xref: /vim-8.2.3635/src/eval.c (revision ba02e472)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * eval.c: Expression evaluation.
12  */
13 #define USING_FLOAT_STUFF
14 
15 #include "vim.h"
16 
17 #if defined(FEAT_EVAL) || defined(PROTO)
18 
19 #ifdef VMS
20 # include <float.h>
21 #endif
22 
23 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
24 
25 /*
26  * When recursively copying lists and dicts we need to remember which ones we
27  * have done to avoid endless recursiveness.  This unique ID is used for that.
28  * The last bit is used for previous_funccal, ignored when comparing.
29  */
30 static int current_copyID = 0;
31 
32 /*
33  * Info used by a ":for" loop.
34  */
35 typedef struct
36 {
37     int		fi_semicolon;	// TRUE if ending in '; var]'
38     int		fi_varcount;	// nr of variables in the list
39     int		fi_break_count;	// nr of line breaks encountered
40     listwatch_T	fi_lw;		// keep an eye on the item used.
41     list_T	*fi_list;	// list being used
42     int		fi_bi;		// index of blob
43     blob_T	*fi_blob;	// blob being used
44     char_u	*fi_string;	// copy of string being used
45     int		fi_byte_idx;	// byte index in fi_string
46 } forinfo_T;
47 
48 static int eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
49 static int eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
50 static int eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
51 static int eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
52 static int eval6(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int want_string);
53 static int eval7t(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 static char_u *eval_next_line(evalarg_T *evalarg);
60 
61 /*
62  * Return "n1" divided by "n2", taking care of dividing by zero.
63  * If "failed" is not NULL set it to TRUE when dividing by zero fails.
64  */
65 	varnumber_T
66 num_divide(varnumber_T n1, varnumber_T n2, int *failed)
67 {
68     varnumber_T	result;
69 
70     if (n2 == 0)
71     {
72 	if (in_vim9script())
73 	{
74 	    emsg(_(e_divide_by_zero));
75 	    if (failed != NULL)
76 		*failed = TRUE;
77 	}
78 	if (n1 == 0)
79 	    result = VARNUM_MIN; // similar to NaN
80 	else if (n1 < 0)
81 	    result = -VARNUM_MAX;
82 	else
83 	    result = VARNUM_MAX;
84     }
85     else
86 	result = n1 / n2;
87 
88     return result;
89 }
90 
91 /*
92  * Return "n1" modulus "n2", taking care of dividing by zero.
93  * If "failed" is not NULL set it to TRUE when dividing by zero fails.
94  */
95 	varnumber_T
96 num_modulus(varnumber_T n1, varnumber_T n2, int *failed)
97 {
98     if (n2 == 0 && in_vim9script())
99     {
100 	emsg(_(e_divide_by_zero));
101 	if (failed != NULL)
102 	    *failed = TRUE;
103     }
104     return (n2 == 0) ? 0 : (n1 % n2);
105 }
106 
107 /*
108  * Initialize the global and v: variables.
109  */
110     void
111 eval_init(void)
112 {
113     evalvars_init();
114     func_init();
115 
116 #ifdef EBCDIC
117     /*
118      * Sort the function table, to enable binary search.
119      */
120     sortFunctions();
121 #endif
122 }
123 
124 #if defined(EXITFREE) || defined(PROTO)
125     void
126 eval_clear(void)
127 {
128     evalvars_clear();
129     free_scriptnames();  // must come after evalvars_clear().
130     free_locales();
131 
132     // autoloaded script names
133     free_autoload_scriptnames();
134 
135     // unreferenced lists and dicts
136     (void)garbage_collect(FALSE);
137 
138     // functions not garbage collected
139     free_all_functions();
140 }
141 #endif
142 
143     void
144 fill_evalarg_from_eap(evalarg_T *evalarg, exarg_T *eap, int skip)
145 {
146     CLEAR_FIELD(*evalarg);
147     evalarg->eval_flags = skip ? 0 : EVAL_EVALUATE;
148     if (eap != NULL)
149     {
150 	evalarg->eval_cstack = eap->cstack;
151 	if (getline_equal(eap->getline, eap->cookie, getsourceline))
152 	{
153 	    evalarg->eval_getline = eap->getline;
154 	    evalarg->eval_cookie = eap->cookie;
155 	}
156     }
157 }
158 
159 /*
160  * Top level evaluation function, returning a boolean.
161  * Sets "error" to TRUE if there was an error.
162  * Return TRUE or FALSE.
163  */
164     int
165 eval_to_bool(
166     char_u	*arg,
167     int		*error,
168     exarg_T	*eap,
169     int		skip)	    // only parse, don't execute
170 {
171     typval_T	tv;
172     varnumber_T	retval = FALSE;
173     evalarg_T	evalarg;
174 
175     fill_evalarg_from_eap(&evalarg, eap, skip);
176 
177     if (skip)
178 	++emsg_skip;
179     if (eval0(arg, &tv, eap, &evalarg) == FAIL)
180 	*error = TRUE;
181     else
182     {
183 	*error = FALSE;
184 	if (!skip)
185 	{
186 	    if (in_vim9script())
187 		retval = tv_get_bool_chk(&tv, error);
188 	    else
189 		retval = (tv_get_number_chk(&tv, error) != 0);
190 	    clear_tv(&tv);
191 	}
192     }
193     if (skip)
194 	--emsg_skip;
195     clear_evalarg(&evalarg, eap);
196 
197     return (int)retval;
198 }
199 
200 /*
201  * Call eval1() and give an error message if not done at a lower level.
202  */
203     static int
204 eval1_emsg(char_u **arg, typval_T *rettv, exarg_T *eap)
205 {
206     char_u	*start = *arg;
207     int		ret;
208     int		did_emsg_before = did_emsg;
209     int		called_emsg_before = called_emsg;
210     evalarg_T	evalarg;
211 
212     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
213 
214     ret = eval1(arg, rettv, &evalarg);
215     if (ret == FAIL)
216     {
217 	// Report the invalid expression unless the expression evaluation has
218 	// been cancelled due to an aborting error, an interrupt, or an
219 	// exception, or we already gave a more specific error.
220 	// Also check called_emsg for when using assert_fails().
221 	if (!aborting() && did_emsg == did_emsg_before
222 					  && called_emsg == called_emsg_before)
223 	    semsg(_(e_invalid_expression_str), start);
224     }
225     clear_evalarg(&evalarg, eap);
226     return ret;
227 }
228 
229 /*
230  * Return whether a typval is a valid expression to pass to eval_expr_typval()
231  * or eval_expr_to_bool().  An empty string returns FALSE;
232  */
233     int
234 eval_expr_valid_arg(typval_T *tv)
235 {
236     return tv->v_type != VAR_UNKNOWN
237 	    && (tv->v_type != VAR_STRING
238 		  || (tv->vval.v_string != NULL && *tv->vval.v_string != NUL));
239 }
240 
241 /*
242  * Evaluate an expression, which can be a function, partial or string.
243  * Pass arguments "argv[argc]".
244  * Return the result in "rettv" and OK or FAIL.
245  */
246     int
247 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
248 {
249     char_u	*s;
250     char_u	buf[NUMBUFLEN];
251     funcexe_T	funcexe;
252 
253     if (expr->v_type == VAR_FUNC)
254     {
255 	s = expr->vval.v_string;
256 	if (s == NULL || *s == NUL)
257 	    return FAIL;
258 	CLEAR_FIELD(funcexe);
259 	funcexe.evaluate = TRUE;
260 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
261 	    return FAIL;
262     }
263     else if (expr->v_type == VAR_PARTIAL)
264     {
265 	partial_T   *partial = expr->vval.v_partial;
266 
267 	if (partial == NULL)
268 	    return FAIL;
269 
270 	if (partial->pt_func != NULL
271 			  && partial->pt_func->uf_def_status != UF_NOT_COMPILED)
272 	{
273 	    if (call_def_function(partial->pt_func, argc, argv,
274 						       partial, rettv) == FAIL)
275 		return FAIL;
276 	}
277 	else
278 	{
279 	    s = partial_name(partial);
280 	    if (s == NULL || *s == NUL)
281 		return FAIL;
282 	    CLEAR_FIELD(funcexe);
283 	    funcexe.evaluate = TRUE;
284 	    funcexe.partial = partial;
285 	    if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
286 		return FAIL;
287 	}
288     }
289     else if (expr->v_type == VAR_INSTR)
290     {
291 	return exe_typval_instr(expr, rettv);
292     }
293     else
294     {
295 	s = tv_get_string_buf_chk(expr, buf);
296 	if (s == NULL)
297 	    return FAIL;
298 	s = skipwhite(s);
299 	if (eval1_emsg(&s, rettv, NULL) == FAIL)
300 	    return FAIL;
301 	if (*skipwhite(s) != NUL)  // check for trailing chars after expr
302 	{
303 	    clear_tv(rettv);
304 	    semsg(_(e_invalid_expression_str), s);
305 	    return FAIL;
306 	}
307     }
308     return OK;
309 }
310 
311 /*
312  * Like eval_to_bool() but using a typval_T instead of a string.
313  * Works for string, funcref and partial.
314  */
315     int
316 eval_expr_to_bool(typval_T *expr, int *error)
317 {
318     typval_T	rettv;
319     int		res;
320 
321     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
322     {
323 	*error = TRUE;
324 	return FALSE;
325     }
326     res = (tv_get_bool_chk(&rettv, error) != 0);
327     clear_tv(&rettv);
328     return res;
329 }
330 
331 /*
332  * Top level evaluation function, returning a string.  If "skip" is TRUE,
333  * only parsing to "nextcmd" is done, without reporting errors.  Return
334  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
335  */
336     char_u *
337 eval_to_string_skip(
338     char_u	*arg,
339     exarg_T	*eap,
340     int		skip)	    // only parse, don't execute
341 {
342     typval_T	tv;
343     char_u	*retval;
344     evalarg_T	evalarg;
345 
346     fill_evalarg_from_eap(&evalarg, eap, skip);
347     if (skip)
348 	++emsg_skip;
349     if (eval0(arg, &tv, eap, &evalarg) == FAIL || skip)
350 	retval = NULL;
351     else
352     {
353 	retval = vim_strsave(tv_get_string(&tv));
354 	clear_tv(&tv);
355     }
356     if (skip)
357 	--emsg_skip;
358     clear_evalarg(&evalarg, eap);
359 
360     return retval;
361 }
362 
363 /*
364  * Skip over an expression at "*pp".
365  * Return FAIL for an error, OK otherwise.
366  */
367     int
368 skip_expr(char_u **pp, evalarg_T *evalarg)
369 {
370     typval_T	rettv;
371 
372     *pp = skipwhite(*pp);
373     return eval1(pp, &rettv, evalarg);
374 }
375 
376 /*
377  * Skip over an expression at "*arg".
378  * If in Vim9 script and line breaks are encountered, the lines are
379  * concatenated.  "evalarg->eval_tofree" will be set accordingly.
380  * "arg" is advanced to just after the expression.
381  * "start" is set to the start of the expression, "end" to just after the end.
382  * Also when the expression is copied to allocated memory.
383  * Return FAIL for an error, OK otherwise.
384  */
385     int
386 skip_expr_concatenate(
387 	char_u	    **arg,
388 	char_u	    **start,
389 	char_u	    **end,
390 	evalarg_T   *evalarg)
391 {
392     typval_T	rettv;
393     int		res;
394     int		vim9script = in_vim9script();
395     garray_T    *gap = evalarg == NULL ? NULL : &evalarg->eval_ga;
396     garray_T    *freegap = evalarg == NULL ? NULL : &evalarg->eval_freega;
397     int		save_flags = evalarg == NULL ? 0 : evalarg->eval_flags;
398     int		evaluate = evalarg == NULL
399 			       ? FALSE : (evalarg->eval_flags & EVAL_EVALUATE);
400 
401     if (vim9script && evaluate
402 	       && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
403     {
404 	ga_init2(gap, sizeof(char_u *), 10);
405 	// leave room for "start"
406 	if (ga_grow(gap, 1) == OK)
407 	    ++gap->ga_len;
408 	ga_init2(freegap, sizeof(char_u *), 10);
409     }
410     *start = *arg;
411 
412     // Don't evaluate the expression.
413     if (evalarg != NULL)
414 	evalarg->eval_flags &= ~EVAL_EVALUATE;
415     *arg = skipwhite(*arg);
416     res = eval1(arg, &rettv, evalarg);
417     *end = *arg;
418     if (evalarg != NULL)
419 	evalarg->eval_flags = save_flags;
420 
421     if (vim9script && evaluate
422 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
423     {
424 	if (evalarg->eval_ga.ga_len == 1)
425 	{
426 	    // just the one line, no need to concatenate
427 	    ga_clear(gap);
428 	    gap->ga_itemsize = 0;
429 	}
430 	else
431 	{
432 	    char_u	    *p;
433 	    size_t	    endoff = STRLEN(*arg);
434 
435 	    // Line breaks encountered, concatenate all the lines.
436 	    *((char_u **)gap->ga_data) = *start;
437 	    p = ga_concat_strings(gap, " ");
438 
439 	    // free the lines only when using getsourceline()
440 	    if (evalarg->eval_cookie != NULL)
441 	    {
442 		// Do not free the first line, the caller can still use it.
443 		*((char_u **)gap->ga_data) = NULL;
444 		// Do not free the last line, "arg" points into it, free it
445 		// later.
446 		vim_free(evalarg->eval_tofree);
447 		evalarg->eval_tofree =
448 				    ((char_u **)gap->ga_data)[gap->ga_len - 1];
449 		((char_u **)gap->ga_data)[gap->ga_len - 1] = NULL;
450 		ga_clear_strings(gap);
451 	    }
452 	    else
453 	    {
454 		ga_clear(gap);
455 
456 		// free lines that were explicitly marked for freeing
457 		ga_clear_strings(freegap);
458 	    }
459 
460 	    gap->ga_itemsize = 0;
461 	    if (p == NULL)
462 		return FAIL;
463 	    *start = p;
464 	    vim_free(evalarg->eval_tofree_lambda);
465 	    evalarg->eval_tofree_lambda = p;
466 	    // Compute "end" relative to the end.
467 	    *end = *start + STRLEN(*start) - endoff;
468 	}
469     }
470 
471     return res;
472 }
473 
474 /*
475  * Convert "tv" to a string.
476  * When "convert" is TRUE convert a List into a sequence of lines and convert
477  * a Float to a String.
478  * Returns an allocated string (NULL when out of memory).
479  */
480     char_u *
481 typval2string(typval_T *tv, int convert)
482 {
483     garray_T	ga;
484     char_u	*retval;
485 #ifdef FEAT_FLOAT
486     char_u	numbuf[NUMBUFLEN];
487 #endif
488 
489     if (convert && tv->v_type == VAR_LIST)
490     {
491 	ga_init2(&ga, (int)sizeof(char), 80);
492 	if (tv->vval.v_list != NULL)
493 	{
494 	    list_join(&ga, tv->vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
495 	    if (tv->vval.v_list->lv_len > 0)
496 		ga_append(&ga, NL);
497 	}
498 	ga_append(&ga, NUL);
499 	retval = (char_u *)ga.ga_data;
500     }
501 #ifdef FEAT_FLOAT
502     else if (convert && tv->v_type == VAR_FLOAT)
503     {
504 	vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
505 	retval = vim_strsave(numbuf);
506     }
507 #endif
508     else
509 	retval = vim_strsave(tv_get_string(tv));
510     return retval;
511 }
512 
513 /*
514  * Top level evaluation function, returning a string.  Does not handle line
515  * breaks.
516  * When "convert" is TRUE convert a List into a sequence of lines and convert
517  * a Float to a String.
518  * Return pointer to allocated memory, or NULL for failure.
519  */
520     char_u *
521 eval_to_string_eap(
522     char_u	*arg,
523     int		convert,
524     exarg_T	*eap)
525 {
526     typval_T	tv;
527     char_u	*retval;
528     evalarg_T	evalarg;
529 
530     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
531     if (eval0(arg, &tv, NULL, &evalarg) == FAIL)
532 	retval = NULL;
533     else
534     {
535 	retval = typval2string(&tv, convert);
536 	clear_tv(&tv);
537     }
538     clear_evalarg(&evalarg, NULL);
539 
540     return retval;
541 }
542 
543     char_u *
544 eval_to_string(
545     char_u	*arg,
546     int		convert)
547 {
548     return eval_to_string_eap(arg, convert, NULL);
549 }
550 
551 /*
552  * Call eval_to_string() without using current local variables and using
553  * textwinlock.  When "use_sandbox" is TRUE use the sandbox.
554  * Use legacy Vim script syntax.
555  */
556     char_u *
557 eval_to_string_safe(
558     char_u	*arg,
559     int		use_sandbox)
560 {
561     char_u	*retval;
562     funccal_entry_T funccal_entry;
563     int		save_sc_version = current_sctx.sc_version;
564 
565     current_sctx.sc_version = 1;
566     save_funccal(&funccal_entry);
567     if (use_sandbox)
568 	++sandbox;
569     ++textwinlock;
570     retval = eval_to_string(arg, FALSE);
571     if (use_sandbox)
572 	--sandbox;
573     --textwinlock;
574     restore_funccal();
575     current_sctx.sc_version = save_sc_version;
576     return retval;
577 }
578 
579 /*
580  * Top level evaluation function, returning a number.
581  * Evaluates "expr" silently.
582  * Returns -1 for an error.
583  */
584     varnumber_T
585 eval_to_number(char_u *expr)
586 {
587     typval_T	rettv;
588     varnumber_T	retval;
589     char_u	*p = skipwhite(expr);
590 
591     ++emsg_off;
592 
593     if (eval1(&p, &rettv, &EVALARG_EVALUATE) == FAIL)
594 	retval = -1;
595     else
596     {
597 	retval = tv_get_number_chk(&rettv, NULL);
598 	clear_tv(&rettv);
599     }
600     --emsg_off;
601 
602     return retval;
603 }
604 
605 /*
606  * Top level evaluation function.
607  * Returns an allocated typval_T with the result.
608  * Returns NULL when there is an error.
609  */
610     typval_T *
611 eval_expr(char_u *arg, exarg_T *eap)
612 {
613     typval_T	*tv;
614     evalarg_T	evalarg;
615 
616     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
617 
618     tv = ALLOC_ONE(typval_T);
619     if (tv != NULL && eval0(arg, tv, eap, &evalarg) == FAIL)
620 	VIM_CLEAR(tv);
621 
622     clear_evalarg(&evalarg, eap);
623     return tv;
624 }
625 
626 /*
627  * Call some Vim script function and return the result in "*rettv".
628  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
629  * should have type VAR_UNKNOWN.
630  * Returns OK or FAIL.
631  */
632     int
633 call_vim_function(
634     char_u      *func,
635     int		argc,
636     typval_T	*argv,
637     typval_T	*rettv)
638 {
639     int		ret;
640     funcexe_T	funcexe;
641 
642     rettv->v_type = VAR_UNKNOWN;		// clear_tv() uses this
643     CLEAR_FIELD(funcexe);
644     funcexe.firstline = curwin->w_cursor.lnum;
645     funcexe.lastline = curwin->w_cursor.lnum;
646     funcexe.evaluate = TRUE;
647     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
648     if (ret == FAIL)
649 	clear_tv(rettv);
650 
651     return ret;
652 }
653 
654 /*
655  * Call Vim script function "func" and return the result as a number.
656  * Returns -1 when calling the function fails.
657  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
658  * have type VAR_UNKNOWN.
659  */
660     varnumber_T
661 call_func_retnr(
662     char_u      *func,
663     int		argc,
664     typval_T	*argv)
665 {
666     typval_T	rettv;
667     varnumber_T	retval;
668 
669     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
670 	return -1;
671 
672     retval = tv_get_number_chk(&rettv, NULL);
673     clear_tv(&rettv);
674     return retval;
675 }
676 
677 /*
678  * Call Vim script function like call_func_retnr() and drop the result.
679  * Returns FAIL when calling the function fails.
680  */
681     int
682 call_func_noret(
683     char_u      *func,
684     int		argc,
685     typval_T	*argv)
686 {
687     typval_T	rettv;
688 
689     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
690 	return FAIL;
691     clear_tv(&rettv);
692     return OK;
693 }
694 
695 /*
696  * Call Vim script function "func" and return the result as a string.
697  * Uses "argv" and "argc" as call_func_retnr().
698  * Returns NULL when calling the function fails.
699  */
700     void *
701 call_func_retstr(
702     char_u      *func,
703     int		argc,
704     typval_T	*argv)
705 {
706     typval_T	rettv;
707     char_u	*retval;
708 
709     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
710 	return NULL;
711 
712     retval = vim_strsave(tv_get_string(&rettv));
713     clear_tv(&rettv);
714     return retval;
715 }
716 
717 /*
718  * Call Vim script function "func" and return the result as a List.
719  * Uses "argv" and "argc" as call_func_retnr().
720  * Returns NULL when there is something wrong.
721  */
722     void *
723 call_func_retlist(
724     char_u      *func,
725     int		argc,
726     typval_T	*argv)
727 {
728     typval_T	rettv;
729 
730     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
731 	return NULL;
732 
733     if (rettv.v_type != VAR_LIST)
734     {
735 	clear_tv(&rettv);
736 	return NULL;
737     }
738 
739     return rettv.vval.v_list;
740 }
741 
742 #ifdef FEAT_FOLDING
743 /*
744  * Evaluate "arg", which is 'foldexpr'.
745  * Note: caller must set "curwin" to match "arg".
746  * Returns the foldlevel, and any character preceding it in "*cp".  Doesn't
747  * give error messages.
748  */
749     int
750 eval_foldexpr(char_u *arg, int *cp)
751 {
752     typval_T	tv;
753     varnumber_T	retval;
754     char_u	*s;
755     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
756 								   OPT_LOCAL);
757 
758     ++emsg_off;
759     if (use_sandbox)
760 	++sandbox;
761     ++textwinlock;
762     *cp = NUL;
763     if (eval0(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
764 	retval = 0;
765     else
766     {
767 	// If the result is a number, just return the number.
768 	if (tv.v_type == VAR_NUMBER)
769 	    retval = tv.vval.v_number;
770 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
771 	    retval = 0;
772 	else
773 	{
774 	    // If the result is a string, check if there is a non-digit before
775 	    // the number.
776 	    s = tv.vval.v_string;
777 	    if (!VIM_ISDIGIT(*s) && *s != '-')
778 		*cp = *s++;
779 	    retval = atol((char *)s);
780 	}
781 	clear_tv(&tv);
782     }
783     --emsg_off;
784     if (use_sandbox)
785 	--sandbox;
786     --textwinlock;
787     clear_evalarg(&EVALARG_EVALUATE, NULL);
788 
789     return (int)retval;
790 }
791 #endif
792 
793 /*
794  * Get an lval: variable, Dict item or List item that can be assigned a value
795  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
796  * "name.key", "name.key[expr]" etc.
797  * Indexing only works if "name" is an existing List or Dictionary.
798  * "name" points to the start of the name.
799  * If "rettv" is not NULL it points to the value to be assigned.
800  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
801  * wrong; must end in space or cmd separator.
802  *
803  * flags:
804  *  GLV_QUIET:       do not give error messages
805  *  GLV_READ_ONLY:   will not change the variable
806  *  GLV_NO_AUTOLOAD: do not use script autoloading
807  *
808  * Returns a pointer to just after the name, including indexes.
809  * When an evaluation error occurs "lp->ll_name" is NULL;
810  * Returns NULL for a parsing error.  Still need to free items in "lp"!
811  */
812     char_u *
813 get_lval(
814     char_u	*name,
815     typval_T	*rettv,
816     lval_T	*lp,
817     int		unlet,
818     int		skip,
819     int		flags,	    // GLV_ values
820     int		fne_flags)  // flags for find_name_end()
821 {
822     char_u	*p;
823     char_u	*expr_start, *expr_end;
824     int		cc;
825     dictitem_T	*v;
826     typval_T	var1;
827     typval_T	var2;
828     int		empty1 = FALSE;
829     char_u	*key = NULL;
830     int		len;
831     hashtab_T	*ht = NULL;
832     int		quiet = flags & GLV_QUIET;
833     int		writing;
834 
835     // Clear everything in "lp".
836     CLEAR_POINTER(lp);
837 
838     if (skip || (flags & GLV_COMPILING))
839     {
840 	// When skipping or compiling just find the end of the name.
841 	lp->ll_name = name;
842 	lp->ll_name_end = find_name_end(name, NULL, NULL,
843 						      FNE_INCL_BR | fne_flags);
844 	return lp->ll_name_end;
845     }
846 
847     // Find the end of the name.
848     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
849     lp->ll_name_end = p;
850     if (expr_start != NULL)
851     {
852 	// Don't expand the name when we already know there is an error.
853 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
854 						    && *p != '[' && *p != '.')
855 	{
856 	    semsg(_(e_trailing_arg), p);
857 	    return NULL;
858 	}
859 
860 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
861 	if (lp->ll_exp_name == NULL)
862 	{
863 	    // Report an invalid expression in braces, unless the
864 	    // expression evaluation has been cancelled due to an
865 	    // aborting error, an interrupt, or an exception.
866 	    if (!aborting() && !quiet)
867 	    {
868 		emsg_severe = TRUE;
869 		semsg(_(e_invarg2), name);
870 		return NULL;
871 	    }
872 	}
873 	lp->ll_name = lp->ll_exp_name;
874     }
875     else
876     {
877 	lp->ll_name = name;
878 
879 	if (in_vim9script())
880 	{
881 	    // "a: type" is declaring variable "a" with a type, not "a:".
882 	    if (p == name + 2 && p[-1] == ':')
883 	    {
884 		--p;
885 		lp->ll_name_end = p;
886 	    }
887 	    if (*p == ':')
888 	    {
889 		scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);
890 		char_u	     *tp = skipwhite(p + 1);
891 
892 		if (tp == p + 1 && !quiet)
893 		{
894 		    semsg(_(e_white_space_required_after_str_str), ":", p);
895 		    return NULL;
896 		}
897 
898 		// parse the type after the name
899 		lp->ll_type = parse_type(&tp, &si->sn_type_list, !quiet);
900 		if (lp->ll_type == NULL && !quiet)
901 		    return NULL;
902 		lp->ll_name_end = tp;
903 	    }
904 	}
905     }
906 
907     // Without [idx] or .key we are done.
908     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
909 	return p;
910 
911     if (in_vim9script() && lval_root != NULL)
912     {
913 	// using local variable
914 	lp->ll_tv = lval_root;
915 	v = NULL;
916     }
917     else
918     {
919 	cc = *p;
920 	*p = NUL;
921 	// When we would write to the variable pass &ht and prevent autoload.
922 	writing = !(flags & GLV_READ_ONLY);
923 	v = find_var(lp->ll_name, writing ? &ht : NULL,
924 					 (flags & GLV_NO_AUTOLOAD) || writing);
925 	if (v == NULL && !quiet)
926 	    semsg(_(e_undefined_variable_str), lp->ll_name);
927 	*p = cc;
928 	if (v == NULL)
929 	    return NULL;
930 	lp->ll_tv = &v->di_tv;
931     }
932 
933     if (in_vim9script() && (flags & GLV_NO_DECL) == 0)
934     {
935 	if (!quiet)
936 	    semsg(_(e_variable_already_declared), lp->ll_name);
937 	return NULL;
938     }
939 
940     /*
941      * Loop until no more [idx] or .key is following.
942      */
943     var1.v_type = VAR_UNKNOWN;
944     var2.v_type = VAR_UNKNOWN;
945     while (*p == '[' || (*p == '.' && p[1] != '=' && p[1] != '.'))
946     {
947 	if (*p == '.' && lp->ll_tv->v_type != VAR_DICT)
948 	{
949 	    if (!quiet)
950 		semsg(_(e_dot_can_only_be_used_on_dictionary_str), name);
951 	    return NULL;
952 	}
953 	if (lp->ll_tv->v_type != VAR_LIST
954 		&& lp->ll_tv->v_type != VAR_DICT
955 		&& lp->ll_tv->v_type != VAR_BLOB)
956 	{
957 	    if (!quiet)
958 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
959 	    return NULL;
960 	}
961 
962 	// a NULL list/blob works like an empty list/blob, allocate one now.
963 	if (lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list == NULL)
964 	    rettv_list_alloc(lp->ll_tv);
965 	else if (lp->ll_tv->v_type == VAR_BLOB
966 					     && lp->ll_tv->vval.v_blob == NULL)
967 	    rettv_blob_alloc(lp->ll_tv);
968 
969 	if (lp->ll_range)
970 	{
971 	    if (!quiet)
972 		emsg(_("E708: [:] must come last"));
973 	    return NULL;
974 	}
975 
976 	if (in_vim9script() && lp->ll_valtype == NULL
977 		&& v != NULL
978 		&& lp->ll_tv == &v->di_tv
979 		&& ht != NULL && ht == get_script_local_ht())
980 	{
981 	    svar_T  *sv = find_typval_in_script(lp->ll_tv);
982 
983 	    // Vim9 script local variable: get the type
984 	    if (sv != NULL)
985 		lp->ll_valtype = sv->sv_type;
986 	}
987 
988 	len = -1;
989 	if (*p == '.')
990 	{
991 	    key = p + 1;
992 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
993 		;
994 	    if (len == 0)
995 	    {
996 		if (!quiet)
997 		    emsg(_(e_emptykey));
998 		return NULL;
999 	    }
1000 	    p = key + len;
1001 	}
1002 	else
1003 	{
1004 	    // Get the index [expr] or the first index [expr: ].
1005 	    p = skipwhite(p + 1);
1006 	    if (*p == ':')
1007 		empty1 = TRUE;
1008 	    else
1009 	    {
1010 		empty1 = FALSE;
1011 		if (eval1(&p, &var1, &EVALARG_EVALUATE) == FAIL)  // recursive!
1012 		    return NULL;
1013 		if (tv_get_string_chk(&var1) == NULL)
1014 		{
1015 		    // not a number or string
1016 		    clear_tv(&var1);
1017 		    return NULL;
1018 		}
1019 		p = skipwhite(p);
1020 	    }
1021 
1022 	    // Optionally get the second index [ :expr].
1023 	    if (*p == ':')
1024 	    {
1025 		if (lp->ll_tv->v_type == VAR_DICT)
1026 		{
1027 		    if (!quiet)
1028 			emsg(_(e_cannot_slice_dictionary));
1029 		    clear_tv(&var1);
1030 		    return NULL;
1031 		}
1032 		if (rettv != NULL
1033 			&& !(rettv->v_type == VAR_LIST
1034 						 && rettv->vval.v_list != NULL)
1035 			&& !(rettv->v_type == VAR_BLOB
1036 						&& rettv->vval.v_blob != NULL))
1037 		{
1038 		    if (!quiet)
1039 			emsg(_("E709: [:] requires a List or Blob value"));
1040 		    clear_tv(&var1);
1041 		    return NULL;
1042 		}
1043 		p = skipwhite(p + 1);
1044 		if (*p == ']')
1045 		    lp->ll_empty2 = TRUE;
1046 		else
1047 		{
1048 		    lp->ll_empty2 = FALSE;
1049 		    // recursive!
1050 		    if (eval1(&p, &var2, &EVALARG_EVALUATE) == FAIL)
1051 		    {
1052 			clear_tv(&var1);
1053 			return NULL;
1054 		    }
1055 		    if (tv_get_string_chk(&var2) == NULL)
1056 		    {
1057 			// not a number or string
1058 			clear_tv(&var1);
1059 			clear_tv(&var2);
1060 			return NULL;
1061 		    }
1062 		}
1063 		lp->ll_range = TRUE;
1064 	    }
1065 	    else
1066 		lp->ll_range = FALSE;
1067 
1068 	    if (*p != ']')
1069 	    {
1070 		if (!quiet)
1071 		    emsg(_(e_missbrac));
1072 		clear_tv(&var1);
1073 		clear_tv(&var2);
1074 		return NULL;
1075 	    }
1076 
1077 	    // Skip to past ']'.
1078 	    ++p;
1079 	}
1080 
1081 	if (lp->ll_tv->v_type == VAR_DICT)
1082 	{
1083 	    if (len == -1)
1084 	    {
1085 		// "[key]": get key from "var1"
1086 		key = tv_get_string_chk(&var1);	// is number or string
1087 		if (key == NULL)
1088 		{
1089 		    clear_tv(&var1);
1090 		    return NULL;
1091 		}
1092 	    }
1093 	    lp->ll_list = NULL;
1094 
1095 	    // a NULL dict is equivalent with an empty dict
1096 	    if (lp->ll_tv->vval.v_dict == NULL)
1097 	    {
1098 		lp->ll_tv->vval.v_dict = dict_alloc();
1099 		if (lp->ll_tv->vval.v_dict == NULL)
1100 		{
1101 		    clear_tv(&var1);
1102 		    return NULL;
1103 		}
1104 		++lp->ll_tv->vval.v_dict->dv_refcount;
1105 	    }
1106 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
1107 
1108 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
1109 
1110 	    // When assigning to a scope dictionary check that a function and
1111 	    // variable name is valid (only variable name unless it is l: or
1112 	    // g: dictionary). Disallow overwriting a builtin function.
1113 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
1114 	    {
1115 		int prevval;
1116 		int wrong;
1117 
1118 		if (len != -1)
1119 		{
1120 		    prevval = key[len];
1121 		    key[len] = NUL;
1122 		}
1123 		else
1124 		    prevval = 0; // avoid compiler warning
1125 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
1126 			       && rettv->v_type == VAR_FUNC
1127 			       && var_wrong_func_name(key, lp->ll_di == NULL))
1128 			|| !valid_varname(key, TRUE);
1129 		if (len != -1)
1130 		    key[len] = prevval;
1131 		if (wrong)
1132 		{
1133 		    clear_tv(&var1);
1134 		    return NULL;
1135 		}
1136 	    }
1137 
1138 	    if (lp->ll_valtype != NULL)
1139 		// use the type of the member
1140 		lp->ll_valtype = lp->ll_valtype->tt_member;
1141 
1142 	    if (lp->ll_di == NULL)
1143 	    {
1144 		// Can't add "v:" or "a:" variable.
1145 		if (lp->ll_dict == get_vimvar_dict()
1146 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
1147 		{
1148 		    semsg(_(e_illvar), name);
1149 		    clear_tv(&var1);
1150 		    return NULL;
1151 		}
1152 
1153 		// Key does not exist in dict: may need to add it.
1154 		if (*p == '[' || *p == '.' || unlet)
1155 		{
1156 		    if (!quiet)
1157 			semsg(_(e_dictkey), key);
1158 		    clear_tv(&var1);
1159 		    return NULL;
1160 		}
1161 		if (len == -1)
1162 		    lp->ll_newkey = vim_strsave(key);
1163 		else
1164 		    lp->ll_newkey = vim_strnsave(key, len);
1165 		clear_tv(&var1);
1166 		if (lp->ll_newkey == NULL)
1167 		    p = NULL;
1168 		break;
1169 	    }
1170 	    // existing variable, need to check if it can be changed
1171 	    else if ((flags & GLV_READ_ONLY) == 0
1172 			&& (var_check_ro(lp->ll_di->di_flags, name, FALSE)
1173 			  || var_check_lock(lp->ll_di->di_flags, name, FALSE)))
1174 	    {
1175 		clear_tv(&var1);
1176 		return NULL;
1177 	    }
1178 
1179 	    clear_tv(&var1);
1180 	    lp->ll_tv = &lp->ll_di->di_tv;
1181 	}
1182 	else if (lp->ll_tv->v_type == VAR_BLOB)
1183 	{
1184 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
1185 
1186 	    /*
1187 	     * Get the number and item for the only or first index of the List.
1188 	     */
1189 	    if (empty1)
1190 		lp->ll_n1 = 0;
1191 	    else
1192 		// is number or string
1193 		lp->ll_n1 = (long)tv_get_number(&var1);
1194 	    clear_tv(&var1);
1195 
1196 	    if (check_blob_index(bloblen, lp->ll_n1, quiet) == FAIL)
1197 	    {
1198 		clear_tv(&var2);
1199 		return NULL;
1200 	    }
1201 	    if (lp->ll_range && !lp->ll_empty2)
1202 	    {
1203 		lp->ll_n2 = (long)tv_get_number(&var2);
1204 		clear_tv(&var2);
1205 		if (check_blob_range(bloblen, lp->ll_n1, lp->ll_n2, quiet)
1206 								       == FAIL)
1207 		    return NULL;
1208 	    }
1209 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
1210 	    lp->ll_tv = NULL;
1211 	    break;
1212 	}
1213 	else
1214 	{
1215 	    /*
1216 	     * Get the number and item for the only or first index of the List.
1217 	     */
1218 	    if (empty1)
1219 		lp->ll_n1 = 0;
1220 	    else
1221 		// is number or string
1222 		lp->ll_n1 = (long)tv_get_number(&var1);
1223 	    clear_tv(&var1);
1224 
1225 	    lp->ll_dict = NULL;
1226 	    lp->ll_list = lp->ll_tv->vval.v_list;
1227 	    lp->ll_li = check_range_index_one(lp->ll_list, &lp->ll_n1, quiet);
1228 	    if (lp->ll_li == NULL)
1229 	    {
1230 		clear_tv(&var2);
1231 		return NULL;
1232 	    }
1233 
1234 	    if (lp->ll_valtype != NULL)
1235 		// use the type of the member
1236 		lp->ll_valtype = lp->ll_valtype->tt_member;
1237 
1238 	    /*
1239 	     * May need to find the item or absolute index for the second
1240 	     * index of a range.
1241 	     * When no index given: "lp->ll_empty2" is TRUE.
1242 	     * Otherwise "lp->ll_n2" is set to the second index.
1243 	     */
1244 	    if (lp->ll_range && !lp->ll_empty2)
1245 	    {
1246 		lp->ll_n2 = (long)tv_get_number(&var2);
1247 						    // is number or string
1248 		clear_tv(&var2);
1249 		if (check_range_index_two(lp->ll_list,
1250 					    &lp->ll_n1, lp->ll_li,
1251 					    &lp->ll_n2, quiet) == FAIL)
1252 		    return NULL;
1253 	    }
1254 
1255 	    lp->ll_tv = &lp->ll_li->li_tv;
1256 	}
1257     }
1258 
1259     clear_tv(&var1);
1260     lp->ll_name_end = p;
1261     return p;
1262 }
1263 
1264 /*
1265  * Clear lval "lp" that was filled by get_lval().
1266  */
1267     void
1268 clear_lval(lval_T *lp)
1269 {
1270     vim_free(lp->ll_exp_name);
1271     vim_free(lp->ll_newkey);
1272 }
1273 
1274 /*
1275  * Set a variable that was parsed by get_lval() to "rettv".
1276  * "endp" points to just after the parsed name.
1277  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
1278  * "%" for "%=", "." for ".=" or "=" for "=".
1279  */
1280     void
1281 set_var_lval(
1282     lval_T	*lp,
1283     char_u	*endp,
1284     typval_T	*rettv,
1285     int		copy,
1286     int		flags,	    // ASSIGN_CONST, ASSIGN_NO_DECL
1287     char_u	*op,
1288     int		var_idx)    // index for "let [a, b] = list"
1289 {
1290     int		cc;
1291     dictitem_T	*di;
1292 
1293     if (lp->ll_tv == NULL)
1294     {
1295 	cc = *endp;
1296 	*endp = NUL;
1297 	if (in_vim9script() && check_reserved_name(lp->ll_name) == FAIL)
1298 	    return;
1299 
1300 	if (lp->ll_blob != NULL)
1301 	{
1302 	    int	    error = FALSE, val;
1303 
1304 	    if (op != NULL && *op != '=')
1305 	    {
1306 		semsg(_(e_letwrong), op);
1307 		return;
1308 	    }
1309 	    if (value_check_lock(lp->ll_blob->bv_lock, lp->ll_name, FALSE))
1310 		return;
1311 
1312 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
1313 	    {
1314 		if (lp->ll_empty2)
1315 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
1316 
1317 		if (blob_set_range(lp->ll_blob, lp->ll_n1, lp->ll_n2,
1318 								rettv) == FAIL)
1319 		    return;
1320 	    }
1321 	    else
1322 	    {
1323 		val = (int)tv_get_number_chk(rettv, &error);
1324 		if (!error)
1325 		    blob_set_append(lp->ll_blob, lp->ll_n1, val);
1326 	    }
1327 	}
1328 	else if (op != NULL && *op != '=')
1329 	{
1330 	    typval_T tv;
1331 
1332 	    if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
1333 					     && (flags & ASSIGN_FOR_LOOP) == 0)
1334 	    {
1335 		emsg(_(e_cannot_mod));
1336 		*endp = cc;
1337 		return;
1338 	    }
1339 
1340 	    // handle +=, -=, *=, /=, %= and .=
1341 	    di = NULL;
1342 	    if (eval_variable(lp->ll_name, (int)STRLEN(lp->ll_name),
1343 					     &tv, &di, EVAL_VAR_VERBOSE) == OK)
1344 	    {
1345 		if ((di == NULL
1346 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
1347 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
1348 			&& tv_op(&tv, rettv, op) == OK)
1349 		    set_var_const(lp->ll_name, NULL, &tv, FALSE,
1350 							    ASSIGN_NO_DECL, 0);
1351 		clear_tv(&tv);
1352 	    }
1353 	}
1354 	else
1355 	{
1356 	    if (lp->ll_type != NULL && check_typval_arg_type(lp->ll_type, rettv,
1357 							      NULL, 0) == FAIL)
1358 		return;
1359 	    set_var_const(lp->ll_name, lp->ll_type, rettv, copy,
1360 							       flags, var_idx);
1361 	}
1362 	*endp = cc;
1363     }
1364     else if (value_check_lock(lp->ll_newkey == NULL
1365 		? lp->ll_tv->v_lock
1366 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
1367 	;
1368     else if (lp->ll_range)
1369     {
1370 	if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
1371 					     && (flags & ASSIGN_FOR_LOOP) == 0)
1372 	{
1373 	    emsg(_("E996: Cannot lock a range"));
1374 	    return;
1375 	}
1376 
1377 	(void)list_assign_range(lp->ll_list, rettv->vval.v_list,
1378 			 lp->ll_n1, lp->ll_n2, lp->ll_empty2, op, lp->ll_name);
1379     }
1380     else
1381     {
1382 	/*
1383 	 * Assign to a List or Dictionary item.
1384 	 */
1385 	if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
1386 					     && (flags & ASSIGN_FOR_LOOP) == 0)
1387 	{
1388 	    emsg(_("E996: Cannot lock a list or dict"));
1389 	    return;
1390 	}
1391 
1392 	if (lp->ll_valtype != NULL
1393 		    && check_typval_arg_type(lp->ll_valtype, rettv,
1394 							      NULL, 0) == FAIL)
1395 	    return;
1396 
1397 	if (lp->ll_newkey != NULL)
1398 	{
1399 	    if (op != NULL && *op != '=')
1400 	    {
1401 		semsg(_(e_dictkey), lp->ll_newkey);
1402 		return;
1403 	    }
1404 	    if (dict_wrong_func_name(lp->ll_tv->vval.v_dict, rettv,
1405 								lp->ll_newkey))
1406 		return;
1407 
1408 	    // Need to add an item to the Dictionary.
1409 	    di = dictitem_alloc(lp->ll_newkey);
1410 	    if (di == NULL)
1411 		return;
1412 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
1413 	    {
1414 		vim_free(di);
1415 		return;
1416 	    }
1417 	    lp->ll_tv = &di->di_tv;
1418 	}
1419 	else if (op != NULL && *op != '=')
1420 	{
1421 	    tv_op(lp->ll_tv, rettv, op);
1422 	    return;
1423 	}
1424 	else
1425 	    clear_tv(lp->ll_tv);
1426 
1427 	/*
1428 	 * Assign the value to the variable or list item.
1429 	 */
1430 	if (copy)
1431 	    copy_tv(rettv, lp->ll_tv);
1432 	else
1433 	{
1434 	    *lp->ll_tv = *rettv;
1435 	    lp->ll_tv->v_lock = 0;
1436 	    init_tv(rettv);
1437 	}
1438     }
1439 }
1440 
1441 /*
1442  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
1443  * and "tv1 .= tv2"
1444  * Returns OK or FAIL.
1445  */
1446     int
1447 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
1448 {
1449     varnumber_T	n;
1450     char_u	numbuf[NUMBUFLEN];
1451     char_u	*s;
1452     int		failed = FALSE;
1453 
1454     // Can't do anything with a Funcref or Dict on the right.
1455     // v:true and friends only work with "..=".
1456     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
1457 		    && ((tv2->v_type != VAR_BOOL && tv2->v_type != VAR_SPECIAL)
1458 								|| *op == '.'))
1459     {
1460 	switch (tv1->v_type)
1461 	{
1462 	    case VAR_UNKNOWN:
1463 	    case VAR_ANY:
1464 	    case VAR_VOID:
1465 	    case VAR_DICT:
1466 	    case VAR_FUNC:
1467 	    case VAR_PARTIAL:
1468 	    case VAR_BOOL:
1469 	    case VAR_SPECIAL:
1470 	    case VAR_JOB:
1471 	    case VAR_CHANNEL:
1472 	    case VAR_INSTR:
1473 		break;
1474 
1475 	    case VAR_BLOB:
1476 		if (*op != '+' || tv2->v_type != VAR_BLOB)
1477 		    break;
1478 		// BLOB += BLOB
1479 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
1480 		{
1481 		    blob_T  *b1 = tv1->vval.v_blob;
1482 		    blob_T  *b2 = tv2->vval.v_blob;
1483 		    int	i, len = blob_len(b2);
1484 		    for (i = 0; i < len; i++)
1485 			ga_append(&b1->bv_ga, blob_get(b2, i));
1486 		}
1487 		return OK;
1488 
1489 	    case VAR_LIST:
1490 		if (*op != '+' || tv2->v_type != VAR_LIST)
1491 		    break;
1492 		// List += List
1493 		if (tv2->vval.v_list != NULL)
1494 		{
1495 		    if (tv1->vval.v_list == NULL)
1496 		    {
1497 			tv1->vval.v_list = tv2->vval.v_list;
1498 			++tv1->vval.v_list->lv_refcount;
1499 		    }
1500 		    else
1501 			list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
1502 		}
1503 		return OK;
1504 
1505 	    case VAR_NUMBER:
1506 	    case VAR_STRING:
1507 		if (tv2->v_type == VAR_LIST)
1508 		    break;
1509 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
1510 		{
1511 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
1512 		    n = tv_get_number(tv1);
1513 #ifdef FEAT_FLOAT
1514 		    if (tv2->v_type == VAR_FLOAT)
1515 		    {
1516 			float_T f = n;
1517 
1518 			if (*op == '%')
1519 			    break;
1520 			switch (*op)
1521 			{
1522 			    case '+': f += tv2->vval.v_float; break;
1523 			    case '-': f -= tv2->vval.v_float; break;
1524 			    case '*': f *= tv2->vval.v_float; break;
1525 			    case '/': f /= tv2->vval.v_float; break;
1526 			}
1527 			clear_tv(tv1);
1528 			tv1->v_type = VAR_FLOAT;
1529 			tv1->vval.v_float = f;
1530 		    }
1531 		    else
1532 #endif
1533 		    {
1534 			switch (*op)
1535 			{
1536 			    case '+': n += tv_get_number(tv2); break;
1537 			    case '-': n -= tv_get_number(tv2); break;
1538 			    case '*': n *= tv_get_number(tv2); break;
1539 			    case '/': n = num_divide(n, tv_get_number(tv2),
1540 							       &failed); break;
1541 			    case '%': n = num_modulus(n, tv_get_number(tv2),
1542 							       &failed); break;
1543 			}
1544 			clear_tv(tv1);
1545 			tv1->v_type = VAR_NUMBER;
1546 			tv1->vval.v_number = n;
1547 		    }
1548 		}
1549 		else
1550 		{
1551 		    if (tv2->v_type == VAR_FLOAT)
1552 			break;
1553 
1554 		    // str .= str
1555 		    s = tv_get_string(tv1);
1556 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
1557 		    clear_tv(tv1);
1558 		    tv1->v_type = VAR_STRING;
1559 		    tv1->vval.v_string = s;
1560 		}
1561 		return failed ? FAIL : OK;
1562 
1563 	    case VAR_FLOAT:
1564 #ifdef FEAT_FLOAT
1565 		{
1566 		    float_T f;
1567 
1568 		    if (*op == '%' || *op == '.'
1569 				   || (tv2->v_type != VAR_FLOAT
1570 				    && tv2->v_type != VAR_NUMBER
1571 				    && tv2->v_type != VAR_STRING))
1572 			break;
1573 		    if (tv2->v_type == VAR_FLOAT)
1574 			f = tv2->vval.v_float;
1575 		    else
1576 			f = tv_get_number(tv2);
1577 		    switch (*op)
1578 		    {
1579 			case '+': tv1->vval.v_float += f; break;
1580 			case '-': tv1->vval.v_float -= f; break;
1581 			case '*': tv1->vval.v_float *= f; break;
1582 			case '/': tv1->vval.v_float /= f; break;
1583 		    }
1584 		}
1585 #endif
1586 		return OK;
1587 	}
1588     }
1589 
1590     semsg(_(e_letwrong), op);
1591     return FAIL;
1592 }
1593 
1594 /*
1595  * Evaluate the expression used in a ":for var in expr" command.
1596  * "arg" points to "var".
1597  * Set "*errp" to TRUE for an error, FALSE otherwise;
1598  * Return a pointer that holds the info.  Null when there is an error.
1599  */
1600     void *
1601 eval_for_line(
1602     char_u	*arg,
1603     int		*errp,
1604     exarg_T	*eap,
1605     evalarg_T	*evalarg)
1606 {
1607     forinfo_T	*fi;
1608     char_u	*var_list_end;
1609     char_u	*expr;
1610     typval_T	tv;
1611     list_T	*l;
1612     int		skip = !(evalarg->eval_flags & EVAL_EVALUATE);
1613 
1614     *errp = TRUE;	// default: there is an error
1615 
1616     fi = ALLOC_CLEAR_ONE(forinfo_T);
1617     if (fi == NULL)
1618 	return NULL;
1619 
1620     var_list_end = skip_var_list(arg, TRUE, &fi->fi_varcount,
1621 						     &fi->fi_semicolon, FALSE);
1622     if (var_list_end == NULL)
1623 	return fi;
1624 
1625     expr = skipwhite_and_linebreak(var_list_end, evalarg);
1626     if (expr[0] != 'i' || expr[1] != 'n'
1627 				  || !(expr[2] == NUL || VIM_ISWHITE(expr[2])))
1628     {
1629 	if (in_vim9script() && *expr == ':' && expr != var_list_end)
1630 	    semsg(_(e_no_white_space_allowed_before_colon_str), expr);
1631 	else
1632 	    emsg(_(e_missing_in));
1633 	return fi;
1634     }
1635 
1636     if (skip)
1637 	++emsg_skip;
1638     expr = skipwhite_and_linebreak(expr + 2, evalarg);
1639     if (eval0(expr, &tv, eap, evalarg) == OK)
1640     {
1641 	*errp = FALSE;
1642 	if (!skip)
1643 	{
1644 	    if (tv.v_type == VAR_LIST)
1645 	    {
1646 		l = tv.vval.v_list;
1647 		if (l == NULL)
1648 		{
1649 		    // a null list is like an empty list: do nothing
1650 		    clear_tv(&tv);
1651 		}
1652 		else
1653 		{
1654 		    // Need a real list here.
1655 		    CHECK_LIST_MATERIALIZE(l);
1656 
1657 		    // No need to increment the refcount, it's already set for
1658 		    // the list being used in "tv".
1659 		    fi->fi_list = l;
1660 		    list_add_watch(l, &fi->fi_lw);
1661 		    fi->fi_lw.lw_item = l->lv_first;
1662 		}
1663 	    }
1664 	    else if (tv.v_type == VAR_BLOB)
1665 	    {
1666 		fi->fi_bi = 0;
1667 		if (tv.vval.v_blob != NULL)
1668 		{
1669 		    typval_T btv;
1670 
1671 		    // Make a copy, so that the iteration still works when the
1672 		    // blob is changed.
1673 		    blob_copy(tv.vval.v_blob, &btv);
1674 		    fi->fi_blob = btv.vval.v_blob;
1675 		}
1676 		clear_tv(&tv);
1677 	    }
1678 	    else if (tv.v_type == VAR_STRING)
1679 	    {
1680 		fi->fi_byte_idx = 0;
1681 		fi->fi_string = tv.vval.v_string;
1682 		tv.vval.v_string = NULL;
1683 		if (fi->fi_string == NULL)
1684 		    fi->fi_string = vim_strsave((char_u *)"");
1685 	    }
1686 	    else
1687 	    {
1688 		emsg(_(e_string_list_or_blob_required));
1689 		clear_tv(&tv);
1690 	    }
1691 	}
1692     }
1693     if (skip)
1694 	--emsg_skip;
1695     fi->fi_break_count = evalarg->eval_break_count;
1696 
1697     return fi;
1698 }
1699 
1700 /*
1701  * Used when looping over a :for line, skip the "in expr" part.
1702  */
1703     void
1704 skip_for_lines(void *fi_void, evalarg_T *evalarg)
1705 {
1706     forinfo_T	*fi = (forinfo_T *)fi_void;
1707     int		i;
1708 
1709     for (i = 0; i < fi->fi_break_count; ++i)
1710 	eval_next_line(evalarg);
1711 }
1712 
1713 /*
1714  * Use the first item in a ":for" list.  Advance to the next.
1715  * Assign the values to the variable (list).  "arg" points to the first one.
1716  * Return TRUE when a valid item was found, FALSE when at end of list or
1717  * something wrong.
1718  */
1719     int
1720 next_for_item(void *fi_void, char_u *arg)
1721 {
1722     forinfo_T	*fi = (forinfo_T *)fi_void;
1723     int		result;
1724     int		flag = ASSIGN_FOR_LOOP | (in_vim9script()
1725 			 ? (ASSIGN_FINAL
1726 			     // first round: error if variable exists
1727 			     | (fi->fi_bi == 0 ? 0 : ASSIGN_DECL)
1728 			     | ASSIGN_NO_MEMBER_TYPE)
1729 			 : 0);
1730     listitem_T	*item;
1731     int		skip_assign = in_vim9script() && arg[0] == '_'
1732 						      && !eval_isnamec(arg[1]);
1733 
1734     if (fi->fi_blob != NULL)
1735     {
1736 	typval_T	tv;
1737 
1738 	if (fi->fi_bi >= blob_len(fi->fi_blob))
1739 	    return FALSE;
1740 	tv.v_type = VAR_NUMBER;
1741 	tv.v_lock = VAR_FIXED;
1742 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
1743 	++fi->fi_bi;
1744 	if (skip_assign)
1745 	    return TRUE;
1746 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1747 					    fi->fi_varcount, flag, NULL) == OK;
1748     }
1749 
1750     if (fi->fi_string != NULL)
1751     {
1752 	typval_T	tv;
1753 	int		len;
1754 
1755 	len = mb_ptr2len(fi->fi_string + fi->fi_byte_idx);
1756 	if (len == 0)
1757 	    return FALSE;
1758 	tv.v_type = VAR_STRING;
1759 	tv.v_lock = VAR_FIXED;
1760 	tv.vval.v_string = vim_strnsave(fi->fi_string + fi->fi_byte_idx, len);
1761 	fi->fi_byte_idx += len;
1762 	++fi->fi_bi;
1763 	if (skip_assign)
1764 	    result = TRUE;
1765 	else
1766 	    result = ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1767 					    fi->fi_varcount, flag, NULL) == OK;
1768 	vim_free(tv.vval.v_string);
1769 	return result;
1770     }
1771 
1772     item = fi->fi_lw.lw_item;
1773     if (item == NULL)
1774 	result = FALSE;
1775     else
1776     {
1777 	fi->fi_lw.lw_item = item->li_next;
1778 	++fi->fi_bi;
1779 	if (skip_assign)
1780 	    result = TRUE;
1781 	else
1782 	    result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
1783 					   fi->fi_varcount, flag, NULL) == OK);
1784     }
1785     return result;
1786 }
1787 
1788 /*
1789  * Free the structure used to store info used by ":for".
1790  */
1791     void
1792 free_for_info(void *fi_void)
1793 {
1794     forinfo_T    *fi = (forinfo_T *)fi_void;
1795 
1796     if (fi == NULL)
1797 	return;
1798     if (fi->fi_list != NULL)
1799     {
1800 	list_rem_watch(fi->fi_list, &fi->fi_lw);
1801 	list_unref(fi->fi_list);
1802     }
1803     else if (fi->fi_blob != NULL)
1804 	blob_unref(fi->fi_blob);
1805     else
1806 	vim_free(fi->fi_string);
1807     vim_free(fi);
1808 }
1809 
1810     void
1811 set_context_for_expression(
1812     expand_T	*xp,
1813     char_u	*arg,
1814     cmdidx_T	cmdidx)
1815 {
1816     int		has_expr = cmdidx != CMD_let && cmdidx != CMD_var;
1817     int		c;
1818     char_u	*p;
1819 
1820     if (cmdidx == CMD_let || cmdidx == CMD_var
1821 				 || cmdidx == CMD_const || cmdidx == CMD_final)
1822     {
1823 	xp->xp_context = EXPAND_USER_VARS;
1824 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
1825 	{
1826 	    // ":let var1 var2 ...": find last space.
1827 	    for (p = arg + STRLEN(arg); p >= arg; )
1828 	    {
1829 		xp->xp_pattern = p;
1830 		MB_PTR_BACK(arg, p);
1831 		if (VIM_ISWHITE(*p))
1832 		    break;
1833 	    }
1834 	    return;
1835 	}
1836     }
1837     else
1838 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
1839 							  : EXPAND_EXPRESSION;
1840     while ((xp->xp_pattern = vim_strpbrk(arg,
1841 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
1842     {
1843 	c = *xp->xp_pattern;
1844 	if (c == '&')
1845 	{
1846 	    c = xp->xp_pattern[1];
1847 	    if (c == '&')
1848 	    {
1849 		++xp->xp_pattern;
1850 		xp->xp_context = has_expr ? EXPAND_EXPRESSION : EXPAND_NOTHING;
1851 	    }
1852 	    else if (c != ' ')
1853 	    {
1854 		xp->xp_context = EXPAND_SETTINGS;
1855 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
1856 		    xp->xp_pattern += 2;
1857 
1858 	    }
1859 	}
1860 	else if (c == '$')
1861 	{
1862 	    // environment variable
1863 	    xp->xp_context = EXPAND_ENV_VARS;
1864 	}
1865 	else if (c == '=')
1866 	{
1867 	    has_expr = TRUE;
1868 	    xp->xp_context = EXPAND_EXPRESSION;
1869 	}
1870 	else if (c == '#'
1871 		&& xp->xp_context == EXPAND_EXPRESSION)
1872 	{
1873 	    // Autoload function/variable contains '#'.
1874 	    break;
1875 	}
1876 	else if ((c == '<' || c == '#')
1877 		&& xp->xp_context == EXPAND_FUNCTIONS
1878 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
1879 	{
1880 	    // Function name can start with "<SNR>" and contain '#'.
1881 	    break;
1882 	}
1883 	else if (has_expr)
1884 	{
1885 	    if (c == '"')	    // string
1886 	    {
1887 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
1888 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
1889 			++xp->xp_pattern;
1890 		xp->xp_context = EXPAND_NOTHING;
1891 	    }
1892 	    else if (c == '\'')	    // literal string
1893 	    {
1894 		// Trick: '' is like stopping and starting a literal string.
1895 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
1896 		    /* skip */ ;
1897 		xp->xp_context = EXPAND_NOTHING;
1898 	    }
1899 	    else if (c == '|')
1900 	    {
1901 		if (xp->xp_pattern[1] == '|')
1902 		{
1903 		    ++xp->xp_pattern;
1904 		    xp->xp_context = EXPAND_EXPRESSION;
1905 		}
1906 		else
1907 		    xp->xp_context = EXPAND_COMMANDS;
1908 	    }
1909 	    else
1910 		xp->xp_context = EXPAND_EXPRESSION;
1911 	}
1912 	else
1913 	    // Doesn't look like something valid, expand as an expression
1914 	    // anyway.
1915 	    xp->xp_context = EXPAND_EXPRESSION;
1916 	arg = xp->xp_pattern;
1917 	if (*arg != NUL)
1918 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
1919 		/* skip */ ;
1920     }
1921 
1922     // ":exe one two" completes "two"
1923     if ((cmdidx == CMD_execute
1924 		|| cmdidx == CMD_echo
1925 		|| cmdidx == CMD_echon
1926 		|| cmdidx == CMD_echomsg)
1927 	    && xp->xp_context == EXPAND_EXPRESSION)
1928     {
1929 	for (;;)
1930 	{
1931 	    char_u *n = skiptowhite(arg);
1932 
1933 	    if (n == arg || IS_WHITE_OR_NUL(*skipwhite(n)))
1934 		break;
1935 	    arg = skipwhite(n);
1936 	}
1937     }
1938 
1939     xp->xp_pattern = arg;
1940 }
1941 
1942 /*
1943  * Return TRUE if "pat" matches "text".
1944  * Does not use 'cpo' and always uses 'magic'.
1945  */
1946     int
1947 pattern_match(char_u *pat, char_u *text, int ic)
1948 {
1949     int		matches = FALSE;
1950     char_u	*save_cpo;
1951     regmatch_T	regmatch;
1952 
1953     // avoid 'l' flag in 'cpoptions'
1954     save_cpo = p_cpo;
1955     p_cpo = empty_option;
1956     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1957     if (regmatch.regprog != NULL)
1958     {
1959 	regmatch.rm_ic = ic;
1960 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
1961 	vim_regfree(regmatch.regprog);
1962     }
1963     p_cpo = save_cpo;
1964     return matches;
1965 }
1966 
1967 /*
1968  * Handle a name followed by "(".  Both for just "name(arg)" and for
1969  * "expr->name(arg)".
1970  * Returns OK or FAIL.
1971  */
1972     static int
1973 eval_func(
1974 	char_u	    **arg,	// points to "(", will be advanced
1975 	evalarg_T   *evalarg,
1976 	char_u	    *name,
1977 	int	    name_len,
1978 	typval_T    *rettv,
1979 	int	    flags,
1980 	typval_T    *basetv)	// "expr" for "expr->name(arg)"
1981 {
1982     int		evaluate = flags & EVAL_EVALUATE;
1983     char_u	*s = name;
1984     int		len = name_len;
1985     partial_T	*partial;
1986     int		ret = OK;
1987     type_T	*type = NULL;
1988 
1989     if (!evaluate)
1990 	check_vars(s, len);
1991 
1992     // If "s" is the name of a variable of type VAR_FUNC
1993     // use its contents.
1994     s = deref_func_name(s, &len, &partial,
1995 				    in_vim9script() ? &type : NULL, !evaluate);
1996 
1997     // Need to make a copy, in case evaluating the arguments makes
1998     // the name invalid.
1999     s = vim_strsave(s);
2000     if (s == NULL || (flags & EVAL_CONSTANT))
2001 	ret = FAIL;
2002     else
2003     {
2004 	funcexe_T funcexe;
2005 
2006 	// Invoke the function.
2007 	CLEAR_FIELD(funcexe);
2008 	funcexe.firstline = curwin->w_cursor.lnum;
2009 	funcexe.lastline = curwin->w_cursor.lnum;
2010 	funcexe.evaluate = evaluate;
2011 	funcexe.partial = partial;
2012 	funcexe.basetv = basetv;
2013 	funcexe.check_type = type;
2014 	ret = get_func_tv(s, len, rettv, arg, evalarg, &funcexe);
2015     }
2016     vim_free(s);
2017 
2018     // If evaluate is FALSE rettv->v_type was not set in
2019     // get_func_tv, but it's needed in handle_subscript() to parse
2020     // what follows. So set it here.
2021     if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
2022     {
2023 	rettv->vval.v_string = NULL;
2024 	rettv->v_type = VAR_FUNC;
2025     }
2026 
2027     // Stop the expression evaluation when immediately
2028     // aborting on error, or when an interrupt occurred or
2029     // an exception was thrown but not caught.
2030     if (evaluate && aborting())
2031     {
2032 	if (ret == OK)
2033 	    clear_tv(rettv);
2034 	ret = FAIL;
2035     }
2036     return ret;
2037 }
2038 
2039 /*
2040  * Get the next line source line without advancing.  But do skip over comment
2041  * lines.
2042  * Only called for Vim9 script.
2043  */
2044     static char_u *
2045 getline_peek_skip_comments(evalarg_T *evalarg)
2046 {
2047     for (;;)
2048     {
2049 	char_u *next = getline_peek(evalarg->eval_getline,
2050 							 evalarg->eval_cookie);
2051 	char_u *p;
2052 
2053 	if (next == NULL)
2054 	    break;
2055 	p = skipwhite(next);
2056 	if (*p != NUL && !vim9_comment_start(p))
2057 	    return next;
2058 	(void)eval_next_line(evalarg);
2059     }
2060     return NULL;
2061 }
2062 
2063 /*
2064  * If inside Vim9 script, "arg" points to the end of a line (ignoring a #
2065  * comment) and there is a next line, return the next line (skipping blanks)
2066  * and set "getnext".
2067  * Otherwise return the next non-white at or after "arg" and set "getnext" to
2068  * FALSE.
2069  * "arg" must point somewhere inside a line, not at the start.
2070  */
2071     static char_u *
2072 eval_next_non_blank(char_u *arg, evalarg_T *evalarg, int *getnext)
2073 {
2074     char_u *p = skipwhite(arg);
2075 
2076     *getnext = FALSE;
2077     if (in_vim9script()
2078 	    && evalarg != NULL
2079 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL)
2080 	    && (*p == NUL || (vim9_comment_start(p) && VIM_ISWHITE(p[-1]))))
2081     {
2082 	char_u *next;
2083 
2084 	if (evalarg->eval_cookie != NULL)
2085 	    next = getline_peek_skip_comments(evalarg);
2086 	else
2087 	    next = peek_next_line_from_context(evalarg->eval_cctx);
2088 
2089 	if (next != NULL)
2090 	{
2091 	    *getnext = TRUE;
2092 	    return skipwhite(next);
2093 	}
2094     }
2095     return p;
2096 }
2097 
2098 /*
2099  * To be called after eval_next_non_blank() sets "getnext" to TRUE.
2100  * Only called for Vim9 script.
2101  */
2102     static char_u *
2103 eval_next_line(evalarg_T *evalarg)
2104 {
2105     garray_T	*gap = &evalarg->eval_ga;
2106     char_u	*line;
2107 
2108     if (evalarg->eval_cookie != NULL)
2109 	line = evalarg->eval_getline(0, evalarg->eval_cookie, 0,
2110 							   GETLINE_CONCAT_ALL);
2111     else
2112 	line = next_line_from_context(evalarg->eval_cctx, TRUE);
2113     ++evalarg->eval_break_count;
2114     if (gap->ga_itemsize > 0 && ga_grow(gap, 1) == OK)
2115     {
2116 	char_u *p = skipwhite(line);
2117 
2118 	// Going to concatenate the lines after parsing.  For an empty or
2119 	// comment line use an empty string.
2120 	if (*p == NUL || vim9_comment_start(p))
2121 	{
2122 	    vim_free(line);
2123 	    line = vim_strsave((char_u *)"");
2124 	}
2125 
2126 	((char_u **)gap->ga_data)[gap->ga_len] = line;
2127 	++gap->ga_len;
2128     }
2129     else if (evalarg->eval_cookie != NULL)
2130     {
2131 	vim_free(evalarg->eval_tofree);
2132 	evalarg->eval_tofree = line;
2133     }
2134 
2135     // Advanced to the next line, "arg" no longer points into the previous
2136     // line.
2137     VIM_CLEAR(evalarg->eval_tofree_cmdline);
2138 
2139     return skipwhite(line);
2140 }
2141 
2142 /*
2143  * Call eval_next_non_blank() and get the next line if needed.
2144  */
2145     char_u *
2146 skipwhite_and_linebreak(char_u *arg, evalarg_T *evalarg)
2147 {
2148     int	    getnext;
2149     char_u  *p = skipwhite(arg);
2150 
2151     if (evalarg == NULL)
2152 	return skipwhite(arg);
2153     eval_next_non_blank(p, evalarg, &getnext);
2154     if (getnext)
2155 	return eval_next_line(evalarg);
2156     return p;
2157 }
2158 
2159 /*
2160  * After using "evalarg" filled from "eap": free the memory.
2161  */
2162     void
2163 clear_evalarg(evalarg_T *evalarg, exarg_T *eap)
2164 {
2165     if (evalarg != NULL)
2166     {
2167 	if (evalarg->eval_tofree != NULL)
2168 	{
2169 	    if (eap != NULL)
2170 	    {
2171 		// We may need to keep the original command line, e.g. for
2172 		// ":let" it has the variable names.  But we may also need the
2173 		// new one, "nextcmd" points into it.  Keep both.
2174 		vim_free(eap->cmdline_tofree);
2175 		eap->cmdline_tofree = *eap->cmdlinep;
2176 		*eap->cmdlinep = evalarg->eval_tofree;
2177 	    }
2178 	    else
2179 		vim_free(evalarg->eval_tofree);
2180 	    evalarg->eval_tofree = NULL;
2181 	}
2182 
2183 	VIM_CLEAR(evalarg->eval_tofree_cmdline);
2184 	VIM_CLEAR(evalarg->eval_tofree_lambda);
2185     }
2186 }
2187 
2188 /*
2189  * The "evaluate" argument: When FALSE, the argument is only parsed but not
2190  * executed.  The function may return OK, but the rettv will be of type
2191  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
2192  */
2193 
2194 /*
2195  * Handle zero level expression.
2196  * This calls eval1() and handles error message and nextcmd.
2197  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
2198  * Note: "rettv.v_lock" is not set.
2199  * "evalarg" can be NULL, EVALARG_EVALUATE or a pointer.
2200  * Return OK or FAIL.
2201  */
2202     int
2203 eval0(
2204     char_u	*arg,
2205     typval_T	*rettv,
2206     exarg_T	*eap,
2207     evalarg_T	*evalarg)
2208 {
2209     int		ret;
2210     char_u	*p;
2211     int		did_emsg_before = did_emsg;
2212     int		called_emsg_before = called_emsg;
2213     int		flags = evalarg == NULL ? 0 : evalarg->eval_flags;
2214     int		end_error = FALSE;
2215 
2216     p = skipwhite(arg);
2217     ret = eval1(&p, rettv, evalarg);
2218     p = skipwhite(p);
2219 
2220     if (ret != FAIL)
2221 	end_error = !ends_excmd2(arg, p);
2222     if (ret == FAIL || end_error)
2223     {
2224 	if (ret != FAIL)
2225 	    clear_tv(rettv);
2226 	/*
2227 	 * Report the invalid expression unless the expression evaluation has
2228 	 * been cancelled due to an aborting error, an interrupt, or an
2229 	 * exception, or we already gave a more specific error.
2230 	 * Also check called_emsg for when using assert_fails().
2231 	 */
2232 	if (!aborting()
2233 		&& did_emsg == did_emsg_before
2234 		&& called_emsg == called_emsg_before
2235 		&& (flags & EVAL_CONSTANT) == 0
2236 		&& (!in_vim9script() || !vim9_bad_comment(p)))
2237 	{
2238 	    if (end_error)
2239 		semsg(_(e_trailing_arg), p);
2240 	    else
2241 		semsg(_(e_invalid_expression_str), arg);
2242 	}
2243 
2244 	// Some of the expression may not have been consumed.  Do not check for
2245 	// a next command to avoid more errors, unless "|" is following, which
2246 	// could only be a command separator.
2247 	if (eap != NULL && skipwhite(p)[0] == '|' && skipwhite(p)[1] != '|')
2248 	    eap->nextcmd = check_nextcmd(p);
2249 	return FAIL;
2250     }
2251 
2252     if (eap != NULL)
2253 	set_nextcmd(eap, p);
2254 
2255     return ret;
2256 }
2257 
2258 /*
2259  * Handle top level expression:
2260  *	expr2 ? expr1 : expr1
2261  *	expr2 ?? expr1
2262  *
2263  * "arg" must point to the first non-white of the expression.
2264  * "arg" is advanced to just after the recognized expression.
2265  *
2266  * Note: "rettv.v_lock" is not set.
2267  *
2268  * Return OK or FAIL.
2269  */
2270     int
2271 eval1(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2272 {
2273     char_u  *p;
2274     int	    getnext;
2275 
2276     CLEAR_POINTER(rettv);
2277 
2278     /*
2279      * Get the first variable.
2280      */
2281     if (eval2(arg, rettv, evalarg) == FAIL)
2282 	return FAIL;
2283 
2284     p = eval_next_non_blank(*arg, evalarg, &getnext);
2285     if (*p == '?')
2286     {
2287 	int		op_falsy = p[1] == '?';
2288 	int		result;
2289 	typval_T	var2;
2290 	evalarg_T	*evalarg_used = evalarg;
2291 	evalarg_T	local_evalarg;
2292 	int		orig_flags;
2293 	int		evaluate;
2294 	int		vim9script = in_vim9script();
2295 
2296 	if (evalarg == NULL)
2297 	{
2298 	    CLEAR_FIELD(local_evalarg);
2299 	    evalarg_used = &local_evalarg;
2300 	}
2301 	orig_flags = evalarg_used->eval_flags;
2302 	evaluate = evalarg_used->eval_flags & EVAL_EVALUATE;
2303 
2304 	if (getnext)
2305 	    *arg = eval_next_line(evalarg_used);
2306 	else
2307 	{
2308 	    if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2309 	    {
2310 		error_white_both(p, op_falsy ? 2 : 1);
2311 		clear_tv(rettv);
2312 		return FAIL;
2313 	    }
2314 	    *arg = p;
2315 	}
2316 
2317 	result = FALSE;
2318 	if (evaluate)
2319 	{
2320 	    int		error = FALSE;
2321 
2322 	    if (op_falsy)
2323 		result = tv2bool(rettv);
2324 	    else if (vim9script)
2325 		result = tv_get_bool_chk(rettv, &error);
2326 	    else if (tv_get_number_chk(rettv, &error) != 0)
2327 		result = TRUE;
2328 	    if (error || !op_falsy || !result)
2329 		clear_tv(rettv);
2330 	    if (error)
2331 		return FAIL;
2332 	}
2333 
2334 	/*
2335 	 * Get the second variable.  Recursive!
2336 	 */
2337 	if (op_falsy)
2338 	    ++*arg;
2339 	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[1]))
2340 	{
2341 	    error_white_both(*arg - (op_falsy ? 1 : 0), op_falsy ? 2 : 1);
2342 	    clear_tv(rettv);
2343 	    return FAIL;
2344 	}
2345 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2346 	evalarg_used->eval_flags = (op_falsy ? !result : result)
2347 				    ? orig_flags : orig_flags & ~EVAL_EVALUATE;
2348 	if (eval1(arg, &var2, evalarg_used) == FAIL)
2349 	{
2350 	    evalarg_used->eval_flags = orig_flags;
2351 	    return FAIL;
2352 	}
2353 	if (!op_falsy || !result)
2354 	    *rettv = var2;
2355 
2356 	if (!op_falsy)
2357 	{
2358 	    /*
2359 	     * Check for the ":".
2360 	     */
2361 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2362 	    if (*p != ':')
2363 	    {
2364 		emsg(_(e_missing_colon));
2365 		if (evaluate && result)
2366 		    clear_tv(rettv);
2367 		evalarg_used->eval_flags = orig_flags;
2368 		return FAIL;
2369 	    }
2370 	    if (getnext)
2371 		*arg = eval_next_line(evalarg_used);
2372 	    else
2373 	    {
2374 		if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2375 		{
2376 		    error_white_both(p, 1);
2377 		    clear_tv(rettv);
2378 		    evalarg_used->eval_flags = orig_flags;
2379 		    return FAIL;
2380 		}
2381 		*arg = p;
2382 	    }
2383 
2384 	    /*
2385 	     * Get the third variable.  Recursive!
2386 	     */
2387 	    if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[1]))
2388 	    {
2389 		error_white_both(*arg, 1);
2390 		clear_tv(rettv);
2391 		evalarg_used->eval_flags = orig_flags;
2392 		return FAIL;
2393 	    }
2394 	    *arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2395 	    evalarg_used->eval_flags = !result ? orig_flags
2396 						 : orig_flags & ~EVAL_EVALUATE;
2397 	    if (eval1(arg, &var2, evalarg_used) == FAIL)
2398 	    {
2399 		if (evaluate && result)
2400 		    clear_tv(rettv);
2401 		evalarg_used->eval_flags = orig_flags;
2402 		return FAIL;
2403 	    }
2404 	    if (evaluate && !result)
2405 		*rettv = var2;
2406 	}
2407 
2408 	if (evalarg == NULL)
2409 	    clear_evalarg(&local_evalarg, NULL);
2410 	else
2411 	    evalarg->eval_flags = orig_flags;
2412     }
2413 
2414     return OK;
2415 }
2416 
2417 /*
2418  * Handle first level expression:
2419  *	expr2 || expr2 || expr2	    logical OR
2420  *
2421  * "arg" must point to the first non-white of the expression.
2422  * "arg" is advanced to just after the recognized expression.
2423  *
2424  * Return OK or FAIL.
2425  */
2426     static int
2427 eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2428 {
2429     char_u	*p;
2430     int		getnext;
2431 
2432     /*
2433      * Get the first variable.
2434      */
2435     if (eval3(arg, rettv, evalarg) == FAIL)
2436 	return FAIL;
2437 
2438     /*
2439      * Handle the  "||" operator.
2440      */
2441     p = eval_next_non_blank(*arg, evalarg, &getnext);
2442     if (p[0] == '|' && p[1] == '|')
2443     {
2444 	evalarg_T   *evalarg_used = evalarg;
2445 	evalarg_T   local_evalarg;
2446 	int	    evaluate;
2447 	int	    orig_flags;
2448 	long	    result = FALSE;
2449 	typval_T    var2;
2450 	int	    error = FALSE;
2451 	int	    vim9script = in_vim9script();
2452 
2453 	if (evalarg == NULL)
2454 	{
2455 	    CLEAR_FIELD(local_evalarg);
2456 	    evalarg_used = &local_evalarg;
2457 	}
2458 	orig_flags = evalarg_used->eval_flags;
2459 	evaluate = orig_flags & EVAL_EVALUATE;
2460 	if (evaluate)
2461 	{
2462 	    if (vim9script)
2463 		result = tv_get_bool_chk(rettv, &error);
2464 	    else if (tv_get_number_chk(rettv, &error) != 0)
2465 		result = TRUE;
2466 	    clear_tv(rettv);
2467 	    if (error)
2468 		return FAIL;
2469 	}
2470 
2471 	/*
2472 	 * Repeat until there is no following "||".
2473 	 */
2474 	while (p[0] == '|' && p[1] == '|')
2475 	{
2476 	    if (getnext)
2477 		*arg = eval_next_line(evalarg_used);
2478 	    else
2479 	    {
2480 		if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2481 		{
2482 		    error_white_both(p, 2);
2483 		    clear_tv(rettv);
2484 		    return FAIL;
2485 		}
2486 		*arg = p;
2487 	    }
2488 
2489 	    /*
2490 	     * Get the second variable.
2491 	     */
2492 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2493 	    {
2494 		error_white_both(*arg, 2);
2495 		clear_tv(rettv);
2496 		return FAIL;
2497 	    }
2498 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2499 	    evalarg_used->eval_flags = !result ? orig_flags
2500 						 : orig_flags & ~EVAL_EVALUATE;
2501 	    if (eval3(arg, &var2, evalarg_used) == FAIL)
2502 		return FAIL;
2503 
2504 	    /*
2505 	     * Compute the result.
2506 	     */
2507 	    if (evaluate && !result)
2508 	    {
2509 		if (vim9script)
2510 		    result = tv_get_bool_chk(&var2, &error);
2511 		else if (tv_get_number_chk(&var2, &error) != 0)
2512 		    result = TRUE;
2513 		clear_tv(&var2);
2514 		if (error)
2515 		    return FAIL;
2516 	    }
2517 	    if (evaluate)
2518 	    {
2519 		if (vim9script)
2520 		{
2521 		    rettv->v_type = VAR_BOOL;
2522 		    rettv->vval.v_number = result ? VVAL_TRUE : VVAL_FALSE;
2523 		}
2524 		else
2525 		{
2526 		    rettv->v_type = VAR_NUMBER;
2527 		    rettv->vval.v_number = result;
2528 		}
2529 	    }
2530 
2531 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2532 	}
2533 
2534 	if (evalarg == NULL)
2535 	    clear_evalarg(&local_evalarg, NULL);
2536 	else
2537 	    evalarg->eval_flags = orig_flags;
2538     }
2539 
2540     return OK;
2541 }
2542 
2543 /*
2544  * Handle second level expression:
2545  *	expr3 && expr3 && expr3	    logical AND
2546  *
2547  * "arg" must point to the first non-white of the expression.
2548  * "arg" is advanced to just after the recognized expression.
2549  *
2550  * Return OK or FAIL.
2551  */
2552     static int
2553 eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2554 {
2555     char_u	*p;
2556     int		getnext;
2557 
2558     /*
2559      * Get the first variable.
2560      */
2561     if (eval4(arg, rettv, evalarg) == FAIL)
2562 	return FAIL;
2563 
2564     /*
2565      * Handle the "&&" operator.
2566      */
2567     p = eval_next_non_blank(*arg, evalarg, &getnext);
2568     if (p[0] == '&' && p[1] == '&')
2569     {
2570 	evalarg_T   *evalarg_used = evalarg;
2571 	evalarg_T   local_evalarg;
2572 	int	    orig_flags;
2573 	int	    evaluate;
2574 	long	    result = TRUE;
2575 	typval_T    var2;
2576 	int	    error = FALSE;
2577 	int	    vim9script = in_vim9script();
2578 
2579 	if (evalarg == NULL)
2580 	{
2581 	    CLEAR_FIELD(local_evalarg);
2582 	    evalarg_used = &local_evalarg;
2583 	}
2584 	orig_flags = evalarg_used->eval_flags;
2585 	evaluate = orig_flags & EVAL_EVALUATE;
2586 	if (evaluate)
2587 	{
2588 	    if (vim9script)
2589 		result = tv_get_bool_chk(rettv, &error);
2590 	    else if (tv_get_number_chk(rettv, &error) == 0)
2591 		result = FALSE;
2592 	    clear_tv(rettv);
2593 	    if (error)
2594 		return FAIL;
2595 	}
2596 
2597 	/*
2598 	 * Repeat until there is no following "&&".
2599 	 */
2600 	while (p[0] == '&' && p[1] == '&')
2601 	{
2602 	    if (getnext)
2603 		*arg = eval_next_line(evalarg_used);
2604 	    else
2605 	    {
2606 		if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2607 		{
2608 		    error_white_both(p, 2);
2609 		    clear_tv(rettv);
2610 		    return FAIL;
2611 		}
2612 		*arg = p;
2613 	    }
2614 
2615 	    /*
2616 	     * Get the second variable.
2617 	     */
2618 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2619 	    {
2620 		error_white_both(*arg, 2);
2621 		clear_tv(rettv);
2622 		return FAIL;
2623 	    }
2624 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2625 	    evalarg_used->eval_flags = result ? orig_flags
2626 						 : orig_flags & ~EVAL_EVALUATE;
2627 	    CLEAR_FIELD(var2);
2628 	    if (eval4(arg, &var2, evalarg_used) == FAIL)
2629 		return FAIL;
2630 
2631 	    /*
2632 	     * Compute the result.
2633 	     */
2634 	    if (evaluate && result)
2635 	    {
2636 		if (vim9script)
2637 		    result = tv_get_bool_chk(&var2, &error);
2638 		else if (tv_get_number_chk(&var2, &error) == 0)
2639 		    result = FALSE;
2640 		clear_tv(&var2);
2641 		if (error)
2642 		    return FAIL;
2643 	    }
2644 	    if (evaluate)
2645 	    {
2646 		if (vim9script)
2647 		{
2648 		    rettv->v_type = VAR_BOOL;
2649 		    rettv->vval.v_number = result ? VVAL_TRUE : VVAL_FALSE;
2650 		}
2651 		else
2652 		{
2653 		    rettv->v_type = VAR_NUMBER;
2654 		    rettv->vval.v_number = result;
2655 		}
2656 	    }
2657 
2658 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2659 	}
2660 
2661 	if (evalarg == NULL)
2662 	    clear_evalarg(&local_evalarg, NULL);
2663 	else
2664 	    evalarg->eval_flags = orig_flags;
2665     }
2666 
2667     return OK;
2668 }
2669 
2670 /*
2671  * Handle third level expression:
2672  *	var1 == var2
2673  *	var1 =~ var2
2674  *	var1 != var2
2675  *	var1 !~ var2
2676  *	var1 > var2
2677  *	var1 >= var2
2678  *	var1 < var2
2679  *	var1 <= var2
2680  *	var1 is var2
2681  *	var1 isnot var2
2682  *
2683  * "arg" must point to the first non-white of the expression.
2684  * "arg" is advanced to just after the recognized expression.
2685  *
2686  * Return OK or FAIL.
2687  */
2688     static int
2689 eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2690 {
2691     char_u	*p;
2692     int		getnext;
2693     exprtype_T	type = EXPR_UNKNOWN;
2694     int		len = 2;
2695     int		type_is = FALSE;
2696 
2697     /*
2698      * Get the first variable.
2699      */
2700     if (eval5(arg, rettv, evalarg) == FAIL)
2701 	return FAIL;
2702 
2703     p = eval_next_non_blank(*arg, evalarg, &getnext);
2704     type = get_compare_type(p, &len, &type_is);
2705 
2706     /*
2707      * If there is a comparative operator, use it.
2708      */
2709     if (type != EXPR_UNKNOWN)
2710     {
2711 	typval_T    var2;
2712 	int	    ic;
2713 	int	    vim9script = in_vim9script();
2714 	int	    evaluate = evalarg == NULL
2715 				   ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2716 
2717 	if (getnext)
2718 	{
2719 	    *arg = eval_next_line(evalarg);
2720 	    p = *arg;
2721 	}
2722 	else if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2723 	{
2724 	    error_white_both(*arg, len);
2725 	    clear_tv(rettv);
2726 	    return FAIL;
2727 	}
2728 
2729 	if (vim9script && type_is && (p[len] == '?' || p[len] == '#'))
2730 	{
2731 	    semsg(_(e_invalid_expression_str), p);
2732 	    clear_tv(rettv);
2733 	    return FAIL;
2734 	}
2735 
2736 	// extra question mark appended: ignore case
2737 	if (p[len] == '?')
2738 	{
2739 	    ic = TRUE;
2740 	    ++len;
2741 	}
2742 	// extra '#' appended: match case
2743 	else if (p[len] == '#')
2744 	{
2745 	    ic = FALSE;
2746 	    ++len;
2747 	}
2748 	// nothing appended: use 'ignorecase' if not in Vim script
2749 	else
2750 	    ic = vim9script ? FALSE : p_ic;
2751 
2752 	/*
2753 	 * Get the second variable.
2754 	 */
2755 	if (evaluate && vim9script && !IS_WHITE_OR_NUL(p[len]))
2756 	{
2757 	    error_white_both(p, len);
2758 	    clear_tv(rettv);
2759 	    return FAIL;
2760 	}
2761 	*arg = skipwhite_and_linebreak(p + len, evalarg);
2762 	if (eval5(arg, &var2, evalarg) == FAIL)
2763 	{
2764 	    clear_tv(rettv);
2765 	    return FAIL;
2766 	}
2767 	if (evaluate)
2768 	{
2769 	    int ret;
2770 
2771 	    if (vim9script && check_compare_types(type, rettv, &var2) == FAIL)
2772 	    {
2773 		ret = FAIL;
2774 		clear_tv(rettv);
2775 	    }
2776 	    else
2777 		ret = typval_compare(rettv, &var2, type, ic);
2778 	    clear_tv(&var2);
2779 	    return ret;
2780 	}
2781     }
2782 
2783     return OK;
2784 }
2785 
2786 /*
2787  * Make a copy of blob "tv1" and append blob "tv2".
2788  */
2789     void
2790 eval_addblob(typval_T *tv1, typval_T *tv2)
2791 {
2792     blob_T  *b1 = tv1->vval.v_blob;
2793     blob_T  *b2 = tv2->vval.v_blob;
2794     blob_T  *b = blob_alloc();
2795     int	    i;
2796 
2797     if (b != NULL)
2798     {
2799 	for (i = 0; i < blob_len(b1); i++)
2800 	    ga_append(&b->bv_ga, blob_get(b1, i));
2801 	for (i = 0; i < blob_len(b2); i++)
2802 	    ga_append(&b->bv_ga, blob_get(b2, i));
2803 
2804 	clear_tv(tv1);
2805 	rettv_blob_set(tv1, b);
2806     }
2807 }
2808 
2809 /*
2810  * Make a copy of list "tv1" and append list "tv2".
2811  */
2812     int
2813 eval_addlist(typval_T *tv1, typval_T *tv2)
2814 {
2815     typval_T var3;
2816 
2817     // concatenate Lists
2818     if (list_concat(tv1->vval.v_list, tv2->vval.v_list, &var3) == FAIL)
2819     {
2820 	clear_tv(tv1);
2821 	clear_tv(tv2);
2822 	return FAIL;
2823     }
2824     clear_tv(tv1);
2825     *tv1 = var3;
2826     return OK;
2827 }
2828 
2829 /*
2830  * Handle fourth level expression:
2831  *	+	number addition
2832  *	-	number subtraction
2833  *	.	string concatenation (if script version is 1)
2834  *	..	string concatenation
2835  *
2836  * "arg" must point to the first non-white of the expression.
2837  * "arg" is advanced to just after the recognized expression.
2838  *
2839  * Return OK or FAIL.
2840  */
2841     static int
2842 eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2843 {
2844     /*
2845      * Get the first variable.
2846      */
2847     if (eval6(arg, rettv, evalarg, FALSE) == FAIL)
2848 	return FAIL;
2849 
2850     /*
2851      * Repeat computing, until no '+', '-' or '.' is following.
2852      */
2853     for (;;)
2854     {
2855 	int	    evaluate;
2856 	int	    getnext;
2857 	char_u	    *p;
2858 	int	    op;
2859 	int	    oplen;
2860 	int	    concat;
2861 	typval_T    var2;
2862 	int	    vim9script = in_vim9script();
2863 
2864 	// "." is only string concatenation when scriptversion is 1
2865 	// "+=", "-=" and "..=" are assignments
2866 	// "++" and "--" on the next line are a separate command.
2867 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2868 	op = *p;
2869 	concat = op == '.' && (*(p + 1) == '.' || in_old_script(2));
2870 	if ((op != '+' && op != '-' && !concat) || p[1] == '='
2871 					       || (p[1] == '.' && p[2] == '='))
2872 	    break;
2873 	if (getnext && (op == '+' || op == '-') && p[0] == p[1])
2874 	    break;
2875 
2876 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2877 	oplen = (concat && p[1] == '.') ? 2 : 1;
2878 	if (getnext)
2879 	    *arg = eval_next_line(evalarg);
2880 	else
2881 	{
2882 	    if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2883 	    {
2884 		error_white_both(*arg, oplen);
2885 		clear_tv(rettv);
2886 		return FAIL;
2887 	    }
2888 	    *arg = p;
2889 	}
2890 	if ((op != '+' || (rettv->v_type != VAR_LIST
2891 						 && rettv->v_type != VAR_BLOB))
2892 #ifdef FEAT_FLOAT
2893 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2894 #endif
2895 		&& evaluate)
2896 	{
2897 	    int		error = FALSE;
2898 
2899 	    // For "list + ...", an illegal use of the first operand as
2900 	    // a number cannot be determined before evaluating the 2nd
2901 	    // operand: if this is also a list, all is ok.
2902 	    // For "something . ...", "something - ..." or "non-list + ...",
2903 	    // we know that the first operand needs to be a string or number
2904 	    // without evaluating the 2nd operand.  So check before to avoid
2905 	    // side effects after an error.
2906 	    if (op != '.')
2907 		tv_get_number_chk(rettv, &error);
2908 	    if ((op == '.' && tv_get_string_chk(rettv) == NULL) || error)
2909 	    {
2910 		clear_tv(rettv);
2911 		return FAIL;
2912 	    }
2913 	}
2914 
2915 	/*
2916 	 * Get the second variable.
2917 	 */
2918 	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[oplen]))
2919 	{
2920 	    error_white_both(*arg, oplen);
2921 	    clear_tv(rettv);
2922 	    return FAIL;
2923 	}
2924 	*arg = skipwhite_and_linebreak(*arg + oplen, evalarg);
2925 	if (eval6(arg, &var2, evalarg, !vim9script && op == '.') == FAIL)
2926 	{
2927 	    clear_tv(rettv);
2928 	    return FAIL;
2929 	}
2930 
2931 	if (evaluate)
2932 	{
2933 	    /*
2934 	     * Compute the result.
2935 	     */
2936 	    if (op == '.')
2937 	    {
2938 		char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
2939 		char_u	*s1 = tv_get_string_buf(rettv, buf1);
2940 		char_u	*s2 = NULL;
2941 
2942 		if (vim9script && (var2.v_type == VAR_VOID
2943 			|| var2.v_type == VAR_CHANNEL
2944 			|| var2.v_type == VAR_JOB))
2945 		    semsg(_(e_using_invalid_value_as_string_str),
2946 						   vartype_name(var2.v_type));
2947 #ifdef FEAT_FLOAT
2948 		else if (vim9script && var2.v_type == VAR_FLOAT)
2949 		{
2950 		    vim_snprintf((char *)buf2, NUMBUFLEN, "%g",
2951 							    var2.vval.v_float);
2952 		    s2 = buf2;
2953 		}
2954 #endif
2955 		else
2956 		    s2 = tv_get_string_buf_chk(&var2, buf2);
2957 		if (s2 == NULL)		// type error ?
2958 		{
2959 		    clear_tv(rettv);
2960 		    clear_tv(&var2);
2961 		    return FAIL;
2962 		}
2963 		p = concat_str(s1, s2);
2964 		clear_tv(rettv);
2965 		rettv->v_type = VAR_STRING;
2966 		rettv->vval.v_string = p;
2967 	    }
2968 	    else if (op == '+' && rettv->v_type == VAR_BLOB
2969 						   && var2.v_type == VAR_BLOB)
2970 		eval_addblob(rettv, &var2);
2971 	    else if (op == '+' && rettv->v_type == VAR_LIST
2972 						   && var2.v_type == VAR_LIST)
2973 	    {
2974 		if (eval_addlist(rettv, &var2) == FAIL)
2975 		    return FAIL;
2976 	    }
2977 	    else
2978 	    {
2979 		int		error = FALSE;
2980 		varnumber_T	n1, n2;
2981 #ifdef FEAT_FLOAT
2982 		float_T	    f1 = 0, f2 = 0;
2983 
2984 		if (rettv->v_type == VAR_FLOAT)
2985 		{
2986 		    f1 = rettv->vval.v_float;
2987 		    n1 = 0;
2988 		}
2989 		else
2990 #endif
2991 		{
2992 		    n1 = tv_get_number_chk(rettv, &error);
2993 		    if (error)
2994 		    {
2995 			// This can only happen for "list + non-list" or
2996 			// "blob + non-blob".  For "non-list + ..." or
2997 			// "something - ...", we returned before evaluating the
2998 			// 2nd operand.
2999 			clear_tv(rettv);
3000 			clear_tv(&var2);
3001 			return FAIL;
3002 		    }
3003 #ifdef FEAT_FLOAT
3004 		    if (var2.v_type == VAR_FLOAT)
3005 			f1 = n1;
3006 #endif
3007 		}
3008 #ifdef FEAT_FLOAT
3009 		if (var2.v_type == VAR_FLOAT)
3010 		{
3011 		    f2 = var2.vval.v_float;
3012 		    n2 = 0;
3013 		}
3014 		else
3015 #endif
3016 		{
3017 		    n2 = tv_get_number_chk(&var2, &error);
3018 		    if (error)
3019 		    {
3020 			clear_tv(rettv);
3021 			clear_tv(&var2);
3022 			return FAIL;
3023 		    }
3024 #ifdef FEAT_FLOAT
3025 		    if (rettv->v_type == VAR_FLOAT)
3026 			f2 = n2;
3027 #endif
3028 		}
3029 		clear_tv(rettv);
3030 
3031 #ifdef FEAT_FLOAT
3032 		// If there is a float on either side the result is a float.
3033 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3034 		{
3035 		    if (op == '+')
3036 			f1 = f1 + f2;
3037 		    else
3038 			f1 = f1 - f2;
3039 		    rettv->v_type = VAR_FLOAT;
3040 		    rettv->vval.v_float = f1;
3041 		}
3042 		else
3043 #endif
3044 		{
3045 		    if (op == '+')
3046 			n1 = n1 + n2;
3047 		    else
3048 			n1 = n1 - n2;
3049 		    rettv->v_type = VAR_NUMBER;
3050 		    rettv->vval.v_number = n1;
3051 		}
3052 	    }
3053 	    clear_tv(&var2);
3054 	}
3055     }
3056     return OK;
3057 }
3058 
3059 /*
3060  * Handle fifth level expression:
3061  *	*	number multiplication
3062  *	/	number division
3063  *	%	number modulo
3064  *
3065  * "arg" must point to the first non-white of the expression.
3066  * "arg" is advanced to just after the recognized expression.
3067  *
3068  * Return OK or FAIL.
3069  */
3070     static int
3071 eval6(
3072     char_u	**arg,
3073     typval_T	*rettv,
3074     evalarg_T	*evalarg,
3075     int		want_string)  // after "." operator
3076 {
3077 #ifdef FEAT_FLOAT
3078     int	    use_float = FALSE;
3079 #endif
3080 
3081     /*
3082      * Get the first variable.
3083      */
3084     if (eval7t(arg, rettv, evalarg, want_string) == FAIL)
3085 	return FAIL;
3086 
3087     /*
3088      * Repeat computing, until no '*', '/' or '%' is following.
3089      */
3090     for (;;)
3091     {
3092 	int	    evaluate;
3093 	int	    getnext;
3094 	typval_T    var2;
3095 	char_u	    *p;
3096 	int	    op;
3097 	varnumber_T n1, n2;
3098 #ifdef FEAT_FLOAT
3099 	float_T	    f1, f2;
3100 #endif
3101 	int	    error;
3102 
3103 	// "*=", "/=" and "%=" are assignments
3104 	p = eval_next_non_blank(*arg, evalarg, &getnext);
3105 	op = *p;
3106 	if ((op != '*' && op != '/' && op != '%') || p[1] == '=')
3107 	    break;
3108 
3109 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
3110 	if (getnext)
3111 	    *arg = eval_next_line(evalarg);
3112 	else
3113 	{
3114 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(**arg))
3115 	    {
3116 		error_white_both(*arg, 1);
3117 		clear_tv(rettv);
3118 		return FAIL;
3119 	    }
3120 	    *arg = p;
3121 	}
3122 
3123 #ifdef FEAT_FLOAT
3124 	f1 = 0;
3125 	f2 = 0;
3126 #endif
3127 	error = FALSE;
3128 	if (evaluate)
3129 	{
3130 #ifdef FEAT_FLOAT
3131 	    if (rettv->v_type == VAR_FLOAT)
3132 	    {
3133 		f1 = rettv->vval.v_float;
3134 		use_float = TRUE;
3135 		n1 = 0;
3136 	    }
3137 	    else
3138 #endif
3139 		n1 = tv_get_number_chk(rettv, &error);
3140 	    clear_tv(rettv);
3141 	    if (error)
3142 		return FAIL;
3143 	}
3144 	else
3145 	    n1 = 0;
3146 
3147 	/*
3148 	 * Get the second variable.
3149 	 */
3150 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[1]))
3151 	{
3152 	    error_white_both(*arg, 1);
3153 	    clear_tv(rettv);
3154 	    return FAIL;
3155 	}
3156 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3157 	if (eval7t(arg, &var2, evalarg, FALSE) == FAIL)
3158 	    return FAIL;
3159 
3160 	if (evaluate)
3161 	{
3162 #ifdef FEAT_FLOAT
3163 	    if (var2.v_type == VAR_FLOAT)
3164 	    {
3165 		if (!use_float)
3166 		{
3167 		    f1 = n1;
3168 		    use_float = TRUE;
3169 		}
3170 		f2 = var2.vval.v_float;
3171 		n2 = 0;
3172 	    }
3173 	    else
3174 #endif
3175 	    {
3176 		n2 = tv_get_number_chk(&var2, &error);
3177 		clear_tv(&var2);
3178 		if (error)
3179 		    return FAIL;
3180 #ifdef FEAT_FLOAT
3181 		if (use_float)
3182 		    f2 = n2;
3183 #endif
3184 	    }
3185 
3186 	    /*
3187 	     * Compute the result.
3188 	     * When either side is a float the result is a float.
3189 	     */
3190 #ifdef FEAT_FLOAT
3191 	    if (use_float)
3192 	    {
3193 		if (op == '*')
3194 		    f1 = f1 * f2;
3195 		else if (op == '/')
3196 		{
3197 # ifdef VMS
3198 		    // VMS crashes on divide by zero, work around it
3199 		    if (f2 == 0.0)
3200 		    {
3201 			if (f1 == 0)
3202 			    f1 = -1 * __F_FLT_MAX - 1L;   // similar to NaN
3203 			else if (f1 < 0)
3204 			    f1 = -1 * __F_FLT_MAX;
3205 			else
3206 			    f1 = __F_FLT_MAX;
3207 		    }
3208 		    else
3209 			f1 = f1 / f2;
3210 # else
3211 		    // We rely on the floating point library to handle divide
3212 		    // by zero to result in "inf" and not a crash.
3213 		    f1 = f1 / f2;
3214 # endif
3215 		}
3216 		else
3217 		{
3218 		    emsg(_(e_modulus));
3219 		    return FAIL;
3220 		}
3221 		rettv->v_type = VAR_FLOAT;
3222 		rettv->vval.v_float = f1;
3223 	    }
3224 	    else
3225 #endif
3226 	    {
3227 		int	    failed = FALSE;
3228 
3229 		if (op == '*')
3230 		    n1 = n1 * n2;
3231 		else if (op == '/')
3232 		    n1 = num_divide(n1, n2, &failed);
3233 		else
3234 		    n1 = num_modulus(n1, n2, &failed);
3235 		if (failed)
3236 		    return FAIL;
3237 
3238 		rettv->v_type = VAR_NUMBER;
3239 		rettv->vval.v_number = n1;
3240 	    }
3241 	}
3242     }
3243 
3244     return OK;
3245 }
3246 
3247 /*
3248  * Handle a type cast before a base level expression.
3249  * "arg" must point to the first non-white of the expression.
3250  * "arg" is advanced to just after the recognized expression.
3251  * Return OK or FAIL.
3252  */
3253     static int
3254 eval7t(
3255     char_u	**arg,
3256     typval_T	*rettv,
3257     evalarg_T	*evalarg,
3258     int		want_string)	// after "." operator
3259 {
3260     type_T	*want_type = NULL;
3261     garray_T	type_list;	    // list of pointers to allocated types
3262     int		res;
3263     int		evaluate = evalarg == NULL ? 0
3264 				       : (evalarg->eval_flags & EVAL_EVALUATE);
3265 
3266     // Recognize <type> in Vim9 script only.
3267     if (in_vim9script() && **arg == '<' && eval_isnamec1((*arg)[1])
3268 					     && STRNCMP(*arg, "<SNR>", 5) != 0)
3269     {
3270 	++*arg;
3271 	ga_init2(&type_list, sizeof(type_T *), 10);
3272 	want_type = parse_type(arg, &type_list, TRUE);
3273 	if (want_type == NULL && (evaluate || **arg != '>'))
3274 	{
3275 	    clear_type_list(&type_list);
3276 	    return FAIL;
3277 	}
3278 
3279 	if (**arg != '>')
3280 	{
3281 	    if (*skipwhite(*arg) == '>')
3282 		semsg(_(e_no_white_space_allowed_before_str_str), ">", *arg);
3283 	    else
3284 		emsg(_(e_missing_gt));
3285 	    clear_type_list(&type_list);
3286 	    return FAIL;
3287 	}
3288 	++*arg;
3289 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3290     }
3291 
3292     res = eval7(arg, rettv, evalarg, want_string);
3293 
3294     if (want_type != NULL && evaluate)
3295     {
3296 	if (res == OK)
3297 	{
3298 	    type_T *actual = typval2type(rettv, get_copyID(), &type_list, TRUE);
3299 
3300 	    if (!equal_type(want_type, actual, 0))
3301 	    {
3302 		if (want_type == &t_bool && actual != &t_bool
3303 					&& (actual->tt_flags & TTFLAG_BOOL_OK))
3304 		{
3305 		    int n = tv2bool(rettv);
3306 
3307 		    // can use "0" and "1" for boolean in some places
3308 		    clear_tv(rettv);
3309 		    rettv->v_type = VAR_BOOL;
3310 		    rettv->vval.v_number = n ? VVAL_TRUE : VVAL_FALSE;
3311 		}
3312 		else
3313 		{
3314 		    where_T where = WHERE_INIT;
3315 
3316 		    where.wt_variable = TRUE;
3317 		    res = check_type(want_type, actual, TRUE, where);
3318 		}
3319 	    }
3320 	}
3321 	clear_type_list(&type_list);
3322     }
3323 
3324     return res;
3325 }
3326 
3327     int
3328 eval_leader(char_u **arg, int vim9)
3329 {
3330     char_u	*s = *arg;
3331     char_u	*p = *arg;
3332 
3333     while (*p == '!' || *p == '-' || *p == '+')
3334     {
3335 	char_u *n = skipwhite(p + 1);
3336 
3337 	// ++, --, -+ and +- are not accepted in Vim9 script
3338 	if (vim9 && (*p == '-' || *p == '+') && (*n == '-' || *n == '+'))
3339 	{
3340 	    semsg(_(e_invalid_expression_str), s);
3341 	    return FAIL;
3342 	}
3343 	p = n;
3344     }
3345     *arg = p;
3346     return OK;
3347 }
3348 
3349 /*
3350  * Handle sixth level expression:
3351  *  number		number constant
3352  *  0zFFFFFFFF		Blob constant
3353  *  "string"		string constant
3354  *  'string'		literal string constant
3355  *  &option-name	option value
3356  *  @r			register contents
3357  *  identifier		variable value
3358  *  function()		function call
3359  *  $VAR		environment variable
3360  *  (expression)	nested expression
3361  *  [expr, expr]	List
3362  *  {arg, arg -> expr}	Lambda
3363  *  {key: val, key: val}   Dictionary
3364  *  #{key: val, key: val}  Dictionary with literal keys
3365  *
3366  *  Also handle:
3367  *  ! in front		logical NOT
3368  *  - in front		unary minus
3369  *  + in front		unary plus (ignored)
3370  *  trailing []		subscript in String or List
3371  *  trailing .name	entry in Dictionary
3372  *  trailing ->name()	method call
3373  *
3374  * "arg" must point to the first non-white of the expression.
3375  * "arg" is advanced to just after the recognized expression.
3376  *
3377  * Return OK or FAIL.
3378  */
3379     static int
3380 eval7(
3381     char_u	**arg,
3382     typval_T	*rettv,
3383     evalarg_T	*evalarg,
3384     int		want_string)	// after "." operator
3385 {
3386     int		evaluate = evalarg != NULL
3387 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3388     int		len;
3389     char_u	*s;
3390     char_u	*start_leader, *end_leader;
3391     int		ret = OK;
3392     char_u	*alias;
3393 
3394     /*
3395      * Initialise variable so that clear_tv() can't mistake this for a
3396      * string and free a string that isn't there.
3397      */
3398     rettv->v_type = VAR_UNKNOWN;
3399 
3400     /*
3401      * Skip '!', '-' and '+' characters.  They are handled later.
3402      */
3403     start_leader = *arg;
3404     if (eval_leader(arg, in_vim9script()) == FAIL)
3405 	return FAIL;
3406     end_leader = *arg;
3407 
3408     if (**arg == '.' && (!isdigit(*(*arg + 1))
3409 #ifdef FEAT_FLOAT
3410 	    || in_old_script(2)
3411 #endif
3412 	    ))
3413     {
3414 	semsg(_(e_invalid_expression_str), *arg);
3415 	++*arg;
3416 	return FAIL;
3417     }
3418 
3419     switch (**arg)
3420     {
3421     /*
3422      * Number constant.
3423      */
3424     case '0':
3425     case '1':
3426     case '2':
3427     case '3':
3428     case '4':
3429     case '5':
3430     case '6':
3431     case '7':
3432     case '8':
3433     case '9':
3434     case '.':	ret = eval_number(arg, rettv, evaluate, want_string);
3435 
3436 		// Apply prefixed "-" and "+" now.  Matters especially when
3437 		// "->" follows.
3438 		if (ret == OK && evaluate && end_leader > start_leader
3439 						  && rettv->v_type != VAR_BLOB)
3440 		    ret = eval7_leader(rettv, TRUE, start_leader, &end_leader);
3441 		break;
3442 
3443     /*
3444      * String constant: "string".
3445      */
3446     case '"':	ret = eval_string(arg, rettv, evaluate);
3447 		break;
3448 
3449     /*
3450      * Literal string constant: 'str''ing'.
3451      */
3452     case '\'':	ret = eval_lit_string(arg, rettv, evaluate);
3453 		break;
3454 
3455     /*
3456      * List: [expr, expr]
3457      */
3458     case '[':	ret = eval_list(arg, rettv, evalarg, TRUE);
3459 		break;
3460 
3461     /*
3462      * Dictionary: #{key: val, key: val}
3463      */
3464     case '#':	if (in_vim9script())
3465 		{
3466 		    ret = vim9_bad_comment(*arg) ? FAIL : NOTDONE;
3467 		}
3468 		else if ((*arg)[1] == '{')
3469 		{
3470 		    ++*arg;
3471 		    ret = eval_dict(arg, rettv, evalarg, TRUE);
3472 		}
3473 		else
3474 		    ret = NOTDONE;
3475 		break;
3476 
3477     /*
3478      * Lambda: {arg, arg -> expr}
3479      * Dictionary: {'key': val, 'key': val}
3480      */
3481     case '{':	if (in_vim9script())
3482 		    ret = NOTDONE;
3483 		else
3484 		    ret = get_lambda_tv(arg, rettv, in_vim9script(), evalarg);
3485 		if (ret == NOTDONE)
3486 		    ret = eval_dict(arg, rettv, evalarg, FALSE);
3487 		break;
3488 
3489     /*
3490      * Option value: &name
3491      */
3492     case '&':	ret = eval_option(arg, rettv, evaluate);
3493 		break;
3494 
3495     /*
3496      * Environment variable: $VAR.
3497      */
3498     case '$':	ret = eval_env_var(arg, rettv, evaluate);
3499 		break;
3500 
3501     /*
3502      * Register contents: @r.
3503      */
3504     case '@':	++*arg;
3505 		if (evaluate)
3506 		{
3507 		    if (in_vim9script() && IS_WHITE_OR_NUL(**arg))
3508 			semsg(_(e_syntax_error_at_str), *arg);
3509 		    else if (in_vim9script() && !valid_yank_reg(**arg, FALSE))
3510 			emsg_invreg(**arg);
3511 		    else
3512 		    {
3513 			rettv->v_type = VAR_STRING;
3514 			rettv->vval.v_string = get_reg_contents(**arg,
3515 								GREG_EXPR_SRC);
3516 		    }
3517 		}
3518 		if (**arg != NUL)
3519 		    ++*arg;
3520 		break;
3521 
3522     /*
3523      * nested expression: (expression).
3524      * or lambda: (arg) => expr
3525      */
3526     case '(':	ret = NOTDONE;
3527 		if (in_vim9script())
3528 		{
3529 		    ret = get_lambda_tv(arg, rettv, TRUE, evalarg);
3530 		    if (ret == OK && evaluate)
3531 		    {
3532 			ufunc_T *ufunc = rettv->vval.v_partial->pt_func;
3533 
3534 			// Compile it here to get the return type.  The return
3535 			// type is optional, when it's missing use t_unknown.
3536 			// This is recognized in compile_return().
3537 			if (ufunc->uf_ret_type->tt_type == VAR_VOID)
3538 			    ufunc->uf_ret_type = &t_unknown;
3539 			if (compile_def_function(ufunc,
3540 				     FALSE, COMPILE_TYPE(ufunc), NULL) == FAIL)
3541 			{
3542 			    clear_tv(rettv);
3543 			    ret = FAIL;
3544 			}
3545 		    }
3546 		}
3547 		if (ret == NOTDONE)
3548 		{
3549 		    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3550 		    ret = eval1(arg, rettv, evalarg);	// recursive!
3551 
3552 		    *arg = skipwhite_and_linebreak(*arg, evalarg);
3553 		    if (**arg == ')')
3554 			++*arg;
3555 		    else if (ret == OK)
3556 		    {
3557 			emsg(_(e_missing_close));
3558 			clear_tv(rettv);
3559 			ret = FAIL;
3560 		    }
3561 		}
3562 		break;
3563 
3564     default:	ret = NOTDONE;
3565 		break;
3566     }
3567 
3568     if (ret == NOTDONE)
3569     {
3570 	/*
3571 	 * Must be a variable or function name.
3572 	 * Can also be a curly-braces kind of name: {expr}.
3573 	 */
3574 	s = *arg;
3575 	len = get_name_len(arg, &alias, evaluate, TRUE);
3576 	if (alias != NULL)
3577 	    s = alias;
3578 
3579 	if (len <= 0)
3580 	    ret = FAIL;
3581 	else
3582 	{
3583 	    int	    flags = evalarg == NULL ? 0 : evalarg->eval_flags;
3584 
3585 	    if (evaluate && in_vim9script() && len == 1 && *s == '_')
3586 	    {
3587 		emsg(_(e_cannot_use_underscore_here));
3588 		ret = FAIL;
3589 	    }
3590 	    else if ((in_vim9script() ? **arg : *skipwhite(*arg)) == '(')
3591 	    {
3592 		// "name(..."  recursive!
3593 		*arg = skipwhite(*arg);
3594 		ret = eval_func(arg, evalarg, s, len, rettv, flags, NULL);
3595 	    }
3596 	    else if (flags & EVAL_CONSTANT)
3597 		ret = FAIL;
3598 	    else if (evaluate)
3599 	    {
3600 		// get the value of "true", "false" or a variable
3601 		if (len == 4 && in_vim9script() && STRNCMP(s, "true", 4) == 0)
3602 		{
3603 		    rettv->v_type = VAR_BOOL;
3604 		    rettv->vval.v_number = VVAL_TRUE;
3605 		    ret = OK;
3606 		}
3607 		else if (len == 5 && in_vim9script()
3608 						&& STRNCMP(s, "false", 5) == 0)
3609 		{
3610 		    rettv->v_type = VAR_BOOL;
3611 		    rettv->vval.v_number = VVAL_FALSE;
3612 		    ret = OK;
3613 		}
3614 		else if (len == 4 && in_vim9script()
3615 						&& STRNCMP(s, "null", 4) == 0)
3616 		{
3617 		    rettv->v_type = VAR_SPECIAL;
3618 		    rettv->vval.v_number = VVAL_NULL;
3619 		    ret = OK;
3620 		}
3621 		else
3622 		    ret = eval_variable(s, len, rettv, NULL,
3623 					   EVAL_VAR_VERBOSE + EVAL_VAR_IMPORT);
3624 	    }
3625 	    else
3626 	    {
3627 		// skip the name
3628 		check_vars(s, len);
3629 		ret = OK;
3630 	    }
3631 	}
3632 	vim_free(alias);
3633     }
3634 
3635     // Handle following '[', '(' and '.' for expr[expr], expr.name,
3636     // expr(expr), expr->name(expr)
3637     if (ret == OK)
3638 	ret = handle_subscript(arg, rettv, evalarg, TRUE);
3639 
3640     /*
3641      * Apply logical NOT and unary '-', from right to left, ignore '+'.
3642      */
3643     if (ret == OK && evaluate && end_leader > start_leader)
3644 	ret = eval7_leader(rettv, FALSE, start_leader, &end_leader);
3645     return ret;
3646 }
3647 
3648 /*
3649  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
3650  * When "numeric_only" is TRUE only handle "+" and "-".
3651  * Adjusts "end_leaderp" until it is at "start_leader".
3652  */
3653     static int
3654 eval7_leader(
3655 	typval_T    *rettv,
3656 	int	    numeric_only,
3657 	char_u	    *start_leader,
3658 	char_u	    **end_leaderp)
3659 {
3660     char_u	*end_leader = *end_leaderp;
3661     int		ret = OK;
3662     int		error = FALSE;
3663     varnumber_T val = 0;
3664     vartype_T	type = rettv->v_type;
3665 #ifdef FEAT_FLOAT
3666     float_T	    f = 0.0;
3667 
3668     if (rettv->v_type == VAR_FLOAT)
3669 	f = rettv->vval.v_float;
3670     else
3671 #endif
3672     {
3673 	while (VIM_ISWHITE(end_leader[-1]))
3674 	    --end_leader;
3675 	if (in_vim9script() && end_leader[-1] == '!')
3676 	    val = tv2bool(rettv);
3677 	else
3678 	    val = tv_get_number_chk(rettv, &error);
3679     }
3680     if (error)
3681     {
3682 	clear_tv(rettv);
3683 	ret = FAIL;
3684     }
3685     else
3686     {
3687 	while (end_leader > start_leader)
3688 	{
3689 	    --end_leader;
3690 	    if (*end_leader == '!')
3691 	    {
3692 		if (numeric_only)
3693 		{
3694 		    ++end_leader;
3695 		    break;
3696 		}
3697 #ifdef FEAT_FLOAT
3698 		if (rettv->v_type == VAR_FLOAT)
3699 		{
3700 		    if (in_vim9script())
3701 		    {
3702 			rettv->v_type = VAR_BOOL;
3703 			val = f == 0.0 ? VVAL_TRUE : VVAL_FALSE;
3704 		    }
3705 		    else
3706 			f = !f;
3707 		}
3708 		else
3709 #endif
3710 		{
3711 		    val = !val;
3712 		    type = VAR_BOOL;
3713 		}
3714 	    }
3715 	    else if (*end_leader == '-')
3716 	    {
3717 #ifdef FEAT_FLOAT
3718 		if (rettv->v_type == VAR_FLOAT)
3719 		    f = -f;
3720 		else
3721 #endif
3722 		{
3723 		    val = -val;
3724 		    type = VAR_NUMBER;
3725 		}
3726 	    }
3727 	}
3728 #ifdef FEAT_FLOAT
3729 	if (rettv->v_type == VAR_FLOAT)
3730 	{
3731 	    clear_tv(rettv);
3732 	    rettv->vval.v_float = f;
3733 	}
3734 	else
3735 #endif
3736 	{
3737 	    clear_tv(rettv);
3738 	    if (in_vim9script())
3739 		rettv->v_type = type;
3740 	    else
3741 		rettv->v_type = VAR_NUMBER;
3742 	    rettv->vval.v_number = val;
3743 	}
3744     }
3745     *end_leaderp = end_leader;
3746     return ret;
3747 }
3748 
3749 /*
3750  * Call the function referred to in "rettv".
3751  */
3752     static int
3753 call_func_rettv(
3754 	char_u	    **arg,
3755 	evalarg_T   *evalarg,
3756 	typval_T    *rettv,
3757 	int	    evaluate,
3758 	dict_T	    *selfdict,
3759 	typval_T    *basetv)
3760 {
3761     partial_T	*pt = NULL;
3762     funcexe_T	funcexe;
3763     typval_T	functv;
3764     char_u	*s;
3765     int		ret;
3766 
3767     // need to copy the funcref so that we can clear rettv
3768     if (evaluate)
3769     {
3770 	functv = *rettv;
3771 	rettv->v_type = VAR_UNKNOWN;
3772 
3773 	// Invoke the function.  Recursive!
3774 	if (functv.v_type == VAR_PARTIAL)
3775 	{
3776 	    pt = functv.vval.v_partial;
3777 	    s = partial_name(pt);
3778 	}
3779 	else
3780 	{
3781 	    s = functv.vval.v_string;
3782 	    if (s == NULL || *s == NUL)
3783 	    {
3784 		emsg(_(e_empty_function_name));
3785 		ret = FAIL;
3786 		goto theend;
3787 	    }
3788 	}
3789     }
3790     else
3791 	s = (char_u *)"";
3792 
3793     CLEAR_FIELD(funcexe);
3794     funcexe.firstline = curwin->w_cursor.lnum;
3795     funcexe.lastline = curwin->w_cursor.lnum;
3796     funcexe.evaluate = evaluate;
3797     funcexe.partial = pt;
3798     funcexe.selfdict = selfdict;
3799     funcexe.basetv = basetv;
3800     ret = get_func_tv(s, -1, rettv, arg, evalarg, &funcexe);
3801 
3802 theend:
3803     // Clear the funcref afterwards, so that deleting it while
3804     // evaluating the arguments is possible (see test55).
3805     if (evaluate)
3806 	clear_tv(&functv);
3807 
3808     return ret;
3809 }
3810 
3811 /*
3812  * Evaluate "->method()".
3813  * "*arg" points to "method".
3814  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3815  */
3816     static int
3817 eval_lambda(
3818     char_u	**arg,
3819     typval_T	*rettv,
3820     evalarg_T	*evalarg,
3821     int		verbose)	// give error messages
3822 {
3823     int		evaluate = evalarg != NULL
3824 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3825     typval_T	base = *rettv;
3826     int		ret;
3827 
3828     rettv->v_type = VAR_UNKNOWN;
3829 
3830     if (**arg == '{')
3831     {
3832 	// ->{lambda}()
3833 	ret = get_lambda_tv(arg, rettv, FALSE, evalarg);
3834     }
3835     else
3836     {
3837 	// ->(lambda)()
3838 	++*arg;
3839 	ret = eval1(arg, rettv, evalarg);
3840 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3841 	if (**arg != ')')
3842 	{
3843 	    emsg(_(e_missing_close));
3844 	    ret = FAIL;
3845 	}
3846 	++*arg;
3847     }
3848     if (ret != OK)
3849 	return FAIL;
3850     else if (**arg != '(')
3851     {
3852 	if (verbose)
3853 	{
3854 	    if (*skipwhite(*arg) == '(')
3855 		emsg(_(e_nowhitespace));
3856 	    else
3857 		semsg(_(e_missing_paren), "lambda");
3858 	}
3859 	clear_tv(rettv);
3860 	ret = FAIL;
3861     }
3862     else
3863 	ret = call_func_rettv(arg, evalarg, rettv, evaluate, NULL, &base);
3864 
3865     // Clear the funcref afterwards, so that deleting it while
3866     // evaluating the arguments is possible (see test55).
3867     if (evaluate)
3868 	clear_tv(&base);
3869 
3870     return ret;
3871 }
3872 
3873 /*
3874  * Evaluate "->method()".
3875  * "*arg" points to "method".
3876  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3877  */
3878     static int
3879 eval_method(
3880     char_u	**arg,
3881     typval_T	*rettv,
3882     evalarg_T	*evalarg,
3883     int		verbose)	// give error messages
3884 {
3885     char_u	*name;
3886     long	len;
3887     char_u	*alias;
3888     typval_T	base = *rettv;
3889     int		ret;
3890     int		evaluate = evalarg != NULL
3891 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3892 
3893     rettv->v_type = VAR_UNKNOWN;
3894 
3895     name = *arg;
3896     len = get_name_len(arg, &alias, evaluate, TRUE);
3897     if (alias != NULL)
3898 	name = alias;
3899 
3900     if (len <= 0)
3901     {
3902 	if (verbose)
3903 	    emsg(_("E260: Missing name after ->"));
3904 	ret = FAIL;
3905     }
3906     else
3907     {
3908 	*arg = skipwhite(*arg);
3909 	if (**arg != '(')
3910 	{
3911 	    if (verbose)
3912 		semsg(_(e_missing_paren), name);
3913 	    ret = FAIL;
3914 	}
3915 	else if (VIM_ISWHITE((*arg)[-1]))
3916 	{
3917 	    if (verbose)
3918 		emsg(_(e_nowhitespace));
3919 	    ret = FAIL;
3920 	}
3921 	else
3922 	    ret = eval_func(arg, evalarg, name, len, rettv,
3923 					  evaluate ? EVAL_EVALUATE : 0, &base);
3924     }
3925 
3926     // Clear the funcref afterwards, so that deleting it while
3927     // evaluating the arguments is possible (see test55).
3928     if (evaluate)
3929 	clear_tv(&base);
3930 
3931     return ret;
3932 }
3933 
3934 /*
3935  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
3936  * "*arg" points to the '[' or '.'.
3937  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
3938  */
3939     static int
3940 eval_index(
3941     char_u	**arg,
3942     typval_T	*rettv,
3943     evalarg_T	*evalarg,
3944     int		verbose)	// give error messages
3945 {
3946     int		evaluate = evalarg != NULL
3947 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3948     int		empty1 = FALSE, empty2 = FALSE;
3949     typval_T	var1, var2;
3950     int		range = FALSE;
3951     char_u	*key = NULL;
3952     int		keylen = -1;
3953     int		vim9 = in_vim9script();
3954 
3955     if (check_can_index(rettv, evaluate, verbose) == FAIL)
3956 	return FAIL;
3957 
3958     init_tv(&var1);
3959     init_tv(&var2);
3960     if (**arg == '.')
3961     {
3962 	/*
3963 	 * dict.name
3964 	 */
3965 	key = *arg + 1;
3966 	for (keylen = 0; eval_isdictc(key[keylen]); ++keylen)
3967 	    ;
3968 	if (keylen == 0)
3969 	    return FAIL;
3970 	*arg = key + keylen;
3971     }
3972     else
3973     {
3974 	/*
3975 	 * something[idx]
3976 	 *
3977 	 * Get the (first) variable from inside the [].
3978 	 */
3979 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3980 	if (**arg == ':')
3981 	    empty1 = TRUE;
3982 	else if (eval1(arg, &var1, evalarg) == FAIL)	// recursive!
3983 	    return FAIL;
3984 	else if (vim9 && **arg == ':')
3985 	{
3986 	    semsg(_(e_white_space_required_before_and_after_str_at_str),
3987 								    ":", *arg);
3988 	    clear_tv(&var1);
3989 	    return FAIL;
3990 	}
3991 	else if (evaluate)
3992 	{
3993 #ifdef FEAT_FLOAT
3994 	    // allow for indexing with float
3995 	    if (vim9 && rettv->v_type == VAR_DICT
3996 						   && var1.v_type == VAR_FLOAT)
3997 	    {
3998 		var1.vval.v_string = typval_tostring(&var1, TRUE);
3999 		var1.v_type = VAR_STRING;
4000 	    }
4001 #endif
4002 	    if (tv_get_string_chk(&var1) == NULL)
4003 	    {
4004 		// not a number or string
4005 		clear_tv(&var1);
4006 		return FAIL;
4007 	    }
4008 	}
4009 
4010 	/*
4011 	 * Get the second variable from inside the [:].
4012 	 */
4013 	*arg = skipwhite_and_linebreak(*arg, evalarg);
4014 	if (**arg == ':')
4015 	{
4016 	    range = TRUE;
4017 	    ++*arg;
4018 	    if (vim9 && !IS_WHITE_OR_NUL(**arg) && **arg != ']')
4019 	    {
4020 		semsg(_(e_white_space_required_before_and_after_str_at_str),
4021 								":", *arg - 1);
4022 		if (!empty1)
4023 		    clear_tv(&var1);
4024 		return FAIL;
4025 	    }
4026 	    *arg = skipwhite_and_linebreak(*arg, evalarg);
4027 	    if (**arg == ']')
4028 		empty2 = TRUE;
4029 	    else if (eval1(arg, &var2, evalarg) == FAIL)	// recursive!
4030 	    {
4031 		if (!empty1)
4032 		    clear_tv(&var1);
4033 		return FAIL;
4034 	    }
4035 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
4036 	    {
4037 		// not a number or string
4038 		if (!empty1)
4039 		    clear_tv(&var1);
4040 		clear_tv(&var2);
4041 		return FAIL;
4042 	    }
4043 	}
4044 
4045 	// Check for the ']'.
4046 	*arg = skipwhite_and_linebreak(*arg, evalarg);
4047 	if (**arg != ']')
4048 	{
4049 	    if (verbose)
4050 		emsg(_(e_missbrac));
4051 	    clear_tv(&var1);
4052 	    if (range)
4053 		clear_tv(&var2);
4054 	    return FAIL;
4055 	}
4056 	*arg = *arg + 1;	// skip over the ']'
4057     }
4058 
4059     if (evaluate)
4060     {
4061 	int res = eval_index_inner(rettv, range,
4062 		empty1 ? NULL : &var1, empty2 ? NULL : &var2, FALSE,
4063 		key, keylen, verbose);
4064 
4065 	if (!empty1)
4066 	    clear_tv(&var1);
4067 	if (range)
4068 	    clear_tv(&var2);
4069 	return res;
4070     }
4071     return OK;
4072 }
4073 
4074 /*
4075  * Check if "rettv" can have an [index] or [sli:ce]
4076  */
4077     int
4078 check_can_index(typval_T *rettv, int evaluate, int verbose)
4079 {
4080     switch (rettv->v_type)
4081     {
4082 	case VAR_FUNC:
4083 	case VAR_PARTIAL:
4084 	    if (verbose)
4085 		emsg(_("E695: Cannot index a Funcref"));
4086 	    return FAIL;
4087 	case VAR_FLOAT:
4088 #ifdef FEAT_FLOAT
4089 	    if (verbose)
4090 		emsg(_(e_float_as_string));
4091 	    return FAIL;
4092 #endif
4093 	case VAR_BOOL:
4094 	case VAR_SPECIAL:
4095 	case VAR_JOB:
4096 	case VAR_CHANNEL:
4097 	case VAR_INSTR:
4098 	    if (verbose)
4099 		emsg(_(e_cannot_index_special_variable));
4100 	    return FAIL;
4101 	case VAR_UNKNOWN:
4102 	case VAR_ANY:
4103 	case VAR_VOID:
4104 	    if (evaluate)
4105 	    {
4106 		emsg(_(e_cannot_index_special_variable));
4107 		return FAIL;
4108 	    }
4109 	    // FALLTHROUGH
4110 
4111 	case VAR_STRING:
4112 	case VAR_LIST:
4113 	case VAR_DICT:
4114 	case VAR_BLOB:
4115 	    break;
4116 	case VAR_NUMBER:
4117 	    if (in_vim9script())
4118 		emsg(_(e_cannot_index_number));
4119 	    break;
4120     }
4121     return OK;
4122 }
4123 
4124 /*
4125  * slice() function
4126  */
4127     void
4128 f_slice(typval_T *argvars, typval_T *rettv)
4129 {
4130     if (in_vim9script()
4131 	    && ((argvars[0].v_type != VAR_STRING
4132 		    && argvars[0].v_type != VAR_LIST
4133 		    && argvars[0].v_type != VAR_BLOB
4134 		    && check_for_list_arg(argvars, 0) == FAIL)
4135 		|| check_for_number_arg(argvars, 1) == FAIL
4136 		|| check_for_opt_number_arg(argvars, 2) == FAIL))
4137 	return;
4138 
4139     if (check_can_index(argvars, TRUE, FALSE) == OK)
4140     {
4141 	copy_tv(argvars, rettv);
4142 	eval_index_inner(rettv, TRUE, argvars + 1,
4143 		argvars[2].v_type == VAR_UNKNOWN ? NULL : argvars + 2,
4144 		TRUE, NULL, 0, FALSE);
4145     }
4146 }
4147 
4148 /*
4149  * Apply index or range to "rettv".
4150  * "var1" is the first index, NULL for [:expr].
4151  * "var2" is the second index, NULL for [expr] and [expr: ]
4152  * "exclusive" is TRUE for slice(): second index is exclusive, use character
4153  * index for string.
4154  * Alternatively, "key" is not NULL, then key[keylen] is the dict index.
4155  */
4156     int
4157 eval_index_inner(
4158 	typval_T    *rettv,
4159 	int	    is_range,
4160 	typval_T    *var1,
4161 	typval_T    *var2,
4162 	int	    exclusive,
4163 	char_u	    *key,
4164 	int	    keylen,
4165 	int	    verbose)
4166 {
4167     varnumber_T	    n1, n2 = 0;
4168     long	    len;
4169 
4170     n1 = 0;
4171     if (var1 != NULL && rettv->v_type != VAR_DICT)
4172 	n1 = tv_get_number(var1);
4173 
4174     if (is_range)
4175     {
4176 	if (rettv->v_type == VAR_DICT)
4177 	{
4178 	    if (verbose)
4179 		emsg(_(e_cannot_slice_dictionary));
4180 	    return FAIL;
4181 	}
4182 	if (var2 != NULL)
4183 	    n2 = tv_get_number(var2);
4184 	else
4185 	    n2 = VARNUM_MAX;
4186     }
4187 
4188     switch (rettv->v_type)
4189     {
4190 	case VAR_UNKNOWN:
4191 	case VAR_ANY:
4192 	case VAR_VOID:
4193 	case VAR_FUNC:
4194 	case VAR_PARTIAL:
4195 	case VAR_FLOAT:
4196 	case VAR_BOOL:
4197 	case VAR_SPECIAL:
4198 	case VAR_JOB:
4199 	case VAR_CHANNEL:
4200 	case VAR_INSTR:
4201 	    break; // not evaluating, skipping over subscript
4202 
4203 	case VAR_NUMBER:
4204 	case VAR_STRING:
4205 	    {
4206 		char_u	*s = tv_get_string(rettv);
4207 
4208 		len = (long)STRLEN(s);
4209 		if (in_vim9script() || exclusive)
4210 		{
4211 		    if (is_range)
4212 			s = string_slice(s, n1, n2, exclusive);
4213 		    else
4214 			s = char_from_string(s, n1);
4215 		}
4216 		else if (is_range)
4217 		{
4218 		    // The resulting variable is a substring.  If the indexes
4219 		    // are out of range the result is empty.
4220 		    if (n1 < 0)
4221 		    {
4222 			n1 = len + n1;
4223 			if (n1 < 0)
4224 			    n1 = 0;
4225 		    }
4226 		    if (n2 < 0)
4227 			n2 = len + n2;
4228 		    else if (n2 >= len)
4229 			n2 = len;
4230 		    if (n1 >= len || n2 < 0 || n1 > n2)
4231 			s = NULL;
4232 		    else
4233 			s = vim_strnsave(s + n1, n2 - n1 + 1);
4234 		}
4235 		else
4236 		{
4237 		    // The resulting variable is a string of a single
4238 		    // character.  If the index is too big or negative the
4239 		    // result is empty.
4240 		    if (n1 >= len || n1 < 0)
4241 			s = NULL;
4242 		    else
4243 			s = vim_strnsave(s + n1, 1);
4244 		}
4245 		clear_tv(rettv);
4246 		rettv->v_type = VAR_STRING;
4247 		rettv->vval.v_string = s;
4248 	    }
4249 	    break;
4250 
4251 	case VAR_BLOB:
4252 	    blob_slice_or_index(rettv->vval.v_blob, is_range, n1, n2,
4253 							     exclusive, rettv);
4254 	    break;
4255 
4256 	case VAR_LIST:
4257 	    if (var1 == NULL)
4258 		n1 = 0;
4259 	    if (var2 == NULL)
4260 		n2 = VARNUM_MAX;
4261 	    if (list_slice_or_index(rettv->vval.v_list,
4262 			  is_range, n1, n2, exclusive, rettv, verbose) == FAIL)
4263 		return FAIL;
4264 	    break;
4265 
4266 	case VAR_DICT:
4267 	    {
4268 		dictitem_T	*item;
4269 		typval_T	tmp;
4270 
4271 		if (key == NULL)
4272 		{
4273 		    key = tv_get_string_chk(var1);
4274 		    if (key == NULL)
4275 			return FAIL;
4276 		}
4277 
4278 		item = dict_find(rettv->vval.v_dict, key, (int)keylen);
4279 
4280 		if (item == NULL && verbose)
4281 		    semsg(_(e_dictkey), key);
4282 		if (item == NULL)
4283 		    return FAIL;
4284 
4285 		copy_tv(&item->di_tv, &tmp);
4286 		clear_tv(rettv);
4287 		*rettv = tmp;
4288 	    }
4289 	    break;
4290     }
4291     return OK;
4292 }
4293 
4294 /*
4295  * Return the function name of partial "pt".
4296  */
4297     char_u *
4298 partial_name(partial_T *pt)
4299 {
4300     if (pt != NULL)
4301     {
4302 	if (pt->pt_name != NULL)
4303 	    return pt->pt_name;
4304 	if (pt->pt_func != NULL)
4305 	    return pt->pt_func->uf_name;
4306     }
4307     return (char_u *)"";
4308 }
4309 
4310     static void
4311 partial_free(partial_T *pt)
4312 {
4313     int i;
4314 
4315     for (i = 0; i < pt->pt_argc; ++i)
4316 	clear_tv(&pt->pt_argv[i]);
4317     vim_free(pt->pt_argv);
4318     dict_unref(pt->pt_dict);
4319     if (pt->pt_name != NULL)
4320     {
4321 	func_unref(pt->pt_name);
4322 	vim_free(pt->pt_name);
4323     }
4324     else
4325 	func_ptr_unref(pt->pt_func);
4326 
4327     // "out_up" is no longer used, decrement refcount on partial that owns it.
4328     partial_unref(pt->pt_outer.out_up_partial);
4329 
4330     // Decrease the reference count for the context of a closure.  If down
4331     // to the minimum it may be time to free it.
4332     if (pt->pt_funcstack != NULL)
4333     {
4334 	--pt->pt_funcstack->fs_refcount;
4335 	funcstack_check_refcount(pt->pt_funcstack);
4336     }
4337 
4338     vim_free(pt);
4339 }
4340 
4341 /*
4342  * Unreference a closure: decrement the reference count and free it when it
4343  * becomes zero.
4344  */
4345     void
4346 partial_unref(partial_T *pt)
4347 {
4348     if (pt != NULL)
4349     {
4350 	if (--pt->pt_refcount <= 0)
4351 	    partial_free(pt);
4352 
4353 	// If the reference count goes down to one, the funcstack may be the
4354 	// only reference and can be freed if no other partials reference it.
4355 	else if (pt->pt_refcount == 1 && pt->pt_funcstack != NULL)
4356 	    funcstack_check_refcount(pt->pt_funcstack);
4357     }
4358 }
4359 
4360 /*
4361  * Return the next (unique) copy ID.
4362  * Used for serializing nested structures.
4363  */
4364     int
4365 get_copyID(void)
4366 {
4367     current_copyID += COPYID_INC;
4368     return current_copyID;
4369 }
4370 
4371 /*
4372  * Garbage collection for lists and dictionaries.
4373  *
4374  * We use reference counts to be able to free most items right away when they
4375  * are no longer used.  But for composite items it's possible that it becomes
4376  * unused while the reference count is > 0: When there is a recursive
4377  * reference.  Example:
4378  *	:let l = [1, 2, 3]
4379  *	:let d = {9: l}
4380  *	:let l[1] = d
4381  *
4382  * Since this is quite unusual we handle this with garbage collection: every
4383  * once in a while find out which lists and dicts are not referenced from any
4384  * variable.
4385  *
4386  * Here is a good reference text about garbage collection (refers to Python
4387  * but it applies to all reference-counting mechanisms):
4388  *	http://python.ca/nas/python/gc/
4389  */
4390 
4391 /*
4392  * Do garbage collection for lists and dicts.
4393  * When "testing" is TRUE this is called from test_garbagecollect_now().
4394  * Return TRUE if some memory was freed.
4395  */
4396     int
4397 garbage_collect(int testing)
4398 {
4399     int		copyID;
4400     int		abort = FALSE;
4401     buf_T	*buf;
4402     win_T	*wp;
4403     int		did_free = FALSE;
4404     tabpage_T	*tp;
4405 
4406     if (!testing)
4407     {
4408 	// Only do this once.
4409 	want_garbage_collect = FALSE;
4410 	may_garbage_collect = FALSE;
4411 	garbage_collect_at_exit = FALSE;
4412     }
4413 
4414     // The execution stack can grow big, limit the size.
4415     if (exestack.ga_maxlen - exestack.ga_len > 500)
4416     {
4417 	size_t	new_len;
4418 	char_u	*pp;
4419 	int	n;
4420 
4421 	// Keep 150% of the current size, with a minimum of the growth size.
4422 	n = exestack.ga_len / 2;
4423 	if (n < exestack.ga_growsize)
4424 	    n = exestack.ga_growsize;
4425 
4426 	// Don't make it bigger though.
4427 	if (exestack.ga_len + n < exestack.ga_maxlen)
4428 	{
4429 	    new_len = exestack.ga_itemsize * (exestack.ga_len + n);
4430 	    pp = vim_realloc(exestack.ga_data, new_len);
4431 	    if (pp == NULL)
4432 		return FAIL;
4433 	    exestack.ga_maxlen = exestack.ga_len + n;
4434 	    exestack.ga_data = pp;
4435 	}
4436     }
4437 
4438     // We advance by two because we add one for items referenced through
4439     // previous_funccal.
4440     copyID = get_copyID();
4441 
4442     /*
4443      * 1. Go through all accessible variables and mark all lists and dicts
4444      *    with copyID.
4445      */
4446 
4447     // Don't free variables in the previous_funccal list unless they are only
4448     // referenced through previous_funccal.  This must be first, because if
4449     // the item is referenced elsewhere the funccal must not be freed.
4450     abort = abort || set_ref_in_previous_funccal(copyID);
4451 
4452     // script-local variables
4453     abort = abort || garbage_collect_scriptvars(copyID);
4454 
4455     // buffer-local variables
4456     FOR_ALL_BUFFERS(buf)
4457 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
4458 								  NULL, NULL);
4459 
4460     // window-local variables
4461     FOR_ALL_TAB_WINDOWS(tp, wp)
4462 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4463 								  NULL, NULL);
4464     if (aucmd_win != NULL)
4465 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
4466 								  NULL, NULL);
4467 #ifdef FEAT_PROP_POPUP
4468     FOR_ALL_POPUPWINS(wp)
4469 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4470 								  NULL, NULL);
4471     FOR_ALL_TABPAGES(tp)
4472 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
4473 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4474 								  NULL, NULL);
4475 #endif
4476 
4477     // tabpage-local variables
4478     FOR_ALL_TABPAGES(tp)
4479 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
4480 								  NULL, NULL);
4481     // global variables
4482     abort = abort || garbage_collect_globvars(copyID);
4483 
4484     // function-local variables
4485     abort = abort || set_ref_in_call_stack(copyID);
4486 
4487     // named functions (matters for closures)
4488     abort = abort || set_ref_in_functions(copyID);
4489 
4490     // function call arguments, if v:testing is set.
4491     abort = abort || set_ref_in_func_args(copyID);
4492 
4493     // v: vars
4494     abort = abort || garbage_collect_vimvars(copyID);
4495 
4496     // callbacks in buffers
4497     abort = abort || set_ref_in_buffers(copyID);
4498 
4499 #ifdef FEAT_LUA
4500     abort = abort || set_ref_in_lua(copyID);
4501 #endif
4502 
4503 #ifdef FEAT_PYTHON
4504     abort = abort || set_ref_in_python(copyID);
4505 #endif
4506 
4507 #ifdef FEAT_PYTHON3
4508     abort = abort || set_ref_in_python3(copyID);
4509 #endif
4510 
4511 #ifdef FEAT_JOB_CHANNEL
4512     abort = abort || set_ref_in_channel(copyID);
4513     abort = abort || set_ref_in_job(copyID);
4514 #endif
4515 #ifdef FEAT_NETBEANS_INTG
4516     abort = abort || set_ref_in_nb_channel(copyID);
4517 #endif
4518 
4519 #ifdef FEAT_TIMERS
4520     abort = abort || set_ref_in_timer(copyID);
4521 #endif
4522 
4523 #ifdef FEAT_QUICKFIX
4524     abort = abort || set_ref_in_quickfix(copyID);
4525 #endif
4526 
4527 #ifdef FEAT_TERMINAL
4528     abort = abort || set_ref_in_term(copyID);
4529 #endif
4530 
4531 #ifdef FEAT_PROP_POPUP
4532     abort = abort || set_ref_in_popups(copyID);
4533 #endif
4534 
4535     if (!abort)
4536     {
4537 	/*
4538 	 * 2. Free lists and dictionaries that are not referenced.
4539 	 */
4540 	did_free = free_unref_items(copyID);
4541 
4542 	/*
4543 	 * 3. Check if any funccal can be freed now.
4544 	 *    This may call us back recursively.
4545 	 */
4546 	free_unref_funccal(copyID, testing);
4547     }
4548     else if (p_verbose > 0)
4549     {
4550 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
4551     }
4552 
4553     return did_free;
4554 }
4555 
4556 /*
4557  * Free lists, dictionaries, channels and jobs that are no longer referenced.
4558  */
4559     static int
4560 free_unref_items(int copyID)
4561 {
4562     int		did_free = FALSE;
4563 
4564     // Let all "free" functions know that we are here.  This means no
4565     // dictionaries, lists, channels or jobs are to be freed, because we will
4566     // do that here.
4567     in_free_unref_items = TRUE;
4568 
4569     /*
4570      * PASS 1: free the contents of the items.  We don't free the items
4571      * themselves yet, so that it is possible to decrement refcount counters
4572      */
4573 
4574     // Go through the list of dicts and free items without the copyID.
4575     did_free |= dict_free_nonref(copyID);
4576 
4577     // Go through the list of lists and free items without the copyID.
4578     did_free |= list_free_nonref(copyID);
4579 
4580 #ifdef FEAT_JOB_CHANNEL
4581     // Go through the list of jobs and free items without the copyID. This
4582     // must happen before doing channels, because jobs refer to channels, but
4583     // the reference from the channel to the job isn't tracked.
4584     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4585 
4586     // Go through the list of channels and free items without the copyID.
4587     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4588 #endif
4589 
4590     /*
4591      * PASS 2: free the items themselves.
4592      */
4593     dict_free_items(copyID);
4594     list_free_items(copyID);
4595 
4596 #ifdef FEAT_JOB_CHANNEL
4597     // Go through the list of jobs and free items without the copyID. This
4598     // must happen before doing channels, because jobs refer to channels, but
4599     // the reference from the channel to the job isn't tracked.
4600     free_unused_jobs(copyID, COPYID_MASK);
4601 
4602     // Go through the list of channels and free items without the copyID.
4603     free_unused_channels(copyID, COPYID_MASK);
4604 #endif
4605 
4606     in_free_unref_items = FALSE;
4607 
4608     return did_free;
4609 }
4610 
4611 /*
4612  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4613  * "list_stack" is used to add lists to be marked.  Can be NULL.
4614  *
4615  * Returns TRUE if setting references failed somehow.
4616  */
4617     int
4618 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4619 {
4620     int		todo;
4621     int		abort = FALSE;
4622     hashitem_T	*hi;
4623     hashtab_T	*cur_ht;
4624     ht_stack_T	*ht_stack = NULL;
4625     ht_stack_T	*tempitem;
4626 
4627     cur_ht = ht;
4628     for (;;)
4629     {
4630 	if (!abort)
4631 	{
4632 	    // Mark each item in the hashtab.  If the item contains a hashtab
4633 	    // it is added to ht_stack, if it contains a list it is added to
4634 	    // list_stack.
4635 	    todo = (int)cur_ht->ht_used;
4636 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4637 		if (!HASHITEM_EMPTY(hi))
4638 		{
4639 		    --todo;
4640 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4641 						       &ht_stack, list_stack);
4642 		}
4643 	}
4644 
4645 	if (ht_stack == NULL)
4646 	    break;
4647 
4648 	// take an item from the stack
4649 	cur_ht = ht_stack->ht;
4650 	tempitem = ht_stack;
4651 	ht_stack = ht_stack->prev;
4652 	free(tempitem);
4653     }
4654 
4655     return abort;
4656 }
4657 
4658 /*
4659  * Mark a dict and its items with "copyID".
4660  * Returns TRUE if setting references failed somehow.
4661  */
4662     int
4663 set_ref_in_dict(dict_T *d, int copyID)
4664 {
4665     if (d != NULL && d->dv_copyID != copyID)
4666     {
4667 	d->dv_copyID = copyID;
4668 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4669     }
4670     return FALSE;
4671 }
4672 
4673 /*
4674  * Mark a list and its items with "copyID".
4675  * Returns TRUE if setting references failed somehow.
4676  */
4677     int
4678 set_ref_in_list(list_T *ll, int copyID)
4679 {
4680     if (ll != NULL && ll->lv_copyID != copyID)
4681     {
4682 	ll->lv_copyID = copyID;
4683 	return set_ref_in_list_items(ll, copyID, NULL);
4684     }
4685     return FALSE;
4686 }
4687 
4688 /*
4689  * Mark all lists and dicts referenced through list "l" with "copyID".
4690  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4691  *
4692  * Returns TRUE if setting references failed somehow.
4693  */
4694     int
4695 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4696 {
4697     listitem_T	 *li;
4698     int		 abort = FALSE;
4699     list_T	 *cur_l;
4700     list_stack_T *list_stack = NULL;
4701     list_stack_T *tempitem;
4702 
4703     cur_l = l;
4704     for (;;)
4705     {
4706 	if (!abort && cur_l->lv_first != &range_list_item)
4707 	    // Mark each item in the list.  If the item contains a hashtab
4708 	    // it is added to ht_stack, if it contains a list it is added to
4709 	    // list_stack.
4710 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4711 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4712 						       ht_stack, &list_stack);
4713 	if (list_stack == NULL)
4714 	    break;
4715 
4716 	// take an item from the stack
4717 	cur_l = list_stack->list;
4718 	tempitem = list_stack;
4719 	list_stack = list_stack->prev;
4720 	free(tempitem);
4721     }
4722 
4723     return abort;
4724 }
4725 
4726 /*
4727  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4728  * "list_stack" is used to add lists to be marked.  Can be NULL.
4729  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4730  *
4731  * Returns TRUE if setting references failed somehow.
4732  */
4733     int
4734 set_ref_in_item(
4735     typval_T	    *tv,
4736     int		    copyID,
4737     ht_stack_T	    **ht_stack,
4738     list_stack_T    **list_stack)
4739 {
4740     int		abort = FALSE;
4741 
4742     if (tv->v_type == VAR_DICT)
4743     {
4744 	dict_T	*dd = tv->vval.v_dict;
4745 
4746 	if (dd != NULL && dd->dv_copyID != copyID)
4747 	{
4748 	    // Didn't see this dict yet.
4749 	    dd->dv_copyID = copyID;
4750 	    if (ht_stack == NULL)
4751 	    {
4752 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4753 	    }
4754 	    else
4755 	    {
4756 		ht_stack_T *newitem = ALLOC_ONE(ht_stack_T);
4757 
4758 		if (newitem == NULL)
4759 		    abort = TRUE;
4760 		else
4761 		{
4762 		    newitem->ht = &dd->dv_hashtab;
4763 		    newitem->prev = *ht_stack;
4764 		    *ht_stack = newitem;
4765 		}
4766 	    }
4767 	}
4768     }
4769     else if (tv->v_type == VAR_LIST)
4770     {
4771 	list_T	*ll = tv->vval.v_list;
4772 
4773 	if (ll != NULL && ll->lv_copyID != copyID)
4774 	{
4775 	    // Didn't see this list yet.
4776 	    ll->lv_copyID = copyID;
4777 	    if (list_stack == NULL)
4778 	    {
4779 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4780 	    }
4781 	    else
4782 	    {
4783 		list_stack_T *newitem = ALLOC_ONE(list_stack_T);
4784 
4785 		if (newitem == NULL)
4786 		    abort = TRUE;
4787 		else
4788 		{
4789 		    newitem->list = ll;
4790 		    newitem->prev = *list_stack;
4791 		    *list_stack = newitem;
4792 		}
4793 	    }
4794 	}
4795     }
4796     else if (tv->v_type == VAR_FUNC)
4797     {
4798 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4799     }
4800     else if (tv->v_type == VAR_PARTIAL)
4801     {
4802 	partial_T	*pt = tv->vval.v_partial;
4803 	int		i;
4804 
4805 	if (pt != NULL && pt->pt_copyID != copyID)
4806 	{
4807 	    // Didn't see this partial yet.
4808 	    pt->pt_copyID = copyID;
4809 
4810 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4811 
4812 	    if (pt->pt_dict != NULL)
4813 	    {
4814 		typval_T dtv;
4815 
4816 		dtv.v_type = VAR_DICT;
4817 		dtv.vval.v_dict = pt->pt_dict;
4818 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4819 	    }
4820 
4821 	    for (i = 0; i < pt->pt_argc; ++i)
4822 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4823 							ht_stack, list_stack);
4824 	    if (pt->pt_funcstack != NULL)
4825 	    {
4826 		typval_T    *stack = pt->pt_funcstack->fs_ga.ga_data;
4827 
4828 		for (i = 0; i < pt->pt_funcstack->fs_ga.ga_len; ++i)
4829 		    abort = abort || set_ref_in_item(stack + i, copyID,
4830 							 ht_stack, list_stack);
4831 	    }
4832 
4833 	}
4834     }
4835 #ifdef FEAT_JOB_CHANNEL
4836     else if (tv->v_type == VAR_JOB)
4837     {
4838 	job_T	    *job = tv->vval.v_job;
4839 	typval_T    dtv;
4840 
4841 	if (job != NULL && job->jv_copyID != copyID)
4842 	{
4843 	    job->jv_copyID = copyID;
4844 	    if (job->jv_channel != NULL)
4845 	    {
4846 		dtv.v_type = VAR_CHANNEL;
4847 		dtv.vval.v_channel = job->jv_channel;
4848 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4849 	    }
4850 	    if (job->jv_exit_cb.cb_partial != NULL)
4851 	    {
4852 		dtv.v_type = VAR_PARTIAL;
4853 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4854 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4855 	    }
4856 	}
4857     }
4858     else if (tv->v_type == VAR_CHANNEL)
4859     {
4860 	channel_T   *ch =tv->vval.v_channel;
4861 	ch_part_T   part;
4862 	typval_T    dtv;
4863 	jsonq_T	    *jq;
4864 	cbq_T	    *cq;
4865 
4866 	if (ch != NULL && ch->ch_copyID != copyID)
4867 	{
4868 	    ch->ch_copyID = copyID;
4869 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4870 	    {
4871 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4872 							     jq = jq->jq_next)
4873 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4874 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4875 							     cq = cq->cq_next)
4876 		    if (cq->cq_callback.cb_partial != NULL)
4877 		    {
4878 			dtv.v_type = VAR_PARTIAL;
4879 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4880 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4881 		    }
4882 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4883 		{
4884 		    dtv.v_type = VAR_PARTIAL;
4885 		    dtv.vval.v_partial =
4886 				      ch->ch_part[part].ch_callback.cb_partial;
4887 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4888 		}
4889 	    }
4890 	    if (ch->ch_callback.cb_partial != NULL)
4891 	    {
4892 		dtv.v_type = VAR_PARTIAL;
4893 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4894 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4895 	    }
4896 	    if (ch->ch_close_cb.cb_partial != NULL)
4897 	    {
4898 		dtv.v_type = VAR_PARTIAL;
4899 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4900 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4901 	    }
4902 	}
4903     }
4904 #endif
4905     return abort;
4906 }
4907 
4908 /*
4909  * Return a string with the string representation of a variable.
4910  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4911  * "numbuf" is used for a number.
4912  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4913  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4914  * strings as "string()", otherwise does not put quotes around strings, as
4915  * ":echo" displays values.
4916  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4917  * are replaced with "...".
4918  * May return NULL.
4919  */
4920     char_u *
4921 echo_string_core(
4922     typval_T	*tv,
4923     char_u	**tofree,
4924     char_u	*numbuf,
4925     int		copyID,
4926     int		echo_style,
4927     int		restore_copyID,
4928     int		composite_val)
4929 {
4930     static int	recurse = 0;
4931     char_u	*r = NULL;
4932 
4933     if (recurse >= DICT_MAXNEST)
4934     {
4935 	if (!did_echo_string_emsg)
4936 	{
4937 	    // Only give this message once for a recursive call to avoid
4938 	    // flooding the user with errors.  And stop iterating over lists
4939 	    // and dicts.
4940 	    did_echo_string_emsg = TRUE;
4941 	    emsg(_("E724: variable nested too deep for displaying"));
4942 	}
4943 	*tofree = NULL;
4944 	return (char_u *)"{E724}";
4945     }
4946     ++recurse;
4947 
4948     switch (tv->v_type)
4949     {
4950 	case VAR_STRING:
4951 	    if (echo_style && !composite_val)
4952 	    {
4953 		*tofree = NULL;
4954 		r = tv->vval.v_string;
4955 		if (r == NULL)
4956 		    r = (char_u *)"";
4957 	    }
4958 	    else
4959 	    {
4960 		*tofree = string_quote(tv->vval.v_string, FALSE);
4961 		r = *tofree;
4962 	    }
4963 	    break;
4964 
4965 	case VAR_FUNC:
4966 	    if (echo_style)
4967 	    {
4968 		*tofree = NULL;
4969 		r = tv->vval.v_string;
4970 	    }
4971 	    else
4972 	    {
4973 		*tofree = string_quote(tv->vval.v_string, TRUE);
4974 		r = *tofree;
4975 	    }
4976 	    break;
4977 
4978 	case VAR_PARTIAL:
4979 	    {
4980 		partial_T   *pt = tv->vval.v_partial;
4981 		char_u	    *fname = string_quote(pt == NULL ? NULL
4982 						    : partial_name(pt), FALSE);
4983 		garray_T    ga;
4984 		int	    i;
4985 		char_u	    *tf;
4986 
4987 		ga_init2(&ga, 1, 100);
4988 		ga_concat(&ga, (char_u *)"function(");
4989 		if (fname != NULL)
4990 		{
4991 		    ga_concat(&ga, fname);
4992 		    vim_free(fname);
4993 		}
4994 		if (pt != NULL && pt->pt_argc > 0)
4995 		{
4996 		    ga_concat(&ga, (char_u *)", [");
4997 		    for (i = 0; i < pt->pt_argc; ++i)
4998 		    {
4999 			if (i > 0)
5000 			    ga_concat(&ga, (char_u *)", ");
5001 			ga_concat(&ga,
5002 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
5003 			vim_free(tf);
5004 		    }
5005 		    ga_concat(&ga, (char_u *)"]");
5006 		}
5007 		if (pt != NULL && pt->pt_dict != NULL)
5008 		{
5009 		    typval_T dtv;
5010 
5011 		    ga_concat(&ga, (char_u *)", ");
5012 		    dtv.v_type = VAR_DICT;
5013 		    dtv.vval.v_dict = pt->pt_dict;
5014 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
5015 		    vim_free(tf);
5016 		}
5017 		ga_concat(&ga, (char_u *)")");
5018 
5019 		*tofree = ga.ga_data;
5020 		r = *tofree;
5021 		break;
5022 	    }
5023 
5024 	case VAR_BLOB:
5025 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
5026 	    break;
5027 
5028 	case VAR_LIST:
5029 	    if (tv->vval.v_list == NULL)
5030 	    {
5031 		// NULL list is equivalent to empty list.
5032 		*tofree = NULL;
5033 		r = (char_u *)"[]";
5034 	    }
5035 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
5036 		    && tv->vval.v_list->lv_len > 0)
5037 	    {
5038 		*tofree = NULL;
5039 		r = (char_u *)"[...]";
5040 	    }
5041 	    else
5042 	    {
5043 		int old_copyID = tv->vval.v_list->lv_copyID;
5044 
5045 		tv->vval.v_list->lv_copyID = copyID;
5046 		*tofree = list2string(tv, copyID, restore_copyID);
5047 		if (restore_copyID)
5048 		    tv->vval.v_list->lv_copyID = old_copyID;
5049 		r = *tofree;
5050 	    }
5051 	    break;
5052 
5053 	case VAR_DICT:
5054 	    if (tv->vval.v_dict == NULL)
5055 	    {
5056 		// NULL dict is equivalent to empty dict.
5057 		*tofree = NULL;
5058 		r = (char_u *)"{}";
5059 	    }
5060 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
5061 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
5062 	    {
5063 		*tofree = NULL;
5064 		r = (char_u *)"{...}";
5065 	    }
5066 	    else
5067 	    {
5068 		int old_copyID = tv->vval.v_dict->dv_copyID;
5069 
5070 		tv->vval.v_dict->dv_copyID = copyID;
5071 		*tofree = dict2string(tv, copyID, restore_copyID);
5072 		if (restore_copyID)
5073 		    tv->vval.v_dict->dv_copyID = old_copyID;
5074 		r = *tofree;
5075 	    }
5076 	    break;
5077 
5078 	case VAR_NUMBER:
5079 	case VAR_UNKNOWN:
5080 	case VAR_ANY:
5081 	case VAR_VOID:
5082 	    *tofree = NULL;
5083 	    r = tv_get_string_buf(tv, numbuf);
5084 	    break;
5085 
5086 	case VAR_JOB:
5087 	case VAR_CHANNEL:
5088 #ifdef FEAT_JOB_CHANNEL
5089 	    *tofree = NULL;
5090 	    r = tv->v_type == VAR_JOB ? job_to_string_buf(tv, numbuf)
5091 					   : channel_to_string_buf(tv, numbuf);
5092 	    if (composite_val)
5093 	    {
5094 		*tofree = string_quote(r, FALSE);
5095 		r = *tofree;
5096 	    }
5097 #endif
5098 	    break;
5099 
5100 	case VAR_INSTR:
5101 	    *tofree = NULL;
5102 	    r = (char_u *)"instructions";
5103 	    break;
5104 
5105 	case VAR_FLOAT:
5106 #ifdef FEAT_FLOAT
5107 	    *tofree = NULL;
5108 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
5109 	    r = numbuf;
5110 	    break;
5111 #endif
5112 
5113 	case VAR_BOOL:
5114 	case VAR_SPECIAL:
5115 	    *tofree = NULL;
5116 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
5117 	    break;
5118     }
5119 
5120     if (--recurse == 0)
5121 	did_echo_string_emsg = FALSE;
5122     return r;
5123 }
5124 
5125 /*
5126  * Return a string with the string representation of a variable.
5127  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5128  * "numbuf" is used for a number.
5129  * Does not put quotes around strings, as ":echo" displays values.
5130  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5131  * May return NULL.
5132  */
5133     char_u *
5134 echo_string(
5135     typval_T	*tv,
5136     char_u	**tofree,
5137     char_u	*numbuf,
5138     int		copyID)
5139 {
5140     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
5141 }
5142 
5143 /*
5144  * Convert the specified byte index of line 'lnum' in buffer 'buf' to a
5145  * character index.  Works only for loaded buffers. Returns -1 on failure.
5146  * The index of the first byte and the first character is zero.
5147  */
5148     int
5149 buf_byteidx_to_charidx(buf_T *buf, int lnum, int byteidx)
5150 {
5151     char_u	*str;
5152     char_u	*t;
5153     int		count;
5154 
5155     if (buf == NULL || buf->b_ml.ml_mfp == NULL)
5156 	return -1;
5157 
5158     if (lnum > buf->b_ml.ml_line_count)
5159 	lnum = buf->b_ml.ml_line_count;
5160 
5161     str = ml_get_buf(buf, lnum, FALSE);
5162     if (str == NULL)
5163 	return -1;
5164 
5165     if (*str == NUL)
5166 	return 0;
5167 
5168     // count the number of characters
5169     t = str;
5170     for (count = 0; *t != NUL && t <= str + byteidx; count++)
5171 	t += mb_ptr2len(t);
5172 
5173     // In insert mode, when the cursor is at the end of a non-empty line,
5174     // byteidx points to the NUL character immediately past the end of the
5175     // string. In this case, add one to the character count.
5176     if (*t == NUL && byteidx != 0 && t == str + byteidx)
5177 	count++;
5178 
5179     return count - 1;
5180 }
5181 
5182 /*
5183  * Convert the specified character index of line 'lnum' in buffer 'buf' to a
5184  * byte index.  Works only for loaded buffers. Returns -1 on failure.
5185  * The index of the first byte and the first character is zero.
5186  */
5187     int
5188 buf_charidx_to_byteidx(buf_T *buf, int lnum, int charidx)
5189 {
5190     char_u	*str;
5191     char_u	*t;
5192 
5193     if (buf == NULL || buf->b_ml.ml_mfp == NULL)
5194 	return -1;
5195 
5196     if (lnum > buf->b_ml.ml_line_count)
5197 	lnum = buf->b_ml.ml_line_count;
5198 
5199     str = ml_get_buf(buf, lnum, FALSE);
5200     if (str == NULL)
5201 	return -1;
5202 
5203     // Convert the character offset to a byte offset
5204     t = str;
5205     while (*t != NUL && --charidx > 0)
5206 	t += mb_ptr2len(t);
5207 
5208     return t - str;
5209 }
5210 
5211 /*
5212  * Translate a String variable into a position.
5213  * Returns NULL when there is an error.
5214  */
5215     pos_T *
5216 var2fpos(
5217     typval_T	*varp,
5218     int		dollar_lnum,	// TRUE when $ is last line
5219     int		*fnum,		// set to fnum for '0, 'A, etc.
5220     int		charcol)	// return character column
5221 {
5222     char_u		*name;
5223     static pos_T	pos;
5224     pos_T		*pp;
5225 
5226     // Argument can be [lnum, col, coladd].
5227     if (varp->v_type == VAR_LIST)
5228     {
5229 	list_T		*l;
5230 	int		len;
5231 	int		error = FALSE;
5232 	listitem_T	*li;
5233 
5234 	l = varp->vval.v_list;
5235 	if (l == NULL)
5236 	    return NULL;
5237 
5238 	// Get the line number
5239 	pos.lnum = list_find_nr(l, 0L, &error);
5240 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
5241 	    return NULL;	// invalid line number
5242 	if (charcol)
5243 	    len = (long)mb_charlen(ml_get(pos.lnum));
5244 	else
5245 	    len = (long)STRLEN(ml_get(pos.lnum));
5246 
5247 	// Get the column number
5248 	// We accept "$" for the column number: last column.
5249 	li = list_find(l, 1L);
5250 	if (li != NULL && li->li_tv.v_type == VAR_STRING
5251 		&& li->li_tv.vval.v_string != NULL
5252 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
5253 	{
5254 	    pos.col = len + 1;
5255 	}
5256 	else
5257 	{
5258 	    pos.col = list_find_nr(l, 1L, &error);
5259 	    if (error)
5260 		return NULL;
5261 	}
5262 
5263 	// Accept a position up to the NUL after the line.
5264 	if (pos.col == 0 || (int)pos.col > len + 1)
5265 	    return NULL;	// invalid column number
5266 	--pos.col;
5267 
5268 	// Get the virtual offset.  Defaults to zero.
5269 	pos.coladd = list_find_nr(l, 2L, &error);
5270 	if (error)
5271 	    pos.coladd = 0;
5272 
5273 	return &pos;
5274     }
5275 
5276     if (in_vim9script() && check_for_string_arg(varp, 0) == FAIL)
5277 	return NULL;
5278 
5279     name = tv_get_string_chk(varp);
5280     if (name == NULL)
5281 	return NULL;
5282     if (name[0] == '.')				// cursor
5283     {
5284 	pos = curwin->w_cursor;
5285 	if (charcol)
5286 	    pos.col = buf_byteidx_to_charidx(curbuf, pos.lnum, pos.col);
5287 	return &pos;
5288     }
5289     if (name[0] == 'v' && name[1] == NUL)	// Visual start
5290     {
5291 	if (VIsual_active)
5292 	    pos = VIsual;
5293 	else
5294 	    pos = curwin->w_cursor;
5295 	if (charcol)
5296 	    pos.col = buf_byteidx_to_charidx(curbuf, pos.lnum, pos.col);
5297 	return &pos;
5298     }
5299     if (name[0] == '\'')			// mark
5300     {
5301 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
5302 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
5303 	    return NULL;
5304 	if (charcol)
5305 	    pp->col = buf_byteidx_to_charidx(curbuf, pp->lnum, pp->col);
5306 	return pp;
5307     }
5308 
5309     pos.coladd = 0;
5310 
5311     if (name[0] == 'w' && dollar_lnum)
5312     {
5313 	pos.col = 0;
5314 	if (name[1] == '0')		// "w0": first visible line
5315 	{
5316 	    update_topline();
5317 	    // In silent Ex mode topline is zero, but that's not a valid line
5318 	    // number; use one instead.
5319 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
5320 	    return &pos;
5321 	}
5322 	else if (name[1] == '$')	// "w$": last visible line
5323 	{
5324 	    validate_botline();
5325 	    // In silent Ex mode botline is zero, return zero then.
5326 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
5327 	    return &pos;
5328 	}
5329     }
5330     else if (name[0] == '$')		// last column or line
5331     {
5332 	if (dollar_lnum)
5333 	{
5334 	    pos.lnum = curbuf->b_ml.ml_line_count;
5335 	    pos.col = 0;
5336 	}
5337 	else
5338 	{
5339 	    pos.lnum = curwin->w_cursor.lnum;
5340 	    if (charcol)
5341 		pos.col = (colnr_T)mb_charlen(ml_get_curline());
5342 	    else
5343 		pos.col = (colnr_T)STRLEN(ml_get_curline());
5344 	}
5345 	return &pos;
5346     }
5347     if (in_vim9script())
5348 	semsg(_(e_invalid_value_for_line_number_str), name);
5349     return NULL;
5350 }
5351 
5352 /*
5353  * Convert list in "arg" into a position and optional file number.
5354  * When "fnump" is NULL there is no file number, only 3 items.
5355  * Note that the column is passed on as-is, the caller may want to decrement
5356  * it to use 1 for the first column.
5357  * Return FAIL when conversion is not possible, doesn't check the position for
5358  * validity.
5359  */
5360     int
5361 list2fpos(
5362     typval_T	*arg,
5363     pos_T	*posp,
5364     int		*fnump,
5365     colnr_T	*curswantp,
5366     int		charcol)
5367 {
5368     list_T	*l = arg->vval.v_list;
5369     long	i = 0;
5370     long	n;
5371 
5372     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
5373     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
5374     if (arg->v_type != VAR_LIST
5375 	    || l == NULL
5376 	    || l->lv_len < (fnump == NULL ? 2 : 3)
5377 	    || l->lv_len > (fnump == NULL ? 4 : 5))
5378 	return FAIL;
5379 
5380     if (fnump != NULL)
5381     {
5382 	n = list_find_nr(l, i++, NULL);	// fnum
5383 	if (n < 0)
5384 	    return FAIL;
5385 	if (n == 0)
5386 	    n = curbuf->b_fnum;		// current buffer
5387 	*fnump = n;
5388     }
5389 
5390     n = list_find_nr(l, i++, NULL);	// lnum
5391     if (n < 0)
5392 	return FAIL;
5393     posp->lnum = n;
5394 
5395     n = list_find_nr(l, i++, NULL);	// col
5396     if (n < 0)
5397 	return FAIL;
5398     // If character position is specified, then convert to byte position
5399     if (charcol)
5400     {
5401 	buf_T	*buf;
5402 
5403 	// Get the text for the specified line in a loaded buffer
5404 	buf = buflist_findnr(fnump == NULL ? curbuf->b_fnum : *fnump);
5405 	if (buf == NULL || buf->b_ml.ml_mfp == NULL)
5406 	    return FAIL;
5407 
5408 	n = buf_charidx_to_byteidx(buf, posp->lnum, n) + 1;
5409     }
5410     posp->col = n;
5411 
5412     n = list_find_nr(l, i, NULL);	// off
5413     if (n < 0)
5414 	posp->coladd = 0;
5415     else
5416 	posp->coladd = n;
5417 
5418     if (curswantp != NULL)
5419 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
5420 
5421     return OK;
5422 }
5423 
5424 /*
5425  * Get the length of an environment variable name.
5426  * Advance "arg" to the first character after the name.
5427  * Return 0 for error.
5428  */
5429     int
5430 get_env_len(char_u **arg)
5431 {
5432     char_u	*p;
5433     int		len;
5434 
5435     for (p = *arg; vim_isIDc(*p); ++p)
5436 	;
5437     if (p == *arg)	    // no name found
5438 	return 0;
5439 
5440     len = (int)(p - *arg);
5441     *arg = p;
5442     return len;
5443 }
5444 
5445 /*
5446  * Get the length of the name of a function or internal variable.
5447  * "arg" is advanced to after the name.
5448  * Return 0 if something is wrong.
5449  */
5450     int
5451 get_id_len(char_u **arg)
5452 {
5453     char_u	*p;
5454     int		len;
5455 
5456     // Find the end of the name.
5457     for (p = *arg; eval_isnamec(*p); ++p)
5458     {
5459 	if (*p == ':')
5460 	{
5461 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5462 	    // slice "[n:]".  Also "xx:" is not a namespace.
5463 	    len = (int)(p - *arg);
5464 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
5465 		    || len > 1)
5466 		break;
5467 	}
5468     }
5469     if (p == *arg)	    // no name found
5470 	return 0;
5471 
5472     len = (int)(p - *arg);
5473     *arg = p;
5474 
5475     return len;
5476 }
5477 
5478 /*
5479  * Get the length of the name of a variable or function.
5480  * Only the name is recognized, does not handle ".key" or "[idx]".
5481  * "arg" is advanced to the first non-white character after the name.
5482  * Return -1 if curly braces expansion failed.
5483  * Return 0 if something else is wrong.
5484  * If the name contains 'magic' {}'s, expand them and return the
5485  * expanded name in an allocated string via 'alias' - caller must free.
5486  */
5487     int
5488 get_name_len(
5489     char_u	**arg,
5490     char_u	**alias,
5491     int		evaluate,
5492     int		verbose)
5493 {
5494     int		len;
5495     char_u	*p;
5496     char_u	*expr_start;
5497     char_u	*expr_end;
5498 
5499     *alias = NULL;  // default to no alias
5500 
5501     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
5502 						  && (*arg)[2] == (int)KE_SNR)
5503     {
5504 	// hard coded <SNR>, already translated
5505 	*arg += 3;
5506 	return get_id_len(arg) + 3;
5507     }
5508     len = eval_fname_script(*arg);
5509     if (len > 0)
5510     {
5511 	// literal "<SID>", "s:" or "<SNR>"
5512 	*arg += len;
5513     }
5514 
5515     /*
5516      * Find the end of the name; check for {} construction.
5517      */
5518     p = find_name_end(*arg, &expr_start, &expr_end,
5519 					       len > 0 ? 0 : FNE_CHECK_START);
5520     if (expr_start != NULL)
5521     {
5522 	char_u	*temp_string;
5523 
5524 	if (!evaluate)
5525 	{
5526 	    len += (int)(p - *arg);
5527 	    *arg = skipwhite(p);
5528 	    return len;
5529 	}
5530 
5531 	/*
5532 	 * Include any <SID> etc in the expanded string:
5533 	 * Thus the -len here.
5534 	 */
5535 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
5536 	if (temp_string == NULL)
5537 	    return -1;
5538 	*alias = temp_string;
5539 	*arg = skipwhite(p);
5540 	return (int)STRLEN(temp_string);
5541     }
5542 
5543     len += get_id_len(arg);
5544     // Only give an error when there is something, otherwise it will be
5545     // reported at a higher level.
5546     if (len == 0 && verbose && **arg != NUL)
5547 	semsg(_(e_invalid_expression_str), *arg);
5548 
5549     return len;
5550 }
5551 
5552 /*
5553  * Find the end of a variable or function name, taking care of magic braces.
5554  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
5555  * start and end of the first magic braces item.
5556  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
5557  * Return a pointer to just after the name.  Equal to "arg" if there is no
5558  * valid name.
5559  */
5560     char_u *
5561 find_name_end(
5562     char_u	*arg,
5563     char_u	**expr_start,
5564     char_u	**expr_end,
5565     int		flags)
5566 {
5567     int		mb_nest = 0;
5568     int		br_nest = 0;
5569     char_u	*p;
5570     int		len;
5571     int		vim9script = in_vim9script();
5572 
5573     if (expr_start != NULL)
5574     {
5575 	*expr_start = NULL;
5576 	*expr_end = NULL;
5577     }
5578 
5579     // Quick check for valid starting character.
5580     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg)
5581 						&& (*arg != '{' || vim9script))
5582 	return arg;
5583 
5584     for (p = arg; *p != NUL
5585 		    && (eval_isnamec(*p)
5586 			|| (*p == '{' && !vim9script)
5587 			|| ((flags & FNE_INCL_BR) && (*p == '['
5588 					 || (*p == '.' && eval_isdictc(p[1]))))
5589 			|| mb_nest != 0
5590 			|| br_nest != 0); MB_PTR_ADV(p))
5591     {
5592 	if (*p == '\'')
5593 	{
5594 	    // skip over 'string' to avoid counting [ and ] inside it.
5595 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5596 		;
5597 	    if (*p == NUL)
5598 		break;
5599 	}
5600 	else if (*p == '"')
5601 	{
5602 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
5603 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5604 		if (*p == '\\' && p[1] != NUL)
5605 		    ++p;
5606 	    if (*p == NUL)
5607 		break;
5608 	}
5609 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5610 	{
5611 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5612 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
5613 	    len = (int)(p - arg);
5614 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5615 		    || (len > 1 && p[-1] != '}'))
5616 		break;
5617 	}
5618 
5619 	if (mb_nest == 0)
5620 	{
5621 	    if (*p == '[')
5622 		++br_nest;
5623 	    else if (*p == ']')
5624 		--br_nest;
5625 	}
5626 
5627 	if (br_nest == 0 && !vim9script)
5628 	{
5629 	    if (*p == '{')
5630 	    {
5631 		mb_nest++;
5632 		if (expr_start != NULL && *expr_start == NULL)
5633 		    *expr_start = p;
5634 	    }
5635 	    else if (*p == '}')
5636 	    {
5637 		mb_nest--;
5638 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5639 		    *expr_end = p;
5640 	    }
5641 	}
5642     }
5643 
5644     return p;
5645 }
5646 
5647 /*
5648  * Expands out the 'magic' {}'s in a variable/function name.
5649  * Note that this can call itself recursively, to deal with
5650  * constructs like foo{bar}{baz}{bam}
5651  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5652  *			"in_start"      ^
5653  *			"expr_start"	   ^
5654  *			"expr_end"		 ^
5655  *			"in_end"			    ^
5656  *
5657  * Returns a new allocated string, which the caller must free.
5658  * Returns NULL for failure.
5659  */
5660     static char_u *
5661 make_expanded_name(
5662     char_u	*in_start,
5663     char_u	*expr_start,
5664     char_u	*expr_end,
5665     char_u	*in_end)
5666 {
5667     char_u	c1;
5668     char_u	*retval = NULL;
5669     char_u	*temp_result;
5670 
5671     if (expr_end == NULL || in_end == NULL)
5672 	return NULL;
5673     *expr_start	= NUL;
5674     *expr_end = NUL;
5675     c1 = *in_end;
5676     *in_end = NUL;
5677 
5678     temp_result = eval_to_string(expr_start + 1, FALSE);
5679     if (temp_result != NULL)
5680     {
5681 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5682 						   + (in_end - expr_end) + 1);
5683 	if (retval != NULL)
5684 	{
5685 	    STRCPY(retval, in_start);
5686 	    STRCAT(retval, temp_result);
5687 	    STRCAT(retval, expr_end + 1);
5688 	}
5689     }
5690     vim_free(temp_result);
5691 
5692     *in_end = c1;		// put char back for error messages
5693     *expr_start = '{';
5694     *expr_end = '}';
5695 
5696     if (retval != NULL)
5697     {
5698 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5699 	if (expr_start != NULL)
5700 	{
5701 	    // Further expansion!
5702 	    temp_result = make_expanded_name(retval, expr_start,
5703 						       expr_end, temp_result);
5704 	    vim_free(retval);
5705 	    retval = temp_result;
5706 	}
5707     }
5708 
5709     return retval;
5710 }
5711 
5712 /*
5713  * Return TRUE if character "c" can be used in a variable or function name.
5714  * Does not include '{' or '}' for magic braces.
5715  */
5716     int
5717 eval_isnamec(int c)
5718 {
5719     return ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR;
5720 }
5721 
5722 /*
5723  * Return TRUE if character "c" can be used as the first character in a
5724  * variable or function name (excluding '{' and '}').
5725  */
5726     int
5727 eval_isnamec1(int c)
5728 {
5729     return ASCII_ISALPHA(c) || c == '_';
5730 }
5731 
5732 /*
5733  * Return TRUE if character "c" can be used as the first character of a
5734  * dictionary key.
5735  */
5736     int
5737 eval_isdictc(int c)
5738 {
5739     return ASCII_ISALNUM(c) || c == '_';
5740 }
5741 
5742 /*
5743  * Handle:
5744  * - expr[expr], expr[expr:expr] subscript
5745  * - ".name" lookup
5746  * - function call with Funcref variable: func(expr)
5747  * - method call: var->method()
5748  *
5749  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5750  */
5751     int
5752 handle_subscript(
5753     char_u	**arg,
5754     typval_T	*rettv,
5755     evalarg_T	*evalarg,
5756     int		verbose)	// give error messages
5757 {
5758     int		evaluate = evalarg != NULL
5759 				      && (evalarg->eval_flags & EVAL_EVALUATE);
5760     int		ret = OK;
5761     dict_T	*selfdict = NULL;
5762     int		check_white = TRUE;
5763     int		getnext;
5764     char_u	*p;
5765 
5766     while (ret == OK)
5767     {
5768 	// When at the end of the line and ".name" or "->{" or "->X" follows in
5769 	// the next line then consume the line break.
5770 	p = eval_next_non_blank(*arg, evalarg, &getnext);
5771 	if (getnext
5772 	    && ((rettv->v_type == VAR_DICT && *p == '.' && eval_isdictc(p[1]))
5773 		|| (p[0] == '-' && p[1] == '>' && (p[2] == '{'
5774 			|| ASCII_ISALPHA(in_vim9script() ? *skipwhite(p + 2)
5775 								    : p[2])))))
5776 	{
5777 	    *arg = eval_next_line(evalarg);
5778 	    p = *arg;
5779 	    check_white = FALSE;
5780 	}
5781 
5782 	if (rettv->v_type == VAR_ANY)
5783 	{
5784 	    char_u	*exp_name;
5785 	    int		cc;
5786 	    int		idx;
5787 	    ufunc_T	*ufunc;
5788 	    type_T	*type;
5789 
5790 	    // Found script from "import * as {name}", script item name must
5791 	    // follow.
5792 	    if (**arg != '.')
5793 	    {
5794 		if (verbose)
5795 		    semsg(_(e_expected_str_but_got_str), "'.'", *arg);
5796 		ret = FAIL;
5797 		break;
5798 	    }
5799 	    ++*arg;
5800 	    if (IS_WHITE_OR_NUL(**arg))
5801 	    {
5802 		if (verbose)
5803 		    emsg(_(e_no_white_space_allowed_after_dot));
5804 		ret = FAIL;
5805 		break;
5806 	    }
5807 
5808 	    // isolate the name
5809 	    exp_name = *arg;
5810 	    while (eval_isnamec(**arg))
5811 		++*arg;
5812 	    cc = **arg;
5813 	    **arg = NUL;
5814 
5815 	    idx = find_exported(rettv->vval.v_number, exp_name, &ufunc, &type,
5816 						  evalarg->eval_cctx, verbose);
5817 	    **arg = cc;
5818 	    *arg = skipwhite(*arg);
5819 
5820 	    if (idx < 0 && ufunc == NULL)
5821 	    {
5822 		ret = FAIL;
5823 		break;
5824 	    }
5825 	    if (idx >= 0)
5826 	    {
5827 		scriptitem_T    *si = SCRIPT_ITEM(rettv->vval.v_number);
5828 		svar_T		*sv = ((svar_T *)si->sn_var_vals.ga_data) + idx;
5829 
5830 		copy_tv(sv->sv_tv, rettv);
5831 	    }
5832 	    else
5833 	    {
5834 		rettv->v_type = VAR_FUNC;
5835 		rettv->vval.v_string = vim_strsave(ufunc->uf_name);
5836 	    }
5837 	}
5838 
5839 	if ((**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5840 			    || rettv->v_type == VAR_PARTIAL))
5841 		    && (!check_white || !VIM_ISWHITE(*(*arg - 1))))
5842 	{
5843 	    ret = call_func_rettv(arg, evalarg, rettv, evaluate,
5844 							       selfdict, NULL);
5845 
5846 	    // Stop the expression evaluation when immediately aborting on
5847 	    // error, or when an interrupt occurred or an exception was thrown
5848 	    // but not caught.
5849 	    if (aborting())
5850 	    {
5851 		if (ret == OK)
5852 		    clear_tv(rettv);
5853 		ret = FAIL;
5854 	    }
5855 	    dict_unref(selfdict);
5856 	    selfdict = NULL;
5857 	}
5858 	else if (p[0] == '-' && p[1] == '>')
5859 	{
5860 	    if (in_vim9script())
5861 		*arg = skipwhite(p + 2);
5862 	    else
5863 		*arg = p + 2;
5864 	    if (ret == OK)
5865 	    {
5866 		if (VIM_ISWHITE(**arg))
5867 		{
5868 		    emsg(_(e_nowhitespace));
5869 		    ret = FAIL;
5870 		}
5871 		else if ((**arg == '{' && !in_vim9script()) || **arg == '(')
5872 		    // expr->{lambda}() or expr->(lambda)()
5873 		    ret = eval_lambda(arg, rettv, evalarg, verbose);
5874 		else
5875 		    // expr->name()
5876 		    ret = eval_method(arg, rettv, evalarg, verbose);
5877 	    }
5878 	}
5879 	// "." is ".name" lookup when we found a dict or when evaluating and
5880 	// scriptversion is at least 2, where string concatenation is "..".
5881 	else if (**arg == '['
5882 		|| (**arg == '.' && (rettv->v_type == VAR_DICT
5883 			|| (!evaluate
5884 			    && (*arg)[1] != '.'
5885 			    && !in_old_script(2)))))
5886 	{
5887 	    dict_unref(selfdict);
5888 	    if (rettv->v_type == VAR_DICT)
5889 	    {
5890 		selfdict = rettv->vval.v_dict;
5891 		if (selfdict != NULL)
5892 		    ++selfdict->dv_refcount;
5893 	    }
5894 	    else
5895 		selfdict = NULL;
5896 	    if (eval_index(arg, rettv, evalarg, verbose) == FAIL)
5897 	    {
5898 		clear_tv(rettv);
5899 		ret = FAIL;
5900 	    }
5901 	}
5902 	else
5903 	    break;
5904     }
5905 
5906     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5907     // Don't do this when "Func" is already a partial that was bound
5908     // explicitly (pt_auto is FALSE).
5909     if (selfdict != NULL
5910 	    && (rettv->v_type == VAR_FUNC
5911 		|| (rettv->v_type == VAR_PARTIAL
5912 		    && (rettv->vval.v_partial->pt_auto
5913 			|| rettv->vval.v_partial->pt_dict == NULL))))
5914 	selfdict = make_partial(selfdict, rettv);
5915 
5916     dict_unref(selfdict);
5917     return ret;
5918 }
5919 
5920 /*
5921  * Make a copy of an item.
5922  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5923  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5924  * reference to an already copied list/dict can be used.
5925  * Returns FAIL or OK.
5926  */
5927     int
5928 item_copy(
5929     typval_T	*from,
5930     typval_T	*to,
5931     int		deep,
5932     int		copyID)
5933 {
5934     static int	recurse = 0;
5935     int		ret = OK;
5936 
5937     if (recurse >= DICT_MAXNEST)
5938     {
5939 	emsg(_("E698: variable nested too deep for making a copy"));
5940 	return FAIL;
5941     }
5942     ++recurse;
5943 
5944     switch (from->v_type)
5945     {
5946 	case VAR_NUMBER:
5947 	case VAR_FLOAT:
5948 	case VAR_STRING:
5949 	case VAR_FUNC:
5950 	case VAR_PARTIAL:
5951 	case VAR_BOOL:
5952 	case VAR_SPECIAL:
5953 	case VAR_JOB:
5954 	case VAR_CHANNEL:
5955 	case VAR_INSTR:
5956 	    copy_tv(from, to);
5957 	    break;
5958 	case VAR_LIST:
5959 	    to->v_type = VAR_LIST;
5960 	    to->v_lock = 0;
5961 	    if (from->vval.v_list == NULL)
5962 		to->vval.v_list = NULL;
5963 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
5964 	    {
5965 		// use the copy made earlier
5966 		to->vval.v_list = from->vval.v_list->lv_copylist;
5967 		++to->vval.v_list->lv_refcount;
5968 	    }
5969 	    else
5970 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
5971 	    if (to->vval.v_list == NULL)
5972 		ret = FAIL;
5973 	    break;
5974 	case VAR_BLOB:
5975 	    ret = blob_copy(from->vval.v_blob, to);
5976 	    break;
5977 	case VAR_DICT:
5978 	    to->v_type = VAR_DICT;
5979 	    to->v_lock = 0;
5980 	    if (from->vval.v_dict == NULL)
5981 		to->vval.v_dict = NULL;
5982 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
5983 	    {
5984 		// use the copy made earlier
5985 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
5986 		++to->vval.v_dict->dv_refcount;
5987 	    }
5988 	    else
5989 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
5990 	    if (to->vval.v_dict == NULL)
5991 		ret = FAIL;
5992 	    break;
5993 	case VAR_UNKNOWN:
5994 	case VAR_ANY:
5995 	case VAR_VOID:
5996 	    internal_error_no_abort("item_copy(UNKNOWN)");
5997 	    ret = FAIL;
5998     }
5999     --recurse;
6000     return ret;
6001 }
6002 
6003     void
6004 echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr)
6005 {
6006     char_u	*tofree;
6007     char_u	numbuf[NUMBUFLEN];
6008     char_u	*p = echo_string(rettv, &tofree, numbuf, get_copyID());
6009 
6010     if (*atstart)
6011     {
6012 	*atstart = FALSE;
6013 	// Call msg_start() after eval1(), evaluating the expression
6014 	// may cause a message to appear.
6015 	if (with_space)
6016 	{
6017 	    // Mark the saved text as finishing the line, so that what
6018 	    // follows is displayed on a new line when scrolling back
6019 	    // at the more prompt.
6020 	    msg_sb_eol();
6021 	    msg_start();
6022 	}
6023     }
6024     else if (with_space)
6025 	msg_puts_attr(" ", echo_attr);
6026 
6027     if (p != NULL)
6028 	for ( ; *p != NUL && !got_int; ++p)
6029 	{
6030 	    if (*p == '\n' || *p == '\r' || *p == TAB)
6031 	    {
6032 		if (*p != TAB && *needclr)
6033 		{
6034 		    // remove any text still there from the command
6035 		    msg_clr_eos();
6036 		    *needclr = FALSE;
6037 		}
6038 		msg_putchar_attr(*p, echo_attr);
6039 	    }
6040 	    else
6041 	    {
6042 		if (has_mbyte)
6043 		{
6044 		    int i = (*mb_ptr2len)(p);
6045 
6046 		    (void)msg_outtrans_len_attr(p, i, echo_attr);
6047 		    p += i - 1;
6048 		}
6049 		else
6050 		    (void)msg_outtrans_len_attr(p, 1, echo_attr);
6051 	    }
6052 	}
6053     vim_free(tofree);
6054 }
6055 
6056 /*
6057  * ":echo expr1 ..."	print each argument separated with a space, add a
6058  *			newline at the end.
6059  * ":echon expr1 ..."	print each argument plain.
6060  */
6061     void
6062 ex_echo(exarg_T *eap)
6063 {
6064     char_u	*arg = eap->arg;
6065     typval_T	rettv;
6066     char_u	*arg_start;
6067     int		needclr = TRUE;
6068     int		atstart = TRUE;
6069     int		did_emsg_before = did_emsg;
6070     int		called_emsg_before = called_emsg;
6071     evalarg_T	evalarg;
6072 
6073     fill_evalarg_from_eap(&evalarg, eap, eap->skip);
6074 
6075     if (eap->skip)
6076 	++emsg_skip;
6077     while ((!ends_excmd2(eap->cmd, arg) || *arg == '"') && !got_int)
6078     {
6079 	// If eval1() causes an error message the text from the command may
6080 	// still need to be cleared. E.g., "echo 22,44".
6081 	need_clr_eos = needclr;
6082 
6083 	arg_start = arg;
6084 	if (eval1(&arg, &rettv, &evalarg) == FAIL)
6085 	{
6086 	    /*
6087 	     * Report the invalid expression unless the expression evaluation
6088 	     * has been cancelled due to an aborting error, an interrupt, or an
6089 	     * exception.
6090 	     */
6091 	    if (!aborting() && did_emsg == did_emsg_before
6092 					  && called_emsg == called_emsg_before)
6093 		semsg(_(e_invalid_expression_str), arg_start);
6094 	    need_clr_eos = FALSE;
6095 	    break;
6096 	}
6097 	need_clr_eos = FALSE;
6098 
6099 	if (!eap->skip)
6100 	{
6101 	    if (rettv.v_type == VAR_VOID)
6102 	    {
6103 		semsg(_(e_expression_does_not_result_in_value_str), arg_start);
6104 		break;
6105 	    }
6106 	    echo_one(&rettv, eap->cmdidx == CMD_echo, &atstart, &needclr);
6107 	}
6108 
6109 	clear_tv(&rettv);
6110 	arg = skipwhite(arg);
6111     }
6112     set_nextcmd(eap, arg);
6113     clear_evalarg(&evalarg, eap);
6114 
6115     if (eap->skip)
6116 	--emsg_skip;
6117     else
6118     {
6119 	// remove text that may still be there from the command
6120 	if (needclr)
6121 	    msg_clr_eos();
6122 	if (eap->cmdidx == CMD_echo)
6123 	    msg_end();
6124     }
6125 }
6126 
6127 /*
6128  * ":echohl {name}".
6129  */
6130     void
6131 ex_echohl(exarg_T *eap)
6132 {
6133     echo_attr = syn_name2attr(eap->arg);
6134 }
6135 
6136 /*
6137  * Returns the :echo attribute
6138  */
6139     int
6140 get_echo_attr(void)
6141 {
6142     return echo_attr;
6143 }
6144 
6145 /*
6146  * ":execute expr1 ..."	execute the result of an expression.
6147  * ":echomsg expr1 ..."	Print a message
6148  * ":echoerr expr1 ..."	Print an error
6149  * ":echoconsole expr1 ..." Print a message on stdout
6150  * Each gets spaces around each argument and a newline at the end for
6151  * echo commands
6152  */
6153     void
6154 ex_execute(exarg_T *eap)
6155 {
6156     char_u	*arg = eap->arg;
6157     typval_T	rettv;
6158     int		ret = OK;
6159     char_u	*p;
6160     garray_T	ga;
6161     int		len;
6162     long	start_lnum = SOURCING_LNUM;
6163 
6164     ga_init2(&ga, 1, 80);
6165 
6166     if (eap->skip)
6167 	++emsg_skip;
6168     while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
6169     {
6170 	ret = eval1_emsg(&arg, &rettv, eap);
6171 	if (ret == FAIL)
6172 	    break;
6173 
6174 	if (!eap->skip)
6175 	{
6176 	    char_u   buf[NUMBUFLEN];
6177 
6178 	    if (eap->cmdidx == CMD_execute)
6179 	    {
6180 		if (rettv.v_type == VAR_CHANNEL || rettv.v_type == VAR_JOB)
6181 		{
6182 		    semsg(_(e_using_invalid_value_as_string_str),
6183 						  vartype_name(rettv.v_type));
6184 		    p = NULL;
6185 		}
6186 		else
6187 		    p = tv_get_string_buf(&rettv, buf);
6188 	    }
6189 	    else
6190 		p = tv_stringify(&rettv, buf);
6191 	    if (p == NULL)
6192 	    {
6193 		clear_tv(&rettv);
6194 		ret = FAIL;
6195 		break;
6196 	    }
6197 	    len = (int)STRLEN(p);
6198 	    if (ga_grow(&ga, len + 2) == FAIL)
6199 	    {
6200 		clear_tv(&rettv);
6201 		ret = FAIL;
6202 		break;
6203 	    }
6204 	    if (ga.ga_len)
6205 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
6206 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
6207 	    ga.ga_len += len;
6208 	}
6209 
6210 	clear_tv(&rettv);
6211 	arg = skipwhite(arg);
6212     }
6213 
6214     if (ret != FAIL && ga.ga_data != NULL)
6215     {
6216 	// use the first line of continuation lines for messages
6217 	SOURCING_LNUM = start_lnum;
6218 
6219 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
6220 	{
6221 	    // Mark the already saved text as finishing the line, so that what
6222 	    // follows is displayed on a new line when scrolling back at the
6223 	    // more prompt.
6224 	    msg_sb_eol();
6225 	}
6226 
6227 	if (eap->cmdidx == CMD_echomsg)
6228 	{
6229 	    msg_attr(ga.ga_data, echo_attr);
6230 	    out_flush();
6231 	}
6232 	else if (eap->cmdidx == CMD_echoconsole)
6233 	{
6234 	    ui_write(ga.ga_data, (int)STRLEN(ga.ga_data), TRUE);
6235 	    ui_write((char_u *)"\r\n", 2, TRUE);
6236 	}
6237 	else if (eap->cmdidx == CMD_echoerr)
6238 	{
6239 	    int		save_did_emsg = did_emsg;
6240 
6241 	    // We don't want to abort following commands, restore did_emsg.
6242 	    emsg(ga.ga_data);
6243 	    if (!force_abort)
6244 		did_emsg = save_did_emsg;
6245 	}
6246 	else if (eap->cmdidx == CMD_execute)
6247 	    do_cmdline((char_u *)ga.ga_data,
6248 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
6249     }
6250 
6251     ga_clear(&ga);
6252 
6253     if (eap->skip)
6254 	--emsg_skip;
6255 
6256     set_nextcmd(eap, arg);
6257 }
6258 
6259 /*
6260  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
6261  * "arg" points to the "&" or '+' when called, to "option" when returning.
6262  * Returns NULL when no option name found.  Otherwise pointer to the char
6263  * after the option name.
6264  */
6265     char_u *
6266 find_option_end(char_u **arg, int *opt_flags)
6267 {
6268     char_u	*p = *arg;
6269 
6270     ++p;
6271     if (*p == 'g' && p[1] == ':')
6272     {
6273 	*opt_flags = OPT_GLOBAL;
6274 	p += 2;
6275     }
6276     else if (*p == 'l' && p[1] == ':')
6277     {
6278 	*opt_flags = OPT_LOCAL;
6279 	p += 2;
6280     }
6281     else
6282 	*opt_flags = 0;
6283 
6284     if (!ASCII_ISALPHA(*p))
6285 	return NULL;
6286     *arg = p;
6287 
6288     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
6289 	p += 4;	    // termcap option
6290     else
6291 	while (ASCII_ISALPHA(*p))
6292 	    ++p;
6293     return p;
6294 }
6295 
6296 /*
6297  * Display script name where an item was last set.
6298  * Should only be invoked when 'verbose' is non-zero.
6299  */
6300     void
6301 last_set_msg(sctx_T script_ctx)
6302 {
6303     char_u *p;
6304 
6305     if (script_ctx.sc_sid != 0)
6306     {
6307 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
6308 	if (p != NULL)
6309 	{
6310 	    verbose_enter();
6311 	    msg_puts(_("\n\tLast set from "));
6312 	    msg_puts((char *)p);
6313 	    if (script_ctx.sc_lnum > 0)
6314 	    {
6315 		msg_puts(_(line_msg));
6316 		msg_outnum((long)script_ctx.sc_lnum);
6317 	    }
6318 	    verbose_leave();
6319 	    vim_free(p);
6320 	}
6321     }
6322 }
6323 
6324 #endif // FEAT_EVAL
6325 
6326 /*
6327  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
6328  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
6329  * "flags" can be "g" to do a global substitute.
6330  * Returns an allocated string, NULL for error.
6331  */
6332     char_u *
6333 do_string_sub(
6334     char_u	*str,
6335     char_u	*pat,
6336     char_u	*sub,
6337     typval_T	*expr,
6338     char_u	*flags)
6339 {
6340     int		sublen;
6341     regmatch_T	regmatch;
6342     int		i;
6343     int		do_all;
6344     char_u	*tail;
6345     char_u	*end;
6346     garray_T	ga;
6347     char_u	*ret;
6348     char_u	*save_cpo;
6349     char_u	*zero_width = NULL;
6350 
6351     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
6352     save_cpo = p_cpo;
6353     p_cpo = empty_option;
6354 
6355     ga_init2(&ga, 1, 200);
6356 
6357     do_all = (flags[0] == 'g');
6358 
6359     regmatch.rm_ic = p_ic;
6360     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
6361     if (regmatch.regprog != NULL)
6362     {
6363 	tail = str;
6364 	end = str + STRLEN(str);
6365 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
6366 	{
6367 	    // Skip empty match except for first match.
6368 	    if (regmatch.startp[0] == regmatch.endp[0])
6369 	    {
6370 		if (zero_width == regmatch.startp[0])
6371 		{
6372 		    // avoid getting stuck on a match with an empty string
6373 		    i = mb_ptr2len(tail);
6374 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
6375 								   (size_t)i);
6376 		    ga.ga_len += i;
6377 		    tail += i;
6378 		    continue;
6379 		}
6380 		zero_width = regmatch.startp[0];
6381 	    }
6382 
6383 	    /*
6384 	     * Get some space for a temporary buffer to do the substitution
6385 	     * into.  It will contain:
6386 	     * - The text up to where the match is.
6387 	     * - The substituted text.
6388 	     * - The text after the match.
6389 	     */
6390 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
6391 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
6392 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
6393 	    {
6394 		ga_clear(&ga);
6395 		break;
6396 	    }
6397 
6398 	    // copy the text up to where the match is
6399 	    i = (int)(regmatch.startp[0] - tail);
6400 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
6401 	    // add the substituted text
6402 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
6403 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
6404 	    ga.ga_len += i + sublen - 1;
6405 	    tail = regmatch.endp[0];
6406 	    if (*tail == NUL)
6407 		break;
6408 	    if (!do_all)
6409 		break;
6410 	}
6411 
6412 	if (ga.ga_data != NULL)
6413 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
6414 
6415 	vim_regfree(regmatch.regprog);
6416     }
6417 
6418     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
6419     ga_clear(&ga);
6420     if (p_cpo == empty_option)
6421 	p_cpo = save_cpo;
6422     else
6423     {
6424 	// Darn, evaluating {sub} expression or {expr} changed the value.
6425 	// If it's still empty it was changed and restored, need to restore in
6426 	// the complicated way.
6427 	if (*p_cpo == NUL)
6428 	    set_option_value((char_u *)"cpo", 0L, save_cpo, 0);
6429 	free_string_option(save_cpo);
6430     }
6431 
6432     return ret;
6433 }
6434