			      int	n, nr;
4870 			      int	c = toupper(*p);
4871 
4872 			      if (c == 'X')
4873 				  n = 2;
4874 			      else if (*p == 'u')
4875 				  n = 4;
4876 			      else
4877 				  n = 8;
4878 			      nr = 0;
4879 			      while (--n >= 0 && vim_isxdigit(p[1]))
4880 			      {
4881 				  ++p;
4882 				  nr = (nr << 4) + hex2nr(*p);
4883 			      }
4884 			      ++p;
4885 #ifdef FEAT_MBYTE
4886 			      /* For "\u" store the number according to
4887 			       * 'encoding'. */
4888 			      if (c != 'X')
4889 				  name += (*mb_char2bytes)(nr, name);
4890 			      else
4891 #endif
4892 				  *name++ = nr;
4893 			  }
4894 			  break;
4895 
4896 			  /* octal: "\1", "\12", "\123" */
4897 		case '0':
4898 		case '1':
4899 		case '2':
4900 		case '3':
4901 		case '4':
4902 		case '5':
4903 		case '6':
4904 		case '7': *name = *p++ - '0';
4905 			  if (*p >= '0' && *p <= '7')
4906 			  {
4907 			      *name = (*name << 3) + *p++ - '0';
4908 			      if (*p >= '0' && *p <= '7')
4909 				  *name = (*name << 3) + *p++ - '0';
4910 			  }
4911 			  ++name;
4912 			  break;
4913 
4914 			    /* Special key, e.g.: "\<C-W>" */
4915 		case '<': extra = trans_special(&p, name, TRUE, TRUE);
4916 			  if (extra != 0)
4917 			  {
4918 			      name += extra;
4919 			      break;
4920 			  }
4921 			  /* FALLTHROUGH */
4922 
4923 		default:  MB_COPY_CHAR(p, name);
4924 			  break;
4925 	    }
4926 	}
4927 	else
4928 	    MB_COPY_CHAR(p, name);
4929 
4930     }
4931     *name = NUL;
4932     if (*p != NUL) /* just in case */
4933 	++p;
4934     *arg = p;
4935 
4936     return OK;
4937 }
4938 
4939 /*
4940  * Allocate a variable for a 'str''ing' constant.
4941  * Return OK or FAIL.
4942  */
4943     static int
4944 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
4945 {
4946     char_u	*p;
4947     char_u	*str;
4948     int		reduce = 0;
4949 
4950     /*
4951      * Find the end of the string, skipping ''.
4952      */
4953     for (p = *arg + 1; *p != NUL; MB_PTR_ADV(p))
4954     {
4955 	if (*p == '\'')
4956 	{
4957 	    if (p[1] != '\'')
4958 		break;
4959 	    ++reduce;
4960 	    ++p;
4961 	}
4962     }
4963 
4964     if (*p != '\'')
4965     {
4966 	EMSG2(_("E115: Missing quote: %s"), *arg);
4967 	return FAIL;
4968     }
4969 
4970     /* If only parsing return after setting "*arg" */
4971     if (!evaluate)
4972     {
4973 	*arg = p + 1;
4974 	return OK;
4975     }
4976 
4977     /*
4978      * Copy the string into allocated memory, handling '' to ' reduction.
4979      */
4980     str = alloc((unsigned)((p - *arg) - reduce));
4981     if (str == NULL)
4982 	return FAIL;
4983     rettv->v_type = VAR_STRING;
4984     rettv->vval.v_string = str;
4985 
4986     for (p = *arg + 1; *p != NUL; )
4987     {
4988 	if (*p == '\'')
4989 	{
4990 	    if (p[1] != '\'')
4991 		break;
4992 	    ++p;
4993 	}
4994 	MB_COPY_CHAR(p, str);
4995     }
4996     *str = NUL;
4997     *arg = p + 1;
4998 
4999     return OK;
5000 }
5001 
5002 /*
5003  * Return the function name of the partial.
5004  */
5005     char_u *
5006 partial_name(partial_T *pt)
5007 {
5008     if (pt->pt_name != NULL)
5009 	return pt->pt_name;
5010     return pt->pt_func->uf_name;
5011 }
5012 
5013     static void
5014 partial_free(partial_T *pt)
5015 {
5016     int i;
5017 
5018     for (i = 0; i < pt->pt_argc; ++i)
5019 	clear_tv(&pt->pt_argv[i]);
5020     vim_free(pt->pt_argv);
5021     dict_unref(pt->pt_dict);
5022     if (pt->pt_name != NULL)
5023     {
5024 	func_unref(pt->pt_name);
5025 	vim_free(pt->pt_name);
5026     }
5027     else
5028 	func_ptr_unref(pt->pt_func);
5029     vim_free(pt);
5030 }
5031 
5032 /*
5033  * Unreference a closure: decrement the reference count and free it when it
5034  * becomes zero.
5035  */
5036     void
5037 partial_unref(partial_T *pt)
5038 {
5039     if (pt != NULL && --pt->pt_refcount <= 0)
5040 	partial_free(pt);
5041 }
5042 
5043 static int tv_equal_recurse_limit;
5044 
5045     static int
5046 func_equal(
5047     typval_T *tv1,
5048     typval_T *tv2,
5049     int	     ic)	    /* ignore case */
5050 {
5051     char_u	*s1, *s2;
5052     dict_T	*d1, *d2;
5053     int		a1, a2;
5054     int		i;
5055 
5056     /* empty and NULL function name considered the same */
5057     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
5058 					   : partial_name(tv1->vval.v_partial);
5059     if (s1 != NULL && *s1 == NUL)
5060 	s1 = NULL;
5061     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
5062 					   : partial_name(tv2->vval.v_partial);
5063     if (s2 != NULL && *s2 == NUL)
5064 	s2 = NULL;
5065     if (s1 == NULL || s2 == NULL)
5066     {
5067 	if (s1 != s2)
5068 	    return FALSE;
5069     }
5070     else if (STRCMP(s1, s2) != 0)
5071 	return FALSE;
5072 
5073     /* empty dict and NULL dict is different */
5074     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
5075     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
5076     if (d1 == NULL || d2 == NULL)
5077     {
5078 	if (d1 != d2)
5079 	    return FALSE;
5080     }
5081     else if (!dict_equal(d1, d2, ic, TRUE))
5082 	return FALSE;
5083 
5084     /* empty list and no list considered the same */
5085     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
5086     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
5087     if (a1 != a2)
5088 	return FALSE;
5089     for (i = 0; i < a1; ++i)
5090 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
5091 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
5092 	    return FALSE;
5093 
5094     return TRUE;
5095 }
5096 
5097 /*
5098  * Return TRUE if "tv1" and "tv2" have the same value.
5099  * Compares the items just like "==" would compare them, but strings and
5100  * numbers are different.  Floats and numbers are also different.
5101  */
5102     int
5103 tv_equal(
5104     typval_T *tv1,
5105     typval_T *tv2,
5106     int	     ic,	    /* ignore case */
5107     int	     recursive)	    /* TRUE when used recursively */
5108 {
5109     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
5110     char_u	*s1, *s2;
5111     static int  recursive_cnt = 0;	    /* catch recursive loops */
5112     int		r;
5113 
5114     /* Catch lists and dicts that have an endless loop by limiting
5115      * recursiveness to a limit.  We guess they are equal then.
5116      * A fixed limit has the problem of still taking an awful long time.
5117      * Reduce the limit every time running into it. That should work fine for
5118      * deeply linked structures that are not recursively linked and catch
5119      * recursiveness quickly. */
5120     if (!recursive)
5121 	tv_equal_recurse_limit = 1000;
5122     if (recursive_cnt >= tv_equal_recurse_limit)
5123     {
5124 	--tv_equal_recurse_limit;
5125 	return TRUE;
5126     }
5127 
5128     /* For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
5129      * arguments. */
5130     if ((tv1->v_type == VAR_FUNC
5131 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
5132 	    && (tv2->v_type == VAR_FUNC
5133 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
5134     {
5135 	++recursive_cnt;
5136 	r = func_equal(tv1, tv2, ic);
5137 	--recursive_cnt;
5138 	return r;
5139     }
5140 
5141     if (tv1->v_type != tv2->v_type)
5142 	return FALSE;
5143 
5144     switch (tv1->v_type)
5145     {
5146 	case VAR_LIST:
5147 	    ++recursive_cnt;
5148 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
5149 	    --recursive_cnt;
5150 	    return r;
5151 
5152 	case VAR_DICT:
5153 	    ++recursive_cnt;
5154 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
5155 	    --recursive_cnt;
5156 	    return r;
5157 
5158 	case VAR_NUMBER:
5159 	    return tv1->vval.v_number == tv2->vval.v_number;
5160 
5161 	case VAR_STRING:
5162 	    s1 = get_tv_string_buf(tv1, buf1);
5163 	    s2 = get_tv_string_buf(tv2, buf2);
5164 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
5165 
5166 	case VAR_SPECIAL:
5167 	    return tv1->vval.v_number == tv2->vval.v_number;
5168 
5169 	case VAR_FLOAT:
5170 #ifdef FEAT_FLOAT
5171 	    return tv1->vval.v_float == tv2->vval.v_float;
5172 #endif
5173 	case VAR_JOB:
5174 #ifdef FEAT_JOB_CHANNEL
5175 	    return tv1->vval.v_job == tv2->vval.v_job;
5176 #endif
5177 	case VAR_CHANNEL:
5178 #ifdef FEAT_JOB_CHANNEL
5179 	    return tv1->vval.v_channel == tv2->vval.v_channel;
5180 #endif
5181 	case VAR_FUNC:
5182 	case VAR_PARTIAL:
5183 	case VAR_UNKNOWN:
5184 	    break;
5185     }
5186 
5187     /* VAR_UNKNOWN can be the result of a invalid expression, let's say it
5188      * does not equal anything, not even itself. */
5189     return FALSE;
5190 }
5191 
5192 /*
5193  * Return the next (unique) copy ID.
5194  * Used for serializing nested structures.
5195  */
5196     int
5197 get_copyID(void)
5198 {
5199     current_copyID += COPYID_INC;
5200     return current_copyID;
5201 }
5202 
5203 /*
5204  * Garbage collection for lists and dictionaries.
5205  *
5206  * We use reference counts to be able to free most items right away when they
5207  * are no longer used.  But for composite items it's possible that it becomes
5208  * unused while the reference count is > 0: When there is a recursive
5209  * reference.  Example:
5210  *	:let l = [1, 2, 3]
5211  *	:let d = {9: l}
5212  *	:let l[1] = d
5213  *
5214  * Since this is quite unusual we handle this with garbage collection: every
5215  * once in a while find out which lists and dicts are not referenced from any
5216  * variable.
5217  *
5218  * Here is a good reference text about garbage collection (refers to Python
5219  * but it applies to all reference-counting mechanisms):
5220  *	http://python.ca/nas/python/gc/
5221  */
5222 
5223 /*
5224  * Do garbage collection for lists and dicts.
5225  * When "testing" is TRUE this is called from test_garbagecollect_now().
5226  * Return TRUE if some memory was freed.
5227  */
5228     int
5229 garbage_collect(int testing)
5230 {
5231     int		copyID;
5232     int		abort = FALSE;
5233     buf_T	*buf;
5234     win_T	*wp;
5235     int		i;
5236     int		did_free = FALSE;
5237 #ifdef FEAT_WINDOWS
5238     tabpage_T	*tp;
5239 #endif
5240 
5241     if (!testing)
5242     {
5243 	/* Only do this once. */
5244 	want_garbage_collect = FALSE;
5245 	may_garbage_collect = FALSE;
5246 	garbage_collect_at_exit = FALSE;
5247     }
5248 
5249     /* We advance by two because we add one for items referenced through
5250      * previous_funccal. */
5251     copyID = get_copyID();
5252 
5253     /*
5254      * 1. Go through all accessible variables and mark all lists and dicts
5255      *    with copyID.
5256      */
5257 
5258     /* Don't free variables in the previous_funccal list unless they are only
5259      * referenced through previous_funccal.  This must be first, because if
5260      * the item is referenced elsewhere the funccal must not be freed. */
5261     abort = abort || set_ref_in_previous_funccal(copyID);
5262 
5263     /* script-local variables */
5264     for (i = 1; i <= ga_scripts.ga_len; ++i)
5265 	abort = abort || set_ref_in_ht(&SCRIPT_VARS(i), copyID, NULL);
5266 
5267     /* buffer-local variables */
5268     FOR_ALL_BUFFERS(buf)
5269 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
5270 								  NULL, NULL);
5271 
5272     /* window-local variables */
5273     FOR_ALL_TAB_WINDOWS(tp, wp)
5274 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
5275 								  NULL, NULL);
5276 #ifdef FEAT_AUTOCMD
5277     if (aucmd_win != NULL)
5278 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
5279 								  NULL, NULL);
5280 #endif
5281 
5282 #ifdef FEAT_WINDOWS
5283     /* tabpage-local variables */
5284     FOR_ALL_TABPAGES(tp)
5285 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
5286 								  NULL, NULL);
5287 #endif
5288 
5289     /* global variables */
5290     abort = abort || set_ref_in_ht(&globvarht, copyID, NULL);
5291 
5292     /* function-local variables */
5293     abort = abort || set_ref_in_call_stack(copyID);
5294 
5295     /* named functions (matters for closures) */
5296     abort = abort || set_ref_in_functions(copyID);
5297 
5298     /* function call arguments, if v:testing is set. */
5299     abort = abort || set_ref_in_func_args(copyID);
5300 
5301     /* v: vars */
5302     abort = abort || set_ref_in_ht(&vimvarht, copyID, NULL);
5303 
5304 #ifdef FEAT_LUA
5305     abort = abort || set_ref_in_lua(copyID);
5306 #endif
5307 
5308 #ifdef FEAT_PYTHON
5309     abort = abort || set_ref_in_python(copyID);
5310 #endif
5311 
5312 #ifdef FEAT_PYTHON3
5313     abort = abort || set_ref_in_python3(copyID);
5314 #endif
5315 
5316 #ifdef FEAT_JOB_CHANNEL
5317     abort = abort || set_ref_in_channel(copyID);
5318     abort = abort || set_ref_in_job(copyID);
5319 #endif
5320 #ifdef FEAT_NETBEANS_INTG
5321     abort = abort || set_ref_in_nb_channel(copyID);
5322 #endif
5323 
5324 #ifdef FEAT_TIMERS
5325     abort = abort || set_ref_in_timer(copyID);
5326 #endif
5327 
5328 #ifdef FEAT_QUICKFIX
5329     abort = abort || set_ref_in_quickfix(copyID);
5330 #endif
5331 
5332 #ifdef FEAT_TERMINAL
5333     abort = abort || set_ref_in_term(copyID);
5334 #endif
5335 
5336     if (!abort)
5337     {
5338 	/*
5339 	 * 2. Free lists and dictionaries that are not referenced.
5340 	 */
5341 	did_free = free_unref_items(copyID);
5342 
5343 	/*
5344 	 * 3. Check if any funccal can be freed now.
5345 	 *    This may call us back recursively.
5346 	 */
5347 	free_unref_funccal(copyID, testing);
5348     }
5349     else if (p_verbose > 0)
5350     {
5351 	verb_msg((char_u *)_("Not enough memory to set references, garbage collection aborted!"));
5352     }
5353 
5354     return did_free;
5355 }
5356 
5357 /*
5358  * Free lists, dictionaries, channels and jobs that are no longer referenced.
5359  */
5360     static int
5361 free_unref_items(int copyID)
5362 {
5363     int		did_free = FALSE;
5364 
5365     /* Let all "free" functions know that we are here.  This means no
5366      * dictionaries, lists, channels or jobs are to be freed, because we will
5367      * do that here. */
5368     in_free_unref_items = TRUE;
5369 
5370     /*
5371      * PASS 1: free the contents of the items.  We don't free the items
5372      * themselves yet, so that it is possible to decrement refcount counters
5373      */
5374 
5375     /* Go through the list of dicts and free items without the copyID. */
5376     did_free |= dict_free_nonref(copyID);
5377 
5378     /* Go through the list of lists and free items without the copyID. */
5379     did_free |= list_free_nonref(copyID);
5380 
5381 #ifdef FEAT_JOB_CHANNEL
5382     /* Go through the list of jobs and free items without the copyID. This
5383      * must happen before doing channels, because jobs refer to channels, but
5384      * the reference from the channel to the job isn't tracked. */
5385     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
5386 
5387     /* Go through the list of channels and free items without the copyID.  */
5388     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
5389 #endif
5390 
5391     /*
5392      * PASS 2: free the items themselves.
5393      */
5394     dict_free_items(copyID);
5395     list_free_items(copyID);
5396 
5397 #ifdef FEAT_JOB_CHANNEL
5398     /* Go through the list of jobs and free items without the copyID. This
5399      * must happen before doing channels, because jobs refer to channels, but
5400      * the reference from the channel to the job isn't tracked. */
5401     free_unused_jobs(copyID, COPYID_MASK);
5402 
5403     /* Go through the list of channels and free items without the copyID.  */
5404     free_unused_channels(copyID, COPYID_MASK);
5405 #endif
5406 
5407     in_free_unref_items = FALSE;
5408 
5409     return did_free;
5410 }
5411 
5412 /*
5413  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
5414  * "list_stack" is used to add lists to be marked.  Can be NULL.
5415  *
5416  * Returns TRUE if setting references failed somehow.
5417  */
5418     int
5419 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
5420 {
5421     int		todo;
5422     int		abort = FALSE;
5423     hashitem_T	*hi;
5424     hashtab_T	*cur_ht;
5425     ht_stack_T	*ht_stack = NULL;
5426     ht_stack_T	*tempitem;
5427 
5428     cur_ht = ht;
5429     for (;;)
5430     {
5431 	if (!abort)
5432 	{
5433 	    /* Mark each item in the hashtab.  If the item contains a hashtab
5434 	     * it is added to ht_stack, if it contains a list it is added to
5435 	     * list_stack. */
5436 	    todo = (int)cur_ht->ht_used;
5437 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
5438 		if (!HASHITEM_EMPTY(hi))
5439 		{
5440 		    --todo;
5441 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
5442 						       &ht_stack, list_stack);
5443 		}
5444 	}
5445 
5446 	if (ht_stack == NULL)
5447 	    break;
5448 
5449 	/* take an item from the stack */
5450 	cur_ht = ht_stack->ht;
5451 	tempitem = ht_stack;
5452 	ht_stack = ht_stack->prev;
5453 	free(tempitem);
5454     }
5455 
5456     return abort;
5457 }
5458 
5459 /*
5460  * Mark all lists and dicts referenced through list "l" with "copyID".
5461  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5462  *
5463  * Returns TRUE if setting references failed somehow.
5464  */
5465     int
5466 set_ref_in_list(list_T *l, int copyID, ht_stack_T **ht_stack)
5467 {
5468     listitem_T	 *li;
5469     int		 abort = FALSE;
5470     list_T	 *cur_l;
5471     list_stack_T *list_stack = NULL;
5472     list_stack_T *tempitem;
5473 
5474     cur_l = l;
5475     for (;;)
5476     {
5477 	if (!abort)
5478 	    /* Mark each item in the list.  If the item contains a hashtab
5479 	     * it is added to ht_stack, if it contains a list it is added to
5480 	     * list_stack. */
5481 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
5482 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
5483 						       ht_stack, &list_stack);
5484 	if (list_stack == NULL)
5485 	    break;
5486 
5487 	/* take an item from the stack */
5488 	cur_l = list_stack->list;
5489 	tempitem = list_stack;
5490 	list_stack = list_stack->prev;
5491 	free(tempitem);
5492     }
5493 
5494     return abort;
5495 }
5496 
5497 /*
5498  * Mark all lists and dicts referenced through typval "tv" with "copyID".
5499  * "list_stack" is used to add lists to be marked.  Can be NULL.
5500  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5501  *
5502  * Returns TRUE if setting references failed somehow.
5503  */
5504     int
5505 set_ref_in_item(
5506     typval_T	    *tv,
5507     int		    copyID,
5508     ht_stack_T	    **ht_stack,
5509     list_stack_T    **list_stack)
5510 {
5511     int		abort = FALSE;
5512 
5513     if (tv->v_type == VAR_DICT)
5514     {
5515 	dict_T	*dd = tv->vval.v_dict;
5516 
5517 	if (dd != NULL && dd->dv_copyID != copyID)
5518 	{
5519 	    /* Didn't see this dict yet. */
5520 	    dd->dv_copyID = copyID;
5521 	    if (ht_stack == NULL)
5522 	    {
5523 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
5524 	    }
5525 	    else
5526 	    {
5527 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
5528 		if (newitem == NULL)
5529 		    abort = TRUE;
5530 		else
5531 		{
5532 		    newitem->ht = &dd->dv_hashtab;
5533 		    newitem->prev = *ht_stack;
5534 		    *ht_stack = newitem;
5535 		}
5536 	    }
5537 	}
5538     }
5539     else if (tv->v_type == VAR_LIST)
5540     {
5541 	list_T	*ll = tv->vval.v_list;
5542 
5543 	if (ll != NULL && ll->lv_copyID != copyID)
5544 	{
5545 	    /* Didn't see this list yet. */
5546 	    ll->lv_copyID = copyID;
5547 	    if (list_stack == NULL)
5548 	    {
5549 		abort = set_ref_in_list(ll, copyID, ht_stack);
5550 	    }
5551 	    else
5552 	    {
5553 		list_stack_T *newitem = (list_stack_T*)malloc(
5554 							sizeof(list_stack_T));
5555 		if (newitem == NULL)
5556 		    abort = TRUE;
5557 		else
5558 		{
5559 		    newitem->list = ll;
5560 		    newitem->prev = *list_stack;
5561 		    *list_stack = newitem;
5562 		}
5563 	    }
5564 	}
5565     }
5566     else if (tv->v_type == VAR_FUNC)
5567     {
5568 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
5569     }
5570     else if (tv->v_type == VAR_PARTIAL)
5571     {
5572 	partial_T	*pt = tv->vval.v_partial;
5573 	int		i;
5574 
5575 	/* A partial does not have a copyID, because it cannot contain itself.
5576 	 */
5577 	if (pt != NULL)
5578 	{
5579 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
5580 
5581 	    if (pt->pt_dict != NULL)
5582 	    {
5583 		typval_T dtv;
5584 
5585 		dtv.v_type = VAR_DICT;
5586 		dtv.vval.v_dict = pt->pt_dict;
5587 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5588 	    }
5589 
5590 	    for (i = 0; i < pt->pt_argc; ++i)
5591 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
5592 							ht_stack, list_stack);
5593 	}
5594     }
5595 #ifdef FEAT_JOB_CHANNEL
5596     else if (tv->v_type == VAR_JOB)
5597     {
5598 	job_T	    *job = tv->vval.v_job;
5599 	typval_T    dtv;
5600 
5601 	if (job != NULL && job->jv_copyID != copyID)
5602 	{
5603 	    job->jv_copyID = copyID;
5604 	    if (job->jv_channel != NULL)
5605 	    {
5606 		dtv.v_type = VAR_CHANNEL;
5607 		dtv.vval.v_channel = job->jv_channel;
5608 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5609 	    }
5610 	    if (job->jv_exit_partial != NULL)
5611 	    {
5612 		dtv.v_type = VAR_PARTIAL;
5613 		dtv.vval.v_partial = job->jv_exit_partial;
5614 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5615 	    }
5616 	}
5617     }
5618     else if (tv->v_type == VAR_CHANNEL)
5619     {
5620 	channel_T   *ch =tv->vval.v_channel;
5621 	ch_part_T   part;
5622 	typval_T    dtv;
5623 	jsonq_T	    *jq;
5624 	cbq_T	    *cq;
5625 
5626 	if (ch != NULL && ch->ch_copyID != copyID)
5627 	{
5628 	    ch->ch_copyID = copyID;
5629 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
5630 	    {
5631 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
5632 							     jq = jq->jq_next)
5633 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
5634 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
5635 							     cq = cq->cq_next)
5636 		    if (cq->cq_partial != NULL)
5637 		    {
5638 			dtv.v_type = VAR_PARTIAL;
5639 			dtv.vval.v_partial = cq->cq_partial;
5640 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5641 		    }
5642 		if (ch->ch_part[part].ch_partial != NULL)
5643 		{
5644 		    dtv.v_type = VAR_PARTIAL;
5645 		    dtv.vval.v_partial = ch->ch_part[part].ch_partial;
5646 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5647 		}
5648 	    }
5649 	    if (ch->ch_partial != NULL)
5650 	    {
5651 		dtv.v_type = VAR_PARTIAL;
5652 		dtv.vval.v_partial = ch->ch_partial;
5653 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5654 	    }
5655 	    if (ch->ch_close_partial != NULL)
5656 	    {
5657 		dtv.v_type = VAR_PARTIAL;
5658 		dtv.vval.v_partial = ch->ch_close_partial;
5659 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5660 	    }
5661 	}
5662     }
5663 #endif
5664     return abort;
5665 }
5666 
5667     static char *
5668 get_var_special_name(int nr)
5669 {
5670     switch (nr)
5671     {
5672 	case VVAL_FALSE: return "v:false";
5673 	case VVAL_TRUE:  return "v:true";
5674 	case VVAL_NONE:  return "v:none";
5675 	case VVAL_NULL:  return "v:null";
5676     }
5677     internal_error("get_var_special_name()");
5678     return "42";
5679 }
5680 
5681 /*
5682  * Return a string with the string representation of a variable.
5683  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5684  * "numbuf" is used for a number.
5685  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5686  * When both "echo_style" and "composite_val" are FALSE, put quotes around
5687  * stings as "string()", otherwise does not put quotes around strings, as
5688  * ":echo" displays values.
5689  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
5690  * are replaced with "...".
5691  * May return NULL.
5692  */
5693     char_u *
5694 echo_string_core(
5695     typval_T	*tv,
5696     char_u	**tofree,
5697     char_u	*numbuf,
5698     int		copyID,
5699     int		echo_style,
5700     int		restore_copyID,
5701     int		composite_val)
5702 {
5703     static int	recurse = 0;
5704     char_u	*r = NULL;
5705 
5706     if (recurse >= DICT_MAXNEST)
5707     {
5708 	if (!did_echo_string_emsg)
5709 	{
5710 	    /* Only give this message once for a recursive call to avoid
5711 	     * flooding the user with errors.  And stop iterating over lists
5712 	     * and dicts. */
5713 	    did_echo_string_emsg = TRUE;
5714 	    EMSG(_("E724: variable nested too deep for displaying"));
5715 	}
5716 	*tofree = NULL;
5717 	return (char_u *)"{E724}";
5718     }
5719     ++recurse;
5720 
5721     switch (tv->v_type)
5722     {
5723 	case VAR_STRING:
5724 	    if (echo_style && !composite_val)
5725 	    {
5726 		*tofree = NULL;
5727 		r = tv->vval.v_string;
5728 		if (r == NULL)
5729 		    r = (char_u *)"";
5730 	    }
5731 	    else
5732 	    {
5733 		*tofree = string_quote(tv->vval.v_string, FALSE);
5734 		r = *tofree;
5735 	    }
5736 	    break;
5737 
5738 	case VAR_FUNC:
5739 	    if (echo_style)
5740 	    {
5741 		*tofree = NULL;
5742 		r = tv->vval.v_string;
5743 	    }
5744 	    else
5745 	    {
5746 		*tofree = string_quote(tv->vval.v_string, TRUE);
5747 		r = *tofree;
5748 	    }
5749 	    break;
5750 
5751 	case VAR_PARTIAL:
5752 	    {
5753 		partial_T   *pt = tv->vval.v_partial;
5754 		char_u	    *fname = string_quote(pt == NULL ? NULL
5755 						    : partial_name(pt), FALSE);
5756 		garray_T    ga;
5757 		int	    i;
5758 		char_u	    *tf;
5759 
5760 		ga_init2(&ga, 1, 100);
5761 		ga_concat(&ga, (char_u *)"function(");
5762 		if (fname != NULL)
5763 		{
5764 		    ga_concat(&ga, fname);
5765 		    vim_free(fname);
5766 		}
5767 		if (pt != NULL && pt->pt_argc > 0)
5768 		{
5769 		    ga_concat(&ga, (char_u *)", [");
5770 		    for (i = 0; i < pt->pt_argc; ++i)
5771 		    {
5772 			if (i > 0)
5773 			    ga_concat(&ga, (char_u *)", ");
5774 			ga_concat(&ga,
5775 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
5776 			vim_free(tf);
5777 		    }
5778 		    ga_concat(&ga, (char_u *)"]");
5779 		}
5780 		if (pt != NULL && pt->pt_dict != NULL)
5781 		{
5782 		    typval_T dtv;
5783 
5784 		    ga_concat(&ga, (char_u *)", ");
5785 		    dtv.v_type = VAR_DICT;
5786 		    dtv.vval.v_dict = pt->pt_dict;
5787 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
5788 		    vim_free(tf);
5789 		}
5790 		ga_concat(&ga, (char_u *)")");
5791 
5792 		*tofree = ga.ga_data;
5793 		r = *tofree;
5794 		break;
5795 	    }
5796 
5797 	case VAR_LIST:
5798 	    if (tv->vval.v_list == NULL)
5799 	    {
5800 		*tofree = NULL;
5801 		r = NULL;
5802 	    }
5803 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
5804 		    && tv->vval.v_list->lv_len > 0)
5805 	    {
5806 		*tofree = NULL;
5807 		r = (char_u *)"[...]";
5808 	    }
5809 	    else
5810 	    {
5811 		int old_copyID = tv->vval.v_list->lv_copyID;
5812 
5813 		tv->vval.v_list->lv_copyID = copyID;
5814 		*tofree = list2string(tv, copyID, restore_copyID);
5815 		if (restore_copyID)
5816 		    tv->vval.v_list->lv_copyID = old_copyID;
5817 		r = *tofree;
5818 	    }
5819 	    break;
5820 
5821 	case VAR_DICT:
5822 	    if (tv->vval.v_dict == NULL)
5823 	    {
5824 		*tofree = NULL;
5825 		r = NULL;
5826 	    }
5827 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
5828 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
5829 	    {
5830 		*tofree = NULL;
5831 		r = (char_u *)"{...}";
5832 	    }
5833 	    else
5834 	    {
5835 		int old_copyID = tv->vval.v_dict->dv_copyID;
5836 		tv->vval.v_dict->dv_copyID = copyID;
5837 		*tofree = dict2string(tv, copyID, restore_copyID);
5838 		if (restore_copyID)
5839 		    tv->vval.v_dict->dv_copyID = old_copyID;
5840 		r = *tofree;
5841 	    }
5842 	    break;
5843 
5844 	case VAR_NUMBER:
5845 	case VAR_UNKNOWN:
5846 	    *tofree = NULL;
5847 	    r = get_tv_string_buf(tv, numbuf);
5848 	    break;
5849 
5850 	case VAR_JOB:
5851 	case VAR_CHANNEL:
5852 	    *tofree = NULL;
5853 	    r = get_tv_string_buf(tv, numbuf);
5854 	    if (composite_val)
5855 	    {
5856 		*tofree = string_quote(r, FALSE);
5857 		r = *tofree;
5858 	    }
5859 	    break;
5860 
5861 	case VAR_FLOAT:
5862 #ifdef FEAT_FLOAT
5863 	    *tofree = NULL;
5864 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
5865 	    r = numbuf;
5866 	    break;
5867 #endif
5868 
5869 	case VAR_SPECIAL:
5870 	    *tofree = NULL;
5871 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
5872 	    break;
5873     }
5874 
5875     if (--recurse == 0)
5876 	did_echo_string_emsg = FALSE;
5877     return r;
5878 }
5879 
5880 /*
5881  * Return a string with the string representation of a variable.
5882  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5883  * "numbuf" is used for a number.
5884  * Does not put quotes around strings, as ":echo" displays values.
5885  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5886  * May return NULL.
5887  */
5888     char_u *
5889 echo_string(
5890     typval_T	*tv,
5891     char_u	**tofree,
5892     char_u	*numbuf,
5893     int		copyID)
5894 {
5895     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
5896 }
5897 
5898 /*
5899  * Return a string with the string representation of a variable.
5900  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5901  * "numbuf" is used for a number.
5902  * Puts quotes around strings, so that they can be parsed back by eval().
5903  * May return NULL.
5904  */
5905     char_u *
5906 tv2string(
5907     typval_T	*tv,
5908     char_u	**tofree,
5909     char_u	*numbuf,
5910     int		copyID)
5911 {
5912     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
5913 }
5914 
5915 /*
5916  * Return string "str" in ' quotes, doubling ' characters.
5917  * If "str" is NULL an empty string is assumed.
5918  * If "function" is TRUE make it function('string').
5919  */
5920     char_u *
5921 string_quote(char_u *str, int function)
5922 {
5923     unsigned	len;
5924     char_u	*p, *r, *s;
5925 
5926     len = (function ? 13 : 3);
5927     if (str != NULL)
5928     {
5929 	len += (unsigned)STRLEN(str);
5930 	for (p = str; *p != NUL; MB_PTR_ADV(p))
5931 	    if (*p == '\'')
5932 		++len;
5933     }
5934     s = r = alloc(len);
5935     if (r != NULL)
5936     {
5937 	if (function)
5938 	{
5939 	    STRCPY(r, "function('");
5940 	    r += 10;
5941 	}
5942 	else
5943 	    *r++ = '\'';
5944 	if (str != NULL)
5945 	    for (p = str; *p != NUL; )
5946 	    {
5947 		if (*p == '\'')
5948 		    *r++ = '\'';
5949 		MB_COPY_CHAR(p, r);
5950 	    }
5951 	*r++ = '\'';
5952 	if (function)
5953 	    *r++ = ')';
5954 	*r++ = NUL;
5955     }
5956     return s;
5957 }
5958 
5959 #if defined(FEAT_FLOAT) || defined(PROTO)
5960 /*
5961  * Convert the string "text" to a floating point number.
5962  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
5963  * this always uses a decimal point.
5964  * Returns the length of the text that was consumed.
5965  */
5966     int
5967 string2float(
5968     char_u	*text,
5969     float_T	*value)	    /* result stored here */
5970 {
5971     char	*s = (char *)text;
5972     float_T	f;
5973 
5974     /* MS-Windows does not deal with "inf" and "nan" properly. */
5975     if (STRNICMP(text, "inf", 3) == 0)
5976     {
5977 	*value = INFINITY;
5978 	return 3;
5979     }
5980     if (STRNICMP(text, "-inf", 3) == 0)
5981     {
5982 	*value = -INFINITY;
5983 	return 4;
5984     }
5985     if (STRNICMP(text, "nan", 3) == 0)
5986     {
5987 	*value = NAN;
5988 	return 3;
5989     }
5990     f = strtod(s, &s);
5991     *value = f;
5992     return (int)((char_u *)s - text);
5993 }
5994 #endif
5995 
5996 /*
5997  * Get the value of an environment variable.
5998  * "arg" is pointing to the '$'.  It is advanced to after the name.
5999  * If the environment variable was not set, silently assume it is empty.
6000  * Return FAIL if the name is invalid.
6001  */
6002     static int
6003 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
6004 {
6005     char_u	*string = NULL;
6006     int		len;
6007     int		cc;
6008     char_u	*name;
6009     int		mustfree = FALSE;
6010 
6011     ++*arg;
6012     name = *arg;
6013     len = get_env_len(arg);
6014     if (evaluate)
6015     {
6016 	if (len == 0)
6017 	    return FAIL; /* invalid empty name */
6018 
6019 	cc = name[len];
6020 	name[len] = NUL;
6021 	/* first try vim_getenv(), fast for normal environment vars */
6022 	string = vim_getenv(name, &mustfree);
6023 	if (string != NULL && *string != NUL)
6024 	{
6025 	    if (!mustfree)
6026 		string = vim_strsave(string);
6027 	}
6028 	else
6029 	{
6030 	    if (mustfree)
6031 		vim_free(string);
6032 
6033 	    /* next try expanding things like $VIM and ${HOME} */
6034 	    string = expand_env_save(name - 1);
6035 	    if (string != NULL && *string == '$')
6036 	    {
6037 		vim_free(string);
6038 		string = NULL;
6039 	    }
6040 	}
6041 	name[len] = cc;
6042 
6043 	rettv->v_type = VAR_STRING;
6044 	rettv->vval.v_string = string;
6045     }
6046 
6047     return OK;
6048 }
6049 
6050 
6051 
6052 /*
6053  * Translate a String variable into a position.
6054  * Returns NULL when there is an error.
6055  */
6056     pos_T *
6057 var2fpos(
6058     typval_T	*varp,
6059     int		dollar_lnum,	/* TRUE when $ is last line */
6060     int		*fnum)		/* set to fnum for '0, 'A, etc. */
6061 {
6062     char_u		*name;
6063     static pos_T	pos;
6064     pos_T		*pp;
6065 
6066     /* Argument can be [lnum, col, coladd]. */
6067     if (varp->v_type == VAR_LIST)
6068     {
6069 	list_T		*l;
6070 	int		len;
6071 	int		error = FALSE;
6072 	listitem_T	*li;
6073 
6074 	l = varp->vval.v_list;
6075 	if (l == NULL)
6076 	    return NULL;
6077 
6078 	/* Get the line number */
6079 	pos.lnum = list_find_nr(l, 0L, &error);
6080 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
6081 	    return NULL;	/* invalid line number */
6082 
6083 	/* Get the column number */
6084 	pos.col = list_find_nr(l, 1L, &error);
6085 	if (error)
6086 	    return NULL;
6087 	len = (long)STRLEN(ml_get(pos.lnum));
6088 
6089 	/* We accept "$" for the column number: last column. */
6090 	li = list_find(l, 1L);
6091 	if (li != NULL && li->li_tv.v_type == VAR_STRING
6092 		&& li->li_tv.vval.v_string != NULL
6093 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
6094 	    pos.col = len + 1;
6095 
6096 	/* Accept a position up to the NUL after the line. */
6097 	if (pos.col == 0 || (int)pos.col > len + 1)
6098 	    return NULL;	/* invalid column number */
6099 	--pos.col;
6100 
6101 #ifdef FEAT_VIRTUALEDIT
6102 	/* Get the virtual offset.  Defaults to zero. */
6103 	pos.coladd = list_find_nr(l, 2L, &error);
6104 	if (error)
6105 	    pos.coladd = 0;
6106 #endif
6107 
6108 	return &pos;
6109     }
6110 
6111     name = get_tv_string_chk(varp);
6112     if (name == NULL)
6113 	return NULL;
6114     if (name[0] == '.')				/* cursor */
6115 	return &curwin->w_cursor;
6116     if (name[0] == 'v' && name[1] == NUL)	/* Visual start */
6117     {
6118 	if (VIsual_active)
6119 	    return &VIsual;
6120 	return &curwin->w_cursor;
6121     }
6122     if (name[0] == '\'')			/* mark */
6123     {
6124 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
6125 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
6126 	    return NULL;
6127 	return pp;
6128     }
6129 
6130 #ifdef FEAT_VIRTUALEDIT
6131     pos.coladd = 0;
6132 #endif
6133 
6134     if (name[0] == 'w' && dollar_lnum)
6135     {
6136 	pos.col = 0;
6137 	if (name[1] == '0')		/* "w0": first visible line */
6138 	{
6139 	    update_topline();
6140 	    /* In silent Ex mode topline is zero, but that's not a valid line
6141 	     * number; use one instead. */
6142 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
6143 	    return &pos;
6144 	}
6145 	else if (name[1] == '$')	/* "w$": last visible line */
6146 	{
6147 	    validate_botline();
6148 	    /* In silent Ex mode botline is zero, return zero then. */
6149 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
6150 	    return &pos;
6151 	}
6152     }
6153     else if (name[0] == '$')		/* last column or line */
6154     {
6155 	if (dollar_lnum)
6156 	{
6157 	    pos.lnum = curbuf->b_ml.ml_line_count;
6158 	    pos.col = 0;
6159 	}
6160 	else
6161 	{
6162 	    pos.lnum = curwin->w_cursor.lnum;
6163 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
6164 	}
6165 	return &pos;
6166     }
6167     return NULL;
6168 }
6169 
6170 /*
6171  * Convert list in "arg" into a position and optional file number.
6172  * When "fnump" is NULL there is no file number, only 3 items.
6173  * Note that the column is passed on as-is, the caller may want to decrement
6174  * it to use 1 for the first column.
6175  * Return FAIL when conversion is not possible, doesn't check the position for
6176  * validity.
6177  */
6178     int
6179 list2fpos(
6180     typval_T	*arg,
6181     pos_T	*posp,
6182     int		*fnump,
6183     colnr_T	*curswantp)
6184 {
6185     list_T	*l = arg->vval.v_list;
6186     long	i = 0;
6187     long	n;
6188 
6189     /* List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
6190      * there when "fnump" isn't NULL; "coladd" and "curswant" are optional. */
6191     if (arg->v_type != VAR_LIST
6192 	    || l == NULL
6193 	    || l->lv_len < (fnump == NULL ? 2 : 3)
6194 	    || l->lv_len > (fnump == NULL ? 4 : 5))
6195 	return FAIL;
6196 
6197     if (fnump != NULL)
6198     {
6199 	n = list_find_nr(l, i++, NULL);	/* fnum */
6200 	if (n < 0)
6201 	    return FAIL;
6202 	if (n == 0)
6203 	    n = curbuf->b_fnum;		/* current buffer */
6204 	*fnump = n;
6205     }
6206 
6207     n = list_find_nr(l, i++, NULL);	/* lnum */
6208     if (n < 0)
6209 	return FAIL;
6210     posp->lnum = n;
6211 
6212     n = list_find_nr(l, i++, NULL);	/* col */
6213     if (n < 0)
6214 	return FAIL;
6215     posp->col = n;
6216 
6217 #ifdef FEAT_VIRTUALEDIT
6218     n = list_find_nr(l, i, NULL);	/* off */
6219     if (n < 0)
6220 	posp->coladd = 0;
6221     else
6222 	posp->coladd = n;
6223 #endif
6224 
6225     if (curswantp != NULL)
6226 	*curswantp = list_find_nr(l, i + 1, NULL);  /* curswant */
6227 
6228     return OK;
6229 }
6230 
6231 /*
6232  * Get the length of an environment variable name.
6233  * Advance "arg" to the first character after the name.
6234  * Return 0 for error.
6235  */
6236     static int
6237 get_env_len(char_u **arg)
6238 {
6239     char_u	*p;
6240     int		len;
6241 
6242     for (p = *arg; vim_isIDc(*p); ++p)
6243 	;
6244     if (p == *arg)	    /* no name found */
6245 	return 0;
6246 
6247     len = (int)(p - *arg);
6248     *arg = p;
6249     return len;
6250 }
6251 
6252 /*
6253  * Get the length of the name of a function or internal variable.
6254  * "arg" is advanced to the first non-white character after the name.
6255  * Return 0 if something is wrong.
6256  */
6257     int
6258 get_id_len(char_u **arg)
6259 {
6260     char_u	*p;
6261     int		len;
6262 
6263     /* Find the end of the name. */
6264     for (p = *arg; eval_isnamec(*p); ++p)
6265     {
6266 	if (*p == ':')
6267 	{
6268 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6269 	     * slice "[n:]".  Also "xx:" is not a namespace. */
6270 	    len = (int)(p - *arg);
6271 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
6272 		    || len > 1)
6273 		break;
6274 	}
6275     }
6276     if (p == *arg)	    /* no name found */
6277 	return 0;
6278 
6279     len = (int)(p - *arg);
6280     *arg = skipwhite(p);
6281 
6282     return len;
6283 }
6284 
6285 /*
6286  * Get the length of the name of a variable or function.
6287  * Only the name is recognized, does not handle ".key" or "[idx]".
6288  * "arg" is advanced to the first non-white character after the name.
6289  * Return -1 if curly braces expansion failed.
6290  * Return 0 if something else is wrong.
6291  * If the name contains 'magic' {}'s, expand them and return the
6292  * expanded name in an allocated string via 'alias' - caller must free.
6293  */
6294     int
6295 get_name_len(
6296     char_u	**arg,
6297     char_u	**alias,
6298     int		evaluate,
6299     int		verbose)
6300 {
6301     int		len;
6302     char_u	*p;
6303     char_u	*expr_start;
6304     char_u	*expr_end;
6305 
6306     *alias = NULL;  /* default to no alias */
6307 
6308     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
6309 						  && (*arg)[2] == (int)KE_SNR)
6310     {
6311 	/* hard coded <SNR>, already translated */
6312 	*arg += 3;
6313 	return get_id_len(arg) + 3;
6314     }
6315     len = eval_fname_script(*arg);
6316     if (len > 0)
6317     {
6318 	/* literal "<SID>", "s:" or "<SNR>" */
6319 	*arg += len;
6320     }
6321 
6322     /*
6323      * Find the end of the name; check for {} construction.
6324      */
6325     p = find_name_end(*arg, &expr_start, &expr_end,
6326 					       len > 0 ? 0 : FNE_CHECK_START);
6327     if (expr_start != NULL)
6328     {
6329 	char_u	*temp_string;
6330 
6331 	if (!evaluate)
6332 	{
6333 	    len += (int)(p - *arg);
6334 	    *arg = skipwhite(p);
6335 	    return len;
6336 	}
6337 
6338 	/*
6339 	 * Include any <SID> etc in the expanded string:
6340 	 * Thus the -len here.
6341 	 */
6342 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
6343 	if (temp_string == NULL)
6344 	    return -1;
6345 	*alias = temp_string;
6346 	*arg = skipwhite(p);
6347 	return (int)STRLEN(temp_string);
6348     }
6349 
6350     len += get_id_len(arg);
6351     if (len == 0 && verbose)
6352 	EMSG2(_(e_invexpr2), *arg);
6353 
6354     return len;
6355 }
6356 
6357 /*
6358  * Find the end of a variable or function name, taking care of magic braces.
6359  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
6360  * start and end of the first magic braces item.
6361  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
6362  * Return a pointer to just after the name.  Equal to "arg" if there is no
6363  * valid name.
6364  */
6365     char_u *
6366 find_name_end(
6367     char_u	*arg,
6368     char_u	**expr_start,
6369     char_u	**expr_end,
6370     int		flags)
6371 {
6372     int		mb_nest = 0;
6373     int		br_nest = 0;
6374     char_u	*p;
6375     int		len;
6376 
6377     if (expr_start != NULL)
6378     {
6379 	*expr_start = NULL;
6380 	*expr_end = NULL;
6381     }
6382 
6383     /* Quick check for valid starting character. */
6384     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg) && *arg != '{')
6385 	return arg;
6386 
6387     for (p = arg; *p != NUL
6388 		    && (eval_isnamec(*p)
6389 			|| *p == '{'
6390 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
6391 			|| mb_nest != 0
6392 			|| br_nest != 0); MB_PTR_ADV(p))
6393     {
6394 	if (*p == '\'')
6395 	{
6396 	    /* skip over 'string' to avoid counting [ and ] inside it. */
6397 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
6398 		;
6399 	    if (*p == NUL)
6400 		break;
6401 	}
6402 	else if (*p == '"')
6403 	{
6404 	    /* skip over "str\"ing" to avoid counting [ and ] inside it. */
6405 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
6406 		if (*p == '\\' && p[1] != NUL)
6407 		    ++p;
6408 	    if (*p == NUL)
6409 		break;
6410 	}
6411 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
6412 	{
6413 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6414 	     * slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is. */
6415 	    len = (int)(p - arg);
6416 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
6417 		    || (len > 1 && p[-1] != '}'))
6418 		break;
6419 	}
6420 
6421 	if (mb_nest == 0)
6422 	{
6423 	    if (*p == '[')
6424 		++br_nest;
6425 	    else if (*p == ']')
6426 		--br_nest;
6427 	}
6428 
6429 	if (br_nest == 0)
6430 	{
6431 	    if (*p == '{')
6432 	    {
6433 		mb_nest++;
6434 		if (expr_start != NULL && *expr_start == NULL)
6435 		    *expr_start = p;
6436 	    }
6437 	    else if (*p == '}')
6438 	    {
6439 		mb_nest--;
6440 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
6441 		    *expr_end = p;
6442 	    }
6443 	}
6444     }
6445 
6446     return p;
6447 }
6448 
6449 /*
6450  * Expands out the 'magic' {}'s in a variable/function name.
6451  * Note that this can call itself recursively, to deal with
6452  * constructs like foo{bar}{baz}{bam}
6453  * The four pointer arguments point to "foo{expre}ss{ion}bar"
6454  *			"in_start"      ^
6455  *			"expr_start"	   ^
6456  *			"expr_end"		 ^
6457  *			"in_end"			    ^
6458  *
6459  * Returns a new allocated string, which the caller must free.
6460  * Returns NULL for failure.
6461  */
6462     static char_u *
6463 make_expanded_name(
6464     char_u	*in_start,
6465     char_u	*expr_start,
6466     char_u	*expr_end,
6467     char_u	*in_end)
6468 {
6469     char_u	c1;
6470     char_u	*retval = NULL;
6471     char_u	*temp_result;
6472     char_u	*nextcmd = NULL;
6473 
6474     if (expr_end == NULL || in_end == NULL)
6475 	return NULL;
6476     *expr_start	= NUL;
6477     *expr_end = NUL;
6478     c1 = *in_end;
6479     *in_end = NUL;
6480 
6481     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
6482     if (temp_result != NULL && nextcmd == NULL)
6483     {
6484 	retval = alloc((unsigned)(STRLEN(temp_result) + (expr_start - in_start)
6485 						   + (in_end - expr_end) + 1));
6486 	if (retval != NULL)
6487 	{
6488 	    STRCPY(retval, in_start);
6489 	    STRCAT(retval, temp_result);
6490 	    STRCAT(retval, expr_end + 1);
6491 	}
6492     }
6493     vim_free(temp_result);
6494 
6495     *in_end = c1;		/* put char back for error messages */
6496     *expr_start = '{';
6497     *expr_end = '}';
6498 
6499     if (retval != NULL)
6500     {
6501 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
6502 	if (expr_start != NULL)
6503 	{
6504 	    /* Further expansion! */
6505 	    temp_result = make_expanded_name(retval, expr_start,
6506 						       expr_end, temp_result);
6507 	    vim_free(retval);
6508 	    retval = temp_result;
6509 	}
6510     }
6511 
6512     return retval;
6513 }
6514 
6515 /*
6516  * Return TRUE if character "c" can be used in a variable or function name.
6517  * Does not include '{' or '}' for magic braces.
6518  */
6519     int
6520 eval_isnamec(int c)
6521 {
6522     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
6523 }
6524 
6525 /*
6526  * Return TRUE if character "c" can be used as the first character in a
6527  * variable or function name (excluding '{' and '}').
6528  */
6529     int
6530 eval_isnamec1(int c)
6531 {
6532     return (ASCII_ISALPHA(c) || c == '_');
6533 }
6534 
6535 /*
6536  * Set number v: variable to "val".
6537  */
6538     void
6539 set_vim_var_nr(int idx, varnumber_T val)
6540 {
6541     vimvars[idx].vv_nr = val;
6542 }
6543 
6544 /*
6545  * Get number v: variable value.
6546  */
6547     varnumber_T
6548 get_vim_var_nr(int idx)
6549 {
6550     return vimvars[idx].vv_nr;
6551 }
6552 
6553 /*
6554  * Get string v: variable value.  Uses a static buffer, can only be used once.
6555  */
6556     char_u *
6557 get_vim_var_str(int idx)
6558 {
6559     return get_tv_string(&vimvars[idx].vv_tv);
6560 }
6561 
6562 /*
6563  * Get List v: variable value.  Caller must take care of reference count when
6564  * needed.
6565  */
6566     list_T *
6567 get_vim_var_list(int idx)
6568 {
6569     return vimvars[idx].vv_list;
6570 }
6571 
6572 /*
6573  * Set v:char to character "c".
6574  */
6575     void
6576 set_vim_var_char(int c)
6577 {
6578     char_u	buf[MB_MAXBYTES + 1];
6579 
6580 #ifdef FEAT_MBYTE
6581     if (has_mbyte)
6582 	buf[(*mb_char2bytes)(c, buf)] = NUL;
6583     else
6584 #endif
6585     {
6586 	buf[0] = c;
6587 	buf[1] = NUL;
6588     }
6589     set_vim_var_string(VV_CHAR, buf, -1);
6590 }
6591 
6592 /*
6593  * Set v:count to "count" and v:count1 to "count1".
6594  * When "set_prevcount" is TRUE first set v:prevcount from v:count.
6595  */
6596     void
6597 set_vcount(
6598     long	count,
6599     long	count1,
6600     int		set_prevcount)
6601 {
6602     if (set_prevcount)
6603 	vimvars[VV_PREVCOUNT].vv_nr = vimvars[VV_COUNT].vv_nr;
6604     vimvars[VV_COUNT].vv_nr = count;
6605     vimvars[VV_COUNT1].vv_nr = count1;
6606 }
6607 
6608 /*
6609  * Set string v: variable to a copy of "val".
6610  */
6611     void
6612 set_vim_var_string(
6613     int		idx,
6614     char_u	*val,
6615     int		len)	    /* length of "val" to use or -1 (whole string) */
6616 {
6617     clear_tv(&vimvars[idx].vv_di.di_tv);
6618     vimvars[idx].vv_type = VAR_STRING;
6619     if (val == NULL)
6620 	vimvars[idx].vv_str = NULL;
6621     else if (len == -1)
6622 	vimvars[idx].vv_str = vim_strsave(val);
6623     else
6624 	vimvars[idx].vv_str = vim_strnsave(val, len);
6625 }
6626 
6627 /*
6628  * Set List v: variable to "val".
6629  */
6630     void
6631 set_vim_var_list(int idx, list_T *val)
6632 {
6633     clear_tv(&vimvars[idx].vv_di.di_tv);
6634     vimvars[idx].vv_type = VAR_LIST;
6635     vimvars[idx].vv_list = val;
6636     if (val != NULL)
6637 	++val->lv_refcount;
6638 }
6639 
6640 /*
6641  * Set Dictionary v: variable to "val".
6642  */
6643     void
6644 set_vim_var_dict(int idx, dict_T *val)
6645 {
6646     int		todo;
6647     hashitem_T	*hi;
6648 
6649     clear_tv(&vimvars[idx].vv_di.di_tv);
6650     vimvars[idx].vv_type = VAR_DICT;
6651     vimvars[idx].vv_dict = val;
6652     if (val != NULL)
6653     {
6654 	++val->dv_refcount;
6655 
6656 	/* Set readonly */
6657 	todo = (int)val->dv_hashtab.ht_used;
6658 	for (hi = val->dv_hashtab.ht_array; todo > 0 ; ++hi)
6659 	{
6660 	    if (HASHITEM_EMPTY(hi))
6661 		continue;
6662 	    --todo;
6663 	    HI2DI(hi)->di_flags |= DI_FLAGS_RO | DI_FLAGS_FIX;
6664 	}
6665     }
6666 }
6667 
6668 /*
6669  * Set v:register if needed.
6670  */
6671     void
6672 set_reg_var(int c)
6673 {
6674     char_u	regname;
6675 
6676     if (c == 0 || c == ' ')
6677 	regname = '"';
6678     else
6679 	regname = c;
6680     /* Avoid free/alloc when the value is already right. */
6681     if (vimvars[VV_REG].vv_str == NULL || vimvars[VV_REG].vv_str[0] != c)
6682 	set_vim_var_string(VV_REG, &regname, 1);
6683 }
6684 
6685 /*
6686  * Get or set v:exception.  If "oldval" == NULL, return the current value.
6687  * Otherwise, restore the value to "oldval" and return NULL.
6688  * Must always be called in pairs to save and restore v:exception!  Does not
6689  * take care of memory allocations.
6690  */
6691     char_u *
6692 v_exception(char_u *oldval)
6693 {
6694     if (oldval == NULL)
6695 	return vimvars[VV_EXCEPTION].vv_str;
6696 
6697     vimvars[VV_EXCEPTION].vv_str = oldval;
6698     return NULL;
6699 }
6700 
6701 /*
6702  * Get or set v:throwpoint.  If "oldval" == NULL, return the current value.
6703  * Otherwise, restore the value to "oldval" and return NULL.
6704  * Must always be called in pairs to save and restore v:throwpoint!  Does not
6705  * take care of memory allocations.
6706  */
6707     char_u *
6708 v_throwpoint(char_u *oldval)
6709 {
6710     if (oldval == NULL)
6711 	return vimvars[VV_THROWPOINT].vv_str;
6712 
6713     vimvars[VV_THROWPOINT].vv_str = oldval;
6714     return NULL;
6715 }
6716 
6717 #if defined(FEAT_AUTOCMD) || defined(PROTO)
6718 /*
6719  * Set v:cmdarg.
6720  * If "eap" != NULL, use "eap" to generate the value and return the old value.
6721  * If "oldarg" != NULL, restore the value to "oldarg" and return NULL.
6722  * Must always be called in pairs!
6723  */
6724     char_u *
6725 set_cmdarg(exarg_T *eap, char_u *oldarg)
6726 {
6727     char_u	*oldval;
6728     char_u	*newval;
6729     unsigned	len;
6730 
6731     oldval = vimvars[VV_CMDARG].vv_str;
6732     if (eap == NULL)
6733     {
6734 	vim_free(oldval);
6735 	vimvars[VV_CMDARG].vv_str = oldarg;
6736 	return NULL;
6737     }
6738 
6739     if (eap->force_bin == FORCE_BIN)
6740 	len = 6;
6741     else if (eap->force_bin == FORCE_NOBIN)
6742 	len = 8;
6743     else
6744 	len = 0;
6745 
6746     if (eap->read_edit)
6747 	len += 7;
6748 
6749     if (eap->force_ff != 0)
6750 	len += (unsigned)STRLEN(eap->cmd + eap->force_ff) + 6;
6751 # ifdef FEAT_MBYTE
6752     if (eap->force_enc != 0)
6753 	len += (unsigned)STRLEN(eap->cmd + eap->force_enc) + 7;
6754     if (eap->bad_char != 0)
6755 	len += 7 + 4;  /* " ++bad=" + "keep" or "drop" */
6756 # endif
6757 
6758     newval = alloc(len + 1);
6759     if (newval == NULL)
6760 	return NULL;
6761 
6762     if (eap->force_bin == FORCE_BIN)
6763 	sprintf((char *)newval, " ++bin");
6764     else if (eap->force_bin == FORCE_NOBIN)
6765 	sprintf((char *)newval, " ++nobin");
6766     else
6767 	*newval = NUL;
6768 
6769     if (eap->read_edit)
6770 	STRCAT(newval, " ++edit");
6771 
6772     if (eap->force_ff != 0)
6773 	sprintf((char *)newval + STRLEN(newval), " ++ff=%s",
6774 						eap->cmd + eap->force_ff);
6775 # ifdef FEAT_MBYTE
6776     if (eap->force_enc != 0)
6777 	sprintf((char *)newval + STRLEN(newval), " ++enc=%s",
6778 					       eap->cmd + eap->force_enc);
6779     if (eap->bad_char == BAD_KEEP)
6780 	STRCPY(newval + STRLEN(newval), " ++bad=keep");
6781     else if (eap->bad_char == BAD_DROP)
6782 	STRCPY(newval + STRLEN(newval), " ++bad=drop");
6783     else if (eap->bad_char != 0)
6784 	sprintf((char *)newval + STRLEN(newval), " ++bad=%c", eap->bad_char);
6785 # endif
6786     vimvars[VV_CMDARG].vv_str = newval;
6787     return oldval;
6788 }
6789 #endif
6790 
6791 /*
6792  * Get the value of internal variable "name".
6793  * Return OK or FAIL.
6794  */
6795     int
6796 get_var_tv(
6797     char_u	*name,
6798     int		len,		/* length of "name" */
6799     typval_T	*rettv,		/* NULL when only checking existence */
6800     dictitem_T	**dip,		/* non-NULL when typval's dict item is needed */
6801     int		verbose,	/* may give error message */
6802     int		no_autoload)	/* do not use script autoloading */
6803 {
6804     int		ret = OK;
6805     typval_T	*tv = NULL;
6806     dictitem_T	*v;
6807     int		cc;
6808 
6809     /* truncate the name, so that we can use strcmp() */
6810     cc = name[len];
6811     name[len] = NUL;
6812 
6813     /*
6814      * Check for user-defined variables.
6815      */
6816     v = find_var(name, NULL, no_autoload);
6817     if (v != NULL)
6818     {
6819 	tv = &v->di_tv;
6820 	if (dip != NULL)
6821 	    *dip = v;
6822     }
6823 
6824     if (tv == NULL)
6825     {
6826 	if (rettv != NULL && verbose)
6827 	    EMSG2(_(e_undefvar), name);
6828 	ret = FAIL;
6829     }
6830     else if (rettv != NULL)
6831 	copy_tv(tv, rettv);
6832 
6833     name[len] = cc;
6834 
6835     return ret;
6836 }
6837 
6838 /*
6839  * Check if variable "name[len]" is a local variable or an argument.
6840  * If so, "*eval_lavars_used" is set to TRUE.
6841  */
6842     static void
6843 check_vars(char_u *name, int len)
6844 {
6845     int		cc;
6846     char_u	*varname;
6847     hashtab_T	*ht;
6848 
6849     if (eval_lavars_used == NULL)
6850 	return;
6851 
6852     /* truncate the name, so that we can use strcmp() */
6853     cc = name[len];
6854     name[len] = NUL;
6855 
6856     ht = find_var_ht(name, &varname);
6857     if (ht == get_funccal_local_ht() || ht == get_funccal_args_ht())
6858     {
6859 	if (find_var(name, NULL, TRUE) != NULL)
6860 	    *eval_lavars_used = TRUE;
6861     }
6862 
6863     name[len] = cc;
6864 }
6865 
6866 /*
6867  * Handle expr[expr], expr[expr:expr] subscript and .name lookup.
6868  * Also handle function call with Funcref variable: func(expr)
6869  * Can all be combined: dict.func(expr)[idx]['func'](expr)
6870  */
6871     int
6872 handle_subscript(
6873     char_u	**arg,
6874     typval_T	*rettv,
6875     int		evaluate,	/* do more than finding the end */
6876     int		verbose)	/* give error messages */
6877 {
6878     int		ret = OK;
6879     dict_T	*selfdict = NULL;
6880     char_u	*s;
6881     int		len;
6882     typval_T	functv;
6883 
6884     while (ret == OK
6885 	    && (**arg == '['
6886 		|| (**arg == '.' && rettv->v_type == VAR_DICT)
6887 		|| (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
6888 					    || rettv->v_type == VAR_PARTIAL)))
6889 	    && !VIM_ISWHITE(*(*arg - 1)))
6890     {
6891 	if (**arg == '(')
6892 	{
6893 	    partial_T	*pt = NULL;
6894 
6895 	    /* need to copy the funcref so that we can clear rettv */
6896 	    if (evaluate)
6897 	    {
6898 		functv = *rettv;
6899 		rettv->v_type = VAR_UNKNOWN;
6900 
6901 		/* Invoke the function.  Recursive! */
6902 		if (functv.v_type == VAR_PARTIAL)
6903 		{
6904 		    pt = functv.vval.v_partial;
6905 		    s = partial_name(pt);
6906 		}
6907 		else
6908 		    s = functv.vval.v_string;
6909 	    }
6910 	    else
6911 		s = (char_u *)"";
6912 	    ret = get_func_tv(s, (int)STRLEN(s), rettv, arg,
6913 			curwin->w_cursor.lnum, curwin->w_cursor.lnum,
6914 			&len, evaluate, pt, selfdict);
6915 
6916 	    /* Clear the funcref afterwards, so that deleting it while
6917 	     * evaluating the arguments is possible (see test55). */
6918 	    if (evaluate)
6919 		clear_tv(&functv);
6920 
6921 	    /* Stop the expression evaluation when immediately aborting on
6922 	     * error, or when an interrupt occurred or an exception was thrown
6923 	     * but not caught. */
6924 	    if (aborting())
6925 	    {
6926 		if (ret == OK)
6927 		    clear_tv(rettv);
6928 		ret = FAIL;
6929 	    }
6930 	    dict_unref(selfdict);
6931 	    selfdict = NULL;
6932 	}
6933 	else /* **arg == '[' || **arg == '.' */
6934 	{
6935 	    dict_unref(selfdict);
6936 	    if (rettv->v_type == VAR_DICT)
6937 	    {
6938 		selfdict = rettv->vval.v_dict;
6939 		if (selfdict != NULL)
6940 		    ++selfdict->dv_refcount;
6941 	    }
6942 	    else
6943 		selfdict = NULL;
6944 	    if (eval_index(arg, rettv, evaluate, verbose) == FAIL)
6945 	    {
6946 		clear_tv(rettv);
6947 		ret = FAIL;
6948 	    }
6949 	}
6950     }
6951 
6952     /* Turn "dict.Func" into a partial for "Func" bound to "dict".
6953      * Don't do this when "Func" is already a partial that was bound
6954      * explicitly (pt_auto is FALSE). */
6955     if (selfdict != NULL
6956 	    && (rettv->v_type == VAR_FUNC
6957 		|| (rettv->v_type == VAR_PARTIAL
6958 		    && (rettv->vval.v_partial->pt_auto
6959 			|| rettv->vval.v_partial->pt_dict == NULL))))
6960 	selfdict = make_partial(selfdict, rettv);
6961 
6962     dict_unref(selfdict);
6963     return ret;
6964 }
6965 
6966 /*
6967  * Allocate memory for a variable type-value, and make it empty (0 or NULL
6968  * value).
6969  */
6970     typval_T *
6971 alloc_tv(void)
6972 {
6973     return (typval_T *)alloc_clear((unsigned)sizeof(typval_T));
6974 }
6975 
6976 /*
6977  * Allocate memory for a variable type-value, and assign a string to it.
6978  * The string "s" must have been allocated, it is consumed.
6979  * Return NULL for out of memory, the variable otherwise.
6980  */
6981     static typval_T *
6982 alloc_string_tv(char_u *s)
6983 {
6984     typval_T	*rettv;
6985 
6986     rettv = alloc_tv();
6987     if (rettv != NULL)
6988     {
6989 	rettv->v_type = VAR_STRING;
6990 	rettv->vval.v_string = s;
6991     }
6992     else
6993 	vim_free(s);
6994     return rettv;
6995 }
6996 
6997 /*
6998  * Free the memory for a variable type-value.
6999  */
7000     void
7001 free_tv(typval_T *varp)
7002 {
7003     if (varp != NULL)
7004     {
7005 	switch (varp->v_type)
7006 	{
7007 	    case VAR_FUNC:
7008 		func_unref(varp->vval.v_string);
7009 		/*FALLTHROUGH*/
7010 	    case VAR_STRING:
7011 		vim_free(varp->vval.v_string);
7012 		break;
7013 	    case VAR_PARTIAL:
7014 		partial_unref(varp->vval.v_partial);
7015 		break;
7016 	    case VAR_LIST:
7017 		list_unref(varp->vval.v_list);
7018 		break;
7019 	    case VAR_DICT:
7020 		dict_unref(varp->vval.v_dict);
7021 		break;
7022 	    case VAR_JOB:
7023 #ifdef FEAT_JOB_CHANNEL
7024 		job_unref(varp->vval.v_job);
7025 		break;
7026 #endif
7027 	    case VAR_CHANNEL:
7028 #ifdef FEAT_JOB_CHANNEL
7029 		channel_unref(varp->vval.v_channel);
7030 		break;
7031 #endif
7032 	    case VAR_NUMBER:
7033 	    case VAR_FLOAT:
7034 	    case VAR_UNKNOWN:
7035 	    case VAR_SPECIAL:
7036 		break;
7037 	}
7038 	vim_free(varp);
7039     }
7040 }
7041 
7042 /*
7043  * Free the memory for a variable value and set the value to NULL or 0.
7044  */
7045     void
7046 clear_tv(typval_T *varp)
7047 {
7048     if (varp != NULL)
7049     {
7050 	switch (varp->v_type)
7051 	{
7052 	    case VAR_FUNC:
7053 		func_unref(varp->vval.v_string);
7054 		/*FALLTHROUGH*/
7055 	    case VAR_STRING:
7056 		vim_free(varp->vval.v_string);
7057 		varp->vval.v_string = NULL;
7058 		break;
7059 	    case VAR_PARTIAL:
7060 		partial_unref(varp->vval.v_partial);
7061 		varp->vval.v_partial = NULL;
7062 		break;
7063 	    case VAR_LIST:
7064 		list_unref(varp->vval.v_list);
7065 		varp->vval.v_list = NULL;
7066 		break;
7067 	    case VAR_DICT:
7068 		dict_unref(varp->vval.v_dict);
7069 		varp->vval.v_dict = NULL;
7070 		break;
7071 	    case VAR_NUMBER:
7072 	    case VAR_SPECIAL:
7073 		varp->vval.v_number = 0;
7074 		break;
7075 	    case VAR_FLOAT:
7076 #ifdef FEAT_FLOAT
7077 		varp->vval.v_float = 0.0;
7078 		break;
7079 #endif
7080 	    case VAR_JOB:
7081 #ifdef FEAT_JOB_CHANNEL
7082 		job_unref(varp->vval.v_job);
7083 		varp->vval.v_job = NULL;
7084 #endif
7085 		break;
7086 	    case VAR_CHANNEL:
7087 #ifdef FEAT_JOB_CHANNEL
7088 		channel_unref(varp->vval.v_channel);
7089 		varp->vval.v_channel = NULL;
7090 #endif
7091 	    case VAR_UNKNOWN:
7092 		break;
7093 	}
7094 	varp->v_lock = 0;
7095     }
7096 }
7097 
7098 /*
7099  * Set the value of a variable to NULL without freeing items.
7100  */
7101     void
7102 init_tv(typval_T *varp)
7103 {
7104     if (varp != NULL)
7105 	vim_memset(varp, 0, sizeof(typval_T));
7106 }
7107 
7108 /*
7109  * Get the number value of a variable.
7110  * If it is a String variable, uses vim_str2nr().
7111  * For incompatible types, return 0.
7112  * get_tv_number_chk() is similar to get_tv_number(), but informs the
7113  * caller of incompatible types: it sets *denote to TRUE if "denote"
7114  * is not NULL or returns -1 otherwise.
7115  */
7116     varnumber_T
7117 get_tv_number(typval_T *varp)
7118 {
7119     int		error = FALSE;
7120 
7121     return get_tv_number_chk(varp, &error);	/* return 0L on error */
7122 }
7123 
7124     varnumber_T
7125 get_tv_number_chk(typval_T *varp, int *denote)
7126 {
7127     varnumber_T	n = 0L;
7128 
7129     switch (varp->v_type)
7130     {
7131 	case VAR_NUMBER:
7132 	    return varp->vval.v_number;
7133 	case VAR_FLOAT:
7134 #ifdef FEAT_FLOAT
7135 	    EMSG(_("E805: Using a Float as a Number"));
7136 	    break;
7137 #endif
7138 	case VAR_FUNC:
7139 	case VAR_PARTIAL:
7140 	    EMSG(_("E703: Using a Funcref as a Number"));
7141 	    break;
7142 	case VAR_STRING:
7143 	    if (varp->vval.v_string != NULL)
7144 		vim_str2nr(varp->vval.v_string, NULL, NULL,
7145 						    STR2NR_ALL, &n, NULL, 0);
7146 	    return n;
7147 	case VAR_LIST:
7148 	    EMSG(_("E745: Using a List as a Number"));
7149 	    break;
7150 	case VAR_DICT:
7151 	    EMSG(_("E728: Using a Dictionary as a Number"));
7152 	    break;
7153 	case VAR_SPECIAL:
7154 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
7155 	    break;
7156 	case VAR_JOB:
7157 #ifdef FEAT_JOB_CHANNEL
7158 	    EMSG(_("E910: Using a Job as a Number"));
7159 	    break;
7160 #endif
7161 	case VAR_CHANNEL:
7162 #ifdef FEAT_JOB_CHANNEL
7163 	    EMSG(_("E913: Using a Channel as a Number"));
7164 	    break;
7165 #endif
7166 	case VAR_UNKNOWN:
7167 	    internal_error("get_tv_number(UNKNOWN)");
7168 	    break;
7169     }
7170     if (denote == NULL)		/* useful for values that must be unsigned */
7171 	n = -1;
7172     else
7173 	*denote = TRUE;
7174     return n;
7175 }
7176 
7177 #ifdef FEAT_FLOAT
7178     float_T
7179 get_tv_float(typval_T *varp)
7180 {
7181     switch (varp->v_type)
7182     {
7183 	case VAR_NUMBER:
7184 	    return (float_T)(varp->vval.v_number);
7185 	case VAR_FLOAT:
7186 	    return varp->vval.v_float;
7187 	case VAR_FUNC:
7188 	case VAR_PARTIAL:
7189 	    EMSG(_("E891: Using a Funcref as a Float"));
7190 	    break;
7191 	case VAR_STRING:
7192 	    EMSG(_("E892: Using a String as a Float"));
7193 	    break;
7194 	case VAR_LIST:
7195 	    EMSG(_("E893: Using a List as a Float"));
7196 	    break;
7197 	case VAR_DICT:
7198 	    EMSG(_("E894: Using a Dictionary as a Float"));
7199 	    break;
7200 	case VAR_SPECIAL:
7201 	    EMSG(_("E907: Using a special value as a Float"));
7202 	    break;
7203 	case VAR_JOB:
7204 # ifdef FEAT_JOB_CHANNEL
7205 	    EMSG(_("E911: Using a Job as a Float"));
7206 	    break;
7207 # endif
7208 	case VAR_CHANNEL:
7209 # ifdef FEAT_JOB_CHANNEL
7210 	    EMSG(_("E914: Using a Channel as a Float"));
7211 	    break;
7212 # endif
7213 	case VAR_UNKNOWN:
7214 	    internal_error("get_tv_float(UNKNOWN)");
7215 	    break;
7216     }
7217     return 0;
7218 }
7219 #endif
7220 
7221 /*
7222  * Get the string value of a variable.
7223  * If it is a Number variable, the number is converted into a string.
7224  * get_tv_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7225  * get_tv_string_buf() uses a given buffer.
7226  * If the String variable has never been set, return an empty string.
7227  * Never returns NULL;
7228  * get_tv_string_chk() and get_tv_string_buf_chk() are similar, but return
7229  * NULL on error.
7230  */
7231     char_u *
7232 get_tv_string(typval_T *varp)
7233 {
7234     static char_u   mybuf[NUMBUFLEN];
7235 
7236     return get_tv_string_buf(varp, mybuf);
7237 }
7238 
7239     char_u *
7240 get_tv_string_buf(typval_T *varp, char_u *buf)
7241 {
7242     char_u	*res =  get_tv_string_buf_chk(varp, buf);
7243 
7244     return res != NULL ? res : (char_u *)"";
7245 }
7246 
7247 /*
7248  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7249  */
7250     char_u *
7251 get_tv_string_chk(typval_T *varp)
7252 {
7253     static char_u   mybuf[NUMBUFLEN];
7254 
7255     return get_tv_string_buf_chk(varp, mybuf);
7256 }
7257 
7258     char_u *
7259 get_tv_string_buf_chk(typval_T *varp, char_u *buf)
7260 {
7261     switch (varp->v_type)
7262     {
7263 	case VAR_NUMBER:
7264 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
7265 					    (varnumber_T)varp->vval.v_number);
7266 	    return buf;
7267 	case VAR_FUNC:
7268 	case VAR_PARTIAL:
7269 	    EMSG(_("E729: using Funcref as a String"));
7270 	    break;
7271 	case VAR_LIST:
7272 	    EMSG(_("E730: using List as a String"));
7273 	    break;
7274 	case VAR_DICT:
7275 	    EMSG(_("E731: using Dictionary as a String"));
7276 	    break;
7277 	case VAR_FLOAT:
7278 #ifdef FEAT_FLOAT
7279 	    EMSG(_(e_float_as_string));
7280 	    break;
7281 #endif
7282 	case VAR_STRING:
7283 	    if (varp->vval.v_string != NULL)
7284 		return varp->vval.v_string;
7285 	    return (char_u *)"";
7286 	case VAR_SPECIAL:
7287 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
7288 	    return buf;
7289 	case VAR_JOB:
7290 #ifdef FEAT_JOB_CHANNEL
7291 	    {
7292 		job_T *job = varp->vval.v_job;
7293 		char  *status;
7294 
7295 		if (job == NULL)
7296 		    return (char_u *)"no process";
7297 		status = job->jv_status == JOB_FAILED ? "fail"
7298 				: job->jv_status >= JOB_ENDED ? "dead"
7299 				: "run";
7300 # ifdef UNIX
7301 		vim_snprintf((char *)buf, NUMBUFLEN,
7302 			    "process %ld %s", (long)job->jv_pid, status);
7303 # elif defined(WIN32)
7304 		vim_snprintf((char *)buf, NUMBUFLEN,
7305 			    "process %ld %s",
7306 			    (long)job->jv_proc_info.dwProcessId,
7307 			    status);
7308 # else
7309 		/* fall-back */
7310 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
7311 # endif
7312 		return buf;
7313 	    }
7314 #endif
7315 	    break;
7316 	case VAR_CHANNEL:
7317 #ifdef FEAT_JOB_CHANNEL
7318 	    {
7319 		channel_T *channel = varp->vval.v_channel;
7320 		char      *status = channel_status(channel, -1);
7321 
7322 		if (channel == NULL)
7323 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
7324 		else
7325 		    vim_snprintf((char *)buf, NUMBUFLEN,
7326 				     "channel %d %s", channel->ch_id, status);
7327 		return buf;
7328 	    }
7329 #endif
7330 	    break;
7331 	case VAR_UNKNOWN:
7332 	    EMSG(_("E908: using an invalid value as a String"));
7333 	    break;
7334     }
7335     return NULL;
7336 }
7337 
7338 /*
7339  * Find variable "name" in the list of variables.
7340  * Return a pointer to it if found, NULL if not found.
7341  * Careful: "a:0" variables don't have a name.
7342  * When "htp" is not NULL we are writing to the variable, set "htp" to the
7343  * hashtab_T used.
7344  */
7345     dictitem_T *
7346 find_var(char_u *name, hashtab_T **htp, int no_autoload)
7347 {
7348     char_u	*varname;
7349     hashtab_T	*ht;
7350     dictitem_T	*ret = NULL;
7351 
7352     ht = find_var_ht(name, &varname);
7353     if (htp != NULL)
7354 	*htp = ht;
7355     if (ht == NULL)
7356 	return NULL;
7357     ret = find_var_in_ht(ht, *name, varname, no_autoload || htp != NULL);
7358     if (ret != NULL)
7359 	return ret;
7360 
7361     /* Search in parent scope for lambda */
7362     return find_var_in_scoped_ht(name, no_autoload || htp != NULL);
7363 }
7364 
7365 /*
7366  * Find variable "varname" in hashtab "ht" with name "htname".
7367  * Returns NULL if not found.
7368  */
7369     dictitem_T *
7370 find_var_in_ht(
7371     hashtab_T	*ht,
7372     int		htname,
7373     char_u	*varname,
7374     int		no_autoload)
7375 {
7376     hashitem_T	*hi;
7377 
7378     if (*varname == NUL)
7379     {
7380 	/* Must be something like "s:", otherwise "ht" would be NULL. */
7381 	switch (htname)
7382 	{
7383 	    case 's': return &SCRIPT_SV(current_SID)->sv_var;
7384 	    case 'g': return &globvars_var;
7385 	    case 'v': return &vimvars_var;
7386 	    case 'b': return &curbuf->b_bufvar;
7387 	    case 'w': return &curwin->w_winvar;
7388 #ifdef FEAT_WINDOWS
7389 	    case 't': return &curtab->tp_winvar;
7390 #endif
7391 	    case 'l': return get_funccal_local_var();
7392 	    case 'a': return get_funccal_args_var();
7393 	}
7394 	return NULL;
7395     }
7396 
7397     hi = hash_find(ht, varname);
7398     if (HASHITEM_EMPTY(hi))
7399     {
7400 	/* For global variables we may try auto-loading the script.  If it
7401 	 * worked find the variable again.  Don't auto-load a script if it was
7402 	 * loaded already, otherwise it would be loaded every time when
7403 	 * checking if a function name is a Funcref variable. */
7404 	if (ht == &globvarht && !no_autoload)
7405 	{
7406 	    /* Note: script_autoload() may make "hi" invalid. It must either
7407 	     * be obtained again or not used. */
7408 	    if (!script_autoload(varname, FALSE) || aborting())
7409 		return NULL;
7410 	    hi = hash_find(ht, varname);
7411 	}
7412 	if (HASHITEM_EMPTY(hi))
7413 	    return NULL;
7414     }
7415     return HI2DI(hi);
7416 }
7417 
7418 /*
7419  * Find the hashtab used for a variable name.
7420  * Return NULL if the name is not valid.
7421  * Set "varname" to the start of name without ':'.
7422  */
7423     hashtab_T *
7424 find_var_ht(char_u *name, char_u **varname)
7425 {
7426     hashitem_T	*hi;
7427     hashtab_T	*ht;
7428 
7429     if (name[0] == NUL)
7430 	return NULL;
7431     if (name[1] != ':')
7432     {
7433 	/* The name must not start with a colon or #. */
7434 	if (name[0] == ':' || name[0] == AUTOLOAD_CHAR)
7435 	    return NULL;
7436 	*varname = name;
7437 
7438 	/* "version" is "v:version" in all scopes */
7439 	hi = hash_find(&compat_hashtab, name);
7440 	if (!HASHITEM_EMPTY(hi))
7441 	    return &compat_hashtab;
7442 
7443 	ht = get_funccal_local_ht();
7444 	if (ht == NULL)
7445 	    return &globvarht;			/* global variable */
7446 	return ht;				/* local variable */
7447     }
7448     *varname = name + 2;
7449     if (*name == 'g')				/* global variable */
7450 	return &globvarht;
7451     /* There must be no ':' or '#' in the rest of the name, unless g: is used
7452      */
7453     if (vim_strchr(name + 2, ':') != NULL
7454 			       || vim_strchr(name + 2, AUTOLOAD_CHAR) != NULL)
7455 	return NULL;
7456     if (*name == 'b')				/* buffer variable */
7457 	return &curbuf->b_vars->dv_hashtab;
7458     if (*name == 'w')				/* window variable */
7459 	return &curwin->w_vars->dv_hashtab;
7460 #ifdef FEAT_WINDOWS
7461     if (*name == 't')				/* tab page variable */
7462 	return &curtab->tp_vars->dv_hashtab;
7463 #endif
7464     if (*name == 'v')				/* v: variable */
7465 	return &vimvarht;
7466     if (*name == 'a')				/* a: function argument */
7467 	return get_funccal_args_ht();
7468     if (*name == 'l')				/* l: local function variable */
7469 	return get_funccal_local_ht();
7470     if (*name == 's'				/* script variable */
7471 	    && current_SID > 0 && current_SID <= ga_scripts.ga_len)
7472 	return &SCRIPT_VARS(current_SID);
7473     return NULL;
7474 }
7475 
7476 /*
7477  * Get the string value of a (global/local) variable.
7478  * Note: see get_tv_string() for how long the pointer remains valid.
7479  * Returns NULL when it doesn't exist.
7480  */
7481     char_u *
7482 get_var_value(char_u *name)
7483 {
7484     dictitem_T	*v;
7485 
7486     v = find_var(name, NULL, FALSE);
7487     if (v == NULL)
7488 	return NULL;
7489     return get_tv_string(&v->di_tv);
7490 }
7491 
7492 /*
7493  * Allocate a new hashtab for a sourced script.  It will be used while
7494  * sourcing this script and when executing functions defined in the script.
7495  */
7496     void
7497 new_script_vars(scid_T id)
7498 {
7499     int		i;
7500     hashtab_T	*ht;
7501     scriptvar_T *sv;
7502 
7503     if (ga_grow(&ga_scripts, (int)(id - ga_scripts.ga_len)) == OK)
7504     {
7505 	/* Re-allocating ga_data means that an ht_array pointing to
7506 	 * ht_smallarray becomes invalid.  We can recognize this: ht_mask is
7507 	 * at its init value.  Also reset "v_dict", it's always the same. */
7508 	for (i = 1; i <= ga_scripts.ga_len; ++i)
7509 	{
7510 	    ht = &SCRIPT_VARS(i);
7511 	    if (ht->ht_mask == HT_INIT_SIZE - 1)
7512 		ht->ht_array = ht->ht_smallarray;
7513 	    sv = SCRIPT_SV(i);
7514 	    sv->sv_var.di_tv.vval.v_dict = &sv->sv_dict;
7515 	}
7516 
7517 	while (ga_scripts.ga_len < id)
7518 	{
7519 	    sv = SCRIPT_SV(ga_scripts.ga_len + 1) =
7520 		(scriptvar_T *)alloc_clear(sizeof(scriptvar_T));
7521 	    init_var_dict(&sv->sv_dict, &sv->sv_var, VAR_SCOPE);
7522 	    ++ga_scripts.ga_len;
7523 	}
7524     }
7525 }
7526 
7527 /*
7528  * Initialize dictionary "dict" as a scope and set variable "dict_var" to
7529  * point to it.
7530  */
7531     void
7532 init_var_dict(dict_T *dict, dictitem_T *dict_var, int scope)
7533 {
7534     hash_init(&dict->dv_hashtab);
7535     dict->dv_lock = 0;
7536     dict->dv_scope = scope;
7537     dict->dv_refcount = DO_NOT_FREE_CNT;
7538     dict->dv_copyID = 0;
7539     dict_var->di_tv.vval.v_dict = dict;
7540     dict_var->di_tv.v_type = VAR_DICT;
7541     dict_var->di_tv.v_lock = VAR_FIXED;
7542     dict_var->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
7543     dict_var->di_key[0] = NUL;
7544 }
7545 
7546 /*
7547  * Unreference a dictionary initialized by init_var_dict().
7548  */
7549     void
7550 unref_var_dict(dict_T *dict)
7551 {
7552     /* Now the dict needs to be freed if no one else is using it, go back to
7553      * normal reference counting. */
7554     dict->dv_refcount -= DO_NOT_FREE_CNT - 1;
7555     dict_unref(dict);
7556 }
7557 
7558 /*
7559  * Clean up a list of internal variables.
7560  * Frees all allocated variables and the value they contain.
7561  * Clears hashtab "ht", does not free it.
7562  */
7563     void
7564 vars_clear(hashtab_T *ht)
7565 {
7566     vars_clear_ext(ht, TRUE);
7567 }
7568 
7569 /*
7570  * Like vars_clear(), but only free the value if "free_val" is TRUE.
7571  */
7572     void
7573 vars_clear_ext(hashtab_T *ht, int free_val)
7574 {
7575     int		todo;
7576     hashitem_T	*hi;
7577     dictitem_T	*v;
7578 
7579     hash_lock(ht);
7580     todo = (int)ht->ht_used;
7581     for (hi = ht->ht_array; todo > 0; ++hi)
7582     {
7583 	if (!HASHITEM_EMPTY(hi))
7584 	{
7585 	    --todo;
7586 
7587 	    /* Free the variable.  Don't remove it from the hashtab,
7588 	     * ht_array might change then.  hash_clear() takes care of it
7589 	     * later. */
7590 	    v = HI2DI(hi);
7591 	    if (free_val)
7592 		clear_tv(&v->di_tv);
7593 	    if (v->di_flags & DI_FLAGS_ALLOC)
7594 		vim_free(v);
7595 	}
7596     }
7597     hash_clear(ht);
7598     ht->ht_used = 0;
7599 }
7600 
7601 /*
7602  * Delete a variable from hashtab "ht" at item "hi".
7603  * Clear the variable value and free the dictitem.
7604  */
7605     static void
7606 delete_var(hashtab_T *ht, hashitem_T *hi)
7607 {
7608     dictitem_T	*di = HI2DI(hi);
7609 
7610     hash_remove(ht, hi);
7611     clear_tv(&di->di_tv);
7612     vim_free(di);
7613 }
7614 
7615 /*
7616  * List the value of one internal variable.
7617  */
7618     static void
7619 list_one_var(dictitem_T *v, char_u *prefix, int *first)
7620 {
7621     char_u	*tofree;
7622     char_u	*s;
7623     char_u	numbuf[NUMBUFLEN];
7624 
7625     s = echo_string(&v->di_tv, &tofree, numbuf, get_copyID());
7626     list_one_var_a(prefix, v->di_key, v->di_tv.v_type,
7627 					 s == NULL ? (char_u *)"" : s, first);
7628     vim_free(tofree);
7629 }
7630 
7631     static void
7632 list_one_var_a(
7633     char_u	*prefix,
7634     char_u	*name,
7635     int		type,
7636     char_u	*string,
7637     int		*first)  /* when TRUE clear rest of screen and set to FALSE */
7638 {
7639     /* don't use msg() or msg_attr() to avoid overwriting "v:statusmsg" */
7640     msg_start();
7641     msg_puts(prefix);
7642     if (name != NULL)	/* "a:" vars don't have a name stored */
7643 	msg_puts(name);
7644     msg_putchar(' ');
7645     msg_advance(22);
7646     if (type == VAR_NUMBER)
7647 	msg_putchar('#');
7648     else if (type == VAR_FUNC || type == VAR_PARTIAL)
7649 	msg_putchar('*');
7650     else if (type == VAR_LIST)
7651     {
7652 	msg_putchar('[');
7653 	if (*string == '[')
7654 	    ++string;
7655     }
7656     else if (type == VAR_DICT)
7657     {
7658 	msg_putchar('{');
7659 	if (*string == '{')
7660 	    ++string;
7661     }
7662     else
7663 	msg_putchar(' ');
7664 
7665     msg_outtrans(string);
7666 
7667     if (type == VAR_FUNC || type == VAR_PARTIAL)
7668 	msg_puts((char_u *)"()");
7669     if (*first)
7670     {
7671 	msg_clr_eos();
7672 	*first = FALSE;
7673     }
7674 }
7675 
7676 /*
7677  * Set variable "name" to value in "tv".
7678  * If the variable already exists, the value is updated.
7679  * Otherwise the variable is created.
7680  */
7681     void
7682 set_var(
7683     char_u	*name,
7684     typval_T	*tv,
7685     int		copy)	    /* make copy of value in "tv" */
7686 {
7687     dictitem_T	*v;
7688     char_u	*varname;
7689     hashtab_T	*ht;
7690 
7691     ht = find_var_ht(name, &varname);
7692     if (ht == NULL || *varname == NUL)
7693     {
7694 	EMSG2(_(e_illvar), name);
7695 	return;
7696     }
7697     v = find_var_in_ht(ht, 0, varname, TRUE);
7698 
7699     /* Search in parent scope which is possible to reference from lambda */
7700     if (v == NULL)
7701 	v = find_var_in_scoped_ht(name, TRUE);
7702 
7703     if ((tv->v_type == VAR_FUNC || tv->v_type == VAR_PARTIAL)
7704 				      && var_check_func_name(name, v == NULL))
7705 	return;
7706 
7707     if (v != NULL)
7708     {
7709 	/* existing variable, need to clear the value */
7710 	if (var_check_ro(v->di_flags, name, FALSE)
7711 			       || tv_check_lock(v->di_tv.v_lock, name, FALSE))
7712 	    return;
7713 
7714 	/*
7715 	 * Handle setting internal v: variables separately where needed to
7716 	 * prevent changing the type.
7717 	 */
7718 	if (ht == &vimvarht)
7719 	{
7720 	    if (v->di_tv.v_type == VAR_STRING)
7721 	    {
7722 		vim_free(v->di_tv.vval.v_string);
7723 		if (copy || tv->v_type != VAR_STRING)
7724 		    v->di_tv.vval.v_string = vim_strsave(get_tv_string(tv));
7725 		else
7726 		{
7727 		    /* Take over the string to avoid an extra alloc/free. */
7728 		    v->di_tv.vval.v_string = tv->vval.v_string;
7729 		    tv->vval.v_string = NULL;
7730 		}
7731 		return;
7732 	    }
7733 	    else if (v->di_tv.v_type == VAR_NUMBER)
7734 	    {
7735 		v->di_tv.vval.v_number = get_tv_number(tv);
7736 		if (STRCMP(varname, "searchforward") == 0)
7737 		    set_search_direction(v->di_tv.vval.v_number ? '/' : '?');
7738 #ifdef FEAT_SEARCH_EXTRA
7739 		else if (STRCMP(varname, "hlsearch") == 0)
7740 		{
7741 		    no_hlsearch = !v->di_tv.vval.v_number;
7742 		    redraw_all_later(SOME_VALID);
7743 		}
7744 #endif
7745 		return;
7746 	    }
7747 	    else if (v->di_tv.v_type != tv->v_type)
7748 		internal_error("set_var()");
7749 	}
7750 
7751 	clear_tv(&v->di_tv);
7752     }
7753     else		    /* add a new variable */
7754     {
7755 	/* Can't add "v:" variable. */
7756 	if (ht == &vimvarht)
7757 	{
7758 	    EMSG2(_(e_illvar), name);
7759 	    return;
7760 	}
7761 
7762 	/* Make sure the variable name is valid. */
7763 	if (!valid_varname(varname))
7764 	    return;
7765 
7766 	v = (dictitem_T *)alloc((unsigned)(sizeof(dictitem_T)
7767 							  + STRLEN(varname)));
7768 	if (v == NULL)
7769 	    return;
7770 	STRCPY(v->di_key, varname);
7771 	if (hash_add(ht, DI2HIKEY(v)) == FAIL)
7772 	{
7773 	    vim_free(v);
7774 	    return;
7775 	}
7776 	v->di_flags = DI_FLAGS_ALLOC;
7777     }
7778 
7779     if (copy || tv->v_type == VAR_NUMBER || tv->v_type == VAR_FLOAT)
7780 	copy_tv(tv, &v->di_tv);
7781     else
7782     {
7783 	v->di_tv = *tv;
7784 	v->di_tv.v_lock = 0;
7785 	init_tv(tv);
7786     }
7787 }
7788 
7789 /*
7790  * Return TRUE if di_flags "flags" indicates variable "name" is read-only.
7791  * Also give an error message.
7792  */
7793     int
7794 var_check_ro(int flags, char_u *name, int use_gettext)
7795 {
7796     if (flags & DI_FLAGS_RO)
7797     {
7798 	EMSG2(_(e_readonlyvar), use_gettext ? (char_u *)_(name) : name);
7799 	return TRUE;
7800     }
7801     if ((flags & DI_FLAGS_RO_SBX) && sandbox)
7802     {
7803 	EMSG2(_(e_readonlysbx), use_gettext ? (char_u *)_(name) : name);
7804 	return TRUE;
7805     }
7806     return FALSE;
7807 }
7808 
7809 /*
7810  * Return TRUE if di_flags "flags" indicates variable "name" is fixed.
7811  * Also give an error message.
7812  */
7813     int
7814 var_check_fixed(int flags, char_u *name, int use_gettext)
7815 {
7816     if (flags & DI_FLAGS_FIX)
7817     {
7818 	EMSG2(_("E795: Cannot delete variable %s"),
7819 				      use_gettext ? (char_u *)_(name) : name);
7820 	return TRUE;
7821     }
7822     return FALSE;
7823 }
7824 
7825 /*
7826  * Check if a funcref is assigned to a valid variable name.
7827  * Return TRUE and give an error if not.
7828  */
7829     int
7830 var_check_func_name(
7831     char_u *name,    /* points to start of variable name */
7832     int    new_var)  /* TRUE when creating the variable */
7833 {
7834     /* Allow for w: b: s: and t:. */
7835     if (!(vim_strchr((char_u *)"wbst", name[0]) != NULL && name[1] == ':')
7836 	    && !ASCII_ISUPPER((name[0] != NUL && name[1] == ':')
7837 						     ? name[2] : name[0]))
7838     {
7839 	EMSG2(_("E704: Funcref variable name must start with a capital: %s"),
7840 									name);
7841 	return TRUE;
7842     }
7843     /* Don't allow hiding a function.  When "v" is not NULL we might be
7844      * assigning another function to the same var, the type is checked
7845      * below. */
7846     if (new_var && function_exists(name, FALSE))
7847     {
7848 	EMSG2(_("E705: Variable name conflicts with existing function: %s"),
7849 								    name);
7850 	return TRUE;
7851     }
7852     return FALSE;
7853 }
7854 
7855 /*
7856  * Check if a variable name is valid.
7857  * Return FALSE and give an error if not.
7858  */
7859     int
7860 valid_varname(char_u *varname)
7861 {
7862     char_u *p;
7863 
7864     for (p = varname; *p != NUL; ++p)
7865 	if (!eval_isnamec1(*p) && (p == varname || !VIM_ISDIGIT(*p))
7866 						   && *p != AUTOLOAD_CHAR)
7867 	{
7868 	    EMSG2(_(e_illvar), varname);
7869 	    return FALSE;
7870 	}
7871     return TRUE;
7872 }
7873 
7874 /*
7875  * Return TRUE if typeval "tv" is set to be locked (immutable).
7876  * Also give an error message, using "name" or _("name") when use_gettext is
7877  * TRUE.
7878  */
7879     int
7880 tv_check_lock(int lock, char_u *name, int use_gettext)
7881 {
7882     if (lock & VAR_LOCKED)
7883     {
7884 	EMSG2(_("E741: Value is locked: %s"),
7885 				name == NULL ? (char_u *)_("Unknown")
7886 					     : use_gettext ? (char_u *)_(name)
7887 					     : name);
7888 	return TRUE;
7889     }
7890     if (lock & VAR_FIXED)
7891     {
7892 	EMSG2(_("E742: Cannot change value of %s"),
7893 				name == NULL ? (char_u *)_("Unknown")
7894 					     : use_gettext ? (char_u *)_(name)
7895 					     : name);
7896 	return TRUE;
7897     }
7898     return FALSE;
7899 }
7900 
7901 /*
7902  * Copy the values from typval_T "from" to typval_T "to".
7903  * When needed allocates string or increases reference count.
7904  * Does not make a copy of a list or dict but copies the reference!
7905  * It is OK for "from" and "to" to point to the same item.  This is used to
7906  * make a copy later.
7907  */
7908     void
7909 copy_tv(typval_T *from, typval_T *to)
7910 {
7911     to->v_type = from->v_type;
7912     to->v_lock = 0;
7913     switch (from->v_type)
7914     {
7915 	case VAR_NUMBER:
7916 	case VAR_SPECIAL:
7917 	    to->vval.v_number = from->vval.v_number;
7918 	    break;
7919 	case VAR_FLOAT:
7920 #ifdef FEAT_FLOAT
7921 	    to->vval.v_float = from->vval.v_float;
7922 	    break;
7923 #endif
7924 	case VAR_JOB:
7925 #ifdef FEAT_JOB_CHANNEL
7926 	    to->vval.v_job = from->vval.v_job;
7927 	    if (to->vval.v_job != NULL)
7928 		++to->vval.v_job->jv_refcount;
7929 	    break;
7930 #endif
7931 	case VAR_CHANNEL:
7932 #ifdef FEAT_JOB_CHANNEL
7933 	    to->vval.v_channel = from->vval.v_channel;
7934 	    if (to->vval.v_channel != NULL)
7935 		++to->vval.v_channel->ch_refcount;
7936 	    break;
7937 #endif
7938 	case VAR_STRING:
7939 	case VAR_FUNC:
7940 	    if (from->vval.v_string == NULL)
7941 		to->vval.v_string = NULL;
7942 	    else
7943 	    {
7944 		to->vval.v_string = vim_strsave(from->vval.v_string);
7945 		if (from->v_type == VAR_FUNC)
7946 		    func_ref(to->vval.v_string);
7947 	    }
7948 	    break;
7949 	case VAR_PARTIAL:
7950 	    if (from->vval.v_partial == NULL)
7951 		to->vval.v_partial = NULL;
7952 	    else
7953 	    {
7954 		to->vval.v_partial = from->vval.v_partial;
7955 		++to->vval.v_partial->pt_refcount;
7956 	    }
7957 	    break;
7958 	case VAR_LIST:
7959 	    if (from->vval.v_list == NULL)
7960 		to->vval.v_list = NULL;
7961 	    else
7962 	    {
7963 		to->vval.v_list = from->vval.v_list;
7964 		++to->vval.v_list->lv_refcount;
7965 	    }
7966 	    break;
7967 	case VAR_DICT:
7968 	    if (from->vval.v_dict == NULL)
7969 		to->vval.v_dict = NULL;
7970 	    else
7971 	    {
7972 		to->vval.v_dict = from->vval.v_dict;
7973 		++to->vval.v_dict->dv_refcount;
7974 	    }
7975 	    break;
7976 	case VAR_UNKNOWN:
7977 	    internal_error("copy_tv(UNKNOWN)");
7978 	    break;
7979     }
7980 }
7981 
7982 /*
7983  * Make a copy of an item.
7984  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
7985  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
7986  * reference to an already copied list/dict can be used.
7987  * Returns FAIL or OK.
7988  */
7989     int
7990 item_copy(
7991     typval_T	*from,
7992     typval_T	*to,
7993     int		deep,
7994     int		copyID)
7995 {
7996     static int	recurse = 0;
7997     int		ret = OK;
7998 
7999     if (recurse >= DICT_MAXNEST)
8000     {
8001 	EMSG(_("E698: variable nested too deep for making a copy"));
8002 	return FAIL;
8003     }
8004     ++recurse;
8005 
8006     switch (from->v_type)
8007     {
8008 	case VAR_NUMBER:
8009 	case VAR_FLOAT:
8010 	case VAR_STRING:
8011 	case VAR_FUNC:
8012 	case VAR_PARTIAL:
8013 	case VAR_SPECIAL:
8014 	case VAR_JOB:
8015 	case VAR_CHANNEL:
8016 	    copy_tv(from, to);
8017 	    break;
8018 	case VAR_LIST:
8019 	    to->v_type = VAR_LIST;
8020 	    to->v_lock = 0;
8021 	    if (from->vval.v_list == NULL)
8022 		to->vval.v_list = NULL;
8023 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
8024 	    {
8025 		/* use the copy made earlier */
8026 		to->vval.v_list = from->vval.v_list->lv_copylist;
8027 		++to->vval.v_list->lv_refcount;
8028 	    }
8029 	    else
8030 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
8031 	    if (to->vval.v_list == NULL)
8032 		ret = FAIL;
8033 	    break;
8034 	case VAR_DICT:
8035 	    to->v_type = VAR_DICT;
8036 	    to->v_lock = 0;
8037 	    if (from->vval.v_dict == NULL)
8038 		to->vval.v_dict = NULL;
8039 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
8040 	    {
8041 		/* use the copy made earlier */
8042 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
8043 		++to->vval.v_dict->dv_refcount;
8044 	    }
8045 	    else
8046 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
8047 	    if (to->vval.v_dict == NULL)
8048 		ret = FAIL;
8049 	    break;
8050 	case VAR_UNKNOWN:
8051 	    internal_error("item_copy(UNKNOWN)");
8052 	    ret = FAIL;
8053     }
8054     --recurse;
8055     return ret;
8056 }
8057 
8058 /*
8059  * This function is used by f_input() and f_inputdialog() functions. The third
8060  * argument to f_input() specifies the type of completion to use at the
8061  * prompt. The third argument to f_inputdialog() specifies the value to return
8062  * when the user cancels the prompt.
8063  */
8064     void
8065 get_user_input(
8066     typval_T	*argvars,
8067     typval_T	*rettv,
8068     int		inputdialog,
8069     int		secret)
8070 {
8071     char_u	*prompt = get_tv_string_chk(&argvars[0]);
8072     char_u	*p = NULL;
8073     int		c;
8074     char_u	buf[NUMBUFLEN];
8075     int		cmd_silent_save = cmd_silent;
8076     char_u	*defstr = (char_u *)"";
8077     int		xp_type = EXPAND_NOTHING;
8078     char_u	*xp_arg = NULL;
8079 
8080     rettv->v_type = VAR_STRING;
8081     rettv->vval.v_string = NULL;
8082 
8083 #ifdef NO_CONSOLE_INPUT
8084     /* While starting up, there is no place to enter text. When running tests
8085      * with --not-a-term we assume feedkeys() will be used. */
8086     if (no_console_input() && !is_not_a_term())
8087 	return;
8088 #endif
8089 
8090     cmd_silent = FALSE;		/* Want to see the prompt. */
8091     if (prompt != NULL)
8092     {
8093 	/* Only the part of the message after the last NL is considered as
8094 	 * prompt for the command line */
8095 	p = vim_strrchr(prompt, '\n');
8096 	if (p == NULL)
8097 	    p = prompt;
8098 	else
8099 	{
8100 	    ++p;
8101 	    c = *p;
8102 	    *p = NUL;
8103 	    msg_start();
8104 	    msg_clr_eos();
8105 	    msg_puts_attr(prompt, echo_attr);
8106 	    msg_didout = FALSE;
8107 	    msg_starthere();
8108 	    *p = c;
8109 	}
8110 	cmdline_row = msg_row;
8111 
8112 	if (argvars[1].v_type != VAR_UNKNOWN)
8113 	{
8114 	    defstr = get_tv_string_buf_chk(&argvars[1], buf);
8115 	    if (defstr != NULL)
8116 		stuffReadbuffSpec(defstr);
8117 
8118 	    if (!inputdialog && argvars[2].v_type != VAR_UNKNOWN)
8119 	    {
8120 		char_u	*xp_name;
8121 		int	xp_namelen;
8122 		long	argt;
8123 
8124 		/* input() with a third argument: completion */
8125 		rettv->vval.v_string = NULL;
8126 
8127 		xp_name = get_tv_string_buf_chk(&argvars[2], buf);
8128 		if (xp_name == NULL)
8129 		    return;
8130 
8131 		xp_namelen = (int)STRLEN(xp_name);
8132 
8133 		if (parse_compl_arg(xp_name, xp_namelen, &xp_type, &argt,
8134 							     &xp_arg) == FAIL)
8135 		    return;
8136 	    }
8137 	}
8138 
8139 	if (defstr != NULL)
8140 	{
8141 	    int save_ex_normal_busy = ex_normal_busy;
8142 	    ex_normal_busy = 0;
8143 	    rettv->vval.v_string =
8144 		getcmdline_prompt(secret ? NUL : '@', p, echo_attr,
8145 							      xp_type, xp_arg);
8146 	    ex_normal_busy = save_ex_normal_busy;
8147 	}
8148 	if (inputdialog && rettv->vval.v_string == NULL
8149 		&& argvars[1].v_type != VAR_UNKNOWN
8150 		&& argvars[2].v_type != VAR_UNKNOWN)
8151 	    rettv->vval.v_string = vim_strsave(get_tv_string_buf(
8152 							   &argvars[2], buf));
8153 
8154 	vim_free(xp_arg);
8155 
8156 	/* since the user typed this, no need to wait for return */
8157 	need_wait_return = FALSE;
8158 	msg_didout = FALSE;
8159     }
8160     cmd_silent = cmd_silent_save;
8161 }
8162 
8163 /*
8164  * ":echo expr1 ..."	print each argument separated with a space, add a
8165  *			newline at the end.
8166  * ":echon expr1 ..."	print each argument plain.
8167  */
8168     void
8169 ex_echo(exarg_T *eap)
8170 {
8171     char_u	*arg = eap->arg;
8172     typval_T	rettv;
8173     char_u	*tofree;
8174     char_u	*p;
8175     int		needclr = TRUE;
8176     int		atstart = TRUE;
8177     char_u	numbuf[NUMBUFLEN];
8178 
8179     if (eap->skip)
8180 	++emsg_skip;
8181     while (*arg != NUL && *arg != '|' && *arg != '\n' && !got_int)
8182     {
8183 	/* If eval1() causes an error message the text from the command may
8184 	 * still need to be cleared. E.g., "echo 22,44". */
8185 	need_clr_eos = needclr;
8186 
8187 	p = arg;
8188 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8189 	{
8190 	    /*
8191 	     * Report the invalid expression unless the expression evaluation
8192 	     * has been cancelled due to an aborting error, an interrupt, or an
8193 	     * exception.
8194 	     */
8195 	    if (!aborting())
8196 		EMSG2(_(e_invexpr2), p);
8197 	    need_clr_eos = FALSE;
8198 	    break;
8199 	}
8200 	need_clr_eos = FALSE;
8201 
8202 	if (!eap->skip)
8203 	{
8204 	    if (atstart)
8205 	    {
8206 		atstart = FALSE;
8207 		/* Call msg_start() after eval1(), evaluating the expression
8208 		 * may cause a message to appear. */
8209 		if (eap->cmdidx == CMD_echo)
8210 		{
8211 		    /* Mark the saved text as finishing the line, so that what
8212 		     * follows is displayed on a new line when scrolling back
8213 		     * at the more prompt. */
8214 		    msg_sb_eol();
8215 		    msg_start();
8216 		}
8217 	    }
8218 	    else if (eap->cmdidx == CMD_echo)
8219 		msg_puts_attr((char_u *)" ", echo_attr);
8220 	    p = echo_string(&rettv, &tofree, numbuf, get_copyID());
8221 	    if (p != NULL)
8222 		for ( ; *p != NUL && !got_int; ++p)
8223 		{
8224 		    if (*p == '\n' || *p == '\r' || *p == TAB)
8225 		    {
8226 			if (*p != TAB && needclr)
8227 			{
8228 			    /* remove any text still there from the command */
8229 			    msg_clr_eos();
8230 			    needclr = FALSE;
8231 			}
8232 			msg_putchar_attr(*p, echo_attr);
8233 		    }
8234 		    else
8235 		    {
8236 #ifdef FEAT_MBYTE
8237 			if (has_mbyte)
8238 			{
8239 			    int i = (*mb_ptr2len)(p);
8240 
8241 			    (void)msg_outtrans_len_attr(p, i, echo_attr);
8242 			    p += i - 1;
8243 			}
8244 			else
8245 #endif
8246 			    (void)msg_outtrans_len_attr(p, 1, echo_attr);
8247 		    }
8248 		}
8249 	    vim_free(tofree);
8250 	}
8251 	clear_tv(&rettv);
8252 	arg = skipwhite(arg);
8253     }
8254     eap->nextcmd = check_nextcmd(arg);
8255 
8256     if (eap->skip)
8257 	--emsg_skip;
8258     else
8259     {
8260 	/* remove text that may still be there from the command */
8261 	if (needclr)
8262 	    msg_clr_eos();
8263 	if (eap->cmdidx == CMD_echo)
8264 	    msg_end();
8265     }
8266 }
8267 
8268 /*
8269  * ":echohl {name}".
8270  */
8271     void
8272 ex_echohl(exarg_T *eap)
8273 {
8274     int		id;
8275 
8276     id = syn_name2id(eap->arg);
8277     if (id == 0)
8278 	echo_attr = 0;
8279     else
8280 	echo_attr = syn_id2attr(id);
8281 }
8282 
8283 /*
8284  * ":execute expr1 ..."	execute the result of an expression.
8285  * ":echomsg expr1 ..."	Print a message
8286  * ":echoerr expr1 ..."	Print an error
8287  * Each gets spaces around each argument and a newline at the end for
8288  * echo commands
8289  */
8290     void
8291 ex_execute(exarg_T *eap)
8292 {
8293     char_u	*arg = eap->arg;
8294     typval_T	rettv;
8295     int		ret = OK;
8296     char_u	*p;
8297     garray_T	ga;
8298     int		len;
8299     int		save_did_emsg;
8300 
8301     ga_init2(&ga, 1, 80);
8302 
8303     if (eap->skip)
8304 	++emsg_skip;
8305     while (*arg != NUL && *arg != '|' && *arg != '\n')
8306     {
8307 	p = arg;
8308 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8309 	{
8310 	    /*
8311 	     * Report the invalid expression unless the expression evaluation
8312 	     * has been cancelled due to an aborting error, an interrupt, or an
8313 	     * exception.
8314 	     */
8315 	    if (!aborting())
8316 		EMSG2(_(e_invexpr2), p);
8317 	    ret = FAIL;
8318 	    break;
8319 	}
8320 
8321 	if (!eap->skip)
8322 	{
8323 	    p = get_tv_string(&rettv);
8324 	    len = (int)STRLEN(p);
8325 	    if (ga_grow(&ga, len + 2) == FAIL)
8326 	    {
8327 		clear_tv(&rettv);
8328 		ret = FAIL;
8329 		break;
8330 	    }
8331 	    if (ga.ga_len)
8332 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
8333 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
8334 	    ga.ga_len += len;
8335 	}
8336 
8337 	clear_tv(&rettv);
8338 	arg = skipwhite(arg);
8339     }
8340 
8341     if (ret != FAIL && ga.ga_data != NULL)
8342     {
8343 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
8344 	{
8345 	    /* Mark the already saved text as finishing the line, so that what
8346 	     * follows is displayed on a new line when scrolling back at the
8347 	     * more prompt. */
8348 	    msg_sb_eol();
8349 	}
8350 
8351 	if (eap->cmdidx == CMD_echomsg)
8352 	{
8353 	    MSG_ATTR(ga.ga_data, echo_attr);
8354 	    out_flush();
8355 	}
8356 	else if (eap->cmdidx == CMD_echoerr)
8357 	{
8358 	    /* We don't want to abort following commands, restore did_emsg. */
8359 	    save_did_emsg = did_emsg;
8360 	    EMSG((char_u *)ga.ga_data);
8361 	    if (!force_abort)
8362 		did_emsg = save_did_emsg;
8363 	}
8364 	else if (eap->cmdidx == CMD_execute)
8365 	    do_cmdline((char_u *)ga.ga_data,
8366 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
8367     }
8368 
8369     ga_clear(&ga);
8370 
8371     if (eap->skip)
8372 	--emsg_skip;
8373 
8374     eap->nextcmd = check_nextcmd(arg);
8375 }
8376 
8377 /*
8378  * Find window specified by "vp" in tabpage "tp".
8379  */
8380     win_T *
8381 find_win_by_nr(
8382     typval_T	*vp,
8383     tabpage_T	*tp UNUSED)	/* NULL for current tab page */
8384 {
8385 #ifdef FEAT_WINDOWS
8386     win_T	*wp;
8387 #endif
8388     int		nr;
8389 
8390     nr = (int)get_tv_number_chk(vp, NULL);
8391 
8392 #ifdef FEAT_WINDOWS
8393     if (nr < 0)
8394 	return NULL;
8395     if (nr == 0)
8396 	return curwin;
8397 
8398     FOR_ALL_WINDOWS_IN_TAB(tp, wp)
8399     {
8400 	if (nr >= LOWEST_WIN_ID)
8401 	{
8402 	    if (wp->w_id == nr)
8403 		return wp;
8404 	}
8405 	else if (--nr <= 0)
8406 	    break;
8407     }
8408     if (nr >= LOWEST_WIN_ID)
8409 	return NULL;
8410     return wp;
8411 #else
8412     if (nr == 0 || nr == 1 || nr == curwin->w_id)
8413 	return curwin;
8414     return NULL;
8415 #endif
8416 }
8417 
8418 /*
8419  * Find window specified by "wvp" in tabpage "tvp".
8420  */
8421     win_T *
8422 find_tabwin(
8423     typval_T	*wvp,	/* VAR_UNKNOWN for current window */
8424     typval_T	*tvp)	/* VAR_UNKNOWN for current tab page */
8425 {
8426     win_T	*wp = NULL;
8427     tabpage_T	*tp = NULL;
8428     long	n;
8429 
8430     if (wvp->v_type != VAR_UNKNOWN)
8431     {
8432 	if (tvp->v_type != VAR_UNKNOWN)
8433 	{
8434 	    n = (long)get_tv_number(tvp);
8435 	    if (n >= 0)
8436 		tp = find_tabpage(n);
8437 	}
8438 	else
8439 	    tp = curtab;
8440 
8441 	if (tp != NULL)
8442 	    wp = find_win_by_nr(wvp, tp);
8443     }
8444     else
8445 	wp = curwin;
8446 
8447     return wp;
8448 }
8449 
8450 /*
8451  * getwinvar() and gettabwinvar()
8452  */
8453     void
8454 getwinvar(
8455     typval_T	*argvars,
8456     typval_T	*rettv,
8457     int		off)	    /* 1 for gettabwinvar() */
8458 {
8459     win_T	*win;
8460     char_u	*varname;
8461     dictitem_T	*v;
8462     tabpage_T	*tp = NULL;
8463     int		done = FALSE;
8464 #ifdef FEAT_WINDOWS
8465     win_T	*oldcurwin;
8466     tabpage_T	*oldtabpage;
8467     int		need_switch_win;
8468 #endif
8469 
8470 #ifdef FEAT_WINDOWS
8471     if (off == 1)
8472 	tp = find_tabpage((int)get_tv_number_chk(&argvars[0], NULL));
8473     else
8474 	tp = curtab;
8475 #endif
8476     win = find_win_by_nr(&argvars[off], tp);
8477     varname = get_tv_string_chk(&argvars[off + 1]);
8478     ++emsg_off;
8479 
8480     rettv->v_type = VAR_STRING;
8481     rettv->vval.v_string = NULL;
8482 
8483     if (win != NULL && varname != NULL)
8484     {
8485 #ifdef FEAT_WINDOWS
8486 	/* Set curwin to be our win, temporarily.  Also set the tabpage,
8487 	 * otherwise the window is not valid. Only do this when needed,
8488 	 * autocommands get blocked. */
8489 	need_switch_win = !(tp == curtab && win == curwin);
8490 	if (!need_switch_win
8491 		  || switch_win(&oldcurwin, &oldtabpage, win, tp, TRUE) == OK)
8492 #endif
8493 	{
8494 	    if (*varname == '&')
8495 	    {
8496 		if (varname[1] == NUL)
8497 		{
8498 		    /* get all window-local options in a dict */
8499 		    dict_T	*opts = get_winbuf_options(FALSE);
8500 
8501 		    if (opts != NULL)
8502 		    {
8503 			rettv_dict_set(rettv, opts);
8504 			done = TRUE;
8505 		    }
8506 		}
8507 		else if (get_option_tv(&varname, rettv, 1) == OK)
8508 		    /* window-local-option */
8509 		    done = TRUE;
8510 	    }
8511 	    else
8512 	    {
8513 		/* Look up the variable. */
8514 		/* Let getwinvar({nr}, "") return the "w:" dictionary. */
8515 		v = find_var_in_ht(&win->w_vars->dv_hashtab, 'w',
8516 							      varname, FALSE);
8517 		if (v != NULL)
8518 		{
8519 		    copy_tv(&v->di_tv, rettv);
8520 		    done = TRUE;
8521 		}
8522 	    }
8523 	}
8524 
8525 #ifdef FEAT_WINDOWS
8526 	if (need_switch_win)
8527 	    /* restore previous notion of curwin */
8528 	    restore_win(oldcurwin, oldtabpage, TRUE);
8529 #endif
8530     }
8531 
8532     if (!done && argvars[off + 2].v_type != VAR_UNKNOWN)
8533 	/* use the default return value */
8534 	copy_tv(&argvars[off + 2], rettv);
8535 
8536     --emsg_off;
8537 }
8538 
8539 /*
8540  * "setwinvar()" and "settabwinvar()" functions
8541  */
8542     void
8543 setwinvar(typval_T *argvars, typval_T *rettv UNUSED, int off)
8544 {
8545     win_T	*win;
8546 #ifdef FEAT_WINDOWS
8547     win_T	*save_curwin;
8548     tabpage_T	*save_curtab;
8549     int		need_switch_win;
8550 #endif
8551     char_u	*varname, *winvarname;
8552     typval_T	*varp;
8553     char_u	nbuf[NUMBUFLEN];
8554     tabpage_T	*tp = NULL;
8555 
8556     if (check_restricted() || check_secure())
8557 	return;
8558 
8559 #ifdef FEAT_WINDOWS
8560     if (off == 1)
8561 	tp = find_tabpage((int)get_tv_number_chk(&argvars[0], NULL));
8562     else
8563 	tp = curtab;
8564 #endif
8565     win = find_win_by_nr(&argvars[off], tp);
8566     varname = get_tv_string_chk(&argvars[off + 1]);
8567     varp = &argvars[off + 2];
8568 
8569     if (win != NULL && varname != NULL && varp != NULL)
8570     {
8571 #ifdef FEAT_WINDOWS
8572 	need_switch_win = !(tp == curtab && win == curwin);
8573 	if (!need_switch_win
8574 	       || switch_win(&save_curwin, &save_curtab, win, tp, TRUE) == OK)
8575 #endif
8576 	{
8577 	    if (*varname == '&')
8578 	    {
8579 		long	numval;
8580 		char_u	*strval;
8581 		int		error = FALSE;
8582 
8583 		++varname;
8584 		numval = (long)get_tv_number_chk(varp, &error);
8585 		strval = get_tv_string_buf_chk(varp, nbuf);
8586 		if (!error && strval != NULL)
8587 		    set_option_value(varname, numval, strval, OPT_LOCAL);
8588 	    }
8589 	    else
8590 	    {
8591 		winvarname = alloc((unsigned)STRLEN(varname) + 3);
8592 		if (winvarname != NULL)
8593 		{
8594 		    STRCPY(winvarname, "w:");
8595 		    STRCPY(winvarname + 2, varname);
8596 		    set_var(winvarname, varp, TRUE);
8597 		    vim_free(winvarname);
8598 		}
8599 	    }
8600 	}
8601 #ifdef FEAT_WINDOWS
8602 	if (need_switch_win)
8603 	    restore_win(save_curwin, save_curtab, TRUE);
8604 #endif
8605     }
8606 }
8607 
8608 /*
8609  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
8610  * "arg" points to the "&" or '+' when called, to "option" when returning.
8611  * Returns NULL when no option name found.  Otherwise pointer to the char
8612  * after the option name.
8613  */
8614     static char_u *
8615 find_option_end(char_u **arg, int *opt_flags)
8616 {
8617     char_u	*p = *arg;
8618 
8619     ++p;
8620     if (*p == 'g' && p[1] == ':')
8621     {
8622 	*opt_flags = OPT_GLOBAL;
8623 	p += 2;
8624     }
8625     else if (*p == 'l' && p[1] == ':')
8626     {
8627 	*opt_flags = OPT_LOCAL;
8628 	p += 2;
8629     }
8630     else
8631 	*opt_flags = 0;
8632 
8633     if (!ASCII_ISALPHA(*p))
8634 	return NULL;
8635     *arg = p;
8636 
8637     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
8638 	p += 4;	    /* termcap option */
8639     else
8640 	while (ASCII_ISALPHA(*p))
8641 	    ++p;
8642     return p;
8643 }
8644 
8645 /*
8646  * Return the autoload script name for a function or variable name.
8647  * Returns NULL when out of memory.
8648  */
8649     char_u *
8650 autoload_name(char_u *name)
8651 {
8652     char_u	*p;
8653     char_u	*scriptname;
8654 
8655     /* Get the script file name: replace '#' with '/', append ".vim". */
8656     scriptname = alloc((unsigned)(STRLEN(name) + 14));
8657     if (scriptname == NULL)
8658 	return FALSE;
8659     STRCPY(scriptname, "autoload/");
8660     STRCAT(scriptname, name);
8661     *vim_strrchr(scriptname, AUTOLOAD_CHAR) = NUL;
8662     STRCAT(scriptname, ".vim");
8663     while ((p = vim_strchr(scriptname, AUTOLOAD_CHAR)) != NULL)
8664 	*p = '/';
8665     return scriptname;
8666 }
8667 
8668 /*
8669  * If "name" has a package name try autoloading the script for it.
8670  * Return TRUE if a package was loaded.
8671  */
8672     int
8673 script_autoload(
8674     char_u	*name,
8675     int		reload)	    /* load script again when already loaded */
8676 {
8677     char_u	*p;
8678     char_u	*scriptname, *tofree;
8679     int		ret = FALSE;
8680     int		i;
8681 
8682     /* If there is no '#' after name[0] there is no package name. */
8683     p = vim_strchr(name, AUTOLOAD_CHAR);
8684     if (p == NULL || p == name)
8685 	return FALSE;
8686 
8687     tofree = scriptname = autoload_name(name);
8688 
8689     /* Find the name in the list of previously loaded package names.  Skip
8690      * "autoload/", it's always the same. */
8691     for (i = 0; i < ga_loaded.ga_len; ++i)
8692 	if (STRCMP(((char_u **)ga_loaded.ga_data)[i] + 9, scriptname + 9) == 0)
8693 	    break;
8694     if (!reload && i < ga_loaded.ga_len)
8695 	ret = FALSE;	    /* was loaded already */
8696     else
8697     {
8698 	/* Remember the name if it wasn't loaded already. */
8699 	if (i == ga_loaded.ga_len && ga_grow(&ga_loaded, 1) == OK)
8700 	{
8701 	    ((char_u **)ga_loaded.ga_data)[ga_loaded.ga_len++] = scriptname;
8702 	    tofree = NULL;
8703 	}
8704 
8705 	/* Try loading the package from $VIMRUNTIME/autoload/<name>.vim */
8706 	if (source_runtime(scriptname, 0) == OK)
8707 	    ret = TRUE;
8708     }
8709 
8710     vim_free(tofree);
8711     return ret;
8712 }
8713 
8714 #if defined(FEAT_VIMINFO) || defined(FEAT_SESSION)
8715 typedef enum
8716 {
8717     VAR_FLAVOUR_DEFAULT,	/* doesn't start with uppercase */
8718     VAR_FLAVOUR_SESSION,	/* starts with uppercase, some lower */
8719     VAR_FLAVOUR_VIMINFO		/* all uppercase */
8720 } var_flavour_T;
8721 
8722 static var_flavour_T var_flavour(char_u *varname);
8723 
8724     static var_flavour_T
8725 var_flavour(char_u *varname)
8726 {
8727     char_u *p = varname;
8728 
8729     if (ASCII_ISUPPER(*p))
8730     {
8731 	while (*(++p))
8732 	    if (ASCII_ISLOWER(*p))
8733 		return VAR_FLAVOUR_SESSION;
8734 	return VAR_FLAVOUR_VIMINFO;
8735     }
8736     else
8737 	return VAR_FLAVOUR_DEFAULT;
8738 }
8739 #endif
8740 
8741 #if defined(FEAT_VIMINFO) || defined(PROTO)
8742 /*
8743  * Restore global vars that start with a capital from the viminfo file
8744  */
8745     int
8746 read_viminfo_varlist(vir_T *virp, int writing)
8747 {
8748     char_u	*tab;
8749     int		type = VAR_NUMBER;
8750     typval_T	tv;
8751     void	*save_funccal;
8752 
8753     if (!writing && (find_viminfo_parameter('!') != NULL))
8754     {
8755 	tab = vim_strchr(virp->vir_line + 1, '\t');
8756 	if (tab != NULL)
8757 	{
8758 	    *tab++ = '\0';	/* isolate the variable name */
8759 	    switch (*tab)
8760 	    {
8761 		case 'S': type = VAR_STRING; break;
8762 #ifdef FEAT_FLOAT
8763 		case 'F': type = VAR_FLOAT; break;
8764 #endif
8765 		case 'D': type = VAR_DICT; break;
8766 		case 'L': type = VAR_LIST; break;
8767 		case 'X': type = VAR_SPECIAL; break;
8768 	    }
8769 
8770 	    tab = vim_strchr(tab, '\t');
8771 	    if (tab != NULL)
8772 	    {
8773 		tv.v_type = type;
8774 		if (type == VAR_STRING || type == VAR_DICT || type == VAR_LIST)
8775 		    tv.vval.v_string = viminfo_readstring(virp,
8776 				       (int)(tab - virp->vir_line + 1), TRUE);
8777 #ifdef FEAT_FLOAT
8778 		else if (type == VAR_FLOAT)
8779 		    (void)string2float(tab + 1, &tv.vval.v_float);
8780 #endif
8781 		else
8782 		    tv.vval.v_number = atol((char *)tab + 1);
8783 		if (type == VAR_DICT || type == VAR_LIST)
8784 		{
8785 		    typval_T *etv = eval_expr(tv.vval.v_string, NULL);
8786 
8787 		    if (etv == NULL)
8788 			/* Failed to parse back the dict or list, use it as a
8789 			 * string. */
8790 			tv.v_type = VAR_STRING;
8791 		    else
8792 		    {
8793 			vim_free(tv.vval.v_string);
8794 			tv = *etv;
8795 			vim_free(etv);
8796 		    }
8797 		}
8798 
8799 		/* when in a function use global variables */
8800 		save_funccal = clear_current_funccal();
8801 		set_var(virp->vir_line + 1, &tv, FALSE);
8802 		restore_current_funccal(save_funccal);
8803 
8804 		if (tv.v_type == VAR_STRING)
8805 		    vim_free(tv.vval.v_string);
8806 		else if (tv.v_type == VAR_DICT || tv.v_type == VAR_LIST)
8807 		    clear_tv(&tv);
8808 	    }
8809 	}
8810     }
8811 
8812     return viminfo_readline(virp);
8813 }
8814 
8815 /*
8816  * Write global vars that start with a capital to the viminfo file
8817  */
8818     void
8819 write_viminfo_varlist(FILE *fp)
8820 {
8821     hashitem_T	*hi;
8822     dictitem_T	*this_var;
8823     int		todo;
8824     char	*s = "";
8825     char_u	*p;
8826     char_u	*tofree;
8827     char_u	numbuf[NUMBUFLEN];
8828 
8829     if (find_viminfo_parameter('!') == NULL)
8830 	return;
8831 
8832     fputs(_("\n# global variables:\n"), fp);
8833 
8834     todo = (int)globvarht.ht_used;
8835     for (hi = globvarht.ht_array; todo > 0; ++hi)
8836     {
8837 	if (!HASHITEM_EMPTY(hi))
8838 	{
8839 	    --todo;
8840 	    this_var = HI2DI(hi);
8841 	    if (var_flavour(this_var->di_key) == VAR_FLAVOUR_VIMINFO)
8842 	    {
8843 		switch (this_var->di_tv.v_type)
8844 		{
8845 		    case VAR_STRING: s = "STR"; break;
8846 		    case VAR_NUMBER: s = "NUM"; break;
8847 		    case VAR_FLOAT:  s = "FLO"; break;
8848 		    case VAR_DICT:   s = "DIC"; break;
8849 		    case VAR_LIST:   s = "LIS"; break;
8850 		    case VAR_SPECIAL: s = "XPL"; break;
8851 
8852 		    case VAR_UNKNOWN:
8853 		    case VAR_FUNC:
8854 		    case VAR_PARTIAL:
8855 		    case VAR_JOB:
8856 		    case VAR_CHANNEL:
8857 				     continue;
8858 		}
8859 		fprintf(fp, "!%s\t%s\t", this_var->di_key, s);
8860 		p = echo_string(&this_var->di_tv, &tofree, numbuf, 0);
8861 		if (p != NULL)
8862 		    viminfo_writestring(fp, p);
8863 		vim_free(tofree);
8864 	    }
8865 	}
8866     }
8867 }
8868 #endif
8869 
8870 #if defined(FEAT_SESSION) || defined(PROTO)
8871     int
8872 store_session_globals(FILE *fd)
8873 {
8874     hashitem_T	*hi;
8875     dictitem_T	*this_var;
8876     int		todo;
8877     char_u	*p, *t;
8878 
8879     todo = (int)globvarht.ht_used;
8880     for (hi = globvarht.ht_array; todo > 0; ++hi)
8881     {
8882 	if (!HASHITEM_EMPTY(hi))
8883 	{
8884 	    --todo;
8885 	    this_var = HI2DI(hi);
8886 	    if ((this_var->di_tv.v_type == VAR_NUMBER
8887 			|| this_var->di_tv.v_type == VAR_STRING)
8888 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
8889 	    {
8890 		/* Escape special characters with a backslash.  Turn a LF and
8891 		 * CR into \n and \r. */
8892 		p = vim_strsave_escaped(get_tv_string(&this_var->di_tv),
8893 							(char_u *)"\\\"\n\r");
8894 		if (p == NULL)	    /* out of memory */
8895 		    break;
8896 		for (t = p; *t != NUL; ++t)
8897 		    if (*t == '\n')
8898 			*t = 'n';
8899 		    else if (*t == '\r')
8900 			*t = 'r';
8901 		if ((fprintf(fd, "let %s = %c%s%c",
8902 				this_var->di_key,
8903 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
8904 									: ' ',
8905 				p,
8906 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
8907 								   : ' ') < 0)
8908 			|| put_eol(fd) == FAIL)
8909 		{
8910 		    vim_free(p);
8911 		    return FAIL;
8912 		}
8913 		vim_free(p);
8914 	    }
8915 #ifdef FEAT_FLOAT
8916 	    else if (this_var->di_tv.v_type == VAR_FLOAT
8917 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
8918 	    {
8919 		float_T f = this_var->di_tv.vval.v_float;
8920 		int sign = ' ';
8921 
8922 		if (f < 0)
8923 		{
8924 		    f = -f;
8925 		    sign = '-';
8926 		}
8927 		if ((fprintf(fd, "let %s = %c%f",
8928 					       this_var->di_key, sign, f) < 0)
8929 			|| put_eol(fd) == FAIL)
8930 		    return FAIL;
8931 	    }
8932 #endif
8933 	}
8934     }
8935     return OK;
8936 }
8937 #endif
8938 
8939 /*
8940  * Display script name where an item was last set.
8941  * Should only be invoked when 'verbose' is non-zero.
8942  */
8943     void
8944 last_set_msg(scid_T scriptID)
8945 {
8946     char_u *p;
8947 
8948     if (scriptID != 0)
8949     {
8950 	p = home_replace_save(NULL, get_scriptname(scriptID));
8951 	if (p != NULL)
8952 	{
8953 	    verbose_enter();
8954 	    MSG_PUTS(_("\n\tLast set from "));
8955 	    MSG_PUTS(p);
8956 	    vim_free(p);
8957 	    verbose_leave();
8958 	}
8959     }
8960 }
8961 
8962 /* reset v:option_new, v:option_old and v:option_type */
8963     void
8964 reset_v_option_vars(void)
8965 {
8966     set_vim_var_string(VV_OPTION_NEW,  NULL, -1);
8967     set_vim_var_string(VV_OPTION_OLD,  NULL, -1);
8968     set_vim_var_string(VV_OPTION_TYPE, NULL, -1);
8969 }
8970 
8971 /*
8972  * Prepare "gap" for an assert error and add the sourcing position.
8973  */
8974     void
8975 prepare_assert_error(garray_T *gap)
8976 {
8977     char buf[NUMBUFLEN];
8978 
8979     ga_init2(gap, 1, 100);
8980     if (sourcing_name != NULL)
8981     {
8982 	ga_concat(gap, sourcing_name);
8983 	if (sourcing_lnum > 0)
8984 	    ga_concat(gap, (char_u *)" ");
8985     }
8986     if (sourcing_lnum > 0)
8987     {
8988 	sprintf(buf, "line %ld", (long)sourcing_lnum);
8989 	ga_concat(gap, (char_u *)buf);
8990     }
8991     if (sourcing_name != NULL || sourcing_lnum > 0)
8992 	ga_concat(gap, (char_u *)": ");
8993 }
8994 
8995 /*
8996  * Add an assert error to v:errors.
8997  */
8998     void
8999 assert_error(garray_T *gap)
9000 {
9001     struct vimvar   *vp = &vimvars[VV_ERRORS];
9002 
9003     if (vp->vv_type != VAR_LIST || vimvars[VV_ERRORS].vv_list == NULL)
9004 	/* Make sure v:errors is a list. */
9005 	set_vim_var_list(VV_ERRORS, list_alloc());
9006     list_append_string(vimvars[VV_ERRORS].vv_list, gap->ga_data, gap->ga_len);
9007 }
9008 
9009     void
9010 assert_equal_common(typval_T *argvars, assert_type_T atype)
9011 {
9012     garray_T	ga;
9013 
9014     if (tv_equal(&argvars[0], &argvars[1], FALSE, FALSE)
9015 						   != (atype == ASSERT_EQUAL))
9016     {
9017 	prepare_assert_error(&ga);
9018 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
9019 								       atype);
9020 	assert_error(&ga);
9021 	ga_clear(&ga);
9022     }
9023 }
9024 
9025     void
9026 assert_match_common(typval_T *argvars, assert_type_T atype)
9027 {
9028     garray_T	ga;
9029     char_u	buf1[NUMBUFLEN];
9030     char_u	buf2[NUMBUFLEN];
9031     char_u	*pat = get_tv_string_buf_chk(&argvars[0], buf1);
9032     char_u	*text = get_tv_string_buf_chk(&argvars[1], buf2);
9033 
9034     if (pat == NULL || text == NULL)
9035 	EMSG(_(e_invarg));
9036     else if (pattern_match(pat, text, FALSE) != (atype == ASSERT_MATCH))
9037     {
9038 	prepare_assert_error(&ga);
9039 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
9040 									atype);
9041 	assert_error(&ga);
9042 	ga_clear(&ga);
9043     }
9044 }
9045 
9046     void
9047 assert_inrange(typval_T *argvars)
9048 {
9049     garray_T	ga;
9050     int		error = FALSE;
9051     varnumber_T	lower = get_tv_number_chk(&argvars[0], &error);
9052     varnumber_T	upper = get_tv_number_chk(&argvars[1], &error);
9053     varnumber_T	actual = get_tv_number_chk(&argvars[2], &error);
9054     char_u	*tofree;
9055     char	msg[200];
9056     char_u	numbuf[NUMBUFLEN];
9057 
9058     if (error)
9059 	return;
9060     if (actual < lower || actual > upper)
9061     {
9062 	prepare_assert_error(&ga);
9063 	if (argvars[3].v_type != VAR_UNKNOWN)
9064 	{
9065 	    ga_concat(&ga, tv2string(&argvars[3], &tofree, numbuf, 0));
9066 	    vim_free(tofree);
9067 	}
9068 	else
9069 	{
9070 	    vim_snprintf(msg, 200, "Expected range %ld - %ld, but got %ld",
9071 				       (long)lower, (long)upper, (long)actual);
9072 	    ga_concat(&ga, (char_u *)msg);
9073 	}
9074 	assert_error(&ga);
9075 	ga_clear(&ga);
9076     }
9077 }
9078 
9079 /*
9080  * Common for assert_true() and assert_false().
9081  */
9082     void
9083 assert_bool(typval_T *argvars, int isTrue)
9084 {
9085     int		error = FALSE;
9086     garray_T	ga;
9087 
9088     if (argvars[0].v_type == VAR_SPECIAL
9089 	    && argvars[0].vval.v_number == (isTrue ? VVAL_TRUE : VVAL_FALSE))
9090 	return;
9091     if (argvars[0].v_type != VAR_NUMBER
9092 	    || (get_tv_number_chk(&argvars[0], &error) == 0) == isTrue
9093 	    || error)
9094     {
9095 	prepare_assert_error(&ga);
9096 	fill_assert_error(&ga, &argvars[1],
9097 		(char_u *)(isTrue ? "True" : "False"),
9098 		NULL, &argvars[0], ASSERT_OTHER);
9099 	assert_error(&ga);
9100 	ga_clear(&ga);
9101     }
9102 }
9103 
9104     void
9105 assert_report(typval_T *argvars)
9106 {
9107     garray_T	ga;
9108 
9109     prepare_assert_error(&ga);
9110     ga_concat(&ga, get_tv_string(&argvars[0]));
9111     assert_error(&ga);
9112     ga_clear(&ga);
9113 }
9114 
9115     void
9116 assert_exception(typval_T *argvars)
9117 {
9118     garray_T	ga;
9119     char_u	*error = get_tv_string_chk(&argvars[0]);
9120 
9121     if (vimvars[VV_EXCEPTION].vv_str == NULL)
9122     {
9123 	prepare_assert_error(&ga);
9124 	ga_concat(&ga, (char_u *)"v:exception is not set");
9125 	assert_error(&ga);
9126 	ga_clear(&ga);
9127     }
9128     else if (error != NULL
9129 	&& strstr((char *)vimvars[VV_EXCEPTION].vv_str, (char *)error) == NULL)
9130     {
9131 	prepare_assert_error(&ga);
9132 	fill_assert_error(&ga, &argvars[1], NULL, &argvars[0],
9133 				  &vimvars[VV_EXCEPTION].vv_tv, ASSERT_OTHER);
9134 	assert_error(&ga);
9135 	ga_clear(&ga);
9136     }
9137 }
9138 
9139     void
9140 assert_fails(typval_T *argvars)
9141 {
9142     char_u	*cmd = get_tv_string_chk(&argvars[0]);
9143     garray_T	ga;
9144 
9145     called_emsg = FALSE;
9146     suppress_errthrow = TRUE;
9147     emsg_silent = TRUE;
9148     do_cmdline_cmd(cmd);
9149     if (!called_emsg)
9150     {
9151 	prepare_assert_error(&ga);
9152 	ga_concat(&ga, (char_u *)"command did not fail: ");
9153 	ga_concat(&ga, cmd);
9154 	assert_error(&ga);
9155 	ga_clear(&ga);
9156     }
9157     else if (argvars[1].v_type != VAR_UNKNOWN)
9158     {
9159 	char_u	buf[NUMBUFLEN];
9160 	char	*error = (char *)get_tv_string_buf_chk(&argvars[1], buf);
9161 
9162 	if (error == NULL
9163 		  || strstr((char *)vimvars[VV_ERRMSG].vv_str, error) == NULL)
9164 	{
9165 	    prepare_assert_error(&ga);
9166 	    fill_assert_error(&ga, &argvars[2], NULL, &argvars[1],
9167 				     &vimvars[VV_ERRMSG].vv_tv, ASSERT_OTHER);
9168 	    assert_error(&ga);
9169 	    ga_clear(&ga);
9170 	}
9171     }
9172 
9173     called_emsg = FALSE;
9174     suppress_errthrow = FALSE;
9175     emsg_silent = FALSE;
9176     emsg_on_display = FALSE;
9177     set_vim_var_string(VV_ERRMSG, NULL, 0);
9178 }
9179 
9180 /*
9181  * Append "str" to "gap", escaping unprintable characters.
9182  * Changes NL to \n, CR to \r, etc.
9183  */
9184     static void
9185 ga_concat_esc(garray_T *gap, char_u *str)
9186 {
9187     char_u  *p;
9188     char_u  buf[NUMBUFLEN];
9189 
9190     if (str == NULL)
9191     {
9192 	ga_concat(gap, (char_u *)"NULL");
9193 	return;
9194     }
9195 
9196     for (p = str; *p != NUL; ++p)
9197 	switch (*p)
9198 	{
9199 	    case BS: ga_concat(gap, (char_u *)"\\b"); break;
9200 	    case ESC: ga_concat(gap, (char_u *)"\\e"); break;
9201 	    case FF: ga_concat(gap, (char_u *)"\\f"); break;
9202 	    case NL: ga_concat(gap, (char_u *)"\\n"); break;
9203 	    case TAB: ga_concat(gap, (char_u *)"\\t"); break;
9204 	    case CAR: ga_concat(gap, (char_u *)"\\r"); break;
9205 	    case '\\': ga_concat(gap, (char_u *)"\\\\"); break;
9206 	    default:
9207 		if (*p < ' ')
9208 		{
9209 		    vim_snprintf((char *)buf, NUMBUFLEN, "\\x%02x", *p);
9210 		    ga_concat(gap, buf);
9211 		}
9212 		else
9213 		    ga_append(gap, *p);
9214 		break;
9215 	}
9216 }
9217 
9218 /*
9219  * Fill "gap" with information about an assert error.
9220  */
9221     void
9222 fill_assert_error(
9223     garray_T	*gap,
9224     typval_T	*opt_msg_tv,
9225     char_u      *exp_str,
9226     typval_T	*exp_tv,
9227     typval_T	*got_tv,
9228     assert_type_T atype)
9229 {
9230     char_u	numbuf[NUMBUFLEN];
9231     char_u	*tofree;
9232 
9233     if (opt_msg_tv->v_type != VAR_UNKNOWN)
9234     {
9235 	ga_concat(gap, echo_string(opt_msg_tv, &tofree, numbuf, 0));
9236 	vim_free(tofree);
9237 	ga_concat(gap, (char_u *)": ");
9238     }
9239 
9240     if (atype == ASSERT_MATCH || atype == ASSERT_NOTMATCH)
9241 	ga_concat(gap, (char_u *)"Pattern ");
9242     else if (atype == ASSERT_NOTEQUAL)
9243 	ga_concat(gap, (char_u *)"Expected not equal to ");
9244     else
9245 	ga_concat(gap, (char_u *)"Expected ");
9246     if (exp_str == NULL)
9247     {
9248 	ga_concat_esc(gap, tv2string(exp_tv, &tofree, numbuf, 0));
9249 	vim_free(tofree);
9250     }
9251     else
9252 	ga_concat_esc(gap, exp_str);
9253     if (atype != ASSERT_NOTEQUAL)
9254     {
9255 	if (atype == ASSERT_MATCH)
9256 	    ga_concat(gap, (char_u *)" does not match ");
9257 	else if (atype == ASSERT_NOTMATCH)
9258 	    ga_concat(gap, (char_u *)" does match ");
9259 	else
9260 	    ga_concat(gap, (char_u *)" but got ");
9261 	ga_concat_esc(gap, tv2string(got_tv, &tofree, numbuf, 0));
9262 	vim_free(tofree);
9263     }
9264 }
9265 
9266 
9267 #endif /* FEAT_EVAL */
9268 
9269 
9270 #if defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) || defined(PROTO)
9271 
9272 #ifdef WIN3264
9273 /*
9274  * Functions for ":8" filename modifier: get 8.3 version of a filename.
9275  */
9276 static int get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen);
9277 static int shortpath_for_invalid_fname(char_u **fname, char_u **bufp, int *fnamelen);
9278 static int shortpath_for_partial(char_u **fnamep, char_u **bufp, int *fnamelen);
9279 
9280 /*
9281  * Get the short path (8.3) for the filename in "fnamep".
9282  * Only works for a valid file name.
9283  * When the path gets longer "fnamep" is changed and the allocated buffer
9284  * is put in "bufp".
9285  * *fnamelen is the length of "fnamep" and set to 0 for a nonexistent path.
9286  * Returns OK on success, FAIL on failure.
9287  */
9288     static int
9289 get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen)
9290 {
9291     int		l, len;
9292     char_u	*newbuf;
9293 
9294     len = *fnamelen;
9295     l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, len);
9296     if (l > len - 1)
9297     {
9298 	/* If that doesn't work (not enough space), then save the string
9299 	 * and try again with a new buffer big enough. */
9300 	newbuf = vim_strnsave(*fnamep, l);
9301 	if (newbuf == NULL)
9302 	    return FAIL;
9303 
9304 	vim_free(*bufp);
9305 	*fnamep = *bufp = newbuf;
9306 
9307 	/* Really should always succeed, as the buffer is big enough. */
9308 	l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, l+1);
9309     }
9310 
9311     *fnamelen = l;
9312     return OK;
9313 }
9314 
9315 /*
9316  * Get the short path (8.3) for the filename in "fname". The converted
9317  * path is returned in "bufp".
9318  *
9319  * Some of the directories specified in "fname" may not exist. This function
9320  * will shorten the existing directories at the beginning of the path and then
9321  * append the remaining non-existing path.
9322  *
9323  * fname - Pointer to the filename to shorten.  On return, contains the
9324  *	   pointer to the shortened pathname
9325  * bufp -  Pointer to an allocated buffer for the filename.
9326  * fnamelen - Length of the filename pointed to by fname
9327  *
9328  * Returns OK on success (or nothing done) and FAIL on failure (out of memory).
9329  */
9330     static int
9331 shortpath_for_invalid_fname(
9332     char_u	**fname,
9333     char_u	**bufp,
9334     int		*fnamelen)
9335 {
9336     char_u	*short_fname, *save_fname, *pbuf_unused;
9337     char_u	*endp, *save_endp;
9338     char_u	ch;
9339     int		old_len, len;
9340     int		new_len, sfx_len;
9341     int		retval = OK;
9342 
9343     /* Make a copy */
9344     old_len = *fnamelen;
9345     save_fname = vim_strnsave(*fname, old_len);
9346     pbuf_unused = NULL;
9347     short_fname = NULL;
9348 
9349     endp = save_fname + old_len - 1; /* Find the end of the copy */
9350     save_endp = endp;
9351 
9352     /*
9353      * Try shortening the supplied path till it succeeds by removing one
9354      * directory at a time from the tail of the path.
9355      */
9356     len = 0;
9357     for (;;)
9358     {
9359 	/* go back one path-separator */
9360 	while (endp > save_fname && !after_pathsep(save_fname, endp + 1))
9361 	    --endp;
9362 	if (endp <= save_fname)
9363 	    break;		/* processed the complete path */
9364 
9365 	/*
9366 	 * Replace the path separator with a NUL and try to shorten the
9367 	 * resulting path.
9368 	 */
9369 	ch = *endp;
9370 	*endp = 0;
9371 	short_fname = save_fname;
9372 	len = (int)STRLEN(short_fname) + 1;
9373 	if (get_short_pathname(&short_fname, &pbuf_unused, &len) == FAIL)
9374 	{
9375 	    retval = FAIL;
9376 	    goto theend;
9377 	}
9378 	*endp = ch;	/* preserve the string */
9379 
9380 	if (len > 0)
9381 	    break;	/* successfully shortened the path */
9382 
9383 	/* failed to shorten the path. Skip the path separator */
9384 	--endp;
9385     }
9386 
9387     if (len > 0)
9388     {
9389 	/*
9390 	 * Succeeded in shortening the path. Now concatenate the shortened
9391 	 * path with the remaining path at the tail.
9392 	 */
9393 
9394 	/* Compute the length of the new path. */
9395 	sfx_len = (int)(save_endp - endp) + 1;
9396 	new_len = len + sfx_len;
9397 
9398 	*fnamelen = new_len;
9399 	vim_free(*bufp);
9400 	if (new_len > old_len)
9401 	{
9402 	    /* There is not enough space in the currently allocated string,
9403 	     * copy it to a buffer big enough. */
9404 	    *fname = *bufp = vim_strnsave(short_fname, new_len);
9405 	    if (*fname == NULL)
9406 	    {
9407 		retval = FAIL;
9408 		goto theend;
9409 	    }
9410 	}
9411 	else
9412 	{
9413 	    /* Transfer short_fname to the main buffer (it's big enough),
9414 	     * unless get_short_pathname() did its work in-place. */
9415 	    *fname = *bufp = save_fname;
9416 	    if (short_fname != save_fname)
9417 		vim_strncpy(save_fname, short_fname, len);
9418 	    save_fname = NULL;
9419 	}
9420 
9421 	/* concat the not-shortened part of the path */
9422 	vim_strncpy(*fname + len, endp, sfx_len);
9423 	(*fname)[new_len] = NUL;
9424     }
9425 
9426 theend:
9427     vim_free(pbuf_unused);
9428     vim_free(save_fname);
9429 
9430     return retval;
9431 }
9432 
9433 /*
9434  * Get a pathname for a partial path.
9435  * Returns OK for success, FAIL for failure.
9436  */
9437     static int
9438 shortpath_for_partial(
9439     char_u	**fnamep,
9440     char_u	**bufp,
9441     int		*fnamelen)
9442 {
9443     int		sepcount, len, tflen;
9444     char_u	*p;
9445     char_u	*pbuf, *tfname;
9446     int		hasTilde;
9447 
9448     /* Count up the path separators from the RHS.. so we know which part
9449      * of the path to return. */
9450     sepcount = 0;
9451     for (p = *fnamep; p < *fnamep + *fnamelen; MB_PTR_ADV(p))
9452 	if (vim_ispathsep(*p))
9453 	    ++sepcount;
9454 
9455     /* Need full path first (use expand_env() to remove a "~/") */
9456     hasTilde = (**fnamep == '~');
9457     if (hasTilde)
9458 	pbuf = tfname = expand_env_save(*fnamep);
9459     else
9460 	pbuf = tfname = FullName_save(*fnamep, FALSE);
9461 
9462     len = tflen = (int)STRLEN(tfname);
9463 
9464     if (get_short_pathname(&tfname, &pbuf, &len) == FAIL)
9465 	return FAIL;
9466 
9467     if (len == 0)
9468     {
9469 	/* Don't have a valid filename, so shorten the rest of the
9470 	 * path if we can. This CAN give us invalid 8.3 filenames, but
9471 	 * there's not a lot of point in guessing what it might be.
9472 	 */
9473 	len = tflen;
9474 	if (shortpath_for_invalid_fname(&tfname, &pbuf, &len) == FAIL)
9475 	    return FAIL;
9476     }
9477 
9478     /* Count the paths backward to find the beginning of the desired string. */
9479     for (p = tfname + len - 1; p >= tfname; --p)
9480     {
9481 #ifdef FEAT_MBYTE
9482 	if (has_mbyte)
9483 	    p -= mb_head_off(tfname, p);
9484 #endif
9485 	if (vim_ispathsep(*p))
9486 	{
9487 	    if (sepcount == 0 || (hasTilde && sepcount == 1))
9488 		break;
9489 	    else
9490 		sepcount --;
9491 	}
9492     }
9493     if (hasTilde)
9494     {
9495 	--p;
9496 	if (p >= tfname)
9497 	    *p = '~';
9498 	else
9499 	    return FAIL;
9500     }
9501     else
9502 	++p;
9503 
9504     /* Copy in the string - p indexes into tfname - allocated at pbuf */
9505     vim_free(*bufp);
9506     *fnamelen = (int)STRLEN(p);
9507     *bufp = pbuf;
9508     *fnamep = p;
9509 
9510     return OK;
9511 }
9512 #endif /* WIN3264 */
9513 
9514 /*
9515  * Adjust a filename, according to a string of modifiers.
9516  * *fnamep must be NUL terminated when called.  When returning, the length is
9517  * determined by *fnamelen.
9518  * Returns VALID_ flags or -1 for failure.
9519  * When there is an error, *fnamep is set to NULL.
9520  */
9521     int
9522 modify_fname(
9523     char_u	*src,		/* string with modifiers */
9524     int		*usedlen,	/* characters after src that are used */
9525     char_u	**fnamep,	/* file name so far */
9526     char_u	**bufp,		/* buffer for allocated file name or NULL */
9527     int		*fnamelen)	/* length of fnamep */
9528 {
9529     int		valid = 0;
9530     char_u	*tail;
9531     char_u	*s, *p, *pbuf;
9532     char_u	dirname[MAXPATHL];
9533     int		c;
9534     int		has_fullname = 0;
9535 #ifdef WIN3264
9536     char_u	*fname_start = *fnamep;
9537     int		has_shortname = 0;
9538 #endif
9539 
9540 repeat:
9541     /* ":p" - full path/file_name */
9542     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'p')
9543     {
9544 	has_fullname = 1;
9545 
9546 	valid |= VALID_PATH;
9547 	*usedlen += 2;
9548 
9549 	/* Expand "~/path" for all systems and "~user/path" for Unix and VMS */
9550 	if ((*fnamep)[0] == '~'
9551 #if !defined(UNIX) && !(defined(VMS) && defined(USER_HOME))
9552 		&& ((*fnamep)[1] == '/'
9553 # ifdef BACKSLASH_IN_FILENAME
9554 		    || (*fnamep)[1] == '\\'
9555 # endif
9556 		    || (*fnamep)[1] == NUL)
9557 
9558 #endif
9559 	   )
9560 	{
9561 	    *fnamep = expand_env_save(*fnamep);
9562 	    vim_free(*bufp);	/* free any allocated file name */
9563 	    *bufp = *fnamep;
9564 	    if (*fnamep == NULL)
9565 		return -1;
9566 	}
9567 
9568 	/* When "/." or "/.." is used: force expansion to get rid of it. */
9569 	for (p = *fnamep; *p != NUL; MB_PTR_ADV(p))
9570 	{
9571 	    if (vim_ispathsep(*p)
9572 		    && p[1] == '.'
9573 		    && (p[2] == NUL
9574 			|| vim_ispathsep(p[2])
9575 			|| (p[2] == '.'
9576 			    && (p[3] == NUL || vim_ispathsep(p[3])))))
9577 		break;
9578 	}
9579 
9580 	/* FullName_save() is slow, don't use it when not needed. */
9581 	if (*p != NUL || !vim_isAbsName(*fnamep))
9582 	{
9583 	    *fnamep = FullName_save(*fnamep, *p != NUL);
9584 	    vim_free(*bufp);	/* free any allocated file name */
9585 	    *bufp = *fnamep;
9586 	    if (*fnamep == NULL)
9587 		return -1;
9588 	}
9589 
9590 #ifdef WIN3264
9591 # if _WIN32_WINNT >= 0x0500
9592 	if (vim_strchr(*fnamep, '~') != NULL)
9593 	{
9594 	    /* Expand 8.3 filename to full path.  Needed to make sure the same
9595 	     * file does not have two different names.
9596 	     * Note: problem does not occur if _WIN32_WINNT < 0x0500. */
9597 	    p = alloc(_MAX_PATH + 1);
9598 	    if (p != NULL)
9599 	    {
9600 		if (GetLongPathName((LPSTR)*fnamep, (LPSTR)p, _MAX_PATH))
9601 		{
9602 		    vim_free(*bufp);
9603 		    *bufp = *fnamep = p;
9604 		}
9605 		else
9606 		    vim_free(p);
9607 	    }
9608 	}
9609 # endif
9610 #endif
9611 	/* Append a path separator to a directory. */
9612 	if (mch_isdir(*fnamep))
9613 	{
9614 	    /* Make room for one or two extra characters. */
9615 	    *fnamep = vim_strnsave(*fnamep, (int)STRLEN(*fnamep) + 2);
9616 	    vim_free(*bufp);	/* free any allocated file name */
9617 	    *bufp = *fnamep;
9618 	    if (*fnamep == NULL)
9619 		return -1;
9620 	    add_pathsep(*fnamep);
9621 	}
9622     }
9623 
9624     /* ":." - path relative to the current directory */
9625     /* ":~" - path relative to the home directory */
9626     /* ":8" - shortname path - postponed till after */
9627     while (src[*usedlen] == ':'
9628 		  && ((c = src[*usedlen + 1]) == '.' || c == '~' || c == '8'))
9629     {
9630 	*usedlen += 2;
9631 	if (c == '8')
9632 	{
9633 #ifdef WIN3264
9634 	    has_shortname = 1; /* Postpone this. */
9635 #endif
9636 	    continue;
9637 	}
9638 	pbuf = NULL;
9639 	/* Need full path first (use expand_env() to remove a "~/") */
9640 	if (!has_fullname)
9641 	{
9642 	    if (c == '.' && **fnamep == '~')
9643 		p = pbuf = expand_env_save(*fnamep);
9644 	    else
9645 		p = pbuf = FullName_save(*fnamep, FALSE);
9646 	}
9647 	else
9648 	    p = *fnamep;
9649 
9650 	has_fullname = 0;
9651 
9652 	if (p != NULL)
9653 	{
9654 	    if (c == '.')
9655 	    {
9656 		mch_dirname(dirname, MAXPATHL);
9657 		s = shorten_fname(p, dirname);
9658 		if (s != NULL)
9659 		{
9660 		    *fnamep = s;
9661 		    if (pbuf != NULL)
9662 		    {
9663 			vim_free(*bufp);   /* free any allocated file name */
9664 			*bufp = pbuf;
9665 			pbuf = NULL;
9666 		    }
9667 		}
9668 	    }
9669 	    else
9670 	    {
9671 		home_replace(NULL, p, dirname, MAXPATHL, TRUE);
9672 		/* Only replace it when it starts with '~' */
9673 		if (*dirname == '~')
9674 		{
9675 		    s = vim_strsave(dirname);
9676 		    if (s != NULL)
9677 		    {
9678 			*fnamep = s;
9679 			vim_free(*bufp);
9680 			*bufp = s;
9681 		    }
9682 		}
9683 	    }
9684 	    vim_free(pbuf);
9685 	}
9686     }
9687 
9688     tail = gettail(*fnamep);
9689     *fnamelen = (int)STRLEN(*fnamep);
9690 
9691     /* ":h" - head, remove "/file_name", can be repeated  */
9692     /* Don't remove the first "/" or "c:\" */
9693     while (src[*usedlen] == ':' && src[*usedlen + 1] == 'h')
9694     {
9695 	valid |= VALID_HEAD;
9696 	*usedlen += 2;
9697 	s = get_past_head(*fnamep);
9698 	while (tail > s && after_pathsep(s, tail))
9699 	    MB_PTR_BACK(*fnamep, tail);
9700 	*fnamelen = (int)(tail - *fnamep);
9701 #ifdef VMS
9702 	if (*fnamelen > 0)
9703 	    *fnamelen += 1; /* the path separator is part of the path */
9704 #endif
9705 	if (*fnamelen == 0)
9706 	{
9707 	    /* Result is empty.  Turn it into "." to make ":cd %:h" work. */
9708 	    p = vim_strsave((char_u *)".");
9709 	    if (p == NULL)
9710 		return -1;
9711 	    vim_free(*bufp);
9712 	    *bufp = *fnamep = tail = p;
9713 	    *fnamelen = 1;
9714 	}
9715 	else
9716 	{
9717 	    while (tail > s && !after_pathsep(s, tail))
9718 		MB_PTR_BACK(*fnamep, tail);
9719 	}
9720     }
9721 
9722     /* ":8" - shortname  */
9723     if (src[*usedlen] == ':' && src[*usedlen + 1] == '8')
9724     {
9725 	*usedlen += 2;
9726 #ifdef WIN3264
9727 	has_shortname = 1;
9728 #endif
9729     }
9730 
9731 #ifdef WIN3264
9732     /*
9733      * Handle ":8" after we have done 'heads' and before we do 'tails'.
9734      */
9735     if (has_shortname)
9736     {
9737 	/* Copy the string if it is shortened by :h and when it wasn't copied
9738 	 * yet, because we are going to change it in place.  Avoids changing
9739 	 * the buffer name for "%:8". */
9740 	if (*fnamelen < (int)STRLEN(*fnamep) || *fnamep == fname_start)
9741 	{
9742 	    p = vim_strnsave(*fnamep, *fnamelen);
9743 	    if (p == NULL)
9744 		return -1;
9745 	    vim_free(*bufp);
9746 	    *bufp = *fnamep = p;
9747 	}
9748 
9749 	/* Split into two implementations - makes it easier.  First is where
9750 	 * there isn't a full name already, second is where there is. */
9751 	if (!has_fullname && !vim_isAbsName(*fnamep))
9752 	{
9753 	    if (shortpath_for_partial(fnamep, bufp, fnamelen) == FAIL)
9754 		return -1;
9755 	}
9756 	else
9757 	{
9758 	    int		l = *fnamelen;
9759 
9760 	    /* Simple case, already have the full-name.
9761 	     * Nearly always shorter, so try first time. */
9762 	    if (get_short_pathname(fnamep, bufp, &l) == FAIL)
9763 		return -1;
9764 
9765 	    if (l == 0)
9766 	    {
9767 		/* Couldn't find the filename, search the paths. */
9768 		l = *fnamelen;
9769 		if (shortpath_for_invalid_fname(fnamep, bufp, &l) == FAIL)
9770 		    return -1;
9771 	    }
9772 	    *fnamelen = l;
9773 	}
9774     }
9775 #endif /* WIN3264 */
9776 
9777     /* ":t" - tail, just the basename */
9778     if (src[*usedlen] == ':' && src[*usedlen + 1] == 't')
9779     {
9780 	*usedlen += 2;
9781 	*fnamelen -= (int)(tail - *fnamep);
9782 	*fnamep = tail;
9783     }
9784 
9785     /* ":e" - extension, can be repeated */
9786     /* ":r" - root, without extension, can be repeated */
9787     while (src[*usedlen] == ':'
9788 	    && (src[*usedlen + 1] == 'e' || src[*usedlen + 1] == 'r'))
9789     {
9790 	/* find a '.' in the tail:
9791 	 * - for second :e: before the current fname
9792 	 * - otherwise: The last '.'
9793 	 */
9794 	if (src[*usedlen + 1] == 'e' && *fnamep > tail)
9795 	    s = *fnamep - 2;
9796 	else
9797 	    s = *fnamep + *fnamelen - 1;
9798 	for ( ; s > tail; --s)
9799 	    if (s[0] == '.')
9800 		break;
9801 	if (src[*usedlen + 1] == 'e')		/* :e */
9802 	{
9803 	    if (s > tail)
9804 	    {
9805 		*fnamelen += (int)(*fnamep - (s + 1));
9806 		*fnamep = s + 1;
9807 #ifdef VMS
9808 		/* cut version from the extension */
9809 		s = *fnamep + *fnamelen - 1;
9810 		for ( ; s > *fnamep; --s)
9811 		    if (s[0] == ';')
9812 			break;
9813 		if (s > *fnamep)
9814 		    *fnamelen = s - *fnamep;
9815 #endif
9816 	    }
9817 	    else if (*fnamep <= tail)
9818 		*fnamelen = 0;
9819 	}
9820 	else				/* :r */
9821 	{
9822 	    if (s > tail)	/* remove one extension */
9823 		*fnamelen = (int)(s - *fnamep);
9824 	}
9825 	*usedlen += 2;
9826     }
9827 
9828     /* ":s?pat?foo?" - substitute */
9829     /* ":gs?pat?foo?" - global substitute */
9830     if (src[*usedlen] == ':'
9831 	    && (src[*usedlen + 1] == 's'
9832 		|| (src[*usedlen + 1] == 'g' && src[*usedlen + 2] == 's')))
9833     {
9834 	char_u	    *str;
9835 	char_u	    *pat;
9836 	char_u	    *sub;
9837 	int	    sep;
9838 	char_u	    *flags;
9839 	int	    didit = FALSE;
9840 
9841 	flags = (char_u *)"";
9842 	s = src + *usedlen + 2;
9843 	if (src[*usedlen + 1] == 'g')
9844 	{
9845 	    flags = (char_u *)"g";
9846 	    ++s;
9847 	}
9848 
9849 	sep = *s++;
9850 	if (sep)
9851 	{
9852 	    /* find end of pattern */
9853 	    p = vim_strchr(s, sep);
9854 	    if (p != NULL)
9855 	    {
9856 		pat = vim_strnsave(s, (int)(p - s));
9857 		if (pat != NULL)
9858 		{
9859 		    s = p + 1;
9860 		    /* find end of substitution */
9861 		    p = vim_strchr(s, sep);
9862 		    if (p != NULL)
9863 		    {
9864 			sub = vim_strnsave(s, (int)(p - s));
9865 			str = vim_strnsave(*fnamep, *fnamelen);
9866 			if (sub != NULL && str != NULL)
9867 			{
9868 			    *usedlen = (int)(p + 1 - src);
9869 			    s = do_string_sub(str, pat, sub, NULL, flags);
9870 			    if (s != NULL)
9871 			    {
9872 				*fnamep = s;
9873 				*fnamelen = (int)STRLEN(s);
9874 				vim_free(*bufp);
9875 				*bufp = s;
9876 				didit = TRUE;
9877 			    }
9878 			}
9879 			vim_free(sub);
9880 			vim_free(str);
9881 		    }
9882 		    vim_free(pat);
9883 		}
9884 	    }
9885 	    /* after using ":s", repeat all the modifiers */
9886 	    if (didit)
9887 		goto repeat;
9888 	}
9889     }
9890 
9891     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'S')
9892     {
9893 	/* vim_strsave_shellescape() needs a NUL terminated string. */
9894 	c = (*fnamep)[*fnamelen];
9895 	if (c != NUL)
9896 	    (*fnamep)[*fnamelen] = NUL;
9897 	p = vim_strsave_shellescape(*fnamep, FALSE, FALSE);
9898 	if (c != NUL)
9899 	    (*fnamep)[*fnamelen] = c;
9900 	if (p == NULL)
9901 	    return -1;
9902 	vim_free(*bufp);
9903 	*bufp = *fnamep = p;
9904 	*fnamelen = (int)STRLEN(p);
9905 	*usedlen += 2;
9906     }
9907 
9908     return valid;
9909 }
9910 
9911 /*
9912  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
9913  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
9914  * "flags" can be "g" to do a global substitute.
9915  * Returns an allocated string, NULL for error.
9916  */
9917     char_u *
9918 do_string_sub(
9919     char_u	*str,
9920     char_u	*pat,
9921     char_u	*sub,
9922     typval_T	*expr,
9923     char_u	*flags)
9924 {
9925     int		sublen;
9926     regmatch_T	regmatch;
9927     int		i;
9928     int		do_all;
9929     char_u	*tail;
9930     char_u	*end;
9931     garray_T	ga;
9932     char_u	*ret;
9933     char_u	*save_cpo;
9934     char_u	*zero_width = NULL;
9935 
9936     /* Make 'cpoptions' empty, so that the 'l' flag doesn't work here */
9937     save_cpo = p_cpo;
9938     p_cpo = empty_option;
9939 
9940     ga_init2(&ga, 1, 200);
9941 
9942     do_all = (flags[0] == 'g');
9943 
9944     regmatch.rm_ic = p_ic;
9945     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
9946     if (regmatch.regprog != NULL)
9947     {
9948 	tail = str;
9949 	end = str + STRLEN(str);
9950 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
9951 	{
9952 	    /* Skip empty match except for first match. */
9953 	    if (regmatch.startp[0] == regmatch.endp[0])
9954 	    {
9955 		if (zero_width == regmatch.startp[0])
9956 		{
9957 		    /* avoid getting stuck on a match with an empty string */
9958 		    i = MB_PTR2LEN(tail);
9959 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
9960 								   (size_t)i);
9961 		    ga.ga_len += i;
9962 		    tail += i;
9963 		    continue;
9964 		}
9965 		zero_width = regmatch.startp[0];
9966 	    }
9967 
9968 	    /*
9969 	     * Get some space for a temporary buffer to do the substitution
9970 	     * into.  It will contain:
9971 	     * - The text up to where the match is.
9972 	     * - The substituted text.
9973 	     * - The text after the match.
9974 	     */
9975 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
9976 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
9977 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
9978 	    {
9979 		ga_clear(&ga);
9980 		break;
9981 	    }
9982 
9983 	    /* copy the text up to where the match is */
9984 	    i = (int)(regmatch.startp[0] - tail);
9985 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
9986 	    /* add the substituted text */
9987 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
9988 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
9989 	    ga.ga_len += i + sublen - 1;
9990 	    tail = regmatch.endp[0];
9991 	    if (*tail == NUL)
9992 		break;
9993 	    if (!do_all)
9994 		break;
9995 	}
9996 
9997 	if (ga.ga_data != NULL)
9998 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
9999 
10000 	vim_regfree(regmatch.regprog);
10001     }
10002 
10003     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
10004     ga_clear(&ga);
10005     if (p_cpo == empty_option)
10006 	p_cpo = save_cpo;
10007     else
10008 	/* Darn, evaluating {sub} expression or {expr} changed the value. */
10009 	free_string_option(save_cpo);
10010 
10011     return ret;
10012 }
10013 
10014     static int
10015 filter_map_one(typval_T *tv, typval_T *expr, int map, int *remp)
10016 {
10017     typval_T	rettv;
10018     typval_T	argv[3];
10019     char_u	buf[NUMBUFLEN];
10020     char_u	*s;
10021     int		retval = FAIL;
10022     int		dummy;
10023 
10024     copy_tv(tv, &vimvars[VV_VAL].vv_tv);
10025     argv[0] = vimvars[VV_KEY].vv_tv;
10026     argv[1] = vimvars[VV_VAL].vv_tv;
10027     if (expr->v_type == VAR_FUNC)
10028     {
10029 	s = expr->vval.v_string;
10030 	if (call_func(s, (int)STRLEN(s), &rettv, 2, argv, NULL,
10031 				     0L, 0L, &dummy, TRUE, NULL, NULL) == FAIL)
10032 	    goto theend;
10033     }
10034     else if (expr->v_type == VAR_PARTIAL)
10035     {
10036 	partial_T   *partial = expr->vval.v_partial;
10037 
10038 	s = partial_name(partial);
10039 	if (call_func(s, (int)STRLEN(s), &rettv, 2, argv, NULL,
10040 				  0L, 0L, &dummy, TRUE, partial, NULL) == FAIL)
10041 	    goto theend;
10042     }
10043     else
10044     {
10045 	s = get_tv_string_buf_chk(expr, buf);
10046 	if (s == NULL)
10047 	    goto theend;
10048 	s = skipwhite(s);
10049 	if (eval1(&s, &rettv, TRUE) == FAIL)
10050 	    goto theend;
10051 	if (*s != NUL)  /* check for trailing chars after expr */
10052 	{
10053 	    EMSG2(_(e_invexpr2), s);
10054 	    goto theend;
10055 	}
10056     }
10057     if (map)
10058     {
10059 	/* map(): replace the list item value */
10060 	clear_tv(tv);
10061 	rettv.v_lock = 0;
10062 	*tv = rettv;
10063     }
10064     else
10065     {
10066 	int	    error = FALSE;
10067 
10068 	/* filter(): when expr is zero remove the item */
10069 	*remp = (get_tv_number_chk(&rettv, &error) == 0);
10070 	clear_tv(&rettv);
10071 	/* On type error, nothing has been removed; return FAIL to stop the
10072 	 * loop.  The error message was given by get_tv_number_chk(). */
10073 	if (error)
10074 	    goto theend;
10075     }
10076     retval = OK;
10077 theend:
10078     clear_tv(&vimvars[VV_VAL].vv_tv);
10079     return retval;
10080 }
10081 
10082 
10083 /*
10084  * Implementation of map() and filter().
10085  */
10086     void
10087 filter_map(typval_T *argvars, typval_T *rettv, int map)
10088 {
10089     typval_T	*expr;
10090     listitem_T	*li, *nli;
10091     list_T	*l = NULL;
10092     dictitem_T	*di;
10093     hashtab_T	*ht;
10094     hashitem_T	*hi;
10095     dict_T	*d = NULL;
10096     typval_T	save_val;
10097     typval_T	save_key;
10098     int		rem;
10099     int		todo;
10100     char_u	*ermsg = (char_u *)(map ? "map()" : "filter()");
10101     char_u	*arg_errmsg = (char_u *)(map ? N_("map() argument")
10102 				   : N_("filter() argument"));
10103     int		save_did_emsg;
10104     int		idx = 0;
10105 
10106     if (argvars[0].v_type == VAR_LIST)
10107     {
10108 	if ((l = argvars[0].vval.v_list) == NULL
10109 	      || (!map && tv_check_lock(l->lv_lock, arg_errmsg, TRUE)))
10110 	    return;
10111     }
10112     else if (argvars[0].v_type == VAR_DICT)
10113     {
10114 	if ((d = argvars[0].vval.v_dict) == NULL
10115 	      || (!map && tv_check_lock(d->dv_lock, arg_errmsg, TRUE)))
10116 	    return;
10117     }
10118     else
10119     {
10120 	EMSG2(_(e_listdictarg), ermsg);
10121 	return;
10122     }
10123 
10124     expr = &argvars[1];
10125     /* On type errors, the preceding call has already displayed an error
10126      * message.  Avoid a misleading error message for an empty string that
10127      * was not passed as argument. */
10128     if (expr->v_type != VAR_UNKNOWN)
10129     {
10130 	prepare_vimvar(VV_VAL, &save_val);
10131 
10132 	/* We reset "did_emsg" to be able to detect whether an error
10133 	 * occurred during evaluation of the expression. */
10134 	save_did_emsg = did_emsg;
10135 	did_emsg = FALSE;
10136 
10137 	prepare_vimvar(VV_KEY, &save_key);
10138 	if (argvars[0].v_type == VAR_DICT)
10139 	{
10140 	    vimvars[VV_KEY].vv_type = VAR_STRING;
10141 
10142 	    ht = &d->dv_hashtab;
10143 	    hash_lock(ht);
10144 	    todo = (int)ht->ht_used;
10145 	    for (hi = ht->ht_array; todo > 0; ++hi)
10146 	    {
10147 		if (!HASHITEM_EMPTY(hi))
10148 		{
10149 		    int r;
10150 
10151 		    --todo;
10152 		    di = HI2DI(hi);
10153 		    if (map &&
10154 			    (tv_check_lock(di->di_tv.v_lock, arg_errmsg, TRUE)
10155 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE)))
10156 			break;
10157 		    vimvars[VV_KEY].vv_str = vim_strsave(di->di_key);
10158 		    r = filter_map_one(&di->di_tv, expr, map, &rem);
10159 		    clear_tv(&vimvars[VV_KEY].vv_tv);
10160 		    if (r == FAIL || did_emsg)
10161 			break;
10162 		    if (!map && rem)
10163 		    {
10164 			if (var_check_fixed(di->di_flags, arg_errmsg, TRUE)
10165 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE))
10166 			    break;
10167 			dictitem_remove(d, di);
10168 		    }
10169 		}
10170 	    }
10171 	    hash_unlock(ht);
10172 	}
10173 	else
10174 	{
10175 	    vimvars[VV_KEY].vv_type = VAR_NUMBER;
10176 
10177 	    for (li = l->lv_first; li != NULL; li = nli)
10178 	    {
10179 		if (map && tv_check_lock(li->li_tv.v_lock, arg_errmsg, TRUE))
10180 		    break;
10181 		nli = li->li_next;
10182 		vimvars[VV_KEY].vv_nr = idx;
10183 		if (filter_map_one(&li->li_tv, expr, map, &rem) == FAIL
10184 								  || did_emsg)
10185 		    break;
10186 		if (!map && rem)
10187 		    listitem_remove(l, li);
10188 		++idx;
10189 	    }
10190 	}
10191 
10192 	restore_vimvar(VV_KEY, &save_key);
10193 	restore_vimvar(VV_VAL, &save_val);
10194 
10195 	did_emsg |= save_did_emsg;
10196     }
10197 
10198     copy_tv(&argvars[0], rettv);
10199 }
10200 
10201 #endif /* defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) */
10202