xref: /vim-8.2.3635/src/vim9type.c (revision a0122dcd)
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  * vim9type.c: handling of types
12  */
13 
14 #define USING_FLOAT_STUFF
15 #include "vim.h"
16 
17 #if defined(FEAT_EVAL) || defined(PROTO)
18 
19 #ifdef VMS
20 # include <float.h>
21 #endif
22 
23 /*
24  * Allocate memory for a type_T and add the pointer to type_gap, so that it can
25  * be easily freed later.
26  */
27     type_T *
28 get_type_ptr(garray_T *type_gap)
29 {
30     type_T *type;
31 
32     if (ga_grow(type_gap, 1) == FAIL)
33 	return NULL;
34     type = ALLOC_CLEAR_ONE(type_T);
35     if (type != NULL)
36     {
37 	((type_T **)type_gap->ga_data)[type_gap->ga_len] = type;
38 	++type_gap->ga_len;
39     }
40     return type;
41 }
42 
43     void
44 clear_type_list(garray_T *gap)
45 {
46     while (gap->ga_len > 0)
47 	vim_free(((type_T **)gap->ga_data)[--gap->ga_len]);
48     ga_clear(gap);
49 }
50 
51 /*
52  * Take a type that is using entries in a growarray and turn it into a type
53  * with allocated entries.
54  */
55     type_T *
56 alloc_type(type_T *type)
57 {
58     type_T *ret;
59 
60     if (type == NULL)
61 	return NULL;
62 
63     // A fixed type never contains allocated types, return as-is.
64     if (type->tt_flags & TTFLAG_STATIC)
65 	return type;
66 
67     ret = ALLOC_ONE(type_T);
68     *ret = *type;
69 
70     if (ret->tt_member != NULL)
71 	ret->tt_member = alloc_type(ret->tt_member);
72     if (type->tt_args != NULL)
73     {
74 	int i;
75 
76 	ret->tt_args = ALLOC_MULT(type_T *, type->tt_argcount);
77 	if (ret->tt_args != NULL)
78 	    for (i = 0; i < type->tt_argcount; ++i)
79 		ret->tt_args[i] = alloc_type(type->tt_args[i]);
80     }
81 
82     return ret;
83 }
84 
85 /*
86  * Free a type that was created with alloc_type().
87  */
88     void
89 free_type(type_T *type)
90 {
91     int i;
92 
93     if (type == NULL || (type->tt_flags & TTFLAG_STATIC))
94 	return;
95     if (type->tt_args != NULL)
96     {
97 	for (i = 0; i < type->tt_argcount; ++i)
98 	    free_type(type->tt_args[i]);
99 	vim_free(type->tt_args);
100     }
101     free_type(type->tt_member);
102     vim_free(type);
103 }
104 
105     type_T *
106 get_list_type(type_T *member_type, garray_T *type_gap)
107 {
108     type_T *type;
109 
110     // recognize commonly used types
111     if (member_type == NULL || member_type->tt_type == VAR_ANY)
112 	return &t_list_any;
113     if (member_type->tt_type == VAR_VOID
114 	    || member_type->tt_type == VAR_UNKNOWN)
115 	return &t_list_empty;
116     if (member_type->tt_type == VAR_BOOL)
117 	return &t_list_bool;
118     if (member_type->tt_type == VAR_NUMBER)
119 	return &t_list_number;
120     if (member_type->tt_type == VAR_STRING)
121 	return &t_list_string;
122 
123     // Not a common type, create a new entry.
124     type = get_type_ptr(type_gap);
125     if (type == NULL)
126 	return &t_any;
127     type->tt_type = VAR_LIST;
128     type->tt_member = member_type;
129     type->tt_argcount = 0;
130     type->tt_args = NULL;
131     return type;
132 }
133 
134     type_T *
135 get_dict_type(type_T *member_type, garray_T *type_gap)
136 {
137     type_T *type;
138 
139     // recognize commonly used types
140     if (member_type == NULL || member_type->tt_type == VAR_ANY)
141 	return &t_dict_any;
142     if (member_type->tt_type == VAR_VOID
143 	    || member_type->tt_type == VAR_UNKNOWN)
144 	return &t_dict_empty;
145     if (member_type->tt_type == VAR_BOOL)
146 	return &t_dict_bool;
147     if (member_type->tt_type == VAR_NUMBER)
148 	return &t_dict_number;
149     if (member_type->tt_type == VAR_STRING)
150 	return &t_dict_string;
151 
152     // Not a common type, create a new entry.
153     type = get_type_ptr(type_gap);
154     if (type == NULL)
155 	return &t_any;
156     type->tt_type = VAR_DICT;
157     type->tt_member = member_type;
158     type->tt_argcount = 0;
159     type->tt_args = NULL;
160     return type;
161 }
162 
163 /*
164  * Allocate a new type for a function.
165  */
166     type_T *
167 alloc_func_type(type_T *ret_type, int argcount, garray_T *type_gap)
168 {
169     type_T *type = get_type_ptr(type_gap);
170 
171     if (type == NULL)
172 	return &t_any;
173     type->tt_type = VAR_FUNC;
174     type->tt_member = ret_type;
175     type->tt_argcount = argcount;
176     type->tt_args = NULL;
177     return type;
178 }
179 
180 /*
181  * Get a function type, based on the return type "ret_type".
182  * If "argcount" is -1 or 0 a predefined type can be used.
183  * If "argcount" > 0 always create a new type, so that arguments can be added.
184  */
185     type_T *
186 get_func_type(type_T *ret_type, int argcount, garray_T *type_gap)
187 {
188     // recognize commonly used types
189     if (argcount <= 0)
190     {
191 	if (ret_type == &t_unknown)
192 	{
193 	    // (argcount == 0) is not possible
194 	    return &t_func_unknown;
195 	}
196 	if (ret_type == &t_void)
197 	{
198 	    if (argcount == 0)
199 		return &t_func_0_void;
200 	    else
201 		return &t_func_void;
202 	}
203 	if (ret_type == &t_any)
204 	{
205 	    if (argcount == 0)
206 		return &t_func_0_any;
207 	    else
208 		return &t_func_any;
209 	}
210 	if (ret_type == &t_number)
211 	{
212 	    if (argcount == 0)
213 		return &t_func_0_number;
214 	    else
215 		return &t_func_number;
216 	}
217 	if (ret_type == &t_string)
218 	{
219 	    if (argcount == 0)
220 		return &t_func_0_string;
221 	    else
222 		return &t_func_string;
223 	}
224     }
225 
226     return alloc_func_type(ret_type, argcount, type_gap);
227 }
228 
229 /*
230  * For a function type, reserve space for "argcount" argument types (including
231  * vararg).
232  */
233     int
234 func_type_add_arg_types(
235 	type_T	    *functype,
236 	int	    argcount,
237 	garray_T    *type_gap)
238 {
239     // To make it easy to free the space needed for the argument types, add the
240     // pointer to type_gap.
241     if (ga_grow(type_gap, 1) == FAIL)
242 	return FAIL;
243     functype->tt_args = ALLOC_CLEAR_MULT(type_T *, argcount);
244     if (functype->tt_args == NULL)
245 	return FAIL;
246     ((type_T **)type_gap->ga_data)[type_gap->ga_len] =
247 						     (void *)functype->tt_args;
248     ++type_gap->ga_len;
249     return OK;
250 }
251 
252 /*
253  * Get a type_T for a typval_T.
254  * "type_gap" is used to temporarily create types in.
255  */
256     static type_T *
257 typval2type_int(typval_T *tv, garray_T *type_gap)
258 {
259     type_T  *type;
260     type_T  *member_type = &t_any;
261     int	    argcount = 0;
262 
263     if (tv->v_type == VAR_NUMBER)
264 	return &t_number;
265     if (tv->v_type == VAR_BOOL)
266 	return &t_bool;
267     if (tv->v_type == VAR_STRING)
268 	return &t_string;
269 
270     if (tv->v_type == VAR_LIST)
271     {
272 	list_T	    *l = tv->vval.v_list;
273 	listitem_T  *li;
274 
275 	if (l == NULL || l->lv_first == NULL)
276 	    return &t_list_empty;
277 	if (l->lv_first == &range_list_item)
278 	    return &t_list_number;
279 
280 	// Use the common type of all members.
281 	member_type = typval2type(&l->lv_first->li_tv, type_gap);
282 	for (li = l->lv_first->li_next; li != NULL; li = li->li_next)
283 	    common_type(typval2type(&li->li_tv, type_gap),
284 					  member_type, &member_type, type_gap);
285 	return get_list_type(member_type, type_gap);
286     }
287 
288     if (tv->v_type == VAR_DICT)
289     {
290 	dict_iterator_T iter;
291 	typval_T	*value;
292 
293 	if (tv->vval.v_dict == NULL
294 				   || tv->vval.v_dict->dv_hashtab.ht_used == 0)
295 	    return &t_dict_empty;
296 
297 	// Use the common type of all values.
298 	dict_iterate_start(tv, &iter);
299 	dict_iterate_next(&iter, &value);
300 	member_type = typval2type(value, type_gap);
301 	while (dict_iterate_next(&iter, &value) != NULL)
302 	    common_type(typval2type(value, type_gap),
303 					  member_type, &member_type, type_gap);
304 	return get_dict_type(member_type, type_gap);
305     }
306 
307     if (tv->v_type == VAR_FUNC || tv->v_type == VAR_PARTIAL)
308     {
309 	char_u	*name = NULL;
310 	ufunc_T *ufunc = NULL;
311 
312 	if (tv->v_type == VAR_PARTIAL)
313 	{
314 	    if (tv->vval.v_partial->pt_func != NULL)
315 		ufunc = tv->vval.v_partial->pt_func;
316 	    else
317 		name = tv->vval.v_partial->pt_name;
318 	}
319 	else
320 	    name = tv->vval.v_string;
321 	if (name != NULL)
322 	{
323 	    int idx = find_internal_func(name);
324 
325 	    if (idx >= 0)
326 	    {
327 		// TODO: get actual arg count and types
328 		argcount = -1;
329 		member_type = internal_func_ret_type(idx, 0, NULL);
330 	    }
331 	    else
332 		ufunc = find_func(name, FALSE, NULL);
333 	}
334 	if (ufunc != NULL)
335 	{
336 	    // May need to get the argument types from default values by
337 	    // compiling the function.
338 	    if (ufunc->uf_def_status == UF_TO_BE_COMPILED
339 			    && compile_def_function(ufunc, TRUE, NULL) == FAIL)
340 		return NULL;
341 	    if (ufunc->uf_func_type == NULL)
342 		set_function_type(ufunc);
343 	    if (ufunc->uf_func_type != NULL)
344 		return ufunc->uf_func_type;
345 	}
346     }
347 
348     type = get_type_ptr(type_gap);
349     if (type == NULL)
350 	return NULL;
351     type->tt_type = tv->v_type;
352     type->tt_argcount = argcount;
353     type->tt_member = member_type;
354 
355     return type;
356 }
357 
358 /*
359  * Return TRUE if "tv" is not a bool but should be converted to bool.
360  */
361     int
362 need_convert_to_bool(type_T *type, typval_T *tv)
363 {
364     return type != NULL && type == &t_bool && tv->v_type != VAR_BOOL
365 	    && (tv->v_type == VAR_NUMBER
366 		       && (tv->vval.v_number == 0 || tv->vval.v_number == 1));
367 }
368 
369 /*
370  * Get a type_T for a typval_T.
371  * "type_list" is used to temporarily create types in.
372  */
373     type_T *
374 typval2type(typval_T *tv, garray_T *type_gap)
375 {
376     type_T *type = typval2type_int(tv, type_gap);
377 
378     if (type != NULL && type != &t_bool
379 	    && (tv->v_type == VAR_NUMBER
380 		    && (tv->vval.v_number == 0 || tv->vval.v_number == 1)))
381 	// Number 0 and 1 and expression with "&&" or "||" can also be used for
382 	// bool.
383 	type = &t_number_bool;
384     return type;
385 }
386 
387 /*
388  * Get a type_T for a typval_T, used for v: variables.
389  * "type_list" is used to temporarily create types in.
390  */
391     type_T *
392 typval2type_vimvar(typval_T *tv, garray_T *type_gap)
393 {
394     if (tv->v_type == VAR_LIST)  // e.g. for v:oldfiles
395 	return &t_list_string;
396     if (tv->v_type == VAR_DICT)  // e.g. for v:completed_item
397 	return &t_dict_any;
398     return typval2type(tv, type_gap);
399 }
400 
401 
402 /*
403  * Return FAIL if "expected" and "actual" don't match.
404  * When "argidx" > 0 it is included in the error message.
405  */
406     int
407 check_typval_type(type_T *expected, typval_T *actual_tv, int argidx)
408 {
409     garray_T	type_list;
410     type_T	*actual_type;
411     int		res = FAIL;
412 
413     ga_init2(&type_list, sizeof(type_T *), 10);
414     actual_type = typval2type(actual_tv, &type_list);
415     if (actual_type != NULL)
416 	res = check_type(expected, actual_type, TRUE, argidx);
417     clear_type_list(&type_list);
418     return res;
419 }
420 
421     void
422 type_mismatch(type_T *expected, type_T *actual)
423 {
424     arg_type_mismatch(expected, actual, 0);
425 }
426 
427     void
428 arg_type_mismatch(type_T *expected, type_T *actual, int argidx)
429 {
430     char *tofree1, *tofree2;
431     char *typename1 = type_name(expected, &tofree1);
432     char *typename2 = type_name(actual, &tofree2);
433 
434     if (argidx > 0)
435 	semsg(_(e_argument_nr_type_mismatch_expected_str_but_got_str),
436 						 argidx, typename1, typename2);
437     else
438 	semsg(_(e_type_mismatch_expected_str_but_got_str),
439 							 typename1, typename2);
440     vim_free(tofree1);
441     vim_free(tofree2);
442 }
443 
444 /*
445  * Check if the expected and actual types match.
446  * Does not allow for assigning "any" to a specific type.
447  * When "argidx" > 0 it is included in the error message.
448  */
449     int
450 check_type(type_T *expected, type_T *actual, int give_msg, int argidx)
451 {
452     int ret = OK;
453 
454     // When expected is "unknown" we accept any actual type.
455     // When expected is "any" we accept any actual type except "void".
456     if (expected->tt_type != VAR_UNKNOWN
457 	    && !(expected->tt_type == VAR_ANY && actual->tt_type != VAR_VOID))
458 
459     {
460 	// tt_type should match, except that a "partial" can be assigned to a
461 	// variable with type "func".
462 	if (!(expected->tt_type == actual->tt_type
463 		    || (expected->tt_type == VAR_FUNC
464 					   && actual->tt_type == VAR_PARTIAL)))
465 	{
466 	    if (expected->tt_type == VAR_BOOL
467 					&& (actual->tt_flags & TTFLAG_BOOL_OK))
468 		// Using number 0 or 1 for bool is OK.
469 		return OK;
470 	    if (give_msg)
471 		arg_type_mismatch(expected, actual, argidx);
472 	    return FAIL;
473 	}
474 	if (expected->tt_type == VAR_DICT || expected->tt_type == VAR_LIST)
475 	{
476 	    // "unknown" is used for an empty list or dict
477 	    if (actual->tt_member != &t_unknown)
478 		ret = check_type(expected->tt_member, actual->tt_member,
479 								     FALSE, 0);
480 	}
481 	else if (expected->tt_type == VAR_FUNC)
482 	{
483 	    // If the return type is unknown it can be anything, including
484 	    // nothing, thus there is no point in checking.
485 	    if (expected->tt_member != &t_unknown
486 					    && actual->tt_member != &t_unknown)
487 		ret = check_type(expected->tt_member, actual->tt_member,
488 								     FALSE, 0);
489 	    if (ret == OK && expected->tt_argcount != -1
490 		    && actual->tt_argcount != -1
491 		    && (actual->tt_argcount < expected->tt_min_argcount
492 			|| actual->tt_argcount > expected->tt_argcount))
493 		ret = FAIL;
494 	    if (ret == OK && expected->tt_args != NULL
495 						    && actual->tt_args != NULL)
496 	    {
497 		int i;
498 
499 		for (i = 0; i < expected->tt_argcount; ++i)
500 		    // Allow for using "any" argument type, lambda's have them.
501 		    if (actual->tt_args[i] != &t_any && check_type(
502 			    expected->tt_args[i], actual->tt_args[i], FALSE, 0)
503 								       == FAIL)
504 		    {
505 			ret = FAIL;
506 			break;
507 		    }
508 	    }
509 	}
510 	if (ret == FAIL && give_msg)
511 	    arg_type_mismatch(expected, actual, argidx);
512     }
513     return ret;
514 }
515 
516 /*
517  * Like check_type() but also allow for a runtime type check. E.g. "any" can be
518  * used for "number".
519  */
520     int
521 check_arg_type(type_T *expected, type_T *actual, int argidx)
522 {
523     if (check_type(expected, actual, FALSE, 0) == OK
524 					    || use_typecheck(actual, expected))
525 	return OK;
526     // TODO: should generate a TYPECHECK instruction.
527     return check_type(expected, actual, TRUE, argidx);
528 }
529 
530 /*
531  * Check that the arguments of "type" match "argvars[argcount]".
532  * Return OK/FAIL.
533  */
534     int
535 check_argument_types(type_T *type, typval_T *argvars, int argcount, char_u *name)
536 {
537     int	    varargs = (type->tt_flags & TTFLAG_VARARGS) ? 1 : 0;
538     int	    i;
539 
540     if (type->tt_type != VAR_FUNC && type->tt_type != VAR_PARTIAL)
541 	return OK;  // just in case
542     if (argcount < type->tt_min_argcount - varargs)
543     {
544 	semsg(_(e_toofewarg), name);
545 	return FAIL;
546     }
547     if (!varargs && type->tt_argcount >= 0 && argcount > type->tt_argcount)
548     {
549 	semsg(_(e_toomanyarg), name);
550 	return FAIL;
551     }
552     if (type->tt_args == NULL)
553 	return OK;  // cannot check
554 
555 
556     for (i = 0; i < argcount; ++i)
557     {
558 	type_T	*expected;
559 
560 	if (varargs && i >= type->tt_argcount - 1)
561 	    expected = type->tt_args[type->tt_argcount - 1]->tt_member;
562 	else
563 	    expected = type->tt_args[i];
564 	if (check_typval_type(expected, &argvars[i], i + 1) == FAIL)
565 	    return FAIL;
566     }
567     return OK;
568 }
569 
570 /*
571  * Skip over a type definition and return a pointer to just after it.
572  * When "optional" is TRUE then a leading "?" is accepted.
573  */
574     char_u *
575 skip_type(char_u *start, int optional)
576 {
577     char_u *p = start;
578 
579     if (optional && *p == '?')
580 	++p;
581     while (ASCII_ISALNUM(*p) || *p == '_')
582 	++p;
583 
584     // Skip over "<type>"; this is permissive about white space.
585     if (*skipwhite(p) == '<')
586     {
587 	p = skipwhite(p);
588 	p = skip_type(skipwhite(p + 1), FALSE);
589 	p = skipwhite(p);
590 	if (*p == '>')
591 	    ++p;
592     }
593     else if ((*p == '(' || (*p == ':' && VIM_ISWHITE(p[1])))
594 					     && STRNCMP("func", start, 4) == 0)
595     {
596 	if (*p == '(')
597 	{
598 	    // handle func(args): type
599 	    ++p;
600 	    while (*p != ')' && *p != NUL)
601 	    {
602 		char_u *sp = p;
603 
604 		if (STRNCMP(p, "...", 3) == 0)
605 		    p += 3;
606 		p = skip_type(p, TRUE);
607 		if (p == sp)
608 		    return p;  // syntax error
609 		if (*p == ',')
610 		    p = skipwhite(p + 1);
611 	    }
612 	    if (*p == ')')
613 	    {
614 		if (p[1] == ':')
615 		    p = skip_type(skipwhite(p + 2), FALSE);
616 		else
617 		    ++p;
618 	    }
619 	}
620 	else
621 	{
622 	    // handle func: return_type
623 	    p = skip_type(skipwhite(p + 1), FALSE);
624 	}
625     }
626 
627     return p;
628 }
629 
630 /*
631  * Parse the member type: "<type>" and return "type" with the member set.
632  * Use "type_gap" if a new type needs to be added.
633  * Returns NULL in case of failure.
634  */
635     static type_T *
636 parse_type_member(
637 	char_u	    **arg,
638 	type_T	    *type,
639 	garray_T    *type_gap,
640 	int	    give_error)
641 {
642     type_T  *member_type;
643     int	    prev_called_emsg = called_emsg;
644 
645     if (**arg != '<')
646     {
647 	if (give_error)
648 	{
649 	    if (*skipwhite(*arg) == '<')
650 		semsg(_(e_no_white_space_allowed_before_str), "<");
651 	    else
652 		emsg(_(e_missing_type));
653 	}
654 	return NULL;
655     }
656     *arg = skipwhite(*arg + 1);
657 
658     member_type = parse_type(arg, type_gap, give_error);
659     if (member_type == NULL)
660 	return NULL;
661 
662     *arg = skipwhite(*arg);
663     if (**arg != '>' && called_emsg == prev_called_emsg)
664     {
665 	if (give_error)
666 	    emsg(_(e_missing_gt_after_type));
667 	return NULL;
668     }
669     ++*arg;
670 
671     if (type->tt_type == VAR_LIST)
672 	return get_list_type(member_type, type_gap);
673     return get_dict_type(member_type, type_gap);
674 }
675 
676 /*
677  * Parse a type at "arg" and advance over it.
678  * When "give_error" is TRUE give error messages, otherwise be quiet.
679  * Return NULL for failure.
680  */
681     type_T *
682 parse_type(char_u **arg, garray_T *type_gap, int give_error)
683 {
684     char_u  *p = *arg;
685     size_t  len;
686 
687     // skip over the first word
688     while (ASCII_ISALNUM(*p) || *p == '_')
689 	++p;
690     len = p - *arg;
691 
692     switch (**arg)
693     {
694 	case 'a':
695 	    if (len == 3 && STRNCMP(*arg, "any", len) == 0)
696 	    {
697 		*arg += len;
698 		return &t_any;
699 	    }
700 	    break;
701 	case 'b':
702 	    if (len == 4 && STRNCMP(*arg, "bool", len) == 0)
703 	    {
704 		*arg += len;
705 		return &t_bool;
706 	    }
707 	    if (len == 4 && STRNCMP(*arg, "blob", len) == 0)
708 	    {
709 		*arg += len;
710 		return &t_blob;
711 	    }
712 	    break;
713 	case 'c':
714 	    if (len == 7 && STRNCMP(*arg, "channel", len) == 0)
715 	    {
716 		*arg += len;
717 		return &t_channel;
718 	    }
719 	    break;
720 	case 'd':
721 	    if (len == 4 && STRNCMP(*arg, "dict", len) == 0)
722 	    {
723 		*arg += len;
724 		return parse_type_member(arg, &t_dict_any,
725 							 type_gap, give_error);
726 	    }
727 	    break;
728 	case 'f':
729 	    if (len == 5 && STRNCMP(*arg, "float", len) == 0)
730 	    {
731 #ifdef FEAT_FLOAT
732 		*arg += len;
733 		return &t_float;
734 #else
735 		if (give_error)
736 		    emsg(_(e_this_vim_is_not_compiled_with_float_support));
737 		return NULL;
738 #endif
739 	    }
740 	    if (len == 4 && STRNCMP(*arg, "func", len) == 0)
741 	    {
742 		type_T  *type;
743 		type_T  *ret_type = &t_unknown;
744 		int	argcount = -1;
745 		int	flags = 0;
746 		int	first_optional = -1;
747 		type_T	*arg_type[MAX_FUNC_ARGS + 1];
748 
749 		// func({type}, ...{type}): {type}
750 		*arg += len;
751 		if (**arg == '(')
752 		{
753 		    // "func" may or may not return a value, "func()" does
754 		    // not return a value.
755 		    ret_type = &t_void;
756 
757 		    p = ++*arg;
758 		    argcount = 0;
759 		    while (*p != NUL && *p != ')')
760 		    {
761 			if (*p == '?')
762 			{
763 			    if (first_optional == -1)
764 				first_optional = argcount;
765 			    ++p;
766 			}
767 			else if (STRNCMP(p, "...", 3) == 0)
768 			{
769 			    flags |= TTFLAG_VARARGS;
770 			    p += 3;
771 			}
772 			else if (first_optional != -1)
773 			{
774 			    if (give_error)
775 				emsg(_(e_mandatory_argument_after_optional_argument));
776 			    return NULL;
777 			}
778 
779 			type = parse_type(&p, type_gap, give_error);
780 			if (type == NULL)
781 			    return NULL;
782 			arg_type[argcount++] = type;
783 
784 			// Nothing comes after "...{type}".
785 			if (flags & TTFLAG_VARARGS)
786 			    break;
787 
788 			if (*p != ',' && *skipwhite(p) == ',')
789 			{
790 			    if (give_error)
791 				semsg(_(e_no_white_space_allowed_before_str), ",");
792 			    return NULL;
793 			}
794 			if (*p == ',')
795 			{
796 			    ++p;
797 			    if (!VIM_ISWHITE(*p))
798 			    {
799 				if (give_error)
800 				    semsg(_(e_white_space_required_after_str), ",");
801 				return NULL;
802 			    }
803 			}
804 			p = skipwhite(p);
805 			if (argcount == MAX_FUNC_ARGS)
806 			{
807 			    if (give_error)
808 				emsg(_(e_too_many_argument_types));
809 			    return NULL;
810 			}
811 		    }
812 
813 		    p = skipwhite(p);
814 		    if (*p != ')')
815 		    {
816 			if (give_error)
817 			    emsg(_(e_missing_close));
818 			return NULL;
819 		    }
820 		    *arg = p + 1;
821 		}
822 		if (**arg == ':')
823 		{
824 		    // parse return type
825 		    ++*arg;
826 		    if (!VIM_ISWHITE(**arg) && give_error)
827 			semsg(_(e_white_space_required_after_str), ":");
828 		    *arg = skipwhite(*arg);
829 		    ret_type = parse_type(arg, type_gap, give_error);
830 		    if (ret_type == NULL)
831 			return NULL;
832 		}
833 		if (flags == 0 && first_optional == -1 && argcount <= 0)
834 		    type = get_func_type(ret_type, argcount, type_gap);
835 		else
836 		{
837 		    type = alloc_func_type(ret_type, argcount, type_gap);
838 		    type->tt_flags = flags;
839 		    if (argcount > 0)
840 		    {
841 			type->tt_argcount = argcount;
842 			type->tt_min_argcount = first_optional == -1
843 						   ? argcount : first_optional;
844 			if (func_type_add_arg_types(type, argcount,
845 							     type_gap) == FAIL)
846 			    return NULL;
847 			mch_memmove(type->tt_args, arg_type,
848 						  sizeof(type_T *) * argcount);
849 		    }
850 		}
851 		return type;
852 	    }
853 	    break;
854 	case 'j':
855 	    if (len == 3 && STRNCMP(*arg, "job", len) == 0)
856 	    {
857 		*arg += len;
858 		return &t_job;
859 	    }
860 	    break;
861 	case 'l':
862 	    if (len == 4 && STRNCMP(*arg, "list", len) == 0)
863 	    {
864 		*arg += len;
865 		return parse_type_member(arg, &t_list_any,
866 							 type_gap, give_error);
867 	    }
868 	    break;
869 	case 'n':
870 	    if (len == 6 && STRNCMP(*arg, "number", len) == 0)
871 	    {
872 		*arg += len;
873 		return &t_number;
874 	    }
875 	    break;
876 	case 's':
877 	    if (len == 6 && STRNCMP(*arg, "string", len) == 0)
878 	    {
879 		*arg += len;
880 		return &t_string;
881 	    }
882 	    break;
883 	case 'v':
884 	    if (len == 4 && STRNCMP(*arg, "void", len) == 0)
885 	    {
886 		*arg += len;
887 		return &t_void;
888 	    }
889 	    break;
890     }
891 
892     if (give_error)
893 	semsg(_(e_type_not_recognized_str), *arg);
894     return NULL;
895 }
896 
897 /*
898  * Check if "type1" and "type2" are exactly the same.
899  */
900     int
901 equal_type(type_T *type1, type_T *type2)
902 {
903     int i;
904 
905     if (type1->tt_type != type2->tt_type)
906 	return FALSE;
907     switch (type1->tt_type)
908     {
909 	case VAR_UNKNOWN:
910 	case VAR_ANY:
911 	case VAR_VOID:
912 	case VAR_SPECIAL:
913 	case VAR_BOOL:
914 	case VAR_NUMBER:
915 	case VAR_FLOAT:
916 	case VAR_STRING:
917 	case VAR_BLOB:
918 	case VAR_JOB:
919 	case VAR_CHANNEL:
920 	    break;  // not composite is always OK
921 	case VAR_LIST:
922 	case VAR_DICT:
923 	    return equal_type(type1->tt_member, type2->tt_member);
924 	case VAR_FUNC:
925 	case VAR_PARTIAL:
926 	    if (!equal_type(type1->tt_member, type2->tt_member)
927 		    || type1->tt_argcount != type2->tt_argcount)
928 		return FALSE;
929 	    if (type1->tt_argcount < 0
930 			   || type1->tt_args == NULL || type2->tt_args == NULL)
931 		return TRUE;
932 	    for (i = 0; i < type1->tt_argcount; ++i)
933 		if (!equal_type(type1->tt_args[i], type2->tt_args[i]))
934 		    return FALSE;
935 	    return TRUE;
936     }
937     return TRUE;
938 }
939 
940 /*
941  * Find the common type of "type1" and "type2" and put it in "dest".
942  * "type2" and "dest" may be the same.
943  */
944     void
945 common_type(type_T *type1, type_T *type2, type_T **dest, garray_T *type_gap)
946 {
947     if (equal_type(type1, type2))
948     {
949 	*dest = type1;
950 	return;
951     }
952 
953     // If either is VAR_UNKNOWN use the other type.  An empty list/dict has no
954     // specific type.
955     if (type1->tt_type == VAR_UNKNOWN)
956     {
957 	*dest = type2;
958 	return;
959     }
960     if (type2->tt_type == VAR_UNKNOWN)
961     {
962 	*dest = type1;
963 	return;
964     }
965 
966     if (type1->tt_type == type2->tt_type)
967     {
968 	if (type1->tt_type == VAR_LIST || type2->tt_type == VAR_DICT)
969 	{
970 	    type_T *common;
971 
972 	    common_type(type1->tt_member, type2->tt_member, &common, type_gap);
973 	    if (type1->tt_type == VAR_LIST)
974 		*dest = get_list_type(common, type_gap);
975 	    else
976 		*dest = get_dict_type(common, type_gap);
977 	    return;
978 	}
979 	if (type1->tt_type == VAR_FUNC)
980 	{
981 	    type_T *common;
982 
983 	    common_type(type1->tt_member, type2->tt_member, &common, type_gap);
984 	    if (type1->tt_argcount == type2->tt_argcount
985 						    && type1->tt_argcount >= 0)
986 	    {
987 		int argcount = type1->tt_argcount;
988 		int i;
989 
990 		*dest = alloc_func_type(common, argcount, type_gap);
991 		if (type1->tt_args != NULL && type2->tt_args != NULL)
992 		{
993 		    if (func_type_add_arg_types(*dest, argcount,
994 							     type_gap) == OK)
995 			for (i = 0; i < argcount; ++i)
996 			    common_type(type1->tt_args[i], type2->tt_args[i],
997 					       &(*dest)->tt_args[i], type_gap);
998 		}
999 	    }
1000 	    else
1001 		*dest = alloc_func_type(common, -1, type_gap);
1002 	    // Use the minimum of min_argcount.
1003 	    (*dest)->tt_min_argcount =
1004 			type1->tt_min_argcount < type2->tt_min_argcount
1005 			     ? type1->tt_min_argcount : type2->tt_min_argcount;
1006 	    return;
1007 	}
1008     }
1009 
1010     *dest = &t_any;
1011 }
1012 
1013 /*
1014  * Get the member type of a dict or list from the items on the stack.
1015  * "stack_top" points just after the last type on the type stack.
1016  * For a list "skip" is 1, for a dict "skip" is 2, keys are skipped.
1017  * Returns &t_void for an empty list or dict.
1018  * Otherwise finds the common type of all items.
1019  */
1020     type_T *
1021 get_member_type_from_stack(
1022 	type_T	    **stack_top,
1023 	int	    count,
1024 	int	    skip,
1025 	garray_T    *type_gap)
1026 {
1027     int	    i;
1028     type_T  *result;
1029     type_T  *type;
1030 
1031     // Use "any" for an empty list or dict.
1032     if (count == 0)
1033 	return &t_unknown;
1034 
1035     // Use the first value type for the list member type, then find the common
1036     // type from following items.
1037     result = *(stack_top -(count * skip) + skip - 1);
1038     for (i = 1; i < count; ++i)
1039     {
1040 	if (result == &t_any)
1041 	    break;  // won't get more common
1042 	type = *(stack_top -((count - i) * skip) + skip - 1);
1043 	common_type(type, result, &result, type_gap);
1044     }
1045 
1046     return result;
1047 }
1048 
1049     char *
1050 vartype_name(vartype_T type)
1051 {
1052     switch (type)
1053     {
1054 	case VAR_UNKNOWN: break;
1055 	case VAR_ANY: return "any";
1056 	case VAR_VOID: return "void";
1057 	case VAR_SPECIAL: return "special";
1058 	case VAR_BOOL: return "bool";
1059 	case VAR_NUMBER: return "number";
1060 	case VAR_FLOAT: return "float";
1061 	case VAR_STRING: return "string";
1062 	case VAR_BLOB: return "blob";
1063 	case VAR_JOB: return "job";
1064 	case VAR_CHANNEL: return "channel";
1065 	case VAR_LIST: return "list";
1066 	case VAR_DICT: return "dict";
1067 
1068 	case VAR_FUNC:
1069 	case VAR_PARTIAL: return "func";
1070     }
1071     return "unknown";
1072 }
1073 
1074 /*
1075  * Return the name of a type.
1076  * The result may be in allocated memory, in which case "tofree" is set.
1077  */
1078     char *
1079 type_name(type_T *type, char **tofree)
1080 {
1081     char *name;
1082 
1083     *tofree = NULL;
1084     if (type == NULL)
1085 	return "[unknown]";
1086     name = vartype_name(type->tt_type);
1087     if (type->tt_type == VAR_LIST || type->tt_type == VAR_DICT)
1088     {
1089 	char *member_free;
1090 	char *member_name = type_name(type->tt_member, &member_free);
1091 	size_t len;
1092 
1093 	len = STRLEN(name) + STRLEN(member_name) + 3;
1094 	*tofree = alloc(len);
1095 	if (*tofree != NULL)
1096 	{
1097 	    vim_snprintf(*tofree, len, "%s<%s>", name, member_name);
1098 	    vim_free(member_free);
1099 	    return *tofree;
1100 	}
1101     }
1102     if (type->tt_type == VAR_FUNC)
1103     {
1104 	garray_T    ga;
1105 	int	    i;
1106 	int	    varargs = (type->tt_flags & TTFLAG_VARARGS) ? 1 : 0;
1107 
1108 	ga_init2(&ga, 1, 100);
1109 	if (ga_grow(&ga, 20) == FAIL)
1110 	    return "[unknown]";
1111 	STRCPY(ga.ga_data, "func(");
1112 	ga.ga_len += 5;
1113 
1114 	for (i = 0; i < type->tt_argcount; ++i)
1115 	{
1116 	    char *arg_free;
1117 	    char *arg_type;
1118 	    int  len;
1119 
1120 	    if (type->tt_args == NULL)
1121 		arg_type = "[unknown]";
1122 	    else
1123 		arg_type = type_name(type->tt_args[i], &arg_free);
1124 	    if (i > 0)
1125 	    {
1126 		STRCPY((char *)ga.ga_data + ga.ga_len, ", ");
1127 		ga.ga_len += 2;
1128 	    }
1129 	    len = (int)STRLEN(arg_type);
1130 	    if (ga_grow(&ga, len + 8) == FAIL)
1131 	    {
1132 		vim_free(arg_free);
1133 		ga_clear(&ga);
1134 		return "[unknown]";
1135 	    }
1136 	    if (varargs && i == type->tt_argcount - 1)
1137 		ga_concat(&ga, (char_u *)"...");
1138 	    else if (i >= type->tt_min_argcount)
1139 		*((char *)ga.ga_data + ga.ga_len++) = '?';
1140 	    ga_concat(&ga, (char_u *)arg_type);
1141 	    vim_free(arg_free);
1142 	}
1143 	if (type->tt_argcount < 0)
1144 	    // any number of arguments
1145 	    ga_concat(&ga, (char_u *)"...");
1146 
1147 	if (type->tt_member == &t_void)
1148 	    STRCPY((char *)ga.ga_data + ga.ga_len, ")");
1149 	else
1150 	{
1151 	    char *ret_free;
1152 	    char *ret_name = type_name(type->tt_member, &ret_free);
1153 	    int  len;
1154 
1155 	    len = (int)STRLEN(ret_name) + 4;
1156 	    if (ga_grow(&ga, len) == FAIL)
1157 	    {
1158 		vim_free(ret_free);
1159 		ga_clear(&ga);
1160 		return "[unknown]";
1161 	    }
1162 	    STRCPY((char *)ga.ga_data + ga.ga_len, "): ");
1163 	    STRCPY((char *)ga.ga_data + ga.ga_len + 3, ret_name);
1164 	    vim_free(ret_free);
1165 	}
1166 	*tofree = ga.ga_data;
1167 	return ga.ga_data;
1168     }
1169 
1170     return name;
1171 }
1172 
1173 #endif // FEAT_EVAL
1174