xref: /vim-8.2.3635/src/eval.c (revision f4b68e90)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * eval.c: Expression evaluation.
12  */
13 #define USING_FLOAT_STUFF
14 
15 #include "vim.h"
16 
17 #if defined(FEAT_EVAL) || defined(PROTO)
18 
19 #ifdef VMS
20 # include <float.h>
21 #endif
22 
23 static char *e_dictrange = N_("E719: Cannot use [:] with a Dictionary");
24 #ifdef FEAT_FLOAT
25 static char *e_float_as_string = N_("E806: using Float as a String");
26 #endif
27 
28 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
29 
30 /*
31  * When recursively copying lists and dicts we need to remember which ones we
32  * have done to avoid endless recursiveness.  This unique ID is used for that.
33  * The last bit is used for previous_funccal, ignored when comparing.
34  */
35 static int current_copyID = 0;
36 
37 /*
38  * Info used by a ":for" loop.
39  */
40 typedef struct
41 {
42     int		fi_semicolon;	// TRUE if ending in '; var]'
43     int		fi_varcount;	// nr of variables in the list
44     listwatch_T	fi_lw;		// keep an eye on the item used.
45     list_T	*fi_list;	// list being used
46     int		fi_bi;		// index of blob
47     blob_T	*fi_blob;	// blob being used
48 } forinfo_T;
49 
50 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
51 static int eval2(char_u **arg, typval_T *rettv, int flags);
52 static int eval3(char_u **arg, typval_T *rettv, int flags);
53 static int eval4(char_u **arg, typval_T *rettv, int flags);
54 static int eval5(char_u **arg, typval_T *rettv, int flags);
55 static int eval6(char_u **arg, typval_T *rettv, int flags, int want_string);
56 static int eval7(char_u **arg, typval_T *rettv, int flags, int want_string);
57 static int eval7_leader(typval_T *rettv, char_u *start_leader, char_u **end_leaderp);
58 
59 static int free_unref_items(int copyID);
60 static char_u *make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
61 static int tv_check_lock(typval_T *tv, char_u *name, int use_gettext);
62 
63 /*
64  * Return "n1" divided by "n2", taking care of dividing by zero.
65  */
66 	varnumber_T
67 num_divide(varnumber_T n1, varnumber_T n2)
68 {
69     varnumber_T	result;
70 
71     if (n2 == 0)	// give an error message?
72     {
73 	if (n1 == 0)
74 	    result = VARNUM_MIN; // similar to NaN
75 	else if (n1 < 0)
76 	    result = -VARNUM_MAX;
77 	else
78 	    result = VARNUM_MAX;
79     }
80     else
81 	result = n1 / n2;
82 
83     return result;
84 }
85 
86 /*
87  * Return "n1" modulus "n2", taking care of dividing by zero.
88  */
89 	varnumber_T
90 num_modulus(varnumber_T n1, varnumber_T n2)
91 {
92     // Give an error when n2 is 0?
93     return (n2 == 0) ? 0 : (n1 % n2);
94 }
95 
96 #if defined(EBCDIC) || defined(PROTO)
97 /*
98  * Compare struct fst by function name.
99  */
100     static int
101 compare_func_name(const void *s1, const void *s2)
102 {
103     struct fst *p1 = (struct fst *)s1;
104     struct fst *p2 = (struct fst *)s2;
105 
106     return STRCMP(p1->f_name, p2->f_name);
107 }
108 
109 /*
110  * Sort the function table by function name.
111  * The sorting of the table above is ASCII dependent.
112  * On machines using EBCDIC we have to sort it.
113  */
114     static void
115 sortFunctions(void)
116 {
117     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
118 
119     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
120 }
121 #endif
122 
123 /*
124  * Initialize the global and v: variables.
125  */
126     void
127 eval_init(void)
128 {
129     evalvars_init();
130     func_init();
131 
132 #ifdef EBCDIC
133     /*
134      * Sort the function table, to enable binary search.
135      */
136     sortFunctions();
137 #endif
138 }
139 
140 #if defined(EXITFREE) || defined(PROTO)
141     void
142 eval_clear(void)
143 {
144     evalvars_clear();
145     free_scriptnames();  // must come after evalvars_clear().
146     free_locales();
147 
148     // autoloaded script names
149     free_autoload_scriptnames();
150 
151     // unreferenced lists and dicts
152     (void)garbage_collect(FALSE);
153 
154     // functions not garbage collected
155     free_all_functions();
156 }
157 #endif
158 
159 /*
160  * Top level evaluation function, returning a boolean.
161  * Sets "error" to TRUE if there was an error.
162  * Return TRUE or FALSE.
163  */
164     int
165 eval_to_bool(
166     char_u	*arg,
167     int		*error,
168     char_u	**nextcmd,
169     int		skip)	    // only parse, don't execute
170 {
171     typval_T	tv;
172     varnumber_T	retval = FALSE;
173 
174     if (skip)
175 	++emsg_skip;
176     if (eval0(arg, &tv, nextcmd, skip ? 0 : EVAL_EVALUATE) == FAIL)
177 	*error = TRUE;
178     else
179     {
180 	*error = FALSE;
181 	if (!skip)
182 	{
183 	    retval = (tv_get_number_chk(&tv, error) != 0);
184 	    clear_tv(&tv);
185 	}
186     }
187     if (skip)
188 	--emsg_skip;
189 
190     return (int)retval;
191 }
192 
193 /*
194  * Call eval1() and give an error message if not done at a lower level.
195  */
196     static int
197 eval1_emsg(char_u **arg, typval_T *rettv, int evaluate)
198 {
199     char_u	*start = *arg;
200     int		ret;
201     int		did_emsg_before = did_emsg;
202     int		called_emsg_before = called_emsg;
203 
204     ret = eval1(arg, rettv, evaluate ? EVAL_EVALUATE : 0);
205     if (ret == FAIL)
206     {
207 	// Report the invalid expression unless the expression evaluation has
208 	// been cancelled due to an aborting error, an interrupt, or an
209 	// exception, or we already gave a more specific error.
210 	// Also check called_emsg for when using assert_fails().
211 	if (!aborting() && did_emsg == did_emsg_before
212 					  && called_emsg == called_emsg_before)
213 	    semsg(_(e_invexpr2), start);
214     }
215     return ret;
216 }
217 
218 /*
219  * Evaluate an expression, which can be a function, partial or string.
220  * Pass arguments "argv[argc]".
221  * Return the result in "rettv" and OK or FAIL.
222  */
223     int
224 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
225 {
226     char_u	*s;
227     char_u	buf[NUMBUFLEN];
228     funcexe_T	funcexe;
229 
230     if (expr->v_type == VAR_FUNC)
231     {
232 	s = expr->vval.v_string;
233 	if (s == NULL || *s == NUL)
234 	    return FAIL;
235 	CLEAR_FIELD(funcexe);
236 	funcexe.evaluate = TRUE;
237 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
238 	    return FAIL;
239     }
240     else if (expr->v_type == VAR_PARTIAL)
241     {
242 	partial_T   *partial = expr->vval.v_partial;
243 
244 	if (partial == NULL)
245 	    return FAIL;
246 
247 	if (partial->pt_func != NULL
248 			  && partial->pt_func->uf_dfunc_idx != UF_NOT_COMPILED)
249 	{
250 	    if (call_def_function(partial->pt_func, argc, argv,
251 						       partial, rettv) == FAIL)
252 		return FAIL;
253 	}
254 	else
255 	{
256 	    s = partial_name(partial);
257 	    if (s == NULL || *s == NUL)
258 		return FAIL;
259 	    CLEAR_FIELD(funcexe);
260 	    funcexe.evaluate = TRUE;
261 	    funcexe.partial = partial;
262 	    if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
263 		return FAIL;
264 	}
265     }
266     else
267     {
268 	s = tv_get_string_buf_chk(expr, buf);
269 	if (s == NULL)
270 	    return FAIL;
271 	s = skipwhite(s);
272 	if (eval1_emsg(&s, rettv, TRUE) == FAIL)
273 	    return FAIL;
274 	if (*s != NUL)  // check for trailing chars after expr
275 	{
276 	    clear_tv(rettv);
277 	    semsg(_(e_invexpr2), s);
278 	    return FAIL;
279 	}
280     }
281     return OK;
282 }
283 
284 /*
285  * Like eval_to_bool() but using a typval_T instead of a string.
286  * Works for string, funcref and partial.
287  */
288     int
289 eval_expr_to_bool(typval_T *expr, int *error)
290 {
291     typval_T	rettv;
292     int		res;
293 
294     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
295     {
296 	*error = TRUE;
297 	return FALSE;
298     }
299     res = (tv_get_number_chk(&rettv, error) != 0);
300     clear_tv(&rettv);
301     return res;
302 }
303 
304 /*
305  * Top level evaluation function, returning a string.  If "skip" is TRUE,
306  * only parsing to "nextcmd" is done, without reporting errors.  Return
307  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
308  */
309     char_u *
310 eval_to_string_skip(
311     char_u	*arg,
312     char_u	**nextcmd,
313     int		skip)	    // only parse, don't execute
314 {
315     typval_T	tv;
316     char_u	*retval;
317 
318     if (skip)
319 	++emsg_skip;
320     if (eval0(arg, &tv, nextcmd, skip ? 0 : EVAL_EVALUATE) == FAIL || skip)
321 	retval = NULL;
322     else
323     {
324 	retval = vim_strsave(tv_get_string(&tv));
325 	clear_tv(&tv);
326     }
327     if (skip)
328 	--emsg_skip;
329 
330     return retval;
331 }
332 
333 /*
334  * Skip over an expression at "*pp".
335  * Return FAIL for an error, OK otherwise.
336  */
337     int
338 skip_expr(char_u **pp)
339 {
340     typval_T	rettv;
341 
342     *pp = skipwhite(*pp);
343     return eval1(pp, &rettv, 0);
344 }
345 
346 /*
347  * Top level evaluation function, returning a string.
348  * When "convert" is TRUE convert a List into a sequence of lines and convert
349  * a Float to a String.
350  * Return pointer to allocated memory, or NULL for failure.
351  */
352     char_u *
353 eval_to_string(
354     char_u	*arg,
355     char_u	**nextcmd,
356     int		convert)
357 {
358     typval_T	tv;
359     char_u	*retval;
360     garray_T	ga;
361 #ifdef FEAT_FLOAT
362     char_u	numbuf[NUMBUFLEN];
363 #endif
364 
365     if (eval0(arg, &tv, nextcmd, EVAL_EVALUATE) == FAIL)
366 	retval = NULL;
367     else
368     {
369 	if (convert && tv.v_type == VAR_LIST)
370 	{
371 	    ga_init2(&ga, (int)sizeof(char), 80);
372 	    if (tv.vval.v_list != NULL)
373 	    {
374 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
375 		if (tv.vval.v_list->lv_len > 0)
376 		    ga_append(&ga, NL);
377 	    }
378 	    ga_append(&ga, NUL);
379 	    retval = (char_u *)ga.ga_data;
380 	}
381 #ifdef FEAT_FLOAT
382 	else if (convert && tv.v_type == VAR_FLOAT)
383 	{
384 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
385 	    retval = vim_strsave(numbuf);
386 	}
387 #endif
388 	else
389 	    retval = vim_strsave(tv_get_string(&tv));
390 	clear_tv(&tv);
391     }
392 
393     return retval;
394 }
395 
396 /*
397  * Call eval_to_string() without using current local variables and using
398  * textwinlock.  When "use_sandbox" is TRUE use the sandbox.
399  */
400     char_u *
401 eval_to_string_safe(
402     char_u	*arg,
403     char_u	**nextcmd,
404     int		use_sandbox)
405 {
406     char_u	*retval;
407     funccal_entry_T funccal_entry;
408 
409     save_funccal(&funccal_entry);
410     if (use_sandbox)
411 	++sandbox;
412     ++textwinlock;
413     retval = eval_to_string(arg, nextcmd, FALSE);
414     if (use_sandbox)
415 	--sandbox;
416     --textwinlock;
417     restore_funccal();
418     return retval;
419 }
420 
421 /*
422  * Top level evaluation function, returning a number.
423  * Evaluates "expr" silently.
424  * Returns -1 for an error.
425  */
426     varnumber_T
427 eval_to_number(char_u *expr)
428 {
429     typval_T	rettv;
430     varnumber_T	retval;
431     char_u	*p = skipwhite(expr);
432 
433     ++emsg_off;
434 
435     if (eval1(&p, &rettv, EVAL_EVALUATE) == FAIL)
436 	retval = -1;
437     else
438     {
439 	retval = tv_get_number_chk(&rettv, NULL);
440 	clear_tv(&rettv);
441     }
442     --emsg_off;
443 
444     return retval;
445 }
446 
447 /*
448  * Top level evaluation function.
449  * Returns an allocated typval_T with the result.
450  * Returns NULL when there is an error.
451  */
452     typval_T *
453 eval_expr(char_u *arg, char_u **nextcmd)
454 {
455     typval_T	*tv;
456 
457     tv = ALLOC_ONE(typval_T);
458     if (tv != NULL && eval0(arg, tv, nextcmd, EVAL_EVALUATE) == FAIL)
459 	VIM_CLEAR(tv);
460 
461     return tv;
462 }
463 
464 /*
465  * Call some Vim script function and return the result in "*rettv".
466  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
467  * should have type VAR_UNKNOWN.
468  * Returns OK or FAIL.
469  */
470     int
471 call_vim_function(
472     char_u      *func,
473     int		argc,
474     typval_T	*argv,
475     typval_T	*rettv)
476 {
477     int		ret;
478     funcexe_T	funcexe;
479 
480     rettv->v_type = VAR_UNKNOWN;		// clear_tv() uses this
481     CLEAR_FIELD(funcexe);
482     funcexe.firstline = curwin->w_cursor.lnum;
483     funcexe.lastline = curwin->w_cursor.lnum;
484     funcexe.evaluate = TRUE;
485     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
486     if (ret == FAIL)
487 	clear_tv(rettv);
488 
489     return ret;
490 }
491 
492 /*
493  * Call Vim script function "func" and return the result as a number.
494  * Returns -1 when calling the function fails.
495  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
496  * have type VAR_UNKNOWN.
497  */
498     varnumber_T
499 call_func_retnr(
500     char_u      *func,
501     int		argc,
502     typval_T	*argv)
503 {
504     typval_T	rettv;
505     varnumber_T	retval;
506 
507     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
508 	return -1;
509 
510     retval = tv_get_number_chk(&rettv, NULL);
511     clear_tv(&rettv);
512     return retval;
513 }
514 
515 /*
516  * Call Vim script function "func" and return the result as a string.
517  * Returns NULL when calling the function fails.
518  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
519  * have type VAR_UNKNOWN.
520  */
521     void *
522 call_func_retstr(
523     char_u      *func,
524     int		argc,
525     typval_T	*argv)
526 {
527     typval_T	rettv;
528     char_u	*retval;
529 
530     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
531 	return NULL;
532 
533     retval = vim_strsave(tv_get_string(&rettv));
534     clear_tv(&rettv);
535     return retval;
536 }
537 
538 /*
539  * Call Vim script function "func" and return the result as a List.
540  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
541  * have type VAR_UNKNOWN.
542  * Returns NULL when there is something wrong.
543  */
544     void *
545 call_func_retlist(
546     char_u      *func,
547     int		argc,
548     typval_T	*argv)
549 {
550     typval_T	rettv;
551 
552     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
553 	return NULL;
554 
555     if (rettv.v_type != VAR_LIST)
556     {
557 	clear_tv(&rettv);
558 	return NULL;
559     }
560 
561     return rettv.vval.v_list;
562 }
563 
564 #ifdef FEAT_FOLDING
565 /*
566  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
567  * it in "*cp".  Doesn't give error messages.
568  */
569     int
570 eval_foldexpr(char_u *arg, int *cp)
571 {
572     typval_T	tv;
573     varnumber_T	retval;
574     char_u	*s;
575     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
576 								   OPT_LOCAL);
577 
578     ++emsg_off;
579     if (use_sandbox)
580 	++sandbox;
581     ++textwinlock;
582     *cp = NUL;
583     if (eval0(arg, &tv, NULL, EVAL_EVALUATE) == FAIL)
584 	retval = 0;
585     else
586     {
587 	// If the result is a number, just return the number.
588 	if (tv.v_type == VAR_NUMBER)
589 	    retval = tv.vval.v_number;
590 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
591 	    retval = 0;
592 	else
593 	{
594 	    // If the result is a string, check if there is a non-digit before
595 	    // the number.
596 	    s = tv.vval.v_string;
597 	    if (!VIM_ISDIGIT(*s) && *s != '-')
598 		*cp = *s++;
599 	    retval = atol((char *)s);
600 	}
601 	clear_tv(&tv);
602     }
603     --emsg_off;
604     if (use_sandbox)
605 	--sandbox;
606     --textwinlock;
607 
608     return (int)retval;
609 }
610 #endif
611 
612 /*
613  * Get an lval: variable, Dict item or List item that can be assigned a value
614  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
615  * "name.key", "name.key[expr]" etc.
616  * Indexing only works if "name" is an existing List or Dictionary.
617  * "name" points to the start of the name.
618  * If "rettv" is not NULL it points to the value to be assigned.
619  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
620  * wrong; must end in space or cmd separator.
621  *
622  * flags:
623  *  GLV_QUIET:       do not give error messages
624  *  GLV_READ_ONLY:   will not change the variable
625  *  GLV_NO_AUTOLOAD: do not use script autoloading
626  *
627  * Returns a pointer to just after the name, including indexes.
628  * When an evaluation error occurs "lp->ll_name" is NULL;
629  * Returns NULL for a parsing error.  Still need to free items in "lp"!
630  */
631     char_u *
632 get_lval(
633     char_u	*name,
634     typval_T	*rettv,
635     lval_T	*lp,
636     int		unlet,
637     int		skip,
638     int		flags,	    // GLV_ values
639     int		fne_flags)  // flags for find_name_end()
640 {
641     char_u	*p;
642     char_u	*expr_start, *expr_end;
643     int		cc;
644     dictitem_T	*v;
645     typval_T	var1;
646     typval_T	var2;
647     int		empty1 = FALSE;
648     listitem_T	*ni;
649     char_u	*key = NULL;
650     int		len;
651     hashtab_T	*ht;
652     int		quiet = flags & GLV_QUIET;
653 
654     // Clear everything in "lp".
655     CLEAR_POINTER(lp);
656 
657     if (skip)
658     {
659 	// When skipping just find the end of the name.
660 	lp->ll_name = name;
661 	return find_name_end(name, NULL, NULL, FNE_INCL_BR | fne_flags);
662     }
663 
664     // Find the end of the name.
665     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
666     lp->ll_name_end = p;
667     if (expr_start != NULL)
668     {
669 	// Don't expand the name when we already know there is an error.
670 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
671 						    && *p != '[' && *p != '.')
672 	{
673 	    emsg(_(e_trailing));
674 	    return NULL;
675 	}
676 
677 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
678 	if (lp->ll_exp_name == NULL)
679 	{
680 	    // Report an invalid expression in braces, unless the
681 	    // expression evaluation has been cancelled due to an
682 	    // aborting error, an interrupt, or an exception.
683 	    if (!aborting() && !quiet)
684 	    {
685 		emsg_severe = TRUE;
686 		semsg(_(e_invarg2), name);
687 		return NULL;
688 	    }
689 	}
690 	lp->ll_name = lp->ll_exp_name;
691     }
692     else
693     {
694 	lp->ll_name = name;
695 
696 	if (current_sctx.sc_version == SCRIPT_VERSION_VIM9 && *p == ':')
697 	{
698 	    scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);
699 	    char_u	 *tp = skipwhite(p + 1);
700 
701 	    // parse the type after the name
702 	    lp->ll_type = parse_type(&tp, &si->sn_type_list);
703 	    lp->ll_name_end = tp;
704 	}
705     }
706 
707     // Without [idx] or .key we are done.
708     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
709 	return p;
710 
711     cc = *p;
712     *p = NUL;
713     // Only pass &ht when we would write to the variable, it prevents autoload
714     // as well.
715     v = find_var(lp->ll_name, (flags & GLV_READ_ONLY) ? NULL : &ht,
716 						      flags & GLV_NO_AUTOLOAD);
717     if (v == NULL && !quiet)
718 	semsg(_(e_undefvar), lp->ll_name);
719     *p = cc;
720     if (v == NULL)
721 	return NULL;
722 
723     /*
724      * Loop until no more [idx] or .key is following.
725      */
726     lp->ll_tv = &v->di_tv;
727     var1.v_type = VAR_UNKNOWN;
728     var2.v_type = VAR_UNKNOWN;
729     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
730     {
731 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
732 		&& !(lp->ll_tv->v_type == VAR_DICT
733 					   && lp->ll_tv->vval.v_dict != NULL)
734 		&& !(lp->ll_tv->v_type == VAR_BLOB
735 					   && lp->ll_tv->vval.v_blob != NULL))
736 	{
737 	    if (!quiet)
738 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
739 	    return NULL;
740 	}
741 	if (lp->ll_range)
742 	{
743 	    if (!quiet)
744 		emsg(_("E708: [:] must come last"));
745 	    return NULL;
746 	}
747 
748 	len = -1;
749 	if (*p == '.')
750 	{
751 	    key = p + 1;
752 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
753 		;
754 	    if (len == 0)
755 	    {
756 		if (!quiet)
757 		    emsg(_(e_emptykey));
758 		return NULL;
759 	    }
760 	    p = key + len;
761 	}
762 	else
763 	{
764 	    // Get the index [expr] or the first index [expr: ].
765 	    p = skipwhite(p + 1);
766 	    if (*p == ':')
767 		empty1 = TRUE;
768 	    else
769 	    {
770 		empty1 = FALSE;
771 		if (eval1(&p, &var1, EVAL_EVALUATE) == FAIL)  // recursive!
772 		    return NULL;
773 		if (tv_get_string_chk(&var1) == NULL)
774 		{
775 		    // not a number or string
776 		    clear_tv(&var1);
777 		    return NULL;
778 		}
779 	    }
780 
781 	    // Optionally get the second index [ :expr].
782 	    if (*p == ':')
783 	    {
784 		if (lp->ll_tv->v_type == VAR_DICT)
785 		{
786 		    if (!quiet)
787 			emsg(_(e_dictrange));
788 		    clear_tv(&var1);
789 		    return NULL;
790 		}
791 		if (rettv != NULL
792 			&& !(rettv->v_type == VAR_LIST
793 						 && rettv->vval.v_list != NULL)
794 			&& !(rettv->v_type == VAR_BLOB
795 						&& rettv->vval.v_blob != NULL))
796 		{
797 		    if (!quiet)
798 			emsg(_("E709: [:] requires a List or Blob value"));
799 		    clear_tv(&var1);
800 		    return NULL;
801 		}
802 		p = skipwhite(p + 1);
803 		if (*p == ']')
804 		    lp->ll_empty2 = TRUE;
805 		else
806 		{
807 		    lp->ll_empty2 = FALSE;
808 		    // recursive!
809 		    if (eval1(&p, &var2, EVAL_EVALUATE) == FAIL)
810 		    {
811 			clear_tv(&var1);
812 			return NULL;
813 		    }
814 		    if (tv_get_string_chk(&var2) == NULL)
815 		    {
816 			// not a number or string
817 			clear_tv(&var1);
818 			clear_tv(&var2);
819 			return NULL;
820 		    }
821 		}
822 		lp->ll_range = TRUE;
823 	    }
824 	    else
825 		lp->ll_range = FALSE;
826 
827 	    if (*p != ']')
828 	    {
829 		if (!quiet)
830 		    emsg(_(e_missbrac));
831 		clear_tv(&var1);
832 		clear_tv(&var2);
833 		return NULL;
834 	    }
835 
836 	    // Skip to past ']'.
837 	    ++p;
838 	}
839 
840 	if (lp->ll_tv->v_type == VAR_DICT)
841 	{
842 	    if (len == -1)
843 	    {
844 		// "[key]": get key from "var1"
845 		key = tv_get_string_chk(&var1);	// is number or string
846 		if (key == NULL)
847 		{
848 		    clear_tv(&var1);
849 		    return NULL;
850 		}
851 	    }
852 	    lp->ll_list = NULL;
853 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
854 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
855 
856 	    // When assigning to a scope dictionary check that a function and
857 	    // variable name is valid (only variable name unless it is l: or
858 	    // g: dictionary). Disallow overwriting a builtin function.
859 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
860 	    {
861 		int prevval;
862 		int wrong;
863 
864 		if (len != -1)
865 		{
866 		    prevval = key[len];
867 		    key[len] = NUL;
868 		}
869 		else
870 		    prevval = 0; // avoid compiler warning
871 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
872 			       && rettv->v_type == VAR_FUNC
873 			       && var_check_func_name(key, lp->ll_di == NULL))
874 			|| !valid_varname(key);
875 		if (len != -1)
876 		    key[len] = prevval;
877 		if (wrong)
878 		{
879 		    clear_tv(&var1);
880 		    return NULL;
881 		}
882 	    }
883 
884 	    if (lp->ll_di == NULL)
885 	    {
886 		// Can't add "v:" or "a:" variable.
887 		if (lp->ll_dict == get_vimvar_dict()
888 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
889 		{
890 		    semsg(_(e_illvar), name);
891 		    clear_tv(&var1);
892 		    return NULL;
893 		}
894 
895 		// Key does not exist in dict: may need to add it.
896 		if (*p == '[' || *p == '.' || unlet)
897 		{
898 		    if (!quiet)
899 			semsg(_(e_dictkey), key);
900 		    clear_tv(&var1);
901 		    return NULL;
902 		}
903 		if (len == -1)
904 		    lp->ll_newkey = vim_strsave(key);
905 		else
906 		    lp->ll_newkey = vim_strnsave(key, len);
907 		clear_tv(&var1);
908 		if (lp->ll_newkey == NULL)
909 		    p = NULL;
910 		break;
911 	    }
912 	    // existing variable, need to check if it can be changed
913 	    else if ((flags & GLV_READ_ONLY) == 0
914 			     && var_check_ro(lp->ll_di->di_flags, name, FALSE))
915 	    {
916 		clear_tv(&var1);
917 		return NULL;
918 	    }
919 
920 	    clear_tv(&var1);
921 	    lp->ll_tv = &lp->ll_di->di_tv;
922 	}
923 	else if (lp->ll_tv->v_type == VAR_BLOB)
924 	{
925 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
926 
927 	    /*
928 	     * Get the number and item for the only or first index of the List.
929 	     */
930 	    if (empty1)
931 		lp->ll_n1 = 0;
932 	    else
933 		// is number or string
934 		lp->ll_n1 = (long)tv_get_number(&var1);
935 	    clear_tv(&var1);
936 
937 	    if (lp->ll_n1 < 0
938 		    || lp->ll_n1 > bloblen
939 		    || (lp->ll_range && lp->ll_n1 == bloblen))
940 	    {
941 		if (!quiet)
942 		    semsg(_(e_blobidx), lp->ll_n1);
943 		clear_tv(&var2);
944 		return NULL;
945 	    }
946 	    if (lp->ll_range && !lp->ll_empty2)
947 	    {
948 		lp->ll_n2 = (long)tv_get_number(&var2);
949 		clear_tv(&var2);
950 		if (lp->ll_n2 < 0
951 			|| lp->ll_n2 >= bloblen
952 			|| lp->ll_n2 < lp->ll_n1)
953 		{
954 		    if (!quiet)
955 			semsg(_(e_blobidx), lp->ll_n2);
956 		    return NULL;
957 		}
958 	    }
959 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
960 	    lp->ll_tv = NULL;
961 	    break;
962 	}
963 	else
964 	{
965 	    /*
966 	     * Get the number and item for the only or first index of the List.
967 	     */
968 	    if (empty1)
969 		lp->ll_n1 = 0;
970 	    else
971 		// is number or string
972 		lp->ll_n1 = (long)tv_get_number(&var1);
973 	    clear_tv(&var1);
974 
975 	    lp->ll_dict = NULL;
976 	    lp->ll_list = lp->ll_tv->vval.v_list;
977 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
978 	    if (lp->ll_li == NULL)
979 	    {
980 		if (lp->ll_n1 < 0)
981 		{
982 		    lp->ll_n1 = 0;
983 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
984 		}
985 	    }
986 	    if (lp->ll_li == NULL)
987 	    {
988 		clear_tv(&var2);
989 		if (!quiet)
990 		    semsg(_(e_listidx), lp->ll_n1);
991 		return NULL;
992 	    }
993 
994 	    /*
995 	     * May need to find the item or absolute index for the second
996 	     * index of a range.
997 	     * When no index given: "lp->ll_empty2" is TRUE.
998 	     * Otherwise "lp->ll_n2" is set to the second index.
999 	     */
1000 	    if (lp->ll_range && !lp->ll_empty2)
1001 	    {
1002 		lp->ll_n2 = (long)tv_get_number(&var2);
1003 						    // is number or string
1004 		clear_tv(&var2);
1005 		if (lp->ll_n2 < 0)
1006 		{
1007 		    ni = list_find(lp->ll_list, lp->ll_n2);
1008 		    if (ni == NULL)
1009 		    {
1010 			if (!quiet)
1011 			    semsg(_(e_listidx), lp->ll_n2);
1012 			return NULL;
1013 		    }
1014 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
1015 		}
1016 
1017 		// Check that lp->ll_n2 isn't before lp->ll_n1.
1018 		if (lp->ll_n1 < 0)
1019 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
1020 		if (lp->ll_n2 < lp->ll_n1)
1021 		{
1022 		    if (!quiet)
1023 			semsg(_(e_listidx), lp->ll_n2);
1024 		    return NULL;
1025 		}
1026 	    }
1027 
1028 	    lp->ll_tv = &lp->ll_li->li_tv;
1029 	}
1030     }
1031 
1032     clear_tv(&var1);
1033     lp->ll_name_end = p;
1034     return p;
1035 }
1036 
1037 /*
1038  * Clear lval "lp" that was filled by get_lval().
1039  */
1040     void
1041 clear_lval(lval_T *lp)
1042 {
1043     vim_free(lp->ll_exp_name);
1044     vim_free(lp->ll_newkey);
1045 }
1046 
1047 /*
1048  * Set a variable that was parsed by get_lval() to "rettv".
1049  * "endp" points to just after the parsed name.
1050  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
1051  * "%" for "%=", "." for ".=" or "=" for "=".
1052  */
1053     void
1054 set_var_lval(
1055     lval_T	*lp,
1056     char_u	*endp,
1057     typval_T	*rettv,
1058     int		copy,
1059     int		flags,    // LET_IS_CONST and/or LET_NO_COMMAND
1060     char_u	*op)
1061 {
1062     int		cc;
1063     listitem_T	*ri;
1064     dictitem_T	*di;
1065 
1066     if (lp->ll_tv == NULL)
1067     {
1068 	cc = *endp;
1069 	*endp = NUL;
1070 	if (lp->ll_blob != NULL)
1071 	{
1072 	    int	    error = FALSE, val;
1073 
1074 	    if (op != NULL && *op != '=')
1075 	    {
1076 		semsg(_(e_letwrong), op);
1077 		return;
1078 	    }
1079 
1080 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
1081 	    {
1082 		int	il, ir;
1083 
1084 		if (lp->ll_empty2)
1085 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
1086 
1087 		if (lp->ll_n2 - lp->ll_n1 + 1 != blob_len(rettv->vval.v_blob))
1088 		{
1089 		    emsg(_("E972: Blob value does not have the right number of bytes"));
1090 		    return;
1091 		}
1092 		if (lp->ll_empty2)
1093 		    lp->ll_n2 = blob_len(lp->ll_blob);
1094 
1095 		ir = 0;
1096 		for (il = lp->ll_n1; il <= lp->ll_n2; il++)
1097 		    blob_set(lp->ll_blob, il,
1098 			    blob_get(rettv->vval.v_blob, ir++));
1099 	    }
1100 	    else
1101 	    {
1102 		val = (int)tv_get_number_chk(rettv, &error);
1103 		if (!error)
1104 		{
1105 		    garray_T *gap = &lp->ll_blob->bv_ga;
1106 
1107 		    // Allow for appending a byte.  Setting a byte beyond
1108 		    // the end is an error otherwise.
1109 		    if (lp->ll_n1 < gap->ga_len
1110 			    || (lp->ll_n1 == gap->ga_len
1111 				&& ga_grow(&lp->ll_blob->bv_ga, 1) == OK))
1112 		    {
1113 			blob_set(lp->ll_blob, lp->ll_n1, val);
1114 			if (lp->ll_n1 == gap->ga_len)
1115 			    ++gap->ga_len;
1116 		    }
1117 		    // error for invalid range was already given in get_lval()
1118 		}
1119 	    }
1120 	}
1121 	else if (op != NULL && *op != '=')
1122 	{
1123 	    typval_T tv;
1124 
1125 	    if (flags & LET_IS_CONST)
1126 	    {
1127 		emsg(_(e_cannot_mod));
1128 		*endp = cc;
1129 		return;
1130 	    }
1131 
1132 	    // handle +=, -=, *=, /=, %= and .=
1133 	    di = NULL;
1134 	    if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
1135 					     &tv, &di, TRUE, FALSE) == OK)
1136 	    {
1137 		if ((di == NULL
1138 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
1139 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
1140 			&& tv_op(&tv, rettv, op) == OK)
1141 		    set_var(lp->ll_name, &tv, FALSE);
1142 		clear_tv(&tv);
1143 	    }
1144 	}
1145 	else
1146 	    set_var_const(lp->ll_name, lp->ll_type, rettv, copy, flags);
1147 	*endp = cc;
1148     }
1149     else if (var_check_lock(lp->ll_newkey == NULL
1150 		? lp->ll_tv->v_lock
1151 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
1152 	;
1153     else if (lp->ll_range)
1154     {
1155 	listitem_T *ll_li = lp->ll_li;
1156 	int	    ll_n1 = lp->ll_n1;
1157 
1158 	if (flags & LET_IS_CONST)
1159 	{
1160 	    emsg(_("E996: Cannot lock a range"));
1161 	    return;
1162 	}
1163 
1164 	/*
1165 	 * Check whether any of the list items is locked
1166 	 */
1167 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
1168 	{
1169 	    if (var_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
1170 		return;
1171 	    ri = ri->li_next;
1172 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
1173 		break;
1174 	    ll_li = ll_li->li_next;
1175 	    ++ll_n1;
1176 	}
1177 
1178 	/*
1179 	 * Assign the List values to the list items.
1180 	 */
1181 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
1182 	{
1183 	    if (op != NULL && *op != '=')
1184 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
1185 	    else
1186 	    {
1187 		clear_tv(&lp->ll_li->li_tv);
1188 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
1189 	    }
1190 	    ri = ri->li_next;
1191 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
1192 		break;
1193 	    if (lp->ll_li->li_next == NULL)
1194 	    {
1195 		// Need to add an empty item.
1196 		if (list_append_number(lp->ll_list, 0) == FAIL)
1197 		{
1198 		    ri = NULL;
1199 		    break;
1200 		}
1201 	    }
1202 	    lp->ll_li = lp->ll_li->li_next;
1203 	    ++lp->ll_n1;
1204 	}
1205 	if (ri != NULL)
1206 	    emsg(_("E710: List value has more items than target"));
1207 	else if (lp->ll_empty2
1208 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
1209 		: lp->ll_n1 != lp->ll_n2)
1210 	    emsg(_("E711: List value has not enough items"));
1211     }
1212     else
1213     {
1214 	/*
1215 	 * Assign to a List or Dictionary item.
1216 	 */
1217 	if (flags & LET_IS_CONST)
1218 	{
1219 	    emsg(_("E996: Cannot lock a list or dict"));
1220 	    return;
1221 	}
1222 	if (lp->ll_newkey != NULL)
1223 	{
1224 	    if (op != NULL && *op != '=')
1225 	    {
1226 		semsg(_(e_letwrong), op);
1227 		return;
1228 	    }
1229 
1230 	    // Need to add an item to the Dictionary.
1231 	    di = dictitem_alloc(lp->ll_newkey);
1232 	    if (di == NULL)
1233 		return;
1234 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
1235 	    {
1236 		vim_free(di);
1237 		return;
1238 	    }
1239 	    lp->ll_tv = &di->di_tv;
1240 	}
1241 	else if (op != NULL && *op != '=')
1242 	{
1243 	    tv_op(lp->ll_tv, rettv, op);
1244 	    return;
1245 	}
1246 	else
1247 	    clear_tv(lp->ll_tv);
1248 
1249 	/*
1250 	 * Assign the value to the variable or list item.
1251 	 */
1252 	if (copy)
1253 	    copy_tv(rettv, lp->ll_tv);
1254 	else
1255 	{
1256 	    *lp->ll_tv = *rettv;
1257 	    lp->ll_tv->v_lock = 0;
1258 	    init_tv(rettv);
1259 	}
1260     }
1261 }
1262 
1263 /*
1264  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
1265  * and "tv1 .= tv2"
1266  * Returns OK or FAIL.
1267  */
1268     static int
1269 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
1270 {
1271     varnumber_T	n;
1272     char_u	numbuf[NUMBUFLEN];
1273     char_u	*s;
1274 
1275     // Can't do anything with a Funcref, Dict, v:true on the right.
1276     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
1277 		      && tv2->v_type != VAR_BOOL && tv2->v_type != VAR_SPECIAL)
1278     {
1279 	switch (tv1->v_type)
1280 	{
1281 	    case VAR_UNKNOWN:
1282 	    case VAR_ANY:
1283 	    case VAR_VOID:
1284 	    case VAR_DICT:
1285 	    case VAR_FUNC:
1286 	    case VAR_PARTIAL:
1287 	    case VAR_BOOL:
1288 	    case VAR_SPECIAL:
1289 	    case VAR_JOB:
1290 	    case VAR_CHANNEL:
1291 		break;
1292 
1293 	    case VAR_BLOB:
1294 		if (*op != '+' || tv2->v_type != VAR_BLOB)
1295 		    break;
1296 		// BLOB += BLOB
1297 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
1298 		{
1299 		    blob_T  *b1 = tv1->vval.v_blob;
1300 		    blob_T  *b2 = tv2->vval.v_blob;
1301 		    int	i, len = blob_len(b2);
1302 		    for (i = 0; i < len; i++)
1303 			ga_append(&b1->bv_ga, blob_get(b2, i));
1304 		}
1305 		return OK;
1306 
1307 	    case VAR_LIST:
1308 		if (*op != '+' || tv2->v_type != VAR_LIST)
1309 		    break;
1310 		// List += List
1311 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
1312 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
1313 		return OK;
1314 
1315 	    case VAR_NUMBER:
1316 	    case VAR_STRING:
1317 		if (tv2->v_type == VAR_LIST)
1318 		    break;
1319 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
1320 		{
1321 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
1322 		    n = tv_get_number(tv1);
1323 #ifdef FEAT_FLOAT
1324 		    if (tv2->v_type == VAR_FLOAT)
1325 		    {
1326 			float_T f = n;
1327 
1328 			if (*op == '%')
1329 			    break;
1330 			switch (*op)
1331 			{
1332 			    case '+': f += tv2->vval.v_float; break;
1333 			    case '-': f -= tv2->vval.v_float; break;
1334 			    case '*': f *= tv2->vval.v_float; break;
1335 			    case '/': f /= tv2->vval.v_float; break;
1336 			}
1337 			clear_tv(tv1);
1338 			tv1->v_type = VAR_FLOAT;
1339 			tv1->vval.v_float = f;
1340 		    }
1341 		    else
1342 #endif
1343 		    {
1344 			switch (*op)
1345 			{
1346 			    case '+': n += tv_get_number(tv2); break;
1347 			    case '-': n -= tv_get_number(tv2); break;
1348 			    case '*': n *= tv_get_number(tv2); break;
1349 			    case '/': n = num_divide(n, tv_get_number(tv2)); break;
1350 			    case '%': n = num_modulus(n, tv_get_number(tv2)); break;
1351 			}
1352 			clear_tv(tv1);
1353 			tv1->v_type = VAR_NUMBER;
1354 			tv1->vval.v_number = n;
1355 		    }
1356 		}
1357 		else
1358 		{
1359 		    if (tv2->v_type == VAR_FLOAT)
1360 			break;
1361 
1362 		    // str .= str
1363 		    s = tv_get_string(tv1);
1364 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
1365 		    clear_tv(tv1);
1366 		    tv1->v_type = VAR_STRING;
1367 		    tv1->vval.v_string = s;
1368 		}
1369 		return OK;
1370 
1371 	    case VAR_FLOAT:
1372 #ifdef FEAT_FLOAT
1373 		{
1374 		    float_T f;
1375 
1376 		    if (*op == '%' || *op == '.'
1377 				   || (tv2->v_type != VAR_FLOAT
1378 				    && tv2->v_type != VAR_NUMBER
1379 				    && tv2->v_type != VAR_STRING))
1380 			break;
1381 		    if (tv2->v_type == VAR_FLOAT)
1382 			f = tv2->vval.v_float;
1383 		    else
1384 			f = tv_get_number(tv2);
1385 		    switch (*op)
1386 		    {
1387 			case '+': tv1->vval.v_float += f; break;
1388 			case '-': tv1->vval.v_float -= f; break;
1389 			case '*': tv1->vval.v_float *= f; break;
1390 			case '/': tv1->vval.v_float /= f; break;
1391 		    }
1392 		}
1393 #endif
1394 		return OK;
1395 	}
1396     }
1397 
1398     semsg(_(e_letwrong), op);
1399     return FAIL;
1400 }
1401 
1402 /*
1403  * Evaluate the expression used in a ":for var in expr" command.
1404  * "arg" points to "var".
1405  * Set "*errp" to TRUE for an error, FALSE otherwise;
1406  * Return a pointer that holds the info.  Null when there is an error.
1407  */
1408     void *
1409 eval_for_line(
1410     char_u	*arg,
1411     int		*errp,
1412     char_u	**nextcmdp,
1413     int		skip)
1414 {
1415     forinfo_T	*fi;
1416     char_u	*expr;
1417     typval_T	tv;
1418     list_T	*l;
1419 
1420     *errp = TRUE;	// default: there is an error
1421 
1422     fi = ALLOC_CLEAR_ONE(forinfo_T);
1423     if (fi == NULL)
1424 	return NULL;
1425 
1426     expr = skip_var_list(arg, TRUE, &fi->fi_varcount, &fi->fi_semicolon);
1427     if (expr == NULL)
1428 	return fi;
1429 
1430     expr = skipwhite(expr);
1431     if (expr[0] != 'i' || expr[1] != 'n' || !VIM_ISWHITE(expr[2]))
1432     {
1433 	emsg(_(e_missing_in));
1434 	return fi;
1435     }
1436 
1437     if (skip)
1438 	++emsg_skip;
1439     if (eval0(skipwhite(expr + 2), &tv, nextcmdp, skip ? 0 : EVAL_EVALUATE)
1440 									 == OK)
1441     {
1442 	*errp = FALSE;
1443 	if (!skip)
1444 	{
1445 	    if (tv.v_type == VAR_LIST)
1446 	    {
1447 		l = tv.vval.v_list;
1448 		if (l == NULL)
1449 		{
1450 		    // a null list is like an empty list: do nothing
1451 		    clear_tv(&tv);
1452 		}
1453 		else
1454 		{
1455 		    // Need a real list here.
1456 		    CHECK_LIST_MATERIALIZE(l);
1457 
1458 		    // No need to increment the refcount, it's already set for
1459 		    // the list being used in "tv".
1460 		    fi->fi_list = l;
1461 		    list_add_watch(l, &fi->fi_lw);
1462 		    fi->fi_lw.lw_item = l->lv_first;
1463 		}
1464 	    }
1465 	    else if (tv.v_type == VAR_BLOB)
1466 	    {
1467 		fi->fi_bi = 0;
1468 		if (tv.vval.v_blob != NULL)
1469 		{
1470 		    typval_T btv;
1471 
1472 		    // Make a copy, so that the iteration still works when the
1473 		    // blob is changed.
1474 		    blob_copy(tv.vval.v_blob, &btv);
1475 		    fi->fi_blob = btv.vval.v_blob;
1476 		}
1477 		clear_tv(&tv);
1478 	    }
1479 	    else
1480 	    {
1481 		emsg(_(e_listreq));
1482 		clear_tv(&tv);
1483 	    }
1484 	}
1485     }
1486     if (skip)
1487 	--emsg_skip;
1488 
1489     return fi;
1490 }
1491 
1492 /*
1493  * Use the first item in a ":for" list.  Advance to the next.
1494  * Assign the values to the variable (list).  "arg" points to the first one.
1495  * Return TRUE when a valid item was found, FALSE when at end of list or
1496  * something wrong.
1497  */
1498     int
1499 next_for_item(void *fi_void, char_u *arg)
1500 {
1501     forinfo_T	*fi = (forinfo_T *)fi_void;
1502     int		result;
1503     int		flag = current_sctx.sc_version == SCRIPT_VERSION_VIM9 ?
1504 							LET_NO_COMMAND : 0;
1505     listitem_T	*item;
1506 
1507     if (fi->fi_blob != NULL)
1508     {
1509 	typval_T	tv;
1510 
1511 	if (fi->fi_bi >= blob_len(fi->fi_blob))
1512 	    return FALSE;
1513 	tv.v_type = VAR_NUMBER;
1514 	tv.v_lock = VAR_FIXED;
1515 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
1516 	++fi->fi_bi;
1517 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1518 				       fi->fi_varcount, flag, NULL) == OK;
1519     }
1520 
1521     item = fi->fi_lw.lw_item;
1522     if (item == NULL)
1523 	result = FALSE;
1524     else
1525     {
1526 	fi->fi_lw.lw_item = item->li_next;
1527 	result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
1528 				      fi->fi_varcount, flag, NULL) == OK);
1529     }
1530     return result;
1531 }
1532 
1533 /*
1534  * Free the structure used to store info used by ":for".
1535  */
1536     void
1537 free_for_info(void *fi_void)
1538 {
1539     forinfo_T    *fi = (forinfo_T *)fi_void;
1540 
1541     if (fi != NULL && fi->fi_list != NULL)
1542     {
1543 	list_rem_watch(fi->fi_list, &fi->fi_lw);
1544 	list_unref(fi->fi_list);
1545     }
1546     if (fi != NULL && fi->fi_blob != NULL)
1547 	blob_unref(fi->fi_blob);
1548     vim_free(fi);
1549 }
1550 
1551     void
1552 set_context_for_expression(
1553     expand_T	*xp,
1554     char_u	*arg,
1555     cmdidx_T	cmdidx)
1556 {
1557     int		got_eq = FALSE;
1558     int		c;
1559     char_u	*p;
1560 
1561     if (cmdidx == CMD_let || cmdidx == CMD_const)
1562     {
1563 	xp->xp_context = EXPAND_USER_VARS;
1564 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
1565 	{
1566 	    // ":let var1 var2 ...": find last space.
1567 	    for (p = arg + STRLEN(arg); p >= arg; )
1568 	    {
1569 		xp->xp_pattern = p;
1570 		MB_PTR_BACK(arg, p);
1571 		if (VIM_ISWHITE(*p))
1572 		    break;
1573 	    }
1574 	    return;
1575 	}
1576     }
1577     else
1578 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
1579 							  : EXPAND_EXPRESSION;
1580     while ((xp->xp_pattern = vim_strpbrk(arg,
1581 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
1582     {
1583 	c = *xp->xp_pattern;
1584 	if (c == '&')
1585 	{
1586 	    c = xp->xp_pattern[1];
1587 	    if (c == '&')
1588 	    {
1589 		++xp->xp_pattern;
1590 		xp->xp_context = cmdidx != CMD_let || got_eq
1591 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
1592 	    }
1593 	    else if (c != ' ')
1594 	    {
1595 		xp->xp_context = EXPAND_SETTINGS;
1596 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
1597 		    xp->xp_pattern += 2;
1598 
1599 	    }
1600 	}
1601 	else if (c == '$')
1602 	{
1603 	    // environment variable
1604 	    xp->xp_context = EXPAND_ENV_VARS;
1605 	}
1606 	else if (c == '=')
1607 	{
1608 	    got_eq = TRUE;
1609 	    xp->xp_context = EXPAND_EXPRESSION;
1610 	}
1611 	else if (c == '#'
1612 		&& xp->xp_context == EXPAND_EXPRESSION)
1613 	{
1614 	    // Autoload function/variable contains '#'.
1615 	    break;
1616 	}
1617 	else if ((c == '<' || c == '#')
1618 		&& xp->xp_context == EXPAND_FUNCTIONS
1619 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
1620 	{
1621 	    // Function name can start with "<SNR>" and contain '#'.
1622 	    break;
1623 	}
1624 	else if (cmdidx != CMD_let || got_eq)
1625 	{
1626 	    if (c == '"')	    // string
1627 	    {
1628 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
1629 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
1630 			++xp->xp_pattern;
1631 		xp->xp_context = EXPAND_NOTHING;
1632 	    }
1633 	    else if (c == '\'')	    // literal string
1634 	    {
1635 		// Trick: '' is like stopping and starting a literal string.
1636 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
1637 		    /* skip */ ;
1638 		xp->xp_context = EXPAND_NOTHING;
1639 	    }
1640 	    else if (c == '|')
1641 	    {
1642 		if (xp->xp_pattern[1] == '|')
1643 		{
1644 		    ++xp->xp_pattern;
1645 		    xp->xp_context = EXPAND_EXPRESSION;
1646 		}
1647 		else
1648 		    xp->xp_context = EXPAND_COMMANDS;
1649 	    }
1650 	    else
1651 		xp->xp_context = EXPAND_EXPRESSION;
1652 	}
1653 	else
1654 	    // Doesn't look like something valid, expand as an expression
1655 	    // anyway.
1656 	    xp->xp_context = EXPAND_EXPRESSION;
1657 	arg = xp->xp_pattern;
1658 	if (*arg != NUL)
1659 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
1660 		/* skip */ ;
1661     }
1662     xp->xp_pattern = arg;
1663 }
1664 
1665 /*
1666  * Return TRUE if "pat" matches "text".
1667  * Does not use 'cpo' and always uses 'magic'.
1668  */
1669     int
1670 pattern_match(char_u *pat, char_u *text, int ic)
1671 {
1672     int		matches = FALSE;
1673     char_u	*save_cpo;
1674     regmatch_T	regmatch;
1675 
1676     // avoid 'l' flag in 'cpoptions'
1677     save_cpo = p_cpo;
1678     p_cpo = (char_u *)"";
1679     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1680     if (regmatch.regprog != NULL)
1681     {
1682 	regmatch.rm_ic = ic;
1683 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
1684 	vim_regfree(regmatch.regprog);
1685     }
1686     p_cpo = save_cpo;
1687     return matches;
1688 }
1689 
1690 /*
1691  * Handle a name followed by "(".  Both for just "name(arg)" and for
1692  * "expr->name(arg)".
1693  * Returns OK or FAIL.
1694  */
1695     static int
1696 eval_func(
1697 	char_u	    **arg,	// points to "(", will be advanced
1698 	char_u	    *name,
1699 	int	    name_len,
1700 	typval_T    *rettv,
1701 	int	    flags,
1702 	typval_T    *basetv)	// "expr" for "expr->name(arg)"
1703 {
1704     int		evaluate = flags & EVAL_EVALUATE;
1705     char_u	*s = name;
1706     int		len = name_len;
1707     partial_T	*partial;
1708     int		ret = OK;
1709 
1710     if (!evaluate)
1711 	check_vars(s, len);
1712 
1713     // If "s" is the name of a variable of type VAR_FUNC
1714     // use its contents.
1715     s = deref_func_name(s, &len, &partial, !evaluate);
1716 
1717     // Need to make a copy, in case evaluating the arguments makes
1718     // the name invalid.
1719     s = vim_strsave(s);
1720     if (s == NULL || (flags & EVAL_CONSTANT))
1721 	ret = FAIL;
1722     else
1723     {
1724 	funcexe_T funcexe;
1725 
1726 	// Invoke the function.
1727 	CLEAR_FIELD(funcexe);
1728 	funcexe.firstline = curwin->w_cursor.lnum;
1729 	funcexe.lastline = curwin->w_cursor.lnum;
1730 	funcexe.evaluate = evaluate;
1731 	funcexe.partial = partial;
1732 	funcexe.basetv = basetv;
1733 	ret = get_func_tv(s, len, rettv, arg, &funcexe);
1734     }
1735     vim_free(s);
1736 
1737     // If evaluate is FALSE rettv->v_type was not set in
1738     // get_func_tv, but it's needed in handle_subscript() to parse
1739     // what follows. So set it here.
1740     if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
1741     {
1742 	rettv->vval.v_string = NULL;
1743 	rettv->v_type = VAR_FUNC;
1744     }
1745 
1746     // Stop the expression evaluation when immediately
1747     // aborting on error, or when an interrupt occurred or
1748     // an exception was thrown but not caught.
1749     if (evaluate && aborting())
1750     {
1751 	if (ret == OK)
1752 	    clear_tv(rettv);
1753 	ret = FAIL;
1754     }
1755     return ret;
1756 }
1757 
1758 /*
1759  * The "evaluate" argument: When FALSE, the argument is only parsed but not
1760  * executed.  The function may return OK, but the rettv will be of type
1761  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
1762  */
1763 
1764 /*
1765  * Handle zero level expression.
1766  * This calls eval1() and handles error message and nextcmd.
1767  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
1768  * Note: "rettv.v_lock" is not set.
1769  * "flags" has EVAL_EVALUATE and similar flags.
1770  * Return OK or FAIL.
1771  */
1772     int
1773 eval0(
1774     char_u	*arg,
1775     typval_T	*rettv,
1776     char_u	**nextcmd,
1777     int		flags)
1778 {
1779     int		ret;
1780     char_u	*p;
1781     int		did_emsg_before = did_emsg;
1782     int		called_emsg_before = called_emsg;
1783 
1784     p = skipwhite(arg);
1785     ret = eval1(&p, rettv, flags);
1786     if (ret == FAIL || !ends_excmd2(arg, p))
1787     {
1788 	if (ret != FAIL)
1789 	    clear_tv(rettv);
1790 	/*
1791 	 * Report the invalid expression unless the expression evaluation has
1792 	 * been cancelled due to an aborting error, an interrupt, or an
1793 	 * exception, or we already gave a more specific error.
1794 	 * Also check called_emsg for when using assert_fails().
1795 	 */
1796 	if (!aborting()
1797 		&& did_emsg == did_emsg_before
1798 		&& called_emsg == called_emsg_before
1799 		&& (flags & EVAL_CONSTANT) == 0)
1800 	    semsg(_(e_invexpr2), arg);
1801 	ret = FAIL;
1802     }
1803     if (nextcmd != NULL)
1804 	*nextcmd = check_nextcmd(p);
1805 
1806     return ret;
1807 }
1808 
1809 /*
1810  * Handle top level expression:
1811  *	expr2 ? expr1 : expr1
1812  *
1813  * "arg" must point to the first non-white of the expression.
1814  * "arg" is advanced to the next non-white after the recognized expression.
1815  *
1816  * Note: "rettv.v_lock" is not set.
1817  *
1818  * Return OK or FAIL.
1819  */
1820     int
1821 eval1(char_u **arg, typval_T *rettv, int flags)
1822 {
1823     int		result;
1824     typval_T	var2;
1825 
1826     /*
1827      * Get the first variable.
1828      */
1829     if (eval2(arg, rettv, flags) == FAIL)
1830 	return FAIL;
1831 
1832     if ((*arg)[0] == '?')
1833     {
1834 	int evaluate = flags & EVAL_EVALUATE;
1835 
1836 	result = FALSE;
1837 	if (flags & EVAL_EVALUATE)
1838 	{
1839 	    int		error = FALSE;
1840 
1841 	    if (tv_get_number_chk(rettv, &error) != 0)
1842 		result = TRUE;
1843 	    clear_tv(rettv);
1844 	    if (error)
1845 		return FAIL;
1846 	}
1847 
1848 	/*
1849 	 * Get the second variable.  Recursive!
1850 	 */
1851 	*arg = skipwhite(*arg + 1);
1852 	if (eval1(arg, rettv, result ? flags : flags & ~EVAL_EVALUATE) == FAIL)
1853 	    return FAIL;
1854 
1855 	/*
1856 	 * Check for the ":".
1857 	 */
1858 	if ((*arg)[0] != ':')
1859 	{
1860 	    emsg(_(e_missing_colon));
1861 	    if (evaluate && result)
1862 		clear_tv(rettv);
1863 	    return FAIL;
1864 	}
1865 
1866 	/*
1867 	 * Get the third variable.  Recursive!
1868 	 */
1869 	*arg = skipwhite(*arg + 1);
1870 	if (eval1(arg, &var2, !result ? flags : flags & ~EVAL_EVALUATE) == FAIL)
1871 	{
1872 	    if (evaluate && result)
1873 		clear_tv(rettv);
1874 	    return FAIL;
1875 	}
1876 	if (evaluate && !result)
1877 	    *rettv = var2;
1878     }
1879 
1880     return OK;
1881 }
1882 
1883 /*
1884  * Handle first level expression:
1885  *	expr2 || expr2 || expr2	    logical OR
1886  *
1887  * "arg" must point to the first non-white of the expression.
1888  * "arg" is advanced to the next non-white after the recognized expression.
1889  *
1890  * Return OK or FAIL.
1891  */
1892     static int
1893 eval2(char_u **arg, typval_T *rettv, int flags)
1894 {
1895     typval_T	var2;
1896     long	result;
1897     int		first;
1898     int		error = FALSE;
1899 
1900     /*
1901      * Get the first variable.
1902      */
1903     if (eval3(arg, rettv, flags) == FAIL)
1904 	return FAIL;
1905 
1906     /*
1907      * Repeat until there is no following "||".
1908      */
1909     first = TRUE;
1910     result = FALSE;
1911     while ((*arg)[0] == '|' && (*arg)[1] == '|')
1912     {
1913 	int evaluate = flags & EVAL_EVALUATE;
1914 
1915 	if (evaluate && first)
1916 	{
1917 	    if (tv_get_number_chk(rettv, &error) != 0)
1918 		result = TRUE;
1919 	    clear_tv(rettv);
1920 	    if (error)
1921 		return FAIL;
1922 	    first = FALSE;
1923 	}
1924 
1925 	/*
1926 	 * Get the second variable.
1927 	 */
1928 	*arg = skipwhite(*arg + 2);
1929 	if (eval3(arg, &var2, !result ? flags : flags & ~EVAL_EVALUATE)
1930 								       == FAIL)
1931 	    return FAIL;
1932 
1933 	/*
1934 	 * Compute the result.
1935 	 */
1936 	if (evaluate && !result)
1937 	{
1938 	    if (tv_get_number_chk(&var2, &error) != 0)
1939 		result = TRUE;
1940 	    clear_tv(&var2);
1941 	    if (error)
1942 		return FAIL;
1943 	}
1944 	if (evaluate)
1945 	{
1946 	    rettv->v_type = VAR_NUMBER;
1947 	    rettv->vval.v_number = result;
1948 	}
1949     }
1950 
1951     return OK;
1952 }
1953 
1954 /*
1955  * Handle second level expression:
1956  *	expr3 && expr3 && expr3	    logical AND
1957  *
1958  * "arg" must point to the first non-white of the expression.
1959  * "arg" is advanced to the next non-white after the recognized expression.
1960  *
1961  * Return OK or FAIL.
1962  */
1963     static int
1964 eval3(char_u **arg, typval_T *rettv, int flags)
1965 {
1966     typval_T	var2;
1967     long	result;
1968     int		first;
1969     int		error = FALSE;
1970 
1971     /*
1972      * Get the first variable.
1973      */
1974     if (eval4(arg, rettv, flags) == FAIL)
1975 	return FAIL;
1976 
1977     /*
1978      * Repeat until there is no following "&&".
1979      */
1980     first = TRUE;
1981     result = TRUE;
1982     while ((*arg)[0] == '&' && (*arg)[1] == '&')
1983     {
1984 	int evaluate = flags & EVAL_EVALUATE;
1985 
1986 	if (evaluate && first)
1987 	{
1988 	    if (tv_get_number_chk(rettv, &error) == 0)
1989 		result = FALSE;
1990 	    clear_tv(rettv);
1991 	    if (error)
1992 		return FAIL;
1993 	    first = FALSE;
1994 	}
1995 
1996 	/*
1997 	 * Get the second variable.
1998 	 */
1999 	*arg = skipwhite(*arg + 2);
2000 	if (eval4(arg, &var2, result ? flags : flags & ~EVAL_EVALUATE) == FAIL)
2001 	    return FAIL;
2002 
2003 	/*
2004 	 * Compute the result.
2005 	 */
2006 	if (evaluate && result)
2007 	{
2008 	    if (tv_get_number_chk(&var2, &error) == 0)
2009 		result = FALSE;
2010 	    clear_tv(&var2);
2011 	    if (error)
2012 		return FAIL;
2013 	}
2014 	if (evaluate)
2015 	{
2016 	    rettv->v_type = VAR_NUMBER;
2017 	    rettv->vval.v_number = result;
2018 	}
2019     }
2020 
2021     return OK;
2022 }
2023 
2024 /*
2025  * Handle third level expression:
2026  *	var1 == var2
2027  *	var1 =~ var2
2028  *	var1 != var2
2029  *	var1 !~ var2
2030  *	var1 > var2
2031  *	var1 >= var2
2032  *	var1 < var2
2033  *	var1 <= var2
2034  *	var1 is var2
2035  *	var1 isnot var2
2036  *
2037  * "arg" must point to the first non-white of the expression.
2038  * "arg" is advanced to the next non-white after the recognized expression.
2039  *
2040  * Return OK or FAIL.
2041  */
2042     static int
2043 eval4(char_u **arg, typval_T *rettv, int flags)
2044 {
2045     typval_T	var2;
2046     char_u	*p;
2047     int		i;
2048     exptype_T	type = EXPR_UNKNOWN;
2049     int		len = 2;
2050     int		ic;
2051 
2052     /*
2053      * Get the first variable.
2054      */
2055     if (eval5(arg, rettv, flags) == FAIL)
2056 	return FAIL;
2057 
2058     p = *arg;
2059     switch (p[0])
2060     {
2061 	case '=':   if (p[1] == '=')
2062 			type = EXPR_EQUAL;
2063 		    else if (p[1] == '~')
2064 			type = EXPR_MATCH;
2065 		    break;
2066 	case '!':   if (p[1] == '=')
2067 			type = EXPR_NEQUAL;
2068 		    else if (p[1] == '~')
2069 			type = EXPR_NOMATCH;
2070 		    break;
2071 	case '>':   if (p[1] != '=')
2072 		    {
2073 			type = EXPR_GREATER;
2074 			len = 1;
2075 		    }
2076 		    else
2077 			type = EXPR_GEQUAL;
2078 		    break;
2079 	case '<':   if (p[1] != '=')
2080 		    {
2081 			type = EXPR_SMALLER;
2082 			len = 1;
2083 		    }
2084 		    else
2085 			type = EXPR_SEQUAL;
2086 		    break;
2087 	case 'i':   if (p[1] == 's')
2088 		    {
2089 			if (p[2] == 'n' && p[3] == 'o' && p[4] == 't')
2090 			    len = 5;
2091 			i = p[len];
2092 			if (!isalnum(i) && i != '_')
2093 			    type = len == 2 ? EXPR_IS : EXPR_ISNOT;
2094 		    }
2095 		    break;
2096     }
2097 
2098     /*
2099      * If there is a comparative operator, use it.
2100      */
2101     if (type != EXPR_UNKNOWN)
2102     {
2103 	// extra question mark appended: ignore case
2104 	if (p[len] == '?')
2105 	{
2106 	    ic = TRUE;
2107 	    ++len;
2108 	}
2109 	// extra '#' appended: match case
2110 	else if (p[len] == '#')
2111 	{
2112 	    ic = FALSE;
2113 	    ++len;
2114 	}
2115 	// nothing appended: use 'ignorecase'
2116 	else
2117 	    ic = p_ic;
2118 
2119 	/*
2120 	 * Get the second variable.
2121 	 */
2122 	*arg = skipwhite(p + len);
2123 	if (eval5(arg, &var2, flags) == FAIL)
2124 	{
2125 	    clear_tv(rettv);
2126 	    return FAIL;
2127 	}
2128 	if (flags & EVAL_EVALUATE)
2129 	{
2130 	    int ret = typval_compare(rettv, &var2, type, ic);
2131 
2132 	    clear_tv(&var2);
2133 	    return ret;
2134 	}
2135     }
2136 
2137     return OK;
2138 }
2139 
2140     void
2141 eval_addblob(typval_T *tv1, typval_T *tv2)
2142 {
2143     blob_T  *b1 = tv1->vval.v_blob;
2144     blob_T  *b2 = tv2->vval.v_blob;
2145     blob_T  *b = blob_alloc();
2146     int	    i;
2147 
2148     if (b != NULL)
2149     {
2150 	for (i = 0; i < blob_len(b1); i++)
2151 	    ga_append(&b->bv_ga, blob_get(b1, i));
2152 	for (i = 0; i < blob_len(b2); i++)
2153 	    ga_append(&b->bv_ga, blob_get(b2, i));
2154 
2155 	clear_tv(tv1);
2156 	rettv_blob_set(tv1, b);
2157     }
2158 }
2159 
2160     int
2161 eval_addlist(typval_T *tv1, typval_T *tv2)
2162 {
2163     typval_T var3;
2164 
2165     // concatenate Lists
2166     if (list_concat(tv1->vval.v_list, tv2->vval.v_list, &var3) == FAIL)
2167     {
2168 	clear_tv(tv1);
2169 	clear_tv(tv2);
2170 	return FAIL;
2171     }
2172     clear_tv(tv1);
2173     *tv1 = var3;
2174     return OK;
2175 }
2176 
2177 /*
2178  * Handle fourth level expression:
2179  *	+	number addition
2180  *	-	number subtraction
2181  *	.	string concatenation (if script version is 1)
2182  *	..	string concatenation
2183  *
2184  * "arg" must point to the first non-white of the expression.
2185  * "arg" is advanced to the next non-white after the recognized expression.
2186  *
2187  * Return OK or FAIL.
2188  */
2189     static int
2190 eval5(char_u **arg, typval_T *rettv, int flags)
2191 {
2192     typval_T	var2;
2193     int		op;
2194     varnumber_T	n1, n2;
2195 #ifdef FEAT_FLOAT
2196     float_T	f1 = 0, f2 = 0;
2197 #endif
2198     char_u	*s1, *s2;
2199     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
2200     char_u	*p;
2201     int		concat;
2202 
2203     /*
2204      * Get the first variable.
2205      */
2206     if (eval6(arg, rettv, flags, FALSE) == FAIL)
2207 	return FAIL;
2208 
2209     /*
2210      * Repeat computing, until no '+', '-' or '.' is following.
2211      */
2212     for (;;)
2213     {
2214 	// "." is only string concatenation when scriptversion is 1
2215 	op = **arg;
2216 	concat = op == '.'
2217 			&& (*(*arg + 1) == '.' || current_sctx.sc_version < 2);
2218 	if (op != '+' && op != '-' && !concat)
2219 	    break;
2220 
2221 	if ((op != '+' || (rettv->v_type != VAR_LIST
2222 						 && rettv->v_type != VAR_BLOB))
2223 #ifdef FEAT_FLOAT
2224 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2225 #endif
2226 		)
2227 	{
2228 	    // For "list + ...", an illegal use of the first operand as
2229 	    // a number cannot be determined before evaluating the 2nd
2230 	    // operand: if this is also a list, all is ok.
2231 	    // For "something . ...", "something - ..." or "non-list + ...",
2232 	    // we know that the first operand needs to be a string or number
2233 	    // without evaluating the 2nd operand.  So check before to avoid
2234 	    // side effects after an error.
2235 	    if ((flags & EVAL_EVALUATE) && tv_get_string_chk(rettv) == NULL)
2236 	    {
2237 		clear_tv(rettv);
2238 		return FAIL;
2239 	    }
2240 	}
2241 
2242 	/*
2243 	 * Get the second variable.
2244 	 */
2245 	if (op == '.' && *(*arg + 1) == '.')  // .. string concatenation
2246 	    ++*arg;
2247 	*arg = skipwhite(*arg + 1);
2248 	if (eval6(arg, &var2, flags, op == '.') == FAIL)
2249 	{
2250 	    clear_tv(rettv);
2251 	    return FAIL;
2252 	}
2253 
2254 	if (flags & EVAL_EVALUATE)
2255 	{
2256 	    /*
2257 	     * Compute the result.
2258 	     */
2259 	    if (op == '.')
2260 	    {
2261 		s1 = tv_get_string_buf(rettv, buf1);	// already checked
2262 		s2 = tv_get_string_buf_chk(&var2, buf2);
2263 		if (s2 == NULL)		// type error ?
2264 		{
2265 		    clear_tv(rettv);
2266 		    clear_tv(&var2);
2267 		    return FAIL;
2268 		}
2269 		p = concat_str(s1, s2);
2270 		clear_tv(rettv);
2271 		rettv->v_type = VAR_STRING;
2272 		rettv->vval.v_string = p;
2273 	    }
2274 	    else if (op == '+' && rettv->v_type == VAR_BLOB
2275 						   && var2.v_type == VAR_BLOB)
2276 		eval_addblob(rettv, &var2);
2277 	    else if (op == '+' && rettv->v_type == VAR_LIST
2278 						   && var2.v_type == VAR_LIST)
2279 	    {
2280 		if (eval_addlist(rettv, &var2) == FAIL)
2281 		    return FAIL;
2282 	    }
2283 	    else
2284 	    {
2285 		int	    error = FALSE;
2286 
2287 #ifdef FEAT_FLOAT
2288 		if (rettv->v_type == VAR_FLOAT)
2289 		{
2290 		    f1 = rettv->vval.v_float;
2291 		    n1 = 0;
2292 		}
2293 		else
2294 #endif
2295 		{
2296 		    n1 = tv_get_number_chk(rettv, &error);
2297 		    if (error)
2298 		    {
2299 			// This can only happen for "list + non-list".  For
2300 			// "non-list + ..." or "something - ...", we returned
2301 			// before evaluating the 2nd operand.
2302 			clear_tv(rettv);
2303 			return FAIL;
2304 		    }
2305 #ifdef FEAT_FLOAT
2306 		    if (var2.v_type == VAR_FLOAT)
2307 			f1 = n1;
2308 #endif
2309 		}
2310 #ifdef FEAT_FLOAT
2311 		if (var2.v_type == VAR_FLOAT)
2312 		{
2313 		    f2 = var2.vval.v_float;
2314 		    n2 = 0;
2315 		}
2316 		else
2317 #endif
2318 		{
2319 		    n2 = tv_get_number_chk(&var2, &error);
2320 		    if (error)
2321 		    {
2322 			clear_tv(rettv);
2323 			clear_tv(&var2);
2324 			return FAIL;
2325 		    }
2326 #ifdef FEAT_FLOAT
2327 		    if (rettv->v_type == VAR_FLOAT)
2328 			f2 = n2;
2329 #endif
2330 		}
2331 		clear_tv(rettv);
2332 
2333 #ifdef FEAT_FLOAT
2334 		// If there is a float on either side the result is a float.
2335 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
2336 		{
2337 		    if (op == '+')
2338 			f1 = f1 + f2;
2339 		    else
2340 			f1 = f1 - f2;
2341 		    rettv->v_type = VAR_FLOAT;
2342 		    rettv->vval.v_float = f1;
2343 		}
2344 		else
2345 #endif
2346 		{
2347 		    if (op == '+')
2348 			n1 = n1 + n2;
2349 		    else
2350 			n1 = n1 - n2;
2351 		    rettv->v_type = VAR_NUMBER;
2352 		    rettv->vval.v_number = n1;
2353 		}
2354 	    }
2355 	    clear_tv(&var2);
2356 	}
2357     }
2358     return OK;
2359 }
2360 
2361 /*
2362  * Handle fifth level expression:
2363  *	*	number multiplication
2364  *	/	number division
2365  *	%	number modulo
2366  *
2367  * "arg" must point to the first non-white of the expression.
2368  * "arg" is advanced to the next non-white after the recognized expression.
2369  *
2370  * Return OK or FAIL.
2371  */
2372     static int
2373 eval6(
2374     char_u	**arg,
2375     typval_T	*rettv,
2376     int		flags,
2377     int		want_string)  // after "." operator
2378 {
2379     typval_T	var2;
2380     int		op;
2381     varnumber_T	n1, n2;
2382 #ifdef FEAT_FLOAT
2383     int		use_float = FALSE;
2384     float_T	f1 = 0, f2 = 0;
2385 #endif
2386     int		error = FALSE;
2387 
2388     /*
2389      * Get the first variable.
2390      */
2391     if (eval7(arg, rettv, flags, want_string) == FAIL)
2392 	return FAIL;
2393 
2394     /*
2395      * Repeat computing, until no '*', '/' or '%' is following.
2396      */
2397     for (;;)
2398     {
2399 	op = **arg;
2400 	if (op != '*' && op != '/' && op != '%')
2401 	    break;
2402 
2403 	if (flags & EVAL_EVALUATE)
2404 	{
2405 #ifdef FEAT_FLOAT
2406 	    if (rettv->v_type == VAR_FLOAT)
2407 	    {
2408 		f1 = rettv->vval.v_float;
2409 		use_float = TRUE;
2410 		n1 = 0;
2411 	    }
2412 	    else
2413 #endif
2414 		n1 = tv_get_number_chk(rettv, &error);
2415 	    clear_tv(rettv);
2416 	    if (error)
2417 		return FAIL;
2418 	}
2419 	else
2420 	    n1 = 0;
2421 
2422 	/*
2423 	 * Get the second variable.
2424 	 */
2425 	*arg = skipwhite(*arg + 1);
2426 	if (eval7(arg, &var2, flags, FALSE) == FAIL)
2427 	    return FAIL;
2428 
2429 	if (flags & EVAL_EVALUATE)
2430 	{
2431 #ifdef FEAT_FLOAT
2432 	    if (var2.v_type == VAR_FLOAT)
2433 	    {
2434 		if (!use_float)
2435 		{
2436 		    f1 = n1;
2437 		    use_float = TRUE;
2438 		}
2439 		f2 = var2.vval.v_float;
2440 		n2 = 0;
2441 	    }
2442 	    else
2443 #endif
2444 	    {
2445 		n2 = tv_get_number_chk(&var2, &error);
2446 		clear_tv(&var2);
2447 		if (error)
2448 		    return FAIL;
2449 #ifdef FEAT_FLOAT
2450 		if (use_float)
2451 		    f2 = n2;
2452 #endif
2453 	    }
2454 
2455 	    /*
2456 	     * Compute the result.
2457 	     * When either side is a float the result is a float.
2458 	     */
2459 #ifdef FEAT_FLOAT
2460 	    if (use_float)
2461 	    {
2462 		if (op == '*')
2463 		    f1 = f1 * f2;
2464 		else if (op == '/')
2465 		{
2466 # ifdef VMS
2467 		    // VMS crashes on divide by zero, work around it
2468 		    if (f2 == 0.0)
2469 		    {
2470 			if (f1 == 0)
2471 			    f1 = -1 * __F_FLT_MAX - 1L;   // similar to NaN
2472 			else if (f1 < 0)
2473 			    f1 = -1 * __F_FLT_MAX;
2474 			else
2475 			    f1 = __F_FLT_MAX;
2476 		    }
2477 		    else
2478 			f1 = f1 / f2;
2479 # else
2480 		    // We rely on the floating point library to handle divide
2481 		    // by zero to result in "inf" and not a crash.
2482 		    f1 = f1 / f2;
2483 # endif
2484 		}
2485 		else
2486 		{
2487 		    emsg(_(e_modulus));
2488 		    return FAIL;
2489 		}
2490 		rettv->v_type = VAR_FLOAT;
2491 		rettv->vval.v_float = f1;
2492 	    }
2493 	    else
2494 #endif
2495 	    {
2496 		if (op == '*')
2497 		    n1 = n1 * n2;
2498 		else if (op == '/')
2499 		    n1 = num_divide(n1, n2);
2500 		else
2501 		    n1 = num_modulus(n1, n2);
2502 
2503 		rettv->v_type = VAR_NUMBER;
2504 		rettv->vval.v_number = n1;
2505 	    }
2506 	}
2507     }
2508 
2509     return OK;
2510 }
2511 
2512 /*
2513  * Handle sixth level expression:
2514  *  number		number constant
2515  *  0zFFFFFFFF		Blob constant
2516  *  "string"		string constant
2517  *  'string'		literal string constant
2518  *  &option-name	option value
2519  *  @r			register contents
2520  *  identifier		variable value
2521  *  function()		function call
2522  *  $VAR		environment variable
2523  *  (expression)	nested expression
2524  *  [expr, expr]	List
2525  *  {arg, arg -> expr}	Lambda
2526  *  {key: val, key: val}   Dictionary
2527  *  #{key: val, key: val}  Dictionary with literal keys
2528  *
2529  *  Also handle:
2530  *  ! in front		logical NOT
2531  *  - in front		unary minus
2532  *  + in front		unary plus (ignored)
2533  *  trailing []		subscript in String or List
2534  *  trailing .name	entry in Dictionary
2535  *  trailing ->name()	method call
2536  *
2537  * "arg" must point to the first non-white of the expression.
2538  * "arg" is advanced to the next non-white after the recognized expression.
2539  *
2540  * Return OK or FAIL.
2541  */
2542     static int
2543 eval7(
2544     char_u	**arg,
2545     typval_T	*rettv,
2546     int		flags,
2547     int		want_string)	// after "." operator
2548 {
2549     int		evaluate = flags & EVAL_EVALUATE;
2550     int		len;
2551     char_u	*s;
2552     char_u	*start_leader, *end_leader;
2553     int		ret = OK;
2554     char_u	*alias;
2555 
2556     /*
2557      * Initialise variable so that clear_tv() can't mistake this for a
2558      * string and free a string that isn't there.
2559      */
2560     rettv->v_type = VAR_UNKNOWN;
2561 
2562     /*
2563      * Skip '!', '-' and '+' characters.  They are handled later.
2564      */
2565     start_leader = *arg;
2566     while (**arg == '!' || **arg == '-' || **arg == '+')
2567 	*arg = skipwhite(*arg + 1);
2568     end_leader = *arg;
2569 
2570     if (**arg == '.' && (!isdigit(*(*arg + 1))
2571 #ifdef FEAT_FLOAT
2572 	    || current_sctx.sc_version < 2
2573 #endif
2574 	    ))
2575     {
2576 	semsg(_(e_invexpr2), *arg);
2577 	++*arg;
2578 	return FAIL;
2579     }
2580 
2581     switch (**arg)
2582     {
2583     /*
2584      * Number constant.
2585      */
2586     case '0':
2587     case '1':
2588     case '2':
2589     case '3':
2590     case '4':
2591     case '5':
2592     case '6':
2593     case '7':
2594     case '8':
2595     case '9':
2596     case '.':	ret = get_number_tv(arg, rettv, evaluate, want_string);
2597 		break;
2598 
2599     /*
2600      * String constant: "string".
2601      */
2602     case '"':	ret = get_string_tv(arg, rettv, evaluate);
2603 		break;
2604 
2605     /*
2606      * Literal string constant: 'str''ing'.
2607      */
2608     case '\'':	ret = get_lit_string_tv(arg, rettv, evaluate);
2609 		break;
2610 
2611     /*
2612      * List: [expr, expr]
2613      */
2614     case '[':	ret = get_list_tv(arg, rettv, flags, TRUE);
2615 		break;
2616 
2617     /*
2618      * Dictionary: #{key: val, key: val}
2619      */
2620     case '#':	if ((*arg)[1] == '{')
2621 		{
2622 		    ++*arg;
2623 		    ret = eval_dict(arg, rettv, flags, TRUE);
2624 		}
2625 		else
2626 		    ret = NOTDONE;
2627 		break;
2628 
2629     /*
2630      * Lambda: {arg, arg -> expr}
2631      * Dictionary: {'key': val, 'key': val}
2632      */
2633     case '{':	ret = get_lambda_tv(arg, rettv, evaluate);
2634 		if (ret == NOTDONE)
2635 		    ret = eval_dict(arg, rettv, flags, FALSE);
2636 		break;
2637 
2638     /*
2639      * Option value: &name
2640      */
2641     case '&':	ret = get_option_tv(arg, rettv, evaluate);
2642 		break;
2643 
2644     /*
2645      * Environment variable: $VAR.
2646      */
2647     case '$':	ret = get_env_tv(arg, rettv, evaluate);
2648 		break;
2649 
2650     /*
2651      * Register contents: @r.
2652      */
2653     case '@':	++*arg;
2654 		if (evaluate)
2655 		{
2656 		    rettv->v_type = VAR_STRING;
2657 		    rettv->vval.v_string = get_reg_contents(**arg,
2658 							    GREG_EXPR_SRC);
2659 		}
2660 		if (**arg != NUL)
2661 		    ++*arg;
2662 		break;
2663 
2664     /*
2665      * nested expression: (expression).
2666      */
2667     case '(':	*arg = skipwhite(*arg + 1);
2668 		ret = eval1(arg, rettv, flags);	// recursive!
2669 		if (**arg == ')')
2670 		    ++*arg;
2671 		else if (ret == OK)
2672 		{
2673 		    emsg(_(e_missing_close));
2674 		    clear_tv(rettv);
2675 		    ret = FAIL;
2676 		}
2677 		break;
2678 
2679     default:	ret = NOTDONE;
2680 		break;
2681     }
2682 
2683     if (ret == NOTDONE)
2684     {
2685 	/*
2686 	 * Must be a variable or function name.
2687 	 * Can also be a curly-braces kind of name: {expr}.
2688 	 */
2689 	s = *arg;
2690 	len = get_name_len(arg, &alias, evaluate, TRUE);
2691 	if (alias != NULL)
2692 	    s = alias;
2693 
2694 	if (len <= 0)
2695 	    ret = FAIL;
2696 	else
2697 	{
2698 	    if (**arg == '(')		// recursive!
2699 		ret = eval_func(arg, s, len, rettv, flags, NULL);
2700 	    else if (flags & EVAL_CONSTANT)
2701 		ret = FAIL;
2702 	    else if (evaluate)
2703 		ret = get_var_tv(s, len, rettv, NULL, TRUE, FALSE);
2704 	    else
2705 	    {
2706 		check_vars(s, len);
2707 		ret = OK;
2708 	    }
2709 	}
2710 	vim_free(alias);
2711     }
2712 
2713     *arg = skipwhite(*arg);
2714 
2715     // Handle following '[', '(' and '.' for expr[expr], expr.name,
2716     // expr(expr), expr->name(expr)
2717     if (ret == OK)
2718 	ret = handle_subscript(arg, rettv, flags, TRUE,
2719 						    start_leader, &end_leader);
2720 
2721     /*
2722      * Apply logical NOT and unary '-', from right to left, ignore '+'.
2723      */
2724     if (ret == OK && evaluate && end_leader > start_leader)
2725 	ret = eval7_leader(rettv, start_leader, &end_leader);
2726     return ret;
2727 }
2728 
2729 /*
2730  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
2731  * Adjusts "end_leaderp" until it is at "start_leader".
2732  */
2733     static int
2734 eval7_leader(typval_T *rettv, char_u *start_leader, char_u **end_leaderp)
2735 {
2736     char_u	*end_leader = *end_leaderp;
2737     int		ret = OK;
2738     int		error = FALSE;
2739     varnumber_T val = 0;
2740 #ifdef FEAT_FLOAT
2741     float_T	    f = 0.0;
2742 
2743     if (rettv->v_type == VAR_FLOAT)
2744 	f = rettv->vval.v_float;
2745     else
2746 #endif
2747 	val = tv_get_number_chk(rettv, &error);
2748     if (error)
2749     {
2750 	clear_tv(rettv);
2751 	ret = FAIL;
2752     }
2753     else
2754     {
2755 	while (end_leader > start_leader)
2756 	{
2757 	    --end_leader;
2758 	    if (*end_leader == '!')
2759 	    {
2760 #ifdef FEAT_FLOAT
2761 		if (rettv->v_type == VAR_FLOAT)
2762 		    f = !f;
2763 		else
2764 #endif
2765 		    val = !val;
2766 	    }
2767 	    else if (*end_leader == '-')
2768 	    {
2769 #ifdef FEAT_FLOAT
2770 		if (rettv->v_type == VAR_FLOAT)
2771 		    f = -f;
2772 		else
2773 #endif
2774 		    val = -val;
2775 	    }
2776 	}
2777 #ifdef FEAT_FLOAT
2778 	if (rettv->v_type == VAR_FLOAT)
2779 	{
2780 	    clear_tv(rettv);
2781 	    rettv->vval.v_float = f;
2782 	}
2783 	else
2784 #endif
2785 	{
2786 	    clear_tv(rettv);
2787 	    rettv->v_type = VAR_NUMBER;
2788 	    rettv->vval.v_number = val;
2789 	}
2790     }
2791     *end_leaderp = end_leader;
2792     return ret;
2793 }
2794 
2795 /*
2796  * Call the function referred to in "rettv".
2797  */
2798     static int
2799 call_func_rettv(
2800 	char_u	    **arg,
2801 	typval_T    *rettv,
2802 	int	    evaluate,
2803 	dict_T	    *selfdict,
2804 	typval_T    *basetv)
2805 {
2806     partial_T	*pt = NULL;
2807     funcexe_T	funcexe;
2808     typval_T	functv;
2809     char_u	*s;
2810     int		ret;
2811 
2812     // need to copy the funcref so that we can clear rettv
2813     if (evaluate)
2814     {
2815 	functv = *rettv;
2816 	rettv->v_type = VAR_UNKNOWN;
2817 
2818 	// Invoke the function.  Recursive!
2819 	if (functv.v_type == VAR_PARTIAL)
2820 	{
2821 	    pt = functv.vval.v_partial;
2822 	    s = partial_name(pt);
2823 	}
2824 	else
2825 	    s = functv.vval.v_string;
2826     }
2827     else
2828 	s = (char_u *)"";
2829 
2830     CLEAR_FIELD(funcexe);
2831     funcexe.firstline = curwin->w_cursor.lnum;
2832     funcexe.lastline = curwin->w_cursor.lnum;
2833     funcexe.evaluate = evaluate;
2834     funcexe.partial = pt;
2835     funcexe.selfdict = selfdict;
2836     funcexe.basetv = basetv;
2837     ret = get_func_tv(s, -1, rettv, arg, &funcexe);
2838 
2839     // Clear the funcref afterwards, so that deleting it while
2840     // evaluating the arguments is possible (see test55).
2841     if (evaluate)
2842 	clear_tv(&functv);
2843 
2844     return ret;
2845 }
2846 
2847 /*
2848  * Evaluate "->method()".
2849  * "*arg" points to the '-'.
2850  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
2851  */
2852     static int
2853 eval_lambda(
2854     char_u	**arg,
2855     typval_T	*rettv,
2856     int		evaluate,
2857     int		verbose)	// give error messages
2858 {
2859     typval_T	base = *rettv;
2860     int		ret;
2861 
2862     // Skip over the ->.
2863     *arg += 2;
2864     rettv->v_type = VAR_UNKNOWN;
2865 
2866     ret = get_lambda_tv(arg, rettv, evaluate);
2867     if (ret != OK)
2868 	return FAIL;
2869     else if (**arg != '(')
2870     {
2871 	if (verbose)
2872 	{
2873 	    if (*skipwhite(*arg) == '(')
2874 		emsg(_(e_nowhitespace));
2875 	    else
2876 		semsg(_(e_missing_paren), "lambda");
2877 	}
2878 	clear_tv(rettv);
2879 	ret = FAIL;
2880     }
2881     else
2882 	ret = call_func_rettv(arg, rettv, evaluate, NULL, &base);
2883 
2884     // Clear the funcref afterwards, so that deleting it while
2885     // evaluating the arguments is possible (see test55).
2886     if (evaluate)
2887 	clear_tv(&base);
2888 
2889     return ret;
2890 }
2891 
2892 /*
2893  * Evaluate "->method()".
2894  * "*arg" points to the '-'.
2895  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
2896  */
2897     static int
2898 eval_method(
2899     char_u	**arg,
2900     typval_T	*rettv,
2901     int		evaluate,
2902     int		verbose)	// give error messages
2903 {
2904     char_u	*name;
2905     long	len;
2906     char_u	*alias;
2907     typval_T	base = *rettv;
2908     int		ret;
2909 
2910     // Skip over the ->.
2911     *arg += 2;
2912     rettv->v_type = VAR_UNKNOWN;
2913 
2914     name = *arg;
2915     len = get_name_len(arg, &alias, evaluate, TRUE);
2916     if (alias != NULL)
2917 	name = alias;
2918 
2919     if (len <= 0)
2920     {
2921 	if (verbose)
2922 	    emsg(_("E260: Missing name after ->"));
2923 	ret = FAIL;
2924     }
2925     else
2926     {
2927 	if (**arg != '(')
2928 	{
2929 	    if (verbose)
2930 		semsg(_(e_missing_paren), name);
2931 	    ret = FAIL;
2932 	}
2933 	else if (VIM_ISWHITE((*arg)[-1]))
2934 	{
2935 	    if (verbose)
2936 		emsg(_(e_nowhitespace));
2937 	    ret = FAIL;
2938 	}
2939 	else
2940 	    ret = eval_func(arg, name, len, rettv,
2941 					  evaluate ? EVAL_EVALUATE : 0, &base);
2942     }
2943 
2944     // Clear the funcref afterwards, so that deleting it while
2945     // evaluating the arguments is possible (see test55).
2946     if (evaluate)
2947 	clear_tv(&base);
2948 
2949     return ret;
2950 }
2951 
2952 /*
2953  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
2954  * "*arg" points to the '[' or '.'.
2955  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
2956  */
2957     static int
2958 eval_index(
2959     char_u	**arg,
2960     typval_T	*rettv,
2961     int		flags,
2962     int		verbose)	// give error messages
2963 {
2964     int		evaluate = flags & EVAL_EVALUATE;
2965     int		empty1 = FALSE, empty2 = FALSE;
2966     typval_T	var1, var2;
2967     long	i;
2968     long	n1, n2 = 0;
2969     long	len = -1;
2970     int		range = FALSE;
2971     char_u	*s;
2972     char_u	*key = NULL;
2973 
2974     switch (rettv->v_type)
2975     {
2976 	case VAR_FUNC:
2977 	case VAR_PARTIAL:
2978 	    if (verbose)
2979 		emsg(_("E695: Cannot index a Funcref"));
2980 	    return FAIL;
2981 	case VAR_FLOAT:
2982 #ifdef FEAT_FLOAT
2983 	    if (verbose)
2984 		emsg(_(e_float_as_string));
2985 	    return FAIL;
2986 #endif
2987 	case VAR_BOOL:
2988 	case VAR_SPECIAL:
2989 	case VAR_JOB:
2990 	case VAR_CHANNEL:
2991 	    if (verbose)
2992 		emsg(_("E909: Cannot index a special variable"));
2993 	    return FAIL;
2994 	case VAR_UNKNOWN:
2995 	case VAR_ANY:
2996 	case VAR_VOID:
2997 	    if (evaluate)
2998 		return FAIL;
2999 	    // FALLTHROUGH
3000 
3001 	case VAR_STRING:
3002 	case VAR_NUMBER:
3003 	case VAR_LIST:
3004 	case VAR_DICT:
3005 	case VAR_BLOB:
3006 	    break;
3007     }
3008 
3009     init_tv(&var1);
3010     init_tv(&var2);
3011     if (**arg == '.')
3012     {
3013 	/*
3014 	 * dict.name
3015 	 */
3016 	key = *arg + 1;
3017 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
3018 	    ;
3019 	if (len == 0)
3020 	    return FAIL;
3021 	*arg = skipwhite(key + len);
3022     }
3023     else
3024     {
3025 	/*
3026 	 * something[idx]
3027 	 *
3028 	 * Get the (first) variable from inside the [].
3029 	 */
3030 	*arg = skipwhite(*arg + 1);
3031 	if (**arg == ':')
3032 	    empty1 = TRUE;
3033 	else if (eval1(arg, &var1, flags) == FAIL)	// recursive!
3034 	    return FAIL;
3035 	else if (evaluate && tv_get_string_chk(&var1) == NULL)
3036 	{
3037 	    // not a number or string
3038 	    clear_tv(&var1);
3039 	    return FAIL;
3040 	}
3041 
3042 	/*
3043 	 * Get the second variable from inside the [:].
3044 	 */
3045 	if (**arg == ':')
3046 	{
3047 	    range = TRUE;
3048 	    *arg = skipwhite(*arg + 1);
3049 	    if (**arg == ']')
3050 		empty2 = TRUE;
3051 	    else if (eval1(arg, &var2, flags) == FAIL)	// recursive!
3052 	    {
3053 		if (!empty1)
3054 		    clear_tv(&var1);
3055 		return FAIL;
3056 	    }
3057 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
3058 	    {
3059 		// not a number or string
3060 		if (!empty1)
3061 		    clear_tv(&var1);
3062 		clear_tv(&var2);
3063 		return FAIL;
3064 	    }
3065 	}
3066 
3067 	// Check for the ']'.
3068 	if (**arg != ']')
3069 	{
3070 	    if (verbose)
3071 		emsg(_(e_missbrac));
3072 	    clear_tv(&var1);
3073 	    if (range)
3074 		clear_tv(&var2);
3075 	    return FAIL;
3076 	}
3077 	*arg = skipwhite(*arg + 1);	// skip the ']'
3078     }
3079 
3080     if (evaluate)
3081     {
3082 	n1 = 0;
3083 	if (!empty1 && rettv->v_type != VAR_DICT)
3084 	{
3085 	    n1 = tv_get_number(&var1);
3086 	    clear_tv(&var1);
3087 	}
3088 	if (range)
3089 	{
3090 	    if (empty2)
3091 		n2 = -1;
3092 	    else
3093 	    {
3094 		n2 = tv_get_number(&var2);
3095 		clear_tv(&var2);
3096 	    }
3097 	}
3098 
3099 	switch (rettv->v_type)
3100 	{
3101 	    case VAR_UNKNOWN:
3102 	    case VAR_ANY:
3103 	    case VAR_VOID:
3104 	    case VAR_FUNC:
3105 	    case VAR_PARTIAL:
3106 	    case VAR_FLOAT:
3107 	    case VAR_BOOL:
3108 	    case VAR_SPECIAL:
3109 	    case VAR_JOB:
3110 	    case VAR_CHANNEL:
3111 		break; // not evaluating, skipping over subscript
3112 
3113 	    case VAR_NUMBER:
3114 	    case VAR_STRING:
3115 		s = tv_get_string(rettv);
3116 		len = (long)STRLEN(s);
3117 		if (range)
3118 		{
3119 		    // The resulting variable is a substring.  If the indexes
3120 		    // are out of range the result is empty.
3121 		    if (n1 < 0)
3122 		    {
3123 			n1 = len + n1;
3124 			if (n1 < 0)
3125 			    n1 = 0;
3126 		    }
3127 		    if (n2 < 0)
3128 			n2 = len + n2;
3129 		    else if (n2 >= len)
3130 			n2 = len;
3131 		    if (n1 >= len || n2 < 0 || n1 > n2)
3132 			s = NULL;
3133 		    else
3134 			s = vim_strnsave(s + n1, (int)(n2 - n1 + 1));
3135 		}
3136 		else
3137 		{
3138 		    // The resulting variable is a string of a single
3139 		    // character.  If the index is too big or negative the
3140 		    // result is empty.
3141 		    if (n1 >= len || n1 < 0)
3142 			s = NULL;
3143 		    else
3144 			s = vim_strnsave(s + n1, 1);
3145 		}
3146 		clear_tv(rettv);
3147 		rettv->v_type = VAR_STRING;
3148 		rettv->vval.v_string = s;
3149 		break;
3150 
3151 	    case VAR_BLOB:
3152 		len = blob_len(rettv->vval.v_blob);
3153 		if (range)
3154 		{
3155 		    // The resulting variable is a sub-blob.  If the indexes
3156 		    // are out of range the result is empty.
3157 		    if (n1 < 0)
3158 		    {
3159 			n1 = len + n1;
3160 			if (n1 < 0)
3161 			    n1 = 0;
3162 		    }
3163 		    if (n2 < 0)
3164 			n2 = len + n2;
3165 		    else if (n2 >= len)
3166 			n2 = len - 1;
3167 		    if (n1 >= len || n2 < 0 || n1 > n2)
3168 		    {
3169 			clear_tv(rettv);
3170 			rettv->v_type = VAR_BLOB;
3171 			rettv->vval.v_blob = NULL;
3172 		    }
3173 		    else
3174 		    {
3175 			blob_T  *blob = blob_alloc();
3176 
3177 			if (blob != NULL)
3178 			{
3179 			    if (ga_grow(&blob->bv_ga, n2 - n1 + 1) == FAIL)
3180 			    {
3181 				blob_free(blob);
3182 				return FAIL;
3183 			    }
3184 			    blob->bv_ga.ga_len = n2 - n1 + 1;
3185 			    for (i = n1; i <= n2; i++)
3186 				blob_set(blob, i - n1,
3187 					      blob_get(rettv->vval.v_blob, i));
3188 
3189 			    clear_tv(rettv);
3190 			    rettv_blob_set(rettv, blob);
3191 			}
3192 		    }
3193 		}
3194 		else
3195 		{
3196 		    // The resulting variable is a byte value.
3197 		    // If the index is too big or negative that is an error.
3198 		    if (n1 < 0)
3199 			n1 = len + n1;
3200 		    if (n1 < len && n1 >= 0)
3201 		    {
3202 			int v = blob_get(rettv->vval.v_blob, n1);
3203 
3204 			clear_tv(rettv);
3205 			rettv->v_type = VAR_NUMBER;
3206 			rettv->vval.v_number = v;
3207 		    }
3208 		    else
3209 			semsg(_(e_blobidx), n1);
3210 		}
3211 		break;
3212 
3213 	    case VAR_LIST:
3214 		len = list_len(rettv->vval.v_list);
3215 		if (n1 < 0)
3216 		    n1 = len + n1;
3217 		if (!empty1 && (n1 < 0 || n1 >= len))
3218 		{
3219 		    // For a range we allow invalid values and return an empty
3220 		    // list.  A list index out of range is an error.
3221 		    if (!range)
3222 		    {
3223 			if (verbose)
3224 			    semsg(_(e_listidx), n1);
3225 			return FAIL;
3226 		    }
3227 		    n1 = len;
3228 		}
3229 		if (range)
3230 		{
3231 		    list_T	*l;
3232 		    listitem_T	*item;
3233 
3234 		    if (n2 < 0)
3235 			n2 = len + n2;
3236 		    else if (n2 >= len)
3237 			n2 = len - 1;
3238 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
3239 			n2 = -1;
3240 		    l = list_alloc();
3241 		    if (l == NULL)
3242 			return FAIL;
3243 		    for (item = list_find(rettv->vval.v_list, n1);
3244 							       n1 <= n2; ++n1)
3245 		    {
3246 			if (list_append_tv(l, &item->li_tv) == FAIL)
3247 			{
3248 			    list_free(l);
3249 			    return FAIL;
3250 			}
3251 			item = item->li_next;
3252 		    }
3253 		    clear_tv(rettv);
3254 		    rettv_list_set(rettv, l);
3255 		}
3256 		else
3257 		{
3258 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
3259 		    clear_tv(rettv);
3260 		    *rettv = var1;
3261 		}
3262 		break;
3263 
3264 	    case VAR_DICT:
3265 		if (range)
3266 		{
3267 		    if (verbose)
3268 			emsg(_(e_dictrange));
3269 		    if (len == -1)
3270 			clear_tv(&var1);
3271 		    return FAIL;
3272 		}
3273 		{
3274 		    dictitem_T	*item;
3275 
3276 		    if (len == -1)
3277 		    {
3278 			key = tv_get_string_chk(&var1);
3279 			if (key == NULL)
3280 			{
3281 			    clear_tv(&var1);
3282 			    return FAIL;
3283 			}
3284 		    }
3285 
3286 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
3287 
3288 		    if (item == NULL && verbose)
3289 			semsg(_(e_dictkey), key);
3290 		    if (len == -1)
3291 			clear_tv(&var1);
3292 		    if (item == NULL)
3293 			return FAIL;
3294 
3295 		    copy_tv(&item->di_tv, &var1);
3296 		    clear_tv(rettv);
3297 		    *rettv = var1;
3298 		}
3299 		break;
3300 	}
3301     }
3302 
3303     return OK;
3304 }
3305 
3306 /*
3307  * Get an option value.
3308  * "arg" points to the '&' or '+' before the option name.
3309  * "arg" is advanced to character after the option name.
3310  * Return OK or FAIL.
3311  */
3312     int
3313 get_option_tv(
3314     char_u	**arg,
3315     typval_T	*rettv,	// when NULL, only check if option exists
3316     int		evaluate)
3317 {
3318     char_u	*option_end;
3319     long	numval;
3320     char_u	*stringval;
3321     int		opt_type;
3322     int		c;
3323     int		working = (**arg == '+');    // has("+option")
3324     int		ret = OK;
3325     int		opt_flags;
3326 
3327     /*
3328      * Isolate the option name and find its value.
3329      */
3330     option_end = find_option_end(arg, &opt_flags);
3331     if (option_end == NULL)
3332     {
3333 	if (rettv != NULL)
3334 	    semsg(_("E112: Option name missing: %s"), *arg);
3335 	return FAIL;
3336     }
3337 
3338     if (!evaluate)
3339     {
3340 	*arg = option_end;
3341 	return OK;
3342     }
3343 
3344     c = *option_end;
3345     *option_end = NUL;
3346     opt_type = get_option_value(*arg, &numval,
3347 			       rettv == NULL ? NULL : &stringval, opt_flags);
3348 
3349     if (opt_type == -3)			// invalid name
3350     {
3351 	if (rettv != NULL)
3352 	    semsg(_(e_unknown_option), *arg);
3353 	ret = FAIL;
3354     }
3355     else if (rettv != NULL)
3356     {
3357 	if (opt_type == -2)		// hidden string option
3358 	{
3359 	    rettv->v_type = VAR_STRING;
3360 	    rettv->vval.v_string = NULL;
3361 	}
3362 	else if (opt_type == -1)	// hidden number option
3363 	{
3364 	    rettv->v_type = VAR_NUMBER;
3365 	    rettv->vval.v_number = 0;
3366 	}
3367 	else if (opt_type == 1)		// number option
3368 	{
3369 	    rettv->v_type = VAR_NUMBER;
3370 	    rettv->vval.v_number = numval;
3371 	}
3372 	else				// string option
3373 	{
3374 	    rettv->v_type = VAR_STRING;
3375 	    rettv->vval.v_string = stringval;
3376 	}
3377     }
3378     else if (working && (opt_type == -2 || opt_type == -1))
3379 	ret = FAIL;
3380 
3381     *option_end = c;		    // put back for error messages
3382     *arg = option_end;
3383 
3384     return ret;
3385 }
3386 
3387 /*
3388  * Allocate a variable for a number constant.  Also deals with "0z" for blob.
3389  * Return OK or FAIL.
3390  */
3391     int
3392 get_number_tv(
3393 	char_u	    **arg,
3394 	typval_T    *rettv,
3395 	int	    evaluate,
3396 	int	    want_string UNUSED)
3397 {
3398     int		len;
3399 #ifdef FEAT_FLOAT
3400     char_u	*p;
3401     int		get_float = FALSE;
3402 
3403     // We accept a float when the format matches
3404     // "[0-9]\+\.[0-9]\+\([eE][+-]\?[0-9]\+\)\?".  This is very
3405     // strict to avoid backwards compatibility problems.
3406     // With script version 2 and later the leading digit can be
3407     // omitted.
3408     // Don't look for a float after the "." operator, so that
3409     // ":let vers = 1.2.3" doesn't fail.
3410     if (**arg == '.')
3411 	p = *arg;
3412     else
3413 	p = skipdigits(*arg + 1);
3414     if (!want_string && p[0] == '.' && vim_isdigit(p[1]))
3415     {
3416 	get_float = TRUE;
3417 	p = skipdigits(p + 2);
3418 	if (*p == 'e' || *p == 'E')
3419 	{
3420 	    ++p;
3421 	    if (*p == '-' || *p == '+')
3422 		++p;
3423 	    if (!vim_isdigit(*p))
3424 		get_float = FALSE;
3425 	    else
3426 		p = skipdigits(p + 1);
3427 	}
3428 	if (ASCII_ISALPHA(*p) || *p == '.')
3429 	    get_float = FALSE;
3430     }
3431     if (get_float)
3432     {
3433 	float_T	f;
3434 
3435 	*arg += string2float(*arg, &f);
3436 	if (evaluate)
3437 	{
3438 	    rettv->v_type = VAR_FLOAT;
3439 	    rettv->vval.v_float = f;
3440 	}
3441     }
3442     else
3443 #endif
3444     if (**arg == '0' && ((*arg)[1] == 'z' || (*arg)[1] == 'Z'))
3445     {
3446 	char_u  *bp;
3447 	blob_T  *blob = NULL;  // init for gcc
3448 
3449 	// Blob constant: 0z0123456789abcdef
3450 	if (evaluate)
3451 	    blob = blob_alloc();
3452 	for (bp = *arg + 2; vim_isxdigit(bp[0]); bp += 2)
3453 	{
3454 	    if (!vim_isxdigit(bp[1]))
3455 	    {
3456 		if (blob != NULL)
3457 		{
3458 		    emsg(_("E973: Blob literal should have an even number of hex characters"));
3459 		    ga_clear(&blob->bv_ga);
3460 		    VIM_CLEAR(blob);
3461 		}
3462 		return FAIL;
3463 	    }
3464 	    if (blob != NULL)
3465 		ga_append(&blob->bv_ga,
3466 			     (hex2nr(*bp) << 4) + hex2nr(*(bp+1)));
3467 	    if (bp[2] == '.' && vim_isxdigit(bp[3]))
3468 		++bp;
3469 	}
3470 	if (blob != NULL)
3471 	    rettv_blob_set(rettv, blob);
3472 	*arg = bp;
3473     }
3474     else
3475     {
3476 	varnumber_T	n;
3477 
3478 	// decimal, hex or octal number
3479 	vim_str2nr(*arg, NULL, &len, current_sctx.sc_version >= 4
3480 		      ? STR2NR_NO_OCT + STR2NR_QUOTE
3481 		      : STR2NR_ALL, &n, NULL, 0, TRUE);
3482 	if (len == 0)
3483 	{
3484 	    semsg(_(e_invexpr2), *arg);
3485 	    return FAIL;
3486 	}
3487 	*arg += len;
3488 	if (evaluate)
3489 	{
3490 	    rettv->v_type = VAR_NUMBER;
3491 	    rettv->vval.v_number = n;
3492 	}
3493     }
3494     return OK;
3495 }
3496 
3497 /*
3498  * Allocate a variable for a string constant.
3499  * Return OK or FAIL.
3500  */
3501     int
3502 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
3503 {
3504     char_u	*p;
3505     char_u	*name;
3506     int		extra = 0;
3507     int		len;
3508 
3509     /*
3510      * Find the end of the string, skipping backslashed characters.
3511      */
3512     for (p = *arg + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
3513     {
3514 	if (*p == '\\' && p[1] != NUL)
3515 	{
3516 	    ++p;
3517 	    // A "\<x>" form occupies at least 4 characters, and produces up
3518 	    // to 21 characters (3 * 6 for the char and 3 for a modifier):
3519 	    // reserve space for 18 extra.
3520 	    // Each byte in the char could be encoded as K_SPECIAL K_EXTRA x.
3521 	    if (*p == '<')
3522 		extra += 18;
3523 	}
3524     }
3525 
3526     if (*p != '"')
3527     {
3528 	semsg(_("E114: Missing quote: %s"), *arg);
3529 	return FAIL;
3530     }
3531 
3532     // If only parsing, set *arg and return here
3533     if (!evaluate)
3534     {
3535 	*arg = p + 1;
3536 	return OK;
3537     }
3538 
3539     /*
3540      * Copy the string into allocated memory, handling backslashed
3541      * characters.
3542      */
3543     len = (int)(p - *arg + extra);
3544     name = alloc(len);
3545     if (name == NULL)
3546 	return FAIL;
3547     rettv->v_type = VAR_STRING;
3548     rettv->vval.v_string = name;
3549 
3550     for (p = *arg + 1; *p != NUL && *p != '"'; )
3551     {
3552 	if (*p == '\\')
3553 	{
3554 	    switch (*++p)
3555 	    {
3556 		case 'b': *name++ = BS; ++p; break;
3557 		case 'e': *name++ = ESC; ++p; break;
3558 		case 'f': *name++ = FF; ++p; break;
3559 		case 'n': *name++ = NL; ++p; break;
3560 		case 'r': *name++ = CAR; ++p; break;
3561 		case 't': *name++ = TAB; ++p; break;
3562 
3563 		case 'X': // hex: "\x1", "\x12"
3564 		case 'x':
3565 		case 'u': // Unicode: "\u0023"
3566 		case 'U':
3567 			  if (vim_isxdigit(p[1]))
3568 			  {
3569 			      int	n, nr;
3570 			      int	c = toupper(*p);
3571 
3572 			      if (c == 'X')
3573 				  n = 2;
3574 			      else if (*p == 'u')
3575 				  n = 4;
3576 			      else
3577 				  n = 8;
3578 			      nr = 0;
3579 			      while (--n >= 0 && vim_isxdigit(p[1]))
3580 			      {
3581 				  ++p;
3582 				  nr = (nr << 4) + hex2nr(*p);
3583 			      }
3584 			      ++p;
3585 			      // For "\u" store the number according to
3586 			      // 'encoding'.
3587 			      if (c != 'X')
3588 				  name += (*mb_char2bytes)(nr, name);
3589 			      else
3590 				  *name++ = nr;
3591 			  }
3592 			  break;
3593 
3594 			  // octal: "\1", "\12", "\123"
3595 		case '0':
3596 		case '1':
3597 		case '2':
3598 		case '3':
3599 		case '4':
3600 		case '5':
3601 		case '6':
3602 		case '7': *name = *p++ - '0';
3603 			  if (*p >= '0' && *p <= '7')
3604 			  {
3605 			      *name = (*name << 3) + *p++ - '0';
3606 			      if (*p >= '0' && *p <= '7')
3607 				  *name = (*name << 3) + *p++ - '0';
3608 			  }
3609 			  ++name;
3610 			  break;
3611 
3612 			    // Special key, e.g.: "\<C-W>"
3613 		case '<': extra = trans_special(&p, name, TRUE, TRUE,
3614 								   TRUE, NULL);
3615 			  if (extra != 0)
3616 			  {
3617 			      name += extra;
3618 			      if (name >= rettv->vval.v_string + len)
3619 				  iemsg("get_string_tv() used more space than allocated");
3620 			      break;
3621 			  }
3622 			  // FALLTHROUGH
3623 
3624 		default:  MB_COPY_CHAR(p, name);
3625 			  break;
3626 	    }
3627 	}
3628 	else
3629 	    MB_COPY_CHAR(p, name);
3630 
3631     }
3632     *name = NUL;
3633     if (*p != NUL) // just in case
3634 	++p;
3635     *arg = p;
3636 
3637     return OK;
3638 }
3639 
3640 /*
3641  * Allocate a variable for a 'str''ing' constant.
3642  * Return OK or FAIL.
3643  */
3644     int
3645 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
3646 {
3647     char_u	*p;
3648     char_u	*str;
3649     int		reduce = 0;
3650 
3651     /*
3652      * Find the end of the string, skipping ''.
3653      */
3654     for (p = *arg + 1; *p != NUL; MB_PTR_ADV(p))
3655     {
3656 	if (*p == '\'')
3657 	{
3658 	    if (p[1] != '\'')
3659 		break;
3660 	    ++reduce;
3661 	    ++p;
3662 	}
3663     }
3664 
3665     if (*p != '\'')
3666     {
3667 	semsg(_("E115: Missing quote: %s"), *arg);
3668 	return FAIL;
3669     }
3670 
3671     // If only parsing return after setting "*arg"
3672     if (!evaluate)
3673     {
3674 	*arg = p + 1;
3675 	return OK;
3676     }
3677 
3678     /*
3679      * Copy the string into allocated memory, handling '' to ' reduction.
3680      */
3681     str = alloc((p - *arg) - reduce);
3682     if (str == NULL)
3683 	return FAIL;
3684     rettv->v_type = VAR_STRING;
3685     rettv->vval.v_string = str;
3686 
3687     for (p = *arg + 1; *p != NUL; )
3688     {
3689 	if (*p == '\'')
3690 	{
3691 	    if (p[1] != '\'')
3692 		break;
3693 	    ++p;
3694 	}
3695 	MB_COPY_CHAR(p, str);
3696     }
3697     *str = NUL;
3698     *arg = p + 1;
3699 
3700     return OK;
3701 }
3702 
3703 /*
3704  * Return the function name of partial "pt".
3705  */
3706     char_u *
3707 partial_name(partial_T *pt)
3708 {
3709     if (pt->pt_name != NULL)
3710 	return pt->pt_name;
3711     if (pt->pt_func != NULL)
3712 	return pt->pt_func->uf_name;
3713     return (char_u *)"";
3714 }
3715 
3716     static void
3717 partial_free(partial_T *pt)
3718 {
3719     int i;
3720 
3721     for (i = 0; i < pt->pt_argc; ++i)
3722 	clear_tv(&pt->pt_argv[i]);
3723     vim_free(pt->pt_argv);
3724     dict_unref(pt->pt_dict);
3725     if (pt->pt_name != NULL)
3726     {
3727 	func_unref(pt->pt_name);
3728 	vim_free(pt->pt_name);
3729     }
3730     else
3731 	func_ptr_unref(pt->pt_func);
3732 
3733     if (pt->pt_funcstack != NULL)
3734     {
3735 	// Decrease the reference count for the context of a closure.  If down
3736 	// to zero free it and clear the variables on the stack.
3737 	if (--pt->pt_funcstack->fs_refcount == 0)
3738 	{
3739 	    garray_T	*gap = &pt->pt_funcstack->fs_ga;
3740 	    typval_T	*stack = gap->ga_data;
3741 
3742 	    for (i = 0; i < gap->ga_len; ++i)
3743 		clear_tv(stack + i);
3744 	    ga_clear(gap);
3745 	    vim_free(pt->pt_funcstack);
3746 	}
3747 	pt->pt_funcstack = NULL;
3748     }
3749 
3750     vim_free(pt);
3751 }
3752 
3753 /*
3754  * Unreference a closure: decrement the reference count and free it when it
3755  * becomes zero.
3756  */
3757     void
3758 partial_unref(partial_T *pt)
3759 {
3760     if (pt != NULL && --pt->pt_refcount <= 0)
3761 	partial_free(pt);
3762 }
3763 
3764 static int tv_equal_recurse_limit;
3765 
3766     static int
3767 func_equal(
3768     typval_T *tv1,
3769     typval_T *tv2,
3770     int	     ic)	    // ignore case
3771 {
3772     char_u	*s1, *s2;
3773     dict_T	*d1, *d2;
3774     int		a1, a2;
3775     int		i;
3776 
3777     // empty and NULL function name considered the same
3778     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
3779 					   : partial_name(tv1->vval.v_partial);
3780     if (s1 != NULL && *s1 == NUL)
3781 	s1 = NULL;
3782     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
3783 					   : partial_name(tv2->vval.v_partial);
3784     if (s2 != NULL && *s2 == NUL)
3785 	s2 = NULL;
3786     if (s1 == NULL || s2 == NULL)
3787     {
3788 	if (s1 != s2)
3789 	    return FALSE;
3790     }
3791     else if (STRCMP(s1, s2) != 0)
3792 	return FALSE;
3793 
3794     // empty dict and NULL dict is different
3795     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
3796     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
3797     if (d1 == NULL || d2 == NULL)
3798     {
3799 	if (d1 != d2)
3800 	    return FALSE;
3801     }
3802     else if (!dict_equal(d1, d2, ic, TRUE))
3803 	return FALSE;
3804 
3805     // empty list and no list considered the same
3806     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
3807     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
3808     if (a1 != a2)
3809 	return FALSE;
3810     for (i = 0; i < a1; ++i)
3811 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
3812 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
3813 	    return FALSE;
3814 
3815     return TRUE;
3816 }
3817 
3818 /*
3819  * Return TRUE if "tv1" and "tv2" have the same value.
3820  * Compares the items just like "==" would compare them, but strings and
3821  * numbers are different.  Floats and numbers are also different.
3822  */
3823     int
3824 tv_equal(
3825     typval_T *tv1,
3826     typval_T *tv2,
3827     int	     ic,	    // ignore case
3828     int	     recursive)	    // TRUE when used recursively
3829 {
3830     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3831     char_u	*s1, *s2;
3832     static int  recursive_cnt = 0;	    // catch recursive loops
3833     int		r;
3834 
3835     // Catch lists and dicts that have an endless loop by limiting
3836     // recursiveness to a limit.  We guess they are equal then.
3837     // A fixed limit has the problem of still taking an awful long time.
3838     // Reduce the limit every time running into it. That should work fine for
3839     // deeply linked structures that are not recursively linked and catch
3840     // recursiveness quickly.
3841     if (!recursive)
3842 	tv_equal_recurse_limit = 1000;
3843     if (recursive_cnt >= tv_equal_recurse_limit)
3844     {
3845 	--tv_equal_recurse_limit;
3846 	return TRUE;
3847     }
3848 
3849     // For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
3850     // arguments.
3851     if ((tv1->v_type == VAR_FUNC
3852 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
3853 	    && (tv2->v_type == VAR_FUNC
3854 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
3855     {
3856 	++recursive_cnt;
3857 	r = func_equal(tv1, tv2, ic);
3858 	--recursive_cnt;
3859 	return r;
3860     }
3861 
3862     if (tv1->v_type != tv2->v_type)
3863 	return FALSE;
3864 
3865     switch (tv1->v_type)
3866     {
3867 	case VAR_LIST:
3868 	    ++recursive_cnt;
3869 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
3870 	    --recursive_cnt;
3871 	    return r;
3872 
3873 	case VAR_DICT:
3874 	    ++recursive_cnt;
3875 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
3876 	    --recursive_cnt;
3877 	    return r;
3878 
3879 	case VAR_BLOB:
3880 	    return blob_equal(tv1->vval.v_blob, tv2->vval.v_blob);
3881 
3882 	case VAR_NUMBER:
3883 	case VAR_BOOL:
3884 	case VAR_SPECIAL:
3885 	    return tv1->vval.v_number == tv2->vval.v_number;
3886 
3887 	case VAR_STRING:
3888 	    s1 = tv_get_string_buf(tv1, buf1);
3889 	    s2 = tv_get_string_buf(tv2, buf2);
3890 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
3891 
3892 	case VAR_FLOAT:
3893 #ifdef FEAT_FLOAT
3894 	    return tv1->vval.v_float == tv2->vval.v_float;
3895 #endif
3896 	case VAR_JOB:
3897 #ifdef FEAT_JOB_CHANNEL
3898 	    return tv1->vval.v_job == tv2->vval.v_job;
3899 #endif
3900 	case VAR_CHANNEL:
3901 #ifdef FEAT_JOB_CHANNEL
3902 	    return tv1->vval.v_channel == tv2->vval.v_channel;
3903 #endif
3904 
3905 	case VAR_PARTIAL:
3906 	    return tv1->vval.v_partial == tv2->vval.v_partial;
3907 
3908 	case VAR_FUNC:
3909 	    return tv1->vval.v_string == tv2->vval.v_string;
3910 
3911 	case VAR_UNKNOWN:
3912 	case VAR_ANY:
3913 	case VAR_VOID:
3914 	    break;
3915     }
3916 
3917     // VAR_UNKNOWN can be the result of a invalid expression, let's say it
3918     // does not equal anything, not even itself.
3919     return FALSE;
3920 }
3921 
3922 /*
3923  * Return the next (unique) copy ID.
3924  * Used for serializing nested structures.
3925  */
3926     int
3927 get_copyID(void)
3928 {
3929     current_copyID += COPYID_INC;
3930     return current_copyID;
3931 }
3932 
3933 /*
3934  * Garbage collection for lists and dictionaries.
3935  *
3936  * We use reference counts to be able to free most items right away when they
3937  * are no longer used.  But for composite items it's possible that it becomes
3938  * unused while the reference count is > 0: When there is a recursive
3939  * reference.  Example:
3940  *	:let l = [1, 2, 3]
3941  *	:let d = {9: l}
3942  *	:let l[1] = d
3943  *
3944  * Since this is quite unusual we handle this with garbage collection: every
3945  * once in a while find out which lists and dicts are not referenced from any
3946  * variable.
3947  *
3948  * Here is a good reference text about garbage collection (refers to Python
3949  * but it applies to all reference-counting mechanisms):
3950  *	http://python.ca/nas/python/gc/
3951  */
3952 
3953 /*
3954  * Do garbage collection for lists and dicts.
3955  * When "testing" is TRUE this is called from test_garbagecollect_now().
3956  * Return TRUE if some memory was freed.
3957  */
3958     int
3959 garbage_collect(int testing)
3960 {
3961     int		copyID;
3962     int		abort = FALSE;
3963     buf_T	*buf;
3964     win_T	*wp;
3965     int		did_free = FALSE;
3966     tabpage_T	*tp;
3967 
3968     if (!testing)
3969     {
3970 	// Only do this once.
3971 	want_garbage_collect = FALSE;
3972 	may_garbage_collect = FALSE;
3973 	garbage_collect_at_exit = FALSE;
3974     }
3975 
3976     // The execution stack can grow big, limit the size.
3977     if (exestack.ga_maxlen - exestack.ga_len > 500)
3978     {
3979 	size_t	new_len;
3980 	char_u	*pp;
3981 	int	n;
3982 
3983 	// Keep 150% of the current size, with a minimum of the growth size.
3984 	n = exestack.ga_len / 2;
3985 	if (n < exestack.ga_growsize)
3986 	    n = exestack.ga_growsize;
3987 
3988 	// Don't make it bigger though.
3989 	if (exestack.ga_len + n < exestack.ga_maxlen)
3990 	{
3991 	    new_len = exestack.ga_itemsize * (exestack.ga_len + n);
3992 	    pp = vim_realloc(exestack.ga_data, new_len);
3993 	    if (pp == NULL)
3994 		return FAIL;
3995 	    exestack.ga_maxlen = exestack.ga_len + n;
3996 	    exestack.ga_data = pp;
3997 	}
3998     }
3999 
4000     // We advance by two because we add one for items referenced through
4001     // previous_funccal.
4002     copyID = get_copyID();
4003 
4004     /*
4005      * 1. Go through all accessible variables and mark all lists and dicts
4006      *    with copyID.
4007      */
4008 
4009     // Don't free variables in the previous_funccal list unless they are only
4010     // referenced through previous_funccal.  This must be first, because if
4011     // the item is referenced elsewhere the funccal must not be freed.
4012     abort = abort || set_ref_in_previous_funccal(copyID);
4013 
4014     // script-local variables
4015     abort = abort || garbage_collect_scriptvars(copyID);
4016 
4017     // buffer-local variables
4018     FOR_ALL_BUFFERS(buf)
4019 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
4020 								  NULL, NULL);
4021 
4022     // window-local variables
4023     FOR_ALL_TAB_WINDOWS(tp, wp)
4024 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4025 								  NULL, NULL);
4026     if (aucmd_win != NULL)
4027 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
4028 								  NULL, NULL);
4029 #ifdef FEAT_PROP_POPUP
4030     FOR_ALL_POPUPWINS(wp)
4031 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4032 								  NULL, NULL);
4033     FOR_ALL_TABPAGES(tp)
4034 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
4035 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4036 								  NULL, NULL);
4037 #endif
4038 
4039     // tabpage-local variables
4040     FOR_ALL_TABPAGES(tp)
4041 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
4042 								  NULL, NULL);
4043     // global variables
4044     abort = abort || garbage_collect_globvars(copyID);
4045 
4046     // function-local variables
4047     abort = abort || set_ref_in_call_stack(copyID);
4048 
4049     // named functions (matters for closures)
4050     abort = abort || set_ref_in_functions(copyID);
4051 
4052     // function call arguments, if v:testing is set.
4053     abort = abort || set_ref_in_func_args(copyID);
4054 
4055     // v: vars
4056     abort = abort || garbage_collect_vimvars(copyID);
4057 
4058     // callbacks in buffers
4059     abort = abort || set_ref_in_buffers(copyID);
4060 
4061 #ifdef FEAT_LUA
4062     abort = abort || set_ref_in_lua(copyID);
4063 #endif
4064 
4065 #ifdef FEAT_PYTHON
4066     abort = abort || set_ref_in_python(copyID);
4067 #endif
4068 
4069 #ifdef FEAT_PYTHON3
4070     abort = abort || set_ref_in_python3(copyID);
4071 #endif
4072 
4073 #ifdef FEAT_JOB_CHANNEL
4074     abort = abort || set_ref_in_channel(copyID);
4075     abort = abort || set_ref_in_job(copyID);
4076 #endif
4077 #ifdef FEAT_NETBEANS_INTG
4078     abort = abort || set_ref_in_nb_channel(copyID);
4079 #endif
4080 
4081 #ifdef FEAT_TIMERS
4082     abort = abort || set_ref_in_timer(copyID);
4083 #endif
4084 
4085 #ifdef FEAT_QUICKFIX
4086     abort = abort || set_ref_in_quickfix(copyID);
4087 #endif
4088 
4089 #ifdef FEAT_TERMINAL
4090     abort = abort || set_ref_in_term(copyID);
4091 #endif
4092 
4093 #ifdef FEAT_PROP_POPUP
4094     abort = abort || set_ref_in_popups(copyID);
4095 #endif
4096 
4097     if (!abort)
4098     {
4099 	/*
4100 	 * 2. Free lists and dictionaries that are not referenced.
4101 	 */
4102 	did_free = free_unref_items(copyID);
4103 
4104 	/*
4105 	 * 3. Check if any funccal can be freed now.
4106 	 *    This may call us back recursively.
4107 	 */
4108 	free_unref_funccal(copyID, testing);
4109     }
4110     else if (p_verbose > 0)
4111     {
4112 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
4113     }
4114 
4115     return did_free;
4116 }
4117 
4118 /*
4119  * Free lists, dictionaries, channels and jobs that are no longer referenced.
4120  */
4121     static int
4122 free_unref_items(int copyID)
4123 {
4124     int		did_free = FALSE;
4125 
4126     // Let all "free" functions know that we are here.  This means no
4127     // dictionaries, lists, channels or jobs are to be freed, because we will
4128     // do that here.
4129     in_free_unref_items = TRUE;
4130 
4131     /*
4132      * PASS 1: free the contents of the items.  We don't free the items
4133      * themselves yet, so that it is possible to decrement refcount counters
4134      */
4135 
4136     // Go through the list of dicts and free items without the copyID.
4137     did_free |= dict_free_nonref(copyID);
4138 
4139     // Go through the list of lists and free items without the copyID.
4140     did_free |= list_free_nonref(copyID);
4141 
4142 #ifdef FEAT_JOB_CHANNEL
4143     // Go through the list of jobs and free items without the copyID. This
4144     // must happen before doing channels, because jobs refer to channels, but
4145     // the reference from the channel to the job isn't tracked.
4146     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4147 
4148     // Go through the list of channels and free items without the copyID.
4149     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4150 #endif
4151 
4152     /*
4153      * PASS 2: free the items themselves.
4154      */
4155     dict_free_items(copyID);
4156     list_free_items(copyID);
4157 
4158 #ifdef FEAT_JOB_CHANNEL
4159     // Go through the list of jobs and free items without the copyID. This
4160     // must happen before doing channels, because jobs refer to channels, but
4161     // the reference from the channel to the job isn't tracked.
4162     free_unused_jobs(copyID, COPYID_MASK);
4163 
4164     // Go through the list of channels and free items without the copyID.
4165     free_unused_channels(copyID, COPYID_MASK);
4166 #endif
4167 
4168     in_free_unref_items = FALSE;
4169 
4170     return did_free;
4171 }
4172 
4173 /*
4174  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4175  * "list_stack" is used to add lists to be marked.  Can be NULL.
4176  *
4177  * Returns TRUE if setting references failed somehow.
4178  */
4179     int
4180 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4181 {
4182     int		todo;
4183     int		abort = FALSE;
4184     hashitem_T	*hi;
4185     hashtab_T	*cur_ht;
4186     ht_stack_T	*ht_stack = NULL;
4187     ht_stack_T	*tempitem;
4188 
4189     cur_ht = ht;
4190     for (;;)
4191     {
4192 	if (!abort)
4193 	{
4194 	    // Mark each item in the hashtab.  If the item contains a hashtab
4195 	    // it is added to ht_stack, if it contains a list it is added to
4196 	    // list_stack.
4197 	    todo = (int)cur_ht->ht_used;
4198 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4199 		if (!HASHITEM_EMPTY(hi))
4200 		{
4201 		    --todo;
4202 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4203 						       &ht_stack, list_stack);
4204 		}
4205 	}
4206 
4207 	if (ht_stack == NULL)
4208 	    break;
4209 
4210 	// take an item from the stack
4211 	cur_ht = ht_stack->ht;
4212 	tempitem = ht_stack;
4213 	ht_stack = ht_stack->prev;
4214 	free(tempitem);
4215     }
4216 
4217     return abort;
4218 }
4219 
4220 /*
4221  * Mark a dict and its items with "copyID".
4222  * Returns TRUE if setting references failed somehow.
4223  */
4224     int
4225 set_ref_in_dict(dict_T *d, int copyID)
4226 {
4227     if (d != NULL && d->dv_copyID != copyID)
4228     {
4229 	d->dv_copyID = copyID;
4230 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4231     }
4232     return FALSE;
4233 }
4234 
4235 /*
4236  * Mark a list and its items with "copyID".
4237  * Returns TRUE if setting references failed somehow.
4238  */
4239     int
4240 set_ref_in_list(list_T *ll, int copyID)
4241 {
4242     if (ll != NULL && ll->lv_copyID != copyID)
4243     {
4244 	ll->lv_copyID = copyID;
4245 	return set_ref_in_list_items(ll, copyID, NULL);
4246     }
4247     return FALSE;
4248 }
4249 
4250 /*
4251  * Mark all lists and dicts referenced through list "l" with "copyID".
4252  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4253  *
4254  * Returns TRUE if setting references failed somehow.
4255  */
4256     int
4257 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4258 {
4259     listitem_T	 *li;
4260     int		 abort = FALSE;
4261     list_T	 *cur_l;
4262     list_stack_T *list_stack = NULL;
4263     list_stack_T *tempitem;
4264 
4265     cur_l = l;
4266     for (;;)
4267     {
4268 	if (!abort && cur_l->lv_first != &range_list_item)
4269 	    // Mark each item in the list.  If the item contains a hashtab
4270 	    // it is added to ht_stack, if it contains a list it is added to
4271 	    // list_stack.
4272 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4273 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4274 						       ht_stack, &list_stack);
4275 	if (list_stack == NULL)
4276 	    break;
4277 
4278 	// take an item from the stack
4279 	cur_l = list_stack->list;
4280 	tempitem = list_stack;
4281 	list_stack = list_stack->prev;
4282 	free(tempitem);
4283     }
4284 
4285     return abort;
4286 }
4287 
4288 /*
4289  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4290  * "list_stack" is used to add lists to be marked.  Can be NULL.
4291  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4292  *
4293  * Returns TRUE if setting references failed somehow.
4294  */
4295     int
4296 set_ref_in_item(
4297     typval_T	    *tv,
4298     int		    copyID,
4299     ht_stack_T	    **ht_stack,
4300     list_stack_T    **list_stack)
4301 {
4302     int		abort = FALSE;
4303 
4304     if (tv->v_type == VAR_DICT)
4305     {
4306 	dict_T	*dd = tv->vval.v_dict;
4307 
4308 	if (dd != NULL && dd->dv_copyID != copyID)
4309 	{
4310 	    // Didn't see this dict yet.
4311 	    dd->dv_copyID = copyID;
4312 	    if (ht_stack == NULL)
4313 	    {
4314 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4315 	    }
4316 	    else
4317 	    {
4318 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
4319 		if (newitem == NULL)
4320 		    abort = TRUE;
4321 		else
4322 		{
4323 		    newitem->ht = &dd->dv_hashtab;
4324 		    newitem->prev = *ht_stack;
4325 		    *ht_stack = newitem;
4326 		}
4327 	    }
4328 	}
4329     }
4330     else if (tv->v_type == VAR_LIST)
4331     {
4332 	list_T	*ll = tv->vval.v_list;
4333 
4334 	if (ll != NULL && ll->lv_copyID != copyID)
4335 	{
4336 	    // Didn't see this list yet.
4337 	    ll->lv_copyID = copyID;
4338 	    if (list_stack == NULL)
4339 	    {
4340 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4341 	    }
4342 	    else
4343 	    {
4344 		list_stack_T *newitem = (list_stack_T*)malloc(
4345 							sizeof(list_stack_T));
4346 		if (newitem == NULL)
4347 		    abort = TRUE;
4348 		else
4349 		{
4350 		    newitem->list = ll;
4351 		    newitem->prev = *list_stack;
4352 		    *list_stack = newitem;
4353 		}
4354 	    }
4355 	}
4356     }
4357     else if (tv->v_type == VAR_FUNC)
4358     {
4359 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4360     }
4361     else if (tv->v_type == VAR_PARTIAL)
4362     {
4363 	partial_T	*pt = tv->vval.v_partial;
4364 	int		i;
4365 
4366 	if (pt != NULL && pt->pt_copyID != copyID)
4367 	{
4368 	    // Didn't see this partial yet.
4369 	    pt->pt_copyID = copyID;
4370 
4371 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4372 
4373 	    if (pt->pt_dict != NULL)
4374 	    {
4375 		typval_T dtv;
4376 
4377 		dtv.v_type = VAR_DICT;
4378 		dtv.vval.v_dict = pt->pt_dict;
4379 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4380 	    }
4381 
4382 	    for (i = 0; i < pt->pt_argc; ++i)
4383 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4384 							ht_stack, list_stack);
4385 	    if (pt->pt_funcstack != NULL)
4386 	    {
4387 		typval_T    *stack = pt->pt_funcstack->fs_ga.ga_data;
4388 
4389 		for (i = 0; i < pt->pt_funcstack->fs_ga.ga_len; ++i)
4390 		    abort = abort || set_ref_in_item(stack + i, copyID,
4391 							 ht_stack, list_stack);
4392 	    }
4393 
4394 	}
4395     }
4396 #ifdef FEAT_JOB_CHANNEL
4397     else if (tv->v_type == VAR_JOB)
4398     {
4399 	job_T	    *job = tv->vval.v_job;
4400 	typval_T    dtv;
4401 
4402 	if (job != NULL && job->jv_copyID != copyID)
4403 	{
4404 	    job->jv_copyID = copyID;
4405 	    if (job->jv_channel != NULL)
4406 	    {
4407 		dtv.v_type = VAR_CHANNEL;
4408 		dtv.vval.v_channel = job->jv_channel;
4409 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4410 	    }
4411 	    if (job->jv_exit_cb.cb_partial != NULL)
4412 	    {
4413 		dtv.v_type = VAR_PARTIAL;
4414 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4415 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4416 	    }
4417 	}
4418     }
4419     else if (tv->v_type == VAR_CHANNEL)
4420     {
4421 	channel_T   *ch =tv->vval.v_channel;
4422 	ch_part_T   part;
4423 	typval_T    dtv;
4424 	jsonq_T	    *jq;
4425 	cbq_T	    *cq;
4426 
4427 	if (ch != NULL && ch->ch_copyID != copyID)
4428 	{
4429 	    ch->ch_copyID = copyID;
4430 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4431 	    {
4432 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4433 							     jq = jq->jq_next)
4434 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4435 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4436 							     cq = cq->cq_next)
4437 		    if (cq->cq_callback.cb_partial != NULL)
4438 		    {
4439 			dtv.v_type = VAR_PARTIAL;
4440 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4441 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4442 		    }
4443 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4444 		{
4445 		    dtv.v_type = VAR_PARTIAL;
4446 		    dtv.vval.v_partial =
4447 				      ch->ch_part[part].ch_callback.cb_partial;
4448 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4449 		}
4450 	    }
4451 	    if (ch->ch_callback.cb_partial != NULL)
4452 	    {
4453 		dtv.v_type = VAR_PARTIAL;
4454 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4455 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4456 	    }
4457 	    if (ch->ch_close_cb.cb_partial != NULL)
4458 	    {
4459 		dtv.v_type = VAR_PARTIAL;
4460 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4461 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4462 	    }
4463 	}
4464     }
4465 #endif
4466     return abort;
4467 }
4468 
4469 /*
4470  * Return a string with the string representation of a variable.
4471  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4472  * "numbuf" is used for a number.
4473  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4474  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4475  * stings as "string()", otherwise does not put quotes around strings, as
4476  * ":echo" displays values.
4477  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4478  * are replaced with "...".
4479  * May return NULL.
4480  */
4481     char_u *
4482 echo_string_core(
4483     typval_T	*tv,
4484     char_u	**tofree,
4485     char_u	*numbuf,
4486     int		copyID,
4487     int		echo_style,
4488     int		restore_copyID,
4489     int		composite_val)
4490 {
4491     static int	recurse = 0;
4492     char_u	*r = NULL;
4493 
4494     if (recurse >= DICT_MAXNEST)
4495     {
4496 	if (!did_echo_string_emsg)
4497 	{
4498 	    // Only give this message once for a recursive call to avoid
4499 	    // flooding the user with errors.  And stop iterating over lists
4500 	    // and dicts.
4501 	    did_echo_string_emsg = TRUE;
4502 	    emsg(_("E724: variable nested too deep for displaying"));
4503 	}
4504 	*tofree = NULL;
4505 	return (char_u *)"{E724}";
4506     }
4507     ++recurse;
4508 
4509     switch (tv->v_type)
4510     {
4511 	case VAR_STRING:
4512 	    if (echo_style && !composite_val)
4513 	    {
4514 		*tofree = NULL;
4515 		r = tv->vval.v_string;
4516 		if (r == NULL)
4517 		    r = (char_u *)"";
4518 	    }
4519 	    else
4520 	    {
4521 		*tofree = string_quote(tv->vval.v_string, FALSE);
4522 		r = *tofree;
4523 	    }
4524 	    break;
4525 
4526 	case VAR_FUNC:
4527 	    if (echo_style)
4528 	    {
4529 		*tofree = NULL;
4530 		r = tv->vval.v_string;
4531 	    }
4532 	    else
4533 	    {
4534 		*tofree = string_quote(tv->vval.v_string, TRUE);
4535 		r = *tofree;
4536 	    }
4537 	    break;
4538 
4539 	case VAR_PARTIAL:
4540 	    {
4541 		partial_T   *pt = tv->vval.v_partial;
4542 		char_u	    *fname = string_quote(pt == NULL ? NULL
4543 						    : partial_name(pt), FALSE);
4544 		garray_T    ga;
4545 		int	    i;
4546 		char_u	    *tf;
4547 
4548 		ga_init2(&ga, 1, 100);
4549 		ga_concat(&ga, (char_u *)"function(");
4550 		if (fname != NULL)
4551 		{
4552 		    ga_concat(&ga, fname);
4553 		    vim_free(fname);
4554 		}
4555 		if (pt != NULL && pt->pt_argc > 0)
4556 		{
4557 		    ga_concat(&ga, (char_u *)", [");
4558 		    for (i = 0; i < pt->pt_argc; ++i)
4559 		    {
4560 			if (i > 0)
4561 			    ga_concat(&ga, (char_u *)", ");
4562 			ga_concat(&ga,
4563 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
4564 			vim_free(tf);
4565 		    }
4566 		    ga_concat(&ga, (char_u *)"]");
4567 		}
4568 		if (pt != NULL && pt->pt_dict != NULL)
4569 		{
4570 		    typval_T dtv;
4571 
4572 		    ga_concat(&ga, (char_u *)", ");
4573 		    dtv.v_type = VAR_DICT;
4574 		    dtv.vval.v_dict = pt->pt_dict;
4575 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
4576 		    vim_free(tf);
4577 		}
4578 		ga_concat(&ga, (char_u *)")");
4579 
4580 		*tofree = ga.ga_data;
4581 		r = *tofree;
4582 		break;
4583 	    }
4584 
4585 	case VAR_BLOB:
4586 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
4587 	    break;
4588 
4589 	case VAR_LIST:
4590 	    if (tv->vval.v_list == NULL)
4591 	    {
4592 		// NULL list is equivalent to empty list.
4593 		*tofree = NULL;
4594 		r = (char_u *)"[]";
4595 	    }
4596 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
4597 		    && tv->vval.v_list->lv_len > 0)
4598 	    {
4599 		*tofree = NULL;
4600 		r = (char_u *)"[...]";
4601 	    }
4602 	    else
4603 	    {
4604 		int old_copyID = tv->vval.v_list->lv_copyID;
4605 
4606 		tv->vval.v_list->lv_copyID = copyID;
4607 		*tofree = list2string(tv, copyID, restore_copyID);
4608 		if (restore_copyID)
4609 		    tv->vval.v_list->lv_copyID = old_copyID;
4610 		r = *tofree;
4611 	    }
4612 	    break;
4613 
4614 	case VAR_DICT:
4615 	    if (tv->vval.v_dict == NULL)
4616 	    {
4617 		// NULL dict is equivalent to empty dict.
4618 		*tofree = NULL;
4619 		r = (char_u *)"{}";
4620 	    }
4621 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
4622 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
4623 	    {
4624 		*tofree = NULL;
4625 		r = (char_u *)"{...}";
4626 	    }
4627 	    else
4628 	    {
4629 		int old_copyID = tv->vval.v_dict->dv_copyID;
4630 
4631 		tv->vval.v_dict->dv_copyID = copyID;
4632 		*tofree = dict2string(tv, copyID, restore_copyID);
4633 		if (restore_copyID)
4634 		    tv->vval.v_dict->dv_copyID = old_copyID;
4635 		r = *tofree;
4636 	    }
4637 	    break;
4638 
4639 	case VAR_NUMBER:
4640 	case VAR_UNKNOWN:
4641 	case VAR_ANY:
4642 	case VAR_VOID:
4643 	    *tofree = NULL;
4644 	    r = tv_get_string_buf(tv, numbuf);
4645 	    break;
4646 
4647 	case VAR_JOB:
4648 	case VAR_CHANNEL:
4649 	    *tofree = NULL;
4650 	    r = tv_get_string_buf(tv, numbuf);
4651 	    if (composite_val)
4652 	    {
4653 		*tofree = string_quote(r, FALSE);
4654 		r = *tofree;
4655 	    }
4656 	    break;
4657 
4658 	case VAR_FLOAT:
4659 #ifdef FEAT_FLOAT
4660 	    *tofree = NULL;
4661 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
4662 	    r = numbuf;
4663 	    break;
4664 #endif
4665 
4666 	case VAR_BOOL:
4667 	case VAR_SPECIAL:
4668 	    *tofree = NULL;
4669 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
4670 	    break;
4671     }
4672 
4673     if (--recurse == 0)
4674 	did_echo_string_emsg = FALSE;
4675     return r;
4676 }
4677 
4678 /*
4679  * Return a string with the string representation of a variable.
4680  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4681  * "numbuf" is used for a number.
4682  * Does not put quotes around strings, as ":echo" displays values.
4683  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4684  * May return NULL.
4685  */
4686     char_u *
4687 echo_string(
4688     typval_T	*tv,
4689     char_u	**tofree,
4690     char_u	*numbuf,
4691     int		copyID)
4692 {
4693     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
4694 }
4695 
4696 /*
4697  * Return a string with the string representation of a variable.
4698  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4699  * "numbuf" is used for a number.
4700  * Puts quotes around strings, so that they can be parsed back by eval().
4701  * May return NULL.
4702  */
4703     char_u *
4704 tv2string(
4705     typval_T	*tv,
4706     char_u	**tofree,
4707     char_u	*numbuf,
4708     int		copyID)
4709 {
4710     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
4711 }
4712 
4713 /*
4714  * Return string "str" in ' quotes, doubling ' characters.
4715  * If "str" is NULL an empty string is assumed.
4716  * If "function" is TRUE make it function('string').
4717  */
4718     char_u *
4719 string_quote(char_u *str, int function)
4720 {
4721     unsigned	len;
4722     char_u	*p, *r, *s;
4723 
4724     len = (function ? 13 : 3);
4725     if (str != NULL)
4726     {
4727 	len += (unsigned)STRLEN(str);
4728 	for (p = str; *p != NUL; MB_PTR_ADV(p))
4729 	    if (*p == '\'')
4730 		++len;
4731     }
4732     s = r = alloc(len);
4733     if (r != NULL)
4734     {
4735 	if (function)
4736 	{
4737 	    STRCPY(r, "function('");
4738 	    r += 10;
4739 	}
4740 	else
4741 	    *r++ = '\'';
4742 	if (str != NULL)
4743 	    for (p = str; *p != NUL; )
4744 	    {
4745 		if (*p == '\'')
4746 		    *r++ = '\'';
4747 		MB_COPY_CHAR(p, r);
4748 	    }
4749 	*r++ = '\'';
4750 	if (function)
4751 	    *r++ = ')';
4752 	*r++ = NUL;
4753     }
4754     return s;
4755 }
4756 
4757 #if defined(FEAT_FLOAT) || defined(PROTO)
4758 /*
4759  * Convert the string "text" to a floating point number.
4760  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
4761  * this always uses a decimal point.
4762  * Returns the length of the text that was consumed.
4763  */
4764     int
4765 string2float(
4766     char_u	*text,
4767     float_T	*value)	    // result stored here
4768 {
4769     char	*s = (char *)text;
4770     float_T	f;
4771 
4772     // MS-Windows does not deal with "inf" and "nan" properly.
4773     if (STRNICMP(text, "inf", 3) == 0)
4774     {
4775 	*value = INFINITY;
4776 	return 3;
4777     }
4778     if (STRNICMP(text, "-inf", 3) == 0)
4779     {
4780 	*value = -INFINITY;
4781 	return 4;
4782     }
4783     if (STRNICMP(text, "nan", 3) == 0)
4784     {
4785 	*value = NAN;
4786 	return 3;
4787     }
4788     f = strtod(s, &s);
4789     *value = f;
4790     return (int)((char_u *)s - text);
4791 }
4792 #endif
4793 
4794 /*
4795  * Get the value of an environment variable.
4796  * "arg" is pointing to the '$'.  It is advanced to after the name.
4797  * If the environment variable was not set, silently assume it is empty.
4798  * Return FAIL if the name is invalid.
4799  */
4800     int
4801 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
4802 {
4803     char_u	*string = NULL;
4804     int		len;
4805     int		cc;
4806     char_u	*name;
4807     int		mustfree = FALSE;
4808 
4809     ++*arg;
4810     name = *arg;
4811     len = get_env_len(arg);
4812     if (evaluate)
4813     {
4814 	if (len == 0)
4815 	    return FAIL; // invalid empty name
4816 
4817 	cc = name[len];
4818 	name[len] = NUL;
4819 	// first try vim_getenv(), fast for normal environment vars
4820 	string = vim_getenv(name, &mustfree);
4821 	if (string != NULL && *string != NUL)
4822 	{
4823 	    if (!mustfree)
4824 		string = vim_strsave(string);
4825 	}
4826 	else
4827 	{
4828 	    if (mustfree)
4829 		vim_free(string);
4830 
4831 	    // next try expanding things like $VIM and ${HOME}
4832 	    string = expand_env_save(name - 1);
4833 	    if (string != NULL && *string == '$')
4834 		VIM_CLEAR(string);
4835 	}
4836 	name[len] = cc;
4837 
4838 	rettv->v_type = VAR_STRING;
4839 	rettv->vval.v_string = string;
4840     }
4841 
4842     return OK;
4843 }
4844 
4845 /*
4846  * Translate a String variable into a position.
4847  * Returns NULL when there is an error.
4848  */
4849     pos_T *
4850 var2fpos(
4851     typval_T	*varp,
4852     int		dollar_lnum,	// TRUE when $ is last line
4853     int		*fnum)		// set to fnum for '0, 'A, etc.
4854 {
4855     char_u		*name;
4856     static pos_T	pos;
4857     pos_T		*pp;
4858 
4859     // Argument can be [lnum, col, coladd].
4860     if (varp->v_type == VAR_LIST)
4861     {
4862 	list_T		*l;
4863 	int		len;
4864 	int		error = FALSE;
4865 	listitem_T	*li;
4866 
4867 	l = varp->vval.v_list;
4868 	if (l == NULL)
4869 	    return NULL;
4870 
4871 	// Get the line number
4872 	pos.lnum = list_find_nr(l, 0L, &error);
4873 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
4874 	    return NULL;	// invalid line number
4875 
4876 	// Get the column number
4877 	pos.col = list_find_nr(l, 1L, &error);
4878 	if (error)
4879 	    return NULL;
4880 	len = (long)STRLEN(ml_get(pos.lnum));
4881 
4882 	// We accept "$" for the column number: last column.
4883 	li = list_find(l, 1L);
4884 	if (li != NULL && li->li_tv.v_type == VAR_STRING
4885 		&& li->li_tv.vval.v_string != NULL
4886 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
4887 	    pos.col = len + 1;
4888 
4889 	// Accept a position up to the NUL after the line.
4890 	if (pos.col == 0 || (int)pos.col > len + 1)
4891 	    return NULL;	// invalid column number
4892 	--pos.col;
4893 
4894 	// Get the virtual offset.  Defaults to zero.
4895 	pos.coladd = list_find_nr(l, 2L, &error);
4896 	if (error)
4897 	    pos.coladd = 0;
4898 
4899 	return &pos;
4900     }
4901 
4902     name = tv_get_string_chk(varp);
4903     if (name == NULL)
4904 	return NULL;
4905     if (name[0] == '.')				// cursor
4906 	return &curwin->w_cursor;
4907     if (name[0] == 'v' && name[1] == NUL)	// Visual start
4908     {
4909 	if (VIsual_active)
4910 	    return &VIsual;
4911 	return &curwin->w_cursor;
4912     }
4913     if (name[0] == '\'')			// mark
4914     {
4915 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
4916 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
4917 	    return NULL;
4918 	return pp;
4919     }
4920 
4921     pos.coladd = 0;
4922 
4923     if (name[0] == 'w' && dollar_lnum)
4924     {
4925 	pos.col = 0;
4926 	if (name[1] == '0')		// "w0": first visible line
4927 	{
4928 	    update_topline();
4929 	    // In silent Ex mode topline is zero, but that's not a valid line
4930 	    // number; use one instead.
4931 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
4932 	    return &pos;
4933 	}
4934 	else if (name[1] == '$')	// "w$": last visible line
4935 	{
4936 	    validate_botline();
4937 	    // In silent Ex mode botline is zero, return zero then.
4938 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
4939 	    return &pos;
4940 	}
4941     }
4942     else if (name[0] == '$')		// last column or line
4943     {
4944 	if (dollar_lnum)
4945 	{
4946 	    pos.lnum = curbuf->b_ml.ml_line_count;
4947 	    pos.col = 0;
4948 	}
4949 	else
4950 	{
4951 	    pos.lnum = curwin->w_cursor.lnum;
4952 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
4953 	}
4954 	return &pos;
4955     }
4956     return NULL;
4957 }
4958 
4959 /*
4960  * Convert list in "arg" into a position and optional file number.
4961  * When "fnump" is NULL there is no file number, only 3 items.
4962  * Note that the column is passed on as-is, the caller may want to decrement
4963  * it to use 1 for the first column.
4964  * Return FAIL when conversion is not possible, doesn't check the position for
4965  * validity.
4966  */
4967     int
4968 list2fpos(
4969     typval_T	*arg,
4970     pos_T	*posp,
4971     int		*fnump,
4972     colnr_T	*curswantp)
4973 {
4974     list_T	*l = arg->vval.v_list;
4975     long	i = 0;
4976     long	n;
4977 
4978     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
4979     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
4980     if (arg->v_type != VAR_LIST
4981 	    || l == NULL
4982 	    || l->lv_len < (fnump == NULL ? 2 : 3)
4983 	    || l->lv_len > (fnump == NULL ? 4 : 5))
4984 	return FAIL;
4985 
4986     if (fnump != NULL)
4987     {
4988 	n = list_find_nr(l, i++, NULL);	// fnum
4989 	if (n < 0)
4990 	    return FAIL;
4991 	if (n == 0)
4992 	    n = curbuf->b_fnum;		// current buffer
4993 	*fnump = n;
4994     }
4995 
4996     n = list_find_nr(l, i++, NULL);	// lnum
4997     if (n < 0)
4998 	return FAIL;
4999     posp->lnum = n;
5000 
5001     n = list_find_nr(l, i++, NULL);	// col
5002     if (n < 0)
5003 	return FAIL;
5004     posp->col = n;
5005 
5006     n = list_find_nr(l, i, NULL);	// off
5007     if (n < 0)
5008 	posp->coladd = 0;
5009     else
5010 	posp->coladd = n;
5011 
5012     if (curswantp != NULL)
5013 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
5014 
5015     return OK;
5016 }
5017 
5018 /*
5019  * Get the length of an environment variable name.
5020  * Advance "arg" to the first character after the name.
5021  * Return 0 for error.
5022  */
5023     int
5024 get_env_len(char_u **arg)
5025 {
5026     char_u	*p;
5027     int		len;
5028 
5029     for (p = *arg; vim_isIDc(*p); ++p)
5030 	;
5031     if (p == *arg)	    // no name found
5032 	return 0;
5033 
5034     len = (int)(p - *arg);
5035     *arg = p;
5036     return len;
5037 }
5038 
5039 /*
5040  * Get the length of the name of a function or internal variable.
5041  * "arg" is advanced to the first non-white character after the name.
5042  * Return 0 if something is wrong.
5043  */
5044     int
5045 get_id_len(char_u **arg)
5046 {
5047     char_u	*p;
5048     int		len;
5049 
5050     // Find the end of the name.
5051     for (p = *arg; eval_isnamec(*p); ++p)
5052     {
5053 	if (*p == ':')
5054 	{
5055 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5056 	    // slice "[n:]".  Also "xx:" is not a namespace.
5057 	    len = (int)(p - *arg);
5058 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
5059 		    || len > 1)
5060 		break;
5061 	}
5062     }
5063     if (p == *arg)	    // no name found
5064 	return 0;
5065 
5066     len = (int)(p - *arg);
5067     *arg = skipwhite(p);
5068 
5069     return len;
5070 }
5071 
5072 /*
5073  * Get the length of the name of a variable or function.
5074  * Only the name is recognized, does not handle ".key" or "[idx]".
5075  * "arg" is advanced to the first non-white character after the name.
5076  * Return -1 if curly braces expansion failed.
5077  * Return 0 if something else is wrong.
5078  * If the name contains 'magic' {}'s, expand them and return the
5079  * expanded name in an allocated string via 'alias' - caller must free.
5080  */
5081     int
5082 get_name_len(
5083     char_u	**arg,
5084     char_u	**alias,
5085     int		evaluate,
5086     int		verbose)
5087 {
5088     int		len;
5089     char_u	*p;
5090     char_u	*expr_start;
5091     char_u	*expr_end;
5092 
5093     *alias = NULL;  // default to no alias
5094 
5095     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
5096 						  && (*arg)[2] == (int)KE_SNR)
5097     {
5098 	// hard coded <SNR>, already translated
5099 	*arg += 3;
5100 	return get_id_len(arg) + 3;
5101     }
5102     len = eval_fname_script(*arg);
5103     if (len > 0)
5104     {
5105 	// literal "<SID>", "s:" or "<SNR>"
5106 	*arg += len;
5107     }
5108 
5109     /*
5110      * Find the end of the name; check for {} construction.
5111      */
5112     p = find_name_end(*arg, &expr_start, &expr_end,
5113 					       len > 0 ? 0 : FNE_CHECK_START);
5114     if (expr_start != NULL)
5115     {
5116 	char_u	*temp_string;
5117 
5118 	if (!evaluate)
5119 	{
5120 	    len += (int)(p - *arg);
5121 	    *arg = skipwhite(p);
5122 	    return len;
5123 	}
5124 
5125 	/*
5126 	 * Include any <SID> etc in the expanded string:
5127 	 * Thus the -len here.
5128 	 */
5129 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
5130 	if (temp_string == NULL)
5131 	    return -1;
5132 	*alias = temp_string;
5133 	*arg = skipwhite(p);
5134 	return (int)STRLEN(temp_string);
5135     }
5136 
5137     len += get_id_len(arg);
5138     // Only give an error when there is something, otherwise it will be
5139     // reported at a higher level.
5140     if (len == 0 && verbose && **arg != NUL)
5141 	semsg(_(e_invexpr2), *arg);
5142 
5143     return len;
5144 }
5145 
5146 /*
5147  * Find the end of a variable or function name, taking care of magic braces.
5148  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
5149  * start and end of the first magic braces item.
5150  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
5151  * Return a pointer to just after the name.  Equal to "arg" if there is no
5152  * valid name.
5153  */
5154     char_u *
5155 find_name_end(
5156     char_u	*arg,
5157     char_u	**expr_start,
5158     char_u	**expr_end,
5159     int		flags)
5160 {
5161     int		mb_nest = 0;
5162     int		br_nest = 0;
5163     char_u	*p;
5164     int		len;
5165     int		vim9script = current_sctx.sc_version == SCRIPT_VERSION_VIM9;
5166 
5167     if (expr_start != NULL)
5168     {
5169 	*expr_start = NULL;
5170 	*expr_end = NULL;
5171     }
5172 
5173     // Quick check for valid starting character.
5174     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg)
5175 						&& (*arg != '{' || vim9script))
5176 	return arg;
5177 
5178     for (p = arg; *p != NUL
5179 		    && (eval_isnamec(*p)
5180 			|| (*p == '{' && !vim9script)
5181 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
5182 			|| mb_nest != 0
5183 			|| br_nest != 0); MB_PTR_ADV(p))
5184     {
5185 	if (*p == '\'')
5186 	{
5187 	    // skip over 'string' to avoid counting [ and ] inside it.
5188 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5189 		;
5190 	    if (*p == NUL)
5191 		break;
5192 	}
5193 	else if (*p == '"')
5194 	{
5195 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
5196 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5197 		if (*p == '\\' && p[1] != NUL)
5198 		    ++p;
5199 	    if (*p == NUL)
5200 		break;
5201 	}
5202 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5203 	{
5204 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5205 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
5206 	    len = (int)(p - arg);
5207 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5208 		    || (len > 1 && p[-1] != '}'))
5209 		break;
5210 	}
5211 
5212 	if (mb_nest == 0)
5213 	{
5214 	    if (*p == '[')
5215 		++br_nest;
5216 	    else if (*p == ']')
5217 		--br_nest;
5218 	}
5219 
5220 	if (br_nest == 0 && !vim9script)
5221 	{
5222 	    if (*p == '{')
5223 	    {
5224 		mb_nest++;
5225 		if (expr_start != NULL && *expr_start == NULL)
5226 		    *expr_start = p;
5227 	    }
5228 	    else if (*p == '}')
5229 	    {
5230 		mb_nest--;
5231 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5232 		    *expr_end = p;
5233 	    }
5234 	}
5235     }
5236 
5237     return p;
5238 }
5239 
5240 /*
5241  * Expands out the 'magic' {}'s in a variable/function name.
5242  * Note that this can call itself recursively, to deal with
5243  * constructs like foo{bar}{baz}{bam}
5244  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5245  *			"in_start"      ^
5246  *			"expr_start"	   ^
5247  *			"expr_end"		 ^
5248  *			"in_end"			    ^
5249  *
5250  * Returns a new allocated string, which the caller must free.
5251  * Returns NULL for failure.
5252  */
5253     static char_u *
5254 make_expanded_name(
5255     char_u	*in_start,
5256     char_u	*expr_start,
5257     char_u	*expr_end,
5258     char_u	*in_end)
5259 {
5260     char_u	c1;
5261     char_u	*retval = NULL;
5262     char_u	*temp_result;
5263     char_u	*nextcmd = NULL;
5264 
5265     if (expr_end == NULL || in_end == NULL)
5266 	return NULL;
5267     *expr_start	= NUL;
5268     *expr_end = NUL;
5269     c1 = *in_end;
5270     *in_end = NUL;
5271 
5272     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
5273     if (temp_result != NULL && nextcmd == NULL)
5274     {
5275 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5276 						   + (in_end - expr_end) + 1);
5277 	if (retval != NULL)
5278 	{
5279 	    STRCPY(retval, in_start);
5280 	    STRCAT(retval, temp_result);
5281 	    STRCAT(retval, expr_end + 1);
5282 	}
5283     }
5284     vim_free(temp_result);
5285 
5286     *in_end = c1;		// put char back for error messages
5287     *expr_start = '{';
5288     *expr_end = '}';
5289 
5290     if (retval != NULL)
5291     {
5292 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5293 	if (expr_start != NULL)
5294 	{
5295 	    // Further expansion!
5296 	    temp_result = make_expanded_name(retval, expr_start,
5297 						       expr_end, temp_result);
5298 	    vim_free(retval);
5299 	    retval = temp_result;
5300 	}
5301     }
5302 
5303     return retval;
5304 }
5305 
5306 /*
5307  * Return TRUE if character "c" can be used in a variable or function name.
5308  * Does not include '{' or '}' for magic braces.
5309  */
5310     int
5311 eval_isnamec(int c)
5312 {
5313     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
5314 }
5315 
5316 /*
5317  * Return TRUE if character "c" can be used as the first character in a
5318  * variable or function name (excluding '{' and '}').
5319  */
5320     int
5321 eval_isnamec1(int c)
5322 {
5323     return (ASCII_ISALPHA(c) || c == '_');
5324 }
5325 
5326 /*
5327  * Handle:
5328  * - expr[expr], expr[expr:expr] subscript
5329  * - ".name" lookup
5330  * - function call with Funcref variable: func(expr)
5331  * - method call: var->method()
5332  *
5333  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5334  */
5335     int
5336 handle_subscript(
5337     char_u	**arg,
5338     typval_T	*rettv,
5339     int		flags,		// do more than finding the end
5340     int		verbose,	// give error messages
5341     char_u	*start_leader,	// start of '!' and '-' prefixes
5342     char_u	**end_leaderp)  // end of '!' and '-' prefixes
5343 {
5344     int		evaluate = flags & EVAL_EVALUATE;
5345     int		ret = OK;
5346     dict_T	*selfdict = NULL;
5347 
5348     // "." is ".name" lookup when we found a dict or when evaluating and
5349     // scriptversion is at least 2, where string concatenation is "..".
5350     while (ret == OK
5351 	    && (((**arg == '['
5352 		    || (**arg == '.' && (rettv->v_type == VAR_DICT
5353 			|| (!evaluate
5354 			    && (*arg)[1] != '.'
5355 			    && current_sctx.sc_version >= 2)))
5356 		    || (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5357 					    || rettv->v_type == VAR_PARTIAL)))
5358 		&& !VIM_ISWHITE(*(*arg - 1)))
5359 	    || (**arg == '-' && (*arg)[1] == '>')))
5360     {
5361 	if (**arg == '(')
5362 	{
5363 	    ret = call_func_rettv(arg, rettv, evaluate, selfdict, NULL);
5364 
5365 	    // Stop the expression evaluation when immediately aborting on
5366 	    // error, or when an interrupt occurred or an exception was thrown
5367 	    // but not caught.
5368 	    if (aborting())
5369 	    {
5370 		if (ret == OK)
5371 		    clear_tv(rettv);
5372 		ret = FAIL;
5373 	    }
5374 	    dict_unref(selfdict);
5375 	    selfdict = NULL;
5376 	}
5377 	else if (**arg == '-')
5378 	{
5379 	    // Expression "-1.0->method()" applies the leader "-" before
5380 	    // applying ->.
5381 	    if (evaluate && *end_leaderp > start_leader)
5382 		ret = eval7_leader(rettv, start_leader, end_leaderp);
5383 	    if (ret == OK)
5384 	    {
5385 		if ((*arg)[2] == '{')
5386 		    // expr->{lambda}()
5387 		    ret = eval_lambda(arg, rettv, evaluate, verbose);
5388 		else
5389 		    // expr->name()
5390 		    ret = eval_method(arg, rettv, evaluate, verbose);
5391 	    }
5392 	}
5393 	else // **arg == '[' || **arg == '.'
5394 	{
5395 	    dict_unref(selfdict);
5396 	    if (rettv->v_type == VAR_DICT)
5397 	    {
5398 		selfdict = rettv->vval.v_dict;
5399 		if (selfdict != NULL)
5400 		    ++selfdict->dv_refcount;
5401 	    }
5402 	    else
5403 		selfdict = NULL;
5404 	    if (eval_index(arg, rettv, flags, verbose) == FAIL)
5405 	    {
5406 		clear_tv(rettv);
5407 		ret = FAIL;
5408 	    }
5409 	}
5410     }
5411 
5412     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5413     // Don't do this when "Func" is already a partial that was bound
5414     // explicitly (pt_auto is FALSE).
5415     if (selfdict != NULL
5416 	    && (rettv->v_type == VAR_FUNC
5417 		|| (rettv->v_type == VAR_PARTIAL
5418 		    && (rettv->vval.v_partial->pt_auto
5419 			|| rettv->vval.v_partial->pt_dict == NULL))))
5420 	selfdict = make_partial(selfdict, rettv);
5421 
5422     dict_unref(selfdict);
5423     return ret;
5424 }
5425 
5426 /*
5427  * Allocate memory for a variable type-value, and make it empty (0 or NULL
5428  * value).
5429  */
5430     typval_T *
5431 alloc_tv(void)
5432 {
5433     return ALLOC_CLEAR_ONE(typval_T);
5434 }
5435 
5436 /*
5437  * Allocate memory for a variable type-value, and assign a string to it.
5438  * The string "s" must have been allocated, it is consumed.
5439  * Return NULL for out of memory, the variable otherwise.
5440  */
5441     typval_T *
5442 alloc_string_tv(char_u *s)
5443 {
5444     typval_T	*rettv;
5445 
5446     rettv = alloc_tv();
5447     if (rettv != NULL)
5448     {
5449 	rettv->v_type = VAR_STRING;
5450 	rettv->vval.v_string = s;
5451     }
5452     else
5453 	vim_free(s);
5454     return rettv;
5455 }
5456 
5457 /*
5458  * Free the memory for a variable type-value.
5459  */
5460     void
5461 free_tv(typval_T *varp)
5462 {
5463     if (varp != NULL)
5464     {
5465 	switch (varp->v_type)
5466 	{
5467 	    case VAR_FUNC:
5468 		func_unref(varp->vval.v_string);
5469 		// FALLTHROUGH
5470 	    case VAR_STRING:
5471 		vim_free(varp->vval.v_string);
5472 		break;
5473 	    case VAR_PARTIAL:
5474 		partial_unref(varp->vval.v_partial);
5475 		break;
5476 	    case VAR_BLOB:
5477 		blob_unref(varp->vval.v_blob);
5478 		break;
5479 	    case VAR_LIST:
5480 		list_unref(varp->vval.v_list);
5481 		break;
5482 	    case VAR_DICT:
5483 		dict_unref(varp->vval.v_dict);
5484 		break;
5485 	    case VAR_JOB:
5486 #ifdef FEAT_JOB_CHANNEL
5487 		job_unref(varp->vval.v_job);
5488 		break;
5489 #endif
5490 	    case VAR_CHANNEL:
5491 #ifdef FEAT_JOB_CHANNEL
5492 		channel_unref(varp->vval.v_channel);
5493 		break;
5494 #endif
5495 	    case VAR_NUMBER:
5496 	    case VAR_FLOAT:
5497 	    case VAR_ANY:
5498 	    case VAR_UNKNOWN:
5499 	    case VAR_VOID:
5500 	    case VAR_BOOL:
5501 	    case VAR_SPECIAL:
5502 		break;
5503 	}
5504 	vim_free(varp);
5505     }
5506 }
5507 
5508 /*
5509  * Free the memory for a variable value and set the value to NULL or 0.
5510  */
5511     void
5512 clear_tv(typval_T *varp)
5513 {
5514     if (varp != NULL)
5515     {
5516 	switch (varp->v_type)
5517 	{
5518 	    case VAR_FUNC:
5519 		func_unref(varp->vval.v_string);
5520 		// FALLTHROUGH
5521 	    case VAR_STRING:
5522 		VIM_CLEAR(varp->vval.v_string);
5523 		break;
5524 	    case VAR_PARTIAL:
5525 		partial_unref(varp->vval.v_partial);
5526 		varp->vval.v_partial = NULL;
5527 		break;
5528 	    case VAR_BLOB:
5529 		blob_unref(varp->vval.v_blob);
5530 		varp->vval.v_blob = NULL;
5531 		break;
5532 	    case VAR_LIST:
5533 		list_unref(varp->vval.v_list);
5534 		varp->vval.v_list = NULL;
5535 		break;
5536 	    case VAR_DICT:
5537 		dict_unref(varp->vval.v_dict);
5538 		varp->vval.v_dict = NULL;
5539 		break;
5540 	    case VAR_NUMBER:
5541 	    case VAR_BOOL:
5542 	    case VAR_SPECIAL:
5543 		varp->vval.v_number = 0;
5544 		break;
5545 	    case VAR_FLOAT:
5546 #ifdef FEAT_FLOAT
5547 		varp->vval.v_float = 0.0;
5548 		break;
5549 #endif
5550 	    case VAR_JOB:
5551 #ifdef FEAT_JOB_CHANNEL
5552 		job_unref(varp->vval.v_job);
5553 		varp->vval.v_job = NULL;
5554 #endif
5555 		break;
5556 	    case VAR_CHANNEL:
5557 #ifdef FEAT_JOB_CHANNEL
5558 		channel_unref(varp->vval.v_channel);
5559 		varp->vval.v_channel = NULL;
5560 #endif
5561 	    case VAR_UNKNOWN:
5562 	    case VAR_ANY:
5563 	    case VAR_VOID:
5564 		break;
5565 	}
5566 	varp->v_lock = 0;
5567     }
5568 }
5569 
5570 /*
5571  * Set the value of a variable to NULL without freeing items.
5572  */
5573     void
5574 init_tv(typval_T *varp)
5575 {
5576     if (varp != NULL)
5577 	CLEAR_POINTER(varp);
5578 }
5579 
5580 /*
5581  * Get the number value of a variable.
5582  * If it is a String variable, uses vim_str2nr().
5583  * For incompatible types, return 0.
5584  * tv_get_number_chk() is similar to tv_get_number(), but informs the
5585  * caller of incompatible types: it sets *denote to TRUE if "denote"
5586  * is not NULL or returns -1 otherwise.
5587  */
5588     varnumber_T
5589 tv_get_number(typval_T *varp)
5590 {
5591     int		error = FALSE;
5592 
5593     return tv_get_number_chk(varp, &error);	// return 0L on error
5594 }
5595 
5596     varnumber_T
5597 tv_get_number_chk(typval_T *varp, int *denote)
5598 {
5599     varnumber_T	n = 0L;
5600 
5601     switch (varp->v_type)
5602     {
5603 	case VAR_NUMBER:
5604 	    return varp->vval.v_number;
5605 	case VAR_FLOAT:
5606 #ifdef FEAT_FLOAT
5607 	    emsg(_("E805: Using a Float as a Number"));
5608 	    break;
5609 #endif
5610 	case VAR_FUNC:
5611 	case VAR_PARTIAL:
5612 	    emsg(_("E703: Using a Funcref as a Number"));
5613 	    break;
5614 	case VAR_STRING:
5615 	    if (varp->vval.v_string != NULL)
5616 		vim_str2nr(varp->vval.v_string, NULL, NULL,
5617 					    STR2NR_ALL, &n, NULL, 0, FALSE);
5618 	    return n;
5619 	case VAR_LIST:
5620 	    emsg(_("E745: Using a List as a Number"));
5621 	    break;
5622 	case VAR_DICT:
5623 	    emsg(_("E728: Using a Dictionary as a Number"));
5624 	    break;
5625 	case VAR_BOOL:
5626 	case VAR_SPECIAL:
5627 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
5628 	case VAR_JOB:
5629 #ifdef FEAT_JOB_CHANNEL
5630 	    emsg(_("E910: Using a Job as a Number"));
5631 	    break;
5632 #endif
5633 	case VAR_CHANNEL:
5634 #ifdef FEAT_JOB_CHANNEL
5635 	    emsg(_("E913: Using a Channel as a Number"));
5636 	    break;
5637 #endif
5638 	case VAR_BLOB:
5639 	    emsg(_("E974: Using a Blob as a Number"));
5640 	    break;
5641 	case VAR_UNKNOWN:
5642 	case VAR_ANY:
5643 	case VAR_VOID:
5644 	    internal_error_no_abort("tv_get_number(UNKNOWN)");
5645 	    break;
5646     }
5647     if (denote == NULL)		// useful for values that must be unsigned
5648 	n = -1;
5649     else
5650 	*denote = TRUE;
5651     return n;
5652 }
5653 
5654 #ifdef FEAT_FLOAT
5655     float_T
5656 tv_get_float(typval_T *varp)
5657 {
5658     switch (varp->v_type)
5659     {
5660 	case VAR_NUMBER:
5661 	    return (float_T)(varp->vval.v_number);
5662 	case VAR_FLOAT:
5663 	    return varp->vval.v_float;
5664 	case VAR_FUNC:
5665 	case VAR_PARTIAL:
5666 	    emsg(_("E891: Using a Funcref as a Float"));
5667 	    break;
5668 	case VAR_STRING:
5669 	    emsg(_("E892: Using a String as a Float"));
5670 	    break;
5671 	case VAR_LIST:
5672 	    emsg(_("E893: Using a List as a Float"));
5673 	    break;
5674 	case VAR_DICT:
5675 	    emsg(_("E894: Using a Dictionary as a Float"));
5676 	    break;
5677 	case VAR_BOOL:
5678 	    emsg(_("E362: Using a boolean value as a Float"));
5679 	    break;
5680 	case VAR_SPECIAL:
5681 	    emsg(_("E907: Using a special value as a Float"));
5682 	    break;
5683 	case VAR_JOB:
5684 # ifdef FEAT_JOB_CHANNEL
5685 	    emsg(_("E911: Using a Job as a Float"));
5686 	    break;
5687 # endif
5688 	case VAR_CHANNEL:
5689 # ifdef FEAT_JOB_CHANNEL
5690 	    emsg(_("E914: Using a Channel as a Float"));
5691 	    break;
5692 # endif
5693 	case VAR_BLOB:
5694 	    emsg(_("E975: Using a Blob as a Float"));
5695 	    break;
5696 	case VAR_UNKNOWN:
5697 	case VAR_ANY:
5698 	case VAR_VOID:
5699 	    internal_error_no_abort("tv_get_float(UNKNOWN)");
5700 	    break;
5701     }
5702     return 0;
5703 }
5704 #endif
5705 
5706 /*
5707  * Get the string value of a variable.
5708  * If it is a Number variable, the number is converted into a string.
5709  * tv_get_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
5710  * tv_get_string_buf() uses a given buffer.
5711  * If the String variable has never been set, return an empty string.
5712  * Never returns NULL;
5713  * tv_get_string_chk() and tv_get_string_buf_chk() are similar, but return
5714  * NULL on error.
5715  */
5716     char_u *
5717 tv_get_string(typval_T *varp)
5718 {
5719     static char_u   mybuf[NUMBUFLEN];
5720 
5721     return tv_get_string_buf(varp, mybuf);
5722 }
5723 
5724     char_u *
5725 tv_get_string_buf(typval_T *varp, char_u *buf)
5726 {
5727     char_u	*res =  tv_get_string_buf_chk(varp, buf);
5728 
5729     return res != NULL ? res : (char_u *)"";
5730 }
5731 
5732 /*
5733  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
5734  */
5735     char_u *
5736 tv_get_string_chk(typval_T *varp)
5737 {
5738     static char_u   mybuf[NUMBUFLEN];
5739 
5740     return tv_get_string_buf_chk(varp, mybuf);
5741 }
5742 
5743     char_u *
5744 tv_get_string_buf_chk(typval_T *varp, char_u *buf)
5745 {
5746     switch (varp->v_type)
5747     {
5748 	case VAR_NUMBER:
5749 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
5750 					    (varnumber_T)varp->vval.v_number);
5751 	    return buf;
5752 	case VAR_FUNC:
5753 	case VAR_PARTIAL:
5754 	    emsg(_("E729: using Funcref as a String"));
5755 	    break;
5756 	case VAR_LIST:
5757 	    emsg(_("E730: using List as a String"));
5758 	    break;
5759 	case VAR_DICT:
5760 	    emsg(_("E731: using Dictionary as a String"));
5761 	    break;
5762 	case VAR_FLOAT:
5763 #ifdef FEAT_FLOAT
5764 	    emsg(_(e_float_as_string));
5765 	    break;
5766 #endif
5767 	case VAR_STRING:
5768 	    if (varp->vval.v_string != NULL)
5769 		return varp->vval.v_string;
5770 	    return (char_u *)"";
5771 	case VAR_BOOL:
5772 	case VAR_SPECIAL:
5773 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
5774 	    return buf;
5775         case VAR_BLOB:
5776 	    emsg(_("E976: using Blob as a String"));
5777 	    break;
5778 	case VAR_JOB:
5779 #ifdef FEAT_JOB_CHANNEL
5780 	    {
5781 		job_T *job = varp->vval.v_job;
5782 		char  *status;
5783 
5784 		if (job == NULL)
5785 		    return (char_u *)"no process";
5786 		status = job->jv_status == JOB_FAILED ? "fail"
5787 				: job->jv_status >= JOB_ENDED ? "dead"
5788 				: "run";
5789 # ifdef UNIX
5790 		vim_snprintf((char *)buf, NUMBUFLEN,
5791 			    "process %ld %s", (long)job->jv_pid, status);
5792 # elif defined(MSWIN)
5793 		vim_snprintf((char *)buf, NUMBUFLEN,
5794 			    "process %ld %s",
5795 			    (long)job->jv_proc_info.dwProcessId,
5796 			    status);
5797 # else
5798 		// fall-back
5799 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
5800 # endif
5801 		return buf;
5802 	    }
5803 #endif
5804 	    break;
5805 	case VAR_CHANNEL:
5806 #ifdef FEAT_JOB_CHANNEL
5807 	    {
5808 		channel_T *channel = varp->vval.v_channel;
5809 		char      *status = channel_status(channel, -1);
5810 
5811 		if (channel == NULL)
5812 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
5813 		else
5814 		    vim_snprintf((char *)buf, NUMBUFLEN,
5815 				     "channel %d %s", channel->ch_id, status);
5816 		return buf;
5817 	    }
5818 #endif
5819 	    break;
5820 	case VAR_UNKNOWN:
5821 	case VAR_ANY:
5822 	case VAR_VOID:
5823 	    emsg(_(e_inval_string));
5824 	    break;
5825     }
5826     return NULL;
5827 }
5828 
5829 /*
5830  * Turn a typeval into a string.  Similar to tv_get_string_buf() but uses
5831  * string() on Dict, List, etc.
5832  */
5833     static char_u *
5834 tv_stringify(typval_T *varp, char_u *buf)
5835 {
5836     if (varp->v_type == VAR_LIST
5837 	    || varp->v_type == VAR_DICT
5838 	    || varp->v_type == VAR_BLOB
5839 	    || varp->v_type == VAR_FUNC
5840 	    || varp->v_type == VAR_PARTIAL
5841 	    || varp->v_type == VAR_FLOAT)
5842     {
5843 	typval_T tmp;
5844 
5845 	f_string(varp, &tmp);
5846 	tv_get_string_buf(&tmp, buf);
5847 	clear_tv(varp);
5848 	*varp = tmp;
5849 	return tmp.vval.v_string;
5850     }
5851     return tv_get_string_buf(varp, buf);
5852 }
5853 
5854 /*
5855  * Return TRUE if typeval "tv" and its value are set to be locked (immutable).
5856  * Also give an error message, using "name" or _("name") when use_gettext is
5857  * TRUE.
5858  */
5859     static int
5860 tv_check_lock(typval_T *tv, char_u *name, int use_gettext)
5861 {
5862     int	lock = 0;
5863 
5864     switch (tv->v_type)
5865     {
5866 	case VAR_BLOB:
5867 	    if (tv->vval.v_blob != NULL)
5868 		lock = tv->vval.v_blob->bv_lock;
5869 	    break;
5870 	case VAR_LIST:
5871 	    if (tv->vval.v_list != NULL)
5872 		lock = tv->vval.v_list->lv_lock;
5873 	    break;
5874 	case VAR_DICT:
5875 	    if (tv->vval.v_dict != NULL)
5876 		lock = tv->vval.v_dict->dv_lock;
5877 	    break;
5878 	default:
5879 	    break;
5880     }
5881     return var_check_lock(tv->v_lock, name, use_gettext)
5882 		    || (lock != 0 && var_check_lock(lock, name, use_gettext));
5883 }
5884 
5885 /*
5886  * Copy the values from typval_T "from" to typval_T "to".
5887  * When needed allocates string or increases reference count.
5888  * Does not make a copy of a list, blob or dict but copies the reference!
5889  * It is OK for "from" and "to" to point to the same item.  This is used to
5890  * make a copy later.
5891  */
5892     void
5893 copy_tv(typval_T *from, typval_T *to)
5894 {
5895     to->v_type = from->v_type;
5896     to->v_lock = 0;
5897     switch (from->v_type)
5898     {
5899 	case VAR_NUMBER:
5900 	case VAR_BOOL:
5901 	case VAR_SPECIAL:
5902 	    to->vval.v_number = from->vval.v_number;
5903 	    break;
5904 	case VAR_FLOAT:
5905 #ifdef FEAT_FLOAT
5906 	    to->vval.v_float = from->vval.v_float;
5907 	    break;
5908 #endif
5909 	case VAR_JOB:
5910 #ifdef FEAT_JOB_CHANNEL
5911 	    to->vval.v_job = from->vval.v_job;
5912 	    if (to->vval.v_job != NULL)
5913 		++to->vval.v_job->jv_refcount;
5914 	    break;
5915 #endif
5916 	case VAR_CHANNEL:
5917 #ifdef FEAT_JOB_CHANNEL
5918 	    to->vval.v_channel = from->vval.v_channel;
5919 	    if (to->vval.v_channel != NULL)
5920 		++to->vval.v_channel->ch_refcount;
5921 	    break;
5922 #endif
5923 	case VAR_STRING:
5924 	case VAR_FUNC:
5925 	    if (from->vval.v_string == NULL)
5926 		to->vval.v_string = NULL;
5927 	    else
5928 	    {
5929 		to->vval.v_string = vim_strsave(from->vval.v_string);
5930 		if (from->v_type == VAR_FUNC)
5931 		    func_ref(to->vval.v_string);
5932 	    }
5933 	    break;
5934 	case VAR_PARTIAL:
5935 	    if (from->vval.v_partial == NULL)
5936 		to->vval.v_partial = NULL;
5937 	    else
5938 	    {
5939 		to->vval.v_partial = from->vval.v_partial;
5940 		++to->vval.v_partial->pt_refcount;
5941 	    }
5942 	    break;
5943 	case VAR_BLOB:
5944 	    if (from->vval.v_blob == NULL)
5945 		to->vval.v_blob = NULL;
5946 	    else
5947 	    {
5948 		to->vval.v_blob = from->vval.v_blob;
5949 		++to->vval.v_blob->bv_refcount;
5950 	    }
5951 	    break;
5952 	case VAR_LIST:
5953 	    if (from->vval.v_list == NULL)
5954 		to->vval.v_list = NULL;
5955 	    else
5956 	    {
5957 		to->vval.v_list = from->vval.v_list;
5958 		++to->vval.v_list->lv_refcount;
5959 	    }
5960 	    break;
5961 	case VAR_DICT:
5962 	    if (from->vval.v_dict == NULL)
5963 		to->vval.v_dict = NULL;
5964 	    else
5965 	    {
5966 		to->vval.v_dict = from->vval.v_dict;
5967 		++to->vval.v_dict->dv_refcount;
5968 	    }
5969 	    break;
5970 	case VAR_UNKNOWN:
5971 	case VAR_ANY:
5972 	case VAR_VOID:
5973 	    internal_error_no_abort("copy_tv(UNKNOWN)");
5974 	    break;
5975     }
5976 }
5977 
5978 /*
5979  * Make a copy of an item.
5980  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5981  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5982  * reference to an already copied list/dict can be used.
5983  * Returns FAIL or OK.
5984  */
5985     int
5986 item_copy(
5987     typval_T	*from,
5988     typval_T	*to,
5989     int		deep,
5990     int		copyID)
5991 {
5992     static int	recurse = 0;
5993     int		ret = OK;
5994 
5995     if (recurse >= DICT_MAXNEST)
5996     {
5997 	emsg(_("E698: variable nested too deep for making a copy"));
5998 	return FAIL;
5999     }
6000     ++recurse;
6001 
6002     switch (from->v_type)
6003     {
6004 	case VAR_NUMBER:
6005 	case VAR_FLOAT:
6006 	case VAR_STRING:
6007 	case VAR_FUNC:
6008 	case VAR_PARTIAL:
6009 	case VAR_BOOL:
6010 	case VAR_SPECIAL:
6011 	case VAR_JOB:
6012 	case VAR_CHANNEL:
6013 	    copy_tv(from, to);
6014 	    break;
6015 	case VAR_LIST:
6016 	    to->v_type = VAR_LIST;
6017 	    to->v_lock = 0;
6018 	    if (from->vval.v_list == NULL)
6019 		to->vval.v_list = NULL;
6020 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
6021 	    {
6022 		// use the copy made earlier
6023 		to->vval.v_list = from->vval.v_list->lv_copylist;
6024 		++to->vval.v_list->lv_refcount;
6025 	    }
6026 	    else
6027 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
6028 	    if (to->vval.v_list == NULL)
6029 		ret = FAIL;
6030 	    break;
6031 	case VAR_BLOB:
6032 	    ret = blob_copy(from->vval.v_blob, to);
6033 	    break;
6034 	case VAR_DICT:
6035 	    to->v_type = VAR_DICT;
6036 	    to->v_lock = 0;
6037 	    if (from->vval.v_dict == NULL)
6038 		to->vval.v_dict = NULL;
6039 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
6040 	    {
6041 		// use the copy made earlier
6042 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
6043 		++to->vval.v_dict->dv_refcount;
6044 	    }
6045 	    else
6046 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
6047 	    if (to->vval.v_dict == NULL)
6048 		ret = FAIL;
6049 	    break;
6050 	case VAR_UNKNOWN:
6051 	case VAR_ANY:
6052 	case VAR_VOID:
6053 	    internal_error_no_abort("item_copy(UNKNOWN)");
6054 	    ret = FAIL;
6055     }
6056     --recurse;
6057     return ret;
6058 }
6059 
6060     void
6061 echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr)
6062 {
6063     char_u	*tofree;
6064     char_u	numbuf[NUMBUFLEN];
6065     char_u	*p = echo_string(rettv, &tofree, numbuf, get_copyID());
6066 
6067     if (*atstart)
6068     {
6069 	*atstart = FALSE;
6070 	// Call msg_start() after eval1(), evaluating the expression
6071 	// may cause a message to appear.
6072 	if (with_space)
6073 	{
6074 	    // Mark the saved text as finishing the line, so that what
6075 	    // follows is displayed on a new line when scrolling back
6076 	    // at the more prompt.
6077 	    msg_sb_eol();
6078 	    msg_start();
6079 	}
6080     }
6081     else if (with_space)
6082 	msg_puts_attr(" ", echo_attr);
6083 
6084     if (p != NULL)
6085 	for ( ; *p != NUL && !got_int; ++p)
6086 	{
6087 	    if (*p == '\n' || *p == '\r' || *p == TAB)
6088 	    {
6089 		if (*p != TAB && *needclr)
6090 		{
6091 		    // remove any text still there from the command
6092 		    msg_clr_eos();
6093 		    *needclr = FALSE;
6094 		}
6095 		msg_putchar_attr(*p, echo_attr);
6096 	    }
6097 	    else
6098 	    {
6099 		if (has_mbyte)
6100 		{
6101 		    int i = (*mb_ptr2len)(p);
6102 
6103 		    (void)msg_outtrans_len_attr(p, i, echo_attr);
6104 		    p += i - 1;
6105 		}
6106 		else
6107 		    (void)msg_outtrans_len_attr(p, 1, echo_attr);
6108 	    }
6109 	}
6110     vim_free(tofree);
6111 }
6112 
6113 /*
6114  * ":echo expr1 ..."	print each argument separated with a space, add a
6115  *			newline at the end.
6116  * ":echon expr1 ..."	print each argument plain.
6117  */
6118     void
6119 ex_echo(exarg_T *eap)
6120 {
6121     char_u	*arg = eap->arg;
6122     typval_T	rettv;
6123     char_u	*p;
6124     int		needclr = TRUE;
6125     int		atstart = TRUE;
6126     int		did_emsg_before = did_emsg;
6127     int		called_emsg_before = called_emsg;
6128 
6129     if (eap->skip)
6130 	++emsg_skip;
6131     while ((!ends_excmd2(eap->cmd, arg) || *arg == '"') && !got_int)
6132     {
6133 	// If eval1() causes an error message the text from the command may
6134 	// still need to be cleared. E.g., "echo 22,44".
6135 	need_clr_eos = needclr;
6136 
6137 	p = arg;
6138 	if (eval1(&arg, &rettv, eap->skip ? 0 : EVAL_EVALUATE) == FAIL)
6139 	{
6140 	    /*
6141 	     * Report the invalid expression unless the expression evaluation
6142 	     * has been cancelled due to an aborting error, an interrupt, or an
6143 	     * exception.
6144 	     */
6145 	    if (!aborting() && did_emsg == did_emsg_before
6146 					  && called_emsg == called_emsg_before)
6147 		semsg(_(e_invexpr2), p);
6148 	    need_clr_eos = FALSE;
6149 	    break;
6150 	}
6151 	need_clr_eos = FALSE;
6152 
6153 	if (!eap->skip)
6154 	    echo_one(&rettv, eap->cmdidx == CMD_echo, &atstart, &needclr);
6155 
6156 	clear_tv(&rettv);
6157 	arg = skipwhite(arg);
6158     }
6159     eap->nextcmd = check_nextcmd(arg);
6160 
6161     if (eap->skip)
6162 	--emsg_skip;
6163     else
6164     {
6165 	// remove text that may still be there from the command
6166 	if (needclr)
6167 	    msg_clr_eos();
6168 	if (eap->cmdidx == CMD_echo)
6169 	    msg_end();
6170     }
6171 }
6172 
6173 /*
6174  * ":echohl {name}".
6175  */
6176     void
6177 ex_echohl(exarg_T *eap)
6178 {
6179     echo_attr = syn_name2attr(eap->arg);
6180 }
6181 
6182 /*
6183  * Returns the :echo attribute
6184  */
6185     int
6186 get_echo_attr(void)
6187 {
6188     return echo_attr;
6189 }
6190 
6191 /*
6192  * ":execute expr1 ..."	execute the result of an expression.
6193  * ":echomsg expr1 ..."	Print a message
6194  * ":echoerr expr1 ..."	Print an error
6195  * Each gets spaces around each argument and a newline at the end for
6196  * echo commands
6197  */
6198     void
6199 ex_execute(exarg_T *eap)
6200 {
6201     char_u	*arg = eap->arg;
6202     typval_T	rettv;
6203     int		ret = OK;
6204     char_u	*p;
6205     garray_T	ga;
6206     int		len;
6207 
6208     ga_init2(&ga, 1, 80);
6209 
6210     if (eap->skip)
6211 	++emsg_skip;
6212     while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
6213     {
6214 	ret = eval1_emsg(&arg, &rettv, !eap->skip);
6215 	if (ret == FAIL)
6216 	    break;
6217 
6218 	if (!eap->skip)
6219 	{
6220 	    char_u   buf[NUMBUFLEN];
6221 
6222 	    if (eap->cmdidx == CMD_execute)
6223 	    {
6224 		if (rettv.v_type == VAR_CHANNEL || rettv.v_type == VAR_JOB)
6225 		{
6226 		    emsg(_(e_inval_string));
6227 		    p = NULL;
6228 		}
6229 		else
6230 		    p = tv_get_string_buf(&rettv, buf);
6231 	    }
6232 	    else
6233 		p = tv_stringify(&rettv, buf);
6234 	    if (p == NULL)
6235 	    {
6236 		clear_tv(&rettv);
6237 		ret = FAIL;
6238 		break;
6239 	    }
6240 	    len = (int)STRLEN(p);
6241 	    if (ga_grow(&ga, len + 2) == FAIL)
6242 	    {
6243 		clear_tv(&rettv);
6244 		ret = FAIL;
6245 		break;
6246 	    }
6247 	    if (ga.ga_len)
6248 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
6249 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
6250 	    ga.ga_len += len;
6251 	}
6252 
6253 	clear_tv(&rettv);
6254 	arg = skipwhite(arg);
6255     }
6256 
6257     if (ret != FAIL && ga.ga_data != NULL)
6258     {
6259 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
6260 	{
6261 	    // Mark the already saved text as finishing the line, so that what
6262 	    // follows is displayed on a new line when scrolling back at the
6263 	    // more prompt.
6264 	    msg_sb_eol();
6265 	}
6266 
6267 	if (eap->cmdidx == CMD_echomsg)
6268 	{
6269 	    msg_attr(ga.ga_data, echo_attr);
6270 	    out_flush();
6271 	}
6272 	else if (eap->cmdidx == CMD_echoerr)
6273 	{
6274 	    int		save_did_emsg = did_emsg;
6275 
6276 	    // We don't want to abort following commands, restore did_emsg.
6277 	    emsg(ga.ga_data);
6278 	    if (!force_abort)
6279 		did_emsg = save_did_emsg;
6280 	}
6281 	else if (eap->cmdidx == CMD_execute)
6282 	    do_cmdline((char_u *)ga.ga_data,
6283 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
6284     }
6285 
6286     ga_clear(&ga);
6287 
6288     if (eap->skip)
6289 	--emsg_skip;
6290 
6291     eap->nextcmd = check_nextcmd(arg);
6292 }
6293 
6294 /*
6295  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
6296  * "arg" points to the "&" or '+' when called, to "option" when returning.
6297  * Returns NULL when no option name found.  Otherwise pointer to the char
6298  * after the option name.
6299  */
6300     char_u *
6301 find_option_end(char_u **arg, int *opt_flags)
6302 {
6303     char_u	*p = *arg;
6304 
6305     ++p;
6306     if (*p == 'g' && p[1] == ':')
6307     {
6308 	*opt_flags = OPT_GLOBAL;
6309 	p += 2;
6310     }
6311     else if (*p == 'l' && p[1] == ':')
6312     {
6313 	*opt_flags = OPT_LOCAL;
6314 	p += 2;
6315     }
6316     else
6317 	*opt_flags = 0;
6318 
6319     if (!ASCII_ISALPHA(*p))
6320 	return NULL;
6321     *arg = p;
6322 
6323     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
6324 	p += 4;	    // termcap option
6325     else
6326 	while (ASCII_ISALPHA(*p))
6327 	    ++p;
6328     return p;
6329 }
6330 
6331 /*
6332  * Display script name where an item was last set.
6333  * Should only be invoked when 'verbose' is non-zero.
6334  */
6335     void
6336 last_set_msg(sctx_T script_ctx)
6337 {
6338     char_u *p;
6339 
6340     if (script_ctx.sc_sid != 0)
6341     {
6342 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
6343 	if (p != NULL)
6344 	{
6345 	    verbose_enter();
6346 	    msg_puts(_("\n\tLast set from "));
6347 	    msg_puts((char *)p);
6348 	    if (script_ctx.sc_lnum > 0)
6349 	    {
6350 		msg_puts(_(line_msg));
6351 		msg_outnum((long)script_ctx.sc_lnum);
6352 	    }
6353 	    verbose_leave();
6354 	    vim_free(p);
6355 	}
6356     }
6357 }
6358 
6359 /*
6360  * Compare "typ1" and "typ2".  Put the result in "typ1".
6361  */
6362     int
6363 typval_compare(
6364     typval_T	*typ1,   // first operand
6365     typval_T	*typ2,   // second operand
6366     exptype_T	type,    // operator
6367     int		ic)      // ignore case
6368 {
6369     int		i;
6370     varnumber_T	n1, n2;
6371     char_u	*s1, *s2;
6372     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
6373     int		type_is = type == EXPR_IS || type == EXPR_ISNOT;
6374 
6375     if (type_is && typ1->v_type != typ2->v_type)
6376     {
6377 	// For "is" a different type always means FALSE, for "notis"
6378 	// it means TRUE.
6379 	n1 = (type == EXPR_ISNOT);
6380     }
6381     else if (typ1->v_type == VAR_BLOB || typ2->v_type == VAR_BLOB)
6382     {
6383 	if (type_is)
6384 	{
6385 	    n1 = (typ1->v_type == typ2->v_type
6386 			    && typ1->vval.v_blob == typ2->vval.v_blob);
6387 	    if (type == EXPR_ISNOT)
6388 		n1 = !n1;
6389 	}
6390 	else if (typ1->v_type != typ2->v_type
6391 		|| (type != EXPR_EQUAL && type != EXPR_NEQUAL))
6392 	{
6393 	    if (typ1->v_type != typ2->v_type)
6394 		emsg(_("E977: Can only compare Blob with Blob"));
6395 	    else
6396 		emsg(_(e_invalblob));
6397 	    clear_tv(typ1);
6398 	    return FAIL;
6399 	}
6400 	else
6401 	{
6402 	    // Compare two Blobs for being equal or unequal.
6403 	    n1 = blob_equal(typ1->vval.v_blob, typ2->vval.v_blob);
6404 	    if (type == EXPR_NEQUAL)
6405 		n1 = !n1;
6406 	}
6407     }
6408     else if (typ1->v_type == VAR_LIST || typ2->v_type == VAR_LIST)
6409     {
6410 	if (type_is)
6411 	{
6412 	    n1 = (typ1->v_type == typ2->v_type
6413 			    && typ1->vval.v_list == typ2->vval.v_list);
6414 	    if (type == EXPR_ISNOT)
6415 		n1 = !n1;
6416 	}
6417 	else if (typ1->v_type != typ2->v_type
6418 		|| (type != EXPR_EQUAL && type != EXPR_NEQUAL))
6419 	{
6420 	    if (typ1->v_type != typ2->v_type)
6421 		emsg(_("E691: Can only compare List with List"));
6422 	    else
6423 		emsg(_("E692: Invalid operation for List"));
6424 	    clear_tv(typ1);
6425 	    return FAIL;
6426 	}
6427 	else
6428 	{
6429 	    // Compare two Lists for being equal or unequal.
6430 	    n1 = list_equal(typ1->vval.v_list, typ2->vval.v_list,
6431 							    ic, FALSE);
6432 	    if (type == EXPR_NEQUAL)
6433 		n1 = !n1;
6434 	}
6435     }
6436 
6437     else if (typ1->v_type == VAR_DICT || typ2->v_type == VAR_DICT)
6438     {
6439 	if (type_is)
6440 	{
6441 	    n1 = (typ1->v_type == typ2->v_type
6442 			    && typ1->vval.v_dict == typ2->vval.v_dict);
6443 	    if (type == EXPR_ISNOT)
6444 		n1 = !n1;
6445 	}
6446 	else if (typ1->v_type != typ2->v_type
6447 		|| (type != EXPR_EQUAL && type != EXPR_NEQUAL))
6448 	{
6449 	    if (typ1->v_type != typ2->v_type)
6450 		emsg(_("E735: Can only compare Dictionary with Dictionary"));
6451 	    else
6452 		emsg(_("E736: Invalid operation for Dictionary"));
6453 	    clear_tv(typ1);
6454 	    return FAIL;
6455 	}
6456 	else
6457 	{
6458 	    // Compare two Dictionaries for being equal or unequal.
6459 	    n1 = dict_equal(typ1->vval.v_dict, typ2->vval.v_dict,
6460 							    ic, FALSE);
6461 	    if (type == EXPR_NEQUAL)
6462 		n1 = !n1;
6463 	}
6464     }
6465 
6466     else if (typ1->v_type == VAR_FUNC || typ2->v_type == VAR_FUNC
6467 	|| typ1->v_type == VAR_PARTIAL || typ2->v_type == VAR_PARTIAL)
6468     {
6469 	if (type != EXPR_EQUAL && type != EXPR_NEQUAL
6470 		&& type != EXPR_IS && type != EXPR_ISNOT)
6471 	{
6472 	    emsg(_("E694: Invalid operation for Funcrefs"));
6473 	    clear_tv(typ1);
6474 	    return FAIL;
6475 	}
6476 	if ((typ1->v_type == VAR_PARTIAL
6477 					&& typ1->vval.v_partial == NULL)
6478 		|| (typ2->v_type == VAR_PARTIAL
6479 					&& typ2->vval.v_partial == NULL))
6480 	    // When both partials are NULL, then they are equal.
6481 	    // Otherwise they are not equal.
6482 	    n1 = (typ1->vval.v_partial == typ2->vval.v_partial);
6483 	else if (type_is)
6484 	{
6485 	    if (typ1->v_type == VAR_FUNC && typ2->v_type == VAR_FUNC)
6486 		// strings are considered the same if their value is
6487 		// the same
6488 		n1 = tv_equal(typ1, typ2, ic, FALSE);
6489 	    else if (typ1->v_type == VAR_PARTIAL
6490 					&& typ2->v_type == VAR_PARTIAL)
6491 		n1 = (typ1->vval.v_partial == typ2->vval.v_partial);
6492 	    else
6493 		n1 = FALSE;
6494 	}
6495 	else
6496 	    n1 = tv_equal(typ1, typ2, ic, FALSE);
6497 	if (type == EXPR_NEQUAL || type == EXPR_ISNOT)
6498 	    n1 = !n1;
6499     }
6500 
6501 #ifdef FEAT_FLOAT
6502     /*
6503 	* If one of the two variables is a float, compare as a float.
6504 	* When using "=~" or "!~", always compare as string.
6505 	*/
6506     else if ((typ1->v_type == VAR_FLOAT || typ2->v_type == VAR_FLOAT)
6507 	    && type != EXPR_MATCH && type != EXPR_NOMATCH)
6508     {
6509 	float_T f1, f2;
6510 
6511 	f1 = tv_get_float(typ1);
6512 	f2 = tv_get_float(typ2);
6513 	n1 = FALSE;
6514 	switch (type)
6515 	{
6516 	    case EXPR_IS:
6517 	    case EXPR_EQUAL:    n1 = (f1 == f2); break;
6518 	    case EXPR_ISNOT:
6519 	    case EXPR_NEQUAL:   n1 = (f1 != f2); break;
6520 	    case EXPR_GREATER:  n1 = (f1 > f2); break;
6521 	    case EXPR_GEQUAL:   n1 = (f1 >= f2); break;
6522 	    case EXPR_SMALLER:  n1 = (f1 < f2); break;
6523 	    case EXPR_SEQUAL:   n1 = (f1 <= f2); break;
6524 	    case EXPR_UNKNOWN:
6525 	    case EXPR_MATCH:
6526 	    default:  break;  // avoid gcc warning
6527 	}
6528     }
6529 #endif
6530 
6531     /*
6532      * If one of the two variables is a number, compare as a number.
6533      * When using "=~" or "!~", always compare as string.
6534      */
6535     else if ((typ1->v_type == VAR_NUMBER || typ2->v_type == VAR_NUMBER)
6536 	    && type != EXPR_MATCH && type != EXPR_NOMATCH)
6537     {
6538 	n1 = tv_get_number(typ1);
6539 	n2 = tv_get_number(typ2);
6540 	switch (type)
6541 	{
6542 	    case EXPR_IS:
6543 	    case EXPR_EQUAL:    n1 = (n1 == n2); break;
6544 	    case EXPR_ISNOT:
6545 	    case EXPR_NEQUAL:   n1 = (n1 != n2); break;
6546 	    case EXPR_GREATER:  n1 = (n1 > n2); break;
6547 	    case EXPR_GEQUAL:   n1 = (n1 >= n2); break;
6548 	    case EXPR_SMALLER:  n1 = (n1 < n2); break;
6549 	    case EXPR_SEQUAL:   n1 = (n1 <= n2); break;
6550 	    case EXPR_UNKNOWN:
6551 	    case EXPR_MATCH:
6552 	    default:  break;  // avoid gcc warning
6553 	}
6554     }
6555     else
6556     {
6557 	s1 = tv_get_string_buf(typ1, buf1);
6558 	s2 = tv_get_string_buf(typ2, buf2);
6559 	if (type != EXPR_MATCH && type != EXPR_NOMATCH)
6560 	    i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
6561 	else
6562 	    i = 0;
6563 	n1 = FALSE;
6564 	switch (type)
6565 	{
6566 	    case EXPR_IS:
6567 	    case EXPR_EQUAL:    n1 = (i == 0); break;
6568 	    case EXPR_ISNOT:
6569 	    case EXPR_NEQUAL:   n1 = (i != 0); break;
6570 	    case EXPR_GREATER:  n1 = (i > 0); break;
6571 	    case EXPR_GEQUAL:   n1 = (i >= 0); break;
6572 	    case EXPR_SMALLER:  n1 = (i < 0); break;
6573 	    case EXPR_SEQUAL:   n1 = (i <= 0); break;
6574 
6575 	    case EXPR_MATCH:
6576 	    case EXPR_NOMATCH:
6577 		    n1 = pattern_match(s2, s1, ic);
6578 		    if (type == EXPR_NOMATCH)
6579 			n1 = !n1;
6580 		    break;
6581 
6582 	    default:  break;  // avoid gcc warning
6583 	}
6584     }
6585     clear_tv(typ1);
6586     typ1->v_type = VAR_NUMBER;
6587     typ1->vval.v_number = n1;
6588 
6589     return OK;
6590 }
6591 
6592     char_u *
6593 typval_tostring(typval_T *arg)
6594 {
6595     char_u	*tofree;
6596     char_u	numbuf[NUMBUFLEN];
6597     char_u	*ret = NULL;
6598 
6599     if (arg == NULL)
6600 	return vim_strsave((char_u *)"(does not exist)");
6601     ret = tv2string(arg, &tofree, numbuf, 0);
6602     // Make a copy if we have a value but it's not in allocated memory.
6603     if (ret != NULL && tofree == NULL)
6604 	ret = vim_strsave(ret);
6605     return ret;
6606 }
6607 
6608 #endif // FEAT_EVAL
6609 
6610 /*
6611  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
6612  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
6613  * "flags" can be "g" to do a global substitute.
6614  * Returns an allocated string, NULL for error.
6615  */
6616     char_u *
6617 do_string_sub(
6618     char_u	*str,
6619     char_u	*pat,
6620     char_u	*sub,
6621     typval_T	*expr,
6622     char_u	*flags)
6623 {
6624     int		sublen;
6625     regmatch_T	regmatch;
6626     int		i;
6627     int		do_all;
6628     char_u	*tail;
6629     char_u	*end;
6630     garray_T	ga;
6631     char_u	*ret;
6632     char_u	*save_cpo;
6633     char_u	*zero_width = NULL;
6634 
6635     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
6636     save_cpo = p_cpo;
6637     p_cpo = empty_option;
6638 
6639     ga_init2(&ga, 1, 200);
6640 
6641     do_all = (flags[0] == 'g');
6642 
6643     regmatch.rm_ic = p_ic;
6644     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
6645     if (regmatch.regprog != NULL)
6646     {
6647 	tail = str;
6648 	end = str + STRLEN(str);
6649 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
6650 	{
6651 	    // Skip empty match except for first match.
6652 	    if (regmatch.startp[0] == regmatch.endp[0])
6653 	    {
6654 		if (zero_width == regmatch.startp[0])
6655 		{
6656 		    // avoid getting stuck on a match with an empty string
6657 		    i = mb_ptr2len(tail);
6658 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
6659 								   (size_t)i);
6660 		    ga.ga_len += i;
6661 		    tail += i;
6662 		    continue;
6663 		}
6664 		zero_width = regmatch.startp[0];
6665 	    }
6666 
6667 	    /*
6668 	     * Get some space for a temporary buffer to do the substitution
6669 	     * into.  It will contain:
6670 	     * - The text up to where the match is.
6671 	     * - The substituted text.
6672 	     * - The text after the match.
6673 	     */
6674 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
6675 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
6676 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
6677 	    {
6678 		ga_clear(&ga);
6679 		break;
6680 	    }
6681 
6682 	    // copy the text up to where the match is
6683 	    i = (int)(regmatch.startp[0] - tail);
6684 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
6685 	    // add the substituted text
6686 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
6687 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
6688 	    ga.ga_len += i + sublen - 1;
6689 	    tail = regmatch.endp[0];
6690 	    if (*tail == NUL)
6691 		break;
6692 	    if (!do_all)
6693 		break;
6694 	}
6695 
6696 	if (ga.ga_data != NULL)
6697 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
6698 
6699 	vim_regfree(regmatch.regprog);
6700     }
6701 
6702     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
6703     ga_clear(&ga);
6704     if (p_cpo == empty_option)
6705 	p_cpo = save_cpo;
6706     else
6707 	// Darn, evaluating {sub} expression or {expr} changed the value.
6708 	free_string_option(save_cpo);
6709 
6710     return ret;
6711 }
6712