xref: /vim-8.2.3635/src/eval.c (revision a7c4e747)
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 } forinfo_T;
45 
46 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
47 static int eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
48 static int eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
49 static int eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
50 static int eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
51 static int eval6(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int want_string);
52 static int eval7(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int want_string);
53 static int eval7_leader(typval_T *rettv, int numeric_only, char_u *start_leader, char_u **end_leaderp);
54 
55 static int free_unref_items(int copyID);
56 static char_u *make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
57 
58 /*
59  * Return "n1" divided by "n2", taking care of dividing by zero.
60  */
61 	varnumber_T
62 num_divide(varnumber_T n1, varnumber_T n2)
63 {
64     varnumber_T	result;
65 
66     if (n2 == 0)	// give an error message?
67     {
68 	if (n1 == 0)
69 	    result = VARNUM_MIN; // similar to NaN
70 	else if (n1 < 0)
71 	    result = -VARNUM_MAX;
72 	else
73 	    result = VARNUM_MAX;
74     }
75     else
76 	result = n1 / n2;
77 
78     return result;
79 }
80 
81 /*
82  * Return "n1" modulus "n2", taking care of dividing by zero.
83  */
84 	varnumber_T
85 num_modulus(varnumber_T n1, varnumber_T n2)
86 {
87     // Give an error when n2 is 0?
88     return (n2 == 0) ? 0 : (n1 % n2);
89 }
90 
91 #if defined(EBCDIC) || defined(PROTO)
92 /*
93  * Compare struct fst by function name.
94  */
95     static int
96 compare_func_name(const void *s1, const void *s2)
97 {
98     struct fst *p1 = (struct fst *)s1;
99     struct fst *p2 = (struct fst *)s2;
100 
101     return STRCMP(p1->f_name, p2->f_name);
102 }
103 
104 /*
105  * Sort the function table by function name.
106  * The sorting of the table above is ASCII dependent.
107  * On machines using EBCDIC we have to sort it.
108  */
109     static void
110 sortFunctions(void)
111 {
112     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
113 
114     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
115 }
116 #endif
117 
118 /*
119  * Initialize the global and v: variables.
120  */
121     void
122 eval_init(void)
123 {
124     evalvars_init();
125     func_init();
126 
127 #ifdef EBCDIC
128     /*
129      * Sort the function table, to enable binary search.
130      */
131     sortFunctions();
132 #endif
133 }
134 
135 #if defined(EXITFREE) || defined(PROTO)
136     void
137 eval_clear(void)
138 {
139     evalvars_clear();
140     free_scriptnames();  // must come after evalvars_clear().
141     free_locales();
142 
143     // autoloaded script names
144     free_autoload_scriptnames();
145 
146     // unreferenced lists and dicts
147     (void)garbage_collect(FALSE);
148 
149     // functions not garbage collected
150     free_all_functions();
151 }
152 #endif
153 
154     void
155 fill_evalarg_from_eap(evalarg_T *evalarg, exarg_T *eap, int skip)
156 {
157     CLEAR_FIELD(*evalarg);
158     evalarg->eval_flags = skip ? 0 : EVAL_EVALUATE;
159     if (eap != NULL && getline_equal(eap->getline, eap->cookie, getsourceline))
160     {
161 	evalarg->eval_getline = eap->getline;
162 	evalarg->eval_cookie = eap->cookie;
163     }
164 }
165 
166 /*
167  * Top level evaluation function, returning a boolean.
168  * Sets "error" to TRUE if there was an error.
169  * Return TRUE or FALSE.
170  */
171     int
172 eval_to_bool(
173     char_u	*arg,
174     int		*error,
175     exarg_T	*eap,
176     int		skip)	    // only parse, don't execute
177 {
178     typval_T	tv;
179     varnumber_T	retval = FALSE;
180     evalarg_T	evalarg;
181 
182     fill_evalarg_from_eap(&evalarg, eap, skip);
183 
184     if (skip)
185 	++emsg_skip;
186     if (eval0(arg, &tv, eap, &evalarg) == FAIL)
187 	*error = TRUE;
188     else
189     {
190 	*error = FALSE;
191 	if (!skip)
192 	{
193 	    if (in_vim9script())
194 		retval = tv2bool(&tv);
195 	    else
196 		retval = (tv_get_number_chk(&tv, error) != 0);
197 	    clear_tv(&tv);
198 	}
199     }
200     if (skip)
201 	--emsg_skip;
202     clear_evalarg(&evalarg, eap);
203 
204     return (int)retval;
205 }
206 
207 /*
208  * Call eval1() and give an error message if not done at a lower level.
209  */
210     static int
211 eval1_emsg(char_u **arg, typval_T *rettv, exarg_T *eap)
212 {
213     char_u	*start = *arg;
214     int		ret;
215     int		did_emsg_before = did_emsg;
216     int		called_emsg_before = called_emsg;
217     evalarg_T	evalarg;
218 
219     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
220 
221     ret = eval1(arg, rettv, &evalarg);
222     if (ret == FAIL)
223     {
224 	// Report the invalid expression unless the expression evaluation has
225 	// been cancelled due to an aborting error, an interrupt, or an
226 	// exception, or we already gave a more specific error.
227 	// Also check called_emsg for when using assert_fails().
228 	if (!aborting() && did_emsg == did_emsg_before
229 					  && called_emsg == called_emsg_before)
230 	    semsg(_(e_invexpr2), start);
231     }
232     clear_evalarg(&evalarg, eap);
233     return ret;
234 }
235 
236 /*
237  * Return whether a typval is a valid expression to pass to eval_expr_typval()
238  * or eval_expr_to_bool().  An empty string returns FALSE;
239  */
240     int
241 eval_expr_valid_arg(typval_T *tv)
242 {
243     return tv->v_type != VAR_UNKNOWN
244 	    && (tv->v_type != VAR_STRING
245 		  || (tv->vval.v_string != NULL && *tv->vval.v_string != NUL));
246 }
247 
248 /*
249  * Evaluate an expression, which can be a function, partial or string.
250  * Pass arguments "argv[argc]".
251  * Return the result in "rettv" and OK or FAIL.
252  */
253     int
254 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
255 {
256     char_u	*s;
257     char_u	buf[NUMBUFLEN];
258     funcexe_T	funcexe;
259 
260     if (expr->v_type == VAR_FUNC)
261     {
262 	s = expr->vval.v_string;
263 	if (s == NULL || *s == NUL)
264 	    return FAIL;
265 	CLEAR_FIELD(funcexe);
266 	funcexe.evaluate = TRUE;
267 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
268 	    return FAIL;
269     }
270     else if (expr->v_type == VAR_PARTIAL)
271     {
272 	partial_T   *partial = expr->vval.v_partial;
273 
274 	if (partial == NULL)
275 	    return FAIL;
276 
277 	if (partial->pt_func != NULL
278 			  && partial->pt_func->uf_def_status != UF_NOT_COMPILED)
279 	{
280 	    if (call_def_function(partial->pt_func, argc, argv,
281 						       partial, rettv) == FAIL)
282 		return FAIL;
283 	}
284 	else
285 	{
286 	    s = partial_name(partial);
287 	    if (s == NULL || *s == NUL)
288 		return FAIL;
289 	    CLEAR_FIELD(funcexe);
290 	    funcexe.evaluate = TRUE;
291 	    funcexe.partial = partial;
292 	    if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
293 		return FAIL;
294 	}
295     }
296     else
297     {
298 	s = tv_get_string_buf_chk(expr, buf);
299 	if (s == NULL)
300 	    return FAIL;
301 	s = skipwhite(s);
302 	if (eval1_emsg(&s, rettv, NULL) == FAIL)
303 	    return FAIL;
304 	if (*skipwhite(s) != NUL)  // check for trailing chars after expr
305 	{
306 	    clear_tv(rettv);
307 	    semsg(_(e_invexpr2), s);
308 	    return FAIL;
309 	}
310     }
311     return OK;
312 }
313 
314 /*
315  * Like eval_to_bool() but using a typval_T instead of a string.
316  * Works for string, funcref and partial.
317  */
318     int
319 eval_expr_to_bool(typval_T *expr, int *error)
320 {
321     typval_T	rettv;
322     int		res;
323 
324     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
325     {
326 	*error = TRUE;
327 	return FALSE;
328     }
329     res = (tv_get_bool_chk(&rettv, error) != 0);
330     clear_tv(&rettv);
331     return res;
332 }
333 
334 /*
335  * Top level evaluation function, returning a string.  If "skip" is TRUE,
336  * only parsing to "nextcmd" is done, without reporting errors.  Return
337  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
338  */
339     char_u *
340 eval_to_string_skip(
341     char_u	*arg,
342     exarg_T	*eap,
343     int		skip)	    // only parse, don't execute
344 {
345     typval_T	tv;
346     char_u	*retval;
347     evalarg_T	evalarg;
348 
349     fill_evalarg_from_eap(&evalarg, eap, skip);
350     if (skip)
351 	++emsg_skip;
352     if (eval0(arg, &tv, eap, &evalarg) == FAIL || skip)
353 	retval = NULL;
354     else
355     {
356 	retval = vim_strsave(tv_get_string(&tv));
357 	clear_tv(&tv);
358     }
359     if (skip)
360 	--emsg_skip;
361     clear_evalarg(&evalarg, eap);
362 
363     return retval;
364 }
365 
366 /*
367  * Skip over an expression at "*pp".
368  * Return FAIL for an error, OK otherwise.
369  */
370     int
371 skip_expr(char_u **pp)
372 {
373     typval_T	rettv;
374 
375     *pp = skipwhite(*pp);
376     return eval1(pp, &rettv, NULL);
377 }
378 
379 /*
380  * Skip over an expression at "*pp".
381  * If in Vim9 script and line breaks are encountered, the lines are
382  * concatenated.  "evalarg->eval_tofree" will be set accordingly.
383  * "arg" is advanced to just after the expression.
384  * "start" is set to the start of the expression, "end" to just after the end.
385  * Also when the expression is copied to allocated memory.
386  * Return FAIL for an error, OK otherwise.
387  */
388     int
389 skip_expr_concatenate(
390 	char_u	    **arg,
391 	char_u	    **start,
392 	char_u	    **end,
393 	evalarg_T   *evalarg)
394 {
395     typval_T	rettv;
396     int		res;
397     int		vim9script = in_vim9script();
398     garray_T    *gap = &evalarg->eval_ga;
399     int		save_flags = evalarg == NULL ? 0 : evalarg->eval_flags;
400     int		evaluate = evalarg == NULL
401 			       ? FALSE : (evalarg->eval_flags & EVAL_EVALUATE);
402 
403     if (vim9script && evaluate
404 	       && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
405     {
406 	ga_init2(gap, sizeof(char_u *), 10);
407 	// leave room for "start"
408 	if (ga_grow(gap, 1) == OK)
409 	    ++gap->ga_len;
410     }
411     *start = *arg;
412 
413     // Don't evaluate the expression.
414     if (evalarg != NULL)
415 	evalarg->eval_flags &= ~EVAL_EVALUATE;
416     *arg = skipwhite(*arg);
417     res = eval1(arg, &rettv, evalarg);
418     *end = *arg;
419     if (evalarg != NULL)
420 	evalarg->eval_flags = save_flags;
421 
422     if (vim9script && evaluate
423 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
424     {
425 	if (evalarg->eval_ga.ga_len == 1)
426 	{
427 	    // just one line, no need to concatenate
428 	    ga_clear(gap);
429 	    gap->ga_itemsize = 0;
430 	}
431 	else
432 	{
433 	    char_u	    *p;
434 	    size_t	    endoff = STRLEN(*arg);
435 
436 	    // Line breaks encountered, concatenate all the lines.
437 	    *((char_u **)gap->ga_data) = *start;
438 	    p = ga_concat_strings(gap, "");
439 
440 	    // free the lines only when using getsourceline()
441 	    if (evalarg->eval_cookie != NULL)
442 	    {
443 		// Do not free the first line, the caller can still use it.
444 		*((char_u **)gap->ga_data) = NULL;
445 		// Do not free the last line, "arg" points into it, free it
446 		// later.
447 		vim_free(evalarg->eval_tofree);
448 		evalarg->eval_tofree =
449 				    ((char_u **)gap->ga_data)[gap->ga_len - 1];
450 		((char_u **)gap->ga_data)[gap->ga_len - 1] = NULL;
451 		ga_clear_strings(gap);
452 	    }
453 	    else
454 		ga_clear(gap);
455 	    gap->ga_itemsize = 0;
456 	    if (p == NULL)
457 		return FAIL;
458 	    *start = p;
459 	    vim_free(evalarg->eval_tofree_lambda);
460 	    evalarg->eval_tofree_lambda = p;
461 	    // Compute "end" relative to the end.
462 	    *end = *start + STRLEN(*start) - endoff;
463 	}
464     }
465 
466     return res;
467 }
468 
469 /*
470  * Top level evaluation function, returning a string.  Does not handle line
471  * breaks.
472  * When "convert" is TRUE convert a List into a sequence of lines and convert
473  * a Float to a String.
474  * Return pointer to allocated memory, or NULL for failure.
475  */
476     char_u *
477 eval_to_string(
478     char_u	*arg,
479     int		convert)
480 {
481     typval_T	tv;
482     char_u	*retval;
483     garray_T	ga;
484 #ifdef FEAT_FLOAT
485     char_u	numbuf[NUMBUFLEN];
486 #endif
487 
488     if (eval0(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
489 	retval = NULL;
490     else
491     {
492 	if (convert && tv.v_type == VAR_LIST)
493 	{
494 	    ga_init2(&ga, (int)sizeof(char), 80);
495 	    if (tv.vval.v_list != NULL)
496 	    {
497 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
498 		if (tv.vval.v_list->lv_len > 0)
499 		    ga_append(&ga, NL);
500 	    }
501 	    ga_append(&ga, NUL);
502 	    retval = (char_u *)ga.ga_data;
503 	}
504 #ifdef FEAT_FLOAT
505 	else if (convert && tv.v_type == VAR_FLOAT)
506 	{
507 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
508 	    retval = vim_strsave(numbuf);
509 	}
510 #endif
511 	else
512 	    retval = vim_strsave(tv_get_string(&tv));
513 	clear_tv(&tv);
514     }
515     clear_evalarg(&EVALARG_EVALUATE, NULL);
516 
517     return retval;
518 }
519 
520 /*
521  * Call eval_to_string() without using current local variables and using
522  * textwinlock.  When "use_sandbox" is TRUE use the sandbox.
523  * Use legacy Vim script syntax.
524  */
525     char_u *
526 eval_to_string_safe(
527     char_u	*arg,
528     int		use_sandbox)
529 {
530     char_u	*retval;
531     funccal_entry_T funccal_entry;
532     int		save_sc_version = current_sctx.sc_version;
533 
534     current_sctx.sc_version = 1;
535     save_funccal(&funccal_entry);
536     if (use_sandbox)
537 	++sandbox;
538     ++textwinlock;
539     retval = eval_to_string(arg, FALSE);
540     if (use_sandbox)
541 	--sandbox;
542     --textwinlock;
543     restore_funccal();
544     current_sctx.sc_version = save_sc_version;
545     return retval;
546 }
547 
548 /*
549  * Top level evaluation function, returning a number.
550  * Evaluates "expr" silently.
551  * Returns -1 for an error.
552  */
553     varnumber_T
554 eval_to_number(char_u *expr)
555 {
556     typval_T	rettv;
557     varnumber_T	retval;
558     char_u	*p = skipwhite(expr);
559 
560     ++emsg_off;
561 
562     if (eval1(&p, &rettv, &EVALARG_EVALUATE) == FAIL)
563 	retval = -1;
564     else
565     {
566 	retval = tv_get_number_chk(&rettv, NULL);
567 	clear_tv(&rettv);
568     }
569     --emsg_off;
570 
571     return retval;
572 }
573 
574 /*
575  * Top level evaluation function.
576  * Returns an allocated typval_T with the result.
577  * Returns NULL when there is an error.
578  */
579     typval_T *
580 eval_expr(char_u *arg, exarg_T *eap)
581 {
582     typval_T	*tv;
583     evalarg_T	evalarg;
584 
585     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
586 
587     tv = ALLOC_ONE(typval_T);
588     if (tv != NULL && eval0(arg, tv, eap, &evalarg) == FAIL)
589 	VIM_CLEAR(tv);
590 
591     clear_evalarg(&evalarg, eap);
592     return tv;
593 }
594 
595 /*
596  * Call some Vim script function and return the result in "*rettv".
597  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
598  * should have type VAR_UNKNOWN.
599  * Returns OK or FAIL.
600  */
601     int
602 call_vim_function(
603     char_u      *func,
604     int		argc,
605     typval_T	*argv,
606     typval_T	*rettv)
607 {
608     int		ret;
609     funcexe_T	funcexe;
610 
611     rettv->v_type = VAR_UNKNOWN;		// clear_tv() uses this
612     CLEAR_FIELD(funcexe);
613     funcexe.firstline = curwin->w_cursor.lnum;
614     funcexe.lastline = curwin->w_cursor.lnum;
615     funcexe.evaluate = TRUE;
616     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
617     if (ret == FAIL)
618 	clear_tv(rettv);
619 
620     return ret;
621 }
622 
623 /*
624  * Call Vim script function "func" and return the result as a number.
625  * Returns -1 when calling the function fails.
626  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
627  * have type VAR_UNKNOWN.
628  */
629     varnumber_T
630 call_func_retnr(
631     char_u      *func,
632     int		argc,
633     typval_T	*argv)
634 {
635     typval_T	rettv;
636     varnumber_T	retval;
637 
638     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
639 	return -1;
640 
641     retval = tv_get_number_chk(&rettv, NULL);
642     clear_tv(&rettv);
643     return retval;
644 }
645 
646 /*
647  * Call Vim script function "func" and return the result as a string.
648  * Returns NULL when calling the function fails.
649  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
650  * have type VAR_UNKNOWN.
651  */
652     void *
653 call_func_retstr(
654     char_u      *func,
655     int		argc,
656     typval_T	*argv)
657 {
658     typval_T	rettv;
659     char_u	*retval;
660 
661     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
662 	return NULL;
663 
664     retval = vim_strsave(tv_get_string(&rettv));
665     clear_tv(&rettv);
666     return retval;
667 }
668 
669 /*
670  * Call Vim script function "func" and return the result as a List.
671  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
672  * have type VAR_UNKNOWN.
673  * Returns NULL when there is something wrong.
674  */
675     void *
676 call_func_retlist(
677     char_u      *func,
678     int		argc,
679     typval_T	*argv)
680 {
681     typval_T	rettv;
682 
683     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
684 	return NULL;
685 
686     if (rettv.v_type != VAR_LIST)
687     {
688 	clear_tv(&rettv);
689 	return NULL;
690     }
691 
692     return rettv.vval.v_list;
693 }
694 
695 #ifdef FEAT_FOLDING
696 /*
697  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
698  * it in "*cp".  Doesn't give error messages.
699  */
700     int
701 eval_foldexpr(char_u *arg, int *cp)
702 {
703     typval_T	tv;
704     varnumber_T	retval;
705     char_u	*s;
706     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
707 								   OPT_LOCAL);
708 
709     ++emsg_off;
710     if (use_sandbox)
711 	++sandbox;
712     ++textwinlock;
713     *cp = NUL;
714     if (eval0(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
715 	retval = 0;
716     else
717     {
718 	// If the result is a number, just return the number.
719 	if (tv.v_type == VAR_NUMBER)
720 	    retval = tv.vval.v_number;
721 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
722 	    retval = 0;
723 	else
724 	{
725 	    // If the result is a string, check if there is a non-digit before
726 	    // the number.
727 	    s = tv.vval.v_string;
728 	    if (!VIM_ISDIGIT(*s) && *s != '-')
729 		*cp = *s++;
730 	    retval = atol((char *)s);
731 	}
732 	clear_tv(&tv);
733     }
734     --emsg_off;
735     if (use_sandbox)
736 	--sandbox;
737     --textwinlock;
738     clear_evalarg(&EVALARG_EVALUATE, NULL);
739 
740     return (int)retval;
741 }
742 #endif
743 
744 /*
745  * Get an lval: variable, Dict item or List item that can be assigned a value
746  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
747  * "name.key", "name.key[expr]" etc.
748  * Indexing only works if "name" is an existing List or Dictionary.
749  * "name" points to the start of the name.
750  * If "rettv" is not NULL it points to the value to be assigned.
751  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
752  * wrong; must end in space or cmd separator.
753  *
754  * flags:
755  *  GLV_QUIET:       do not give error messages
756  *  GLV_READ_ONLY:   will not change the variable
757  *  GLV_NO_AUTOLOAD: do not use script autoloading
758  *
759  * Returns a pointer to just after the name, including indexes.
760  * When an evaluation error occurs "lp->ll_name" is NULL;
761  * Returns NULL for a parsing error.  Still need to free items in "lp"!
762  */
763     char_u *
764 get_lval(
765     char_u	*name,
766     typval_T	*rettv,
767     lval_T	*lp,
768     int		unlet,
769     int		skip,
770     int		flags,	    // GLV_ values
771     int		fne_flags)  // flags for find_name_end()
772 {
773     char_u	*p;
774     char_u	*expr_start, *expr_end;
775     int		cc;
776     dictitem_T	*v;
777     typval_T	var1;
778     typval_T	var2;
779     int		empty1 = FALSE;
780     listitem_T	*ni;
781     char_u	*key = NULL;
782     int		len;
783     hashtab_T	*ht;
784     int		quiet = flags & GLV_QUIET;
785 
786     // Clear everything in "lp".
787     CLEAR_POINTER(lp);
788 
789     if (skip)
790     {
791 	// When skipping just find the end of the name.
792 	lp->ll_name = name;
793 	lp->ll_name_end = find_name_end(name, NULL, NULL,
794 						      FNE_INCL_BR | fne_flags);
795 	return lp->ll_name_end;
796     }
797 
798     // Find the end of the name.
799     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
800     lp->ll_name_end = p;
801     if (expr_start != NULL)
802     {
803 	// Don't expand the name when we already know there is an error.
804 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
805 						    && *p != '[' && *p != '.')
806 	{
807 	    semsg(_(e_trailing_arg), p);
808 	    return NULL;
809 	}
810 
811 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
812 	if (lp->ll_exp_name == NULL)
813 	{
814 	    // Report an invalid expression in braces, unless the
815 	    // expression evaluation has been cancelled due to an
816 	    // aborting error, an interrupt, or an exception.
817 	    if (!aborting() && !quiet)
818 	    {
819 		emsg_severe = TRUE;
820 		semsg(_(e_invarg2), name);
821 		return NULL;
822 	    }
823 	}
824 	lp->ll_name = lp->ll_exp_name;
825     }
826     else
827     {
828 	lp->ll_name = name;
829 
830 	if (in_vim9script())
831 	{
832 	    // "a: type" is declaring variable "a" with a type, not "a:".
833 	    if (p == name + 2 && p[-1] == ':')
834 	    {
835 		--p;
836 		lp->ll_name_end = p;
837 	    }
838 	    if (*p == ':')
839 	    {
840 		scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);
841 		char_u	 *tp = skipwhite(p + 1);
842 
843 		// parse the type after the name
844 		lp->ll_type = parse_type(&tp, &si->sn_type_list);
845 		lp->ll_name_end = tp;
846 	    }
847 	}
848     }
849 
850     // Without [idx] or .key we are done.
851     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
852 	return p;
853 
854     cc = *p;
855     *p = NUL;
856     // Only pass &ht when we would write to the variable, it prevents autoload
857     // as well.
858     v = find_var(lp->ll_name, (flags & GLV_READ_ONLY) ? NULL : &ht,
859 						      flags & GLV_NO_AUTOLOAD);
860     if (v == NULL && !quiet)
861 	semsg(_(e_undefined_variable_str), lp->ll_name);
862     *p = cc;
863     if (v == NULL)
864 	return NULL;
865 
866     /*
867      * Loop until no more [idx] or .key is following.
868      */
869     lp->ll_tv = &v->di_tv;
870     var1.v_type = VAR_UNKNOWN;
871     var2.v_type = VAR_UNKNOWN;
872     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
873     {
874 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
875 		&& !(lp->ll_tv->v_type == VAR_DICT
876 					   && lp->ll_tv->vval.v_dict != NULL)
877 		&& !(lp->ll_tv->v_type == VAR_BLOB
878 					   && lp->ll_tv->vval.v_blob != NULL))
879 	{
880 	    if (!quiet)
881 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
882 	    return NULL;
883 	}
884 	if (lp->ll_range)
885 	{
886 	    if (!quiet)
887 		emsg(_("E708: [:] must come last"));
888 	    return NULL;
889 	}
890 
891 	len = -1;
892 	if (*p == '.')
893 	{
894 	    key = p + 1;
895 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
896 		;
897 	    if (len == 0)
898 	    {
899 		if (!quiet)
900 		    emsg(_(e_emptykey));
901 		return NULL;
902 	    }
903 	    p = key + len;
904 	}
905 	else
906 	{
907 	    // Get the index [expr] or the first index [expr: ].
908 	    p = skipwhite(p + 1);
909 	    if (*p == ':')
910 		empty1 = TRUE;
911 	    else
912 	    {
913 		empty1 = FALSE;
914 		if (eval1(&p, &var1, &EVALARG_EVALUATE) == FAIL)  // recursive!
915 		    return NULL;
916 		if (tv_get_string_chk(&var1) == NULL)
917 		{
918 		    // not a number or string
919 		    clear_tv(&var1);
920 		    return NULL;
921 		}
922 		p = skipwhite(p);
923 	    }
924 
925 	    // Optionally get the second index [ :expr].
926 	    if (*p == ':')
927 	    {
928 		if (lp->ll_tv->v_type == VAR_DICT)
929 		{
930 		    if (!quiet)
931 			emsg(_(e_cannot_slice_dictionary));
932 		    clear_tv(&var1);
933 		    return NULL;
934 		}
935 		if (rettv != NULL
936 			&& !(rettv->v_type == VAR_LIST
937 						 && rettv->vval.v_list != NULL)
938 			&& !(rettv->v_type == VAR_BLOB
939 						&& rettv->vval.v_blob != NULL))
940 		{
941 		    if (!quiet)
942 			emsg(_("E709: [:] requires a List or Blob value"));
943 		    clear_tv(&var1);
944 		    return NULL;
945 		}
946 		p = skipwhite(p + 1);
947 		if (*p == ']')
948 		    lp->ll_empty2 = TRUE;
949 		else
950 		{
951 		    lp->ll_empty2 = FALSE;
952 		    // recursive!
953 		    if (eval1(&p, &var2, &EVALARG_EVALUATE) == FAIL)
954 		    {
955 			clear_tv(&var1);
956 			return NULL;
957 		    }
958 		    if (tv_get_string_chk(&var2) == NULL)
959 		    {
960 			// not a number or string
961 			clear_tv(&var1);
962 			clear_tv(&var2);
963 			return NULL;
964 		    }
965 		}
966 		lp->ll_range = TRUE;
967 	    }
968 	    else
969 		lp->ll_range = FALSE;
970 
971 	    if (*p != ']')
972 	    {
973 		if (!quiet)
974 		    emsg(_(e_missbrac));
975 		clear_tv(&var1);
976 		clear_tv(&var2);
977 		return NULL;
978 	    }
979 
980 	    // Skip to past ']'.
981 	    ++p;
982 	}
983 
984 	if (lp->ll_tv->v_type == VAR_DICT)
985 	{
986 	    if (len == -1)
987 	    {
988 		// "[key]": get key from "var1"
989 		key = tv_get_string_chk(&var1);	// is number or string
990 		if (key == NULL)
991 		{
992 		    clear_tv(&var1);
993 		    return NULL;
994 		}
995 	    }
996 	    lp->ll_list = NULL;
997 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
998 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
999 
1000 	    // When assigning to a scope dictionary check that a function and
1001 	    // variable name is valid (only variable name unless it is l: or
1002 	    // g: dictionary). Disallow overwriting a builtin function.
1003 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
1004 	    {
1005 		int prevval;
1006 		int wrong;
1007 
1008 		if (len != -1)
1009 		{
1010 		    prevval = key[len];
1011 		    key[len] = NUL;
1012 		}
1013 		else
1014 		    prevval = 0; // avoid compiler warning
1015 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
1016 			       && rettv->v_type == VAR_FUNC
1017 			       && var_wrong_func_name(key, lp->ll_di == NULL))
1018 			|| !valid_varname(key);
1019 		if (len != -1)
1020 		    key[len] = prevval;
1021 		if (wrong)
1022 		{
1023 		    clear_tv(&var1);
1024 		    return NULL;
1025 		}
1026 	    }
1027 
1028 	    if (lp->ll_di == NULL)
1029 	    {
1030 		// Can't add "v:" or "a:" variable.
1031 		if (lp->ll_dict == get_vimvar_dict()
1032 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
1033 		{
1034 		    semsg(_(e_illvar), name);
1035 		    clear_tv(&var1);
1036 		    return NULL;
1037 		}
1038 
1039 		// Key does not exist in dict: may need to add it.
1040 		if (*p == '[' || *p == '.' || unlet)
1041 		{
1042 		    if (!quiet)
1043 			semsg(_(e_dictkey), key);
1044 		    clear_tv(&var1);
1045 		    return NULL;
1046 		}
1047 		if (len == -1)
1048 		    lp->ll_newkey = vim_strsave(key);
1049 		else
1050 		    lp->ll_newkey = vim_strnsave(key, len);
1051 		clear_tv(&var1);
1052 		if (lp->ll_newkey == NULL)
1053 		    p = NULL;
1054 		break;
1055 	    }
1056 	    // existing variable, need to check if it can be changed
1057 	    else if ((flags & GLV_READ_ONLY) == 0
1058 			     && var_check_ro(lp->ll_di->di_flags, name, FALSE))
1059 	    {
1060 		clear_tv(&var1);
1061 		return NULL;
1062 	    }
1063 
1064 	    clear_tv(&var1);
1065 	    lp->ll_tv = &lp->ll_di->di_tv;
1066 	}
1067 	else if (lp->ll_tv->v_type == VAR_BLOB)
1068 	{
1069 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
1070 
1071 	    /*
1072 	     * Get the number and item for the only or first index of the List.
1073 	     */
1074 	    if (empty1)
1075 		lp->ll_n1 = 0;
1076 	    else
1077 		// is number or string
1078 		lp->ll_n1 = (long)tv_get_number(&var1);
1079 	    clear_tv(&var1);
1080 
1081 	    if (lp->ll_n1 < 0
1082 		    || lp->ll_n1 > bloblen
1083 		    || (lp->ll_range && lp->ll_n1 == bloblen))
1084 	    {
1085 		if (!quiet)
1086 		    semsg(_(e_blobidx), lp->ll_n1);
1087 		clear_tv(&var2);
1088 		return NULL;
1089 	    }
1090 	    if (lp->ll_range && !lp->ll_empty2)
1091 	    {
1092 		lp->ll_n2 = (long)tv_get_number(&var2);
1093 		clear_tv(&var2);
1094 		if (lp->ll_n2 < 0
1095 			|| lp->ll_n2 >= bloblen
1096 			|| lp->ll_n2 < lp->ll_n1)
1097 		{
1098 		    if (!quiet)
1099 			semsg(_(e_blobidx), lp->ll_n2);
1100 		    return NULL;
1101 		}
1102 	    }
1103 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
1104 	    lp->ll_tv = NULL;
1105 	    break;
1106 	}
1107 	else
1108 	{
1109 	    /*
1110 	     * Get the number and item for the only or first index of the List.
1111 	     */
1112 	    if (empty1)
1113 		lp->ll_n1 = 0;
1114 	    else
1115 		// is number or string
1116 		lp->ll_n1 = (long)tv_get_number(&var1);
1117 	    clear_tv(&var1);
1118 
1119 	    lp->ll_dict = NULL;
1120 	    lp->ll_list = lp->ll_tv->vval.v_list;
1121 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
1122 	    if (lp->ll_li == NULL)
1123 	    {
1124 		if (lp->ll_n1 < 0)
1125 		{
1126 		    lp->ll_n1 = 0;
1127 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
1128 		}
1129 	    }
1130 	    if (lp->ll_li == NULL)
1131 	    {
1132 		clear_tv(&var2);
1133 		if (!quiet)
1134 		    semsg(_(e_listidx), lp->ll_n1);
1135 		return NULL;
1136 	    }
1137 
1138 	    /*
1139 	     * May need to find the item or absolute index for the second
1140 	     * index of a range.
1141 	     * When no index given: "lp->ll_empty2" is TRUE.
1142 	     * Otherwise "lp->ll_n2" is set to the second index.
1143 	     */
1144 	    if (lp->ll_range && !lp->ll_empty2)
1145 	    {
1146 		lp->ll_n2 = (long)tv_get_number(&var2);
1147 						    // is number or string
1148 		clear_tv(&var2);
1149 		if (lp->ll_n2 < 0)
1150 		{
1151 		    ni = list_find(lp->ll_list, lp->ll_n2);
1152 		    if (ni == NULL)
1153 		    {
1154 			if (!quiet)
1155 			    semsg(_(e_listidx), lp->ll_n2);
1156 			return NULL;
1157 		    }
1158 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
1159 		}
1160 
1161 		// Check that lp->ll_n2 isn't before lp->ll_n1.
1162 		if (lp->ll_n1 < 0)
1163 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
1164 		if (lp->ll_n2 < lp->ll_n1)
1165 		{
1166 		    if (!quiet)
1167 			semsg(_(e_listidx), lp->ll_n2);
1168 		    return NULL;
1169 		}
1170 	    }
1171 
1172 	    lp->ll_tv = &lp->ll_li->li_tv;
1173 	}
1174     }
1175 
1176     clear_tv(&var1);
1177     lp->ll_name_end = p;
1178     return p;
1179 }
1180 
1181 /*
1182  * Clear lval "lp" that was filled by get_lval().
1183  */
1184     void
1185 clear_lval(lval_T *lp)
1186 {
1187     vim_free(lp->ll_exp_name);
1188     vim_free(lp->ll_newkey);
1189 }
1190 
1191 /*
1192  * Set a variable that was parsed by get_lval() to "rettv".
1193  * "endp" points to just after the parsed name.
1194  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
1195  * "%" for "%=", "." for ".=" or "=" for "=".
1196  */
1197     void
1198 set_var_lval(
1199     lval_T	*lp,
1200     char_u	*endp,
1201     typval_T	*rettv,
1202     int		copy,
1203     int		flags,    // LET_IS_CONST and/or LET_NO_COMMAND
1204     char_u	*op)
1205 {
1206     int		cc;
1207     listitem_T	*ri;
1208     dictitem_T	*di;
1209 
1210     if (lp->ll_tv == NULL)
1211     {
1212 	cc = *endp;
1213 	*endp = NUL;
1214 	if (lp->ll_blob != NULL)
1215 	{
1216 	    int	    error = FALSE, val;
1217 
1218 	    if (op != NULL && *op != '=')
1219 	    {
1220 		semsg(_(e_letwrong), op);
1221 		return;
1222 	    }
1223 	    if (var_check_lock(lp->ll_blob->bv_lock, lp->ll_name, FALSE))
1224 		return;
1225 
1226 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
1227 	    {
1228 		int	il, ir;
1229 
1230 		if (lp->ll_empty2)
1231 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
1232 
1233 		if (lp->ll_n2 - lp->ll_n1 + 1 != blob_len(rettv->vval.v_blob))
1234 		{
1235 		    emsg(_("E972: Blob value does not have the right number of bytes"));
1236 		    return;
1237 		}
1238 		if (lp->ll_empty2)
1239 		    lp->ll_n2 = blob_len(lp->ll_blob);
1240 
1241 		ir = 0;
1242 		for (il = lp->ll_n1; il <= lp->ll_n2; il++)
1243 		    blob_set(lp->ll_blob, il,
1244 			    blob_get(rettv->vval.v_blob, ir++));
1245 	    }
1246 	    else
1247 	    {
1248 		val = (int)tv_get_number_chk(rettv, &error);
1249 		if (!error)
1250 		{
1251 		    garray_T *gap = &lp->ll_blob->bv_ga;
1252 
1253 		    // Allow for appending a byte.  Setting a byte beyond
1254 		    // the end is an error otherwise.
1255 		    if (lp->ll_n1 < gap->ga_len
1256 			    || (lp->ll_n1 == gap->ga_len
1257 				&& ga_grow(&lp->ll_blob->bv_ga, 1) == OK))
1258 		    {
1259 			blob_set(lp->ll_blob, lp->ll_n1, val);
1260 			if (lp->ll_n1 == gap->ga_len)
1261 			    ++gap->ga_len;
1262 		    }
1263 		    // error for invalid range was already given in get_lval()
1264 		}
1265 	    }
1266 	}
1267 	else if (op != NULL && *op != '=')
1268 	{
1269 	    typval_T tv;
1270 
1271 	    if (flags & LET_IS_CONST)
1272 	    {
1273 		emsg(_(e_cannot_mod));
1274 		*endp = cc;
1275 		return;
1276 	    }
1277 
1278 	    // handle +=, -=, *=, /=, %= and .=
1279 	    di = NULL;
1280 	    if (eval_variable(lp->ll_name, (int)STRLEN(lp->ll_name),
1281 					     &tv, &di, TRUE, FALSE) == OK)
1282 	    {
1283 		if ((di == NULL
1284 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
1285 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
1286 			&& tv_op(&tv, rettv, op) == OK)
1287 		    set_var(lp->ll_name, &tv, FALSE);
1288 		clear_tv(&tv);
1289 	    }
1290 	}
1291 	else
1292 	{
1293 	    if (lp->ll_type != NULL
1294 			      && check_typval_type(lp->ll_type, rettv) == FAIL)
1295 		return;
1296 	    set_var_const(lp->ll_name, lp->ll_type, rettv, copy, flags);
1297 	}
1298 	*endp = cc;
1299     }
1300     else if (var_check_lock(lp->ll_newkey == NULL
1301 		? lp->ll_tv->v_lock
1302 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
1303 	;
1304     else if (lp->ll_range)
1305     {
1306 	listitem_T *ll_li = lp->ll_li;
1307 	int	    ll_n1 = lp->ll_n1;
1308 
1309 	if (flags & LET_IS_CONST)
1310 	{
1311 	    emsg(_("E996: Cannot lock a range"));
1312 	    return;
1313 	}
1314 
1315 	/*
1316 	 * Check whether any of the list items is locked
1317 	 */
1318 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
1319 	{
1320 	    if (var_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
1321 		return;
1322 	    ri = ri->li_next;
1323 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
1324 		break;
1325 	    ll_li = ll_li->li_next;
1326 	    ++ll_n1;
1327 	}
1328 
1329 	/*
1330 	 * Assign the List values to the list items.
1331 	 */
1332 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
1333 	{
1334 	    if (op != NULL && *op != '=')
1335 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
1336 	    else
1337 	    {
1338 		clear_tv(&lp->ll_li->li_tv);
1339 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
1340 	    }
1341 	    ri = ri->li_next;
1342 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
1343 		break;
1344 	    if (lp->ll_li->li_next == NULL)
1345 	    {
1346 		// Need to add an empty item.
1347 		if (list_append_number(lp->ll_list, 0) == FAIL)
1348 		{
1349 		    ri = NULL;
1350 		    break;
1351 		}
1352 	    }
1353 	    lp->ll_li = lp->ll_li->li_next;
1354 	    ++lp->ll_n1;
1355 	}
1356 	if (ri != NULL)
1357 	    emsg(_("E710: List value has more items than target"));
1358 	else if (lp->ll_empty2
1359 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
1360 		: lp->ll_n1 != lp->ll_n2)
1361 	    emsg(_("E711: List value has not enough items"));
1362     }
1363     else
1364     {
1365 	/*
1366 	 * Assign to a List or Dictionary item.
1367 	 */
1368 	if (flags & LET_IS_CONST)
1369 	{
1370 	    emsg(_("E996: Cannot lock a list or dict"));
1371 	    return;
1372 	}
1373 	if (lp->ll_newkey != NULL)
1374 	{
1375 	    if (op != NULL && *op != '=')
1376 	    {
1377 		semsg(_(e_letwrong), op);
1378 		return;
1379 	    }
1380 
1381 	    // Need to add an item to the Dictionary.
1382 	    di = dictitem_alloc(lp->ll_newkey);
1383 	    if (di == NULL)
1384 		return;
1385 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
1386 	    {
1387 		vim_free(di);
1388 		return;
1389 	    }
1390 	    lp->ll_tv = &di->di_tv;
1391 	}
1392 	else if (op != NULL && *op != '=')
1393 	{
1394 	    tv_op(lp->ll_tv, rettv, op);
1395 	    return;
1396 	}
1397 	else
1398 	    clear_tv(lp->ll_tv);
1399 
1400 	/*
1401 	 * Assign the value to the variable or list item.
1402 	 */
1403 	if (copy)
1404 	    copy_tv(rettv, lp->ll_tv);
1405 	else
1406 	{
1407 	    *lp->ll_tv = *rettv;
1408 	    lp->ll_tv->v_lock = 0;
1409 	    init_tv(rettv);
1410 	}
1411     }
1412 }
1413 
1414 /*
1415  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
1416  * and "tv1 .= tv2"
1417  * Returns OK or FAIL.
1418  */
1419     static int
1420 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
1421 {
1422     varnumber_T	n;
1423     char_u	numbuf[NUMBUFLEN];
1424     char_u	*s;
1425 
1426     // Can't do anything with a Funcref, Dict, v:true on the right.
1427     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
1428 		      && tv2->v_type != VAR_BOOL && tv2->v_type != VAR_SPECIAL)
1429     {
1430 	switch (tv1->v_type)
1431 	{
1432 	    case VAR_UNKNOWN:
1433 	    case VAR_ANY:
1434 	    case VAR_VOID:
1435 	    case VAR_DICT:
1436 	    case VAR_FUNC:
1437 	    case VAR_PARTIAL:
1438 	    case VAR_BOOL:
1439 	    case VAR_SPECIAL:
1440 	    case VAR_JOB:
1441 	    case VAR_CHANNEL:
1442 		break;
1443 
1444 	    case VAR_BLOB:
1445 		if (*op != '+' || tv2->v_type != VAR_BLOB)
1446 		    break;
1447 		// BLOB += BLOB
1448 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
1449 		{
1450 		    blob_T  *b1 = tv1->vval.v_blob;
1451 		    blob_T  *b2 = tv2->vval.v_blob;
1452 		    int	i, len = blob_len(b2);
1453 		    for (i = 0; i < len; i++)
1454 			ga_append(&b1->bv_ga, blob_get(b2, i));
1455 		}
1456 		return OK;
1457 
1458 	    case VAR_LIST:
1459 		if (*op != '+' || tv2->v_type != VAR_LIST)
1460 		    break;
1461 		// List += List
1462 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
1463 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
1464 		return OK;
1465 
1466 	    case VAR_NUMBER:
1467 	    case VAR_STRING:
1468 		if (tv2->v_type == VAR_LIST)
1469 		    break;
1470 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
1471 		{
1472 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
1473 		    n = tv_get_number(tv1);
1474 #ifdef FEAT_FLOAT
1475 		    if (tv2->v_type == VAR_FLOAT)
1476 		    {
1477 			float_T f = n;
1478 
1479 			if (*op == '%')
1480 			    break;
1481 			switch (*op)
1482 			{
1483 			    case '+': f += tv2->vval.v_float; break;
1484 			    case '-': f -= tv2->vval.v_float; break;
1485 			    case '*': f *= tv2->vval.v_float; break;
1486 			    case '/': f /= tv2->vval.v_float; break;
1487 			}
1488 			clear_tv(tv1);
1489 			tv1->v_type = VAR_FLOAT;
1490 			tv1->vval.v_float = f;
1491 		    }
1492 		    else
1493 #endif
1494 		    {
1495 			switch (*op)
1496 			{
1497 			    case '+': n += tv_get_number(tv2); break;
1498 			    case '-': n -= tv_get_number(tv2); break;
1499 			    case '*': n *= tv_get_number(tv2); break;
1500 			    case '/': n = num_divide(n, tv_get_number(tv2)); break;
1501 			    case '%': n = num_modulus(n, tv_get_number(tv2)); break;
1502 			}
1503 			clear_tv(tv1);
1504 			tv1->v_type = VAR_NUMBER;
1505 			tv1->vval.v_number = n;
1506 		    }
1507 		}
1508 		else
1509 		{
1510 		    if (tv2->v_type == VAR_FLOAT)
1511 			break;
1512 
1513 		    // str .= str
1514 		    s = tv_get_string(tv1);
1515 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
1516 		    clear_tv(tv1);
1517 		    tv1->v_type = VAR_STRING;
1518 		    tv1->vval.v_string = s;
1519 		}
1520 		return OK;
1521 
1522 	    case VAR_FLOAT:
1523 #ifdef FEAT_FLOAT
1524 		{
1525 		    float_T f;
1526 
1527 		    if (*op == '%' || *op == '.'
1528 				   || (tv2->v_type != VAR_FLOAT
1529 				    && tv2->v_type != VAR_NUMBER
1530 				    && tv2->v_type != VAR_STRING))
1531 			break;
1532 		    if (tv2->v_type == VAR_FLOAT)
1533 			f = tv2->vval.v_float;
1534 		    else
1535 			f = tv_get_number(tv2);
1536 		    switch (*op)
1537 		    {
1538 			case '+': tv1->vval.v_float += f; break;
1539 			case '-': tv1->vval.v_float -= f; break;
1540 			case '*': tv1->vval.v_float *= f; break;
1541 			case '/': tv1->vval.v_float /= f; break;
1542 		    }
1543 		}
1544 #endif
1545 		return OK;
1546 	}
1547     }
1548 
1549     semsg(_(e_letwrong), op);
1550     return FAIL;
1551 }
1552 
1553 /*
1554  * Evaluate the expression used in a ":for var in expr" command.
1555  * "arg" points to "var".
1556  * Set "*errp" to TRUE for an error, FALSE otherwise;
1557  * Return a pointer that holds the info.  Null when there is an error.
1558  */
1559     void *
1560 eval_for_line(
1561     char_u	*arg,
1562     int		*errp,
1563     exarg_T	*eap,
1564     evalarg_T	*evalarg)
1565 {
1566     forinfo_T	*fi;
1567     char_u	*expr;
1568     typval_T	tv;
1569     list_T	*l;
1570     int		skip = !(evalarg->eval_flags & EVAL_EVALUATE);
1571 
1572     *errp = TRUE;	// default: there is an error
1573 
1574     fi = ALLOC_CLEAR_ONE(forinfo_T);
1575     if (fi == NULL)
1576 	return NULL;
1577 
1578     expr = skip_var_list(arg, TRUE, &fi->fi_varcount, &fi->fi_semicolon, FALSE);
1579     if (expr == NULL)
1580 	return fi;
1581 
1582     expr = skipwhite_and_linebreak(expr, evalarg);
1583     if (expr[0] != 'i' || expr[1] != 'n'
1584 				  || !(expr[2] == NUL || VIM_ISWHITE(expr[2])))
1585     {
1586 	emsg(_(e_missing_in));
1587 	return fi;
1588     }
1589 
1590     if (skip)
1591 	++emsg_skip;
1592     expr = skipwhite_and_linebreak(expr + 2, evalarg);
1593     if (eval0(expr, &tv, eap, evalarg) == OK)
1594     {
1595 	*errp = FALSE;
1596 	if (!skip)
1597 	{
1598 	    if (tv.v_type == VAR_LIST)
1599 	    {
1600 		l = tv.vval.v_list;
1601 		if (l == NULL)
1602 		{
1603 		    // a null list is like an empty list: do nothing
1604 		    clear_tv(&tv);
1605 		}
1606 		else
1607 		{
1608 		    // Need a real list here.
1609 		    CHECK_LIST_MATERIALIZE(l);
1610 
1611 		    // No need to increment the refcount, it's already set for
1612 		    // the list being used in "tv".
1613 		    fi->fi_list = l;
1614 		    list_add_watch(l, &fi->fi_lw);
1615 		    fi->fi_lw.lw_item = l->lv_first;
1616 		}
1617 	    }
1618 	    else if (tv.v_type == VAR_BLOB)
1619 	    {
1620 		fi->fi_bi = 0;
1621 		if (tv.vval.v_blob != NULL)
1622 		{
1623 		    typval_T btv;
1624 
1625 		    // Make a copy, so that the iteration still works when the
1626 		    // blob is changed.
1627 		    blob_copy(tv.vval.v_blob, &btv);
1628 		    fi->fi_blob = btv.vval.v_blob;
1629 		}
1630 		clear_tv(&tv);
1631 	    }
1632 	    else
1633 	    {
1634 		emsg(_(e_listreq));
1635 		clear_tv(&tv);
1636 	    }
1637 	}
1638     }
1639     if (skip)
1640 	--emsg_skip;
1641     fi->fi_break_count = evalarg->eval_break_count;
1642 
1643     return fi;
1644 }
1645 
1646 /*
1647  * Used when looping over a :for line, skip the "in expr" part.
1648  */
1649     void
1650 skip_for_lines(void *fi_void, evalarg_T *evalarg)
1651 {
1652     forinfo_T	*fi = (forinfo_T *)fi_void;
1653     int		i;
1654 
1655     for (i = 0; i < fi->fi_break_count; ++i)
1656 	eval_next_line(evalarg);
1657 }
1658 
1659 /*
1660  * Use the first item in a ":for" list.  Advance to the next.
1661  * Assign the values to the variable (list).  "arg" points to the first one.
1662  * Return TRUE when a valid item was found, FALSE when at end of list or
1663  * something wrong.
1664  */
1665     int
1666 next_for_item(void *fi_void, char_u *arg)
1667 {
1668     forinfo_T	*fi = (forinfo_T *)fi_void;
1669     int		result;
1670     int		flag = in_vim9script() ?  LET_NO_COMMAND : 0;
1671     listitem_T	*item;
1672 
1673     if (fi->fi_blob != NULL)
1674     {
1675 	typval_T	tv;
1676 
1677 	if (fi->fi_bi >= blob_len(fi->fi_blob))
1678 	    return FALSE;
1679 	tv.v_type = VAR_NUMBER;
1680 	tv.v_lock = VAR_FIXED;
1681 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
1682 	++fi->fi_bi;
1683 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1684 				       fi->fi_varcount, flag, NULL) == OK;
1685     }
1686 
1687     item = fi->fi_lw.lw_item;
1688     if (item == NULL)
1689 	result = FALSE;
1690     else
1691     {
1692 	fi->fi_lw.lw_item = item->li_next;
1693 	result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
1694 				      fi->fi_varcount, flag, NULL) == OK);
1695     }
1696     return result;
1697 }
1698 
1699 /*
1700  * Free the structure used to store info used by ":for".
1701  */
1702     void
1703 free_for_info(void *fi_void)
1704 {
1705     forinfo_T    *fi = (forinfo_T *)fi_void;
1706 
1707     if (fi != NULL && fi->fi_list != NULL)
1708     {
1709 	list_rem_watch(fi->fi_list, &fi->fi_lw);
1710 	list_unref(fi->fi_list);
1711     }
1712     if (fi != NULL && fi->fi_blob != NULL)
1713 	blob_unref(fi->fi_blob);
1714     vim_free(fi);
1715 }
1716 
1717     void
1718 set_context_for_expression(
1719     expand_T	*xp,
1720     char_u	*arg,
1721     cmdidx_T	cmdidx)
1722 {
1723     int		got_eq = FALSE;
1724     int		c;
1725     char_u	*p;
1726 
1727     if (cmdidx == CMD_let || cmdidx == CMD_const)
1728     {
1729 	xp->xp_context = EXPAND_USER_VARS;
1730 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
1731 	{
1732 	    // ":let var1 var2 ...": find last space.
1733 	    for (p = arg + STRLEN(arg); p >= arg; )
1734 	    {
1735 		xp->xp_pattern = p;
1736 		MB_PTR_BACK(arg, p);
1737 		if (VIM_ISWHITE(*p))
1738 		    break;
1739 	    }
1740 	    return;
1741 	}
1742     }
1743     else
1744 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
1745 							  : EXPAND_EXPRESSION;
1746     while ((xp->xp_pattern = vim_strpbrk(arg,
1747 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
1748     {
1749 	c = *xp->xp_pattern;
1750 	if (c == '&')
1751 	{
1752 	    c = xp->xp_pattern[1];
1753 	    if (c == '&')
1754 	    {
1755 		++xp->xp_pattern;
1756 		xp->xp_context = cmdidx != CMD_let || got_eq
1757 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
1758 	    }
1759 	    else if (c != ' ')
1760 	    {
1761 		xp->xp_context = EXPAND_SETTINGS;
1762 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
1763 		    xp->xp_pattern += 2;
1764 
1765 	    }
1766 	}
1767 	else if (c == '$')
1768 	{
1769 	    // environment variable
1770 	    xp->xp_context = EXPAND_ENV_VARS;
1771 	}
1772 	else if (c == '=')
1773 	{
1774 	    got_eq = TRUE;
1775 	    xp->xp_context = EXPAND_EXPRESSION;
1776 	}
1777 	else if (c == '#'
1778 		&& xp->xp_context == EXPAND_EXPRESSION)
1779 	{
1780 	    // Autoload function/variable contains '#'.
1781 	    break;
1782 	}
1783 	else if ((c == '<' || c == '#')
1784 		&& xp->xp_context == EXPAND_FUNCTIONS
1785 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
1786 	{
1787 	    // Function name can start with "<SNR>" and contain '#'.
1788 	    break;
1789 	}
1790 	else if (cmdidx != CMD_let || got_eq)
1791 	{
1792 	    if (c == '"')	    // string
1793 	    {
1794 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
1795 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
1796 			++xp->xp_pattern;
1797 		xp->xp_context = EXPAND_NOTHING;
1798 	    }
1799 	    else if (c == '\'')	    // literal string
1800 	    {
1801 		// Trick: '' is like stopping and starting a literal string.
1802 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
1803 		    /* skip */ ;
1804 		xp->xp_context = EXPAND_NOTHING;
1805 	    }
1806 	    else if (c == '|')
1807 	    {
1808 		if (xp->xp_pattern[1] == '|')
1809 		{
1810 		    ++xp->xp_pattern;
1811 		    xp->xp_context = EXPAND_EXPRESSION;
1812 		}
1813 		else
1814 		    xp->xp_context = EXPAND_COMMANDS;
1815 	    }
1816 	    else
1817 		xp->xp_context = EXPAND_EXPRESSION;
1818 	}
1819 	else
1820 	    // Doesn't look like something valid, expand as an expression
1821 	    // anyway.
1822 	    xp->xp_context = EXPAND_EXPRESSION;
1823 	arg = xp->xp_pattern;
1824 	if (*arg != NUL)
1825 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
1826 		/* skip */ ;
1827     }
1828     xp->xp_pattern = arg;
1829 }
1830 
1831 /*
1832  * Return TRUE if "pat" matches "text".
1833  * Does not use 'cpo' and always uses 'magic'.
1834  */
1835     int
1836 pattern_match(char_u *pat, char_u *text, int ic)
1837 {
1838     int		matches = FALSE;
1839     char_u	*save_cpo;
1840     regmatch_T	regmatch;
1841 
1842     // avoid 'l' flag in 'cpoptions'
1843     save_cpo = p_cpo;
1844     p_cpo = (char_u *)"";
1845     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1846     if (regmatch.regprog != NULL)
1847     {
1848 	regmatch.rm_ic = ic;
1849 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
1850 	vim_regfree(regmatch.regprog);
1851     }
1852     p_cpo = save_cpo;
1853     return matches;
1854 }
1855 
1856 /*
1857  * Handle a name followed by "(".  Both for just "name(arg)" and for
1858  * "expr->name(arg)".
1859  * Returns OK or FAIL.
1860  */
1861     static int
1862 eval_func(
1863 	char_u	    **arg,	// points to "(", will be advanced
1864 	evalarg_T   *evalarg,
1865 	char_u	    *name,
1866 	int	    name_len,
1867 	typval_T    *rettv,
1868 	int	    flags,
1869 	typval_T    *basetv)	// "expr" for "expr->name(arg)"
1870 {
1871     int		evaluate = flags & EVAL_EVALUATE;
1872     char_u	*s = name;
1873     int		len = name_len;
1874     partial_T	*partial;
1875     int		ret = OK;
1876 
1877     if (!evaluate)
1878 	check_vars(s, len);
1879 
1880     // If "s" is the name of a variable of type VAR_FUNC
1881     // use its contents.
1882     s = deref_func_name(s, &len, &partial, !evaluate);
1883 
1884     // Need to make a copy, in case evaluating the arguments makes
1885     // the name invalid.
1886     s = vim_strsave(s);
1887     if (s == NULL || (flags & EVAL_CONSTANT))
1888 	ret = FAIL;
1889     else
1890     {
1891 	funcexe_T funcexe;
1892 
1893 	// Invoke the function.
1894 	CLEAR_FIELD(funcexe);
1895 	funcexe.firstline = curwin->w_cursor.lnum;
1896 	funcexe.lastline = curwin->w_cursor.lnum;
1897 	funcexe.evaluate = evaluate;
1898 	funcexe.partial = partial;
1899 	funcexe.basetv = basetv;
1900 	ret = get_func_tv(s, len, rettv, arg, evalarg, &funcexe);
1901     }
1902     vim_free(s);
1903 
1904     // If evaluate is FALSE rettv->v_type was not set in
1905     // get_func_tv, but it's needed in handle_subscript() to parse
1906     // what follows. So set it here.
1907     if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
1908     {
1909 	rettv->vval.v_string = NULL;
1910 	rettv->v_type = VAR_FUNC;
1911     }
1912 
1913     // Stop the expression evaluation when immediately
1914     // aborting on error, or when an interrupt occurred or
1915     // an exception was thrown but not caught.
1916     if (evaluate && aborting())
1917     {
1918 	if (ret == OK)
1919 	    clear_tv(rettv);
1920 	ret = FAIL;
1921     }
1922     return ret;
1923 }
1924 
1925 /*
1926  * If inside Vim9 script, "arg" points to the end of a line (ignoring a #
1927  * comment) and there is a next line, return the next line (skipping blanks)
1928  * and set "getnext".
1929  * Otherwise just return "arg" unmodified and set "getnext" to FALSE.
1930  * "arg" must point somewhere inside a line, not at the start.
1931  */
1932     char_u *
1933 eval_next_non_blank(char_u *arg, evalarg_T *evalarg, int *getnext)
1934 {
1935     char_u *p = skipwhite(arg);
1936 
1937     *getnext = FALSE;
1938     if (in_vim9script()
1939 	    && evalarg != NULL
1940 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL)
1941 	    && (*p == NUL || (VIM_ISWHITE(p[-1]) && vim9_comment_start(p))))
1942     {
1943 	char_u *next;
1944 
1945 	if (evalarg->eval_cookie != NULL)
1946 	    next = getline_peek(evalarg->eval_getline, evalarg->eval_cookie);
1947 	else
1948 	    next = peek_next_line_from_context(evalarg->eval_cctx);
1949 
1950 	if (next != NULL)
1951 	{
1952 	    *getnext = TRUE;
1953 	    return skipwhite(next);
1954 	}
1955     }
1956     return p;
1957 }
1958 
1959 /*
1960  * To be called after eval_next_non_blank() sets "getnext" to TRUE.
1961  */
1962     char_u *
1963 eval_next_line(evalarg_T *evalarg)
1964 {
1965     garray_T	*gap = &evalarg->eval_ga;
1966     char_u	*line;
1967 
1968     if (evalarg->eval_cookie != NULL)
1969 	line = evalarg->eval_getline(0, evalarg->eval_cookie, 0, TRUE);
1970     else
1971 	line = next_line_from_context(evalarg->eval_cctx, TRUE);
1972     ++evalarg->eval_break_count;
1973     if (gap->ga_itemsize > 0 && ga_grow(gap, 1) == OK)
1974     {
1975 	// Going to concatenate the lines after parsing.
1976 	((char_u **)gap->ga_data)[gap->ga_len] = line;
1977 	++gap->ga_len;
1978     }
1979     else if (evalarg->eval_cookie != NULL)
1980     {
1981 	vim_free(evalarg->eval_tofree);
1982 	evalarg->eval_tofree = line;
1983     }
1984     return skipwhite(line);
1985 }
1986 
1987 /*
1988  * Call eval_next_non_blank() and get the next line if needed.
1989  */
1990     char_u *
1991 skipwhite_and_linebreak(char_u *arg, evalarg_T *evalarg)
1992 {
1993     int	    getnext;
1994     char_u  *p = skipwhite(arg);
1995 
1996     if (evalarg == NULL)
1997 	return skipwhite(arg);
1998     eval_next_non_blank(p, evalarg, &getnext);
1999     if (getnext)
2000 	return eval_next_line(evalarg);
2001     return p;
2002 }
2003 
2004 /*
2005  * After using "evalarg" filled from "eap": free the memory.
2006  */
2007     void
2008 clear_evalarg(evalarg_T *evalarg, exarg_T *eap)
2009 {
2010     if (evalarg != NULL)
2011     {
2012 	if (evalarg->eval_tofree != NULL)
2013 	{
2014 	    if (eap != NULL)
2015 	    {
2016 		// We may need to keep the original command line, e.g. for
2017 		// ":let" it has the variable names.  But we may also need the
2018 		// new one, "nextcmd" points into it.  Keep both.
2019 		vim_free(eap->cmdline_tofree);
2020 		eap->cmdline_tofree = *eap->cmdlinep;
2021 		*eap->cmdlinep = evalarg->eval_tofree;
2022 	    }
2023 	    else
2024 		vim_free(evalarg->eval_tofree);
2025 	    evalarg->eval_tofree = NULL;
2026 	}
2027 
2028 	vim_free(evalarg->eval_tofree_lambda);
2029 	evalarg->eval_tofree_lambda = NULL;
2030     }
2031 }
2032 
2033 /*
2034  * The "evaluate" argument: When FALSE, the argument is only parsed but not
2035  * executed.  The function may return OK, but the rettv will be of type
2036  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
2037  */
2038 
2039 /*
2040  * Handle zero level expression.
2041  * This calls eval1() and handles error message and nextcmd.
2042  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
2043  * Note: "rettv.v_lock" is not set.
2044  * "evalarg" can be NULL, EVALARG_EVALUATE or a pointer.
2045  * Return OK or FAIL.
2046  */
2047     int
2048 eval0(
2049     char_u	*arg,
2050     typval_T	*rettv,
2051     exarg_T	*eap,
2052     evalarg_T	*evalarg)
2053 {
2054     int		ret;
2055     char_u	*p;
2056     int		did_emsg_before = did_emsg;
2057     int		called_emsg_before = called_emsg;
2058     int		flags = evalarg == NULL ? 0 : evalarg->eval_flags;
2059 
2060     p = skipwhite(arg);
2061     ret = eval1(&p, rettv, evalarg);
2062     p = skipwhite(p);
2063 
2064     if (ret == FAIL || !ends_excmd2(arg, p))
2065     {
2066 	if (ret != FAIL)
2067 	    clear_tv(rettv);
2068 	/*
2069 	 * Report the invalid expression unless the expression evaluation has
2070 	 * been cancelled due to an aborting error, an interrupt, or an
2071 	 * exception, or we already gave a more specific error.
2072 	 * Also check called_emsg for when using assert_fails().
2073 	 */
2074 	if (!aborting()
2075 		&& did_emsg == did_emsg_before
2076 		&& called_emsg == called_emsg_before
2077 		&& (flags & EVAL_CONSTANT) == 0)
2078 	    semsg(_(e_invexpr2), arg);
2079 	ret = FAIL;
2080     }
2081 
2082     if (eap != NULL)
2083 	eap->nextcmd = check_nextcmd(p);
2084 
2085     return ret;
2086 }
2087 
2088 /*
2089  * Handle top level expression:
2090  *	expr2 ? expr1 : expr1
2091  *
2092  * "arg" must point to the first non-white of the expression.
2093  * "arg" is advanced to just after the recognized expression.
2094  *
2095  * Note: "rettv.v_lock" is not set.
2096  *
2097  * Return OK or FAIL.
2098  */
2099     int
2100 eval1(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2101 {
2102     char_u  *p;
2103     int	    getnext;
2104 
2105     /*
2106      * Get the first variable.
2107      */
2108     if (eval2(arg, rettv, evalarg) == FAIL)
2109 	return FAIL;
2110 
2111     p = eval_next_non_blank(*arg, evalarg, &getnext);
2112     if (*p == '?')
2113     {
2114 	int		result;
2115 	typval_T	var2;
2116 	evalarg_T	*evalarg_used = evalarg;
2117 	evalarg_T	local_evalarg;
2118 	int		orig_flags;
2119 	int		evaluate;
2120 
2121 	if (evalarg == NULL)
2122 	{
2123 	    CLEAR_FIELD(local_evalarg);
2124 	    evalarg_used = &local_evalarg;
2125 	}
2126 	orig_flags = evalarg_used->eval_flags;
2127 	evaluate = evalarg_used->eval_flags & EVAL_EVALUATE;
2128 
2129 	if (getnext)
2130 	    *arg = eval_next_line(evalarg_used);
2131 	else
2132 	{
2133 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2134 	    {
2135 		error_white_both(p, 1);
2136 		clear_tv(rettv);
2137 		return FAIL;
2138 	    }
2139 	    *arg = p;
2140 	}
2141 
2142 	result = FALSE;
2143 	if (evaluate)
2144 	{
2145 	    int		error = FALSE;
2146 
2147 	    if (in_vim9script())
2148 		result = tv2bool(rettv);
2149 	    else if (tv_get_number_chk(rettv, &error) != 0)
2150 		result = TRUE;
2151 	    clear_tv(rettv);
2152 	    if (error)
2153 		return FAIL;
2154 	}
2155 
2156 	/*
2157 	 * Get the second variable.  Recursive!
2158 	 */
2159 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[1]))
2160 	{
2161 	    error_white_both(p, 1);
2162 	    clear_tv(rettv);
2163 	    return FAIL;
2164 	}
2165 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2166 	evalarg_used->eval_flags = result ? orig_flags
2167 						 : orig_flags & ~EVAL_EVALUATE;
2168 	if (eval1(arg, rettv, evalarg_used) == FAIL)
2169 	    return FAIL;
2170 
2171 	/*
2172 	 * Check for the ":".
2173 	 */
2174 	p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2175 	if (*p != ':')
2176 	{
2177 	    emsg(_(e_missing_colon));
2178 	    if (evaluate && result)
2179 		clear_tv(rettv);
2180 	    return FAIL;
2181 	}
2182 	if (getnext)
2183 	    *arg = eval_next_line(evalarg_used);
2184 	else
2185 	{
2186 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2187 	    {
2188 		error_white_both(p, 1);
2189 		clear_tv(rettv);
2190 		return FAIL;
2191 	    }
2192 	    *arg = p;
2193 	}
2194 
2195 	/*
2196 	 * Get the third variable.  Recursive!
2197 	 */
2198 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[1]))
2199 	{
2200 	    error_white_both(p, 1);
2201 	    clear_tv(rettv);
2202 	    return FAIL;
2203 	}
2204 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2205 	evalarg_used->eval_flags = !result ? orig_flags
2206 						 : orig_flags & ~EVAL_EVALUATE;
2207 	if (eval1(arg, &var2, evalarg_used) == FAIL)
2208 	{
2209 	    if (evaluate && result)
2210 		clear_tv(rettv);
2211 	    return FAIL;
2212 	}
2213 	if (evaluate && !result)
2214 	    *rettv = var2;
2215 
2216 	if (evalarg == NULL)
2217 	    clear_evalarg(&local_evalarg, NULL);
2218 	else
2219 	    evalarg->eval_flags = orig_flags;
2220     }
2221 
2222     return OK;
2223 }
2224 
2225 /*
2226  * Handle first level expression:
2227  *	expr2 || expr2 || expr2	    logical OR
2228  *
2229  * "arg" must point to the first non-white of the expression.
2230  * "arg" is advanced to just after the recognized expression.
2231  *
2232  * Return OK or FAIL.
2233  */
2234     static int
2235 eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2236 {
2237     char_u	*p;
2238     int		getnext;
2239 
2240     /*
2241      * Get the first variable.
2242      */
2243     if (eval3(arg, rettv, evalarg) == FAIL)
2244 	return FAIL;
2245 
2246     /*
2247      * Handle the  "||" operator.
2248      */
2249     p = eval_next_non_blank(*arg, evalarg, &getnext);
2250     if (p[0] == '|' && p[1] == '|')
2251     {
2252 	evalarg_T   *evalarg_used = evalarg;
2253 	evalarg_T   local_evalarg;
2254 	int	    evaluate;
2255 	int	    orig_flags;
2256 	long	    result = FALSE;
2257 	typval_T    var2;
2258 	int	    error;
2259 	int	    vim9script = in_vim9script();
2260 
2261 	if (evalarg == NULL)
2262 	{
2263 	    CLEAR_FIELD(local_evalarg);
2264 	    evalarg_used = &local_evalarg;
2265 	}
2266 	orig_flags = evalarg_used->eval_flags;
2267 	evaluate = orig_flags & EVAL_EVALUATE;
2268 	if (evaluate)
2269 	{
2270 	    if (vim9script)
2271 	    {
2272 		result = tv2bool(rettv);
2273 	    }
2274 	    else
2275 	    {
2276 		error = FALSE;
2277 		if (tv_get_number_chk(rettv, &error) != 0)
2278 		    result = TRUE;
2279 		clear_tv(rettv);
2280 		if (error)
2281 		    return FAIL;
2282 	    }
2283 	}
2284 
2285 	/*
2286 	 * Repeat until there is no following "||".
2287 	 */
2288 	while (p[0] == '|' && p[1] == '|')
2289 	{
2290 	    if (getnext)
2291 		*arg = eval_next_line(evalarg_used);
2292 	    else
2293 	    {
2294 		if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2295 		{
2296 		    error_white_both(p, 2);
2297 		    clear_tv(rettv);
2298 		    return FAIL;
2299 		}
2300 		*arg = p;
2301 	    }
2302 
2303 	    /*
2304 	     * Get the second variable.
2305 	     */
2306 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2307 	    {
2308 		error_white_both(p, 2);
2309 		clear_tv(rettv);
2310 		return FAIL;
2311 	    }
2312 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2313 	    evalarg_used->eval_flags = !result ? orig_flags
2314 						 : orig_flags & ~EVAL_EVALUATE;
2315 	    if (eval3(arg, &var2, evalarg_used) == FAIL)
2316 		return FAIL;
2317 
2318 	    /*
2319 	     * Compute the result.
2320 	     */
2321 	    if (evaluate && !result)
2322 	    {
2323 		if (vim9script)
2324 		{
2325 		    clear_tv(rettv);
2326 		    *rettv = var2;
2327 		    result = tv2bool(rettv);
2328 		}
2329 		else
2330 		{
2331 		    if (tv_get_number_chk(&var2, &error) != 0)
2332 			result = TRUE;
2333 		    clear_tv(&var2);
2334 		    if (error)
2335 			return FAIL;
2336 		}
2337 	    }
2338 	    if (evaluate && !vim9script)
2339 	    {
2340 		rettv->v_type = VAR_NUMBER;
2341 		rettv->vval.v_number = result;
2342 	    }
2343 
2344 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2345 	}
2346 
2347 	if (evalarg == NULL)
2348 	    clear_evalarg(&local_evalarg, NULL);
2349 	else
2350 	    evalarg->eval_flags = orig_flags;
2351     }
2352 
2353     return OK;
2354 }
2355 
2356 /*
2357  * Handle second level expression:
2358  *	expr3 && expr3 && expr3	    logical AND
2359  *
2360  * "arg" must point to the first non-white of the expression.
2361  * "arg" is advanced to just after the recognized expression.
2362  *
2363  * Return OK or FAIL.
2364  */
2365     static int
2366 eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2367 {
2368     char_u	*p;
2369     int		getnext;
2370 
2371     /*
2372      * Get the first variable.
2373      */
2374     if (eval4(arg, rettv, evalarg) == FAIL)
2375 	return FAIL;
2376 
2377     /*
2378      * Handle the "&&" operator.
2379      */
2380     p = eval_next_non_blank(*arg, evalarg, &getnext);
2381     if (p[0] == '&' && p[1] == '&')
2382     {
2383 	evalarg_T   *evalarg_used = evalarg;
2384 	evalarg_T   local_evalarg;
2385 	int	    orig_flags;
2386 	int	    evaluate;
2387 	long	    result = TRUE;
2388 	typval_T    var2;
2389 	int	    error;
2390 	int	    vim9script = in_vim9script();
2391 
2392 	if (evalarg == NULL)
2393 	{
2394 	    CLEAR_FIELD(local_evalarg);
2395 	    evalarg_used = &local_evalarg;
2396 	}
2397 	orig_flags = evalarg_used->eval_flags;
2398 	evaluate = orig_flags & EVAL_EVALUATE;
2399 	if (evaluate)
2400 	{
2401 	    if (vim9script)
2402 	    {
2403 		result = tv2bool(rettv);
2404 	    }
2405 	    else
2406 	    {
2407 		error = FALSE;
2408 		if (tv_get_number_chk(rettv, &error) == 0)
2409 		    result = FALSE;
2410 		clear_tv(rettv);
2411 		if (error)
2412 		    return FAIL;
2413 	    }
2414 	}
2415 
2416 	/*
2417 	 * Repeat until there is no following "&&".
2418 	 */
2419 	while (p[0] == '&' && p[1] == '&')
2420 	{
2421 	    if (getnext)
2422 		*arg = eval_next_line(evalarg_used);
2423 	    else
2424 	    {
2425 		if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2426 		{
2427 		    error_white_both(p, 2);
2428 		    clear_tv(rettv);
2429 		    return FAIL;
2430 		}
2431 		*arg = p;
2432 	    }
2433 
2434 	    /*
2435 	     * Get the second variable.
2436 	     */
2437 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2438 	    {
2439 		error_white_both(p, 2);
2440 		clear_tv(rettv);
2441 		return FAIL;
2442 	    }
2443 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2444 	    evalarg_used->eval_flags = result ? orig_flags
2445 						 : orig_flags & ~EVAL_EVALUATE;
2446 	    if (eval4(arg, &var2, evalarg_used) == FAIL)
2447 		return FAIL;
2448 
2449 	    /*
2450 	     * Compute the result.
2451 	     */
2452 	    if (evaluate && result)
2453 	    {
2454 		if (vim9script)
2455 		{
2456 		    clear_tv(rettv);
2457 		    *rettv = var2;
2458 		    result = tv2bool(rettv);
2459 		}
2460 		else
2461 		{
2462 		    if (tv_get_number_chk(&var2, &error) == 0)
2463 			result = FALSE;
2464 		    clear_tv(&var2);
2465 		    if (error)
2466 			return FAIL;
2467 		}
2468 	    }
2469 	    if (evaluate && !vim9script)
2470 	    {
2471 		rettv->v_type = VAR_NUMBER;
2472 		rettv->vval.v_number = result;
2473 	    }
2474 
2475 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2476 	}
2477 
2478 	if (evalarg == NULL)
2479 	    clear_evalarg(&local_evalarg, NULL);
2480 	else
2481 	    evalarg->eval_flags = orig_flags;
2482     }
2483 
2484     return OK;
2485 }
2486 
2487 /*
2488  * Handle third level expression:
2489  *	var1 == var2
2490  *	var1 =~ var2
2491  *	var1 != var2
2492  *	var1 !~ var2
2493  *	var1 > var2
2494  *	var1 >= var2
2495  *	var1 < var2
2496  *	var1 <= var2
2497  *	var1 is var2
2498  *	var1 isnot var2
2499  *
2500  * "arg" must point to the first non-white of the expression.
2501  * "arg" is advanced to just after the recognized expression.
2502  *
2503  * Return OK or FAIL.
2504  */
2505     static int
2506 eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2507 {
2508     char_u	*p;
2509     int		getnext;
2510     exptype_T	type = EXPR_UNKNOWN;
2511     int		len = 2;
2512     int		type_is = FALSE;
2513 
2514     /*
2515      * Get the first variable.
2516      */
2517     if (eval5(arg, rettv, evalarg) == FAIL)
2518 	return FAIL;
2519 
2520     p = eval_next_non_blank(*arg, evalarg, &getnext);
2521     type = get_compare_type(p, &len, &type_is);
2522 
2523     /*
2524      * If there is a comparative operator, use it.
2525      */
2526     if (type != EXPR_UNKNOWN)
2527     {
2528 	typval_T    var2;
2529 	int	    ic;
2530 	int	    vim9script = in_vim9script();
2531 	int	    evaluate = evalarg == NULL
2532 				   ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2533 
2534 	if (getnext)
2535 	    *arg = eval_next_line(evalarg);
2536 	else if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2537 	{
2538 	    error_white_both(p, len);
2539 	    clear_tv(rettv);
2540 	    return FAIL;
2541 	}
2542 
2543 	if (vim9script && type_is && (p[len] == '?' || p[len] == '#'))
2544 	{
2545 	    semsg(_(e_invexpr2), p);
2546 	    clear_tv(rettv);
2547 	    return FAIL;
2548 	}
2549 
2550 	// extra question mark appended: ignore case
2551 	if (p[len] == '?')
2552 	{
2553 	    ic = TRUE;
2554 	    ++len;
2555 	}
2556 	// extra '#' appended: match case
2557 	else if (p[len] == '#')
2558 	{
2559 	    ic = FALSE;
2560 	    ++len;
2561 	}
2562 	// nothing appended: use 'ignorecase' if not in Vim script
2563 	else
2564 	    ic = vim9script ? FALSE : p_ic;
2565 
2566 	/*
2567 	 * Get the second variable.
2568 	 */
2569 	if (evaluate && vim9script && !IS_WHITE_OR_NUL(p[len]))
2570 	{
2571 	    error_white_both(p, 1);
2572 	    clear_tv(rettv);
2573 	    return FAIL;
2574 	}
2575 	*arg = skipwhite_and_linebreak(p + len, evalarg);
2576 	if (eval5(arg, &var2, evalarg) == FAIL)
2577 	{
2578 	    clear_tv(rettv);
2579 	    return FAIL;
2580 	}
2581 	if (evaluate)
2582 	{
2583 	    int ret;
2584 
2585 	    if (vim9script && check_compare_types(type, rettv, &var2) == FAIL)
2586 	    {
2587 		ret = FAIL;
2588 		clear_tv(rettv);
2589 	    }
2590 	    else
2591 		ret = typval_compare(rettv, &var2, type, ic);
2592 	    clear_tv(&var2);
2593 	    return ret;
2594 	}
2595     }
2596 
2597     return OK;
2598 }
2599 
2600     void
2601 eval_addblob(typval_T *tv1, typval_T *tv2)
2602 {
2603     blob_T  *b1 = tv1->vval.v_blob;
2604     blob_T  *b2 = tv2->vval.v_blob;
2605     blob_T  *b = blob_alloc();
2606     int	    i;
2607 
2608     if (b != NULL)
2609     {
2610 	for (i = 0; i < blob_len(b1); i++)
2611 	    ga_append(&b->bv_ga, blob_get(b1, i));
2612 	for (i = 0; i < blob_len(b2); i++)
2613 	    ga_append(&b->bv_ga, blob_get(b2, i));
2614 
2615 	clear_tv(tv1);
2616 	rettv_blob_set(tv1, b);
2617     }
2618 }
2619 
2620     int
2621 eval_addlist(typval_T *tv1, typval_T *tv2)
2622 {
2623     typval_T var3;
2624 
2625     // concatenate Lists
2626     if (list_concat(tv1->vval.v_list, tv2->vval.v_list, &var3) == FAIL)
2627     {
2628 	clear_tv(tv1);
2629 	clear_tv(tv2);
2630 	return FAIL;
2631     }
2632     clear_tv(tv1);
2633     *tv1 = var3;
2634     return OK;
2635 }
2636 
2637 /*
2638  * Handle fourth level expression:
2639  *	+	number addition
2640  *	-	number subtraction
2641  *	.	string concatenation (if script version is 1)
2642  *	..	string concatenation
2643  *
2644  * "arg" must point to the first non-white of the expression.
2645  * "arg" is advanced to just after the recognized expression.
2646  *
2647  * Return OK or FAIL.
2648  */
2649     static int
2650 eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2651 {
2652     /*
2653      * Get the first variable.
2654      */
2655     if (eval6(arg, rettv, evalarg, FALSE) == FAIL)
2656 	return FAIL;
2657 
2658     /*
2659      * Repeat computing, until no '+', '-' or '.' is following.
2660      */
2661     for (;;)
2662     {
2663 	int	    evaluate;
2664 	int	    getnext;
2665 	char_u	    *p;
2666 	int	    op;
2667 	int	    oplen;
2668 	int	    concat;
2669 	typval_T    var2;
2670 
2671 	// "." is only string concatenation when scriptversion is 1
2672 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2673 	op = *p;
2674 	concat = op == '.' && (*(p + 1) == '.' || current_sctx.sc_version < 2);
2675 	if (op != '+' && op != '-' && !concat)
2676 	    break;
2677 
2678 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2679 	oplen = (concat && p[1] == '.') ? 2 : 1;
2680 	if (getnext)
2681 	    *arg = eval_next_line(evalarg);
2682 	else
2683 	{
2684 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(**arg))
2685 	    {
2686 		error_white_both(p, oplen);
2687 		clear_tv(rettv);
2688 		return FAIL;
2689 	    }
2690 	    *arg = p;
2691 	}
2692 	if ((op != '+' || (rettv->v_type != VAR_LIST
2693 						 && rettv->v_type != VAR_BLOB))
2694 #ifdef FEAT_FLOAT
2695 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2696 #endif
2697 		)
2698 	{
2699 	    // For "list + ...", an illegal use of the first operand as
2700 	    // a number cannot be determined before evaluating the 2nd
2701 	    // operand: if this is also a list, all is ok.
2702 	    // For "something . ...", "something - ..." or "non-list + ...",
2703 	    // we know that the first operand needs to be a string or number
2704 	    // without evaluating the 2nd operand.  So check before to avoid
2705 	    // side effects after an error.
2706 	    if (evaluate && tv_get_string_chk(rettv) == NULL)
2707 	    {
2708 		clear_tv(rettv);
2709 		return FAIL;
2710 	    }
2711 	}
2712 
2713 	/*
2714 	 * Get the second variable.
2715 	 */
2716 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[oplen]))
2717 	{
2718 	    error_white_both(p, oplen);
2719 	    clear_tv(rettv);
2720 	    return FAIL;
2721 	}
2722 	*arg = skipwhite_and_linebreak(*arg + oplen, evalarg);
2723 	if (eval6(arg, &var2, evalarg, !in_vim9script() && op == '.') == FAIL)
2724 	{
2725 	    clear_tv(rettv);
2726 	    return FAIL;
2727 	}
2728 
2729 	if (evaluate)
2730 	{
2731 	    /*
2732 	     * Compute the result.
2733 	     */
2734 	    if (op == '.')
2735 	    {
2736 		char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
2737 		char_u	*s1 = tv_get_string_buf(rettv, buf1);
2738 		char_u	*s2 = NULL;
2739 
2740 		if (in_vim9script() && (var2.v_type == VAR_VOID
2741 			|| var2.v_type == VAR_CHANNEL
2742 			|| var2.v_type == VAR_JOB))
2743 		    emsg(_(e_inval_string));
2744 #ifdef FEAT_FLOAT
2745 		else if (var2.v_type == VAR_FLOAT)
2746 		{
2747 		    vim_snprintf((char *)buf2, NUMBUFLEN, "%g",
2748 							    var2.vval.v_float);
2749 		    s2 = buf2;
2750 		}
2751 #endif
2752 		else
2753 		    s2 = tv_get_string_buf_chk(&var2, buf2);
2754 		if (s2 == NULL)		// type error ?
2755 		{
2756 		    clear_tv(rettv);
2757 		    clear_tv(&var2);
2758 		    return FAIL;
2759 		}
2760 		p = concat_str(s1, s2);
2761 		clear_tv(rettv);
2762 		rettv->v_type = VAR_STRING;
2763 		rettv->vval.v_string = p;
2764 	    }
2765 	    else if (op == '+' && rettv->v_type == VAR_BLOB
2766 						   && var2.v_type == VAR_BLOB)
2767 		eval_addblob(rettv, &var2);
2768 	    else if (op == '+' && rettv->v_type == VAR_LIST
2769 						   && var2.v_type == VAR_LIST)
2770 	    {
2771 		if (eval_addlist(rettv, &var2) == FAIL)
2772 		    return FAIL;
2773 	    }
2774 	    else
2775 	    {
2776 		int		error = FALSE;
2777 		varnumber_T	n1, n2;
2778 #ifdef FEAT_FLOAT
2779 		float_T	    f1 = 0, f2 = 0;
2780 
2781 		if (rettv->v_type == VAR_FLOAT)
2782 		{
2783 		    f1 = rettv->vval.v_float;
2784 		    n1 = 0;
2785 		}
2786 		else
2787 #endif
2788 		{
2789 		    n1 = tv_get_number_chk(rettv, &error);
2790 		    if (error)
2791 		    {
2792 			// This can only happen for "list + non-list".  For
2793 			// "non-list + ..." or "something - ...", we returned
2794 			// before evaluating the 2nd operand.
2795 			clear_tv(rettv);
2796 			return FAIL;
2797 		    }
2798 #ifdef FEAT_FLOAT
2799 		    if (var2.v_type == VAR_FLOAT)
2800 			f1 = n1;
2801 #endif
2802 		}
2803 #ifdef FEAT_FLOAT
2804 		if (var2.v_type == VAR_FLOAT)
2805 		{
2806 		    f2 = var2.vval.v_float;
2807 		    n2 = 0;
2808 		}
2809 		else
2810 #endif
2811 		{
2812 		    n2 = tv_get_number_chk(&var2, &error);
2813 		    if (error)
2814 		    {
2815 			clear_tv(rettv);
2816 			clear_tv(&var2);
2817 			return FAIL;
2818 		    }
2819 #ifdef FEAT_FLOAT
2820 		    if (rettv->v_type == VAR_FLOAT)
2821 			f2 = n2;
2822 #endif
2823 		}
2824 		clear_tv(rettv);
2825 
2826 #ifdef FEAT_FLOAT
2827 		// If there is a float on either side the result is a float.
2828 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
2829 		{
2830 		    if (op == '+')
2831 			f1 = f1 + f2;
2832 		    else
2833 			f1 = f1 - f2;
2834 		    rettv->v_type = VAR_FLOAT;
2835 		    rettv->vval.v_float = f1;
2836 		}
2837 		else
2838 #endif
2839 		{
2840 		    if (op == '+')
2841 			n1 = n1 + n2;
2842 		    else
2843 			n1 = n1 - n2;
2844 		    rettv->v_type = VAR_NUMBER;
2845 		    rettv->vval.v_number = n1;
2846 		}
2847 	    }
2848 	    clear_tv(&var2);
2849 	}
2850     }
2851     return OK;
2852 }
2853 
2854 /*
2855  * Handle fifth level expression:
2856  *	*	number multiplication
2857  *	/	number division
2858  *	%	number modulo
2859  *
2860  * "arg" must point to the first non-white of the expression.
2861  * "arg" is advanced to just after the recognized expression.
2862  *
2863  * Return OK or FAIL.
2864  */
2865     static int
2866 eval6(
2867     char_u	**arg,
2868     typval_T	*rettv,
2869     evalarg_T	*evalarg,
2870     int		want_string)  // after "." operator
2871 {
2872 #ifdef FEAT_FLOAT
2873     int	    use_float = FALSE;
2874 #endif
2875 
2876     /*
2877      * Get the first variable.
2878      */
2879     if (eval7(arg, rettv, evalarg, want_string) == FAIL)
2880 	return FAIL;
2881 
2882     /*
2883      * Repeat computing, until no '*', '/' or '%' is following.
2884      */
2885     for (;;)
2886     {
2887 	int	    evaluate;
2888 	int	    getnext;
2889 	typval_T    var2;
2890 	char_u	    *p;
2891 	int	    op;
2892 	varnumber_T n1, n2;
2893 #ifdef FEAT_FLOAT
2894 	float_T	    f1, f2;
2895 #endif
2896 	int	    error;
2897 
2898 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2899 	op = *p;
2900 	if (op != '*' && op != '/' && op != '%')
2901 	    break;
2902 
2903 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2904 	if (getnext)
2905 	    *arg = eval_next_line(evalarg);
2906 	else
2907 	{
2908 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(**arg))
2909 	    {
2910 		error_white_both(p, 1);
2911 		clear_tv(rettv);
2912 		return FAIL;
2913 	    }
2914 	    *arg = p;
2915 	}
2916 
2917 #ifdef FEAT_FLOAT
2918 	f1 = 0;
2919 	f2 = 0;
2920 #endif
2921 	error = FALSE;
2922 	if (evaluate)
2923 	{
2924 #ifdef FEAT_FLOAT
2925 	    if (rettv->v_type == VAR_FLOAT)
2926 	    {
2927 		f1 = rettv->vval.v_float;
2928 		use_float = TRUE;
2929 		n1 = 0;
2930 	    }
2931 	    else
2932 #endif
2933 		n1 = tv_get_number_chk(rettv, &error);
2934 	    clear_tv(rettv);
2935 	    if (error)
2936 		return FAIL;
2937 	}
2938 	else
2939 	    n1 = 0;
2940 
2941 	/*
2942 	 * Get the second variable.
2943 	 */
2944 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[1]))
2945 	{
2946 	    error_white_both(p, 1);
2947 	    clear_tv(rettv);
2948 	    return FAIL;
2949 	}
2950 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
2951 	if (eval7(arg, &var2, evalarg, FALSE) == FAIL)
2952 	    return FAIL;
2953 
2954 	if (evaluate)
2955 	{
2956 #ifdef FEAT_FLOAT
2957 	    if (var2.v_type == VAR_FLOAT)
2958 	    {
2959 		if (!use_float)
2960 		{
2961 		    f1 = n1;
2962 		    use_float = TRUE;
2963 		}
2964 		f2 = var2.vval.v_float;
2965 		n2 = 0;
2966 	    }
2967 	    else
2968 #endif
2969 	    {
2970 		n2 = tv_get_number_chk(&var2, &error);
2971 		clear_tv(&var2);
2972 		if (error)
2973 		    return FAIL;
2974 #ifdef FEAT_FLOAT
2975 		if (use_float)
2976 		    f2 = n2;
2977 #endif
2978 	    }
2979 
2980 	    /*
2981 	     * Compute the result.
2982 	     * When either side is a float the result is a float.
2983 	     */
2984 #ifdef FEAT_FLOAT
2985 	    if (use_float)
2986 	    {
2987 		if (op == '*')
2988 		    f1 = f1 * f2;
2989 		else if (op == '/')
2990 		{
2991 # ifdef VMS
2992 		    // VMS crashes on divide by zero, work around it
2993 		    if (f2 == 0.0)
2994 		    {
2995 			if (f1 == 0)
2996 			    f1 = -1 * __F_FLT_MAX - 1L;   // similar to NaN
2997 			else if (f1 < 0)
2998 			    f1 = -1 * __F_FLT_MAX;
2999 			else
3000 			    f1 = __F_FLT_MAX;
3001 		    }
3002 		    else
3003 			f1 = f1 / f2;
3004 # else
3005 		    // We rely on the floating point library to handle divide
3006 		    // by zero to result in "inf" and not a crash.
3007 		    f1 = f1 / f2;
3008 # endif
3009 		}
3010 		else
3011 		{
3012 		    emsg(_(e_modulus));
3013 		    return FAIL;
3014 		}
3015 		rettv->v_type = VAR_FLOAT;
3016 		rettv->vval.v_float = f1;
3017 	    }
3018 	    else
3019 #endif
3020 	    {
3021 		if (op == '*')
3022 		    n1 = n1 * n2;
3023 		else if (op == '/')
3024 		    n1 = num_divide(n1, n2);
3025 		else
3026 		    n1 = num_modulus(n1, n2);
3027 
3028 		rettv->v_type = VAR_NUMBER;
3029 		rettv->vval.v_number = n1;
3030 	    }
3031 	}
3032     }
3033 
3034     return OK;
3035 }
3036 
3037 /*
3038  * Handle sixth level expression:
3039  *  number		number constant
3040  *  0zFFFFFFFF		Blob constant
3041  *  "string"		string constant
3042  *  'string'		literal string constant
3043  *  &option-name	option value
3044  *  @r			register contents
3045  *  identifier		variable value
3046  *  function()		function call
3047  *  $VAR		environment variable
3048  *  (expression)	nested expression
3049  *  [expr, expr]	List
3050  *  {arg, arg -> expr}	Lambda
3051  *  {key: val, key: val}   Dictionary
3052  *  #{key: val, key: val}  Dictionary with literal keys
3053  *
3054  *  Also handle:
3055  *  ! in front		logical NOT
3056  *  - in front		unary minus
3057  *  + in front		unary plus (ignored)
3058  *  trailing []		subscript in String or List
3059  *  trailing .name	entry in Dictionary
3060  *  trailing ->name()	method call
3061  *
3062  * "arg" must point to the first non-white of the expression.
3063  * "arg" is advanced to just after the recognized expression.
3064  *
3065  * Return OK or FAIL.
3066  */
3067     static int
3068 eval7(
3069     char_u	**arg,
3070     typval_T	*rettv,
3071     evalarg_T	*evalarg,
3072     int		want_string)	// after "." operator
3073 {
3074     int		evaluate = evalarg != NULL
3075 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3076     int		len;
3077     char_u	*s;
3078     char_u	*start_leader, *end_leader;
3079     int		ret = OK;
3080     char_u	*alias;
3081 
3082     /*
3083      * Initialise variable so that clear_tv() can't mistake this for a
3084      * string and free a string that isn't there.
3085      */
3086     rettv->v_type = VAR_UNKNOWN;
3087 
3088     /*
3089      * Skip '!', '-' and '+' characters.  They are handled later.
3090      */
3091     start_leader = *arg;
3092     while (**arg == '!' || **arg == '-' || **arg == '+')
3093 	*arg = skipwhite(*arg + 1);
3094     end_leader = *arg;
3095 
3096     if (**arg == '.' && (!isdigit(*(*arg + 1))
3097 #ifdef FEAT_FLOAT
3098 	    || current_sctx.sc_version < 2
3099 #endif
3100 	    ))
3101     {
3102 	semsg(_(e_invexpr2), *arg);
3103 	++*arg;
3104 	return FAIL;
3105     }
3106 
3107     switch (**arg)
3108     {
3109     /*
3110      * Number constant.
3111      */
3112     case '0':
3113     case '1':
3114     case '2':
3115     case '3':
3116     case '4':
3117     case '5':
3118     case '6':
3119     case '7':
3120     case '8':
3121     case '9':
3122     case '.':	ret = eval_number(arg, rettv, evaluate, want_string);
3123 
3124 		// Apply prefixed "-" and "+" now.  Matters especially when
3125 		// "->" follows.
3126 		if (ret == OK && evaluate && end_leader > start_leader
3127 						  && rettv->v_type != VAR_BLOB)
3128 		    ret = eval7_leader(rettv, TRUE, start_leader, &end_leader);
3129 		break;
3130 
3131     /*
3132      * String constant: "string".
3133      */
3134     case '"':	ret = eval_string(arg, rettv, evaluate);
3135 		break;
3136 
3137     /*
3138      * Literal string constant: 'str''ing'.
3139      */
3140     case '\'':	ret = eval_lit_string(arg, rettv, evaluate);
3141 		break;
3142 
3143     /*
3144      * List: [expr, expr]
3145      */
3146     case '[':	ret = eval_list(arg, rettv, evalarg, TRUE);
3147 		break;
3148 
3149     /*
3150      * Dictionary: #{key: val, key: val}
3151      */
3152     case '#':	if ((*arg)[1] == '{')
3153 		{
3154 		    ++*arg;
3155 		    ret = eval_dict(arg, rettv, evalarg, TRUE);
3156 		}
3157 		else
3158 		    ret = NOTDONE;
3159 		break;
3160 
3161     /*
3162      * Lambda: {arg, arg -> expr}
3163      * Dictionary: {'key': val, 'key': val}
3164      */
3165     case '{':	ret = get_lambda_tv(arg, rettv, evalarg);
3166 		if (ret == NOTDONE)
3167 		    ret = eval_dict(arg, rettv, evalarg, FALSE);
3168 		break;
3169 
3170     /*
3171      * Option value: &name
3172      */
3173     case '&':	ret = eval_option(arg, rettv, evaluate);
3174 		break;
3175 
3176     /*
3177      * Environment variable: $VAR.
3178      */
3179     case '$':	ret = eval_env_var(arg, rettv, evaluate);
3180 		break;
3181 
3182     /*
3183      * Register contents: @r.
3184      */
3185     case '@':	++*arg;
3186 		if (evaluate)
3187 		{
3188 		    rettv->v_type = VAR_STRING;
3189 		    rettv->vval.v_string = get_reg_contents(**arg,
3190 							    GREG_EXPR_SRC);
3191 		}
3192 		if (**arg != NUL)
3193 		    ++*arg;
3194 		break;
3195 
3196     /*
3197      * nested expression: (expression).
3198      */
3199     case '(':	{
3200 		    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3201 		    ret = eval1(arg, rettv, evalarg);	// recursive!
3202 
3203 		    *arg = skipwhite_and_linebreak(*arg, evalarg);
3204 		    if (**arg == ')')
3205 			++*arg;
3206 		    else if (ret == OK)
3207 		    {
3208 			emsg(_(e_missing_close));
3209 			clear_tv(rettv);
3210 			ret = FAIL;
3211 		    }
3212 		}
3213 		break;
3214 
3215     default:	ret = NOTDONE;
3216 		break;
3217     }
3218 
3219     if (ret == NOTDONE)
3220     {
3221 	/*
3222 	 * Must be a variable or function name.
3223 	 * Can also be a curly-braces kind of name: {expr}.
3224 	 */
3225 	s = *arg;
3226 	len = get_name_len(arg, &alias, evaluate, TRUE);
3227 	if (alias != NULL)
3228 	    s = alias;
3229 
3230 	if (len <= 0)
3231 	    ret = FAIL;
3232 	else
3233 	{
3234 	    int	    flags = evalarg == NULL ? 0 : evalarg->eval_flags;
3235 
3236 	    if ((in_vim9script() ? **arg : *skipwhite(*arg)) == '(')
3237 	    {
3238 		// "name(..."  recursive!
3239 		*arg = skipwhite(*arg);
3240 		ret = eval_func(arg, evalarg, s, len, rettv, flags, NULL);
3241 	    }
3242 	    else if (flags & EVAL_CONSTANT)
3243 		ret = FAIL;
3244 	    else if (evaluate)
3245 	    {
3246 		// get the value of "true", "false" or a variable
3247 		if (len == 4 && in_vim9script() && STRNCMP(s, "true", 4) == 0)
3248 		{
3249 		    rettv->v_type = VAR_BOOL;
3250 		    rettv->vval.v_number = VVAL_TRUE;
3251 		    ret = OK;
3252 		}
3253 		else if (len == 5 && in_vim9script()
3254 						&& STRNCMP(s, "false", 4) == 0)
3255 		{
3256 		    rettv->v_type = VAR_BOOL;
3257 		    rettv->vval.v_number = VVAL_FALSE;
3258 		    ret = OK;
3259 		}
3260 		else
3261 		    ret = eval_variable(s, len, rettv, NULL, TRUE, FALSE);
3262 	    }
3263 	    else
3264 	    {
3265 		// skip the name
3266 		check_vars(s, len);
3267 		ret = OK;
3268 	    }
3269 	}
3270 	vim_free(alias);
3271     }
3272 
3273     // Handle following '[', '(' and '.' for expr[expr], expr.name,
3274     // expr(expr), expr->name(expr)
3275     if (ret == OK)
3276 	ret = handle_subscript(arg, rettv, evalarg, TRUE);
3277 
3278     /*
3279      * Apply logical NOT and unary '-', from right to left, ignore '+'.
3280      */
3281     if (ret == OK && evaluate && end_leader > start_leader)
3282 	ret = eval7_leader(rettv, FALSE, start_leader, &end_leader);
3283     return ret;
3284 }
3285 
3286 /*
3287  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
3288  * When "numeric_only" is TRUE only handle "+" and "-".
3289  * Adjusts "end_leaderp" until it is at "start_leader".
3290  */
3291     static int
3292 eval7_leader(
3293 	typval_T    *rettv,
3294 	int	    numeric_only,
3295 	char_u	    *start_leader,
3296 	char_u	    **end_leaderp)
3297 {
3298     char_u	*end_leader = *end_leaderp;
3299     int		ret = OK;
3300     int		error = FALSE;
3301     varnumber_T val = 0;
3302     vartype_T	type = rettv->v_type;
3303 #ifdef FEAT_FLOAT
3304     float_T	    f = 0.0;
3305 
3306     if (rettv->v_type == VAR_FLOAT)
3307 	f = rettv->vval.v_float;
3308     else
3309 #endif
3310 	if (in_vim9script() && end_leader[-1] == '!')
3311 	    val = tv2bool(rettv);
3312 	else
3313 	    val = tv_get_number_chk(rettv, &error);
3314     if (error)
3315     {
3316 	clear_tv(rettv);
3317 	ret = FAIL;
3318     }
3319     else
3320     {
3321 	while (end_leader > start_leader)
3322 	{
3323 	    --end_leader;
3324 	    if (*end_leader == '!')
3325 	    {
3326 		if (numeric_only)
3327 		{
3328 		    ++end_leader;
3329 		    break;
3330 		}
3331 #ifdef FEAT_FLOAT
3332 		if (rettv->v_type == VAR_FLOAT)
3333 		    f = !f;
3334 		else
3335 #endif
3336 		{
3337 		    val = !val;
3338 		    type = VAR_BOOL;
3339 		}
3340 	    }
3341 	    else if (*end_leader == '-')
3342 	    {
3343 #ifdef FEAT_FLOAT
3344 		if (rettv->v_type == VAR_FLOAT)
3345 		    f = -f;
3346 		else
3347 #endif
3348 		{
3349 		    val = -val;
3350 		    type = VAR_NUMBER;
3351 		}
3352 	    }
3353 	}
3354 #ifdef FEAT_FLOAT
3355 	if (rettv->v_type == VAR_FLOAT)
3356 	{
3357 	    clear_tv(rettv);
3358 	    rettv->vval.v_float = f;
3359 	}
3360 	else
3361 #endif
3362 	{
3363 	    clear_tv(rettv);
3364 	    if (in_vim9script())
3365 		rettv->v_type = type;
3366 	    else
3367 		rettv->v_type = VAR_NUMBER;
3368 	    rettv->vval.v_number = val;
3369 	}
3370     }
3371     *end_leaderp = end_leader;
3372     return ret;
3373 }
3374 
3375 /*
3376  * Call the function referred to in "rettv".
3377  */
3378     static int
3379 call_func_rettv(
3380 	char_u	    **arg,
3381 	evalarg_T   *evalarg,
3382 	typval_T    *rettv,
3383 	int	    evaluate,
3384 	dict_T	    *selfdict,
3385 	typval_T    *basetv)
3386 {
3387     partial_T	*pt = NULL;
3388     funcexe_T	funcexe;
3389     typval_T	functv;
3390     char_u	*s;
3391     int		ret;
3392 
3393     // need to copy the funcref so that we can clear rettv
3394     if (evaluate)
3395     {
3396 	functv = *rettv;
3397 	rettv->v_type = VAR_UNKNOWN;
3398 
3399 	// Invoke the function.  Recursive!
3400 	if (functv.v_type == VAR_PARTIAL)
3401 	{
3402 	    pt = functv.vval.v_partial;
3403 	    s = partial_name(pt);
3404 	}
3405 	else
3406 	    s = functv.vval.v_string;
3407     }
3408     else
3409 	s = (char_u *)"";
3410 
3411     CLEAR_FIELD(funcexe);
3412     funcexe.firstline = curwin->w_cursor.lnum;
3413     funcexe.lastline = curwin->w_cursor.lnum;
3414     funcexe.evaluate = evaluate;
3415     funcexe.partial = pt;
3416     funcexe.selfdict = selfdict;
3417     funcexe.basetv = basetv;
3418     ret = get_func_tv(s, -1, rettv, arg, evalarg, &funcexe);
3419 
3420     // Clear the funcref afterwards, so that deleting it while
3421     // evaluating the arguments is possible (see test55).
3422     if (evaluate)
3423 	clear_tv(&functv);
3424 
3425     return ret;
3426 }
3427 
3428 /*
3429  * Evaluate "->method()".
3430  * "*arg" points to the '-'.
3431  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3432  */
3433     static int
3434 eval_lambda(
3435     char_u	**arg,
3436     typval_T	*rettv,
3437     evalarg_T	*evalarg,
3438     int		verbose)	// give error messages
3439 {
3440     int		evaluate = evalarg != NULL
3441 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3442     typval_T	base = *rettv;
3443     int		ret;
3444 
3445     // Skip over the ->.
3446     *arg += 2;
3447     rettv->v_type = VAR_UNKNOWN;
3448 
3449     ret = get_lambda_tv(arg, rettv, evalarg);
3450     if (ret != OK)
3451 	return FAIL;
3452     else if (**arg != '(')
3453     {
3454 	if (verbose)
3455 	{
3456 	    if (*skipwhite(*arg) == '(')
3457 		emsg(_(e_nowhitespace));
3458 	    else
3459 		semsg(_(e_missing_paren), "lambda");
3460 	}
3461 	clear_tv(rettv);
3462 	ret = FAIL;
3463     }
3464     else
3465 	ret = call_func_rettv(arg, evalarg, rettv, evaluate, NULL, &base);
3466 
3467     // Clear the funcref afterwards, so that deleting it while
3468     // evaluating the arguments is possible (see test55).
3469     if (evaluate)
3470 	clear_tv(&base);
3471 
3472     return ret;
3473 }
3474 
3475 /*
3476  * Evaluate "->method()".
3477  * "*arg" points to the '-'.
3478  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3479  */
3480     static int
3481 eval_method(
3482     char_u	**arg,
3483     typval_T	*rettv,
3484     evalarg_T	*evalarg,
3485     int		verbose)	// give error messages
3486 {
3487     char_u	*name;
3488     long	len;
3489     char_u	*alias;
3490     typval_T	base = *rettv;
3491     int		ret;
3492     int		evaluate = evalarg != NULL
3493 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3494 
3495     // Skip over the ->.
3496     *arg += 2;
3497     rettv->v_type = VAR_UNKNOWN;
3498 
3499     name = *arg;
3500     len = get_name_len(arg, &alias, evaluate, TRUE);
3501     if (alias != NULL)
3502 	name = alias;
3503 
3504     if (len <= 0)
3505     {
3506 	if (verbose)
3507 	    emsg(_("E260: Missing name after ->"));
3508 	ret = FAIL;
3509     }
3510     else
3511     {
3512 	*arg = skipwhite(*arg);
3513 	if (**arg != '(')
3514 	{
3515 	    if (verbose)
3516 		semsg(_(e_missing_paren), name);
3517 	    ret = FAIL;
3518 	}
3519 	else if (VIM_ISWHITE((*arg)[-1]))
3520 	{
3521 	    if (verbose)
3522 		emsg(_(e_nowhitespace));
3523 	    ret = FAIL;
3524 	}
3525 	else
3526 	    ret = eval_func(arg, evalarg, name, len, rettv,
3527 					  evaluate ? EVAL_EVALUATE : 0, &base);
3528     }
3529 
3530     // Clear the funcref afterwards, so that deleting it while
3531     // evaluating the arguments is possible (see test55).
3532     if (evaluate)
3533 	clear_tv(&base);
3534 
3535     return ret;
3536 }
3537 
3538 /*
3539  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
3540  * "*arg" points to the '[' or '.'.
3541  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
3542  */
3543     static int
3544 eval_index(
3545     char_u	**arg,
3546     typval_T	*rettv,
3547     evalarg_T	*evalarg,
3548     int		verbose)	// give error messages
3549 {
3550     int		evaluate = evalarg != NULL
3551 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3552     int		empty1 = FALSE, empty2 = FALSE;
3553     typval_T	var1, var2;
3554     int		range = FALSE;
3555     char_u	*key = NULL;
3556     int		keylen = -1;
3557 
3558     if (check_can_index(rettv, evaluate, verbose) == FAIL)
3559 	return FAIL;
3560 
3561     init_tv(&var1);
3562     init_tv(&var2);
3563     if (**arg == '.')
3564     {
3565 	/*
3566 	 * dict.name
3567 	 */
3568 	key = *arg + 1;
3569 	for (keylen = 0; eval_isdictc(key[keylen]); ++keylen)
3570 	    ;
3571 	if (keylen == 0)
3572 	    return FAIL;
3573 	*arg = skipwhite(key + keylen);
3574     }
3575     else
3576     {
3577 	/*
3578 	 * something[idx]
3579 	 *
3580 	 * Get the (first) variable from inside the [].
3581 	 */
3582 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3583 	if (**arg == ':')
3584 	    empty1 = TRUE;
3585 	else if (eval1(arg, &var1, evalarg) == FAIL)	// recursive!
3586 	    return FAIL;
3587 	else if (evaluate && tv_get_string_chk(&var1) == NULL)
3588 	{
3589 	    // not a number or string
3590 	    clear_tv(&var1);
3591 	    return FAIL;
3592 	}
3593 
3594 	/*
3595 	 * Get the second variable from inside the [:].
3596 	 */
3597 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3598 	if (**arg == ':')
3599 	{
3600 	    range = TRUE;
3601 	    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3602 	    if (**arg == ']')
3603 		empty2 = TRUE;
3604 	    else if (eval1(arg, &var2, evalarg) == FAIL)	// recursive!
3605 	    {
3606 		if (!empty1)
3607 		    clear_tv(&var1);
3608 		return FAIL;
3609 	    }
3610 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
3611 	    {
3612 		// not a number or string
3613 		if (!empty1)
3614 		    clear_tv(&var1);
3615 		clear_tv(&var2);
3616 		return FAIL;
3617 	    }
3618 	}
3619 
3620 	// Check for the ']'.
3621 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3622 	if (**arg != ']')
3623 	{
3624 	    if (verbose)
3625 		emsg(_(e_missbrac));
3626 	    clear_tv(&var1);
3627 	    if (range)
3628 		clear_tv(&var2);
3629 	    return FAIL;
3630 	}
3631 	*arg = *arg + 1;	// skip over the ']'
3632     }
3633 
3634     if (evaluate)
3635     {
3636 	int res = eval_index_inner(rettv, range,
3637 		empty1 ? NULL : &var1, empty2 ? NULL : &var2,
3638 		key, keylen, verbose);
3639 	if (!empty1)
3640 	    clear_tv(&var1);
3641 	if (range)
3642 	    clear_tv(&var2);
3643 	return res;
3644     }
3645     return OK;
3646 }
3647 
3648 /*
3649  * Check if "rettv" can have an [index] or [sli:ce]
3650  */
3651     int
3652 check_can_index(typval_T *rettv, int evaluate, int verbose)
3653 {
3654     switch (rettv->v_type)
3655     {
3656 	case VAR_FUNC:
3657 	case VAR_PARTIAL:
3658 	    if (verbose)
3659 		emsg(_("E695: Cannot index a Funcref"));
3660 	    return FAIL;
3661 	case VAR_FLOAT:
3662 #ifdef FEAT_FLOAT
3663 	    if (verbose)
3664 		emsg(_(e_float_as_string));
3665 	    return FAIL;
3666 #endif
3667 	case VAR_BOOL:
3668 	case VAR_SPECIAL:
3669 	case VAR_JOB:
3670 	case VAR_CHANNEL:
3671 	    if (verbose)
3672 		emsg(_(e_cannot_index_special_variable));
3673 	    return FAIL;
3674 	case VAR_UNKNOWN:
3675 	case VAR_ANY:
3676 	case VAR_VOID:
3677 	    if (evaluate)
3678 	    {
3679 		emsg(_(e_cannot_index_special_variable));
3680 		return FAIL;
3681 	    }
3682 	    // FALLTHROUGH
3683 
3684 	case VAR_STRING:
3685 	case VAR_LIST:
3686 	case VAR_DICT:
3687 	case VAR_BLOB:
3688 	    break;
3689 	case VAR_NUMBER:
3690 	    if (in_vim9script())
3691 		emsg(_(e_cannot_index_number));
3692 	    break;
3693     }
3694     return OK;
3695 }
3696 
3697 /*
3698  * Apply index or range to "rettv".
3699  * "var1" is the first index, NULL for [:expr].
3700  * "var2" is the second index, NULL for [expr] and [expr: ]
3701  * Alternatively, "key" is not NULL, then key[keylen] is the dict index.
3702  */
3703     int
3704 eval_index_inner(
3705 	typval_T    *rettv,
3706 	int	    is_range,
3707 	typval_T    *var1,
3708 	typval_T    *var2,
3709 	char_u	    *key,
3710 	int	    keylen,
3711 	int	    verbose)
3712 {
3713     long	n1, n2 = 0;
3714     long	len;
3715 
3716     n1 = 0;
3717     if (var1 != NULL && rettv->v_type != VAR_DICT)
3718 	n1 = tv_get_number(var1);
3719 
3720     if (is_range)
3721     {
3722 	if (rettv->v_type == VAR_DICT)
3723 	{
3724 	    if (verbose)
3725 		emsg(_(e_cannot_slice_dictionary));
3726 	    return FAIL;
3727 	}
3728 	if (var2 == NULL)
3729 	    n2 = -1;
3730 	else
3731 	    n2 = tv_get_number(var2);
3732     }
3733 
3734     switch (rettv->v_type)
3735     {
3736 	case VAR_UNKNOWN:
3737 	case VAR_ANY:
3738 	case VAR_VOID:
3739 	case VAR_FUNC:
3740 	case VAR_PARTIAL:
3741 	case VAR_FLOAT:
3742 	case VAR_BOOL:
3743 	case VAR_SPECIAL:
3744 	case VAR_JOB:
3745 	case VAR_CHANNEL:
3746 	    break; // not evaluating, skipping over subscript
3747 
3748 	case VAR_NUMBER:
3749 	case VAR_STRING:
3750 	    {
3751 		char_u	*s = tv_get_string(rettv);
3752 
3753 		len = (long)STRLEN(s);
3754 		if (in_vim9script())
3755 		{
3756 		    if (is_range)
3757 			s = string_slice(s, n1, n2);
3758 		    else
3759 			s = char_from_string(s, n1);
3760 		}
3761 		else if (is_range)
3762 		{
3763 		    // The resulting variable is a substring.  If the indexes
3764 		    // are out of range the result is empty.
3765 		    if (n1 < 0)
3766 		    {
3767 			n1 = len + n1;
3768 			if (n1 < 0)
3769 			    n1 = 0;
3770 		    }
3771 		    if (n2 < 0)
3772 			n2 = len + n2;
3773 		    else if (n2 >= len)
3774 			n2 = len;
3775 		    if (n1 >= len || n2 < 0 || n1 > n2)
3776 			s = NULL;
3777 		    else
3778 			s = vim_strnsave(s + n1, n2 - n1 + 1);
3779 		}
3780 		else
3781 		{
3782 		    // The resulting variable is a string of a single
3783 		    // character.  If the index is too big or negative the
3784 		    // result is empty.
3785 		    if (n1 >= len || n1 < 0)
3786 			s = NULL;
3787 		    else
3788 			s = vim_strnsave(s + n1, 1);
3789 		}
3790 		clear_tv(rettv);
3791 		rettv->v_type = VAR_STRING;
3792 		rettv->vval.v_string = s;
3793 	    }
3794 	    break;
3795 
3796 	case VAR_BLOB:
3797 	    len = blob_len(rettv->vval.v_blob);
3798 	    if (is_range)
3799 	    {
3800 		// The resulting variable is a sub-blob.  If the indexes
3801 		// are out of range the result is empty.
3802 		if (n1 < 0)
3803 		{
3804 		    n1 = len + n1;
3805 		    if (n1 < 0)
3806 			n1 = 0;
3807 		}
3808 		if (n2 < 0)
3809 		    n2 = len + n2;
3810 		else if (n2 >= len)
3811 		    n2 = len - 1;
3812 		if (n1 >= len || n2 < 0 || n1 > n2)
3813 		{
3814 		    clear_tv(rettv);
3815 		    rettv->v_type = VAR_BLOB;
3816 		    rettv->vval.v_blob = NULL;
3817 		}
3818 		else
3819 		{
3820 		    blob_T  *blob = blob_alloc();
3821 		    long    i;
3822 
3823 		    if (blob != NULL)
3824 		    {
3825 			if (ga_grow(&blob->bv_ga, n2 - n1 + 1) == FAIL)
3826 			{
3827 			    blob_free(blob);
3828 			    return FAIL;
3829 			}
3830 			blob->bv_ga.ga_len = n2 - n1 + 1;
3831 			for (i = n1; i <= n2; i++)
3832 			    blob_set(blob, i - n1,
3833 					  blob_get(rettv->vval.v_blob, i));
3834 
3835 			clear_tv(rettv);
3836 			rettv_blob_set(rettv, blob);
3837 		    }
3838 		}
3839 	    }
3840 	    else
3841 	    {
3842 		// The resulting variable is a byte value.
3843 		// If the index is too big or negative that is an error.
3844 		if (n1 < 0)
3845 		    n1 = len + n1;
3846 		if (n1 < len && n1 >= 0)
3847 		{
3848 		    int v = blob_get(rettv->vval.v_blob, n1);
3849 
3850 		    clear_tv(rettv);
3851 		    rettv->v_type = VAR_NUMBER;
3852 		    rettv->vval.v_number = v;
3853 		}
3854 		else
3855 		    semsg(_(e_blobidx), n1);
3856 	    }
3857 	    break;
3858 
3859 	case VAR_LIST:
3860 	    if (var1 == NULL)
3861 		n1 = 0;
3862 	    if (var2 == NULL)
3863 		n2 = -1;
3864 	    if (list_slice_or_index(rettv->vval.v_list,
3865 				    is_range, n1, n2, rettv, verbose) == FAIL)
3866 		return FAIL;
3867 	    break;
3868 
3869 	case VAR_DICT:
3870 	    {
3871 		dictitem_T	*item;
3872 		typval_T	tmp;
3873 
3874 		if (key == NULL)
3875 		{
3876 		    key = tv_get_string_chk(var1);
3877 		    if (key == NULL)
3878 			return FAIL;
3879 		}
3880 
3881 		item = dict_find(rettv->vval.v_dict, key, (int)keylen);
3882 
3883 		if (item == NULL && verbose)
3884 		    semsg(_(e_dictkey), key);
3885 		if (item == NULL)
3886 		    return FAIL;
3887 
3888 		copy_tv(&item->di_tv, &tmp);
3889 		clear_tv(rettv);
3890 		*rettv = tmp;
3891 	    }
3892 	    break;
3893     }
3894     return OK;
3895 }
3896 
3897 /*
3898  * Return the function name of partial "pt".
3899  */
3900     char_u *
3901 partial_name(partial_T *pt)
3902 {
3903     if (pt->pt_name != NULL)
3904 	return pt->pt_name;
3905     if (pt->pt_func != NULL)
3906 	return pt->pt_func->uf_name;
3907     return (char_u *)"";
3908 }
3909 
3910     static void
3911 partial_free(partial_T *pt)
3912 {
3913     int i;
3914 
3915     for (i = 0; i < pt->pt_argc; ++i)
3916 	clear_tv(&pt->pt_argv[i]);
3917     vim_free(pt->pt_argv);
3918     dict_unref(pt->pt_dict);
3919     if (pt->pt_name != NULL)
3920     {
3921 	func_unref(pt->pt_name);
3922 	vim_free(pt->pt_name);
3923     }
3924     else
3925 	func_ptr_unref(pt->pt_func);
3926 
3927     if (pt->pt_funcstack != NULL)
3928     {
3929 	// Decrease the reference count for the context of a closure.  If down
3930 	// to zero free it and clear the variables on the stack.
3931 	if (--pt->pt_funcstack->fs_refcount == 0)
3932 	{
3933 	    garray_T	*gap = &pt->pt_funcstack->fs_ga;
3934 	    typval_T	*stack = gap->ga_data;
3935 
3936 	    for (i = 0; i < gap->ga_len; ++i)
3937 		clear_tv(stack + i);
3938 	    ga_clear(gap);
3939 	    vim_free(pt->pt_funcstack);
3940 	}
3941 	pt->pt_funcstack = NULL;
3942     }
3943 
3944     vim_free(pt);
3945 }
3946 
3947 /*
3948  * Unreference a closure: decrement the reference count and free it when it
3949  * becomes zero.
3950  */
3951     void
3952 partial_unref(partial_T *pt)
3953 {
3954     if (pt != NULL && --pt->pt_refcount <= 0)
3955 	partial_free(pt);
3956 }
3957 
3958 /*
3959  * Return the next (unique) copy ID.
3960  * Used for serializing nested structures.
3961  */
3962     int
3963 get_copyID(void)
3964 {
3965     current_copyID += COPYID_INC;
3966     return current_copyID;
3967 }
3968 
3969 /*
3970  * Garbage collection for lists and dictionaries.
3971  *
3972  * We use reference counts to be able to free most items right away when they
3973  * are no longer used.  But for composite items it's possible that it becomes
3974  * unused while the reference count is > 0: When there is a recursive
3975  * reference.  Example:
3976  *	:let l = [1, 2, 3]
3977  *	:let d = {9: l}
3978  *	:let l[1] = d
3979  *
3980  * Since this is quite unusual we handle this with garbage collection: every
3981  * once in a while find out which lists and dicts are not referenced from any
3982  * variable.
3983  *
3984  * Here is a good reference text about garbage collection (refers to Python
3985  * but it applies to all reference-counting mechanisms):
3986  *	http://python.ca/nas/python/gc/
3987  */
3988 
3989 /*
3990  * Do garbage collection for lists and dicts.
3991  * When "testing" is TRUE this is called from test_garbagecollect_now().
3992  * Return TRUE if some memory was freed.
3993  */
3994     int
3995 garbage_collect(int testing)
3996 {
3997     int		copyID;
3998     int		abort = FALSE;
3999     buf_T	*buf;
4000     win_T	*wp;
4001     int		did_free = FALSE;
4002     tabpage_T	*tp;
4003 
4004     if (!testing)
4005     {
4006 	// Only do this once.
4007 	want_garbage_collect = FALSE;
4008 	may_garbage_collect = FALSE;
4009 	garbage_collect_at_exit = FALSE;
4010     }
4011 
4012     // The execution stack can grow big, limit the size.
4013     if (exestack.ga_maxlen - exestack.ga_len > 500)
4014     {
4015 	size_t	new_len;
4016 	char_u	*pp;
4017 	int	n;
4018 
4019 	// Keep 150% of the current size, with a minimum of the growth size.
4020 	n = exestack.ga_len / 2;
4021 	if (n < exestack.ga_growsize)
4022 	    n = exestack.ga_growsize;
4023 
4024 	// Don't make it bigger though.
4025 	if (exestack.ga_len + n < exestack.ga_maxlen)
4026 	{
4027 	    new_len = exestack.ga_itemsize * (exestack.ga_len + n);
4028 	    pp = vim_realloc(exestack.ga_data, new_len);
4029 	    if (pp == NULL)
4030 		return FAIL;
4031 	    exestack.ga_maxlen = exestack.ga_len + n;
4032 	    exestack.ga_data = pp;
4033 	}
4034     }
4035 
4036     // We advance by two because we add one for items referenced through
4037     // previous_funccal.
4038     copyID = get_copyID();
4039 
4040     /*
4041      * 1. Go through all accessible variables and mark all lists and dicts
4042      *    with copyID.
4043      */
4044 
4045     // Don't free variables in the previous_funccal list unless they are only
4046     // referenced through previous_funccal.  This must be first, because if
4047     // the item is referenced elsewhere the funccal must not be freed.
4048     abort = abort || set_ref_in_previous_funccal(copyID);
4049 
4050     // script-local variables
4051     abort = abort || garbage_collect_scriptvars(copyID);
4052 
4053     // buffer-local variables
4054     FOR_ALL_BUFFERS(buf)
4055 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
4056 								  NULL, NULL);
4057 
4058     // window-local variables
4059     FOR_ALL_TAB_WINDOWS(tp, wp)
4060 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4061 								  NULL, NULL);
4062     if (aucmd_win != NULL)
4063 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
4064 								  NULL, NULL);
4065 #ifdef FEAT_PROP_POPUP
4066     FOR_ALL_POPUPWINS(wp)
4067 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4068 								  NULL, NULL);
4069     FOR_ALL_TABPAGES(tp)
4070 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
4071 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4072 								  NULL, NULL);
4073 #endif
4074 
4075     // tabpage-local variables
4076     FOR_ALL_TABPAGES(tp)
4077 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
4078 								  NULL, NULL);
4079     // global variables
4080     abort = abort || garbage_collect_globvars(copyID);
4081 
4082     // function-local variables
4083     abort = abort || set_ref_in_call_stack(copyID);
4084 
4085     // named functions (matters for closures)
4086     abort = abort || set_ref_in_functions(copyID);
4087 
4088     // function call arguments, if v:testing is set.
4089     abort = abort || set_ref_in_func_args(copyID);
4090 
4091     // v: vars
4092     abort = abort || garbage_collect_vimvars(copyID);
4093 
4094     // callbacks in buffers
4095     abort = abort || set_ref_in_buffers(copyID);
4096 
4097 #ifdef FEAT_LUA
4098     abort = abort || set_ref_in_lua(copyID);
4099 #endif
4100 
4101 #ifdef FEAT_PYTHON
4102     abort = abort || set_ref_in_python(copyID);
4103 #endif
4104 
4105 #ifdef FEAT_PYTHON3
4106     abort = abort || set_ref_in_python3(copyID);
4107 #endif
4108 
4109 #ifdef FEAT_JOB_CHANNEL
4110     abort = abort || set_ref_in_channel(copyID);
4111     abort = abort || set_ref_in_job(copyID);
4112 #endif
4113 #ifdef FEAT_NETBEANS_INTG
4114     abort = abort || set_ref_in_nb_channel(copyID);
4115 #endif
4116 
4117 #ifdef FEAT_TIMERS
4118     abort = abort || set_ref_in_timer(copyID);
4119 #endif
4120 
4121 #ifdef FEAT_QUICKFIX
4122     abort = abort || set_ref_in_quickfix(copyID);
4123 #endif
4124 
4125 #ifdef FEAT_TERMINAL
4126     abort = abort || set_ref_in_term(copyID);
4127 #endif
4128 
4129 #ifdef FEAT_PROP_POPUP
4130     abort = abort || set_ref_in_popups(copyID);
4131 #endif
4132 
4133     if (!abort)
4134     {
4135 	/*
4136 	 * 2. Free lists and dictionaries that are not referenced.
4137 	 */
4138 	did_free = free_unref_items(copyID);
4139 
4140 	/*
4141 	 * 3. Check if any funccal can be freed now.
4142 	 *    This may call us back recursively.
4143 	 */
4144 	free_unref_funccal(copyID, testing);
4145     }
4146     else if (p_verbose > 0)
4147     {
4148 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
4149     }
4150 
4151     return did_free;
4152 }
4153 
4154 /*
4155  * Free lists, dictionaries, channels and jobs that are no longer referenced.
4156  */
4157     static int
4158 free_unref_items(int copyID)
4159 {
4160     int		did_free = FALSE;
4161 
4162     // Let all "free" functions know that we are here.  This means no
4163     // dictionaries, lists, channels or jobs are to be freed, because we will
4164     // do that here.
4165     in_free_unref_items = TRUE;
4166 
4167     /*
4168      * PASS 1: free the contents of the items.  We don't free the items
4169      * themselves yet, so that it is possible to decrement refcount counters
4170      */
4171 
4172     // Go through the list of dicts and free items without the copyID.
4173     did_free |= dict_free_nonref(copyID);
4174 
4175     // Go through the list of lists and free items without the copyID.
4176     did_free |= list_free_nonref(copyID);
4177 
4178 #ifdef FEAT_JOB_CHANNEL
4179     // Go through the list of jobs and free items without the copyID. This
4180     // must happen before doing channels, because jobs refer to channels, but
4181     // the reference from the channel to the job isn't tracked.
4182     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4183 
4184     // Go through the list of channels and free items without the copyID.
4185     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4186 #endif
4187 
4188     /*
4189      * PASS 2: free the items themselves.
4190      */
4191     dict_free_items(copyID);
4192     list_free_items(copyID);
4193 
4194 #ifdef FEAT_JOB_CHANNEL
4195     // Go through the list of jobs and free items without the copyID. This
4196     // must happen before doing channels, because jobs refer to channels, but
4197     // the reference from the channel to the job isn't tracked.
4198     free_unused_jobs(copyID, COPYID_MASK);
4199 
4200     // Go through the list of channels and free items without the copyID.
4201     free_unused_channels(copyID, COPYID_MASK);
4202 #endif
4203 
4204     in_free_unref_items = FALSE;
4205 
4206     return did_free;
4207 }
4208 
4209 /*
4210  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4211  * "list_stack" is used to add lists to be marked.  Can be NULL.
4212  *
4213  * Returns TRUE if setting references failed somehow.
4214  */
4215     int
4216 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4217 {
4218     int		todo;
4219     int		abort = FALSE;
4220     hashitem_T	*hi;
4221     hashtab_T	*cur_ht;
4222     ht_stack_T	*ht_stack = NULL;
4223     ht_stack_T	*tempitem;
4224 
4225     cur_ht = ht;
4226     for (;;)
4227     {
4228 	if (!abort)
4229 	{
4230 	    // Mark each item in the hashtab.  If the item contains a hashtab
4231 	    // it is added to ht_stack, if it contains a list it is added to
4232 	    // list_stack.
4233 	    todo = (int)cur_ht->ht_used;
4234 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4235 		if (!HASHITEM_EMPTY(hi))
4236 		{
4237 		    --todo;
4238 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4239 						       &ht_stack, list_stack);
4240 		}
4241 	}
4242 
4243 	if (ht_stack == NULL)
4244 	    break;
4245 
4246 	// take an item from the stack
4247 	cur_ht = ht_stack->ht;
4248 	tempitem = ht_stack;
4249 	ht_stack = ht_stack->prev;
4250 	free(tempitem);
4251     }
4252 
4253     return abort;
4254 }
4255 
4256 /*
4257  * Mark a dict and its items with "copyID".
4258  * Returns TRUE if setting references failed somehow.
4259  */
4260     int
4261 set_ref_in_dict(dict_T *d, int copyID)
4262 {
4263     if (d != NULL && d->dv_copyID != copyID)
4264     {
4265 	d->dv_copyID = copyID;
4266 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4267     }
4268     return FALSE;
4269 }
4270 
4271 /*
4272  * Mark a list and its items with "copyID".
4273  * Returns TRUE if setting references failed somehow.
4274  */
4275     int
4276 set_ref_in_list(list_T *ll, int copyID)
4277 {
4278     if (ll != NULL && ll->lv_copyID != copyID)
4279     {
4280 	ll->lv_copyID = copyID;
4281 	return set_ref_in_list_items(ll, copyID, NULL);
4282     }
4283     return FALSE;
4284 }
4285 
4286 /*
4287  * Mark all lists and dicts referenced through list "l" with "copyID".
4288  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4289  *
4290  * Returns TRUE if setting references failed somehow.
4291  */
4292     int
4293 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4294 {
4295     listitem_T	 *li;
4296     int		 abort = FALSE;
4297     list_T	 *cur_l;
4298     list_stack_T *list_stack = NULL;
4299     list_stack_T *tempitem;
4300 
4301     cur_l = l;
4302     for (;;)
4303     {
4304 	if (!abort && cur_l->lv_first != &range_list_item)
4305 	    // Mark each item in the list.  If the item contains a hashtab
4306 	    // it is added to ht_stack, if it contains a list it is added to
4307 	    // list_stack.
4308 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4309 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4310 						       ht_stack, &list_stack);
4311 	if (list_stack == NULL)
4312 	    break;
4313 
4314 	// take an item from the stack
4315 	cur_l = list_stack->list;
4316 	tempitem = list_stack;
4317 	list_stack = list_stack->prev;
4318 	free(tempitem);
4319     }
4320 
4321     return abort;
4322 }
4323 
4324 /*
4325  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4326  * "list_stack" is used to add lists to be marked.  Can be NULL.
4327  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4328  *
4329  * Returns TRUE if setting references failed somehow.
4330  */
4331     int
4332 set_ref_in_item(
4333     typval_T	    *tv,
4334     int		    copyID,
4335     ht_stack_T	    **ht_stack,
4336     list_stack_T    **list_stack)
4337 {
4338     int		abort = FALSE;
4339 
4340     if (tv->v_type == VAR_DICT)
4341     {
4342 	dict_T	*dd = tv->vval.v_dict;
4343 
4344 	if (dd != NULL && dd->dv_copyID != copyID)
4345 	{
4346 	    // Didn't see this dict yet.
4347 	    dd->dv_copyID = copyID;
4348 	    if (ht_stack == NULL)
4349 	    {
4350 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4351 	    }
4352 	    else
4353 	    {
4354 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
4355 		if (newitem == NULL)
4356 		    abort = TRUE;
4357 		else
4358 		{
4359 		    newitem->ht = &dd->dv_hashtab;
4360 		    newitem->prev = *ht_stack;
4361 		    *ht_stack = newitem;
4362 		}
4363 	    }
4364 	}
4365     }
4366     else if (tv->v_type == VAR_LIST)
4367     {
4368 	list_T	*ll = tv->vval.v_list;
4369 
4370 	if (ll != NULL && ll->lv_copyID != copyID)
4371 	{
4372 	    // Didn't see this list yet.
4373 	    ll->lv_copyID = copyID;
4374 	    if (list_stack == NULL)
4375 	    {
4376 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4377 	    }
4378 	    else
4379 	    {
4380 		list_stack_T *newitem = (list_stack_T*)malloc(
4381 							sizeof(list_stack_T));
4382 		if (newitem == NULL)
4383 		    abort = TRUE;
4384 		else
4385 		{
4386 		    newitem->list = ll;
4387 		    newitem->prev = *list_stack;
4388 		    *list_stack = newitem;
4389 		}
4390 	    }
4391 	}
4392     }
4393     else if (tv->v_type == VAR_FUNC)
4394     {
4395 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4396     }
4397     else if (tv->v_type == VAR_PARTIAL)
4398     {
4399 	partial_T	*pt = tv->vval.v_partial;
4400 	int		i;
4401 
4402 	if (pt != NULL && pt->pt_copyID != copyID)
4403 	{
4404 	    // Didn't see this partial yet.
4405 	    pt->pt_copyID = copyID;
4406 
4407 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4408 
4409 	    if (pt->pt_dict != NULL)
4410 	    {
4411 		typval_T dtv;
4412 
4413 		dtv.v_type = VAR_DICT;
4414 		dtv.vval.v_dict = pt->pt_dict;
4415 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4416 	    }
4417 
4418 	    for (i = 0; i < pt->pt_argc; ++i)
4419 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4420 							ht_stack, list_stack);
4421 	    if (pt->pt_funcstack != NULL)
4422 	    {
4423 		typval_T    *stack = pt->pt_funcstack->fs_ga.ga_data;
4424 
4425 		for (i = 0; i < pt->pt_funcstack->fs_ga.ga_len; ++i)
4426 		    abort = abort || set_ref_in_item(stack + i, copyID,
4427 							 ht_stack, list_stack);
4428 	    }
4429 
4430 	}
4431     }
4432 #ifdef FEAT_JOB_CHANNEL
4433     else if (tv->v_type == VAR_JOB)
4434     {
4435 	job_T	    *job = tv->vval.v_job;
4436 	typval_T    dtv;
4437 
4438 	if (job != NULL && job->jv_copyID != copyID)
4439 	{
4440 	    job->jv_copyID = copyID;
4441 	    if (job->jv_channel != NULL)
4442 	    {
4443 		dtv.v_type = VAR_CHANNEL;
4444 		dtv.vval.v_channel = job->jv_channel;
4445 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4446 	    }
4447 	    if (job->jv_exit_cb.cb_partial != NULL)
4448 	    {
4449 		dtv.v_type = VAR_PARTIAL;
4450 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4451 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4452 	    }
4453 	}
4454     }
4455     else if (tv->v_type == VAR_CHANNEL)
4456     {
4457 	channel_T   *ch =tv->vval.v_channel;
4458 	ch_part_T   part;
4459 	typval_T    dtv;
4460 	jsonq_T	    *jq;
4461 	cbq_T	    *cq;
4462 
4463 	if (ch != NULL && ch->ch_copyID != copyID)
4464 	{
4465 	    ch->ch_copyID = copyID;
4466 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4467 	    {
4468 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4469 							     jq = jq->jq_next)
4470 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4471 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4472 							     cq = cq->cq_next)
4473 		    if (cq->cq_callback.cb_partial != NULL)
4474 		    {
4475 			dtv.v_type = VAR_PARTIAL;
4476 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4477 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4478 		    }
4479 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4480 		{
4481 		    dtv.v_type = VAR_PARTIAL;
4482 		    dtv.vval.v_partial =
4483 				      ch->ch_part[part].ch_callback.cb_partial;
4484 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4485 		}
4486 	    }
4487 	    if (ch->ch_callback.cb_partial != NULL)
4488 	    {
4489 		dtv.v_type = VAR_PARTIAL;
4490 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4491 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4492 	    }
4493 	    if (ch->ch_close_cb.cb_partial != NULL)
4494 	    {
4495 		dtv.v_type = VAR_PARTIAL;
4496 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4497 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4498 	    }
4499 	}
4500     }
4501 #endif
4502     return abort;
4503 }
4504 
4505 /*
4506  * Return a string with the string representation of a variable.
4507  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4508  * "numbuf" is used for a number.
4509  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4510  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4511  * stings as "string()", otherwise does not put quotes around strings, as
4512  * ":echo" displays values.
4513  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4514  * are replaced with "...".
4515  * May return NULL.
4516  */
4517     char_u *
4518 echo_string_core(
4519     typval_T	*tv,
4520     char_u	**tofree,
4521     char_u	*numbuf,
4522     int		copyID,
4523     int		echo_style,
4524     int		restore_copyID,
4525     int		composite_val)
4526 {
4527     static int	recurse = 0;
4528     char_u	*r = NULL;
4529 
4530     if (recurse >= DICT_MAXNEST)
4531     {
4532 	if (!did_echo_string_emsg)
4533 	{
4534 	    // Only give this message once for a recursive call to avoid
4535 	    // flooding the user with errors.  And stop iterating over lists
4536 	    // and dicts.
4537 	    did_echo_string_emsg = TRUE;
4538 	    emsg(_("E724: variable nested too deep for displaying"));
4539 	}
4540 	*tofree = NULL;
4541 	return (char_u *)"{E724}";
4542     }
4543     ++recurse;
4544 
4545     switch (tv->v_type)
4546     {
4547 	case VAR_STRING:
4548 	    if (echo_style && !composite_val)
4549 	    {
4550 		*tofree = NULL;
4551 		r = tv->vval.v_string;
4552 		if (r == NULL)
4553 		    r = (char_u *)"";
4554 	    }
4555 	    else
4556 	    {
4557 		*tofree = string_quote(tv->vval.v_string, FALSE);
4558 		r = *tofree;
4559 	    }
4560 	    break;
4561 
4562 	case VAR_FUNC:
4563 	    if (echo_style)
4564 	    {
4565 		*tofree = NULL;
4566 		r = tv->vval.v_string;
4567 	    }
4568 	    else
4569 	    {
4570 		*tofree = string_quote(tv->vval.v_string, TRUE);
4571 		r = *tofree;
4572 	    }
4573 	    break;
4574 
4575 	case VAR_PARTIAL:
4576 	    {
4577 		partial_T   *pt = tv->vval.v_partial;
4578 		char_u	    *fname = string_quote(pt == NULL ? NULL
4579 						    : partial_name(pt), FALSE);
4580 		garray_T    ga;
4581 		int	    i;
4582 		char_u	    *tf;
4583 
4584 		ga_init2(&ga, 1, 100);
4585 		ga_concat(&ga, (char_u *)"function(");
4586 		if (fname != NULL)
4587 		{
4588 		    ga_concat(&ga, fname);
4589 		    vim_free(fname);
4590 		}
4591 		if (pt != NULL && pt->pt_argc > 0)
4592 		{
4593 		    ga_concat(&ga, (char_u *)", [");
4594 		    for (i = 0; i < pt->pt_argc; ++i)
4595 		    {
4596 			if (i > 0)
4597 			    ga_concat(&ga, (char_u *)", ");
4598 			ga_concat(&ga,
4599 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
4600 			vim_free(tf);
4601 		    }
4602 		    ga_concat(&ga, (char_u *)"]");
4603 		}
4604 		if (pt != NULL && pt->pt_dict != NULL)
4605 		{
4606 		    typval_T dtv;
4607 
4608 		    ga_concat(&ga, (char_u *)", ");
4609 		    dtv.v_type = VAR_DICT;
4610 		    dtv.vval.v_dict = pt->pt_dict;
4611 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
4612 		    vim_free(tf);
4613 		}
4614 		ga_concat(&ga, (char_u *)")");
4615 
4616 		*tofree = ga.ga_data;
4617 		r = *tofree;
4618 		break;
4619 	    }
4620 
4621 	case VAR_BLOB:
4622 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
4623 	    break;
4624 
4625 	case VAR_LIST:
4626 	    if (tv->vval.v_list == NULL)
4627 	    {
4628 		// NULL list is equivalent to empty list.
4629 		*tofree = NULL;
4630 		r = (char_u *)"[]";
4631 	    }
4632 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
4633 		    && tv->vval.v_list->lv_len > 0)
4634 	    {
4635 		*tofree = NULL;
4636 		r = (char_u *)"[...]";
4637 	    }
4638 	    else
4639 	    {
4640 		int old_copyID = tv->vval.v_list->lv_copyID;
4641 
4642 		tv->vval.v_list->lv_copyID = copyID;
4643 		*tofree = list2string(tv, copyID, restore_copyID);
4644 		if (restore_copyID)
4645 		    tv->vval.v_list->lv_copyID = old_copyID;
4646 		r = *tofree;
4647 	    }
4648 	    break;
4649 
4650 	case VAR_DICT:
4651 	    if (tv->vval.v_dict == NULL)
4652 	    {
4653 		// NULL dict is equivalent to empty dict.
4654 		*tofree = NULL;
4655 		r = (char_u *)"{}";
4656 	    }
4657 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
4658 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
4659 	    {
4660 		*tofree = NULL;
4661 		r = (char_u *)"{...}";
4662 	    }
4663 	    else
4664 	    {
4665 		int old_copyID = tv->vval.v_dict->dv_copyID;
4666 
4667 		tv->vval.v_dict->dv_copyID = copyID;
4668 		*tofree = dict2string(tv, copyID, restore_copyID);
4669 		if (restore_copyID)
4670 		    tv->vval.v_dict->dv_copyID = old_copyID;
4671 		r = *tofree;
4672 	    }
4673 	    break;
4674 
4675 	case VAR_NUMBER:
4676 	case VAR_UNKNOWN:
4677 	case VAR_ANY:
4678 	case VAR_VOID:
4679 	    *tofree = NULL;
4680 	    r = tv_get_string_buf(tv, numbuf);
4681 	    break;
4682 
4683 	case VAR_JOB:
4684 	case VAR_CHANNEL:
4685 	    *tofree = NULL;
4686 	    r = tv_get_string_buf(tv, numbuf);
4687 	    if (composite_val)
4688 	    {
4689 		*tofree = string_quote(r, FALSE);
4690 		r = *tofree;
4691 	    }
4692 	    break;
4693 
4694 	case VAR_FLOAT:
4695 #ifdef FEAT_FLOAT
4696 	    *tofree = NULL;
4697 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
4698 	    r = numbuf;
4699 	    break;
4700 #endif
4701 
4702 	case VAR_BOOL:
4703 	case VAR_SPECIAL:
4704 	    *tofree = NULL;
4705 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
4706 	    break;
4707     }
4708 
4709     if (--recurse == 0)
4710 	did_echo_string_emsg = FALSE;
4711     return r;
4712 }
4713 
4714 /*
4715  * Return a string with the string representation of a variable.
4716  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4717  * "numbuf" is used for a number.
4718  * Does not put quotes around strings, as ":echo" displays values.
4719  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4720  * May return NULL.
4721  */
4722     char_u *
4723 echo_string(
4724     typval_T	*tv,
4725     char_u	**tofree,
4726     char_u	*numbuf,
4727     int		copyID)
4728 {
4729     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
4730 }
4731 
4732 /*
4733  * Return string "str" in ' quotes, doubling ' characters.
4734  * If "str" is NULL an empty string is assumed.
4735  * If "function" is TRUE make it function('string').
4736  */
4737     char_u *
4738 string_quote(char_u *str, int function)
4739 {
4740     unsigned	len;
4741     char_u	*p, *r, *s;
4742 
4743     len = (function ? 13 : 3);
4744     if (str != NULL)
4745     {
4746 	len += (unsigned)STRLEN(str);
4747 	for (p = str; *p != NUL; MB_PTR_ADV(p))
4748 	    if (*p == '\'')
4749 		++len;
4750     }
4751     s = r = alloc(len);
4752     if (r != NULL)
4753     {
4754 	if (function)
4755 	{
4756 	    STRCPY(r, "function('");
4757 	    r += 10;
4758 	}
4759 	else
4760 	    *r++ = '\'';
4761 	if (str != NULL)
4762 	    for (p = str; *p != NUL; )
4763 	    {
4764 		if (*p == '\'')
4765 		    *r++ = '\'';
4766 		MB_COPY_CHAR(p, r);
4767 	    }
4768 	*r++ = '\'';
4769 	if (function)
4770 	    *r++ = ')';
4771 	*r++ = NUL;
4772     }
4773     return s;
4774 }
4775 
4776 #if defined(FEAT_FLOAT) || defined(PROTO)
4777 /*
4778  * Convert the string "text" to a floating point number.
4779  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
4780  * this always uses a decimal point.
4781  * Returns the length of the text that was consumed.
4782  */
4783     int
4784 string2float(
4785     char_u	*text,
4786     float_T	*value)	    // result stored here
4787 {
4788     char	*s = (char *)text;
4789     float_T	f;
4790 
4791     // MS-Windows does not deal with "inf" and "nan" properly.
4792     if (STRNICMP(text, "inf", 3) == 0)
4793     {
4794 	*value = INFINITY;
4795 	return 3;
4796     }
4797     if (STRNICMP(text, "-inf", 3) == 0)
4798     {
4799 	*value = -INFINITY;
4800 	return 4;
4801     }
4802     if (STRNICMP(text, "nan", 3) == 0)
4803     {
4804 	*value = NAN;
4805 	return 3;
4806     }
4807     f = strtod(s, &s);
4808     *value = f;
4809     return (int)((char_u *)s - text);
4810 }
4811 #endif
4812 
4813 /*
4814  * Translate a String variable into a position.
4815  * Returns NULL when there is an error.
4816  */
4817     pos_T *
4818 var2fpos(
4819     typval_T	*varp,
4820     int		dollar_lnum,	// TRUE when $ is last line
4821     int		*fnum)		// set to fnum for '0, 'A, etc.
4822 {
4823     char_u		*name;
4824     static pos_T	pos;
4825     pos_T		*pp;
4826 
4827     // Argument can be [lnum, col, coladd].
4828     if (varp->v_type == VAR_LIST)
4829     {
4830 	list_T		*l;
4831 	int		len;
4832 	int		error = FALSE;
4833 	listitem_T	*li;
4834 
4835 	l = varp->vval.v_list;
4836 	if (l == NULL)
4837 	    return NULL;
4838 
4839 	// Get the line number
4840 	pos.lnum = list_find_nr(l, 0L, &error);
4841 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
4842 	    return NULL;	// invalid line number
4843 
4844 	// Get the column number
4845 	pos.col = list_find_nr(l, 1L, &error);
4846 	if (error)
4847 	    return NULL;
4848 	len = (long)STRLEN(ml_get(pos.lnum));
4849 
4850 	// We accept "$" for the column number: last column.
4851 	li = list_find(l, 1L);
4852 	if (li != NULL && li->li_tv.v_type == VAR_STRING
4853 		&& li->li_tv.vval.v_string != NULL
4854 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
4855 	    pos.col = len + 1;
4856 
4857 	// Accept a position up to the NUL after the line.
4858 	if (pos.col == 0 || (int)pos.col > len + 1)
4859 	    return NULL;	// invalid column number
4860 	--pos.col;
4861 
4862 	// Get the virtual offset.  Defaults to zero.
4863 	pos.coladd = list_find_nr(l, 2L, &error);
4864 	if (error)
4865 	    pos.coladd = 0;
4866 
4867 	return &pos;
4868     }
4869 
4870     name = tv_get_string_chk(varp);
4871     if (name == NULL)
4872 	return NULL;
4873     if (name[0] == '.')				// cursor
4874 	return &curwin->w_cursor;
4875     if (name[0] == 'v' && name[1] == NUL)	// Visual start
4876     {
4877 	if (VIsual_active)
4878 	    return &VIsual;
4879 	return &curwin->w_cursor;
4880     }
4881     if (name[0] == '\'')			// mark
4882     {
4883 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
4884 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
4885 	    return NULL;
4886 	return pp;
4887     }
4888 
4889     pos.coladd = 0;
4890 
4891     if (name[0] == 'w' && dollar_lnum)
4892     {
4893 	pos.col = 0;
4894 	if (name[1] == '0')		// "w0": first visible line
4895 	{
4896 	    update_topline();
4897 	    // In silent Ex mode topline is zero, but that's not a valid line
4898 	    // number; use one instead.
4899 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
4900 	    return &pos;
4901 	}
4902 	else if (name[1] == '$')	// "w$": last visible line
4903 	{
4904 	    validate_botline();
4905 	    // In silent Ex mode botline is zero, return zero then.
4906 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
4907 	    return &pos;
4908 	}
4909     }
4910     else if (name[0] == '$')		// last column or line
4911     {
4912 	if (dollar_lnum)
4913 	{
4914 	    pos.lnum = curbuf->b_ml.ml_line_count;
4915 	    pos.col = 0;
4916 	}
4917 	else
4918 	{
4919 	    pos.lnum = curwin->w_cursor.lnum;
4920 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
4921 	}
4922 	return &pos;
4923     }
4924     return NULL;
4925 }
4926 
4927 /*
4928  * Convert list in "arg" into a position and optional file number.
4929  * When "fnump" is NULL there is no file number, only 3 items.
4930  * Note that the column is passed on as-is, the caller may want to decrement
4931  * it to use 1 for the first column.
4932  * Return FAIL when conversion is not possible, doesn't check the position for
4933  * validity.
4934  */
4935     int
4936 list2fpos(
4937     typval_T	*arg,
4938     pos_T	*posp,
4939     int		*fnump,
4940     colnr_T	*curswantp)
4941 {
4942     list_T	*l = arg->vval.v_list;
4943     long	i = 0;
4944     long	n;
4945 
4946     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
4947     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
4948     if (arg->v_type != VAR_LIST
4949 	    || l == NULL
4950 	    || l->lv_len < (fnump == NULL ? 2 : 3)
4951 	    || l->lv_len > (fnump == NULL ? 4 : 5))
4952 	return FAIL;
4953 
4954     if (fnump != NULL)
4955     {
4956 	n = list_find_nr(l, i++, NULL);	// fnum
4957 	if (n < 0)
4958 	    return FAIL;
4959 	if (n == 0)
4960 	    n = curbuf->b_fnum;		// current buffer
4961 	*fnump = n;
4962     }
4963 
4964     n = list_find_nr(l, i++, NULL);	// lnum
4965     if (n < 0)
4966 	return FAIL;
4967     posp->lnum = n;
4968 
4969     n = list_find_nr(l, i++, NULL);	// col
4970     if (n < 0)
4971 	return FAIL;
4972     posp->col = n;
4973 
4974     n = list_find_nr(l, i, NULL);	// off
4975     if (n < 0)
4976 	posp->coladd = 0;
4977     else
4978 	posp->coladd = n;
4979 
4980     if (curswantp != NULL)
4981 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
4982 
4983     return OK;
4984 }
4985 
4986 /*
4987  * Get the length of an environment variable name.
4988  * Advance "arg" to the first character after the name.
4989  * Return 0 for error.
4990  */
4991     int
4992 get_env_len(char_u **arg)
4993 {
4994     char_u	*p;
4995     int		len;
4996 
4997     for (p = *arg; vim_isIDc(*p); ++p)
4998 	;
4999     if (p == *arg)	    // no name found
5000 	return 0;
5001 
5002     len = (int)(p - *arg);
5003     *arg = p;
5004     return len;
5005 }
5006 
5007 /*
5008  * Get the length of the name of a function or internal variable.
5009  * "arg" is advanced to after the name.
5010  * Return 0 if something is wrong.
5011  */
5012     int
5013 get_id_len(char_u **arg)
5014 {
5015     char_u	*p;
5016     int		len;
5017 
5018     // Find the end of the name.
5019     for (p = *arg; eval_isnamec(*p); ++p)
5020     {
5021 	if (*p == ':')
5022 	{
5023 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5024 	    // slice "[n:]".  Also "xx:" is not a namespace.
5025 	    len = (int)(p - *arg);
5026 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
5027 		    || len > 1)
5028 		break;
5029 	}
5030     }
5031     if (p == *arg)	    // no name found
5032 	return 0;
5033 
5034     len = (int)(p - *arg);
5035     *arg = p;
5036 
5037     return len;
5038 }
5039 
5040 /*
5041  * Get the length of the name of a variable or function.
5042  * Only the name is recognized, does not handle ".key" or "[idx]".
5043  * "arg" is advanced to the first non-white character after the name.
5044  * Return -1 if curly braces expansion failed.
5045  * Return 0 if something else is wrong.
5046  * If the name contains 'magic' {}'s, expand them and return the
5047  * expanded name in an allocated string via 'alias' - caller must free.
5048  */
5049     int
5050 get_name_len(
5051     char_u	**arg,
5052     char_u	**alias,
5053     int		evaluate,
5054     int		verbose)
5055 {
5056     int		len;
5057     char_u	*p;
5058     char_u	*expr_start;
5059     char_u	*expr_end;
5060 
5061     *alias = NULL;  // default to no alias
5062 
5063     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
5064 						  && (*arg)[2] == (int)KE_SNR)
5065     {
5066 	// hard coded <SNR>, already translated
5067 	*arg += 3;
5068 	return get_id_len(arg) + 3;
5069     }
5070     len = eval_fname_script(*arg);
5071     if (len > 0)
5072     {
5073 	// literal "<SID>", "s:" or "<SNR>"
5074 	*arg += len;
5075     }
5076 
5077     /*
5078      * Find the end of the name; check for {} construction.
5079      */
5080     p = find_name_end(*arg, &expr_start, &expr_end,
5081 					       len > 0 ? 0 : FNE_CHECK_START);
5082     if (expr_start != NULL)
5083     {
5084 	char_u	*temp_string;
5085 
5086 	if (!evaluate)
5087 	{
5088 	    len += (int)(p - *arg);
5089 	    *arg = skipwhite(p);
5090 	    return len;
5091 	}
5092 
5093 	/*
5094 	 * Include any <SID> etc in the expanded string:
5095 	 * Thus the -len here.
5096 	 */
5097 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
5098 	if (temp_string == NULL)
5099 	    return -1;
5100 	*alias = temp_string;
5101 	*arg = skipwhite(p);
5102 	return (int)STRLEN(temp_string);
5103     }
5104 
5105     len += get_id_len(arg);
5106     // Only give an error when there is something, otherwise it will be
5107     // reported at a higher level.
5108     if (len == 0 && verbose && **arg != NUL)
5109 	semsg(_(e_invexpr2), *arg);
5110 
5111     return len;
5112 }
5113 
5114 /*
5115  * Find the end of a variable or function name, taking care of magic braces.
5116  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
5117  * start and end of the first magic braces item.
5118  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
5119  * Return a pointer to just after the name.  Equal to "arg" if there is no
5120  * valid name.
5121  */
5122     char_u *
5123 find_name_end(
5124     char_u	*arg,
5125     char_u	**expr_start,
5126     char_u	**expr_end,
5127     int		flags)
5128 {
5129     int		mb_nest = 0;
5130     int		br_nest = 0;
5131     char_u	*p;
5132     int		len;
5133     int		vim9script = in_vim9script();
5134 
5135     if (expr_start != NULL)
5136     {
5137 	*expr_start = NULL;
5138 	*expr_end = NULL;
5139     }
5140 
5141     // Quick check for valid starting character.
5142     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg)
5143 						&& (*arg != '{' || vim9script))
5144 	return arg;
5145 
5146     for (p = arg; *p != NUL
5147 		    && (eval_isnamec(*p)
5148 			|| (*p == '{' && !vim9script)
5149 			|| ((flags & FNE_INCL_BR) && (*p == '['
5150 					 || (*p == '.' && eval_isdictc(p[1]))))
5151 			|| mb_nest != 0
5152 			|| br_nest != 0); MB_PTR_ADV(p))
5153     {
5154 	if (*p == '\'')
5155 	{
5156 	    // skip over 'string' to avoid counting [ and ] inside it.
5157 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5158 		;
5159 	    if (*p == NUL)
5160 		break;
5161 	}
5162 	else if (*p == '"')
5163 	{
5164 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
5165 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5166 		if (*p == '\\' && p[1] != NUL)
5167 		    ++p;
5168 	    if (*p == NUL)
5169 		break;
5170 	}
5171 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5172 	{
5173 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5174 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
5175 	    len = (int)(p - arg);
5176 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5177 		    || (len > 1 && p[-1] != '}'))
5178 		break;
5179 	}
5180 
5181 	if (mb_nest == 0)
5182 	{
5183 	    if (*p == '[')
5184 		++br_nest;
5185 	    else if (*p == ']')
5186 		--br_nest;
5187 	}
5188 
5189 	if (br_nest == 0 && !vim9script)
5190 	{
5191 	    if (*p == '{')
5192 	    {
5193 		mb_nest++;
5194 		if (expr_start != NULL && *expr_start == NULL)
5195 		    *expr_start = p;
5196 	    }
5197 	    else if (*p == '}')
5198 	    {
5199 		mb_nest--;
5200 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5201 		    *expr_end = p;
5202 	    }
5203 	}
5204     }
5205 
5206     return p;
5207 }
5208 
5209 /*
5210  * Expands out the 'magic' {}'s in a variable/function name.
5211  * Note that this can call itself recursively, to deal with
5212  * constructs like foo{bar}{baz}{bam}
5213  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5214  *			"in_start"      ^
5215  *			"expr_start"	   ^
5216  *			"expr_end"		 ^
5217  *			"in_end"			    ^
5218  *
5219  * Returns a new allocated string, which the caller must free.
5220  * Returns NULL for failure.
5221  */
5222     static char_u *
5223 make_expanded_name(
5224     char_u	*in_start,
5225     char_u	*expr_start,
5226     char_u	*expr_end,
5227     char_u	*in_end)
5228 {
5229     char_u	c1;
5230     char_u	*retval = NULL;
5231     char_u	*temp_result;
5232 
5233     if (expr_end == NULL || in_end == NULL)
5234 	return NULL;
5235     *expr_start	= NUL;
5236     *expr_end = NUL;
5237     c1 = *in_end;
5238     *in_end = NUL;
5239 
5240     temp_result = eval_to_string(expr_start + 1, FALSE);
5241     if (temp_result != NULL)
5242     {
5243 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5244 						   + (in_end - expr_end) + 1);
5245 	if (retval != NULL)
5246 	{
5247 	    STRCPY(retval, in_start);
5248 	    STRCAT(retval, temp_result);
5249 	    STRCAT(retval, expr_end + 1);
5250 	}
5251     }
5252     vim_free(temp_result);
5253 
5254     *in_end = c1;		// put char back for error messages
5255     *expr_start = '{';
5256     *expr_end = '}';
5257 
5258     if (retval != NULL)
5259     {
5260 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5261 	if (expr_start != NULL)
5262 	{
5263 	    // Further expansion!
5264 	    temp_result = make_expanded_name(retval, expr_start,
5265 						       expr_end, temp_result);
5266 	    vim_free(retval);
5267 	    retval = temp_result;
5268 	}
5269     }
5270 
5271     return retval;
5272 }
5273 
5274 /*
5275  * Return TRUE if character "c" can be used in a variable or function name.
5276  * Does not include '{' or '}' for magic braces.
5277  */
5278     int
5279 eval_isnamec(int c)
5280 {
5281     return ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR;
5282 }
5283 
5284 /*
5285  * Return TRUE if character "c" can be used as the first character in a
5286  * variable or function name (excluding '{' and '}').
5287  */
5288     int
5289 eval_isnamec1(int c)
5290 {
5291     return ASCII_ISALPHA(c) || c == '_';
5292 }
5293 
5294 /*
5295  * Return TRUE if character "c" can be used as the first character of a
5296  * dictionary key.
5297  */
5298     int
5299 eval_isdictc(int c)
5300 {
5301     return ASCII_ISALNUM(c) || c == '_';
5302 }
5303 
5304 /*
5305  * Return the character "str[index]" where "index" is the character index.  If
5306  * "index" is out of range NULL is returned.
5307  */
5308     char_u *
5309 char_from_string(char_u *str, varnumber_T index)
5310 {
5311     size_t	    nbyte = 0;
5312     varnumber_T	    nchar = index;
5313     size_t	    slen;
5314 
5315     if (str == NULL || index < 0)
5316 	return NULL;
5317     slen = STRLEN(str);
5318     while (nchar > 0 && nbyte < slen)
5319     {
5320 	nbyte += MB_CPTR2LEN(str + nbyte);
5321 	--nchar;
5322     }
5323     if (nbyte >= slen)
5324 	return NULL;
5325     return vim_strnsave(str + nbyte, MB_CPTR2LEN(str + nbyte));
5326 }
5327 
5328 /*
5329  * Get the byte index for character index "idx" in string "str" with length
5330  * "str_len".
5331  * If going over the end return "str_len".
5332  * If "idx" is negative count from the end, -1 is the last character.
5333  * When going over the start return -1.
5334  */
5335     static long
5336 char_idx2byte(char_u *str, size_t str_len, varnumber_T idx)
5337 {
5338     varnumber_T nchar = idx;
5339     size_t	nbyte = 0;
5340 
5341     if (nchar >= 0)
5342     {
5343 	while (nchar > 0 && nbyte < str_len)
5344 	{
5345 	    nbyte += MB_CPTR2LEN(str + nbyte);
5346 	    --nchar;
5347 	}
5348     }
5349     else
5350     {
5351 	nbyte = str_len;
5352 	while (nchar < 0 && nbyte > 0)
5353 	{
5354 	    --nbyte;
5355 	    nbyte -= mb_head_off(str, str + nbyte);
5356 	    ++nchar;
5357 	}
5358 	if (nchar < 0)
5359 	    return -1;
5360     }
5361     return (long)nbyte;
5362 }
5363 
5364 /*
5365  * Return the slice "str[first:last]" using character indexes.
5366  * Return NULL when the result is empty.
5367  */
5368     char_u *
5369 string_slice(char_u *str, varnumber_T first, varnumber_T last)
5370 {
5371     long	start_byte, end_byte;
5372     size_t	slen;
5373 
5374     if (str == NULL)
5375 	return NULL;
5376     slen = STRLEN(str);
5377     start_byte = char_idx2byte(str, slen, first);
5378     if (start_byte < 0)
5379 	start_byte = 0; // first index very negative: use zero
5380     if (last == -1)
5381 	end_byte = slen;
5382     else
5383     {
5384 	end_byte = char_idx2byte(str, slen, last);
5385 	if (end_byte >= 0 && end_byte < (long)slen)
5386 	    // end index is inclusive
5387 	    end_byte += MB_CPTR2LEN(str + end_byte);
5388     }
5389 
5390     if (start_byte >= (long)slen || end_byte <= start_byte)
5391 	return NULL;
5392     return vim_strnsave(str + start_byte, end_byte - start_byte);
5393 }
5394 
5395 /*
5396  * Handle:
5397  * - expr[expr], expr[expr:expr] subscript
5398  * - ".name" lookup
5399  * - function call with Funcref variable: func(expr)
5400  * - method call: var->method()
5401  *
5402  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5403  */
5404     int
5405 handle_subscript(
5406     char_u	**arg,
5407     typval_T	*rettv,
5408     evalarg_T	*evalarg,
5409     int		verbose)	// give error messages
5410 {
5411     int		evaluate = evalarg != NULL
5412 				      && (evalarg->eval_flags & EVAL_EVALUATE);
5413     int		ret = OK;
5414     dict_T	*selfdict = NULL;
5415     int		check_white = TRUE;
5416     int		getnext;
5417     char_u	*p;
5418 
5419     while (ret == OK)
5420     {
5421 	// When at the end of the line and ".name" or "->{" or "->X" follows in
5422 	// the next line then consume the line break.
5423 	p = eval_next_non_blank(*arg, evalarg, &getnext);
5424 	if (getnext
5425 	    && ((rettv->v_type == VAR_DICT && *p == '.' && eval_isdictc(p[1]))
5426 		|| (p[0] == '-' && p[1] == '>'
5427 				     && (p[2] == '{' || ASCII_ISALPHA(p[2])))))
5428 	{
5429 	    *arg = eval_next_line(evalarg);
5430 	    p = *arg;
5431 	    check_white = FALSE;
5432 	}
5433 
5434 	if ((**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5435 			    || rettv->v_type == VAR_PARTIAL))
5436 		    && (!check_white || !VIM_ISWHITE(*(*arg - 1))))
5437 	{
5438 	    ret = call_func_rettv(arg, evalarg, rettv, evaluate,
5439 							       selfdict, NULL);
5440 
5441 	    // Stop the expression evaluation when immediately aborting on
5442 	    // error, or when an interrupt occurred or an exception was thrown
5443 	    // but not caught.
5444 	    if (aborting())
5445 	    {
5446 		if (ret == OK)
5447 		    clear_tv(rettv);
5448 		ret = FAIL;
5449 	    }
5450 	    dict_unref(selfdict);
5451 	    selfdict = NULL;
5452 	}
5453 	else if (p[0] == '-' && p[1] == '>')
5454 	{
5455 	    *arg = p;
5456 	    if (ret == OK)
5457 	    {
5458 		if ((*arg)[2] == '{')
5459 		    // expr->{lambda}()
5460 		    ret = eval_lambda(arg, rettv, evalarg, verbose);
5461 		else
5462 		    // expr->name()
5463 		    ret = eval_method(arg, rettv, evalarg, verbose);
5464 	    }
5465 	}
5466 	// "." is ".name" lookup when we found a dict or when evaluating and
5467 	// scriptversion is at least 2, where string concatenation is "..".
5468 	else if (**arg == '['
5469 		|| (**arg == '.' && (rettv->v_type == VAR_DICT
5470 			|| (!evaluate
5471 			    && (*arg)[1] != '.'
5472 			    && current_sctx.sc_version >= 2))))
5473 	{
5474 	    dict_unref(selfdict);
5475 	    if (rettv->v_type == VAR_DICT)
5476 	    {
5477 		selfdict = rettv->vval.v_dict;
5478 		if (selfdict != NULL)
5479 		    ++selfdict->dv_refcount;
5480 	    }
5481 	    else
5482 		selfdict = NULL;
5483 	    if (eval_index(arg, rettv, evalarg, verbose) == FAIL)
5484 	    {
5485 		clear_tv(rettv);
5486 		ret = FAIL;
5487 	    }
5488 	}
5489 	else
5490 	    break;
5491     }
5492 
5493     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5494     // Don't do this when "Func" is already a partial that was bound
5495     // explicitly (pt_auto is FALSE).
5496     if (selfdict != NULL
5497 	    && (rettv->v_type == VAR_FUNC
5498 		|| (rettv->v_type == VAR_PARTIAL
5499 		    && (rettv->vval.v_partial->pt_auto
5500 			|| rettv->vval.v_partial->pt_dict == NULL))))
5501 	selfdict = make_partial(selfdict, rettv);
5502 
5503     dict_unref(selfdict);
5504     return ret;
5505 }
5506 
5507 /*
5508  * Make a copy of an item.
5509  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5510  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5511  * reference to an already copied list/dict can be used.
5512  * Returns FAIL or OK.
5513  */
5514     int
5515 item_copy(
5516     typval_T	*from,
5517     typval_T	*to,
5518     int		deep,
5519     int		copyID)
5520 {
5521     static int	recurse = 0;
5522     int		ret = OK;
5523 
5524     if (recurse >= DICT_MAXNEST)
5525     {
5526 	emsg(_("E698: variable nested too deep for making a copy"));
5527 	return FAIL;
5528     }
5529     ++recurse;
5530 
5531     switch (from->v_type)
5532     {
5533 	case VAR_NUMBER:
5534 	case VAR_FLOAT:
5535 	case VAR_STRING:
5536 	case VAR_FUNC:
5537 	case VAR_PARTIAL:
5538 	case VAR_BOOL:
5539 	case VAR_SPECIAL:
5540 	case VAR_JOB:
5541 	case VAR_CHANNEL:
5542 	    copy_tv(from, to);
5543 	    break;
5544 	case VAR_LIST:
5545 	    to->v_type = VAR_LIST;
5546 	    to->v_lock = 0;
5547 	    if (from->vval.v_list == NULL)
5548 		to->vval.v_list = NULL;
5549 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
5550 	    {
5551 		// use the copy made earlier
5552 		to->vval.v_list = from->vval.v_list->lv_copylist;
5553 		++to->vval.v_list->lv_refcount;
5554 	    }
5555 	    else
5556 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
5557 	    if (to->vval.v_list == NULL)
5558 		ret = FAIL;
5559 	    break;
5560 	case VAR_BLOB:
5561 	    ret = blob_copy(from->vval.v_blob, to);
5562 	    break;
5563 	case VAR_DICT:
5564 	    to->v_type = VAR_DICT;
5565 	    to->v_lock = 0;
5566 	    if (from->vval.v_dict == NULL)
5567 		to->vval.v_dict = NULL;
5568 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
5569 	    {
5570 		// use the copy made earlier
5571 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
5572 		++to->vval.v_dict->dv_refcount;
5573 	    }
5574 	    else
5575 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
5576 	    if (to->vval.v_dict == NULL)
5577 		ret = FAIL;
5578 	    break;
5579 	case VAR_UNKNOWN:
5580 	case VAR_ANY:
5581 	case VAR_VOID:
5582 	    internal_error_no_abort("item_copy(UNKNOWN)");
5583 	    ret = FAIL;
5584     }
5585     --recurse;
5586     return ret;
5587 }
5588 
5589     void
5590 echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr)
5591 {
5592     char_u	*tofree;
5593     char_u	numbuf[NUMBUFLEN];
5594     char_u	*p = echo_string(rettv, &tofree, numbuf, get_copyID());
5595 
5596     if (*atstart)
5597     {
5598 	*atstart = FALSE;
5599 	// Call msg_start() after eval1(), evaluating the expression
5600 	// may cause a message to appear.
5601 	if (with_space)
5602 	{
5603 	    // Mark the saved text as finishing the line, so that what
5604 	    // follows is displayed on a new line when scrolling back
5605 	    // at the more prompt.
5606 	    msg_sb_eol();
5607 	    msg_start();
5608 	}
5609     }
5610     else if (with_space)
5611 	msg_puts_attr(" ", echo_attr);
5612 
5613     if (p != NULL)
5614 	for ( ; *p != NUL && !got_int; ++p)
5615 	{
5616 	    if (*p == '\n' || *p == '\r' || *p == TAB)
5617 	    {
5618 		if (*p != TAB && *needclr)
5619 		{
5620 		    // remove any text still there from the command
5621 		    msg_clr_eos();
5622 		    *needclr = FALSE;
5623 		}
5624 		msg_putchar_attr(*p, echo_attr);
5625 	    }
5626 	    else
5627 	    {
5628 		if (has_mbyte)
5629 		{
5630 		    int i = (*mb_ptr2len)(p);
5631 
5632 		    (void)msg_outtrans_len_attr(p, i, echo_attr);
5633 		    p += i - 1;
5634 		}
5635 		else
5636 		    (void)msg_outtrans_len_attr(p, 1, echo_attr);
5637 	    }
5638 	}
5639     vim_free(tofree);
5640 }
5641 
5642 /*
5643  * ":echo expr1 ..."	print each argument separated with a space, add a
5644  *			newline at the end.
5645  * ":echon expr1 ..."	print each argument plain.
5646  */
5647     void
5648 ex_echo(exarg_T *eap)
5649 {
5650     char_u	*arg = eap->arg;
5651     typval_T	rettv;
5652     char_u	*p;
5653     int		needclr = TRUE;
5654     int		atstart = TRUE;
5655     int		did_emsg_before = did_emsg;
5656     int		called_emsg_before = called_emsg;
5657     evalarg_T	evalarg;
5658 
5659     fill_evalarg_from_eap(&evalarg, eap, eap->skip);
5660 
5661     if (eap->skip)
5662 	++emsg_skip;
5663     while ((!ends_excmd2(eap->cmd, arg) || *arg == '"') && !got_int)
5664     {
5665 	// If eval1() causes an error message the text from the command may
5666 	// still need to be cleared. E.g., "echo 22,44".
5667 	need_clr_eos = needclr;
5668 
5669 	p = arg;
5670 	if (eval1(&arg, &rettv, &evalarg) == FAIL)
5671 	{
5672 	    /*
5673 	     * Report the invalid expression unless the expression evaluation
5674 	     * has been cancelled due to an aborting error, an interrupt, or an
5675 	     * exception.
5676 	     */
5677 	    if (!aborting() && did_emsg == did_emsg_before
5678 					  && called_emsg == called_emsg_before)
5679 		semsg(_(e_invexpr2), p);
5680 	    need_clr_eos = FALSE;
5681 	    break;
5682 	}
5683 	need_clr_eos = FALSE;
5684 
5685 	if (!eap->skip)
5686 	    echo_one(&rettv, eap->cmdidx == CMD_echo, &atstart, &needclr);
5687 
5688 	clear_tv(&rettv);
5689 	arg = skipwhite(arg);
5690     }
5691     eap->nextcmd = check_nextcmd(arg);
5692     clear_evalarg(&evalarg, eap);
5693 
5694     if (eap->skip)
5695 	--emsg_skip;
5696     else
5697     {
5698 	// remove text that may still be there from the command
5699 	if (needclr)
5700 	    msg_clr_eos();
5701 	if (eap->cmdidx == CMD_echo)
5702 	    msg_end();
5703     }
5704 }
5705 
5706 /*
5707  * ":echohl {name}".
5708  */
5709     void
5710 ex_echohl(exarg_T *eap)
5711 {
5712     echo_attr = syn_name2attr(eap->arg);
5713 }
5714 
5715 /*
5716  * Returns the :echo attribute
5717  */
5718     int
5719 get_echo_attr(void)
5720 {
5721     return echo_attr;
5722 }
5723 
5724 /*
5725  * ":execute expr1 ..."	execute the result of an expression.
5726  * ":echomsg expr1 ..."	Print a message
5727  * ":echoerr expr1 ..."	Print an error
5728  * Each gets spaces around each argument and a newline at the end for
5729  * echo commands
5730  */
5731     void
5732 ex_execute(exarg_T *eap)
5733 {
5734     char_u	*arg = eap->arg;
5735     typval_T	rettv;
5736     int		ret = OK;
5737     char_u	*p;
5738     garray_T	ga;
5739     int		len;
5740 
5741     ga_init2(&ga, 1, 80);
5742 
5743     if (eap->skip)
5744 	++emsg_skip;
5745     while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
5746     {
5747 	ret = eval1_emsg(&arg, &rettv, eap);
5748 	if (ret == FAIL)
5749 	    break;
5750 
5751 	if (!eap->skip)
5752 	{
5753 	    char_u   buf[NUMBUFLEN];
5754 
5755 	    if (eap->cmdidx == CMD_execute)
5756 	    {
5757 		if (rettv.v_type == VAR_CHANNEL || rettv.v_type == VAR_JOB)
5758 		{
5759 		    emsg(_(e_inval_string));
5760 		    p = NULL;
5761 		}
5762 		else
5763 		    p = tv_get_string_buf(&rettv, buf);
5764 	    }
5765 	    else
5766 		p = tv_stringify(&rettv, buf);
5767 	    if (p == NULL)
5768 	    {
5769 		clear_tv(&rettv);
5770 		ret = FAIL;
5771 		break;
5772 	    }
5773 	    len = (int)STRLEN(p);
5774 	    if (ga_grow(&ga, len + 2) == FAIL)
5775 	    {
5776 		clear_tv(&rettv);
5777 		ret = FAIL;
5778 		break;
5779 	    }
5780 	    if (ga.ga_len)
5781 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
5782 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
5783 	    ga.ga_len += len;
5784 	}
5785 
5786 	clear_tv(&rettv);
5787 	arg = skipwhite(arg);
5788     }
5789 
5790     if (ret != FAIL && ga.ga_data != NULL)
5791     {
5792 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
5793 	{
5794 	    // Mark the already saved text as finishing the line, so that what
5795 	    // follows is displayed on a new line when scrolling back at the
5796 	    // more prompt.
5797 	    msg_sb_eol();
5798 	}
5799 
5800 	if (eap->cmdidx == CMD_echomsg)
5801 	{
5802 	    msg_attr(ga.ga_data, echo_attr);
5803 	    out_flush();
5804 	}
5805 	else if (eap->cmdidx == CMD_echoerr)
5806 	{
5807 	    int		save_did_emsg = did_emsg;
5808 
5809 	    // We don't want to abort following commands, restore did_emsg.
5810 	    emsg(ga.ga_data);
5811 	    if (!force_abort)
5812 		did_emsg = save_did_emsg;
5813 	}
5814 	else if (eap->cmdidx == CMD_execute)
5815 	    do_cmdline((char_u *)ga.ga_data,
5816 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
5817     }
5818 
5819     ga_clear(&ga);
5820 
5821     if (eap->skip)
5822 	--emsg_skip;
5823 
5824     eap->nextcmd = check_nextcmd(arg);
5825 }
5826 
5827 /*
5828  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
5829  * "arg" points to the "&" or '+' when called, to "option" when returning.
5830  * Returns NULL when no option name found.  Otherwise pointer to the char
5831  * after the option name.
5832  */
5833     char_u *
5834 find_option_end(char_u **arg, int *opt_flags)
5835 {
5836     char_u	*p = *arg;
5837 
5838     ++p;
5839     if (*p == 'g' && p[1] == ':')
5840     {
5841 	*opt_flags = OPT_GLOBAL;
5842 	p += 2;
5843     }
5844     else if (*p == 'l' && p[1] == ':')
5845     {
5846 	*opt_flags = OPT_LOCAL;
5847 	p += 2;
5848     }
5849     else
5850 	*opt_flags = 0;
5851 
5852     if (!ASCII_ISALPHA(*p))
5853 	return NULL;
5854     *arg = p;
5855 
5856     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
5857 	p += 4;	    // termcap option
5858     else
5859 	while (ASCII_ISALPHA(*p))
5860 	    ++p;
5861     return p;
5862 }
5863 
5864 /*
5865  * Display script name where an item was last set.
5866  * Should only be invoked when 'verbose' is non-zero.
5867  */
5868     void
5869 last_set_msg(sctx_T script_ctx)
5870 {
5871     char_u *p;
5872 
5873     if (script_ctx.sc_sid != 0)
5874     {
5875 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
5876 	if (p != NULL)
5877 	{
5878 	    verbose_enter();
5879 	    msg_puts(_("\n\tLast set from "));
5880 	    msg_puts((char *)p);
5881 	    if (script_ctx.sc_lnum > 0)
5882 	    {
5883 		msg_puts(_(line_msg));
5884 		msg_outnum((long)script_ctx.sc_lnum);
5885 	    }
5886 	    verbose_leave();
5887 	    vim_free(p);
5888 	}
5889     }
5890 }
5891 
5892 #endif // FEAT_EVAL
5893 
5894 /*
5895  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
5896  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
5897  * "flags" can be "g" to do a global substitute.
5898  * Returns an allocated string, NULL for error.
5899  */
5900     char_u *
5901 do_string_sub(
5902     char_u	*str,
5903     char_u	*pat,
5904     char_u	*sub,
5905     typval_T	*expr,
5906     char_u	*flags)
5907 {
5908     int		sublen;
5909     regmatch_T	regmatch;
5910     int		i;
5911     int		do_all;
5912     char_u	*tail;
5913     char_u	*end;
5914     garray_T	ga;
5915     char_u	*ret;
5916     char_u	*save_cpo;
5917     char_u	*zero_width = NULL;
5918 
5919     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
5920     save_cpo = p_cpo;
5921     p_cpo = empty_option;
5922 
5923     ga_init2(&ga, 1, 200);
5924 
5925     do_all = (flags[0] == 'g');
5926 
5927     regmatch.rm_ic = p_ic;
5928     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
5929     if (regmatch.regprog != NULL)
5930     {
5931 	tail = str;
5932 	end = str + STRLEN(str);
5933 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
5934 	{
5935 	    // Skip empty match except for first match.
5936 	    if (regmatch.startp[0] == regmatch.endp[0])
5937 	    {
5938 		if (zero_width == regmatch.startp[0])
5939 		{
5940 		    // avoid getting stuck on a match with an empty string
5941 		    i = mb_ptr2len(tail);
5942 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
5943 								   (size_t)i);
5944 		    ga.ga_len += i;
5945 		    tail += i;
5946 		    continue;
5947 		}
5948 		zero_width = regmatch.startp[0];
5949 	    }
5950 
5951 	    /*
5952 	     * Get some space for a temporary buffer to do the substitution
5953 	     * into.  It will contain:
5954 	     * - The text up to where the match is.
5955 	     * - The substituted text.
5956 	     * - The text after the match.
5957 	     */
5958 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
5959 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
5960 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
5961 	    {
5962 		ga_clear(&ga);
5963 		break;
5964 	    }
5965 
5966 	    // copy the text up to where the match is
5967 	    i = (int)(regmatch.startp[0] - tail);
5968 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
5969 	    // add the substituted text
5970 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
5971 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
5972 	    ga.ga_len += i + sublen - 1;
5973 	    tail = regmatch.endp[0];
5974 	    if (*tail == NUL)
5975 		break;
5976 	    if (!do_all)
5977 		break;
5978 	}
5979 
5980 	if (ga.ga_data != NULL)
5981 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
5982 
5983 	vim_regfree(regmatch.regprog);
5984     }
5985 
5986     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
5987     ga_clear(&ga);
5988     if (p_cpo == empty_option)
5989 	p_cpo = save_cpo;
5990     else
5991 	// Darn, evaluating {sub} expression or {expr} changed the value.
5992 	free_string_option(save_cpo);
5993 
5994     return ret;
5995 }
5996