xref: /vim-8.2.3635/src/eval.c (revision 8ea05de6)
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 
2160 	// Some of the expression may not have been consumed.  Do not check for
2161 	// a next command to avoid more errors, unless "|" is following, which
2162 	// could only be a command separator.
2163 	if (eap != NULL && skipwhite(p)[0] == '|' && skipwhite(p)[1] != '|')
2164 	    eap->nextcmd = check_nextcmd(p);
2165 	return FAIL;
2166     }
2167 
2168     if (eap != NULL)
2169 	eap->nextcmd = check_nextcmd(p);
2170 
2171     return ret;
2172 }
2173 
2174 /*
2175  * Handle top level expression:
2176  *	expr2 ? expr1 : expr1
2177  *	expr2 ?? expr1
2178  *
2179  * "arg" must point to the first non-white of the expression.
2180  * "arg" is advanced to just after the recognized expression.
2181  *
2182  * Note: "rettv.v_lock" is not set.
2183  *
2184  * Return OK or FAIL.
2185  */
2186     int
2187 eval1(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2188 {
2189     char_u  *p;
2190     int	    getnext;
2191 
2192     CLEAR_POINTER(rettv);
2193 
2194     /*
2195      * Get the first variable.
2196      */
2197     if (eval2(arg, rettv, evalarg) == FAIL)
2198 	return FAIL;
2199 
2200     p = eval_next_non_blank(*arg, evalarg, &getnext);
2201     if (*p == '?')
2202     {
2203 	int		op_falsy = p[1] == '?';
2204 	int		result;
2205 	typval_T	var2;
2206 	evalarg_T	*evalarg_used = evalarg;
2207 	evalarg_T	local_evalarg;
2208 	int		orig_flags;
2209 	int		evaluate;
2210 	int		vim9script = in_vim9script();
2211 
2212 	if (evalarg == NULL)
2213 	{
2214 	    CLEAR_FIELD(local_evalarg);
2215 	    evalarg_used = &local_evalarg;
2216 	}
2217 	orig_flags = evalarg_used->eval_flags;
2218 	evaluate = evalarg_used->eval_flags & EVAL_EVALUATE;
2219 
2220 	if (getnext)
2221 	    *arg = eval_next_line(evalarg_used);
2222 	else
2223 	{
2224 	    if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2225 	    {
2226 		error_white_both(p, 1);
2227 		clear_tv(rettv);
2228 		return FAIL;
2229 	    }
2230 	    *arg = p;
2231 	}
2232 
2233 	result = FALSE;
2234 	if (evaluate)
2235 	{
2236 	    int		error = FALSE;
2237 
2238 	    if (op_falsy)
2239 		result = tv2bool(rettv);
2240 	    else if (vim9script)
2241 		result = tv_get_bool_chk(rettv, &error);
2242 	    else if (tv_get_number_chk(rettv, &error) != 0)
2243 		result = TRUE;
2244 	    if (error || !op_falsy || !result)
2245 		clear_tv(rettv);
2246 	    if (error)
2247 		return FAIL;
2248 	}
2249 
2250 	/*
2251 	 * Get the second variable.  Recursive!
2252 	 */
2253 	if (op_falsy)
2254 	    ++*arg;
2255 	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[1]))
2256 	{
2257 	    error_white_both(p, 1);
2258 	    clear_tv(rettv);
2259 	    return FAIL;
2260 	}
2261 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2262 	evalarg_used->eval_flags = (op_falsy ? !result : result)
2263 				    ? orig_flags : orig_flags & ~EVAL_EVALUATE;
2264 	if (eval1(arg, &var2, evalarg_used) == FAIL)
2265 	{
2266 	    evalarg_used->eval_flags = orig_flags;
2267 	    return FAIL;
2268 	}
2269 	if (!op_falsy || !result)
2270 	    *rettv = var2;
2271 
2272 	if (!op_falsy)
2273 	{
2274 	    /*
2275 	     * Check for the ":".
2276 	     */
2277 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2278 	    if (*p != ':')
2279 	    {
2280 		emsg(_(e_missing_colon));
2281 		if (evaluate && result)
2282 		    clear_tv(rettv);
2283 		evalarg_used->eval_flags = orig_flags;
2284 		return FAIL;
2285 	    }
2286 	    if (getnext)
2287 		*arg = eval_next_line(evalarg_used);
2288 	    else
2289 	    {
2290 		if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2291 		{
2292 		    error_white_both(p, 1);
2293 		    clear_tv(rettv);
2294 		    evalarg_used->eval_flags = orig_flags;
2295 		    return FAIL;
2296 		}
2297 		*arg = p;
2298 	    }
2299 
2300 	    /*
2301 	     * Get the third variable.  Recursive!
2302 	     */
2303 	    if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[1]))
2304 	    {
2305 		error_white_both(p, 1);
2306 		clear_tv(rettv);
2307 		evalarg_used->eval_flags = orig_flags;
2308 		return FAIL;
2309 	    }
2310 	    *arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2311 	    evalarg_used->eval_flags = !result ? orig_flags
2312 						 : orig_flags & ~EVAL_EVALUATE;
2313 	    if (eval1(arg, &var2, evalarg_used) == FAIL)
2314 	    {
2315 		if (evaluate && result)
2316 		    clear_tv(rettv);
2317 		evalarg_used->eval_flags = orig_flags;
2318 		return FAIL;
2319 	    }
2320 	    if (evaluate && !result)
2321 		*rettv = var2;
2322 	}
2323 
2324 	if (evalarg == NULL)
2325 	    clear_evalarg(&local_evalarg, NULL);
2326 	else
2327 	    evalarg->eval_flags = orig_flags;
2328     }
2329 
2330     return OK;
2331 }
2332 
2333 /*
2334  * Handle first level expression:
2335  *	expr2 || expr2 || expr2	    logical OR
2336  *
2337  * "arg" must point to the first non-white of the expression.
2338  * "arg" is advanced to just after the recognized expression.
2339  *
2340  * Return OK or FAIL.
2341  */
2342     static int
2343 eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2344 {
2345     char_u	*p;
2346     int		getnext;
2347 
2348     /*
2349      * Get the first variable.
2350      */
2351     if (eval3(arg, rettv, evalarg) == FAIL)
2352 	return FAIL;
2353 
2354     /*
2355      * Handle the  "||" operator.
2356      */
2357     p = eval_next_non_blank(*arg, evalarg, &getnext);
2358     if (p[0] == '|' && p[1] == '|')
2359     {
2360 	evalarg_T   *evalarg_used = evalarg;
2361 	evalarg_T   local_evalarg;
2362 	int	    evaluate;
2363 	int	    orig_flags;
2364 	long	    result = FALSE;
2365 	typval_T    var2;
2366 	int	    error = FALSE;
2367 	int	    vim9script = in_vim9script();
2368 
2369 	if (evalarg == NULL)
2370 	{
2371 	    CLEAR_FIELD(local_evalarg);
2372 	    evalarg_used = &local_evalarg;
2373 	}
2374 	orig_flags = evalarg_used->eval_flags;
2375 	evaluate = orig_flags & EVAL_EVALUATE;
2376 	if (evaluate)
2377 	{
2378 	    if (vim9script)
2379 		result = tv_get_bool_chk(rettv, &error);
2380 	    else if (tv_get_number_chk(rettv, &error) != 0)
2381 		result = TRUE;
2382 	    clear_tv(rettv);
2383 	    if (error)
2384 		return FAIL;
2385 	}
2386 
2387 	/*
2388 	 * Repeat until there is no following "||".
2389 	 */
2390 	while (p[0] == '|' && p[1] == '|')
2391 	{
2392 	    if (getnext)
2393 		*arg = eval_next_line(evalarg_used);
2394 	    else
2395 	    {
2396 		if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2397 		{
2398 		    error_white_both(p, 2);
2399 		    clear_tv(rettv);
2400 		    return FAIL;
2401 		}
2402 		*arg = p;
2403 	    }
2404 
2405 	    /*
2406 	     * Get the second variable.
2407 	     */
2408 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2409 	    {
2410 		error_white_both(p, 2);
2411 		clear_tv(rettv);
2412 		return FAIL;
2413 	    }
2414 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2415 	    evalarg_used->eval_flags = !result ? orig_flags
2416 						 : orig_flags & ~EVAL_EVALUATE;
2417 	    if (eval3(arg, &var2, evalarg_used) == FAIL)
2418 		return FAIL;
2419 
2420 	    /*
2421 	     * Compute the result.
2422 	     */
2423 	    if (evaluate && !result)
2424 	    {
2425 		if (vim9script)
2426 		    result = tv_get_bool_chk(&var2, &error);
2427 		else if (tv_get_number_chk(&var2, &error) != 0)
2428 		    result = TRUE;
2429 		clear_tv(&var2);
2430 		if (error)
2431 		    return FAIL;
2432 	    }
2433 	    if (evaluate)
2434 	    {
2435 		if (vim9script)
2436 		{
2437 		    rettv->v_type = VAR_BOOL;
2438 		    rettv->vval.v_number = result ? VVAL_TRUE : VVAL_FALSE;
2439 		}
2440 		else
2441 		{
2442 		    rettv->v_type = VAR_NUMBER;
2443 		    rettv->vval.v_number = result;
2444 		}
2445 	    }
2446 
2447 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2448 	}
2449 
2450 	if (evalarg == NULL)
2451 	    clear_evalarg(&local_evalarg, NULL);
2452 	else
2453 	    evalarg->eval_flags = orig_flags;
2454     }
2455 
2456     return OK;
2457 }
2458 
2459 /*
2460  * Handle second level expression:
2461  *	expr3 && expr3 && expr3	    logical AND
2462  *
2463  * "arg" must point to the first non-white of the expression.
2464  * "arg" is advanced to just after the recognized expression.
2465  *
2466  * Return OK or FAIL.
2467  */
2468     static int
2469 eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2470 {
2471     char_u	*p;
2472     int		getnext;
2473 
2474     /*
2475      * Get the first variable.
2476      */
2477     if (eval4(arg, rettv, evalarg) == FAIL)
2478 	return FAIL;
2479 
2480     /*
2481      * Handle the "&&" operator.
2482      */
2483     p = eval_next_non_blank(*arg, evalarg, &getnext);
2484     if (p[0] == '&' && p[1] == '&')
2485     {
2486 	evalarg_T   *evalarg_used = evalarg;
2487 	evalarg_T   local_evalarg;
2488 	int	    orig_flags;
2489 	int	    evaluate;
2490 	long	    result = TRUE;
2491 	typval_T    var2;
2492 	int	    error = FALSE;
2493 	int	    vim9script = in_vim9script();
2494 
2495 	if (evalarg == NULL)
2496 	{
2497 	    CLEAR_FIELD(local_evalarg);
2498 	    evalarg_used = &local_evalarg;
2499 	}
2500 	orig_flags = evalarg_used->eval_flags;
2501 	evaluate = orig_flags & EVAL_EVALUATE;
2502 	if (evaluate)
2503 	{
2504 	    if (vim9script)
2505 		result = tv_get_bool_chk(rettv, &error);
2506 	    else if (tv_get_number_chk(rettv, &error) == 0)
2507 		result = FALSE;
2508 	    clear_tv(rettv);
2509 	    if (error)
2510 		return FAIL;
2511 	}
2512 
2513 	/*
2514 	 * Repeat until there is no following "&&".
2515 	 */
2516 	while (p[0] == '&' && p[1] == '&')
2517 	{
2518 	    if (getnext)
2519 		*arg = eval_next_line(evalarg_used);
2520 	    else
2521 	    {
2522 		if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2523 		{
2524 		    error_white_both(p, 2);
2525 		    clear_tv(rettv);
2526 		    return FAIL;
2527 		}
2528 		*arg = p;
2529 	    }
2530 
2531 	    /*
2532 	     * Get the second variable.
2533 	     */
2534 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2535 	    {
2536 		error_white_both(p, 2);
2537 		clear_tv(rettv);
2538 		return FAIL;
2539 	    }
2540 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2541 	    evalarg_used->eval_flags = result ? orig_flags
2542 						 : orig_flags & ~EVAL_EVALUATE;
2543 	    CLEAR_FIELD(var2);
2544 	    if (eval4(arg, &var2, evalarg_used) == FAIL)
2545 		return FAIL;
2546 
2547 	    /*
2548 	     * Compute the result.
2549 	     */
2550 	    if (evaluate && result)
2551 	    {
2552 		if (vim9script)
2553 		    result = tv_get_bool_chk(&var2, &error);
2554 		else if (tv_get_number_chk(&var2, &error) == 0)
2555 		    result = FALSE;
2556 		clear_tv(&var2);
2557 		if (error)
2558 		    return FAIL;
2559 	    }
2560 	    if (evaluate)
2561 	    {
2562 		if (vim9script)
2563 		{
2564 		    rettv->v_type = VAR_BOOL;
2565 		    rettv->vval.v_number = result ? VVAL_TRUE : VVAL_FALSE;
2566 		}
2567 		else
2568 		{
2569 		    rettv->v_type = VAR_NUMBER;
2570 		    rettv->vval.v_number = result;
2571 		}
2572 	    }
2573 
2574 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2575 	}
2576 
2577 	if (evalarg == NULL)
2578 	    clear_evalarg(&local_evalarg, NULL);
2579 	else
2580 	    evalarg->eval_flags = orig_flags;
2581     }
2582 
2583     return OK;
2584 }
2585 
2586 /*
2587  * Handle third level expression:
2588  *	var1 == var2
2589  *	var1 =~ var2
2590  *	var1 != var2
2591  *	var1 !~ var2
2592  *	var1 > var2
2593  *	var1 >= var2
2594  *	var1 < var2
2595  *	var1 <= var2
2596  *	var1 is var2
2597  *	var1 isnot var2
2598  *
2599  * "arg" must point to the first non-white of the expression.
2600  * "arg" is advanced to just after the recognized expression.
2601  *
2602  * Return OK or FAIL.
2603  */
2604     static int
2605 eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2606 {
2607     char_u	*p;
2608     int		getnext;
2609     exptype_T	type = EXPR_UNKNOWN;
2610     int		len = 2;
2611     int		type_is = FALSE;
2612 
2613     /*
2614      * Get the first variable.
2615      */
2616     if (eval5(arg, rettv, evalarg) == FAIL)
2617 	return FAIL;
2618 
2619     p = eval_next_non_blank(*arg, evalarg, &getnext);
2620     type = get_compare_type(p, &len, &type_is);
2621 
2622     /*
2623      * If there is a comparative operator, use it.
2624      */
2625     if (type != EXPR_UNKNOWN)
2626     {
2627 	typval_T    var2;
2628 	int	    ic;
2629 	int	    vim9script = in_vim9script();
2630 	int	    evaluate = evalarg == NULL
2631 				   ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2632 
2633 	if (getnext)
2634 	    *arg = eval_next_line(evalarg);
2635 	else if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2636 	{
2637 	    error_white_both(p, len);
2638 	    clear_tv(rettv);
2639 	    return FAIL;
2640 	}
2641 
2642 	if (vim9script && type_is && (p[len] == '?' || p[len] == '#'))
2643 	{
2644 	    semsg(_(e_invexpr2), p);
2645 	    clear_tv(rettv);
2646 	    return FAIL;
2647 	}
2648 
2649 	// extra question mark appended: ignore case
2650 	if (p[len] == '?')
2651 	{
2652 	    ic = TRUE;
2653 	    ++len;
2654 	}
2655 	// extra '#' appended: match case
2656 	else if (p[len] == '#')
2657 	{
2658 	    ic = FALSE;
2659 	    ++len;
2660 	}
2661 	// nothing appended: use 'ignorecase' if not in Vim script
2662 	else
2663 	    ic = vim9script ? FALSE : p_ic;
2664 
2665 	/*
2666 	 * Get the second variable.
2667 	 */
2668 	if (evaluate && vim9script && !IS_WHITE_OR_NUL(p[len]))
2669 	{
2670 	    error_white_both(p, 1);
2671 	    clear_tv(rettv);
2672 	    return FAIL;
2673 	}
2674 	*arg = skipwhite_and_linebreak(p + len, evalarg);
2675 	if (eval5(arg, &var2, evalarg) == FAIL)
2676 	{
2677 	    clear_tv(rettv);
2678 	    return FAIL;
2679 	}
2680 	if (evaluate)
2681 	{
2682 	    int ret;
2683 
2684 	    if (vim9script && check_compare_types(type, rettv, &var2) == FAIL)
2685 	    {
2686 		ret = FAIL;
2687 		clear_tv(rettv);
2688 	    }
2689 	    else
2690 		ret = typval_compare(rettv, &var2, type, ic);
2691 	    clear_tv(&var2);
2692 	    return ret;
2693 	}
2694     }
2695 
2696     return OK;
2697 }
2698 
2699 /*
2700  * Make a copy of blob "tv1" and append blob "tv2".
2701  */
2702     void
2703 eval_addblob(typval_T *tv1, typval_T *tv2)
2704 {
2705     blob_T  *b1 = tv1->vval.v_blob;
2706     blob_T  *b2 = tv2->vval.v_blob;
2707     blob_T  *b = blob_alloc();
2708     int	    i;
2709 
2710     if (b != NULL)
2711     {
2712 	for (i = 0; i < blob_len(b1); i++)
2713 	    ga_append(&b->bv_ga, blob_get(b1, i));
2714 	for (i = 0; i < blob_len(b2); i++)
2715 	    ga_append(&b->bv_ga, blob_get(b2, i));
2716 
2717 	clear_tv(tv1);
2718 	rettv_blob_set(tv1, b);
2719     }
2720 }
2721 
2722 /*
2723  * Make a copy of list "tv1" and append list "tv2".
2724  */
2725     int
2726 eval_addlist(typval_T *tv1, typval_T *tv2)
2727 {
2728     typval_T var3;
2729 
2730     // concatenate Lists
2731     if (list_concat(tv1->vval.v_list, tv2->vval.v_list, &var3) == FAIL)
2732     {
2733 	clear_tv(tv1);
2734 	clear_tv(tv2);
2735 	return FAIL;
2736     }
2737     clear_tv(tv1);
2738     *tv1 = var3;
2739     return OK;
2740 }
2741 
2742 /*
2743  * Handle fourth level expression:
2744  *	+	number addition
2745  *	-	number subtraction
2746  *	.	string concatenation (if script version is 1)
2747  *	..	string concatenation
2748  *
2749  * "arg" must point to the first non-white of the expression.
2750  * "arg" is advanced to just after the recognized expression.
2751  *
2752  * Return OK or FAIL.
2753  */
2754     static int
2755 eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2756 {
2757     /*
2758      * Get the first variable.
2759      */
2760     if (eval6(arg, rettv, evalarg, FALSE) == FAIL)
2761 	return FAIL;
2762 
2763     /*
2764      * Repeat computing, until no '+', '-' or '.' is following.
2765      */
2766     for (;;)
2767     {
2768 	int	    evaluate;
2769 	int	    getnext;
2770 	char_u	    *p;
2771 	int	    op;
2772 	int	    oplen;
2773 	int	    concat;
2774 	typval_T    var2;
2775 	int	    vim9script = in_vim9script();
2776 
2777 	// "." is only string concatenation when scriptversion is 1
2778 	// "+=" and "-=" are assignment
2779 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2780 	op = *p;
2781 	concat = op == '.' && (*(p + 1) == '.' || current_sctx.sc_version < 2);
2782 	if ((op != '+' && op != '-' && !concat) || p[1] == '=')
2783 	    break;
2784 
2785 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2786 	oplen = (concat && p[1] == '.') ? 2 : 1;
2787 	if (getnext)
2788 	    *arg = eval_next_line(evalarg);
2789 	else
2790 	{
2791 	    if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2792 	    {
2793 		error_white_both(p, oplen);
2794 		clear_tv(rettv);
2795 		return FAIL;
2796 	    }
2797 	    *arg = p;
2798 	}
2799 	if ((op != '+' || (rettv->v_type != VAR_LIST
2800 						 && rettv->v_type != VAR_BLOB))
2801 #ifdef FEAT_FLOAT
2802 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2803 #endif
2804 		&& evaluate)
2805 	{
2806 	    int		error = FALSE;
2807 
2808 	    // For "list + ...", an illegal use of the first operand as
2809 	    // a number cannot be determined before evaluating the 2nd
2810 	    // operand: if this is also a list, all is ok.
2811 	    // For "something . ...", "something - ..." or "non-list + ...",
2812 	    // we know that the first operand needs to be a string or number
2813 	    // without evaluating the 2nd operand.  So check before to avoid
2814 	    // side effects after an error.
2815 	    if (op != '.')
2816 		tv_get_number_chk(rettv, &error);
2817 	    if ((op == '.' && tv_get_string_chk(rettv) == NULL) || error)
2818 	    {
2819 		clear_tv(rettv);
2820 		return FAIL;
2821 	    }
2822 	}
2823 
2824 	/*
2825 	 * Get the second variable.
2826 	 */
2827 	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[oplen]))
2828 	{
2829 	    error_white_both(p, oplen);
2830 	    clear_tv(rettv);
2831 	    return FAIL;
2832 	}
2833 	*arg = skipwhite_and_linebreak(*arg + oplen, evalarg);
2834 	if (eval6(arg, &var2, evalarg, !vim9script && op == '.') == FAIL)
2835 	{
2836 	    clear_tv(rettv);
2837 	    return FAIL;
2838 	}
2839 
2840 	if (evaluate)
2841 	{
2842 	    /*
2843 	     * Compute the result.
2844 	     */
2845 	    if (op == '.')
2846 	    {
2847 		char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
2848 		char_u	*s1 = tv_get_string_buf(rettv, buf1);
2849 		char_u	*s2 = NULL;
2850 
2851 		if (vim9script && (var2.v_type == VAR_VOID
2852 			|| var2.v_type == VAR_CHANNEL
2853 			|| var2.v_type == VAR_JOB))
2854 		    emsg(_(e_inval_string));
2855 #ifdef FEAT_FLOAT
2856 		else if (vim9script && var2.v_type == VAR_FLOAT)
2857 		{
2858 		    vim_snprintf((char *)buf2, NUMBUFLEN, "%g",
2859 							    var2.vval.v_float);
2860 		    s2 = buf2;
2861 		}
2862 #endif
2863 		else
2864 		    s2 = tv_get_string_buf_chk(&var2, buf2);
2865 		if (s2 == NULL)		// type error ?
2866 		{
2867 		    clear_tv(rettv);
2868 		    clear_tv(&var2);
2869 		    return FAIL;
2870 		}
2871 		p = concat_str(s1, s2);
2872 		clear_tv(rettv);
2873 		rettv->v_type = VAR_STRING;
2874 		rettv->vval.v_string = p;
2875 	    }
2876 	    else if (op == '+' && rettv->v_type == VAR_BLOB
2877 						   && var2.v_type == VAR_BLOB)
2878 		eval_addblob(rettv, &var2);
2879 	    else if (op == '+' && rettv->v_type == VAR_LIST
2880 						   && var2.v_type == VAR_LIST)
2881 	    {
2882 		if (eval_addlist(rettv, &var2) == FAIL)
2883 		    return FAIL;
2884 	    }
2885 	    else
2886 	    {
2887 		int		error = FALSE;
2888 		varnumber_T	n1, n2;
2889 #ifdef FEAT_FLOAT
2890 		float_T	    f1 = 0, f2 = 0;
2891 
2892 		if (rettv->v_type == VAR_FLOAT)
2893 		{
2894 		    f1 = rettv->vval.v_float;
2895 		    n1 = 0;
2896 		}
2897 		else
2898 #endif
2899 		{
2900 		    n1 = tv_get_number_chk(rettv, &error);
2901 		    if (error)
2902 		    {
2903 			// This can only happen for "list + non-list".  For
2904 			// "non-list + ..." or "something - ...", we returned
2905 			// before evaluating the 2nd operand.
2906 			clear_tv(rettv);
2907 			return FAIL;
2908 		    }
2909 #ifdef FEAT_FLOAT
2910 		    if (var2.v_type == VAR_FLOAT)
2911 			f1 = n1;
2912 #endif
2913 		}
2914 #ifdef FEAT_FLOAT
2915 		if (var2.v_type == VAR_FLOAT)
2916 		{
2917 		    f2 = var2.vval.v_float;
2918 		    n2 = 0;
2919 		}
2920 		else
2921 #endif
2922 		{
2923 		    n2 = tv_get_number_chk(&var2, &error);
2924 		    if (error)
2925 		    {
2926 			clear_tv(rettv);
2927 			clear_tv(&var2);
2928 			return FAIL;
2929 		    }
2930 #ifdef FEAT_FLOAT
2931 		    if (rettv->v_type == VAR_FLOAT)
2932 			f2 = n2;
2933 #endif
2934 		}
2935 		clear_tv(rettv);
2936 
2937 #ifdef FEAT_FLOAT
2938 		// If there is a float on either side the result is a float.
2939 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
2940 		{
2941 		    if (op == '+')
2942 			f1 = f1 + f2;
2943 		    else
2944 			f1 = f1 - f2;
2945 		    rettv->v_type = VAR_FLOAT;
2946 		    rettv->vval.v_float = f1;
2947 		}
2948 		else
2949 #endif
2950 		{
2951 		    if (op == '+')
2952 			n1 = n1 + n2;
2953 		    else
2954 			n1 = n1 - n2;
2955 		    rettv->v_type = VAR_NUMBER;
2956 		    rettv->vval.v_number = n1;
2957 		}
2958 	    }
2959 	    clear_tv(&var2);
2960 	}
2961     }
2962     return OK;
2963 }
2964 
2965 /*
2966  * Handle fifth level expression:
2967  *	*	number multiplication
2968  *	/	number division
2969  *	%	number modulo
2970  *
2971  * "arg" must point to the first non-white of the expression.
2972  * "arg" is advanced to just after the recognized expression.
2973  *
2974  * Return OK or FAIL.
2975  */
2976     static int
2977 eval6(
2978     char_u	**arg,
2979     typval_T	*rettv,
2980     evalarg_T	*evalarg,
2981     int		want_string)  // after "." operator
2982 {
2983 #ifdef FEAT_FLOAT
2984     int	    use_float = FALSE;
2985 #endif
2986 
2987     /*
2988      * Get the first variable.
2989      */
2990     if (eval7(arg, rettv, evalarg, want_string) == FAIL)
2991 	return FAIL;
2992 
2993     /*
2994      * Repeat computing, until no '*', '/' or '%' is following.
2995      */
2996     for (;;)
2997     {
2998 	int	    evaluate;
2999 	int	    getnext;
3000 	typval_T    var2;
3001 	char_u	    *p;
3002 	int	    op;
3003 	varnumber_T n1, n2;
3004 #ifdef FEAT_FLOAT
3005 	float_T	    f1, f2;
3006 #endif
3007 	int	    error;
3008 
3009 	p = eval_next_non_blank(*arg, evalarg, &getnext);
3010 	op = *p;
3011 	if (op != '*' && op != '/' && op != '%')
3012 	    break;
3013 
3014 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
3015 	if (getnext)
3016 	    *arg = eval_next_line(evalarg);
3017 	else
3018 	{
3019 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(**arg))
3020 	    {
3021 		error_white_both(p, 1);
3022 		clear_tv(rettv);
3023 		return FAIL;
3024 	    }
3025 	    *arg = p;
3026 	}
3027 
3028 #ifdef FEAT_FLOAT
3029 	f1 = 0;
3030 	f2 = 0;
3031 #endif
3032 	error = FALSE;
3033 	if (evaluate)
3034 	{
3035 #ifdef FEAT_FLOAT
3036 	    if (rettv->v_type == VAR_FLOAT)
3037 	    {
3038 		f1 = rettv->vval.v_float;
3039 		use_float = TRUE;
3040 		n1 = 0;
3041 	    }
3042 	    else
3043 #endif
3044 		n1 = tv_get_number_chk(rettv, &error);
3045 	    clear_tv(rettv);
3046 	    if (error)
3047 		return FAIL;
3048 	}
3049 	else
3050 	    n1 = 0;
3051 
3052 	/*
3053 	 * Get the second variable.
3054 	 */
3055 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[1]))
3056 	{
3057 	    error_white_both(p, 1);
3058 	    clear_tv(rettv);
3059 	    return FAIL;
3060 	}
3061 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3062 	if (eval7(arg, &var2, evalarg, FALSE) == FAIL)
3063 	    return FAIL;
3064 
3065 	if (evaluate)
3066 	{
3067 #ifdef FEAT_FLOAT
3068 	    if (var2.v_type == VAR_FLOAT)
3069 	    {
3070 		if (!use_float)
3071 		{
3072 		    f1 = n1;
3073 		    use_float = TRUE;
3074 		}
3075 		f2 = var2.vval.v_float;
3076 		n2 = 0;
3077 	    }
3078 	    else
3079 #endif
3080 	    {
3081 		n2 = tv_get_number_chk(&var2, &error);
3082 		clear_tv(&var2);
3083 		if (error)
3084 		    return FAIL;
3085 #ifdef FEAT_FLOAT
3086 		if (use_float)
3087 		    f2 = n2;
3088 #endif
3089 	    }
3090 
3091 	    /*
3092 	     * Compute the result.
3093 	     * When either side is a float the result is a float.
3094 	     */
3095 #ifdef FEAT_FLOAT
3096 	    if (use_float)
3097 	    {
3098 		if (op == '*')
3099 		    f1 = f1 * f2;
3100 		else if (op == '/')
3101 		{
3102 # ifdef VMS
3103 		    // VMS crashes on divide by zero, work around it
3104 		    if (f2 == 0.0)
3105 		    {
3106 			if (f1 == 0)
3107 			    f1 = -1 * __F_FLT_MAX - 1L;   // similar to NaN
3108 			else if (f1 < 0)
3109 			    f1 = -1 * __F_FLT_MAX;
3110 			else
3111 			    f1 = __F_FLT_MAX;
3112 		    }
3113 		    else
3114 			f1 = f1 / f2;
3115 # else
3116 		    // We rely on the floating point library to handle divide
3117 		    // by zero to result in "inf" and not a crash.
3118 		    f1 = f1 / f2;
3119 # endif
3120 		}
3121 		else
3122 		{
3123 		    emsg(_(e_modulus));
3124 		    return FAIL;
3125 		}
3126 		rettv->v_type = VAR_FLOAT;
3127 		rettv->vval.v_float = f1;
3128 	    }
3129 	    else
3130 #endif
3131 	    {
3132 		if (op == '*')
3133 		    n1 = n1 * n2;
3134 		else if (op == '/')
3135 		    n1 = num_divide(n1, n2);
3136 		else
3137 		    n1 = num_modulus(n1, n2);
3138 
3139 		rettv->v_type = VAR_NUMBER;
3140 		rettv->vval.v_number = n1;
3141 	    }
3142 	}
3143     }
3144 
3145     return OK;
3146 }
3147 
3148 /*
3149  * Handle sixth level expression:
3150  *  number		number constant
3151  *  0zFFFFFFFF		Blob constant
3152  *  "string"		string constant
3153  *  'string'		literal string constant
3154  *  &option-name	option value
3155  *  @r			register contents
3156  *  identifier		variable value
3157  *  function()		function call
3158  *  $VAR		environment variable
3159  *  (expression)	nested expression
3160  *  [expr, expr]	List
3161  *  {arg, arg -> expr}	Lambda
3162  *  {key: val, key: val}   Dictionary
3163  *  #{key: val, key: val}  Dictionary with literal keys
3164  *
3165  *  Also handle:
3166  *  ! in front		logical NOT
3167  *  - in front		unary minus
3168  *  + in front		unary plus (ignored)
3169  *  trailing []		subscript in String or List
3170  *  trailing .name	entry in Dictionary
3171  *  trailing ->name()	method call
3172  *
3173  * "arg" must point to the first non-white of the expression.
3174  * "arg" is advanced to just after the recognized expression.
3175  *
3176  * Return OK or FAIL.
3177  */
3178     static int
3179 eval7(
3180     char_u	**arg,
3181     typval_T	*rettv,
3182     evalarg_T	*evalarg,
3183     int		want_string)	// after "." operator
3184 {
3185     int		evaluate = evalarg != NULL
3186 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3187     int		len;
3188     char_u	*s;
3189     char_u	*start_leader, *end_leader;
3190     int		ret = OK;
3191     char_u	*alias;
3192 
3193     /*
3194      * Initialise variable so that clear_tv() can't mistake this for a
3195      * string and free a string that isn't there.
3196      */
3197     rettv->v_type = VAR_UNKNOWN;
3198 
3199     /*
3200      * Skip '!', '-' and '+' characters.  They are handled later.
3201      */
3202     start_leader = *arg;
3203     while (**arg == '!' || **arg == '-' || **arg == '+')
3204 	*arg = skipwhite(*arg + 1);
3205     end_leader = *arg;
3206 
3207     if (**arg == '.' && (!isdigit(*(*arg + 1))
3208 #ifdef FEAT_FLOAT
3209 	    || current_sctx.sc_version < 2
3210 #endif
3211 	    ))
3212     {
3213 	semsg(_(e_invexpr2), *arg);
3214 	++*arg;
3215 	return FAIL;
3216     }
3217 
3218     switch (**arg)
3219     {
3220     /*
3221      * Number constant.
3222      */
3223     case '0':
3224     case '1':
3225     case '2':
3226     case '3':
3227     case '4':
3228     case '5':
3229     case '6':
3230     case '7':
3231     case '8':
3232     case '9':
3233     case '.':	ret = eval_number(arg, rettv, evaluate, want_string);
3234 
3235 		// Apply prefixed "-" and "+" now.  Matters especially when
3236 		// "->" follows.
3237 		if (ret == OK && evaluate && end_leader > start_leader
3238 						  && rettv->v_type != VAR_BLOB)
3239 		    ret = eval7_leader(rettv, TRUE, start_leader, &end_leader);
3240 		break;
3241 
3242     /*
3243      * String constant: "string".
3244      */
3245     case '"':	ret = eval_string(arg, rettv, evaluate);
3246 		break;
3247 
3248     /*
3249      * Literal string constant: 'str''ing'.
3250      */
3251     case '\'':	ret = eval_lit_string(arg, rettv, evaluate);
3252 		break;
3253 
3254     /*
3255      * List: [expr, expr]
3256      */
3257     case '[':	ret = eval_list(arg, rettv, evalarg, TRUE);
3258 		break;
3259 
3260     /*
3261      * Dictionary: #{key: val, key: val}
3262      */
3263     case '#':	if (!in_vim9script() && (*arg)[1] == '{')
3264 		{
3265 		    ++*arg;
3266 		    ret = eval_dict(arg, rettv, evalarg, TRUE);
3267 		}
3268 		else
3269 		    ret = NOTDONE;
3270 		break;
3271 
3272     /*
3273      * Lambda: {arg, arg -> expr}
3274      * Dictionary: {'key': val, 'key': val}
3275      */
3276     case '{':	ret = get_lambda_tv(arg, rettv, in_vim9script(), evalarg);
3277 		if (ret == NOTDONE)
3278 		    ret = eval_dict(arg, rettv, evalarg, FALSE);
3279 		break;
3280 
3281     /*
3282      * Option value: &name
3283      */
3284     case '&':	ret = eval_option(arg, rettv, evaluate);
3285 		break;
3286 
3287     /*
3288      * Environment variable: $VAR.
3289      */
3290     case '$':	ret = eval_env_var(arg, rettv, evaluate);
3291 		break;
3292 
3293     /*
3294      * Register contents: @r.
3295      */
3296     case '@':	++*arg;
3297 		if (evaluate)
3298 		{
3299 		    rettv->v_type = VAR_STRING;
3300 		    rettv->vval.v_string = get_reg_contents(**arg,
3301 							    GREG_EXPR_SRC);
3302 		}
3303 		if (**arg != NUL)
3304 		    ++*arg;
3305 		break;
3306 
3307     /*
3308      * nested expression: (expression).
3309      */
3310     case '(':	{
3311 		    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3312 		    ret = eval1(arg, rettv, evalarg);	// recursive!
3313 
3314 		    *arg = skipwhite_and_linebreak(*arg, evalarg);
3315 		    if (**arg == ')')
3316 			++*arg;
3317 		    else if (ret == OK)
3318 		    {
3319 			emsg(_(e_missing_close));
3320 			clear_tv(rettv);
3321 			ret = FAIL;
3322 		    }
3323 		}
3324 		break;
3325 
3326     default:	ret = NOTDONE;
3327 		break;
3328     }
3329 
3330     if (ret == NOTDONE)
3331     {
3332 	/*
3333 	 * Must be a variable or function name.
3334 	 * Can also be a curly-braces kind of name: {expr}.
3335 	 */
3336 	s = *arg;
3337 	len = get_name_len(arg, &alias, evaluate, TRUE);
3338 	if (alias != NULL)
3339 	    s = alias;
3340 
3341 	if (len <= 0)
3342 	    ret = FAIL;
3343 	else
3344 	{
3345 	    int	    flags = evalarg == NULL ? 0 : evalarg->eval_flags;
3346 
3347 	    if ((in_vim9script() ? **arg : *skipwhite(*arg)) == '(')
3348 	    {
3349 		// "name(..."  recursive!
3350 		*arg = skipwhite(*arg);
3351 		ret = eval_func(arg, evalarg, s, len, rettv, flags, NULL);
3352 	    }
3353 	    else if (flags & EVAL_CONSTANT)
3354 		ret = FAIL;
3355 	    else if (evaluate)
3356 	    {
3357 		// get the value of "true", "false" or a variable
3358 		if (len == 4 && in_vim9script() && STRNCMP(s, "true", 4) == 0)
3359 		{
3360 		    rettv->v_type = VAR_BOOL;
3361 		    rettv->vval.v_number = VVAL_TRUE;
3362 		    ret = OK;
3363 		}
3364 		else if (len == 5 && in_vim9script()
3365 						&& STRNCMP(s, "false", 4) == 0)
3366 		{
3367 		    rettv->v_type = VAR_BOOL;
3368 		    rettv->vval.v_number = VVAL_FALSE;
3369 		    ret = OK;
3370 		}
3371 		else
3372 		    ret = eval_variable(s, len, rettv, NULL, TRUE, FALSE);
3373 	    }
3374 	    else
3375 	    {
3376 		// skip the name
3377 		check_vars(s, len);
3378 		ret = OK;
3379 	    }
3380 	}
3381 	vim_free(alias);
3382     }
3383 
3384     // Handle following '[', '(' and '.' for expr[expr], expr.name,
3385     // expr(expr), expr->name(expr)
3386     if (ret == OK)
3387 	ret = handle_subscript(arg, rettv, evalarg, TRUE);
3388 
3389     /*
3390      * Apply logical NOT and unary '-', from right to left, ignore '+'.
3391      */
3392     if (ret == OK && evaluate && end_leader > start_leader)
3393 	ret = eval7_leader(rettv, FALSE, start_leader, &end_leader);
3394     return ret;
3395 }
3396 
3397 /*
3398  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
3399  * When "numeric_only" is TRUE only handle "+" and "-".
3400  * Adjusts "end_leaderp" until it is at "start_leader".
3401  */
3402     static int
3403 eval7_leader(
3404 	typval_T    *rettv,
3405 	int	    numeric_only,
3406 	char_u	    *start_leader,
3407 	char_u	    **end_leaderp)
3408 {
3409     char_u	*end_leader = *end_leaderp;
3410     int		ret = OK;
3411     int		error = FALSE;
3412     varnumber_T val = 0;
3413     vartype_T	type = rettv->v_type;
3414 #ifdef FEAT_FLOAT
3415     float_T	    f = 0.0;
3416 
3417     if (rettv->v_type == VAR_FLOAT)
3418 	f = rettv->vval.v_float;
3419     else
3420 #endif
3421     {
3422 	while (VIM_ISWHITE(end_leader[-1]))
3423 	    --end_leader;
3424 	if (in_vim9script() && end_leader[-1] == '!')
3425 	    val = tv2bool(rettv);
3426 	else
3427 	    val = tv_get_number_chk(rettv, &error);
3428     }
3429     if (error)
3430     {
3431 	clear_tv(rettv);
3432 	ret = FAIL;
3433     }
3434     else
3435     {
3436 	while (end_leader > start_leader)
3437 	{
3438 	    --end_leader;
3439 	    if (*end_leader == '!')
3440 	    {
3441 		if (numeric_only)
3442 		{
3443 		    ++end_leader;
3444 		    break;
3445 		}
3446 #ifdef FEAT_FLOAT
3447 		if (rettv->v_type == VAR_FLOAT)
3448 		{
3449 		    if (in_vim9script())
3450 		    {
3451 			rettv->v_type = VAR_BOOL;
3452 			val = f == 0.0 ? VVAL_TRUE : VVAL_FALSE;
3453 		    }
3454 		    else
3455 			f = !f;
3456 		}
3457 		else
3458 #endif
3459 		{
3460 		    val = !val;
3461 		    type = VAR_BOOL;
3462 		}
3463 	    }
3464 	    else if (*end_leader == '-')
3465 	    {
3466 #ifdef FEAT_FLOAT
3467 		if (rettv->v_type == VAR_FLOAT)
3468 		    f = -f;
3469 		else
3470 #endif
3471 		{
3472 		    val = -val;
3473 		    type = VAR_NUMBER;
3474 		}
3475 	    }
3476 	}
3477 #ifdef FEAT_FLOAT
3478 	if (rettv->v_type == VAR_FLOAT)
3479 	{
3480 	    clear_tv(rettv);
3481 	    rettv->vval.v_float = f;
3482 	}
3483 	else
3484 #endif
3485 	{
3486 	    clear_tv(rettv);
3487 	    if (in_vim9script())
3488 		rettv->v_type = type;
3489 	    else
3490 		rettv->v_type = VAR_NUMBER;
3491 	    rettv->vval.v_number = val;
3492 	}
3493     }
3494     *end_leaderp = end_leader;
3495     return ret;
3496 }
3497 
3498 /*
3499  * Call the function referred to in "rettv".
3500  */
3501     static int
3502 call_func_rettv(
3503 	char_u	    **arg,
3504 	evalarg_T   *evalarg,
3505 	typval_T    *rettv,
3506 	int	    evaluate,
3507 	dict_T	    *selfdict,
3508 	typval_T    *basetv)
3509 {
3510     partial_T	*pt = NULL;
3511     funcexe_T	funcexe;
3512     typval_T	functv;
3513     char_u	*s;
3514     int		ret;
3515 
3516     // need to copy the funcref so that we can clear rettv
3517     if (evaluate)
3518     {
3519 	functv = *rettv;
3520 	rettv->v_type = VAR_UNKNOWN;
3521 
3522 	// Invoke the function.  Recursive!
3523 	if (functv.v_type == VAR_PARTIAL)
3524 	{
3525 	    pt = functv.vval.v_partial;
3526 	    s = partial_name(pt);
3527 	}
3528 	else
3529 	    s = functv.vval.v_string;
3530     }
3531     else
3532 	s = (char_u *)"";
3533 
3534     CLEAR_FIELD(funcexe);
3535     funcexe.firstline = curwin->w_cursor.lnum;
3536     funcexe.lastline = curwin->w_cursor.lnum;
3537     funcexe.evaluate = evaluate;
3538     funcexe.partial = pt;
3539     funcexe.selfdict = selfdict;
3540     funcexe.basetv = basetv;
3541     ret = get_func_tv(s, -1, rettv, arg, evalarg, &funcexe);
3542 
3543     // Clear the funcref afterwards, so that deleting it while
3544     // evaluating the arguments is possible (see test55).
3545     if (evaluate)
3546 	clear_tv(&functv);
3547 
3548     return ret;
3549 }
3550 
3551 /*
3552  * Evaluate "->method()".
3553  * "*arg" points to the '-'.
3554  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3555  */
3556     static int
3557 eval_lambda(
3558     char_u	**arg,
3559     typval_T	*rettv,
3560     evalarg_T	*evalarg,
3561     int		verbose)	// give error messages
3562 {
3563     int		evaluate = evalarg != NULL
3564 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3565     typval_T	base = *rettv;
3566     int		ret;
3567 
3568     // Skip over the ->.
3569     *arg += 2;
3570     rettv->v_type = VAR_UNKNOWN;
3571 
3572     ret = get_lambda_tv(arg, rettv, FALSE, evalarg);
3573     if (ret != OK)
3574 	return FAIL;
3575     else if (**arg != '(')
3576     {
3577 	if (verbose)
3578 	{
3579 	    if (*skipwhite(*arg) == '(')
3580 		emsg(_(e_nowhitespace));
3581 	    else
3582 		semsg(_(e_missing_paren), "lambda");
3583 	}
3584 	clear_tv(rettv);
3585 	ret = FAIL;
3586     }
3587     else
3588 	ret = call_func_rettv(arg, evalarg, rettv, evaluate, NULL, &base);
3589 
3590     // Clear the funcref afterwards, so that deleting it while
3591     // evaluating the arguments is possible (see test55).
3592     if (evaluate)
3593 	clear_tv(&base);
3594 
3595     return ret;
3596 }
3597 
3598 /*
3599  * Evaluate "->method()".
3600  * "*arg" points to the '-'.
3601  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3602  */
3603     static int
3604 eval_method(
3605     char_u	**arg,
3606     typval_T	*rettv,
3607     evalarg_T	*evalarg,
3608     int		verbose)	// give error messages
3609 {
3610     char_u	*name;
3611     long	len;
3612     char_u	*alias;
3613     typval_T	base = *rettv;
3614     int		ret;
3615     int		evaluate = evalarg != NULL
3616 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3617 
3618     // Skip over the ->.
3619     *arg += 2;
3620     rettv->v_type = VAR_UNKNOWN;
3621 
3622     name = *arg;
3623     len = get_name_len(arg, &alias, evaluate, TRUE);
3624     if (alias != NULL)
3625 	name = alias;
3626 
3627     if (len <= 0)
3628     {
3629 	if (verbose)
3630 	    emsg(_("E260: Missing name after ->"));
3631 	ret = FAIL;
3632     }
3633     else
3634     {
3635 	*arg = skipwhite(*arg);
3636 	if (**arg != '(')
3637 	{
3638 	    if (verbose)
3639 		semsg(_(e_missing_paren), name);
3640 	    ret = FAIL;
3641 	}
3642 	else if (VIM_ISWHITE((*arg)[-1]))
3643 	{
3644 	    if (verbose)
3645 		emsg(_(e_nowhitespace));
3646 	    ret = FAIL;
3647 	}
3648 	else
3649 	    ret = eval_func(arg, evalarg, name, len, rettv,
3650 					  evaluate ? EVAL_EVALUATE : 0, &base);
3651     }
3652 
3653     // Clear the funcref afterwards, so that deleting it while
3654     // evaluating the arguments is possible (see test55).
3655     if (evaluate)
3656 	clear_tv(&base);
3657 
3658     return ret;
3659 }
3660 
3661 /*
3662  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
3663  * "*arg" points to the '[' or '.'.
3664  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
3665  */
3666     static int
3667 eval_index(
3668     char_u	**arg,
3669     typval_T	*rettv,
3670     evalarg_T	*evalarg,
3671     int		verbose)	// give error messages
3672 {
3673     int		evaluate = evalarg != NULL
3674 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3675     int		empty1 = FALSE, empty2 = FALSE;
3676     typval_T	var1, var2;
3677     int		range = FALSE;
3678     char_u	*key = NULL;
3679     int		keylen = -1;
3680 
3681     if (check_can_index(rettv, evaluate, verbose) == FAIL)
3682 	return FAIL;
3683 
3684     init_tv(&var1);
3685     init_tv(&var2);
3686     if (**arg == '.')
3687     {
3688 	/*
3689 	 * dict.name
3690 	 */
3691 	key = *arg + 1;
3692 	for (keylen = 0; eval_isdictc(key[keylen]); ++keylen)
3693 	    ;
3694 	if (keylen == 0)
3695 	    return FAIL;
3696 	*arg = key + keylen;
3697     }
3698     else
3699     {
3700 	/*
3701 	 * something[idx]
3702 	 *
3703 	 * Get the (first) variable from inside the [].
3704 	 */
3705 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3706 	if (**arg == ':')
3707 	    empty1 = TRUE;
3708 	else if (eval1(arg, &var1, evalarg) == FAIL)	// recursive!
3709 	    return FAIL;
3710 	else if (evaluate && tv_get_string_chk(&var1) == NULL)
3711 	{
3712 	    // not a number or string
3713 	    clear_tv(&var1);
3714 	    return FAIL;
3715 	}
3716 
3717 	/*
3718 	 * Get the second variable from inside the [:].
3719 	 */
3720 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3721 	if (**arg == ':')
3722 	{
3723 	    range = TRUE;
3724 	    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3725 	    if (**arg == ']')
3726 		empty2 = TRUE;
3727 	    else if (eval1(arg, &var2, evalarg) == FAIL)	// recursive!
3728 	    {
3729 		if (!empty1)
3730 		    clear_tv(&var1);
3731 		return FAIL;
3732 	    }
3733 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
3734 	    {
3735 		// not a number or string
3736 		if (!empty1)
3737 		    clear_tv(&var1);
3738 		clear_tv(&var2);
3739 		return FAIL;
3740 	    }
3741 	}
3742 
3743 	// Check for the ']'.
3744 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3745 	if (**arg != ']')
3746 	{
3747 	    if (verbose)
3748 		emsg(_(e_missbrac));
3749 	    clear_tv(&var1);
3750 	    if (range)
3751 		clear_tv(&var2);
3752 	    return FAIL;
3753 	}
3754 	*arg = *arg + 1;	// skip over the ']'
3755     }
3756 
3757     if (evaluate)
3758     {
3759 	int res = eval_index_inner(rettv, range,
3760 		empty1 ? NULL : &var1, empty2 ? NULL : &var2,
3761 		key, keylen, verbose);
3762 	if (!empty1)
3763 	    clear_tv(&var1);
3764 	if (range)
3765 	    clear_tv(&var2);
3766 	return res;
3767     }
3768     return OK;
3769 }
3770 
3771 /*
3772  * Check if "rettv" can have an [index] or [sli:ce]
3773  */
3774     int
3775 check_can_index(typval_T *rettv, int evaluate, int verbose)
3776 {
3777     switch (rettv->v_type)
3778     {
3779 	case VAR_FUNC:
3780 	case VAR_PARTIAL:
3781 	    if (verbose)
3782 		emsg(_("E695: Cannot index a Funcref"));
3783 	    return FAIL;
3784 	case VAR_FLOAT:
3785 #ifdef FEAT_FLOAT
3786 	    if (verbose)
3787 		emsg(_(e_float_as_string));
3788 	    return FAIL;
3789 #endif
3790 	case VAR_BOOL:
3791 	case VAR_SPECIAL:
3792 	case VAR_JOB:
3793 	case VAR_CHANNEL:
3794 	    if (verbose)
3795 		emsg(_(e_cannot_index_special_variable));
3796 	    return FAIL;
3797 	case VAR_UNKNOWN:
3798 	case VAR_ANY:
3799 	case VAR_VOID:
3800 	    if (evaluate)
3801 	    {
3802 		emsg(_(e_cannot_index_special_variable));
3803 		return FAIL;
3804 	    }
3805 	    // FALLTHROUGH
3806 
3807 	case VAR_STRING:
3808 	case VAR_LIST:
3809 	case VAR_DICT:
3810 	case VAR_BLOB:
3811 	    break;
3812 	case VAR_NUMBER:
3813 	    if (in_vim9script())
3814 		emsg(_(e_cannot_index_number));
3815 	    break;
3816     }
3817     return OK;
3818 }
3819 
3820 /*
3821  * Apply index or range to "rettv".
3822  * "var1" is the first index, NULL for [:expr].
3823  * "var2" is the second index, NULL for [expr] and [expr: ]
3824  * Alternatively, "key" is not NULL, then key[keylen] is the dict index.
3825  */
3826     int
3827 eval_index_inner(
3828 	typval_T    *rettv,
3829 	int	    is_range,
3830 	typval_T    *var1,
3831 	typval_T    *var2,
3832 	char_u	    *key,
3833 	int	    keylen,
3834 	int	    verbose)
3835 {
3836     long	n1, n2 = 0;
3837     long	len;
3838 
3839     n1 = 0;
3840     if (var1 != NULL && rettv->v_type != VAR_DICT)
3841 	n1 = tv_get_number(var1);
3842 
3843     if (is_range)
3844     {
3845 	if (rettv->v_type == VAR_DICT)
3846 	{
3847 	    if (verbose)
3848 		emsg(_(e_cannot_slice_dictionary));
3849 	    return FAIL;
3850 	}
3851 	if (var2 == NULL)
3852 	    n2 = -1;
3853 	else
3854 	    n2 = tv_get_number(var2);
3855     }
3856 
3857     switch (rettv->v_type)
3858     {
3859 	case VAR_UNKNOWN:
3860 	case VAR_ANY:
3861 	case VAR_VOID:
3862 	case VAR_FUNC:
3863 	case VAR_PARTIAL:
3864 	case VAR_FLOAT:
3865 	case VAR_BOOL:
3866 	case VAR_SPECIAL:
3867 	case VAR_JOB:
3868 	case VAR_CHANNEL:
3869 	    break; // not evaluating, skipping over subscript
3870 
3871 	case VAR_NUMBER:
3872 	case VAR_STRING:
3873 	    {
3874 		char_u	*s = tv_get_string(rettv);
3875 
3876 		len = (long)STRLEN(s);
3877 		if (in_vim9script())
3878 		{
3879 		    if (is_range)
3880 			s = string_slice(s, n1, n2);
3881 		    else
3882 			s = char_from_string(s, n1);
3883 		}
3884 		else if (is_range)
3885 		{
3886 		    // The resulting variable is a substring.  If the indexes
3887 		    // are out of range the result is empty.
3888 		    if (n1 < 0)
3889 		    {
3890 			n1 = len + n1;
3891 			if (n1 < 0)
3892 			    n1 = 0;
3893 		    }
3894 		    if (n2 < 0)
3895 			n2 = len + n2;
3896 		    else if (n2 >= len)
3897 			n2 = len;
3898 		    if (n1 >= len || n2 < 0 || n1 > n2)
3899 			s = NULL;
3900 		    else
3901 			s = vim_strnsave(s + n1, n2 - n1 + 1);
3902 		}
3903 		else
3904 		{
3905 		    // The resulting variable is a string of a single
3906 		    // character.  If the index is too big or negative the
3907 		    // result is empty.
3908 		    if (n1 >= len || n1 < 0)
3909 			s = NULL;
3910 		    else
3911 			s = vim_strnsave(s + n1, 1);
3912 		}
3913 		clear_tv(rettv);
3914 		rettv->v_type = VAR_STRING;
3915 		rettv->vval.v_string = s;
3916 	    }
3917 	    break;
3918 
3919 	case VAR_BLOB:
3920 	    len = blob_len(rettv->vval.v_blob);
3921 	    if (is_range)
3922 	    {
3923 		// The resulting variable is a sub-blob.  If the indexes
3924 		// are out of range the result is empty.
3925 		if (n1 < 0)
3926 		{
3927 		    n1 = len + n1;
3928 		    if (n1 < 0)
3929 			n1 = 0;
3930 		}
3931 		if (n2 < 0)
3932 		    n2 = len + n2;
3933 		else if (n2 >= len)
3934 		    n2 = len - 1;
3935 		if (n1 >= len || n2 < 0 || n1 > n2)
3936 		{
3937 		    clear_tv(rettv);
3938 		    rettv->v_type = VAR_BLOB;
3939 		    rettv->vval.v_blob = NULL;
3940 		}
3941 		else
3942 		{
3943 		    blob_T  *blob = blob_alloc();
3944 		    long    i;
3945 
3946 		    if (blob != NULL)
3947 		    {
3948 			if (ga_grow(&blob->bv_ga, n2 - n1 + 1) == FAIL)
3949 			{
3950 			    blob_free(blob);
3951 			    return FAIL;
3952 			}
3953 			blob->bv_ga.ga_len = n2 - n1 + 1;
3954 			for (i = n1; i <= n2; i++)
3955 			    blob_set(blob, i - n1,
3956 					  blob_get(rettv->vval.v_blob, i));
3957 
3958 			clear_tv(rettv);
3959 			rettv_blob_set(rettv, blob);
3960 		    }
3961 		}
3962 	    }
3963 	    else
3964 	    {
3965 		// The resulting variable is a byte value.
3966 		// If the index is too big or negative that is an error.
3967 		if (n1 < 0)
3968 		    n1 = len + n1;
3969 		if (n1 < len && n1 >= 0)
3970 		{
3971 		    int v = blob_get(rettv->vval.v_blob, n1);
3972 
3973 		    clear_tv(rettv);
3974 		    rettv->v_type = VAR_NUMBER;
3975 		    rettv->vval.v_number = v;
3976 		}
3977 		else
3978 		    semsg(_(e_blobidx), n1);
3979 	    }
3980 	    break;
3981 
3982 	case VAR_LIST:
3983 	    if (var1 == NULL)
3984 		n1 = 0;
3985 	    if (var2 == NULL)
3986 		n2 = -1;
3987 	    if (list_slice_or_index(rettv->vval.v_list,
3988 				    is_range, n1, n2, rettv, verbose) == FAIL)
3989 		return FAIL;
3990 	    break;
3991 
3992 	case VAR_DICT:
3993 	    {
3994 		dictitem_T	*item;
3995 		typval_T	tmp;
3996 
3997 		if (key == NULL)
3998 		{
3999 		    key = tv_get_string_chk(var1);
4000 		    if (key == NULL)
4001 			return FAIL;
4002 		}
4003 
4004 		item = dict_find(rettv->vval.v_dict, key, (int)keylen);
4005 
4006 		if (item == NULL && verbose)
4007 		    semsg(_(e_dictkey), key);
4008 		if (item == NULL)
4009 		    return FAIL;
4010 
4011 		copy_tv(&item->di_tv, &tmp);
4012 		clear_tv(rettv);
4013 		*rettv = tmp;
4014 	    }
4015 	    break;
4016     }
4017     return OK;
4018 }
4019 
4020 /*
4021  * Return the function name of partial "pt".
4022  */
4023     char_u *
4024 partial_name(partial_T *pt)
4025 {
4026     if (pt->pt_name != NULL)
4027 	return pt->pt_name;
4028     if (pt->pt_func != NULL)
4029 	return pt->pt_func->uf_name;
4030     return (char_u *)"";
4031 }
4032 
4033     static void
4034 partial_free(partial_T *pt)
4035 {
4036     int i;
4037 
4038     for (i = 0; i < pt->pt_argc; ++i)
4039 	clear_tv(&pt->pt_argv[i]);
4040     vim_free(pt->pt_argv);
4041     dict_unref(pt->pt_dict);
4042     if (pt->pt_name != NULL)
4043     {
4044 	func_unref(pt->pt_name);
4045 	vim_free(pt->pt_name);
4046     }
4047     else
4048 	func_ptr_unref(pt->pt_func);
4049 
4050     // Decrease the reference count for the context of a closure.  If down
4051     // to the minimum it may be time to free it.
4052     if (pt->pt_funcstack != NULL)
4053     {
4054 	--pt->pt_funcstack->fs_refcount;
4055 	funcstack_check_refcount(pt->pt_funcstack);
4056     }
4057 
4058     vim_free(pt);
4059 }
4060 
4061 /*
4062  * Unreference a closure: decrement the reference count and free it when it
4063  * becomes zero.
4064  */
4065     void
4066 partial_unref(partial_T *pt)
4067 {
4068     if (pt != NULL)
4069     {
4070 	if (--pt->pt_refcount <= 0)
4071 	    partial_free(pt);
4072 
4073 	// If the reference count goes down to one, the funcstack may be the
4074 	// only reference and can be freed if no other partials reference it.
4075 	else if (pt->pt_refcount == 1 && pt->pt_funcstack != NULL)
4076 	    funcstack_check_refcount(pt->pt_funcstack);
4077     }
4078 }
4079 
4080 /*
4081  * Return the next (unique) copy ID.
4082  * Used for serializing nested structures.
4083  */
4084     int
4085 get_copyID(void)
4086 {
4087     current_copyID += COPYID_INC;
4088     return current_copyID;
4089 }
4090 
4091 /*
4092  * Garbage collection for lists and dictionaries.
4093  *
4094  * We use reference counts to be able to free most items right away when they
4095  * are no longer used.  But for composite items it's possible that it becomes
4096  * unused while the reference count is > 0: When there is a recursive
4097  * reference.  Example:
4098  *	:let l = [1, 2, 3]
4099  *	:let d = {9: l}
4100  *	:let l[1] = d
4101  *
4102  * Since this is quite unusual we handle this with garbage collection: every
4103  * once in a while find out which lists and dicts are not referenced from any
4104  * variable.
4105  *
4106  * Here is a good reference text about garbage collection (refers to Python
4107  * but it applies to all reference-counting mechanisms):
4108  *	http://python.ca/nas/python/gc/
4109  */
4110 
4111 /*
4112  * Do garbage collection for lists and dicts.
4113  * When "testing" is TRUE this is called from test_garbagecollect_now().
4114  * Return TRUE if some memory was freed.
4115  */
4116     int
4117 garbage_collect(int testing)
4118 {
4119     int		copyID;
4120     int		abort = FALSE;
4121     buf_T	*buf;
4122     win_T	*wp;
4123     int		did_free = FALSE;
4124     tabpage_T	*tp;
4125 
4126     if (!testing)
4127     {
4128 	// Only do this once.
4129 	want_garbage_collect = FALSE;
4130 	may_garbage_collect = FALSE;
4131 	garbage_collect_at_exit = FALSE;
4132     }
4133 
4134     // The execution stack can grow big, limit the size.
4135     if (exestack.ga_maxlen - exestack.ga_len > 500)
4136     {
4137 	size_t	new_len;
4138 	char_u	*pp;
4139 	int	n;
4140 
4141 	// Keep 150% of the current size, with a minimum of the growth size.
4142 	n = exestack.ga_len / 2;
4143 	if (n < exestack.ga_growsize)
4144 	    n = exestack.ga_growsize;
4145 
4146 	// Don't make it bigger though.
4147 	if (exestack.ga_len + n < exestack.ga_maxlen)
4148 	{
4149 	    new_len = exestack.ga_itemsize * (exestack.ga_len + n);
4150 	    pp = vim_realloc(exestack.ga_data, new_len);
4151 	    if (pp == NULL)
4152 		return FAIL;
4153 	    exestack.ga_maxlen = exestack.ga_len + n;
4154 	    exestack.ga_data = pp;
4155 	}
4156     }
4157 
4158     // We advance by two because we add one for items referenced through
4159     // previous_funccal.
4160     copyID = get_copyID();
4161 
4162     /*
4163      * 1. Go through all accessible variables and mark all lists and dicts
4164      *    with copyID.
4165      */
4166 
4167     // Don't free variables in the previous_funccal list unless they are only
4168     // referenced through previous_funccal.  This must be first, because if
4169     // the item is referenced elsewhere the funccal must not be freed.
4170     abort = abort || set_ref_in_previous_funccal(copyID);
4171 
4172     // script-local variables
4173     abort = abort || garbage_collect_scriptvars(copyID);
4174 
4175     // buffer-local variables
4176     FOR_ALL_BUFFERS(buf)
4177 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
4178 								  NULL, NULL);
4179 
4180     // window-local variables
4181     FOR_ALL_TAB_WINDOWS(tp, wp)
4182 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4183 								  NULL, NULL);
4184     if (aucmd_win != NULL)
4185 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
4186 								  NULL, NULL);
4187 #ifdef FEAT_PROP_POPUP
4188     FOR_ALL_POPUPWINS(wp)
4189 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4190 								  NULL, NULL);
4191     FOR_ALL_TABPAGES(tp)
4192 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
4193 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4194 								  NULL, NULL);
4195 #endif
4196 
4197     // tabpage-local variables
4198     FOR_ALL_TABPAGES(tp)
4199 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
4200 								  NULL, NULL);
4201     // global variables
4202     abort = abort || garbage_collect_globvars(copyID);
4203 
4204     // function-local variables
4205     abort = abort || set_ref_in_call_stack(copyID);
4206 
4207     // named functions (matters for closures)
4208     abort = abort || set_ref_in_functions(copyID);
4209 
4210     // function call arguments, if v:testing is set.
4211     abort = abort || set_ref_in_func_args(copyID);
4212 
4213     // v: vars
4214     abort = abort || garbage_collect_vimvars(copyID);
4215 
4216     // callbacks in buffers
4217     abort = abort || set_ref_in_buffers(copyID);
4218 
4219 #ifdef FEAT_LUA
4220     abort = abort || set_ref_in_lua(copyID);
4221 #endif
4222 
4223 #ifdef FEAT_PYTHON
4224     abort = abort || set_ref_in_python(copyID);
4225 #endif
4226 
4227 #ifdef FEAT_PYTHON3
4228     abort = abort || set_ref_in_python3(copyID);
4229 #endif
4230 
4231 #ifdef FEAT_JOB_CHANNEL
4232     abort = abort || set_ref_in_channel(copyID);
4233     abort = abort || set_ref_in_job(copyID);
4234 #endif
4235 #ifdef FEAT_NETBEANS_INTG
4236     abort = abort || set_ref_in_nb_channel(copyID);
4237 #endif
4238 
4239 #ifdef FEAT_TIMERS
4240     abort = abort || set_ref_in_timer(copyID);
4241 #endif
4242 
4243 #ifdef FEAT_QUICKFIX
4244     abort = abort || set_ref_in_quickfix(copyID);
4245 #endif
4246 
4247 #ifdef FEAT_TERMINAL
4248     abort = abort || set_ref_in_term(copyID);
4249 #endif
4250 
4251 #ifdef FEAT_PROP_POPUP
4252     abort = abort || set_ref_in_popups(copyID);
4253 #endif
4254 
4255     if (!abort)
4256     {
4257 	/*
4258 	 * 2. Free lists and dictionaries that are not referenced.
4259 	 */
4260 	did_free = free_unref_items(copyID);
4261 
4262 	/*
4263 	 * 3. Check if any funccal can be freed now.
4264 	 *    This may call us back recursively.
4265 	 */
4266 	free_unref_funccal(copyID, testing);
4267     }
4268     else if (p_verbose > 0)
4269     {
4270 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
4271     }
4272 
4273     return did_free;
4274 }
4275 
4276 /*
4277  * Free lists, dictionaries, channels and jobs that are no longer referenced.
4278  */
4279     static int
4280 free_unref_items(int copyID)
4281 {
4282     int		did_free = FALSE;
4283 
4284     // Let all "free" functions know that we are here.  This means no
4285     // dictionaries, lists, channels or jobs are to be freed, because we will
4286     // do that here.
4287     in_free_unref_items = TRUE;
4288 
4289     /*
4290      * PASS 1: free the contents of the items.  We don't free the items
4291      * themselves yet, so that it is possible to decrement refcount counters
4292      */
4293 
4294     // Go through the list of dicts and free items without the copyID.
4295     did_free |= dict_free_nonref(copyID);
4296 
4297     // Go through the list of lists and free items without the copyID.
4298     did_free |= list_free_nonref(copyID);
4299 
4300 #ifdef FEAT_JOB_CHANNEL
4301     // Go through the list of jobs and free items without the copyID. This
4302     // must happen before doing channels, because jobs refer to channels, but
4303     // the reference from the channel to the job isn't tracked.
4304     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4305 
4306     // Go through the list of channels and free items without the copyID.
4307     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4308 #endif
4309 
4310     /*
4311      * PASS 2: free the items themselves.
4312      */
4313     dict_free_items(copyID);
4314     list_free_items(copyID);
4315 
4316 #ifdef FEAT_JOB_CHANNEL
4317     // Go through the list of jobs and free items without the copyID. This
4318     // must happen before doing channels, because jobs refer to channels, but
4319     // the reference from the channel to the job isn't tracked.
4320     free_unused_jobs(copyID, COPYID_MASK);
4321 
4322     // Go through the list of channels and free items without the copyID.
4323     free_unused_channels(copyID, COPYID_MASK);
4324 #endif
4325 
4326     in_free_unref_items = FALSE;
4327 
4328     return did_free;
4329 }
4330 
4331 /*
4332  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4333  * "list_stack" is used to add lists to be marked.  Can be NULL.
4334  *
4335  * Returns TRUE if setting references failed somehow.
4336  */
4337     int
4338 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4339 {
4340     int		todo;
4341     int		abort = FALSE;
4342     hashitem_T	*hi;
4343     hashtab_T	*cur_ht;
4344     ht_stack_T	*ht_stack = NULL;
4345     ht_stack_T	*tempitem;
4346 
4347     cur_ht = ht;
4348     for (;;)
4349     {
4350 	if (!abort)
4351 	{
4352 	    // Mark each item in the hashtab.  If the item contains a hashtab
4353 	    // it is added to ht_stack, if it contains a list it is added to
4354 	    // list_stack.
4355 	    todo = (int)cur_ht->ht_used;
4356 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4357 		if (!HASHITEM_EMPTY(hi))
4358 		{
4359 		    --todo;
4360 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4361 						       &ht_stack, list_stack);
4362 		}
4363 	}
4364 
4365 	if (ht_stack == NULL)
4366 	    break;
4367 
4368 	// take an item from the stack
4369 	cur_ht = ht_stack->ht;
4370 	tempitem = ht_stack;
4371 	ht_stack = ht_stack->prev;
4372 	free(tempitem);
4373     }
4374 
4375     return abort;
4376 }
4377 
4378 /*
4379  * Mark a dict and its items with "copyID".
4380  * Returns TRUE if setting references failed somehow.
4381  */
4382     int
4383 set_ref_in_dict(dict_T *d, int copyID)
4384 {
4385     if (d != NULL && d->dv_copyID != copyID)
4386     {
4387 	d->dv_copyID = copyID;
4388 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4389     }
4390     return FALSE;
4391 }
4392 
4393 /*
4394  * Mark a list and its items with "copyID".
4395  * Returns TRUE if setting references failed somehow.
4396  */
4397     int
4398 set_ref_in_list(list_T *ll, int copyID)
4399 {
4400     if (ll != NULL && ll->lv_copyID != copyID)
4401     {
4402 	ll->lv_copyID = copyID;
4403 	return set_ref_in_list_items(ll, copyID, NULL);
4404     }
4405     return FALSE;
4406 }
4407 
4408 /*
4409  * Mark all lists and dicts referenced through list "l" with "copyID".
4410  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4411  *
4412  * Returns TRUE if setting references failed somehow.
4413  */
4414     int
4415 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4416 {
4417     listitem_T	 *li;
4418     int		 abort = FALSE;
4419     list_T	 *cur_l;
4420     list_stack_T *list_stack = NULL;
4421     list_stack_T *tempitem;
4422 
4423     cur_l = l;
4424     for (;;)
4425     {
4426 	if (!abort && cur_l->lv_first != &range_list_item)
4427 	    // Mark each item in the list.  If the item contains a hashtab
4428 	    // it is added to ht_stack, if it contains a list it is added to
4429 	    // list_stack.
4430 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4431 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4432 						       ht_stack, &list_stack);
4433 	if (list_stack == NULL)
4434 	    break;
4435 
4436 	// take an item from the stack
4437 	cur_l = list_stack->list;
4438 	tempitem = list_stack;
4439 	list_stack = list_stack->prev;
4440 	free(tempitem);
4441     }
4442 
4443     return abort;
4444 }
4445 
4446 /*
4447  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4448  * "list_stack" is used to add lists to be marked.  Can be NULL.
4449  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4450  *
4451  * Returns TRUE if setting references failed somehow.
4452  */
4453     int
4454 set_ref_in_item(
4455     typval_T	    *tv,
4456     int		    copyID,
4457     ht_stack_T	    **ht_stack,
4458     list_stack_T    **list_stack)
4459 {
4460     int		abort = FALSE;
4461 
4462     if (tv->v_type == VAR_DICT)
4463     {
4464 	dict_T	*dd = tv->vval.v_dict;
4465 
4466 	if (dd != NULL && dd->dv_copyID != copyID)
4467 	{
4468 	    // Didn't see this dict yet.
4469 	    dd->dv_copyID = copyID;
4470 	    if (ht_stack == NULL)
4471 	    {
4472 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4473 	    }
4474 	    else
4475 	    {
4476 		ht_stack_T *newitem = ALLOC_ONE(ht_stack_T);
4477 
4478 		if (newitem == NULL)
4479 		    abort = TRUE;
4480 		else
4481 		{
4482 		    newitem->ht = &dd->dv_hashtab;
4483 		    newitem->prev = *ht_stack;
4484 		    *ht_stack = newitem;
4485 		}
4486 	    }
4487 	}
4488     }
4489     else if (tv->v_type == VAR_LIST)
4490     {
4491 	list_T	*ll = tv->vval.v_list;
4492 
4493 	if (ll != NULL && ll->lv_copyID != copyID)
4494 	{
4495 	    // Didn't see this list yet.
4496 	    ll->lv_copyID = copyID;
4497 	    if (list_stack == NULL)
4498 	    {
4499 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4500 	    }
4501 	    else
4502 	    {
4503 		list_stack_T *newitem = ALLOC_ONE(list_stack_T);
4504 
4505 		if (newitem == NULL)
4506 		    abort = TRUE;
4507 		else
4508 		{
4509 		    newitem->list = ll;
4510 		    newitem->prev = *list_stack;
4511 		    *list_stack = newitem;
4512 		}
4513 	    }
4514 	}
4515     }
4516     else if (tv->v_type == VAR_FUNC)
4517     {
4518 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4519     }
4520     else if (tv->v_type == VAR_PARTIAL)
4521     {
4522 	partial_T	*pt = tv->vval.v_partial;
4523 	int		i;
4524 
4525 	if (pt != NULL && pt->pt_copyID != copyID)
4526 	{
4527 	    // Didn't see this partial yet.
4528 	    pt->pt_copyID = copyID;
4529 
4530 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4531 
4532 	    if (pt->pt_dict != NULL)
4533 	    {
4534 		typval_T dtv;
4535 
4536 		dtv.v_type = VAR_DICT;
4537 		dtv.vval.v_dict = pt->pt_dict;
4538 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4539 	    }
4540 
4541 	    for (i = 0; i < pt->pt_argc; ++i)
4542 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4543 							ht_stack, list_stack);
4544 	    if (pt->pt_funcstack != NULL)
4545 	    {
4546 		typval_T    *stack = pt->pt_funcstack->fs_ga.ga_data;
4547 
4548 		for (i = 0; i < pt->pt_funcstack->fs_ga.ga_len; ++i)
4549 		    abort = abort || set_ref_in_item(stack + i, copyID,
4550 							 ht_stack, list_stack);
4551 	    }
4552 
4553 	}
4554     }
4555 #ifdef FEAT_JOB_CHANNEL
4556     else if (tv->v_type == VAR_JOB)
4557     {
4558 	job_T	    *job = tv->vval.v_job;
4559 	typval_T    dtv;
4560 
4561 	if (job != NULL && job->jv_copyID != copyID)
4562 	{
4563 	    job->jv_copyID = copyID;
4564 	    if (job->jv_channel != NULL)
4565 	    {
4566 		dtv.v_type = VAR_CHANNEL;
4567 		dtv.vval.v_channel = job->jv_channel;
4568 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4569 	    }
4570 	    if (job->jv_exit_cb.cb_partial != NULL)
4571 	    {
4572 		dtv.v_type = VAR_PARTIAL;
4573 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4574 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4575 	    }
4576 	}
4577     }
4578     else if (tv->v_type == VAR_CHANNEL)
4579     {
4580 	channel_T   *ch =tv->vval.v_channel;
4581 	ch_part_T   part;
4582 	typval_T    dtv;
4583 	jsonq_T	    *jq;
4584 	cbq_T	    *cq;
4585 
4586 	if (ch != NULL && ch->ch_copyID != copyID)
4587 	{
4588 	    ch->ch_copyID = copyID;
4589 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4590 	    {
4591 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4592 							     jq = jq->jq_next)
4593 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4594 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4595 							     cq = cq->cq_next)
4596 		    if (cq->cq_callback.cb_partial != NULL)
4597 		    {
4598 			dtv.v_type = VAR_PARTIAL;
4599 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4600 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4601 		    }
4602 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4603 		{
4604 		    dtv.v_type = VAR_PARTIAL;
4605 		    dtv.vval.v_partial =
4606 				      ch->ch_part[part].ch_callback.cb_partial;
4607 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4608 		}
4609 	    }
4610 	    if (ch->ch_callback.cb_partial != NULL)
4611 	    {
4612 		dtv.v_type = VAR_PARTIAL;
4613 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4614 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4615 	    }
4616 	    if (ch->ch_close_cb.cb_partial != NULL)
4617 	    {
4618 		dtv.v_type = VAR_PARTIAL;
4619 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4620 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4621 	    }
4622 	}
4623     }
4624 #endif
4625     return abort;
4626 }
4627 
4628 /*
4629  * Return a string with the string representation of a variable.
4630  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4631  * "numbuf" is used for a number.
4632  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4633  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4634  * stings as "string()", otherwise does not put quotes around strings, as
4635  * ":echo" displays values.
4636  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4637  * are replaced with "...".
4638  * May return NULL.
4639  */
4640     char_u *
4641 echo_string_core(
4642     typval_T	*tv,
4643     char_u	**tofree,
4644     char_u	*numbuf,
4645     int		copyID,
4646     int		echo_style,
4647     int		restore_copyID,
4648     int		composite_val)
4649 {
4650     static int	recurse = 0;
4651     char_u	*r = NULL;
4652 
4653     if (recurse >= DICT_MAXNEST)
4654     {
4655 	if (!did_echo_string_emsg)
4656 	{
4657 	    // Only give this message once for a recursive call to avoid
4658 	    // flooding the user with errors.  And stop iterating over lists
4659 	    // and dicts.
4660 	    did_echo_string_emsg = TRUE;
4661 	    emsg(_("E724: variable nested too deep for displaying"));
4662 	}
4663 	*tofree = NULL;
4664 	return (char_u *)"{E724}";
4665     }
4666     ++recurse;
4667 
4668     switch (tv->v_type)
4669     {
4670 	case VAR_STRING:
4671 	    if (echo_style && !composite_val)
4672 	    {
4673 		*tofree = NULL;
4674 		r = tv->vval.v_string;
4675 		if (r == NULL)
4676 		    r = (char_u *)"";
4677 	    }
4678 	    else
4679 	    {
4680 		*tofree = string_quote(tv->vval.v_string, FALSE);
4681 		r = *tofree;
4682 	    }
4683 	    break;
4684 
4685 	case VAR_FUNC:
4686 	    if (echo_style)
4687 	    {
4688 		*tofree = NULL;
4689 		r = tv->vval.v_string;
4690 	    }
4691 	    else
4692 	    {
4693 		*tofree = string_quote(tv->vval.v_string, TRUE);
4694 		r = *tofree;
4695 	    }
4696 	    break;
4697 
4698 	case VAR_PARTIAL:
4699 	    {
4700 		partial_T   *pt = tv->vval.v_partial;
4701 		char_u	    *fname = string_quote(pt == NULL ? NULL
4702 						    : partial_name(pt), FALSE);
4703 		garray_T    ga;
4704 		int	    i;
4705 		char_u	    *tf;
4706 
4707 		ga_init2(&ga, 1, 100);
4708 		ga_concat(&ga, (char_u *)"function(");
4709 		if (fname != NULL)
4710 		{
4711 		    ga_concat(&ga, fname);
4712 		    vim_free(fname);
4713 		}
4714 		if (pt != NULL && pt->pt_argc > 0)
4715 		{
4716 		    ga_concat(&ga, (char_u *)", [");
4717 		    for (i = 0; i < pt->pt_argc; ++i)
4718 		    {
4719 			if (i > 0)
4720 			    ga_concat(&ga, (char_u *)", ");
4721 			ga_concat(&ga,
4722 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
4723 			vim_free(tf);
4724 		    }
4725 		    ga_concat(&ga, (char_u *)"]");
4726 		}
4727 		if (pt != NULL && pt->pt_dict != NULL)
4728 		{
4729 		    typval_T dtv;
4730 
4731 		    ga_concat(&ga, (char_u *)", ");
4732 		    dtv.v_type = VAR_DICT;
4733 		    dtv.vval.v_dict = pt->pt_dict;
4734 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
4735 		    vim_free(tf);
4736 		}
4737 		ga_concat(&ga, (char_u *)")");
4738 
4739 		*tofree = ga.ga_data;
4740 		r = *tofree;
4741 		break;
4742 	    }
4743 
4744 	case VAR_BLOB:
4745 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
4746 	    break;
4747 
4748 	case VAR_LIST:
4749 	    if (tv->vval.v_list == NULL)
4750 	    {
4751 		// NULL list is equivalent to empty list.
4752 		*tofree = NULL;
4753 		r = (char_u *)"[]";
4754 	    }
4755 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
4756 		    && tv->vval.v_list->lv_len > 0)
4757 	    {
4758 		*tofree = NULL;
4759 		r = (char_u *)"[...]";
4760 	    }
4761 	    else
4762 	    {
4763 		int old_copyID = tv->vval.v_list->lv_copyID;
4764 
4765 		tv->vval.v_list->lv_copyID = copyID;
4766 		*tofree = list2string(tv, copyID, restore_copyID);
4767 		if (restore_copyID)
4768 		    tv->vval.v_list->lv_copyID = old_copyID;
4769 		r = *tofree;
4770 	    }
4771 	    break;
4772 
4773 	case VAR_DICT:
4774 	    if (tv->vval.v_dict == NULL)
4775 	    {
4776 		// NULL dict is equivalent to empty dict.
4777 		*tofree = NULL;
4778 		r = (char_u *)"{}";
4779 	    }
4780 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
4781 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
4782 	    {
4783 		*tofree = NULL;
4784 		r = (char_u *)"{...}";
4785 	    }
4786 	    else
4787 	    {
4788 		int old_copyID = tv->vval.v_dict->dv_copyID;
4789 
4790 		tv->vval.v_dict->dv_copyID = copyID;
4791 		*tofree = dict2string(tv, copyID, restore_copyID);
4792 		if (restore_copyID)
4793 		    tv->vval.v_dict->dv_copyID = old_copyID;
4794 		r = *tofree;
4795 	    }
4796 	    break;
4797 
4798 	case VAR_NUMBER:
4799 	case VAR_UNKNOWN:
4800 	case VAR_ANY:
4801 	case VAR_VOID:
4802 	    *tofree = NULL;
4803 	    r = tv_get_string_buf(tv, numbuf);
4804 	    break;
4805 
4806 	case VAR_JOB:
4807 	case VAR_CHANNEL:
4808 	    *tofree = NULL;
4809 	    r = tv_get_string_buf(tv, numbuf);
4810 	    if (composite_val)
4811 	    {
4812 		*tofree = string_quote(r, FALSE);
4813 		r = *tofree;
4814 	    }
4815 	    break;
4816 
4817 	case VAR_FLOAT:
4818 #ifdef FEAT_FLOAT
4819 	    *tofree = NULL;
4820 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
4821 	    r = numbuf;
4822 	    break;
4823 #endif
4824 
4825 	case VAR_BOOL:
4826 	case VAR_SPECIAL:
4827 	    *tofree = NULL;
4828 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
4829 	    break;
4830     }
4831 
4832     if (--recurse == 0)
4833 	did_echo_string_emsg = FALSE;
4834     return r;
4835 }
4836 
4837 /*
4838  * Return a string with the string representation of a variable.
4839  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4840  * "numbuf" is used for a number.
4841  * Does not put quotes around strings, as ":echo" displays values.
4842  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4843  * May return NULL.
4844  */
4845     char_u *
4846 echo_string(
4847     typval_T	*tv,
4848     char_u	**tofree,
4849     char_u	*numbuf,
4850     int		copyID)
4851 {
4852     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
4853 }
4854 
4855 /*
4856  * Return string "str" in ' quotes, doubling ' characters.
4857  * If "str" is NULL an empty string is assumed.
4858  * If "function" is TRUE make it function('string').
4859  */
4860     char_u *
4861 string_quote(char_u *str, int function)
4862 {
4863     unsigned	len;
4864     char_u	*p, *r, *s;
4865 
4866     len = (function ? 13 : 3);
4867     if (str != NULL)
4868     {
4869 	len += (unsigned)STRLEN(str);
4870 	for (p = str; *p != NUL; MB_PTR_ADV(p))
4871 	    if (*p == '\'')
4872 		++len;
4873     }
4874     s = r = alloc(len);
4875     if (r != NULL)
4876     {
4877 	if (function)
4878 	{
4879 	    STRCPY(r, "function('");
4880 	    r += 10;
4881 	}
4882 	else
4883 	    *r++ = '\'';
4884 	if (str != NULL)
4885 	    for (p = str; *p != NUL; )
4886 	    {
4887 		if (*p == '\'')
4888 		    *r++ = '\'';
4889 		MB_COPY_CHAR(p, r);
4890 	    }
4891 	*r++ = '\'';
4892 	if (function)
4893 	    *r++ = ')';
4894 	*r++ = NUL;
4895     }
4896     return s;
4897 }
4898 
4899 #if defined(FEAT_FLOAT) || defined(PROTO)
4900 /*
4901  * Convert the string "text" to a floating point number.
4902  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
4903  * this always uses a decimal point.
4904  * Returns the length of the text that was consumed.
4905  */
4906     int
4907 string2float(
4908     char_u	*text,
4909     float_T	*value)	    // result stored here
4910 {
4911     char	*s = (char *)text;
4912     float_T	f;
4913 
4914     // MS-Windows does not deal with "inf" and "nan" properly.
4915     if (STRNICMP(text, "inf", 3) == 0)
4916     {
4917 	*value = INFINITY;
4918 	return 3;
4919     }
4920     if (STRNICMP(text, "-inf", 3) == 0)
4921     {
4922 	*value = -INFINITY;
4923 	return 4;
4924     }
4925     if (STRNICMP(text, "nan", 3) == 0)
4926     {
4927 	*value = NAN;
4928 	return 3;
4929     }
4930     f = strtod(s, &s);
4931     *value = f;
4932     return (int)((char_u *)s - text);
4933 }
4934 #endif
4935 
4936 /*
4937  * Translate a String variable into a position.
4938  * Returns NULL when there is an error.
4939  */
4940     pos_T *
4941 var2fpos(
4942     typval_T	*varp,
4943     int		dollar_lnum,	// TRUE when $ is last line
4944     int		*fnum)		// set to fnum for '0, 'A, etc.
4945 {
4946     char_u		*name;
4947     static pos_T	pos;
4948     pos_T		*pp;
4949 
4950     // Argument can be [lnum, col, coladd].
4951     if (varp->v_type == VAR_LIST)
4952     {
4953 	list_T		*l;
4954 	int		len;
4955 	int		error = FALSE;
4956 	listitem_T	*li;
4957 
4958 	l = varp->vval.v_list;
4959 	if (l == NULL)
4960 	    return NULL;
4961 
4962 	// Get the line number
4963 	pos.lnum = list_find_nr(l, 0L, &error);
4964 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
4965 	    return NULL;	// invalid line number
4966 	len = (long)STRLEN(ml_get(pos.lnum));
4967 
4968 	// Get the column number
4969 	// We accept "$" for the column number: last column.
4970 	li = list_find(l, 1L);
4971 	if (li != NULL && li->li_tv.v_type == VAR_STRING
4972 		&& li->li_tv.vval.v_string != NULL
4973 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
4974 	{
4975 	    pos.col = len + 1;
4976 	}
4977 	else
4978 	{
4979 	    pos.col = list_find_nr(l, 1L, &error);
4980 	    if (error)
4981 		return NULL;
4982 	}
4983 
4984 	// Accept a position up to the NUL after the line.
4985 	if (pos.col == 0 || (int)pos.col > len + 1)
4986 	    return NULL;	// invalid column number
4987 	--pos.col;
4988 
4989 	// Get the virtual offset.  Defaults to zero.
4990 	pos.coladd = list_find_nr(l, 2L, &error);
4991 	if (error)
4992 	    pos.coladd = 0;
4993 
4994 	return &pos;
4995     }
4996 
4997     name = tv_get_string_chk(varp);
4998     if (name == NULL)
4999 	return NULL;
5000     if (name[0] == '.')				// cursor
5001 	return &curwin->w_cursor;
5002     if (name[0] == 'v' && name[1] == NUL)	// Visual start
5003     {
5004 	if (VIsual_active)
5005 	    return &VIsual;
5006 	return &curwin->w_cursor;
5007     }
5008     if (name[0] == '\'')			// mark
5009     {
5010 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
5011 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
5012 	    return NULL;
5013 	return pp;
5014     }
5015 
5016     pos.coladd = 0;
5017 
5018     if (name[0] == 'w' && dollar_lnum)
5019     {
5020 	pos.col = 0;
5021 	if (name[1] == '0')		// "w0": first visible line
5022 	{
5023 	    update_topline();
5024 	    // In silent Ex mode topline is zero, but that's not a valid line
5025 	    // number; use one instead.
5026 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
5027 	    return &pos;
5028 	}
5029 	else if (name[1] == '$')	// "w$": last visible line
5030 	{
5031 	    validate_botline();
5032 	    // In silent Ex mode botline is zero, return zero then.
5033 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
5034 	    return &pos;
5035 	}
5036     }
5037     else if (name[0] == '$')		// last column or line
5038     {
5039 	if (dollar_lnum)
5040 	{
5041 	    pos.lnum = curbuf->b_ml.ml_line_count;
5042 	    pos.col = 0;
5043 	}
5044 	else
5045 	{
5046 	    pos.lnum = curwin->w_cursor.lnum;
5047 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
5048 	}
5049 	return &pos;
5050     }
5051     return NULL;
5052 }
5053 
5054 /*
5055  * Convert list in "arg" into a position and optional file number.
5056  * When "fnump" is NULL there is no file number, only 3 items.
5057  * Note that the column is passed on as-is, the caller may want to decrement
5058  * it to use 1 for the first column.
5059  * Return FAIL when conversion is not possible, doesn't check the position for
5060  * validity.
5061  */
5062     int
5063 list2fpos(
5064     typval_T	*arg,
5065     pos_T	*posp,
5066     int		*fnump,
5067     colnr_T	*curswantp)
5068 {
5069     list_T	*l = arg->vval.v_list;
5070     long	i = 0;
5071     long	n;
5072 
5073     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
5074     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
5075     if (arg->v_type != VAR_LIST
5076 	    || l == NULL
5077 	    || l->lv_len < (fnump == NULL ? 2 : 3)
5078 	    || l->lv_len > (fnump == NULL ? 4 : 5))
5079 	return FAIL;
5080 
5081     if (fnump != NULL)
5082     {
5083 	n = list_find_nr(l, i++, NULL);	// fnum
5084 	if (n < 0)
5085 	    return FAIL;
5086 	if (n == 0)
5087 	    n = curbuf->b_fnum;		// current buffer
5088 	*fnump = n;
5089     }
5090 
5091     n = list_find_nr(l, i++, NULL);	// lnum
5092     if (n < 0)
5093 	return FAIL;
5094     posp->lnum = n;
5095 
5096     n = list_find_nr(l, i++, NULL);	// col
5097     if (n < 0)
5098 	return FAIL;
5099     posp->col = n;
5100 
5101     n = list_find_nr(l, i, NULL);	// off
5102     if (n < 0)
5103 	posp->coladd = 0;
5104     else
5105 	posp->coladd = n;
5106 
5107     if (curswantp != NULL)
5108 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
5109 
5110     return OK;
5111 }
5112 
5113 /*
5114  * Get the length of an environment variable name.
5115  * Advance "arg" to the first character after the name.
5116  * Return 0 for error.
5117  */
5118     int
5119 get_env_len(char_u **arg)
5120 {
5121     char_u	*p;
5122     int		len;
5123 
5124     for (p = *arg; vim_isIDc(*p); ++p)
5125 	;
5126     if (p == *arg)	    // no name found
5127 	return 0;
5128 
5129     len = (int)(p - *arg);
5130     *arg = p;
5131     return len;
5132 }
5133 
5134 /*
5135  * Get the length of the name of a function or internal variable.
5136  * "arg" is advanced to after the name.
5137  * Return 0 if something is wrong.
5138  */
5139     int
5140 get_id_len(char_u **arg)
5141 {
5142     char_u	*p;
5143     int		len;
5144 
5145     // Find the end of the name.
5146     for (p = *arg; eval_isnamec(*p); ++p)
5147     {
5148 	if (*p == ':')
5149 	{
5150 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5151 	    // slice "[n:]".  Also "xx:" is not a namespace.
5152 	    len = (int)(p - *arg);
5153 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
5154 		    || len > 1)
5155 		break;
5156 	}
5157     }
5158     if (p == *arg)	    // no name found
5159 	return 0;
5160 
5161     len = (int)(p - *arg);
5162     *arg = p;
5163 
5164     return len;
5165 }
5166 
5167 /*
5168  * Get the length of the name of a variable or function.
5169  * Only the name is recognized, does not handle ".key" or "[idx]".
5170  * "arg" is advanced to the first non-white character after the name.
5171  * Return -1 if curly braces expansion failed.
5172  * Return 0 if something else is wrong.
5173  * If the name contains 'magic' {}'s, expand them and return the
5174  * expanded name in an allocated string via 'alias' - caller must free.
5175  */
5176     int
5177 get_name_len(
5178     char_u	**arg,
5179     char_u	**alias,
5180     int		evaluate,
5181     int		verbose)
5182 {
5183     int		len;
5184     char_u	*p;
5185     char_u	*expr_start;
5186     char_u	*expr_end;
5187 
5188     *alias = NULL;  // default to no alias
5189 
5190     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
5191 						  && (*arg)[2] == (int)KE_SNR)
5192     {
5193 	// hard coded <SNR>, already translated
5194 	*arg += 3;
5195 	return get_id_len(arg) + 3;
5196     }
5197     len = eval_fname_script(*arg);
5198     if (len > 0)
5199     {
5200 	// literal "<SID>", "s:" or "<SNR>"
5201 	*arg += len;
5202     }
5203 
5204     /*
5205      * Find the end of the name; check for {} construction.
5206      */
5207     p = find_name_end(*arg, &expr_start, &expr_end,
5208 					       len > 0 ? 0 : FNE_CHECK_START);
5209     if (expr_start != NULL)
5210     {
5211 	char_u	*temp_string;
5212 
5213 	if (!evaluate)
5214 	{
5215 	    len += (int)(p - *arg);
5216 	    *arg = skipwhite(p);
5217 	    return len;
5218 	}
5219 
5220 	/*
5221 	 * Include any <SID> etc in the expanded string:
5222 	 * Thus the -len here.
5223 	 */
5224 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
5225 	if (temp_string == NULL)
5226 	    return -1;
5227 	*alias = temp_string;
5228 	*arg = skipwhite(p);
5229 	return (int)STRLEN(temp_string);
5230     }
5231 
5232     len += get_id_len(arg);
5233     // Only give an error when there is something, otherwise it will be
5234     // reported at a higher level.
5235     if (len == 0 && verbose && **arg != NUL)
5236 	semsg(_(e_invexpr2), *arg);
5237 
5238     return len;
5239 }
5240 
5241 /*
5242  * Find the end of a variable or function name, taking care of magic braces.
5243  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
5244  * start and end of the first magic braces item.
5245  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
5246  * Return a pointer to just after the name.  Equal to "arg" if there is no
5247  * valid name.
5248  */
5249     char_u *
5250 find_name_end(
5251     char_u	*arg,
5252     char_u	**expr_start,
5253     char_u	**expr_end,
5254     int		flags)
5255 {
5256     int		mb_nest = 0;
5257     int		br_nest = 0;
5258     char_u	*p;
5259     int		len;
5260     int		vim9script = in_vim9script();
5261 
5262     if (expr_start != NULL)
5263     {
5264 	*expr_start = NULL;
5265 	*expr_end = NULL;
5266     }
5267 
5268     // Quick check for valid starting character.
5269     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg)
5270 						&& (*arg != '{' || vim9script))
5271 	return arg;
5272 
5273     for (p = arg; *p != NUL
5274 		    && (eval_isnamec(*p)
5275 			|| (*p == '{' && !vim9script)
5276 			|| ((flags & FNE_INCL_BR) && (*p == '['
5277 					 || (*p == '.' && eval_isdictc(p[1]))))
5278 			|| mb_nest != 0
5279 			|| br_nest != 0); MB_PTR_ADV(p))
5280     {
5281 	if (*p == '\'')
5282 	{
5283 	    // skip over 'string' to avoid counting [ and ] inside it.
5284 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5285 		;
5286 	    if (*p == NUL)
5287 		break;
5288 	}
5289 	else if (*p == '"')
5290 	{
5291 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
5292 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5293 		if (*p == '\\' && p[1] != NUL)
5294 		    ++p;
5295 	    if (*p == NUL)
5296 		break;
5297 	}
5298 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5299 	{
5300 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5301 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
5302 	    len = (int)(p - arg);
5303 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5304 		    || (len > 1 && p[-1] != '}'))
5305 		break;
5306 	}
5307 
5308 	if (mb_nest == 0)
5309 	{
5310 	    if (*p == '[')
5311 		++br_nest;
5312 	    else if (*p == ']')
5313 		--br_nest;
5314 	}
5315 
5316 	if (br_nest == 0 && !vim9script)
5317 	{
5318 	    if (*p == '{')
5319 	    {
5320 		mb_nest++;
5321 		if (expr_start != NULL && *expr_start == NULL)
5322 		    *expr_start = p;
5323 	    }
5324 	    else if (*p == '}')
5325 	    {
5326 		mb_nest--;
5327 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5328 		    *expr_end = p;
5329 	    }
5330 	}
5331     }
5332 
5333     return p;
5334 }
5335 
5336 /*
5337  * Expands out the 'magic' {}'s in a variable/function name.
5338  * Note that this can call itself recursively, to deal with
5339  * constructs like foo{bar}{baz}{bam}
5340  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5341  *			"in_start"      ^
5342  *			"expr_start"	   ^
5343  *			"expr_end"		 ^
5344  *			"in_end"			    ^
5345  *
5346  * Returns a new allocated string, which the caller must free.
5347  * Returns NULL for failure.
5348  */
5349     static char_u *
5350 make_expanded_name(
5351     char_u	*in_start,
5352     char_u	*expr_start,
5353     char_u	*expr_end,
5354     char_u	*in_end)
5355 {
5356     char_u	c1;
5357     char_u	*retval = NULL;
5358     char_u	*temp_result;
5359 
5360     if (expr_end == NULL || in_end == NULL)
5361 	return NULL;
5362     *expr_start	= NUL;
5363     *expr_end = NUL;
5364     c1 = *in_end;
5365     *in_end = NUL;
5366 
5367     temp_result = eval_to_string(expr_start + 1, FALSE);
5368     if (temp_result != NULL)
5369     {
5370 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5371 						   + (in_end - expr_end) + 1);
5372 	if (retval != NULL)
5373 	{
5374 	    STRCPY(retval, in_start);
5375 	    STRCAT(retval, temp_result);
5376 	    STRCAT(retval, expr_end + 1);
5377 	}
5378     }
5379     vim_free(temp_result);
5380 
5381     *in_end = c1;		// put char back for error messages
5382     *expr_start = '{';
5383     *expr_end = '}';
5384 
5385     if (retval != NULL)
5386     {
5387 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5388 	if (expr_start != NULL)
5389 	{
5390 	    // Further expansion!
5391 	    temp_result = make_expanded_name(retval, expr_start,
5392 						       expr_end, temp_result);
5393 	    vim_free(retval);
5394 	    retval = temp_result;
5395 	}
5396     }
5397 
5398     return retval;
5399 }
5400 
5401 /*
5402  * Return TRUE if character "c" can be used in a variable or function name.
5403  * Does not include '{' or '}' for magic braces.
5404  */
5405     int
5406 eval_isnamec(int c)
5407 {
5408     return ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR;
5409 }
5410 
5411 /*
5412  * Return TRUE if character "c" can be used as the first character in a
5413  * variable or function name (excluding '{' and '}').
5414  */
5415     int
5416 eval_isnamec1(int c)
5417 {
5418     return ASCII_ISALPHA(c) || c == '_';
5419 }
5420 
5421 /*
5422  * Return TRUE if character "c" can be used as the first character of a
5423  * dictionary key.
5424  */
5425     int
5426 eval_isdictc(int c)
5427 {
5428     return ASCII_ISALNUM(c) || c == '_';
5429 }
5430 
5431 /*
5432  * Return the character "str[index]" where "index" is the character index.  If
5433  * "index" is out of range NULL is returned.
5434  */
5435     char_u *
5436 char_from_string(char_u *str, varnumber_T index)
5437 {
5438     size_t	    nbyte = 0;
5439     varnumber_T	    nchar = index;
5440     size_t	    slen;
5441 
5442     if (str == NULL || index < 0)
5443 	return NULL;
5444     slen = STRLEN(str);
5445     while (nchar > 0 && nbyte < slen)
5446     {
5447 	nbyte += MB_CPTR2LEN(str + nbyte);
5448 	--nchar;
5449     }
5450     if (nbyte >= slen)
5451 	return NULL;
5452     return vim_strnsave(str + nbyte, MB_CPTR2LEN(str + nbyte));
5453 }
5454 
5455 /*
5456  * Get the byte index for character index "idx" in string "str" with length
5457  * "str_len".
5458  * If going over the end return "str_len".
5459  * If "idx" is negative count from the end, -1 is the last character.
5460  * When going over the start return -1.
5461  */
5462     static long
5463 char_idx2byte(char_u *str, size_t str_len, varnumber_T idx)
5464 {
5465     varnumber_T nchar = idx;
5466     size_t	nbyte = 0;
5467 
5468     if (nchar >= 0)
5469     {
5470 	while (nchar > 0 && nbyte < str_len)
5471 	{
5472 	    nbyte += MB_CPTR2LEN(str + nbyte);
5473 	    --nchar;
5474 	}
5475     }
5476     else
5477     {
5478 	nbyte = str_len;
5479 	while (nchar < 0 && nbyte > 0)
5480 	{
5481 	    --nbyte;
5482 	    nbyte -= mb_head_off(str, str + nbyte);
5483 	    ++nchar;
5484 	}
5485 	if (nchar < 0)
5486 	    return -1;
5487     }
5488     return (long)nbyte;
5489 }
5490 
5491 /*
5492  * Return the slice "str[first:last]" using character indexes.
5493  * Return NULL when the result is empty.
5494  */
5495     char_u *
5496 string_slice(char_u *str, varnumber_T first, varnumber_T last)
5497 {
5498     long	start_byte, end_byte;
5499     size_t	slen;
5500 
5501     if (str == NULL)
5502 	return NULL;
5503     slen = STRLEN(str);
5504     start_byte = char_idx2byte(str, slen, first);
5505     if (start_byte < 0)
5506 	start_byte = 0; // first index very negative: use zero
5507     if (last == -1)
5508 	end_byte = (long)slen;
5509     else
5510     {
5511 	end_byte = char_idx2byte(str, slen, last);
5512 	if (end_byte >= 0 && end_byte < (long)slen)
5513 	    // end index is inclusive
5514 	    end_byte += MB_CPTR2LEN(str + end_byte);
5515     }
5516 
5517     if (start_byte >= (long)slen || end_byte <= start_byte)
5518 	return NULL;
5519     return vim_strnsave(str + start_byte, end_byte - start_byte);
5520 }
5521 
5522 /*
5523  * Handle:
5524  * - expr[expr], expr[expr:expr] subscript
5525  * - ".name" lookup
5526  * - function call with Funcref variable: func(expr)
5527  * - method call: var->method()
5528  *
5529  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5530  */
5531     int
5532 handle_subscript(
5533     char_u	**arg,
5534     typval_T	*rettv,
5535     evalarg_T	*evalarg,
5536     int		verbose)	// give error messages
5537 {
5538     int		evaluate = evalarg != NULL
5539 				      && (evalarg->eval_flags & EVAL_EVALUATE);
5540     int		ret = OK;
5541     dict_T	*selfdict = NULL;
5542     int		check_white = TRUE;
5543     int		getnext;
5544     char_u	*p;
5545 
5546     while (ret == OK)
5547     {
5548 	// When at the end of the line and ".name" or "->{" or "->X" follows in
5549 	// the next line then consume the line break.
5550 	p = eval_next_non_blank(*arg, evalarg, &getnext);
5551 	if (getnext
5552 	    && ((rettv->v_type == VAR_DICT && *p == '.' && eval_isdictc(p[1]))
5553 		|| (p[0] == '-' && p[1] == '>'
5554 				     && (p[2] == '{' || ASCII_ISALPHA(p[2])))))
5555 	{
5556 	    *arg = eval_next_line(evalarg);
5557 	    p = *arg;
5558 	    check_white = FALSE;
5559 	}
5560 
5561 	if ((**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5562 			    || rettv->v_type == VAR_PARTIAL))
5563 		    && (!check_white || !VIM_ISWHITE(*(*arg - 1))))
5564 	{
5565 	    ret = call_func_rettv(arg, evalarg, rettv, evaluate,
5566 							       selfdict, NULL);
5567 
5568 	    // Stop the expression evaluation when immediately aborting on
5569 	    // error, or when an interrupt occurred or an exception was thrown
5570 	    // but not caught.
5571 	    if (aborting())
5572 	    {
5573 		if (ret == OK)
5574 		    clear_tv(rettv);
5575 		ret = FAIL;
5576 	    }
5577 	    dict_unref(selfdict);
5578 	    selfdict = NULL;
5579 	}
5580 	else if (p[0] == '-' && p[1] == '>')
5581 	{
5582 	    *arg = p;
5583 	    if (ret == OK)
5584 	    {
5585 		if ((*arg)[2] == '{')
5586 		    // expr->{lambda}()
5587 		    ret = eval_lambda(arg, rettv, evalarg, verbose);
5588 		else
5589 		    // expr->name()
5590 		    ret = eval_method(arg, rettv, evalarg, verbose);
5591 	    }
5592 	}
5593 	// "." is ".name" lookup when we found a dict or when evaluating and
5594 	// scriptversion is at least 2, where string concatenation is "..".
5595 	else if (**arg == '['
5596 		|| (**arg == '.' && (rettv->v_type == VAR_DICT
5597 			|| (!evaluate
5598 			    && (*arg)[1] != '.'
5599 			    && current_sctx.sc_version >= 2))))
5600 	{
5601 	    dict_unref(selfdict);
5602 	    if (rettv->v_type == VAR_DICT)
5603 	    {
5604 		selfdict = rettv->vval.v_dict;
5605 		if (selfdict != NULL)
5606 		    ++selfdict->dv_refcount;
5607 	    }
5608 	    else
5609 		selfdict = NULL;
5610 	    if (eval_index(arg, rettv, evalarg, verbose) == FAIL)
5611 	    {
5612 		clear_tv(rettv);
5613 		ret = FAIL;
5614 	    }
5615 	}
5616 	else
5617 	    break;
5618     }
5619 
5620     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5621     // Don't do this when "Func" is already a partial that was bound
5622     // explicitly (pt_auto is FALSE).
5623     if (selfdict != NULL
5624 	    && (rettv->v_type == VAR_FUNC
5625 		|| (rettv->v_type == VAR_PARTIAL
5626 		    && (rettv->vval.v_partial->pt_auto
5627 			|| rettv->vval.v_partial->pt_dict == NULL))))
5628 	selfdict = make_partial(selfdict, rettv);
5629 
5630     dict_unref(selfdict);
5631     return ret;
5632 }
5633 
5634 /*
5635  * Make a copy of an item.
5636  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5637  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5638  * reference to an already copied list/dict can be used.
5639  * Returns FAIL or OK.
5640  */
5641     int
5642 item_copy(
5643     typval_T	*from,
5644     typval_T	*to,
5645     int		deep,
5646     int		copyID)
5647 {
5648     static int	recurse = 0;
5649     int		ret = OK;
5650 
5651     if (recurse >= DICT_MAXNEST)
5652     {
5653 	emsg(_("E698: variable nested too deep for making a copy"));
5654 	return FAIL;
5655     }
5656     ++recurse;
5657 
5658     switch (from->v_type)
5659     {
5660 	case VAR_NUMBER:
5661 	case VAR_FLOAT:
5662 	case VAR_STRING:
5663 	case VAR_FUNC:
5664 	case VAR_PARTIAL:
5665 	case VAR_BOOL:
5666 	case VAR_SPECIAL:
5667 	case VAR_JOB:
5668 	case VAR_CHANNEL:
5669 	    copy_tv(from, to);
5670 	    break;
5671 	case VAR_LIST:
5672 	    to->v_type = VAR_LIST;
5673 	    to->v_lock = 0;
5674 	    if (from->vval.v_list == NULL)
5675 		to->vval.v_list = NULL;
5676 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
5677 	    {
5678 		// use the copy made earlier
5679 		to->vval.v_list = from->vval.v_list->lv_copylist;
5680 		++to->vval.v_list->lv_refcount;
5681 	    }
5682 	    else
5683 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
5684 	    if (to->vval.v_list == NULL)
5685 		ret = FAIL;
5686 	    break;
5687 	case VAR_BLOB:
5688 	    ret = blob_copy(from->vval.v_blob, to);
5689 	    break;
5690 	case VAR_DICT:
5691 	    to->v_type = VAR_DICT;
5692 	    to->v_lock = 0;
5693 	    if (from->vval.v_dict == NULL)
5694 		to->vval.v_dict = NULL;
5695 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
5696 	    {
5697 		// use the copy made earlier
5698 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
5699 		++to->vval.v_dict->dv_refcount;
5700 	    }
5701 	    else
5702 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
5703 	    if (to->vval.v_dict == NULL)
5704 		ret = FAIL;
5705 	    break;
5706 	case VAR_UNKNOWN:
5707 	case VAR_ANY:
5708 	case VAR_VOID:
5709 	    internal_error_no_abort("item_copy(UNKNOWN)");
5710 	    ret = FAIL;
5711     }
5712     --recurse;
5713     return ret;
5714 }
5715 
5716     void
5717 echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr)
5718 {
5719     char_u	*tofree;
5720     char_u	numbuf[NUMBUFLEN];
5721     char_u	*p = echo_string(rettv, &tofree, numbuf, get_copyID());
5722 
5723     if (*atstart)
5724     {
5725 	*atstart = FALSE;
5726 	// Call msg_start() after eval1(), evaluating the expression
5727 	// may cause a message to appear.
5728 	if (with_space)
5729 	{
5730 	    // Mark the saved text as finishing the line, so that what
5731 	    // follows is displayed on a new line when scrolling back
5732 	    // at the more prompt.
5733 	    msg_sb_eol();
5734 	    msg_start();
5735 	}
5736     }
5737     else if (with_space)
5738 	msg_puts_attr(" ", echo_attr);
5739 
5740     if (p != NULL)
5741 	for ( ; *p != NUL && !got_int; ++p)
5742 	{
5743 	    if (*p == '\n' || *p == '\r' || *p == TAB)
5744 	    {
5745 		if (*p != TAB && *needclr)
5746 		{
5747 		    // remove any text still there from the command
5748 		    msg_clr_eos();
5749 		    *needclr = FALSE;
5750 		}
5751 		msg_putchar_attr(*p, echo_attr);
5752 	    }
5753 	    else
5754 	    {
5755 		if (has_mbyte)
5756 		{
5757 		    int i = (*mb_ptr2len)(p);
5758 
5759 		    (void)msg_outtrans_len_attr(p, i, echo_attr);
5760 		    p += i - 1;
5761 		}
5762 		else
5763 		    (void)msg_outtrans_len_attr(p, 1, echo_attr);
5764 	    }
5765 	}
5766     vim_free(tofree);
5767 }
5768 
5769 /*
5770  * ":echo expr1 ..."	print each argument separated with a space, add a
5771  *			newline at the end.
5772  * ":echon expr1 ..."	print each argument plain.
5773  */
5774     void
5775 ex_echo(exarg_T *eap)
5776 {
5777     char_u	*arg = eap->arg;
5778     typval_T	rettv;
5779     char_u	*p;
5780     int		needclr = TRUE;
5781     int		atstart = TRUE;
5782     int		did_emsg_before = did_emsg;
5783     int		called_emsg_before = called_emsg;
5784     evalarg_T	evalarg;
5785 
5786     fill_evalarg_from_eap(&evalarg, eap, eap->skip);
5787 
5788     if (eap->skip)
5789 	++emsg_skip;
5790     while ((!ends_excmd2(eap->cmd, arg) || *arg == '"') && !got_int)
5791     {
5792 	// If eval1() causes an error message the text from the command may
5793 	// still need to be cleared. E.g., "echo 22,44".
5794 	need_clr_eos = needclr;
5795 
5796 	p = arg;
5797 	if (eval1(&arg, &rettv, &evalarg) == FAIL)
5798 	{
5799 	    /*
5800 	     * Report the invalid expression unless the expression evaluation
5801 	     * has been cancelled due to an aborting error, an interrupt, or an
5802 	     * exception.
5803 	     */
5804 	    if (!aborting() && did_emsg == did_emsg_before
5805 					  && called_emsg == called_emsg_before)
5806 		semsg(_(e_invexpr2), p);
5807 	    need_clr_eos = FALSE;
5808 	    break;
5809 	}
5810 	need_clr_eos = FALSE;
5811 
5812 	if (!eap->skip)
5813 	    echo_one(&rettv, eap->cmdidx == CMD_echo, &atstart, &needclr);
5814 
5815 	clear_tv(&rettv);
5816 	arg = skipwhite(arg);
5817     }
5818     eap->nextcmd = check_nextcmd(arg);
5819     clear_evalarg(&evalarg, eap);
5820 
5821     if (eap->skip)
5822 	--emsg_skip;
5823     else
5824     {
5825 	// remove text that may still be there from the command
5826 	if (needclr)
5827 	    msg_clr_eos();
5828 	if (eap->cmdidx == CMD_echo)
5829 	    msg_end();
5830     }
5831 }
5832 
5833 /*
5834  * ":echohl {name}".
5835  */
5836     void
5837 ex_echohl(exarg_T *eap)
5838 {
5839     echo_attr = syn_name2attr(eap->arg);
5840 }
5841 
5842 /*
5843  * Returns the :echo attribute
5844  */
5845     int
5846 get_echo_attr(void)
5847 {
5848     return echo_attr;
5849 }
5850 
5851 /*
5852  * ":execute expr1 ..."	execute the result of an expression.
5853  * ":echomsg expr1 ..."	Print a message
5854  * ":echoerr expr1 ..."	Print an error
5855  * Each gets spaces around each argument and a newline at the end for
5856  * echo commands
5857  */
5858     void
5859 ex_execute(exarg_T *eap)
5860 {
5861     char_u	*arg = eap->arg;
5862     typval_T	rettv;
5863     int		ret = OK;
5864     char_u	*p;
5865     garray_T	ga;
5866     int		len;
5867 
5868     ga_init2(&ga, 1, 80);
5869 
5870     if (eap->skip)
5871 	++emsg_skip;
5872     while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
5873     {
5874 	ret = eval1_emsg(&arg, &rettv, eap);
5875 	if (ret == FAIL)
5876 	    break;
5877 
5878 	if (!eap->skip)
5879 	{
5880 	    char_u   buf[NUMBUFLEN];
5881 
5882 	    if (eap->cmdidx == CMD_execute)
5883 	    {
5884 		if (rettv.v_type == VAR_CHANNEL || rettv.v_type == VAR_JOB)
5885 		{
5886 		    emsg(_(e_inval_string));
5887 		    p = NULL;
5888 		}
5889 		else
5890 		    p = tv_get_string_buf(&rettv, buf);
5891 	    }
5892 	    else
5893 		p = tv_stringify(&rettv, buf);
5894 	    if (p == NULL)
5895 	    {
5896 		clear_tv(&rettv);
5897 		ret = FAIL;
5898 		break;
5899 	    }
5900 	    len = (int)STRLEN(p);
5901 	    if (ga_grow(&ga, len + 2) == FAIL)
5902 	    {
5903 		clear_tv(&rettv);
5904 		ret = FAIL;
5905 		break;
5906 	    }
5907 	    if (ga.ga_len)
5908 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
5909 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
5910 	    ga.ga_len += len;
5911 	}
5912 
5913 	clear_tv(&rettv);
5914 	arg = skipwhite(arg);
5915     }
5916 
5917     if (ret != FAIL && ga.ga_data != NULL)
5918     {
5919 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
5920 	{
5921 	    // Mark the already saved text as finishing the line, so that what
5922 	    // follows is displayed on a new line when scrolling back at the
5923 	    // more prompt.
5924 	    msg_sb_eol();
5925 	}
5926 
5927 	if (eap->cmdidx == CMD_echomsg)
5928 	{
5929 	    msg_attr(ga.ga_data, echo_attr);
5930 	    out_flush();
5931 	}
5932 	else if (eap->cmdidx == CMD_echoerr)
5933 	{
5934 	    int		save_did_emsg = did_emsg;
5935 
5936 	    // We don't want to abort following commands, restore did_emsg.
5937 	    emsg(ga.ga_data);
5938 	    if (!force_abort)
5939 		did_emsg = save_did_emsg;
5940 	}
5941 	else if (eap->cmdidx == CMD_execute)
5942 	    do_cmdline((char_u *)ga.ga_data,
5943 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
5944     }
5945 
5946     ga_clear(&ga);
5947 
5948     if (eap->skip)
5949 	--emsg_skip;
5950 
5951     eap->nextcmd = check_nextcmd(arg);
5952 }
5953 
5954 /*
5955  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
5956  * "arg" points to the "&" or '+' when called, to "option" when returning.
5957  * Returns NULL when no option name found.  Otherwise pointer to the char
5958  * after the option name.
5959  */
5960     char_u *
5961 find_option_end(char_u **arg, int *opt_flags)
5962 {
5963     char_u	*p = *arg;
5964 
5965     ++p;
5966     if (*p == 'g' && p[1] == ':')
5967     {
5968 	*opt_flags = OPT_GLOBAL;
5969 	p += 2;
5970     }
5971     else if (*p == 'l' && p[1] == ':')
5972     {
5973 	*opt_flags = OPT_LOCAL;
5974 	p += 2;
5975     }
5976     else
5977 	*opt_flags = 0;
5978 
5979     if (!ASCII_ISALPHA(*p))
5980 	return NULL;
5981     *arg = p;
5982 
5983     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
5984 	p += 4;	    // termcap option
5985     else
5986 	while (ASCII_ISALPHA(*p))
5987 	    ++p;
5988     return p;
5989 }
5990 
5991 /*
5992  * Display script name where an item was last set.
5993  * Should only be invoked when 'verbose' is non-zero.
5994  */
5995     void
5996 last_set_msg(sctx_T script_ctx)
5997 {
5998     char_u *p;
5999 
6000     if (script_ctx.sc_sid != 0)
6001     {
6002 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
6003 	if (p != NULL)
6004 	{
6005 	    verbose_enter();
6006 	    msg_puts(_("\n\tLast set from "));
6007 	    msg_puts((char *)p);
6008 	    if (script_ctx.sc_lnum > 0)
6009 	    {
6010 		msg_puts(_(line_msg));
6011 		msg_outnum((long)script_ctx.sc_lnum);
6012 	    }
6013 	    verbose_leave();
6014 	    vim_free(p);
6015 	}
6016     }
6017 }
6018 
6019 #endif // FEAT_EVAL
6020 
6021 /*
6022  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
6023  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
6024  * "flags" can be "g" to do a global substitute.
6025  * Returns an allocated string, NULL for error.
6026  */
6027     char_u *
6028 do_string_sub(
6029     char_u	*str,
6030     char_u	*pat,
6031     char_u	*sub,
6032     typval_T	*expr,
6033     char_u	*flags)
6034 {
6035     int		sublen;
6036     regmatch_T	regmatch;
6037     int		i;
6038     int		do_all;
6039     char_u	*tail;
6040     char_u	*end;
6041     garray_T	ga;
6042     char_u	*ret;
6043     char_u	*save_cpo;
6044     char_u	*zero_width = NULL;
6045 
6046     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
6047     save_cpo = p_cpo;
6048     p_cpo = empty_option;
6049 
6050     ga_init2(&ga, 1, 200);
6051 
6052     do_all = (flags[0] == 'g');
6053 
6054     regmatch.rm_ic = p_ic;
6055     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
6056     if (regmatch.regprog != NULL)
6057     {
6058 	tail = str;
6059 	end = str + STRLEN(str);
6060 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
6061 	{
6062 	    // Skip empty match except for first match.
6063 	    if (regmatch.startp[0] == regmatch.endp[0])
6064 	    {
6065 		if (zero_width == regmatch.startp[0])
6066 		{
6067 		    // avoid getting stuck on a match with an empty string
6068 		    i = mb_ptr2len(tail);
6069 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
6070 								   (size_t)i);
6071 		    ga.ga_len += i;
6072 		    tail += i;
6073 		    continue;
6074 		}
6075 		zero_width = regmatch.startp[0];
6076 	    }
6077 
6078 	    /*
6079 	     * Get some space for a temporary buffer to do the substitution
6080 	     * into.  It will contain:
6081 	     * - The text up to where the match is.
6082 	     * - The substituted text.
6083 	     * - The text after the match.
6084 	     */
6085 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
6086 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
6087 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
6088 	    {
6089 		ga_clear(&ga);
6090 		break;
6091 	    }
6092 
6093 	    // copy the text up to where the match is
6094 	    i = (int)(regmatch.startp[0] - tail);
6095 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
6096 	    // add the substituted text
6097 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
6098 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
6099 	    ga.ga_len += i + sublen - 1;
6100 	    tail = regmatch.endp[0];
6101 	    if (*tail == NUL)
6102 		break;
6103 	    if (!do_all)
6104 		break;
6105 	}
6106 
6107 	if (ga.ga_data != NULL)
6108 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
6109 
6110 	vim_regfree(regmatch.regprog);
6111     }
6112 
6113     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
6114     ga_clear(&ga);
6115     if (p_cpo == empty_option)
6116 	p_cpo = save_cpo;
6117     else
6118 	// Darn, evaluating {sub} expression or {expr} changed the value.
6119 	free_string_option(save_cpo);
6120 
6121     return ret;
6122 }
6123