xref: /vim-8.2.3635/src/eval.c (revision beae4084)
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 static int echo_attr = 0;   // attributes used for ":echo"
38 
39 /*
40  * Info used by a ":for" loop.
41  */
42 typedef struct
43 {
44     int		fi_semicolon;	// TRUE if ending in '; var]'
45     int		fi_varcount;	// nr of variables in the list
46     listwatch_T	fi_lw;		// keep an eye on the item used.
47     list_T	*fi_list;	// list being used
48     int		fi_bi;		// index of blob
49     blob_T	*fi_blob;	// blob being used
50 } forinfo_T;
51 
52 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
53 static int eval2(char_u **arg, typval_T *rettv, int evaluate);
54 static int eval3(char_u **arg, typval_T *rettv, int evaluate);
55 static int eval4(char_u **arg, typval_T *rettv, int evaluate);
56 static int eval5(char_u **arg, typval_T *rettv, int evaluate);
57 static int eval6(char_u **arg, typval_T *rettv, int evaluate, int want_string);
58 static int eval7(char_u **arg, typval_T *rettv, int evaluate, int want_string);
59 static int eval7_leader(typval_T *rettv, char_u *start_leader, char_u **end_leaderp);
60 
61 static int free_unref_items(int copyID);
62 static char_u *make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
63 static int tv_check_lock(typval_T *tv, char_u *name, int use_gettext);
64 
65 /*
66  * Return "n1" divided by "n2", taking care of dividing by zero.
67  */
68 	varnumber_T
69 num_divide(varnumber_T n1, varnumber_T n2)
70 {
71     varnumber_T	result;
72 
73     if (n2 == 0)	// give an error message?
74     {
75 	if (n1 == 0)
76 	    result = VARNUM_MIN; // similar to NaN
77 	else if (n1 < 0)
78 	    result = -VARNUM_MAX;
79 	else
80 	    result = VARNUM_MAX;
81     }
82     else
83 	result = n1 / n2;
84 
85     return result;
86 }
87 
88 /*
89  * Return "n1" modulus "n2", taking care of dividing by zero.
90  */
91 	varnumber_T
92 num_modulus(varnumber_T n1, varnumber_T n2)
93 {
94     // Give an error when n2 is 0?
95     return (n2 == 0) ? 0 : (n1 % n2);
96 }
97 
98 #if defined(EBCDIC) || defined(PROTO)
99 /*
100  * Compare struct fst by function name.
101  */
102     static int
103 compare_func_name(const void *s1, const void *s2)
104 {
105     struct fst *p1 = (struct fst *)s1;
106     struct fst *p2 = (struct fst *)s2;
107 
108     return STRCMP(p1->f_name, p2->f_name);
109 }
110 
111 /*
112  * Sort the function table by function name.
113  * The sorting of the table above is ASCII dependent.
114  * On machines using EBCDIC we have to sort it.
115  */
116     static void
117 sortFunctions(void)
118 {
119     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
120 
121     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
122 }
123 #endif
124 
125 /*
126  * Initialize the global and v: variables.
127  */
128     void
129 eval_init(void)
130 {
131     evalvars_init();
132     func_init();
133 
134 #ifdef EBCDIC
135     /*
136      * Sort the function table, to enable binary search.
137      */
138     sortFunctions();
139 #endif
140 }
141 
142 #if defined(EXITFREE) || defined(PROTO)
143     void
144 eval_clear(void)
145 {
146     evalvars_clear();
147     free_scriptnames();  // must come after evalvars_clear().
148     free_locales();
149 
150     // autoloaded script names
151     free_autoload_scriptnames();
152 
153     // unreferenced lists and dicts
154     (void)garbage_collect(FALSE);
155 
156     // functions not garbage collected
157     free_all_functions();
158 }
159 #endif
160 
161 /*
162  * Top level evaluation function, returning a boolean.
163  * Sets "error" to TRUE if there was an error.
164  * Return TRUE or FALSE.
165  */
166     int
167 eval_to_bool(
168     char_u	*arg,
169     int		*error,
170     char_u	**nextcmd,
171     int		skip)	    // only parse, don't execute
172 {
173     typval_T	tv;
174     varnumber_T	retval = FALSE;
175 
176     if (skip)
177 	++emsg_skip;
178     if (eval0(arg, &tv, nextcmd, !skip) == FAIL)
179 	*error = TRUE;
180     else
181     {
182 	*error = FALSE;
183 	if (!skip)
184 	{
185 	    retval = (tv_get_number_chk(&tv, error) != 0);
186 	    clear_tv(&tv);
187 	}
188     }
189     if (skip)
190 	--emsg_skip;
191 
192     return (int)retval;
193 }
194 
195 /*
196  * Call eval1() and give an error message if not done at a lower level.
197  */
198     static int
199 eval1_emsg(char_u **arg, typval_T *rettv, int evaluate)
200 {
201     char_u	*start = *arg;
202     int		ret;
203     int		did_emsg_before = did_emsg;
204     int		called_emsg_before = called_emsg;
205 
206     ret = eval1(arg, rettv, evaluate);
207     if (ret == FAIL)
208     {
209 	// Report the invalid expression unless the expression evaluation has
210 	// been cancelled due to an aborting error, an interrupt, or an
211 	// exception, or we already gave a more specific error.
212 	// Also check called_emsg for when using assert_fails().
213 	if (!aborting() && did_emsg == did_emsg_before
214 					  && called_emsg == called_emsg_before)
215 	    semsg(_(e_invexpr2), start);
216     }
217     return ret;
218 }
219 
220 /*
221  * Evaluate an expression, which can be a function, partial or string.
222  * Pass arguments "argv[argc]".
223  * Return the result in "rettv" and OK or FAIL.
224  */
225     int
226 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
227 {
228     char_u	*s;
229     char_u	buf[NUMBUFLEN];
230     funcexe_T	funcexe;
231 
232     if (expr->v_type == VAR_FUNC)
233     {
234 	s = expr->vval.v_string;
235 	if (s == NULL || *s == NUL)
236 	    return FAIL;
237 	CLEAR_FIELD(funcexe);
238 	funcexe.evaluate = TRUE;
239 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
240 	    return FAIL;
241     }
242     else if (expr->v_type == VAR_PARTIAL)
243     {
244 	partial_T   *partial = expr->vval.v_partial;
245 
246 	if (partial->pt_func != NULL && partial->pt_func->uf_dfunc_idx >= 0)
247 	{
248 	    if (call_def_function(partial->pt_func, argc, argv, rettv) == FAIL)
249 		return FAIL;
250 	}
251 	else
252 	{
253 	    s = partial_name(partial);
254 	    if (s == NULL || *s == NUL)
255 		return FAIL;
256 	    CLEAR_FIELD(funcexe);
257 	    funcexe.evaluate = TRUE;
258 	    funcexe.partial = partial;
259 	    if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
260 		return FAIL;
261 	}
262     }
263     else
264     {
265 	s = tv_get_string_buf_chk(expr, buf);
266 	if (s == NULL)
267 	    return FAIL;
268 	s = skipwhite(s);
269 	if (eval1_emsg(&s, rettv, TRUE) == FAIL)
270 	    return FAIL;
271 	if (*s != NUL)  // check for trailing chars after expr
272 	{
273 	    clear_tv(rettv);
274 	    semsg(_(e_invexpr2), s);
275 	    return FAIL;
276 	}
277     }
278     return OK;
279 }
280 
281 /*
282  * Like eval_to_bool() but using a typval_T instead of a string.
283  * Works for string, funcref and partial.
284  */
285     int
286 eval_expr_to_bool(typval_T *expr, int *error)
287 {
288     typval_T	rettv;
289     int		res;
290 
291     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
292     {
293 	*error = TRUE;
294 	return FALSE;
295     }
296     res = (tv_get_number_chk(&rettv, error) != 0);
297     clear_tv(&rettv);
298     return res;
299 }
300 
301 /*
302  * Top level evaluation function, returning a string.  If "skip" is TRUE,
303  * only parsing to "nextcmd" is done, without reporting errors.  Return
304  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
305  */
306     char_u *
307 eval_to_string_skip(
308     char_u	*arg,
309     char_u	**nextcmd,
310     int		skip)	    // only parse, don't execute
311 {
312     typval_T	tv;
313     char_u	*retval;
314 
315     if (skip)
316 	++emsg_skip;
317     if (eval0(arg, &tv, nextcmd, !skip) == FAIL || skip)
318 	retval = NULL;
319     else
320     {
321 	retval = vim_strsave(tv_get_string(&tv));
322 	clear_tv(&tv);
323     }
324     if (skip)
325 	--emsg_skip;
326 
327     return retval;
328 }
329 
330 /*
331  * Skip over an expression at "*pp".
332  * Return FAIL for an error, OK otherwise.
333  */
334     int
335 skip_expr(char_u **pp)
336 {
337     typval_T	rettv;
338 
339     *pp = skipwhite(*pp);
340     return eval1(pp, &rettv, FALSE);
341 }
342 
343 /*
344  * Top level evaluation function, returning a string.
345  * When "convert" is TRUE convert a List into a sequence of lines and convert
346  * a Float to a String.
347  * Return pointer to allocated memory, or NULL for failure.
348  */
349     char_u *
350 eval_to_string(
351     char_u	*arg,
352     char_u	**nextcmd,
353     int		convert)
354 {
355     typval_T	tv;
356     char_u	*retval;
357     garray_T	ga;
358 #ifdef FEAT_FLOAT
359     char_u	numbuf[NUMBUFLEN];
360 #endif
361 
362     if (eval0(arg, &tv, nextcmd, TRUE) == FAIL)
363 	retval = NULL;
364     else
365     {
366 	if (convert && tv.v_type == VAR_LIST)
367 	{
368 	    ga_init2(&ga, (int)sizeof(char), 80);
369 	    if (tv.vval.v_list != NULL)
370 	    {
371 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
372 		if (tv.vval.v_list->lv_len > 0)
373 		    ga_append(&ga, NL);
374 	    }
375 	    ga_append(&ga, NUL);
376 	    retval = (char_u *)ga.ga_data;
377 	}
378 #ifdef FEAT_FLOAT
379 	else if (convert && tv.v_type == VAR_FLOAT)
380 	{
381 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
382 	    retval = vim_strsave(numbuf);
383 	}
384 #endif
385 	else
386 	    retval = vim_strsave(tv_get_string(&tv));
387 	clear_tv(&tv);
388     }
389 
390     return retval;
391 }
392 
393 /*
394  * Call eval_to_string() without using current local variables and using
395  * textlock.  When "use_sandbox" is TRUE use the sandbox.
396  */
397     char_u *
398 eval_to_string_safe(
399     char_u	*arg,
400     char_u	**nextcmd,
401     int		use_sandbox)
402 {
403     char_u	*retval;
404     funccal_entry_T funccal_entry;
405 
406     save_funccal(&funccal_entry);
407     if (use_sandbox)
408 	++sandbox;
409     ++textlock;
410     retval = eval_to_string(arg, nextcmd, FALSE);
411     if (use_sandbox)
412 	--sandbox;
413     --textlock;
414     restore_funccal();
415     return retval;
416 }
417 
418 /*
419  * Top level evaluation function, returning a number.
420  * Evaluates "expr" silently.
421  * Returns -1 for an error.
422  */
423     varnumber_T
424 eval_to_number(char_u *expr)
425 {
426     typval_T	rettv;
427     varnumber_T	retval;
428     char_u	*p = skipwhite(expr);
429 
430     ++emsg_off;
431 
432     if (eval1(&p, &rettv, TRUE) == FAIL)
433 	retval = -1;
434     else
435     {
436 	retval = tv_get_number_chk(&rettv, NULL);
437 	clear_tv(&rettv);
438     }
439     --emsg_off;
440 
441     return retval;
442 }
443 
444 /*
445  * Top level evaluation function.
446  * Returns an allocated typval_T with the result.
447  * Returns NULL when there is an error.
448  */
449     typval_T *
450 eval_expr(char_u *arg, char_u **nextcmd)
451 {
452     typval_T	*tv;
453 
454     tv = ALLOC_ONE(typval_T);
455     if (tv != NULL && eval0(arg, tv, nextcmd, TRUE) == FAIL)
456 	VIM_CLEAR(tv);
457 
458     return tv;
459 }
460 
461 /*
462  * Call some Vim script function and return the result in "*rettv".
463  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
464  * should have type VAR_UNKNOWN.
465  * Returns OK or FAIL.
466  */
467     int
468 call_vim_function(
469     char_u      *func,
470     int		argc,
471     typval_T	*argv,
472     typval_T	*rettv)
473 {
474     int		ret;
475     funcexe_T	funcexe;
476 
477     rettv->v_type = VAR_UNKNOWN;		// clear_tv() uses this
478     CLEAR_FIELD(funcexe);
479     funcexe.firstline = curwin->w_cursor.lnum;
480     funcexe.lastline = curwin->w_cursor.lnum;
481     funcexe.evaluate = TRUE;
482     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
483     if (ret == FAIL)
484 	clear_tv(rettv);
485 
486     return ret;
487 }
488 
489 /*
490  * Call Vim script function "func" and return the result as a number.
491  * Returns -1 when calling the function fails.
492  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
493  * have type VAR_UNKNOWN.
494  */
495     varnumber_T
496 call_func_retnr(
497     char_u      *func,
498     int		argc,
499     typval_T	*argv)
500 {
501     typval_T	rettv;
502     varnumber_T	retval;
503 
504     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
505 	return -1;
506 
507     retval = tv_get_number_chk(&rettv, NULL);
508     clear_tv(&rettv);
509     return retval;
510 }
511 
512 /*
513  * Call Vim script function "func" and return the result as a string.
514  * Returns NULL when calling the function fails.
515  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
516  * have type VAR_UNKNOWN.
517  */
518     void *
519 call_func_retstr(
520     char_u      *func,
521     int		argc,
522     typval_T	*argv)
523 {
524     typval_T	rettv;
525     char_u	*retval;
526 
527     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
528 	return NULL;
529 
530     retval = vim_strsave(tv_get_string(&rettv));
531     clear_tv(&rettv);
532     return retval;
533 }
534 
535 /*
536  * Call Vim script function "func" and return the result as a List.
537  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
538  * have type VAR_UNKNOWN.
539  * Returns NULL when there is something wrong.
540  */
541     void *
542 call_func_retlist(
543     char_u      *func,
544     int		argc,
545     typval_T	*argv)
546 {
547     typval_T	rettv;
548 
549     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
550 	return NULL;
551 
552     if (rettv.v_type != VAR_LIST)
553     {
554 	clear_tv(&rettv);
555 	return NULL;
556     }
557 
558     return rettv.vval.v_list;
559 }
560 
561 #ifdef FEAT_FOLDING
562 /*
563  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
564  * it in "*cp".  Doesn't give error messages.
565  */
566     int
567 eval_foldexpr(char_u *arg, int *cp)
568 {
569     typval_T	tv;
570     varnumber_T	retval;
571     char_u	*s;
572     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
573 								   OPT_LOCAL);
574 
575     ++emsg_off;
576     if (use_sandbox)
577 	++sandbox;
578     ++textlock;
579     *cp = NUL;
580     if (eval0(arg, &tv, NULL, TRUE) == FAIL)
581 	retval = 0;
582     else
583     {
584 	// If the result is a number, just return the number.
585 	if (tv.v_type == VAR_NUMBER)
586 	    retval = tv.vval.v_number;
587 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
588 	    retval = 0;
589 	else
590 	{
591 	    // If the result is a string, check if there is a non-digit before
592 	    // the number.
593 	    s = tv.vval.v_string;
594 	    if (!VIM_ISDIGIT(*s) && *s != '-')
595 		*cp = *s++;
596 	    retval = atol((char *)s);
597 	}
598 	clear_tv(&tv);
599     }
600     --emsg_off;
601     if (use_sandbox)
602 	--sandbox;
603     --textlock;
604 
605     return (int)retval;
606 }
607 #endif
608 
609 /*
610  * Get an lval: variable, Dict item or List item that can be assigned a value
611  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
612  * "name.key", "name.key[expr]" etc.
613  * Indexing only works if "name" is an existing List or Dictionary.
614  * "name" points to the start of the name.
615  * If "rettv" is not NULL it points to the value to be assigned.
616  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
617  * wrong; must end in space or cmd separator.
618  *
619  * flags:
620  *  GLV_QUIET:       do not give error messages
621  *  GLV_READ_ONLY:   will not change the variable
622  *  GLV_NO_AUTOLOAD: do not use script autoloading
623  *
624  * Returns a pointer to just after the name, including indexes.
625  * When an evaluation error occurs "lp->ll_name" is NULL;
626  * Returns NULL for a parsing error.  Still need to free items in "lp"!
627  */
628     char_u *
629 get_lval(
630     char_u	*name,
631     typval_T	*rettv,
632     lval_T	*lp,
633     int		unlet,
634     int		skip,
635     int		flags,	    // GLV_ values
636     int		fne_flags)  // flags for find_name_end()
637 {
638     char_u	*p;
639     char_u	*expr_start, *expr_end;
640     int		cc;
641     dictitem_T	*v;
642     typval_T	var1;
643     typval_T	var2;
644     int		empty1 = FALSE;
645     listitem_T	*ni;
646     char_u	*key = NULL;
647     int		len;
648     hashtab_T	*ht;
649     int		quiet = flags & GLV_QUIET;
650 
651     // Clear everything in "lp".
652     CLEAR_POINTER(lp);
653 
654     if (skip)
655     {
656 	// When skipping just find the end of the name.
657 	lp->ll_name = name;
658 	return find_name_end(name, NULL, NULL, FNE_INCL_BR | fne_flags);
659     }
660 
661     // Find the end of the name.
662     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
663     lp->ll_name_end = p;
664     if (expr_start != NULL)
665     {
666 	// Don't expand the name when we already know there is an error.
667 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
668 						    && *p != '[' && *p != '.')
669 	{
670 	    emsg(_(e_trailing));
671 	    return NULL;
672 	}
673 
674 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
675 	if (lp->ll_exp_name == NULL)
676 	{
677 	    // Report an invalid expression in braces, unless the
678 	    // expression evaluation has been cancelled due to an
679 	    // aborting error, an interrupt, or an exception.
680 	    if (!aborting() && !quiet)
681 	    {
682 		emsg_severe = TRUE;
683 		semsg(_(e_invarg2), name);
684 		return NULL;
685 	    }
686 	}
687 	lp->ll_name = lp->ll_exp_name;
688     }
689     else
690     {
691 	lp->ll_name = name;
692 
693 	if (current_sctx.sc_version == SCRIPT_VERSION_VIM9 && *p == ':')
694 	{
695 	    scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);
696 	    char_u	 *tp = skipwhite(p + 1);
697 
698 	    // parse the type after the name
699 	    lp->ll_type = parse_type(&tp, &si->sn_type_list);
700 	    lp->ll_name_end = tp;
701 	}
702     }
703 
704     // Without [idx] or .key we are done.
705     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
706 	return p;
707 
708     cc = *p;
709     *p = NUL;
710     // Only pass &ht when we would write to the variable, it prevents autoload
711     // as well.
712     v = find_var(lp->ll_name, (flags & GLV_READ_ONLY) ? NULL : &ht,
713 						      flags & GLV_NO_AUTOLOAD);
714     if (v == NULL && !quiet)
715 	semsg(_(e_undefvar), lp->ll_name);
716     *p = cc;
717     if (v == NULL)
718 	return NULL;
719 
720     /*
721      * Loop until no more [idx] or .key is following.
722      */
723     lp->ll_tv = &v->di_tv;
724     var1.v_type = VAR_UNKNOWN;
725     var2.v_type = VAR_UNKNOWN;
726     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
727     {
728 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
729 		&& !(lp->ll_tv->v_type == VAR_DICT
730 					   && lp->ll_tv->vval.v_dict != NULL)
731 		&& !(lp->ll_tv->v_type == VAR_BLOB
732 					   && lp->ll_tv->vval.v_blob != NULL))
733 	{
734 	    if (!quiet)
735 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
736 	    return NULL;
737 	}
738 	if (lp->ll_range)
739 	{
740 	    if (!quiet)
741 		emsg(_("E708: [:] must come last"));
742 	    return NULL;
743 	}
744 
745 	len = -1;
746 	if (*p == '.')
747 	{
748 	    key = p + 1;
749 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
750 		;
751 	    if (len == 0)
752 	    {
753 		if (!quiet)
754 		    emsg(_(e_emptykey));
755 		return NULL;
756 	    }
757 	    p = key + len;
758 	}
759 	else
760 	{
761 	    // Get the index [expr] or the first index [expr: ].
762 	    p = skipwhite(p + 1);
763 	    if (*p == ':')
764 		empty1 = TRUE;
765 	    else
766 	    {
767 		empty1 = FALSE;
768 		if (eval1(&p, &var1, TRUE) == FAIL)	// recursive!
769 		    return NULL;
770 		if (tv_get_string_chk(&var1) == NULL)
771 		{
772 		    // not a number or string
773 		    clear_tv(&var1);
774 		    return NULL;
775 		}
776 	    }
777 
778 	    // Optionally get the second index [ :expr].
779 	    if (*p == ':')
780 	    {
781 		if (lp->ll_tv->v_type == VAR_DICT)
782 		{
783 		    if (!quiet)
784 			emsg(_(e_dictrange));
785 		    clear_tv(&var1);
786 		    return NULL;
787 		}
788 		if (rettv != NULL
789 			&& !(rettv->v_type == VAR_LIST
790 						 && rettv->vval.v_list != NULL)
791 			&& !(rettv->v_type == VAR_BLOB
792 						&& rettv->vval.v_blob != NULL))
793 		{
794 		    if (!quiet)
795 			emsg(_("E709: [:] requires a List or Blob value"));
796 		    clear_tv(&var1);
797 		    return NULL;
798 		}
799 		p = skipwhite(p + 1);
800 		if (*p == ']')
801 		    lp->ll_empty2 = TRUE;
802 		else
803 		{
804 		    lp->ll_empty2 = FALSE;
805 		    if (eval1(&p, &var2, TRUE) == FAIL)	// recursive!
806 		    {
807 			clear_tv(&var1);
808 			return NULL;
809 		    }
810 		    if (tv_get_string_chk(&var2) == NULL)
811 		    {
812 			// not a number or string
813 			clear_tv(&var1);
814 			clear_tv(&var2);
815 			return NULL;
816 		    }
817 		}
818 		lp->ll_range = TRUE;
819 	    }
820 	    else
821 		lp->ll_range = FALSE;
822 
823 	    if (*p != ']')
824 	    {
825 		if (!quiet)
826 		    emsg(_(e_missbrac));
827 		clear_tv(&var1);
828 		clear_tv(&var2);
829 		return NULL;
830 	    }
831 
832 	    // Skip to past ']'.
833 	    ++p;
834 	}
835 
836 	if (lp->ll_tv->v_type == VAR_DICT)
837 	{
838 	    if (len == -1)
839 	    {
840 		// "[key]": get key from "var1"
841 		key = tv_get_string_chk(&var1);	// is number or string
842 		if (key == NULL)
843 		{
844 		    clear_tv(&var1);
845 		    return NULL;
846 		}
847 	    }
848 	    lp->ll_list = NULL;
849 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
850 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
851 
852 	    // When assigning to a scope dictionary check that a function and
853 	    // variable name is valid (only variable name unless it is l: or
854 	    // g: dictionary). Disallow overwriting a builtin function.
855 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
856 	    {
857 		int prevval;
858 		int wrong;
859 
860 		if (len != -1)
861 		{
862 		    prevval = key[len];
863 		    key[len] = NUL;
864 		}
865 		else
866 		    prevval = 0; // avoid compiler warning
867 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
868 			       && rettv->v_type == VAR_FUNC
869 			       && var_check_func_name(key, lp->ll_di == NULL))
870 			|| !valid_varname(key);
871 		if (len != -1)
872 		    key[len] = prevval;
873 		if (wrong)
874 		{
875 		    clear_tv(&var1);
876 		    return NULL;
877 		}
878 	    }
879 
880 	    if (lp->ll_di == NULL)
881 	    {
882 		// Can't add "v:" or "a:" variable.
883 		if (lp->ll_dict == get_vimvar_dict()
884 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
885 		{
886 		    semsg(_(e_illvar), name);
887 		    clear_tv(&var1);
888 		    return NULL;
889 		}
890 
891 		// Key does not exist in dict: may need to add it.
892 		if (*p == '[' || *p == '.' || unlet)
893 		{
894 		    if (!quiet)
895 			semsg(_(e_dictkey), key);
896 		    clear_tv(&var1);
897 		    return NULL;
898 		}
899 		if (len == -1)
900 		    lp->ll_newkey = vim_strsave(key);
901 		else
902 		    lp->ll_newkey = vim_strnsave(key, len);
903 		clear_tv(&var1);
904 		if (lp->ll_newkey == NULL)
905 		    p = NULL;
906 		break;
907 	    }
908 	    // existing variable, need to check if it can be changed
909 	    else if ((flags & GLV_READ_ONLY) == 0
910 			     && var_check_ro(lp->ll_di->di_flags, name, FALSE))
911 	    {
912 		clear_tv(&var1);
913 		return NULL;
914 	    }
915 
916 	    clear_tv(&var1);
917 	    lp->ll_tv = &lp->ll_di->di_tv;
918 	}
919 	else if (lp->ll_tv->v_type == VAR_BLOB)
920 	{
921 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
922 
923 	    /*
924 	     * Get the number and item for the only or first index of the List.
925 	     */
926 	    if (empty1)
927 		lp->ll_n1 = 0;
928 	    else
929 		// is number or string
930 		lp->ll_n1 = (long)tv_get_number(&var1);
931 	    clear_tv(&var1);
932 
933 	    if (lp->ll_n1 < 0
934 		    || lp->ll_n1 > bloblen
935 		    || (lp->ll_range && lp->ll_n1 == bloblen))
936 	    {
937 		if (!quiet)
938 		    semsg(_(e_blobidx), lp->ll_n1);
939 		clear_tv(&var2);
940 		return NULL;
941 	    }
942 	    if (lp->ll_range && !lp->ll_empty2)
943 	    {
944 		lp->ll_n2 = (long)tv_get_number(&var2);
945 		clear_tv(&var2);
946 		if (lp->ll_n2 < 0
947 			|| lp->ll_n2 >= bloblen
948 			|| lp->ll_n2 < lp->ll_n1)
949 		{
950 		    if (!quiet)
951 			semsg(_(e_blobidx), lp->ll_n2);
952 		    return NULL;
953 		}
954 	    }
955 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
956 	    lp->ll_tv = NULL;
957 	    break;
958 	}
959 	else
960 	{
961 	    /*
962 	     * Get the number and item for the only or first index of the List.
963 	     */
964 	    if (empty1)
965 		lp->ll_n1 = 0;
966 	    else
967 		// is number or string
968 		lp->ll_n1 = (long)tv_get_number(&var1);
969 	    clear_tv(&var1);
970 
971 	    lp->ll_dict = NULL;
972 	    lp->ll_list = lp->ll_tv->vval.v_list;
973 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
974 	    if (lp->ll_li == NULL)
975 	    {
976 		if (lp->ll_n1 < 0)
977 		{
978 		    lp->ll_n1 = 0;
979 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
980 		}
981 	    }
982 	    if (lp->ll_li == NULL)
983 	    {
984 		clear_tv(&var2);
985 		if (!quiet)
986 		    semsg(_(e_listidx), lp->ll_n1);
987 		return NULL;
988 	    }
989 
990 	    /*
991 	     * May need to find the item or absolute index for the second
992 	     * index of a range.
993 	     * When no index given: "lp->ll_empty2" is TRUE.
994 	     * Otherwise "lp->ll_n2" is set to the second index.
995 	     */
996 	    if (lp->ll_range && !lp->ll_empty2)
997 	    {
998 		lp->ll_n2 = (long)tv_get_number(&var2);
999 						    // is number or string
1000 		clear_tv(&var2);
1001 		if (lp->ll_n2 < 0)
1002 		{
1003 		    ni = list_find(lp->ll_list, lp->ll_n2);
1004 		    if (ni == NULL)
1005 		    {
1006 			if (!quiet)
1007 			    semsg(_(e_listidx), lp->ll_n2);
1008 			return NULL;
1009 		    }
1010 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
1011 		}
1012 
1013 		// Check that lp->ll_n2 isn't before lp->ll_n1.
1014 		if (lp->ll_n1 < 0)
1015 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
1016 		if (lp->ll_n2 < lp->ll_n1)
1017 		{
1018 		    if (!quiet)
1019 			semsg(_(e_listidx), lp->ll_n2);
1020 		    return NULL;
1021 		}
1022 	    }
1023 
1024 	    lp->ll_tv = &lp->ll_li->li_tv;
1025 	}
1026     }
1027 
1028     clear_tv(&var1);
1029     lp->ll_name_end = p;
1030     return p;
1031 }
1032 
1033 /*
1034  * Clear lval "lp" that was filled by get_lval().
1035  */
1036     void
1037 clear_lval(lval_T *lp)
1038 {
1039     vim_free(lp->ll_exp_name);
1040     vim_free(lp->ll_newkey);
1041 }
1042 
1043 /*
1044  * Set a variable that was parsed by get_lval() to "rettv".
1045  * "endp" points to just after the parsed name.
1046  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
1047  * "%" for "%=", "." for ".=" or "=" for "=".
1048  */
1049     void
1050 set_var_lval(
1051     lval_T	*lp,
1052     char_u	*endp,
1053     typval_T	*rettv,
1054     int		copy,
1055     int		flags,    // LET_IS_CONST and/or LET_NO_COMMAND
1056     char_u	*op)
1057 {
1058     int		cc;
1059     listitem_T	*ri;
1060     dictitem_T	*di;
1061 
1062     if (lp->ll_tv == NULL)
1063     {
1064 	cc = *endp;
1065 	*endp = NUL;
1066 	if (lp->ll_blob != NULL)
1067 	{
1068 	    int	    error = FALSE, val;
1069 
1070 	    if (op != NULL && *op != '=')
1071 	    {
1072 		semsg(_(e_letwrong), op);
1073 		return;
1074 	    }
1075 
1076 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
1077 	    {
1078 		int	il, ir;
1079 
1080 		if (lp->ll_empty2)
1081 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
1082 
1083 		if (lp->ll_n2 - lp->ll_n1 + 1 != blob_len(rettv->vval.v_blob))
1084 		{
1085 		    emsg(_("E972: Blob value does not have the right number of bytes"));
1086 		    return;
1087 		}
1088 		if (lp->ll_empty2)
1089 		    lp->ll_n2 = blob_len(lp->ll_blob);
1090 
1091 		ir = 0;
1092 		for (il = lp->ll_n1; il <= lp->ll_n2; il++)
1093 		    blob_set(lp->ll_blob, il,
1094 			    blob_get(rettv->vval.v_blob, ir++));
1095 	    }
1096 	    else
1097 	    {
1098 		val = (int)tv_get_number_chk(rettv, &error);
1099 		if (!error)
1100 		{
1101 		    garray_T *gap = &lp->ll_blob->bv_ga;
1102 
1103 		    // Allow for appending a byte.  Setting a byte beyond
1104 		    // the end is an error otherwise.
1105 		    if (lp->ll_n1 < gap->ga_len
1106 			    || (lp->ll_n1 == gap->ga_len
1107 				&& ga_grow(&lp->ll_blob->bv_ga, 1) == OK))
1108 		    {
1109 			blob_set(lp->ll_blob, lp->ll_n1, val);
1110 			if (lp->ll_n1 == gap->ga_len)
1111 			    ++gap->ga_len;
1112 		    }
1113 		    // error for invalid range was already given in get_lval()
1114 		}
1115 	    }
1116 	}
1117 	else if (op != NULL && *op != '=')
1118 	{
1119 	    typval_T tv;
1120 
1121 	    if (flags & LET_IS_CONST)
1122 	    {
1123 		emsg(_(e_cannot_mod));
1124 		*endp = cc;
1125 		return;
1126 	    }
1127 
1128 	    // handle +=, -=, *=, /=, %= and .=
1129 	    di = NULL;
1130 	    if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
1131 					     &tv, &di, TRUE, FALSE) == OK)
1132 	    {
1133 		if ((di == NULL
1134 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
1135 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
1136 			&& tv_op(&tv, rettv, op) == OK)
1137 		    set_var(lp->ll_name, &tv, FALSE);
1138 		clear_tv(&tv);
1139 	    }
1140 	}
1141 	else
1142 	    set_var_const(lp->ll_name, lp->ll_type, rettv, copy, flags);
1143 	*endp = cc;
1144     }
1145     else if (var_check_lock(lp->ll_newkey == NULL
1146 		? lp->ll_tv->v_lock
1147 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
1148 	;
1149     else if (lp->ll_range)
1150     {
1151 	listitem_T *ll_li = lp->ll_li;
1152 	int	    ll_n1 = lp->ll_n1;
1153 
1154 	if (flags & LET_IS_CONST)
1155 	{
1156 	    emsg(_("E996: Cannot lock a range"));
1157 	    return;
1158 	}
1159 
1160 	/*
1161 	 * Check whether any of the list items is locked
1162 	 */
1163 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
1164 	{
1165 	    if (var_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
1166 		return;
1167 	    ri = ri->li_next;
1168 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
1169 		break;
1170 	    ll_li = ll_li->li_next;
1171 	    ++ll_n1;
1172 	}
1173 
1174 	/*
1175 	 * Assign the List values to the list items.
1176 	 */
1177 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
1178 	{
1179 	    if (op != NULL && *op != '=')
1180 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
1181 	    else
1182 	    {
1183 		clear_tv(&lp->ll_li->li_tv);
1184 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
1185 	    }
1186 	    ri = ri->li_next;
1187 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
1188 		break;
1189 	    if (lp->ll_li->li_next == NULL)
1190 	    {
1191 		// Need to add an empty item.
1192 		if (list_append_number(lp->ll_list, 0) == FAIL)
1193 		{
1194 		    ri = NULL;
1195 		    break;
1196 		}
1197 	    }
1198 	    lp->ll_li = lp->ll_li->li_next;
1199 	    ++lp->ll_n1;
1200 	}
1201 	if (ri != NULL)
1202 	    emsg(_("E710: List value has more items than target"));
1203 	else if (lp->ll_empty2
1204 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
1205 		: lp->ll_n1 != lp->ll_n2)
1206 	    emsg(_("E711: List value has not enough items"));
1207     }
1208     else
1209     {
1210 	/*
1211 	 * Assign to a List or Dictionary item.
1212 	 */
1213 	if (flags & LET_IS_CONST)
1214 	{
1215 	    emsg(_("E996: Cannot lock a list or dict"));
1216 	    return;
1217 	}
1218 	if (lp->ll_newkey != NULL)
1219 	{
1220 	    if (op != NULL && *op != '=')
1221 	    {
1222 		semsg(_(e_letwrong), op);
1223 		return;
1224 	    }
1225 
1226 	    // Need to add an item to the Dictionary.
1227 	    di = dictitem_alloc(lp->ll_newkey);
1228 	    if (di == NULL)
1229 		return;
1230 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
1231 	    {
1232 		vim_free(di);
1233 		return;
1234 	    }
1235 	    lp->ll_tv = &di->di_tv;
1236 	}
1237 	else if (op != NULL && *op != '=')
1238 	{
1239 	    tv_op(lp->ll_tv, rettv, op);
1240 	    return;
1241 	}
1242 	else
1243 	    clear_tv(lp->ll_tv);
1244 
1245 	/*
1246 	 * Assign the value to the variable or list item.
1247 	 */
1248 	if (copy)
1249 	    copy_tv(rettv, lp->ll_tv);
1250 	else
1251 	{
1252 	    *lp->ll_tv = *rettv;
1253 	    lp->ll_tv->v_lock = 0;
1254 	    init_tv(rettv);
1255 	}
1256     }
1257 }
1258 
1259 /*
1260  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
1261  * and "tv1 .= tv2"
1262  * Returns OK or FAIL.
1263  */
1264     static int
1265 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
1266 {
1267     varnumber_T	n;
1268     char_u	numbuf[NUMBUFLEN];
1269     char_u	*s;
1270 
1271     // Can't do anything with a Funcref, Dict, v:true on the right.
1272     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
1273 		      && tv2->v_type != VAR_BOOL && tv2->v_type != VAR_SPECIAL)
1274     {
1275 	switch (tv1->v_type)
1276 	{
1277 	    case VAR_UNKNOWN:
1278 	    case VAR_ANY:
1279 	    case VAR_VOID:
1280 	    case VAR_DICT:
1281 	    case VAR_FUNC:
1282 	    case VAR_PARTIAL:
1283 	    case VAR_BOOL:
1284 	    case VAR_SPECIAL:
1285 	    case VAR_JOB:
1286 	    case VAR_CHANNEL:
1287 		break;
1288 
1289 	    case VAR_BLOB:
1290 		if (*op != '+' || tv2->v_type != VAR_BLOB)
1291 		    break;
1292 		// BLOB += BLOB
1293 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
1294 		{
1295 		    blob_T  *b1 = tv1->vval.v_blob;
1296 		    blob_T  *b2 = tv2->vval.v_blob;
1297 		    int	i, len = blob_len(b2);
1298 		    for (i = 0; i < len; i++)
1299 			ga_append(&b1->bv_ga, blob_get(b2, i));
1300 		}
1301 		return OK;
1302 
1303 	    case VAR_LIST:
1304 		if (*op != '+' || tv2->v_type != VAR_LIST)
1305 		    break;
1306 		// List += List
1307 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
1308 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
1309 		return OK;
1310 
1311 	    case VAR_NUMBER:
1312 	    case VAR_STRING:
1313 		if (tv2->v_type == VAR_LIST)
1314 		    break;
1315 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
1316 		{
1317 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
1318 		    n = tv_get_number(tv1);
1319 #ifdef FEAT_FLOAT
1320 		    if (tv2->v_type == VAR_FLOAT)
1321 		    {
1322 			float_T f = n;
1323 
1324 			if (*op == '%')
1325 			    break;
1326 			switch (*op)
1327 			{
1328 			    case '+': f += tv2->vval.v_float; break;
1329 			    case '-': f -= tv2->vval.v_float; break;
1330 			    case '*': f *= tv2->vval.v_float; break;
1331 			    case '/': f /= tv2->vval.v_float; break;
1332 			}
1333 			clear_tv(tv1);
1334 			tv1->v_type = VAR_FLOAT;
1335 			tv1->vval.v_float = f;
1336 		    }
1337 		    else
1338 #endif
1339 		    {
1340 			switch (*op)
1341 			{
1342 			    case '+': n += tv_get_number(tv2); break;
1343 			    case '-': n -= tv_get_number(tv2); break;
1344 			    case '*': n *= tv_get_number(tv2); break;
1345 			    case '/': n = num_divide(n, tv_get_number(tv2)); break;
1346 			    case '%': n = num_modulus(n, tv_get_number(tv2)); break;
1347 			}
1348 			clear_tv(tv1);
1349 			tv1->v_type = VAR_NUMBER;
1350 			tv1->vval.v_number = n;
1351 		    }
1352 		}
1353 		else
1354 		{
1355 		    if (tv2->v_type == VAR_FLOAT)
1356 			break;
1357 
1358 		    // str .= str
1359 		    s = tv_get_string(tv1);
1360 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
1361 		    clear_tv(tv1);
1362 		    tv1->v_type = VAR_STRING;
1363 		    tv1->vval.v_string = s;
1364 		}
1365 		return OK;
1366 
1367 	    case VAR_FLOAT:
1368 #ifdef FEAT_FLOAT
1369 		{
1370 		    float_T f;
1371 
1372 		    if (*op == '%' || *op == '.'
1373 				   || (tv2->v_type != VAR_FLOAT
1374 				    && tv2->v_type != VAR_NUMBER
1375 				    && tv2->v_type != VAR_STRING))
1376 			break;
1377 		    if (tv2->v_type == VAR_FLOAT)
1378 			f = tv2->vval.v_float;
1379 		    else
1380 			f = tv_get_number(tv2);
1381 		    switch (*op)
1382 		    {
1383 			case '+': tv1->vval.v_float += f; break;
1384 			case '-': tv1->vval.v_float -= f; break;
1385 			case '*': tv1->vval.v_float *= f; break;
1386 			case '/': tv1->vval.v_float /= f; break;
1387 		    }
1388 		}
1389 #endif
1390 		return OK;
1391 	}
1392     }
1393 
1394     semsg(_(e_letwrong), op);
1395     return FAIL;
1396 }
1397 
1398 /*
1399  * Evaluate the expression used in a ":for var in expr" command.
1400  * "arg" points to "var".
1401  * Set "*errp" to TRUE for an error, FALSE otherwise;
1402  * Return a pointer that holds the info.  Null when there is an error.
1403  */
1404     void *
1405 eval_for_line(
1406     char_u	*arg,
1407     int		*errp,
1408     char_u	**nextcmdp,
1409     int		skip)
1410 {
1411     forinfo_T	*fi;
1412     char_u	*expr;
1413     typval_T	tv;
1414     list_T	*l;
1415 
1416     *errp = TRUE;	// default: there is an error
1417 
1418     fi = ALLOC_CLEAR_ONE(forinfo_T);
1419     if (fi == NULL)
1420 	return NULL;
1421 
1422     expr = skip_var_list(arg, TRUE, &fi->fi_varcount, &fi->fi_semicolon);
1423     if (expr == NULL)
1424 	return fi;
1425 
1426     expr = skipwhite(expr);
1427     if (expr[0] != 'i' || expr[1] != 'n' || !VIM_ISWHITE(expr[2]))
1428     {
1429 	emsg(_(e_missing_in));
1430 	return fi;
1431     }
1432 
1433     if (skip)
1434 	++emsg_skip;
1435     if (eval0(skipwhite(expr + 2), &tv, nextcmdp, !skip) == OK)
1436     {
1437 	*errp = FALSE;
1438 	if (!skip)
1439 	{
1440 	    if (tv.v_type == VAR_LIST)
1441 	    {
1442 		l = tv.vval.v_list;
1443 		if (l == NULL)
1444 		{
1445 		    // a null list is like an empty list: do nothing
1446 		    clear_tv(&tv);
1447 		}
1448 		else
1449 		{
1450 		    // Need a real list here.
1451 		    range_list_materialize(l);
1452 
1453 		    // No need to increment the refcount, it's already set for
1454 		    // the list being used in "tv".
1455 		    fi->fi_list = l;
1456 		    list_add_watch(l, &fi->fi_lw);
1457 		    fi->fi_lw.lw_item = l->lv_first;
1458 		}
1459 	    }
1460 	    else if (tv.v_type == VAR_BLOB)
1461 	    {
1462 		fi->fi_bi = 0;
1463 		if (tv.vval.v_blob != NULL)
1464 		{
1465 		    typval_T btv;
1466 
1467 		    // Make a copy, so that the iteration still works when the
1468 		    // blob is changed.
1469 		    blob_copy(tv.vval.v_blob, &btv);
1470 		    fi->fi_blob = btv.vval.v_blob;
1471 		}
1472 		clear_tv(&tv);
1473 	    }
1474 	    else
1475 	    {
1476 		emsg(_(e_listreq));
1477 		clear_tv(&tv);
1478 	    }
1479 	}
1480     }
1481     if (skip)
1482 	--emsg_skip;
1483 
1484     return fi;
1485 }
1486 
1487 /*
1488  * Use the first item in a ":for" list.  Advance to the next.
1489  * Assign the values to the variable (list).  "arg" points to the first one.
1490  * Return TRUE when a valid item was found, FALSE when at end of list or
1491  * something wrong.
1492  */
1493     int
1494 next_for_item(void *fi_void, char_u *arg)
1495 {
1496     forinfo_T	*fi = (forinfo_T *)fi_void;
1497     int		result;
1498     int		flag = current_sctx.sc_version == SCRIPT_VERSION_VIM9 ?
1499 							LET_NO_COMMAND : 0;
1500     listitem_T	*item;
1501 
1502     if (fi->fi_blob != NULL)
1503     {
1504 	typval_T	tv;
1505 
1506 	if (fi->fi_bi >= blob_len(fi->fi_blob))
1507 	    return FALSE;
1508 	tv.v_type = VAR_NUMBER;
1509 	tv.v_lock = VAR_FIXED;
1510 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
1511 	++fi->fi_bi;
1512 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1513 				       fi->fi_varcount, flag, NULL) == OK;
1514     }
1515 
1516     item = fi->fi_lw.lw_item;
1517     if (item == NULL)
1518 	result = FALSE;
1519     else
1520     {
1521 	fi->fi_lw.lw_item = item->li_next;
1522 	result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
1523 				      fi->fi_varcount, flag, NULL) == OK);
1524     }
1525     return result;
1526 }
1527 
1528 /*
1529  * Free the structure used to store info used by ":for".
1530  */
1531     void
1532 free_for_info(void *fi_void)
1533 {
1534     forinfo_T    *fi = (forinfo_T *)fi_void;
1535 
1536     if (fi != NULL && fi->fi_list != NULL)
1537     {
1538 	list_rem_watch(fi->fi_list, &fi->fi_lw);
1539 	list_unref(fi->fi_list);
1540     }
1541     if (fi != NULL && fi->fi_blob != NULL)
1542 	blob_unref(fi->fi_blob);
1543     vim_free(fi);
1544 }
1545 
1546     void
1547 set_context_for_expression(
1548     expand_T	*xp,
1549     char_u	*arg,
1550     cmdidx_T	cmdidx)
1551 {
1552     int		got_eq = FALSE;
1553     int		c;
1554     char_u	*p;
1555 
1556     if (cmdidx == CMD_let || cmdidx == CMD_const)
1557     {
1558 	xp->xp_context = EXPAND_USER_VARS;
1559 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
1560 	{
1561 	    // ":let var1 var2 ...": find last space.
1562 	    for (p = arg + STRLEN(arg); p >= arg; )
1563 	    {
1564 		xp->xp_pattern = p;
1565 		MB_PTR_BACK(arg, p);
1566 		if (VIM_ISWHITE(*p))
1567 		    break;
1568 	    }
1569 	    return;
1570 	}
1571     }
1572     else
1573 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
1574 							  : EXPAND_EXPRESSION;
1575     while ((xp->xp_pattern = vim_strpbrk(arg,
1576 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
1577     {
1578 	c = *xp->xp_pattern;
1579 	if (c == '&')
1580 	{
1581 	    c = xp->xp_pattern[1];
1582 	    if (c == '&')
1583 	    {
1584 		++xp->xp_pattern;
1585 		xp->xp_context = cmdidx != CMD_let || got_eq
1586 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
1587 	    }
1588 	    else if (c != ' ')
1589 	    {
1590 		xp->xp_context = EXPAND_SETTINGS;
1591 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
1592 		    xp->xp_pattern += 2;
1593 
1594 	    }
1595 	}
1596 	else if (c == '$')
1597 	{
1598 	    // environment variable
1599 	    xp->xp_context = EXPAND_ENV_VARS;
1600 	}
1601 	else if (c == '=')
1602 	{
1603 	    got_eq = TRUE;
1604 	    xp->xp_context = EXPAND_EXPRESSION;
1605 	}
1606 	else if (c == '#'
1607 		&& xp->xp_context == EXPAND_EXPRESSION)
1608 	{
1609 	    // Autoload function/variable contains '#'.
1610 	    break;
1611 	}
1612 	else if ((c == '<' || c == '#')
1613 		&& xp->xp_context == EXPAND_FUNCTIONS
1614 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
1615 	{
1616 	    // Function name can start with "<SNR>" and contain '#'.
1617 	    break;
1618 	}
1619 	else if (cmdidx != CMD_let || got_eq)
1620 	{
1621 	    if (c == '"')	    // string
1622 	    {
1623 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
1624 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
1625 			++xp->xp_pattern;
1626 		xp->xp_context = EXPAND_NOTHING;
1627 	    }
1628 	    else if (c == '\'')	    // literal string
1629 	    {
1630 		// Trick: '' is like stopping and starting a literal string.
1631 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
1632 		    /* skip */ ;
1633 		xp->xp_context = EXPAND_NOTHING;
1634 	    }
1635 	    else if (c == '|')
1636 	    {
1637 		if (xp->xp_pattern[1] == '|')
1638 		{
1639 		    ++xp->xp_pattern;
1640 		    xp->xp_context = EXPAND_EXPRESSION;
1641 		}
1642 		else
1643 		    xp->xp_context = EXPAND_COMMANDS;
1644 	    }
1645 	    else
1646 		xp->xp_context = EXPAND_EXPRESSION;
1647 	}
1648 	else
1649 	    // Doesn't look like something valid, expand as an expression
1650 	    // anyway.
1651 	    xp->xp_context = EXPAND_EXPRESSION;
1652 	arg = xp->xp_pattern;
1653 	if (*arg != NUL)
1654 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
1655 		/* skip */ ;
1656     }
1657     xp->xp_pattern = arg;
1658 }
1659 
1660 /*
1661  * Return TRUE if "pat" matches "text".
1662  * Does not use 'cpo' and always uses 'magic'.
1663  */
1664     int
1665 pattern_match(char_u *pat, char_u *text, int ic)
1666 {
1667     int		matches = FALSE;
1668     char_u	*save_cpo;
1669     regmatch_T	regmatch;
1670 
1671     // avoid 'l' flag in 'cpoptions'
1672     save_cpo = p_cpo;
1673     p_cpo = (char_u *)"";
1674     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1675     if (regmatch.regprog != NULL)
1676     {
1677 	regmatch.rm_ic = ic;
1678 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
1679 	vim_regfree(regmatch.regprog);
1680     }
1681     p_cpo = save_cpo;
1682     return matches;
1683 }
1684 
1685 /*
1686  * Handle a name followed by "(".  Both for just "name(arg)" and for
1687  * "expr->name(arg)".
1688  * Returns OK or FAIL.
1689  */
1690     static int
1691 eval_func(
1692 	char_u	    **arg,	// points to "(", will be advanced
1693 	char_u	    *name,
1694 	int	    name_len,
1695 	typval_T    *rettv,
1696 	int	    evaluate,
1697 	typval_T    *basetv)	// "expr" for "expr->name(arg)"
1698 {
1699     char_u	*s = name;
1700     int		len = name_len;
1701     partial_T	*partial;
1702     int		ret = OK;
1703 
1704     if (!evaluate)
1705 	check_vars(s, len);
1706 
1707     // If "s" is the name of a variable of type VAR_FUNC
1708     // use its contents.
1709     s = deref_func_name(s, &len, &partial, !evaluate);
1710 
1711     // Need to make a copy, in case evaluating the arguments makes
1712     // the name invalid.
1713     s = vim_strsave(s);
1714     if (s == NULL)
1715 	ret = FAIL;
1716     else
1717     {
1718 	funcexe_T funcexe;
1719 
1720 	// Invoke the function.
1721 	CLEAR_FIELD(funcexe);
1722 	funcexe.firstline = curwin->w_cursor.lnum;
1723 	funcexe.lastline = curwin->w_cursor.lnum;
1724 	funcexe.evaluate = evaluate;
1725 	funcexe.partial = partial;
1726 	funcexe.basetv = basetv;
1727 	ret = get_func_tv(s, len, rettv, arg, &funcexe);
1728     }
1729     vim_free(s);
1730 
1731     // If evaluate is FALSE rettv->v_type was not set in
1732     // get_func_tv, but it's needed in handle_subscript() to parse
1733     // what follows. So set it here.
1734     if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
1735     {
1736 	rettv->vval.v_string = NULL;
1737 	rettv->v_type = VAR_FUNC;
1738     }
1739 
1740     // Stop the expression evaluation when immediately
1741     // aborting on error, or when an interrupt occurred or
1742     // an exception was thrown but not caught.
1743     if (evaluate && aborting())
1744     {
1745 	if (ret == OK)
1746 	    clear_tv(rettv);
1747 	ret = FAIL;
1748     }
1749     return ret;
1750 }
1751 
1752 /*
1753  * The "evaluate" argument: When FALSE, the argument is only parsed but not
1754  * executed.  The function may return OK, but the rettv will be of type
1755  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
1756  */
1757 
1758 /*
1759  * Handle zero level expression.
1760  * This calls eval1() and handles error message and nextcmd.
1761  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
1762  * Note: "rettv.v_lock" is not set.
1763  * Return OK or FAIL.
1764  */
1765     int
1766 eval0(
1767     char_u	*arg,
1768     typval_T	*rettv,
1769     char_u	**nextcmd,
1770     int		evaluate)
1771 {
1772     int		ret;
1773     char_u	*p;
1774     int		did_emsg_before = did_emsg;
1775     int		called_emsg_before = called_emsg;
1776 
1777     p = skipwhite(arg);
1778     ret = eval1(&p, rettv, evaluate);
1779     if (ret == FAIL || !ends_excmd2(arg, p))
1780     {
1781 	if (ret != FAIL)
1782 	    clear_tv(rettv);
1783 	/*
1784 	 * Report the invalid expression unless the expression evaluation has
1785 	 * been cancelled due to an aborting error, an interrupt, or an
1786 	 * exception, or we already gave a more specific error.
1787 	 * Also check called_emsg for when using assert_fails().
1788 	 */
1789 	if (!aborting() && did_emsg == did_emsg_before
1790 					  && called_emsg == called_emsg_before)
1791 	    semsg(_(e_invexpr2), arg);
1792 	ret = FAIL;
1793     }
1794     if (nextcmd != NULL)
1795 	*nextcmd = check_nextcmd(p);
1796 
1797     return ret;
1798 }
1799 
1800 /*
1801  * Handle top level expression:
1802  *	expr2 ? expr1 : expr1
1803  *
1804  * "arg" must point to the first non-white of the expression.
1805  * "arg" is advanced to the next non-white after the recognized expression.
1806  *
1807  * Note: "rettv.v_lock" is not set.
1808  *
1809  * Return OK or FAIL.
1810  */
1811     int
1812 eval1(char_u **arg, typval_T *rettv, int evaluate)
1813 {
1814     int		result;
1815     typval_T	var2;
1816 
1817     /*
1818      * Get the first variable.
1819      */
1820     if (eval2(arg, rettv, evaluate) == FAIL)
1821 	return FAIL;
1822 
1823     if ((*arg)[0] == '?')
1824     {
1825 	result = FALSE;
1826 	if (evaluate)
1827 	{
1828 	    int		error = FALSE;
1829 
1830 	    if (tv_get_number_chk(rettv, &error) != 0)
1831 		result = TRUE;
1832 	    clear_tv(rettv);
1833 	    if (error)
1834 		return FAIL;
1835 	}
1836 
1837 	/*
1838 	 * Get the second variable.
1839 	 */
1840 	*arg = skipwhite(*arg + 1);
1841 	if (eval1(arg, rettv, evaluate && result) == FAIL) // recursive!
1842 	    return FAIL;
1843 
1844 	/*
1845 	 * Check for the ":".
1846 	 */
1847 	if ((*arg)[0] != ':')
1848 	{
1849 	    emsg(_(e_missing_colon));
1850 	    if (evaluate && result)
1851 		clear_tv(rettv);
1852 	    return FAIL;
1853 	}
1854 
1855 	/*
1856 	 * Get the third variable.
1857 	 */
1858 	*arg = skipwhite(*arg + 1);
1859 	if (eval1(arg, &var2, evaluate && !result) == FAIL) // recursive!
1860 	{
1861 	    if (evaluate && result)
1862 		clear_tv(rettv);
1863 	    return FAIL;
1864 	}
1865 	if (evaluate && !result)
1866 	    *rettv = var2;
1867     }
1868 
1869     return OK;
1870 }
1871 
1872 /*
1873  * Handle first level expression:
1874  *	expr2 || expr2 || expr2	    logical OR
1875  *
1876  * "arg" must point to the first non-white of the expression.
1877  * "arg" is advanced to the next non-white after the recognized expression.
1878  *
1879  * Return OK or FAIL.
1880  */
1881     static int
1882 eval2(char_u **arg, typval_T *rettv, int evaluate)
1883 {
1884     typval_T	var2;
1885     long	result;
1886     int		first;
1887     int		error = FALSE;
1888 
1889     /*
1890      * Get the first variable.
1891      */
1892     if (eval3(arg, rettv, evaluate) == FAIL)
1893 	return FAIL;
1894 
1895     /*
1896      * Repeat until there is no following "||".
1897      */
1898     first = TRUE;
1899     result = FALSE;
1900     while ((*arg)[0] == '|' && (*arg)[1] == '|')
1901     {
1902 	if (evaluate && first)
1903 	{
1904 	    if (tv_get_number_chk(rettv, &error) != 0)
1905 		result = TRUE;
1906 	    clear_tv(rettv);
1907 	    if (error)
1908 		return FAIL;
1909 	    first = FALSE;
1910 	}
1911 
1912 	/*
1913 	 * Get the second variable.
1914 	 */
1915 	*arg = skipwhite(*arg + 2);
1916 	if (eval3(arg, &var2, evaluate && !result) == FAIL)
1917 	    return FAIL;
1918 
1919 	/*
1920 	 * Compute the result.
1921 	 */
1922 	if (evaluate && !result)
1923 	{
1924 	    if (tv_get_number_chk(&var2, &error) != 0)
1925 		result = TRUE;
1926 	    clear_tv(&var2);
1927 	    if (error)
1928 		return FAIL;
1929 	}
1930 	if (evaluate)
1931 	{
1932 	    rettv->v_type = VAR_NUMBER;
1933 	    rettv->vval.v_number = result;
1934 	}
1935     }
1936 
1937     return OK;
1938 }
1939 
1940 /*
1941  * Handle second level expression:
1942  *	expr3 && expr3 && expr3	    logical AND
1943  *
1944  * "arg" must point to the first non-white of the expression.
1945  * "arg" is advanced to the next non-white after the recognized expression.
1946  *
1947  * Return OK or FAIL.
1948  */
1949     static int
1950 eval3(char_u **arg, typval_T *rettv, int evaluate)
1951 {
1952     typval_T	var2;
1953     long	result;
1954     int		first;
1955     int		error = FALSE;
1956 
1957     /*
1958      * Get the first variable.
1959      */
1960     if (eval4(arg, rettv, evaluate) == FAIL)
1961 	return FAIL;
1962 
1963     /*
1964      * Repeat until there is no following "&&".
1965      */
1966     first = TRUE;
1967     result = TRUE;
1968     while ((*arg)[0] == '&' && (*arg)[1] == '&')
1969     {
1970 	if (evaluate && first)
1971 	{
1972 	    if (tv_get_number_chk(rettv, &error) == 0)
1973 		result = FALSE;
1974 	    clear_tv(rettv);
1975 	    if (error)
1976 		return FAIL;
1977 	    first = FALSE;
1978 	}
1979 
1980 	/*
1981 	 * Get the second variable.
1982 	 */
1983 	*arg = skipwhite(*arg + 2);
1984 	if (eval4(arg, &var2, evaluate && result) == FAIL)
1985 	    return FAIL;
1986 
1987 	/*
1988 	 * Compute the result.
1989 	 */
1990 	if (evaluate && result)
1991 	{
1992 	    if (tv_get_number_chk(&var2, &error) == 0)
1993 		result = FALSE;
1994 	    clear_tv(&var2);
1995 	    if (error)
1996 		return FAIL;
1997 	}
1998 	if (evaluate)
1999 	{
2000 	    rettv->v_type = VAR_NUMBER;
2001 	    rettv->vval.v_number = result;
2002 	}
2003     }
2004 
2005     return OK;
2006 }
2007 
2008 /*
2009  * Handle third level expression:
2010  *	var1 == var2
2011  *	var1 =~ var2
2012  *	var1 != var2
2013  *	var1 !~ var2
2014  *	var1 > var2
2015  *	var1 >= var2
2016  *	var1 < var2
2017  *	var1 <= var2
2018  *	var1 is var2
2019  *	var1 isnot var2
2020  *
2021  * "arg" must point to the first non-white of the expression.
2022  * "arg" is advanced to the next non-white after the recognized expression.
2023  *
2024  * Return OK or FAIL.
2025  */
2026     static int
2027 eval4(char_u **arg, typval_T *rettv, int evaluate)
2028 {
2029     typval_T	var2;
2030     char_u	*p;
2031     int		i;
2032     exptype_T	type = EXPR_UNKNOWN;
2033     int		len = 2;
2034     int		ic;
2035 
2036     /*
2037      * Get the first variable.
2038      */
2039     if (eval5(arg, rettv, evaluate) == FAIL)
2040 	return FAIL;
2041 
2042     p = *arg;
2043     switch (p[0])
2044     {
2045 	case '=':   if (p[1] == '=')
2046 			type = EXPR_EQUAL;
2047 		    else if (p[1] == '~')
2048 			type = EXPR_MATCH;
2049 		    break;
2050 	case '!':   if (p[1] == '=')
2051 			type = EXPR_NEQUAL;
2052 		    else if (p[1] == '~')
2053 			type = EXPR_NOMATCH;
2054 		    break;
2055 	case '>':   if (p[1] != '=')
2056 		    {
2057 			type = EXPR_GREATER;
2058 			len = 1;
2059 		    }
2060 		    else
2061 			type = EXPR_GEQUAL;
2062 		    break;
2063 	case '<':   if (p[1] != '=')
2064 		    {
2065 			type = EXPR_SMALLER;
2066 			len = 1;
2067 		    }
2068 		    else
2069 			type = EXPR_SEQUAL;
2070 		    break;
2071 	case 'i':   if (p[1] == 's')
2072 		    {
2073 			if (p[2] == 'n' && p[3] == 'o' && p[4] == 't')
2074 			    len = 5;
2075 			i = p[len];
2076 			if (!isalnum(i) && i != '_')
2077 			    type = len == 2 ? EXPR_IS : EXPR_ISNOT;
2078 		    }
2079 		    break;
2080     }
2081 
2082     /*
2083      * If there is a comparative operator, use it.
2084      */
2085     if (type != EXPR_UNKNOWN)
2086     {
2087 	// extra question mark appended: ignore case
2088 	if (p[len] == '?')
2089 	{
2090 	    ic = TRUE;
2091 	    ++len;
2092 	}
2093 	// extra '#' appended: match case
2094 	else if (p[len] == '#')
2095 	{
2096 	    ic = FALSE;
2097 	    ++len;
2098 	}
2099 	// nothing appended: use 'ignorecase'
2100 	else
2101 	    ic = p_ic;
2102 
2103 	/*
2104 	 * Get the second variable.
2105 	 */
2106 	*arg = skipwhite(p + len);
2107 	if (eval5(arg, &var2, evaluate) == FAIL)
2108 	{
2109 	    clear_tv(rettv);
2110 	    return FAIL;
2111 	}
2112 	if (evaluate)
2113 	{
2114 	    int ret = typval_compare(rettv, &var2, type, ic);
2115 
2116 	    clear_tv(&var2);
2117 	    return ret;
2118 	}
2119     }
2120 
2121     return OK;
2122 }
2123 
2124     void
2125 eval_addblob(typval_T *tv1, typval_T *tv2)
2126 {
2127     blob_T  *b1 = tv1->vval.v_blob;
2128     blob_T  *b2 = tv2->vval.v_blob;
2129     blob_T  *b = blob_alloc();
2130     int	    i;
2131 
2132     if (b != NULL)
2133     {
2134 	for (i = 0; i < blob_len(b1); i++)
2135 	    ga_append(&b->bv_ga, blob_get(b1, i));
2136 	for (i = 0; i < blob_len(b2); i++)
2137 	    ga_append(&b->bv_ga, blob_get(b2, i));
2138 
2139 	clear_tv(tv1);
2140 	rettv_blob_set(tv1, b);
2141     }
2142 }
2143 
2144     int
2145 eval_addlist(typval_T *tv1, typval_T *tv2)
2146 {
2147     typval_T var3;
2148 
2149     // concatenate Lists
2150     if (list_concat(tv1->vval.v_list, tv2->vval.v_list, &var3) == FAIL)
2151     {
2152 	clear_tv(tv1);
2153 	clear_tv(tv2);
2154 	return FAIL;
2155     }
2156     clear_tv(tv1);
2157     *tv1 = var3;
2158     return OK;
2159 }
2160 
2161 /*
2162  * Handle fourth level expression:
2163  *	+	number addition
2164  *	-	number subtraction
2165  *	.	string concatenation (if script version is 1)
2166  *	..	string concatenation
2167  *
2168  * "arg" must point to the first non-white of the expression.
2169  * "arg" is advanced to the next non-white after the recognized expression.
2170  *
2171  * Return OK or FAIL.
2172  */
2173     static int
2174 eval5(char_u **arg, typval_T *rettv, int evaluate)
2175 {
2176     typval_T	var2;
2177     int		op;
2178     varnumber_T	n1, n2;
2179 #ifdef FEAT_FLOAT
2180     float_T	f1 = 0, f2 = 0;
2181 #endif
2182     char_u	*s1, *s2;
2183     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
2184     char_u	*p;
2185     int		concat;
2186 
2187     /*
2188      * Get the first variable.
2189      */
2190     if (eval6(arg, rettv, evaluate, FALSE) == FAIL)
2191 	return FAIL;
2192 
2193     /*
2194      * Repeat computing, until no '+', '-' or '.' is following.
2195      */
2196     for (;;)
2197     {
2198 	// "." is only string concatenation when scriptversion is 1
2199 	op = **arg;
2200 	concat = op == '.'
2201 			&& (*(*arg + 1) == '.' || current_sctx.sc_version < 2);
2202 	if (op != '+' && op != '-' && !concat)
2203 	    break;
2204 
2205 	if ((op != '+' || (rettv->v_type != VAR_LIST
2206 						 && rettv->v_type != VAR_BLOB))
2207 #ifdef FEAT_FLOAT
2208 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2209 #endif
2210 		)
2211 	{
2212 	    // For "list + ...", an illegal use of the first operand as
2213 	    // a number cannot be determined before evaluating the 2nd
2214 	    // operand: if this is also a list, all is ok.
2215 	    // For "something . ...", "something - ..." or "non-list + ...",
2216 	    // we know that the first operand needs to be a string or number
2217 	    // without evaluating the 2nd operand.  So check before to avoid
2218 	    // side effects after an error.
2219 	    if (evaluate && tv_get_string_chk(rettv) == NULL)
2220 	    {
2221 		clear_tv(rettv);
2222 		return FAIL;
2223 	    }
2224 	}
2225 
2226 	/*
2227 	 * Get the second variable.
2228 	 */
2229 	if (op == '.' && *(*arg + 1) == '.')  // .. string concatenation
2230 	    ++*arg;
2231 	*arg = skipwhite(*arg + 1);
2232 	if (eval6(arg, &var2, evaluate, op == '.') == FAIL)
2233 	{
2234 	    clear_tv(rettv);
2235 	    return FAIL;
2236 	}
2237 
2238 	if (evaluate)
2239 	{
2240 	    /*
2241 	     * Compute the result.
2242 	     */
2243 	    if (op == '.')
2244 	    {
2245 		s1 = tv_get_string_buf(rettv, buf1);	// already checked
2246 		s2 = tv_get_string_buf_chk(&var2, buf2);
2247 		if (s2 == NULL)		// type error ?
2248 		{
2249 		    clear_tv(rettv);
2250 		    clear_tv(&var2);
2251 		    return FAIL;
2252 		}
2253 		p = concat_str(s1, s2);
2254 		clear_tv(rettv);
2255 		rettv->v_type = VAR_STRING;
2256 		rettv->vval.v_string = p;
2257 	    }
2258 	    else if (op == '+' && rettv->v_type == VAR_BLOB
2259 						   && var2.v_type == VAR_BLOB)
2260 		eval_addblob(rettv, &var2);
2261 	    else if (op == '+' && rettv->v_type == VAR_LIST
2262 						   && var2.v_type == VAR_LIST)
2263 	    {
2264 		if (eval_addlist(rettv, &var2) == FAIL)
2265 		    return FAIL;
2266 	    }
2267 	    else
2268 	    {
2269 		int	    error = FALSE;
2270 
2271 #ifdef FEAT_FLOAT
2272 		if (rettv->v_type == VAR_FLOAT)
2273 		{
2274 		    f1 = rettv->vval.v_float;
2275 		    n1 = 0;
2276 		}
2277 		else
2278 #endif
2279 		{
2280 		    n1 = tv_get_number_chk(rettv, &error);
2281 		    if (error)
2282 		    {
2283 			// This can only happen for "list + non-list".  For
2284 			// "non-list + ..." or "something - ...", we returned
2285 			// before evaluating the 2nd operand.
2286 			clear_tv(rettv);
2287 			return FAIL;
2288 		    }
2289 #ifdef FEAT_FLOAT
2290 		    if (var2.v_type == VAR_FLOAT)
2291 			f1 = n1;
2292 #endif
2293 		}
2294 #ifdef FEAT_FLOAT
2295 		if (var2.v_type == VAR_FLOAT)
2296 		{
2297 		    f2 = var2.vval.v_float;
2298 		    n2 = 0;
2299 		}
2300 		else
2301 #endif
2302 		{
2303 		    n2 = tv_get_number_chk(&var2, &error);
2304 		    if (error)
2305 		    {
2306 			clear_tv(rettv);
2307 			clear_tv(&var2);
2308 			return FAIL;
2309 		    }
2310 #ifdef FEAT_FLOAT
2311 		    if (rettv->v_type == VAR_FLOAT)
2312 			f2 = n2;
2313 #endif
2314 		}
2315 		clear_tv(rettv);
2316 
2317 #ifdef FEAT_FLOAT
2318 		// If there is a float on either side the result is a float.
2319 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
2320 		{
2321 		    if (op == '+')
2322 			f1 = f1 + f2;
2323 		    else
2324 			f1 = f1 - f2;
2325 		    rettv->v_type = VAR_FLOAT;
2326 		    rettv->vval.v_float = f1;
2327 		}
2328 		else
2329 #endif
2330 		{
2331 		    if (op == '+')
2332 			n1 = n1 + n2;
2333 		    else
2334 			n1 = n1 - n2;
2335 		    rettv->v_type = VAR_NUMBER;
2336 		    rettv->vval.v_number = n1;
2337 		}
2338 	    }
2339 	    clear_tv(&var2);
2340 	}
2341     }
2342     return OK;
2343 }
2344 
2345 /*
2346  * Handle fifth level expression:
2347  *	*	number multiplication
2348  *	/	number division
2349  *	%	number modulo
2350  *
2351  * "arg" must point to the first non-white of the expression.
2352  * "arg" is advanced to the next non-white after the recognized expression.
2353  *
2354  * Return OK or FAIL.
2355  */
2356     static int
2357 eval6(
2358     char_u	**arg,
2359     typval_T	*rettv,
2360     int		evaluate,
2361     int		want_string)  // after "." operator
2362 {
2363     typval_T	var2;
2364     int		op;
2365     varnumber_T	n1, n2;
2366 #ifdef FEAT_FLOAT
2367     int		use_float = FALSE;
2368     float_T	f1 = 0, f2 = 0;
2369 #endif
2370     int		error = FALSE;
2371 
2372     /*
2373      * Get the first variable.
2374      */
2375     if (eval7(arg, rettv, evaluate, want_string) == FAIL)
2376 	return FAIL;
2377 
2378     /*
2379      * Repeat computing, until no '*', '/' or '%' is following.
2380      */
2381     for (;;)
2382     {
2383 	op = **arg;
2384 	if (op != '*' && op != '/' && op != '%')
2385 	    break;
2386 
2387 	if (evaluate)
2388 	{
2389 #ifdef FEAT_FLOAT
2390 	    if (rettv->v_type == VAR_FLOAT)
2391 	    {
2392 		f1 = rettv->vval.v_float;
2393 		use_float = TRUE;
2394 		n1 = 0;
2395 	    }
2396 	    else
2397 #endif
2398 		n1 = tv_get_number_chk(rettv, &error);
2399 	    clear_tv(rettv);
2400 	    if (error)
2401 		return FAIL;
2402 	}
2403 	else
2404 	    n1 = 0;
2405 
2406 	/*
2407 	 * Get the second variable.
2408 	 */
2409 	*arg = skipwhite(*arg + 1);
2410 	if (eval7(arg, &var2, evaluate, FALSE) == FAIL)
2411 	    return FAIL;
2412 
2413 	if (evaluate)
2414 	{
2415 #ifdef FEAT_FLOAT
2416 	    if (var2.v_type == VAR_FLOAT)
2417 	    {
2418 		if (!use_float)
2419 		{
2420 		    f1 = n1;
2421 		    use_float = TRUE;
2422 		}
2423 		f2 = var2.vval.v_float;
2424 		n2 = 0;
2425 	    }
2426 	    else
2427 #endif
2428 	    {
2429 		n2 = tv_get_number_chk(&var2, &error);
2430 		clear_tv(&var2);
2431 		if (error)
2432 		    return FAIL;
2433 #ifdef FEAT_FLOAT
2434 		if (use_float)
2435 		    f2 = n2;
2436 #endif
2437 	    }
2438 
2439 	    /*
2440 	     * Compute the result.
2441 	     * When either side is a float the result is a float.
2442 	     */
2443 #ifdef FEAT_FLOAT
2444 	    if (use_float)
2445 	    {
2446 		if (op == '*')
2447 		    f1 = f1 * f2;
2448 		else if (op == '/')
2449 		{
2450 # ifdef VMS
2451 		    // VMS crashes on divide by zero, work around it
2452 		    if (f2 == 0.0)
2453 		    {
2454 			if (f1 == 0)
2455 			    f1 = -1 * __F_FLT_MAX - 1L;   // similar to NaN
2456 			else if (f1 < 0)
2457 			    f1 = -1 * __F_FLT_MAX;
2458 			else
2459 			    f1 = __F_FLT_MAX;
2460 		    }
2461 		    else
2462 			f1 = f1 / f2;
2463 # else
2464 		    // We rely on the floating point library to handle divide
2465 		    // by zero to result in "inf" and not a crash.
2466 		    f1 = f1 / f2;
2467 # endif
2468 		}
2469 		else
2470 		{
2471 		    emsg(_(e_modulus));
2472 		    return FAIL;
2473 		}
2474 		rettv->v_type = VAR_FLOAT;
2475 		rettv->vval.v_float = f1;
2476 	    }
2477 	    else
2478 #endif
2479 	    {
2480 		if (op == '*')
2481 		    n1 = n1 * n2;
2482 		else if (op == '/')
2483 		    n1 = num_divide(n1, n2);
2484 		else
2485 		    n1 = num_modulus(n1, n2);
2486 
2487 		rettv->v_type = VAR_NUMBER;
2488 		rettv->vval.v_number = n1;
2489 	    }
2490 	}
2491     }
2492 
2493     return OK;
2494 }
2495 
2496 /*
2497  * Handle sixth level expression:
2498  *  number		number constant
2499  *  0zFFFFFFFF		Blob constant
2500  *  "string"		string constant
2501  *  'string'		literal string constant
2502  *  &option-name	option value
2503  *  @r			register contents
2504  *  identifier		variable value
2505  *  function()		function call
2506  *  $VAR		environment variable
2507  *  (expression)	nested expression
2508  *  [expr, expr]	List
2509  *  {arg, arg -> expr}	Lambda
2510  *  {key: val, key: val}   Dictionary
2511  *  #{key: val, key: val}  Dictionary with literal keys
2512  *
2513  *  Also handle:
2514  *  ! in front		logical NOT
2515  *  - in front		unary minus
2516  *  + in front		unary plus (ignored)
2517  *  trailing []		subscript in String or List
2518  *  trailing .name	entry in Dictionary
2519  *  trailing ->name()	method call
2520  *
2521  * "arg" must point to the first non-white of the expression.
2522  * "arg" is advanced to the next non-white after the recognized expression.
2523  *
2524  * Return OK or FAIL.
2525  */
2526     static int
2527 eval7(
2528     char_u	**arg,
2529     typval_T	*rettv,
2530     int		evaluate,
2531     int		want_string)	// after "." operator
2532 {
2533     int		len;
2534     char_u	*s;
2535     char_u	*start_leader, *end_leader;
2536     int		ret = OK;
2537     char_u	*alias;
2538 
2539     /*
2540      * Initialise variable so that clear_tv() can't mistake this for a
2541      * string and free a string that isn't there.
2542      */
2543     rettv->v_type = VAR_UNKNOWN;
2544 
2545     /*
2546      * Skip '!', '-' and '+' characters.  They are handled later.
2547      */
2548     start_leader = *arg;
2549     while (**arg == '!' || **arg == '-' || **arg == '+')
2550 	*arg = skipwhite(*arg + 1);
2551     end_leader = *arg;
2552 
2553     if (**arg == '.' && (!isdigit(*(*arg + 1))
2554 #ifdef FEAT_FLOAT
2555 	    || current_sctx.sc_version < 2
2556 #endif
2557 	    ))
2558     {
2559 	semsg(_(e_invexpr2), *arg);
2560 	++*arg;
2561 	return FAIL;
2562     }
2563 
2564     switch (**arg)
2565     {
2566     /*
2567      * Number constant.
2568      */
2569     case '0':
2570     case '1':
2571     case '2':
2572     case '3':
2573     case '4':
2574     case '5':
2575     case '6':
2576     case '7':
2577     case '8':
2578     case '9':
2579     case '.':	ret = get_number_tv(arg, rettv, evaluate, want_string);
2580 		break;
2581 
2582     /*
2583      * String constant: "string".
2584      */
2585     case '"':	ret = get_string_tv(arg, rettv, evaluate);
2586 		break;
2587 
2588     /*
2589      * Literal string constant: 'str''ing'.
2590      */
2591     case '\'':	ret = get_lit_string_tv(arg, rettv, evaluate);
2592 		break;
2593 
2594     /*
2595      * List: [expr, expr]
2596      */
2597     case '[':	ret = get_list_tv(arg, rettv, evaluate, TRUE);
2598 		break;
2599 
2600     /*
2601      * Dictionary: #{key: val, key: val}
2602      */
2603     case '#':	if ((*arg)[1] == '{')
2604 		{
2605 		    ++*arg;
2606 		    ret = eval_dict(arg, rettv, evaluate, TRUE);
2607 		}
2608 		else
2609 		    ret = NOTDONE;
2610 		break;
2611 
2612     /*
2613      * Lambda: {arg, arg -> expr}
2614      * Dictionary: {'key': val, 'key': val}
2615      */
2616     case '{':	ret = get_lambda_tv(arg, rettv, evaluate);
2617 		if (ret == NOTDONE)
2618 		    ret = eval_dict(arg, rettv, evaluate, FALSE);
2619 		break;
2620 
2621     /*
2622      * Option value: &name
2623      */
2624     case '&':	ret = get_option_tv(arg, rettv, evaluate);
2625 		break;
2626 
2627     /*
2628      * Environment variable: $VAR.
2629      */
2630     case '$':	ret = get_env_tv(arg, rettv, evaluate);
2631 		break;
2632 
2633     /*
2634      * Register contents: @r.
2635      */
2636     case '@':	++*arg;
2637 		if (evaluate)
2638 		{
2639 		    rettv->v_type = VAR_STRING;
2640 		    rettv->vval.v_string = get_reg_contents(**arg,
2641 							    GREG_EXPR_SRC);
2642 		}
2643 		if (**arg != NUL)
2644 		    ++*arg;
2645 		break;
2646 
2647     /*
2648      * nested expression: (expression).
2649      */
2650     case '(':	*arg = skipwhite(*arg + 1);
2651 		ret = eval1(arg, rettv, evaluate);	// recursive!
2652 		if (**arg == ')')
2653 		    ++*arg;
2654 		else if (ret == OK)
2655 		{
2656 		    emsg(_(e_missing_close));
2657 		    clear_tv(rettv);
2658 		    ret = FAIL;
2659 		}
2660 		break;
2661 
2662     default:	ret = NOTDONE;
2663 		break;
2664     }
2665 
2666     if (ret == NOTDONE)
2667     {
2668 	/*
2669 	 * Must be a variable or function name.
2670 	 * Can also be a curly-braces kind of name: {expr}.
2671 	 */
2672 	s = *arg;
2673 	len = get_name_len(arg, &alias, evaluate, TRUE);
2674 	if (alias != NULL)
2675 	    s = alias;
2676 
2677 	if (len <= 0)
2678 	    ret = FAIL;
2679 	else
2680 	{
2681 	    if (**arg == '(')		// recursive!
2682 		ret = eval_func(arg, s, len, rettv, evaluate, NULL);
2683 	    else if (evaluate)
2684 		ret = get_var_tv(s, len, rettv, NULL, TRUE, FALSE);
2685 	    else
2686 	    {
2687 		check_vars(s, len);
2688 		ret = OK;
2689 	    }
2690 	}
2691 	vim_free(alias);
2692     }
2693 
2694     *arg = skipwhite(*arg);
2695 
2696     // Handle following '[', '(' and '.' for expr[expr], expr.name,
2697     // expr(expr), expr->name(expr)
2698     if (ret == OK)
2699 	ret = handle_subscript(arg, rettv, evaluate, TRUE,
2700 						    start_leader, &end_leader);
2701 
2702     /*
2703      * Apply logical NOT and unary '-', from right to left, ignore '+'.
2704      */
2705     if (ret == OK && evaluate && end_leader > start_leader)
2706 	ret = eval7_leader(rettv, start_leader, &end_leader);
2707     return ret;
2708 }
2709 
2710 /*
2711  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
2712  * Adjusts "end_leaderp" until it is at "start_leader".
2713  */
2714     static int
2715 eval7_leader(typval_T *rettv, char_u *start_leader, char_u **end_leaderp)
2716 {
2717     char_u	*end_leader = *end_leaderp;
2718     int		ret = OK;
2719     int		error = FALSE;
2720     varnumber_T val = 0;
2721 #ifdef FEAT_FLOAT
2722     float_T	    f = 0.0;
2723 
2724     if (rettv->v_type == VAR_FLOAT)
2725 	f = rettv->vval.v_float;
2726     else
2727 #endif
2728 	val = tv_get_number_chk(rettv, &error);
2729     if (error)
2730     {
2731 	clear_tv(rettv);
2732 	ret = FAIL;
2733     }
2734     else
2735     {
2736 	while (end_leader > start_leader)
2737 	{
2738 	    --end_leader;
2739 	    if (*end_leader == '!')
2740 	    {
2741 #ifdef FEAT_FLOAT
2742 		if (rettv->v_type == VAR_FLOAT)
2743 		    f = !f;
2744 		else
2745 #endif
2746 		    val = !val;
2747 	    }
2748 	    else if (*end_leader == '-')
2749 	    {
2750 #ifdef FEAT_FLOAT
2751 		if (rettv->v_type == VAR_FLOAT)
2752 		    f = -f;
2753 		else
2754 #endif
2755 		    val = -val;
2756 	    }
2757 	}
2758 #ifdef FEAT_FLOAT
2759 	if (rettv->v_type == VAR_FLOAT)
2760 	{
2761 	    clear_tv(rettv);
2762 	    rettv->vval.v_float = f;
2763 	}
2764 	else
2765 #endif
2766 	{
2767 	    clear_tv(rettv);
2768 	    rettv->v_type = VAR_NUMBER;
2769 	    rettv->vval.v_number = val;
2770 	}
2771     }
2772     *end_leaderp = end_leader;
2773     return ret;
2774 }
2775 
2776 /*
2777  * Call the function referred to in "rettv".
2778  */
2779     static int
2780 call_func_rettv(
2781 	char_u	    **arg,
2782 	typval_T    *rettv,
2783 	int	    evaluate,
2784 	dict_T	    *selfdict,
2785 	typval_T    *basetv)
2786 {
2787     partial_T	*pt = NULL;
2788     funcexe_T	funcexe;
2789     typval_T	functv;
2790     char_u	*s;
2791     int		ret;
2792 
2793     // need to copy the funcref so that we can clear rettv
2794     if (evaluate)
2795     {
2796 	functv = *rettv;
2797 	rettv->v_type = VAR_UNKNOWN;
2798 
2799 	// Invoke the function.  Recursive!
2800 	if (functv.v_type == VAR_PARTIAL)
2801 	{
2802 	    pt = functv.vval.v_partial;
2803 	    s = partial_name(pt);
2804 	}
2805 	else
2806 	    s = functv.vval.v_string;
2807     }
2808     else
2809 	s = (char_u *)"";
2810 
2811     CLEAR_FIELD(funcexe);
2812     funcexe.firstline = curwin->w_cursor.lnum;
2813     funcexe.lastline = curwin->w_cursor.lnum;
2814     funcexe.evaluate = evaluate;
2815     funcexe.partial = pt;
2816     funcexe.selfdict = selfdict;
2817     funcexe.basetv = basetv;
2818     ret = get_func_tv(s, -1, rettv, arg, &funcexe);
2819 
2820     // Clear the funcref afterwards, so that deleting it while
2821     // evaluating the arguments is possible (see test55).
2822     if (evaluate)
2823 	clear_tv(&functv);
2824 
2825     return ret;
2826 }
2827 
2828 /*
2829  * Evaluate "->method()".
2830  * "*arg" points to the '-'.
2831  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
2832  */
2833     static int
2834 eval_lambda(
2835     char_u	**arg,
2836     typval_T	*rettv,
2837     int		evaluate,
2838     int		verbose)	// give error messages
2839 {
2840     typval_T	base = *rettv;
2841     int		ret;
2842 
2843     // Skip over the ->.
2844     *arg += 2;
2845     rettv->v_type = VAR_UNKNOWN;
2846 
2847     ret = get_lambda_tv(arg, rettv, evaluate);
2848     if (ret != OK)
2849 	return FAIL;
2850     else if (**arg != '(')
2851     {
2852 	if (verbose)
2853 	{
2854 	    if (*skipwhite(*arg) == '(')
2855 		emsg(_(e_nowhitespace));
2856 	    else
2857 		semsg(_(e_missing_paren), "lambda");
2858 	}
2859 	clear_tv(rettv);
2860 	ret = FAIL;
2861     }
2862     else
2863 	ret = call_func_rettv(arg, rettv, evaluate, NULL, &base);
2864 
2865     // Clear the funcref afterwards, so that deleting it while
2866     // evaluating the arguments is possible (see test55).
2867     if (evaluate)
2868 	clear_tv(&base);
2869 
2870     return ret;
2871 }
2872 
2873 /*
2874  * Evaluate "->method()".
2875  * "*arg" points to the '-'.
2876  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
2877  */
2878     static int
2879 eval_method(
2880     char_u	**arg,
2881     typval_T	*rettv,
2882     int		evaluate,
2883     int		verbose)	// give error messages
2884 {
2885     char_u	*name;
2886     long	len;
2887     char_u	*alias;
2888     typval_T	base = *rettv;
2889     int		ret;
2890 
2891     // Skip over the ->.
2892     *arg += 2;
2893     rettv->v_type = VAR_UNKNOWN;
2894 
2895     name = *arg;
2896     len = get_name_len(arg, &alias, evaluate, TRUE);
2897     if (alias != NULL)
2898 	name = alias;
2899 
2900     if (len <= 0)
2901     {
2902 	if (verbose)
2903 	    emsg(_("E260: Missing name after ->"));
2904 	ret = FAIL;
2905     }
2906     else
2907     {
2908 	if (**arg != '(')
2909 	{
2910 	    if (verbose)
2911 		semsg(_(e_missing_paren), name);
2912 	    ret = FAIL;
2913 	}
2914 	else if (VIM_ISWHITE((*arg)[-1]))
2915 	{
2916 	    if (verbose)
2917 		emsg(_(e_nowhitespace));
2918 	    ret = FAIL;
2919 	}
2920 	else
2921 	    ret = eval_func(arg, name, len, rettv, evaluate, &base);
2922     }
2923 
2924     // Clear the funcref afterwards, so that deleting it while
2925     // evaluating the arguments is possible (see test55).
2926     if (evaluate)
2927 	clear_tv(&base);
2928 
2929     return ret;
2930 }
2931 
2932 /*
2933  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
2934  * "*arg" points to the '[' or '.'.
2935  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
2936  */
2937     static int
2938 eval_index(
2939     char_u	**arg,
2940     typval_T	*rettv,
2941     int		evaluate,
2942     int		verbose)	// give error messages
2943 {
2944     int		empty1 = FALSE, empty2 = FALSE;
2945     typval_T	var1, var2;
2946     long	i;
2947     long	n1, n2 = 0;
2948     long	len = -1;
2949     int		range = FALSE;
2950     char_u	*s;
2951     char_u	*key = NULL;
2952 
2953     switch (rettv->v_type)
2954     {
2955 	case VAR_FUNC:
2956 	case VAR_PARTIAL:
2957 	    if (verbose)
2958 		emsg(_("E695: Cannot index a Funcref"));
2959 	    return FAIL;
2960 	case VAR_FLOAT:
2961 #ifdef FEAT_FLOAT
2962 	    if (verbose)
2963 		emsg(_(e_float_as_string));
2964 	    return FAIL;
2965 #endif
2966 	case VAR_BOOL:
2967 	case VAR_SPECIAL:
2968 	case VAR_JOB:
2969 	case VAR_CHANNEL:
2970 	    if (verbose)
2971 		emsg(_("E909: Cannot index a special variable"));
2972 	    return FAIL;
2973 	case VAR_UNKNOWN:
2974 	case VAR_ANY:
2975 	case VAR_VOID:
2976 	    if (evaluate)
2977 		return FAIL;
2978 	    // FALLTHROUGH
2979 
2980 	case VAR_STRING:
2981 	case VAR_NUMBER:
2982 	case VAR_LIST:
2983 	case VAR_DICT:
2984 	case VAR_BLOB:
2985 	    break;
2986     }
2987 
2988     init_tv(&var1);
2989     init_tv(&var2);
2990     if (**arg == '.')
2991     {
2992 	/*
2993 	 * dict.name
2994 	 */
2995 	key = *arg + 1;
2996 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
2997 	    ;
2998 	if (len == 0)
2999 	    return FAIL;
3000 	*arg = skipwhite(key + len);
3001     }
3002     else
3003     {
3004 	/*
3005 	 * something[idx]
3006 	 *
3007 	 * Get the (first) variable from inside the [].
3008 	 */
3009 	*arg = skipwhite(*arg + 1);
3010 	if (**arg == ':')
3011 	    empty1 = TRUE;
3012 	else if (eval1(arg, &var1, evaluate) == FAIL)	// recursive!
3013 	    return FAIL;
3014 	else if (evaluate && tv_get_string_chk(&var1) == NULL)
3015 	{
3016 	    // not a number or string
3017 	    clear_tv(&var1);
3018 	    return FAIL;
3019 	}
3020 
3021 	/*
3022 	 * Get the second variable from inside the [:].
3023 	 */
3024 	if (**arg == ':')
3025 	{
3026 	    range = TRUE;
3027 	    *arg = skipwhite(*arg + 1);
3028 	    if (**arg == ']')
3029 		empty2 = TRUE;
3030 	    else if (eval1(arg, &var2, evaluate) == FAIL)	// recursive!
3031 	    {
3032 		if (!empty1)
3033 		    clear_tv(&var1);
3034 		return FAIL;
3035 	    }
3036 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
3037 	    {
3038 		// not a number or string
3039 		if (!empty1)
3040 		    clear_tv(&var1);
3041 		clear_tv(&var2);
3042 		return FAIL;
3043 	    }
3044 	}
3045 
3046 	// Check for the ']'.
3047 	if (**arg != ']')
3048 	{
3049 	    if (verbose)
3050 		emsg(_(e_missbrac));
3051 	    clear_tv(&var1);
3052 	    if (range)
3053 		clear_tv(&var2);
3054 	    return FAIL;
3055 	}
3056 	*arg = skipwhite(*arg + 1);	// skip the ']'
3057     }
3058 
3059     if (evaluate)
3060     {
3061 	n1 = 0;
3062 	if (!empty1 && rettv->v_type != VAR_DICT)
3063 	{
3064 	    n1 = tv_get_number(&var1);
3065 	    clear_tv(&var1);
3066 	}
3067 	if (range)
3068 	{
3069 	    if (empty2)
3070 		n2 = -1;
3071 	    else
3072 	    {
3073 		n2 = tv_get_number(&var2);
3074 		clear_tv(&var2);
3075 	    }
3076 	}
3077 
3078 	switch (rettv->v_type)
3079 	{
3080 	    case VAR_UNKNOWN:
3081 	    case VAR_ANY:
3082 	    case VAR_VOID:
3083 	    case VAR_FUNC:
3084 	    case VAR_PARTIAL:
3085 	    case VAR_FLOAT:
3086 	    case VAR_BOOL:
3087 	    case VAR_SPECIAL:
3088 	    case VAR_JOB:
3089 	    case VAR_CHANNEL:
3090 		break; // not evaluating, skipping over subscript
3091 
3092 	    case VAR_NUMBER:
3093 	    case VAR_STRING:
3094 		s = tv_get_string(rettv);
3095 		len = (long)STRLEN(s);
3096 		if (range)
3097 		{
3098 		    // The resulting variable is a substring.  If the indexes
3099 		    // are out of range the result is empty.
3100 		    if (n1 < 0)
3101 		    {
3102 			n1 = len + n1;
3103 			if (n1 < 0)
3104 			    n1 = 0;
3105 		    }
3106 		    if (n2 < 0)
3107 			n2 = len + n2;
3108 		    else if (n2 >= len)
3109 			n2 = len;
3110 		    if (n1 >= len || n2 < 0 || n1 > n2)
3111 			s = NULL;
3112 		    else
3113 			s = vim_strnsave(s + n1, (int)(n2 - n1 + 1));
3114 		}
3115 		else
3116 		{
3117 		    // The resulting variable is a string of a single
3118 		    // character.  If the index is too big or negative the
3119 		    // result is empty.
3120 		    if (n1 >= len || n1 < 0)
3121 			s = NULL;
3122 		    else
3123 			s = vim_strnsave(s + n1, 1);
3124 		}
3125 		clear_tv(rettv);
3126 		rettv->v_type = VAR_STRING;
3127 		rettv->vval.v_string = s;
3128 		break;
3129 
3130 	    case VAR_BLOB:
3131 		len = blob_len(rettv->vval.v_blob);
3132 		if (range)
3133 		{
3134 		    // The resulting variable is a sub-blob.  If the indexes
3135 		    // are out of range the result is empty.
3136 		    if (n1 < 0)
3137 		    {
3138 			n1 = len + n1;
3139 			if (n1 < 0)
3140 			    n1 = 0;
3141 		    }
3142 		    if (n2 < 0)
3143 			n2 = len + n2;
3144 		    else if (n2 >= len)
3145 			n2 = len - 1;
3146 		    if (n1 >= len || n2 < 0 || n1 > n2)
3147 		    {
3148 			clear_tv(rettv);
3149 			rettv->v_type = VAR_BLOB;
3150 			rettv->vval.v_blob = NULL;
3151 		    }
3152 		    else
3153 		    {
3154 			blob_T  *blob = blob_alloc();
3155 
3156 			if (blob != NULL)
3157 			{
3158 			    if (ga_grow(&blob->bv_ga, n2 - n1 + 1) == FAIL)
3159 			    {
3160 				blob_free(blob);
3161 				return FAIL;
3162 			    }
3163 			    blob->bv_ga.ga_len = n2 - n1 + 1;
3164 			    for (i = n1; i <= n2; i++)
3165 				blob_set(blob, i - n1,
3166 					      blob_get(rettv->vval.v_blob, i));
3167 
3168 			    clear_tv(rettv);
3169 			    rettv_blob_set(rettv, blob);
3170 			}
3171 		    }
3172 		}
3173 		else
3174 		{
3175 		    // The resulting variable is a byte value.
3176 		    // If the index is too big or negative that is an error.
3177 		    if (n1 < 0)
3178 			n1 = len + n1;
3179 		    if (n1 < len && n1 >= 0)
3180 		    {
3181 			int v = blob_get(rettv->vval.v_blob, n1);
3182 
3183 			clear_tv(rettv);
3184 			rettv->v_type = VAR_NUMBER;
3185 			rettv->vval.v_number = v;
3186 		    }
3187 		    else
3188 			semsg(_(e_blobidx), n1);
3189 		}
3190 		break;
3191 
3192 	    case VAR_LIST:
3193 		len = list_len(rettv->vval.v_list);
3194 		if (n1 < 0)
3195 		    n1 = len + n1;
3196 		if (!empty1 && (n1 < 0 || n1 >= len))
3197 		{
3198 		    // For a range we allow invalid values and return an empty
3199 		    // list.  A list index out of range is an error.
3200 		    if (!range)
3201 		    {
3202 			if (verbose)
3203 			    semsg(_(e_listidx), n1);
3204 			return FAIL;
3205 		    }
3206 		    n1 = len;
3207 		}
3208 		if (range)
3209 		{
3210 		    list_T	*l;
3211 		    listitem_T	*item;
3212 
3213 		    if (n2 < 0)
3214 			n2 = len + n2;
3215 		    else if (n2 >= len)
3216 			n2 = len - 1;
3217 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
3218 			n2 = -1;
3219 		    l = list_alloc();
3220 		    if (l == NULL)
3221 			return FAIL;
3222 		    for (item = list_find(rettv->vval.v_list, n1);
3223 							       n1 <= n2; ++n1)
3224 		    {
3225 			if (list_append_tv(l, &item->li_tv) == FAIL)
3226 			{
3227 			    list_free(l);
3228 			    return FAIL;
3229 			}
3230 			item = item->li_next;
3231 		    }
3232 		    clear_tv(rettv);
3233 		    rettv_list_set(rettv, l);
3234 		}
3235 		else
3236 		{
3237 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
3238 		    clear_tv(rettv);
3239 		    *rettv = var1;
3240 		}
3241 		break;
3242 
3243 	    case VAR_DICT:
3244 		if (range)
3245 		{
3246 		    if (verbose)
3247 			emsg(_(e_dictrange));
3248 		    if (len == -1)
3249 			clear_tv(&var1);
3250 		    return FAIL;
3251 		}
3252 		{
3253 		    dictitem_T	*item;
3254 
3255 		    if (len == -1)
3256 		    {
3257 			key = tv_get_string_chk(&var1);
3258 			if (key == NULL)
3259 			{
3260 			    clear_tv(&var1);
3261 			    return FAIL;
3262 			}
3263 		    }
3264 
3265 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
3266 
3267 		    if (item == NULL && verbose)
3268 			semsg(_(e_dictkey), key);
3269 		    if (len == -1)
3270 			clear_tv(&var1);
3271 		    if (item == NULL)
3272 			return FAIL;
3273 
3274 		    copy_tv(&item->di_tv, &var1);
3275 		    clear_tv(rettv);
3276 		    *rettv = var1;
3277 		}
3278 		break;
3279 	}
3280     }
3281 
3282     return OK;
3283 }
3284 
3285 /*
3286  * Get an option value.
3287  * "arg" points to the '&' or '+' before the option name.
3288  * "arg" is advanced to character after the option name.
3289  * Return OK or FAIL.
3290  */
3291     int
3292 get_option_tv(
3293     char_u	**arg,
3294     typval_T	*rettv,	// when NULL, only check if option exists
3295     int		evaluate)
3296 {
3297     char_u	*option_end;
3298     long	numval;
3299     char_u	*stringval;
3300     int		opt_type;
3301     int		c;
3302     int		working = (**arg == '+');    // has("+option")
3303     int		ret = OK;
3304     int		opt_flags;
3305 
3306     /*
3307      * Isolate the option name and find its value.
3308      */
3309     option_end = find_option_end(arg, &opt_flags);
3310     if (option_end == NULL)
3311     {
3312 	if (rettv != NULL)
3313 	    semsg(_("E112: Option name missing: %s"), *arg);
3314 	return FAIL;
3315     }
3316 
3317     if (!evaluate)
3318     {
3319 	*arg = option_end;
3320 	return OK;
3321     }
3322 
3323     c = *option_end;
3324     *option_end = NUL;
3325     opt_type = get_option_value(*arg, &numval,
3326 			       rettv == NULL ? NULL : &stringval, opt_flags);
3327 
3328     if (opt_type == -3)			// invalid name
3329     {
3330 	if (rettv != NULL)
3331 	    semsg(_(e_unknown_option), *arg);
3332 	ret = FAIL;
3333     }
3334     else if (rettv != NULL)
3335     {
3336 	if (opt_type == -2)		// hidden string option
3337 	{
3338 	    rettv->v_type = VAR_STRING;
3339 	    rettv->vval.v_string = NULL;
3340 	}
3341 	else if (opt_type == -1)	// hidden number option
3342 	{
3343 	    rettv->v_type = VAR_NUMBER;
3344 	    rettv->vval.v_number = 0;
3345 	}
3346 	else if (opt_type == 1)		// number option
3347 	{
3348 	    rettv->v_type = VAR_NUMBER;
3349 	    rettv->vval.v_number = numval;
3350 	}
3351 	else				// string option
3352 	{
3353 	    rettv->v_type = VAR_STRING;
3354 	    rettv->vval.v_string = stringval;
3355 	}
3356     }
3357     else if (working && (opt_type == -2 || opt_type == -1))
3358 	ret = FAIL;
3359 
3360     *option_end = c;		    // put back for error messages
3361     *arg = option_end;
3362 
3363     return ret;
3364 }
3365 
3366 /*
3367  * Allocate a variable for a number constant.  Also deals with "0z" for blob.
3368  * Return OK or FAIL.
3369  */
3370     int
3371 get_number_tv(
3372 	char_u	    **arg,
3373 	typval_T    *rettv,
3374 	int	    evaluate,
3375 	int	    want_string UNUSED)
3376 {
3377     int		len;
3378 #ifdef FEAT_FLOAT
3379     char_u	*p;
3380     int		get_float = FALSE;
3381 
3382     // We accept a float when the format matches
3383     // "[0-9]\+\.[0-9]\+\([eE][+-]\?[0-9]\+\)\?".  This is very
3384     // strict to avoid backwards compatibility problems.
3385     // With script version 2 and later the leading digit can be
3386     // omitted.
3387     // Don't look for a float after the "." operator, so that
3388     // ":let vers = 1.2.3" doesn't fail.
3389     if (**arg == '.')
3390 	p = *arg;
3391     else
3392 	p = skipdigits(*arg + 1);
3393     if (!want_string && p[0] == '.' && vim_isdigit(p[1]))
3394     {
3395 	get_float = TRUE;
3396 	p = skipdigits(p + 2);
3397 	if (*p == 'e' || *p == 'E')
3398 	{
3399 	    ++p;
3400 	    if (*p == '-' || *p == '+')
3401 		++p;
3402 	    if (!vim_isdigit(*p))
3403 		get_float = FALSE;
3404 	    else
3405 		p = skipdigits(p + 1);
3406 	}
3407 	if (ASCII_ISALPHA(*p) || *p == '.')
3408 	    get_float = FALSE;
3409     }
3410     if (get_float)
3411     {
3412 	float_T	f;
3413 
3414 	*arg += string2float(*arg, &f);
3415 	if (evaluate)
3416 	{
3417 	    rettv->v_type = VAR_FLOAT;
3418 	    rettv->vval.v_float = f;
3419 	}
3420     }
3421     else
3422 #endif
3423     if (**arg == '0' && ((*arg)[1] == 'z' || (*arg)[1] == 'Z'))
3424     {
3425 	char_u  *bp;
3426 	blob_T  *blob = NULL;  // init for gcc
3427 
3428 	// Blob constant: 0z0123456789abcdef
3429 	if (evaluate)
3430 	    blob = blob_alloc();
3431 	for (bp = *arg + 2; vim_isxdigit(bp[0]); bp += 2)
3432 	{
3433 	    if (!vim_isxdigit(bp[1]))
3434 	    {
3435 		if (blob != NULL)
3436 		{
3437 		    emsg(_("E973: Blob literal should have an even number of hex characters"));
3438 		    ga_clear(&blob->bv_ga);
3439 		    VIM_CLEAR(blob);
3440 		}
3441 		return FAIL;
3442 	    }
3443 	    if (blob != NULL)
3444 		ga_append(&blob->bv_ga,
3445 			     (hex2nr(*bp) << 4) + hex2nr(*(bp+1)));
3446 	    if (bp[2] == '.' && vim_isxdigit(bp[3]))
3447 		++bp;
3448 	}
3449 	if (blob != NULL)
3450 	    rettv_blob_set(rettv, blob);
3451 	*arg = bp;
3452     }
3453     else
3454     {
3455 	varnumber_T	n;
3456 
3457 	// decimal, hex or octal number
3458 	vim_str2nr(*arg, NULL, &len, current_sctx.sc_version >= 4
3459 		      ? STR2NR_NO_OCT + STR2NR_QUOTE
3460 		      : STR2NR_ALL, &n, NULL, 0, TRUE);
3461 	if (len == 0)
3462 	{
3463 	    semsg(_(e_invexpr2), *arg);
3464 	    return FAIL;
3465 	}
3466 	*arg += len;
3467 	if (evaluate)
3468 	{
3469 	    rettv->v_type = VAR_NUMBER;
3470 	    rettv->vval.v_number = n;
3471 	}
3472     }
3473     return OK;
3474 }
3475 
3476 /*
3477  * Allocate a variable for a string constant.
3478  * Return OK or FAIL.
3479  */
3480     int
3481 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
3482 {
3483     char_u	*p;
3484     char_u	*name;
3485     int		extra = 0;
3486 
3487     /*
3488      * Find the end of the string, skipping backslashed characters.
3489      */
3490     for (p = *arg + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
3491     {
3492 	if (*p == '\\' && p[1] != NUL)
3493 	{
3494 	    ++p;
3495 	    // A "\<x>" form occupies at least 4 characters, and produces up
3496 	    // to 6 characters: reserve space for 2 extra
3497 	    if (*p == '<')
3498 		extra += 2;
3499 	}
3500     }
3501 
3502     if (*p != '"')
3503     {
3504 	semsg(_("E114: Missing quote: %s"), *arg);
3505 	return FAIL;
3506     }
3507 
3508     // If only parsing, set *arg and return here
3509     if (!evaluate)
3510     {
3511 	*arg = p + 1;
3512 	return OK;
3513     }
3514 
3515     /*
3516      * Copy the string into allocated memory, handling backslashed
3517      * characters.
3518      */
3519     name = alloc(p - *arg + extra);
3520     if (name == NULL)
3521 	return FAIL;
3522     rettv->v_type = VAR_STRING;
3523     rettv->vval.v_string = name;
3524 
3525     for (p = *arg + 1; *p != NUL && *p != '"'; )
3526     {
3527 	if (*p == '\\')
3528 	{
3529 	    switch (*++p)
3530 	    {
3531 		case 'b': *name++ = BS; ++p; break;
3532 		case 'e': *name++ = ESC; ++p; break;
3533 		case 'f': *name++ = FF; ++p; break;
3534 		case 'n': *name++ = NL; ++p; break;
3535 		case 'r': *name++ = CAR; ++p; break;
3536 		case 't': *name++ = TAB; ++p; break;
3537 
3538 		case 'X': // hex: "\x1", "\x12"
3539 		case 'x':
3540 		case 'u': // Unicode: "\u0023"
3541 		case 'U':
3542 			  if (vim_isxdigit(p[1]))
3543 			  {
3544 			      int	n, nr;
3545 			      int	c = toupper(*p);
3546 
3547 			      if (c == 'X')
3548 				  n = 2;
3549 			      else if (*p == 'u')
3550 				  n = 4;
3551 			      else
3552 				  n = 8;
3553 			      nr = 0;
3554 			      while (--n >= 0 && vim_isxdigit(p[1]))
3555 			      {
3556 				  ++p;
3557 				  nr = (nr << 4) + hex2nr(*p);
3558 			      }
3559 			      ++p;
3560 			      // For "\u" store the number according to
3561 			      // 'encoding'.
3562 			      if (c != 'X')
3563 				  name += (*mb_char2bytes)(nr, name);
3564 			      else
3565 				  *name++ = nr;
3566 			  }
3567 			  break;
3568 
3569 			  // octal: "\1", "\12", "\123"
3570 		case '0':
3571 		case '1':
3572 		case '2':
3573 		case '3':
3574 		case '4':
3575 		case '5':
3576 		case '6':
3577 		case '7': *name = *p++ - '0';
3578 			  if (*p >= '0' && *p <= '7')
3579 			  {
3580 			      *name = (*name << 3) + *p++ - '0';
3581 			      if (*p >= '0' && *p <= '7')
3582 				  *name = (*name << 3) + *p++ - '0';
3583 			  }
3584 			  ++name;
3585 			  break;
3586 
3587 			    // Special key, e.g.: "\<C-W>"
3588 		case '<': extra = trans_special(&p, name, TRUE, TRUE,
3589 								   TRUE, NULL);
3590 			  if (extra != 0)
3591 			  {
3592 			      name += extra;
3593 			      break;
3594 			  }
3595 			  // FALLTHROUGH
3596 
3597 		default:  MB_COPY_CHAR(p, name);
3598 			  break;
3599 	    }
3600 	}
3601 	else
3602 	    MB_COPY_CHAR(p, name);
3603 
3604     }
3605     *name = NUL;
3606     if (*p != NUL) // just in case
3607 	++p;
3608     *arg = p;
3609 
3610     return OK;
3611 }
3612 
3613 /*
3614  * Allocate a variable for a 'str''ing' constant.
3615  * Return OK or FAIL.
3616  */
3617     int
3618 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
3619 {
3620     char_u	*p;
3621     char_u	*str;
3622     int		reduce = 0;
3623 
3624     /*
3625      * Find the end of the string, skipping ''.
3626      */
3627     for (p = *arg + 1; *p != NUL; MB_PTR_ADV(p))
3628     {
3629 	if (*p == '\'')
3630 	{
3631 	    if (p[1] != '\'')
3632 		break;
3633 	    ++reduce;
3634 	    ++p;
3635 	}
3636     }
3637 
3638     if (*p != '\'')
3639     {
3640 	semsg(_("E115: Missing quote: %s"), *arg);
3641 	return FAIL;
3642     }
3643 
3644     // If only parsing return after setting "*arg"
3645     if (!evaluate)
3646     {
3647 	*arg = p + 1;
3648 	return OK;
3649     }
3650 
3651     /*
3652      * Copy the string into allocated memory, handling '' to ' reduction.
3653      */
3654     str = alloc((p - *arg) - reduce);
3655     if (str == NULL)
3656 	return FAIL;
3657     rettv->v_type = VAR_STRING;
3658     rettv->vval.v_string = str;
3659 
3660     for (p = *arg + 1; *p != NUL; )
3661     {
3662 	if (*p == '\'')
3663 	{
3664 	    if (p[1] != '\'')
3665 		break;
3666 	    ++p;
3667 	}
3668 	MB_COPY_CHAR(p, str);
3669     }
3670     *str = NUL;
3671     *arg = p + 1;
3672 
3673     return OK;
3674 }
3675 
3676 /*
3677  * Return the function name of partial "pt".
3678  */
3679     char_u *
3680 partial_name(partial_T *pt)
3681 {
3682     if (pt->pt_name != NULL)
3683 	return pt->pt_name;
3684     return pt->pt_func->uf_name;
3685 }
3686 
3687     static void
3688 partial_free(partial_T *pt)
3689 {
3690     int i;
3691 
3692     for (i = 0; i < pt->pt_argc; ++i)
3693 	clear_tv(&pt->pt_argv[i]);
3694     vim_free(pt->pt_argv);
3695     dict_unref(pt->pt_dict);
3696     if (pt->pt_name != NULL)
3697     {
3698 	func_unref(pt->pt_name);
3699 	vim_free(pt->pt_name);
3700     }
3701     else
3702 	func_ptr_unref(pt->pt_func);
3703     vim_free(pt);
3704 }
3705 
3706 /*
3707  * Unreference a closure: decrement the reference count and free it when it
3708  * becomes zero.
3709  */
3710     void
3711 partial_unref(partial_T *pt)
3712 {
3713     if (pt != NULL && --pt->pt_refcount <= 0)
3714 	partial_free(pt);
3715 }
3716 
3717 static int tv_equal_recurse_limit;
3718 
3719     static int
3720 func_equal(
3721     typval_T *tv1,
3722     typval_T *tv2,
3723     int	     ic)	    // ignore case
3724 {
3725     char_u	*s1, *s2;
3726     dict_T	*d1, *d2;
3727     int		a1, a2;
3728     int		i;
3729 
3730     // empty and NULL function name considered the same
3731     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
3732 					   : partial_name(tv1->vval.v_partial);
3733     if (s1 != NULL && *s1 == NUL)
3734 	s1 = NULL;
3735     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
3736 					   : partial_name(tv2->vval.v_partial);
3737     if (s2 != NULL && *s2 == NUL)
3738 	s2 = NULL;
3739     if (s1 == NULL || s2 == NULL)
3740     {
3741 	if (s1 != s2)
3742 	    return FALSE;
3743     }
3744     else if (STRCMP(s1, s2) != 0)
3745 	return FALSE;
3746 
3747     // empty dict and NULL dict is different
3748     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
3749     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
3750     if (d1 == NULL || d2 == NULL)
3751     {
3752 	if (d1 != d2)
3753 	    return FALSE;
3754     }
3755     else if (!dict_equal(d1, d2, ic, TRUE))
3756 	return FALSE;
3757 
3758     // empty list and no list considered the same
3759     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
3760     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
3761     if (a1 != a2)
3762 	return FALSE;
3763     for (i = 0; i < a1; ++i)
3764 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
3765 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
3766 	    return FALSE;
3767 
3768     return TRUE;
3769 }
3770 
3771 /*
3772  * Return TRUE if "tv1" and "tv2" have the same value.
3773  * Compares the items just like "==" would compare them, but strings and
3774  * numbers are different.  Floats and numbers are also different.
3775  */
3776     int
3777 tv_equal(
3778     typval_T *tv1,
3779     typval_T *tv2,
3780     int	     ic,	    // ignore case
3781     int	     recursive)	    // TRUE when used recursively
3782 {
3783     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3784     char_u	*s1, *s2;
3785     static int  recursive_cnt = 0;	    // catch recursive loops
3786     int		r;
3787 
3788     // Catch lists and dicts that have an endless loop by limiting
3789     // recursiveness to a limit.  We guess they are equal then.
3790     // A fixed limit has the problem of still taking an awful long time.
3791     // Reduce the limit every time running into it. That should work fine for
3792     // deeply linked structures that are not recursively linked and catch
3793     // recursiveness quickly.
3794     if (!recursive)
3795 	tv_equal_recurse_limit = 1000;
3796     if (recursive_cnt >= tv_equal_recurse_limit)
3797     {
3798 	--tv_equal_recurse_limit;
3799 	return TRUE;
3800     }
3801 
3802     // For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
3803     // arguments.
3804     if ((tv1->v_type == VAR_FUNC
3805 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
3806 	    && (tv2->v_type == VAR_FUNC
3807 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
3808     {
3809 	++recursive_cnt;
3810 	r = func_equal(tv1, tv2, ic);
3811 	--recursive_cnt;
3812 	return r;
3813     }
3814 
3815     if (tv1->v_type != tv2->v_type)
3816 	return FALSE;
3817 
3818     switch (tv1->v_type)
3819     {
3820 	case VAR_LIST:
3821 	    ++recursive_cnt;
3822 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
3823 	    --recursive_cnt;
3824 	    return r;
3825 
3826 	case VAR_DICT:
3827 	    ++recursive_cnt;
3828 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
3829 	    --recursive_cnt;
3830 	    return r;
3831 
3832 	case VAR_BLOB:
3833 	    return blob_equal(tv1->vval.v_blob, tv2->vval.v_blob);
3834 
3835 	case VAR_NUMBER:
3836 	case VAR_BOOL:
3837 	case VAR_SPECIAL:
3838 	    return tv1->vval.v_number == tv2->vval.v_number;
3839 
3840 	case VAR_STRING:
3841 	    s1 = tv_get_string_buf(tv1, buf1);
3842 	    s2 = tv_get_string_buf(tv2, buf2);
3843 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
3844 
3845 	case VAR_FLOAT:
3846 #ifdef FEAT_FLOAT
3847 	    return tv1->vval.v_float == tv2->vval.v_float;
3848 #endif
3849 	case VAR_JOB:
3850 #ifdef FEAT_JOB_CHANNEL
3851 	    return tv1->vval.v_job == tv2->vval.v_job;
3852 #endif
3853 	case VAR_CHANNEL:
3854 #ifdef FEAT_JOB_CHANNEL
3855 	    return tv1->vval.v_channel == tv2->vval.v_channel;
3856 #endif
3857 
3858 	case VAR_PARTIAL:
3859 	    return tv1->vval.v_partial == tv2->vval.v_partial;
3860 
3861 	case VAR_FUNC:
3862 	    return tv1->vval.v_string == tv2->vval.v_string;
3863 
3864 	case VAR_UNKNOWN:
3865 	case VAR_ANY:
3866 	case VAR_VOID:
3867 	    break;
3868     }
3869 
3870     // VAR_UNKNOWN can be the result of a invalid expression, let's say it
3871     // does not equal anything, not even itself.
3872     return FALSE;
3873 }
3874 
3875 /*
3876  * Return the next (unique) copy ID.
3877  * Used for serializing nested structures.
3878  */
3879     int
3880 get_copyID(void)
3881 {
3882     current_copyID += COPYID_INC;
3883     return current_copyID;
3884 }
3885 
3886 /*
3887  * Garbage collection for lists and dictionaries.
3888  *
3889  * We use reference counts to be able to free most items right away when they
3890  * are no longer used.  But for composite items it's possible that it becomes
3891  * unused while the reference count is > 0: When there is a recursive
3892  * reference.  Example:
3893  *	:let l = [1, 2, 3]
3894  *	:let d = {9: l}
3895  *	:let l[1] = d
3896  *
3897  * Since this is quite unusual we handle this with garbage collection: every
3898  * once in a while find out which lists and dicts are not referenced from any
3899  * variable.
3900  *
3901  * Here is a good reference text about garbage collection (refers to Python
3902  * but it applies to all reference-counting mechanisms):
3903  *	http://python.ca/nas/python/gc/
3904  */
3905 
3906 /*
3907  * Do garbage collection for lists and dicts.
3908  * When "testing" is TRUE this is called from test_garbagecollect_now().
3909  * Return TRUE if some memory was freed.
3910  */
3911     int
3912 garbage_collect(int testing)
3913 {
3914     int		copyID;
3915     int		abort = FALSE;
3916     buf_T	*buf;
3917     win_T	*wp;
3918     int		did_free = FALSE;
3919     tabpage_T	*tp;
3920 
3921     if (!testing)
3922     {
3923 	// Only do this once.
3924 	want_garbage_collect = FALSE;
3925 	may_garbage_collect = FALSE;
3926 	garbage_collect_at_exit = FALSE;
3927     }
3928 
3929     // The execution stack can grow big, limit the size.
3930     if (exestack.ga_maxlen - exestack.ga_len > 500)
3931     {
3932 	size_t	new_len;
3933 	char_u	*pp;
3934 	int	n;
3935 
3936 	// Keep 150% of the current size, with a minimum of the growth size.
3937 	n = exestack.ga_len / 2;
3938 	if (n < exestack.ga_growsize)
3939 	    n = exestack.ga_growsize;
3940 
3941 	// Don't make it bigger though.
3942 	if (exestack.ga_len + n < exestack.ga_maxlen)
3943 	{
3944 	    new_len = exestack.ga_itemsize * (exestack.ga_len + n);
3945 	    pp = vim_realloc(exestack.ga_data, new_len);
3946 	    if (pp == NULL)
3947 		return FAIL;
3948 	    exestack.ga_maxlen = exestack.ga_len + n;
3949 	    exestack.ga_data = pp;
3950 	}
3951     }
3952 
3953     // We advance by two because we add one for items referenced through
3954     // previous_funccal.
3955     copyID = get_copyID();
3956 
3957     /*
3958      * 1. Go through all accessible variables and mark all lists and dicts
3959      *    with copyID.
3960      */
3961 
3962     // Don't free variables in the previous_funccal list unless they are only
3963     // referenced through previous_funccal.  This must be first, because if
3964     // the item is referenced elsewhere the funccal must not be freed.
3965     abort = abort || set_ref_in_previous_funccal(copyID);
3966 
3967     // script-local variables
3968     abort = abort || garbage_collect_scriptvars(copyID);
3969 
3970     // buffer-local variables
3971     FOR_ALL_BUFFERS(buf)
3972 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
3973 								  NULL, NULL);
3974 
3975     // window-local variables
3976     FOR_ALL_TAB_WINDOWS(tp, wp)
3977 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3978 								  NULL, NULL);
3979     if (aucmd_win != NULL)
3980 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
3981 								  NULL, NULL);
3982 #ifdef FEAT_PROP_POPUP
3983     FOR_ALL_POPUPWINS(wp)
3984 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3985 								  NULL, NULL);
3986     FOR_ALL_TABPAGES(tp)
3987 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
3988 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3989 								  NULL, NULL);
3990 #endif
3991 
3992     // tabpage-local variables
3993     FOR_ALL_TABPAGES(tp)
3994 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
3995 								  NULL, NULL);
3996     // global variables
3997     abort = abort || garbage_collect_globvars(copyID);
3998 
3999     // function-local variables
4000     abort = abort || set_ref_in_call_stack(copyID);
4001 
4002     // named functions (matters for closures)
4003     abort = abort || set_ref_in_functions(copyID);
4004 
4005     // function call arguments, if v:testing is set.
4006     abort = abort || set_ref_in_func_args(copyID);
4007 
4008     // v: vars
4009     abort = abort || garbage_collect_vimvars(copyID);
4010 
4011     // callbacks in buffers
4012     abort = abort || set_ref_in_buffers(copyID);
4013 
4014 #ifdef FEAT_LUA
4015     abort = abort || set_ref_in_lua(copyID);
4016 #endif
4017 
4018 #ifdef FEAT_PYTHON
4019     abort = abort || set_ref_in_python(copyID);
4020 #endif
4021 
4022 #ifdef FEAT_PYTHON3
4023     abort = abort || set_ref_in_python3(copyID);
4024 #endif
4025 
4026 #ifdef FEAT_JOB_CHANNEL
4027     abort = abort || set_ref_in_channel(copyID);
4028     abort = abort || set_ref_in_job(copyID);
4029 #endif
4030 #ifdef FEAT_NETBEANS_INTG
4031     abort = abort || set_ref_in_nb_channel(copyID);
4032 #endif
4033 
4034 #ifdef FEAT_TIMERS
4035     abort = abort || set_ref_in_timer(copyID);
4036 #endif
4037 
4038 #ifdef FEAT_QUICKFIX
4039     abort = abort || set_ref_in_quickfix(copyID);
4040 #endif
4041 
4042 #ifdef FEAT_TERMINAL
4043     abort = abort || set_ref_in_term(copyID);
4044 #endif
4045 
4046 #ifdef FEAT_PROP_POPUP
4047     abort = abort || set_ref_in_popups(copyID);
4048 #endif
4049 
4050     if (!abort)
4051     {
4052 	/*
4053 	 * 2. Free lists and dictionaries that are not referenced.
4054 	 */
4055 	did_free = free_unref_items(copyID);
4056 
4057 	/*
4058 	 * 3. Check if any funccal can be freed now.
4059 	 *    This may call us back recursively.
4060 	 */
4061 	free_unref_funccal(copyID, testing);
4062     }
4063     else if (p_verbose > 0)
4064     {
4065 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
4066     }
4067 
4068     return did_free;
4069 }
4070 
4071 /*
4072  * Free lists, dictionaries, channels and jobs that are no longer referenced.
4073  */
4074     static int
4075 free_unref_items(int copyID)
4076 {
4077     int		did_free = FALSE;
4078 
4079     // Let all "free" functions know that we are here.  This means no
4080     // dictionaries, lists, channels or jobs are to be freed, because we will
4081     // do that here.
4082     in_free_unref_items = TRUE;
4083 
4084     /*
4085      * PASS 1: free the contents of the items.  We don't free the items
4086      * themselves yet, so that it is possible to decrement refcount counters
4087      */
4088 
4089     // Go through the list of dicts and free items without the copyID.
4090     did_free |= dict_free_nonref(copyID);
4091 
4092     // Go through the list of lists and free items without the copyID.
4093     did_free |= list_free_nonref(copyID);
4094 
4095 #ifdef FEAT_JOB_CHANNEL
4096     // Go through the list of jobs and free items without the copyID. This
4097     // must happen before doing channels, because jobs refer to channels, but
4098     // the reference from the channel to the job isn't tracked.
4099     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4100 
4101     // Go through the list of channels and free items without the copyID.
4102     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4103 #endif
4104 
4105     /*
4106      * PASS 2: free the items themselves.
4107      */
4108     dict_free_items(copyID);
4109     list_free_items(copyID);
4110 
4111 #ifdef FEAT_JOB_CHANNEL
4112     // Go through the list of jobs and free items without the copyID. This
4113     // must happen before doing channels, because jobs refer to channels, but
4114     // the reference from the channel to the job isn't tracked.
4115     free_unused_jobs(copyID, COPYID_MASK);
4116 
4117     // Go through the list of channels and free items without the copyID.
4118     free_unused_channels(copyID, COPYID_MASK);
4119 #endif
4120 
4121     in_free_unref_items = FALSE;
4122 
4123     return did_free;
4124 }
4125 
4126 /*
4127  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4128  * "list_stack" is used to add lists to be marked.  Can be NULL.
4129  *
4130  * Returns TRUE if setting references failed somehow.
4131  */
4132     int
4133 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4134 {
4135     int		todo;
4136     int		abort = FALSE;
4137     hashitem_T	*hi;
4138     hashtab_T	*cur_ht;
4139     ht_stack_T	*ht_stack = NULL;
4140     ht_stack_T	*tempitem;
4141 
4142     cur_ht = ht;
4143     for (;;)
4144     {
4145 	if (!abort)
4146 	{
4147 	    // Mark each item in the hashtab.  If the item contains a hashtab
4148 	    // it is added to ht_stack, if it contains a list it is added to
4149 	    // list_stack.
4150 	    todo = (int)cur_ht->ht_used;
4151 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4152 		if (!HASHITEM_EMPTY(hi))
4153 		{
4154 		    --todo;
4155 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4156 						       &ht_stack, list_stack);
4157 		}
4158 	}
4159 
4160 	if (ht_stack == NULL)
4161 	    break;
4162 
4163 	// take an item from the stack
4164 	cur_ht = ht_stack->ht;
4165 	tempitem = ht_stack;
4166 	ht_stack = ht_stack->prev;
4167 	free(tempitem);
4168     }
4169 
4170     return abort;
4171 }
4172 
4173 /*
4174  * Mark a dict and its items with "copyID".
4175  * Returns TRUE if setting references failed somehow.
4176  */
4177     int
4178 set_ref_in_dict(dict_T *d, int copyID)
4179 {
4180     if (d != NULL && d->dv_copyID != copyID)
4181     {
4182 	d->dv_copyID = copyID;
4183 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4184     }
4185     return FALSE;
4186 }
4187 
4188 /*
4189  * Mark a list and its items with "copyID".
4190  * Returns TRUE if setting references failed somehow.
4191  */
4192     int
4193 set_ref_in_list(list_T *ll, int copyID)
4194 {
4195     if (ll != NULL && ll->lv_copyID != copyID)
4196     {
4197 	ll->lv_copyID = copyID;
4198 	return set_ref_in_list_items(ll, copyID, NULL);
4199     }
4200     return FALSE;
4201 }
4202 
4203 /*
4204  * Mark all lists and dicts referenced through list "l" with "copyID".
4205  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4206  *
4207  * Returns TRUE if setting references failed somehow.
4208  */
4209     int
4210 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4211 {
4212     listitem_T	 *li;
4213     int		 abort = FALSE;
4214     list_T	 *cur_l;
4215     list_stack_T *list_stack = NULL;
4216     list_stack_T *tempitem;
4217 
4218     cur_l = l;
4219     for (;;)
4220     {
4221 	if (!abort && cur_l->lv_first != &range_list_item)
4222 	    // Mark each item in the list.  If the item contains a hashtab
4223 	    // it is added to ht_stack, if it contains a list it is added to
4224 	    // list_stack.
4225 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4226 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4227 						       ht_stack, &list_stack);
4228 	if (list_stack == NULL)
4229 	    break;
4230 
4231 	// take an item from the stack
4232 	cur_l = list_stack->list;
4233 	tempitem = list_stack;
4234 	list_stack = list_stack->prev;
4235 	free(tempitem);
4236     }
4237 
4238     return abort;
4239 }
4240 
4241 /*
4242  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4243  * "list_stack" is used to add lists to be marked.  Can be NULL.
4244  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4245  *
4246  * Returns TRUE if setting references failed somehow.
4247  */
4248     int
4249 set_ref_in_item(
4250     typval_T	    *tv,
4251     int		    copyID,
4252     ht_stack_T	    **ht_stack,
4253     list_stack_T    **list_stack)
4254 {
4255     int		abort = FALSE;
4256 
4257     if (tv->v_type == VAR_DICT)
4258     {
4259 	dict_T	*dd = tv->vval.v_dict;
4260 
4261 	if (dd != NULL && dd->dv_copyID != copyID)
4262 	{
4263 	    // Didn't see this dict yet.
4264 	    dd->dv_copyID = copyID;
4265 	    if (ht_stack == NULL)
4266 	    {
4267 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4268 	    }
4269 	    else
4270 	    {
4271 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
4272 		if (newitem == NULL)
4273 		    abort = TRUE;
4274 		else
4275 		{
4276 		    newitem->ht = &dd->dv_hashtab;
4277 		    newitem->prev = *ht_stack;
4278 		    *ht_stack = newitem;
4279 		}
4280 	    }
4281 	}
4282     }
4283     else if (tv->v_type == VAR_LIST)
4284     {
4285 	list_T	*ll = tv->vval.v_list;
4286 
4287 	if (ll != NULL && ll->lv_copyID != copyID)
4288 	{
4289 	    // Didn't see this list yet.
4290 	    ll->lv_copyID = copyID;
4291 	    if (list_stack == NULL)
4292 	    {
4293 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4294 	    }
4295 	    else
4296 	    {
4297 		list_stack_T *newitem = (list_stack_T*)malloc(
4298 							sizeof(list_stack_T));
4299 		if (newitem == NULL)
4300 		    abort = TRUE;
4301 		else
4302 		{
4303 		    newitem->list = ll;
4304 		    newitem->prev = *list_stack;
4305 		    *list_stack = newitem;
4306 		}
4307 	    }
4308 	}
4309     }
4310     else if (tv->v_type == VAR_FUNC)
4311     {
4312 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4313     }
4314     else if (tv->v_type == VAR_PARTIAL)
4315     {
4316 	partial_T	*pt = tv->vval.v_partial;
4317 	int		i;
4318 
4319 	// A partial does not have a copyID, because it cannot contain itself.
4320 	if (pt != NULL)
4321 	{
4322 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4323 
4324 	    if (pt->pt_dict != NULL)
4325 	    {
4326 		typval_T dtv;
4327 
4328 		dtv.v_type = VAR_DICT;
4329 		dtv.vval.v_dict = pt->pt_dict;
4330 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4331 	    }
4332 
4333 	    for (i = 0; i < pt->pt_argc; ++i)
4334 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4335 							ht_stack, list_stack);
4336 	}
4337     }
4338 #ifdef FEAT_JOB_CHANNEL
4339     else if (tv->v_type == VAR_JOB)
4340     {
4341 	job_T	    *job = tv->vval.v_job;
4342 	typval_T    dtv;
4343 
4344 	if (job != NULL && job->jv_copyID != copyID)
4345 	{
4346 	    job->jv_copyID = copyID;
4347 	    if (job->jv_channel != NULL)
4348 	    {
4349 		dtv.v_type = VAR_CHANNEL;
4350 		dtv.vval.v_channel = job->jv_channel;
4351 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4352 	    }
4353 	    if (job->jv_exit_cb.cb_partial != NULL)
4354 	    {
4355 		dtv.v_type = VAR_PARTIAL;
4356 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4357 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4358 	    }
4359 	}
4360     }
4361     else if (tv->v_type == VAR_CHANNEL)
4362     {
4363 	channel_T   *ch =tv->vval.v_channel;
4364 	ch_part_T   part;
4365 	typval_T    dtv;
4366 	jsonq_T	    *jq;
4367 	cbq_T	    *cq;
4368 
4369 	if (ch != NULL && ch->ch_copyID != copyID)
4370 	{
4371 	    ch->ch_copyID = copyID;
4372 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4373 	    {
4374 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4375 							     jq = jq->jq_next)
4376 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4377 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4378 							     cq = cq->cq_next)
4379 		    if (cq->cq_callback.cb_partial != NULL)
4380 		    {
4381 			dtv.v_type = VAR_PARTIAL;
4382 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4383 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4384 		    }
4385 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4386 		{
4387 		    dtv.v_type = VAR_PARTIAL;
4388 		    dtv.vval.v_partial =
4389 				      ch->ch_part[part].ch_callback.cb_partial;
4390 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4391 		}
4392 	    }
4393 	    if (ch->ch_callback.cb_partial != NULL)
4394 	    {
4395 		dtv.v_type = VAR_PARTIAL;
4396 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4397 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4398 	    }
4399 	    if (ch->ch_close_cb.cb_partial != NULL)
4400 	    {
4401 		dtv.v_type = VAR_PARTIAL;
4402 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4403 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4404 	    }
4405 	}
4406     }
4407 #endif
4408     return abort;
4409 }
4410 
4411 /*
4412  * Return a string with the string representation of a variable.
4413  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4414  * "numbuf" is used for a number.
4415  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4416  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4417  * stings as "string()", otherwise does not put quotes around strings, as
4418  * ":echo" displays values.
4419  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4420  * are replaced with "...".
4421  * May return NULL.
4422  */
4423     char_u *
4424 echo_string_core(
4425     typval_T	*tv,
4426     char_u	**tofree,
4427     char_u	*numbuf,
4428     int		copyID,
4429     int		echo_style,
4430     int		restore_copyID,
4431     int		composite_val)
4432 {
4433     static int	recurse = 0;
4434     char_u	*r = NULL;
4435 
4436     if (recurse >= DICT_MAXNEST)
4437     {
4438 	if (!did_echo_string_emsg)
4439 	{
4440 	    // Only give this message once for a recursive call to avoid
4441 	    // flooding the user with errors.  And stop iterating over lists
4442 	    // and dicts.
4443 	    did_echo_string_emsg = TRUE;
4444 	    emsg(_("E724: variable nested too deep for displaying"));
4445 	}
4446 	*tofree = NULL;
4447 	return (char_u *)"{E724}";
4448     }
4449     ++recurse;
4450 
4451     switch (tv->v_type)
4452     {
4453 	case VAR_STRING:
4454 	    if (echo_style && !composite_val)
4455 	    {
4456 		*tofree = NULL;
4457 		r = tv->vval.v_string;
4458 		if (r == NULL)
4459 		    r = (char_u *)"";
4460 	    }
4461 	    else
4462 	    {
4463 		*tofree = string_quote(tv->vval.v_string, FALSE);
4464 		r = *tofree;
4465 	    }
4466 	    break;
4467 
4468 	case VAR_FUNC:
4469 	    if (echo_style)
4470 	    {
4471 		*tofree = NULL;
4472 		r = tv->vval.v_string;
4473 	    }
4474 	    else
4475 	    {
4476 		*tofree = string_quote(tv->vval.v_string, TRUE);
4477 		r = *tofree;
4478 	    }
4479 	    break;
4480 
4481 	case VAR_PARTIAL:
4482 	    {
4483 		partial_T   *pt = tv->vval.v_partial;
4484 		char_u	    *fname = string_quote(pt == NULL ? NULL
4485 						    : partial_name(pt), FALSE);
4486 		garray_T    ga;
4487 		int	    i;
4488 		char_u	    *tf;
4489 
4490 		ga_init2(&ga, 1, 100);
4491 		ga_concat(&ga, (char_u *)"function(");
4492 		if (fname != NULL)
4493 		{
4494 		    ga_concat(&ga, fname);
4495 		    vim_free(fname);
4496 		}
4497 		if (pt != NULL && pt->pt_argc > 0)
4498 		{
4499 		    ga_concat(&ga, (char_u *)", [");
4500 		    for (i = 0; i < pt->pt_argc; ++i)
4501 		    {
4502 			if (i > 0)
4503 			    ga_concat(&ga, (char_u *)", ");
4504 			ga_concat(&ga,
4505 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
4506 			vim_free(tf);
4507 		    }
4508 		    ga_concat(&ga, (char_u *)"]");
4509 		}
4510 		if (pt != NULL && pt->pt_dict != NULL)
4511 		{
4512 		    typval_T dtv;
4513 
4514 		    ga_concat(&ga, (char_u *)", ");
4515 		    dtv.v_type = VAR_DICT;
4516 		    dtv.vval.v_dict = pt->pt_dict;
4517 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
4518 		    vim_free(tf);
4519 		}
4520 		ga_concat(&ga, (char_u *)")");
4521 
4522 		*tofree = ga.ga_data;
4523 		r = *tofree;
4524 		break;
4525 	    }
4526 
4527 	case VAR_BLOB:
4528 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
4529 	    break;
4530 
4531 	case VAR_LIST:
4532 	    if (tv->vval.v_list == NULL)
4533 	    {
4534 		// NULL list is equivalent to empty list.
4535 		*tofree = NULL;
4536 		r = (char_u *)"[]";
4537 	    }
4538 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
4539 		    && tv->vval.v_list->lv_len > 0)
4540 	    {
4541 		*tofree = NULL;
4542 		r = (char_u *)"[...]";
4543 	    }
4544 	    else
4545 	    {
4546 		int old_copyID = tv->vval.v_list->lv_copyID;
4547 
4548 		tv->vval.v_list->lv_copyID = copyID;
4549 		*tofree = list2string(tv, copyID, restore_copyID);
4550 		if (restore_copyID)
4551 		    tv->vval.v_list->lv_copyID = old_copyID;
4552 		r = *tofree;
4553 	    }
4554 	    break;
4555 
4556 	case VAR_DICT:
4557 	    if (tv->vval.v_dict == NULL)
4558 	    {
4559 		// NULL dict is equivalent to empty dict.
4560 		*tofree = NULL;
4561 		r = (char_u *)"{}";
4562 	    }
4563 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
4564 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
4565 	    {
4566 		*tofree = NULL;
4567 		r = (char_u *)"{...}";
4568 	    }
4569 	    else
4570 	    {
4571 		int old_copyID = tv->vval.v_dict->dv_copyID;
4572 
4573 		tv->vval.v_dict->dv_copyID = copyID;
4574 		*tofree = dict2string(tv, copyID, restore_copyID);
4575 		if (restore_copyID)
4576 		    tv->vval.v_dict->dv_copyID = old_copyID;
4577 		r = *tofree;
4578 	    }
4579 	    break;
4580 
4581 	case VAR_NUMBER:
4582 	case VAR_UNKNOWN:
4583 	case VAR_ANY:
4584 	case VAR_VOID:
4585 	    *tofree = NULL;
4586 	    r = tv_get_string_buf(tv, numbuf);
4587 	    break;
4588 
4589 	case VAR_JOB:
4590 	case VAR_CHANNEL:
4591 	    *tofree = NULL;
4592 	    r = tv_get_string_buf(tv, numbuf);
4593 	    if (composite_val)
4594 	    {
4595 		*tofree = string_quote(r, FALSE);
4596 		r = *tofree;
4597 	    }
4598 	    break;
4599 
4600 	case VAR_FLOAT:
4601 #ifdef FEAT_FLOAT
4602 	    *tofree = NULL;
4603 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
4604 	    r = numbuf;
4605 	    break;
4606 #endif
4607 
4608 	case VAR_BOOL:
4609 	case VAR_SPECIAL:
4610 	    *tofree = NULL;
4611 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
4612 	    break;
4613     }
4614 
4615     if (--recurse == 0)
4616 	did_echo_string_emsg = FALSE;
4617     return r;
4618 }
4619 
4620 /*
4621  * Return a string with the string representation of a variable.
4622  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4623  * "numbuf" is used for a number.
4624  * Does not put quotes around strings, as ":echo" displays values.
4625  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4626  * May return NULL.
4627  */
4628     char_u *
4629 echo_string(
4630     typval_T	*tv,
4631     char_u	**tofree,
4632     char_u	*numbuf,
4633     int		copyID)
4634 {
4635     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
4636 }
4637 
4638 /*
4639  * Return a string with the string representation of a variable.
4640  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4641  * "numbuf" is used for a number.
4642  * Puts quotes around strings, so that they can be parsed back by eval().
4643  * May return NULL.
4644  */
4645     char_u *
4646 tv2string(
4647     typval_T	*tv,
4648     char_u	**tofree,
4649     char_u	*numbuf,
4650     int		copyID)
4651 {
4652     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
4653 }
4654 
4655 /*
4656  * Return string "str" in ' quotes, doubling ' characters.
4657  * If "str" is NULL an empty string is assumed.
4658  * If "function" is TRUE make it function('string').
4659  */
4660     char_u *
4661 string_quote(char_u *str, int function)
4662 {
4663     unsigned	len;
4664     char_u	*p, *r, *s;
4665 
4666     len = (function ? 13 : 3);
4667     if (str != NULL)
4668     {
4669 	len += (unsigned)STRLEN(str);
4670 	for (p = str; *p != NUL; MB_PTR_ADV(p))
4671 	    if (*p == '\'')
4672 		++len;
4673     }
4674     s = r = alloc(len);
4675     if (r != NULL)
4676     {
4677 	if (function)
4678 	{
4679 	    STRCPY(r, "function('");
4680 	    r += 10;
4681 	}
4682 	else
4683 	    *r++ = '\'';
4684 	if (str != NULL)
4685 	    for (p = str; *p != NUL; )
4686 	    {
4687 		if (*p == '\'')
4688 		    *r++ = '\'';
4689 		MB_COPY_CHAR(p, r);
4690 	    }
4691 	*r++ = '\'';
4692 	if (function)
4693 	    *r++ = ')';
4694 	*r++ = NUL;
4695     }
4696     return s;
4697 }
4698 
4699 #if defined(FEAT_FLOAT) || defined(PROTO)
4700 /*
4701  * Convert the string "text" to a floating point number.
4702  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
4703  * this always uses a decimal point.
4704  * Returns the length of the text that was consumed.
4705  */
4706     int
4707 string2float(
4708     char_u	*text,
4709     float_T	*value)	    // result stored here
4710 {
4711     char	*s = (char *)text;
4712     float_T	f;
4713 
4714     // MS-Windows does not deal with "inf" and "nan" properly.
4715     if (STRNICMP(text, "inf", 3) == 0)
4716     {
4717 	*value = INFINITY;
4718 	return 3;
4719     }
4720     if (STRNICMP(text, "-inf", 3) == 0)
4721     {
4722 	*value = -INFINITY;
4723 	return 4;
4724     }
4725     if (STRNICMP(text, "nan", 3) == 0)
4726     {
4727 	*value = NAN;
4728 	return 3;
4729     }
4730     f = strtod(s, &s);
4731     *value = f;
4732     return (int)((char_u *)s - text);
4733 }
4734 #endif
4735 
4736 /*
4737  * Get the value of an environment variable.
4738  * "arg" is pointing to the '$'.  It is advanced to after the name.
4739  * If the environment variable was not set, silently assume it is empty.
4740  * Return FAIL if the name is invalid.
4741  */
4742     int
4743 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
4744 {
4745     char_u	*string = NULL;
4746     int		len;
4747     int		cc;
4748     char_u	*name;
4749     int		mustfree = FALSE;
4750 
4751     ++*arg;
4752     name = *arg;
4753     len = get_env_len(arg);
4754     if (evaluate)
4755     {
4756 	if (len == 0)
4757 	    return FAIL; // invalid empty name
4758 
4759 	cc = name[len];
4760 	name[len] = NUL;
4761 	// first try vim_getenv(), fast for normal environment vars
4762 	string = vim_getenv(name, &mustfree);
4763 	if (string != NULL && *string != NUL)
4764 	{
4765 	    if (!mustfree)
4766 		string = vim_strsave(string);
4767 	}
4768 	else
4769 	{
4770 	    if (mustfree)
4771 		vim_free(string);
4772 
4773 	    // next try expanding things like $VIM and ${HOME}
4774 	    string = expand_env_save(name - 1);
4775 	    if (string != NULL && *string == '$')
4776 		VIM_CLEAR(string);
4777 	}
4778 	name[len] = cc;
4779 
4780 	rettv->v_type = VAR_STRING;
4781 	rettv->vval.v_string = string;
4782     }
4783 
4784     return OK;
4785 }
4786 
4787 /*
4788  * Translate a String variable into a position.
4789  * Returns NULL when there is an error.
4790  */
4791     pos_T *
4792 var2fpos(
4793     typval_T	*varp,
4794     int		dollar_lnum,	// TRUE when $ is last line
4795     int		*fnum)		// set to fnum for '0, 'A, etc.
4796 {
4797     char_u		*name;
4798     static pos_T	pos;
4799     pos_T		*pp;
4800 
4801     // Argument can be [lnum, col, coladd].
4802     if (varp->v_type == VAR_LIST)
4803     {
4804 	list_T		*l;
4805 	int		len;
4806 	int		error = FALSE;
4807 	listitem_T	*li;
4808 
4809 	l = varp->vval.v_list;
4810 	if (l == NULL)
4811 	    return NULL;
4812 
4813 	// Get the line number
4814 	pos.lnum = list_find_nr(l, 0L, &error);
4815 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
4816 	    return NULL;	// invalid line number
4817 
4818 	// Get the column number
4819 	pos.col = list_find_nr(l, 1L, &error);
4820 	if (error)
4821 	    return NULL;
4822 	len = (long)STRLEN(ml_get(pos.lnum));
4823 
4824 	// We accept "$" for the column number: last column.
4825 	li = list_find(l, 1L);
4826 	if (li != NULL && li->li_tv.v_type == VAR_STRING
4827 		&& li->li_tv.vval.v_string != NULL
4828 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
4829 	    pos.col = len + 1;
4830 
4831 	// Accept a position up to the NUL after the line.
4832 	if (pos.col == 0 || (int)pos.col > len + 1)
4833 	    return NULL;	// invalid column number
4834 	--pos.col;
4835 
4836 	// Get the virtual offset.  Defaults to zero.
4837 	pos.coladd = list_find_nr(l, 2L, &error);
4838 	if (error)
4839 	    pos.coladd = 0;
4840 
4841 	return &pos;
4842     }
4843 
4844     name = tv_get_string_chk(varp);
4845     if (name == NULL)
4846 	return NULL;
4847     if (name[0] == '.')				// cursor
4848 	return &curwin->w_cursor;
4849     if (name[0] == 'v' && name[1] == NUL)	// Visual start
4850     {
4851 	if (VIsual_active)
4852 	    return &VIsual;
4853 	return &curwin->w_cursor;
4854     }
4855     if (name[0] == '\'')			// mark
4856     {
4857 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
4858 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
4859 	    return NULL;
4860 	return pp;
4861     }
4862 
4863     pos.coladd = 0;
4864 
4865     if (name[0] == 'w' && dollar_lnum)
4866     {
4867 	pos.col = 0;
4868 	if (name[1] == '0')		// "w0": first visible line
4869 	{
4870 	    update_topline();
4871 	    // In silent Ex mode topline is zero, but that's not a valid line
4872 	    // number; use one instead.
4873 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
4874 	    return &pos;
4875 	}
4876 	else if (name[1] == '$')	// "w$": last visible line
4877 	{
4878 	    validate_botline();
4879 	    // In silent Ex mode botline is zero, return zero then.
4880 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
4881 	    return &pos;
4882 	}
4883     }
4884     else if (name[0] == '$')		// last column or line
4885     {
4886 	if (dollar_lnum)
4887 	{
4888 	    pos.lnum = curbuf->b_ml.ml_line_count;
4889 	    pos.col = 0;
4890 	}
4891 	else
4892 	{
4893 	    pos.lnum = curwin->w_cursor.lnum;
4894 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
4895 	}
4896 	return &pos;
4897     }
4898     return NULL;
4899 }
4900 
4901 /*
4902  * Convert list in "arg" into a position and optional file number.
4903  * When "fnump" is NULL there is no file number, only 3 items.
4904  * Note that the column is passed on as-is, the caller may want to decrement
4905  * it to use 1 for the first column.
4906  * Return FAIL when conversion is not possible, doesn't check the position for
4907  * validity.
4908  */
4909     int
4910 list2fpos(
4911     typval_T	*arg,
4912     pos_T	*posp,
4913     int		*fnump,
4914     colnr_T	*curswantp)
4915 {
4916     list_T	*l = arg->vval.v_list;
4917     long	i = 0;
4918     long	n;
4919 
4920     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
4921     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
4922     if (arg->v_type != VAR_LIST
4923 	    || l == NULL
4924 	    || l->lv_len < (fnump == NULL ? 2 : 3)
4925 	    || l->lv_len > (fnump == NULL ? 4 : 5))
4926 	return FAIL;
4927 
4928     if (fnump != NULL)
4929     {
4930 	n = list_find_nr(l, i++, NULL);	// fnum
4931 	if (n < 0)
4932 	    return FAIL;
4933 	if (n == 0)
4934 	    n = curbuf->b_fnum;		// current buffer
4935 	*fnump = n;
4936     }
4937 
4938     n = list_find_nr(l, i++, NULL);	// lnum
4939     if (n < 0)
4940 	return FAIL;
4941     posp->lnum = n;
4942 
4943     n = list_find_nr(l, i++, NULL);	// col
4944     if (n < 0)
4945 	return FAIL;
4946     posp->col = n;
4947 
4948     n = list_find_nr(l, i, NULL);	// off
4949     if (n < 0)
4950 	posp->coladd = 0;
4951     else
4952 	posp->coladd = n;
4953 
4954     if (curswantp != NULL)
4955 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
4956 
4957     return OK;
4958 }
4959 
4960 /*
4961  * Get the length of an environment variable name.
4962  * Advance "arg" to the first character after the name.
4963  * Return 0 for error.
4964  */
4965     int
4966 get_env_len(char_u **arg)
4967 {
4968     char_u	*p;
4969     int		len;
4970 
4971     for (p = *arg; vim_isIDc(*p); ++p)
4972 	;
4973     if (p == *arg)	    // no name found
4974 	return 0;
4975 
4976     len = (int)(p - *arg);
4977     *arg = p;
4978     return len;
4979 }
4980 
4981 /*
4982  * Get the length of the name of a function or internal variable.
4983  * "arg" is advanced to the first non-white character after the name.
4984  * Return 0 if something is wrong.
4985  */
4986     int
4987 get_id_len(char_u **arg)
4988 {
4989     char_u	*p;
4990     int		len;
4991 
4992     // Find the end of the name.
4993     for (p = *arg; eval_isnamec(*p); ++p)
4994     {
4995 	if (*p == ':')
4996 	{
4997 	    // "s:" is start of "s:var", but "n:" is not and can be used in
4998 	    // slice "[n:]".  Also "xx:" is not a namespace.
4999 	    len = (int)(p - *arg);
5000 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
5001 		    || len > 1)
5002 		break;
5003 	}
5004     }
5005     if (p == *arg)	    // no name found
5006 	return 0;
5007 
5008     len = (int)(p - *arg);
5009     *arg = skipwhite(p);
5010 
5011     return len;
5012 }
5013 
5014 /*
5015  * Get the length of the name of a variable or function.
5016  * Only the name is recognized, does not handle ".key" or "[idx]".
5017  * "arg" is advanced to the first non-white character after the name.
5018  * Return -1 if curly braces expansion failed.
5019  * Return 0 if something else is wrong.
5020  * If the name contains 'magic' {}'s, expand them and return the
5021  * expanded name in an allocated string via 'alias' - caller must free.
5022  */
5023     int
5024 get_name_len(
5025     char_u	**arg,
5026     char_u	**alias,
5027     int		evaluate,
5028     int		verbose)
5029 {
5030     int		len;
5031     char_u	*p;
5032     char_u	*expr_start;
5033     char_u	*expr_end;
5034 
5035     *alias = NULL;  // default to no alias
5036 
5037     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
5038 						  && (*arg)[2] == (int)KE_SNR)
5039     {
5040 	// hard coded <SNR>, already translated
5041 	*arg += 3;
5042 	return get_id_len(arg) + 3;
5043     }
5044     len = eval_fname_script(*arg);
5045     if (len > 0)
5046     {
5047 	// literal "<SID>", "s:" or "<SNR>"
5048 	*arg += len;
5049     }
5050 
5051     /*
5052      * Find the end of the name; check for {} construction.
5053      */
5054     p = find_name_end(*arg, &expr_start, &expr_end,
5055 					       len > 0 ? 0 : FNE_CHECK_START);
5056     if (expr_start != NULL)
5057     {
5058 	char_u	*temp_string;
5059 
5060 	if (!evaluate)
5061 	{
5062 	    len += (int)(p - *arg);
5063 	    *arg = skipwhite(p);
5064 	    return len;
5065 	}
5066 
5067 	/*
5068 	 * Include any <SID> etc in the expanded string:
5069 	 * Thus the -len here.
5070 	 */
5071 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
5072 	if (temp_string == NULL)
5073 	    return -1;
5074 	*alias = temp_string;
5075 	*arg = skipwhite(p);
5076 	return (int)STRLEN(temp_string);
5077     }
5078 
5079     len += get_id_len(arg);
5080     // Only give an error when there is something, otherwise it will be
5081     // reported at a higher level.
5082     if (len == 0 && verbose && **arg != NUL)
5083 	semsg(_(e_invexpr2), *arg);
5084 
5085     return len;
5086 }
5087 
5088 /*
5089  * Find the end of a variable or function name, taking care of magic braces.
5090  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
5091  * start and end of the first magic braces item.
5092  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
5093  * Return a pointer to just after the name.  Equal to "arg" if there is no
5094  * valid name.
5095  */
5096     char_u *
5097 find_name_end(
5098     char_u	*arg,
5099     char_u	**expr_start,
5100     char_u	**expr_end,
5101     int		flags)
5102 {
5103     int		mb_nest = 0;
5104     int		br_nest = 0;
5105     char_u	*p;
5106     int		len;
5107     int		vim9script = current_sctx.sc_version == SCRIPT_VERSION_VIM9;
5108 
5109     if (expr_start != NULL)
5110     {
5111 	*expr_start = NULL;
5112 	*expr_end = NULL;
5113     }
5114 
5115     // Quick check for valid starting character.
5116     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg)
5117 						&& (*arg != '{' || vim9script))
5118 	return arg;
5119 
5120     for (p = arg; *p != NUL
5121 		    && (eval_isnamec(*p)
5122 			|| (*p == '{' && !vim9script)
5123 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
5124 			|| mb_nest != 0
5125 			|| br_nest != 0); MB_PTR_ADV(p))
5126     {
5127 	if (*p == '\'')
5128 	{
5129 	    // skip over 'string' to avoid counting [ and ] inside it.
5130 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5131 		;
5132 	    if (*p == NUL)
5133 		break;
5134 	}
5135 	else if (*p == '"')
5136 	{
5137 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
5138 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5139 		if (*p == '\\' && p[1] != NUL)
5140 		    ++p;
5141 	    if (*p == NUL)
5142 		break;
5143 	}
5144 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5145 	{
5146 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5147 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
5148 	    len = (int)(p - arg);
5149 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5150 		    || (len > 1 && p[-1] != '}'))
5151 		break;
5152 	}
5153 
5154 	if (mb_nest == 0)
5155 	{
5156 	    if (*p == '[')
5157 		++br_nest;
5158 	    else if (*p == ']')
5159 		--br_nest;
5160 	}
5161 
5162 	if (br_nest == 0 && !vim9script)
5163 	{
5164 	    if (*p == '{')
5165 	    {
5166 		mb_nest++;
5167 		if (expr_start != NULL && *expr_start == NULL)
5168 		    *expr_start = p;
5169 	    }
5170 	    else if (*p == '}')
5171 	    {
5172 		mb_nest--;
5173 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5174 		    *expr_end = p;
5175 	    }
5176 	}
5177     }
5178 
5179     return p;
5180 }
5181 
5182 /*
5183  * Expands out the 'magic' {}'s in a variable/function name.
5184  * Note that this can call itself recursively, to deal with
5185  * constructs like foo{bar}{baz}{bam}
5186  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5187  *			"in_start"      ^
5188  *			"expr_start"	   ^
5189  *			"expr_end"		 ^
5190  *			"in_end"			    ^
5191  *
5192  * Returns a new allocated string, which the caller must free.
5193  * Returns NULL for failure.
5194  */
5195     static char_u *
5196 make_expanded_name(
5197     char_u	*in_start,
5198     char_u	*expr_start,
5199     char_u	*expr_end,
5200     char_u	*in_end)
5201 {
5202     char_u	c1;
5203     char_u	*retval = NULL;
5204     char_u	*temp_result;
5205     char_u	*nextcmd = NULL;
5206 
5207     if (expr_end == NULL || in_end == NULL)
5208 	return NULL;
5209     *expr_start	= NUL;
5210     *expr_end = NUL;
5211     c1 = *in_end;
5212     *in_end = NUL;
5213 
5214     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
5215     if (temp_result != NULL && nextcmd == NULL)
5216     {
5217 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5218 						   + (in_end - expr_end) + 1);
5219 	if (retval != NULL)
5220 	{
5221 	    STRCPY(retval, in_start);
5222 	    STRCAT(retval, temp_result);
5223 	    STRCAT(retval, expr_end + 1);
5224 	}
5225     }
5226     vim_free(temp_result);
5227 
5228     *in_end = c1;		// put char back for error messages
5229     *expr_start = '{';
5230     *expr_end = '}';
5231 
5232     if (retval != NULL)
5233     {
5234 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5235 	if (expr_start != NULL)
5236 	{
5237 	    // Further expansion!
5238 	    temp_result = make_expanded_name(retval, expr_start,
5239 						       expr_end, temp_result);
5240 	    vim_free(retval);
5241 	    retval = temp_result;
5242 	}
5243     }
5244 
5245     return retval;
5246 }
5247 
5248 /*
5249  * Return TRUE if character "c" can be used in a variable or function name.
5250  * Does not include '{' or '}' for magic braces.
5251  */
5252     int
5253 eval_isnamec(int c)
5254 {
5255     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
5256 }
5257 
5258 /*
5259  * Return TRUE if character "c" can be used as the first character in a
5260  * variable or function name (excluding '{' and '}').
5261  */
5262     int
5263 eval_isnamec1(int c)
5264 {
5265     return (ASCII_ISALPHA(c) || c == '_');
5266 }
5267 
5268 /*
5269  * Handle:
5270  * - expr[expr], expr[expr:expr] subscript
5271  * - ".name" lookup
5272  * - function call with Funcref variable: func(expr)
5273  * - method call: var->method()
5274  *
5275  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5276  */
5277     int
5278 handle_subscript(
5279     char_u	**arg,
5280     typval_T	*rettv,
5281     int		evaluate,	// do more than finding the end
5282     int		verbose,	// give error messages
5283     char_u	*start_leader,	// start of '!' and '-' prefixes
5284     char_u	**end_leaderp)  // end of '!' and '-' prefixes
5285 {
5286     int		ret = OK;
5287     dict_T	*selfdict = NULL;
5288 
5289     // "." is ".name" lookup when we found a dict or when evaluating and
5290     // scriptversion is at least 2, where string concatenation is "..".
5291     while (ret == OK
5292 	    && (((**arg == '['
5293 		    || (**arg == '.' && (rettv->v_type == VAR_DICT
5294 			|| (!evaluate
5295 			    && (*arg)[1] != '.'
5296 			    && current_sctx.sc_version >= 2)))
5297 		    || (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5298 					    || rettv->v_type == VAR_PARTIAL)))
5299 		&& !VIM_ISWHITE(*(*arg - 1)))
5300 	    || (**arg == '-' && (*arg)[1] == '>')))
5301     {
5302 	if (**arg == '(')
5303 	{
5304 	    ret = call_func_rettv(arg, rettv, evaluate, selfdict, NULL);
5305 
5306 	    // Stop the expression evaluation when immediately aborting on
5307 	    // error, or when an interrupt occurred or an exception was thrown
5308 	    // but not caught.
5309 	    if (aborting())
5310 	    {
5311 		if (ret == OK)
5312 		    clear_tv(rettv);
5313 		ret = FAIL;
5314 	    }
5315 	    dict_unref(selfdict);
5316 	    selfdict = NULL;
5317 	}
5318 	else if (**arg == '-')
5319 	{
5320 	    // Expression "-1.0->method()" applies the leader "-" before
5321 	    // applying ->.
5322 	    if (evaluate && *end_leaderp > start_leader)
5323 		ret = eval7_leader(rettv, start_leader, end_leaderp);
5324 	    if (ret == OK)
5325 	    {
5326 		if ((*arg)[2] == '{')
5327 		    // expr->{lambda}()
5328 		    ret = eval_lambda(arg, rettv, evaluate, verbose);
5329 		else
5330 		    // expr->name()
5331 		    ret = eval_method(arg, rettv, evaluate, verbose);
5332 	    }
5333 	}
5334 	else // **arg == '[' || **arg == '.'
5335 	{
5336 	    dict_unref(selfdict);
5337 	    if (rettv->v_type == VAR_DICT)
5338 	    {
5339 		selfdict = rettv->vval.v_dict;
5340 		if (selfdict != NULL)
5341 		    ++selfdict->dv_refcount;
5342 	    }
5343 	    else
5344 		selfdict = NULL;
5345 	    if (eval_index(arg, rettv, evaluate, verbose) == FAIL)
5346 	    {
5347 		clear_tv(rettv);
5348 		ret = FAIL;
5349 	    }
5350 	}
5351     }
5352 
5353     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5354     // Don't do this when "Func" is already a partial that was bound
5355     // explicitly (pt_auto is FALSE).
5356     if (selfdict != NULL
5357 	    && (rettv->v_type == VAR_FUNC
5358 		|| (rettv->v_type == VAR_PARTIAL
5359 		    && (rettv->vval.v_partial->pt_auto
5360 			|| rettv->vval.v_partial->pt_dict == NULL))))
5361 	selfdict = make_partial(selfdict, rettv);
5362 
5363     dict_unref(selfdict);
5364     return ret;
5365 }
5366 
5367 /*
5368  * Allocate memory for a variable type-value, and make it empty (0 or NULL
5369  * value).
5370  */
5371     typval_T *
5372 alloc_tv(void)
5373 {
5374     return ALLOC_CLEAR_ONE(typval_T);
5375 }
5376 
5377 /*
5378  * Allocate memory for a variable type-value, and assign a string to it.
5379  * The string "s" must have been allocated, it is consumed.
5380  * Return NULL for out of memory, the variable otherwise.
5381  */
5382     typval_T *
5383 alloc_string_tv(char_u *s)
5384 {
5385     typval_T	*rettv;
5386 
5387     rettv = alloc_tv();
5388     if (rettv != NULL)
5389     {
5390 	rettv->v_type = VAR_STRING;
5391 	rettv->vval.v_string = s;
5392     }
5393     else
5394 	vim_free(s);
5395     return rettv;
5396 }
5397 
5398 /*
5399  * Free the memory for a variable type-value.
5400  */
5401     void
5402 free_tv(typval_T *varp)
5403 {
5404     if (varp != NULL)
5405     {
5406 	switch (varp->v_type)
5407 	{
5408 	    case VAR_FUNC:
5409 		func_unref(varp->vval.v_string);
5410 		// FALLTHROUGH
5411 	    case VAR_STRING:
5412 		vim_free(varp->vval.v_string);
5413 		break;
5414 	    case VAR_PARTIAL:
5415 		partial_unref(varp->vval.v_partial);
5416 		break;
5417 	    case VAR_BLOB:
5418 		blob_unref(varp->vval.v_blob);
5419 		break;
5420 	    case VAR_LIST:
5421 		list_unref(varp->vval.v_list);
5422 		break;
5423 	    case VAR_DICT:
5424 		dict_unref(varp->vval.v_dict);
5425 		break;
5426 	    case VAR_JOB:
5427 #ifdef FEAT_JOB_CHANNEL
5428 		job_unref(varp->vval.v_job);
5429 		break;
5430 #endif
5431 	    case VAR_CHANNEL:
5432 #ifdef FEAT_JOB_CHANNEL
5433 		channel_unref(varp->vval.v_channel);
5434 		break;
5435 #endif
5436 	    case VAR_NUMBER:
5437 	    case VAR_FLOAT:
5438 	    case VAR_ANY:
5439 	    case VAR_UNKNOWN:
5440 	    case VAR_VOID:
5441 	    case VAR_BOOL:
5442 	    case VAR_SPECIAL:
5443 		break;
5444 	}
5445 	vim_free(varp);
5446     }
5447 }
5448 
5449 /*
5450  * Free the memory for a variable value and set the value to NULL or 0.
5451  */
5452     void
5453 clear_tv(typval_T *varp)
5454 {
5455     if (varp != NULL)
5456     {
5457 	switch (varp->v_type)
5458 	{
5459 	    case VAR_FUNC:
5460 		func_unref(varp->vval.v_string);
5461 		// FALLTHROUGH
5462 	    case VAR_STRING:
5463 		VIM_CLEAR(varp->vval.v_string);
5464 		break;
5465 	    case VAR_PARTIAL:
5466 		partial_unref(varp->vval.v_partial);
5467 		varp->vval.v_partial = NULL;
5468 		break;
5469 	    case VAR_BLOB:
5470 		blob_unref(varp->vval.v_blob);
5471 		varp->vval.v_blob = NULL;
5472 		break;
5473 	    case VAR_LIST:
5474 		list_unref(varp->vval.v_list);
5475 		varp->vval.v_list = NULL;
5476 		break;
5477 	    case VAR_DICT:
5478 		dict_unref(varp->vval.v_dict);
5479 		varp->vval.v_dict = NULL;
5480 		break;
5481 	    case VAR_NUMBER:
5482 	    case VAR_BOOL:
5483 	    case VAR_SPECIAL:
5484 		varp->vval.v_number = 0;
5485 		break;
5486 	    case VAR_FLOAT:
5487 #ifdef FEAT_FLOAT
5488 		varp->vval.v_float = 0.0;
5489 		break;
5490 #endif
5491 	    case VAR_JOB:
5492 #ifdef FEAT_JOB_CHANNEL
5493 		job_unref(varp->vval.v_job);
5494 		varp->vval.v_job = NULL;
5495 #endif
5496 		break;
5497 	    case VAR_CHANNEL:
5498 #ifdef FEAT_JOB_CHANNEL
5499 		channel_unref(varp->vval.v_channel);
5500 		varp->vval.v_channel = NULL;
5501 #endif
5502 	    case VAR_UNKNOWN:
5503 	    case VAR_ANY:
5504 	    case VAR_VOID:
5505 		break;
5506 	}
5507 	varp->v_lock = 0;
5508     }
5509 }
5510 
5511 /*
5512  * Set the value of a variable to NULL without freeing items.
5513  */
5514     void
5515 init_tv(typval_T *varp)
5516 {
5517     if (varp != NULL)
5518 	CLEAR_POINTER(varp);
5519 }
5520 
5521 /*
5522  * Get the number value of a variable.
5523  * If it is a String variable, uses vim_str2nr().
5524  * For incompatible types, return 0.
5525  * tv_get_number_chk() is similar to tv_get_number(), but informs the
5526  * caller of incompatible types: it sets *denote to TRUE if "denote"
5527  * is not NULL or returns -1 otherwise.
5528  */
5529     varnumber_T
5530 tv_get_number(typval_T *varp)
5531 {
5532     int		error = FALSE;
5533 
5534     return tv_get_number_chk(varp, &error);	// return 0L on error
5535 }
5536 
5537     varnumber_T
5538 tv_get_number_chk(typval_T *varp, int *denote)
5539 {
5540     varnumber_T	n = 0L;
5541 
5542     switch (varp->v_type)
5543     {
5544 	case VAR_NUMBER:
5545 	    return varp->vval.v_number;
5546 	case VAR_FLOAT:
5547 #ifdef FEAT_FLOAT
5548 	    emsg(_("E805: Using a Float as a Number"));
5549 	    break;
5550 #endif
5551 	case VAR_FUNC:
5552 	case VAR_PARTIAL:
5553 	    emsg(_("E703: Using a Funcref as a Number"));
5554 	    break;
5555 	case VAR_STRING:
5556 	    if (varp->vval.v_string != NULL)
5557 		vim_str2nr(varp->vval.v_string, NULL, NULL,
5558 					    STR2NR_ALL, &n, NULL, 0, FALSE);
5559 	    return n;
5560 	case VAR_LIST:
5561 	    emsg(_("E745: Using a List as a Number"));
5562 	    break;
5563 	case VAR_DICT:
5564 	    emsg(_("E728: Using a Dictionary as a Number"));
5565 	    break;
5566 	case VAR_BOOL:
5567 	case VAR_SPECIAL:
5568 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
5569 	case VAR_JOB:
5570 #ifdef FEAT_JOB_CHANNEL
5571 	    emsg(_("E910: Using a Job as a Number"));
5572 	    break;
5573 #endif
5574 	case VAR_CHANNEL:
5575 #ifdef FEAT_JOB_CHANNEL
5576 	    emsg(_("E913: Using a Channel as a Number"));
5577 	    break;
5578 #endif
5579 	case VAR_BLOB:
5580 	    emsg(_("E974: Using a Blob as a Number"));
5581 	    break;
5582 	case VAR_UNKNOWN:
5583 	case VAR_ANY:
5584 	case VAR_VOID:
5585 	    internal_error_no_abort("tv_get_number(UNKNOWN)");
5586 	    break;
5587     }
5588     if (denote == NULL)		// useful for values that must be unsigned
5589 	n = -1;
5590     else
5591 	*denote = TRUE;
5592     return n;
5593 }
5594 
5595 #ifdef FEAT_FLOAT
5596     float_T
5597 tv_get_float(typval_T *varp)
5598 {
5599     switch (varp->v_type)
5600     {
5601 	case VAR_NUMBER:
5602 	    return (float_T)(varp->vval.v_number);
5603 	case VAR_FLOAT:
5604 	    return varp->vval.v_float;
5605 	case VAR_FUNC:
5606 	case VAR_PARTIAL:
5607 	    emsg(_("E891: Using a Funcref as a Float"));
5608 	    break;
5609 	case VAR_STRING:
5610 	    emsg(_("E892: Using a String as a Float"));
5611 	    break;
5612 	case VAR_LIST:
5613 	    emsg(_("E893: Using a List as a Float"));
5614 	    break;
5615 	case VAR_DICT:
5616 	    emsg(_("E894: Using a Dictionary as a Float"));
5617 	    break;
5618 	case VAR_BOOL:
5619 	    emsg(_("E362: Using a boolean value as a Float"));
5620 	    break;
5621 	case VAR_SPECIAL:
5622 	    emsg(_("E907: Using a special value as a Float"));
5623 	    break;
5624 	case VAR_JOB:
5625 # ifdef FEAT_JOB_CHANNEL
5626 	    emsg(_("E911: Using a Job as a Float"));
5627 	    break;
5628 # endif
5629 	case VAR_CHANNEL:
5630 # ifdef FEAT_JOB_CHANNEL
5631 	    emsg(_("E914: Using a Channel as a Float"));
5632 	    break;
5633 # endif
5634 	case VAR_BLOB:
5635 	    emsg(_("E975: Using a Blob as a Float"));
5636 	    break;
5637 	case VAR_UNKNOWN:
5638 	case VAR_ANY:
5639 	case VAR_VOID:
5640 	    internal_error_no_abort("tv_get_float(UNKNOWN)");
5641 	    break;
5642     }
5643     return 0;
5644 }
5645 #endif
5646 
5647 /*
5648  * Get the string value of a variable.
5649  * If it is a Number variable, the number is converted into a string.
5650  * tv_get_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
5651  * tv_get_string_buf() uses a given buffer.
5652  * If the String variable has never been set, return an empty string.
5653  * Never returns NULL;
5654  * tv_get_string_chk() and tv_get_string_buf_chk() are similar, but return
5655  * NULL on error.
5656  */
5657     char_u *
5658 tv_get_string(typval_T *varp)
5659 {
5660     static char_u   mybuf[NUMBUFLEN];
5661 
5662     return tv_get_string_buf(varp, mybuf);
5663 }
5664 
5665     char_u *
5666 tv_get_string_buf(typval_T *varp, char_u *buf)
5667 {
5668     char_u	*res =  tv_get_string_buf_chk(varp, buf);
5669 
5670     return res != NULL ? res : (char_u *)"";
5671 }
5672 
5673 /*
5674  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
5675  */
5676     char_u *
5677 tv_get_string_chk(typval_T *varp)
5678 {
5679     static char_u   mybuf[NUMBUFLEN];
5680 
5681     return tv_get_string_buf_chk(varp, mybuf);
5682 }
5683 
5684     char_u *
5685 tv_get_string_buf_chk(typval_T *varp, char_u *buf)
5686 {
5687     switch (varp->v_type)
5688     {
5689 	case VAR_NUMBER:
5690 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
5691 					    (varnumber_T)varp->vval.v_number);
5692 	    return buf;
5693 	case VAR_FUNC:
5694 	case VAR_PARTIAL:
5695 	    emsg(_("E729: using Funcref as a String"));
5696 	    break;
5697 	case VAR_LIST:
5698 	    emsg(_("E730: using List as a String"));
5699 	    break;
5700 	case VAR_DICT:
5701 	    emsg(_("E731: using Dictionary as a String"));
5702 	    break;
5703 	case VAR_FLOAT:
5704 #ifdef FEAT_FLOAT
5705 	    emsg(_(e_float_as_string));
5706 	    break;
5707 #endif
5708 	case VAR_STRING:
5709 	    if (varp->vval.v_string != NULL)
5710 		return varp->vval.v_string;
5711 	    return (char_u *)"";
5712 	case VAR_BOOL:
5713 	case VAR_SPECIAL:
5714 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
5715 	    return buf;
5716         case VAR_BLOB:
5717 	    emsg(_("E976: using Blob as a String"));
5718 	    break;
5719 	case VAR_JOB:
5720 #ifdef FEAT_JOB_CHANNEL
5721 	    {
5722 		job_T *job = varp->vval.v_job;
5723 		char  *status;
5724 
5725 		if (job == NULL)
5726 		    return (char_u *)"no process";
5727 		status = job->jv_status == JOB_FAILED ? "fail"
5728 				: job->jv_status >= JOB_ENDED ? "dead"
5729 				: "run";
5730 # ifdef UNIX
5731 		vim_snprintf((char *)buf, NUMBUFLEN,
5732 			    "process %ld %s", (long)job->jv_pid, status);
5733 # elif defined(MSWIN)
5734 		vim_snprintf((char *)buf, NUMBUFLEN,
5735 			    "process %ld %s",
5736 			    (long)job->jv_proc_info.dwProcessId,
5737 			    status);
5738 # else
5739 		// fall-back
5740 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
5741 # endif
5742 		return buf;
5743 	    }
5744 #endif
5745 	    break;
5746 	case VAR_CHANNEL:
5747 #ifdef FEAT_JOB_CHANNEL
5748 	    {
5749 		channel_T *channel = varp->vval.v_channel;
5750 		char      *status = channel_status(channel, -1);
5751 
5752 		if (channel == NULL)
5753 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
5754 		else
5755 		    vim_snprintf((char *)buf, NUMBUFLEN,
5756 				     "channel %d %s", channel->ch_id, status);
5757 		return buf;
5758 	    }
5759 #endif
5760 	    break;
5761 	case VAR_UNKNOWN:
5762 	case VAR_ANY:
5763 	case VAR_VOID:
5764 	    emsg(_(e_inval_string));
5765 	    break;
5766     }
5767     return NULL;
5768 }
5769 
5770 /*
5771  * Turn a typeval into a string.  Similar to tv_get_string_buf() but uses
5772  * string() on Dict, List, etc.
5773  */
5774     static char_u *
5775 tv_stringify(typval_T *varp, char_u *buf)
5776 {
5777     if (varp->v_type == VAR_LIST
5778 	    || varp->v_type == VAR_DICT
5779 	    || varp->v_type == VAR_BLOB
5780 	    || varp->v_type == VAR_FUNC
5781 	    || varp->v_type == VAR_PARTIAL
5782 	    || varp->v_type == VAR_FLOAT)
5783     {
5784 	typval_T tmp;
5785 
5786 	f_string(varp, &tmp);
5787 	tv_get_string_buf(&tmp, buf);
5788 	clear_tv(varp);
5789 	*varp = tmp;
5790 	return tmp.vval.v_string;
5791     }
5792     return tv_get_string_buf(varp, buf);
5793 }
5794 
5795 /*
5796  * Return TRUE if typeval "tv" and its value are set to be locked (immutable).
5797  * Also give an error message, using "name" or _("name") when use_gettext is
5798  * TRUE.
5799  */
5800     static int
5801 tv_check_lock(typval_T *tv, char_u *name, int use_gettext)
5802 {
5803     int	lock = 0;
5804 
5805     switch (tv->v_type)
5806     {
5807 	case VAR_BLOB:
5808 	    if (tv->vval.v_blob != NULL)
5809 		lock = tv->vval.v_blob->bv_lock;
5810 	    break;
5811 	case VAR_LIST:
5812 	    if (tv->vval.v_list != NULL)
5813 		lock = tv->vval.v_list->lv_lock;
5814 	    break;
5815 	case VAR_DICT:
5816 	    if (tv->vval.v_dict != NULL)
5817 		lock = tv->vval.v_dict->dv_lock;
5818 	    break;
5819 	default:
5820 	    break;
5821     }
5822     return var_check_lock(tv->v_lock, name, use_gettext)
5823 		    || (lock != 0 && var_check_lock(lock, name, use_gettext));
5824 }
5825 
5826 /*
5827  * Copy the values from typval_T "from" to typval_T "to".
5828  * When needed allocates string or increases reference count.
5829  * Does not make a copy of a list, blob or dict but copies the reference!
5830  * It is OK for "from" and "to" to point to the same item.  This is used to
5831  * make a copy later.
5832  */
5833     void
5834 copy_tv(typval_T *from, typval_T *to)
5835 {
5836     to->v_type = from->v_type;
5837     to->v_lock = 0;
5838     switch (from->v_type)
5839     {
5840 	case VAR_NUMBER:
5841 	case VAR_BOOL:
5842 	case VAR_SPECIAL:
5843 	    to->vval.v_number = from->vval.v_number;
5844 	    break;
5845 	case VAR_FLOAT:
5846 #ifdef FEAT_FLOAT
5847 	    to->vval.v_float = from->vval.v_float;
5848 	    break;
5849 #endif
5850 	case VAR_JOB:
5851 #ifdef FEAT_JOB_CHANNEL
5852 	    to->vval.v_job = from->vval.v_job;
5853 	    if (to->vval.v_job != NULL)
5854 		++to->vval.v_job->jv_refcount;
5855 	    break;
5856 #endif
5857 	case VAR_CHANNEL:
5858 #ifdef FEAT_JOB_CHANNEL
5859 	    to->vval.v_channel = from->vval.v_channel;
5860 	    if (to->vval.v_channel != NULL)
5861 		++to->vval.v_channel->ch_refcount;
5862 	    break;
5863 #endif
5864 	case VAR_STRING:
5865 	case VAR_FUNC:
5866 	    if (from->vval.v_string == NULL)
5867 		to->vval.v_string = NULL;
5868 	    else
5869 	    {
5870 		to->vval.v_string = vim_strsave(from->vval.v_string);
5871 		if (from->v_type == VAR_FUNC)
5872 		    func_ref(to->vval.v_string);
5873 	    }
5874 	    break;
5875 	case VAR_PARTIAL:
5876 	    if (from->vval.v_partial == NULL)
5877 		to->vval.v_partial = NULL;
5878 	    else
5879 	    {
5880 		to->vval.v_partial = from->vval.v_partial;
5881 		++to->vval.v_partial->pt_refcount;
5882 	    }
5883 	    break;
5884 	case VAR_BLOB:
5885 	    if (from->vval.v_blob == NULL)
5886 		to->vval.v_blob = NULL;
5887 	    else
5888 	    {
5889 		to->vval.v_blob = from->vval.v_blob;
5890 		++to->vval.v_blob->bv_refcount;
5891 	    }
5892 	    break;
5893 	case VAR_LIST:
5894 	    if (from->vval.v_list == NULL)
5895 		to->vval.v_list = NULL;
5896 	    else
5897 	    {
5898 		to->vval.v_list = from->vval.v_list;
5899 		++to->vval.v_list->lv_refcount;
5900 	    }
5901 	    break;
5902 	case VAR_DICT:
5903 	    if (from->vval.v_dict == NULL)
5904 		to->vval.v_dict = NULL;
5905 	    else
5906 	    {
5907 		to->vval.v_dict = from->vval.v_dict;
5908 		++to->vval.v_dict->dv_refcount;
5909 	    }
5910 	    break;
5911 	case VAR_UNKNOWN:
5912 	case VAR_ANY:
5913 	case VAR_VOID:
5914 	    internal_error_no_abort("copy_tv(UNKNOWN)");
5915 	    break;
5916     }
5917 }
5918 
5919 /*
5920  * Make a copy of an item.
5921  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5922  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5923  * reference to an already copied list/dict can be used.
5924  * Returns FAIL or OK.
5925  */
5926     int
5927 item_copy(
5928     typval_T	*from,
5929     typval_T	*to,
5930     int		deep,
5931     int		copyID)
5932 {
5933     static int	recurse = 0;
5934     int		ret = OK;
5935 
5936     if (recurse >= DICT_MAXNEST)
5937     {
5938 	emsg(_("E698: variable nested too deep for making a copy"));
5939 	return FAIL;
5940     }
5941     ++recurse;
5942 
5943     switch (from->v_type)
5944     {
5945 	case VAR_NUMBER:
5946 	case VAR_FLOAT:
5947 	case VAR_STRING:
5948 	case VAR_FUNC:
5949 	case VAR_PARTIAL:
5950 	case VAR_BOOL:
5951 	case VAR_SPECIAL:
5952 	case VAR_JOB:
5953 	case VAR_CHANNEL:
5954 	    copy_tv(from, to);
5955 	    break;
5956 	case VAR_LIST:
5957 	    to->v_type = VAR_LIST;
5958 	    to->v_lock = 0;
5959 	    if (from->vval.v_list == NULL)
5960 		to->vval.v_list = NULL;
5961 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
5962 	    {
5963 		// use the copy made earlier
5964 		to->vval.v_list = from->vval.v_list->lv_copylist;
5965 		++to->vval.v_list->lv_refcount;
5966 	    }
5967 	    else
5968 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
5969 	    if (to->vval.v_list == NULL)
5970 		ret = FAIL;
5971 	    break;
5972 	case VAR_BLOB:
5973 	    ret = blob_copy(from->vval.v_blob, to);
5974 	    break;
5975 	case VAR_DICT:
5976 	    to->v_type = VAR_DICT;
5977 	    to->v_lock = 0;
5978 	    if (from->vval.v_dict == NULL)
5979 		to->vval.v_dict = NULL;
5980 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
5981 	    {
5982 		// use the copy made earlier
5983 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
5984 		++to->vval.v_dict->dv_refcount;
5985 	    }
5986 	    else
5987 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
5988 	    if (to->vval.v_dict == NULL)
5989 		ret = FAIL;
5990 	    break;
5991 	case VAR_UNKNOWN:
5992 	case VAR_ANY:
5993 	case VAR_VOID:
5994 	    internal_error_no_abort("item_copy(UNKNOWN)");
5995 	    ret = FAIL;
5996     }
5997     --recurse;
5998     return ret;
5999 }
6000 
6001     void
6002 echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr)
6003 {
6004     char_u	*tofree;
6005     char_u	numbuf[NUMBUFLEN];
6006     char_u	*p = echo_string(rettv, &tofree, numbuf, get_copyID());
6007 
6008     if (*atstart)
6009     {
6010 	*atstart = FALSE;
6011 	// Call msg_start() after eval1(), evaluating the expression
6012 	// may cause a message to appear.
6013 	if (with_space)
6014 	{
6015 	    // Mark the saved text as finishing the line, so that what
6016 	    // follows is displayed on a new line when scrolling back
6017 	    // at the more prompt.
6018 	    msg_sb_eol();
6019 	    msg_start();
6020 	}
6021     }
6022     else if (with_space)
6023 	msg_puts_attr(" ", echo_attr);
6024 
6025     if (p != NULL)
6026 	for ( ; *p != NUL && !got_int; ++p)
6027 	{
6028 	    if (*p == '\n' || *p == '\r' || *p == TAB)
6029 	    {
6030 		if (*p != TAB && *needclr)
6031 		{
6032 		    // remove any text still there from the command
6033 		    msg_clr_eos();
6034 		    *needclr = FALSE;
6035 		}
6036 		msg_putchar_attr(*p, echo_attr);
6037 	    }
6038 	    else
6039 	    {
6040 		if (has_mbyte)
6041 		{
6042 		    int i = (*mb_ptr2len)(p);
6043 
6044 		    (void)msg_outtrans_len_attr(p, i, echo_attr);
6045 		    p += i - 1;
6046 		}
6047 		else
6048 		    (void)msg_outtrans_len_attr(p, 1, echo_attr);
6049 	    }
6050 	}
6051     vim_free(tofree);
6052 }
6053 
6054 /*
6055  * ":echo expr1 ..."	print each argument separated with a space, add a
6056  *			newline at the end.
6057  * ":echon expr1 ..."	print each argument plain.
6058  */
6059     void
6060 ex_echo(exarg_T *eap)
6061 {
6062     char_u	*arg = eap->arg;
6063     typval_T	rettv;
6064     char_u	*p;
6065     int		needclr = TRUE;
6066     int		atstart = TRUE;
6067     int		did_emsg_before = did_emsg;
6068     int		called_emsg_before = called_emsg;
6069 
6070     if (eap->skip)
6071 	++emsg_skip;
6072     while ((!ends_excmd2(eap->cmd, arg) || *arg == '"') && !got_int)
6073     {
6074 	// If eval1() causes an error message the text from the command may
6075 	// still need to be cleared. E.g., "echo 22,44".
6076 	need_clr_eos = needclr;
6077 
6078 	p = arg;
6079 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
6080 	{
6081 	    /*
6082 	     * Report the invalid expression unless the expression evaluation
6083 	     * has been cancelled due to an aborting error, an interrupt, or an
6084 	     * exception.
6085 	     */
6086 	    if (!aborting() && did_emsg == did_emsg_before
6087 					  && called_emsg == called_emsg_before)
6088 		semsg(_(e_invexpr2), p);
6089 	    need_clr_eos = FALSE;
6090 	    break;
6091 	}
6092 	need_clr_eos = FALSE;
6093 
6094 	if (!eap->skip)
6095 	    echo_one(&rettv, eap->cmdidx == CMD_echo, &atstart, &needclr);
6096 
6097 	clear_tv(&rettv);
6098 	arg = skipwhite(arg);
6099     }
6100     eap->nextcmd = check_nextcmd(arg);
6101 
6102     if (eap->skip)
6103 	--emsg_skip;
6104     else
6105     {
6106 	// remove text that may still be there from the command
6107 	if (needclr)
6108 	    msg_clr_eos();
6109 	if (eap->cmdidx == CMD_echo)
6110 	    msg_end();
6111     }
6112 }
6113 
6114 /*
6115  * ":echohl {name}".
6116  */
6117     void
6118 ex_echohl(exarg_T *eap)
6119 {
6120     echo_attr = syn_name2attr(eap->arg);
6121 }
6122 
6123 /*
6124  * Returns the :echo attribute
6125  */
6126     int
6127 get_echo_attr(void)
6128 {
6129     return echo_attr;
6130 }
6131 
6132 /*
6133  * ":execute expr1 ..."	execute the result of an expression.
6134  * ":echomsg expr1 ..."	Print a message
6135  * ":echoerr expr1 ..."	Print an error
6136  * Each gets spaces around each argument and a newline at the end for
6137  * echo commands
6138  */
6139     void
6140 ex_execute(exarg_T *eap)
6141 {
6142     char_u	*arg = eap->arg;
6143     typval_T	rettv;
6144     int		ret = OK;
6145     char_u	*p;
6146     garray_T	ga;
6147     int		len;
6148     int		save_did_emsg;
6149 
6150     ga_init2(&ga, 1, 80);
6151 
6152     if (eap->skip)
6153 	++emsg_skip;
6154     while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
6155     {
6156 	ret = eval1_emsg(&arg, &rettv, !eap->skip);
6157 	if (ret == FAIL)
6158 	    break;
6159 
6160 	if (!eap->skip)
6161 	{
6162 	    char_u   buf[NUMBUFLEN];
6163 
6164 	    if (eap->cmdidx == CMD_execute)
6165 	    {
6166 		if (rettv.v_type == VAR_CHANNEL || rettv.v_type == VAR_JOB)
6167 		{
6168 		    emsg(_(e_inval_string));
6169 		    p = NULL;
6170 		}
6171 		else
6172 		    p = tv_get_string_buf(&rettv, buf);
6173 	    }
6174 	    else
6175 		p = tv_stringify(&rettv, buf);
6176 	    if (p == NULL)
6177 	    {
6178 		clear_tv(&rettv);
6179 		ret = FAIL;
6180 		break;
6181 	    }
6182 	    len = (int)STRLEN(p);
6183 	    if (ga_grow(&ga, len + 2) == FAIL)
6184 	    {
6185 		clear_tv(&rettv);
6186 		ret = FAIL;
6187 		break;
6188 	    }
6189 	    if (ga.ga_len)
6190 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
6191 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
6192 	    ga.ga_len += len;
6193 	}
6194 
6195 	clear_tv(&rettv);
6196 	arg = skipwhite(arg);
6197     }
6198 
6199     if (ret != FAIL && ga.ga_data != NULL)
6200     {
6201 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
6202 	{
6203 	    // Mark the already saved text as finishing the line, so that what
6204 	    // follows is displayed on a new line when scrolling back at the
6205 	    // more prompt.
6206 	    msg_sb_eol();
6207 	}
6208 
6209 	if (eap->cmdidx == CMD_echomsg)
6210 	{
6211 	    msg_attr(ga.ga_data, echo_attr);
6212 	    out_flush();
6213 	}
6214 	else if (eap->cmdidx == CMD_echoerr)
6215 	{
6216 	    // We don't want to abort following commands, restore did_emsg.
6217 	    save_did_emsg = did_emsg;
6218 	    emsg(ga.ga_data);
6219 	    if (!force_abort)
6220 		did_emsg = save_did_emsg;
6221 	}
6222 	else if (eap->cmdidx == CMD_execute)
6223 	    do_cmdline((char_u *)ga.ga_data,
6224 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
6225     }
6226 
6227     ga_clear(&ga);
6228 
6229     if (eap->skip)
6230 	--emsg_skip;
6231 
6232     eap->nextcmd = check_nextcmd(arg);
6233 }
6234 
6235 /*
6236  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
6237  * "arg" points to the "&" or '+' when called, to "option" when returning.
6238  * Returns NULL when no option name found.  Otherwise pointer to the char
6239  * after the option name.
6240  */
6241     char_u *
6242 find_option_end(char_u **arg, int *opt_flags)
6243 {
6244     char_u	*p = *arg;
6245 
6246     ++p;
6247     if (*p == 'g' && p[1] == ':')
6248     {
6249 	*opt_flags = OPT_GLOBAL;
6250 	p += 2;
6251     }
6252     else if (*p == 'l' && p[1] == ':')
6253     {
6254 	*opt_flags = OPT_LOCAL;
6255 	p += 2;
6256     }
6257     else
6258 	*opt_flags = 0;
6259 
6260     if (!ASCII_ISALPHA(*p))
6261 	return NULL;
6262     *arg = p;
6263 
6264     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
6265 	p += 4;	    // termcap option
6266     else
6267 	while (ASCII_ISALPHA(*p))
6268 	    ++p;
6269     return p;
6270 }
6271 
6272 /*
6273  * Display script name where an item was last set.
6274  * Should only be invoked when 'verbose' is non-zero.
6275  */
6276     void
6277 last_set_msg(sctx_T script_ctx)
6278 {
6279     char_u *p;
6280 
6281     if (script_ctx.sc_sid != 0)
6282     {
6283 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
6284 	if (p != NULL)
6285 	{
6286 	    verbose_enter();
6287 	    msg_puts(_("\n\tLast set from "));
6288 	    msg_puts((char *)p);
6289 	    if (script_ctx.sc_lnum > 0)
6290 	    {
6291 		msg_puts(_(line_msg));
6292 		msg_outnum((long)script_ctx.sc_lnum);
6293 	    }
6294 	    verbose_leave();
6295 	    vim_free(p);
6296 	}
6297     }
6298 }
6299 
6300 /*
6301  * Compare "typ1" and "typ2".  Put the result in "typ1".
6302  */
6303     int
6304 typval_compare(
6305     typval_T	*typ1,   // first operand
6306     typval_T	*typ2,   // second operand
6307     exptype_T	type,    // operator
6308     int		ic)      // ignore case
6309 {
6310     int		i;
6311     varnumber_T	n1, n2;
6312     char_u	*s1, *s2;
6313     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
6314     int		type_is = type == EXPR_IS || type == EXPR_ISNOT;
6315 
6316     if (type_is && typ1->v_type != typ2->v_type)
6317     {
6318 	// For "is" a different type always means FALSE, for "notis"
6319 	// it means TRUE.
6320 	n1 = (type == EXPR_ISNOT);
6321     }
6322     else if (typ1->v_type == VAR_BLOB || typ2->v_type == VAR_BLOB)
6323     {
6324 	if (type_is)
6325 	{
6326 	    n1 = (typ1->v_type == typ2->v_type
6327 			    && typ1->vval.v_blob == typ2->vval.v_blob);
6328 	    if (type == EXPR_ISNOT)
6329 		n1 = !n1;
6330 	}
6331 	else if (typ1->v_type != typ2->v_type
6332 		|| (type != EXPR_EQUAL && type != EXPR_NEQUAL))
6333 	{
6334 	    if (typ1->v_type != typ2->v_type)
6335 		emsg(_("E977: Can only compare Blob with Blob"));
6336 	    else
6337 		emsg(_(e_invalblob));
6338 	    clear_tv(typ1);
6339 	    return FAIL;
6340 	}
6341 	else
6342 	{
6343 	    // Compare two Blobs for being equal or unequal.
6344 	    n1 = blob_equal(typ1->vval.v_blob, typ2->vval.v_blob);
6345 	    if (type == EXPR_NEQUAL)
6346 		n1 = !n1;
6347 	}
6348     }
6349     else if (typ1->v_type == VAR_LIST || typ2->v_type == VAR_LIST)
6350     {
6351 	if (type_is)
6352 	{
6353 	    n1 = (typ1->v_type == typ2->v_type
6354 			    && typ1->vval.v_list == typ2->vval.v_list);
6355 	    if (type == EXPR_ISNOT)
6356 		n1 = !n1;
6357 	}
6358 	else if (typ1->v_type != typ2->v_type
6359 		|| (type != EXPR_EQUAL && type != EXPR_NEQUAL))
6360 	{
6361 	    if (typ1->v_type != typ2->v_type)
6362 		emsg(_("E691: Can only compare List with List"));
6363 	    else
6364 		emsg(_("E692: Invalid operation for List"));
6365 	    clear_tv(typ1);
6366 	    return FAIL;
6367 	}
6368 	else
6369 	{
6370 	    // Compare two Lists for being equal or unequal.
6371 	    n1 = list_equal(typ1->vval.v_list, typ2->vval.v_list,
6372 							    ic, FALSE);
6373 	    if (type == EXPR_NEQUAL)
6374 		n1 = !n1;
6375 	}
6376     }
6377 
6378     else if (typ1->v_type == VAR_DICT || typ2->v_type == VAR_DICT)
6379     {
6380 	if (type_is)
6381 	{
6382 	    n1 = (typ1->v_type == typ2->v_type
6383 			    && typ1->vval.v_dict == typ2->vval.v_dict);
6384 	    if (type == EXPR_ISNOT)
6385 		n1 = !n1;
6386 	}
6387 	else if (typ1->v_type != typ2->v_type
6388 		|| (type != EXPR_EQUAL && type != EXPR_NEQUAL))
6389 	{
6390 	    if (typ1->v_type != typ2->v_type)
6391 		emsg(_("E735: Can only compare Dictionary with Dictionary"));
6392 	    else
6393 		emsg(_("E736: Invalid operation for Dictionary"));
6394 	    clear_tv(typ1);
6395 	    return FAIL;
6396 	}
6397 	else
6398 	{
6399 	    // Compare two Dictionaries for being equal or unequal.
6400 	    n1 = dict_equal(typ1->vval.v_dict, typ2->vval.v_dict,
6401 							    ic, FALSE);
6402 	    if (type == EXPR_NEQUAL)
6403 		n1 = !n1;
6404 	}
6405     }
6406 
6407     else if (typ1->v_type == VAR_FUNC || typ2->v_type == VAR_FUNC
6408 	|| typ1->v_type == VAR_PARTIAL || typ2->v_type == VAR_PARTIAL)
6409     {
6410 	if (type != EXPR_EQUAL && type != EXPR_NEQUAL
6411 		&& type != EXPR_IS && type != EXPR_ISNOT)
6412 	{
6413 	    emsg(_("E694: Invalid operation for Funcrefs"));
6414 	    clear_tv(typ1);
6415 	    return FAIL;
6416 	}
6417 	if ((typ1->v_type == VAR_PARTIAL
6418 					&& typ1->vval.v_partial == NULL)
6419 		|| (typ2->v_type == VAR_PARTIAL
6420 					&& typ2->vval.v_partial == NULL))
6421 	    // when a partial is NULL assume not equal
6422 	    n1 = FALSE;
6423 	else if (type_is)
6424 	{
6425 	    if (typ1->v_type == VAR_FUNC && typ2->v_type == VAR_FUNC)
6426 		// strings are considered the same if their value is
6427 		// the same
6428 		n1 = tv_equal(typ1, typ2, ic, FALSE);
6429 	    else if (typ1->v_type == VAR_PARTIAL
6430 					&& typ2->v_type == VAR_PARTIAL)
6431 		n1 = (typ1->vval.v_partial == typ2->vval.v_partial);
6432 	    else
6433 		n1 = FALSE;
6434 	}
6435 	else
6436 	    n1 = tv_equal(typ1, typ2, ic, FALSE);
6437 	if (type == EXPR_NEQUAL || type == EXPR_ISNOT)
6438 	    n1 = !n1;
6439     }
6440 
6441 #ifdef FEAT_FLOAT
6442     /*
6443 	* If one of the two variables is a float, compare as a float.
6444 	* When using "=~" or "!~", always compare as string.
6445 	*/
6446     else if ((typ1->v_type == VAR_FLOAT || typ2->v_type == VAR_FLOAT)
6447 	    && type != EXPR_MATCH && type != EXPR_NOMATCH)
6448     {
6449 	float_T f1, f2;
6450 
6451 	f1 = tv_get_float(typ1);
6452 	f2 = tv_get_float(typ2);
6453 	n1 = FALSE;
6454 	switch (type)
6455 	{
6456 	    case EXPR_IS:
6457 	    case EXPR_EQUAL:    n1 = (f1 == f2); break;
6458 	    case EXPR_ISNOT:
6459 	    case EXPR_NEQUAL:   n1 = (f1 != f2); break;
6460 	    case EXPR_GREATER:  n1 = (f1 > f2); break;
6461 	    case EXPR_GEQUAL:   n1 = (f1 >= f2); break;
6462 	    case EXPR_SMALLER:  n1 = (f1 < f2); break;
6463 	    case EXPR_SEQUAL:   n1 = (f1 <= f2); break;
6464 	    case EXPR_UNKNOWN:
6465 	    case EXPR_MATCH:
6466 	    default:  break;  // avoid gcc warning
6467 	}
6468     }
6469 #endif
6470 
6471     /*
6472      * If one of the two variables is a number, compare as a number.
6473      * When using "=~" or "!~", always compare as string.
6474      */
6475     else if ((typ1->v_type == VAR_NUMBER || typ2->v_type == VAR_NUMBER)
6476 	    && type != EXPR_MATCH && type != EXPR_NOMATCH)
6477     {
6478 	n1 = tv_get_number(typ1);
6479 	n2 = tv_get_number(typ2);
6480 	switch (type)
6481 	{
6482 	    case EXPR_IS:
6483 	    case EXPR_EQUAL:    n1 = (n1 == n2); break;
6484 	    case EXPR_ISNOT:
6485 	    case EXPR_NEQUAL:   n1 = (n1 != n2); break;
6486 	    case EXPR_GREATER:  n1 = (n1 > n2); break;
6487 	    case EXPR_GEQUAL:   n1 = (n1 >= n2); break;
6488 	    case EXPR_SMALLER:  n1 = (n1 < n2); break;
6489 	    case EXPR_SEQUAL:   n1 = (n1 <= n2); break;
6490 	    case EXPR_UNKNOWN:
6491 	    case EXPR_MATCH:
6492 	    default:  break;  // avoid gcc warning
6493 	}
6494     }
6495     else
6496     {
6497 	s1 = tv_get_string_buf(typ1, buf1);
6498 	s2 = tv_get_string_buf(typ2, buf2);
6499 	if (type != EXPR_MATCH && type != EXPR_NOMATCH)
6500 	    i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
6501 	else
6502 	    i = 0;
6503 	n1 = FALSE;
6504 	switch (type)
6505 	{
6506 	    case EXPR_IS:
6507 	    case EXPR_EQUAL:    n1 = (i == 0); break;
6508 	    case EXPR_ISNOT:
6509 	    case EXPR_NEQUAL:   n1 = (i != 0); break;
6510 	    case EXPR_GREATER:  n1 = (i > 0); break;
6511 	    case EXPR_GEQUAL:   n1 = (i >= 0); break;
6512 	    case EXPR_SMALLER:  n1 = (i < 0); break;
6513 	    case EXPR_SEQUAL:   n1 = (i <= 0); break;
6514 
6515 	    case EXPR_MATCH:
6516 	    case EXPR_NOMATCH:
6517 		    n1 = pattern_match(s2, s1, ic);
6518 		    if (type == EXPR_NOMATCH)
6519 			n1 = !n1;
6520 		    break;
6521 
6522 	    default:  break;  // avoid gcc warning
6523 	}
6524     }
6525     clear_tv(typ1);
6526     typ1->v_type = VAR_NUMBER;
6527     typ1->vval.v_number = n1;
6528 
6529     return OK;
6530 }
6531 
6532     char_u *
6533 typval_tostring(typval_T *arg)
6534 {
6535     char_u	*tofree;
6536     char_u	numbuf[NUMBUFLEN];
6537     char_u	*ret = NULL;
6538 
6539     if (arg == NULL)
6540 	return vim_strsave((char_u *)"(does not exist)");
6541     ret = tv2string(arg, &tofree, numbuf, 0);
6542     // Make a copy if we have a value but it's not in allocated memory.
6543     if (ret != NULL && tofree == NULL)
6544 	ret = vim_strsave(ret);
6545     return ret;
6546 }
6547 
6548 #endif // FEAT_EVAL
6549 
6550 /*
6551  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
6552  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
6553  * "flags" can be "g" to do a global substitute.
6554  * Returns an allocated string, NULL for error.
6555  */
6556     char_u *
6557 do_string_sub(
6558     char_u	*str,
6559     char_u	*pat,
6560     char_u	*sub,
6561     typval_T	*expr,
6562     char_u	*flags)
6563 {
6564     int		sublen;
6565     regmatch_T	regmatch;
6566     int		i;
6567     int		do_all;
6568     char_u	*tail;
6569     char_u	*end;
6570     garray_T	ga;
6571     char_u	*ret;
6572     char_u	*save_cpo;
6573     char_u	*zero_width = NULL;
6574 
6575     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
6576     save_cpo = p_cpo;
6577     p_cpo = empty_option;
6578 
6579     ga_init2(&ga, 1, 200);
6580 
6581     do_all = (flags[0] == 'g');
6582 
6583     regmatch.rm_ic = p_ic;
6584     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
6585     if (regmatch.regprog != NULL)
6586     {
6587 	tail = str;
6588 	end = str + STRLEN(str);
6589 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
6590 	{
6591 	    // Skip empty match except for first match.
6592 	    if (regmatch.startp[0] == regmatch.endp[0])
6593 	    {
6594 		if (zero_width == regmatch.startp[0])
6595 		{
6596 		    // avoid getting stuck on a match with an empty string
6597 		    i = mb_ptr2len(tail);
6598 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
6599 								   (size_t)i);
6600 		    ga.ga_len += i;
6601 		    tail += i;
6602 		    continue;
6603 		}
6604 		zero_width = regmatch.startp[0];
6605 	    }
6606 
6607 	    /*
6608 	     * Get some space for a temporary buffer to do the substitution
6609 	     * into.  It will contain:
6610 	     * - The text up to where the match is.
6611 	     * - The substituted text.
6612 	     * - The text after the match.
6613 	     */
6614 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
6615 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
6616 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
6617 	    {
6618 		ga_clear(&ga);
6619 		break;
6620 	    }
6621 
6622 	    // copy the text up to where the match is
6623 	    i = (int)(regmatch.startp[0] - tail);
6624 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
6625 	    // add the substituted text
6626 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
6627 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
6628 	    ga.ga_len += i + sublen - 1;
6629 	    tail = regmatch.endp[0];
6630 	    if (*tail == NUL)
6631 		break;
6632 	    if (!do_all)
6633 		break;
6634 	}
6635 
6636 	if (ga.ga_data != NULL)
6637 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
6638 
6639 	vim_regfree(regmatch.regprog);
6640     }
6641 
6642     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
6643     ga_clear(&ga);
6644     if (p_cpo == empty_option)
6645 	p_cpo = save_cpo;
6646     else
6647 	// Darn, evaluating {sub} expression or {expr} changed the value.
6648 	free_string_option(save_cpo);
6649 
6650     return ret;
6651 }
6652