xref: /vim-8.2.3635/src/eval.c (revision 5be4ceec)
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_missbrac = N_("E111: Missing ']'");
24 static char *e_dictrange = N_("E719: Cannot use [:] with a Dictionary");
25 #ifdef FEAT_FLOAT
26 static char *e_float_as_string = N_("E806: using Float as a String");
27 #endif
28 static char *e_nowhitespace = N_("E274: No white space allowed before parenthesis");
29 
30 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
31 
32 /*
33  * When recursively copying lists and dicts we need to remember which ones we
34  * have done to avoid endless recursiveness.  This unique ID is used for that.
35  * The last bit is used for previous_funccal, ignored when comparing.
36  */
37 static int current_copyID = 0;
38 
39 static int echo_attr = 0;   /* attributes used for ":echo" */
40 
41 /*
42  * Info used by a ":for" loop.
43  */
44 typedef struct
45 {
46     int		fi_semicolon;	/* TRUE if ending in '; var]' */
47     int		fi_varcount;	/* nr of variables in the list */
48     listwatch_T	fi_lw;		/* keep an eye on the item used. */
49     list_T	*fi_list;	/* list being used */
50     int		fi_bi;		/* index of blob */
51     blob_T	*fi_blob;	/* blob being used */
52 } forinfo_T;
53 
54 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
55 static int eval2(char_u **arg, typval_T *rettv, int evaluate);
56 static int eval3(char_u **arg, typval_T *rettv, int evaluate);
57 static int eval4(char_u **arg, typval_T *rettv, int evaluate);
58 static int eval5(char_u **arg, typval_T *rettv, int evaluate);
59 static int eval6(char_u **arg, typval_T *rettv, int evaluate, int want_string);
60 static int eval7(char_u **arg, typval_T *rettv, int evaluate, int want_string);
61 static int eval7_leader(typval_T *rettv, char_u *start_leader, char_u **end_leaderp);
62 
63 static int get_string_tv(char_u **arg, typval_T *rettv, int evaluate);
64 static int get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate);
65 static int free_unref_items(int copyID);
66 static int get_env_tv(char_u **arg, typval_T *rettv, int evaluate);
67 static char_u *make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
68 static int tv_check_lock(typval_T *tv, char_u *name, int use_gettext);
69 
70 /*
71  * Return "n1" divided by "n2", taking care of dividing by zero.
72  */
73 	varnumber_T
74 num_divide(varnumber_T n1, varnumber_T n2)
75 {
76     varnumber_T	result;
77 
78     if (n2 == 0)	// give an error message?
79     {
80 	if (n1 == 0)
81 	    result = VARNUM_MIN; // similar to NaN
82 	else if (n1 < 0)
83 	    result = -VARNUM_MAX;
84 	else
85 	    result = VARNUM_MAX;
86     }
87     else
88 	result = n1 / n2;
89 
90     return result;
91 }
92 
93 /*
94  * Return "n1" modulus "n2", taking care of dividing by zero.
95  */
96 	varnumber_T
97 num_modulus(varnumber_T n1, varnumber_T n2)
98 {
99     // Give an error when n2 is 0?
100     return (n2 == 0) ? 0 : (n1 % n2);
101 }
102 
103 #if defined(EBCDIC) || defined(PROTO)
104 /*
105  * Compare struct fst by function name.
106  */
107     static int
108 compare_func_name(const void *s1, const void *s2)
109 {
110     struct fst *p1 = (struct fst *)s1;
111     struct fst *p2 = (struct fst *)s2;
112 
113     return STRCMP(p1->f_name, p2->f_name);
114 }
115 
116 /*
117  * Sort the function table by function name.
118  * The sorting of the table above is ASCII dependent.
119  * On machines using EBCDIC we have to sort it.
120  */
121     static void
122 sortFunctions(void)
123 {
124     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
125 
126     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
127 }
128 #endif
129 
130 /*
131  * Initialize the global and v: variables.
132  */
133     void
134 eval_init(void)
135 {
136     evalvars_init();
137     func_init();
138 
139 #ifdef EBCDIC
140     /*
141      * Sort the function table, to enable binary search.
142      */
143     sortFunctions();
144 #endif
145 }
146 
147 #if defined(EXITFREE) || defined(PROTO)
148     void
149 eval_clear(void)
150 {
151     evalvars_clear();
152 
153     free_scriptnames();
154     free_locales();
155 
156     // autoloaded script names
157     free_autoload_scriptnames();
158 
159     // unreferenced lists and dicts
160     (void)garbage_collect(FALSE);
161 
162     // functions not garbage collected
163     free_all_functions();
164 }
165 #endif
166 
167 /*
168  * Top level evaluation function, returning a boolean.
169  * Sets "error" to TRUE if there was an error.
170  * Return TRUE or FALSE.
171  */
172     int
173 eval_to_bool(
174     char_u	*arg,
175     int		*error,
176     char_u	**nextcmd,
177     int		skip)	    /* only parse, don't execute */
178 {
179     typval_T	tv;
180     varnumber_T	retval = FALSE;
181 
182     if (skip)
183 	++emsg_skip;
184     if (eval0(arg, &tv, nextcmd, !skip) == FAIL)
185 	*error = TRUE;
186     else
187     {
188 	*error = FALSE;
189 	if (!skip)
190 	{
191 	    retval = (tv_get_number_chk(&tv, error) != 0);
192 	    clear_tv(&tv);
193 	}
194     }
195     if (skip)
196 	--emsg_skip;
197 
198     return (int)retval;
199 }
200 
201 /*
202  * Call eval1() and give an error message if not done at a lower level.
203  */
204     static int
205 eval1_emsg(char_u **arg, typval_T *rettv, int evaluate)
206 {
207     char_u	*start = *arg;
208     int		ret;
209     int		did_emsg_before = did_emsg;
210     int		called_emsg_before = called_emsg;
211 
212     ret = eval1(arg, rettv, evaluate);
213     if (ret == FAIL)
214     {
215 	// Report the invalid expression unless the expression evaluation has
216 	// been cancelled due to an aborting error, an interrupt, or an
217 	// exception, or we already gave a more specific error.
218 	// Also check called_emsg for when using assert_fails().
219 	if (!aborting() && did_emsg == did_emsg_before
220 					  && called_emsg == called_emsg_before)
221 	    semsg(_(e_invexpr2), start);
222     }
223     return ret;
224 }
225 
226     int
227 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
228 {
229     char_u	*s;
230     char_u	buf[NUMBUFLEN];
231     funcexe_T	funcexe;
232 
233     if (expr->v_type == VAR_FUNC)
234     {
235 	s = expr->vval.v_string;
236 	if (s == NULL || *s == NUL)
237 	    return FAIL;
238 	vim_memset(&funcexe, 0, sizeof(funcexe));
239 	funcexe.evaluate = TRUE;
240 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
241 	    return FAIL;
242     }
243     else if (expr->v_type == VAR_PARTIAL)
244     {
245 	partial_T   *partial = expr->vval.v_partial;
246 
247 	s = partial_name(partial);
248 	if (s == NULL || *s == NUL)
249 	    return FAIL;
250 	vim_memset(&funcexe, 0, sizeof(funcexe));
251 	funcexe.evaluate = TRUE;
252 	funcexe.partial = partial;
253 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
254 	    return FAIL;
255     }
256     else
257     {
258 	s = tv_get_string_buf_chk(expr, buf);
259 	if (s == NULL)
260 	    return FAIL;
261 	s = skipwhite(s);
262 	if (eval1_emsg(&s, rettv, TRUE) == FAIL)
263 	    return FAIL;
264 	if (*s != NUL)  /* check for trailing chars after expr */
265 	{
266 	    clear_tv(rettv);
267 	    semsg(_(e_invexpr2), s);
268 	    return FAIL;
269 	}
270     }
271     return OK;
272 }
273 
274 /*
275  * Like eval_to_bool() but using a typval_T instead of a string.
276  * Works for string, funcref and partial.
277  */
278     int
279 eval_expr_to_bool(typval_T *expr, int *error)
280 {
281     typval_T	rettv;
282     int		res;
283 
284     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
285     {
286 	*error = TRUE;
287 	return FALSE;
288     }
289     res = (tv_get_number_chk(&rettv, error) != 0);
290     clear_tv(&rettv);
291     return res;
292 }
293 
294 /*
295  * Top level evaluation function, returning a string.  If "skip" is TRUE,
296  * only parsing to "nextcmd" is done, without reporting errors.  Return
297  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
298  */
299     char_u *
300 eval_to_string_skip(
301     char_u	*arg,
302     char_u	**nextcmd,
303     int		skip)	    /* only parse, don't execute */
304 {
305     typval_T	tv;
306     char_u	*retval;
307 
308     if (skip)
309 	++emsg_skip;
310     if (eval0(arg, &tv, nextcmd, !skip) == FAIL || skip)
311 	retval = NULL;
312     else
313     {
314 	retval = vim_strsave(tv_get_string(&tv));
315 	clear_tv(&tv);
316     }
317     if (skip)
318 	--emsg_skip;
319 
320     return retval;
321 }
322 
323 /*
324  * Skip over an expression at "*pp".
325  * Return FAIL for an error, OK otherwise.
326  */
327     int
328 skip_expr(char_u **pp)
329 {
330     typval_T	rettv;
331 
332     *pp = skipwhite(*pp);
333     return eval1(pp, &rettv, FALSE);
334 }
335 
336 /*
337  * Top level evaluation function, returning a string.
338  * When "convert" is TRUE convert a List into a sequence of lines and convert
339  * a Float to a String.
340  * Return pointer to allocated memory, or NULL for failure.
341  */
342     char_u *
343 eval_to_string(
344     char_u	*arg,
345     char_u	**nextcmd,
346     int		convert)
347 {
348     typval_T	tv;
349     char_u	*retval;
350     garray_T	ga;
351 #ifdef FEAT_FLOAT
352     char_u	numbuf[NUMBUFLEN];
353 #endif
354 
355     if (eval0(arg, &tv, nextcmd, TRUE) == FAIL)
356 	retval = NULL;
357     else
358     {
359 	if (convert && tv.v_type == VAR_LIST)
360 	{
361 	    ga_init2(&ga, (int)sizeof(char), 80);
362 	    if (tv.vval.v_list != NULL)
363 	    {
364 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
365 		if (tv.vval.v_list->lv_len > 0)
366 		    ga_append(&ga, NL);
367 	    }
368 	    ga_append(&ga, NUL);
369 	    retval = (char_u *)ga.ga_data;
370 	}
371 #ifdef FEAT_FLOAT
372 	else if (convert && tv.v_type == VAR_FLOAT)
373 	{
374 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
375 	    retval = vim_strsave(numbuf);
376 	}
377 #endif
378 	else
379 	    retval = vim_strsave(tv_get_string(&tv));
380 	clear_tv(&tv);
381     }
382 
383     return retval;
384 }
385 
386 /*
387  * Call eval_to_string() without using current local variables and using
388  * textlock.  When "use_sandbox" is TRUE use the sandbox.
389  */
390     char_u *
391 eval_to_string_safe(
392     char_u	*arg,
393     char_u	**nextcmd,
394     int		use_sandbox)
395 {
396     char_u	*retval;
397     funccal_entry_T funccal_entry;
398 
399     save_funccal(&funccal_entry);
400     if (use_sandbox)
401 	++sandbox;
402     ++textlock;
403     retval = eval_to_string(arg, nextcmd, FALSE);
404     if (use_sandbox)
405 	--sandbox;
406     --textlock;
407     restore_funccal();
408     return retval;
409 }
410 
411 /*
412  * Top level evaluation function, returning a number.
413  * Evaluates "expr" silently.
414  * Returns -1 for an error.
415  */
416     varnumber_T
417 eval_to_number(char_u *expr)
418 {
419     typval_T	rettv;
420     varnumber_T	retval;
421     char_u	*p = skipwhite(expr);
422 
423     ++emsg_off;
424 
425     if (eval1(&p, &rettv, TRUE) == FAIL)
426 	retval = -1;
427     else
428     {
429 	retval = tv_get_number_chk(&rettv, NULL);
430 	clear_tv(&rettv);
431     }
432     --emsg_off;
433 
434     return retval;
435 }
436 
437 /*
438  * Top level evaluation function.
439  * Returns an allocated typval_T with the result.
440  * Returns NULL when there is an error.
441  */
442     typval_T *
443 eval_expr(char_u *arg, char_u **nextcmd)
444 {
445     typval_T	*tv;
446 
447     tv = ALLOC_ONE(typval_T);
448     if (tv != NULL && eval0(arg, tv, nextcmd, TRUE) == FAIL)
449 	VIM_CLEAR(tv);
450 
451     return tv;
452 }
453 
454 /*
455  * Call some Vim script function and return the result in "*rettv".
456  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
457  * should have type VAR_UNKNOWN.
458  * Returns OK or FAIL.
459  */
460     int
461 call_vim_function(
462     char_u      *func,
463     int		argc,
464     typval_T	*argv,
465     typval_T	*rettv)
466 {
467     int		ret;
468     funcexe_T	funcexe;
469 
470     rettv->v_type = VAR_UNKNOWN;		/* clear_tv() uses this */
471     vim_memset(&funcexe, 0, sizeof(funcexe));
472     funcexe.firstline = curwin->w_cursor.lnum;
473     funcexe.lastline = curwin->w_cursor.lnum;
474     funcexe.evaluate = TRUE;
475     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
476     if (ret == FAIL)
477 	clear_tv(rettv);
478 
479     return ret;
480 }
481 
482 /*
483  * Call Vim script function "func" and return the result as a number.
484  * Returns -1 when calling the function fails.
485  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
486  * have type VAR_UNKNOWN.
487  */
488     varnumber_T
489 call_func_retnr(
490     char_u      *func,
491     int		argc,
492     typval_T	*argv)
493 {
494     typval_T	rettv;
495     varnumber_T	retval;
496 
497     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
498 	return -1;
499 
500     retval = tv_get_number_chk(&rettv, NULL);
501     clear_tv(&rettv);
502     return retval;
503 }
504 
505 /*
506  * Call Vim script function "func" and return the result as a string.
507  * Returns NULL when calling the function fails.
508  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
509  * have type VAR_UNKNOWN.
510  */
511     void *
512 call_func_retstr(
513     char_u      *func,
514     int		argc,
515     typval_T	*argv)
516 {
517     typval_T	rettv;
518     char_u	*retval;
519 
520     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
521 	return NULL;
522 
523     retval = vim_strsave(tv_get_string(&rettv));
524     clear_tv(&rettv);
525     return retval;
526 }
527 
528 /*
529  * Call Vim script function "func" and return the result as a List.
530  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
531  * have type VAR_UNKNOWN.
532  * Returns NULL when there is something wrong.
533  */
534     void *
535 call_func_retlist(
536     char_u      *func,
537     int		argc,
538     typval_T	*argv)
539 {
540     typval_T	rettv;
541 
542     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
543 	return NULL;
544 
545     if (rettv.v_type != VAR_LIST)
546     {
547 	clear_tv(&rettv);
548 	return NULL;
549     }
550 
551     return rettv.vval.v_list;
552 }
553 
554 #ifdef FEAT_FOLDING
555 /*
556  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
557  * it in "*cp".  Doesn't give error messages.
558  */
559     int
560 eval_foldexpr(char_u *arg, int *cp)
561 {
562     typval_T	tv;
563     varnumber_T	retval;
564     char_u	*s;
565     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
566 								   OPT_LOCAL);
567 
568     ++emsg_off;
569     if (use_sandbox)
570 	++sandbox;
571     ++textlock;
572     *cp = NUL;
573     if (eval0(arg, &tv, NULL, TRUE) == FAIL)
574 	retval = 0;
575     else
576     {
577 	/* If the result is a number, just return the number. */
578 	if (tv.v_type == VAR_NUMBER)
579 	    retval = tv.vval.v_number;
580 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
581 	    retval = 0;
582 	else
583 	{
584 	    /* If the result is a string, check if there is a non-digit before
585 	     * the number. */
586 	    s = tv.vval.v_string;
587 	    if (!VIM_ISDIGIT(*s) && *s != '-')
588 		*cp = *s++;
589 	    retval = atol((char *)s);
590 	}
591 	clear_tv(&tv);
592     }
593     --emsg_off;
594     if (use_sandbox)
595 	--sandbox;
596     --textlock;
597 
598     return (int)retval;
599 }
600 #endif
601 
602 /*
603  * Get an lval: variable, Dict item or List item that can be assigned a value
604  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
605  * "name.key", "name.key[expr]" etc.
606  * Indexing only works if "name" is an existing List or Dictionary.
607  * "name" points to the start of the name.
608  * If "rettv" is not NULL it points to the value to be assigned.
609  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
610  * wrong; must end in space or cmd separator.
611  *
612  * flags:
613  *  GLV_QUIET:       do not give error messages
614  *  GLV_READ_ONLY:   will not change the variable
615  *  GLV_NO_AUTOLOAD: do not use script autoloading
616  *
617  * Returns a pointer to just after the name, including indexes.
618  * When an evaluation error occurs "lp->ll_name" is NULL;
619  * Returns NULL for a parsing error.  Still need to free items in "lp"!
620  */
621     char_u *
622 get_lval(
623     char_u	*name,
624     typval_T	*rettv,
625     lval_T	*lp,
626     int		unlet,
627     int		skip,
628     int		flags,	    /* GLV_ values */
629     int		fne_flags)  /* flags for find_name_end() */
630 {
631     char_u	*p;
632     char_u	*expr_start, *expr_end;
633     int		cc;
634     dictitem_T	*v;
635     typval_T	var1;
636     typval_T	var2;
637     int		empty1 = FALSE;
638     listitem_T	*ni;
639     char_u	*key = NULL;
640     int		len;
641     hashtab_T	*ht;
642     int		quiet = flags & GLV_QUIET;
643 
644     /* Clear everything in "lp". */
645     vim_memset(lp, 0, sizeof(lval_T));
646 
647     if (skip)
648     {
649 	/* When skipping just find the end of the name. */
650 	lp->ll_name = name;
651 	return find_name_end(name, NULL, NULL, FNE_INCL_BR | fne_flags);
652     }
653 
654     /* Find the end of the name. */
655     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
656     if (expr_start != NULL)
657     {
658 	/* Don't expand the name when we already know there is an error. */
659 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
660 						    && *p != '[' && *p != '.')
661 	{
662 	    emsg(_(e_trailing));
663 	    return NULL;
664 	}
665 
666 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
667 	if (lp->ll_exp_name == NULL)
668 	{
669 	    /* Report an invalid expression in braces, unless the
670 	     * expression evaluation has been cancelled due to an
671 	     * aborting error, an interrupt, or an exception. */
672 	    if (!aborting() && !quiet)
673 	    {
674 		emsg_severe = TRUE;
675 		semsg(_(e_invarg2), name);
676 		return NULL;
677 	    }
678 	}
679 	lp->ll_name = lp->ll_exp_name;
680     }
681     else
682 	lp->ll_name = name;
683 
684     /* Without [idx] or .key we are done. */
685     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
686 	return p;
687 
688     cc = *p;
689     *p = NUL;
690     /* Only pass &ht when we would write to the variable, it prevents autoload
691      * as well. */
692     v = find_var(lp->ll_name, (flags & GLV_READ_ONLY) ? NULL : &ht,
693 						      flags & GLV_NO_AUTOLOAD);
694     if (v == NULL && !quiet)
695 	semsg(_(e_undefvar), lp->ll_name);
696     *p = cc;
697     if (v == NULL)
698 	return NULL;
699 
700     /*
701      * Loop until no more [idx] or .key is following.
702      */
703     lp->ll_tv = &v->di_tv;
704     var1.v_type = VAR_UNKNOWN;
705     var2.v_type = VAR_UNKNOWN;
706     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
707     {
708 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
709 		&& !(lp->ll_tv->v_type == VAR_DICT
710 					   && lp->ll_tv->vval.v_dict != NULL)
711 		&& !(lp->ll_tv->v_type == VAR_BLOB
712 					   && lp->ll_tv->vval.v_blob != NULL))
713 	{
714 	    if (!quiet)
715 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
716 	    return NULL;
717 	}
718 	if (lp->ll_range)
719 	{
720 	    if (!quiet)
721 		emsg(_("E708: [:] must come last"));
722 	    return NULL;
723 	}
724 
725 	len = -1;
726 	if (*p == '.')
727 	{
728 	    key = p + 1;
729 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
730 		;
731 	    if (len == 0)
732 	    {
733 		if (!quiet)
734 		    emsg(_(e_emptykey));
735 		return NULL;
736 	    }
737 	    p = key + len;
738 	}
739 	else
740 	{
741 	    /* Get the index [expr] or the first index [expr: ]. */
742 	    p = skipwhite(p + 1);
743 	    if (*p == ':')
744 		empty1 = TRUE;
745 	    else
746 	    {
747 		empty1 = FALSE;
748 		if (eval1(&p, &var1, TRUE) == FAIL)	/* recursive! */
749 		    return NULL;
750 		if (tv_get_string_chk(&var1) == NULL)
751 		{
752 		    /* not a number or string */
753 		    clear_tv(&var1);
754 		    return NULL;
755 		}
756 	    }
757 
758 	    /* Optionally get the second index [ :expr]. */
759 	    if (*p == ':')
760 	    {
761 		if (lp->ll_tv->v_type == VAR_DICT)
762 		{
763 		    if (!quiet)
764 			emsg(_(e_dictrange));
765 		    clear_tv(&var1);
766 		    return NULL;
767 		}
768 		if (rettv != NULL
769 			&& !(rettv->v_type == VAR_LIST
770 						 && rettv->vval.v_list != NULL)
771 			&& !(rettv->v_type == VAR_BLOB
772 						&& rettv->vval.v_blob != NULL))
773 		{
774 		    if (!quiet)
775 			emsg(_("E709: [:] requires a List or Blob value"));
776 		    clear_tv(&var1);
777 		    return NULL;
778 		}
779 		p = skipwhite(p + 1);
780 		if (*p == ']')
781 		    lp->ll_empty2 = TRUE;
782 		else
783 		{
784 		    lp->ll_empty2 = FALSE;
785 		    if (eval1(&p, &var2, TRUE) == FAIL)	/* recursive! */
786 		    {
787 			clear_tv(&var1);
788 			return NULL;
789 		    }
790 		    if (tv_get_string_chk(&var2) == NULL)
791 		    {
792 			/* not a number or string */
793 			clear_tv(&var1);
794 			clear_tv(&var2);
795 			return NULL;
796 		    }
797 		}
798 		lp->ll_range = TRUE;
799 	    }
800 	    else
801 		lp->ll_range = FALSE;
802 
803 	    if (*p != ']')
804 	    {
805 		if (!quiet)
806 		    emsg(_(e_missbrac));
807 		clear_tv(&var1);
808 		clear_tv(&var2);
809 		return NULL;
810 	    }
811 
812 	    /* Skip to past ']'. */
813 	    ++p;
814 	}
815 
816 	if (lp->ll_tv->v_type == VAR_DICT)
817 	{
818 	    if (len == -1)
819 	    {
820 		/* "[key]": get key from "var1" */
821 		key = tv_get_string_chk(&var1);	/* is number or string */
822 		if (key == NULL)
823 		{
824 		    clear_tv(&var1);
825 		    return NULL;
826 		}
827 	    }
828 	    lp->ll_list = NULL;
829 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
830 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
831 
832 	    /* When assigning to a scope dictionary check that a function and
833 	     * variable name is valid (only variable name unless it is l: or
834 	     * g: dictionary). Disallow overwriting a builtin function. */
835 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
836 	    {
837 		int prevval;
838 		int wrong;
839 
840 		if (len != -1)
841 		{
842 		    prevval = key[len];
843 		    key[len] = NUL;
844 		}
845 		else
846 		    prevval = 0; /* avoid compiler warning */
847 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
848 			       && rettv->v_type == VAR_FUNC
849 			       && var_check_func_name(key, lp->ll_di == NULL))
850 			|| !valid_varname(key);
851 		if (len != -1)
852 		    key[len] = prevval;
853 		if (wrong)
854 		    return NULL;
855 	    }
856 
857 	    if (lp->ll_di == NULL)
858 	    {
859 		// Can't add "v:" or "a:" variable.
860 		if (lp->ll_dict == get_vimvar_dict()
861 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
862 		{
863 		    semsg(_(e_illvar), name);
864 		    clear_tv(&var1);
865 		    return NULL;
866 		}
867 
868 		// Key does not exist in dict: may need to add it.
869 		if (*p == '[' || *p == '.' || unlet)
870 		{
871 		    if (!quiet)
872 			semsg(_(e_dictkey), key);
873 		    clear_tv(&var1);
874 		    return NULL;
875 		}
876 		if (len == -1)
877 		    lp->ll_newkey = vim_strsave(key);
878 		else
879 		    lp->ll_newkey = vim_strnsave(key, len);
880 		clear_tv(&var1);
881 		if (lp->ll_newkey == NULL)
882 		    p = NULL;
883 		break;
884 	    }
885 	    /* existing variable, need to check if it can be changed */
886 	    else if ((flags & GLV_READ_ONLY) == 0
887 			     && var_check_ro(lp->ll_di->di_flags, name, FALSE))
888 	    {
889 		clear_tv(&var1);
890 		return NULL;
891 	    }
892 
893 	    clear_tv(&var1);
894 	    lp->ll_tv = &lp->ll_di->di_tv;
895 	}
896 	else if (lp->ll_tv->v_type == VAR_BLOB)
897 	{
898 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
899 
900 	    /*
901 	     * Get the number and item for the only or first index of the List.
902 	     */
903 	    if (empty1)
904 		lp->ll_n1 = 0;
905 	    else
906 		// is number or string
907 		lp->ll_n1 = (long)tv_get_number(&var1);
908 	    clear_tv(&var1);
909 
910 	    if (lp->ll_n1 < 0
911 		    || lp->ll_n1 > bloblen
912 		    || (lp->ll_range && lp->ll_n1 == bloblen))
913 	    {
914 		if (!quiet)
915 		    semsg(_(e_blobidx), lp->ll_n1);
916 		clear_tv(&var2);
917 		return NULL;
918 	    }
919 	    if (lp->ll_range && !lp->ll_empty2)
920 	    {
921 		lp->ll_n2 = (long)tv_get_number(&var2);
922 		clear_tv(&var2);
923 		if (lp->ll_n2 < 0
924 			|| lp->ll_n2 >= bloblen
925 			|| lp->ll_n2 < lp->ll_n1)
926 		{
927 		    if (!quiet)
928 			semsg(_(e_blobidx), lp->ll_n2);
929 		    return NULL;
930 		}
931 	    }
932 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
933 	    lp->ll_tv = NULL;
934 	    break;
935 	}
936 	else
937 	{
938 	    /*
939 	     * Get the number and item for the only or first index of the List.
940 	     */
941 	    if (empty1)
942 		lp->ll_n1 = 0;
943 	    else
944 		/* is number or string */
945 		lp->ll_n1 = (long)tv_get_number(&var1);
946 	    clear_tv(&var1);
947 
948 	    lp->ll_dict = NULL;
949 	    lp->ll_list = lp->ll_tv->vval.v_list;
950 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
951 	    if (lp->ll_li == NULL)
952 	    {
953 		if (lp->ll_n1 < 0)
954 		{
955 		    lp->ll_n1 = 0;
956 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
957 		}
958 	    }
959 	    if (lp->ll_li == NULL)
960 	    {
961 		clear_tv(&var2);
962 		if (!quiet)
963 		    semsg(_(e_listidx), lp->ll_n1);
964 		return NULL;
965 	    }
966 
967 	    /*
968 	     * May need to find the item or absolute index for the second
969 	     * index of a range.
970 	     * When no index given: "lp->ll_empty2" is TRUE.
971 	     * Otherwise "lp->ll_n2" is set to the second index.
972 	     */
973 	    if (lp->ll_range && !lp->ll_empty2)
974 	    {
975 		lp->ll_n2 = (long)tv_get_number(&var2);
976 						    /* is number or string */
977 		clear_tv(&var2);
978 		if (lp->ll_n2 < 0)
979 		{
980 		    ni = list_find(lp->ll_list, lp->ll_n2);
981 		    if (ni == NULL)
982 		    {
983 			if (!quiet)
984 			    semsg(_(e_listidx), lp->ll_n2);
985 			return NULL;
986 		    }
987 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
988 		}
989 
990 		/* Check that lp->ll_n2 isn't before lp->ll_n1. */
991 		if (lp->ll_n1 < 0)
992 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
993 		if (lp->ll_n2 < lp->ll_n1)
994 		{
995 		    if (!quiet)
996 			semsg(_(e_listidx), lp->ll_n2);
997 		    return NULL;
998 		}
999 	    }
1000 
1001 	    lp->ll_tv = &lp->ll_li->li_tv;
1002 	}
1003     }
1004 
1005     clear_tv(&var1);
1006     return p;
1007 }
1008 
1009 /*
1010  * Clear lval "lp" that was filled by get_lval().
1011  */
1012     void
1013 clear_lval(lval_T *lp)
1014 {
1015     vim_free(lp->ll_exp_name);
1016     vim_free(lp->ll_newkey);
1017 }
1018 
1019 /*
1020  * Set a variable that was parsed by get_lval() to "rettv".
1021  * "endp" points to just after the parsed name.
1022  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
1023  * "%" for "%=", "." for ".=" or "=" for "=".
1024  */
1025     void
1026 set_var_lval(
1027     lval_T	*lp,
1028     char_u	*endp,
1029     typval_T	*rettv,
1030     int		copy,
1031     int		is_const,    // Disallow to modify existing variable for :const
1032     char_u	*op)
1033 {
1034     int		cc;
1035     listitem_T	*ri;
1036     dictitem_T	*di;
1037 
1038     if (lp->ll_tv == NULL)
1039     {
1040 	cc = *endp;
1041 	*endp = NUL;
1042 	if (lp->ll_blob != NULL)
1043 	{
1044 	    int	    error = FALSE, val;
1045 
1046 	    if (op != NULL && *op != '=')
1047 	    {
1048 		semsg(_(e_letwrong), op);
1049 		return;
1050 	    }
1051 
1052 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
1053 	    {
1054 		int	il, ir;
1055 
1056 		if (lp->ll_empty2)
1057 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
1058 
1059 		if (lp->ll_n2 - lp->ll_n1 + 1 != blob_len(rettv->vval.v_blob))
1060 		{
1061 		    emsg(_("E972: Blob value does not have the right number of bytes"));
1062 		    return;
1063 		}
1064 		if (lp->ll_empty2)
1065 		    lp->ll_n2 = blob_len(lp->ll_blob);
1066 
1067 		ir = 0;
1068 		for (il = lp->ll_n1; il <= lp->ll_n2; il++)
1069 		    blob_set(lp->ll_blob, il,
1070 			    blob_get(rettv->vval.v_blob, ir++));
1071 	    }
1072 	    else
1073 	    {
1074 		val = (int)tv_get_number_chk(rettv, &error);
1075 		if (!error)
1076 		{
1077 		    garray_T *gap = &lp->ll_blob->bv_ga;
1078 
1079 		    // Allow for appending a byte.  Setting a byte beyond
1080 		    // the end is an error otherwise.
1081 		    if (lp->ll_n1 < gap->ga_len
1082 			    || (lp->ll_n1 == gap->ga_len
1083 				&& ga_grow(&lp->ll_blob->bv_ga, 1) == OK))
1084 		    {
1085 			blob_set(lp->ll_blob, lp->ll_n1, val);
1086 			if (lp->ll_n1 == gap->ga_len)
1087 			    ++gap->ga_len;
1088 		    }
1089 		    // error for invalid range was already given in get_lval()
1090 		}
1091 	    }
1092 	}
1093 	else if (op != NULL && *op != '=')
1094 	{
1095 	    typval_T tv;
1096 
1097 	    if (is_const)
1098 	    {
1099 		emsg(_(e_cannot_mod));
1100 		*endp = cc;
1101 		return;
1102 	    }
1103 
1104 	    // handle +=, -=, *=, /=, %= and .=
1105 	    di = NULL;
1106 	    if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
1107 					     &tv, &di, TRUE, FALSE) == OK)
1108 	    {
1109 		if ((di == NULL
1110 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
1111 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
1112 			&& tv_op(&tv, rettv, op) == OK)
1113 		    set_var(lp->ll_name, &tv, FALSE);
1114 		clear_tv(&tv);
1115 	    }
1116 	}
1117 	else
1118 	    set_var_const(lp->ll_name, rettv, copy, is_const);
1119 	*endp = cc;
1120     }
1121     else if (var_check_lock(lp->ll_newkey == NULL
1122 		? lp->ll_tv->v_lock
1123 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
1124 	;
1125     else if (lp->ll_range)
1126     {
1127 	listitem_T *ll_li = lp->ll_li;
1128 	int	    ll_n1 = lp->ll_n1;
1129 
1130 	if (is_const)
1131 	{
1132 	    emsg(_("E996: Cannot lock a range"));
1133 	    return;
1134 	}
1135 
1136 	/*
1137 	 * Check whether any of the list items is locked
1138 	 */
1139 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
1140 	{
1141 	    if (var_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
1142 		return;
1143 	    ri = ri->li_next;
1144 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
1145 		break;
1146 	    ll_li = ll_li->li_next;
1147 	    ++ll_n1;
1148 	}
1149 
1150 	/*
1151 	 * Assign the List values to the list items.
1152 	 */
1153 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
1154 	{
1155 	    if (op != NULL && *op != '=')
1156 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
1157 	    else
1158 	    {
1159 		clear_tv(&lp->ll_li->li_tv);
1160 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
1161 	    }
1162 	    ri = ri->li_next;
1163 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
1164 		break;
1165 	    if (lp->ll_li->li_next == NULL)
1166 	    {
1167 		/* Need to add an empty item. */
1168 		if (list_append_number(lp->ll_list, 0) == FAIL)
1169 		{
1170 		    ri = NULL;
1171 		    break;
1172 		}
1173 	    }
1174 	    lp->ll_li = lp->ll_li->li_next;
1175 	    ++lp->ll_n1;
1176 	}
1177 	if (ri != NULL)
1178 	    emsg(_("E710: List value has more items than target"));
1179 	else if (lp->ll_empty2
1180 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
1181 		: lp->ll_n1 != lp->ll_n2)
1182 	    emsg(_("E711: List value has not enough items"));
1183     }
1184     else
1185     {
1186 	/*
1187 	 * Assign to a List or Dictionary item.
1188 	 */
1189 	if (is_const)
1190 	{
1191 	    emsg(_("E996: Cannot lock a list or dict"));
1192 	    return;
1193 	}
1194 	if (lp->ll_newkey != NULL)
1195 	{
1196 	    if (op != NULL && *op != '=')
1197 	    {
1198 		semsg(_(e_letwrong), op);
1199 		return;
1200 	    }
1201 
1202 	    /* Need to add an item to the Dictionary. */
1203 	    di = dictitem_alloc(lp->ll_newkey);
1204 	    if (di == NULL)
1205 		return;
1206 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
1207 	    {
1208 		vim_free(di);
1209 		return;
1210 	    }
1211 	    lp->ll_tv = &di->di_tv;
1212 	}
1213 	else if (op != NULL && *op != '=')
1214 	{
1215 	    tv_op(lp->ll_tv, rettv, op);
1216 	    return;
1217 	}
1218 	else
1219 	    clear_tv(lp->ll_tv);
1220 
1221 	/*
1222 	 * Assign the value to the variable or list item.
1223 	 */
1224 	if (copy)
1225 	    copy_tv(rettv, lp->ll_tv);
1226 	else
1227 	{
1228 	    *lp->ll_tv = *rettv;
1229 	    lp->ll_tv->v_lock = 0;
1230 	    init_tv(rettv);
1231 	}
1232     }
1233 }
1234 
1235 /*
1236  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
1237  * and "tv1 .= tv2"
1238  * Returns OK or FAIL.
1239  */
1240     static int
1241 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
1242 {
1243     varnumber_T	n;
1244     char_u	numbuf[NUMBUFLEN];
1245     char_u	*s;
1246 
1247     /* Can't do anything with a Funcref, Dict, v:true on the right. */
1248     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
1249 						&& tv2->v_type != VAR_SPECIAL)
1250     {
1251 	switch (tv1->v_type)
1252 	{
1253 	    case VAR_UNKNOWN:
1254 	    case VAR_DICT:
1255 	    case VAR_FUNC:
1256 	    case VAR_PARTIAL:
1257 	    case VAR_SPECIAL:
1258 	    case VAR_JOB:
1259 	    case VAR_CHANNEL:
1260 		break;
1261 
1262 	    case VAR_BLOB:
1263 		if (*op != '+' || tv2->v_type != VAR_BLOB)
1264 		    break;
1265 		// BLOB += BLOB
1266 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
1267 		{
1268 		    blob_T  *b1 = tv1->vval.v_blob;
1269 		    blob_T  *b2 = tv2->vval.v_blob;
1270 		    int	i, len = blob_len(b2);
1271 		    for (i = 0; i < len; i++)
1272 			ga_append(&b1->bv_ga, blob_get(b2, i));
1273 		}
1274 		return OK;
1275 
1276 	    case VAR_LIST:
1277 		if (*op != '+' || tv2->v_type != VAR_LIST)
1278 		    break;
1279 		// List += List
1280 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
1281 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
1282 		return OK;
1283 
1284 	    case VAR_NUMBER:
1285 	    case VAR_STRING:
1286 		if (tv2->v_type == VAR_LIST)
1287 		    break;
1288 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
1289 		{
1290 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
1291 		    n = tv_get_number(tv1);
1292 #ifdef FEAT_FLOAT
1293 		    if (tv2->v_type == VAR_FLOAT)
1294 		    {
1295 			float_T f = n;
1296 
1297 			if (*op == '%')
1298 			    break;
1299 			switch (*op)
1300 			{
1301 			    case '+': f += tv2->vval.v_float; break;
1302 			    case '-': f -= tv2->vval.v_float; break;
1303 			    case '*': f *= tv2->vval.v_float; break;
1304 			    case '/': f /= tv2->vval.v_float; break;
1305 			}
1306 			clear_tv(tv1);
1307 			tv1->v_type = VAR_FLOAT;
1308 			tv1->vval.v_float = f;
1309 		    }
1310 		    else
1311 #endif
1312 		    {
1313 			switch (*op)
1314 			{
1315 			    case '+': n += tv_get_number(tv2); break;
1316 			    case '-': n -= tv_get_number(tv2); break;
1317 			    case '*': n *= tv_get_number(tv2); break;
1318 			    case '/': n = num_divide(n, tv_get_number(tv2)); break;
1319 			    case '%': n = num_modulus(n, tv_get_number(tv2)); break;
1320 			}
1321 			clear_tv(tv1);
1322 			tv1->v_type = VAR_NUMBER;
1323 			tv1->vval.v_number = n;
1324 		    }
1325 		}
1326 		else
1327 		{
1328 		    if (tv2->v_type == VAR_FLOAT)
1329 			break;
1330 
1331 		    // str .= str
1332 		    s = tv_get_string(tv1);
1333 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
1334 		    clear_tv(tv1);
1335 		    tv1->v_type = VAR_STRING;
1336 		    tv1->vval.v_string = s;
1337 		}
1338 		return OK;
1339 
1340 	    case VAR_FLOAT:
1341 #ifdef FEAT_FLOAT
1342 		{
1343 		    float_T f;
1344 
1345 		    if (*op == '%' || *op == '.'
1346 				   || (tv2->v_type != VAR_FLOAT
1347 				    && tv2->v_type != VAR_NUMBER
1348 				    && tv2->v_type != VAR_STRING))
1349 			break;
1350 		    if (tv2->v_type == VAR_FLOAT)
1351 			f = tv2->vval.v_float;
1352 		    else
1353 			f = tv_get_number(tv2);
1354 		    switch (*op)
1355 		    {
1356 			case '+': tv1->vval.v_float += f; break;
1357 			case '-': tv1->vval.v_float -= f; break;
1358 			case '*': tv1->vval.v_float *= f; break;
1359 			case '/': tv1->vval.v_float /= f; break;
1360 		    }
1361 		}
1362 #endif
1363 		return OK;
1364 	}
1365     }
1366 
1367     semsg(_(e_letwrong), op);
1368     return FAIL;
1369 }
1370 
1371 /*
1372  * Evaluate the expression used in a ":for var in expr" command.
1373  * "arg" points to "var".
1374  * Set "*errp" to TRUE for an error, FALSE otherwise;
1375  * Return a pointer that holds the info.  Null when there is an error.
1376  */
1377     void *
1378 eval_for_line(
1379     char_u	*arg,
1380     int		*errp,
1381     char_u	**nextcmdp,
1382     int		skip)
1383 {
1384     forinfo_T	*fi;
1385     char_u	*expr;
1386     typval_T	tv;
1387     list_T	*l;
1388 
1389     *errp = TRUE;	/* default: there is an error */
1390 
1391     fi = ALLOC_CLEAR_ONE(forinfo_T);
1392     if (fi == NULL)
1393 	return NULL;
1394 
1395     expr = skip_var_list(arg, &fi->fi_varcount, &fi->fi_semicolon);
1396     if (expr == NULL)
1397 	return fi;
1398 
1399     expr = skipwhite(expr);
1400     if (expr[0] != 'i' || expr[1] != 'n' || !VIM_ISWHITE(expr[2]))
1401     {
1402 	emsg(_("E690: Missing \"in\" after :for"));
1403 	return fi;
1404     }
1405 
1406     if (skip)
1407 	++emsg_skip;
1408     if (eval0(skipwhite(expr + 2), &tv, nextcmdp, !skip) == OK)
1409     {
1410 	*errp = FALSE;
1411 	if (!skip)
1412 	{
1413 	    if (tv.v_type == VAR_LIST)
1414 	    {
1415 		l = tv.vval.v_list;
1416 		if (l == NULL)
1417 		{
1418 		    // a null list is like an empty list: do nothing
1419 		    clear_tv(&tv);
1420 		}
1421 		else
1422 		{
1423 		    // No need to increment the refcount, it's already set for
1424 		    // the list being used in "tv".
1425 		    fi->fi_list = l;
1426 		    list_add_watch(l, &fi->fi_lw);
1427 		    fi->fi_lw.lw_item = l->lv_first;
1428 		}
1429 	    }
1430 	    else if (tv.v_type == VAR_BLOB)
1431 	    {
1432 		fi->fi_bi = 0;
1433 		if (tv.vval.v_blob != NULL)
1434 		{
1435 		    typval_T btv;
1436 
1437 		    // Make a copy, so that the iteration still works when the
1438 		    // blob is changed.
1439 		    blob_copy(&tv, &btv);
1440 		    fi->fi_blob = btv.vval.v_blob;
1441 		}
1442 		clear_tv(&tv);
1443 	    }
1444 	    else
1445 	    {
1446 		emsg(_(e_listreq));
1447 		clear_tv(&tv);
1448 	    }
1449 	}
1450     }
1451     if (skip)
1452 	--emsg_skip;
1453 
1454     return fi;
1455 }
1456 
1457 /*
1458  * Use the first item in a ":for" list.  Advance to the next.
1459  * Assign the values to the variable (list).  "arg" points to the first one.
1460  * Return TRUE when a valid item was found, FALSE when at end of list or
1461  * something wrong.
1462  */
1463     int
1464 next_for_item(void *fi_void, char_u *arg)
1465 {
1466     forinfo_T	*fi = (forinfo_T *)fi_void;
1467     int		result;
1468     listitem_T	*item;
1469 
1470     if (fi->fi_blob != NULL)
1471     {
1472 	typval_T	tv;
1473 
1474 	if (fi->fi_bi >= blob_len(fi->fi_blob))
1475 	    return FALSE;
1476 	tv.v_type = VAR_NUMBER;
1477 	tv.v_lock = VAR_FIXED;
1478 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
1479 	++fi->fi_bi;
1480 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1481 					   fi->fi_varcount, FALSE, NULL) == OK;
1482     }
1483 
1484     item = fi->fi_lw.lw_item;
1485     if (item == NULL)
1486 	result = FALSE;
1487     else
1488     {
1489 	fi->fi_lw.lw_item = item->li_next;
1490 	result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
1491 					  fi->fi_varcount, FALSE, NULL) == OK);
1492     }
1493     return result;
1494 }
1495 
1496 /*
1497  * Free the structure used to store info used by ":for".
1498  */
1499     void
1500 free_for_info(void *fi_void)
1501 {
1502     forinfo_T    *fi = (forinfo_T *)fi_void;
1503 
1504     if (fi != NULL && fi->fi_list != NULL)
1505     {
1506 	list_rem_watch(fi->fi_list, &fi->fi_lw);
1507 	list_unref(fi->fi_list);
1508     }
1509     if (fi != NULL && fi->fi_blob != NULL)
1510 	blob_unref(fi->fi_blob);
1511     vim_free(fi);
1512 }
1513 
1514     void
1515 set_context_for_expression(
1516     expand_T	*xp,
1517     char_u	*arg,
1518     cmdidx_T	cmdidx)
1519 {
1520     int		got_eq = FALSE;
1521     int		c;
1522     char_u	*p;
1523 
1524     if (cmdidx == CMD_let)
1525     {
1526 	xp->xp_context = EXPAND_USER_VARS;
1527 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
1528 	{
1529 	    /* ":let var1 var2 ...": find last space. */
1530 	    for (p = arg + STRLEN(arg); p >= arg; )
1531 	    {
1532 		xp->xp_pattern = p;
1533 		MB_PTR_BACK(arg, p);
1534 		if (VIM_ISWHITE(*p))
1535 		    break;
1536 	    }
1537 	    return;
1538 	}
1539     }
1540     else
1541 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
1542 							  : EXPAND_EXPRESSION;
1543     while ((xp->xp_pattern = vim_strpbrk(arg,
1544 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
1545     {
1546 	c = *xp->xp_pattern;
1547 	if (c == '&')
1548 	{
1549 	    c = xp->xp_pattern[1];
1550 	    if (c == '&')
1551 	    {
1552 		++xp->xp_pattern;
1553 		xp->xp_context = cmdidx != CMD_let || got_eq
1554 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
1555 	    }
1556 	    else if (c != ' ')
1557 	    {
1558 		xp->xp_context = EXPAND_SETTINGS;
1559 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
1560 		    xp->xp_pattern += 2;
1561 
1562 	    }
1563 	}
1564 	else if (c == '$')
1565 	{
1566 	    /* environment variable */
1567 	    xp->xp_context = EXPAND_ENV_VARS;
1568 	}
1569 	else if (c == '=')
1570 	{
1571 	    got_eq = TRUE;
1572 	    xp->xp_context = EXPAND_EXPRESSION;
1573 	}
1574 	else if (c == '#'
1575 		&& xp->xp_context == EXPAND_EXPRESSION)
1576 	{
1577 	    /* Autoload function/variable contains '#'. */
1578 	    break;
1579 	}
1580 	else if ((c == '<' || c == '#')
1581 		&& xp->xp_context == EXPAND_FUNCTIONS
1582 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
1583 	{
1584 	    /* Function name can start with "<SNR>" and contain '#'. */
1585 	    break;
1586 	}
1587 	else if (cmdidx != CMD_let || got_eq)
1588 	{
1589 	    if (c == '"')	    /* string */
1590 	    {
1591 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
1592 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
1593 			++xp->xp_pattern;
1594 		xp->xp_context = EXPAND_NOTHING;
1595 	    }
1596 	    else if (c == '\'')	    /* literal string */
1597 	    {
1598 		/* Trick: '' is like stopping and starting a literal string. */
1599 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
1600 		    /* skip */ ;
1601 		xp->xp_context = EXPAND_NOTHING;
1602 	    }
1603 	    else if (c == '|')
1604 	    {
1605 		if (xp->xp_pattern[1] == '|')
1606 		{
1607 		    ++xp->xp_pattern;
1608 		    xp->xp_context = EXPAND_EXPRESSION;
1609 		}
1610 		else
1611 		    xp->xp_context = EXPAND_COMMANDS;
1612 	    }
1613 	    else
1614 		xp->xp_context = EXPAND_EXPRESSION;
1615 	}
1616 	else
1617 	    /* Doesn't look like something valid, expand as an expression
1618 	     * anyway. */
1619 	    xp->xp_context = EXPAND_EXPRESSION;
1620 	arg = xp->xp_pattern;
1621 	if (*arg != NUL)
1622 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
1623 		/* skip */ ;
1624     }
1625     xp->xp_pattern = arg;
1626 }
1627 
1628 /*
1629  * Return TRUE if "pat" matches "text".
1630  * Does not use 'cpo' and always uses 'magic'.
1631  */
1632     int
1633 pattern_match(char_u *pat, char_u *text, int ic)
1634 {
1635     int		matches = FALSE;
1636     char_u	*save_cpo;
1637     regmatch_T	regmatch;
1638 
1639     /* avoid 'l' flag in 'cpoptions' */
1640     save_cpo = p_cpo;
1641     p_cpo = (char_u *)"";
1642     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1643     if (regmatch.regprog != NULL)
1644     {
1645 	regmatch.rm_ic = ic;
1646 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
1647 	vim_regfree(regmatch.regprog);
1648     }
1649     p_cpo = save_cpo;
1650     return matches;
1651 }
1652 
1653 /*
1654  * Handle a name followed by "(".  Both for just "name(arg)" and for
1655  * "expr->name(arg)".
1656  * Returns OK or FAIL.
1657  */
1658     static int
1659 eval_func(
1660 	char_u	    **arg,	// points to "(", will be advanced
1661 	char_u	    *name,
1662 	int	    name_len,
1663 	typval_T    *rettv,
1664 	int	    evaluate,
1665 	typval_T    *basetv)	// "expr" for "expr->name(arg)"
1666 {
1667     char_u	*s = name;
1668     int		len = name_len;
1669     partial_T	*partial;
1670     int		ret = OK;
1671 
1672     if (!evaluate)
1673 	check_vars(s, len);
1674 
1675     /* If "s" is the name of a variable of type VAR_FUNC
1676      * use its contents. */
1677     s = deref_func_name(s, &len, &partial, !evaluate);
1678 
1679     /* Need to make a copy, in case evaluating the arguments makes
1680      * the name invalid. */
1681     s = vim_strsave(s);
1682     if (s == NULL)
1683 	ret = FAIL;
1684     else
1685     {
1686 	funcexe_T funcexe;
1687 
1688 	// Invoke the function.
1689 	vim_memset(&funcexe, 0, sizeof(funcexe));
1690 	funcexe.firstline = curwin->w_cursor.lnum;
1691 	funcexe.lastline = curwin->w_cursor.lnum;
1692 	funcexe.evaluate = evaluate;
1693 	funcexe.partial = partial;
1694 	funcexe.basetv = basetv;
1695 	ret = get_func_tv(s, len, rettv, arg, &funcexe);
1696     }
1697     vim_free(s);
1698 
1699     /* If evaluate is FALSE rettv->v_type was not set in
1700      * get_func_tv, but it's needed in handle_subscript() to parse
1701      * what follows. So set it here. */
1702     if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
1703     {
1704 	rettv->vval.v_string = NULL;
1705 	rettv->v_type = VAR_FUNC;
1706     }
1707 
1708     /* Stop the expression evaluation when immediately
1709      * aborting on error, or when an interrupt occurred or
1710      * an exception was thrown but not caught. */
1711     if (evaluate && aborting())
1712     {
1713 	if (ret == OK)
1714 	    clear_tv(rettv);
1715 	ret = FAIL;
1716     }
1717     return ret;
1718 }
1719 
1720 /*
1721  * The "evaluate" argument: When FALSE, the argument is only parsed but not
1722  * executed.  The function may return OK, but the rettv will be of type
1723  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
1724  */
1725 
1726 /*
1727  * Handle zero level expression.
1728  * This calls eval1() and handles error message and nextcmd.
1729  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
1730  * Note: "rettv.v_lock" is not set.
1731  * Return OK or FAIL.
1732  */
1733     int
1734 eval0(
1735     char_u	*arg,
1736     typval_T	*rettv,
1737     char_u	**nextcmd,
1738     int		evaluate)
1739 {
1740     int		ret;
1741     char_u	*p;
1742     int		did_emsg_before = did_emsg;
1743     int		called_emsg_before = called_emsg;
1744 
1745     p = skipwhite(arg);
1746     ret = eval1(&p, rettv, evaluate);
1747     if (ret == FAIL || !ends_excmd(*p))
1748     {
1749 	if (ret != FAIL)
1750 	    clear_tv(rettv);
1751 	/*
1752 	 * Report the invalid expression unless the expression evaluation has
1753 	 * been cancelled due to an aborting error, an interrupt, or an
1754 	 * exception, or we already gave a more specific error.
1755 	 * Also check called_emsg for when using assert_fails().
1756 	 */
1757 	if (!aborting() && did_emsg == did_emsg_before
1758 					  && called_emsg == called_emsg_before)
1759 	    semsg(_(e_invexpr2), arg);
1760 	ret = FAIL;
1761     }
1762     if (nextcmd != NULL)
1763 	*nextcmd = check_nextcmd(p);
1764 
1765     return ret;
1766 }
1767 
1768 /*
1769  * Handle top level expression:
1770  *	expr2 ? expr1 : expr1
1771  *
1772  * "arg" must point to the first non-white of the expression.
1773  * "arg" is advanced to the next non-white after the recognized expression.
1774  *
1775  * Note: "rettv.v_lock" is not set.
1776  *
1777  * Return OK or FAIL.
1778  */
1779     int
1780 eval1(char_u **arg, typval_T *rettv, int evaluate)
1781 {
1782     int		result;
1783     typval_T	var2;
1784 
1785     /*
1786      * Get the first variable.
1787      */
1788     if (eval2(arg, rettv, evaluate) == FAIL)
1789 	return FAIL;
1790 
1791     if ((*arg)[0] == '?')
1792     {
1793 	result = FALSE;
1794 	if (evaluate)
1795 	{
1796 	    int		error = FALSE;
1797 
1798 	    if (tv_get_number_chk(rettv, &error) != 0)
1799 		result = TRUE;
1800 	    clear_tv(rettv);
1801 	    if (error)
1802 		return FAIL;
1803 	}
1804 
1805 	/*
1806 	 * Get the second variable.
1807 	 */
1808 	*arg = skipwhite(*arg + 1);
1809 	if (eval1(arg, rettv, evaluate && result) == FAIL) /* recursive! */
1810 	    return FAIL;
1811 
1812 	/*
1813 	 * Check for the ":".
1814 	 */
1815 	if ((*arg)[0] != ':')
1816 	{
1817 	    emsg(_("E109: Missing ':' after '?'"));
1818 	    if (evaluate && result)
1819 		clear_tv(rettv);
1820 	    return FAIL;
1821 	}
1822 
1823 	/*
1824 	 * Get the third variable.
1825 	 */
1826 	*arg = skipwhite(*arg + 1);
1827 	if (eval1(arg, &var2, evaluate && !result) == FAIL) /* recursive! */
1828 	{
1829 	    if (evaluate && result)
1830 		clear_tv(rettv);
1831 	    return FAIL;
1832 	}
1833 	if (evaluate && !result)
1834 	    *rettv = var2;
1835     }
1836 
1837     return OK;
1838 }
1839 
1840 /*
1841  * Handle first level expression:
1842  *	expr2 || expr2 || expr2	    logical OR
1843  *
1844  * "arg" must point to the first non-white of the expression.
1845  * "arg" is advanced to the next non-white after the recognized expression.
1846  *
1847  * Return OK or FAIL.
1848  */
1849     static int
1850 eval2(char_u **arg, typval_T *rettv, int evaluate)
1851 {
1852     typval_T	var2;
1853     long	result;
1854     int		first;
1855     int		error = FALSE;
1856 
1857     /*
1858      * Get the first variable.
1859      */
1860     if (eval3(arg, rettv, evaluate) == FAIL)
1861 	return FAIL;
1862 
1863     /*
1864      * Repeat until there is no following "||".
1865      */
1866     first = TRUE;
1867     result = FALSE;
1868     while ((*arg)[0] == '|' && (*arg)[1] == '|')
1869     {
1870 	if (evaluate && first)
1871 	{
1872 	    if (tv_get_number_chk(rettv, &error) != 0)
1873 		result = TRUE;
1874 	    clear_tv(rettv);
1875 	    if (error)
1876 		return FAIL;
1877 	    first = FALSE;
1878 	}
1879 
1880 	/*
1881 	 * Get the second variable.
1882 	 */
1883 	*arg = skipwhite(*arg + 2);
1884 	if (eval3(arg, &var2, evaluate && !result) == FAIL)
1885 	    return FAIL;
1886 
1887 	/*
1888 	 * Compute the result.
1889 	 */
1890 	if (evaluate && !result)
1891 	{
1892 	    if (tv_get_number_chk(&var2, &error) != 0)
1893 		result = TRUE;
1894 	    clear_tv(&var2);
1895 	    if (error)
1896 		return FAIL;
1897 	}
1898 	if (evaluate)
1899 	{
1900 	    rettv->v_type = VAR_NUMBER;
1901 	    rettv->vval.v_number = result;
1902 	}
1903     }
1904 
1905     return OK;
1906 }
1907 
1908 /*
1909  * Handle second level expression:
1910  *	expr3 && expr3 && expr3	    logical AND
1911  *
1912  * "arg" must point to the first non-white of the expression.
1913  * "arg" is advanced to the next non-white after the recognized expression.
1914  *
1915  * Return OK or FAIL.
1916  */
1917     static int
1918 eval3(char_u **arg, typval_T *rettv, int evaluate)
1919 {
1920     typval_T	var2;
1921     long	result;
1922     int		first;
1923     int		error = FALSE;
1924 
1925     /*
1926      * Get the first variable.
1927      */
1928     if (eval4(arg, rettv, evaluate) == FAIL)
1929 	return FAIL;
1930 
1931     /*
1932      * Repeat until there is no following "&&".
1933      */
1934     first = TRUE;
1935     result = TRUE;
1936     while ((*arg)[0] == '&' && (*arg)[1] == '&')
1937     {
1938 	if (evaluate && first)
1939 	{
1940 	    if (tv_get_number_chk(rettv, &error) == 0)
1941 		result = FALSE;
1942 	    clear_tv(rettv);
1943 	    if (error)
1944 		return FAIL;
1945 	    first = FALSE;
1946 	}
1947 
1948 	/*
1949 	 * Get the second variable.
1950 	 */
1951 	*arg = skipwhite(*arg + 2);
1952 	if (eval4(arg, &var2, evaluate && result) == FAIL)
1953 	    return FAIL;
1954 
1955 	/*
1956 	 * Compute the result.
1957 	 */
1958 	if (evaluate && result)
1959 	{
1960 	    if (tv_get_number_chk(&var2, &error) == 0)
1961 		result = FALSE;
1962 	    clear_tv(&var2);
1963 	    if (error)
1964 		return FAIL;
1965 	}
1966 	if (evaluate)
1967 	{
1968 	    rettv->v_type = VAR_NUMBER;
1969 	    rettv->vval.v_number = result;
1970 	}
1971     }
1972 
1973     return OK;
1974 }
1975 
1976 /*
1977  * Handle third level expression:
1978  *	var1 == var2
1979  *	var1 =~ var2
1980  *	var1 != var2
1981  *	var1 !~ var2
1982  *	var1 > var2
1983  *	var1 >= var2
1984  *	var1 < var2
1985  *	var1 <= var2
1986  *	var1 is var2
1987  *	var1 isnot var2
1988  *
1989  * "arg" must point to the first non-white of the expression.
1990  * "arg" is advanced to the next non-white after the recognized expression.
1991  *
1992  * Return OK or FAIL.
1993  */
1994     static int
1995 eval4(char_u **arg, typval_T *rettv, int evaluate)
1996 {
1997     typval_T	var2;
1998     char_u	*p;
1999     int		i;
2000     exptype_T	type = TYPE_UNKNOWN;
2001     int		type_is = FALSE;    /* TRUE for "is" and "isnot" */
2002     int		len = 2;
2003     int		ic;
2004 
2005     /*
2006      * Get the first variable.
2007      */
2008     if (eval5(arg, rettv, evaluate) == FAIL)
2009 	return FAIL;
2010 
2011     p = *arg;
2012     switch (p[0])
2013     {
2014 	case '=':   if (p[1] == '=')
2015 			type = TYPE_EQUAL;
2016 		    else if (p[1] == '~')
2017 			type = TYPE_MATCH;
2018 		    break;
2019 	case '!':   if (p[1] == '=')
2020 			type = TYPE_NEQUAL;
2021 		    else if (p[1] == '~')
2022 			type = TYPE_NOMATCH;
2023 		    break;
2024 	case '>':   if (p[1] != '=')
2025 		    {
2026 			type = TYPE_GREATER;
2027 			len = 1;
2028 		    }
2029 		    else
2030 			type = TYPE_GEQUAL;
2031 		    break;
2032 	case '<':   if (p[1] != '=')
2033 		    {
2034 			type = TYPE_SMALLER;
2035 			len = 1;
2036 		    }
2037 		    else
2038 			type = TYPE_SEQUAL;
2039 		    break;
2040 	case 'i':   if (p[1] == 's')
2041 		    {
2042 			if (p[2] == 'n' && p[3] == 'o' && p[4] == 't')
2043 			    len = 5;
2044 			i = p[len];
2045 			if (!isalnum(i) && i != '_')
2046 			{
2047 			    type = len == 2 ? TYPE_EQUAL : TYPE_NEQUAL;
2048 			    type_is = TRUE;
2049 			}
2050 		    }
2051 		    break;
2052     }
2053 
2054     /*
2055      * If there is a comparative operator, use it.
2056      */
2057     if (type != TYPE_UNKNOWN)
2058     {
2059 	/* extra question mark appended: ignore case */
2060 	if (p[len] == '?')
2061 	{
2062 	    ic = TRUE;
2063 	    ++len;
2064 	}
2065 	/* extra '#' appended: match case */
2066 	else if (p[len] == '#')
2067 	{
2068 	    ic = FALSE;
2069 	    ++len;
2070 	}
2071 	/* nothing appended: use 'ignorecase' */
2072 	else
2073 	    ic = p_ic;
2074 
2075 	/*
2076 	 * Get the second variable.
2077 	 */
2078 	*arg = skipwhite(p + len);
2079 	if (eval5(arg, &var2, evaluate) == FAIL)
2080 	{
2081 	    clear_tv(rettv);
2082 	    return FAIL;
2083 	}
2084 	if (evaluate)
2085 	{
2086 	    int ret = typval_compare(rettv, &var2, type, type_is, ic);
2087 
2088 	    clear_tv(&var2);
2089 	    return ret;
2090 	}
2091     }
2092 
2093     return OK;
2094 }
2095 
2096 /*
2097  * Handle fourth level expression:
2098  *	+	number addition
2099  *	-	number subtraction
2100  *	.	string concatenation (if script version is 1)
2101  *	..	string concatenation
2102  *
2103  * "arg" must point to the first non-white of the expression.
2104  * "arg" is advanced to the next non-white after the recognized expression.
2105  *
2106  * Return OK or FAIL.
2107  */
2108     static int
2109 eval5(char_u **arg, typval_T *rettv, int evaluate)
2110 {
2111     typval_T	var2;
2112     typval_T	var3;
2113     int		op;
2114     varnumber_T	n1, n2;
2115 #ifdef FEAT_FLOAT
2116     float_T	f1 = 0, f2 = 0;
2117 #endif
2118     char_u	*s1, *s2;
2119     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
2120     char_u	*p;
2121     int		concat;
2122 
2123     /*
2124      * Get the first variable.
2125      */
2126     if (eval6(arg, rettv, evaluate, FALSE) == FAIL)
2127 	return FAIL;
2128 
2129     /*
2130      * Repeat computing, until no '+', '-' or '.' is following.
2131      */
2132     for (;;)
2133     {
2134 	// "." is only string concatenation when scriptversion is 1
2135 	op = **arg;
2136 	concat = op == '.'
2137 			&& (*(*arg + 1) == '.' || current_sctx.sc_version < 2);
2138 	if (op != '+' && op != '-' && !concat)
2139 	    break;
2140 
2141 	if ((op != '+' || (rettv->v_type != VAR_LIST
2142 						 && rettv->v_type != VAR_BLOB))
2143 #ifdef FEAT_FLOAT
2144 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2145 #endif
2146 		)
2147 	{
2148 	    /* For "list + ...", an illegal use of the first operand as
2149 	     * a number cannot be determined before evaluating the 2nd
2150 	     * operand: if this is also a list, all is ok.
2151 	     * For "something . ...", "something - ..." or "non-list + ...",
2152 	     * we know that the first operand needs to be a string or number
2153 	     * without evaluating the 2nd operand.  So check before to avoid
2154 	     * side effects after an error. */
2155 	    if (evaluate && tv_get_string_chk(rettv) == NULL)
2156 	    {
2157 		clear_tv(rettv);
2158 		return FAIL;
2159 	    }
2160 	}
2161 
2162 	/*
2163 	 * Get the second variable.
2164 	 */
2165 	if (op == '.' && *(*arg + 1) == '.')  // .. string concatenation
2166 	    ++*arg;
2167 	*arg = skipwhite(*arg + 1);
2168 	if (eval6(arg, &var2, evaluate, op == '.') == FAIL)
2169 	{
2170 	    clear_tv(rettv);
2171 	    return FAIL;
2172 	}
2173 
2174 	if (evaluate)
2175 	{
2176 	    /*
2177 	     * Compute the result.
2178 	     */
2179 	    if (op == '.')
2180 	    {
2181 		s1 = tv_get_string_buf(rettv, buf1);	/* already checked */
2182 		s2 = tv_get_string_buf_chk(&var2, buf2);
2183 		if (s2 == NULL)		/* type error ? */
2184 		{
2185 		    clear_tv(rettv);
2186 		    clear_tv(&var2);
2187 		    return FAIL;
2188 		}
2189 		p = concat_str(s1, s2);
2190 		clear_tv(rettv);
2191 		rettv->v_type = VAR_STRING;
2192 		rettv->vval.v_string = p;
2193 	    }
2194 	    else if (op == '+' && rettv->v_type == VAR_BLOB
2195 						   && var2.v_type == VAR_BLOB)
2196 	    {
2197 		blob_T  *b1 = rettv->vval.v_blob;
2198 		blob_T  *b2 = var2.vval.v_blob;
2199 		blob_T	*b = blob_alloc();
2200 		int	i;
2201 
2202 		if (b != NULL)
2203 		{
2204 		    for (i = 0; i < blob_len(b1); i++)
2205 			ga_append(&b->bv_ga, blob_get(b1, i));
2206 		    for (i = 0; i < blob_len(b2); i++)
2207 			ga_append(&b->bv_ga, blob_get(b2, i));
2208 
2209 		    clear_tv(rettv);
2210 		    rettv_blob_set(rettv, b);
2211 		}
2212 	    }
2213 	    else if (op == '+' && rettv->v_type == VAR_LIST
2214 						   && var2.v_type == VAR_LIST)
2215 	    {
2216 		/* concatenate Lists */
2217 		if (list_concat(rettv->vval.v_list, var2.vval.v_list,
2218 							       &var3) == FAIL)
2219 		{
2220 		    clear_tv(rettv);
2221 		    clear_tv(&var2);
2222 		    return FAIL;
2223 		}
2224 		clear_tv(rettv);
2225 		*rettv = var3;
2226 	    }
2227 	    else
2228 	    {
2229 		int	    error = FALSE;
2230 
2231 #ifdef FEAT_FLOAT
2232 		if (rettv->v_type == VAR_FLOAT)
2233 		{
2234 		    f1 = rettv->vval.v_float;
2235 		    n1 = 0;
2236 		}
2237 		else
2238 #endif
2239 		{
2240 		    n1 = tv_get_number_chk(rettv, &error);
2241 		    if (error)
2242 		    {
2243 			/* This can only happen for "list + non-list".  For
2244 			 * "non-list + ..." or "something - ...", we returned
2245 			 * before evaluating the 2nd operand. */
2246 			clear_tv(rettv);
2247 			return FAIL;
2248 		    }
2249 #ifdef FEAT_FLOAT
2250 		    if (var2.v_type == VAR_FLOAT)
2251 			f1 = n1;
2252 #endif
2253 		}
2254 #ifdef FEAT_FLOAT
2255 		if (var2.v_type == VAR_FLOAT)
2256 		{
2257 		    f2 = var2.vval.v_float;
2258 		    n2 = 0;
2259 		}
2260 		else
2261 #endif
2262 		{
2263 		    n2 = tv_get_number_chk(&var2, &error);
2264 		    if (error)
2265 		    {
2266 			clear_tv(rettv);
2267 			clear_tv(&var2);
2268 			return FAIL;
2269 		    }
2270 #ifdef FEAT_FLOAT
2271 		    if (rettv->v_type == VAR_FLOAT)
2272 			f2 = n2;
2273 #endif
2274 		}
2275 		clear_tv(rettv);
2276 
2277 #ifdef FEAT_FLOAT
2278 		/* If there is a float on either side the result is a float. */
2279 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
2280 		{
2281 		    if (op == '+')
2282 			f1 = f1 + f2;
2283 		    else
2284 			f1 = f1 - f2;
2285 		    rettv->v_type = VAR_FLOAT;
2286 		    rettv->vval.v_float = f1;
2287 		}
2288 		else
2289 #endif
2290 		{
2291 		    if (op == '+')
2292 			n1 = n1 + n2;
2293 		    else
2294 			n1 = n1 - n2;
2295 		    rettv->v_type = VAR_NUMBER;
2296 		    rettv->vval.v_number = n1;
2297 		}
2298 	    }
2299 	    clear_tv(&var2);
2300 	}
2301     }
2302     return OK;
2303 }
2304 
2305 /*
2306  * Handle fifth level expression:
2307  *	*	number multiplication
2308  *	/	number division
2309  *	%	number modulo
2310  *
2311  * "arg" must point to the first non-white of the expression.
2312  * "arg" is advanced to the next non-white after the recognized expression.
2313  *
2314  * Return OK or FAIL.
2315  */
2316     static int
2317 eval6(
2318     char_u	**arg,
2319     typval_T	*rettv,
2320     int		evaluate,
2321     int		want_string)  /* after "." operator */
2322 {
2323     typval_T	var2;
2324     int		op;
2325     varnumber_T	n1, n2;
2326 #ifdef FEAT_FLOAT
2327     int		use_float = FALSE;
2328     float_T	f1 = 0, f2 = 0;
2329 #endif
2330     int		error = FALSE;
2331 
2332     /*
2333      * Get the first variable.
2334      */
2335     if (eval7(arg, rettv, evaluate, want_string) == FAIL)
2336 	return FAIL;
2337 
2338     /*
2339      * Repeat computing, until no '*', '/' or '%' is following.
2340      */
2341     for (;;)
2342     {
2343 	op = **arg;
2344 	if (op != '*' && op != '/' && op != '%')
2345 	    break;
2346 
2347 	if (evaluate)
2348 	{
2349 #ifdef FEAT_FLOAT
2350 	    if (rettv->v_type == VAR_FLOAT)
2351 	    {
2352 		f1 = rettv->vval.v_float;
2353 		use_float = TRUE;
2354 		n1 = 0;
2355 	    }
2356 	    else
2357 #endif
2358 		n1 = tv_get_number_chk(rettv, &error);
2359 	    clear_tv(rettv);
2360 	    if (error)
2361 		return FAIL;
2362 	}
2363 	else
2364 	    n1 = 0;
2365 
2366 	/*
2367 	 * Get the second variable.
2368 	 */
2369 	*arg = skipwhite(*arg + 1);
2370 	if (eval7(arg, &var2, evaluate, FALSE) == FAIL)
2371 	    return FAIL;
2372 
2373 	if (evaluate)
2374 	{
2375 #ifdef FEAT_FLOAT
2376 	    if (var2.v_type == VAR_FLOAT)
2377 	    {
2378 		if (!use_float)
2379 		{
2380 		    f1 = n1;
2381 		    use_float = TRUE;
2382 		}
2383 		f2 = var2.vval.v_float;
2384 		n2 = 0;
2385 	    }
2386 	    else
2387 #endif
2388 	    {
2389 		n2 = tv_get_number_chk(&var2, &error);
2390 		clear_tv(&var2);
2391 		if (error)
2392 		    return FAIL;
2393 #ifdef FEAT_FLOAT
2394 		if (use_float)
2395 		    f2 = n2;
2396 #endif
2397 	    }
2398 
2399 	    /*
2400 	     * Compute the result.
2401 	     * When either side is a float the result is a float.
2402 	     */
2403 #ifdef FEAT_FLOAT
2404 	    if (use_float)
2405 	    {
2406 		if (op == '*')
2407 		    f1 = f1 * f2;
2408 		else if (op == '/')
2409 		{
2410 # ifdef VMS
2411 		    /* VMS crashes on divide by zero, work around it */
2412 		    if (f2 == 0.0)
2413 		    {
2414 			if (f1 == 0)
2415 			    f1 = -1 * __F_FLT_MAX - 1L;   /* similar to NaN */
2416 			else if (f1 < 0)
2417 			    f1 = -1 * __F_FLT_MAX;
2418 			else
2419 			    f1 = __F_FLT_MAX;
2420 		    }
2421 		    else
2422 			f1 = f1 / f2;
2423 # else
2424 		    /* We rely on the floating point library to handle divide
2425 		     * by zero to result in "inf" and not a crash. */
2426 		    f1 = f1 / f2;
2427 # endif
2428 		}
2429 		else
2430 		{
2431 		    emsg(_("E804: Cannot use '%' with Float"));
2432 		    return FAIL;
2433 		}
2434 		rettv->v_type = VAR_FLOAT;
2435 		rettv->vval.v_float = f1;
2436 	    }
2437 	    else
2438 #endif
2439 	    {
2440 		if (op == '*')
2441 		    n1 = n1 * n2;
2442 		else if (op == '/')
2443 		    n1 = num_divide(n1, n2);
2444 		else
2445 		    n1 = num_modulus(n1, n2);
2446 
2447 		rettv->v_type = VAR_NUMBER;
2448 		rettv->vval.v_number = n1;
2449 	    }
2450 	}
2451     }
2452 
2453     return OK;
2454 }
2455 
2456 /*
2457  * Handle sixth level expression:
2458  *  number		number constant
2459  *  0zFFFFFFFF		Blob constant
2460  *  "string"		string constant
2461  *  'string'		literal string constant
2462  *  &option-name	option value
2463  *  @r			register contents
2464  *  identifier		variable value
2465  *  function()		function call
2466  *  $VAR		environment variable
2467  *  (expression)	nested expression
2468  *  [expr, expr]	List
2469  *  {key: val, key: val}   Dictionary
2470  *  #{key: val, key: val}  Dictionary with literal keys
2471  *
2472  *  Also handle:
2473  *  ! in front		logical NOT
2474  *  - in front		unary minus
2475  *  + in front		unary plus (ignored)
2476  *  trailing []		subscript in String or List
2477  *  trailing .name	entry in Dictionary
2478  *  trailing ->name()	method call
2479  *
2480  * "arg" must point to the first non-white of the expression.
2481  * "arg" is advanced to the next non-white after the recognized expression.
2482  *
2483  * Return OK or FAIL.
2484  */
2485     static int
2486 eval7(
2487     char_u	**arg,
2488     typval_T	*rettv,
2489     int		evaluate,
2490     int		want_string UNUSED)	/* after "." operator */
2491 {
2492     varnumber_T	n;
2493     int		len;
2494     char_u	*s;
2495     char_u	*start_leader, *end_leader;
2496     int		ret = OK;
2497     char_u	*alias;
2498 
2499     /*
2500      * Initialise variable so that clear_tv() can't mistake this for a
2501      * string and free a string that isn't there.
2502      */
2503     rettv->v_type = VAR_UNKNOWN;
2504 
2505     /*
2506      * Skip '!', '-' and '+' characters.  They are handled later.
2507      */
2508     start_leader = *arg;
2509     while (**arg == '!' || **arg == '-' || **arg == '+')
2510 	*arg = skipwhite(*arg + 1);
2511     end_leader = *arg;
2512 
2513     if (**arg == '.' && (!isdigit(*(*arg + 1))
2514 #ifdef FEAT_FLOAT
2515 	    || current_sctx.sc_version < 2
2516 #endif
2517 	    ))
2518     {
2519 	semsg(_(e_invexpr2), *arg);
2520 	++*arg;
2521 	return FAIL;
2522     }
2523 
2524     switch (**arg)
2525     {
2526     /*
2527      * Number constant.
2528      */
2529     case '0':
2530     case '1':
2531     case '2':
2532     case '3':
2533     case '4':
2534     case '5':
2535     case '6':
2536     case '7':
2537     case '8':
2538     case '9':
2539     case '.':
2540 	{
2541 #ifdef FEAT_FLOAT
2542 		char_u *p;
2543 		int    get_float = FALSE;
2544 
2545 		/* We accept a float when the format matches
2546 		 * "[0-9]\+\.[0-9]\+\([eE][+-]\?[0-9]\+\)\?".  This is very
2547 		 * strict to avoid backwards compatibility problems.
2548 		 * With script version 2 and later the leading digit can be
2549 		 * omitted.
2550 		 * Don't look for a float after the "." operator, so that
2551 		 * ":let vers = 1.2.3" doesn't fail. */
2552 		if (**arg == '.')
2553 		    p = *arg;
2554 		else
2555 		    p = skipdigits(*arg + 1);
2556 		if (!want_string && p[0] == '.' && vim_isdigit(p[1]))
2557 		{
2558 		    get_float = TRUE;
2559 		    p = skipdigits(p + 2);
2560 		    if (*p == 'e' || *p == 'E')
2561 		    {
2562 			++p;
2563 			if (*p == '-' || *p == '+')
2564 			    ++p;
2565 			if (!vim_isdigit(*p))
2566 			    get_float = FALSE;
2567 			else
2568 			    p = skipdigits(p + 1);
2569 		    }
2570 		    if (ASCII_ISALPHA(*p) || *p == '.')
2571 			get_float = FALSE;
2572 		}
2573 		if (get_float)
2574 		{
2575 		    float_T	f;
2576 
2577 		    *arg += string2float(*arg, &f);
2578 		    if (evaluate)
2579 		    {
2580 			rettv->v_type = VAR_FLOAT;
2581 			rettv->vval.v_float = f;
2582 		    }
2583 		}
2584 		else
2585 #endif
2586 		if (**arg == '0' && ((*arg)[1] == 'z' || (*arg)[1] == 'Z'))
2587 		{
2588 		    char_u  *bp;
2589 		    blob_T  *blob = NULL;  // init for gcc
2590 
2591 		    // Blob constant: 0z0123456789abcdef
2592 		    if (evaluate)
2593 			blob = blob_alloc();
2594 		    for (bp = *arg + 2; vim_isxdigit(bp[0]); bp += 2)
2595 		    {
2596 			if (!vim_isxdigit(bp[1]))
2597 			{
2598 			    if (blob != NULL)
2599 			    {
2600 				emsg(_("E973: Blob literal should have an even number of hex characters"));
2601 				ga_clear(&blob->bv_ga);
2602 				VIM_CLEAR(blob);
2603 			    }
2604 			    ret = FAIL;
2605 			    break;
2606 			}
2607 			if (blob != NULL)
2608 			    ga_append(&blob->bv_ga,
2609 					 (hex2nr(*bp) << 4) + hex2nr(*(bp+1)));
2610 			if (bp[2] == '.' && vim_isxdigit(bp[3]))
2611 			    ++bp;
2612 		    }
2613 		    if (blob != NULL)
2614 			rettv_blob_set(rettv, blob);
2615 		    *arg = bp;
2616 		}
2617 		else
2618 		{
2619 		    // decimal, hex or octal number
2620 		    vim_str2nr(*arg, NULL, &len, current_sctx.sc_version >= 4
2621 				  ? STR2NR_NO_OCT + STR2NR_QUOTE
2622 				  : STR2NR_ALL, &n, NULL, 0, TRUE);
2623 		    if (len == 0)
2624 		    {
2625 			semsg(_(e_invexpr2), *arg);
2626 			ret = FAIL;
2627 			break;
2628 		    }
2629 		    *arg += len;
2630 		    if (evaluate)
2631 		    {
2632 			rettv->v_type = VAR_NUMBER;
2633 			rettv->vval.v_number = n;
2634 		    }
2635 		}
2636 		break;
2637 	}
2638 
2639     /*
2640      * String constant: "string".
2641      */
2642     case '"':	ret = get_string_tv(arg, rettv, evaluate);
2643 		break;
2644 
2645     /*
2646      * Literal string constant: 'str''ing'.
2647      */
2648     case '\'':	ret = get_lit_string_tv(arg, rettv, evaluate);
2649 		break;
2650 
2651     /*
2652      * List: [expr, expr]
2653      */
2654     case '[':	ret = get_list_tv(arg, rettv, evaluate);
2655 		break;
2656 
2657     /*
2658      * Dictionary: #{key: val, key: val}
2659      */
2660     case '#':	if ((*arg)[1] == '{')
2661 		{
2662 		    ++*arg;
2663 		    ret = dict_get_tv(arg, rettv, evaluate, TRUE);
2664 		}
2665 		else
2666 		    ret = NOTDONE;
2667 		break;
2668 
2669     /*
2670      * Lambda: {arg, arg -> expr}
2671      * Dictionary: {'key': val, 'key': val}
2672      */
2673     case '{':	ret = get_lambda_tv(arg, rettv, evaluate);
2674 		if (ret == NOTDONE)
2675 		    ret = dict_get_tv(arg, rettv, evaluate, FALSE);
2676 		break;
2677 
2678     /*
2679      * Option value: &name
2680      */
2681     case '&':	ret = get_option_tv(arg, rettv, evaluate);
2682 		break;
2683 
2684     /*
2685      * Environment variable: $VAR.
2686      */
2687     case '$':	ret = get_env_tv(arg, rettv, evaluate);
2688 		break;
2689 
2690     /*
2691      * Register contents: @r.
2692      */
2693     case '@':	++*arg;
2694 		if (evaluate)
2695 		{
2696 		    rettv->v_type = VAR_STRING;
2697 		    rettv->vval.v_string = get_reg_contents(**arg,
2698 							    GREG_EXPR_SRC);
2699 		}
2700 		if (**arg != NUL)
2701 		    ++*arg;
2702 		break;
2703 
2704     /*
2705      * nested expression: (expression).
2706      */
2707     case '(':	*arg = skipwhite(*arg + 1);
2708 		ret = eval1(arg, rettv, evaluate);	/* recursive! */
2709 		if (**arg == ')')
2710 		    ++*arg;
2711 		else if (ret == OK)
2712 		{
2713 		    emsg(_("E110: Missing ')'"));
2714 		    clear_tv(rettv);
2715 		    ret = FAIL;
2716 		}
2717 		break;
2718 
2719     default:	ret = NOTDONE;
2720 		break;
2721     }
2722 
2723     if (ret == NOTDONE)
2724     {
2725 	/*
2726 	 * Must be a variable or function name.
2727 	 * Can also be a curly-braces kind of name: {expr}.
2728 	 */
2729 	s = *arg;
2730 	len = get_name_len(arg, &alias, evaluate, TRUE);
2731 	if (alias != NULL)
2732 	    s = alias;
2733 
2734 	if (len <= 0)
2735 	    ret = FAIL;
2736 	else
2737 	{
2738 	    if (**arg == '(')		/* recursive! */
2739 		ret = eval_func(arg, s, len, rettv, evaluate, NULL);
2740 	    else if (evaluate)
2741 		ret = get_var_tv(s, len, rettv, NULL, TRUE, FALSE);
2742 	    else
2743 	    {
2744 		check_vars(s, len);
2745 		ret = OK;
2746 	    }
2747 	}
2748 	vim_free(alias);
2749     }
2750 
2751     *arg = skipwhite(*arg);
2752 
2753     /* Handle following '[', '(' and '.' for expr[expr], expr.name,
2754      * expr(expr), expr->name(expr) */
2755     if (ret == OK)
2756 	ret = handle_subscript(arg, rettv, evaluate, TRUE,
2757 						    start_leader, &end_leader);
2758 
2759     /*
2760      * Apply logical NOT and unary '-', from right to left, ignore '+'.
2761      */
2762     if (ret == OK && evaluate && end_leader > start_leader)
2763 	ret = eval7_leader(rettv, start_leader, &end_leader);
2764     return ret;
2765 }
2766 
2767 /*
2768  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
2769  * Adjusts "end_leaderp" until it is at "start_leader".
2770  */
2771     static int
2772 eval7_leader(typval_T *rettv, char_u *start_leader, char_u **end_leaderp)
2773 {
2774     char_u	*end_leader = *end_leaderp;
2775     int		ret = OK;
2776     int		error = FALSE;
2777     varnumber_T val = 0;
2778 #ifdef FEAT_FLOAT
2779     float_T	    f = 0.0;
2780 
2781     if (rettv->v_type == VAR_FLOAT)
2782 	f = rettv->vval.v_float;
2783     else
2784 #endif
2785 	val = tv_get_number_chk(rettv, &error);
2786     if (error)
2787     {
2788 	clear_tv(rettv);
2789 	ret = FAIL;
2790     }
2791     else
2792     {
2793 	while (end_leader > start_leader)
2794 	{
2795 	    --end_leader;
2796 	    if (*end_leader == '!')
2797 	    {
2798 #ifdef FEAT_FLOAT
2799 		if (rettv->v_type == VAR_FLOAT)
2800 		    f = !f;
2801 		else
2802 #endif
2803 		    val = !val;
2804 	    }
2805 	    else if (*end_leader == '-')
2806 	    {
2807 #ifdef FEAT_FLOAT
2808 		if (rettv->v_type == VAR_FLOAT)
2809 		    f = -f;
2810 		else
2811 #endif
2812 		    val = -val;
2813 	    }
2814 	}
2815 #ifdef FEAT_FLOAT
2816 	if (rettv->v_type == VAR_FLOAT)
2817 	{
2818 	    clear_tv(rettv);
2819 	    rettv->vval.v_float = f;
2820 	}
2821 	else
2822 #endif
2823 	{
2824 	    clear_tv(rettv);
2825 	    rettv->v_type = VAR_NUMBER;
2826 	    rettv->vval.v_number = val;
2827 	}
2828     }
2829     *end_leaderp = end_leader;
2830     return ret;
2831 }
2832 
2833 /*
2834  * Call the function referred to in "rettv".
2835  */
2836     static int
2837 call_func_rettv(
2838 	char_u	    **arg,
2839 	typval_T    *rettv,
2840 	int	    evaluate,
2841 	dict_T	    *selfdict,
2842 	typval_T    *basetv)
2843 {
2844     partial_T	*pt = NULL;
2845     funcexe_T	funcexe;
2846     typval_T	functv;
2847     char_u	*s;
2848     int		ret;
2849 
2850     // need to copy the funcref so that we can clear rettv
2851     if (evaluate)
2852     {
2853 	functv = *rettv;
2854 	rettv->v_type = VAR_UNKNOWN;
2855 
2856 	/* Invoke the function.  Recursive! */
2857 	if (functv.v_type == VAR_PARTIAL)
2858 	{
2859 	    pt = functv.vval.v_partial;
2860 	    s = partial_name(pt);
2861 	}
2862 	else
2863 	    s = functv.vval.v_string;
2864     }
2865     else
2866 	s = (char_u *)"";
2867 
2868     vim_memset(&funcexe, 0, sizeof(funcexe));
2869     funcexe.firstline = curwin->w_cursor.lnum;
2870     funcexe.lastline = curwin->w_cursor.lnum;
2871     funcexe.evaluate = evaluate;
2872     funcexe.partial = pt;
2873     funcexe.selfdict = selfdict;
2874     funcexe.basetv = basetv;
2875     ret = get_func_tv(s, -1, rettv, arg, &funcexe);
2876 
2877     /* Clear the funcref afterwards, so that deleting it while
2878      * evaluating the arguments is possible (see test55). */
2879     if (evaluate)
2880 	clear_tv(&functv);
2881 
2882     return ret;
2883 }
2884 
2885 /*
2886  * Evaluate "->method()".
2887  * "*arg" points to the '-'.
2888  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
2889  */
2890     static int
2891 eval_lambda(
2892     char_u	**arg,
2893     typval_T	*rettv,
2894     int		evaluate,
2895     int		verbose)	/* give error messages */
2896 {
2897     typval_T	base = *rettv;
2898     int		ret;
2899 
2900     // Skip over the ->.
2901     *arg += 2;
2902     rettv->v_type = VAR_UNKNOWN;
2903 
2904     ret = get_lambda_tv(arg, rettv, evaluate);
2905     if (ret == NOTDONE)
2906 	return FAIL;
2907     else if (**arg != '(')
2908     {
2909 	if (verbose)
2910 	{
2911 	    if (*skipwhite(*arg) == '(')
2912 		semsg(_(e_nowhitespace));
2913 	    else
2914 		semsg(_(e_missingparen), "lambda");
2915 	}
2916 	clear_tv(rettv);
2917 	return FAIL;
2918     }
2919     return call_func_rettv(arg, rettv, evaluate, NULL, &base);
2920 }
2921 
2922 /*
2923  * Evaluate "->method()".
2924  * "*arg" points to the '-'.
2925  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
2926  */
2927     static int
2928 eval_method(
2929     char_u	**arg,
2930     typval_T	*rettv,
2931     int		evaluate,
2932     int		verbose)	/* give error messages */
2933 {
2934     char_u	*name;
2935     long	len;
2936     char_u	*alias;
2937     typval_T	base = *rettv;
2938     int		ret;
2939 
2940     // Skip over the ->.
2941     *arg += 2;
2942     rettv->v_type = VAR_UNKNOWN;
2943 
2944     name = *arg;
2945     len = get_name_len(arg, &alias, evaluate, TRUE);
2946     if (alias != NULL)
2947 	name = alias;
2948 
2949     if (len <= 0)
2950     {
2951 	if (verbose)
2952 	    emsg(_("E260: Missing name after ->"));
2953 	ret = FAIL;
2954     }
2955     else
2956     {
2957 	if (**arg != '(')
2958 	{
2959 	    if (verbose)
2960 		semsg(_(e_missingparen), name);
2961 	    ret = FAIL;
2962 	}
2963 	else if (VIM_ISWHITE((*arg)[-1]))
2964 	{
2965 	    if (verbose)
2966 		semsg(_(e_nowhitespace));
2967 	    ret = FAIL;
2968 	}
2969 	else
2970 	    ret = eval_func(arg, name, len, rettv, evaluate, &base);
2971     }
2972 
2973     // Clear the funcref afterwards, so that deleting it while
2974     // evaluating the arguments is possible (see test55).
2975     if (evaluate)
2976 	clear_tv(&base);
2977 
2978     return ret;
2979 }
2980 
2981 /*
2982  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
2983  * "*arg" points to the '[' or '.'.
2984  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
2985  */
2986     static int
2987 eval_index(
2988     char_u	**arg,
2989     typval_T	*rettv,
2990     int		evaluate,
2991     int		verbose)	/* give error messages */
2992 {
2993     int		empty1 = FALSE, empty2 = FALSE;
2994     typval_T	var1, var2;
2995     long	i;
2996     long	n1, n2 = 0;
2997     long	len = -1;
2998     int		range = FALSE;
2999     char_u	*s;
3000     char_u	*key = NULL;
3001 
3002     switch (rettv->v_type)
3003     {
3004 	case VAR_FUNC:
3005 	case VAR_PARTIAL:
3006 	    if (verbose)
3007 		emsg(_("E695: Cannot index a Funcref"));
3008 	    return FAIL;
3009 	case VAR_FLOAT:
3010 #ifdef FEAT_FLOAT
3011 	    if (verbose)
3012 		emsg(_(e_float_as_string));
3013 	    return FAIL;
3014 #endif
3015 	case VAR_SPECIAL:
3016 	case VAR_JOB:
3017 	case VAR_CHANNEL:
3018 	    if (verbose)
3019 		emsg(_("E909: Cannot index a special variable"));
3020 	    return FAIL;
3021 	case VAR_UNKNOWN:
3022 	    if (evaluate)
3023 		return FAIL;
3024 	    /* FALLTHROUGH */
3025 
3026 	case VAR_STRING:
3027 	case VAR_NUMBER:
3028 	case VAR_LIST:
3029 	case VAR_DICT:
3030 	case VAR_BLOB:
3031 	    break;
3032     }
3033 
3034     init_tv(&var1);
3035     init_tv(&var2);
3036     if (**arg == '.')
3037     {
3038 	/*
3039 	 * dict.name
3040 	 */
3041 	key = *arg + 1;
3042 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
3043 	    ;
3044 	if (len == 0)
3045 	    return FAIL;
3046 	*arg = skipwhite(key + len);
3047     }
3048     else
3049     {
3050 	/*
3051 	 * something[idx]
3052 	 *
3053 	 * Get the (first) variable from inside the [].
3054 	 */
3055 	*arg = skipwhite(*arg + 1);
3056 	if (**arg == ':')
3057 	    empty1 = TRUE;
3058 	else if (eval1(arg, &var1, evaluate) == FAIL)	/* recursive! */
3059 	    return FAIL;
3060 	else if (evaluate && tv_get_string_chk(&var1) == NULL)
3061 	{
3062 	    /* not a number or string */
3063 	    clear_tv(&var1);
3064 	    return FAIL;
3065 	}
3066 
3067 	/*
3068 	 * Get the second variable from inside the [:].
3069 	 */
3070 	if (**arg == ':')
3071 	{
3072 	    range = TRUE;
3073 	    *arg = skipwhite(*arg + 1);
3074 	    if (**arg == ']')
3075 		empty2 = TRUE;
3076 	    else if (eval1(arg, &var2, evaluate) == FAIL)	/* recursive! */
3077 	    {
3078 		if (!empty1)
3079 		    clear_tv(&var1);
3080 		return FAIL;
3081 	    }
3082 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
3083 	    {
3084 		/* not a number or string */
3085 		if (!empty1)
3086 		    clear_tv(&var1);
3087 		clear_tv(&var2);
3088 		return FAIL;
3089 	    }
3090 	}
3091 
3092 	/* Check for the ']'. */
3093 	if (**arg != ']')
3094 	{
3095 	    if (verbose)
3096 		emsg(_(e_missbrac));
3097 	    clear_tv(&var1);
3098 	    if (range)
3099 		clear_tv(&var2);
3100 	    return FAIL;
3101 	}
3102 	*arg = skipwhite(*arg + 1);	/* skip the ']' */
3103     }
3104 
3105     if (evaluate)
3106     {
3107 	n1 = 0;
3108 	if (!empty1 && rettv->v_type != VAR_DICT)
3109 	{
3110 	    n1 = tv_get_number(&var1);
3111 	    clear_tv(&var1);
3112 	}
3113 	if (range)
3114 	{
3115 	    if (empty2)
3116 		n2 = -1;
3117 	    else
3118 	    {
3119 		n2 = tv_get_number(&var2);
3120 		clear_tv(&var2);
3121 	    }
3122 	}
3123 
3124 	switch (rettv->v_type)
3125 	{
3126 	    case VAR_UNKNOWN:
3127 	    case VAR_FUNC:
3128 	    case VAR_PARTIAL:
3129 	    case VAR_FLOAT:
3130 	    case VAR_SPECIAL:
3131 	    case VAR_JOB:
3132 	    case VAR_CHANNEL:
3133 		break; /* not evaluating, skipping over subscript */
3134 
3135 	    case VAR_NUMBER:
3136 	    case VAR_STRING:
3137 		s = tv_get_string(rettv);
3138 		len = (long)STRLEN(s);
3139 		if (range)
3140 		{
3141 		    /* The resulting variable is a substring.  If the indexes
3142 		     * are out of range the result is empty. */
3143 		    if (n1 < 0)
3144 		    {
3145 			n1 = len + n1;
3146 			if (n1 < 0)
3147 			    n1 = 0;
3148 		    }
3149 		    if (n2 < 0)
3150 			n2 = len + n2;
3151 		    else if (n2 >= len)
3152 			n2 = len;
3153 		    if (n1 >= len || n2 < 0 || n1 > n2)
3154 			s = NULL;
3155 		    else
3156 			s = vim_strnsave(s + n1, (int)(n2 - n1 + 1));
3157 		}
3158 		else
3159 		{
3160 		    /* The resulting variable is a string of a single
3161 		     * character.  If the index is too big or negative the
3162 		     * result is empty. */
3163 		    if (n1 >= len || n1 < 0)
3164 			s = NULL;
3165 		    else
3166 			s = vim_strnsave(s + n1, 1);
3167 		}
3168 		clear_tv(rettv);
3169 		rettv->v_type = VAR_STRING;
3170 		rettv->vval.v_string = s;
3171 		break;
3172 
3173 	    case VAR_BLOB:
3174 		len = blob_len(rettv->vval.v_blob);
3175 		if (range)
3176 		{
3177 		    // The resulting variable is a sub-blob.  If the indexes
3178 		    // are out of range the result is empty.
3179 		    if (n1 < 0)
3180 		    {
3181 			n1 = len + n1;
3182 			if (n1 < 0)
3183 			    n1 = 0;
3184 		    }
3185 		    if (n2 < 0)
3186 			n2 = len + n2;
3187 		    else if (n2 >= len)
3188 			n2 = len - 1;
3189 		    if (n1 >= len || n2 < 0 || n1 > n2)
3190 		    {
3191 			clear_tv(rettv);
3192 			rettv->v_type = VAR_BLOB;
3193 			rettv->vval.v_blob = NULL;
3194 		    }
3195 		    else
3196 		    {
3197 			blob_T  *blob = blob_alloc();
3198 
3199 			if (blob != NULL)
3200 			{
3201 			    if (ga_grow(&blob->bv_ga, n2 - n1 + 1) == FAIL)
3202 			    {
3203 				blob_free(blob);
3204 				return FAIL;
3205 			    }
3206 			    blob->bv_ga.ga_len = n2 - n1 + 1;
3207 			    for (i = n1; i <= n2; i++)
3208 				blob_set(blob, i - n1,
3209 					      blob_get(rettv->vval.v_blob, i));
3210 
3211 			    clear_tv(rettv);
3212 			    rettv_blob_set(rettv, blob);
3213 			}
3214 		    }
3215 		}
3216 		else
3217 		{
3218 		    // The resulting variable is a byte value.
3219 		    // If the index is too big or negative that is an error.
3220 		    if (n1 < 0)
3221 			n1 = len + n1;
3222 		    if (n1 < len && n1 >= 0)
3223 		    {
3224 			int v = blob_get(rettv->vval.v_blob, n1);
3225 
3226 			clear_tv(rettv);
3227 			rettv->v_type = VAR_NUMBER;
3228 			rettv->vval.v_number = v;
3229 		    }
3230 		    else
3231 			semsg(_(e_blobidx), n1);
3232 		}
3233 		break;
3234 
3235 	    case VAR_LIST:
3236 		len = list_len(rettv->vval.v_list);
3237 		if (n1 < 0)
3238 		    n1 = len + n1;
3239 		if (!empty1 && (n1 < 0 || n1 >= len))
3240 		{
3241 		    /* For a range we allow invalid values and return an empty
3242 		     * list.  A list index out of range is an error. */
3243 		    if (!range)
3244 		    {
3245 			if (verbose)
3246 			    semsg(_(e_listidx), n1);
3247 			return FAIL;
3248 		    }
3249 		    n1 = len;
3250 		}
3251 		if (range)
3252 		{
3253 		    list_T	*l;
3254 		    listitem_T	*item;
3255 
3256 		    if (n2 < 0)
3257 			n2 = len + n2;
3258 		    else if (n2 >= len)
3259 			n2 = len - 1;
3260 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
3261 			n2 = -1;
3262 		    l = list_alloc();
3263 		    if (l == NULL)
3264 			return FAIL;
3265 		    for (item = list_find(rettv->vval.v_list, n1);
3266 							       n1 <= n2; ++n1)
3267 		    {
3268 			if (list_append_tv(l, &item->li_tv) == FAIL)
3269 			{
3270 			    list_free(l);
3271 			    return FAIL;
3272 			}
3273 			item = item->li_next;
3274 		    }
3275 		    clear_tv(rettv);
3276 		    rettv_list_set(rettv, l);
3277 		}
3278 		else
3279 		{
3280 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
3281 		    clear_tv(rettv);
3282 		    *rettv = var1;
3283 		}
3284 		break;
3285 
3286 	    case VAR_DICT:
3287 		if (range)
3288 		{
3289 		    if (verbose)
3290 			emsg(_(e_dictrange));
3291 		    if (len == -1)
3292 			clear_tv(&var1);
3293 		    return FAIL;
3294 		}
3295 		{
3296 		    dictitem_T	*item;
3297 
3298 		    if (len == -1)
3299 		    {
3300 			key = tv_get_string_chk(&var1);
3301 			if (key == NULL)
3302 			{
3303 			    clear_tv(&var1);
3304 			    return FAIL;
3305 			}
3306 		    }
3307 
3308 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
3309 
3310 		    if (item == NULL && verbose)
3311 			semsg(_(e_dictkey), key);
3312 		    if (len == -1)
3313 			clear_tv(&var1);
3314 		    if (item == NULL)
3315 			return FAIL;
3316 
3317 		    copy_tv(&item->di_tv, &var1);
3318 		    clear_tv(rettv);
3319 		    *rettv = var1;
3320 		}
3321 		break;
3322 	}
3323     }
3324 
3325     return OK;
3326 }
3327 
3328 /*
3329  * Get an option value.
3330  * "arg" points to the '&' or '+' before the option name.
3331  * "arg" is advanced to character after the option name.
3332  * Return OK or FAIL.
3333  */
3334     int
3335 get_option_tv(
3336     char_u	**arg,
3337     typval_T	*rettv,	/* when NULL, only check if option exists */
3338     int		evaluate)
3339 {
3340     char_u	*option_end;
3341     long	numval;
3342     char_u	*stringval;
3343     int		opt_type;
3344     int		c;
3345     int		working = (**arg == '+');    /* has("+option") */
3346     int		ret = OK;
3347     int		opt_flags;
3348 
3349     /*
3350      * Isolate the option name and find its value.
3351      */
3352     option_end = find_option_end(arg, &opt_flags);
3353     if (option_end == NULL)
3354     {
3355 	if (rettv != NULL)
3356 	    semsg(_("E112: Option name missing: %s"), *arg);
3357 	return FAIL;
3358     }
3359 
3360     if (!evaluate)
3361     {
3362 	*arg = option_end;
3363 	return OK;
3364     }
3365 
3366     c = *option_end;
3367     *option_end = NUL;
3368     opt_type = get_option_value(*arg, &numval,
3369 			       rettv == NULL ? NULL : &stringval, opt_flags);
3370 
3371     if (opt_type == -3)			/* invalid name */
3372     {
3373 	if (rettv != NULL)
3374 	    semsg(_("E113: Unknown option: %s"), *arg);
3375 	ret = FAIL;
3376     }
3377     else if (rettv != NULL)
3378     {
3379 	if (opt_type == -2)		/* hidden string option */
3380 	{
3381 	    rettv->v_type = VAR_STRING;
3382 	    rettv->vval.v_string = NULL;
3383 	}
3384 	else if (opt_type == -1)	/* hidden number option */
3385 	{
3386 	    rettv->v_type = VAR_NUMBER;
3387 	    rettv->vval.v_number = 0;
3388 	}
3389 	else if (opt_type == 1)		/* number option */
3390 	{
3391 	    rettv->v_type = VAR_NUMBER;
3392 	    rettv->vval.v_number = numval;
3393 	}
3394 	else				/* string option */
3395 	{
3396 	    rettv->v_type = VAR_STRING;
3397 	    rettv->vval.v_string = stringval;
3398 	}
3399     }
3400     else if (working && (opt_type == -2 || opt_type == -1))
3401 	ret = FAIL;
3402 
3403     *option_end = c;		    /* put back for error messages */
3404     *arg = option_end;
3405 
3406     return ret;
3407 }
3408 
3409 /*
3410  * Allocate a variable for a string constant.
3411  * Return OK or FAIL.
3412  */
3413     static int
3414 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
3415 {
3416     char_u	*p;
3417     char_u	*name;
3418     int		extra = 0;
3419 
3420     /*
3421      * Find the end of the string, skipping backslashed characters.
3422      */
3423     for (p = *arg + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
3424     {
3425 	if (*p == '\\' && p[1] != NUL)
3426 	{
3427 	    ++p;
3428 	    /* A "\<x>" form occupies at least 4 characters, and produces up
3429 	     * to 6 characters: reserve space for 2 extra */
3430 	    if (*p == '<')
3431 		extra += 2;
3432 	}
3433     }
3434 
3435     if (*p != '"')
3436     {
3437 	semsg(_("E114: Missing quote: %s"), *arg);
3438 	return FAIL;
3439     }
3440 
3441     /* If only parsing, set *arg and return here */
3442     if (!evaluate)
3443     {
3444 	*arg = p + 1;
3445 	return OK;
3446     }
3447 
3448     /*
3449      * Copy the string into allocated memory, handling backslashed
3450      * characters.
3451      */
3452     name = alloc(p - *arg + extra);
3453     if (name == NULL)
3454 	return FAIL;
3455     rettv->v_type = VAR_STRING;
3456     rettv->vval.v_string = name;
3457 
3458     for (p = *arg + 1; *p != NUL && *p != '"'; )
3459     {
3460 	if (*p == '\\')
3461 	{
3462 	    switch (*++p)
3463 	    {
3464 		case 'b': *name++ = BS; ++p; break;
3465 		case 'e': *name++ = ESC; ++p; break;
3466 		case 'f': *name++ = FF; ++p; break;
3467 		case 'n': *name++ = NL; ++p; break;
3468 		case 'r': *name++ = CAR; ++p; break;
3469 		case 't': *name++ = TAB; ++p; break;
3470 
3471 		case 'X': /* hex: "\x1", "\x12" */
3472 		case 'x':
3473 		case 'u': /* Unicode: "\u0023" */
3474 		case 'U':
3475 			  if (vim_isxdigit(p[1]))
3476 			  {
3477 			      int	n, nr;
3478 			      int	c = toupper(*p);
3479 
3480 			      if (c == 'X')
3481 				  n = 2;
3482 			      else if (*p == 'u')
3483 				  n = 4;
3484 			      else
3485 				  n = 8;
3486 			      nr = 0;
3487 			      while (--n >= 0 && vim_isxdigit(p[1]))
3488 			      {
3489 				  ++p;
3490 				  nr = (nr << 4) + hex2nr(*p);
3491 			      }
3492 			      ++p;
3493 			      /* For "\u" store the number according to
3494 			       * 'encoding'. */
3495 			      if (c != 'X')
3496 				  name += (*mb_char2bytes)(nr, name);
3497 			      else
3498 				  *name++ = nr;
3499 			  }
3500 			  break;
3501 
3502 			  /* octal: "\1", "\12", "\123" */
3503 		case '0':
3504 		case '1':
3505 		case '2':
3506 		case '3':
3507 		case '4':
3508 		case '5':
3509 		case '6':
3510 		case '7': *name = *p++ - '0';
3511 			  if (*p >= '0' && *p <= '7')
3512 			  {
3513 			      *name = (*name << 3) + *p++ - '0';
3514 			      if (*p >= '0' && *p <= '7')
3515 				  *name = (*name << 3) + *p++ - '0';
3516 			  }
3517 			  ++name;
3518 			  break;
3519 
3520 			    /* Special key, e.g.: "\<C-W>" */
3521 		case '<': extra = trans_special(&p, name, TRUE, TRUE);
3522 			  if (extra != 0)
3523 			  {
3524 			      name += extra;
3525 			      break;
3526 			  }
3527 			  /* FALLTHROUGH */
3528 
3529 		default:  MB_COPY_CHAR(p, name);
3530 			  break;
3531 	    }
3532 	}
3533 	else
3534 	    MB_COPY_CHAR(p, name);
3535 
3536     }
3537     *name = NUL;
3538     if (*p != NUL) /* just in case */
3539 	++p;
3540     *arg = p;
3541 
3542     return OK;
3543 }
3544 
3545 /*
3546  * Allocate a variable for a 'str''ing' constant.
3547  * Return OK or FAIL.
3548  */
3549     static int
3550 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
3551 {
3552     char_u	*p;
3553     char_u	*str;
3554     int		reduce = 0;
3555 
3556     /*
3557      * Find the end of the string, skipping ''.
3558      */
3559     for (p = *arg + 1; *p != NUL; MB_PTR_ADV(p))
3560     {
3561 	if (*p == '\'')
3562 	{
3563 	    if (p[1] != '\'')
3564 		break;
3565 	    ++reduce;
3566 	    ++p;
3567 	}
3568     }
3569 
3570     if (*p != '\'')
3571     {
3572 	semsg(_("E115: Missing quote: %s"), *arg);
3573 	return FAIL;
3574     }
3575 
3576     /* If only parsing return after setting "*arg" */
3577     if (!evaluate)
3578     {
3579 	*arg = p + 1;
3580 	return OK;
3581     }
3582 
3583     /*
3584      * Copy the string into allocated memory, handling '' to ' reduction.
3585      */
3586     str = alloc((p - *arg) - reduce);
3587     if (str == NULL)
3588 	return FAIL;
3589     rettv->v_type = VAR_STRING;
3590     rettv->vval.v_string = str;
3591 
3592     for (p = *arg + 1; *p != NUL; )
3593     {
3594 	if (*p == '\'')
3595 	{
3596 	    if (p[1] != '\'')
3597 		break;
3598 	    ++p;
3599 	}
3600 	MB_COPY_CHAR(p, str);
3601     }
3602     *str = NUL;
3603     *arg = p + 1;
3604 
3605     return OK;
3606 }
3607 
3608 /*
3609  * Return the function name of the partial.
3610  */
3611     char_u *
3612 partial_name(partial_T *pt)
3613 {
3614     if (pt->pt_name != NULL)
3615 	return pt->pt_name;
3616     return pt->pt_func->uf_name;
3617 }
3618 
3619     static void
3620 partial_free(partial_T *pt)
3621 {
3622     int i;
3623 
3624     for (i = 0; i < pt->pt_argc; ++i)
3625 	clear_tv(&pt->pt_argv[i]);
3626     vim_free(pt->pt_argv);
3627     dict_unref(pt->pt_dict);
3628     if (pt->pt_name != NULL)
3629     {
3630 	func_unref(pt->pt_name);
3631 	vim_free(pt->pt_name);
3632     }
3633     else
3634 	func_ptr_unref(pt->pt_func);
3635     vim_free(pt);
3636 }
3637 
3638 /*
3639  * Unreference a closure: decrement the reference count and free it when it
3640  * becomes zero.
3641  */
3642     void
3643 partial_unref(partial_T *pt)
3644 {
3645     if (pt != NULL && --pt->pt_refcount <= 0)
3646 	partial_free(pt);
3647 }
3648 
3649 static int tv_equal_recurse_limit;
3650 
3651     static int
3652 func_equal(
3653     typval_T *tv1,
3654     typval_T *tv2,
3655     int	     ic)	    /* ignore case */
3656 {
3657     char_u	*s1, *s2;
3658     dict_T	*d1, *d2;
3659     int		a1, a2;
3660     int		i;
3661 
3662     /* empty and NULL function name considered the same */
3663     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
3664 					   : partial_name(tv1->vval.v_partial);
3665     if (s1 != NULL && *s1 == NUL)
3666 	s1 = NULL;
3667     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
3668 					   : partial_name(tv2->vval.v_partial);
3669     if (s2 != NULL && *s2 == NUL)
3670 	s2 = NULL;
3671     if (s1 == NULL || s2 == NULL)
3672     {
3673 	if (s1 != s2)
3674 	    return FALSE;
3675     }
3676     else if (STRCMP(s1, s2) != 0)
3677 	return FALSE;
3678 
3679     /* empty dict and NULL dict is different */
3680     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
3681     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
3682     if (d1 == NULL || d2 == NULL)
3683     {
3684 	if (d1 != d2)
3685 	    return FALSE;
3686     }
3687     else if (!dict_equal(d1, d2, ic, TRUE))
3688 	return FALSE;
3689 
3690     /* empty list and no list considered the same */
3691     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
3692     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
3693     if (a1 != a2)
3694 	return FALSE;
3695     for (i = 0; i < a1; ++i)
3696 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
3697 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
3698 	    return FALSE;
3699 
3700     return TRUE;
3701 }
3702 
3703 /*
3704  * Return TRUE if "tv1" and "tv2" have the same value.
3705  * Compares the items just like "==" would compare them, but strings and
3706  * numbers are different.  Floats and numbers are also different.
3707  */
3708     int
3709 tv_equal(
3710     typval_T *tv1,
3711     typval_T *tv2,
3712     int	     ic,	    /* ignore case */
3713     int	     recursive)	    /* TRUE when used recursively */
3714 {
3715     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3716     char_u	*s1, *s2;
3717     static int  recursive_cnt = 0;	    /* catch recursive loops */
3718     int		r;
3719 
3720     /* Catch lists and dicts that have an endless loop by limiting
3721      * recursiveness to a limit.  We guess they are equal then.
3722      * A fixed limit has the problem of still taking an awful long time.
3723      * Reduce the limit every time running into it. That should work fine for
3724      * deeply linked structures that are not recursively linked and catch
3725      * recursiveness quickly. */
3726     if (!recursive)
3727 	tv_equal_recurse_limit = 1000;
3728     if (recursive_cnt >= tv_equal_recurse_limit)
3729     {
3730 	--tv_equal_recurse_limit;
3731 	return TRUE;
3732     }
3733 
3734     /* For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
3735      * arguments. */
3736     if ((tv1->v_type == VAR_FUNC
3737 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
3738 	    && (tv2->v_type == VAR_FUNC
3739 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
3740     {
3741 	++recursive_cnt;
3742 	r = func_equal(tv1, tv2, ic);
3743 	--recursive_cnt;
3744 	return r;
3745     }
3746 
3747     if (tv1->v_type != tv2->v_type)
3748 	return FALSE;
3749 
3750     switch (tv1->v_type)
3751     {
3752 	case VAR_LIST:
3753 	    ++recursive_cnt;
3754 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
3755 	    --recursive_cnt;
3756 	    return r;
3757 
3758 	case VAR_DICT:
3759 	    ++recursive_cnt;
3760 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
3761 	    --recursive_cnt;
3762 	    return r;
3763 
3764 	case VAR_BLOB:
3765 	    return blob_equal(tv1->vval.v_blob, tv2->vval.v_blob);
3766 
3767 	case VAR_NUMBER:
3768 	    return tv1->vval.v_number == tv2->vval.v_number;
3769 
3770 	case VAR_STRING:
3771 	    s1 = tv_get_string_buf(tv1, buf1);
3772 	    s2 = tv_get_string_buf(tv2, buf2);
3773 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
3774 
3775 	case VAR_SPECIAL:
3776 	    return tv1->vval.v_number == tv2->vval.v_number;
3777 
3778 	case VAR_FLOAT:
3779 #ifdef FEAT_FLOAT
3780 	    return tv1->vval.v_float == tv2->vval.v_float;
3781 #endif
3782 	case VAR_JOB:
3783 #ifdef FEAT_JOB_CHANNEL
3784 	    return tv1->vval.v_job == tv2->vval.v_job;
3785 #endif
3786 	case VAR_CHANNEL:
3787 #ifdef FEAT_JOB_CHANNEL
3788 	    return tv1->vval.v_channel == tv2->vval.v_channel;
3789 #endif
3790 	case VAR_FUNC:
3791 	case VAR_PARTIAL:
3792 	case VAR_UNKNOWN:
3793 	    break;
3794     }
3795 
3796     /* VAR_UNKNOWN can be the result of a invalid expression, let's say it
3797      * does not equal anything, not even itself. */
3798     return FALSE;
3799 }
3800 
3801 /*
3802  * Return the next (unique) copy ID.
3803  * Used for serializing nested structures.
3804  */
3805     int
3806 get_copyID(void)
3807 {
3808     current_copyID += COPYID_INC;
3809     return current_copyID;
3810 }
3811 
3812 /*
3813  * Garbage collection for lists and dictionaries.
3814  *
3815  * We use reference counts to be able to free most items right away when they
3816  * are no longer used.  But for composite items it's possible that it becomes
3817  * unused while the reference count is > 0: When there is a recursive
3818  * reference.  Example:
3819  *	:let l = [1, 2, 3]
3820  *	:let d = {9: l}
3821  *	:let l[1] = d
3822  *
3823  * Since this is quite unusual we handle this with garbage collection: every
3824  * once in a while find out which lists and dicts are not referenced from any
3825  * variable.
3826  *
3827  * Here is a good reference text about garbage collection (refers to Python
3828  * but it applies to all reference-counting mechanisms):
3829  *	http://python.ca/nas/python/gc/
3830  */
3831 
3832 /*
3833  * Do garbage collection for lists and dicts.
3834  * When "testing" is TRUE this is called from test_garbagecollect_now().
3835  * Return TRUE if some memory was freed.
3836  */
3837     int
3838 garbage_collect(int testing)
3839 {
3840     int		copyID;
3841     int		abort = FALSE;
3842     buf_T	*buf;
3843     win_T	*wp;
3844     int		did_free = FALSE;
3845     tabpage_T	*tp;
3846 
3847     if (!testing)
3848     {
3849 	/* Only do this once. */
3850 	want_garbage_collect = FALSE;
3851 	may_garbage_collect = FALSE;
3852 	garbage_collect_at_exit = FALSE;
3853     }
3854 
3855     /* We advance by two because we add one for items referenced through
3856      * previous_funccal. */
3857     copyID = get_copyID();
3858 
3859     /*
3860      * 1. Go through all accessible variables and mark all lists and dicts
3861      *    with copyID.
3862      */
3863 
3864     /* Don't free variables in the previous_funccal list unless they are only
3865      * referenced through previous_funccal.  This must be first, because if
3866      * the item is referenced elsewhere the funccal must not be freed. */
3867     abort = abort || set_ref_in_previous_funccal(copyID);
3868 
3869     /* script-local variables */
3870     abort = abort || garbage_collect_scriptvars(copyID);
3871 
3872     /* buffer-local variables */
3873     FOR_ALL_BUFFERS(buf)
3874 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
3875 								  NULL, NULL);
3876 
3877     /* window-local variables */
3878     FOR_ALL_TAB_WINDOWS(tp, wp)
3879 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3880 								  NULL, NULL);
3881     if (aucmd_win != NULL)
3882 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
3883 								  NULL, NULL);
3884 #ifdef FEAT_TEXT_PROP
3885     for (wp = first_popupwin; wp != NULL; wp = wp->w_next)
3886 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3887 								  NULL, NULL);
3888     FOR_ALL_TABPAGES(tp)
3889 	for (wp = tp->tp_first_popupwin; wp != NULL; wp = wp->w_next)
3890 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3891 								  NULL, NULL);
3892 #endif
3893 
3894     /* tabpage-local variables */
3895     FOR_ALL_TABPAGES(tp)
3896 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
3897 								  NULL, NULL);
3898     /* global variables */
3899     abort = abort || garbage_collect_globvars(copyID);
3900 
3901     /* function-local variables */
3902     abort = abort || set_ref_in_call_stack(copyID);
3903 
3904     /* named functions (matters for closures) */
3905     abort = abort || set_ref_in_functions(copyID);
3906 
3907     /* function call arguments, if v:testing is set. */
3908     abort = abort || set_ref_in_func_args(copyID);
3909 
3910     /* v: vars */
3911     abort = abort || garbage_collect_vimvars(copyID);
3912 
3913     // callbacks in buffers
3914     abort = abort || set_ref_in_buffers(copyID);
3915 
3916 #ifdef FEAT_LUA
3917     abort = abort || set_ref_in_lua(copyID);
3918 #endif
3919 
3920 #ifdef FEAT_PYTHON
3921     abort = abort || set_ref_in_python(copyID);
3922 #endif
3923 
3924 #ifdef FEAT_PYTHON3
3925     abort = abort || set_ref_in_python3(copyID);
3926 #endif
3927 
3928 #ifdef FEAT_JOB_CHANNEL
3929     abort = abort || set_ref_in_channel(copyID);
3930     abort = abort || set_ref_in_job(copyID);
3931 #endif
3932 #ifdef FEAT_NETBEANS_INTG
3933     abort = abort || set_ref_in_nb_channel(copyID);
3934 #endif
3935 
3936 #ifdef FEAT_TIMERS
3937     abort = abort || set_ref_in_timer(copyID);
3938 #endif
3939 
3940 #ifdef FEAT_QUICKFIX
3941     abort = abort || set_ref_in_quickfix(copyID);
3942 #endif
3943 
3944 #ifdef FEAT_TERMINAL
3945     abort = abort || set_ref_in_term(copyID);
3946 #endif
3947 
3948 #ifdef FEAT_TEXT_PROP
3949     abort = abort || set_ref_in_popups(copyID);
3950 #endif
3951 
3952     if (!abort)
3953     {
3954 	/*
3955 	 * 2. Free lists and dictionaries that are not referenced.
3956 	 */
3957 	did_free = free_unref_items(copyID);
3958 
3959 	/*
3960 	 * 3. Check if any funccal can be freed now.
3961 	 *    This may call us back recursively.
3962 	 */
3963 	free_unref_funccal(copyID, testing);
3964     }
3965     else if (p_verbose > 0)
3966     {
3967 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
3968     }
3969 
3970     return did_free;
3971 }
3972 
3973 /*
3974  * Free lists, dictionaries, channels and jobs that are no longer referenced.
3975  */
3976     static int
3977 free_unref_items(int copyID)
3978 {
3979     int		did_free = FALSE;
3980 
3981     /* Let all "free" functions know that we are here.  This means no
3982      * dictionaries, lists, channels or jobs are to be freed, because we will
3983      * do that here. */
3984     in_free_unref_items = TRUE;
3985 
3986     /*
3987      * PASS 1: free the contents of the items.  We don't free the items
3988      * themselves yet, so that it is possible to decrement refcount counters
3989      */
3990 
3991     /* Go through the list of dicts and free items without the copyID. */
3992     did_free |= dict_free_nonref(copyID);
3993 
3994     /* Go through the list of lists and free items without the copyID. */
3995     did_free |= list_free_nonref(copyID);
3996 
3997 #ifdef FEAT_JOB_CHANNEL
3998     /* Go through the list of jobs and free items without the copyID. This
3999      * must happen before doing channels, because jobs refer to channels, but
4000      * the reference from the channel to the job isn't tracked. */
4001     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4002 
4003     /* Go through the list of channels and free items without the copyID.  */
4004     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4005 #endif
4006 
4007     /*
4008      * PASS 2: free the items themselves.
4009      */
4010     dict_free_items(copyID);
4011     list_free_items(copyID);
4012 
4013 #ifdef FEAT_JOB_CHANNEL
4014     /* Go through the list of jobs and free items without the copyID. This
4015      * must happen before doing channels, because jobs refer to channels, but
4016      * the reference from the channel to the job isn't tracked. */
4017     free_unused_jobs(copyID, COPYID_MASK);
4018 
4019     /* Go through the list of channels and free items without the copyID.  */
4020     free_unused_channels(copyID, COPYID_MASK);
4021 #endif
4022 
4023     in_free_unref_items = FALSE;
4024 
4025     return did_free;
4026 }
4027 
4028 /*
4029  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4030  * "list_stack" is used to add lists to be marked.  Can be NULL.
4031  *
4032  * Returns TRUE if setting references failed somehow.
4033  */
4034     int
4035 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4036 {
4037     int		todo;
4038     int		abort = FALSE;
4039     hashitem_T	*hi;
4040     hashtab_T	*cur_ht;
4041     ht_stack_T	*ht_stack = NULL;
4042     ht_stack_T	*tempitem;
4043 
4044     cur_ht = ht;
4045     for (;;)
4046     {
4047 	if (!abort)
4048 	{
4049 	    /* Mark each item in the hashtab.  If the item contains a hashtab
4050 	     * it is added to ht_stack, if it contains a list it is added to
4051 	     * list_stack. */
4052 	    todo = (int)cur_ht->ht_used;
4053 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4054 		if (!HASHITEM_EMPTY(hi))
4055 		{
4056 		    --todo;
4057 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4058 						       &ht_stack, list_stack);
4059 		}
4060 	}
4061 
4062 	if (ht_stack == NULL)
4063 	    break;
4064 
4065 	/* take an item from the stack */
4066 	cur_ht = ht_stack->ht;
4067 	tempitem = ht_stack;
4068 	ht_stack = ht_stack->prev;
4069 	free(tempitem);
4070     }
4071 
4072     return abort;
4073 }
4074 
4075 /*
4076  * Mark a dict and its items with "copyID".
4077  * Returns TRUE if setting references failed somehow.
4078  */
4079     int
4080 set_ref_in_dict(dict_T *d, int copyID)
4081 {
4082     if (d != NULL && d->dv_copyID != copyID)
4083     {
4084 	d->dv_copyID = copyID;
4085 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4086     }
4087     return FALSE;
4088 }
4089 
4090 /*
4091  * Mark a list and its items with "copyID".
4092  * Returns TRUE if setting references failed somehow.
4093  */
4094     int
4095 set_ref_in_list(list_T *ll, int copyID)
4096 {
4097     if (ll != NULL && ll->lv_copyID != copyID)
4098     {
4099 	ll->lv_copyID = copyID;
4100 	return set_ref_in_list_items(ll, copyID, NULL);
4101     }
4102     return FALSE;
4103 }
4104 
4105 /*
4106  * Mark all lists and dicts referenced through list "l" with "copyID".
4107  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4108  *
4109  * Returns TRUE if setting references failed somehow.
4110  */
4111     int
4112 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4113 {
4114     listitem_T	 *li;
4115     int		 abort = FALSE;
4116     list_T	 *cur_l;
4117     list_stack_T *list_stack = NULL;
4118     list_stack_T *tempitem;
4119 
4120     cur_l = l;
4121     for (;;)
4122     {
4123 	if (!abort)
4124 	    /* Mark each item in the list.  If the item contains a hashtab
4125 	     * it is added to ht_stack, if it contains a list it is added to
4126 	     * list_stack. */
4127 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4128 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4129 						       ht_stack, &list_stack);
4130 	if (list_stack == NULL)
4131 	    break;
4132 
4133 	/* take an item from the stack */
4134 	cur_l = list_stack->list;
4135 	tempitem = list_stack;
4136 	list_stack = list_stack->prev;
4137 	free(tempitem);
4138     }
4139 
4140     return abort;
4141 }
4142 
4143 /*
4144  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4145  * "list_stack" is used to add lists to be marked.  Can be NULL.
4146  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4147  *
4148  * Returns TRUE if setting references failed somehow.
4149  */
4150     int
4151 set_ref_in_item(
4152     typval_T	    *tv,
4153     int		    copyID,
4154     ht_stack_T	    **ht_stack,
4155     list_stack_T    **list_stack)
4156 {
4157     int		abort = FALSE;
4158 
4159     if (tv->v_type == VAR_DICT)
4160     {
4161 	dict_T	*dd = tv->vval.v_dict;
4162 
4163 	if (dd != NULL && dd->dv_copyID != copyID)
4164 	{
4165 	    /* Didn't see this dict yet. */
4166 	    dd->dv_copyID = copyID;
4167 	    if (ht_stack == NULL)
4168 	    {
4169 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4170 	    }
4171 	    else
4172 	    {
4173 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
4174 		if (newitem == NULL)
4175 		    abort = TRUE;
4176 		else
4177 		{
4178 		    newitem->ht = &dd->dv_hashtab;
4179 		    newitem->prev = *ht_stack;
4180 		    *ht_stack = newitem;
4181 		}
4182 	    }
4183 	}
4184     }
4185     else if (tv->v_type == VAR_LIST)
4186     {
4187 	list_T	*ll = tv->vval.v_list;
4188 
4189 	if (ll != NULL && ll->lv_copyID != copyID)
4190 	{
4191 	    /* Didn't see this list yet. */
4192 	    ll->lv_copyID = copyID;
4193 	    if (list_stack == NULL)
4194 	    {
4195 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4196 	    }
4197 	    else
4198 	    {
4199 		list_stack_T *newitem = (list_stack_T*)malloc(
4200 							sizeof(list_stack_T));
4201 		if (newitem == NULL)
4202 		    abort = TRUE;
4203 		else
4204 		{
4205 		    newitem->list = ll;
4206 		    newitem->prev = *list_stack;
4207 		    *list_stack = newitem;
4208 		}
4209 	    }
4210 	}
4211     }
4212     else if (tv->v_type == VAR_FUNC)
4213     {
4214 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4215     }
4216     else if (tv->v_type == VAR_PARTIAL)
4217     {
4218 	partial_T	*pt = tv->vval.v_partial;
4219 	int		i;
4220 
4221 	/* A partial does not have a copyID, because it cannot contain itself.
4222 	 */
4223 	if (pt != NULL)
4224 	{
4225 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4226 
4227 	    if (pt->pt_dict != NULL)
4228 	    {
4229 		typval_T dtv;
4230 
4231 		dtv.v_type = VAR_DICT;
4232 		dtv.vval.v_dict = pt->pt_dict;
4233 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4234 	    }
4235 
4236 	    for (i = 0; i < pt->pt_argc; ++i)
4237 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4238 							ht_stack, list_stack);
4239 	}
4240     }
4241 #ifdef FEAT_JOB_CHANNEL
4242     else if (tv->v_type == VAR_JOB)
4243     {
4244 	job_T	    *job = tv->vval.v_job;
4245 	typval_T    dtv;
4246 
4247 	if (job != NULL && job->jv_copyID != copyID)
4248 	{
4249 	    job->jv_copyID = copyID;
4250 	    if (job->jv_channel != NULL)
4251 	    {
4252 		dtv.v_type = VAR_CHANNEL;
4253 		dtv.vval.v_channel = job->jv_channel;
4254 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4255 	    }
4256 	    if (job->jv_exit_cb.cb_partial != NULL)
4257 	    {
4258 		dtv.v_type = VAR_PARTIAL;
4259 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4260 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4261 	    }
4262 	}
4263     }
4264     else if (tv->v_type == VAR_CHANNEL)
4265     {
4266 	channel_T   *ch =tv->vval.v_channel;
4267 	ch_part_T   part;
4268 	typval_T    dtv;
4269 	jsonq_T	    *jq;
4270 	cbq_T	    *cq;
4271 
4272 	if (ch != NULL && ch->ch_copyID != copyID)
4273 	{
4274 	    ch->ch_copyID = copyID;
4275 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4276 	    {
4277 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4278 							     jq = jq->jq_next)
4279 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4280 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4281 							     cq = cq->cq_next)
4282 		    if (cq->cq_callback.cb_partial != NULL)
4283 		    {
4284 			dtv.v_type = VAR_PARTIAL;
4285 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4286 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4287 		    }
4288 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4289 		{
4290 		    dtv.v_type = VAR_PARTIAL;
4291 		    dtv.vval.v_partial =
4292 				      ch->ch_part[part].ch_callback.cb_partial;
4293 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4294 		}
4295 	    }
4296 	    if (ch->ch_callback.cb_partial != NULL)
4297 	    {
4298 		dtv.v_type = VAR_PARTIAL;
4299 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4300 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4301 	    }
4302 	    if (ch->ch_close_cb.cb_partial != NULL)
4303 	    {
4304 		dtv.v_type = VAR_PARTIAL;
4305 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4306 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4307 	    }
4308 	}
4309     }
4310 #endif
4311     return abort;
4312 }
4313 
4314 /*
4315  * Return a string with the string representation of a variable.
4316  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4317  * "numbuf" is used for a number.
4318  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4319  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4320  * stings as "string()", otherwise does not put quotes around strings, as
4321  * ":echo" displays values.
4322  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4323  * are replaced with "...".
4324  * May return NULL.
4325  */
4326     char_u *
4327 echo_string_core(
4328     typval_T	*tv,
4329     char_u	**tofree,
4330     char_u	*numbuf,
4331     int		copyID,
4332     int		echo_style,
4333     int		restore_copyID,
4334     int		composite_val)
4335 {
4336     static int	recurse = 0;
4337     char_u	*r = NULL;
4338 
4339     if (recurse >= DICT_MAXNEST)
4340     {
4341 	if (!did_echo_string_emsg)
4342 	{
4343 	    /* Only give this message once for a recursive call to avoid
4344 	     * flooding the user with errors.  And stop iterating over lists
4345 	     * and dicts. */
4346 	    did_echo_string_emsg = TRUE;
4347 	    emsg(_("E724: variable nested too deep for displaying"));
4348 	}
4349 	*tofree = NULL;
4350 	return (char_u *)"{E724}";
4351     }
4352     ++recurse;
4353 
4354     switch (tv->v_type)
4355     {
4356 	case VAR_STRING:
4357 	    if (echo_style && !composite_val)
4358 	    {
4359 		*tofree = NULL;
4360 		r = tv->vval.v_string;
4361 		if (r == NULL)
4362 		    r = (char_u *)"";
4363 	    }
4364 	    else
4365 	    {
4366 		*tofree = string_quote(tv->vval.v_string, FALSE);
4367 		r = *tofree;
4368 	    }
4369 	    break;
4370 
4371 	case VAR_FUNC:
4372 	    if (echo_style)
4373 	    {
4374 		*tofree = NULL;
4375 		r = tv->vval.v_string;
4376 	    }
4377 	    else
4378 	    {
4379 		*tofree = string_quote(tv->vval.v_string, TRUE);
4380 		r = *tofree;
4381 	    }
4382 	    break;
4383 
4384 	case VAR_PARTIAL:
4385 	    {
4386 		partial_T   *pt = tv->vval.v_partial;
4387 		char_u	    *fname = string_quote(pt == NULL ? NULL
4388 						    : partial_name(pt), FALSE);
4389 		garray_T    ga;
4390 		int	    i;
4391 		char_u	    *tf;
4392 
4393 		ga_init2(&ga, 1, 100);
4394 		ga_concat(&ga, (char_u *)"function(");
4395 		if (fname != NULL)
4396 		{
4397 		    ga_concat(&ga, fname);
4398 		    vim_free(fname);
4399 		}
4400 		if (pt != NULL && pt->pt_argc > 0)
4401 		{
4402 		    ga_concat(&ga, (char_u *)", [");
4403 		    for (i = 0; i < pt->pt_argc; ++i)
4404 		    {
4405 			if (i > 0)
4406 			    ga_concat(&ga, (char_u *)", ");
4407 			ga_concat(&ga,
4408 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
4409 			vim_free(tf);
4410 		    }
4411 		    ga_concat(&ga, (char_u *)"]");
4412 		}
4413 		if (pt != NULL && pt->pt_dict != NULL)
4414 		{
4415 		    typval_T dtv;
4416 
4417 		    ga_concat(&ga, (char_u *)", ");
4418 		    dtv.v_type = VAR_DICT;
4419 		    dtv.vval.v_dict = pt->pt_dict;
4420 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
4421 		    vim_free(tf);
4422 		}
4423 		ga_concat(&ga, (char_u *)")");
4424 
4425 		*tofree = ga.ga_data;
4426 		r = *tofree;
4427 		break;
4428 	    }
4429 
4430 	case VAR_BLOB:
4431 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
4432 	    break;
4433 
4434 	case VAR_LIST:
4435 	    if (tv->vval.v_list == NULL)
4436 	    {
4437 		*tofree = NULL;
4438 		r = NULL;
4439 	    }
4440 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
4441 		    && tv->vval.v_list->lv_len > 0)
4442 	    {
4443 		*tofree = NULL;
4444 		r = (char_u *)"[...]";
4445 	    }
4446 	    else
4447 	    {
4448 		int old_copyID = tv->vval.v_list->lv_copyID;
4449 
4450 		tv->vval.v_list->lv_copyID = copyID;
4451 		*tofree = list2string(tv, copyID, restore_copyID);
4452 		if (restore_copyID)
4453 		    tv->vval.v_list->lv_copyID = old_copyID;
4454 		r = *tofree;
4455 	    }
4456 	    break;
4457 
4458 	case VAR_DICT:
4459 	    if (tv->vval.v_dict == NULL)
4460 	    {
4461 		*tofree = NULL;
4462 		r = NULL;
4463 	    }
4464 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
4465 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
4466 	    {
4467 		*tofree = NULL;
4468 		r = (char_u *)"{...}";
4469 	    }
4470 	    else
4471 	    {
4472 		int old_copyID = tv->vval.v_dict->dv_copyID;
4473 		tv->vval.v_dict->dv_copyID = copyID;
4474 		*tofree = dict2string(tv, copyID, restore_copyID);
4475 		if (restore_copyID)
4476 		    tv->vval.v_dict->dv_copyID = old_copyID;
4477 		r = *tofree;
4478 	    }
4479 	    break;
4480 
4481 	case VAR_NUMBER:
4482 	case VAR_UNKNOWN:
4483 	    *tofree = NULL;
4484 	    r = tv_get_string_buf(tv, numbuf);
4485 	    break;
4486 
4487 	case VAR_JOB:
4488 	case VAR_CHANNEL:
4489 	    *tofree = NULL;
4490 	    r = tv_get_string_buf(tv, numbuf);
4491 	    if (composite_val)
4492 	    {
4493 		*tofree = string_quote(r, FALSE);
4494 		r = *tofree;
4495 	    }
4496 	    break;
4497 
4498 	case VAR_FLOAT:
4499 #ifdef FEAT_FLOAT
4500 	    *tofree = NULL;
4501 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
4502 	    r = numbuf;
4503 	    break;
4504 #endif
4505 
4506 	case VAR_SPECIAL:
4507 	    *tofree = NULL;
4508 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
4509 	    break;
4510     }
4511 
4512     if (--recurse == 0)
4513 	did_echo_string_emsg = FALSE;
4514     return r;
4515 }
4516 
4517 /*
4518  * Return a string with the string representation of a variable.
4519  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4520  * "numbuf" is used for a number.
4521  * Does not put quotes around strings, as ":echo" displays values.
4522  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4523  * May return NULL.
4524  */
4525     char_u *
4526 echo_string(
4527     typval_T	*tv,
4528     char_u	**tofree,
4529     char_u	*numbuf,
4530     int		copyID)
4531 {
4532     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
4533 }
4534 
4535 /*
4536  * Return a string with the string representation of a variable.
4537  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4538  * "numbuf" is used for a number.
4539  * Puts quotes around strings, so that they can be parsed back by eval().
4540  * May return NULL.
4541  */
4542     char_u *
4543 tv2string(
4544     typval_T	*tv,
4545     char_u	**tofree,
4546     char_u	*numbuf,
4547     int		copyID)
4548 {
4549     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
4550 }
4551 
4552 /*
4553  * Return string "str" in ' quotes, doubling ' characters.
4554  * If "str" is NULL an empty string is assumed.
4555  * If "function" is TRUE make it function('string').
4556  */
4557     char_u *
4558 string_quote(char_u *str, int function)
4559 {
4560     unsigned	len;
4561     char_u	*p, *r, *s;
4562 
4563     len = (function ? 13 : 3);
4564     if (str != NULL)
4565     {
4566 	len += (unsigned)STRLEN(str);
4567 	for (p = str; *p != NUL; MB_PTR_ADV(p))
4568 	    if (*p == '\'')
4569 		++len;
4570     }
4571     s = r = alloc(len);
4572     if (r != NULL)
4573     {
4574 	if (function)
4575 	{
4576 	    STRCPY(r, "function('");
4577 	    r += 10;
4578 	}
4579 	else
4580 	    *r++ = '\'';
4581 	if (str != NULL)
4582 	    for (p = str; *p != NUL; )
4583 	    {
4584 		if (*p == '\'')
4585 		    *r++ = '\'';
4586 		MB_COPY_CHAR(p, r);
4587 	    }
4588 	*r++ = '\'';
4589 	if (function)
4590 	    *r++ = ')';
4591 	*r++ = NUL;
4592     }
4593     return s;
4594 }
4595 
4596 #if defined(FEAT_FLOAT) || defined(PROTO)
4597 /*
4598  * Convert the string "text" to a floating point number.
4599  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
4600  * this always uses a decimal point.
4601  * Returns the length of the text that was consumed.
4602  */
4603     int
4604 string2float(
4605     char_u	*text,
4606     float_T	*value)	    /* result stored here */
4607 {
4608     char	*s = (char *)text;
4609     float_T	f;
4610 
4611     /* MS-Windows does not deal with "inf" and "nan" properly. */
4612     if (STRNICMP(text, "inf", 3) == 0)
4613     {
4614 	*value = INFINITY;
4615 	return 3;
4616     }
4617     if (STRNICMP(text, "-inf", 3) == 0)
4618     {
4619 	*value = -INFINITY;
4620 	return 4;
4621     }
4622     if (STRNICMP(text, "nan", 3) == 0)
4623     {
4624 	*value = NAN;
4625 	return 3;
4626     }
4627     f = strtod(s, &s);
4628     *value = f;
4629     return (int)((char_u *)s - text);
4630 }
4631 #endif
4632 
4633 /*
4634  * Get the value of an environment variable.
4635  * "arg" is pointing to the '$'.  It is advanced to after the name.
4636  * If the environment variable was not set, silently assume it is empty.
4637  * Return FAIL if the name is invalid.
4638  */
4639     static int
4640 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
4641 {
4642     char_u	*string = NULL;
4643     int		len;
4644     int		cc;
4645     char_u	*name;
4646     int		mustfree = FALSE;
4647 
4648     ++*arg;
4649     name = *arg;
4650     len = get_env_len(arg);
4651     if (evaluate)
4652     {
4653 	if (len == 0)
4654 	    return FAIL; /* invalid empty name */
4655 
4656 	cc = name[len];
4657 	name[len] = NUL;
4658 	/* first try vim_getenv(), fast for normal environment vars */
4659 	string = vim_getenv(name, &mustfree);
4660 	if (string != NULL && *string != NUL)
4661 	{
4662 	    if (!mustfree)
4663 		string = vim_strsave(string);
4664 	}
4665 	else
4666 	{
4667 	    if (mustfree)
4668 		vim_free(string);
4669 
4670 	    /* next try expanding things like $VIM and ${HOME} */
4671 	    string = expand_env_save(name - 1);
4672 	    if (string != NULL && *string == '$')
4673 		VIM_CLEAR(string);
4674 	}
4675 	name[len] = cc;
4676 
4677 	rettv->v_type = VAR_STRING;
4678 	rettv->vval.v_string = string;
4679     }
4680 
4681     return OK;
4682 }
4683 
4684 /*
4685  * Translate a String variable into a position.
4686  * Returns NULL when there is an error.
4687  */
4688     pos_T *
4689 var2fpos(
4690     typval_T	*varp,
4691     int		dollar_lnum,	/* TRUE when $ is last line */
4692     int		*fnum)		/* set to fnum for '0, 'A, etc. */
4693 {
4694     char_u		*name;
4695     static pos_T	pos;
4696     pos_T		*pp;
4697 
4698     /* Argument can be [lnum, col, coladd]. */
4699     if (varp->v_type == VAR_LIST)
4700     {
4701 	list_T		*l;
4702 	int		len;
4703 	int		error = FALSE;
4704 	listitem_T	*li;
4705 
4706 	l = varp->vval.v_list;
4707 	if (l == NULL)
4708 	    return NULL;
4709 
4710 	/* Get the line number */
4711 	pos.lnum = list_find_nr(l, 0L, &error);
4712 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
4713 	    return NULL;	/* invalid line number */
4714 
4715 	/* Get the column number */
4716 	pos.col = list_find_nr(l, 1L, &error);
4717 	if (error)
4718 	    return NULL;
4719 	len = (long)STRLEN(ml_get(pos.lnum));
4720 
4721 	/* We accept "$" for the column number: last column. */
4722 	li = list_find(l, 1L);
4723 	if (li != NULL && li->li_tv.v_type == VAR_STRING
4724 		&& li->li_tv.vval.v_string != NULL
4725 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
4726 	    pos.col = len + 1;
4727 
4728 	/* Accept a position up to the NUL after the line. */
4729 	if (pos.col == 0 || (int)pos.col > len + 1)
4730 	    return NULL;	/* invalid column number */
4731 	--pos.col;
4732 
4733 	/* Get the virtual offset.  Defaults to zero. */
4734 	pos.coladd = list_find_nr(l, 2L, &error);
4735 	if (error)
4736 	    pos.coladd = 0;
4737 
4738 	return &pos;
4739     }
4740 
4741     name = tv_get_string_chk(varp);
4742     if (name == NULL)
4743 	return NULL;
4744     if (name[0] == '.')				/* cursor */
4745 	return &curwin->w_cursor;
4746     if (name[0] == 'v' && name[1] == NUL)	/* Visual start */
4747     {
4748 	if (VIsual_active)
4749 	    return &VIsual;
4750 	return &curwin->w_cursor;
4751     }
4752     if (name[0] == '\'')			/* mark */
4753     {
4754 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
4755 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
4756 	    return NULL;
4757 	return pp;
4758     }
4759 
4760     pos.coladd = 0;
4761 
4762     if (name[0] == 'w' && dollar_lnum)
4763     {
4764 	pos.col = 0;
4765 	if (name[1] == '0')		/* "w0": first visible line */
4766 	{
4767 	    update_topline();
4768 	    /* In silent Ex mode topline is zero, but that's not a valid line
4769 	     * number; use one instead. */
4770 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
4771 	    return &pos;
4772 	}
4773 	else if (name[1] == '$')	/* "w$": last visible line */
4774 	{
4775 	    validate_botline();
4776 	    /* In silent Ex mode botline is zero, return zero then. */
4777 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
4778 	    return &pos;
4779 	}
4780     }
4781     else if (name[0] == '$')		/* last column or line */
4782     {
4783 	if (dollar_lnum)
4784 	{
4785 	    pos.lnum = curbuf->b_ml.ml_line_count;
4786 	    pos.col = 0;
4787 	}
4788 	else
4789 	{
4790 	    pos.lnum = curwin->w_cursor.lnum;
4791 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
4792 	}
4793 	return &pos;
4794     }
4795     return NULL;
4796 }
4797 
4798 /*
4799  * Convert list in "arg" into a position and optional file number.
4800  * When "fnump" is NULL there is no file number, only 3 items.
4801  * Note that the column is passed on as-is, the caller may want to decrement
4802  * it to use 1 for the first column.
4803  * Return FAIL when conversion is not possible, doesn't check the position for
4804  * validity.
4805  */
4806     int
4807 list2fpos(
4808     typval_T	*arg,
4809     pos_T	*posp,
4810     int		*fnump,
4811     colnr_T	*curswantp)
4812 {
4813     list_T	*l = arg->vval.v_list;
4814     long	i = 0;
4815     long	n;
4816 
4817     /* List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
4818      * there when "fnump" isn't NULL; "coladd" and "curswant" are optional. */
4819     if (arg->v_type != VAR_LIST
4820 	    || l == NULL
4821 	    || l->lv_len < (fnump == NULL ? 2 : 3)
4822 	    || l->lv_len > (fnump == NULL ? 4 : 5))
4823 	return FAIL;
4824 
4825     if (fnump != NULL)
4826     {
4827 	n = list_find_nr(l, i++, NULL);	/* fnum */
4828 	if (n < 0)
4829 	    return FAIL;
4830 	if (n == 0)
4831 	    n = curbuf->b_fnum;		/* current buffer */
4832 	*fnump = n;
4833     }
4834 
4835     n = list_find_nr(l, i++, NULL);	/* lnum */
4836     if (n < 0)
4837 	return FAIL;
4838     posp->lnum = n;
4839 
4840     n = list_find_nr(l, i++, NULL);	/* col */
4841     if (n < 0)
4842 	return FAIL;
4843     posp->col = n;
4844 
4845     n = list_find_nr(l, i, NULL);	/* off */
4846     if (n < 0)
4847 	posp->coladd = 0;
4848     else
4849 	posp->coladd = n;
4850 
4851     if (curswantp != NULL)
4852 	*curswantp = list_find_nr(l, i + 1, NULL);  /* curswant */
4853 
4854     return OK;
4855 }
4856 
4857 /*
4858  * Get the length of an environment variable name.
4859  * Advance "arg" to the first character after the name.
4860  * Return 0 for error.
4861  */
4862     int
4863 get_env_len(char_u **arg)
4864 {
4865     char_u	*p;
4866     int		len;
4867 
4868     for (p = *arg; vim_isIDc(*p); ++p)
4869 	;
4870     if (p == *arg)	    /* no name found */
4871 	return 0;
4872 
4873     len = (int)(p - *arg);
4874     *arg = p;
4875     return len;
4876 }
4877 
4878 /*
4879  * Get the length of the name of a function or internal variable.
4880  * "arg" is advanced to the first non-white character after the name.
4881  * Return 0 if something is wrong.
4882  */
4883     int
4884 get_id_len(char_u **arg)
4885 {
4886     char_u	*p;
4887     int		len;
4888 
4889     /* Find the end of the name. */
4890     for (p = *arg; eval_isnamec(*p); ++p)
4891     {
4892 	if (*p == ':')
4893 	{
4894 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
4895 	     * slice "[n:]".  Also "xx:" is not a namespace. */
4896 	    len = (int)(p - *arg);
4897 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
4898 		    || len > 1)
4899 		break;
4900 	}
4901     }
4902     if (p == *arg)	    /* no name found */
4903 	return 0;
4904 
4905     len = (int)(p - *arg);
4906     *arg = skipwhite(p);
4907 
4908     return len;
4909 }
4910 
4911 /*
4912  * Get the length of the name of a variable or function.
4913  * Only the name is recognized, does not handle ".key" or "[idx]".
4914  * "arg" is advanced to the first non-white character after the name.
4915  * Return -1 if curly braces expansion failed.
4916  * Return 0 if something else is wrong.
4917  * If the name contains 'magic' {}'s, expand them and return the
4918  * expanded name in an allocated string via 'alias' - caller must free.
4919  */
4920     int
4921 get_name_len(
4922     char_u	**arg,
4923     char_u	**alias,
4924     int		evaluate,
4925     int		verbose)
4926 {
4927     int		len;
4928     char_u	*p;
4929     char_u	*expr_start;
4930     char_u	*expr_end;
4931 
4932     *alias = NULL;  /* default to no alias */
4933 
4934     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
4935 						  && (*arg)[2] == (int)KE_SNR)
4936     {
4937 	/* hard coded <SNR>, already translated */
4938 	*arg += 3;
4939 	return get_id_len(arg) + 3;
4940     }
4941     len = eval_fname_script(*arg);
4942     if (len > 0)
4943     {
4944 	/* literal "<SID>", "s:" or "<SNR>" */
4945 	*arg += len;
4946     }
4947 
4948     /*
4949      * Find the end of the name; check for {} construction.
4950      */
4951     p = find_name_end(*arg, &expr_start, &expr_end,
4952 					       len > 0 ? 0 : FNE_CHECK_START);
4953     if (expr_start != NULL)
4954     {
4955 	char_u	*temp_string;
4956 
4957 	if (!evaluate)
4958 	{
4959 	    len += (int)(p - *arg);
4960 	    *arg = skipwhite(p);
4961 	    return len;
4962 	}
4963 
4964 	/*
4965 	 * Include any <SID> etc in the expanded string:
4966 	 * Thus the -len here.
4967 	 */
4968 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
4969 	if (temp_string == NULL)
4970 	    return -1;
4971 	*alias = temp_string;
4972 	*arg = skipwhite(p);
4973 	return (int)STRLEN(temp_string);
4974     }
4975 
4976     len += get_id_len(arg);
4977     // Only give an error when there is something, otherwise it will be
4978     // reported at a higher level.
4979     if (len == 0 && verbose && **arg != NUL)
4980 	semsg(_(e_invexpr2), *arg);
4981 
4982     return len;
4983 }
4984 
4985 /*
4986  * Find the end of a variable or function name, taking care of magic braces.
4987  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
4988  * start and end of the first magic braces item.
4989  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
4990  * Return a pointer to just after the name.  Equal to "arg" if there is no
4991  * valid name.
4992  */
4993     char_u *
4994 find_name_end(
4995     char_u	*arg,
4996     char_u	**expr_start,
4997     char_u	**expr_end,
4998     int		flags)
4999 {
5000     int		mb_nest = 0;
5001     int		br_nest = 0;
5002     char_u	*p;
5003     int		len;
5004 
5005     if (expr_start != NULL)
5006     {
5007 	*expr_start = NULL;
5008 	*expr_end = NULL;
5009     }
5010 
5011     /* Quick check for valid starting character. */
5012     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg) && *arg != '{')
5013 	return arg;
5014 
5015     for (p = arg; *p != NUL
5016 		    && (eval_isnamec(*p)
5017 			|| *p == '{'
5018 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
5019 			|| mb_nest != 0
5020 			|| br_nest != 0); MB_PTR_ADV(p))
5021     {
5022 	if (*p == '\'')
5023 	{
5024 	    /* skip over 'string' to avoid counting [ and ] inside it. */
5025 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5026 		;
5027 	    if (*p == NUL)
5028 		break;
5029 	}
5030 	else if (*p == '"')
5031 	{
5032 	    /* skip over "str\"ing" to avoid counting [ and ] inside it. */
5033 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5034 		if (*p == '\\' && p[1] != NUL)
5035 		    ++p;
5036 	    if (*p == NUL)
5037 		break;
5038 	}
5039 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5040 	{
5041 	    /* "s:" is start of "s:var", but "n:" is not and can be used in
5042 	     * slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is. */
5043 	    len = (int)(p - arg);
5044 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5045 		    || (len > 1 && p[-1] != '}'))
5046 		break;
5047 	}
5048 
5049 	if (mb_nest == 0)
5050 	{
5051 	    if (*p == '[')
5052 		++br_nest;
5053 	    else if (*p == ']')
5054 		--br_nest;
5055 	}
5056 
5057 	if (br_nest == 0)
5058 	{
5059 	    if (*p == '{')
5060 	    {
5061 		mb_nest++;
5062 		if (expr_start != NULL && *expr_start == NULL)
5063 		    *expr_start = p;
5064 	    }
5065 	    else if (*p == '}')
5066 	    {
5067 		mb_nest--;
5068 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5069 		    *expr_end = p;
5070 	    }
5071 	}
5072     }
5073 
5074     return p;
5075 }
5076 
5077 /*
5078  * Expands out the 'magic' {}'s in a variable/function name.
5079  * Note that this can call itself recursively, to deal with
5080  * constructs like foo{bar}{baz}{bam}
5081  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5082  *			"in_start"      ^
5083  *			"expr_start"	   ^
5084  *			"expr_end"		 ^
5085  *			"in_end"			    ^
5086  *
5087  * Returns a new allocated string, which the caller must free.
5088  * Returns NULL for failure.
5089  */
5090     static char_u *
5091 make_expanded_name(
5092     char_u	*in_start,
5093     char_u	*expr_start,
5094     char_u	*expr_end,
5095     char_u	*in_end)
5096 {
5097     char_u	c1;
5098     char_u	*retval = NULL;
5099     char_u	*temp_result;
5100     char_u	*nextcmd = NULL;
5101 
5102     if (expr_end == NULL || in_end == NULL)
5103 	return NULL;
5104     *expr_start	= NUL;
5105     *expr_end = NUL;
5106     c1 = *in_end;
5107     *in_end = NUL;
5108 
5109     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
5110     if (temp_result != NULL && nextcmd == NULL)
5111     {
5112 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5113 						   + (in_end - expr_end) + 1);
5114 	if (retval != NULL)
5115 	{
5116 	    STRCPY(retval, in_start);
5117 	    STRCAT(retval, temp_result);
5118 	    STRCAT(retval, expr_end + 1);
5119 	}
5120     }
5121     vim_free(temp_result);
5122 
5123     *in_end = c1;		/* put char back for error messages */
5124     *expr_start = '{';
5125     *expr_end = '}';
5126 
5127     if (retval != NULL)
5128     {
5129 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5130 	if (expr_start != NULL)
5131 	{
5132 	    /* Further expansion! */
5133 	    temp_result = make_expanded_name(retval, expr_start,
5134 						       expr_end, temp_result);
5135 	    vim_free(retval);
5136 	    retval = temp_result;
5137 	}
5138     }
5139 
5140     return retval;
5141 }
5142 
5143 /*
5144  * Return TRUE if character "c" can be used in a variable or function name.
5145  * Does not include '{' or '}' for magic braces.
5146  */
5147     int
5148 eval_isnamec(int c)
5149 {
5150     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
5151 }
5152 
5153 /*
5154  * Return TRUE if character "c" can be used as the first character in a
5155  * variable or function name (excluding '{' and '}').
5156  */
5157     int
5158 eval_isnamec1(int c)
5159 {
5160     return (ASCII_ISALPHA(c) || c == '_');
5161 }
5162 
5163 /*
5164  * Handle:
5165  * - expr[expr], expr[expr:expr] subscript
5166  * - ".name" lookup
5167  * - function call with Funcref variable: func(expr)
5168  * - method call: var->method()
5169  *
5170  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5171  */
5172     int
5173 handle_subscript(
5174     char_u	**arg,
5175     typval_T	*rettv,
5176     int		evaluate,	// do more than finding the end
5177     int		verbose,	// give error messages
5178     char_u	*start_leader,	// start of '!' and '-' prefixes
5179     char_u	**end_leaderp)  // end of '!' and '-' prefixes
5180 {
5181     int		ret = OK;
5182     dict_T	*selfdict = NULL;
5183 
5184     // "." is ".name" lookup when we found a dict or when evaluating and
5185     // scriptversion is at least 2, where string concatenation is "..".
5186     while (ret == OK
5187 	    && (((**arg == '['
5188 		    || (**arg == '.' && (rettv->v_type == VAR_DICT
5189 			|| (!evaluate
5190 			    && (*arg)[1] != '.'
5191 			    && current_sctx.sc_version >= 2)))
5192 		    || (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5193 					    || rettv->v_type == VAR_PARTIAL)))
5194 		&& !VIM_ISWHITE(*(*arg - 1)))
5195 	    || (**arg == '-' && (*arg)[1] == '>')))
5196     {
5197 	if (**arg == '(')
5198 	{
5199 	    ret = call_func_rettv(arg, rettv, evaluate, selfdict, NULL);
5200 
5201 	    // Stop the expression evaluation when immediately aborting on
5202 	    // error, or when an interrupt occurred or an exception was thrown
5203 	    // but not caught.
5204 	    if (aborting())
5205 	    {
5206 		if (ret == OK)
5207 		    clear_tv(rettv);
5208 		ret = FAIL;
5209 	    }
5210 	    dict_unref(selfdict);
5211 	    selfdict = NULL;
5212 	}
5213 	else if (**arg == '-')
5214 	{
5215 	    // Expression "-1.0->method()" applies the leader "-" before
5216 	    // applying ->.
5217 	    if (evaluate && *end_leaderp > start_leader)
5218 		ret = eval7_leader(rettv, start_leader, end_leaderp);
5219 	    if (ret == OK)
5220 	    {
5221 		if ((*arg)[2] == '{')
5222 		    // expr->{lambda}()
5223 		    ret = eval_lambda(arg, rettv, evaluate, verbose);
5224 		else
5225 		    // expr->name()
5226 		    ret = eval_method(arg, rettv, evaluate, verbose);
5227 	    }
5228 	}
5229 	else /* **arg == '[' || **arg == '.' */
5230 	{
5231 	    dict_unref(selfdict);
5232 	    if (rettv->v_type == VAR_DICT)
5233 	    {
5234 		selfdict = rettv->vval.v_dict;
5235 		if (selfdict != NULL)
5236 		    ++selfdict->dv_refcount;
5237 	    }
5238 	    else
5239 		selfdict = NULL;
5240 	    if (eval_index(arg, rettv, evaluate, verbose) == FAIL)
5241 	    {
5242 		clear_tv(rettv);
5243 		ret = FAIL;
5244 	    }
5245 	}
5246     }
5247 
5248     /* Turn "dict.Func" into a partial for "Func" bound to "dict".
5249      * Don't do this when "Func" is already a partial that was bound
5250      * explicitly (pt_auto is FALSE). */
5251     if (selfdict != NULL
5252 	    && (rettv->v_type == VAR_FUNC
5253 		|| (rettv->v_type == VAR_PARTIAL
5254 		    && (rettv->vval.v_partial->pt_auto
5255 			|| rettv->vval.v_partial->pt_dict == NULL))))
5256 	selfdict = make_partial(selfdict, rettv);
5257 
5258     dict_unref(selfdict);
5259     return ret;
5260 }
5261 
5262 /*
5263  * Allocate memory for a variable type-value, and make it empty (0 or NULL
5264  * value).
5265  */
5266     typval_T *
5267 alloc_tv(void)
5268 {
5269     return ALLOC_CLEAR_ONE(typval_T);
5270 }
5271 
5272 /*
5273  * Allocate memory for a variable type-value, and assign a string to it.
5274  * The string "s" must have been allocated, it is consumed.
5275  * Return NULL for out of memory, the variable otherwise.
5276  */
5277     typval_T *
5278 alloc_string_tv(char_u *s)
5279 {
5280     typval_T	*rettv;
5281 
5282     rettv = alloc_tv();
5283     if (rettv != NULL)
5284     {
5285 	rettv->v_type = VAR_STRING;
5286 	rettv->vval.v_string = s;
5287     }
5288     else
5289 	vim_free(s);
5290     return rettv;
5291 }
5292 
5293 /*
5294  * Free the memory for a variable type-value.
5295  */
5296     void
5297 free_tv(typval_T *varp)
5298 {
5299     if (varp != NULL)
5300     {
5301 	switch (varp->v_type)
5302 	{
5303 	    case VAR_FUNC:
5304 		func_unref(varp->vval.v_string);
5305 		/* FALLTHROUGH */
5306 	    case VAR_STRING:
5307 		vim_free(varp->vval.v_string);
5308 		break;
5309 	    case VAR_PARTIAL:
5310 		partial_unref(varp->vval.v_partial);
5311 		break;
5312 	    case VAR_BLOB:
5313 		blob_unref(varp->vval.v_blob);
5314 		break;
5315 	    case VAR_LIST:
5316 		list_unref(varp->vval.v_list);
5317 		break;
5318 	    case VAR_DICT:
5319 		dict_unref(varp->vval.v_dict);
5320 		break;
5321 	    case VAR_JOB:
5322 #ifdef FEAT_JOB_CHANNEL
5323 		job_unref(varp->vval.v_job);
5324 		break;
5325 #endif
5326 	    case VAR_CHANNEL:
5327 #ifdef FEAT_JOB_CHANNEL
5328 		channel_unref(varp->vval.v_channel);
5329 		break;
5330 #endif
5331 	    case VAR_NUMBER:
5332 	    case VAR_FLOAT:
5333 	    case VAR_UNKNOWN:
5334 	    case VAR_SPECIAL:
5335 		break;
5336 	}
5337 	vim_free(varp);
5338     }
5339 }
5340 
5341 /*
5342  * Free the memory for a variable value and set the value to NULL or 0.
5343  */
5344     void
5345 clear_tv(typval_T *varp)
5346 {
5347     if (varp != NULL)
5348     {
5349 	switch (varp->v_type)
5350 	{
5351 	    case VAR_FUNC:
5352 		func_unref(varp->vval.v_string);
5353 		/* FALLTHROUGH */
5354 	    case VAR_STRING:
5355 		VIM_CLEAR(varp->vval.v_string);
5356 		break;
5357 	    case VAR_PARTIAL:
5358 		partial_unref(varp->vval.v_partial);
5359 		varp->vval.v_partial = NULL;
5360 		break;
5361 	    case VAR_BLOB:
5362 		blob_unref(varp->vval.v_blob);
5363 		varp->vval.v_blob = NULL;
5364 		break;
5365 	    case VAR_LIST:
5366 		list_unref(varp->vval.v_list);
5367 		varp->vval.v_list = NULL;
5368 		break;
5369 	    case VAR_DICT:
5370 		dict_unref(varp->vval.v_dict);
5371 		varp->vval.v_dict = NULL;
5372 		break;
5373 	    case VAR_NUMBER:
5374 	    case VAR_SPECIAL:
5375 		varp->vval.v_number = 0;
5376 		break;
5377 	    case VAR_FLOAT:
5378 #ifdef FEAT_FLOAT
5379 		varp->vval.v_float = 0.0;
5380 		break;
5381 #endif
5382 	    case VAR_JOB:
5383 #ifdef FEAT_JOB_CHANNEL
5384 		job_unref(varp->vval.v_job);
5385 		varp->vval.v_job = NULL;
5386 #endif
5387 		break;
5388 	    case VAR_CHANNEL:
5389 #ifdef FEAT_JOB_CHANNEL
5390 		channel_unref(varp->vval.v_channel);
5391 		varp->vval.v_channel = NULL;
5392 #endif
5393 	    case VAR_UNKNOWN:
5394 		break;
5395 	}
5396 	varp->v_lock = 0;
5397     }
5398 }
5399 
5400 /*
5401  * Set the value of a variable to NULL without freeing items.
5402  */
5403     void
5404 init_tv(typval_T *varp)
5405 {
5406     if (varp != NULL)
5407 	vim_memset(varp, 0, sizeof(typval_T));
5408 }
5409 
5410 /*
5411  * Get the number value of a variable.
5412  * If it is a String variable, uses vim_str2nr().
5413  * For incompatible types, return 0.
5414  * tv_get_number_chk() is similar to tv_get_number(), but informs the
5415  * caller of incompatible types: it sets *denote to TRUE if "denote"
5416  * is not NULL or returns -1 otherwise.
5417  */
5418     varnumber_T
5419 tv_get_number(typval_T *varp)
5420 {
5421     int		error = FALSE;
5422 
5423     return tv_get_number_chk(varp, &error);	/* return 0L on error */
5424 }
5425 
5426     varnumber_T
5427 tv_get_number_chk(typval_T *varp, int *denote)
5428 {
5429     varnumber_T	n = 0L;
5430 
5431     switch (varp->v_type)
5432     {
5433 	case VAR_NUMBER:
5434 	    return varp->vval.v_number;
5435 	case VAR_FLOAT:
5436 #ifdef FEAT_FLOAT
5437 	    emsg(_("E805: Using a Float as a Number"));
5438 	    break;
5439 #endif
5440 	case VAR_FUNC:
5441 	case VAR_PARTIAL:
5442 	    emsg(_("E703: Using a Funcref as a Number"));
5443 	    break;
5444 	case VAR_STRING:
5445 	    if (varp->vval.v_string != NULL)
5446 		vim_str2nr(varp->vval.v_string, NULL, NULL,
5447 					    STR2NR_ALL, &n, NULL, 0, FALSE);
5448 	    return n;
5449 	case VAR_LIST:
5450 	    emsg(_("E745: Using a List as a Number"));
5451 	    break;
5452 	case VAR_DICT:
5453 	    emsg(_("E728: Using a Dictionary as a Number"));
5454 	    break;
5455 	case VAR_SPECIAL:
5456 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
5457 	    break;
5458 	case VAR_JOB:
5459 #ifdef FEAT_JOB_CHANNEL
5460 	    emsg(_("E910: Using a Job as a Number"));
5461 	    break;
5462 #endif
5463 	case VAR_CHANNEL:
5464 #ifdef FEAT_JOB_CHANNEL
5465 	    emsg(_("E913: Using a Channel as a Number"));
5466 	    break;
5467 #endif
5468 	case VAR_BLOB:
5469 	    emsg(_("E974: Using a Blob as a Number"));
5470 	    break;
5471 	case VAR_UNKNOWN:
5472 	    internal_error("tv_get_number(UNKNOWN)");
5473 	    break;
5474     }
5475     if (denote == NULL)		/* useful for values that must be unsigned */
5476 	n = -1;
5477     else
5478 	*denote = TRUE;
5479     return n;
5480 }
5481 
5482 #ifdef FEAT_FLOAT
5483     float_T
5484 tv_get_float(typval_T *varp)
5485 {
5486     switch (varp->v_type)
5487     {
5488 	case VAR_NUMBER:
5489 	    return (float_T)(varp->vval.v_number);
5490 	case VAR_FLOAT:
5491 	    return varp->vval.v_float;
5492 	case VAR_FUNC:
5493 	case VAR_PARTIAL:
5494 	    emsg(_("E891: Using a Funcref as a Float"));
5495 	    break;
5496 	case VAR_STRING:
5497 	    emsg(_("E892: Using a String as a Float"));
5498 	    break;
5499 	case VAR_LIST:
5500 	    emsg(_("E893: Using a List as a Float"));
5501 	    break;
5502 	case VAR_DICT:
5503 	    emsg(_("E894: Using a Dictionary as a Float"));
5504 	    break;
5505 	case VAR_SPECIAL:
5506 	    emsg(_("E907: Using a special value as a Float"));
5507 	    break;
5508 	case VAR_JOB:
5509 # ifdef FEAT_JOB_CHANNEL
5510 	    emsg(_("E911: Using a Job as a Float"));
5511 	    break;
5512 # endif
5513 	case VAR_CHANNEL:
5514 # ifdef FEAT_JOB_CHANNEL
5515 	    emsg(_("E914: Using a Channel as a Float"));
5516 	    break;
5517 # endif
5518 	case VAR_BLOB:
5519 	    emsg(_("E975: Using a Blob as a Float"));
5520 	    break;
5521 	case VAR_UNKNOWN:
5522 	    internal_error("tv_get_float(UNKNOWN)");
5523 	    break;
5524     }
5525     return 0;
5526 }
5527 #endif
5528 
5529 /*
5530  * Get the string value of a variable.
5531  * If it is a Number variable, the number is converted into a string.
5532  * tv_get_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
5533  * tv_get_string_buf() uses a given buffer.
5534  * If the String variable has never been set, return an empty string.
5535  * Never returns NULL;
5536  * tv_get_string_chk() and tv_get_string_buf_chk() are similar, but return
5537  * NULL on error.
5538  */
5539     char_u *
5540 tv_get_string(typval_T *varp)
5541 {
5542     static char_u   mybuf[NUMBUFLEN];
5543 
5544     return tv_get_string_buf(varp, mybuf);
5545 }
5546 
5547     char_u *
5548 tv_get_string_buf(typval_T *varp, char_u *buf)
5549 {
5550     char_u	*res =  tv_get_string_buf_chk(varp, buf);
5551 
5552     return res != NULL ? res : (char_u *)"";
5553 }
5554 
5555 /*
5556  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
5557  */
5558     char_u *
5559 tv_get_string_chk(typval_T *varp)
5560 {
5561     static char_u   mybuf[NUMBUFLEN];
5562 
5563     return tv_get_string_buf_chk(varp, mybuf);
5564 }
5565 
5566     char_u *
5567 tv_get_string_buf_chk(typval_T *varp, char_u *buf)
5568 {
5569     switch (varp->v_type)
5570     {
5571 	case VAR_NUMBER:
5572 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
5573 					    (long_long_T)varp->vval.v_number);
5574 	    return buf;
5575 	case VAR_FUNC:
5576 	case VAR_PARTIAL:
5577 	    emsg(_("E729: using Funcref as a String"));
5578 	    break;
5579 	case VAR_LIST:
5580 	    emsg(_("E730: using List as a String"));
5581 	    break;
5582 	case VAR_DICT:
5583 	    emsg(_("E731: using Dictionary as a String"));
5584 	    break;
5585 	case VAR_FLOAT:
5586 #ifdef FEAT_FLOAT
5587 	    emsg(_(e_float_as_string));
5588 	    break;
5589 #endif
5590 	case VAR_STRING:
5591 	    if (varp->vval.v_string != NULL)
5592 		return varp->vval.v_string;
5593 	    return (char_u *)"";
5594 	case VAR_SPECIAL:
5595 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
5596 	    return buf;
5597         case VAR_BLOB:
5598 	    emsg(_("E976: using Blob as a String"));
5599 	    break;
5600 	case VAR_JOB:
5601 #ifdef FEAT_JOB_CHANNEL
5602 	    {
5603 		job_T *job = varp->vval.v_job;
5604 		char  *status;
5605 
5606 		if (job == NULL)
5607 		    return (char_u *)"no process";
5608 		status = job->jv_status == JOB_FAILED ? "fail"
5609 				: job->jv_status >= JOB_ENDED ? "dead"
5610 				: "run";
5611 # ifdef UNIX
5612 		vim_snprintf((char *)buf, NUMBUFLEN,
5613 			    "process %ld %s", (long)job->jv_pid, status);
5614 # elif defined(MSWIN)
5615 		vim_snprintf((char *)buf, NUMBUFLEN,
5616 			    "process %ld %s",
5617 			    (long)job->jv_proc_info.dwProcessId,
5618 			    status);
5619 # else
5620 		/* fall-back */
5621 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
5622 # endif
5623 		return buf;
5624 	    }
5625 #endif
5626 	    break;
5627 	case VAR_CHANNEL:
5628 #ifdef FEAT_JOB_CHANNEL
5629 	    {
5630 		channel_T *channel = varp->vval.v_channel;
5631 		char      *status = channel_status(channel, -1);
5632 
5633 		if (channel == NULL)
5634 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
5635 		else
5636 		    vim_snprintf((char *)buf, NUMBUFLEN,
5637 				     "channel %d %s", channel->ch_id, status);
5638 		return buf;
5639 	    }
5640 #endif
5641 	    break;
5642 	case VAR_UNKNOWN:
5643 	    emsg(_("E908: using an invalid value as a String"));
5644 	    break;
5645     }
5646     return NULL;
5647 }
5648 
5649 /*
5650  * Turn a typeval into a string.  Similar to tv_get_string_buf() but uses
5651  * string() on Dict, List, etc.
5652  */
5653     static char_u *
5654 tv_stringify(typval_T *varp, char_u *buf)
5655 {
5656     if (varp->v_type == VAR_LIST
5657 	    || varp->v_type == VAR_DICT
5658 	    || varp->v_type == VAR_FUNC
5659 	    || varp->v_type == VAR_PARTIAL
5660 	    || varp->v_type == VAR_FLOAT)
5661     {
5662 	typval_T tmp;
5663 
5664 	f_string(varp, &tmp);
5665 	tv_get_string_buf(&tmp, buf);
5666 	clear_tv(varp);
5667 	*varp = tmp;
5668 	return tmp.vval.v_string;
5669     }
5670     return tv_get_string_buf(varp, buf);
5671 }
5672 
5673 /*
5674  * Return TRUE if typeval "tv" and its value are set to be locked (immutable).
5675  * Also give an error message, using "name" or _("name") when use_gettext is
5676  * TRUE.
5677  */
5678     static int
5679 tv_check_lock(typval_T *tv, char_u *name, int use_gettext)
5680 {
5681     int	lock = 0;
5682 
5683     switch (tv->v_type)
5684     {
5685 	case VAR_BLOB:
5686 	    if (tv->vval.v_blob != NULL)
5687 		lock = tv->vval.v_blob->bv_lock;
5688 	    break;
5689 	case VAR_LIST:
5690 	    if (tv->vval.v_list != NULL)
5691 		lock = tv->vval.v_list->lv_lock;
5692 	    break;
5693 	case VAR_DICT:
5694 	    if (tv->vval.v_dict != NULL)
5695 		lock = tv->vval.v_dict->dv_lock;
5696 	    break;
5697 	default:
5698 	    break;
5699     }
5700     return var_check_lock(tv->v_lock, name, use_gettext)
5701 		    || (lock != 0 && var_check_lock(lock, name, use_gettext));
5702 }
5703 
5704 /*
5705  * Copy the values from typval_T "from" to typval_T "to".
5706  * When needed allocates string or increases reference count.
5707  * Does not make a copy of a list, blob or dict but copies the reference!
5708  * It is OK for "from" and "to" to point to the same item.  This is used to
5709  * make a copy later.
5710  */
5711     void
5712 copy_tv(typval_T *from, typval_T *to)
5713 {
5714     to->v_type = from->v_type;
5715     to->v_lock = 0;
5716     switch (from->v_type)
5717     {
5718 	case VAR_NUMBER:
5719 	case VAR_SPECIAL:
5720 	    to->vval.v_number = from->vval.v_number;
5721 	    break;
5722 	case VAR_FLOAT:
5723 #ifdef FEAT_FLOAT
5724 	    to->vval.v_float = from->vval.v_float;
5725 	    break;
5726 #endif
5727 	case VAR_JOB:
5728 #ifdef FEAT_JOB_CHANNEL
5729 	    to->vval.v_job = from->vval.v_job;
5730 	    if (to->vval.v_job != NULL)
5731 		++to->vval.v_job->jv_refcount;
5732 	    break;
5733 #endif
5734 	case VAR_CHANNEL:
5735 #ifdef FEAT_JOB_CHANNEL
5736 	    to->vval.v_channel = from->vval.v_channel;
5737 	    if (to->vval.v_channel != NULL)
5738 		++to->vval.v_channel->ch_refcount;
5739 	    break;
5740 #endif
5741 	case VAR_STRING:
5742 	case VAR_FUNC:
5743 	    if (from->vval.v_string == NULL)
5744 		to->vval.v_string = NULL;
5745 	    else
5746 	    {
5747 		to->vval.v_string = vim_strsave(from->vval.v_string);
5748 		if (from->v_type == VAR_FUNC)
5749 		    func_ref(to->vval.v_string);
5750 	    }
5751 	    break;
5752 	case VAR_PARTIAL:
5753 	    if (from->vval.v_partial == NULL)
5754 		to->vval.v_partial = NULL;
5755 	    else
5756 	    {
5757 		to->vval.v_partial = from->vval.v_partial;
5758 		++to->vval.v_partial->pt_refcount;
5759 	    }
5760 	    break;
5761 	case VAR_BLOB:
5762 	    if (from->vval.v_blob == NULL)
5763 		to->vval.v_blob = NULL;
5764 	    else
5765 	    {
5766 		to->vval.v_blob = from->vval.v_blob;
5767 		++to->vval.v_blob->bv_refcount;
5768 	    }
5769 	    break;
5770 	case VAR_LIST:
5771 	    if (from->vval.v_list == NULL)
5772 		to->vval.v_list = NULL;
5773 	    else
5774 	    {
5775 		to->vval.v_list = from->vval.v_list;
5776 		++to->vval.v_list->lv_refcount;
5777 	    }
5778 	    break;
5779 	case VAR_DICT:
5780 	    if (from->vval.v_dict == NULL)
5781 		to->vval.v_dict = NULL;
5782 	    else
5783 	    {
5784 		to->vval.v_dict = from->vval.v_dict;
5785 		++to->vval.v_dict->dv_refcount;
5786 	    }
5787 	    break;
5788 	case VAR_UNKNOWN:
5789 	    internal_error("copy_tv(UNKNOWN)");
5790 	    break;
5791     }
5792 }
5793 
5794 /*
5795  * Make a copy of an item.
5796  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5797  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5798  * reference to an already copied list/dict can be used.
5799  * Returns FAIL or OK.
5800  */
5801     int
5802 item_copy(
5803     typval_T	*from,
5804     typval_T	*to,
5805     int		deep,
5806     int		copyID)
5807 {
5808     static int	recurse = 0;
5809     int		ret = OK;
5810 
5811     if (recurse >= DICT_MAXNEST)
5812     {
5813 	emsg(_("E698: variable nested too deep for making a copy"));
5814 	return FAIL;
5815     }
5816     ++recurse;
5817 
5818     switch (from->v_type)
5819     {
5820 	case VAR_NUMBER:
5821 	case VAR_FLOAT:
5822 	case VAR_STRING:
5823 	case VAR_FUNC:
5824 	case VAR_PARTIAL:
5825 	case VAR_SPECIAL:
5826 	case VAR_JOB:
5827 	case VAR_CHANNEL:
5828 	    copy_tv(from, to);
5829 	    break;
5830 	case VAR_LIST:
5831 	    to->v_type = VAR_LIST;
5832 	    to->v_lock = 0;
5833 	    if (from->vval.v_list == NULL)
5834 		to->vval.v_list = NULL;
5835 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
5836 	    {
5837 		/* use the copy made earlier */
5838 		to->vval.v_list = from->vval.v_list->lv_copylist;
5839 		++to->vval.v_list->lv_refcount;
5840 	    }
5841 	    else
5842 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
5843 	    if (to->vval.v_list == NULL)
5844 		ret = FAIL;
5845 	    break;
5846 	case VAR_BLOB:
5847 	    ret = blob_copy(from, to);
5848 	    break;
5849 	case VAR_DICT:
5850 	    to->v_type = VAR_DICT;
5851 	    to->v_lock = 0;
5852 	    if (from->vval.v_dict == NULL)
5853 		to->vval.v_dict = NULL;
5854 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
5855 	    {
5856 		/* use the copy made earlier */
5857 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
5858 		++to->vval.v_dict->dv_refcount;
5859 	    }
5860 	    else
5861 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
5862 	    if (to->vval.v_dict == NULL)
5863 		ret = FAIL;
5864 	    break;
5865 	case VAR_UNKNOWN:
5866 	    internal_error("item_copy(UNKNOWN)");
5867 	    ret = FAIL;
5868     }
5869     --recurse;
5870     return ret;
5871 }
5872 
5873 /*
5874  * ":echo expr1 ..."	print each argument separated with a space, add a
5875  *			newline at the end.
5876  * ":echon expr1 ..."	print each argument plain.
5877  */
5878     void
5879 ex_echo(exarg_T *eap)
5880 {
5881     char_u	*arg = eap->arg;
5882     typval_T	rettv;
5883     char_u	*tofree;
5884     char_u	*p;
5885     int		needclr = TRUE;
5886     int		atstart = TRUE;
5887     char_u	numbuf[NUMBUFLEN];
5888     int		did_emsg_before = did_emsg;
5889     int		called_emsg_before = called_emsg;
5890 
5891     if (eap->skip)
5892 	++emsg_skip;
5893     while (*arg != NUL && *arg != '|' && *arg != '\n' && !got_int)
5894     {
5895 	/* If eval1() causes an error message the text from the command may
5896 	 * still need to be cleared. E.g., "echo 22,44". */
5897 	need_clr_eos = needclr;
5898 
5899 	p = arg;
5900 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
5901 	{
5902 	    /*
5903 	     * Report the invalid expression unless the expression evaluation
5904 	     * has been cancelled due to an aborting error, an interrupt, or an
5905 	     * exception.
5906 	     */
5907 	    if (!aborting() && did_emsg == did_emsg_before
5908 					  && called_emsg == called_emsg_before)
5909 		semsg(_(e_invexpr2), p);
5910 	    need_clr_eos = FALSE;
5911 	    break;
5912 	}
5913 	need_clr_eos = FALSE;
5914 
5915 	if (!eap->skip)
5916 	{
5917 	    if (atstart)
5918 	    {
5919 		atstart = FALSE;
5920 		/* Call msg_start() after eval1(), evaluating the expression
5921 		 * may cause a message to appear. */
5922 		if (eap->cmdidx == CMD_echo)
5923 		{
5924 		    /* Mark the saved text as finishing the line, so that what
5925 		     * follows is displayed on a new line when scrolling back
5926 		     * at the more prompt. */
5927 		    msg_sb_eol();
5928 		    msg_start();
5929 		}
5930 	    }
5931 	    else if (eap->cmdidx == CMD_echo)
5932 		msg_puts_attr(" ", echo_attr);
5933 	    p = echo_string(&rettv, &tofree, numbuf, get_copyID());
5934 	    if (p != NULL)
5935 		for ( ; *p != NUL && !got_int; ++p)
5936 		{
5937 		    if (*p == '\n' || *p == '\r' || *p == TAB)
5938 		    {
5939 			if (*p != TAB && needclr)
5940 			{
5941 			    /* remove any text still there from the command */
5942 			    msg_clr_eos();
5943 			    needclr = FALSE;
5944 			}
5945 			msg_putchar_attr(*p, echo_attr);
5946 		    }
5947 		    else
5948 		    {
5949 			if (has_mbyte)
5950 			{
5951 			    int i = (*mb_ptr2len)(p);
5952 
5953 			    (void)msg_outtrans_len_attr(p, i, echo_attr);
5954 			    p += i - 1;
5955 			}
5956 			else
5957 			    (void)msg_outtrans_len_attr(p, 1, echo_attr);
5958 		    }
5959 		}
5960 	    vim_free(tofree);
5961 	}
5962 	clear_tv(&rettv);
5963 	arg = skipwhite(arg);
5964     }
5965     eap->nextcmd = check_nextcmd(arg);
5966 
5967     if (eap->skip)
5968 	--emsg_skip;
5969     else
5970     {
5971 	/* remove text that may still be there from the command */
5972 	if (needclr)
5973 	    msg_clr_eos();
5974 	if (eap->cmdidx == CMD_echo)
5975 	    msg_end();
5976     }
5977 }
5978 
5979 /*
5980  * ":echohl {name}".
5981  */
5982     void
5983 ex_echohl(exarg_T *eap)
5984 {
5985     echo_attr = syn_name2attr(eap->arg);
5986 }
5987 
5988 /*
5989  * Returns the :echo attribute
5990  */
5991     int
5992 get_echo_attr(void)
5993 {
5994     return echo_attr;
5995 }
5996 
5997 /*
5998  * ":execute expr1 ..."	execute the result of an expression.
5999  * ":echomsg expr1 ..."	Print a message
6000  * ":echoerr expr1 ..."	Print an error
6001  * Each gets spaces around each argument and a newline at the end for
6002  * echo commands
6003  */
6004     void
6005 ex_execute(exarg_T *eap)
6006 {
6007     char_u	*arg = eap->arg;
6008     typval_T	rettv;
6009     int		ret = OK;
6010     char_u	*p;
6011     garray_T	ga;
6012     int		len;
6013     int		save_did_emsg;
6014 
6015     ga_init2(&ga, 1, 80);
6016 
6017     if (eap->skip)
6018 	++emsg_skip;
6019     while (*arg != NUL && *arg != '|' && *arg != '\n')
6020     {
6021 	ret = eval1_emsg(&arg, &rettv, !eap->skip);
6022 	if (ret == FAIL)
6023 	    break;
6024 
6025 	if (!eap->skip)
6026 	{
6027 	    char_u   buf[NUMBUFLEN];
6028 
6029 	    if (eap->cmdidx == CMD_execute)
6030 		p = tv_get_string_buf(&rettv, buf);
6031 	    else
6032 		p = tv_stringify(&rettv, buf);
6033 	    len = (int)STRLEN(p);
6034 	    if (ga_grow(&ga, len + 2) == FAIL)
6035 	    {
6036 		clear_tv(&rettv);
6037 		ret = FAIL;
6038 		break;
6039 	    }
6040 	    if (ga.ga_len)
6041 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
6042 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
6043 	    ga.ga_len += len;
6044 	}
6045 
6046 	clear_tv(&rettv);
6047 	arg = skipwhite(arg);
6048     }
6049 
6050     if (ret != FAIL && ga.ga_data != NULL)
6051     {
6052 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
6053 	{
6054 	    /* Mark the already saved text as finishing the line, so that what
6055 	     * follows is displayed on a new line when scrolling back at the
6056 	     * more prompt. */
6057 	    msg_sb_eol();
6058 	}
6059 
6060 	if (eap->cmdidx == CMD_echomsg)
6061 	{
6062 	    msg_attr(ga.ga_data, echo_attr);
6063 	    out_flush();
6064 	}
6065 	else if (eap->cmdidx == CMD_echoerr)
6066 	{
6067 	    /* We don't want to abort following commands, restore did_emsg. */
6068 	    save_did_emsg = did_emsg;
6069 	    emsg(ga.ga_data);
6070 	    if (!force_abort)
6071 		did_emsg = save_did_emsg;
6072 	}
6073 	else if (eap->cmdidx == CMD_execute)
6074 	    do_cmdline((char_u *)ga.ga_data,
6075 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
6076     }
6077 
6078     ga_clear(&ga);
6079 
6080     if (eap->skip)
6081 	--emsg_skip;
6082 
6083     eap->nextcmd = check_nextcmd(arg);
6084 }
6085 
6086 /*
6087  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
6088  * "arg" points to the "&" or '+' when called, to "option" when returning.
6089  * Returns NULL when no option name found.  Otherwise pointer to the char
6090  * after the option name.
6091  */
6092     char_u *
6093 find_option_end(char_u **arg, int *opt_flags)
6094 {
6095     char_u	*p = *arg;
6096 
6097     ++p;
6098     if (*p == 'g' && p[1] == ':')
6099     {
6100 	*opt_flags = OPT_GLOBAL;
6101 	p += 2;
6102     }
6103     else if (*p == 'l' && p[1] == ':')
6104     {
6105 	*opt_flags = OPT_LOCAL;
6106 	p += 2;
6107     }
6108     else
6109 	*opt_flags = 0;
6110 
6111     if (!ASCII_ISALPHA(*p))
6112 	return NULL;
6113     *arg = p;
6114 
6115     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
6116 	p += 4;	    /* termcap option */
6117     else
6118 	while (ASCII_ISALPHA(*p))
6119 	    ++p;
6120     return p;
6121 }
6122 
6123 /*
6124  * Display script name where an item was last set.
6125  * Should only be invoked when 'verbose' is non-zero.
6126  */
6127     void
6128 last_set_msg(sctx_T script_ctx)
6129 {
6130     char_u *p;
6131 
6132     if (script_ctx.sc_sid != 0)
6133     {
6134 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
6135 	if (p != NULL)
6136 	{
6137 	    verbose_enter();
6138 	    msg_puts(_("\n\tLast set from "));
6139 	    msg_puts((char *)p);
6140 	    if (script_ctx.sc_lnum > 0)
6141 	    {
6142 		msg_puts(_(" line "));
6143 		msg_outnum((long)script_ctx.sc_lnum);
6144 	    }
6145 	    verbose_leave();
6146 	    vim_free(p);
6147 	}
6148     }
6149 }
6150 
6151 /*
6152  * Compare "typ1" and "typ2".  Put the result in "typ1".
6153  */
6154     int
6155 typval_compare(
6156     typval_T	*typ1,   /* first operand */
6157     typval_T	*typ2,   /* second operand */
6158     exptype_T	type,    /* operator */
6159     int		type_is, /* TRUE for "is" and "isnot" */
6160     int		ic)      /* ignore case */
6161 {
6162     int		i;
6163     varnumber_T	n1, n2;
6164     char_u	*s1, *s2;
6165     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
6166 
6167     if (type_is && typ1->v_type != typ2->v_type)
6168     {
6169 	/* For "is" a different type always means FALSE, for "notis"
6170 	    * it means TRUE. */
6171 	n1 = (type == TYPE_NEQUAL);
6172     }
6173     else if (typ1->v_type == VAR_BLOB || typ2->v_type == VAR_BLOB)
6174     {
6175 	if (type_is)
6176 	{
6177 	    n1 = (typ1->v_type == typ2->v_type
6178 			    && typ1->vval.v_blob == typ2->vval.v_blob);
6179 	    if (type == TYPE_NEQUAL)
6180 		n1 = !n1;
6181 	}
6182 	else if (typ1->v_type != typ2->v_type
6183 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
6184 	{
6185 	    if (typ1->v_type != typ2->v_type)
6186 		emsg(_("E977: Can only compare Blob with Blob"));
6187 	    else
6188 		emsg(_(e_invalblob));
6189 	    clear_tv(typ1);
6190 	    return FAIL;
6191 	}
6192 	else
6193 	{
6194 	    // Compare two Blobs for being equal or unequal.
6195 	    n1 = blob_equal(typ1->vval.v_blob, typ2->vval.v_blob);
6196 	    if (type == TYPE_NEQUAL)
6197 		n1 = !n1;
6198 	}
6199     }
6200     else if (typ1->v_type == VAR_LIST || typ2->v_type == VAR_LIST)
6201     {
6202 	if (type_is)
6203 	{
6204 	    n1 = (typ1->v_type == typ2->v_type
6205 			    && typ1->vval.v_list == typ2->vval.v_list);
6206 	    if (type == TYPE_NEQUAL)
6207 		n1 = !n1;
6208 	}
6209 	else if (typ1->v_type != typ2->v_type
6210 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
6211 	{
6212 	    if (typ1->v_type != typ2->v_type)
6213 		emsg(_("E691: Can only compare List with List"));
6214 	    else
6215 		emsg(_("E692: Invalid operation for List"));
6216 	    clear_tv(typ1);
6217 	    return FAIL;
6218 	}
6219 	else
6220 	{
6221 	    /* Compare two Lists for being equal or unequal. */
6222 	    n1 = list_equal(typ1->vval.v_list, typ2->vval.v_list,
6223 							    ic, FALSE);
6224 	    if (type == TYPE_NEQUAL)
6225 		n1 = !n1;
6226 	}
6227     }
6228 
6229     else if (typ1->v_type == VAR_DICT || typ2->v_type == VAR_DICT)
6230     {
6231 	if (type_is)
6232 	{
6233 	    n1 = (typ1->v_type == typ2->v_type
6234 			    && typ1->vval.v_dict == typ2->vval.v_dict);
6235 	    if (type == TYPE_NEQUAL)
6236 		n1 = !n1;
6237 	}
6238 	else if (typ1->v_type != typ2->v_type
6239 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
6240 	{
6241 	    if (typ1->v_type != typ2->v_type)
6242 		emsg(_("E735: Can only compare Dictionary with Dictionary"));
6243 	    else
6244 		emsg(_("E736: Invalid operation for Dictionary"));
6245 	    clear_tv(typ1);
6246 	    return FAIL;
6247 	}
6248 	else
6249 	{
6250 	    /* Compare two Dictionaries for being equal or unequal. */
6251 	    n1 = dict_equal(typ1->vval.v_dict, typ2->vval.v_dict,
6252 							    ic, FALSE);
6253 	    if (type == TYPE_NEQUAL)
6254 		n1 = !n1;
6255 	}
6256     }
6257 
6258     else if (typ1->v_type == VAR_FUNC || typ2->v_type == VAR_FUNC
6259 	|| typ1->v_type == VAR_PARTIAL || typ2->v_type == VAR_PARTIAL)
6260     {
6261 	if (type != TYPE_EQUAL && type != TYPE_NEQUAL)
6262 	{
6263 	    emsg(_("E694: Invalid operation for Funcrefs"));
6264 	    clear_tv(typ1);
6265 	    return FAIL;
6266 	}
6267 	if ((typ1->v_type == VAR_PARTIAL
6268 					&& typ1->vval.v_partial == NULL)
6269 		|| (typ2->v_type == VAR_PARTIAL
6270 					&& typ2->vval.v_partial == NULL))
6271 	    /* when a partial is NULL assume not equal */
6272 	    n1 = FALSE;
6273 	else if (type_is)
6274 	{
6275 	    if (typ1->v_type == VAR_FUNC && typ2->v_type == VAR_FUNC)
6276 		/* strings are considered the same if their value is
6277 		    * the same */
6278 		n1 = tv_equal(typ1, typ2, ic, FALSE);
6279 	    else if (typ1->v_type == VAR_PARTIAL
6280 					&& typ2->v_type == VAR_PARTIAL)
6281 		n1 = (typ1->vval.v_partial == typ2->vval.v_partial);
6282 	    else
6283 		n1 = FALSE;
6284 	}
6285 	else
6286 	    n1 = tv_equal(typ1, typ2, ic, FALSE);
6287 	if (type == TYPE_NEQUAL)
6288 	    n1 = !n1;
6289     }
6290 
6291 #ifdef FEAT_FLOAT
6292     /*
6293 	* If one of the two variables is a float, compare as a float.
6294 	* When using "=~" or "!~", always compare as string.
6295 	*/
6296     else if ((typ1->v_type == VAR_FLOAT || typ2->v_type == VAR_FLOAT)
6297 	    && type != TYPE_MATCH && type != TYPE_NOMATCH)
6298     {
6299 	float_T f1, f2;
6300 
6301 	f1 = tv_get_float(typ1);
6302 	f2 = tv_get_float(typ2);
6303 	n1 = FALSE;
6304 	switch (type)
6305 	{
6306 	    case TYPE_EQUAL:    n1 = (f1 == f2); break;
6307 	    case TYPE_NEQUAL:   n1 = (f1 != f2); break;
6308 	    case TYPE_GREATER:  n1 = (f1 > f2); break;
6309 	    case TYPE_GEQUAL:   n1 = (f1 >= f2); break;
6310 	    case TYPE_SMALLER:  n1 = (f1 < f2); break;
6311 	    case TYPE_SEQUAL:   n1 = (f1 <= f2); break;
6312 	    case TYPE_UNKNOWN:
6313 	    case TYPE_MATCH:
6314 	    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
6315 	}
6316     }
6317 #endif
6318 
6319     /*
6320 	* If one of the two variables is a number, compare as a number.
6321 	* When using "=~" or "!~", always compare as string.
6322 	*/
6323     else if ((typ1->v_type == VAR_NUMBER || typ2->v_type == VAR_NUMBER)
6324 	    && type != TYPE_MATCH && type != TYPE_NOMATCH)
6325     {
6326 	n1 = tv_get_number(typ1);
6327 	n2 = tv_get_number(typ2);
6328 	switch (type)
6329 	{
6330 	    case TYPE_EQUAL:    n1 = (n1 == n2); break;
6331 	    case TYPE_NEQUAL:   n1 = (n1 != n2); break;
6332 	    case TYPE_GREATER:  n1 = (n1 > n2); break;
6333 	    case TYPE_GEQUAL:   n1 = (n1 >= n2); break;
6334 	    case TYPE_SMALLER:  n1 = (n1 < n2); break;
6335 	    case TYPE_SEQUAL:   n1 = (n1 <= n2); break;
6336 	    case TYPE_UNKNOWN:
6337 	    case TYPE_MATCH:
6338 	    case TYPE_NOMATCH:  break;  /* avoid gcc warning */
6339 	}
6340     }
6341     else
6342     {
6343 	s1 = tv_get_string_buf(typ1, buf1);
6344 	s2 = tv_get_string_buf(typ2, buf2);
6345 	if (type != TYPE_MATCH && type != TYPE_NOMATCH)
6346 	    i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
6347 	else
6348 	    i = 0;
6349 	n1 = FALSE;
6350 	switch (type)
6351 	{
6352 	    case TYPE_EQUAL:    n1 = (i == 0); break;
6353 	    case TYPE_NEQUAL:   n1 = (i != 0); break;
6354 	    case TYPE_GREATER:  n1 = (i > 0); break;
6355 	    case TYPE_GEQUAL:   n1 = (i >= 0); break;
6356 	    case TYPE_SMALLER:  n1 = (i < 0); break;
6357 	    case TYPE_SEQUAL:   n1 = (i <= 0); break;
6358 
6359 	    case TYPE_MATCH:
6360 	    case TYPE_NOMATCH:
6361 		    n1 = pattern_match(s2, s1, ic);
6362 		    if (type == TYPE_NOMATCH)
6363 			n1 = !n1;
6364 		    break;
6365 
6366 	    case TYPE_UNKNOWN:  break;  /* avoid gcc warning */
6367 	}
6368     }
6369     clear_tv(typ1);
6370     typ1->v_type = VAR_NUMBER;
6371     typ1->vval.v_number = n1;
6372 
6373     return OK;
6374 }
6375 
6376     char_u *
6377 typval_tostring(typval_T *arg)
6378 {
6379     char_u	*tofree;
6380     char_u	numbuf[NUMBUFLEN];
6381     char_u	*ret = NULL;
6382 
6383     if (arg == NULL)
6384 	return vim_strsave((char_u *)"(does not exist)");
6385     ret = tv2string(arg, &tofree, numbuf, 0);
6386     /* Make a copy if we have a value but it's not in allocated memory. */
6387     if (ret != NULL && tofree == NULL)
6388 	ret = vim_strsave(ret);
6389     return ret;
6390 }
6391 
6392 #endif // FEAT_EVAL
6393 
6394 /*
6395  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
6396  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
6397  * "flags" can be "g" to do a global substitute.
6398  * Returns an allocated string, NULL for error.
6399  */
6400     char_u *
6401 do_string_sub(
6402     char_u	*str,
6403     char_u	*pat,
6404     char_u	*sub,
6405     typval_T	*expr,
6406     char_u	*flags)
6407 {
6408     int		sublen;
6409     regmatch_T	regmatch;
6410     int		i;
6411     int		do_all;
6412     char_u	*tail;
6413     char_u	*end;
6414     garray_T	ga;
6415     char_u	*ret;
6416     char_u	*save_cpo;
6417     char_u	*zero_width = NULL;
6418 
6419     /* Make 'cpoptions' empty, so that the 'l' flag doesn't work here */
6420     save_cpo = p_cpo;
6421     p_cpo = empty_option;
6422 
6423     ga_init2(&ga, 1, 200);
6424 
6425     do_all = (flags[0] == 'g');
6426 
6427     regmatch.rm_ic = p_ic;
6428     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
6429     if (regmatch.regprog != NULL)
6430     {
6431 	tail = str;
6432 	end = str + STRLEN(str);
6433 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
6434 	{
6435 	    /* Skip empty match except for first match. */
6436 	    if (regmatch.startp[0] == regmatch.endp[0])
6437 	    {
6438 		if (zero_width == regmatch.startp[0])
6439 		{
6440 		    /* avoid getting stuck on a match with an empty string */
6441 		    i = MB_PTR2LEN(tail);
6442 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
6443 								   (size_t)i);
6444 		    ga.ga_len += i;
6445 		    tail += i;
6446 		    continue;
6447 		}
6448 		zero_width = regmatch.startp[0];
6449 	    }
6450 
6451 	    /*
6452 	     * Get some space for a temporary buffer to do the substitution
6453 	     * into.  It will contain:
6454 	     * - The text up to where the match is.
6455 	     * - The substituted text.
6456 	     * - The text after the match.
6457 	     */
6458 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
6459 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
6460 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
6461 	    {
6462 		ga_clear(&ga);
6463 		break;
6464 	    }
6465 
6466 	    /* copy the text up to where the match is */
6467 	    i = (int)(regmatch.startp[0] - tail);
6468 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
6469 	    /* add the substituted text */
6470 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
6471 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
6472 	    ga.ga_len += i + sublen - 1;
6473 	    tail = regmatch.endp[0];
6474 	    if (*tail == NUL)
6475 		break;
6476 	    if (!do_all)
6477 		break;
6478 	}
6479 
6480 	if (ga.ga_data != NULL)
6481 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
6482 
6483 	vim_regfree(regmatch.regprog);
6484     }
6485 
6486     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
6487     ga_clear(&ga);
6488     if (p_cpo == empty_option)
6489 	p_cpo = save_cpo;
6490     else
6491 	/* Darn, evaluating {sub} expression or {expr} changed the value. */
6492 	free_string_option(save_cpo);
6493 
6494     return ret;
6495 }
6496