xref: /vim-8.2.3635/src/eval.c (revision 469bdbde)
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 || cmdidx == CMD_const)
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 != OK)
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 	ret = FAIL;
2918     }
2919     else
2920 	ret = call_func_rettv(arg, rettv, evaluate, NULL, &base);
2921 
2922     // Clear the funcref afterwards, so that deleting it while
2923     // evaluating the arguments is possible (see test55).
2924     if (evaluate)
2925 	clear_tv(&base);
2926 
2927     return ret;
2928 }
2929 
2930 /*
2931  * Evaluate "->method()".
2932  * "*arg" points to the '-'.
2933  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
2934  */
2935     static int
2936 eval_method(
2937     char_u	**arg,
2938     typval_T	*rettv,
2939     int		evaluate,
2940     int		verbose)	// give error messages
2941 {
2942     char_u	*name;
2943     long	len;
2944     char_u	*alias;
2945     typval_T	base = *rettv;
2946     int		ret;
2947 
2948     // Skip over the ->.
2949     *arg += 2;
2950     rettv->v_type = VAR_UNKNOWN;
2951 
2952     name = *arg;
2953     len = get_name_len(arg, &alias, evaluate, TRUE);
2954     if (alias != NULL)
2955 	name = alias;
2956 
2957     if (len <= 0)
2958     {
2959 	if (verbose)
2960 	    emsg(_("E260: Missing name after ->"));
2961 	ret = FAIL;
2962     }
2963     else
2964     {
2965 	if (**arg != '(')
2966 	{
2967 	    if (verbose)
2968 		semsg(_(e_missingparen), name);
2969 	    ret = FAIL;
2970 	}
2971 	else if (VIM_ISWHITE((*arg)[-1]))
2972 	{
2973 	    if (verbose)
2974 		semsg(_(e_nowhitespace));
2975 	    ret = FAIL;
2976 	}
2977 	else
2978 	    ret = eval_func(arg, name, len, rettv, evaluate, &base);
2979     }
2980 
2981     // Clear the funcref afterwards, so that deleting it while
2982     // evaluating the arguments is possible (see test55).
2983     if (evaluate)
2984 	clear_tv(&base);
2985 
2986     return ret;
2987 }
2988 
2989 /*
2990  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
2991  * "*arg" points to the '[' or '.'.
2992  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
2993  */
2994     static int
2995 eval_index(
2996     char_u	**arg,
2997     typval_T	*rettv,
2998     int		evaluate,
2999     int		verbose)	// give error messages
3000 {
3001     int		empty1 = FALSE, empty2 = FALSE;
3002     typval_T	var1, var2;
3003     long	i;
3004     long	n1, n2 = 0;
3005     long	len = -1;
3006     int		range = FALSE;
3007     char_u	*s;
3008     char_u	*key = NULL;
3009 
3010     switch (rettv->v_type)
3011     {
3012 	case VAR_FUNC:
3013 	case VAR_PARTIAL:
3014 	    if (verbose)
3015 		emsg(_("E695: Cannot index a Funcref"));
3016 	    return FAIL;
3017 	case VAR_FLOAT:
3018 #ifdef FEAT_FLOAT
3019 	    if (verbose)
3020 		emsg(_(e_float_as_string));
3021 	    return FAIL;
3022 #endif
3023 	case VAR_SPECIAL:
3024 	case VAR_JOB:
3025 	case VAR_CHANNEL:
3026 	    if (verbose)
3027 		emsg(_("E909: Cannot index a special variable"));
3028 	    return FAIL;
3029 	case VAR_UNKNOWN:
3030 	    if (evaluate)
3031 		return FAIL;
3032 	    // FALLTHROUGH
3033 
3034 	case VAR_STRING:
3035 	case VAR_NUMBER:
3036 	case VAR_LIST:
3037 	case VAR_DICT:
3038 	case VAR_BLOB:
3039 	    break;
3040     }
3041 
3042     init_tv(&var1);
3043     init_tv(&var2);
3044     if (**arg == '.')
3045     {
3046 	/*
3047 	 * dict.name
3048 	 */
3049 	key = *arg + 1;
3050 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
3051 	    ;
3052 	if (len == 0)
3053 	    return FAIL;
3054 	*arg = skipwhite(key + len);
3055     }
3056     else
3057     {
3058 	/*
3059 	 * something[idx]
3060 	 *
3061 	 * Get the (first) variable from inside the [].
3062 	 */
3063 	*arg = skipwhite(*arg + 1);
3064 	if (**arg == ':')
3065 	    empty1 = TRUE;
3066 	else if (eval1(arg, &var1, evaluate) == FAIL)	// recursive!
3067 	    return FAIL;
3068 	else if (evaluate && tv_get_string_chk(&var1) == NULL)
3069 	{
3070 	    // not a number or string
3071 	    clear_tv(&var1);
3072 	    return FAIL;
3073 	}
3074 
3075 	/*
3076 	 * Get the second variable from inside the [:].
3077 	 */
3078 	if (**arg == ':')
3079 	{
3080 	    range = TRUE;
3081 	    *arg = skipwhite(*arg + 1);
3082 	    if (**arg == ']')
3083 		empty2 = TRUE;
3084 	    else if (eval1(arg, &var2, evaluate) == FAIL)	// recursive!
3085 	    {
3086 		if (!empty1)
3087 		    clear_tv(&var1);
3088 		return FAIL;
3089 	    }
3090 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
3091 	    {
3092 		// not a number or string
3093 		if (!empty1)
3094 		    clear_tv(&var1);
3095 		clear_tv(&var2);
3096 		return FAIL;
3097 	    }
3098 	}
3099 
3100 	// Check for the ']'.
3101 	if (**arg != ']')
3102 	{
3103 	    if (verbose)
3104 		emsg(_(e_missbrac));
3105 	    clear_tv(&var1);
3106 	    if (range)
3107 		clear_tv(&var2);
3108 	    return FAIL;
3109 	}
3110 	*arg = skipwhite(*arg + 1);	// skip the ']'
3111     }
3112 
3113     if (evaluate)
3114     {
3115 	n1 = 0;
3116 	if (!empty1 && rettv->v_type != VAR_DICT)
3117 	{
3118 	    n1 = tv_get_number(&var1);
3119 	    clear_tv(&var1);
3120 	}
3121 	if (range)
3122 	{
3123 	    if (empty2)
3124 		n2 = -1;
3125 	    else
3126 	    {
3127 		n2 = tv_get_number(&var2);
3128 		clear_tv(&var2);
3129 	    }
3130 	}
3131 
3132 	switch (rettv->v_type)
3133 	{
3134 	    case VAR_UNKNOWN:
3135 	    case VAR_FUNC:
3136 	    case VAR_PARTIAL:
3137 	    case VAR_FLOAT:
3138 	    case VAR_SPECIAL:
3139 	    case VAR_JOB:
3140 	    case VAR_CHANNEL:
3141 		break; // not evaluating, skipping over subscript
3142 
3143 	    case VAR_NUMBER:
3144 	    case VAR_STRING:
3145 		s = tv_get_string(rettv);
3146 		len = (long)STRLEN(s);
3147 		if (range)
3148 		{
3149 		    // The resulting variable is a substring.  If the indexes
3150 		    // are out of range the result is empty.
3151 		    if (n1 < 0)
3152 		    {
3153 			n1 = len + n1;
3154 			if (n1 < 0)
3155 			    n1 = 0;
3156 		    }
3157 		    if (n2 < 0)
3158 			n2 = len + n2;
3159 		    else if (n2 >= len)
3160 			n2 = len;
3161 		    if (n1 >= len || n2 < 0 || n1 > n2)
3162 			s = NULL;
3163 		    else
3164 			s = vim_strnsave(s + n1, (int)(n2 - n1 + 1));
3165 		}
3166 		else
3167 		{
3168 		    // The resulting variable is a string of a single
3169 		    // character.  If the index is too big or negative the
3170 		    // result is empty.
3171 		    if (n1 >= len || n1 < 0)
3172 			s = NULL;
3173 		    else
3174 			s = vim_strnsave(s + n1, 1);
3175 		}
3176 		clear_tv(rettv);
3177 		rettv->v_type = VAR_STRING;
3178 		rettv->vval.v_string = s;
3179 		break;
3180 
3181 	    case VAR_BLOB:
3182 		len = blob_len(rettv->vval.v_blob);
3183 		if (range)
3184 		{
3185 		    // The resulting variable is a sub-blob.  If the indexes
3186 		    // are out of range the result is empty.
3187 		    if (n1 < 0)
3188 		    {
3189 			n1 = len + n1;
3190 			if (n1 < 0)
3191 			    n1 = 0;
3192 		    }
3193 		    if (n2 < 0)
3194 			n2 = len + n2;
3195 		    else if (n2 >= len)
3196 			n2 = len - 1;
3197 		    if (n1 >= len || n2 < 0 || n1 > n2)
3198 		    {
3199 			clear_tv(rettv);
3200 			rettv->v_type = VAR_BLOB;
3201 			rettv->vval.v_blob = NULL;
3202 		    }
3203 		    else
3204 		    {
3205 			blob_T  *blob = blob_alloc();
3206 
3207 			if (blob != NULL)
3208 			{
3209 			    if (ga_grow(&blob->bv_ga, n2 - n1 + 1) == FAIL)
3210 			    {
3211 				blob_free(blob);
3212 				return FAIL;
3213 			    }
3214 			    blob->bv_ga.ga_len = n2 - n1 + 1;
3215 			    for (i = n1; i <= n2; i++)
3216 				blob_set(blob, i - n1,
3217 					      blob_get(rettv->vval.v_blob, i));
3218 
3219 			    clear_tv(rettv);
3220 			    rettv_blob_set(rettv, blob);
3221 			}
3222 		    }
3223 		}
3224 		else
3225 		{
3226 		    // The resulting variable is a byte value.
3227 		    // If the index is too big or negative that is an error.
3228 		    if (n1 < 0)
3229 			n1 = len + n1;
3230 		    if (n1 < len && n1 >= 0)
3231 		    {
3232 			int v = blob_get(rettv->vval.v_blob, n1);
3233 
3234 			clear_tv(rettv);
3235 			rettv->v_type = VAR_NUMBER;
3236 			rettv->vval.v_number = v;
3237 		    }
3238 		    else
3239 			semsg(_(e_blobidx), n1);
3240 		}
3241 		break;
3242 
3243 	    case VAR_LIST:
3244 		len = list_len(rettv->vval.v_list);
3245 		if (n1 < 0)
3246 		    n1 = len + n1;
3247 		if (!empty1 && (n1 < 0 || n1 >= len))
3248 		{
3249 		    // For a range we allow invalid values and return an empty
3250 		    // list.  A list index out of range is an error.
3251 		    if (!range)
3252 		    {
3253 			if (verbose)
3254 			    semsg(_(e_listidx), n1);
3255 			return FAIL;
3256 		    }
3257 		    n1 = len;
3258 		}
3259 		if (range)
3260 		{
3261 		    list_T	*l;
3262 		    listitem_T	*item;
3263 
3264 		    if (n2 < 0)
3265 			n2 = len + n2;
3266 		    else if (n2 >= len)
3267 			n2 = len - 1;
3268 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
3269 			n2 = -1;
3270 		    l = list_alloc();
3271 		    if (l == NULL)
3272 			return FAIL;
3273 		    for (item = list_find(rettv->vval.v_list, n1);
3274 							       n1 <= n2; ++n1)
3275 		    {
3276 			if (list_append_tv(l, &item->li_tv) == FAIL)
3277 			{
3278 			    list_free(l);
3279 			    return FAIL;
3280 			}
3281 			item = item->li_next;
3282 		    }
3283 		    clear_tv(rettv);
3284 		    rettv_list_set(rettv, l);
3285 		}
3286 		else
3287 		{
3288 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
3289 		    clear_tv(rettv);
3290 		    *rettv = var1;
3291 		}
3292 		break;
3293 
3294 	    case VAR_DICT:
3295 		if (range)
3296 		{
3297 		    if (verbose)
3298 			emsg(_(e_dictrange));
3299 		    if (len == -1)
3300 			clear_tv(&var1);
3301 		    return FAIL;
3302 		}
3303 		{
3304 		    dictitem_T	*item;
3305 
3306 		    if (len == -1)
3307 		    {
3308 			key = tv_get_string_chk(&var1);
3309 			if (key == NULL)
3310 			{
3311 			    clear_tv(&var1);
3312 			    return FAIL;
3313 			}
3314 		    }
3315 
3316 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
3317 
3318 		    if (item == NULL && verbose)
3319 			semsg(_(e_dictkey), key);
3320 		    if (len == -1)
3321 			clear_tv(&var1);
3322 		    if (item == NULL)
3323 			return FAIL;
3324 
3325 		    copy_tv(&item->di_tv, &var1);
3326 		    clear_tv(rettv);
3327 		    *rettv = var1;
3328 		}
3329 		break;
3330 	}
3331     }
3332 
3333     return OK;
3334 }
3335 
3336 /*
3337  * Get an option value.
3338  * "arg" points to the '&' or '+' before the option name.
3339  * "arg" is advanced to character after the option name.
3340  * Return OK or FAIL.
3341  */
3342     int
3343 get_option_tv(
3344     char_u	**arg,
3345     typval_T	*rettv,	// when NULL, only check if option exists
3346     int		evaluate)
3347 {
3348     char_u	*option_end;
3349     long	numval;
3350     char_u	*stringval;
3351     int		opt_type;
3352     int		c;
3353     int		working = (**arg == '+');    // has("+option")
3354     int		ret = OK;
3355     int		opt_flags;
3356 
3357     /*
3358      * Isolate the option name and find its value.
3359      */
3360     option_end = find_option_end(arg, &opt_flags);
3361     if (option_end == NULL)
3362     {
3363 	if (rettv != NULL)
3364 	    semsg(_("E112: Option name missing: %s"), *arg);
3365 	return FAIL;
3366     }
3367 
3368     if (!evaluate)
3369     {
3370 	*arg = option_end;
3371 	return OK;
3372     }
3373 
3374     c = *option_end;
3375     *option_end = NUL;
3376     opt_type = get_option_value(*arg, &numval,
3377 			       rettv == NULL ? NULL : &stringval, opt_flags);
3378 
3379     if (opt_type == -3)			// invalid name
3380     {
3381 	if (rettv != NULL)
3382 	    semsg(_("E113: Unknown option: %s"), *arg);
3383 	ret = FAIL;
3384     }
3385     else if (rettv != NULL)
3386     {
3387 	if (opt_type == -2)		// hidden string option
3388 	{
3389 	    rettv->v_type = VAR_STRING;
3390 	    rettv->vval.v_string = NULL;
3391 	}
3392 	else if (opt_type == -1)	// hidden number option
3393 	{
3394 	    rettv->v_type = VAR_NUMBER;
3395 	    rettv->vval.v_number = 0;
3396 	}
3397 	else if (opt_type == 1)		// number option
3398 	{
3399 	    rettv->v_type = VAR_NUMBER;
3400 	    rettv->vval.v_number = numval;
3401 	}
3402 	else				// string option
3403 	{
3404 	    rettv->v_type = VAR_STRING;
3405 	    rettv->vval.v_string = stringval;
3406 	}
3407     }
3408     else if (working && (opt_type == -2 || opt_type == -1))
3409 	ret = FAIL;
3410 
3411     *option_end = c;		    // put back for error messages
3412     *arg = option_end;
3413 
3414     return ret;
3415 }
3416 
3417 /*
3418  * Allocate a variable for a string constant.
3419  * Return OK or FAIL.
3420  */
3421     static int
3422 get_string_tv(char_u **arg, typval_T *rettv, int evaluate)
3423 {
3424     char_u	*p;
3425     char_u	*name;
3426     int		extra = 0;
3427 
3428     /*
3429      * Find the end of the string, skipping backslashed characters.
3430      */
3431     for (p = *arg + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
3432     {
3433 	if (*p == '\\' && p[1] != NUL)
3434 	{
3435 	    ++p;
3436 	    // A "\<x>" form occupies at least 4 characters, and produces up
3437 	    // to 6 characters: reserve space for 2 extra
3438 	    if (*p == '<')
3439 		extra += 2;
3440 	}
3441     }
3442 
3443     if (*p != '"')
3444     {
3445 	semsg(_("E114: Missing quote: %s"), *arg);
3446 	return FAIL;
3447     }
3448 
3449     // If only parsing, set *arg and return here
3450     if (!evaluate)
3451     {
3452 	*arg = p + 1;
3453 	return OK;
3454     }
3455 
3456     /*
3457      * Copy the string into allocated memory, handling backslashed
3458      * characters.
3459      */
3460     name = alloc(p - *arg + extra);
3461     if (name == NULL)
3462 	return FAIL;
3463     rettv->v_type = VAR_STRING;
3464     rettv->vval.v_string = name;
3465 
3466     for (p = *arg + 1; *p != NUL && *p != '"'; )
3467     {
3468 	if (*p == '\\')
3469 	{
3470 	    switch (*++p)
3471 	    {
3472 		case 'b': *name++ = BS; ++p; break;
3473 		case 'e': *name++ = ESC; ++p; break;
3474 		case 'f': *name++ = FF; ++p; break;
3475 		case 'n': *name++ = NL; ++p; break;
3476 		case 'r': *name++ = CAR; ++p; break;
3477 		case 't': *name++ = TAB; ++p; break;
3478 
3479 		case 'X': // hex: "\x1", "\x12"
3480 		case 'x':
3481 		case 'u': // Unicode: "\u0023"
3482 		case 'U':
3483 			  if (vim_isxdigit(p[1]))
3484 			  {
3485 			      int	n, nr;
3486 			      int	c = toupper(*p);
3487 
3488 			      if (c == 'X')
3489 				  n = 2;
3490 			      else if (*p == 'u')
3491 				  n = 4;
3492 			      else
3493 				  n = 8;
3494 			      nr = 0;
3495 			      while (--n >= 0 && vim_isxdigit(p[1]))
3496 			      {
3497 				  ++p;
3498 				  nr = (nr << 4) + hex2nr(*p);
3499 			      }
3500 			      ++p;
3501 			      // For "\u" store the number according to
3502 			      // 'encoding'.
3503 			      if (c != 'X')
3504 				  name += (*mb_char2bytes)(nr, name);
3505 			      else
3506 				  *name++ = nr;
3507 			  }
3508 			  break;
3509 
3510 			  // octal: "\1", "\12", "\123"
3511 		case '0':
3512 		case '1':
3513 		case '2':
3514 		case '3':
3515 		case '4':
3516 		case '5':
3517 		case '6':
3518 		case '7': *name = *p++ - '0';
3519 			  if (*p >= '0' && *p <= '7')
3520 			  {
3521 			      *name = (*name << 3) + *p++ - '0';
3522 			      if (*p >= '0' && *p <= '7')
3523 				  *name = (*name << 3) + *p++ - '0';
3524 			  }
3525 			  ++name;
3526 			  break;
3527 
3528 			    // Special key, e.g.: "\<C-W>"
3529 		case '<': extra = trans_special(&p, name, TRUE, TRUE,
3530 								   TRUE, NULL);
3531 			  if (extra != 0)
3532 			  {
3533 			      name += extra;
3534 			      break;
3535 			  }
3536 			  // FALLTHROUGH
3537 
3538 		default:  MB_COPY_CHAR(p, name);
3539 			  break;
3540 	    }
3541 	}
3542 	else
3543 	    MB_COPY_CHAR(p, name);
3544 
3545     }
3546     *name = NUL;
3547     if (*p != NUL) // just in case
3548 	++p;
3549     *arg = p;
3550 
3551     return OK;
3552 }
3553 
3554 /*
3555  * Allocate a variable for a 'str''ing' constant.
3556  * Return OK or FAIL.
3557  */
3558     static int
3559 get_lit_string_tv(char_u **arg, typval_T *rettv, int evaluate)
3560 {
3561     char_u	*p;
3562     char_u	*str;
3563     int		reduce = 0;
3564 
3565     /*
3566      * Find the end of the string, skipping ''.
3567      */
3568     for (p = *arg + 1; *p != NUL; MB_PTR_ADV(p))
3569     {
3570 	if (*p == '\'')
3571 	{
3572 	    if (p[1] != '\'')
3573 		break;
3574 	    ++reduce;
3575 	    ++p;
3576 	}
3577     }
3578 
3579     if (*p != '\'')
3580     {
3581 	semsg(_("E115: Missing quote: %s"), *arg);
3582 	return FAIL;
3583     }
3584 
3585     // If only parsing return after setting "*arg"
3586     if (!evaluate)
3587     {
3588 	*arg = p + 1;
3589 	return OK;
3590     }
3591 
3592     /*
3593      * Copy the string into allocated memory, handling '' to ' reduction.
3594      */
3595     str = alloc((p - *arg) - reduce);
3596     if (str == NULL)
3597 	return FAIL;
3598     rettv->v_type = VAR_STRING;
3599     rettv->vval.v_string = str;
3600 
3601     for (p = *arg + 1; *p != NUL; )
3602     {
3603 	if (*p == '\'')
3604 	{
3605 	    if (p[1] != '\'')
3606 		break;
3607 	    ++p;
3608 	}
3609 	MB_COPY_CHAR(p, str);
3610     }
3611     *str = NUL;
3612     *arg = p + 1;
3613 
3614     return OK;
3615 }
3616 
3617 /*
3618  * Return the function name of the partial.
3619  */
3620     char_u *
3621 partial_name(partial_T *pt)
3622 {
3623     if (pt->pt_name != NULL)
3624 	return pt->pt_name;
3625     return pt->pt_func->uf_name;
3626 }
3627 
3628     static void
3629 partial_free(partial_T *pt)
3630 {
3631     int i;
3632 
3633     for (i = 0; i < pt->pt_argc; ++i)
3634 	clear_tv(&pt->pt_argv[i]);
3635     vim_free(pt->pt_argv);
3636     dict_unref(pt->pt_dict);
3637     if (pt->pt_name != NULL)
3638     {
3639 	func_unref(pt->pt_name);
3640 	vim_free(pt->pt_name);
3641     }
3642     else
3643 	func_ptr_unref(pt->pt_func);
3644     vim_free(pt);
3645 }
3646 
3647 /*
3648  * Unreference a closure: decrement the reference count and free it when it
3649  * becomes zero.
3650  */
3651     void
3652 partial_unref(partial_T *pt)
3653 {
3654     if (pt != NULL && --pt->pt_refcount <= 0)
3655 	partial_free(pt);
3656 }
3657 
3658 static int tv_equal_recurse_limit;
3659 
3660     static int
3661 func_equal(
3662     typval_T *tv1,
3663     typval_T *tv2,
3664     int	     ic)	    // ignore case
3665 {
3666     char_u	*s1, *s2;
3667     dict_T	*d1, *d2;
3668     int		a1, a2;
3669     int		i;
3670 
3671     // empty and NULL function name considered the same
3672     s1 = tv1->v_type == VAR_FUNC ? tv1->vval.v_string
3673 					   : partial_name(tv1->vval.v_partial);
3674     if (s1 != NULL && *s1 == NUL)
3675 	s1 = NULL;
3676     s2 = tv2->v_type == VAR_FUNC ? tv2->vval.v_string
3677 					   : partial_name(tv2->vval.v_partial);
3678     if (s2 != NULL && *s2 == NUL)
3679 	s2 = NULL;
3680     if (s1 == NULL || s2 == NULL)
3681     {
3682 	if (s1 != s2)
3683 	    return FALSE;
3684     }
3685     else if (STRCMP(s1, s2) != 0)
3686 	return FALSE;
3687 
3688     // empty dict and NULL dict is different
3689     d1 = tv1->v_type == VAR_FUNC ? NULL : tv1->vval.v_partial->pt_dict;
3690     d2 = tv2->v_type == VAR_FUNC ? NULL : tv2->vval.v_partial->pt_dict;
3691     if (d1 == NULL || d2 == NULL)
3692     {
3693 	if (d1 != d2)
3694 	    return FALSE;
3695     }
3696     else if (!dict_equal(d1, d2, ic, TRUE))
3697 	return FALSE;
3698 
3699     // empty list and no list considered the same
3700     a1 = tv1->v_type == VAR_FUNC ? 0 : tv1->vval.v_partial->pt_argc;
3701     a2 = tv2->v_type == VAR_FUNC ? 0 : tv2->vval.v_partial->pt_argc;
3702     if (a1 != a2)
3703 	return FALSE;
3704     for (i = 0; i < a1; ++i)
3705 	if (!tv_equal(tv1->vval.v_partial->pt_argv + i,
3706 		      tv2->vval.v_partial->pt_argv + i, ic, TRUE))
3707 	    return FALSE;
3708 
3709     return TRUE;
3710 }
3711 
3712 /*
3713  * Return TRUE if "tv1" and "tv2" have the same value.
3714  * Compares the items just like "==" would compare them, but strings and
3715  * numbers are different.  Floats and numbers are also different.
3716  */
3717     int
3718 tv_equal(
3719     typval_T *tv1,
3720     typval_T *tv2,
3721     int	     ic,	    // ignore case
3722     int	     recursive)	    // TRUE when used recursively
3723 {
3724     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3725     char_u	*s1, *s2;
3726     static int  recursive_cnt = 0;	    // catch recursive loops
3727     int		r;
3728 
3729     // Catch lists and dicts that have an endless loop by limiting
3730     // recursiveness to a limit.  We guess they are equal then.
3731     // A fixed limit has the problem of still taking an awful long time.
3732     // Reduce the limit every time running into it. That should work fine for
3733     // deeply linked structures that are not recursively linked and catch
3734     // recursiveness quickly.
3735     if (!recursive)
3736 	tv_equal_recurse_limit = 1000;
3737     if (recursive_cnt >= tv_equal_recurse_limit)
3738     {
3739 	--tv_equal_recurse_limit;
3740 	return TRUE;
3741     }
3742 
3743     // For VAR_FUNC and VAR_PARTIAL compare the function name, bound dict and
3744     // arguments.
3745     if ((tv1->v_type == VAR_FUNC
3746 		|| (tv1->v_type == VAR_PARTIAL && tv1->vval.v_partial != NULL))
3747 	    && (tv2->v_type == VAR_FUNC
3748 		|| (tv2->v_type == VAR_PARTIAL && tv2->vval.v_partial != NULL)))
3749     {
3750 	++recursive_cnt;
3751 	r = func_equal(tv1, tv2, ic);
3752 	--recursive_cnt;
3753 	return r;
3754     }
3755 
3756     if (tv1->v_type != tv2->v_type)
3757 	return FALSE;
3758 
3759     switch (tv1->v_type)
3760     {
3761 	case VAR_LIST:
3762 	    ++recursive_cnt;
3763 	    r = list_equal(tv1->vval.v_list, tv2->vval.v_list, ic, TRUE);
3764 	    --recursive_cnt;
3765 	    return r;
3766 
3767 	case VAR_DICT:
3768 	    ++recursive_cnt;
3769 	    r = dict_equal(tv1->vval.v_dict, tv2->vval.v_dict, ic, TRUE);
3770 	    --recursive_cnt;
3771 	    return r;
3772 
3773 	case VAR_BLOB:
3774 	    return blob_equal(tv1->vval.v_blob, tv2->vval.v_blob);
3775 
3776 	case VAR_NUMBER:
3777 	    return tv1->vval.v_number == tv2->vval.v_number;
3778 
3779 	case VAR_STRING:
3780 	    s1 = tv_get_string_buf(tv1, buf1);
3781 	    s2 = tv_get_string_buf(tv2, buf2);
3782 	    return ((ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2)) == 0);
3783 
3784 	case VAR_SPECIAL:
3785 	    return tv1->vval.v_number == tv2->vval.v_number;
3786 
3787 	case VAR_FLOAT:
3788 #ifdef FEAT_FLOAT
3789 	    return tv1->vval.v_float == tv2->vval.v_float;
3790 #endif
3791 	case VAR_JOB:
3792 #ifdef FEAT_JOB_CHANNEL
3793 	    return tv1->vval.v_job == tv2->vval.v_job;
3794 #endif
3795 	case VAR_CHANNEL:
3796 #ifdef FEAT_JOB_CHANNEL
3797 	    return tv1->vval.v_channel == tv2->vval.v_channel;
3798 #endif
3799 	case VAR_FUNC:
3800 	case VAR_PARTIAL:
3801 	case VAR_UNKNOWN:
3802 	    break;
3803     }
3804 
3805     // VAR_UNKNOWN can be the result of a invalid expression, let's say it
3806     // does not equal anything, not even itself.
3807     return FALSE;
3808 }
3809 
3810 /*
3811  * Return the next (unique) copy ID.
3812  * Used for serializing nested structures.
3813  */
3814     int
3815 get_copyID(void)
3816 {
3817     current_copyID += COPYID_INC;
3818     return current_copyID;
3819 }
3820 
3821 /*
3822  * Garbage collection for lists and dictionaries.
3823  *
3824  * We use reference counts to be able to free most items right away when they
3825  * are no longer used.  But for composite items it's possible that it becomes
3826  * unused while the reference count is > 0: When there is a recursive
3827  * reference.  Example:
3828  *	:let l = [1, 2, 3]
3829  *	:let d = {9: l}
3830  *	:let l[1] = d
3831  *
3832  * Since this is quite unusual we handle this with garbage collection: every
3833  * once in a while find out which lists and dicts are not referenced from any
3834  * variable.
3835  *
3836  * Here is a good reference text about garbage collection (refers to Python
3837  * but it applies to all reference-counting mechanisms):
3838  *	http://python.ca/nas/python/gc/
3839  */
3840 
3841 /*
3842  * Do garbage collection for lists and dicts.
3843  * When "testing" is TRUE this is called from test_garbagecollect_now().
3844  * Return TRUE if some memory was freed.
3845  */
3846     int
3847 garbage_collect(int testing)
3848 {
3849     int		copyID;
3850     int		abort = FALSE;
3851     buf_T	*buf;
3852     win_T	*wp;
3853     int		did_free = FALSE;
3854     tabpage_T	*tp;
3855 
3856     if (!testing)
3857     {
3858 	// Only do this once.
3859 	want_garbage_collect = FALSE;
3860 	may_garbage_collect = FALSE;
3861 	garbage_collect_at_exit = FALSE;
3862     }
3863 
3864     // We advance by two because we add one for items referenced through
3865     // previous_funccal.
3866     copyID = get_copyID();
3867 
3868     /*
3869      * 1. Go through all accessible variables and mark all lists and dicts
3870      *    with copyID.
3871      */
3872 
3873     // Don't free variables in the previous_funccal list unless they are only
3874     // referenced through previous_funccal.  This must be first, because if
3875     // the item is referenced elsewhere the funccal must not be freed.
3876     abort = abort || set_ref_in_previous_funccal(copyID);
3877 
3878     // script-local variables
3879     abort = abort || garbage_collect_scriptvars(copyID);
3880 
3881     // buffer-local variables
3882     FOR_ALL_BUFFERS(buf)
3883 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
3884 								  NULL, NULL);
3885 
3886     // window-local variables
3887     FOR_ALL_TAB_WINDOWS(tp, wp)
3888 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3889 								  NULL, NULL);
3890     if (aucmd_win != NULL)
3891 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
3892 								  NULL, NULL);
3893 #ifdef FEAT_PROP_POPUP
3894     for (wp = first_popupwin; wp != NULL; wp = wp->w_next)
3895 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3896 								  NULL, NULL);
3897     FOR_ALL_TABPAGES(tp)
3898 	for (wp = tp->tp_first_popupwin; wp != NULL; wp = wp->w_next)
3899 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3900 								  NULL, NULL);
3901 #endif
3902 
3903     // tabpage-local variables
3904     FOR_ALL_TABPAGES(tp)
3905 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
3906 								  NULL, NULL);
3907     // global variables
3908     abort = abort || garbage_collect_globvars(copyID);
3909 
3910     // function-local variables
3911     abort = abort || set_ref_in_call_stack(copyID);
3912 
3913     // named functions (matters for closures)
3914     abort = abort || set_ref_in_functions(copyID);
3915 
3916     // function call arguments, if v:testing is set.
3917     abort = abort || set_ref_in_func_args(copyID);
3918 
3919     // v: vars
3920     abort = abort || garbage_collect_vimvars(copyID);
3921 
3922     // callbacks in buffers
3923     abort = abort || set_ref_in_buffers(copyID);
3924 
3925 #ifdef FEAT_LUA
3926     abort = abort || set_ref_in_lua(copyID);
3927 #endif
3928 
3929 #ifdef FEAT_PYTHON
3930     abort = abort || set_ref_in_python(copyID);
3931 #endif
3932 
3933 #ifdef FEAT_PYTHON3
3934     abort = abort || set_ref_in_python3(copyID);
3935 #endif
3936 
3937 #ifdef FEAT_JOB_CHANNEL
3938     abort = abort || set_ref_in_channel(copyID);
3939     abort = abort || set_ref_in_job(copyID);
3940 #endif
3941 #ifdef FEAT_NETBEANS_INTG
3942     abort = abort || set_ref_in_nb_channel(copyID);
3943 #endif
3944 
3945 #ifdef FEAT_TIMERS
3946     abort = abort || set_ref_in_timer(copyID);
3947 #endif
3948 
3949 #ifdef FEAT_QUICKFIX
3950     abort = abort || set_ref_in_quickfix(copyID);
3951 #endif
3952 
3953 #ifdef FEAT_TERMINAL
3954     abort = abort || set_ref_in_term(copyID);
3955 #endif
3956 
3957 #ifdef FEAT_PROP_POPUP
3958     abort = abort || set_ref_in_popups(copyID);
3959 #endif
3960 
3961     if (!abort)
3962     {
3963 	/*
3964 	 * 2. Free lists and dictionaries that are not referenced.
3965 	 */
3966 	did_free = free_unref_items(copyID);
3967 
3968 	/*
3969 	 * 3. Check if any funccal can be freed now.
3970 	 *    This may call us back recursively.
3971 	 */
3972 	free_unref_funccal(copyID, testing);
3973     }
3974     else if (p_verbose > 0)
3975     {
3976 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
3977     }
3978 
3979     return did_free;
3980 }
3981 
3982 /*
3983  * Free lists, dictionaries, channels and jobs that are no longer referenced.
3984  */
3985     static int
3986 free_unref_items(int copyID)
3987 {
3988     int		did_free = FALSE;
3989 
3990     // Let all "free" functions know that we are here.  This means no
3991     // dictionaries, lists, channels or jobs are to be freed, because we will
3992     // do that here.
3993     in_free_unref_items = TRUE;
3994 
3995     /*
3996      * PASS 1: free the contents of the items.  We don't free the items
3997      * themselves yet, so that it is possible to decrement refcount counters
3998      */
3999 
4000     // Go through the list of dicts and free items without the copyID.
4001     did_free |= dict_free_nonref(copyID);
4002 
4003     // Go through the list of lists and free items without the copyID.
4004     did_free |= list_free_nonref(copyID);
4005 
4006 #ifdef FEAT_JOB_CHANNEL
4007     // Go through the list of jobs and free items without the copyID. This
4008     // must happen before doing channels, because jobs refer to channels, but
4009     // the reference from the channel to the job isn't tracked.
4010     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4011 
4012     // Go through the list of channels and free items without the copyID.
4013     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4014 #endif
4015 
4016     /*
4017      * PASS 2: free the items themselves.
4018      */
4019     dict_free_items(copyID);
4020     list_free_items(copyID);
4021 
4022 #ifdef FEAT_JOB_CHANNEL
4023     // Go through the list of jobs and free items without the copyID. This
4024     // must happen before doing channels, because jobs refer to channels, but
4025     // the reference from the channel to the job isn't tracked.
4026     free_unused_jobs(copyID, COPYID_MASK);
4027 
4028     // Go through the list of channels and free items without the copyID.
4029     free_unused_channels(copyID, COPYID_MASK);
4030 #endif
4031 
4032     in_free_unref_items = FALSE;
4033 
4034     return did_free;
4035 }
4036 
4037 /*
4038  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4039  * "list_stack" is used to add lists to be marked.  Can be NULL.
4040  *
4041  * Returns TRUE if setting references failed somehow.
4042  */
4043     int
4044 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4045 {
4046     int		todo;
4047     int		abort = FALSE;
4048     hashitem_T	*hi;
4049     hashtab_T	*cur_ht;
4050     ht_stack_T	*ht_stack = NULL;
4051     ht_stack_T	*tempitem;
4052 
4053     cur_ht = ht;
4054     for (;;)
4055     {
4056 	if (!abort)
4057 	{
4058 	    // Mark each item in the hashtab.  If the item contains a hashtab
4059 	    // it is added to ht_stack, if it contains a list it is added to
4060 	    // list_stack.
4061 	    todo = (int)cur_ht->ht_used;
4062 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4063 		if (!HASHITEM_EMPTY(hi))
4064 		{
4065 		    --todo;
4066 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4067 						       &ht_stack, list_stack);
4068 		}
4069 	}
4070 
4071 	if (ht_stack == NULL)
4072 	    break;
4073 
4074 	// take an item from the stack
4075 	cur_ht = ht_stack->ht;
4076 	tempitem = ht_stack;
4077 	ht_stack = ht_stack->prev;
4078 	free(tempitem);
4079     }
4080 
4081     return abort;
4082 }
4083 
4084 /*
4085  * Mark a dict and its items with "copyID".
4086  * Returns TRUE if setting references failed somehow.
4087  */
4088     int
4089 set_ref_in_dict(dict_T *d, int copyID)
4090 {
4091     if (d != NULL && d->dv_copyID != copyID)
4092     {
4093 	d->dv_copyID = copyID;
4094 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4095     }
4096     return FALSE;
4097 }
4098 
4099 /*
4100  * Mark a list and its items with "copyID".
4101  * Returns TRUE if setting references failed somehow.
4102  */
4103     int
4104 set_ref_in_list(list_T *ll, int copyID)
4105 {
4106     if (ll != NULL && ll->lv_copyID != copyID)
4107     {
4108 	ll->lv_copyID = copyID;
4109 	return set_ref_in_list_items(ll, copyID, NULL);
4110     }
4111     return FALSE;
4112 }
4113 
4114 /*
4115  * Mark all lists and dicts referenced through list "l" with "copyID".
4116  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4117  *
4118  * Returns TRUE if setting references failed somehow.
4119  */
4120     int
4121 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4122 {
4123     listitem_T	 *li;
4124     int		 abort = FALSE;
4125     list_T	 *cur_l;
4126     list_stack_T *list_stack = NULL;
4127     list_stack_T *tempitem;
4128 
4129     cur_l = l;
4130     for (;;)
4131     {
4132 	if (!abort)
4133 	    // Mark each item in the list.  If the item contains a hashtab
4134 	    // it is added to ht_stack, if it contains a list it is added to
4135 	    // list_stack.
4136 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4137 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4138 						       ht_stack, &list_stack);
4139 	if (list_stack == NULL)
4140 	    break;
4141 
4142 	// take an item from the stack
4143 	cur_l = list_stack->list;
4144 	tempitem = list_stack;
4145 	list_stack = list_stack->prev;
4146 	free(tempitem);
4147     }
4148 
4149     return abort;
4150 }
4151 
4152 /*
4153  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4154  * "list_stack" is used to add lists to be marked.  Can be NULL.
4155  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4156  *
4157  * Returns TRUE if setting references failed somehow.
4158  */
4159     int
4160 set_ref_in_item(
4161     typval_T	    *tv,
4162     int		    copyID,
4163     ht_stack_T	    **ht_stack,
4164     list_stack_T    **list_stack)
4165 {
4166     int		abort = FALSE;
4167 
4168     if (tv->v_type == VAR_DICT)
4169     {
4170 	dict_T	*dd = tv->vval.v_dict;
4171 
4172 	if (dd != NULL && dd->dv_copyID != copyID)
4173 	{
4174 	    // Didn't see this dict yet.
4175 	    dd->dv_copyID = copyID;
4176 	    if (ht_stack == NULL)
4177 	    {
4178 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4179 	    }
4180 	    else
4181 	    {
4182 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
4183 		if (newitem == NULL)
4184 		    abort = TRUE;
4185 		else
4186 		{
4187 		    newitem->ht = &dd->dv_hashtab;
4188 		    newitem->prev = *ht_stack;
4189 		    *ht_stack = newitem;
4190 		}
4191 	    }
4192 	}
4193     }
4194     else if (tv->v_type == VAR_LIST)
4195     {
4196 	list_T	*ll = tv->vval.v_list;
4197 
4198 	if (ll != NULL && ll->lv_copyID != copyID)
4199 	{
4200 	    // Didn't see this list yet.
4201 	    ll->lv_copyID = copyID;
4202 	    if (list_stack == NULL)
4203 	    {
4204 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4205 	    }
4206 	    else
4207 	    {
4208 		list_stack_T *newitem = (list_stack_T*)malloc(
4209 							sizeof(list_stack_T));
4210 		if (newitem == NULL)
4211 		    abort = TRUE;
4212 		else
4213 		{
4214 		    newitem->list = ll;
4215 		    newitem->prev = *list_stack;
4216 		    *list_stack = newitem;
4217 		}
4218 	    }
4219 	}
4220     }
4221     else if (tv->v_type == VAR_FUNC)
4222     {
4223 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4224     }
4225     else if (tv->v_type == VAR_PARTIAL)
4226     {
4227 	partial_T	*pt = tv->vval.v_partial;
4228 	int		i;
4229 
4230 	// A partial does not have a copyID, because it cannot contain itself.
4231 	if (pt != NULL)
4232 	{
4233 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4234 
4235 	    if (pt->pt_dict != NULL)
4236 	    {
4237 		typval_T dtv;
4238 
4239 		dtv.v_type = VAR_DICT;
4240 		dtv.vval.v_dict = pt->pt_dict;
4241 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4242 	    }
4243 
4244 	    for (i = 0; i < pt->pt_argc; ++i)
4245 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4246 							ht_stack, list_stack);
4247 	}
4248     }
4249 #ifdef FEAT_JOB_CHANNEL
4250     else if (tv->v_type == VAR_JOB)
4251     {
4252 	job_T	    *job = tv->vval.v_job;
4253 	typval_T    dtv;
4254 
4255 	if (job != NULL && job->jv_copyID != copyID)
4256 	{
4257 	    job->jv_copyID = copyID;
4258 	    if (job->jv_channel != NULL)
4259 	    {
4260 		dtv.v_type = VAR_CHANNEL;
4261 		dtv.vval.v_channel = job->jv_channel;
4262 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4263 	    }
4264 	    if (job->jv_exit_cb.cb_partial != NULL)
4265 	    {
4266 		dtv.v_type = VAR_PARTIAL;
4267 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4268 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4269 	    }
4270 	}
4271     }
4272     else if (tv->v_type == VAR_CHANNEL)
4273     {
4274 	channel_T   *ch =tv->vval.v_channel;
4275 	ch_part_T   part;
4276 	typval_T    dtv;
4277 	jsonq_T	    *jq;
4278 	cbq_T	    *cq;
4279 
4280 	if (ch != NULL && ch->ch_copyID != copyID)
4281 	{
4282 	    ch->ch_copyID = copyID;
4283 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4284 	    {
4285 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4286 							     jq = jq->jq_next)
4287 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4288 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4289 							     cq = cq->cq_next)
4290 		    if (cq->cq_callback.cb_partial != NULL)
4291 		    {
4292 			dtv.v_type = VAR_PARTIAL;
4293 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4294 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4295 		    }
4296 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4297 		{
4298 		    dtv.v_type = VAR_PARTIAL;
4299 		    dtv.vval.v_partial =
4300 				      ch->ch_part[part].ch_callback.cb_partial;
4301 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4302 		}
4303 	    }
4304 	    if (ch->ch_callback.cb_partial != NULL)
4305 	    {
4306 		dtv.v_type = VAR_PARTIAL;
4307 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4308 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4309 	    }
4310 	    if (ch->ch_close_cb.cb_partial != NULL)
4311 	    {
4312 		dtv.v_type = VAR_PARTIAL;
4313 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4314 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4315 	    }
4316 	}
4317     }
4318 #endif
4319     return abort;
4320 }
4321 
4322 /*
4323  * Return a string with the string representation of a variable.
4324  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4325  * "numbuf" is used for a number.
4326  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4327  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4328  * stings as "string()", otherwise does not put quotes around strings, as
4329  * ":echo" displays values.
4330  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4331  * are replaced with "...".
4332  * May return NULL.
4333  */
4334     char_u *
4335 echo_string_core(
4336     typval_T	*tv,
4337     char_u	**tofree,
4338     char_u	*numbuf,
4339     int		copyID,
4340     int		echo_style,
4341     int		restore_copyID,
4342     int		composite_val)
4343 {
4344     static int	recurse = 0;
4345     char_u	*r = NULL;
4346 
4347     if (recurse >= DICT_MAXNEST)
4348     {
4349 	if (!did_echo_string_emsg)
4350 	{
4351 	    // Only give this message once for a recursive call to avoid
4352 	    // flooding the user with errors.  And stop iterating over lists
4353 	    // and dicts.
4354 	    did_echo_string_emsg = TRUE;
4355 	    emsg(_("E724: variable nested too deep for displaying"));
4356 	}
4357 	*tofree = NULL;
4358 	return (char_u *)"{E724}";
4359     }
4360     ++recurse;
4361 
4362     switch (tv->v_type)
4363     {
4364 	case VAR_STRING:
4365 	    if (echo_style && !composite_val)
4366 	    {
4367 		*tofree = NULL;
4368 		r = tv->vval.v_string;
4369 		if (r == NULL)
4370 		    r = (char_u *)"";
4371 	    }
4372 	    else
4373 	    {
4374 		*tofree = string_quote(tv->vval.v_string, FALSE);
4375 		r = *tofree;
4376 	    }
4377 	    break;
4378 
4379 	case VAR_FUNC:
4380 	    if (echo_style)
4381 	    {
4382 		*tofree = NULL;
4383 		r = tv->vval.v_string;
4384 	    }
4385 	    else
4386 	    {
4387 		*tofree = string_quote(tv->vval.v_string, TRUE);
4388 		r = *tofree;
4389 	    }
4390 	    break;
4391 
4392 	case VAR_PARTIAL:
4393 	    {
4394 		partial_T   *pt = tv->vval.v_partial;
4395 		char_u	    *fname = string_quote(pt == NULL ? NULL
4396 						    : partial_name(pt), FALSE);
4397 		garray_T    ga;
4398 		int	    i;
4399 		char_u	    *tf;
4400 
4401 		ga_init2(&ga, 1, 100);
4402 		ga_concat(&ga, (char_u *)"function(");
4403 		if (fname != NULL)
4404 		{
4405 		    ga_concat(&ga, fname);
4406 		    vim_free(fname);
4407 		}
4408 		if (pt != NULL && pt->pt_argc > 0)
4409 		{
4410 		    ga_concat(&ga, (char_u *)", [");
4411 		    for (i = 0; i < pt->pt_argc; ++i)
4412 		    {
4413 			if (i > 0)
4414 			    ga_concat(&ga, (char_u *)", ");
4415 			ga_concat(&ga,
4416 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
4417 			vim_free(tf);
4418 		    }
4419 		    ga_concat(&ga, (char_u *)"]");
4420 		}
4421 		if (pt != NULL && pt->pt_dict != NULL)
4422 		{
4423 		    typval_T dtv;
4424 
4425 		    ga_concat(&ga, (char_u *)", ");
4426 		    dtv.v_type = VAR_DICT;
4427 		    dtv.vval.v_dict = pt->pt_dict;
4428 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
4429 		    vim_free(tf);
4430 		}
4431 		ga_concat(&ga, (char_u *)")");
4432 
4433 		*tofree = ga.ga_data;
4434 		r = *tofree;
4435 		break;
4436 	    }
4437 
4438 	case VAR_BLOB:
4439 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
4440 	    break;
4441 
4442 	case VAR_LIST:
4443 	    if (tv->vval.v_list == NULL)
4444 	    {
4445 		*tofree = NULL;
4446 		r = NULL;
4447 	    }
4448 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
4449 		    && tv->vval.v_list->lv_len > 0)
4450 	    {
4451 		*tofree = NULL;
4452 		r = (char_u *)"[...]";
4453 	    }
4454 	    else
4455 	    {
4456 		int old_copyID = tv->vval.v_list->lv_copyID;
4457 
4458 		tv->vval.v_list->lv_copyID = copyID;
4459 		*tofree = list2string(tv, copyID, restore_copyID);
4460 		if (restore_copyID)
4461 		    tv->vval.v_list->lv_copyID = old_copyID;
4462 		r = *tofree;
4463 	    }
4464 	    break;
4465 
4466 	case VAR_DICT:
4467 	    if (tv->vval.v_dict == NULL)
4468 	    {
4469 		*tofree = NULL;
4470 		r = NULL;
4471 	    }
4472 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
4473 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
4474 	    {
4475 		*tofree = NULL;
4476 		r = (char_u *)"{...}";
4477 	    }
4478 	    else
4479 	    {
4480 		int old_copyID = tv->vval.v_dict->dv_copyID;
4481 		tv->vval.v_dict->dv_copyID = copyID;
4482 		*tofree = dict2string(tv, copyID, restore_copyID);
4483 		if (restore_copyID)
4484 		    tv->vval.v_dict->dv_copyID = old_copyID;
4485 		r = *tofree;
4486 	    }
4487 	    break;
4488 
4489 	case VAR_NUMBER:
4490 	case VAR_UNKNOWN:
4491 	    *tofree = NULL;
4492 	    r = tv_get_string_buf(tv, numbuf);
4493 	    break;
4494 
4495 	case VAR_JOB:
4496 	case VAR_CHANNEL:
4497 	    *tofree = NULL;
4498 	    r = tv_get_string_buf(tv, numbuf);
4499 	    if (composite_val)
4500 	    {
4501 		*tofree = string_quote(r, FALSE);
4502 		r = *tofree;
4503 	    }
4504 	    break;
4505 
4506 	case VAR_FLOAT:
4507 #ifdef FEAT_FLOAT
4508 	    *tofree = NULL;
4509 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
4510 	    r = numbuf;
4511 	    break;
4512 #endif
4513 
4514 	case VAR_SPECIAL:
4515 	    *tofree = NULL;
4516 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
4517 	    break;
4518     }
4519 
4520     if (--recurse == 0)
4521 	did_echo_string_emsg = FALSE;
4522     return r;
4523 }
4524 
4525 /*
4526  * Return a string with the string representation of a variable.
4527  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4528  * "numbuf" is used for a number.
4529  * Does not put quotes around strings, as ":echo" displays values.
4530  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4531  * May return NULL.
4532  */
4533     char_u *
4534 echo_string(
4535     typval_T	*tv,
4536     char_u	**tofree,
4537     char_u	*numbuf,
4538     int		copyID)
4539 {
4540     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
4541 }
4542 
4543 /*
4544  * Return a string with the string representation of a variable.
4545  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4546  * "numbuf" is used for a number.
4547  * Puts quotes around strings, so that they can be parsed back by eval().
4548  * May return NULL.
4549  */
4550     char_u *
4551 tv2string(
4552     typval_T	*tv,
4553     char_u	**tofree,
4554     char_u	*numbuf,
4555     int		copyID)
4556 {
4557     return echo_string_core(tv, tofree, numbuf, copyID, FALSE, TRUE, FALSE);
4558 }
4559 
4560 /*
4561  * Return string "str" in ' quotes, doubling ' characters.
4562  * If "str" is NULL an empty string is assumed.
4563  * If "function" is TRUE make it function('string').
4564  */
4565     char_u *
4566 string_quote(char_u *str, int function)
4567 {
4568     unsigned	len;
4569     char_u	*p, *r, *s;
4570 
4571     len = (function ? 13 : 3);
4572     if (str != NULL)
4573     {
4574 	len += (unsigned)STRLEN(str);
4575 	for (p = str; *p != NUL; MB_PTR_ADV(p))
4576 	    if (*p == '\'')
4577 		++len;
4578     }
4579     s = r = alloc(len);
4580     if (r != NULL)
4581     {
4582 	if (function)
4583 	{
4584 	    STRCPY(r, "function('");
4585 	    r += 10;
4586 	}
4587 	else
4588 	    *r++ = '\'';
4589 	if (str != NULL)
4590 	    for (p = str; *p != NUL; )
4591 	    {
4592 		if (*p == '\'')
4593 		    *r++ = '\'';
4594 		MB_COPY_CHAR(p, r);
4595 	    }
4596 	*r++ = '\'';
4597 	if (function)
4598 	    *r++ = ')';
4599 	*r++ = NUL;
4600     }
4601     return s;
4602 }
4603 
4604 #if defined(FEAT_FLOAT) || defined(PROTO)
4605 /*
4606  * Convert the string "text" to a floating point number.
4607  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
4608  * this always uses a decimal point.
4609  * Returns the length of the text that was consumed.
4610  */
4611     int
4612 string2float(
4613     char_u	*text,
4614     float_T	*value)	    // result stored here
4615 {
4616     char	*s = (char *)text;
4617     float_T	f;
4618 
4619     // MS-Windows does not deal with "inf" and "nan" properly.
4620     if (STRNICMP(text, "inf", 3) == 0)
4621     {
4622 	*value = INFINITY;
4623 	return 3;
4624     }
4625     if (STRNICMP(text, "-inf", 3) == 0)
4626     {
4627 	*value = -INFINITY;
4628 	return 4;
4629     }
4630     if (STRNICMP(text, "nan", 3) == 0)
4631     {
4632 	*value = NAN;
4633 	return 3;
4634     }
4635     f = strtod(s, &s);
4636     *value = f;
4637     return (int)((char_u *)s - text);
4638 }
4639 #endif
4640 
4641 /*
4642  * Get the value of an environment variable.
4643  * "arg" is pointing to the '$'.  It is advanced to after the name.
4644  * If the environment variable was not set, silently assume it is empty.
4645  * Return FAIL if the name is invalid.
4646  */
4647     static int
4648 get_env_tv(char_u **arg, typval_T *rettv, int evaluate)
4649 {
4650     char_u	*string = NULL;
4651     int		len;
4652     int		cc;
4653     char_u	*name;
4654     int		mustfree = FALSE;
4655 
4656     ++*arg;
4657     name = *arg;
4658     len = get_env_len(arg);
4659     if (evaluate)
4660     {
4661 	if (len == 0)
4662 	    return FAIL; // invalid empty name
4663 
4664 	cc = name[len];
4665 	name[len] = NUL;
4666 	// first try vim_getenv(), fast for normal environment vars
4667 	string = vim_getenv(name, &mustfree);
4668 	if (string != NULL && *string != NUL)
4669 	{
4670 	    if (!mustfree)
4671 		string = vim_strsave(string);
4672 	}
4673 	else
4674 	{
4675 	    if (mustfree)
4676 		vim_free(string);
4677 
4678 	    // next try expanding things like $VIM and ${HOME}
4679 	    string = expand_env_save(name - 1);
4680 	    if (string != NULL && *string == '$')
4681 		VIM_CLEAR(string);
4682 	}
4683 	name[len] = cc;
4684 
4685 	rettv->v_type = VAR_STRING;
4686 	rettv->vval.v_string = string;
4687     }
4688 
4689     return OK;
4690 }
4691 
4692 /*
4693  * Translate a String variable into a position.
4694  * Returns NULL when there is an error.
4695  */
4696     pos_T *
4697 var2fpos(
4698     typval_T	*varp,
4699     int		dollar_lnum,	// TRUE when $ is last line
4700     int		*fnum)		// set to fnum for '0, 'A, etc.
4701 {
4702     char_u		*name;
4703     static pos_T	pos;
4704     pos_T		*pp;
4705 
4706     // Argument can be [lnum, col, coladd].
4707     if (varp->v_type == VAR_LIST)
4708     {
4709 	list_T		*l;
4710 	int		len;
4711 	int		error = FALSE;
4712 	listitem_T	*li;
4713 
4714 	l = varp->vval.v_list;
4715 	if (l == NULL)
4716 	    return NULL;
4717 
4718 	// Get the line number
4719 	pos.lnum = list_find_nr(l, 0L, &error);
4720 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
4721 	    return NULL;	// invalid line number
4722 
4723 	// Get the column number
4724 	pos.col = list_find_nr(l, 1L, &error);
4725 	if (error)
4726 	    return NULL;
4727 	len = (long)STRLEN(ml_get(pos.lnum));
4728 
4729 	// We accept "$" for the column number: last column.
4730 	li = list_find(l, 1L);
4731 	if (li != NULL && li->li_tv.v_type == VAR_STRING
4732 		&& li->li_tv.vval.v_string != NULL
4733 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
4734 	    pos.col = len + 1;
4735 
4736 	// Accept a position up to the NUL after the line.
4737 	if (pos.col == 0 || (int)pos.col > len + 1)
4738 	    return NULL;	// invalid column number
4739 	--pos.col;
4740 
4741 	// Get the virtual offset.  Defaults to zero.
4742 	pos.coladd = list_find_nr(l, 2L, &error);
4743 	if (error)
4744 	    pos.coladd = 0;
4745 
4746 	return &pos;
4747     }
4748 
4749     name = tv_get_string_chk(varp);
4750     if (name == NULL)
4751 	return NULL;
4752     if (name[0] == '.')				// cursor
4753 	return &curwin->w_cursor;
4754     if (name[0] == 'v' && name[1] == NUL)	// Visual start
4755     {
4756 	if (VIsual_active)
4757 	    return &VIsual;
4758 	return &curwin->w_cursor;
4759     }
4760     if (name[0] == '\'')			// mark
4761     {
4762 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
4763 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
4764 	    return NULL;
4765 	return pp;
4766     }
4767 
4768     pos.coladd = 0;
4769 
4770     if (name[0] == 'w' && dollar_lnum)
4771     {
4772 	pos.col = 0;
4773 	if (name[1] == '0')		// "w0": first visible line
4774 	{
4775 	    update_topline();
4776 	    // In silent Ex mode topline is zero, but that's not a valid line
4777 	    // number; use one instead.
4778 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
4779 	    return &pos;
4780 	}
4781 	else if (name[1] == '$')	// "w$": last visible line
4782 	{
4783 	    validate_botline();
4784 	    // In silent Ex mode botline is zero, return zero then.
4785 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
4786 	    return &pos;
4787 	}
4788     }
4789     else if (name[0] == '$')		// last column or line
4790     {
4791 	if (dollar_lnum)
4792 	{
4793 	    pos.lnum = curbuf->b_ml.ml_line_count;
4794 	    pos.col = 0;
4795 	}
4796 	else
4797 	{
4798 	    pos.lnum = curwin->w_cursor.lnum;
4799 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
4800 	}
4801 	return &pos;
4802     }
4803     return NULL;
4804 }
4805 
4806 /*
4807  * Convert list in "arg" into a position and optional file number.
4808  * When "fnump" is NULL there is no file number, only 3 items.
4809  * Note that the column is passed on as-is, the caller may want to decrement
4810  * it to use 1 for the first column.
4811  * Return FAIL when conversion is not possible, doesn't check the position for
4812  * validity.
4813  */
4814     int
4815 list2fpos(
4816     typval_T	*arg,
4817     pos_T	*posp,
4818     int		*fnump,
4819     colnr_T	*curswantp)
4820 {
4821     list_T	*l = arg->vval.v_list;
4822     long	i = 0;
4823     long	n;
4824 
4825     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
4826     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
4827     if (arg->v_type != VAR_LIST
4828 	    || l == NULL
4829 	    || l->lv_len < (fnump == NULL ? 2 : 3)
4830 	    || l->lv_len > (fnump == NULL ? 4 : 5))
4831 	return FAIL;
4832 
4833     if (fnump != NULL)
4834     {
4835 	n = list_find_nr(l, i++, NULL);	// fnum
4836 	if (n < 0)
4837 	    return FAIL;
4838 	if (n == 0)
4839 	    n = curbuf->b_fnum;		// current buffer
4840 	*fnump = n;
4841     }
4842 
4843     n = list_find_nr(l, i++, NULL);	// lnum
4844     if (n < 0)
4845 	return FAIL;
4846     posp->lnum = n;
4847 
4848     n = list_find_nr(l, i++, NULL);	// col
4849     if (n < 0)
4850 	return FAIL;
4851     posp->col = n;
4852 
4853     n = list_find_nr(l, i, NULL);	// off
4854     if (n < 0)
4855 	posp->coladd = 0;
4856     else
4857 	posp->coladd = n;
4858 
4859     if (curswantp != NULL)
4860 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
4861 
4862     return OK;
4863 }
4864 
4865 /*
4866  * Get the length of an environment variable name.
4867  * Advance "arg" to the first character after the name.
4868  * Return 0 for error.
4869  */
4870     int
4871 get_env_len(char_u **arg)
4872 {
4873     char_u	*p;
4874     int		len;
4875 
4876     for (p = *arg; vim_isIDc(*p); ++p)
4877 	;
4878     if (p == *arg)	    // no name found
4879 	return 0;
4880 
4881     len = (int)(p - *arg);
4882     *arg = p;
4883     return len;
4884 }
4885 
4886 /*
4887  * Get the length of the name of a function or internal variable.
4888  * "arg" is advanced to the first non-white character after the name.
4889  * Return 0 if something is wrong.
4890  */
4891     int
4892 get_id_len(char_u **arg)
4893 {
4894     char_u	*p;
4895     int		len;
4896 
4897     // Find the end of the name.
4898     for (p = *arg; eval_isnamec(*p); ++p)
4899     {
4900 	if (*p == ':')
4901 	{
4902 	    // "s:" is start of "s:var", but "n:" is not and can be used in
4903 	    // slice "[n:]".  Also "xx:" is not a namespace.
4904 	    len = (int)(p - *arg);
4905 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
4906 		    || len > 1)
4907 		break;
4908 	}
4909     }
4910     if (p == *arg)	    // no name found
4911 	return 0;
4912 
4913     len = (int)(p - *arg);
4914     *arg = skipwhite(p);
4915 
4916     return len;
4917 }
4918 
4919 /*
4920  * Get the length of the name of a variable or function.
4921  * Only the name is recognized, does not handle ".key" or "[idx]".
4922  * "arg" is advanced to the first non-white character after the name.
4923  * Return -1 if curly braces expansion failed.
4924  * Return 0 if something else is wrong.
4925  * If the name contains 'magic' {}'s, expand them and return the
4926  * expanded name in an allocated string via 'alias' - caller must free.
4927  */
4928     int
4929 get_name_len(
4930     char_u	**arg,
4931     char_u	**alias,
4932     int		evaluate,
4933     int		verbose)
4934 {
4935     int		len;
4936     char_u	*p;
4937     char_u	*expr_start;
4938     char_u	*expr_end;
4939 
4940     *alias = NULL;  // default to no alias
4941 
4942     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
4943 						  && (*arg)[2] == (int)KE_SNR)
4944     {
4945 	// hard coded <SNR>, already translated
4946 	*arg += 3;
4947 	return get_id_len(arg) + 3;
4948     }
4949     len = eval_fname_script(*arg);
4950     if (len > 0)
4951     {
4952 	// literal "<SID>", "s:" or "<SNR>"
4953 	*arg += len;
4954     }
4955 
4956     /*
4957      * Find the end of the name; check for {} construction.
4958      */
4959     p = find_name_end(*arg, &expr_start, &expr_end,
4960 					       len > 0 ? 0 : FNE_CHECK_START);
4961     if (expr_start != NULL)
4962     {
4963 	char_u	*temp_string;
4964 
4965 	if (!evaluate)
4966 	{
4967 	    len += (int)(p - *arg);
4968 	    *arg = skipwhite(p);
4969 	    return len;
4970 	}
4971 
4972 	/*
4973 	 * Include any <SID> etc in the expanded string:
4974 	 * Thus the -len here.
4975 	 */
4976 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
4977 	if (temp_string == NULL)
4978 	    return -1;
4979 	*alias = temp_string;
4980 	*arg = skipwhite(p);
4981 	return (int)STRLEN(temp_string);
4982     }
4983 
4984     len += get_id_len(arg);
4985     // Only give an error when there is something, otherwise it will be
4986     // reported at a higher level.
4987     if (len == 0 && verbose && **arg != NUL)
4988 	semsg(_(e_invexpr2), *arg);
4989 
4990     return len;
4991 }
4992 
4993 /*
4994  * Find the end of a variable or function name, taking care of magic braces.
4995  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
4996  * start and end of the first magic braces item.
4997  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
4998  * Return a pointer to just after the name.  Equal to "arg" if there is no
4999  * valid name.
5000  */
5001     char_u *
5002 find_name_end(
5003     char_u	*arg,
5004     char_u	**expr_start,
5005     char_u	**expr_end,
5006     int		flags)
5007 {
5008     int		mb_nest = 0;
5009     int		br_nest = 0;
5010     char_u	*p;
5011     int		len;
5012 
5013     if (expr_start != NULL)
5014     {
5015 	*expr_start = NULL;
5016 	*expr_end = NULL;
5017     }
5018 
5019     // Quick check for valid starting character.
5020     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg) && *arg != '{')
5021 	return arg;
5022 
5023     for (p = arg; *p != NUL
5024 		    && (eval_isnamec(*p)
5025 			|| *p == '{'
5026 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
5027 			|| mb_nest != 0
5028 			|| br_nest != 0); MB_PTR_ADV(p))
5029     {
5030 	if (*p == '\'')
5031 	{
5032 	    // skip over 'string' to avoid counting [ and ] inside it.
5033 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5034 		;
5035 	    if (*p == NUL)
5036 		break;
5037 	}
5038 	else if (*p == '"')
5039 	{
5040 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
5041 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5042 		if (*p == '\\' && p[1] != NUL)
5043 		    ++p;
5044 	    if (*p == NUL)
5045 		break;
5046 	}
5047 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5048 	{
5049 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5050 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
5051 	    len = (int)(p - arg);
5052 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5053 		    || (len > 1 && p[-1] != '}'))
5054 		break;
5055 	}
5056 
5057 	if (mb_nest == 0)
5058 	{
5059 	    if (*p == '[')
5060 		++br_nest;
5061 	    else if (*p == ']')
5062 		--br_nest;
5063 	}
5064 
5065 	if (br_nest == 0)
5066 	{
5067 	    if (*p == '{')
5068 	    {
5069 		mb_nest++;
5070 		if (expr_start != NULL && *expr_start == NULL)
5071 		    *expr_start = p;
5072 	    }
5073 	    else if (*p == '}')
5074 	    {
5075 		mb_nest--;
5076 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5077 		    *expr_end = p;
5078 	    }
5079 	}
5080     }
5081 
5082     return p;
5083 }
5084 
5085 /*
5086  * Expands out the 'magic' {}'s in a variable/function name.
5087  * Note that this can call itself recursively, to deal with
5088  * constructs like foo{bar}{baz}{bam}
5089  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5090  *			"in_start"      ^
5091  *			"expr_start"	   ^
5092  *			"expr_end"		 ^
5093  *			"in_end"			    ^
5094  *
5095  * Returns a new allocated string, which the caller must free.
5096  * Returns NULL for failure.
5097  */
5098     static char_u *
5099 make_expanded_name(
5100     char_u	*in_start,
5101     char_u	*expr_start,
5102     char_u	*expr_end,
5103     char_u	*in_end)
5104 {
5105     char_u	c1;
5106     char_u	*retval = NULL;
5107     char_u	*temp_result;
5108     char_u	*nextcmd = NULL;
5109 
5110     if (expr_end == NULL || in_end == NULL)
5111 	return NULL;
5112     *expr_start	= NUL;
5113     *expr_end = NUL;
5114     c1 = *in_end;
5115     *in_end = NUL;
5116 
5117     temp_result = eval_to_string(expr_start + 1, &nextcmd, FALSE);
5118     if (temp_result != NULL && nextcmd == NULL)
5119     {
5120 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5121 						   + (in_end - expr_end) + 1);
5122 	if (retval != NULL)
5123 	{
5124 	    STRCPY(retval, in_start);
5125 	    STRCAT(retval, temp_result);
5126 	    STRCAT(retval, expr_end + 1);
5127 	}
5128     }
5129     vim_free(temp_result);
5130 
5131     *in_end = c1;		// put char back for error messages
5132     *expr_start = '{';
5133     *expr_end = '}';
5134 
5135     if (retval != NULL)
5136     {
5137 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5138 	if (expr_start != NULL)
5139 	{
5140 	    // Further expansion!
5141 	    temp_result = make_expanded_name(retval, expr_start,
5142 						       expr_end, temp_result);
5143 	    vim_free(retval);
5144 	    retval = temp_result;
5145 	}
5146     }
5147 
5148     return retval;
5149 }
5150 
5151 /*
5152  * Return TRUE if character "c" can be used in a variable or function name.
5153  * Does not include '{' or '}' for magic braces.
5154  */
5155     int
5156 eval_isnamec(int c)
5157 {
5158     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
5159 }
5160 
5161 /*
5162  * Return TRUE if character "c" can be used as the first character in a
5163  * variable or function name (excluding '{' and '}').
5164  */
5165     int
5166 eval_isnamec1(int c)
5167 {
5168     return (ASCII_ISALPHA(c) || c == '_');
5169 }
5170 
5171 /*
5172  * Handle:
5173  * - expr[expr], expr[expr:expr] subscript
5174  * - ".name" lookup
5175  * - function call with Funcref variable: func(expr)
5176  * - method call: var->method()
5177  *
5178  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5179  */
5180     int
5181 handle_subscript(
5182     char_u	**arg,
5183     typval_T	*rettv,
5184     int		evaluate,	// do more than finding the end
5185     int		verbose,	// give error messages
5186     char_u	*start_leader,	// start of '!' and '-' prefixes
5187     char_u	**end_leaderp)  // end of '!' and '-' prefixes
5188 {
5189     int		ret = OK;
5190     dict_T	*selfdict = NULL;
5191 
5192     // "." is ".name" lookup when we found a dict or when evaluating and
5193     // scriptversion is at least 2, where string concatenation is "..".
5194     while (ret == OK
5195 	    && (((**arg == '['
5196 		    || (**arg == '.' && (rettv->v_type == VAR_DICT
5197 			|| (!evaluate
5198 			    && (*arg)[1] != '.'
5199 			    && current_sctx.sc_version >= 2)))
5200 		    || (**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5201 					    || rettv->v_type == VAR_PARTIAL)))
5202 		&& !VIM_ISWHITE(*(*arg - 1)))
5203 	    || (**arg == '-' && (*arg)[1] == '>')))
5204     {
5205 	if (**arg == '(')
5206 	{
5207 	    ret = call_func_rettv(arg, rettv, evaluate, selfdict, NULL);
5208 
5209 	    // Stop the expression evaluation when immediately aborting on
5210 	    // error, or when an interrupt occurred or an exception was thrown
5211 	    // but not caught.
5212 	    if (aborting())
5213 	    {
5214 		if (ret == OK)
5215 		    clear_tv(rettv);
5216 		ret = FAIL;
5217 	    }
5218 	    dict_unref(selfdict);
5219 	    selfdict = NULL;
5220 	}
5221 	else if (**arg == '-')
5222 	{
5223 	    // Expression "-1.0->method()" applies the leader "-" before
5224 	    // applying ->.
5225 	    if (evaluate && *end_leaderp > start_leader)
5226 		ret = eval7_leader(rettv, start_leader, end_leaderp);
5227 	    if (ret == OK)
5228 	    {
5229 		if ((*arg)[2] == '{')
5230 		    // expr->{lambda}()
5231 		    ret = eval_lambda(arg, rettv, evaluate, verbose);
5232 		else
5233 		    // expr->name()
5234 		    ret = eval_method(arg, rettv, evaluate, verbose);
5235 	    }
5236 	}
5237 	else // **arg == '[' || **arg == '.'
5238 	{
5239 	    dict_unref(selfdict);
5240 	    if (rettv->v_type == VAR_DICT)
5241 	    {
5242 		selfdict = rettv->vval.v_dict;
5243 		if (selfdict != NULL)
5244 		    ++selfdict->dv_refcount;
5245 	    }
5246 	    else
5247 		selfdict = NULL;
5248 	    if (eval_index(arg, rettv, evaluate, verbose) == FAIL)
5249 	    {
5250 		clear_tv(rettv);
5251 		ret = FAIL;
5252 	    }
5253 	}
5254     }
5255 
5256     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5257     // Don't do this when "Func" is already a partial that was bound
5258     // explicitly (pt_auto is FALSE).
5259     if (selfdict != NULL
5260 	    && (rettv->v_type == VAR_FUNC
5261 		|| (rettv->v_type == VAR_PARTIAL
5262 		    && (rettv->vval.v_partial->pt_auto
5263 			|| rettv->vval.v_partial->pt_dict == NULL))))
5264 	selfdict = make_partial(selfdict, rettv);
5265 
5266     dict_unref(selfdict);
5267     return ret;
5268 }
5269 
5270 /*
5271  * Allocate memory for a variable type-value, and make it empty (0 or NULL
5272  * value).
5273  */
5274     typval_T *
5275 alloc_tv(void)
5276 {
5277     return ALLOC_CLEAR_ONE(typval_T);
5278 }
5279 
5280 /*
5281  * Allocate memory for a variable type-value, and assign a string to it.
5282  * The string "s" must have been allocated, it is consumed.
5283  * Return NULL for out of memory, the variable otherwise.
5284  */
5285     typval_T *
5286 alloc_string_tv(char_u *s)
5287 {
5288     typval_T	*rettv;
5289 
5290     rettv = alloc_tv();
5291     if (rettv != NULL)
5292     {
5293 	rettv->v_type = VAR_STRING;
5294 	rettv->vval.v_string = s;
5295     }
5296     else
5297 	vim_free(s);
5298     return rettv;
5299 }
5300 
5301 /*
5302  * Free the memory for a variable type-value.
5303  */
5304     void
5305 free_tv(typval_T *varp)
5306 {
5307     if (varp != NULL)
5308     {
5309 	switch (varp->v_type)
5310 	{
5311 	    case VAR_FUNC:
5312 		func_unref(varp->vval.v_string);
5313 		// FALLTHROUGH
5314 	    case VAR_STRING:
5315 		vim_free(varp->vval.v_string);
5316 		break;
5317 	    case VAR_PARTIAL:
5318 		partial_unref(varp->vval.v_partial);
5319 		break;
5320 	    case VAR_BLOB:
5321 		blob_unref(varp->vval.v_blob);
5322 		break;
5323 	    case VAR_LIST:
5324 		list_unref(varp->vval.v_list);
5325 		break;
5326 	    case VAR_DICT:
5327 		dict_unref(varp->vval.v_dict);
5328 		break;
5329 	    case VAR_JOB:
5330 #ifdef FEAT_JOB_CHANNEL
5331 		job_unref(varp->vval.v_job);
5332 		break;
5333 #endif
5334 	    case VAR_CHANNEL:
5335 #ifdef FEAT_JOB_CHANNEL
5336 		channel_unref(varp->vval.v_channel);
5337 		break;
5338 #endif
5339 	    case VAR_NUMBER:
5340 	    case VAR_FLOAT:
5341 	    case VAR_UNKNOWN:
5342 	    case VAR_SPECIAL:
5343 		break;
5344 	}
5345 	vim_free(varp);
5346     }
5347 }
5348 
5349 /*
5350  * Free the memory for a variable value and set the value to NULL or 0.
5351  */
5352     void
5353 clear_tv(typval_T *varp)
5354 {
5355     if (varp != NULL)
5356     {
5357 	switch (varp->v_type)
5358 	{
5359 	    case VAR_FUNC:
5360 		func_unref(varp->vval.v_string);
5361 		// FALLTHROUGH
5362 	    case VAR_STRING:
5363 		VIM_CLEAR(varp->vval.v_string);
5364 		break;
5365 	    case VAR_PARTIAL:
5366 		partial_unref(varp->vval.v_partial);
5367 		varp->vval.v_partial = NULL;
5368 		break;
5369 	    case VAR_BLOB:
5370 		blob_unref(varp->vval.v_blob);
5371 		varp->vval.v_blob = NULL;
5372 		break;
5373 	    case VAR_LIST:
5374 		list_unref(varp->vval.v_list);
5375 		varp->vval.v_list = NULL;
5376 		break;
5377 	    case VAR_DICT:
5378 		dict_unref(varp->vval.v_dict);
5379 		varp->vval.v_dict = NULL;
5380 		break;
5381 	    case VAR_NUMBER:
5382 	    case VAR_SPECIAL:
5383 		varp->vval.v_number = 0;
5384 		break;
5385 	    case VAR_FLOAT:
5386 #ifdef FEAT_FLOAT
5387 		varp->vval.v_float = 0.0;
5388 		break;
5389 #endif
5390 	    case VAR_JOB:
5391 #ifdef FEAT_JOB_CHANNEL
5392 		job_unref(varp->vval.v_job);
5393 		varp->vval.v_job = NULL;
5394 #endif
5395 		break;
5396 	    case VAR_CHANNEL:
5397 #ifdef FEAT_JOB_CHANNEL
5398 		channel_unref(varp->vval.v_channel);
5399 		varp->vval.v_channel = NULL;
5400 #endif
5401 	    case VAR_UNKNOWN:
5402 		break;
5403 	}
5404 	varp->v_lock = 0;
5405     }
5406 }
5407 
5408 /*
5409  * Set the value of a variable to NULL without freeing items.
5410  */
5411     void
5412 init_tv(typval_T *varp)
5413 {
5414     if (varp != NULL)
5415 	vim_memset(varp, 0, sizeof(typval_T));
5416 }
5417 
5418 /*
5419  * Get the number value of a variable.
5420  * If it is a String variable, uses vim_str2nr().
5421  * For incompatible types, return 0.
5422  * tv_get_number_chk() is similar to tv_get_number(), but informs the
5423  * caller of incompatible types: it sets *denote to TRUE if "denote"
5424  * is not NULL or returns -1 otherwise.
5425  */
5426     varnumber_T
5427 tv_get_number(typval_T *varp)
5428 {
5429     int		error = FALSE;
5430 
5431     return tv_get_number_chk(varp, &error);	// return 0L on error
5432 }
5433 
5434     varnumber_T
5435 tv_get_number_chk(typval_T *varp, int *denote)
5436 {
5437     varnumber_T	n = 0L;
5438 
5439     switch (varp->v_type)
5440     {
5441 	case VAR_NUMBER:
5442 	    return varp->vval.v_number;
5443 	case VAR_FLOAT:
5444 #ifdef FEAT_FLOAT
5445 	    emsg(_("E805: Using a Float as a Number"));
5446 	    break;
5447 #endif
5448 	case VAR_FUNC:
5449 	case VAR_PARTIAL:
5450 	    emsg(_("E703: Using a Funcref as a Number"));
5451 	    break;
5452 	case VAR_STRING:
5453 	    if (varp->vval.v_string != NULL)
5454 		vim_str2nr(varp->vval.v_string, NULL, NULL,
5455 					    STR2NR_ALL, &n, NULL, 0, FALSE);
5456 	    return n;
5457 	case VAR_LIST:
5458 	    emsg(_("E745: Using a List as a Number"));
5459 	    break;
5460 	case VAR_DICT:
5461 	    emsg(_("E728: Using a Dictionary as a Number"));
5462 	    break;
5463 	case VAR_SPECIAL:
5464 	    return varp->vval.v_number == VVAL_TRUE ? 1 : 0;
5465 	    break;
5466 	case VAR_JOB:
5467 #ifdef FEAT_JOB_CHANNEL
5468 	    emsg(_("E910: Using a Job as a Number"));
5469 	    break;
5470 #endif
5471 	case VAR_CHANNEL:
5472 #ifdef FEAT_JOB_CHANNEL
5473 	    emsg(_("E913: Using a Channel as a Number"));
5474 	    break;
5475 #endif
5476 	case VAR_BLOB:
5477 	    emsg(_("E974: Using a Blob as a Number"));
5478 	    break;
5479 	case VAR_UNKNOWN:
5480 	    internal_error("tv_get_number(UNKNOWN)");
5481 	    break;
5482     }
5483     if (denote == NULL)		// useful for values that must be unsigned
5484 	n = -1;
5485     else
5486 	*denote = TRUE;
5487     return n;
5488 }
5489 
5490 #ifdef FEAT_FLOAT
5491     float_T
5492 tv_get_float(typval_T *varp)
5493 {
5494     switch (varp->v_type)
5495     {
5496 	case VAR_NUMBER:
5497 	    return (float_T)(varp->vval.v_number);
5498 	case VAR_FLOAT:
5499 	    return varp->vval.v_float;
5500 	case VAR_FUNC:
5501 	case VAR_PARTIAL:
5502 	    emsg(_("E891: Using a Funcref as a Float"));
5503 	    break;
5504 	case VAR_STRING:
5505 	    emsg(_("E892: Using a String as a Float"));
5506 	    break;
5507 	case VAR_LIST:
5508 	    emsg(_("E893: Using a List as a Float"));
5509 	    break;
5510 	case VAR_DICT:
5511 	    emsg(_("E894: Using a Dictionary as a Float"));
5512 	    break;
5513 	case VAR_SPECIAL:
5514 	    emsg(_("E907: Using a special value as a Float"));
5515 	    break;
5516 	case VAR_JOB:
5517 # ifdef FEAT_JOB_CHANNEL
5518 	    emsg(_("E911: Using a Job as a Float"));
5519 	    break;
5520 # endif
5521 	case VAR_CHANNEL:
5522 # ifdef FEAT_JOB_CHANNEL
5523 	    emsg(_("E914: Using a Channel as a Float"));
5524 	    break;
5525 # endif
5526 	case VAR_BLOB:
5527 	    emsg(_("E975: Using a Blob as a Float"));
5528 	    break;
5529 	case VAR_UNKNOWN:
5530 	    internal_error("tv_get_float(UNKNOWN)");
5531 	    break;
5532     }
5533     return 0;
5534 }
5535 #endif
5536 
5537 /*
5538  * Get the string value of a variable.
5539  * If it is a Number variable, the number is converted into a string.
5540  * tv_get_string() uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
5541  * tv_get_string_buf() uses a given buffer.
5542  * If the String variable has never been set, return an empty string.
5543  * Never returns NULL;
5544  * tv_get_string_chk() and tv_get_string_buf_chk() are similar, but return
5545  * NULL on error.
5546  */
5547     char_u *
5548 tv_get_string(typval_T *varp)
5549 {
5550     static char_u   mybuf[NUMBUFLEN];
5551 
5552     return tv_get_string_buf(varp, mybuf);
5553 }
5554 
5555     char_u *
5556 tv_get_string_buf(typval_T *varp, char_u *buf)
5557 {
5558     char_u	*res =  tv_get_string_buf_chk(varp, buf);
5559 
5560     return res != NULL ? res : (char_u *)"";
5561 }
5562 
5563 /*
5564  * Careful: This uses a single, static buffer.  YOU CAN ONLY USE IT ONCE!
5565  */
5566     char_u *
5567 tv_get_string_chk(typval_T *varp)
5568 {
5569     static char_u   mybuf[NUMBUFLEN];
5570 
5571     return tv_get_string_buf_chk(varp, mybuf);
5572 }
5573 
5574     char_u *
5575 tv_get_string_buf_chk(typval_T *varp, char_u *buf)
5576 {
5577     switch (varp->v_type)
5578     {
5579 	case VAR_NUMBER:
5580 	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
5581 					    (long_long_T)varp->vval.v_number);
5582 	    return buf;
5583 	case VAR_FUNC:
5584 	case VAR_PARTIAL:
5585 	    emsg(_("E729: using Funcref as a String"));
5586 	    break;
5587 	case VAR_LIST:
5588 	    emsg(_("E730: using List as a String"));
5589 	    break;
5590 	case VAR_DICT:
5591 	    emsg(_("E731: using Dictionary as a String"));
5592 	    break;
5593 	case VAR_FLOAT:
5594 #ifdef FEAT_FLOAT
5595 	    emsg(_(e_float_as_string));
5596 	    break;
5597 #endif
5598 	case VAR_STRING:
5599 	    if (varp->vval.v_string != NULL)
5600 		return varp->vval.v_string;
5601 	    return (char_u *)"";
5602 	case VAR_SPECIAL:
5603 	    STRCPY(buf, get_var_special_name(varp->vval.v_number));
5604 	    return buf;
5605         case VAR_BLOB:
5606 	    emsg(_("E976: using Blob as a String"));
5607 	    break;
5608 	case VAR_JOB:
5609 #ifdef FEAT_JOB_CHANNEL
5610 	    {
5611 		job_T *job = varp->vval.v_job;
5612 		char  *status;
5613 
5614 		if (job == NULL)
5615 		    return (char_u *)"no process";
5616 		status = job->jv_status == JOB_FAILED ? "fail"
5617 				: job->jv_status >= JOB_ENDED ? "dead"
5618 				: "run";
5619 # ifdef UNIX
5620 		vim_snprintf((char *)buf, NUMBUFLEN,
5621 			    "process %ld %s", (long)job->jv_pid, status);
5622 # elif defined(MSWIN)
5623 		vim_snprintf((char *)buf, NUMBUFLEN,
5624 			    "process %ld %s",
5625 			    (long)job->jv_proc_info.dwProcessId,
5626 			    status);
5627 # else
5628 		// fall-back
5629 		vim_snprintf((char *)buf, NUMBUFLEN, "process ? %s", status);
5630 # endif
5631 		return buf;
5632 	    }
5633 #endif
5634 	    break;
5635 	case VAR_CHANNEL:
5636 #ifdef FEAT_JOB_CHANNEL
5637 	    {
5638 		channel_T *channel = varp->vval.v_channel;
5639 		char      *status = channel_status(channel, -1);
5640 
5641 		if (channel == NULL)
5642 		    vim_snprintf((char *)buf, NUMBUFLEN, "channel %s", status);
5643 		else
5644 		    vim_snprintf((char *)buf, NUMBUFLEN,
5645 				     "channel %d %s", channel->ch_id, status);
5646 		return buf;
5647 	    }
5648 #endif
5649 	    break;
5650 	case VAR_UNKNOWN:
5651 	    emsg(_("E908: using an invalid value as a String"));
5652 	    break;
5653     }
5654     return NULL;
5655 }
5656 
5657 /*
5658  * Turn a typeval into a string.  Similar to tv_get_string_buf() but uses
5659  * string() on Dict, List, etc.
5660  */
5661     static char_u *
5662 tv_stringify(typval_T *varp, char_u *buf)
5663 {
5664     if (varp->v_type == VAR_LIST
5665 	    || varp->v_type == VAR_DICT
5666 	    || varp->v_type == VAR_FUNC
5667 	    || varp->v_type == VAR_PARTIAL
5668 	    || varp->v_type == VAR_FLOAT)
5669     {
5670 	typval_T tmp;
5671 
5672 	f_string(varp, &tmp);
5673 	tv_get_string_buf(&tmp, buf);
5674 	clear_tv(varp);
5675 	*varp = tmp;
5676 	return tmp.vval.v_string;
5677     }
5678     return tv_get_string_buf(varp, buf);
5679 }
5680 
5681 /*
5682  * Return TRUE if typeval "tv" and its value are set to be locked (immutable).
5683  * Also give an error message, using "name" or _("name") when use_gettext is
5684  * TRUE.
5685  */
5686     static int
5687 tv_check_lock(typval_T *tv, char_u *name, int use_gettext)
5688 {
5689     int	lock = 0;
5690 
5691     switch (tv->v_type)
5692     {
5693 	case VAR_BLOB:
5694 	    if (tv->vval.v_blob != NULL)
5695 		lock = tv->vval.v_blob->bv_lock;
5696 	    break;
5697 	case VAR_LIST:
5698 	    if (tv->vval.v_list != NULL)
5699 		lock = tv->vval.v_list->lv_lock;
5700 	    break;
5701 	case VAR_DICT:
5702 	    if (tv->vval.v_dict != NULL)
5703 		lock = tv->vval.v_dict->dv_lock;
5704 	    break;
5705 	default:
5706 	    break;
5707     }
5708     return var_check_lock(tv->v_lock, name, use_gettext)
5709 		    || (lock != 0 && var_check_lock(lock, name, use_gettext));
5710 }
5711 
5712 /*
5713  * Copy the values from typval_T "from" to typval_T "to".
5714  * When needed allocates string or increases reference count.
5715  * Does not make a copy of a list, blob or dict but copies the reference!
5716  * It is OK for "from" and "to" to point to the same item.  This is used to
5717  * make a copy later.
5718  */
5719     void
5720 copy_tv(typval_T *from, typval_T *to)
5721 {
5722     to->v_type = from->v_type;
5723     to->v_lock = 0;
5724     switch (from->v_type)
5725     {
5726 	case VAR_NUMBER:
5727 	case VAR_SPECIAL:
5728 	    to->vval.v_number = from->vval.v_number;
5729 	    break;
5730 	case VAR_FLOAT:
5731 #ifdef FEAT_FLOAT
5732 	    to->vval.v_float = from->vval.v_float;
5733 	    break;
5734 #endif
5735 	case VAR_JOB:
5736 #ifdef FEAT_JOB_CHANNEL
5737 	    to->vval.v_job = from->vval.v_job;
5738 	    if (to->vval.v_job != NULL)
5739 		++to->vval.v_job->jv_refcount;
5740 	    break;
5741 #endif
5742 	case VAR_CHANNEL:
5743 #ifdef FEAT_JOB_CHANNEL
5744 	    to->vval.v_channel = from->vval.v_channel;
5745 	    if (to->vval.v_channel != NULL)
5746 		++to->vval.v_channel->ch_refcount;
5747 	    break;
5748 #endif
5749 	case VAR_STRING:
5750 	case VAR_FUNC:
5751 	    if (from->vval.v_string == NULL)
5752 		to->vval.v_string = NULL;
5753 	    else
5754 	    {
5755 		to->vval.v_string = vim_strsave(from->vval.v_string);
5756 		if (from->v_type == VAR_FUNC)
5757 		    func_ref(to->vval.v_string);
5758 	    }
5759 	    break;
5760 	case VAR_PARTIAL:
5761 	    if (from->vval.v_partial == NULL)
5762 		to->vval.v_partial = NULL;
5763 	    else
5764 	    {
5765 		to->vval.v_partial = from->vval.v_partial;
5766 		++to->vval.v_partial->pt_refcount;
5767 	    }
5768 	    break;
5769 	case VAR_BLOB:
5770 	    if (from->vval.v_blob == NULL)
5771 		to->vval.v_blob = NULL;
5772 	    else
5773 	    {
5774 		to->vval.v_blob = from->vval.v_blob;
5775 		++to->vval.v_blob->bv_refcount;
5776 	    }
5777 	    break;
5778 	case VAR_LIST:
5779 	    if (from->vval.v_list == NULL)
5780 		to->vval.v_list = NULL;
5781 	    else
5782 	    {
5783 		to->vval.v_list = from->vval.v_list;
5784 		++to->vval.v_list->lv_refcount;
5785 	    }
5786 	    break;
5787 	case VAR_DICT:
5788 	    if (from->vval.v_dict == NULL)
5789 		to->vval.v_dict = NULL;
5790 	    else
5791 	    {
5792 		to->vval.v_dict = from->vval.v_dict;
5793 		++to->vval.v_dict->dv_refcount;
5794 	    }
5795 	    break;
5796 	case VAR_UNKNOWN:
5797 	    internal_error("copy_tv(UNKNOWN)");
5798 	    break;
5799     }
5800 }
5801 
5802 /*
5803  * Make a copy of an item.
5804  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5805  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5806  * reference to an already copied list/dict can be used.
5807  * Returns FAIL or OK.
5808  */
5809     int
5810 item_copy(
5811     typval_T	*from,
5812     typval_T	*to,
5813     int		deep,
5814     int		copyID)
5815 {
5816     static int	recurse = 0;
5817     int		ret = OK;
5818 
5819     if (recurse >= DICT_MAXNEST)
5820     {
5821 	emsg(_("E698: variable nested too deep for making a copy"));
5822 	return FAIL;
5823     }
5824     ++recurse;
5825 
5826     switch (from->v_type)
5827     {
5828 	case VAR_NUMBER:
5829 	case VAR_FLOAT:
5830 	case VAR_STRING:
5831 	case VAR_FUNC:
5832 	case VAR_PARTIAL:
5833 	case VAR_SPECIAL:
5834 	case VAR_JOB:
5835 	case VAR_CHANNEL:
5836 	    copy_tv(from, to);
5837 	    break;
5838 	case VAR_LIST:
5839 	    to->v_type = VAR_LIST;
5840 	    to->v_lock = 0;
5841 	    if (from->vval.v_list == NULL)
5842 		to->vval.v_list = NULL;
5843 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
5844 	    {
5845 		// use the copy made earlier
5846 		to->vval.v_list = from->vval.v_list->lv_copylist;
5847 		++to->vval.v_list->lv_refcount;
5848 	    }
5849 	    else
5850 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
5851 	    if (to->vval.v_list == NULL)
5852 		ret = FAIL;
5853 	    break;
5854 	case VAR_BLOB:
5855 	    ret = blob_copy(from, to);
5856 	    break;
5857 	case VAR_DICT:
5858 	    to->v_type = VAR_DICT;
5859 	    to->v_lock = 0;
5860 	    if (from->vval.v_dict == NULL)
5861 		to->vval.v_dict = NULL;
5862 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
5863 	    {
5864 		// use the copy made earlier
5865 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
5866 		++to->vval.v_dict->dv_refcount;
5867 	    }
5868 	    else
5869 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
5870 	    if (to->vval.v_dict == NULL)
5871 		ret = FAIL;
5872 	    break;
5873 	case VAR_UNKNOWN:
5874 	    internal_error("item_copy(UNKNOWN)");
5875 	    ret = FAIL;
5876     }
5877     --recurse;
5878     return ret;
5879 }
5880 
5881 /*
5882  * ":echo expr1 ..."	print each argument separated with a space, add a
5883  *			newline at the end.
5884  * ":echon expr1 ..."	print each argument plain.
5885  */
5886     void
5887 ex_echo(exarg_T *eap)
5888 {
5889     char_u	*arg = eap->arg;
5890     typval_T	rettv;
5891     char_u	*tofree;
5892     char_u	*p;
5893     int		needclr = TRUE;
5894     int		atstart = TRUE;
5895     char_u	numbuf[NUMBUFLEN];
5896     int		did_emsg_before = did_emsg;
5897     int		called_emsg_before = called_emsg;
5898 
5899     if (eap->skip)
5900 	++emsg_skip;
5901     while (*arg != NUL && *arg != '|' && *arg != '\n' && !got_int)
5902     {
5903 	// If eval1() causes an error message the text from the command may
5904 	// still need to be cleared. E.g., "echo 22,44".
5905 	need_clr_eos = needclr;
5906 
5907 	p = arg;
5908 	if (eval1(&arg, &rettv, !eap->skip) == FAIL)
5909 	{
5910 	    /*
5911 	     * Report the invalid expression unless the expression evaluation
5912 	     * has been cancelled due to an aborting error, an interrupt, or an
5913 	     * exception.
5914 	     */
5915 	    if (!aborting() && did_emsg == did_emsg_before
5916 					  && called_emsg == called_emsg_before)
5917 		semsg(_(e_invexpr2), p);
5918 	    need_clr_eos = FALSE;
5919 	    break;
5920 	}
5921 	need_clr_eos = FALSE;
5922 
5923 	if (!eap->skip)
5924 	{
5925 	    if (atstart)
5926 	    {
5927 		atstart = FALSE;
5928 		// Call msg_start() after eval1(), evaluating the expression
5929 		// may cause a message to appear.
5930 		if (eap->cmdidx == CMD_echo)
5931 		{
5932 		    // Mark the saved text as finishing the line, so that what
5933 		    // follows is displayed on a new line when scrolling back
5934 		    // at the more prompt.
5935 		    msg_sb_eol();
5936 		    msg_start();
5937 		}
5938 	    }
5939 	    else if (eap->cmdidx == CMD_echo)
5940 		msg_puts_attr(" ", echo_attr);
5941 	    p = echo_string(&rettv, &tofree, numbuf, get_copyID());
5942 	    if (p != NULL)
5943 		for ( ; *p != NUL && !got_int; ++p)
5944 		{
5945 		    if (*p == '\n' || *p == '\r' || *p == TAB)
5946 		    {
5947 			if (*p != TAB && needclr)
5948 			{
5949 			    // remove any text still there from the command
5950 			    msg_clr_eos();
5951 			    needclr = FALSE;
5952 			}
5953 			msg_putchar_attr(*p, echo_attr);
5954 		    }
5955 		    else
5956 		    {
5957 			if (has_mbyte)
5958 			{
5959 			    int i = (*mb_ptr2len)(p);
5960 
5961 			    (void)msg_outtrans_len_attr(p, i, echo_attr);
5962 			    p += i - 1;
5963 			}
5964 			else
5965 			    (void)msg_outtrans_len_attr(p, 1, echo_attr);
5966 		    }
5967 		}
5968 	    vim_free(tofree);
5969 	}
5970 	clear_tv(&rettv);
5971 	arg = skipwhite(arg);
5972     }
5973     eap->nextcmd = check_nextcmd(arg);
5974 
5975     if (eap->skip)
5976 	--emsg_skip;
5977     else
5978     {
5979 	// remove text that may still be there from the command
5980 	if (needclr)
5981 	    msg_clr_eos();
5982 	if (eap->cmdidx == CMD_echo)
5983 	    msg_end();
5984     }
5985 }
5986 
5987 /*
5988  * ":echohl {name}".
5989  */
5990     void
5991 ex_echohl(exarg_T *eap)
5992 {
5993     echo_attr = syn_name2attr(eap->arg);
5994 }
5995 
5996 /*
5997  * Returns the :echo attribute
5998  */
5999     int
6000 get_echo_attr(void)
6001 {
6002     return echo_attr;
6003 }
6004 
6005 /*
6006  * ":execute expr1 ..."	execute the result of an expression.
6007  * ":echomsg expr1 ..."	Print a message
6008  * ":echoerr expr1 ..."	Print an error
6009  * Each gets spaces around each argument and a newline at the end for
6010  * echo commands
6011  */
6012     void
6013 ex_execute(exarg_T *eap)
6014 {
6015     char_u	*arg = eap->arg;
6016     typval_T	rettv;
6017     int		ret = OK;
6018     char_u	*p;
6019     garray_T	ga;
6020     int		len;
6021     int		save_did_emsg;
6022 
6023     ga_init2(&ga, 1, 80);
6024 
6025     if (eap->skip)
6026 	++emsg_skip;
6027     while (*arg != NUL && *arg != '|' && *arg != '\n')
6028     {
6029 	ret = eval1_emsg(&arg, &rettv, !eap->skip);
6030 	if (ret == FAIL)
6031 	    break;
6032 
6033 	if (!eap->skip)
6034 	{
6035 	    char_u   buf[NUMBUFLEN];
6036 
6037 	    if (eap->cmdidx == CMD_execute)
6038 		p = tv_get_string_buf(&rettv, buf);
6039 	    else
6040 		p = tv_stringify(&rettv, buf);
6041 	    len = (int)STRLEN(p);
6042 	    if (ga_grow(&ga, len + 2) == FAIL)
6043 	    {
6044 		clear_tv(&rettv);
6045 		ret = FAIL;
6046 		break;
6047 	    }
6048 	    if (ga.ga_len)
6049 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
6050 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
6051 	    ga.ga_len += len;
6052 	}
6053 
6054 	clear_tv(&rettv);
6055 	arg = skipwhite(arg);
6056     }
6057 
6058     if (ret != FAIL && ga.ga_data != NULL)
6059     {
6060 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
6061 	{
6062 	    // Mark the already saved text as finishing the line, so that what
6063 	    // follows is displayed on a new line when scrolling back at the
6064 	    // more prompt.
6065 	    msg_sb_eol();
6066 	}
6067 
6068 	if (eap->cmdidx == CMD_echomsg)
6069 	{
6070 	    msg_attr(ga.ga_data, echo_attr);
6071 	    out_flush();
6072 	}
6073 	else if (eap->cmdidx == CMD_echoerr)
6074 	{
6075 	    // We don't want to abort following commands, restore did_emsg.
6076 	    save_did_emsg = did_emsg;
6077 	    emsg(ga.ga_data);
6078 	    if (!force_abort)
6079 		did_emsg = save_did_emsg;
6080 	}
6081 	else if (eap->cmdidx == CMD_execute)
6082 	    do_cmdline((char_u *)ga.ga_data,
6083 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
6084     }
6085 
6086     ga_clear(&ga);
6087 
6088     if (eap->skip)
6089 	--emsg_skip;
6090 
6091     eap->nextcmd = check_nextcmd(arg);
6092 }
6093 
6094 /*
6095  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
6096  * "arg" points to the "&" or '+' when called, to "option" when returning.
6097  * Returns NULL when no option name found.  Otherwise pointer to the char
6098  * after the option name.
6099  */
6100     char_u *
6101 find_option_end(char_u **arg, int *opt_flags)
6102 {
6103     char_u	*p = *arg;
6104 
6105     ++p;
6106     if (*p == 'g' && p[1] == ':')
6107     {
6108 	*opt_flags = OPT_GLOBAL;
6109 	p += 2;
6110     }
6111     else if (*p == 'l' && p[1] == ':')
6112     {
6113 	*opt_flags = OPT_LOCAL;
6114 	p += 2;
6115     }
6116     else
6117 	*opt_flags = 0;
6118 
6119     if (!ASCII_ISALPHA(*p))
6120 	return NULL;
6121     *arg = p;
6122 
6123     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
6124 	p += 4;	    // termcap option
6125     else
6126 	while (ASCII_ISALPHA(*p))
6127 	    ++p;
6128     return p;
6129 }
6130 
6131 /*
6132  * Display script name where an item was last set.
6133  * Should only be invoked when 'verbose' is non-zero.
6134  */
6135     void
6136 last_set_msg(sctx_T script_ctx)
6137 {
6138     char_u *p;
6139 
6140     if (script_ctx.sc_sid != 0)
6141     {
6142 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
6143 	if (p != NULL)
6144 	{
6145 	    verbose_enter();
6146 	    msg_puts(_("\n\tLast set from "));
6147 	    msg_puts((char *)p);
6148 	    if (script_ctx.sc_lnum > 0)
6149 	    {
6150 		msg_puts(_(" line "));
6151 		msg_outnum((long)script_ctx.sc_lnum);
6152 	    }
6153 	    verbose_leave();
6154 	    vim_free(p);
6155 	}
6156     }
6157 }
6158 
6159 /*
6160  * Compare "typ1" and "typ2".  Put the result in "typ1".
6161  */
6162     int
6163 typval_compare(
6164     typval_T	*typ1,   // first operand
6165     typval_T	*typ2,   // second operand
6166     exptype_T	type,    // operator
6167     int		type_is, // TRUE for "is" and "isnot"
6168     int		ic)      // ignore case
6169 {
6170     int		i;
6171     varnumber_T	n1, n2;
6172     char_u	*s1, *s2;
6173     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
6174 
6175     if (type_is && typ1->v_type != typ2->v_type)
6176     {
6177 	// For "is" a different type always means FALSE, for "notis"
6178 	// it means TRUE.
6179 	n1 = (type == TYPE_NEQUAL);
6180     }
6181     else if (typ1->v_type == VAR_BLOB || typ2->v_type == VAR_BLOB)
6182     {
6183 	if (type_is)
6184 	{
6185 	    n1 = (typ1->v_type == typ2->v_type
6186 			    && typ1->vval.v_blob == typ2->vval.v_blob);
6187 	    if (type == TYPE_NEQUAL)
6188 		n1 = !n1;
6189 	}
6190 	else if (typ1->v_type != typ2->v_type
6191 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
6192 	{
6193 	    if (typ1->v_type != typ2->v_type)
6194 		emsg(_("E977: Can only compare Blob with Blob"));
6195 	    else
6196 		emsg(_(e_invalblob));
6197 	    clear_tv(typ1);
6198 	    return FAIL;
6199 	}
6200 	else
6201 	{
6202 	    // Compare two Blobs for being equal or unequal.
6203 	    n1 = blob_equal(typ1->vval.v_blob, typ2->vval.v_blob);
6204 	    if (type == TYPE_NEQUAL)
6205 		n1 = !n1;
6206 	}
6207     }
6208     else if (typ1->v_type == VAR_LIST || typ2->v_type == VAR_LIST)
6209     {
6210 	if (type_is)
6211 	{
6212 	    n1 = (typ1->v_type == typ2->v_type
6213 			    && typ1->vval.v_list == typ2->vval.v_list);
6214 	    if (type == TYPE_NEQUAL)
6215 		n1 = !n1;
6216 	}
6217 	else if (typ1->v_type != typ2->v_type
6218 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
6219 	{
6220 	    if (typ1->v_type != typ2->v_type)
6221 		emsg(_("E691: Can only compare List with List"));
6222 	    else
6223 		emsg(_("E692: Invalid operation for List"));
6224 	    clear_tv(typ1);
6225 	    return FAIL;
6226 	}
6227 	else
6228 	{
6229 	    // Compare two Lists for being equal or unequal.
6230 	    n1 = list_equal(typ1->vval.v_list, typ2->vval.v_list,
6231 							    ic, FALSE);
6232 	    if (type == TYPE_NEQUAL)
6233 		n1 = !n1;
6234 	}
6235     }
6236 
6237     else if (typ1->v_type == VAR_DICT || typ2->v_type == VAR_DICT)
6238     {
6239 	if (type_is)
6240 	{
6241 	    n1 = (typ1->v_type == typ2->v_type
6242 			    && typ1->vval.v_dict == typ2->vval.v_dict);
6243 	    if (type == TYPE_NEQUAL)
6244 		n1 = !n1;
6245 	}
6246 	else if (typ1->v_type != typ2->v_type
6247 		|| (type != TYPE_EQUAL && type != TYPE_NEQUAL))
6248 	{
6249 	    if (typ1->v_type != typ2->v_type)
6250 		emsg(_("E735: Can only compare Dictionary with Dictionary"));
6251 	    else
6252 		emsg(_("E736: Invalid operation for Dictionary"));
6253 	    clear_tv(typ1);
6254 	    return FAIL;
6255 	}
6256 	else
6257 	{
6258 	    // Compare two Dictionaries for being equal or unequal.
6259 	    n1 = dict_equal(typ1->vval.v_dict, typ2->vval.v_dict,
6260 							    ic, FALSE);
6261 	    if (type == TYPE_NEQUAL)
6262 		n1 = !n1;
6263 	}
6264     }
6265 
6266     else if (typ1->v_type == VAR_FUNC || typ2->v_type == VAR_FUNC
6267 	|| typ1->v_type == VAR_PARTIAL || typ2->v_type == VAR_PARTIAL)
6268     {
6269 	if (type != TYPE_EQUAL && type != TYPE_NEQUAL)
6270 	{
6271 	    emsg(_("E694: Invalid operation for Funcrefs"));
6272 	    clear_tv(typ1);
6273 	    return FAIL;
6274 	}
6275 	if ((typ1->v_type == VAR_PARTIAL
6276 					&& typ1->vval.v_partial == NULL)
6277 		|| (typ2->v_type == VAR_PARTIAL
6278 					&& typ2->vval.v_partial == NULL))
6279 	    // when a partial is NULL assume not equal
6280 	    n1 = FALSE;
6281 	else if (type_is)
6282 	{
6283 	    if (typ1->v_type == VAR_FUNC && typ2->v_type == VAR_FUNC)
6284 		// strings are considered the same if their value is
6285 		// the same
6286 		n1 = tv_equal(typ1, typ2, ic, FALSE);
6287 	    else if (typ1->v_type == VAR_PARTIAL
6288 					&& typ2->v_type == VAR_PARTIAL)
6289 		n1 = (typ1->vval.v_partial == typ2->vval.v_partial);
6290 	    else
6291 		n1 = FALSE;
6292 	}
6293 	else
6294 	    n1 = tv_equal(typ1, typ2, ic, FALSE);
6295 	if (type == TYPE_NEQUAL)
6296 	    n1 = !n1;
6297     }
6298 
6299 #ifdef FEAT_FLOAT
6300     /*
6301 	* If one of the two variables is a float, compare as a float.
6302 	* When using "=~" or "!~", always compare as string.
6303 	*/
6304     else if ((typ1->v_type == VAR_FLOAT || typ2->v_type == VAR_FLOAT)
6305 	    && type != TYPE_MATCH && type != TYPE_NOMATCH)
6306     {
6307 	float_T f1, f2;
6308 
6309 	f1 = tv_get_float(typ1);
6310 	f2 = tv_get_float(typ2);
6311 	n1 = FALSE;
6312 	switch (type)
6313 	{
6314 	    case TYPE_EQUAL:    n1 = (f1 == f2); break;
6315 	    case TYPE_NEQUAL:   n1 = (f1 != f2); break;
6316 	    case TYPE_GREATER:  n1 = (f1 > f2); break;
6317 	    case TYPE_GEQUAL:   n1 = (f1 >= f2); break;
6318 	    case TYPE_SMALLER:  n1 = (f1 < f2); break;
6319 	    case TYPE_SEQUAL:   n1 = (f1 <= f2); break;
6320 	    case TYPE_UNKNOWN:
6321 	    case TYPE_MATCH:
6322 	    case TYPE_NOMATCH:  break;  // avoid gcc warning
6323 	}
6324     }
6325 #endif
6326 
6327     /*
6328 	* If one of the two variables is a number, compare as a number.
6329 	* When using "=~" or "!~", always compare as string.
6330 	*/
6331     else if ((typ1->v_type == VAR_NUMBER || typ2->v_type == VAR_NUMBER)
6332 	    && type != TYPE_MATCH && type != TYPE_NOMATCH)
6333     {
6334 	n1 = tv_get_number(typ1);
6335 	n2 = tv_get_number(typ2);
6336 	switch (type)
6337 	{
6338 	    case TYPE_EQUAL:    n1 = (n1 == n2); break;
6339 	    case TYPE_NEQUAL:   n1 = (n1 != n2); break;
6340 	    case TYPE_GREATER:  n1 = (n1 > n2); break;
6341 	    case TYPE_GEQUAL:   n1 = (n1 >= n2); break;
6342 	    case TYPE_SMALLER:  n1 = (n1 < n2); break;
6343 	    case TYPE_SEQUAL:   n1 = (n1 <= n2); break;
6344 	    case TYPE_UNKNOWN:
6345 	    case TYPE_MATCH:
6346 	    case TYPE_NOMATCH:  break;  // avoid gcc warning
6347 	}
6348     }
6349     else
6350     {
6351 	s1 = tv_get_string_buf(typ1, buf1);
6352 	s2 = tv_get_string_buf(typ2, buf2);
6353 	if (type != TYPE_MATCH && type != TYPE_NOMATCH)
6354 	    i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
6355 	else
6356 	    i = 0;
6357 	n1 = FALSE;
6358 	switch (type)
6359 	{
6360 	    case TYPE_EQUAL:    n1 = (i == 0); break;
6361 	    case TYPE_NEQUAL:   n1 = (i != 0); break;
6362 	    case TYPE_GREATER:  n1 = (i > 0); break;
6363 	    case TYPE_GEQUAL:   n1 = (i >= 0); break;
6364 	    case TYPE_SMALLER:  n1 = (i < 0); break;
6365 	    case TYPE_SEQUAL:   n1 = (i <= 0); break;
6366 
6367 	    case TYPE_MATCH:
6368 	    case TYPE_NOMATCH:
6369 		    n1 = pattern_match(s2, s1, ic);
6370 		    if (type == TYPE_NOMATCH)
6371 			n1 = !n1;
6372 		    break;
6373 
6374 	    case TYPE_UNKNOWN:  break;  // avoid gcc warning
6375 	}
6376     }
6377     clear_tv(typ1);
6378     typ1->v_type = VAR_NUMBER;
6379     typ1->vval.v_number = n1;
6380 
6381     return OK;
6382 }
6383 
6384     char_u *
6385 typval_tostring(typval_T *arg)
6386 {
6387     char_u	*tofree;
6388     char_u	numbuf[NUMBUFLEN];
6389     char_u	*ret = NULL;
6390 
6391     if (arg == NULL)
6392 	return vim_strsave((char_u *)"(does not exist)");
6393     ret = tv2string(arg, &tofree, numbuf, 0);
6394     // Make a copy if we have a value but it's not in allocated memory.
6395     if (ret != NULL && tofree == NULL)
6396 	ret = vim_strsave(ret);
6397     return ret;
6398 }
6399 
6400 #endif // FEAT_EVAL
6401 
6402 /*
6403  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
6404  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
6405  * "flags" can be "g" to do a global substitute.
6406  * Returns an allocated string, NULL for error.
6407  */
6408     char_u *
6409 do_string_sub(
6410     char_u	*str,
6411     char_u	*pat,
6412     char_u	*sub,
6413     typval_T	*expr,
6414     char_u	*flags)
6415 {
6416     int		sublen;
6417     regmatch_T	regmatch;
6418     int		i;
6419     int		do_all;
6420     char_u	*tail;
6421     char_u	*end;
6422     garray_T	ga;
6423     char_u	*ret;
6424     char_u	*save_cpo;
6425     char_u	*zero_width = NULL;
6426 
6427     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
6428     save_cpo = p_cpo;
6429     p_cpo = empty_option;
6430 
6431     ga_init2(&ga, 1, 200);
6432 
6433     do_all = (flags[0] == 'g');
6434 
6435     regmatch.rm_ic = p_ic;
6436     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
6437     if (regmatch.regprog != NULL)
6438     {
6439 	tail = str;
6440 	end = str + STRLEN(str);
6441 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
6442 	{
6443 	    // Skip empty match except for first match.
6444 	    if (regmatch.startp[0] == regmatch.endp[0])
6445 	    {
6446 		if (zero_width == regmatch.startp[0])
6447 		{
6448 		    // avoid getting stuck on a match with an empty string
6449 		    i = mb_ptr2len(tail);
6450 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
6451 								   (size_t)i);
6452 		    ga.ga_len += i;
6453 		    tail += i;
6454 		    continue;
6455 		}
6456 		zero_width = regmatch.startp[0];
6457 	    }
6458 
6459 	    /*
6460 	     * Get some space for a temporary buffer to do the substitution
6461 	     * into.  It will contain:
6462 	     * - The text up to where the match is.
6463 	     * - The substituted text.
6464 	     * - The text after the match.
6465 	     */
6466 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
6467 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
6468 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
6469 	    {
6470 		ga_clear(&ga);
6471 		break;
6472 	    }
6473 
6474 	    // copy the text up to where the match is
6475 	    i = (int)(regmatch.startp[0] - tail);
6476 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
6477 	    // add the substituted text
6478 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
6479 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
6480 	    ga.ga_len += i + sublen - 1;
6481 	    tail = regmatch.endp[0];
6482 	    if (*tail == NUL)
6483 		break;
6484 	    if (!do_all)
6485 		break;
6486 	}
6487 
6488 	if (ga.ga_data != NULL)
6489 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
6490 
6491 	vim_regfree(regmatch.regprog);
6492     }
6493 
6494     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
6495     ga_clear(&ga);
6496     if (p_cpo == empty_option)
6497 	p_cpo = save_cpo;
6498     else
6499 	// Darn, evaluating {sub} expression or {expr} changed the value.
6500 	free_string_option(save_cpo);
6501 
6502     return ret;
6503 }
6504