xref: /vim-8.2.3635/src/eval.c (revision 2b59df00)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * eval.c: Expression evaluation.
12  */
13 #define USING_FLOAT_STUFF
14 
15 #include "vim.h"
16 
17 #if defined(FEAT_EVAL) || defined(PROTO)
18 
19 #ifdef VMS
20 # include <float.h>
21 #endif
22 
23 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
24 
25 /*
26  * When recursively copying lists and dicts we need to remember which ones we
27  * have done to avoid endless recursiveness.  This unique ID is used for that.
28  * The last bit is used for previous_funccal, ignored when comparing.
29  */
30 static int current_copyID = 0;
31 
32 /*
33  * Info used by a ":for" loop.
34  */
35 typedef struct
36 {
37     int		fi_semicolon;	// TRUE if ending in '; var]'
38     int		fi_varcount;	// nr of variables in the list
39     int		fi_break_count;	// nr of line breaks encountered
40     listwatch_T	fi_lw;		// keep an eye on the item used.
41     list_T	*fi_list;	// list being used
42     int		fi_bi;		// index of blob
43     blob_T	*fi_blob;	// blob being used
44     char_u	*fi_string;	// copy of string being used
45     int		fi_byte_idx;	// byte index in fi_string
46 } forinfo_T;
47 
48 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
49 static int eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
50 static int eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
51 static int eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
52 static int eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
53 static int eval6(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int want_string);
54 static int eval7t(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int want_string);
55 static int eval7(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int want_string);
56 static int eval7_leader(typval_T *rettv, int numeric_only, char_u *start_leader, char_u **end_leaderp);
57 
58 static int free_unref_items(int copyID);
59 static char_u *make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
60 static char_u *eval_next_line(evalarg_T *evalarg);
61 
62 /*
63  * Return "n1" divided by "n2", taking care of dividing by zero.
64  * If "failed" is not NULL set it to TRUE when dividing by zero fails.
65  */
66 	varnumber_T
67 num_divide(varnumber_T n1, varnumber_T n2, int *failed)
68 {
69     varnumber_T	result;
70 
71     if (n2 == 0)
72     {
73 	if (in_vim9script())
74 	{
75 	    emsg(_(e_divide_by_zero));
76 	    if (failed != NULL)
77 		*failed = TRUE;
78 	}
79 	if (n1 == 0)
80 	    result = VARNUM_MIN; // similar to NaN
81 	else if (n1 < 0)
82 	    result = -VARNUM_MAX;
83 	else
84 	    result = VARNUM_MAX;
85     }
86     else
87 	result = n1 / n2;
88 
89     return result;
90 }
91 
92 /*
93  * Return "n1" modulus "n2", taking care of dividing by zero.
94  * If "failed" is not NULL set it to TRUE when dividing by zero fails.
95  */
96 	varnumber_T
97 num_modulus(varnumber_T n1, varnumber_T n2, int *failed)
98 {
99     if (n2 == 0 && in_vim9script())
100     {
101 	emsg(_(e_divide_by_zero));
102 	if (failed != NULL)
103 	    *failed = TRUE;
104     }
105     return (n2 == 0) ? 0 : (n1 % n2);
106 }
107 
108 /*
109  * Initialize the global and v: variables.
110  */
111     void
112 eval_init(void)
113 {
114     evalvars_init();
115     func_init();
116 
117 #ifdef EBCDIC
118     /*
119      * Sort the function table, to enable binary search.
120      */
121     sortFunctions();
122 #endif
123 }
124 
125 #if defined(EXITFREE) || defined(PROTO)
126     void
127 eval_clear(void)
128 {
129     evalvars_clear();
130     free_scriptnames();  // must come after evalvars_clear().
131     free_locales();
132 
133     // autoloaded script names
134     free_autoload_scriptnames();
135 
136     // unreferenced lists and dicts
137     (void)garbage_collect(FALSE);
138 
139     // functions not garbage collected
140     free_all_functions();
141 }
142 #endif
143 
144     void
145 fill_evalarg_from_eap(evalarg_T *evalarg, exarg_T *eap, int skip)
146 {
147     CLEAR_FIELD(*evalarg);
148     evalarg->eval_flags = skip ? 0 : EVAL_EVALUATE;
149     if (eap != NULL && getline_equal(eap->getline, eap->cookie, getsourceline))
150     {
151 	evalarg->eval_getline = eap->getline;
152 	evalarg->eval_cookie = eap->cookie;
153     }
154 }
155 
156 /*
157  * Top level evaluation function, returning a boolean.
158  * Sets "error" to TRUE if there was an error.
159  * Return TRUE or FALSE.
160  */
161     int
162 eval_to_bool(
163     char_u	*arg,
164     int		*error,
165     exarg_T	*eap,
166     int		skip)	    // only parse, don't execute
167 {
168     typval_T	tv;
169     varnumber_T	retval = FALSE;
170     evalarg_T	evalarg;
171 
172     fill_evalarg_from_eap(&evalarg, eap, skip);
173 
174     if (skip)
175 	++emsg_skip;
176     if (eval0(arg, &tv, eap, &evalarg) == FAIL)
177 	*error = TRUE;
178     else
179     {
180 	*error = FALSE;
181 	if (!skip)
182 	{
183 	    if (in_vim9script())
184 		retval = tv_get_bool_chk(&tv, error);
185 	    else
186 		retval = (tv_get_number_chk(&tv, error) != 0);
187 	    clear_tv(&tv);
188 	}
189     }
190     if (skip)
191 	--emsg_skip;
192     clear_evalarg(&evalarg, eap);
193 
194     return (int)retval;
195 }
196 
197 /*
198  * Call eval1() and give an error message if not done at a lower level.
199  */
200     static int
201 eval1_emsg(char_u **arg, typval_T *rettv, exarg_T *eap)
202 {
203     char_u	*start = *arg;
204     int		ret;
205     int		did_emsg_before = did_emsg;
206     int		called_emsg_before = called_emsg;
207     evalarg_T	evalarg;
208 
209     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
210 
211     ret = eval1(arg, rettv, &evalarg);
212     if (ret == FAIL)
213     {
214 	// Report the invalid expression unless the expression evaluation has
215 	// been cancelled due to an aborting error, an interrupt, or an
216 	// exception, or we already gave a more specific error.
217 	// Also check called_emsg for when using assert_fails().
218 	if (!aborting() && did_emsg == did_emsg_before
219 					  && called_emsg == called_emsg_before)
220 	    semsg(_(e_invalid_expression_str), start);
221     }
222     clear_evalarg(&evalarg, eap);
223     return ret;
224 }
225 
226 /*
227  * Return whether a typval is a valid expression to pass to eval_expr_typval()
228  * or eval_expr_to_bool().  An empty string returns FALSE;
229  */
230     int
231 eval_expr_valid_arg(typval_T *tv)
232 {
233     return tv->v_type != VAR_UNKNOWN
234 	    && (tv->v_type != VAR_STRING
235 		  || (tv->vval.v_string != NULL && *tv->vval.v_string != NUL));
236 }
237 
238 /*
239  * Evaluate an expression, which can be a function, partial or string.
240  * Pass arguments "argv[argc]".
241  * Return the result in "rettv" and OK or FAIL.
242  */
243     int
244 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
245 {
246     char_u	*s;
247     char_u	buf[NUMBUFLEN];
248     funcexe_T	funcexe;
249 
250     if (expr->v_type == VAR_FUNC)
251     {
252 	s = expr->vval.v_string;
253 	if (s == NULL || *s == NUL)
254 	    return FAIL;
255 	CLEAR_FIELD(funcexe);
256 	funcexe.evaluate = TRUE;
257 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
258 	    return FAIL;
259     }
260     else if (expr->v_type == VAR_PARTIAL)
261     {
262 	partial_T   *partial = expr->vval.v_partial;
263 
264 	if (partial == NULL)
265 	    return FAIL;
266 
267 	if (partial->pt_func != NULL
268 			  && partial->pt_func->uf_def_status != UF_NOT_COMPILED)
269 	{
270 	    if (call_def_function(partial->pt_func, argc, argv,
271 						       partial, rettv) == FAIL)
272 		return FAIL;
273 	}
274 	else
275 	{
276 	    s = partial_name(partial);
277 	    if (s == NULL || *s == NUL)
278 		return FAIL;
279 	    CLEAR_FIELD(funcexe);
280 	    funcexe.evaluate = TRUE;
281 	    funcexe.partial = partial;
282 	    if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
283 		return FAIL;
284 	}
285     }
286     else if (expr->v_type == VAR_INSTR)
287     {
288 	return exe_typval_instr(expr, rettv);
289     }
290     else
291     {
292 	s = tv_get_string_buf_chk(expr, buf);
293 	if (s == NULL)
294 	    return FAIL;
295 	s = skipwhite(s);
296 	if (eval1_emsg(&s, rettv, NULL) == FAIL)
297 	    return FAIL;
298 	if (*skipwhite(s) != NUL)  // check for trailing chars after expr
299 	{
300 	    clear_tv(rettv);
301 	    semsg(_(e_invalid_expression_str), s);
302 	    return FAIL;
303 	}
304     }
305     return OK;
306 }
307 
308 /*
309  * Like eval_to_bool() but using a typval_T instead of a string.
310  * Works for string, funcref and partial.
311  */
312     int
313 eval_expr_to_bool(typval_T *expr, int *error)
314 {
315     typval_T	rettv;
316     int		res;
317 
318     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
319     {
320 	*error = TRUE;
321 	return FALSE;
322     }
323     res = (tv_get_bool_chk(&rettv, error) != 0);
324     clear_tv(&rettv);
325     return res;
326 }
327 
328 /*
329  * Top level evaluation function, returning a string.  If "skip" is TRUE,
330  * only parsing to "nextcmd" is done, without reporting errors.  Return
331  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
332  */
333     char_u *
334 eval_to_string_skip(
335     char_u	*arg,
336     exarg_T	*eap,
337     int		skip)	    // only parse, don't execute
338 {
339     typval_T	tv;
340     char_u	*retval;
341     evalarg_T	evalarg;
342 
343     fill_evalarg_from_eap(&evalarg, eap, skip);
344     if (skip)
345 	++emsg_skip;
346     if (eval0(arg, &tv, eap, &evalarg) == FAIL || skip)
347 	retval = NULL;
348     else
349     {
350 	retval = vim_strsave(tv_get_string(&tv));
351 	clear_tv(&tv);
352     }
353     if (skip)
354 	--emsg_skip;
355     clear_evalarg(&evalarg, eap);
356 
357     return retval;
358 }
359 
360 /*
361  * Skip over an expression at "*pp".
362  * Return FAIL for an error, OK otherwise.
363  */
364     int
365 skip_expr(char_u **pp, evalarg_T *evalarg)
366 {
367     typval_T	rettv;
368 
369     *pp = skipwhite(*pp);
370     return eval1(pp, &rettv, evalarg);
371 }
372 
373 /*
374  * Skip over an expression at "*arg".
375  * If in Vim9 script and line breaks are encountered, the lines are
376  * concatenated.  "evalarg->eval_tofree" will be set accordingly.
377  * "arg" is advanced to just after the expression.
378  * "start" is set to the start of the expression, "end" to just after the end.
379  * Also when the expression is copied to allocated memory.
380  * Return FAIL for an error, OK otherwise.
381  */
382     int
383 skip_expr_concatenate(
384 	char_u	    **arg,
385 	char_u	    **start,
386 	char_u	    **end,
387 	evalarg_T   *evalarg)
388 {
389     typval_T	rettv;
390     int		res;
391     int		vim9script = in_vim9script();
392     garray_T    *gap = evalarg == NULL ? NULL : &evalarg->eval_ga;
393     garray_T    *freegap = evalarg == NULL ? NULL : &evalarg->eval_freega;
394     int		save_flags = evalarg == NULL ? 0 : evalarg->eval_flags;
395     int		evaluate = evalarg == NULL
396 			       ? FALSE : (evalarg->eval_flags & EVAL_EVALUATE);
397 
398     if (vim9script && evaluate
399 	       && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
400     {
401 	ga_init2(gap, sizeof(char_u *), 10);
402 	// leave room for "start"
403 	if (ga_grow(gap, 1) == OK)
404 	    ++gap->ga_len;
405 	ga_init2(freegap, sizeof(char_u *), 10);
406     }
407     *start = *arg;
408 
409     // Don't evaluate the expression.
410     if (evalarg != NULL)
411 	evalarg->eval_flags &= ~EVAL_EVALUATE;
412     *arg = skipwhite(*arg);
413     res = eval1(arg, &rettv, evalarg);
414     *end = *arg;
415     if (evalarg != NULL)
416 	evalarg->eval_flags = save_flags;
417 
418     if (vim9script && evaluate
419 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
420     {
421 	if (evalarg->eval_ga.ga_len == 1)
422 	{
423 	    // just the one line, no need to concatenate
424 	    ga_clear(gap);
425 	    gap->ga_itemsize = 0;
426 	}
427 	else
428 	{
429 	    char_u	    *p;
430 	    size_t	    endoff = STRLEN(*arg);
431 
432 	    // Line breaks encountered, concatenate all the lines.
433 	    *((char_u **)gap->ga_data) = *start;
434 	    p = ga_concat_strings(gap, " ");
435 
436 	    // free the lines only when using getsourceline()
437 	    if (evalarg->eval_cookie != NULL)
438 	    {
439 		// Do not free the first line, the caller can still use it.
440 		*((char_u **)gap->ga_data) = NULL;
441 		// Do not free the last line, "arg" points into it, free it
442 		// later.
443 		vim_free(evalarg->eval_tofree);
444 		evalarg->eval_tofree =
445 				    ((char_u **)gap->ga_data)[gap->ga_len - 1];
446 		((char_u **)gap->ga_data)[gap->ga_len - 1] = NULL;
447 		ga_clear_strings(gap);
448 	    }
449 	    else
450 	    {
451 		ga_clear(gap);
452 
453 		// free lines that were explicitly marked for freeing
454 		ga_clear_strings(freegap);
455 	    }
456 
457 	    gap->ga_itemsize = 0;
458 	    if (p == NULL)
459 		return FAIL;
460 	    *start = p;
461 	    vim_free(evalarg->eval_tofree_lambda);
462 	    evalarg->eval_tofree_lambda = p;
463 	    // Compute "end" relative to the end.
464 	    *end = *start + STRLEN(*start) - endoff;
465 	}
466     }
467 
468     return res;
469 }
470 
471 /*
472  * Convert "tv" to a string.
473  * When "convert" is TRUE convert a List into a sequence of lines and convert
474  * a Float to a String.
475  * Returns an allocated string (NULL when out of memory).
476  */
477     char_u *
478 typval2string(typval_T *tv, int convert)
479 {
480     garray_T	ga;
481     char_u	*retval;
482 #ifdef FEAT_FLOAT
483     char_u	numbuf[NUMBUFLEN];
484 #endif
485 
486     if (convert && tv->v_type == VAR_LIST)
487     {
488 	ga_init2(&ga, (int)sizeof(char), 80);
489 	if (tv->vval.v_list != NULL)
490 	{
491 	    list_join(&ga, tv->vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
492 	    if (tv->vval.v_list->lv_len > 0)
493 		ga_append(&ga, NL);
494 	}
495 	ga_append(&ga, NUL);
496 	retval = (char_u *)ga.ga_data;
497     }
498 #ifdef FEAT_FLOAT
499     else if (convert && tv->v_type == VAR_FLOAT)
500     {
501 	vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
502 	retval = vim_strsave(numbuf);
503     }
504 #endif
505     else
506 	retval = vim_strsave(tv_get_string(tv));
507     return retval;
508 }
509 
510 /*
511  * Top level evaluation function, returning a string.  Does not handle line
512  * breaks.
513  * When "convert" is TRUE convert a List into a sequence of lines and convert
514  * a Float to a String.
515  * Return pointer to allocated memory, or NULL for failure.
516  */
517     char_u *
518 eval_to_string_eap(
519     char_u	*arg,
520     int		convert,
521     exarg_T	*eap)
522 {
523     typval_T	tv;
524     char_u	*retval;
525     evalarg_T	evalarg;
526 
527     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
528     if (eval0(arg, &tv, NULL, &evalarg) == FAIL)
529 	retval = NULL;
530     else
531     {
532 	retval = typval2string(&tv, convert);
533 	clear_tv(&tv);
534     }
535     clear_evalarg(&evalarg, NULL);
536 
537     return retval;
538 }
539 
540     char_u *
541 eval_to_string(
542     char_u	*arg,
543     int		convert)
544 {
545     return eval_to_string_eap(arg, convert, NULL);
546 }
547 
548 /*
549  * Call eval_to_string() without using current local variables and using
550  * textwinlock.  When "use_sandbox" is TRUE use the sandbox.
551  * Use legacy Vim script syntax.
552  */
553     char_u *
554 eval_to_string_safe(
555     char_u	*arg,
556     int		use_sandbox)
557 {
558     char_u	*retval;
559     funccal_entry_T funccal_entry;
560     int		save_sc_version = current_sctx.sc_version;
561 
562     current_sctx.sc_version = 1;
563     save_funccal(&funccal_entry);
564     if (use_sandbox)
565 	++sandbox;
566     ++textwinlock;
567     retval = eval_to_string(arg, FALSE);
568     if (use_sandbox)
569 	--sandbox;
570     --textwinlock;
571     restore_funccal();
572     current_sctx.sc_version = save_sc_version;
573     return retval;
574 }
575 
576 /*
577  * Top level evaluation function, returning a number.
578  * Evaluates "expr" silently.
579  * Returns -1 for an error.
580  */
581     varnumber_T
582 eval_to_number(char_u *expr)
583 {
584     typval_T	rettv;
585     varnumber_T	retval;
586     char_u	*p = skipwhite(expr);
587 
588     ++emsg_off;
589 
590     if (eval1(&p, &rettv, &EVALARG_EVALUATE) == FAIL)
591 	retval = -1;
592     else
593     {
594 	retval = tv_get_number_chk(&rettv, NULL);
595 	clear_tv(&rettv);
596     }
597     --emsg_off;
598 
599     return retval;
600 }
601 
602 /*
603  * Top level evaluation function.
604  * Returns an allocated typval_T with the result.
605  * Returns NULL when there is an error.
606  */
607     typval_T *
608 eval_expr(char_u *arg, exarg_T *eap)
609 {
610     typval_T	*tv;
611     evalarg_T	evalarg;
612 
613     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
614 
615     tv = ALLOC_ONE(typval_T);
616     if (tv != NULL && eval0(arg, tv, eap, &evalarg) == FAIL)
617 	VIM_CLEAR(tv);
618 
619     clear_evalarg(&evalarg, eap);
620     return tv;
621 }
622 
623 /*
624  * Call some Vim script function and return the result in "*rettv".
625  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
626  * should have type VAR_UNKNOWN.
627  * Returns OK or FAIL.
628  */
629     int
630 call_vim_function(
631     char_u      *func,
632     int		argc,
633     typval_T	*argv,
634     typval_T	*rettv)
635 {
636     int		ret;
637     funcexe_T	funcexe;
638 
639     rettv->v_type = VAR_UNKNOWN;		// clear_tv() uses this
640     CLEAR_FIELD(funcexe);
641     funcexe.firstline = curwin->w_cursor.lnum;
642     funcexe.lastline = curwin->w_cursor.lnum;
643     funcexe.evaluate = TRUE;
644     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
645     if (ret == FAIL)
646 	clear_tv(rettv);
647 
648     return ret;
649 }
650 
651 /*
652  * Call Vim script function "func" and return the result as a number.
653  * Returns -1 when calling the function fails.
654  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
655  * have type VAR_UNKNOWN.
656  */
657     varnumber_T
658 call_func_retnr(
659     char_u      *func,
660     int		argc,
661     typval_T	*argv)
662 {
663     typval_T	rettv;
664     varnumber_T	retval;
665 
666     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
667 	return -1;
668 
669     retval = tv_get_number_chk(&rettv, NULL);
670     clear_tv(&rettv);
671     return retval;
672 }
673 
674 /*
675  * Call Vim script function like call_func_retnr() and drop the result.
676  * Returns FAIL when calling the function fails.
677  */
678     int
679 call_func_noret(
680     char_u      *func,
681     int		argc,
682     typval_T	*argv)
683 {
684     typval_T	rettv;
685 
686     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
687 	return FAIL;
688     clear_tv(&rettv);
689     return OK;
690 }
691 
692 /*
693  * Call Vim script function "func" and return the result as a string.
694  * Uses "argv" and "argc" as call_func_retnr().
695  * Returns NULL when calling the function fails.
696  */
697     void *
698 call_func_retstr(
699     char_u      *func,
700     int		argc,
701     typval_T	*argv)
702 {
703     typval_T	rettv;
704     char_u	*retval;
705 
706     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
707 	return NULL;
708 
709     retval = vim_strsave(tv_get_string(&rettv));
710     clear_tv(&rettv);
711     return retval;
712 }
713 
714 /*
715  * Call Vim script function "func" and return the result as a List.
716  * Uses "argv" and "argc" as call_func_retnr().
717  * Returns NULL when there is something wrong.
718  */
719     void *
720 call_func_retlist(
721     char_u      *func,
722     int		argc,
723     typval_T	*argv)
724 {
725     typval_T	rettv;
726 
727     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
728 	return NULL;
729 
730     if (rettv.v_type != VAR_LIST)
731     {
732 	clear_tv(&rettv);
733 	return NULL;
734     }
735 
736     return rettv.vval.v_list;
737 }
738 
739 #ifdef FEAT_FOLDING
740 /*
741  * Evaluate "arg", which is 'foldexpr'.
742  * Note: caller must set "curwin" to match "arg".
743  * Returns the foldlevel, and any character preceding it in "*cp".  Doesn't
744  * give error messages.
745  */
746     int
747 eval_foldexpr(char_u *arg, int *cp)
748 {
749     typval_T	tv;
750     varnumber_T	retval;
751     char_u	*s;
752     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
753 								   OPT_LOCAL);
754 
755     ++emsg_off;
756     if (use_sandbox)
757 	++sandbox;
758     ++textwinlock;
759     *cp = NUL;
760     if (eval0(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
761 	retval = 0;
762     else
763     {
764 	// If the result is a number, just return the number.
765 	if (tv.v_type == VAR_NUMBER)
766 	    retval = tv.vval.v_number;
767 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
768 	    retval = 0;
769 	else
770 	{
771 	    // If the result is a string, check if there is a non-digit before
772 	    // the number.
773 	    s = tv.vval.v_string;
774 	    if (!VIM_ISDIGIT(*s) && *s != '-')
775 		*cp = *s++;
776 	    retval = atol((char *)s);
777 	}
778 	clear_tv(&tv);
779     }
780     --emsg_off;
781     if (use_sandbox)
782 	--sandbox;
783     --textwinlock;
784     clear_evalarg(&EVALARG_EVALUATE, NULL);
785 
786     return (int)retval;
787 }
788 #endif
789 
790 /*
791  * Get an lval: variable, Dict item or List item that can be assigned a value
792  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
793  * "name.key", "name.key[expr]" etc.
794  * Indexing only works if "name" is an existing List or Dictionary.
795  * "name" points to the start of the name.
796  * If "rettv" is not NULL it points to the value to be assigned.
797  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
798  * wrong; must end in space or cmd separator.
799  *
800  * flags:
801  *  GLV_QUIET:       do not give error messages
802  *  GLV_READ_ONLY:   will not change the variable
803  *  GLV_NO_AUTOLOAD: do not use script autoloading
804  *
805  * Returns a pointer to just after the name, including indexes.
806  * When an evaluation error occurs "lp->ll_name" is NULL;
807  * Returns NULL for a parsing error.  Still need to free items in "lp"!
808  */
809     char_u *
810 get_lval(
811     char_u	*name,
812     typval_T	*rettv,
813     lval_T	*lp,
814     int		unlet,
815     int		skip,
816     int		flags,	    // GLV_ values
817     int		fne_flags)  // flags for find_name_end()
818 {
819     char_u	*p;
820     char_u	*expr_start, *expr_end;
821     int		cc;
822     dictitem_T	*v;
823     typval_T	var1;
824     typval_T	var2;
825     int		empty1 = FALSE;
826     listitem_T	*ni;
827     char_u	*key = NULL;
828     int		len;
829     hashtab_T	*ht = NULL;
830     int		quiet = flags & GLV_QUIET;
831     int		writing;
832 
833     // Clear everything in "lp".
834     CLEAR_POINTER(lp);
835 
836     if (skip || (flags & GLV_COMPILING))
837     {
838 	// When skipping or compiling just find the end of the name.
839 	lp->ll_name = name;
840 	lp->ll_name_end = find_name_end(name, NULL, NULL,
841 						      FNE_INCL_BR | fne_flags);
842 	return lp->ll_name_end;
843     }
844 
845     // Find the end of the name.
846     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
847     lp->ll_name_end = p;
848     if (expr_start != NULL)
849     {
850 	// Don't expand the name when we already know there is an error.
851 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
852 						    && *p != '[' && *p != '.')
853 	{
854 	    semsg(_(e_trailing_arg), p);
855 	    return NULL;
856 	}
857 
858 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
859 	if (lp->ll_exp_name == NULL)
860 	{
861 	    // Report an invalid expression in braces, unless the
862 	    // expression evaluation has been cancelled due to an
863 	    // aborting error, an interrupt, or an exception.
864 	    if (!aborting() && !quiet)
865 	    {
866 		emsg_severe = TRUE;
867 		semsg(_(e_invarg2), name);
868 		return NULL;
869 	    }
870 	}
871 	lp->ll_name = lp->ll_exp_name;
872     }
873     else
874     {
875 	lp->ll_name = name;
876 
877 	if (in_vim9script())
878 	{
879 	    // "a: type" is declaring variable "a" with a type, not "a:".
880 	    if (p == name + 2 && p[-1] == ':')
881 	    {
882 		--p;
883 		lp->ll_name_end = p;
884 	    }
885 	    if (*p == ':')
886 	    {
887 		scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);
888 		char_u	 *tp = skipwhite(p + 1);
889 
890 		// parse the type after the name
891 		lp->ll_type = parse_type(&tp, &si->sn_type_list, !quiet);
892 		if (lp->ll_type == NULL && !quiet)
893 		    return NULL;
894 		lp->ll_name_end = tp;
895 	    }
896 	}
897     }
898 
899     // Without [idx] or .key we are done.
900     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
901 	return p;
902 
903     cc = *p;
904     *p = NUL;
905     // When we would write to the variable pass &ht and prevent autoload.
906     writing = !(flags & GLV_READ_ONLY);
907     v = find_var(lp->ll_name, writing ? &ht : NULL,
908 					 (flags & GLV_NO_AUTOLOAD) || writing);
909     if (v == NULL && !quiet)
910 	semsg(_(e_undefined_variable_str), lp->ll_name);
911     *p = cc;
912     if (v == NULL)
913 	return NULL;
914 
915     if (in_vim9script() && (flags & GLV_NO_DECL) == 0)
916     {
917 	if (!quiet)
918 	    semsg(_(e_variable_already_declared), lp->ll_name);
919 	return NULL;
920     }
921 
922     /*
923      * Loop until no more [idx] or .key is following.
924      */
925     lp->ll_tv = &v->di_tv;
926     var1.v_type = VAR_UNKNOWN;
927     var2.v_type = VAR_UNKNOWN;
928     while (*p == '[' || (*p == '.' && p[1] != '=' && p[1] != '.'))
929     {
930 	if (*p == '.' && lp->ll_tv->v_type != VAR_DICT)
931 	{
932 	    if (!quiet)
933 		semsg(_(e_dot_can_only_be_used_on_dictionary_str), name);
934 	    return NULL;
935 	}
936 	if (lp->ll_tv->v_type != VAR_LIST
937 		&& lp->ll_tv->v_type != VAR_DICT
938 		&& lp->ll_tv->v_type != VAR_BLOB)
939 	{
940 	    if (!quiet)
941 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
942 	    return NULL;
943 	}
944 
945 	// a NULL list/blob works like an empty list/blob, allocate one now.
946 	if (lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list == NULL)
947 	    rettv_list_alloc(lp->ll_tv);
948 	else if (lp->ll_tv->v_type == VAR_BLOB
949 					     && lp->ll_tv->vval.v_blob == NULL)
950 	    rettv_blob_alloc(lp->ll_tv);
951 
952 	if (lp->ll_range)
953 	{
954 	    if (!quiet)
955 		emsg(_("E708: [:] must come last"));
956 	    return NULL;
957 	}
958 
959 	if (in_vim9script() && lp->ll_valtype == NULL
960 		&& lp->ll_tv == &v->di_tv
961 		&& ht != NULL && ht == get_script_local_ht())
962 	{
963 	    svar_T  *sv = find_typval_in_script(lp->ll_tv);
964 
965 	    // Vim9 script local variable: get the type
966 	    if (sv != NULL)
967 		lp->ll_valtype = sv->sv_type;
968 	}
969 
970 	len = -1;
971 	if (*p == '.')
972 	{
973 	    key = p + 1;
974 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
975 		;
976 	    if (len == 0)
977 	    {
978 		if (!quiet)
979 		    emsg(_(e_emptykey));
980 		return NULL;
981 	    }
982 	    p = key + len;
983 	}
984 	else
985 	{
986 	    // Get the index [expr] or the first index [expr: ].
987 	    p = skipwhite(p + 1);
988 	    if (*p == ':')
989 		empty1 = TRUE;
990 	    else
991 	    {
992 		empty1 = FALSE;
993 		if (eval1(&p, &var1, &EVALARG_EVALUATE) == FAIL)  // recursive!
994 		    return NULL;
995 		if (tv_get_string_chk(&var1) == NULL)
996 		{
997 		    // not a number or string
998 		    clear_tv(&var1);
999 		    return NULL;
1000 		}
1001 		p = skipwhite(p);
1002 	    }
1003 
1004 	    // Optionally get the second index [ :expr].
1005 	    if (*p == ':')
1006 	    {
1007 		if (lp->ll_tv->v_type == VAR_DICT)
1008 		{
1009 		    if (!quiet)
1010 			emsg(_(e_cannot_slice_dictionary));
1011 		    clear_tv(&var1);
1012 		    return NULL;
1013 		}
1014 		if (rettv != NULL
1015 			&& !(rettv->v_type == VAR_LIST
1016 						 && rettv->vval.v_list != NULL)
1017 			&& !(rettv->v_type == VAR_BLOB
1018 						&& rettv->vval.v_blob != NULL))
1019 		{
1020 		    if (!quiet)
1021 			emsg(_("E709: [:] requires a List or Blob value"));
1022 		    clear_tv(&var1);
1023 		    return NULL;
1024 		}
1025 		p = skipwhite(p + 1);
1026 		if (*p == ']')
1027 		    lp->ll_empty2 = TRUE;
1028 		else
1029 		{
1030 		    lp->ll_empty2 = FALSE;
1031 		    // recursive!
1032 		    if (eval1(&p, &var2, &EVALARG_EVALUATE) == FAIL)
1033 		    {
1034 			clear_tv(&var1);
1035 			return NULL;
1036 		    }
1037 		    if (tv_get_string_chk(&var2) == NULL)
1038 		    {
1039 			// not a number or string
1040 			clear_tv(&var1);
1041 			clear_tv(&var2);
1042 			return NULL;
1043 		    }
1044 		}
1045 		lp->ll_range = TRUE;
1046 	    }
1047 	    else
1048 		lp->ll_range = FALSE;
1049 
1050 	    if (*p != ']')
1051 	    {
1052 		if (!quiet)
1053 		    emsg(_(e_missbrac));
1054 		clear_tv(&var1);
1055 		clear_tv(&var2);
1056 		return NULL;
1057 	    }
1058 
1059 	    // Skip to past ']'.
1060 	    ++p;
1061 	}
1062 
1063 	if (lp->ll_tv->v_type == VAR_DICT)
1064 	{
1065 	    if (len == -1)
1066 	    {
1067 		// "[key]": get key from "var1"
1068 		key = tv_get_string_chk(&var1);	// is number or string
1069 		if (key == NULL)
1070 		{
1071 		    clear_tv(&var1);
1072 		    return NULL;
1073 		}
1074 	    }
1075 	    lp->ll_list = NULL;
1076 
1077 	    // a NULL dict is equivalent with an empty dict
1078 	    if (lp->ll_tv->vval.v_dict == NULL)
1079 	    {
1080 		lp->ll_tv->vval.v_dict = dict_alloc();
1081 		if (lp->ll_tv->vval.v_dict == NULL)
1082 		{
1083 		    clear_tv(&var1);
1084 		    return NULL;
1085 		}
1086 		++lp->ll_tv->vval.v_dict->dv_refcount;
1087 	    }
1088 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
1089 
1090 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
1091 
1092 	    // When assigning to a scope dictionary check that a function and
1093 	    // variable name is valid (only variable name unless it is l: or
1094 	    // g: dictionary). Disallow overwriting a builtin function.
1095 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
1096 	    {
1097 		int prevval;
1098 		int wrong;
1099 
1100 		if (len != -1)
1101 		{
1102 		    prevval = key[len];
1103 		    key[len] = NUL;
1104 		}
1105 		else
1106 		    prevval = 0; // avoid compiler warning
1107 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
1108 			       && rettv->v_type == VAR_FUNC
1109 			       && var_wrong_func_name(key, lp->ll_di == NULL))
1110 			|| !valid_varname(key, TRUE);
1111 		if (len != -1)
1112 		    key[len] = prevval;
1113 		if (wrong)
1114 		{
1115 		    clear_tv(&var1);
1116 		    return NULL;
1117 		}
1118 	    }
1119 
1120 	    if (lp->ll_valtype != NULL)
1121 		// use the type of the member
1122 		lp->ll_valtype = lp->ll_valtype->tt_member;
1123 
1124 	    if (lp->ll_di == NULL)
1125 	    {
1126 		// Can't add "v:" or "a:" variable.
1127 		if (lp->ll_dict == get_vimvar_dict()
1128 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
1129 		{
1130 		    semsg(_(e_illvar), name);
1131 		    clear_tv(&var1);
1132 		    return NULL;
1133 		}
1134 
1135 		// Key does not exist in dict: may need to add it.
1136 		if (*p == '[' || *p == '.' || unlet)
1137 		{
1138 		    if (!quiet)
1139 			semsg(_(e_dictkey), key);
1140 		    clear_tv(&var1);
1141 		    return NULL;
1142 		}
1143 		if (len == -1)
1144 		    lp->ll_newkey = vim_strsave(key);
1145 		else
1146 		    lp->ll_newkey = vim_strnsave(key, len);
1147 		clear_tv(&var1);
1148 		if (lp->ll_newkey == NULL)
1149 		    p = NULL;
1150 		break;
1151 	    }
1152 	    // existing variable, need to check if it can be changed
1153 	    else if ((flags & GLV_READ_ONLY) == 0
1154 			&& (var_check_ro(lp->ll_di->di_flags, name, FALSE)
1155 			  || var_check_lock(lp->ll_di->di_flags, name, FALSE)))
1156 	    {
1157 		clear_tv(&var1);
1158 		return NULL;
1159 	    }
1160 
1161 	    clear_tv(&var1);
1162 	    lp->ll_tv = &lp->ll_di->di_tv;
1163 	}
1164 	else if (lp->ll_tv->v_type == VAR_BLOB)
1165 	{
1166 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
1167 
1168 	    /*
1169 	     * Get the number and item for the only or first index of the List.
1170 	     */
1171 	    if (empty1)
1172 		lp->ll_n1 = 0;
1173 	    else
1174 		// is number or string
1175 		lp->ll_n1 = (long)tv_get_number(&var1);
1176 	    clear_tv(&var1);
1177 
1178 	    if (check_blob_index(bloblen, lp->ll_n1, quiet) == FAIL)
1179 	    {
1180 		clear_tv(&var2);
1181 		return NULL;
1182 	    }
1183 	    if (lp->ll_range && !lp->ll_empty2)
1184 	    {
1185 		lp->ll_n2 = (long)tv_get_number(&var2);
1186 		clear_tv(&var2);
1187 		if (check_blob_range(bloblen, lp->ll_n1, lp->ll_n2, quiet)
1188 								       == FAIL)
1189 		    return NULL;
1190 	    }
1191 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
1192 	    lp->ll_tv = NULL;
1193 	    break;
1194 	}
1195 	else
1196 	{
1197 	    /*
1198 	     * Get the number and item for the only or first index of the List.
1199 	     */
1200 	    if (empty1)
1201 		lp->ll_n1 = 0;
1202 	    else
1203 		// is number or string
1204 		lp->ll_n1 = (long)tv_get_number(&var1);
1205 	    clear_tv(&var1);
1206 
1207 	    lp->ll_dict = NULL;
1208 	    lp->ll_list = lp->ll_tv->vval.v_list;
1209 	    lp->ll_li = list_find_index(lp->ll_list, &lp->ll_n1);
1210 	    if (lp->ll_li == NULL)
1211 	    {
1212 		// Vim9: Allow for adding an item at the end.
1213 		if (in_vim9script() && lp->ll_n1 == lp->ll_list->lv_len
1214 						  && lp->ll_list->lv_lock == 0)
1215 		{
1216 		    list_append_number(lp->ll_list, 0);
1217 		    lp->ll_li = list_find_index(lp->ll_list, &lp->ll_n1);
1218 		}
1219 		if (lp->ll_li == NULL)
1220 		{
1221 		    clear_tv(&var2);
1222 		    if (!quiet)
1223 			semsg(_(e_listidx), lp->ll_n1);
1224 		    return NULL;
1225 		}
1226 	    }
1227 
1228 	    if (lp->ll_valtype != NULL)
1229 		// use the type of the member
1230 		lp->ll_valtype = lp->ll_valtype->tt_member;
1231 
1232 	    /*
1233 	     * May need to find the item or absolute index for the second
1234 	     * index of a range.
1235 	     * When no index given: "lp->ll_empty2" is TRUE.
1236 	     * Otherwise "lp->ll_n2" is set to the second index.
1237 	     */
1238 	    if (lp->ll_range && !lp->ll_empty2)
1239 	    {
1240 		lp->ll_n2 = (long)tv_get_number(&var2);
1241 						    // is number or string
1242 		clear_tv(&var2);
1243 		if (lp->ll_n2 < 0)
1244 		{
1245 		    ni = list_find(lp->ll_list, lp->ll_n2);
1246 		    if (ni == NULL)
1247 		    {
1248 			if (!quiet)
1249 			    semsg(_(e_listidx), lp->ll_n2);
1250 			return NULL;
1251 		    }
1252 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
1253 		}
1254 
1255 		// Check that lp->ll_n2 isn't before lp->ll_n1.
1256 		if (lp->ll_n1 < 0)
1257 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
1258 		if (lp->ll_n2 < lp->ll_n1)
1259 		{
1260 		    if (!quiet)
1261 			semsg(_(e_listidx), lp->ll_n2);
1262 		    return NULL;
1263 		}
1264 	    }
1265 
1266 	    lp->ll_tv = &lp->ll_li->li_tv;
1267 	}
1268     }
1269 
1270     clear_tv(&var1);
1271     lp->ll_name_end = p;
1272     return p;
1273 }
1274 
1275 /*
1276  * Clear lval "lp" that was filled by get_lval().
1277  */
1278     void
1279 clear_lval(lval_T *lp)
1280 {
1281     vim_free(lp->ll_exp_name);
1282     vim_free(lp->ll_newkey);
1283 }
1284 
1285 /*
1286  * Set a variable that was parsed by get_lval() to "rettv".
1287  * "endp" points to just after the parsed name.
1288  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
1289  * "%" for "%=", "." for ".=" or "=" for "=".
1290  */
1291     void
1292 set_var_lval(
1293     lval_T	*lp,
1294     char_u	*endp,
1295     typval_T	*rettv,
1296     int		copy,
1297     int		flags,	    // ASSIGN_CONST, ASSIGN_NO_DECL
1298     char_u	*op,
1299     int		var_idx)    // index for "let [a, b] = list"
1300 {
1301     int		cc;
1302     listitem_T	*ri;
1303     dictitem_T	*di;
1304 
1305     if (lp->ll_tv == NULL)
1306     {
1307 	cc = *endp;
1308 	*endp = NUL;
1309 	if (in_vim9script() && check_reserved_name(lp->ll_name) == FAIL)
1310 	    return;
1311 
1312 	if (lp->ll_blob != NULL)
1313 	{
1314 	    int	    error = FALSE, val;
1315 
1316 	    if (op != NULL && *op != '=')
1317 	    {
1318 		semsg(_(e_letwrong), op);
1319 		return;
1320 	    }
1321 	    if (value_check_lock(lp->ll_blob->bv_lock, lp->ll_name, FALSE))
1322 		return;
1323 
1324 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
1325 	    {
1326 		if (lp->ll_empty2)
1327 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
1328 
1329 		if (blob_set_range(lp->ll_blob, lp->ll_n1, lp->ll_n2,
1330 								rettv) == FAIL)
1331 		    return;
1332 	    }
1333 	    else
1334 	    {
1335 		val = (int)tv_get_number_chk(rettv, &error);
1336 		if (!error)
1337 		    blob_set_append(lp->ll_blob, lp->ll_n1, val);
1338 	    }
1339 	}
1340 	else if (op != NULL && *op != '=')
1341 	{
1342 	    typval_T tv;
1343 
1344 	    if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
1345 					     && (flags & ASSIGN_FOR_LOOP) == 0)
1346 	    {
1347 		emsg(_(e_cannot_mod));
1348 		*endp = cc;
1349 		return;
1350 	    }
1351 
1352 	    // handle +=, -=, *=, /=, %= and .=
1353 	    di = NULL;
1354 	    if (eval_variable(lp->ll_name, (int)STRLEN(lp->ll_name),
1355 					     &tv, &di, EVAL_VAR_VERBOSE) == OK)
1356 	    {
1357 		if ((di == NULL
1358 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
1359 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
1360 			&& tv_op(&tv, rettv, op) == OK)
1361 		    set_var_const(lp->ll_name, NULL, &tv, FALSE,
1362 							    ASSIGN_NO_DECL, 0);
1363 		clear_tv(&tv);
1364 	    }
1365 	}
1366 	else
1367 	{
1368 	    if (lp->ll_type != NULL && check_typval_arg_type(lp->ll_type, rettv,
1369 							      NULL, 0) == FAIL)
1370 		return;
1371 	    set_var_const(lp->ll_name, lp->ll_type, rettv, copy,
1372 							       flags, var_idx);
1373 	}
1374 	*endp = cc;
1375     }
1376     else if (value_check_lock(lp->ll_newkey == NULL
1377 		? lp->ll_tv->v_lock
1378 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
1379 	;
1380     else if (lp->ll_range)
1381     {
1382 	listitem_T *ll_li = lp->ll_li;
1383 	int	    ll_n1 = lp->ll_n1;
1384 
1385 	if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
1386 					     && (flags & ASSIGN_FOR_LOOP) == 0)
1387 	{
1388 	    emsg(_("E996: Cannot lock a range"));
1389 	    return;
1390 	}
1391 
1392 	/*
1393 	 * Check whether any of the list items is locked
1394 	 */
1395 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
1396 	{
1397 	    if (value_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
1398 		return;
1399 	    ri = ri->li_next;
1400 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
1401 		break;
1402 	    ll_li = ll_li->li_next;
1403 	    ++ll_n1;
1404 	}
1405 
1406 	/*
1407 	 * Assign the List values to the list items.
1408 	 */
1409 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
1410 	{
1411 	    if (op != NULL && *op != '=')
1412 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
1413 	    else
1414 	    {
1415 		clear_tv(&lp->ll_li->li_tv);
1416 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
1417 	    }
1418 	    ri = ri->li_next;
1419 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
1420 		break;
1421 	    if (lp->ll_li->li_next == NULL)
1422 	    {
1423 		// Need to add an empty item.
1424 		if (list_append_number(lp->ll_list, 0) == FAIL)
1425 		{
1426 		    ri = NULL;
1427 		    break;
1428 		}
1429 	    }
1430 	    lp->ll_li = lp->ll_li->li_next;
1431 	    ++lp->ll_n1;
1432 	}
1433 	if (ri != NULL)
1434 	    emsg(_(e_list_value_has_more_items_than_targets));
1435 	else if (lp->ll_empty2
1436 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
1437 		: lp->ll_n1 != lp->ll_n2)
1438 	    emsg(_(e_list_value_does_not_have_enough_items));
1439     }
1440     else
1441     {
1442 	/*
1443 	 * Assign to a List or Dictionary item.
1444 	 */
1445 	if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
1446 					     && (flags & ASSIGN_FOR_LOOP) == 0)
1447 	{
1448 	    emsg(_("E996: Cannot lock a list or dict"));
1449 	    return;
1450 	}
1451 
1452 	if (lp->ll_valtype != NULL
1453 		    && check_typval_arg_type(lp->ll_valtype, rettv,
1454 							      NULL, 0) == FAIL)
1455 	    return;
1456 
1457 	if (lp->ll_newkey != NULL)
1458 	{
1459 	    if (op != NULL && *op != '=')
1460 	    {
1461 		semsg(_(e_dictkey), lp->ll_newkey);
1462 		return;
1463 	    }
1464 	    if (dict_wrong_func_name(lp->ll_tv->vval.v_dict, rettv,
1465 								lp->ll_newkey))
1466 		return;
1467 
1468 	    // Need to add an item to the Dictionary.
1469 	    di = dictitem_alloc(lp->ll_newkey);
1470 	    if (di == NULL)
1471 		return;
1472 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
1473 	    {
1474 		vim_free(di);
1475 		return;
1476 	    }
1477 	    lp->ll_tv = &di->di_tv;
1478 	}
1479 	else if (op != NULL && *op != '=')
1480 	{
1481 	    tv_op(lp->ll_tv, rettv, op);
1482 	    return;
1483 	}
1484 	else
1485 	    clear_tv(lp->ll_tv);
1486 
1487 	/*
1488 	 * Assign the value to the variable or list item.
1489 	 */
1490 	if (copy)
1491 	    copy_tv(rettv, lp->ll_tv);
1492 	else
1493 	{
1494 	    *lp->ll_tv = *rettv;
1495 	    lp->ll_tv->v_lock = 0;
1496 	    init_tv(rettv);
1497 	}
1498     }
1499 }
1500 
1501 /*
1502  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
1503  * and "tv1 .= tv2"
1504  * Returns OK or FAIL.
1505  */
1506     static int
1507 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
1508 {
1509     varnumber_T	n;
1510     char_u	numbuf[NUMBUFLEN];
1511     char_u	*s;
1512     int		failed = FALSE;
1513 
1514     // Can't do anything with a Funcref, Dict, v:true on the right.
1515     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
1516 		      && tv2->v_type != VAR_BOOL && tv2->v_type != VAR_SPECIAL)
1517     {
1518 	switch (tv1->v_type)
1519 	{
1520 	    case VAR_UNKNOWN:
1521 	    case VAR_ANY:
1522 	    case VAR_VOID:
1523 	    case VAR_DICT:
1524 	    case VAR_FUNC:
1525 	    case VAR_PARTIAL:
1526 	    case VAR_BOOL:
1527 	    case VAR_SPECIAL:
1528 	    case VAR_JOB:
1529 	    case VAR_CHANNEL:
1530 	    case VAR_INSTR:
1531 		break;
1532 
1533 	    case VAR_BLOB:
1534 		if (*op != '+' || tv2->v_type != VAR_BLOB)
1535 		    break;
1536 		// BLOB += BLOB
1537 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
1538 		{
1539 		    blob_T  *b1 = tv1->vval.v_blob;
1540 		    blob_T  *b2 = tv2->vval.v_blob;
1541 		    int	i, len = blob_len(b2);
1542 		    for (i = 0; i < len; i++)
1543 			ga_append(&b1->bv_ga, blob_get(b2, i));
1544 		}
1545 		return OK;
1546 
1547 	    case VAR_LIST:
1548 		if (*op != '+' || tv2->v_type != VAR_LIST)
1549 		    break;
1550 		// List += List
1551 		if (tv2->vval.v_list != NULL)
1552 		{
1553 		    if (tv1->vval.v_list == NULL)
1554 		    {
1555 			tv1->vval.v_list = tv2->vval.v_list;
1556 			++tv1->vval.v_list->lv_refcount;
1557 		    }
1558 		    else
1559 			list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
1560 		}
1561 		return OK;
1562 
1563 	    case VAR_NUMBER:
1564 	    case VAR_STRING:
1565 		if (tv2->v_type == VAR_LIST)
1566 		    break;
1567 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
1568 		{
1569 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
1570 		    n = tv_get_number(tv1);
1571 #ifdef FEAT_FLOAT
1572 		    if (tv2->v_type == VAR_FLOAT)
1573 		    {
1574 			float_T f = n;
1575 
1576 			if (*op == '%')
1577 			    break;
1578 			switch (*op)
1579 			{
1580 			    case '+': f += tv2->vval.v_float; break;
1581 			    case '-': f -= tv2->vval.v_float; break;
1582 			    case '*': f *= tv2->vval.v_float; break;
1583 			    case '/': f /= tv2->vval.v_float; break;
1584 			}
1585 			clear_tv(tv1);
1586 			tv1->v_type = VAR_FLOAT;
1587 			tv1->vval.v_float = f;
1588 		    }
1589 		    else
1590 #endif
1591 		    {
1592 			switch (*op)
1593 			{
1594 			    case '+': n += tv_get_number(tv2); break;
1595 			    case '-': n -= tv_get_number(tv2); break;
1596 			    case '*': n *= tv_get_number(tv2); break;
1597 			    case '/': n = num_divide(n, tv_get_number(tv2),
1598 							       &failed); break;
1599 			    case '%': n = num_modulus(n, tv_get_number(tv2),
1600 							       &failed); break;
1601 			}
1602 			clear_tv(tv1);
1603 			tv1->v_type = VAR_NUMBER;
1604 			tv1->vval.v_number = n;
1605 		    }
1606 		}
1607 		else
1608 		{
1609 		    if (tv2->v_type == VAR_FLOAT)
1610 			break;
1611 
1612 		    // str .= str
1613 		    s = tv_get_string(tv1);
1614 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
1615 		    clear_tv(tv1);
1616 		    tv1->v_type = VAR_STRING;
1617 		    tv1->vval.v_string = s;
1618 		}
1619 		return failed ? FAIL : OK;
1620 
1621 	    case VAR_FLOAT:
1622 #ifdef FEAT_FLOAT
1623 		{
1624 		    float_T f;
1625 
1626 		    if (*op == '%' || *op == '.'
1627 				   || (tv2->v_type != VAR_FLOAT
1628 				    && tv2->v_type != VAR_NUMBER
1629 				    && tv2->v_type != VAR_STRING))
1630 			break;
1631 		    if (tv2->v_type == VAR_FLOAT)
1632 			f = tv2->vval.v_float;
1633 		    else
1634 			f = tv_get_number(tv2);
1635 		    switch (*op)
1636 		    {
1637 			case '+': tv1->vval.v_float += f; break;
1638 			case '-': tv1->vval.v_float -= f; break;
1639 			case '*': tv1->vval.v_float *= f; break;
1640 			case '/': tv1->vval.v_float /= f; break;
1641 		    }
1642 		}
1643 #endif
1644 		return OK;
1645 	}
1646     }
1647 
1648     semsg(_(e_letwrong), op);
1649     return FAIL;
1650 }
1651 
1652 /*
1653  * Evaluate the expression used in a ":for var in expr" command.
1654  * "arg" points to "var".
1655  * Set "*errp" to TRUE for an error, FALSE otherwise;
1656  * Return a pointer that holds the info.  Null when there is an error.
1657  */
1658     void *
1659 eval_for_line(
1660     char_u	*arg,
1661     int		*errp,
1662     exarg_T	*eap,
1663     evalarg_T	*evalarg)
1664 {
1665     forinfo_T	*fi;
1666     char_u	*var_list_end;
1667     char_u	*expr;
1668     typval_T	tv;
1669     list_T	*l;
1670     int		skip = !(evalarg->eval_flags & EVAL_EVALUATE);
1671 
1672     *errp = TRUE;	// default: there is an error
1673 
1674     fi = ALLOC_CLEAR_ONE(forinfo_T);
1675     if (fi == NULL)
1676 	return NULL;
1677 
1678     var_list_end = skip_var_list(arg, TRUE, &fi->fi_varcount,
1679 						     &fi->fi_semicolon, FALSE);
1680     if (var_list_end == NULL)
1681 	return fi;
1682 
1683     expr = skipwhite_and_linebreak(var_list_end, evalarg);
1684     if (expr[0] != 'i' || expr[1] != 'n'
1685 				  || !(expr[2] == NUL || VIM_ISWHITE(expr[2])))
1686     {
1687 	if (in_vim9script() && *expr == ':' && expr != var_list_end)
1688 	    semsg(_(e_no_white_space_allowed_before_colon_str), expr);
1689 	else
1690 	    emsg(_(e_missing_in));
1691 	return fi;
1692     }
1693 
1694     if (skip)
1695 	++emsg_skip;
1696     expr = skipwhite_and_linebreak(expr + 2, evalarg);
1697     if (eval0(expr, &tv, eap, evalarg) == OK)
1698     {
1699 	*errp = FALSE;
1700 	if (!skip)
1701 	{
1702 	    if (tv.v_type == VAR_LIST)
1703 	    {
1704 		l = tv.vval.v_list;
1705 		if (l == NULL)
1706 		{
1707 		    // a null list is like an empty list: do nothing
1708 		    clear_tv(&tv);
1709 		}
1710 		else
1711 		{
1712 		    // Need a real list here.
1713 		    CHECK_LIST_MATERIALIZE(l);
1714 
1715 		    // No need to increment the refcount, it's already set for
1716 		    // the list being used in "tv".
1717 		    fi->fi_list = l;
1718 		    list_add_watch(l, &fi->fi_lw);
1719 		    fi->fi_lw.lw_item = l->lv_first;
1720 		}
1721 	    }
1722 	    else if (tv.v_type == VAR_BLOB)
1723 	    {
1724 		fi->fi_bi = 0;
1725 		if (tv.vval.v_blob != NULL)
1726 		{
1727 		    typval_T btv;
1728 
1729 		    // Make a copy, so that the iteration still works when the
1730 		    // blob is changed.
1731 		    blob_copy(tv.vval.v_blob, &btv);
1732 		    fi->fi_blob = btv.vval.v_blob;
1733 		}
1734 		clear_tv(&tv);
1735 	    }
1736 	    else if (tv.v_type == VAR_STRING)
1737 	    {
1738 		fi->fi_byte_idx = 0;
1739 		fi->fi_string = tv.vval.v_string;
1740 		tv.vval.v_string = NULL;
1741 		if (fi->fi_string == NULL)
1742 		    fi->fi_string = vim_strsave((char_u *)"");
1743 	    }
1744 	    else
1745 	    {
1746 		emsg(_(e_listreq));
1747 		clear_tv(&tv);
1748 	    }
1749 	}
1750     }
1751     if (skip)
1752 	--emsg_skip;
1753     fi->fi_break_count = evalarg->eval_break_count;
1754 
1755     return fi;
1756 }
1757 
1758 /*
1759  * Used when looping over a :for line, skip the "in expr" part.
1760  */
1761     void
1762 skip_for_lines(void *fi_void, evalarg_T *evalarg)
1763 {
1764     forinfo_T	*fi = (forinfo_T *)fi_void;
1765     int		i;
1766 
1767     for (i = 0; i < fi->fi_break_count; ++i)
1768 	eval_next_line(evalarg);
1769 }
1770 
1771 /*
1772  * Use the first item in a ":for" list.  Advance to the next.
1773  * Assign the values to the variable (list).  "arg" points to the first one.
1774  * Return TRUE when a valid item was found, FALSE when at end of list or
1775  * something wrong.
1776  */
1777     int
1778 next_for_item(void *fi_void, char_u *arg)
1779 {
1780     forinfo_T	*fi = (forinfo_T *)fi_void;
1781     int		result;
1782     int		flag = ASSIGN_FOR_LOOP | (in_vim9script()
1783 			 ? (ASSIGN_FINAL
1784 			     // first round: error if variable exists
1785 			     | (fi->fi_bi == 0 ? 0 : ASSIGN_DECL)
1786 			     | ASSIGN_NO_MEMBER_TYPE)
1787 			 : 0);
1788     listitem_T	*item;
1789     int		skip_assign = in_vim9script() && arg[0] == '_'
1790 						      && !eval_isnamec(arg[1]);
1791 
1792     if (fi->fi_blob != NULL)
1793     {
1794 	typval_T	tv;
1795 
1796 	if (fi->fi_bi >= blob_len(fi->fi_blob))
1797 	    return FALSE;
1798 	tv.v_type = VAR_NUMBER;
1799 	tv.v_lock = VAR_FIXED;
1800 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
1801 	++fi->fi_bi;
1802 	if (skip_assign)
1803 	    return TRUE;
1804 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1805 					    fi->fi_varcount, flag, NULL) == OK;
1806     }
1807 
1808     if (fi->fi_string != NULL)
1809     {
1810 	typval_T	tv;
1811 	int		len;
1812 
1813 	len = mb_ptr2len(fi->fi_string + fi->fi_byte_idx);
1814 	if (len == 0)
1815 	    return FALSE;
1816 	tv.v_type = VAR_STRING;
1817 	tv.v_lock = VAR_FIXED;
1818 	tv.vval.v_string = vim_strnsave(fi->fi_string + fi->fi_byte_idx, len);
1819 	fi->fi_byte_idx += len;
1820 	++fi->fi_bi;
1821 	if (skip_assign)
1822 	    result = TRUE;
1823 	else
1824 	    result = ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1825 					    fi->fi_varcount, flag, NULL) == OK;
1826 	vim_free(tv.vval.v_string);
1827 	return result;
1828     }
1829 
1830     item = fi->fi_lw.lw_item;
1831     if (item == NULL)
1832 	result = FALSE;
1833     else
1834     {
1835 	fi->fi_lw.lw_item = item->li_next;
1836 	++fi->fi_bi;
1837 	if (skip_assign)
1838 	    result = TRUE;
1839 	else
1840 	    result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
1841 					   fi->fi_varcount, flag, NULL) == OK);
1842     }
1843     return result;
1844 }
1845 
1846 /*
1847  * Free the structure used to store info used by ":for".
1848  */
1849     void
1850 free_for_info(void *fi_void)
1851 {
1852     forinfo_T    *fi = (forinfo_T *)fi_void;
1853 
1854     if (fi == NULL)
1855 	return;
1856     if (fi->fi_list != NULL)
1857     {
1858 	list_rem_watch(fi->fi_list, &fi->fi_lw);
1859 	list_unref(fi->fi_list);
1860     }
1861     else if (fi->fi_blob != NULL)
1862 	blob_unref(fi->fi_blob);
1863     else
1864 	vim_free(fi->fi_string);
1865     vim_free(fi);
1866 }
1867 
1868     void
1869 set_context_for_expression(
1870     expand_T	*xp,
1871     char_u	*arg,
1872     cmdidx_T	cmdidx)
1873 {
1874     int		has_expr = cmdidx != CMD_let && cmdidx != CMD_var;
1875     int		c;
1876     char_u	*p;
1877 
1878     if (cmdidx == CMD_let || cmdidx == CMD_var
1879 				 || cmdidx == CMD_const || cmdidx == CMD_final)
1880     {
1881 	xp->xp_context = EXPAND_USER_VARS;
1882 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
1883 	{
1884 	    // ":let var1 var2 ...": find last space.
1885 	    for (p = arg + STRLEN(arg); p >= arg; )
1886 	    {
1887 		xp->xp_pattern = p;
1888 		MB_PTR_BACK(arg, p);
1889 		if (VIM_ISWHITE(*p))
1890 		    break;
1891 	    }
1892 	    return;
1893 	}
1894     }
1895     else
1896 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
1897 							  : EXPAND_EXPRESSION;
1898     while ((xp->xp_pattern = vim_strpbrk(arg,
1899 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
1900     {
1901 	c = *xp->xp_pattern;
1902 	if (c == '&')
1903 	{
1904 	    c = xp->xp_pattern[1];
1905 	    if (c == '&')
1906 	    {
1907 		++xp->xp_pattern;
1908 		xp->xp_context = has_expr ? EXPAND_EXPRESSION : EXPAND_NOTHING;
1909 	    }
1910 	    else if (c != ' ')
1911 	    {
1912 		xp->xp_context = EXPAND_SETTINGS;
1913 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
1914 		    xp->xp_pattern += 2;
1915 
1916 	    }
1917 	}
1918 	else if (c == '$')
1919 	{
1920 	    // environment variable
1921 	    xp->xp_context = EXPAND_ENV_VARS;
1922 	}
1923 	else if (c == '=')
1924 	{
1925 	    has_expr = TRUE;
1926 	    xp->xp_context = EXPAND_EXPRESSION;
1927 	}
1928 	else if (c == '#'
1929 		&& xp->xp_context == EXPAND_EXPRESSION)
1930 	{
1931 	    // Autoload function/variable contains '#'.
1932 	    break;
1933 	}
1934 	else if ((c == '<' || c == '#')
1935 		&& xp->xp_context == EXPAND_FUNCTIONS
1936 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
1937 	{
1938 	    // Function name can start with "<SNR>" and contain '#'.
1939 	    break;
1940 	}
1941 	else if (has_expr)
1942 	{
1943 	    if (c == '"')	    // string
1944 	    {
1945 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
1946 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
1947 			++xp->xp_pattern;
1948 		xp->xp_context = EXPAND_NOTHING;
1949 	    }
1950 	    else if (c == '\'')	    // literal string
1951 	    {
1952 		// Trick: '' is like stopping and starting a literal string.
1953 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
1954 		    /* skip */ ;
1955 		xp->xp_context = EXPAND_NOTHING;
1956 	    }
1957 	    else if (c == '|')
1958 	    {
1959 		if (xp->xp_pattern[1] == '|')
1960 		{
1961 		    ++xp->xp_pattern;
1962 		    xp->xp_context = EXPAND_EXPRESSION;
1963 		}
1964 		else
1965 		    xp->xp_context = EXPAND_COMMANDS;
1966 	    }
1967 	    else
1968 		xp->xp_context = EXPAND_EXPRESSION;
1969 	}
1970 	else
1971 	    // Doesn't look like something valid, expand as an expression
1972 	    // anyway.
1973 	    xp->xp_context = EXPAND_EXPRESSION;
1974 	arg = xp->xp_pattern;
1975 	if (*arg != NUL)
1976 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
1977 		/* skip */ ;
1978     }
1979 
1980     // ":exe one two" completes "two"
1981     if ((cmdidx == CMD_execute
1982 		|| cmdidx == CMD_echo
1983 		|| cmdidx == CMD_echon
1984 		|| cmdidx == CMD_echomsg)
1985 	    && xp->xp_context == EXPAND_EXPRESSION)
1986     {
1987 	for (;;)
1988 	{
1989 	    char_u *n = skiptowhite(arg);
1990 
1991 	    if (n == arg || IS_WHITE_OR_NUL(*skipwhite(n)))
1992 		break;
1993 	    arg = skipwhite(n);
1994 	}
1995     }
1996 
1997     xp->xp_pattern = arg;
1998 }
1999 
2000 /*
2001  * Return TRUE if "pat" matches "text".
2002  * Does not use 'cpo' and always uses 'magic'.
2003  */
2004     int
2005 pattern_match(char_u *pat, char_u *text, int ic)
2006 {
2007     int		matches = FALSE;
2008     char_u	*save_cpo;
2009     regmatch_T	regmatch;
2010 
2011     // avoid 'l' flag in 'cpoptions'
2012     save_cpo = p_cpo;
2013     p_cpo = empty_option;
2014     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
2015     if (regmatch.regprog != NULL)
2016     {
2017 	regmatch.rm_ic = ic;
2018 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
2019 	vim_regfree(regmatch.regprog);
2020     }
2021     p_cpo = save_cpo;
2022     return matches;
2023 }
2024 
2025 /*
2026  * Handle a name followed by "(".  Both for just "name(arg)" and for
2027  * "expr->name(arg)".
2028  * Returns OK or FAIL.
2029  */
2030     static int
2031 eval_func(
2032 	char_u	    **arg,	// points to "(", will be advanced
2033 	evalarg_T   *evalarg,
2034 	char_u	    *name,
2035 	int	    name_len,
2036 	typval_T    *rettv,
2037 	int	    flags,
2038 	typval_T    *basetv)	// "expr" for "expr->name(arg)"
2039 {
2040     int		evaluate = flags & EVAL_EVALUATE;
2041     char_u	*s = name;
2042     int		len = name_len;
2043     partial_T	*partial;
2044     int		ret = OK;
2045     type_T	*type = NULL;
2046 
2047     if (!evaluate)
2048 	check_vars(s, len);
2049 
2050     // If "s" is the name of a variable of type VAR_FUNC
2051     // use its contents.
2052     s = deref_func_name(s, &len, &partial,
2053 				    in_vim9script() ? &type : NULL, !evaluate);
2054 
2055     // Need to make a copy, in case evaluating the arguments makes
2056     // the name invalid.
2057     s = vim_strsave(s);
2058     if (s == NULL || (flags & EVAL_CONSTANT))
2059 	ret = FAIL;
2060     else
2061     {
2062 	funcexe_T funcexe;
2063 
2064 	// Invoke the function.
2065 	CLEAR_FIELD(funcexe);
2066 	funcexe.firstline = curwin->w_cursor.lnum;
2067 	funcexe.lastline = curwin->w_cursor.lnum;
2068 	funcexe.evaluate = evaluate;
2069 	funcexe.partial = partial;
2070 	funcexe.basetv = basetv;
2071 	funcexe.check_type = type;
2072 	ret = get_func_tv(s, len, rettv, arg, evalarg, &funcexe);
2073     }
2074     vim_free(s);
2075 
2076     // If evaluate is FALSE rettv->v_type was not set in
2077     // get_func_tv, but it's needed in handle_subscript() to parse
2078     // what follows. So set it here.
2079     if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
2080     {
2081 	rettv->vval.v_string = NULL;
2082 	rettv->v_type = VAR_FUNC;
2083     }
2084 
2085     // Stop the expression evaluation when immediately
2086     // aborting on error, or when an interrupt occurred or
2087     // an exception was thrown but not caught.
2088     if (evaluate && aborting())
2089     {
2090 	if (ret == OK)
2091 	    clear_tv(rettv);
2092 	ret = FAIL;
2093     }
2094     return ret;
2095 }
2096 
2097 /*
2098  * Get the next line source line without advancing.  But do skip over comment
2099  * lines.
2100  * Only called for Vim9 script.
2101  */
2102     static char_u *
2103 getline_peek_skip_comments(evalarg_T *evalarg)
2104 {
2105     for (;;)
2106     {
2107 	char_u *next = getline_peek(evalarg->eval_getline,
2108 							 evalarg->eval_cookie);
2109 	char_u *p;
2110 
2111 	if (next == NULL)
2112 	    break;
2113 	p = skipwhite(next);
2114 	if (*p != NUL && !vim9_comment_start(p))
2115 	    return next;
2116 	(void)eval_next_line(evalarg);
2117     }
2118     return NULL;
2119 }
2120 
2121 /*
2122  * If inside Vim9 script, "arg" points to the end of a line (ignoring a #
2123  * comment) and there is a next line, return the next line (skipping blanks)
2124  * and set "getnext".
2125  * Otherwise return the next non-white at or after "arg" and set "getnext" to
2126  * FALSE.
2127  * "arg" must point somewhere inside a line, not at the start.
2128  */
2129     static char_u *
2130 eval_next_non_blank(char_u *arg, evalarg_T *evalarg, int *getnext)
2131 {
2132     char_u *p = skipwhite(arg);
2133 
2134     *getnext = FALSE;
2135     if (in_vim9script()
2136 	    && evalarg != NULL
2137 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL)
2138 	    && (*p == NUL || (vim9_comment_start(p) && VIM_ISWHITE(p[-1]))))
2139     {
2140 	char_u *next;
2141 
2142 	if (evalarg->eval_cookie != NULL)
2143 	    next = getline_peek_skip_comments(evalarg);
2144 	else
2145 	    next = peek_next_line_from_context(evalarg->eval_cctx);
2146 
2147 	if (next != NULL)
2148 	{
2149 	    *getnext = TRUE;
2150 	    return skipwhite(next);
2151 	}
2152     }
2153     return p;
2154 }
2155 
2156 /*
2157  * To be called after eval_next_non_blank() sets "getnext" to TRUE.
2158  * Only called for Vim9 script.
2159  */
2160     static char_u *
2161 eval_next_line(evalarg_T *evalarg)
2162 {
2163     garray_T	*gap = &evalarg->eval_ga;
2164     char_u	*line;
2165 
2166     if (evalarg->eval_cookie != NULL)
2167 	line = evalarg->eval_getline(0, evalarg->eval_cookie, 0,
2168 							   GETLINE_CONCAT_ALL);
2169     else
2170 	line = next_line_from_context(evalarg->eval_cctx, TRUE);
2171     ++evalarg->eval_break_count;
2172     if (gap->ga_itemsize > 0 && ga_grow(gap, 1) == OK)
2173     {
2174 	char_u *p = skipwhite(line);
2175 
2176 	// Going to concatenate the lines after parsing.  For an empty or
2177 	// comment line use an empty string.
2178 	if (*p == NUL || vim9_comment_start(p))
2179 	{
2180 	    vim_free(line);
2181 	    line = vim_strsave((char_u *)"");
2182 	}
2183 
2184 	((char_u **)gap->ga_data)[gap->ga_len] = line;
2185 	++gap->ga_len;
2186     }
2187     else if (evalarg->eval_cookie != NULL)
2188     {
2189 	vim_free(evalarg->eval_tofree);
2190 	evalarg->eval_tofree = line;
2191     }
2192 
2193     // Advanced to the next line, "arg" no longer points into the previous
2194     // line.
2195     VIM_CLEAR(evalarg->eval_tofree_cmdline);
2196 
2197     return skipwhite(line);
2198 }
2199 
2200 /*
2201  * Call eval_next_non_blank() and get the next line if needed.
2202  */
2203     char_u *
2204 skipwhite_and_linebreak(char_u *arg, evalarg_T *evalarg)
2205 {
2206     int	    getnext;
2207     char_u  *p = skipwhite(arg);
2208 
2209     if (evalarg == NULL)
2210 	return skipwhite(arg);
2211     eval_next_non_blank(p, evalarg, &getnext);
2212     if (getnext)
2213 	return eval_next_line(evalarg);
2214     return p;
2215 }
2216 
2217 /*
2218  * After using "evalarg" filled from "eap": free the memory.
2219  */
2220     void
2221 clear_evalarg(evalarg_T *evalarg, exarg_T *eap)
2222 {
2223     if (evalarg != NULL)
2224     {
2225 	if (evalarg->eval_tofree != NULL)
2226 	{
2227 	    if (eap != NULL)
2228 	    {
2229 		// We may need to keep the original command line, e.g. for
2230 		// ":let" it has the variable names.  But we may also need the
2231 		// new one, "nextcmd" points into it.  Keep both.
2232 		vim_free(eap->cmdline_tofree);
2233 		eap->cmdline_tofree = *eap->cmdlinep;
2234 		*eap->cmdlinep = evalarg->eval_tofree;
2235 	    }
2236 	    else
2237 		vim_free(evalarg->eval_tofree);
2238 	    evalarg->eval_tofree = NULL;
2239 	}
2240 
2241 	VIM_CLEAR(evalarg->eval_tofree_cmdline);
2242 	VIM_CLEAR(evalarg->eval_tofree_lambda);
2243     }
2244 }
2245 
2246 /*
2247  * The "evaluate" argument: When FALSE, the argument is only parsed but not
2248  * executed.  The function may return OK, but the rettv will be of type
2249  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
2250  */
2251 
2252 /*
2253  * Handle zero level expression.
2254  * This calls eval1() and handles error message and nextcmd.
2255  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
2256  * Note: "rettv.v_lock" is not set.
2257  * "evalarg" can be NULL, EVALARG_EVALUATE or a pointer.
2258  * Return OK or FAIL.
2259  */
2260     int
2261 eval0(
2262     char_u	*arg,
2263     typval_T	*rettv,
2264     exarg_T	*eap,
2265     evalarg_T	*evalarg)
2266 {
2267     int		ret;
2268     char_u	*p;
2269     int		did_emsg_before = did_emsg;
2270     int		called_emsg_before = called_emsg;
2271     int		flags = evalarg == NULL ? 0 : evalarg->eval_flags;
2272     int		end_error = FALSE;
2273 
2274     p = skipwhite(arg);
2275     ret = eval1(&p, rettv, evalarg);
2276     p = skipwhite(p);
2277 
2278     if (ret != FAIL)
2279 	end_error = !ends_excmd2(arg, p);
2280     if (ret == FAIL || end_error)
2281     {
2282 	if (ret != FAIL)
2283 	    clear_tv(rettv);
2284 	/*
2285 	 * Report the invalid expression unless the expression evaluation has
2286 	 * been cancelled due to an aborting error, an interrupt, or an
2287 	 * exception, or we already gave a more specific error.
2288 	 * Also check called_emsg for when using assert_fails().
2289 	 */
2290 	if (!aborting()
2291 		&& did_emsg == did_emsg_before
2292 		&& called_emsg == called_emsg_before
2293 		&& (flags & EVAL_CONSTANT) == 0
2294 		&& (!in_vim9script() || !vim9_bad_comment(p)))
2295 	{
2296 	    if (end_error)
2297 		semsg(_(e_trailing_arg), p);
2298 	    else
2299 		semsg(_(e_invalid_expression_str), arg);
2300 	}
2301 
2302 	// Some of the expression may not have been consumed.  Do not check for
2303 	// a next command to avoid more errors, unless "|" is following, which
2304 	// could only be a command separator.
2305 	if (eap != NULL && skipwhite(p)[0] == '|' && skipwhite(p)[1] != '|')
2306 	    eap->nextcmd = check_nextcmd(p);
2307 	return FAIL;
2308     }
2309 
2310     if (eap != NULL)
2311 	eap->nextcmd = check_nextcmd(p);
2312 
2313     return ret;
2314 }
2315 
2316 /*
2317  * Handle top level expression:
2318  *	expr2 ? expr1 : expr1
2319  *	expr2 ?? expr1
2320  *
2321  * "arg" must point to the first non-white of the expression.
2322  * "arg" is advanced to just after the recognized expression.
2323  *
2324  * Note: "rettv.v_lock" is not set.
2325  *
2326  * Return OK or FAIL.
2327  */
2328     int
2329 eval1(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2330 {
2331     char_u  *p;
2332     int	    getnext;
2333 
2334     CLEAR_POINTER(rettv);
2335 
2336     /*
2337      * Get the first variable.
2338      */
2339     if (eval2(arg, rettv, evalarg) == FAIL)
2340 	return FAIL;
2341 
2342     p = eval_next_non_blank(*arg, evalarg, &getnext);
2343     if (*p == '?')
2344     {
2345 	int		op_falsy = p[1] == '?';
2346 	int		result;
2347 	typval_T	var2;
2348 	evalarg_T	*evalarg_used = evalarg;
2349 	evalarg_T	local_evalarg;
2350 	int		orig_flags;
2351 	int		evaluate;
2352 	int		vim9script = in_vim9script();
2353 
2354 	if (evalarg == NULL)
2355 	{
2356 	    CLEAR_FIELD(local_evalarg);
2357 	    evalarg_used = &local_evalarg;
2358 	}
2359 	orig_flags = evalarg_used->eval_flags;
2360 	evaluate = evalarg_used->eval_flags & EVAL_EVALUATE;
2361 
2362 	if (getnext)
2363 	    *arg = eval_next_line(evalarg_used);
2364 	else
2365 	{
2366 	    if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2367 	    {
2368 		error_white_both(p, op_falsy ? 2 : 1);
2369 		clear_tv(rettv);
2370 		return FAIL;
2371 	    }
2372 	    *arg = p;
2373 	}
2374 
2375 	result = FALSE;
2376 	if (evaluate)
2377 	{
2378 	    int		error = FALSE;
2379 
2380 	    if (op_falsy)
2381 		result = tv2bool(rettv);
2382 	    else if (vim9script)
2383 		result = tv_get_bool_chk(rettv, &error);
2384 	    else if (tv_get_number_chk(rettv, &error) != 0)
2385 		result = TRUE;
2386 	    if (error || !op_falsy || !result)
2387 		clear_tv(rettv);
2388 	    if (error)
2389 		return FAIL;
2390 	}
2391 
2392 	/*
2393 	 * Get the second variable.  Recursive!
2394 	 */
2395 	if (op_falsy)
2396 	    ++*arg;
2397 	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[1]))
2398 	{
2399 	    error_white_both(*arg - (op_falsy ? 1 : 0), op_falsy ? 2 : 1);
2400 	    clear_tv(rettv);
2401 	    return FAIL;
2402 	}
2403 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2404 	evalarg_used->eval_flags = (op_falsy ? !result : result)
2405 				    ? orig_flags : orig_flags & ~EVAL_EVALUATE;
2406 	if (eval1(arg, &var2, evalarg_used) == FAIL)
2407 	{
2408 	    evalarg_used->eval_flags = orig_flags;
2409 	    return FAIL;
2410 	}
2411 	if (!op_falsy || !result)
2412 	    *rettv = var2;
2413 
2414 	if (!op_falsy)
2415 	{
2416 	    /*
2417 	     * Check for the ":".
2418 	     */
2419 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2420 	    if (*p != ':')
2421 	    {
2422 		emsg(_(e_missing_colon));
2423 		if (evaluate && result)
2424 		    clear_tv(rettv);
2425 		evalarg_used->eval_flags = orig_flags;
2426 		return FAIL;
2427 	    }
2428 	    if (getnext)
2429 		*arg = eval_next_line(evalarg_used);
2430 	    else
2431 	    {
2432 		if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2433 		{
2434 		    error_white_both(p, 1);
2435 		    clear_tv(rettv);
2436 		    evalarg_used->eval_flags = orig_flags;
2437 		    return FAIL;
2438 		}
2439 		*arg = p;
2440 	    }
2441 
2442 	    /*
2443 	     * Get the third variable.  Recursive!
2444 	     */
2445 	    if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[1]))
2446 	    {
2447 		error_white_both(*arg, 1);
2448 		clear_tv(rettv);
2449 		evalarg_used->eval_flags = orig_flags;
2450 		return FAIL;
2451 	    }
2452 	    *arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2453 	    evalarg_used->eval_flags = !result ? orig_flags
2454 						 : orig_flags & ~EVAL_EVALUATE;
2455 	    if (eval1(arg, &var2, evalarg_used) == FAIL)
2456 	    {
2457 		if (evaluate && result)
2458 		    clear_tv(rettv);
2459 		evalarg_used->eval_flags = orig_flags;
2460 		return FAIL;
2461 	    }
2462 	    if (evaluate && !result)
2463 		*rettv = var2;
2464 	}
2465 
2466 	if (evalarg == NULL)
2467 	    clear_evalarg(&local_evalarg, NULL);
2468 	else
2469 	    evalarg->eval_flags = orig_flags;
2470     }
2471 
2472     return OK;
2473 }
2474 
2475 /*
2476  * Handle first level expression:
2477  *	expr2 || expr2 || expr2	    logical OR
2478  *
2479  * "arg" must point to the first non-white of the expression.
2480  * "arg" is advanced to just after the recognized expression.
2481  *
2482  * Return OK or FAIL.
2483  */
2484     static int
2485 eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2486 {
2487     char_u	*p;
2488     int		getnext;
2489 
2490     /*
2491      * Get the first variable.
2492      */
2493     if (eval3(arg, rettv, evalarg) == FAIL)
2494 	return FAIL;
2495 
2496     /*
2497      * Handle the  "||" operator.
2498      */
2499     p = eval_next_non_blank(*arg, evalarg, &getnext);
2500     if (p[0] == '|' && p[1] == '|')
2501     {
2502 	evalarg_T   *evalarg_used = evalarg;
2503 	evalarg_T   local_evalarg;
2504 	int	    evaluate;
2505 	int	    orig_flags;
2506 	long	    result = FALSE;
2507 	typval_T    var2;
2508 	int	    error = FALSE;
2509 	int	    vim9script = in_vim9script();
2510 
2511 	if (evalarg == NULL)
2512 	{
2513 	    CLEAR_FIELD(local_evalarg);
2514 	    evalarg_used = &local_evalarg;
2515 	}
2516 	orig_flags = evalarg_used->eval_flags;
2517 	evaluate = orig_flags & EVAL_EVALUATE;
2518 	if (evaluate)
2519 	{
2520 	    if (vim9script)
2521 		result = tv_get_bool_chk(rettv, &error);
2522 	    else if (tv_get_number_chk(rettv, &error) != 0)
2523 		result = TRUE;
2524 	    clear_tv(rettv);
2525 	    if (error)
2526 		return FAIL;
2527 	}
2528 
2529 	/*
2530 	 * Repeat until there is no following "||".
2531 	 */
2532 	while (p[0] == '|' && p[1] == '|')
2533 	{
2534 	    if (getnext)
2535 		*arg = eval_next_line(evalarg_used);
2536 	    else
2537 	    {
2538 		if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2539 		{
2540 		    error_white_both(p, 2);
2541 		    clear_tv(rettv);
2542 		    return FAIL;
2543 		}
2544 		*arg = p;
2545 	    }
2546 
2547 	    /*
2548 	     * Get the second variable.
2549 	     */
2550 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2551 	    {
2552 		error_white_both(*arg, 2);
2553 		clear_tv(rettv);
2554 		return FAIL;
2555 	    }
2556 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2557 	    evalarg_used->eval_flags = !result ? orig_flags
2558 						 : orig_flags & ~EVAL_EVALUATE;
2559 	    if (eval3(arg, &var2, evalarg_used) == FAIL)
2560 		return FAIL;
2561 
2562 	    /*
2563 	     * Compute the result.
2564 	     */
2565 	    if (evaluate && !result)
2566 	    {
2567 		if (vim9script)
2568 		    result = tv_get_bool_chk(&var2, &error);
2569 		else if (tv_get_number_chk(&var2, &error) != 0)
2570 		    result = TRUE;
2571 		clear_tv(&var2);
2572 		if (error)
2573 		    return FAIL;
2574 	    }
2575 	    if (evaluate)
2576 	    {
2577 		if (vim9script)
2578 		{
2579 		    rettv->v_type = VAR_BOOL;
2580 		    rettv->vval.v_number = result ? VVAL_TRUE : VVAL_FALSE;
2581 		}
2582 		else
2583 		{
2584 		    rettv->v_type = VAR_NUMBER;
2585 		    rettv->vval.v_number = result;
2586 		}
2587 	    }
2588 
2589 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2590 	}
2591 
2592 	if (evalarg == NULL)
2593 	    clear_evalarg(&local_evalarg, NULL);
2594 	else
2595 	    evalarg->eval_flags = orig_flags;
2596     }
2597 
2598     return OK;
2599 }
2600 
2601 /*
2602  * Handle second level expression:
2603  *	expr3 && expr3 && expr3	    logical AND
2604  *
2605  * "arg" must point to the first non-white of the expression.
2606  * "arg" is advanced to just after the recognized expression.
2607  *
2608  * Return OK or FAIL.
2609  */
2610     static int
2611 eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2612 {
2613     char_u	*p;
2614     int		getnext;
2615 
2616     /*
2617      * Get the first variable.
2618      */
2619     if (eval4(arg, rettv, evalarg) == FAIL)
2620 	return FAIL;
2621 
2622     /*
2623      * Handle the "&&" operator.
2624      */
2625     p = eval_next_non_blank(*arg, evalarg, &getnext);
2626     if (p[0] == '&' && p[1] == '&')
2627     {
2628 	evalarg_T   *evalarg_used = evalarg;
2629 	evalarg_T   local_evalarg;
2630 	int	    orig_flags;
2631 	int	    evaluate;
2632 	long	    result = TRUE;
2633 	typval_T    var2;
2634 	int	    error = FALSE;
2635 	int	    vim9script = in_vim9script();
2636 
2637 	if (evalarg == NULL)
2638 	{
2639 	    CLEAR_FIELD(local_evalarg);
2640 	    evalarg_used = &local_evalarg;
2641 	}
2642 	orig_flags = evalarg_used->eval_flags;
2643 	evaluate = orig_flags & EVAL_EVALUATE;
2644 	if (evaluate)
2645 	{
2646 	    if (vim9script)
2647 		result = tv_get_bool_chk(rettv, &error);
2648 	    else if (tv_get_number_chk(rettv, &error) == 0)
2649 		result = FALSE;
2650 	    clear_tv(rettv);
2651 	    if (error)
2652 		return FAIL;
2653 	}
2654 
2655 	/*
2656 	 * Repeat until there is no following "&&".
2657 	 */
2658 	while (p[0] == '&' && p[1] == '&')
2659 	{
2660 	    if (getnext)
2661 		*arg = eval_next_line(evalarg_used);
2662 	    else
2663 	    {
2664 		if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2665 		{
2666 		    error_white_both(p, 2);
2667 		    clear_tv(rettv);
2668 		    return FAIL;
2669 		}
2670 		*arg = p;
2671 	    }
2672 
2673 	    /*
2674 	     * Get the second variable.
2675 	     */
2676 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2677 	    {
2678 		error_white_both(*arg, 2);
2679 		clear_tv(rettv);
2680 		return FAIL;
2681 	    }
2682 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2683 	    evalarg_used->eval_flags = result ? orig_flags
2684 						 : orig_flags & ~EVAL_EVALUATE;
2685 	    CLEAR_FIELD(var2);
2686 	    if (eval4(arg, &var2, evalarg_used) == FAIL)
2687 		return FAIL;
2688 
2689 	    /*
2690 	     * Compute the result.
2691 	     */
2692 	    if (evaluate && result)
2693 	    {
2694 		if (vim9script)
2695 		    result = tv_get_bool_chk(&var2, &error);
2696 		else if (tv_get_number_chk(&var2, &error) == 0)
2697 		    result = FALSE;
2698 		clear_tv(&var2);
2699 		if (error)
2700 		    return FAIL;
2701 	    }
2702 	    if (evaluate)
2703 	    {
2704 		if (vim9script)
2705 		{
2706 		    rettv->v_type = VAR_BOOL;
2707 		    rettv->vval.v_number = result ? VVAL_TRUE : VVAL_FALSE;
2708 		}
2709 		else
2710 		{
2711 		    rettv->v_type = VAR_NUMBER;
2712 		    rettv->vval.v_number = result;
2713 		}
2714 	    }
2715 
2716 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2717 	}
2718 
2719 	if (evalarg == NULL)
2720 	    clear_evalarg(&local_evalarg, NULL);
2721 	else
2722 	    evalarg->eval_flags = orig_flags;
2723     }
2724 
2725     return OK;
2726 }
2727 
2728 /*
2729  * Handle third level expression:
2730  *	var1 == var2
2731  *	var1 =~ var2
2732  *	var1 != var2
2733  *	var1 !~ var2
2734  *	var1 > var2
2735  *	var1 >= var2
2736  *	var1 < var2
2737  *	var1 <= var2
2738  *	var1 is var2
2739  *	var1 isnot var2
2740  *
2741  * "arg" must point to the first non-white of the expression.
2742  * "arg" is advanced to just after the recognized expression.
2743  *
2744  * Return OK or FAIL.
2745  */
2746     static int
2747 eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2748 {
2749     char_u	*p;
2750     int		getnext;
2751     exprtype_T	type = EXPR_UNKNOWN;
2752     int		len = 2;
2753     int		type_is = FALSE;
2754 
2755     /*
2756      * Get the first variable.
2757      */
2758     if (eval5(arg, rettv, evalarg) == FAIL)
2759 	return FAIL;
2760 
2761     p = eval_next_non_blank(*arg, evalarg, &getnext);
2762     type = get_compare_type(p, &len, &type_is);
2763 
2764     /*
2765      * If there is a comparative operator, use it.
2766      */
2767     if (type != EXPR_UNKNOWN)
2768     {
2769 	typval_T    var2;
2770 	int	    ic;
2771 	int	    vim9script = in_vim9script();
2772 	int	    evaluate = evalarg == NULL
2773 				   ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2774 
2775 	if (getnext)
2776 	{
2777 	    *arg = eval_next_line(evalarg);
2778 	    p = *arg;
2779 	}
2780 	else if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2781 	{
2782 	    error_white_both(*arg, len);
2783 	    clear_tv(rettv);
2784 	    return FAIL;
2785 	}
2786 
2787 	if (vim9script && type_is && (p[len] == '?' || p[len] == '#'))
2788 	{
2789 	    semsg(_(e_invalid_expression_str), p);
2790 	    clear_tv(rettv);
2791 	    return FAIL;
2792 	}
2793 
2794 	// extra question mark appended: ignore case
2795 	if (p[len] == '?')
2796 	{
2797 	    ic = TRUE;
2798 	    ++len;
2799 	}
2800 	// extra '#' appended: match case
2801 	else if (p[len] == '#')
2802 	{
2803 	    ic = FALSE;
2804 	    ++len;
2805 	}
2806 	// nothing appended: use 'ignorecase' if not in Vim script
2807 	else
2808 	    ic = vim9script ? FALSE : p_ic;
2809 
2810 	/*
2811 	 * Get the second variable.
2812 	 */
2813 	if (evaluate && vim9script && !IS_WHITE_OR_NUL(p[len]))
2814 	{
2815 	    error_white_both(p, len);
2816 	    clear_tv(rettv);
2817 	    return FAIL;
2818 	}
2819 	*arg = skipwhite_and_linebreak(p + len, evalarg);
2820 	if (eval5(arg, &var2, evalarg) == FAIL)
2821 	{
2822 	    clear_tv(rettv);
2823 	    return FAIL;
2824 	}
2825 	if (evaluate)
2826 	{
2827 	    int ret;
2828 
2829 	    if (vim9script && check_compare_types(type, rettv, &var2) == FAIL)
2830 	    {
2831 		ret = FAIL;
2832 		clear_tv(rettv);
2833 	    }
2834 	    else
2835 		ret = typval_compare(rettv, &var2, type, ic);
2836 	    clear_tv(&var2);
2837 	    return ret;
2838 	}
2839     }
2840 
2841     return OK;
2842 }
2843 
2844 /*
2845  * Make a copy of blob "tv1" and append blob "tv2".
2846  */
2847     void
2848 eval_addblob(typval_T *tv1, typval_T *tv2)
2849 {
2850     blob_T  *b1 = tv1->vval.v_blob;
2851     blob_T  *b2 = tv2->vval.v_blob;
2852     blob_T  *b = blob_alloc();
2853     int	    i;
2854 
2855     if (b != NULL)
2856     {
2857 	for (i = 0; i < blob_len(b1); i++)
2858 	    ga_append(&b->bv_ga, blob_get(b1, i));
2859 	for (i = 0; i < blob_len(b2); i++)
2860 	    ga_append(&b->bv_ga, blob_get(b2, i));
2861 
2862 	clear_tv(tv1);
2863 	rettv_blob_set(tv1, b);
2864     }
2865 }
2866 
2867 /*
2868  * Make a copy of list "tv1" and append list "tv2".
2869  */
2870     int
2871 eval_addlist(typval_T *tv1, typval_T *tv2)
2872 {
2873     typval_T var3;
2874 
2875     // concatenate Lists
2876     if (list_concat(tv1->vval.v_list, tv2->vval.v_list, &var3) == FAIL)
2877     {
2878 	clear_tv(tv1);
2879 	clear_tv(tv2);
2880 	return FAIL;
2881     }
2882     clear_tv(tv1);
2883     *tv1 = var3;
2884     return OK;
2885 }
2886 
2887 /*
2888  * Handle fourth level expression:
2889  *	+	number addition
2890  *	-	number subtraction
2891  *	.	string concatenation (if script version is 1)
2892  *	..	string concatenation
2893  *
2894  * "arg" must point to the first non-white of the expression.
2895  * "arg" is advanced to just after the recognized expression.
2896  *
2897  * Return OK or FAIL.
2898  */
2899     static int
2900 eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2901 {
2902     /*
2903      * Get the first variable.
2904      */
2905     if (eval6(arg, rettv, evalarg, FALSE) == FAIL)
2906 	return FAIL;
2907 
2908     /*
2909      * Repeat computing, until no '+', '-' or '.' is following.
2910      */
2911     for (;;)
2912     {
2913 	int	    evaluate;
2914 	int	    getnext;
2915 	char_u	    *p;
2916 	int	    op;
2917 	int	    oplen;
2918 	int	    concat;
2919 	typval_T    var2;
2920 	int	    vim9script = in_vim9script();
2921 
2922 	// "." is only string concatenation when scriptversion is 1
2923 	// "+=", "-=" and "..=" are assignments
2924 	// "++" and "--" on the next line are a separate command.
2925 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2926 	op = *p;
2927 	concat = op == '.' && (*(p + 1) == '.' || current_sctx.sc_version < 2);
2928 	if ((op != '+' && op != '-' && !concat) || p[1] == '='
2929 					       || (p[1] == '.' && p[2] == '='))
2930 	    break;
2931 	if (getnext && (op == '+' || op == '-') && p[0] == p[1])
2932 	    break;
2933 
2934 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2935 	oplen = (concat && p[1] == '.') ? 2 : 1;
2936 	if (getnext)
2937 	    *arg = eval_next_line(evalarg);
2938 	else
2939 	{
2940 	    if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2941 	    {
2942 		error_white_both(*arg, oplen);
2943 		clear_tv(rettv);
2944 		return FAIL;
2945 	    }
2946 	    *arg = p;
2947 	}
2948 	if ((op != '+' || (rettv->v_type != VAR_LIST
2949 						 && rettv->v_type != VAR_BLOB))
2950 #ifdef FEAT_FLOAT
2951 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2952 #endif
2953 		&& evaluate)
2954 	{
2955 	    int		error = FALSE;
2956 
2957 	    // For "list + ...", an illegal use of the first operand as
2958 	    // a number cannot be determined before evaluating the 2nd
2959 	    // operand: if this is also a list, all is ok.
2960 	    // For "something . ...", "something - ..." or "non-list + ...",
2961 	    // we know that the first operand needs to be a string or number
2962 	    // without evaluating the 2nd operand.  So check before to avoid
2963 	    // side effects after an error.
2964 	    if (op != '.')
2965 		tv_get_number_chk(rettv, &error);
2966 	    if ((op == '.' && tv_get_string_chk(rettv) == NULL) || error)
2967 	    {
2968 		clear_tv(rettv);
2969 		return FAIL;
2970 	    }
2971 	}
2972 
2973 	/*
2974 	 * Get the second variable.
2975 	 */
2976 	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[oplen]))
2977 	{
2978 	    error_white_both(*arg, oplen);
2979 	    clear_tv(rettv);
2980 	    return FAIL;
2981 	}
2982 	*arg = skipwhite_and_linebreak(*arg + oplen, evalarg);
2983 	if (eval6(arg, &var2, evalarg, !vim9script && op == '.') == FAIL)
2984 	{
2985 	    clear_tv(rettv);
2986 	    return FAIL;
2987 	}
2988 
2989 	if (evaluate)
2990 	{
2991 	    /*
2992 	     * Compute the result.
2993 	     */
2994 	    if (op == '.')
2995 	    {
2996 		char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
2997 		char_u	*s1 = tv_get_string_buf(rettv, buf1);
2998 		char_u	*s2 = NULL;
2999 
3000 		if (vim9script && (var2.v_type == VAR_VOID
3001 			|| var2.v_type == VAR_CHANNEL
3002 			|| var2.v_type == VAR_JOB))
3003 		    semsg(_(e_using_invalid_value_as_string_str),
3004 						   vartype_name(var2.v_type));
3005 #ifdef FEAT_FLOAT
3006 		else if (vim9script && var2.v_type == VAR_FLOAT)
3007 		{
3008 		    vim_snprintf((char *)buf2, NUMBUFLEN, "%g",
3009 							    var2.vval.v_float);
3010 		    s2 = buf2;
3011 		}
3012 #endif
3013 		else
3014 		    s2 = tv_get_string_buf_chk(&var2, buf2);
3015 		if (s2 == NULL)		// type error ?
3016 		{
3017 		    clear_tv(rettv);
3018 		    clear_tv(&var2);
3019 		    return FAIL;
3020 		}
3021 		p = concat_str(s1, s2);
3022 		clear_tv(rettv);
3023 		rettv->v_type = VAR_STRING;
3024 		rettv->vval.v_string = p;
3025 	    }
3026 	    else if (op == '+' && rettv->v_type == VAR_BLOB
3027 						   && var2.v_type == VAR_BLOB)
3028 		eval_addblob(rettv, &var2);
3029 	    else if (op == '+' && rettv->v_type == VAR_LIST
3030 						   && var2.v_type == VAR_LIST)
3031 	    {
3032 		if (eval_addlist(rettv, &var2) == FAIL)
3033 		    return FAIL;
3034 	    }
3035 	    else
3036 	    {
3037 		int		error = FALSE;
3038 		varnumber_T	n1, n2;
3039 #ifdef FEAT_FLOAT
3040 		float_T	    f1 = 0, f2 = 0;
3041 
3042 		if (rettv->v_type == VAR_FLOAT)
3043 		{
3044 		    f1 = rettv->vval.v_float;
3045 		    n1 = 0;
3046 		}
3047 		else
3048 #endif
3049 		{
3050 		    n1 = tv_get_number_chk(rettv, &error);
3051 		    if (error)
3052 		    {
3053 			// This can only happen for "list + non-list" or
3054 			// "blob + non-blob".  For "non-list + ..." or
3055 			// "something - ...", we returned before evaluating the
3056 			// 2nd operand.
3057 			clear_tv(rettv);
3058 			clear_tv(&var2);
3059 			return FAIL;
3060 		    }
3061 #ifdef FEAT_FLOAT
3062 		    if (var2.v_type == VAR_FLOAT)
3063 			f1 = n1;
3064 #endif
3065 		}
3066 #ifdef FEAT_FLOAT
3067 		if (var2.v_type == VAR_FLOAT)
3068 		{
3069 		    f2 = var2.vval.v_float;
3070 		    n2 = 0;
3071 		}
3072 		else
3073 #endif
3074 		{
3075 		    n2 = tv_get_number_chk(&var2, &error);
3076 		    if (error)
3077 		    {
3078 			clear_tv(rettv);
3079 			clear_tv(&var2);
3080 			return FAIL;
3081 		    }
3082 #ifdef FEAT_FLOAT
3083 		    if (rettv->v_type == VAR_FLOAT)
3084 			f2 = n2;
3085 #endif
3086 		}
3087 		clear_tv(rettv);
3088 
3089 #ifdef FEAT_FLOAT
3090 		// If there is a float on either side the result is a float.
3091 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3092 		{
3093 		    if (op == '+')
3094 			f1 = f1 + f2;
3095 		    else
3096 			f1 = f1 - f2;
3097 		    rettv->v_type = VAR_FLOAT;
3098 		    rettv->vval.v_float = f1;
3099 		}
3100 		else
3101 #endif
3102 		{
3103 		    if (op == '+')
3104 			n1 = n1 + n2;
3105 		    else
3106 			n1 = n1 - n2;
3107 		    rettv->v_type = VAR_NUMBER;
3108 		    rettv->vval.v_number = n1;
3109 		}
3110 	    }
3111 	    clear_tv(&var2);
3112 	}
3113     }
3114     return OK;
3115 }
3116 
3117 /*
3118  * Handle fifth level expression:
3119  *	*	number multiplication
3120  *	/	number division
3121  *	%	number modulo
3122  *
3123  * "arg" must point to the first non-white of the expression.
3124  * "arg" is advanced to just after the recognized expression.
3125  *
3126  * Return OK or FAIL.
3127  */
3128     static int
3129 eval6(
3130     char_u	**arg,
3131     typval_T	*rettv,
3132     evalarg_T	*evalarg,
3133     int		want_string)  // after "." operator
3134 {
3135 #ifdef FEAT_FLOAT
3136     int	    use_float = FALSE;
3137 #endif
3138 
3139     /*
3140      * Get the first variable.
3141      */
3142     if (eval7t(arg, rettv, evalarg, want_string) == FAIL)
3143 	return FAIL;
3144 
3145     /*
3146      * Repeat computing, until no '*', '/' or '%' is following.
3147      */
3148     for (;;)
3149     {
3150 	int	    evaluate;
3151 	int	    getnext;
3152 	typval_T    var2;
3153 	char_u	    *p;
3154 	int	    op;
3155 	varnumber_T n1, n2;
3156 #ifdef FEAT_FLOAT
3157 	float_T	    f1, f2;
3158 #endif
3159 	int	    error;
3160 
3161 	// "*=", "/=" and "%=" are assignments
3162 	p = eval_next_non_blank(*arg, evalarg, &getnext);
3163 	op = *p;
3164 	if ((op != '*' && op != '/' && op != '%') || p[1] == '=')
3165 	    break;
3166 
3167 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
3168 	if (getnext)
3169 	    *arg = eval_next_line(evalarg);
3170 	else
3171 	{
3172 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(**arg))
3173 	    {
3174 		error_white_both(*arg, 1);
3175 		clear_tv(rettv);
3176 		return FAIL;
3177 	    }
3178 	    *arg = p;
3179 	}
3180 
3181 #ifdef FEAT_FLOAT
3182 	f1 = 0;
3183 	f2 = 0;
3184 #endif
3185 	error = FALSE;
3186 	if (evaluate)
3187 	{
3188 #ifdef FEAT_FLOAT
3189 	    if (rettv->v_type == VAR_FLOAT)
3190 	    {
3191 		f1 = rettv->vval.v_float;
3192 		use_float = TRUE;
3193 		n1 = 0;
3194 	    }
3195 	    else
3196 #endif
3197 		n1 = tv_get_number_chk(rettv, &error);
3198 	    clear_tv(rettv);
3199 	    if (error)
3200 		return FAIL;
3201 	}
3202 	else
3203 	    n1 = 0;
3204 
3205 	/*
3206 	 * Get the second variable.
3207 	 */
3208 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[1]))
3209 	{
3210 	    error_white_both(*arg, 1);
3211 	    clear_tv(rettv);
3212 	    return FAIL;
3213 	}
3214 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3215 	if (eval7t(arg, &var2, evalarg, FALSE) == FAIL)
3216 	    return FAIL;
3217 
3218 	if (evaluate)
3219 	{
3220 #ifdef FEAT_FLOAT
3221 	    if (var2.v_type == VAR_FLOAT)
3222 	    {
3223 		if (!use_float)
3224 		{
3225 		    f1 = n1;
3226 		    use_float = TRUE;
3227 		}
3228 		f2 = var2.vval.v_float;
3229 		n2 = 0;
3230 	    }
3231 	    else
3232 #endif
3233 	    {
3234 		n2 = tv_get_number_chk(&var2, &error);
3235 		clear_tv(&var2);
3236 		if (error)
3237 		    return FAIL;
3238 #ifdef FEAT_FLOAT
3239 		if (use_float)
3240 		    f2 = n2;
3241 #endif
3242 	    }
3243 
3244 	    /*
3245 	     * Compute the result.
3246 	     * When either side is a float the result is a float.
3247 	     */
3248 #ifdef FEAT_FLOAT
3249 	    if (use_float)
3250 	    {
3251 		if (op == '*')
3252 		    f1 = f1 * f2;
3253 		else if (op == '/')
3254 		{
3255 # ifdef VMS
3256 		    // VMS crashes on divide by zero, work around it
3257 		    if (f2 == 0.0)
3258 		    {
3259 			if (f1 == 0)
3260 			    f1 = -1 * __F_FLT_MAX - 1L;   // similar to NaN
3261 			else if (f1 < 0)
3262 			    f1 = -1 * __F_FLT_MAX;
3263 			else
3264 			    f1 = __F_FLT_MAX;
3265 		    }
3266 		    else
3267 			f1 = f1 / f2;
3268 # else
3269 		    // We rely on the floating point library to handle divide
3270 		    // by zero to result in "inf" and not a crash.
3271 		    f1 = f1 / f2;
3272 # endif
3273 		}
3274 		else
3275 		{
3276 		    emsg(_(e_modulus));
3277 		    return FAIL;
3278 		}
3279 		rettv->v_type = VAR_FLOAT;
3280 		rettv->vval.v_float = f1;
3281 	    }
3282 	    else
3283 #endif
3284 	    {
3285 		int	    failed = FALSE;
3286 
3287 		if (op == '*')
3288 		    n1 = n1 * n2;
3289 		else if (op == '/')
3290 		    n1 = num_divide(n1, n2, &failed);
3291 		else
3292 		    n1 = num_modulus(n1, n2, &failed);
3293 		if (failed)
3294 		    return FAIL;
3295 
3296 		rettv->v_type = VAR_NUMBER;
3297 		rettv->vval.v_number = n1;
3298 	    }
3299 	}
3300     }
3301 
3302     return OK;
3303 }
3304 
3305 /*
3306  * Handle a type cast before a base level expression.
3307  * "arg" must point to the first non-white of the expression.
3308  * "arg" is advanced to just after the recognized expression.
3309  * Return OK or FAIL.
3310  */
3311     static int
3312 eval7t(
3313     char_u	**arg,
3314     typval_T	*rettv,
3315     evalarg_T	*evalarg,
3316     int		want_string)	// after "." operator
3317 {
3318     type_T	*want_type = NULL;
3319     garray_T	type_list;	    // list of pointers to allocated types
3320     int		res;
3321     int		evaluate = evalarg == NULL ? 0
3322 				       : (evalarg->eval_flags & EVAL_EVALUATE);
3323 
3324     // Recognize <type> in Vim9 script only.
3325     if (in_vim9script() && **arg == '<' && eval_isnamec1((*arg)[1]))
3326     {
3327 	++*arg;
3328 	ga_init2(&type_list, sizeof(type_T *), 10);
3329 	want_type = parse_type(arg, &type_list, TRUE);
3330 	if (want_type == NULL && (evaluate || **arg != '>'))
3331 	{
3332 	    clear_type_list(&type_list);
3333 	    return FAIL;
3334 	}
3335 
3336 	if (**arg != '>')
3337 	{
3338 	    if (*skipwhite(*arg) == '>')
3339 		semsg(_(e_no_white_space_allowed_before_str_str), ">", *arg);
3340 	    else
3341 		emsg(_(e_missing_gt));
3342 	    clear_type_list(&type_list);
3343 	    return FAIL;
3344 	}
3345 	++*arg;
3346 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3347     }
3348 
3349     res = eval7(arg, rettv, evalarg, want_string);
3350 
3351     if (want_type != NULL && evaluate)
3352     {
3353 	if (res == OK)
3354 	{
3355 	    type_T *actual = typval2type(rettv, get_copyID(), &type_list, TRUE);
3356 
3357 	    if (!equal_type(want_type, actual))
3358 	    {
3359 		if (want_type == &t_bool && actual != &t_bool
3360 					&& (actual->tt_flags & TTFLAG_BOOL_OK))
3361 		{
3362 		    int n = tv2bool(rettv);
3363 
3364 		    // can use "0" and "1" for boolean in some places
3365 		    clear_tv(rettv);
3366 		    rettv->v_type = VAR_BOOL;
3367 		    rettv->vval.v_number = n ? VVAL_TRUE : VVAL_FALSE;
3368 		}
3369 		else
3370 		{
3371 		    where_T where = WHERE_INIT;
3372 
3373 		    where.wt_variable = TRUE;
3374 		    res = check_type(want_type, actual, TRUE, where);
3375 		}
3376 	    }
3377 	}
3378 	clear_type_list(&type_list);
3379     }
3380 
3381     return res;
3382 }
3383 
3384     int
3385 eval_leader(char_u **arg, int vim9)
3386 {
3387     char_u	*s = *arg;
3388     char_u	*p = *arg;
3389 
3390     while (*p == '!' || *p == '-' || *p == '+')
3391     {
3392 	char_u *n = skipwhite(p + 1);
3393 
3394 	// ++, --, -+ and +- are not accepted in Vim9 script
3395 	if (vim9 && (*p == '-' || *p == '+') && (*n == '-' || *n == '+'))
3396 	{
3397 	    semsg(_(e_invalid_expression_str), s);
3398 	    return FAIL;
3399 	}
3400 	p = n;
3401     }
3402     *arg = p;
3403     return OK;
3404 }
3405 
3406 /*
3407  * Handle sixth level expression:
3408  *  number		number constant
3409  *  0zFFFFFFFF		Blob constant
3410  *  "string"		string constant
3411  *  'string'		literal string constant
3412  *  &option-name	option value
3413  *  @r			register contents
3414  *  identifier		variable value
3415  *  function()		function call
3416  *  $VAR		environment variable
3417  *  (expression)	nested expression
3418  *  [expr, expr]	List
3419  *  {arg, arg -> expr}	Lambda
3420  *  {key: val, key: val}   Dictionary
3421  *  #{key: val, key: val}  Dictionary with literal keys
3422  *
3423  *  Also handle:
3424  *  ! in front		logical NOT
3425  *  - in front		unary minus
3426  *  + in front		unary plus (ignored)
3427  *  trailing []		subscript in String or List
3428  *  trailing .name	entry in Dictionary
3429  *  trailing ->name()	method call
3430  *
3431  * "arg" must point to the first non-white of the expression.
3432  * "arg" is advanced to just after the recognized expression.
3433  *
3434  * Return OK or FAIL.
3435  */
3436     static int
3437 eval7(
3438     char_u	**arg,
3439     typval_T	*rettv,
3440     evalarg_T	*evalarg,
3441     int		want_string)	// after "." operator
3442 {
3443     int		evaluate = evalarg != NULL
3444 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3445     int		len;
3446     char_u	*s;
3447     char_u	*start_leader, *end_leader;
3448     int		ret = OK;
3449     char_u	*alias;
3450 
3451     /*
3452      * Initialise variable so that clear_tv() can't mistake this for a
3453      * string and free a string that isn't there.
3454      */
3455     rettv->v_type = VAR_UNKNOWN;
3456 
3457     /*
3458      * Skip '!', '-' and '+' characters.  They are handled later.
3459      */
3460     start_leader = *arg;
3461     if (eval_leader(arg, in_vim9script()) == FAIL)
3462 	return FAIL;
3463     end_leader = *arg;
3464 
3465     if (**arg == '.' && (!isdigit(*(*arg + 1))
3466 #ifdef FEAT_FLOAT
3467 	    || current_sctx.sc_version < 2
3468 #endif
3469 	    ))
3470     {
3471 	semsg(_(e_invalid_expression_str), *arg);
3472 	++*arg;
3473 	return FAIL;
3474     }
3475 
3476     switch (**arg)
3477     {
3478     /*
3479      * Number constant.
3480      */
3481     case '0':
3482     case '1':
3483     case '2':
3484     case '3':
3485     case '4':
3486     case '5':
3487     case '6':
3488     case '7':
3489     case '8':
3490     case '9':
3491     case '.':	ret = eval_number(arg, rettv, evaluate, want_string);
3492 
3493 		// Apply prefixed "-" and "+" now.  Matters especially when
3494 		// "->" follows.
3495 		if (ret == OK && evaluate && end_leader > start_leader
3496 						  && rettv->v_type != VAR_BLOB)
3497 		    ret = eval7_leader(rettv, TRUE, start_leader, &end_leader);
3498 		break;
3499 
3500     /*
3501      * String constant: "string".
3502      */
3503     case '"':	ret = eval_string(arg, rettv, evaluate);
3504 		break;
3505 
3506     /*
3507      * Literal string constant: 'str''ing'.
3508      */
3509     case '\'':	ret = eval_lit_string(arg, rettv, evaluate);
3510 		break;
3511 
3512     /*
3513      * List: [expr, expr]
3514      */
3515     case '[':	ret = eval_list(arg, rettv, evalarg, TRUE);
3516 		break;
3517 
3518     /*
3519      * Dictionary: #{key: val, key: val}
3520      */
3521     case '#':	if (in_vim9script())
3522 		{
3523 		    ret = vim9_bad_comment(*arg) ? FAIL : NOTDONE;
3524 		}
3525 		else if ((*arg)[1] == '{')
3526 		{
3527 		    ++*arg;
3528 		    ret = eval_dict(arg, rettv, evalarg, TRUE);
3529 		}
3530 		else
3531 		    ret = NOTDONE;
3532 		break;
3533 
3534     /*
3535      * Lambda: {arg, arg -> expr}
3536      * Dictionary: {'key': val, 'key': val}
3537      */
3538     case '{':	if (in_vim9script())
3539 		    ret = NOTDONE;
3540 		else
3541 		    ret = get_lambda_tv(arg, rettv, in_vim9script(), evalarg);
3542 		if (ret == NOTDONE)
3543 		    ret = eval_dict(arg, rettv, evalarg, FALSE);
3544 		break;
3545 
3546     /*
3547      * Option value: &name
3548      */
3549     case '&':	ret = eval_option(arg, rettv, evaluate);
3550 		break;
3551 
3552     /*
3553      * Environment variable: $VAR.
3554      */
3555     case '$':	ret = eval_env_var(arg, rettv, evaluate);
3556 		break;
3557 
3558     /*
3559      * Register contents: @r.
3560      */
3561     case '@':	++*arg;
3562 		if (evaluate)
3563 		{
3564 		    if (in_vim9script() && IS_WHITE_OR_NUL(**arg))
3565 			semsg(_(e_syntax_error_at_str), *arg);
3566 		    else if (in_vim9script() && !valid_yank_reg(**arg, FALSE))
3567 			emsg_invreg(**arg);
3568 		    else
3569 		    {
3570 			rettv->v_type = VAR_STRING;
3571 			rettv->vval.v_string = get_reg_contents(**arg,
3572 								GREG_EXPR_SRC);
3573 		    }
3574 		}
3575 		if (**arg != NUL)
3576 		    ++*arg;
3577 		break;
3578 
3579     /*
3580      * nested expression: (expression).
3581      * or lambda: (arg) => expr
3582      */
3583     case '(':	ret = NOTDONE;
3584 		if (in_vim9script())
3585 		{
3586 		    ret = get_lambda_tv(arg, rettv, TRUE, evalarg);
3587 		    if (ret == OK && evaluate)
3588 		    {
3589 			ufunc_T *ufunc = rettv->vval.v_partial->pt_func;
3590 
3591 			// Compile it here to get the return type.  The return
3592 			// type is optional, when it's missing use t_unknown.
3593 			// This is recognized in compile_return().
3594 			if (ufunc->uf_ret_type->tt_type == VAR_VOID)
3595 			    ufunc->uf_ret_type = &t_unknown;
3596 			if (compile_def_function(ufunc,
3597 				     FALSE, COMPILE_TYPE(ufunc), NULL) == FAIL)
3598 			{
3599 			    clear_tv(rettv);
3600 			    ret = FAIL;
3601 			}
3602 		    }
3603 		}
3604 		if (ret == NOTDONE)
3605 		{
3606 		    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3607 		    ret = eval1(arg, rettv, evalarg);	// recursive!
3608 
3609 		    *arg = skipwhite_and_linebreak(*arg, evalarg);
3610 		    if (**arg == ')')
3611 			++*arg;
3612 		    else if (ret == OK)
3613 		    {
3614 			emsg(_(e_missing_close));
3615 			clear_tv(rettv);
3616 			ret = FAIL;
3617 		    }
3618 		}
3619 		break;
3620 
3621     default:	ret = NOTDONE;
3622 		break;
3623     }
3624 
3625     if (ret == NOTDONE)
3626     {
3627 	/*
3628 	 * Must be a variable or function name.
3629 	 * Can also be a curly-braces kind of name: {expr}.
3630 	 */
3631 	s = *arg;
3632 	len = get_name_len(arg, &alias, evaluate, TRUE);
3633 	if (alias != NULL)
3634 	    s = alias;
3635 
3636 	if (len <= 0)
3637 	    ret = FAIL;
3638 	else
3639 	{
3640 	    int	    flags = evalarg == NULL ? 0 : evalarg->eval_flags;
3641 
3642 	    if (evaluate && in_vim9script() && len == 1 && *s == '_')
3643 	    {
3644 		emsg(_(e_cannot_use_underscore_here));
3645 		ret = FAIL;
3646 	    }
3647 	    else if ((in_vim9script() ? **arg : *skipwhite(*arg)) == '(')
3648 	    {
3649 		// "name(..."  recursive!
3650 		*arg = skipwhite(*arg);
3651 		ret = eval_func(arg, evalarg, s, len, rettv, flags, NULL);
3652 	    }
3653 	    else if (flags & EVAL_CONSTANT)
3654 		ret = FAIL;
3655 	    else if (evaluate)
3656 	    {
3657 		// get the value of "true", "false" or a variable
3658 		if (len == 4 && in_vim9script() && STRNCMP(s, "true", 4) == 0)
3659 		{
3660 		    rettv->v_type = VAR_BOOL;
3661 		    rettv->vval.v_number = VVAL_TRUE;
3662 		    ret = OK;
3663 		}
3664 		else if (len == 5 && in_vim9script()
3665 						&& STRNCMP(s, "false", 5) == 0)
3666 		{
3667 		    rettv->v_type = VAR_BOOL;
3668 		    rettv->vval.v_number = VVAL_FALSE;
3669 		    ret = OK;
3670 		}
3671 		else if (len == 4 && in_vim9script()
3672 						&& STRNCMP(s, "null", 4) == 0)
3673 		{
3674 		    rettv->v_type = VAR_SPECIAL;
3675 		    rettv->vval.v_number = VVAL_NULL;
3676 		    ret = OK;
3677 		}
3678 		else
3679 		    ret = eval_variable(s, len, rettv, NULL,
3680 					   EVAL_VAR_VERBOSE + EVAL_VAR_IMPORT);
3681 	    }
3682 	    else
3683 	    {
3684 		// skip the name
3685 		check_vars(s, len);
3686 		ret = OK;
3687 	    }
3688 	}
3689 	vim_free(alias);
3690     }
3691 
3692     // Handle following '[', '(' and '.' for expr[expr], expr.name,
3693     // expr(expr), expr->name(expr)
3694     if (ret == OK)
3695 	ret = handle_subscript(arg, rettv, evalarg, TRUE);
3696 
3697     /*
3698      * Apply logical NOT and unary '-', from right to left, ignore '+'.
3699      */
3700     if (ret == OK && evaluate && end_leader > start_leader)
3701 	ret = eval7_leader(rettv, FALSE, start_leader, &end_leader);
3702     return ret;
3703 }
3704 
3705 /*
3706  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
3707  * When "numeric_only" is TRUE only handle "+" and "-".
3708  * Adjusts "end_leaderp" until it is at "start_leader".
3709  */
3710     static int
3711 eval7_leader(
3712 	typval_T    *rettv,
3713 	int	    numeric_only,
3714 	char_u	    *start_leader,
3715 	char_u	    **end_leaderp)
3716 {
3717     char_u	*end_leader = *end_leaderp;
3718     int		ret = OK;
3719     int		error = FALSE;
3720     varnumber_T val = 0;
3721     vartype_T	type = rettv->v_type;
3722 #ifdef FEAT_FLOAT
3723     float_T	    f = 0.0;
3724 
3725     if (rettv->v_type == VAR_FLOAT)
3726 	f = rettv->vval.v_float;
3727     else
3728 #endif
3729     {
3730 	while (VIM_ISWHITE(end_leader[-1]))
3731 	    --end_leader;
3732 	if (in_vim9script() && end_leader[-1] == '!')
3733 	    val = tv2bool(rettv);
3734 	else
3735 	    val = tv_get_number_chk(rettv, &error);
3736     }
3737     if (error)
3738     {
3739 	clear_tv(rettv);
3740 	ret = FAIL;
3741     }
3742     else
3743     {
3744 	while (end_leader > start_leader)
3745 	{
3746 	    --end_leader;
3747 	    if (*end_leader == '!')
3748 	    {
3749 		if (numeric_only)
3750 		{
3751 		    ++end_leader;
3752 		    break;
3753 		}
3754 #ifdef FEAT_FLOAT
3755 		if (rettv->v_type == VAR_FLOAT)
3756 		{
3757 		    if (in_vim9script())
3758 		    {
3759 			rettv->v_type = VAR_BOOL;
3760 			val = f == 0.0 ? VVAL_TRUE : VVAL_FALSE;
3761 		    }
3762 		    else
3763 			f = !f;
3764 		}
3765 		else
3766 #endif
3767 		{
3768 		    val = !val;
3769 		    type = VAR_BOOL;
3770 		}
3771 	    }
3772 	    else if (*end_leader == '-')
3773 	    {
3774 #ifdef FEAT_FLOAT
3775 		if (rettv->v_type == VAR_FLOAT)
3776 		    f = -f;
3777 		else
3778 #endif
3779 		{
3780 		    val = -val;
3781 		    type = VAR_NUMBER;
3782 		}
3783 	    }
3784 	}
3785 #ifdef FEAT_FLOAT
3786 	if (rettv->v_type == VAR_FLOAT)
3787 	{
3788 	    clear_tv(rettv);
3789 	    rettv->vval.v_float = f;
3790 	}
3791 	else
3792 #endif
3793 	{
3794 	    clear_tv(rettv);
3795 	    if (in_vim9script())
3796 		rettv->v_type = type;
3797 	    else
3798 		rettv->v_type = VAR_NUMBER;
3799 	    rettv->vval.v_number = val;
3800 	}
3801     }
3802     *end_leaderp = end_leader;
3803     return ret;
3804 }
3805 
3806 /*
3807  * Call the function referred to in "rettv".
3808  */
3809     static int
3810 call_func_rettv(
3811 	char_u	    **arg,
3812 	evalarg_T   *evalarg,
3813 	typval_T    *rettv,
3814 	int	    evaluate,
3815 	dict_T	    *selfdict,
3816 	typval_T    *basetv)
3817 {
3818     partial_T	*pt = NULL;
3819     funcexe_T	funcexe;
3820     typval_T	functv;
3821     char_u	*s;
3822     int		ret;
3823 
3824     // need to copy the funcref so that we can clear rettv
3825     if (evaluate)
3826     {
3827 	functv = *rettv;
3828 	rettv->v_type = VAR_UNKNOWN;
3829 
3830 	// Invoke the function.  Recursive!
3831 	if (functv.v_type == VAR_PARTIAL)
3832 	{
3833 	    pt = functv.vval.v_partial;
3834 	    s = partial_name(pt);
3835 	}
3836 	else
3837 	{
3838 	    s = functv.vval.v_string;
3839 	    if (s == NULL || *s == NUL)
3840 	    {
3841 		emsg(_(e_empty_function_name));
3842 		ret = FAIL;
3843 		goto theend;
3844 	    }
3845 	}
3846     }
3847     else
3848 	s = (char_u *)"";
3849 
3850     CLEAR_FIELD(funcexe);
3851     funcexe.firstline = curwin->w_cursor.lnum;
3852     funcexe.lastline = curwin->w_cursor.lnum;
3853     funcexe.evaluate = evaluate;
3854     funcexe.partial = pt;
3855     funcexe.selfdict = selfdict;
3856     funcexe.basetv = basetv;
3857     ret = get_func_tv(s, -1, rettv, arg, evalarg, &funcexe);
3858 
3859 theend:
3860     // Clear the funcref afterwards, so that deleting it while
3861     // evaluating the arguments is possible (see test55).
3862     if (evaluate)
3863 	clear_tv(&functv);
3864 
3865     return ret;
3866 }
3867 
3868 /*
3869  * Evaluate "->method()".
3870  * "*arg" points to "method".
3871  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3872  */
3873     static int
3874 eval_lambda(
3875     char_u	**arg,
3876     typval_T	*rettv,
3877     evalarg_T	*evalarg,
3878     int		verbose)	// give error messages
3879 {
3880     int		evaluate = evalarg != NULL
3881 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3882     typval_T	base = *rettv;
3883     int		ret;
3884 
3885     rettv->v_type = VAR_UNKNOWN;
3886 
3887     if (**arg == '{')
3888     {
3889 	// ->{lambda}()
3890 	ret = get_lambda_tv(arg, rettv, FALSE, evalarg);
3891     }
3892     else
3893     {
3894 	// ->(lambda)()
3895 	++*arg;
3896 	ret = eval1(arg, rettv, evalarg);
3897 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3898 	if (**arg != ')')
3899 	{
3900 	    emsg(_(e_missing_close));
3901 	    ret = FAIL;
3902 	}
3903 	++*arg;
3904     }
3905     if (ret != OK)
3906 	return FAIL;
3907     else if (**arg != '(')
3908     {
3909 	if (verbose)
3910 	{
3911 	    if (*skipwhite(*arg) == '(')
3912 		emsg(_(e_nowhitespace));
3913 	    else
3914 		semsg(_(e_missing_paren), "lambda");
3915 	}
3916 	clear_tv(rettv);
3917 	ret = FAIL;
3918     }
3919     else
3920 	ret = call_func_rettv(arg, evalarg, rettv, evaluate, NULL, &base);
3921 
3922     // Clear the funcref afterwards, so that deleting it while
3923     // evaluating the arguments is possible (see test55).
3924     if (evaluate)
3925 	clear_tv(&base);
3926 
3927     return ret;
3928 }
3929 
3930 /*
3931  * Evaluate "->method()".
3932  * "*arg" points to "method".
3933  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3934  */
3935     static int
3936 eval_method(
3937     char_u	**arg,
3938     typval_T	*rettv,
3939     evalarg_T	*evalarg,
3940     int		verbose)	// give error messages
3941 {
3942     char_u	*name;
3943     long	len;
3944     char_u	*alias;
3945     typval_T	base = *rettv;
3946     int		ret;
3947     int		evaluate = evalarg != NULL
3948 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3949 
3950     rettv->v_type = VAR_UNKNOWN;
3951 
3952     name = *arg;
3953     len = get_name_len(arg, &alias, evaluate, TRUE);
3954     if (alias != NULL)
3955 	name = alias;
3956 
3957     if (len <= 0)
3958     {
3959 	if (verbose)
3960 	    emsg(_("E260: Missing name after ->"));
3961 	ret = FAIL;
3962     }
3963     else
3964     {
3965 	*arg = skipwhite(*arg);
3966 	if (**arg != '(')
3967 	{
3968 	    if (verbose)
3969 		semsg(_(e_missing_paren), name);
3970 	    ret = FAIL;
3971 	}
3972 	else if (VIM_ISWHITE((*arg)[-1]))
3973 	{
3974 	    if (verbose)
3975 		emsg(_(e_nowhitespace));
3976 	    ret = FAIL;
3977 	}
3978 	else
3979 	    ret = eval_func(arg, evalarg, name, len, rettv,
3980 					  evaluate ? EVAL_EVALUATE : 0, &base);
3981     }
3982 
3983     // Clear the funcref afterwards, so that deleting it while
3984     // evaluating the arguments is possible (see test55).
3985     if (evaluate)
3986 	clear_tv(&base);
3987 
3988     return ret;
3989 }
3990 
3991 /*
3992  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
3993  * "*arg" points to the '[' or '.'.
3994  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
3995  */
3996     static int
3997 eval_index(
3998     char_u	**arg,
3999     typval_T	*rettv,
4000     evalarg_T	*evalarg,
4001     int		verbose)	// give error messages
4002 {
4003     int		evaluate = evalarg != NULL
4004 				      && (evalarg->eval_flags & EVAL_EVALUATE);
4005     int		empty1 = FALSE, empty2 = FALSE;
4006     typval_T	var1, var2;
4007     int		range = FALSE;
4008     char_u	*key = NULL;
4009     int		keylen = -1;
4010     int		vim9 = in_vim9script();
4011 
4012     if (check_can_index(rettv, evaluate, verbose) == FAIL)
4013 	return FAIL;
4014 
4015     init_tv(&var1);
4016     init_tv(&var2);
4017     if (**arg == '.')
4018     {
4019 	/*
4020 	 * dict.name
4021 	 */
4022 	key = *arg + 1;
4023 	for (keylen = 0; eval_isdictc(key[keylen]); ++keylen)
4024 	    ;
4025 	if (keylen == 0)
4026 	    return FAIL;
4027 	*arg = key + keylen;
4028     }
4029     else
4030     {
4031 	/*
4032 	 * something[idx]
4033 	 *
4034 	 * Get the (first) variable from inside the [].
4035 	 */
4036 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
4037 	if (**arg == ':')
4038 	    empty1 = TRUE;
4039 	else if (eval1(arg, &var1, evalarg) == FAIL)	// recursive!
4040 	    return FAIL;
4041 	else if (vim9 && **arg == ':')
4042 	{
4043 	    semsg(_(e_white_space_required_before_and_after_str_at_str),
4044 								    ":", *arg);
4045 	    clear_tv(&var1);
4046 	    return FAIL;
4047 	}
4048 	else if (evaluate)
4049 	{
4050 #ifdef FEAT_FLOAT
4051 	    // allow for indexing with float
4052 	    if (vim9 && rettv->v_type == VAR_DICT
4053 						   && var1.v_type == VAR_FLOAT)
4054 	    {
4055 		var1.vval.v_string = typval_tostring(&var1, TRUE);
4056 		var1.v_type = VAR_STRING;
4057 	    }
4058 #endif
4059 	    if (tv_get_string_chk(&var1) == NULL)
4060 	    {
4061 		// not a number or string
4062 		clear_tv(&var1);
4063 		return FAIL;
4064 	    }
4065 	}
4066 
4067 	/*
4068 	 * Get the second variable from inside the [:].
4069 	 */
4070 	*arg = skipwhite_and_linebreak(*arg, evalarg);
4071 	if (**arg == ':')
4072 	{
4073 	    range = TRUE;
4074 	    ++*arg;
4075 	    if (vim9 && !IS_WHITE_OR_NUL(**arg) && **arg != ']')
4076 	    {
4077 		semsg(_(e_white_space_required_before_and_after_str_at_str),
4078 								":", *arg - 1);
4079 		if (!empty1)
4080 		    clear_tv(&var1);
4081 		return FAIL;
4082 	    }
4083 	    *arg = skipwhite_and_linebreak(*arg, evalarg);
4084 	    if (**arg == ']')
4085 		empty2 = TRUE;
4086 	    else if (eval1(arg, &var2, evalarg) == FAIL)	// recursive!
4087 	    {
4088 		if (!empty1)
4089 		    clear_tv(&var1);
4090 		return FAIL;
4091 	    }
4092 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
4093 	    {
4094 		// not a number or string
4095 		if (!empty1)
4096 		    clear_tv(&var1);
4097 		clear_tv(&var2);
4098 		return FAIL;
4099 	    }
4100 	}
4101 
4102 	// Check for the ']'.
4103 	*arg = skipwhite_and_linebreak(*arg, evalarg);
4104 	if (**arg != ']')
4105 	{
4106 	    if (verbose)
4107 		emsg(_(e_missbrac));
4108 	    clear_tv(&var1);
4109 	    if (range)
4110 		clear_tv(&var2);
4111 	    return FAIL;
4112 	}
4113 	*arg = *arg + 1;	// skip over the ']'
4114     }
4115 
4116     if (evaluate)
4117     {
4118 	int res = eval_index_inner(rettv, range,
4119 		empty1 ? NULL : &var1, empty2 ? NULL : &var2, FALSE,
4120 		key, keylen, verbose);
4121 
4122 	if (!empty1)
4123 	    clear_tv(&var1);
4124 	if (range)
4125 	    clear_tv(&var2);
4126 	return res;
4127     }
4128     return OK;
4129 }
4130 
4131 /*
4132  * Check if "rettv" can have an [index] or [sli:ce]
4133  */
4134     int
4135 check_can_index(typval_T *rettv, int evaluate, int verbose)
4136 {
4137     switch (rettv->v_type)
4138     {
4139 	case VAR_FUNC:
4140 	case VAR_PARTIAL:
4141 	    if (verbose)
4142 		emsg(_("E695: Cannot index a Funcref"));
4143 	    return FAIL;
4144 	case VAR_FLOAT:
4145 #ifdef FEAT_FLOAT
4146 	    if (verbose)
4147 		emsg(_(e_float_as_string));
4148 	    return FAIL;
4149 #endif
4150 	case VAR_BOOL:
4151 	case VAR_SPECIAL:
4152 	case VAR_JOB:
4153 	case VAR_CHANNEL:
4154 	case VAR_INSTR:
4155 	    if (verbose)
4156 		emsg(_(e_cannot_index_special_variable));
4157 	    return FAIL;
4158 	case VAR_UNKNOWN:
4159 	case VAR_ANY:
4160 	case VAR_VOID:
4161 	    if (evaluate)
4162 	    {
4163 		emsg(_(e_cannot_index_special_variable));
4164 		return FAIL;
4165 	    }
4166 	    // FALLTHROUGH
4167 
4168 	case VAR_STRING:
4169 	case VAR_LIST:
4170 	case VAR_DICT:
4171 	case VAR_BLOB:
4172 	    break;
4173 	case VAR_NUMBER:
4174 	    if (in_vim9script())
4175 		emsg(_(e_cannot_index_number));
4176 	    break;
4177     }
4178     return OK;
4179 }
4180 
4181 /*
4182  * slice() function
4183  */
4184     void
4185 f_slice(typval_T *argvars, typval_T *rettv)
4186 {
4187     if (in_vim9script()
4188 	    && ((argvars[0].v_type != VAR_LIST
4189 		    && argvars[0].v_type != VAR_BLOB
4190 		    && argvars[0].v_type != VAR_STRING
4191 		    && check_for_list_arg(argvars, 0) == FAIL)
4192 		|| check_for_number_arg(argvars, 1) == FAIL
4193 		|| check_for_opt_number_arg(argvars, 2) == FAIL))
4194 	return;
4195 
4196     if (check_can_index(argvars, TRUE, FALSE) == OK)
4197     {
4198 	copy_tv(argvars, rettv);
4199 	eval_index_inner(rettv, TRUE, argvars + 1,
4200 		argvars[2].v_type == VAR_UNKNOWN ? NULL : argvars + 2,
4201 		TRUE, NULL, 0, FALSE);
4202     }
4203 }
4204 
4205 /*
4206  * Apply index or range to "rettv".
4207  * "var1" is the first index, NULL for [:expr].
4208  * "var2" is the second index, NULL for [expr] and [expr: ]
4209  * "exclusive" is TRUE for slice(): second index is exclusive, use character
4210  * index for string.
4211  * Alternatively, "key" is not NULL, then key[keylen] is the dict index.
4212  */
4213     int
4214 eval_index_inner(
4215 	typval_T    *rettv,
4216 	int	    is_range,
4217 	typval_T    *var1,
4218 	typval_T    *var2,
4219 	int	    exclusive,
4220 	char_u	    *key,
4221 	int	    keylen,
4222 	int	    verbose)
4223 {
4224     varnumber_T	    n1, n2 = 0;
4225     long	    len;
4226 
4227     n1 = 0;
4228     if (var1 != NULL && rettv->v_type != VAR_DICT)
4229 	n1 = tv_get_number(var1);
4230 
4231     if (is_range)
4232     {
4233 	if (rettv->v_type == VAR_DICT)
4234 	{
4235 	    if (verbose)
4236 		emsg(_(e_cannot_slice_dictionary));
4237 	    return FAIL;
4238 	}
4239 	if (var2 != NULL)
4240 	    n2 = tv_get_number(var2);
4241 	else
4242 	    n2 = VARNUM_MAX;
4243     }
4244 
4245     switch (rettv->v_type)
4246     {
4247 	case VAR_UNKNOWN:
4248 	case VAR_ANY:
4249 	case VAR_VOID:
4250 	case VAR_FUNC:
4251 	case VAR_PARTIAL:
4252 	case VAR_FLOAT:
4253 	case VAR_BOOL:
4254 	case VAR_SPECIAL:
4255 	case VAR_JOB:
4256 	case VAR_CHANNEL:
4257 	case VAR_INSTR:
4258 	    break; // not evaluating, skipping over subscript
4259 
4260 	case VAR_NUMBER:
4261 	case VAR_STRING:
4262 	    {
4263 		char_u	*s = tv_get_string(rettv);
4264 
4265 		len = (long)STRLEN(s);
4266 		if (in_vim9script() || exclusive)
4267 		{
4268 		    if (is_range)
4269 			s = string_slice(s, n1, n2, exclusive);
4270 		    else
4271 			s = char_from_string(s, n1);
4272 		}
4273 		else if (is_range)
4274 		{
4275 		    // The resulting variable is a substring.  If the indexes
4276 		    // are out of range the result is empty.
4277 		    if (n1 < 0)
4278 		    {
4279 			n1 = len + n1;
4280 			if (n1 < 0)
4281 			    n1 = 0;
4282 		    }
4283 		    if (n2 < 0)
4284 			n2 = len + n2;
4285 		    else if (n2 >= len)
4286 			n2 = len;
4287 		    if (n1 >= len || n2 < 0 || n1 > n2)
4288 			s = NULL;
4289 		    else
4290 			s = vim_strnsave(s + n1, n2 - n1 + 1);
4291 		}
4292 		else
4293 		{
4294 		    // The resulting variable is a string of a single
4295 		    // character.  If the index is too big or negative the
4296 		    // result is empty.
4297 		    if (n1 >= len || n1 < 0)
4298 			s = NULL;
4299 		    else
4300 			s = vim_strnsave(s + n1, 1);
4301 		}
4302 		clear_tv(rettv);
4303 		rettv->v_type = VAR_STRING;
4304 		rettv->vval.v_string = s;
4305 	    }
4306 	    break;
4307 
4308 	case VAR_BLOB:
4309 	    blob_slice_or_index(rettv->vval.v_blob, is_range, n1, n2,
4310 							     exclusive, rettv);
4311 	    break;
4312 
4313 	case VAR_LIST:
4314 	    if (var1 == NULL)
4315 		n1 = 0;
4316 	    if (var2 == NULL)
4317 		n2 = VARNUM_MAX;
4318 	    if (list_slice_or_index(rettv->vval.v_list,
4319 			  is_range, n1, n2, exclusive, rettv, verbose) == FAIL)
4320 		return FAIL;
4321 	    break;
4322 
4323 	case VAR_DICT:
4324 	    {
4325 		dictitem_T	*item;
4326 		typval_T	tmp;
4327 
4328 		if (key == NULL)
4329 		{
4330 		    key = tv_get_string_chk(var1);
4331 		    if (key == NULL)
4332 			return FAIL;
4333 		}
4334 
4335 		item = dict_find(rettv->vval.v_dict, key, (int)keylen);
4336 
4337 		if (item == NULL && verbose)
4338 		    semsg(_(e_dictkey), key);
4339 		if (item == NULL)
4340 		    return FAIL;
4341 
4342 		copy_tv(&item->di_tv, &tmp);
4343 		clear_tv(rettv);
4344 		*rettv = tmp;
4345 	    }
4346 	    break;
4347     }
4348     return OK;
4349 }
4350 
4351 /*
4352  * Return the function name of partial "pt".
4353  */
4354     char_u *
4355 partial_name(partial_T *pt)
4356 {
4357     if (pt != NULL)
4358     {
4359 	if (pt->pt_name != NULL)
4360 	    return pt->pt_name;
4361 	if (pt->pt_func != NULL)
4362 	    return pt->pt_func->uf_name;
4363     }
4364     return (char_u *)"";
4365 }
4366 
4367     static void
4368 partial_free(partial_T *pt)
4369 {
4370     int i;
4371 
4372     for (i = 0; i < pt->pt_argc; ++i)
4373 	clear_tv(&pt->pt_argv[i]);
4374     vim_free(pt->pt_argv);
4375     dict_unref(pt->pt_dict);
4376     if (pt->pt_name != NULL)
4377     {
4378 	func_unref(pt->pt_name);
4379 	vim_free(pt->pt_name);
4380     }
4381     else
4382 	func_ptr_unref(pt->pt_func);
4383 
4384     // "out_up" is no longer used, decrement refcount on partial that owns it.
4385     partial_unref(pt->pt_outer.out_up_partial);
4386 
4387     // Decrease the reference count for the context of a closure.  If down
4388     // to the minimum it may be time to free it.
4389     if (pt->pt_funcstack != NULL)
4390     {
4391 	--pt->pt_funcstack->fs_refcount;
4392 	funcstack_check_refcount(pt->pt_funcstack);
4393     }
4394 
4395     vim_free(pt);
4396 }
4397 
4398 /*
4399  * Unreference a closure: decrement the reference count and free it when it
4400  * becomes zero.
4401  */
4402     void
4403 partial_unref(partial_T *pt)
4404 {
4405     if (pt != NULL)
4406     {
4407 	if (--pt->pt_refcount <= 0)
4408 	    partial_free(pt);
4409 
4410 	// If the reference count goes down to one, the funcstack may be the
4411 	// only reference and can be freed if no other partials reference it.
4412 	else if (pt->pt_refcount == 1 && pt->pt_funcstack != NULL)
4413 	    funcstack_check_refcount(pt->pt_funcstack);
4414     }
4415 }
4416 
4417 /*
4418  * Return the next (unique) copy ID.
4419  * Used for serializing nested structures.
4420  */
4421     int
4422 get_copyID(void)
4423 {
4424     current_copyID += COPYID_INC;
4425     return current_copyID;
4426 }
4427 
4428 /*
4429  * Garbage collection for lists and dictionaries.
4430  *
4431  * We use reference counts to be able to free most items right away when they
4432  * are no longer used.  But for composite items it's possible that it becomes
4433  * unused while the reference count is > 0: When there is a recursive
4434  * reference.  Example:
4435  *	:let l = [1, 2, 3]
4436  *	:let d = {9: l}
4437  *	:let l[1] = d
4438  *
4439  * Since this is quite unusual we handle this with garbage collection: every
4440  * once in a while find out which lists and dicts are not referenced from any
4441  * variable.
4442  *
4443  * Here is a good reference text about garbage collection (refers to Python
4444  * but it applies to all reference-counting mechanisms):
4445  *	http://python.ca/nas/python/gc/
4446  */
4447 
4448 /*
4449  * Do garbage collection for lists and dicts.
4450  * When "testing" is TRUE this is called from test_garbagecollect_now().
4451  * Return TRUE if some memory was freed.
4452  */
4453     int
4454 garbage_collect(int testing)
4455 {
4456     int		copyID;
4457     int		abort = FALSE;
4458     buf_T	*buf;
4459     win_T	*wp;
4460     int		did_free = FALSE;
4461     tabpage_T	*tp;
4462 
4463     if (!testing)
4464     {
4465 	// Only do this once.
4466 	want_garbage_collect = FALSE;
4467 	may_garbage_collect = FALSE;
4468 	garbage_collect_at_exit = FALSE;
4469     }
4470 
4471     // The execution stack can grow big, limit the size.
4472     if (exestack.ga_maxlen - exestack.ga_len > 500)
4473     {
4474 	size_t	new_len;
4475 	char_u	*pp;
4476 	int	n;
4477 
4478 	// Keep 150% of the current size, with a minimum of the growth size.
4479 	n = exestack.ga_len / 2;
4480 	if (n < exestack.ga_growsize)
4481 	    n = exestack.ga_growsize;
4482 
4483 	// Don't make it bigger though.
4484 	if (exestack.ga_len + n < exestack.ga_maxlen)
4485 	{
4486 	    new_len = exestack.ga_itemsize * (exestack.ga_len + n);
4487 	    pp = vim_realloc(exestack.ga_data, new_len);
4488 	    if (pp == NULL)
4489 		return FAIL;
4490 	    exestack.ga_maxlen = exestack.ga_len + n;
4491 	    exestack.ga_data = pp;
4492 	}
4493     }
4494 
4495     // We advance by two because we add one for items referenced through
4496     // previous_funccal.
4497     copyID = get_copyID();
4498 
4499     /*
4500      * 1. Go through all accessible variables and mark all lists and dicts
4501      *    with copyID.
4502      */
4503 
4504     // Don't free variables in the previous_funccal list unless they are only
4505     // referenced through previous_funccal.  This must be first, because if
4506     // the item is referenced elsewhere the funccal must not be freed.
4507     abort = abort || set_ref_in_previous_funccal(copyID);
4508 
4509     // script-local variables
4510     abort = abort || garbage_collect_scriptvars(copyID);
4511 
4512     // buffer-local variables
4513     FOR_ALL_BUFFERS(buf)
4514 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
4515 								  NULL, NULL);
4516 
4517     // window-local variables
4518     FOR_ALL_TAB_WINDOWS(tp, wp)
4519 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4520 								  NULL, NULL);
4521     if (aucmd_win != NULL)
4522 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
4523 								  NULL, NULL);
4524 #ifdef FEAT_PROP_POPUP
4525     FOR_ALL_POPUPWINS(wp)
4526 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4527 								  NULL, NULL);
4528     FOR_ALL_TABPAGES(tp)
4529 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
4530 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4531 								  NULL, NULL);
4532 #endif
4533 
4534     // tabpage-local variables
4535     FOR_ALL_TABPAGES(tp)
4536 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
4537 								  NULL, NULL);
4538     // global variables
4539     abort = abort || garbage_collect_globvars(copyID);
4540 
4541     // function-local variables
4542     abort = abort || set_ref_in_call_stack(copyID);
4543 
4544     // named functions (matters for closures)
4545     abort = abort || set_ref_in_functions(copyID);
4546 
4547     // function call arguments, if v:testing is set.
4548     abort = abort || set_ref_in_func_args(copyID);
4549 
4550     // v: vars
4551     abort = abort || garbage_collect_vimvars(copyID);
4552 
4553     // callbacks in buffers
4554     abort = abort || set_ref_in_buffers(copyID);
4555 
4556 #ifdef FEAT_LUA
4557     abort = abort || set_ref_in_lua(copyID);
4558 #endif
4559 
4560 #ifdef FEAT_PYTHON
4561     abort = abort || set_ref_in_python(copyID);
4562 #endif
4563 
4564 #ifdef FEAT_PYTHON3
4565     abort = abort || set_ref_in_python3(copyID);
4566 #endif
4567 
4568 #ifdef FEAT_JOB_CHANNEL
4569     abort = abort || set_ref_in_channel(copyID);
4570     abort = abort || set_ref_in_job(copyID);
4571 #endif
4572 #ifdef FEAT_NETBEANS_INTG
4573     abort = abort || set_ref_in_nb_channel(copyID);
4574 #endif
4575 
4576 #ifdef FEAT_TIMERS
4577     abort = abort || set_ref_in_timer(copyID);
4578 #endif
4579 
4580 #ifdef FEAT_QUICKFIX
4581     abort = abort || set_ref_in_quickfix(copyID);
4582 #endif
4583 
4584 #ifdef FEAT_TERMINAL
4585     abort = abort || set_ref_in_term(copyID);
4586 #endif
4587 
4588 #ifdef FEAT_PROP_POPUP
4589     abort = abort || set_ref_in_popups(copyID);
4590 #endif
4591 
4592     if (!abort)
4593     {
4594 	/*
4595 	 * 2. Free lists and dictionaries that are not referenced.
4596 	 */
4597 	did_free = free_unref_items(copyID);
4598 
4599 	/*
4600 	 * 3. Check if any funccal can be freed now.
4601 	 *    This may call us back recursively.
4602 	 */
4603 	free_unref_funccal(copyID, testing);
4604     }
4605     else if (p_verbose > 0)
4606     {
4607 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
4608     }
4609 
4610     return did_free;
4611 }
4612 
4613 /*
4614  * Free lists, dictionaries, channels and jobs that are no longer referenced.
4615  */
4616     static int
4617 free_unref_items(int copyID)
4618 {
4619     int		did_free = FALSE;
4620 
4621     // Let all "free" functions know that we are here.  This means no
4622     // dictionaries, lists, channels or jobs are to be freed, because we will
4623     // do that here.
4624     in_free_unref_items = TRUE;
4625 
4626     /*
4627      * PASS 1: free the contents of the items.  We don't free the items
4628      * themselves yet, so that it is possible to decrement refcount counters
4629      */
4630 
4631     // Go through the list of dicts and free items without the copyID.
4632     did_free |= dict_free_nonref(copyID);
4633 
4634     // Go through the list of lists and free items without the copyID.
4635     did_free |= list_free_nonref(copyID);
4636 
4637 #ifdef FEAT_JOB_CHANNEL
4638     // Go through the list of jobs and free items without the copyID. This
4639     // must happen before doing channels, because jobs refer to channels, but
4640     // the reference from the channel to the job isn't tracked.
4641     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4642 
4643     // Go through the list of channels and free items without the copyID.
4644     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4645 #endif
4646 
4647     /*
4648      * PASS 2: free the items themselves.
4649      */
4650     dict_free_items(copyID);
4651     list_free_items(copyID);
4652 
4653 #ifdef FEAT_JOB_CHANNEL
4654     // Go through the list of jobs and free items without the copyID. This
4655     // must happen before doing channels, because jobs refer to channels, but
4656     // the reference from the channel to the job isn't tracked.
4657     free_unused_jobs(copyID, COPYID_MASK);
4658 
4659     // Go through the list of channels and free items without the copyID.
4660     free_unused_channels(copyID, COPYID_MASK);
4661 #endif
4662 
4663     in_free_unref_items = FALSE;
4664 
4665     return did_free;
4666 }
4667 
4668 /*
4669  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4670  * "list_stack" is used to add lists to be marked.  Can be NULL.
4671  *
4672  * Returns TRUE if setting references failed somehow.
4673  */
4674     int
4675 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4676 {
4677     int		todo;
4678     int		abort = FALSE;
4679     hashitem_T	*hi;
4680     hashtab_T	*cur_ht;
4681     ht_stack_T	*ht_stack = NULL;
4682     ht_stack_T	*tempitem;
4683 
4684     cur_ht = ht;
4685     for (;;)
4686     {
4687 	if (!abort)
4688 	{
4689 	    // Mark each item in the hashtab.  If the item contains a hashtab
4690 	    // it is added to ht_stack, if it contains a list it is added to
4691 	    // list_stack.
4692 	    todo = (int)cur_ht->ht_used;
4693 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4694 		if (!HASHITEM_EMPTY(hi))
4695 		{
4696 		    --todo;
4697 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4698 						       &ht_stack, list_stack);
4699 		}
4700 	}
4701 
4702 	if (ht_stack == NULL)
4703 	    break;
4704 
4705 	// take an item from the stack
4706 	cur_ht = ht_stack->ht;
4707 	tempitem = ht_stack;
4708 	ht_stack = ht_stack->prev;
4709 	free(tempitem);
4710     }
4711 
4712     return abort;
4713 }
4714 
4715 /*
4716  * Mark a dict and its items with "copyID".
4717  * Returns TRUE if setting references failed somehow.
4718  */
4719     int
4720 set_ref_in_dict(dict_T *d, int copyID)
4721 {
4722     if (d != NULL && d->dv_copyID != copyID)
4723     {
4724 	d->dv_copyID = copyID;
4725 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4726     }
4727     return FALSE;
4728 }
4729 
4730 /*
4731  * Mark a list and its items with "copyID".
4732  * Returns TRUE if setting references failed somehow.
4733  */
4734     int
4735 set_ref_in_list(list_T *ll, int copyID)
4736 {
4737     if (ll != NULL && ll->lv_copyID != copyID)
4738     {
4739 	ll->lv_copyID = copyID;
4740 	return set_ref_in_list_items(ll, copyID, NULL);
4741     }
4742     return FALSE;
4743 }
4744 
4745 /*
4746  * Mark all lists and dicts referenced through list "l" with "copyID".
4747  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4748  *
4749  * Returns TRUE if setting references failed somehow.
4750  */
4751     int
4752 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4753 {
4754     listitem_T	 *li;
4755     int		 abort = FALSE;
4756     list_T	 *cur_l;
4757     list_stack_T *list_stack = NULL;
4758     list_stack_T *tempitem;
4759 
4760     cur_l = l;
4761     for (;;)
4762     {
4763 	if (!abort && cur_l->lv_first != &range_list_item)
4764 	    // Mark each item in the list.  If the item contains a hashtab
4765 	    // it is added to ht_stack, if it contains a list it is added to
4766 	    // list_stack.
4767 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4768 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4769 						       ht_stack, &list_stack);
4770 	if (list_stack == NULL)
4771 	    break;
4772 
4773 	// take an item from the stack
4774 	cur_l = list_stack->list;
4775 	tempitem = list_stack;
4776 	list_stack = list_stack->prev;
4777 	free(tempitem);
4778     }
4779 
4780     return abort;
4781 }
4782 
4783 /*
4784  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4785  * "list_stack" is used to add lists to be marked.  Can be NULL.
4786  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4787  *
4788  * Returns TRUE if setting references failed somehow.
4789  */
4790     int
4791 set_ref_in_item(
4792     typval_T	    *tv,
4793     int		    copyID,
4794     ht_stack_T	    **ht_stack,
4795     list_stack_T    **list_stack)
4796 {
4797     int		abort = FALSE;
4798 
4799     if (tv->v_type == VAR_DICT)
4800     {
4801 	dict_T	*dd = tv->vval.v_dict;
4802 
4803 	if (dd != NULL && dd->dv_copyID != copyID)
4804 	{
4805 	    // Didn't see this dict yet.
4806 	    dd->dv_copyID = copyID;
4807 	    if (ht_stack == NULL)
4808 	    {
4809 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4810 	    }
4811 	    else
4812 	    {
4813 		ht_stack_T *newitem = ALLOC_ONE(ht_stack_T);
4814 
4815 		if (newitem == NULL)
4816 		    abort = TRUE;
4817 		else
4818 		{
4819 		    newitem->ht = &dd->dv_hashtab;
4820 		    newitem->prev = *ht_stack;
4821 		    *ht_stack = newitem;
4822 		}
4823 	    }
4824 	}
4825     }
4826     else if (tv->v_type == VAR_LIST)
4827     {
4828 	list_T	*ll = tv->vval.v_list;
4829 
4830 	if (ll != NULL && ll->lv_copyID != copyID)
4831 	{
4832 	    // Didn't see this list yet.
4833 	    ll->lv_copyID = copyID;
4834 	    if (list_stack == NULL)
4835 	    {
4836 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4837 	    }
4838 	    else
4839 	    {
4840 		list_stack_T *newitem = ALLOC_ONE(list_stack_T);
4841 
4842 		if (newitem == NULL)
4843 		    abort = TRUE;
4844 		else
4845 		{
4846 		    newitem->list = ll;
4847 		    newitem->prev = *list_stack;
4848 		    *list_stack = newitem;
4849 		}
4850 	    }
4851 	}
4852     }
4853     else if (tv->v_type == VAR_FUNC)
4854     {
4855 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4856     }
4857     else if (tv->v_type == VAR_PARTIAL)
4858     {
4859 	partial_T	*pt = tv->vval.v_partial;
4860 	int		i;
4861 
4862 	if (pt != NULL && pt->pt_copyID != copyID)
4863 	{
4864 	    // Didn't see this partial yet.
4865 	    pt->pt_copyID = copyID;
4866 
4867 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4868 
4869 	    if (pt->pt_dict != NULL)
4870 	    {
4871 		typval_T dtv;
4872 
4873 		dtv.v_type = VAR_DICT;
4874 		dtv.vval.v_dict = pt->pt_dict;
4875 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4876 	    }
4877 
4878 	    for (i = 0; i < pt->pt_argc; ++i)
4879 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4880 							ht_stack, list_stack);
4881 	    if (pt->pt_funcstack != NULL)
4882 	    {
4883 		typval_T    *stack = pt->pt_funcstack->fs_ga.ga_data;
4884 
4885 		for (i = 0; i < pt->pt_funcstack->fs_ga.ga_len; ++i)
4886 		    abort = abort || set_ref_in_item(stack + i, copyID,
4887 							 ht_stack, list_stack);
4888 	    }
4889 
4890 	}
4891     }
4892 #ifdef FEAT_JOB_CHANNEL
4893     else if (tv->v_type == VAR_JOB)
4894     {
4895 	job_T	    *job = tv->vval.v_job;
4896 	typval_T    dtv;
4897 
4898 	if (job != NULL && job->jv_copyID != copyID)
4899 	{
4900 	    job->jv_copyID = copyID;
4901 	    if (job->jv_channel != NULL)
4902 	    {
4903 		dtv.v_type = VAR_CHANNEL;
4904 		dtv.vval.v_channel = job->jv_channel;
4905 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4906 	    }
4907 	    if (job->jv_exit_cb.cb_partial != NULL)
4908 	    {
4909 		dtv.v_type = VAR_PARTIAL;
4910 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4911 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4912 	    }
4913 	}
4914     }
4915     else if (tv->v_type == VAR_CHANNEL)
4916     {
4917 	channel_T   *ch =tv->vval.v_channel;
4918 	ch_part_T   part;
4919 	typval_T    dtv;
4920 	jsonq_T	    *jq;
4921 	cbq_T	    *cq;
4922 
4923 	if (ch != NULL && ch->ch_copyID != copyID)
4924 	{
4925 	    ch->ch_copyID = copyID;
4926 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4927 	    {
4928 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4929 							     jq = jq->jq_next)
4930 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4931 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4932 							     cq = cq->cq_next)
4933 		    if (cq->cq_callback.cb_partial != NULL)
4934 		    {
4935 			dtv.v_type = VAR_PARTIAL;
4936 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4937 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4938 		    }
4939 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4940 		{
4941 		    dtv.v_type = VAR_PARTIAL;
4942 		    dtv.vval.v_partial =
4943 				      ch->ch_part[part].ch_callback.cb_partial;
4944 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4945 		}
4946 	    }
4947 	    if (ch->ch_callback.cb_partial != NULL)
4948 	    {
4949 		dtv.v_type = VAR_PARTIAL;
4950 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4951 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4952 	    }
4953 	    if (ch->ch_close_cb.cb_partial != NULL)
4954 	    {
4955 		dtv.v_type = VAR_PARTIAL;
4956 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4957 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4958 	    }
4959 	}
4960     }
4961 #endif
4962     return abort;
4963 }
4964 
4965 /*
4966  * Return a string with the string representation of a variable.
4967  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4968  * "numbuf" is used for a number.
4969  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4970  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4971  * strings as "string()", otherwise does not put quotes around strings, as
4972  * ":echo" displays values.
4973  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4974  * are replaced with "...".
4975  * May return NULL.
4976  */
4977     char_u *
4978 echo_string_core(
4979     typval_T	*tv,
4980     char_u	**tofree,
4981     char_u	*numbuf,
4982     int		copyID,
4983     int		echo_style,
4984     int		restore_copyID,
4985     int		composite_val)
4986 {
4987     static int	recurse = 0;
4988     char_u	*r = NULL;
4989 
4990     if (recurse >= DICT_MAXNEST)
4991     {
4992 	if (!did_echo_string_emsg)
4993 	{
4994 	    // Only give this message once for a recursive call to avoid
4995 	    // flooding the user with errors.  And stop iterating over lists
4996 	    // and dicts.
4997 	    did_echo_string_emsg = TRUE;
4998 	    emsg(_("E724: variable nested too deep for displaying"));
4999 	}
5000 	*tofree = NULL;
5001 	return (char_u *)"{E724}";
5002     }
5003     ++recurse;
5004 
5005     switch (tv->v_type)
5006     {
5007 	case VAR_STRING:
5008 	    if (echo_style && !composite_val)
5009 	    {
5010 		*tofree = NULL;
5011 		r = tv->vval.v_string;
5012 		if (r == NULL)
5013 		    r = (char_u *)"";
5014 	    }
5015 	    else
5016 	    {
5017 		*tofree = string_quote(tv->vval.v_string, FALSE);
5018 		r = *tofree;
5019 	    }
5020 	    break;
5021 
5022 	case VAR_FUNC:
5023 	    if (echo_style)
5024 	    {
5025 		*tofree = NULL;
5026 		r = tv->vval.v_string;
5027 	    }
5028 	    else
5029 	    {
5030 		*tofree = string_quote(tv->vval.v_string, TRUE);
5031 		r = *tofree;
5032 	    }
5033 	    break;
5034 
5035 	case VAR_PARTIAL:
5036 	    {
5037 		partial_T   *pt = tv->vval.v_partial;
5038 		char_u	    *fname = string_quote(pt == NULL ? NULL
5039 						    : partial_name(pt), FALSE);
5040 		garray_T    ga;
5041 		int	    i;
5042 		char_u	    *tf;
5043 
5044 		ga_init2(&ga, 1, 100);
5045 		ga_concat(&ga, (char_u *)"function(");
5046 		if (fname != NULL)
5047 		{
5048 		    ga_concat(&ga, fname);
5049 		    vim_free(fname);
5050 		}
5051 		if (pt != NULL && pt->pt_argc > 0)
5052 		{
5053 		    ga_concat(&ga, (char_u *)", [");
5054 		    for (i = 0; i < pt->pt_argc; ++i)
5055 		    {
5056 			if (i > 0)
5057 			    ga_concat(&ga, (char_u *)", ");
5058 			ga_concat(&ga,
5059 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
5060 			vim_free(tf);
5061 		    }
5062 		    ga_concat(&ga, (char_u *)"]");
5063 		}
5064 		if (pt != NULL && pt->pt_dict != NULL)
5065 		{
5066 		    typval_T dtv;
5067 
5068 		    ga_concat(&ga, (char_u *)", ");
5069 		    dtv.v_type = VAR_DICT;
5070 		    dtv.vval.v_dict = pt->pt_dict;
5071 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
5072 		    vim_free(tf);
5073 		}
5074 		ga_concat(&ga, (char_u *)")");
5075 
5076 		*tofree = ga.ga_data;
5077 		r = *tofree;
5078 		break;
5079 	    }
5080 
5081 	case VAR_BLOB:
5082 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
5083 	    break;
5084 
5085 	case VAR_LIST:
5086 	    if (tv->vval.v_list == NULL)
5087 	    {
5088 		// NULL list is equivalent to empty list.
5089 		*tofree = NULL;
5090 		r = (char_u *)"[]";
5091 	    }
5092 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
5093 		    && tv->vval.v_list->lv_len > 0)
5094 	    {
5095 		*tofree = NULL;
5096 		r = (char_u *)"[...]";
5097 	    }
5098 	    else
5099 	    {
5100 		int old_copyID = tv->vval.v_list->lv_copyID;
5101 
5102 		tv->vval.v_list->lv_copyID = copyID;
5103 		*tofree = list2string(tv, copyID, restore_copyID);
5104 		if (restore_copyID)
5105 		    tv->vval.v_list->lv_copyID = old_copyID;
5106 		r = *tofree;
5107 	    }
5108 	    break;
5109 
5110 	case VAR_DICT:
5111 	    if (tv->vval.v_dict == NULL)
5112 	    {
5113 		// NULL dict is equivalent to empty dict.
5114 		*tofree = NULL;
5115 		r = (char_u *)"{}";
5116 	    }
5117 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
5118 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
5119 	    {
5120 		*tofree = NULL;
5121 		r = (char_u *)"{...}";
5122 	    }
5123 	    else
5124 	    {
5125 		int old_copyID = tv->vval.v_dict->dv_copyID;
5126 
5127 		tv->vval.v_dict->dv_copyID = copyID;
5128 		*tofree = dict2string(tv, copyID, restore_copyID);
5129 		if (restore_copyID)
5130 		    tv->vval.v_dict->dv_copyID = old_copyID;
5131 		r = *tofree;
5132 	    }
5133 	    break;
5134 
5135 	case VAR_NUMBER:
5136 	case VAR_UNKNOWN:
5137 	case VAR_ANY:
5138 	case VAR_VOID:
5139 	    *tofree = NULL;
5140 	    r = tv_get_string_buf(tv, numbuf);
5141 	    break;
5142 
5143 	case VAR_JOB:
5144 	case VAR_CHANNEL:
5145 #ifdef FEAT_JOB_CHANNEL
5146 	    *tofree = NULL;
5147 	    r = tv->v_type == VAR_JOB ? job_to_string_buf(tv, numbuf)
5148 					   : channel_to_string_buf(tv, numbuf);
5149 	    if (composite_val)
5150 	    {
5151 		*tofree = string_quote(r, FALSE);
5152 		r = *tofree;
5153 	    }
5154 #endif
5155 	    break;
5156 
5157 	case VAR_INSTR:
5158 	    *tofree = NULL;
5159 	    r = (char_u *)"instructions";
5160 	    break;
5161 
5162 	case VAR_FLOAT:
5163 #ifdef FEAT_FLOAT
5164 	    *tofree = NULL;
5165 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
5166 	    r = numbuf;
5167 	    break;
5168 #endif
5169 
5170 	case VAR_BOOL:
5171 	case VAR_SPECIAL:
5172 	    *tofree = NULL;
5173 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
5174 	    break;
5175     }
5176 
5177     if (--recurse == 0)
5178 	did_echo_string_emsg = FALSE;
5179     return r;
5180 }
5181 
5182 /*
5183  * Return a string with the string representation of a variable.
5184  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5185  * "numbuf" is used for a number.
5186  * Does not put quotes around strings, as ":echo" displays values.
5187  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5188  * May return NULL.
5189  */
5190     char_u *
5191 echo_string(
5192     typval_T	*tv,
5193     char_u	**tofree,
5194     char_u	*numbuf,
5195     int		copyID)
5196 {
5197     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
5198 }
5199 
5200 /*
5201  * Convert the specified byte index of line 'lnum' in buffer 'buf' to a
5202  * character index.  Works only for loaded buffers. Returns -1 on failure.
5203  * The index of the first byte and the first character is zero.
5204  */
5205     int
5206 buf_byteidx_to_charidx(buf_T *buf, int lnum, int byteidx)
5207 {
5208     char_u	*str;
5209     char_u	*t;
5210     int		count;
5211 
5212     if (buf == NULL || buf->b_ml.ml_mfp == NULL)
5213 	return -1;
5214 
5215     if (lnum > buf->b_ml.ml_line_count)
5216 	lnum = buf->b_ml.ml_line_count;
5217 
5218     str = ml_get_buf(buf, lnum, FALSE);
5219     if (str == NULL)
5220 	return -1;
5221 
5222     if (*str == NUL)
5223 	return 0;
5224 
5225     // count the number of characters
5226     t = str;
5227     for (count = 0; *t != NUL && t <= str + byteidx; count++)
5228 	t += mb_ptr2len(t);
5229 
5230     // In insert mode, when the cursor is at the end of a non-empty line,
5231     // byteidx points to the NUL character immediately past the end of the
5232     // string. In this case, add one to the character count.
5233     if (*t == NUL && byteidx != 0 && t == str + byteidx)
5234 	count++;
5235 
5236     return count - 1;
5237 }
5238 
5239 /*
5240  * Convert the specified character index of line 'lnum' in buffer 'buf' to a
5241  * byte index.  Works only for loaded buffers. Returns -1 on failure.
5242  * The index of the first byte and the first character is zero.
5243  */
5244     int
5245 buf_charidx_to_byteidx(buf_T *buf, int lnum, int charidx)
5246 {
5247     char_u	*str;
5248     char_u	*t;
5249 
5250     if (buf == NULL || buf->b_ml.ml_mfp == NULL)
5251 	return -1;
5252 
5253     if (lnum > buf->b_ml.ml_line_count)
5254 	lnum = buf->b_ml.ml_line_count;
5255 
5256     str = ml_get_buf(buf, lnum, FALSE);
5257     if (str == NULL)
5258 	return -1;
5259 
5260     // Convert the character offset to a byte offset
5261     t = str;
5262     while (*t != NUL && --charidx > 0)
5263 	t += mb_ptr2len(t);
5264 
5265     return t - str;
5266 }
5267 
5268 /*
5269  * Translate a String variable into a position.
5270  * Returns NULL when there is an error.
5271  */
5272     pos_T *
5273 var2fpos(
5274     typval_T	*varp,
5275     int		dollar_lnum,	// TRUE when $ is last line
5276     int		*fnum,		// set to fnum for '0, 'A, etc.
5277     int		charcol)	// return character column
5278 {
5279     char_u		*name;
5280     static pos_T	pos;
5281     pos_T		*pp;
5282 
5283     // Argument can be [lnum, col, coladd].
5284     if (varp->v_type == VAR_LIST)
5285     {
5286 	list_T		*l;
5287 	int		len;
5288 	int		error = FALSE;
5289 	listitem_T	*li;
5290 
5291 	l = varp->vval.v_list;
5292 	if (l == NULL)
5293 	    return NULL;
5294 
5295 	// Get the line number
5296 	pos.lnum = list_find_nr(l, 0L, &error);
5297 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
5298 	    return NULL;	// invalid line number
5299 	if (charcol)
5300 	    len = (long)mb_charlen(ml_get(pos.lnum));
5301 	else
5302 	    len = (long)STRLEN(ml_get(pos.lnum));
5303 
5304 	// Get the column number
5305 	// We accept "$" for the column number: last column.
5306 	li = list_find(l, 1L);
5307 	if (li != NULL && li->li_tv.v_type == VAR_STRING
5308 		&& li->li_tv.vval.v_string != NULL
5309 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
5310 	{
5311 	    pos.col = len + 1;
5312 	}
5313 	else
5314 	{
5315 	    pos.col = list_find_nr(l, 1L, &error);
5316 	    if (error)
5317 		return NULL;
5318 	}
5319 
5320 	// Accept a position up to the NUL after the line.
5321 	if (pos.col == 0 || (int)pos.col > len + 1)
5322 	    return NULL;	// invalid column number
5323 	--pos.col;
5324 
5325 	// Get the virtual offset.  Defaults to zero.
5326 	pos.coladd = list_find_nr(l, 2L, &error);
5327 	if (error)
5328 	    pos.coladd = 0;
5329 
5330 	return &pos;
5331     }
5332 
5333     if (in_vim9script() && check_for_string_arg(varp, 0) == FAIL)
5334 	return NULL;
5335 
5336     name = tv_get_string_chk(varp);
5337     if (name == NULL)
5338 	return NULL;
5339     if (name[0] == '.')				// cursor
5340     {
5341 	pos = curwin->w_cursor;
5342 	if (charcol)
5343 	    pos.col = buf_byteidx_to_charidx(curbuf, pos.lnum, pos.col);
5344 	return &pos;
5345     }
5346     if (name[0] == 'v' && name[1] == NUL)	// Visual start
5347     {
5348 	if (VIsual_active)
5349 	    pos = VIsual;
5350 	else
5351 	    pos = curwin->w_cursor;
5352 	if (charcol)
5353 	    pos.col = buf_byteidx_to_charidx(curbuf, pos.lnum, pos.col);
5354 	return &pos;
5355     }
5356     if (name[0] == '\'')			// mark
5357     {
5358 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
5359 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
5360 	    return NULL;
5361 	if (charcol)
5362 	    pp->col = buf_byteidx_to_charidx(curbuf, pp->lnum, pp->col);
5363 	return pp;
5364     }
5365 
5366     pos.coladd = 0;
5367 
5368     if (name[0] == 'w' && dollar_lnum)
5369     {
5370 	pos.col = 0;
5371 	if (name[1] == '0')		// "w0": first visible line
5372 	{
5373 	    update_topline();
5374 	    // In silent Ex mode topline is zero, but that's not a valid line
5375 	    // number; use one instead.
5376 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
5377 	    return &pos;
5378 	}
5379 	else if (name[1] == '$')	// "w$": last visible line
5380 	{
5381 	    validate_botline();
5382 	    // In silent Ex mode botline is zero, return zero then.
5383 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
5384 	    return &pos;
5385 	}
5386     }
5387     else if (name[0] == '$')		// last column or line
5388     {
5389 	if (dollar_lnum)
5390 	{
5391 	    pos.lnum = curbuf->b_ml.ml_line_count;
5392 	    pos.col = 0;
5393 	}
5394 	else
5395 	{
5396 	    pos.lnum = curwin->w_cursor.lnum;
5397 	    if (charcol)
5398 		pos.col = (colnr_T)mb_charlen(ml_get_curline());
5399 	    else
5400 		pos.col = (colnr_T)STRLEN(ml_get_curline());
5401 	}
5402 	return &pos;
5403     }
5404     if (in_vim9script())
5405 	semsg(_(e_invalid_value_for_line_number_str), name);
5406     return NULL;
5407 }
5408 
5409 /*
5410  * Convert list in "arg" into a position and optional file number.
5411  * When "fnump" is NULL there is no file number, only 3 items.
5412  * Note that the column is passed on as-is, the caller may want to decrement
5413  * it to use 1 for the first column.
5414  * Return FAIL when conversion is not possible, doesn't check the position for
5415  * validity.
5416  */
5417     int
5418 list2fpos(
5419     typval_T	*arg,
5420     pos_T	*posp,
5421     int		*fnump,
5422     colnr_T	*curswantp,
5423     int		charcol)
5424 {
5425     list_T	*l = arg->vval.v_list;
5426     long	i = 0;
5427     long	n;
5428 
5429     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
5430     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
5431     if (arg->v_type != VAR_LIST
5432 	    || l == NULL
5433 	    || l->lv_len < (fnump == NULL ? 2 : 3)
5434 	    || l->lv_len > (fnump == NULL ? 4 : 5))
5435 	return FAIL;
5436 
5437     if (fnump != NULL)
5438     {
5439 	n = list_find_nr(l, i++, NULL);	// fnum
5440 	if (n < 0)
5441 	    return FAIL;
5442 	if (n == 0)
5443 	    n = curbuf->b_fnum;		// current buffer
5444 	*fnump = n;
5445     }
5446 
5447     n = list_find_nr(l, i++, NULL);	// lnum
5448     if (n < 0)
5449 	return FAIL;
5450     posp->lnum = n;
5451 
5452     n = list_find_nr(l, i++, NULL);	// col
5453     if (n < 0)
5454 	return FAIL;
5455     // If character position is specified, then convert to byte position
5456     if (charcol)
5457     {
5458 	buf_T	*buf;
5459 
5460 	// Get the text for the specified line in a loaded buffer
5461 	buf = buflist_findnr(fnump == NULL ? curbuf->b_fnum : *fnump);
5462 	if (buf == NULL || buf->b_ml.ml_mfp == NULL)
5463 	    return FAIL;
5464 
5465 	n = buf_charidx_to_byteidx(buf, posp->lnum, n) + 1;
5466     }
5467     posp->col = n;
5468 
5469     n = list_find_nr(l, i, NULL);	// off
5470     if (n < 0)
5471 	posp->coladd = 0;
5472     else
5473 	posp->coladd = n;
5474 
5475     if (curswantp != NULL)
5476 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
5477 
5478     return OK;
5479 }
5480 
5481 /*
5482  * Get the length of an environment variable name.
5483  * Advance "arg" to the first character after the name.
5484  * Return 0 for error.
5485  */
5486     int
5487 get_env_len(char_u **arg)
5488 {
5489     char_u	*p;
5490     int		len;
5491 
5492     for (p = *arg; vim_isIDc(*p); ++p)
5493 	;
5494     if (p == *arg)	    // no name found
5495 	return 0;
5496 
5497     len = (int)(p - *arg);
5498     *arg = p;
5499     return len;
5500 }
5501 
5502 /*
5503  * Get the length of the name of a function or internal variable.
5504  * "arg" is advanced to after the name.
5505  * Return 0 if something is wrong.
5506  */
5507     int
5508 get_id_len(char_u **arg)
5509 {
5510     char_u	*p;
5511     int		len;
5512 
5513     // Find the end of the name.
5514     for (p = *arg; eval_isnamec(*p); ++p)
5515     {
5516 	if (*p == ':')
5517 	{
5518 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5519 	    // slice "[n:]".  Also "xx:" is not a namespace.
5520 	    len = (int)(p - *arg);
5521 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
5522 		    || len > 1)
5523 		break;
5524 	}
5525     }
5526     if (p == *arg)	    // no name found
5527 	return 0;
5528 
5529     len = (int)(p - *arg);
5530     *arg = p;
5531 
5532     return len;
5533 }
5534 
5535 /*
5536  * Get the length of the name of a variable or function.
5537  * Only the name is recognized, does not handle ".key" or "[idx]".
5538  * "arg" is advanced to the first non-white character after the name.
5539  * Return -1 if curly braces expansion failed.
5540  * Return 0 if something else is wrong.
5541  * If the name contains 'magic' {}'s, expand them and return the
5542  * expanded name in an allocated string via 'alias' - caller must free.
5543  */
5544     int
5545 get_name_len(
5546     char_u	**arg,
5547     char_u	**alias,
5548     int		evaluate,
5549     int		verbose)
5550 {
5551     int		len;
5552     char_u	*p;
5553     char_u	*expr_start;
5554     char_u	*expr_end;
5555 
5556     *alias = NULL;  // default to no alias
5557 
5558     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
5559 						  && (*arg)[2] == (int)KE_SNR)
5560     {
5561 	// hard coded <SNR>, already translated
5562 	*arg += 3;
5563 	return get_id_len(arg) + 3;
5564     }
5565     len = eval_fname_script(*arg);
5566     if (len > 0)
5567     {
5568 	// literal "<SID>", "s:" or "<SNR>"
5569 	*arg += len;
5570     }
5571 
5572     /*
5573      * Find the end of the name; check for {} construction.
5574      */
5575     p = find_name_end(*arg, &expr_start, &expr_end,
5576 					       len > 0 ? 0 : FNE_CHECK_START);
5577     if (expr_start != NULL)
5578     {
5579 	char_u	*temp_string;
5580 
5581 	if (!evaluate)
5582 	{
5583 	    len += (int)(p - *arg);
5584 	    *arg = skipwhite(p);
5585 	    return len;
5586 	}
5587 
5588 	/*
5589 	 * Include any <SID> etc in the expanded string:
5590 	 * Thus the -len here.
5591 	 */
5592 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
5593 	if (temp_string == NULL)
5594 	    return -1;
5595 	*alias = temp_string;
5596 	*arg = skipwhite(p);
5597 	return (int)STRLEN(temp_string);
5598     }
5599 
5600     len += get_id_len(arg);
5601     // Only give an error when there is something, otherwise it will be
5602     // reported at a higher level.
5603     if (len == 0 && verbose && **arg != NUL)
5604 	semsg(_(e_invalid_expression_str), *arg);
5605 
5606     return len;
5607 }
5608 
5609 /*
5610  * Find the end of a variable or function name, taking care of magic braces.
5611  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
5612  * start and end of the first magic braces item.
5613  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
5614  * Return a pointer to just after the name.  Equal to "arg" if there is no
5615  * valid name.
5616  */
5617     char_u *
5618 find_name_end(
5619     char_u	*arg,
5620     char_u	**expr_start,
5621     char_u	**expr_end,
5622     int		flags)
5623 {
5624     int		mb_nest = 0;
5625     int		br_nest = 0;
5626     char_u	*p;
5627     int		len;
5628     int		vim9script = in_vim9script();
5629 
5630     if (expr_start != NULL)
5631     {
5632 	*expr_start = NULL;
5633 	*expr_end = NULL;
5634     }
5635 
5636     // Quick check for valid starting character.
5637     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg)
5638 						&& (*arg != '{' || vim9script))
5639 	return arg;
5640 
5641     for (p = arg; *p != NUL
5642 		    && (eval_isnamec(*p)
5643 			|| (*p == '{' && !vim9script)
5644 			|| ((flags & FNE_INCL_BR) && (*p == '['
5645 					 || (*p == '.' && eval_isdictc(p[1]))))
5646 			|| mb_nest != 0
5647 			|| br_nest != 0); MB_PTR_ADV(p))
5648     {
5649 	if (*p == '\'')
5650 	{
5651 	    // skip over 'string' to avoid counting [ and ] inside it.
5652 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5653 		;
5654 	    if (*p == NUL)
5655 		break;
5656 	}
5657 	else if (*p == '"')
5658 	{
5659 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
5660 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5661 		if (*p == '\\' && p[1] != NUL)
5662 		    ++p;
5663 	    if (*p == NUL)
5664 		break;
5665 	}
5666 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5667 	{
5668 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5669 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
5670 	    len = (int)(p - arg);
5671 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5672 		    || (len > 1 && p[-1] != '}'))
5673 		break;
5674 	}
5675 
5676 	if (mb_nest == 0)
5677 	{
5678 	    if (*p == '[')
5679 		++br_nest;
5680 	    else if (*p == ']')
5681 		--br_nest;
5682 	}
5683 
5684 	if (br_nest == 0 && !vim9script)
5685 	{
5686 	    if (*p == '{')
5687 	    {
5688 		mb_nest++;
5689 		if (expr_start != NULL && *expr_start == NULL)
5690 		    *expr_start = p;
5691 	    }
5692 	    else if (*p == '}')
5693 	    {
5694 		mb_nest--;
5695 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5696 		    *expr_end = p;
5697 	    }
5698 	}
5699     }
5700 
5701     return p;
5702 }
5703 
5704 /*
5705  * Expands out the 'magic' {}'s in a variable/function name.
5706  * Note that this can call itself recursively, to deal with
5707  * constructs like foo{bar}{baz}{bam}
5708  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5709  *			"in_start"      ^
5710  *			"expr_start"	   ^
5711  *			"expr_end"		 ^
5712  *			"in_end"			    ^
5713  *
5714  * Returns a new allocated string, which the caller must free.
5715  * Returns NULL for failure.
5716  */
5717     static char_u *
5718 make_expanded_name(
5719     char_u	*in_start,
5720     char_u	*expr_start,
5721     char_u	*expr_end,
5722     char_u	*in_end)
5723 {
5724     char_u	c1;
5725     char_u	*retval = NULL;
5726     char_u	*temp_result;
5727 
5728     if (expr_end == NULL || in_end == NULL)
5729 	return NULL;
5730     *expr_start	= NUL;
5731     *expr_end = NUL;
5732     c1 = *in_end;
5733     *in_end = NUL;
5734 
5735     temp_result = eval_to_string(expr_start + 1, FALSE);
5736     if (temp_result != NULL)
5737     {
5738 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5739 						   + (in_end - expr_end) + 1);
5740 	if (retval != NULL)
5741 	{
5742 	    STRCPY(retval, in_start);
5743 	    STRCAT(retval, temp_result);
5744 	    STRCAT(retval, expr_end + 1);
5745 	}
5746     }
5747     vim_free(temp_result);
5748 
5749     *in_end = c1;		// put char back for error messages
5750     *expr_start = '{';
5751     *expr_end = '}';
5752 
5753     if (retval != NULL)
5754     {
5755 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5756 	if (expr_start != NULL)
5757 	{
5758 	    // Further expansion!
5759 	    temp_result = make_expanded_name(retval, expr_start,
5760 						       expr_end, temp_result);
5761 	    vim_free(retval);
5762 	    retval = temp_result;
5763 	}
5764     }
5765 
5766     return retval;
5767 }
5768 
5769 /*
5770  * Return TRUE if character "c" can be used in a variable or function name.
5771  * Does not include '{' or '}' for magic braces.
5772  */
5773     int
5774 eval_isnamec(int c)
5775 {
5776     return ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR;
5777 }
5778 
5779 /*
5780  * Return TRUE if character "c" can be used as the first character in a
5781  * variable or function name (excluding '{' and '}').
5782  */
5783     int
5784 eval_isnamec1(int c)
5785 {
5786     return ASCII_ISALPHA(c) || c == '_';
5787 }
5788 
5789 /*
5790  * Return TRUE if character "c" can be used as the first character of a
5791  * dictionary key.
5792  */
5793     int
5794 eval_isdictc(int c)
5795 {
5796     return ASCII_ISALNUM(c) || c == '_';
5797 }
5798 
5799 /*
5800  * Handle:
5801  * - expr[expr], expr[expr:expr] subscript
5802  * - ".name" lookup
5803  * - function call with Funcref variable: func(expr)
5804  * - method call: var->method()
5805  *
5806  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5807  */
5808     int
5809 handle_subscript(
5810     char_u	**arg,
5811     typval_T	*rettv,
5812     evalarg_T	*evalarg,
5813     int		verbose)	// give error messages
5814 {
5815     int		evaluate = evalarg != NULL
5816 				      && (evalarg->eval_flags & EVAL_EVALUATE);
5817     int		ret = OK;
5818     dict_T	*selfdict = NULL;
5819     int		check_white = TRUE;
5820     int		getnext;
5821     char_u	*p;
5822 
5823     while (ret == OK)
5824     {
5825 	// When at the end of the line and ".name" or "->{" or "->X" follows in
5826 	// the next line then consume the line break.
5827 	p = eval_next_non_blank(*arg, evalarg, &getnext);
5828 	if (getnext
5829 	    && ((rettv->v_type == VAR_DICT && *p == '.' && eval_isdictc(p[1]))
5830 		|| (p[0] == '-' && p[1] == '>' && (p[2] == '{'
5831 			|| ASCII_ISALPHA(in_vim9script() ? *skipwhite(p + 2)
5832 								    : p[2])))))
5833 	{
5834 	    *arg = eval_next_line(evalarg);
5835 	    p = *arg;
5836 	    check_white = FALSE;
5837 	}
5838 
5839 	if (rettv->v_type == VAR_ANY)
5840 	{
5841 	    char_u	*exp_name;
5842 	    int		cc;
5843 	    int		idx;
5844 	    ufunc_T	*ufunc;
5845 	    type_T	*type;
5846 
5847 	    // Found script from "import * as {name}", script item name must
5848 	    // follow.
5849 	    if (**arg != '.')
5850 	    {
5851 		if (verbose)
5852 		    semsg(_(e_expected_str_but_got_str), "'.'", *arg);
5853 		ret = FAIL;
5854 		break;
5855 	    }
5856 	    ++*arg;
5857 	    if (IS_WHITE_OR_NUL(**arg))
5858 	    {
5859 		if (verbose)
5860 		    emsg(_(e_no_white_space_allowed_after_dot));
5861 		ret = FAIL;
5862 		break;
5863 	    }
5864 
5865 	    // isolate the name
5866 	    exp_name = *arg;
5867 	    while (eval_isnamec(**arg))
5868 		++*arg;
5869 	    cc = **arg;
5870 	    **arg = NUL;
5871 
5872 	    idx = find_exported(rettv->vval.v_number, exp_name, &ufunc, &type,
5873 						  evalarg->eval_cctx, verbose);
5874 	    **arg = cc;
5875 	    *arg = skipwhite(*arg);
5876 
5877 	    if (idx < 0 && ufunc == NULL)
5878 	    {
5879 		ret = FAIL;
5880 		break;
5881 	    }
5882 	    if (idx >= 0)
5883 	    {
5884 		scriptitem_T    *si = SCRIPT_ITEM(rettv->vval.v_number);
5885 		svar_T		*sv = ((svar_T *)si->sn_var_vals.ga_data) + idx;
5886 
5887 		copy_tv(sv->sv_tv, rettv);
5888 	    }
5889 	    else
5890 	    {
5891 		rettv->v_type = VAR_FUNC;
5892 		rettv->vval.v_string = vim_strsave(ufunc->uf_name);
5893 	    }
5894 	}
5895 
5896 	if ((**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5897 			    || rettv->v_type == VAR_PARTIAL))
5898 		    && (!check_white || !VIM_ISWHITE(*(*arg - 1))))
5899 	{
5900 	    ret = call_func_rettv(arg, evalarg, rettv, evaluate,
5901 							       selfdict, NULL);
5902 
5903 	    // Stop the expression evaluation when immediately aborting on
5904 	    // error, or when an interrupt occurred or an exception was thrown
5905 	    // but not caught.
5906 	    if (aborting())
5907 	    {
5908 		if (ret == OK)
5909 		    clear_tv(rettv);
5910 		ret = FAIL;
5911 	    }
5912 	    dict_unref(selfdict);
5913 	    selfdict = NULL;
5914 	}
5915 	else if (p[0] == '-' && p[1] == '>')
5916 	{
5917 	    if (in_vim9script())
5918 		*arg = skipwhite(p + 2);
5919 	    else
5920 		*arg = p + 2;
5921 	    if (ret == OK)
5922 	    {
5923 		if (VIM_ISWHITE(**arg))
5924 		{
5925 		    emsg(_(e_nowhitespace));
5926 		    ret = FAIL;
5927 		}
5928 		else if ((**arg == '{' && !in_vim9script()) || **arg == '(')
5929 		    // expr->{lambda}() or expr->(lambda)()
5930 		    ret = eval_lambda(arg, rettv, evalarg, verbose);
5931 		else
5932 		    // expr->name()
5933 		    ret = eval_method(arg, rettv, evalarg, verbose);
5934 	    }
5935 	}
5936 	// "." is ".name" lookup when we found a dict or when evaluating and
5937 	// scriptversion is at least 2, where string concatenation is "..".
5938 	else if (**arg == '['
5939 		|| (**arg == '.' && (rettv->v_type == VAR_DICT
5940 			|| (!evaluate
5941 			    && (*arg)[1] != '.'
5942 			    && current_sctx.sc_version >= 2))))
5943 	{
5944 	    dict_unref(selfdict);
5945 	    if (rettv->v_type == VAR_DICT)
5946 	    {
5947 		selfdict = rettv->vval.v_dict;
5948 		if (selfdict != NULL)
5949 		    ++selfdict->dv_refcount;
5950 	    }
5951 	    else
5952 		selfdict = NULL;
5953 	    if (eval_index(arg, rettv, evalarg, verbose) == FAIL)
5954 	    {
5955 		clear_tv(rettv);
5956 		ret = FAIL;
5957 	    }
5958 	}
5959 	else
5960 	    break;
5961     }
5962 
5963     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5964     // Don't do this when "Func" is already a partial that was bound
5965     // explicitly (pt_auto is FALSE).
5966     if (selfdict != NULL
5967 	    && (rettv->v_type == VAR_FUNC
5968 		|| (rettv->v_type == VAR_PARTIAL
5969 		    && (rettv->vval.v_partial->pt_auto
5970 			|| rettv->vval.v_partial->pt_dict == NULL))))
5971 	selfdict = make_partial(selfdict, rettv);
5972 
5973     dict_unref(selfdict);
5974     return ret;
5975 }
5976 
5977 /*
5978  * Make a copy of an item.
5979  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5980  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5981  * reference to an already copied list/dict can be used.
5982  * Returns FAIL or OK.
5983  */
5984     int
5985 item_copy(
5986     typval_T	*from,
5987     typval_T	*to,
5988     int		deep,
5989     int		copyID)
5990 {
5991     static int	recurse = 0;
5992     int		ret = OK;
5993 
5994     if (recurse >= DICT_MAXNEST)
5995     {
5996 	emsg(_("E698: variable nested too deep for making a copy"));
5997 	return FAIL;
5998     }
5999     ++recurse;
6000 
6001     switch (from->v_type)
6002     {
6003 	case VAR_NUMBER:
6004 	case VAR_FLOAT:
6005 	case VAR_STRING:
6006 	case VAR_FUNC:
6007 	case VAR_PARTIAL:
6008 	case VAR_BOOL:
6009 	case VAR_SPECIAL:
6010 	case VAR_JOB:
6011 	case VAR_CHANNEL:
6012 	case VAR_INSTR:
6013 	    copy_tv(from, to);
6014 	    break;
6015 	case VAR_LIST:
6016 	    to->v_type = VAR_LIST;
6017 	    to->v_lock = 0;
6018 	    if (from->vval.v_list == NULL)
6019 		to->vval.v_list = NULL;
6020 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
6021 	    {
6022 		// use the copy made earlier
6023 		to->vval.v_list = from->vval.v_list->lv_copylist;
6024 		++to->vval.v_list->lv_refcount;
6025 	    }
6026 	    else
6027 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
6028 	    if (to->vval.v_list == NULL)
6029 		ret = FAIL;
6030 	    break;
6031 	case VAR_BLOB:
6032 	    ret = blob_copy(from->vval.v_blob, to);
6033 	    break;
6034 	case VAR_DICT:
6035 	    to->v_type = VAR_DICT;
6036 	    to->v_lock = 0;
6037 	    if (from->vval.v_dict == NULL)
6038 		to->vval.v_dict = NULL;
6039 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
6040 	    {
6041 		// use the copy made earlier
6042 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
6043 		++to->vval.v_dict->dv_refcount;
6044 	    }
6045 	    else
6046 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
6047 	    if (to->vval.v_dict == NULL)
6048 		ret = FAIL;
6049 	    break;
6050 	case VAR_UNKNOWN:
6051 	case VAR_ANY:
6052 	case VAR_VOID:
6053 	    internal_error_no_abort("item_copy(UNKNOWN)");
6054 	    ret = FAIL;
6055     }
6056     --recurse;
6057     return ret;
6058 }
6059 
6060     void
6061 echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr)
6062 {
6063     char_u	*tofree;
6064     char_u	numbuf[NUMBUFLEN];
6065     char_u	*p = echo_string(rettv, &tofree, numbuf, get_copyID());
6066 
6067     if (*atstart)
6068     {
6069 	*atstart = FALSE;
6070 	// Call msg_start() after eval1(), evaluating the expression
6071 	// may cause a message to appear.
6072 	if (with_space)
6073 	{
6074 	    // Mark the saved text as finishing the line, so that what
6075 	    // follows is displayed on a new line when scrolling back
6076 	    // at the more prompt.
6077 	    msg_sb_eol();
6078 	    msg_start();
6079 	}
6080     }
6081     else if (with_space)
6082 	msg_puts_attr(" ", echo_attr);
6083 
6084     if (p != NULL)
6085 	for ( ; *p != NUL && !got_int; ++p)
6086 	{
6087 	    if (*p == '\n' || *p == '\r' || *p == TAB)
6088 	    {
6089 		if (*p != TAB && *needclr)
6090 		{
6091 		    // remove any text still there from the command
6092 		    msg_clr_eos();
6093 		    *needclr = FALSE;
6094 		}
6095 		msg_putchar_attr(*p, echo_attr);
6096 	    }
6097 	    else
6098 	    {
6099 		if (has_mbyte)
6100 		{
6101 		    int i = (*mb_ptr2len)(p);
6102 
6103 		    (void)msg_outtrans_len_attr(p, i, echo_attr);
6104 		    p += i - 1;
6105 		}
6106 		else
6107 		    (void)msg_outtrans_len_attr(p, 1, echo_attr);
6108 	    }
6109 	}
6110     vim_free(tofree);
6111 }
6112 
6113 /*
6114  * ":echo expr1 ..."	print each argument separated with a space, add a
6115  *			newline at the end.
6116  * ":echon expr1 ..."	print each argument plain.
6117  */
6118     void
6119 ex_echo(exarg_T *eap)
6120 {
6121     char_u	*arg = eap->arg;
6122     typval_T	rettv;
6123     char_u	*arg_start;
6124     int		needclr = TRUE;
6125     int		atstart = TRUE;
6126     int		did_emsg_before = did_emsg;
6127     int		called_emsg_before = called_emsg;
6128     evalarg_T	evalarg;
6129 
6130     fill_evalarg_from_eap(&evalarg, eap, eap->skip);
6131 
6132     if (eap->skip)
6133 	++emsg_skip;
6134     while ((!ends_excmd2(eap->cmd, arg) || *arg == '"') && !got_int)
6135     {
6136 	// If eval1() causes an error message the text from the command may
6137 	// still need to be cleared. E.g., "echo 22,44".
6138 	need_clr_eos = needclr;
6139 
6140 	arg_start = arg;
6141 	if (eval1(&arg, &rettv, &evalarg) == FAIL)
6142 	{
6143 	    /*
6144 	     * Report the invalid expression unless the expression evaluation
6145 	     * has been cancelled due to an aborting error, an interrupt, or an
6146 	     * exception.
6147 	     */
6148 	    if (!aborting() && did_emsg == did_emsg_before
6149 					  && called_emsg == called_emsg_before)
6150 		semsg(_(e_invalid_expression_str), arg_start);
6151 	    need_clr_eos = FALSE;
6152 	    break;
6153 	}
6154 	need_clr_eos = FALSE;
6155 
6156 	if (!eap->skip)
6157 	{
6158 	    if (rettv.v_type == VAR_VOID)
6159 	    {
6160 		semsg(_(e_expression_does_not_result_in_value_str), arg_start);
6161 		break;
6162 	    }
6163 	    echo_one(&rettv, eap->cmdidx == CMD_echo, &atstart, &needclr);
6164 	}
6165 
6166 	clear_tv(&rettv);
6167 	arg = skipwhite(arg);
6168     }
6169     eap->nextcmd = check_nextcmd(arg);
6170     clear_evalarg(&evalarg, eap);
6171 
6172     if (eap->skip)
6173 	--emsg_skip;
6174     else
6175     {
6176 	// remove text that may still be there from the command
6177 	if (needclr)
6178 	    msg_clr_eos();
6179 	if (eap->cmdidx == CMD_echo)
6180 	    msg_end();
6181     }
6182 }
6183 
6184 /*
6185  * ":echohl {name}".
6186  */
6187     void
6188 ex_echohl(exarg_T *eap)
6189 {
6190     echo_attr = syn_name2attr(eap->arg);
6191 }
6192 
6193 /*
6194  * Returns the :echo attribute
6195  */
6196     int
6197 get_echo_attr(void)
6198 {
6199     return echo_attr;
6200 }
6201 
6202 /*
6203  * ":execute expr1 ..."	execute the result of an expression.
6204  * ":echomsg expr1 ..."	Print a message
6205  * ":echoerr expr1 ..."	Print an error
6206  * ":echoconsole expr1 ..." Print a message on stdout
6207  * Each gets spaces around each argument and a newline at the end for
6208  * echo commands
6209  */
6210     void
6211 ex_execute(exarg_T *eap)
6212 {
6213     char_u	*arg = eap->arg;
6214     typval_T	rettv;
6215     int		ret = OK;
6216     char_u	*p;
6217     garray_T	ga;
6218     int		len;
6219     long	start_lnum = SOURCING_LNUM;
6220 
6221     ga_init2(&ga, 1, 80);
6222 
6223     if (eap->skip)
6224 	++emsg_skip;
6225     while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
6226     {
6227 	ret = eval1_emsg(&arg, &rettv, eap);
6228 	if (ret == FAIL)
6229 	    break;
6230 
6231 	if (!eap->skip)
6232 	{
6233 	    char_u   buf[NUMBUFLEN];
6234 
6235 	    if (eap->cmdidx == CMD_execute)
6236 	    {
6237 		if (rettv.v_type == VAR_CHANNEL || rettv.v_type == VAR_JOB)
6238 		{
6239 		    semsg(_(e_using_invalid_value_as_string_str),
6240 						  vartype_name(rettv.v_type));
6241 		    p = NULL;
6242 		}
6243 		else
6244 		    p = tv_get_string_buf(&rettv, buf);
6245 	    }
6246 	    else
6247 		p = tv_stringify(&rettv, buf);
6248 	    if (p == NULL)
6249 	    {
6250 		clear_tv(&rettv);
6251 		ret = FAIL;
6252 		break;
6253 	    }
6254 	    len = (int)STRLEN(p);
6255 	    if (ga_grow(&ga, len + 2) == FAIL)
6256 	    {
6257 		clear_tv(&rettv);
6258 		ret = FAIL;
6259 		break;
6260 	    }
6261 	    if (ga.ga_len)
6262 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
6263 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
6264 	    ga.ga_len += len;
6265 	}
6266 
6267 	clear_tv(&rettv);
6268 	arg = skipwhite(arg);
6269     }
6270 
6271     if (ret != FAIL && ga.ga_data != NULL)
6272     {
6273 	// use the first line of continuation lines for messages
6274 	SOURCING_LNUM = start_lnum;
6275 
6276 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
6277 	{
6278 	    // Mark the already saved text as finishing the line, so that what
6279 	    // follows is displayed on a new line when scrolling back at the
6280 	    // more prompt.
6281 	    msg_sb_eol();
6282 	}
6283 
6284 	if (eap->cmdidx == CMD_echomsg)
6285 	{
6286 	    msg_attr(ga.ga_data, echo_attr);
6287 	    out_flush();
6288 	}
6289 	else if (eap->cmdidx == CMD_echoconsole)
6290 	{
6291 	    ui_write(ga.ga_data, (int)STRLEN(ga.ga_data), TRUE);
6292 	    ui_write((char_u *)"\r\n", 2, TRUE);
6293 	}
6294 	else if (eap->cmdidx == CMD_echoerr)
6295 	{
6296 	    int		save_did_emsg = did_emsg;
6297 
6298 	    // We don't want to abort following commands, restore did_emsg.
6299 	    emsg(ga.ga_data);
6300 	    if (!force_abort)
6301 		did_emsg = save_did_emsg;
6302 	}
6303 	else if (eap->cmdidx == CMD_execute)
6304 	    do_cmdline((char_u *)ga.ga_data,
6305 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
6306     }
6307 
6308     ga_clear(&ga);
6309 
6310     if (eap->skip)
6311 	--emsg_skip;
6312 
6313     eap->nextcmd = check_nextcmd(arg);
6314 }
6315 
6316 /*
6317  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
6318  * "arg" points to the "&" or '+' when called, to "option" when returning.
6319  * Returns NULL when no option name found.  Otherwise pointer to the char
6320  * after the option name.
6321  */
6322     char_u *
6323 find_option_end(char_u **arg, int *opt_flags)
6324 {
6325     char_u	*p = *arg;
6326 
6327     ++p;
6328     if (*p == 'g' && p[1] == ':')
6329     {
6330 	*opt_flags = OPT_GLOBAL;
6331 	p += 2;
6332     }
6333     else if (*p == 'l' && p[1] == ':')
6334     {
6335 	*opt_flags = OPT_LOCAL;
6336 	p += 2;
6337     }
6338     else
6339 	*opt_flags = 0;
6340 
6341     if (!ASCII_ISALPHA(*p))
6342 	return NULL;
6343     *arg = p;
6344 
6345     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
6346 	p += 4;	    // termcap option
6347     else
6348 	while (ASCII_ISALPHA(*p))
6349 	    ++p;
6350     return p;
6351 }
6352 
6353 /*
6354  * Display script name where an item was last set.
6355  * Should only be invoked when 'verbose' is non-zero.
6356  */
6357     void
6358 last_set_msg(sctx_T script_ctx)
6359 {
6360     char_u *p;
6361 
6362     if (script_ctx.sc_sid != 0)
6363     {
6364 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
6365 	if (p != NULL)
6366 	{
6367 	    verbose_enter();
6368 	    msg_puts(_("\n\tLast set from "));
6369 	    msg_puts((char *)p);
6370 	    if (script_ctx.sc_lnum > 0)
6371 	    {
6372 		msg_puts(_(line_msg));
6373 		msg_outnum((long)script_ctx.sc_lnum);
6374 	    }
6375 	    verbose_leave();
6376 	    vim_free(p);
6377 	}
6378     }
6379 }
6380 
6381 #endif // FEAT_EVAL
6382 
6383 /*
6384  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
6385  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
6386  * "flags" can be "g" to do a global substitute.
6387  * Returns an allocated string, NULL for error.
6388  */
6389     char_u *
6390 do_string_sub(
6391     char_u	*str,
6392     char_u	*pat,
6393     char_u	*sub,
6394     typval_T	*expr,
6395     char_u	*flags)
6396 {
6397     int		sublen;
6398     regmatch_T	regmatch;
6399     int		i;
6400     int		do_all;
6401     char_u	*tail;
6402     char_u	*end;
6403     garray_T	ga;
6404     char_u	*ret;
6405     char_u	*save_cpo;
6406     char_u	*zero_width = NULL;
6407 
6408     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
6409     save_cpo = p_cpo;
6410     p_cpo = empty_option;
6411 
6412     ga_init2(&ga, 1, 200);
6413 
6414     do_all = (flags[0] == 'g');
6415 
6416     regmatch.rm_ic = p_ic;
6417     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
6418     if (regmatch.regprog != NULL)
6419     {
6420 	tail = str;
6421 	end = str + STRLEN(str);
6422 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
6423 	{
6424 	    // Skip empty match except for first match.
6425 	    if (regmatch.startp[0] == regmatch.endp[0])
6426 	    {
6427 		if (zero_width == regmatch.startp[0])
6428 		{
6429 		    // avoid getting stuck on a match with an empty string
6430 		    i = mb_ptr2len(tail);
6431 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
6432 								   (size_t)i);
6433 		    ga.ga_len += i;
6434 		    tail += i;
6435 		    continue;
6436 		}
6437 		zero_width = regmatch.startp[0];
6438 	    }
6439 
6440 	    /*
6441 	     * Get some space for a temporary buffer to do the substitution
6442 	     * into.  It will contain:
6443 	     * - The text up to where the match is.
6444 	     * - The substituted text.
6445 	     * - The text after the match.
6446 	     */
6447 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
6448 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
6449 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
6450 	    {
6451 		ga_clear(&ga);
6452 		break;
6453 	    }
6454 
6455 	    // copy the text up to where the match is
6456 	    i = (int)(regmatch.startp[0] - tail);
6457 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
6458 	    // add the substituted text
6459 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
6460 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
6461 	    ga.ga_len += i + sublen - 1;
6462 	    tail = regmatch.endp[0];
6463 	    if (*tail == NUL)
6464 		break;
6465 	    if (!do_all)
6466 		break;
6467 	}
6468 
6469 	if (ga.ga_data != NULL)
6470 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
6471 
6472 	vim_regfree(regmatch.regprog);
6473     }
6474 
6475     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
6476     ga_clear(&ga);
6477     if (p_cpo == empty_option)
6478 	p_cpo = save_cpo;
6479     else
6480     {
6481 	// Darn, evaluating {sub} expression or {expr} changed the value.
6482 	// If it's still empty it was changed and restored, need to restore in
6483 	// the complicated way.
6484 	if (*p_cpo == NUL)
6485 	    set_option_value((char_u *)"cpo", 0L, save_cpo, 0);
6486 	free_string_option(save_cpo);
6487     }
6488 
6489     return ret;
6490 }
6491