xref: /vim-8.2.3635/src/eval.c (revision d2ea7cf1)
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 
61 /*
62  * Return "n1" divided by "n2", taking care of dividing by zero.
63  * If "failed" is not NULL set it to TRUE when dividing by zero fails.
64  */
65 	varnumber_T
66 num_divide(varnumber_T n1, varnumber_T n2, int *failed)
67 {
68     varnumber_T	result;
69 
70     if (n2 == 0)
71     {
72 	if (in_vim9script())
73 	{
74 	    emsg(_(e_divide_by_zero));
75 	    if (failed != NULL)
76 		*failed = TRUE;
77 	}
78 	if (n1 == 0)
79 	    result = VARNUM_MIN; // similar to NaN
80 	else if (n1 < 0)
81 	    result = -VARNUM_MAX;
82 	else
83 	    result = VARNUM_MAX;
84     }
85     else
86 	result = n1 / n2;
87 
88     return result;
89 }
90 
91 /*
92  * Return "n1" modulus "n2", taking care of dividing by zero.
93  * If "failed" is not NULL set it to TRUE when dividing by zero fails.
94  */
95 	varnumber_T
96 num_modulus(varnumber_T n1, varnumber_T n2, int *failed)
97 {
98     if (n2 == 0 && in_vim9script())
99     {
100 	emsg(_(e_divide_by_zero));
101 	if (failed != NULL)
102 	    *failed = TRUE;
103     }
104     return (n2 == 0) ? 0 : (n1 % n2);
105 }
106 
107 #if defined(EBCDIC) || defined(PROTO)
108 /*
109  * Compare struct fst by function name.
110  */
111     static int
112 compare_func_name(const void *s1, const void *s2)
113 {
114     struct fst *p1 = (struct fst *)s1;
115     struct fst *p2 = (struct fst *)s2;
116 
117     return STRCMP(p1->f_name, p2->f_name);
118 }
119 
120 /*
121  * Sort the function table by function name.
122  * The sorting of the table above is ASCII dependent.
123  * On machines using EBCDIC we have to sort it.
124  */
125     static void
126 sortFunctions(void)
127 {
128     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
129 
130     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
131 }
132 #endif
133 
134 /*
135  * Initialize the global and v: variables.
136  */
137     void
138 eval_init(void)
139 {
140     evalvars_init();
141     func_init();
142 
143 #ifdef EBCDIC
144     /*
145      * Sort the function table, to enable binary search.
146      */
147     sortFunctions();
148 #endif
149 }
150 
151 #if defined(EXITFREE) || defined(PROTO)
152     void
153 eval_clear(void)
154 {
155     evalvars_clear();
156     free_scriptnames();  // must come after evalvars_clear().
157     free_locales();
158 
159     // autoloaded script names
160     free_autoload_scriptnames();
161 
162     // unreferenced lists and dicts
163     (void)garbage_collect(FALSE);
164 
165     // functions not garbage collected
166     free_all_functions();
167 }
168 #endif
169 
170     void
171 fill_evalarg_from_eap(evalarg_T *evalarg, exarg_T *eap, int skip)
172 {
173     CLEAR_FIELD(*evalarg);
174     evalarg->eval_flags = skip ? 0 : EVAL_EVALUATE;
175     if (eap != NULL && getline_equal(eap->getline, eap->cookie, getsourceline))
176     {
177 	evalarg->eval_getline = eap->getline;
178 	evalarg->eval_cookie = eap->cookie;
179     }
180 }
181 
182 /*
183  * Top level evaluation function, returning a boolean.
184  * Sets "error" to TRUE if there was an error.
185  * Return TRUE or FALSE.
186  */
187     int
188 eval_to_bool(
189     char_u	*arg,
190     int		*error,
191     exarg_T	*eap,
192     int		skip)	    // only parse, don't execute
193 {
194     typval_T	tv;
195     varnumber_T	retval = FALSE;
196     evalarg_T	evalarg;
197 
198     fill_evalarg_from_eap(&evalarg, eap, skip);
199 
200     if (skip)
201 	++emsg_skip;
202     if (eval0(arg, &tv, eap, &evalarg) == FAIL)
203 	*error = TRUE;
204     else
205     {
206 	*error = FALSE;
207 	if (!skip)
208 	{
209 	    if (in_vim9script())
210 		retval = tv_get_bool_chk(&tv, error);
211 	    else
212 		retval = (tv_get_number_chk(&tv, error) != 0);
213 	    clear_tv(&tv);
214 	}
215     }
216     if (skip)
217 	--emsg_skip;
218     clear_evalarg(&evalarg, eap);
219 
220     return (int)retval;
221 }
222 
223 /*
224  * Call eval1() and give an error message if not done at a lower level.
225  */
226     static int
227 eval1_emsg(char_u **arg, typval_T *rettv, exarg_T *eap)
228 {
229     char_u	*start = *arg;
230     int		ret;
231     int		did_emsg_before = did_emsg;
232     int		called_emsg_before = called_emsg;
233     evalarg_T	evalarg;
234 
235     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
236 
237     ret = eval1(arg, rettv, &evalarg);
238     if (ret == FAIL)
239     {
240 	// Report the invalid expression unless the expression evaluation has
241 	// been cancelled due to an aborting error, an interrupt, or an
242 	// exception, or we already gave a more specific error.
243 	// Also check called_emsg for when using assert_fails().
244 	if (!aborting() && did_emsg == did_emsg_before
245 					  && called_emsg == called_emsg_before)
246 	    semsg(_(e_invexpr2), start);
247     }
248     clear_evalarg(&evalarg, eap);
249     return ret;
250 }
251 
252 /*
253  * Return whether a typval is a valid expression to pass to eval_expr_typval()
254  * or eval_expr_to_bool().  An empty string returns FALSE;
255  */
256     int
257 eval_expr_valid_arg(typval_T *tv)
258 {
259     return tv->v_type != VAR_UNKNOWN
260 	    && (tv->v_type != VAR_STRING
261 		  || (tv->vval.v_string != NULL && *tv->vval.v_string != NUL));
262 }
263 
264 /*
265  * Evaluate an expression, which can be a function, partial or string.
266  * Pass arguments "argv[argc]".
267  * Return the result in "rettv" and OK or FAIL.
268  */
269     int
270 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
271 {
272     char_u	*s;
273     char_u	buf[NUMBUFLEN];
274     funcexe_T	funcexe;
275 
276     if (expr->v_type == VAR_FUNC)
277     {
278 	s = expr->vval.v_string;
279 	if (s == NULL || *s == NUL)
280 	    return FAIL;
281 	CLEAR_FIELD(funcexe);
282 	funcexe.evaluate = TRUE;
283 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
284 	    return FAIL;
285     }
286     else if (expr->v_type == VAR_PARTIAL)
287     {
288 	partial_T   *partial = expr->vval.v_partial;
289 
290 	if (partial == NULL)
291 	    return FAIL;
292 
293 	if (partial->pt_func != NULL
294 			  && partial->pt_func->uf_def_status != UF_NOT_COMPILED)
295 	{
296 	    if (call_def_function(partial->pt_func, argc, argv,
297 						       partial, rettv) == FAIL)
298 		return FAIL;
299 	}
300 	else
301 	{
302 	    s = partial_name(partial);
303 	    if (s == NULL || *s == NUL)
304 		return FAIL;
305 	    CLEAR_FIELD(funcexe);
306 	    funcexe.evaluate = TRUE;
307 	    funcexe.partial = partial;
308 	    if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
309 		return FAIL;
310 	}
311     }
312     else if (expr->v_type == VAR_INSTR)
313     {
314 	return exe_typval_instr(expr, rettv);
315     }
316     else
317     {
318 	s = tv_get_string_buf_chk(expr, buf);
319 	if (s == NULL)
320 	    return FAIL;
321 	s = skipwhite(s);
322 	if (eval1_emsg(&s, rettv, NULL) == FAIL)
323 	    return FAIL;
324 	if (*skipwhite(s) != NUL)  // check for trailing chars after expr
325 	{
326 	    clear_tv(rettv);
327 	    semsg(_(e_invexpr2), s);
328 	    return FAIL;
329 	}
330     }
331     return OK;
332 }
333 
334 /*
335  * Like eval_to_bool() but using a typval_T instead of a string.
336  * Works for string, funcref and partial.
337  */
338     int
339 eval_expr_to_bool(typval_T *expr, int *error)
340 {
341     typval_T	rettv;
342     int		res;
343 
344     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
345     {
346 	*error = TRUE;
347 	return FALSE;
348     }
349     res = (tv_get_bool_chk(&rettv, error) != 0);
350     clear_tv(&rettv);
351     return res;
352 }
353 
354 /*
355  * Top level evaluation function, returning a string.  If "skip" is TRUE,
356  * only parsing to "nextcmd" is done, without reporting errors.  Return
357  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
358  */
359     char_u *
360 eval_to_string_skip(
361     char_u	*arg,
362     exarg_T	*eap,
363     int		skip)	    // only parse, don't execute
364 {
365     typval_T	tv;
366     char_u	*retval;
367     evalarg_T	evalarg;
368 
369     fill_evalarg_from_eap(&evalarg, eap, skip);
370     if (skip)
371 	++emsg_skip;
372     if (eval0(arg, &tv, eap, &evalarg) == FAIL || skip)
373 	retval = NULL;
374     else
375     {
376 	retval = vim_strsave(tv_get_string(&tv));
377 	clear_tv(&tv);
378     }
379     if (skip)
380 	--emsg_skip;
381     clear_evalarg(&evalarg, eap);
382 
383     return retval;
384 }
385 
386 /*
387  * Skip over an expression at "*pp".
388  * Return FAIL for an error, OK otherwise.
389  */
390     int
391 skip_expr(char_u **pp, evalarg_T *evalarg)
392 {
393     typval_T	rettv;
394 
395     *pp = skipwhite(*pp);
396     return eval1(pp, &rettv, evalarg);
397 }
398 
399 /*
400  * Skip over an expression at "*arg".
401  * If in Vim9 script and line breaks are encountered, the lines are
402  * concatenated.  "evalarg->eval_tofree" will be set accordingly.
403  * "arg" is advanced to just after the expression.
404  * "start" is set to the start of the expression, "end" to just after the end.
405  * Also when the expression is copied to allocated memory.
406  * Return FAIL for an error, OK otherwise.
407  */
408     int
409 skip_expr_concatenate(
410 	char_u	    **arg,
411 	char_u	    **start,
412 	char_u	    **end,
413 	evalarg_T   *evalarg)
414 {
415     typval_T	rettv;
416     int		res;
417     int		vim9script = in_vim9script();
418     garray_T    *gap = evalarg == NULL ? NULL : &evalarg->eval_ga;
419     garray_T    *freegap = evalarg == NULL ? NULL : &evalarg->eval_freega;
420     int		save_flags = evalarg == NULL ? 0 : evalarg->eval_flags;
421     int		evaluate = evalarg == NULL
422 			       ? FALSE : (evalarg->eval_flags & EVAL_EVALUATE);
423 
424     if (vim9script && evaluate
425 	       && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
426     {
427 	ga_init2(gap, sizeof(char_u *), 10);
428 	// leave room for "start"
429 	if (ga_grow(gap, 1) == OK)
430 	    ++gap->ga_len;
431 	ga_init2(freegap, sizeof(char_u *), 10);
432     }
433     *start = *arg;
434 
435     // Don't evaluate the expression.
436     if (evalarg != NULL)
437 	evalarg->eval_flags &= ~EVAL_EVALUATE;
438     *arg = skipwhite(*arg);
439     res = eval1(arg, &rettv, evalarg);
440     *end = *arg;
441     if (evalarg != NULL)
442 	evalarg->eval_flags = save_flags;
443 
444     if (vim9script && evaluate
445 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
446     {
447 	if (evalarg->eval_ga.ga_len == 1)
448 	{
449 	    // just the one line, no need to concatenate
450 	    ga_clear(gap);
451 	    gap->ga_itemsize = 0;
452 	}
453 	else
454 	{
455 	    char_u	    *p;
456 	    size_t	    endoff = STRLEN(*arg);
457 
458 	    // Line breaks encountered, concatenate all the lines.
459 	    *((char_u **)gap->ga_data) = *start;
460 	    p = ga_concat_strings(gap, " ");
461 
462 	    // free the lines only when using getsourceline()
463 	    if (evalarg->eval_cookie != NULL)
464 	    {
465 		// Do not free the first line, the caller can still use it.
466 		*((char_u **)gap->ga_data) = NULL;
467 		// Do not free the last line, "arg" points into it, free it
468 		// later.
469 		vim_free(evalarg->eval_tofree);
470 		evalarg->eval_tofree =
471 				    ((char_u **)gap->ga_data)[gap->ga_len - 1];
472 		((char_u **)gap->ga_data)[gap->ga_len - 1] = NULL;
473 		ga_clear_strings(gap);
474 	    }
475 	    else
476 	    {
477 		ga_clear(gap);
478 
479 		// free lines that were explicitly marked for freeing
480 		ga_clear_strings(freegap);
481 	    }
482 
483 	    gap->ga_itemsize = 0;
484 	    if (p == NULL)
485 		return FAIL;
486 	    *start = p;
487 	    vim_free(evalarg->eval_tofree_lambda);
488 	    evalarg->eval_tofree_lambda = p;
489 	    // Compute "end" relative to the end.
490 	    *end = *start + STRLEN(*start) - endoff;
491 	}
492     }
493 
494     return res;
495 }
496 
497 /*
498  * Convert "tv" to a string.
499  * When "convert" is TRUE convert a List into a sequence of lines and convert
500  * a Float to a String.
501  * Returns an allocated string (NULL when out of memory).
502  */
503     char_u *
504 typval2string(typval_T *tv, int convert)
505 {
506     garray_T	ga;
507     char_u	*retval;
508 #ifdef FEAT_FLOAT
509     char_u	numbuf[NUMBUFLEN];
510 #endif
511 
512     if (convert && tv->v_type == VAR_LIST)
513     {
514 	ga_init2(&ga, (int)sizeof(char), 80);
515 	if (tv->vval.v_list != NULL)
516 	{
517 	    list_join(&ga, tv->vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
518 	    if (tv->vval.v_list->lv_len > 0)
519 		ga_append(&ga, NL);
520 	}
521 	ga_append(&ga, NUL);
522 	retval = (char_u *)ga.ga_data;
523     }
524 #ifdef FEAT_FLOAT
525     else if (convert && tv->v_type == VAR_FLOAT)
526     {
527 	vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
528 	retval = vim_strsave(numbuf);
529     }
530 #endif
531     else
532 	retval = vim_strsave(tv_get_string(tv));
533     return retval;
534 }
535 
536 /*
537  * Top level evaluation function, returning a string.  Does not handle line
538  * breaks.
539  * When "convert" is TRUE convert a List into a sequence of lines and convert
540  * a Float to a String.
541  * Return pointer to allocated memory, or NULL for failure.
542  */
543     char_u *
544 eval_to_string_eap(
545     char_u	*arg,
546     int		convert,
547     exarg_T	*eap)
548 {
549     typval_T	tv;
550     char_u	*retval;
551     evalarg_T	evalarg;
552 
553     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
554     if (eval0(arg, &tv, NULL, &evalarg) == FAIL)
555 	retval = NULL;
556     else
557     {
558 	retval = typval2string(&tv, convert);
559 	clear_tv(&tv);
560     }
561     clear_evalarg(&evalarg, NULL);
562 
563     return retval;
564 }
565 
566     char_u *
567 eval_to_string(
568     char_u	*arg,
569     int		convert)
570 {
571     return eval_to_string_eap(arg, convert, NULL);
572 }
573 
574 /*
575  * Call eval_to_string() without using current local variables and using
576  * textwinlock.  When "use_sandbox" is TRUE use the sandbox.
577  * Use legacy Vim script syntax.
578  */
579     char_u *
580 eval_to_string_safe(
581     char_u	*arg,
582     int		use_sandbox)
583 {
584     char_u	*retval;
585     funccal_entry_T funccal_entry;
586     int		save_sc_version = current_sctx.sc_version;
587 
588     current_sctx.sc_version = 1;
589     save_funccal(&funccal_entry);
590     if (use_sandbox)
591 	++sandbox;
592     ++textwinlock;
593     retval = eval_to_string(arg, FALSE);
594     if (use_sandbox)
595 	--sandbox;
596     --textwinlock;
597     restore_funccal();
598     current_sctx.sc_version = save_sc_version;
599     return retval;
600 }
601 
602 /*
603  * Top level evaluation function, returning a number.
604  * Evaluates "expr" silently.
605  * Returns -1 for an error.
606  */
607     varnumber_T
608 eval_to_number(char_u *expr)
609 {
610     typval_T	rettv;
611     varnumber_T	retval;
612     char_u	*p = skipwhite(expr);
613 
614     ++emsg_off;
615 
616     if (eval1(&p, &rettv, &EVALARG_EVALUATE) == FAIL)
617 	retval = -1;
618     else
619     {
620 	retval = tv_get_number_chk(&rettv, NULL);
621 	clear_tv(&rettv);
622     }
623     --emsg_off;
624 
625     return retval;
626 }
627 
628 /*
629  * Top level evaluation function.
630  * Returns an allocated typval_T with the result.
631  * Returns NULL when there is an error.
632  */
633     typval_T *
634 eval_expr(char_u *arg, exarg_T *eap)
635 {
636     typval_T	*tv;
637     evalarg_T	evalarg;
638 
639     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
640 
641     tv = ALLOC_ONE(typval_T);
642     if (tv != NULL && eval0(arg, tv, eap, &evalarg) == FAIL)
643 	VIM_CLEAR(tv);
644 
645     clear_evalarg(&evalarg, eap);
646     return tv;
647 }
648 
649 /*
650  * Call some Vim script function and return the result in "*rettv".
651  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
652  * should have type VAR_UNKNOWN.
653  * Returns OK or FAIL.
654  */
655     int
656 call_vim_function(
657     char_u      *func,
658     int		argc,
659     typval_T	*argv,
660     typval_T	*rettv)
661 {
662     int		ret;
663     funcexe_T	funcexe;
664 
665     rettv->v_type = VAR_UNKNOWN;		// clear_tv() uses this
666     CLEAR_FIELD(funcexe);
667     funcexe.firstline = curwin->w_cursor.lnum;
668     funcexe.lastline = curwin->w_cursor.lnum;
669     funcexe.evaluate = TRUE;
670     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
671     if (ret == FAIL)
672 	clear_tv(rettv);
673 
674     return ret;
675 }
676 
677 /*
678  * Call Vim script function "func" and return the result as a number.
679  * Returns -1 when calling the function fails.
680  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
681  * have type VAR_UNKNOWN.
682  */
683     varnumber_T
684 call_func_retnr(
685     char_u      *func,
686     int		argc,
687     typval_T	*argv)
688 {
689     typval_T	rettv;
690     varnumber_T	retval;
691 
692     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
693 	return -1;
694 
695     retval = tv_get_number_chk(&rettv, NULL);
696     clear_tv(&rettv);
697     return retval;
698 }
699 
700 /*
701  * Call Vim script function like call_func_retnr() and drop the result.
702  * Returns FAIL when calling the function fails.
703  */
704     int
705 call_func_noret(
706     char_u      *func,
707     int		argc,
708     typval_T	*argv)
709 {
710     typval_T	rettv;
711 
712     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
713 	return FAIL;
714     clear_tv(&rettv);
715     return OK;
716 }
717 
718 /*
719  * Call Vim script function "func" and return the result as a string.
720  * Uses "argv" and "argc" as call_func_retnr().
721  * Returns NULL when calling the function fails.
722  */
723     void *
724 call_func_retstr(
725     char_u      *func,
726     int		argc,
727     typval_T	*argv)
728 {
729     typval_T	rettv;
730     char_u	*retval;
731 
732     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
733 	return NULL;
734 
735     retval = vim_strsave(tv_get_string(&rettv));
736     clear_tv(&rettv);
737     return retval;
738 }
739 
740 /*
741  * Call Vim script function "func" and return the result as a List.
742  * Uses "argv" and "argc" as call_func_retnr().
743  * Returns NULL when there is something wrong.
744  */
745     void *
746 call_func_retlist(
747     char_u      *func,
748     int		argc,
749     typval_T	*argv)
750 {
751     typval_T	rettv;
752 
753     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
754 	return NULL;
755 
756     if (rettv.v_type != VAR_LIST)
757     {
758 	clear_tv(&rettv);
759 	return NULL;
760     }
761 
762     return rettv.vval.v_list;
763 }
764 
765 #ifdef FEAT_FOLDING
766 /*
767  * Evaluate "arg", which is 'foldexpr'.
768  * Note: caller must set "curwin" to match "arg".
769  * Returns the foldlevel, and any character preceding it in "*cp".  Doesn't
770  * give error messages.
771  */
772     int
773 eval_foldexpr(char_u *arg, int *cp)
774 {
775     typval_T	tv;
776     varnumber_T	retval;
777     char_u	*s;
778     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
779 								   OPT_LOCAL);
780 
781     ++emsg_off;
782     if (use_sandbox)
783 	++sandbox;
784     ++textwinlock;
785     *cp = NUL;
786     if (eval0(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
787 	retval = 0;
788     else
789     {
790 	// If the result is a number, just return the number.
791 	if (tv.v_type == VAR_NUMBER)
792 	    retval = tv.vval.v_number;
793 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
794 	    retval = 0;
795 	else
796 	{
797 	    // If the result is a string, check if there is a non-digit before
798 	    // the number.
799 	    s = tv.vval.v_string;
800 	    if (!VIM_ISDIGIT(*s) && *s != '-')
801 		*cp = *s++;
802 	    retval = atol((char *)s);
803 	}
804 	clear_tv(&tv);
805     }
806     --emsg_off;
807     if (use_sandbox)
808 	--sandbox;
809     --textwinlock;
810     clear_evalarg(&EVALARG_EVALUATE, NULL);
811 
812     return (int)retval;
813 }
814 #endif
815 
816 /*
817  * Get an lval: variable, Dict item or List item that can be assigned a value
818  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
819  * "name.key", "name.key[expr]" etc.
820  * Indexing only works if "name" is an existing List or Dictionary.
821  * "name" points to the start of the name.
822  * If "rettv" is not NULL it points to the value to be assigned.
823  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
824  * wrong; must end in space or cmd separator.
825  *
826  * flags:
827  *  GLV_QUIET:       do not give error messages
828  *  GLV_READ_ONLY:   will not change the variable
829  *  GLV_NO_AUTOLOAD: do not use script autoloading
830  *
831  * Returns a pointer to just after the name, including indexes.
832  * When an evaluation error occurs "lp->ll_name" is NULL;
833  * Returns NULL for a parsing error.  Still need to free items in "lp"!
834  */
835     char_u *
836 get_lval(
837     char_u	*name,
838     typval_T	*rettv,
839     lval_T	*lp,
840     int		unlet,
841     int		skip,
842     int		flags,	    // GLV_ values
843     int		fne_flags)  // flags for find_name_end()
844 {
845     char_u	*p;
846     char_u	*expr_start, *expr_end;
847     int		cc;
848     dictitem_T	*v;
849     typval_T	var1;
850     typval_T	var2;
851     int		empty1 = FALSE;
852     listitem_T	*ni;
853     char_u	*key = NULL;
854     int		len;
855     hashtab_T	*ht = NULL;
856     int		quiet = flags & GLV_QUIET;
857     int		writing;
858 
859     // Clear everything in "lp".
860     CLEAR_POINTER(lp);
861 
862     if (skip || (flags & GLV_COMPILING))
863     {
864 	// When skipping or compiling just find the end of the name.
865 	lp->ll_name = name;
866 	lp->ll_name_end = find_name_end(name, NULL, NULL,
867 						      FNE_INCL_BR | fne_flags);
868 	return lp->ll_name_end;
869     }
870 
871     // Find the end of the name.
872     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
873     lp->ll_name_end = p;
874     if (expr_start != NULL)
875     {
876 	// Don't expand the name when we already know there is an error.
877 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
878 						    && *p != '[' && *p != '.')
879 	{
880 	    semsg(_(e_trailing_arg), p);
881 	    return NULL;
882 	}
883 
884 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
885 	if (lp->ll_exp_name == NULL)
886 	{
887 	    // Report an invalid expression in braces, unless the
888 	    // expression evaluation has been cancelled due to an
889 	    // aborting error, an interrupt, or an exception.
890 	    if (!aborting() && !quiet)
891 	    {
892 		emsg_severe = TRUE;
893 		semsg(_(e_invarg2), name);
894 		return NULL;
895 	    }
896 	}
897 	lp->ll_name = lp->ll_exp_name;
898     }
899     else
900     {
901 	lp->ll_name = name;
902 
903 	if (in_vim9script())
904 	{
905 	    // "a: type" is declaring variable "a" with a type, not "a:".
906 	    if (p == name + 2 && p[-1] == ':')
907 	    {
908 		--p;
909 		lp->ll_name_end = p;
910 	    }
911 	    if (*p == ':')
912 	    {
913 		scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);
914 		char_u	 *tp = skipwhite(p + 1);
915 
916 		// parse the type after the name
917 		lp->ll_type = parse_type(&tp, &si->sn_type_list, !quiet);
918 		if (lp->ll_type == NULL && !quiet)
919 		    return NULL;
920 		lp->ll_name_end = tp;
921 	    }
922 	}
923     }
924 
925     // Without [idx] or .key we are done.
926     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
927 	return p;
928 
929     cc = *p;
930     *p = NUL;
931     // When we would write to the variable pass &ht and prevent autoload.
932     writing = !(flags & GLV_READ_ONLY);
933     v = find_var(lp->ll_name, writing ? &ht : NULL,
934 					 (flags & GLV_NO_AUTOLOAD) || writing);
935     if (v == NULL && !quiet)
936 	semsg(_(e_undefined_variable_str), lp->ll_name);
937     *p = cc;
938     if (v == NULL)
939 	return NULL;
940 
941     if (in_vim9script() && (flags & GLV_NO_DECL) == 0)
942     {
943 	if (!quiet)
944 	    semsg(_(e_variable_already_declared), lp->ll_name);
945 	return NULL;
946     }
947 
948     /*
949      * Loop until no more [idx] or .key is following.
950      */
951     lp->ll_tv = &v->di_tv;
952     var1.v_type = VAR_UNKNOWN;
953     var2.v_type = VAR_UNKNOWN;
954     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
955     {
956 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
957 		&& !(lp->ll_tv->v_type == VAR_DICT)
958 		&& !(lp->ll_tv->v_type == VAR_BLOB
959 					   && lp->ll_tv->vval.v_blob != NULL))
960 	{
961 	    if (!quiet)
962 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
963 	    return NULL;
964 	}
965 	if (lp->ll_range)
966 	{
967 	    if (!quiet)
968 		emsg(_("E708: [:] must come last"));
969 	    return NULL;
970 	}
971 
972 	if (in_vim9script() && lp->ll_valtype == NULL
973 		&& lp->ll_tv == &v->di_tv
974 		&& ht != NULL && ht == get_script_local_ht())
975 	{
976 	    svar_T  *sv = find_typval_in_script(lp->ll_tv);
977 
978 	    // Vim9 script local variable: get the type
979 	    if (sv != NULL)
980 		lp->ll_valtype = sv->sv_type;
981 	}
982 
983 	len = -1;
984 	if (*p == '.')
985 	{
986 	    key = p + 1;
987 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
988 		;
989 	    if (len == 0)
990 	    {
991 		if (!quiet)
992 		    emsg(_(e_emptykey));
993 		return NULL;
994 	    }
995 	    p = key + len;
996 	}
997 	else
998 	{
999 	    // Get the index [expr] or the first index [expr: ].
1000 	    p = skipwhite(p + 1);
1001 	    if (*p == ':')
1002 		empty1 = TRUE;
1003 	    else
1004 	    {
1005 		empty1 = FALSE;
1006 		if (eval1(&p, &var1, &EVALARG_EVALUATE) == FAIL)  // recursive!
1007 		    return NULL;
1008 		if (tv_get_string_chk(&var1) == NULL)
1009 		{
1010 		    // not a number or string
1011 		    clear_tv(&var1);
1012 		    return NULL;
1013 		}
1014 		p = skipwhite(p);
1015 	    }
1016 
1017 	    // Optionally get the second index [ :expr].
1018 	    if (*p == ':')
1019 	    {
1020 		if (lp->ll_tv->v_type == VAR_DICT)
1021 		{
1022 		    if (!quiet)
1023 			emsg(_(e_cannot_slice_dictionary));
1024 		    clear_tv(&var1);
1025 		    return NULL;
1026 		}
1027 		if (rettv != NULL
1028 			&& !(rettv->v_type == VAR_LIST
1029 						 && rettv->vval.v_list != NULL)
1030 			&& !(rettv->v_type == VAR_BLOB
1031 						&& rettv->vval.v_blob != NULL))
1032 		{
1033 		    if (!quiet)
1034 			emsg(_("E709: [:] requires a List or Blob value"));
1035 		    clear_tv(&var1);
1036 		    return NULL;
1037 		}
1038 		p = skipwhite(p + 1);
1039 		if (*p == ']')
1040 		    lp->ll_empty2 = TRUE;
1041 		else
1042 		{
1043 		    lp->ll_empty2 = FALSE;
1044 		    // recursive!
1045 		    if (eval1(&p, &var2, &EVALARG_EVALUATE) == FAIL)
1046 		    {
1047 			clear_tv(&var1);
1048 			return NULL;
1049 		    }
1050 		    if (tv_get_string_chk(&var2) == NULL)
1051 		    {
1052 			// not a number or string
1053 			clear_tv(&var1);
1054 			clear_tv(&var2);
1055 			return NULL;
1056 		    }
1057 		}
1058 		lp->ll_range = TRUE;
1059 	    }
1060 	    else
1061 		lp->ll_range = FALSE;
1062 
1063 	    if (*p != ']')
1064 	    {
1065 		if (!quiet)
1066 		    emsg(_(e_missbrac));
1067 		clear_tv(&var1);
1068 		clear_tv(&var2);
1069 		return NULL;
1070 	    }
1071 
1072 	    // Skip to past ']'.
1073 	    ++p;
1074 	}
1075 
1076 	if (lp->ll_tv->v_type == VAR_DICT)
1077 	{
1078 	    if (len == -1)
1079 	    {
1080 		// "[key]": get key from "var1"
1081 		key = tv_get_string_chk(&var1);	// is number or string
1082 		if (key == NULL)
1083 		{
1084 		    clear_tv(&var1);
1085 		    return NULL;
1086 		}
1087 	    }
1088 	    lp->ll_list = NULL;
1089 
1090 	    // a NULL dict is equivalent with an empty dict
1091 	    if (lp->ll_tv->vval.v_dict == NULL)
1092 	    {
1093 		lp->ll_tv->vval.v_dict = dict_alloc();
1094 		if (lp->ll_tv->vval.v_dict == NULL)
1095 		{
1096 		    clear_tv(&var1);
1097 		    return NULL;
1098 		}
1099 		++lp->ll_tv->vval.v_dict->dv_refcount;
1100 	    }
1101 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
1102 
1103 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
1104 
1105 	    // When assigning to a scope dictionary check that a function and
1106 	    // variable name is valid (only variable name unless it is l: or
1107 	    // g: dictionary). Disallow overwriting a builtin function.
1108 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
1109 	    {
1110 		int prevval;
1111 		int wrong;
1112 
1113 		if (len != -1)
1114 		{
1115 		    prevval = key[len];
1116 		    key[len] = NUL;
1117 		}
1118 		else
1119 		    prevval = 0; // avoid compiler warning
1120 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
1121 			       && rettv->v_type == VAR_FUNC
1122 			       && var_wrong_func_name(key, lp->ll_di == NULL))
1123 			|| !valid_varname(key, TRUE);
1124 		if (len != -1)
1125 		    key[len] = prevval;
1126 		if (wrong)
1127 		{
1128 		    clear_tv(&var1);
1129 		    return NULL;
1130 		}
1131 	    }
1132 
1133 	    if (lp->ll_valtype != NULL)
1134 		// use the type of the member
1135 		lp->ll_valtype = lp->ll_valtype->tt_member;
1136 
1137 	    if (lp->ll_di == NULL)
1138 	    {
1139 		// Can't add "v:" or "a:" variable.
1140 		if (lp->ll_dict == get_vimvar_dict()
1141 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
1142 		{
1143 		    semsg(_(e_illvar), name);
1144 		    clear_tv(&var1);
1145 		    return NULL;
1146 		}
1147 
1148 		// Key does not exist in dict: may need to add it.
1149 		if (*p == '[' || *p == '.' || unlet)
1150 		{
1151 		    if (!quiet)
1152 			semsg(_(e_dictkey), key);
1153 		    clear_tv(&var1);
1154 		    return NULL;
1155 		}
1156 		if (len == -1)
1157 		    lp->ll_newkey = vim_strsave(key);
1158 		else
1159 		    lp->ll_newkey = vim_strnsave(key, len);
1160 		clear_tv(&var1);
1161 		if (lp->ll_newkey == NULL)
1162 		    p = NULL;
1163 		break;
1164 	    }
1165 	    // existing variable, need to check if it can be changed
1166 	    else if ((flags & GLV_READ_ONLY) == 0
1167 			&& (var_check_ro(lp->ll_di->di_flags, name, FALSE)
1168 			  || var_check_lock(lp->ll_di->di_flags, name, FALSE)))
1169 	    {
1170 		clear_tv(&var1);
1171 		return NULL;
1172 	    }
1173 
1174 	    clear_tv(&var1);
1175 	    lp->ll_tv = &lp->ll_di->di_tv;
1176 	}
1177 	else if (lp->ll_tv->v_type == VAR_BLOB)
1178 	{
1179 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
1180 
1181 	    /*
1182 	     * Get the number and item for the only or first index of the List.
1183 	     */
1184 	    if (empty1)
1185 		lp->ll_n1 = 0;
1186 	    else
1187 		// is number or string
1188 		lp->ll_n1 = (long)tv_get_number(&var1);
1189 	    clear_tv(&var1);
1190 
1191 	    if (check_blob_index(bloblen, lp->ll_n1, quiet) == FAIL)
1192 	    {
1193 		clear_tv(&var2);
1194 		return NULL;
1195 	    }
1196 	    if (lp->ll_range && !lp->ll_empty2)
1197 	    {
1198 		lp->ll_n2 = (long)tv_get_number(&var2);
1199 		clear_tv(&var2);
1200 		if (check_blob_range(bloblen, lp->ll_n1, lp->ll_n2, quiet)
1201 								       == FAIL)
1202 		    return NULL;
1203 	    }
1204 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
1205 	    lp->ll_tv = NULL;
1206 	    break;
1207 	}
1208 	else
1209 	{
1210 	    /*
1211 	     * Get the number and item for the only or first index of the List.
1212 	     */
1213 	    if (empty1)
1214 		lp->ll_n1 = 0;
1215 	    else
1216 		// is number or string
1217 		lp->ll_n1 = (long)tv_get_number(&var1);
1218 	    clear_tv(&var1);
1219 
1220 	    lp->ll_dict = NULL;
1221 	    lp->ll_list = lp->ll_tv->vval.v_list;
1222 	    lp->ll_li = list_find_index(lp->ll_list, &lp->ll_n1);
1223 	    if (lp->ll_li == NULL)
1224 	    {
1225 		clear_tv(&var2);
1226 		if (!quiet)
1227 		    semsg(_(e_listidx), lp->ll_n1);
1228 		return NULL;
1229 	    }
1230 
1231 	    if (lp->ll_valtype != NULL)
1232 		// use the type of the member
1233 		lp->ll_valtype = lp->ll_valtype->tt_member;
1234 
1235 	    /*
1236 	     * May need to find the item or absolute index for the second
1237 	     * index of a range.
1238 	     * When no index given: "lp->ll_empty2" is TRUE.
1239 	     * Otherwise "lp->ll_n2" is set to the second index.
1240 	     */
1241 	    if (lp->ll_range && !lp->ll_empty2)
1242 	    {
1243 		lp->ll_n2 = (long)tv_get_number(&var2);
1244 						    // is number or string
1245 		clear_tv(&var2);
1246 		if (lp->ll_n2 < 0)
1247 		{
1248 		    ni = list_find(lp->ll_list, lp->ll_n2);
1249 		    if (ni == NULL)
1250 		    {
1251 			if (!quiet)
1252 			    semsg(_(e_listidx), lp->ll_n2);
1253 			return NULL;
1254 		    }
1255 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
1256 		}
1257 
1258 		// Check that lp->ll_n2 isn't before lp->ll_n1.
1259 		if (lp->ll_n1 < 0)
1260 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
1261 		if (lp->ll_n2 < lp->ll_n1)
1262 		{
1263 		    if (!quiet)
1264 			semsg(_(e_listidx), lp->ll_n2);
1265 		    return NULL;
1266 		}
1267 	    }
1268 
1269 	    lp->ll_tv = &lp->ll_li->li_tv;
1270 	}
1271     }
1272 
1273     clear_tv(&var1);
1274     lp->ll_name_end = p;
1275     return p;
1276 }
1277 
1278 /*
1279  * Clear lval "lp" that was filled by get_lval().
1280  */
1281     void
1282 clear_lval(lval_T *lp)
1283 {
1284     vim_free(lp->ll_exp_name);
1285     vim_free(lp->ll_newkey);
1286 }
1287 
1288 /*
1289  * Set a variable that was parsed by get_lval() to "rettv".
1290  * "endp" points to just after the parsed name.
1291  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
1292  * "%" for "%=", "." for ".=" or "=" for "=".
1293  */
1294     void
1295 set_var_lval(
1296     lval_T	*lp,
1297     char_u	*endp,
1298     typval_T	*rettv,
1299     int		copy,
1300     int		flags,	    // ASSIGN_CONST, ASSIGN_NO_DECL
1301     char_u	*op,
1302     int		var_idx)    // index for "let [a, b] = list"
1303 {
1304     int		cc;
1305     listitem_T	*ri;
1306     dictitem_T	*di;
1307 
1308     if (lp->ll_tv == NULL)
1309     {
1310 	cc = *endp;
1311 	*endp = NUL;
1312 	if (in_vim9script() && check_reserved_name(lp->ll_name) == FAIL)
1313 	    return;
1314 
1315 	if (lp->ll_blob != NULL)
1316 	{
1317 	    int	    error = FALSE, val;
1318 
1319 	    if (op != NULL && *op != '=')
1320 	    {
1321 		semsg(_(e_letwrong), op);
1322 		return;
1323 	    }
1324 	    if (value_check_lock(lp->ll_blob->bv_lock, lp->ll_name, FALSE))
1325 		return;
1326 
1327 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
1328 	    {
1329 		if (lp->ll_empty2)
1330 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
1331 
1332 		if (blob_set_range(lp->ll_blob, lp->ll_n1, lp->ll_n2,
1333 								rettv) == FAIL)
1334 		    return;
1335 	    }
1336 	    else
1337 	    {
1338 		val = (int)tv_get_number_chk(rettv, &error);
1339 		if (!error)
1340 		    blob_set_append(lp->ll_blob, lp->ll_n1, val);
1341 	    }
1342 	}
1343 	else if (op != NULL && *op != '=')
1344 	{
1345 	    typval_T tv;
1346 
1347 	    if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
1348 					     && (flags & ASSIGN_FOR_LOOP) == 0)
1349 	    {
1350 		emsg(_(e_cannot_mod));
1351 		*endp = cc;
1352 		return;
1353 	    }
1354 
1355 	    // handle +=, -=, *=, /=, %= and .=
1356 	    di = NULL;
1357 	    if (eval_variable(lp->ll_name, (int)STRLEN(lp->ll_name),
1358 					     &tv, &di, EVAL_VAR_VERBOSE) == OK)
1359 	    {
1360 		if ((di == NULL
1361 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
1362 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
1363 			&& tv_op(&tv, rettv, op) == OK)
1364 		    set_var(lp->ll_name, &tv, FALSE);
1365 		clear_tv(&tv);
1366 	    }
1367 	}
1368 	else
1369 	{
1370 	    if (lp->ll_type != NULL
1371 		       && check_typval_arg_type(lp->ll_type, rettv, 0) == FAIL)
1372 		return;
1373 	    set_var_const(lp->ll_name, lp->ll_type, rettv, copy,
1374 							       flags, var_idx);
1375 	}
1376 	*endp = cc;
1377     }
1378     else if (value_check_lock(lp->ll_newkey == NULL
1379 		? lp->ll_tv->v_lock
1380 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
1381 	;
1382     else if (lp->ll_range)
1383     {
1384 	listitem_T *ll_li = lp->ll_li;
1385 	int	    ll_n1 = lp->ll_n1;
1386 
1387 	if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
1388 					     && (flags & ASSIGN_FOR_LOOP) == 0)
1389 	{
1390 	    emsg(_("E996: Cannot lock a range"));
1391 	    return;
1392 	}
1393 
1394 	/*
1395 	 * Check whether any of the list items is locked
1396 	 */
1397 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
1398 	{
1399 	    if (value_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
1400 		return;
1401 	    ri = ri->li_next;
1402 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
1403 		break;
1404 	    ll_li = ll_li->li_next;
1405 	    ++ll_n1;
1406 	}
1407 
1408 	/*
1409 	 * Assign the List values to the list items.
1410 	 */
1411 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
1412 	{
1413 	    if (op != NULL && *op != '=')
1414 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
1415 	    else
1416 	    {
1417 		clear_tv(&lp->ll_li->li_tv);
1418 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
1419 	    }
1420 	    ri = ri->li_next;
1421 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
1422 		break;
1423 	    if (lp->ll_li->li_next == NULL)
1424 	    {
1425 		// Need to add an empty item.
1426 		if (list_append_number(lp->ll_list, 0) == FAIL)
1427 		{
1428 		    ri = NULL;
1429 		    break;
1430 		}
1431 	    }
1432 	    lp->ll_li = lp->ll_li->li_next;
1433 	    ++lp->ll_n1;
1434 	}
1435 	if (ri != NULL)
1436 	    emsg(_(e_list_value_has_more_items_than_targets));
1437 	else if (lp->ll_empty2
1438 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
1439 		: lp->ll_n1 != lp->ll_n2)
1440 	    emsg(_(e_list_value_does_not_have_enough_items));
1441     }
1442     else
1443     {
1444 	/*
1445 	 * Assign to a List or Dictionary item.
1446 	 */
1447 	if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
1448 					     && (flags & ASSIGN_FOR_LOOP) == 0)
1449 	{
1450 	    emsg(_("E996: Cannot lock a list or dict"));
1451 	    return;
1452 	}
1453 
1454 	if (lp->ll_valtype != NULL
1455 		    && check_typval_arg_type(lp->ll_valtype, rettv, 0) == FAIL)
1456 	    return;
1457 
1458 	if (lp->ll_newkey != NULL)
1459 	{
1460 	    if (op != NULL && *op != '=')
1461 	    {
1462 		semsg(_(e_dictkey), lp->ll_newkey);
1463 		return;
1464 	    }
1465 
1466 	    // Need to add an item to the Dictionary.
1467 	    di = dictitem_alloc(lp->ll_newkey);
1468 	    if (di == NULL)
1469 		return;
1470 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
1471 	    {
1472 		vim_free(di);
1473 		return;
1474 	    }
1475 	    lp->ll_tv = &di->di_tv;
1476 	}
1477 	else if (op != NULL && *op != '=')
1478 	{
1479 	    tv_op(lp->ll_tv, rettv, op);
1480 	    return;
1481 	}
1482 	else
1483 	    clear_tv(lp->ll_tv);
1484 
1485 	/*
1486 	 * Assign the value to the variable or list item.
1487 	 */
1488 	if (copy)
1489 	    copy_tv(rettv, lp->ll_tv);
1490 	else
1491 	{
1492 	    *lp->ll_tv = *rettv;
1493 	    lp->ll_tv->v_lock = 0;
1494 	    init_tv(rettv);
1495 	}
1496     }
1497 }
1498 
1499 /*
1500  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
1501  * and "tv1 .= tv2"
1502  * Returns OK or FAIL.
1503  */
1504     static int
1505 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
1506 {
1507     varnumber_T	n;
1508     char_u	numbuf[NUMBUFLEN];
1509     char_u	*s;
1510     int		failed = FALSE;
1511 
1512     // Can't do anything with a Funcref, Dict, v:true on the right.
1513     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
1514 		      && tv2->v_type != VAR_BOOL && tv2->v_type != VAR_SPECIAL)
1515     {
1516 	switch (tv1->v_type)
1517 	{
1518 	    case VAR_UNKNOWN:
1519 	    case VAR_ANY:
1520 	    case VAR_VOID:
1521 	    case VAR_DICT:
1522 	    case VAR_FUNC:
1523 	    case VAR_PARTIAL:
1524 	    case VAR_BOOL:
1525 	    case VAR_SPECIAL:
1526 	    case VAR_JOB:
1527 	    case VAR_CHANNEL:
1528 	    case VAR_INSTR:
1529 		break;
1530 
1531 	    case VAR_BLOB:
1532 		if (*op != '+' || tv2->v_type != VAR_BLOB)
1533 		    break;
1534 		// BLOB += BLOB
1535 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
1536 		{
1537 		    blob_T  *b1 = tv1->vval.v_blob;
1538 		    blob_T  *b2 = tv2->vval.v_blob;
1539 		    int	i, len = blob_len(b2);
1540 		    for (i = 0; i < len; i++)
1541 			ga_append(&b1->bv_ga, blob_get(b2, i));
1542 		}
1543 		return OK;
1544 
1545 	    case VAR_LIST:
1546 		if (*op != '+' || tv2->v_type != VAR_LIST)
1547 		    break;
1548 		// List += List
1549 		if (tv2->vval.v_list != NULL)
1550 		{
1551 		    if (tv1->vval.v_list == NULL)
1552 		    {
1553 			tv1->vval.v_list = tv2->vval.v_list;
1554 			++tv1->vval.v_list->lv_refcount;
1555 		    }
1556 		    else
1557 			list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
1558 		}
1559 		return OK;
1560 
1561 	    case VAR_NUMBER:
1562 	    case VAR_STRING:
1563 		if (tv2->v_type == VAR_LIST)
1564 		    break;
1565 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
1566 		{
1567 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
1568 		    n = tv_get_number(tv1);
1569 #ifdef FEAT_FLOAT
1570 		    if (tv2->v_type == VAR_FLOAT)
1571 		    {
1572 			float_T f = n;
1573 
1574 			if (*op == '%')
1575 			    break;
1576 			switch (*op)
1577 			{
1578 			    case '+': f += tv2->vval.v_float; break;
1579 			    case '-': f -= tv2->vval.v_float; break;
1580 			    case '*': f *= tv2->vval.v_float; break;
1581 			    case '/': f /= tv2->vval.v_float; break;
1582 			}
1583 			clear_tv(tv1);
1584 			tv1->v_type = VAR_FLOAT;
1585 			tv1->vval.v_float = f;
1586 		    }
1587 		    else
1588 #endif
1589 		    {
1590 			switch (*op)
1591 			{
1592 			    case '+': n += tv_get_number(tv2); break;
1593 			    case '-': n -= tv_get_number(tv2); break;
1594 			    case '*': n *= tv_get_number(tv2); break;
1595 			    case '/': n = num_divide(n, tv_get_number(tv2),
1596 							       &failed); break;
1597 			    case '%': n = num_modulus(n, tv_get_number(tv2),
1598 							       &failed); break;
1599 			}
1600 			clear_tv(tv1);
1601 			tv1->v_type = VAR_NUMBER;
1602 			tv1->vval.v_number = n;
1603 		    }
1604 		}
1605 		else
1606 		{
1607 		    if (tv2->v_type == VAR_FLOAT)
1608 			break;
1609 
1610 		    // str .= str
1611 		    s = tv_get_string(tv1);
1612 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
1613 		    clear_tv(tv1);
1614 		    tv1->v_type = VAR_STRING;
1615 		    tv1->vval.v_string = s;
1616 		}
1617 		return failed ? FAIL : OK;
1618 
1619 	    case VAR_FLOAT:
1620 #ifdef FEAT_FLOAT
1621 		{
1622 		    float_T f;
1623 
1624 		    if (*op == '%' || *op == '.'
1625 				   || (tv2->v_type != VAR_FLOAT
1626 				    && tv2->v_type != VAR_NUMBER
1627 				    && tv2->v_type != VAR_STRING))
1628 			break;
1629 		    if (tv2->v_type == VAR_FLOAT)
1630 			f = tv2->vval.v_float;
1631 		    else
1632 			f = tv_get_number(tv2);
1633 		    switch (*op)
1634 		    {
1635 			case '+': tv1->vval.v_float += f; break;
1636 			case '-': tv1->vval.v_float -= f; break;
1637 			case '*': tv1->vval.v_float *= f; break;
1638 			case '/': tv1->vval.v_float /= f; break;
1639 		    }
1640 		}
1641 #endif
1642 		return OK;
1643 	}
1644     }
1645 
1646     semsg(_(e_letwrong), op);
1647     return FAIL;
1648 }
1649 
1650 /*
1651  * Evaluate the expression used in a ":for var in expr" command.
1652  * "arg" points to "var".
1653  * Set "*errp" to TRUE for an error, FALSE otherwise;
1654  * Return a pointer that holds the info.  Null when there is an error.
1655  */
1656     void *
1657 eval_for_line(
1658     char_u	*arg,
1659     int		*errp,
1660     exarg_T	*eap,
1661     evalarg_T	*evalarg)
1662 {
1663     forinfo_T	*fi;
1664     char_u	*expr;
1665     typval_T	tv;
1666     list_T	*l;
1667     int		skip = !(evalarg->eval_flags & EVAL_EVALUATE);
1668 
1669     *errp = TRUE;	// default: there is an error
1670 
1671     fi = ALLOC_CLEAR_ONE(forinfo_T);
1672     if (fi == NULL)
1673 	return NULL;
1674 
1675     expr = skip_var_list(arg, TRUE, &fi->fi_varcount, &fi->fi_semicolon, FALSE);
1676     if (expr == NULL)
1677 	return fi;
1678 
1679     expr = skipwhite_and_linebreak(expr, evalarg);
1680     if (expr[0] != 'i' || expr[1] != 'n'
1681 				  || !(expr[2] == NUL || VIM_ISWHITE(expr[2])))
1682     {
1683 	emsg(_(e_missing_in));
1684 	return fi;
1685     }
1686 
1687     if (skip)
1688 	++emsg_skip;
1689     expr = skipwhite_and_linebreak(expr + 2, evalarg);
1690     if (eval0(expr, &tv, eap, evalarg) == OK)
1691     {
1692 	*errp = FALSE;
1693 	if (!skip)
1694 	{
1695 	    if (tv.v_type == VAR_LIST)
1696 	    {
1697 		l = tv.vval.v_list;
1698 		if (l == NULL)
1699 		{
1700 		    // a null list is like an empty list: do nothing
1701 		    clear_tv(&tv);
1702 		}
1703 		else
1704 		{
1705 		    // Need a real list here.
1706 		    CHECK_LIST_MATERIALIZE(l);
1707 
1708 		    // No need to increment the refcount, it's already set for
1709 		    // the list being used in "tv".
1710 		    fi->fi_list = l;
1711 		    list_add_watch(l, &fi->fi_lw);
1712 		    fi->fi_lw.lw_item = l->lv_first;
1713 		}
1714 	    }
1715 	    else if (tv.v_type == VAR_BLOB)
1716 	    {
1717 		fi->fi_bi = 0;
1718 		if (tv.vval.v_blob != NULL)
1719 		{
1720 		    typval_T btv;
1721 
1722 		    // Make a copy, so that the iteration still works when the
1723 		    // blob is changed.
1724 		    blob_copy(tv.vval.v_blob, &btv);
1725 		    fi->fi_blob = btv.vval.v_blob;
1726 		}
1727 		clear_tv(&tv);
1728 	    }
1729 	    else if (tv.v_type == VAR_STRING)
1730 	    {
1731 		fi->fi_byte_idx = 0;
1732 		fi->fi_string = tv.vval.v_string;
1733 		tv.vval.v_string = NULL;
1734 		if (fi->fi_string == NULL)
1735 		    fi->fi_string = vim_strsave((char_u *)"");
1736 	    }
1737 	    else
1738 	    {
1739 		emsg(_(e_listreq));
1740 		clear_tv(&tv);
1741 	    }
1742 	}
1743     }
1744     if (skip)
1745 	--emsg_skip;
1746     fi->fi_break_count = evalarg->eval_break_count;
1747 
1748     return fi;
1749 }
1750 
1751 /*
1752  * Used when looping over a :for line, skip the "in expr" part.
1753  */
1754     void
1755 skip_for_lines(void *fi_void, evalarg_T *evalarg)
1756 {
1757     forinfo_T	*fi = (forinfo_T *)fi_void;
1758     int		i;
1759 
1760     for (i = 0; i < fi->fi_break_count; ++i)
1761 	eval_next_line(evalarg);
1762 }
1763 
1764 /*
1765  * Use the first item in a ":for" list.  Advance to the next.
1766  * Assign the values to the variable (list).  "arg" points to the first one.
1767  * Return TRUE when a valid item was found, FALSE when at end of list or
1768  * something wrong.
1769  */
1770     int
1771 next_for_item(void *fi_void, char_u *arg)
1772 {
1773     forinfo_T	*fi = (forinfo_T *)fi_void;
1774     int		result;
1775     int		flag = ASSIGN_FOR_LOOP | (in_vim9script()
1776 			 ? (ASSIGN_FINAL | ASSIGN_DECL | ASSIGN_NO_MEMBER_TYPE)
1777 			 : 0);
1778     listitem_T	*item;
1779 
1780     if (fi->fi_blob != NULL)
1781     {
1782 	typval_T	tv;
1783 
1784 	if (fi->fi_bi >= blob_len(fi->fi_blob))
1785 	    return FALSE;
1786 	tv.v_type = VAR_NUMBER;
1787 	tv.v_lock = VAR_FIXED;
1788 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
1789 	++fi->fi_bi;
1790 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1791 					    fi->fi_varcount, flag, NULL) == OK;
1792     }
1793 
1794     if (fi->fi_string != NULL)
1795     {
1796 	typval_T	tv;
1797 	int		len;
1798 
1799 	len = mb_ptr2len(fi->fi_string + fi->fi_byte_idx);
1800 	if (len == 0)
1801 	    return FALSE;
1802 	tv.v_type = VAR_STRING;
1803 	tv.v_lock = VAR_FIXED;
1804 	tv.vval.v_string = vim_strnsave(fi->fi_string + fi->fi_byte_idx, len);
1805 	fi->fi_byte_idx += len;
1806 	result = ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1807 					    fi->fi_varcount, flag, NULL) == OK;
1808 	vim_free(tv.vval.v_string);
1809 	return result;
1810     }
1811 
1812     item = fi->fi_lw.lw_item;
1813     if (item == NULL)
1814 	result = FALSE;
1815     else
1816     {
1817 	fi->fi_lw.lw_item = item->li_next;
1818 	result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
1819 					   fi->fi_varcount, flag, NULL) == OK);
1820     }
1821     return result;
1822 }
1823 
1824 /*
1825  * Free the structure used to store info used by ":for".
1826  */
1827     void
1828 free_for_info(void *fi_void)
1829 {
1830     forinfo_T    *fi = (forinfo_T *)fi_void;
1831 
1832     if (fi == NULL)
1833 	return;
1834     if (fi->fi_list != NULL)
1835     {
1836 	list_rem_watch(fi->fi_list, &fi->fi_lw);
1837 	list_unref(fi->fi_list);
1838     }
1839     else if (fi->fi_blob != NULL)
1840 	blob_unref(fi->fi_blob);
1841     else
1842 	vim_free(fi->fi_string);
1843     vim_free(fi);
1844 }
1845 
1846     void
1847 set_context_for_expression(
1848     expand_T	*xp,
1849     char_u	*arg,
1850     cmdidx_T	cmdidx)
1851 {
1852     int		has_expr = cmdidx != CMD_let && cmdidx != CMD_var;
1853     int		c;
1854     char_u	*p;
1855 
1856     if (cmdidx == CMD_let || cmdidx == CMD_var
1857 				 || cmdidx == CMD_const || cmdidx == CMD_final)
1858     {
1859 	xp->xp_context = EXPAND_USER_VARS;
1860 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
1861 	{
1862 	    // ":let var1 var2 ...": find last space.
1863 	    for (p = arg + STRLEN(arg); p >= arg; )
1864 	    {
1865 		xp->xp_pattern = p;
1866 		MB_PTR_BACK(arg, p);
1867 		if (VIM_ISWHITE(*p))
1868 		    break;
1869 	    }
1870 	    return;
1871 	}
1872     }
1873     else
1874 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
1875 							  : EXPAND_EXPRESSION;
1876     while ((xp->xp_pattern = vim_strpbrk(arg,
1877 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
1878     {
1879 	c = *xp->xp_pattern;
1880 	if (c == '&')
1881 	{
1882 	    c = xp->xp_pattern[1];
1883 	    if (c == '&')
1884 	    {
1885 		++xp->xp_pattern;
1886 		xp->xp_context = has_expr ? EXPAND_EXPRESSION : EXPAND_NOTHING;
1887 	    }
1888 	    else if (c != ' ')
1889 	    {
1890 		xp->xp_context = EXPAND_SETTINGS;
1891 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
1892 		    xp->xp_pattern += 2;
1893 
1894 	    }
1895 	}
1896 	else if (c == '$')
1897 	{
1898 	    // environment variable
1899 	    xp->xp_context = EXPAND_ENV_VARS;
1900 	}
1901 	else if (c == '=')
1902 	{
1903 	    has_expr = TRUE;
1904 	    xp->xp_context = EXPAND_EXPRESSION;
1905 	}
1906 	else if (c == '#'
1907 		&& xp->xp_context == EXPAND_EXPRESSION)
1908 	{
1909 	    // Autoload function/variable contains '#'.
1910 	    break;
1911 	}
1912 	else if ((c == '<' || c == '#')
1913 		&& xp->xp_context == EXPAND_FUNCTIONS
1914 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
1915 	{
1916 	    // Function name can start with "<SNR>" and contain '#'.
1917 	    break;
1918 	}
1919 	else if (has_expr)
1920 	{
1921 	    if (c == '"')	    // string
1922 	    {
1923 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
1924 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
1925 			++xp->xp_pattern;
1926 		xp->xp_context = EXPAND_NOTHING;
1927 	    }
1928 	    else if (c == '\'')	    // literal string
1929 	    {
1930 		// Trick: '' is like stopping and starting a literal string.
1931 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
1932 		    /* skip */ ;
1933 		xp->xp_context = EXPAND_NOTHING;
1934 	    }
1935 	    else if (c == '|')
1936 	    {
1937 		if (xp->xp_pattern[1] == '|')
1938 		{
1939 		    ++xp->xp_pattern;
1940 		    xp->xp_context = EXPAND_EXPRESSION;
1941 		}
1942 		else
1943 		    xp->xp_context = EXPAND_COMMANDS;
1944 	    }
1945 	    else
1946 		xp->xp_context = EXPAND_EXPRESSION;
1947 	}
1948 	else
1949 	    // Doesn't look like something valid, expand as an expression
1950 	    // anyway.
1951 	    xp->xp_context = EXPAND_EXPRESSION;
1952 	arg = xp->xp_pattern;
1953 	if (*arg != NUL)
1954 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
1955 		/* skip */ ;
1956     }
1957 
1958     // ":exe one two" completes "two"
1959     if ((cmdidx == CMD_execute
1960 		|| cmdidx == CMD_echo
1961 		|| cmdidx == CMD_echon
1962 		|| cmdidx == CMD_echomsg)
1963 	    && xp->xp_context == EXPAND_EXPRESSION)
1964     {
1965 	for (;;)
1966 	{
1967 	    char_u *n = skiptowhite(arg);
1968 
1969 	    if (n == arg || IS_WHITE_OR_NUL(*skipwhite(n)))
1970 		break;
1971 	    arg = skipwhite(n);
1972 	}
1973     }
1974 
1975     xp->xp_pattern = arg;
1976 }
1977 
1978 /*
1979  * Return TRUE if "pat" matches "text".
1980  * Does not use 'cpo' and always uses 'magic'.
1981  */
1982     int
1983 pattern_match(char_u *pat, char_u *text, int ic)
1984 {
1985     int		matches = FALSE;
1986     char_u	*save_cpo;
1987     regmatch_T	regmatch;
1988 
1989     // avoid 'l' flag in 'cpoptions'
1990     save_cpo = p_cpo;
1991     p_cpo = empty_option;
1992     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1993     if (regmatch.regprog != NULL)
1994     {
1995 	regmatch.rm_ic = ic;
1996 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
1997 	vim_regfree(regmatch.regprog);
1998     }
1999     p_cpo = save_cpo;
2000     return matches;
2001 }
2002 
2003 /*
2004  * Handle a name followed by "(".  Both for just "name(arg)" and for
2005  * "expr->name(arg)".
2006  * Returns OK or FAIL.
2007  */
2008     static int
2009 eval_func(
2010 	char_u	    **arg,	// points to "(", will be advanced
2011 	evalarg_T   *evalarg,
2012 	char_u	    *name,
2013 	int	    name_len,
2014 	typval_T    *rettv,
2015 	int	    flags,
2016 	typval_T    *basetv)	// "expr" for "expr->name(arg)"
2017 {
2018     int		evaluate = flags & EVAL_EVALUATE;
2019     char_u	*s = name;
2020     int		len = name_len;
2021     partial_T	*partial;
2022     int		ret = OK;
2023     type_T	*type = NULL;
2024 
2025     if (!evaluate)
2026 	check_vars(s, len);
2027 
2028     // If "s" is the name of a variable of type VAR_FUNC
2029     // use its contents.
2030     s = deref_func_name(s, &len, &partial,
2031 				    in_vim9script() ? &type : NULL, !evaluate);
2032 
2033     // Need to make a copy, in case evaluating the arguments makes
2034     // the name invalid.
2035     s = vim_strsave(s);
2036     if (s == NULL || (flags & EVAL_CONSTANT))
2037 	ret = FAIL;
2038     else
2039     {
2040 	funcexe_T funcexe;
2041 
2042 	// Invoke the function.
2043 	CLEAR_FIELD(funcexe);
2044 	funcexe.firstline = curwin->w_cursor.lnum;
2045 	funcexe.lastline = curwin->w_cursor.lnum;
2046 	funcexe.evaluate = evaluate;
2047 	funcexe.partial = partial;
2048 	funcexe.basetv = basetv;
2049 	funcexe.check_type = type;
2050 	ret = get_func_tv(s, len, rettv, arg, evalarg, &funcexe);
2051     }
2052     vim_free(s);
2053 
2054     // If evaluate is FALSE rettv->v_type was not set in
2055     // get_func_tv, but it's needed in handle_subscript() to parse
2056     // what follows. So set it here.
2057     if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
2058     {
2059 	rettv->vval.v_string = NULL;
2060 	rettv->v_type = VAR_FUNC;
2061     }
2062 
2063     // Stop the expression evaluation when immediately
2064     // aborting on error, or when an interrupt occurred or
2065     // an exception was thrown but not caught.
2066     if (evaluate && aborting())
2067     {
2068 	if (ret == OK)
2069 	    clear_tv(rettv);
2070 	ret = FAIL;
2071     }
2072     return ret;
2073 }
2074 
2075 /*
2076  * Get the next line source line without advancing.  But do skip over comment
2077  * lines.
2078  * Only called for Vim9 script.
2079  */
2080     static char_u *
2081 getline_peek_skip_comments(evalarg_T *evalarg)
2082 {
2083     for (;;)
2084     {
2085 	char_u *next = getline_peek(evalarg->eval_getline,
2086 							 evalarg->eval_cookie);
2087 	char_u *p;
2088 
2089 	if (next == NULL)
2090 	    break;
2091 	p = skipwhite(next);
2092 	if (*p != NUL && !vim9_comment_start(p))
2093 	    return next;
2094 	(void)eval_next_line(evalarg);
2095     }
2096     return NULL;
2097 }
2098 
2099 /*
2100  * If inside Vim9 script, "arg" points to the end of a line (ignoring a #
2101  * comment) and there is a next line, return the next line (skipping blanks)
2102  * and set "getnext".
2103  * Otherwise return the next non-white at or after "arg" and set "getnext" to
2104  * FALSE.
2105  * "arg" must point somewhere inside a line, not at the start.
2106  */
2107     char_u *
2108 eval_next_non_blank(char_u *arg, evalarg_T *evalarg, int *getnext)
2109 {
2110     char_u *p = skipwhite(arg);
2111 
2112     *getnext = FALSE;
2113     if (in_vim9script()
2114 	    && evalarg != NULL
2115 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL)
2116 	    && (*p == NUL || (vim9_comment_start(p) && VIM_ISWHITE(p[-1]))))
2117     {
2118 	char_u *next;
2119 
2120 	if (evalarg->eval_cookie != NULL)
2121 	    next = getline_peek_skip_comments(evalarg);
2122 	else
2123 	    next = peek_next_line_from_context(evalarg->eval_cctx);
2124 
2125 	if (next != NULL)
2126 	{
2127 	    *getnext = TRUE;
2128 	    return skipwhite(next);
2129 	}
2130     }
2131     return p;
2132 }
2133 
2134 /*
2135  * To be called after eval_next_non_blank() sets "getnext" to TRUE.
2136  * Only called for Vim9 script.
2137  */
2138     char_u *
2139 eval_next_line(evalarg_T *evalarg)
2140 {
2141     garray_T	*gap = &evalarg->eval_ga;
2142     char_u	*line;
2143 
2144     if (evalarg->eval_cookie != NULL)
2145 	line = evalarg->eval_getline(0, evalarg->eval_cookie, 0,
2146 							   GETLINE_CONCAT_ALL);
2147     else
2148 	line = next_line_from_context(evalarg->eval_cctx, TRUE);
2149     ++evalarg->eval_break_count;
2150     if (gap->ga_itemsize > 0 && ga_grow(gap, 1) == OK)
2151     {
2152 	char_u *p = skipwhite(line);
2153 
2154 	// Going to concatenate the lines after parsing.  For an empty or
2155 	// comment line use an empty string.
2156 	if (*p == NUL || vim9_comment_start(p))
2157 	{
2158 	    vim_free(line);
2159 	    line = vim_strsave((char_u *)"");
2160 	}
2161 
2162 	((char_u **)gap->ga_data)[gap->ga_len] = line;
2163 	++gap->ga_len;
2164     }
2165     else if (evalarg->eval_cookie != NULL)
2166     {
2167 	vim_free(evalarg->eval_tofree);
2168 	evalarg->eval_tofree = line;
2169     }
2170     return skipwhite(line);
2171 }
2172 
2173 /*
2174  * Call eval_next_non_blank() and get the next line if needed.
2175  */
2176     char_u *
2177 skipwhite_and_linebreak(char_u *arg, evalarg_T *evalarg)
2178 {
2179     int	    getnext;
2180     char_u  *p = skipwhite(arg);
2181 
2182     if (evalarg == NULL)
2183 	return skipwhite(arg);
2184     eval_next_non_blank(p, evalarg, &getnext);
2185     if (getnext)
2186 	return eval_next_line(evalarg);
2187     return p;
2188 }
2189 
2190 /*
2191  * After using "evalarg" filled from "eap": free the memory.
2192  */
2193     void
2194 clear_evalarg(evalarg_T *evalarg, exarg_T *eap)
2195 {
2196     if (evalarg != NULL)
2197     {
2198 	if (evalarg->eval_tofree != NULL)
2199 	{
2200 	    if (eap != NULL)
2201 	    {
2202 		// We may need to keep the original command line, e.g. for
2203 		// ":let" it has the variable names.  But we may also need the
2204 		// new one, "nextcmd" points into it.  Keep both.
2205 		vim_free(eap->cmdline_tofree);
2206 		eap->cmdline_tofree = *eap->cmdlinep;
2207 		*eap->cmdlinep = evalarg->eval_tofree;
2208 	    }
2209 	    else
2210 		vim_free(evalarg->eval_tofree);
2211 	    evalarg->eval_tofree = NULL;
2212 	}
2213 
2214 	VIM_CLEAR(evalarg->eval_tofree_cmdline);
2215 	VIM_CLEAR(evalarg->eval_tofree_lambda);
2216     }
2217 }
2218 
2219 /*
2220  * The "evaluate" argument: When FALSE, the argument is only parsed but not
2221  * executed.  The function may return OK, but the rettv will be of type
2222  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
2223  */
2224 
2225 /*
2226  * Handle zero level expression.
2227  * This calls eval1() and handles error message and nextcmd.
2228  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
2229  * Note: "rettv.v_lock" is not set.
2230  * "evalarg" can be NULL, EVALARG_EVALUATE or a pointer.
2231  * Return OK or FAIL.
2232  */
2233     int
2234 eval0(
2235     char_u	*arg,
2236     typval_T	*rettv,
2237     exarg_T	*eap,
2238     evalarg_T	*evalarg)
2239 {
2240     int		ret;
2241     char_u	*p;
2242     int		did_emsg_before = did_emsg;
2243     int		called_emsg_before = called_emsg;
2244     int		flags = evalarg == NULL ? 0 : evalarg->eval_flags;
2245 
2246     p = skipwhite(arg);
2247     ret = eval1(&p, rettv, evalarg);
2248     p = skipwhite(p);
2249 
2250     if (ret == FAIL || !ends_excmd2(arg, p))
2251     {
2252 	if (ret != FAIL)
2253 	    clear_tv(rettv);
2254 	/*
2255 	 * Report the invalid expression unless the expression evaluation has
2256 	 * been cancelled due to an aborting error, an interrupt, or an
2257 	 * exception, or we already gave a more specific error.
2258 	 * Also check called_emsg for when using assert_fails().
2259 	 */
2260 	if (!aborting()
2261 		&& did_emsg == did_emsg_before
2262 		&& called_emsg == called_emsg_before
2263 		&& (flags & EVAL_CONSTANT) == 0
2264 		&& (!in_vim9script() || !vim9_bad_comment(p)))
2265 	    semsg(_(e_invexpr2), arg);
2266 
2267 	// Some of the expression may not have been consumed.  Do not check for
2268 	// a next command to avoid more errors, unless "|" is following, which
2269 	// could only be a command separator.
2270 	if (eap != NULL && skipwhite(p)[0] == '|' && skipwhite(p)[1] != '|')
2271 	    eap->nextcmd = check_nextcmd(p);
2272 	return FAIL;
2273     }
2274 
2275     if (eap != NULL)
2276 	eap->nextcmd = check_nextcmd(p);
2277 
2278     return ret;
2279 }
2280 
2281 /*
2282  * Handle top level expression:
2283  *	expr2 ? expr1 : expr1
2284  *	expr2 ?? expr1
2285  *
2286  * "arg" must point to the first non-white of the expression.
2287  * "arg" is advanced to just after the recognized expression.
2288  *
2289  * Note: "rettv.v_lock" is not set.
2290  *
2291  * Return OK or FAIL.
2292  */
2293     int
2294 eval1(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2295 {
2296     char_u  *p;
2297     int	    getnext;
2298 
2299     CLEAR_POINTER(rettv);
2300 
2301     /*
2302      * Get the first variable.
2303      */
2304     if (eval2(arg, rettv, evalarg) == FAIL)
2305 	return FAIL;
2306 
2307     p = eval_next_non_blank(*arg, evalarg, &getnext);
2308     if (*p == '?')
2309     {
2310 	int		op_falsy = p[1] == '?';
2311 	int		result;
2312 	typval_T	var2;
2313 	evalarg_T	*evalarg_used = evalarg;
2314 	evalarg_T	local_evalarg;
2315 	int		orig_flags;
2316 	int		evaluate;
2317 	int		vim9script = in_vim9script();
2318 
2319 	if (evalarg == NULL)
2320 	{
2321 	    CLEAR_FIELD(local_evalarg);
2322 	    evalarg_used = &local_evalarg;
2323 	}
2324 	orig_flags = evalarg_used->eval_flags;
2325 	evaluate = evalarg_used->eval_flags & EVAL_EVALUATE;
2326 
2327 	if (getnext)
2328 	    *arg = eval_next_line(evalarg_used);
2329 	else
2330 	{
2331 	    if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2332 	    {
2333 		error_white_both(p, op_falsy ? 2 : 1);
2334 		clear_tv(rettv);
2335 		return FAIL;
2336 	    }
2337 	    *arg = p;
2338 	}
2339 
2340 	result = FALSE;
2341 	if (evaluate)
2342 	{
2343 	    int		error = FALSE;
2344 
2345 	    if (op_falsy)
2346 		result = tv2bool(rettv);
2347 	    else if (vim9script)
2348 		result = tv_get_bool_chk(rettv, &error);
2349 	    else if (tv_get_number_chk(rettv, &error) != 0)
2350 		result = TRUE;
2351 	    if (error || !op_falsy || !result)
2352 		clear_tv(rettv);
2353 	    if (error)
2354 		return FAIL;
2355 	}
2356 
2357 	/*
2358 	 * Get the second variable.  Recursive!
2359 	 */
2360 	if (op_falsy)
2361 	    ++*arg;
2362 	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[1]))
2363 	{
2364 	    error_white_both(*arg - (op_falsy ? 1 : 0), op_falsy ? 2 : 1);
2365 	    clear_tv(rettv);
2366 	    return FAIL;
2367 	}
2368 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2369 	evalarg_used->eval_flags = (op_falsy ? !result : result)
2370 				    ? orig_flags : orig_flags & ~EVAL_EVALUATE;
2371 	if (eval1(arg, &var2, evalarg_used) == FAIL)
2372 	{
2373 	    evalarg_used->eval_flags = orig_flags;
2374 	    return FAIL;
2375 	}
2376 	if (!op_falsy || !result)
2377 	    *rettv = var2;
2378 
2379 	if (!op_falsy)
2380 	{
2381 	    /*
2382 	     * Check for the ":".
2383 	     */
2384 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2385 	    if (*p != ':')
2386 	    {
2387 		emsg(_(e_missing_colon));
2388 		if (evaluate && result)
2389 		    clear_tv(rettv);
2390 		evalarg_used->eval_flags = orig_flags;
2391 		return FAIL;
2392 	    }
2393 	    if (getnext)
2394 		*arg = eval_next_line(evalarg_used);
2395 	    else
2396 	    {
2397 		if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2398 		{
2399 		    error_white_both(p, 1);
2400 		    clear_tv(rettv);
2401 		    evalarg_used->eval_flags = orig_flags;
2402 		    return FAIL;
2403 		}
2404 		*arg = p;
2405 	    }
2406 
2407 	    /*
2408 	     * Get the third variable.  Recursive!
2409 	     */
2410 	    if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[1]))
2411 	    {
2412 		error_white_both(*arg, 1);
2413 		clear_tv(rettv);
2414 		evalarg_used->eval_flags = orig_flags;
2415 		return FAIL;
2416 	    }
2417 	    *arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2418 	    evalarg_used->eval_flags = !result ? orig_flags
2419 						 : orig_flags & ~EVAL_EVALUATE;
2420 	    if (eval1(arg, &var2, evalarg_used) == FAIL)
2421 	    {
2422 		if (evaluate && result)
2423 		    clear_tv(rettv);
2424 		evalarg_used->eval_flags = orig_flags;
2425 		return FAIL;
2426 	    }
2427 	    if (evaluate && !result)
2428 		*rettv = var2;
2429 	}
2430 
2431 	if (evalarg == NULL)
2432 	    clear_evalarg(&local_evalarg, NULL);
2433 	else
2434 	    evalarg->eval_flags = orig_flags;
2435     }
2436 
2437     return OK;
2438 }
2439 
2440 /*
2441  * Handle first level expression:
2442  *	expr2 || expr2 || expr2	    logical OR
2443  *
2444  * "arg" must point to the first non-white of the expression.
2445  * "arg" is advanced to just after the recognized expression.
2446  *
2447  * Return OK or FAIL.
2448  */
2449     static int
2450 eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2451 {
2452     char_u	*p;
2453     int		getnext;
2454 
2455     /*
2456      * Get the first variable.
2457      */
2458     if (eval3(arg, rettv, evalarg) == FAIL)
2459 	return FAIL;
2460 
2461     /*
2462      * Handle the  "||" operator.
2463      */
2464     p = eval_next_non_blank(*arg, evalarg, &getnext);
2465     if (p[0] == '|' && p[1] == '|')
2466     {
2467 	evalarg_T   *evalarg_used = evalarg;
2468 	evalarg_T   local_evalarg;
2469 	int	    evaluate;
2470 	int	    orig_flags;
2471 	long	    result = FALSE;
2472 	typval_T    var2;
2473 	int	    error = FALSE;
2474 	int	    vim9script = in_vim9script();
2475 
2476 	if (evalarg == NULL)
2477 	{
2478 	    CLEAR_FIELD(local_evalarg);
2479 	    evalarg_used = &local_evalarg;
2480 	}
2481 	orig_flags = evalarg_used->eval_flags;
2482 	evaluate = orig_flags & EVAL_EVALUATE;
2483 	if (evaluate)
2484 	{
2485 	    if (vim9script)
2486 		result = tv_get_bool_chk(rettv, &error);
2487 	    else if (tv_get_number_chk(rettv, &error) != 0)
2488 		result = TRUE;
2489 	    clear_tv(rettv);
2490 	    if (error)
2491 		return FAIL;
2492 	}
2493 
2494 	/*
2495 	 * Repeat until there is no following "||".
2496 	 */
2497 	while (p[0] == '|' && p[1] == '|')
2498 	{
2499 	    if (getnext)
2500 		*arg = eval_next_line(evalarg_used);
2501 	    else
2502 	    {
2503 		if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2504 		{
2505 		    error_white_both(p, 2);
2506 		    clear_tv(rettv);
2507 		    return FAIL;
2508 		}
2509 		*arg = p;
2510 	    }
2511 
2512 	    /*
2513 	     * Get the second variable.
2514 	     */
2515 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2516 	    {
2517 		error_white_both(*arg, 2);
2518 		clear_tv(rettv);
2519 		return FAIL;
2520 	    }
2521 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2522 	    evalarg_used->eval_flags = !result ? orig_flags
2523 						 : orig_flags & ~EVAL_EVALUATE;
2524 	    if (eval3(arg, &var2, evalarg_used) == FAIL)
2525 		return FAIL;
2526 
2527 	    /*
2528 	     * Compute the result.
2529 	     */
2530 	    if (evaluate && !result)
2531 	    {
2532 		if (vim9script)
2533 		    result = tv_get_bool_chk(&var2, &error);
2534 		else if (tv_get_number_chk(&var2, &error) != 0)
2535 		    result = TRUE;
2536 		clear_tv(&var2);
2537 		if (error)
2538 		    return FAIL;
2539 	    }
2540 	    if (evaluate)
2541 	    {
2542 		if (vim9script)
2543 		{
2544 		    rettv->v_type = VAR_BOOL;
2545 		    rettv->vval.v_number = result ? VVAL_TRUE : VVAL_FALSE;
2546 		}
2547 		else
2548 		{
2549 		    rettv->v_type = VAR_NUMBER;
2550 		    rettv->vval.v_number = result;
2551 		}
2552 	    }
2553 
2554 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2555 	}
2556 
2557 	if (evalarg == NULL)
2558 	    clear_evalarg(&local_evalarg, NULL);
2559 	else
2560 	    evalarg->eval_flags = orig_flags;
2561     }
2562 
2563     return OK;
2564 }
2565 
2566 /*
2567  * Handle second level expression:
2568  *	expr3 && expr3 && expr3	    logical AND
2569  *
2570  * "arg" must point to the first non-white of the expression.
2571  * "arg" is advanced to just after the recognized expression.
2572  *
2573  * Return OK or FAIL.
2574  */
2575     static int
2576 eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2577 {
2578     char_u	*p;
2579     int		getnext;
2580 
2581     /*
2582      * Get the first variable.
2583      */
2584     if (eval4(arg, rettv, evalarg) == FAIL)
2585 	return FAIL;
2586 
2587     /*
2588      * Handle the "&&" operator.
2589      */
2590     p = eval_next_non_blank(*arg, evalarg, &getnext);
2591     if (p[0] == '&' && p[1] == '&')
2592     {
2593 	evalarg_T   *evalarg_used = evalarg;
2594 	evalarg_T   local_evalarg;
2595 	int	    orig_flags;
2596 	int	    evaluate;
2597 	long	    result = TRUE;
2598 	typval_T    var2;
2599 	int	    error = FALSE;
2600 	int	    vim9script = in_vim9script();
2601 
2602 	if (evalarg == NULL)
2603 	{
2604 	    CLEAR_FIELD(local_evalarg);
2605 	    evalarg_used = &local_evalarg;
2606 	}
2607 	orig_flags = evalarg_used->eval_flags;
2608 	evaluate = orig_flags & EVAL_EVALUATE;
2609 	if (evaluate)
2610 	{
2611 	    if (vim9script)
2612 		result = tv_get_bool_chk(rettv, &error);
2613 	    else if (tv_get_number_chk(rettv, &error) == 0)
2614 		result = FALSE;
2615 	    clear_tv(rettv);
2616 	    if (error)
2617 		return FAIL;
2618 	}
2619 
2620 	/*
2621 	 * Repeat until there is no following "&&".
2622 	 */
2623 	while (p[0] == '&' && p[1] == '&')
2624 	{
2625 	    if (getnext)
2626 		*arg = eval_next_line(evalarg_used);
2627 	    else
2628 	    {
2629 		if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2630 		{
2631 		    error_white_both(p, 2);
2632 		    clear_tv(rettv);
2633 		    return FAIL;
2634 		}
2635 		*arg = p;
2636 	    }
2637 
2638 	    /*
2639 	     * Get the second variable.
2640 	     */
2641 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2642 	    {
2643 		error_white_both(*arg, 2);
2644 		clear_tv(rettv);
2645 		return FAIL;
2646 	    }
2647 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2648 	    evalarg_used->eval_flags = result ? orig_flags
2649 						 : orig_flags & ~EVAL_EVALUATE;
2650 	    CLEAR_FIELD(var2);
2651 	    if (eval4(arg, &var2, evalarg_used) == FAIL)
2652 		return FAIL;
2653 
2654 	    /*
2655 	     * Compute the result.
2656 	     */
2657 	    if (evaluate && result)
2658 	    {
2659 		if (vim9script)
2660 		    result = tv_get_bool_chk(&var2, &error);
2661 		else if (tv_get_number_chk(&var2, &error) == 0)
2662 		    result = FALSE;
2663 		clear_tv(&var2);
2664 		if (error)
2665 		    return FAIL;
2666 	    }
2667 	    if (evaluate)
2668 	    {
2669 		if (vim9script)
2670 		{
2671 		    rettv->v_type = VAR_BOOL;
2672 		    rettv->vval.v_number = result ? VVAL_TRUE : VVAL_FALSE;
2673 		}
2674 		else
2675 		{
2676 		    rettv->v_type = VAR_NUMBER;
2677 		    rettv->vval.v_number = result;
2678 		}
2679 	    }
2680 
2681 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2682 	}
2683 
2684 	if (evalarg == NULL)
2685 	    clear_evalarg(&local_evalarg, NULL);
2686 	else
2687 	    evalarg->eval_flags = orig_flags;
2688     }
2689 
2690     return OK;
2691 }
2692 
2693 /*
2694  * Handle third level expression:
2695  *	var1 == var2
2696  *	var1 =~ var2
2697  *	var1 != var2
2698  *	var1 !~ var2
2699  *	var1 > var2
2700  *	var1 >= var2
2701  *	var1 < var2
2702  *	var1 <= var2
2703  *	var1 is var2
2704  *	var1 isnot var2
2705  *
2706  * "arg" must point to the first non-white of the expression.
2707  * "arg" is advanced to just after the recognized expression.
2708  *
2709  * Return OK or FAIL.
2710  */
2711     static int
2712 eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2713 {
2714     char_u	*p;
2715     int		getnext;
2716     exprtype_T	type = EXPR_UNKNOWN;
2717     int		len = 2;
2718     int		type_is = FALSE;
2719 
2720     /*
2721      * Get the first variable.
2722      */
2723     if (eval5(arg, rettv, evalarg) == FAIL)
2724 	return FAIL;
2725 
2726     p = eval_next_non_blank(*arg, evalarg, &getnext);
2727     type = get_compare_type(p, &len, &type_is);
2728 
2729     /*
2730      * If there is a comparative operator, use it.
2731      */
2732     if (type != EXPR_UNKNOWN)
2733     {
2734 	typval_T    var2;
2735 	int	    ic;
2736 	int	    vim9script = in_vim9script();
2737 	int	    evaluate = evalarg == NULL
2738 				   ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2739 
2740 	if (getnext)
2741 	{
2742 	    *arg = eval_next_line(evalarg);
2743 	    p = *arg;
2744 	}
2745 	else if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2746 	{
2747 	    error_white_both(*arg, len);
2748 	    clear_tv(rettv);
2749 	    return FAIL;
2750 	}
2751 
2752 	if (vim9script && type_is && (p[len] == '?' || p[len] == '#'))
2753 	{
2754 	    semsg(_(e_invexpr2), p);
2755 	    clear_tv(rettv);
2756 	    return FAIL;
2757 	}
2758 
2759 	// extra question mark appended: ignore case
2760 	if (p[len] == '?')
2761 	{
2762 	    ic = TRUE;
2763 	    ++len;
2764 	}
2765 	// extra '#' appended: match case
2766 	else if (p[len] == '#')
2767 	{
2768 	    ic = FALSE;
2769 	    ++len;
2770 	}
2771 	// nothing appended: use 'ignorecase' if not in Vim script
2772 	else
2773 	    ic = vim9script ? FALSE : p_ic;
2774 
2775 	/*
2776 	 * Get the second variable.
2777 	 */
2778 	if (evaluate && vim9script && !IS_WHITE_OR_NUL(p[len]))
2779 	{
2780 	    error_white_both(p, len);
2781 	    clear_tv(rettv);
2782 	    return FAIL;
2783 	}
2784 	*arg = skipwhite_and_linebreak(p + len, evalarg);
2785 	if (eval5(arg, &var2, evalarg) == FAIL)
2786 	{
2787 	    clear_tv(rettv);
2788 	    return FAIL;
2789 	}
2790 	if (evaluate)
2791 	{
2792 	    int ret;
2793 
2794 	    if (vim9script && check_compare_types(type, rettv, &var2) == FAIL)
2795 	    {
2796 		ret = FAIL;
2797 		clear_tv(rettv);
2798 	    }
2799 	    else
2800 		ret = typval_compare(rettv, &var2, type, ic);
2801 	    clear_tv(&var2);
2802 	    return ret;
2803 	}
2804     }
2805 
2806     return OK;
2807 }
2808 
2809 /*
2810  * Make a copy of blob "tv1" and append blob "tv2".
2811  */
2812     void
2813 eval_addblob(typval_T *tv1, typval_T *tv2)
2814 {
2815     blob_T  *b1 = tv1->vval.v_blob;
2816     blob_T  *b2 = tv2->vval.v_blob;
2817     blob_T  *b = blob_alloc();
2818     int	    i;
2819 
2820     if (b != NULL)
2821     {
2822 	for (i = 0; i < blob_len(b1); i++)
2823 	    ga_append(&b->bv_ga, blob_get(b1, i));
2824 	for (i = 0; i < blob_len(b2); i++)
2825 	    ga_append(&b->bv_ga, blob_get(b2, i));
2826 
2827 	clear_tv(tv1);
2828 	rettv_blob_set(tv1, b);
2829     }
2830 }
2831 
2832 /*
2833  * Make a copy of list "tv1" and append list "tv2".
2834  */
2835     int
2836 eval_addlist(typval_T *tv1, typval_T *tv2)
2837 {
2838     typval_T var3;
2839 
2840     // concatenate Lists
2841     if (list_concat(tv1->vval.v_list, tv2->vval.v_list, &var3) == FAIL)
2842     {
2843 	clear_tv(tv1);
2844 	clear_tv(tv2);
2845 	return FAIL;
2846     }
2847     clear_tv(tv1);
2848     *tv1 = var3;
2849     return OK;
2850 }
2851 
2852 /*
2853  * Handle fourth level expression:
2854  *	+	number addition
2855  *	-	number subtraction
2856  *	.	string concatenation (if script version is 1)
2857  *	..	string concatenation
2858  *
2859  * "arg" must point to the first non-white of the expression.
2860  * "arg" is advanced to just after the recognized expression.
2861  *
2862  * Return OK or FAIL.
2863  */
2864     static int
2865 eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2866 {
2867     /*
2868      * Get the first variable.
2869      */
2870     if (eval6(arg, rettv, evalarg, FALSE) == FAIL)
2871 	return FAIL;
2872 
2873     /*
2874      * Repeat computing, until no '+', '-' or '.' is following.
2875      */
2876     for (;;)
2877     {
2878 	int	    evaluate;
2879 	int	    getnext;
2880 	char_u	    *p;
2881 	int	    op;
2882 	int	    oplen;
2883 	int	    concat;
2884 	typval_T    var2;
2885 	int	    vim9script = in_vim9script();
2886 
2887 	// "." is only string concatenation when scriptversion is 1
2888 	// "+=", "-=" and "..=" are assignments
2889 	// "++" and "--" on the next line are a separate command.
2890 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2891 	op = *p;
2892 	concat = op == '.' && (*(p + 1) == '.' || current_sctx.sc_version < 2);
2893 	if ((op != '+' && op != '-' && !concat) || p[1] == '='
2894 					       || (p[1] == '.' && p[2] == '='))
2895 	    break;
2896 	if (getnext && (op == '+' || op == '-') && p[0] == p[1])
2897 	    break;
2898 
2899 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2900 	oplen = (concat && p[1] == '.') ? 2 : 1;
2901 	if (getnext)
2902 	    *arg = eval_next_line(evalarg);
2903 	else
2904 	{
2905 	    if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2906 	    {
2907 		error_white_both(*arg, oplen);
2908 		clear_tv(rettv);
2909 		return FAIL;
2910 	    }
2911 	    *arg = p;
2912 	}
2913 	if ((op != '+' || (rettv->v_type != VAR_LIST
2914 						 && rettv->v_type != VAR_BLOB))
2915 #ifdef FEAT_FLOAT
2916 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2917 #endif
2918 		&& evaluate)
2919 	{
2920 	    int		error = FALSE;
2921 
2922 	    // For "list + ...", an illegal use of the first operand as
2923 	    // a number cannot be determined before evaluating the 2nd
2924 	    // operand: if this is also a list, all is ok.
2925 	    // For "something . ...", "something - ..." or "non-list + ...",
2926 	    // we know that the first operand needs to be a string or number
2927 	    // without evaluating the 2nd operand.  So check before to avoid
2928 	    // side effects after an error.
2929 	    if (op != '.')
2930 		tv_get_number_chk(rettv, &error);
2931 	    if ((op == '.' && tv_get_string_chk(rettv) == NULL) || error)
2932 	    {
2933 		clear_tv(rettv);
2934 		return FAIL;
2935 	    }
2936 	}
2937 
2938 	/*
2939 	 * Get the second variable.
2940 	 */
2941 	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[oplen]))
2942 	{
2943 	    error_white_both(*arg, oplen);
2944 	    clear_tv(rettv);
2945 	    return FAIL;
2946 	}
2947 	*arg = skipwhite_and_linebreak(*arg + oplen, evalarg);
2948 	if (eval6(arg, &var2, evalarg, !vim9script && op == '.') == FAIL)
2949 	{
2950 	    clear_tv(rettv);
2951 	    return FAIL;
2952 	}
2953 
2954 	if (evaluate)
2955 	{
2956 	    /*
2957 	     * Compute the result.
2958 	     */
2959 	    if (op == '.')
2960 	    {
2961 		char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
2962 		char_u	*s1 = tv_get_string_buf(rettv, buf1);
2963 		char_u	*s2 = NULL;
2964 
2965 		if (vim9script && (var2.v_type == VAR_VOID
2966 			|| var2.v_type == VAR_CHANNEL
2967 			|| var2.v_type == VAR_JOB))
2968 		    semsg(_(e_using_invalid_value_as_string_str),
2969 						   vartype_name(var2.v_type));
2970 #ifdef FEAT_FLOAT
2971 		else if (vim9script && var2.v_type == VAR_FLOAT)
2972 		{
2973 		    vim_snprintf((char *)buf2, NUMBUFLEN, "%g",
2974 							    var2.vval.v_float);
2975 		    s2 = buf2;
2976 		}
2977 #endif
2978 		else
2979 		    s2 = tv_get_string_buf_chk(&var2, buf2);
2980 		if (s2 == NULL)		// type error ?
2981 		{
2982 		    clear_tv(rettv);
2983 		    clear_tv(&var2);
2984 		    return FAIL;
2985 		}
2986 		p = concat_str(s1, s2);
2987 		clear_tv(rettv);
2988 		rettv->v_type = VAR_STRING;
2989 		rettv->vval.v_string = p;
2990 	    }
2991 	    else if (op == '+' && rettv->v_type == VAR_BLOB
2992 						   && var2.v_type == VAR_BLOB)
2993 		eval_addblob(rettv, &var2);
2994 	    else if (op == '+' && rettv->v_type == VAR_LIST
2995 						   && var2.v_type == VAR_LIST)
2996 	    {
2997 		if (eval_addlist(rettv, &var2) == FAIL)
2998 		    return FAIL;
2999 	    }
3000 	    else
3001 	    {
3002 		int		error = FALSE;
3003 		varnumber_T	n1, n2;
3004 #ifdef FEAT_FLOAT
3005 		float_T	    f1 = 0, f2 = 0;
3006 
3007 		if (rettv->v_type == VAR_FLOAT)
3008 		{
3009 		    f1 = rettv->vval.v_float;
3010 		    n1 = 0;
3011 		}
3012 		else
3013 #endif
3014 		{
3015 		    n1 = tv_get_number_chk(rettv, &error);
3016 		    if (error)
3017 		    {
3018 			// This can only happen for "list + non-list" or
3019 			// "blob + non-blob".  For "non-list + ..." or
3020 			// "something - ...", we returned before evaluating the
3021 			// 2nd operand.
3022 			clear_tv(rettv);
3023 			clear_tv(&var2);
3024 			return FAIL;
3025 		    }
3026 #ifdef FEAT_FLOAT
3027 		    if (var2.v_type == VAR_FLOAT)
3028 			f1 = n1;
3029 #endif
3030 		}
3031 #ifdef FEAT_FLOAT
3032 		if (var2.v_type == VAR_FLOAT)
3033 		{
3034 		    f2 = var2.vval.v_float;
3035 		    n2 = 0;
3036 		}
3037 		else
3038 #endif
3039 		{
3040 		    n2 = tv_get_number_chk(&var2, &error);
3041 		    if (error)
3042 		    {
3043 			clear_tv(rettv);
3044 			clear_tv(&var2);
3045 			return FAIL;
3046 		    }
3047 #ifdef FEAT_FLOAT
3048 		    if (rettv->v_type == VAR_FLOAT)
3049 			f2 = n2;
3050 #endif
3051 		}
3052 		clear_tv(rettv);
3053 
3054 #ifdef FEAT_FLOAT
3055 		// If there is a float on either side the result is a float.
3056 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3057 		{
3058 		    if (op == '+')
3059 			f1 = f1 + f2;
3060 		    else
3061 			f1 = f1 - f2;
3062 		    rettv->v_type = VAR_FLOAT;
3063 		    rettv->vval.v_float = f1;
3064 		}
3065 		else
3066 #endif
3067 		{
3068 		    if (op == '+')
3069 			n1 = n1 + n2;
3070 		    else
3071 			n1 = n1 - n2;
3072 		    rettv->v_type = VAR_NUMBER;
3073 		    rettv->vval.v_number = n1;
3074 		}
3075 	    }
3076 	    clear_tv(&var2);
3077 	}
3078     }
3079     return OK;
3080 }
3081 
3082 /*
3083  * Handle fifth level expression:
3084  *	*	number multiplication
3085  *	/	number division
3086  *	%	number modulo
3087  *
3088  * "arg" must point to the first non-white of the expression.
3089  * "arg" is advanced to just after the recognized expression.
3090  *
3091  * Return OK or FAIL.
3092  */
3093     static int
3094 eval6(
3095     char_u	**arg,
3096     typval_T	*rettv,
3097     evalarg_T	*evalarg,
3098     int		want_string)  // after "." operator
3099 {
3100 #ifdef FEAT_FLOAT
3101     int	    use_float = FALSE;
3102 #endif
3103 
3104     /*
3105      * Get the first variable.
3106      */
3107     if (eval7t(arg, rettv, evalarg, want_string) == FAIL)
3108 	return FAIL;
3109 
3110     /*
3111      * Repeat computing, until no '*', '/' or '%' is following.
3112      */
3113     for (;;)
3114     {
3115 	int	    evaluate;
3116 	int	    getnext;
3117 	typval_T    var2;
3118 	char_u	    *p;
3119 	int	    op;
3120 	varnumber_T n1, n2;
3121 #ifdef FEAT_FLOAT
3122 	float_T	    f1, f2;
3123 #endif
3124 	int	    error;
3125 
3126 	// "*=", "/=" and "%=" are assignments
3127 	p = eval_next_non_blank(*arg, evalarg, &getnext);
3128 	op = *p;
3129 	if ((op != '*' && op != '/' && op != '%') || p[1] == '=')
3130 	    break;
3131 
3132 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
3133 	if (getnext)
3134 	    *arg = eval_next_line(evalarg);
3135 	else
3136 	{
3137 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(**arg))
3138 	    {
3139 		error_white_both(*arg, 1);
3140 		clear_tv(rettv);
3141 		return FAIL;
3142 	    }
3143 	    *arg = p;
3144 	}
3145 
3146 #ifdef FEAT_FLOAT
3147 	f1 = 0;
3148 	f2 = 0;
3149 #endif
3150 	error = FALSE;
3151 	if (evaluate)
3152 	{
3153 #ifdef FEAT_FLOAT
3154 	    if (rettv->v_type == VAR_FLOAT)
3155 	    {
3156 		f1 = rettv->vval.v_float;
3157 		use_float = TRUE;
3158 		n1 = 0;
3159 	    }
3160 	    else
3161 #endif
3162 		n1 = tv_get_number_chk(rettv, &error);
3163 	    clear_tv(rettv);
3164 	    if (error)
3165 		return FAIL;
3166 	}
3167 	else
3168 	    n1 = 0;
3169 
3170 	/*
3171 	 * Get the second variable.
3172 	 */
3173 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[1]))
3174 	{
3175 	    error_white_both(*arg, 1);
3176 	    clear_tv(rettv);
3177 	    return FAIL;
3178 	}
3179 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3180 	if (eval7t(arg, &var2, evalarg, FALSE) == FAIL)
3181 	    return FAIL;
3182 
3183 	if (evaluate)
3184 	{
3185 #ifdef FEAT_FLOAT
3186 	    if (var2.v_type == VAR_FLOAT)
3187 	    {
3188 		if (!use_float)
3189 		{
3190 		    f1 = n1;
3191 		    use_float = TRUE;
3192 		}
3193 		f2 = var2.vval.v_float;
3194 		n2 = 0;
3195 	    }
3196 	    else
3197 #endif
3198 	    {
3199 		n2 = tv_get_number_chk(&var2, &error);
3200 		clear_tv(&var2);
3201 		if (error)
3202 		    return FAIL;
3203 #ifdef FEAT_FLOAT
3204 		if (use_float)
3205 		    f2 = n2;
3206 #endif
3207 	    }
3208 
3209 	    /*
3210 	     * Compute the result.
3211 	     * When either side is a float the result is a float.
3212 	     */
3213 #ifdef FEAT_FLOAT
3214 	    if (use_float)
3215 	    {
3216 		if (op == '*')
3217 		    f1 = f1 * f2;
3218 		else if (op == '/')
3219 		{
3220 # ifdef VMS
3221 		    // VMS crashes on divide by zero, work around it
3222 		    if (f2 == 0.0)
3223 		    {
3224 			if (f1 == 0)
3225 			    f1 = -1 * __F_FLT_MAX - 1L;   // similar to NaN
3226 			else if (f1 < 0)
3227 			    f1 = -1 * __F_FLT_MAX;
3228 			else
3229 			    f1 = __F_FLT_MAX;
3230 		    }
3231 		    else
3232 			f1 = f1 / f2;
3233 # else
3234 		    // We rely on the floating point library to handle divide
3235 		    // by zero to result in "inf" and not a crash.
3236 		    f1 = f1 / f2;
3237 # endif
3238 		}
3239 		else
3240 		{
3241 		    emsg(_(e_modulus));
3242 		    return FAIL;
3243 		}
3244 		rettv->v_type = VAR_FLOAT;
3245 		rettv->vval.v_float = f1;
3246 	    }
3247 	    else
3248 #endif
3249 	    {
3250 		int	    failed = FALSE;
3251 
3252 		if (op == '*')
3253 		    n1 = n1 * n2;
3254 		else if (op == '/')
3255 		    n1 = num_divide(n1, n2, &failed);
3256 		else
3257 		    n1 = num_modulus(n1, n2, &failed);
3258 		if (failed)
3259 		    return FAIL;
3260 
3261 		rettv->v_type = VAR_NUMBER;
3262 		rettv->vval.v_number = n1;
3263 	    }
3264 	}
3265     }
3266 
3267     return OK;
3268 }
3269 
3270 /*
3271  * Handle a type cast before a base level expression.
3272  * "arg" must point to the first non-white of the expression.
3273  * "arg" is advanced to just after the recognized expression.
3274  * Return OK or FAIL.
3275  */
3276     static int
3277 eval7t(
3278     char_u	**arg,
3279     typval_T	*rettv,
3280     evalarg_T	*evalarg,
3281     int		want_string)	// after "." operator
3282 {
3283     type_T	*want_type = NULL;
3284     garray_T	type_list;	    // list of pointers to allocated types
3285     int		res;
3286     int		evaluate = evalarg == NULL ? 0
3287 				       : (evalarg->eval_flags & EVAL_EVALUATE);
3288 
3289     // Recognize <type> in Vim9 script only.
3290     if (in_vim9script() && **arg == '<' && eval_isnamec1((*arg)[1]))
3291     {
3292 	++*arg;
3293 	ga_init2(&type_list, sizeof(type_T *), 10);
3294 	want_type = parse_type(arg, &type_list, TRUE);
3295 	if (want_type == NULL && (evaluate || **arg != '>'))
3296 	{
3297 	    clear_type_list(&type_list);
3298 	    return FAIL;
3299 	}
3300 
3301 	if (**arg != '>')
3302 	{
3303 	    if (*skipwhite(*arg) == '>')
3304 		semsg(_(e_no_white_space_allowed_before_str_str), ">", *arg);
3305 	    else
3306 		emsg(_(e_missing_gt));
3307 	    clear_type_list(&type_list);
3308 	    return FAIL;
3309 	}
3310 	++*arg;
3311 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3312     }
3313 
3314     res = eval7(arg, rettv, evalarg, want_string);
3315 
3316     if (want_type != NULL && evaluate)
3317     {
3318 	if (res == OK)
3319 	{
3320 	    type_T *actual = typval2type(rettv, get_copyID(), &type_list, TRUE);
3321 
3322 	    if (!equal_type(want_type, actual))
3323 	    {
3324 		if (want_type == &t_bool && actual != &t_bool
3325 					&& (actual->tt_flags & TTFLAG_BOOL_OK))
3326 		{
3327 		    int n = tv2bool(rettv);
3328 
3329 		    // can use "0" and "1" for boolean in some places
3330 		    clear_tv(rettv);
3331 		    rettv->v_type = VAR_BOOL;
3332 		    rettv->vval.v_number = n ? VVAL_TRUE : VVAL_FALSE;
3333 		}
3334 		else
3335 		{
3336 		    where_T where;
3337 
3338 		    where.wt_index = 0;
3339 		    where.wt_variable = TRUE;
3340 		    res = check_type(want_type, actual, TRUE, where);
3341 		}
3342 	    }
3343 	}
3344 	clear_type_list(&type_list);
3345     }
3346 
3347     return res;
3348 }
3349 
3350     int
3351 eval_leader(char_u **arg, int vim9)
3352 {
3353     char_u	*s = *arg;
3354     char_u	*p = *arg;
3355 
3356     while (*p == '!' || *p == '-' || *p == '+')
3357     {
3358 	char_u *n = skipwhite(p + 1);
3359 
3360 	// ++, --, -+ and +- are not accepted in Vim9 script
3361 	if (vim9 && (*p == '-' || *p == '+') && (*n == '-' || *n == '+'))
3362 	{
3363 	    semsg(_(e_invexpr2), s);
3364 	    return FAIL;
3365 	}
3366 	p = n;
3367     }
3368     *arg = p;
3369     return OK;
3370 }
3371 
3372 /*
3373  * Handle sixth level expression:
3374  *  number		number constant
3375  *  0zFFFFFFFF		Blob constant
3376  *  "string"		string constant
3377  *  'string'		literal string constant
3378  *  &option-name	option value
3379  *  @r			register contents
3380  *  identifier		variable value
3381  *  function()		function call
3382  *  $VAR		environment variable
3383  *  (expression)	nested expression
3384  *  [expr, expr]	List
3385  *  {arg, arg -> expr}	Lambda
3386  *  {key: val, key: val}   Dictionary
3387  *  #{key: val, key: val}  Dictionary with literal keys
3388  *
3389  *  Also handle:
3390  *  ! in front		logical NOT
3391  *  - in front		unary minus
3392  *  + in front		unary plus (ignored)
3393  *  trailing []		subscript in String or List
3394  *  trailing .name	entry in Dictionary
3395  *  trailing ->name()	method call
3396  *
3397  * "arg" must point to the first non-white of the expression.
3398  * "arg" is advanced to just after the recognized expression.
3399  *
3400  * Return OK or FAIL.
3401  */
3402     static int
3403 eval7(
3404     char_u	**arg,
3405     typval_T	*rettv,
3406     evalarg_T	*evalarg,
3407     int		want_string)	// after "." operator
3408 {
3409     int		evaluate = evalarg != NULL
3410 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3411     int		len;
3412     char_u	*s;
3413     char_u	*start_leader, *end_leader;
3414     int		ret = OK;
3415     char_u	*alias;
3416 
3417     /*
3418      * Initialise variable so that clear_tv() can't mistake this for a
3419      * string and free a string that isn't there.
3420      */
3421     rettv->v_type = VAR_UNKNOWN;
3422 
3423     /*
3424      * Skip '!', '-' and '+' characters.  They are handled later.
3425      */
3426     start_leader = *arg;
3427     if (eval_leader(arg, in_vim9script()) == FAIL)
3428 	return FAIL;
3429     end_leader = *arg;
3430 
3431     if (**arg == '.' && (!isdigit(*(*arg + 1))
3432 #ifdef FEAT_FLOAT
3433 	    || current_sctx.sc_version < 2
3434 #endif
3435 	    ))
3436     {
3437 	semsg(_(e_invexpr2), *arg);
3438 	++*arg;
3439 	return FAIL;
3440     }
3441 
3442     switch (**arg)
3443     {
3444     /*
3445      * Number constant.
3446      */
3447     case '0':
3448     case '1':
3449     case '2':
3450     case '3':
3451     case '4':
3452     case '5':
3453     case '6':
3454     case '7':
3455     case '8':
3456     case '9':
3457     case '.':	ret = eval_number(arg, rettv, evaluate, want_string);
3458 
3459 		// Apply prefixed "-" and "+" now.  Matters especially when
3460 		// "->" follows.
3461 		if (ret == OK && evaluate && end_leader > start_leader
3462 						  && rettv->v_type != VAR_BLOB)
3463 		    ret = eval7_leader(rettv, TRUE, start_leader, &end_leader);
3464 		break;
3465 
3466     /*
3467      * String constant: "string".
3468      */
3469     case '"':	ret = eval_string(arg, rettv, evaluate);
3470 		break;
3471 
3472     /*
3473      * Literal string constant: 'str''ing'.
3474      */
3475     case '\'':	ret = eval_lit_string(arg, rettv, evaluate);
3476 		break;
3477 
3478     /*
3479      * List: [expr, expr]
3480      */
3481     case '[':	ret = eval_list(arg, rettv, evalarg, TRUE);
3482 		break;
3483 
3484     /*
3485      * Dictionary: #{key: val, key: val}
3486      */
3487     case '#':	if (in_vim9script())
3488 		{
3489 		    ret = vim9_bad_comment(*arg) ? FAIL : NOTDONE;
3490 		}
3491 		else if ((*arg)[1] == '{')
3492 		{
3493 		    ++*arg;
3494 		    ret = eval_dict(arg, rettv, evalarg, TRUE);
3495 		}
3496 		else
3497 		    ret = NOTDONE;
3498 		break;
3499 
3500     /*
3501      * Lambda: {arg, arg -> expr}
3502      * Dictionary: {'key': val, 'key': val}
3503      */
3504     case '{':	if (in_vim9script())
3505 		    ret = NOTDONE;
3506 		else
3507 		    ret = get_lambda_tv(arg, rettv, in_vim9script(), evalarg);
3508 		if (ret == NOTDONE)
3509 		    ret = eval_dict(arg, rettv, evalarg, FALSE);
3510 		break;
3511 
3512     /*
3513      * Option value: &name
3514      */
3515     case '&':	ret = eval_option(arg, rettv, evaluate);
3516 		break;
3517 
3518     /*
3519      * Environment variable: $VAR.
3520      */
3521     case '$':	ret = eval_env_var(arg, rettv, evaluate);
3522 		break;
3523 
3524     /*
3525      * Register contents: @r.
3526      */
3527     case '@':	++*arg;
3528 		if (evaluate)
3529 		{
3530 		    if (in_vim9script() && IS_WHITE_OR_NUL(**arg))
3531 			semsg(_(e_syntax_error_at_str), *arg);
3532 		    else if (in_vim9script() && !valid_yank_reg(**arg, FALSE))
3533 			emsg_invreg(**arg);
3534 		    else
3535 		    {
3536 			rettv->v_type = VAR_STRING;
3537 			rettv->vval.v_string = get_reg_contents(**arg,
3538 								GREG_EXPR_SRC);
3539 		    }
3540 		}
3541 		if (**arg != NUL)
3542 		    ++*arg;
3543 		break;
3544 
3545     /*
3546      * nested expression: (expression).
3547      * or lambda: (arg) => expr
3548      */
3549     case '(':	ret = NOTDONE;
3550 		if (in_vim9script())
3551 		{
3552 		    ret = get_lambda_tv(arg, rettv, TRUE, evalarg);
3553 		    if (ret == OK && evaluate)
3554 		    {
3555 			ufunc_T *ufunc = rettv->vval.v_partial->pt_func;
3556 
3557 			// compile it here to get the return type
3558 			if (compile_def_function(ufunc,
3559 					 TRUE, PROFILING(ufunc), NULL) == FAIL)
3560 			{
3561 			    clear_tv(rettv);
3562 			    ret = FAIL;
3563 			}
3564 		    }
3565 		}
3566 		if (ret == NOTDONE)
3567 		{
3568 		    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3569 		    ret = eval1(arg, rettv, evalarg);	// recursive!
3570 
3571 		    *arg = skipwhite_and_linebreak(*arg, evalarg);
3572 		    if (**arg == ')')
3573 			++*arg;
3574 		    else if (ret == OK)
3575 		    {
3576 			emsg(_(e_missing_close));
3577 			clear_tv(rettv);
3578 			ret = FAIL;
3579 		    }
3580 		}
3581 		break;
3582 
3583     default:	ret = NOTDONE;
3584 		break;
3585     }
3586 
3587     if (ret == NOTDONE)
3588     {
3589 	/*
3590 	 * Must be a variable or function name.
3591 	 * Can also be a curly-braces kind of name: {expr}.
3592 	 */
3593 	s = *arg;
3594 	len = get_name_len(arg, &alias, evaluate, TRUE);
3595 	if (alias != NULL)
3596 	    s = alias;
3597 
3598 	if (len <= 0)
3599 	    ret = FAIL;
3600 	else
3601 	{
3602 	    int	    flags = evalarg == NULL ? 0 : evalarg->eval_flags;
3603 
3604 	    if (evaluate && in_vim9script() && len == 1 && *s == '_')
3605 	    {
3606 		emsg(_(e_cannot_use_underscore_here));
3607 		ret = FAIL;
3608 	    }
3609 	    else if ((in_vim9script() ? **arg : *skipwhite(*arg)) == '(')
3610 	    {
3611 		// "name(..."  recursive!
3612 		*arg = skipwhite(*arg);
3613 		ret = eval_func(arg, evalarg, s, len, rettv, flags, NULL);
3614 	    }
3615 	    else if (flags & EVAL_CONSTANT)
3616 		ret = FAIL;
3617 	    else if (evaluate)
3618 	    {
3619 		// get the value of "true", "false" or a variable
3620 		if (len == 4 && in_vim9script() && STRNCMP(s, "true", 4) == 0)
3621 		{
3622 		    rettv->v_type = VAR_BOOL;
3623 		    rettv->vval.v_number = VVAL_TRUE;
3624 		    ret = OK;
3625 		}
3626 		else if (len == 5 && in_vim9script()
3627 						&& STRNCMP(s, "false", 5) == 0)
3628 		{
3629 		    rettv->v_type = VAR_BOOL;
3630 		    rettv->vval.v_number = VVAL_FALSE;
3631 		    ret = OK;
3632 		}
3633 		else if (len == 4 && in_vim9script()
3634 						&& STRNCMP(s, "null", 4) == 0)
3635 		{
3636 		    rettv->v_type = VAR_SPECIAL;
3637 		    rettv->vval.v_number = VVAL_NULL;
3638 		    ret = OK;
3639 		}
3640 		else
3641 		    ret = eval_variable(s, len, rettv, NULL,
3642 					   EVAL_VAR_VERBOSE + EVAL_VAR_IMPORT);
3643 	    }
3644 	    else
3645 	    {
3646 		// skip the name
3647 		check_vars(s, len);
3648 		ret = OK;
3649 	    }
3650 	}
3651 	vim_free(alias);
3652     }
3653 
3654     // Handle following '[', '(' and '.' for expr[expr], expr.name,
3655     // expr(expr), expr->name(expr)
3656     if (ret == OK)
3657 	ret = handle_subscript(arg, rettv, evalarg, TRUE);
3658 
3659     /*
3660      * Apply logical NOT and unary '-', from right to left, ignore '+'.
3661      */
3662     if (ret == OK && evaluate && end_leader > start_leader)
3663 	ret = eval7_leader(rettv, FALSE, start_leader, &end_leader);
3664     return ret;
3665 }
3666 
3667 /*
3668  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
3669  * When "numeric_only" is TRUE only handle "+" and "-".
3670  * Adjusts "end_leaderp" until it is at "start_leader".
3671  */
3672     static int
3673 eval7_leader(
3674 	typval_T    *rettv,
3675 	int	    numeric_only,
3676 	char_u	    *start_leader,
3677 	char_u	    **end_leaderp)
3678 {
3679     char_u	*end_leader = *end_leaderp;
3680     int		ret = OK;
3681     int		error = FALSE;
3682     varnumber_T val = 0;
3683     vartype_T	type = rettv->v_type;
3684 #ifdef FEAT_FLOAT
3685     float_T	    f = 0.0;
3686 
3687     if (rettv->v_type == VAR_FLOAT)
3688 	f = rettv->vval.v_float;
3689     else
3690 #endif
3691     {
3692 	while (VIM_ISWHITE(end_leader[-1]))
3693 	    --end_leader;
3694 	if (in_vim9script() && end_leader[-1] == '!')
3695 	    val = tv2bool(rettv);
3696 	else
3697 	    val = tv_get_number_chk(rettv, &error);
3698     }
3699     if (error)
3700     {
3701 	clear_tv(rettv);
3702 	ret = FAIL;
3703     }
3704     else
3705     {
3706 	while (end_leader > start_leader)
3707 	{
3708 	    --end_leader;
3709 	    if (*end_leader == '!')
3710 	    {
3711 		if (numeric_only)
3712 		{
3713 		    ++end_leader;
3714 		    break;
3715 		}
3716 #ifdef FEAT_FLOAT
3717 		if (rettv->v_type == VAR_FLOAT)
3718 		{
3719 		    if (in_vim9script())
3720 		    {
3721 			rettv->v_type = VAR_BOOL;
3722 			val = f == 0.0 ? VVAL_TRUE : VVAL_FALSE;
3723 		    }
3724 		    else
3725 			f = !f;
3726 		}
3727 		else
3728 #endif
3729 		{
3730 		    val = !val;
3731 		    type = VAR_BOOL;
3732 		}
3733 	    }
3734 	    else if (*end_leader == '-')
3735 	    {
3736 #ifdef FEAT_FLOAT
3737 		if (rettv->v_type == VAR_FLOAT)
3738 		    f = -f;
3739 		else
3740 #endif
3741 		{
3742 		    val = -val;
3743 		    type = VAR_NUMBER;
3744 		}
3745 	    }
3746 	}
3747 #ifdef FEAT_FLOAT
3748 	if (rettv->v_type == VAR_FLOAT)
3749 	{
3750 	    clear_tv(rettv);
3751 	    rettv->vval.v_float = f;
3752 	}
3753 	else
3754 #endif
3755 	{
3756 	    clear_tv(rettv);
3757 	    if (in_vim9script())
3758 		rettv->v_type = type;
3759 	    else
3760 		rettv->v_type = VAR_NUMBER;
3761 	    rettv->vval.v_number = val;
3762 	}
3763     }
3764     *end_leaderp = end_leader;
3765     return ret;
3766 }
3767 
3768 /*
3769  * Call the function referred to in "rettv".
3770  */
3771     static int
3772 call_func_rettv(
3773 	char_u	    **arg,
3774 	evalarg_T   *evalarg,
3775 	typval_T    *rettv,
3776 	int	    evaluate,
3777 	dict_T	    *selfdict,
3778 	typval_T    *basetv)
3779 {
3780     partial_T	*pt = NULL;
3781     funcexe_T	funcexe;
3782     typval_T	functv;
3783     char_u	*s;
3784     int		ret;
3785 
3786     // need to copy the funcref so that we can clear rettv
3787     if (evaluate)
3788     {
3789 	functv = *rettv;
3790 	rettv->v_type = VAR_UNKNOWN;
3791 
3792 	// Invoke the function.  Recursive!
3793 	if (functv.v_type == VAR_PARTIAL)
3794 	{
3795 	    pt = functv.vval.v_partial;
3796 	    s = partial_name(pt);
3797 	}
3798 	else
3799 	    s = functv.vval.v_string;
3800     }
3801     else
3802 	s = (char_u *)"";
3803 
3804     CLEAR_FIELD(funcexe);
3805     funcexe.firstline = curwin->w_cursor.lnum;
3806     funcexe.lastline = curwin->w_cursor.lnum;
3807     funcexe.evaluate = evaluate;
3808     funcexe.partial = pt;
3809     funcexe.selfdict = selfdict;
3810     funcexe.basetv = basetv;
3811     ret = get_func_tv(s, -1, rettv, arg, evalarg, &funcexe);
3812 
3813     // Clear the funcref afterwards, so that deleting it while
3814     // evaluating the arguments is possible (see test55).
3815     if (evaluate)
3816 	clear_tv(&functv);
3817 
3818     return ret;
3819 }
3820 
3821 /*
3822  * Evaluate "->method()".
3823  * "*arg" points to "method".
3824  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3825  */
3826     static int
3827 eval_lambda(
3828     char_u	**arg,
3829     typval_T	*rettv,
3830     evalarg_T	*evalarg,
3831     int		verbose)	// give error messages
3832 {
3833     int		evaluate = evalarg != NULL
3834 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3835     typval_T	base = *rettv;
3836     int		ret;
3837 
3838     rettv->v_type = VAR_UNKNOWN;
3839 
3840     if (**arg == '{')
3841     {
3842 	// ->{lambda}()
3843 	ret = get_lambda_tv(arg, rettv, FALSE, evalarg);
3844     }
3845     else
3846     {
3847 	// ->(lambda)()
3848 	++*arg;
3849 	ret = eval1(arg, rettv, evalarg);
3850 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3851 	if (**arg != ')')
3852 	{
3853 	    emsg(_(e_missing_close));
3854 	    ret = FAIL;
3855 	}
3856 	++*arg;
3857     }
3858     if (ret != OK)
3859 	return FAIL;
3860     else if (**arg != '(')
3861     {
3862 	if (verbose)
3863 	{
3864 	    if (*skipwhite(*arg) == '(')
3865 		emsg(_(e_nowhitespace));
3866 	    else
3867 		semsg(_(e_missing_paren), "lambda");
3868 	}
3869 	clear_tv(rettv);
3870 	ret = FAIL;
3871     }
3872     else
3873 	ret = call_func_rettv(arg, evalarg, rettv, evaluate, NULL, &base);
3874 
3875     // Clear the funcref afterwards, so that deleting it while
3876     // evaluating the arguments is possible (see test55).
3877     if (evaluate)
3878 	clear_tv(&base);
3879 
3880     return ret;
3881 }
3882 
3883 /*
3884  * Evaluate "->method()".
3885  * "*arg" points to "method".
3886  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3887  */
3888     static int
3889 eval_method(
3890     char_u	**arg,
3891     typval_T	*rettv,
3892     evalarg_T	*evalarg,
3893     int		verbose)	// give error messages
3894 {
3895     char_u	*name;
3896     long	len;
3897     char_u	*alias;
3898     typval_T	base = *rettv;
3899     int		ret;
3900     int		evaluate = evalarg != NULL
3901 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3902 
3903     rettv->v_type = VAR_UNKNOWN;
3904 
3905     name = *arg;
3906     len = get_name_len(arg, &alias, evaluate, TRUE);
3907     if (alias != NULL)
3908 	name = alias;
3909 
3910     if (len <= 0)
3911     {
3912 	if (verbose)
3913 	    emsg(_("E260: Missing name after ->"));
3914 	ret = FAIL;
3915     }
3916     else
3917     {
3918 	*arg = skipwhite(*arg);
3919 	if (**arg != '(')
3920 	{
3921 	    if (verbose)
3922 		semsg(_(e_missing_paren), name);
3923 	    ret = FAIL;
3924 	}
3925 	else if (VIM_ISWHITE((*arg)[-1]))
3926 	{
3927 	    if (verbose)
3928 		emsg(_(e_nowhitespace));
3929 	    ret = FAIL;
3930 	}
3931 	else
3932 	    ret = eval_func(arg, evalarg, name, len, rettv,
3933 					  evaluate ? EVAL_EVALUATE : 0, &base);
3934     }
3935 
3936     // Clear the funcref afterwards, so that deleting it while
3937     // evaluating the arguments is possible (see test55).
3938     if (evaluate)
3939 	clear_tv(&base);
3940 
3941     return ret;
3942 }
3943 
3944 /*
3945  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
3946  * "*arg" points to the '[' or '.'.
3947  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
3948  */
3949     static int
3950 eval_index(
3951     char_u	**arg,
3952     typval_T	*rettv,
3953     evalarg_T	*evalarg,
3954     int		verbose)	// give error messages
3955 {
3956     int		evaluate = evalarg != NULL
3957 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3958     int		empty1 = FALSE, empty2 = FALSE;
3959     typval_T	var1, var2;
3960     int		range = FALSE;
3961     char_u	*key = NULL;
3962     int		keylen = -1;
3963     int		vim9 = in_vim9script();
3964 
3965     if (check_can_index(rettv, evaluate, verbose) == FAIL)
3966 	return FAIL;
3967 
3968     init_tv(&var1);
3969     init_tv(&var2);
3970     if (**arg == '.')
3971     {
3972 	/*
3973 	 * dict.name
3974 	 */
3975 	key = *arg + 1;
3976 	for (keylen = 0; eval_isdictc(key[keylen]); ++keylen)
3977 	    ;
3978 	if (keylen == 0)
3979 	    return FAIL;
3980 	*arg = key + keylen;
3981     }
3982     else
3983     {
3984 	/*
3985 	 * something[idx]
3986 	 *
3987 	 * Get the (first) variable from inside the [].
3988 	 */
3989 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3990 	if (**arg == ':')
3991 	    empty1 = TRUE;
3992 	else if (eval1(arg, &var1, evalarg) == FAIL)	// recursive!
3993 	    return FAIL;
3994 	else if (vim9 && **arg == ':')
3995 	{
3996 	    semsg(_(e_white_space_required_before_and_after_str_at_str),
3997 								    ":", *arg);
3998 	    clear_tv(&var1);
3999 	    return FAIL;
4000 	}
4001 	else if (evaluate)
4002 	{
4003 #ifdef FEAT_FLOAT
4004 	    // allow for indexing with float
4005 	    if (vim9 && rettv->v_type == VAR_DICT
4006 						   && var1.v_type == VAR_FLOAT)
4007 	    {
4008 		var1.vval.v_string = typval_tostring(&var1, TRUE);
4009 		var1.v_type = VAR_STRING;
4010 	    }
4011 #endif
4012 	    if (tv_get_string_chk(&var1) == NULL)
4013 	    {
4014 		// not a number or string
4015 		clear_tv(&var1);
4016 		return FAIL;
4017 	    }
4018 	}
4019 
4020 	/*
4021 	 * Get the second variable from inside the [:].
4022 	 */
4023 	*arg = skipwhite_and_linebreak(*arg, evalarg);
4024 	if (**arg == ':')
4025 	{
4026 	    range = TRUE;
4027 	    ++*arg;
4028 	    if (vim9 && !IS_WHITE_OR_NUL(**arg) && **arg != ']')
4029 	    {
4030 		semsg(_(e_white_space_required_before_and_after_str_at_str),
4031 								":", *arg - 1);
4032 		if (!empty1)
4033 		    clear_tv(&var1);
4034 		return FAIL;
4035 	    }
4036 	    *arg = skipwhite_and_linebreak(*arg, evalarg);
4037 	    if (**arg == ']')
4038 		empty2 = TRUE;
4039 	    else if (eval1(arg, &var2, evalarg) == FAIL)	// recursive!
4040 	    {
4041 		if (!empty1)
4042 		    clear_tv(&var1);
4043 		return FAIL;
4044 	    }
4045 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
4046 	    {
4047 		// not a number or string
4048 		if (!empty1)
4049 		    clear_tv(&var1);
4050 		clear_tv(&var2);
4051 		return FAIL;
4052 	    }
4053 	}
4054 
4055 	// Check for the ']'.
4056 	*arg = skipwhite_and_linebreak(*arg, evalarg);
4057 	if (**arg != ']')
4058 	{
4059 	    if (verbose)
4060 		emsg(_(e_missbrac));
4061 	    clear_tv(&var1);
4062 	    if (range)
4063 		clear_tv(&var2);
4064 	    return FAIL;
4065 	}
4066 	*arg = *arg + 1;	// skip over the ']'
4067     }
4068 
4069     if (evaluate)
4070     {
4071 	int res = eval_index_inner(rettv, range,
4072 		empty1 ? NULL : &var1, empty2 ? NULL : &var2, FALSE,
4073 		key, keylen, verbose);
4074 
4075 	if (!empty1)
4076 	    clear_tv(&var1);
4077 	if (range)
4078 	    clear_tv(&var2);
4079 	return res;
4080     }
4081     return OK;
4082 }
4083 
4084 /*
4085  * Check if "rettv" can have an [index] or [sli:ce]
4086  */
4087     int
4088 check_can_index(typval_T *rettv, int evaluate, int verbose)
4089 {
4090     switch (rettv->v_type)
4091     {
4092 	case VAR_FUNC:
4093 	case VAR_PARTIAL:
4094 	    if (verbose)
4095 		emsg(_("E695: Cannot index a Funcref"));
4096 	    return FAIL;
4097 	case VAR_FLOAT:
4098 #ifdef FEAT_FLOAT
4099 	    if (verbose)
4100 		emsg(_(e_float_as_string));
4101 	    return FAIL;
4102 #endif
4103 	case VAR_BOOL:
4104 	case VAR_SPECIAL:
4105 	case VAR_JOB:
4106 	case VAR_CHANNEL:
4107 	case VAR_INSTR:
4108 	    if (verbose)
4109 		emsg(_(e_cannot_index_special_variable));
4110 	    return FAIL;
4111 	case VAR_UNKNOWN:
4112 	case VAR_ANY:
4113 	case VAR_VOID:
4114 	    if (evaluate)
4115 	    {
4116 		emsg(_(e_cannot_index_special_variable));
4117 		return FAIL;
4118 	    }
4119 	    // FALLTHROUGH
4120 
4121 	case VAR_STRING:
4122 	case VAR_LIST:
4123 	case VAR_DICT:
4124 	case VAR_BLOB:
4125 	    break;
4126 	case VAR_NUMBER:
4127 	    if (in_vim9script())
4128 		emsg(_(e_cannot_index_number));
4129 	    break;
4130     }
4131     return OK;
4132 }
4133 
4134 /*
4135  * slice() function
4136  */
4137     void
4138 f_slice(typval_T *argvars, typval_T *rettv)
4139 {
4140     if (check_can_index(argvars, TRUE, FALSE) == OK)
4141     {
4142 	copy_tv(argvars, rettv);
4143 	eval_index_inner(rettv, TRUE, argvars + 1,
4144 		argvars[2].v_type == VAR_UNKNOWN ? NULL : argvars + 2,
4145 		TRUE, NULL, 0, FALSE);
4146     }
4147 }
4148 
4149 /*
4150  * Apply index or range to "rettv".
4151  * "var1" is the first index, NULL for [:expr].
4152  * "var2" is the second index, NULL for [expr] and [expr: ]
4153  * "exclusive" is TRUE for slice(): second index is exclusive, use character
4154  * index for string.
4155  * Alternatively, "key" is not NULL, then key[keylen] is the dict index.
4156  */
4157     int
4158 eval_index_inner(
4159 	typval_T    *rettv,
4160 	int	    is_range,
4161 	typval_T    *var1,
4162 	typval_T    *var2,
4163 	int	    exclusive,
4164 	char_u	    *key,
4165 	int	    keylen,
4166 	int	    verbose)
4167 {
4168     varnumber_T	    n1, n2 = 0;
4169     long	    len;
4170 
4171     n1 = 0;
4172     if (var1 != NULL && rettv->v_type != VAR_DICT)
4173 	n1 = tv_get_number(var1);
4174 
4175     if (is_range)
4176     {
4177 	if (rettv->v_type == VAR_DICT)
4178 	{
4179 	    if (verbose)
4180 		emsg(_(e_cannot_slice_dictionary));
4181 	    return FAIL;
4182 	}
4183 	if (var2 != NULL)
4184 	    n2 = tv_get_number(var2);
4185 	else
4186 	    n2 = VARNUM_MAX;
4187     }
4188 
4189     switch (rettv->v_type)
4190     {
4191 	case VAR_UNKNOWN:
4192 	case VAR_ANY:
4193 	case VAR_VOID:
4194 	case VAR_FUNC:
4195 	case VAR_PARTIAL:
4196 	case VAR_FLOAT:
4197 	case VAR_BOOL:
4198 	case VAR_SPECIAL:
4199 	case VAR_JOB:
4200 	case VAR_CHANNEL:
4201 	case VAR_INSTR:
4202 	    break; // not evaluating, skipping over subscript
4203 
4204 	case VAR_NUMBER:
4205 	case VAR_STRING:
4206 	    {
4207 		char_u	*s = tv_get_string(rettv);
4208 
4209 		len = (long)STRLEN(s);
4210 		if (in_vim9script() || exclusive)
4211 		{
4212 		    if (is_range)
4213 			s = string_slice(s, n1, n2, exclusive);
4214 		    else
4215 			s = char_from_string(s, n1);
4216 		}
4217 		else if (is_range)
4218 		{
4219 		    // The resulting variable is a substring.  If the indexes
4220 		    // are out of range the result is empty.
4221 		    if (n1 < 0)
4222 		    {
4223 			n1 = len + n1;
4224 			if (n1 < 0)
4225 			    n1 = 0;
4226 		    }
4227 		    if (n2 < 0)
4228 			n2 = len + n2;
4229 		    else if (n2 >= len)
4230 			n2 = len;
4231 		    if (n1 >= len || n2 < 0 || n1 > n2)
4232 			s = NULL;
4233 		    else
4234 			s = vim_strnsave(s + n1, n2 - n1 + 1);
4235 		}
4236 		else
4237 		{
4238 		    // The resulting variable is a string of a single
4239 		    // character.  If the index is too big or negative the
4240 		    // result is empty.
4241 		    if (n1 >= len || n1 < 0)
4242 			s = NULL;
4243 		    else
4244 			s = vim_strnsave(s + n1, 1);
4245 		}
4246 		clear_tv(rettv);
4247 		rettv->v_type = VAR_STRING;
4248 		rettv->vval.v_string = s;
4249 	    }
4250 	    break;
4251 
4252 	case VAR_BLOB:
4253 	    blob_slice_or_index(rettv->vval.v_blob, is_range, n1, n2,
4254 							     exclusive, rettv);
4255 	    break;
4256 
4257 	case VAR_LIST:
4258 	    if (var1 == NULL)
4259 		n1 = 0;
4260 	    if (var2 == NULL)
4261 		n2 = VARNUM_MAX;
4262 	    if (list_slice_or_index(rettv->vval.v_list,
4263 			  is_range, n1, n2, exclusive, rettv, verbose) == FAIL)
4264 		return FAIL;
4265 	    break;
4266 
4267 	case VAR_DICT:
4268 	    {
4269 		dictitem_T	*item;
4270 		typval_T	tmp;
4271 
4272 		if (key == NULL)
4273 		{
4274 		    key = tv_get_string_chk(var1);
4275 		    if (key == NULL)
4276 			return FAIL;
4277 		}
4278 
4279 		item = dict_find(rettv->vval.v_dict, key, (int)keylen);
4280 
4281 		if (item == NULL && verbose)
4282 		    semsg(_(e_dictkey), key);
4283 		if (item == NULL)
4284 		    return FAIL;
4285 
4286 		copy_tv(&item->di_tv, &tmp);
4287 		clear_tv(rettv);
4288 		*rettv = tmp;
4289 	    }
4290 	    break;
4291     }
4292     return OK;
4293 }
4294 
4295 /*
4296  * Return the function name of partial "pt".
4297  */
4298     char_u *
4299 partial_name(partial_T *pt)
4300 {
4301     if (pt != NULL)
4302     {
4303 	if (pt->pt_name != NULL)
4304 	    return pt->pt_name;
4305 	if (pt->pt_func != NULL)
4306 	    return pt->pt_func->uf_name;
4307     }
4308     return (char_u *)"";
4309 }
4310 
4311     static void
4312 partial_free(partial_T *pt)
4313 {
4314     int i;
4315 
4316     for (i = 0; i < pt->pt_argc; ++i)
4317 	clear_tv(&pt->pt_argv[i]);
4318     vim_free(pt->pt_argv);
4319     dict_unref(pt->pt_dict);
4320     if (pt->pt_name != NULL)
4321     {
4322 	func_unref(pt->pt_name);
4323 	vim_free(pt->pt_name);
4324     }
4325     else
4326 	func_ptr_unref(pt->pt_func);
4327 
4328     // Decrease the reference count for the context of a closure.  If down
4329     // to the minimum it may be time to free it.
4330     if (pt->pt_funcstack != NULL)
4331     {
4332 	--pt->pt_funcstack->fs_refcount;
4333 	funcstack_check_refcount(pt->pt_funcstack);
4334     }
4335 
4336     vim_free(pt);
4337 }
4338 
4339 /*
4340  * Unreference a closure: decrement the reference count and free it when it
4341  * becomes zero.
4342  */
4343     void
4344 partial_unref(partial_T *pt)
4345 {
4346     if (pt != NULL)
4347     {
4348 	if (--pt->pt_refcount <= 0)
4349 	    partial_free(pt);
4350 
4351 	// If the reference count goes down to one, the funcstack may be the
4352 	// only reference and can be freed if no other partials reference it.
4353 	else if (pt->pt_refcount == 1 && pt->pt_funcstack != NULL)
4354 	    funcstack_check_refcount(pt->pt_funcstack);
4355     }
4356 }
4357 
4358 /*
4359  * Return the next (unique) copy ID.
4360  * Used for serializing nested structures.
4361  */
4362     int
4363 get_copyID(void)
4364 {
4365     current_copyID += COPYID_INC;
4366     return current_copyID;
4367 }
4368 
4369 /*
4370  * Garbage collection for lists and dictionaries.
4371  *
4372  * We use reference counts to be able to free most items right away when they
4373  * are no longer used.  But for composite items it's possible that it becomes
4374  * unused while the reference count is > 0: When there is a recursive
4375  * reference.  Example:
4376  *	:let l = [1, 2, 3]
4377  *	:let d = {9: l}
4378  *	:let l[1] = d
4379  *
4380  * Since this is quite unusual we handle this with garbage collection: every
4381  * once in a while find out which lists and dicts are not referenced from any
4382  * variable.
4383  *
4384  * Here is a good reference text about garbage collection (refers to Python
4385  * but it applies to all reference-counting mechanisms):
4386  *	http://python.ca/nas/python/gc/
4387  */
4388 
4389 /*
4390  * Do garbage collection for lists and dicts.
4391  * When "testing" is TRUE this is called from test_garbagecollect_now().
4392  * Return TRUE if some memory was freed.
4393  */
4394     int
4395 garbage_collect(int testing)
4396 {
4397     int		copyID;
4398     int		abort = FALSE;
4399     buf_T	*buf;
4400     win_T	*wp;
4401     int		did_free = FALSE;
4402     tabpage_T	*tp;
4403 
4404     if (!testing)
4405     {
4406 	// Only do this once.
4407 	want_garbage_collect = FALSE;
4408 	may_garbage_collect = FALSE;
4409 	garbage_collect_at_exit = FALSE;
4410     }
4411 
4412     // The execution stack can grow big, limit the size.
4413     if (exestack.ga_maxlen - exestack.ga_len > 500)
4414     {
4415 	size_t	new_len;
4416 	char_u	*pp;
4417 	int	n;
4418 
4419 	// Keep 150% of the current size, with a minimum of the growth size.
4420 	n = exestack.ga_len / 2;
4421 	if (n < exestack.ga_growsize)
4422 	    n = exestack.ga_growsize;
4423 
4424 	// Don't make it bigger though.
4425 	if (exestack.ga_len + n < exestack.ga_maxlen)
4426 	{
4427 	    new_len = exestack.ga_itemsize * (exestack.ga_len + n);
4428 	    pp = vim_realloc(exestack.ga_data, new_len);
4429 	    if (pp == NULL)
4430 		return FAIL;
4431 	    exestack.ga_maxlen = exestack.ga_len + n;
4432 	    exestack.ga_data = pp;
4433 	}
4434     }
4435 
4436     // We advance by two because we add one for items referenced through
4437     // previous_funccal.
4438     copyID = get_copyID();
4439 
4440     /*
4441      * 1. Go through all accessible variables and mark all lists and dicts
4442      *    with copyID.
4443      */
4444 
4445     // Don't free variables in the previous_funccal list unless they are only
4446     // referenced through previous_funccal.  This must be first, because if
4447     // the item is referenced elsewhere the funccal must not be freed.
4448     abort = abort || set_ref_in_previous_funccal(copyID);
4449 
4450     // script-local variables
4451     abort = abort || garbage_collect_scriptvars(copyID);
4452 
4453     // buffer-local variables
4454     FOR_ALL_BUFFERS(buf)
4455 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
4456 								  NULL, NULL);
4457 
4458     // window-local variables
4459     FOR_ALL_TAB_WINDOWS(tp, wp)
4460 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4461 								  NULL, NULL);
4462     if (aucmd_win != NULL)
4463 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
4464 								  NULL, NULL);
4465 #ifdef FEAT_PROP_POPUP
4466     FOR_ALL_POPUPWINS(wp)
4467 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4468 								  NULL, NULL);
4469     FOR_ALL_TABPAGES(tp)
4470 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
4471 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4472 								  NULL, NULL);
4473 #endif
4474 
4475     // tabpage-local variables
4476     FOR_ALL_TABPAGES(tp)
4477 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
4478 								  NULL, NULL);
4479     // global variables
4480     abort = abort || garbage_collect_globvars(copyID);
4481 
4482     // function-local variables
4483     abort = abort || set_ref_in_call_stack(copyID);
4484 
4485     // named functions (matters for closures)
4486     abort = abort || set_ref_in_functions(copyID);
4487 
4488     // function call arguments, if v:testing is set.
4489     abort = abort || set_ref_in_func_args(copyID);
4490 
4491     // v: vars
4492     abort = abort || garbage_collect_vimvars(copyID);
4493 
4494     // callbacks in buffers
4495     abort = abort || set_ref_in_buffers(copyID);
4496 
4497 #ifdef FEAT_LUA
4498     abort = abort || set_ref_in_lua(copyID);
4499 #endif
4500 
4501 #ifdef FEAT_PYTHON
4502     abort = abort || set_ref_in_python(copyID);
4503 #endif
4504 
4505 #ifdef FEAT_PYTHON3
4506     abort = abort || set_ref_in_python3(copyID);
4507 #endif
4508 
4509 #ifdef FEAT_JOB_CHANNEL
4510     abort = abort || set_ref_in_channel(copyID);
4511     abort = abort || set_ref_in_job(copyID);
4512 #endif
4513 #ifdef FEAT_NETBEANS_INTG
4514     abort = abort || set_ref_in_nb_channel(copyID);
4515 #endif
4516 
4517 #ifdef FEAT_TIMERS
4518     abort = abort || set_ref_in_timer(copyID);
4519 #endif
4520 
4521 #ifdef FEAT_QUICKFIX
4522     abort = abort || set_ref_in_quickfix(copyID);
4523 #endif
4524 
4525 #ifdef FEAT_TERMINAL
4526     abort = abort || set_ref_in_term(copyID);
4527 #endif
4528 
4529 #ifdef FEAT_PROP_POPUP
4530     abort = abort || set_ref_in_popups(copyID);
4531 #endif
4532 
4533     if (!abort)
4534     {
4535 	/*
4536 	 * 2. Free lists and dictionaries that are not referenced.
4537 	 */
4538 	did_free = free_unref_items(copyID);
4539 
4540 	/*
4541 	 * 3. Check if any funccal can be freed now.
4542 	 *    This may call us back recursively.
4543 	 */
4544 	free_unref_funccal(copyID, testing);
4545     }
4546     else if (p_verbose > 0)
4547     {
4548 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
4549     }
4550 
4551     return did_free;
4552 }
4553 
4554 /*
4555  * Free lists, dictionaries, channels and jobs that are no longer referenced.
4556  */
4557     static int
4558 free_unref_items(int copyID)
4559 {
4560     int		did_free = FALSE;
4561 
4562     // Let all "free" functions know that we are here.  This means no
4563     // dictionaries, lists, channels or jobs are to be freed, because we will
4564     // do that here.
4565     in_free_unref_items = TRUE;
4566 
4567     /*
4568      * PASS 1: free the contents of the items.  We don't free the items
4569      * themselves yet, so that it is possible to decrement refcount counters
4570      */
4571 
4572     // Go through the list of dicts and free items without the copyID.
4573     did_free |= dict_free_nonref(copyID);
4574 
4575     // Go through the list of lists and free items without the copyID.
4576     did_free |= list_free_nonref(copyID);
4577 
4578 #ifdef FEAT_JOB_CHANNEL
4579     // Go through the list of jobs and free items without the copyID. This
4580     // must happen before doing channels, because jobs refer to channels, but
4581     // the reference from the channel to the job isn't tracked.
4582     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4583 
4584     // Go through the list of channels and free items without the copyID.
4585     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4586 #endif
4587 
4588     /*
4589      * PASS 2: free the items themselves.
4590      */
4591     dict_free_items(copyID);
4592     list_free_items(copyID);
4593 
4594 #ifdef FEAT_JOB_CHANNEL
4595     // Go through the list of jobs and free items without the copyID. This
4596     // must happen before doing channels, because jobs refer to channels, but
4597     // the reference from the channel to the job isn't tracked.
4598     free_unused_jobs(copyID, COPYID_MASK);
4599 
4600     // Go through the list of channels and free items without the copyID.
4601     free_unused_channels(copyID, COPYID_MASK);
4602 #endif
4603 
4604     in_free_unref_items = FALSE;
4605 
4606     return did_free;
4607 }
4608 
4609 /*
4610  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4611  * "list_stack" is used to add lists to be marked.  Can be NULL.
4612  *
4613  * Returns TRUE if setting references failed somehow.
4614  */
4615     int
4616 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4617 {
4618     int		todo;
4619     int		abort = FALSE;
4620     hashitem_T	*hi;
4621     hashtab_T	*cur_ht;
4622     ht_stack_T	*ht_stack = NULL;
4623     ht_stack_T	*tempitem;
4624 
4625     cur_ht = ht;
4626     for (;;)
4627     {
4628 	if (!abort)
4629 	{
4630 	    // Mark each item in the hashtab.  If the item contains a hashtab
4631 	    // it is added to ht_stack, if it contains a list it is added to
4632 	    // list_stack.
4633 	    todo = (int)cur_ht->ht_used;
4634 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4635 		if (!HASHITEM_EMPTY(hi))
4636 		{
4637 		    --todo;
4638 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4639 						       &ht_stack, list_stack);
4640 		}
4641 	}
4642 
4643 	if (ht_stack == NULL)
4644 	    break;
4645 
4646 	// take an item from the stack
4647 	cur_ht = ht_stack->ht;
4648 	tempitem = ht_stack;
4649 	ht_stack = ht_stack->prev;
4650 	free(tempitem);
4651     }
4652 
4653     return abort;
4654 }
4655 
4656 /*
4657  * Mark a dict and its items with "copyID".
4658  * Returns TRUE if setting references failed somehow.
4659  */
4660     int
4661 set_ref_in_dict(dict_T *d, int copyID)
4662 {
4663     if (d != NULL && d->dv_copyID != copyID)
4664     {
4665 	d->dv_copyID = copyID;
4666 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4667     }
4668     return FALSE;
4669 }
4670 
4671 /*
4672  * Mark a list and its items with "copyID".
4673  * Returns TRUE if setting references failed somehow.
4674  */
4675     int
4676 set_ref_in_list(list_T *ll, int copyID)
4677 {
4678     if (ll != NULL && ll->lv_copyID != copyID)
4679     {
4680 	ll->lv_copyID = copyID;
4681 	return set_ref_in_list_items(ll, copyID, NULL);
4682     }
4683     return FALSE;
4684 }
4685 
4686 /*
4687  * Mark all lists and dicts referenced through list "l" with "copyID".
4688  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4689  *
4690  * Returns TRUE if setting references failed somehow.
4691  */
4692     int
4693 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4694 {
4695     listitem_T	 *li;
4696     int		 abort = FALSE;
4697     list_T	 *cur_l;
4698     list_stack_T *list_stack = NULL;
4699     list_stack_T *tempitem;
4700 
4701     cur_l = l;
4702     for (;;)
4703     {
4704 	if (!abort && cur_l->lv_first != &range_list_item)
4705 	    // Mark each item in the list.  If the item contains a hashtab
4706 	    // it is added to ht_stack, if it contains a list it is added to
4707 	    // list_stack.
4708 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4709 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4710 						       ht_stack, &list_stack);
4711 	if (list_stack == NULL)
4712 	    break;
4713 
4714 	// take an item from the stack
4715 	cur_l = list_stack->list;
4716 	tempitem = list_stack;
4717 	list_stack = list_stack->prev;
4718 	free(tempitem);
4719     }
4720 
4721     return abort;
4722 }
4723 
4724 /*
4725  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4726  * "list_stack" is used to add lists to be marked.  Can be NULL.
4727  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4728  *
4729  * Returns TRUE if setting references failed somehow.
4730  */
4731     int
4732 set_ref_in_item(
4733     typval_T	    *tv,
4734     int		    copyID,
4735     ht_stack_T	    **ht_stack,
4736     list_stack_T    **list_stack)
4737 {
4738     int		abort = FALSE;
4739 
4740     if (tv->v_type == VAR_DICT)
4741     {
4742 	dict_T	*dd = tv->vval.v_dict;
4743 
4744 	if (dd != NULL && dd->dv_copyID != copyID)
4745 	{
4746 	    // Didn't see this dict yet.
4747 	    dd->dv_copyID = copyID;
4748 	    if (ht_stack == NULL)
4749 	    {
4750 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4751 	    }
4752 	    else
4753 	    {
4754 		ht_stack_T *newitem = ALLOC_ONE(ht_stack_T);
4755 
4756 		if (newitem == NULL)
4757 		    abort = TRUE;
4758 		else
4759 		{
4760 		    newitem->ht = &dd->dv_hashtab;
4761 		    newitem->prev = *ht_stack;
4762 		    *ht_stack = newitem;
4763 		}
4764 	    }
4765 	}
4766     }
4767     else if (tv->v_type == VAR_LIST)
4768     {
4769 	list_T	*ll = tv->vval.v_list;
4770 
4771 	if (ll != NULL && ll->lv_copyID != copyID)
4772 	{
4773 	    // Didn't see this list yet.
4774 	    ll->lv_copyID = copyID;
4775 	    if (list_stack == NULL)
4776 	    {
4777 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4778 	    }
4779 	    else
4780 	    {
4781 		list_stack_T *newitem = ALLOC_ONE(list_stack_T);
4782 
4783 		if (newitem == NULL)
4784 		    abort = TRUE;
4785 		else
4786 		{
4787 		    newitem->list = ll;
4788 		    newitem->prev = *list_stack;
4789 		    *list_stack = newitem;
4790 		}
4791 	    }
4792 	}
4793     }
4794     else if (tv->v_type == VAR_FUNC)
4795     {
4796 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4797     }
4798     else if (tv->v_type == VAR_PARTIAL)
4799     {
4800 	partial_T	*pt = tv->vval.v_partial;
4801 	int		i;
4802 
4803 	if (pt != NULL && pt->pt_copyID != copyID)
4804 	{
4805 	    // Didn't see this partial yet.
4806 	    pt->pt_copyID = copyID;
4807 
4808 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4809 
4810 	    if (pt->pt_dict != NULL)
4811 	    {
4812 		typval_T dtv;
4813 
4814 		dtv.v_type = VAR_DICT;
4815 		dtv.vval.v_dict = pt->pt_dict;
4816 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4817 	    }
4818 
4819 	    for (i = 0; i < pt->pt_argc; ++i)
4820 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4821 							ht_stack, list_stack);
4822 	    if (pt->pt_funcstack != NULL)
4823 	    {
4824 		typval_T    *stack = pt->pt_funcstack->fs_ga.ga_data;
4825 
4826 		for (i = 0; i < pt->pt_funcstack->fs_ga.ga_len; ++i)
4827 		    abort = abort || set_ref_in_item(stack + i, copyID,
4828 							 ht_stack, list_stack);
4829 	    }
4830 
4831 	}
4832     }
4833 #ifdef FEAT_JOB_CHANNEL
4834     else if (tv->v_type == VAR_JOB)
4835     {
4836 	job_T	    *job = tv->vval.v_job;
4837 	typval_T    dtv;
4838 
4839 	if (job != NULL && job->jv_copyID != copyID)
4840 	{
4841 	    job->jv_copyID = copyID;
4842 	    if (job->jv_channel != NULL)
4843 	    {
4844 		dtv.v_type = VAR_CHANNEL;
4845 		dtv.vval.v_channel = job->jv_channel;
4846 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4847 	    }
4848 	    if (job->jv_exit_cb.cb_partial != NULL)
4849 	    {
4850 		dtv.v_type = VAR_PARTIAL;
4851 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4852 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4853 	    }
4854 	}
4855     }
4856     else if (tv->v_type == VAR_CHANNEL)
4857     {
4858 	channel_T   *ch =tv->vval.v_channel;
4859 	ch_part_T   part;
4860 	typval_T    dtv;
4861 	jsonq_T	    *jq;
4862 	cbq_T	    *cq;
4863 
4864 	if (ch != NULL && ch->ch_copyID != copyID)
4865 	{
4866 	    ch->ch_copyID = copyID;
4867 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4868 	    {
4869 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4870 							     jq = jq->jq_next)
4871 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4872 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4873 							     cq = cq->cq_next)
4874 		    if (cq->cq_callback.cb_partial != NULL)
4875 		    {
4876 			dtv.v_type = VAR_PARTIAL;
4877 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4878 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4879 		    }
4880 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4881 		{
4882 		    dtv.v_type = VAR_PARTIAL;
4883 		    dtv.vval.v_partial =
4884 				      ch->ch_part[part].ch_callback.cb_partial;
4885 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4886 		}
4887 	    }
4888 	    if (ch->ch_callback.cb_partial != NULL)
4889 	    {
4890 		dtv.v_type = VAR_PARTIAL;
4891 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4892 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4893 	    }
4894 	    if (ch->ch_close_cb.cb_partial != NULL)
4895 	    {
4896 		dtv.v_type = VAR_PARTIAL;
4897 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4898 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4899 	    }
4900 	}
4901     }
4902 #endif
4903     return abort;
4904 }
4905 
4906 /*
4907  * Return a string with the string representation of a variable.
4908  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4909  * "numbuf" is used for a number.
4910  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4911  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4912  * strings as "string()", otherwise does not put quotes around strings, as
4913  * ":echo" displays values.
4914  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4915  * are replaced with "...".
4916  * May return NULL.
4917  */
4918     char_u *
4919 echo_string_core(
4920     typval_T	*tv,
4921     char_u	**tofree,
4922     char_u	*numbuf,
4923     int		copyID,
4924     int		echo_style,
4925     int		restore_copyID,
4926     int		composite_val)
4927 {
4928     static int	recurse = 0;
4929     char_u	*r = NULL;
4930 
4931     if (recurse >= DICT_MAXNEST)
4932     {
4933 	if (!did_echo_string_emsg)
4934 	{
4935 	    // Only give this message once for a recursive call to avoid
4936 	    // flooding the user with errors.  And stop iterating over lists
4937 	    // and dicts.
4938 	    did_echo_string_emsg = TRUE;
4939 	    emsg(_("E724: variable nested too deep for displaying"));
4940 	}
4941 	*tofree = NULL;
4942 	return (char_u *)"{E724}";
4943     }
4944     ++recurse;
4945 
4946     switch (tv->v_type)
4947     {
4948 	case VAR_STRING:
4949 	    if (echo_style && !composite_val)
4950 	    {
4951 		*tofree = NULL;
4952 		r = tv->vval.v_string;
4953 		if (r == NULL)
4954 		    r = (char_u *)"";
4955 	    }
4956 	    else
4957 	    {
4958 		*tofree = string_quote(tv->vval.v_string, FALSE);
4959 		r = *tofree;
4960 	    }
4961 	    break;
4962 
4963 	case VAR_FUNC:
4964 	    if (echo_style)
4965 	    {
4966 		*tofree = NULL;
4967 		r = tv->vval.v_string;
4968 	    }
4969 	    else
4970 	    {
4971 		*tofree = string_quote(tv->vval.v_string, TRUE);
4972 		r = *tofree;
4973 	    }
4974 	    break;
4975 
4976 	case VAR_PARTIAL:
4977 	    {
4978 		partial_T   *pt = tv->vval.v_partial;
4979 		char_u	    *fname = string_quote(pt == NULL ? NULL
4980 						    : partial_name(pt), FALSE);
4981 		garray_T    ga;
4982 		int	    i;
4983 		char_u	    *tf;
4984 
4985 		ga_init2(&ga, 1, 100);
4986 		ga_concat(&ga, (char_u *)"function(");
4987 		if (fname != NULL)
4988 		{
4989 		    ga_concat(&ga, fname);
4990 		    vim_free(fname);
4991 		}
4992 		if (pt != NULL && pt->pt_argc > 0)
4993 		{
4994 		    ga_concat(&ga, (char_u *)", [");
4995 		    for (i = 0; i < pt->pt_argc; ++i)
4996 		    {
4997 			if (i > 0)
4998 			    ga_concat(&ga, (char_u *)", ");
4999 			ga_concat(&ga,
5000 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
5001 			vim_free(tf);
5002 		    }
5003 		    ga_concat(&ga, (char_u *)"]");
5004 		}
5005 		if (pt != NULL && pt->pt_dict != NULL)
5006 		{
5007 		    typval_T dtv;
5008 
5009 		    ga_concat(&ga, (char_u *)", ");
5010 		    dtv.v_type = VAR_DICT;
5011 		    dtv.vval.v_dict = pt->pt_dict;
5012 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
5013 		    vim_free(tf);
5014 		}
5015 		ga_concat(&ga, (char_u *)")");
5016 
5017 		*tofree = ga.ga_data;
5018 		r = *tofree;
5019 		break;
5020 	    }
5021 
5022 	case VAR_BLOB:
5023 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
5024 	    break;
5025 
5026 	case VAR_LIST:
5027 	    if (tv->vval.v_list == NULL)
5028 	    {
5029 		// NULL list is equivalent to empty list.
5030 		*tofree = NULL;
5031 		r = (char_u *)"[]";
5032 	    }
5033 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
5034 		    && tv->vval.v_list->lv_len > 0)
5035 	    {
5036 		*tofree = NULL;
5037 		r = (char_u *)"[...]";
5038 	    }
5039 	    else
5040 	    {
5041 		int old_copyID = tv->vval.v_list->lv_copyID;
5042 
5043 		tv->vval.v_list->lv_copyID = copyID;
5044 		*tofree = list2string(tv, copyID, restore_copyID);
5045 		if (restore_copyID)
5046 		    tv->vval.v_list->lv_copyID = old_copyID;
5047 		r = *tofree;
5048 	    }
5049 	    break;
5050 
5051 	case VAR_DICT:
5052 	    if (tv->vval.v_dict == NULL)
5053 	    {
5054 		// NULL dict is equivalent to empty dict.
5055 		*tofree = NULL;
5056 		r = (char_u *)"{}";
5057 	    }
5058 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
5059 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
5060 	    {
5061 		*tofree = NULL;
5062 		r = (char_u *)"{...}";
5063 	    }
5064 	    else
5065 	    {
5066 		int old_copyID = tv->vval.v_dict->dv_copyID;
5067 
5068 		tv->vval.v_dict->dv_copyID = copyID;
5069 		*tofree = dict2string(tv, copyID, restore_copyID);
5070 		if (restore_copyID)
5071 		    tv->vval.v_dict->dv_copyID = old_copyID;
5072 		r = *tofree;
5073 	    }
5074 	    break;
5075 
5076 	case VAR_NUMBER:
5077 	case VAR_UNKNOWN:
5078 	case VAR_ANY:
5079 	case VAR_VOID:
5080 	    *tofree = NULL;
5081 	    r = tv_get_string_buf(tv, numbuf);
5082 	    break;
5083 
5084 	case VAR_JOB:
5085 	case VAR_CHANNEL:
5086 	    *tofree = NULL;
5087 	    r = tv_get_string_buf(tv, numbuf);
5088 	    if (composite_val)
5089 	    {
5090 		*tofree = string_quote(r, FALSE);
5091 		r = *tofree;
5092 	    }
5093 	    break;
5094 
5095 	case VAR_INSTR:
5096 	    *tofree = NULL;
5097 	    r = (char_u *)"instructions";
5098 	    break;
5099 
5100 	case VAR_FLOAT:
5101 #ifdef FEAT_FLOAT
5102 	    *tofree = NULL;
5103 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
5104 	    r = numbuf;
5105 	    break;
5106 #endif
5107 
5108 	case VAR_BOOL:
5109 	case VAR_SPECIAL:
5110 	    *tofree = NULL;
5111 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
5112 	    break;
5113     }
5114 
5115     if (--recurse == 0)
5116 	did_echo_string_emsg = FALSE;
5117     return r;
5118 }
5119 
5120 /*
5121  * Return a string with the string representation of a variable.
5122  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5123  * "numbuf" is used for a number.
5124  * Does not put quotes around strings, as ":echo" displays values.
5125  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5126  * May return NULL.
5127  */
5128     char_u *
5129 echo_string(
5130     typval_T	*tv,
5131     char_u	**tofree,
5132     char_u	*numbuf,
5133     int		copyID)
5134 {
5135     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
5136 }
5137 
5138 /*
5139  * Return string "str" in ' quotes, doubling ' characters.
5140  * If "str" is NULL an empty string is assumed.
5141  * If "function" is TRUE make it function('string').
5142  */
5143     char_u *
5144 string_quote(char_u *str, int function)
5145 {
5146     unsigned	len;
5147     char_u	*p, *r, *s;
5148 
5149     len = (function ? 13 : 3);
5150     if (str != NULL)
5151     {
5152 	len += (unsigned)STRLEN(str);
5153 	for (p = str; *p != NUL; MB_PTR_ADV(p))
5154 	    if (*p == '\'')
5155 		++len;
5156     }
5157     s = r = alloc(len);
5158     if (r != NULL)
5159     {
5160 	if (function)
5161 	{
5162 	    STRCPY(r, "function('");
5163 	    r += 10;
5164 	}
5165 	else
5166 	    *r++ = '\'';
5167 	if (str != NULL)
5168 	    for (p = str; *p != NUL; )
5169 	    {
5170 		if (*p == '\'')
5171 		    *r++ = '\'';
5172 		MB_COPY_CHAR(p, r);
5173 	    }
5174 	*r++ = '\'';
5175 	if (function)
5176 	    *r++ = ')';
5177 	*r++ = NUL;
5178     }
5179     return s;
5180 }
5181 
5182 #if defined(FEAT_FLOAT) || defined(PROTO)
5183 /*
5184  * Convert the string "text" to a floating point number.
5185  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
5186  * this always uses a decimal point.
5187  * Returns the length of the text that was consumed.
5188  */
5189     int
5190 string2float(
5191     char_u	*text,
5192     float_T	*value)	    // result stored here
5193 {
5194     char	*s = (char *)text;
5195     float_T	f;
5196 
5197     // MS-Windows does not deal with "inf" and "nan" properly.
5198     if (STRNICMP(text, "inf", 3) == 0)
5199     {
5200 	*value = INFINITY;
5201 	return 3;
5202     }
5203     if (STRNICMP(text, "-inf", 3) == 0)
5204     {
5205 	*value = -INFINITY;
5206 	return 4;
5207     }
5208     if (STRNICMP(text, "nan", 3) == 0)
5209     {
5210 	*value = NAN;
5211 	return 3;
5212     }
5213     f = strtod(s, &s);
5214     *value = f;
5215     return (int)((char_u *)s - text);
5216 }
5217 #endif
5218 
5219 /*
5220  * Convert the specified byte index of line 'lnum' in buffer 'buf' to a
5221  * character index.  Works only for loaded buffers. Returns -1 on failure.
5222  * The index of the first byte and the first character is zero.
5223  */
5224     int
5225 buf_byteidx_to_charidx(buf_T *buf, int lnum, int byteidx)
5226 {
5227     char_u	*str;
5228     char_u	*t;
5229     int		count;
5230 
5231     if (buf == NULL || buf->b_ml.ml_mfp == NULL)
5232 	return -1;
5233 
5234     if (lnum > buf->b_ml.ml_line_count)
5235 	lnum = buf->b_ml.ml_line_count;
5236 
5237     str = ml_get_buf(buf, lnum, FALSE);
5238     if (str == NULL)
5239 	return -1;
5240 
5241     if (*str == NUL)
5242 	return 0;
5243 
5244     // count the number of characters
5245     t = str;
5246     for (count = 0; *t != NUL && t <= str + byteidx; count++)
5247 	t += mb_ptr2len(t);
5248 
5249     // In insert mode, when the cursor is at the end of a non-empty line,
5250     // byteidx points to the NUL character immediately past the end of the
5251     // string. In this case, add one to the character count.
5252     if (*t == NUL && byteidx != 0 && t == str + byteidx)
5253 	count++;
5254 
5255     return count - 1;
5256 }
5257 
5258 /*
5259  * Convert the specified character index of line 'lnum' in buffer 'buf' to a
5260  * byte index.  Works only for loaded buffers. Returns -1 on failure.
5261  * The index of the first byte and the first character is zero.
5262  */
5263     int
5264 buf_charidx_to_byteidx(buf_T *buf, int lnum, int charidx)
5265 {
5266     char_u	*str;
5267     char_u	*t;
5268 
5269     if (buf == NULL || buf->b_ml.ml_mfp == NULL)
5270 	return -1;
5271 
5272     if (lnum > buf->b_ml.ml_line_count)
5273 	lnum = buf->b_ml.ml_line_count;
5274 
5275     str = ml_get_buf(buf, lnum, FALSE);
5276     if (str == NULL)
5277 	return -1;
5278 
5279     // Convert the character offset to a byte offset
5280     t = str;
5281     while (*t != NUL && --charidx > 0)
5282 	t += mb_ptr2len(t);
5283 
5284     return t - str;
5285 }
5286 
5287 /*
5288  * Translate a String variable into a position.
5289  * Returns NULL when there is an error.
5290  */
5291     pos_T *
5292 var2fpos(
5293     typval_T	*varp,
5294     int		dollar_lnum,	// TRUE when $ is last line
5295     int		*fnum,		// set to fnum for '0, 'A, etc.
5296     int		charcol)	// return character column
5297 {
5298     char_u		*name;
5299     static pos_T	pos;
5300     pos_T		*pp;
5301 
5302     // Argument can be [lnum, col, coladd].
5303     if (varp->v_type == VAR_LIST)
5304     {
5305 	list_T		*l;
5306 	int		len;
5307 	int		error = FALSE;
5308 	listitem_T	*li;
5309 
5310 	l = varp->vval.v_list;
5311 	if (l == NULL)
5312 	    return NULL;
5313 
5314 	// Get the line number
5315 	pos.lnum = list_find_nr(l, 0L, &error);
5316 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
5317 	    return NULL;	// invalid line number
5318 	if (charcol)
5319 	    len = (long)mb_charlen(ml_get(pos.lnum));
5320 	else
5321 	    len = (long)STRLEN(ml_get(pos.lnum));
5322 
5323 	// Get the column number
5324 	// We accept "$" for the column number: last column.
5325 	li = list_find(l, 1L);
5326 	if (li != NULL && li->li_tv.v_type == VAR_STRING
5327 		&& li->li_tv.vval.v_string != NULL
5328 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
5329 	{
5330 	    pos.col = len + 1;
5331 	}
5332 	else
5333 	{
5334 	    pos.col = list_find_nr(l, 1L, &error);
5335 	    if (error)
5336 		return NULL;
5337 	}
5338 
5339 	// Accept a position up to the NUL after the line.
5340 	if (pos.col == 0 || (int)pos.col > len + 1)
5341 	    return NULL;	// invalid column number
5342 	--pos.col;
5343 
5344 	// Get the virtual offset.  Defaults to zero.
5345 	pos.coladd = list_find_nr(l, 2L, &error);
5346 	if (error)
5347 	    pos.coladd = 0;
5348 
5349 	return &pos;
5350     }
5351 
5352     if (in_vim9script() && check_for_string_arg(varp, 0) == FAIL)
5353 	return NULL;
5354 
5355     name = tv_get_string_chk(varp);
5356     if (name == NULL)
5357 	return NULL;
5358     if (name[0] == '.')				// cursor
5359     {
5360 	pos = curwin->w_cursor;
5361 	if (charcol)
5362 	    pos.col = buf_byteidx_to_charidx(curbuf, pos.lnum, pos.col);
5363 	return &pos;
5364     }
5365     if (name[0] == 'v' && name[1] == NUL)	// Visual start
5366     {
5367 	if (VIsual_active)
5368 	    pos = VIsual;
5369 	else
5370 	    pos = curwin->w_cursor;
5371 	if (charcol)
5372 	    pos.col = buf_byteidx_to_charidx(curbuf, pos.lnum, pos.col);
5373 	return &pos;
5374     }
5375     if (name[0] == '\'')			// mark
5376     {
5377 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
5378 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
5379 	    return NULL;
5380 	if (charcol)
5381 	    pp->col = buf_byteidx_to_charidx(curbuf, pp->lnum, pp->col);
5382 	return pp;
5383     }
5384 
5385     pos.coladd = 0;
5386 
5387     if (name[0] == 'w' && dollar_lnum)
5388     {
5389 	pos.col = 0;
5390 	if (name[1] == '0')		// "w0": first visible line
5391 	{
5392 	    update_topline();
5393 	    // In silent Ex mode topline is zero, but that's not a valid line
5394 	    // number; use one instead.
5395 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
5396 	    return &pos;
5397 	}
5398 	else if (name[1] == '$')	// "w$": last visible line
5399 	{
5400 	    validate_botline();
5401 	    // In silent Ex mode botline is zero, return zero then.
5402 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
5403 	    return &pos;
5404 	}
5405     }
5406     else if (name[0] == '$')		// last column or line
5407     {
5408 	if (dollar_lnum)
5409 	{
5410 	    pos.lnum = curbuf->b_ml.ml_line_count;
5411 	    pos.col = 0;
5412 	}
5413 	else
5414 	{
5415 	    pos.lnum = curwin->w_cursor.lnum;
5416 	    if (charcol)
5417 		pos.col = (colnr_T)mb_charlen(ml_get_curline());
5418 	    else
5419 		pos.col = (colnr_T)STRLEN(ml_get_curline());
5420 	}
5421 	return &pos;
5422     }
5423     return NULL;
5424 }
5425 
5426 /*
5427  * Convert list in "arg" into a position and optional file number.
5428  * When "fnump" is NULL there is no file number, only 3 items.
5429  * Note that the column is passed on as-is, the caller may want to decrement
5430  * it to use 1 for the first column.
5431  * Return FAIL when conversion is not possible, doesn't check the position for
5432  * validity.
5433  */
5434     int
5435 list2fpos(
5436     typval_T	*arg,
5437     pos_T	*posp,
5438     int		*fnump,
5439     colnr_T	*curswantp,
5440     int		charcol)
5441 {
5442     list_T	*l = arg->vval.v_list;
5443     long	i = 0;
5444     long	n;
5445 
5446     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
5447     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
5448     if (arg->v_type != VAR_LIST
5449 	    || l == NULL
5450 	    || l->lv_len < (fnump == NULL ? 2 : 3)
5451 	    || l->lv_len > (fnump == NULL ? 4 : 5))
5452 	return FAIL;
5453 
5454     if (fnump != NULL)
5455     {
5456 	n = list_find_nr(l, i++, NULL);	// fnum
5457 	if (n < 0)
5458 	    return FAIL;
5459 	if (n == 0)
5460 	    n = curbuf->b_fnum;		// current buffer
5461 	*fnump = n;
5462     }
5463 
5464     n = list_find_nr(l, i++, NULL);	// lnum
5465     if (n < 0)
5466 	return FAIL;
5467     posp->lnum = n;
5468 
5469     n = list_find_nr(l, i++, NULL);	// col
5470     if (n < 0)
5471 	return FAIL;
5472     // If character position is specified, then convert to byte position
5473     if (charcol)
5474     {
5475 	buf_T	*buf;
5476 
5477 	// Get the text for the specified line in a loaded buffer
5478 	buf = buflist_findnr(fnump == NULL ? curbuf->b_fnum : *fnump);
5479 	if (buf == NULL || buf->b_ml.ml_mfp == NULL)
5480 	    return FAIL;
5481 
5482 	n = buf_charidx_to_byteidx(buf, posp->lnum, n) + 1;
5483     }
5484     posp->col = n;
5485 
5486     n = list_find_nr(l, i, NULL);	// off
5487     if (n < 0)
5488 	posp->coladd = 0;
5489     else
5490 	posp->coladd = n;
5491 
5492     if (curswantp != NULL)
5493 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
5494 
5495     return OK;
5496 }
5497 
5498 /*
5499  * Get the length of an environment variable name.
5500  * Advance "arg" to the first character after the name.
5501  * Return 0 for error.
5502  */
5503     int
5504 get_env_len(char_u **arg)
5505 {
5506     char_u	*p;
5507     int		len;
5508 
5509     for (p = *arg; vim_isIDc(*p); ++p)
5510 	;
5511     if (p == *arg)	    // no name found
5512 	return 0;
5513 
5514     len = (int)(p - *arg);
5515     *arg = p;
5516     return len;
5517 }
5518 
5519 /*
5520  * Get the length of the name of a function or internal variable.
5521  * "arg" is advanced to after the name.
5522  * Return 0 if something is wrong.
5523  */
5524     int
5525 get_id_len(char_u **arg)
5526 {
5527     char_u	*p;
5528     int		len;
5529 
5530     // Find the end of the name.
5531     for (p = *arg; eval_isnamec(*p); ++p)
5532     {
5533 	if (*p == ':')
5534 	{
5535 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5536 	    // slice "[n:]".  Also "xx:" is not a namespace.
5537 	    len = (int)(p - *arg);
5538 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
5539 		    || len > 1)
5540 		break;
5541 	}
5542     }
5543     if (p == *arg)	    // no name found
5544 	return 0;
5545 
5546     len = (int)(p - *arg);
5547     *arg = p;
5548 
5549     return len;
5550 }
5551 
5552 /*
5553  * Get the length of the name of a variable or function.
5554  * Only the name is recognized, does not handle ".key" or "[idx]".
5555  * "arg" is advanced to the first non-white character after the name.
5556  * Return -1 if curly braces expansion failed.
5557  * Return 0 if something else is wrong.
5558  * If the name contains 'magic' {}'s, expand them and return the
5559  * expanded name in an allocated string via 'alias' - caller must free.
5560  */
5561     int
5562 get_name_len(
5563     char_u	**arg,
5564     char_u	**alias,
5565     int		evaluate,
5566     int		verbose)
5567 {
5568     int		len;
5569     char_u	*p;
5570     char_u	*expr_start;
5571     char_u	*expr_end;
5572 
5573     *alias = NULL;  // default to no alias
5574 
5575     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
5576 						  && (*arg)[2] == (int)KE_SNR)
5577     {
5578 	// hard coded <SNR>, already translated
5579 	*arg += 3;
5580 	return get_id_len(arg) + 3;
5581     }
5582     len = eval_fname_script(*arg);
5583     if (len > 0)
5584     {
5585 	// literal "<SID>", "s:" or "<SNR>"
5586 	*arg += len;
5587     }
5588 
5589     /*
5590      * Find the end of the name; check for {} construction.
5591      */
5592     p = find_name_end(*arg, &expr_start, &expr_end,
5593 					       len > 0 ? 0 : FNE_CHECK_START);
5594     if (expr_start != NULL)
5595     {
5596 	char_u	*temp_string;
5597 
5598 	if (!evaluate)
5599 	{
5600 	    len += (int)(p - *arg);
5601 	    *arg = skipwhite(p);
5602 	    return len;
5603 	}
5604 
5605 	/*
5606 	 * Include any <SID> etc in the expanded string:
5607 	 * Thus the -len here.
5608 	 */
5609 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
5610 	if (temp_string == NULL)
5611 	    return -1;
5612 	*alias = temp_string;
5613 	*arg = skipwhite(p);
5614 	return (int)STRLEN(temp_string);
5615     }
5616 
5617     len += get_id_len(arg);
5618     // Only give an error when there is something, otherwise it will be
5619     // reported at a higher level.
5620     if (len == 0 && verbose && **arg != NUL)
5621 	semsg(_(e_invexpr2), *arg);
5622 
5623     return len;
5624 }
5625 
5626 /*
5627  * Find the end of a variable or function name, taking care of magic braces.
5628  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
5629  * start and end of the first magic braces item.
5630  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
5631  * Return a pointer to just after the name.  Equal to "arg" if there is no
5632  * valid name.
5633  */
5634     char_u *
5635 find_name_end(
5636     char_u	*arg,
5637     char_u	**expr_start,
5638     char_u	**expr_end,
5639     int		flags)
5640 {
5641     int		mb_nest = 0;
5642     int		br_nest = 0;
5643     char_u	*p;
5644     int		len;
5645     int		vim9script = in_vim9script();
5646 
5647     if (expr_start != NULL)
5648     {
5649 	*expr_start = NULL;
5650 	*expr_end = NULL;
5651     }
5652 
5653     // Quick check for valid starting character.
5654     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg)
5655 						&& (*arg != '{' || vim9script))
5656 	return arg;
5657 
5658     for (p = arg; *p != NUL
5659 		    && (eval_isnamec(*p)
5660 			|| (*p == '{' && !vim9script)
5661 			|| ((flags & FNE_INCL_BR) && (*p == '['
5662 					 || (*p == '.' && eval_isdictc(p[1]))))
5663 			|| mb_nest != 0
5664 			|| br_nest != 0); MB_PTR_ADV(p))
5665     {
5666 	if (*p == '\'')
5667 	{
5668 	    // skip over 'string' to avoid counting [ and ] inside it.
5669 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5670 		;
5671 	    if (*p == NUL)
5672 		break;
5673 	}
5674 	else if (*p == '"')
5675 	{
5676 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
5677 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5678 		if (*p == '\\' && p[1] != NUL)
5679 		    ++p;
5680 	    if (*p == NUL)
5681 		break;
5682 	}
5683 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5684 	{
5685 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5686 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
5687 	    len = (int)(p - arg);
5688 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5689 		    || (len > 1 && p[-1] != '}'))
5690 		break;
5691 	}
5692 
5693 	if (mb_nest == 0)
5694 	{
5695 	    if (*p == '[')
5696 		++br_nest;
5697 	    else if (*p == ']')
5698 		--br_nest;
5699 	}
5700 
5701 	if (br_nest == 0 && !vim9script)
5702 	{
5703 	    if (*p == '{')
5704 	    {
5705 		mb_nest++;
5706 		if (expr_start != NULL && *expr_start == NULL)
5707 		    *expr_start = p;
5708 	    }
5709 	    else if (*p == '}')
5710 	    {
5711 		mb_nest--;
5712 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5713 		    *expr_end = p;
5714 	    }
5715 	}
5716     }
5717 
5718     return p;
5719 }
5720 
5721 /*
5722  * Expands out the 'magic' {}'s in a variable/function name.
5723  * Note that this can call itself recursively, to deal with
5724  * constructs like foo{bar}{baz}{bam}
5725  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5726  *			"in_start"      ^
5727  *			"expr_start"	   ^
5728  *			"expr_end"		 ^
5729  *			"in_end"			    ^
5730  *
5731  * Returns a new allocated string, which the caller must free.
5732  * Returns NULL for failure.
5733  */
5734     static char_u *
5735 make_expanded_name(
5736     char_u	*in_start,
5737     char_u	*expr_start,
5738     char_u	*expr_end,
5739     char_u	*in_end)
5740 {
5741     char_u	c1;
5742     char_u	*retval = NULL;
5743     char_u	*temp_result;
5744 
5745     if (expr_end == NULL || in_end == NULL)
5746 	return NULL;
5747     *expr_start	= NUL;
5748     *expr_end = NUL;
5749     c1 = *in_end;
5750     *in_end = NUL;
5751 
5752     temp_result = eval_to_string(expr_start + 1, FALSE);
5753     if (temp_result != NULL)
5754     {
5755 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5756 						   + (in_end - expr_end) + 1);
5757 	if (retval != NULL)
5758 	{
5759 	    STRCPY(retval, in_start);
5760 	    STRCAT(retval, temp_result);
5761 	    STRCAT(retval, expr_end + 1);
5762 	}
5763     }
5764     vim_free(temp_result);
5765 
5766     *in_end = c1;		// put char back for error messages
5767     *expr_start = '{';
5768     *expr_end = '}';
5769 
5770     if (retval != NULL)
5771     {
5772 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5773 	if (expr_start != NULL)
5774 	{
5775 	    // Further expansion!
5776 	    temp_result = make_expanded_name(retval, expr_start,
5777 						       expr_end, temp_result);
5778 	    vim_free(retval);
5779 	    retval = temp_result;
5780 	}
5781     }
5782 
5783     return retval;
5784 }
5785 
5786 /*
5787  * Return TRUE if character "c" can be used in a variable or function name.
5788  * Does not include '{' or '}' for magic braces.
5789  */
5790     int
5791 eval_isnamec(int c)
5792 {
5793     return ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR;
5794 }
5795 
5796 /*
5797  * Return TRUE if character "c" can be used as the first character in a
5798  * variable or function name (excluding '{' and '}').
5799  */
5800     int
5801 eval_isnamec1(int c)
5802 {
5803     return ASCII_ISALPHA(c) || c == '_';
5804 }
5805 
5806 /*
5807  * Return TRUE if character "c" can be used as the first character of a
5808  * dictionary key.
5809  */
5810     int
5811 eval_isdictc(int c)
5812 {
5813     return ASCII_ISALNUM(c) || c == '_';
5814 }
5815 
5816 /*
5817  * Handle:
5818  * - expr[expr], expr[expr:expr] subscript
5819  * - ".name" lookup
5820  * - function call with Funcref variable: func(expr)
5821  * - method call: var->method()
5822  *
5823  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5824  */
5825     int
5826 handle_subscript(
5827     char_u	**arg,
5828     typval_T	*rettv,
5829     evalarg_T	*evalarg,
5830     int		verbose)	// give error messages
5831 {
5832     int		evaluate = evalarg != NULL
5833 				      && (evalarg->eval_flags & EVAL_EVALUATE);
5834     int		ret = OK;
5835     dict_T	*selfdict = NULL;
5836     int		check_white = TRUE;
5837     int		getnext;
5838     char_u	*p;
5839 
5840     while (ret == OK)
5841     {
5842 	// When at the end of the line and ".name" or "->{" or "->X" follows in
5843 	// the next line then consume the line break.
5844 	p = eval_next_non_blank(*arg, evalarg, &getnext);
5845 	if (getnext
5846 	    && ((rettv->v_type == VAR_DICT && *p == '.' && eval_isdictc(p[1]))
5847 		|| (p[0] == '-' && p[1] == '>'
5848 				     && (p[2] == '{' || ASCII_ISALPHA(p[2])))))
5849 	{
5850 	    *arg = eval_next_line(evalarg);
5851 	    p = *arg;
5852 	    check_white = FALSE;
5853 	}
5854 
5855 	if (rettv->v_type == VAR_ANY)
5856 	{
5857 	    char_u	*exp_name;
5858 	    int		cc;
5859 	    int		idx;
5860 	    ufunc_T	*ufunc;
5861 	    type_T	*type;
5862 
5863 	    // Found script from "import * as {name}", script item name must
5864 	    // follow.
5865 	    if (**arg != '.')
5866 	    {
5867 		if (verbose)
5868 		    semsg(_(e_expected_str_but_got_str), "'.'", *arg);
5869 		ret = FAIL;
5870 		break;
5871 	    }
5872 	    ++*arg;
5873 	    if (IS_WHITE_OR_NUL(**arg))
5874 	    {
5875 		if (verbose)
5876 		    emsg(_(e_no_white_space_allowed_after_dot));
5877 		ret = FAIL;
5878 		break;
5879 	    }
5880 
5881 	    // isolate the name
5882 	    exp_name = *arg;
5883 	    while (eval_isnamec(**arg))
5884 		++*arg;
5885 	    cc = **arg;
5886 	    **arg = NUL;
5887 
5888 	    idx = find_exported(rettv->vval.v_number, exp_name, &ufunc, &type,
5889 						  evalarg->eval_cctx, verbose);
5890 	    **arg = cc;
5891 	    *arg = skipwhite(*arg);
5892 
5893 	    if (idx < 0 && ufunc == NULL)
5894 	    {
5895 		ret = FAIL;
5896 		break;
5897 	    }
5898 	    if (idx >= 0)
5899 	    {
5900 		scriptitem_T    *si = SCRIPT_ITEM(rettv->vval.v_number);
5901 		svar_T		*sv = ((svar_T *)si->sn_var_vals.ga_data) + idx;
5902 
5903 		copy_tv(sv->sv_tv, rettv);
5904 	    }
5905 	    else
5906 	    {
5907 		rettv->v_type = VAR_FUNC;
5908 		rettv->vval.v_string = vim_strsave(ufunc->uf_name);
5909 	    }
5910 	}
5911 
5912 	if ((**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5913 			    || rettv->v_type == VAR_PARTIAL))
5914 		    && (!check_white || !VIM_ISWHITE(*(*arg - 1))))
5915 	{
5916 	    ret = call_func_rettv(arg, evalarg, rettv, evaluate,
5917 							       selfdict, NULL);
5918 
5919 	    // Stop the expression evaluation when immediately aborting on
5920 	    // error, or when an interrupt occurred or an exception was thrown
5921 	    // but not caught.
5922 	    if (aborting())
5923 	    {
5924 		if (ret == OK)
5925 		    clear_tv(rettv);
5926 		ret = FAIL;
5927 	    }
5928 	    dict_unref(selfdict);
5929 	    selfdict = NULL;
5930 	}
5931 	else if (p[0] == '-' && p[1] == '>')
5932 	{
5933 	    if (in_vim9script())
5934 		*arg = skipwhite(p + 2);
5935 	    else
5936 		*arg = p + 2;
5937 	    if (ret == OK)
5938 	    {
5939 		if (VIM_ISWHITE(**arg))
5940 		{
5941 		    emsg(_(e_nowhitespace));
5942 		    ret = FAIL;
5943 		}
5944 		else if ((**arg == '{' && !in_vim9script()) || **arg == '(')
5945 		    // expr->{lambda}() or expr->(lambda)()
5946 		    ret = eval_lambda(arg, rettv, evalarg, verbose);
5947 		else
5948 		    // expr->name()
5949 		    ret = eval_method(arg, rettv, evalarg, verbose);
5950 	    }
5951 	}
5952 	// "." is ".name" lookup when we found a dict or when evaluating and
5953 	// scriptversion is at least 2, where string concatenation is "..".
5954 	else if (**arg == '['
5955 		|| (**arg == '.' && (rettv->v_type == VAR_DICT
5956 			|| (!evaluate
5957 			    && (*arg)[1] != '.'
5958 			    && current_sctx.sc_version >= 2))))
5959 	{
5960 	    dict_unref(selfdict);
5961 	    if (rettv->v_type == VAR_DICT)
5962 	    {
5963 		selfdict = rettv->vval.v_dict;
5964 		if (selfdict != NULL)
5965 		    ++selfdict->dv_refcount;
5966 	    }
5967 	    else
5968 		selfdict = NULL;
5969 	    if (eval_index(arg, rettv, evalarg, verbose) == FAIL)
5970 	    {
5971 		clear_tv(rettv);
5972 		ret = FAIL;
5973 	    }
5974 	}
5975 	else
5976 	    break;
5977     }
5978 
5979     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5980     // Don't do this when "Func" is already a partial that was bound
5981     // explicitly (pt_auto is FALSE).
5982     if (selfdict != NULL
5983 	    && (rettv->v_type == VAR_FUNC
5984 		|| (rettv->v_type == VAR_PARTIAL
5985 		    && (rettv->vval.v_partial->pt_auto
5986 			|| rettv->vval.v_partial->pt_dict == NULL))))
5987 	selfdict = make_partial(selfdict, rettv);
5988 
5989     dict_unref(selfdict);
5990     return ret;
5991 }
5992 
5993 /*
5994  * Make a copy of an item.
5995  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5996  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5997  * reference to an already copied list/dict can be used.
5998  * Returns FAIL or OK.
5999  */
6000     int
6001 item_copy(
6002     typval_T	*from,
6003     typval_T	*to,
6004     int		deep,
6005     int		copyID)
6006 {
6007     static int	recurse = 0;
6008     int		ret = OK;
6009 
6010     if (recurse >= DICT_MAXNEST)
6011     {
6012 	emsg(_("E698: variable nested too deep for making a copy"));
6013 	return FAIL;
6014     }
6015     ++recurse;
6016 
6017     switch (from->v_type)
6018     {
6019 	case VAR_NUMBER:
6020 	case VAR_FLOAT:
6021 	case VAR_STRING:
6022 	case VAR_FUNC:
6023 	case VAR_PARTIAL:
6024 	case VAR_BOOL:
6025 	case VAR_SPECIAL:
6026 	case VAR_JOB:
6027 	case VAR_CHANNEL:
6028 	case VAR_INSTR:
6029 	    copy_tv(from, to);
6030 	    break;
6031 	case VAR_LIST:
6032 	    to->v_type = VAR_LIST;
6033 	    to->v_lock = 0;
6034 	    if (from->vval.v_list == NULL)
6035 		to->vval.v_list = NULL;
6036 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
6037 	    {
6038 		// use the copy made earlier
6039 		to->vval.v_list = from->vval.v_list->lv_copylist;
6040 		++to->vval.v_list->lv_refcount;
6041 	    }
6042 	    else
6043 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
6044 	    if (to->vval.v_list == NULL)
6045 		ret = FAIL;
6046 	    break;
6047 	case VAR_BLOB:
6048 	    ret = blob_copy(from->vval.v_blob, to);
6049 	    break;
6050 	case VAR_DICT:
6051 	    to->v_type = VAR_DICT;
6052 	    to->v_lock = 0;
6053 	    if (from->vval.v_dict == NULL)
6054 		to->vval.v_dict = NULL;
6055 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
6056 	    {
6057 		// use the copy made earlier
6058 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
6059 		++to->vval.v_dict->dv_refcount;
6060 	    }
6061 	    else
6062 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
6063 	    if (to->vval.v_dict == NULL)
6064 		ret = FAIL;
6065 	    break;
6066 	case VAR_UNKNOWN:
6067 	case VAR_ANY:
6068 	case VAR_VOID:
6069 	    internal_error_no_abort("item_copy(UNKNOWN)");
6070 	    ret = FAIL;
6071     }
6072     --recurse;
6073     return ret;
6074 }
6075 
6076     void
6077 echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr)
6078 {
6079     char_u	*tofree;
6080     char_u	numbuf[NUMBUFLEN];
6081     char_u	*p = echo_string(rettv, &tofree, numbuf, get_copyID());
6082 
6083     if (*atstart)
6084     {
6085 	*atstart = FALSE;
6086 	// Call msg_start() after eval1(), evaluating the expression
6087 	// may cause a message to appear.
6088 	if (with_space)
6089 	{
6090 	    // Mark the saved text as finishing the line, so that what
6091 	    // follows is displayed on a new line when scrolling back
6092 	    // at the more prompt.
6093 	    msg_sb_eol();
6094 	    msg_start();
6095 	}
6096     }
6097     else if (with_space)
6098 	msg_puts_attr(" ", echo_attr);
6099 
6100     if (p != NULL)
6101 	for ( ; *p != NUL && !got_int; ++p)
6102 	{
6103 	    if (*p == '\n' || *p == '\r' || *p == TAB)
6104 	    {
6105 		if (*p != TAB && *needclr)
6106 		{
6107 		    // remove any text still there from the command
6108 		    msg_clr_eos();
6109 		    *needclr = FALSE;
6110 		}
6111 		msg_putchar_attr(*p, echo_attr);
6112 	    }
6113 	    else
6114 	    {
6115 		if (has_mbyte)
6116 		{
6117 		    int i = (*mb_ptr2len)(p);
6118 
6119 		    (void)msg_outtrans_len_attr(p, i, echo_attr);
6120 		    p += i - 1;
6121 		}
6122 		else
6123 		    (void)msg_outtrans_len_attr(p, 1, echo_attr);
6124 	    }
6125 	}
6126     vim_free(tofree);
6127 }
6128 
6129 /*
6130  * ":echo expr1 ..."	print each argument separated with a space, add a
6131  *			newline at the end.
6132  * ":echon expr1 ..."	print each argument plain.
6133  */
6134     void
6135 ex_echo(exarg_T *eap)
6136 {
6137     char_u	*arg = eap->arg;
6138     typval_T	rettv;
6139     char_u	*arg_start;
6140     int		needclr = TRUE;
6141     int		atstart = TRUE;
6142     int		did_emsg_before = did_emsg;
6143     int		called_emsg_before = called_emsg;
6144     evalarg_T	evalarg;
6145 
6146     fill_evalarg_from_eap(&evalarg, eap, eap->skip);
6147 
6148     if (eap->skip)
6149 	++emsg_skip;
6150     while ((!ends_excmd2(eap->cmd, arg) || *arg == '"') && !got_int)
6151     {
6152 	// If eval1() causes an error message the text from the command may
6153 	// still need to be cleared. E.g., "echo 22,44".
6154 	need_clr_eos = needclr;
6155 
6156 	arg_start = arg;
6157 	if (eval1(&arg, &rettv, &evalarg) == FAIL)
6158 	{
6159 	    /*
6160 	     * Report the invalid expression unless the expression evaluation
6161 	     * has been cancelled due to an aborting error, an interrupt, or an
6162 	     * exception.
6163 	     */
6164 	    if (!aborting() && did_emsg == did_emsg_before
6165 					  && called_emsg == called_emsg_before)
6166 		semsg(_(e_invexpr2), arg_start);
6167 	    need_clr_eos = FALSE;
6168 	    break;
6169 	}
6170 	need_clr_eos = FALSE;
6171 
6172 	if (!eap->skip)
6173 	{
6174 	    if (rettv.v_type == VAR_VOID)
6175 	    {
6176 		semsg(_(e_expression_does_not_result_in_value_str), arg_start);
6177 		break;
6178 	    }
6179 	    echo_one(&rettv, eap->cmdidx == CMD_echo, &atstart, &needclr);
6180 	}
6181 
6182 	clear_tv(&rettv);
6183 	arg = skipwhite(arg);
6184     }
6185     eap->nextcmd = check_nextcmd(arg);
6186     clear_evalarg(&evalarg, eap);
6187 
6188     if (eap->skip)
6189 	--emsg_skip;
6190     else
6191     {
6192 	// remove text that may still be there from the command
6193 	if (needclr)
6194 	    msg_clr_eos();
6195 	if (eap->cmdidx == CMD_echo)
6196 	    msg_end();
6197     }
6198 }
6199 
6200 /*
6201  * ":echohl {name}".
6202  */
6203     void
6204 ex_echohl(exarg_T *eap)
6205 {
6206     echo_attr = syn_name2attr(eap->arg);
6207 }
6208 
6209 /*
6210  * Returns the :echo attribute
6211  */
6212     int
6213 get_echo_attr(void)
6214 {
6215     return echo_attr;
6216 }
6217 
6218 /*
6219  * ":execute expr1 ..."	execute the result of an expression.
6220  * ":echomsg expr1 ..."	Print a message
6221  * ":echoerr expr1 ..."	Print an error
6222  * ":echoconsole expr1 ..." Print a message on stdout
6223  * Each gets spaces around each argument and a newline at the end for
6224  * echo commands
6225  */
6226     void
6227 ex_execute(exarg_T *eap)
6228 {
6229     char_u	*arg = eap->arg;
6230     typval_T	rettv;
6231     int		ret = OK;
6232     char_u	*p;
6233     garray_T	ga;
6234     int		len;
6235 
6236     ga_init2(&ga, 1, 80);
6237 
6238     if (eap->skip)
6239 	++emsg_skip;
6240     while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
6241     {
6242 	ret = eval1_emsg(&arg, &rettv, eap);
6243 	if (ret == FAIL)
6244 	    break;
6245 
6246 	if (!eap->skip)
6247 	{
6248 	    char_u   buf[NUMBUFLEN];
6249 
6250 	    if (eap->cmdidx == CMD_execute)
6251 	    {
6252 		if (rettv.v_type == VAR_CHANNEL || rettv.v_type == VAR_JOB)
6253 		{
6254 		    semsg(_(e_using_invalid_value_as_string_str),
6255 						  vartype_name(rettv.v_type));
6256 		    p = NULL;
6257 		}
6258 		else
6259 		    p = tv_get_string_buf(&rettv, buf);
6260 	    }
6261 	    else
6262 		p = tv_stringify(&rettv, buf);
6263 	    if (p == NULL)
6264 	    {
6265 		clear_tv(&rettv);
6266 		ret = FAIL;
6267 		break;
6268 	    }
6269 	    len = (int)STRLEN(p);
6270 	    if (ga_grow(&ga, len + 2) == FAIL)
6271 	    {
6272 		clear_tv(&rettv);
6273 		ret = FAIL;
6274 		break;
6275 	    }
6276 	    if (ga.ga_len)
6277 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
6278 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
6279 	    ga.ga_len += len;
6280 	}
6281 
6282 	clear_tv(&rettv);
6283 	arg = skipwhite(arg);
6284     }
6285 
6286     if (ret != FAIL && ga.ga_data != NULL)
6287     {
6288 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
6289 	{
6290 	    // Mark the already saved text as finishing the line, so that what
6291 	    // follows is displayed on a new line when scrolling back at the
6292 	    // more prompt.
6293 	    msg_sb_eol();
6294 	}
6295 
6296 	if (eap->cmdidx == CMD_echomsg)
6297 	{
6298 	    msg_attr(ga.ga_data, echo_attr);
6299 	    out_flush();
6300 	}
6301 	else if (eap->cmdidx == CMD_echoconsole)
6302 	{
6303 	    ui_write(ga.ga_data, (int)STRLEN(ga.ga_data), TRUE);
6304 	    ui_write((char_u *)"\r\n", 2, TRUE);
6305 	}
6306 	else if (eap->cmdidx == CMD_echoerr)
6307 	{
6308 	    int		save_did_emsg = did_emsg;
6309 
6310 	    // We don't want to abort following commands, restore did_emsg.
6311 	    emsg(ga.ga_data);
6312 	    if (!force_abort)
6313 		did_emsg = save_did_emsg;
6314 	}
6315 	else if (eap->cmdidx == CMD_execute)
6316 	    do_cmdline((char_u *)ga.ga_data,
6317 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
6318     }
6319 
6320     ga_clear(&ga);
6321 
6322     if (eap->skip)
6323 	--emsg_skip;
6324 
6325     eap->nextcmd = check_nextcmd(arg);
6326 }
6327 
6328 /*
6329  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
6330  * "arg" points to the "&" or '+' when called, to "option" when returning.
6331  * Returns NULL when no option name found.  Otherwise pointer to the char
6332  * after the option name.
6333  */
6334     char_u *
6335 find_option_end(char_u **arg, int *opt_flags)
6336 {
6337     char_u	*p = *arg;
6338 
6339     ++p;
6340     if (*p == 'g' && p[1] == ':')
6341     {
6342 	*opt_flags = OPT_GLOBAL;
6343 	p += 2;
6344     }
6345     else if (*p == 'l' && p[1] == ':')
6346     {
6347 	*opt_flags = OPT_LOCAL;
6348 	p += 2;
6349     }
6350     else
6351 	*opt_flags = 0;
6352 
6353     if (!ASCII_ISALPHA(*p))
6354 	return NULL;
6355     *arg = p;
6356 
6357     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
6358 	p += 4;	    // termcap option
6359     else
6360 	while (ASCII_ISALPHA(*p))
6361 	    ++p;
6362     return p;
6363 }
6364 
6365 /*
6366  * Display script name where an item was last set.
6367  * Should only be invoked when 'verbose' is non-zero.
6368  */
6369     void
6370 last_set_msg(sctx_T script_ctx)
6371 {
6372     char_u *p;
6373 
6374     if (script_ctx.sc_sid != 0)
6375     {
6376 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
6377 	if (p != NULL)
6378 	{
6379 	    verbose_enter();
6380 	    msg_puts(_("\n\tLast set from "));
6381 	    msg_puts((char *)p);
6382 	    if (script_ctx.sc_lnum > 0)
6383 	    {
6384 		msg_puts(_(line_msg));
6385 		msg_outnum((long)script_ctx.sc_lnum);
6386 	    }
6387 	    verbose_leave();
6388 	    vim_free(p);
6389 	}
6390     }
6391 }
6392 
6393 #endif // FEAT_EVAL
6394 
6395 /*
6396  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
6397  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
6398  * "flags" can be "g" to do a global substitute.
6399  * Returns an allocated string, NULL for error.
6400  */
6401     char_u *
6402 do_string_sub(
6403     char_u	*str,
6404     char_u	*pat,
6405     char_u	*sub,
6406     typval_T	*expr,
6407     char_u	*flags)
6408 {
6409     int		sublen;
6410     regmatch_T	regmatch;
6411     int		i;
6412     int		do_all;
6413     char_u	*tail;
6414     char_u	*end;
6415     garray_T	ga;
6416     char_u	*ret;
6417     char_u	*save_cpo;
6418     char_u	*zero_width = NULL;
6419 
6420     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
6421     save_cpo = p_cpo;
6422     p_cpo = empty_option;
6423 
6424     ga_init2(&ga, 1, 200);
6425 
6426     do_all = (flags[0] == 'g');
6427 
6428     regmatch.rm_ic = p_ic;
6429     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
6430     if (regmatch.regprog != NULL)
6431     {
6432 	tail = str;
6433 	end = str + STRLEN(str);
6434 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
6435 	{
6436 	    // Skip empty match except for first match.
6437 	    if (regmatch.startp[0] == regmatch.endp[0])
6438 	    {
6439 		if (zero_width == regmatch.startp[0])
6440 		{
6441 		    // avoid getting stuck on a match with an empty string
6442 		    i = mb_ptr2len(tail);
6443 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
6444 								   (size_t)i);
6445 		    ga.ga_len += i;
6446 		    tail += i;
6447 		    continue;
6448 		}
6449 		zero_width = regmatch.startp[0];
6450 	    }
6451 
6452 	    /*
6453 	     * Get some space for a temporary buffer to do the substitution
6454 	     * into.  It will contain:
6455 	     * - The text up to where the match is.
6456 	     * - The substituted text.
6457 	     * - The text after the match.
6458 	     */
6459 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
6460 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
6461 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
6462 	    {
6463 		ga_clear(&ga);
6464 		break;
6465 	    }
6466 
6467 	    // copy the text up to where the match is
6468 	    i = (int)(regmatch.startp[0] - tail);
6469 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
6470 	    // add the substituted text
6471 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
6472 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
6473 	    ga.ga_len += i + sublen - 1;
6474 	    tail = regmatch.endp[0];
6475 	    if (*tail == NUL)
6476 		break;
6477 	    if (!do_all)
6478 		break;
6479 	}
6480 
6481 	if (ga.ga_data != NULL)
6482 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
6483 
6484 	vim_regfree(regmatch.regprog);
6485     }
6486 
6487     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
6488     ga_clear(&ga);
6489     if (p_cpo == empty_option)
6490 	p_cpo = save_cpo;
6491     else
6492     {
6493 	// Darn, evaluating {sub} expression or {expr} changed the value.
6494 	// If it's still empty it was changed and restored, need to restore in
6495 	// the complicated way.
6496 	if (*p_cpo == NUL)
6497 	    set_option_value((char_u *)"cpo", 0L, save_cpo, 0);
6498 	free_string_option(save_cpo);
6499     }
6500 
6501     return ret;
6502 }
6503