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