xref: /vim-8.2.3635/src/eval.c (revision 040f975f)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * eval.c: Expression evaluation.
12  */
13 #define USING_FLOAT_STUFF
14 
15 #include "vim.h"
16 
17 #if defined(FEAT_EVAL) || defined(PROTO)
18 
19 #ifdef VMS
20 # include <float.h>
21 #endif
22 
23 static char *e_dictrange = N_("E719: Cannot use [:] with a Dictionary");
24 
25 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
26 
27 /*
28  * When recursively copying lists and dicts we need to remember which ones we
29  * have done to avoid endless recursiveness.  This unique ID is used for that.
30  * The last bit is used for previous_funccal, ignored when comparing.
31  */
32 static int current_copyID = 0;
33 
34 /*
35  * Info used by a ":for" loop.
36  */
37 typedef struct
38 {
39     int		fi_semicolon;	// TRUE if ending in '; var]'
40     int		fi_varcount;	// nr of variables in the list
41     int		fi_break_count;	// nr of line breaks encountered
42     listwatch_T	fi_lw;		// keep an eye on the item used.
43     list_T	*fi_list;	// list being used
44     int		fi_bi;		// index of blob
45     blob_T	*fi_blob;	// blob being used
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 eval7(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int want_string);
55 static int eval7_leader(typval_T *rettv, int numeric_only, char_u *start_leader, char_u **end_leaderp);
56 
57 static int free_unref_items(int copyID);
58 static char_u *make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
59 
60 /*
61  * Return "n1" divided by "n2", taking care of dividing by zero.
62  */
63 	varnumber_T
64 num_divide(varnumber_T n1, varnumber_T n2)
65 {
66     varnumber_T	result;
67 
68     if (n2 == 0)	// give an error message?
69     {
70 	if (n1 == 0)
71 	    result = VARNUM_MIN; // similar to NaN
72 	else if (n1 < 0)
73 	    result = -VARNUM_MAX;
74 	else
75 	    result = VARNUM_MAX;
76     }
77     else
78 	result = n1 / n2;
79 
80     return result;
81 }
82 
83 /*
84  * Return "n1" modulus "n2", taking care of dividing by zero.
85  */
86 	varnumber_T
87 num_modulus(varnumber_T n1, varnumber_T n2)
88 {
89     // Give an error when n2 is 0?
90     return (n2 == 0) ? 0 : (n1 % n2);
91 }
92 
93 #if defined(EBCDIC) || defined(PROTO)
94 /*
95  * Compare struct fst by function name.
96  */
97     static int
98 compare_func_name(const void *s1, const void *s2)
99 {
100     struct fst *p1 = (struct fst *)s1;
101     struct fst *p2 = (struct fst *)s2;
102 
103     return STRCMP(p1->f_name, p2->f_name);
104 }
105 
106 /*
107  * Sort the function table by function name.
108  * The sorting of the table above is ASCII dependent.
109  * On machines using EBCDIC we have to sort it.
110  */
111     static void
112 sortFunctions(void)
113 {
114     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
115 
116     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
117 }
118 #endif
119 
120 /*
121  * Initialize the global and v: variables.
122  */
123     void
124 eval_init(void)
125 {
126     evalvars_init();
127     func_init();
128 
129 #ifdef EBCDIC
130     /*
131      * Sort the function table, to enable binary search.
132      */
133     sortFunctions();
134 #endif
135 }
136 
137 #if defined(EXITFREE) || defined(PROTO)
138     void
139 eval_clear(void)
140 {
141     evalvars_clear();
142     free_scriptnames();  // must come after evalvars_clear().
143     free_locales();
144 
145     // autoloaded script names
146     free_autoload_scriptnames();
147 
148     // unreferenced lists and dicts
149     (void)garbage_collect(FALSE);
150 
151     // functions not garbage collected
152     free_all_functions();
153 }
154 #endif
155 
156     void
157 fill_evalarg_from_eap(evalarg_T *evalarg, exarg_T *eap, int skip)
158 {
159     CLEAR_FIELD(*evalarg);
160     evalarg->eval_flags = skip ? 0 : EVAL_EVALUATE;
161     if (eap != NULL && getline_equal(eap->getline, eap->cookie, getsourceline))
162     {
163 	evalarg->eval_getline = eap->getline;
164 	evalarg->eval_cookie = eap->cookie;
165     }
166 }
167 
168 /*
169  * Top level evaluation function, returning a boolean.
170  * Sets "error" to TRUE if there was an error.
171  * Return TRUE or FALSE.
172  */
173     int
174 eval_to_bool(
175     char_u	*arg,
176     int		*error,
177     exarg_T	*eap,
178     int		skip)	    // only parse, don't execute
179 {
180     typval_T	tv;
181     varnumber_T	retval = FALSE;
182     evalarg_T	evalarg;
183 
184     fill_evalarg_from_eap(&evalarg, eap, skip);
185 
186     if (skip)
187 	++emsg_skip;
188     if (eval0(arg, &tv, eap, &evalarg) == FAIL)
189 	*error = TRUE;
190     else
191     {
192 	*error = FALSE;
193 	if (!skip)
194 	{
195 	    if (in_vim9script())
196 		retval = tv2bool(&tv);
197 	    else
198 		retval = (tv_get_number_chk(&tv, error) != 0);
199 	    clear_tv(&tv);
200 	}
201     }
202     if (skip)
203 	--emsg_skip;
204     clear_evalarg(&evalarg, eap);
205 
206     return (int)retval;
207 }
208 
209 /*
210  * Call eval1() and give an error message if not done at a lower level.
211  */
212     static int
213 eval1_emsg(char_u **arg, typval_T *rettv, exarg_T *eap)
214 {
215     char_u	*start = *arg;
216     int		ret;
217     int		did_emsg_before = did_emsg;
218     int		called_emsg_before = called_emsg;
219     evalarg_T	evalarg;
220 
221     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
222 
223     ret = eval1(arg, rettv, &evalarg);
224     if (ret == FAIL)
225     {
226 	// Report the invalid expression unless the expression evaluation has
227 	// been cancelled due to an aborting error, an interrupt, or an
228 	// exception, or we already gave a more specific error.
229 	// Also check called_emsg for when using assert_fails().
230 	if (!aborting() && did_emsg == did_emsg_before
231 					  && called_emsg == called_emsg_before)
232 	    semsg(_(e_invexpr2), start);
233     }
234     clear_evalarg(&evalarg, eap);
235     return ret;
236 }
237 
238 /*
239  * Return whether a typval is a valid expression to pass to eval_expr_typval()
240  * or eval_expr_to_bool().  An empty string returns FALSE;
241  */
242     int
243 eval_expr_valid_arg(typval_T *tv)
244 {
245     return tv->v_type != VAR_UNKNOWN
246 	    && (tv->v_type != VAR_STRING
247 		  || (tv->vval.v_string != NULL && *tv->vval.v_string != NUL));
248 }
249 
250 /*
251  * Evaluate an expression, which can be a function, partial or string.
252  * Pass arguments "argv[argc]".
253  * Return the result in "rettv" and OK or FAIL.
254  */
255     int
256 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
257 {
258     char_u	*s;
259     char_u	buf[NUMBUFLEN];
260     funcexe_T	funcexe;
261 
262     if (expr->v_type == VAR_FUNC)
263     {
264 	s = expr->vval.v_string;
265 	if (s == NULL || *s == NUL)
266 	    return FAIL;
267 	CLEAR_FIELD(funcexe);
268 	funcexe.evaluate = TRUE;
269 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
270 	    return FAIL;
271     }
272     else if (expr->v_type == VAR_PARTIAL)
273     {
274 	partial_T   *partial = expr->vval.v_partial;
275 
276 	if (partial == NULL)
277 	    return FAIL;
278 
279 	if (partial->pt_func != NULL
280 			  && partial->pt_func->uf_def_status != UF_NOT_COMPILED)
281 	{
282 	    if (call_def_function(partial->pt_func, argc, argv,
283 						       partial, rettv) == FAIL)
284 		return FAIL;
285 	}
286 	else
287 	{
288 	    s = partial_name(partial);
289 	    if (s == NULL || *s == NUL)
290 		return FAIL;
291 	    CLEAR_FIELD(funcexe);
292 	    funcexe.evaluate = TRUE;
293 	    funcexe.partial = partial;
294 	    if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
295 		return FAIL;
296 	}
297     }
298     else
299     {
300 	s = tv_get_string_buf_chk(expr, buf);
301 	if (s == NULL)
302 	    return FAIL;
303 	s = skipwhite(s);
304 	if (eval1_emsg(&s, rettv, NULL) == FAIL)
305 	    return FAIL;
306 	if (*skipwhite(s) != NUL)  // check for trailing chars after expr
307 	{
308 	    clear_tv(rettv);
309 	    semsg(_(e_invexpr2), s);
310 	    return FAIL;
311 	}
312     }
313     return OK;
314 }
315 
316 /*
317  * Like eval_to_bool() but using a typval_T instead of a string.
318  * Works for string, funcref and partial.
319  */
320     int
321 eval_expr_to_bool(typval_T *expr, int *error)
322 {
323     typval_T	rettv;
324     int		res;
325 
326     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
327     {
328 	*error = TRUE;
329 	return FALSE;
330     }
331     res = (tv_get_number_chk(&rettv, error) != 0);
332     clear_tv(&rettv);
333     return res;
334 }
335 
336 /*
337  * Top level evaluation function, returning a string.  If "skip" is TRUE,
338  * only parsing to "nextcmd" is done, without reporting errors.  Return
339  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
340  */
341     char_u *
342 eval_to_string_skip(
343     char_u	*arg,
344     exarg_T	*eap,
345     int		skip)	    // only parse, don't execute
346 {
347     typval_T	tv;
348     char_u	*retval;
349     evalarg_T	evalarg;
350 
351     fill_evalarg_from_eap(&evalarg, eap, skip);
352     if (skip)
353 	++emsg_skip;
354     if (eval0(arg, &tv, eap, &evalarg) == FAIL || skip)
355 	retval = NULL;
356     else
357     {
358 	retval = vim_strsave(tv_get_string(&tv));
359 	clear_tv(&tv);
360     }
361     if (skip)
362 	--emsg_skip;
363     clear_evalarg(&evalarg, eap);
364 
365     return retval;
366 }
367 
368 /*
369  * Skip over an expression at "*pp".
370  * Return FAIL for an error, OK otherwise.
371  */
372     int
373 skip_expr(char_u **pp)
374 {
375     typval_T	rettv;
376 
377     *pp = skipwhite(*pp);
378     return eval1(pp, &rettv, NULL);
379 }
380 
381 /*
382  * Skip over an expression at "*pp".
383  * If in Vim9 script and line breaks are encountered, the lines are
384  * concatenated.  "evalarg->eval_tofree" will be set accordingly.
385  * "arg" is advanced to just after the expression.
386  * "start" is set to the start of the expression, "end" to just after the end.
387  * Also when the expression is copied to allocated memory.
388  * Return FAIL for an error, OK otherwise.
389  */
390     int
391 skip_expr_concatenate(
392 	char_u	    **arg,
393 	char_u	    **start,
394 	char_u	    **end,
395 	evalarg_T   *evalarg)
396 {
397     typval_T	rettv;
398     int		res;
399     int		vim9script = in_vim9script();
400     garray_T    *gap = &evalarg->eval_ga;
401     int		save_flags = evalarg == NULL ? 0 : evalarg->eval_flags;
402 
403     if (vim9script
404 	       && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
405     {
406 	ga_init2(gap, sizeof(char_u *), 10);
407 	// leave room for "start"
408 	if (ga_grow(gap, 1) == OK)
409 	    ++gap->ga_len;
410     }
411     *start = *arg;
412 
413     // Don't evaluate the expression.
414     if (evalarg != NULL)
415 	evalarg->eval_flags &= ~EVAL_EVALUATE;
416     *arg = skipwhite(*arg);
417     res = eval1(arg, &rettv, evalarg);
418     *end = *arg;
419     if (evalarg != NULL)
420 	evalarg->eval_flags = save_flags;
421 
422     if (vim9script
423 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
424     {
425 	if (evalarg->eval_ga.ga_len == 1)
426 	{
427 	    // just one line, no need to concatenate
428 	    ga_clear(gap);
429 	    gap->ga_itemsize = 0;
430 	}
431 	else
432 	{
433 	    char_u	    *p;
434 	    size_t	    endoff = STRLEN(*arg);
435 
436 	    // Line breaks encountered, concatenate all the lines.
437 	    *((char_u **)gap->ga_data) = *start;
438 	    p = ga_concat_strings(gap, "");
439 
440 	    // free the lines only when using getsourceline()
441 	    if (evalarg->eval_cookie != NULL)
442 	    {
443 		// Do not free the first line, the caller can still use it.
444 		*((char_u **)gap->ga_data) = NULL;
445 		// Do not free the last line, "arg" points into it, free it
446 		// later.
447 		vim_free(evalarg->eval_tofree);
448 		evalarg->eval_tofree =
449 				    ((char_u **)gap->ga_data)[gap->ga_len - 1];
450 		((char_u **)gap->ga_data)[gap->ga_len - 1] = NULL;
451 		ga_clear_strings(gap);
452 	    }
453 	    else
454 		ga_clear(gap);
455 	    gap->ga_itemsize = 0;
456 	    if (p == NULL)
457 		return FAIL;
458 	    *start = p;
459 	    vim_free(evalarg->eval_tofree_lambda);
460 	    evalarg->eval_tofree_lambda = p;
461 	    // Compute "end" relative to the end.
462 	    *end = *start + STRLEN(*start) - endoff;
463 	}
464     }
465 
466     return res;
467 }
468 
469 /*
470  * Top level evaluation function, returning a string.  Does not handle line
471  * breaks.
472  * When "convert" is TRUE convert a List into a sequence of lines and convert
473  * a Float to a String.
474  * Return pointer to allocated memory, or NULL for failure.
475  */
476     char_u *
477 eval_to_string(
478     char_u	*arg,
479     int		convert)
480 {
481     typval_T	tv;
482     char_u	*retval;
483     garray_T	ga;
484 #ifdef FEAT_FLOAT
485     char_u	numbuf[NUMBUFLEN];
486 #endif
487 
488     if (eval0(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
489 	retval = NULL;
490     else
491     {
492 	if (convert && tv.v_type == VAR_LIST)
493 	{
494 	    ga_init2(&ga, (int)sizeof(char), 80);
495 	    if (tv.vval.v_list != NULL)
496 	    {
497 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
498 		if (tv.vval.v_list->lv_len > 0)
499 		    ga_append(&ga, NL);
500 	    }
501 	    ga_append(&ga, NUL);
502 	    retval = (char_u *)ga.ga_data;
503 	}
504 #ifdef FEAT_FLOAT
505 	else if (convert && tv.v_type == VAR_FLOAT)
506 	{
507 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
508 	    retval = vim_strsave(numbuf);
509 	}
510 #endif
511 	else
512 	    retval = vim_strsave(tv_get_string(&tv));
513 	clear_tv(&tv);
514     }
515     clear_evalarg(&EVALARG_EVALUATE, NULL);
516 
517     return retval;
518 }
519 
520 /*
521  * Call eval_to_string() without using current local variables and using
522  * textwinlock.  When "use_sandbox" is TRUE use the sandbox.
523  */
524     char_u *
525 eval_to_string_safe(
526     char_u	*arg,
527     int		use_sandbox)
528 {
529     char_u	*retval;
530     funccal_entry_T funccal_entry;
531 
532     save_funccal(&funccal_entry);
533     if (use_sandbox)
534 	++sandbox;
535     ++textwinlock;
536     retval = eval_to_string(arg, FALSE);
537     if (use_sandbox)
538 	--sandbox;
539     --textwinlock;
540     restore_funccal();
541     return retval;
542 }
543 
544 /*
545  * Top level evaluation function, returning a number.
546  * Evaluates "expr" silently.
547  * Returns -1 for an error.
548  */
549     varnumber_T
550 eval_to_number(char_u *expr)
551 {
552     typval_T	rettv;
553     varnumber_T	retval;
554     char_u	*p = skipwhite(expr);
555 
556     ++emsg_off;
557 
558     if (eval1(&p, &rettv, &EVALARG_EVALUATE) == FAIL)
559 	retval = -1;
560     else
561     {
562 	retval = tv_get_number_chk(&rettv, NULL);
563 	clear_tv(&rettv);
564     }
565     --emsg_off;
566 
567     return retval;
568 }
569 
570 /*
571  * Top level evaluation function.
572  * Returns an allocated typval_T with the result.
573  * Returns NULL when there is an error.
574  */
575     typval_T *
576 eval_expr(char_u *arg, exarg_T *eap)
577 {
578     typval_T	*tv;
579     evalarg_T	evalarg;
580 
581     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
582 
583     tv = ALLOC_ONE(typval_T);
584     if (tv != NULL && eval0(arg, tv, eap, &evalarg) == FAIL)
585 	VIM_CLEAR(tv);
586 
587     clear_evalarg(&evalarg, eap);
588     return tv;
589 }
590 
591 /*
592  * Call some Vim script function and return the result in "*rettv".
593  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
594  * should have type VAR_UNKNOWN.
595  * Returns OK or FAIL.
596  */
597     int
598 call_vim_function(
599     char_u      *func,
600     int		argc,
601     typval_T	*argv,
602     typval_T	*rettv)
603 {
604     int		ret;
605     funcexe_T	funcexe;
606 
607     rettv->v_type = VAR_UNKNOWN;		// clear_tv() uses this
608     CLEAR_FIELD(funcexe);
609     funcexe.firstline = curwin->w_cursor.lnum;
610     funcexe.lastline = curwin->w_cursor.lnum;
611     funcexe.evaluate = TRUE;
612     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
613     if (ret == FAIL)
614 	clear_tv(rettv);
615 
616     return ret;
617 }
618 
619 /*
620  * Call Vim script function "func" and return the result as a number.
621  * Returns -1 when calling the function fails.
622  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
623  * have type VAR_UNKNOWN.
624  */
625     varnumber_T
626 call_func_retnr(
627     char_u      *func,
628     int		argc,
629     typval_T	*argv)
630 {
631     typval_T	rettv;
632     varnumber_T	retval;
633 
634     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
635 	return -1;
636 
637     retval = tv_get_number_chk(&rettv, NULL);
638     clear_tv(&rettv);
639     return retval;
640 }
641 
642 /*
643  * Call Vim script function "func" and return the result as a string.
644  * Returns NULL when calling the function fails.
645  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
646  * have type VAR_UNKNOWN.
647  */
648     void *
649 call_func_retstr(
650     char_u      *func,
651     int		argc,
652     typval_T	*argv)
653 {
654     typval_T	rettv;
655     char_u	*retval;
656 
657     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
658 	return NULL;
659 
660     retval = vim_strsave(tv_get_string(&rettv));
661     clear_tv(&rettv);
662     return retval;
663 }
664 
665 /*
666  * Call Vim script function "func" and return the result as a List.
667  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
668  * have type VAR_UNKNOWN.
669  * Returns NULL when there is something wrong.
670  */
671     void *
672 call_func_retlist(
673     char_u      *func,
674     int		argc,
675     typval_T	*argv)
676 {
677     typval_T	rettv;
678 
679     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
680 	return NULL;
681 
682     if (rettv.v_type != VAR_LIST)
683     {
684 	clear_tv(&rettv);
685 	return NULL;
686     }
687 
688     return rettv.vval.v_list;
689 }
690 
691 #ifdef FEAT_FOLDING
692 /*
693  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
694  * it in "*cp".  Doesn't give error messages.
695  */
696     int
697 eval_foldexpr(char_u *arg, int *cp)
698 {
699     typval_T	tv;
700     varnumber_T	retval;
701     char_u	*s;
702     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
703 								   OPT_LOCAL);
704 
705     ++emsg_off;
706     if (use_sandbox)
707 	++sandbox;
708     ++textwinlock;
709     *cp = NUL;
710     if (eval0(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
711 	retval = 0;
712     else
713     {
714 	// If the result is a number, just return the number.
715 	if (tv.v_type == VAR_NUMBER)
716 	    retval = tv.vval.v_number;
717 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
718 	    retval = 0;
719 	else
720 	{
721 	    // If the result is a string, check if there is a non-digit before
722 	    // the number.
723 	    s = tv.vval.v_string;
724 	    if (!VIM_ISDIGIT(*s) && *s != '-')
725 		*cp = *s++;
726 	    retval = atol((char *)s);
727 	}
728 	clear_tv(&tv);
729     }
730     --emsg_off;
731     if (use_sandbox)
732 	--sandbox;
733     --textwinlock;
734     clear_evalarg(&EVALARG_EVALUATE, NULL);
735 
736     return (int)retval;
737 }
738 #endif
739 
740 /*
741  * Get an lval: variable, Dict item or List item that can be assigned a value
742  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
743  * "name.key", "name.key[expr]" etc.
744  * Indexing only works if "name" is an existing List or Dictionary.
745  * "name" points to the start of the name.
746  * If "rettv" is not NULL it points to the value to be assigned.
747  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
748  * wrong; must end in space or cmd separator.
749  *
750  * flags:
751  *  GLV_QUIET:       do not give error messages
752  *  GLV_READ_ONLY:   will not change the variable
753  *  GLV_NO_AUTOLOAD: do not use script autoloading
754  *
755  * Returns a pointer to just after the name, including indexes.
756  * When an evaluation error occurs "lp->ll_name" is NULL;
757  * Returns NULL for a parsing error.  Still need to free items in "lp"!
758  */
759     char_u *
760 get_lval(
761     char_u	*name,
762     typval_T	*rettv,
763     lval_T	*lp,
764     int		unlet,
765     int		skip,
766     int		flags,	    // GLV_ values
767     int		fne_flags)  // flags for find_name_end()
768 {
769     char_u	*p;
770     char_u	*expr_start, *expr_end;
771     int		cc;
772     dictitem_T	*v;
773     typval_T	var1;
774     typval_T	var2;
775     int		empty1 = FALSE;
776     listitem_T	*ni;
777     char_u	*key = NULL;
778     int		len;
779     hashtab_T	*ht;
780     int		quiet = flags & GLV_QUIET;
781 
782     // Clear everything in "lp".
783     CLEAR_POINTER(lp);
784 
785     if (skip)
786     {
787 	// When skipping just find the end of the name.
788 	lp->ll_name = name;
789 	lp->ll_name_end = find_name_end(name, NULL, NULL,
790 						      FNE_INCL_BR | fne_flags);
791 	return lp->ll_name_end;
792     }
793 
794     // Find the end of the name.
795     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
796     lp->ll_name_end = p;
797     if (expr_start != NULL)
798     {
799 	// Don't expand the name when we already know there is an error.
800 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
801 						    && *p != '[' && *p != '.')
802 	{
803 	    semsg(_(e_trailing_arg), p);
804 	    return NULL;
805 	}
806 
807 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
808 	if (lp->ll_exp_name == NULL)
809 	{
810 	    // Report an invalid expression in braces, unless the
811 	    // expression evaluation has been cancelled due to an
812 	    // aborting error, an interrupt, or an exception.
813 	    if (!aborting() && !quiet)
814 	    {
815 		emsg_severe = TRUE;
816 		semsg(_(e_invarg2), name);
817 		return NULL;
818 	    }
819 	}
820 	lp->ll_name = lp->ll_exp_name;
821     }
822     else
823     {
824 	lp->ll_name = name;
825 
826 	if (in_vim9script())
827 	{
828 	    // "a: type" is declaring variable "a" with a type, not "a:".
829 	    if (p == name + 2 && p[-1] == ':')
830 	    {
831 		--p;
832 		lp->ll_name_end = p;
833 	    }
834 	    if (*p == ':')
835 	    {
836 		scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);
837 		char_u	 *tp = skipwhite(p + 1);
838 
839 		// parse the type after the name
840 		lp->ll_type = parse_type(&tp, &si->sn_type_list);
841 		lp->ll_name_end = tp;
842 	    }
843 	}
844     }
845 
846     // Without [idx] or .key we are done.
847     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
848 	return p;
849 
850     cc = *p;
851     *p = NUL;
852     // Only pass &ht when we would write to the variable, it prevents autoload
853     // as well.
854     v = find_var(lp->ll_name, (flags & GLV_READ_ONLY) ? NULL : &ht,
855 						      flags & GLV_NO_AUTOLOAD);
856     if (v == NULL && !quiet)
857 	semsg(_(e_undefvar), lp->ll_name);
858     *p = cc;
859     if (v == NULL)
860 	return NULL;
861 
862     /*
863      * Loop until no more [idx] or .key is following.
864      */
865     lp->ll_tv = &v->di_tv;
866     var1.v_type = VAR_UNKNOWN;
867     var2.v_type = VAR_UNKNOWN;
868     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
869     {
870 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
871 		&& !(lp->ll_tv->v_type == VAR_DICT
872 					   && lp->ll_tv->vval.v_dict != NULL)
873 		&& !(lp->ll_tv->v_type == VAR_BLOB
874 					   && lp->ll_tv->vval.v_blob != NULL))
875 	{
876 	    if (!quiet)
877 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
878 	    return NULL;
879 	}
880 	if (lp->ll_range)
881 	{
882 	    if (!quiet)
883 		emsg(_("E708: [:] must come last"));
884 	    return NULL;
885 	}
886 
887 	len = -1;
888 	if (*p == '.')
889 	{
890 	    key = p + 1;
891 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
892 		;
893 	    if (len == 0)
894 	    {
895 		if (!quiet)
896 		    emsg(_(e_emptykey));
897 		return NULL;
898 	    }
899 	    p = key + len;
900 	}
901 	else
902 	{
903 	    // Get the index [expr] or the first index [expr: ].
904 	    p = skipwhite(p + 1);
905 	    if (*p == ':')
906 		empty1 = TRUE;
907 	    else
908 	    {
909 		empty1 = FALSE;
910 		if (eval1(&p, &var1, &EVALARG_EVALUATE) == FAIL)  // recursive!
911 		    return NULL;
912 		if (tv_get_string_chk(&var1) == NULL)
913 		{
914 		    // not a number or string
915 		    clear_tv(&var1);
916 		    return NULL;
917 		}
918 		p = skipwhite(p);
919 	    }
920 
921 	    // Optionally get the second index [ :expr].
922 	    if (*p == ':')
923 	    {
924 		if (lp->ll_tv->v_type == VAR_DICT)
925 		{
926 		    if (!quiet)
927 			emsg(_(e_dictrange));
928 		    clear_tv(&var1);
929 		    return NULL;
930 		}
931 		if (rettv != NULL
932 			&& !(rettv->v_type == VAR_LIST
933 						 && rettv->vval.v_list != NULL)
934 			&& !(rettv->v_type == VAR_BLOB
935 						&& rettv->vval.v_blob != NULL))
936 		{
937 		    if (!quiet)
938 			emsg(_("E709: [:] requires a List or Blob value"));
939 		    clear_tv(&var1);
940 		    return NULL;
941 		}
942 		p = skipwhite(p + 1);
943 		if (*p == ']')
944 		    lp->ll_empty2 = TRUE;
945 		else
946 		{
947 		    lp->ll_empty2 = FALSE;
948 		    // recursive!
949 		    if (eval1(&p, &var2, &EVALARG_EVALUATE) == FAIL)
950 		    {
951 			clear_tv(&var1);
952 			return NULL;
953 		    }
954 		    if (tv_get_string_chk(&var2) == NULL)
955 		    {
956 			// not a number or string
957 			clear_tv(&var1);
958 			clear_tv(&var2);
959 			return NULL;
960 		    }
961 		}
962 		lp->ll_range = TRUE;
963 	    }
964 	    else
965 		lp->ll_range = FALSE;
966 
967 	    if (*p != ']')
968 	    {
969 		if (!quiet)
970 		    emsg(_(e_missbrac));
971 		clear_tv(&var1);
972 		clear_tv(&var2);
973 		return NULL;
974 	    }
975 
976 	    // Skip to past ']'.
977 	    ++p;
978 	}
979 
980 	if (lp->ll_tv->v_type == VAR_DICT)
981 	{
982 	    if (len == -1)
983 	    {
984 		// "[key]": get key from "var1"
985 		key = tv_get_string_chk(&var1);	// is number or string
986 		if (key == NULL)
987 		{
988 		    clear_tv(&var1);
989 		    return NULL;
990 		}
991 	    }
992 	    lp->ll_list = NULL;
993 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
994 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
995 
996 	    // When assigning to a scope dictionary check that a function and
997 	    // variable name is valid (only variable name unless it is l: or
998 	    // g: dictionary). Disallow overwriting a builtin function.
999 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
1000 	    {
1001 		int prevval;
1002 		int wrong;
1003 
1004 		if (len != -1)
1005 		{
1006 		    prevval = key[len];
1007 		    key[len] = NUL;
1008 		}
1009 		else
1010 		    prevval = 0; // avoid compiler warning
1011 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
1012 			       && rettv->v_type == VAR_FUNC
1013 			       && var_wrong_func_name(key, lp->ll_di == NULL))
1014 			|| !valid_varname(key);
1015 		if (len != -1)
1016 		    key[len] = prevval;
1017 		if (wrong)
1018 		{
1019 		    clear_tv(&var1);
1020 		    return NULL;
1021 		}
1022 	    }
1023 
1024 	    if (lp->ll_di == NULL)
1025 	    {
1026 		// Can't add "v:" or "a:" variable.
1027 		if (lp->ll_dict == get_vimvar_dict()
1028 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
1029 		{
1030 		    semsg(_(e_illvar), name);
1031 		    clear_tv(&var1);
1032 		    return NULL;
1033 		}
1034 
1035 		// Key does not exist in dict: may need to add it.
1036 		if (*p == '[' || *p == '.' || unlet)
1037 		{
1038 		    if (!quiet)
1039 			semsg(_(e_dictkey), key);
1040 		    clear_tv(&var1);
1041 		    return NULL;
1042 		}
1043 		if (len == -1)
1044 		    lp->ll_newkey = vim_strsave(key);
1045 		else
1046 		    lp->ll_newkey = vim_strnsave(key, len);
1047 		clear_tv(&var1);
1048 		if (lp->ll_newkey == NULL)
1049 		    p = NULL;
1050 		break;
1051 	    }
1052 	    // existing variable, need to check if it can be changed
1053 	    else if ((flags & GLV_READ_ONLY) == 0
1054 			     && var_check_ro(lp->ll_di->di_flags, name, FALSE))
1055 	    {
1056 		clear_tv(&var1);
1057 		return NULL;
1058 	    }
1059 
1060 	    clear_tv(&var1);
1061 	    lp->ll_tv = &lp->ll_di->di_tv;
1062 	}
1063 	else if (lp->ll_tv->v_type == VAR_BLOB)
1064 	{
1065 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
1066 
1067 	    /*
1068 	     * Get the number and item for the only or first index of the List.
1069 	     */
1070 	    if (empty1)
1071 		lp->ll_n1 = 0;
1072 	    else
1073 		// is number or string
1074 		lp->ll_n1 = (long)tv_get_number(&var1);
1075 	    clear_tv(&var1);
1076 
1077 	    if (lp->ll_n1 < 0
1078 		    || lp->ll_n1 > bloblen
1079 		    || (lp->ll_range && lp->ll_n1 == bloblen))
1080 	    {
1081 		if (!quiet)
1082 		    semsg(_(e_blobidx), lp->ll_n1);
1083 		clear_tv(&var2);
1084 		return NULL;
1085 	    }
1086 	    if (lp->ll_range && !lp->ll_empty2)
1087 	    {
1088 		lp->ll_n2 = (long)tv_get_number(&var2);
1089 		clear_tv(&var2);
1090 		if (lp->ll_n2 < 0
1091 			|| lp->ll_n2 >= bloblen
1092 			|| lp->ll_n2 < lp->ll_n1)
1093 		{
1094 		    if (!quiet)
1095 			semsg(_(e_blobidx), lp->ll_n2);
1096 		    return NULL;
1097 		}
1098 	    }
1099 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
1100 	    lp->ll_tv = NULL;
1101 	    break;
1102 	}
1103 	else
1104 	{
1105 	    /*
1106 	     * Get the number and item for the only or first index of the List.
1107 	     */
1108 	    if (empty1)
1109 		lp->ll_n1 = 0;
1110 	    else
1111 		// is number or string
1112 		lp->ll_n1 = (long)tv_get_number(&var1);
1113 	    clear_tv(&var1);
1114 
1115 	    lp->ll_dict = NULL;
1116 	    lp->ll_list = lp->ll_tv->vval.v_list;
1117 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
1118 	    if (lp->ll_li == NULL)
1119 	    {
1120 		if (lp->ll_n1 < 0)
1121 		{
1122 		    lp->ll_n1 = 0;
1123 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
1124 		}
1125 	    }
1126 	    if (lp->ll_li == NULL)
1127 	    {
1128 		clear_tv(&var2);
1129 		if (!quiet)
1130 		    semsg(_(e_listidx), lp->ll_n1);
1131 		return NULL;
1132 	    }
1133 
1134 	    /*
1135 	     * May need to find the item or absolute index for the second
1136 	     * index of a range.
1137 	     * When no index given: "lp->ll_empty2" is TRUE.
1138 	     * Otherwise "lp->ll_n2" is set to the second index.
1139 	     */
1140 	    if (lp->ll_range && !lp->ll_empty2)
1141 	    {
1142 		lp->ll_n2 = (long)tv_get_number(&var2);
1143 						    // is number or string
1144 		clear_tv(&var2);
1145 		if (lp->ll_n2 < 0)
1146 		{
1147 		    ni = list_find(lp->ll_list, lp->ll_n2);
1148 		    if (ni == NULL)
1149 		    {
1150 			if (!quiet)
1151 			    semsg(_(e_listidx), lp->ll_n2);
1152 			return NULL;
1153 		    }
1154 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
1155 		}
1156 
1157 		// Check that lp->ll_n2 isn't before lp->ll_n1.
1158 		if (lp->ll_n1 < 0)
1159 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
1160 		if (lp->ll_n2 < lp->ll_n1)
1161 		{
1162 		    if (!quiet)
1163 			semsg(_(e_listidx), lp->ll_n2);
1164 		    return NULL;
1165 		}
1166 	    }
1167 
1168 	    lp->ll_tv = &lp->ll_li->li_tv;
1169 	}
1170     }
1171 
1172     clear_tv(&var1);
1173     lp->ll_name_end = p;
1174     return p;
1175 }
1176 
1177 /*
1178  * Clear lval "lp" that was filled by get_lval().
1179  */
1180     void
1181 clear_lval(lval_T *lp)
1182 {
1183     vim_free(lp->ll_exp_name);
1184     vim_free(lp->ll_newkey);
1185 }
1186 
1187 /*
1188  * Set a variable that was parsed by get_lval() to "rettv".
1189  * "endp" points to just after the parsed name.
1190  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
1191  * "%" for "%=", "." for ".=" or "=" for "=".
1192  */
1193     void
1194 set_var_lval(
1195     lval_T	*lp,
1196     char_u	*endp,
1197     typval_T	*rettv,
1198     int		copy,
1199     int		flags,    // LET_IS_CONST and/or LET_NO_COMMAND
1200     char_u	*op)
1201 {
1202     int		cc;
1203     listitem_T	*ri;
1204     dictitem_T	*di;
1205 
1206     if (lp->ll_tv == NULL)
1207     {
1208 	cc = *endp;
1209 	*endp = NUL;
1210 	if (lp->ll_blob != NULL)
1211 	{
1212 	    int	    error = FALSE, val;
1213 
1214 	    if (op != NULL && *op != '=')
1215 	    {
1216 		semsg(_(e_letwrong), op);
1217 		return;
1218 	    }
1219 
1220 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
1221 	    {
1222 		int	il, ir;
1223 
1224 		if (lp->ll_empty2)
1225 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
1226 
1227 		if (lp->ll_n2 - lp->ll_n1 + 1 != blob_len(rettv->vval.v_blob))
1228 		{
1229 		    emsg(_("E972: Blob value does not have the right number of bytes"));
1230 		    return;
1231 		}
1232 		if (lp->ll_empty2)
1233 		    lp->ll_n2 = blob_len(lp->ll_blob);
1234 
1235 		ir = 0;
1236 		for (il = lp->ll_n1; il <= lp->ll_n2; il++)
1237 		    blob_set(lp->ll_blob, il,
1238 			    blob_get(rettv->vval.v_blob, ir++));
1239 	    }
1240 	    else
1241 	    {
1242 		val = (int)tv_get_number_chk(rettv, &error);
1243 		if (!error)
1244 		{
1245 		    garray_T *gap = &lp->ll_blob->bv_ga;
1246 
1247 		    // Allow for appending a byte.  Setting a byte beyond
1248 		    // the end is an error otherwise.
1249 		    if (lp->ll_n1 < gap->ga_len
1250 			    || (lp->ll_n1 == gap->ga_len
1251 				&& ga_grow(&lp->ll_blob->bv_ga, 1) == OK))
1252 		    {
1253 			blob_set(lp->ll_blob, lp->ll_n1, val);
1254 			if (lp->ll_n1 == gap->ga_len)
1255 			    ++gap->ga_len;
1256 		    }
1257 		    // error for invalid range was already given in get_lval()
1258 		}
1259 	    }
1260 	}
1261 	else if (op != NULL && *op != '=')
1262 	{
1263 	    typval_T tv;
1264 
1265 	    if (flags & LET_IS_CONST)
1266 	    {
1267 		emsg(_(e_cannot_mod));
1268 		*endp = cc;
1269 		return;
1270 	    }
1271 
1272 	    // handle +=, -=, *=, /=, %= and .=
1273 	    di = NULL;
1274 	    if (eval_variable(lp->ll_name, (int)STRLEN(lp->ll_name),
1275 					     &tv, &di, TRUE, FALSE) == OK)
1276 	    {
1277 		if ((di == NULL
1278 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
1279 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
1280 			&& tv_op(&tv, rettv, op) == OK)
1281 		    set_var(lp->ll_name, &tv, FALSE);
1282 		clear_tv(&tv);
1283 	    }
1284 	}
1285 	else
1286 	{
1287 	    if (lp->ll_type != NULL
1288 			      && check_typval_type(lp->ll_type, rettv) == FAIL)
1289 		return;
1290 	    set_var_const(lp->ll_name, lp->ll_type, rettv, copy, flags);
1291 	}
1292 	*endp = cc;
1293     }
1294     else if (var_check_lock(lp->ll_newkey == NULL
1295 		? lp->ll_tv->v_lock
1296 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
1297 	;
1298     else if (lp->ll_range)
1299     {
1300 	listitem_T *ll_li = lp->ll_li;
1301 	int	    ll_n1 = lp->ll_n1;
1302 
1303 	if (flags & LET_IS_CONST)
1304 	{
1305 	    emsg(_("E996: Cannot lock a range"));
1306 	    return;
1307 	}
1308 
1309 	/*
1310 	 * Check whether any of the list items is locked
1311 	 */
1312 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
1313 	{
1314 	    if (var_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
1315 		return;
1316 	    ri = ri->li_next;
1317 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
1318 		break;
1319 	    ll_li = ll_li->li_next;
1320 	    ++ll_n1;
1321 	}
1322 
1323 	/*
1324 	 * Assign the List values to the list items.
1325 	 */
1326 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
1327 	{
1328 	    if (op != NULL && *op != '=')
1329 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
1330 	    else
1331 	    {
1332 		clear_tv(&lp->ll_li->li_tv);
1333 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
1334 	    }
1335 	    ri = ri->li_next;
1336 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
1337 		break;
1338 	    if (lp->ll_li->li_next == NULL)
1339 	    {
1340 		// Need to add an empty item.
1341 		if (list_append_number(lp->ll_list, 0) == FAIL)
1342 		{
1343 		    ri = NULL;
1344 		    break;
1345 		}
1346 	    }
1347 	    lp->ll_li = lp->ll_li->li_next;
1348 	    ++lp->ll_n1;
1349 	}
1350 	if (ri != NULL)
1351 	    emsg(_("E710: List value has more items than target"));
1352 	else if (lp->ll_empty2
1353 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
1354 		: lp->ll_n1 != lp->ll_n2)
1355 	    emsg(_("E711: List value has not enough items"));
1356     }
1357     else
1358     {
1359 	/*
1360 	 * Assign to a List or Dictionary item.
1361 	 */
1362 	if (flags & LET_IS_CONST)
1363 	{
1364 	    emsg(_("E996: Cannot lock a list or dict"));
1365 	    return;
1366 	}
1367 	if (lp->ll_newkey != NULL)
1368 	{
1369 	    if (op != NULL && *op != '=')
1370 	    {
1371 		semsg(_(e_letwrong), op);
1372 		return;
1373 	    }
1374 
1375 	    // Need to add an item to the Dictionary.
1376 	    di = dictitem_alloc(lp->ll_newkey);
1377 	    if (di == NULL)
1378 		return;
1379 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
1380 	    {
1381 		vim_free(di);
1382 		return;
1383 	    }
1384 	    lp->ll_tv = &di->di_tv;
1385 	}
1386 	else if (op != NULL && *op != '=')
1387 	{
1388 	    tv_op(lp->ll_tv, rettv, op);
1389 	    return;
1390 	}
1391 	else
1392 	    clear_tv(lp->ll_tv);
1393 
1394 	/*
1395 	 * Assign the value to the variable or list item.
1396 	 */
1397 	if (copy)
1398 	    copy_tv(rettv, lp->ll_tv);
1399 	else
1400 	{
1401 	    *lp->ll_tv = *rettv;
1402 	    lp->ll_tv->v_lock = 0;
1403 	    init_tv(rettv);
1404 	}
1405     }
1406 }
1407 
1408 /*
1409  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
1410  * and "tv1 .= tv2"
1411  * Returns OK or FAIL.
1412  */
1413     static int
1414 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
1415 {
1416     varnumber_T	n;
1417     char_u	numbuf[NUMBUFLEN];
1418     char_u	*s;
1419 
1420     // Can't do anything with a Funcref, Dict, v:true on the right.
1421     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
1422 		      && tv2->v_type != VAR_BOOL && tv2->v_type != VAR_SPECIAL)
1423     {
1424 	switch (tv1->v_type)
1425 	{
1426 	    case VAR_UNKNOWN:
1427 	    case VAR_ANY:
1428 	    case VAR_VOID:
1429 	    case VAR_DICT:
1430 	    case VAR_FUNC:
1431 	    case VAR_PARTIAL:
1432 	    case VAR_BOOL:
1433 	    case VAR_SPECIAL:
1434 	    case VAR_JOB:
1435 	    case VAR_CHANNEL:
1436 		break;
1437 
1438 	    case VAR_BLOB:
1439 		if (*op != '+' || tv2->v_type != VAR_BLOB)
1440 		    break;
1441 		// BLOB += BLOB
1442 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
1443 		{
1444 		    blob_T  *b1 = tv1->vval.v_blob;
1445 		    blob_T  *b2 = tv2->vval.v_blob;
1446 		    int	i, len = blob_len(b2);
1447 		    for (i = 0; i < len; i++)
1448 			ga_append(&b1->bv_ga, blob_get(b2, i));
1449 		}
1450 		return OK;
1451 
1452 	    case VAR_LIST:
1453 		if (*op != '+' || tv2->v_type != VAR_LIST)
1454 		    break;
1455 		// List += List
1456 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
1457 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
1458 		return OK;
1459 
1460 	    case VAR_NUMBER:
1461 	    case VAR_STRING:
1462 		if (tv2->v_type == VAR_LIST)
1463 		    break;
1464 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
1465 		{
1466 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
1467 		    n = tv_get_number(tv1);
1468 #ifdef FEAT_FLOAT
1469 		    if (tv2->v_type == VAR_FLOAT)
1470 		    {
1471 			float_T f = n;
1472 
1473 			if (*op == '%')
1474 			    break;
1475 			switch (*op)
1476 			{
1477 			    case '+': f += tv2->vval.v_float; break;
1478 			    case '-': f -= tv2->vval.v_float; break;
1479 			    case '*': f *= tv2->vval.v_float; break;
1480 			    case '/': f /= tv2->vval.v_float; break;
1481 			}
1482 			clear_tv(tv1);
1483 			tv1->v_type = VAR_FLOAT;
1484 			tv1->vval.v_float = f;
1485 		    }
1486 		    else
1487 #endif
1488 		    {
1489 			switch (*op)
1490 			{
1491 			    case '+': n += tv_get_number(tv2); break;
1492 			    case '-': n -= tv_get_number(tv2); break;
1493 			    case '*': n *= tv_get_number(tv2); break;
1494 			    case '/': n = num_divide(n, tv_get_number(tv2)); break;
1495 			    case '%': n = num_modulus(n, tv_get_number(tv2)); break;
1496 			}
1497 			clear_tv(tv1);
1498 			tv1->v_type = VAR_NUMBER;
1499 			tv1->vval.v_number = n;
1500 		    }
1501 		}
1502 		else
1503 		{
1504 		    if (tv2->v_type == VAR_FLOAT)
1505 			break;
1506 
1507 		    // str .= str
1508 		    s = tv_get_string(tv1);
1509 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
1510 		    clear_tv(tv1);
1511 		    tv1->v_type = VAR_STRING;
1512 		    tv1->vval.v_string = s;
1513 		}
1514 		return OK;
1515 
1516 	    case VAR_FLOAT:
1517 #ifdef FEAT_FLOAT
1518 		{
1519 		    float_T f;
1520 
1521 		    if (*op == '%' || *op == '.'
1522 				   || (tv2->v_type != VAR_FLOAT
1523 				    && tv2->v_type != VAR_NUMBER
1524 				    && tv2->v_type != VAR_STRING))
1525 			break;
1526 		    if (tv2->v_type == VAR_FLOAT)
1527 			f = tv2->vval.v_float;
1528 		    else
1529 			f = tv_get_number(tv2);
1530 		    switch (*op)
1531 		    {
1532 			case '+': tv1->vval.v_float += f; break;
1533 			case '-': tv1->vval.v_float -= f; break;
1534 			case '*': tv1->vval.v_float *= f; break;
1535 			case '/': tv1->vval.v_float /= f; break;
1536 		    }
1537 		}
1538 #endif
1539 		return OK;
1540 	}
1541     }
1542 
1543     semsg(_(e_letwrong), op);
1544     return FAIL;
1545 }
1546 
1547 /*
1548  * Evaluate the expression used in a ":for var in expr" command.
1549  * "arg" points to "var".
1550  * Set "*errp" to TRUE for an error, FALSE otherwise;
1551  * Return a pointer that holds the info.  Null when there is an error.
1552  */
1553     void *
1554 eval_for_line(
1555     char_u	*arg,
1556     int		*errp,
1557     exarg_T	*eap,
1558     evalarg_T	*evalarg)
1559 {
1560     forinfo_T	*fi;
1561     char_u	*expr;
1562     typval_T	tv;
1563     list_T	*l;
1564     int		skip = !(evalarg->eval_flags & EVAL_EVALUATE);
1565 
1566     *errp = TRUE;	// default: there is an error
1567 
1568     fi = ALLOC_CLEAR_ONE(forinfo_T);
1569     if (fi == NULL)
1570 	return NULL;
1571 
1572     expr = skip_var_list(arg, TRUE, &fi->fi_varcount, &fi->fi_semicolon, FALSE);
1573     if (expr == NULL)
1574 	return fi;
1575 
1576     expr = skipwhite_and_linebreak(expr, evalarg);
1577     if (expr[0] != 'i' || expr[1] != 'n'
1578 				  || !(expr[2] == NUL || VIM_ISWHITE(expr[2])))
1579     {
1580 	emsg(_(e_missing_in));
1581 	return fi;
1582     }
1583 
1584     if (skip)
1585 	++emsg_skip;
1586     expr = skipwhite_and_linebreak(expr + 2, evalarg);
1587     if (eval0(expr, &tv, eap, evalarg) == OK)
1588     {
1589 	*errp = FALSE;
1590 	if (!skip)
1591 	{
1592 	    if (tv.v_type == VAR_LIST)
1593 	    {
1594 		l = tv.vval.v_list;
1595 		if (l == NULL)
1596 		{
1597 		    // a null list is like an empty list: do nothing
1598 		    clear_tv(&tv);
1599 		}
1600 		else
1601 		{
1602 		    // Need a real list here.
1603 		    CHECK_LIST_MATERIALIZE(l);
1604 
1605 		    // No need to increment the refcount, it's already set for
1606 		    // the list being used in "tv".
1607 		    fi->fi_list = l;
1608 		    list_add_watch(l, &fi->fi_lw);
1609 		    fi->fi_lw.lw_item = l->lv_first;
1610 		}
1611 	    }
1612 	    else if (tv.v_type == VAR_BLOB)
1613 	    {
1614 		fi->fi_bi = 0;
1615 		if (tv.vval.v_blob != NULL)
1616 		{
1617 		    typval_T btv;
1618 
1619 		    // Make a copy, so that the iteration still works when the
1620 		    // blob is changed.
1621 		    blob_copy(tv.vval.v_blob, &btv);
1622 		    fi->fi_blob = btv.vval.v_blob;
1623 		}
1624 		clear_tv(&tv);
1625 	    }
1626 	    else
1627 	    {
1628 		emsg(_(e_listreq));
1629 		clear_tv(&tv);
1630 	    }
1631 	}
1632     }
1633     if (skip)
1634 	--emsg_skip;
1635     fi->fi_break_count = evalarg->eval_break_count;
1636 
1637     return fi;
1638 }
1639 
1640 /*
1641  * Used when looping over a :for line, skip the "in expr" part.
1642  */
1643     void
1644 skip_for_lines(void *fi_void, evalarg_T *evalarg)
1645 {
1646     forinfo_T	*fi = (forinfo_T *)fi_void;
1647     int		i;
1648 
1649     for (i = 0; i < fi->fi_break_count; ++i)
1650 	eval_next_line(evalarg);
1651 }
1652 
1653 /*
1654  * Use the first item in a ":for" list.  Advance to the next.
1655  * Assign the values to the variable (list).  "arg" points to the first one.
1656  * Return TRUE when a valid item was found, FALSE when at end of list or
1657  * something wrong.
1658  */
1659     int
1660 next_for_item(void *fi_void, char_u *arg)
1661 {
1662     forinfo_T	*fi = (forinfo_T *)fi_void;
1663     int		result;
1664     int		flag = in_vim9script() ?  LET_NO_COMMAND : 0;
1665     listitem_T	*item;
1666 
1667     if (fi->fi_blob != NULL)
1668     {
1669 	typval_T	tv;
1670 
1671 	if (fi->fi_bi >= blob_len(fi->fi_blob))
1672 	    return FALSE;
1673 	tv.v_type = VAR_NUMBER;
1674 	tv.v_lock = VAR_FIXED;
1675 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
1676 	++fi->fi_bi;
1677 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1678 				       fi->fi_varcount, flag, NULL) == OK;
1679     }
1680 
1681     item = fi->fi_lw.lw_item;
1682     if (item == NULL)
1683 	result = FALSE;
1684     else
1685     {
1686 	fi->fi_lw.lw_item = item->li_next;
1687 	result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
1688 				      fi->fi_varcount, flag, NULL) == OK);
1689     }
1690     return result;
1691 }
1692 
1693 /*
1694  * Free the structure used to store info used by ":for".
1695  */
1696     void
1697 free_for_info(void *fi_void)
1698 {
1699     forinfo_T    *fi = (forinfo_T *)fi_void;
1700 
1701     if (fi != NULL && fi->fi_list != NULL)
1702     {
1703 	list_rem_watch(fi->fi_list, &fi->fi_lw);
1704 	list_unref(fi->fi_list);
1705     }
1706     if (fi != NULL && fi->fi_blob != NULL)
1707 	blob_unref(fi->fi_blob);
1708     vim_free(fi);
1709 }
1710 
1711     void
1712 set_context_for_expression(
1713     expand_T	*xp,
1714     char_u	*arg,
1715     cmdidx_T	cmdidx)
1716 {
1717     int		got_eq = FALSE;
1718     int		c;
1719     char_u	*p;
1720 
1721     if (cmdidx == CMD_let || cmdidx == CMD_const)
1722     {
1723 	xp->xp_context = EXPAND_USER_VARS;
1724 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
1725 	{
1726 	    // ":let var1 var2 ...": find last space.
1727 	    for (p = arg + STRLEN(arg); p >= arg; )
1728 	    {
1729 		xp->xp_pattern = p;
1730 		MB_PTR_BACK(arg, p);
1731 		if (VIM_ISWHITE(*p))
1732 		    break;
1733 	    }
1734 	    return;
1735 	}
1736     }
1737     else
1738 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
1739 							  : EXPAND_EXPRESSION;
1740     while ((xp->xp_pattern = vim_strpbrk(arg,
1741 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
1742     {
1743 	c = *xp->xp_pattern;
1744 	if (c == '&')
1745 	{
1746 	    c = xp->xp_pattern[1];
1747 	    if (c == '&')
1748 	    {
1749 		++xp->xp_pattern;
1750 		xp->xp_context = cmdidx != CMD_let || got_eq
1751 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
1752 	    }
1753 	    else if (c != ' ')
1754 	    {
1755 		xp->xp_context = EXPAND_SETTINGS;
1756 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
1757 		    xp->xp_pattern += 2;
1758 
1759 	    }
1760 	}
1761 	else if (c == '$')
1762 	{
1763 	    // environment variable
1764 	    xp->xp_context = EXPAND_ENV_VARS;
1765 	}
1766 	else if (c == '=')
1767 	{
1768 	    got_eq = TRUE;
1769 	    xp->xp_context = EXPAND_EXPRESSION;
1770 	}
1771 	else if (c == '#'
1772 		&& xp->xp_context == EXPAND_EXPRESSION)
1773 	{
1774 	    // Autoload function/variable contains '#'.
1775 	    break;
1776 	}
1777 	else if ((c == '<' || c == '#')
1778 		&& xp->xp_context == EXPAND_FUNCTIONS
1779 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
1780 	{
1781 	    // Function name can start with "<SNR>" and contain '#'.
1782 	    break;
1783 	}
1784 	else if (cmdidx != CMD_let || got_eq)
1785 	{
1786 	    if (c == '"')	    // string
1787 	    {
1788 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
1789 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
1790 			++xp->xp_pattern;
1791 		xp->xp_context = EXPAND_NOTHING;
1792 	    }
1793 	    else if (c == '\'')	    // literal string
1794 	    {
1795 		// Trick: '' is like stopping and starting a literal string.
1796 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
1797 		    /* skip */ ;
1798 		xp->xp_context = EXPAND_NOTHING;
1799 	    }
1800 	    else if (c == '|')
1801 	    {
1802 		if (xp->xp_pattern[1] == '|')
1803 		{
1804 		    ++xp->xp_pattern;
1805 		    xp->xp_context = EXPAND_EXPRESSION;
1806 		}
1807 		else
1808 		    xp->xp_context = EXPAND_COMMANDS;
1809 	    }
1810 	    else
1811 		xp->xp_context = EXPAND_EXPRESSION;
1812 	}
1813 	else
1814 	    // Doesn't look like something valid, expand as an expression
1815 	    // anyway.
1816 	    xp->xp_context = EXPAND_EXPRESSION;
1817 	arg = xp->xp_pattern;
1818 	if (*arg != NUL)
1819 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
1820 		/* skip */ ;
1821     }
1822     xp->xp_pattern = arg;
1823 }
1824 
1825 /*
1826  * Return TRUE if "pat" matches "text".
1827  * Does not use 'cpo' and always uses 'magic'.
1828  */
1829     int
1830 pattern_match(char_u *pat, char_u *text, int ic)
1831 {
1832     int		matches = FALSE;
1833     char_u	*save_cpo;
1834     regmatch_T	regmatch;
1835 
1836     // avoid 'l' flag in 'cpoptions'
1837     save_cpo = p_cpo;
1838     p_cpo = (char_u *)"";
1839     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1840     if (regmatch.regprog != NULL)
1841     {
1842 	regmatch.rm_ic = ic;
1843 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
1844 	vim_regfree(regmatch.regprog);
1845     }
1846     p_cpo = save_cpo;
1847     return matches;
1848 }
1849 
1850 /*
1851  * Handle a name followed by "(".  Both for just "name(arg)" and for
1852  * "expr->name(arg)".
1853  * Returns OK or FAIL.
1854  */
1855     static int
1856 eval_func(
1857 	char_u	    **arg,	// points to "(", will be advanced
1858 	evalarg_T   *evalarg,
1859 	char_u	    *name,
1860 	int	    name_len,
1861 	typval_T    *rettv,
1862 	int	    flags,
1863 	typval_T    *basetv)	// "expr" for "expr->name(arg)"
1864 {
1865     int		evaluate = flags & EVAL_EVALUATE;
1866     char_u	*s = name;
1867     int		len = name_len;
1868     partial_T	*partial;
1869     int		ret = OK;
1870 
1871     if (!evaluate)
1872 	check_vars(s, len);
1873 
1874     // If "s" is the name of a variable of type VAR_FUNC
1875     // use its contents.
1876     s = deref_func_name(s, &len, &partial, !evaluate);
1877 
1878     // Need to make a copy, in case evaluating the arguments makes
1879     // the name invalid.
1880     s = vim_strsave(s);
1881     if (s == NULL || (flags & EVAL_CONSTANT))
1882 	ret = FAIL;
1883     else
1884     {
1885 	funcexe_T funcexe;
1886 
1887 	// Invoke the function.
1888 	CLEAR_FIELD(funcexe);
1889 	funcexe.firstline = curwin->w_cursor.lnum;
1890 	funcexe.lastline = curwin->w_cursor.lnum;
1891 	funcexe.evaluate = evaluate;
1892 	funcexe.partial = partial;
1893 	funcexe.basetv = basetv;
1894 	ret = get_func_tv(s, len, rettv, arg, evalarg, &funcexe);
1895     }
1896     vim_free(s);
1897 
1898     // If evaluate is FALSE rettv->v_type was not set in
1899     // get_func_tv, but it's needed in handle_subscript() to parse
1900     // what follows. So set it here.
1901     if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
1902     {
1903 	rettv->vval.v_string = NULL;
1904 	rettv->v_type = VAR_FUNC;
1905     }
1906 
1907     // Stop the expression evaluation when immediately
1908     // aborting on error, or when an interrupt occurred or
1909     // an exception was thrown but not caught.
1910     if (evaluate && aborting())
1911     {
1912 	if (ret == OK)
1913 	    clear_tv(rettv);
1914 	ret = FAIL;
1915     }
1916     return ret;
1917 }
1918 
1919 /*
1920  * If inside Vim9 script, "arg" points to the end of a line (ignoring a #
1921  * comment) and there is a next line, return the next line (skipping blanks)
1922  * and set "getnext".
1923  * Otherwise just return "arg" unmodified and set "getnext" to FALSE.
1924  * "arg" must point somewhere inside a line, not at the start.
1925  */
1926     char_u *
1927 eval_next_non_blank(char_u *arg, evalarg_T *evalarg, int *getnext)
1928 {
1929     char_u *p = skipwhite(arg);
1930 
1931     *getnext = FALSE;
1932     if (in_vim9script()
1933 	    && evalarg != NULL
1934 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL)
1935 	    && (*p == NUL || (VIM_ISWHITE(p[-1]) && vim9_comment_start(p))))
1936     {
1937 	char_u *next;
1938 
1939 	if (evalarg->eval_cookie != NULL)
1940 	    next = getline_peek(evalarg->eval_getline, evalarg->eval_cookie);
1941 	else
1942 	    next = peek_next_line_from_context(evalarg->eval_cctx);
1943 
1944 	if (next != NULL)
1945 	{
1946 	    *getnext = TRUE;
1947 	    return skipwhite(next);
1948 	}
1949     }
1950     return p;
1951 }
1952 
1953 /*
1954  * To be called after eval_next_non_blank() sets "getnext" to TRUE.
1955  */
1956     char_u *
1957 eval_next_line(evalarg_T *evalarg)
1958 {
1959     garray_T	*gap = &evalarg->eval_ga;
1960     char_u	*line;
1961 
1962     if (evalarg->eval_cookie != NULL)
1963 	line = evalarg->eval_getline(0, evalarg->eval_cookie, 0, TRUE);
1964     else
1965 	line = next_line_from_context(evalarg->eval_cctx, TRUE);
1966     ++evalarg->eval_break_count;
1967     if (gap->ga_itemsize > 0 && ga_grow(gap, 1) == OK)
1968     {
1969 	// Going to concatenate the lines after parsing.
1970 	((char_u **)gap->ga_data)[gap->ga_len] = line;
1971 	++gap->ga_len;
1972     }
1973     else if (evalarg->eval_cookie != NULL)
1974     {
1975 	vim_free(evalarg->eval_tofree);
1976 	evalarg->eval_tofree = line;
1977     }
1978     return skipwhite(line);
1979 }
1980 
1981 /*
1982  * Call eval_next_non_blank() and get the next line if needed.
1983  */
1984     char_u *
1985 skipwhite_and_linebreak(char_u *arg, evalarg_T *evalarg)
1986 {
1987     int	    getnext;
1988     char_u  *p = skipwhite(arg);
1989 
1990     if (evalarg == NULL)
1991 	return skipwhite(arg);
1992     eval_next_non_blank(p, evalarg, &getnext);
1993     if (getnext)
1994 	return eval_next_line(evalarg);
1995     return p;
1996 }
1997 
1998 /*
1999  * After using "evalarg" filled from "eap": free the memory.
2000  */
2001     void
2002 clear_evalarg(evalarg_T *evalarg, exarg_T *eap)
2003 {
2004     if (evalarg != NULL)
2005     {
2006 	if (evalarg->eval_tofree != NULL)
2007 	{
2008 	    if (eap != NULL)
2009 	    {
2010 		// We may need to keep the original command line, e.g. for
2011 		// ":let" it has the variable names.  But we may also need the
2012 		// new one, "nextcmd" points into it.  Keep both.
2013 		vim_free(eap->cmdline_tofree);
2014 		eap->cmdline_tofree = *eap->cmdlinep;
2015 		*eap->cmdlinep = evalarg->eval_tofree;
2016 	    }
2017 	    else
2018 		vim_free(evalarg->eval_tofree);
2019 	    evalarg->eval_tofree = NULL;
2020 	}
2021 
2022 	vim_free(evalarg->eval_tofree_lambda);
2023 	evalarg->eval_tofree_lambda = NULL;
2024     }
2025 }
2026 
2027 /*
2028  * The "evaluate" argument: When FALSE, the argument is only parsed but not
2029  * executed.  The function may return OK, but the rettv will be of type
2030  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
2031  */
2032 
2033 /*
2034  * Handle zero level expression.
2035  * This calls eval1() and handles error message and nextcmd.
2036  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
2037  * Note: "rettv.v_lock" is not set.
2038  * "evalarg" can be NULL, EVALARG_EVALUATE or a pointer.
2039  * Return OK or FAIL.
2040  */
2041     int
2042 eval0(
2043     char_u	*arg,
2044     typval_T	*rettv,
2045     exarg_T	*eap,
2046     evalarg_T	*evalarg)
2047 {
2048     int		ret;
2049     char_u	*p;
2050     int		did_emsg_before = did_emsg;
2051     int		called_emsg_before = called_emsg;
2052     int		flags = evalarg == NULL ? 0 : evalarg->eval_flags;
2053 
2054     p = skipwhite(arg);
2055     ret = eval1(&p, rettv, evalarg);
2056     p = skipwhite(p);
2057 
2058     if (ret == FAIL || !ends_excmd2(arg, p))
2059     {
2060 	if (ret != FAIL)
2061 	    clear_tv(rettv);
2062 	/*
2063 	 * Report the invalid expression unless the expression evaluation has
2064 	 * been cancelled due to an aborting error, an interrupt, or an
2065 	 * exception, or we already gave a more specific error.
2066 	 * Also check called_emsg for when using assert_fails().
2067 	 */
2068 	if (!aborting()
2069 		&& did_emsg == did_emsg_before
2070 		&& called_emsg == called_emsg_before
2071 		&& (flags & EVAL_CONSTANT) == 0)
2072 	    semsg(_(e_invexpr2), arg);
2073 	ret = FAIL;
2074     }
2075 
2076     if (eap != NULL)
2077 	eap->nextcmd = check_nextcmd(p);
2078 
2079     return ret;
2080 }
2081 
2082 /*
2083  * Handle top level expression:
2084  *	expr2 ? expr1 : expr1
2085  *
2086  * "arg" must point to the first non-white of the expression.
2087  * "arg" is advanced to just after the recognized expression.
2088  *
2089  * Note: "rettv.v_lock" is not set.
2090  *
2091  * Return OK or FAIL.
2092  */
2093     int
2094 eval1(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2095 {
2096     char_u  *p;
2097     int	    getnext;
2098 
2099     /*
2100      * Get the first variable.
2101      */
2102     if (eval2(arg, rettv, evalarg) == FAIL)
2103 	return FAIL;
2104 
2105     p = eval_next_non_blank(*arg, evalarg, &getnext);
2106     if (*p == '?')
2107     {
2108 	int		result;
2109 	typval_T	var2;
2110 	evalarg_T	*evalarg_used = evalarg;
2111 	evalarg_T	local_evalarg;
2112 	int		orig_flags;
2113 	int		evaluate;
2114 
2115 	if (evalarg == NULL)
2116 	{
2117 	    CLEAR_FIELD(local_evalarg);
2118 	    evalarg_used = &local_evalarg;
2119 	}
2120 	orig_flags = evalarg_used->eval_flags;
2121 	evaluate = evalarg_used->eval_flags & EVAL_EVALUATE;
2122 
2123 	if (getnext)
2124 	    *arg = eval_next_line(evalarg_used);
2125 	else
2126 	{
2127 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2128 	    {
2129 		error_white_both(p, 1);
2130 		clear_tv(rettv);
2131 		return FAIL;
2132 	    }
2133 	    *arg = p;
2134 	}
2135 
2136 	result = FALSE;
2137 	if (evaluate)
2138 	{
2139 	    int		error = FALSE;
2140 
2141 	    if (tv_get_number_chk(rettv, &error) != 0)
2142 		result = TRUE;
2143 	    clear_tv(rettv);
2144 	    if (error)
2145 		return FAIL;
2146 	}
2147 
2148 	/*
2149 	 * Get the second variable.  Recursive!
2150 	 */
2151 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[1]))
2152 	{
2153 	    error_white_both(p, 1);
2154 	    clear_tv(rettv);
2155 	    return FAIL;
2156 	}
2157 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2158 	evalarg_used->eval_flags = result ? orig_flags
2159 						 : orig_flags & ~EVAL_EVALUATE;
2160 	if (eval1(arg, rettv, evalarg_used) == FAIL)
2161 	    return FAIL;
2162 
2163 	/*
2164 	 * Check for the ":".
2165 	 */
2166 	p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2167 	if (*p != ':')
2168 	{
2169 	    emsg(_(e_missing_colon));
2170 	    if (evaluate && result)
2171 		clear_tv(rettv);
2172 	    return FAIL;
2173 	}
2174 	if (getnext)
2175 	    *arg = eval_next_line(evalarg_used);
2176 	else
2177 	{
2178 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2179 	    {
2180 		error_white_both(p, 1);
2181 		clear_tv(rettv);
2182 		return FAIL;
2183 	    }
2184 	    *arg = p;
2185 	}
2186 
2187 	/*
2188 	 * Get the third variable.  Recursive!
2189 	 */
2190 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[1]))
2191 	{
2192 	    error_white_both(p, 1);
2193 	    clear_tv(rettv);
2194 	    return FAIL;
2195 	}
2196 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2197 	evalarg_used->eval_flags = !result ? orig_flags
2198 						 : orig_flags & ~EVAL_EVALUATE;
2199 	if (eval1(arg, &var2, evalarg_used) == FAIL)
2200 	{
2201 	    if (evaluate && result)
2202 		clear_tv(rettv);
2203 	    return FAIL;
2204 	}
2205 	if (evaluate && !result)
2206 	    *rettv = var2;
2207 
2208 	if (evalarg == NULL)
2209 	    clear_evalarg(&local_evalarg, NULL);
2210 	else
2211 	    evalarg->eval_flags = orig_flags;
2212     }
2213 
2214     return OK;
2215 }
2216 
2217 /*
2218  * Handle first level expression:
2219  *	expr2 || expr2 || expr2	    logical OR
2220  *
2221  * "arg" must point to the first non-white of the expression.
2222  * "arg" is advanced to just after the recognized expression.
2223  *
2224  * Return OK or FAIL.
2225  */
2226     static int
2227 eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2228 {
2229     char_u	*p;
2230     int		getnext;
2231 
2232     /*
2233      * Get the first variable.
2234      */
2235     if (eval3(arg, rettv, evalarg) == FAIL)
2236 	return FAIL;
2237 
2238     /*
2239      * Handle the  "||" operator.
2240      */
2241     p = eval_next_non_blank(*arg, evalarg, &getnext);
2242     if (p[0] == '|' && p[1] == '|')
2243     {
2244 	evalarg_T   *evalarg_used = evalarg;
2245 	evalarg_T   local_evalarg;
2246 	int	    evaluate;
2247 	int	    orig_flags;
2248 	long	    result = FALSE;
2249 	typval_T    var2;
2250 	int	    error;
2251 	int	    vim9script = in_vim9script();
2252 
2253 	if (evalarg == NULL)
2254 	{
2255 	    CLEAR_FIELD(local_evalarg);
2256 	    evalarg_used = &local_evalarg;
2257 	}
2258 	orig_flags = evalarg_used->eval_flags;
2259 	evaluate = orig_flags & EVAL_EVALUATE;
2260 	if (evaluate)
2261 	{
2262 	    if (vim9script)
2263 	    {
2264 		result = tv2bool(rettv);
2265 	    }
2266 	    else
2267 	    {
2268 		error = FALSE;
2269 		if (tv_get_number_chk(rettv, &error) != 0)
2270 		    result = TRUE;
2271 		clear_tv(rettv);
2272 		if (error)
2273 		    return FAIL;
2274 	    }
2275 	}
2276 
2277 	/*
2278 	 * Repeat until there is no following "||".
2279 	 */
2280 	while (p[0] == '|' && p[1] == '|')
2281 	{
2282 	    if (getnext)
2283 		*arg = eval_next_line(evalarg_used);
2284 	    else
2285 	    {
2286 		if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2287 		{
2288 		    error_white_both(p, 2);
2289 		    clear_tv(rettv);
2290 		    return FAIL;
2291 		}
2292 		*arg = p;
2293 	    }
2294 
2295 	    /*
2296 	     * Get the second variable.
2297 	     */
2298 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2299 	    {
2300 		error_white_both(p, 2);
2301 		clear_tv(rettv);
2302 		return FAIL;
2303 	    }
2304 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2305 	    evalarg_used->eval_flags = !result ? orig_flags
2306 						 : orig_flags & ~EVAL_EVALUATE;
2307 	    if (eval3(arg, &var2, evalarg_used) == FAIL)
2308 		return FAIL;
2309 
2310 	    /*
2311 	     * Compute the result.
2312 	     */
2313 	    if (evaluate && !result)
2314 	    {
2315 		if (vim9script)
2316 		{
2317 		    clear_tv(rettv);
2318 		    *rettv = var2;
2319 		    result = tv2bool(rettv);
2320 		}
2321 		else
2322 		{
2323 		    if (tv_get_number_chk(&var2, &error) != 0)
2324 			result = TRUE;
2325 		    clear_tv(&var2);
2326 		    if (error)
2327 			return FAIL;
2328 		}
2329 	    }
2330 	    if (evaluate && !vim9script)
2331 	    {
2332 		rettv->v_type = VAR_NUMBER;
2333 		rettv->vval.v_number = result;
2334 	    }
2335 
2336 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2337 	}
2338 
2339 	if (evalarg == NULL)
2340 	    clear_evalarg(&local_evalarg, NULL);
2341 	else
2342 	    evalarg->eval_flags = orig_flags;
2343     }
2344 
2345     return OK;
2346 }
2347 
2348 /*
2349  * Handle second level expression:
2350  *	expr3 && expr3 && expr3	    logical AND
2351  *
2352  * "arg" must point to the first non-white of the expression.
2353  * "arg" is advanced to just after the recognized expression.
2354  *
2355  * Return OK or FAIL.
2356  */
2357     static int
2358 eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2359 {
2360     char_u	*p;
2361     int		getnext;
2362 
2363     /*
2364      * Get the first variable.
2365      */
2366     if (eval4(arg, rettv, evalarg) == FAIL)
2367 	return FAIL;
2368 
2369     /*
2370      * Handle the "&&" operator.
2371      */
2372     p = eval_next_non_blank(*arg, evalarg, &getnext);
2373     if (p[0] == '&' && p[1] == '&')
2374     {
2375 	evalarg_T   *evalarg_used = evalarg;
2376 	evalarg_T   local_evalarg;
2377 	int	    orig_flags;
2378 	int	    evaluate;
2379 	long	    result = TRUE;
2380 	typval_T    var2;
2381 	int	    error;
2382 	int	    vim9script = in_vim9script();
2383 
2384 	if (evalarg == NULL)
2385 	{
2386 	    CLEAR_FIELD(local_evalarg);
2387 	    evalarg_used = &local_evalarg;
2388 	}
2389 	orig_flags = evalarg_used->eval_flags;
2390 	evaluate = orig_flags & EVAL_EVALUATE;
2391 	if (evaluate)
2392 	{
2393 	    if (vim9script)
2394 	    {
2395 		result = tv2bool(rettv);
2396 	    }
2397 	    else
2398 	    {
2399 		error = FALSE;
2400 		if (tv_get_number_chk(rettv, &error) == 0)
2401 		    result = FALSE;
2402 		clear_tv(rettv);
2403 		if (error)
2404 		    return FAIL;
2405 	    }
2406 	}
2407 
2408 	/*
2409 	 * Repeat until there is no following "&&".
2410 	 */
2411 	while (p[0] == '&' && p[1] == '&')
2412 	{
2413 	    if (getnext)
2414 		*arg = eval_next_line(evalarg_used);
2415 	    else
2416 	    {
2417 		if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2418 		{
2419 		    error_white_both(p, 2);
2420 		    clear_tv(rettv);
2421 		    return FAIL;
2422 		}
2423 		*arg = p;
2424 	    }
2425 
2426 	    /*
2427 	     * Get the second variable.
2428 	     */
2429 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2430 	    {
2431 		error_white_both(p, 2);
2432 		clear_tv(rettv);
2433 		return FAIL;
2434 	    }
2435 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2436 	    evalarg_used->eval_flags = result ? orig_flags
2437 						 : orig_flags & ~EVAL_EVALUATE;
2438 	    if (eval4(arg, &var2, evalarg_used) == FAIL)
2439 		return FAIL;
2440 
2441 	    /*
2442 	     * Compute the result.
2443 	     */
2444 	    if (evaluate && result)
2445 	    {
2446 		if (vim9script)
2447 		{
2448 		    clear_tv(rettv);
2449 		    *rettv = var2;
2450 		    result = tv2bool(rettv);
2451 		}
2452 		else
2453 		{
2454 		    if (tv_get_number_chk(&var2, &error) == 0)
2455 			result = FALSE;
2456 		    clear_tv(&var2);
2457 		    if (error)
2458 			return FAIL;
2459 		}
2460 	    }
2461 	    if (evaluate && !vim9script)
2462 	    {
2463 		rettv->v_type = VAR_NUMBER;
2464 		rettv->vval.v_number = result;
2465 	    }
2466 
2467 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2468 	}
2469 
2470 	if (evalarg == NULL)
2471 	    clear_evalarg(&local_evalarg, NULL);
2472 	else
2473 	    evalarg->eval_flags = orig_flags;
2474     }
2475 
2476     return OK;
2477 }
2478 
2479 /*
2480  * Handle third level expression:
2481  *	var1 == var2
2482  *	var1 =~ var2
2483  *	var1 != var2
2484  *	var1 !~ var2
2485  *	var1 > var2
2486  *	var1 >= var2
2487  *	var1 < var2
2488  *	var1 <= var2
2489  *	var1 is var2
2490  *	var1 isnot var2
2491  *
2492  * "arg" must point to the first non-white of the expression.
2493  * "arg" is advanced to just after the recognized expression.
2494  *
2495  * Return OK or FAIL.
2496  */
2497     static int
2498 eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2499 {
2500     char_u	*p;
2501     int		getnext;
2502     exptype_T	type = EXPR_UNKNOWN;
2503     int		len = 2;
2504     int		type_is = FALSE;
2505 
2506     /*
2507      * Get the first variable.
2508      */
2509     if (eval5(arg, rettv, evalarg) == FAIL)
2510 	return FAIL;
2511 
2512     p = eval_next_non_blank(*arg, evalarg, &getnext);
2513     type = get_compare_type(p, &len, &type_is);
2514 
2515     /*
2516      * If there is a comparative operator, use it.
2517      */
2518     if (type != EXPR_UNKNOWN)
2519     {
2520 	typval_T    var2;
2521 	int	    ic;
2522 	int	    vim9script = in_vim9script();
2523 	int	    evaluate = evalarg == NULL
2524 				   ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2525 
2526 	if (getnext)
2527 	    *arg = eval_next_line(evalarg);
2528 	else if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2529 	{
2530 	    error_white_both(p, len);
2531 	    clear_tv(rettv);
2532 	    return FAIL;
2533 	}
2534 
2535 	if (vim9script && type_is && (p[len] == '?' || p[len] == '#'))
2536 	{
2537 	    semsg(_(e_invexpr2), p);
2538 	    clear_tv(rettv);
2539 	    return FAIL;
2540 	}
2541 
2542 	// extra question mark appended: ignore case
2543 	if (p[len] == '?')
2544 	{
2545 	    ic = TRUE;
2546 	    ++len;
2547 	}
2548 	// extra '#' appended: match case
2549 	else if (p[len] == '#')
2550 	{
2551 	    ic = FALSE;
2552 	    ++len;
2553 	}
2554 	// nothing appended: use 'ignorecase' if not in Vim script
2555 	else
2556 	    ic = vim9script ? FALSE : p_ic;
2557 
2558 	/*
2559 	 * Get the second variable.
2560 	 */
2561 	if (evaluate && vim9script && !IS_WHITE_OR_NUL(p[len]))
2562 	{
2563 	    error_white_both(p, 1);
2564 	    clear_tv(rettv);
2565 	    return FAIL;
2566 	}
2567 	*arg = skipwhite_and_linebreak(p + len, evalarg);
2568 	if (eval5(arg, &var2, evalarg) == FAIL)
2569 	{
2570 	    clear_tv(rettv);
2571 	    return FAIL;
2572 	}
2573 	if (evaluate)
2574 	{
2575 	    int ret;
2576 
2577 	    if (vim9script && check_compare_types(type, rettv, &var2) == FAIL)
2578 	    {
2579 		ret = FAIL;
2580 		clear_tv(rettv);
2581 	    }
2582 	    else
2583 		ret = typval_compare(rettv, &var2, type, ic);
2584 	    clear_tv(&var2);
2585 	    return ret;
2586 	}
2587     }
2588 
2589     return OK;
2590 }
2591 
2592     void
2593 eval_addblob(typval_T *tv1, typval_T *tv2)
2594 {
2595     blob_T  *b1 = tv1->vval.v_blob;
2596     blob_T  *b2 = tv2->vval.v_blob;
2597     blob_T  *b = blob_alloc();
2598     int	    i;
2599 
2600     if (b != NULL)
2601     {
2602 	for (i = 0; i < blob_len(b1); i++)
2603 	    ga_append(&b->bv_ga, blob_get(b1, i));
2604 	for (i = 0; i < blob_len(b2); i++)
2605 	    ga_append(&b->bv_ga, blob_get(b2, i));
2606 
2607 	clear_tv(tv1);
2608 	rettv_blob_set(tv1, b);
2609     }
2610 }
2611 
2612     int
2613 eval_addlist(typval_T *tv1, typval_T *tv2)
2614 {
2615     typval_T var3;
2616 
2617     // concatenate Lists
2618     if (list_concat(tv1->vval.v_list, tv2->vval.v_list, &var3) == FAIL)
2619     {
2620 	clear_tv(tv1);
2621 	clear_tv(tv2);
2622 	return FAIL;
2623     }
2624     clear_tv(tv1);
2625     *tv1 = var3;
2626     return OK;
2627 }
2628 
2629 /*
2630  * Handle fourth level expression:
2631  *	+	number addition
2632  *	-	number subtraction
2633  *	.	string concatenation (if script version is 1)
2634  *	..	string concatenation
2635  *
2636  * "arg" must point to the first non-white of the expression.
2637  * "arg" is advanced to just after the recognized expression.
2638  *
2639  * Return OK or FAIL.
2640  */
2641     static int
2642 eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2643 {
2644     /*
2645      * Get the first variable.
2646      */
2647     if (eval6(arg, rettv, evalarg, FALSE) == FAIL)
2648 	return FAIL;
2649 
2650     /*
2651      * Repeat computing, until no '+', '-' or '.' is following.
2652      */
2653     for (;;)
2654     {
2655 	int	    evaluate;
2656 	int	    getnext;
2657 	char_u	    *p;
2658 	int	    op;
2659 	int	    oplen;
2660 	int	    concat;
2661 	typval_T    var2;
2662 
2663 	// "." is only string concatenation when scriptversion is 1
2664 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2665 	op = *p;
2666 	concat = op == '.' && (*(p + 1) == '.' || current_sctx.sc_version < 2);
2667 	if (op != '+' && op != '-' && !concat)
2668 	    break;
2669 
2670 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2671 	oplen = (concat && p[1] == '.') ? 2 : 1;
2672 	if (getnext)
2673 	    *arg = eval_next_line(evalarg);
2674 	else
2675 	{
2676 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(**arg))
2677 	    {
2678 		error_white_both(p, oplen);
2679 		clear_tv(rettv);
2680 		return FAIL;
2681 	    }
2682 	    *arg = p;
2683 	}
2684 	if ((op != '+' || (rettv->v_type != VAR_LIST
2685 						 && rettv->v_type != VAR_BLOB))
2686 #ifdef FEAT_FLOAT
2687 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2688 #endif
2689 		)
2690 	{
2691 	    // For "list + ...", an illegal use of the first operand as
2692 	    // a number cannot be determined before evaluating the 2nd
2693 	    // operand: if this is also a list, all is ok.
2694 	    // For "something . ...", "something - ..." or "non-list + ...",
2695 	    // we know that the first operand needs to be a string or number
2696 	    // without evaluating the 2nd operand.  So check before to avoid
2697 	    // side effects after an error.
2698 	    if (evaluate && tv_get_string_chk(rettv) == NULL)
2699 	    {
2700 		clear_tv(rettv);
2701 		return FAIL;
2702 	    }
2703 	}
2704 
2705 	/*
2706 	 * Get the second variable.
2707 	 */
2708 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[oplen]))
2709 	{
2710 	    error_white_both(p, oplen);
2711 	    clear_tv(rettv);
2712 	    return FAIL;
2713 	}
2714 	*arg = skipwhite_and_linebreak(*arg + oplen, evalarg);
2715 	if (eval6(arg, &var2, evalarg, op == '.') == FAIL)
2716 	{
2717 	    clear_tv(rettv);
2718 	    return FAIL;
2719 	}
2720 
2721 	if (evaluate)
2722 	{
2723 	    /*
2724 	     * Compute the result.
2725 	     */
2726 	    if (op == '.')
2727 	    {
2728 		char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
2729 		char_u	*s1 = tv_get_string_buf(rettv, buf1);
2730 		char_u	*s2 = tv_get_string_buf_chk(&var2, buf2);
2731 
2732 		if (s2 == NULL)		// type error ?
2733 		{
2734 		    clear_tv(rettv);
2735 		    clear_tv(&var2);
2736 		    return FAIL;
2737 		}
2738 		p = concat_str(s1, s2);
2739 		clear_tv(rettv);
2740 		rettv->v_type = VAR_STRING;
2741 		rettv->vval.v_string = p;
2742 	    }
2743 	    else if (op == '+' && rettv->v_type == VAR_BLOB
2744 						   && var2.v_type == VAR_BLOB)
2745 		eval_addblob(rettv, &var2);
2746 	    else if (op == '+' && rettv->v_type == VAR_LIST
2747 						   && var2.v_type == VAR_LIST)
2748 	    {
2749 		if (eval_addlist(rettv, &var2) == FAIL)
2750 		    return FAIL;
2751 	    }
2752 	    else
2753 	    {
2754 		int		error = FALSE;
2755 		varnumber_T	n1, n2;
2756 #ifdef FEAT_FLOAT
2757 		float_T	    f1 = 0, f2 = 0;
2758 
2759 		if (rettv->v_type == VAR_FLOAT)
2760 		{
2761 		    f1 = rettv->vval.v_float;
2762 		    n1 = 0;
2763 		}
2764 		else
2765 #endif
2766 		{
2767 		    n1 = tv_get_number_chk(rettv, &error);
2768 		    if (error)
2769 		    {
2770 			// This can only happen for "list + non-list".  For
2771 			// "non-list + ..." or "something - ...", we returned
2772 			// before evaluating the 2nd operand.
2773 			clear_tv(rettv);
2774 			return FAIL;
2775 		    }
2776 #ifdef FEAT_FLOAT
2777 		    if (var2.v_type == VAR_FLOAT)
2778 			f1 = n1;
2779 #endif
2780 		}
2781 #ifdef FEAT_FLOAT
2782 		if (var2.v_type == VAR_FLOAT)
2783 		{
2784 		    f2 = var2.vval.v_float;
2785 		    n2 = 0;
2786 		}
2787 		else
2788 #endif
2789 		{
2790 		    n2 = tv_get_number_chk(&var2, &error);
2791 		    if (error)
2792 		    {
2793 			clear_tv(rettv);
2794 			clear_tv(&var2);
2795 			return FAIL;
2796 		    }
2797 #ifdef FEAT_FLOAT
2798 		    if (rettv->v_type == VAR_FLOAT)
2799 			f2 = n2;
2800 #endif
2801 		}
2802 		clear_tv(rettv);
2803 
2804 #ifdef FEAT_FLOAT
2805 		// If there is a float on either side the result is a float.
2806 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
2807 		{
2808 		    if (op == '+')
2809 			f1 = f1 + f2;
2810 		    else
2811 			f1 = f1 - f2;
2812 		    rettv->v_type = VAR_FLOAT;
2813 		    rettv->vval.v_float = f1;
2814 		}
2815 		else
2816 #endif
2817 		{
2818 		    if (op == '+')
2819 			n1 = n1 + n2;
2820 		    else
2821 			n1 = n1 - n2;
2822 		    rettv->v_type = VAR_NUMBER;
2823 		    rettv->vval.v_number = n1;
2824 		}
2825 	    }
2826 	    clear_tv(&var2);
2827 	}
2828     }
2829     return OK;
2830 }
2831 
2832 /*
2833  * Handle fifth level expression:
2834  *	*	number multiplication
2835  *	/	number division
2836  *	%	number modulo
2837  *
2838  * "arg" must point to the first non-white of the expression.
2839  * "arg" is advanced to just after the recognized expression.
2840  *
2841  * Return OK or FAIL.
2842  */
2843     static int
2844 eval6(
2845     char_u	**arg,
2846     typval_T	*rettv,
2847     evalarg_T	*evalarg,
2848     int		want_string)  // after "." operator
2849 {
2850 #ifdef FEAT_FLOAT
2851     int	    use_float = FALSE;
2852 #endif
2853 
2854     /*
2855      * Get the first variable.
2856      */
2857     if (eval7(arg, rettv, evalarg, want_string) == FAIL)
2858 	return FAIL;
2859 
2860     /*
2861      * Repeat computing, until no '*', '/' or '%' is following.
2862      */
2863     for (;;)
2864     {
2865 	int	    evaluate;
2866 	int	    getnext;
2867 	typval_T    var2;
2868 	char_u	    *p;
2869 	int	    op;
2870 	varnumber_T n1, n2;
2871 #ifdef FEAT_FLOAT
2872 	float_T	    f1, f2;
2873 #endif
2874 	int	    error;
2875 
2876 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2877 	op = *p;
2878 	if (op != '*' && op != '/' && op != '%')
2879 	    break;
2880 
2881 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2882 	if (getnext)
2883 	    *arg = eval_next_line(evalarg);
2884 	else
2885 	{
2886 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(**arg))
2887 	    {
2888 		error_white_both(p, 1);
2889 		clear_tv(rettv);
2890 		return FAIL;
2891 	    }
2892 	    *arg = p;
2893 	}
2894 
2895 #ifdef FEAT_FLOAT
2896 	f1 = 0;
2897 	f2 = 0;
2898 #endif
2899 	error = FALSE;
2900 	if (evaluate)
2901 	{
2902 #ifdef FEAT_FLOAT
2903 	    if (rettv->v_type == VAR_FLOAT)
2904 	    {
2905 		f1 = rettv->vval.v_float;
2906 		use_float = TRUE;
2907 		n1 = 0;
2908 	    }
2909 	    else
2910 #endif
2911 		n1 = tv_get_number_chk(rettv, &error);
2912 	    clear_tv(rettv);
2913 	    if (error)
2914 		return FAIL;
2915 	}
2916 	else
2917 	    n1 = 0;
2918 
2919 	/*
2920 	 * Get the second variable.
2921 	 */
2922 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[1]))
2923 	{
2924 	    error_white_both(p, 1);
2925 	    clear_tv(rettv);
2926 	    return FAIL;
2927 	}
2928 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
2929 	if (eval7(arg, &var2, evalarg, FALSE) == FAIL)
2930 	    return FAIL;
2931 
2932 	if (evaluate)
2933 	{
2934 #ifdef FEAT_FLOAT
2935 	    if (var2.v_type == VAR_FLOAT)
2936 	    {
2937 		if (!use_float)
2938 		{
2939 		    f1 = n1;
2940 		    use_float = TRUE;
2941 		}
2942 		f2 = var2.vval.v_float;
2943 		n2 = 0;
2944 	    }
2945 	    else
2946 #endif
2947 	    {
2948 		n2 = tv_get_number_chk(&var2, &error);
2949 		clear_tv(&var2);
2950 		if (error)
2951 		    return FAIL;
2952 #ifdef FEAT_FLOAT
2953 		if (use_float)
2954 		    f2 = n2;
2955 #endif
2956 	    }
2957 
2958 	    /*
2959 	     * Compute the result.
2960 	     * When either side is a float the result is a float.
2961 	     */
2962 #ifdef FEAT_FLOAT
2963 	    if (use_float)
2964 	    {
2965 		if (op == '*')
2966 		    f1 = f1 * f2;
2967 		else if (op == '/')
2968 		{
2969 # ifdef VMS
2970 		    // VMS crashes on divide by zero, work around it
2971 		    if (f2 == 0.0)
2972 		    {
2973 			if (f1 == 0)
2974 			    f1 = -1 * __F_FLT_MAX - 1L;   // similar to NaN
2975 			else if (f1 < 0)
2976 			    f1 = -1 * __F_FLT_MAX;
2977 			else
2978 			    f1 = __F_FLT_MAX;
2979 		    }
2980 		    else
2981 			f1 = f1 / f2;
2982 # else
2983 		    // We rely on the floating point library to handle divide
2984 		    // by zero to result in "inf" and not a crash.
2985 		    f1 = f1 / f2;
2986 # endif
2987 		}
2988 		else
2989 		{
2990 		    emsg(_(e_modulus));
2991 		    return FAIL;
2992 		}
2993 		rettv->v_type = VAR_FLOAT;
2994 		rettv->vval.v_float = f1;
2995 	    }
2996 	    else
2997 #endif
2998 	    {
2999 		if (op == '*')
3000 		    n1 = n1 * n2;
3001 		else if (op == '/')
3002 		    n1 = num_divide(n1, n2);
3003 		else
3004 		    n1 = num_modulus(n1, n2);
3005 
3006 		rettv->v_type = VAR_NUMBER;
3007 		rettv->vval.v_number = n1;
3008 	    }
3009 	}
3010     }
3011 
3012     return OK;
3013 }
3014 
3015 /*
3016  * Handle sixth level expression:
3017  *  number		number constant
3018  *  0zFFFFFFFF		Blob constant
3019  *  "string"		string constant
3020  *  'string'		literal string constant
3021  *  &option-name	option value
3022  *  @r			register contents
3023  *  identifier		variable value
3024  *  function()		function call
3025  *  $VAR		environment variable
3026  *  (expression)	nested expression
3027  *  [expr, expr]	List
3028  *  {arg, arg -> expr}	Lambda
3029  *  {key: val, key: val}   Dictionary
3030  *  #{key: val, key: val}  Dictionary with literal keys
3031  *
3032  *  Also handle:
3033  *  ! in front		logical NOT
3034  *  - in front		unary minus
3035  *  + in front		unary plus (ignored)
3036  *  trailing []		subscript in String or List
3037  *  trailing .name	entry in Dictionary
3038  *  trailing ->name()	method call
3039  *
3040  * "arg" must point to the first non-white of the expression.
3041  * "arg" is advanced to just after the recognized expression.
3042  *
3043  * Return OK or FAIL.
3044  */
3045     static int
3046 eval7(
3047     char_u	**arg,
3048     typval_T	*rettv,
3049     evalarg_T	*evalarg,
3050     int		want_string)	// after "." operator
3051 {
3052     int		evaluate = evalarg != NULL
3053 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3054     int		len;
3055     char_u	*s;
3056     char_u	*start_leader, *end_leader;
3057     int		ret = OK;
3058     char_u	*alias;
3059 
3060     /*
3061      * Initialise variable so that clear_tv() can't mistake this for a
3062      * string and free a string that isn't there.
3063      */
3064     rettv->v_type = VAR_UNKNOWN;
3065 
3066     /*
3067      * Skip '!', '-' and '+' characters.  They are handled later.
3068      */
3069     start_leader = *arg;
3070     while (**arg == '!' || **arg == '-' || **arg == '+')
3071 	*arg = skipwhite(*arg + 1);
3072     end_leader = *arg;
3073 
3074     if (**arg == '.' && (!isdigit(*(*arg + 1))
3075 #ifdef FEAT_FLOAT
3076 	    || current_sctx.sc_version < 2
3077 #endif
3078 	    ))
3079     {
3080 	semsg(_(e_invexpr2), *arg);
3081 	++*arg;
3082 	return FAIL;
3083     }
3084 
3085     switch (**arg)
3086     {
3087     /*
3088      * Number constant.
3089      */
3090     case '0':
3091     case '1':
3092     case '2':
3093     case '3':
3094     case '4':
3095     case '5':
3096     case '6':
3097     case '7':
3098     case '8':
3099     case '9':
3100     case '.':	ret = eval_number(arg, rettv, evaluate, want_string);
3101 
3102 		// Apply prefixed "-" and "+" now.  Matters especially when
3103 		// "->" follows.
3104 		if (ret == OK && evaluate && end_leader > start_leader
3105 						  && rettv->v_type != VAR_BLOB)
3106 		    ret = eval7_leader(rettv, TRUE, start_leader, &end_leader);
3107 		break;
3108 
3109     /*
3110      * String constant: "string".
3111      */
3112     case '"':	ret = eval_string(arg, rettv, evaluate);
3113 		break;
3114 
3115     /*
3116      * Literal string constant: 'str''ing'.
3117      */
3118     case '\'':	ret = eval_lit_string(arg, rettv, evaluate);
3119 		break;
3120 
3121     /*
3122      * List: [expr, expr]
3123      */
3124     case '[':	ret = eval_list(arg, rettv, evalarg, TRUE);
3125 		break;
3126 
3127     /*
3128      * Dictionary: #{key: val, key: val}
3129      */
3130     case '#':	if ((*arg)[1] == '{')
3131 		{
3132 		    ++*arg;
3133 		    ret = eval_dict(arg, rettv, evalarg, TRUE);
3134 		}
3135 		else
3136 		    ret = NOTDONE;
3137 		break;
3138 
3139     /*
3140      * Lambda: {arg, arg -> expr}
3141      * Dictionary: {'key': val, 'key': val}
3142      */
3143     case '{':	ret = get_lambda_tv(arg, rettv, evalarg);
3144 		if (ret == NOTDONE)
3145 		    ret = eval_dict(arg, rettv, evalarg, FALSE);
3146 		break;
3147 
3148     /*
3149      * Option value: &name
3150      */
3151     case '&':	ret = eval_option(arg, rettv, evaluate);
3152 		break;
3153 
3154     /*
3155      * Environment variable: $VAR.
3156      */
3157     case '$':	ret = eval_env_var(arg, rettv, evaluate);
3158 		break;
3159 
3160     /*
3161      * Register contents: @r.
3162      */
3163     case '@':	++*arg;
3164 		if (evaluate)
3165 		{
3166 		    rettv->v_type = VAR_STRING;
3167 		    rettv->vval.v_string = get_reg_contents(**arg,
3168 							    GREG_EXPR_SRC);
3169 		}
3170 		if (**arg != NUL)
3171 		    ++*arg;
3172 		break;
3173 
3174     /*
3175      * nested expression: (expression).
3176      */
3177     case '(':	{
3178 		    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3179 		    ret = eval1(arg, rettv, evalarg);	// recursive!
3180 
3181 		    *arg = skipwhite_and_linebreak(*arg, evalarg);
3182 		    if (**arg == ')')
3183 			++*arg;
3184 		    else if (ret == OK)
3185 		    {
3186 			emsg(_(e_missing_close));
3187 			clear_tv(rettv);
3188 			ret = FAIL;
3189 		    }
3190 		}
3191 		break;
3192 
3193     default:	ret = NOTDONE;
3194 		break;
3195     }
3196 
3197     if (ret == NOTDONE)
3198     {
3199 	/*
3200 	 * Must be a variable or function name.
3201 	 * Can also be a curly-braces kind of name: {expr}.
3202 	 */
3203 	s = *arg;
3204 	len = get_name_len(arg, &alias, evaluate, TRUE);
3205 	if (alias != NULL)
3206 	    s = alias;
3207 
3208 	if (len <= 0)
3209 	    ret = FAIL;
3210 	else
3211 	{
3212 	    int	    flags = evalarg == NULL ? 0 : evalarg->eval_flags;
3213 
3214 	    if ((in_vim9script() ? **arg : *skipwhite(*arg)) == '(')
3215 	    {
3216 		// "name(..."  recursive!
3217 		*arg = skipwhite(*arg);
3218 		ret = eval_func(arg, evalarg, s, len, rettv, flags, NULL);
3219 	    }
3220 	    else if (flags & EVAL_CONSTANT)
3221 		ret = FAIL;
3222 	    else if (evaluate)
3223 	    {
3224 		// get the value of "true", "false" or a variable
3225 		if (len == 4 && in_vim9script() && STRNCMP(s, "true", 4) == 0)
3226 		{
3227 		    rettv->v_type = VAR_BOOL;
3228 		    rettv->vval.v_number = VVAL_TRUE;
3229 		    ret = OK;
3230 		}
3231 		else if (len == 5 && in_vim9script()
3232 						&& STRNCMP(s, "false", 4) == 0)
3233 		{
3234 		    rettv->v_type = VAR_BOOL;
3235 		    rettv->vval.v_number = VVAL_FALSE;
3236 		    ret = OK;
3237 		}
3238 		else
3239 		    ret = eval_variable(s, len, rettv, NULL, TRUE, FALSE);
3240 	    }
3241 	    else
3242 	    {
3243 		// skip the name
3244 		check_vars(s, len);
3245 		ret = OK;
3246 	    }
3247 	}
3248 	vim_free(alias);
3249     }
3250 
3251     // Handle following '[', '(' and '.' for expr[expr], expr.name,
3252     // expr(expr), expr->name(expr)
3253     if (ret == OK)
3254 	ret = handle_subscript(arg, rettv, evalarg, TRUE);
3255 
3256     /*
3257      * Apply logical NOT and unary '-', from right to left, ignore '+'.
3258      */
3259     if (ret == OK && evaluate && end_leader > start_leader)
3260 	ret = eval7_leader(rettv, FALSE, start_leader, &end_leader);
3261     return ret;
3262 }
3263 
3264 /*
3265  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
3266  * When "numeric_only" is TRUE only handle "+" and "-".
3267  * Adjusts "end_leaderp" until it is at "start_leader".
3268  */
3269     static int
3270 eval7_leader(
3271 	typval_T    *rettv,
3272 	int	    numeric_only,
3273 	char_u	    *start_leader,
3274 	char_u	    **end_leaderp)
3275 {
3276     char_u	*end_leader = *end_leaderp;
3277     int		ret = OK;
3278     int		error = FALSE;
3279     varnumber_T val = 0;
3280     vartype_T	type = rettv->v_type;
3281 #ifdef FEAT_FLOAT
3282     float_T	    f = 0.0;
3283 
3284     if (rettv->v_type == VAR_FLOAT)
3285 	f = rettv->vval.v_float;
3286     else
3287 #endif
3288 	if (in_vim9script() && end_leader[-1] == '!')
3289 	    val = tv2bool(rettv);
3290 	else
3291 	    val = tv_get_number_chk(rettv, &error);
3292     if (error)
3293     {
3294 	clear_tv(rettv);
3295 	ret = FAIL;
3296     }
3297     else
3298     {
3299 	while (end_leader > start_leader)
3300 	{
3301 	    --end_leader;
3302 	    if (*end_leader == '!')
3303 	    {
3304 		if (numeric_only)
3305 		{
3306 		    ++end_leader;
3307 		    break;
3308 		}
3309 #ifdef FEAT_FLOAT
3310 		if (rettv->v_type == VAR_FLOAT)
3311 		    f = !f;
3312 		else
3313 #endif
3314 		{
3315 		    val = !val;
3316 		    type = VAR_BOOL;
3317 		}
3318 	    }
3319 	    else if (*end_leader == '-')
3320 	    {
3321 #ifdef FEAT_FLOAT
3322 		if (rettv->v_type == VAR_FLOAT)
3323 		    f = -f;
3324 		else
3325 #endif
3326 		{
3327 		    val = -val;
3328 		    type = VAR_NUMBER;
3329 		}
3330 	    }
3331 	}
3332 #ifdef FEAT_FLOAT
3333 	if (rettv->v_type == VAR_FLOAT)
3334 	{
3335 	    clear_tv(rettv);
3336 	    rettv->vval.v_float = f;
3337 	}
3338 	else
3339 #endif
3340 	{
3341 	    clear_tv(rettv);
3342 	    if (in_vim9script())
3343 		rettv->v_type = type;
3344 	    else
3345 		rettv->v_type = VAR_NUMBER;
3346 	    rettv->vval.v_number = val;
3347 	}
3348     }
3349     *end_leaderp = end_leader;
3350     return ret;
3351 }
3352 
3353 /*
3354  * Call the function referred to in "rettv".
3355  */
3356     static int
3357 call_func_rettv(
3358 	char_u	    **arg,
3359 	evalarg_T   *evalarg,
3360 	typval_T    *rettv,
3361 	int	    evaluate,
3362 	dict_T	    *selfdict,
3363 	typval_T    *basetv)
3364 {
3365     partial_T	*pt = NULL;
3366     funcexe_T	funcexe;
3367     typval_T	functv;
3368     char_u	*s;
3369     int		ret;
3370 
3371     // need to copy the funcref so that we can clear rettv
3372     if (evaluate)
3373     {
3374 	functv = *rettv;
3375 	rettv->v_type = VAR_UNKNOWN;
3376 
3377 	// Invoke the function.  Recursive!
3378 	if (functv.v_type == VAR_PARTIAL)
3379 	{
3380 	    pt = functv.vval.v_partial;
3381 	    s = partial_name(pt);
3382 	}
3383 	else
3384 	    s = functv.vval.v_string;
3385     }
3386     else
3387 	s = (char_u *)"";
3388 
3389     CLEAR_FIELD(funcexe);
3390     funcexe.firstline = curwin->w_cursor.lnum;
3391     funcexe.lastline = curwin->w_cursor.lnum;
3392     funcexe.evaluate = evaluate;
3393     funcexe.partial = pt;
3394     funcexe.selfdict = selfdict;
3395     funcexe.basetv = basetv;
3396     ret = get_func_tv(s, -1, rettv, arg, evalarg, &funcexe);
3397 
3398     // Clear the funcref afterwards, so that deleting it while
3399     // evaluating the arguments is possible (see test55).
3400     if (evaluate)
3401 	clear_tv(&functv);
3402 
3403     return ret;
3404 }
3405 
3406 /*
3407  * Evaluate "->method()".
3408  * "*arg" points to the '-'.
3409  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3410  */
3411     static int
3412 eval_lambda(
3413     char_u	**arg,
3414     typval_T	*rettv,
3415     evalarg_T	*evalarg,
3416     int		verbose)	// give error messages
3417 {
3418     int		evaluate = evalarg != NULL
3419 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3420     typval_T	base = *rettv;
3421     int		ret;
3422 
3423     // Skip over the ->.
3424     *arg += 2;
3425     rettv->v_type = VAR_UNKNOWN;
3426 
3427     ret = get_lambda_tv(arg, rettv, evalarg);
3428     if (ret != OK)
3429 	return FAIL;
3430     else if (**arg != '(')
3431     {
3432 	if (verbose)
3433 	{
3434 	    if (*skipwhite(*arg) == '(')
3435 		emsg(_(e_nowhitespace));
3436 	    else
3437 		semsg(_(e_missing_paren), "lambda");
3438 	}
3439 	clear_tv(rettv);
3440 	ret = FAIL;
3441     }
3442     else
3443 	ret = call_func_rettv(arg, evalarg, rettv, evaluate, NULL, &base);
3444 
3445     // Clear the funcref afterwards, so that deleting it while
3446     // evaluating the arguments is possible (see test55).
3447     if (evaluate)
3448 	clear_tv(&base);
3449 
3450     return ret;
3451 }
3452 
3453 /*
3454  * Evaluate "->method()".
3455  * "*arg" points to the '-'.
3456  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3457  */
3458     static int
3459 eval_method(
3460     char_u	**arg,
3461     typval_T	*rettv,
3462     evalarg_T	*evalarg,
3463     int		verbose)	// give error messages
3464 {
3465     char_u	*name;
3466     long	len;
3467     char_u	*alias;
3468     typval_T	base = *rettv;
3469     int		ret;
3470     int		evaluate = evalarg != NULL
3471 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3472 
3473     // Skip over the ->.
3474     *arg += 2;
3475     rettv->v_type = VAR_UNKNOWN;
3476 
3477     name = *arg;
3478     len = get_name_len(arg, &alias, evaluate, TRUE);
3479     if (alias != NULL)
3480 	name = alias;
3481 
3482     if (len <= 0)
3483     {
3484 	if (verbose)
3485 	    emsg(_("E260: Missing name after ->"));
3486 	ret = FAIL;
3487     }
3488     else
3489     {
3490 	*arg = skipwhite(*arg);
3491 	if (**arg != '(')
3492 	{
3493 	    if (verbose)
3494 		semsg(_(e_missing_paren), name);
3495 	    ret = FAIL;
3496 	}
3497 	else if (VIM_ISWHITE((*arg)[-1]))
3498 	{
3499 	    if (verbose)
3500 		emsg(_(e_nowhitespace));
3501 	    ret = FAIL;
3502 	}
3503 	else
3504 	    ret = eval_func(arg, evalarg, name, len, rettv,
3505 					  evaluate ? EVAL_EVALUATE : 0, &base);
3506     }
3507 
3508     // Clear the funcref afterwards, so that deleting it while
3509     // evaluating the arguments is possible (see test55).
3510     if (evaluate)
3511 	clear_tv(&base);
3512 
3513     return ret;
3514 }
3515 
3516 /*
3517  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
3518  * "*arg" points to the '[' or '.'.
3519  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
3520  */
3521     static int
3522 eval_index(
3523     char_u	**arg,
3524     typval_T	*rettv,
3525     evalarg_T	*evalarg,
3526     int		verbose)	// give error messages
3527 {
3528     int		evaluate = evalarg != NULL
3529 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3530     int		empty1 = FALSE, empty2 = FALSE;
3531     typval_T	var1, var2;
3532     long	i;
3533     long	n1, n2 = 0;
3534     long	len = -1;
3535     int		range = FALSE;
3536     char_u	*s;
3537     char_u	*key = NULL;
3538 
3539     switch (rettv->v_type)
3540     {
3541 	case VAR_FUNC:
3542 	case VAR_PARTIAL:
3543 	    if (verbose)
3544 		emsg(_("E695: Cannot index a Funcref"));
3545 	    return FAIL;
3546 	case VAR_FLOAT:
3547 #ifdef FEAT_FLOAT
3548 	    if (verbose)
3549 		emsg(_(e_float_as_string));
3550 	    return FAIL;
3551 #endif
3552 	case VAR_BOOL:
3553 	case VAR_SPECIAL:
3554 	case VAR_JOB:
3555 	case VAR_CHANNEL:
3556 	    if (verbose)
3557 		emsg(_("E909: Cannot index a special variable"));
3558 	    return FAIL;
3559 	case VAR_UNKNOWN:
3560 	case VAR_ANY:
3561 	case VAR_VOID:
3562 	    if (evaluate)
3563 		return FAIL;
3564 	    // FALLTHROUGH
3565 
3566 	case VAR_STRING:
3567 	case VAR_NUMBER:
3568 	case VAR_LIST:
3569 	case VAR_DICT:
3570 	case VAR_BLOB:
3571 	    break;
3572     }
3573 
3574     init_tv(&var1);
3575     init_tv(&var2);
3576     if (**arg == '.')
3577     {
3578 	/*
3579 	 * dict.name
3580 	 */
3581 	key = *arg + 1;
3582 	for (len = 0; eval_isdictc(key[len]); ++len)
3583 	    ;
3584 	if (len == 0)
3585 	    return FAIL;
3586 	*arg = skipwhite(key + len);
3587     }
3588     else
3589     {
3590 	/*
3591 	 * something[idx]
3592 	 *
3593 	 * Get the (first) variable from inside the [].
3594 	 */
3595 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3596 	if (**arg == ':')
3597 	    empty1 = TRUE;
3598 	else if (eval1(arg, &var1, evalarg) == FAIL)	// recursive!
3599 	    return FAIL;
3600 	else if (evaluate && tv_get_string_chk(&var1) == NULL)
3601 	{
3602 	    // not a number or string
3603 	    clear_tv(&var1);
3604 	    return FAIL;
3605 	}
3606 
3607 	/*
3608 	 * Get the second variable from inside the [:].
3609 	 */
3610 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3611 	if (**arg == ':')
3612 	{
3613 	    range = TRUE;
3614 	    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3615 	    if (**arg == ']')
3616 		empty2 = TRUE;
3617 	    else if (eval1(arg, &var2, evalarg) == FAIL)	// recursive!
3618 	    {
3619 		if (!empty1)
3620 		    clear_tv(&var1);
3621 		return FAIL;
3622 	    }
3623 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
3624 	    {
3625 		// not a number or string
3626 		if (!empty1)
3627 		    clear_tv(&var1);
3628 		clear_tv(&var2);
3629 		return FAIL;
3630 	    }
3631 	}
3632 
3633 	// Check for the ']'.
3634 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3635 	if (**arg != ']')
3636 	{
3637 	    if (verbose)
3638 		emsg(_(e_missbrac));
3639 	    clear_tv(&var1);
3640 	    if (range)
3641 		clear_tv(&var2);
3642 	    return FAIL;
3643 	}
3644 	*arg = skipwhite(*arg + 1);	// skip the ']'
3645     }
3646 
3647     if (evaluate)
3648     {
3649 	n1 = 0;
3650 	if (!empty1 && rettv->v_type != VAR_DICT)
3651 	{
3652 	    n1 = tv_get_number(&var1);
3653 	    clear_tv(&var1);
3654 	}
3655 	if (range)
3656 	{
3657 	    if (empty2)
3658 		n2 = -1;
3659 	    else
3660 	    {
3661 		n2 = tv_get_number(&var2);
3662 		clear_tv(&var2);
3663 	    }
3664 	}
3665 
3666 	switch (rettv->v_type)
3667 	{
3668 	    case VAR_UNKNOWN:
3669 	    case VAR_ANY:
3670 	    case VAR_VOID:
3671 	    case VAR_FUNC:
3672 	    case VAR_PARTIAL:
3673 	    case VAR_FLOAT:
3674 	    case VAR_BOOL:
3675 	    case VAR_SPECIAL:
3676 	    case VAR_JOB:
3677 	    case VAR_CHANNEL:
3678 		break; // not evaluating, skipping over subscript
3679 
3680 	    case VAR_NUMBER:
3681 	    case VAR_STRING:
3682 		s = tv_get_string(rettv);
3683 		len = (long)STRLEN(s);
3684 		if (range)
3685 		{
3686 		    // The resulting variable is a substring.  If the indexes
3687 		    // are out of range the result is empty.
3688 		    if (n1 < 0)
3689 		    {
3690 			n1 = len + n1;
3691 			if (n1 < 0)
3692 			    n1 = 0;
3693 		    }
3694 		    if (n2 < 0)
3695 			n2 = len + n2;
3696 		    else if (n2 >= len)
3697 			n2 = len;
3698 		    if (n1 >= len || n2 < 0 || n1 > n2)
3699 			s = NULL;
3700 		    else
3701 			s = vim_strnsave(s + n1, n2 - n1 + 1);
3702 		}
3703 		else
3704 		{
3705 		    // The resulting variable is a string of a single
3706 		    // character.  If the index is too big or negative the
3707 		    // result is empty.
3708 		    if (n1 >= len || n1 < 0)
3709 			s = NULL;
3710 		    else
3711 			s = vim_strnsave(s + n1, 1);
3712 		}
3713 		clear_tv(rettv);
3714 		rettv->v_type = VAR_STRING;
3715 		rettv->vval.v_string = s;
3716 		break;
3717 
3718 	    case VAR_BLOB:
3719 		len = blob_len(rettv->vval.v_blob);
3720 		if (range)
3721 		{
3722 		    // The resulting variable is a sub-blob.  If the indexes
3723 		    // are out of range the result is empty.
3724 		    if (n1 < 0)
3725 		    {
3726 			n1 = len + n1;
3727 			if (n1 < 0)
3728 			    n1 = 0;
3729 		    }
3730 		    if (n2 < 0)
3731 			n2 = len + n2;
3732 		    else if (n2 >= len)
3733 			n2 = len - 1;
3734 		    if (n1 >= len || n2 < 0 || n1 > n2)
3735 		    {
3736 			clear_tv(rettv);
3737 			rettv->v_type = VAR_BLOB;
3738 			rettv->vval.v_blob = NULL;
3739 		    }
3740 		    else
3741 		    {
3742 			blob_T  *blob = blob_alloc();
3743 
3744 			if (blob != NULL)
3745 			{
3746 			    if (ga_grow(&blob->bv_ga, n2 - n1 + 1) == FAIL)
3747 			    {
3748 				blob_free(blob);
3749 				return FAIL;
3750 			    }
3751 			    blob->bv_ga.ga_len = n2 - n1 + 1;
3752 			    for (i = n1; i <= n2; i++)
3753 				blob_set(blob, i - n1,
3754 					      blob_get(rettv->vval.v_blob, i));
3755 
3756 			    clear_tv(rettv);
3757 			    rettv_blob_set(rettv, blob);
3758 			}
3759 		    }
3760 		}
3761 		else
3762 		{
3763 		    // The resulting variable is a byte value.
3764 		    // If the index is too big or negative that is an error.
3765 		    if (n1 < 0)
3766 			n1 = len + n1;
3767 		    if (n1 < len && n1 >= 0)
3768 		    {
3769 			int v = blob_get(rettv->vval.v_blob, n1);
3770 
3771 			clear_tv(rettv);
3772 			rettv->v_type = VAR_NUMBER;
3773 			rettv->vval.v_number = v;
3774 		    }
3775 		    else
3776 			semsg(_(e_blobidx), n1);
3777 		}
3778 		break;
3779 
3780 	    case VAR_LIST:
3781 		len = list_len(rettv->vval.v_list);
3782 		if (n1 < 0)
3783 		    n1 = len + n1;
3784 		if (!empty1 && (n1 < 0 || n1 >= len))
3785 		{
3786 		    // For a range we allow invalid values and return an empty
3787 		    // list.  A list index out of range is an error.
3788 		    if (!range)
3789 		    {
3790 			if (verbose)
3791 			    semsg(_(e_listidx), n1);
3792 			return FAIL;
3793 		    }
3794 		    n1 = len;
3795 		}
3796 		if (range)
3797 		{
3798 		    list_T	*l;
3799 
3800 		    if (n2 < 0)
3801 			n2 = len + n2;
3802 		    else if (n2 >= len)
3803 			n2 = len - 1;
3804 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
3805 			n2 = -1;
3806 		    l = list_slice(rettv->vval.v_list, n1, n2);
3807 		    if (l == NULL)
3808 			return FAIL;
3809 		    clear_tv(rettv);
3810 		    rettv_list_set(rettv, l);
3811 		}
3812 		else
3813 		{
3814 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
3815 		    clear_tv(rettv);
3816 		    *rettv = var1;
3817 		}
3818 		break;
3819 
3820 	    case VAR_DICT:
3821 		if (range)
3822 		{
3823 		    if (verbose)
3824 			emsg(_(e_dictrange));
3825 		    if (len == -1)
3826 			clear_tv(&var1);
3827 		    return FAIL;
3828 		}
3829 		{
3830 		    dictitem_T	*item;
3831 
3832 		    if (len == -1)
3833 		    {
3834 			key = tv_get_string_chk(&var1);
3835 			if (key == NULL)
3836 			{
3837 			    clear_tv(&var1);
3838 			    return FAIL;
3839 			}
3840 		    }
3841 
3842 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
3843 
3844 		    if (item == NULL && verbose)
3845 			semsg(_(e_dictkey), key);
3846 		    if (len == -1)
3847 			clear_tv(&var1);
3848 		    if (item == NULL)
3849 			return FAIL;
3850 
3851 		    copy_tv(&item->di_tv, &var1);
3852 		    clear_tv(rettv);
3853 		    *rettv = var1;
3854 		}
3855 		break;
3856 	}
3857     }
3858 
3859     return OK;
3860 }
3861 
3862 /*
3863  * Return the function name of partial "pt".
3864  */
3865     char_u *
3866 partial_name(partial_T *pt)
3867 {
3868     if (pt->pt_name != NULL)
3869 	return pt->pt_name;
3870     if (pt->pt_func != NULL)
3871 	return pt->pt_func->uf_name;
3872     return (char_u *)"";
3873 }
3874 
3875     static void
3876 partial_free(partial_T *pt)
3877 {
3878     int i;
3879 
3880     for (i = 0; i < pt->pt_argc; ++i)
3881 	clear_tv(&pt->pt_argv[i]);
3882     vim_free(pt->pt_argv);
3883     dict_unref(pt->pt_dict);
3884     if (pt->pt_name != NULL)
3885     {
3886 	func_unref(pt->pt_name);
3887 	vim_free(pt->pt_name);
3888     }
3889     else
3890 	func_ptr_unref(pt->pt_func);
3891 
3892     if (pt->pt_funcstack != NULL)
3893     {
3894 	// Decrease the reference count for the context of a closure.  If down
3895 	// to zero free it and clear the variables on the stack.
3896 	if (--pt->pt_funcstack->fs_refcount == 0)
3897 	{
3898 	    garray_T	*gap = &pt->pt_funcstack->fs_ga;
3899 	    typval_T	*stack = gap->ga_data;
3900 
3901 	    for (i = 0; i < gap->ga_len; ++i)
3902 		clear_tv(stack + i);
3903 	    ga_clear(gap);
3904 	    vim_free(pt->pt_funcstack);
3905 	}
3906 	pt->pt_funcstack = NULL;
3907     }
3908 
3909     vim_free(pt);
3910 }
3911 
3912 /*
3913  * Unreference a closure: decrement the reference count and free it when it
3914  * becomes zero.
3915  */
3916     void
3917 partial_unref(partial_T *pt)
3918 {
3919     if (pt != NULL && --pt->pt_refcount <= 0)
3920 	partial_free(pt);
3921 }
3922 
3923 /*
3924  * Return the next (unique) copy ID.
3925  * Used for serializing nested structures.
3926  */
3927     int
3928 get_copyID(void)
3929 {
3930     current_copyID += COPYID_INC;
3931     return current_copyID;
3932 }
3933 
3934 /*
3935  * Garbage collection for lists and dictionaries.
3936  *
3937  * We use reference counts to be able to free most items right away when they
3938  * are no longer used.  But for composite items it's possible that it becomes
3939  * unused while the reference count is > 0: When there is a recursive
3940  * reference.  Example:
3941  *	:let l = [1, 2, 3]
3942  *	:let d = {9: l}
3943  *	:let l[1] = d
3944  *
3945  * Since this is quite unusual we handle this with garbage collection: every
3946  * once in a while find out which lists and dicts are not referenced from any
3947  * variable.
3948  *
3949  * Here is a good reference text about garbage collection (refers to Python
3950  * but it applies to all reference-counting mechanisms):
3951  *	http://python.ca/nas/python/gc/
3952  */
3953 
3954 /*
3955  * Do garbage collection for lists and dicts.
3956  * When "testing" is TRUE this is called from test_garbagecollect_now().
3957  * Return TRUE if some memory was freed.
3958  */
3959     int
3960 garbage_collect(int testing)
3961 {
3962     int		copyID;
3963     int		abort = FALSE;
3964     buf_T	*buf;
3965     win_T	*wp;
3966     int		did_free = FALSE;
3967     tabpage_T	*tp;
3968 
3969     if (!testing)
3970     {
3971 	// Only do this once.
3972 	want_garbage_collect = FALSE;
3973 	may_garbage_collect = FALSE;
3974 	garbage_collect_at_exit = FALSE;
3975     }
3976 
3977     // The execution stack can grow big, limit the size.
3978     if (exestack.ga_maxlen - exestack.ga_len > 500)
3979     {
3980 	size_t	new_len;
3981 	char_u	*pp;
3982 	int	n;
3983 
3984 	// Keep 150% of the current size, with a minimum of the growth size.
3985 	n = exestack.ga_len / 2;
3986 	if (n < exestack.ga_growsize)
3987 	    n = exestack.ga_growsize;
3988 
3989 	// Don't make it bigger though.
3990 	if (exestack.ga_len + n < exestack.ga_maxlen)
3991 	{
3992 	    new_len = exestack.ga_itemsize * (exestack.ga_len + n);
3993 	    pp = vim_realloc(exestack.ga_data, new_len);
3994 	    if (pp == NULL)
3995 		return FAIL;
3996 	    exestack.ga_maxlen = exestack.ga_len + n;
3997 	    exestack.ga_data = pp;
3998 	}
3999     }
4000 
4001     // We advance by two because we add one for items referenced through
4002     // previous_funccal.
4003     copyID = get_copyID();
4004 
4005     /*
4006      * 1. Go through all accessible variables and mark all lists and dicts
4007      *    with copyID.
4008      */
4009 
4010     // Don't free variables in the previous_funccal list unless they are only
4011     // referenced through previous_funccal.  This must be first, because if
4012     // the item is referenced elsewhere the funccal must not be freed.
4013     abort = abort || set_ref_in_previous_funccal(copyID);
4014 
4015     // script-local variables
4016     abort = abort || garbage_collect_scriptvars(copyID);
4017 
4018     // buffer-local variables
4019     FOR_ALL_BUFFERS(buf)
4020 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
4021 								  NULL, NULL);
4022 
4023     // window-local variables
4024     FOR_ALL_TAB_WINDOWS(tp, wp)
4025 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4026 								  NULL, NULL);
4027     if (aucmd_win != NULL)
4028 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
4029 								  NULL, NULL);
4030 #ifdef FEAT_PROP_POPUP
4031     FOR_ALL_POPUPWINS(wp)
4032 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4033 								  NULL, NULL);
4034     FOR_ALL_TABPAGES(tp)
4035 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
4036 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4037 								  NULL, NULL);
4038 #endif
4039 
4040     // tabpage-local variables
4041     FOR_ALL_TABPAGES(tp)
4042 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
4043 								  NULL, NULL);
4044     // global variables
4045     abort = abort || garbage_collect_globvars(copyID);
4046 
4047     // function-local variables
4048     abort = abort || set_ref_in_call_stack(copyID);
4049 
4050     // named functions (matters for closures)
4051     abort = abort || set_ref_in_functions(copyID);
4052 
4053     // function call arguments, if v:testing is set.
4054     abort = abort || set_ref_in_func_args(copyID);
4055 
4056     // v: vars
4057     abort = abort || garbage_collect_vimvars(copyID);
4058 
4059     // callbacks in buffers
4060     abort = abort || set_ref_in_buffers(copyID);
4061 
4062 #ifdef FEAT_LUA
4063     abort = abort || set_ref_in_lua(copyID);
4064 #endif
4065 
4066 #ifdef FEAT_PYTHON
4067     abort = abort || set_ref_in_python(copyID);
4068 #endif
4069 
4070 #ifdef FEAT_PYTHON3
4071     abort = abort || set_ref_in_python3(copyID);
4072 #endif
4073 
4074 #ifdef FEAT_JOB_CHANNEL
4075     abort = abort || set_ref_in_channel(copyID);
4076     abort = abort || set_ref_in_job(copyID);
4077 #endif
4078 #ifdef FEAT_NETBEANS_INTG
4079     abort = abort || set_ref_in_nb_channel(copyID);
4080 #endif
4081 
4082 #ifdef FEAT_TIMERS
4083     abort = abort || set_ref_in_timer(copyID);
4084 #endif
4085 
4086 #ifdef FEAT_QUICKFIX
4087     abort = abort || set_ref_in_quickfix(copyID);
4088 #endif
4089 
4090 #ifdef FEAT_TERMINAL
4091     abort = abort || set_ref_in_term(copyID);
4092 #endif
4093 
4094 #ifdef FEAT_PROP_POPUP
4095     abort = abort || set_ref_in_popups(copyID);
4096 #endif
4097 
4098     if (!abort)
4099     {
4100 	/*
4101 	 * 2. Free lists and dictionaries that are not referenced.
4102 	 */
4103 	did_free = free_unref_items(copyID);
4104 
4105 	/*
4106 	 * 3. Check if any funccal can be freed now.
4107 	 *    This may call us back recursively.
4108 	 */
4109 	free_unref_funccal(copyID, testing);
4110     }
4111     else if (p_verbose > 0)
4112     {
4113 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
4114     }
4115 
4116     return did_free;
4117 }
4118 
4119 /*
4120  * Free lists, dictionaries, channels and jobs that are no longer referenced.
4121  */
4122     static int
4123 free_unref_items(int copyID)
4124 {
4125     int		did_free = FALSE;
4126 
4127     // Let all "free" functions know that we are here.  This means no
4128     // dictionaries, lists, channels or jobs are to be freed, because we will
4129     // do that here.
4130     in_free_unref_items = TRUE;
4131 
4132     /*
4133      * PASS 1: free the contents of the items.  We don't free the items
4134      * themselves yet, so that it is possible to decrement refcount counters
4135      */
4136 
4137     // Go through the list of dicts and free items without the copyID.
4138     did_free |= dict_free_nonref(copyID);
4139 
4140     // Go through the list of lists and free items without the copyID.
4141     did_free |= list_free_nonref(copyID);
4142 
4143 #ifdef FEAT_JOB_CHANNEL
4144     // Go through the list of jobs and free items without the copyID. This
4145     // must happen before doing channels, because jobs refer to channels, but
4146     // the reference from the channel to the job isn't tracked.
4147     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4148 
4149     // Go through the list of channels and free items without the copyID.
4150     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4151 #endif
4152 
4153     /*
4154      * PASS 2: free the items themselves.
4155      */
4156     dict_free_items(copyID);
4157     list_free_items(copyID);
4158 
4159 #ifdef FEAT_JOB_CHANNEL
4160     // Go through the list of jobs and free items without the copyID. This
4161     // must happen before doing channels, because jobs refer to channels, but
4162     // the reference from the channel to the job isn't tracked.
4163     free_unused_jobs(copyID, COPYID_MASK);
4164 
4165     // Go through the list of channels and free items without the copyID.
4166     free_unused_channels(copyID, COPYID_MASK);
4167 #endif
4168 
4169     in_free_unref_items = FALSE;
4170 
4171     return did_free;
4172 }
4173 
4174 /*
4175  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4176  * "list_stack" is used to add lists to be marked.  Can be NULL.
4177  *
4178  * Returns TRUE if setting references failed somehow.
4179  */
4180     int
4181 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4182 {
4183     int		todo;
4184     int		abort = FALSE;
4185     hashitem_T	*hi;
4186     hashtab_T	*cur_ht;
4187     ht_stack_T	*ht_stack = NULL;
4188     ht_stack_T	*tempitem;
4189 
4190     cur_ht = ht;
4191     for (;;)
4192     {
4193 	if (!abort)
4194 	{
4195 	    // Mark each item in the hashtab.  If the item contains a hashtab
4196 	    // it is added to ht_stack, if it contains a list it is added to
4197 	    // list_stack.
4198 	    todo = (int)cur_ht->ht_used;
4199 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4200 		if (!HASHITEM_EMPTY(hi))
4201 		{
4202 		    --todo;
4203 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4204 						       &ht_stack, list_stack);
4205 		}
4206 	}
4207 
4208 	if (ht_stack == NULL)
4209 	    break;
4210 
4211 	// take an item from the stack
4212 	cur_ht = ht_stack->ht;
4213 	tempitem = ht_stack;
4214 	ht_stack = ht_stack->prev;
4215 	free(tempitem);
4216     }
4217 
4218     return abort;
4219 }
4220 
4221 /*
4222  * Mark a dict and its items with "copyID".
4223  * Returns TRUE if setting references failed somehow.
4224  */
4225     int
4226 set_ref_in_dict(dict_T *d, int copyID)
4227 {
4228     if (d != NULL && d->dv_copyID != copyID)
4229     {
4230 	d->dv_copyID = copyID;
4231 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4232     }
4233     return FALSE;
4234 }
4235 
4236 /*
4237  * Mark a list and its items with "copyID".
4238  * Returns TRUE if setting references failed somehow.
4239  */
4240     int
4241 set_ref_in_list(list_T *ll, int copyID)
4242 {
4243     if (ll != NULL && ll->lv_copyID != copyID)
4244     {
4245 	ll->lv_copyID = copyID;
4246 	return set_ref_in_list_items(ll, copyID, NULL);
4247     }
4248     return FALSE;
4249 }
4250 
4251 /*
4252  * Mark all lists and dicts referenced through list "l" with "copyID".
4253  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4254  *
4255  * Returns TRUE if setting references failed somehow.
4256  */
4257     int
4258 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4259 {
4260     listitem_T	 *li;
4261     int		 abort = FALSE;
4262     list_T	 *cur_l;
4263     list_stack_T *list_stack = NULL;
4264     list_stack_T *tempitem;
4265 
4266     cur_l = l;
4267     for (;;)
4268     {
4269 	if (!abort && cur_l->lv_first != &range_list_item)
4270 	    // Mark each item in the list.  If the item contains a hashtab
4271 	    // it is added to ht_stack, if it contains a list it is added to
4272 	    // list_stack.
4273 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4274 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4275 						       ht_stack, &list_stack);
4276 	if (list_stack == NULL)
4277 	    break;
4278 
4279 	// take an item from the stack
4280 	cur_l = list_stack->list;
4281 	tempitem = list_stack;
4282 	list_stack = list_stack->prev;
4283 	free(tempitem);
4284     }
4285 
4286     return abort;
4287 }
4288 
4289 /*
4290  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4291  * "list_stack" is used to add lists to be marked.  Can be NULL.
4292  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4293  *
4294  * Returns TRUE if setting references failed somehow.
4295  */
4296     int
4297 set_ref_in_item(
4298     typval_T	    *tv,
4299     int		    copyID,
4300     ht_stack_T	    **ht_stack,
4301     list_stack_T    **list_stack)
4302 {
4303     int		abort = FALSE;
4304 
4305     if (tv->v_type == VAR_DICT)
4306     {
4307 	dict_T	*dd = tv->vval.v_dict;
4308 
4309 	if (dd != NULL && dd->dv_copyID != copyID)
4310 	{
4311 	    // Didn't see this dict yet.
4312 	    dd->dv_copyID = copyID;
4313 	    if (ht_stack == NULL)
4314 	    {
4315 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4316 	    }
4317 	    else
4318 	    {
4319 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
4320 		if (newitem == NULL)
4321 		    abort = TRUE;
4322 		else
4323 		{
4324 		    newitem->ht = &dd->dv_hashtab;
4325 		    newitem->prev = *ht_stack;
4326 		    *ht_stack = newitem;
4327 		}
4328 	    }
4329 	}
4330     }
4331     else if (tv->v_type == VAR_LIST)
4332     {
4333 	list_T	*ll = tv->vval.v_list;
4334 
4335 	if (ll != NULL && ll->lv_copyID != copyID)
4336 	{
4337 	    // Didn't see this list yet.
4338 	    ll->lv_copyID = copyID;
4339 	    if (list_stack == NULL)
4340 	    {
4341 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4342 	    }
4343 	    else
4344 	    {
4345 		list_stack_T *newitem = (list_stack_T*)malloc(
4346 							sizeof(list_stack_T));
4347 		if (newitem == NULL)
4348 		    abort = TRUE;
4349 		else
4350 		{
4351 		    newitem->list = ll;
4352 		    newitem->prev = *list_stack;
4353 		    *list_stack = newitem;
4354 		}
4355 	    }
4356 	}
4357     }
4358     else if (tv->v_type == VAR_FUNC)
4359     {
4360 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4361     }
4362     else if (tv->v_type == VAR_PARTIAL)
4363     {
4364 	partial_T	*pt = tv->vval.v_partial;
4365 	int		i;
4366 
4367 	if (pt != NULL && pt->pt_copyID != copyID)
4368 	{
4369 	    // Didn't see this partial yet.
4370 	    pt->pt_copyID = copyID;
4371 
4372 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4373 
4374 	    if (pt->pt_dict != NULL)
4375 	    {
4376 		typval_T dtv;
4377 
4378 		dtv.v_type = VAR_DICT;
4379 		dtv.vval.v_dict = pt->pt_dict;
4380 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4381 	    }
4382 
4383 	    for (i = 0; i < pt->pt_argc; ++i)
4384 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4385 							ht_stack, list_stack);
4386 	    if (pt->pt_funcstack != NULL)
4387 	    {
4388 		typval_T    *stack = pt->pt_funcstack->fs_ga.ga_data;
4389 
4390 		for (i = 0; i < pt->pt_funcstack->fs_ga.ga_len; ++i)
4391 		    abort = abort || set_ref_in_item(stack + i, copyID,
4392 							 ht_stack, list_stack);
4393 	    }
4394 
4395 	}
4396     }
4397 #ifdef FEAT_JOB_CHANNEL
4398     else if (tv->v_type == VAR_JOB)
4399     {
4400 	job_T	    *job = tv->vval.v_job;
4401 	typval_T    dtv;
4402 
4403 	if (job != NULL && job->jv_copyID != copyID)
4404 	{
4405 	    job->jv_copyID = copyID;
4406 	    if (job->jv_channel != NULL)
4407 	    {
4408 		dtv.v_type = VAR_CHANNEL;
4409 		dtv.vval.v_channel = job->jv_channel;
4410 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4411 	    }
4412 	    if (job->jv_exit_cb.cb_partial != NULL)
4413 	    {
4414 		dtv.v_type = VAR_PARTIAL;
4415 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4416 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4417 	    }
4418 	}
4419     }
4420     else if (tv->v_type == VAR_CHANNEL)
4421     {
4422 	channel_T   *ch =tv->vval.v_channel;
4423 	ch_part_T   part;
4424 	typval_T    dtv;
4425 	jsonq_T	    *jq;
4426 	cbq_T	    *cq;
4427 
4428 	if (ch != NULL && ch->ch_copyID != copyID)
4429 	{
4430 	    ch->ch_copyID = copyID;
4431 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4432 	    {
4433 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4434 							     jq = jq->jq_next)
4435 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4436 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4437 							     cq = cq->cq_next)
4438 		    if (cq->cq_callback.cb_partial != NULL)
4439 		    {
4440 			dtv.v_type = VAR_PARTIAL;
4441 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4442 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4443 		    }
4444 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4445 		{
4446 		    dtv.v_type = VAR_PARTIAL;
4447 		    dtv.vval.v_partial =
4448 				      ch->ch_part[part].ch_callback.cb_partial;
4449 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4450 		}
4451 	    }
4452 	    if (ch->ch_callback.cb_partial != NULL)
4453 	    {
4454 		dtv.v_type = VAR_PARTIAL;
4455 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4456 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4457 	    }
4458 	    if (ch->ch_close_cb.cb_partial != NULL)
4459 	    {
4460 		dtv.v_type = VAR_PARTIAL;
4461 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4462 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4463 	    }
4464 	}
4465     }
4466 #endif
4467     return abort;
4468 }
4469 
4470 /*
4471  * Return a string with the string representation of a variable.
4472  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4473  * "numbuf" is used for a number.
4474  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4475  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4476  * stings as "string()", otherwise does not put quotes around strings, as
4477  * ":echo" displays values.
4478  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4479  * are replaced with "...".
4480  * May return NULL.
4481  */
4482     char_u *
4483 echo_string_core(
4484     typval_T	*tv,
4485     char_u	**tofree,
4486     char_u	*numbuf,
4487     int		copyID,
4488     int		echo_style,
4489     int		restore_copyID,
4490     int		composite_val)
4491 {
4492     static int	recurse = 0;
4493     char_u	*r = NULL;
4494 
4495     if (recurse >= DICT_MAXNEST)
4496     {
4497 	if (!did_echo_string_emsg)
4498 	{
4499 	    // Only give this message once for a recursive call to avoid
4500 	    // flooding the user with errors.  And stop iterating over lists
4501 	    // and dicts.
4502 	    did_echo_string_emsg = TRUE;
4503 	    emsg(_("E724: variable nested too deep for displaying"));
4504 	}
4505 	*tofree = NULL;
4506 	return (char_u *)"{E724}";
4507     }
4508     ++recurse;
4509 
4510     switch (tv->v_type)
4511     {
4512 	case VAR_STRING:
4513 	    if (echo_style && !composite_val)
4514 	    {
4515 		*tofree = NULL;
4516 		r = tv->vval.v_string;
4517 		if (r == NULL)
4518 		    r = (char_u *)"";
4519 	    }
4520 	    else
4521 	    {
4522 		*tofree = string_quote(tv->vval.v_string, FALSE);
4523 		r = *tofree;
4524 	    }
4525 	    break;
4526 
4527 	case VAR_FUNC:
4528 	    if (echo_style)
4529 	    {
4530 		*tofree = NULL;
4531 		r = tv->vval.v_string;
4532 	    }
4533 	    else
4534 	    {
4535 		*tofree = string_quote(tv->vval.v_string, TRUE);
4536 		r = *tofree;
4537 	    }
4538 	    break;
4539 
4540 	case VAR_PARTIAL:
4541 	    {
4542 		partial_T   *pt = tv->vval.v_partial;
4543 		char_u	    *fname = string_quote(pt == NULL ? NULL
4544 						    : partial_name(pt), FALSE);
4545 		garray_T    ga;
4546 		int	    i;
4547 		char_u	    *tf;
4548 
4549 		ga_init2(&ga, 1, 100);
4550 		ga_concat(&ga, (char_u *)"function(");
4551 		if (fname != NULL)
4552 		{
4553 		    ga_concat(&ga, fname);
4554 		    vim_free(fname);
4555 		}
4556 		if (pt != NULL && pt->pt_argc > 0)
4557 		{
4558 		    ga_concat(&ga, (char_u *)", [");
4559 		    for (i = 0; i < pt->pt_argc; ++i)
4560 		    {
4561 			if (i > 0)
4562 			    ga_concat(&ga, (char_u *)", ");
4563 			ga_concat(&ga,
4564 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
4565 			vim_free(tf);
4566 		    }
4567 		    ga_concat(&ga, (char_u *)"]");
4568 		}
4569 		if (pt != NULL && pt->pt_dict != NULL)
4570 		{
4571 		    typval_T dtv;
4572 
4573 		    ga_concat(&ga, (char_u *)", ");
4574 		    dtv.v_type = VAR_DICT;
4575 		    dtv.vval.v_dict = pt->pt_dict;
4576 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
4577 		    vim_free(tf);
4578 		}
4579 		ga_concat(&ga, (char_u *)")");
4580 
4581 		*tofree = ga.ga_data;
4582 		r = *tofree;
4583 		break;
4584 	    }
4585 
4586 	case VAR_BLOB:
4587 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
4588 	    break;
4589 
4590 	case VAR_LIST:
4591 	    if (tv->vval.v_list == NULL)
4592 	    {
4593 		// NULL list is equivalent to empty list.
4594 		*tofree = NULL;
4595 		r = (char_u *)"[]";
4596 	    }
4597 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
4598 		    && tv->vval.v_list->lv_len > 0)
4599 	    {
4600 		*tofree = NULL;
4601 		r = (char_u *)"[...]";
4602 	    }
4603 	    else
4604 	    {
4605 		int old_copyID = tv->vval.v_list->lv_copyID;
4606 
4607 		tv->vval.v_list->lv_copyID = copyID;
4608 		*tofree = list2string(tv, copyID, restore_copyID);
4609 		if (restore_copyID)
4610 		    tv->vval.v_list->lv_copyID = old_copyID;
4611 		r = *tofree;
4612 	    }
4613 	    break;
4614 
4615 	case VAR_DICT:
4616 	    if (tv->vval.v_dict == NULL)
4617 	    {
4618 		// NULL dict is equivalent to empty dict.
4619 		*tofree = NULL;
4620 		r = (char_u *)"{}";
4621 	    }
4622 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
4623 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
4624 	    {
4625 		*tofree = NULL;
4626 		r = (char_u *)"{...}";
4627 	    }
4628 	    else
4629 	    {
4630 		int old_copyID = tv->vval.v_dict->dv_copyID;
4631 
4632 		tv->vval.v_dict->dv_copyID = copyID;
4633 		*tofree = dict2string(tv, copyID, restore_copyID);
4634 		if (restore_copyID)
4635 		    tv->vval.v_dict->dv_copyID = old_copyID;
4636 		r = *tofree;
4637 	    }
4638 	    break;
4639 
4640 	case VAR_NUMBER:
4641 	case VAR_UNKNOWN:
4642 	case VAR_ANY:
4643 	case VAR_VOID:
4644 	    *tofree = NULL;
4645 	    r = tv_get_string_buf(tv, numbuf);
4646 	    break;
4647 
4648 	case VAR_JOB:
4649 	case VAR_CHANNEL:
4650 	    *tofree = NULL;
4651 	    r = tv_get_string_buf(tv, numbuf);
4652 	    if (composite_val)
4653 	    {
4654 		*tofree = string_quote(r, FALSE);
4655 		r = *tofree;
4656 	    }
4657 	    break;
4658 
4659 	case VAR_FLOAT:
4660 #ifdef FEAT_FLOAT
4661 	    *tofree = NULL;
4662 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
4663 	    r = numbuf;
4664 	    break;
4665 #endif
4666 
4667 	case VAR_BOOL:
4668 	case VAR_SPECIAL:
4669 	    *tofree = NULL;
4670 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
4671 	    break;
4672     }
4673 
4674     if (--recurse == 0)
4675 	did_echo_string_emsg = FALSE;
4676     return r;
4677 }
4678 
4679 /*
4680  * Return a string with the string representation of a variable.
4681  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4682  * "numbuf" is used for a number.
4683  * Does not put quotes around strings, as ":echo" displays values.
4684  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4685  * May return NULL.
4686  */
4687     char_u *
4688 echo_string(
4689     typval_T	*tv,
4690     char_u	**tofree,
4691     char_u	*numbuf,
4692     int		copyID)
4693 {
4694     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
4695 }
4696 
4697 /*
4698  * Return string "str" in ' quotes, doubling ' characters.
4699  * If "str" is NULL an empty string is assumed.
4700  * If "function" is TRUE make it function('string').
4701  */
4702     char_u *
4703 string_quote(char_u *str, int function)
4704 {
4705     unsigned	len;
4706     char_u	*p, *r, *s;
4707 
4708     len = (function ? 13 : 3);
4709     if (str != NULL)
4710     {
4711 	len += (unsigned)STRLEN(str);
4712 	for (p = str; *p != NUL; MB_PTR_ADV(p))
4713 	    if (*p == '\'')
4714 		++len;
4715     }
4716     s = r = alloc(len);
4717     if (r != NULL)
4718     {
4719 	if (function)
4720 	{
4721 	    STRCPY(r, "function('");
4722 	    r += 10;
4723 	}
4724 	else
4725 	    *r++ = '\'';
4726 	if (str != NULL)
4727 	    for (p = str; *p != NUL; )
4728 	    {
4729 		if (*p == '\'')
4730 		    *r++ = '\'';
4731 		MB_COPY_CHAR(p, r);
4732 	    }
4733 	*r++ = '\'';
4734 	if (function)
4735 	    *r++ = ')';
4736 	*r++ = NUL;
4737     }
4738     return s;
4739 }
4740 
4741 #if defined(FEAT_FLOAT) || defined(PROTO)
4742 /*
4743  * Convert the string "text" to a floating point number.
4744  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
4745  * this always uses a decimal point.
4746  * Returns the length of the text that was consumed.
4747  */
4748     int
4749 string2float(
4750     char_u	*text,
4751     float_T	*value)	    // result stored here
4752 {
4753     char	*s = (char *)text;
4754     float_T	f;
4755 
4756     // MS-Windows does not deal with "inf" and "nan" properly.
4757     if (STRNICMP(text, "inf", 3) == 0)
4758     {
4759 	*value = INFINITY;
4760 	return 3;
4761     }
4762     if (STRNICMP(text, "-inf", 3) == 0)
4763     {
4764 	*value = -INFINITY;
4765 	return 4;
4766     }
4767     if (STRNICMP(text, "nan", 3) == 0)
4768     {
4769 	*value = NAN;
4770 	return 3;
4771     }
4772     f = strtod(s, &s);
4773     *value = f;
4774     return (int)((char_u *)s - text);
4775 }
4776 #endif
4777 
4778 /*
4779  * Translate a String variable into a position.
4780  * Returns NULL when there is an error.
4781  */
4782     pos_T *
4783 var2fpos(
4784     typval_T	*varp,
4785     int		dollar_lnum,	// TRUE when $ is last line
4786     int		*fnum)		// set to fnum for '0, 'A, etc.
4787 {
4788     char_u		*name;
4789     static pos_T	pos;
4790     pos_T		*pp;
4791 
4792     // Argument can be [lnum, col, coladd].
4793     if (varp->v_type == VAR_LIST)
4794     {
4795 	list_T		*l;
4796 	int		len;
4797 	int		error = FALSE;
4798 	listitem_T	*li;
4799 
4800 	l = varp->vval.v_list;
4801 	if (l == NULL)
4802 	    return NULL;
4803 
4804 	// Get the line number
4805 	pos.lnum = list_find_nr(l, 0L, &error);
4806 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
4807 	    return NULL;	// invalid line number
4808 
4809 	// Get the column number
4810 	pos.col = list_find_nr(l, 1L, &error);
4811 	if (error)
4812 	    return NULL;
4813 	len = (long)STRLEN(ml_get(pos.lnum));
4814 
4815 	// We accept "$" for the column number: last column.
4816 	li = list_find(l, 1L);
4817 	if (li != NULL && li->li_tv.v_type == VAR_STRING
4818 		&& li->li_tv.vval.v_string != NULL
4819 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
4820 	    pos.col = len + 1;
4821 
4822 	// Accept a position up to the NUL after the line.
4823 	if (pos.col == 0 || (int)pos.col > len + 1)
4824 	    return NULL;	// invalid column number
4825 	--pos.col;
4826 
4827 	// Get the virtual offset.  Defaults to zero.
4828 	pos.coladd = list_find_nr(l, 2L, &error);
4829 	if (error)
4830 	    pos.coladd = 0;
4831 
4832 	return &pos;
4833     }
4834 
4835     name = tv_get_string_chk(varp);
4836     if (name == NULL)
4837 	return NULL;
4838     if (name[0] == '.')				// cursor
4839 	return &curwin->w_cursor;
4840     if (name[0] == 'v' && name[1] == NUL)	// Visual start
4841     {
4842 	if (VIsual_active)
4843 	    return &VIsual;
4844 	return &curwin->w_cursor;
4845     }
4846     if (name[0] == '\'')			// mark
4847     {
4848 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
4849 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
4850 	    return NULL;
4851 	return pp;
4852     }
4853 
4854     pos.coladd = 0;
4855 
4856     if (name[0] == 'w' && dollar_lnum)
4857     {
4858 	pos.col = 0;
4859 	if (name[1] == '0')		// "w0": first visible line
4860 	{
4861 	    update_topline();
4862 	    // In silent Ex mode topline is zero, but that's not a valid line
4863 	    // number; use one instead.
4864 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
4865 	    return &pos;
4866 	}
4867 	else if (name[1] == '$')	// "w$": last visible line
4868 	{
4869 	    validate_botline();
4870 	    // In silent Ex mode botline is zero, return zero then.
4871 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
4872 	    return &pos;
4873 	}
4874     }
4875     else if (name[0] == '$')		// last column or line
4876     {
4877 	if (dollar_lnum)
4878 	{
4879 	    pos.lnum = curbuf->b_ml.ml_line_count;
4880 	    pos.col = 0;
4881 	}
4882 	else
4883 	{
4884 	    pos.lnum = curwin->w_cursor.lnum;
4885 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
4886 	}
4887 	return &pos;
4888     }
4889     return NULL;
4890 }
4891 
4892 /*
4893  * Convert list in "arg" into a position and optional file number.
4894  * When "fnump" is NULL there is no file number, only 3 items.
4895  * Note that the column is passed on as-is, the caller may want to decrement
4896  * it to use 1 for the first column.
4897  * Return FAIL when conversion is not possible, doesn't check the position for
4898  * validity.
4899  */
4900     int
4901 list2fpos(
4902     typval_T	*arg,
4903     pos_T	*posp,
4904     int		*fnump,
4905     colnr_T	*curswantp)
4906 {
4907     list_T	*l = arg->vval.v_list;
4908     long	i = 0;
4909     long	n;
4910 
4911     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
4912     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
4913     if (arg->v_type != VAR_LIST
4914 	    || l == NULL
4915 	    || l->lv_len < (fnump == NULL ? 2 : 3)
4916 	    || l->lv_len > (fnump == NULL ? 4 : 5))
4917 	return FAIL;
4918 
4919     if (fnump != NULL)
4920     {
4921 	n = list_find_nr(l, i++, NULL);	// fnum
4922 	if (n < 0)
4923 	    return FAIL;
4924 	if (n == 0)
4925 	    n = curbuf->b_fnum;		// current buffer
4926 	*fnump = n;
4927     }
4928 
4929     n = list_find_nr(l, i++, NULL);	// lnum
4930     if (n < 0)
4931 	return FAIL;
4932     posp->lnum = n;
4933 
4934     n = list_find_nr(l, i++, NULL);	// col
4935     if (n < 0)
4936 	return FAIL;
4937     posp->col = n;
4938 
4939     n = list_find_nr(l, i, NULL);	// off
4940     if (n < 0)
4941 	posp->coladd = 0;
4942     else
4943 	posp->coladd = n;
4944 
4945     if (curswantp != NULL)
4946 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
4947 
4948     return OK;
4949 }
4950 
4951 /*
4952  * Get the length of an environment variable name.
4953  * Advance "arg" to the first character after the name.
4954  * Return 0 for error.
4955  */
4956     int
4957 get_env_len(char_u **arg)
4958 {
4959     char_u	*p;
4960     int		len;
4961 
4962     for (p = *arg; vim_isIDc(*p); ++p)
4963 	;
4964     if (p == *arg)	    // no name found
4965 	return 0;
4966 
4967     len = (int)(p - *arg);
4968     *arg = p;
4969     return len;
4970 }
4971 
4972 /*
4973  * Get the length of the name of a function or internal variable.
4974  * "arg" is advanced to after the name.
4975  * Return 0 if something is wrong.
4976  */
4977     int
4978 get_id_len(char_u **arg)
4979 {
4980     char_u	*p;
4981     int		len;
4982 
4983     // Find the end of the name.
4984     for (p = *arg; eval_isnamec(*p); ++p)
4985     {
4986 	if (*p == ':')
4987 	{
4988 	    // "s:" is start of "s:var", but "n:" is not and can be used in
4989 	    // slice "[n:]".  Also "xx:" is not a namespace.
4990 	    len = (int)(p - *arg);
4991 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
4992 		    || len > 1)
4993 		break;
4994 	}
4995     }
4996     if (p == *arg)	    // no name found
4997 	return 0;
4998 
4999     len = (int)(p - *arg);
5000     *arg = p;
5001 
5002     return len;
5003 }
5004 
5005 /*
5006  * Get the length of the name of a variable or function.
5007  * Only the name is recognized, does not handle ".key" or "[idx]".
5008  * "arg" is advanced to the first non-white character after the name.
5009  * Return -1 if curly braces expansion failed.
5010  * Return 0 if something else is wrong.
5011  * If the name contains 'magic' {}'s, expand them and return the
5012  * expanded name in an allocated string via 'alias' - caller must free.
5013  */
5014     int
5015 get_name_len(
5016     char_u	**arg,
5017     char_u	**alias,
5018     int		evaluate,
5019     int		verbose)
5020 {
5021     int		len;
5022     char_u	*p;
5023     char_u	*expr_start;
5024     char_u	*expr_end;
5025 
5026     *alias = NULL;  // default to no alias
5027 
5028     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
5029 						  && (*arg)[2] == (int)KE_SNR)
5030     {
5031 	// hard coded <SNR>, already translated
5032 	*arg += 3;
5033 	return get_id_len(arg) + 3;
5034     }
5035     len = eval_fname_script(*arg);
5036     if (len > 0)
5037     {
5038 	// literal "<SID>", "s:" or "<SNR>"
5039 	*arg += len;
5040     }
5041 
5042     /*
5043      * Find the end of the name; check for {} construction.
5044      */
5045     p = find_name_end(*arg, &expr_start, &expr_end,
5046 					       len > 0 ? 0 : FNE_CHECK_START);
5047     if (expr_start != NULL)
5048     {
5049 	char_u	*temp_string;
5050 
5051 	if (!evaluate)
5052 	{
5053 	    len += (int)(p - *arg);
5054 	    *arg = skipwhite(p);
5055 	    return len;
5056 	}
5057 
5058 	/*
5059 	 * Include any <SID> etc in the expanded string:
5060 	 * Thus the -len here.
5061 	 */
5062 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
5063 	if (temp_string == NULL)
5064 	    return -1;
5065 	*alias = temp_string;
5066 	*arg = skipwhite(p);
5067 	return (int)STRLEN(temp_string);
5068     }
5069 
5070     len += get_id_len(arg);
5071     // Only give an error when there is something, otherwise it will be
5072     // reported at a higher level.
5073     if (len == 0 && verbose && **arg != NUL)
5074 	semsg(_(e_invexpr2), *arg);
5075 
5076     return len;
5077 }
5078 
5079 /*
5080  * Find the end of a variable or function name, taking care of magic braces.
5081  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
5082  * start and end of the first magic braces item.
5083  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
5084  * Return a pointer to just after the name.  Equal to "arg" if there is no
5085  * valid name.
5086  */
5087     char_u *
5088 find_name_end(
5089     char_u	*arg,
5090     char_u	**expr_start,
5091     char_u	**expr_end,
5092     int		flags)
5093 {
5094     int		mb_nest = 0;
5095     int		br_nest = 0;
5096     char_u	*p;
5097     int		len;
5098     int		vim9script = in_vim9script();
5099 
5100     if (expr_start != NULL)
5101     {
5102 	*expr_start = NULL;
5103 	*expr_end = NULL;
5104     }
5105 
5106     // Quick check for valid starting character.
5107     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg)
5108 						&& (*arg != '{' || vim9script))
5109 	return arg;
5110 
5111     for (p = arg; *p != NUL
5112 		    && (eval_isnamec(*p)
5113 			|| (*p == '{' && !vim9script)
5114 			|| ((flags & FNE_INCL_BR) && (*p == '['
5115 					 || (*p == '.' && eval_isdictc(p[1]))))
5116 			|| mb_nest != 0
5117 			|| br_nest != 0); MB_PTR_ADV(p))
5118     {
5119 	if (*p == '\'')
5120 	{
5121 	    // skip over 'string' to avoid counting [ and ] inside it.
5122 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5123 		;
5124 	    if (*p == NUL)
5125 		break;
5126 	}
5127 	else if (*p == '"')
5128 	{
5129 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
5130 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5131 		if (*p == '\\' && p[1] != NUL)
5132 		    ++p;
5133 	    if (*p == NUL)
5134 		break;
5135 	}
5136 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5137 	{
5138 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5139 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
5140 	    len = (int)(p - arg);
5141 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5142 		    || (len > 1 && p[-1] != '}'))
5143 		break;
5144 	}
5145 
5146 	if (mb_nest == 0)
5147 	{
5148 	    if (*p == '[')
5149 		++br_nest;
5150 	    else if (*p == ']')
5151 		--br_nest;
5152 	}
5153 
5154 	if (br_nest == 0 && !vim9script)
5155 	{
5156 	    if (*p == '{')
5157 	    {
5158 		mb_nest++;
5159 		if (expr_start != NULL && *expr_start == NULL)
5160 		    *expr_start = p;
5161 	    }
5162 	    else if (*p == '}')
5163 	    {
5164 		mb_nest--;
5165 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5166 		    *expr_end = p;
5167 	    }
5168 	}
5169     }
5170 
5171     return p;
5172 }
5173 
5174 /*
5175  * Expands out the 'magic' {}'s in a variable/function name.
5176  * Note that this can call itself recursively, to deal with
5177  * constructs like foo{bar}{baz}{bam}
5178  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5179  *			"in_start"      ^
5180  *			"expr_start"	   ^
5181  *			"expr_end"		 ^
5182  *			"in_end"			    ^
5183  *
5184  * Returns a new allocated string, which the caller must free.
5185  * Returns NULL for failure.
5186  */
5187     static char_u *
5188 make_expanded_name(
5189     char_u	*in_start,
5190     char_u	*expr_start,
5191     char_u	*expr_end,
5192     char_u	*in_end)
5193 {
5194     char_u	c1;
5195     char_u	*retval = NULL;
5196     char_u	*temp_result;
5197 
5198     if (expr_end == NULL || in_end == NULL)
5199 	return NULL;
5200     *expr_start	= NUL;
5201     *expr_end = NUL;
5202     c1 = *in_end;
5203     *in_end = NUL;
5204 
5205     temp_result = eval_to_string(expr_start + 1, FALSE);
5206     if (temp_result != NULL)
5207     {
5208 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5209 						   + (in_end - expr_end) + 1);
5210 	if (retval != NULL)
5211 	{
5212 	    STRCPY(retval, in_start);
5213 	    STRCAT(retval, temp_result);
5214 	    STRCAT(retval, expr_end + 1);
5215 	}
5216     }
5217     vim_free(temp_result);
5218 
5219     *in_end = c1;		// put char back for error messages
5220     *expr_start = '{';
5221     *expr_end = '}';
5222 
5223     if (retval != NULL)
5224     {
5225 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5226 	if (expr_start != NULL)
5227 	{
5228 	    // Further expansion!
5229 	    temp_result = make_expanded_name(retval, expr_start,
5230 						       expr_end, temp_result);
5231 	    vim_free(retval);
5232 	    retval = temp_result;
5233 	}
5234     }
5235 
5236     return retval;
5237 }
5238 
5239 /*
5240  * Return TRUE if character "c" can be used in a variable or function name.
5241  * Does not include '{' or '}' for magic braces.
5242  */
5243     int
5244 eval_isnamec(int c)
5245 {
5246     return ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR;
5247 }
5248 
5249 /*
5250  * Return TRUE if character "c" can be used as the first character in a
5251  * variable or function name (excluding '{' and '}').
5252  */
5253     int
5254 eval_isnamec1(int c)
5255 {
5256     return ASCII_ISALPHA(c) || c == '_';
5257 }
5258 
5259 /*
5260  * Return TRUE if character "c" can be used as the first character of a
5261  * dictionary key.
5262  */
5263     int
5264 eval_isdictc(int c)
5265 {
5266     return ASCII_ISALNUM(c) || c == '_';
5267 }
5268 
5269 /*
5270  * Handle:
5271  * - expr[expr], expr[expr:expr] subscript
5272  * - ".name" lookup
5273  * - function call with Funcref variable: func(expr)
5274  * - method call: var->method()
5275  *
5276  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5277  */
5278     int
5279 handle_subscript(
5280     char_u	**arg,
5281     typval_T	*rettv,
5282     evalarg_T	*evalarg,
5283     int		verbose)	// give error messages
5284 {
5285     int		evaluate = evalarg != NULL
5286 				      && (evalarg->eval_flags & EVAL_EVALUATE);
5287     int		ret = OK;
5288     dict_T	*selfdict = NULL;
5289     int		check_white = TRUE;
5290     int		getnext;
5291     char_u	*p;
5292 
5293     while (ret == OK)
5294     {
5295 	// When at the end of the line and ".name" or "->{" or "->X" follows in
5296 	// the next line then consume the line break.
5297 	p = eval_next_non_blank(*arg, evalarg, &getnext);
5298 	if (getnext
5299 	    && ((rettv->v_type == VAR_DICT && *p == '.' && eval_isdictc(p[1]))
5300 		|| (p[0] == '-' && p[1] == '>'
5301 				     && (p[2] == '{' || ASCII_ISALPHA(p[2])))))
5302 	{
5303 	    *arg = eval_next_line(evalarg);
5304 	    check_white = FALSE;
5305 	}
5306 
5307 	if ((**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5308 			    || rettv->v_type == VAR_PARTIAL))
5309 		    && (!check_white || !VIM_ISWHITE(*(*arg - 1))))
5310 	{
5311 	    ret = call_func_rettv(arg, evalarg, rettv, evaluate,
5312 							       selfdict, NULL);
5313 
5314 	    // Stop the expression evaluation when immediately aborting on
5315 	    // error, or when an interrupt occurred or an exception was thrown
5316 	    // but not caught.
5317 	    if (aborting())
5318 	    {
5319 		if (ret == OK)
5320 		    clear_tv(rettv);
5321 		ret = FAIL;
5322 	    }
5323 	    dict_unref(selfdict);
5324 	    selfdict = NULL;
5325 	}
5326 	else if (p[0] == '-' && p[1] == '>')
5327 	{
5328 	    *arg = p;
5329 	    if (ret == OK)
5330 	    {
5331 		if ((*arg)[2] == '{')
5332 		    // expr->{lambda}()
5333 		    ret = eval_lambda(arg, rettv, evalarg, verbose);
5334 		else
5335 		    // expr->name()
5336 		    ret = eval_method(arg, rettv, evalarg, verbose);
5337 	    }
5338 	}
5339 	// "." is ".name" lookup when we found a dict or when evaluating and
5340 	// scriptversion is at least 2, where string concatenation is "..".
5341 	else if (**arg == '['
5342 		|| (**arg == '.' && (rettv->v_type == VAR_DICT
5343 			|| (!evaluate
5344 			    && (*arg)[1] != '.'
5345 			    && current_sctx.sc_version >= 2))))
5346 	{
5347 	    dict_unref(selfdict);
5348 	    if (rettv->v_type == VAR_DICT)
5349 	    {
5350 		selfdict = rettv->vval.v_dict;
5351 		if (selfdict != NULL)
5352 		    ++selfdict->dv_refcount;
5353 	    }
5354 	    else
5355 		selfdict = NULL;
5356 	    if (eval_index(arg, rettv, evalarg, verbose) == FAIL)
5357 	    {
5358 		clear_tv(rettv);
5359 		ret = FAIL;
5360 	    }
5361 	}
5362 	else
5363 	    break;
5364     }
5365 
5366     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5367     // Don't do this when "Func" is already a partial that was bound
5368     // explicitly (pt_auto is FALSE).
5369     if (selfdict != NULL
5370 	    && (rettv->v_type == VAR_FUNC
5371 		|| (rettv->v_type == VAR_PARTIAL
5372 		    && (rettv->vval.v_partial->pt_auto
5373 			|| rettv->vval.v_partial->pt_dict == NULL))))
5374 	selfdict = make_partial(selfdict, rettv);
5375 
5376     dict_unref(selfdict);
5377     return ret;
5378 }
5379 
5380 /*
5381  * Make a copy of an item.
5382  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5383  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5384  * reference to an already copied list/dict can be used.
5385  * Returns FAIL or OK.
5386  */
5387     int
5388 item_copy(
5389     typval_T	*from,
5390     typval_T	*to,
5391     int		deep,
5392     int		copyID)
5393 {
5394     static int	recurse = 0;
5395     int		ret = OK;
5396 
5397     if (recurse >= DICT_MAXNEST)
5398     {
5399 	emsg(_("E698: variable nested too deep for making a copy"));
5400 	return FAIL;
5401     }
5402     ++recurse;
5403 
5404     switch (from->v_type)
5405     {
5406 	case VAR_NUMBER:
5407 	case VAR_FLOAT:
5408 	case VAR_STRING:
5409 	case VAR_FUNC:
5410 	case VAR_PARTIAL:
5411 	case VAR_BOOL:
5412 	case VAR_SPECIAL:
5413 	case VAR_JOB:
5414 	case VAR_CHANNEL:
5415 	    copy_tv(from, to);
5416 	    break;
5417 	case VAR_LIST:
5418 	    to->v_type = VAR_LIST;
5419 	    to->v_lock = 0;
5420 	    if (from->vval.v_list == NULL)
5421 		to->vval.v_list = NULL;
5422 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
5423 	    {
5424 		// use the copy made earlier
5425 		to->vval.v_list = from->vval.v_list->lv_copylist;
5426 		++to->vval.v_list->lv_refcount;
5427 	    }
5428 	    else
5429 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
5430 	    if (to->vval.v_list == NULL)
5431 		ret = FAIL;
5432 	    break;
5433 	case VAR_BLOB:
5434 	    ret = blob_copy(from->vval.v_blob, to);
5435 	    break;
5436 	case VAR_DICT:
5437 	    to->v_type = VAR_DICT;
5438 	    to->v_lock = 0;
5439 	    if (from->vval.v_dict == NULL)
5440 		to->vval.v_dict = NULL;
5441 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
5442 	    {
5443 		// use the copy made earlier
5444 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
5445 		++to->vval.v_dict->dv_refcount;
5446 	    }
5447 	    else
5448 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
5449 	    if (to->vval.v_dict == NULL)
5450 		ret = FAIL;
5451 	    break;
5452 	case VAR_UNKNOWN:
5453 	case VAR_ANY:
5454 	case VAR_VOID:
5455 	    internal_error_no_abort("item_copy(UNKNOWN)");
5456 	    ret = FAIL;
5457     }
5458     --recurse;
5459     return ret;
5460 }
5461 
5462     void
5463 echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr)
5464 {
5465     char_u	*tofree;
5466     char_u	numbuf[NUMBUFLEN];
5467     char_u	*p = echo_string(rettv, &tofree, numbuf, get_copyID());
5468 
5469     if (*atstart)
5470     {
5471 	*atstart = FALSE;
5472 	// Call msg_start() after eval1(), evaluating the expression
5473 	// may cause a message to appear.
5474 	if (with_space)
5475 	{
5476 	    // Mark the saved text as finishing the line, so that what
5477 	    // follows is displayed on a new line when scrolling back
5478 	    // at the more prompt.
5479 	    msg_sb_eol();
5480 	    msg_start();
5481 	}
5482     }
5483     else if (with_space)
5484 	msg_puts_attr(" ", echo_attr);
5485 
5486     if (p != NULL)
5487 	for ( ; *p != NUL && !got_int; ++p)
5488 	{
5489 	    if (*p == '\n' || *p == '\r' || *p == TAB)
5490 	    {
5491 		if (*p != TAB && *needclr)
5492 		{
5493 		    // remove any text still there from the command
5494 		    msg_clr_eos();
5495 		    *needclr = FALSE;
5496 		}
5497 		msg_putchar_attr(*p, echo_attr);
5498 	    }
5499 	    else
5500 	    {
5501 		if (has_mbyte)
5502 		{
5503 		    int i = (*mb_ptr2len)(p);
5504 
5505 		    (void)msg_outtrans_len_attr(p, i, echo_attr);
5506 		    p += i - 1;
5507 		}
5508 		else
5509 		    (void)msg_outtrans_len_attr(p, 1, echo_attr);
5510 	    }
5511 	}
5512     vim_free(tofree);
5513 }
5514 
5515 /*
5516  * ":echo expr1 ..."	print each argument separated with a space, add a
5517  *			newline at the end.
5518  * ":echon expr1 ..."	print each argument plain.
5519  */
5520     void
5521 ex_echo(exarg_T *eap)
5522 {
5523     char_u	*arg = eap->arg;
5524     typval_T	rettv;
5525     char_u	*p;
5526     int		needclr = TRUE;
5527     int		atstart = TRUE;
5528     int		did_emsg_before = did_emsg;
5529     int		called_emsg_before = called_emsg;
5530     evalarg_T	evalarg;
5531 
5532     fill_evalarg_from_eap(&evalarg, eap, eap->skip);
5533 
5534     if (eap->skip)
5535 	++emsg_skip;
5536     while ((!ends_excmd2(eap->cmd, arg) || *arg == '"') && !got_int)
5537     {
5538 	// If eval1() causes an error message the text from the command may
5539 	// still need to be cleared. E.g., "echo 22,44".
5540 	need_clr_eos = needclr;
5541 
5542 	p = arg;
5543 	if (eval1(&arg, &rettv, &evalarg) == FAIL)
5544 	{
5545 	    /*
5546 	     * Report the invalid expression unless the expression evaluation
5547 	     * has been cancelled due to an aborting error, an interrupt, or an
5548 	     * exception.
5549 	     */
5550 	    if (!aborting() && did_emsg == did_emsg_before
5551 					  && called_emsg == called_emsg_before)
5552 		semsg(_(e_invexpr2), p);
5553 	    need_clr_eos = FALSE;
5554 	    break;
5555 	}
5556 	need_clr_eos = FALSE;
5557 
5558 	if (!eap->skip)
5559 	    echo_one(&rettv, eap->cmdidx == CMD_echo, &atstart, &needclr);
5560 
5561 	clear_tv(&rettv);
5562 	arg = skipwhite(arg);
5563     }
5564     eap->nextcmd = check_nextcmd(arg);
5565     clear_evalarg(&evalarg, eap);
5566 
5567     if (eap->skip)
5568 	--emsg_skip;
5569     else
5570     {
5571 	// remove text that may still be there from the command
5572 	if (needclr)
5573 	    msg_clr_eos();
5574 	if (eap->cmdidx == CMD_echo)
5575 	    msg_end();
5576     }
5577 }
5578 
5579 /*
5580  * ":echohl {name}".
5581  */
5582     void
5583 ex_echohl(exarg_T *eap)
5584 {
5585     echo_attr = syn_name2attr(eap->arg);
5586 }
5587 
5588 /*
5589  * Returns the :echo attribute
5590  */
5591     int
5592 get_echo_attr(void)
5593 {
5594     return echo_attr;
5595 }
5596 
5597 /*
5598  * ":execute expr1 ..."	execute the result of an expression.
5599  * ":echomsg expr1 ..."	Print a message
5600  * ":echoerr expr1 ..."	Print an error
5601  * Each gets spaces around each argument and a newline at the end for
5602  * echo commands
5603  */
5604     void
5605 ex_execute(exarg_T *eap)
5606 {
5607     char_u	*arg = eap->arg;
5608     typval_T	rettv;
5609     int		ret = OK;
5610     char_u	*p;
5611     garray_T	ga;
5612     int		len;
5613 
5614     ga_init2(&ga, 1, 80);
5615 
5616     if (eap->skip)
5617 	++emsg_skip;
5618     while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
5619     {
5620 	ret = eval1_emsg(&arg, &rettv, eap);
5621 	if (ret == FAIL)
5622 	    break;
5623 
5624 	if (!eap->skip)
5625 	{
5626 	    char_u   buf[NUMBUFLEN];
5627 
5628 	    if (eap->cmdidx == CMD_execute)
5629 	    {
5630 		if (rettv.v_type == VAR_CHANNEL || rettv.v_type == VAR_JOB)
5631 		{
5632 		    emsg(_(e_inval_string));
5633 		    p = NULL;
5634 		}
5635 		else
5636 		    p = tv_get_string_buf(&rettv, buf);
5637 	    }
5638 	    else
5639 		p = tv_stringify(&rettv, buf);
5640 	    if (p == NULL)
5641 	    {
5642 		clear_tv(&rettv);
5643 		ret = FAIL;
5644 		break;
5645 	    }
5646 	    len = (int)STRLEN(p);
5647 	    if (ga_grow(&ga, len + 2) == FAIL)
5648 	    {
5649 		clear_tv(&rettv);
5650 		ret = FAIL;
5651 		break;
5652 	    }
5653 	    if (ga.ga_len)
5654 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
5655 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
5656 	    ga.ga_len += len;
5657 	}
5658 
5659 	clear_tv(&rettv);
5660 	arg = skipwhite(arg);
5661     }
5662 
5663     if (ret != FAIL && ga.ga_data != NULL)
5664     {
5665 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
5666 	{
5667 	    // Mark the already saved text as finishing the line, so that what
5668 	    // follows is displayed on a new line when scrolling back at the
5669 	    // more prompt.
5670 	    msg_sb_eol();
5671 	}
5672 
5673 	if (eap->cmdidx == CMD_echomsg)
5674 	{
5675 	    msg_attr(ga.ga_data, echo_attr);
5676 	    out_flush();
5677 	}
5678 	else if (eap->cmdidx == CMD_echoerr)
5679 	{
5680 	    int		save_did_emsg = did_emsg;
5681 
5682 	    // We don't want to abort following commands, restore did_emsg.
5683 	    emsg(ga.ga_data);
5684 	    if (!force_abort)
5685 		did_emsg = save_did_emsg;
5686 	}
5687 	else if (eap->cmdidx == CMD_execute)
5688 	    do_cmdline((char_u *)ga.ga_data,
5689 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
5690     }
5691 
5692     ga_clear(&ga);
5693 
5694     if (eap->skip)
5695 	--emsg_skip;
5696 
5697     eap->nextcmd = check_nextcmd(arg);
5698 }
5699 
5700 /*
5701  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
5702  * "arg" points to the "&" or '+' when called, to "option" when returning.
5703  * Returns NULL when no option name found.  Otherwise pointer to the char
5704  * after the option name.
5705  */
5706     char_u *
5707 find_option_end(char_u **arg, int *opt_flags)
5708 {
5709     char_u	*p = *arg;
5710 
5711     ++p;
5712     if (*p == 'g' && p[1] == ':')
5713     {
5714 	*opt_flags = OPT_GLOBAL;
5715 	p += 2;
5716     }
5717     else if (*p == 'l' && p[1] == ':')
5718     {
5719 	*opt_flags = OPT_LOCAL;
5720 	p += 2;
5721     }
5722     else
5723 	*opt_flags = 0;
5724 
5725     if (!ASCII_ISALPHA(*p))
5726 	return NULL;
5727     *arg = p;
5728 
5729     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
5730 	p += 4;	    // termcap option
5731     else
5732 	while (ASCII_ISALPHA(*p))
5733 	    ++p;
5734     return p;
5735 }
5736 
5737 /*
5738  * Display script name where an item was last set.
5739  * Should only be invoked when 'verbose' is non-zero.
5740  */
5741     void
5742 last_set_msg(sctx_T script_ctx)
5743 {
5744     char_u *p;
5745 
5746     if (script_ctx.sc_sid != 0)
5747     {
5748 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
5749 	if (p != NULL)
5750 	{
5751 	    verbose_enter();
5752 	    msg_puts(_("\n\tLast set from "));
5753 	    msg_puts((char *)p);
5754 	    if (script_ctx.sc_lnum > 0)
5755 	    {
5756 		msg_puts(_(line_msg));
5757 		msg_outnum((long)script_ctx.sc_lnum);
5758 	    }
5759 	    verbose_leave();
5760 	    vim_free(p);
5761 	}
5762     }
5763 }
5764 
5765 #endif // FEAT_EVAL
5766 
5767 /*
5768  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
5769  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
5770  * "flags" can be "g" to do a global substitute.
5771  * Returns an allocated string, NULL for error.
5772  */
5773     char_u *
5774 do_string_sub(
5775     char_u	*str,
5776     char_u	*pat,
5777     char_u	*sub,
5778     typval_T	*expr,
5779     char_u	*flags)
5780 {
5781     int		sublen;
5782     regmatch_T	regmatch;
5783     int		i;
5784     int		do_all;
5785     char_u	*tail;
5786     char_u	*end;
5787     garray_T	ga;
5788     char_u	*ret;
5789     char_u	*save_cpo;
5790     char_u	*zero_width = NULL;
5791 
5792     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
5793     save_cpo = p_cpo;
5794     p_cpo = empty_option;
5795 
5796     ga_init2(&ga, 1, 200);
5797 
5798     do_all = (flags[0] == 'g');
5799 
5800     regmatch.rm_ic = p_ic;
5801     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
5802     if (regmatch.regprog != NULL)
5803     {
5804 	tail = str;
5805 	end = str + STRLEN(str);
5806 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
5807 	{
5808 	    // Skip empty match except for first match.
5809 	    if (regmatch.startp[0] == regmatch.endp[0])
5810 	    {
5811 		if (zero_width == regmatch.startp[0])
5812 		{
5813 		    // avoid getting stuck on a match with an empty string
5814 		    i = mb_ptr2len(tail);
5815 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
5816 								   (size_t)i);
5817 		    ga.ga_len += i;
5818 		    tail += i;
5819 		    continue;
5820 		}
5821 		zero_width = regmatch.startp[0];
5822 	    }
5823 
5824 	    /*
5825 	     * Get some space for a temporary buffer to do the substitution
5826 	     * into.  It will contain:
5827 	     * - The text up to where the match is.
5828 	     * - The substituted text.
5829 	     * - The text after the match.
5830 	     */
5831 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
5832 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
5833 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
5834 	    {
5835 		ga_clear(&ga);
5836 		break;
5837 	    }
5838 
5839 	    // copy the text up to where the match is
5840 	    i = (int)(regmatch.startp[0] - tail);
5841 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
5842 	    // add the substituted text
5843 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
5844 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
5845 	    ga.ga_len += i + sublen - 1;
5846 	    tail = regmatch.endp[0];
5847 	    if (*tail == NUL)
5848 		break;
5849 	    if (!do_all)
5850 		break;
5851 	}
5852 
5853 	if (ga.ga_data != NULL)
5854 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
5855 
5856 	vim_regfree(regmatch.regprog);
5857     }
5858 
5859     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
5860     ga_clear(&ga);
5861     if (p_cpo == empty_option)
5862 	p_cpo = save_cpo;
5863     else
5864 	// Darn, evaluating {sub} expression or {expr} changed the value.
5865 	free_string_option(save_cpo);
5866 
5867     return ret;
5868 }
5869