xref: /vim-8.2.3635/src/eval.c (revision e71ebb46)
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 static char *e_dictrange = N_("E719: Cannot use [:] with a Dictionary");
24 #ifdef FEAT_FLOAT
25 static char *e_float_as_string = N_("E806: using Float as a String");
26 #endif
27 
28 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
29 
30 /*
31  * When recursively copying lists and dicts we need to remember which ones we
32  * have done to avoid endless recursiveness.  This unique ID is used for that.
33  * The last bit is used for previous_funccal, ignored when comparing.
34  */
35 static int current_copyID = 0;
36 
37 /*
38  * Info used by a ":for" loop.
39  */
40 typedef struct
41 {
42     int		fi_semicolon;	// TRUE if ending in '; var]'
43     int		fi_varcount;	// nr of variables in the list
44     listwatch_T	fi_lw;		// keep an eye on the item used.
45     list_T	*fi_list;	// list being used
46     int		fi_bi;		// index of blob
47     blob_T	*fi_blob;	// blob being used
48 } forinfo_T;
49 
50 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
51 static int eval2(char_u **arg, typval_T *rettv, int evaluate);
52 static int eval3(char_u **arg, typval_T *rettv, int evaluate);
53 static int eval4(char_u **arg, typval_T *rettv, int evaluate);
54 static int eval5(char_u **arg, typval_T *rettv, int evaluate);
55 static int eval6(char_u **arg, typval_T *rettv, int evaluate, int want_string);
56 static int eval7(char_u **arg, typval_T *rettv, int evaluate, int want_string);
57 static int eval7_leader(typval_T *rettv, char_u *start_leader, char_u **end_leaderp);
58 
59 static int free_unref_items(int copyID);
60 static char_u *make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
61 static int tv_check_lock(typval_T *tv, char_u *name, int use_gettext);
62 
63 /*
64  * Return "n1" divided by "n2", taking care of dividing by zero.
65  */
66 	varnumber_T
67 num_divide(varnumber_T n1, varnumber_T n2)
68 {
69     varnumber_T	result;
70 
71     if (n2 == 0)	// give an error message?
72     {
73 	if (n1 == 0)
74 	    result = VARNUM_MIN; // similar to NaN
75 	else if (n1 < 0)
76 	    result = -VARNUM_MAX;
77 	else
78 	    result = VARNUM_MAX;
79     }
80     else
81 	result = n1 / n2;
82 
83     return result;
84 }
85 
86 /*
87  * Return "n1" modulus "n2", taking care of dividing by zero.
88  */
89 	varnumber_T
90 num_modulus(varnumber_T n1, varnumber_T n2)
91 {
92     // Give an error when n2 is 0?
93     return (n2 == 0) ? 0 : (n1 % n2);
94 }
95 
96 #if defined(EBCDIC) || defined(PROTO)
97 /*
98  * Compare struct fst by function name.
99  */
100     static int
101 compare_func_name(const void *s1, const void *s2)
102 {
103     struct fst *p1 = (struct fst *)s1;
104     struct fst *p2 = (struct fst *)s2;
105 
106     return STRCMP(p1->f_name, p2->f_name);
107 }
108 
109 /*
110  * Sort the function table by function name.
111  * The sorting of the table above is ASCII dependent.
112  * On machines using EBCDIC we have to sort it.
113  */
114     static void
115 sortFunctions(void)
116 {
117     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
118 
119     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
120 }
121 #endif
122 
123 /*
124  * Initialize the global and v: variables.
125  */
126     void
127 eval_init(void)
128 {
129     evalvars_init();
130     func_init();
131 
132 #ifdef EBCDIC
133     /*
134      * Sort the function table, to enable binary search.
135      */
136     sortFunctions();
137 #endif
138 }
139 
140 #if defined(EXITFREE) || defined(PROTO)
141     void
142 eval_clear(void)
143 {
144     evalvars_clear();
145     free_scriptnames();  // must come after evalvars_clear().
146     free_locales();
147 
148     // autoloaded script names
149     free_autoload_scriptnames();
150 
151     // unreferenced lists and dicts
152     (void)garbage_collect(FALSE);
153 
154     // functions not garbage collected
155     free_all_functions();
156 }
157 #endif
158 
159 /*
160  * Top level evaluation function, returning a boolean.
161  * Sets "error" to TRUE if there was an error.
162  * Return TRUE or FALSE.
163  */
164     int
165 eval_to_bool(
166     char_u	*arg,
167     int		*error,
168     char_u	**nextcmd,
169     int		skip)	    // only parse, don't execute
170 {
171     typval_T	tv;
172     varnumber_T	retval = FALSE;
173 
174     if (skip)
175 	++emsg_skip;
176     if (eval0(arg, &tv, nextcmd, !skip) == FAIL)
177 	*error = TRUE;
178     else
179     {
180 	*error = FALSE;
181 	if (!skip)
182 	{
183 	    retval = (tv_get_number_chk(&tv, error) != 0);
184 	    clear_tv(&tv);
185 	}
186     }
187     if (skip)
188 	--emsg_skip;
189 
190     return (int)retval;
191 }
192 
193 /*
194  * Call eval1() and give an error message if not done at a lower level.
195  */
196     static int
197 eval1_emsg(char_u **arg, typval_T *rettv, int evaluate)
198 {
199     char_u	*start = *arg;
200     int		ret;
201     int		did_emsg_before = did_emsg;
202     int		called_emsg_before = called_emsg;
203 
204     ret = eval1(arg, rettv, evaluate);
205     if (ret == FAIL)
206     {
207 	// Report the invalid expression unless the expression evaluation has
208 	// been cancelled due to an aborting error, an interrupt, or an
209 	// exception, or we already gave a more specific error.
210 	// Also check called_emsg for when using assert_fails().
211 	if (!aborting() && did_emsg == did_emsg_before
212 					  && called_emsg == called_emsg_before)
213 	    semsg(_(e_invexpr2), start);
214     }
215     return ret;
216 }
217 
218 /*
219  * Evaluate an expression, which can be a function, partial or string.
220  * Pass arguments "argv[argc]".
221  * Return the result in "rettv" and OK or FAIL.
222  */
223     int
224 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
225 {
226     char_u	*s;
227     char_u	buf[NUMBUFLEN];
228     funcexe_T	funcexe;
229 
230     if (expr->v_type == VAR_FUNC)
231     {
232 	s = expr->vval.v_string;
233 	if (s == NULL || *s == NUL)
234 	    return FAIL;
235 	CLEAR_FIELD(funcexe);
236 	funcexe.evaluate = TRUE;
237 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
238 	    return FAIL;
239     }
240     else if (expr->v_type == VAR_PARTIAL)
241     {
242 	partial_T   *partial = expr->vval.v_partial;
243 
244 	if (partial->pt_func != NULL && partial->pt_func->uf_dfunc_idx >= 0)
245 	{
246 	    if (call_def_function(partial->pt_func, argc, argv, rettv) == FAIL)
247 		return FAIL;
248 	}
249 	else
250 	{
251 	    s = partial_name(partial);
252 	    if (s == NULL || *s == NUL)
253 		return FAIL;
254 	    CLEAR_FIELD(funcexe);
255 	    funcexe.evaluate = TRUE;
256 	    funcexe.partial = partial;
257 	    if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
258 		return FAIL;
259 	}
260     }
261     else
262     {
263 	s = tv_get_string_buf_chk(expr, buf);
264 	if (s == NULL)
265 	    return FAIL;
266 	s = skipwhite(s);
267 	if (eval1_emsg(&s, rettv, TRUE) == FAIL)
268 	    return FAIL;
269 	if (*s != NUL)  // check for trailing chars after expr
270 	{
271 	    clear_tv(rettv);
272 	    semsg(_(e_invexpr2), s);
273 	    return FAIL;
274 	}
275     }
276     return OK;
277 }
278 
279 /*
280  * Like eval_to_bool() but using a typval_T instead of a string.
281  * Works for string, funcref and partial.
282  */
283     int
284 eval_expr_to_bool(typval_T *expr, int *error)
285 {
286     typval_T	rettv;
287     int		res;
288 
289     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
290     {
291 	*error = TRUE;
292 	return FALSE;
293     }
294     res = (tv_get_number_chk(&rettv, error) != 0);
295     clear_tv(&rettv);
296     return res;
297 }
298 
299 /*
300  * Top level evaluation function, returning a string.  If "skip" is TRUE,
301  * only parsing to "nextcmd" is done, without reporting errors.  Return
302  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
303  */
304     char_u *
305 eval_to_string_skip(
306     char_u	*arg,
307     char_u	**nextcmd,
308     int		skip)	    // only parse, don't execute
309 {
310     typval_T	tv;
311     char_u	*retval;
312 
313     if (skip)
314 	++emsg_skip;
315     if (eval0(arg, &tv, nextcmd, !skip) == FAIL || skip)
316 	retval = NULL;
317     else
318     {
319 	retval = vim_strsave(tv_get_string(&tv));
320 	clear_tv(&tv);
321     }
322     if (skip)
323 	--emsg_skip;
324 
325     return retval;
326 }
327 
328 /*
329  * Skip over an expression at "*pp".
330  * Return FAIL for an error, OK otherwise.
331  */
332     int
333 skip_expr(char_u **pp)
334 {
335     typval_T	rettv;
336 
337     *pp = skipwhite(*pp);
338     return eval1(pp, &rettv, FALSE);
339 }
340 
341 /*
342  * Top level evaluation function, returning a string.
343  * When "convert" is TRUE convert a List into a sequence of lines and convert
344  * a Float to a String.
345  * Return pointer to allocated memory, or NULL for failure.
346  */
347     char_u *
348 eval_to_string(
349     char_u	*arg,
350     char_u	**nextcmd,
351     int		convert)
352 {
353     typval_T	tv;
354     char_u	*retval;
355     garray_T	ga;
356 #ifdef FEAT_FLOAT
357     char_u	numbuf[NUMBUFLEN];
358 #endif
359 
360     if (eval0(arg, &tv, nextcmd, TRUE) == FAIL)
361 	retval = NULL;
362     else
363     {
364 	if (convert && tv.v_type == VAR_LIST)
365 	{
366 	    ga_init2(&ga, (int)sizeof(char), 80);
367 	    if (tv.vval.v_list != NULL)
368 	    {
369 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
370 		if (tv.vval.v_list->lv_len > 0)
371 		    ga_append(&ga, NL);
372 	    }
373 	    ga_append(&ga, NUL);
374 	    retval = (char_u *)ga.ga_data;
375 	}
376 #ifdef FEAT_FLOAT
377 	else if (convert && tv.v_type == VAR_FLOAT)
378 	{
379 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
380 	    retval = vim_strsave(numbuf);
381 	}
382 #endif
383 	else
384 	    retval = vim_strsave(tv_get_string(&tv));
385 	clear_tv(&tv);
386     }
387 
388     return retval;
389 }
390 
391 /*
392  * Call eval_to_string() without using current local variables and using
393  * textlock.  When "use_sandbox" is TRUE use the sandbox.
394  */
395     char_u *
396 eval_to_string_safe(
397     char_u	*arg,
398     char_u	**nextcmd,
399     int		use_sandbox)
400 {
401     char_u	*retval;
402     funccal_entry_T funccal_entry;
403 
404     save_funccal(&funccal_entry);
405     if (use_sandbox)
406 	++sandbox;
407     ++textlock;
408     retval = eval_to_string(arg, nextcmd, FALSE);
409     if (use_sandbox)
410 	--sandbox;
411     --textlock;
412     restore_funccal();
413     return retval;
414 }
415 
416 /*
417  * Top level evaluation function, returning a number.
418  * Evaluates "expr" silently.
419  * Returns -1 for an error.
420  */
421     varnumber_T
422 eval_to_number(char_u *expr)
423 {
424     typval_T	rettv;
425     varnumber_T	retval;
426     char_u	*p = skipwhite(expr);
427 
428     ++emsg_off;
429 
430     if (eval1(&p, &rettv, TRUE) == FAIL)
431 	retval = -1;
432     else
433     {
434 	retval = tv_get_number_chk(&rettv, NULL);
435 	clear_tv(&rettv);
436     }
437     --emsg_off;
438 
439     return retval;
440 }
441 
442 /*
443  * Top level evaluation function.
444  * Returns an allocated typval_T with the result.
445  * Returns NULL when there is an error.
446  */
447     typval_T *
448 eval_expr(char_u *arg, char_u **nextcmd)
449 {
450     typval_T	*tv;
451 
452     tv = ALLOC_ONE(typval_T);
453     if (tv != NULL && eval0(arg, tv, nextcmd, TRUE) == FAIL)
454 	VIM_CLEAR(tv);
455 
456     return tv;
457 }
458 
459 /*
460  * Call some Vim script function and return the result in "*rettv".
461  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
462  * should have type VAR_UNKNOWN.
463  * Returns OK or FAIL.
464  */
465     int
466 call_vim_function(
467     char_u      *func,
468     int		argc,
469     typval_T	*argv,
470     typval_T	*rettv)
471 {
472     int		ret;
473     funcexe_T	funcexe;
474 
475     rettv->v_type = VAR_UNKNOWN;		// clear_tv() uses this
476     CLEAR_FIELD(funcexe);
477     funcexe.firstline = curwin->w_cursor.lnum;
478     funcexe.lastline = curwin->w_cursor.lnum;
479     funcexe.evaluate = TRUE;
480     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
481     if (ret == FAIL)
482 	clear_tv(rettv);
483 
484     return ret;
485 }
486 
487 /*
488  * Call Vim script function "func" and return the result as a number.
489  * Returns -1 when calling the function fails.
490  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
491  * have type VAR_UNKNOWN.
492  */
493     varnumber_T
494 call_func_retnr(
495     char_u      *func,
496     int		argc,
497     typval_T	*argv)
498 {
499     typval_T	rettv;
500     varnumber_T	retval;
501 
502     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
503 	return -1;
504 
505     retval = tv_get_number_chk(&rettv, NULL);
506     clear_tv(&rettv);
507     return retval;
508 }
509 
510 /*
511  * Call Vim script function "func" and return the result as a string.
512  * Returns NULL when calling the function fails.
513  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
514  * have type VAR_UNKNOWN.
515  */
516     void *
517 call_func_retstr(
518     char_u      *func,
519     int		argc,
520     typval_T	*argv)
521 {
522     typval_T	rettv;
523     char_u	*retval;
524 
525     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
526 	return NULL;
527 
528     retval = vim_strsave(tv_get_string(&rettv));
529     clear_tv(&rettv);
530     return retval;
531 }
532 
533 /*
534  * Call Vim script function "func" and return the result as a List.
535  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
536  * have type VAR_UNKNOWN.
537  * Returns NULL when there is something wrong.
538  */
539     void *
540 call_func_retlist(
541     char_u      *func,
542     int		argc,
543     typval_T	*argv)
544 {
545     typval_T	rettv;
546 
547     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
548 	return NULL;
549 
550     if (rettv.v_type != VAR_LIST)
551     {
552 	clear_tv(&rettv);
553 	return NULL;
554     }
555 
556     return rettv.vval.v_list;
557 }
558 
559 #ifdef FEAT_FOLDING
560 /*
561  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
562  * it in "*cp".  Doesn't give error messages.
563  */
564     int
565 eval_foldexpr(char_u *arg, int *cp)
566 {
567     typval_T	tv;
568     varnumber_T	retval;
569     char_u	*s;
570     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
571 								   OPT_LOCAL);
572 
573     ++emsg_off;
574     if (use_sandbox)
575 	++sandbox;
576     ++textlock;
577     *cp = NUL;
578     if (eval0(arg, &tv, NULL, TRUE) == FAIL)
579 	retval = 0;
580     else
581     {
582 	// If the result is a number, just return the number.
583 	if (tv.v_type == VAR_NUMBER)
584 	    retval = tv.vval.v_number;
585 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
586 	    retval = 0;
587 	else
588 	{
589 	    // If the result is a string, check if there is a non-digit before
590 	    // the number.
591 	    s = tv.vval.v_string;
592 	    if (!VIM_ISDIGIT(*s) && *s != '-')
593 		*cp = *s++;
594 	    retval = atol((char *)s);
595 	}
596 	clear_tv(&tv);
597     }
598     --emsg_off;
599     if (use_sandbox)
600 	--sandbox;
601     --textlock;
602 
603     return (int)retval;
604 }
605 #endif
606 
607 /*
608  * Get an lval: variable, Dict item or List item that can be assigned a value
609  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
610  * "name.key", "name.key[expr]" etc.
611  * Indexing only works if "name" is an existing List or Dictionary.
612  * "name" points to the start of the name.
613  * If "rettv" is not NULL it points to the value to be assigned.
614  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
615  * wrong; must end in space or cmd separator.
616  *
617  * flags:
618  *  GLV_QUIET:       do not give error messages
619  *  GLV_READ_ONLY:   will not change the variable
620  *  GLV_NO_AUTOLOAD: do not use script autoloading
621  *
622  * Returns a pointer to just after the name, including indexes.
623  * When an evaluation error occurs "lp->ll_name" is NULL;
624  * Returns NULL for a parsing error.  Still need to free items in "lp"!
625  */
626     char_u *
627 get_lval(
628     char_u	*name,
629     typval_T	*rettv,
630     lval_T	*lp,
631     int		unlet,
632     int		skip,
633     int		flags,	    // GLV_ values
634     int		fne_flags)  // flags for find_name_end()
635 {
636     char_u	*p;
637     char_u	*expr_start, *expr_end;
638     int		cc;
639     dictitem_T	*v;
640     typval_T	var1;
641     typval_T	var2;
642     int		empty1 = FALSE;
643     listitem_T	*ni;
644     char_u	*key = NULL;
645     int		len;
646     hashtab_T	*ht;
647     int		quiet = flags & GLV_QUIET;
648 
649     // Clear everything in "lp".
650     CLEAR_POINTER(lp);
651 
652     if (skip)
653     {
654 	// When skipping just find the end of the name.
655 	lp->ll_name = name;
656 	return find_name_end(name, NULL, NULL, FNE_INCL_BR | fne_flags);
657     }
658 
659     // Find the end of the name.
660     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
661     lp->ll_name_end = p;
662     if (expr_start != NULL)
663     {
664 	// Don't expand the name when we already know there is an error.
665 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
666 						    && *p != '[' && *p != '.')
667 	{
668 	    emsg(_(e_trailing));
669 	    return NULL;
670 	}
671 
672 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
673 	if (lp->ll_exp_name == NULL)
674 	{
675 	    // Report an invalid expression in braces, unless the
676 	    // expression evaluation has been cancelled due to an
677 	    // aborting error, an interrupt, or an exception.
678 	    if (!aborting() && !quiet)
679 	    {
680 		emsg_severe = TRUE;
681 		semsg(_(e_invarg2), name);
682 		return NULL;
683 	    }
684 	}
685 	lp->ll_name = lp->ll_exp_name;
686     }
687     else
688     {
689 	lp->ll_name = name;
690 
691 	if (current_sctx.sc_version == SCRIPT_VERSION_VIM9 && *p == ':')
692 	{
693 	    scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);
694 	    char_u	 *tp = skipwhite(p + 1);
695 
696 	    // parse the type after the name
697 	    lp->ll_type = parse_type(&tp, &si->sn_type_list);
698 	    lp->ll_name_end = tp;
699 	}
700     }
701 
702     // Without [idx] or .key we are done.
703     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
704 	return p;
705 
706     cc = *p;
707     *p = NUL;
708     // Only pass &ht when we would write to the variable, it prevents autoload
709     // as well.
710     v = find_var(lp->ll_name, (flags & GLV_READ_ONLY) ? NULL : &ht,
711 						      flags & GLV_NO_AUTOLOAD);
712     if (v == NULL && !quiet)
713 	semsg(_(e_undefvar), lp->ll_name);
714     *p = cc;
715     if (v == NULL)
716 	return NULL;
717 
718     /*
719      * Loop until no more [idx] or .key is following.
720      */
721     lp->ll_tv = &v->di_tv;
722     var1.v_type = VAR_UNKNOWN;
723     var2.v_type = VAR_UNKNOWN;
724     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
725     {
726 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
727 		&& !(lp->ll_tv->v_type == VAR_DICT
728 					   && lp->ll_tv->vval.v_dict != NULL)
729 		&& !(lp->ll_tv->v_type == VAR_BLOB
730 					   && lp->ll_tv->vval.v_blob != NULL))
731 	{
732 	    if (!quiet)
733 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
734 	    return NULL;
735 	}
736 	if (lp->ll_range)
737 	{
738 	    if (!quiet)
739 		emsg(_("E708: [:] must come last"));
740 	    return NULL;
741 	}
742 
743 	len = -1;
744 	if (*p == '.')
745 	{
746 	    key = p + 1;
747 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
748 		;
749 	    if (len == 0)
750 	    {
751 		if (!quiet)
752 		    emsg(_(e_emptykey));
753 		return NULL;
754 	    }
755 	    p = key + len;
756 	}
757 	else
758 	{
759 	    // Get the index [expr] or the first index [expr: ].
760 	    p = skipwhite(p + 1);
761 	    if (*p == ':')
762 		empty1 = TRUE;
763 	    else
764 	    {
765 		empty1 = FALSE;
766 		if (eval1(&p, &var1, TRUE) == FAIL)	// recursive!
767 		    return NULL;
768 		if (tv_get_string_chk(&var1) == NULL)
769 		{
770 		    // not a number or string
771 		    clear_tv(&var1);
772 		    return NULL;
773 		}
774 	    }
775 
776 	    // Optionally get the second index [ :expr].
777 	    if (*p == ':')
778 	    {
779 		if (lp->ll_tv->v_type == VAR_DICT)
780 		{
781 		    if (!quiet)
782 			emsg(_(e_dictrange));
783 		    clear_tv(&var1);
784 		    return NULL;
785 		}
786 		if (rettv != NULL
787 			&& !(rettv->v_type == VAR_LIST
788 						 && rettv->vval.v_list != NULL)
789 			&& !(rettv->v_type == VAR_BLOB
790 						&& rettv->vval.v_blob != NULL))
791 		{
792 		    if (!quiet)
793 			emsg(_("E709: [:] requires a List or Blob value"));
794 		    clear_tv(&var1);
795 		    return NULL;
796 		}
797 		p = skipwhite(p + 1);
798 		if (*p == ']')
799 		    lp->ll_empty2 = TRUE;
800 		else
801 		{
802 		    lp->ll_empty2 = FALSE;
803 		    if (eval1(&p, &var2, TRUE) == FAIL)	// recursive!
804 		    {
805 			clear_tv(&var1);
806 			return NULL;
807 		    }
808 		    if (tv_get_string_chk(&var2) == NULL)
809 		    {
810 			// not a number or string
811 			clear_tv(&var1);
812 			clear_tv(&var2);
813 			return NULL;
814 		    }
815 		}
816 		lp->ll_range = TRUE;
817 	    }
818 	    else
819 		lp->ll_range = FALSE;
820 
821 	    if (*p != ']')
822 	    {
823 		if (!quiet)
824 		    emsg(_(e_missbrac));
825 		clear_tv(&var1);
826 		clear_tv(&var2);
827 		return NULL;
828 	    }
829 
830 	    // Skip to past ']'.
831 	    ++p;
832 	}
833 
834 	if (lp->ll_tv->v_type == VAR_DICT)
835 	{
836 	    if (len == -1)
837 	    {
838 		// "[key]": get key from "var1"
839 		key = tv_get_string_chk(&var1);	// is number or string
840 		if (key == NULL)
841 		{
842 		    clear_tv(&var1);
843 		    return NULL;
844 		}
845 	    }
846 	    lp->ll_list = NULL;
847 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
848 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
849 
850 	    // When assigning to a scope dictionary check that a function and
851 	    // variable name is valid (only variable name unless it is l: or
852 	    // g: dictionary). Disallow overwriting a builtin function.
853 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
854 	    {
855 		int prevval;
856 		int wrong;
857 
858 		if (len != -1)
859 		{
860 		    prevval = key[len];
861 		    key[len] = NUL;
862 		}
863 		else
864 		    prevval = 0; // avoid compiler warning
865 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
866 			       && rettv->v_type == VAR_FUNC
867 			       && var_check_func_name(key, lp->ll_di == NULL))
868 			|| !valid_varname(key);
869 		if (len != -1)
870 		    key[len] = prevval;
871 		if (wrong)
872 		{
873 		    clear_tv(&var1);
874 		    return NULL;
875 		}
876 	    }
877 
878 	    if (lp->ll_di == NULL)
879 	    {
880 		// Can't add "v:" or "a:" variable.
881 		if (lp->ll_dict == get_vimvar_dict()
882 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
883 		{
884 		    semsg(_(e_illvar), name);
885 		    clear_tv(&var1);
886 		    return NULL;
887 		}
888 
889 		// Key does not exist in dict: may need to add it.
890 		if (*p == '[' || *p == '.' || unlet)
891 		{
892 		    if (!quiet)
893 			semsg(_(e_dictkey), key);
894 		    clear_tv(&var1);
895 		    return NULL;
896 		}
897 		if (len == -1)
898 		    lp->ll_newkey = vim_strsave(key);
899 		else
900 		    lp->ll_newkey = vim_strnsave(key, len);
901 		clear_tv(&var1);
902 		if (lp->ll_newkey == NULL)
903 		    p = NULL;
904 		break;
905 	    }
906 	    // existing variable, need to check if it can be changed
907 	    else if ((flags & GLV_READ_ONLY) == 0
908 			     && var_check_ro(lp->ll_di->di_flags, name, FALSE))
909 	    {
910 		clear_tv(&var1);
911 		return NULL;
912 	    }
913 
914 	    clear_tv(&var1);
915 	    lp->ll_tv = &lp->ll_di->di_tv;
916 	}
917 	else if (lp->ll_tv->v_type == VAR_BLOB)
918 	{
919 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
920 
921 	    /*
922 	     * Get the number and item for the only or first index of the List.
923 	     */
924 	    if (empty1)
925 		lp->ll_n1 = 0;
926 	    else
927 		// is number or string
928 		lp->ll_n1 = (long)tv_get_number(&var1);
929 	    clear_tv(&var1);
930 
931 	    if (lp->ll_n1 < 0
932 		    || lp->ll_n1 > bloblen
933 		    || (lp->ll_range && lp->ll_n1 == bloblen))
934 	    {
935 		if (!quiet)
936 		    semsg(_(e_blobidx), lp->ll_n1);
937 		clear_tv(&var2);
938 		return NULL;
939 	    }
940 	    if (lp->ll_range && !lp->ll_empty2)
941 	    {
942 		lp->ll_n2 = (long)tv_get_number(&var2);
943 		clear_tv(&var2);
944 		if (lp->ll_n2 < 0
945 			|| lp->ll_n2 >= bloblen
946 			|| lp->ll_n2 < lp->ll_n1)
947 		{
948 		    if (!quiet)
949 			semsg(_(e_blobidx), lp->ll_n2);
950 		    return NULL;
951 		}
952 	    }
953 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
954 	    lp->ll_tv = NULL;
955 	    break;
956 	}
957 	else
958 	{
959 	    /*
960 	     * Get the number and item for the only or first index of the List.
961 	     */
962 	    if (empty1)
963 		lp->ll_n1 = 0;
964 	    else
965 		// is number or string
966 		lp->ll_n1 = (long)tv_get_number(&var1);
967 	    clear_tv(&var1);
968 
969 	    lp->ll_dict = NULL;
970 	    lp->ll_list = lp->ll_tv->vval.v_list;
971 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
972 	    if (lp->ll_li == NULL)
973 	    {
974 		if (lp->ll_n1 < 0)
975 		{
976 		    lp->ll_n1 = 0;
977 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
978 		}
979 	    }
980 	    if (lp->ll_li == NULL)
981 	    {
982 		clear_tv(&var2);
983 		if (!quiet)
984 		    semsg(_(e_listidx), lp->ll_n1);
985 		return NULL;
986 	    }
987 
988 	    /*
989 	     * May need to find the item or absolute index for the second
990 	     * index of a range.
991 	     * When no index given: "lp->ll_empty2" is TRUE.
992 	     * Otherwise "lp->ll_n2" is set to the second index.
993 	     */
994 	    if (lp->ll_range && !lp->ll_empty2)
995 	    {
996 		lp->ll_n2 = (long)tv_get_number(&var2);
997 						    // is number or string
998 		clear_tv(&var2);
999 		if (lp->ll_n2 < 0)
1000 		{
1001 		    ni = list_find(lp->ll_list, lp->ll_n2);
1002 		    if (ni == NULL)
1003 		    {
1004 			if (!quiet)
1005 			    semsg(_(e_listidx), lp->ll_n2);
1006 			return NULL;
1007 		    }
1008 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
1009 		}
1010 
1011 		// Check that lp->ll_n2 isn't before lp->ll_n1.
1012 		if (lp->ll_n1 < 0)
1013 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
1014 		if (lp->ll_n2 < lp->ll_n1)
1015 		{
1016 		    if (!quiet)
1017 			semsg(_(e_listidx), lp->ll_n2);
1018 		    return NULL;
1019 		}
1020 	    }
1021 
1022 	    lp->ll_tv = &lp->ll_li->li_tv;
1023 	}
1024     }
1025 
1026     clear_tv(&var1);
1027     lp->ll_name_end = p;
1028     return p;
1029 }
1030 
1031 /*
1032  * Clear lval "lp" that was filled by get_lval().
1033  */
1034     void
1035 clear_lval(lval_T *lp)
1036 {
1037     vim_free(lp->ll_exp_name);
1038     vim_free(lp->ll_newkey);
1039 }
1040 
1041 /*
1042  * Set a variable that was parsed by get_lval() to "rettv".
1043  * "endp" points to just after the parsed name.
1044  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
1045  * "%" for "%=", "." for ".=" or "=" for "=".
1046  */
1047     void
1048 set_var_lval(
1049     lval_T	*lp,
1050     char_u	*endp,
1051     typval_T	*rettv,
1052     int		copy,
1053     int		flags,    // LET_IS_CONST and/or LET_NO_COMMAND
1054     char_u	*op)
1055 {
1056     int		cc;
1057     listitem_T	*ri;
1058     dictitem_T	*di;
1059 
1060     if (lp->ll_tv == NULL)
1061     {
1062 	cc = *endp;
1063 	*endp = NUL;
1064 	if (lp->ll_blob != NULL)
1065 	{
1066 	    int	    error = FALSE, val;
1067 
1068 	    if (op != NULL && *op != '=')
1069 	    {
1070 		semsg(_(e_letwrong), op);
1071 		return;
1072 	    }
1073 
1074 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
1075 	    {
1076 		int	il, ir;
1077 
1078 		if (lp->ll_empty2)
1079 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
1080 
1081 		if (lp->ll_n2 - lp->ll_n1 + 1 != blob_len(rettv->vval.v_blob))
1082 		{
1083 		    emsg(_("E972: Blob value does not have the right number of bytes"));
1084 		    return;
1085 		}
1086 		if (lp->ll_empty2)
1087 		    lp->ll_n2 = blob_len(lp->ll_blob);
1088 
1089 		ir = 0;
1090 		for (il = lp->ll_n1; il <= lp->ll_n2; il++)
1091 		    blob_set(lp->ll_blob, il,
1092 			    blob_get(rettv->vval.v_blob, ir++));
1093 	    }
1094 	    else
1095 	    {
1096 		val = (int)tv_get_number_chk(rettv, &error);
1097 		if (!error)
1098 		{
1099 		    garray_T *gap = &lp->ll_blob->bv_ga;
1100 
1101 		    // Allow for appending a byte.  Setting a byte beyond
1102 		    // the end is an error otherwise.
1103 		    if (lp->ll_n1 < gap->ga_len
1104 			    || (lp->ll_n1 == gap->ga_len
1105 				&& ga_grow(&lp->ll_blob->bv_ga, 1) == OK))
1106 		    {
1107 			blob_set(lp->ll_blob, lp->ll_n1, val);
1108 			if (lp->ll_n1 == gap->ga_len)
1109 			    ++gap->ga_len;
1110 		    }
1111 		    // error for invalid range was already given in get_lval()
1112 		}
1113 	    }
1114 	}
1115 	else if (op != NULL && *op != '=')
1116 	{
1117 	    typval_T tv;
1118 
1119 	    if (flags & LET_IS_CONST)
1120 	    {
1121 		emsg(_(e_cannot_mod));
1122 		*endp = cc;
1123 		return;
1124 	    }
1125 
1126 	    // handle +=, -=, *=, /=, %= and .=
1127 	    di = NULL;
1128 	    if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
1129 					     &tv, &di, TRUE, FALSE) == OK)
1130 	    {
1131 		if ((di == NULL
1132 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
1133 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
1134 			&& tv_op(&tv, rettv, op) == OK)
1135 		    set_var(lp->ll_name, &tv, FALSE);
1136 		clear_tv(&tv);
1137 	    }
1138 	}
1139 	else
1140 	    set_var_const(lp->ll_name, lp->ll_type, rettv, copy, flags);
1141 	*endp = cc;
1142     }
1143     else if (var_check_lock(lp->ll_newkey == NULL
1144 		? lp->ll_tv->v_lock
1145 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
1146 	;
1147     else if (lp->ll_range)
1148     {
1149 	listitem_T *ll_li = lp->ll_li;
1150 	int	    ll_n1 = lp->ll_n1;
1151 
1152 	if (flags & LET_IS_CONST)
1153 	{
1154 	    emsg(_("E996: Cannot lock a range"));
1155 	    return;
1156 	}
1157 
1158 	/*
1159 	 * Check whether any of the list items is locked
1160 	 */
1161 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
1162 	{
1163 	    if (var_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
1164 		return;
1165 	    ri = ri->li_next;
1166 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
1167 		break;
1168 	    ll_li = ll_li->li_next;
1169 	    ++ll_n1;
1170 	}
1171 
1172 	/*
1173 	 * Assign the List values to the list items.
1174 	 */
1175 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
1176 	{
1177 	    if (op != NULL && *op != '=')
1178 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
1179 	    else
1180 	    {
1181 		clear_tv(&lp->ll_li->li_tv);
1182 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
1183 	    }
1184 	    ri = ri->li_next;
1185 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
1186 		break;
1187 	    if (lp->ll_li->li_next == NULL)
1188 	    {
1189 		// Need to add an empty item.
1190 		if (list_append_number(lp->ll_list, 0) == FAIL)
1191 		{
1192 		    ri = NULL;
1193 		    break;
1194 		}
1195 	    }
1196 	    lp->ll_li = lp->ll_li->li_next;
1197 	    ++lp->ll_n1;
1198 	}
1199 	if (ri != NULL)
1200 	    emsg(_("E710: List value has more items than target"));
1201 	else if (lp->ll_empty2
1202 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
1203 		: lp->ll_n1 != lp->ll_n2)
1204 	    emsg(_("E711: List value has not enough items"));
1205     }
1206     else
1207     {
1208 	/*
1209 	 * Assign to a List or Dictionary item.
1210 	 */
1211 	if (flags & LET_IS_CONST)
1212 	{
1213 	    emsg(_("E996: Cannot lock a list or dict"));
1214 	    return;
1215 	}
1216 	if (lp->ll_newkey != NULL)
1217 	{
1218 	    if (op != NULL && *op != '=')
1219 	    {
1220 		semsg(_(e_letwrong), op);
1221 		return;
1222 	    }
1223 
1224 	    // Need to add an item to the Dictionary.
1225 	    di = dictitem_alloc(lp->ll_newkey);
1226 	    if (di == NULL)
1227 		return;
1228 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
1229 	    {
1230 		vim_free(di);
1231 		return;
1232 	    }
1233 	    lp->ll_tv = &di->di_tv;
1234 	}
1235 	else if (op != NULL && *op != '=')
1236 	{
1237 	    tv_op(lp->ll_tv, rettv, op);
1238 	    return;
1239 	}
1240 	else
1241 	    clear_tv(lp->ll_tv);
1242 
1243 	/*
1244 	 * Assign the value to the variable or list item.
1245 	 */
1246 	if (copy)
1247 	    copy_tv(rettv, lp->ll_tv);
1248 	else
1249 	{
1250 	    *lp->ll_tv = *rettv;
1251 	    lp->ll_tv->v_lock = 0;
1252 	    init_tv(rettv);
1253 	}
1254     }
1255 }
1256 
1257 /*
1258  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
1259  * and "tv1 .= tv2"
1260  * Returns OK or FAIL.
1261  */
1262     static int
1263 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
1264 {
1265     varnumber_T	n;
1266     char_u	numbuf[NUMBUFLEN];
1267     char_u	*s;
1268 
1269     // Can't do anything with a Funcref, Dict, v:true on the right.
1270     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
1271 		      && tv2->v_type != VAR_BOOL && tv2->v_type != VAR_SPECIAL)
1272     {
1273 	switch (tv1->v_type)
1274 	{
1275 	    case VAR_UNKNOWN:
1276 	    case VAR_ANY:
1277 	    case VAR_VOID:
1278 	    case VAR_DICT:
1279 	    case VAR_FUNC:
1280 	    case VAR_PARTIAL:
1281 	    case VAR_BOOL:
1282 	    case VAR_SPECIAL:
1283 	    case VAR_JOB:
1284 	    case VAR_CHANNEL:
1285 		break;
1286 
1287 	    case VAR_BLOB:
1288 		if (*op != '+' || tv2->v_type != VAR_BLOB)
1289 		    break;
1290 		// BLOB += BLOB
1291 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
1292 		{
1293 		    blob_T  *b1 = tv1->vval.v_blob;
1294 		    blob_T  *b2 = tv2->vval.v_blob;
1295 		    int	i, len = blob_len(b2);
1296 		    for (i = 0; i < len; i++)
1297 			ga_append(&b1->bv_ga, blob_get(b2, i));
1298 		}
1299 		return OK;
1300 
1301 	    case VAR_LIST:
1302 		if (*op != '+' || tv2->v_type != VAR_LIST)
1303 		    break;
1304 		// List += List
1305 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
1306 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
1307 		return OK;
1308 
1309 	    case VAR_NUMBER:
1310 	    case VAR_STRING:
1311 		if (tv2->v_type == VAR_LIST)
1312 		    break;
1313 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
1314 		{
1315 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
1316 		    n = tv_get_number(tv1);
1317 #ifdef FEAT_FLOAT
1318 		    if (tv2->v_type == VAR_FLOAT)
1319 		    {
1320 			float_T f = n;
1321 
1322 			if (*op == '%')
1323 			    break;
1324 			switch (*op)
1325 			{
1326 			    case '+': f += tv2->vval.v_float; break;
1327 			    case '-': f -= tv2->vval.v_float; break;
1328 			    case '*': f *= tv2->vval.v_float; break;
1329 			    case '/': f /= tv2->vval.v_float; break;
1330 			}
1331 			clear_tv(tv1);
1332 			tv1->v_type = VAR_FLOAT;
1333 			tv1->vval.v_float = f;
1334 		    }
1335 		    else
1336 #endif
1337 		    {
1338 			switch (*op)
1339 			{
1340 			    case '+': n += tv_get_number(tv2); break;
1341 			    case '-': n -= tv_get_number(tv2); break;
1342 			    case '*': n *= tv_get_number(tv2); break;
1343 			    case '/': n = num_divide(n, tv_get_number(tv2)); break;
1344 			    case '%': n = num_modulus(n, tv_get_number(tv2)); break;
1345 			}
1346 			clear_tv(tv1);
1347 			tv1->v_type = VAR_NUMBER;
1348 			tv1->vval.v_number = n;
1349 		    }
1350 		}
1351 		else
1352 		{
1353 		    if (tv2->v_type == VAR_FLOAT)
1354 			break;
1355 
1356 		    // str .= str
1357 		    s = tv_get_string(tv1);
1358 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
1359 		    clear_tv(tv1);
1360 		    tv1->v_type = VAR_STRING;
1361 		    tv1->vval.v_string = s;
1362 		}
1363 		return OK;
1364 
1365 	    case VAR_FLOAT:
1366 #ifdef FEAT_FLOAT
1367 		{
1368 		    float_T f;
1369 
1370 		    if (*op == '%' || *op == '.'
1371 				   || (tv2->v_type != VAR_FLOAT
1372 				    && tv2->v_type != VAR_NUMBER
1373 				    && tv2->v_type != VAR_STRING))
1374 			break;
1375 		    if (tv2->v_type == VAR_FLOAT)
1376 			f = tv2->vval.v_float;
1377 		    else
1378 			f = tv_get_number(tv2);
1379 		    switch (*op)
1380 		    {
1381 			case '+': tv1->vval.v_float += f; break;
1382 			case '-': tv1->vval.v_float -= f; break;
1383 			case '*': tv1->vval.v_float *= f; break;
1384 			case '/': tv1->vval.v_float /= f; break;
1385 		    }
1386 		}
1387 #endif
1388 		return OK;
1389 	}
1390     }
1391 
1392     semsg(_(e_letwrong), op);
1393     return FAIL;
1394 }
1395 
1396 /*
1397  * Evaluate the expression used in a ":for var in expr" command.
1398  * "arg" points to "var".
1399  * Set "*errp" to TRUE for an error, FALSE otherwise;
1400  * Return a pointer that holds the info.  Null when there is an error.
1401  */
1402     void *
1403 eval_for_line(
1404     char_u	*arg,
1405     int		*errp,
1406     char_u	**nextcmdp,
1407     int		skip)
1408 {
1409     forinfo_T	*fi;
1410     char_u	*expr;
1411     typval_T	tv;
1412     list_T	*l;
1413 
1414     *errp = TRUE;	// default: there is an error
1415 
1416     fi = ALLOC_CLEAR_ONE(forinfo_T);
1417     if (fi == NULL)
1418 	return NULL;
1419 
1420     expr = skip_var_list(arg, TRUE, &fi->fi_varcount, &fi->fi_semicolon);
1421     if (expr == NULL)
1422 	return fi;
1423 
1424     expr = skipwhite(expr);
1425     if (expr[0] != 'i' || expr[1] != 'n' || !VIM_ISWHITE(expr[2]))
1426     {
1427 	emsg(_(e_missing_in));
1428 	return fi;
1429     }
1430 
1431     if (skip)
1432 	++emsg_skip;
1433     if (eval0(skipwhite(expr + 2), &tv, nextcmdp, !skip) == OK)
1434     {
1435 	*errp = FALSE;
1436 	if (!skip)
1437 	{
1438 	    if (tv.v_type == VAR_LIST)
1439 	    {
1440 		l = tv.vval.v_list;
1441 		if (l == NULL)
1442 		{
1443 		    // a null list is like an empty list: do nothing
1444 		    clear_tv(&tv);
1445 		}
1446 		else
1447 		{
1448 		    // Need a real list here.
1449 		    range_list_materialize(l);
1450 
1451 		    // No need to increment the refcount, it's already set for
1452 		    // the list being used in "tv".
1453 		    fi->fi_list = l;
1454 		    list_add_watch(l, &fi->fi_lw);
1455 		    fi->fi_lw.lw_item = l->lv_first;
1456 		}
1457 	    }
1458 	    else if (tv.v_type == VAR_BLOB)
1459 	    {
1460 		fi->fi_bi = 0;
1461 		if (tv.vval.v_blob != NULL)
1462 		{
1463 		    typval_T btv;
1464 
1465 		    // Make a copy, so that the iteration still works when the
1466 		    // blob is changed.
1467 		    blob_copy(tv.vval.v_blob, &btv);
1468 		    fi->fi_blob = btv.vval.v_blob;
1469 		}
1470 		clear_tv(&tv);
1471 	    }
1472 	    else
1473 	    {
1474 		emsg(_(e_listreq));
1475 		clear_tv(&tv);
1476 	    }
1477 	}
1478     }
1479     if (skip)
1480 	--emsg_skip;
1481 
1482     return fi;
1483 }
1484 
1485 /*
1486  * Use the first item in a ":for" list.  Advance to the next.
1487  * Assign the values to the variable (list).  "arg" points to the first one.
1488  * Return TRUE when a valid item was found, FALSE when at end of list or
1489  * something wrong.
1490  */
1491     int
1492 next_for_item(void *fi_void, char_u *arg)
1493 {
1494     forinfo_T	*fi = (forinfo_T *)fi_void;
1495     int		result;
1496     int		flag = current_sctx.sc_version == SCRIPT_VERSION_VIM9 ?
1497 							LET_NO_COMMAND : 0;
1498     listitem_T	*item;
1499 
1500     if (fi->fi_blob != NULL)
1501     {
1502 	typval_T	tv;
1503 
1504 	if (fi->fi_bi >= blob_len(fi->fi_blob))
1505 	    return FALSE;
1506 	tv.v_type = VAR_NUMBER;
1507 	tv.v_lock = VAR_FIXED;
1508 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
1509 	++fi->fi_bi;
1510 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1511 				       fi->fi_varcount, flag, NULL) == OK;
1512     }
1513 
1514     item = fi->fi_lw.lw_item;
1515     if (item == NULL)
1516 	result = FALSE;
1517     else
1518     {
1519 	fi->fi_lw.lw_item = item->li_next;
1520 	result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
1521 				      fi->fi_varcount, flag, NULL) == OK);
1522     }
1523     return result;
1524 }
1525 
1526 /*
1527  * Free the structure used to store info used by ":for".
1528  */
1529     void
1530 free_for_info(void *fi_void)
1531 {
1532     forinfo_T    *fi = (forinfo_T *)fi_void;
1533 
1534     if (fi != NULL && fi->fi_list != NULL)
1535     {
1536 	list_rem_watch(fi->fi_list, &fi->fi_lw);
1537 	list_unref(fi->fi_list);
1538     }
1539     if (fi != NULL && fi->fi_blob != NULL)
1540 	blob_unref(fi->fi_blob);
1541     vim_free(fi);
1542 }
1543 
1544     void
1545 set_context_for_expression(
1546     expand_T	*xp,
1547     char_u	*arg,
1548     cmdidx_T	cmdidx)
1549 {
1550     int		got_eq = FALSE;
1551     int		c;
1552     char_u	*p;
1553 
1554     if (cmdidx == CMD_let || cmdidx == CMD_const)
1555     {
1556 	xp->xp_context = EXPAND_USER_VARS;
1557 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
1558 	{
1559 	    // ":let var1 var2 ...": find last space.
1560 	    for (p = arg + STRLEN(arg); p >= arg; )
1561 	    {
1562 		xp->xp_pattern = p;
1563 		MB_PTR_BACK(arg, p);
1564 		if (VIM_ISWHITE(*p))
1565 		    break;
1566 	    }
1567 	    return;
1568 	}
1569     }
1570     else
1571 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
1572 							  : EXPAND_EXPRESSION;
1573     while ((xp->xp_pattern = vim_strpbrk(arg,
1574 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
1575     {
1576 	c = *xp->xp_pattern;
1577 	if (c == '&')
1578 	{
1579 	    c = xp->xp_pattern[1];
1580 	    if (c == '&')
1581 	    {
1582 		++xp->xp_pattern;
1583 		xp->xp_context = cmdidx != CMD_let || got_eq
1584 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
1585 	    }
1586 	    else if (c != ' ')
1587 	    {
1588 		xp->xp_context = EXPAND_SETTINGS;
1589 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
1590 		    xp->xp_pattern += 2;
1591 
1592 	    }
1593 	}
1594 	else if (c == '$')
1595 	{
1596 	    // environment variable
1597 	    xp->xp_context = EXPAND_ENV_VARS;
1598 	}
1599 	else if (c == '=')
1600 	{
1601 	    got_eq = TRUE;
1602 	    xp->xp_context = EXPAND_EXPRESSION;
1603 	}
1604 	else if (c == '#'
1605 		&& xp->xp_context == EXPAND_EXPRESSION)
1606 	{
1607 	    // Autoload function/variable contains '#'.
1608 	    break;
1609 	}
1610 	else if ((c == '<' || c == '#')
1611 		&& xp->xp_context == EXPAND_FUNCTIONS
1612 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
1613 	{
1614 	    // Function name can start with "<SNR>" and contain '#'.
1615 	    break;
1616 	}
1617 	else if (cmdidx != CMD_let || got_eq)
1618 	{
1619 	    if (c == '"')	    // string
1620 	    {
1621 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
1622 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
1623 			++xp->xp_pattern;
1624 		xp->xp_context = EXPAND_NOTHING;
1625 	    }
1626 	    else if (c == '\'')	    // literal string
1627 	    {
1628 		// Trick: '' is like stopping and starting a literal string.
1629 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
1630 		    /* skip */ ;
1631 		xp->xp_context = EXPAND_NOTHING;
1632 	    }
1633 	    else if (c == '|')
1634 	    {
1635 		if (xp->xp_pattern[1] == '|')
1636 		{
1637 		    ++xp->xp_pattern;
1638 		    xp->xp_context = EXPAND_EXPRESSION;
1639 		}
1640 		else
1641 		    xp->xp_context = EXPAND_COMMANDS;
1642 	    }
1643 	    else
1644 		xp->xp_context = EXPAND_EXPRESSION;
1645 	}
1646 	else
1647 	    // Doesn't look like something valid, expand as an expression
1648 	    // anyway.
1649 	    xp->xp_context = EXPAND_EXPRESSION;
1650 	arg = xp->xp_pattern;
1651 	if (*arg != NUL)
1652 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
1653 		/* skip */ ;
1654     }
1655     xp->xp_pattern = arg;
1656 }
1657 
1658 /*
1659  * Return TRUE if "pat" matches "text".
1660  * Does not use 'cpo' and always uses 'magic'.
1661  */
1662     int
1663 pattern_match(char_u *pat, char_u *text, int ic)
1664 {
1665     int		matches = FALSE;
1666     char_u	*save_cpo;
1667     regmatch_T	regmatch;
1668 
1669     // avoid 'l' flag in 'cpoptions'
1670     save_cpo = p_cpo;
1671     p_cpo = (char_u *)"";
1672     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1673     if (regmatch.regprog != NULL)
1674     {
1675 	regmatch.rm_ic = ic;
1676 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
1677 	vim_regfree(regmatch.regprog);
1678     }
1679     p_cpo = save_cpo;
1680     return matches;
1681 }
1682 
1683 /*
1684  * Handle a name followed by "(".  Both for just "name(arg)" and for
1685  * "expr->name(arg)".
1686  * Returns OK or FAIL.
1687  */
1688     static int
1689 eval_func(
1690 	char_u	    **arg,	// points to "(", will be advanced
1691 	char_u	    *name,
1692 	int	    name_len,
1693 	typval_T    *rettv,
1694 	int	    evaluate,
1695 	typval_T    *basetv)	// "expr" for "expr->name(arg)"
1696 {
1697     char_u	*s = name;
1698     int		len = name_len;
1699     partial_T	*partial;
1700     int		ret = OK;
1701 
1702     if (!evaluate)
1703 	check_vars(s, len);
1704 
1705     // If "s" is the name of a variable of type VAR_FUNC
1706     // use its contents.
1707     s = deref_func_name(s, &len, &partial, !evaluate);
1708 
1709     // Need to make a copy, in case evaluating the arguments makes
1710     // the name invalid.
1711     s = vim_strsave(s);
1712     if (s == NULL)
1713 	ret = FAIL;
1714     else
1715     {
1716 	funcexe_T funcexe;
1717 
1718 	// Invoke the function.
1719 	CLEAR_FIELD(funcexe);
1720 	funcexe.firstline = curwin->w_cursor.lnum;
1721 	funcexe.lastline = curwin->w_cursor.lnum;
1722 	funcexe.evaluate = evaluate;
1723 	funcexe.partial = partial;
1724 	funcexe.basetv = basetv;
1725 	ret = get_func_tv(s, len, rettv, arg, &funcexe);
1726     }
1727     vim_free(s);
1728 
1729     // If evaluate is FALSE rettv->v_type was not set in
1730     // get_func_tv, but it's needed in handle_subscript() to parse
1731     // what follows. So set it here.
1732     if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
1733     {
1734 	rettv->vval.v_string = NULL;
1735 	rettv->v_type = VAR_FUNC;
1736     }
1737 
1738     // Stop the expression evaluation when immediately
1739     // aborting on error, or when an interrupt occurred or
1740     // an exception was thrown but not caught.
1741     if (evaluate && aborting())
1742     {
1743 	if (ret == OK)
1744 	    clear_tv(rettv);
1745 	ret = FAIL;
1746     }
1747     return ret;
1748 }
1749 
1750 /*
1751  * The "evaluate" argument: When FALSE, the argument is only parsed but not
1752  * executed.  The function may return OK, but the rettv will be of type
1753  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
1754  */
1755 
1756 /*
1757  * Handle zero level expression.
1758  * This calls eval1() and handles error message and nextcmd.
1759  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
1760  * Note: "rettv.v_lock" is not set.
1761  * Return OK or FAIL.
1762  */
1763     int
1764 eval0(
1765     char_u	*arg,
1766     typval_T	*rettv,
1767     char_u	**nextcmd,
1768     int		evaluate)
1769 {
1770     int		ret;
1771     char_u	*p;
1772     int		did_emsg_before = did_emsg;
1773     int		called_emsg_before = called_emsg;
1774 
1775     p = skipwhite(arg);
1776     ret = eval1(&p, rettv, evaluate);
1777     if (ret == FAIL || !ends_excmd2(arg, p))
1778     {
1779 	if (ret != FAIL)
1780 	    clear_tv(rettv);
1781 	/*
1782 	 * Report the invalid expression unless the expression evaluation has
1783 	 * been cancelled due to an aborting error, an interrupt, or an
1784 	 * exception, or we already gave a more specific error.
1785 	 * Also check called_emsg for when using assert_fails().
1786 	 */
1787 	if (!aborting() && did_emsg == did_emsg_before
1788 					  && called_emsg == called_emsg_before)
1789 	    semsg(_(e_invexpr2), arg);
1790 	ret = FAIL;
1791     }
1792     if (nextcmd != NULL)
1793 	*nextcmd = check_nextcmd(p);
1794 
1795     return ret;
1796 }
1797 
1798 /*
1799  * Handle top level expression:
1800  *	expr2 ? expr1 : expr1
1801  *
1802  * "arg" must point to the first non-white of the expression.
1803  * "arg" is advanced to the next non-white after the recognized expression.
1804  *
1805  * Note: "rettv.v_lock" is not set.
1806  *
1807  * Return OK or FAIL.
1808  */
1809     int
1810 eval1(char_u **arg, typval_T *rettv, int evaluate)
1811 {
1812     int		result;
1813     typval_T	var2;
1814 
1815     /*
1816      * Get the first variable.
1817      */
1818     if (eval2(arg, rettv, evaluate) == FAIL)
1819 	return FAIL;
1820 
1821     if ((*arg)[0] == '?')
1822     {
1823 	result = FALSE;
1824 	if (evaluate)
1825 	{
1826 	    int		error = FALSE;
1827 
1828 	    if (tv_get_number_chk(rettv, &error) != 0)
1829 		result = TRUE;
1830 	    clear_tv(rettv);
1831 	    if (error)
1832 		return FAIL;
1833 	}
1834 
1835 	/*
1836 	 * Get the second variable.
1837 	 */
1838 	*arg = skipwhite(*arg + 1);
1839 	if (eval1(arg, rettv, evaluate && result) == FAIL) // recursive!
1840 	    return FAIL;
1841 
1842 	/*
1843 	 * Check for the ":".
1844 	 */
1845 	if ((*arg)[0] != ':')
1846 	{
1847 	    emsg(_(e_missing_colon));
1848 	    if (evaluate && result)
1849 		clear_tv(rettv);
1850 	    return FAIL;
1851 	}
1852 
1853 	/*
1854 	 * Get the third variable.
1855 	 */
1856 	*arg = skipwhite(*arg + 1);
1857 	if (eval1(arg, &var2, evaluate && !result) == FAIL) // recursive!
1858 	{
1859 	    if (evaluate && result)
1860 		clear_tv(rettv);
1861 	    return FAIL;
1862 	}
1863 	if (evaluate && !result)
1864 	    *rettv = var2;
1865     }
1866 
1867     return OK;
1868 }
1869 
1870 /*
1871  * Handle first level expression:
1872  *	expr2 || expr2 || expr2	    logical OR
1873  *
1874  * "arg" must point to the first non-white of the expression.
1875  * "arg" is advanced to the next non-white after the recognized expression.
1876  *
1877  * Return OK or FAIL.
1878  */
1879     static int
1880 eval2(char_u **arg, typval_T *rettv, int evaluate)
1881 {
1882     typval_T	var2;
1883     long	result;
1884     int		first;
1885     int		error = FALSE;
1886 
1887     /*
1888      * Get the first variable.
1889      */
1890     if (eval3(arg, rettv, evaluate) == FAIL)
1891 	return FAIL;
1892 
1893     /*
1894      * Repeat until there is no following "||".
1895      */
1896     first = TRUE;
1897     result = FALSE;
1898     while ((*arg)[0] == '|' && (*arg)[1] == '|')
1899     {
1900 	if (evaluate && first)
1901 	{
1902 	    if (tv_get_number_chk(rettv, &error) != 0)
1903 		result = TRUE;
1904 	    clear_tv(rettv);
1905 	    if (error)
1906 		return FAIL;
1907 	    first = FALSE;
1908 	}
1909 
1910 	/*
1911 	 * Get the second variable.
1912 	 */
1913 	*arg = skipwhite(*arg + 2);
1914 	if (eval3(arg, &var2, evaluate && !result) == FAIL)
1915 	    return FAIL;
1916 
1917 	/*
1918 	 * Compute the result.
1919 	 */
1920 	if (evaluate && !result)
1921 	{
1922 	    if (tv_get_number_chk(&var2, &error) != 0)
1923 		result = TRUE;
1924 	    clear_tv(&var2);
1925 	    if (error)
1926 		return FAIL;
1927 	}
1928 	if (evaluate)
1929 	{
1930 	    rettv->v_type = VAR_NUMBER;
1931 	    rettv->vval.v_number = result;
1932 	}
1933     }
1934 
1935     return OK;
1936 }
1937 
1938 /*
1939  * Handle second level expression:
1940  *	expr3 && expr3 && expr3	    logical AND
1941  *
1942  * "arg" must point to the first non-white of the expression.
1943  * "arg" is advanced to the next non-white after the recognized expression.
1944  *
1945  * Return OK or FAIL.
1946  */
1947     static int
1948 eval3(char_u **arg, typval_T *rettv, int evaluate)
1949 {
1950     typval_T	var2;
1951     long	result;
1952     int		first;
1953     int		error = FALSE;
1954 
1955     /*
1956      * Get the first variable.
1957      */
1958     if (eval4(arg, rettv, evaluate) == FAIL)
1959 	return FAIL;
1960 
1961     /*
1962      * Repeat until there is no following "&&".
1963      */
1964     first = TRUE;
1965     result = TRUE;
1966     while ((*arg)[0] == '&' && (*arg)[1] == '&')
1967     {
1968 	if (evaluate && first)
1969 	{
1970 	    if (tv_get_number_chk(rettv, &error) == 0)
1971 		result = FALSE;
1972 	    clear_tv(rettv);
1973 	    if (error)
1974 		return FAIL;
1975 	    first = FALSE;
1976 	}
1977 
1978 	/*
1979 	 * Get the second variable.
1980 	 */
1981 	*arg = skipwhite(*arg + 2);
1982 	if (eval4(arg, &var2, evaluate && result) == FAIL)
1983 	    return FAIL;
1984 
1985 	/*
1986 	 * Compute the result.
1987 	 */
1988 	if (evaluate && result)
1989 	{
1990 	    if (tv_get_number_chk(&var2, &error) == 0)
1991 		result = FALSE;
1992 	    clear_tv(&var2);
1993 	    if (error)
1994 		return FAIL;
1995 	}
1996 	if (evaluate)
1997 	{
1998 	    rettv->v_type = VAR_NUMBER;
1999 	    rettv->vval.v_number = result;
2000 	}
2001     }
2002 
2003     return OK;
2004 }
2005 
2006 /*
2007  * Handle third level expression:
2008  *	var1 == var2
2009  *	var1 =~ var2
2010  *	var1 != var2
2011  *	var1 !~ var2
2012  *	var1 > var2
2013  *	var1 >= var2
2014  *	var1 < var2
2015  *	var1 <= var2
2016  *	var1 is var2
2017  *	var1 isnot var2
2018  *
2019  * "arg" must point to the first non-white of the expression.
2020  * "arg" is advanced to the next non-white after the recognized expression.
2021  *
2022  * Return OK or FAIL.
2023  */
2024     static int
2025 eval4(char_u **arg, typval_T *rettv, int evaluate)
2026 {
2027     typval_T	var2;
2028     char_u	*p;
2029     int		i;
2030     exptype_T	type = EXPR_UNKNOWN;
2031     int		len = 2;
2032     int		ic;
2033 
2034     /*
2035      * Get the first variable.
2036      */
2037     if (eval5(arg, rettv, evaluate) == FAIL)
2038 	return FAIL;
2039 
2040     p = *arg;
2041     switch (p[0])
2042     {
2043 	case '=':   if (p[1] == '=')
2044 			type = EXPR_EQUAL;
2045 		    else if (p[1] == '~')
2046 			type = EXPR_MATCH;
2047 		    break;
2048 	case '!':   if (p[1] == '=')
2049 			type = EXPR_NEQUAL;
2050 		    else if (p[1] == '~')
2051 			type = EXPR_NOMATCH;
2052 		    break;
2053 	case '>':   if (p[1] != '=')
2054 		    {
2055 			type = EXPR_GREATER;
2056 			len = 1;
2057 		    }
2058 		    else
2059 			type = EXPR_GEQUAL;
2060 		    break;
2061 	case '<':   if (p[1] != '=')
2062 		    {
2063 			type = EXPR_SMALLER;
2064 			len = 1;
2065 		    }
2066 		    else
2067 			type = EXPR_SEQUAL;
2068 		    break;
2069 	case 'i':   if (p[1] == 's')
2070 		    {
2071 			if (p[2] == 'n' && p[3] == 'o' && p[4] == 't')
2072 			    len = 5;
2073 			i = p[len];
2074 			if (!isalnum(i) && i != '_')
2075 			    type = len == 2 ? EXPR_IS : EXPR_ISNOT;
2076 		    }
2077 		    break;
2078     }
2079 
2080     /*
2081      * If there is a comparative operator, use it.
2082      */
2083     if (type != EXPR_UNKNOWN)
2084     {
2085 	// extra question mark appended: ignore case
2086 	if (p[len] == '?')
2087 	{
2088 	    ic = TRUE;
2089 	    ++len;
2090 	}
2091 	// extra '#' appended: match case
2092 	else if (p[len] == '#')
2093 	{
2094 	    ic = FALSE;
2095 	    ++len;
2096 	}
2097 	// nothing appended: use 'ignorecase'
2098 	else
2099 	    ic = p_ic;
2100 
2101 	/*
2102 	 * Get the second variable.
2103 	 */
2104 	*arg = skipwhite(p + len);
2105 	if (eval5(arg, &var2, evaluate) == FAIL)
2106 	{
2107 	    clear_tv(rettv);
2108 	    return FAIL;
2109 	}
2110 	if (evaluate)
2111 	{
2112 	    int ret = typval_compare(rettv, &var2, type, ic);
2113 
2114 	    clear_tv(&var2);
2115 	    return ret;
2116 	}
2117     }
2118 
2119     return OK;
2120 }
2121 
2122     void
2123 eval_addblob(typval_T *tv1, typval_T *tv2)
2124 {
2125     blob_T  *b1 = tv1->vval.v_blob;
2126     blob_T  *b2 = tv2->vval.v_blob;
2127     blob_T  *b = blob_alloc();
2128     int	    i;
2129 
2130     if (b != NULL)
2131     {
2132 	for (i = 0; i < blob_len(b1); i++)
2133 	    ga_append(&b->bv_ga, blob_get(b1, i));
2134 	for (i = 0; i < blob_len(b2); i++)
2135 	    ga_append(&b->bv_ga, blob_get(b2, i));
2136 
2137 	clear_tv(tv1);
2138 	rettv_blob_set(tv1, b);
2139     }
2140 }
2141 
2142     int
2143 eval_addlist(typval_T *tv1, typval_T *tv2)
2144 {
2145     typval_T var3;
2146 
2147     // concatenate Lists
2148     if (list_concat(tv1->vval.v_list, tv2->vval.v_list, &var3) == FAIL)
2149     {
2150 	clear_tv(tv1);
2151 	clear_tv(tv2);
2152 	return FAIL;
2153     }
2154     clear_tv(tv1);
2155     *tv1 = var3;
2156     return OK;
2157 }
2158 
2159 /*
2160  * Handle fourth level expression:
2161  *	+	number addition
2162  *	-	number subtraction
2163  *	.	string concatenation (if script version is 1)
2164  *	..	string concatenation
2165  *
2166  * "arg" must point to the first non-white of the expression.
2167  * "arg" is advanced to the next non-white after the recognized expression.
2168  *
2169  * Return OK or FAIL.
2170  */
2171     static int
2172 eval5(char_u **arg, typval_T *rettv, int evaluate)
2173 {
2174     typval_T	var2;
2175     int		op;
2176     varnumber_T	n1, n2;
2177 #ifdef FEAT_FLOAT
2178     float_T	f1 = 0, f2 = 0;
2179 #endif
2180     char_u	*s1, *s2;
2181     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
2182     char_u	*p;
2183     int		concat;
2184 
2185     /*
2186      * Get the first variable.
2187      */
2188     if (eval6(arg, rettv, evaluate, FALSE) == FAIL)
2189 	return FAIL;
2190 
2191     /*
2192      * Repeat computing, until no '+', '-' or '.' is following.
2193      */
2194     for (;;)
2195     {
2196 	// "." is only string concatenation when scriptversion is 1
2197 	op = **arg;
2198 	concat = op == '.'
2199 			&& (*(*arg + 1) == '.' || current_sctx.sc_version < 2);
2200 	if (op != '+' && op != '-' && !concat)
2201 	    break;
2202 
2203 	if ((op != '+' || (rettv->v_type != VAR_LIST
2204 						 && rettv->v_type != VAR_BLOB))
2205 #ifdef FEAT_FLOAT
2206 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2207 #endif
2208 		)
2209 	{
2210 	    // For "list + ...", an illegal use of the first operand as
2211 	    // a number cannot be determined before evaluating the 2nd
2212 	    // operand: if this is also a list, all is ok.
2213 	    // For "something . ...", "something - ..." or "non-list + ...",
2214 	    // we know that the first operand needs to be a string or number
2215 	    // without evaluating the 2nd operand.  So check before to avoid
2216 	    // side effects after an error.
2217 	    if (evaluate && tv_get_string_chk(rettv) == NULL)
2218 	    {
2219 		clear_tv(rettv);
2220 		return FAIL;
2221 	    }
2222 	}
2223 
2224 	/*
2225 	 * Get the second variable.
2226 	 */
2227 	if (op == '.' && *(*arg + 1) == '.')  // .. string concatenation
2228 	    ++*arg;
2229 	*arg = skipwhite(*arg + 1);
2230 	if (eval6(arg, &var2, evaluate, op == '.') == FAIL)
2231 	{
2232 	    clear_tv(rettv);
2233 	    return FAIL;
2234 	}
2235 
2236 	if (evaluate)
2237 	{
2238 	    /*
2239 	     * Compute the result.
2240 	     */
2241 	    if (op == '.')
2242 	    {
2243 		s1 = tv_get_string_buf(rettv, buf1);	// already checked
2244 		s2 = tv_get_string_buf_chk(&var2, buf2);
2245 		if (s2 == NULL)		// type error ?
2246 		{
2247 		    clear_tv(rettv);
2248 		    clear_tv(&var2);
2249 		    return FAIL;
2250 		}
2251 		p = concat_str(s1, s2);
2252 		clear_tv(rettv);
2253 		rettv->v_type = VAR_STRING;
2254 		rettv->vval.v_string = p;
2255 	    }
2256 	    else if (op == '+' && rettv->v_type == VAR_BLOB
2257 						   && var2.v_type == VAR_BLOB)
2258 		eval_addblob(rettv, &var2);
2259 	    else if (op == '+' && rettv->v_type == VAR_LIST
2260 						   && var2.v_type == VAR_LIST)
2261 	    {
2262 		if (eval_addlist(rettv, &var2) == FAIL)
2263 		    return FAIL;
2264 	    }
2265 	    else
2266 	    {
2267 		int	    error = FALSE;
2268 
2269 #ifdef FEAT_FLOAT
2270 		if (rettv->v_type == VAR_FLOAT)
2271 		{
2272 		    f1 = rettv->vval.v_float;
2273 		    n1 = 0;
2274 		}
2275 		else
2276 #endif
2277 		{
2278 		    n1 = tv_get_number_chk(rettv, &error);
2279 		    if (error)
2280 		    {
2281 			// This can only happen for "list + non-list".  For
2282 			// "non-list + ..." or "something - ...", we returned
2283 			// before evaluating the 2nd operand.
2284 			clear_tv(rettv);
2285 			return FAIL;
2286 		    }
2287 #ifdef FEAT_FLOAT
2288 		    if (var2.v_type == VAR_FLOAT)
2289 			f1 = n1;
2290 #endif
2291 		}
2292 #ifdef FEAT_FLOAT
2293 		if (var2.v_type == VAR_FLOAT)
2294 		{
2295 		    f2 = var2.vval.v_float;
2296 		    n2 = 0;
2297 		}
2298 		else
2299 #endif
2300 		{
2301 		    n2 = tv_get_number_chk(&var2, &error);
2302 		    if (error)
2303 		    {
2304 			clear_tv(rettv);
2305 			clear_tv(&var2);
2306 			return FAIL;
2307 		    }
2308 #ifdef FEAT_FLOAT
2309 		    if (rettv->v_type == VAR_FLOAT)
2310 			f2 = n2;
2311 #endif
2312 		}
2313 		clear_tv(rettv);
2314 
2315 #ifdef FEAT_FLOAT
2316 		// If there is a float on either side the result is a float.
2317 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
2318 		{
2319 		    if (op == '+')
2320 			f1 = f1 + f2;
2321 		    else
2322 			f1 = f1 - f2;
2323 		    rettv->v_type = VAR_FLOAT;
2324 		    rettv->vval.v_float = f1;
2325 		}
2326 		else
2327 #endif
2328 		{
2329 		    if (op == '+')
2330 			n1 = n1 + n2;
2331 		    else
2332 			n1 = n1 - n2;
2333 		    rettv->v_type = VAR_NUMBER;
2334 		    rettv->vval.v_number = n1;
2335 		}
2336 	    }
2337 	    clear_tv(&var2);
2338 	}
2339     }
2340     return OK;
2341 }
2342 
2343 /*
2344  * Handle fifth level expression:
2345  *	*	number multiplication
2346  *	/	number division
2347  *	%	number modulo
2348  *
2349  * "arg" must point to the first non-white of the expression.
2350  * "arg" is advanced to the next non-white after the recognized expression.
2351  *
2352  * Return OK or FAIL.
2353  */
2354     static int
2355 eval6(
2356     char_u	**arg,
2357     typval_T	*rettv,
2358     int		evaluate,
2359     int		want_string)  // after "." operator
2360 {
2361     typval_T	var2;
2362     int		op;
2363     varnumber_T	n1, n2;
2364 #ifdef FEAT_FLOAT
2365     int		use_float = FALSE;
2366     float_T	f1 = 0, f2 = 0;
2367 #endif
2368     int		error = FALSE;
2369 
2370     /*
2371      * Get the first variable.
2372      */
2373     if (eval7(arg, rettv, evaluate, want_string) == FAIL)
2374 	return FAIL;
2375 
2376     /*
2377      * Repeat computing, until no '*', '/' or '%' is following.
2378      */
2379     for (;;)
2380     {
2381 	op = **arg;
2382 	if (op != '*' && op != '/' && op != '%')
2383 	    break;
2384 
2385 	if (evaluate)
2386 	{
2387 #ifdef FEAT_FLOAT
2388 	    if (rettv->v_type == VAR_FLOAT)
2389 	    {
2390 		f1 = rettv->vval.v_float;
2391 		use_float = TRUE;
2392 		n1 = 0;
2393 	    }
2394 	    else
2395 #endif
2396 		n1 = tv_get_number_chk(rettv, &error);
2397 	    clear_tv(rettv);
2398 	    if (error)
2399 		return FAIL;
2400 	}
2401 	else
2402 	    n1 = 0;
2403 
2404 	/*
2405 	 * Get the second variable.
2406 	 */
2407 	*arg = skipwhite(*arg + 1);
2408 	if (eval7(arg, &var2, evaluate, FALSE) == FAIL)
2409 	    return FAIL;
2410 
2411 	if (evaluate)
2412 	{
2413 #ifdef FEAT_FLOAT
2414 	    if (var2.v_type == VAR_FLOAT)
2415 	    {
2416 		if (!use_float)
2417 		{
2418 		    f1 = n1;
2419 		    use_float = TRUE;
2420 		}
2421 		f2 = var2.vval.v_float;
2422 		n2 = 0;
2423 	    }
2424 	    else
2425 #endif
2426 	    {
2427 		n2 = tv_get_number_chk(&var2, &error);
2428 		clear_tv(&var2);
2429 		if (error)
2430 		    return FAIL;
2431 #ifdef FEAT_FLOAT
2432 		if (use_float)
2433 		    f2 = n2;
2434 #endif
2435 	    }
2436 
2437 	    /*
2438 	     * Compute the result.
2439 	     * When either side is a float the result is a float.
2440 	     */
2441 #ifdef FEAT_FLOAT
2442 	    if (use_float)
2443 	    {
2444 		if (op == '*')
2445 		    f1 = f1 * f2;
2446 		else if (op == '/')
2447 		{
2448 # ifdef VMS
2449 		    // VMS crashes on divide by zero, work around it
2450 		    if (f2 == 0.0)
2451 		    {
2452 			if (f1 == 0)
2453 			    f1 = -1 * __F_FLT_MAX - 1L;   // similar to NaN
2454 			else if (f1 < 0)
2455 			    f1 = -1 * __F_FLT_MAX;
2456 			else
2457 			    f1 = __F_FLT_MAX;
2458 		    }
2459 		    else
2460 			f1 = f1 / f2;
2461 # else
2462 		    // We rely on the floating point library to handle divide
2463 		    // by zero to result in "inf" and not a crash.
2464 		    f1 = f1 / f2;
2465 # endif
2466 		}
2467 		else
2468 		{
2469 		    emsg(_(e_modulus));
2470 		    return FAIL;
2471 		}
2472 		rettv->v_type = VAR_FLOAT;
2473 		rettv->vval.v_float = f1;
2474 	    }
2475 	    else
2476 #endif
2477 	    {
2478 		if (op == '*')
2479 		    n1 = n1 * n2;
2480 		else if (op == '/')
2481 		    n1 = num_divide(n1, n2);
2482 		else
2483 		    n1 = num_modulus(n1, n2);
2484 
2485 		rettv->v_type = VAR_NUMBER;
2486 		rettv->vval.v_number = n1;
2487 	    }
2488 	}
2489     }
2490 
2491     return OK;
2492 }
2493 
2494 /*
2495  * Handle sixth level expression:
2496  *  number		number constant
2497  *  0zFFFFFFFF		Blob constant
2498  *  "string"		string constant
2499  *  'string'		literal string constant
2500  *  &option-name	option value
2501  *  @r			register contents
2502  *  identifier		variable value
2503  *  function()		function call
2504  *  $VAR		environment variable
2505  *  (expression)	nested expression
2506  *  [expr, expr]	List
2507  *  {arg, arg -> expr}	Lambda
2508  *  {key: val, key: val}   Dictionary
2509  *  #{key: val, key: val}  Dictionary with literal keys
2510  *
2511  *  Also handle:
2512  *  ! in front		logical NOT
2513  *  - in front		unary minus
2514  *  + in front		unary plus (ignored)
2515  *  trailing []		subscript in String or List
2516  *  trailing .name	entry in Dictionary
2517  *  trailing ->name()	method call
2518  *
2519  * "arg" must point to the first non-white of the expression.
2520  * "arg" is advanced to the next non-white after the recognized expression.
2521  *
2522  * Return OK or FAIL.
2523  */
2524     static int
2525 eval7(
2526     char_u	**arg,
2527     typval_T	*rettv,
2528     int		evaluate,
2529     int		want_string)	// after "." operator
2530 {
2531     int		len;
2532     char_u	*s;
2533     char_u	*start_leader, *end_leader;
2534     int		ret = OK;
2535     char_u	*alias;
2536 
2537     /*
2538      * Initialise variable so that clear_tv() can't mistake this for a
2539      * string and free a string that isn't there.
2540      */
2541     rettv->v_type = VAR_UNKNOWN;
2542 
2543     /*
2544      * Skip '!', '-' and '+' characters.  They are handled later.
2545      */
2546     start_leader = *arg;
2547     while (**arg == '!' || **arg == '-' || **arg == '+')
2548 	*arg = skipwhite(*arg + 1);
2549     end_leader = *arg;
2550 
2551     if (**arg == '.' && (!isdigit(*(*arg + 1))
2552 #ifdef FEAT_FLOAT
2553 	    || current_sctx.sc_version < 2
2554 #endif
2555 	    ))
2556     {
2557 	semsg(_(e_invexpr2), *arg);
2558 	++*arg;
2559 	return FAIL;
2560     }
2561 
2562     switch (**arg)
2563     {
2564     /*
2565      * Number constant.
2566      */
2567     case '0':
2568     case '1':
2569     case '2':
2570     case '3':
2571     case '4':
2572     case '5':
2573     case '6':
2574     case '7':
2575     case '8':
2576     case '9':
2577     case '.':	ret = get_number_tv(arg, rettv, evaluate, want_string);
2578 		break;
2579 
2580     /*
2581      * String constant: "string".
2582      */
2583     case '"':	ret = get_string_tv(arg, rettv, evaluate);
2584 		break;
2585 
2586     /*
2587      * Literal string constant: 'str''ing'.
2588      */
2589     case '\'':	ret = get_lit_string_tv(arg, rettv, evaluate);
2590 		break;
2591 
2592     /*
2593      * List: [expr, expr]
2594      */
2595     case '[':	ret = get_list_tv(arg, rettv, evaluate, TRUE);
2596 		break;
2597 
2598     /*
2599      * Dictionary: #{key: val, key: val}
2600      */
2601     case '#':	if ((*arg)[1] == '{')
2602 		{
2603 		    ++*arg;
2604 		    ret = eval_dict(arg, rettv, evaluate, TRUE);
2605 		}
2606 		else
2607 		    ret = NOTDONE;
2608 		break;
2609 
2610     /*
2611      * Lambda: {arg, arg -> expr}
2612      * Dictionary: {'key': val, 'key': val}
2613      */
2614     case '{':	ret = get_lambda_tv(arg, rettv, evaluate);
2615 		if (ret == NOTDONE)
2616 		    ret = eval_dict(arg, rettv, evaluate, FALSE);
2617 		break;
2618 
2619     /*
2620      * Option value: &name
2621      */
2622     case '&':	ret = get_option_tv(arg, rettv, evaluate);
2623 		break;
2624 
2625     /*
2626      * Environment variable: $VAR.
2627      */
2628     case '$':	ret = get_env_tv(arg, rettv, evaluate);
2629 		break;
2630 
2631     /*
2632      * Register contents: @r.
2633      */
2634     case '@':	++*arg;
2635 		if (evaluate)
2636 		{
2637 		    rettv->v_type = VAR_STRING;
2638 		    rettv->vval.v_string = get_reg_contents(**arg,
2639 							    GREG_EXPR_SRC);
2640 		}
2641 		if (**arg != NUL)
2642 		    ++*arg;
2643 		break;
2644 
2645     /*
2646      * nested expression: (expression).
2647      */
2648     case '(':	*arg = skipwhite(*arg + 1);
2649 		ret = eval1(arg, rettv, evaluate);	// recursive!
2650 		if (**arg == ')')
2651 		    ++*arg;
2652 		else if (ret == OK)
2653 		{
2654 		    emsg(_(e_missing_close));
2655 		    clear_tv(rettv);
2656 		    ret = FAIL;
2657 		}
2658 		break;
2659 
2660     default:	ret = NOTDONE;
2661 		break;
2662     }
2663 
2664     if (ret == NOTDONE)
2665     {
2666 	/*
2667 	 * Must be a variable or function name.
2668 	 * Can also be a curly-braces kind of name: {expr}.
2669 	 */
2670 	s = *arg;
2671 	len = get_name_len(arg, &alias, evaluate, TRUE);
2672 	if (alias != NULL)
2673 	    s = alias;
2674 
2675 	if (len <= 0)
2676 	    ret = FAIL;
2677 	else
2678 	{
2679 	    if (**arg == '(')		// recursive!
2680 		ret = eval_func(arg, s, len, rettv, evaluate, NULL);
2681 	    else if (evaluate)
2682 		ret = get_var_tv(s, len, rettv, NULL, TRUE, FALSE);
2683 	    else
2684 	    {
2685 		check_vars(s, len);
2686 		ret = OK;
2687 	    }
2688 	}
2689 	vim_free(alias);
2690     }
2691 
2692     *arg = skipwhite(*arg);
2693 
2694     // Handle following '[', '(' and '.' for expr[expr], expr.name,
2695     // expr(expr), expr->name(expr)
2696     if (ret == OK)
2697 	ret = handle_subscript(arg, rettv, evaluate, TRUE,
2698 						    start_leader, &end_leader);
2699 
2700     /*
2701      * Apply logical NOT and unary '-', from right to left, ignore '+'.
2702      */
2703     if (ret == OK && evaluate && end_leader > start_leader)
2704 	ret = eval7_leader(rettv, start_leader, &end_leader);
2705     return ret;
2706 }
2707 
2708 /*
2709  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
2710  * Adjusts "end_leaderp" until it is at "start_leader".
2711  */
2712     static int
2713 eval7_leader(typval_T *rettv, char_u *start_leader, char_u **end_leaderp)
2714 {
2715     char_u	*end_leader = *end_leaderp;
2716     int		ret = OK;
2717     int		error = FALSE;
2718     varnumber_T val = 0;
2719 #ifdef FEAT_FLOAT
2720     float_T	    f = 0.0;
2721 
2722     if (rettv->v_type == VAR_FLOAT)
2723 	f = rettv->vval.v_float;
2724     else
2725 #endif
2726 	val = tv_get_number_chk(rettv, &error);
2727     if (error)
2728     {
2729 	clear_tv(rettv);
2730 	ret = FAIL;
2731     }
2732     else
2733     {
2734 	while (end_leader > start_leader)
2735 	{
2736 	    --end_leader;
2737 	    if (*end_leader == '!')
2738 	    {
2739 #ifdef FEAT_FLOAT
2740 		if (rettv->v_type == VAR_FLOAT)
2741 		    f = !f;
2742 		else
2743 #endif
2744 		    val = !val;
2745 	    }
2746 	    else if (*end_leader == '-')
2747 	    {
2748 #ifdef FEAT_FLOAT
2749 		if (rettv->v_type == VAR_FLOAT)
2750 		    f = -f;
2751 		else
2752 #endif
2753 		    val = -val;
2754 	    }
2755 	}
2756 #ifdef FEAT_FLOAT
2757 	if (rettv->v_type == VAR_FLOAT)
2758 	{
2759 	    clear_tv(rettv);
2760 	    rettv->vval.v_float = f;
2761 	}
2762 	else
2763 #endif
2764 	{
2765 	    clear_tv(rettv);
2766 	    rettv->v_type = VAR_NUMBER;
2767 	    rettv->vval.v_number = val;
2768 	}
2769     }
2770     *end_leaderp = end_leader;
2771     return ret;
2772 }
2773 
2774 /*
2775  * Call the function referred to in "rettv".
2776  */
2777     static int
2778 call_func_rettv(
2779 	char_u	    **arg,
2780 	typval_T    *rettv,
2781 	int	    evaluate,
2782 	dict_T	    *selfdict,
2783 	typval_T    *basetv)
2784 {
2785     partial_T	*pt = NULL;
2786     funcexe_T	funcexe;
2787     typval_T	functv;
2788     char_u	*s;
2789     int		ret;
2790 
2791     // need to copy the funcref so that we can clear rettv
2792     if (evaluate)
2793     {
2794 	functv = *rettv;
2795 	rettv->v_type = VAR_UNKNOWN;
2796 
2797 	// Invoke the function.  Recursive!
2798 	if (functv.v_type == VAR_PARTIAL)
2799 	{
2800 	    pt = functv.vval.v_partial;
2801 	    s = partial_name(pt);
2802 	}
2803 	else
2804 	    s = functv.vval.v_string;
2805     }
2806     else
2807 	s = (char_u *)"";
2808 
2809     CLEAR_FIELD(funcexe);
2810     funcexe.firstline = curwin->w_cursor.lnum;
2811     funcexe.lastline = curwin->w_cursor.lnum;
2812     funcexe.evaluate = evaluate;
2813     funcexe.partial = pt;
2814     funcexe.selfdict = selfdict;
2815     funcexe.basetv = basetv;
2816     ret = get_func_tv(s, -1, rettv, arg, &funcexe);
2817 
2818     // Clear the funcref afterwards, so that deleting it while
2819     // evaluating the arguments is possible (see test55).
2820     if (evaluate)
2821 	clear_tv(&functv);
2822 
2823     return ret;
2824 }
2825 
2826 /*
2827  * Evaluate "->method()".
2828  * "*arg" points to the '-'.
2829  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
2830  */
2831     static int
2832 eval_lambda(
2833     char_u	**arg,
2834     typval_T	*rettv,
2835     int		evaluate,
2836     int		verbose)	// give error messages
2837 {
2838     typval_T	base = *rettv;
2839     int		ret;
2840 
2841     // Skip over the ->.
2842     *arg += 2;
2843     rettv->v_type = VAR_UNKNOWN;
2844 
2845     ret = get_lambda_tv(arg, rettv, evaluate);
2846     if (ret != OK)
2847 	return FAIL;
2848     else if (**arg != '(')
2849     {
2850 	if (verbose)
2851 	{
2852 	    if (*skipwhite(*arg) == '(')
2853 		emsg(_(e_nowhitespace));
2854 	    else
2855 		semsg(_(e_missing_paren), "lambda");
2856 	}
2857 	clear_tv(rettv);
2858 	ret = FAIL;
2859     }
2860     else
2861 	ret = call_func_rettv(arg, rettv, evaluate, NULL, &base);
2862 
2863     // Clear the funcref afterwards, so that deleting it while
2864     // evaluating the arguments is possible (see test55).
2865     if (evaluate)
2866 	clear_tv(&base);
2867 
2868     return ret;
2869 }
2870 
2871 /*
2872  * Evaluate "->method()".
2873  * "*arg" points to the '-'.
2874  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
2875  */
2876     static int
2877 eval_method(
2878     char_u	**arg,
2879     typval_T	*rettv,
2880     int		evaluate,
2881     int		verbose)	// give error messages
2882 {
2883     char_u	*name;
2884     long	len;
2885     char_u	*alias;
2886     typval_T	base = *rettv;
2887     int		ret;
2888 
2889     // Skip over the ->.
2890     *arg += 2;
2891     rettv->v_type = VAR_UNKNOWN;
2892 
2893     name = *arg;
2894     len = get_name_len(arg, &alias, evaluate, TRUE);
2895     if (alias != NULL)
2896 	name = alias;
2897 
2898     if (len <= 0)
2899     {
2900 	if (verbose)
2901 	    emsg(_("E260: Missing name after ->"));
2902 	ret = FAIL;
2903     }
2904     else
2905     {
2906 	if (**arg != '(')
2907 	{
2908 	    if (verbose)
2909 		semsg(_(e_missing_paren), name);
2910 	    ret = FAIL;
2911 	}
2912 	else if (VIM_ISWHITE((*arg)[-1]))
2913 	{
2914 	    if (verbose)
2915 		emsg(_(e_nowhitespace));
2916 	    ret = FAIL;
2917 	}
2918 	else
2919 	    ret = eval_func(arg, name, len, rettv, evaluate, &base);
2920     }
2921 
2922     // Clear the funcref afterwards, so that deleting it while
2923     // evaluating the arguments is possible (see test55).
2924     if (evaluate)
2925 	clear_tv(&base);
2926 
2927     return ret;
2928 }
2929 
2930 /*
2931  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
2932  * "*arg" points to the '[' or '.'.
2933  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
2934  */
2935     static int
2936 eval_index(
2937     char_u	**arg,
2938     typval_T	*rettv,
2939     int		evaluate,
2940     int		verbose)	// give error messages
2941 {
2942     int		empty1 = FALSE, empty2 = FALSE;
2943     typval_T	var1, var2;
2944     long	i;
2945     long	n1, n2 = 0;
2946     long	len = -1;
2947     int		range = FALSE;
2948     char_u	*s;
2949     char_u	*key = NULL;
2950 
2951     switch (rettv->v_type)
2952     {
2953 	case VAR_FUNC:
2954 	case VAR_PARTIAL:
2955 	    if (verbose)
2956 		emsg(_("E695: Cannot index a Funcref"));
2957 	    return FAIL;
2958 	case VAR_FLOAT:
2959 #ifdef FEAT_FLOAT
2960 	    if (verbose)
2961 		emsg(_(e_float_as_string));
2962 	    return FAIL;
2963 #endif
2964 	case VAR_BOOL:
2965 	case VAR_SPECIAL:
2966 	case VAR_JOB:
2967 	case VAR_CHANNEL:
2968 	    if (verbose)
2969 		emsg(_("E909: Cannot index a special variable"));
2970 	    return FAIL;
2971 	case VAR_UNKNOWN:
2972 	case VAR_ANY:
2973 	case VAR_VOID:
2974 	    if (evaluate)
2975 		return FAIL;
2976 	    // FALLTHROUGH
2977 
2978 	case VAR_STRING:
2979 	case VAR_NUMBER:
2980 	case VAR_LIST:
2981 	case VAR_DICT:
2982 	case VAR_BLOB:
2983 	    break;
2984     }
2985 
2986     init_tv(&var1);
2987     init_tv(&var2);
2988     if (**arg == '.')
2989     {
2990 	/*
2991 	 * dict.name
2992 	 */
2993 	key = *arg + 1;
2994 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
2995 	    ;
2996 	if (len == 0)
2997 	    return FAIL;
2998 	*arg = skipwhite(key + len);
2999     }
3000     else
3001     {
3002 	/*
3003 	 * something[idx]
3004 	 *
3005 	 * Get the (first) variable from inside the [].
3006 	 */
3007 	*arg = skipwhite(*arg + 1);
3008 	if (**arg == ':')
3009 	    empty1 = TRUE;
3010 	else if (eval1(arg, &var1, evaluate) == FAIL)	// recursive!
3011 	    return FAIL;
3012 	else if (evaluate && tv_get_string_chk(&var1) == NULL)
3013 	{
3014 	    // not a number or string
3015 	    clear_tv(&var1);
3016 	    return FAIL;
3017 	}
3018 
3019 	/*
3020 	 * Get the second variable from inside the [:].
3021 	 */
3022 	if (**arg == ':')
3023 	{
3024 	    range = TRUE;
3025 	    *arg = skipwhite(*arg + 1);
3026 	    if (**arg == ']')
3027 		empty2 = TRUE;
3028 	    else if (eval1(arg, &var2, evaluate) == FAIL)	// recursive!
3029 	    {
3030 		if (!empty1)
3031 		    clear_tv(&var1);
3032 		return FAIL;
3033 	    }
3034 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
3035 	    {
3036 		// not a number or string
3037 		if (!empty1)
3038 		    clear_tv(&var1);
3039 		clear_tv(&var2);
3040 		return FAIL;
3041 	    }
3042 	}
3043 
3044 	// Check for the ']'.
3045 	if (**arg != ']')
3046 	{
3047 	    if (verbose)
3048 		emsg(_(e_missbrac));
3049 	    clear_tv(&var1);
3050 	    if (range)
3051 		clear_tv(&var2);
3052 	    return FAIL;
3053 	}
3054 	*arg = skipwhite(*arg + 1);	// skip the ']'
3055     }
3056 
3057     if (evaluate)
3058     {
3059 	n1 = 0;
3060 	if (!empty1 && rettv->v_type != VAR_DICT)
3061 	{
3062 	    n1 = tv_get_number(&var1);
3063 	    clear_tv(&var1);
3064 	}
3065 	if (range)
3066 	{
3067 	    if (empty2)
3068 		n2 = -1;
3069 	    else
3070 	    {
3071 		n2 = tv_get_number(&var2);
3072 		clear_tv(&var2);
3073 	    }
3074 	}
3075 
3076 	switch (rettv->v_type)
3077 	{
3078 	    case VAR_UNKNOWN:
3079 	    case VAR_ANY:
3080 	    case VAR_VOID:
3081 	    case VAR_FUNC:
3082 	    case VAR_PARTIAL:
3083 	    case VAR_FLOAT:
3084 	    case VAR_BOOL:
3085 	    case VAR_SPECIAL:
3086 	    case VAR_JOB:
3087 	    case VAR_CHANNEL:
3088 		break; // not evaluating, skipping over subscript
3089 
3090 	    case VAR_NUMBER:
3091 	    case VAR_STRING:
3092 		s = tv_get_string(rettv);
3093 		len = (long)STRLEN(s);
3094 		if (range)
3095 		{
3096 		    // The resulting variable is a substring.  If the indexes
3097 		    // are out of range the result is empty.
3098 		    if (n1 < 0)
3099 		    {
3100 			n1 = len + n1;
3101 			if (n1 < 0)
3102 			    n1 = 0;
3103 		    }
3104 		    if (n2 < 0)
3105 			n2 = len + n2;
3106 		    else if (n2 >= len)
3107 			n2 = len;
3108 		    if (n1 >= len || n2 < 0 || n1 > n2)
3109 			s = NULL;
3110 		    else
3111 			s = vim_strnsave(s + n1, (int)(n2 - n1 + 1));
3112 		}
3113 		else
3114 		{
3115 		    // The resulting variable is a string of a single
3116 		    // character.  If the index is too big or negative the
3117 		    // result is empty.
3118 		    if (n1 >= len || n1 < 0)
3119 			s = NULL;
3120 		    else
3121 			s = vim_strnsave(s + n1, 1);
3122 		}
3123 		clear_tv(rettv);
3124 		rettv->v_type = VAR_STRING;
3125 		rettv->vval.v_string = s;
3126 		break;
3127 
3128 	    case VAR_BLOB:
3129 		len = blob_len(rettv->vval.v_blob);
3130 		if (range)
3131 		{
3132 		    // The resulting variable is a sub-blob.  If the indexes
3133 		    // are out of range the result is empty.
3134 		    if (n1 < 0)
3135 		    {
3136 			n1 = len + n1;
3137 			if (n1 < 0)
3138 			    n1 = 0;
3139 		    }
3140 		    if (n2 < 0)
3141 			n2 = len + n2;
3142 		    else if (n2 >= len)
3143 			n2 = len - 1;
3144 		    if (n1 >= len || n2 < 0 || n1 > n2)
3145 		    {
3146 			clear_tv(rettv);
3147 			rettv->v_type = VAR_BLOB;
3148 			rettv->vval.v_blob = NULL;
3149 		    }
3150 		    else
3151 		    {
3152 			blob_T  *blob = blob_alloc();
3153 
3154 			if (blob != NULL)
3155 			{
3156 			    if (ga_grow(&blob->bv_ga, n2 - n1 + 1) == FAIL)
3157 			    {
3158 				blob_free(blob);
3159 				return FAIL;
3160 			    }
3161 			    blob->bv_ga.ga_len = n2 - n1 + 1;
3162 			    for (i = n1; i <= n2; i++)
3163 				blob_set(blob, i - n1,
3164 					      blob_get(rettv->vval.v_blob, i));
3165 
3166 			    clear_tv(rettv);
3167 			    rettv_blob_set(rettv, blob);
3168 			}
3169 		    }
3170 		}
3171 		else
3172 		{
3173 		    // The resulting variable is a byte value.
3174 		    // If the index is too big or negative that is an error.
3175 		    if (n1 < 0)
3176 			n1 = len + n1;
3177 		    if (n1 < len && n1 >= 0)
3178 		    {
3179 			int v = blob_get(rettv->vval.v_blob, n1);
3180 
3181 			clear_tv(rettv);
3182 			rettv->v_type = VAR_NUMBER;
3183 			rettv->vval.v_number = v;
3184 		    }
3185 		    else
3186 			semsg(_(e_blobidx), n1);
3187 		}
3188 		break;
3189 
3190 	    case VAR_LIST:
3191 		len = list_len(rettv->vval.v_list);
3192 		if (n1 < 0)
3193 		    n1 = len + n1;
3194 		if (!empty1 && (n1 < 0 || n1 >= len))
3195 		{
3196 		    // For a range we allow invalid values and return an empty
3197 		    // list.  A list index out of range is an error.
3198 		    if (!range)
3199 		    {
3200 			if (verbose)
3201 			    semsg(_(e_listidx), n1);
3202 			return FAIL;
3203 		    }
3204 		    n1 = len;
3205 		}
3206 		if (range)
3207 		{
3208 		    list_T	*l;
3209 		    listitem_T	*item;
3210 
3211 		    if (n2 < 0)
3212 			n2 = len + n2;
3213 		    else if (n2 >= len)
3214 			n2 = len - 1;
3215 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
3216 			n2 = -1;
3217 		    l = list_alloc();
3218 		    if (l == NULL)
3219 			return FAIL;
3220 		    for (item = list_find(rettv->vval.v_list, n1);
3221 							       n1 <= n2; ++n1)
3222 		    {
3223 			if (list_append_tv(l, &item->li_tv) == FAIL)
3224 			{
3225 			    list_free(l);
3226 			    return FAIL;
3227 			}
3228 			item = item->li_next;
3229 		    }
3230 		    clear_tv(rettv);
3231 		    rettv_list_set(rettv, l);
3232 		}
3233 		else
3234 		{
3235 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
3236 		    clear_tv(rettv);
3237 		    *rettv = var1;
3238 		}
3239 		break;
3240 
3241 	    case VAR_DICT:
3242 		if (range)
3243 		{
3244 		    if (verbose)
3245 			emsg(_(e_dictrange));
3246 		    if (len == -1)
3247 			clear_tv(&var1);
3248 		    return FAIL;
3249 		}
3250 		{
3251 		    dictitem_T	*item;
3252 
3253 		    if (len == -1)
3254 		    {
3255 			key = tv_get_string_chk(&var1);
3256 			if (key == NULL)
3257 			{
3258 			    clear_tv(&var1);
3259 			    return FAIL;
3260 			}
3261 		    }
3262 
3263 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
3264 
3265 		    if (item == NULL && verbose)
3266 			semsg(_(e_dictkey), key);
3267 		    if (len == -1)
3268 			clear_tv(&var1);
3269 		    if (item == NULL)
3270 			return FAIL;
3271 
3272 		    copy_tv(&item->di_tv, &var1);
3273 		    clear_tv(rettv);
3274 		    *rettv = var1;
3275 		}
3276 		break;
3277 	}
3278     }
3279 
3280     return OK;
3281 }
3282 
3283 /*
3284  * Get an option value.
3285  * "arg" points to the '&' or '+' before the option name.
3286  * "arg" is advanced to character after the option name.
3287  * Return OK or FAIL.
3288  */
3289     int
3290 get_option_tv(
3291     char_u	**arg,
3292     typval_T	*rettv,	// when NULL, only check if option exists
3293     int		evaluate)
3294 {
3295     char_u	*option_end;
3296     long	numval;
3297     char_u	*stringval;
3298     int		opt_type;
3299     int		c;
3300     int		working = (**arg == '+');    // has("+option")
3301     int		ret = OK;
3302     int		opt_flags;
3303 
3304     /*
3305      * Isolate the option name and find its value.
3306      */
3307     option_end = find_option_end(arg, &opt_flags);
3308     if (option_end == NULL)
3309     {
3310 	if (rettv != NULL)
3311 	    semsg(_("E112: Option name missing: %s"), *arg);
3312 	return FAIL;
3313     }
3314 
3315     if (!evaluate)
3316     {
3317 	*arg = option_end;
3318 	return OK;
3319     }
3320 
3321     c = *option_end;
3322     *option_end = NUL;
3323     opt_type = get_option_value(*arg, &numval,
3324 			       rettv == NULL ? NULL : &stringval, opt_flags);
3325 
3326     if (opt_type == -3)			// invalid name
3327     {
3328 	if (rettv != NULL)
3329 	    semsg(_(e_unknown_option), *arg);
3330 	ret = FAIL;
3331     }
3332     else if (rettv != NULL)
3333     {
3334 	if (opt_type == -2)		// hidden string option
3335 	{
3336 	    rettv->v_type = VAR_STRING;
3337 	    rettv->vval.v_string = NULL;
3338 	}
3339 	else if (opt_type == -1)	// hidden number option
3340 	{
3341 	    rettv->v_type = VAR_NUMBER;
3342 	    rettv->vval.v_number = 0;
3343 	}
3344 	else if (opt_type == 1)		// number option
3345 	{
3346 	    rettv->v_type = VAR_NUMBER;
3347 	    rettv->vval.v_number = numval;
3348 	}
3349 	else				// string option
3350 	{
3351 	    rettv->v_type = VAR_STRING;
3352 	    rettv->vval.v_string = stringval;
3353 	}
3354     }
3355     else if (working && (opt_type == -2 || opt_type == -1))
3356 	ret = FAIL;
3357 
3358     *option_end = c;		    // put back for error messages
3359     *arg = option_end;
3360 
3361     return ret;
3362 }
3363 
3364 /*
3365  * Allocate a variable for a number constant.  Also deals with "0z" for blob.
3366  * Return OK or FAIL.
3367  */
3368     int
3369 get_number_tv(
3370 	char_u	    **arg,
3371 	typval_T    *rettv,
3372 	int	    evaluate,
3373 	int	    want_string UNUSED)
3374 {
3375     int		len;
3376 #ifdef FEAT_FLOAT
3377     char_u	*p;
3378     int		get_float = FALSE;
3379 
3380     // We accept a float when the format matches
3381     // "[0-9]\+\.[0-9]\+\([eE][+-]\?[0-9]\+\)\?".  This is very
3382     // strict to avoid backwards compatibility problems.
3383     // With script version 2 and later the leading digit can be
3384     // omitted.
3385     // Don't look for a float after the "." operator, so that
3386     // ":let vers = 1.2.3" doesn't fail.
3387     if (**arg == '.')
3388 	p = *arg;
3389     else
3390 	p = skipdigits(*arg + 1);
3391     if (!want_string && p[0] == '.' && vim_isdigit(p[1]))
3392     {
3393 	get_float = TRUE;
3394 	p = skipdigits(p + 2);
3395 	if (*p == 'e' || *p == 'E')
3396 	{
3397 	    ++p;
3398 	    if (*p == '-' || *p == '+')
3399 		++p;
3400 	    if (!vim_isdigit(*p))
3401 		get_float = FALSE;
3402 	    else
3403 		p = skipdigits(p + 1);
3404 	}
3405 	if (ASCII_ISALPHA(*p) || *p == '.')
3406 	    get_float = FALSE;
3407     }
3408     if (get_float)
3409     {
3410 	float_T	f;
3411 
3412 	*arg += string2float(*arg, &f);
3413 	if (evaluate)
3414 	{
3415 	    rettv->v_type = VAR_FLOAT;
3416 	    rettv->vval.v_float = f;
3417 	}
3418     }
3419     else
3420 #endif
3421     if (**arg == '0' && ((*arg)[1] == 'z' || (*arg)[1] == 'Z'))
3422     {
3423 	char_u  *bp;
3424 	blob_T  *blob = NULL;  // init for gcc
3425 
3426 	// Blob constant: 0z0123456789abcdef
3427 	if (evaluate)
3428 	    blob = blob_alloc();
3429 	for (bp = *arg + 2; vim_isxdigit(bp[0]); bp += 2)
3430 	{
3431 	    if (!vim_isxdigit(bp[1]))
3432 	    {
3433 		if (blob != NULL)
3434 		{
3435 		    emsg(_("E973: Blob literal should have an even number of hex characters"));
3436 		    ga_clear(&blob->bv_ga);
3437 		    VIM_CLEAR(blob);
3438 		}
3439 		return FAIL;
3440 	    }
3441 	    if (blob != NULL)
3442 		ga_append(&blob->bv_ga,
3443 			     (hex2nr(*bp) << 4) + hex2nr(*(bp+1)));
3444 	    if (bp[2] == '.' && vim_isxdigit(bp[3]))
3445 		++bp;
3446 	}
3447 	if (blob != NULL)
3448 	    rettv_blob_set(rettv, blob);
3449 	*arg = bp;
3450     }
3451     else
3452     {
3453 	varnumber_T	n;
3454 
3455 	// decimal, hex or octal number
3456 	vim_str2nr(*arg, NULL, &len, current_sctx.sc_version >= 4
3457 		      ? STR2NR_NO_OCT + STR2NR_QUOTE
3458 		      : STR2NR_ALL, &n, NULL, 0, TRUE);
3459 	if (len == 0)
3460 	{
3461 	    semsg(_(e_invexpr2), *arg);
3462 	    return FAIL;
3463 	}
3464 	*arg += len;
3465 	if (evaluate)
3466 	{
3467 	    rettv->v_type = VAR_NUMBER;
3468 	    rettv->vval.v_number = n;
3469 	}
3470     }
3471     return OK;
3472 }
3473 
3474 /*
3475  * Allocate a variable for a string constant.
3476  * Return OK or FAIL.
3477  */
3478     int
3479 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
3480 {
3481     char_u	*p;
3482     char_u	*name;
3483     int		extra = 0;
3484 
3485     /*
3486      * Find the end of the string, skipping backslashed characters.
3487      */
3488     for (p = *arg + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
3489     {
3490 	if (*p == '\\' && p[1] != NUL)
3491 	{
3492 	    ++p;
3493 	    // A "\<x>" form occupies at least 4 characters, and produces up
3494 	    // to 6 characters: reserve space for 2 extra
3495 	    if (*p == '<')
3496 		extra += 2;
3497 	}
3498     }
3499 
3500     if (*p != '"')
3501     {
3502 	semsg(_("E114: Missing quote: %s"), *arg);
3503 	return FAIL;
3504     }
3505 
3506     // If only parsing, set *arg and return here
3507     if (!evaluate)
3508     {
3509 	*arg = p + 1;
3510 	return OK;
3511     }
3512 
3513     /*
3514      * Copy the string into allocated memory, handling backslashed
3515      * characters.
3516      */
3517     name = alloc(p - *arg + extra);
3518     if (name == NULL)
3519 	return FAIL;
3520     rettv->v_type = VAR_STRING;
3521     rettv->vval.v_string = name;
3522 
3523     for (p = *arg + 1; *p != NUL && *p != '"'; )
3524     {
3525 	if (*p == '\\')
3526 	{
3527 	    switch (*++p)
3528 	    {
3529 		case 'b': *name++ = BS; ++p; break;
3530 		case 'e': *name++ = ESC; ++p; break;
3531 		case 'f': *name++ = FF; ++p; break;
3532 		case 'n': *name++ = NL; ++p; break;
3533 		case 'r': *name++ = CAR; ++p; break;
3534 		case 't': *name++ = TAB; ++p; break;
3535 
3536 		case 'X': // hex: "\x1", "\x12"
3537 		case 'x':
3538 		case 'u': // Unicode: "\u0023"
3539 		case 'U':
3540 			  if (vim_isxdigit(p[1]))
3541 			  {
3542 			      int	n, nr;
3543 			      int	c = toupper(*p);
3544 
3545 			      if (c == 'X')
3546 				  n = 2;
3547 			      else if (*p == 'u')
3548 				  n = 4;
3549 			      else
3550 				  n = 8;
3551 			      nr = 0;
3552 			      while (--n >= 0 && vim_isxdigit(p[1]))
3553 			      {
3554 				  ++p;
3555 				  nr = (nr << 4) + hex2nr(*p);
3556 			      }
3557 			      ++p;
3558 			      // For "\u" store the number according to
3559 			      // 'encoding'.
3560 			      if (c != 'X')
3561 				  name += (*mb_char2bytes)(nr, name);
3562 			      else
3563 				  *name++ = nr;
3564 			  }
3565 			  break;
3566 
3567 			  // octal: "\1", "\12", "\123"
3568 		case '0':
3569 		case '1':
3570 		case '2':
3571 		case '3':
3572 		case '4':
3573 		case '5':
3574 		case '6':
3575 		case '7': *name = *p++ - '0';
3576 			  if (*p >= '0' && *p <= '7')
3577 			  {
3578 			      *name = (*name << 3) + *p++ - '0';
3579 			      if (*p >= '0' && *p <= '7')
3580 				  *name = (*name << 3) + *p++ - '0';
3581 			  }
3582 			  ++name;
3583 			  break;
3584 
3585 			    // Special key, e.g.: "\<C-W>"
3586 		case '<': extra = trans_special(&p, name, TRUE, TRUE,
3587 								   TRUE, NULL);
3588 			  if (extra != 0)
3589 			  {
3590 			      name += extra;
3591 			      break;
3592 			  }
3593 			  // FALLTHROUGH
3594 
3595 		default:  MB_COPY_CHAR(p, name);
3596 			  break;
3597 	    }
3598 	}
3599 	else
3600 	    MB_COPY_CHAR(p, name);
3601 
3602     }
3603     *name = NUL;
3604     if (*p != NUL) // just in case
3605 	++p;
3606     *arg = p;
3607 
3608     return OK;
3609 }
3610 
3611 /*
3612  * Allocate a variable for a 'str''ing' constant.
3613  * Return OK or FAIL.
3614  */
3615     int
3616 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
3617 {
3618     char_u	*p;
3619     char_u	*str;
3620     int		reduce = 0;
3621 
3622     /*
3623      * Find the end of the string, skipping ''.
3624      */
3625     for (p = *arg + 1; *p != NUL; MB_PTR_ADV(p))
3626     {
3627 	if (*p == '\'')
3628 	{
3629 	    if (p[1] != '\'')
3630 		break;
3631 	    ++reduce;
3632 	    ++p;
3633 	}
3634     }
3635 
3636     if (*p != '\'')
3637     {
3638 	semsg(_("E115: Missing quote: %s"), *arg);
3639 	return FAIL;
3640     }
3641 
3642     // If only parsing return after setting "*arg"
3643     if (!evaluate)
3644     {
3645 	*arg = p + 1;
3646 	return OK;
3647     }
3648 
3649     /*
3650      * Copy the string into allocated memory, handling '' to ' reduction.
3651      */
3652     str = alloc((p - *arg) - reduce);
3653     if (str == NULL)
3654 	return FAIL;
3655     rettv->v_type = VAR_STRING;
3656     rettv->vval.v_string = str;
3657 
3658     for (p = *arg + 1; *p != NUL; )
3659     {
3660 	if (*p == '\'')
3661 	{
3662 	    if (p[1] != '\'')
3663 		break;
3664 	    ++p;
3665 	}
3666 	MB_COPY_CHAR(p, str);
3667     }
3668     *str = NUL;
3669     *arg = p + 1;
3670 
3671     return OK;
3672 }
3673 
3674 /*
3675  * Return the function name of partial "pt".
3676  */
3677     char_u *
3678 partial_name(partial_T *pt)
3679 {
3680     if (pt->pt_name != NULL)
3681 	return pt->pt_name;
3682     return pt->pt_func->uf_name;
3683 }
3684 
3685     static void
3686 partial_free(partial_T *pt)
3687 {
3688     int i;
3689 
3690     for (i = 0; i < pt->pt_argc; ++i)
3691 	clear_tv(&pt->pt_argv[i]);
3692     vim_free(pt->pt_argv);
3693     dict_unref(pt->pt_dict);
3694     if (pt->pt_name != NULL)
3695     {
3696 	func_unref(pt->pt_name);
3697 	vim_free(pt->pt_name);
3698     }
3699     else
3700 	func_ptr_unref(pt->pt_func);
3701     vim_free(pt);
3702 }
3703 
3704 /*
3705  * Unreference a closure: decrement the reference count and free it when it
3706  * becomes zero.
3707  */
3708     void
3709 partial_unref(partial_T *pt)
3710 {
3711     if (pt != NULL && --pt->pt_refcount <= 0)
3712 	partial_free(pt);
3713 }
3714 
3715 static int tv_equal_recurse_limit;
3716 
3717     static int
3718 func_equal(
3719     typval_T *tv1,
3720     typval_T *tv2,
3721     int	     ic)	    // ignore case
3722 {
3723     char_u	*s1, *s2;
3724     dict_T	*d1, *d2;
3725     int		a1, a2;
3726     int		i;
3727 
3728     // empty and NULL function name considered the same
3729     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
3730 					   : partial_name(tv1->vval.v_partial);
3731     if (s1 != NULL && *s1 == NUL)
3732 	s1 = NULL;
3733     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
3734 					   : partial_name(tv2->vval.v_partial);
3735     if (s2 != NULL && *s2 == NUL)
3736 	s2 = NULL;
3737     if (s1 == NULL || s2 == NULL)
3738     {
3739 	if (s1 != s2)
3740 	    return FALSE;
3741     }
3742     else if (STRCMP(s1, s2) != 0)
3743 	return FALSE;
3744 
3745     // empty dict and NULL dict is different
3746     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
3747     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
3748     if (d1 == NULL || d2 == NULL)
3749     {
3750 	if (d1 != d2)
3751 	    return FALSE;
3752     }
3753     else if (!dict_equal(d1, d2, ic, TRUE))
3754 	return FALSE;
3755 
3756     // empty list and no list considered the same
3757     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
3758     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
3759     if (a1 != a2)
3760 	return FALSE;
3761     for (i = 0; i < a1; ++i)
3762 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
3763 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
3764 	    return FALSE;
3765 
3766     return TRUE;
3767 }
3768 
3769 /*
3770  * Return TRUE if "tv1" and "tv2" have the same value.
3771  * Compares the items just like "==" would compare them, but strings and
3772  * numbers are different.  Floats and numbers are also different.
3773  */
3774     int
3775 tv_equal(
3776     typval_T *tv1,
3777     typval_T *tv2,
3778     int	     ic,	    // ignore case
3779     int	     recursive)	    // TRUE when used recursively
3780 {
3781     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3782     char_u	*s1, *s2;
3783     static int  recursive_cnt = 0;	    // catch recursive loops
3784     int		r;
3785 
3786     // Catch lists and dicts that have an endless loop by limiting
3787     // recursiveness to a limit.  We guess they are equal then.
3788     // A fixed limit has the problem of still taking an awful long time.
3789     // Reduce the limit every time running into it. That should work fine for
3790     // deeply linked structures that are not recursively linked and catch
3791     // recursiveness quickly.
3792     if (!recursive)
3793 	tv_equal_recurse_limit = 1000;
3794     if (recursive_cnt >= tv_equal_recurse_limit)
3795     {
3796 	--tv_equal_recurse_limit;
3797 	return TRUE;
3798     }
3799 
3800     // For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
3801     // arguments.
3802     if ((tv1->v_type == VAR_FUNC
3803 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
3804 	    && (tv2->v_type == VAR_FUNC
3805 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
3806     {
3807 	++recursive_cnt;
3808 	r = func_equal(tv1, tv2, ic);
3809 	--recursive_cnt;
3810 	return r;
3811     }
3812 
3813     if (tv1->v_type != tv2->v_type)
3814 	return FALSE;
3815 
3816     switch (tv1->v_type)
3817     {
3818 	case VAR_LIST:
3819 	    ++recursive_cnt;
3820 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
3821 	    --recursive_cnt;
3822 	    return r;
3823 
3824 	case VAR_DICT:
3825 	    ++recursive_cnt;
3826 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
3827 	    --recursive_cnt;
3828 	    return r;
3829 
3830 	case VAR_BLOB:
3831 	    return blob_equal(tv1->vval.v_blob, tv2->vval.v_blob);
3832 
3833 	case VAR_NUMBER:
3834 	case VAR_BOOL:
3835 	case VAR_SPECIAL:
3836 	    return tv1->vval.v_number == tv2->vval.v_number;
3837 
3838 	case VAR_STRING:
3839 	    s1 = tv_get_string_buf(tv1, buf1);
3840 	    s2 = tv_get_string_buf(tv2, buf2);
3841 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
3842 
3843 	case VAR_FLOAT:
3844 #ifdef FEAT_FLOAT
3845 	    return tv1->vval.v_float == tv2->vval.v_float;
3846 #endif
3847 	case VAR_JOB:
3848 #ifdef FEAT_JOB_CHANNEL
3849 	    return tv1->vval.v_job == tv2->vval.v_job;
3850 #endif
3851 	case VAR_CHANNEL:
3852 #ifdef FEAT_JOB_CHANNEL
3853 	    return tv1->vval.v_channel == tv2->vval.v_channel;
3854 #endif
3855 
3856 	case VAR_PARTIAL:
3857 	    return tv1->vval.v_partial == tv2->vval.v_partial;
3858 
3859 	case VAR_FUNC:
3860 	    return tv1->vval.v_string == tv2->vval.v_string;
3861 
3862 	case VAR_UNKNOWN:
3863 	case VAR_ANY:
3864 	case VAR_VOID:
3865 	    break;
3866     }
3867 
3868     // VAR_UNKNOWN can be the result of a invalid expression, let's say it
3869     // does not equal anything, not even itself.
3870     return FALSE;
3871 }
3872 
3873 /*
3874  * Return the next (unique) copy ID.
3875  * Used for serializing nested structures.
3876  */
3877     int
3878 get_copyID(void)
3879 {
3880     current_copyID += COPYID_INC;
3881     return current_copyID;
3882 }
3883 
3884 /*
3885  * Garbage collection for lists and dictionaries.
3886  *
3887  * We use reference counts to be able to free most items right away when they
3888  * are no longer used.  But for composite items it's possible that it becomes
3889  * unused while the reference count is > 0: When there is a recursive
3890  * reference.  Example:
3891  *	:let l = [1, 2, 3]
3892  *	:let d = {9: l}
3893  *	:let l[1] = d
3894  *
3895  * Since this is quite unusual we handle this with garbage collection: every
3896  * once in a while find out which lists and dicts are not referenced from any
3897  * variable.
3898  *
3899  * Here is a good reference text about garbage collection (refers to Python
3900  * but it applies to all reference-counting mechanisms):
3901  *	http://python.ca/nas/python/gc/
3902  */
3903 
3904 /*
3905  * Do garbage collection for lists and dicts.
3906  * When "testing" is TRUE this is called from test_garbagecollect_now().
3907  * Return TRUE if some memory was freed.
3908  */
3909     int
3910 garbage_collect(int testing)
3911 {
3912     int		copyID;
3913     int		abort = FALSE;
3914     buf_T	*buf;
3915     win_T	*wp;
3916     int		did_free = FALSE;
3917     tabpage_T	*tp;
3918 
3919     if (!testing)
3920     {
3921 	// Only do this once.
3922 	want_garbage_collect = FALSE;
3923 	may_garbage_collect = FALSE;
3924 	garbage_collect_at_exit = FALSE;
3925     }
3926 
3927     // The execution stack can grow big, limit the size.
3928     if (exestack.ga_maxlen - exestack.ga_len > 500)
3929     {
3930 	size_t	new_len;
3931 	char_u	*pp;
3932 	int	n;
3933 
3934 	// Keep 150% of the current size, with a minimum of the growth size.
3935 	n = exestack.ga_len / 2;
3936 	if (n < exestack.ga_growsize)
3937 	    n = exestack.ga_growsize;
3938 
3939 	// Don't make it bigger though.
3940 	if (exestack.ga_len + n < exestack.ga_maxlen)
3941 	{
3942 	    new_len = exestack.ga_itemsize * (exestack.ga_len + n);
3943 	    pp = vim_realloc(exestack.ga_data, new_len);
3944 	    if (pp == NULL)
3945 		return FAIL;
3946 	    exestack.ga_maxlen = exestack.ga_len + n;
3947 	    exestack.ga_data = pp;
3948 	}
3949     }
3950 
3951     // We advance by two because we add one for items referenced through
3952     // previous_funccal.
3953     copyID = get_copyID();
3954 
3955     /*
3956      * 1. Go through all accessible variables and mark all lists and dicts
3957      *    with copyID.
3958      */
3959 
3960     // Don't free variables in the previous_funccal list unless they are only
3961     // referenced through previous_funccal.  This must be first, because if
3962     // the item is referenced elsewhere the funccal must not be freed.
3963     abort = abort || set_ref_in_previous_funccal(copyID);
3964 
3965     // script-local variables
3966     abort = abort || garbage_collect_scriptvars(copyID);
3967 
3968     // buffer-local variables
3969     FOR_ALL_BUFFERS(buf)
3970 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
3971 								  NULL, NULL);
3972 
3973     // window-local variables
3974     FOR_ALL_TAB_WINDOWS(tp, wp)
3975 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3976 								  NULL, NULL);
3977     if (aucmd_win != NULL)
3978 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
3979 								  NULL, NULL);
3980 #ifdef FEAT_PROP_POPUP
3981     FOR_ALL_POPUPWINS(wp)
3982 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3983 								  NULL, NULL);
3984     FOR_ALL_TABPAGES(tp)
3985 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
3986 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3987 								  NULL, NULL);
3988 #endif
3989 
3990     // tabpage-local variables
3991     FOR_ALL_TABPAGES(tp)
3992 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
3993 								  NULL, NULL);
3994     // global variables
3995     abort = abort || garbage_collect_globvars(copyID);
3996 
3997     // function-local variables
3998     abort = abort || set_ref_in_call_stack(copyID);
3999 
4000     // named functions (matters for closures)
4001     abort = abort || set_ref_in_functions(copyID);
4002 
4003     // function call arguments, if v:testing is set.
4004     abort = abort || set_ref_in_func_args(copyID);
4005 
4006     // v: vars
4007     abort = abort || garbage_collect_vimvars(copyID);
4008 
4009     // callbacks in buffers
4010     abort = abort || set_ref_in_buffers(copyID);
4011 
4012 #ifdef FEAT_LUA
4013     abort = abort || set_ref_in_lua(copyID);
4014 #endif
4015 
4016 #ifdef FEAT_PYTHON
4017     abort = abort || set_ref_in_python(copyID);
4018 #endif
4019 
4020 #ifdef FEAT_PYTHON3
4021     abort = abort || set_ref_in_python3(copyID);
4022 #endif
4023 
4024 #ifdef FEAT_JOB_CHANNEL
4025     abort = abort || set_ref_in_channel(copyID);
4026     abort = abort || set_ref_in_job(copyID);
4027 #endif
4028 #ifdef FEAT_NETBEANS_INTG
4029     abort = abort || set_ref_in_nb_channel(copyID);
4030 #endif
4031 
4032 #ifdef FEAT_TIMERS
4033     abort = abort || set_ref_in_timer(copyID);
4034 #endif
4035 
4036 #ifdef FEAT_QUICKFIX
4037     abort = abort || set_ref_in_quickfix(copyID);
4038 #endif
4039 
4040 #ifdef FEAT_TERMINAL
4041     abort = abort || set_ref_in_term(copyID);
4042 #endif
4043 
4044 #ifdef FEAT_PROP_POPUP
4045     abort = abort || set_ref_in_popups(copyID);
4046 #endif
4047 
4048     if (!abort)
4049     {
4050 	/*
4051 	 * 2. Free lists and dictionaries that are not referenced.
4052 	 */
4053 	did_free = free_unref_items(copyID);
4054 
4055 	/*
4056 	 * 3. Check if any funccal can be freed now.
4057 	 *    This may call us back recursively.
4058 	 */
4059 	free_unref_funccal(copyID, testing);
4060     }
4061     else if (p_verbose > 0)
4062     {
4063 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
4064     }
4065 
4066     return did_free;
4067 }
4068 
4069 /*
4070  * Free lists, dictionaries, channels and jobs that are no longer referenced.
4071  */
4072     static int
4073 free_unref_items(int copyID)
4074 {
4075     int		did_free = FALSE;
4076 
4077     // Let all "free" functions know that we are here.  This means no
4078     // dictionaries, lists, channels or jobs are to be freed, because we will
4079     // do that here.
4080     in_free_unref_items = TRUE;
4081 
4082     /*
4083      * PASS 1: free the contents of the items.  We don't free the items
4084      * themselves yet, so that it is possible to decrement refcount counters
4085      */
4086 
4087     // Go through the list of dicts and free items without the copyID.
4088     did_free |= dict_free_nonref(copyID);
4089 
4090     // Go through the list of lists and free items without the copyID.
4091     did_free |= list_free_nonref(copyID);
4092 
4093 #ifdef FEAT_JOB_CHANNEL
4094     // Go through the list of jobs and free items without the copyID. This
4095     // must happen before doing channels, because jobs refer to channels, but
4096     // the reference from the channel to the job isn't tracked.
4097     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4098 
4099     // Go through the list of channels and free items without the copyID.
4100     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4101 #endif
4102 
4103     /*
4104      * PASS 2: free the items themselves.
4105      */
4106     dict_free_items(copyID);
4107     list_free_items(copyID);
4108 
4109 #ifdef FEAT_JOB_CHANNEL
4110     // Go through the list of jobs and free items without the copyID. This
4111     // must happen before doing channels, because jobs refer to channels, but
4112     // the reference from the channel to the job isn't tracked.
4113     free_unused_jobs(copyID, COPYID_MASK);
4114 
4115     // Go through the list of channels and free items without the copyID.
4116     free_unused_channels(copyID, COPYID_MASK);
4117 #endif
4118 
4119     in_free_unref_items = FALSE;
4120 
4121     return did_free;
4122 }
4123 
4124 /*
4125  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4126  * "list_stack" is used to add lists to be marked.  Can be NULL.
4127  *
4128  * Returns TRUE if setting references failed somehow.
4129  */
4130     int
4131 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4132 {
4133     int		todo;
4134     int		abort = FALSE;
4135     hashitem_T	*hi;
4136     hashtab_T	*cur_ht;
4137     ht_stack_T	*ht_stack = NULL;
4138     ht_stack_T	*tempitem;
4139 
4140     cur_ht = ht;
4141     for (;;)
4142     {
4143 	if (!abort)
4144 	{
4145 	    // Mark each item in the hashtab.  If the item contains a hashtab
4146 	    // it is added to ht_stack, if it contains a list it is added to
4147 	    // list_stack.
4148 	    todo = (int)cur_ht->ht_used;
4149 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4150 		if (!HASHITEM_EMPTY(hi))
4151 		{
4152 		    --todo;
4153 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4154 						       &ht_stack, list_stack);
4155 		}
4156 	}
4157 
4158 	if (ht_stack == NULL)
4159 	    break;
4160 
4161 	// take an item from the stack
4162 	cur_ht = ht_stack->ht;
4163 	tempitem = ht_stack;
4164 	ht_stack = ht_stack->prev;
4165 	free(tempitem);
4166     }
4167 
4168     return abort;
4169 }
4170 
4171 /*
4172  * Mark a dict and its items with "copyID".
4173  * Returns TRUE if setting references failed somehow.
4174  */
4175     int
4176 set_ref_in_dict(dict_T *d, int copyID)
4177 {
4178     if (d != NULL && d->dv_copyID != copyID)
4179     {
4180 	d->dv_copyID = copyID;
4181 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4182     }
4183     return FALSE;
4184 }
4185 
4186 /*
4187  * Mark a list and its items with "copyID".
4188  * Returns TRUE if setting references failed somehow.
4189  */
4190     int
4191 set_ref_in_list(list_T *ll, int copyID)
4192 {
4193     if (ll != NULL && ll->lv_copyID != copyID)
4194     {
4195 	ll->lv_copyID = copyID;
4196 	return set_ref_in_list_items(ll, copyID, NULL);
4197     }
4198     return FALSE;
4199 }
4200 
4201 /*
4202  * Mark all lists and dicts referenced through list "l" with "copyID".
4203  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4204  *
4205  * Returns TRUE if setting references failed somehow.
4206  */
4207     int
4208 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4209 {
4210     listitem_T	 *li;
4211     int		 abort = FALSE;
4212     list_T	 *cur_l;
4213     list_stack_T *list_stack = NULL;
4214     list_stack_T *tempitem;
4215 
4216     cur_l = l;
4217     for (;;)
4218     {
4219 	if (!abort && cur_l->lv_first != &range_list_item)
4220 	    // Mark each item in the list.  If the item contains a hashtab
4221 	    // it is added to ht_stack, if it contains a list it is added to
4222 	    // list_stack.
4223 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4224 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4225 						       ht_stack, &list_stack);
4226 	if (list_stack == NULL)
4227 	    break;
4228 
4229 	// take an item from the stack
4230 	cur_l = list_stack->list;
4231 	tempitem = list_stack;
4232 	list_stack = list_stack->prev;
4233 	free(tempitem);
4234     }
4235 
4236     return abort;
4237 }
4238 
4239 /*
4240  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4241  * "list_stack" is used to add lists to be marked.  Can be NULL.
4242  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4243  *
4244  * Returns TRUE if setting references failed somehow.
4245  */
4246     int
4247 set_ref_in_item(
4248     typval_T	    *tv,
4249     int		    copyID,
4250     ht_stack_T	    **ht_stack,
4251     list_stack_T    **list_stack)
4252 {
4253     int		abort = FALSE;
4254 
4255     if (tv->v_type == VAR_DICT)
4256     {
4257 	dict_T	*dd = tv->vval.v_dict;
4258 
4259 	if (dd != NULL && dd->dv_copyID != copyID)
4260 	{
4261 	    // Didn't see this dict yet.
4262 	    dd->dv_copyID = copyID;
4263 	    if (ht_stack == NULL)
4264 	    {
4265 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4266 	    }
4267 	    else
4268 	    {
4269 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
4270 		if (newitem == NULL)
4271 		    abort = TRUE;
4272 		else
4273 		{
4274 		    newitem->ht = &dd->dv_hashtab;
4275 		    newitem->prev = *ht_stack;
4276 		    *ht_stack = newitem;
4277 		}
4278 	    }
4279 	}
4280     }
4281     else if (tv->v_type == VAR_LIST)
4282     {
4283 	list_T	*ll = tv->vval.v_list;
4284 
4285 	if (ll != NULL && ll->lv_copyID != copyID)
4286 	{
4287 	    // Didn't see this list yet.
4288 	    ll->lv_copyID = copyID;
4289 	    if (list_stack == NULL)
4290 	    {
4291 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4292 	    }
4293 	    else
4294 	    {
4295 		list_stack_T *newitem = (list_stack_T*)malloc(
4296 							sizeof(list_stack_T));
4297 		if (newitem == NULL)
4298 		    abort = TRUE;
4299 		else
4300 		{
4301 		    newitem->list = ll;
4302 		    newitem->prev = *list_stack;
4303 		    *list_stack = newitem;
4304 		}
4305 	    }
4306 	}
4307     }
4308     else if (tv->v_type == VAR_FUNC)
4309     {
4310 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4311     }
4312     else if (tv->v_type == VAR_PARTIAL)
4313     {
4314 	partial_T	*pt = tv->vval.v_partial;
4315 	int		i;
4316 
4317 	// A partial does not have a copyID, because it cannot contain itself.
4318 	if (pt != NULL)
4319 	{
4320 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4321 
4322 	    if (pt->pt_dict != NULL)
4323 	    {
4324 		typval_T dtv;
4325 
4326 		dtv.v_type = VAR_DICT;
4327 		dtv.vval.v_dict = pt->pt_dict;
4328 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4329 	    }
4330 
4331 	    for (i = 0; i < pt->pt_argc; ++i)
4332 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4333 							ht_stack, list_stack);
4334 	}
4335     }
4336 #ifdef FEAT_JOB_CHANNEL
4337     else if (tv->v_type == VAR_JOB)
4338     {
4339 	job_T	    *job = tv->vval.v_job;
4340 	typval_T    dtv;
4341 
4342 	if (job != NULL && job->jv_copyID != copyID)
4343 	{
4344 	    job->jv_copyID = copyID;
4345 	    if (job->jv_channel != NULL)
4346 	    {
4347 		dtv.v_type = VAR_CHANNEL;
4348 		dtv.vval.v_channel = job->jv_channel;
4349 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4350 	    }
4351 	    if (job->jv_exit_cb.cb_partial != NULL)
4352 	    {
4353 		dtv.v_type = VAR_PARTIAL;
4354 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4355 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4356 	    }
4357 	}
4358     }
4359     else if (tv->v_type == VAR_CHANNEL)
4360     {
4361 	channel_T   *ch =tv->vval.v_channel;
4362 	ch_part_T   part;
4363 	typval_T    dtv;
4364 	jsonq_T	    *jq;
4365 	cbq_T	    *cq;
4366 
4367 	if (ch != NULL && ch->ch_copyID != copyID)
4368 	{
4369 	    ch->ch_copyID = copyID;
4370 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4371 	    {
4372 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4373 							     jq = jq->jq_next)
4374 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4375 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4376 							     cq = cq->cq_next)
4377 		    if (cq->cq_callback.cb_partial != NULL)
4378 		    {
4379 			dtv.v_type = VAR_PARTIAL;
4380 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4381 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4382 		    }
4383 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4384 		{
4385 		    dtv.v_type = VAR_PARTIAL;
4386 		    dtv.vval.v_partial =
4387 				      ch->ch_part[part].ch_callback.cb_partial;
4388 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4389 		}
4390 	    }
4391 	    if (ch->ch_callback.cb_partial != NULL)
4392 	    {
4393 		dtv.v_type = VAR_PARTIAL;
4394 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4395 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4396 	    }
4397 	    if (ch->ch_close_cb.cb_partial != NULL)
4398 	    {
4399 		dtv.v_type = VAR_PARTIAL;
4400 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4401 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4402 	    }
4403 	}
4404     }
4405 #endif
4406     return abort;
4407 }
4408 
4409 /*
4410  * Return a string with the string representation of a variable.
4411  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4412  * "numbuf" is used for a number.
4413  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4414  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4415  * stings as "string()", otherwise does not put quotes around strings, as
4416  * ":echo" displays values.
4417  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4418  * are replaced with "...".
4419  * May return NULL.
4420  */
4421     char_u *
4422 echo_string_core(
4423     typval_T	*tv,
4424     char_u	**tofree,
4425     char_u	*numbuf,
4426     int		copyID,
4427     int		echo_style,
4428     int		restore_copyID,
4429     int		composite_val)
4430 {
4431     static int	recurse = 0;
4432     char_u	*r = NULL;
4433 
4434     if (recurse >= DICT_MAXNEST)
4435     {
4436 	if (!did_echo_string_emsg)
4437 	{
4438 	    // Only give this message once for a recursive call to avoid
4439 	    // flooding the user with errors.  And stop iterating over lists
4440 	    // and dicts.
4441 	    did_echo_string_emsg = TRUE;
4442 	    emsg(_("E724: variable nested too deep for displaying"));
4443 	}
4444 	*tofree = NULL;
4445 	return (char_u *)"{E724}";
4446     }
4447     ++recurse;
4448 
4449     switch (tv->v_type)
4450     {
4451 	case VAR_STRING:
4452 	    if (echo_style && !composite_val)
4453 	    {
4454 		*tofree = NULL;
4455 		r = tv->vval.v_string;
4456 		if (r == NULL)
4457 		    r = (char_u *)"";
4458 	    }
4459 	    else
4460 	    {
4461 		*tofree = string_quote(tv->vval.v_string, FALSE);
4462 		r = *tofree;
4463 	    }
4464 	    break;
4465 
4466 	case VAR_FUNC:
4467 	    if (echo_style)
4468 	    {
4469 		*tofree = NULL;
4470 		r = tv->vval.v_string;
4471 	    }
4472 	    else
4473 	    {
4474 		*tofree = string_quote(tv->vval.v_string, TRUE);
4475 		r = *tofree;
4476 	    }
4477 	    break;
4478 
4479 	case VAR_PARTIAL:
4480 	    {
4481 		partial_T   *pt = tv->vval.v_partial;
4482 		char_u	    *fname = string_quote(pt == NULL ? NULL
4483 						    : partial_name(pt), FALSE);
4484 		garray_T    ga;
4485 		int	    i;
4486 		char_u	    *tf;
4487 
4488 		ga_init2(&ga, 1, 100);
4489 		ga_concat(&ga, (char_u *)"function(");
4490 		if (fname != NULL)
4491 		{
4492 		    ga_concat(&ga, fname);
4493 		    vim_free(fname);
4494 		}
4495 		if (pt != NULL && pt->pt_argc > 0)
4496 		{
4497 		    ga_concat(&ga, (char_u *)", [");
4498 		    for (i = 0; i < pt->pt_argc; ++i)
4499 		    {
4500 			if (i > 0)
4501 			    ga_concat(&ga, (char_u *)", ");
4502 			ga_concat(&ga,
4503 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
4504 			vim_free(tf);
4505 		    }
4506 		    ga_concat(&ga, (char_u *)"]");
4507 		}
4508 		if (pt != NULL && pt->pt_dict != NULL)
4509 		{
4510 		    typval_T dtv;
4511 
4512 		    ga_concat(&ga, (char_u *)", ");
4513 		    dtv.v_type = VAR_DICT;
4514 		    dtv.vval.v_dict = pt->pt_dict;
4515 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
4516 		    vim_free(tf);
4517 		}
4518 		ga_concat(&ga, (char_u *)")");
4519 
4520 		*tofree = ga.ga_data;
4521 		r = *tofree;
4522 		break;
4523 	    }
4524 
4525 	case VAR_BLOB:
4526 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
4527 	    break;
4528 
4529 	case VAR_LIST:
4530 	    if (tv->vval.v_list == NULL)
4531 	    {
4532 		// NULL list is equivalent to empty list.
4533 		*tofree = NULL;
4534 		r = (char_u *)"[]";
4535 	    }
4536 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
4537 		    && tv->vval.v_list->lv_len > 0)
4538 	    {
4539 		*tofree = NULL;
4540 		r = (char_u *)"[...]";
4541 	    }
4542 	    else
4543 	    {
4544 		int old_copyID = tv->vval.v_list->lv_copyID;
4545 
4546 		tv->vval.v_list->lv_copyID = copyID;
4547 		*tofree = list2string(tv, copyID, restore_copyID);
4548 		if (restore_copyID)
4549 		    tv->vval.v_list->lv_copyID = old_copyID;
4550 		r = *tofree;
4551 	    }
4552 	    break;
4553 
4554 	case VAR_DICT:
4555 	    if (tv->vval.v_dict == NULL)
4556 	    {
4557 		// NULL dict is equivalent to empty dict.
4558 		*tofree = NULL;
4559 		r = (char_u *)"{}";
4560 	    }
4561 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
4562 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
4563 	    {
4564 		*tofree = NULL;
4565 		r = (char_u *)"{...}";
4566 	    }
4567 	    else
4568 	    {
4569 		int old_copyID = tv->vval.v_dict->dv_copyID;
4570 
4571 		tv->vval.v_dict->dv_copyID = copyID;
4572 		*tofree = dict2string(tv, copyID, restore_copyID);
4573 		if (restore_copyID)
4574 		    tv->vval.v_dict->dv_copyID = old_copyID;
4575 		r = *tofree;
4576 	    }
4577 	    break;
4578 
4579 	case VAR_NUMBER:
4580 	case VAR_UNKNOWN:
4581 	case VAR_ANY:
4582 	case VAR_VOID:
4583 	    *tofree = NULL;
4584 	    r = tv_get_string_buf(tv, numbuf);
4585 	    break;
4586 
4587 	case VAR_JOB:
4588 	case VAR_CHANNEL:
4589 	    *tofree = NULL;
4590 	    r = tv_get_string_buf(tv, numbuf);
4591 	    if (composite_val)
4592 	    {
4593 		*tofree = string_quote(r, FALSE);
4594 		r = *tofree;
4595 	    }
4596 	    break;
4597 
4598 	case VAR_FLOAT:
4599 #ifdef FEAT_FLOAT
4600 	    *tofree = NULL;
4601 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
4602 	    r = numbuf;
4603 	    break;
4604 #endif
4605 
4606 	case VAR_BOOL:
4607 	case VAR_SPECIAL:
4608 	    *tofree = NULL;
4609 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
4610 	    break;
4611     }
4612 
4613     if (--recurse == 0)
4614 	did_echo_string_emsg = FALSE;
4615     return r;
4616 }
4617 
4618 /*
4619  * Return a string with the string representation of a variable.
4620  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4621  * "numbuf" is used for a number.
4622  * Does not put quotes around strings, as ":echo" displays values.
4623  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4624  * May return NULL.
4625  */
4626     char_u *
4627 echo_string(
4628     typval_T	*tv,
4629     char_u	**tofree,
4630     char_u	*numbuf,
4631     int		copyID)
4632 {
4633     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
4634 }
4635 
4636 /*
4637  * Return a string with the string representation of a variable.
4638  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4639  * "numbuf" is used for a number.
4640  * Puts quotes around strings, so that they can be parsed back by eval().
4641  * May return NULL.
4642  */
4643     char_u *
4644 tv2string(
4645     typval_T	*tv,
4646     char_u	**tofree,
4647     char_u	*numbuf,
4648     int		copyID)
4649 {
4650     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
4651 }
4652 
4653 /*
4654  * Return string "str" in ' quotes, doubling ' characters.
4655  * If "str" is NULL an empty string is assumed.
4656  * If "function" is TRUE make it function('string').
4657  */
4658     char_u *
4659 string_quote(char_u *str, int function)
4660 {
4661     unsigned	len;
4662     char_u	*p, *r, *s;
4663 
4664     len = (function ? 13 : 3);
4665     if (str != NULL)
4666     {
4667 	len += (unsigned)STRLEN(str);
4668 	for (p = str; *p != NUL; MB_PTR_ADV(p))
4669 	    if (*p == '\'')
4670 		++len;
4671     }
4672     s = r = alloc(len);
4673     if (r != NULL)
4674     {
4675 	if (function)
4676 	{
4677 	    STRCPY(r, "function('");
4678 	    r += 10;
4679 	}
4680 	else
4681 	    *r++ = '\'';
4682 	if (str != NULL)
4683 	    for (p = str; *p != NUL; )
4684 	    {
4685 		if (*p == '\'')
4686 		    *r++ = '\'';
4687 		MB_COPY_CHAR(p, r);
4688 	    }
4689 	*r++ = '\'';
4690 	if (function)
4691 	    *r++ = ')';
4692 	*r++ = NUL;
4693     }
4694     return s;
4695 }
4696 
4697 #if defined(FEAT_FLOAT) || defined(PROTO)
4698 /*
4699  * Convert the string "text" to a floating point number.
4700  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
4701  * this always uses a decimal point.
4702  * Returns the length of the text that was consumed.
4703  */
4704     int
4705 string2float(
4706     char_u	*text,
4707     float_T	*value)	    // result stored here
4708 {
4709     char	*s = (char *)text;
4710     float_T	f;
4711 
4712     // MS-Windows does not deal with "inf" and "nan" properly.
4713     if (STRNICMP(text, "inf", 3) == 0)
4714     {
4715 	*value = INFINITY;
4716 	return 3;
4717     }
4718     if (STRNICMP(text, "-inf", 3) == 0)
4719     {
4720 	*value = -INFINITY;
4721 	return 4;
4722     }
4723     if (STRNICMP(text, "nan", 3) == 0)
4724     {
4725 	*value = NAN;
4726 	return 3;
4727     }
4728     f = strtod(s, &s);
4729     *value = f;
4730     return (int)((char_u *)s - text);
4731 }
4732 #endif
4733 
4734 /*
4735  * Get the value of an environment variable.
4736  * "arg" is pointing to the '$'.  It is advanced to after the name.
4737  * If the environment variable was not set, silently assume it is empty.
4738  * Return FAIL if the name is invalid.
4739  */
4740     int
4741 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
4742 {
4743     char_u	*string = NULL;
4744     int		len;
4745     int		cc;
4746     char_u	*name;
4747     int		mustfree = FALSE;
4748 
4749     ++*arg;
4750     name = *arg;
4751     len = get_env_len(arg);
4752     if (evaluate)
4753     {
4754 	if (len == 0)
4755 	    return FAIL; // invalid empty name
4756 
4757 	cc = name[len];
4758 	name[len] = NUL;
4759 	// first try vim_getenv(), fast for normal environment vars
4760 	string = vim_getenv(name, &mustfree);
4761 	if (string != NULL && *string != NUL)
4762 	{
4763 	    if (!mustfree)
4764 		string = vim_strsave(string);
4765 	}
4766 	else
4767 	{
4768 	    if (mustfree)
4769 		vim_free(string);
4770 
4771 	    // next try expanding things like $VIM and ${HOME}
4772 	    string = expand_env_save(name - 1);
4773 	    if (string != NULL && *string == '$')
4774 		VIM_CLEAR(string);
4775 	}
4776 	name[len] = cc;
4777 
4778 	rettv->v_type = VAR_STRING;
4779 	rettv->vval.v_string = string;
4780     }
4781 
4782     return OK;
4783 }
4784 
4785 /*
4786  * Translate a String variable into a position.
4787  * Returns NULL when there is an error.
4788  */
4789     pos_T *
4790 var2fpos(
4791     typval_T	*varp,
4792     int		dollar_lnum,	// TRUE when $ is last line
4793     int		*fnum)		// set to fnum for '0, 'A, etc.
4794 {
4795     char_u		*name;
4796     static pos_T	pos;
4797     pos_T		*pp;
4798 
4799     // Argument can be [lnum, col, coladd].
4800     if (varp->v_type == VAR_LIST)
4801     {
4802 	list_T		*l;
4803 	int		len;
4804 	int		error = FALSE;
4805 	listitem_T	*li;
4806 
4807 	l = varp->vval.v_list;
4808 	if (l == NULL)
4809 	    return NULL;
4810 
4811 	// Get the line number
4812 	pos.lnum = list_find_nr(l, 0L, &error);
4813 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
4814 	    return NULL;	// invalid line number
4815 
4816 	// Get the column number
4817 	pos.col = list_find_nr(l, 1L, &error);
4818 	if (error)
4819 	    return NULL;
4820 	len = (long)STRLEN(ml_get(pos.lnum));
4821 
4822 	// We accept "$" for the column number: last column.
4823 	li = list_find(l, 1L);
4824 	if (li != NULL && li->li_tv.v_type == VAR_STRING
4825 		&& li->li_tv.vval.v_string != NULL
4826 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
4827 	    pos.col = len + 1;
4828 
4829 	// Accept a position up to the NUL after the line.
4830 	if (pos.col == 0 || (int)pos.col > len + 1)
4831 	    return NULL;	// invalid column number
4832 	--pos.col;
4833 
4834 	// Get the virtual offset.  Defaults to zero.
4835 	pos.coladd = list_find_nr(l, 2L, &error);
4836 	if (error)
4837 	    pos.coladd = 0;
4838 
4839 	return &pos;
4840     }
4841 
4842     name = tv_get_string_chk(varp);
4843     if (name == NULL)
4844 	return NULL;
4845     if (name[0] == '.')				// cursor
4846 	return &curwin->w_cursor;
4847     if (name[0] == 'v' && name[1] == NUL)	// Visual start
4848     {
4849 	if (VIsual_active)
4850 	    return &VIsual;
4851 	return &curwin->w_cursor;
4852     }
4853     if (name[0] == '\'')			// mark
4854     {
4855 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
4856 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
4857 	    return NULL;
4858 	return pp;
4859     }
4860 
4861     pos.coladd = 0;
4862 
4863     if (name[0] == 'w' && dollar_lnum)
4864     {
4865 	pos.col = 0;
4866 	if (name[1] == '0')		// "w0": first visible line
4867 	{
4868 	    update_topline();
4869 	    // In silent Ex mode topline is zero, but that's not a valid line
4870 	    // number; use one instead.
4871 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
4872 	    return &pos;
4873 	}
4874 	else if (name[1] == '$')	// "w$": last visible line
4875 	{
4876 	    validate_botline();
4877 	    // In silent Ex mode botline is zero, return zero then.
4878 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
4879 	    return &pos;
4880 	}
4881     }
4882     else if (name[0] == '$')		// last column or line
4883     {
4884 	if (dollar_lnum)
4885 	{
4886 	    pos.lnum = curbuf->b_ml.ml_line_count;
4887 	    pos.col = 0;
4888 	}
4889 	else
4890 	{
4891 	    pos.lnum = curwin->w_cursor.lnum;
4892 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
4893 	}
4894 	return &pos;
4895     }
4896     return NULL;
4897 }
4898 
4899 /*
4900  * Convert list in "arg" into a position and optional file number.
4901  * When "fnump" is NULL there is no file number, only 3 items.
4902  * Note that the column is passed on as-is, the caller may want to decrement
4903  * it to use 1 for the first column.
4904  * Return FAIL when conversion is not possible, doesn't check the position for
4905  * validity.
4906  */
4907     int
4908 list2fpos(
4909     typval_T	*arg,
4910     pos_T	*posp,
4911     int		*fnump,
4912     colnr_T	*curswantp)
4913 {
4914     list_T	*l = arg->vval.v_list;
4915     long	i = 0;
4916     long	n;
4917 
4918     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
4919     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
4920     if (arg->v_type != VAR_LIST
4921 	    || l == NULL
4922 	    || l->lv_len < (fnump == NULL ? 2 : 3)
4923 	    || l->lv_len > (fnump == NULL ? 4 : 5))
4924 	return FAIL;
4925 
4926     if (fnump != NULL)
4927     {
4928 	n = list_find_nr(l, i++, NULL);	// fnum
4929 	if (n < 0)
4930 	    return FAIL;
4931 	if (n == 0)
4932 	    n = curbuf->b_fnum;		// current buffer
4933 	*fnump = n;
4934     }
4935 
4936     n = list_find_nr(l, i++, NULL);	// lnum
4937     if (n < 0)
4938 	return FAIL;
4939     posp->lnum = n;
4940 
4941     n = list_find_nr(l, i++, NULL);	// col
4942     if (n < 0)
4943 	return FAIL;
4944     posp->col = n;
4945 
4946     n = list_find_nr(l, i, NULL);	// off
4947     if (n < 0)
4948 	posp->coladd = 0;
4949     else
4950 	posp->coladd = n;
4951 
4952     if (curswantp != NULL)
4953 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
4954 
4955     return OK;
4956 }
4957 
4958 /*
4959  * Get the length of an environment variable name.
4960  * Advance "arg" to the first character after the name.
4961  * Return 0 for error.
4962  */
4963     int
4964 get_env_len(char_u **arg)
4965 {
4966     char_u	*p;
4967     int		len;
4968 
4969     for (p = *arg; vim_isIDc(*p); ++p)
4970 	;
4971     if (p == *arg)	    // no name found
4972 	return 0;
4973 
4974     len = (int)(p - *arg);
4975     *arg = p;
4976     return len;
4977 }
4978 
4979 /*
4980  * Get the length of the name of a function or internal variable.
4981  * "arg" is advanced to the first non-white character after the name.
4982  * Return 0 if something is wrong.
4983  */
4984     int
4985 get_id_len(char_u **arg)
4986 {
4987     char_u	*p;
4988     int		len;
4989 
4990     // Find the end of the name.
4991     for (p = *arg; eval_isnamec(*p); ++p)
4992     {
4993 	if (*p == ':')
4994 	{
4995 	    // "s:" is start of "s:var", but "n:" is not and can be used in
4996 	    // slice "[n:]".  Also "xx:" is not a namespace.
4997 	    len = (int)(p - *arg);
4998 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
4999 		    || len > 1)
5000 		break;
5001 	}
5002     }
5003     if (p == *arg)	    // no name found
5004 	return 0;
5005 
5006     len = (int)(p - *arg);
5007     *arg = skipwhite(p);
5008 
5009     return len;
5010 }
5011 
5012 /*
5013  * Get the length of the name of a variable or function.
5014  * Only the name is recognized, does not handle ".key" or "[idx]".
5015  * "arg" is advanced to the first non-white character after the name.
5016  * Return -1 if curly braces expansion failed.
5017  * Return 0 if something else is wrong.
5018  * If the name contains 'magic' {}'s, expand them and return the
5019  * expanded name in an allocated string via 'alias' - caller must free.
5020  */
5021     int
5022 get_name_len(
5023     char_u	**arg,
5024     char_u	**alias,
5025     int		evaluate,
5026     int		verbose)
5027 {
5028     int		len;
5029     char_u	*p;
5030     char_u	*expr_start;
5031     char_u	*expr_end;
5032 
5033     *alias = NULL;  // default to no alias
5034 
5035     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
5036 						  && (*arg)[2] == (int)KE_SNR)
5037     {
5038 	// hard coded <SNR>, already translated
5039 	*arg += 3;
5040 	return get_id_len(arg) + 3;
5041     }
5042     len = eval_fname_script(*arg);
5043     if (len > 0)
5044     {
5045 	// literal "<SID>", "s:" or "<SNR>"
5046 	*arg += len;
5047     }
5048 
5049     /*
5050      * Find the end of the name; check for {} construction.
5051      */
5052     p = find_name_end(*arg, &expr_start, &expr_end,
5053 					       len > 0 ? 0 : FNE_CHECK_START);
5054     if (expr_start != NULL)
5055     {
5056 	char_u	*temp_string;
5057 
5058 	if (!evaluate)
5059 	{
5060 	    len += (int)(p - *arg);
5061 	    *arg = skipwhite(p);
5062 	    return len;
5063 	}
5064 
5065 	/*
5066 	 * Include any <SID> etc in the expanded string:
5067 	 * Thus the -len here.
5068 	 */
5069 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
5070 	if (temp_string == NULL)
5071 	    return -1;
5072 	*alias = temp_string;
5073 	*arg = skipwhite(p);
5074 	return (int)STRLEN(temp_string);
5075     }
5076 
5077     len += get_id_len(arg);
5078     // Only give an error when there is something, otherwise it will be
5079     // reported at a higher level.
5080     if (len == 0 && verbose && **arg != NUL)
5081 	semsg(_(e_invexpr2), *arg);
5082 
5083     return len;
5084 }
5085 
5086 /*
5087  * Find the end of a variable or function name, taking care of magic braces.
5088  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
5089  * start and end of the first magic braces item.
5090  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
5091  * Return a pointer to just after the name.  Equal to "arg" if there is no
5092  * valid name.
5093  */
5094     char_u *
5095 find_name_end(
5096     char_u	*arg,
5097     char_u	**expr_start,
5098     char_u	**expr_end,
5099     int		flags)
5100 {
5101     int		mb_nest = 0;
5102     int		br_nest = 0;
5103     char_u	*p;
5104     int		len;
5105     int		vim9script = current_sctx.sc_version == SCRIPT_VERSION_VIM9;
5106 
5107     if (expr_start != NULL)
5108     {
5109 	*expr_start = NULL;
5110 	*expr_end = NULL;
5111     }
5112 
5113     // Quick check for valid starting character.
5114     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg)
5115 						&& (*arg != '{' || vim9script))
5116 	return arg;
5117 
5118     for (p = arg; *p != NUL
5119 		    && (eval_isnamec(*p)
5120 			|| (*p == '{' && !vim9script)
5121 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
5122 			|| mb_nest != 0
5123 			|| br_nest != 0); MB_PTR_ADV(p))
5124     {
5125 	if (*p == '\'')
5126 	{
5127 	    // skip over 'string' to avoid counting [ and ] inside it.
5128 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5129 		;
5130 	    if (*p == NUL)
5131 		break;
5132 	}
5133 	else if (*p == '"')
5134 	{
5135 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
5136 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5137 		if (*p == '\\' && p[1] != NUL)
5138 		    ++p;
5139 	    if (*p == NUL)
5140 		break;
5141 	}
5142 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5143 	{
5144 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5145 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
5146 	    len = (int)(p - arg);
5147 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5148 		    || (len > 1 && p[-1] != '}'))
5149 		break;
5150 	}
5151 
5152 	if (mb_nest == 0)
5153 	{
5154 	    if (*p == '[')
5155 		++br_nest;
5156 	    else if (*p == ']')
5157 		--br_nest;
5158 	}
5159 
5160 	if (br_nest == 0 && !vim9script)
5161 	{
5162 	    if (*p == '{')
5163 	    {
5164 		mb_nest++;
5165 		if (expr_start != NULL && *expr_start == NULL)
5166 		    *expr_start = p;
5167 	    }
5168 	    else if (*p == '}')
5169 	    {
5170 		mb_nest--;
5171 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5172 		    *expr_end = p;
5173 	    }
5174 	}
5175     }
5176 
5177     return p;
5178 }
5179 
5180 /*
5181  * Expands out the 'magic' {}'s in a variable/function name.
5182  * Note that this can call itself recursively, to deal with
5183  * constructs like foo{bar}{baz}{bam}
5184  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5185  *			"in_start"      ^
5186  *			"expr_start"	   ^
5187  *			"expr_end"		 ^
5188  *			"in_end"			    ^
5189  *
5190  * Returns a new allocated string, which the caller must free.
5191  * Returns NULL for failure.
5192  */
5193     static char_u *
5194 make_expanded_name(
5195     char_u	*in_start,
5196     char_u	*expr_start,
5197     char_u	*expr_end,
5198     char_u	*in_end)
5199 {
5200     char_u	c1;
5201     char_u	*retval = NULL;
5202     char_u	*temp_result;
5203     char_u	*nextcmd = NULL;
5204 
5205     if (expr_end == NULL || in_end == NULL)
5206 	return NULL;
5207     *expr_start	= NUL;
5208     *expr_end = NUL;
5209     c1 = *in_end;
5210     *in_end = NUL;
5211 
5212     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
5213     if (temp_result != NULL && nextcmd == NULL)
5214     {
5215 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5216 						   + (in_end - expr_end) + 1);
5217 	if (retval != NULL)
5218 	{
5219 	    STRCPY(retval, in_start);
5220 	    STRCAT(retval, temp_result);
5221 	    STRCAT(retval, expr_end + 1);
5222 	}
5223     }
5224     vim_free(temp_result);
5225 
5226     *in_end = c1;		// put char back for error messages
5227     *expr_start = '{';
5228     *expr_end = '}';
5229 
5230     if (retval != NULL)
5231     {
5232 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5233 	if (expr_start != NULL)
5234 	{
5235 	    // Further expansion!
5236 	    temp_result = make_expanded_name(retval, expr_start,
5237 						       expr_end, temp_result);
5238 	    vim_free(retval);
5239 	    retval = temp_result;
5240 	}
5241     }
5242 
5243     return retval;
5244 }
5245 
5246 /*
5247  * Return TRUE if character "c" can be used in a variable or function name.
5248  * Does not include '{' or '}' for magic braces.
5249  */
5250     int
5251 eval_isnamec(int c)
5252 {
5253     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
5254 }
5255 
5256 /*
5257  * Return TRUE if character "c" can be used as the first character in a
5258  * variable or function name (excluding '{' and '}').
5259  */
5260     int
5261 eval_isnamec1(int c)
5262 {
5263     return (ASCII_ISALPHA(c) || c == '_');
5264 }
5265 
5266 /*
5267  * Handle:
5268  * - expr[expr], expr[expr:expr] subscript
5269  * - ".name" lookup
5270  * - function call with Funcref variable: func(expr)
5271  * - method call: var->method()
5272  *
5273  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5274  */
5275     int
5276 handle_subscript(
5277     char_u	**arg,
5278     typval_T	*rettv,
5279     int		evaluate,	// do more than finding the end
5280     int		verbose,	// give error messages
5281     char_u	*start_leader,	// start of '!' and '-' prefixes
5282     char_u	**end_leaderp)  // end of '!' and '-' prefixes
5283 {
5284     int		ret = OK;
5285     dict_T	*selfdict = NULL;
5286 
5287     // "." is ".name" lookup when we found a dict or when evaluating and
5288     // scriptversion is at least 2, where string concatenation is "..".
5289     while (ret == OK
5290 	    && (((**arg == '['
5291 		    || (**arg == '.' && (rettv->v_type == VAR_DICT
5292 			|| (!evaluate
5293 			    && (*arg)[1] != '.'
5294 			    && current_sctx.sc_version >= 2)))
5295 		    || (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5296 					    || rettv->v_type == VAR_PARTIAL)))
5297 		&& !VIM_ISWHITE(*(*arg - 1)))
5298 	    || (**arg == '-' && (*arg)[1] == '>')))
5299     {
5300 	if (**arg == '(')
5301 	{
5302 	    ret = call_func_rettv(arg, rettv, evaluate, selfdict, NULL);
5303 
5304 	    // Stop the expression evaluation when immediately aborting on
5305 	    // error, or when an interrupt occurred or an exception was thrown
5306 	    // but not caught.
5307 	    if (aborting())
5308 	    {
5309 		if (ret == OK)
5310 		    clear_tv(rettv);
5311 		ret = FAIL;
5312 	    }
5313 	    dict_unref(selfdict);
5314 	    selfdict = NULL;
5315 	}
5316 	else if (**arg == '-')
5317 	{
5318 	    // Expression "-1.0->method()" applies the leader "-" before
5319 	    // applying ->.
5320 	    if (evaluate && *end_leaderp > start_leader)
5321 		ret = eval7_leader(rettv, start_leader, end_leaderp);
5322 	    if (ret == OK)
5323 	    {
5324 		if ((*arg)[2] == '{')
5325 		    // expr->{lambda}()
5326 		    ret = eval_lambda(arg, rettv, evaluate, verbose);
5327 		else
5328 		    // expr->name()
5329 		    ret = eval_method(arg, rettv, evaluate, verbose);
5330 	    }
5331 	}
5332 	else // **arg == '[' || **arg == '.'
5333 	{
5334 	    dict_unref(selfdict);
5335 	    if (rettv->v_type == VAR_DICT)
5336 	    {
5337 		selfdict = rettv->vval.v_dict;
5338 		if (selfdict != NULL)
5339 		    ++selfdict->dv_refcount;
5340 	    }
5341 	    else
5342 		selfdict = NULL;
5343 	    if (eval_index(arg, rettv, evaluate, verbose) == FAIL)
5344 	    {
5345 		clear_tv(rettv);
5346 		ret = FAIL;
5347 	    }
5348 	}
5349     }
5350 
5351     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5352     // Don't do this when "Func" is already a partial that was bound
5353     // explicitly (pt_auto is FALSE).
5354     if (selfdict != NULL
5355 	    && (rettv->v_type == VAR_FUNC
5356 		|| (rettv->v_type == VAR_PARTIAL
5357 		    && (rettv->vval.v_partial->pt_auto
5358 			|| rettv->vval.v_partial->pt_dict == NULL))))
5359 	selfdict = make_partial(selfdict, rettv);
5360 
5361     dict_unref(selfdict);
5362     return ret;
5363 }
5364 
5365 /*
5366  * Allocate memory for a variable type-value, and make it empty (0 or NULL
5367  * value).
5368  */
5369     typval_T *
5370 alloc_tv(void)
5371 {
5372     return ALLOC_CLEAR_ONE(typval_T);
5373 }
5374 
5375 /*
5376  * Allocate memory for a variable type-value, and assign a string to it.
5377  * The string "s" must have been allocated, it is consumed.
5378  * Return NULL for out of memory, the variable otherwise.
5379  */
5380     typval_T *
5381 alloc_string_tv(char_u *s)
5382 {
5383     typval_T	*rettv;
5384 
5385     rettv = alloc_tv();
5386     if (rettv != NULL)
5387     {
5388 	rettv->v_type = VAR_STRING;
5389 	rettv->vval.v_string = s;
5390     }
5391     else
5392 	vim_free(s);
5393     return rettv;
5394 }
5395 
5396 /*
5397  * Free the memory for a variable type-value.
5398  */
5399     void
5400 free_tv(typval_T *varp)
5401 {
5402     if (varp != NULL)
5403     {
5404 	switch (varp->v_type)
5405 	{
5406 	    case VAR_FUNC:
5407 		func_unref(varp->vval.v_string);
5408 		// FALLTHROUGH
5409 	    case VAR_STRING:
5410 		vim_free(varp->vval.v_string);
5411 		break;
5412 	    case VAR_PARTIAL:
5413 		partial_unref(varp->vval.v_partial);
5414 		break;
5415 	    case VAR_BLOB:
5416 		blob_unref(varp->vval.v_blob);
5417 		break;
5418 	    case VAR_LIST:
5419 		list_unref(varp->vval.v_list);
5420 		break;
5421 	    case VAR_DICT:
5422 		dict_unref(varp->vval.v_dict);
5423 		break;
5424 	    case VAR_JOB:
5425 #ifdef FEAT_JOB_CHANNEL
5426 		job_unref(varp->vval.v_job);
5427 		break;
5428 #endif
5429 	    case VAR_CHANNEL:
5430 #ifdef FEAT_JOB_CHANNEL
5431 		channel_unref(varp->vval.v_channel);
5432 		break;
5433 #endif
5434 	    case VAR_NUMBER:
5435 	    case VAR_FLOAT:
5436 	    case VAR_ANY:
5437 	    case VAR_UNKNOWN:
5438 	    case VAR_VOID:
5439 	    case VAR_BOOL:
5440 	    case VAR_SPECIAL:
5441 		break;
5442 	}
5443 	vim_free(varp);
5444     }
5445 }
5446 
5447 /*
5448  * Free the memory for a variable value and set the value to NULL or 0.
5449  */
5450     void
5451 clear_tv(typval_T *varp)
5452 {
5453     if (varp != NULL)
5454     {
5455 	switch (varp->v_type)
5456 	{
5457 	    case VAR_FUNC:
5458 		func_unref(varp->vval.v_string);
5459 		// FALLTHROUGH
5460 	    case VAR_STRING:
5461 		VIM_CLEAR(varp->vval.v_string);
5462 		break;
5463 	    case VAR_PARTIAL:
5464 		partial_unref(varp->vval.v_partial);
5465 		varp->vval.v_partial = NULL;
5466 		break;
5467 	    case VAR_BLOB:
5468 		blob_unref(varp->vval.v_blob);
5469 		varp->vval.v_blob = NULL;
5470 		break;
5471 	    case VAR_LIST:
5472 		list_unref(varp->vval.v_list);
5473 		varp->vval.v_list = NULL;
5474 		break;
5475 	    case VAR_DICT:
5476 		dict_unref(varp->vval.v_dict);
5477 		varp->vval.v_dict = NULL;
5478 		break;
5479 	    case VAR_NUMBER:
5480 	    case VAR_BOOL:
5481 	    case VAR_SPECIAL:
5482 		varp->vval.v_number = 0;
5483 		break;
5484 	    case VAR_FLOAT:
5485 #ifdef FEAT_FLOAT
5486 		varp->vval.v_float = 0.0;
5487 		break;
5488 #endif
5489 	    case VAR_JOB:
5490 #ifdef FEAT_JOB_CHANNEL
5491 		job_unref(varp->vval.v_job);
5492 		varp->vval.v_job = NULL;
5493 #endif
5494 		break;
5495 	    case VAR_CHANNEL:
5496 #ifdef FEAT_JOB_CHANNEL
5497 		channel_unref(varp->vval.v_channel);
5498 		varp->vval.v_channel = NULL;
5499 #endif
5500 	    case VAR_UNKNOWN:
5501 	    case VAR_ANY:
5502 	    case VAR_VOID:
5503 		break;
5504 	}
5505 	varp->v_lock = 0;
5506     }
5507 }
5508 
5509 /*
5510  * Set the value of a variable to NULL without freeing items.
5511  */
5512     void
5513 init_tv(typval_T *varp)
5514 {
5515     if (varp != NULL)
5516 	CLEAR_POINTER(varp);
5517 }
5518 
5519 /*
5520  * Get the number value of a variable.
5521  * If it is a String variable, uses vim_str2nr().
5522  * For incompatible types, return 0.
5523  * tv_get_number_chk() is similar to tv_get_number(), but informs the
5524  * caller of incompatible types: it sets *denote to TRUE if "denote"
5525  * is not NULL or returns -1 otherwise.
5526  */
5527     varnumber_T
5528 tv_get_number(typval_T *varp)
5529 {
5530     int		error = FALSE;
5531 
5532     return tv_get_number_chk(varp, &error);	// return 0L on error
5533 }
5534 
5535     varnumber_T
5536 tv_get_number_chk(typval_T *varp, int *denote)
5537 {
5538     varnumber_T	n = 0L;
5539 
5540     switch (varp->v_type)
5541     {
5542 	case VAR_NUMBER:
5543 	    return varp->vval.v_number;
5544 	case VAR_FLOAT:
5545 #ifdef FEAT_FLOAT
5546 	    emsg(_("E805: Using a Float as a Number"));
5547 	    break;
5548 #endif
5549 	case VAR_FUNC:
5550 	case VAR_PARTIAL:
5551 	    emsg(_("E703: Using a Funcref as a Number"));
5552 	    break;
5553 	case VAR_STRING:
5554 	    if (varp->vval.v_string != NULL)
5555 		vim_str2nr(varp->vval.v_string, NULL, NULL,
5556 					    STR2NR_ALL, &n, NULL, 0, FALSE);
5557 	    return n;
5558 	case VAR_LIST:
5559 	    emsg(_("E745: Using a List as a Number"));
5560 	    break;
5561 	case VAR_DICT:
5562 	    emsg(_("E728: Using a Dictionary as a Number"));
5563 	    break;
5564 	case VAR_BOOL:
5565 	case VAR_SPECIAL:
5566 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
5567 	case VAR_JOB:
5568 #ifdef FEAT_JOB_CHANNEL
5569 	    emsg(_("E910: Using a Job as a Number"));
5570 	    break;
5571 #endif
5572 	case VAR_CHANNEL:
5573 #ifdef FEAT_JOB_CHANNEL
5574 	    emsg(_("E913: Using a Channel as a Number"));
5575 	    break;
5576 #endif
5577 	case VAR_BLOB:
5578 	    emsg(_("E974: Using a Blob as a Number"));
5579 	    break;
5580 	case VAR_UNKNOWN:
5581 	case VAR_ANY:
5582 	case VAR_VOID:
5583 	    internal_error_no_abort("tv_get_number(UNKNOWN)");
5584 	    break;
5585     }
5586     if (denote == NULL)		// useful for values that must be unsigned
5587 	n = -1;
5588     else
5589 	*denote = TRUE;
5590     return n;
5591 }
5592 
5593 #ifdef FEAT_FLOAT
5594     float_T
5595 tv_get_float(typval_T *varp)
5596 {
5597     switch (varp->v_type)
5598     {
5599 	case VAR_NUMBER:
5600 	    return (float_T)(varp->vval.v_number);
5601 	case VAR_FLOAT:
5602 	    return varp->vval.v_float;
5603 	case VAR_FUNC:
5604 	case VAR_PARTIAL:
5605 	    emsg(_("E891: Using a Funcref as a Float"));
5606 	    break;
5607 	case VAR_STRING:
5608 	    emsg(_("E892: Using a String as a Float"));
5609 	    break;
5610 	case VAR_LIST:
5611 	    emsg(_("E893: Using a List as a Float"));
5612 	    break;
5613 	case VAR_DICT:
5614 	    emsg(_("E894: Using a Dictionary as a Float"));
5615 	    break;
5616 	case VAR_BOOL:
5617 	    emsg(_("E362: Using a boolean value as a Float"));
5618 	    break;
5619 	case VAR_SPECIAL:
5620 	    emsg(_("E907: Using a special value as a Float"));
5621 	    break;
5622 	case VAR_JOB:
5623 # ifdef FEAT_JOB_CHANNEL
5624 	    emsg(_("E911: Using a Job as a Float"));
5625 	    break;
5626 # endif
5627 	case VAR_CHANNEL:
5628 # ifdef FEAT_JOB_CHANNEL
5629 	    emsg(_("E914: Using a Channel as a Float"));
5630 	    break;
5631 # endif
5632 	case VAR_BLOB:
5633 	    emsg(_("E975: Using a Blob as a Float"));
5634 	    break;
5635 	case VAR_UNKNOWN:
5636 	case VAR_ANY:
5637 	case VAR_VOID:
5638 	    internal_error_no_abort("tv_get_float(UNKNOWN)");
5639 	    break;
5640     }
5641     return 0;
5642 }
5643 #endif
5644 
5645 /*
5646  * Get the string value of a variable.
5647  * If it is a Number variable, the number is converted into a string.
5648  * tv_get_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
5649  * tv_get_string_buf() uses a given buffer.
5650  * If the String variable has never been set, return an empty string.
5651  * Never returns NULL;
5652  * tv_get_string_chk() and tv_get_string_buf_chk() are similar, but return
5653  * NULL on error.
5654  */
5655     char_u *
5656 tv_get_string(typval_T *varp)
5657 {
5658     static char_u   mybuf[NUMBUFLEN];
5659 
5660     return tv_get_string_buf(varp, mybuf);
5661 }
5662 
5663     char_u *
5664 tv_get_string_buf(typval_T *varp, char_u *buf)
5665 {
5666     char_u	*res =  tv_get_string_buf_chk(varp, buf);
5667 
5668     return res != NULL ? res : (char_u *)"";
5669 }
5670 
5671 /*
5672  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
5673  */
5674     char_u *
5675 tv_get_string_chk(typval_T *varp)
5676 {
5677     static char_u   mybuf[NUMBUFLEN];
5678 
5679     return tv_get_string_buf_chk(varp, mybuf);
5680 }
5681 
5682     char_u *
5683 tv_get_string_buf_chk(typval_T *varp, char_u *buf)
5684 {
5685     switch (varp->v_type)
5686     {
5687 	case VAR_NUMBER:
5688 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
5689 					    (varnumber_T)varp->vval.v_number);
5690 	    return buf;
5691 	case VAR_FUNC:
5692 	case VAR_PARTIAL:
5693 	    emsg(_("E729: using Funcref as a String"));
5694 	    break;
5695 	case VAR_LIST:
5696 	    emsg(_("E730: using List as a String"));
5697 	    break;
5698 	case VAR_DICT:
5699 	    emsg(_("E731: using Dictionary as a String"));
5700 	    break;
5701 	case VAR_FLOAT:
5702 #ifdef FEAT_FLOAT
5703 	    emsg(_(e_float_as_string));
5704 	    break;
5705 #endif
5706 	case VAR_STRING:
5707 	    if (varp->vval.v_string != NULL)
5708 		return varp->vval.v_string;
5709 	    return (char_u *)"";
5710 	case VAR_BOOL:
5711 	case VAR_SPECIAL:
5712 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
5713 	    return buf;
5714         case VAR_BLOB:
5715 	    emsg(_("E976: using Blob as a String"));
5716 	    break;
5717 	case VAR_JOB:
5718 #ifdef FEAT_JOB_CHANNEL
5719 	    {
5720 		job_T *job = varp->vval.v_job;
5721 		char  *status;
5722 
5723 		if (job == NULL)
5724 		    return (char_u *)"no process";
5725 		status = job->jv_status == JOB_FAILED ? "fail"
5726 				: job->jv_status >= JOB_ENDED ? "dead"
5727 				: "run";
5728 # ifdef UNIX
5729 		vim_snprintf((char *)buf, NUMBUFLEN,
5730 			    "process %ld %s", (long)job->jv_pid, status);
5731 # elif defined(MSWIN)
5732 		vim_snprintf((char *)buf, NUMBUFLEN,
5733 			    "process %ld %s",
5734 			    (long)job->jv_proc_info.dwProcessId,
5735 			    status);
5736 # else
5737 		// fall-back
5738 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
5739 # endif
5740 		return buf;
5741 	    }
5742 #endif
5743 	    break;
5744 	case VAR_CHANNEL:
5745 #ifdef FEAT_JOB_CHANNEL
5746 	    {
5747 		channel_T *channel = varp->vval.v_channel;
5748 		char      *status = channel_status(channel, -1);
5749 
5750 		if (channel == NULL)
5751 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
5752 		else
5753 		    vim_snprintf((char *)buf, NUMBUFLEN,
5754 				     "channel %d %s", channel->ch_id, status);
5755 		return buf;
5756 	    }
5757 #endif
5758 	    break;
5759 	case VAR_UNKNOWN:
5760 	case VAR_ANY:
5761 	case VAR_VOID:
5762 	    emsg(_(e_inval_string));
5763 	    break;
5764     }
5765     return NULL;
5766 }
5767 
5768 /*
5769  * Turn a typeval into a string.  Similar to tv_get_string_buf() but uses
5770  * string() on Dict, List, etc.
5771  */
5772     static char_u *
5773 tv_stringify(typval_T *varp, char_u *buf)
5774 {
5775     if (varp->v_type == VAR_LIST
5776 	    || varp->v_type == VAR_DICT
5777 	    || varp->v_type == VAR_BLOB
5778 	    || varp->v_type == VAR_FUNC
5779 	    || varp->v_type == VAR_PARTIAL
5780 	    || varp->v_type == VAR_FLOAT)
5781     {
5782 	typval_T tmp;
5783 
5784 	f_string(varp, &tmp);
5785 	tv_get_string_buf(&tmp, buf);
5786 	clear_tv(varp);
5787 	*varp = tmp;
5788 	return tmp.vval.v_string;
5789     }
5790     return tv_get_string_buf(varp, buf);
5791 }
5792 
5793 /*
5794  * Return TRUE if typeval "tv" and its value are set to be locked (immutable).
5795  * Also give an error message, using "name" or _("name") when use_gettext is
5796  * TRUE.
5797  */
5798     static int
5799 tv_check_lock(typval_T *tv, char_u *name, int use_gettext)
5800 {
5801     int	lock = 0;
5802 
5803     switch (tv->v_type)
5804     {
5805 	case VAR_BLOB:
5806 	    if (tv->vval.v_blob != NULL)
5807 		lock = tv->vval.v_blob->bv_lock;
5808 	    break;
5809 	case VAR_LIST:
5810 	    if (tv->vval.v_list != NULL)
5811 		lock = tv->vval.v_list->lv_lock;
5812 	    break;
5813 	case VAR_DICT:
5814 	    if (tv->vval.v_dict != NULL)
5815 		lock = tv->vval.v_dict->dv_lock;
5816 	    break;
5817 	default:
5818 	    break;
5819     }
5820     return var_check_lock(tv->v_lock, name, use_gettext)
5821 		    || (lock != 0 && var_check_lock(lock, name, use_gettext));
5822 }
5823 
5824 /*
5825  * Copy the values from typval_T "from" to typval_T "to".
5826  * When needed allocates string or increases reference count.
5827  * Does not make a copy of a list, blob or dict but copies the reference!
5828  * It is OK for "from" and "to" to point to the same item.  This is used to
5829  * make a copy later.
5830  */
5831     void
5832 copy_tv(typval_T *from, typval_T *to)
5833 {
5834     to->v_type = from->v_type;
5835     to->v_lock = 0;
5836     switch (from->v_type)
5837     {
5838 	case VAR_NUMBER:
5839 	case VAR_BOOL:
5840 	case VAR_SPECIAL:
5841 	    to->vval.v_number = from->vval.v_number;
5842 	    break;
5843 	case VAR_FLOAT:
5844 #ifdef FEAT_FLOAT
5845 	    to->vval.v_float = from->vval.v_float;
5846 	    break;
5847 #endif
5848 	case VAR_JOB:
5849 #ifdef FEAT_JOB_CHANNEL
5850 	    to->vval.v_job = from->vval.v_job;
5851 	    if (to->vval.v_job != NULL)
5852 		++to->vval.v_job->jv_refcount;
5853 	    break;
5854 #endif
5855 	case VAR_CHANNEL:
5856 #ifdef FEAT_JOB_CHANNEL
5857 	    to->vval.v_channel = from->vval.v_channel;
5858 	    if (to->vval.v_channel != NULL)
5859 		++to->vval.v_channel->ch_refcount;
5860 	    break;
5861 #endif
5862 	case VAR_STRING:
5863 	case VAR_FUNC:
5864 	    if (from->vval.v_string == NULL)
5865 		to->vval.v_string = NULL;
5866 	    else
5867 	    {
5868 		to->vval.v_string = vim_strsave(from->vval.v_string);
5869 		if (from->v_type == VAR_FUNC)
5870 		    func_ref(to->vval.v_string);
5871 	    }
5872 	    break;
5873 	case VAR_PARTIAL:
5874 	    if (from->vval.v_partial == NULL)
5875 		to->vval.v_partial = NULL;
5876 	    else
5877 	    {
5878 		to->vval.v_partial = from->vval.v_partial;
5879 		++to->vval.v_partial->pt_refcount;
5880 	    }
5881 	    break;
5882 	case VAR_BLOB:
5883 	    if (from->vval.v_blob == NULL)
5884 		to->vval.v_blob = NULL;
5885 	    else
5886 	    {
5887 		to->vval.v_blob = from->vval.v_blob;
5888 		++to->vval.v_blob->bv_refcount;
5889 	    }
5890 	    break;
5891 	case VAR_LIST:
5892 	    if (from->vval.v_list == NULL)
5893 		to->vval.v_list = NULL;
5894 	    else
5895 	    {
5896 		to->vval.v_list = from->vval.v_list;
5897 		++to->vval.v_list->lv_refcount;
5898 	    }
5899 	    break;
5900 	case VAR_DICT:
5901 	    if (from->vval.v_dict == NULL)
5902 		to->vval.v_dict = NULL;
5903 	    else
5904 	    {
5905 		to->vval.v_dict = from->vval.v_dict;
5906 		++to->vval.v_dict->dv_refcount;
5907 	    }
5908 	    break;
5909 	case VAR_UNKNOWN:
5910 	case VAR_ANY:
5911 	case VAR_VOID:
5912 	    internal_error_no_abort("copy_tv(UNKNOWN)");
5913 	    break;
5914     }
5915 }
5916 
5917 /*
5918  * Make a copy of an item.
5919  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5920  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5921  * reference to an already copied list/dict can be used.
5922  * Returns FAIL or OK.
5923  */
5924     int
5925 item_copy(
5926     typval_T	*from,
5927     typval_T	*to,
5928     int		deep,
5929     int		copyID)
5930 {
5931     static int	recurse = 0;
5932     int		ret = OK;
5933 
5934     if (recurse >= DICT_MAXNEST)
5935     {
5936 	emsg(_("E698: variable nested too deep for making a copy"));
5937 	return FAIL;
5938     }
5939     ++recurse;
5940 
5941     switch (from->v_type)
5942     {
5943 	case VAR_NUMBER:
5944 	case VAR_FLOAT:
5945 	case VAR_STRING:
5946 	case VAR_FUNC:
5947 	case VAR_PARTIAL:
5948 	case VAR_BOOL:
5949 	case VAR_SPECIAL:
5950 	case VAR_JOB:
5951 	case VAR_CHANNEL:
5952 	    copy_tv(from, to);
5953 	    break;
5954 	case VAR_LIST:
5955 	    to->v_type = VAR_LIST;
5956 	    to->v_lock = 0;
5957 	    if (from->vval.v_list == NULL)
5958 		to->vval.v_list = NULL;
5959 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
5960 	    {
5961 		// use the copy made earlier
5962 		to->vval.v_list = from->vval.v_list->lv_copylist;
5963 		++to->vval.v_list->lv_refcount;
5964 	    }
5965 	    else
5966 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
5967 	    if (to->vval.v_list == NULL)
5968 		ret = FAIL;
5969 	    break;
5970 	case VAR_BLOB:
5971 	    ret = blob_copy(from->vval.v_blob, to);
5972 	    break;
5973 	case VAR_DICT:
5974 	    to->v_type = VAR_DICT;
5975 	    to->v_lock = 0;
5976 	    if (from->vval.v_dict == NULL)
5977 		to->vval.v_dict = NULL;
5978 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
5979 	    {
5980 		// use the copy made earlier
5981 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
5982 		++to->vval.v_dict->dv_refcount;
5983 	    }
5984 	    else
5985 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
5986 	    if (to->vval.v_dict == NULL)
5987 		ret = FAIL;
5988 	    break;
5989 	case VAR_UNKNOWN:
5990 	case VAR_ANY:
5991 	case VAR_VOID:
5992 	    internal_error_no_abort("item_copy(UNKNOWN)");
5993 	    ret = FAIL;
5994     }
5995     --recurse;
5996     return ret;
5997 }
5998 
5999     void
6000 echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr)
6001 {
6002     char_u	*tofree;
6003     char_u	numbuf[NUMBUFLEN];
6004     char_u	*p = echo_string(rettv, &tofree, numbuf, get_copyID());
6005 
6006     if (*atstart)
6007     {
6008 	*atstart = FALSE;
6009 	// Call msg_start() after eval1(), evaluating the expression
6010 	// may cause a message to appear.
6011 	if (with_space)
6012 	{
6013 	    // Mark the saved text as finishing the line, so that what
6014 	    // follows is displayed on a new line when scrolling back
6015 	    // at the more prompt.
6016 	    msg_sb_eol();
6017 	    msg_start();
6018 	}
6019     }
6020     else if (with_space)
6021 	msg_puts_attr(" ", echo_attr);
6022 
6023     if (p != NULL)
6024 	for ( ; *p != NUL && !got_int; ++p)
6025 	{
6026 	    if (*p == '\n' || *p == '\r' || *p == TAB)
6027 	    {
6028 		if (*p != TAB && *needclr)
6029 		{
6030 		    // remove any text still there from the command
6031 		    msg_clr_eos();
6032 		    *needclr = FALSE;
6033 		}
6034 		msg_putchar_attr(*p, echo_attr);
6035 	    }
6036 	    else
6037 	    {
6038 		if (has_mbyte)
6039 		{
6040 		    int i = (*mb_ptr2len)(p);
6041 
6042 		    (void)msg_outtrans_len_attr(p, i, echo_attr);
6043 		    p += i - 1;
6044 		}
6045 		else
6046 		    (void)msg_outtrans_len_attr(p, 1, echo_attr);
6047 	    }
6048 	}
6049     vim_free(tofree);
6050 }
6051 
6052 /*
6053  * ":echo expr1 ..."	print each argument separated with a space, add a
6054  *			newline at the end.
6055  * ":echon expr1 ..."	print each argument plain.
6056  */
6057     void
6058 ex_echo(exarg_T *eap)
6059 {
6060     char_u	*arg = eap->arg;
6061     typval_T	rettv;
6062     char_u	*p;
6063     int		needclr = TRUE;
6064     int		atstart = TRUE;
6065     int		did_emsg_before = did_emsg;
6066     int		called_emsg_before = called_emsg;
6067 
6068     if (eap->skip)
6069 	++emsg_skip;
6070     while ((!ends_excmd2(eap->cmd, arg) || *arg == '"') && !got_int)
6071     {
6072 	// If eval1() causes an error message the text from the command may
6073 	// still need to be cleared. E.g., "echo 22,44".
6074 	need_clr_eos = needclr;
6075 
6076 	p = arg;
6077 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
6078 	{
6079 	    /*
6080 	     * Report the invalid expression unless the expression evaluation
6081 	     * has been cancelled due to an aborting error, an interrupt, or an
6082 	     * exception.
6083 	     */
6084 	    if (!aborting() && did_emsg == did_emsg_before
6085 					  && called_emsg == called_emsg_before)
6086 		semsg(_(e_invexpr2), p);
6087 	    need_clr_eos = FALSE;
6088 	    break;
6089 	}
6090 	need_clr_eos = FALSE;
6091 
6092 	if (!eap->skip)
6093 	    echo_one(&rettv, eap->cmdidx == CMD_echo, &atstart, &needclr);
6094 
6095 	clear_tv(&rettv);
6096 	arg = skipwhite(arg);
6097     }
6098     eap->nextcmd = check_nextcmd(arg);
6099 
6100     if (eap->skip)
6101 	--emsg_skip;
6102     else
6103     {
6104 	// remove text that may still be there from the command
6105 	if (needclr)
6106 	    msg_clr_eos();
6107 	if (eap->cmdidx == CMD_echo)
6108 	    msg_end();
6109     }
6110 }
6111 
6112 /*
6113  * ":echohl {name}".
6114  */
6115     void
6116 ex_echohl(exarg_T *eap)
6117 {
6118     echo_attr = syn_name2attr(eap->arg);
6119 }
6120 
6121 /*
6122  * Returns the :echo attribute
6123  */
6124     int
6125 get_echo_attr(void)
6126 {
6127     return echo_attr;
6128 }
6129 
6130 /*
6131  * ":execute expr1 ..."	execute the result of an expression.
6132  * ":echomsg expr1 ..."	Print a message
6133  * ":echoerr expr1 ..."	Print an error
6134  * Each gets spaces around each argument and a newline at the end for
6135  * echo commands
6136  */
6137     void
6138 ex_execute(exarg_T *eap)
6139 {
6140     char_u	*arg = eap->arg;
6141     typval_T	rettv;
6142     int		ret = OK;
6143     char_u	*p;
6144     garray_T	ga;
6145     int		len;
6146 
6147     ga_init2(&ga, 1, 80);
6148 
6149     if (eap->skip)
6150 	++emsg_skip;
6151     while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
6152     {
6153 	ret = eval1_emsg(&arg, &rettv, !eap->skip);
6154 	if (ret == FAIL)
6155 	    break;
6156 
6157 	if (!eap->skip)
6158 	{
6159 	    char_u   buf[NUMBUFLEN];
6160 
6161 	    if (eap->cmdidx == CMD_execute)
6162 	    {
6163 		if (rettv.v_type == VAR_CHANNEL || rettv.v_type == VAR_JOB)
6164 		{
6165 		    emsg(_(e_inval_string));
6166 		    p = NULL;
6167 		}
6168 		else
6169 		    p = tv_get_string_buf(&rettv, buf);
6170 	    }
6171 	    else
6172 		p = tv_stringify(&rettv, buf);
6173 	    if (p == NULL)
6174 	    {
6175 		clear_tv(&rettv);
6176 		ret = FAIL;
6177 		break;
6178 	    }
6179 	    len = (int)STRLEN(p);
6180 	    if (ga_grow(&ga, len + 2) == FAIL)
6181 	    {
6182 		clear_tv(&rettv);
6183 		ret = FAIL;
6184 		break;
6185 	    }
6186 	    if (ga.ga_len)
6187 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
6188 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
6189 	    ga.ga_len += len;
6190 	}
6191 
6192 	clear_tv(&rettv);
6193 	arg = skipwhite(arg);
6194     }
6195 
6196     if (ret != FAIL && ga.ga_data != NULL)
6197     {
6198 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
6199 	{
6200 	    // Mark the already saved text as finishing the line, so that what
6201 	    // follows is displayed on a new line when scrolling back at the
6202 	    // more prompt.
6203 	    msg_sb_eol();
6204 	}
6205 
6206 	if (eap->cmdidx == CMD_echomsg)
6207 	{
6208 	    msg_attr(ga.ga_data, echo_attr);
6209 	    out_flush();
6210 	}
6211 	else if (eap->cmdidx == CMD_echoerr)
6212 	{
6213 	    int		save_did_emsg = did_emsg;
6214 
6215 	    // We don't want to abort following commands, restore did_emsg.
6216 	    emsg(ga.ga_data);
6217 	    if (!force_abort)
6218 		did_emsg = save_did_emsg;
6219 	}
6220 	else if (eap->cmdidx == CMD_execute)
6221 	    do_cmdline((char_u *)ga.ga_data,
6222 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
6223     }
6224 
6225     ga_clear(&ga);
6226 
6227     if (eap->skip)
6228 	--emsg_skip;
6229 
6230     eap->nextcmd = check_nextcmd(arg);
6231 }
6232 
6233 /*
6234  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
6235  * "arg" points to the "&" or '+' when called, to "option" when returning.
6236  * Returns NULL when no option name found.  Otherwise pointer to the char
6237  * after the option name.
6238  */
6239     char_u *
6240 find_option_end(char_u **arg, int *opt_flags)
6241 {
6242     char_u	*p = *arg;
6243 
6244     ++p;
6245     if (*p == 'g' && p[1] == ':')
6246     {
6247 	*opt_flags = OPT_GLOBAL;
6248 	p += 2;
6249     }
6250     else if (*p == 'l' && p[1] == ':')
6251     {
6252 	*opt_flags = OPT_LOCAL;
6253 	p += 2;
6254     }
6255     else
6256 	*opt_flags = 0;
6257 
6258     if (!ASCII_ISALPHA(*p))
6259 	return NULL;
6260     *arg = p;
6261 
6262     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
6263 	p += 4;	    // termcap option
6264     else
6265 	while (ASCII_ISALPHA(*p))
6266 	    ++p;
6267     return p;
6268 }
6269 
6270 /*
6271  * Display script name where an item was last set.
6272  * Should only be invoked when 'verbose' is non-zero.
6273  */
6274     void
6275 last_set_msg(sctx_T script_ctx)
6276 {
6277     char_u *p;
6278 
6279     if (script_ctx.sc_sid != 0)
6280     {
6281 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
6282 	if (p != NULL)
6283 	{
6284 	    verbose_enter();
6285 	    msg_puts(_("\n\tLast set from "));
6286 	    msg_puts((char *)p);
6287 	    if (script_ctx.sc_lnum > 0)
6288 	    {
6289 		msg_puts(_(line_msg));
6290 		msg_outnum((long)script_ctx.sc_lnum);
6291 	    }
6292 	    verbose_leave();
6293 	    vim_free(p);
6294 	}
6295     }
6296 }
6297 
6298 /*
6299  * Compare "typ1" and "typ2".  Put the result in "typ1".
6300  */
6301     int
6302 typval_compare(
6303     typval_T	*typ1,   // first operand
6304     typval_T	*typ2,   // second operand
6305     exptype_T	type,    // operator
6306     int		ic)      // ignore case
6307 {
6308     int		i;
6309     varnumber_T	n1, n2;
6310     char_u	*s1, *s2;
6311     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
6312     int		type_is = type == EXPR_IS || type == EXPR_ISNOT;
6313 
6314     if (type_is && typ1->v_type != typ2->v_type)
6315     {
6316 	// For "is" a different type always means FALSE, for "notis"
6317 	// it means TRUE.
6318 	n1 = (type == EXPR_ISNOT);
6319     }
6320     else if (typ1->v_type == VAR_BLOB || typ2->v_type == VAR_BLOB)
6321     {
6322 	if (type_is)
6323 	{
6324 	    n1 = (typ1->v_type == typ2->v_type
6325 			    && typ1->vval.v_blob == typ2->vval.v_blob);
6326 	    if (type == EXPR_ISNOT)
6327 		n1 = !n1;
6328 	}
6329 	else if (typ1->v_type != typ2->v_type
6330 		|| (type != EXPR_EQUAL && type != EXPR_NEQUAL))
6331 	{
6332 	    if (typ1->v_type != typ2->v_type)
6333 		emsg(_("E977: Can only compare Blob with Blob"));
6334 	    else
6335 		emsg(_(e_invalblob));
6336 	    clear_tv(typ1);
6337 	    return FAIL;
6338 	}
6339 	else
6340 	{
6341 	    // Compare two Blobs for being equal or unequal.
6342 	    n1 = blob_equal(typ1->vval.v_blob, typ2->vval.v_blob);
6343 	    if (type == EXPR_NEQUAL)
6344 		n1 = !n1;
6345 	}
6346     }
6347     else if (typ1->v_type == VAR_LIST || typ2->v_type == VAR_LIST)
6348     {
6349 	if (type_is)
6350 	{
6351 	    n1 = (typ1->v_type == typ2->v_type
6352 			    && typ1->vval.v_list == typ2->vval.v_list);
6353 	    if (type == EXPR_ISNOT)
6354 		n1 = !n1;
6355 	}
6356 	else if (typ1->v_type != typ2->v_type
6357 		|| (type != EXPR_EQUAL && type != EXPR_NEQUAL))
6358 	{
6359 	    if (typ1->v_type != typ2->v_type)
6360 		emsg(_("E691: Can only compare List with List"));
6361 	    else
6362 		emsg(_("E692: Invalid operation for List"));
6363 	    clear_tv(typ1);
6364 	    return FAIL;
6365 	}
6366 	else
6367 	{
6368 	    // Compare two Lists for being equal or unequal.
6369 	    n1 = list_equal(typ1->vval.v_list, typ2->vval.v_list,
6370 							    ic, FALSE);
6371 	    if (type == EXPR_NEQUAL)
6372 		n1 = !n1;
6373 	}
6374     }
6375 
6376     else if (typ1->v_type == VAR_DICT || typ2->v_type == VAR_DICT)
6377     {
6378 	if (type_is)
6379 	{
6380 	    n1 = (typ1->v_type == typ2->v_type
6381 			    && typ1->vval.v_dict == typ2->vval.v_dict);
6382 	    if (type == EXPR_ISNOT)
6383 		n1 = !n1;
6384 	}
6385 	else if (typ1->v_type != typ2->v_type
6386 		|| (type != EXPR_EQUAL && type != EXPR_NEQUAL))
6387 	{
6388 	    if (typ1->v_type != typ2->v_type)
6389 		emsg(_("E735: Can only compare Dictionary with Dictionary"));
6390 	    else
6391 		emsg(_("E736: Invalid operation for Dictionary"));
6392 	    clear_tv(typ1);
6393 	    return FAIL;
6394 	}
6395 	else
6396 	{
6397 	    // Compare two Dictionaries for being equal or unequal.
6398 	    n1 = dict_equal(typ1->vval.v_dict, typ2->vval.v_dict,
6399 							    ic, FALSE);
6400 	    if (type == EXPR_NEQUAL)
6401 		n1 = !n1;
6402 	}
6403     }
6404 
6405     else if (typ1->v_type == VAR_FUNC || typ2->v_type == VAR_FUNC
6406 	|| typ1->v_type == VAR_PARTIAL || typ2->v_type == VAR_PARTIAL)
6407     {
6408 	if (type != EXPR_EQUAL && type != EXPR_NEQUAL
6409 		&& type != EXPR_IS && type != EXPR_ISNOT)
6410 	{
6411 	    emsg(_("E694: Invalid operation for Funcrefs"));
6412 	    clear_tv(typ1);
6413 	    return FAIL;
6414 	}
6415 	if ((typ1->v_type == VAR_PARTIAL
6416 					&& typ1->vval.v_partial == NULL)
6417 		|| (typ2->v_type == VAR_PARTIAL
6418 					&& typ2->vval.v_partial == NULL))
6419 	    // when a partial is NULL assume not equal
6420 	    n1 = FALSE;
6421 	else if (type_is)
6422 	{
6423 	    if (typ1->v_type == VAR_FUNC && typ2->v_type == VAR_FUNC)
6424 		// strings are considered the same if their value is
6425 		// the same
6426 		n1 = tv_equal(typ1, typ2, ic, FALSE);
6427 	    else if (typ1->v_type == VAR_PARTIAL
6428 					&& typ2->v_type == VAR_PARTIAL)
6429 		n1 = (typ1->vval.v_partial == typ2->vval.v_partial);
6430 	    else
6431 		n1 = FALSE;
6432 	}
6433 	else
6434 	    n1 = tv_equal(typ1, typ2, ic, FALSE);
6435 	if (type == EXPR_NEQUAL || type == EXPR_ISNOT)
6436 	    n1 = !n1;
6437     }
6438 
6439 #ifdef FEAT_FLOAT
6440     /*
6441 	* If one of the two variables is a float, compare as a float.
6442 	* When using "=~" or "!~", always compare as string.
6443 	*/
6444     else if ((typ1->v_type == VAR_FLOAT || typ2->v_type == VAR_FLOAT)
6445 	    && type != EXPR_MATCH && type != EXPR_NOMATCH)
6446     {
6447 	float_T f1, f2;
6448 
6449 	f1 = tv_get_float(typ1);
6450 	f2 = tv_get_float(typ2);
6451 	n1 = FALSE;
6452 	switch (type)
6453 	{
6454 	    case EXPR_IS:
6455 	    case EXPR_EQUAL:    n1 = (f1 == f2); break;
6456 	    case EXPR_ISNOT:
6457 	    case EXPR_NEQUAL:   n1 = (f1 != f2); break;
6458 	    case EXPR_GREATER:  n1 = (f1 > f2); break;
6459 	    case EXPR_GEQUAL:   n1 = (f1 >= f2); break;
6460 	    case EXPR_SMALLER:  n1 = (f1 < f2); break;
6461 	    case EXPR_SEQUAL:   n1 = (f1 <= f2); break;
6462 	    case EXPR_UNKNOWN:
6463 	    case EXPR_MATCH:
6464 	    default:  break;  // avoid gcc warning
6465 	}
6466     }
6467 #endif
6468 
6469     /*
6470      * If one of the two variables is a number, compare as a number.
6471      * When using "=~" or "!~", always compare as string.
6472      */
6473     else if ((typ1->v_type == VAR_NUMBER || typ2->v_type == VAR_NUMBER)
6474 	    && type != EXPR_MATCH && type != EXPR_NOMATCH)
6475     {
6476 	n1 = tv_get_number(typ1);
6477 	n2 = tv_get_number(typ2);
6478 	switch (type)
6479 	{
6480 	    case EXPR_IS:
6481 	    case EXPR_EQUAL:    n1 = (n1 == n2); break;
6482 	    case EXPR_ISNOT:
6483 	    case EXPR_NEQUAL:   n1 = (n1 != n2); break;
6484 	    case EXPR_GREATER:  n1 = (n1 > n2); break;
6485 	    case EXPR_GEQUAL:   n1 = (n1 >= n2); break;
6486 	    case EXPR_SMALLER:  n1 = (n1 < n2); break;
6487 	    case EXPR_SEQUAL:   n1 = (n1 <= n2); break;
6488 	    case EXPR_UNKNOWN:
6489 	    case EXPR_MATCH:
6490 	    default:  break;  // avoid gcc warning
6491 	}
6492     }
6493     else
6494     {
6495 	s1 = tv_get_string_buf(typ1, buf1);
6496 	s2 = tv_get_string_buf(typ2, buf2);
6497 	if (type != EXPR_MATCH && type != EXPR_NOMATCH)
6498 	    i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
6499 	else
6500 	    i = 0;
6501 	n1 = FALSE;
6502 	switch (type)
6503 	{
6504 	    case EXPR_IS:
6505 	    case EXPR_EQUAL:    n1 = (i == 0); break;
6506 	    case EXPR_ISNOT:
6507 	    case EXPR_NEQUAL:   n1 = (i != 0); break;
6508 	    case EXPR_GREATER:  n1 = (i > 0); break;
6509 	    case EXPR_GEQUAL:   n1 = (i >= 0); break;
6510 	    case EXPR_SMALLER:  n1 = (i < 0); break;
6511 	    case EXPR_SEQUAL:   n1 = (i <= 0); break;
6512 
6513 	    case EXPR_MATCH:
6514 	    case EXPR_NOMATCH:
6515 		    n1 = pattern_match(s2, s1, ic);
6516 		    if (type == EXPR_NOMATCH)
6517 			n1 = !n1;
6518 		    break;
6519 
6520 	    default:  break;  // avoid gcc warning
6521 	}
6522     }
6523     clear_tv(typ1);
6524     typ1->v_type = VAR_NUMBER;
6525     typ1->vval.v_number = n1;
6526 
6527     return OK;
6528 }
6529 
6530     char_u *
6531 typval_tostring(typval_T *arg)
6532 {
6533     char_u	*tofree;
6534     char_u	numbuf[NUMBUFLEN];
6535     char_u	*ret = NULL;
6536 
6537     if (arg == NULL)
6538 	return vim_strsave((char_u *)"(does not exist)");
6539     ret = tv2string(arg, &tofree, numbuf, 0);
6540     // Make a copy if we have a value but it's not in allocated memory.
6541     if (ret != NULL && tofree == NULL)
6542 	ret = vim_strsave(ret);
6543     return ret;
6544 }
6545 
6546 #endif // FEAT_EVAL
6547 
6548 /*
6549  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
6550  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
6551  * "flags" can be "g" to do a global substitute.
6552  * Returns an allocated string, NULL for error.
6553  */
6554     char_u *
6555 do_string_sub(
6556     char_u	*str,
6557     char_u	*pat,
6558     char_u	*sub,
6559     typval_T	*expr,
6560     char_u	*flags)
6561 {
6562     int		sublen;
6563     regmatch_T	regmatch;
6564     int		i;
6565     int		do_all;
6566     char_u	*tail;
6567     char_u	*end;
6568     garray_T	ga;
6569     char_u	*ret;
6570     char_u	*save_cpo;
6571     char_u	*zero_width = NULL;
6572 
6573     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
6574     save_cpo = p_cpo;
6575     p_cpo = empty_option;
6576 
6577     ga_init2(&ga, 1, 200);
6578 
6579     do_all = (flags[0] == 'g');
6580 
6581     regmatch.rm_ic = p_ic;
6582     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
6583     if (regmatch.regprog != NULL)
6584     {
6585 	tail = str;
6586 	end = str + STRLEN(str);
6587 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
6588 	{
6589 	    // Skip empty match except for first match.
6590 	    if (regmatch.startp[0] == regmatch.endp[0])
6591 	    {
6592 		if (zero_width == regmatch.startp[0])
6593 		{
6594 		    // avoid getting stuck on a match with an empty string
6595 		    i = mb_ptr2len(tail);
6596 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
6597 								   (size_t)i);
6598 		    ga.ga_len += i;
6599 		    tail += i;
6600 		    continue;
6601 		}
6602 		zero_width = regmatch.startp[0];
6603 	    }
6604 
6605 	    /*
6606 	     * Get some space for a temporary buffer to do the substitution
6607 	     * into.  It will contain:
6608 	     * - The text up to where the match is.
6609 	     * - The substituted text.
6610 	     * - The text after the match.
6611 	     */
6612 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
6613 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
6614 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
6615 	    {
6616 		ga_clear(&ga);
6617 		break;
6618 	    }
6619 
6620 	    // copy the text up to where the match is
6621 	    i = (int)(regmatch.startp[0] - tail);
6622 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
6623 	    // add the substituted text
6624 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
6625 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
6626 	    ga.ga_len += i + sublen - 1;
6627 	    tail = regmatch.endp[0];
6628 	    if (*tail == NUL)
6629 		break;
6630 	    if (!do_all)
6631 		break;
6632 	}
6633 
6634 	if (ga.ga_data != NULL)
6635 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
6636 
6637 	vim_regfree(regmatch.regprog);
6638     }
6639 
6640     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
6641     ga_clear(&ga);
6642     if (p_cpo == empty_option)
6643 	p_cpo = save_cpo;
6644     else
6645 	// Darn, evaluating {sub} expression or {expr} changed the value.
6646 	free_string_option(save_cpo);
6647 
6648     return ret;
6649 }
6650