xref: /vim-8.2.3635/src/eval.c (revision 23515b4e)
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 = tv_get_bool_chk(&tv, error);
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, evalarg_T *evalarg)
372 {
373     typval_T	rettv;
374 
375     *pp = skipwhite(*pp);
376     return eval1(pp, &rettv, evalarg);
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 == NULL ? NULL : &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_eap(
478     char_u	*arg,
479     int		convert,
480     exarg_T	*eap)
481 {
482     typval_T	tv;
483     char_u	*retval;
484     garray_T	ga;
485 #ifdef FEAT_FLOAT
486     char_u	numbuf[NUMBUFLEN];
487 #endif
488     evalarg_T	evalarg;
489 
490     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
491     if (eval0(arg, &tv, NULL, &evalarg) == FAIL)
492 	retval = NULL;
493     else
494     {
495 	if (convert && tv.v_type == VAR_LIST)
496 	{
497 	    ga_init2(&ga, (int)sizeof(char), 80);
498 	    if (tv.vval.v_list != NULL)
499 	    {
500 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
501 		if (tv.vval.v_list->lv_len > 0)
502 		    ga_append(&ga, NL);
503 	    }
504 	    ga_append(&ga, NUL);
505 	    retval = (char_u *)ga.ga_data;
506 	}
507 #ifdef FEAT_FLOAT
508 	else if (convert && tv.v_type == VAR_FLOAT)
509 	{
510 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
511 	    retval = vim_strsave(numbuf);
512 	}
513 #endif
514 	else
515 	    retval = vim_strsave(tv_get_string(&tv));
516 	clear_tv(&tv);
517     }
518     clear_evalarg(&evalarg, NULL);
519 
520     return retval;
521 }
522 
523     char_u *
524 eval_to_string(
525     char_u	*arg,
526     int		convert)
527 {
528     return eval_to_string_eap(arg, convert, NULL);
529 }
530 
531 /*
532  * Call eval_to_string() without using current local variables and using
533  * textwinlock.  When "use_sandbox" is TRUE use the sandbox.
534  * Use legacy Vim script syntax.
535  */
536     char_u *
537 eval_to_string_safe(
538     char_u	*arg,
539     int		use_sandbox)
540 {
541     char_u	*retval;
542     funccal_entry_T funccal_entry;
543     int		save_sc_version = current_sctx.sc_version;
544 
545     current_sctx.sc_version = 1;
546     save_funccal(&funccal_entry);
547     if (use_sandbox)
548 	++sandbox;
549     ++textwinlock;
550     retval = eval_to_string(arg, FALSE);
551     if (use_sandbox)
552 	--sandbox;
553     --textwinlock;
554     restore_funccal();
555     current_sctx.sc_version = save_sc_version;
556     return retval;
557 }
558 
559 /*
560  * Top level evaluation function, returning a number.
561  * Evaluates "expr" silently.
562  * Returns -1 for an error.
563  */
564     varnumber_T
565 eval_to_number(char_u *expr)
566 {
567     typval_T	rettv;
568     varnumber_T	retval;
569     char_u	*p = skipwhite(expr);
570 
571     ++emsg_off;
572 
573     if (eval1(&p, &rettv, &EVALARG_EVALUATE) == FAIL)
574 	retval = -1;
575     else
576     {
577 	retval = tv_get_number_chk(&rettv, NULL);
578 	clear_tv(&rettv);
579     }
580     --emsg_off;
581 
582     return retval;
583 }
584 
585 /*
586  * Top level evaluation function.
587  * Returns an allocated typval_T with the result.
588  * Returns NULL when there is an error.
589  */
590     typval_T *
591 eval_expr(char_u *arg, exarg_T *eap)
592 {
593     typval_T	*tv;
594     evalarg_T	evalarg;
595 
596     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
597 
598     tv = ALLOC_ONE(typval_T);
599     if (tv != NULL && eval0(arg, tv, eap, &evalarg) == FAIL)
600 	VIM_CLEAR(tv);
601 
602     clear_evalarg(&evalarg, eap);
603     return tv;
604 }
605 
606 /*
607  * Call some Vim script function and return the result in "*rettv".
608  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
609  * should have type VAR_UNKNOWN.
610  * Returns OK or FAIL.
611  */
612     int
613 call_vim_function(
614     char_u      *func,
615     int		argc,
616     typval_T	*argv,
617     typval_T	*rettv)
618 {
619     int		ret;
620     funcexe_T	funcexe;
621 
622     rettv->v_type = VAR_UNKNOWN;		// clear_tv() uses this
623     CLEAR_FIELD(funcexe);
624     funcexe.firstline = curwin->w_cursor.lnum;
625     funcexe.lastline = curwin->w_cursor.lnum;
626     funcexe.evaluate = TRUE;
627     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
628     if (ret == FAIL)
629 	clear_tv(rettv);
630 
631     return ret;
632 }
633 
634 /*
635  * Call Vim script function "func" and return the result as a number.
636  * Returns -1 when calling the function fails.
637  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
638  * have type VAR_UNKNOWN.
639  */
640     varnumber_T
641 call_func_retnr(
642     char_u      *func,
643     int		argc,
644     typval_T	*argv)
645 {
646     typval_T	rettv;
647     varnumber_T	retval;
648 
649     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
650 	return -1;
651 
652     retval = tv_get_number_chk(&rettv, NULL);
653     clear_tv(&rettv);
654     return retval;
655 }
656 
657 /*
658  * Call Vim script function "func" and return the result as a string.
659  * Returns NULL when calling the function fails.
660  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
661  * have type VAR_UNKNOWN.
662  */
663     void *
664 call_func_retstr(
665     char_u      *func,
666     int		argc,
667     typval_T	*argv)
668 {
669     typval_T	rettv;
670     char_u	*retval;
671 
672     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
673 	return NULL;
674 
675     retval = vim_strsave(tv_get_string(&rettv));
676     clear_tv(&rettv);
677     return retval;
678 }
679 
680 /*
681  * Call Vim script function "func" and return the result as a List.
682  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
683  * have type VAR_UNKNOWN.
684  * Returns NULL when there is something wrong.
685  */
686     void *
687 call_func_retlist(
688     char_u      *func,
689     int		argc,
690     typval_T	*argv)
691 {
692     typval_T	rettv;
693 
694     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
695 	return NULL;
696 
697     if (rettv.v_type != VAR_LIST)
698     {
699 	clear_tv(&rettv);
700 	return NULL;
701     }
702 
703     return rettv.vval.v_list;
704 }
705 
706 #ifdef FEAT_FOLDING
707 /*
708  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
709  * it in "*cp".  Doesn't give error messages.
710  */
711     int
712 eval_foldexpr(char_u *arg, int *cp)
713 {
714     typval_T	tv;
715     varnumber_T	retval;
716     char_u	*s;
717     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
718 								   OPT_LOCAL);
719 
720     ++emsg_off;
721     if (use_sandbox)
722 	++sandbox;
723     ++textwinlock;
724     *cp = NUL;
725     if (eval0(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
726 	retval = 0;
727     else
728     {
729 	// If the result is a number, just return the number.
730 	if (tv.v_type == VAR_NUMBER)
731 	    retval = tv.vval.v_number;
732 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
733 	    retval = 0;
734 	else
735 	{
736 	    // If the result is a string, check if there is a non-digit before
737 	    // the number.
738 	    s = tv.vval.v_string;
739 	    if (!VIM_ISDIGIT(*s) && *s != '-')
740 		*cp = *s++;
741 	    retval = atol((char *)s);
742 	}
743 	clear_tv(&tv);
744     }
745     --emsg_off;
746     if (use_sandbox)
747 	--sandbox;
748     --textwinlock;
749     clear_evalarg(&EVALARG_EVALUATE, NULL);
750 
751     return (int)retval;
752 }
753 #endif
754 
755 /*
756  * Get an lval: variable, Dict item or List item that can be assigned a value
757  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
758  * "name.key", "name.key[expr]" etc.
759  * Indexing only works if "name" is an existing List or Dictionary.
760  * "name" points to the start of the name.
761  * If "rettv" is not NULL it points to the value to be assigned.
762  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
763  * wrong; must end in space or cmd separator.
764  *
765  * flags:
766  *  GLV_QUIET:       do not give error messages
767  *  GLV_READ_ONLY:   will not change the variable
768  *  GLV_NO_AUTOLOAD: do not use script autoloading
769  *
770  * Returns a pointer to just after the name, including indexes.
771  * When an evaluation error occurs "lp->ll_name" is NULL;
772  * Returns NULL for a parsing error.  Still need to free items in "lp"!
773  */
774     char_u *
775 get_lval(
776     char_u	*name,
777     typval_T	*rettv,
778     lval_T	*lp,
779     int		unlet,
780     int		skip,
781     int		flags,	    // GLV_ values
782     int		fne_flags)  // flags for find_name_end()
783 {
784     char_u	*p;
785     char_u	*expr_start, *expr_end;
786     int		cc;
787     dictitem_T	*v;
788     typval_T	var1;
789     typval_T	var2;
790     int		empty1 = FALSE;
791     listitem_T	*ni;
792     char_u	*key = NULL;
793     int		len;
794     hashtab_T	*ht = NULL;
795     int		quiet = flags & GLV_QUIET;
796 
797     // Clear everything in "lp".
798     CLEAR_POINTER(lp);
799 
800     if (skip)
801     {
802 	// When skipping just find the end of the name.
803 	lp->ll_name = name;
804 	lp->ll_name_end = find_name_end(name, NULL, NULL,
805 						      FNE_INCL_BR | fne_flags);
806 	return lp->ll_name_end;
807     }
808 
809     // Find the end of the name.
810     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
811     lp->ll_name_end = p;
812     if (expr_start != NULL)
813     {
814 	// Don't expand the name when we already know there is an error.
815 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
816 						    && *p != '[' && *p != '.')
817 	{
818 	    semsg(_(e_trailing_arg), p);
819 	    return NULL;
820 	}
821 
822 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
823 	if (lp->ll_exp_name == NULL)
824 	{
825 	    // Report an invalid expression in braces, unless the
826 	    // expression evaluation has been cancelled due to an
827 	    // aborting error, an interrupt, or an exception.
828 	    if (!aborting() && !quiet)
829 	    {
830 		emsg_severe = TRUE;
831 		semsg(_(e_invarg2), name);
832 		return NULL;
833 	    }
834 	}
835 	lp->ll_name = lp->ll_exp_name;
836     }
837     else
838     {
839 	lp->ll_name = name;
840 
841 	if (in_vim9script())
842 	{
843 	    // "a: type" is declaring variable "a" with a type, not "a:".
844 	    if (p == name + 2 && p[-1] == ':')
845 	    {
846 		--p;
847 		lp->ll_name_end = p;
848 	    }
849 	    if (*p == ':')
850 	    {
851 		scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);
852 		char_u	 *tp = skipwhite(p + 1);
853 
854 		// parse the type after the name
855 		lp->ll_type = parse_type(&tp, &si->sn_type_list);
856 		lp->ll_name_end = tp;
857 	    }
858 	}
859     }
860 
861     // Without [idx] or .key we are done.
862     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
863 	return p;
864 
865     cc = *p;
866     *p = NUL;
867     // Only pass &ht when we would write to the variable, it prevents autoload
868     // as well.
869     v = find_var(lp->ll_name, (flags & GLV_READ_ONLY) ? NULL : &ht,
870 						      flags & GLV_NO_AUTOLOAD);
871     if (v == NULL && !quiet)
872 	semsg(_(e_undefined_variable_str), lp->ll_name);
873     *p = cc;
874     if (v == NULL)
875 	return NULL;
876 
877     /*
878      * Loop until no more [idx] or .key is following.
879      */
880     lp->ll_tv = &v->di_tv;
881     var1.v_type = VAR_UNKNOWN;
882     var2.v_type = VAR_UNKNOWN;
883     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
884     {
885 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
886 		&& !(lp->ll_tv->v_type == VAR_DICT)
887 		&& !(lp->ll_tv->v_type == VAR_BLOB
888 					   && lp->ll_tv->vval.v_blob != NULL))
889 	{
890 	    if (!quiet)
891 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
892 	    return NULL;
893 	}
894 	if (lp->ll_range)
895 	{
896 	    if (!quiet)
897 		emsg(_("E708: [:] must come last"));
898 	    return NULL;
899 	}
900 
901 	if (in_vim9script() && lp->ll_valtype == NULL
902 		&& lp->ll_tv == &v->di_tv
903 		&& ht != NULL && ht == get_script_local_ht())
904 	{
905 	    svar_T  *sv = find_typval_in_script(lp->ll_tv);
906 
907 	    // Vim9 script local variable: get the type
908 	    if (sv != NULL)
909 		lp->ll_valtype = sv->sv_type;
910 	}
911 
912 	len = -1;
913 	if (*p == '.')
914 	{
915 	    key = p + 1;
916 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
917 		;
918 	    if (len == 0)
919 	    {
920 		if (!quiet)
921 		    emsg(_(e_emptykey));
922 		return NULL;
923 	    }
924 	    p = key + len;
925 	}
926 	else
927 	{
928 	    // Get the index [expr] or the first index [expr: ].
929 	    p = skipwhite(p + 1);
930 	    if (*p == ':')
931 		empty1 = TRUE;
932 	    else
933 	    {
934 		empty1 = FALSE;
935 		if (eval1(&p, &var1, &EVALARG_EVALUATE) == FAIL)  // recursive!
936 		    return NULL;
937 		if (tv_get_string_chk(&var1) == NULL)
938 		{
939 		    // not a number or string
940 		    clear_tv(&var1);
941 		    return NULL;
942 		}
943 		p = skipwhite(p);
944 	    }
945 
946 	    // Optionally get the second index [ :expr].
947 	    if (*p == ':')
948 	    {
949 		if (lp->ll_tv->v_type == VAR_DICT)
950 		{
951 		    if (!quiet)
952 			emsg(_(e_cannot_slice_dictionary));
953 		    clear_tv(&var1);
954 		    return NULL;
955 		}
956 		if (rettv != NULL
957 			&& !(rettv->v_type == VAR_LIST
958 						 && rettv->vval.v_list != NULL)
959 			&& !(rettv->v_type == VAR_BLOB
960 						&& rettv->vval.v_blob != NULL))
961 		{
962 		    if (!quiet)
963 			emsg(_("E709: [:] requires a List or Blob value"));
964 		    clear_tv(&var1);
965 		    return NULL;
966 		}
967 		p = skipwhite(p + 1);
968 		if (*p == ']')
969 		    lp->ll_empty2 = TRUE;
970 		else
971 		{
972 		    lp->ll_empty2 = FALSE;
973 		    // recursive!
974 		    if (eval1(&p, &var2, &EVALARG_EVALUATE) == FAIL)
975 		    {
976 			clear_tv(&var1);
977 			return NULL;
978 		    }
979 		    if (tv_get_string_chk(&var2) == NULL)
980 		    {
981 			// not a number or string
982 			clear_tv(&var1);
983 			clear_tv(&var2);
984 			return NULL;
985 		    }
986 		}
987 		lp->ll_range = TRUE;
988 	    }
989 	    else
990 		lp->ll_range = FALSE;
991 
992 	    if (*p != ']')
993 	    {
994 		if (!quiet)
995 		    emsg(_(e_missbrac));
996 		clear_tv(&var1);
997 		clear_tv(&var2);
998 		return NULL;
999 	    }
1000 
1001 	    // Skip to past ']'.
1002 	    ++p;
1003 	}
1004 
1005 	if (lp->ll_tv->v_type == VAR_DICT)
1006 	{
1007 	    if (len == -1)
1008 	    {
1009 		// "[key]": get key from "var1"
1010 		key = tv_get_string_chk(&var1);	// is number or string
1011 		if (key == NULL)
1012 		{
1013 		    clear_tv(&var1);
1014 		    return NULL;
1015 		}
1016 	    }
1017 	    lp->ll_list = NULL;
1018 
1019 	    // a NULL dict is equivalent with an empty dict
1020 	    if (lp->ll_tv->vval.v_dict == NULL)
1021 	    {
1022 		lp->ll_tv->vval.v_dict = dict_alloc();
1023 		if (lp->ll_tv->vval.v_dict == NULL)
1024 		{
1025 		    clear_tv(&var1);
1026 		    return NULL;
1027 		}
1028 		++lp->ll_tv->vval.v_dict->dv_refcount;
1029 	    }
1030 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
1031 
1032 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
1033 
1034 	    // When assigning to a scope dictionary check that a function and
1035 	    // variable name is valid (only variable name unless it is l: or
1036 	    // g: dictionary). Disallow overwriting a builtin function.
1037 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
1038 	    {
1039 		int prevval;
1040 		int wrong;
1041 
1042 		if (len != -1)
1043 		{
1044 		    prevval = key[len];
1045 		    key[len] = NUL;
1046 		}
1047 		else
1048 		    prevval = 0; // avoid compiler warning
1049 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
1050 			       && rettv->v_type == VAR_FUNC
1051 			       && var_wrong_func_name(key, lp->ll_di == NULL))
1052 			|| !valid_varname(key);
1053 		if (len != -1)
1054 		    key[len] = prevval;
1055 		if (wrong)
1056 		{
1057 		    clear_tv(&var1);
1058 		    return NULL;
1059 		}
1060 	    }
1061 
1062 	    if (lp->ll_valtype != NULL)
1063 		// use the type of the member
1064 		lp->ll_valtype = lp->ll_valtype->tt_member;
1065 
1066 	    if (lp->ll_di == NULL)
1067 	    {
1068 		// Can't add "v:" or "a:" variable.
1069 		if (lp->ll_dict == get_vimvar_dict()
1070 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
1071 		{
1072 		    semsg(_(e_illvar), name);
1073 		    clear_tv(&var1);
1074 		    return NULL;
1075 		}
1076 
1077 		// Key does not exist in dict: may need to add it.
1078 		if (*p == '[' || *p == '.' || unlet)
1079 		{
1080 		    if (!quiet)
1081 			semsg(_(e_dictkey), key);
1082 		    clear_tv(&var1);
1083 		    return NULL;
1084 		}
1085 		if (len == -1)
1086 		    lp->ll_newkey = vim_strsave(key);
1087 		else
1088 		    lp->ll_newkey = vim_strnsave(key, len);
1089 		clear_tv(&var1);
1090 		if (lp->ll_newkey == NULL)
1091 		    p = NULL;
1092 		break;
1093 	    }
1094 	    // existing variable, need to check if it can be changed
1095 	    else if ((flags & GLV_READ_ONLY) == 0
1096 			&& (var_check_ro(lp->ll_di->di_flags, name, FALSE)
1097 			  || var_check_lock(lp->ll_di->di_flags, name, FALSE)))
1098 	    {
1099 		clear_tv(&var1);
1100 		return NULL;
1101 	    }
1102 
1103 	    clear_tv(&var1);
1104 	    lp->ll_tv = &lp->ll_di->di_tv;
1105 	}
1106 	else if (lp->ll_tv->v_type == VAR_BLOB)
1107 	{
1108 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
1109 
1110 	    /*
1111 	     * Get the number and item for the only or first index of the List.
1112 	     */
1113 	    if (empty1)
1114 		lp->ll_n1 = 0;
1115 	    else
1116 		// is number or string
1117 		lp->ll_n1 = (long)tv_get_number(&var1);
1118 	    clear_tv(&var1);
1119 
1120 	    if (lp->ll_n1 < 0
1121 		    || lp->ll_n1 > bloblen
1122 		    || (lp->ll_range && lp->ll_n1 == bloblen))
1123 	    {
1124 		if (!quiet)
1125 		    semsg(_(e_blobidx), lp->ll_n1);
1126 		clear_tv(&var2);
1127 		return NULL;
1128 	    }
1129 	    if (lp->ll_range && !lp->ll_empty2)
1130 	    {
1131 		lp->ll_n2 = (long)tv_get_number(&var2);
1132 		clear_tv(&var2);
1133 		if (lp->ll_n2 < 0
1134 			|| lp->ll_n2 >= bloblen
1135 			|| lp->ll_n2 < lp->ll_n1)
1136 		{
1137 		    if (!quiet)
1138 			semsg(_(e_blobidx), lp->ll_n2);
1139 		    return NULL;
1140 		}
1141 	    }
1142 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
1143 	    lp->ll_tv = NULL;
1144 	    break;
1145 	}
1146 	else
1147 	{
1148 	    /*
1149 	     * Get the number and item for the only or first index of the List.
1150 	     */
1151 	    if (empty1)
1152 		lp->ll_n1 = 0;
1153 	    else
1154 		// is number or string
1155 		lp->ll_n1 = (long)tv_get_number(&var1);
1156 	    clear_tv(&var1);
1157 
1158 	    lp->ll_dict = NULL;
1159 	    lp->ll_list = lp->ll_tv->vval.v_list;
1160 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
1161 	    if (lp->ll_li == NULL)
1162 	    {
1163 		if (lp->ll_n1 < 0)
1164 		{
1165 		    lp->ll_n1 = 0;
1166 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
1167 		}
1168 	    }
1169 	    if (lp->ll_li == NULL)
1170 	    {
1171 		clear_tv(&var2);
1172 		if (!quiet)
1173 		    semsg(_(e_listidx), lp->ll_n1);
1174 		return NULL;
1175 	    }
1176 
1177 	    if (lp->ll_valtype != NULL)
1178 		// use the type of the member
1179 		lp->ll_valtype = lp->ll_valtype->tt_member;
1180 
1181 	    /*
1182 	     * May need to find the item or absolute index for the second
1183 	     * index of a range.
1184 	     * When no index given: "lp->ll_empty2" is TRUE.
1185 	     * Otherwise "lp->ll_n2" is set to the second index.
1186 	     */
1187 	    if (lp->ll_range && !lp->ll_empty2)
1188 	    {
1189 		lp->ll_n2 = (long)tv_get_number(&var2);
1190 						    // is number or string
1191 		clear_tv(&var2);
1192 		if (lp->ll_n2 < 0)
1193 		{
1194 		    ni = list_find(lp->ll_list, lp->ll_n2);
1195 		    if (ni == NULL)
1196 		    {
1197 			if (!quiet)
1198 			    semsg(_(e_listidx), lp->ll_n2);
1199 			return NULL;
1200 		    }
1201 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
1202 		}
1203 
1204 		// Check that lp->ll_n2 isn't before lp->ll_n1.
1205 		if (lp->ll_n1 < 0)
1206 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
1207 		if (lp->ll_n2 < lp->ll_n1)
1208 		{
1209 		    if (!quiet)
1210 			semsg(_(e_listidx), lp->ll_n2);
1211 		    return NULL;
1212 		}
1213 	    }
1214 
1215 	    lp->ll_tv = &lp->ll_li->li_tv;
1216 	}
1217     }
1218 
1219     clear_tv(&var1);
1220     lp->ll_name_end = p;
1221     return p;
1222 }
1223 
1224 /*
1225  * Clear lval "lp" that was filled by get_lval().
1226  */
1227     void
1228 clear_lval(lval_T *lp)
1229 {
1230     vim_free(lp->ll_exp_name);
1231     vim_free(lp->ll_newkey);
1232 }
1233 
1234 /*
1235  * Set a variable that was parsed by get_lval() to "rettv".
1236  * "endp" points to just after the parsed name.
1237  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
1238  * "%" for "%=", "." for ".=" or "=" for "=".
1239  */
1240     void
1241 set_var_lval(
1242     lval_T	*lp,
1243     char_u	*endp,
1244     typval_T	*rettv,
1245     int		copy,
1246     int		flags,    // ASSIGN_CONST, ASSIGN_NO_DECL
1247     char_u	*op)
1248 {
1249     int		cc;
1250     listitem_T	*ri;
1251     dictitem_T	*di;
1252 
1253     if (lp->ll_tv == NULL)
1254     {
1255 	cc = *endp;
1256 	*endp = NUL;
1257 	if (lp->ll_blob != NULL)
1258 	{
1259 	    int	    error = FALSE, val;
1260 
1261 	    if (op != NULL && *op != '=')
1262 	    {
1263 		semsg(_(e_letwrong), op);
1264 		return;
1265 	    }
1266 	    if (value_check_lock(lp->ll_blob->bv_lock, lp->ll_name, FALSE))
1267 		return;
1268 
1269 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
1270 	    {
1271 		int	il, ir;
1272 
1273 		if (lp->ll_empty2)
1274 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
1275 
1276 		if (lp->ll_n2 - lp->ll_n1 + 1 != blob_len(rettv->vval.v_blob))
1277 		{
1278 		    emsg(_("E972: Blob value does not have the right number of bytes"));
1279 		    return;
1280 		}
1281 		if (lp->ll_empty2)
1282 		    lp->ll_n2 = blob_len(lp->ll_blob);
1283 
1284 		ir = 0;
1285 		for (il = lp->ll_n1; il <= lp->ll_n2; il++)
1286 		    blob_set(lp->ll_blob, il,
1287 			    blob_get(rettv->vval.v_blob, ir++));
1288 	    }
1289 	    else
1290 	    {
1291 		val = (int)tv_get_number_chk(rettv, &error);
1292 		if (!error)
1293 		{
1294 		    garray_T *gap = &lp->ll_blob->bv_ga;
1295 
1296 		    // Allow for appending a byte.  Setting a byte beyond
1297 		    // the end is an error otherwise.
1298 		    if (lp->ll_n1 < gap->ga_len
1299 			    || (lp->ll_n1 == gap->ga_len
1300 				&& ga_grow(&lp->ll_blob->bv_ga, 1) == OK))
1301 		    {
1302 			blob_set(lp->ll_blob, lp->ll_n1, val);
1303 			if (lp->ll_n1 == gap->ga_len)
1304 			    ++gap->ga_len;
1305 		    }
1306 		    // error for invalid range was already given in get_lval()
1307 		}
1308 	    }
1309 	}
1310 	else if (op != NULL && *op != '=')
1311 	{
1312 	    typval_T tv;
1313 
1314 	    if (flags & ASSIGN_CONST)
1315 	    {
1316 		emsg(_(e_cannot_mod));
1317 		*endp = cc;
1318 		return;
1319 	    }
1320 
1321 	    // handle +=, -=, *=, /=, %= and .=
1322 	    di = NULL;
1323 	    if (eval_variable(lp->ll_name, (int)STRLEN(lp->ll_name),
1324 					     &tv, &di, TRUE, FALSE) == OK)
1325 	    {
1326 		if ((di == NULL
1327 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
1328 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
1329 			&& tv_op(&tv, rettv, op) == OK)
1330 		    set_var(lp->ll_name, &tv, FALSE);
1331 		clear_tv(&tv);
1332 	    }
1333 	}
1334 	else
1335 	{
1336 	    if (lp->ll_type != NULL
1337 			   && check_typval_type(lp->ll_type, rettv, 0) == FAIL)
1338 		return;
1339 	    set_var_const(lp->ll_name, lp->ll_type, rettv, copy, flags);
1340 	}
1341 	*endp = cc;
1342     }
1343     else if (value_check_lock(lp->ll_newkey == NULL
1344 		? lp->ll_tv->v_lock
1345 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
1346 	;
1347     else if (lp->ll_range)
1348     {
1349 	listitem_T *ll_li = lp->ll_li;
1350 	int	    ll_n1 = lp->ll_n1;
1351 
1352 	if (flags & ASSIGN_CONST)
1353 	{
1354 	    emsg(_("E996: Cannot lock a range"));
1355 	    return;
1356 	}
1357 
1358 	/*
1359 	 * Check whether any of the list items is locked
1360 	 */
1361 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
1362 	{
1363 	    if (value_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
1364 		return;
1365 	    ri = ri->li_next;
1366 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
1367 		break;
1368 	    ll_li = ll_li->li_next;
1369 	    ++ll_n1;
1370 	}
1371 
1372 	/*
1373 	 * Assign the List values to the list items.
1374 	 */
1375 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
1376 	{
1377 	    if (op != NULL && *op != '=')
1378 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
1379 	    else
1380 	    {
1381 		clear_tv(&lp->ll_li->li_tv);
1382 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
1383 	    }
1384 	    ri = ri->li_next;
1385 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
1386 		break;
1387 	    if (lp->ll_li->li_next == NULL)
1388 	    {
1389 		// Need to add an empty item.
1390 		if (list_append_number(lp->ll_list, 0) == FAIL)
1391 		{
1392 		    ri = NULL;
1393 		    break;
1394 		}
1395 	    }
1396 	    lp->ll_li = lp->ll_li->li_next;
1397 	    ++lp->ll_n1;
1398 	}
1399 	if (ri != NULL)
1400 	    emsg(_(e_list_value_has_more_items_than_targets));
1401 	else if (lp->ll_empty2
1402 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
1403 		: lp->ll_n1 != lp->ll_n2)
1404 	    emsg(_(e_list_value_does_not_have_enough_items));
1405     }
1406     else
1407     {
1408 	/*
1409 	 * Assign to a List or Dictionary item.
1410 	 */
1411 	if (flags & ASSIGN_CONST)
1412 	{
1413 	    emsg(_("E996: Cannot lock a list or dict"));
1414 	    return;
1415 	}
1416 
1417 	if (lp->ll_valtype != NULL
1418 			&& check_typval_type(lp->ll_valtype, rettv, 0) == FAIL)
1419 	    return;
1420 
1421 	if (lp->ll_newkey != NULL)
1422 	{
1423 	    if (op != NULL && *op != '=')
1424 	    {
1425 		semsg(_(e_letwrong), op);
1426 		return;
1427 	    }
1428 
1429 	    // Need to add an item to the Dictionary.
1430 	    di = dictitem_alloc(lp->ll_newkey);
1431 	    if (di == NULL)
1432 		return;
1433 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
1434 	    {
1435 		vim_free(di);
1436 		return;
1437 	    }
1438 	    lp->ll_tv = &di->di_tv;
1439 	}
1440 	else if (op != NULL && *op != '=')
1441 	{
1442 	    tv_op(lp->ll_tv, rettv, op);
1443 	    return;
1444 	}
1445 	else
1446 	    clear_tv(lp->ll_tv);
1447 
1448 	/*
1449 	 * Assign the value to the variable or list item.
1450 	 */
1451 	if (copy)
1452 	    copy_tv(rettv, lp->ll_tv);
1453 	else
1454 	{
1455 	    *lp->ll_tv = *rettv;
1456 	    lp->ll_tv->v_lock = 0;
1457 	    init_tv(rettv);
1458 	}
1459     }
1460 }
1461 
1462 /*
1463  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
1464  * and "tv1 .= tv2"
1465  * Returns OK or FAIL.
1466  */
1467     static int
1468 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
1469 {
1470     varnumber_T	n;
1471     char_u	numbuf[NUMBUFLEN];
1472     char_u	*s;
1473 
1474     // Can't do anything with a Funcref, Dict, v:true on the right.
1475     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
1476 		      && tv2->v_type != VAR_BOOL && tv2->v_type != VAR_SPECIAL)
1477     {
1478 	switch (tv1->v_type)
1479 	{
1480 	    case VAR_UNKNOWN:
1481 	    case VAR_ANY:
1482 	    case VAR_VOID:
1483 	    case VAR_DICT:
1484 	    case VAR_FUNC:
1485 	    case VAR_PARTIAL:
1486 	    case VAR_BOOL:
1487 	    case VAR_SPECIAL:
1488 	    case VAR_JOB:
1489 	    case VAR_CHANNEL:
1490 		break;
1491 
1492 	    case VAR_BLOB:
1493 		if (*op != '+' || tv2->v_type != VAR_BLOB)
1494 		    break;
1495 		// BLOB += BLOB
1496 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
1497 		{
1498 		    blob_T  *b1 = tv1->vval.v_blob;
1499 		    blob_T  *b2 = tv2->vval.v_blob;
1500 		    int	i, len = blob_len(b2);
1501 		    for (i = 0; i < len; i++)
1502 			ga_append(&b1->bv_ga, blob_get(b2, i));
1503 		}
1504 		return OK;
1505 
1506 	    case VAR_LIST:
1507 		if (*op != '+' || tv2->v_type != VAR_LIST)
1508 		    break;
1509 		// List += List
1510 		if (tv2->vval.v_list != NULL)
1511 		{
1512 		    if (tv1->vval.v_list == NULL)
1513 		    {
1514 			tv1->vval.v_list = tv2->vval.v_list;
1515 			++tv1->vval.v_list->lv_refcount;
1516 		    }
1517 		    else
1518 			list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
1519 		}
1520 		return OK;
1521 
1522 	    case VAR_NUMBER:
1523 	    case VAR_STRING:
1524 		if (tv2->v_type == VAR_LIST)
1525 		    break;
1526 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
1527 		{
1528 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
1529 		    n = tv_get_number(tv1);
1530 #ifdef FEAT_FLOAT
1531 		    if (tv2->v_type == VAR_FLOAT)
1532 		    {
1533 			float_T f = n;
1534 
1535 			if (*op == '%')
1536 			    break;
1537 			switch (*op)
1538 			{
1539 			    case '+': f += tv2->vval.v_float; break;
1540 			    case '-': f -= tv2->vval.v_float; break;
1541 			    case '*': f *= tv2->vval.v_float; break;
1542 			    case '/': f /= tv2->vval.v_float; break;
1543 			}
1544 			clear_tv(tv1);
1545 			tv1->v_type = VAR_FLOAT;
1546 			tv1->vval.v_float = f;
1547 		    }
1548 		    else
1549 #endif
1550 		    {
1551 			switch (*op)
1552 			{
1553 			    case '+': n += tv_get_number(tv2); break;
1554 			    case '-': n -= tv_get_number(tv2); break;
1555 			    case '*': n *= tv_get_number(tv2); break;
1556 			    case '/': n = num_divide(n, tv_get_number(tv2)); break;
1557 			    case '%': n = num_modulus(n, tv_get_number(tv2)); break;
1558 			}
1559 			clear_tv(tv1);
1560 			tv1->v_type = VAR_NUMBER;
1561 			tv1->vval.v_number = n;
1562 		    }
1563 		}
1564 		else
1565 		{
1566 		    if (tv2->v_type == VAR_FLOAT)
1567 			break;
1568 
1569 		    // str .= str
1570 		    s = tv_get_string(tv1);
1571 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
1572 		    clear_tv(tv1);
1573 		    tv1->v_type = VAR_STRING;
1574 		    tv1->vval.v_string = s;
1575 		}
1576 		return OK;
1577 
1578 	    case VAR_FLOAT:
1579 #ifdef FEAT_FLOAT
1580 		{
1581 		    float_T f;
1582 
1583 		    if (*op == '%' || *op == '.'
1584 				   || (tv2->v_type != VAR_FLOAT
1585 				    && tv2->v_type != VAR_NUMBER
1586 				    && tv2->v_type != VAR_STRING))
1587 			break;
1588 		    if (tv2->v_type == VAR_FLOAT)
1589 			f = tv2->vval.v_float;
1590 		    else
1591 			f = tv_get_number(tv2);
1592 		    switch (*op)
1593 		    {
1594 			case '+': tv1->vval.v_float += f; break;
1595 			case '-': tv1->vval.v_float -= f; break;
1596 			case '*': tv1->vval.v_float *= f; break;
1597 			case '/': tv1->vval.v_float /= f; break;
1598 		    }
1599 		}
1600 #endif
1601 		return OK;
1602 	}
1603     }
1604 
1605     semsg(_(e_letwrong), op);
1606     return FAIL;
1607 }
1608 
1609 /*
1610  * Evaluate the expression used in a ":for var in expr" command.
1611  * "arg" points to "var".
1612  * Set "*errp" to TRUE for an error, FALSE otherwise;
1613  * Return a pointer that holds the info.  Null when there is an error.
1614  */
1615     void *
1616 eval_for_line(
1617     char_u	*arg,
1618     int		*errp,
1619     exarg_T	*eap,
1620     evalarg_T	*evalarg)
1621 {
1622     forinfo_T	*fi;
1623     char_u	*expr;
1624     typval_T	tv;
1625     list_T	*l;
1626     int		skip = !(evalarg->eval_flags & EVAL_EVALUATE);
1627 
1628     *errp = TRUE;	// default: there is an error
1629 
1630     fi = ALLOC_CLEAR_ONE(forinfo_T);
1631     if (fi == NULL)
1632 	return NULL;
1633 
1634     expr = skip_var_list(arg, TRUE, &fi->fi_varcount, &fi->fi_semicolon, FALSE);
1635     if (expr == NULL)
1636 	return fi;
1637 
1638     expr = skipwhite_and_linebreak(expr, evalarg);
1639     if (expr[0] != 'i' || expr[1] != 'n'
1640 				  || !(expr[2] == NUL || VIM_ISWHITE(expr[2])))
1641     {
1642 	emsg(_(e_missing_in));
1643 	return fi;
1644     }
1645 
1646     if (skip)
1647 	++emsg_skip;
1648     expr = skipwhite_and_linebreak(expr + 2, evalarg);
1649     if (eval0(expr, &tv, eap, evalarg) == OK)
1650     {
1651 	*errp = FALSE;
1652 	if (!skip)
1653 	{
1654 	    if (tv.v_type == VAR_LIST)
1655 	    {
1656 		l = tv.vval.v_list;
1657 		if (l == NULL)
1658 		{
1659 		    // a null list is like an empty list: do nothing
1660 		    clear_tv(&tv);
1661 		}
1662 		else
1663 		{
1664 		    // Need a real list here.
1665 		    CHECK_LIST_MATERIALIZE(l);
1666 
1667 		    // No need to increment the refcount, it's already set for
1668 		    // the list being used in "tv".
1669 		    fi->fi_list = l;
1670 		    list_add_watch(l, &fi->fi_lw);
1671 		    fi->fi_lw.lw_item = l->lv_first;
1672 		}
1673 	    }
1674 	    else if (tv.v_type == VAR_BLOB)
1675 	    {
1676 		fi->fi_bi = 0;
1677 		if (tv.vval.v_blob != NULL)
1678 		{
1679 		    typval_T btv;
1680 
1681 		    // Make a copy, so that the iteration still works when the
1682 		    // blob is changed.
1683 		    blob_copy(tv.vval.v_blob, &btv);
1684 		    fi->fi_blob = btv.vval.v_blob;
1685 		}
1686 		clear_tv(&tv);
1687 	    }
1688 	    else
1689 	    {
1690 		emsg(_(e_listreq));
1691 		clear_tv(&tv);
1692 	    }
1693 	}
1694     }
1695     if (skip)
1696 	--emsg_skip;
1697     fi->fi_break_count = evalarg->eval_break_count;
1698 
1699     return fi;
1700 }
1701 
1702 /*
1703  * Used when looping over a :for line, skip the "in expr" part.
1704  */
1705     void
1706 skip_for_lines(void *fi_void, evalarg_T *evalarg)
1707 {
1708     forinfo_T	*fi = (forinfo_T *)fi_void;
1709     int		i;
1710 
1711     for (i = 0; i < fi->fi_break_count; ++i)
1712 	eval_next_line(evalarg);
1713 }
1714 
1715 /*
1716  * Use the first item in a ":for" list.  Advance to the next.
1717  * Assign the values to the variable (list).  "arg" points to the first one.
1718  * Return TRUE when a valid item was found, FALSE when at end of list or
1719  * something wrong.
1720  */
1721     int
1722 next_for_item(void *fi_void, char_u *arg)
1723 {
1724     forinfo_T	*fi = (forinfo_T *)fi_void;
1725     int		result;
1726     int		flag = in_vim9script() ?  ASSIGN_NO_DECL : 0;
1727     listitem_T	*item;
1728 
1729     if (fi->fi_blob != NULL)
1730     {
1731 	typval_T	tv;
1732 
1733 	if (fi->fi_bi >= blob_len(fi->fi_blob))
1734 	    return FALSE;
1735 	tv.v_type = VAR_NUMBER;
1736 	tv.v_lock = VAR_FIXED;
1737 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
1738 	++fi->fi_bi;
1739 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1740 				       fi->fi_varcount, flag, NULL) == OK;
1741     }
1742 
1743     item = fi->fi_lw.lw_item;
1744     if (item == NULL)
1745 	result = FALSE;
1746     else
1747     {
1748 	fi->fi_lw.lw_item = item->li_next;
1749 	result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
1750 				      fi->fi_varcount, flag, NULL) == OK);
1751     }
1752     return result;
1753 }
1754 
1755 /*
1756  * Free the structure used to store info used by ":for".
1757  */
1758     void
1759 free_for_info(void *fi_void)
1760 {
1761     forinfo_T    *fi = (forinfo_T *)fi_void;
1762 
1763     if (fi != NULL && fi->fi_list != NULL)
1764     {
1765 	list_rem_watch(fi->fi_list, &fi->fi_lw);
1766 	list_unref(fi->fi_list);
1767     }
1768     if (fi != NULL && fi->fi_blob != NULL)
1769 	blob_unref(fi->fi_blob);
1770     vim_free(fi);
1771 }
1772 
1773     void
1774 set_context_for_expression(
1775     expand_T	*xp,
1776     char_u	*arg,
1777     cmdidx_T	cmdidx)
1778 {
1779     int		has_expr = cmdidx != CMD_let && cmdidx != CMD_var;
1780     int		c;
1781     char_u	*p;
1782 
1783     if (cmdidx == CMD_let || cmdidx == CMD_var
1784 				 || cmdidx == CMD_const || cmdidx == CMD_final)
1785     {
1786 	xp->xp_context = EXPAND_USER_VARS;
1787 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
1788 	{
1789 	    // ":let var1 var2 ...": find last space.
1790 	    for (p = arg + STRLEN(arg); p >= arg; )
1791 	    {
1792 		xp->xp_pattern = p;
1793 		MB_PTR_BACK(arg, p);
1794 		if (VIM_ISWHITE(*p))
1795 		    break;
1796 	    }
1797 	    return;
1798 	}
1799     }
1800     else
1801 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
1802 							  : EXPAND_EXPRESSION;
1803     while ((xp->xp_pattern = vim_strpbrk(arg,
1804 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
1805     {
1806 	c = *xp->xp_pattern;
1807 	if (c == '&')
1808 	{
1809 	    c = xp->xp_pattern[1];
1810 	    if (c == '&')
1811 	    {
1812 		++xp->xp_pattern;
1813 		xp->xp_context = has_expr ? EXPAND_EXPRESSION : EXPAND_NOTHING;
1814 	    }
1815 	    else if (c != ' ')
1816 	    {
1817 		xp->xp_context = EXPAND_SETTINGS;
1818 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
1819 		    xp->xp_pattern += 2;
1820 
1821 	    }
1822 	}
1823 	else if (c == '$')
1824 	{
1825 	    // environment variable
1826 	    xp->xp_context = EXPAND_ENV_VARS;
1827 	}
1828 	else if (c == '=')
1829 	{
1830 	    has_expr = TRUE;
1831 	    xp->xp_context = EXPAND_EXPRESSION;
1832 	}
1833 	else if (c == '#'
1834 		&& xp->xp_context == EXPAND_EXPRESSION)
1835 	{
1836 	    // Autoload function/variable contains '#'.
1837 	    break;
1838 	}
1839 	else if ((c == '<' || c == '#')
1840 		&& xp->xp_context == EXPAND_FUNCTIONS
1841 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
1842 	{
1843 	    // Function name can start with "<SNR>" and contain '#'.
1844 	    break;
1845 	}
1846 	else if (has_expr)
1847 	{
1848 	    if (c == '"')	    // string
1849 	    {
1850 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
1851 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
1852 			++xp->xp_pattern;
1853 		xp->xp_context = EXPAND_NOTHING;
1854 	    }
1855 	    else if (c == '\'')	    // literal string
1856 	    {
1857 		// Trick: '' is like stopping and starting a literal string.
1858 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
1859 		    /* skip */ ;
1860 		xp->xp_context = EXPAND_NOTHING;
1861 	    }
1862 	    else if (c == '|')
1863 	    {
1864 		if (xp->xp_pattern[1] == '|')
1865 		{
1866 		    ++xp->xp_pattern;
1867 		    xp->xp_context = EXPAND_EXPRESSION;
1868 		}
1869 		else
1870 		    xp->xp_context = EXPAND_COMMANDS;
1871 	    }
1872 	    else
1873 		xp->xp_context = EXPAND_EXPRESSION;
1874 	}
1875 	else
1876 	    // Doesn't look like something valid, expand as an expression
1877 	    // anyway.
1878 	    xp->xp_context = EXPAND_EXPRESSION;
1879 	arg = xp->xp_pattern;
1880 	if (*arg != NUL)
1881 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
1882 		/* skip */ ;
1883     }
1884     xp->xp_pattern = arg;
1885 }
1886 
1887 /*
1888  * Return TRUE if "pat" matches "text".
1889  * Does not use 'cpo' and always uses 'magic'.
1890  */
1891     int
1892 pattern_match(char_u *pat, char_u *text, int ic)
1893 {
1894     int		matches = FALSE;
1895     char_u	*save_cpo;
1896     regmatch_T	regmatch;
1897 
1898     // avoid 'l' flag in 'cpoptions'
1899     save_cpo = p_cpo;
1900     p_cpo = (char_u *)"";
1901     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1902     if (regmatch.regprog != NULL)
1903     {
1904 	regmatch.rm_ic = ic;
1905 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
1906 	vim_regfree(regmatch.regprog);
1907     }
1908     p_cpo = save_cpo;
1909     return matches;
1910 }
1911 
1912 /*
1913  * Handle a name followed by "(".  Both for just "name(arg)" and for
1914  * "expr->name(arg)".
1915  * Returns OK or FAIL.
1916  */
1917     static int
1918 eval_func(
1919 	char_u	    **arg,	// points to "(", will be advanced
1920 	evalarg_T   *evalarg,
1921 	char_u	    *name,
1922 	int	    name_len,
1923 	typval_T    *rettv,
1924 	int	    flags,
1925 	typval_T    *basetv)	// "expr" for "expr->name(arg)"
1926 {
1927     int		evaluate = flags & EVAL_EVALUATE;
1928     char_u	*s = name;
1929     int		len = name_len;
1930     partial_T	*partial;
1931     int		ret = OK;
1932 
1933     if (!evaluate)
1934 	check_vars(s, len);
1935 
1936     // If "s" is the name of a variable of type VAR_FUNC
1937     // use its contents.
1938     s = deref_func_name(s, &len, &partial, !evaluate);
1939 
1940     // Need to make a copy, in case evaluating the arguments makes
1941     // the name invalid.
1942     s = vim_strsave(s);
1943     if (s == NULL || (flags & EVAL_CONSTANT))
1944 	ret = FAIL;
1945     else
1946     {
1947 	funcexe_T funcexe;
1948 
1949 	// Invoke the function.
1950 	CLEAR_FIELD(funcexe);
1951 	funcexe.firstline = curwin->w_cursor.lnum;
1952 	funcexe.lastline = curwin->w_cursor.lnum;
1953 	funcexe.evaluate = evaluate;
1954 	funcexe.partial = partial;
1955 	funcexe.basetv = basetv;
1956 	ret = get_func_tv(s, len, rettv, arg, evalarg, &funcexe);
1957     }
1958     vim_free(s);
1959 
1960     // If evaluate is FALSE rettv->v_type was not set in
1961     // get_func_tv, but it's needed in handle_subscript() to parse
1962     // what follows. So set it here.
1963     if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
1964     {
1965 	rettv->vval.v_string = NULL;
1966 	rettv->v_type = VAR_FUNC;
1967     }
1968 
1969     // Stop the expression evaluation when immediately
1970     // aborting on error, or when an interrupt occurred or
1971     // an exception was thrown but not caught.
1972     if (evaluate && aborting())
1973     {
1974 	if (ret == OK)
1975 	    clear_tv(rettv);
1976 	ret = FAIL;
1977     }
1978     return ret;
1979 }
1980 
1981 /*
1982  * Get the next line source line without advancing.  But do skip over comment
1983  * lines.
1984  */
1985     static char_u *
1986 getline_peek_skip_comments(evalarg_T *evalarg)
1987 {
1988     for (;;)
1989     {
1990 	char_u *next = getline_peek(evalarg->eval_getline,
1991 							 evalarg->eval_cookie);
1992 	char_u *p;
1993 
1994 	if (next == NULL)
1995 	    break;
1996 	p = skipwhite(next);
1997 	if (*p != NUL && !vim9_comment_start(p))
1998 	    return next;
1999 	(void)eval_next_line(evalarg);
2000     }
2001     return NULL;
2002 }
2003 
2004 /*
2005  * If inside Vim9 script, "arg" points to the end of a line (ignoring a #
2006  * comment) and there is a next line, return the next line (skipping blanks)
2007  * and set "getnext".
2008  * Otherwise just return "arg" unmodified and set "getnext" to FALSE.
2009  * "arg" must point somewhere inside a line, not at the start.
2010  */
2011     char_u *
2012 eval_next_non_blank(char_u *arg, evalarg_T *evalarg, int *getnext)
2013 {
2014     char_u *p = skipwhite(arg);
2015 
2016     *getnext = FALSE;
2017     if (in_vim9script()
2018 	    && evalarg != NULL
2019 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL)
2020 	    && (*p == NUL || (VIM_ISWHITE(p[-1]) && vim9_comment_start(p))))
2021     {
2022 	char_u *next;
2023 
2024 	if (evalarg->eval_cookie != NULL)
2025 	    next = getline_peek_skip_comments(evalarg);
2026 	else
2027 	    next = peek_next_line_from_context(evalarg->eval_cctx);
2028 
2029 	if (next != NULL)
2030 	{
2031 	    *getnext = TRUE;
2032 	    return skipwhite(next);
2033 	}
2034     }
2035     return p;
2036 }
2037 
2038 /*
2039  * To be called after eval_next_non_blank() sets "getnext" to TRUE.
2040  */
2041     char_u *
2042 eval_next_line(evalarg_T *evalarg)
2043 {
2044     garray_T	*gap = &evalarg->eval_ga;
2045     char_u	*line;
2046 
2047     if (evalarg->eval_cookie != NULL)
2048 	line = evalarg->eval_getline(0, evalarg->eval_cookie, 0,
2049 							   GETLINE_CONCAT_ALL);
2050     else
2051 	line = next_line_from_context(evalarg->eval_cctx, TRUE);
2052     ++evalarg->eval_break_count;
2053     if (gap->ga_itemsize > 0 && ga_grow(gap, 1) == OK)
2054     {
2055 	// Going to concatenate the lines after parsing.
2056 	((char_u **)gap->ga_data)[gap->ga_len] = line;
2057 	++gap->ga_len;
2058     }
2059     else if (evalarg->eval_cookie != NULL)
2060     {
2061 	vim_free(evalarg->eval_tofree);
2062 	evalarg->eval_tofree = line;
2063     }
2064     return skipwhite(line);
2065 }
2066 
2067 /*
2068  * Call eval_next_non_blank() and get the next line if needed.
2069  */
2070     char_u *
2071 skipwhite_and_linebreak(char_u *arg, evalarg_T *evalarg)
2072 {
2073     int	    getnext;
2074     char_u  *p = skipwhite(arg);
2075 
2076     if (evalarg == NULL)
2077 	return skipwhite(arg);
2078     eval_next_non_blank(p, evalarg, &getnext);
2079     if (getnext)
2080 	return eval_next_line(evalarg);
2081     return p;
2082 }
2083 
2084 /*
2085  * After using "evalarg" filled from "eap": free the memory.
2086  */
2087     void
2088 clear_evalarg(evalarg_T *evalarg, exarg_T *eap)
2089 {
2090     if (evalarg != NULL)
2091     {
2092 	if (evalarg->eval_tofree != NULL)
2093 	{
2094 	    if (eap != NULL)
2095 	    {
2096 		// We may need to keep the original command line, e.g. for
2097 		// ":let" it has the variable names.  But we may also need the
2098 		// new one, "nextcmd" points into it.  Keep both.
2099 		vim_free(eap->cmdline_tofree);
2100 		eap->cmdline_tofree = *eap->cmdlinep;
2101 		*eap->cmdlinep = evalarg->eval_tofree;
2102 	    }
2103 	    else
2104 		vim_free(evalarg->eval_tofree);
2105 	    evalarg->eval_tofree = NULL;
2106 	}
2107 
2108 	vim_free(evalarg->eval_tofree_lambda);
2109 	evalarg->eval_tofree_lambda = NULL;
2110     }
2111 }
2112 
2113 /*
2114  * The "evaluate" argument: When FALSE, the argument is only parsed but not
2115  * executed.  The function may return OK, but the rettv will be of type
2116  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
2117  */
2118 
2119 /*
2120  * Handle zero level expression.
2121  * This calls eval1() and handles error message and nextcmd.
2122  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
2123  * Note: "rettv.v_lock" is not set.
2124  * "evalarg" can be NULL, EVALARG_EVALUATE or a pointer.
2125  * Return OK or FAIL.
2126  */
2127     int
2128 eval0(
2129     char_u	*arg,
2130     typval_T	*rettv,
2131     exarg_T	*eap,
2132     evalarg_T	*evalarg)
2133 {
2134     int		ret;
2135     char_u	*p;
2136     int		did_emsg_before = did_emsg;
2137     int		called_emsg_before = called_emsg;
2138     int		flags = evalarg == NULL ? 0 : evalarg->eval_flags;
2139 
2140     p = skipwhite(arg);
2141     ret = eval1(&p, rettv, evalarg);
2142     p = skipwhite(p);
2143 
2144     if (ret == FAIL || !ends_excmd2(arg, p))
2145     {
2146 	if (ret != FAIL)
2147 	    clear_tv(rettv);
2148 	/*
2149 	 * Report the invalid expression unless the expression evaluation has
2150 	 * been cancelled due to an aborting error, an interrupt, or an
2151 	 * exception, or we already gave a more specific error.
2152 	 * Also check called_emsg for when using assert_fails().
2153 	 */
2154 	if (!aborting()
2155 		&& did_emsg == did_emsg_before
2156 		&& called_emsg == called_emsg_before
2157 		&& (flags & EVAL_CONSTANT) == 0)
2158 	    semsg(_(e_invexpr2), arg);
2159 	ret = FAIL;
2160     }
2161 
2162     if (eap != NULL)
2163 	eap->nextcmd = check_nextcmd(p);
2164 
2165     return ret;
2166 }
2167 
2168 /*
2169  * Handle top level expression:
2170  *	expr2 ? expr1 : expr1
2171  *	expr2 ?? expr1
2172  *
2173  * "arg" must point to the first non-white of the expression.
2174  * "arg" is advanced to just after the recognized expression.
2175  *
2176  * Note: "rettv.v_lock" is not set.
2177  *
2178  * Return OK or FAIL.
2179  */
2180     int
2181 eval1(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2182 {
2183     char_u  *p;
2184     int	    getnext;
2185 
2186     CLEAR_POINTER(rettv);
2187 
2188     /*
2189      * Get the first variable.
2190      */
2191     if (eval2(arg, rettv, evalarg) == FAIL)
2192 	return FAIL;
2193 
2194     p = eval_next_non_blank(*arg, evalarg, &getnext);
2195     if (*p == '?')
2196     {
2197 	int		op_falsy = p[1] == '?';
2198 	int		result;
2199 	typval_T	var2;
2200 	evalarg_T	*evalarg_used = evalarg;
2201 	evalarg_T	local_evalarg;
2202 	int		orig_flags;
2203 	int		evaluate;
2204 	int		vim9script = in_vim9script();
2205 
2206 	if (evalarg == NULL)
2207 	{
2208 	    CLEAR_FIELD(local_evalarg);
2209 	    evalarg_used = &local_evalarg;
2210 	}
2211 	orig_flags = evalarg_used->eval_flags;
2212 	evaluate = evalarg_used->eval_flags & EVAL_EVALUATE;
2213 
2214 	if (getnext)
2215 	    *arg = eval_next_line(evalarg_used);
2216 	else
2217 	{
2218 	    if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2219 	    {
2220 		error_white_both(p, 1);
2221 		clear_tv(rettv);
2222 		return FAIL;
2223 	    }
2224 	    *arg = p;
2225 	}
2226 
2227 	result = FALSE;
2228 	if (evaluate)
2229 	{
2230 	    int		error = FALSE;
2231 
2232 	    if (op_falsy)
2233 		result = tv2bool(rettv);
2234 	    else if (vim9script)
2235 		result = tv_get_bool_chk(rettv, &error);
2236 	    else if (tv_get_number_chk(rettv, &error) != 0)
2237 		result = TRUE;
2238 	    if (error || !op_falsy || !result)
2239 		clear_tv(rettv);
2240 	    if (error)
2241 		return FAIL;
2242 	}
2243 
2244 	/*
2245 	 * Get the second variable.  Recursive!
2246 	 */
2247 	if (op_falsy)
2248 	    ++*arg;
2249 	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[1]))
2250 	{
2251 	    error_white_both(p, 1);
2252 	    clear_tv(rettv);
2253 	    return FAIL;
2254 	}
2255 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2256 	evalarg_used->eval_flags = (op_falsy ? !result : result)
2257 				    ? orig_flags : orig_flags & ~EVAL_EVALUATE;
2258 	if (eval1(arg, &var2, evalarg_used) == FAIL)
2259 	{
2260 	    evalarg_used->eval_flags = orig_flags;
2261 	    return FAIL;
2262 	}
2263 	if (!op_falsy || !result)
2264 	    *rettv = var2;
2265 
2266 	if (!op_falsy)
2267 	{
2268 	    /*
2269 	     * Check for the ":".
2270 	     */
2271 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2272 	    if (*p != ':')
2273 	    {
2274 		emsg(_(e_missing_colon));
2275 		if (evaluate && result)
2276 		    clear_tv(rettv);
2277 		evalarg_used->eval_flags = orig_flags;
2278 		return FAIL;
2279 	    }
2280 	    if (getnext)
2281 		*arg = eval_next_line(evalarg_used);
2282 	    else
2283 	    {
2284 		if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2285 		{
2286 		    error_white_both(p, 1);
2287 		    clear_tv(rettv);
2288 		    evalarg_used->eval_flags = orig_flags;
2289 		    return FAIL;
2290 		}
2291 		*arg = p;
2292 	    }
2293 
2294 	    /*
2295 	     * Get the third variable.  Recursive!
2296 	     */
2297 	    if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[1]))
2298 	    {
2299 		error_white_both(p, 1);
2300 		clear_tv(rettv);
2301 		evalarg_used->eval_flags = orig_flags;
2302 		return FAIL;
2303 	    }
2304 	    *arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2305 	    evalarg_used->eval_flags = !result ? orig_flags
2306 						 : orig_flags & ~EVAL_EVALUATE;
2307 	    if (eval1(arg, &var2, evalarg_used) == FAIL)
2308 	    {
2309 		if (evaluate && result)
2310 		    clear_tv(rettv);
2311 		evalarg_used->eval_flags = orig_flags;
2312 		return FAIL;
2313 	    }
2314 	    if (evaluate && !result)
2315 		*rettv = var2;
2316 	}
2317 
2318 	if (evalarg == NULL)
2319 	    clear_evalarg(&local_evalarg, NULL);
2320 	else
2321 	    evalarg->eval_flags = orig_flags;
2322     }
2323 
2324     return OK;
2325 }
2326 
2327 /*
2328  * Handle first level expression:
2329  *	expr2 || expr2 || expr2	    logical OR
2330  *
2331  * "arg" must point to the first non-white of the expression.
2332  * "arg" is advanced to just after the recognized expression.
2333  *
2334  * Return OK or FAIL.
2335  */
2336     static int
2337 eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2338 {
2339     char_u	*p;
2340     int		getnext;
2341 
2342     /*
2343      * Get the first variable.
2344      */
2345     if (eval3(arg, rettv, evalarg) == FAIL)
2346 	return FAIL;
2347 
2348     /*
2349      * Handle the  "||" operator.
2350      */
2351     p = eval_next_non_blank(*arg, evalarg, &getnext);
2352     if (p[0] == '|' && p[1] == '|')
2353     {
2354 	evalarg_T   *evalarg_used = evalarg;
2355 	evalarg_T   local_evalarg;
2356 	int	    evaluate;
2357 	int	    orig_flags;
2358 	long	    result = FALSE;
2359 	typval_T    var2;
2360 	int	    error = FALSE;
2361 	int	    vim9script = in_vim9script();
2362 
2363 	if (evalarg == NULL)
2364 	{
2365 	    CLEAR_FIELD(local_evalarg);
2366 	    evalarg_used = &local_evalarg;
2367 	}
2368 	orig_flags = evalarg_used->eval_flags;
2369 	evaluate = orig_flags & EVAL_EVALUATE;
2370 	if (evaluate)
2371 	{
2372 	    if (vim9script)
2373 		result = tv_get_bool_chk(rettv, &error);
2374 	    else if (tv_get_number_chk(rettv, &error) != 0)
2375 		result = TRUE;
2376 	    clear_tv(rettv);
2377 	    if (error)
2378 		return FAIL;
2379 	}
2380 
2381 	/*
2382 	 * Repeat until there is no following "||".
2383 	 */
2384 	while (p[0] == '|' && p[1] == '|')
2385 	{
2386 	    if (getnext)
2387 		*arg = eval_next_line(evalarg_used);
2388 	    else
2389 	    {
2390 		if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2391 		{
2392 		    error_white_both(p, 2);
2393 		    clear_tv(rettv);
2394 		    return FAIL;
2395 		}
2396 		*arg = p;
2397 	    }
2398 
2399 	    /*
2400 	     * Get the second variable.
2401 	     */
2402 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2403 	    {
2404 		error_white_both(p, 2);
2405 		clear_tv(rettv);
2406 		return FAIL;
2407 	    }
2408 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2409 	    evalarg_used->eval_flags = !result ? orig_flags
2410 						 : orig_flags & ~EVAL_EVALUATE;
2411 	    if (eval3(arg, &var2, evalarg_used) == FAIL)
2412 		return FAIL;
2413 
2414 	    /*
2415 	     * Compute the result.
2416 	     */
2417 	    if (evaluate && !result)
2418 	    {
2419 		if (vim9script)
2420 		    result = tv_get_bool_chk(&var2, &error);
2421 		else if (tv_get_number_chk(&var2, &error) != 0)
2422 		    result = TRUE;
2423 		clear_tv(&var2);
2424 		if (error)
2425 		    return FAIL;
2426 	    }
2427 	    if (evaluate)
2428 	    {
2429 		if (vim9script)
2430 		{
2431 		    rettv->v_type = VAR_BOOL;
2432 		    rettv->vval.v_number = result ? VVAL_TRUE : VVAL_FALSE;
2433 		}
2434 		else
2435 		{
2436 		    rettv->v_type = VAR_NUMBER;
2437 		    rettv->vval.v_number = result;
2438 		}
2439 	    }
2440 
2441 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2442 	}
2443 
2444 	if (evalarg == NULL)
2445 	    clear_evalarg(&local_evalarg, NULL);
2446 	else
2447 	    evalarg->eval_flags = orig_flags;
2448     }
2449 
2450     return OK;
2451 }
2452 
2453 /*
2454  * Handle second level expression:
2455  *	expr3 && expr3 && expr3	    logical AND
2456  *
2457  * "arg" must point to the first non-white of the expression.
2458  * "arg" is advanced to just after the recognized expression.
2459  *
2460  * Return OK or FAIL.
2461  */
2462     static int
2463 eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2464 {
2465     char_u	*p;
2466     int		getnext;
2467 
2468     /*
2469      * Get the first variable.
2470      */
2471     if (eval4(arg, rettv, evalarg) == FAIL)
2472 	return FAIL;
2473 
2474     /*
2475      * Handle the "&&" operator.
2476      */
2477     p = eval_next_non_blank(*arg, evalarg, &getnext);
2478     if (p[0] == '&' && p[1] == '&')
2479     {
2480 	evalarg_T   *evalarg_used = evalarg;
2481 	evalarg_T   local_evalarg;
2482 	int	    orig_flags;
2483 	int	    evaluate;
2484 	long	    result = TRUE;
2485 	typval_T    var2;
2486 	int	    error = FALSE;
2487 	int	    vim9script = in_vim9script();
2488 
2489 	if (evalarg == NULL)
2490 	{
2491 	    CLEAR_FIELD(local_evalarg);
2492 	    evalarg_used = &local_evalarg;
2493 	}
2494 	orig_flags = evalarg_used->eval_flags;
2495 	evaluate = orig_flags & EVAL_EVALUATE;
2496 	if (evaluate)
2497 	{
2498 	    if (vim9script)
2499 		result = tv_get_bool_chk(rettv, &error);
2500 	    else if (tv_get_number_chk(rettv, &error) == 0)
2501 		result = FALSE;
2502 	    clear_tv(rettv);
2503 	    if (error)
2504 		return FAIL;
2505 	}
2506 
2507 	/*
2508 	 * Repeat until there is no following "&&".
2509 	 */
2510 	while (p[0] == '&' && p[1] == '&')
2511 	{
2512 	    if (getnext)
2513 		*arg = eval_next_line(evalarg_used);
2514 	    else
2515 	    {
2516 		if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2517 		{
2518 		    error_white_both(p, 2);
2519 		    clear_tv(rettv);
2520 		    return FAIL;
2521 		}
2522 		*arg = p;
2523 	    }
2524 
2525 	    /*
2526 	     * Get the second variable.
2527 	     */
2528 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2529 	    {
2530 		error_white_both(p, 2);
2531 		clear_tv(rettv);
2532 		return FAIL;
2533 	    }
2534 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2535 	    evalarg_used->eval_flags = result ? orig_flags
2536 						 : orig_flags & ~EVAL_EVALUATE;
2537 	    CLEAR_FIELD(var2);
2538 	    if (eval4(arg, &var2, evalarg_used) == FAIL)
2539 		return FAIL;
2540 
2541 	    /*
2542 	     * Compute the result.
2543 	     */
2544 	    if (evaluate && result)
2545 	    {
2546 		if (vim9script)
2547 		    result = tv_get_bool_chk(&var2, &error);
2548 		else if (tv_get_number_chk(&var2, &error) == 0)
2549 		    result = FALSE;
2550 		clear_tv(&var2);
2551 		if (error)
2552 		    return FAIL;
2553 	    }
2554 	    if (evaluate)
2555 	    {
2556 		if (vim9script)
2557 		{
2558 		    rettv->v_type = VAR_BOOL;
2559 		    rettv->vval.v_number = result ? VVAL_TRUE : VVAL_FALSE;
2560 		}
2561 		else
2562 		{
2563 		    rettv->v_type = VAR_NUMBER;
2564 		    rettv->vval.v_number = result;
2565 		}
2566 	    }
2567 
2568 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2569 	}
2570 
2571 	if (evalarg == NULL)
2572 	    clear_evalarg(&local_evalarg, NULL);
2573 	else
2574 	    evalarg->eval_flags = orig_flags;
2575     }
2576 
2577     return OK;
2578 }
2579 
2580 /*
2581  * Handle third level expression:
2582  *	var1 == var2
2583  *	var1 =~ var2
2584  *	var1 != var2
2585  *	var1 !~ var2
2586  *	var1 > var2
2587  *	var1 >= var2
2588  *	var1 < var2
2589  *	var1 <= var2
2590  *	var1 is var2
2591  *	var1 isnot var2
2592  *
2593  * "arg" must point to the first non-white of the expression.
2594  * "arg" is advanced to just after the recognized expression.
2595  *
2596  * Return OK or FAIL.
2597  */
2598     static int
2599 eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2600 {
2601     char_u	*p;
2602     int		getnext;
2603     exptype_T	type = EXPR_UNKNOWN;
2604     int		len = 2;
2605     int		type_is = FALSE;
2606 
2607     /*
2608      * Get the first variable.
2609      */
2610     if (eval5(arg, rettv, evalarg) == FAIL)
2611 	return FAIL;
2612 
2613     p = eval_next_non_blank(*arg, evalarg, &getnext);
2614     type = get_compare_type(p, &len, &type_is);
2615 
2616     /*
2617      * If there is a comparative operator, use it.
2618      */
2619     if (type != EXPR_UNKNOWN)
2620     {
2621 	typval_T    var2;
2622 	int	    ic;
2623 	int	    vim9script = in_vim9script();
2624 	int	    evaluate = evalarg == NULL
2625 				   ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2626 
2627 	if (getnext)
2628 	    *arg = eval_next_line(evalarg);
2629 	else if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2630 	{
2631 	    error_white_both(p, len);
2632 	    clear_tv(rettv);
2633 	    return FAIL;
2634 	}
2635 
2636 	if (vim9script && type_is && (p[len] == '?' || p[len] == '#'))
2637 	{
2638 	    semsg(_(e_invexpr2), p);
2639 	    clear_tv(rettv);
2640 	    return FAIL;
2641 	}
2642 
2643 	// extra question mark appended: ignore case
2644 	if (p[len] == '?')
2645 	{
2646 	    ic = TRUE;
2647 	    ++len;
2648 	}
2649 	// extra '#' appended: match case
2650 	else if (p[len] == '#')
2651 	{
2652 	    ic = FALSE;
2653 	    ++len;
2654 	}
2655 	// nothing appended: use 'ignorecase' if not in Vim script
2656 	else
2657 	    ic = vim9script ? FALSE : p_ic;
2658 
2659 	/*
2660 	 * Get the second variable.
2661 	 */
2662 	if (evaluate && vim9script && !IS_WHITE_OR_NUL(p[len]))
2663 	{
2664 	    error_white_both(p, 1);
2665 	    clear_tv(rettv);
2666 	    return FAIL;
2667 	}
2668 	*arg = skipwhite_and_linebreak(p + len, evalarg);
2669 	if (eval5(arg, &var2, evalarg) == FAIL)
2670 	{
2671 	    clear_tv(rettv);
2672 	    return FAIL;
2673 	}
2674 	if (evaluate)
2675 	{
2676 	    int ret;
2677 
2678 	    if (vim9script && check_compare_types(type, rettv, &var2) == FAIL)
2679 	    {
2680 		ret = FAIL;
2681 		clear_tv(rettv);
2682 	    }
2683 	    else
2684 		ret = typval_compare(rettv, &var2, type, ic);
2685 	    clear_tv(&var2);
2686 	    return ret;
2687 	}
2688     }
2689 
2690     return OK;
2691 }
2692 
2693 /*
2694  * Make a copy of blob "tv1" and append blob "tv2".
2695  */
2696     void
2697 eval_addblob(typval_T *tv1, typval_T *tv2)
2698 {
2699     blob_T  *b1 = tv1->vval.v_blob;
2700     blob_T  *b2 = tv2->vval.v_blob;
2701     blob_T  *b = blob_alloc();
2702     int	    i;
2703 
2704     if (b != NULL)
2705     {
2706 	for (i = 0; i < blob_len(b1); i++)
2707 	    ga_append(&b->bv_ga, blob_get(b1, i));
2708 	for (i = 0; i < blob_len(b2); i++)
2709 	    ga_append(&b->bv_ga, blob_get(b2, i));
2710 
2711 	clear_tv(tv1);
2712 	rettv_blob_set(tv1, b);
2713     }
2714 }
2715 
2716 /*
2717  * Make a copy of list "tv1" and append list "tv2".
2718  */
2719     int
2720 eval_addlist(typval_T *tv1, typval_T *tv2)
2721 {
2722     typval_T var3;
2723 
2724     // concatenate Lists
2725     if (list_concat(tv1->vval.v_list, tv2->vval.v_list, &var3) == FAIL)
2726     {
2727 	clear_tv(tv1);
2728 	clear_tv(tv2);
2729 	return FAIL;
2730     }
2731     clear_tv(tv1);
2732     *tv1 = var3;
2733     return OK;
2734 }
2735 
2736 /*
2737  * Handle fourth level expression:
2738  *	+	number addition
2739  *	-	number subtraction
2740  *	.	string concatenation (if script version is 1)
2741  *	..	string concatenation
2742  *
2743  * "arg" must point to the first non-white of the expression.
2744  * "arg" is advanced to just after the recognized expression.
2745  *
2746  * Return OK or FAIL.
2747  */
2748     static int
2749 eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2750 {
2751     /*
2752      * Get the first variable.
2753      */
2754     if (eval6(arg, rettv, evalarg, FALSE) == FAIL)
2755 	return FAIL;
2756 
2757     /*
2758      * Repeat computing, until no '+', '-' or '.' is following.
2759      */
2760     for (;;)
2761     {
2762 	int	    evaluate;
2763 	int	    getnext;
2764 	char_u	    *p;
2765 	int	    op;
2766 	int	    oplen;
2767 	int	    concat;
2768 	typval_T    var2;
2769 	int	    vim9script = in_vim9script();
2770 
2771 	// "." is only string concatenation when scriptversion is 1
2772 	// "+=" and "-=" are assignment
2773 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2774 	op = *p;
2775 	concat = op == '.' && (*(p + 1) == '.' || current_sctx.sc_version < 2);
2776 	if ((op != '+' && op != '-' && !concat) || p[1] == '=')
2777 	    break;
2778 
2779 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2780 	oplen = (concat && p[1] == '.') ? 2 : 1;
2781 	if (getnext)
2782 	    *arg = eval_next_line(evalarg);
2783 	else
2784 	{
2785 	    if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2786 	    {
2787 		error_white_both(p, oplen);
2788 		clear_tv(rettv);
2789 		return FAIL;
2790 	    }
2791 	    *arg = p;
2792 	}
2793 	if ((op != '+' || (rettv->v_type != VAR_LIST
2794 						 && rettv->v_type != VAR_BLOB))
2795 #ifdef FEAT_FLOAT
2796 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2797 #endif
2798 		&& evaluate)
2799 	{
2800 	    int		error = FALSE;
2801 
2802 	    // For "list + ...", an illegal use of the first operand as
2803 	    // a number cannot be determined before evaluating the 2nd
2804 	    // operand: if this is also a list, all is ok.
2805 	    // For "something . ...", "something - ..." or "non-list + ...",
2806 	    // we know that the first operand needs to be a string or number
2807 	    // without evaluating the 2nd operand.  So check before to avoid
2808 	    // side effects after an error.
2809 	    if (op != '.')
2810 		tv_get_number_chk(rettv, &error);
2811 	    if ((op == '.' && tv_get_string_chk(rettv) == NULL) || error)
2812 	    {
2813 		clear_tv(rettv);
2814 		return FAIL;
2815 	    }
2816 	}
2817 
2818 	/*
2819 	 * Get the second variable.
2820 	 */
2821 	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[oplen]))
2822 	{
2823 	    error_white_both(p, oplen);
2824 	    clear_tv(rettv);
2825 	    return FAIL;
2826 	}
2827 	*arg = skipwhite_and_linebreak(*arg + oplen, evalarg);
2828 	if (eval6(arg, &var2, evalarg, !vim9script && op == '.') == FAIL)
2829 	{
2830 	    clear_tv(rettv);
2831 	    return FAIL;
2832 	}
2833 
2834 	if (evaluate)
2835 	{
2836 	    /*
2837 	     * Compute the result.
2838 	     */
2839 	    if (op == '.')
2840 	    {
2841 		char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
2842 		char_u	*s1 = tv_get_string_buf(rettv, buf1);
2843 		char_u	*s2 = NULL;
2844 
2845 		if (vim9script && (var2.v_type == VAR_VOID
2846 			|| var2.v_type == VAR_CHANNEL
2847 			|| var2.v_type == VAR_JOB))
2848 		    emsg(_(e_inval_string));
2849 #ifdef FEAT_FLOAT
2850 		else if (vim9script && var2.v_type == VAR_FLOAT)
2851 		{
2852 		    vim_snprintf((char *)buf2, NUMBUFLEN, "%g",
2853 							    var2.vval.v_float);
2854 		    s2 = buf2;
2855 		}
2856 #endif
2857 		else
2858 		    s2 = tv_get_string_buf_chk(&var2, buf2);
2859 		if (s2 == NULL)		// type error ?
2860 		{
2861 		    clear_tv(rettv);
2862 		    clear_tv(&var2);
2863 		    return FAIL;
2864 		}
2865 		p = concat_str(s1, s2);
2866 		clear_tv(rettv);
2867 		rettv->v_type = VAR_STRING;
2868 		rettv->vval.v_string = p;
2869 	    }
2870 	    else if (op == '+' && rettv->v_type == VAR_BLOB
2871 						   && var2.v_type == VAR_BLOB)
2872 		eval_addblob(rettv, &var2);
2873 	    else if (op == '+' && rettv->v_type == VAR_LIST
2874 						   && var2.v_type == VAR_LIST)
2875 	    {
2876 		if (eval_addlist(rettv, &var2) == FAIL)
2877 		    return FAIL;
2878 	    }
2879 	    else
2880 	    {
2881 		int		error = FALSE;
2882 		varnumber_T	n1, n2;
2883 #ifdef FEAT_FLOAT
2884 		float_T	    f1 = 0, f2 = 0;
2885 
2886 		if (rettv->v_type == VAR_FLOAT)
2887 		{
2888 		    f1 = rettv->vval.v_float;
2889 		    n1 = 0;
2890 		}
2891 		else
2892 #endif
2893 		{
2894 		    n1 = tv_get_number_chk(rettv, &error);
2895 		    if (error)
2896 		    {
2897 			// This can only happen for "list + non-list".  For
2898 			// "non-list + ..." or "something - ...", we returned
2899 			// before evaluating the 2nd operand.
2900 			clear_tv(rettv);
2901 			return FAIL;
2902 		    }
2903 #ifdef FEAT_FLOAT
2904 		    if (var2.v_type == VAR_FLOAT)
2905 			f1 = n1;
2906 #endif
2907 		}
2908 #ifdef FEAT_FLOAT
2909 		if (var2.v_type == VAR_FLOAT)
2910 		{
2911 		    f2 = var2.vval.v_float;
2912 		    n2 = 0;
2913 		}
2914 		else
2915 #endif
2916 		{
2917 		    n2 = tv_get_number_chk(&var2, &error);
2918 		    if (error)
2919 		    {
2920 			clear_tv(rettv);
2921 			clear_tv(&var2);
2922 			return FAIL;
2923 		    }
2924 #ifdef FEAT_FLOAT
2925 		    if (rettv->v_type == VAR_FLOAT)
2926 			f2 = n2;
2927 #endif
2928 		}
2929 		clear_tv(rettv);
2930 
2931 #ifdef FEAT_FLOAT
2932 		// If there is a float on either side the result is a float.
2933 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
2934 		{
2935 		    if (op == '+')
2936 			f1 = f1 + f2;
2937 		    else
2938 			f1 = f1 - f2;
2939 		    rettv->v_type = VAR_FLOAT;
2940 		    rettv->vval.v_float = f1;
2941 		}
2942 		else
2943 #endif
2944 		{
2945 		    if (op == '+')
2946 			n1 = n1 + n2;
2947 		    else
2948 			n1 = n1 - n2;
2949 		    rettv->v_type = VAR_NUMBER;
2950 		    rettv->vval.v_number = n1;
2951 		}
2952 	    }
2953 	    clear_tv(&var2);
2954 	}
2955     }
2956     return OK;
2957 }
2958 
2959 /*
2960  * Handle fifth level expression:
2961  *	*	number multiplication
2962  *	/	number division
2963  *	%	number modulo
2964  *
2965  * "arg" must point to the first non-white of the expression.
2966  * "arg" is advanced to just after the recognized expression.
2967  *
2968  * Return OK or FAIL.
2969  */
2970     static int
2971 eval6(
2972     char_u	**arg,
2973     typval_T	*rettv,
2974     evalarg_T	*evalarg,
2975     int		want_string)  // after "." operator
2976 {
2977 #ifdef FEAT_FLOAT
2978     int	    use_float = FALSE;
2979 #endif
2980 
2981     /*
2982      * Get the first variable.
2983      */
2984     if (eval7(arg, rettv, evalarg, want_string) == FAIL)
2985 	return FAIL;
2986 
2987     /*
2988      * Repeat computing, until no '*', '/' or '%' is following.
2989      */
2990     for (;;)
2991     {
2992 	int	    evaluate;
2993 	int	    getnext;
2994 	typval_T    var2;
2995 	char_u	    *p;
2996 	int	    op;
2997 	varnumber_T n1, n2;
2998 #ifdef FEAT_FLOAT
2999 	float_T	    f1, f2;
3000 #endif
3001 	int	    error;
3002 
3003 	p = eval_next_non_blank(*arg, evalarg, &getnext);
3004 	op = *p;
3005 	if (op != '*' && op != '/' && op != '%')
3006 	    break;
3007 
3008 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
3009 	if (getnext)
3010 	    *arg = eval_next_line(evalarg);
3011 	else
3012 	{
3013 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(**arg))
3014 	    {
3015 		error_white_both(p, 1);
3016 		clear_tv(rettv);
3017 		return FAIL;
3018 	    }
3019 	    *arg = p;
3020 	}
3021 
3022 #ifdef FEAT_FLOAT
3023 	f1 = 0;
3024 	f2 = 0;
3025 #endif
3026 	error = FALSE;
3027 	if (evaluate)
3028 	{
3029 #ifdef FEAT_FLOAT
3030 	    if (rettv->v_type == VAR_FLOAT)
3031 	    {
3032 		f1 = rettv->vval.v_float;
3033 		use_float = TRUE;
3034 		n1 = 0;
3035 	    }
3036 	    else
3037 #endif
3038 		n1 = tv_get_number_chk(rettv, &error);
3039 	    clear_tv(rettv);
3040 	    if (error)
3041 		return FAIL;
3042 	}
3043 	else
3044 	    n1 = 0;
3045 
3046 	/*
3047 	 * Get the second variable.
3048 	 */
3049 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[1]))
3050 	{
3051 	    error_white_both(p, 1);
3052 	    clear_tv(rettv);
3053 	    return FAIL;
3054 	}
3055 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3056 	if (eval7(arg, &var2, evalarg, FALSE) == FAIL)
3057 	    return FAIL;
3058 
3059 	if (evaluate)
3060 	{
3061 #ifdef FEAT_FLOAT
3062 	    if (var2.v_type == VAR_FLOAT)
3063 	    {
3064 		if (!use_float)
3065 		{
3066 		    f1 = n1;
3067 		    use_float = TRUE;
3068 		}
3069 		f2 = var2.vval.v_float;
3070 		n2 = 0;
3071 	    }
3072 	    else
3073 #endif
3074 	    {
3075 		n2 = tv_get_number_chk(&var2, &error);
3076 		clear_tv(&var2);
3077 		if (error)
3078 		    return FAIL;
3079 #ifdef FEAT_FLOAT
3080 		if (use_float)
3081 		    f2 = n2;
3082 #endif
3083 	    }
3084 
3085 	    /*
3086 	     * Compute the result.
3087 	     * When either side is a float the result is a float.
3088 	     */
3089 #ifdef FEAT_FLOAT
3090 	    if (use_float)
3091 	    {
3092 		if (op == '*')
3093 		    f1 = f1 * f2;
3094 		else if (op == '/')
3095 		{
3096 # ifdef VMS
3097 		    // VMS crashes on divide by zero, work around it
3098 		    if (f2 == 0.0)
3099 		    {
3100 			if (f1 == 0)
3101 			    f1 = -1 * __F_FLT_MAX - 1L;   // similar to NaN
3102 			else if (f1 < 0)
3103 			    f1 = -1 * __F_FLT_MAX;
3104 			else
3105 			    f1 = __F_FLT_MAX;
3106 		    }
3107 		    else
3108 			f1 = f1 / f2;
3109 # else
3110 		    // We rely on the floating point library to handle divide
3111 		    // by zero to result in "inf" and not a crash.
3112 		    f1 = f1 / f2;
3113 # endif
3114 		}
3115 		else
3116 		{
3117 		    emsg(_(e_modulus));
3118 		    return FAIL;
3119 		}
3120 		rettv->v_type = VAR_FLOAT;
3121 		rettv->vval.v_float = f1;
3122 	    }
3123 	    else
3124 #endif
3125 	    {
3126 		if (op == '*')
3127 		    n1 = n1 * n2;
3128 		else if (op == '/')
3129 		    n1 = num_divide(n1, n2);
3130 		else
3131 		    n1 = num_modulus(n1, n2);
3132 
3133 		rettv->v_type = VAR_NUMBER;
3134 		rettv->vval.v_number = n1;
3135 	    }
3136 	}
3137     }
3138 
3139     return OK;
3140 }
3141 
3142 /*
3143  * Handle sixth level expression:
3144  *  number		number constant
3145  *  0zFFFFFFFF		Blob constant
3146  *  "string"		string constant
3147  *  'string'		literal string constant
3148  *  &option-name	option value
3149  *  @r			register contents
3150  *  identifier		variable value
3151  *  function()		function call
3152  *  $VAR		environment variable
3153  *  (expression)	nested expression
3154  *  [expr, expr]	List
3155  *  {arg, arg -> expr}	Lambda
3156  *  {key: val, key: val}   Dictionary
3157  *  #{key: val, key: val}  Dictionary with literal keys
3158  *
3159  *  Also handle:
3160  *  ! in front		logical NOT
3161  *  - in front		unary minus
3162  *  + in front		unary plus (ignored)
3163  *  trailing []		subscript in String or List
3164  *  trailing .name	entry in Dictionary
3165  *  trailing ->name()	method call
3166  *
3167  * "arg" must point to the first non-white of the expression.
3168  * "arg" is advanced to just after the recognized expression.
3169  *
3170  * Return OK or FAIL.
3171  */
3172     static int
3173 eval7(
3174     char_u	**arg,
3175     typval_T	*rettv,
3176     evalarg_T	*evalarg,
3177     int		want_string)	// after "." operator
3178 {
3179     int		evaluate = evalarg != NULL
3180 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3181     int		len;
3182     char_u	*s;
3183     char_u	*start_leader, *end_leader;
3184     int		ret = OK;
3185     char_u	*alias;
3186 
3187     /*
3188      * Initialise variable so that clear_tv() can't mistake this for a
3189      * string and free a string that isn't there.
3190      */
3191     rettv->v_type = VAR_UNKNOWN;
3192 
3193     /*
3194      * Skip '!', '-' and '+' characters.  They are handled later.
3195      */
3196     start_leader = *arg;
3197     while (**arg == '!' || **arg == '-' || **arg == '+')
3198 	*arg = skipwhite(*arg + 1);
3199     end_leader = *arg;
3200 
3201     if (**arg == '.' && (!isdigit(*(*arg + 1))
3202 #ifdef FEAT_FLOAT
3203 	    || current_sctx.sc_version < 2
3204 #endif
3205 	    ))
3206     {
3207 	semsg(_(e_invexpr2), *arg);
3208 	++*arg;
3209 	return FAIL;
3210     }
3211 
3212     switch (**arg)
3213     {
3214     /*
3215      * Number constant.
3216      */
3217     case '0':
3218     case '1':
3219     case '2':
3220     case '3':
3221     case '4':
3222     case '5':
3223     case '6':
3224     case '7':
3225     case '8':
3226     case '9':
3227     case '.':	ret = eval_number(arg, rettv, evaluate, want_string);
3228 
3229 		// Apply prefixed "-" and "+" now.  Matters especially when
3230 		// "->" follows.
3231 		if (ret == OK && evaluate && end_leader > start_leader
3232 						  && rettv->v_type != VAR_BLOB)
3233 		    ret = eval7_leader(rettv, TRUE, start_leader, &end_leader);
3234 		break;
3235 
3236     /*
3237      * String constant: "string".
3238      */
3239     case '"':	ret = eval_string(arg, rettv, evaluate);
3240 		break;
3241 
3242     /*
3243      * Literal string constant: 'str''ing'.
3244      */
3245     case '\'':	ret = eval_lit_string(arg, rettv, evaluate);
3246 		break;
3247 
3248     /*
3249      * List: [expr, expr]
3250      */
3251     case '[':	ret = eval_list(arg, rettv, evalarg, TRUE);
3252 		break;
3253 
3254     /*
3255      * Dictionary: #{key: val, key: val}
3256      */
3257     case '#':	if ((*arg)[1] == '{')
3258 		{
3259 		    ++*arg;
3260 		    ret = eval_dict(arg, rettv, evalarg, TRUE);
3261 		}
3262 		else
3263 		    ret = NOTDONE;
3264 		break;
3265 
3266     /*
3267      * Lambda: {arg, arg -> expr}
3268      * Dictionary: {'key': val, 'key': val}
3269      */
3270     case '{':	ret = get_lambda_tv(arg, rettv, in_vim9script(), evalarg);
3271 		if (ret == NOTDONE)
3272 		    ret = eval_dict(arg, rettv, evalarg, FALSE);
3273 		break;
3274 
3275     /*
3276      * Option value: &name
3277      */
3278     case '&':	ret = eval_option(arg, rettv, evaluate);
3279 		break;
3280 
3281     /*
3282      * Environment variable: $VAR.
3283      */
3284     case '$':	ret = eval_env_var(arg, rettv, evaluate);
3285 		break;
3286 
3287     /*
3288      * Register contents: @r.
3289      */
3290     case '@':	++*arg;
3291 		if (evaluate)
3292 		{
3293 		    rettv->v_type = VAR_STRING;
3294 		    rettv->vval.v_string = get_reg_contents(**arg,
3295 							    GREG_EXPR_SRC);
3296 		}
3297 		if (**arg != NUL)
3298 		    ++*arg;
3299 		break;
3300 
3301     /*
3302      * nested expression: (expression).
3303      */
3304     case '(':	{
3305 		    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3306 		    ret = eval1(arg, rettv, evalarg);	// recursive!
3307 
3308 		    *arg = skipwhite_and_linebreak(*arg, evalarg);
3309 		    if (**arg == ')')
3310 			++*arg;
3311 		    else if (ret == OK)
3312 		    {
3313 			emsg(_(e_missing_close));
3314 			clear_tv(rettv);
3315 			ret = FAIL;
3316 		    }
3317 		}
3318 		break;
3319 
3320     default:	ret = NOTDONE;
3321 		break;
3322     }
3323 
3324     if (ret == NOTDONE)
3325     {
3326 	/*
3327 	 * Must be a variable or function name.
3328 	 * Can also be a curly-braces kind of name: {expr}.
3329 	 */
3330 	s = *arg;
3331 	len = get_name_len(arg, &alias, evaluate, TRUE);
3332 	if (alias != NULL)
3333 	    s = alias;
3334 
3335 	if (len <= 0)
3336 	    ret = FAIL;
3337 	else
3338 	{
3339 	    int	    flags = evalarg == NULL ? 0 : evalarg->eval_flags;
3340 
3341 	    if ((in_vim9script() ? **arg : *skipwhite(*arg)) == '(')
3342 	    {
3343 		// "name(..."  recursive!
3344 		*arg = skipwhite(*arg);
3345 		ret = eval_func(arg, evalarg, s, len, rettv, flags, NULL);
3346 	    }
3347 	    else if (flags & EVAL_CONSTANT)
3348 		ret = FAIL;
3349 	    else if (evaluate)
3350 	    {
3351 		// get the value of "true", "false" or a variable
3352 		if (len == 4 && in_vim9script() && STRNCMP(s, "true", 4) == 0)
3353 		{
3354 		    rettv->v_type = VAR_BOOL;
3355 		    rettv->vval.v_number = VVAL_TRUE;
3356 		    ret = OK;
3357 		}
3358 		else if (len == 5 && in_vim9script()
3359 						&& STRNCMP(s, "false", 4) == 0)
3360 		{
3361 		    rettv->v_type = VAR_BOOL;
3362 		    rettv->vval.v_number = VVAL_FALSE;
3363 		    ret = OK;
3364 		}
3365 		else
3366 		    ret = eval_variable(s, len, rettv, NULL, TRUE, FALSE);
3367 	    }
3368 	    else
3369 	    {
3370 		// skip the name
3371 		check_vars(s, len);
3372 		ret = OK;
3373 	    }
3374 	}
3375 	vim_free(alias);
3376     }
3377 
3378     // Handle following '[', '(' and '.' for expr[expr], expr.name,
3379     // expr(expr), expr->name(expr)
3380     if (ret == OK)
3381 	ret = handle_subscript(arg, rettv, evalarg, TRUE);
3382 
3383     /*
3384      * Apply logical NOT and unary '-', from right to left, ignore '+'.
3385      */
3386     if (ret == OK && evaluate && end_leader > start_leader)
3387 	ret = eval7_leader(rettv, FALSE, start_leader, &end_leader);
3388     return ret;
3389 }
3390 
3391 /*
3392  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
3393  * When "numeric_only" is TRUE only handle "+" and "-".
3394  * Adjusts "end_leaderp" until it is at "start_leader".
3395  */
3396     static int
3397 eval7_leader(
3398 	typval_T    *rettv,
3399 	int	    numeric_only,
3400 	char_u	    *start_leader,
3401 	char_u	    **end_leaderp)
3402 {
3403     char_u	*end_leader = *end_leaderp;
3404     int		ret = OK;
3405     int		error = FALSE;
3406     varnumber_T val = 0;
3407     vartype_T	type = rettv->v_type;
3408 #ifdef FEAT_FLOAT
3409     float_T	    f = 0.0;
3410 
3411     if (rettv->v_type == VAR_FLOAT)
3412 	f = rettv->vval.v_float;
3413     else
3414 #endif
3415     {
3416 	while (VIM_ISWHITE(end_leader[-1]))
3417 	    --end_leader;
3418 	if (in_vim9script() && end_leader[-1] == '!')
3419 	    val = tv2bool(rettv);
3420 	else
3421 	    val = tv_get_number_chk(rettv, &error);
3422     }
3423     if (error)
3424     {
3425 	clear_tv(rettv);
3426 	ret = FAIL;
3427     }
3428     else
3429     {
3430 	while (end_leader > start_leader)
3431 	{
3432 	    --end_leader;
3433 	    if (*end_leader == '!')
3434 	    {
3435 		if (numeric_only)
3436 		{
3437 		    ++end_leader;
3438 		    break;
3439 		}
3440 #ifdef FEAT_FLOAT
3441 		if (rettv->v_type == VAR_FLOAT)
3442 		{
3443 		    if (in_vim9script())
3444 		    {
3445 			rettv->v_type = VAR_BOOL;
3446 			val = f == 0.0 ? VVAL_TRUE : VVAL_FALSE;
3447 		    }
3448 		    else
3449 			f = !f;
3450 		}
3451 		else
3452 #endif
3453 		{
3454 		    val = !val;
3455 		    type = VAR_BOOL;
3456 		}
3457 	    }
3458 	    else if (*end_leader == '-')
3459 	    {
3460 #ifdef FEAT_FLOAT
3461 		if (rettv->v_type == VAR_FLOAT)
3462 		    f = -f;
3463 		else
3464 #endif
3465 		{
3466 		    val = -val;
3467 		    type = VAR_NUMBER;
3468 		}
3469 	    }
3470 	}
3471 #ifdef FEAT_FLOAT
3472 	if (rettv->v_type == VAR_FLOAT)
3473 	{
3474 	    clear_tv(rettv);
3475 	    rettv->vval.v_float = f;
3476 	}
3477 	else
3478 #endif
3479 	{
3480 	    clear_tv(rettv);
3481 	    if (in_vim9script())
3482 		rettv->v_type = type;
3483 	    else
3484 		rettv->v_type = VAR_NUMBER;
3485 	    rettv->vval.v_number = val;
3486 	}
3487     }
3488     *end_leaderp = end_leader;
3489     return ret;
3490 }
3491 
3492 /*
3493  * Call the function referred to in "rettv".
3494  */
3495     static int
3496 call_func_rettv(
3497 	char_u	    **arg,
3498 	evalarg_T   *evalarg,
3499 	typval_T    *rettv,
3500 	int	    evaluate,
3501 	dict_T	    *selfdict,
3502 	typval_T    *basetv)
3503 {
3504     partial_T	*pt = NULL;
3505     funcexe_T	funcexe;
3506     typval_T	functv;
3507     char_u	*s;
3508     int		ret;
3509 
3510     // need to copy the funcref so that we can clear rettv
3511     if (evaluate)
3512     {
3513 	functv = *rettv;
3514 	rettv->v_type = VAR_UNKNOWN;
3515 
3516 	// Invoke the function.  Recursive!
3517 	if (functv.v_type == VAR_PARTIAL)
3518 	{
3519 	    pt = functv.vval.v_partial;
3520 	    s = partial_name(pt);
3521 	}
3522 	else
3523 	    s = functv.vval.v_string;
3524     }
3525     else
3526 	s = (char_u *)"";
3527 
3528     CLEAR_FIELD(funcexe);
3529     funcexe.firstline = curwin->w_cursor.lnum;
3530     funcexe.lastline = curwin->w_cursor.lnum;
3531     funcexe.evaluate = evaluate;
3532     funcexe.partial = pt;
3533     funcexe.selfdict = selfdict;
3534     funcexe.basetv = basetv;
3535     ret = get_func_tv(s, -1, rettv, arg, evalarg, &funcexe);
3536 
3537     // Clear the funcref afterwards, so that deleting it while
3538     // evaluating the arguments is possible (see test55).
3539     if (evaluate)
3540 	clear_tv(&functv);
3541 
3542     return ret;
3543 }
3544 
3545 /*
3546  * Evaluate "->method()".
3547  * "*arg" points to the '-'.
3548  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3549  */
3550     static int
3551 eval_lambda(
3552     char_u	**arg,
3553     typval_T	*rettv,
3554     evalarg_T	*evalarg,
3555     int		verbose)	// give error messages
3556 {
3557     int		evaluate = evalarg != NULL
3558 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3559     typval_T	base = *rettv;
3560     int		ret;
3561 
3562     // Skip over the ->.
3563     *arg += 2;
3564     rettv->v_type = VAR_UNKNOWN;
3565 
3566     ret = get_lambda_tv(arg, rettv, FALSE, evalarg);
3567     if (ret != OK)
3568 	return FAIL;
3569     else if (**arg != '(')
3570     {
3571 	if (verbose)
3572 	{
3573 	    if (*skipwhite(*arg) == '(')
3574 		emsg(_(e_nowhitespace));
3575 	    else
3576 		semsg(_(e_missing_paren), "lambda");
3577 	}
3578 	clear_tv(rettv);
3579 	ret = FAIL;
3580     }
3581     else
3582 	ret = call_func_rettv(arg, evalarg, rettv, evaluate, NULL, &base);
3583 
3584     // Clear the funcref afterwards, so that deleting it while
3585     // evaluating the arguments is possible (see test55).
3586     if (evaluate)
3587 	clear_tv(&base);
3588 
3589     return ret;
3590 }
3591 
3592 /*
3593  * Evaluate "->method()".
3594  * "*arg" points to the '-'.
3595  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3596  */
3597     static int
3598 eval_method(
3599     char_u	**arg,
3600     typval_T	*rettv,
3601     evalarg_T	*evalarg,
3602     int		verbose)	// give error messages
3603 {
3604     char_u	*name;
3605     long	len;
3606     char_u	*alias;
3607     typval_T	base = *rettv;
3608     int		ret;
3609     int		evaluate = evalarg != NULL
3610 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3611 
3612     // Skip over the ->.
3613     *arg += 2;
3614     rettv->v_type = VAR_UNKNOWN;
3615 
3616     name = *arg;
3617     len = get_name_len(arg, &alias, evaluate, TRUE);
3618     if (alias != NULL)
3619 	name = alias;
3620 
3621     if (len <= 0)
3622     {
3623 	if (verbose)
3624 	    emsg(_("E260: Missing name after ->"));
3625 	ret = FAIL;
3626     }
3627     else
3628     {
3629 	*arg = skipwhite(*arg);
3630 	if (**arg != '(')
3631 	{
3632 	    if (verbose)
3633 		semsg(_(e_missing_paren), name);
3634 	    ret = FAIL;
3635 	}
3636 	else if (VIM_ISWHITE((*arg)[-1]))
3637 	{
3638 	    if (verbose)
3639 		emsg(_(e_nowhitespace));
3640 	    ret = FAIL;
3641 	}
3642 	else
3643 	    ret = eval_func(arg, evalarg, name, len, rettv,
3644 					  evaluate ? EVAL_EVALUATE : 0, &base);
3645     }
3646 
3647     // Clear the funcref afterwards, so that deleting it while
3648     // evaluating the arguments is possible (see test55).
3649     if (evaluate)
3650 	clear_tv(&base);
3651 
3652     return ret;
3653 }
3654 
3655 /*
3656  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
3657  * "*arg" points to the '[' or '.'.
3658  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
3659  */
3660     static int
3661 eval_index(
3662     char_u	**arg,
3663     typval_T	*rettv,
3664     evalarg_T	*evalarg,
3665     int		verbose)	// give error messages
3666 {
3667     int		evaluate = evalarg != NULL
3668 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3669     int		empty1 = FALSE, empty2 = FALSE;
3670     typval_T	var1, var2;
3671     int		range = FALSE;
3672     char_u	*key = NULL;
3673     int		keylen = -1;
3674 
3675     if (check_can_index(rettv, evaluate, verbose) == FAIL)
3676 	return FAIL;
3677 
3678     init_tv(&var1);
3679     init_tv(&var2);
3680     if (**arg == '.')
3681     {
3682 	/*
3683 	 * dict.name
3684 	 */
3685 	key = *arg + 1;
3686 	for (keylen = 0; eval_isdictc(key[keylen]); ++keylen)
3687 	    ;
3688 	if (keylen == 0)
3689 	    return FAIL;
3690 	*arg = key + keylen;
3691     }
3692     else
3693     {
3694 	/*
3695 	 * something[idx]
3696 	 *
3697 	 * Get the (first) variable from inside the [].
3698 	 */
3699 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3700 	if (**arg == ':')
3701 	    empty1 = TRUE;
3702 	else if (eval1(arg, &var1, evalarg) == FAIL)	// recursive!
3703 	    return FAIL;
3704 	else if (evaluate && tv_get_string_chk(&var1) == NULL)
3705 	{
3706 	    // not a number or string
3707 	    clear_tv(&var1);
3708 	    return FAIL;
3709 	}
3710 
3711 	/*
3712 	 * Get the second variable from inside the [:].
3713 	 */
3714 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3715 	if (**arg == ':')
3716 	{
3717 	    range = TRUE;
3718 	    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3719 	    if (**arg == ']')
3720 		empty2 = TRUE;
3721 	    else if (eval1(arg, &var2, evalarg) == FAIL)	// recursive!
3722 	    {
3723 		if (!empty1)
3724 		    clear_tv(&var1);
3725 		return FAIL;
3726 	    }
3727 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
3728 	    {
3729 		// not a number or string
3730 		if (!empty1)
3731 		    clear_tv(&var1);
3732 		clear_tv(&var2);
3733 		return FAIL;
3734 	    }
3735 	}
3736 
3737 	// Check for the ']'.
3738 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3739 	if (**arg != ']')
3740 	{
3741 	    if (verbose)
3742 		emsg(_(e_missbrac));
3743 	    clear_tv(&var1);
3744 	    if (range)
3745 		clear_tv(&var2);
3746 	    return FAIL;
3747 	}
3748 	*arg = *arg + 1;	// skip over the ']'
3749     }
3750 
3751     if (evaluate)
3752     {
3753 	int res = eval_index_inner(rettv, range,
3754 		empty1 ? NULL : &var1, empty2 ? NULL : &var2,
3755 		key, keylen, verbose);
3756 	if (!empty1)
3757 	    clear_tv(&var1);
3758 	if (range)
3759 	    clear_tv(&var2);
3760 	return res;
3761     }
3762     return OK;
3763 }
3764 
3765 /*
3766  * Check if "rettv" can have an [index] or [sli:ce]
3767  */
3768     int
3769 check_can_index(typval_T *rettv, int evaluate, int verbose)
3770 {
3771     switch (rettv->v_type)
3772     {
3773 	case VAR_FUNC:
3774 	case VAR_PARTIAL:
3775 	    if (verbose)
3776 		emsg(_("E695: Cannot index a Funcref"));
3777 	    return FAIL;
3778 	case VAR_FLOAT:
3779 #ifdef FEAT_FLOAT
3780 	    if (verbose)
3781 		emsg(_(e_float_as_string));
3782 	    return FAIL;
3783 #endif
3784 	case VAR_BOOL:
3785 	case VAR_SPECIAL:
3786 	case VAR_JOB:
3787 	case VAR_CHANNEL:
3788 	    if (verbose)
3789 		emsg(_(e_cannot_index_special_variable));
3790 	    return FAIL;
3791 	case VAR_UNKNOWN:
3792 	case VAR_ANY:
3793 	case VAR_VOID:
3794 	    if (evaluate)
3795 	    {
3796 		emsg(_(e_cannot_index_special_variable));
3797 		return FAIL;
3798 	    }
3799 	    // FALLTHROUGH
3800 
3801 	case VAR_STRING:
3802 	case VAR_LIST:
3803 	case VAR_DICT:
3804 	case VAR_BLOB:
3805 	    break;
3806 	case VAR_NUMBER:
3807 	    if (in_vim9script())
3808 		emsg(_(e_cannot_index_number));
3809 	    break;
3810     }
3811     return OK;
3812 }
3813 
3814 /*
3815  * Apply index or range to "rettv".
3816  * "var1" is the first index, NULL for [:expr].
3817  * "var2" is the second index, NULL for [expr] and [expr: ]
3818  * Alternatively, "key" is not NULL, then key[keylen] is the dict index.
3819  */
3820     int
3821 eval_index_inner(
3822 	typval_T    *rettv,
3823 	int	    is_range,
3824 	typval_T    *var1,
3825 	typval_T    *var2,
3826 	char_u	    *key,
3827 	int	    keylen,
3828 	int	    verbose)
3829 {
3830     long	n1, n2 = 0;
3831     long	len;
3832 
3833     n1 = 0;
3834     if (var1 != NULL && rettv->v_type != VAR_DICT)
3835 	n1 = tv_get_number(var1);
3836 
3837     if (is_range)
3838     {
3839 	if (rettv->v_type == VAR_DICT)
3840 	{
3841 	    if (verbose)
3842 		emsg(_(e_cannot_slice_dictionary));
3843 	    return FAIL;
3844 	}
3845 	if (var2 == NULL)
3846 	    n2 = -1;
3847 	else
3848 	    n2 = tv_get_number(var2);
3849     }
3850 
3851     switch (rettv->v_type)
3852     {
3853 	case VAR_UNKNOWN:
3854 	case VAR_ANY:
3855 	case VAR_VOID:
3856 	case VAR_FUNC:
3857 	case VAR_PARTIAL:
3858 	case VAR_FLOAT:
3859 	case VAR_BOOL:
3860 	case VAR_SPECIAL:
3861 	case VAR_JOB:
3862 	case VAR_CHANNEL:
3863 	    break; // not evaluating, skipping over subscript
3864 
3865 	case VAR_NUMBER:
3866 	case VAR_STRING:
3867 	    {
3868 		char_u	*s = tv_get_string(rettv);
3869 
3870 		len = (long)STRLEN(s);
3871 		if (in_vim9script())
3872 		{
3873 		    if (is_range)
3874 			s = string_slice(s, n1, n2);
3875 		    else
3876 			s = char_from_string(s, n1);
3877 		}
3878 		else if (is_range)
3879 		{
3880 		    // The resulting variable is a substring.  If the indexes
3881 		    // are out of range the result is empty.
3882 		    if (n1 < 0)
3883 		    {
3884 			n1 = len + n1;
3885 			if (n1 < 0)
3886 			    n1 = 0;
3887 		    }
3888 		    if (n2 < 0)
3889 			n2 = len + n2;
3890 		    else if (n2 >= len)
3891 			n2 = len;
3892 		    if (n1 >= len || n2 < 0 || n1 > n2)
3893 			s = NULL;
3894 		    else
3895 			s = vim_strnsave(s + n1, n2 - n1 + 1);
3896 		}
3897 		else
3898 		{
3899 		    // The resulting variable is a string of a single
3900 		    // character.  If the index is too big or negative the
3901 		    // result is empty.
3902 		    if (n1 >= len || n1 < 0)
3903 			s = NULL;
3904 		    else
3905 			s = vim_strnsave(s + n1, 1);
3906 		}
3907 		clear_tv(rettv);
3908 		rettv->v_type = VAR_STRING;
3909 		rettv->vval.v_string = s;
3910 	    }
3911 	    break;
3912 
3913 	case VAR_BLOB:
3914 	    len = blob_len(rettv->vval.v_blob);
3915 	    if (is_range)
3916 	    {
3917 		// The resulting variable is a sub-blob.  If the indexes
3918 		// are out of range the result is empty.
3919 		if (n1 < 0)
3920 		{
3921 		    n1 = len + n1;
3922 		    if (n1 < 0)
3923 			n1 = 0;
3924 		}
3925 		if (n2 < 0)
3926 		    n2 = len + n2;
3927 		else if (n2 >= len)
3928 		    n2 = len - 1;
3929 		if (n1 >= len || n2 < 0 || n1 > n2)
3930 		{
3931 		    clear_tv(rettv);
3932 		    rettv->v_type = VAR_BLOB;
3933 		    rettv->vval.v_blob = NULL;
3934 		}
3935 		else
3936 		{
3937 		    blob_T  *blob = blob_alloc();
3938 		    long    i;
3939 
3940 		    if (blob != NULL)
3941 		    {
3942 			if (ga_grow(&blob->bv_ga, n2 - n1 + 1) == FAIL)
3943 			{
3944 			    blob_free(blob);
3945 			    return FAIL;
3946 			}
3947 			blob->bv_ga.ga_len = n2 - n1 + 1;
3948 			for (i = n1; i <= n2; i++)
3949 			    blob_set(blob, i - n1,
3950 					  blob_get(rettv->vval.v_blob, i));
3951 
3952 			clear_tv(rettv);
3953 			rettv_blob_set(rettv, blob);
3954 		    }
3955 		}
3956 	    }
3957 	    else
3958 	    {
3959 		// The resulting variable is a byte value.
3960 		// If the index is too big or negative that is an error.
3961 		if (n1 < 0)
3962 		    n1 = len + n1;
3963 		if (n1 < len && n1 >= 0)
3964 		{
3965 		    int v = blob_get(rettv->vval.v_blob, n1);
3966 
3967 		    clear_tv(rettv);
3968 		    rettv->v_type = VAR_NUMBER;
3969 		    rettv->vval.v_number = v;
3970 		}
3971 		else
3972 		    semsg(_(e_blobidx), n1);
3973 	    }
3974 	    break;
3975 
3976 	case VAR_LIST:
3977 	    if (var1 == NULL)
3978 		n1 = 0;
3979 	    if (var2 == NULL)
3980 		n2 = -1;
3981 	    if (list_slice_or_index(rettv->vval.v_list,
3982 				    is_range, n1, n2, rettv, verbose) == FAIL)
3983 		return FAIL;
3984 	    break;
3985 
3986 	case VAR_DICT:
3987 	    {
3988 		dictitem_T	*item;
3989 		typval_T	tmp;
3990 
3991 		if (key == NULL)
3992 		{
3993 		    key = tv_get_string_chk(var1);
3994 		    if (key == NULL)
3995 			return FAIL;
3996 		}
3997 
3998 		item = dict_find(rettv->vval.v_dict, key, (int)keylen);
3999 
4000 		if (item == NULL && verbose)
4001 		    semsg(_(e_dictkey), key);
4002 		if (item == NULL)
4003 		    return FAIL;
4004 
4005 		copy_tv(&item->di_tv, &tmp);
4006 		clear_tv(rettv);
4007 		*rettv = tmp;
4008 	    }
4009 	    break;
4010     }
4011     return OK;
4012 }
4013 
4014 /*
4015  * Return the function name of partial "pt".
4016  */
4017     char_u *
4018 partial_name(partial_T *pt)
4019 {
4020     if (pt->pt_name != NULL)
4021 	return pt->pt_name;
4022     if (pt->pt_func != NULL)
4023 	return pt->pt_func->uf_name;
4024     return (char_u *)"";
4025 }
4026 
4027     static void
4028 partial_free(partial_T *pt)
4029 {
4030     int i;
4031 
4032     for (i = 0; i < pt->pt_argc; ++i)
4033 	clear_tv(&pt->pt_argv[i]);
4034     vim_free(pt->pt_argv);
4035     dict_unref(pt->pt_dict);
4036     if (pt->pt_name != NULL)
4037     {
4038 	func_unref(pt->pt_name);
4039 	vim_free(pt->pt_name);
4040     }
4041     else
4042 	func_ptr_unref(pt->pt_func);
4043 
4044     // Decrease the reference count for the context of a closure.  If down
4045     // to the minimum it may be time to free it.
4046     if (pt->pt_funcstack != NULL)
4047     {
4048 	--pt->pt_funcstack->fs_refcount;
4049 	funcstack_check_refcount(pt->pt_funcstack);
4050     }
4051 
4052     vim_free(pt);
4053 }
4054 
4055 /*
4056  * Unreference a closure: decrement the reference count and free it when it
4057  * becomes zero.
4058  */
4059     void
4060 partial_unref(partial_T *pt)
4061 {
4062     if (pt != NULL)
4063     {
4064 	if (--pt->pt_refcount <= 0)
4065 	    partial_free(pt);
4066 
4067 	// If the reference count goes down to one, the funcstack may be the
4068 	// only reference and can be freed if no other partials reference it.
4069 	else if (pt->pt_refcount == 1 && pt->pt_funcstack != NULL)
4070 	    funcstack_check_refcount(pt->pt_funcstack);
4071     }
4072 }
4073 
4074 /*
4075  * Return the next (unique) copy ID.
4076  * Used for serializing nested structures.
4077  */
4078     int
4079 get_copyID(void)
4080 {
4081     current_copyID += COPYID_INC;
4082     return current_copyID;
4083 }
4084 
4085 /*
4086  * Garbage collection for lists and dictionaries.
4087  *
4088  * We use reference counts to be able to free most items right away when they
4089  * are no longer used.  But for composite items it's possible that it becomes
4090  * unused while the reference count is > 0: When there is a recursive
4091  * reference.  Example:
4092  *	:let l = [1, 2, 3]
4093  *	:let d = {9: l}
4094  *	:let l[1] = d
4095  *
4096  * Since this is quite unusual we handle this with garbage collection: every
4097  * once in a while find out which lists and dicts are not referenced from any
4098  * variable.
4099  *
4100  * Here is a good reference text about garbage collection (refers to Python
4101  * but it applies to all reference-counting mechanisms):
4102  *	http://python.ca/nas/python/gc/
4103  */
4104 
4105 /*
4106  * Do garbage collection for lists and dicts.
4107  * When "testing" is TRUE this is called from test_garbagecollect_now().
4108  * Return TRUE if some memory was freed.
4109  */
4110     int
4111 garbage_collect(int testing)
4112 {
4113     int		copyID;
4114     int		abort = FALSE;
4115     buf_T	*buf;
4116     win_T	*wp;
4117     int		did_free = FALSE;
4118     tabpage_T	*tp;
4119 
4120     if (!testing)
4121     {
4122 	// Only do this once.
4123 	want_garbage_collect = FALSE;
4124 	may_garbage_collect = FALSE;
4125 	garbage_collect_at_exit = FALSE;
4126     }
4127 
4128     // The execution stack can grow big, limit the size.
4129     if (exestack.ga_maxlen - exestack.ga_len > 500)
4130     {
4131 	size_t	new_len;
4132 	char_u	*pp;
4133 	int	n;
4134 
4135 	// Keep 150% of the current size, with a minimum of the growth size.
4136 	n = exestack.ga_len / 2;
4137 	if (n < exestack.ga_growsize)
4138 	    n = exestack.ga_growsize;
4139 
4140 	// Don't make it bigger though.
4141 	if (exestack.ga_len + n < exestack.ga_maxlen)
4142 	{
4143 	    new_len = exestack.ga_itemsize * (exestack.ga_len + n);
4144 	    pp = vim_realloc(exestack.ga_data, new_len);
4145 	    if (pp == NULL)
4146 		return FAIL;
4147 	    exestack.ga_maxlen = exestack.ga_len + n;
4148 	    exestack.ga_data = pp;
4149 	}
4150     }
4151 
4152     // We advance by two because we add one for items referenced through
4153     // previous_funccal.
4154     copyID = get_copyID();
4155 
4156     /*
4157      * 1. Go through all accessible variables and mark all lists and dicts
4158      *    with copyID.
4159      */
4160 
4161     // Don't free variables in the previous_funccal list unless they are only
4162     // referenced through previous_funccal.  This must be first, because if
4163     // the item is referenced elsewhere the funccal must not be freed.
4164     abort = abort || set_ref_in_previous_funccal(copyID);
4165 
4166     // script-local variables
4167     abort = abort || garbage_collect_scriptvars(copyID);
4168 
4169     // buffer-local variables
4170     FOR_ALL_BUFFERS(buf)
4171 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
4172 								  NULL, NULL);
4173 
4174     // window-local variables
4175     FOR_ALL_TAB_WINDOWS(tp, wp)
4176 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4177 								  NULL, NULL);
4178     if (aucmd_win != NULL)
4179 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
4180 								  NULL, NULL);
4181 #ifdef FEAT_PROP_POPUP
4182     FOR_ALL_POPUPWINS(wp)
4183 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4184 								  NULL, NULL);
4185     FOR_ALL_TABPAGES(tp)
4186 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
4187 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4188 								  NULL, NULL);
4189 #endif
4190 
4191     // tabpage-local variables
4192     FOR_ALL_TABPAGES(tp)
4193 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
4194 								  NULL, NULL);
4195     // global variables
4196     abort = abort || garbage_collect_globvars(copyID);
4197 
4198     // function-local variables
4199     abort = abort || set_ref_in_call_stack(copyID);
4200 
4201     // named functions (matters for closures)
4202     abort = abort || set_ref_in_functions(copyID);
4203 
4204     // function call arguments, if v:testing is set.
4205     abort = abort || set_ref_in_func_args(copyID);
4206 
4207     // v: vars
4208     abort = abort || garbage_collect_vimvars(copyID);
4209 
4210     // callbacks in buffers
4211     abort = abort || set_ref_in_buffers(copyID);
4212 
4213 #ifdef FEAT_LUA
4214     abort = abort || set_ref_in_lua(copyID);
4215 #endif
4216 
4217 #ifdef FEAT_PYTHON
4218     abort = abort || set_ref_in_python(copyID);
4219 #endif
4220 
4221 #ifdef FEAT_PYTHON3
4222     abort = abort || set_ref_in_python3(copyID);
4223 #endif
4224 
4225 #ifdef FEAT_JOB_CHANNEL
4226     abort = abort || set_ref_in_channel(copyID);
4227     abort = abort || set_ref_in_job(copyID);
4228 #endif
4229 #ifdef FEAT_NETBEANS_INTG
4230     abort = abort || set_ref_in_nb_channel(copyID);
4231 #endif
4232 
4233 #ifdef FEAT_TIMERS
4234     abort = abort || set_ref_in_timer(copyID);
4235 #endif
4236 
4237 #ifdef FEAT_QUICKFIX
4238     abort = abort || set_ref_in_quickfix(copyID);
4239 #endif
4240 
4241 #ifdef FEAT_TERMINAL
4242     abort = abort || set_ref_in_term(copyID);
4243 #endif
4244 
4245 #ifdef FEAT_PROP_POPUP
4246     abort = abort || set_ref_in_popups(copyID);
4247 #endif
4248 
4249     if (!abort)
4250     {
4251 	/*
4252 	 * 2. Free lists and dictionaries that are not referenced.
4253 	 */
4254 	did_free = free_unref_items(copyID);
4255 
4256 	/*
4257 	 * 3. Check if any funccal can be freed now.
4258 	 *    This may call us back recursively.
4259 	 */
4260 	free_unref_funccal(copyID, testing);
4261     }
4262     else if (p_verbose > 0)
4263     {
4264 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
4265     }
4266 
4267     return did_free;
4268 }
4269 
4270 /*
4271  * Free lists, dictionaries, channels and jobs that are no longer referenced.
4272  */
4273     static int
4274 free_unref_items(int copyID)
4275 {
4276     int		did_free = FALSE;
4277 
4278     // Let all "free" functions know that we are here.  This means no
4279     // dictionaries, lists, channels or jobs are to be freed, because we will
4280     // do that here.
4281     in_free_unref_items = TRUE;
4282 
4283     /*
4284      * PASS 1: free the contents of the items.  We don't free the items
4285      * themselves yet, so that it is possible to decrement refcount counters
4286      */
4287 
4288     // Go through the list of dicts and free items without the copyID.
4289     did_free |= dict_free_nonref(copyID);
4290 
4291     // Go through the list of lists and free items without the copyID.
4292     did_free |= list_free_nonref(copyID);
4293 
4294 #ifdef FEAT_JOB_CHANNEL
4295     // Go through the list of jobs and free items without the copyID. This
4296     // must happen before doing channels, because jobs refer to channels, but
4297     // the reference from the channel to the job isn't tracked.
4298     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4299 
4300     // Go through the list of channels and free items without the copyID.
4301     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4302 #endif
4303 
4304     /*
4305      * PASS 2: free the items themselves.
4306      */
4307     dict_free_items(copyID);
4308     list_free_items(copyID);
4309 
4310 #ifdef FEAT_JOB_CHANNEL
4311     // Go through the list of jobs and free items without the copyID. This
4312     // must happen before doing channels, because jobs refer to channels, but
4313     // the reference from the channel to the job isn't tracked.
4314     free_unused_jobs(copyID, COPYID_MASK);
4315 
4316     // Go through the list of channels and free items without the copyID.
4317     free_unused_channels(copyID, COPYID_MASK);
4318 #endif
4319 
4320     in_free_unref_items = FALSE;
4321 
4322     return did_free;
4323 }
4324 
4325 /*
4326  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4327  * "list_stack" is used to add lists to be marked.  Can be NULL.
4328  *
4329  * Returns TRUE if setting references failed somehow.
4330  */
4331     int
4332 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4333 {
4334     int		todo;
4335     int		abort = FALSE;
4336     hashitem_T	*hi;
4337     hashtab_T	*cur_ht;
4338     ht_stack_T	*ht_stack = NULL;
4339     ht_stack_T	*tempitem;
4340 
4341     cur_ht = ht;
4342     for (;;)
4343     {
4344 	if (!abort)
4345 	{
4346 	    // Mark each item in the hashtab.  If the item contains a hashtab
4347 	    // it is added to ht_stack, if it contains a list it is added to
4348 	    // list_stack.
4349 	    todo = (int)cur_ht->ht_used;
4350 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4351 		if (!HASHITEM_EMPTY(hi))
4352 		{
4353 		    --todo;
4354 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4355 						       &ht_stack, list_stack);
4356 		}
4357 	}
4358 
4359 	if (ht_stack == NULL)
4360 	    break;
4361 
4362 	// take an item from the stack
4363 	cur_ht = ht_stack->ht;
4364 	tempitem = ht_stack;
4365 	ht_stack = ht_stack->prev;
4366 	free(tempitem);
4367     }
4368 
4369     return abort;
4370 }
4371 
4372 /*
4373  * Mark a dict and its items with "copyID".
4374  * Returns TRUE if setting references failed somehow.
4375  */
4376     int
4377 set_ref_in_dict(dict_T *d, int copyID)
4378 {
4379     if (d != NULL && d->dv_copyID != copyID)
4380     {
4381 	d->dv_copyID = copyID;
4382 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4383     }
4384     return FALSE;
4385 }
4386 
4387 /*
4388  * Mark a list and its items with "copyID".
4389  * Returns TRUE if setting references failed somehow.
4390  */
4391     int
4392 set_ref_in_list(list_T *ll, int copyID)
4393 {
4394     if (ll != NULL && ll->lv_copyID != copyID)
4395     {
4396 	ll->lv_copyID = copyID;
4397 	return set_ref_in_list_items(ll, copyID, NULL);
4398     }
4399     return FALSE;
4400 }
4401 
4402 /*
4403  * Mark all lists and dicts referenced through list "l" with "copyID".
4404  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4405  *
4406  * Returns TRUE if setting references failed somehow.
4407  */
4408     int
4409 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4410 {
4411     listitem_T	 *li;
4412     int		 abort = FALSE;
4413     list_T	 *cur_l;
4414     list_stack_T *list_stack = NULL;
4415     list_stack_T *tempitem;
4416 
4417     cur_l = l;
4418     for (;;)
4419     {
4420 	if (!abort && cur_l->lv_first != &range_list_item)
4421 	    // Mark each item in the list.  If the item contains a hashtab
4422 	    // it is added to ht_stack, if it contains a list it is added to
4423 	    // list_stack.
4424 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4425 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4426 						       ht_stack, &list_stack);
4427 	if (list_stack == NULL)
4428 	    break;
4429 
4430 	// take an item from the stack
4431 	cur_l = list_stack->list;
4432 	tempitem = list_stack;
4433 	list_stack = list_stack->prev;
4434 	free(tempitem);
4435     }
4436 
4437     return abort;
4438 }
4439 
4440 /*
4441  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4442  * "list_stack" is used to add lists to be marked.  Can be NULL.
4443  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4444  *
4445  * Returns TRUE if setting references failed somehow.
4446  */
4447     int
4448 set_ref_in_item(
4449     typval_T	    *tv,
4450     int		    copyID,
4451     ht_stack_T	    **ht_stack,
4452     list_stack_T    **list_stack)
4453 {
4454     int		abort = FALSE;
4455 
4456     if (tv->v_type == VAR_DICT)
4457     {
4458 	dict_T	*dd = tv->vval.v_dict;
4459 
4460 	if (dd != NULL && dd->dv_copyID != copyID)
4461 	{
4462 	    // Didn't see this dict yet.
4463 	    dd->dv_copyID = copyID;
4464 	    if (ht_stack == NULL)
4465 	    {
4466 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4467 	    }
4468 	    else
4469 	    {
4470 		ht_stack_T *newitem = ALLOC_ONE(ht_stack_T);
4471 
4472 		if (newitem == NULL)
4473 		    abort = TRUE;
4474 		else
4475 		{
4476 		    newitem->ht = &dd->dv_hashtab;
4477 		    newitem->prev = *ht_stack;
4478 		    *ht_stack = newitem;
4479 		}
4480 	    }
4481 	}
4482     }
4483     else if (tv->v_type == VAR_LIST)
4484     {
4485 	list_T	*ll = tv->vval.v_list;
4486 
4487 	if (ll != NULL && ll->lv_copyID != copyID)
4488 	{
4489 	    // Didn't see this list yet.
4490 	    ll->lv_copyID = copyID;
4491 	    if (list_stack == NULL)
4492 	    {
4493 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4494 	    }
4495 	    else
4496 	    {
4497 		list_stack_T *newitem = ALLOC_ONE(list_stack_T);
4498 
4499 		if (newitem == NULL)
4500 		    abort = TRUE;
4501 		else
4502 		{
4503 		    newitem->list = ll;
4504 		    newitem->prev = *list_stack;
4505 		    *list_stack = newitem;
4506 		}
4507 	    }
4508 	}
4509     }
4510     else if (tv->v_type == VAR_FUNC)
4511     {
4512 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4513     }
4514     else if (tv->v_type == VAR_PARTIAL)
4515     {
4516 	partial_T	*pt = tv->vval.v_partial;
4517 	int		i;
4518 
4519 	if (pt != NULL && pt->pt_copyID != copyID)
4520 	{
4521 	    // Didn't see this partial yet.
4522 	    pt->pt_copyID = copyID;
4523 
4524 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4525 
4526 	    if (pt->pt_dict != NULL)
4527 	    {
4528 		typval_T dtv;
4529 
4530 		dtv.v_type = VAR_DICT;
4531 		dtv.vval.v_dict = pt->pt_dict;
4532 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4533 	    }
4534 
4535 	    for (i = 0; i < pt->pt_argc; ++i)
4536 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4537 							ht_stack, list_stack);
4538 	    if (pt->pt_funcstack != NULL)
4539 	    {
4540 		typval_T    *stack = pt->pt_funcstack->fs_ga.ga_data;
4541 
4542 		for (i = 0; i < pt->pt_funcstack->fs_ga.ga_len; ++i)
4543 		    abort = abort || set_ref_in_item(stack + i, copyID,
4544 							 ht_stack, list_stack);
4545 	    }
4546 
4547 	}
4548     }
4549 #ifdef FEAT_JOB_CHANNEL
4550     else if (tv->v_type == VAR_JOB)
4551     {
4552 	job_T	    *job = tv->vval.v_job;
4553 	typval_T    dtv;
4554 
4555 	if (job != NULL && job->jv_copyID != copyID)
4556 	{
4557 	    job->jv_copyID = copyID;
4558 	    if (job->jv_channel != NULL)
4559 	    {
4560 		dtv.v_type = VAR_CHANNEL;
4561 		dtv.vval.v_channel = job->jv_channel;
4562 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4563 	    }
4564 	    if (job->jv_exit_cb.cb_partial != NULL)
4565 	    {
4566 		dtv.v_type = VAR_PARTIAL;
4567 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4568 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4569 	    }
4570 	}
4571     }
4572     else if (tv->v_type == VAR_CHANNEL)
4573     {
4574 	channel_T   *ch =tv->vval.v_channel;
4575 	ch_part_T   part;
4576 	typval_T    dtv;
4577 	jsonq_T	    *jq;
4578 	cbq_T	    *cq;
4579 
4580 	if (ch != NULL && ch->ch_copyID != copyID)
4581 	{
4582 	    ch->ch_copyID = copyID;
4583 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4584 	    {
4585 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4586 							     jq = jq->jq_next)
4587 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4588 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4589 							     cq = cq->cq_next)
4590 		    if (cq->cq_callback.cb_partial != NULL)
4591 		    {
4592 			dtv.v_type = VAR_PARTIAL;
4593 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4594 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4595 		    }
4596 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4597 		{
4598 		    dtv.v_type = VAR_PARTIAL;
4599 		    dtv.vval.v_partial =
4600 				      ch->ch_part[part].ch_callback.cb_partial;
4601 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4602 		}
4603 	    }
4604 	    if (ch->ch_callback.cb_partial != NULL)
4605 	    {
4606 		dtv.v_type = VAR_PARTIAL;
4607 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4608 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4609 	    }
4610 	    if (ch->ch_close_cb.cb_partial != NULL)
4611 	    {
4612 		dtv.v_type = VAR_PARTIAL;
4613 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4614 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4615 	    }
4616 	}
4617     }
4618 #endif
4619     return abort;
4620 }
4621 
4622 /*
4623  * Return a string with the string representation of a variable.
4624  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4625  * "numbuf" is used for a number.
4626  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4627  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4628  * stings as "string()", otherwise does not put quotes around strings, as
4629  * ":echo" displays values.
4630  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4631  * are replaced with "...".
4632  * May return NULL.
4633  */
4634     char_u *
4635 echo_string_core(
4636     typval_T	*tv,
4637     char_u	**tofree,
4638     char_u	*numbuf,
4639     int		copyID,
4640     int		echo_style,
4641     int		restore_copyID,
4642     int		composite_val)
4643 {
4644     static int	recurse = 0;
4645     char_u	*r = NULL;
4646 
4647     if (recurse >= DICT_MAXNEST)
4648     {
4649 	if (!did_echo_string_emsg)
4650 	{
4651 	    // Only give this message once for a recursive call to avoid
4652 	    // flooding the user with errors.  And stop iterating over lists
4653 	    // and dicts.
4654 	    did_echo_string_emsg = TRUE;
4655 	    emsg(_("E724: variable nested too deep for displaying"));
4656 	}
4657 	*tofree = NULL;
4658 	return (char_u *)"{E724}";
4659     }
4660     ++recurse;
4661 
4662     switch (tv->v_type)
4663     {
4664 	case VAR_STRING:
4665 	    if (echo_style && !composite_val)
4666 	    {
4667 		*tofree = NULL;
4668 		r = tv->vval.v_string;
4669 		if (r == NULL)
4670 		    r = (char_u *)"";
4671 	    }
4672 	    else
4673 	    {
4674 		*tofree = string_quote(tv->vval.v_string, FALSE);
4675 		r = *tofree;
4676 	    }
4677 	    break;
4678 
4679 	case VAR_FUNC:
4680 	    if (echo_style)
4681 	    {
4682 		*tofree = NULL;
4683 		r = tv->vval.v_string;
4684 	    }
4685 	    else
4686 	    {
4687 		*tofree = string_quote(tv->vval.v_string, TRUE);
4688 		r = *tofree;
4689 	    }
4690 	    break;
4691 
4692 	case VAR_PARTIAL:
4693 	    {
4694 		partial_T   *pt = tv->vval.v_partial;
4695 		char_u	    *fname = string_quote(pt == NULL ? NULL
4696 						    : partial_name(pt), FALSE);
4697 		garray_T    ga;
4698 		int	    i;
4699 		char_u	    *tf;
4700 
4701 		ga_init2(&ga, 1, 100);
4702 		ga_concat(&ga, (char_u *)"function(");
4703 		if (fname != NULL)
4704 		{
4705 		    ga_concat(&ga, fname);
4706 		    vim_free(fname);
4707 		}
4708 		if (pt != NULL && pt->pt_argc > 0)
4709 		{
4710 		    ga_concat(&ga, (char_u *)", [");
4711 		    for (i = 0; i < pt->pt_argc; ++i)
4712 		    {
4713 			if (i > 0)
4714 			    ga_concat(&ga, (char_u *)", ");
4715 			ga_concat(&ga,
4716 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
4717 			vim_free(tf);
4718 		    }
4719 		    ga_concat(&ga, (char_u *)"]");
4720 		}
4721 		if (pt != NULL && pt->pt_dict != NULL)
4722 		{
4723 		    typval_T dtv;
4724 
4725 		    ga_concat(&ga, (char_u *)", ");
4726 		    dtv.v_type = VAR_DICT;
4727 		    dtv.vval.v_dict = pt->pt_dict;
4728 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
4729 		    vim_free(tf);
4730 		}
4731 		ga_concat(&ga, (char_u *)")");
4732 
4733 		*tofree = ga.ga_data;
4734 		r = *tofree;
4735 		break;
4736 	    }
4737 
4738 	case VAR_BLOB:
4739 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
4740 	    break;
4741 
4742 	case VAR_LIST:
4743 	    if (tv->vval.v_list == NULL)
4744 	    {
4745 		// NULL list is equivalent to empty list.
4746 		*tofree = NULL;
4747 		r = (char_u *)"[]";
4748 	    }
4749 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
4750 		    && tv->vval.v_list->lv_len > 0)
4751 	    {
4752 		*tofree = NULL;
4753 		r = (char_u *)"[...]";
4754 	    }
4755 	    else
4756 	    {
4757 		int old_copyID = tv->vval.v_list->lv_copyID;
4758 
4759 		tv->vval.v_list->lv_copyID = copyID;
4760 		*tofree = list2string(tv, copyID, restore_copyID);
4761 		if (restore_copyID)
4762 		    tv->vval.v_list->lv_copyID = old_copyID;
4763 		r = *tofree;
4764 	    }
4765 	    break;
4766 
4767 	case VAR_DICT:
4768 	    if (tv->vval.v_dict == NULL)
4769 	    {
4770 		// NULL dict is equivalent to empty dict.
4771 		*tofree = NULL;
4772 		r = (char_u *)"{}";
4773 	    }
4774 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
4775 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
4776 	    {
4777 		*tofree = NULL;
4778 		r = (char_u *)"{...}";
4779 	    }
4780 	    else
4781 	    {
4782 		int old_copyID = tv->vval.v_dict->dv_copyID;
4783 
4784 		tv->vval.v_dict->dv_copyID = copyID;
4785 		*tofree = dict2string(tv, copyID, restore_copyID);
4786 		if (restore_copyID)
4787 		    tv->vval.v_dict->dv_copyID = old_copyID;
4788 		r = *tofree;
4789 	    }
4790 	    break;
4791 
4792 	case VAR_NUMBER:
4793 	case VAR_UNKNOWN:
4794 	case VAR_ANY:
4795 	case VAR_VOID:
4796 	    *tofree = NULL;
4797 	    r = tv_get_string_buf(tv, numbuf);
4798 	    break;
4799 
4800 	case VAR_JOB:
4801 	case VAR_CHANNEL:
4802 	    *tofree = NULL;
4803 	    r = tv_get_string_buf(tv, numbuf);
4804 	    if (composite_val)
4805 	    {
4806 		*tofree = string_quote(r, FALSE);
4807 		r = *tofree;
4808 	    }
4809 	    break;
4810 
4811 	case VAR_FLOAT:
4812 #ifdef FEAT_FLOAT
4813 	    *tofree = NULL;
4814 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
4815 	    r = numbuf;
4816 	    break;
4817 #endif
4818 
4819 	case VAR_BOOL:
4820 	case VAR_SPECIAL:
4821 	    *tofree = NULL;
4822 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
4823 	    break;
4824     }
4825 
4826     if (--recurse == 0)
4827 	did_echo_string_emsg = FALSE;
4828     return r;
4829 }
4830 
4831 /*
4832  * Return a string with the string representation of a variable.
4833  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4834  * "numbuf" is used for a number.
4835  * Does not put quotes around strings, as ":echo" displays values.
4836  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4837  * May return NULL.
4838  */
4839     char_u *
4840 echo_string(
4841     typval_T	*tv,
4842     char_u	**tofree,
4843     char_u	*numbuf,
4844     int		copyID)
4845 {
4846     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
4847 }
4848 
4849 /*
4850  * Return string "str" in ' quotes, doubling ' characters.
4851  * If "str" is NULL an empty string is assumed.
4852  * If "function" is TRUE make it function('string').
4853  */
4854     char_u *
4855 string_quote(char_u *str, int function)
4856 {
4857     unsigned	len;
4858     char_u	*p, *r, *s;
4859 
4860     len = (function ? 13 : 3);
4861     if (str != NULL)
4862     {
4863 	len += (unsigned)STRLEN(str);
4864 	for (p = str; *p != NUL; MB_PTR_ADV(p))
4865 	    if (*p == '\'')
4866 		++len;
4867     }
4868     s = r = alloc(len);
4869     if (r != NULL)
4870     {
4871 	if (function)
4872 	{
4873 	    STRCPY(r, "function('");
4874 	    r += 10;
4875 	}
4876 	else
4877 	    *r++ = '\'';
4878 	if (str != NULL)
4879 	    for (p = str; *p != NUL; )
4880 	    {
4881 		if (*p == '\'')
4882 		    *r++ = '\'';
4883 		MB_COPY_CHAR(p, r);
4884 	    }
4885 	*r++ = '\'';
4886 	if (function)
4887 	    *r++ = ')';
4888 	*r++ = NUL;
4889     }
4890     return s;
4891 }
4892 
4893 #if defined(FEAT_FLOAT) || defined(PROTO)
4894 /*
4895  * Convert the string "text" to a floating point number.
4896  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
4897  * this always uses a decimal point.
4898  * Returns the length of the text that was consumed.
4899  */
4900     int
4901 string2float(
4902     char_u	*text,
4903     float_T	*value)	    // result stored here
4904 {
4905     char	*s = (char *)text;
4906     float_T	f;
4907 
4908     // MS-Windows does not deal with "inf" and "nan" properly.
4909     if (STRNICMP(text, "inf", 3) == 0)
4910     {
4911 	*value = INFINITY;
4912 	return 3;
4913     }
4914     if (STRNICMP(text, "-inf", 3) == 0)
4915     {
4916 	*value = -INFINITY;
4917 	return 4;
4918     }
4919     if (STRNICMP(text, "nan", 3) == 0)
4920     {
4921 	*value = NAN;
4922 	return 3;
4923     }
4924     f = strtod(s, &s);
4925     *value = f;
4926     return (int)((char_u *)s - text);
4927 }
4928 #endif
4929 
4930 /*
4931  * Translate a String variable into a position.
4932  * Returns NULL when there is an error.
4933  */
4934     pos_T *
4935 var2fpos(
4936     typval_T	*varp,
4937     int		dollar_lnum,	// TRUE when $ is last line
4938     int		*fnum)		// set to fnum for '0, 'A, etc.
4939 {
4940     char_u		*name;
4941     static pos_T	pos;
4942     pos_T		*pp;
4943 
4944     // Argument can be [lnum, col, coladd].
4945     if (varp->v_type == VAR_LIST)
4946     {
4947 	list_T		*l;
4948 	int		len;
4949 	int		error = FALSE;
4950 	listitem_T	*li;
4951 
4952 	l = varp->vval.v_list;
4953 	if (l == NULL)
4954 	    return NULL;
4955 
4956 	// Get the line number
4957 	pos.lnum = list_find_nr(l, 0L, &error);
4958 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
4959 	    return NULL;	// invalid line number
4960 	len = (long)STRLEN(ml_get(pos.lnum));
4961 
4962 	// Get the column number
4963 	// We accept "$" for the column number: last column.
4964 	li = list_find(l, 1L);
4965 	if (li != NULL && li->li_tv.v_type == VAR_STRING
4966 		&& li->li_tv.vval.v_string != NULL
4967 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
4968 	{
4969 	    pos.col = len + 1;
4970 	}
4971 	else
4972 	{
4973 	    pos.col = list_find_nr(l, 1L, &error);
4974 	    if (error)
4975 		return NULL;
4976 	}
4977 
4978 	// Accept a position up to the NUL after the line.
4979 	if (pos.col == 0 || (int)pos.col > len + 1)
4980 	    return NULL;	// invalid column number
4981 	--pos.col;
4982 
4983 	// Get the virtual offset.  Defaults to zero.
4984 	pos.coladd = list_find_nr(l, 2L, &error);
4985 	if (error)
4986 	    pos.coladd = 0;
4987 
4988 	return &pos;
4989     }
4990 
4991     name = tv_get_string_chk(varp);
4992     if (name == NULL)
4993 	return NULL;
4994     if (name[0] == '.')				// cursor
4995 	return &curwin->w_cursor;
4996     if (name[0] == 'v' && name[1] == NUL)	// Visual start
4997     {
4998 	if (VIsual_active)
4999 	    return &VIsual;
5000 	return &curwin->w_cursor;
5001     }
5002     if (name[0] == '\'')			// mark
5003     {
5004 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
5005 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
5006 	    return NULL;
5007 	return pp;
5008     }
5009 
5010     pos.coladd = 0;
5011 
5012     if (name[0] == 'w' && dollar_lnum)
5013     {
5014 	pos.col = 0;
5015 	if (name[1] == '0')		// "w0": first visible line
5016 	{
5017 	    update_topline();
5018 	    // In silent Ex mode topline is zero, but that's not a valid line
5019 	    // number; use one instead.
5020 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
5021 	    return &pos;
5022 	}
5023 	else if (name[1] == '$')	// "w$": last visible line
5024 	{
5025 	    validate_botline();
5026 	    // In silent Ex mode botline is zero, return zero then.
5027 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
5028 	    return &pos;
5029 	}
5030     }
5031     else if (name[0] == '$')		// last column or line
5032     {
5033 	if (dollar_lnum)
5034 	{
5035 	    pos.lnum = curbuf->b_ml.ml_line_count;
5036 	    pos.col = 0;
5037 	}
5038 	else
5039 	{
5040 	    pos.lnum = curwin->w_cursor.lnum;
5041 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
5042 	}
5043 	return &pos;
5044     }
5045     return NULL;
5046 }
5047 
5048 /*
5049  * Convert list in "arg" into a position and optional file number.
5050  * When "fnump" is NULL there is no file number, only 3 items.
5051  * Note that the column is passed on as-is, the caller may want to decrement
5052  * it to use 1 for the first column.
5053  * Return FAIL when conversion is not possible, doesn't check the position for
5054  * validity.
5055  */
5056     int
5057 list2fpos(
5058     typval_T	*arg,
5059     pos_T	*posp,
5060     int		*fnump,
5061     colnr_T	*curswantp)
5062 {
5063     list_T	*l = arg->vval.v_list;
5064     long	i = 0;
5065     long	n;
5066 
5067     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
5068     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
5069     if (arg->v_type != VAR_LIST
5070 	    || l == NULL
5071 	    || l->lv_len < (fnump == NULL ? 2 : 3)
5072 	    || l->lv_len > (fnump == NULL ? 4 : 5))
5073 	return FAIL;
5074 
5075     if (fnump != NULL)
5076     {
5077 	n = list_find_nr(l, i++, NULL);	// fnum
5078 	if (n < 0)
5079 	    return FAIL;
5080 	if (n == 0)
5081 	    n = curbuf->b_fnum;		// current buffer
5082 	*fnump = n;
5083     }
5084 
5085     n = list_find_nr(l, i++, NULL);	// lnum
5086     if (n < 0)
5087 	return FAIL;
5088     posp->lnum = n;
5089 
5090     n = list_find_nr(l, i++, NULL);	// col
5091     if (n < 0)
5092 	return FAIL;
5093     posp->col = n;
5094 
5095     n = list_find_nr(l, i, NULL);	// off
5096     if (n < 0)
5097 	posp->coladd = 0;
5098     else
5099 	posp->coladd = n;
5100 
5101     if (curswantp != NULL)
5102 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
5103 
5104     return OK;
5105 }
5106 
5107 /*
5108  * Get the length of an environment variable name.
5109  * Advance "arg" to the first character after the name.
5110  * Return 0 for error.
5111  */
5112     int
5113 get_env_len(char_u **arg)
5114 {
5115     char_u	*p;
5116     int		len;
5117 
5118     for (p = *arg; vim_isIDc(*p); ++p)
5119 	;
5120     if (p == *arg)	    // no name found
5121 	return 0;
5122 
5123     len = (int)(p - *arg);
5124     *arg = p;
5125     return len;
5126 }
5127 
5128 /*
5129  * Get the length of the name of a function or internal variable.
5130  * "arg" is advanced to after the name.
5131  * Return 0 if something is wrong.
5132  */
5133     int
5134 get_id_len(char_u **arg)
5135 {
5136     char_u	*p;
5137     int		len;
5138 
5139     // Find the end of the name.
5140     for (p = *arg; eval_isnamec(*p); ++p)
5141     {
5142 	if (*p == ':')
5143 	{
5144 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5145 	    // slice "[n:]".  Also "xx:" is not a namespace.
5146 	    len = (int)(p - *arg);
5147 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
5148 		    || len > 1)
5149 		break;
5150 	}
5151     }
5152     if (p == *arg)	    // no name found
5153 	return 0;
5154 
5155     len = (int)(p - *arg);
5156     *arg = p;
5157 
5158     return len;
5159 }
5160 
5161 /*
5162  * Get the length of the name of a variable or function.
5163  * Only the name is recognized, does not handle ".key" or "[idx]".
5164  * "arg" is advanced to the first non-white character after the name.
5165  * Return -1 if curly braces expansion failed.
5166  * Return 0 if something else is wrong.
5167  * If the name contains 'magic' {}'s, expand them and return the
5168  * expanded name in an allocated string via 'alias' - caller must free.
5169  */
5170     int
5171 get_name_len(
5172     char_u	**arg,
5173     char_u	**alias,
5174     int		evaluate,
5175     int		verbose)
5176 {
5177     int		len;
5178     char_u	*p;
5179     char_u	*expr_start;
5180     char_u	*expr_end;
5181 
5182     *alias = NULL;  // default to no alias
5183 
5184     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
5185 						  && (*arg)[2] == (int)KE_SNR)
5186     {
5187 	// hard coded <SNR>, already translated
5188 	*arg += 3;
5189 	return get_id_len(arg) + 3;
5190     }
5191     len = eval_fname_script(*arg);
5192     if (len > 0)
5193     {
5194 	// literal "<SID>", "s:" or "<SNR>"
5195 	*arg += len;
5196     }
5197 
5198     /*
5199      * Find the end of the name; check for {} construction.
5200      */
5201     p = find_name_end(*arg, &expr_start, &expr_end,
5202 					       len > 0 ? 0 : FNE_CHECK_START);
5203     if (expr_start != NULL)
5204     {
5205 	char_u	*temp_string;
5206 
5207 	if (!evaluate)
5208 	{
5209 	    len += (int)(p - *arg);
5210 	    *arg = skipwhite(p);
5211 	    return len;
5212 	}
5213 
5214 	/*
5215 	 * Include any <SID> etc in the expanded string:
5216 	 * Thus the -len here.
5217 	 */
5218 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
5219 	if (temp_string == NULL)
5220 	    return -1;
5221 	*alias = temp_string;
5222 	*arg = skipwhite(p);
5223 	return (int)STRLEN(temp_string);
5224     }
5225 
5226     len += get_id_len(arg);
5227     // Only give an error when there is something, otherwise it will be
5228     // reported at a higher level.
5229     if (len == 0 && verbose && **arg != NUL)
5230 	semsg(_(e_invexpr2), *arg);
5231 
5232     return len;
5233 }
5234 
5235 /*
5236  * Find the end of a variable or function name, taking care of magic braces.
5237  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
5238  * start and end of the first magic braces item.
5239  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
5240  * Return a pointer to just after the name.  Equal to "arg" if there is no
5241  * valid name.
5242  */
5243     char_u *
5244 find_name_end(
5245     char_u	*arg,
5246     char_u	**expr_start,
5247     char_u	**expr_end,
5248     int		flags)
5249 {
5250     int		mb_nest = 0;
5251     int		br_nest = 0;
5252     char_u	*p;
5253     int		len;
5254     int		vim9script = in_vim9script();
5255 
5256     if (expr_start != NULL)
5257     {
5258 	*expr_start = NULL;
5259 	*expr_end = NULL;
5260     }
5261 
5262     // Quick check for valid starting character.
5263     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg)
5264 						&& (*arg != '{' || vim9script))
5265 	return arg;
5266 
5267     for (p = arg; *p != NUL
5268 		    && (eval_isnamec(*p)
5269 			|| (*p == '{' && !vim9script)
5270 			|| ((flags & FNE_INCL_BR) && (*p == '['
5271 					 || (*p == '.' && eval_isdictc(p[1]))))
5272 			|| mb_nest != 0
5273 			|| br_nest != 0); MB_PTR_ADV(p))
5274     {
5275 	if (*p == '\'')
5276 	{
5277 	    // skip over 'string' to avoid counting [ and ] inside it.
5278 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5279 		;
5280 	    if (*p == NUL)
5281 		break;
5282 	}
5283 	else if (*p == '"')
5284 	{
5285 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
5286 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5287 		if (*p == '\\' && p[1] != NUL)
5288 		    ++p;
5289 	    if (*p == NUL)
5290 		break;
5291 	}
5292 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5293 	{
5294 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5295 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
5296 	    len = (int)(p - arg);
5297 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5298 		    || (len > 1 && p[-1] != '}'))
5299 		break;
5300 	}
5301 
5302 	if (mb_nest == 0)
5303 	{
5304 	    if (*p == '[')
5305 		++br_nest;
5306 	    else if (*p == ']')
5307 		--br_nest;
5308 	}
5309 
5310 	if (br_nest == 0 && !vim9script)
5311 	{
5312 	    if (*p == '{')
5313 	    {
5314 		mb_nest++;
5315 		if (expr_start != NULL && *expr_start == NULL)
5316 		    *expr_start = p;
5317 	    }
5318 	    else if (*p == '}')
5319 	    {
5320 		mb_nest--;
5321 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5322 		    *expr_end = p;
5323 	    }
5324 	}
5325     }
5326 
5327     return p;
5328 }
5329 
5330 /*
5331  * Expands out the 'magic' {}'s in a variable/function name.
5332  * Note that this can call itself recursively, to deal with
5333  * constructs like foo{bar}{baz}{bam}
5334  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5335  *			"in_start"      ^
5336  *			"expr_start"	   ^
5337  *			"expr_end"		 ^
5338  *			"in_end"			    ^
5339  *
5340  * Returns a new allocated string, which the caller must free.
5341  * Returns NULL for failure.
5342  */
5343     static char_u *
5344 make_expanded_name(
5345     char_u	*in_start,
5346     char_u	*expr_start,
5347     char_u	*expr_end,
5348     char_u	*in_end)
5349 {
5350     char_u	c1;
5351     char_u	*retval = NULL;
5352     char_u	*temp_result;
5353 
5354     if (expr_end == NULL || in_end == NULL)
5355 	return NULL;
5356     *expr_start	= NUL;
5357     *expr_end = NUL;
5358     c1 = *in_end;
5359     *in_end = NUL;
5360 
5361     temp_result = eval_to_string(expr_start + 1, FALSE);
5362     if (temp_result != NULL)
5363     {
5364 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5365 						   + (in_end - expr_end) + 1);
5366 	if (retval != NULL)
5367 	{
5368 	    STRCPY(retval, in_start);
5369 	    STRCAT(retval, temp_result);
5370 	    STRCAT(retval, expr_end + 1);
5371 	}
5372     }
5373     vim_free(temp_result);
5374 
5375     *in_end = c1;		// put char back for error messages
5376     *expr_start = '{';
5377     *expr_end = '}';
5378 
5379     if (retval != NULL)
5380     {
5381 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5382 	if (expr_start != NULL)
5383 	{
5384 	    // Further expansion!
5385 	    temp_result = make_expanded_name(retval, expr_start,
5386 						       expr_end, temp_result);
5387 	    vim_free(retval);
5388 	    retval = temp_result;
5389 	}
5390     }
5391 
5392     return retval;
5393 }
5394 
5395 /*
5396  * Return TRUE if character "c" can be used in a variable or function name.
5397  * Does not include '{' or '}' for magic braces.
5398  */
5399     int
5400 eval_isnamec(int c)
5401 {
5402     return ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR;
5403 }
5404 
5405 /*
5406  * Return TRUE if character "c" can be used as the first character in a
5407  * variable or function name (excluding '{' and '}').
5408  */
5409     int
5410 eval_isnamec1(int c)
5411 {
5412     return ASCII_ISALPHA(c) || c == '_';
5413 }
5414 
5415 /*
5416  * Return TRUE if character "c" can be used as the first character of a
5417  * dictionary key.
5418  */
5419     int
5420 eval_isdictc(int c)
5421 {
5422     return ASCII_ISALNUM(c) || c == '_';
5423 }
5424 
5425 /*
5426  * Return the character "str[index]" where "index" is the character index.  If
5427  * "index" is out of range NULL is returned.
5428  */
5429     char_u *
5430 char_from_string(char_u *str, varnumber_T index)
5431 {
5432     size_t	    nbyte = 0;
5433     varnumber_T	    nchar = index;
5434     size_t	    slen;
5435 
5436     if (str == NULL || index < 0)
5437 	return NULL;
5438     slen = STRLEN(str);
5439     while (nchar > 0 && nbyte < slen)
5440     {
5441 	nbyte += MB_CPTR2LEN(str + nbyte);
5442 	--nchar;
5443     }
5444     if (nbyte >= slen)
5445 	return NULL;
5446     return vim_strnsave(str + nbyte, MB_CPTR2LEN(str + nbyte));
5447 }
5448 
5449 /*
5450  * Get the byte index for character index "idx" in string "str" with length
5451  * "str_len".
5452  * If going over the end return "str_len".
5453  * If "idx" is negative count from the end, -1 is the last character.
5454  * When going over the start return -1.
5455  */
5456     static long
5457 char_idx2byte(char_u *str, size_t str_len, varnumber_T idx)
5458 {
5459     varnumber_T nchar = idx;
5460     size_t	nbyte = 0;
5461 
5462     if (nchar >= 0)
5463     {
5464 	while (nchar > 0 && nbyte < str_len)
5465 	{
5466 	    nbyte += MB_CPTR2LEN(str + nbyte);
5467 	    --nchar;
5468 	}
5469     }
5470     else
5471     {
5472 	nbyte = str_len;
5473 	while (nchar < 0 && nbyte > 0)
5474 	{
5475 	    --nbyte;
5476 	    nbyte -= mb_head_off(str, str + nbyte);
5477 	    ++nchar;
5478 	}
5479 	if (nchar < 0)
5480 	    return -1;
5481     }
5482     return (long)nbyte;
5483 }
5484 
5485 /*
5486  * Return the slice "str[first:last]" using character indexes.
5487  * Return NULL when the result is empty.
5488  */
5489     char_u *
5490 string_slice(char_u *str, varnumber_T first, varnumber_T last)
5491 {
5492     long	start_byte, end_byte;
5493     size_t	slen;
5494 
5495     if (str == NULL)
5496 	return NULL;
5497     slen = STRLEN(str);
5498     start_byte = char_idx2byte(str, slen, first);
5499     if (start_byte < 0)
5500 	start_byte = 0; // first index very negative: use zero
5501     if (last == -1)
5502 	end_byte = (long)slen;
5503     else
5504     {
5505 	end_byte = char_idx2byte(str, slen, last);
5506 	if (end_byte >= 0 && end_byte < (long)slen)
5507 	    // end index is inclusive
5508 	    end_byte += MB_CPTR2LEN(str + end_byte);
5509     }
5510 
5511     if (start_byte >= (long)slen || end_byte <= start_byte)
5512 	return NULL;
5513     return vim_strnsave(str + start_byte, end_byte - start_byte);
5514 }
5515 
5516 /*
5517  * Handle:
5518  * - expr[expr], expr[expr:expr] subscript
5519  * - ".name" lookup
5520  * - function call with Funcref variable: func(expr)
5521  * - method call: var->method()
5522  *
5523  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5524  */
5525     int
5526 handle_subscript(
5527     char_u	**arg,
5528     typval_T	*rettv,
5529     evalarg_T	*evalarg,
5530     int		verbose)	// give error messages
5531 {
5532     int		evaluate = evalarg != NULL
5533 				      && (evalarg->eval_flags & EVAL_EVALUATE);
5534     int		ret = OK;
5535     dict_T	*selfdict = NULL;
5536     int		check_white = TRUE;
5537     int		getnext;
5538     char_u	*p;
5539 
5540     while (ret == OK)
5541     {
5542 	// When at the end of the line and ".name" or "->{" or "->X" follows in
5543 	// the next line then consume the line break.
5544 	p = eval_next_non_blank(*arg, evalarg, &getnext);
5545 	if (getnext
5546 	    && ((rettv->v_type == VAR_DICT && *p == '.' && eval_isdictc(p[1]))
5547 		|| (p[0] == '-' && p[1] == '>'
5548 				     && (p[2] == '{' || ASCII_ISALPHA(p[2])))))
5549 	{
5550 	    *arg = eval_next_line(evalarg);
5551 	    p = *arg;
5552 	    check_white = FALSE;
5553 	}
5554 
5555 	if ((**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5556 			    || rettv->v_type == VAR_PARTIAL))
5557 		    && (!check_white || !VIM_ISWHITE(*(*arg - 1))))
5558 	{
5559 	    ret = call_func_rettv(arg, evalarg, rettv, evaluate,
5560 							       selfdict, NULL);
5561 
5562 	    // Stop the expression evaluation when immediately aborting on
5563 	    // error, or when an interrupt occurred or an exception was thrown
5564 	    // but not caught.
5565 	    if (aborting())
5566 	    {
5567 		if (ret == OK)
5568 		    clear_tv(rettv);
5569 		ret = FAIL;
5570 	    }
5571 	    dict_unref(selfdict);
5572 	    selfdict = NULL;
5573 	}
5574 	else if (p[0] == '-' && p[1] == '>')
5575 	{
5576 	    *arg = p;
5577 	    if (ret == OK)
5578 	    {
5579 		if ((*arg)[2] == '{')
5580 		    // expr->{lambda}()
5581 		    ret = eval_lambda(arg, rettv, evalarg, verbose);
5582 		else
5583 		    // expr->name()
5584 		    ret = eval_method(arg, rettv, evalarg, verbose);
5585 	    }
5586 	}
5587 	// "." is ".name" lookup when we found a dict or when evaluating and
5588 	// scriptversion is at least 2, where string concatenation is "..".
5589 	else if (**arg == '['
5590 		|| (**arg == '.' && (rettv->v_type == VAR_DICT
5591 			|| (!evaluate
5592 			    && (*arg)[1] != '.'
5593 			    && current_sctx.sc_version >= 2))))
5594 	{
5595 	    dict_unref(selfdict);
5596 	    if (rettv->v_type == VAR_DICT)
5597 	    {
5598 		selfdict = rettv->vval.v_dict;
5599 		if (selfdict != NULL)
5600 		    ++selfdict->dv_refcount;
5601 	    }
5602 	    else
5603 		selfdict = NULL;
5604 	    if (eval_index(arg, rettv, evalarg, verbose) == FAIL)
5605 	    {
5606 		clear_tv(rettv);
5607 		ret = FAIL;
5608 	    }
5609 	}
5610 	else
5611 	    break;
5612     }
5613 
5614     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5615     // Don't do this when "Func" is already a partial that was bound
5616     // explicitly (pt_auto is FALSE).
5617     if (selfdict != NULL
5618 	    && (rettv->v_type == VAR_FUNC
5619 		|| (rettv->v_type == VAR_PARTIAL
5620 		    && (rettv->vval.v_partial->pt_auto
5621 			|| rettv->vval.v_partial->pt_dict == NULL))))
5622 	selfdict = make_partial(selfdict, rettv);
5623 
5624     dict_unref(selfdict);
5625     return ret;
5626 }
5627 
5628 /*
5629  * Make a copy of an item.
5630  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5631  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5632  * reference to an already copied list/dict can be used.
5633  * Returns FAIL or OK.
5634  */
5635     int
5636 item_copy(
5637     typval_T	*from,
5638     typval_T	*to,
5639     int		deep,
5640     int		copyID)
5641 {
5642     static int	recurse = 0;
5643     int		ret = OK;
5644 
5645     if (recurse >= DICT_MAXNEST)
5646     {
5647 	emsg(_("E698: variable nested too deep for making a copy"));
5648 	return FAIL;
5649     }
5650     ++recurse;
5651 
5652     switch (from->v_type)
5653     {
5654 	case VAR_NUMBER:
5655 	case VAR_FLOAT:
5656 	case VAR_STRING:
5657 	case VAR_FUNC:
5658 	case VAR_PARTIAL:
5659 	case VAR_BOOL:
5660 	case VAR_SPECIAL:
5661 	case VAR_JOB:
5662 	case VAR_CHANNEL:
5663 	    copy_tv(from, to);
5664 	    break;
5665 	case VAR_LIST:
5666 	    to->v_type = VAR_LIST;
5667 	    to->v_lock = 0;
5668 	    if (from->vval.v_list == NULL)
5669 		to->vval.v_list = NULL;
5670 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
5671 	    {
5672 		// use the copy made earlier
5673 		to->vval.v_list = from->vval.v_list->lv_copylist;
5674 		++to->vval.v_list->lv_refcount;
5675 	    }
5676 	    else
5677 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
5678 	    if (to->vval.v_list == NULL)
5679 		ret = FAIL;
5680 	    break;
5681 	case VAR_BLOB:
5682 	    ret = blob_copy(from->vval.v_blob, to);
5683 	    break;
5684 	case VAR_DICT:
5685 	    to->v_type = VAR_DICT;
5686 	    to->v_lock = 0;
5687 	    if (from->vval.v_dict == NULL)
5688 		to->vval.v_dict = NULL;
5689 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
5690 	    {
5691 		// use the copy made earlier
5692 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
5693 		++to->vval.v_dict->dv_refcount;
5694 	    }
5695 	    else
5696 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
5697 	    if (to->vval.v_dict == NULL)
5698 		ret = FAIL;
5699 	    break;
5700 	case VAR_UNKNOWN:
5701 	case VAR_ANY:
5702 	case VAR_VOID:
5703 	    internal_error_no_abort("item_copy(UNKNOWN)");
5704 	    ret = FAIL;
5705     }
5706     --recurse;
5707     return ret;
5708 }
5709 
5710     void
5711 echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr)
5712 {
5713     char_u	*tofree;
5714     char_u	numbuf[NUMBUFLEN];
5715     char_u	*p = echo_string(rettv, &tofree, numbuf, get_copyID());
5716 
5717     if (*atstart)
5718     {
5719 	*atstart = FALSE;
5720 	// Call msg_start() after eval1(), evaluating the expression
5721 	// may cause a message to appear.
5722 	if (with_space)
5723 	{
5724 	    // Mark the saved text as finishing the line, so that what
5725 	    // follows is displayed on a new line when scrolling back
5726 	    // at the more prompt.
5727 	    msg_sb_eol();
5728 	    msg_start();
5729 	}
5730     }
5731     else if (with_space)
5732 	msg_puts_attr(" ", echo_attr);
5733 
5734     if (p != NULL)
5735 	for ( ; *p != NUL && !got_int; ++p)
5736 	{
5737 	    if (*p == '\n' || *p == '\r' || *p == TAB)
5738 	    {
5739 		if (*p != TAB && *needclr)
5740 		{
5741 		    // remove any text still there from the command
5742 		    msg_clr_eos();
5743 		    *needclr = FALSE;
5744 		}
5745 		msg_putchar_attr(*p, echo_attr);
5746 	    }
5747 	    else
5748 	    {
5749 		if (has_mbyte)
5750 		{
5751 		    int i = (*mb_ptr2len)(p);
5752 
5753 		    (void)msg_outtrans_len_attr(p, i, echo_attr);
5754 		    p += i - 1;
5755 		}
5756 		else
5757 		    (void)msg_outtrans_len_attr(p, 1, echo_attr);
5758 	    }
5759 	}
5760     vim_free(tofree);
5761 }
5762 
5763 /*
5764  * ":echo expr1 ..."	print each argument separated with a space, add a
5765  *			newline at the end.
5766  * ":echon expr1 ..."	print each argument plain.
5767  */
5768     void
5769 ex_echo(exarg_T *eap)
5770 {
5771     char_u	*arg = eap->arg;
5772     typval_T	rettv;
5773     char_u	*p;
5774     int		needclr = TRUE;
5775     int		atstart = TRUE;
5776     int		did_emsg_before = did_emsg;
5777     int		called_emsg_before = called_emsg;
5778     evalarg_T	evalarg;
5779 
5780     fill_evalarg_from_eap(&evalarg, eap, eap->skip);
5781 
5782     if (eap->skip)
5783 	++emsg_skip;
5784     while ((!ends_excmd2(eap->cmd, arg) || *arg == '"') && !got_int)
5785     {
5786 	// If eval1() causes an error message the text from the command may
5787 	// still need to be cleared. E.g., "echo 22,44".
5788 	need_clr_eos = needclr;
5789 
5790 	p = arg;
5791 	if (eval1(&arg, &rettv, &evalarg) == FAIL)
5792 	{
5793 	    /*
5794 	     * Report the invalid expression unless the expression evaluation
5795 	     * has been cancelled due to an aborting error, an interrupt, or an
5796 	     * exception.
5797 	     */
5798 	    if (!aborting() && did_emsg == did_emsg_before
5799 					  && called_emsg == called_emsg_before)
5800 		semsg(_(e_invexpr2), p);
5801 	    need_clr_eos = FALSE;
5802 	    break;
5803 	}
5804 	need_clr_eos = FALSE;
5805 
5806 	if (!eap->skip)
5807 	    echo_one(&rettv, eap->cmdidx == CMD_echo, &atstart, &needclr);
5808 
5809 	clear_tv(&rettv);
5810 	arg = skipwhite(arg);
5811     }
5812     eap->nextcmd = check_nextcmd(arg);
5813     clear_evalarg(&evalarg, eap);
5814 
5815     if (eap->skip)
5816 	--emsg_skip;
5817     else
5818     {
5819 	// remove text that may still be there from the command
5820 	if (needclr)
5821 	    msg_clr_eos();
5822 	if (eap->cmdidx == CMD_echo)
5823 	    msg_end();
5824     }
5825 }
5826 
5827 /*
5828  * ":echohl {name}".
5829  */
5830     void
5831 ex_echohl(exarg_T *eap)
5832 {
5833     echo_attr = syn_name2attr(eap->arg);
5834 }
5835 
5836 /*
5837  * Returns the :echo attribute
5838  */
5839     int
5840 get_echo_attr(void)
5841 {
5842     return echo_attr;
5843 }
5844 
5845 /*
5846  * ":execute expr1 ..."	execute the result of an expression.
5847  * ":echomsg expr1 ..."	Print a message
5848  * ":echoerr expr1 ..."	Print an error
5849  * Each gets spaces around each argument and a newline at the end for
5850  * echo commands
5851  */
5852     void
5853 ex_execute(exarg_T *eap)
5854 {
5855     char_u	*arg = eap->arg;
5856     typval_T	rettv;
5857     int		ret = OK;
5858     char_u	*p;
5859     garray_T	ga;
5860     int		len;
5861 
5862     ga_init2(&ga, 1, 80);
5863 
5864     if (eap->skip)
5865 	++emsg_skip;
5866     while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
5867     {
5868 	ret = eval1_emsg(&arg, &rettv, eap);
5869 	if (ret == FAIL)
5870 	    break;
5871 
5872 	if (!eap->skip)
5873 	{
5874 	    char_u   buf[NUMBUFLEN];
5875 
5876 	    if (eap->cmdidx == CMD_execute)
5877 	    {
5878 		if (rettv.v_type == VAR_CHANNEL || rettv.v_type == VAR_JOB)
5879 		{
5880 		    emsg(_(e_inval_string));
5881 		    p = NULL;
5882 		}
5883 		else
5884 		    p = tv_get_string_buf(&rettv, buf);
5885 	    }
5886 	    else
5887 		p = tv_stringify(&rettv, buf);
5888 	    if (p == NULL)
5889 	    {
5890 		clear_tv(&rettv);
5891 		ret = FAIL;
5892 		break;
5893 	    }
5894 	    len = (int)STRLEN(p);
5895 	    if (ga_grow(&ga, len + 2) == FAIL)
5896 	    {
5897 		clear_tv(&rettv);
5898 		ret = FAIL;
5899 		break;
5900 	    }
5901 	    if (ga.ga_len)
5902 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
5903 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
5904 	    ga.ga_len += len;
5905 	}
5906 
5907 	clear_tv(&rettv);
5908 	arg = skipwhite(arg);
5909     }
5910 
5911     if (ret != FAIL && ga.ga_data != NULL)
5912     {
5913 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
5914 	{
5915 	    // Mark the already saved text as finishing the line, so that what
5916 	    // follows is displayed on a new line when scrolling back at the
5917 	    // more prompt.
5918 	    msg_sb_eol();
5919 	}
5920 
5921 	if (eap->cmdidx == CMD_echomsg)
5922 	{
5923 	    msg_attr(ga.ga_data, echo_attr);
5924 	    out_flush();
5925 	}
5926 	else if (eap->cmdidx == CMD_echoerr)
5927 	{
5928 	    int		save_did_emsg = did_emsg;
5929 
5930 	    // We don't want to abort following commands, restore did_emsg.
5931 	    emsg(ga.ga_data);
5932 	    if (!force_abort)
5933 		did_emsg = save_did_emsg;
5934 	}
5935 	else if (eap->cmdidx == CMD_execute)
5936 	    do_cmdline((char_u *)ga.ga_data,
5937 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
5938     }
5939 
5940     ga_clear(&ga);
5941 
5942     if (eap->skip)
5943 	--emsg_skip;
5944 
5945     eap->nextcmd = check_nextcmd(arg);
5946 }
5947 
5948 /*
5949  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
5950  * "arg" points to the "&" or '+' when called, to "option" when returning.
5951  * Returns NULL when no option name found.  Otherwise pointer to the char
5952  * after the option name.
5953  */
5954     char_u *
5955 find_option_end(char_u **arg, int *opt_flags)
5956 {
5957     char_u	*p = *arg;
5958 
5959     ++p;
5960     if (*p == 'g' && p[1] == ':')
5961     {
5962 	*opt_flags = OPT_GLOBAL;
5963 	p += 2;
5964     }
5965     else if (*p == 'l' && p[1] == ':')
5966     {
5967 	*opt_flags = OPT_LOCAL;
5968 	p += 2;
5969     }
5970     else
5971 	*opt_flags = 0;
5972 
5973     if (!ASCII_ISALPHA(*p))
5974 	return NULL;
5975     *arg = p;
5976 
5977     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
5978 	p += 4;	    // termcap option
5979     else
5980 	while (ASCII_ISALPHA(*p))
5981 	    ++p;
5982     return p;
5983 }
5984 
5985 /*
5986  * Display script name where an item was last set.
5987  * Should only be invoked when 'verbose' is non-zero.
5988  */
5989     void
5990 last_set_msg(sctx_T script_ctx)
5991 {
5992     char_u *p;
5993 
5994     if (script_ctx.sc_sid != 0)
5995     {
5996 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
5997 	if (p != NULL)
5998 	{
5999 	    verbose_enter();
6000 	    msg_puts(_("\n\tLast set from "));
6001 	    msg_puts((char *)p);
6002 	    if (script_ctx.sc_lnum > 0)
6003 	    {
6004 		msg_puts(_(line_msg));
6005 		msg_outnum((long)script_ctx.sc_lnum);
6006 	    }
6007 	    verbose_leave();
6008 	    vim_free(p);
6009 	}
6010     }
6011 }
6012 
6013 #endif // FEAT_EVAL
6014 
6015 /*
6016  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
6017  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
6018  * "flags" can be "g" to do a global substitute.
6019  * Returns an allocated string, NULL for error.
6020  */
6021     char_u *
6022 do_string_sub(
6023     char_u	*str,
6024     char_u	*pat,
6025     char_u	*sub,
6026     typval_T	*expr,
6027     char_u	*flags)
6028 {
6029     int		sublen;
6030     regmatch_T	regmatch;
6031     int		i;
6032     int		do_all;
6033     char_u	*tail;
6034     char_u	*end;
6035     garray_T	ga;
6036     char_u	*ret;
6037     char_u	*save_cpo;
6038     char_u	*zero_width = NULL;
6039 
6040     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
6041     save_cpo = p_cpo;
6042     p_cpo = empty_option;
6043 
6044     ga_init2(&ga, 1, 200);
6045 
6046     do_all = (flags[0] == 'g');
6047 
6048     regmatch.rm_ic = p_ic;
6049     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
6050     if (regmatch.regprog != NULL)
6051     {
6052 	tail = str;
6053 	end = str + STRLEN(str);
6054 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
6055 	{
6056 	    // Skip empty match except for first match.
6057 	    if (regmatch.startp[0] == regmatch.endp[0])
6058 	    {
6059 		if (zero_width == regmatch.startp[0])
6060 		{
6061 		    // avoid getting stuck on a match with an empty string
6062 		    i = mb_ptr2len(tail);
6063 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
6064 								   (size_t)i);
6065 		    ga.ga_len += i;
6066 		    tail += i;
6067 		    continue;
6068 		}
6069 		zero_width = regmatch.startp[0];
6070 	    }
6071 
6072 	    /*
6073 	     * Get some space for a temporary buffer to do the substitution
6074 	     * into.  It will contain:
6075 	     * - The text up to where the match is.
6076 	     * - The substituted text.
6077 	     * - The text after the match.
6078 	     */
6079 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
6080 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
6081 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
6082 	    {
6083 		ga_clear(&ga);
6084 		break;
6085 	    }
6086 
6087 	    // copy the text up to where the match is
6088 	    i = (int)(regmatch.startp[0] - tail);
6089 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
6090 	    // add the substituted text
6091 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
6092 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
6093 	    ga.ga_len += i + sublen - 1;
6094 	    tail = regmatch.endp[0];
6095 	    if (*tail == NUL)
6096 		break;
6097 	    if (!do_all)
6098 		break;
6099 	}
6100 
6101 	if (ga.ga_data != NULL)
6102 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
6103 
6104 	vim_regfree(regmatch.regprog);
6105     }
6106 
6107     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
6108     ga_clear(&ga);
6109     if (p_cpo == empty_option)
6110 	p_cpo = save_cpo;
6111     else
6112 	// Darn, evaluating {sub} expression or {expr} changed the value.
6113 	free_string_option(save_cpo);
6114 
6115     return ret;
6116 }
6117