xref: /vim-8.2.3635/src/eval.c (revision d09a206e)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * eval.c: Expression evaluation.
12  */
13 #define USING_FLOAT_STUFF
14 
15 #include "vim.h"
16 
17 #if defined(FEAT_EVAL) || defined(PROTO)
18 
19 #ifdef VMS
20 # include <float.h>
21 #endif
22 
23 #define DICT_MAXNEST 100	/* maximum nesting of lists and dicts */
24 
25 static char *e_letunexp	= N_("E18: Unexpected characters in :let");
26 static char *e_undefvar = N_("E121: Undefined variable: %s");
27 static char *e_missbrac = N_("E111: Missing ']'");
28 static char *e_dictrange = N_("E719: Cannot use [:] with a Dictionary");
29 static char *e_letwrong = N_("E734: Wrong variable type for %s=");
30 static char *e_illvar = N_("E461: Illegal variable name: %s");
31 #ifdef FEAT_FLOAT
32 static char *e_float_as_string = N_("E806: using Float as a String");
33 #endif
34 
35 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
36 
37 static dictitem_T	globvars_var;		/* variable used for g: */
38 #define globvarht globvardict.dv_hashtab
39 
40 /*
41  * Old Vim variables such as "v:version" are also available without the "v:".
42  * Also in functions.  We need a special hashtable for them.
43  */
44 static hashtab_T	compat_hashtab;
45 
46 /*
47  * When recursively copying lists and dicts we need to remember which ones we
48  * have done to avoid endless recursiveness.  This unique ID is used for that.
49  * The last bit is used for previous_funccal, ignored when comparing.
50  */
51 static int current_copyID = 0;
52 
53 /*
54  * Array to hold the hashtab with variables local to each sourced script.
55  * Each item holds a variable (nameless) that points to the dict_T.
56  */
57 typedef struct
58 {
59     dictitem_T	sv_var;
60     dict_T	sv_dict;
61 } scriptvar_T;
62 
63 static garray_T	    ga_scripts = {0, 0, sizeof(scriptvar_T *), 4, NULL};
64 #define SCRIPT_SV(id) (((scriptvar_T **)ga_scripts.ga_data)[(id) - 1])
65 #define SCRIPT_VARS(id) (SCRIPT_SV(id)->sv_dict.dv_hashtab)
66 
67 static int echo_attr = 0;   /* attributes used for ":echo" */
68 
69 /* The names of packages that once were loaded are remembered. */
70 static garray_T		ga_loaded = {0, 0, sizeof(char_u *), 4, NULL};
71 
72 /*
73  * Info used by a ":for" loop.
74  */
75 typedef struct
76 {
77     int		fi_semicolon;	/* TRUE if ending in '; var]' */
78     int		fi_varcount;	/* nr of variables in the list */
79     listwatch_T	fi_lw;		/* keep an eye on the item used. */
80     list_T	*fi_list;	/* list being used */
81 } forinfo_T;
82 
83 
84 /*
85  * Array to hold the value of v: variables.
86  * The value is in a dictitem, so that it can also be used in the v: scope.
87  * The reason to use this table anyway is for very quick access to the
88  * variables with the VV_ defines.
89  */
90 
91 /* values for vv_flags: */
92 #define VV_COMPAT	1	/* compatible, also used without "v:" */
93 #define VV_RO		2	/* read-only */
94 #define VV_RO_SBX	4	/* read-only in the sandbox */
95 
96 #define VV_NAME(s, t)	s, {{t, 0, {0}}, 0, {0}}
97 
98 static struct vimvar
99 {
100     char	*vv_name;	/* name of variable, without v: */
101     dictitem16_T vv_di;		/* value and name for key (max 16 chars!) */
102     char	vv_flags;	/* VV_COMPAT, VV_RO, VV_RO_SBX */
103 } vimvars[VV_LEN] =
104 {
105     /*
106      * The order here must match the VV_ defines in vim.h!
107      * Initializing a union does not work, leave tv.vval empty to get zero's.
108      */
109     {VV_NAME("count",		 VAR_NUMBER), VV_COMPAT+VV_RO},
110     {VV_NAME("count1",		 VAR_NUMBER), VV_RO},
111     {VV_NAME("prevcount",	 VAR_NUMBER), VV_RO},
112     {VV_NAME("errmsg",		 VAR_STRING), VV_COMPAT},
113     {VV_NAME("warningmsg",	 VAR_STRING), 0},
114     {VV_NAME("statusmsg",	 VAR_STRING), 0},
115     {VV_NAME("shell_error",	 VAR_NUMBER), VV_COMPAT+VV_RO},
116     {VV_NAME("this_session",	 VAR_STRING), VV_COMPAT},
117     {VV_NAME("version",		 VAR_NUMBER), VV_COMPAT+VV_RO},
118     {VV_NAME("lnum",		 VAR_NUMBER), VV_RO_SBX},
119     {VV_NAME("termresponse",	 VAR_STRING), VV_RO},
120     {VV_NAME("fname",		 VAR_STRING), VV_RO},
121     {VV_NAME("lang",		 VAR_STRING), VV_RO},
122     {VV_NAME("lc_time",		 VAR_STRING), VV_RO},
123     {VV_NAME("ctype",		 VAR_STRING), VV_RO},
124     {VV_NAME("charconvert_from", VAR_STRING), VV_RO},
125     {VV_NAME("charconvert_to",	 VAR_STRING), VV_RO},
126     {VV_NAME("fname_in",	 VAR_STRING), VV_RO},
127     {VV_NAME("fname_out",	 VAR_STRING), VV_RO},
128     {VV_NAME("fname_new",	 VAR_STRING), VV_RO},
129     {VV_NAME("fname_diff",	 VAR_STRING), VV_RO},
130     {VV_NAME("cmdarg",		 VAR_STRING), VV_RO},
131     {VV_NAME("foldstart",	 VAR_NUMBER), VV_RO_SBX},
132     {VV_NAME("foldend",		 VAR_NUMBER), VV_RO_SBX},
133     {VV_NAME("folddashes",	 VAR_STRING), VV_RO_SBX},
134     {VV_NAME("foldlevel",	 VAR_NUMBER), VV_RO_SBX},
135     {VV_NAME("progname",	 VAR_STRING), VV_RO},
136     {VV_NAME("servername",	 VAR_STRING), VV_RO},
137     {VV_NAME("dying",		 VAR_NUMBER), VV_RO},
138     {VV_NAME("exception",	 VAR_STRING), VV_RO},
139     {VV_NAME("throwpoint",	 VAR_STRING), VV_RO},
140     {VV_NAME("register",	 VAR_STRING), VV_RO},
141     {VV_NAME("cmdbang",		 VAR_NUMBER), VV_RO},
142     {VV_NAME("insertmode",	 VAR_STRING), VV_RO},
143     {VV_NAME("val",		 VAR_UNKNOWN), VV_RO},
144     {VV_NAME("key",		 VAR_UNKNOWN), VV_RO},
145     {VV_NAME("profiling",	 VAR_NUMBER), VV_RO},
146     {VV_NAME("fcs_reason",	 VAR_STRING), VV_RO},
147     {VV_NAME("fcs_choice",	 VAR_STRING), 0},
148     {VV_NAME("beval_bufnr",	 VAR_NUMBER), VV_RO},
149     {VV_NAME("beval_winnr",	 VAR_NUMBER), VV_RO},
150     {VV_NAME("beval_winid",	 VAR_NUMBER), VV_RO},
151     {VV_NAME("beval_lnum",	 VAR_NUMBER), VV_RO},
152     {VV_NAME("beval_col",	 VAR_NUMBER), VV_RO},
153     {VV_NAME("beval_text",	 VAR_STRING), VV_RO},
154     {VV_NAME("scrollstart",	 VAR_STRING), 0},
155     {VV_NAME("swapname",	 VAR_STRING), VV_RO},
156     {VV_NAME("swapchoice",	 VAR_STRING), 0},
157     {VV_NAME("swapcommand",	 VAR_STRING), VV_RO},
158     {VV_NAME("char",		 VAR_STRING), 0},
159     {VV_NAME("mouse_win",	 VAR_NUMBER), 0},
160     {VV_NAME("mouse_winid",	 VAR_NUMBER), 0},
161     {VV_NAME("mouse_lnum",	 VAR_NUMBER), 0},
162     {VV_NAME("mouse_col",	 VAR_NUMBER), 0},
163     {VV_NAME("operator",	 VAR_STRING), VV_RO},
164     {VV_NAME("searchforward",	 VAR_NUMBER), 0},
165     {VV_NAME("hlsearch",	 VAR_NUMBER), 0},
166     {VV_NAME("oldfiles",	 VAR_LIST), 0},
167     {VV_NAME("windowid",	 VAR_NUMBER), VV_RO},
168     {VV_NAME("progpath",	 VAR_STRING), VV_RO},
169     {VV_NAME("completed_item",	 VAR_DICT), VV_RO},
170     {VV_NAME("option_new",	 VAR_STRING), VV_RO},
171     {VV_NAME("option_old",	 VAR_STRING), VV_RO},
172     {VV_NAME("option_type",	 VAR_STRING), VV_RO},
173     {VV_NAME("errors",		 VAR_LIST), 0},
174     {VV_NAME("false",		 VAR_SPECIAL), VV_RO},
175     {VV_NAME("true",		 VAR_SPECIAL), VV_RO},
176     {VV_NAME("null",		 VAR_SPECIAL), VV_RO},
177     {VV_NAME("none",		 VAR_SPECIAL), VV_RO},
178     {VV_NAME("vim_did_enter",	 VAR_NUMBER), VV_RO},
179     {VV_NAME("testing",		 VAR_NUMBER), 0},
180     {VV_NAME("t_number",	 VAR_NUMBER), VV_RO},
181     {VV_NAME("t_string",	 VAR_NUMBER), VV_RO},
182     {VV_NAME("t_func",		 VAR_NUMBER), VV_RO},
183     {VV_NAME("t_list",		 VAR_NUMBER), VV_RO},
184     {VV_NAME("t_dict",		 VAR_NUMBER), VV_RO},
185     {VV_NAME("t_float",		 VAR_NUMBER), VV_RO},
186     {VV_NAME("t_bool",		 VAR_NUMBER), VV_RO},
187     {VV_NAME("t_none",		 VAR_NUMBER), VV_RO},
188     {VV_NAME("t_job",		 VAR_NUMBER), VV_RO},
189     {VV_NAME("t_channel",	 VAR_NUMBER), VV_RO},
190     {VV_NAME("termrfgresp",	 VAR_STRING), VV_RO},
191     {VV_NAME("termrbgresp",	 VAR_STRING), VV_RO},
192     {VV_NAME("termu7resp",	 VAR_STRING), VV_RO},
193     {VV_NAME("termstyleresp",	VAR_STRING), VV_RO},
194     {VV_NAME("termblinkresp",	VAR_STRING), VV_RO},
195 };
196 
197 /* shorthand */
198 #define vv_type		vv_di.di_tv.v_type
199 #define vv_nr		vv_di.di_tv.vval.v_number
200 #define vv_float	vv_di.di_tv.vval.v_float
201 #define vv_str		vv_di.di_tv.vval.v_string
202 #define vv_list		vv_di.di_tv.vval.v_list
203 #define vv_dict		vv_di.di_tv.vval.v_dict
204 #define vv_tv		vv_di.di_tv
205 
206 static dictitem_T	vimvars_var;		/* variable used for v: */
207 #define vimvarht  vimvardict.dv_hashtab
208 
209 static int ex_let_vars(char_u *arg, typval_T *tv, int copy, int semicolon, int var_count, char_u *nextchars);
210 static char_u *skip_var_list(char_u *arg, int *var_count, int *semicolon);
211 static char_u *skip_var_one(char_u *arg);
212 static void list_glob_vars(int *first);
213 static void list_buf_vars(int *first);
214 static void list_win_vars(int *first);
215 static void list_tab_vars(int *first);
216 static void list_vim_vars(int *first);
217 static void list_script_vars(int *first);
218 static char_u *list_arg_vars(exarg_T *eap, char_u *arg, int *first);
219 static char_u *ex_let_one(char_u *arg, typval_T *tv, int copy, char_u *endchars, char_u *op);
220 static void set_var_lval(lval_T *lp, char_u *endp, typval_T *rettv, int copy, char_u *op);
221 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
222 static void ex_unletlock(exarg_T *eap, char_u *argstart, int deep);
223 static int do_unlet_var(lval_T *lp, char_u *name_end, int forceit);
224 static int do_lock_var(lval_T *lp, char_u *name_end, int deep, int lock);
225 static void item_lock(typval_T *tv, int deep, int lock);
226 
227 static int eval2(char_u **arg, typval_T *rettv, int evaluate);
228 static int eval3(char_u **arg, typval_T *rettv, int evaluate);
229 static int eval4(char_u **arg, typval_T *rettv, int evaluate);
230 static int eval5(char_u **arg, typval_T *rettv, int evaluate);
231 static int eval6(char_u **arg, typval_T *rettv, int evaluate, int want_string);
232 static int eval7(char_u **arg, typval_T *rettv, int evaluate, int want_string);
233 
234 static int eval_index(char_u **arg, typval_T *rettv, int evaluate, int verbose);
235 static int get_string_tv(char_u **arg, typval_T *rettv, int evaluate);
236 static int get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate);
237 static int free_unref_items(int copyID);
238 static int get_env_tv(char_u **arg, typval_T *rettv, int evaluate);
239 static int get_env_len(char_u **arg);
240 static char_u * make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
241 static void check_vars(char_u *name, int len);
242 static typval_T *alloc_string_tv(char_u *string);
243 static void delete_var(hashtab_T *ht, hashitem_T *hi);
244 static void list_one_var(dictitem_T *v, char_u *prefix, int *first);
245 static void list_one_var_a(char_u *prefix, char_u *name, int type, char_u *string, int *first);
246 static char_u *find_option_end(char_u **arg, int *opt_flags);
247 
248 /* for VIM_VERSION_ defines */
249 #include "version.h"
250 
251 
252 #if defined(EBCDIC) || defined(PROTO)
253 /*
254  * Compare struct fst by function name.
255  */
256     static int
257 compare_func_name(const void *s1, const void *s2)
258 {
259     struct fst *p1 = (struct fst *)s1;
260     struct fst *p2 = (struct fst *)s2;
261 
262     return STRCMP(p1->f_name, p2->f_name);
263 }
264 
265 /*
266  * Sort the function table by function name.
267  * The sorting of the table above is ASCII dependant.
268  * On machines using EBCDIC we have to sort it.
269  */
270     static void
271 sortFunctions(void)
272 {
273     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
274 
275     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
276 }
277 #endif
278 
279 
280 /*
281  * Initialize the global and v: variables.
282  */
283     void
284 eval_init(void)
285 {
286     int		    i;
287     struct vimvar   *p;
288 
289     init_var_dict(&globvardict, &globvars_var, VAR_DEF_SCOPE);
290     init_var_dict(&vimvardict, &vimvars_var, VAR_SCOPE);
291     vimvardict.dv_lock = VAR_FIXED;
292     hash_init(&compat_hashtab);
293     func_init();
294 
295     for (i = 0; i < VV_LEN; ++i)
296     {
297 	p = &vimvars[i];
298 	if (STRLEN(p->vv_name) > 16)
299 	{
300 	    IEMSG("INTERNAL: name too long, increase size of dictitem16_T");
301 	    getout(1);
302 	}
303 	STRCPY(p->vv_di.di_key, p->vv_name);
304 	if (p->vv_flags & VV_RO)
305 	    p->vv_di.di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
306 	else if (p->vv_flags & VV_RO_SBX)
307 	    p->vv_di.di_flags = DI_FLAGS_RO_SBX | DI_FLAGS_FIX;
308 	else
309 	    p->vv_di.di_flags = DI_FLAGS_FIX;
310 
311 	/* add to v: scope dict, unless the value is not always available */
312 	if (p->vv_type != VAR_UNKNOWN)
313 	    hash_add(&vimvarht, p->vv_di.di_key);
314 	if (p->vv_flags & VV_COMPAT)
315 	    /* add to compat scope dict */
316 	    hash_add(&compat_hashtab, p->vv_di.di_key);
317     }
318     vimvars[VV_VERSION].vv_nr = VIM_VERSION_100;
319 
320     set_vim_var_nr(VV_SEARCHFORWARD, 1L);
321     set_vim_var_nr(VV_HLSEARCH, 1L);
322     set_vim_var_dict(VV_COMPLETED_ITEM, dict_alloc());
323     set_vim_var_list(VV_ERRORS, list_alloc());
324 
325     set_vim_var_nr(VV_FALSE, VVAL_FALSE);
326     set_vim_var_nr(VV_TRUE, VVAL_TRUE);
327     set_vim_var_nr(VV_NONE, VVAL_NONE);
328     set_vim_var_nr(VV_NULL, VVAL_NULL);
329 
330     set_vim_var_nr(VV_TYPE_NUMBER,  VAR_TYPE_NUMBER);
331     set_vim_var_nr(VV_TYPE_STRING,  VAR_TYPE_STRING);
332     set_vim_var_nr(VV_TYPE_FUNC,    VAR_TYPE_FUNC);
333     set_vim_var_nr(VV_TYPE_LIST,    VAR_TYPE_LIST);
334     set_vim_var_nr(VV_TYPE_DICT,    VAR_TYPE_DICT);
335     set_vim_var_nr(VV_TYPE_FLOAT,   VAR_TYPE_FLOAT);
336     set_vim_var_nr(VV_TYPE_BOOL,    VAR_TYPE_BOOL);
337     set_vim_var_nr(VV_TYPE_NONE,    VAR_TYPE_NONE);
338     set_vim_var_nr(VV_TYPE_JOB,     VAR_TYPE_JOB);
339     set_vim_var_nr(VV_TYPE_CHANNEL, VAR_TYPE_CHANNEL);
340 
341     set_reg_var(0);  /* default for v:register is not 0 but '"' */
342 
343 #ifdef EBCDIC
344     /*
345      * Sort the function table, to enable binary search.
346      */
347     sortFunctions();
348 #endif
349 }
350 
351 #if defined(EXITFREE) || defined(PROTO)
352     void
353 eval_clear(void)
354 {
355     int		    i;
356     struct vimvar   *p;
357 
358     for (i = 0; i < VV_LEN; ++i)
359     {
360 	p = &vimvars[i];
361 	if (p->vv_di.di_tv.v_type == VAR_STRING)
362 	{
363 	    vim_free(p->vv_str);
364 	    p->vv_str = NULL;
365 	}
366 	else if (p->vv_di.di_tv.v_type == VAR_LIST)
367 	{
368 	    list_unref(p->vv_list);
369 	    p->vv_list = NULL;
370 	}
371     }
372     hash_clear(&vimvarht);
373     hash_init(&vimvarht);  /* garbage_collect() will access it */
374     hash_clear(&compat_hashtab);
375 
376     free_scriptnames();
377 # if defined(FEAT_CMDL_COMPL)
378     free_locales();
379 # endif
380 
381     /* global variables */
382     vars_clear(&globvarht);
383 
384     /* autoloaded script names */
385     ga_clear_strings(&ga_loaded);
386 
387     /* Script-local variables. First clear all the variables and in a second
388      * loop free the scriptvar_T, because a variable in one script might hold
389      * a reference to the whole scope of another script. */
390     for (i = 1; i <= ga_scripts.ga_len; ++i)
391 	vars_clear(&SCRIPT_VARS(i));
392     for (i = 1; i <= ga_scripts.ga_len; ++i)
393 	vim_free(SCRIPT_SV(i));
394     ga_clear(&ga_scripts);
395 
396     /* unreferenced lists and dicts */
397     (void)garbage_collect(FALSE);
398 
399     /* functions */
400     free_all_functions();
401 }
402 #endif
403 
404 
405 /*
406  * Set an internal variable to a string value. Creates the variable if it does
407  * not already exist.
408  */
409     void
410 set_internal_string_var(char_u *name, char_u *value)
411 {
412     char_u	*val;
413     typval_T	*tvp;
414 
415     val = vim_strsave(value);
416     if (val != NULL)
417     {
418 	tvp = alloc_string_tv(val);
419 	if (tvp != NULL)
420 	{
421 	    set_var(name, tvp, FALSE);
422 	    free_tv(tvp);
423 	}
424     }
425 }
426 
427 static lval_T	*redir_lval = NULL;
428 #define EVALCMD_BUSY (redir_lval == (lval_T *)&redir_lval)
429 static garray_T redir_ga;	/* only valid when redir_lval is not NULL */
430 static char_u	*redir_endp = NULL;
431 static char_u	*redir_varname = NULL;
432 
433 /*
434  * Start recording command output to a variable
435  * When "append" is TRUE append to an existing variable.
436  * Returns OK if successfully completed the setup.  FAIL otherwise.
437  */
438     int
439 var_redir_start(char_u *name, int append)
440 {
441     int		save_emsg;
442     int		err;
443     typval_T	tv;
444 
445     /* Catch a bad name early. */
446     if (!eval_isnamec1(*name))
447     {
448 	EMSG(_(e_invarg));
449 	return FAIL;
450     }
451 
452     /* Make a copy of the name, it is used in redir_lval until redir ends. */
453     redir_varname = vim_strsave(name);
454     if (redir_varname == NULL)
455 	return FAIL;
456 
457     redir_lval = (lval_T *)alloc_clear((unsigned)sizeof(lval_T));
458     if (redir_lval == NULL)
459     {
460 	var_redir_stop();
461 	return FAIL;
462     }
463 
464     /* The output is stored in growarray "redir_ga" until redirection ends. */
465     ga_init2(&redir_ga, (int)sizeof(char), 500);
466 
467     /* Parse the variable name (can be a dict or list entry). */
468     redir_endp = get_lval(redir_varname, NULL, redir_lval, FALSE, FALSE, 0,
469 							     FNE_CHECK_START);
470     if (redir_endp == NULL || redir_lval->ll_name == NULL || *redir_endp != NUL)
471     {
472 	clear_lval(redir_lval);
473 	if (redir_endp != NULL && *redir_endp != NUL)
474 	    /* Trailing characters are present after the variable name */
475 	    EMSG(_(e_trailing));
476 	else
477 	    EMSG(_(e_invarg));
478 	redir_endp = NULL;  /* don't store a value, only cleanup */
479 	var_redir_stop();
480 	return FAIL;
481     }
482 
483     /* check if we can write to the variable: set it to or append an empty
484      * string */
485     save_emsg = did_emsg;
486     did_emsg = FALSE;
487     tv.v_type = VAR_STRING;
488     tv.vval.v_string = (char_u *)"";
489     if (append)
490 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, (char_u *)".");
491     else
492 	set_var_lval(redir_lval, redir_endp, &tv, TRUE, (char_u *)"=");
493     clear_lval(redir_lval);
494     err = did_emsg;
495     did_emsg |= save_emsg;
496     if (err)
497     {
498 	redir_endp = NULL;  /* don't store a value, only cleanup */
499 	var_redir_stop();
500 	return FAIL;
501     }
502 
503     return OK;
504 }
505 
506 /*
507  * Append "value[value_len]" to the variable set by var_redir_start().
508  * The actual appending is postponed until redirection ends, because the value
509  * appended may in fact be the string we write to, changing it may cause freed
510  * memory to be used:
511  *   :redir => foo
512  *   :let foo
513  *   :redir END
514  */
515     void
516 var_redir_str(char_u *value, int value_len)
517 {
518     int		len;
519 
520     if (redir_lval == NULL)
521 	return;
522 
523     if (value_len == -1)
524 	len = (int)STRLEN(value);	/* Append the entire string */
525     else
526 	len = value_len;		/* Append only "value_len" characters */
527 
528     if (ga_grow(&redir_ga, len) == OK)
529     {
530 	mch_memmove((char *)redir_ga.ga_data + redir_ga.ga_len, value, len);
531 	redir_ga.ga_len += len;
532     }
533     else
534 	var_redir_stop();
535 }
536 
537 /*
538  * Stop redirecting command output to a variable.
539  * Frees the allocated memory.
540  */
541     void
542 var_redir_stop(void)
543 {
544     typval_T	tv;
545 
546     if (EVALCMD_BUSY)
547     {
548 	redir_lval = NULL;
549 	return;
550     }
551 
552     if (redir_lval != NULL)
553     {
554 	/* If there was no error: assign the text to the variable. */
555 	if (redir_endp != NULL)
556 	{
557 	    ga_append(&redir_ga, NUL);  /* Append the trailing NUL. */
558 	    tv.v_type = VAR_STRING;
559 	    tv.vval.v_string = redir_ga.ga_data;
560 	    /* Call get_lval() again, if it's inside a Dict or List it may
561 	     * have changed. */
562 	    redir_endp = get_lval(redir_varname, NULL, redir_lval,
563 					FALSE, FALSE, 0, FNE_CHECK_START);
564 	    if (redir_endp != NULL && redir_lval->ll_name != NULL)
565 		set_var_lval(redir_lval, redir_endp, &tv, FALSE, (char_u *)".");
566 	    clear_lval(redir_lval);
567 	}
568 
569 	/* free the collected output */
570 	vim_free(redir_ga.ga_data);
571 	redir_ga.ga_data = NULL;
572 
573 	vim_free(redir_lval);
574 	redir_lval = NULL;
575     }
576     vim_free(redir_varname);
577     redir_varname = NULL;
578 }
579 
580 # if defined(FEAT_MBYTE) || defined(PROTO)
581     int
582 eval_charconvert(
583     char_u	*enc_from,
584     char_u	*enc_to,
585     char_u	*fname_from,
586     char_u	*fname_to)
587 {
588     int		err = FALSE;
589 
590     set_vim_var_string(VV_CC_FROM, enc_from, -1);
591     set_vim_var_string(VV_CC_TO, enc_to, -1);
592     set_vim_var_string(VV_FNAME_IN, fname_from, -1);
593     set_vim_var_string(VV_FNAME_OUT, fname_to, -1);
594     if (eval_to_bool(p_ccv, &err, NULL, FALSE))
595 	err = TRUE;
596     set_vim_var_string(VV_CC_FROM, NULL, -1);
597     set_vim_var_string(VV_CC_TO, NULL, -1);
598     set_vim_var_string(VV_FNAME_IN, NULL, -1);
599     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
600 
601     if (err)
602 	return FAIL;
603     return OK;
604 }
605 # endif
606 
607 # if defined(FEAT_POSTSCRIPT) || defined(PROTO)
608     int
609 eval_printexpr(char_u *fname, char_u *args)
610 {
611     int		err = FALSE;
612 
613     set_vim_var_string(VV_FNAME_IN, fname, -1);
614     set_vim_var_string(VV_CMDARG, args, -1);
615     if (eval_to_bool(p_pexpr, &err, NULL, FALSE))
616 	err = TRUE;
617     set_vim_var_string(VV_FNAME_IN, NULL, -1);
618     set_vim_var_string(VV_CMDARG, NULL, -1);
619 
620     if (err)
621     {
622 	mch_remove(fname);
623 	return FAIL;
624     }
625     return OK;
626 }
627 # endif
628 
629 # if defined(FEAT_DIFF) || defined(PROTO)
630     void
631 eval_diff(
632     char_u	*origfile,
633     char_u	*newfile,
634     char_u	*outfile)
635 {
636     int		err = FALSE;
637 
638     set_vim_var_string(VV_FNAME_IN, origfile, -1);
639     set_vim_var_string(VV_FNAME_NEW, newfile, -1);
640     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
641     (void)eval_to_bool(p_dex, &err, NULL, FALSE);
642     set_vim_var_string(VV_FNAME_IN, NULL, -1);
643     set_vim_var_string(VV_FNAME_NEW, NULL, -1);
644     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
645 }
646 
647     void
648 eval_patch(
649     char_u	*origfile,
650     char_u	*difffile,
651     char_u	*outfile)
652 {
653     int		err;
654 
655     set_vim_var_string(VV_FNAME_IN, origfile, -1);
656     set_vim_var_string(VV_FNAME_DIFF, difffile, -1);
657     set_vim_var_string(VV_FNAME_OUT, outfile, -1);
658     (void)eval_to_bool(p_pex, &err, NULL, FALSE);
659     set_vim_var_string(VV_FNAME_IN, NULL, -1);
660     set_vim_var_string(VV_FNAME_DIFF, NULL, -1);
661     set_vim_var_string(VV_FNAME_OUT, NULL, -1);
662 }
663 # endif
664 
665 /*
666  * Top level evaluation function, returning a boolean.
667  * Sets "error" to TRUE if there was an error.
668  * Return TRUE or FALSE.
669  */
670     int
671 eval_to_bool(
672     char_u	*arg,
673     int		*error,
674     char_u	**nextcmd,
675     int		skip)	    /* only parse, don't execute */
676 {
677     typval_T	tv;
678     varnumber_T	retval = FALSE;
679 
680     if (skip)
681 	++emsg_skip;
682     if (eval0(arg, &tv, nextcmd, !skip) == FAIL)
683 	*error = TRUE;
684     else
685     {
686 	*error = FALSE;
687 	if (!skip)
688 	{
689 	    retval = (get_tv_number_chk(&tv, error) != 0);
690 	    clear_tv(&tv);
691 	}
692     }
693     if (skip)
694 	--emsg_skip;
695 
696     return (int)retval;
697 }
698 
699     static int
700 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
701 {
702     char_u	*s;
703     int		dummy;
704     char_u	buf[NUMBUFLEN];
705 
706     if (expr->v_type == VAR_FUNC)
707     {
708 	s = expr->vval.v_string;
709 	if (s == NULL || *s == NUL)
710 	    return FAIL;
711 	if (call_func(s, (int)STRLEN(s), rettv, argc, argv, NULL,
712 				     0L, 0L, &dummy, TRUE, NULL, NULL) == FAIL)
713 	    return FAIL;
714     }
715     else if (expr->v_type == VAR_PARTIAL)
716     {
717 	partial_T   *partial = expr->vval.v_partial;
718 
719 	s = partial_name(partial);
720 	if (s == NULL || *s == NUL)
721 	    return FAIL;
722 	if (call_func(s, (int)STRLEN(s), rettv, argc, argv, NULL,
723 				  0L, 0L, &dummy, TRUE, partial, NULL) == FAIL)
724 	    return FAIL;
725     }
726     else
727     {
728 	s = get_tv_string_buf_chk(expr, buf);
729 	if (s == NULL)
730 	    return FAIL;
731 	s = skipwhite(s);
732 	if (eval1(&s, rettv, TRUE) == FAIL)
733 	    return FAIL;
734 	if (*s != NUL)  /* check for trailing chars after expr */
735 	{
736 	    EMSG2(_(e_invexpr2), s);
737 	    return FAIL;
738 	}
739     }
740     return OK;
741 }
742 
743 /*
744  * Like eval_to_bool() but using a typval_T instead of a string.
745  * Works for string, funcref and partial.
746  */
747     int
748 eval_expr_to_bool(typval_T *expr, int *error)
749 {
750     typval_T	rettv;
751     int		res;
752 
753     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
754     {
755 	*error = TRUE;
756 	return FALSE;
757     }
758     res = (get_tv_number_chk(&rettv, error) != 0);
759     clear_tv(&rettv);
760     return res;
761 }
762 
763 /*
764  * Top level evaluation function, returning a string.  If "skip" is TRUE,
765  * only parsing to "nextcmd" is done, without reporting errors.  Return
766  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
767  */
768     char_u *
769 eval_to_string_skip(
770     char_u	*arg,
771     char_u	**nextcmd,
772     int		skip)	    /* only parse, don't execute */
773 {
774     typval_T	tv;
775     char_u	*retval;
776 
777     if (skip)
778 	++emsg_skip;
779     if (eval0(arg, &tv, nextcmd, !skip) == FAIL || skip)
780 	retval = NULL;
781     else
782     {
783 	retval = vim_strsave(get_tv_string(&tv));
784 	clear_tv(&tv);
785     }
786     if (skip)
787 	--emsg_skip;
788 
789     return retval;
790 }
791 
792 /*
793  * Skip over an expression at "*pp".
794  * Return FAIL for an error, OK otherwise.
795  */
796     int
797 skip_expr(char_u **pp)
798 {
799     typval_T	rettv;
800 
801     *pp = skipwhite(*pp);
802     return eval1(pp, &rettv, FALSE);
803 }
804 
805 /*
806  * Top level evaluation function, returning a string.
807  * When "convert" is TRUE convert a List into a sequence of lines and convert
808  * a Float to a String.
809  * Return pointer to allocated memory, or NULL for failure.
810  */
811     char_u *
812 eval_to_string(
813     char_u	*arg,
814     char_u	**nextcmd,
815     int		convert)
816 {
817     typval_T	tv;
818     char_u	*retval;
819     garray_T	ga;
820 #ifdef FEAT_FLOAT
821     char_u	numbuf[NUMBUFLEN];
822 #endif
823 
824     if (eval0(arg, &tv, nextcmd, TRUE) == FAIL)
825 	retval = NULL;
826     else
827     {
828 	if (convert && tv.v_type == VAR_LIST)
829 	{
830 	    ga_init2(&ga, (int)sizeof(char), 80);
831 	    if (tv.vval.v_list != NULL)
832 	    {
833 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
834 		if (tv.vval.v_list->lv_len > 0)
835 		    ga_append(&ga, NL);
836 	    }
837 	    ga_append(&ga, NUL);
838 	    retval = (char_u *)ga.ga_data;
839 	}
840 #ifdef FEAT_FLOAT
841 	else if (convert && tv.v_type == VAR_FLOAT)
842 	{
843 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
844 	    retval = vim_strsave(numbuf);
845 	}
846 #endif
847 	else
848 	    retval = vim_strsave(get_tv_string(&tv));
849 	clear_tv(&tv);
850     }
851 
852     return retval;
853 }
854 
855 /*
856  * Call eval_to_string() without using current local variables and using
857  * textlock.  When "use_sandbox" is TRUE use the sandbox.
858  */
859     char_u *
860 eval_to_string_safe(
861     char_u	*arg,
862     char_u	**nextcmd,
863     int		use_sandbox)
864 {
865     char_u	*retval;
866     void	*save_funccalp;
867 
868     save_funccalp = save_funccal();
869     if (use_sandbox)
870 	++sandbox;
871     ++textlock;
872     retval = eval_to_string(arg, nextcmd, FALSE);
873     if (use_sandbox)
874 	--sandbox;
875     --textlock;
876     restore_funccal(save_funccalp);
877     return retval;
878 }
879 
880 /*
881  * Top level evaluation function, returning a number.
882  * Evaluates "expr" silently.
883  * Returns -1 for an error.
884  */
885     varnumber_T
886 eval_to_number(char_u *expr)
887 {
888     typval_T	rettv;
889     varnumber_T	retval;
890     char_u	*p = skipwhite(expr);
891 
892     ++emsg_off;
893 
894     if (eval1(&p, &rettv, TRUE) == FAIL)
895 	retval = -1;
896     else
897     {
898 	retval = get_tv_number_chk(&rettv, NULL);
899 	clear_tv(&rettv);
900     }
901     --emsg_off;
902 
903     return retval;
904 }
905 
906 /*
907  * Prepare v: variable "idx" to be used.
908  * Save the current typeval in "save_tv".
909  * When not used yet add the variable to the v: hashtable.
910  */
911     static void
912 prepare_vimvar(int idx, typval_T *save_tv)
913 {
914     *save_tv = vimvars[idx].vv_tv;
915     if (vimvars[idx].vv_type == VAR_UNKNOWN)
916 	hash_add(&vimvarht, vimvars[idx].vv_di.di_key);
917 }
918 
919 /*
920  * Restore v: variable "idx" to typeval "save_tv".
921  * When no longer defined, remove the variable from the v: hashtable.
922  */
923     static void
924 restore_vimvar(int idx, typval_T *save_tv)
925 {
926     hashitem_T	*hi;
927 
928     vimvars[idx].vv_tv = *save_tv;
929     if (vimvars[idx].vv_type == VAR_UNKNOWN)
930     {
931 	hi = hash_find(&vimvarht, vimvars[idx].vv_di.di_key);
932 	if (HASHITEM_EMPTY(hi))
933 	    internal_error("restore_vimvar()");
934 	else
935 	    hash_remove(&vimvarht, hi);
936     }
937 }
938 
939 #if defined(FEAT_SPELL) || defined(PROTO)
940 /*
941  * Evaluate an expression to a list with suggestions.
942  * For the "expr:" part of 'spellsuggest'.
943  * Returns NULL when there is an error.
944  */
945     list_T *
946 eval_spell_expr(char_u *badword, char_u *expr)
947 {
948     typval_T	save_val;
949     typval_T	rettv;
950     list_T	*list = NULL;
951     char_u	*p = skipwhite(expr);
952 
953     /* Set "v:val" to the bad word. */
954     prepare_vimvar(VV_VAL, &save_val);
955     vimvars[VV_VAL].vv_type = VAR_STRING;
956     vimvars[VV_VAL].vv_str = badword;
957     if (p_verbose == 0)
958 	++emsg_off;
959 
960     if (eval1(&p, &rettv, TRUE) == OK)
961     {
962 	if (rettv.v_type != VAR_LIST)
963 	    clear_tv(&rettv);
964 	else
965 	    list = rettv.vval.v_list;
966     }
967 
968     if (p_verbose == 0)
969 	--emsg_off;
970     restore_vimvar(VV_VAL, &save_val);
971 
972     return list;
973 }
974 
975 /*
976  * "list" is supposed to contain two items: a word and a number.  Return the
977  * word in "pp" and the number as the return value.
978  * Return -1 if anything isn't right.
979  * Used to get the good word and score from the eval_spell_expr() result.
980  */
981     int
982 get_spellword(list_T *list, char_u **pp)
983 {
984     listitem_T	*li;
985 
986     li = list->lv_first;
987     if (li == NULL)
988 	return -1;
989     *pp = get_tv_string(&li->li_tv);
990 
991     li = li->li_next;
992     if (li == NULL)
993 	return -1;
994     return (int)get_tv_number(&li->li_tv);
995 }
996 #endif
997 
998 /*
999  * Top level evaluation function.
1000  * Returns an allocated typval_T with the result.
1001  * Returns NULL when there is an error.
1002  */
1003     typval_T *
1004 eval_expr(char_u *arg, char_u **nextcmd)
1005 {
1006     typval_T	*tv;
1007 
1008     tv = (typval_T *)alloc(sizeof(typval_T));
1009     if (tv != NULL && eval0(arg, tv, nextcmd, TRUE) == FAIL)
1010     {
1011 	vim_free(tv);
1012 	tv = NULL;
1013     }
1014 
1015     return tv;
1016 }
1017 
1018 
1019 /*
1020  * Call some Vim script function and return the result in "*rettv".
1021  * Uses argv[argc] for the function arguments.  Only Number and String
1022  * arguments are currently supported.
1023  * Returns OK or FAIL.
1024  */
1025     int
1026 call_vim_function(
1027     char_u      *func,
1028     int		argc,
1029     char_u      **argv,
1030     int		safe,		/* use the sandbox */
1031     int		str_arg_only,	/* all arguments are strings */
1032     typval_T	*rettv)
1033 {
1034     typval_T	*argvars;
1035     varnumber_T	n;
1036     int		len;
1037     int		i;
1038     int		doesrange;
1039     void	*save_funccalp = NULL;
1040     int		ret;
1041 
1042     argvars = (typval_T *)alloc((unsigned)((argc + 1) * sizeof(typval_T)));
1043     if (argvars == NULL)
1044 	return FAIL;
1045 
1046     for (i = 0; i < argc; i++)
1047     {
1048 	/* Pass a NULL or empty argument as an empty string */
1049 	if (argv[i] == NULL || *argv[i] == NUL)
1050 	{
1051 	    argvars[i].v_type = VAR_STRING;
1052 	    argvars[i].vval.v_string = (char_u *)"";
1053 	    continue;
1054 	}
1055 
1056 	if (str_arg_only)
1057 	    len = 0;
1058 	else
1059 	{
1060 	    /* Recognize a number argument, the others must be strings. A dash
1061 	     * is a string too. */
1062 	    vim_str2nr(argv[i], NULL, &len, STR2NR_ALL, &n, NULL, 0);
1063 	    if (len == 1 && *argv[i] == '-')
1064 		len = 0;
1065 	}
1066 	if (len != 0 && len == (int)STRLEN(argv[i]))
1067 	{
1068 	    argvars[i].v_type = VAR_NUMBER;
1069 	    argvars[i].vval.v_number = n;
1070 	}
1071 	else
1072 	{
1073 	    argvars[i].v_type = VAR_STRING;
1074 	    argvars[i].vval.v_string = argv[i];
1075 	}
1076     }
1077 
1078     if (safe)
1079     {
1080 	save_funccalp = save_funccal();
1081 	++sandbox;
1082     }
1083 
1084     rettv->v_type = VAR_UNKNOWN;		/* clear_tv() uses this */
1085     ret = call_func(func, (int)STRLEN(func), rettv, argc, argvars, NULL,
1086 		    curwin->w_cursor.lnum, curwin->w_cursor.lnum,
1087 		    &doesrange, TRUE, NULL, NULL);
1088     if (safe)
1089     {
1090 	--sandbox;
1091 	restore_funccal(save_funccalp);
1092     }
1093     vim_free(argvars);
1094 
1095     if (ret == FAIL)
1096 	clear_tv(rettv);
1097 
1098     return ret;
1099 }
1100 
1101 /*
1102  * Call Vim script function "func" and return the result as a number.
1103  * Returns -1 when calling the function fails.
1104  * Uses argv[argc] for the function arguments.
1105  */
1106     varnumber_T
1107 call_func_retnr(
1108     char_u      *func,
1109     int		argc,
1110     char_u      **argv,
1111     int		safe)		/* use the sandbox */
1112 {
1113     typval_T	rettv;
1114     varnumber_T	retval;
1115 
1116     /* All arguments are passed as strings, no conversion to number. */
1117     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
1118 	return -1;
1119 
1120     retval = get_tv_number_chk(&rettv, NULL);
1121     clear_tv(&rettv);
1122     return retval;
1123 }
1124 
1125 #if (defined(FEAT_USR_CMDS) && defined(FEAT_CMDL_COMPL)) \
1126 	|| defined(FEAT_COMPL_FUNC) || defined(PROTO)
1127 
1128 # if (defined(FEAT_USR_CMDS) && defined(FEAT_CMDL_COMPL)) || defined(PROTO)
1129 /*
1130  * Call Vim script function "func" and return the result as a string.
1131  * Returns NULL when calling the function fails.
1132  * Uses argv[argc] for the function arguments.
1133  */
1134     void *
1135 call_func_retstr(
1136     char_u      *func,
1137     int		argc,
1138     char_u      **argv,
1139     int		safe)		/* use the sandbox */
1140 {
1141     typval_T	rettv;
1142     char_u	*retval;
1143 
1144     /* All arguments are passed as strings, no conversion to number. */
1145     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
1146 	return NULL;
1147 
1148     retval = vim_strsave(get_tv_string(&rettv));
1149     clear_tv(&rettv);
1150     return retval;
1151 }
1152 # endif
1153 
1154 /*
1155  * Call Vim script function "func" and return the result as a List.
1156  * Uses argv[argc] for the function arguments.
1157  * Returns NULL when there is something wrong.
1158  */
1159     void *
1160 call_func_retlist(
1161     char_u      *func,
1162     int		argc,
1163     char_u      **argv,
1164     int		safe)		/* use the sandbox */
1165 {
1166     typval_T	rettv;
1167 
1168     /* All arguments are passed as strings, no conversion to number. */
1169     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
1170 	return NULL;
1171 
1172     if (rettv.v_type != VAR_LIST)
1173     {
1174 	clear_tv(&rettv);
1175 	return NULL;
1176     }
1177 
1178     return rettv.vval.v_list;
1179 }
1180 #endif
1181 
1182 
1183 #ifdef FEAT_FOLDING
1184 /*
1185  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
1186  * it in "*cp".  Doesn't give error messages.
1187  */
1188     int
1189 eval_foldexpr(char_u *arg, int *cp)
1190 {
1191     typval_T	tv;
1192     varnumber_T	retval;
1193     char_u	*s;
1194     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
1195 								   OPT_LOCAL);
1196 
1197     ++emsg_off;
1198     if (use_sandbox)
1199 	++sandbox;
1200     ++textlock;
1201     *cp = NUL;
1202     if (eval0(arg, &tv, NULL, TRUE) == FAIL)
1203 	retval = 0;
1204     else
1205     {
1206 	/* If the result is a number, just return the number. */
1207 	if (tv.v_type == VAR_NUMBER)
1208 	    retval = tv.vval.v_number;
1209 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
1210 	    retval = 0;
1211 	else
1212 	{
1213 	    /* If the result is a string, check if there is a non-digit before
1214 	     * the number. */
1215 	    s = tv.vval.v_string;
1216 	    if (!VIM_ISDIGIT(*s) && *s != '-')
1217 		*cp = *s++;
1218 	    retval = atol((char *)s);
1219 	}
1220 	clear_tv(&tv);
1221     }
1222     --emsg_off;
1223     if (use_sandbox)
1224 	--sandbox;
1225     --textlock;
1226 
1227     return (int)retval;
1228 }
1229 #endif
1230 
1231 /*
1232  * ":let"			list all variable values
1233  * ":let var1 var2"		list variable values
1234  * ":let var = expr"		assignment command.
1235  * ":let var += expr"		assignment command.
1236  * ":let var -= expr"		assignment command.
1237  * ":let var .= expr"		assignment command.
1238  * ":let [var1, var2] = expr"	unpack list.
1239  */
1240     void
1241 ex_let(exarg_T *eap)
1242 {
1243     char_u	*arg = eap->arg;
1244     char_u	*expr = NULL;
1245     typval_T	rettv;
1246     int		i;
1247     int		var_count = 0;
1248     int		semicolon = 0;
1249     char_u	op[2];
1250     char_u	*argend;
1251     int		first = TRUE;
1252 
1253     argend = skip_var_list(arg, &var_count, &semicolon);
1254     if (argend == NULL)
1255 	return;
1256     if (argend > arg && argend[-1] == '.')  /* for var.='str' */
1257 	--argend;
1258     expr = skipwhite(argend);
1259     if (*expr != '=' && !(vim_strchr((char_u *)"+-.", *expr) != NULL
1260 			  && expr[1] == '='))
1261     {
1262 	/*
1263 	 * ":let" without "=": list variables
1264 	 */
1265 	if (*arg == '[')
1266 	    EMSG(_(e_invarg));
1267 	else if (!ends_excmd(*arg))
1268 	    /* ":let var1 var2" */
1269 	    arg = list_arg_vars(eap, arg, &first);
1270 	else if (!eap->skip)
1271 	{
1272 	    /* ":let" */
1273 	    list_glob_vars(&first);
1274 	    list_buf_vars(&first);
1275 	    list_win_vars(&first);
1276 	    list_tab_vars(&first);
1277 	    list_script_vars(&first);
1278 	    list_func_vars(&first);
1279 	    list_vim_vars(&first);
1280 	}
1281 	eap->nextcmd = check_nextcmd(arg);
1282     }
1283     else
1284     {
1285 	op[0] = '=';
1286 	op[1] = NUL;
1287 	if (*expr != '=')
1288 	{
1289 	    if (vim_strchr((char_u *)"+-.", *expr) != NULL)
1290 		op[0] = *expr;   /* +=, -= or .= */
1291 	    expr = skipwhite(expr + 2);
1292 	}
1293 	else
1294 	    expr = skipwhite(expr + 1);
1295 
1296 	if (eap->skip)
1297 	    ++emsg_skip;
1298 	i = eval0(expr, &rettv, &eap->nextcmd, !eap->skip);
1299 	if (eap->skip)
1300 	{
1301 	    if (i != FAIL)
1302 		clear_tv(&rettv);
1303 	    --emsg_skip;
1304 	}
1305 	else if (i != FAIL)
1306 	{
1307 	    (void)ex_let_vars(eap->arg, &rettv, FALSE, semicolon, var_count,
1308 									  op);
1309 	    clear_tv(&rettv);
1310 	}
1311     }
1312 }
1313 
1314 /*
1315  * Assign the typevalue "tv" to the variable or variables at "arg_start".
1316  * Handles both "var" with any type and "[var, var; var]" with a list type.
1317  * When "nextchars" is not NULL it points to a string with characters that
1318  * must appear after the variable(s).  Use "+", "-" or "." for add, subtract
1319  * or concatenate.
1320  * Returns OK or FAIL;
1321  */
1322     static int
1323 ex_let_vars(
1324     char_u	*arg_start,
1325     typval_T	*tv,
1326     int		copy,		/* copy values from "tv", don't move */
1327     int		semicolon,	/* from skip_var_list() */
1328     int		var_count,	/* from skip_var_list() */
1329     char_u	*nextchars)
1330 {
1331     char_u	*arg = arg_start;
1332     list_T	*l;
1333     int		i;
1334     listitem_T	*item;
1335     typval_T	ltv;
1336 
1337     if (*arg != '[')
1338     {
1339 	/*
1340 	 * ":let var = expr" or ":for var in list"
1341 	 */
1342 	if (ex_let_one(arg, tv, copy, nextchars, nextchars) == NULL)
1343 	    return FAIL;
1344 	return OK;
1345     }
1346 
1347     /*
1348      * ":let [v1, v2] = list" or ":for [v1, v2] in listlist"
1349      */
1350     if (tv->v_type != VAR_LIST || (l = tv->vval.v_list) == NULL)
1351     {
1352 	EMSG(_(e_listreq));
1353 	return FAIL;
1354     }
1355 
1356     i = list_len(l);
1357     if (semicolon == 0 && var_count < i)
1358     {
1359 	EMSG(_("E687: Less targets than List items"));
1360 	return FAIL;
1361     }
1362     if (var_count - semicolon > i)
1363     {
1364 	EMSG(_("E688: More targets than List items"));
1365 	return FAIL;
1366     }
1367 
1368     item = l->lv_first;
1369     while (*arg != ']')
1370     {
1371 	arg = skipwhite(arg + 1);
1372 	arg = ex_let_one(arg, &item->li_tv, TRUE, (char_u *)",;]", nextchars);
1373 	item = item->li_next;
1374 	if (arg == NULL)
1375 	    return FAIL;
1376 
1377 	arg = skipwhite(arg);
1378 	if (*arg == ';')
1379 	{
1380 	    /* Put the rest of the list (may be empty) in the var after ';'.
1381 	     * Create a new list for this. */
1382 	    l = list_alloc();
1383 	    if (l == NULL)
1384 		return FAIL;
1385 	    while (item != NULL)
1386 	    {
1387 		list_append_tv(l, &item->li_tv);
1388 		item = item->li_next;
1389 	    }
1390 
1391 	    ltv.v_type = VAR_LIST;
1392 	    ltv.v_lock = 0;
1393 	    ltv.vval.v_list = l;
1394 	    l->lv_refcount = 1;
1395 
1396 	    arg = ex_let_one(skipwhite(arg + 1), &ltv, FALSE,
1397 						    (char_u *)"]", nextchars);
1398 	    clear_tv(&ltv);
1399 	    if (arg == NULL)
1400 		return FAIL;
1401 	    break;
1402 	}
1403 	else if (*arg != ',' && *arg != ']')
1404 	{
1405 	    internal_error("ex_let_vars()");
1406 	    return FAIL;
1407 	}
1408     }
1409 
1410     return OK;
1411 }
1412 
1413 /*
1414  * Skip over assignable variable "var" or list of variables "[var, var]".
1415  * Used for ":let varvar = expr" and ":for varvar in expr".
1416  * For "[var, var]" increment "*var_count" for each variable.
1417  * for "[var, var; var]" set "semicolon".
1418  * Return NULL for an error.
1419  */
1420     static char_u *
1421 skip_var_list(
1422     char_u	*arg,
1423     int		*var_count,
1424     int		*semicolon)
1425 {
1426     char_u	*p, *s;
1427 
1428     if (*arg == '[')
1429     {
1430 	/* "[var, var]": find the matching ']'. */
1431 	p = arg;
1432 	for (;;)
1433 	{
1434 	    p = skipwhite(p + 1);	/* skip whites after '[', ';' or ',' */
1435 	    s = skip_var_one(p);
1436 	    if (s == p)
1437 	    {
1438 		EMSG2(_(e_invarg2), p);
1439 		return NULL;
1440 	    }
1441 	    ++*var_count;
1442 
1443 	    p = skipwhite(s);
1444 	    if (*p == ']')
1445 		break;
1446 	    else if (*p == ';')
1447 	    {
1448 		if (*semicolon == 1)
1449 		{
1450 		    EMSG(_("Double ; in list of variables"));
1451 		    return NULL;
1452 		}
1453 		*semicolon = 1;
1454 	    }
1455 	    else if (*p != ',')
1456 	    {
1457 		EMSG2(_(e_invarg2), p);
1458 		return NULL;
1459 	    }
1460 	}
1461 	return p + 1;
1462     }
1463     else
1464 	return skip_var_one(arg);
1465 }
1466 
1467 /*
1468  * Skip one (assignable) variable name, including @r, $VAR, &option, d.key,
1469  * l[idx].
1470  */
1471     static char_u *
1472 skip_var_one(char_u *arg)
1473 {
1474     if (*arg == '@' && arg[1] != NUL)
1475 	return arg + 2;
1476     return find_name_end(*arg == '$' || *arg == '&' ? arg + 1 : arg,
1477 				   NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1478 }
1479 
1480 /*
1481  * List variables for hashtab "ht" with prefix "prefix".
1482  * If "empty" is TRUE also list NULL strings as empty strings.
1483  */
1484     void
1485 list_hashtable_vars(
1486     hashtab_T	*ht,
1487     char_u	*prefix,
1488     int		empty,
1489     int		*first)
1490 {
1491     hashitem_T	*hi;
1492     dictitem_T	*di;
1493     int		todo;
1494 
1495     todo = (int)ht->ht_used;
1496     for (hi = ht->ht_array; todo > 0 && !got_int; ++hi)
1497     {
1498 	if (!HASHITEM_EMPTY(hi))
1499 	{
1500 	    --todo;
1501 	    di = HI2DI(hi);
1502 	    if (empty || di->di_tv.v_type != VAR_STRING
1503 					   || di->di_tv.vval.v_string != NULL)
1504 		list_one_var(di, prefix, first);
1505 	}
1506     }
1507 }
1508 
1509 /*
1510  * List global variables.
1511  */
1512     static void
1513 list_glob_vars(int *first)
1514 {
1515     list_hashtable_vars(&globvarht, (char_u *)"", TRUE, first);
1516 }
1517 
1518 /*
1519  * List buffer variables.
1520  */
1521     static void
1522 list_buf_vars(int *first)
1523 {
1524     list_hashtable_vars(&curbuf->b_vars->dv_hashtab, (char_u *)"b:",
1525 								 TRUE, first);
1526 }
1527 
1528 /*
1529  * List window variables.
1530  */
1531     static void
1532 list_win_vars(int *first)
1533 {
1534     list_hashtable_vars(&curwin->w_vars->dv_hashtab,
1535 						 (char_u *)"w:", TRUE, first);
1536 }
1537 
1538 /*
1539  * List tab page variables.
1540  */
1541     static void
1542 list_tab_vars(int *first)
1543 {
1544     list_hashtable_vars(&curtab->tp_vars->dv_hashtab,
1545 						 (char_u *)"t:", TRUE, first);
1546 }
1547 
1548 /*
1549  * List Vim variables.
1550  */
1551     static void
1552 list_vim_vars(int *first)
1553 {
1554     list_hashtable_vars(&vimvarht, (char_u *)"v:", FALSE, first);
1555 }
1556 
1557 /*
1558  * List script-local variables, if there is a script.
1559  */
1560     static void
1561 list_script_vars(int *first)
1562 {
1563     if (current_SID > 0 && current_SID <= ga_scripts.ga_len)
1564 	list_hashtable_vars(&SCRIPT_VARS(current_SID),
1565 						(char_u *)"s:", FALSE, first);
1566 }
1567 
1568 /*
1569  * List variables in "arg".
1570  */
1571     static char_u *
1572 list_arg_vars(exarg_T *eap, char_u *arg, int *first)
1573 {
1574     int		error = FALSE;
1575     int		len;
1576     char_u	*name;
1577     char_u	*name_start;
1578     char_u	*arg_subsc;
1579     char_u	*tofree;
1580     typval_T    tv;
1581 
1582     while (!ends_excmd(*arg) && !got_int)
1583     {
1584 	if (error || eap->skip)
1585 	{
1586 	    arg = find_name_end(arg, NULL, NULL, FNE_INCL_BR | FNE_CHECK_START);
1587 	    if (!VIM_ISWHITE(*arg) && !ends_excmd(*arg))
1588 	    {
1589 		emsg_severe = TRUE;
1590 		EMSG(_(e_trailing));
1591 		break;
1592 	    }
1593 	}
1594 	else
1595 	{
1596 	    /* get_name_len() takes care of expanding curly braces */
1597 	    name_start = name = arg;
1598 	    len = get_name_len(&arg, &tofree, TRUE, TRUE);
1599 	    if (len <= 0)
1600 	    {
1601 		/* This is mainly to keep test 49 working: when expanding
1602 		 * curly braces fails overrule the exception error message. */
1603 		if (len < 0 && !aborting())
1604 		{
1605 		    emsg_severe = TRUE;
1606 		    EMSG2(_(e_invarg2), arg);
1607 		    break;
1608 		}
1609 		error = TRUE;
1610 	    }
1611 	    else
1612 	    {
1613 		if (tofree != NULL)
1614 		    name = tofree;
1615 		if (get_var_tv(name, len, &tv, NULL, TRUE, FALSE) == FAIL)
1616 		    error = TRUE;
1617 		else
1618 		{
1619 		    /* handle d.key, l[idx], f(expr) */
1620 		    arg_subsc = arg;
1621 		    if (handle_subscript(&arg, &tv, TRUE, TRUE) == FAIL)
1622 			error = TRUE;
1623 		    else
1624 		    {
1625 			if (arg == arg_subsc && len == 2 && name[1] == ':')
1626 			{
1627 			    switch (*name)
1628 			    {
1629 				case 'g': list_glob_vars(first); break;
1630 				case 'b': list_buf_vars(first); break;
1631 				case 'w': list_win_vars(first); break;
1632 				case 't': list_tab_vars(first); break;
1633 				case 'v': list_vim_vars(first); break;
1634 				case 's': list_script_vars(first); break;
1635 				case 'l': list_func_vars(first); break;
1636 				default:
1637 					  EMSG2(_("E738: Can't list variables for %s"), name);
1638 			    }
1639 			}
1640 			else
1641 			{
1642 			    char_u	numbuf[NUMBUFLEN];
1643 			    char_u	*tf;
1644 			    int		c;
1645 			    char_u	*s;
1646 
1647 			    s = echo_string(&tv, &tf, numbuf, 0);
1648 			    c = *arg;
1649 			    *arg = NUL;
1650 			    list_one_var_a((char_u *)"",
1651 				    arg == arg_subsc ? name : name_start,
1652 				    tv.v_type,
1653 				    s == NULL ? (char_u *)"" : s,
1654 				    first);
1655 			    *arg = c;
1656 			    vim_free(tf);
1657 			}
1658 			clear_tv(&tv);
1659 		    }
1660 		}
1661 	    }
1662 
1663 	    vim_free(tofree);
1664 	}
1665 
1666 	arg = skipwhite(arg);
1667     }
1668 
1669     return arg;
1670 }
1671 
1672 /*
1673  * Set one item of ":let var = expr" or ":let [v1, v2] = list" to its value.
1674  * Returns a pointer to the char just after the var name.
1675  * Returns NULL if there is an error.
1676  */
1677     static char_u *
1678 ex_let_one(
1679     char_u	*arg,		/* points to variable name */
1680     typval_T	*tv,		/* value to assign to variable */
1681     int		copy,		/* copy value from "tv" */
1682     char_u	*endchars,	/* valid chars after variable name  or NULL */
1683     char_u	*op)		/* "+", "-", "."  or NULL*/
1684 {
1685     int		c1;
1686     char_u	*name;
1687     char_u	*p;
1688     char_u	*arg_end = NULL;
1689     int		len;
1690     int		opt_flags;
1691     char_u	*tofree = NULL;
1692 
1693     /*
1694      * ":let $VAR = expr": Set environment variable.
1695      */
1696     if (*arg == '$')
1697     {
1698 	/* Find the end of the name. */
1699 	++arg;
1700 	name = arg;
1701 	len = get_env_len(&arg);
1702 	if (len == 0)
1703 	    EMSG2(_(e_invarg2), name - 1);
1704 	else
1705 	{
1706 	    if (op != NULL && (*op == '+' || *op == '-'))
1707 		EMSG2(_(e_letwrong), op);
1708 	    else if (endchars != NULL
1709 			     && vim_strchr(endchars, *skipwhite(arg)) == NULL)
1710 		EMSG(_(e_letunexp));
1711 	    else if (!check_secure())
1712 	    {
1713 		c1 = name[len];
1714 		name[len] = NUL;
1715 		p = get_tv_string_chk(tv);
1716 		if (p != NULL && op != NULL && *op == '.')
1717 		{
1718 		    int	    mustfree = FALSE;
1719 		    char_u  *s = vim_getenv(name, &mustfree);
1720 
1721 		    if (s != NULL)
1722 		    {
1723 			p = tofree = concat_str(s, p);
1724 			if (mustfree)
1725 			    vim_free(s);
1726 		    }
1727 		}
1728 		if (p != NULL)
1729 		{
1730 		    vim_setenv(name, p);
1731 		    if (STRICMP(name, "HOME") == 0)
1732 			init_homedir();
1733 		    else if (didset_vim && STRICMP(name, "VIM") == 0)
1734 			didset_vim = FALSE;
1735 		    else if (didset_vimruntime
1736 					&& STRICMP(name, "VIMRUNTIME") == 0)
1737 			didset_vimruntime = FALSE;
1738 		    arg_end = arg;
1739 		}
1740 		name[len] = c1;
1741 		vim_free(tofree);
1742 	    }
1743 	}
1744     }
1745 
1746     /*
1747      * ":let &option = expr": Set option value.
1748      * ":let &l:option = expr": Set local option value.
1749      * ":let &g:option = expr": Set global option value.
1750      */
1751     else if (*arg == '&')
1752     {
1753 	/* Find the end of the name. */
1754 	p = find_option_end(&arg, &opt_flags);
1755 	if (p == NULL || (endchars != NULL
1756 			      && vim_strchr(endchars, *skipwhite(p)) == NULL))
1757 	    EMSG(_(e_letunexp));
1758 	else
1759 	{
1760 	    long	n;
1761 	    int		opt_type;
1762 	    long	numval;
1763 	    char_u	*stringval = NULL;
1764 	    char_u	*s;
1765 
1766 	    c1 = *p;
1767 	    *p = NUL;
1768 
1769 	    n = (long)get_tv_number(tv);
1770 	    s = get_tv_string_chk(tv);	    /* != NULL if number or string */
1771 	    if (s != NULL && op != NULL && *op != '=')
1772 	    {
1773 		opt_type = get_option_value(arg, &numval,
1774 						       &stringval, opt_flags);
1775 		if ((opt_type == 1 && *op == '.')
1776 			|| (opt_type == 0 && *op != '.'))
1777 		{
1778 		    EMSG2(_(e_letwrong), op);
1779 		    s = NULL;  /* don't set the value */
1780 		}
1781 		else
1782 		{
1783 		    if (opt_type == 1)  /* number */
1784 		    {
1785 			if (*op == '+')
1786 			    n = numval + n;
1787 			else
1788 			    n = numval - n;
1789 		    }
1790 		    else if (opt_type == 0 && stringval != NULL) /* string */
1791 		    {
1792 			s = concat_str(stringval, s);
1793 			vim_free(stringval);
1794 			stringval = s;
1795 		    }
1796 		}
1797 	    }
1798 	    if (s != NULL)
1799 	    {
1800 		set_option_value(arg, n, s, opt_flags);
1801 		arg_end = p;
1802 	    }
1803 	    *p = c1;
1804 	    vim_free(stringval);
1805 	}
1806     }
1807 
1808     /*
1809      * ":let @r = expr": Set register contents.
1810      */
1811     else if (*arg == '@')
1812     {
1813 	++arg;
1814 	if (op != NULL && (*op == '+' || *op == '-'))
1815 	    EMSG2(_(e_letwrong), op);
1816 	else if (endchars != NULL
1817 			 && vim_strchr(endchars, *skipwhite(arg + 1)) == NULL)
1818 	    EMSG(_(e_letunexp));
1819 	else
1820 	{
1821 	    char_u	*ptofree = NULL;
1822 	    char_u	*s;
1823 
1824 	    p = get_tv_string_chk(tv);
1825 	    if (p != NULL && op != NULL && *op == '.')
1826 	    {
1827 		s = get_reg_contents(*arg == '@' ? '"' : *arg, GREG_EXPR_SRC);
1828 		if (s != NULL)
1829 		{
1830 		    p = ptofree = concat_str(s, p);
1831 		    vim_free(s);
1832 		}
1833 	    }
1834 	    if (p != NULL)
1835 	    {
1836 		write_reg_contents(*arg == '@' ? '"' : *arg, p, -1, FALSE);
1837 		arg_end = arg + 1;
1838 	    }
1839 	    vim_free(ptofree);
1840 	}
1841     }
1842 
1843     /*
1844      * ":let var = expr": Set internal variable.
1845      * ":let {expr} = expr": Idem, name made with curly braces
1846      */
1847     else if (eval_isnamec1(*arg) || *arg == '{')
1848     {
1849 	lval_T	lv;
1850 
1851 	p = get_lval(arg, tv, &lv, FALSE, FALSE, 0, FNE_CHECK_START);
1852 	if (p != NULL && lv.ll_name != NULL)
1853 	{
1854 	    if (endchars != NULL && vim_strchr(endchars, *skipwhite(p)) == NULL)
1855 		EMSG(_(e_letunexp));
1856 	    else
1857 	    {
1858 		set_var_lval(&lv, p, tv, copy, op);
1859 		arg_end = p;
1860 	    }
1861 	}
1862 	clear_lval(&lv);
1863     }
1864 
1865     else
1866 	EMSG2(_(e_invarg2), arg);
1867 
1868     return arg_end;
1869 }
1870 
1871 /*
1872  * Get an lval: variable, Dict item or List item that can be assigned a value
1873  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
1874  * "name.key", "name.key[expr]" etc.
1875  * Indexing only works if "name" is an existing List or Dictionary.
1876  * "name" points to the start of the name.
1877  * If "rettv" is not NULL it points to the value to be assigned.
1878  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
1879  * wrong; must end in space or cmd separator.
1880  *
1881  * flags:
1882  *  GLV_QUIET:       do not give error messages
1883  *  GLV_READ_ONLY:   will not change the variable
1884  *  GLV_NO_AUTOLOAD: do not use script autoloading
1885  *
1886  * Returns a pointer to just after the name, including indexes.
1887  * When an evaluation error occurs "lp->ll_name" is NULL;
1888  * Returns NULL for a parsing error.  Still need to free items in "lp"!
1889  */
1890     char_u *
1891 get_lval(
1892     char_u	*name,
1893     typval_T	*rettv,
1894     lval_T	*lp,
1895     int		unlet,
1896     int		skip,
1897     int		flags,	    /* GLV_ values */
1898     int		fne_flags)  /* flags for find_name_end() */
1899 {
1900     char_u	*p;
1901     char_u	*expr_start, *expr_end;
1902     int		cc;
1903     dictitem_T	*v;
1904     typval_T	var1;
1905     typval_T	var2;
1906     int		empty1 = FALSE;
1907     listitem_T	*ni;
1908     char_u	*key = NULL;
1909     int		len;
1910     hashtab_T	*ht;
1911     int		quiet = flags & GLV_QUIET;
1912 
1913     /* Clear everything in "lp". */
1914     vim_memset(lp, 0, sizeof(lval_T));
1915 
1916     if (skip)
1917     {
1918 	/* When skipping just find the end of the name. */
1919 	lp->ll_name = name;
1920 	return find_name_end(name, NULL, NULL, FNE_INCL_BR | fne_flags);
1921     }
1922 
1923     /* Find the end of the name. */
1924     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
1925     if (expr_start != NULL)
1926     {
1927 	/* Don't expand the name when we already know there is an error. */
1928 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
1929 						    && *p != '[' && *p != '.')
1930 	{
1931 	    EMSG(_(e_trailing));
1932 	    return NULL;
1933 	}
1934 
1935 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
1936 	if (lp->ll_exp_name == NULL)
1937 	{
1938 	    /* Report an invalid expression in braces, unless the
1939 	     * expression evaluation has been cancelled due to an
1940 	     * aborting error, an interrupt, or an exception. */
1941 	    if (!aborting() && !quiet)
1942 	    {
1943 		emsg_severe = TRUE;
1944 		EMSG2(_(e_invarg2), name);
1945 		return NULL;
1946 	    }
1947 	}
1948 	lp->ll_name = lp->ll_exp_name;
1949     }
1950     else
1951 	lp->ll_name = name;
1952 
1953     /* Without [idx] or .key we are done. */
1954     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
1955 	return p;
1956 
1957     cc = *p;
1958     *p = NUL;
1959     v = find_var(lp->ll_name, &ht, flags & GLV_NO_AUTOLOAD);
1960     if (v == NULL && !quiet)
1961 	EMSG2(_(e_undefvar), lp->ll_name);
1962     *p = cc;
1963     if (v == NULL)
1964 	return NULL;
1965 
1966     /*
1967      * Loop until no more [idx] or .key is following.
1968      */
1969     lp->ll_tv = &v->di_tv;
1970     var1.v_type = VAR_UNKNOWN;
1971     var2.v_type = VAR_UNKNOWN;
1972     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
1973     {
1974 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
1975 		&& !(lp->ll_tv->v_type == VAR_DICT
1976 					   && lp->ll_tv->vval.v_dict != NULL))
1977 	{
1978 	    if (!quiet)
1979 		EMSG(_("E689: Can only index a List or Dictionary"));
1980 	    return NULL;
1981 	}
1982 	if (lp->ll_range)
1983 	{
1984 	    if (!quiet)
1985 		EMSG(_("E708: [:] must come last"));
1986 	    return NULL;
1987 	}
1988 
1989 	len = -1;
1990 	if (*p == '.')
1991 	{
1992 	    key = p + 1;
1993 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
1994 		;
1995 	    if (len == 0)
1996 	    {
1997 		if (!quiet)
1998 		    EMSG(_(e_emptykey));
1999 		return NULL;
2000 	    }
2001 	    p = key + len;
2002 	}
2003 	else
2004 	{
2005 	    /* Get the index [expr] or the first index [expr: ]. */
2006 	    p = skipwhite(p + 1);
2007 	    if (*p == ':')
2008 		empty1 = TRUE;
2009 	    else
2010 	    {
2011 		empty1 = FALSE;
2012 		if (eval1(&p, &var1, TRUE) == FAIL)	/* recursive! */
2013 		    return NULL;
2014 		if (get_tv_string_chk(&var1) == NULL)
2015 		{
2016 		    /* not a number or string */
2017 		    clear_tv(&var1);
2018 		    return NULL;
2019 		}
2020 	    }
2021 
2022 	    /* Optionally get the second index [ :expr]. */
2023 	    if (*p == ':')
2024 	    {
2025 		if (lp->ll_tv->v_type == VAR_DICT)
2026 		{
2027 		    if (!quiet)
2028 			EMSG(_(e_dictrange));
2029 		    clear_tv(&var1);
2030 		    return NULL;
2031 		}
2032 		if (rettv != NULL && (rettv->v_type != VAR_LIST
2033 					       || rettv->vval.v_list == NULL))
2034 		{
2035 		    if (!quiet)
2036 			EMSG(_("E709: [:] requires a List value"));
2037 		    clear_tv(&var1);
2038 		    return NULL;
2039 		}
2040 		p = skipwhite(p + 1);
2041 		if (*p == ']')
2042 		    lp->ll_empty2 = TRUE;
2043 		else
2044 		{
2045 		    lp->ll_empty2 = FALSE;
2046 		    if (eval1(&p, &var2, TRUE) == FAIL)	/* recursive! */
2047 		    {
2048 			clear_tv(&var1);
2049 			return NULL;
2050 		    }
2051 		    if (get_tv_string_chk(&var2) == NULL)
2052 		    {
2053 			/* not a number or string */
2054 			clear_tv(&var1);
2055 			clear_tv(&var2);
2056 			return NULL;
2057 		    }
2058 		}
2059 		lp->ll_range = TRUE;
2060 	    }
2061 	    else
2062 		lp->ll_range = FALSE;
2063 
2064 	    if (*p != ']')
2065 	    {
2066 		if (!quiet)
2067 		    EMSG(_(e_missbrac));
2068 		clear_tv(&var1);
2069 		clear_tv(&var2);
2070 		return NULL;
2071 	    }
2072 
2073 	    /* Skip to past ']'. */
2074 	    ++p;
2075 	}
2076 
2077 	if (lp->ll_tv->v_type == VAR_DICT)
2078 	{
2079 	    if (len == -1)
2080 	    {
2081 		/* "[key]": get key from "var1" */
2082 		key = get_tv_string_chk(&var1);	/* is number or string */
2083 		if (key == NULL)
2084 		{
2085 		    clear_tv(&var1);
2086 		    return NULL;
2087 		}
2088 	    }
2089 	    lp->ll_list = NULL;
2090 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
2091 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
2092 
2093 	    /* When assigning to a scope dictionary check that a function and
2094 	     * variable name is valid (only variable name unless it is l: or
2095 	     * g: dictionary). Disallow overwriting a builtin function. */
2096 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
2097 	    {
2098 		int prevval;
2099 		int wrong;
2100 
2101 		if (len != -1)
2102 		{
2103 		    prevval = key[len];
2104 		    key[len] = NUL;
2105 		}
2106 		else
2107 		    prevval = 0; /* avoid compiler warning */
2108 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
2109 			       && rettv->v_type == VAR_FUNC
2110 			       && var_check_func_name(key, lp->ll_di == NULL))
2111 			|| !valid_varname(key);
2112 		if (len != -1)
2113 		    key[len] = prevval;
2114 		if (wrong)
2115 		    return NULL;
2116 	    }
2117 
2118 	    if (lp->ll_di == NULL)
2119 	    {
2120 		/* Can't add "v:" variable. */
2121 		if (lp->ll_dict == &vimvardict)
2122 		{
2123 		    EMSG2(_(e_illvar), name);
2124 		    return NULL;
2125 		}
2126 
2127 		/* Key does not exist in dict: may need to add it. */
2128 		if (*p == '[' || *p == '.' || unlet)
2129 		{
2130 		    if (!quiet)
2131 			EMSG2(_(e_dictkey), key);
2132 		    clear_tv(&var1);
2133 		    return NULL;
2134 		}
2135 		if (len == -1)
2136 		    lp->ll_newkey = vim_strsave(key);
2137 		else
2138 		    lp->ll_newkey = vim_strnsave(key, len);
2139 		clear_tv(&var1);
2140 		if (lp->ll_newkey == NULL)
2141 		    p = NULL;
2142 		break;
2143 	    }
2144 	    /* existing variable, need to check if it can be changed */
2145 	    else if ((flags & GLV_READ_ONLY) == 0
2146 			     && var_check_ro(lp->ll_di->di_flags, name, FALSE))
2147 	    {
2148 		clear_tv(&var1);
2149 		return NULL;
2150 	    }
2151 
2152 	    clear_tv(&var1);
2153 	    lp->ll_tv = &lp->ll_di->di_tv;
2154 	}
2155 	else
2156 	{
2157 	    /*
2158 	     * Get the number and item for the only or first index of the List.
2159 	     */
2160 	    if (empty1)
2161 		lp->ll_n1 = 0;
2162 	    else
2163 		/* is number or string */
2164 		lp->ll_n1 = (long)get_tv_number(&var1);
2165 	    clear_tv(&var1);
2166 
2167 	    lp->ll_dict = NULL;
2168 	    lp->ll_list = lp->ll_tv->vval.v_list;
2169 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2170 	    if (lp->ll_li == NULL)
2171 	    {
2172 		if (lp->ll_n1 < 0)
2173 		{
2174 		    lp->ll_n1 = 0;
2175 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
2176 		}
2177 	    }
2178 	    if (lp->ll_li == NULL)
2179 	    {
2180 		clear_tv(&var2);
2181 		if (!quiet)
2182 		    EMSGN(_(e_listidx), lp->ll_n1);
2183 		return NULL;
2184 	    }
2185 
2186 	    /*
2187 	     * May need to find the item or absolute index for the second
2188 	     * index of a range.
2189 	     * When no index given: "lp->ll_empty2" is TRUE.
2190 	     * Otherwise "lp->ll_n2" is set to the second index.
2191 	     */
2192 	    if (lp->ll_range && !lp->ll_empty2)
2193 	    {
2194 		lp->ll_n2 = (long)get_tv_number(&var2);
2195 						    /* is number or string */
2196 		clear_tv(&var2);
2197 		if (lp->ll_n2 < 0)
2198 		{
2199 		    ni = list_find(lp->ll_list, lp->ll_n2);
2200 		    if (ni == NULL)
2201 		    {
2202 			if (!quiet)
2203 			    EMSGN(_(e_listidx), lp->ll_n2);
2204 			return NULL;
2205 		    }
2206 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
2207 		}
2208 
2209 		/* Check that lp->ll_n2 isn't before lp->ll_n1. */
2210 		if (lp->ll_n1 < 0)
2211 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
2212 		if (lp->ll_n2 < lp->ll_n1)
2213 		{
2214 		    if (!quiet)
2215 			EMSGN(_(e_listidx), lp->ll_n2);
2216 		    return NULL;
2217 		}
2218 	    }
2219 
2220 	    lp->ll_tv = &lp->ll_li->li_tv;
2221 	}
2222     }
2223 
2224     clear_tv(&var1);
2225     return p;
2226 }
2227 
2228 /*
2229  * Clear lval "lp" that was filled by get_lval().
2230  */
2231     void
2232 clear_lval(lval_T *lp)
2233 {
2234     vim_free(lp->ll_exp_name);
2235     vim_free(lp->ll_newkey);
2236 }
2237 
2238 /*
2239  * Set a variable that was parsed by get_lval() to "rettv".
2240  * "endp" points to just after the parsed name.
2241  * "op" is NULL, "+" for "+=", "-" for "-=", "." for ".=" or "=" for "=".
2242  */
2243     static void
2244 set_var_lval(
2245     lval_T	*lp,
2246     char_u	*endp,
2247     typval_T	*rettv,
2248     int		copy,
2249     char_u	*op)
2250 {
2251     int		cc;
2252     listitem_T	*ri;
2253     dictitem_T	*di;
2254 
2255     if (lp->ll_tv == NULL)
2256     {
2257 	cc = *endp;
2258 	*endp = NUL;
2259 	if (op != NULL && *op != '=')
2260 	{
2261 	    typval_T tv;
2262 
2263 	    /* handle +=, -= and .= */
2264 	    di = NULL;
2265 	    if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
2266 					     &tv, &di, TRUE, FALSE) == OK)
2267 	    {
2268 		if ((di == NULL
2269 		       || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
2270 			  && !tv_check_lock(di->di_tv.v_lock, lp->ll_name,
2271 								  FALSE)))
2272 			&& tv_op(&tv, rettv, op) == OK)
2273 		    set_var(lp->ll_name, &tv, FALSE);
2274 		clear_tv(&tv);
2275 	    }
2276 	}
2277 	else
2278 	    set_var(lp->ll_name, rettv, copy);
2279 	*endp = cc;
2280     }
2281     else if (tv_check_lock(lp->ll_newkey == NULL
2282 		? lp->ll_tv->v_lock
2283 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
2284 	;
2285     else if (lp->ll_range)
2286     {
2287 	listitem_T *ll_li = lp->ll_li;
2288 	int ll_n1 = lp->ll_n1;
2289 
2290 	/*
2291 	 * Check whether any of the list items is locked
2292 	 */
2293 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
2294 	{
2295 	    if (tv_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
2296 		return;
2297 	    ri = ri->li_next;
2298 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
2299 		break;
2300 	    ll_li = ll_li->li_next;
2301 	    ++ll_n1;
2302 	}
2303 
2304 	/*
2305 	 * Assign the List values to the list items.
2306 	 */
2307 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
2308 	{
2309 	    if (op != NULL && *op != '=')
2310 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
2311 	    else
2312 	    {
2313 		clear_tv(&lp->ll_li->li_tv);
2314 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
2315 	    }
2316 	    ri = ri->li_next;
2317 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
2318 		break;
2319 	    if (lp->ll_li->li_next == NULL)
2320 	    {
2321 		/* Need to add an empty item. */
2322 		if (list_append_number(lp->ll_list, 0) == FAIL)
2323 		{
2324 		    ri = NULL;
2325 		    break;
2326 		}
2327 	    }
2328 	    lp->ll_li = lp->ll_li->li_next;
2329 	    ++lp->ll_n1;
2330 	}
2331 	if (ri != NULL)
2332 	    EMSG(_("E710: List value has more items than target"));
2333 	else if (lp->ll_empty2
2334 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
2335 		: lp->ll_n1 != lp->ll_n2)
2336 	    EMSG(_("E711: List value has not enough items"));
2337     }
2338     else
2339     {
2340 	/*
2341 	 * Assign to a List or Dictionary item.
2342 	 */
2343 	if (lp->ll_newkey != NULL)
2344 	{
2345 	    if (op != NULL && *op != '=')
2346 	    {
2347 		EMSG2(_(e_letwrong), op);
2348 		return;
2349 	    }
2350 
2351 	    /* Need to add an item to the Dictionary. */
2352 	    di = dictitem_alloc(lp->ll_newkey);
2353 	    if (di == NULL)
2354 		return;
2355 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
2356 	    {
2357 		vim_free(di);
2358 		return;
2359 	    }
2360 	    lp->ll_tv = &di->di_tv;
2361 	}
2362 	else if (op != NULL && *op != '=')
2363 	{
2364 	    tv_op(lp->ll_tv, rettv, op);
2365 	    return;
2366 	}
2367 	else
2368 	    clear_tv(lp->ll_tv);
2369 
2370 	/*
2371 	 * Assign the value to the variable or list item.
2372 	 */
2373 	if (copy)
2374 	    copy_tv(rettv, lp->ll_tv);
2375 	else
2376 	{
2377 	    *lp->ll_tv = *rettv;
2378 	    lp->ll_tv->v_lock = 0;
2379 	    init_tv(rettv);
2380 	}
2381     }
2382 }
2383 
2384 /*
2385  * Handle "tv1 += tv2", "tv1 -= tv2" and "tv1 .= tv2"
2386  * Returns OK or FAIL.
2387  */
2388     static int
2389 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
2390 {
2391     varnumber_T	n;
2392     char_u	numbuf[NUMBUFLEN];
2393     char_u	*s;
2394 
2395     /* Can't do anything with a Funcref, Dict, v:true on the right. */
2396     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
2397 						&& tv2->v_type != VAR_SPECIAL)
2398     {
2399 	switch (tv1->v_type)
2400 	{
2401 	    case VAR_UNKNOWN:
2402 	    case VAR_DICT:
2403 	    case VAR_FUNC:
2404 	    case VAR_PARTIAL:
2405 	    case VAR_SPECIAL:
2406 	    case VAR_JOB:
2407 	    case VAR_CHANNEL:
2408 		break;
2409 
2410 	    case VAR_LIST:
2411 		if (*op != '+' || tv2->v_type != VAR_LIST)
2412 		    break;
2413 		/* List += List */
2414 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
2415 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
2416 		return OK;
2417 
2418 	    case VAR_NUMBER:
2419 	    case VAR_STRING:
2420 		if (tv2->v_type == VAR_LIST)
2421 		    break;
2422 		if (*op == '+' || *op == '-')
2423 		{
2424 		    /* nr += nr  or  nr -= nr*/
2425 		    n = get_tv_number(tv1);
2426 #ifdef FEAT_FLOAT
2427 		    if (tv2->v_type == VAR_FLOAT)
2428 		    {
2429 			float_T f = n;
2430 
2431 			if (*op == '+')
2432 			    f += tv2->vval.v_float;
2433 			else
2434 			    f -= tv2->vval.v_float;
2435 			clear_tv(tv1);
2436 			tv1->v_type = VAR_FLOAT;
2437 			tv1->vval.v_float = f;
2438 		    }
2439 		    else
2440 #endif
2441 		    {
2442 			if (*op == '+')
2443 			    n += get_tv_number(tv2);
2444 			else
2445 			    n -= get_tv_number(tv2);
2446 			clear_tv(tv1);
2447 			tv1->v_type = VAR_NUMBER;
2448 			tv1->vval.v_number = n;
2449 		    }
2450 		}
2451 		else
2452 		{
2453 		    if (tv2->v_type == VAR_FLOAT)
2454 			break;
2455 
2456 		    /* str .= str */
2457 		    s = get_tv_string(tv1);
2458 		    s = concat_str(s, get_tv_string_buf(tv2, numbuf));
2459 		    clear_tv(tv1);
2460 		    tv1->v_type = VAR_STRING;
2461 		    tv1->vval.v_string = s;
2462 		}
2463 		return OK;
2464 
2465 	    case VAR_FLOAT:
2466 #ifdef FEAT_FLOAT
2467 		{
2468 		    float_T f;
2469 
2470 		    if (*op == '.' || (tv2->v_type != VAR_FLOAT
2471 				    && tv2->v_type != VAR_NUMBER
2472 				    && tv2->v_type != VAR_STRING))
2473 			break;
2474 		    if (tv2->v_type == VAR_FLOAT)
2475 			f = tv2->vval.v_float;
2476 		    else
2477 			f = get_tv_number(tv2);
2478 		    if (*op == '+')
2479 			tv1->vval.v_float += f;
2480 		    else
2481 			tv1->vval.v_float -= f;
2482 		}
2483 #endif
2484 		return OK;
2485 	}
2486     }
2487 
2488     EMSG2(_(e_letwrong), op);
2489     return FAIL;
2490 }
2491 
2492 /*
2493  * Evaluate the expression used in a ":for var in expr" command.
2494  * "arg" points to "var".
2495  * Set "*errp" to TRUE for an error, FALSE otherwise;
2496  * Return a pointer that holds the info.  Null when there is an error.
2497  */
2498     void *
2499 eval_for_line(
2500     char_u	*arg,
2501     int		*errp,
2502     char_u	**nextcmdp,
2503     int		skip)
2504 {
2505     forinfo_T	*fi;
2506     char_u	*expr;
2507     typval_T	tv;
2508     list_T	*l;
2509 
2510     *errp = TRUE;	/* default: there is an error */
2511 
2512     fi = (forinfo_T *)alloc_clear(sizeof(forinfo_T));
2513     if (fi == NULL)
2514 	return NULL;
2515 
2516     expr = skip_var_list(arg, &fi->fi_varcount, &fi->fi_semicolon);
2517     if (expr == NULL)
2518 	return fi;
2519 
2520     expr = skipwhite(expr);
2521     if (expr[0] != 'i' || expr[1] != 'n' || !VIM_ISWHITE(expr[2]))
2522     {
2523 	EMSG(_("E690: Missing \"in\" after :for"));
2524 	return fi;
2525     }
2526 
2527     if (skip)
2528 	++emsg_skip;
2529     if (eval0(skipwhite(expr + 2), &tv, nextcmdp, !skip) == OK)
2530     {
2531 	*errp = FALSE;
2532 	if (!skip)
2533 	{
2534 	    l = tv.vval.v_list;
2535 	    if (tv.v_type != VAR_LIST)
2536 	    {
2537 		EMSG(_(e_listreq));
2538 		clear_tv(&tv);
2539 	    }
2540 	    else if (l == NULL)
2541 	    {
2542 		/* a null list is like an empty list: do nothing */
2543 		clear_tv(&tv);
2544 	    }
2545 	    else
2546 	    {
2547 		/* No need to increment the refcount, it's already set for the
2548 		 * list being used in "tv". */
2549 		fi->fi_list = l;
2550 		list_add_watch(l, &fi->fi_lw);
2551 		fi->fi_lw.lw_item = l->lv_first;
2552 	    }
2553 	}
2554     }
2555     if (skip)
2556 	--emsg_skip;
2557 
2558     return fi;
2559 }
2560 
2561 /*
2562  * Use the first item in a ":for" list.  Advance to the next.
2563  * Assign the values to the variable (list).  "arg" points to the first one.
2564  * Return TRUE when a valid item was found, FALSE when at end of list or
2565  * something wrong.
2566  */
2567     int
2568 next_for_item(void *fi_void, char_u *arg)
2569 {
2570     forinfo_T	*fi = (forinfo_T *)fi_void;
2571     int		result;
2572     listitem_T	*item;
2573 
2574     item = fi->fi_lw.lw_item;
2575     if (item == NULL)
2576 	result = FALSE;
2577     else
2578     {
2579 	fi->fi_lw.lw_item = item->li_next;
2580 	result = (ex_let_vars(arg, &item->li_tv, TRUE,
2581 			      fi->fi_semicolon, fi->fi_varcount, NULL) == OK);
2582     }
2583     return result;
2584 }
2585 
2586 /*
2587  * Free the structure used to store info used by ":for".
2588  */
2589     void
2590 free_for_info(void *fi_void)
2591 {
2592     forinfo_T    *fi = (forinfo_T *)fi_void;
2593 
2594     if (fi != NULL && fi->fi_list != NULL)
2595     {
2596 	list_rem_watch(fi->fi_list, &fi->fi_lw);
2597 	list_unref(fi->fi_list);
2598     }
2599     vim_free(fi);
2600 }
2601 
2602 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
2603 
2604     void
2605 set_context_for_expression(
2606     expand_T	*xp,
2607     char_u	*arg,
2608     cmdidx_T	cmdidx)
2609 {
2610     int		got_eq = FALSE;
2611     int		c;
2612     char_u	*p;
2613 
2614     if (cmdidx == CMD_let)
2615     {
2616 	xp->xp_context = EXPAND_USER_VARS;
2617 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
2618 	{
2619 	    /* ":let var1 var2 ...": find last space. */
2620 	    for (p = arg + STRLEN(arg); p >= arg; )
2621 	    {
2622 		xp->xp_pattern = p;
2623 		MB_PTR_BACK(arg, p);
2624 		if (VIM_ISWHITE(*p))
2625 		    break;
2626 	    }
2627 	    return;
2628 	}
2629     }
2630     else
2631 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
2632 							  : EXPAND_EXPRESSION;
2633     while ((xp->xp_pattern = vim_strpbrk(arg,
2634 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
2635     {
2636 	c = *xp->xp_pattern;
2637 	if (c == '&')
2638 	{
2639 	    c = xp->xp_pattern[1];
2640 	    if (c == '&')
2641 	    {
2642 		++xp->xp_pattern;
2643 		xp->xp_context = cmdidx != CMD_let || got_eq
2644 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
2645 	    }
2646 	    else if (c != ' ')
2647 	    {
2648 		xp->xp_context = EXPAND_SETTINGS;
2649 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
2650 		    xp->xp_pattern += 2;
2651 
2652 	    }
2653 	}
2654 	else if (c == '$')
2655 	{
2656 	    /* environment variable */
2657 	    xp->xp_context = EXPAND_ENV_VARS;
2658 	}
2659 	else if (c == '=')
2660 	{
2661 	    got_eq = TRUE;
2662 	    xp->xp_context = EXPAND_EXPRESSION;
2663 	}
2664 	else if (c == '#'
2665 		&& xp->xp_context == EXPAND_EXPRESSION)
2666 	{
2667 	    /* Autoload function/variable contains '#'. */
2668 	    break;
2669 	}
2670 	else if ((c == '<' || c == '#')
2671 		&& xp->xp_context == EXPAND_FUNCTIONS
2672 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
2673 	{
2674 	    /* Function name can start with "<SNR>" and contain '#'. */
2675 	    break;
2676 	}
2677 	else if (cmdidx != CMD_let || got_eq)
2678 	{
2679 	    if (c == '"')	    /* string */
2680 	    {
2681 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
2682 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
2683 			++xp->xp_pattern;
2684 		xp->xp_context = EXPAND_NOTHING;
2685 	    }
2686 	    else if (c == '\'')	    /* literal string */
2687 	    {
2688 		/* Trick: '' is like stopping and starting a literal string. */
2689 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
2690 		    /* skip */ ;
2691 		xp->xp_context = EXPAND_NOTHING;
2692 	    }
2693 	    else if (c == '|')
2694 	    {
2695 		if (xp->xp_pattern[1] == '|')
2696 		{
2697 		    ++xp->xp_pattern;
2698 		    xp->xp_context = EXPAND_EXPRESSION;
2699 		}
2700 		else
2701 		    xp->xp_context = EXPAND_COMMANDS;
2702 	    }
2703 	    else
2704 		xp->xp_context = EXPAND_EXPRESSION;
2705 	}
2706 	else
2707 	    /* Doesn't look like something valid, expand as an expression
2708 	     * anyway. */
2709 	    xp->xp_context = EXPAND_EXPRESSION;
2710 	arg = xp->xp_pattern;
2711 	if (*arg != NUL)
2712 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
2713 		/* skip */ ;
2714     }
2715     xp->xp_pattern = arg;
2716 }
2717 
2718 #endif /* FEAT_CMDL_COMPL */
2719 
2720 /*
2721  * ":unlet[!] var1 ... " command.
2722  */
2723     void
2724 ex_unlet(exarg_T *eap)
2725 {
2726     ex_unletlock(eap, eap->arg, 0);
2727 }
2728 
2729 /*
2730  * ":lockvar" and ":unlockvar" commands
2731  */
2732     void
2733 ex_lockvar(exarg_T *eap)
2734 {
2735     char_u	*arg = eap->arg;
2736     int		deep = 2;
2737 
2738     if (eap->forceit)
2739 	deep = -1;
2740     else if (vim_isdigit(*arg))
2741     {
2742 	deep = getdigits(&arg);
2743 	arg = skipwhite(arg);
2744     }
2745 
2746     ex_unletlock(eap, arg, deep);
2747 }
2748 
2749 /*
2750  * ":unlet", ":lockvar" and ":unlockvar" are quite similar.
2751  */
2752     static void
2753 ex_unletlock(
2754     exarg_T	*eap,
2755     char_u	*argstart,
2756     int		deep)
2757 {
2758     char_u	*arg = argstart;
2759     char_u	*name_end;
2760     int		error = FALSE;
2761     lval_T	lv;
2762 
2763     do
2764     {
2765 	/* Parse the name and find the end. */
2766 	name_end = get_lval(arg, NULL, &lv, TRUE, eap->skip || error, 0,
2767 							     FNE_CHECK_START);
2768 	if (lv.ll_name == NULL)
2769 	    error = TRUE;	    /* error but continue parsing */
2770 	if (name_end == NULL || (!VIM_ISWHITE(*name_end)
2771 						   && !ends_excmd(*name_end)))
2772 	{
2773 	    if (name_end != NULL)
2774 	    {
2775 		emsg_severe = TRUE;
2776 		EMSG(_(e_trailing));
2777 	    }
2778 	    if (!(eap->skip || error))
2779 		clear_lval(&lv);
2780 	    break;
2781 	}
2782 
2783 	if (!error && !eap->skip)
2784 	{
2785 	    if (eap->cmdidx == CMD_unlet)
2786 	    {
2787 		if (do_unlet_var(&lv, name_end, eap->forceit) == FAIL)
2788 		    error = TRUE;
2789 	    }
2790 	    else
2791 	    {
2792 		if (do_lock_var(&lv, name_end, deep,
2793 					  eap->cmdidx == CMD_lockvar) == FAIL)
2794 		    error = TRUE;
2795 	    }
2796 	}
2797 
2798 	if (!eap->skip)
2799 	    clear_lval(&lv);
2800 
2801 	arg = skipwhite(name_end);
2802     } while (!ends_excmd(*arg));
2803 
2804     eap->nextcmd = check_nextcmd(arg);
2805 }
2806 
2807     static int
2808 do_unlet_var(
2809     lval_T	*lp,
2810     char_u	*name_end,
2811     int		forceit)
2812 {
2813     int		ret = OK;
2814     int		cc;
2815 
2816     if (lp->ll_tv == NULL)
2817     {
2818 	cc = *name_end;
2819 	*name_end = NUL;
2820 
2821 	/* Normal name or expanded name. */
2822 	if (do_unlet(lp->ll_name, forceit) == FAIL)
2823 	    ret = FAIL;
2824 	*name_end = cc;
2825     }
2826     else if ((lp->ll_list != NULL
2827 		   && tv_check_lock(lp->ll_list->lv_lock, lp->ll_name, FALSE))
2828 	    || (lp->ll_dict != NULL
2829 		  && tv_check_lock(lp->ll_dict->dv_lock, lp->ll_name, FALSE)))
2830 	return FAIL;
2831     else if (lp->ll_range)
2832     {
2833 	listitem_T    *li;
2834 	listitem_T    *ll_li = lp->ll_li;
2835 	int	      ll_n1 = lp->ll_n1;
2836 
2837 	while (ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= ll_n1))
2838 	{
2839 	    li = ll_li->li_next;
2840 	    if (tv_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
2841 		return FAIL;
2842 	    ll_li = li;
2843 	    ++ll_n1;
2844 	}
2845 
2846 	/* Delete a range of List items. */
2847 	while (lp->ll_li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
2848 	{
2849 	    li = lp->ll_li->li_next;
2850 	    listitem_remove(lp->ll_list, lp->ll_li);
2851 	    lp->ll_li = li;
2852 	    ++lp->ll_n1;
2853 	}
2854     }
2855     else
2856     {
2857 	if (lp->ll_list != NULL)
2858 	    /* unlet a List item. */
2859 	    listitem_remove(lp->ll_list, lp->ll_li);
2860 	else
2861 	    /* unlet a Dictionary item. */
2862 	    dictitem_remove(lp->ll_dict, lp->ll_di);
2863     }
2864 
2865     return ret;
2866 }
2867 
2868 /*
2869  * "unlet" a variable.  Return OK if it existed, FAIL if not.
2870  * When "forceit" is TRUE don't complain if the variable doesn't exist.
2871  */
2872     int
2873 do_unlet(char_u *name, int forceit)
2874 {
2875     hashtab_T	*ht;
2876     hashitem_T	*hi;
2877     char_u	*varname;
2878     dict_T	*d;
2879     dictitem_T	*di;
2880 
2881     ht = find_var_ht(name, &varname);
2882     if (ht != NULL && *varname != NUL)
2883     {
2884 	d = get_current_funccal_dict(ht);
2885 	if (d == NULL)
2886 	{
2887 	    if (ht == &globvarht)
2888 		d = &globvardict;
2889 	    else if (ht == &compat_hashtab)
2890 		d = &vimvardict;
2891 	    else
2892 	    {
2893 		di = find_var_in_ht(ht, *name, (char_u *)"", FALSE);
2894 		d = di == NULL ? NULL : di->di_tv.vval.v_dict;
2895 	    }
2896 	    if (d == NULL)
2897 	    {
2898 		internal_error("do_unlet()");
2899 		return FAIL;
2900 	    }
2901 	}
2902 	hi = hash_find(ht, varname);
2903 	if (HASHITEM_EMPTY(hi))
2904 	    hi = find_hi_in_scoped_ht(name, &ht);
2905 	if (hi != NULL && !HASHITEM_EMPTY(hi))
2906 	{
2907 	    di = HI2DI(hi);
2908 	    if (var_check_fixed(di->di_flags, name, FALSE)
2909 		    || var_check_ro(di->di_flags, name, FALSE)
2910 		    || tv_check_lock(d->dv_lock, name, FALSE))
2911 		return FAIL;
2912 
2913 	    delete_var(ht, hi);
2914 	    return OK;
2915 	}
2916     }
2917     if (forceit)
2918 	return OK;
2919     EMSG2(_("E108: No such variable: \"%s\""), name);
2920     return FAIL;
2921 }
2922 
2923 /*
2924  * Lock or unlock variable indicated by "lp".
2925  * "deep" is the levels to go (-1 for unlimited);
2926  * "lock" is TRUE for ":lockvar", FALSE for ":unlockvar".
2927  */
2928     static int
2929 do_lock_var(
2930     lval_T	*lp,
2931     char_u	*name_end,
2932     int		deep,
2933     int		lock)
2934 {
2935     int		ret = OK;
2936     int		cc;
2937     dictitem_T	*di;
2938 
2939     if (deep == 0)	/* nothing to do */
2940 	return OK;
2941 
2942     if (lp->ll_tv == NULL)
2943     {
2944 	cc = *name_end;
2945 	*name_end = NUL;
2946 
2947 	/* Normal name or expanded name. */
2948 	di = find_var(lp->ll_name, NULL, TRUE);
2949 	if (di == NULL)
2950 	    ret = FAIL;
2951 	else if ((di->di_flags & DI_FLAGS_FIX)
2952 			&& di->di_tv.v_type != VAR_DICT
2953 			&& di->di_tv.v_type != VAR_LIST)
2954 	    /* For historic reasons this error is not given for a list or dict.
2955 	     * E.g., the b: dict could be locked/unlocked. */
2956 	    EMSG2(_("E940: Cannot lock or unlock variable %s"), lp->ll_name);
2957 	else
2958 	{
2959 	    if (lock)
2960 		di->di_flags |= DI_FLAGS_LOCK;
2961 	    else
2962 		di->di_flags &= ~DI_FLAGS_LOCK;
2963 	    item_lock(&di->di_tv, deep, lock);
2964 	}
2965 	*name_end = cc;
2966     }
2967     else if (lp->ll_range)
2968     {
2969 	listitem_T    *li = lp->ll_li;
2970 
2971 	/* (un)lock a range of List items. */
2972 	while (li != NULL && (lp->ll_empty2 || lp->ll_n2 >= lp->ll_n1))
2973 	{
2974 	    item_lock(&li->li_tv, deep, lock);
2975 	    li = li->li_next;
2976 	    ++lp->ll_n1;
2977 	}
2978     }
2979     else if (lp->ll_list != NULL)
2980 	/* (un)lock a List item. */
2981 	item_lock(&lp->ll_li->li_tv, deep, lock);
2982     else
2983 	/* (un)lock a Dictionary item. */
2984 	item_lock(&lp->ll_di->di_tv, deep, lock);
2985 
2986     return ret;
2987 }
2988 
2989 /*
2990  * Lock or unlock an item.  "deep" is nr of levels to go.
2991  */
2992     static void
2993 item_lock(typval_T *tv, int deep, int lock)
2994 {
2995     static int	recurse = 0;
2996     list_T	*l;
2997     listitem_T	*li;
2998     dict_T	*d;
2999     hashitem_T	*hi;
3000     int		todo;
3001 
3002     if (recurse >= DICT_MAXNEST)
3003     {
3004 	EMSG(_("E743: variable nested too deep for (un)lock"));
3005 	return;
3006     }
3007     if (deep == 0)
3008 	return;
3009     ++recurse;
3010 
3011     /* lock/unlock the item itself */
3012     if (lock)
3013 	tv->v_lock |= VAR_LOCKED;
3014     else
3015 	tv->v_lock &= ~VAR_LOCKED;
3016 
3017     switch (tv->v_type)
3018     {
3019 	case VAR_UNKNOWN:
3020 	case VAR_NUMBER:
3021 	case VAR_STRING:
3022 	case VAR_FUNC:
3023 	case VAR_PARTIAL:
3024 	case VAR_FLOAT:
3025 	case VAR_SPECIAL:
3026 	case VAR_JOB:
3027 	case VAR_CHANNEL:
3028 	    break;
3029 
3030 	case VAR_LIST:
3031 	    if ((l = tv->vval.v_list) != NULL)
3032 	    {
3033 		if (lock)
3034 		    l->lv_lock |= VAR_LOCKED;
3035 		else
3036 		    l->lv_lock &= ~VAR_LOCKED;
3037 		if (deep < 0 || deep > 1)
3038 		    /* recursive: lock/unlock the items the List contains */
3039 		    for (li = l->lv_first; li != NULL; li = li->li_next)
3040 			item_lock(&li->li_tv, deep - 1, lock);
3041 	    }
3042 	    break;
3043 	case VAR_DICT:
3044 	    if ((d = tv->vval.v_dict) != NULL)
3045 	    {
3046 		if (lock)
3047 		    d->dv_lock |= VAR_LOCKED;
3048 		else
3049 		    d->dv_lock &= ~VAR_LOCKED;
3050 		if (deep < 0 || deep > 1)
3051 		{
3052 		    /* recursive: lock/unlock the items the List contains */
3053 		    todo = (int)d->dv_hashtab.ht_used;
3054 		    for (hi = d->dv_hashtab.ht_array; todo > 0; ++hi)
3055 		    {
3056 			if (!HASHITEM_EMPTY(hi))
3057 			{
3058 			    --todo;
3059 			    item_lock(&HI2DI(hi)->di_tv, deep - 1, lock);
3060 			}
3061 		    }
3062 		}
3063 	    }
3064     }
3065     --recurse;
3066 }
3067 
3068 #if (defined(FEAT_MENU) && defined(FEAT_MULTI_LANG)) || defined(PROTO)
3069 /*
3070  * Delete all "menutrans_" variables.
3071  */
3072     void
3073 del_menutrans_vars(void)
3074 {
3075     hashitem_T	*hi;
3076     int		todo;
3077 
3078     hash_lock(&globvarht);
3079     todo = (int)globvarht.ht_used;
3080     for (hi = globvarht.ht_array; todo > 0 && !got_int; ++hi)
3081     {
3082 	if (!HASHITEM_EMPTY(hi))
3083 	{
3084 	    --todo;
3085 	    if (STRNCMP(HI2DI(hi)->di_key, "menutrans_", 10) == 0)
3086 		delete_var(&globvarht, hi);
3087 	}
3088     }
3089     hash_unlock(&globvarht);
3090 }
3091 #endif
3092 
3093 #if defined(FEAT_CMDL_COMPL) || defined(PROTO)
3094 
3095 /*
3096  * Local string buffer for the next two functions to store a variable name
3097  * with its prefix. Allocated in cat_prefix_varname(), freed later in
3098  * get_user_var_name().
3099  */
3100 
3101 static char_u *cat_prefix_varname(int prefix, char_u *name);
3102 
3103 static char_u	*varnamebuf = NULL;
3104 static int	varnamebuflen = 0;
3105 
3106 /*
3107  * Function to concatenate a prefix and a variable name.
3108  */
3109     static char_u *
3110 cat_prefix_varname(int prefix, char_u *name)
3111 {
3112     int		len;
3113 
3114     len = (int)STRLEN(name) + 3;
3115     if (len > varnamebuflen)
3116     {
3117 	vim_free(varnamebuf);
3118 	len += 10;			/* some additional space */
3119 	varnamebuf = alloc(len);
3120 	if (varnamebuf == NULL)
3121 	{
3122 	    varnamebuflen = 0;
3123 	    return NULL;
3124 	}
3125 	varnamebuflen = len;
3126     }
3127     *varnamebuf = prefix;
3128     varnamebuf[1] = ':';
3129     STRCPY(varnamebuf + 2, name);
3130     return varnamebuf;
3131 }
3132 
3133 /*
3134  * Function given to ExpandGeneric() to obtain the list of user defined
3135  * (global/buffer/window/built-in) variable names.
3136  */
3137     char_u *
3138 get_user_var_name(expand_T *xp, int idx)
3139 {
3140     static long_u	gdone;
3141     static long_u	bdone;
3142     static long_u	wdone;
3143     static long_u	tdone;
3144     static int		vidx;
3145     static hashitem_T	*hi;
3146     hashtab_T		*ht;
3147 
3148     if (idx == 0)
3149     {
3150 	gdone = bdone = wdone = vidx = 0;
3151 	tdone = 0;
3152     }
3153 
3154     /* Global variables */
3155     if (gdone < globvarht.ht_used)
3156     {
3157 	if (gdone++ == 0)
3158 	    hi = globvarht.ht_array;
3159 	else
3160 	    ++hi;
3161 	while (HASHITEM_EMPTY(hi))
3162 	    ++hi;
3163 	if (STRNCMP("g:", xp->xp_pattern, 2) == 0)
3164 	    return cat_prefix_varname('g', hi->hi_key);
3165 	return hi->hi_key;
3166     }
3167 
3168     /* b: variables */
3169     ht = &curbuf->b_vars->dv_hashtab;
3170     if (bdone < ht->ht_used)
3171     {
3172 	if (bdone++ == 0)
3173 	    hi = ht->ht_array;
3174 	else
3175 	    ++hi;
3176 	while (HASHITEM_EMPTY(hi))
3177 	    ++hi;
3178 	return cat_prefix_varname('b', hi->hi_key);
3179     }
3180 
3181     /* w: variables */
3182     ht = &curwin->w_vars->dv_hashtab;
3183     if (wdone < ht->ht_used)
3184     {
3185 	if (wdone++ == 0)
3186 	    hi = ht->ht_array;
3187 	else
3188 	    ++hi;
3189 	while (HASHITEM_EMPTY(hi))
3190 	    ++hi;
3191 	return cat_prefix_varname('w', hi->hi_key);
3192     }
3193 
3194     /* t: variables */
3195     ht = &curtab->tp_vars->dv_hashtab;
3196     if (tdone < ht->ht_used)
3197     {
3198 	if (tdone++ == 0)
3199 	    hi = ht->ht_array;
3200 	else
3201 	    ++hi;
3202 	while (HASHITEM_EMPTY(hi))
3203 	    ++hi;
3204 	return cat_prefix_varname('t', hi->hi_key);
3205     }
3206 
3207     /* v: variables */
3208     if (vidx < VV_LEN)
3209 	return cat_prefix_varname('v', (char_u *)vimvars[vidx++].vv_name);
3210 
3211     vim_free(varnamebuf);
3212     varnamebuf = NULL;
3213     varnamebuflen = 0;
3214     return NULL;
3215 }
3216 
3217 #endif /* FEAT_CMDL_COMPL */
3218 
3219 /*
3220  * Return TRUE if "pat" matches "text".
3221  * Does not use 'cpo' and always uses 'magic'.
3222  */
3223     static int
3224 pattern_match(char_u *pat, char_u *text, int ic)
3225 {
3226     int		matches = FALSE;
3227     char_u	*save_cpo;
3228     regmatch_T	regmatch;
3229 
3230     /* avoid 'l' flag in 'cpoptions' */
3231     save_cpo = p_cpo;
3232     p_cpo = (char_u *)"";
3233     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
3234     if (regmatch.regprog != NULL)
3235     {
3236 	regmatch.rm_ic = ic;
3237 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
3238 	vim_regfree(regmatch.regprog);
3239     }
3240     p_cpo = save_cpo;
3241     return matches;
3242 }
3243 
3244 /*
3245  * types for expressions.
3246  */
3247 typedef enum
3248 {
3249     TYPE_UNKNOWN = 0
3250     , TYPE_EQUAL	/* == */
3251     , TYPE_NEQUAL	/* != */
3252     , TYPE_GREATER	/* >  */
3253     , TYPE_GEQUAL	/* >= */
3254     , TYPE_SMALLER	/* <  */
3255     , TYPE_SEQUAL	/* <= */
3256     , TYPE_MATCH	/* =~ */
3257     , TYPE_NOMATCH	/* !~ */
3258 } exptype_T;
3259 
3260 /*
3261  * The "evaluate" argument: When FALSE, the argument is only parsed but not
3262  * executed.  The function may return OK, but the rettv will be of type
3263  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
3264  */
3265 
3266 /*
3267  * Handle zero level expression.
3268  * This calls eval1() and handles error message and nextcmd.
3269  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
3270  * Note: "rettv.v_lock" is not set.
3271  * Return OK or FAIL.
3272  */
3273     int
3274 eval0(
3275     char_u	*arg,
3276     typval_T	*rettv,
3277     char_u	**nextcmd,
3278     int		evaluate)
3279 {
3280     int		ret;
3281     char_u	*p;
3282 
3283     p = skipwhite(arg);
3284     ret = eval1(&p, rettv, evaluate);
3285     if (ret == FAIL || !ends_excmd(*p))
3286     {
3287 	if (ret != FAIL)
3288 	    clear_tv(rettv);
3289 	/*
3290 	 * Report the invalid expression unless the expression evaluation has
3291 	 * been cancelled due to an aborting error, an interrupt, or an
3292 	 * exception.
3293 	 */
3294 	if (!aborting())
3295 	    EMSG2(_(e_invexpr2), arg);
3296 	ret = FAIL;
3297     }
3298     if (nextcmd != NULL)
3299 	*nextcmd = check_nextcmd(p);
3300 
3301     return ret;
3302 }
3303 
3304 /*
3305  * Handle top level expression:
3306  *	expr2 ? expr1 : expr1
3307  *
3308  * "arg" must point to the first non-white of the expression.
3309  * "arg" is advanced to the next non-white after the recognized expression.
3310  *
3311  * Note: "rettv.v_lock" is not set.
3312  *
3313  * Return OK or FAIL.
3314  */
3315     int
3316 eval1(char_u **arg, typval_T *rettv, int evaluate)
3317 {
3318     int		result;
3319     typval_T	var2;
3320 
3321     /*
3322      * Get the first variable.
3323      */
3324     if (eval2(arg, rettv, evaluate) == FAIL)
3325 	return FAIL;
3326 
3327     if ((*arg)[0] == '?')
3328     {
3329 	result = FALSE;
3330 	if (evaluate)
3331 	{
3332 	    int		error = FALSE;
3333 
3334 	    if (get_tv_number_chk(rettv, &error) != 0)
3335 		result = TRUE;
3336 	    clear_tv(rettv);
3337 	    if (error)
3338 		return FAIL;
3339 	}
3340 
3341 	/*
3342 	 * Get the second variable.
3343 	 */
3344 	*arg = skipwhite(*arg + 1);
3345 	if (eval1(arg, rettv, evaluate && result) == FAIL) /* recursive! */
3346 	    return FAIL;
3347 
3348 	/*
3349 	 * Check for the ":".
3350 	 */
3351 	if ((*arg)[0] != ':')
3352 	{
3353 	    EMSG(_("E109: Missing ':' after '?'"));
3354 	    if (evaluate && result)
3355 		clear_tv(rettv);
3356 	    return FAIL;
3357 	}
3358 
3359 	/*
3360 	 * Get the third variable.
3361 	 */
3362 	*arg = skipwhite(*arg + 1);
3363 	if (eval1(arg, &var2, evaluate && !result) == FAIL) /* recursive! */
3364 	{
3365 	    if (evaluate && result)
3366 		clear_tv(rettv);
3367 	    return FAIL;
3368 	}
3369 	if (evaluate && !result)
3370 	    *rettv = var2;
3371     }
3372 
3373     return OK;
3374 }
3375 
3376 /*
3377  * Handle first level expression:
3378  *	expr2 || expr2 || expr2	    logical OR
3379  *
3380  * "arg" must point to the first non-white of the expression.
3381  * "arg" is advanced to the next non-white after the recognized expression.
3382  *
3383  * Return OK or FAIL.
3384  */
3385     static int
3386 eval2(char_u **arg, typval_T *rettv, int evaluate)
3387 {
3388     typval_T	var2;
3389     long	result;
3390     int		first;
3391     int		error = FALSE;
3392 
3393     /*
3394      * Get the first variable.
3395      */
3396     if (eval3(arg, rettv, evaluate) == FAIL)
3397 	return FAIL;
3398 
3399     /*
3400      * Repeat until there is no following "||".
3401      */
3402     first = TRUE;
3403     result = FALSE;
3404     while ((*arg)[0] == '|' && (*arg)[1] == '|')
3405     {
3406 	if (evaluate && first)
3407 	{
3408 	    if (get_tv_number_chk(rettv, &error) != 0)
3409 		result = TRUE;
3410 	    clear_tv(rettv);
3411 	    if (error)
3412 		return FAIL;
3413 	    first = FALSE;
3414 	}
3415 
3416 	/*
3417 	 * Get the second variable.
3418 	 */
3419 	*arg = skipwhite(*arg + 2);
3420 	if (eval3(arg, &var2, evaluate && !result) == FAIL)
3421 	    return FAIL;
3422 
3423 	/*
3424 	 * Compute the result.
3425 	 */
3426 	if (evaluate && !result)
3427 	{
3428 	    if (get_tv_number_chk(&var2, &error) != 0)
3429 		result = TRUE;
3430 	    clear_tv(&var2);
3431 	    if (error)
3432 		return FAIL;
3433 	}
3434 	if (evaluate)
3435 	{
3436 	    rettv->v_type = VAR_NUMBER;
3437 	    rettv->vval.v_number = result;
3438 	}
3439     }
3440 
3441     return OK;
3442 }
3443 
3444 /*
3445  * Handle second level expression:
3446  *	expr3 && expr3 && expr3	    logical AND
3447  *
3448  * "arg" must point to the first non-white of the expression.
3449  * "arg" is advanced to the next non-white after the recognized expression.
3450  *
3451  * Return OK or FAIL.
3452  */
3453     static int
3454 eval3(char_u **arg, typval_T *rettv, int evaluate)
3455 {
3456     typval_T	var2;
3457     long	result;
3458     int		first;
3459     int		error = FALSE;
3460 
3461     /*
3462      * Get the first variable.
3463      */
3464     if (eval4(arg, rettv, evaluate) == FAIL)
3465 	return FAIL;
3466 
3467     /*
3468      * Repeat until there is no following "&&".
3469      */
3470     first = TRUE;
3471     result = TRUE;
3472     while ((*arg)[0] == '&' && (*arg)[1] == '&')
3473     {
3474 	if (evaluate && first)
3475 	{
3476 	    if (get_tv_number_chk(rettv, &error) == 0)
3477 		result = FALSE;
3478 	    clear_tv(rettv);
3479 	    if (error)
3480 		return FAIL;
3481 	    first = FALSE;
3482 	}
3483 
3484 	/*
3485 	 * Get the second variable.
3486 	 */
3487 	*arg = skipwhite(*arg + 2);
3488 	if (eval4(arg, &var2, evaluate && result) == FAIL)
3489 	    return FAIL;
3490 
3491 	/*
3492 	 * Compute the result.
3493 	 */
3494 	if (evaluate && result)
3495 	{
3496 	    if (get_tv_number_chk(&var2, &error) == 0)
3497 		result = FALSE;
3498 	    clear_tv(&var2);
3499 	    if (error)
3500 		return FAIL;
3501 	}
3502 	if (evaluate)
3503 	{
3504 	    rettv->v_type = VAR_NUMBER;
3505 	    rettv->vval.v_number = result;
3506 	}
3507     }
3508 
3509     return OK;
3510 }
3511 
3512 /*
3513  * Handle third level expression:
3514  *	var1 == var2
3515  *	var1 =~ var2
3516  *	var1 != var2
3517  *	var1 !~ var2
3518  *	var1 > var2
3519  *	var1 >= var2
3520  *	var1 < var2
3521  *	var1 <= var2
3522  *	var1 is var2
3523  *	var1 isnot var2
3524  *
3525  * "arg" must point to the first non-white of the expression.
3526  * "arg" is advanced to the next non-white after the recognized expression.
3527  *
3528  * Return OK or FAIL.
3529  */
3530     static int
3531 eval4(char_u **arg, typval_T *rettv, int evaluate)
3532 {
3533     typval_T	var2;
3534     char_u	*p;
3535     int		i;
3536     exptype_T	type = TYPE_UNKNOWN;
3537     int		type_is = FALSE;    /* TRUE for "is" and "isnot" */
3538     int		len = 2;
3539     varnumber_T	n1, n2;
3540     char_u	*s1, *s2;
3541     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3542     int		ic;
3543 
3544     /*
3545      * Get the first variable.
3546      */
3547     if (eval5(arg, rettv, evaluate) == FAIL)
3548 	return FAIL;
3549 
3550     p = *arg;
3551     switch (p[0])
3552     {
3553 	case '=':   if (p[1] == '=')
3554 			type = TYPE_EQUAL;
3555 		    else if (p[1] == '~')
3556 			type = TYPE_MATCH;
3557 		    break;
3558 	case '!':   if (p[1] == '=')
3559 			type = TYPE_NEQUAL;
3560 		    else if (p[1] == '~')
3561 			type = TYPE_NOMATCH;
3562 		    break;
3563 	case '>':   if (p[1] != '=')
3564 		    {
3565 			type = TYPE_GREATER;
3566 			len = 1;
3567 		    }
3568 		    else
3569 			type = TYPE_GEQUAL;
3570 		    break;
3571 	case '<':   if (p[1] != '=')
3572 		    {
3573 			type = TYPE_SMALLER;
3574 			len = 1;
3575 		    }
3576 		    else
3577 			type = TYPE_SEQUAL;
3578 		    break;
3579 	case 'i':   if (p[1] == 's')
3580 		    {
3581 			if (p[2] == 'n' && p[3] == 'o' && p[4] == 't')
3582 			    len = 5;
3583 			i = p[len];
3584 			if (!isalnum(i) && i != '_')
3585 			{
3586 			    type = len == 2 ? TYPE_EQUAL : TYPE_NEQUAL;
3587 			    type_is = TRUE;
3588 			}
3589 		    }
3590 		    break;
3591     }
3592 
3593     /*
3594      * If there is a comparative operator, use it.
3595      */
3596     if (type != TYPE_UNKNOWN)
3597     {
3598 	/* extra question mark appended: ignore case */
3599 	if (p[len] == '?')
3600 	{
3601 	    ic = TRUE;
3602 	    ++len;
3603 	}
3604 	/* extra '#' appended: match case */
3605 	else if (p[len] == '#')
3606 	{
3607 	    ic = FALSE;
3608 	    ++len;
3609 	}
3610 	/* nothing appended: use 'ignorecase' */
3611 	else
3612 	    ic = p_ic;
3613 
3614 	/*
3615 	 * Get the second variable.
3616 	 */
3617 	*arg = skipwhite(p + len);
3618 	if (eval5(arg, &var2, evaluate) == FAIL)
3619 	{
3620 	    clear_tv(rettv);
3621 	    return FAIL;
3622 	}
3623 
3624 	if (evaluate)
3625 	{
3626 	    if (type_is && rettv->v_type != var2.v_type)
3627 	    {
3628 		/* For "is" a different type always means FALSE, for "notis"
3629 		 * it means TRUE. */
3630 		n1 = (type == TYPE_NEQUAL);
3631 	    }
3632 	    else if (rettv->v_type == VAR_LIST || var2.v_type == VAR_LIST)
3633 	    {
3634 		if (type_is)
3635 		{
3636 		    n1 = (rettv->v_type == var2.v_type
3637 				   && rettv->vval.v_list == var2.vval.v_list);
3638 		    if (type == TYPE_NEQUAL)
3639 			n1 = !n1;
3640 		}
3641 		else if (rettv->v_type != var2.v_type
3642 			|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
3643 		{
3644 		    if (rettv->v_type != var2.v_type)
3645 			EMSG(_("E691: Can only compare List with List"));
3646 		    else
3647 			EMSG(_("E692: Invalid operation for List"));
3648 		    clear_tv(rettv);
3649 		    clear_tv(&var2);
3650 		    return FAIL;
3651 		}
3652 		else
3653 		{
3654 		    /* Compare two Lists for being equal or unequal. */
3655 		    n1 = list_equal(rettv->vval.v_list, var2.vval.v_list,
3656 								   ic, FALSE);
3657 		    if (type == TYPE_NEQUAL)
3658 			n1 = !n1;
3659 		}
3660 	    }
3661 
3662 	    else if (rettv->v_type == VAR_DICT || var2.v_type == VAR_DICT)
3663 	    {
3664 		if (type_is)
3665 		{
3666 		    n1 = (rettv->v_type == var2.v_type
3667 				   && rettv->vval.v_dict == var2.vval.v_dict);
3668 		    if (type == TYPE_NEQUAL)
3669 			n1 = !n1;
3670 		}
3671 		else if (rettv->v_type != var2.v_type
3672 			|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
3673 		{
3674 		    if (rettv->v_type != var2.v_type)
3675 			EMSG(_("E735: Can only compare Dictionary with Dictionary"));
3676 		    else
3677 			EMSG(_("E736: Invalid operation for Dictionary"));
3678 		    clear_tv(rettv);
3679 		    clear_tv(&var2);
3680 		    return FAIL;
3681 		}
3682 		else
3683 		{
3684 		    /* Compare two Dictionaries for being equal or unequal. */
3685 		    n1 = dict_equal(rettv->vval.v_dict, var2.vval.v_dict,
3686 								   ic, FALSE);
3687 		    if (type == TYPE_NEQUAL)
3688 			n1 = !n1;
3689 		}
3690 	    }
3691 
3692 	    else if (rettv->v_type == VAR_FUNC || var2.v_type == VAR_FUNC
3693 		|| rettv->v_type == VAR_PARTIAL || var2.v_type == VAR_PARTIAL)
3694 	    {
3695 		if (type != TYPE_EQUAL && type != TYPE_NEQUAL)
3696 		{
3697 		    EMSG(_("E694: Invalid operation for Funcrefs"));
3698 		    clear_tv(rettv);
3699 		    clear_tv(&var2);
3700 		    return FAIL;
3701 		}
3702 		if ((rettv->v_type == VAR_PARTIAL
3703 					     && rettv->vval.v_partial == NULL)
3704 			|| (var2.v_type == VAR_PARTIAL
3705 					      && var2.vval.v_partial == NULL))
3706 		    /* when a partial is NULL assume not equal */
3707 		    n1 = FALSE;
3708 		else if (type_is)
3709 		{
3710 		    if (rettv->v_type == VAR_FUNC && var2.v_type == VAR_FUNC)
3711 			/* strings are considered the same if their value is
3712 			 * the same */
3713 			n1 = tv_equal(rettv, &var2, ic, FALSE);
3714 		    else if (rettv->v_type == VAR_PARTIAL
3715 						&& var2.v_type == VAR_PARTIAL)
3716 			n1 = (rettv->vval.v_partial == var2.vval.v_partial);
3717 		    else
3718 			n1 = FALSE;
3719 		}
3720 		else
3721 		    n1 = tv_equal(rettv, &var2, ic, FALSE);
3722 		if (type == TYPE_NEQUAL)
3723 		    n1 = !n1;
3724 	    }
3725 
3726 #ifdef FEAT_FLOAT
3727 	    /*
3728 	     * If one of the two variables is a float, compare as a float.
3729 	     * When using "=~" or "!~", always compare as string.
3730 	     */
3731 	    else if ((rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3732 		    && type != TYPE_MATCH && type != TYPE_NOMATCH)
3733 	    {
3734 		float_T f1, f2;
3735 
3736 		if (rettv->v_type == VAR_FLOAT)
3737 		    f1 = rettv->vval.v_float;
3738 		else
3739 		    f1 = get_tv_number(rettv);
3740 		if (var2.v_type == VAR_FLOAT)
3741 		    f2 = var2.vval.v_float;
3742 		else
3743 		    f2 = get_tv_number(&var2);
3744 		n1 = FALSE;
3745 		switch (type)
3746 		{
3747 		    case TYPE_EQUAL:    n1 = (f1 == f2); break;
3748 		    case TYPE_NEQUAL:   n1 = (f1 != f2); break;
3749 		    case TYPE_GREATER:  n1 = (f1 > f2); break;
3750 		    case TYPE_GEQUAL:   n1 = (f1 >= f2); break;
3751 		    case TYPE_SMALLER:  n1 = (f1 < f2); break;
3752 		    case TYPE_SEQUAL:   n1 = (f1 <= f2); break;
3753 		    case TYPE_UNKNOWN:
3754 		    case TYPE_MATCH:
3755 		    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
3756 		}
3757 	    }
3758 #endif
3759 
3760 	    /*
3761 	     * If one of the two variables is a number, compare as a number.
3762 	     * When using "=~" or "!~", always compare as string.
3763 	     */
3764 	    else if ((rettv->v_type == VAR_NUMBER || var2.v_type == VAR_NUMBER)
3765 		    && type != TYPE_MATCH && type != TYPE_NOMATCH)
3766 	    {
3767 		n1 = get_tv_number(rettv);
3768 		n2 = get_tv_number(&var2);
3769 		switch (type)
3770 		{
3771 		    case TYPE_EQUAL:    n1 = (n1 == n2); break;
3772 		    case TYPE_NEQUAL:   n1 = (n1 != n2); break;
3773 		    case TYPE_GREATER:  n1 = (n1 > n2); break;
3774 		    case TYPE_GEQUAL:   n1 = (n1 >= n2); break;
3775 		    case TYPE_SMALLER:  n1 = (n1 < n2); break;
3776 		    case TYPE_SEQUAL:   n1 = (n1 <= n2); break;
3777 		    case TYPE_UNKNOWN:
3778 		    case TYPE_MATCH:
3779 		    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
3780 		}
3781 	    }
3782 	    else
3783 	    {
3784 		s1 = get_tv_string_buf(rettv, buf1);
3785 		s2 = get_tv_string_buf(&var2, buf2);
3786 		if (type != TYPE_MATCH && type != TYPE_NOMATCH)
3787 		    i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
3788 		else
3789 		    i = 0;
3790 		n1 = FALSE;
3791 		switch (type)
3792 		{
3793 		    case TYPE_EQUAL:    n1 = (i == 0); break;
3794 		    case TYPE_NEQUAL:   n1 = (i != 0); break;
3795 		    case TYPE_GREATER:  n1 = (i > 0); break;
3796 		    case TYPE_GEQUAL:   n1 = (i >= 0); break;
3797 		    case TYPE_SMALLER:  n1 = (i < 0); break;
3798 		    case TYPE_SEQUAL:   n1 = (i <= 0); break;
3799 
3800 		    case TYPE_MATCH:
3801 		    case TYPE_NOMATCH:
3802 			    n1 = pattern_match(s2, s1, ic);
3803 			    if (type == TYPE_NOMATCH)
3804 				n1 = !n1;
3805 			    break;
3806 
3807 		    case TYPE_UNKNOWN:  break;  /* avoid gcc warning */
3808 		}
3809 	    }
3810 	    clear_tv(rettv);
3811 	    clear_tv(&var2);
3812 	    rettv->v_type = VAR_NUMBER;
3813 	    rettv->vval.v_number = n1;
3814 	}
3815     }
3816 
3817     return OK;
3818 }
3819 
3820 /*
3821  * Handle fourth level expression:
3822  *	+	number addition
3823  *	-	number subtraction
3824  *	.	string concatenation
3825  *
3826  * "arg" must point to the first non-white of the expression.
3827  * "arg" is advanced to the next non-white after the recognized expression.
3828  *
3829  * Return OK or FAIL.
3830  */
3831     static int
3832 eval5(char_u **arg, typval_T *rettv, int evaluate)
3833 {
3834     typval_T	var2;
3835     typval_T	var3;
3836     int		op;
3837     varnumber_T	n1, n2;
3838 #ifdef FEAT_FLOAT
3839     float_T	f1 = 0, f2 = 0;
3840 #endif
3841     char_u	*s1, *s2;
3842     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3843     char_u	*p;
3844 
3845     /*
3846      * Get the first variable.
3847      */
3848     if (eval6(arg, rettv, evaluate, FALSE) == FAIL)
3849 	return FAIL;
3850 
3851     /*
3852      * Repeat computing, until no '+', '-' or '.' is following.
3853      */
3854     for (;;)
3855     {
3856 	op = **arg;
3857 	if (op != '+' && op != '-' && op != '.')
3858 	    break;
3859 
3860 	if ((op != '+' || rettv->v_type != VAR_LIST)
3861 #ifdef FEAT_FLOAT
3862 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
3863 #endif
3864 		)
3865 	{
3866 	    /* For "list + ...", an illegal use of the first operand as
3867 	     * a number cannot be determined before evaluating the 2nd
3868 	     * operand: if this is also a list, all is ok.
3869 	     * For "something . ...", "something - ..." or "non-list + ...",
3870 	     * we know that the first operand needs to be a string or number
3871 	     * without evaluating the 2nd operand.  So check before to avoid
3872 	     * side effects after an error. */
3873 	    if (evaluate && get_tv_string_chk(rettv) == NULL)
3874 	    {
3875 		clear_tv(rettv);
3876 		return FAIL;
3877 	    }
3878 	}
3879 
3880 	/*
3881 	 * Get the second variable.
3882 	 */
3883 	*arg = skipwhite(*arg + 1);
3884 	if (eval6(arg, &var2, evaluate, op == '.') == FAIL)
3885 	{
3886 	    clear_tv(rettv);
3887 	    return FAIL;
3888 	}
3889 
3890 	if (evaluate)
3891 	{
3892 	    /*
3893 	     * Compute the result.
3894 	     */
3895 	    if (op == '.')
3896 	    {
3897 		s1 = get_tv_string_buf(rettv, buf1);	/* already checked */
3898 		s2 = get_tv_string_buf_chk(&var2, buf2);
3899 		if (s2 == NULL)		/* type error ? */
3900 		{
3901 		    clear_tv(rettv);
3902 		    clear_tv(&var2);
3903 		    return FAIL;
3904 		}
3905 		p = concat_str(s1, s2);
3906 		clear_tv(rettv);
3907 		rettv->v_type = VAR_STRING;
3908 		rettv->vval.v_string = p;
3909 	    }
3910 	    else if (op == '+' && rettv->v_type == VAR_LIST
3911 						   && var2.v_type == VAR_LIST)
3912 	    {
3913 		/* concatenate Lists */
3914 		if (list_concat(rettv->vval.v_list, var2.vval.v_list,
3915 							       &var3) == FAIL)
3916 		{
3917 		    clear_tv(rettv);
3918 		    clear_tv(&var2);
3919 		    return FAIL;
3920 		}
3921 		clear_tv(rettv);
3922 		*rettv = var3;
3923 	    }
3924 	    else
3925 	    {
3926 		int	    error = FALSE;
3927 
3928 #ifdef FEAT_FLOAT
3929 		if (rettv->v_type == VAR_FLOAT)
3930 		{
3931 		    f1 = rettv->vval.v_float;
3932 		    n1 = 0;
3933 		}
3934 		else
3935 #endif
3936 		{
3937 		    n1 = get_tv_number_chk(rettv, &error);
3938 		    if (error)
3939 		    {
3940 			/* This can only happen for "list + non-list".  For
3941 			 * "non-list + ..." or "something - ...", we returned
3942 			 * before evaluating the 2nd operand. */
3943 			clear_tv(rettv);
3944 			return FAIL;
3945 		    }
3946 #ifdef FEAT_FLOAT
3947 		    if (var2.v_type == VAR_FLOAT)
3948 			f1 = n1;
3949 #endif
3950 		}
3951 #ifdef FEAT_FLOAT
3952 		if (var2.v_type == VAR_FLOAT)
3953 		{
3954 		    f2 = var2.vval.v_float;
3955 		    n2 = 0;
3956 		}
3957 		else
3958 #endif
3959 		{
3960 		    n2 = get_tv_number_chk(&var2, &error);
3961 		    if (error)
3962 		    {
3963 			clear_tv(rettv);
3964 			clear_tv(&var2);
3965 			return FAIL;
3966 		    }
3967 #ifdef FEAT_FLOAT
3968 		    if (rettv->v_type == VAR_FLOAT)
3969 			f2 = n2;
3970 #endif
3971 		}
3972 		clear_tv(rettv);
3973 
3974 #ifdef FEAT_FLOAT
3975 		/* If there is a float on either side the result is a float. */
3976 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3977 		{
3978 		    if (op == '+')
3979 			f1 = f1 + f2;
3980 		    else
3981 			f1 = f1 - f2;
3982 		    rettv->v_type = VAR_FLOAT;
3983 		    rettv->vval.v_float = f1;
3984 		}
3985 		else
3986 #endif
3987 		{
3988 		    if (op == '+')
3989 			n1 = n1 + n2;
3990 		    else
3991 			n1 = n1 - n2;
3992 		    rettv->v_type = VAR_NUMBER;
3993 		    rettv->vval.v_number = n1;
3994 		}
3995 	    }
3996 	    clear_tv(&var2);
3997 	}
3998     }
3999     return OK;
4000 }
4001 
4002 /*
4003  * Handle fifth level expression:
4004  *	*	number multiplication
4005  *	/	number division
4006  *	%	number modulo
4007  *
4008  * "arg" must point to the first non-white of the expression.
4009  * "arg" is advanced to the next non-white after the recognized expression.
4010  *
4011  * Return OK or FAIL.
4012  */
4013     static int
4014 eval6(
4015     char_u	**arg,
4016     typval_T	*rettv,
4017     int		evaluate,
4018     int		want_string)  /* after "." operator */
4019 {
4020     typval_T	var2;
4021     int		op;
4022     varnumber_T	n1, n2;
4023 #ifdef FEAT_FLOAT
4024     int		use_float = FALSE;
4025     float_T	f1 = 0, f2;
4026 #endif
4027     int		error = FALSE;
4028 
4029     /*
4030      * Get the first variable.
4031      */
4032     if (eval7(arg, rettv, evaluate, want_string) == FAIL)
4033 	return FAIL;
4034 
4035     /*
4036      * Repeat computing, until no '*', '/' or '%' is following.
4037      */
4038     for (;;)
4039     {
4040 	op = **arg;
4041 	if (op != '*' && op != '/' && op != '%')
4042 	    break;
4043 
4044 	if (evaluate)
4045 	{
4046 #ifdef FEAT_FLOAT
4047 	    if (rettv->v_type == VAR_FLOAT)
4048 	    {
4049 		f1 = rettv->vval.v_float;
4050 		use_float = TRUE;
4051 		n1 = 0;
4052 	    }
4053 	    else
4054 #endif
4055 		n1 = get_tv_number_chk(rettv, &error);
4056 	    clear_tv(rettv);
4057 	    if (error)
4058 		return FAIL;
4059 	}
4060 	else
4061 	    n1 = 0;
4062 
4063 	/*
4064 	 * Get the second variable.
4065 	 */
4066 	*arg = skipwhite(*arg + 1);
4067 	if (eval7(arg, &var2, evaluate, FALSE) == FAIL)
4068 	    return FAIL;
4069 
4070 	if (evaluate)
4071 	{
4072 #ifdef FEAT_FLOAT
4073 	    if (var2.v_type == VAR_FLOAT)
4074 	    {
4075 		if (!use_float)
4076 		{
4077 		    f1 = n1;
4078 		    use_float = TRUE;
4079 		}
4080 		f2 = var2.vval.v_float;
4081 		n2 = 0;
4082 	    }
4083 	    else
4084 #endif
4085 	    {
4086 		n2 = get_tv_number_chk(&var2, &error);
4087 		clear_tv(&var2);
4088 		if (error)
4089 		    return FAIL;
4090 #ifdef FEAT_FLOAT
4091 		if (use_float)
4092 		    f2 = n2;
4093 #endif
4094 	    }
4095 
4096 	    /*
4097 	     * Compute the result.
4098 	     * When either side is a float the result is a float.
4099 	     */
4100 #ifdef FEAT_FLOAT
4101 	    if (use_float)
4102 	    {
4103 		if (op == '*')
4104 		    f1 = f1 * f2;
4105 		else if (op == '/')
4106 		{
4107 # ifdef VMS
4108 		    /* VMS crashes on divide by zero, work around it */
4109 		    if (f2 == 0.0)
4110 		    {
4111 			if (f1 == 0)
4112 			    f1 = -1 * __F_FLT_MAX - 1L;   /* similar to NaN */
4113 			else if (f1 < 0)
4114 			    f1 = -1 * __F_FLT_MAX;
4115 			else
4116 			    f1 = __F_FLT_MAX;
4117 		    }
4118 		    else
4119 			f1 = f1 / f2;
4120 # else
4121 		    /* We rely on the floating point library to handle divide
4122 		     * by zero to result in "inf" and not a crash. */
4123 		    f1 = f1 / f2;
4124 # endif
4125 		}
4126 		else
4127 		{
4128 		    EMSG(_("E804: Cannot use '%' with Float"));
4129 		    return FAIL;
4130 		}
4131 		rettv->v_type = VAR_FLOAT;
4132 		rettv->vval.v_float = f1;
4133 	    }
4134 	    else
4135 #endif
4136 	    {
4137 		if (op == '*')
4138 		    n1 = n1 * n2;
4139 		else if (op == '/')
4140 		{
4141 		    if (n2 == 0)	/* give an error message? */
4142 		    {
4143 			if (n1 == 0)
4144 			    n1 = VARNUM_MIN; /* similar to NaN */
4145 			else if (n1 < 0)
4146 			    n1 = -VARNUM_MAX;
4147 			else
4148 			    n1 = VARNUM_MAX;
4149 		    }
4150 		    else
4151 			n1 = n1 / n2;
4152 		}
4153 		else
4154 		{
4155 		    if (n2 == 0)	/* give an error message? */
4156 			n1 = 0;
4157 		    else
4158 			n1 = n1 % n2;
4159 		}
4160 		rettv->v_type = VAR_NUMBER;
4161 		rettv->vval.v_number = n1;
4162 	    }
4163 	}
4164     }
4165 
4166     return OK;
4167 }
4168 
4169 /*
4170  * Handle sixth level expression:
4171  *  number		number constant
4172  *  "string"		string constant
4173  *  'string'		literal string constant
4174  *  &option-name	option value
4175  *  @r			register contents
4176  *  identifier		variable value
4177  *  function()		function call
4178  *  $VAR		environment variable
4179  *  (expression)	nested expression
4180  *  [expr, expr]	List
4181  *  {key: val, key: val}  Dictionary
4182  *
4183  *  Also handle:
4184  *  ! in front		logical NOT
4185  *  - in front		unary minus
4186  *  + in front		unary plus (ignored)
4187  *  trailing []		subscript in String or List
4188  *  trailing .name	entry in Dictionary
4189  *
4190  * "arg" must point to the first non-white of the expression.
4191  * "arg" is advanced to the next non-white after the recognized expression.
4192  *
4193  * Return OK or FAIL.
4194  */
4195     static int
4196 eval7(
4197     char_u	**arg,
4198     typval_T	*rettv,
4199     int		evaluate,
4200     int		want_string UNUSED)	/* after "." operator */
4201 {
4202     varnumber_T	n;
4203     int		len;
4204     char_u	*s;
4205     char_u	*start_leader, *end_leader;
4206     int		ret = OK;
4207     char_u	*alias;
4208 
4209     /*
4210      * Initialise variable so that clear_tv() can't mistake this for a
4211      * string and free a string that isn't there.
4212      */
4213     rettv->v_type = VAR_UNKNOWN;
4214 
4215     /*
4216      * Skip '!', '-' and '+' characters.  They are handled later.
4217      */
4218     start_leader = *arg;
4219     while (**arg == '!' || **arg == '-' || **arg == '+')
4220 	*arg = skipwhite(*arg + 1);
4221     end_leader = *arg;
4222 
4223     switch (**arg)
4224     {
4225     /*
4226      * Number constant.
4227      */
4228     case '0':
4229     case '1':
4230     case '2':
4231     case '3':
4232     case '4':
4233     case '5':
4234     case '6':
4235     case '7':
4236     case '8':
4237     case '9':
4238 	{
4239 #ifdef FEAT_FLOAT
4240 		char_u *p = skipdigits(*arg + 1);
4241 		int    get_float = FALSE;
4242 
4243 		/* We accept a float when the format matches
4244 		 * "[0-9]\+\.[0-9]\+\([eE][+-]\?[0-9]\+\)\?".  This is very
4245 		 * strict to avoid backwards compatibility problems.
4246 		 * Don't look for a float after the "." operator, so that
4247 		 * ":let vers = 1.2.3" doesn't fail. */
4248 		if (!want_string && p[0] == '.' && vim_isdigit(p[1]))
4249 		{
4250 		    get_float = TRUE;
4251 		    p = skipdigits(p + 2);
4252 		    if (*p == 'e' || *p == 'E')
4253 		    {
4254 			++p;
4255 			if (*p == '-' || *p == '+')
4256 			    ++p;
4257 			if (!vim_isdigit(*p))
4258 			    get_float = FALSE;
4259 			else
4260 			    p = skipdigits(p + 1);
4261 		    }
4262 		    if (ASCII_ISALPHA(*p) || *p == '.')
4263 			get_float = FALSE;
4264 		}
4265 		if (get_float)
4266 		{
4267 		    float_T	f;
4268 
4269 		    *arg += string2float(*arg, &f);
4270 		    if (evaluate)
4271 		    {
4272 			rettv->v_type = VAR_FLOAT;
4273 			rettv->vval.v_float = f;
4274 		    }
4275 		}
4276 		else
4277 #endif
4278 		{
4279 		    vim_str2nr(*arg, NULL, &len, STR2NR_ALL, &n, NULL, 0);
4280 		    *arg += len;
4281 		    if (evaluate)
4282 		    {
4283 			rettv->v_type = VAR_NUMBER;
4284 			rettv->vval.v_number = n;
4285 		    }
4286 		}
4287 		break;
4288 	}
4289 
4290     /*
4291      * String constant: "string".
4292      */
4293     case '"':	ret = get_string_tv(arg, rettv, evaluate);
4294 		break;
4295 
4296     /*
4297      * Literal string constant: 'str''ing'.
4298      */
4299     case '\'':	ret = get_lit_string_tv(arg, rettv, evaluate);
4300 		break;
4301 
4302     /*
4303      * List: [expr, expr]
4304      */
4305     case '[':	ret = get_list_tv(arg, rettv, evaluate);
4306 		break;
4307 
4308     /*
4309      * Lambda: {arg, arg -> expr}
4310      * Dictionary: {key: val, key: val}
4311      */
4312     case '{':	ret = get_lambda_tv(arg, rettv, evaluate);
4313 		if (ret == NOTDONE)
4314 		    ret = get_dict_tv(arg, rettv, evaluate);
4315 		break;
4316 
4317     /*
4318      * Option value: &name
4319      */
4320     case '&':	ret = get_option_tv(arg, rettv, evaluate);
4321 		break;
4322 
4323     /*
4324      * Environment variable: $VAR.
4325      */
4326     case '$':	ret = get_env_tv(arg, rettv, evaluate);
4327 		break;
4328 
4329     /*
4330      * Register contents: @r.
4331      */
4332     case '@':	++*arg;
4333 		if (evaluate)
4334 		{
4335 		    rettv->v_type = VAR_STRING;
4336 		    rettv->vval.v_string = get_reg_contents(**arg,
4337 							    GREG_EXPR_SRC);
4338 		}
4339 		if (**arg != NUL)
4340 		    ++*arg;
4341 		break;
4342 
4343     /*
4344      * nested expression: (expression).
4345      */
4346     case '(':	*arg = skipwhite(*arg + 1);
4347 		ret = eval1(arg, rettv, evaluate);	/* recursive! */
4348 		if (**arg == ')')
4349 		    ++*arg;
4350 		else if (ret == OK)
4351 		{
4352 		    EMSG(_("E110: Missing ')'"));
4353 		    clear_tv(rettv);
4354 		    ret = FAIL;
4355 		}
4356 		break;
4357 
4358     default:	ret = NOTDONE;
4359 		break;
4360     }
4361 
4362     if (ret == NOTDONE)
4363     {
4364 	/*
4365 	 * Must be a variable or function name.
4366 	 * Can also be a curly-braces kind of name: {expr}.
4367 	 */
4368 	s = *arg;
4369 	len = get_name_len(arg, &alias, evaluate, TRUE);
4370 	if (alias != NULL)
4371 	    s = alias;
4372 
4373 	if (len <= 0)
4374 	    ret = FAIL;
4375 	else
4376 	{
4377 	    if (**arg == '(')		/* recursive! */
4378 	    {
4379 		partial_T *partial;
4380 
4381 		if (!evaluate)
4382 		    check_vars(s, len);
4383 
4384 		/* If "s" is the name of a variable of type VAR_FUNC
4385 		 * use its contents. */
4386 		s = deref_func_name(s, &len, &partial, !evaluate);
4387 
4388 		/* Need to make a copy, in case evaluating the arguments makes
4389 		 * the name invalid. */
4390 		s = vim_strsave(s);
4391 		if (s == NULL)
4392 		    ret = FAIL;
4393 		else
4394 		    /* Invoke the function. */
4395 		    ret = get_func_tv(s, len, rettv, arg,
4396 			      curwin->w_cursor.lnum, curwin->w_cursor.lnum,
4397 			      &len, evaluate, partial, NULL);
4398 		vim_free(s);
4399 
4400 		/* If evaluate is FALSE rettv->v_type was not set in
4401 		 * get_func_tv, but it's needed in handle_subscript() to parse
4402 		 * what follows. So set it here. */
4403 		if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
4404 		{
4405 		    rettv->vval.v_string = NULL;
4406 		    rettv->v_type = VAR_FUNC;
4407 		}
4408 
4409 		/* Stop the expression evaluation when immediately
4410 		 * aborting on error, or when an interrupt occurred or
4411 		 * an exception was thrown but not caught. */
4412 		if (aborting())
4413 		{
4414 		    if (ret == OK)
4415 			clear_tv(rettv);
4416 		    ret = FAIL;
4417 		}
4418 	    }
4419 	    else if (evaluate)
4420 		ret = get_var_tv(s, len, rettv, NULL, TRUE, FALSE);
4421 	    else
4422 	    {
4423 		check_vars(s, len);
4424 		ret = OK;
4425 	    }
4426 	}
4427 	vim_free(alias);
4428     }
4429 
4430     *arg = skipwhite(*arg);
4431 
4432     /* Handle following '[', '(' and '.' for expr[expr], expr.name,
4433      * expr(expr). */
4434     if (ret == OK)
4435 	ret = handle_subscript(arg, rettv, evaluate, TRUE);
4436 
4437     /*
4438      * Apply logical NOT and unary '-', from right to left, ignore '+'.
4439      */
4440     if (ret == OK && evaluate && end_leader > start_leader)
4441     {
4442 	int	    error = FALSE;
4443 	varnumber_T val = 0;
4444 #ifdef FEAT_FLOAT
4445 	float_T	    f = 0.0;
4446 
4447 	if (rettv->v_type == VAR_FLOAT)
4448 	    f = rettv->vval.v_float;
4449 	else
4450 #endif
4451 	    val = get_tv_number_chk(rettv, &error);
4452 	if (error)
4453 	{
4454 	    clear_tv(rettv);
4455 	    ret = FAIL;
4456 	}
4457 	else
4458 	{
4459 	    while (end_leader > start_leader)
4460 	    {
4461 		--end_leader;
4462 		if (*end_leader == '!')
4463 		{
4464 #ifdef FEAT_FLOAT
4465 		    if (rettv->v_type == VAR_FLOAT)
4466 			f = !f;
4467 		    else
4468 #endif
4469 			val = !val;
4470 		}
4471 		else if (*end_leader == '-')
4472 		{
4473 #ifdef FEAT_FLOAT
4474 		    if (rettv->v_type == VAR_FLOAT)
4475 			f = -f;
4476 		    else
4477 #endif
4478 			val = -val;
4479 		}
4480 	    }
4481 #ifdef FEAT_FLOAT
4482 	    if (rettv->v_type == VAR_FLOAT)
4483 	    {
4484 		clear_tv(rettv);
4485 		rettv->vval.v_float = f;
4486 	    }
4487 	    else
4488 #endif
4489 	    {
4490 		clear_tv(rettv);
4491 		rettv->v_type = VAR_NUMBER;
4492 		rettv->vval.v_number = val;
4493 	    }
4494 	}
4495     }
4496 
4497     return ret;
4498 }
4499 
4500 /*
4501  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
4502  * "*arg" points to the '[' or '.'.
4503  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
4504  */
4505     static int
4506 eval_index(
4507     char_u	**arg,
4508     typval_T	*rettv,
4509     int		evaluate,
4510     int		verbose)	/* give error messages */
4511 {
4512     int		empty1 = FALSE, empty2 = FALSE;
4513     typval_T	var1, var2;
4514     long	n1, n2 = 0;
4515     long	len = -1;
4516     int		range = FALSE;
4517     char_u	*s;
4518     char_u	*key = NULL;
4519 
4520     switch (rettv->v_type)
4521     {
4522 	case VAR_FUNC:
4523 	case VAR_PARTIAL:
4524 	    if (verbose)
4525 		EMSG(_("E695: Cannot index a Funcref"));
4526 	    return FAIL;
4527 	case VAR_FLOAT:
4528 #ifdef FEAT_FLOAT
4529 	    if (verbose)
4530 		EMSG(_(e_float_as_string));
4531 	    return FAIL;
4532 #endif
4533 	case VAR_SPECIAL:
4534 	case VAR_JOB:
4535 	case VAR_CHANNEL:
4536 	    if (verbose)
4537 		EMSG(_("E909: Cannot index a special variable"));
4538 	    return FAIL;
4539 	case VAR_UNKNOWN:
4540 	    if (evaluate)
4541 		return FAIL;
4542 	    /* FALLTHROUGH */
4543 
4544 	case VAR_STRING:
4545 	case VAR_NUMBER:
4546 	case VAR_LIST:
4547 	case VAR_DICT:
4548 	    break;
4549     }
4550 
4551     init_tv(&var1);
4552     init_tv(&var2);
4553     if (**arg == '.')
4554     {
4555 	/*
4556 	 * dict.name
4557 	 */
4558 	key = *arg + 1;
4559 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
4560 	    ;
4561 	if (len == 0)
4562 	    return FAIL;
4563 	*arg = skipwhite(key + len);
4564     }
4565     else
4566     {
4567 	/*
4568 	 * something[idx]
4569 	 *
4570 	 * Get the (first) variable from inside the [].
4571 	 */
4572 	*arg = skipwhite(*arg + 1);
4573 	if (**arg == ':')
4574 	    empty1 = TRUE;
4575 	else if (eval1(arg, &var1, evaluate) == FAIL)	/* recursive! */
4576 	    return FAIL;
4577 	else if (evaluate && get_tv_string_chk(&var1) == NULL)
4578 	{
4579 	    /* not a number or string */
4580 	    clear_tv(&var1);
4581 	    return FAIL;
4582 	}
4583 
4584 	/*
4585 	 * Get the second variable from inside the [:].
4586 	 */
4587 	if (**arg == ':')
4588 	{
4589 	    range = TRUE;
4590 	    *arg = skipwhite(*arg + 1);
4591 	    if (**arg == ']')
4592 		empty2 = TRUE;
4593 	    else if (eval1(arg, &var2, evaluate) == FAIL)	/* recursive! */
4594 	    {
4595 		if (!empty1)
4596 		    clear_tv(&var1);
4597 		return FAIL;
4598 	    }
4599 	    else if (evaluate && get_tv_string_chk(&var2) == NULL)
4600 	    {
4601 		/* not a number or string */
4602 		if (!empty1)
4603 		    clear_tv(&var1);
4604 		clear_tv(&var2);
4605 		return FAIL;
4606 	    }
4607 	}
4608 
4609 	/* Check for the ']'. */
4610 	if (**arg != ']')
4611 	{
4612 	    if (verbose)
4613 		EMSG(_(e_missbrac));
4614 	    clear_tv(&var1);
4615 	    if (range)
4616 		clear_tv(&var2);
4617 	    return FAIL;
4618 	}
4619 	*arg = skipwhite(*arg + 1);	/* skip the ']' */
4620     }
4621 
4622     if (evaluate)
4623     {
4624 	n1 = 0;
4625 	if (!empty1 && rettv->v_type != VAR_DICT)
4626 	{
4627 	    n1 = get_tv_number(&var1);
4628 	    clear_tv(&var1);
4629 	}
4630 	if (range)
4631 	{
4632 	    if (empty2)
4633 		n2 = -1;
4634 	    else
4635 	    {
4636 		n2 = get_tv_number(&var2);
4637 		clear_tv(&var2);
4638 	    }
4639 	}
4640 
4641 	switch (rettv->v_type)
4642 	{
4643 	    case VAR_UNKNOWN:
4644 	    case VAR_FUNC:
4645 	    case VAR_PARTIAL:
4646 	    case VAR_FLOAT:
4647 	    case VAR_SPECIAL:
4648 	    case VAR_JOB:
4649 	    case VAR_CHANNEL:
4650 		break; /* not evaluating, skipping over subscript */
4651 
4652 	    case VAR_NUMBER:
4653 	    case VAR_STRING:
4654 		s = get_tv_string(rettv);
4655 		len = (long)STRLEN(s);
4656 		if (range)
4657 		{
4658 		    /* The resulting variable is a substring.  If the indexes
4659 		     * are out of range the result is empty. */
4660 		    if (n1 < 0)
4661 		    {
4662 			n1 = len + n1;
4663 			if (n1 < 0)
4664 			    n1 = 0;
4665 		    }
4666 		    if (n2 < 0)
4667 			n2 = len + n2;
4668 		    else if (n2 >= len)
4669 			n2 = len;
4670 		    if (n1 >= len || n2 < 0 || n1 > n2)
4671 			s = NULL;
4672 		    else
4673 			s = vim_strnsave(s + n1, (int)(n2 - n1 + 1));
4674 		}
4675 		else
4676 		{
4677 		    /* The resulting variable is a string of a single
4678 		     * character.  If the index is too big or negative the
4679 		     * result is empty. */
4680 		    if (n1 >= len || n1 < 0)
4681 			s = NULL;
4682 		    else
4683 			s = vim_strnsave(s + n1, 1);
4684 		}
4685 		clear_tv(rettv);
4686 		rettv->v_type = VAR_STRING;
4687 		rettv->vval.v_string = s;
4688 		break;
4689 
4690 	    case VAR_LIST:
4691 		len = list_len(rettv->vval.v_list);
4692 		if (n1 < 0)
4693 		    n1 = len + n1;
4694 		if (!empty1 && (n1 < 0 || n1 >= len))
4695 		{
4696 		    /* For a range we allow invalid values and return an empty
4697 		     * list.  A list index out of range is an error. */
4698 		    if (!range)
4699 		    {
4700 			if (verbose)
4701 			    EMSGN(_(e_listidx), n1);
4702 			return FAIL;
4703 		    }
4704 		    n1 = len;
4705 		}
4706 		if (range)
4707 		{
4708 		    list_T	*l;
4709 		    listitem_T	*item;
4710 
4711 		    if (n2 < 0)
4712 			n2 = len + n2;
4713 		    else if (n2 >= len)
4714 			n2 = len - 1;
4715 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
4716 			n2 = -1;
4717 		    l = list_alloc();
4718 		    if (l == NULL)
4719 			return FAIL;
4720 		    for (item = list_find(rettv->vval.v_list, n1);
4721 							       n1 <= n2; ++n1)
4722 		    {
4723 			if (list_append_tv(l, &item->li_tv) == FAIL)
4724 			{
4725 			    list_free(l);
4726 			    return FAIL;
4727 			}
4728 			item = item->li_next;
4729 		    }
4730 		    clear_tv(rettv);
4731 		    rettv_list_set(rettv, l);
4732 		}
4733 		else
4734 		{
4735 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
4736 		    clear_tv(rettv);
4737 		    *rettv = var1;
4738 		}
4739 		break;
4740 
4741 	    case VAR_DICT:
4742 		if (range)
4743 		{
4744 		    if (verbose)
4745 			EMSG(_(e_dictrange));
4746 		    if (len == -1)
4747 			clear_tv(&var1);
4748 		    return FAIL;
4749 		}
4750 		{
4751 		    dictitem_T	*item;
4752 
4753 		    if (len == -1)
4754 		    {
4755 			key = get_tv_string_chk(&var1);
4756 			if (key == NULL)
4757 			{
4758 			    clear_tv(&var1);
4759 			    return FAIL;
4760 			}
4761 		    }
4762 
4763 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
4764 
4765 		    if (item == NULL && verbose)
4766 			EMSG2(_(e_dictkey), key);
4767 		    if (len == -1)
4768 			clear_tv(&var1);
4769 		    if (item == NULL)
4770 			return FAIL;
4771 
4772 		    copy_tv(&item->di_tv, &var1);
4773 		    clear_tv(rettv);
4774 		    *rettv = var1;
4775 		}
4776 		break;
4777 	}
4778     }
4779 
4780     return OK;
4781 }
4782 
4783 /*
4784  * Get an option value.
4785  * "arg" points to the '&' or '+' before the option name.
4786  * "arg" is advanced to character after the option name.
4787  * Return OK or FAIL.
4788  */
4789     int
4790 get_option_tv(
4791     char_u	**arg,
4792     typval_T	*rettv,	/* when NULL, only check if option exists */
4793     int		evaluate)
4794 {
4795     char_u	*option_end;
4796     long	numval;
4797     char_u	*stringval;
4798     int		opt_type;
4799     int		c;
4800     int		working = (**arg == '+');    /* has("+option") */
4801     int		ret = OK;
4802     int		opt_flags;
4803 
4804     /*
4805      * Isolate the option name and find its value.
4806      */
4807     option_end = find_option_end(arg, &opt_flags);
4808     if (option_end == NULL)
4809     {
4810 	if (rettv != NULL)
4811 	    EMSG2(_("E112: Option name missing: %s"), *arg);
4812 	return FAIL;
4813     }
4814 
4815     if (!evaluate)
4816     {
4817 	*arg = option_end;
4818 	return OK;
4819     }
4820 
4821     c = *option_end;
4822     *option_end = NUL;
4823     opt_type = get_option_value(*arg, &numval,
4824 			       rettv == NULL ? NULL : &stringval, opt_flags);
4825 
4826     if (opt_type == -3)			/* invalid name */
4827     {
4828 	if (rettv != NULL)
4829 	    EMSG2(_("E113: Unknown option: %s"), *arg);
4830 	ret = FAIL;
4831     }
4832     else if (rettv != NULL)
4833     {
4834 	if (opt_type == -2)		/* hidden string option */
4835 	{
4836 	    rettv->v_type = VAR_STRING;
4837 	    rettv->vval.v_string = NULL;
4838 	}
4839 	else if (opt_type == -1)	/* hidden number option */
4840 	{
4841 	    rettv->v_type = VAR_NUMBER;
4842 	    rettv->vval.v_number = 0;
4843 	}
4844 	else if (opt_type == 1)		/* number option */
4845 	{
4846 	    rettv->v_type = VAR_NUMBER;
4847 	    rettv->vval.v_number = numval;
4848 	}
4849 	else				/* string option */
4850 	{
4851 	    rettv->v_type = VAR_STRING;
4852 	    rettv->vval.v_string = stringval;
4853 	}
4854     }
4855     else if (working && (opt_type == -2 || opt_type == -1))
4856 	ret = FAIL;
4857 
4858     *option_end = c;		    /* put back for error messages */
4859     *arg = option_end;
4860 
4861     return ret;
4862 }
4863 
4864 /*
4865  * Allocate a variable for a string constant.
4866  * Return OK or FAIL.
4867  */
4868     static int
4869 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
4870 {
4871     char_u	*p;
4872     char_u	*name;
4873     int		extra = 0;
4874 
4875     /*
4876      * Find the end of the string, skipping backslashed characters.
4877      */
4878     for (p = *arg + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
4879     {
4880 	if (*p == '\\' && p[1] != NUL)
4881 	{
4882 	    ++p;
4883 	    /* A "\<x>" form occupies at least 4 characters, and produces up
4884 	     * to 6 characters: reserve space for 2 extra */
4885 	    if (*p == '<')
4886 		extra += 2;
4887 	}
4888     }
4889 
4890     if (*p != '"')
4891     {
4892 	EMSG2(_("E114: Missing quote: %s"), *arg);
4893 	return FAIL;
4894     }
4895 
4896     /* If only parsing, set *arg and return here */
4897     if (!evaluate)
4898     {
4899 	*arg = p + 1;
4900 	return OK;
4901     }
4902 
4903     /*
4904      * Copy the string into allocated memory, handling backslashed
4905      * characters.
4906      */
4907     name = alloc((unsigned)(p - *arg + extra));
4908     if (name == NULL)
4909 	return FAIL;
4910     rettv->v_type = VAR_STRING;
4911     rettv->vval.v_string = name;
4912 
4913     for (p = *arg + 1; *p != NUL && *p != '"'; )
4914     {
4915 	if (*p == '\\')
4916 	{
4917 	    switch (*++p)
4918 	    {
4919 		case 'b': *name++ = BS; ++p; break;
4920 		case 'e': *name++ = ESC; ++p; break;
4921 		case 'f': *name++ = FF; ++p; break;
4922 		case 'n': *name++ = NL; ++p; break;
4923 		case 'r': *name++ = CAR; ++p; break;
4924 		case 't': *name++ = TAB; ++p; break;
4925 
4926 		case 'X': /* hex: "\x1", "\x12" */
4927 		case 'x':
4928 		case 'u': /* Unicode: "\u0023" */
4929 		case 'U':
4930 			  if (vim_isxdigit(p[1]))
4931 			  {
4932 			      int	n, nr;
4933 			      int	c = toupper(*p);
4934 
4935 			      if (c == 'X')
4936 				  n = 2;
4937 			      else if (*p == 'u')
4938 				  n = 4;
4939 			      else
4940 				  n = 8;
4941 			      nr = 0;
4942 			      while (--n >= 0 && vim_isxdigit(p[1]))
4943 			      {
4944 				  ++p;
4945 				  nr = (nr << 4) + hex2nr(*p);
4946 			      }
4947 			      ++p;
4948 #ifdef FEAT_MBYTE
4949 			      /* For "\u" store the number according to
4950 			       * 'encoding'. */
4951 			      if (c != 'X')
4952 				  name += (*mb_char2bytes)(nr, name);
4953 			      else
4954 #endif
4955 				  *name++ = nr;
4956 			  }
4957 			  break;
4958 
4959 			  /* octal: "\1", "\12", "\123" */
4960 		case '0':
4961 		case '1':
4962 		case '2':
4963 		case '3':
4964 		case '4':
4965 		case '5':
4966 		case '6':
4967 		case '7': *name = *p++ - '0';
4968 			  if (*p >= '0' && *p <= '7')
4969 			  {
4970 			      *name = (*name << 3) + *p++ - '0';
4971 			      if (*p >= '0' && *p <= '7')
4972 				  *name = (*name << 3) + *p++ - '0';
4973 			  }
4974 			  ++name;
4975 			  break;
4976 
4977 			    /* Special key, e.g.: "\<C-W>" */
4978 		case '<': extra = trans_special(&p, name, TRUE, TRUE);
4979 			  if (extra != 0)
4980 			  {
4981 			      name += extra;
4982 			      break;
4983 			  }
4984 			  /* FALLTHROUGH */
4985 
4986 		default:  MB_COPY_CHAR(p, name);
4987 			  break;
4988 	    }
4989 	}
4990 	else
4991 	    MB_COPY_CHAR(p, name);
4992 
4993     }
4994     *name = NUL;
4995     if (*p != NUL) /* just in case */
4996 	++p;
4997     *arg = p;
4998 
4999     return OK;
5000 }
5001 
5002 /*
5003  * Allocate a variable for a 'str''ing' constant.
5004  * Return OK or FAIL.
5005  */
5006     static int
5007 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
5008 {
5009     char_u	*p;
5010     char_u	*str;
5011     int		reduce = 0;
5012 
5013     /*
5014      * Find the end of the string, skipping ''.
5015      */
5016     for (p = *arg + 1; *p != NUL; MB_PTR_ADV(p))
5017     {
5018 	if (*p == '\'')
5019 	{
5020 	    if (p[1] != '\'')
5021 		break;
5022 	    ++reduce;
5023 	    ++p;
5024 	}
5025     }
5026 
5027     if (*p != '\'')
5028     {
5029 	EMSG2(_("E115: Missing quote: %s"), *arg);
5030 	return FAIL;
5031     }
5032 
5033     /* If only parsing return after setting "*arg" */
5034     if (!evaluate)
5035     {
5036 	*arg = p + 1;
5037 	return OK;
5038     }
5039 
5040     /*
5041      * Copy the string into allocated memory, handling '' to ' reduction.
5042      */
5043     str = alloc((unsigned)((p - *arg) - reduce));
5044     if (str == NULL)
5045 	return FAIL;
5046     rettv->v_type = VAR_STRING;
5047     rettv->vval.v_string = str;
5048 
5049     for (p = *arg + 1; *p != NUL; )
5050     {
5051 	if (*p == '\'')
5052 	{
5053 	    if (p[1] != '\'')
5054 		break;
5055 	    ++p;
5056 	}
5057 	MB_COPY_CHAR(p, str);
5058     }
5059     *str = NUL;
5060     *arg = p + 1;
5061 
5062     return OK;
5063 }
5064 
5065 /*
5066  * Return the function name of the partial.
5067  */
5068     char_u *
5069 partial_name(partial_T *pt)
5070 {
5071     if (pt->pt_name != NULL)
5072 	return pt->pt_name;
5073     return pt->pt_func->uf_name;
5074 }
5075 
5076     static void
5077 partial_free(partial_T *pt)
5078 {
5079     int i;
5080 
5081     for (i = 0; i < pt->pt_argc; ++i)
5082 	clear_tv(&pt->pt_argv[i]);
5083     vim_free(pt->pt_argv);
5084     dict_unref(pt->pt_dict);
5085     if (pt->pt_name != NULL)
5086     {
5087 	func_unref(pt->pt_name);
5088 	vim_free(pt->pt_name);
5089     }
5090     else
5091 	func_ptr_unref(pt->pt_func);
5092     vim_free(pt);
5093 }
5094 
5095 /*
5096  * Unreference a closure: decrement the reference count and free it when it
5097  * becomes zero.
5098  */
5099     void
5100 partial_unref(partial_T *pt)
5101 {
5102     if (pt != NULL && --pt->pt_refcount <= 0)
5103 	partial_free(pt);
5104 }
5105 
5106 static int tv_equal_recurse_limit;
5107 
5108     static int
5109 func_equal(
5110     typval_T *tv1,
5111     typval_T *tv2,
5112     int	     ic)	    /* ignore case */
5113 {
5114     char_u	*s1, *s2;
5115     dict_T	*d1, *d2;
5116     int		a1, a2;
5117     int		i;
5118 
5119     /* empty and NULL function name considered the same */
5120     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
5121 					   : partial_name(tv1->vval.v_partial);
5122     if (s1 != NULL && *s1 == NUL)
5123 	s1 = NULL;
5124     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
5125 					   : partial_name(tv2->vval.v_partial);
5126     if (s2 != NULL && *s2 == NUL)
5127 	s2 = NULL;
5128     if (s1 == NULL || s2 == NULL)
5129     {
5130 	if (s1 != s2)
5131 	    return FALSE;
5132     }
5133     else if (STRCMP(s1, s2) != 0)
5134 	return FALSE;
5135 
5136     /* empty dict and NULL dict is different */
5137     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
5138     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
5139     if (d1 == NULL || d2 == NULL)
5140     {
5141 	if (d1 != d2)
5142 	    return FALSE;
5143     }
5144     else if (!dict_equal(d1, d2, ic, TRUE))
5145 	return FALSE;
5146 
5147     /* empty list and no list considered the same */
5148     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
5149     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
5150     if (a1 != a2)
5151 	return FALSE;
5152     for (i = 0; i < a1; ++i)
5153 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
5154 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
5155 	    return FALSE;
5156 
5157     return TRUE;
5158 }
5159 
5160 /*
5161  * Return TRUE if "tv1" and "tv2" have the same value.
5162  * Compares the items just like "==" would compare them, but strings and
5163  * numbers are different.  Floats and numbers are also different.
5164  */
5165     int
5166 tv_equal(
5167     typval_T *tv1,
5168     typval_T *tv2,
5169     int	     ic,	    /* ignore case */
5170     int	     recursive)	    /* TRUE when used recursively */
5171 {
5172     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
5173     char_u	*s1, *s2;
5174     static int  recursive_cnt = 0;	    /* catch recursive loops */
5175     int		r;
5176 
5177     /* Catch lists and dicts that have an endless loop by limiting
5178      * recursiveness to a limit.  We guess they are equal then.
5179      * A fixed limit has the problem of still taking an awful long time.
5180      * Reduce the limit every time running into it. That should work fine for
5181      * deeply linked structures that are not recursively linked and catch
5182      * recursiveness quickly. */
5183     if (!recursive)
5184 	tv_equal_recurse_limit = 1000;
5185     if (recursive_cnt >= tv_equal_recurse_limit)
5186     {
5187 	--tv_equal_recurse_limit;
5188 	return TRUE;
5189     }
5190 
5191     /* For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
5192      * arguments. */
5193     if ((tv1->v_type == VAR_FUNC
5194 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
5195 	    && (tv2->v_type == VAR_FUNC
5196 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
5197     {
5198 	++recursive_cnt;
5199 	r = func_equal(tv1, tv2, ic);
5200 	--recursive_cnt;
5201 	return r;
5202     }
5203 
5204     if (tv1->v_type != tv2->v_type)
5205 	return FALSE;
5206 
5207     switch (tv1->v_type)
5208     {
5209 	case VAR_LIST:
5210 	    ++recursive_cnt;
5211 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
5212 	    --recursive_cnt;
5213 	    return r;
5214 
5215 	case VAR_DICT:
5216 	    ++recursive_cnt;
5217 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
5218 	    --recursive_cnt;
5219 	    return r;
5220 
5221 	case VAR_NUMBER:
5222 	    return tv1->vval.v_number == tv2->vval.v_number;
5223 
5224 	case VAR_STRING:
5225 	    s1 = get_tv_string_buf(tv1, buf1);
5226 	    s2 = get_tv_string_buf(tv2, buf2);
5227 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
5228 
5229 	case VAR_SPECIAL:
5230 	    return tv1->vval.v_number == tv2->vval.v_number;
5231 
5232 	case VAR_FLOAT:
5233 #ifdef FEAT_FLOAT
5234 	    return tv1->vval.v_float == tv2->vval.v_float;
5235 #endif
5236 	case VAR_JOB:
5237 #ifdef FEAT_JOB_CHANNEL
5238 	    return tv1->vval.v_job == tv2->vval.v_job;
5239 #endif
5240 	case VAR_CHANNEL:
5241 #ifdef FEAT_JOB_CHANNEL
5242 	    return tv1->vval.v_channel == tv2->vval.v_channel;
5243 #endif
5244 	case VAR_FUNC:
5245 	case VAR_PARTIAL:
5246 	case VAR_UNKNOWN:
5247 	    break;
5248     }
5249 
5250     /* VAR_UNKNOWN can be the result of a invalid expression, let's say it
5251      * does not equal anything, not even itself. */
5252     return FALSE;
5253 }
5254 
5255 /*
5256  * Return the next (unique) copy ID.
5257  * Used for serializing nested structures.
5258  */
5259     int
5260 get_copyID(void)
5261 {
5262     current_copyID += COPYID_INC;
5263     return current_copyID;
5264 }
5265 
5266 /*
5267  * Garbage collection for lists and dictionaries.
5268  *
5269  * We use reference counts to be able to free most items right away when they
5270  * are no longer used.  But for composite items it's possible that it becomes
5271  * unused while the reference count is > 0: When there is a recursive
5272  * reference.  Example:
5273  *	:let l = [1, 2, 3]
5274  *	:let d = {9: l}
5275  *	:let l[1] = d
5276  *
5277  * Since this is quite unusual we handle this with garbage collection: every
5278  * once in a while find out which lists and dicts are not referenced from any
5279  * variable.
5280  *
5281  * Here is a good reference text about garbage collection (refers to Python
5282  * but it applies to all reference-counting mechanisms):
5283  *	http://python.ca/nas/python/gc/
5284  */
5285 
5286 /*
5287  * Do garbage collection for lists and dicts.
5288  * When "testing" is TRUE this is called from test_garbagecollect_now().
5289  * Return TRUE if some memory was freed.
5290  */
5291     int
5292 garbage_collect(int testing)
5293 {
5294     int		copyID;
5295     int		abort = FALSE;
5296     buf_T	*buf;
5297     win_T	*wp;
5298     int		i;
5299     int		did_free = FALSE;
5300     tabpage_T	*tp;
5301 
5302     if (!testing)
5303     {
5304 	/* Only do this once. */
5305 	want_garbage_collect = FALSE;
5306 	may_garbage_collect = FALSE;
5307 	garbage_collect_at_exit = FALSE;
5308     }
5309 
5310     /* We advance by two because we add one for items referenced through
5311      * previous_funccal. */
5312     copyID = get_copyID();
5313 
5314     /*
5315      * 1. Go through all accessible variables and mark all lists and dicts
5316      *    with copyID.
5317      */
5318 
5319     /* Don't free variables in the previous_funccal list unless they are only
5320      * referenced through previous_funccal.  This must be first, because if
5321      * the item is referenced elsewhere the funccal must not be freed. */
5322     abort = abort || set_ref_in_previous_funccal(copyID);
5323 
5324     /* script-local variables */
5325     for (i = 1; i <= ga_scripts.ga_len; ++i)
5326 	abort = abort || set_ref_in_ht(&SCRIPT_VARS(i), copyID, NULL);
5327 
5328     /* buffer-local variables */
5329     FOR_ALL_BUFFERS(buf)
5330 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
5331 								  NULL, NULL);
5332 
5333     /* window-local variables */
5334     FOR_ALL_TAB_WINDOWS(tp, wp)
5335 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
5336 								  NULL, NULL);
5337 #ifdef FEAT_AUTOCMD
5338     if (aucmd_win != NULL)
5339 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
5340 								  NULL, NULL);
5341 #endif
5342 
5343     /* tabpage-local variables */
5344     FOR_ALL_TABPAGES(tp)
5345 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
5346 								  NULL, NULL);
5347     /* global variables */
5348     abort = abort || set_ref_in_ht(&globvarht, copyID, NULL);
5349 
5350     /* function-local variables */
5351     abort = abort || set_ref_in_call_stack(copyID);
5352 
5353     /* named functions (matters for closures) */
5354     abort = abort || set_ref_in_functions(copyID);
5355 
5356     /* function call arguments, if v:testing is set. */
5357     abort = abort || set_ref_in_func_args(copyID);
5358 
5359     /* v: vars */
5360     abort = abort || set_ref_in_ht(&vimvarht, copyID, NULL);
5361 
5362 #ifdef FEAT_LUA
5363     abort = abort || set_ref_in_lua(copyID);
5364 #endif
5365 
5366 #ifdef FEAT_PYTHON
5367     abort = abort || set_ref_in_python(copyID);
5368 #endif
5369 
5370 #ifdef FEAT_PYTHON3
5371     abort = abort || set_ref_in_python3(copyID);
5372 #endif
5373 
5374 #ifdef FEAT_JOB_CHANNEL
5375     abort = abort || set_ref_in_channel(copyID);
5376     abort = abort || set_ref_in_job(copyID);
5377 #endif
5378 #ifdef FEAT_NETBEANS_INTG
5379     abort = abort || set_ref_in_nb_channel(copyID);
5380 #endif
5381 
5382 #ifdef FEAT_TIMERS
5383     abort = abort || set_ref_in_timer(copyID);
5384 #endif
5385 
5386 #ifdef FEAT_QUICKFIX
5387     abort = abort || set_ref_in_quickfix(copyID);
5388 #endif
5389 
5390 #ifdef FEAT_TERMINAL
5391     abort = abort || set_ref_in_term(copyID);
5392 #endif
5393 
5394     if (!abort)
5395     {
5396 	/*
5397 	 * 2. Free lists and dictionaries that are not referenced.
5398 	 */
5399 	did_free = free_unref_items(copyID);
5400 
5401 	/*
5402 	 * 3. Check if any funccal can be freed now.
5403 	 *    This may call us back recursively.
5404 	 */
5405 	free_unref_funccal(copyID, testing);
5406     }
5407     else if (p_verbose > 0)
5408     {
5409 	verb_msg((char_u *)_("Not enough memory to set references, garbage collection aborted!"));
5410     }
5411 
5412     return did_free;
5413 }
5414 
5415 /*
5416  * Free lists, dictionaries, channels and jobs that are no longer referenced.
5417  */
5418     static int
5419 free_unref_items(int copyID)
5420 {
5421     int		did_free = FALSE;
5422 
5423     /* Let all "free" functions know that we are here.  This means no
5424      * dictionaries, lists, channels or jobs are to be freed, because we will
5425      * do that here. */
5426     in_free_unref_items = TRUE;
5427 
5428     /*
5429      * PASS 1: free the contents of the items.  We don't free the items
5430      * themselves yet, so that it is possible to decrement refcount counters
5431      */
5432 
5433     /* Go through the list of dicts and free items without the copyID. */
5434     did_free |= dict_free_nonref(copyID);
5435 
5436     /* Go through the list of lists and free items without the copyID. */
5437     did_free |= list_free_nonref(copyID);
5438 
5439 #ifdef FEAT_JOB_CHANNEL
5440     /* Go through the list of jobs and free items without the copyID. This
5441      * must happen before doing channels, because jobs refer to channels, but
5442      * the reference from the channel to the job isn't tracked. */
5443     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
5444 
5445     /* Go through the list of channels and free items without the copyID.  */
5446     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
5447 #endif
5448 
5449     /*
5450      * PASS 2: free the items themselves.
5451      */
5452     dict_free_items(copyID);
5453     list_free_items(copyID);
5454 
5455 #ifdef FEAT_JOB_CHANNEL
5456     /* Go through the list of jobs and free items without the copyID. This
5457      * must happen before doing channels, because jobs refer to channels, but
5458      * the reference from the channel to the job isn't tracked. */
5459     free_unused_jobs(copyID, COPYID_MASK);
5460 
5461     /* Go through the list of channels and free items without the copyID.  */
5462     free_unused_channels(copyID, COPYID_MASK);
5463 #endif
5464 
5465     in_free_unref_items = FALSE;
5466 
5467     return did_free;
5468 }
5469 
5470 /*
5471  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
5472  * "list_stack" is used to add lists to be marked.  Can be NULL.
5473  *
5474  * Returns TRUE if setting references failed somehow.
5475  */
5476     int
5477 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
5478 {
5479     int		todo;
5480     int		abort = FALSE;
5481     hashitem_T	*hi;
5482     hashtab_T	*cur_ht;
5483     ht_stack_T	*ht_stack = NULL;
5484     ht_stack_T	*tempitem;
5485 
5486     cur_ht = ht;
5487     for (;;)
5488     {
5489 	if (!abort)
5490 	{
5491 	    /* Mark each item in the hashtab.  If the item contains a hashtab
5492 	     * it is added to ht_stack, if it contains a list it is added to
5493 	     * list_stack. */
5494 	    todo = (int)cur_ht->ht_used;
5495 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
5496 		if (!HASHITEM_EMPTY(hi))
5497 		{
5498 		    --todo;
5499 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
5500 						       &ht_stack, list_stack);
5501 		}
5502 	}
5503 
5504 	if (ht_stack == NULL)
5505 	    break;
5506 
5507 	/* take an item from the stack */
5508 	cur_ht = ht_stack->ht;
5509 	tempitem = ht_stack;
5510 	ht_stack = ht_stack->prev;
5511 	free(tempitem);
5512     }
5513 
5514     return abort;
5515 }
5516 
5517 /*
5518  * Mark all lists and dicts referenced through list "l" with "copyID".
5519  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5520  *
5521  * Returns TRUE if setting references failed somehow.
5522  */
5523     int
5524 set_ref_in_list(list_T *l, int copyID, ht_stack_T **ht_stack)
5525 {
5526     listitem_T	 *li;
5527     int		 abort = FALSE;
5528     list_T	 *cur_l;
5529     list_stack_T *list_stack = NULL;
5530     list_stack_T *tempitem;
5531 
5532     cur_l = l;
5533     for (;;)
5534     {
5535 	if (!abort)
5536 	    /* Mark each item in the list.  If the item contains a hashtab
5537 	     * it is added to ht_stack, if it contains a list it is added to
5538 	     * list_stack. */
5539 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
5540 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
5541 						       ht_stack, &list_stack);
5542 	if (list_stack == NULL)
5543 	    break;
5544 
5545 	/* take an item from the stack */
5546 	cur_l = list_stack->list;
5547 	tempitem = list_stack;
5548 	list_stack = list_stack->prev;
5549 	free(tempitem);
5550     }
5551 
5552     return abort;
5553 }
5554 
5555 /*
5556  * Mark all lists and dicts referenced through typval "tv" with "copyID".
5557  * "list_stack" is used to add lists to be marked.  Can be NULL.
5558  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
5559  *
5560  * Returns TRUE if setting references failed somehow.
5561  */
5562     int
5563 set_ref_in_item(
5564     typval_T	    *tv,
5565     int		    copyID,
5566     ht_stack_T	    **ht_stack,
5567     list_stack_T    **list_stack)
5568 {
5569     int		abort = FALSE;
5570 
5571     if (tv->v_type == VAR_DICT)
5572     {
5573 	dict_T	*dd = tv->vval.v_dict;
5574 
5575 	if (dd != NULL && dd->dv_copyID != copyID)
5576 	{
5577 	    /* Didn't see this dict yet. */
5578 	    dd->dv_copyID = copyID;
5579 	    if (ht_stack == NULL)
5580 	    {
5581 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
5582 	    }
5583 	    else
5584 	    {
5585 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
5586 		if (newitem == NULL)
5587 		    abort = TRUE;
5588 		else
5589 		{
5590 		    newitem->ht = &dd->dv_hashtab;
5591 		    newitem->prev = *ht_stack;
5592 		    *ht_stack = newitem;
5593 		}
5594 	    }
5595 	}
5596     }
5597     else if (tv->v_type == VAR_LIST)
5598     {
5599 	list_T	*ll = tv->vval.v_list;
5600 
5601 	if (ll != NULL && ll->lv_copyID != copyID)
5602 	{
5603 	    /* Didn't see this list yet. */
5604 	    ll->lv_copyID = copyID;
5605 	    if (list_stack == NULL)
5606 	    {
5607 		abort = set_ref_in_list(ll, copyID, ht_stack);
5608 	    }
5609 	    else
5610 	    {
5611 		list_stack_T *newitem = (list_stack_T*)malloc(
5612 							sizeof(list_stack_T));
5613 		if (newitem == NULL)
5614 		    abort = TRUE;
5615 		else
5616 		{
5617 		    newitem->list = ll;
5618 		    newitem->prev = *list_stack;
5619 		    *list_stack = newitem;
5620 		}
5621 	    }
5622 	}
5623     }
5624     else if (tv->v_type == VAR_FUNC)
5625     {
5626 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
5627     }
5628     else if (tv->v_type == VAR_PARTIAL)
5629     {
5630 	partial_T	*pt = tv->vval.v_partial;
5631 	int		i;
5632 
5633 	/* A partial does not have a copyID, because it cannot contain itself.
5634 	 */
5635 	if (pt != NULL)
5636 	{
5637 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
5638 
5639 	    if (pt->pt_dict != NULL)
5640 	    {
5641 		typval_T dtv;
5642 
5643 		dtv.v_type = VAR_DICT;
5644 		dtv.vval.v_dict = pt->pt_dict;
5645 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5646 	    }
5647 
5648 	    for (i = 0; i < pt->pt_argc; ++i)
5649 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
5650 							ht_stack, list_stack);
5651 	}
5652     }
5653 #ifdef FEAT_JOB_CHANNEL
5654     else if (tv->v_type == VAR_JOB)
5655     {
5656 	job_T	    *job = tv->vval.v_job;
5657 	typval_T    dtv;
5658 
5659 	if (job != NULL && job->jv_copyID != copyID)
5660 	{
5661 	    job->jv_copyID = copyID;
5662 	    if (job->jv_channel != NULL)
5663 	    {
5664 		dtv.v_type = VAR_CHANNEL;
5665 		dtv.vval.v_channel = job->jv_channel;
5666 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5667 	    }
5668 	    if (job->jv_exit_partial != NULL)
5669 	    {
5670 		dtv.v_type = VAR_PARTIAL;
5671 		dtv.vval.v_partial = job->jv_exit_partial;
5672 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5673 	    }
5674 	}
5675     }
5676     else if (tv->v_type == VAR_CHANNEL)
5677     {
5678 	channel_T   *ch =tv->vval.v_channel;
5679 	ch_part_T   part;
5680 	typval_T    dtv;
5681 	jsonq_T	    *jq;
5682 	cbq_T	    *cq;
5683 
5684 	if (ch != NULL && ch->ch_copyID != copyID)
5685 	{
5686 	    ch->ch_copyID = copyID;
5687 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
5688 	    {
5689 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
5690 							     jq = jq->jq_next)
5691 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
5692 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
5693 							     cq = cq->cq_next)
5694 		    if (cq->cq_partial != NULL)
5695 		    {
5696 			dtv.v_type = VAR_PARTIAL;
5697 			dtv.vval.v_partial = cq->cq_partial;
5698 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5699 		    }
5700 		if (ch->ch_part[part].ch_partial != NULL)
5701 		{
5702 		    dtv.v_type = VAR_PARTIAL;
5703 		    dtv.vval.v_partial = ch->ch_part[part].ch_partial;
5704 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5705 		}
5706 	    }
5707 	    if (ch->ch_partial != NULL)
5708 	    {
5709 		dtv.v_type = VAR_PARTIAL;
5710 		dtv.vval.v_partial = ch->ch_partial;
5711 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5712 	    }
5713 	    if (ch->ch_close_partial != NULL)
5714 	    {
5715 		dtv.v_type = VAR_PARTIAL;
5716 		dtv.vval.v_partial = ch->ch_close_partial;
5717 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
5718 	    }
5719 	}
5720     }
5721 #endif
5722     return abort;
5723 }
5724 
5725     static char *
5726 get_var_special_name(int nr)
5727 {
5728     switch (nr)
5729     {
5730 	case VVAL_FALSE: return "v:false";
5731 	case VVAL_TRUE:  return "v:true";
5732 	case VVAL_NONE:  return "v:none";
5733 	case VVAL_NULL:  return "v:null";
5734     }
5735     internal_error("get_var_special_name()");
5736     return "42";
5737 }
5738 
5739 /*
5740  * Return a string with the string representation of a variable.
5741  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5742  * "numbuf" is used for a number.
5743  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5744  * When both "echo_style" and "composite_val" are FALSE, put quotes around
5745  * stings as "string()", otherwise does not put quotes around strings, as
5746  * ":echo" displays values.
5747  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
5748  * are replaced with "...".
5749  * May return NULL.
5750  */
5751     char_u *
5752 echo_string_core(
5753     typval_T	*tv,
5754     char_u	**tofree,
5755     char_u	*numbuf,
5756     int		copyID,
5757     int		echo_style,
5758     int		restore_copyID,
5759     int		composite_val)
5760 {
5761     static int	recurse = 0;
5762     char_u	*r = NULL;
5763 
5764     if (recurse >= DICT_MAXNEST)
5765     {
5766 	if (!did_echo_string_emsg)
5767 	{
5768 	    /* Only give this message once for a recursive call to avoid
5769 	     * flooding the user with errors.  And stop iterating over lists
5770 	     * and dicts. */
5771 	    did_echo_string_emsg = TRUE;
5772 	    EMSG(_("E724: variable nested too deep for displaying"));
5773 	}
5774 	*tofree = NULL;
5775 	return (char_u *)"{E724}";
5776     }
5777     ++recurse;
5778 
5779     switch (tv->v_type)
5780     {
5781 	case VAR_STRING:
5782 	    if (echo_style && !composite_val)
5783 	    {
5784 		*tofree = NULL;
5785 		r = tv->vval.v_string;
5786 		if (r == NULL)
5787 		    r = (char_u *)"";
5788 	    }
5789 	    else
5790 	    {
5791 		*tofree = string_quote(tv->vval.v_string, FALSE);
5792 		r = *tofree;
5793 	    }
5794 	    break;
5795 
5796 	case VAR_FUNC:
5797 	    if (echo_style)
5798 	    {
5799 		*tofree = NULL;
5800 		r = tv->vval.v_string;
5801 	    }
5802 	    else
5803 	    {
5804 		*tofree = string_quote(tv->vval.v_string, TRUE);
5805 		r = *tofree;
5806 	    }
5807 	    break;
5808 
5809 	case VAR_PARTIAL:
5810 	    {
5811 		partial_T   *pt = tv->vval.v_partial;
5812 		char_u	    *fname = string_quote(pt == NULL ? NULL
5813 						    : partial_name(pt), FALSE);
5814 		garray_T    ga;
5815 		int	    i;
5816 		char_u	    *tf;
5817 
5818 		ga_init2(&ga, 1, 100);
5819 		ga_concat(&ga, (char_u *)"function(");
5820 		if (fname != NULL)
5821 		{
5822 		    ga_concat(&ga, fname);
5823 		    vim_free(fname);
5824 		}
5825 		if (pt != NULL && pt->pt_argc > 0)
5826 		{
5827 		    ga_concat(&ga, (char_u *)", [");
5828 		    for (i = 0; i < pt->pt_argc; ++i)
5829 		    {
5830 			if (i > 0)
5831 			    ga_concat(&ga, (char_u *)", ");
5832 			ga_concat(&ga,
5833 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
5834 			vim_free(tf);
5835 		    }
5836 		    ga_concat(&ga, (char_u *)"]");
5837 		}
5838 		if (pt != NULL && pt->pt_dict != NULL)
5839 		{
5840 		    typval_T dtv;
5841 
5842 		    ga_concat(&ga, (char_u *)", ");
5843 		    dtv.v_type = VAR_DICT;
5844 		    dtv.vval.v_dict = pt->pt_dict;
5845 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
5846 		    vim_free(tf);
5847 		}
5848 		ga_concat(&ga, (char_u *)")");
5849 
5850 		*tofree = ga.ga_data;
5851 		r = *tofree;
5852 		break;
5853 	    }
5854 
5855 	case VAR_LIST:
5856 	    if (tv->vval.v_list == NULL)
5857 	    {
5858 		*tofree = NULL;
5859 		r = NULL;
5860 	    }
5861 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
5862 		    && tv->vval.v_list->lv_len > 0)
5863 	    {
5864 		*tofree = NULL;
5865 		r = (char_u *)"[...]";
5866 	    }
5867 	    else
5868 	    {
5869 		int old_copyID = tv->vval.v_list->lv_copyID;
5870 
5871 		tv->vval.v_list->lv_copyID = copyID;
5872 		*tofree = list2string(tv, copyID, restore_copyID);
5873 		if (restore_copyID)
5874 		    tv->vval.v_list->lv_copyID = old_copyID;
5875 		r = *tofree;
5876 	    }
5877 	    break;
5878 
5879 	case VAR_DICT:
5880 	    if (tv->vval.v_dict == NULL)
5881 	    {
5882 		*tofree = NULL;
5883 		r = NULL;
5884 	    }
5885 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
5886 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
5887 	    {
5888 		*tofree = NULL;
5889 		r = (char_u *)"{...}";
5890 	    }
5891 	    else
5892 	    {
5893 		int old_copyID = tv->vval.v_dict->dv_copyID;
5894 		tv->vval.v_dict->dv_copyID = copyID;
5895 		*tofree = dict2string(tv, copyID, restore_copyID);
5896 		if (restore_copyID)
5897 		    tv->vval.v_dict->dv_copyID = old_copyID;
5898 		r = *tofree;
5899 	    }
5900 	    break;
5901 
5902 	case VAR_NUMBER:
5903 	case VAR_UNKNOWN:
5904 	    *tofree = NULL;
5905 	    r = get_tv_string_buf(tv, numbuf);
5906 	    break;
5907 
5908 	case VAR_JOB:
5909 	case VAR_CHANNEL:
5910 	    *tofree = NULL;
5911 	    r = get_tv_string_buf(tv, numbuf);
5912 	    if (composite_val)
5913 	    {
5914 		*tofree = string_quote(r, FALSE);
5915 		r = *tofree;
5916 	    }
5917 	    break;
5918 
5919 	case VAR_FLOAT:
5920 #ifdef FEAT_FLOAT
5921 	    *tofree = NULL;
5922 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
5923 	    r = numbuf;
5924 	    break;
5925 #endif
5926 
5927 	case VAR_SPECIAL:
5928 	    *tofree = NULL;
5929 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
5930 	    break;
5931     }
5932 
5933     if (--recurse == 0)
5934 	did_echo_string_emsg = FALSE;
5935     return r;
5936 }
5937 
5938 /*
5939  * Return a string with the string representation of a variable.
5940  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5941  * "numbuf" is used for a number.
5942  * Does not put quotes around strings, as ":echo" displays values.
5943  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5944  * May return NULL.
5945  */
5946     char_u *
5947 echo_string(
5948     typval_T	*tv,
5949     char_u	**tofree,
5950     char_u	*numbuf,
5951     int		copyID)
5952 {
5953     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
5954 }
5955 
5956 /*
5957  * Return a string with the string representation of a variable.
5958  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5959  * "numbuf" is used for a number.
5960  * Puts quotes around strings, so that they can be parsed back by eval().
5961  * May return NULL.
5962  */
5963     char_u *
5964 tv2string(
5965     typval_T	*tv,
5966     char_u	**tofree,
5967     char_u	*numbuf,
5968     int		copyID)
5969 {
5970     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
5971 }
5972 
5973 /*
5974  * Return string "str" in ' quotes, doubling ' characters.
5975  * If "str" is NULL an empty string is assumed.
5976  * If "function" is TRUE make it function('string').
5977  */
5978     char_u *
5979 string_quote(char_u *str, int function)
5980 {
5981     unsigned	len;
5982     char_u	*p, *r, *s;
5983 
5984     len = (function ? 13 : 3);
5985     if (str != NULL)
5986     {
5987 	len += (unsigned)STRLEN(str);
5988 	for (p = str; *p != NUL; MB_PTR_ADV(p))
5989 	    if (*p == '\'')
5990 		++len;
5991     }
5992     s = r = alloc(len);
5993     if (r != NULL)
5994     {
5995 	if (function)
5996 	{
5997 	    STRCPY(r, "function('");
5998 	    r += 10;
5999 	}
6000 	else
6001 	    *r++ = '\'';
6002 	if (str != NULL)
6003 	    for (p = str; *p != NUL; )
6004 	    {
6005 		if (*p == '\'')
6006 		    *r++ = '\'';
6007 		MB_COPY_CHAR(p, r);
6008 	    }
6009 	*r++ = '\'';
6010 	if (function)
6011 	    *r++ = ')';
6012 	*r++ = NUL;
6013     }
6014     return s;
6015 }
6016 
6017 #if defined(FEAT_FLOAT) || defined(PROTO)
6018 /*
6019  * Convert the string "text" to a floating point number.
6020  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
6021  * this always uses a decimal point.
6022  * Returns the length of the text that was consumed.
6023  */
6024     int
6025 string2float(
6026     char_u	*text,
6027     float_T	*value)	    /* result stored here */
6028 {
6029     char	*s = (char *)text;
6030     float_T	f;
6031 
6032     /* MS-Windows does not deal with "inf" and "nan" properly. */
6033     if (STRNICMP(text, "inf", 3) == 0)
6034     {
6035 	*value = INFINITY;
6036 	return 3;
6037     }
6038     if (STRNICMP(text, "-inf", 3) == 0)
6039     {
6040 	*value = -INFINITY;
6041 	return 4;
6042     }
6043     if (STRNICMP(text, "nan", 3) == 0)
6044     {
6045 	*value = NAN;
6046 	return 3;
6047     }
6048     f = strtod(s, &s);
6049     *value = f;
6050     return (int)((char_u *)s - text);
6051 }
6052 #endif
6053 
6054 /*
6055  * Get the value of an environment variable.
6056  * "arg" is pointing to the '$'.  It is advanced to after the name.
6057  * If the environment variable was not set, silently assume it is empty.
6058  * Return FAIL if the name is invalid.
6059  */
6060     static int
6061 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
6062 {
6063     char_u	*string = NULL;
6064     int		len;
6065     int		cc;
6066     char_u	*name;
6067     int		mustfree = FALSE;
6068 
6069     ++*arg;
6070     name = *arg;
6071     len = get_env_len(arg);
6072     if (evaluate)
6073     {
6074 	if (len == 0)
6075 	    return FAIL; /* invalid empty name */
6076 
6077 	cc = name[len];
6078 	name[len] = NUL;
6079 	/* first try vim_getenv(), fast for normal environment vars */
6080 	string = vim_getenv(name, &mustfree);
6081 	if (string != NULL && *string != NUL)
6082 	{
6083 	    if (!mustfree)
6084 		string = vim_strsave(string);
6085 	}
6086 	else
6087 	{
6088 	    if (mustfree)
6089 		vim_free(string);
6090 
6091 	    /* next try expanding things like $VIM and ${HOME} */
6092 	    string = expand_env_save(name - 1);
6093 	    if (string != NULL && *string == '$')
6094 	    {
6095 		vim_free(string);
6096 		string = NULL;
6097 	    }
6098 	}
6099 	name[len] = cc;
6100 
6101 	rettv->v_type = VAR_STRING;
6102 	rettv->vval.v_string = string;
6103     }
6104 
6105     return OK;
6106 }
6107 
6108 
6109 
6110 /*
6111  * Translate a String variable into a position.
6112  * Returns NULL when there is an error.
6113  */
6114     pos_T *
6115 var2fpos(
6116     typval_T	*varp,
6117     int		dollar_lnum,	/* TRUE when $ is last line */
6118     int		*fnum)		/* set to fnum for '0, 'A, etc. */
6119 {
6120     char_u		*name;
6121     static pos_T	pos;
6122     pos_T		*pp;
6123 
6124     /* Argument can be [lnum, col, coladd]. */
6125     if (varp->v_type == VAR_LIST)
6126     {
6127 	list_T		*l;
6128 	int		len;
6129 	int		error = FALSE;
6130 	listitem_T	*li;
6131 
6132 	l = varp->vval.v_list;
6133 	if (l == NULL)
6134 	    return NULL;
6135 
6136 	/* Get the line number */
6137 	pos.lnum = list_find_nr(l, 0L, &error);
6138 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
6139 	    return NULL;	/* invalid line number */
6140 
6141 	/* Get the column number */
6142 	pos.col = list_find_nr(l, 1L, &error);
6143 	if (error)
6144 	    return NULL;
6145 	len = (long)STRLEN(ml_get(pos.lnum));
6146 
6147 	/* We accept "$" for the column number: last column. */
6148 	li = list_find(l, 1L);
6149 	if (li != NULL && li->li_tv.v_type == VAR_STRING
6150 		&& li->li_tv.vval.v_string != NULL
6151 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
6152 	    pos.col = len + 1;
6153 
6154 	/* Accept a position up to the NUL after the line. */
6155 	if (pos.col == 0 || (int)pos.col > len + 1)
6156 	    return NULL;	/* invalid column number */
6157 	--pos.col;
6158 
6159 #ifdef FEAT_VIRTUALEDIT
6160 	/* Get the virtual offset.  Defaults to zero. */
6161 	pos.coladd = list_find_nr(l, 2L, &error);
6162 	if (error)
6163 	    pos.coladd = 0;
6164 #endif
6165 
6166 	return &pos;
6167     }
6168 
6169     name = get_tv_string_chk(varp);
6170     if (name == NULL)
6171 	return NULL;
6172     if (name[0] == '.')				/* cursor */
6173 	return &curwin->w_cursor;
6174     if (name[0] == 'v' && name[1] == NUL)	/* Visual start */
6175     {
6176 	if (VIsual_active)
6177 	    return &VIsual;
6178 	return &curwin->w_cursor;
6179     }
6180     if (name[0] == '\'')			/* mark */
6181     {
6182 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
6183 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
6184 	    return NULL;
6185 	return pp;
6186     }
6187 
6188 #ifdef FEAT_VIRTUALEDIT
6189     pos.coladd = 0;
6190 #endif
6191 
6192     if (name[0] == 'w' && dollar_lnum)
6193     {
6194 	pos.col = 0;
6195 	if (name[1] == '0')		/* "w0": first visible line */
6196 	{
6197 	    update_topline();
6198 	    /* In silent Ex mode topline is zero, but that's not a valid line
6199 	     * number; use one instead. */
6200 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
6201 	    return &pos;
6202 	}
6203 	else if (name[1] == '$')	/* "w$": last visible line */
6204 	{
6205 	    validate_botline();
6206 	    /* In silent Ex mode botline is zero, return zero then. */
6207 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
6208 	    return &pos;
6209 	}
6210     }
6211     else if (name[0] == '$')		/* last column or line */
6212     {
6213 	if (dollar_lnum)
6214 	{
6215 	    pos.lnum = curbuf->b_ml.ml_line_count;
6216 	    pos.col = 0;
6217 	}
6218 	else
6219 	{
6220 	    pos.lnum = curwin->w_cursor.lnum;
6221 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
6222 	}
6223 	return &pos;
6224     }
6225     return NULL;
6226 }
6227 
6228 /*
6229  * Convert list in "arg" into a position and optional file number.
6230  * When "fnump" is NULL there is no file number, only 3 items.
6231  * Note that the column is passed on as-is, the caller may want to decrement
6232  * it to use 1 for the first column.
6233  * Return FAIL when conversion is not possible, doesn't check the position for
6234  * validity.
6235  */
6236     int
6237 list2fpos(
6238     typval_T	*arg,
6239     pos_T	*posp,
6240     int		*fnump,
6241     colnr_T	*curswantp)
6242 {
6243     list_T	*l = arg->vval.v_list;
6244     long	i = 0;
6245     long	n;
6246 
6247     /* List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
6248      * there when "fnump" isn't NULL; "coladd" and "curswant" are optional. */
6249     if (arg->v_type != VAR_LIST
6250 	    || l == NULL
6251 	    || l->lv_len < (fnump == NULL ? 2 : 3)
6252 	    || l->lv_len > (fnump == NULL ? 4 : 5))
6253 	return FAIL;
6254 
6255     if (fnump != NULL)
6256     {
6257 	n = list_find_nr(l, i++, NULL);	/* fnum */
6258 	if (n < 0)
6259 	    return FAIL;
6260 	if (n == 0)
6261 	    n = curbuf->b_fnum;		/* current buffer */
6262 	*fnump = n;
6263     }
6264 
6265     n = list_find_nr(l, i++, NULL);	/* lnum */
6266     if (n < 0)
6267 	return FAIL;
6268     posp->lnum = n;
6269 
6270     n = list_find_nr(l, i++, NULL);	/* col */
6271     if (n < 0)
6272 	return FAIL;
6273     posp->col = n;
6274 
6275 #ifdef FEAT_VIRTUALEDIT
6276     n = list_find_nr(l, i, NULL);	/* off */
6277     if (n < 0)
6278 	posp->coladd = 0;
6279     else
6280 	posp->coladd = n;
6281 #endif
6282 
6283     if (curswantp != NULL)
6284 	*curswantp = list_find_nr(l, i + 1, NULL);  /* curswant */
6285 
6286     return OK;
6287 }
6288 
6289 /*
6290  * Get the length of an environment variable name.
6291  * Advance "arg" to the first character after the name.
6292  * Return 0 for error.
6293  */
6294     static int
6295 get_env_len(char_u **arg)
6296 {
6297     char_u	*p;
6298     int		len;
6299 
6300     for (p = *arg; vim_isIDc(*p); ++p)
6301 	;
6302     if (p == *arg)	    /* no name found */
6303 	return 0;
6304 
6305     len = (int)(p - *arg);
6306     *arg = p;
6307     return len;
6308 }
6309 
6310 /*
6311  * Get the length of the name of a function or internal variable.
6312  * "arg" is advanced to the first non-white character after the name.
6313  * Return 0 if something is wrong.
6314  */
6315     int
6316 get_id_len(char_u **arg)
6317 {
6318     char_u	*p;
6319     int		len;
6320 
6321     /* Find the end of the name. */
6322     for (p = *arg; eval_isnamec(*p); ++p)
6323     {
6324 	if (*p == ':')
6325 	{
6326 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6327 	     * slice "[n:]".  Also "xx:" is not a namespace. */
6328 	    len = (int)(p - *arg);
6329 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
6330 		    || len > 1)
6331 		break;
6332 	}
6333     }
6334     if (p == *arg)	    /* no name found */
6335 	return 0;
6336 
6337     len = (int)(p - *arg);
6338     *arg = skipwhite(p);
6339 
6340     return len;
6341 }
6342 
6343 /*
6344  * Get the length of the name of a variable or function.
6345  * Only the name is recognized, does not handle ".key" or "[idx]".
6346  * "arg" is advanced to the first non-white character after the name.
6347  * Return -1 if curly braces expansion failed.
6348  * Return 0 if something else is wrong.
6349  * If the name contains 'magic' {}'s, expand them and return the
6350  * expanded name in an allocated string via 'alias' - caller must free.
6351  */
6352     int
6353 get_name_len(
6354     char_u	**arg,
6355     char_u	**alias,
6356     int		evaluate,
6357     int		verbose)
6358 {
6359     int		len;
6360     char_u	*p;
6361     char_u	*expr_start;
6362     char_u	*expr_end;
6363 
6364     *alias = NULL;  /* default to no alias */
6365 
6366     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
6367 						  && (*arg)[2] == (int)KE_SNR)
6368     {
6369 	/* hard coded <SNR>, already translated */
6370 	*arg += 3;
6371 	return get_id_len(arg) + 3;
6372     }
6373     len = eval_fname_script(*arg);
6374     if (len > 0)
6375     {
6376 	/* literal "<SID>", "s:" or "<SNR>" */
6377 	*arg += len;
6378     }
6379 
6380     /*
6381      * Find the end of the name; check for {} construction.
6382      */
6383     p = find_name_end(*arg, &expr_start, &expr_end,
6384 					       len > 0 ? 0 : FNE_CHECK_START);
6385     if (expr_start != NULL)
6386     {
6387 	char_u	*temp_string;
6388 
6389 	if (!evaluate)
6390 	{
6391 	    len += (int)(p - *arg);
6392 	    *arg = skipwhite(p);
6393 	    return len;
6394 	}
6395 
6396 	/*
6397 	 * Include any <SID> etc in the expanded string:
6398 	 * Thus the -len here.
6399 	 */
6400 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
6401 	if (temp_string == NULL)
6402 	    return -1;
6403 	*alias = temp_string;
6404 	*arg = skipwhite(p);
6405 	return (int)STRLEN(temp_string);
6406     }
6407 
6408     len += get_id_len(arg);
6409     if (len == 0 && verbose)
6410 	EMSG2(_(e_invexpr2), *arg);
6411 
6412     return len;
6413 }
6414 
6415 /*
6416  * Find the end of a variable or function name, taking care of magic braces.
6417  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
6418  * start and end of the first magic braces item.
6419  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
6420  * Return a pointer to just after the name.  Equal to "arg" if there is no
6421  * valid name.
6422  */
6423     char_u *
6424 find_name_end(
6425     char_u	*arg,
6426     char_u	**expr_start,
6427     char_u	**expr_end,
6428     int		flags)
6429 {
6430     int		mb_nest = 0;
6431     int		br_nest = 0;
6432     char_u	*p;
6433     int		len;
6434 
6435     if (expr_start != NULL)
6436     {
6437 	*expr_start = NULL;
6438 	*expr_end = NULL;
6439     }
6440 
6441     /* Quick check for valid starting character. */
6442     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg) && *arg != '{')
6443 	return arg;
6444 
6445     for (p = arg; *p != NUL
6446 		    && (eval_isnamec(*p)
6447 			|| *p == '{'
6448 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
6449 			|| mb_nest != 0
6450 			|| br_nest != 0); MB_PTR_ADV(p))
6451     {
6452 	if (*p == '\'')
6453 	{
6454 	    /* skip over 'string' to avoid counting [ and ] inside it. */
6455 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
6456 		;
6457 	    if (*p == NUL)
6458 		break;
6459 	}
6460 	else if (*p == '"')
6461 	{
6462 	    /* skip over "str\"ing" to avoid counting [ and ] inside it. */
6463 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
6464 		if (*p == '\\' && p[1] != NUL)
6465 		    ++p;
6466 	    if (*p == NUL)
6467 		break;
6468 	}
6469 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
6470 	{
6471 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
6472 	     * slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is. */
6473 	    len = (int)(p - arg);
6474 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
6475 		    || (len > 1 && p[-1] != '}'))
6476 		break;
6477 	}
6478 
6479 	if (mb_nest == 0)
6480 	{
6481 	    if (*p == '[')
6482 		++br_nest;
6483 	    else if (*p == ']')
6484 		--br_nest;
6485 	}
6486 
6487 	if (br_nest == 0)
6488 	{
6489 	    if (*p == '{')
6490 	    {
6491 		mb_nest++;
6492 		if (expr_start != NULL && *expr_start == NULL)
6493 		    *expr_start = p;
6494 	    }
6495 	    else if (*p == '}')
6496 	    {
6497 		mb_nest--;
6498 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
6499 		    *expr_end = p;
6500 	    }
6501 	}
6502     }
6503 
6504     return p;
6505 }
6506 
6507 /*
6508  * Expands out the 'magic' {}'s in a variable/function name.
6509  * Note that this can call itself recursively, to deal with
6510  * constructs like foo{bar}{baz}{bam}
6511  * The four pointer arguments point to "foo{expre}ss{ion}bar"
6512  *			"in_start"      ^
6513  *			"expr_start"	   ^
6514  *			"expr_end"		 ^
6515  *			"in_end"			    ^
6516  *
6517  * Returns a new allocated string, which the caller must free.
6518  * Returns NULL for failure.
6519  */
6520     static char_u *
6521 make_expanded_name(
6522     char_u	*in_start,
6523     char_u	*expr_start,
6524     char_u	*expr_end,
6525     char_u	*in_end)
6526 {
6527     char_u	c1;
6528     char_u	*retval = NULL;
6529     char_u	*temp_result;
6530     char_u	*nextcmd = NULL;
6531 
6532     if (expr_end == NULL || in_end == NULL)
6533 	return NULL;
6534     *expr_start	= NUL;
6535     *expr_end = NUL;
6536     c1 = *in_end;
6537     *in_end = NUL;
6538 
6539     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
6540     if (temp_result != NULL && nextcmd == NULL)
6541     {
6542 	retval = alloc((unsigned)(STRLEN(temp_result) + (expr_start - in_start)
6543 						   + (in_end - expr_end) + 1));
6544 	if (retval != NULL)
6545 	{
6546 	    STRCPY(retval, in_start);
6547 	    STRCAT(retval, temp_result);
6548 	    STRCAT(retval, expr_end + 1);
6549 	}
6550     }
6551     vim_free(temp_result);
6552 
6553     *in_end = c1;		/* put char back for error messages */
6554     *expr_start = '{';
6555     *expr_end = '}';
6556 
6557     if (retval != NULL)
6558     {
6559 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
6560 	if (expr_start != NULL)
6561 	{
6562 	    /* Further expansion! */
6563 	    temp_result = make_expanded_name(retval, expr_start,
6564 						       expr_end, temp_result);
6565 	    vim_free(retval);
6566 	    retval = temp_result;
6567 	}
6568     }
6569 
6570     return retval;
6571 }
6572 
6573 /*
6574  * Return TRUE if character "c" can be used in a variable or function name.
6575  * Does not include '{' or '}' for magic braces.
6576  */
6577     int
6578 eval_isnamec(int c)
6579 {
6580     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
6581 }
6582 
6583 /*
6584  * Return TRUE if character "c" can be used as the first character in a
6585  * variable or function name (excluding '{' and '}').
6586  */
6587     int
6588 eval_isnamec1(int c)
6589 {
6590     return (ASCII_ISALPHA(c) || c == '_');
6591 }
6592 
6593 /*
6594  * Set number v: variable to "val".
6595  */
6596     void
6597 set_vim_var_nr(int idx, varnumber_T val)
6598 {
6599     vimvars[idx].vv_nr = val;
6600 }
6601 
6602 /*
6603  * Get number v: variable value.
6604  */
6605     varnumber_T
6606 get_vim_var_nr(int idx)
6607 {
6608     return vimvars[idx].vv_nr;
6609 }
6610 
6611 /*
6612  * Get string v: variable value.  Uses a static buffer, can only be used once.
6613  */
6614     char_u *
6615 get_vim_var_str(int idx)
6616 {
6617     return get_tv_string(&vimvars[idx].vv_tv);
6618 }
6619 
6620 /*
6621  * Get List v: variable value.  Caller must take care of reference count when
6622  * needed.
6623  */
6624     list_T *
6625 get_vim_var_list(int idx)
6626 {
6627     return vimvars[idx].vv_list;
6628 }
6629 
6630 /*
6631  * Set v:char to character "c".
6632  */
6633     void
6634 set_vim_var_char(int c)
6635 {
6636     char_u	buf[MB_MAXBYTES + 1];
6637 
6638 #ifdef FEAT_MBYTE
6639     if (has_mbyte)
6640 	buf[(*mb_char2bytes)(c, buf)] = NUL;
6641     else
6642 #endif
6643     {
6644 	buf[0] = c;
6645 	buf[1] = NUL;
6646     }
6647     set_vim_var_string(VV_CHAR, buf, -1);
6648 }
6649 
6650 /*
6651  * Set v:count to "count" and v:count1 to "count1".
6652  * When "set_prevcount" is TRUE first set v:prevcount from v:count.
6653  */
6654     void
6655 set_vcount(
6656     long	count,
6657     long	count1,
6658     int		set_prevcount)
6659 {
6660     if (set_prevcount)
6661 	vimvars[VV_PREVCOUNT].vv_nr = vimvars[VV_COUNT].vv_nr;
6662     vimvars[VV_COUNT].vv_nr = count;
6663     vimvars[VV_COUNT1].vv_nr = count1;
6664 }
6665 
6666 /*
6667  * Set string v: variable to a copy of "val".
6668  */
6669     void
6670 set_vim_var_string(
6671     int		idx,
6672     char_u	*val,
6673     int		len)	    /* length of "val" to use or -1 (whole string) */
6674 {
6675     clear_tv(&vimvars[idx].vv_di.di_tv);
6676     vimvars[idx].vv_type = VAR_STRING;
6677     if (val == NULL)
6678 	vimvars[idx].vv_str = NULL;
6679     else if (len == -1)
6680 	vimvars[idx].vv_str = vim_strsave(val);
6681     else
6682 	vimvars[idx].vv_str = vim_strnsave(val, len);
6683 }
6684 
6685 /*
6686  * Set List v: variable to "val".
6687  */
6688     void
6689 set_vim_var_list(int idx, list_T *val)
6690 {
6691     clear_tv(&vimvars[idx].vv_di.di_tv);
6692     vimvars[idx].vv_type = VAR_LIST;
6693     vimvars[idx].vv_list = val;
6694     if (val != NULL)
6695 	++val->lv_refcount;
6696 }
6697 
6698 /*
6699  * Set Dictionary v: variable to "val".
6700  */
6701     void
6702 set_vim_var_dict(int idx, dict_T *val)
6703 {
6704     int		todo;
6705     hashitem_T	*hi;
6706 
6707     clear_tv(&vimvars[idx].vv_di.di_tv);
6708     vimvars[idx].vv_type = VAR_DICT;
6709     vimvars[idx].vv_dict = val;
6710     if (val != NULL)
6711     {
6712 	++val->dv_refcount;
6713 
6714 	/* Set readonly */
6715 	todo = (int)val->dv_hashtab.ht_used;
6716 	for (hi = val->dv_hashtab.ht_array; todo > 0 ; ++hi)
6717 	{
6718 	    if (HASHITEM_EMPTY(hi))
6719 		continue;
6720 	    --todo;
6721 	    HI2DI(hi)->di_flags |= DI_FLAGS_RO | DI_FLAGS_FIX;
6722 	}
6723     }
6724 }
6725 
6726 /*
6727  * Set v:register if needed.
6728  */
6729     void
6730 set_reg_var(int c)
6731 {
6732     char_u	regname;
6733 
6734     if (c == 0 || c == ' ')
6735 	regname = '"';
6736     else
6737 	regname = c;
6738     /* Avoid free/alloc when the value is already right. */
6739     if (vimvars[VV_REG].vv_str == NULL || vimvars[VV_REG].vv_str[0] != c)
6740 	set_vim_var_string(VV_REG, &regname, 1);
6741 }
6742 
6743 /*
6744  * Get or set v:exception.  If "oldval" == NULL, return the current value.
6745  * Otherwise, restore the value to "oldval" and return NULL.
6746  * Must always be called in pairs to save and restore v:exception!  Does not
6747  * take care of memory allocations.
6748  */
6749     char_u *
6750 v_exception(char_u *oldval)
6751 {
6752     if (oldval == NULL)
6753 	return vimvars[VV_EXCEPTION].vv_str;
6754 
6755     vimvars[VV_EXCEPTION].vv_str = oldval;
6756     return NULL;
6757 }
6758 
6759 /*
6760  * Get or set v:throwpoint.  If "oldval" == NULL, return the current value.
6761  * Otherwise, restore the value to "oldval" and return NULL.
6762  * Must always be called in pairs to save and restore v:throwpoint!  Does not
6763  * take care of memory allocations.
6764  */
6765     char_u *
6766 v_throwpoint(char_u *oldval)
6767 {
6768     if (oldval == NULL)
6769 	return vimvars[VV_THROWPOINT].vv_str;
6770 
6771     vimvars[VV_THROWPOINT].vv_str = oldval;
6772     return NULL;
6773 }
6774 
6775 #if defined(FEAT_AUTOCMD) || defined(PROTO)
6776 /*
6777  * Set v:cmdarg.
6778  * If "eap" != NULL, use "eap" to generate the value and return the old value.
6779  * If "oldarg" != NULL, restore the value to "oldarg" and return NULL.
6780  * Must always be called in pairs!
6781  */
6782     char_u *
6783 set_cmdarg(exarg_T *eap, char_u *oldarg)
6784 {
6785     char_u	*oldval;
6786     char_u	*newval;
6787     unsigned	len;
6788 
6789     oldval = vimvars[VV_CMDARG].vv_str;
6790     if (eap == NULL)
6791     {
6792 	vim_free(oldval);
6793 	vimvars[VV_CMDARG].vv_str = oldarg;
6794 	return NULL;
6795     }
6796 
6797     if (eap->force_bin == FORCE_BIN)
6798 	len = 6;
6799     else if (eap->force_bin == FORCE_NOBIN)
6800 	len = 8;
6801     else
6802 	len = 0;
6803 
6804     if (eap->read_edit)
6805 	len += 7;
6806 
6807     if (eap->force_ff != 0)
6808 	len += (unsigned)STRLEN(eap->cmd + eap->force_ff) + 6;
6809 # ifdef FEAT_MBYTE
6810     if (eap->force_enc != 0)
6811 	len += (unsigned)STRLEN(eap->cmd + eap->force_enc) + 7;
6812     if (eap->bad_char != 0)
6813 	len += 7 + 4;  /* " ++bad=" + "keep" or "drop" */
6814 # endif
6815 
6816     newval = alloc(len + 1);
6817     if (newval == NULL)
6818 	return NULL;
6819 
6820     if (eap->force_bin == FORCE_BIN)
6821 	sprintf((char *)newval, " ++bin");
6822     else if (eap->force_bin == FORCE_NOBIN)
6823 	sprintf((char *)newval, " ++nobin");
6824     else
6825 	*newval = NUL;
6826 
6827     if (eap->read_edit)
6828 	STRCAT(newval, " ++edit");
6829 
6830     if (eap->force_ff != 0)
6831 	sprintf((char *)newval + STRLEN(newval), " ++ff=%s",
6832 						eap->cmd + eap->force_ff);
6833 # ifdef FEAT_MBYTE
6834     if (eap->force_enc != 0)
6835 	sprintf((char *)newval + STRLEN(newval), " ++enc=%s",
6836 					       eap->cmd + eap->force_enc);
6837     if (eap->bad_char == BAD_KEEP)
6838 	STRCPY(newval + STRLEN(newval), " ++bad=keep");
6839     else if (eap->bad_char == BAD_DROP)
6840 	STRCPY(newval + STRLEN(newval), " ++bad=drop");
6841     else if (eap->bad_char != 0)
6842 	sprintf((char *)newval + STRLEN(newval), " ++bad=%c", eap->bad_char);
6843 # endif
6844     vimvars[VV_CMDARG].vv_str = newval;
6845     return oldval;
6846 }
6847 #endif
6848 
6849 /*
6850  * Get the value of internal variable "name".
6851  * Return OK or FAIL.
6852  */
6853     int
6854 get_var_tv(
6855     char_u	*name,
6856     int		len,		/* length of "name" */
6857     typval_T	*rettv,		/* NULL when only checking existence */
6858     dictitem_T	**dip,		/* non-NULL when typval's dict item is needed */
6859     int		verbose,	/* may give error message */
6860     int		no_autoload)	/* do not use script autoloading */
6861 {
6862     int		ret = OK;
6863     typval_T	*tv = NULL;
6864     dictitem_T	*v;
6865     int		cc;
6866 
6867     /* truncate the name, so that we can use strcmp() */
6868     cc = name[len];
6869     name[len] = NUL;
6870 
6871     /*
6872      * Check for user-defined variables.
6873      */
6874     v = find_var(name, NULL, no_autoload);
6875     if (v != NULL)
6876     {
6877 	tv = &v->di_tv;
6878 	if (dip != NULL)
6879 	    *dip = v;
6880     }
6881 
6882     if (tv == NULL)
6883     {
6884 	if (rettv != NULL && verbose)
6885 	    EMSG2(_(e_undefvar), name);
6886 	ret = FAIL;
6887     }
6888     else if (rettv != NULL)
6889 	copy_tv(tv, rettv);
6890 
6891     name[len] = cc;
6892 
6893     return ret;
6894 }
6895 
6896 /*
6897  * Check if variable "name[len]" is a local variable or an argument.
6898  * If so, "*eval_lavars_used" is set to TRUE.
6899  */
6900     static void
6901 check_vars(char_u *name, int len)
6902 {
6903     int		cc;
6904     char_u	*varname;
6905     hashtab_T	*ht;
6906 
6907     if (eval_lavars_used == NULL)
6908 	return;
6909 
6910     /* truncate the name, so that we can use strcmp() */
6911     cc = name[len];
6912     name[len] = NUL;
6913 
6914     ht = find_var_ht(name, &varname);
6915     if (ht == get_funccal_local_ht() || ht == get_funccal_args_ht())
6916     {
6917 	if (find_var(name, NULL, TRUE) != NULL)
6918 	    *eval_lavars_used = TRUE;
6919     }
6920 
6921     name[len] = cc;
6922 }
6923 
6924 /*
6925  * Handle expr[expr], expr[expr:expr] subscript and .name lookup.
6926  * Also handle function call with Funcref variable: func(expr)
6927  * Can all be combined: dict.func(expr)[idx]['func'](expr)
6928  */
6929     int
6930 handle_subscript(
6931     char_u	**arg,
6932     typval_T	*rettv,
6933     int		evaluate,	/* do more than finding the end */
6934     int		verbose)	/* give error messages */
6935 {
6936     int		ret = OK;
6937     dict_T	*selfdict = NULL;
6938     char_u	*s;
6939     int		len;
6940     typval_T	functv;
6941 
6942     while (ret == OK
6943 	    && (**arg == '['
6944 		|| (**arg == '.' && rettv->v_type == VAR_DICT)
6945 		|| (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
6946 					    || rettv->v_type == VAR_PARTIAL)))
6947 	    && !VIM_ISWHITE(*(*arg - 1)))
6948     {
6949 	if (**arg == '(')
6950 	{
6951 	    partial_T	*pt = NULL;
6952 
6953 	    /* need to copy the funcref so that we can clear rettv */
6954 	    if (evaluate)
6955 	    {
6956 		functv = *rettv;
6957 		rettv->v_type = VAR_UNKNOWN;
6958 
6959 		/* Invoke the function.  Recursive! */
6960 		if (functv.v_type == VAR_PARTIAL)
6961 		{
6962 		    pt = functv.vval.v_partial;
6963 		    s = partial_name(pt);
6964 		}
6965 		else
6966 		    s = functv.vval.v_string;
6967 	    }
6968 	    else
6969 		s = (char_u *)"";
6970 	    ret = get_func_tv(s, (int)STRLEN(s), rettv, arg,
6971 			curwin->w_cursor.lnum, curwin->w_cursor.lnum,
6972 			&len, evaluate, pt, selfdict);
6973 
6974 	    /* Clear the funcref afterwards, so that deleting it while
6975 	     * evaluating the arguments is possible (see test55). */
6976 	    if (evaluate)
6977 		clear_tv(&functv);
6978 
6979 	    /* Stop the expression evaluation when immediately aborting on
6980 	     * error, or when an interrupt occurred or an exception was thrown
6981 	     * but not caught. */
6982 	    if (aborting())
6983 	    {
6984 		if (ret == OK)
6985 		    clear_tv(rettv);
6986 		ret = FAIL;
6987 	    }
6988 	    dict_unref(selfdict);
6989 	    selfdict = NULL;
6990 	}
6991 	else /* **arg == '[' || **arg == '.' */
6992 	{
6993 	    dict_unref(selfdict);
6994 	    if (rettv->v_type == VAR_DICT)
6995 	    {
6996 		selfdict = rettv->vval.v_dict;
6997 		if (selfdict != NULL)
6998 		    ++selfdict->dv_refcount;
6999 	    }
7000 	    else
7001 		selfdict = NULL;
7002 	    if (eval_index(arg, rettv, evaluate, verbose) == FAIL)
7003 	    {
7004 		clear_tv(rettv);
7005 		ret = FAIL;
7006 	    }
7007 	}
7008     }
7009 
7010     /* Turn "dict.Func" into a partial for "Func" bound to "dict".
7011      * Don't do this when "Func" is already a partial that was bound
7012      * explicitly (pt_auto is FALSE). */
7013     if (selfdict != NULL
7014 	    && (rettv->v_type == VAR_FUNC
7015 		|| (rettv->v_type == VAR_PARTIAL
7016 		    && (rettv->vval.v_partial->pt_auto
7017 			|| rettv->vval.v_partial->pt_dict == NULL))))
7018 	selfdict = make_partial(selfdict, rettv);
7019 
7020     dict_unref(selfdict);
7021     return ret;
7022 }
7023 
7024 /*
7025  * Allocate memory for a variable type-value, and make it empty (0 or NULL
7026  * value).
7027  */
7028     typval_T *
7029 alloc_tv(void)
7030 {
7031     return (typval_T *)alloc_clear((unsigned)sizeof(typval_T));
7032 }
7033 
7034 /*
7035  * Allocate memory for a variable type-value, and assign a string to it.
7036  * The string "s" must have been allocated, it is consumed.
7037  * Return NULL for out of memory, the variable otherwise.
7038  */
7039     static typval_T *
7040 alloc_string_tv(char_u *s)
7041 {
7042     typval_T	*rettv;
7043 
7044     rettv = alloc_tv();
7045     if (rettv != NULL)
7046     {
7047 	rettv->v_type = VAR_STRING;
7048 	rettv->vval.v_string = s;
7049     }
7050     else
7051 	vim_free(s);
7052     return rettv;
7053 }
7054 
7055 /*
7056  * Free the memory for a variable type-value.
7057  */
7058     void
7059 free_tv(typval_T *varp)
7060 {
7061     if (varp != NULL)
7062     {
7063 	switch (varp->v_type)
7064 	{
7065 	    case VAR_FUNC:
7066 		func_unref(varp->vval.v_string);
7067 		/* FALLTHROUGH */
7068 	    case VAR_STRING:
7069 		vim_free(varp->vval.v_string);
7070 		break;
7071 	    case VAR_PARTIAL:
7072 		partial_unref(varp->vval.v_partial);
7073 		break;
7074 	    case VAR_LIST:
7075 		list_unref(varp->vval.v_list);
7076 		break;
7077 	    case VAR_DICT:
7078 		dict_unref(varp->vval.v_dict);
7079 		break;
7080 	    case VAR_JOB:
7081 #ifdef FEAT_JOB_CHANNEL
7082 		job_unref(varp->vval.v_job);
7083 		break;
7084 #endif
7085 	    case VAR_CHANNEL:
7086 #ifdef FEAT_JOB_CHANNEL
7087 		channel_unref(varp->vval.v_channel);
7088 		break;
7089 #endif
7090 	    case VAR_NUMBER:
7091 	    case VAR_FLOAT:
7092 	    case VAR_UNKNOWN:
7093 	    case VAR_SPECIAL:
7094 		break;
7095 	}
7096 	vim_free(varp);
7097     }
7098 }
7099 
7100 /*
7101  * Free the memory for a variable value and set the value to NULL or 0.
7102  */
7103     void
7104 clear_tv(typval_T *varp)
7105 {
7106     if (varp != NULL)
7107     {
7108 	switch (varp->v_type)
7109 	{
7110 	    case VAR_FUNC:
7111 		func_unref(varp->vval.v_string);
7112 		/* FALLTHROUGH */
7113 	    case VAR_STRING:
7114 		vim_free(varp->vval.v_string);
7115 		varp->vval.v_string = NULL;
7116 		break;
7117 	    case VAR_PARTIAL:
7118 		partial_unref(varp->vval.v_partial);
7119 		varp->vval.v_partial = NULL;
7120 		break;
7121 	    case VAR_LIST:
7122 		list_unref(varp->vval.v_list);
7123 		varp->vval.v_list = NULL;
7124 		break;
7125 	    case VAR_DICT:
7126 		dict_unref(varp->vval.v_dict);
7127 		varp->vval.v_dict = NULL;
7128 		break;
7129 	    case VAR_NUMBER:
7130 	    case VAR_SPECIAL:
7131 		varp->vval.v_number = 0;
7132 		break;
7133 	    case VAR_FLOAT:
7134 #ifdef FEAT_FLOAT
7135 		varp->vval.v_float = 0.0;
7136 		break;
7137 #endif
7138 	    case VAR_JOB:
7139 #ifdef FEAT_JOB_CHANNEL
7140 		job_unref(varp->vval.v_job);
7141 		varp->vval.v_job = NULL;
7142 #endif
7143 		break;
7144 	    case VAR_CHANNEL:
7145 #ifdef FEAT_JOB_CHANNEL
7146 		channel_unref(varp->vval.v_channel);
7147 		varp->vval.v_channel = NULL;
7148 #endif
7149 	    case VAR_UNKNOWN:
7150 		break;
7151 	}
7152 	varp->v_lock = 0;
7153     }
7154 }
7155 
7156 /*
7157  * Set the value of a variable to NULL without freeing items.
7158  */
7159     void
7160 init_tv(typval_T *varp)
7161 {
7162     if (varp != NULL)
7163 	vim_memset(varp, 0, sizeof(typval_T));
7164 }
7165 
7166 /*
7167  * Get the number value of a variable.
7168  * If it is a String variable, uses vim_str2nr().
7169  * For incompatible types, return 0.
7170  * get_tv_number_chk() is similar to get_tv_number(), but informs the
7171  * caller of incompatible types: it sets *denote to TRUE if "denote"
7172  * is not NULL or returns -1 otherwise.
7173  */
7174     varnumber_T
7175 get_tv_number(typval_T *varp)
7176 {
7177     int		error = FALSE;
7178 
7179     return get_tv_number_chk(varp, &error);	/* return 0L on error */
7180 }
7181 
7182     varnumber_T
7183 get_tv_number_chk(typval_T *varp, int *denote)
7184 {
7185     varnumber_T	n = 0L;
7186 
7187     switch (varp->v_type)
7188     {
7189 	case VAR_NUMBER:
7190 	    return varp->vval.v_number;
7191 	case VAR_FLOAT:
7192 #ifdef FEAT_FLOAT
7193 	    EMSG(_("E805: Using a Float as a Number"));
7194 	    break;
7195 #endif
7196 	case VAR_FUNC:
7197 	case VAR_PARTIAL:
7198 	    EMSG(_("E703: Using a Funcref as a Number"));
7199 	    break;
7200 	case VAR_STRING:
7201 	    if (varp->vval.v_string != NULL)
7202 		vim_str2nr(varp->vval.v_string, NULL, NULL,
7203 						    STR2NR_ALL, &n, NULL, 0);
7204 	    return n;
7205 	case VAR_LIST:
7206 	    EMSG(_("E745: Using a List as a Number"));
7207 	    break;
7208 	case VAR_DICT:
7209 	    EMSG(_("E728: Using a Dictionary as a Number"));
7210 	    break;
7211 	case VAR_SPECIAL:
7212 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
7213 	    break;
7214 	case VAR_JOB:
7215 #ifdef FEAT_JOB_CHANNEL
7216 	    EMSG(_("E910: Using a Job as a Number"));
7217 	    break;
7218 #endif
7219 	case VAR_CHANNEL:
7220 #ifdef FEAT_JOB_CHANNEL
7221 	    EMSG(_("E913: Using a Channel as a Number"));
7222 	    break;
7223 #endif
7224 	case VAR_UNKNOWN:
7225 	    internal_error("get_tv_number(UNKNOWN)");
7226 	    break;
7227     }
7228     if (denote == NULL)		/* useful for values that must be unsigned */
7229 	n = -1;
7230     else
7231 	*denote = TRUE;
7232     return n;
7233 }
7234 
7235 #ifdef FEAT_FLOAT
7236     float_T
7237 get_tv_float(typval_T *varp)
7238 {
7239     switch (varp->v_type)
7240     {
7241 	case VAR_NUMBER:
7242 	    return (float_T)(varp->vval.v_number);
7243 	case VAR_FLOAT:
7244 	    return varp->vval.v_float;
7245 	case VAR_FUNC:
7246 	case VAR_PARTIAL:
7247 	    EMSG(_("E891: Using a Funcref as a Float"));
7248 	    break;
7249 	case VAR_STRING:
7250 	    EMSG(_("E892: Using a String as a Float"));
7251 	    break;
7252 	case VAR_LIST:
7253 	    EMSG(_("E893: Using a List as a Float"));
7254 	    break;
7255 	case VAR_DICT:
7256 	    EMSG(_("E894: Using a Dictionary as a Float"));
7257 	    break;
7258 	case VAR_SPECIAL:
7259 	    EMSG(_("E907: Using a special value as a Float"));
7260 	    break;
7261 	case VAR_JOB:
7262 # ifdef FEAT_JOB_CHANNEL
7263 	    EMSG(_("E911: Using a Job as a Float"));
7264 	    break;
7265 # endif
7266 	case VAR_CHANNEL:
7267 # ifdef FEAT_JOB_CHANNEL
7268 	    EMSG(_("E914: Using a Channel as a Float"));
7269 	    break;
7270 # endif
7271 	case VAR_UNKNOWN:
7272 	    internal_error("get_tv_float(UNKNOWN)");
7273 	    break;
7274     }
7275     return 0;
7276 }
7277 #endif
7278 
7279 /*
7280  * Get the string value of a variable.
7281  * If it is a Number variable, the number is converted into a string.
7282  * get_tv_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7283  * get_tv_string_buf() uses a given buffer.
7284  * If the String variable has never been set, return an empty string.
7285  * Never returns NULL;
7286  * get_tv_string_chk() and get_tv_string_buf_chk() are similar, but return
7287  * NULL on error.
7288  */
7289     char_u *
7290 get_tv_string(typval_T *varp)
7291 {
7292     static char_u   mybuf[NUMBUFLEN];
7293 
7294     return get_tv_string_buf(varp, mybuf);
7295 }
7296 
7297     char_u *
7298 get_tv_string_buf(typval_T *varp, char_u *buf)
7299 {
7300     char_u	*res =  get_tv_string_buf_chk(varp, buf);
7301 
7302     return res != NULL ? res : (char_u *)"";
7303 }
7304 
7305 /*
7306  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
7307  */
7308     char_u *
7309 get_tv_string_chk(typval_T *varp)
7310 {
7311     static char_u   mybuf[NUMBUFLEN];
7312 
7313     return get_tv_string_buf_chk(varp, mybuf);
7314 }
7315 
7316     char_u *
7317 get_tv_string_buf_chk(typval_T *varp, char_u *buf)
7318 {
7319     switch (varp->v_type)
7320     {
7321 	case VAR_NUMBER:
7322 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
7323 					    (varnumber_T)varp->vval.v_number);
7324 	    return buf;
7325 	case VAR_FUNC:
7326 	case VAR_PARTIAL:
7327 	    EMSG(_("E729: using Funcref as a String"));
7328 	    break;
7329 	case VAR_LIST:
7330 	    EMSG(_("E730: using List as a String"));
7331 	    break;
7332 	case VAR_DICT:
7333 	    EMSG(_("E731: using Dictionary as a String"));
7334 	    break;
7335 	case VAR_FLOAT:
7336 #ifdef FEAT_FLOAT
7337 	    EMSG(_(e_float_as_string));
7338 	    break;
7339 #endif
7340 	case VAR_STRING:
7341 	    if (varp->vval.v_string != NULL)
7342 		return varp->vval.v_string;
7343 	    return (char_u *)"";
7344 	case VAR_SPECIAL:
7345 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
7346 	    return buf;
7347 	case VAR_JOB:
7348 #ifdef FEAT_JOB_CHANNEL
7349 	    {
7350 		job_T *job = varp->vval.v_job;
7351 		char  *status;
7352 
7353 		if (job == NULL)
7354 		    return (char_u *)"no process";
7355 		status = job->jv_status == JOB_FAILED ? "fail"
7356 				: job->jv_status >= JOB_ENDED ? "dead"
7357 				: "run";
7358 # ifdef UNIX
7359 		vim_snprintf((char *)buf, NUMBUFLEN,
7360 			    "process %ld %s", (long)job->jv_pid, status);
7361 # elif defined(WIN32)
7362 		vim_snprintf((char *)buf, NUMBUFLEN,
7363 			    "process %ld %s",
7364 			    (long)job->jv_proc_info.dwProcessId,
7365 			    status);
7366 # else
7367 		/* fall-back */
7368 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
7369 # endif
7370 		return buf;
7371 	    }
7372 #endif
7373 	    break;
7374 	case VAR_CHANNEL:
7375 #ifdef FEAT_JOB_CHANNEL
7376 	    {
7377 		channel_T *channel = varp->vval.v_channel;
7378 		char      *status = channel_status(channel, -1);
7379 
7380 		if (channel == NULL)
7381 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
7382 		else
7383 		    vim_snprintf((char *)buf, NUMBUFLEN,
7384 				     "channel %d %s", channel->ch_id, status);
7385 		return buf;
7386 	    }
7387 #endif
7388 	    break;
7389 	case VAR_UNKNOWN:
7390 	    EMSG(_("E908: using an invalid value as a String"));
7391 	    break;
7392     }
7393     return NULL;
7394 }
7395 
7396 /*
7397  * Find variable "name" in the list of variables.
7398  * Return a pointer to it if found, NULL if not found.
7399  * Careful: "a:0" variables don't have a name.
7400  * When "htp" is not NULL we are writing to the variable, set "htp" to the
7401  * hashtab_T used.
7402  */
7403     dictitem_T *
7404 find_var(char_u *name, hashtab_T **htp, int no_autoload)
7405 {
7406     char_u	*varname;
7407     hashtab_T	*ht;
7408     dictitem_T	*ret = NULL;
7409 
7410     ht = find_var_ht(name, &varname);
7411     if (htp != NULL)
7412 	*htp = ht;
7413     if (ht == NULL)
7414 	return NULL;
7415     ret = find_var_in_ht(ht, *name, varname, no_autoload || htp != NULL);
7416     if (ret != NULL)
7417 	return ret;
7418 
7419     /* Search in parent scope for lambda */
7420     return find_var_in_scoped_ht(name, no_autoload || htp != NULL);
7421 }
7422 
7423 /*
7424  * Find variable "varname" in hashtab "ht" with name "htname".
7425  * Returns NULL if not found.
7426  */
7427     dictitem_T *
7428 find_var_in_ht(
7429     hashtab_T	*ht,
7430     int		htname,
7431     char_u	*varname,
7432     int		no_autoload)
7433 {
7434     hashitem_T	*hi;
7435 
7436     if (*varname == NUL)
7437     {
7438 	/* Must be something like "s:", otherwise "ht" would be NULL. */
7439 	switch (htname)
7440 	{
7441 	    case 's': return &SCRIPT_SV(current_SID)->sv_var;
7442 	    case 'g': return &globvars_var;
7443 	    case 'v': return &vimvars_var;
7444 	    case 'b': return &curbuf->b_bufvar;
7445 	    case 'w': return &curwin->w_winvar;
7446 	    case 't': return &curtab->tp_winvar;
7447 	    case 'l': return get_funccal_local_var();
7448 	    case 'a': return get_funccal_args_var();
7449 	}
7450 	return NULL;
7451     }
7452 
7453     hi = hash_find(ht, varname);
7454     if (HASHITEM_EMPTY(hi))
7455     {
7456 	/* For global variables we may try auto-loading the script.  If it
7457 	 * worked find the variable again.  Don't auto-load a script if it was
7458 	 * loaded already, otherwise it would be loaded every time when
7459 	 * checking if a function name is a Funcref variable. */
7460 	if (ht == &globvarht && !no_autoload)
7461 	{
7462 	    /* Note: script_autoload() may make "hi" invalid. It must either
7463 	     * be obtained again or not used. */
7464 	    if (!script_autoload(varname, FALSE) || aborting())
7465 		return NULL;
7466 	    hi = hash_find(ht, varname);
7467 	}
7468 	if (HASHITEM_EMPTY(hi))
7469 	    return NULL;
7470     }
7471     return HI2DI(hi);
7472 }
7473 
7474 /*
7475  * Find the hashtab used for a variable name.
7476  * Return NULL if the name is not valid.
7477  * Set "varname" to the start of name without ':'.
7478  */
7479     hashtab_T *
7480 find_var_ht(char_u *name, char_u **varname)
7481 {
7482     hashitem_T	*hi;
7483     hashtab_T	*ht;
7484 
7485     if (name[0] == NUL)
7486 	return NULL;
7487     if (name[1] != ':')
7488     {
7489 	/* The name must not start with a colon or #. */
7490 	if (name[0] == ':' || name[0] == AUTOLOAD_CHAR)
7491 	    return NULL;
7492 	*varname = name;
7493 
7494 	/* "version" is "v:version" in all scopes */
7495 	hi = hash_find(&compat_hashtab, name);
7496 	if (!HASHITEM_EMPTY(hi))
7497 	    return &compat_hashtab;
7498 
7499 	ht = get_funccal_local_ht();
7500 	if (ht == NULL)
7501 	    return &globvarht;			/* global variable */
7502 	return ht;				/* local variable */
7503     }
7504     *varname = name + 2;
7505     if (*name == 'g')				/* global variable */
7506 	return &globvarht;
7507     /* There must be no ':' or '#' in the rest of the name, unless g: is used
7508      */
7509     if (vim_strchr(name + 2, ':') != NULL
7510 			       || vim_strchr(name + 2, AUTOLOAD_CHAR) != NULL)
7511 	return NULL;
7512     if (*name == 'b')				/* buffer variable */
7513 	return &curbuf->b_vars->dv_hashtab;
7514     if (*name == 'w')				/* window variable */
7515 	return &curwin->w_vars->dv_hashtab;
7516     if (*name == 't')				/* tab page variable */
7517 	return &curtab->tp_vars->dv_hashtab;
7518     if (*name == 'v')				/* v: variable */
7519 	return &vimvarht;
7520     if (*name == 'a')				/* a: function argument */
7521 	return get_funccal_args_ht();
7522     if (*name == 'l')				/* l: local function variable */
7523 	return get_funccal_local_ht();
7524     if (*name == 's'				/* script variable */
7525 	    && current_SID > 0 && current_SID <= ga_scripts.ga_len)
7526 	return &SCRIPT_VARS(current_SID);
7527     return NULL;
7528 }
7529 
7530 /*
7531  * Get the string value of a (global/local) variable.
7532  * Note: see get_tv_string() for how long the pointer remains valid.
7533  * Returns NULL when it doesn't exist.
7534  */
7535     char_u *
7536 get_var_value(char_u *name)
7537 {
7538     dictitem_T	*v;
7539 
7540     v = find_var(name, NULL, FALSE);
7541     if (v == NULL)
7542 	return NULL;
7543     return get_tv_string(&v->di_tv);
7544 }
7545 
7546 /*
7547  * Allocate a new hashtab for a sourced script.  It will be used while
7548  * sourcing this script and when executing functions defined in the script.
7549  */
7550     void
7551 new_script_vars(scid_T id)
7552 {
7553     int		i;
7554     hashtab_T	*ht;
7555     scriptvar_T *sv;
7556 
7557     if (ga_grow(&ga_scripts, (int)(id - ga_scripts.ga_len)) == OK)
7558     {
7559 	/* Re-allocating ga_data means that an ht_array pointing to
7560 	 * ht_smallarray becomes invalid.  We can recognize this: ht_mask is
7561 	 * at its init value.  Also reset "v_dict", it's always the same. */
7562 	for (i = 1; i <= ga_scripts.ga_len; ++i)
7563 	{
7564 	    ht = &SCRIPT_VARS(i);
7565 	    if (ht->ht_mask == HT_INIT_SIZE - 1)
7566 		ht->ht_array = ht->ht_smallarray;
7567 	    sv = SCRIPT_SV(i);
7568 	    sv->sv_var.di_tv.vval.v_dict = &sv->sv_dict;
7569 	}
7570 
7571 	while (ga_scripts.ga_len < id)
7572 	{
7573 	    sv = SCRIPT_SV(ga_scripts.ga_len + 1) =
7574 		(scriptvar_T *)alloc_clear(sizeof(scriptvar_T));
7575 	    init_var_dict(&sv->sv_dict, &sv->sv_var, VAR_SCOPE);
7576 	    ++ga_scripts.ga_len;
7577 	}
7578     }
7579 }
7580 
7581 /*
7582  * Initialize dictionary "dict" as a scope and set variable "dict_var" to
7583  * point to it.
7584  */
7585     void
7586 init_var_dict(dict_T *dict, dictitem_T *dict_var, int scope)
7587 {
7588     hash_init(&dict->dv_hashtab);
7589     dict->dv_lock = 0;
7590     dict->dv_scope = scope;
7591     dict->dv_refcount = DO_NOT_FREE_CNT;
7592     dict->dv_copyID = 0;
7593     dict_var->di_tv.vval.v_dict = dict;
7594     dict_var->di_tv.v_type = VAR_DICT;
7595     dict_var->di_tv.v_lock = VAR_FIXED;
7596     dict_var->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
7597     dict_var->di_key[0] = NUL;
7598 }
7599 
7600 /*
7601  * Unreference a dictionary initialized by init_var_dict().
7602  */
7603     void
7604 unref_var_dict(dict_T *dict)
7605 {
7606     /* Now the dict needs to be freed if no one else is using it, go back to
7607      * normal reference counting. */
7608     dict->dv_refcount -= DO_NOT_FREE_CNT - 1;
7609     dict_unref(dict);
7610 }
7611 
7612 /*
7613  * Clean up a list of internal variables.
7614  * Frees all allocated variables and the value they contain.
7615  * Clears hashtab "ht", does not free it.
7616  */
7617     void
7618 vars_clear(hashtab_T *ht)
7619 {
7620     vars_clear_ext(ht, TRUE);
7621 }
7622 
7623 /*
7624  * Like vars_clear(), but only free the value if "free_val" is TRUE.
7625  */
7626     void
7627 vars_clear_ext(hashtab_T *ht, int free_val)
7628 {
7629     int		todo;
7630     hashitem_T	*hi;
7631     dictitem_T	*v;
7632 
7633     hash_lock(ht);
7634     todo = (int)ht->ht_used;
7635     for (hi = ht->ht_array; todo > 0; ++hi)
7636     {
7637 	if (!HASHITEM_EMPTY(hi))
7638 	{
7639 	    --todo;
7640 
7641 	    /* Free the variable.  Don't remove it from the hashtab,
7642 	     * ht_array might change then.  hash_clear() takes care of it
7643 	     * later. */
7644 	    v = HI2DI(hi);
7645 	    if (free_val)
7646 		clear_tv(&v->di_tv);
7647 	    if (v->di_flags & DI_FLAGS_ALLOC)
7648 		vim_free(v);
7649 	}
7650     }
7651     hash_clear(ht);
7652     ht->ht_used = 0;
7653 }
7654 
7655 /*
7656  * Delete a variable from hashtab "ht" at item "hi".
7657  * Clear the variable value and free the dictitem.
7658  */
7659     static void
7660 delete_var(hashtab_T *ht, hashitem_T *hi)
7661 {
7662     dictitem_T	*di = HI2DI(hi);
7663 
7664     hash_remove(ht, hi);
7665     clear_tv(&di->di_tv);
7666     vim_free(di);
7667 }
7668 
7669 /*
7670  * List the value of one internal variable.
7671  */
7672     static void
7673 list_one_var(dictitem_T *v, char_u *prefix, int *first)
7674 {
7675     char_u	*tofree;
7676     char_u	*s;
7677     char_u	numbuf[NUMBUFLEN];
7678 
7679     s = echo_string(&v->di_tv, &tofree, numbuf, get_copyID());
7680     list_one_var_a(prefix, v->di_key, v->di_tv.v_type,
7681 					 s == NULL ? (char_u *)"" : s, first);
7682     vim_free(tofree);
7683 }
7684 
7685     static void
7686 list_one_var_a(
7687     char_u	*prefix,
7688     char_u	*name,
7689     int		type,
7690     char_u	*string,
7691     int		*first)  /* when TRUE clear rest of screen and set to FALSE */
7692 {
7693     /* don't use msg() or msg_attr() to avoid overwriting "v:statusmsg" */
7694     msg_start();
7695     msg_puts(prefix);
7696     if (name != NULL)	/* "a:" vars don't have a name stored */
7697 	msg_puts(name);
7698     msg_putchar(' ');
7699     msg_advance(22);
7700     if (type == VAR_NUMBER)
7701 	msg_putchar('#');
7702     else if (type == VAR_FUNC || type == VAR_PARTIAL)
7703 	msg_putchar('*');
7704     else if (type == VAR_LIST)
7705     {
7706 	msg_putchar('[');
7707 	if (*string == '[')
7708 	    ++string;
7709     }
7710     else if (type == VAR_DICT)
7711     {
7712 	msg_putchar('{');
7713 	if (*string == '{')
7714 	    ++string;
7715     }
7716     else
7717 	msg_putchar(' ');
7718 
7719     msg_outtrans(string);
7720 
7721     if (type == VAR_FUNC || type == VAR_PARTIAL)
7722 	msg_puts((char_u *)"()");
7723     if (*first)
7724     {
7725 	msg_clr_eos();
7726 	*first = FALSE;
7727     }
7728 }
7729 
7730 /*
7731  * Set variable "name" to value in "tv".
7732  * If the variable already exists, the value is updated.
7733  * Otherwise the variable is created.
7734  */
7735     void
7736 set_var(
7737     char_u	*name,
7738     typval_T	*tv,
7739     int		copy)	    /* make copy of value in "tv" */
7740 {
7741     dictitem_T	*v;
7742     char_u	*varname;
7743     hashtab_T	*ht;
7744 
7745     ht = find_var_ht(name, &varname);
7746     if (ht == NULL || *varname == NUL)
7747     {
7748 	EMSG2(_(e_illvar), name);
7749 	return;
7750     }
7751     v = find_var_in_ht(ht, 0, varname, TRUE);
7752 
7753     /* Search in parent scope which is possible to reference from lambda */
7754     if (v == NULL)
7755 	v = find_var_in_scoped_ht(name, TRUE);
7756 
7757     if ((tv->v_type == VAR_FUNC || tv->v_type == VAR_PARTIAL)
7758 				      && var_check_func_name(name, v == NULL))
7759 	return;
7760 
7761     if (v != NULL)
7762     {
7763 	/* existing variable, need to clear the value */
7764 	if (var_check_ro(v->di_flags, name, FALSE)
7765 			       || tv_check_lock(v->di_tv.v_lock, name, FALSE))
7766 	    return;
7767 
7768 	/*
7769 	 * Handle setting internal v: variables separately where needed to
7770 	 * prevent changing the type.
7771 	 */
7772 	if (ht == &vimvarht)
7773 	{
7774 	    if (v->di_tv.v_type == VAR_STRING)
7775 	    {
7776 		vim_free(v->di_tv.vval.v_string);
7777 		if (copy || tv->v_type != VAR_STRING)
7778 		    v->di_tv.vval.v_string = vim_strsave(get_tv_string(tv));
7779 		else
7780 		{
7781 		    /* Take over the string to avoid an extra alloc/free. */
7782 		    v->di_tv.vval.v_string = tv->vval.v_string;
7783 		    tv->vval.v_string = NULL;
7784 		}
7785 		return;
7786 	    }
7787 	    else if (v->di_tv.v_type == VAR_NUMBER)
7788 	    {
7789 		v->di_tv.vval.v_number = get_tv_number(tv);
7790 		if (STRCMP(varname, "searchforward") == 0)
7791 		    set_search_direction(v->di_tv.vval.v_number ? '/' : '?');
7792 #ifdef FEAT_SEARCH_EXTRA
7793 		else if (STRCMP(varname, "hlsearch") == 0)
7794 		{
7795 		    no_hlsearch = !v->di_tv.vval.v_number;
7796 		    redraw_all_later(SOME_VALID);
7797 		}
7798 #endif
7799 		return;
7800 	    }
7801 	    else if (v->di_tv.v_type != tv->v_type)
7802 		internal_error("set_var()");
7803 	}
7804 
7805 	clear_tv(&v->di_tv);
7806     }
7807     else		    /* add a new variable */
7808     {
7809 	/* Can't add "v:" variable. */
7810 	if (ht == &vimvarht)
7811 	{
7812 	    EMSG2(_(e_illvar), name);
7813 	    return;
7814 	}
7815 
7816 	/* Make sure the variable name is valid. */
7817 	if (!valid_varname(varname))
7818 	    return;
7819 
7820 	v = (dictitem_T *)alloc((unsigned)(sizeof(dictitem_T)
7821 							  + STRLEN(varname)));
7822 	if (v == NULL)
7823 	    return;
7824 	STRCPY(v->di_key, varname);
7825 	if (hash_add(ht, DI2HIKEY(v)) == FAIL)
7826 	{
7827 	    vim_free(v);
7828 	    return;
7829 	}
7830 	v->di_flags = DI_FLAGS_ALLOC;
7831     }
7832 
7833     if (copy || tv->v_type == VAR_NUMBER || tv->v_type == VAR_FLOAT)
7834 	copy_tv(tv, &v->di_tv);
7835     else
7836     {
7837 	v->di_tv = *tv;
7838 	v->di_tv.v_lock = 0;
7839 	init_tv(tv);
7840     }
7841 }
7842 
7843 /*
7844  * Return TRUE if di_flags "flags" indicates variable "name" is read-only.
7845  * Also give an error message.
7846  */
7847     int
7848 var_check_ro(int flags, char_u *name, int use_gettext)
7849 {
7850     if (flags & DI_FLAGS_RO)
7851     {
7852 	EMSG2(_(e_readonlyvar), use_gettext ? (char_u *)_(name) : name);
7853 	return TRUE;
7854     }
7855     if ((flags & DI_FLAGS_RO_SBX) && sandbox)
7856     {
7857 	EMSG2(_(e_readonlysbx), use_gettext ? (char_u *)_(name) : name);
7858 	return TRUE;
7859     }
7860     return FALSE;
7861 }
7862 
7863 /*
7864  * Return TRUE if di_flags "flags" indicates variable "name" is fixed.
7865  * Also give an error message.
7866  */
7867     int
7868 var_check_fixed(int flags, char_u *name, int use_gettext)
7869 {
7870     if (flags & DI_FLAGS_FIX)
7871     {
7872 	EMSG2(_("E795: Cannot delete variable %s"),
7873 				      use_gettext ? (char_u *)_(name) : name);
7874 	return TRUE;
7875     }
7876     return FALSE;
7877 }
7878 
7879 /*
7880  * Check if a funcref is assigned to a valid variable name.
7881  * Return TRUE and give an error if not.
7882  */
7883     int
7884 var_check_func_name(
7885     char_u *name,    /* points to start of variable name */
7886     int    new_var)  /* TRUE when creating the variable */
7887 {
7888     /* Allow for w: b: s: and t:. */
7889     if (!(vim_strchr((char_u *)"wbst", name[0]) != NULL && name[1] == ':')
7890 	    && !ASCII_ISUPPER((name[0] != NUL && name[1] == ':')
7891 						     ? name[2] : name[0]))
7892     {
7893 	EMSG2(_("E704: Funcref variable name must start with a capital: %s"),
7894 									name);
7895 	return TRUE;
7896     }
7897     /* Don't allow hiding a function.  When "v" is not NULL we might be
7898      * assigning another function to the same var, the type is checked
7899      * below. */
7900     if (new_var && function_exists(name, FALSE))
7901     {
7902 	EMSG2(_("E705: Variable name conflicts with existing function: %s"),
7903 								    name);
7904 	return TRUE;
7905     }
7906     return FALSE;
7907 }
7908 
7909 /*
7910  * Check if a variable name is valid.
7911  * Return FALSE and give an error if not.
7912  */
7913     int
7914 valid_varname(char_u *varname)
7915 {
7916     char_u *p;
7917 
7918     for (p = varname; *p != NUL; ++p)
7919 	if (!eval_isnamec1(*p) && (p == varname || !VIM_ISDIGIT(*p))
7920 						   && *p != AUTOLOAD_CHAR)
7921 	{
7922 	    EMSG2(_(e_illvar), varname);
7923 	    return FALSE;
7924 	}
7925     return TRUE;
7926 }
7927 
7928 /*
7929  * Return TRUE if typeval "tv" is set to be locked (immutable).
7930  * Also give an error message, using "name" or _("name") when use_gettext is
7931  * TRUE.
7932  */
7933     int
7934 tv_check_lock(int lock, char_u *name, int use_gettext)
7935 {
7936     if (lock & VAR_LOCKED)
7937     {
7938 	EMSG2(_("E741: Value is locked: %s"),
7939 				name == NULL ? (char_u *)_("Unknown")
7940 					     : use_gettext ? (char_u *)_(name)
7941 					     : name);
7942 	return TRUE;
7943     }
7944     if (lock & VAR_FIXED)
7945     {
7946 	EMSG2(_("E742: Cannot change value of %s"),
7947 				name == NULL ? (char_u *)_("Unknown")
7948 					     : use_gettext ? (char_u *)_(name)
7949 					     : name);
7950 	return TRUE;
7951     }
7952     return FALSE;
7953 }
7954 
7955 /*
7956  * Copy the values from typval_T "from" to typval_T "to".
7957  * When needed allocates string or increases reference count.
7958  * Does not make a copy of a list or dict but copies the reference!
7959  * It is OK for "from" and "to" to point to the same item.  This is used to
7960  * make a copy later.
7961  */
7962     void
7963 copy_tv(typval_T *from, typval_T *to)
7964 {
7965     to->v_type = from->v_type;
7966     to->v_lock = 0;
7967     switch (from->v_type)
7968     {
7969 	case VAR_NUMBER:
7970 	case VAR_SPECIAL:
7971 	    to->vval.v_number = from->vval.v_number;
7972 	    break;
7973 	case VAR_FLOAT:
7974 #ifdef FEAT_FLOAT
7975 	    to->vval.v_float = from->vval.v_float;
7976 	    break;
7977 #endif
7978 	case VAR_JOB:
7979 #ifdef FEAT_JOB_CHANNEL
7980 	    to->vval.v_job = from->vval.v_job;
7981 	    if (to->vval.v_job != NULL)
7982 		++to->vval.v_job->jv_refcount;
7983 	    break;
7984 #endif
7985 	case VAR_CHANNEL:
7986 #ifdef FEAT_JOB_CHANNEL
7987 	    to->vval.v_channel = from->vval.v_channel;
7988 	    if (to->vval.v_channel != NULL)
7989 		++to->vval.v_channel->ch_refcount;
7990 	    break;
7991 #endif
7992 	case VAR_STRING:
7993 	case VAR_FUNC:
7994 	    if (from->vval.v_string == NULL)
7995 		to->vval.v_string = NULL;
7996 	    else
7997 	    {
7998 		to->vval.v_string = vim_strsave(from->vval.v_string);
7999 		if (from->v_type == VAR_FUNC)
8000 		    func_ref(to->vval.v_string);
8001 	    }
8002 	    break;
8003 	case VAR_PARTIAL:
8004 	    if (from->vval.v_partial == NULL)
8005 		to->vval.v_partial = NULL;
8006 	    else
8007 	    {
8008 		to->vval.v_partial = from->vval.v_partial;
8009 		++to->vval.v_partial->pt_refcount;
8010 	    }
8011 	    break;
8012 	case VAR_LIST:
8013 	    if (from->vval.v_list == NULL)
8014 		to->vval.v_list = NULL;
8015 	    else
8016 	    {
8017 		to->vval.v_list = from->vval.v_list;
8018 		++to->vval.v_list->lv_refcount;
8019 	    }
8020 	    break;
8021 	case VAR_DICT:
8022 	    if (from->vval.v_dict == NULL)
8023 		to->vval.v_dict = NULL;
8024 	    else
8025 	    {
8026 		to->vval.v_dict = from->vval.v_dict;
8027 		++to->vval.v_dict->dv_refcount;
8028 	    }
8029 	    break;
8030 	case VAR_UNKNOWN:
8031 	    internal_error("copy_tv(UNKNOWN)");
8032 	    break;
8033     }
8034 }
8035 
8036 /*
8037  * Make a copy of an item.
8038  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
8039  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
8040  * reference to an already copied list/dict can be used.
8041  * Returns FAIL or OK.
8042  */
8043     int
8044 item_copy(
8045     typval_T	*from,
8046     typval_T	*to,
8047     int		deep,
8048     int		copyID)
8049 {
8050     static int	recurse = 0;
8051     int		ret = OK;
8052 
8053     if (recurse >= DICT_MAXNEST)
8054     {
8055 	EMSG(_("E698: variable nested too deep for making a copy"));
8056 	return FAIL;
8057     }
8058     ++recurse;
8059 
8060     switch (from->v_type)
8061     {
8062 	case VAR_NUMBER:
8063 	case VAR_FLOAT:
8064 	case VAR_STRING:
8065 	case VAR_FUNC:
8066 	case VAR_PARTIAL:
8067 	case VAR_SPECIAL:
8068 	case VAR_JOB:
8069 	case VAR_CHANNEL:
8070 	    copy_tv(from, to);
8071 	    break;
8072 	case VAR_LIST:
8073 	    to->v_type = VAR_LIST;
8074 	    to->v_lock = 0;
8075 	    if (from->vval.v_list == NULL)
8076 		to->vval.v_list = NULL;
8077 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
8078 	    {
8079 		/* use the copy made earlier */
8080 		to->vval.v_list = from->vval.v_list->lv_copylist;
8081 		++to->vval.v_list->lv_refcount;
8082 	    }
8083 	    else
8084 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
8085 	    if (to->vval.v_list == NULL)
8086 		ret = FAIL;
8087 	    break;
8088 	case VAR_DICT:
8089 	    to->v_type = VAR_DICT;
8090 	    to->v_lock = 0;
8091 	    if (from->vval.v_dict == NULL)
8092 		to->vval.v_dict = NULL;
8093 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
8094 	    {
8095 		/* use the copy made earlier */
8096 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
8097 		++to->vval.v_dict->dv_refcount;
8098 	    }
8099 	    else
8100 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
8101 	    if (to->vval.v_dict == NULL)
8102 		ret = FAIL;
8103 	    break;
8104 	case VAR_UNKNOWN:
8105 	    internal_error("item_copy(UNKNOWN)");
8106 	    ret = FAIL;
8107     }
8108     --recurse;
8109     return ret;
8110 }
8111 
8112 /*
8113  * This function is used by f_input() and f_inputdialog() functions. The third
8114  * argument to f_input() specifies the type of completion to use at the
8115  * prompt. The third argument to f_inputdialog() specifies the value to return
8116  * when the user cancels the prompt.
8117  */
8118     void
8119 get_user_input(
8120     typval_T	*argvars,
8121     typval_T	*rettv,
8122     int		inputdialog,
8123     int		secret)
8124 {
8125     char_u	*prompt = get_tv_string_chk(&argvars[0]);
8126     char_u	*p = NULL;
8127     int		c;
8128     char_u	buf[NUMBUFLEN];
8129     int		cmd_silent_save = cmd_silent;
8130     char_u	*defstr = (char_u *)"";
8131     int		xp_type = EXPAND_NOTHING;
8132     char_u	*xp_arg = NULL;
8133 
8134     rettv->v_type = VAR_STRING;
8135     rettv->vval.v_string = NULL;
8136 
8137 #ifdef NO_CONSOLE_INPUT
8138     /* While starting up, there is no place to enter text. When running tests
8139      * with --not-a-term we assume feedkeys() will be used. */
8140     if (no_console_input() && !is_not_a_term())
8141 	return;
8142 #endif
8143 
8144     cmd_silent = FALSE;		/* Want to see the prompt. */
8145     if (prompt != NULL)
8146     {
8147 	/* Only the part of the message after the last NL is considered as
8148 	 * prompt for the command line */
8149 	p = vim_strrchr(prompt, '\n');
8150 	if (p == NULL)
8151 	    p = prompt;
8152 	else
8153 	{
8154 	    ++p;
8155 	    c = *p;
8156 	    *p = NUL;
8157 	    msg_start();
8158 	    msg_clr_eos();
8159 	    msg_puts_attr(prompt, echo_attr);
8160 	    msg_didout = FALSE;
8161 	    msg_starthere();
8162 	    *p = c;
8163 	}
8164 	cmdline_row = msg_row;
8165 
8166 	if (argvars[1].v_type != VAR_UNKNOWN)
8167 	{
8168 	    defstr = get_tv_string_buf_chk(&argvars[1], buf);
8169 	    if (defstr != NULL)
8170 		stuffReadbuffSpec(defstr);
8171 
8172 	    if (!inputdialog && argvars[2].v_type != VAR_UNKNOWN)
8173 	    {
8174 		char_u	*xp_name;
8175 		int	xp_namelen;
8176 		long	argt;
8177 
8178 		/* input() with a third argument: completion */
8179 		rettv->vval.v_string = NULL;
8180 
8181 		xp_name = get_tv_string_buf_chk(&argvars[2], buf);
8182 		if (xp_name == NULL)
8183 		    return;
8184 
8185 		xp_namelen = (int)STRLEN(xp_name);
8186 
8187 		if (parse_compl_arg(xp_name, xp_namelen, &xp_type, &argt,
8188 							     &xp_arg) == FAIL)
8189 		    return;
8190 	    }
8191 	}
8192 
8193 	if (defstr != NULL)
8194 	{
8195 	    int save_ex_normal_busy = ex_normal_busy;
8196 	    ex_normal_busy = 0;
8197 	    rettv->vval.v_string =
8198 		getcmdline_prompt(secret ? NUL : '@', p, echo_attr,
8199 							      xp_type, xp_arg);
8200 	    ex_normal_busy = save_ex_normal_busy;
8201 	}
8202 	if (inputdialog && rettv->vval.v_string == NULL
8203 		&& argvars[1].v_type != VAR_UNKNOWN
8204 		&& argvars[2].v_type != VAR_UNKNOWN)
8205 	    rettv->vval.v_string = vim_strsave(get_tv_string_buf(
8206 							   &argvars[2], buf));
8207 
8208 	vim_free(xp_arg);
8209 
8210 	/* since the user typed this, no need to wait for return */
8211 	need_wait_return = FALSE;
8212 	msg_didout = FALSE;
8213     }
8214     cmd_silent = cmd_silent_save;
8215 }
8216 
8217 /*
8218  * ":echo expr1 ..."	print each argument separated with a space, add a
8219  *			newline at the end.
8220  * ":echon expr1 ..."	print each argument plain.
8221  */
8222     void
8223 ex_echo(exarg_T *eap)
8224 {
8225     char_u	*arg = eap->arg;
8226     typval_T	rettv;
8227     char_u	*tofree;
8228     char_u	*p;
8229     int		needclr = TRUE;
8230     int		atstart = TRUE;
8231     char_u	numbuf[NUMBUFLEN];
8232 
8233     if (eap->skip)
8234 	++emsg_skip;
8235     while (*arg != NUL && *arg != '|' && *arg != '\n' && !got_int)
8236     {
8237 	/* If eval1() causes an error message the text from the command may
8238 	 * still need to be cleared. E.g., "echo 22,44". */
8239 	need_clr_eos = needclr;
8240 
8241 	p = arg;
8242 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8243 	{
8244 	    /*
8245 	     * Report the invalid expression unless the expression evaluation
8246 	     * has been cancelled due to an aborting error, an interrupt, or an
8247 	     * exception.
8248 	     */
8249 	    if (!aborting())
8250 		EMSG2(_(e_invexpr2), p);
8251 	    need_clr_eos = FALSE;
8252 	    break;
8253 	}
8254 	need_clr_eos = FALSE;
8255 
8256 	if (!eap->skip)
8257 	{
8258 	    if (atstart)
8259 	    {
8260 		atstart = FALSE;
8261 		/* Call msg_start() after eval1(), evaluating the expression
8262 		 * may cause a message to appear. */
8263 		if (eap->cmdidx == CMD_echo)
8264 		{
8265 		    /* Mark the saved text as finishing the line, so that what
8266 		     * follows is displayed on a new line when scrolling back
8267 		     * at the more prompt. */
8268 		    msg_sb_eol();
8269 		    msg_start();
8270 		}
8271 	    }
8272 	    else if (eap->cmdidx == CMD_echo)
8273 		msg_puts_attr((char_u *)" ", echo_attr);
8274 	    p = echo_string(&rettv, &tofree, numbuf, get_copyID());
8275 	    if (p != NULL)
8276 		for ( ; *p != NUL && !got_int; ++p)
8277 		{
8278 		    if (*p == '\n' || *p == '\r' || *p == TAB)
8279 		    {
8280 			if (*p != TAB && needclr)
8281 			{
8282 			    /* remove any text still there from the command */
8283 			    msg_clr_eos();
8284 			    needclr = FALSE;
8285 			}
8286 			msg_putchar_attr(*p, echo_attr);
8287 		    }
8288 		    else
8289 		    {
8290 #ifdef FEAT_MBYTE
8291 			if (has_mbyte)
8292 			{
8293 			    int i = (*mb_ptr2len)(p);
8294 
8295 			    (void)msg_outtrans_len_attr(p, i, echo_attr);
8296 			    p += i - 1;
8297 			}
8298 			else
8299 #endif
8300 			    (void)msg_outtrans_len_attr(p, 1, echo_attr);
8301 		    }
8302 		}
8303 	    vim_free(tofree);
8304 	}
8305 	clear_tv(&rettv);
8306 	arg = skipwhite(arg);
8307     }
8308     eap->nextcmd = check_nextcmd(arg);
8309 
8310     if (eap->skip)
8311 	--emsg_skip;
8312     else
8313     {
8314 	/* remove text that may still be there from the command */
8315 	if (needclr)
8316 	    msg_clr_eos();
8317 	if (eap->cmdidx == CMD_echo)
8318 	    msg_end();
8319     }
8320 }
8321 
8322 /*
8323  * ":echohl {name}".
8324  */
8325     void
8326 ex_echohl(exarg_T *eap)
8327 {
8328     echo_attr = syn_name2attr(eap->arg);
8329 }
8330 
8331 /*
8332  * ":execute expr1 ..."	execute the result of an expression.
8333  * ":echomsg expr1 ..."	Print a message
8334  * ":echoerr expr1 ..."	Print an error
8335  * Each gets spaces around each argument and a newline at the end for
8336  * echo commands
8337  */
8338     void
8339 ex_execute(exarg_T *eap)
8340 {
8341     char_u	*arg = eap->arg;
8342     typval_T	rettv;
8343     int		ret = OK;
8344     char_u	*p;
8345     garray_T	ga;
8346     int		len;
8347     int		save_did_emsg;
8348 
8349     ga_init2(&ga, 1, 80);
8350 
8351     if (eap->skip)
8352 	++emsg_skip;
8353     while (*arg != NUL && *arg != '|' && *arg != '\n')
8354     {
8355 	p = arg;
8356 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
8357 	{
8358 	    /*
8359 	     * Report the invalid expression unless the expression evaluation
8360 	     * has been cancelled due to an aborting error, an interrupt, or an
8361 	     * exception.
8362 	     */
8363 	    if (!aborting())
8364 		EMSG2(_(e_invexpr2), p);
8365 	    ret = FAIL;
8366 	    break;
8367 	}
8368 
8369 	if (!eap->skip)
8370 	{
8371 	    p = get_tv_string(&rettv);
8372 	    len = (int)STRLEN(p);
8373 	    if (ga_grow(&ga, len + 2) == FAIL)
8374 	    {
8375 		clear_tv(&rettv);
8376 		ret = FAIL;
8377 		break;
8378 	    }
8379 	    if (ga.ga_len)
8380 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
8381 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
8382 	    ga.ga_len += len;
8383 	}
8384 
8385 	clear_tv(&rettv);
8386 	arg = skipwhite(arg);
8387     }
8388 
8389     if (ret != FAIL && ga.ga_data != NULL)
8390     {
8391 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
8392 	{
8393 	    /* Mark the already saved text as finishing the line, so that what
8394 	     * follows is displayed on a new line when scrolling back at the
8395 	     * more prompt. */
8396 	    msg_sb_eol();
8397 	}
8398 
8399 	if (eap->cmdidx == CMD_echomsg)
8400 	{
8401 	    MSG_ATTR(ga.ga_data, echo_attr);
8402 	    out_flush();
8403 	}
8404 	else if (eap->cmdidx == CMD_echoerr)
8405 	{
8406 	    /* We don't want to abort following commands, restore did_emsg. */
8407 	    save_did_emsg = did_emsg;
8408 	    EMSG((char_u *)ga.ga_data);
8409 	    if (!force_abort)
8410 		did_emsg = save_did_emsg;
8411 	}
8412 	else if (eap->cmdidx == CMD_execute)
8413 	    do_cmdline((char_u *)ga.ga_data,
8414 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
8415     }
8416 
8417     ga_clear(&ga);
8418 
8419     if (eap->skip)
8420 	--emsg_skip;
8421 
8422     eap->nextcmd = check_nextcmd(arg);
8423 }
8424 
8425 /*
8426  * Find window specified by "vp" in tabpage "tp".
8427  */
8428     win_T *
8429 find_win_by_nr(
8430     typval_T	*vp,
8431     tabpage_T	*tp UNUSED)	/* NULL for current tab page */
8432 {
8433     win_T	*wp;
8434     int		nr;
8435 
8436     nr = (int)get_tv_number_chk(vp, NULL);
8437 
8438     if (nr < 0)
8439 	return NULL;
8440     if (nr == 0)
8441 	return curwin;
8442 
8443     FOR_ALL_WINDOWS_IN_TAB(tp, wp)
8444     {
8445 	if (nr >= LOWEST_WIN_ID)
8446 	{
8447 	    if (wp->w_id == nr)
8448 		return wp;
8449 	}
8450 	else if (--nr <= 0)
8451 	    break;
8452     }
8453     if (nr >= LOWEST_WIN_ID)
8454 	return NULL;
8455     return wp;
8456 }
8457 
8458 /*
8459  * Find window specified by "wvp" in tabpage "tvp".
8460  */
8461     win_T *
8462 find_tabwin(
8463     typval_T	*wvp,	/* VAR_UNKNOWN for current window */
8464     typval_T	*tvp)	/* VAR_UNKNOWN for current tab page */
8465 {
8466     win_T	*wp = NULL;
8467     tabpage_T	*tp = NULL;
8468     long	n;
8469 
8470     if (wvp->v_type != VAR_UNKNOWN)
8471     {
8472 	if (tvp->v_type != VAR_UNKNOWN)
8473 	{
8474 	    n = (long)get_tv_number(tvp);
8475 	    if (n >= 0)
8476 		tp = find_tabpage(n);
8477 	}
8478 	else
8479 	    tp = curtab;
8480 
8481 	if (tp != NULL)
8482 	    wp = find_win_by_nr(wvp, tp);
8483     }
8484     else
8485 	wp = curwin;
8486 
8487     return wp;
8488 }
8489 
8490 /*
8491  * getwinvar() and gettabwinvar()
8492  */
8493     void
8494 getwinvar(
8495     typval_T	*argvars,
8496     typval_T	*rettv,
8497     int		off)	    /* 1 for gettabwinvar() */
8498 {
8499     win_T	*win;
8500     char_u	*varname;
8501     dictitem_T	*v;
8502     tabpage_T	*tp = NULL;
8503     int		done = FALSE;
8504     win_T	*oldcurwin;
8505     tabpage_T	*oldtabpage;
8506     int		need_switch_win;
8507 
8508     if (off == 1)
8509 	tp = find_tabpage((int)get_tv_number_chk(&argvars[0], NULL));
8510     else
8511 	tp = curtab;
8512     win = find_win_by_nr(&argvars[off], tp);
8513     varname = get_tv_string_chk(&argvars[off + 1]);
8514     ++emsg_off;
8515 
8516     rettv->v_type = VAR_STRING;
8517     rettv->vval.v_string = NULL;
8518 
8519     if (win != NULL && varname != NULL)
8520     {
8521 	/* Set curwin to be our win, temporarily.  Also set the tabpage,
8522 	 * otherwise the window is not valid. Only do this when needed,
8523 	 * autocommands get blocked. */
8524 	need_switch_win = !(tp == curtab && win == curwin);
8525 	if (!need_switch_win
8526 		  || switch_win(&oldcurwin, &oldtabpage, win, tp, TRUE) == OK)
8527 	{
8528 	    if (*varname == '&')
8529 	    {
8530 		if (varname[1] == NUL)
8531 		{
8532 		    /* get all window-local options in a dict */
8533 		    dict_T	*opts = get_winbuf_options(FALSE);
8534 
8535 		    if (opts != NULL)
8536 		    {
8537 			rettv_dict_set(rettv, opts);
8538 			done = TRUE;
8539 		    }
8540 		}
8541 		else if (get_option_tv(&varname, rettv, 1) == OK)
8542 		    /* window-local-option */
8543 		    done = TRUE;
8544 	    }
8545 	    else
8546 	    {
8547 		/* Look up the variable. */
8548 		/* Let getwinvar({nr}, "") return the "w:" dictionary. */
8549 		v = find_var_in_ht(&win->w_vars->dv_hashtab, 'w',
8550 							      varname, FALSE);
8551 		if (v != NULL)
8552 		{
8553 		    copy_tv(&v->di_tv, rettv);
8554 		    done = TRUE;
8555 		}
8556 	    }
8557 	}
8558 
8559 	if (need_switch_win)
8560 	    /* restore previous notion of curwin */
8561 	    restore_win(oldcurwin, oldtabpage, TRUE);
8562     }
8563 
8564     if (!done && argvars[off + 2].v_type != VAR_UNKNOWN)
8565 	/* use the default return value */
8566 	copy_tv(&argvars[off + 2], rettv);
8567 
8568     --emsg_off;
8569 }
8570 
8571 /*
8572  * "setwinvar()" and "settabwinvar()" functions
8573  */
8574     void
8575 setwinvar(typval_T *argvars, typval_T *rettv UNUSED, int off)
8576 {
8577     win_T	*win;
8578     win_T	*save_curwin;
8579     tabpage_T	*save_curtab;
8580     int		need_switch_win;
8581     char_u	*varname, *winvarname;
8582     typval_T	*varp;
8583     char_u	nbuf[NUMBUFLEN];
8584     tabpage_T	*tp = NULL;
8585 
8586     if (check_restricted() || check_secure())
8587 	return;
8588 
8589     if (off == 1)
8590 	tp = find_tabpage((int)get_tv_number_chk(&argvars[0], NULL));
8591     else
8592 	tp = curtab;
8593     win = find_win_by_nr(&argvars[off], tp);
8594     varname = get_tv_string_chk(&argvars[off + 1]);
8595     varp = &argvars[off + 2];
8596 
8597     if (win != NULL && varname != NULL && varp != NULL)
8598     {
8599 	need_switch_win = !(tp == curtab && win == curwin);
8600 	if (!need_switch_win
8601 	       || switch_win(&save_curwin, &save_curtab, win, tp, TRUE) == OK)
8602 	{
8603 	    if (*varname == '&')
8604 	    {
8605 		long	numval;
8606 		char_u	*strval;
8607 		int		error = FALSE;
8608 
8609 		++varname;
8610 		numval = (long)get_tv_number_chk(varp, &error);
8611 		strval = get_tv_string_buf_chk(varp, nbuf);
8612 		if (!error && strval != NULL)
8613 		    set_option_value(varname, numval, strval, OPT_LOCAL);
8614 	    }
8615 	    else
8616 	    {
8617 		winvarname = alloc((unsigned)STRLEN(varname) + 3);
8618 		if (winvarname != NULL)
8619 		{
8620 		    STRCPY(winvarname, "w:");
8621 		    STRCPY(winvarname + 2, varname);
8622 		    set_var(winvarname, varp, TRUE);
8623 		    vim_free(winvarname);
8624 		}
8625 	    }
8626 	}
8627 	if (need_switch_win)
8628 	    restore_win(save_curwin, save_curtab, TRUE);
8629     }
8630 }
8631 
8632 /*
8633  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
8634  * "arg" points to the "&" or '+' when called, to "option" when returning.
8635  * Returns NULL when no option name found.  Otherwise pointer to the char
8636  * after the option name.
8637  */
8638     static char_u *
8639 find_option_end(char_u **arg, int *opt_flags)
8640 {
8641     char_u	*p = *arg;
8642 
8643     ++p;
8644     if (*p == 'g' && p[1] == ':')
8645     {
8646 	*opt_flags = OPT_GLOBAL;
8647 	p += 2;
8648     }
8649     else if (*p == 'l' && p[1] == ':')
8650     {
8651 	*opt_flags = OPT_LOCAL;
8652 	p += 2;
8653     }
8654     else
8655 	*opt_flags = 0;
8656 
8657     if (!ASCII_ISALPHA(*p))
8658 	return NULL;
8659     *arg = p;
8660 
8661     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
8662 	p += 4;	    /* termcap option */
8663     else
8664 	while (ASCII_ISALPHA(*p))
8665 	    ++p;
8666     return p;
8667 }
8668 
8669 /*
8670  * Return the autoload script name for a function or variable name.
8671  * Returns NULL when out of memory.
8672  */
8673     char_u *
8674 autoload_name(char_u *name)
8675 {
8676     char_u	*p;
8677     char_u	*scriptname;
8678 
8679     /* Get the script file name: replace '#' with '/', append ".vim". */
8680     scriptname = alloc((unsigned)(STRLEN(name) + 14));
8681     if (scriptname == NULL)
8682 	return FALSE;
8683     STRCPY(scriptname, "autoload/");
8684     STRCAT(scriptname, name);
8685     *vim_strrchr(scriptname, AUTOLOAD_CHAR) = NUL;
8686     STRCAT(scriptname, ".vim");
8687     while ((p = vim_strchr(scriptname, AUTOLOAD_CHAR)) != NULL)
8688 	*p = '/';
8689     return scriptname;
8690 }
8691 
8692 /*
8693  * If "name" has a package name try autoloading the script for it.
8694  * Return TRUE if a package was loaded.
8695  */
8696     int
8697 script_autoload(
8698     char_u	*name,
8699     int		reload)	    /* load script again when already loaded */
8700 {
8701     char_u	*p;
8702     char_u	*scriptname, *tofree;
8703     int		ret = FALSE;
8704     int		i;
8705 
8706     /* If there is no '#' after name[0] there is no package name. */
8707     p = vim_strchr(name, AUTOLOAD_CHAR);
8708     if (p == NULL || p == name)
8709 	return FALSE;
8710 
8711     tofree = scriptname = autoload_name(name);
8712 
8713     /* Find the name in the list of previously loaded package names.  Skip
8714      * "autoload/", it's always the same. */
8715     for (i = 0; i < ga_loaded.ga_len; ++i)
8716 	if (STRCMP(((char_u **)ga_loaded.ga_data)[i] + 9, scriptname + 9) == 0)
8717 	    break;
8718     if (!reload && i < ga_loaded.ga_len)
8719 	ret = FALSE;	    /* was loaded already */
8720     else
8721     {
8722 	/* Remember the name if it wasn't loaded already. */
8723 	if (i == ga_loaded.ga_len && ga_grow(&ga_loaded, 1) == OK)
8724 	{
8725 	    ((char_u **)ga_loaded.ga_data)[ga_loaded.ga_len++] = scriptname;
8726 	    tofree = NULL;
8727 	}
8728 
8729 	/* Try loading the package from $VIMRUNTIME/autoload/<name>.vim */
8730 	if (source_runtime(scriptname, 0) == OK)
8731 	    ret = TRUE;
8732     }
8733 
8734     vim_free(tofree);
8735     return ret;
8736 }
8737 
8738 #if defined(FEAT_VIMINFO) || defined(FEAT_SESSION)
8739 typedef enum
8740 {
8741     VAR_FLAVOUR_DEFAULT,	/* doesn't start with uppercase */
8742     VAR_FLAVOUR_SESSION,	/* starts with uppercase, some lower */
8743     VAR_FLAVOUR_VIMINFO		/* all uppercase */
8744 } var_flavour_T;
8745 
8746 static var_flavour_T var_flavour(char_u *varname);
8747 
8748     static var_flavour_T
8749 var_flavour(char_u *varname)
8750 {
8751     char_u *p = varname;
8752 
8753     if (ASCII_ISUPPER(*p))
8754     {
8755 	while (*(++p))
8756 	    if (ASCII_ISLOWER(*p))
8757 		return VAR_FLAVOUR_SESSION;
8758 	return VAR_FLAVOUR_VIMINFO;
8759     }
8760     else
8761 	return VAR_FLAVOUR_DEFAULT;
8762 }
8763 #endif
8764 
8765 #if defined(FEAT_VIMINFO) || defined(PROTO)
8766 /*
8767  * Restore global vars that start with a capital from the viminfo file
8768  */
8769     int
8770 read_viminfo_varlist(vir_T *virp, int writing)
8771 {
8772     char_u	*tab;
8773     int		type = VAR_NUMBER;
8774     typval_T	tv;
8775     void	*save_funccal;
8776 
8777     if (!writing && (find_viminfo_parameter('!') != NULL))
8778     {
8779 	tab = vim_strchr(virp->vir_line + 1, '\t');
8780 	if (tab != NULL)
8781 	{
8782 	    *tab++ = '\0';	/* isolate the variable name */
8783 	    switch (*tab)
8784 	    {
8785 		case 'S': type = VAR_STRING; break;
8786 #ifdef FEAT_FLOAT
8787 		case 'F': type = VAR_FLOAT; break;
8788 #endif
8789 		case 'D': type = VAR_DICT; break;
8790 		case 'L': type = VAR_LIST; break;
8791 		case 'X': type = VAR_SPECIAL; break;
8792 	    }
8793 
8794 	    tab = vim_strchr(tab, '\t');
8795 	    if (tab != NULL)
8796 	    {
8797 		tv.v_type = type;
8798 		if (type == VAR_STRING || type == VAR_DICT || type == VAR_LIST)
8799 		    tv.vval.v_string = viminfo_readstring(virp,
8800 				       (int)(tab - virp->vir_line + 1), TRUE);
8801 #ifdef FEAT_FLOAT
8802 		else if (type == VAR_FLOAT)
8803 		    (void)string2float(tab + 1, &tv.vval.v_float);
8804 #endif
8805 		else
8806 		    tv.vval.v_number = atol((char *)tab + 1);
8807 		if (type == VAR_DICT || type == VAR_LIST)
8808 		{
8809 		    typval_T *etv = eval_expr(tv.vval.v_string, NULL);
8810 
8811 		    if (etv == NULL)
8812 			/* Failed to parse back the dict or list, use it as a
8813 			 * string. */
8814 			tv.v_type = VAR_STRING;
8815 		    else
8816 		    {
8817 			vim_free(tv.vval.v_string);
8818 			tv = *etv;
8819 			vim_free(etv);
8820 		    }
8821 		}
8822 
8823 		/* when in a function use global variables */
8824 		save_funccal = clear_current_funccal();
8825 		set_var(virp->vir_line + 1, &tv, FALSE);
8826 		restore_current_funccal(save_funccal);
8827 
8828 		if (tv.v_type == VAR_STRING)
8829 		    vim_free(tv.vval.v_string);
8830 		else if (tv.v_type == VAR_DICT || tv.v_type == VAR_LIST)
8831 		    clear_tv(&tv);
8832 	    }
8833 	}
8834     }
8835 
8836     return viminfo_readline(virp);
8837 }
8838 
8839 /*
8840  * Write global vars that start with a capital to the viminfo file
8841  */
8842     void
8843 write_viminfo_varlist(FILE *fp)
8844 {
8845     hashitem_T	*hi;
8846     dictitem_T	*this_var;
8847     int		todo;
8848     char	*s = "";
8849     char_u	*p;
8850     char_u	*tofree;
8851     char_u	numbuf[NUMBUFLEN];
8852 
8853     if (find_viminfo_parameter('!') == NULL)
8854 	return;
8855 
8856     fputs(_("\n# global variables:\n"), fp);
8857 
8858     todo = (int)globvarht.ht_used;
8859     for (hi = globvarht.ht_array; todo > 0; ++hi)
8860     {
8861 	if (!HASHITEM_EMPTY(hi))
8862 	{
8863 	    --todo;
8864 	    this_var = HI2DI(hi);
8865 	    if (var_flavour(this_var->di_key) == VAR_FLAVOUR_VIMINFO)
8866 	    {
8867 		switch (this_var->di_tv.v_type)
8868 		{
8869 		    case VAR_STRING: s = "STR"; break;
8870 		    case VAR_NUMBER: s = "NUM"; break;
8871 		    case VAR_FLOAT:  s = "FLO"; break;
8872 		    case VAR_DICT:   s = "DIC"; break;
8873 		    case VAR_LIST:   s = "LIS"; break;
8874 		    case VAR_SPECIAL: s = "XPL"; break;
8875 
8876 		    case VAR_UNKNOWN:
8877 		    case VAR_FUNC:
8878 		    case VAR_PARTIAL:
8879 		    case VAR_JOB:
8880 		    case VAR_CHANNEL:
8881 				     continue;
8882 		}
8883 		fprintf(fp, "!%s\t%s\t", this_var->di_key, s);
8884 		p = echo_string(&this_var->di_tv, &tofree, numbuf, 0);
8885 		if (p != NULL)
8886 		    viminfo_writestring(fp, p);
8887 		vim_free(tofree);
8888 	    }
8889 	}
8890     }
8891 }
8892 #endif
8893 
8894 #if defined(FEAT_SESSION) || defined(PROTO)
8895     int
8896 store_session_globals(FILE *fd)
8897 {
8898     hashitem_T	*hi;
8899     dictitem_T	*this_var;
8900     int		todo;
8901     char_u	*p, *t;
8902 
8903     todo = (int)globvarht.ht_used;
8904     for (hi = globvarht.ht_array; todo > 0; ++hi)
8905     {
8906 	if (!HASHITEM_EMPTY(hi))
8907 	{
8908 	    --todo;
8909 	    this_var = HI2DI(hi);
8910 	    if ((this_var->di_tv.v_type == VAR_NUMBER
8911 			|| this_var->di_tv.v_type == VAR_STRING)
8912 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
8913 	    {
8914 		/* Escape special characters with a backslash.  Turn a LF and
8915 		 * CR into \n and \r. */
8916 		p = vim_strsave_escaped(get_tv_string(&this_var->di_tv),
8917 							(char_u *)"\\\"\n\r");
8918 		if (p == NULL)	    /* out of memory */
8919 		    break;
8920 		for (t = p; *t != NUL; ++t)
8921 		    if (*t == '\n')
8922 			*t = 'n';
8923 		    else if (*t == '\r')
8924 			*t = 'r';
8925 		if ((fprintf(fd, "let %s = %c%s%c",
8926 				this_var->di_key,
8927 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
8928 									: ' ',
8929 				p,
8930 				(this_var->di_tv.v_type == VAR_STRING) ? '"'
8931 								   : ' ') < 0)
8932 			|| put_eol(fd) == FAIL)
8933 		{
8934 		    vim_free(p);
8935 		    return FAIL;
8936 		}
8937 		vim_free(p);
8938 	    }
8939 #ifdef FEAT_FLOAT
8940 	    else if (this_var->di_tv.v_type == VAR_FLOAT
8941 		    && var_flavour(this_var->di_key) == VAR_FLAVOUR_SESSION)
8942 	    {
8943 		float_T f = this_var->di_tv.vval.v_float;
8944 		int sign = ' ';
8945 
8946 		if (f < 0)
8947 		{
8948 		    f = -f;
8949 		    sign = '-';
8950 		}
8951 		if ((fprintf(fd, "let %s = %c%f",
8952 					       this_var->di_key, sign, f) < 0)
8953 			|| put_eol(fd) == FAIL)
8954 		    return FAIL;
8955 	    }
8956 #endif
8957 	}
8958     }
8959     return OK;
8960 }
8961 #endif
8962 
8963 /*
8964  * Display script name where an item was last set.
8965  * Should only be invoked when 'verbose' is non-zero.
8966  */
8967     void
8968 last_set_msg(scid_T scriptID)
8969 {
8970     char_u *p;
8971 
8972     if (scriptID != 0)
8973     {
8974 	p = home_replace_save(NULL, get_scriptname(scriptID));
8975 	if (p != NULL)
8976 	{
8977 	    verbose_enter();
8978 	    MSG_PUTS(_("\n\tLast set from "));
8979 	    MSG_PUTS(p);
8980 	    vim_free(p);
8981 	    verbose_leave();
8982 	}
8983     }
8984 }
8985 
8986 /* reset v:option_new, v:option_old and v:option_type */
8987     void
8988 reset_v_option_vars(void)
8989 {
8990     set_vim_var_string(VV_OPTION_NEW,  NULL, -1);
8991     set_vim_var_string(VV_OPTION_OLD,  NULL, -1);
8992     set_vim_var_string(VV_OPTION_TYPE, NULL, -1);
8993 }
8994 
8995 /*
8996  * Prepare "gap" for an assert error and add the sourcing position.
8997  */
8998     void
8999 prepare_assert_error(garray_T *gap)
9000 {
9001     char buf[NUMBUFLEN];
9002 
9003     ga_init2(gap, 1, 100);
9004     if (sourcing_name != NULL)
9005     {
9006 	ga_concat(gap, sourcing_name);
9007 	if (sourcing_lnum > 0)
9008 	    ga_concat(gap, (char_u *)" ");
9009     }
9010     if (sourcing_lnum > 0)
9011     {
9012 	sprintf(buf, "line %ld", (long)sourcing_lnum);
9013 	ga_concat(gap, (char_u *)buf);
9014     }
9015     if (sourcing_name != NULL || sourcing_lnum > 0)
9016 	ga_concat(gap, (char_u *)": ");
9017 }
9018 
9019 /*
9020  * Add an assert error to v:errors.
9021  */
9022     void
9023 assert_error(garray_T *gap)
9024 {
9025     struct vimvar   *vp = &vimvars[VV_ERRORS];
9026 
9027     if (vp->vv_type != VAR_LIST || vimvars[VV_ERRORS].vv_list == NULL)
9028 	/* Make sure v:errors is a list. */
9029 	set_vim_var_list(VV_ERRORS, list_alloc());
9030     list_append_string(vimvars[VV_ERRORS].vv_list, gap->ga_data, gap->ga_len);
9031 }
9032 
9033     void
9034 assert_equal_common(typval_T *argvars, assert_type_T atype)
9035 {
9036     garray_T	ga;
9037 
9038     if (tv_equal(&argvars[0], &argvars[1], FALSE, FALSE)
9039 						   != (atype == ASSERT_EQUAL))
9040     {
9041 	prepare_assert_error(&ga);
9042 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
9043 								       atype);
9044 	assert_error(&ga);
9045 	ga_clear(&ga);
9046     }
9047 }
9048 
9049     void
9050 assert_match_common(typval_T *argvars, assert_type_T atype)
9051 {
9052     garray_T	ga;
9053     char_u	buf1[NUMBUFLEN];
9054     char_u	buf2[NUMBUFLEN];
9055     char_u	*pat = get_tv_string_buf_chk(&argvars[0], buf1);
9056     char_u	*text = get_tv_string_buf_chk(&argvars[1], buf2);
9057 
9058     if (pat == NULL || text == NULL)
9059 	EMSG(_(e_invarg));
9060     else if (pattern_match(pat, text, FALSE) != (atype == ASSERT_MATCH))
9061     {
9062 	prepare_assert_error(&ga);
9063 	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
9064 									atype);
9065 	assert_error(&ga);
9066 	ga_clear(&ga);
9067     }
9068 }
9069 
9070     void
9071 assert_inrange(typval_T *argvars)
9072 {
9073     garray_T	ga;
9074     int		error = FALSE;
9075     varnumber_T	lower = get_tv_number_chk(&argvars[0], &error);
9076     varnumber_T	upper = get_tv_number_chk(&argvars[1], &error);
9077     varnumber_T	actual = get_tv_number_chk(&argvars[2], &error);
9078     char_u	*tofree;
9079     char	msg[200];
9080     char_u	numbuf[NUMBUFLEN];
9081 
9082     if (error)
9083 	return;
9084     if (actual < lower || actual > upper)
9085     {
9086 	prepare_assert_error(&ga);
9087 	if (argvars[3].v_type != VAR_UNKNOWN)
9088 	{
9089 	    ga_concat(&ga, tv2string(&argvars[3], &tofree, numbuf, 0));
9090 	    vim_free(tofree);
9091 	}
9092 	else
9093 	{
9094 	    vim_snprintf(msg, 200, "Expected range %ld - %ld, but got %ld",
9095 				       (long)lower, (long)upper, (long)actual);
9096 	    ga_concat(&ga, (char_u *)msg);
9097 	}
9098 	assert_error(&ga);
9099 	ga_clear(&ga);
9100     }
9101 }
9102 
9103 /*
9104  * Common for assert_true() and assert_false().
9105  */
9106     void
9107 assert_bool(typval_T *argvars, int isTrue)
9108 {
9109     int		error = FALSE;
9110     garray_T	ga;
9111 
9112     if (argvars[0].v_type == VAR_SPECIAL
9113 	    && argvars[0].vval.v_number == (isTrue ? VVAL_TRUE : VVAL_FALSE))
9114 	return;
9115     if (argvars[0].v_type != VAR_NUMBER
9116 	    || (get_tv_number_chk(&argvars[0], &error) == 0) == isTrue
9117 	    || error)
9118     {
9119 	prepare_assert_error(&ga);
9120 	fill_assert_error(&ga, &argvars[1],
9121 		(char_u *)(isTrue ? "True" : "False"),
9122 		NULL, &argvars[0], ASSERT_OTHER);
9123 	assert_error(&ga);
9124 	ga_clear(&ga);
9125     }
9126 }
9127 
9128     void
9129 assert_report(typval_T *argvars)
9130 {
9131     garray_T	ga;
9132 
9133     prepare_assert_error(&ga);
9134     ga_concat(&ga, get_tv_string(&argvars[0]));
9135     assert_error(&ga);
9136     ga_clear(&ga);
9137 }
9138 
9139     void
9140 assert_exception(typval_T *argvars)
9141 {
9142     garray_T	ga;
9143     char_u	*error = get_tv_string_chk(&argvars[0]);
9144 
9145     if (vimvars[VV_EXCEPTION].vv_str == NULL)
9146     {
9147 	prepare_assert_error(&ga);
9148 	ga_concat(&ga, (char_u *)"v:exception is not set");
9149 	assert_error(&ga);
9150 	ga_clear(&ga);
9151     }
9152     else if (error != NULL
9153 	&& strstr((char *)vimvars[VV_EXCEPTION].vv_str, (char *)error) == NULL)
9154     {
9155 	prepare_assert_error(&ga);
9156 	fill_assert_error(&ga, &argvars[1], NULL, &argvars[0],
9157 				  &vimvars[VV_EXCEPTION].vv_tv, ASSERT_OTHER);
9158 	assert_error(&ga);
9159 	ga_clear(&ga);
9160     }
9161 }
9162 
9163     void
9164 assert_fails(typval_T *argvars)
9165 {
9166     char_u	*cmd = get_tv_string_chk(&argvars[0]);
9167     garray_T	ga;
9168 
9169     called_emsg = FALSE;
9170     suppress_errthrow = TRUE;
9171     emsg_silent = TRUE;
9172     do_cmdline_cmd(cmd);
9173     if (!called_emsg)
9174     {
9175 	prepare_assert_error(&ga);
9176 	ga_concat(&ga, (char_u *)"command did not fail: ");
9177 	ga_concat(&ga, cmd);
9178 	assert_error(&ga);
9179 	ga_clear(&ga);
9180     }
9181     else if (argvars[1].v_type != VAR_UNKNOWN)
9182     {
9183 	char_u	buf[NUMBUFLEN];
9184 	char	*error = (char *)get_tv_string_buf_chk(&argvars[1], buf);
9185 
9186 	if (error == NULL
9187 		  || strstr((char *)vimvars[VV_ERRMSG].vv_str, error) == NULL)
9188 	{
9189 	    prepare_assert_error(&ga);
9190 	    fill_assert_error(&ga, &argvars[2], NULL, &argvars[1],
9191 				     &vimvars[VV_ERRMSG].vv_tv, ASSERT_OTHER);
9192 	    assert_error(&ga);
9193 	    ga_clear(&ga);
9194 	}
9195     }
9196 
9197     called_emsg = FALSE;
9198     suppress_errthrow = FALSE;
9199     emsg_silent = FALSE;
9200     emsg_on_display = FALSE;
9201     set_vim_var_string(VV_ERRMSG, NULL, 0);
9202 }
9203 
9204 /*
9205  * Append "str" to "gap", escaping unprintable characters.
9206  * Changes NL to \n, CR to \r, etc.
9207  */
9208     static void
9209 ga_concat_esc(garray_T *gap, char_u *str)
9210 {
9211     char_u  *p;
9212     char_u  buf[NUMBUFLEN];
9213 
9214     if (str == NULL)
9215     {
9216 	ga_concat(gap, (char_u *)"NULL");
9217 	return;
9218     }
9219 
9220     for (p = str; *p != NUL; ++p)
9221 	switch (*p)
9222 	{
9223 	    case BS: ga_concat(gap, (char_u *)"\\b"); break;
9224 	    case ESC: ga_concat(gap, (char_u *)"\\e"); break;
9225 	    case FF: ga_concat(gap, (char_u *)"\\f"); break;
9226 	    case NL: ga_concat(gap, (char_u *)"\\n"); break;
9227 	    case TAB: ga_concat(gap, (char_u *)"\\t"); break;
9228 	    case CAR: ga_concat(gap, (char_u *)"\\r"); break;
9229 	    case '\\': ga_concat(gap, (char_u *)"\\\\"); break;
9230 	    default:
9231 		if (*p < ' ')
9232 		{
9233 		    vim_snprintf((char *)buf, NUMBUFLEN, "\\x%02x", *p);
9234 		    ga_concat(gap, buf);
9235 		}
9236 		else
9237 		    ga_append(gap, *p);
9238 		break;
9239 	}
9240 }
9241 
9242 /*
9243  * Fill "gap" with information about an assert error.
9244  */
9245     void
9246 fill_assert_error(
9247     garray_T	*gap,
9248     typval_T	*opt_msg_tv,
9249     char_u      *exp_str,
9250     typval_T	*exp_tv,
9251     typval_T	*got_tv,
9252     assert_type_T atype)
9253 {
9254     char_u	numbuf[NUMBUFLEN];
9255     char_u	*tofree;
9256 
9257     if (opt_msg_tv->v_type != VAR_UNKNOWN)
9258     {
9259 	ga_concat(gap, echo_string(opt_msg_tv, &tofree, numbuf, 0));
9260 	vim_free(tofree);
9261 	ga_concat(gap, (char_u *)": ");
9262     }
9263 
9264     if (atype == ASSERT_MATCH || atype == ASSERT_NOTMATCH)
9265 	ga_concat(gap, (char_u *)"Pattern ");
9266     else if (atype == ASSERT_NOTEQUAL)
9267 	ga_concat(gap, (char_u *)"Expected not equal to ");
9268     else
9269 	ga_concat(gap, (char_u *)"Expected ");
9270     if (exp_str == NULL)
9271     {
9272 	ga_concat_esc(gap, tv2string(exp_tv, &tofree, numbuf, 0));
9273 	vim_free(tofree);
9274     }
9275     else
9276 	ga_concat_esc(gap, exp_str);
9277     if (atype != ASSERT_NOTEQUAL)
9278     {
9279 	if (atype == ASSERT_MATCH)
9280 	    ga_concat(gap, (char_u *)" does not match ");
9281 	else if (atype == ASSERT_NOTMATCH)
9282 	    ga_concat(gap, (char_u *)" does match ");
9283 	else
9284 	    ga_concat(gap, (char_u *)" but got ");
9285 	ga_concat_esc(gap, tv2string(got_tv, &tofree, numbuf, 0));
9286 	vim_free(tofree);
9287     }
9288 }
9289 
9290 
9291 #endif /* FEAT_EVAL */
9292 
9293 
9294 #if defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) || defined(PROTO)
9295 
9296 #ifdef WIN3264
9297 /*
9298  * Functions for ":8" filename modifier: get 8.3 version of a filename.
9299  */
9300 static int get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen);
9301 static int shortpath_for_invalid_fname(char_u **fname, char_u **bufp, int *fnamelen);
9302 static int shortpath_for_partial(char_u **fnamep, char_u **bufp, int *fnamelen);
9303 
9304 /*
9305  * Get the short path (8.3) for the filename in "fnamep".
9306  * Only works for a valid file name.
9307  * When the path gets longer "fnamep" is changed and the allocated buffer
9308  * is put in "bufp".
9309  * *fnamelen is the length of "fnamep" and set to 0 for a nonexistent path.
9310  * Returns OK on success, FAIL on failure.
9311  */
9312     static int
9313 get_short_pathname(char_u **fnamep, char_u **bufp, int *fnamelen)
9314 {
9315     int		l, len;
9316     char_u	*newbuf;
9317 
9318     len = *fnamelen;
9319     l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, len);
9320     if (l > len - 1)
9321     {
9322 	/* If that doesn't work (not enough space), then save the string
9323 	 * and try again with a new buffer big enough. */
9324 	newbuf = vim_strnsave(*fnamep, l);
9325 	if (newbuf == NULL)
9326 	    return FAIL;
9327 
9328 	vim_free(*bufp);
9329 	*fnamep = *bufp = newbuf;
9330 
9331 	/* Really should always succeed, as the buffer is big enough. */
9332 	l = GetShortPathName((LPSTR)*fnamep, (LPSTR)*fnamep, l+1);
9333     }
9334 
9335     *fnamelen = l;
9336     return OK;
9337 }
9338 
9339 /*
9340  * Get the short path (8.3) for the filename in "fname". The converted
9341  * path is returned in "bufp".
9342  *
9343  * Some of the directories specified in "fname" may not exist. This function
9344  * will shorten the existing directories at the beginning of the path and then
9345  * append the remaining non-existing path.
9346  *
9347  * fname - Pointer to the filename to shorten.  On return, contains the
9348  *	   pointer to the shortened pathname
9349  * bufp -  Pointer to an allocated buffer for the filename.
9350  * fnamelen - Length of the filename pointed to by fname
9351  *
9352  * Returns OK on success (or nothing done) and FAIL on failure (out of memory).
9353  */
9354     static int
9355 shortpath_for_invalid_fname(
9356     char_u	**fname,
9357     char_u	**bufp,
9358     int		*fnamelen)
9359 {
9360     char_u	*short_fname, *save_fname, *pbuf_unused;
9361     char_u	*endp, *save_endp;
9362     char_u	ch;
9363     int		old_len, len;
9364     int		new_len, sfx_len;
9365     int		retval = OK;
9366 
9367     /* Make a copy */
9368     old_len = *fnamelen;
9369     save_fname = vim_strnsave(*fname, old_len);
9370     pbuf_unused = NULL;
9371     short_fname = NULL;
9372 
9373     endp = save_fname + old_len - 1; /* Find the end of the copy */
9374     save_endp = endp;
9375 
9376     /*
9377      * Try shortening the supplied path till it succeeds by removing one
9378      * directory at a time from the tail of the path.
9379      */
9380     len = 0;
9381     for (;;)
9382     {
9383 	/* go back one path-separator */
9384 	while (endp > save_fname && !after_pathsep(save_fname, endp + 1))
9385 	    --endp;
9386 	if (endp <= save_fname)
9387 	    break;		/* processed the complete path */
9388 
9389 	/*
9390 	 * Replace the path separator with a NUL and try to shorten the
9391 	 * resulting path.
9392 	 */
9393 	ch = *endp;
9394 	*endp = 0;
9395 	short_fname = save_fname;
9396 	len = (int)STRLEN(short_fname) + 1;
9397 	if (get_short_pathname(&short_fname, &pbuf_unused, &len) == FAIL)
9398 	{
9399 	    retval = FAIL;
9400 	    goto theend;
9401 	}
9402 	*endp = ch;	/* preserve the string */
9403 
9404 	if (len > 0)
9405 	    break;	/* successfully shortened the path */
9406 
9407 	/* failed to shorten the path. Skip the path separator */
9408 	--endp;
9409     }
9410 
9411     if (len > 0)
9412     {
9413 	/*
9414 	 * Succeeded in shortening the path. Now concatenate the shortened
9415 	 * path with the remaining path at the tail.
9416 	 */
9417 
9418 	/* Compute the length of the new path. */
9419 	sfx_len = (int)(save_endp - endp) + 1;
9420 	new_len = len + sfx_len;
9421 
9422 	*fnamelen = new_len;
9423 	vim_free(*bufp);
9424 	if (new_len > old_len)
9425 	{
9426 	    /* There is not enough space in the currently allocated string,
9427 	     * copy it to a buffer big enough. */
9428 	    *fname = *bufp = vim_strnsave(short_fname, new_len);
9429 	    if (*fname == NULL)
9430 	    {
9431 		retval = FAIL;
9432 		goto theend;
9433 	    }
9434 	}
9435 	else
9436 	{
9437 	    /* Transfer short_fname to the main buffer (it's big enough),
9438 	     * unless get_short_pathname() did its work in-place. */
9439 	    *fname = *bufp = save_fname;
9440 	    if (short_fname != save_fname)
9441 		vim_strncpy(save_fname, short_fname, len);
9442 	    save_fname = NULL;
9443 	}
9444 
9445 	/* concat the not-shortened part of the path */
9446 	vim_strncpy(*fname + len, endp, sfx_len);
9447 	(*fname)[new_len] = NUL;
9448     }
9449 
9450 theend:
9451     vim_free(pbuf_unused);
9452     vim_free(save_fname);
9453 
9454     return retval;
9455 }
9456 
9457 /*
9458  * Get a pathname for a partial path.
9459  * Returns OK for success, FAIL for failure.
9460  */
9461     static int
9462 shortpath_for_partial(
9463     char_u	**fnamep,
9464     char_u	**bufp,
9465     int		*fnamelen)
9466 {
9467     int		sepcount, len, tflen;
9468     char_u	*p;
9469     char_u	*pbuf, *tfname;
9470     int		hasTilde;
9471 
9472     /* Count up the path separators from the RHS.. so we know which part
9473      * of the path to return. */
9474     sepcount = 0;
9475     for (p = *fnamep; p < *fnamep + *fnamelen; MB_PTR_ADV(p))
9476 	if (vim_ispathsep(*p))
9477 	    ++sepcount;
9478 
9479     /* Need full path first (use expand_env() to remove a "~/") */
9480     hasTilde = (**fnamep == '~');
9481     if (hasTilde)
9482 	pbuf = tfname = expand_env_save(*fnamep);
9483     else
9484 	pbuf = tfname = FullName_save(*fnamep, FALSE);
9485 
9486     len = tflen = (int)STRLEN(tfname);
9487 
9488     if (get_short_pathname(&tfname, &pbuf, &len) == FAIL)
9489 	return FAIL;
9490 
9491     if (len == 0)
9492     {
9493 	/* Don't have a valid filename, so shorten the rest of the
9494 	 * path if we can. This CAN give us invalid 8.3 filenames, but
9495 	 * there's not a lot of point in guessing what it might be.
9496 	 */
9497 	len = tflen;
9498 	if (shortpath_for_invalid_fname(&tfname, &pbuf, &len) == FAIL)
9499 	    return FAIL;
9500     }
9501 
9502     /* Count the paths backward to find the beginning of the desired string. */
9503     for (p = tfname + len - 1; p >= tfname; --p)
9504     {
9505 #ifdef FEAT_MBYTE
9506 	if (has_mbyte)
9507 	    p -= mb_head_off(tfname, p);
9508 #endif
9509 	if (vim_ispathsep(*p))
9510 	{
9511 	    if (sepcount == 0 || (hasTilde && sepcount == 1))
9512 		break;
9513 	    else
9514 		sepcount --;
9515 	}
9516     }
9517     if (hasTilde)
9518     {
9519 	--p;
9520 	if (p >= tfname)
9521 	    *p = '~';
9522 	else
9523 	    return FAIL;
9524     }
9525     else
9526 	++p;
9527 
9528     /* Copy in the string - p indexes into tfname - allocated at pbuf */
9529     vim_free(*bufp);
9530     *fnamelen = (int)STRLEN(p);
9531     *bufp = pbuf;
9532     *fnamep = p;
9533 
9534     return OK;
9535 }
9536 #endif /* WIN3264 */
9537 
9538 /*
9539  * Adjust a filename, according to a string of modifiers.
9540  * *fnamep must be NUL terminated when called.  When returning, the length is
9541  * determined by *fnamelen.
9542  * Returns VALID_ flags or -1 for failure.
9543  * When there is an error, *fnamep is set to NULL.
9544  */
9545     int
9546 modify_fname(
9547     char_u	*src,		/* string with modifiers */
9548     int		*usedlen,	/* characters after src that are used */
9549     char_u	**fnamep,	/* file name so far */
9550     char_u	**bufp,		/* buffer for allocated file name or NULL */
9551     int		*fnamelen)	/* length of fnamep */
9552 {
9553     int		valid = 0;
9554     char_u	*tail;
9555     char_u	*s, *p, *pbuf;
9556     char_u	dirname[MAXPATHL];
9557     int		c;
9558     int		has_fullname = 0;
9559 #ifdef WIN3264
9560     char_u	*fname_start = *fnamep;
9561     int		has_shortname = 0;
9562 #endif
9563 
9564 repeat:
9565     /* ":p" - full path/file_name */
9566     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'p')
9567     {
9568 	has_fullname = 1;
9569 
9570 	valid |= VALID_PATH;
9571 	*usedlen += 2;
9572 
9573 	/* Expand "~/path" for all systems and "~user/path" for Unix and VMS */
9574 	if ((*fnamep)[0] == '~'
9575 #if !defined(UNIX) && !(defined(VMS) && defined(USER_HOME))
9576 		&& ((*fnamep)[1] == '/'
9577 # ifdef BACKSLASH_IN_FILENAME
9578 		    || (*fnamep)[1] == '\\'
9579 # endif
9580 		    || (*fnamep)[1] == NUL)
9581 
9582 #endif
9583 	   )
9584 	{
9585 	    *fnamep = expand_env_save(*fnamep);
9586 	    vim_free(*bufp);	/* free any allocated file name */
9587 	    *bufp = *fnamep;
9588 	    if (*fnamep == NULL)
9589 		return -1;
9590 	}
9591 
9592 	/* When "/." or "/.." is used: force expansion to get rid of it. */
9593 	for (p = *fnamep; *p != NUL; MB_PTR_ADV(p))
9594 	{
9595 	    if (vim_ispathsep(*p)
9596 		    && p[1] == '.'
9597 		    && (p[2] == NUL
9598 			|| vim_ispathsep(p[2])
9599 			|| (p[2] == '.'
9600 			    && (p[3] == NUL || vim_ispathsep(p[3])))))
9601 		break;
9602 	}
9603 
9604 	/* FullName_save() is slow, don't use it when not needed. */
9605 	if (*p != NUL || !vim_isAbsName(*fnamep))
9606 	{
9607 	    *fnamep = FullName_save(*fnamep, *p != NUL);
9608 	    vim_free(*bufp);	/* free any allocated file name */
9609 	    *bufp = *fnamep;
9610 	    if (*fnamep == NULL)
9611 		return -1;
9612 	}
9613 
9614 #ifdef WIN3264
9615 # if _WIN32_WINNT >= 0x0500
9616 	if (vim_strchr(*fnamep, '~') != NULL)
9617 	{
9618 	    /* Expand 8.3 filename to full path.  Needed to make sure the same
9619 	     * file does not have two different names.
9620 	     * Note: problem does not occur if _WIN32_WINNT < 0x0500. */
9621 	    p = alloc(_MAX_PATH + 1);
9622 	    if (p != NULL)
9623 	    {
9624 		if (GetLongPathName((LPSTR)*fnamep, (LPSTR)p, _MAX_PATH))
9625 		{
9626 		    vim_free(*bufp);
9627 		    *bufp = *fnamep = p;
9628 		}
9629 		else
9630 		    vim_free(p);
9631 	    }
9632 	}
9633 # endif
9634 #endif
9635 	/* Append a path separator to a directory. */
9636 	if (mch_isdir(*fnamep))
9637 	{
9638 	    /* Make room for one or two extra characters. */
9639 	    *fnamep = vim_strnsave(*fnamep, (int)STRLEN(*fnamep) + 2);
9640 	    vim_free(*bufp);	/* free any allocated file name */
9641 	    *bufp = *fnamep;
9642 	    if (*fnamep == NULL)
9643 		return -1;
9644 	    add_pathsep(*fnamep);
9645 	}
9646     }
9647 
9648     /* ":." - path relative to the current directory */
9649     /* ":~" - path relative to the home directory */
9650     /* ":8" - shortname path - postponed till after */
9651     while (src[*usedlen] == ':'
9652 		  && ((c = src[*usedlen + 1]) == '.' || c == '~' || c == '8'))
9653     {
9654 	*usedlen += 2;
9655 	if (c == '8')
9656 	{
9657 #ifdef WIN3264
9658 	    has_shortname = 1; /* Postpone this. */
9659 #endif
9660 	    continue;
9661 	}
9662 	pbuf = NULL;
9663 	/* Need full path first (use expand_env() to remove a "~/") */
9664 	if (!has_fullname)
9665 	{
9666 	    if (c == '.' && **fnamep == '~')
9667 		p = pbuf = expand_env_save(*fnamep);
9668 	    else
9669 		p = pbuf = FullName_save(*fnamep, FALSE);
9670 	}
9671 	else
9672 	    p = *fnamep;
9673 
9674 	has_fullname = 0;
9675 
9676 	if (p != NULL)
9677 	{
9678 	    if (c == '.')
9679 	    {
9680 		mch_dirname(dirname, MAXPATHL);
9681 		s = shorten_fname(p, dirname);
9682 		if (s != NULL)
9683 		{
9684 		    *fnamep = s;
9685 		    if (pbuf != NULL)
9686 		    {
9687 			vim_free(*bufp);   /* free any allocated file name */
9688 			*bufp = pbuf;
9689 			pbuf = NULL;
9690 		    }
9691 		}
9692 	    }
9693 	    else
9694 	    {
9695 		home_replace(NULL, p, dirname, MAXPATHL, TRUE);
9696 		/* Only replace it when it starts with '~' */
9697 		if (*dirname == '~')
9698 		{
9699 		    s = vim_strsave(dirname);
9700 		    if (s != NULL)
9701 		    {
9702 			*fnamep = s;
9703 			vim_free(*bufp);
9704 			*bufp = s;
9705 		    }
9706 		}
9707 	    }
9708 	    vim_free(pbuf);
9709 	}
9710     }
9711 
9712     tail = gettail(*fnamep);
9713     *fnamelen = (int)STRLEN(*fnamep);
9714 
9715     /* ":h" - head, remove "/file_name", can be repeated  */
9716     /* Don't remove the first "/" or "c:\" */
9717     while (src[*usedlen] == ':' && src[*usedlen + 1] == 'h')
9718     {
9719 	valid |= VALID_HEAD;
9720 	*usedlen += 2;
9721 	s = get_past_head(*fnamep);
9722 	while (tail > s && after_pathsep(s, tail))
9723 	    MB_PTR_BACK(*fnamep, tail);
9724 	*fnamelen = (int)(tail - *fnamep);
9725 #ifdef VMS
9726 	if (*fnamelen > 0)
9727 	    *fnamelen += 1; /* the path separator is part of the path */
9728 #endif
9729 	if (*fnamelen == 0)
9730 	{
9731 	    /* Result is empty.  Turn it into "." to make ":cd %:h" work. */
9732 	    p = vim_strsave((char_u *)".");
9733 	    if (p == NULL)
9734 		return -1;
9735 	    vim_free(*bufp);
9736 	    *bufp = *fnamep = tail = p;
9737 	    *fnamelen = 1;
9738 	}
9739 	else
9740 	{
9741 	    while (tail > s && !after_pathsep(s, tail))
9742 		MB_PTR_BACK(*fnamep, tail);
9743 	}
9744     }
9745 
9746     /* ":8" - shortname  */
9747     if (src[*usedlen] == ':' && src[*usedlen + 1] == '8')
9748     {
9749 	*usedlen += 2;
9750 #ifdef WIN3264
9751 	has_shortname = 1;
9752 #endif
9753     }
9754 
9755 #ifdef WIN3264
9756     /*
9757      * Handle ":8" after we have done 'heads' and before we do 'tails'.
9758      */
9759     if (has_shortname)
9760     {
9761 	/* Copy the string if it is shortened by :h and when it wasn't copied
9762 	 * yet, because we are going to change it in place.  Avoids changing
9763 	 * the buffer name for "%:8". */
9764 	if (*fnamelen < (int)STRLEN(*fnamep) || *fnamep == fname_start)
9765 	{
9766 	    p = vim_strnsave(*fnamep, *fnamelen);
9767 	    if (p == NULL)
9768 		return -1;
9769 	    vim_free(*bufp);
9770 	    *bufp = *fnamep = p;
9771 	}
9772 
9773 	/* Split into two implementations - makes it easier.  First is where
9774 	 * there isn't a full name already, second is where there is. */
9775 	if (!has_fullname && !vim_isAbsName(*fnamep))
9776 	{
9777 	    if (shortpath_for_partial(fnamep, bufp, fnamelen) == FAIL)
9778 		return -1;
9779 	}
9780 	else
9781 	{
9782 	    int		l = *fnamelen;
9783 
9784 	    /* Simple case, already have the full-name.
9785 	     * Nearly always shorter, so try first time. */
9786 	    if (get_short_pathname(fnamep, bufp, &l) == FAIL)
9787 		return -1;
9788 
9789 	    if (l == 0)
9790 	    {
9791 		/* Couldn't find the filename, search the paths. */
9792 		l = *fnamelen;
9793 		if (shortpath_for_invalid_fname(fnamep, bufp, &l) == FAIL)
9794 		    return -1;
9795 	    }
9796 	    *fnamelen = l;
9797 	}
9798     }
9799 #endif /* WIN3264 */
9800 
9801     /* ":t" - tail, just the basename */
9802     if (src[*usedlen] == ':' && src[*usedlen + 1] == 't')
9803     {
9804 	*usedlen += 2;
9805 	*fnamelen -= (int)(tail - *fnamep);
9806 	*fnamep = tail;
9807     }
9808 
9809     /* ":e" - extension, can be repeated */
9810     /* ":r" - root, without extension, can be repeated */
9811     while (src[*usedlen] == ':'
9812 	    && (src[*usedlen + 1] == 'e' || src[*usedlen + 1] == 'r'))
9813     {
9814 	/* find a '.' in the tail:
9815 	 * - for second :e: before the current fname
9816 	 * - otherwise: The last '.'
9817 	 */
9818 	if (src[*usedlen + 1] == 'e' && *fnamep > tail)
9819 	    s = *fnamep - 2;
9820 	else
9821 	    s = *fnamep + *fnamelen - 1;
9822 	for ( ; s > tail; --s)
9823 	    if (s[0] == '.')
9824 		break;
9825 	if (src[*usedlen + 1] == 'e')		/* :e */
9826 	{
9827 	    if (s > tail)
9828 	    {
9829 		*fnamelen += (int)(*fnamep - (s + 1));
9830 		*fnamep = s + 1;
9831 #ifdef VMS
9832 		/* cut version from the extension */
9833 		s = *fnamep + *fnamelen - 1;
9834 		for ( ; s > *fnamep; --s)
9835 		    if (s[0] == ';')
9836 			break;
9837 		if (s > *fnamep)
9838 		    *fnamelen = s - *fnamep;
9839 #endif
9840 	    }
9841 	    else if (*fnamep <= tail)
9842 		*fnamelen = 0;
9843 	}
9844 	else				/* :r */
9845 	{
9846 	    if (s > tail)	/* remove one extension */
9847 		*fnamelen = (int)(s - *fnamep);
9848 	}
9849 	*usedlen += 2;
9850     }
9851 
9852     /* ":s?pat?foo?" - substitute */
9853     /* ":gs?pat?foo?" - global substitute */
9854     if (src[*usedlen] == ':'
9855 	    && (src[*usedlen + 1] == 's'
9856 		|| (src[*usedlen + 1] == 'g' && src[*usedlen + 2] == 's')))
9857     {
9858 	char_u	    *str;
9859 	char_u	    *pat;
9860 	char_u	    *sub;
9861 	int	    sep;
9862 	char_u	    *flags;
9863 	int	    didit = FALSE;
9864 
9865 	flags = (char_u *)"";
9866 	s = src + *usedlen + 2;
9867 	if (src[*usedlen + 1] == 'g')
9868 	{
9869 	    flags = (char_u *)"g";
9870 	    ++s;
9871 	}
9872 
9873 	sep = *s++;
9874 	if (sep)
9875 	{
9876 	    /* find end of pattern */
9877 	    p = vim_strchr(s, sep);
9878 	    if (p != NULL)
9879 	    {
9880 		pat = vim_strnsave(s, (int)(p - s));
9881 		if (pat != NULL)
9882 		{
9883 		    s = p + 1;
9884 		    /* find end of substitution */
9885 		    p = vim_strchr(s, sep);
9886 		    if (p != NULL)
9887 		    {
9888 			sub = vim_strnsave(s, (int)(p - s));
9889 			str = vim_strnsave(*fnamep, *fnamelen);
9890 			if (sub != NULL && str != NULL)
9891 			{
9892 			    *usedlen = (int)(p + 1 - src);
9893 			    s = do_string_sub(str, pat, sub, NULL, flags);
9894 			    if (s != NULL)
9895 			    {
9896 				*fnamep = s;
9897 				*fnamelen = (int)STRLEN(s);
9898 				vim_free(*bufp);
9899 				*bufp = s;
9900 				didit = TRUE;
9901 			    }
9902 			}
9903 			vim_free(sub);
9904 			vim_free(str);
9905 		    }
9906 		    vim_free(pat);
9907 		}
9908 	    }
9909 	    /* after using ":s", repeat all the modifiers */
9910 	    if (didit)
9911 		goto repeat;
9912 	}
9913     }
9914 
9915     if (src[*usedlen] == ':' && src[*usedlen + 1] == 'S')
9916     {
9917 	/* vim_strsave_shellescape() needs a NUL terminated string. */
9918 	c = (*fnamep)[*fnamelen];
9919 	if (c != NUL)
9920 	    (*fnamep)[*fnamelen] = NUL;
9921 	p = vim_strsave_shellescape(*fnamep, FALSE, FALSE);
9922 	if (c != NUL)
9923 	    (*fnamep)[*fnamelen] = c;
9924 	if (p == NULL)
9925 	    return -1;
9926 	vim_free(*bufp);
9927 	*bufp = *fnamep = p;
9928 	*fnamelen = (int)STRLEN(p);
9929 	*usedlen += 2;
9930     }
9931 
9932     return valid;
9933 }
9934 
9935 /*
9936  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
9937  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
9938  * "flags" can be "g" to do a global substitute.
9939  * Returns an allocated string, NULL for error.
9940  */
9941     char_u *
9942 do_string_sub(
9943     char_u	*str,
9944     char_u	*pat,
9945     char_u	*sub,
9946     typval_T	*expr,
9947     char_u	*flags)
9948 {
9949     int		sublen;
9950     regmatch_T	regmatch;
9951     int		i;
9952     int		do_all;
9953     char_u	*tail;
9954     char_u	*end;
9955     garray_T	ga;
9956     char_u	*ret;
9957     char_u	*save_cpo;
9958     char_u	*zero_width = NULL;
9959 
9960     /* Make 'cpoptions' empty, so that the 'l' flag doesn't work here */
9961     save_cpo = p_cpo;
9962     p_cpo = empty_option;
9963 
9964     ga_init2(&ga, 1, 200);
9965 
9966     do_all = (flags[0] == 'g');
9967 
9968     regmatch.rm_ic = p_ic;
9969     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
9970     if (regmatch.regprog != NULL)
9971     {
9972 	tail = str;
9973 	end = str + STRLEN(str);
9974 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
9975 	{
9976 	    /* Skip empty match except for first match. */
9977 	    if (regmatch.startp[0] == regmatch.endp[0])
9978 	    {
9979 		if (zero_width == regmatch.startp[0])
9980 		{
9981 		    /* avoid getting stuck on a match with an empty string */
9982 		    i = MB_PTR2LEN(tail);
9983 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
9984 								   (size_t)i);
9985 		    ga.ga_len += i;
9986 		    tail += i;
9987 		    continue;
9988 		}
9989 		zero_width = regmatch.startp[0];
9990 	    }
9991 
9992 	    /*
9993 	     * Get some space for a temporary buffer to do the substitution
9994 	     * into.  It will contain:
9995 	     * - The text up to where the match is.
9996 	     * - The substituted text.
9997 	     * - The text after the match.
9998 	     */
9999 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
10000 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
10001 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
10002 	    {
10003 		ga_clear(&ga);
10004 		break;
10005 	    }
10006 
10007 	    /* copy the text up to where the match is */
10008 	    i = (int)(regmatch.startp[0] - tail);
10009 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
10010 	    /* add the substituted text */
10011 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
10012 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
10013 	    ga.ga_len += i + sublen - 1;
10014 	    tail = regmatch.endp[0];
10015 	    if (*tail == NUL)
10016 		break;
10017 	    if (!do_all)
10018 		break;
10019 	}
10020 
10021 	if (ga.ga_data != NULL)
10022 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
10023 
10024 	vim_regfree(regmatch.regprog);
10025     }
10026 
10027     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
10028     ga_clear(&ga);
10029     if (p_cpo == empty_option)
10030 	p_cpo = save_cpo;
10031     else
10032 	/* Darn, evaluating {sub} expression or {expr} changed the value. */
10033 	free_string_option(save_cpo);
10034 
10035     return ret;
10036 }
10037 
10038     static int
10039 filter_map_one(typval_T *tv, typval_T *expr, int map, int *remp)
10040 {
10041     typval_T	rettv;
10042     typval_T	argv[3];
10043     int		retval = FAIL;
10044 
10045     copy_tv(tv, &vimvars[VV_VAL].vv_tv);
10046     argv[0] = vimvars[VV_KEY].vv_tv;
10047     argv[1] = vimvars[VV_VAL].vv_tv;
10048     if (eval_expr_typval(expr, argv, 2, &rettv) == FAIL)
10049 	goto theend;
10050     if (map)
10051     {
10052 	/* map(): replace the list item value */
10053 	clear_tv(tv);
10054 	rettv.v_lock = 0;
10055 	*tv = rettv;
10056     }
10057     else
10058     {
10059 	int	    error = FALSE;
10060 
10061 	/* filter(): when expr is zero remove the item */
10062 	*remp = (get_tv_number_chk(&rettv, &error) == 0);
10063 	clear_tv(&rettv);
10064 	/* On type error, nothing has been removed; return FAIL to stop the
10065 	 * loop.  The error message was given by get_tv_number_chk(). */
10066 	if (error)
10067 	    goto theend;
10068     }
10069     retval = OK;
10070 theend:
10071     clear_tv(&vimvars[VV_VAL].vv_tv);
10072     return retval;
10073 }
10074 
10075 
10076 /*
10077  * Implementation of map() and filter().
10078  */
10079     void
10080 filter_map(typval_T *argvars, typval_T *rettv, int map)
10081 {
10082     typval_T	*expr;
10083     listitem_T	*li, *nli;
10084     list_T	*l = NULL;
10085     dictitem_T	*di;
10086     hashtab_T	*ht;
10087     hashitem_T	*hi;
10088     dict_T	*d = NULL;
10089     typval_T	save_val;
10090     typval_T	save_key;
10091     int		rem;
10092     int		todo;
10093     char_u	*ermsg = (char_u *)(map ? "map()" : "filter()");
10094     char_u	*arg_errmsg = (char_u *)(map ? N_("map() argument")
10095 				   : N_("filter() argument"));
10096     int		save_did_emsg;
10097     int		idx = 0;
10098 
10099     if (argvars[0].v_type == VAR_LIST)
10100     {
10101 	if ((l = argvars[0].vval.v_list) == NULL
10102 	      || (!map && tv_check_lock(l->lv_lock, arg_errmsg, TRUE)))
10103 	    return;
10104     }
10105     else if (argvars[0].v_type == VAR_DICT)
10106     {
10107 	if ((d = argvars[0].vval.v_dict) == NULL
10108 	      || (!map && tv_check_lock(d->dv_lock, arg_errmsg, TRUE)))
10109 	    return;
10110     }
10111     else
10112     {
10113 	EMSG2(_(e_listdictarg), ermsg);
10114 	return;
10115     }
10116 
10117     expr = &argvars[1];
10118     /* On type errors, the preceding call has already displayed an error
10119      * message.  Avoid a misleading error message for an empty string that
10120      * was not passed as argument. */
10121     if (expr->v_type != VAR_UNKNOWN)
10122     {
10123 	prepare_vimvar(VV_VAL, &save_val);
10124 
10125 	/* We reset "did_emsg" to be able to detect whether an error
10126 	 * occurred during evaluation of the expression. */
10127 	save_did_emsg = did_emsg;
10128 	did_emsg = FALSE;
10129 
10130 	prepare_vimvar(VV_KEY, &save_key);
10131 	if (argvars[0].v_type == VAR_DICT)
10132 	{
10133 	    vimvars[VV_KEY].vv_type = VAR_STRING;
10134 
10135 	    ht = &d->dv_hashtab;
10136 	    hash_lock(ht);
10137 	    todo = (int)ht->ht_used;
10138 	    for (hi = ht->ht_array; todo > 0; ++hi)
10139 	    {
10140 		if (!HASHITEM_EMPTY(hi))
10141 		{
10142 		    int r;
10143 
10144 		    --todo;
10145 		    di = HI2DI(hi);
10146 		    if (map &&
10147 			    (tv_check_lock(di->di_tv.v_lock, arg_errmsg, TRUE)
10148 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE)))
10149 			break;
10150 		    vimvars[VV_KEY].vv_str = vim_strsave(di->di_key);
10151 		    r = filter_map_one(&di->di_tv, expr, map, &rem);
10152 		    clear_tv(&vimvars[VV_KEY].vv_tv);
10153 		    if (r == FAIL || did_emsg)
10154 			break;
10155 		    if (!map && rem)
10156 		    {
10157 			if (var_check_fixed(di->di_flags, arg_errmsg, TRUE)
10158 			    || var_check_ro(di->di_flags, arg_errmsg, TRUE))
10159 			    break;
10160 			dictitem_remove(d, di);
10161 		    }
10162 		}
10163 	    }
10164 	    hash_unlock(ht);
10165 	}
10166 	else
10167 	{
10168 	    vimvars[VV_KEY].vv_type = VAR_NUMBER;
10169 
10170 	    for (li = l->lv_first; li != NULL; li = nli)
10171 	    {
10172 		if (map && tv_check_lock(li->li_tv.v_lock, arg_errmsg, TRUE))
10173 		    break;
10174 		nli = li->li_next;
10175 		vimvars[VV_KEY].vv_nr = idx;
10176 		if (filter_map_one(&li->li_tv, expr, map, &rem) == FAIL
10177 								  || did_emsg)
10178 		    break;
10179 		if (!map && rem)
10180 		    listitem_remove(l, li);
10181 		++idx;
10182 	    }
10183 	}
10184 
10185 	restore_vimvar(VV_KEY, &save_key);
10186 	restore_vimvar(VV_VAL, &save_val);
10187 
10188 	did_emsg |= save_did_emsg;
10189     }
10190 
10191     copy_tv(&argvars[0], rettv);
10192 }
10193 
10194 #endif /* defined(FEAT_MODIFY_FNAME) || defined(FEAT_EVAL) */
10195