xref: /vim-8.2.3635/src/eval.c (revision 7ff78465)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * eval.c: Expression evaluation.
12  */
13 #define USING_FLOAT_STUFF
14 
15 #include "vim.h"
16 
17 #if defined(FEAT_EVAL) || defined(PROTO)
18 
19 #ifdef VMS
20 # include <float.h>
21 #endif
22 
23 static char *e_dictrange = N_("E719: Cannot use [:] with a Dictionary");
24 
25 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
26 
27 /*
28  * When recursively copying lists and dicts we need to remember which ones we
29  * have done to avoid endless recursiveness.  This unique ID is used for that.
30  * The last bit is used for previous_funccal, ignored when comparing.
31  */
32 static int current_copyID = 0;
33 
34 /*
35  * Info used by a ":for" loop.
36  */
37 typedef struct
38 {
39     int		fi_semicolon;	// TRUE if ending in '; var]'
40     int		fi_varcount;	// nr of variables in the list
41     int		fi_break_count;	// nr of line breaks encountered
42     listwatch_T	fi_lw;		// keep an eye on the item used.
43     list_T	*fi_list;	// list being used
44     int		fi_bi;		// index of blob
45     blob_T	*fi_blob;	// blob being used
46 } forinfo_T;
47 
48 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
49 static int eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
50 static int eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
51 static int eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
52 static int eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
53 static int eval6(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int want_string);
54 static int eval7(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int want_string);
55 static int eval7_leader(typval_T *rettv, int numeric_only, char_u *start_leader, char_u **end_leaderp);
56 
57 static int free_unref_items(int copyID);
58 static char_u *make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
59 
60 /*
61  * Return "n1" divided by "n2", taking care of dividing by zero.
62  */
63 	varnumber_T
64 num_divide(varnumber_T n1, varnumber_T n2)
65 {
66     varnumber_T	result;
67 
68     if (n2 == 0)	// give an error message?
69     {
70 	if (n1 == 0)
71 	    result = VARNUM_MIN; // similar to NaN
72 	else if (n1 < 0)
73 	    result = -VARNUM_MAX;
74 	else
75 	    result = VARNUM_MAX;
76     }
77     else
78 	result = n1 / n2;
79 
80     return result;
81 }
82 
83 /*
84  * Return "n1" modulus "n2", taking care of dividing by zero.
85  */
86 	varnumber_T
87 num_modulus(varnumber_T n1, varnumber_T n2)
88 {
89     // Give an error when n2 is 0?
90     return (n2 == 0) ? 0 : (n1 % n2);
91 }
92 
93 #if defined(EBCDIC) || defined(PROTO)
94 /*
95  * Compare struct fst by function name.
96  */
97     static int
98 compare_func_name(const void *s1, const void *s2)
99 {
100     struct fst *p1 = (struct fst *)s1;
101     struct fst *p2 = (struct fst *)s2;
102 
103     return STRCMP(p1->f_name, p2->f_name);
104 }
105 
106 /*
107  * Sort the function table by function name.
108  * The sorting of the table above is ASCII dependent.
109  * On machines using EBCDIC we have to sort it.
110  */
111     static void
112 sortFunctions(void)
113 {
114     int		funcCnt = (int)(sizeof(functions) / sizeof(struct fst)) - 1;
115 
116     qsort(functions, (size_t)funcCnt, sizeof(struct fst), compare_func_name);
117 }
118 #endif
119 
120 /*
121  * Initialize the global and v: variables.
122  */
123     void
124 eval_init(void)
125 {
126     evalvars_init();
127     func_init();
128 
129 #ifdef EBCDIC
130     /*
131      * Sort the function table, to enable binary search.
132      */
133     sortFunctions();
134 #endif
135 }
136 
137 #if defined(EXITFREE) || defined(PROTO)
138     void
139 eval_clear(void)
140 {
141     evalvars_clear();
142     free_scriptnames();  // must come after evalvars_clear().
143     free_locales();
144 
145     // autoloaded script names
146     free_autoload_scriptnames();
147 
148     // unreferenced lists and dicts
149     (void)garbage_collect(FALSE);
150 
151     // functions not garbage collected
152     free_all_functions();
153 }
154 #endif
155 
156     void
157 fill_evalarg_from_eap(evalarg_T *evalarg, exarg_T *eap, int skip)
158 {
159     CLEAR_FIELD(*evalarg);
160     evalarg->eval_flags = skip ? 0 : EVAL_EVALUATE;
161     if (eap != NULL && getline_equal(eap->getline, eap->cookie, getsourceline))
162     {
163 	evalarg->eval_getline = eap->getline;
164 	evalarg->eval_cookie = eap->cookie;
165     }
166 }
167 
168 /*
169  * Top level evaluation function, returning a boolean.
170  * Sets "error" to TRUE if there was an error.
171  * Return TRUE or FALSE.
172  */
173     int
174 eval_to_bool(
175     char_u	*arg,
176     int		*error,
177     exarg_T	*eap,
178     int		skip)	    // only parse, don't execute
179 {
180     typval_T	tv;
181     varnumber_T	retval = FALSE;
182     evalarg_T	evalarg;
183 
184     fill_evalarg_from_eap(&evalarg, eap, skip);
185 
186     if (skip)
187 	++emsg_skip;
188     if (eval0(arg, &tv, eap, &evalarg) == FAIL)
189 	*error = TRUE;
190     else
191     {
192 	*error = FALSE;
193 	if (!skip)
194 	{
195 	    retval = (tv_get_number_chk(&tv, error) != 0);
196 	    clear_tv(&tv);
197 	}
198     }
199     if (skip)
200 	--emsg_skip;
201     clear_evalarg(&evalarg, eap);
202 
203     return (int)retval;
204 }
205 
206 /*
207  * Call eval1() and give an error message if not done at a lower level.
208  */
209     static int
210 eval1_emsg(char_u **arg, typval_T *rettv, exarg_T *eap)
211 {
212     char_u	*start = *arg;
213     int		ret;
214     int		did_emsg_before = did_emsg;
215     int		called_emsg_before = called_emsg;
216     evalarg_T	evalarg;
217 
218     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
219 
220     ret = eval1(arg, rettv, &evalarg);
221     if (ret == FAIL)
222     {
223 	// Report the invalid expression unless the expression evaluation has
224 	// been cancelled due to an aborting error, an interrupt, or an
225 	// exception, or we already gave a more specific error.
226 	// Also check called_emsg for when using assert_fails().
227 	if (!aborting() && did_emsg == did_emsg_before
228 					  && called_emsg == called_emsg_before)
229 	    semsg(_(e_invexpr2), start);
230     }
231     clear_evalarg(&evalarg, eap);
232     return ret;
233 }
234 
235 /*
236  * Return whether a typval is a valid expression to pass to eval_expr_typval()
237  * or eval_expr_to_bool().  An empty string returns FALSE;
238  */
239     int
240 eval_expr_valid_arg(typval_T *tv)
241 {
242     return tv->v_type != VAR_UNKNOWN
243 	    && (tv->v_type != VAR_STRING
244 		  || (tv->vval.v_string != NULL && *tv->vval.v_string != NUL));
245 }
246 
247 /*
248  * Evaluate an expression, which can be a function, partial or string.
249  * Pass arguments "argv[argc]".
250  * Return the result in "rettv" and OK or FAIL.
251  */
252     int
253 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
254 {
255     char_u	*s;
256     char_u	buf[NUMBUFLEN];
257     funcexe_T	funcexe;
258 
259     if (expr->v_type == VAR_FUNC)
260     {
261 	s = expr->vval.v_string;
262 	if (s == NULL || *s == NUL)
263 	    return FAIL;
264 	CLEAR_FIELD(funcexe);
265 	funcexe.evaluate = TRUE;
266 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
267 	    return FAIL;
268     }
269     else if (expr->v_type == VAR_PARTIAL)
270     {
271 	partial_T   *partial = expr->vval.v_partial;
272 
273 	if (partial == NULL)
274 	    return FAIL;
275 
276 	if (partial->pt_func != NULL
277 			  && partial->pt_func->uf_def_status != UF_NOT_COMPILED)
278 	{
279 	    if (call_def_function(partial->pt_func, argc, argv,
280 						       partial, rettv) == FAIL)
281 		return FAIL;
282 	}
283 	else
284 	{
285 	    s = partial_name(partial);
286 	    if (s == NULL || *s == NUL)
287 		return FAIL;
288 	    CLEAR_FIELD(funcexe);
289 	    funcexe.evaluate = TRUE;
290 	    funcexe.partial = partial;
291 	    if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
292 		return FAIL;
293 	}
294     }
295     else
296     {
297 	s = tv_get_string_buf_chk(expr, buf);
298 	if (s == NULL)
299 	    return FAIL;
300 	s = skipwhite(s);
301 	if (eval1_emsg(&s, rettv, NULL) == FAIL)
302 	    return FAIL;
303 	if (*s != NUL)  // check for trailing chars after expr
304 	{
305 	    clear_tv(rettv);
306 	    semsg(_(e_invexpr2), s);
307 	    return FAIL;
308 	}
309     }
310     return OK;
311 }
312 
313 /*
314  * Like eval_to_bool() but using a typval_T instead of a string.
315  * Works for string, funcref and partial.
316  */
317     int
318 eval_expr_to_bool(typval_T *expr, int *error)
319 {
320     typval_T	rettv;
321     int		res;
322 
323     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
324     {
325 	*error = TRUE;
326 	return FALSE;
327     }
328     res = (tv_get_number_chk(&rettv, error) != 0);
329     clear_tv(&rettv);
330     return res;
331 }
332 
333 /*
334  * Top level evaluation function, returning a string.  If "skip" is TRUE,
335  * only parsing to "nextcmd" is done, without reporting errors.  Return
336  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
337  */
338     char_u *
339 eval_to_string_skip(
340     char_u	*arg,
341     exarg_T	*eap,
342     int		skip)	    // only parse, don't execute
343 {
344     typval_T	tv;
345     char_u	*retval;
346     evalarg_T	evalarg;
347 
348     fill_evalarg_from_eap(&evalarg, eap, skip);
349     if (skip)
350 	++emsg_skip;
351     if (eval0(arg, &tv, eap, &evalarg) == FAIL || skip)
352 	retval = NULL;
353     else
354     {
355 	retval = vim_strsave(tv_get_string(&tv));
356 	clear_tv(&tv);
357     }
358     if (skip)
359 	--emsg_skip;
360     clear_evalarg(&evalarg, eap);
361 
362     return retval;
363 }
364 
365 /*
366  * Skip over an expression at "*pp".
367  * Return FAIL for an error, OK otherwise.
368  */
369     int
370 skip_expr(char_u **pp)
371 {
372     typval_T	rettv;
373 
374     *pp = skipwhite(*pp);
375     return eval1(pp, &rettv, NULL);
376 }
377 
378 /*
379  * Skip over an expression at "*pp".
380  * If in Vim9 script and line breaks are encountered, the lines are
381  * concatenated.  "evalarg->eval_tofree" will be set accordingly.
382  * "arg" is advanced to just after the expression.
383  * "start" is set to the start of the expression, "end" to just after the end.
384  * Also when the expression is copied to allocated memory.
385  * Return FAIL for an error, OK otherwise.
386  */
387     int
388 skip_expr_concatenate(
389 	char_u	    **arg,
390 	char_u	    **start,
391 	char_u	    **end,
392 	evalarg_T   *evalarg)
393 {
394     typval_T	rettv;
395     int		res;
396     int		vim9script = current_sctx.sc_version == SCRIPT_VERSION_VIM9;
397     garray_T    *gap = &evalarg->eval_ga;
398     int		save_flags = evalarg == NULL ? 0 : evalarg->eval_flags;
399 
400     if (vim9script
401 	       && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
402     {
403 	ga_init2(gap, sizeof(char_u *), 10);
404 	// leave room for "start"
405 	if (ga_grow(gap, 1) == OK)
406 	    ++gap->ga_len;
407     }
408     *start = *arg;
409 
410     // Don't evaluate the expression.
411     if (evalarg != NULL)
412 	evalarg->eval_flags &= ~EVAL_EVALUATE;
413     *arg = skipwhite(*arg);
414     res = eval1(arg, &rettv, evalarg);
415     *end = *arg;
416     if (evalarg != NULL)
417 	evalarg->eval_flags = save_flags;
418 
419     if (vim9script
420 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
421     {
422 	if (evalarg->eval_ga.ga_len == 1)
423 	{
424 	    // just one line, no need to concatenate
425 	    ga_clear(gap);
426 	    gap->ga_itemsize = 0;
427 	}
428 	else
429 	{
430 	    char_u	    *p;
431 	    size_t	    endoff = STRLEN(*arg);
432 
433 	    // Line breaks encountered, concatenate all the lines.
434 	    *((char_u **)gap->ga_data) = *start;
435 	    p = ga_concat_strings(gap, "");
436 
437 	    // free the lines only when using getsourceline()
438 	    if (evalarg->eval_cookie != NULL)
439 	    {
440 		// Do not free the first line, the caller can still use it.
441 		*((char_u **)gap->ga_data) = NULL;
442 		// Do not free the last line, "arg" points into it, free it
443 		// later.
444 		vim_free(evalarg->eval_tofree);
445 		evalarg->eval_tofree =
446 				    ((char_u **)gap->ga_data)[gap->ga_len - 1];
447 		((char_u **)gap->ga_data)[gap->ga_len - 1] = NULL;
448 		ga_clear_strings(gap);
449 	    }
450 	    else
451 		ga_clear(gap);
452 	    gap->ga_itemsize = 0;
453 	    if (p == NULL)
454 		return FAIL;
455 	    *start = p;
456 	    vim_free(evalarg->eval_tofree_lambda);
457 	    evalarg->eval_tofree_lambda = p;
458 	    // Compute "end" relative to the end.
459 	    *end = *start + STRLEN(*start) - endoff;
460 	}
461     }
462 
463     return res;
464 }
465 
466 /*
467  * Top level evaluation function, returning a string.  Does not handle line
468  * breaks.
469  * When "convert" is TRUE convert a List into a sequence of lines and convert
470  * a Float to a String.
471  * Return pointer to allocated memory, or NULL for failure.
472  */
473     char_u *
474 eval_to_string(
475     char_u	*arg,
476     int		convert)
477 {
478     typval_T	tv;
479     char_u	*retval;
480     garray_T	ga;
481 #ifdef FEAT_FLOAT
482     char_u	numbuf[NUMBUFLEN];
483 #endif
484 
485     if (eval0(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
486 	retval = NULL;
487     else
488     {
489 	if (convert && tv.v_type == VAR_LIST)
490 	{
491 	    ga_init2(&ga, (int)sizeof(char), 80);
492 	    if (tv.vval.v_list != NULL)
493 	    {
494 		list_join(&ga, tv.vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
495 		if (tv.vval.v_list->lv_len > 0)
496 		    ga_append(&ga, NL);
497 	    }
498 	    ga_append(&ga, NUL);
499 	    retval = (char_u *)ga.ga_data;
500 	}
501 #ifdef FEAT_FLOAT
502 	else if (convert && tv.v_type == VAR_FLOAT)
503 	{
504 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv.vval.v_float);
505 	    retval = vim_strsave(numbuf);
506 	}
507 #endif
508 	else
509 	    retval = vim_strsave(tv_get_string(&tv));
510 	clear_tv(&tv);
511     }
512     clear_evalarg(&EVALARG_EVALUATE, NULL);
513 
514     return retval;
515 }
516 
517 /*
518  * Call eval_to_string() without using current local variables and using
519  * textwinlock.  When "use_sandbox" is TRUE use the sandbox.
520  */
521     char_u *
522 eval_to_string_safe(
523     char_u	*arg,
524     int		use_sandbox)
525 {
526     char_u	*retval;
527     funccal_entry_T funccal_entry;
528 
529     save_funccal(&funccal_entry);
530     if (use_sandbox)
531 	++sandbox;
532     ++textwinlock;
533     retval = eval_to_string(arg, FALSE);
534     if (use_sandbox)
535 	--sandbox;
536     --textwinlock;
537     restore_funccal();
538     return retval;
539 }
540 
541 /*
542  * Top level evaluation function, returning a number.
543  * Evaluates "expr" silently.
544  * Returns -1 for an error.
545  */
546     varnumber_T
547 eval_to_number(char_u *expr)
548 {
549     typval_T	rettv;
550     varnumber_T	retval;
551     char_u	*p = skipwhite(expr);
552 
553     ++emsg_off;
554 
555     if (eval1(&p, &rettv, &EVALARG_EVALUATE) == FAIL)
556 	retval = -1;
557     else
558     {
559 	retval = tv_get_number_chk(&rettv, NULL);
560 	clear_tv(&rettv);
561     }
562     --emsg_off;
563 
564     return retval;
565 }
566 
567 /*
568  * Top level evaluation function.
569  * Returns an allocated typval_T with the result.
570  * Returns NULL when there is an error.
571  */
572     typval_T *
573 eval_expr(char_u *arg, exarg_T *eap)
574 {
575     typval_T	*tv;
576     evalarg_T	evalarg;
577 
578     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
579 
580     tv = ALLOC_ONE(typval_T);
581     if (tv != NULL && eval0(arg, tv, eap, &evalarg) == FAIL)
582 	VIM_CLEAR(tv);
583 
584     clear_evalarg(&evalarg, eap);
585     return tv;
586 }
587 
588 /*
589  * Call some Vim script function and return the result in "*rettv".
590  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
591  * should have type VAR_UNKNOWN.
592  * Returns OK or FAIL.
593  */
594     int
595 call_vim_function(
596     char_u      *func,
597     int		argc,
598     typval_T	*argv,
599     typval_T	*rettv)
600 {
601     int		ret;
602     funcexe_T	funcexe;
603 
604     rettv->v_type = VAR_UNKNOWN;		// clear_tv() uses this
605     CLEAR_FIELD(funcexe);
606     funcexe.firstline = curwin->w_cursor.lnum;
607     funcexe.lastline = curwin->w_cursor.lnum;
608     funcexe.evaluate = TRUE;
609     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
610     if (ret == FAIL)
611 	clear_tv(rettv);
612 
613     return ret;
614 }
615 
616 /*
617  * Call Vim script function "func" and return the result as a number.
618  * Returns -1 when calling the function fails.
619  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
620  * have type VAR_UNKNOWN.
621  */
622     varnumber_T
623 call_func_retnr(
624     char_u      *func,
625     int		argc,
626     typval_T	*argv)
627 {
628     typval_T	rettv;
629     varnumber_T	retval;
630 
631     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
632 	return -1;
633 
634     retval = tv_get_number_chk(&rettv, NULL);
635     clear_tv(&rettv);
636     return retval;
637 }
638 
639 /*
640  * Call Vim script function "func" and return the result as a string.
641  * Returns NULL when calling the function fails.
642  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
643  * have type VAR_UNKNOWN.
644  */
645     void *
646 call_func_retstr(
647     char_u      *func,
648     int		argc,
649     typval_T	*argv)
650 {
651     typval_T	rettv;
652     char_u	*retval;
653 
654     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
655 	return NULL;
656 
657     retval = vim_strsave(tv_get_string(&rettv));
658     clear_tv(&rettv);
659     return retval;
660 }
661 
662 /*
663  * Call Vim script function "func" and return the result as a List.
664  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
665  * have type VAR_UNKNOWN.
666  * Returns NULL when there is something wrong.
667  */
668     void *
669 call_func_retlist(
670     char_u      *func,
671     int		argc,
672     typval_T	*argv)
673 {
674     typval_T	rettv;
675 
676     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
677 	return NULL;
678 
679     if (rettv.v_type != VAR_LIST)
680     {
681 	clear_tv(&rettv);
682 	return NULL;
683     }
684 
685     return rettv.vval.v_list;
686 }
687 
688 #ifdef FEAT_FOLDING
689 /*
690  * Evaluate 'foldexpr'.  Returns the foldlevel, and any character preceding
691  * it in "*cp".  Doesn't give error messages.
692  */
693     int
694 eval_foldexpr(char_u *arg, int *cp)
695 {
696     typval_T	tv;
697     varnumber_T	retval;
698     char_u	*s;
699     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
700 								   OPT_LOCAL);
701 
702     ++emsg_off;
703     if (use_sandbox)
704 	++sandbox;
705     ++textwinlock;
706     *cp = NUL;
707     if (eval0(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
708 	retval = 0;
709     else
710     {
711 	// If the result is a number, just return the number.
712 	if (tv.v_type == VAR_NUMBER)
713 	    retval = tv.vval.v_number;
714 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
715 	    retval = 0;
716 	else
717 	{
718 	    // If the result is a string, check if there is a non-digit before
719 	    // the number.
720 	    s = tv.vval.v_string;
721 	    if (!VIM_ISDIGIT(*s) && *s != '-')
722 		*cp = *s++;
723 	    retval = atol((char *)s);
724 	}
725 	clear_tv(&tv);
726     }
727     --emsg_off;
728     if (use_sandbox)
729 	--sandbox;
730     --textwinlock;
731     clear_evalarg(&EVALARG_EVALUATE, NULL);
732 
733     return (int)retval;
734 }
735 #endif
736 
737 /*
738  * Get an lval: variable, Dict item or List item that can be assigned a value
739  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
740  * "name.key", "name.key[expr]" etc.
741  * Indexing only works if "name" is an existing List or Dictionary.
742  * "name" points to the start of the name.
743  * If "rettv" is not NULL it points to the value to be assigned.
744  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
745  * wrong; must end in space or cmd separator.
746  *
747  * flags:
748  *  GLV_QUIET:       do not give error messages
749  *  GLV_READ_ONLY:   will not change the variable
750  *  GLV_NO_AUTOLOAD: do not use script autoloading
751  *
752  * Returns a pointer to just after the name, including indexes.
753  * When an evaluation error occurs "lp->ll_name" is NULL;
754  * Returns NULL for a parsing error.  Still need to free items in "lp"!
755  */
756     char_u *
757 get_lval(
758     char_u	*name,
759     typval_T	*rettv,
760     lval_T	*lp,
761     int		unlet,
762     int		skip,
763     int		flags,	    // GLV_ values
764     int		fne_flags)  // flags for find_name_end()
765 {
766     char_u	*p;
767     char_u	*expr_start, *expr_end;
768     int		cc;
769     dictitem_T	*v;
770     typval_T	var1;
771     typval_T	var2;
772     int		empty1 = FALSE;
773     listitem_T	*ni;
774     char_u	*key = NULL;
775     int		len;
776     hashtab_T	*ht;
777     int		quiet = flags & GLV_QUIET;
778 
779     // Clear everything in "lp".
780     CLEAR_POINTER(lp);
781 
782     if (skip)
783     {
784 	// When skipping just find the end of the name.
785 	lp->ll_name = name;
786 	lp->ll_name_end = find_name_end(name, NULL, NULL,
787 						      FNE_INCL_BR | fne_flags);
788 	return lp->ll_name_end;
789     }
790 
791     // Find the end of the name.
792     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
793     lp->ll_name_end = p;
794     if (expr_start != NULL)
795     {
796 	// Don't expand the name when we already know there is an error.
797 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
798 						    && *p != '[' && *p != '.')
799 	{
800 	    emsg(_(e_trailing));
801 	    return NULL;
802 	}
803 
804 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
805 	if (lp->ll_exp_name == NULL)
806 	{
807 	    // Report an invalid expression in braces, unless the
808 	    // expression evaluation has been cancelled due to an
809 	    // aborting error, an interrupt, or an exception.
810 	    if (!aborting() && !quiet)
811 	    {
812 		emsg_severe = TRUE;
813 		semsg(_(e_invarg2), name);
814 		return NULL;
815 	    }
816 	}
817 	lp->ll_name = lp->ll_exp_name;
818     }
819     else
820     {
821 	lp->ll_name = name;
822 
823 	if (current_sctx.sc_version == SCRIPT_VERSION_VIM9 && *p == ':')
824 	{
825 	    scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);
826 	    char_u	 *tp = skipwhite(p + 1);
827 
828 	    // parse the type after the name
829 	    lp->ll_type = parse_type(&tp, &si->sn_type_list);
830 	    lp->ll_name_end = tp;
831 	}
832     }
833 
834     // Without [idx] or .key we are done.
835     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
836 	return p;
837 
838     cc = *p;
839     *p = NUL;
840     // Only pass &ht when we would write to the variable, it prevents autoload
841     // as well.
842     v = find_var(lp->ll_name, (flags & GLV_READ_ONLY) ? NULL : &ht,
843 						      flags & GLV_NO_AUTOLOAD);
844     if (v == NULL && !quiet)
845 	semsg(_(e_undefvar), lp->ll_name);
846     *p = cc;
847     if (v == NULL)
848 	return NULL;
849 
850     /*
851      * Loop until no more [idx] or .key is following.
852      */
853     lp->ll_tv = &v->di_tv;
854     var1.v_type = VAR_UNKNOWN;
855     var2.v_type = VAR_UNKNOWN;
856     while (*p == '[' || (*p == '.' && lp->ll_tv->v_type == VAR_DICT))
857     {
858 	if (!(lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list != NULL)
859 		&& !(lp->ll_tv->v_type == VAR_DICT
860 					   && lp->ll_tv->vval.v_dict != NULL)
861 		&& !(lp->ll_tv->v_type == VAR_BLOB
862 					   && lp->ll_tv->vval.v_blob != NULL))
863 	{
864 	    if (!quiet)
865 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
866 	    return NULL;
867 	}
868 	if (lp->ll_range)
869 	{
870 	    if (!quiet)
871 		emsg(_("E708: [:] must come last"));
872 	    return NULL;
873 	}
874 
875 	len = -1;
876 	if (*p == '.')
877 	{
878 	    key = p + 1;
879 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
880 		;
881 	    if (len == 0)
882 	    {
883 		if (!quiet)
884 		    emsg(_(e_emptykey));
885 		return NULL;
886 	    }
887 	    p = key + len;
888 	}
889 	else
890 	{
891 	    // Get the index [expr] or the first index [expr: ].
892 	    p = skipwhite(p + 1);
893 	    if (*p == ':')
894 		empty1 = TRUE;
895 	    else
896 	    {
897 		empty1 = FALSE;
898 		if (eval1(&p, &var1, &EVALARG_EVALUATE) == FAIL)  // recursive!
899 		    return NULL;
900 		if (tv_get_string_chk(&var1) == NULL)
901 		{
902 		    // not a number or string
903 		    clear_tv(&var1);
904 		    return NULL;
905 		}
906 	    }
907 
908 	    // Optionally get the second index [ :expr].
909 	    if (*p == ':')
910 	    {
911 		if (lp->ll_tv->v_type == VAR_DICT)
912 		{
913 		    if (!quiet)
914 			emsg(_(e_dictrange));
915 		    clear_tv(&var1);
916 		    return NULL;
917 		}
918 		if (rettv != NULL
919 			&& !(rettv->v_type == VAR_LIST
920 						 && rettv->vval.v_list != NULL)
921 			&& !(rettv->v_type == VAR_BLOB
922 						&& rettv->vval.v_blob != NULL))
923 		{
924 		    if (!quiet)
925 			emsg(_("E709: [:] requires a List or Blob value"));
926 		    clear_tv(&var1);
927 		    return NULL;
928 		}
929 		p = skipwhite(p + 1);
930 		if (*p == ']')
931 		    lp->ll_empty2 = TRUE;
932 		else
933 		{
934 		    lp->ll_empty2 = FALSE;
935 		    // recursive!
936 		    if (eval1(&p, &var2, &EVALARG_EVALUATE) == FAIL)
937 		    {
938 			clear_tv(&var1);
939 			return NULL;
940 		    }
941 		    if (tv_get_string_chk(&var2) == NULL)
942 		    {
943 			// not a number or string
944 			clear_tv(&var1);
945 			clear_tv(&var2);
946 			return NULL;
947 		    }
948 		}
949 		lp->ll_range = TRUE;
950 	    }
951 	    else
952 		lp->ll_range = FALSE;
953 
954 	    if (*p != ']')
955 	    {
956 		if (!quiet)
957 		    emsg(_(e_missbrac));
958 		clear_tv(&var1);
959 		clear_tv(&var2);
960 		return NULL;
961 	    }
962 
963 	    // Skip to past ']'.
964 	    ++p;
965 	}
966 
967 	if (lp->ll_tv->v_type == VAR_DICT)
968 	{
969 	    if (len == -1)
970 	    {
971 		// "[key]": get key from "var1"
972 		key = tv_get_string_chk(&var1);	// is number or string
973 		if (key == NULL)
974 		{
975 		    clear_tv(&var1);
976 		    return NULL;
977 		}
978 	    }
979 	    lp->ll_list = NULL;
980 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
981 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
982 
983 	    // When assigning to a scope dictionary check that a function and
984 	    // variable name is valid (only variable name unless it is l: or
985 	    // g: dictionary). Disallow overwriting a builtin function.
986 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
987 	    {
988 		int prevval;
989 		int wrong;
990 
991 		if (len != -1)
992 		{
993 		    prevval = key[len];
994 		    key[len] = NUL;
995 		}
996 		else
997 		    prevval = 0; // avoid compiler warning
998 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
999 			       && rettv->v_type == VAR_FUNC
1000 			       && var_check_func_name(key, lp->ll_di == NULL))
1001 			|| !valid_varname(key);
1002 		if (len != -1)
1003 		    key[len] = prevval;
1004 		if (wrong)
1005 		{
1006 		    clear_tv(&var1);
1007 		    return NULL;
1008 		}
1009 	    }
1010 
1011 	    if (lp->ll_di == NULL)
1012 	    {
1013 		// Can't add "v:" or "a:" variable.
1014 		if (lp->ll_dict == get_vimvar_dict()
1015 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
1016 		{
1017 		    semsg(_(e_illvar), name);
1018 		    clear_tv(&var1);
1019 		    return NULL;
1020 		}
1021 
1022 		// Key does not exist in dict: may need to add it.
1023 		if (*p == '[' || *p == '.' || unlet)
1024 		{
1025 		    if (!quiet)
1026 			semsg(_(e_dictkey), key);
1027 		    clear_tv(&var1);
1028 		    return NULL;
1029 		}
1030 		if (len == -1)
1031 		    lp->ll_newkey = vim_strsave(key);
1032 		else
1033 		    lp->ll_newkey = vim_strnsave(key, len);
1034 		clear_tv(&var1);
1035 		if (lp->ll_newkey == NULL)
1036 		    p = NULL;
1037 		break;
1038 	    }
1039 	    // existing variable, need to check if it can be changed
1040 	    else if ((flags & GLV_READ_ONLY) == 0
1041 			     && var_check_ro(lp->ll_di->di_flags, name, FALSE))
1042 	    {
1043 		clear_tv(&var1);
1044 		return NULL;
1045 	    }
1046 
1047 	    clear_tv(&var1);
1048 	    lp->ll_tv = &lp->ll_di->di_tv;
1049 	}
1050 	else if (lp->ll_tv->v_type == VAR_BLOB)
1051 	{
1052 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
1053 
1054 	    /*
1055 	     * Get the number and item for the only or first index of the List.
1056 	     */
1057 	    if (empty1)
1058 		lp->ll_n1 = 0;
1059 	    else
1060 		// is number or string
1061 		lp->ll_n1 = (long)tv_get_number(&var1);
1062 	    clear_tv(&var1);
1063 
1064 	    if (lp->ll_n1 < 0
1065 		    || lp->ll_n1 > bloblen
1066 		    || (lp->ll_range && lp->ll_n1 == bloblen))
1067 	    {
1068 		if (!quiet)
1069 		    semsg(_(e_blobidx), lp->ll_n1);
1070 		clear_tv(&var2);
1071 		return NULL;
1072 	    }
1073 	    if (lp->ll_range && !lp->ll_empty2)
1074 	    {
1075 		lp->ll_n2 = (long)tv_get_number(&var2);
1076 		clear_tv(&var2);
1077 		if (lp->ll_n2 < 0
1078 			|| lp->ll_n2 >= bloblen
1079 			|| lp->ll_n2 < lp->ll_n1)
1080 		{
1081 		    if (!quiet)
1082 			semsg(_(e_blobidx), lp->ll_n2);
1083 		    return NULL;
1084 		}
1085 	    }
1086 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
1087 	    lp->ll_tv = NULL;
1088 	    break;
1089 	}
1090 	else
1091 	{
1092 	    /*
1093 	     * Get the number and item for the only or first index of the List.
1094 	     */
1095 	    if (empty1)
1096 		lp->ll_n1 = 0;
1097 	    else
1098 		// is number or string
1099 		lp->ll_n1 = (long)tv_get_number(&var1);
1100 	    clear_tv(&var1);
1101 
1102 	    lp->ll_dict = NULL;
1103 	    lp->ll_list = lp->ll_tv->vval.v_list;
1104 	    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
1105 	    if (lp->ll_li == NULL)
1106 	    {
1107 		if (lp->ll_n1 < 0)
1108 		{
1109 		    lp->ll_n1 = 0;
1110 		    lp->ll_li = list_find(lp->ll_list, lp->ll_n1);
1111 		}
1112 	    }
1113 	    if (lp->ll_li == NULL)
1114 	    {
1115 		clear_tv(&var2);
1116 		if (!quiet)
1117 		    semsg(_(e_listidx), lp->ll_n1);
1118 		return NULL;
1119 	    }
1120 
1121 	    /*
1122 	     * May need to find the item or absolute index for the second
1123 	     * index of a range.
1124 	     * When no index given: "lp->ll_empty2" is TRUE.
1125 	     * Otherwise "lp->ll_n2" is set to the second index.
1126 	     */
1127 	    if (lp->ll_range && !lp->ll_empty2)
1128 	    {
1129 		lp->ll_n2 = (long)tv_get_number(&var2);
1130 						    // is number or string
1131 		clear_tv(&var2);
1132 		if (lp->ll_n2 < 0)
1133 		{
1134 		    ni = list_find(lp->ll_list, lp->ll_n2);
1135 		    if (ni == NULL)
1136 		    {
1137 			if (!quiet)
1138 			    semsg(_(e_listidx), lp->ll_n2);
1139 			return NULL;
1140 		    }
1141 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
1142 		}
1143 
1144 		// Check that lp->ll_n2 isn't before lp->ll_n1.
1145 		if (lp->ll_n1 < 0)
1146 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
1147 		if (lp->ll_n2 < lp->ll_n1)
1148 		{
1149 		    if (!quiet)
1150 			semsg(_(e_listidx), lp->ll_n2);
1151 		    return NULL;
1152 		}
1153 	    }
1154 
1155 	    lp->ll_tv = &lp->ll_li->li_tv;
1156 	}
1157     }
1158 
1159     clear_tv(&var1);
1160     lp->ll_name_end = p;
1161     return p;
1162 }
1163 
1164 /*
1165  * Clear lval "lp" that was filled by get_lval().
1166  */
1167     void
1168 clear_lval(lval_T *lp)
1169 {
1170     vim_free(lp->ll_exp_name);
1171     vim_free(lp->ll_newkey);
1172 }
1173 
1174 /*
1175  * Set a variable that was parsed by get_lval() to "rettv".
1176  * "endp" points to just after the parsed name.
1177  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
1178  * "%" for "%=", "." for ".=" or "=" for "=".
1179  */
1180     void
1181 set_var_lval(
1182     lval_T	*lp,
1183     char_u	*endp,
1184     typval_T	*rettv,
1185     int		copy,
1186     int		flags,    // LET_IS_CONST and/or LET_NO_COMMAND
1187     char_u	*op)
1188 {
1189     int		cc;
1190     listitem_T	*ri;
1191     dictitem_T	*di;
1192 
1193     if (lp->ll_tv == NULL)
1194     {
1195 	cc = *endp;
1196 	*endp = NUL;
1197 	if (lp->ll_blob != NULL)
1198 	{
1199 	    int	    error = FALSE, val;
1200 
1201 	    if (op != NULL && *op != '=')
1202 	    {
1203 		semsg(_(e_letwrong), op);
1204 		return;
1205 	    }
1206 
1207 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
1208 	    {
1209 		int	il, ir;
1210 
1211 		if (lp->ll_empty2)
1212 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
1213 
1214 		if (lp->ll_n2 - lp->ll_n1 + 1 != blob_len(rettv->vval.v_blob))
1215 		{
1216 		    emsg(_("E972: Blob value does not have the right number of bytes"));
1217 		    return;
1218 		}
1219 		if (lp->ll_empty2)
1220 		    lp->ll_n2 = blob_len(lp->ll_blob);
1221 
1222 		ir = 0;
1223 		for (il = lp->ll_n1; il <= lp->ll_n2; il++)
1224 		    blob_set(lp->ll_blob, il,
1225 			    blob_get(rettv->vval.v_blob, ir++));
1226 	    }
1227 	    else
1228 	    {
1229 		val = (int)tv_get_number_chk(rettv, &error);
1230 		if (!error)
1231 		{
1232 		    garray_T *gap = &lp->ll_blob->bv_ga;
1233 
1234 		    // Allow for appending a byte.  Setting a byte beyond
1235 		    // the end is an error otherwise.
1236 		    if (lp->ll_n1 < gap->ga_len
1237 			    || (lp->ll_n1 == gap->ga_len
1238 				&& ga_grow(&lp->ll_blob->bv_ga, 1) == OK))
1239 		    {
1240 			blob_set(lp->ll_blob, lp->ll_n1, val);
1241 			if (lp->ll_n1 == gap->ga_len)
1242 			    ++gap->ga_len;
1243 		    }
1244 		    // error for invalid range was already given in get_lval()
1245 		}
1246 	    }
1247 	}
1248 	else if (op != NULL && *op != '=')
1249 	{
1250 	    typval_T tv;
1251 
1252 	    if (flags & LET_IS_CONST)
1253 	    {
1254 		emsg(_(e_cannot_mod));
1255 		*endp = cc;
1256 		return;
1257 	    }
1258 
1259 	    // handle +=, -=, *=, /=, %= and .=
1260 	    di = NULL;
1261 	    if (eval_variable(lp->ll_name, (int)STRLEN(lp->ll_name),
1262 					     &tv, &di, TRUE, FALSE) == OK)
1263 	    {
1264 		if ((di == NULL
1265 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
1266 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
1267 			&& tv_op(&tv, rettv, op) == OK)
1268 		    set_var(lp->ll_name, &tv, FALSE);
1269 		clear_tv(&tv);
1270 	    }
1271 	}
1272 	else
1273 	    set_var_const(lp->ll_name, lp->ll_type, rettv, copy, flags);
1274 	*endp = cc;
1275     }
1276     else if (var_check_lock(lp->ll_newkey == NULL
1277 		? lp->ll_tv->v_lock
1278 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
1279 	;
1280     else if (lp->ll_range)
1281     {
1282 	listitem_T *ll_li = lp->ll_li;
1283 	int	    ll_n1 = lp->ll_n1;
1284 
1285 	if (flags & LET_IS_CONST)
1286 	{
1287 	    emsg(_("E996: Cannot lock a range"));
1288 	    return;
1289 	}
1290 
1291 	/*
1292 	 * Check whether any of the list items is locked
1293 	 */
1294 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
1295 	{
1296 	    if (var_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
1297 		return;
1298 	    ri = ri->li_next;
1299 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
1300 		break;
1301 	    ll_li = ll_li->li_next;
1302 	    ++ll_n1;
1303 	}
1304 
1305 	/*
1306 	 * Assign the List values to the list items.
1307 	 */
1308 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
1309 	{
1310 	    if (op != NULL && *op != '=')
1311 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
1312 	    else
1313 	    {
1314 		clear_tv(&lp->ll_li->li_tv);
1315 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
1316 	    }
1317 	    ri = ri->li_next;
1318 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
1319 		break;
1320 	    if (lp->ll_li->li_next == NULL)
1321 	    {
1322 		// Need to add an empty item.
1323 		if (list_append_number(lp->ll_list, 0) == FAIL)
1324 		{
1325 		    ri = NULL;
1326 		    break;
1327 		}
1328 	    }
1329 	    lp->ll_li = lp->ll_li->li_next;
1330 	    ++lp->ll_n1;
1331 	}
1332 	if (ri != NULL)
1333 	    emsg(_("E710: List value has more items than target"));
1334 	else if (lp->ll_empty2
1335 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
1336 		: lp->ll_n1 != lp->ll_n2)
1337 	    emsg(_("E711: List value has not enough items"));
1338     }
1339     else
1340     {
1341 	/*
1342 	 * Assign to a List or Dictionary item.
1343 	 */
1344 	if (flags & LET_IS_CONST)
1345 	{
1346 	    emsg(_("E996: Cannot lock a list or dict"));
1347 	    return;
1348 	}
1349 	if (lp->ll_newkey != NULL)
1350 	{
1351 	    if (op != NULL && *op != '=')
1352 	    {
1353 		semsg(_(e_letwrong), op);
1354 		return;
1355 	    }
1356 
1357 	    // Need to add an item to the Dictionary.
1358 	    di = dictitem_alloc(lp->ll_newkey);
1359 	    if (di == NULL)
1360 		return;
1361 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
1362 	    {
1363 		vim_free(di);
1364 		return;
1365 	    }
1366 	    lp->ll_tv = &di->di_tv;
1367 	}
1368 	else if (op != NULL && *op != '=')
1369 	{
1370 	    tv_op(lp->ll_tv, rettv, op);
1371 	    return;
1372 	}
1373 	else
1374 	    clear_tv(lp->ll_tv);
1375 
1376 	/*
1377 	 * Assign the value to the variable or list item.
1378 	 */
1379 	if (copy)
1380 	    copy_tv(rettv, lp->ll_tv);
1381 	else
1382 	{
1383 	    *lp->ll_tv = *rettv;
1384 	    lp->ll_tv->v_lock = 0;
1385 	    init_tv(rettv);
1386 	}
1387     }
1388 }
1389 
1390 /*
1391  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
1392  * and "tv1 .= tv2"
1393  * Returns OK or FAIL.
1394  */
1395     static int
1396 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
1397 {
1398     varnumber_T	n;
1399     char_u	numbuf[NUMBUFLEN];
1400     char_u	*s;
1401 
1402     // Can't do anything with a Funcref, Dict, v:true on the right.
1403     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
1404 		      && tv2->v_type != VAR_BOOL && tv2->v_type != VAR_SPECIAL)
1405     {
1406 	switch (tv1->v_type)
1407 	{
1408 	    case VAR_UNKNOWN:
1409 	    case VAR_ANY:
1410 	    case VAR_VOID:
1411 	    case VAR_DICT:
1412 	    case VAR_FUNC:
1413 	    case VAR_PARTIAL:
1414 	    case VAR_BOOL:
1415 	    case VAR_SPECIAL:
1416 	    case VAR_JOB:
1417 	    case VAR_CHANNEL:
1418 		break;
1419 
1420 	    case VAR_BLOB:
1421 		if (*op != '+' || tv2->v_type != VAR_BLOB)
1422 		    break;
1423 		// BLOB += BLOB
1424 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
1425 		{
1426 		    blob_T  *b1 = tv1->vval.v_blob;
1427 		    blob_T  *b2 = tv2->vval.v_blob;
1428 		    int	i, len = blob_len(b2);
1429 		    for (i = 0; i < len; i++)
1430 			ga_append(&b1->bv_ga, blob_get(b2, i));
1431 		}
1432 		return OK;
1433 
1434 	    case VAR_LIST:
1435 		if (*op != '+' || tv2->v_type != VAR_LIST)
1436 		    break;
1437 		// List += List
1438 		if (tv1->vval.v_list != NULL && tv2->vval.v_list != NULL)
1439 		    list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
1440 		return OK;
1441 
1442 	    case VAR_NUMBER:
1443 	    case VAR_STRING:
1444 		if (tv2->v_type == VAR_LIST)
1445 		    break;
1446 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
1447 		{
1448 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
1449 		    n = tv_get_number(tv1);
1450 #ifdef FEAT_FLOAT
1451 		    if (tv2->v_type == VAR_FLOAT)
1452 		    {
1453 			float_T f = n;
1454 
1455 			if (*op == '%')
1456 			    break;
1457 			switch (*op)
1458 			{
1459 			    case '+': f += tv2->vval.v_float; break;
1460 			    case '-': f -= tv2->vval.v_float; break;
1461 			    case '*': f *= tv2->vval.v_float; break;
1462 			    case '/': f /= tv2->vval.v_float; break;
1463 			}
1464 			clear_tv(tv1);
1465 			tv1->v_type = VAR_FLOAT;
1466 			tv1->vval.v_float = f;
1467 		    }
1468 		    else
1469 #endif
1470 		    {
1471 			switch (*op)
1472 			{
1473 			    case '+': n += tv_get_number(tv2); break;
1474 			    case '-': n -= tv_get_number(tv2); break;
1475 			    case '*': n *= tv_get_number(tv2); break;
1476 			    case '/': n = num_divide(n, tv_get_number(tv2)); break;
1477 			    case '%': n = num_modulus(n, tv_get_number(tv2)); break;
1478 			}
1479 			clear_tv(tv1);
1480 			tv1->v_type = VAR_NUMBER;
1481 			tv1->vval.v_number = n;
1482 		    }
1483 		}
1484 		else
1485 		{
1486 		    if (tv2->v_type == VAR_FLOAT)
1487 			break;
1488 
1489 		    // str .= str
1490 		    s = tv_get_string(tv1);
1491 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
1492 		    clear_tv(tv1);
1493 		    tv1->v_type = VAR_STRING;
1494 		    tv1->vval.v_string = s;
1495 		}
1496 		return OK;
1497 
1498 	    case VAR_FLOAT:
1499 #ifdef FEAT_FLOAT
1500 		{
1501 		    float_T f;
1502 
1503 		    if (*op == '%' || *op == '.'
1504 				   || (tv2->v_type != VAR_FLOAT
1505 				    && tv2->v_type != VAR_NUMBER
1506 				    && tv2->v_type != VAR_STRING))
1507 			break;
1508 		    if (tv2->v_type == VAR_FLOAT)
1509 			f = tv2->vval.v_float;
1510 		    else
1511 			f = tv_get_number(tv2);
1512 		    switch (*op)
1513 		    {
1514 			case '+': tv1->vval.v_float += f; break;
1515 			case '-': tv1->vval.v_float -= f; break;
1516 			case '*': tv1->vval.v_float *= f; break;
1517 			case '/': tv1->vval.v_float /= f; break;
1518 		    }
1519 		}
1520 #endif
1521 		return OK;
1522 	}
1523     }
1524 
1525     semsg(_(e_letwrong), op);
1526     return FAIL;
1527 }
1528 
1529 /*
1530  * Evaluate the expression used in a ":for var in expr" command.
1531  * "arg" points to "var".
1532  * Set "*errp" to TRUE for an error, FALSE otherwise;
1533  * Return a pointer that holds the info.  Null when there is an error.
1534  */
1535     void *
1536 eval_for_line(
1537     char_u	*arg,
1538     int		*errp,
1539     exarg_T	*eap,
1540     evalarg_T	*evalarg)
1541 {
1542     forinfo_T	*fi;
1543     char_u	*expr;
1544     typval_T	tv;
1545     list_T	*l;
1546     int		skip = !(evalarg->eval_flags & EVAL_EVALUATE);
1547 
1548     *errp = TRUE;	// default: there is an error
1549 
1550     fi = ALLOC_CLEAR_ONE(forinfo_T);
1551     if (fi == NULL)
1552 	return NULL;
1553 
1554     expr = skip_var_list(arg, TRUE, &fi->fi_varcount, &fi->fi_semicolon, FALSE);
1555     if (expr == NULL)
1556 	return fi;
1557 
1558     expr = skipwhite_and_linebreak(expr, evalarg);
1559     if (expr[0] != 'i' || expr[1] != 'n'
1560 				  || !(expr[2] == NUL || VIM_ISWHITE(expr[2])))
1561     {
1562 	emsg(_(e_missing_in));
1563 	return fi;
1564     }
1565 
1566     if (skip)
1567 	++emsg_skip;
1568     expr = skipwhite_and_linebreak(expr + 2, evalarg);
1569     if (eval0(expr, &tv, eap, evalarg) == OK)
1570     {
1571 	*errp = FALSE;
1572 	if (!skip)
1573 	{
1574 	    if (tv.v_type == VAR_LIST)
1575 	    {
1576 		l = tv.vval.v_list;
1577 		if (l == NULL)
1578 		{
1579 		    // a null list is like an empty list: do nothing
1580 		    clear_tv(&tv);
1581 		}
1582 		else
1583 		{
1584 		    // Need a real list here.
1585 		    CHECK_LIST_MATERIALIZE(l);
1586 
1587 		    // No need to increment the refcount, it's already set for
1588 		    // the list being used in "tv".
1589 		    fi->fi_list = l;
1590 		    list_add_watch(l, &fi->fi_lw);
1591 		    fi->fi_lw.lw_item = l->lv_first;
1592 		}
1593 	    }
1594 	    else if (tv.v_type == VAR_BLOB)
1595 	    {
1596 		fi->fi_bi = 0;
1597 		if (tv.vval.v_blob != NULL)
1598 		{
1599 		    typval_T btv;
1600 
1601 		    // Make a copy, so that the iteration still works when the
1602 		    // blob is changed.
1603 		    blob_copy(tv.vval.v_blob, &btv);
1604 		    fi->fi_blob = btv.vval.v_blob;
1605 		}
1606 		clear_tv(&tv);
1607 	    }
1608 	    else
1609 	    {
1610 		emsg(_(e_listreq));
1611 		clear_tv(&tv);
1612 	    }
1613 	}
1614     }
1615     if (skip)
1616 	--emsg_skip;
1617     fi->fi_break_count = evalarg->eval_break_count;
1618 
1619     return fi;
1620 }
1621 
1622 /*
1623  * Used when looping over a :for line, skip the "in expr" part.
1624  */
1625     void
1626 skip_for_lines(void *fi_void, evalarg_T *evalarg)
1627 {
1628     forinfo_T	*fi = (forinfo_T *)fi_void;
1629     int		i;
1630 
1631     for (i = 0; i < fi->fi_break_count; ++i)
1632 	eval_next_line(evalarg);
1633 }
1634 
1635 /*
1636  * Use the first item in a ":for" list.  Advance to the next.
1637  * Assign the values to the variable (list).  "arg" points to the first one.
1638  * Return TRUE when a valid item was found, FALSE when at end of list or
1639  * something wrong.
1640  */
1641     int
1642 next_for_item(void *fi_void, char_u *arg)
1643 {
1644     forinfo_T	*fi = (forinfo_T *)fi_void;
1645     int		result;
1646     int		flag = current_sctx.sc_version == SCRIPT_VERSION_VIM9 ?
1647 							LET_NO_COMMAND : 0;
1648     listitem_T	*item;
1649 
1650     if (fi->fi_blob != NULL)
1651     {
1652 	typval_T	tv;
1653 
1654 	if (fi->fi_bi >= blob_len(fi->fi_blob))
1655 	    return FALSE;
1656 	tv.v_type = VAR_NUMBER;
1657 	tv.v_lock = VAR_FIXED;
1658 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
1659 	++fi->fi_bi;
1660 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1661 				       fi->fi_varcount, flag, NULL) == OK;
1662     }
1663 
1664     item = fi->fi_lw.lw_item;
1665     if (item == NULL)
1666 	result = FALSE;
1667     else
1668     {
1669 	fi->fi_lw.lw_item = item->li_next;
1670 	result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
1671 				      fi->fi_varcount, flag, NULL) == OK);
1672     }
1673     return result;
1674 }
1675 
1676 /*
1677  * Free the structure used to store info used by ":for".
1678  */
1679     void
1680 free_for_info(void *fi_void)
1681 {
1682     forinfo_T    *fi = (forinfo_T *)fi_void;
1683 
1684     if (fi != NULL && fi->fi_list != NULL)
1685     {
1686 	list_rem_watch(fi->fi_list, &fi->fi_lw);
1687 	list_unref(fi->fi_list);
1688     }
1689     if (fi != NULL && fi->fi_blob != NULL)
1690 	blob_unref(fi->fi_blob);
1691     vim_free(fi);
1692 }
1693 
1694     void
1695 set_context_for_expression(
1696     expand_T	*xp,
1697     char_u	*arg,
1698     cmdidx_T	cmdidx)
1699 {
1700     int		got_eq = FALSE;
1701     int		c;
1702     char_u	*p;
1703 
1704     if (cmdidx == CMD_let || cmdidx == CMD_const)
1705     {
1706 	xp->xp_context = EXPAND_USER_VARS;
1707 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
1708 	{
1709 	    // ":let var1 var2 ...": find last space.
1710 	    for (p = arg + STRLEN(arg); p >= arg; )
1711 	    {
1712 		xp->xp_pattern = p;
1713 		MB_PTR_BACK(arg, p);
1714 		if (VIM_ISWHITE(*p))
1715 		    break;
1716 	    }
1717 	    return;
1718 	}
1719     }
1720     else
1721 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
1722 							  : EXPAND_EXPRESSION;
1723     while ((xp->xp_pattern = vim_strpbrk(arg,
1724 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
1725     {
1726 	c = *xp->xp_pattern;
1727 	if (c == '&')
1728 	{
1729 	    c = xp->xp_pattern[1];
1730 	    if (c == '&')
1731 	    {
1732 		++xp->xp_pattern;
1733 		xp->xp_context = cmdidx != CMD_let || got_eq
1734 					 ? EXPAND_EXPRESSION : EXPAND_NOTHING;
1735 	    }
1736 	    else if (c != ' ')
1737 	    {
1738 		xp->xp_context = EXPAND_SETTINGS;
1739 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
1740 		    xp->xp_pattern += 2;
1741 
1742 	    }
1743 	}
1744 	else if (c == '$')
1745 	{
1746 	    // environment variable
1747 	    xp->xp_context = EXPAND_ENV_VARS;
1748 	}
1749 	else if (c == '=')
1750 	{
1751 	    got_eq = TRUE;
1752 	    xp->xp_context = EXPAND_EXPRESSION;
1753 	}
1754 	else if (c == '#'
1755 		&& xp->xp_context == EXPAND_EXPRESSION)
1756 	{
1757 	    // Autoload function/variable contains '#'.
1758 	    break;
1759 	}
1760 	else if ((c == '<' || c == '#')
1761 		&& xp->xp_context == EXPAND_FUNCTIONS
1762 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
1763 	{
1764 	    // Function name can start with "<SNR>" and contain '#'.
1765 	    break;
1766 	}
1767 	else if (cmdidx != CMD_let || got_eq)
1768 	{
1769 	    if (c == '"')	    // string
1770 	    {
1771 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
1772 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
1773 			++xp->xp_pattern;
1774 		xp->xp_context = EXPAND_NOTHING;
1775 	    }
1776 	    else if (c == '\'')	    // literal string
1777 	    {
1778 		// Trick: '' is like stopping and starting a literal string.
1779 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
1780 		    /* skip */ ;
1781 		xp->xp_context = EXPAND_NOTHING;
1782 	    }
1783 	    else if (c == '|')
1784 	    {
1785 		if (xp->xp_pattern[1] == '|')
1786 		{
1787 		    ++xp->xp_pattern;
1788 		    xp->xp_context = EXPAND_EXPRESSION;
1789 		}
1790 		else
1791 		    xp->xp_context = EXPAND_COMMANDS;
1792 	    }
1793 	    else
1794 		xp->xp_context = EXPAND_EXPRESSION;
1795 	}
1796 	else
1797 	    // Doesn't look like something valid, expand as an expression
1798 	    // anyway.
1799 	    xp->xp_context = EXPAND_EXPRESSION;
1800 	arg = xp->xp_pattern;
1801 	if (*arg != NUL)
1802 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
1803 		/* skip */ ;
1804     }
1805     xp->xp_pattern = arg;
1806 }
1807 
1808 /*
1809  * Return TRUE if "pat" matches "text".
1810  * Does not use 'cpo' and always uses 'magic'.
1811  */
1812     int
1813 pattern_match(char_u *pat, char_u *text, int ic)
1814 {
1815     int		matches = FALSE;
1816     char_u	*save_cpo;
1817     regmatch_T	regmatch;
1818 
1819     // avoid 'l' flag in 'cpoptions'
1820     save_cpo = p_cpo;
1821     p_cpo = (char_u *)"";
1822     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1823     if (regmatch.regprog != NULL)
1824     {
1825 	regmatch.rm_ic = ic;
1826 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
1827 	vim_regfree(regmatch.regprog);
1828     }
1829     p_cpo = save_cpo;
1830     return matches;
1831 }
1832 
1833 /*
1834  * Handle a name followed by "(".  Both for just "name(arg)" and for
1835  * "expr->name(arg)".
1836  * Returns OK or FAIL.
1837  */
1838     static int
1839 eval_func(
1840 	char_u	    **arg,	// points to "(", will be advanced
1841 	evalarg_T   *evalarg,
1842 	char_u	    *name,
1843 	int	    name_len,
1844 	typval_T    *rettv,
1845 	int	    flags,
1846 	typval_T    *basetv)	// "expr" for "expr->name(arg)"
1847 {
1848     int		evaluate = flags & EVAL_EVALUATE;
1849     char_u	*s = name;
1850     int		len = name_len;
1851     partial_T	*partial;
1852     int		ret = OK;
1853 
1854     if (!evaluate)
1855 	check_vars(s, len);
1856 
1857     // If "s" is the name of a variable of type VAR_FUNC
1858     // use its contents.
1859     s = deref_func_name(s, &len, &partial, !evaluate);
1860 
1861     // Need to make a copy, in case evaluating the arguments makes
1862     // the name invalid.
1863     s = vim_strsave(s);
1864     if (s == NULL || (flags & EVAL_CONSTANT))
1865 	ret = FAIL;
1866     else
1867     {
1868 	funcexe_T funcexe;
1869 
1870 	// Invoke the function.
1871 	CLEAR_FIELD(funcexe);
1872 	funcexe.firstline = curwin->w_cursor.lnum;
1873 	funcexe.lastline = curwin->w_cursor.lnum;
1874 	funcexe.evaluate = evaluate;
1875 	funcexe.partial = partial;
1876 	funcexe.basetv = basetv;
1877 	ret = get_func_tv(s, len, rettv, arg, evalarg, &funcexe);
1878     }
1879     vim_free(s);
1880 
1881     // If evaluate is FALSE rettv->v_type was not set in
1882     // get_func_tv, but it's needed in handle_subscript() to parse
1883     // what follows. So set it here.
1884     if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
1885     {
1886 	rettv->vval.v_string = NULL;
1887 	rettv->v_type = VAR_FUNC;
1888     }
1889 
1890     // Stop the expression evaluation when immediately
1891     // aborting on error, or when an interrupt occurred or
1892     // an exception was thrown but not caught.
1893     if (evaluate && aborting())
1894     {
1895 	if (ret == OK)
1896 	    clear_tv(rettv);
1897 	ret = FAIL;
1898     }
1899     return ret;
1900 }
1901 
1902 /*
1903  * If inside Vim9 script, "arg" points to the end of a line (ignoring a #
1904  * comment) and there is a next line, return the next line (skipping blanks)
1905  * and set "getnext".
1906  * Otherwise just return "arg" unmodified and set "getnext" to FALSE.
1907  * "arg" must point somewhere inside a line, not at the start.
1908  */
1909     char_u *
1910 eval_next_non_blank(char_u *arg, evalarg_T *evalarg, int *getnext)
1911 {
1912     *getnext = FALSE;
1913     if (current_sctx.sc_version == SCRIPT_VERSION_VIM9
1914 	    && evalarg != NULL
1915 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL)
1916 	    && (*arg == NUL || (VIM_ISWHITE(arg[-1])
1917 					     && *arg == '#' && arg[1] != '{')))
1918     {
1919 	char_u *p;
1920 
1921 	if (evalarg->eval_cookie != NULL)
1922 	    p = getline_peek(evalarg->eval_getline, evalarg->eval_cookie);
1923 	else
1924 	    p = peek_next_line_from_context(evalarg->eval_cctx);
1925 
1926 	if (p != NULL)
1927 	{
1928 	    *getnext = TRUE;
1929 	    return skipwhite(p);
1930 	}
1931     }
1932     return arg;
1933 }
1934 
1935 /*
1936  * To be called after eval_next_non_blank() sets "getnext" to TRUE.
1937  */
1938     char_u *
1939 eval_next_line(evalarg_T *evalarg)
1940 {
1941     garray_T	*gap = &evalarg->eval_ga;
1942     char_u	*line;
1943 
1944     if (evalarg->eval_cookie != NULL)
1945 	line = evalarg->eval_getline(0, evalarg->eval_cookie, 0, TRUE);
1946     else
1947 	line = next_line_from_context(evalarg->eval_cctx, TRUE);
1948     ++evalarg->eval_break_count;
1949     if (gap->ga_itemsize > 0 && ga_grow(gap, 1) == OK)
1950     {
1951 	// Going to concatenate the lines after parsing.
1952 	((char_u **)gap->ga_data)[gap->ga_len] = line;
1953 	++gap->ga_len;
1954     }
1955     else if (evalarg->eval_cookie != NULL)
1956     {
1957 	vim_free(evalarg->eval_tofree);
1958 	evalarg->eval_tofree = line;
1959     }
1960     return skipwhite(line);
1961 }
1962 
1963 /*
1964  * Call eval_next_non_blank() and get the next line if needed.
1965  */
1966     char_u *
1967 skipwhite_and_linebreak(char_u *arg, evalarg_T *evalarg)
1968 {
1969     int	    getnext;
1970     char_u  *p = skipwhite(arg);
1971 
1972     if (evalarg == NULL)
1973 	return skipwhite(arg);
1974     eval_next_non_blank(p, evalarg, &getnext);
1975     if (getnext)
1976 	return eval_next_line(evalarg);
1977     return p;
1978 }
1979 
1980 /*
1981  * After using "evalarg" filled from "eap": free the memory.
1982  */
1983     void
1984 clear_evalarg(evalarg_T *evalarg, exarg_T *eap)
1985 {
1986     if (evalarg != NULL)
1987     {
1988 	if (evalarg->eval_tofree != NULL)
1989 	{
1990 	    if (eap != NULL)
1991 	    {
1992 		// We may need to keep the original command line, e.g. for
1993 		// ":let" it has the variable names.  But we may also need the
1994 		// new one, "nextcmd" points into it.  Keep both.
1995 		vim_free(eap->cmdline_tofree);
1996 		eap->cmdline_tofree = *eap->cmdlinep;
1997 		*eap->cmdlinep = evalarg->eval_tofree;
1998 	    }
1999 	    else
2000 		vim_free(evalarg->eval_tofree);
2001 	    evalarg->eval_tofree = NULL;
2002 	}
2003 
2004 	vim_free(evalarg->eval_tofree_lambda);
2005 	evalarg->eval_tofree_lambda = NULL;
2006     }
2007 }
2008 
2009 /*
2010  * The "evaluate" argument: When FALSE, the argument is only parsed but not
2011  * executed.  The function may return OK, but the rettv will be of type
2012  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
2013  */
2014 
2015 /*
2016  * Handle zero level expression.
2017  * This calls eval1() and handles error message and nextcmd.
2018  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
2019  * Note: "rettv.v_lock" is not set.
2020  * "evalarg" can be NULL, EVALARG_EVALUATE or a pointer.
2021  * Return OK or FAIL.
2022  */
2023     int
2024 eval0(
2025     char_u	*arg,
2026     typval_T	*rettv,
2027     exarg_T	*eap,
2028     evalarg_T	*evalarg)
2029 {
2030     int		ret;
2031     char_u	*p;
2032     int		did_emsg_before = did_emsg;
2033     int		called_emsg_before = called_emsg;
2034     int		flags = evalarg == NULL ? 0 : evalarg->eval_flags;
2035 
2036     p = skipwhite(arg);
2037     ret = eval1(&p, rettv, evalarg);
2038 
2039     if (ret == FAIL || !ends_excmd2(arg, p))
2040     {
2041 	if (ret != FAIL)
2042 	    clear_tv(rettv);
2043 	/*
2044 	 * Report the invalid expression unless the expression evaluation has
2045 	 * been cancelled due to an aborting error, an interrupt, or an
2046 	 * exception, or we already gave a more specific error.
2047 	 * Also check called_emsg for when using assert_fails().
2048 	 */
2049 	if (!aborting()
2050 		&& did_emsg == did_emsg_before
2051 		&& called_emsg == called_emsg_before
2052 		&& (flags & EVAL_CONSTANT) == 0)
2053 	    semsg(_(e_invexpr2), arg);
2054 	ret = FAIL;
2055     }
2056 
2057     if (eap != NULL)
2058 	eap->nextcmd = check_nextcmd(p);
2059 
2060     return ret;
2061 }
2062 
2063 /*
2064  * Handle top level expression:
2065  *	expr2 ? expr1 : expr1
2066  *
2067  * "arg" must point to the first non-white of the expression.
2068  * "arg" is advanced to the next non-white after the recognized expression.
2069  *
2070  * Note: "rettv.v_lock" is not set.
2071  *
2072  * Return OK or FAIL.
2073  */
2074     int
2075 eval1(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2076 {
2077     char_u  *p;
2078     int	    getnext;
2079 
2080     /*
2081      * Get the first variable.
2082      */
2083     if (eval2(arg, rettv, evalarg) == FAIL)
2084 	return FAIL;
2085 
2086     p = eval_next_non_blank(*arg, evalarg, &getnext);
2087     if (*p == '?')
2088     {
2089 	int		result;
2090 	typval_T	var2;
2091 	evalarg_T	nested_evalarg;
2092 	int		orig_flags;
2093 	int		evaluate;
2094 
2095 	if (getnext)
2096 	    *arg = eval_next_line(evalarg);
2097 
2098 	if (evalarg == NULL)
2099 	{
2100 	    CLEAR_FIELD(nested_evalarg);
2101 	    orig_flags = 0;
2102 	}
2103 	else
2104 	{
2105 	    nested_evalarg = *evalarg;
2106 	    orig_flags = evalarg->eval_flags;
2107 	}
2108 
2109 	evaluate = nested_evalarg.eval_flags & EVAL_EVALUATE;
2110 	result = FALSE;
2111 	if (evaluate)
2112 	{
2113 	    int		error = FALSE;
2114 
2115 	    if (tv_get_number_chk(rettv, &error) != 0)
2116 		result = TRUE;
2117 	    clear_tv(rettv);
2118 	    if (error)
2119 		return FAIL;
2120 	}
2121 
2122 	/*
2123 	 * Get the second variable.  Recursive!
2124 	 */
2125 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
2126 	nested_evalarg.eval_flags = result ? orig_flags
2127 						 : orig_flags & ~EVAL_EVALUATE;
2128 	if (eval1(arg, rettv, &nested_evalarg) == FAIL)
2129 	    return FAIL;
2130 
2131 	/*
2132 	 * Check for the ":".
2133 	 */
2134 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2135 	if (*p != ':')
2136 	{
2137 	    emsg(_(e_missing_colon));
2138 	    if (evaluate && result)
2139 		clear_tv(rettv);
2140 	    return FAIL;
2141 	}
2142 	if (getnext)
2143 	    *arg = eval_next_line(evalarg);
2144 
2145 	/*
2146 	 * Get the third variable.  Recursive!
2147 	 */
2148 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
2149 	nested_evalarg.eval_flags = !result ? orig_flags
2150 						 : orig_flags & ~EVAL_EVALUATE;
2151 	if (eval1(arg, &var2, &nested_evalarg) == FAIL)
2152 	{
2153 	    if (evaluate && result)
2154 		clear_tv(rettv);
2155 	    return FAIL;
2156 	}
2157 	if (evaluate && !result)
2158 	    *rettv = var2;
2159     }
2160 
2161     return OK;
2162 }
2163 
2164 /*
2165  * Handle first level expression:
2166  *	expr2 || expr2 || expr2	    logical OR
2167  *
2168  * "arg" must point to the first non-white of the expression.
2169  * "arg" is advanced to the next non-white after the recognized expression.
2170  *
2171  * Return OK or FAIL.
2172  */
2173     static int
2174 eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2175 {
2176     char_u	*p;
2177     int		getnext;
2178     typval_T	var2;
2179     long	result;
2180     int		first;
2181     int		error = FALSE;
2182 
2183     /*
2184      * Get the first variable.
2185      */
2186     if (eval3(arg, rettv, evalarg) == FAIL)
2187 	return FAIL;
2188 
2189     /*
2190      * Repeat until there is no following "||".
2191      */
2192     first = TRUE;
2193     result = FALSE;
2194     p = eval_next_non_blank(*arg, evalarg, &getnext);
2195     while (p[0] == '|' && p[1] == '|')
2196     {
2197 	evalarg_T   nested_evalarg;
2198 	int	    evaluate;
2199 	int	    orig_flags;
2200 
2201 	if (getnext)
2202 	    *arg = eval_next_line(evalarg);
2203 
2204 	if (evalarg == NULL)
2205 	{
2206 	    CLEAR_FIELD(nested_evalarg);
2207 	    orig_flags = 0;
2208 	    evaluate = FALSE;
2209 	}
2210 	else
2211 	{
2212 	    nested_evalarg = *evalarg;
2213 	    orig_flags = evalarg->eval_flags;
2214 	    evaluate = orig_flags & EVAL_EVALUATE;
2215 	}
2216 
2217 	if (evaluate && first)
2218 	{
2219 	    if (tv_get_number_chk(rettv, &error) != 0)
2220 		result = TRUE;
2221 	    clear_tv(rettv);
2222 	    if (error)
2223 		return FAIL;
2224 	    first = FALSE;
2225 	}
2226 
2227 	/*
2228 	 * Get the second variable.
2229 	 */
2230 	*arg = skipwhite_and_linebreak(*arg + 2, evalarg);
2231 	nested_evalarg.eval_flags = !result ? orig_flags
2232 						 : orig_flags & ~EVAL_EVALUATE;
2233 	if (eval3(arg, &var2, &nested_evalarg) == FAIL)
2234 	    return FAIL;
2235 
2236 	/*
2237 	 * Compute the result.
2238 	 */
2239 	if (evaluate && !result)
2240 	{
2241 	    if (tv_get_number_chk(&var2, &error) != 0)
2242 		result = TRUE;
2243 	    clear_tv(&var2);
2244 	    if (error)
2245 		return FAIL;
2246 	}
2247 	if (evaluate)
2248 	{
2249 	    rettv->v_type = VAR_NUMBER;
2250 	    rettv->vval.v_number = result;
2251 	}
2252 
2253 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2254     }
2255 
2256     return OK;
2257 }
2258 
2259 /*
2260  * Handle second level expression:
2261  *	expr3 && expr3 && expr3	    logical AND
2262  *
2263  * "arg" must point to the first non-white of the expression.
2264  * "arg" is advanced to the next non-white after the recognized expression.
2265  *
2266  * Return OK or FAIL.
2267  */
2268     static int
2269 eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2270 {
2271     char_u	*p;
2272     int		getnext;
2273     typval_T	var2;
2274     long	result;
2275     int		first;
2276     int		error = FALSE;
2277 
2278     /*
2279      * Get the first variable.
2280      */
2281     if (eval4(arg, rettv, evalarg) == FAIL)
2282 	return FAIL;
2283 
2284     /*
2285      * Repeat until there is no following "&&".
2286      */
2287     first = TRUE;
2288     result = TRUE;
2289     p = eval_next_non_blank(*arg, evalarg, &getnext);
2290     while (p[0] == '&' && p[1] == '&')
2291     {
2292 	evalarg_T   nested_evalarg;
2293 	int	    orig_flags;
2294 	int	    evaluate;
2295 
2296 	if (getnext)
2297 	    *arg = eval_next_line(evalarg);
2298 
2299 	if (evalarg == NULL)
2300 	{
2301 	    CLEAR_FIELD(nested_evalarg);
2302 	    orig_flags = 0;
2303 	    evaluate = FALSE;
2304 	}
2305 	else
2306 	{
2307 	    nested_evalarg = *evalarg;
2308 	    orig_flags = evalarg->eval_flags;
2309 	    evaluate = orig_flags & EVAL_EVALUATE;
2310 	}
2311 	if (evaluate && first)
2312 	{
2313 	    if (tv_get_number_chk(rettv, &error) == 0)
2314 		result = FALSE;
2315 	    clear_tv(rettv);
2316 	    if (error)
2317 		return FAIL;
2318 	    first = FALSE;
2319 	}
2320 
2321 	/*
2322 	 * Get the second variable.
2323 	 */
2324 	*arg = skipwhite_and_linebreak(*arg + 2, evalarg);
2325 	nested_evalarg.eval_flags = result ? orig_flags
2326 						 : orig_flags & ~EVAL_EVALUATE;
2327 	if (eval4(arg, &var2, &nested_evalarg) == FAIL)
2328 	    return FAIL;
2329 
2330 	/*
2331 	 * Compute the result.
2332 	 */
2333 	if (evaluate && result)
2334 	{
2335 	    if (tv_get_number_chk(&var2, &error) == 0)
2336 		result = FALSE;
2337 	    clear_tv(&var2);
2338 	    if (error)
2339 		return FAIL;
2340 	}
2341 	if (evaluate)
2342 	{
2343 	    rettv->v_type = VAR_NUMBER;
2344 	    rettv->vval.v_number = result;
2345 	}
2346 
2347 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2348     }
2349 
2350     return OK;
2351 }
2352 
2353 /*
2354  * Handle third level expression:
2355  *	var1 == var2
2356  *	var1 =~ var2
2357  *	var1 != var2
2358  *	var1 !~ var2
2359  *	var1 > var2
2360  *	var1 >= var2
2361  *	var1 < var2
2362  *	var1 <= var2
2363  *	var1 is var2
2364  *	var1 isnot var2
2365  *
2366  * "arg" must point to the first non-white of the expression.
2367  * "arg" is advanced to the next non-white after the recognized expression.
2368  *
2369  * Return OK or FAIL.
2370  */
2371     static int
2372 eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2373 {
2374     typval_T	var2;
2375     char_u	*p;
2376     int		getnext;
2377     int		i;
2378     exptype_T	type = EXPR_UNKNOWN;
2379     int		len = 2;
2380     int		ic;
2381 
2382     /*
2383      * Get the first variable.
2384      */
2385     if (eval5(arg, rettv, evalarg) == FAIL)
2386 	return FAIL;
2387 
2388     p = eval_next_non_blank(*arg, evalarg, &getnext);
2389     switch (p[0])
2390     {
2391 	case '=':   if (p[1] == '=')
2392 			type = EXPR_EQUAL;
2393 		    else if (p[1] == '~')
2394 			type = EXPR_MATCH;
2395 		    break;
2396 	case '!':   if (p[1] == '=')
2397 			type = EXPR_NEQUAL;
2398 		    else if (p[1] == '~')
2399 			type = EXPR_NOMATCH;
2400 		    break;
2401 	case '>':   if (p[1] != '=')
2402 		    {
2403 			type = EXPR_GREATER;
2404 			len = 1;
2405 		    }
2406 		    else
2407 			type = EXPR_GEQUAL;
2408 		    break;
2409 	case '<':   if (p[1] != '=')
2410 		    {
2411 			type = EXPR_SMALLER;
2412 			len = 1;
2413 		    }
2414 		    else
2415 			type = EXPR_SEQUAL;
2416 		    break;
2417 	case 'i':   if (p[1] == 's')
2418 		    {
2419 			if (p[2] == 'n' && p[3] == 'o' && p[4] == 't')
2420 			    len = 5;
2421 			i = p[len];
2422 			if (!isalnum(i) && i != '_')
2423 			    type = len == 2 ? EXPR_IS : EXPR_ISNOT;
2424 		    }
2425 		    break;
2426     }
2427 
2428     /*
2429      * If there is a comparative operator, use it.
2430      */
2431     if (type != EXPR_UNKNOWN)
2432     {
2433 	if (getnext)
2434 	    *arg = eval_next_line(evalarg);
2435 
2436 	// extra question mark appended: ignore case
2437 	if (p[len] == '?')
2438 	{
2439 	    ic = TRUE;
2440 	    ++len;
2441 	}
2442 	// extra '#' appended: match case
2443 	else if (p[len] == '#')
2444 	{
2445 	    ic = FALSE;
2446 	    ++len;
2447 	}
2448 	// nothing appended: use 'ignorecase'
2449 	else
2450 	    ic = p_ic;
2451 
2452 	/*
2453 	 * Get the second variable.
2454 	 */
2455 	*arg = skipwhite_and_linebreak(p + len, evalarg);
2456 	if (eval5(arg, &var2, evalarg) == FAIL)
2457 	{
2458 	    clear_tv(rettv);
2459 	    return FAIL;
2460 	}
2461 	if (evalarg != NULL && (evalarg->eval_flags & EVAL_EVALUATE))
2462 	{
2463 	    int ret = typval_compare(rettv, &var2, type, ic);
2464 
2465 	    clear_tv(&var2);
2466 	    return ret;
2467 	}
2468     }
2469 
2470     return OK;
2471 }
2472 
2473     void
2474 eval_addblob(typval_T *tv1, typval_T *tv2)
2475 {
2476     blob_T  *b1 = tv1->vval.v_blob;
2477     blob_T  *b2 = tv2->vval.v_blob;
2478     blob_T  *b = blob_alloc();
2479     int	    i;
2480 
2481     if (b != NULL)
2482     {
2483 	for (i = 0; i < blob_len(b1); i++)
2484 	    ga_append(&b->bv_ga, blob_get(b1, i));
2485 	for (i = 0; i < blob_len(b2); i++)
2486 	    ga_append(&b->bv_ga, blob_get(b2, i));
2487 
2488 	clear_tv(tv1);
2489 	rettv_blob_set(tv1, b);
2490     }
2491 }
2492 
2493     int
2494 eval_addlist(typval_T *tv1, typval_T *tv2)
2495 {
2496     typval_T var3;
2497 
2498     // concatenate Lists
2499     if (list_concat(tv1->vval.v_list, tv2->vval.v_list, &var3) == FAIL)
2500     {
2501 	clear_tv(tv1);
2502 	clear_tv(tv2);
2503 	return FAIL;
2504     }
2505     clear_tv(tv1);
2506     *tv1 = var3;
2507     return OK;
2508 }
2509 
2510 /*
2511  * Handle fourth level expression:
2512  *	+	number addition
2513  *	-	number subtraction
2514  *	.	string concatenation (if script version is 1)
2515  *	..	string concatenation
2516  *
2517  * "arg" must point to the first non-white of the expression.
2518  * "arg" is advanced to the next non-white after the recognized expression.
2519  *
2520  * Return OK or FAIL.
2521  */
2522     static int
2523 eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2524 {
2525     int	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2526 
2527     /*
2528      * Get the first variable.
2529      */
2530     if (eval6(arg, rettv, evalarg, FALSE) == FAIL)
2531 	return FAIL;
2532 
2533     /*
2534      * Repeat computing, until no '+', '-' or '.' is following.
2535      */
2536     for (;;)
2537     {
2538 	int	    getnext;
2539 	char_u	    *p;
2540 	int	    op;
2541 	int	    concat;
2542 	typval_T    var2;
2543 
2544 	// "." is only string concatenation when scriptversion is 1
2545 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2546 	op = *p;
2547 	concat = op == '.' && (*(p + 1) == '.' || current_sctx.sc_version < 2);
2548 	if (op != '+' && op != '-' && !concat)
2549 	    break;
2550 	if (getnext)
2551 	    *arg = eval_next_line(evalarg);
2552 
2553 	if ((op != '+' || (rettv->v_type != VAR_LIST
2554 						 && rettv->v_type != VAR_BLOB))
2555 #ifdef FEAT_FLOAT
2556 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2557 #endif
2558 		)
2559 	{
2560 	    // For "list + ...", an illegal use of the first operand as
2561 	    // a number cannot be determined before evaluating the 2nd
2562 	    // operand: if this is also a list, all is ok.
2563 	    // For "something . ...", "something - ..." or "non-list + ...",
2564 	    // we know that the first operand needs to be a string or number
2565 	    // without evaluating the 2nd operand.  So check before to avoid
2566 	    // side effects after an error.
2567 	    if (evaluate && tv_get_string_chk(rettv) == NULL)
2568 	    {
2569 		clear_tv(rettv);
2570 		return FAIL;
2571 	    }
2572 	}
2573 
2574 	/*
2575 	 * Get the second variable.
2576 	 */
2577 	if (op == '.' && *(*arg + 1) == '.')  // .. string concatenation
2578 	    ++*arg;
2579 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
2580 	if (eval6(arg, &var2, evalarg, op == '.') == FAIL)
2581 	{
2582 	    clear_tv(rettv);
2583 	    return FAIL;
2584 	}
2585 
2586 	if (evaluate)
2587 	{
2588 	    /*
2589 	     * Compute the result.
2590 	     */
2591 	    if (op == '.')
2592 	    {
2593 		char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
2594 		char_u	*s1 = tv_get_string_buf(rettv, buf1);
2595 		char_u	*s2 = tv_get_string_buf_chk(&var2, buf2);
2596 
2597 		if (s2 == NULL)		// type error ?
2598 		{
2599 		    clear_tv(rettv);
2600 		    clear_tv(&var2);
2601 		    return FAIL;
2602 		}
2603 		p = concat_str(s1, s2);
2604 		clear_tv(rettv);
2605 		rettv->v_type = VAR_STRING;
2606 		rettv->vval.v_string = p;
2607 	    }
2608 	    else if (op == '+' && rettv->v_type == VAR_BLOB
2609 						   && var2.v_type == VAR_BLOB)
2610 		eval_addblob(rettv, &var2);
2611 	    else if (op == '+' && rettv->v_type == VAR_LIST
2612 						   && var2.v_type == VAR_LIST)
2613 	    {
2614 		if (eval_addlist(rettv, &var2) == FAIL)
2615 		    return FAIL;
2616 	    }
2617 	    else
2618 	    {
2619 		int		error = FALSE;
2620 		varnumber_T	n1, n2;
2621 #ifdef FEAT_FLOAT
2622 		float_T	    f1 = 0, f2 = 0;
2623 
2624 		if (rettv->v_type == VAR_FLOAT)
2625 		{
2626 		    f1 = rettv->vval.v_float;
2627 		    n1 = 0;
2628 		}
2629 		else
2630 #endif
2631 		{
2632 		    n1 = tv_get_number_chk(rettv, &error);
2633 		    if (error)
2634 		    {
2635 			// This can only happen for "list + non-list".  For
2636 			// "non-list + ..." or "something - ...", we returned
2637 			// before evaluating the 2nd operand.
2638 			clear_tv(rettv);
2639 			return FAIL;
2640 		    }
2641 #ifdef FEAT_FLOAT
2642 		    if (var2.v_type == VAR_FLOAT)
2643 			f1 = n1;
2644 #endif
2645 		}
2646 #ifdef FEAT_FLOAT
2647 		if (var2.v_type == VAR_FLOAT)
2648 		{
2649 		    f2 = var2.vval.v_float;
2650 		    n2 = 0;
2651 		}
2652 		else
2653 #endif
2654 		{
2655 		    n2 = tv_get_number_chk(&var2, &error);
2656 		    if (error)
2657 		    {
2658 			clear_tv(rettv);
2659 			clear_tv(&var2);
2660 			return FAIL;
2661 		    }
2662 #ifdef FEAT_FLOAT
2663 		    if (rettv->v_type == VAR_FLOAT)
2664 			f2 = n2;
2665 #endif
2666 		}
2667 		clear_tv(rettv);
2668 
2669 #ifdef FEAT_FLOAT
2670 		// If there is a float on either side the result is a float.
2671 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
2672 		{
2673 		    if (op == '+')
2674 			f1 = f1 + f2;
2675 		    else
2676 			f1 = f1 - f2;
2677 		    rettv->v_type = VAR_FLOAT;
2678 		    rettv->vval.v_float = f1;
2679 		}
2680 		else
2681 #endif
2682 		{
2683 		    if (op == '+')
2684 			n1 = n1 + n2;
2685 		    else
2686 			n1 = n1 - n2;
2687 		    rettv->v_type = VAR_NUMBER;
2688 		    rettv->vval.v_number = n1;
2689 		}
2690 	    }
2691 	    clear_tv(&var2);
2692 	}
2693     }
2694     return OK;
2695 }
2696 
2697 /*
2698  * Handle fifth level expression:
2699  *	*	number multiplication
2700  *	/	number division
2701  *	%	number modulo
2702  *
2703  * "arg" must point to the first non-white of the expression.
2704  * "arg" is advanced to the next non-white after the recognized expression.
2705  *
2706  * Return OK or FAIL.
2707  */
2708     static int
2709 eval6(
2710     char_u	**arg,
2711     typval_T	*rettv,
2712     evalarg_T	*evalarg,
2713     int		want_string)  // after "." operator
2714 {
2715     typval_T	var2;
2716     int		op;
2717     varnumber_T	n1, n2;
2718 #ifdef FEAT_FLOAT
2719     int		use_float = FALSE;
2720     float_T	f1 = 0, f2 = 0;
2721 #endif
2722     int		error = FALSE;
2723 
2724     /*
2725      * Get the first variable.
2726      */
2727     if (eval7(arg, rettv, evalarg, want_string) == FAIL)
2728 	return FAIL;
2729 
2730     /*
2731      * Repeat computing, until no '*', '/' or '%' is following.
2732      */
2733     for (;;)
2734     {
2735 	int	evaluate = evalarg == NULL ? 0
2736 				       : (evalarg->eval_flags & EVAL_EVALUATE);
2737 	int	getnext;
2738 
2739 	op = *eval_next_non_blank(*arg, evalarg, &getnext);
2740 	if (op != '*' && op != '/' && op != '%')
2741 	    break;
2742 	if (getnext)
2743 	    *arg = eval_next_line(evalarg);
2744 
2745 	if (evaluate)
2746 	{
2747 #ifdef FEAT_FLOAT
2748 	    if (rettv->v_type == VAR_FLOAT)
2749 	    {
2750 		f1 = rettv->vval.v_float;
2751 		use_float = TRUE;
2752 		n1 = 0;
2753 	    }
2754 	    else
2755 #endif
2756 		n1 = tv_get_number_chk(rettv, &error);
2757 	    clear_tv(rettv);
2758 	    if (error)
2759 		return FAIL;
2760 	}
2761 	else
2762 	    n1 = 0;
2763 
2764 	/*
2765 	 * Get the second variable.
2766 	 */
2767 	*arg = skipwhite(*arg + 1);
2768 	if (eval7(arg, &var2, evalarg, FALSE) == FAIL)
2769 	    return FAIL;
2770 
2771 	if (evaluate)
2772 	{
2773 #ifdef FEAT_FLOAT
2774 	    if (var2.v_type == VAR_FLOAT)
2775 	    {
2776 		if (!use_float)
2777 		{
2778 		    f1 = n1;
2779 		    use_float = TRUE;
2780 		}
2781 		f2 = var2.vval.v_float;
2782 		n2 = 0;
2783 	    }
2784 	    else
2785 #endif
2786 	    {
2787 		n2 = tv_get_number_chk(&var2, &error);
2788 		clear_tv(&var2);
2789 		if (error)
2790 		    return FAIL;
2791 #ifdef FEAT_FLOAT
2792 		if (use_float)
2793 		    f2 = n2;
2794 #endif
2795 	    }
2796 
2797 	    /*
2798 	     * Compute the result.
2799 	     * When either side is a float the result is a float.
2800 	     */
2801 #ifdef FEAT_FLOAT
2802 	    if (use_float)
2803 	    {
2804 		if (op == '*')
2805 		    f1 = f1 * f2;
2806 		else if (op == '/')
2807 		{
2808 # ifdef VMS
2809 		    // VMS crashes on divide by zero, work around it
2810 		    if (f2 == 0.0)
2811 		    {
2812 			if (f1 == 0)
2813 			    f1 = -1 * __F_FLT_MAX - 1L;   // similar to NaN
2814 			else if (f1 < 0)
2815 			    f1 = -1 * __F_FLT_MAX;
2816 			else
2817 			    f1 = __F_FLT_MAX;
2818 		    }
2819 		    else
2820 			f1 = f1 / f2;
2821 # else
2822 		    // We rely on the floating point library to handle divide
2823 		    // by zero to result in "inf" and not a crash.
2824 		    f1 = f1 / f2;
2825 # endif
2826 		}
2827 		else
2828 		{
2829 		    emsg(_(e_modulus));
2830 		    return FAIL;
2831 		}
2832 		rettv->v_type = VAR_FLOAT;
2833 		rettv->vval.v_float = f1;
2834 	    }
2835 	    else
2836 #endif
2837 	    {
2838 		if (op == '*')
2839 		    n1 = n1 * n2;
2840 		else if (op == '/')
2841 		    n1 = num_divide(n1, n2);
2842 		else
2843 		    n1 = num_modulus(n1, n2);
2844 
2845 		rettv->v_type = VAR_NUMBER;
2846 		rettv->vval.v_number = n1;
2847 	    }
2848 	}
2849     }
2850 
2851     return OK;
2852 }
2853 
2854 /*
2855  * Handle sixth level expression:
2856  *  number		number constant
2857  *  0zFFFFFFFF		Blob constant
2858  *  "string"		string constant
2859  *  'string'		literal string constant
2860  *  &option-name	option value
2861  *  @r			register contents
2862  *  identifier		variable value
2863  *  function()		function call
2864  *  $VAR		environment variable
2865  *  (expression)	nested expression
2866  *  [expr, expr]	List
2867  *  {arg, arg -> expr}	Lambda
2868  *  {key: val, key: val}   Dictionary
2869  *  #{key: val, key: val}  Dictionary with literal keys
2870  *
2871  *  Also handle:
2872  *  ! in front		logical NOT
2873  *  - in front		unary minus
2874  *  + in front		unary plus (ignored)
2875  *  trailing []		subscript in String or List
2876  *  trailing .name	entry in Dictionary
2877  *  trailing ->name()	method call
2878  *
2879  * "arg" must point to the first non-white of the expression.
2880  * "arg" is advanced to the next non-white after the recognized expression.
2881  *
2882  * Return OK or FAIL.
2883  */
2884     static int
2885 eval7(
2886     char_u	**arg,
2887     typval_T	*rettv,
2888     evalarg_T	*evalarg,
2889     int		want_string)	// after "." operator
2890 {
2891     int		flags = evalarg == NULL ? 0 : evalarg->eval_flags;
2892     int		evaluate = evalarg != NULL
2893 				      && (evalarg->eval_flags & EVAL_EVALUATE);
2894     int		len;
2895     char_u	*s;
2896     char_u	*start_leader, *end_leader;
2897     int		ret = OK;
2898     char_u	*alias;
2899 
2900     /*
2901      * Initialise variable so that clear_tv() can't mistake this for a
2902      * string and free a string that isn't there.
2903      */
2904     rettv->v_type = VAR_UNKNOWN;
2905 
2906     /*
2907      * Skip '!', '-' and '+' characters.  They are handled later.
2908      */
2909     start_leader = *arg;
2910     while (**arg == '!' || **arg == '-' || **arg == '+')
2911 	*arg = skipwhite(*arg + 1);
2912     end_leader = *arg;
2913 
2914     if (**arg == '.' && (!isdigit(*(*arg + 1))
2915 #ifdef FEAT_FLOAT
2916 	    || current_sctx.sc_version < 2
2917 #endif
2918 	    ))
2919     {
2920 	semsg(_(e_invexpr2), *arg);
2921 	++*arg;
2922 	return FAIL;
2923     }
2924 
2925     switch (**arg)
2926     {
2927     /*
2928      * Number constant.
2929      */
2930     case '0':
2931     case '1':
2932     case '2':
2933     case '3':
2934     case '4':
2935     case '5':
2936     case '6':
2937     case '7':
2938     case '8':
2939     case '9':
2940     case '.':	ret = eval_number(arg, rettv, evaluate, want_string);
2941 
2942 		// Apply prefixed "-" and "+" now.  Matters especially when
2943 		// "->" follows.
2944 		if (ret == OK && evaluate && end_leader > start_leader)
2945 		    ret = eval7_leader(rettv, TRUE, start_leader, &end_leader);
2946 		break;
2947 
2948     /*
2949      * String constant: "string".
2950      */
2951     case '"':	ret = eval_string(arg, rettv, evaluate);
2952 		break;
2953 
2954     /*
2955      * Literal string constant: 'str''ing'.
2956      */
2957     case '\'':	ret = eval_lit_string(arg, rettv, evaluate);
2958 		break;
2959 
2960     /*
2961      * List: [expr, expr]
2962      */
2963     case '[':	ret = eval_list(arg, rettv, evalarg, TRUE);
2964 		break;
2965 
2966     /*
2967      * Dictionary: #{key: val, key: val}
2968      */
2969     case '#':	if ((*arg)[1] == '{')
2970 		{
2971 		    ++*arg;
2972 		    ret = eval_dict(arg, rettv, evalarg, TRUE);
2973 		}
2974 		else
2975 		    ret = NOTDONE;
2976 		break;
2977 
2978     /*
2979      * Lambda: {arg, arg -> expr}
2980      * Dictionary: {'key': val, 'key': val}
2981      */
2982     case '{':	ret = get_lambda_tv(arg, rettv, evalarg);
2983 		if (ret == NOTDONE)
2984 		    ret = eval_dict(arg, rettv, evalarg, FALSE);
2985 		break;
2986 
2987     /*
2988      * Option value: &name
2989      */
2990     case '&':	ret = eval_option(arg, rettv, evaluate);
2991 		break;
2992 
2993     /*
2994      * Environment variable: $VAR.
2995      */
2996     case '$':	ret = eval_env_var(arg, rettv, evaluate);
2997 		break;
2998 
2999     /*
3000      * Register contents: @r.
3001      */
3002     case '@':	++*arg;
3003 		if (evaluate)
3004 		{
3005 		    rettv->v_type = VAR_STRING;
3006 		    rettv->vval.v_string = get_reg_contents(**arg,
3007 							    GREG_EXPR_SRC);
3008 		}
3009 		if (**arg != NUL)
3010 		    ++*arg;
3011 		break;
3012 
3013     /*
3014      * nested expression: (expression).
3015      */
3016     case '(':	{
3017 		    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3018 		    ret = eval1(arg, rettv, evalarg);	// recursive!
3019 
3020 		    *arg = skipwhite_and_linebreak(*arg, evalarg);
3021 		    if (**arg == ')')
3022 			++*arg;
3023 		    else if (ret == OK)
3024 		    {
3025 			emsg(_(e_missing_close));
3026 			clear_tv(rettv);
3027 			ret = FAIL;
3028 		    }
3029 		}
3030 		break;
3031 
3032     default:	ret = NOTDONE;
3033 		break;
3034     }
3035 
3036     if (ret == NOTDONE)
3037     {
3038 	/*
3039 	 * Must be a variable or function name.
3040 	 * Can also be a curly-braces kind of name: {expr}.
3041 	 */
3042 	s = *arg;
3043 	len = get_name_len(arg, &alias, evaluate, TRUE);
3044 	if (alias != NULL)
3045 	    s = alias;
3046 
3047 	if (len <= 0)
3048 	    ret = FAIL;
3049 	else
3050 	{
3051 	    if (**arg == '(')
3052 		// "name(..."  recursive!
3053 		ret = eval_func(arg, evalarg, s, len, rettv, flags, NULL);
3054 	    else if (flags & EVAL_CONSTANT)
3055 		ret = FAIL;
3056 	    else if (evaluate)
3057 		// get value of variable
3058 		ret = eval_variable(s, len, rettv, NULL, TRUE, FALSE);
3059 	    else
3060 	    {
3061 		// skip the name
3062 		check_vars(s, len);
3063 		ret = OK;
3064 	    }
3065 	}
3066 	vim_free(alias);
3067     }
3068 
3069     *arg = skipwhite(*arg);
3070 
3071     // Handle following '[', '(' and '.' for expr[expr], expr.name,
3072     // expr(expr), expr->name(expr)
3073     if (ret == OK)
3074 	ret = handle_subscript(arg, rettv, evalarg, TRUE);
3075 
3076     /*
3077      * Apply logical NOT and unary '-', from right to left, ignore '+'.
3078      */
3079     if (ret == OK && evaluate && end_leader > start_leader)
3080 	ret = eval7_leader(rettv, FALSE, start_leader, &end_leader);
3081     return ret;
3082 }
3083 
3084 /*
3085  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
3086  * When "numeric_only" is TRUE only handle "+" and "-".
3087  * Adjusts "end_leaderp" until it is at "start_leader".
3088  */
3089     static int
3090 eval7_leader(
3091 	typval_T    *rettv,
3092 	int	    numeric_only,
3093 	char_u	    *start_leader,
3094 	char_u	    **end_leaderp)
3095 {
3096     char_u	*end_leader = *end_leaderp;
3097     int		ret = OK;
3098     int		error = FALSE;
3099     varnumber_T val = 0;
3100 #ifdef FEAT_FLOAT
3101     float_T	    f = 0.0;
3102 
3103     if (rettv->v_type == VAR_FLOAT)
3104 	f = rettv->vval.v_float;
3105     else
3106 #endif
3107 	val = tv_get_number_chk(rettv, &error);
3108     if (error)
3109     {
3110 	clear_tv(rettv);
3111 	ret = FAIL;
3112     }
3113     else
3114     {
3115 	while (end_leader > start_leader)
3116 	{
3117 	    --end_leader;
3118 	    if (*end_leader == '!')
3119 	    {
3120 		if (numeric_only)
3121 		{
3122 		    ++end_leader;
3123 		    break;
3124 		}
3125 #ifdef FEAT_FLOAT
3126 		if (rettv->v_type == VAR_FLOAT)
3127 		    f = !f;
3128 		else
3129 #endif
3130 		    val = !val;
3131 	    }
3132 	    else if (*end_leader == '-')
3133 	    {
3134 #ifdef FEAT_FLOAT
3135 		if (rettv->v_type == VAR_FLOAT)
3136 		    f = -f;
3137 		else
3138 #endif
3139 		    val = -val;
3140 	    }
3141 	}
3142 #ifdef FEAT_FLOAT
3143 	if (rettv->v_type == VAR_FLOAT)
3144 	{
3145 	    clear_tv(rettv);
3146 	    rettv->vval.v_float = f;
3147 	}
3148 	else
3149 #endif
3150 	{
3151 	    clear_tv(rettv);
3152 	    rettv->v_type = VAR_NUMBER;
3153 	    rettv->vval.v_number = val;
3154 	}
3155     }
3156     *end_leaderp = end_leader;
3157     return ret;
3158 }
3159 
3160 /*
3161  * Call the function referred to in "rettv".
3162  */
3163     static int
3164 call_func_rettv(
3165 	char_u	    **arg,
3166 	evalarg_T   *evalarg,
3167 	typval_T    *rettv,
3168 	int	    evaluate,
3169 	dict_T	    *selfdict,
3170 	typval_T    *basetv)
3171 {
3172     partial_T	*pt = NULL;
3173     funcexe_T	funcexe;
3174     typval_T	functv;
3175     char_u	*s;
3176     int		ret;
3177 
3178     // need to copy the funcref so that we can clear rettv
3179     if (evaluate)
3180     {
3181 	functv = *rettv;
3182 	rettv->v_type = VAR_UNKNOWN;
3183 
3184 	// Invoke the function.  Recursive!
3185 	if (functv.v_type == VAR_PARTIAL)
3186 	{
3187 	    pt = functv.vval.v_partial;
3188 	    s = partial_name(pt);
3189 	}
3190 	else
3191 	    s = functv.vval.v_string;
3192     }
3193     else
3194 	s = (char_u *)"";
3195 
3196     CLEAR_FIELD(funcexe);
3197     funcexe.firstline = curwin->w_cursor.lnum;
3198     funcexe.lastline = curwin->w_cursor.lnum;
3199     funcexe.evaluate = evaluate;
3200     funcexe.partial = pt;
3201     funcexe.selfdict = selfdict;
3202     funcexe.basetv = basetv;
3203     ret = get_func_tv(s, -1, rettv, arg, evalarg, &funcexe);
3204 
3205     // Clear the funcref afterwards, so that deleting it while
3206     // evaluating the arguments is possible (see test55).
3207     if (evaluate)
3208 	clear_tv(&functv);
3209 
3210     return ret;
3211 }
3212 
3213 /*
3214  * Evaluate "->method()".
3215  * "*arg" points to the '-'.
3216  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3217  */
3218     static int
3219 eval_lambda(
3220     char_u	**arg,
3221     typval_T	*rettv,
3222     evalarg_T	*evalarg,
3223     int		verbose)	// give error messages
3224 {
3225     int		evaluate = evalarg != NULL
3226 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3227     typval_T	base = *rettv;
3228     int		ret;
3229 
3230     // Skip over the ->.
3231     *arg += 2;
3232     rettv->v_type = VAR_UNKNOWN;
3233 
3234     ret = get_lambda_tv(arg, rettv, evalarg);
3235     if (ret != OK)
3236 	return FAIL;
3237     else if (**arg != '(')
3238     {
3239 	if (verbose)
3240 	{
3241 	    if (*skipwhite(*arg) == '(')
3242 		emsg(_(e_nowhitespace));
3243 	    else
3244 		semsg(_(e_missing_paren), "lambda");
3245 	}
3246 	clear_tv(rettv);
3247 	ret = FAIL;
3248     }
3249     else
3250 	ret = call_func_rettv(arg, evalarg, rettv, evaluate, NULL, &base);
3251 
3252     // Clear the funcref afterwards, so that deleting it while
3253     // evaluating the arguments is possible (see test55).
3254     if (evaluate)
3255 	clear_tv(&base);
3256 
3257     return ret;
3258 }
3259 
3260 /*
3261  * Evaluate "->method()".
3262  * "*arg" points to the '-'.
3263  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3264  */
3265     static int
3266 eval_method(
3267     char_u	**arg,
3268     typval_T	*rettv,
3269     evalarg_T	*evalarg,
3270     int		verbose)	// give error messages
3271 {
3272     char_u	*name;
3273     long	len;
3274     char_u	*alias;
3275     typval_T	base = *rettv;
3276     int		ret;
3277     int		evaluate = evalarg != NULL
3278 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3279 
3280     // Skip over the ->.
3281     *arg += 2;
3282     rettv->v_type = VAR_UNKNOWN;
3283 
3284     name = *arg;
3285     len = get_name_len(arg, &alias, evaluate, TRUE);
3286     if (alias != NULL)
3287 	name = alias;
3288 
3289     if (len <= 0)
3290     {
3291 	if (verbose)
3292 	    emsg(_("E260: Missing name after ->"));
3293 	ret = FAIL;
3294     }
3295     else
3296     {
3297 	if (**arg != '(')
3298 	{
3299 	    if (verbose)
3300 		semsg(_(e_missing_paren), name);
3301 	    ret = FAIL;
3302 	}
3303 	else if (VIM_ISWHITE((*arg)[-1]))
3304 	{
3305 	    if (verbose)
3306 		emsg(_(e_nowhitespace));
3307 	    ret = FAIL;
3308 	}
3309 	else
3310 	    ret = eval_func(arg, evalarg, name, len, rettv,
3311 					  evaluate ? EVAL_EVALUATE : 0, &base);
3312     }
3313 
3314     // Clear the funcref afterwards, so that deleting it while
3315     // evaluating the arguments is possible (see test55).
3316     if (evaluate)
3317 	clear_tv(&base);
3318 
3319     return ret;
3320 }
3321 
3322 /*
3323  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
3324  * "*arg" points to the '[' or '.'.
3325  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
3326  */
3327     static int
3328 eval_index(
3329     char_u	**arg,
3330     typval_T	*rettv,
3331     evalarg_T	*evalarg,
3332     int		verbose)	// give error messages
3333 {
3334     int		evaluate = evalarg != NULL
3335 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3336     int		empty1 = FALSE, empty2 = FALSE;
3337     typval_T	var1, var2;
3338     long	i;
3339     long	n1, n2 = 0;
3340     long	len = -1;
3341     int		range = FALSE;
3342     char_u	*s;
3343     char_u	*key = NULL;
3344 
3345     switch (rettv->v_type)
3346     {
3347 	case VAR_FUNC:
3348 	case VAR_PARTIAL:
3349 	    if (verbose)
3350 		emsg(_("E695: Cannot index a Funcref"));
3351 	    return FAIL;
3352 	case VAR_FLOAT:
3353 #ifdef FEAT_FLOAT
3354 	    if (verbose)
3355 		emsg(_(e_float_as_string));
3356 	    return FAIL;
3357 #endif
3358 	case VAR_BOOL:
3359 	case VAR_SPECIAL:
3360 	case VAR_JOB:
3361 	case VAR_CHANNEL:
3362 	    if (verbose)
3363 		emsg(_("E909: Cannot index a special variable"));
3364 	    return FAIL;
3365 	case VAR_UNKNOWN:
3366 	case VAR_ANY:
3367 	case VAR_VOID:
3368 	    if (evaluate)
3369 		return FAIL;
3370 	    // FALLTHROUGH
3371 
3372 	case VAR_STRING:
3373 	case VAR_NUMBER:
3374 	case VAR_LIST:
3375 	case VAR_DICT:
3376 	case VAR_BLOB:
3377 	    break;
3378     }
3379 
3380     init_tv(&var1);
3381     init_tv(&var2);
3382     if (**arg == '.')
3383     {
3384 	/*
3385 	 * dict.name
3386 	 */
3387 	key = *arg + 1;
3388 	for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
3389 	    ;
3390 	if (len == 0)
3391 	    return FAIL;
3392 	*arg = skipwhite(key + len);
3393     }
3394     else
3395     {
3396 	/*
3397 	 * something[idx]
3398 	 *
3399 	 * Get the (first) variable from inside the [].
3400 	 */
3401 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3402 	if (**arg == ':')
3403 	    empty1 = TRUE;
3404 	else if (eval1(arg, &var1, evalarg) == FAIL)	// recursive!
3405 	    return FAIL;
3406 	else if (evaluate && tv_get_string_chk(&var1) == NULL)
3407 	{
3408 	    // not a number or string
3409 	    clear_tv(&var1);
3410 	    return FAIL;
3411 	}
3412 
3413 	/*
3414 	 * Get the second variable from inside the [:].
3415 	 */
3416 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3417 	if (**arg == ':')
3418 	{
3419 	    range = TRUE;
3420 	    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3421 	    if (**arg == ']')
3422 		empty2 = TRUE;
3423 	    else if (eval1(arg, &var2, evalarg) == FAIL)	// recursive!
3424 	    {
3425 		if (!empty1)
3426 		    clear_tv(&var1);
3427 		return FAIL;
3428 	    }
3429 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
3430 	    {
3431 		// not a number or string
3432 		if (!empty1)
3433 		    clear_tv(&var1);
3434 		clear_tv(&var2);
3435 		return FAIL;
3436 	    }
3437 	}
3438 
3439 	// Check for the ']'.
3440 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3441 	if (**arg != ']')
3442 	{
3443 	    if (verbose)
3444 		emsg(_(e_missbrac));
3445 	    clear_tv(&var1);
3446 	    if (range)
3447 		clear_tv(&var2);
3448 	    return FAIL;
3449 	}
3450 	*arg = skipwhite(*arg + 1);	// skip the ']'
3451     }
3452 
3453     if (evaluate)
3454     {
3455 	n1 = 0;
3456 	if (!empty1 && rettv->v_type != VAR_DICT)
3457 	{
3458 	    n1 = tv_get_number(&var1);
3459 	    clear_tv(&var1);
3460 	}
3461 	if (range)
3462 	{
3463 	    if (empty2)
3464 		n2 = -1;
3465 	    else
3466 	    {
3467 		n2 = tv_get_number(&var2);
3468 		clear_tv(&var2);
3469 	    }
3470 	}
3471 
3472 	switch (rettv->v_type)
3473 	{
3474 	    case VAR_UNKNOWN:
3475 	    case VAR_ANY:
3476 	    case VAR_VOID:
3477 	    case VAR_FUNC:
3478 	    case VAR_PARTIAL:
3479 	    case VAR_FLOAT:
3480 	    case VAR_BOOL:
3481 	    case VAR_SPECIAL:
3482 	    case VAR_JOB:
3483 	    case VAR_CHANNEL:
3484 		break; // not evaluating, skipping over subscript
3485 
3486 	    case VAR_NUMBER:
3487 	    case VAR_STRING:
3488 		s = tv_get_string(rettv);
3489 		len = (long)STRLEN(s);
3490 		if (range)
3491 		{
3492 		    // The resulting variable is a substring.  If the indexes
3493 		    // are out of range the result is empty.
3494 		    if (n1 < 0)
3495 		    {
3496 			n1 = len + n1;
3497 			if (n1 < 0)
3498 			    n1 = 0;
3499 		    }
3500 		    if (n2 < 0)
3501 			n2 = len + n2;
3502 		    else if (n2 >= len)
3503 			n2 = len;
3504 		    if (n1 >= len || n2 < 0 || n1 > n2)
3505 			s = NULL;
3506 		    else
3507 			s = vim_strnsave(s + n1, n2 - n1 + 1);
3508 		}
3509 		else
3510 		{
3511 		    // The resulting variable is a string of a single
3512 		    // character.  If the index is too big or negative the
3513 		    // result is empty.
3514 		    if (n1 >= len || n1 < 0)
3515 			s = NULL;
3516 		    else
3517 			s = vim_strnsave(s + n1, 1);
3518 		}
3519 		clear_tv(rettv);
3520 		rettv->v_type = VAR_STRING;
3521 		rettv->vval.v_string = s;
3522 		break;
3523 
3524 	    case VAR_BLOB:
3525 		len = blob_len(rettv->vval.v_blob);
3526 		if (range)
3527 		{
3528 		    // The resulting variable is a sub-blob.  If the indexes
3529 		    // are out of range the result is empty.
3530 		    if (n1 < 0)
3531 		    {
3532 			n1 = len + n1;
3533 			if (n1 < 0)
3534 			    n1 = 0;
3535 		    }
3536 		    if (n2 < 0)
3537 			n2 = len + n2;
3538 		    else if (n2 >= len)
3539 			n2 = len - 1;
3540 		    if (n1 >= len || n2 < 0 || n1 > n2)
3541 		    {
3542 			clear_tv(rettv);
3543 			rettv->v_type = VAR_BLOB;
3544 			rettv->vval.v_blob = NULL;
3545 		    }
3546 		    else
3547 		    {
3548 			blob_T  *blob = blob_alloc();
3549 
3550 			if (blob != NULL)
3551 			{
3552 			    if (ga_grow(&blob->bv_ga, n2 - n1 + 1) == FAIL)
3553 			    {
3554 				blob_free(blob);
3555 				return FAIL;
3556 			    }
3557 			    blob->bv_ga.ga_len = n2 - n1 + 1;
3558 			    for (i = n1; i <= n2; i++)
3559 				blob_set(blob, i - n1,
3560 					      blob_get(rettv->vval.v_blob, i));
3561 
3562 			    clear_tv(rettv);
3563 			    rettv_blob_set(rettv, blob);
3564 			}
3565 		    }
3566 		}
3567 		else
3568 		{
3569 		    // The resulting variable is a byte value.
3570 		    // If the index is too big or negative that is an error.
3571 		    if (n1 < 0)
3572 			n1 = len + n1;
3573 		    if (n1 < len && n1 >= 0)
3574 		    {
3575 			int v = blob_get(rettv->vval.v_blob, n1);
3576 
3577 			clear_tv(rettv);
3578 			rettv->v_type = VAR_NUMBER;
3579 			rettv->vval.v_number = v;
3580 		    }
3581 		    else
3582 			semsg(_(e_blobidx), n1);
3583 		}
3584 		break;
3585 
3586 	    case VAR_LIST:
3587 		len = list_len(rettv->vval.v_list);
3588 		if (n1 < 0)
3589 		    n1 = len + n1;
3590 		if (!empty1 && (n1 < 0 || n1 >= len))
3591 		{
3592 		    // For a range we allow invalid values and return an empty
3593 		    // list.  A list index out of range is an error.
3594 		    if (!range)
3595 		    {
3596 			if (verbose)
3597 			    semsg(_(e_listidx), n1);
3598 			return FAIL;
3599 		    }
3600 		    n1 = len;
3601 		}
3602 		if (range)
3603 		{
3604 		    list_T	*l;
3605 
3606 		    if (n2 < 0)
3607 			n2 = len + n2;
3608 		    else if (n2 >= len)
3609 			n2 = len - 1;
3610 		    if (!empty2 && (n2 < 0 || n2 + 1 < n1))
3611 			n2 = -1;
3612 		    l = list_slice(rettv->vval.v_list, n1, n2);
3613 		    if (l == NULL)
3614 			return FAIL;
3615 		    clear_tv(rettv);
3616 		    rettv_list_set(rettv, l);
3617 		}
3618 		else
3619 		{
3620 		    copy_tv(&list_find(rettv->vval.v_list, n1)->li_tv, &var1);
3621 		    clear_tv(rettv);
3622 		    *rettv = var1;
3623 		}
3624 		break;
3625 
3626 	    case VAR_DICT:
3627 		if (range)
3628 		{
3629 		    if (verbose)
3630 			emsg(_(e_dictrange));
3631 		    if (len == -1)
3632 			clear_tv(&var1);
3633 		    return FAIL;
3634 		}
3635 		{
3636 		    dictitem_T	*item;
3637 
3638 		    if (len == -1)
3639 		    {
3640 			key = tv_get_string_chk(&var1);
3641 			if (key == NULL)
3642 			{
3643 			    clear_tv(&var1);
3644 			    return FAIL;
3645 			}
3646 		    }
3647 
3648 		    item = dict_find(rettv->vval.v_dict, key, (int)len);
3649 
3650 		    if (item == NULL && verbose)
3651 			semsg(_(e_dictkey), key);
3652 		    if (len == -1)
3653 			clear_tv(&var1);
3654 		    if (item == NULL)
3655 			return FAIL;
3656 
3657 		    copy_tv(&item->di_tv, &var1);
3658 		    clear_tv(rettv);
3659 		    *rettv = var1;
3660 		}
3661 		break;
3662 	}
3663     }
3664 
3665     return OK;
3666 }
3667 
3668 /*
3669  * Return the function name of partial "pt".
3670  */
3671     char_u *
3672 partial_name(partial_T *pt)
3673 {
3674     if (pt->pt_name != NULL)
3675 	return pt->pt_name;
3676     if (pt->pt_func != NULL)
3677 	return pt->pt_func->uf_name;
3678     return (char_u *)"";
3679 }
3680 
3681     static void
3682 partial_free(partial_T *pt)
3683 {
3684     int i;
3685 
3686     for (i = 0; i < pt->pt_argc; ++i)
3687 	clear_tv(&pt->pt_argv[i]);
3688     vim_free(pt->pt_argv);
3689     dict_unref(pt->pt_dict);
3690     if (pt->pt_name != NULL)
3691     {
3692 	func_unref(pt->pt_name);
3693 	vim_free(pt->pt_name);
3694     }
3695     else
3696 	func_ptr_unref(pt->pt_func);
3697 
3698     if (pt->pt_funcstack != NULL)
3699     {
3700 	// Decrease the reference count for the context of a closure.  If down
3701 	// to zero free it and clear the variables on the stack.
3702 	if (--pt->pt_funcstack->fs_refcount == 0)
3703 	{
3704 	    garray_T	*gap = &pt->pt_funcstack->fs_ga;
3705 	    typval_T	*stack = gap->ga_data;
3706 
3707 	    for (i = 0; i < gap->ga_len; ++i)
3708 		clear_tv(stack + i);
3709 	    ga_clear(gap);
3710 	    vim_free(pt->pt_funcstack);
3711 	}
3712 	pt->pt_funcstack = NULL;
3713     }
3714 
3715     vim_free(pt);
3716 }
3717 
3718 /*
3719  * Unreference a closure: decrement the reference count and free it when it
3720  * becomes zero.
3721  */
3722     void
3723 partial_unref(partial_T *pt)
3724 {
3725     if (pt != NULL && --pt->pt_refcount <= 0)
3726 	partial_free(pt);
3727 }
3728 
3729 /*
3730  * Return the next (unique) copy ID.
3731  * Used for serializing nested structures.
3732  */
3733     int
3734 get_copyID(void)
3735 {
3736     current_copyID += COPYID_INC;
3737     return current_copyID;
3738 }
3739 
3740 /*
3741  * Garbage collection for lists and dictionaries.
3742  *
3743  * We use reference counts to be able to free most items right away when they
3744  * are no longer used.  But for composite items it's possible that it becomes
3745  * unused while the reference count is > 0: When there is a recursive
3746  * reference.  Example:
3747  *	:let l = [1, 2, 3]
3748  *	:let d = {9: l}
3749  *	:let l[1] = d
3750  *
3751  * Since this is quite unusual we handle this with garbage collection: every
3752  * once in a while find out which lists and dicts are not referenced from any
3753  * variable.
3754  *
3755  * Here is a good reference text about garbage collection (refers to Python
3756  * but it applies to all reference-counting mechanisms):
3757  *	http://python.ca/nas/python/gc/
3758  */
3759 
3760 /*
3761  * Do garbage collection for lists and dicts.
3762  * When "testing" is TRUE this is called from test_garbagecollect_now().
3763  * Return TRUE if some memory was freed.
3764  */
3765     int
3766 garbage_collect(int testing)
3767 {
3768     int		copyID;
3769     int		abort = FALSE;
3770     buf_T	*buf;
3771     win_T	*wp;
3772     int		did_free = FALSE;
3773     tabpage_T	*tp;
3774 
3775     if (!testing)
3776     {
3777 	// Only do this once.
3778 	want_garbage_collect = FALSE;
3779 	may_garbage_collect = FALSE;
3780 	garbage_collect_at_exit = FALSE;
3781     }
3782 
3783     // The execution stack can grow big, limit the size.
3784     if (exestack.ga_maxlen - exestack.ga_len > 500)
3785     {
3786 	size_t	new_len;
3787 	char_u	*pp;
3788 	int	n;
3789 
3790 	// Keep 150% of the current size, with a minimum of the growth size.
3791 	n = exestack.ga_len / 2;
3792 	if (n < exestack.ga_growsize)
3793 	    n = exestack.ga_growsize;
3794 
3795 	// Don't make it bigger though.
3796 	if (exestack.ga_len + n < exestack.ga_maxlen)
3797 	{
3798 	    new_len = exestack.ga_itemsize * (exestack.ga_len + n);
3799 	    pp = vim_realloc(exestack.ga_data, new_len);
3800 	    if (pp == NULL)
3801 		return FAIL;
3802 	    exestack.ga_maxlen = exestack.ga_len + n;
3803 	    exestack.ga_data = pp;
3804 	}
3805     }
3806 
3807     // We advance by two because we add one for items referenced through
3808     // previous_funccal.
3809     copyID = get_copyID();
3810 
3811     /*
3812      * 1. Go through all accessible variables and mark all lists and dicts
3813      *    with copyID.
3814      */
3815 
3816     // Don't free variables in the previous_funccal list unless they are only
3817     // referenced through previous_funccal.  This must be first, because if
3818     // the item is referenced elsewhere the funccal must not be freed.
3819     abort = abort || set_ref_in_previous_funccal(copyID);
3820 
3821     // script-local variables
3822     abort = abort || garbage_collect_scriptvars(copyID);
3823 
3824     // buffer-local variables
3825     FOR_ALL_BUFFERS(buf)
3826 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
3827 								  NULL, NULL);
3828 
3829     // window-local variables
3830     FOR_ALL_TAB_WINDOWS(tp, wp)
3831 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3832 								  NULL, NULL);
3833     if (aucmd_win != NULL)
3834 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
3835 								  NULL, NULL);
3836 #ifdef FEAT_PROP_POPUP
3837     FOR_ALL_POPUPWINS(wp)
3838 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3839 								  NULL, NULL);
3840     FOR_ALL_TABPAGES(tp)
3841 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
3842 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
3843 								  NULL, NULL);
3844 #endif
3845 
3846     // tabpage-local variables
3847     FOR_ALL_TABPAGES(tp)
3848 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
3849 								  NULL, NULL);
3850     // global variables
3851     abort = abort || garbage_collect_globvars(copyID);
3852 
3853     // function-local variables
3854     abort = abort || set_ref_in_call_stack(copyID);
3855 
3856     // named functions (matters for closures)
3857     abort = abort || set_ref_in_functions(copyID);
3858 
3859     // function call arguments, if v:testing is set.
3860     abort = abort || set_ref_in_func_args(copyID);
3861 
3862     // v: vars
3863     abort = abort || garbage_collect_vimvars(copyID);
3864 
3865     // callbacks in buffers
3866     abort = abort || set_ref_in_buffers(copyID);
3867 
3868 #ifdef FEAT_LUA
3869     abort = abort || set_ref_in_lua(copyID);
3870 #endif
3871 
3872 #ifdef FEAT_PYTHON
3873     abort = abort || set_ref_in_python(copyID);
3874 #endif
3875 
3876 #ifdef FEAT_PYTHON3
3877     abort = abort || set_ref_in_python3(copyID);
3878 #endif
3879 
3880 #ifdef FEAT_JOB_CHANNEL
3881     abort = abort || set_ref_in_channel(copyID);
3882     abort = abort || set_ref_in_job(copyID);
3883 #endif
3884 #ifdef FEAT_NETBEANS_INTG
3885     abort = abort || set_ref_in_nb_channel(copyID);
3886 #endif
3887 
3888 #ifdef FEAT_TIMERS
3889     abort = abort || set_ref_in_timer(copyID);
3890 #endif
3891 
3892 #ifdef FEAT_QUICKFIX
3893     abort = abort || set_ref_in_quickfix(copyID);
3894 #endif
3895 
3896 #ifdef FEAT_TERMINAL
3897     abort = abort || set_ref_in_term(copyID);
3898 #endif
3899 
3900 #ifdef FEAT_PROP_POPUP
3901     abort = abort || set_ref_in_popups(copyID);
3902 #endif
3903 
3904     if (!abort)
3905     {
3906 	/*
3907 	 * 2. Free lists and dictionaries that are not referenced.
3908 	 */
3909 	did_free = free_unref_items(copyID);
3910 
3911 	/*
3912 	 * 3. Check if any funccal can be freed now.
3913 	 *    This may call us back recursively.
3914 	 */
3915 	free_unref_funccal(copyID, testing);
3916     }
3917     else if (p_verbose > 0)
3918     {
3919 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
3920     }
3921 
3922     return did_free;
3923 }
3924 
3925 /*
3926  * Free lists, dictionaries, channels and jobs that are no longer referenced.
3927  */
3928     static int
3929 free_unref_items(int copyID)
3930 {
3931     int		did_free = FALSE;
3932 
3933     // Let all "free" functions know that we are here.  This means no
3934     // dictionaries, lists, channels or jobs are to be freed, because we will
3935     // do that here.
3936     in_free_unref_items = TRUE;
3937 
3938     /*
3939      * PASS 1: free the contents of the items.  We don't free the items
3940      * themselves yet, so that it is possible to decrement refcount counters
3941      */
3942 
3943     // Go through the list of dicts and free items without the copyID.
3944     did_free |= dict_free_nonref(copyID);
3945 
3946     // Go through the list of lists and free items without the copyID.
3947     did_free |= list_free_nonref(copyID);
3948 
3949 #ifdef FEAT_JOB_CHANNEL
3950     // Go through the list of jobs and free items without the copyID. This
3951     // must happen before doing channels, because jobs refer to channels, but
3952     // the reference from the channel to the job isn't tracked.
3953     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
3954 
3955     // Go through the list of channels and free items without the copyID.
3956     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
3957 #endif
3958 
3959     /*
3960      * PASS 2: free the items themselves.
3961      */
3962     dict_free_items(copyID);
3963     list_free_items(copyID);
3964 
3965 #ifdef FEAT_JOB_CHANNEL
3966     // Go through the list of jobs and free items without the copyID. This
3967     // must happen before doing channels, because jobs refer to channels, but
3968     // the reference from the channel to the job isn't tracked.
3969     free_unused_jobs(copyID, COPYID_MASK);
3970 
3971     // Go through the list of channels and free items without the copyID.
3972     free_unused_channels(copyID, COPYID_MASK);
3973 #endif
3974 
3975     in_free_unref_items = FALSE;
3976 
3977     return did_free;
3978 }
3979 
3980 /*
3981  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
3982  * "list_stack" is used to add lists to be marked.  Can be NULL.
3983  *
3984  * Returns TRUE if setting references failed somehow.
3985  */
3986     int
3987 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
3988 {
3989     int		todo;
3990     int		abort = FALSE;
3991     hashitem_T	*hi;
3992     hashtab_T	*cur_ht;
3993     ht_stack_T	*ht_stack = NULL;
3994     ht_stack_T	*tempitem;
3995 
3996     cur_ht = ht;
3997     for (;;)
3998     {
3999 	if (!abort)
4000 	{
4001 	    // Mark each item in the hashtab.  If the item contains a hashtab
4002 	    // it is added to ht_stack, if it contains a list it is added to
4003 	    // list_stack.
4004 	    todo = (int)cur_ht->ht_used;
4005 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4006 		if (!HASHITEM_EMPTY(hi))
4007 		{
4008 		    --todo;
4009 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4010 						       &ht_stack, list_stack);
4011 		}
4012 	}
4013 
4014 	if (ht_stack == NULL)
4015 	    break;
4016 
4017 	// take an item from the stack
4018 	cur_ht = ht_stack->ht;
4019 	tempitem = ht_stack;
4020 	ht_stack = ht_stack->prev;
4021 	free(tempitem);
4022     }
4023 
4024     return abort;
4025 }
4026 
4027 /*
4028  * Mark a dict and its items with "copyID".
4029  * Returns TRUE if setting references failed somehow.
4030  */
4031     int
4032 set_ref_in_dict(dict_T *d, int copyID)
4033 {
4034     if (d != NULL && d->dv_copyID != copyID)
4035     {
4036 	d->dv_copyID = copyID;
4037 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4038     }
4039     return FALSE;
4040 }
4041 
4042 /*
4043  * Mark a list and its items with "copyID".
4044  * Returns TRUE if setting references failed somehow.
4045  */
4046     int
4047 set_ref_in_list(list_T *ll, int copyID)
4048 {
4049     if (ll != NULL && ll->lv_copyID != copyID)
4050     {
4051 	ll->lv_copyID = copyID;
4052 	return set_ref_in_list_items(ll, copyID, NULL);
4053     }
4054     return FALSE;
4055 }
4056 
4057 /*
4058  * Mark all lists and dicts referenced through list "l" with "copyID".
4059  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4060  *
4061  * Returns TRUE if setting references failed somehow.
4062  */
4063     int
4064 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4065 {
4066     listitem_T	 *li;
4067     int		 abort = FALSE;
4068     list_T	 *cur_l;
4069     list_stack_T *list_stack = NULL;
4070     list_stack_T *tempitem;
4071 
4072     cur_l = l;
4073     for (;;)
4074     {
4075 	if (!abort && cur_l->lv_first != &range_list_item)
4076 	    // Mark each item in the list.  If the item contains a hashtab
4077 	    // it is added to ht_stack, if it contains a list it is added to
4078 	    // list_stack.
4079 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4080 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4081 						       ht_stack, &list_stack);
4082 	if (list_stack == NULL)
4083 	    break;
4084 
4085 	// take an item from the stack
4086 	cur_l = list_stack->list;
4087 	tempitem = list_stack;
4088 	list_stack = list_stack->prev;
4089 	free(tempitem);
4090     }
4091 
4092     return abort;
4093 }
4094 
4095 /*
4096  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4097  * "list_stack" is used to add lists to be marked.  Can be NULL.
4098  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4099  *
4100  * Returns TRUE if setting references failed somehow.
4101  */
4102     int
4103 set_ref_in_item(
4104     typval_T	    *tv,
4105     int		    copyID,
4106     ht_stack_T	    **ht_stack,
4107     list_stack_T    **list_stack)
4108 {
4109     int		abort = FALSE;
4110 
4111     if (tv->v_type == VAR_DICT)
4112     {
4113 	dict_T	*dd = tv->vval.v_dict;
4114 
4115 	if (dd != NULL && dd->dv_copyID != copyID)
4116 	{
4117 	    // Didn't see this dict yet.
4118 	    dd->dv_copyID = copyID;
4119 	    if (ht_stack == NULL)
4120 	    {
4121 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4122 	    }
4123 	    else
4124 	    {
4125 		ht_stack_T *newitem = (ht_stack_T*)malloc(sizeof(ht_stack_T));
4126 		if (newitem == NULL)
4127 		    abort = TRUE;
4128 		else
4129 		{
4130 		    newitem->ht = &dd->dv_hashtab;
4131 		    newitem->prev = *ht_stack;
4132 		    *ht_stack = newitem;
4133 		}
4134 	    }
4135 	}
4136     }
4137     else if (tv->v_type == VAR_LIST)
4138     {
4139 	list_T	*ll = tv->vval.v_list;
4140 
4141 	if (ll != NULL && ll->lv_copyID != copyID)
4142 	{
4143 	    // Didn't see this list yet.
4144 	    ll->lv_copyID = copyID;
4145 	    if (list_stack == NULL)
4146 	    {
4147 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4148 	    }
4149 	    else
4150 	    {
4151 		list_stack_T *newitem = (list_stack_T*)malloc(
4152 							sizeof(list_stack_T));
4153 		if (newitem == NULL)
4154 		    abort = TRUE;
4155 		else
4156 		{
4157 		    newitem->list = ll;
4158 		    newitem->prev = *list_stack;
4159 		    *list_stack = newitem;
4160 		}
4161 	    }
4162 	}
4163     }
4164     else if (tv->v_type == VAR_FUNC)
4165     {
4166 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4167     }
4168     else if (tv->v_type == VAR_PARTIAL)
4169     {
4170 	partial_T	*pt = tv->vval.v_partial;
4171 	int		i;
4172 
4173 	if (pt != NULL && pt->pt_copyID != copyID)
4174 	{
4175 	    // Didn't see this partial yet.
4176 	    pt->pt_copyID = copyID;
4177 
4178 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4179 
4180 	    if (pt->pt_dict != NULL)
4181 	    {
4182 		typval_T dtv;
4183 
4184 		dtv.v_type = VAR_DICT;
4185 		dtv.vval.v_dict = pt->pt_dict;
4186 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4187 	    }
4188 
4189 	    for (i = 0; i < pt->pt_argc; ++i)
4190 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4191 							ht_stack, list_stack);
4192 	    if (pt->pt_funcstack != NULL)
4193 	    {
4194 		typval_T    *stack = pt->pt_funcstack->fs_ga.ga_data;
4195 
4196 		for (i = 0; i < pt->pt_funcstack->fs_ga.ga_len; ++i)
4197 		    abort = abort || set_ref_in_item(stack + i, copyID,
4198 							 ht_stack, list_stack);
4199 	    }
4200 
4201 	}
4202     }
4203 #ifdef FEAT_JOB_CHANNEL
4204     else if (tv->v_type == VAR_JOB)
4205     {
4206 	job_T	    *job = tv->vval.v_job;
4207 	typval_T    dtv;
4208 
4209 	if (job != NULL && job->jv_copyID != copyID)
4210 	{
4211 	    job->jv_copyID = copyID;
4212 	    if (job->jv_channel != NULL)
4213 	    {
4214 		dtv.v_type = VAR_CHANNEL;
4215 		dtv.vval.v_channel = job->jv_channel;
4216 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4217 	    }
4218 	    if (job->jv_exit_cb.cb_partial != NULL)
4219 	    {
4220 		dtv.v_type = VAR_PARTIAL;
4221 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4222 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4223 	    }
4224 	}
4225     }
4226     else if (tv->v_type == VAR_CHANNEL)
4227     {
4228 	channel_T   *ch =tv->vval.v_channel;
4229 	ch_part_T   part;
4230 	typval_T    dtv;
4231 	jsonq_T	    *jq;
4232 	cbq_T	    *cq;
4233 
4234 	if (ch != NULL && ch->ch_copyID != copyID)
4235 	{
4236 	    ch->ch_copyID = copyID;
4237 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4238 	    {
4239 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4240 							     jq = jq->jq_next)
4241 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4242 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4243 							     cq = cq->cq_next)
4244 		    if (cq->cq_callback.cb_partial != NULL)
4245 		    {
4246 			dtv.v_type = VAR_PARTIAL;
4247 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4248 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4249 		    }
4250 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4251 		{
4252 		    dtv.v_type = VAR_PARTIAL;
4253 		    dtv.vval.v_partial =
4254 				      ch->ch_part[part].ch_callback.cb_partial;
4255 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4256 		}
4257 	    }
4258 	    if (ch->ch_callback.cb_partial != NULL)
4259 	    {
4260 		dtv.v_type = VAR_PARTIAL;
4261 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4262 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4263 	    }
4264 	    if (ch->ch_close_cb.cb_partial != NULL)
4265 	    {
4266 		dtv.v_type = VAR_PARTIAL;
4267 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4268 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4269 	    }
4270 	}
4271     }
4272 #endif
4273     return abort;
4274 }
4275 
4276 /*
4277  * Return a string with the string representation of a variable.
4278  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4279  * "numbuf" is used for a number.
4280  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4281  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4282  * stings as "string()", otherwise does not put quotes around strings, as
4283  * ":echo" displays values.
4284  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4285  * are replaced with "...".
4286  * May return NULL.
4287  */
4288     char_u *
4289 echo_string_core(
4290     typval_T	*tv,
4291     char_u	**tofree,
4292     char_u	*numbuf,
4293     int		copyID,
4294     int		echo_style,
4295     int		restore_copyID,
4296     int		composite_val)
4297 {
4298     static int	recurse = 0;
4299     char_u	*r = NULL;
4300 
4301     if (recurse >= DICT_MAXNEST)
4302     {
4303 	if (!did_echo_string_emsg)
4304 	{
4305 	    // Only give this message once for a recursive call to avoid
4306 	    // flooding the user with errors.  And stop iterating over lists
4307 	    // and dicts.
4308 	    did_echo_string_emsg = TRUE;
4309 	    emsg(_("E724: variable nested too deep for displaying"));
4310 	}
4311 	*tofree = NULL;
4312 	return (char_u *)"{E724}";
4313     }
4314     ++recurse;
4315 
4316     switch (tv->v_type)
4317     {
4318 	case VAR_STRING:
4319 	    if (echo_style && !composite_val)
4320 	    {
4321 		*tofree = NULL;
4322 		r = tv->vval.v_string;
4323 		if (r == NULL)
4324 		    r = (char_u *)"";
4325 	    }
4326 	    else
4327 	    {
4328 		*tofree = string_quote(tv->vval.v_string, FALSE);
4329 		r = *tofree;
4330 	    }
4331 	    break;
4332 
4333 	case VAR_FUNC:
4334 	    if (echo_style)
4335 	    {
4336 		*tofree = NULL;
4337 		r = tv->vval.v_string;
4338 	    }
4339 	    else
4340 	    {
4341 		*tofree = string_quote(tv->vval.v_string, TRUE);
4342 		r = *tofree;
4343 	    }
4344 	    break;
4345 
4346 	case VAR_PARTIAL:
4347 	    {
4348 		partial_T   *pt = tv->vval.v_partial;
4349 		char_u	    *fname = string_quote(pt == NULL ? NULL
4350 						    : partial_name(pt), FALSE);
4351 		garray_T    ga;
4352 		int	    i;
4353 		char_u	    *tf;
4354 
4355 		ga_init2(&ga, 1, 100);
4356 		ga_concat(&ga, (char_u *)"function(");
4357 		if (fname != NULL)
4358 		{
4359 		    ga_concat(&ga, fname);
4360 		    vim_free(fname);
4361 		}
4362 		if (pt != NULL && pt->pt_argc > 0)
4363 		{
4364 		    ga_concat(&ga, (char_u *)", [");
4365 		    for (i = 0; i < pt->pt_argc; ++i)
4366 		    {
4367 			if (i > 0)
4368 			    ga_concat(&ga, (char_u *)", ");
4369 			ga_concat(&ga,
4370 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
4371 			vim_free(tf);
4372 		    }
4373 		    ga_concat(&ga, (char_u *)"]");
4374 		}
4375 		if (pt != NULL && pt->pt_dict != NULL)
4376 		{
4377 		    typval_T dtv;
4378 
4379 		    ga_concat(&ga, (char_u *)", ");
4380 		    dtv.v_type = VAR_DICT;
4381 		    dtv.vval.v_dict = pt->pt_dict;
4382 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
4383 		    vim_free(tf);
4384 		}
4385 		ga_concat(&ga, (char_u *)")");
4386 
4387 		*tofree = ga.ga_data;
4388 		r = *tofree;
4389 		break;
4390 	    }
4391 
4392 	case VAR_BLOB:
4393 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
4394 	    break;
4395 
4396 	case VAR_LIST:
4397 	    if (tv->vval.v_list == NULL)
4398 	    {
4399 		// NULL list is equivalent to empty list.
4400 		*tofree = NULL;
4401 		r = (char_u *)"[]";
4402 	    }
4403 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
4404 		    && tv->vval.v_list->lv_len > 0)
4405 	    {
4406 		*tofree = NULL;
4407 		r = (char_u *)"[...]";
4408 	    }
4409 	    else
4410 	    {
4411 		int old_copyID = tv->vval.v_list->lv_copyID;
4412 
4413 		tv->vval.v_list->lv_copyID = copyID;
4414 		*tofree = list2string(tv, copyID, restore_copyID);
4415 		if (restore_copyID)
4416 		    tv->vval.v_list->lv_copyID = old_copyID;
4417 		r = *tofree;
4418 	    }
4419 	    break;
4420 
4421 	case VAR_DICT:
4422 	    if (tv->vval.v_dict == NULL)
4423 	    {
4424 		// NULL dict is equivalent to empty dict.
4425 		*tofree = NULL;
4426 		r = (char_u *)"{}";
4427 	    }
4428 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
4429 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
4430 	    {
4431 		*tofree = NULL;
4432 		r = (char_u *)"{...}";
4433 	    }
4434 	    else
4435 	    {
4436 		int old_copyID = tv->vval.v_dict->dv_copyID;
4437 
4438 		tv->vval.v_dict->dv_copyID = copyID;
4439 		*tofree = dict2string(tv, copyID, restore_copyID);
4440 		if (restore_copyID)
4441 		    tv->vval.v_dict->dv_copyID = old_copyID;
4442 		r = *tofree;
4443 	    }
4444 	    break;
4445 
4446 	case VAR_NUMBER:
4447 	case VAR_UNKNOWN:
4448 	case VAR_ANY:
4449 	case VAR_VOID:
4450 	    *tofree = NULL;
4451 	    r = tv_get_string_buf(tv, numbuf);
4452 	    break;
4453 
4454 	case VAR_JOB:
4455 	case VAR_CHANNEL:
4456 	    *tofree = NULL;
4457 	    r = tv_get_string_buf(tv, numbuf);
4458 	    if (composite_val)
4459 	    {
4460 		*tofree = string_quote(r, FALSE);
4461 		r = *tofree;
4462 	    }
4463 	    break;
4464 
4465 	case VAR_FLOAT:
4466 #ifdef FEAT_FLOAT
4467 	    *tofree = NULL;
4468 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
4469 	    r = numbuf;
4470 	    break;
4471 #endif
4472 
4473 	case VAR_BOOL:
4474 	case VAR_SPECIAL:
4475 	    *tofree = NULL;
4476 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
4477 	    break;
4478     }
4479 
4480     if (--recurse == 0)
4481 	did_echo_string_emsg = FALSE;
4482     return r;
4483 }
4484 
4485 /*
4486  * Return a string with the string representation of a variable.
4487  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4488  * "numbuf" is used for a number.
4489  * Does not put quotes around strings, as ":echo" displays values.
4490  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4491  * May return NULL.
4492  */
4493     char_u *
4494 echo_string(
4495     typval_T	*tv,
4496     char_u	**tofree,
4497     char_u	*numbuf,
4498     int		copyID)
4499 {
4500     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
4501 }
4502 
4503 /*
4504  * Return string "str" in ' quotes, doubling ' characters.
4505  * If "str" is NULL an empty string is assumed.
4506  * If "function" is TRUE make it function('string').
4507  */
4508     char_u *
4509 string_quote(char_u *str, int function)
4510 {
4511     unsigned	len;
4512     char_u	*p, *r, *s;
4513 
4514     len = (function ? 13 : 3);
4515     if (str != NULL)
4516     {
4517 	len += (unsigned)STRLEN(str);
4518 	for (p = str; *p != NUL; MB_PTR_ADV(p))
4519 	    if (*p == '\'')
4520 		++len;
4521     }
4522     s = r = alloc(len);
4523     if (r != NULL)
4524     {
4525 	if (function)
4526 	{
4527 	    STRCPY(r, "function('");
4528 	    r += 10;
4529 	}
4530 	else
4531 	    *r++ = '\'';
4532 	if (str != NULL)
4533 	    for (p = str; *p != NUL; )
4534 	    {
4535 		if (*p == '\'')
4536 		    *r++ = '\'';
4537 		MB_COPY_CHAR(p, r);
4538 	    }
4539 	*r++ = '\'';
4540 	if (function)
4541 	    *r++ = ')';
4542 	*r++ = NUL;
4543     }
4544     return s;
4545 }
4546 
4547 #if defined(FEAT_FLOAT) || defined(PROTO)
4548 /*
4549  * Convert the string "text" to a floating point number.
4550  * This uses strtod().  setlocale(LC_NUMERIC, "C") has been used to make sure
4551  * this always uses a decimal point.
4552  * Returns the length of the text that was consumed.
4553  */
4554     int
4555 string2float(
4556     char_u	*text,
4557     float_T	*value)	    // result stored here
4558 {
4559     char	*s = (char *)text;
4560     float_T	f;
4561 
4562     // MS-Windows does not deal with "inf" and "nan" properly.
4563     if (STRNICMP(text, "inf", 3) == 0)
4564     {
4565 	*value = INFINITY;
4566 	return 3;
4567     }
4568     if (STRNICMP(text, "-inf", 3) == 0)
4569     {
4570 	*value = -INFINITY;
4571 	return 4;
4572     }
4573     if (STRNICMP(text, "nan", 3) == 0)
4574     {
4575 	*value = NAN;
4576 	return 3;
4577     }
4578     f = strtod(s, &s);
4579     *value = f;
4580     return (int)((char_u *)s - text);
4581 }
4582 #endif
4583 
4584 /*
4585  * Translate a String variable into a position.
4586  * Returns NULL when there is an error.
4587  */
4588     pos_T *
4589 var2fpos(
4590     typval_T	*varp,
4591     int		dollar_lnum,	// TRUE when $ is last line
4592     int		*fnum)		// set to fnum for '0, 'A, etc.
4593 {
4594     char_u		*name;
4595     static pos_T	pos;
4596     pos_T		*pp;
4597 
4598     // Argument can be [lnum, col, coladd].
4599     if (varp->v_type == VAR_LIST)
4600     {
4601 	list_T		*l;
4602 	int		len;
4603 	int		error = FALSE;
4604 	listitem_T	*li;
4605 
4606 	l = varp->vval.v_list;
4607 	if (l == NULL)
4608 	    return NULL;
4609 
4610 	// Get the line number
4611 	pos.lnum = list_find_nr(l, 0L, &error);
4612 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
4613 	    return NULL;	// invalid line number
4614 
4615 	// Get the column number
4616 	pos.col = list_find_nr(l, 1L, &error);
4617 	if (error)
4618 	    return NULL;
4619 	len = (long)STRLEN(ml_get(pos.lnum));
4620 
4621 	// We accept "$" for the column number: last column.
4622 	li = list_find(l, 1L);
4623 	if (li != NULL && li->li_tv.v_type == VAR_STRING
4624 		&& li->li_tv.vval.v_string != NULL
4625 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
4626 	    pos.col = len + 1;
4627 
4628 	// Accept a position up to the NUL after the line.
4629 	if (pos.col == 0 || (int)pos.col > len + 1)
4630 	    return NULL;	// invalid column number
4631 	--pos.col;
4632 
4633 	// Get the virtual offset.  Defaults to zero.
4634 	pos.coladd = list_find_nr(l, 2L, &error);
4635 	if (error)
4636 	    pos.coladd = 0;
4637 
4638 	return &pos;
4639     }
4640 
4641     name = tv_get_string_chk(varp);
4642     if (name == NULL)
4643 	return NULL;
4644     if (name[0] == '.')				// cursor
4645 	return &curwin->w_cursor;
4646     if (name[0] == 'v' && name[1] == NUL)	// Visual start
4647     {
4648 	if (VIsual_active)
4649 	    return &VIsual;
4650 	return &curwin->w_cursor;
4651     }
4652     if (name[0] == '\'')			// mark
4653     {
4654 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
4655 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
4656 	    return NULL;
4657 	return pp;
4658     }
4659 
4660     pos.coladd = 0;
4661 
4662     if (name[0] == 'w' && dollar_lnum)
4663     {
4664 	pos.col = 0;
4665 	if (name[1] == '0')		// "w0": first visible line
4666 	{
4667 	    update_topline();
4668 	    // In silent Ex mode topline is zero, but that's not a valid line
4669 	    // number; use one instead.
4670 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
4671 	    return &pos;
4672 	}
4673 	else if (name[1] == '$')	// "w$": last visible line
4674 	{
4675 	    validate_botline();
4676 	    // In silent Ex mode botline is zero, return zero then.
4677 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
4678 	    return &pos;
4679 	}
4680     }
4681     else if (name[0] == '$')		// last column or line
4682     {
4683 	if (dollar_lnum)
4684 	{
4685 	    pos.lnum = curbuf->b_ml.ml_line_count;
4686 	    pos.col = 0;
4687 	}
4688 	else
4689 	{
4690 	    pos.lnum = curwin->w_cursor.lnum;
4691 	    pos.col = (colnr_T)STRLEN(ml_get_curline());
4692 	}
4693 	return &pos;
4694     }
4695     return NULL;
4696 }
4697 
4698 /*
4699  * Convert list in "arg" into a position and optional file number.
4700  * When "fnump" is NULL there is no file number, only 3 items.
4701  * Note that the column is passed on as-is, the caller may want to decrement
4702  * it to use 1 for the first column.
4703  * Return FAIL when conversion is not possible, doesn't check the position for
4704  * validity.
4705  */
4706     int
4707 list2fpos(
4708     typval_T	*arg,
4709     pos_T	*posp,
4710     int		*fnump,
4711     colnr_T	*curswantp)
4712 {
4713     list_T	*l = arg->vval.v_list;
4714     long	i = 0;
4715     long	n;
4716 
4717     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
4718     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
4719     if (arg->v_type != VAR_LIST
4720 	    || l == NULL
4721 	    || l->lv_len < (fnump == NULL ? 2 : 3)
4722 	    || l->lv_len > (fnump == NULL ? 4 : 5))
4723 	return FAIL;
4724 
4725     if (fnump != NULL)
4726     {
4727 	n = list_find_nr(l, i++, NULL);	// fnum
4728 	if (n < 0)
4729 	    return FAIL;
4730 	if (n == 0)
4731 	    n = curbuf->b_fnum;		// current buffer
4732 	*fnump = n;
4733     }
4734 
4735     n = list_find_nr(l, i++, NULL);	// lnum
4736     if (n < 0)
4737 	return FAIL;
4738     posp->lnum = n;
4739 
4740     n = list_find_nr(l, i++, NULL);	// col
4741     if (n < 0)
4742 	return FAIL;
4743     posp->col = n;
4744 
4745     n = list_find_nr(l, i, NULL);	// off
4746     if (n < 0)
4747 	posp->coladd = 0;
4748     else
4749 	posp->coladd = n;
4750 
4751     if (curswantp != NULL)
4752 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
4753 
4754     return OK;
4755 }
4756 
4757 /*
4758  * Get the length of an environment variable name.
4759  * Advance "arg" to the first character after the name.
4760  * Return 0 for error.
4761  */
4762     int
4763 get_env_len(char_u **arg)
4764 {
4765     char_u	*p;
4766     int		len;
4767 
4768     for (p = *arg; vim_isIDc(*p); ++p)
4769 	;
4770     if (p == *arg)	    // no name found
4771 	return 0;
4772 
4773     len = (int)(p - *arg);
4774     *arg = p;
4775     return len;
4776 }
4777 
4778 /*
4779  * Get the length of the name of a function or internal variable.
4780  * "arg" is advanced to the first non-white character after the name.
4781  * Return 0 if something is wrong.
4782  */
4783     int
4784 get_id_len(char_u **arg)
4785 {
4786     char_u	*p;
4787     int		len;
4788 
4789     // Find the end of the name.
4790     for (p = *arg; eval_isnamec(*p); ++p)
4791     {
4792 	if (*p == ':')
4793 	{
4794 	    // "s:" is start of "s:var", but "n:" is not and can be used in
4795 	    // slice "[n:]".  Also "xx:" is not a namespace.
4796 	    len = (int)(p - *arg);
4797 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
4798 		    || len > 1)
4799 		break;
4800 	}
4801     }
4802     if (p == *arg)	    // no name found
4803 	return 0;
4804 
4805     len = (int)(p - *arg);
4806     *arg = skipwhite(p);
4807 
4808     return len;
4809 }
4810 
4811 /*
4812  * Get the length of the name of a variable or function.
4813  * Only the name is recognized, does not handle ".key" or "[idx]".
4814  * "arg" is advanced to the first non-white character after the name.
4815  * Return -1 if curly braces expansion failed.
4816  * Return 0 if something else is wrong.
4817  * If the name contains 'magic' {}'s, expand them and return the
4818  * expanded name in an allocated string via 'alias' - caller must free.
4819  */
4820     int
4821 get_name_len(
4822     char_u	**arg,
4823     char_u	**alias,
4824     int		evaluate,
4825     int		verbose)
4826 {
4827     int		len;
4828     char_u	*p;
4829     char_u	*expr_start;
4830     char_u	*expr_end;
4831 
4832     *alias = NULL;  // default to no alias
4833 
4834     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
4835 						  && (*arg)[2] == (int)KE_SNR)
4836     {
4837 	// hard coded <SNR>, already translated
4838 	*arg += 3;
4839 	return get_id_len(arg) + 3;
4840     }
4841     len = eval_fname_script(*arg);
4842     if (len > 0)
4843     {
4844 	// literal "<SID>", "s:" or "<SNR>"
4845 	*arg += len;
4846     }
4847 
4848     /*
4849      * Find the end of the name; check for {} construction.
4850      */
4851     p = find_name_end(*arg, &expr_start, &expr_end,
4852 					       len > 0 ? 0 : FNE_CHECK_START);
4853     if (expr_start != NULL)
4854     {
4855 	char_u	*temp_string;
4856 
4857 	if (!evaluate)
4858 	{
4859 	    len += (int)(p - *arg);
4860 	    *arg = skipwhite(p);
4861 	    return len;
4862 	}
4863 
4864 	/*
4865 	 * Include any <SID> etc in the expanded string:
4866 	 * Thus the -len here.
4867 	 */
4868 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
4869 	if (temp_string == NULL)
4870 	    return -1;
4871 	*alias = temp_string;
4872 	*arg = skipwhite(p);
4873 	return (int)STRLEN(temp_string);
4874     }
4875 
4876     len += get_id_len(arg);
4877     // Only give an error when there is something, otherwise it will be
4878     // reported at a higher level.
4879     if (len == 0 && verbose && **arg != NUL)
4880 	semsg(_(e_invexpr2), *arg);
4881 
4882     return len;
4883 }
4884 
4885 /*
4886  * Find the end of a variable or function name, taking care of magic braces.
4887  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
4888  * start and end of the first magic braces item.
4889  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
4890  * Return a pointer to just after the name.  Equal to "arg" if there is no
4891  * valid name.
4892  */
4893     char_u *
4894 find_name_end(
4895     char_u	*arg,
4896     char_u	**expr_start,
4897     char_u	**expr_end,
4898     int		flags)
4899 {
4900     int		mb_nest = 0;
4901     int		br_nest = 0;
4902     char_u	*p;
4903     int		len;
4904     int		vim9script = current_sctx.sc_version == SCRIPT_VERSION_VIM9;
4905 
4906     if (expr_start != NULL)
4907     {
4908 	*expr_start = NULL;
4909 	*expr_end = NULL;
4910     }
4911 
4912     // Quick check for valid starting character.
4913     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg)
4914 						&& (*arg != '{' || vim9script))
4915 	return arg;
4916 
4917     for (p = arg; *p != NUL
4918 		    && (eval_isnamec(*p)
4919 			|| (*p == '{' && !vim9script)
4920 			|| ((flags & FNE_INCL_BR) && (*p == '[' || *p == '.'))
4921 			|| mb_nest != 0
4922 			|| br_nest != 0); MB_PTR_ADV(p))
4923     {
4924 	if (*p == '\'')
4925 	{
4926 	    // skip over 'string' to avoid counting [ and ] inside it.
4927 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
4928 		;
4929 	    if (*p == NUL)
4930 		break;
4931 	}
4932 	else if (*p == '"')
4933 	{
4934 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
4935 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
4936 		if (*p == '\\' && p[1] != NUL)
4937 		    ++p;
4938 	    if (*p == NUL)
4939 		break;
4940 	}
4941 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
4942 	{
4943 	    // "s:" is start of "s:var", but "n:" is not and can be used in
4944 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
4945 	    len = (int)(p - arg);
4946 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
4947 		    || (len > 1 && p[-1] != '}'))
4948 		break;
4949 	}
4950 
4951 	if (mb_nest == 0)
4952 	{
4953 	    if (*p == '[')
4954 		++br_nest;
4955 	    else if (*p == ']')
4956 		--br_nest;
4957 	}
4958 
4959 	if (br_nest == 0 && !vim9script)
4960 	{
4961 	    if (*p == '{')
4962 	    {
4963 		mb_nest++;
4964 		if (expr_start != NULL && *expr_start == NULL)
4965 		    *expr_start = p;
4966 	    }
4967 	    else if (*p == '}')
4968 	    {
4969 		mb_nest--;
4970 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
4971 		    *expr_end = p;
4972 	    }
4973 	}
4974     }
4975 
4976     return p;
4977 }
4978 
4979 /*
4980  * Expands out the 'magic' {}'s in a variable/function name.
4981  * Note that this can call itself recursively, to deal with
4982  * constructs like foo{bar}{baz}{bam}
4983  * The four pointer arguments point to "foo{expre}ss{ion}bar"
4984  *			"in_start"      ^
4985  *			"expr_start"	   ^
4986  *			"expr_end"		 ^
4987  *			"in_end"			    ^
4988  *
4989  * Returns a new allocated string, which the caller must free.
4990  * Returns NULL for failure.
4991  */
4992     static char_u *
4993 make_expanded_name(
4994     char_u	*in_start,
4995     char_u	*expr_start,
4996     char_u	*expr_end,
4997     char_u	*in_end)
4998 {
4999     char_u	c1;
5000     char_u	*retval = NULL;
5001     char_u	*temp_result;
5002 
5003     if (expr_end == NULL || in_end == NULL)
5004 	return NULL;
5005     *expr_start	= NUL;
5006     *expr_end = NUL;
5007     c1 = *in_end;
5008     *in_end = NUL;
5009 
5010     temp_result = eval_to_string(expr_start + 1, FALSE);
5011     if (temp_result != NULL)
5012     {
5013 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5014 						   + (in_end - expr_end) + 1);
5015 	if (retval != NULL)
5016 	{
5017 	    STRCPY(retval, in_start);
5018 	    STRCAT(retval, temp_result);
5019 	    STRCAT(retval, expr_end + 1);
5020 	}
5021     }
5022     vim_free(temp_result);
5023 
5024     *in_end = c1;		// put char back for error messages
5025     *expr_start = '{';
5026     *expr_end = '}';
5027 
5028     if (retval != NULL)
5029     {
5030 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5031 	if (expr_start != NULL)
5032 	{
5033 	    // Further expansion!
5034 	    temp_result = make_expanded_name(retval, expr_start,
5035 						       expr_end, temp_result);
5036 	    vim_free(retval);
5037 	    retval = temp_result;
5038 	}
5039     }
5040 
5041     return retval;
5042 }
5043 
5044 /*
5045  * Return TRUE if character "c" can be used in a variable or function name.
5046  * Does not include '{' or '}' for magic braces.
5047  */
5048     int
5049 eval_isnamec(int c)
5050 {
5051     return (ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR);
5052 }
5053 
5054 /*
5055  * Return TRUE if character "c" can be used as the first character in a
5056  * variable or function name (excluding '{' and '}').
5057  */
5058     int
5059 eval_isnamec1(int c)
5060 {
5061     return (ASCII_ISALPHA(c) || c == '_');
5062 }
5063 
5064 /*
5065  * Handle:
5066  * - expr[expr], expr[expr:expr] subscript
5067  * - ".name" lookup
5068  * - function call with Funcref variable: func(expr)
5069  * - method call: var->method()
5070  *
5071  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5072  */
5073     int
5074 handle_subscript(
5075     char_u	**arg,
5076     typval_T	*rettv,
5077     evalarg_T	*evalarg,
5078     int		verbose)	// give error messages
5079 {
5080     int		evaluate = evalarg != NULL
5081 				      && (evalarg->eval_flags & EVAL_EVALUATE);
5082     int		ret = OK;
5083     dict_T	*selfdict = NULL;
5084     int		check_white = TRUE;
5085     int		getnext;
5086     char_u	*p;
5087 
5088     while (ret == OK)
5089     {
5090 	// When at the end of the line and ".name" or "->{" or "->X" follows in
5091 	// the next line then consume the line break.
5092 	p = eval_next_non_blank(*arg, evalarg, &getnext);
5093 	if (getnext
5094 	    && ((rettv->v_type == VAR_DICT && *p == '.'
5095 						       && ASCII_ISALPHA(p[1]))
5096 		|| (*p == '-' && p[1] == '>'
5097 				     && (p[2] == '{' || ASCII_ISALPHA(p[2])))))
5098 	{
5099 	    *arg = eval_next_line(evalarg);
5100 	    check_white = FALSE;
5101 	}
5102 
5103 	if ((**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5104 			    || rettv->v_type == VAR_PARTIAL))
5105 		    && (!check_white || !VIM_ISWHITE(*(*arg - 1))))
5106 	{
5107 	    ret = call_func_rettv(arg, evalarg, rettv, evaluate,
5108 							       selfdict, NULL);
5109 
5110 	    // Stop the expression evaluation when immediately aborting on
5111 	    // error, or when an interrupt occurred or an exception was thrown
5112 	    // but not caught.
5113 	    if (aborting())
5114 	    {
5115 		if (ret == OK)
5116 		    clear_tv(rettv);
5117 		ret = FAIL;
5118 	    }
5119 	    dict_unref(selfdict);
5120 	    selfdict = NULL;
5121 	}
5122 	else if (**arg == '-' && (*arg)[1] == '>')
5123 	{
5124 	    if (ret == OK)
5125 	    {
5126 		if ((*arg)[2] == '{')
5127 		    // expr->{lambda}()
5128 		    ret = eval_lambda(arg, rettv, evalarg, verbose);
5129 		else
5130 		    // expr->name()
5131 		    ret = eval_method(arg, rettv, evalarg, verbose);
5132 	    }
5133 	}
5134 	// "." is ".name" lookup when we found a dict or when evaluating and
5135 	// scriptversion is at least 2, where string concatenation is "..".
5136 	else if (**arg == '['
5137 		|| (**arg == '.' && (rettv->v_type == VAR_DICT
5138 			|| (!evaluate
5139 			    && (*arg)[1] != '.'
5140 			    && current_sctx.sc_version >= 2))))
5141 	{
5142 	    dict_unref(selfdict);
5143 	    if (rettv->v_type == VAR_DICT)
5144 	    {
5145 		selfdict = rettv->vval.v_dict;
5146 		if (selfdict != NULL)
5147 		    ++selfdict->dv_refcount;
5148 	    }
5149 	    else
5150 		selfdict = NULL;
5151 	    if (eval_index(arg, rettv, evalarg, verbose) == FAIL)
5152 	    {
5153 		clear_tv(rettv);
5154 		ret = FAIL;
5155 	    }
5156 	}
5157 	else
5158 	    break;
5159     }
5160 
5161     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5162     // Don't do this when "Func" is already a partial that was bound
5163     // explicitly (pt_auto is FALSE).
5164     if (selfdict != NULL
5165 	    && (rettv->v_type == VAR_FUNC
5166 		|| (rettv->v_type == VAR_PARTIAL
5167 		    && (rettv->vval.v_partial->pt_auto
5168 			|| rettv->vval.v_partial->pt_dict == NULL))))
5169 	selfdict = make_partial(selfdict, rettv);
5170 
5171     dict_unref(selfdict);
5172     return ret;
5173 }
5174 
5175 /*
5176  * Make a copy of an item.
5177  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5178  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5179  * reference to an already copied list/dict can be used.
5180  * Returns FAIL or OK.
5181  */
5182     int
5183 item_copy(
5184     typval_T	*from,
5185     typval_T	*to,
5186     int		deep,
5187     int		copyID)
5188 {
5189     static int	recurse = 0;
5190     int		ret = OK;
5191 
5192     if (recurse >= DICT_MAXNEST)
5193     {
5194 	emsg(_("E698: variable nested too deep for making a copy"));
5195 	return FAIL;
5196     }
5197     ++recurse;
5198 
5199     switch (from->v_type)
5200     {
5201 	case VAR_NUMBER:
5202 	case VAR_FLOAT:
5203 	case VAR_STRING:
5204 	case VAR_FUNC:
5205 	case VAR_PARTIAL:
5206 	case VAR_BOOL:
5207 	case VAR_SPECIAL:
5208 	case VAR_JOB:
5209 	case VAR_CHANNEL:
5210 	    copy_tv(from, to);
5211 	    break;
5212 	case VAR_LIST:
5213 	    to->v_type = VAR_LIST;
5214 	    to->v_lock = 0;
5215 	    if (from->vval.v_list == NULL)
5216 		to->vval.v_list = NULL;
5217 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
5218 	    {
5219 		// use the copy made earlier
5220 		to->vval.v_list = from->vval.v_list->lv_copylist;
5221 		++to->vval.v_list->lv_refcount;
5222 	    }
5223 	    else
5224 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
5225 	    if (to->vval.v_list == NULL)
5226 		ret = FAIL;
5227 	    break;
5228 	case VAR_BLOB:
5229 	    ret = blob_copy(from->vval.v_blob, to);
5230 	    break;
5231 	case VAR_DICT:
5232 	    to->v_type = VAR_DICT;
5233 	    to->v_lock = 0;
5234 	    if (from->vval.v_dict == NULL)
5235 		to->vval.v_dict = NULL;
5236 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
5237 	    {
5238 		// use the copy made earlier
5239 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
5240 		++to->vval.v_dict->dv_refcount;
5241 	    }
5242 	    else
5243 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
5244 	    if (to->vval.v_dict == NULL)
5245 		ret = FAIL;
5246 	    break;
5247 	case VAR_UNKNOWN:
5248 	case VAR_ANY:
5249 	case VAR_VOID:
5250 	    internal_error_no_abort("item_copy(UNKNOWN)");
5251 	    ret = FAIL;
5252     }
5253     --recurse;
5254     return ret;
5255 }
5256 
5257     void
5258 echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr)
5259 {
5260     char_u	*tofree;
5261     char_u	numbuf[NUMBUFLEN];
5262     char_u	*p = echo_string(rettv, &tofree, numbuf, get_copyID());
5263 
5264     if (*atstart)
5265     {
5266 	*atstart = FALSE;
5267 	// Call msg_start() after eval1(), evaluating the expression
5268 	// may cause a message to appear.
5269 	if (with_space)
5270 	{
5271 	    // Mark the saved text as finishing the line, so that what
5272 	    // follows is displayed on a new line when scrolling back
5273 	    // at the more prompt.
5274 	    msg_sb_eol();
5275 	    msg_start();
5276 	}
5277     }
5278     else if (with_space)
5279 	msg_puts_attr(" ", echo_attr);
5280 
5281     if (p != NULL)
5282 	for ( ; *p != NUL && !got_int; ++p)
5283 	{
5284 	    if (*p == '\n' || *p == '\r' || *p == TAB)
5285 	    {
5286 		if (*p != TAB && *needclr)
5287 		{
5288 		    // remove any text still there from the command
5289 		    msg_clr_eos();
5290 		    *needclr = FALSE;
5291 		}
5292 		msg_putchar_attr(*p, echo_attr);
5293 	    }
5294 	    else
5295 	    {
5296 		if (has_mbyte)
5297 		{
5298 		    int i = (*mb_ptr2len)(p);
5299 
5300 		    (void)msg_outtrans_len_attr(p, i, echo_attr);
5301 		    p += i - 1;
5302 		}
5303 		else
5304 		    (void)msg_outtrans_len_attr(p, 1, echo_attr);
5305 	    }
5306 	}
5307     vim_free(tofree);
5308 }
5309 
5310 /*
5311  * ":echo expr1 ..."	print each argument separated with a space, add a
5312  *			newline at the end.
5313  * ":echon expr1 ..."	print each argument plain.
5314  */
5315     void
5316 ex_echo(exarg_T *eap)
5317 {
5318     char_u	*arg = eap->arg;
5319     typval_T	rettv;
5320     char_u	*p;
5321     int		needclr = TRUE;
5322     int		atstart = TRUE;
5323     int		did_emsg_before = did_emsg;
5324     int		called_emsg_before = called_emsg;
5325     evalarg_T	evalarg;
5326 
5327     fill_evalarg_from_eap(&evalarg, eap, eap->skip);
5328 
5329     if (eap->skip)
5330 	++emsg_skip;
5331     while ((!ends_excmd2(eap->cmd, arg) || *arg == '"') && !got_int)
5332     {
5333 	// If eval1() causes an error message the text from the command may
5334 	// still need to be cleared. E.g., "echo 22,44".
5335 	need_clr_eos = needclr;
5336 
5337 	p = arg;
5338 	if (eval1(&arg, &rettv, &evalarg) == FAIL)
5339 	{
5340 	    /*
5341 	     * Report the invalid expression unless the expression evaluation
5342 	     * has been cancelled due to an aborting error, an interrupt, or an
5343 	     * exception.
5344 	     */
5345 	    if (!aborting() && did_emsg == did_emsg_before
5346 					  && called_emsg == called_emsg_before)
5347 		semsg(_(e_invexpr2), p);
5348 	    need_clr_eos = FALSE;
5349 	    break;
5350 	}
5351 	need_clr_eos = FALSE;
5352 
5353 	if (!eap->skip)
5354 	    echo_one(&rettv, eap->cmdidx == CMD_echo, &atstart, &needclr);
5355 
5356 	clear_tv(&rettv);
5357 	arg = skipwhite(arg);
5358     }
5359     eap->nextcmd = check_nextcmd(arg);
5360     clear_evalarg(&evalarg, eap);
5361 
5362     if (eap->skip)
5363 	--emsg_skip;
5364     else
5365     {
5366 	// remove text that may still be there from the command
5367 	if (needclr)
5368 	    msg_clr_eos();
5369 	if (eap->cmdidx == CMD_echo)
5370 	    msg_end();
5371     }
5372 }
5373 
5374 /*
5375  * ":echohl {name}".
5376  */
5377     void
5378 ex_echohl(exarg_T *eap)
5379 {
5380     echo_attr = syn_name2attr(eap->arg);
5381 }
5382 
5383 /*
5384  * Returns the :echo attribute
5385  */
5386     int
5387 get_echo_attr(void)
5388 {
5389     return echo_attr;
5390 }
5391 
5392 /*
5393  * ":execute expr1 ..."	execute the result of an expression.
5394  * ":echomsg expr1 ..."	Print a message
5395  * ":echoerr expr1 ..."	Print an error
5396  * Each gets spaces around each argument and a newline at the end for
5397  * echo commands
5398  */
5399     void
5400 ex_execute(exarg_T *eap)
5401 {
5402     char_u	*arg = eap->arg;
5403     typval_T	rettv;
5404     int		ret = OK;
5405     char_u	*p;
5406     garray_T	ga;
5407     int		len;
5408 
5409     ga_init2(&ga, 1, 80);
5410 
5411     if (eap->skip)
5412 	++emsg_skip;
5413     while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
5414     {
5415 	ret = eval1_emsg(&arg, &rettv, eap);
5416 	if (ret == FAIL)
5417 	    break;
5418 
5419 	if (!eap->skip)
5420 	{
5421 	    char_u   buf[NUMBUFLEN];
5422 
5423 	    if (eap->cmdidx == CMD_execute)
5424 	    {
5425 		if (rettv.v_type == VAR_CHANNEL || rettv.v_type == VAR_JOB)
5426 		{
5427 		    emsg(_(e_inval_string));
5428 		    p = NULL;
5429 		}
5430 		else
5431 		    p = tv_get_string_buf(&rettv, buf);
5432 	    }
5433 	    else
5434 		p = tv_stringify(&rettv, buf);
5435 	    if (p == NULL)
5436 	    {
5437 		clear_tv(&rettv);
5438 		ret = FAIL;
5439 		break;
5440 	    }
5441 	    len = (int)STRLEN(p);
5442 	    if (ga_grow(&ga, len + 2) == FAIL)
5443 	    {
5444 		clear_tv(&rettv);
5445 		ret = FAIL;
5446 		break;
5447 	    }
5448 	    if (ga.ga_len)
5449 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
5450 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
5451 	    ga.ga_len += len;
5452 	}
5453 
5454 	clear_tv(&rettv);
5455 	arg = skipwhite(arg);
5456     }
5457 
5458     if (ret != FAIL && ga.ga_data != NULL)
5459     {
5460 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
5461 	{
5462 	    // Mark the already saved text as finishing the line, so that what
5463 	    // follows is displayed on a new line when scrolling back at the
5464 	    // more prompt.
5465 	    msg_sb_eol();
5466 	}
5467 
5468 	if (eap->cmdidx == CMD_echomsg)
5469 	{
5470 	    msg_attr(ga.ga_data, echo_attr);
5471 	    out_flush();
5472 	}
5473 	else if (eap->cmdidx == CMD_echoerr)
5474 	{
5475 	    int		save_did_emsg = did_emsg;
5476 
5477 	    // We don't want to abort following commands, restore did_emsg.
5478 	    emsg(ga.ga_data);
5479 	    if (!force_abort)
5480 		did_emsg = save_did_emsg;
5481 	}
5482 	else if (eap->cmdidx == CMD_execute)
5483 	    do_cmdline((char_u *)ga.ga_data,
5484 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
5485     }
5486 
5487     ga_clear(&ga);
5488 
5489     if (eap->skip)
5490 	--emsg_skip;
5491 
5492     eap->nextcmd = check_nextcmd(arg);
5493 }
5494 
5495 /*
5496  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
5497  * "arg" points to the "&" or '+' when called, to "option" when returning.
5498  * Returns NULL when no option name found.  Otherwise pointer to the char
5499  * after the option name.
5500  */
5501     char_u *
5502 find_option_end(char_u **arg, int *opt_flags)
5503 {
5504     char_u	*p = *arg;
5505 
5506     ++p;
5507     if (*p == 'g' && p[1] == ':')
5508     {
5509 	*opt_flags = OPT_GLOBAL;
5510 	p += 2;
5511     }
5512     else if (*p == 'l' && p[1] == ':')
5513     {
5514 	*opt_flags = OPT_LOCAL;
5515 	p += 2;
5516     }
5517     else
5518 	*opt_flags = 0;
5519 
5520     if (!ASCII_ISALPHA(*p))
5521 	return NULL;
5522     *arg = p;
5523 
5524     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
5525 	p += 4;	    // termcap option
5526     else
5527 	while (ASCII_ISALPHA(*p))
5528 	    ++p;
5529     return p;
5530 }
5531 
5532 /*
5533  * Display script name where an item was last set.
5534  * Should only be invoked when 'verbose' is non-zero.
5535  */
5536     void
5537 last_set_msg(sctx_T script_ctx)
5538 {
5539     char_u *p;
5540 
5541     if (script_ctx.sc_sid != 0)
5542     {
5543 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
5544 	if (p != NULL)
5545 	{
5546 	    verbose_enter();
5547 	    msg_puts(_("\n\tLast set from "));
5548 	    msg_puts((char *)p);
5549 	    if (script_ctx.sc_lnum > 0)
5550 	    {
5551 		msg_puts(_(line_msg));
5552 		msg_outnum((long)script_ctx.sc_lnum);
5553 	    }
5554 	    verbose_leave();
5555 	    vim_free(p);
5556 	}
5557     }
5558 }
5559 
5560 #endif // FEAT_EVAL
5561 
5562 /*
5563  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
5564  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
5565  * "flags" can be "g" to do a global substitute.
5566  * Returns an allocated string, NULL for error.
5567  */
5568     char_u *
5569 do_string_sub(
5570     char_u	*str,
5571     char_u	*pat,
5572     char_u	*sub,
5573     typval_T	*expr,
5574     char_u	*flags)
5575 {
5576     int		sublen;
5577     regmatch_T	regmatch;
5578     int		i;
5579     int		do_all;
5580     char_u	*tail;
5581     char_u	*end;
5582     garray_T	ga;
5583     char_u	*ret;
5584     char_u	*save_cpo;
5585     char_u	*zero_width = NULL;
5586 
5587     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
5588     save_cpo = p_cpo;
5589     p_cpo = empty_option;
5590 
5591     ga_init2(&ga, 1, 200);
5592 
5593     do_all = (flags[0] == 'g');
5594 
5595     regmatch.rm_ic = p_ic;
5596     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
5597     if (regmatch.regprog != NULL)
5598     {
5599 	tail = str;
5600 	end = str + STRLEN(str);
5601 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
5602 	{
5603 	    // Skip empty match except for first match.
5604 	    if (regmatch.startp[0] == regmatch.endp[0])
5605 	    {
5606 		if (zero_width == regmatch.startp[0])
5607 		{
5608 		    // avoid getting stuck on a match with an empty string
5609 		    i = mb_ptr2len(tail);
5610 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
5611 								   (size_t)i);
5612 		    ga.ga_len += i;
5613 		    tail += i;
5614 		    continue;
5615 		}
5616 		zero_width = regmatch.startp[0];
5617 	    }
5618 
5619 	    /*
5620 	     * Get some space for a temporary buffer to do the substitution
5621 	     * into.  It will contain:
5622 	     * - The text up to where the match is.
5623 	     * - The substituted text.
5624 	     * - The text after the match.
5625 	     */
5626 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
5627 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
5628 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
5629 	    {
5630 		ga_clear(&ga);
5631 		break;
5632 	    }
5633 
5634 	    // copy the text up to where the match is
5635 	    i = (int)(regmatch.startp[0] - tail);
5636 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
5637 	    // add the substituted text
5638 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
5639 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
5640 	    ga.ga_len += i + sublen - 1;
5641 	    tail = regmatch.endp[0];
5642 	    if (*tail == NUL)
5643 		break;
5644 	    if (!do_all)
5645 		break;
5646 	}
5647 
5648 	if (ga.ga_data != NULL)
5649 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
5650 
5651 	vim_regfree(regmatch.regprog);
5652     }
5653 
5654     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
5655     ga_clear(&ga);
5656     if (p_cpo == empty_option)
5657 	p_cpo = save_cpo;
5658     else
5659 	// Darn, evaluating {sub} expression or {expr} changed the value.
5660 	free_string_option(save_cpo);
5661 
5662     return ret;
5663 }
5664