1 /* Copyright (C) 1996,1997,1998,1999,2000,2001, 2003, 2004, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public License
5 * as published by the Free Software Foundation; either version 3 of
6 * the License, or (at your option) any later version.
8 * This library is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
27 #include "libguile/_scm.h"
28 #include "libguile/async.h"
29 #include "libguile/chars.h"
30 #include "libguile/eval.h"
31 #include "libguile/alist.h"
32 #include "libguile/weaks.h"
33 #include "libguile/hashtab.h"
34 #include "libguile/ports.h"
35 #include "libguile/strings.h"
36 #include "libguile/srfi-13.h"
38 #include "libguile/validate.h"
39 #include "libguile/struct.h"
41 #include "libguile/eq.h"
47 #include "libguile/bdw-gc.h"
51 /* A needlessly obscure test. */
52 #define SCM_LAYOUT_TAILP(X) (((X) & 32) == 0) /* R, W or O */
54 static SCM required_vtable_fields
= SCM_BOOL_F
;
55 static SCM required_applicable_fields
= SCM_BOOL_F
;
56 static SCM required_applicable_with_setter_fields
= SCM_BOOL_F
;
57 SCM scm_struct_table
= SCM_BOOL_F
;
58 SCM scm_applicable_struct_vtable_vtable
;
59 SCM scm_applicable_struct_with_setter_vtable_vtable
;
60 SCM scm_standard_vtable_vtable
;
64 SCM_DEFINE (scm_make_struct_layout
, "make-struct-layout", 1, 0, 0,
66 "Return a new structure layout object.\n\n"
67 "@var{fields} must be a string made up of pairs of characters\n"
68 "strung together. The first character of each pair describes a field\n"
69 "type, the second a field protection. Allowed types are 'p' for\n"
70 "GC-protected Scheme data, 'u' for unprotected binary data, and 's' for\n"
71 "a field that points to the structure itself. Allowed protections\n"
72 "are 'w' for mutable fields, 'h' for hidden fields, 'r' for read-only\n"
73 "fields, and 'o' for opaque fields.\n\n"
74 "Hidden fields are writable, but they will not consume an initializer arg\n"
75 "passed to @code{make-struct}. They are useful to add slots to a struct\n"
76 "in a way that preserves backward-compatibility with existing calls to\n"
77 "@code{make-struct}, especially for derived vtables.\n\n"
78 "The last field protection specification may be capitalized to indicate\n"
79 "that the field is a tail-array.")
80 #define FUNC_NAME s_scm_make_struct_layout
85 SCM_VALIDATE_STRING (1, fields
);
91 len
= scm_i_string_length (fields
);
93 SCM_MISC_ERROR ("odd length field specification: ~S",
96 for (x
= 0; x
< len
; x
+= 2)
98 switch (c
= scm_i_string_ref (fields
, x
))
109 SCM_MISC_ERROR ("unrecognized field type: ~S",
110 scm_list_1 (SCM_MAKE_CHAR (c
)));
113 switch (c
= scm_i_string_ref (fields
, x
+ 1))
117 if (scm_i_string_ref (fields
, x
) == 's')
118 SCM_MISC_ERROR ("self fields not writable", SCM_EOL
);
125 if (scm_i_string_ref (fields
, x
) == 's')
126 SCM_MISC_ERROR ("self fields not allowed in tail array",
129 SCM_MISC_ERROR ("tail array field must be last field in layout",
133 SCM_MISC_ERROR ("unrecognized ref specification: ~S",
134 scm_list_1 (SCM_MAKE_CHAR (c
)));
137 if (scm_i_string_ref (fields
, x
, 'd'))
139 if (!scm_i_string_ref (fields
, x
+2, '-'))
140 SCM_MISC_ERROR ("missing dash field at position ~A",
141 scm_list_1 (scm_from_int (x
/ 2)));
147 new_sym
= scm_string_to_symbol (fields
);
149 scm_remember_upto_here_1 (fields
);
155 /* Check whether VTABLE instances have a simple layout (i.e., either only "pr"
156 or only "pw" fields) and update its flags accordingly. */
158 set_vtable_layout_flags (SCM vtable
)
162 const char *c_layout
;
163 scm_t_bits flags
= SCM_VTABLE_FLAG_SIMPLE
;
165 layout
= SCM_VTABLE_LAYOUT (vtable
);
166 c_layout
= scm_i_symbol_chars (layout
);
167 len
= scm_i_symbol_length (layout
);
169 assert (len
% 2 == 0);
171 /* Update FLAGS according to LAYOUT. */
173 field
< len
&& flags
& SCM_VTABLE_FLAG_SIMPLE
;
176 if (c_layout
[field
] != 'p')
179 switch (c_layout
[field
+ 1])
184 flags
|= SCM_VTABLE_FLAG_SIMPLE_RW
;
189 flags
&= ~SCM_VTABLE_FLAG_SIMPLE_RW
;
197 if (flags
& SCM_VTABLE_FLAG_SIMPLE
)
199 /* VTABLE is simple so update its flags and record the size of its
201 SCM_SET_VTABLE_FLAGS (vtable
, flags
);
202 SCM_STRUCT_DATA_SET (vtable
, scm_vtable_index_size
, len
/ 2);
207 scm_is_valid_vtable_layout (SCM layout
)
210 const char *c_layout
;
212 c_layout
= scm_i_symbol_chars (layout
);
213 len
= scm_i_symbol_length (layout
);
218 for (n
= 0; n
< len
; n
+= 2)
224 switch (c_layout
[n
+1])
246 /* Have OBJ, a newly created vtable, inherit flags from VTABLE. VTABLE is a
247 vtable-vtable and OBJ is an instance of VTABLE. */
249 scm_i_struct_inherit_vtable_magic (SCM vtable
, SCM obj
)
250 #define FUNC_NAME "%inherit-vtable-magic"
252 /* Verily, what is the deal here, you ask? Basically, we need to know a couple
253 of properties of structures at runtime. For example, "is this structure a
254 vtable of vtables (a metaclass)?"; also, "is this structure applicable?".
255 Both of these questions also imply a certain layout of the structure. So
256 instead of checking the layout at runtime, what we do is pre-verify the
257 layout -- so that at runtime we can just check the applicable flag and
258 dispatch directly to the Scheme procedure in slot 0. */
261 /* Verify that OBJ is a valid vtable. */
262 if (! scm_is_valid_vtable_layout (SCM_VTABLE_LAYOUT (obj
)))
263 scm_misc_error (FUNC_NAME
, "invalid layout for new vtable: ~a",
264 scm_list_1 (SCM_VTABLE_LAYOUT (obj
)));
266 set_vtable_layout_flags (obj
);
268 /* If OBJ's vtable is compatible with the required vtable (class) layout, it
270 olayout
= scm_symbol_to_string (SCM_VTABLE_LAYOUT (obj
));
271 if (scm_is_true (scm_leq_p (scm_string_length (required_vtable_fields
),
272 scm_string_length (olayout
)))
273 && scm_is_true (scm_string_eq (olayout
, required_vtable_fields
,
275 scm_string_length (required_vtable_fields
),
277 scm_string_length (required_vtable_fields
))))
278 SCM_SET_VTABLE_FLAGS (obj
, SCM_VTABLE_FLAG_VTABLE
);
280 /* Finally, if OBJ is an applicable class, verify that its vtable is
281 compatible with the required applicable layout. */
282 if (SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_SETTER_VTABLE
))
284 if (scm_is_false (scm_string_eq (olayout
, required_applicable_with_setter_fields
,
288 scm_from_size_t (4))))
289 scm_misc_error (FUNC_NAME
, "invalid applicable-with-setter struct layout",
290 scm_list_1 (olayout
));
291 SCM_SET_VTABLE_FLAGS (obj
, SCM_VTABLE_FLAG_APPLICABLE
| SCM_VTABLE_FLAG_SETTER
);
293 else if (SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_APPLICABLE_VTABLE
))
295 if (scm_is_false (scm_string_eq (olayout
, required_applicable_fields
,
299 scm_from_size_t (2))))
300 scm_misc_error (FUNC_NAME
, "invalid applicable struct layout",
301 scm_list_1 (olayout
));
302 SCM_SET_VTABLE_FLAGS (obj
, SCM_VTABLE_FLAG_APPLICABLE
);
309 scm_struct_init (SCM handle
, SCM layout
, size_t n_tail
,
310 size_t n_inits
, scm_t_bits
*inits
)
315 vtable
= SCM_STRUCT_VTABLE (handle
);
316 mem
= SCM_STRUCT_DATA (handle
);
318 if (SCM_UNPACK (vtable
) != 0
319 && SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_SIMPLE
)
321 && n_inits
== SCM_STRUCT_DATA_REF (vtable
, scm_vtable_index_size
))
322 /* The fast path: HANDLE has N_INITS "p" fields. */
323 memcpy (mem
, inits
, n_inits
* sizeof (SCM
));
326 scm_t_wchar prot
= 0;
327 int n_fields
= scm_i_symbol_length (layout
) / 2;
330 size_t inits_idx
= 0;
338 prot
= scm_i_symbol_ref (layout
, i
+1);
339 if (SCM_LAYOUT_TAILP (prot
))
342 prot
= prot
== 'R' ? 'r' : prot
== 'W' ? 'w' : 'o';
343 *mem
++ = (scm_t_bits
)n_tail
;
344 n_fields
+= n_tail
- 1;
349 switch (scm_i_symbol_ref (layout
, i
))
352 if ((prot
!= 'r' && prot
!= 'w') || inits_idx
== n_inits
)
356 *mem
= scm_to_ulong (SCM_PACK (inits
[inits_idx
]));
362 if ((prot
!= 'r' && prot
!= 'w') || inits_idx
== n_inits
)
363 *mem
= SCM_UNPACK (SCM_BOOL_F
);
366 *mem
= inits
[inits_idx
];
373 *mem
= SCM_UNPACK (handle
);
384 SCM_DEFINE (scm_struct_p
, "struct?", 1, 0, 0,
386 "Return @code{#t} iff @var{x} is a structure object, else\n"
388 #define FUNC_NAME s_scm_struct_p
390 return scm_from_bool(SCM_STRUCTP (x
));
394 SCM_DEFINE (scm_struct_vtable_p
, "struct-vtable?", 1, 0, 0,
396 "Return @code{#t} iff @var{x} is a vtable structure.")
397 #define FUNC_NAME s_scm_struct_vtable_p
401 && SCM_STRUCT_VTABLE_FLAG_IS_SET (x
, SCM_VTABLE_FLAG_VTABLE
));
406 /* Finalization: invoke the finalizer of the struct pointed to by PTR. */
408 struct_finalizer_trampoline (GC_PTR ptr
, GC_PTR unused_data
)
410 SCM obj
= PTR2SCM (ptr
);
411 scm_t_struct_finalize finalize
= SCM_STRUCT_FINALIZER (obj
);
417 /* All struct data must be allocated at an address whose bottom three
418 bits are zero. This is because the tag for a struct lives in the
419 bottom three bits of the struct's car, and the upper bits point to
420 the data of its vtable, which is a struct itself. Thus, if the
421 address of that data doesn't end in three zeros, tagging it will
424 I suppose we should make it clear here that, the data must be 8-byte aligned,
425 *within* the struct, and the struct itself should be 8-byte aligned. In
426 practice we ensure this because the data starts two words into a struct.
428 This function allocates an 8-byte aligned block of memory, whose first word
429 points to the given vtable data, then a data pointer, then n_words of data.
432 scm_i_alloc_struct (scm_t_bits
*vtable_data
, int n_words
)
436 ret
= scm_words ((scm_t_bits
)vtable_data
| scm_tc3_struct
, n_words
+ 2);
437 SCM_SET_CELL_WORD_1 (ret
, (scm_t_bits
)SCM_CELL_OBJECT_LOC (ret
, 2));
439 /* vtable_data can be null when making a vtable vtable */
440 if (vtable_data
&& vtable_data
[scm_vtable_index_instance_finalize
])
442 /* Register a finalizer for the newly created instance. */
443 GC_finalization_proc prev_finalizer
;
444 GC_PTR prev_finalizer_data
;
445 GC_REGISTER_FINALIZER_NO_ORDER (SCM2PTR (ret
),
446 struct_finalizer_trampoline
,
449 &prev_finalizer_data
);
457 scm_c_make_structv (SCM vtable
, size_t n_tail
, size_t n_init
, scm_t_bits
*init
)
458 #define FUNC_NAME "make-struct"
464 SCM_VALIDATE_VTABLE (1, vtable
);
466 layout
= SCM_VTABLE_LAYOUT (vtable
);
467 basic_size
= scm_i_symbol_length (layout
) / 2;
471 SCM layout_str
, last_char
;
476 SCM_MISC_ERROR ("tail array not allowed unless layout ends R, W, or O", SCM_EOL
);
479 layout_str
= scm_symbol_to_string (layout
);
480 last_char
= scm_string_ref (layout_str
,
481 scm_from_size_t (2 * basic_size
- 1));
482 if (! SCM_LAYOUT_TAILP (SCM_CHAR (last_char
)))
486 obj
= scm_i_alloc_struct (SCM_STRUCT_DATA (vtable
), basic_size
+ n_tail
);
488 scm_struct_init (obj
, layout
, n_tail
, n_init
, init
);
490 /* only check things and inherit magic if the layout was passed as an initarg.
491 something of a hack, but it's for back-compatibility. */
492 if (SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_VTABLE
)
493 && scm_is_true (SCM_VTABLE_LAYOUT (obj
)))
494 scm_i_struct_inherit_vtable_magic (vtable
, obj
);
501 scm_c_make_struct (SCM vtable
, size_t n_tail
, size_t n_init
, scm_t_bits init
, ...)
507 v
= alloca (sizeof (scm_t_bits
) * n_init
);
509 va_start (foo
, init
);
510 for (i
= 0; i
< n_init
; i
++)
513 init
= va_arg (foo
, scm_t_bits
);
517 return scm_c_make_structv (vtable
, n_tail
, n_init
, v
);
520 SCM_DEFINE (scm_make_struct
, "make-struct", 2, 0, 1,
521 (SCM vtable
, SCM tail_array_size
, SCM init
),
522 "Create a new structure.\n\n"
523 "@var{type} must be a vtable structure (@pxref{Vtables}).\n\n"
524 "@var{tail-elts} must be a non-negative integer. If the layout\n"
525 "specification indicated by @var{type} includes a tail-array,\n"
526 "this is the number of elements allocated to that array.\n\n"
527 "The @var{init1}, @dots{} are optional arguments describing how\n"
528 "successive fields of the structure should be initialized. Only fields\n"
529 "with protection 'r' or 'w' can be initialized, except for fields of\n"
530 "type 's', which are automatically initialized to point to the new\n"
531 "structure itself. Fields with protection 'o' can not be initialized by\n"
532 "Scheme programs.\n\n"
533 "If fewer optional arguments than initializable fields are supplied,\n"
534 "fields of type 'p' get default value #f while fields of type 'u' are\n"
535 "initialized to 0.\n\n"
536 "For more information, see the documentation for @code{make-vtable-vtable}.")
537 #define FUNC_NAME s_scm_make_struct
543 SCM_VALIDATE_VTABLE (1, vtable
);
544 ilen
= scm_ilength (init
);
546 SCM_MISC_ERROR ("Rest arguments do not form a proper list.", SCM_EOL
);
548 n_init
= (size_t)ilen
;
550 /* best to use alloca, but init could be big, so hack to avoid a possible
553 v
= alloca (n_init
* sizeof(scm_t_bits
));
555 v
= scm_gc_malloc (n_init
* sizeof(scm_t_bits
), "struct");
557 for (i
= 0; i
< n_init
; i
++, init
= SCM_CDR (init
))
558 v
[i
] = SCM_UNPACK (SCM_CAR (init
));
560 return scm_c_make_structv (vtable
, scm_to_size_t (tail_array_size
), n_init
, v
);
566 SCM_DEFINE (scm_make_vtable_vtable
, "make-vtable-vtable", 2, 0, 1,
567 (SCM user_fields
, SCM tail_array_size
, SCM init
),
568 "Return a new, self-describing vtable structure.\n\n"
569 "@var{user-fields} is a string describing user defined fields of the\n"
570 "vtable beginning at index @code{vtable-offset-user}\n"
571 "(see @code{make-struct-layout}).\n\n"
572 "@var{tail-size} specifies the size of the tail-array (if any) of\n"
574 "@var{init1}, @dots{} are the optional initializers for the fields of\n"
576 "Vtables have one initializable system field---the struct printer.\n"
577 "This field comes before the user fields in the initializers passed\n"
578 "to @code{make-vtable-vtable} and @code{make-struct}, and thus works as\n"
579 "a third optional argument to @code{make-vtable-vtable} and a fourth to\n"
580 "@code{make-struct} when creating vtables:\n\n"
581 "If the value is a procedure, it will be called instead of the standard\n"
582 "printer whenever a struct described by this vtable is printed.\n"
583 "The procedure will be called with arguments STRUCT and PORT.\n\n"
584 "The structure of a struct is described by a vtable, so the vtable is\n"
585 "in essence the type of the struct. The vtable is itself a struct with\n"
586 "a vtable. This could go on forever if it weren't for the\n"
587 "vtable-vtables which are self-describing vtables, and thus terminate\n"
589 "There are several potential ways of using structs, but the standard\n"
590 "one is to use three kinds of structs, together building up a type\n"
591 "sub-system: one vtable-vtable working as the root and one or several\n"
592 "\"types\", each with a set of \"instances\". (The vtable-vtable should be\n"
593 "compared to the class <class> which is the class of itself.)\n\n"
595 "(define ball-root (make-vtable-vtable \"pr\" 0))\n\n"
596 "(define (make-ball-type ball-color)\n"
597 " (make-struct ball-root 0\n"
598 " (make-struct-layout \"pw\")\n"
599 " (lambda (ball port)\n"
600 " (format port \"#<a ~A ball owned by ~A>\"\n"
604 "(define (color ball) (struct-ref (struct-vtable ball) vtable-offset-user))\n"
605 "(define (owner ball) (struct-ref ball 0))\n\n"
606 "(define red (make-ball-type 'red))\n"
607 "(define green (make-ball-type 'green))\n\n"
608 "(define (make-ball type owner) (make-struct type 0 owner))\n\n"
609 "(define ball (make-ball green 'Nisse))\n"
610 "ball @result{} #<a green ball owned by Nisse>\n"
612 #define FUNC_NAME s_scm_make_vtable_vtable
614 SCM fields
, layout
, obj
;
615 size_t basic_size
, n_tail
, i
, n_init
;
619 SCM_VALIDATE_STRING (1, user_fields
);
620 ilen
= scm_ilength (init
);
622 SCM_MISC_ERROR ("Rest arguments do not form a proper list.", SCM_EOL
);
624 n_init
= (size_t)ilen
+ 1; /* + 1 for the layout */
626 /* best to use alloca, but init could be big, so hack to avoid a possible
629 v
= alloca (n_init
* sizeof(scm_t_bits
));
631 v
= scm_gc_malloc (n_init
* sizeof(scm_t_bits
), "struct");
633 fields
= scm_string_append (scm_list_2 (required_vtable_fields
,
635 layout
= scm_make_struct_layout (fields
);
636 basic_size
= scm_i_symbol_length (layout
) / 2;
637 n_tail
= scm_to_size_t (tail_array_size
);
640 v
[i
++] = SCM_UNPACK (layout
);
641 for (; i
< n_init
; i
++, init
= SCM_CDR (init
))
642 v
[i
] = SCM_UNPACK (SCM_CAR (init
));
644 SCM_CRITICAL_SECTION_START
;
645 obj
= scm_i_alloc_struct (NULL
, basic_size
+ n_tail
);
646 /* Make it so that the vtable of OBJ is itself. */
647 SCM_SET_CELL_WORD_0 (obj
, (scm_t_bits
) SCM_STRUCT_DATA (obj
) | scm_tc3_struct
);
648 SCM_CRITICAL_SECTION_END
;
650 scm_struct_init (obj
, layout
, n_tail
, n_init
, v
);
651 SCM_SET_VTABLE_FLAGS (obj
, SCM_VTABLE_FLAG_VTABLE
);
658 SCM_DEFINE (scm_make_vtable
, "make-vtable", 1, 1, 0,
659 (SCM fields
, SCM printer
),
660 "Create a vtable, for creating structures with the given\n"
663 "The optional @var{printer} argument is a function to be called\n"
664 "@code{(@var{printer} struct port)} on the structures created.\n"
665 "It should look at @var{struct} and write to @var{port}.")
666 #define FUNC_NAME s_scm_make_vtable
668 if (SCM_UNBNDP (printer
))
669 printer
= SCM_BOOL_F
;
671 return scm_make_struct (scm_standard_vtable_vtable
, SCM_INUM0
,
672 scm_list_2 (scm_make_struct_layout (fields
),
678 /* Return true if S1 and S2 are equal structures, i.e., if their vtable and
679 contents are the same. Field protections are honored. Thus, it is an
680 error to test the equality of structures that contain opaque fields. */
682 scm_i_struct_equalp (SCM s1
, SCM s2
)
683 #define FUNC_NAME "scm_i_struct_equalp"
685 SCM vtable1
, vtable2
, layout
;
686 size_t struct_size
, field_num
;
688 SCM_VALIDATE_STRUCT (1, s1
);
689 SCM_VALIDATE_STRUCT (2, s2
);
691 vtable1
= SCM_STRUCT_VTABLE (s1
);
692 vtable2
= SCM_STRUCT_VTABLE (s2
);
694 if (!scm_is_eq (vtable1
, vtable2
))
697 layout
= SCM_STRUCT_LAYOUT (s1
);
698 struct_size
= scm_i_symbol_length (layout
) / 2;
700 for (field_num
= 0; field_num
< struct_size
; field_num
++)
705 /* We have to use `scm_struct_ref ()' here so that fields are accessed
706 consistently, notably wrt. field types and access rights. */
707 s_field_num
= scm_from_size_t (field_num
);
708 field1
= scm_struct_ref (s1
, s_field_num
);
709 field2
= scm_struct_ref (s2
, s_field_num
);
711 /* Self-referencing fields (type `s') must be skipped to avoid infinite
713 if (!(scm_is_eq (field1
, s1
) && (scm_is_eq (field2
, s2
))))
714 if (scm_is_false (scm_equal_p (field1
, field2
)))
718 /* FIXME: Tail elements should be tested for equality. */
728 SCM_DEFINE (scm_struct_ref
, "struct-ref", 2, 0, 0,
729 (SCM handle
, SCM pos
),
730 "Access the @var{n}th field of @var{struct}.\n\n"
731 "If the field is of type 'p', then it can be set to an arbitrary value.\n\n"
732 "If the field is of type 'u', then it can only be set to a non-negative\n"
733 "integer value small enough to fit in one machine word.")
734 #define FUNC_NAME s_scm_struct_ref
736 SCM vtable
, answer
= SCM_UNDEFINED
;
740 SCM_VALIDATE_STRUCT (1, handle
);
742 vtable
= SCM_STRUCT_VTABLE (handle
);
743 data
= SCM_STRUCT_DATA (handle
);
744 p
= scm_to_size_t (pos
);
746 if (SCM_LIKELY (SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_SIMPLE
)
747 && p
< SCM_STRUCT_DATA_REF (vtable
, scm_vtable_index_size
)))
748 /* The fast path: HANDLE is a struct with only "p" fields. */
749 answer
= SCM_PACK (data
[p
]);
753 size_t layout_len
, n_fields
;
754 scm_t_wchar field_type
= 0;
756 layout
= SCM_STRUCT_LAYOUT (handle
);
757 layout_len
= scm_i_symbol_length (layout
);
758 n_fields
= layout_len
/ 2;
760 if (SCM_LAYOUT_TAILP (scm_i_symbol_ref (layout
, layout_len
- 1)))
761 n_fields
+= data
[n_fields
- 1];
763 SCM_ASSERT_RANGE (1, pos
, p
< n_fields
);
765 if (p
* 2 < layout_len
)
768 field_type
= scm_i_symbol_ref (layout
, p
* 2);
769 ref
= scm_i_symbol_ref (layout
, p
* 2 + 1);
770 if ((ref
!= 'r') && (ref
!= 'w') && (ref
!= 'h'))
772 if ((ref
== 'R') || (ref
== 'W'))
775 SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos
));
778 else if (scm_i_symbol_ref (layout
, layout_len
- 1) != 'O')
779 field_type
= scm_i_symbol_ref(layout
, layout_len
- 2);
781 SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos
));
786 answer
= scm_from_ulong (data
[p
]);
791 answer
= scm_from_long (data
[p
]);
795 answer
= scm_make_real (*((double *)&(data
[p
])));
801 answer
= SCM_PACK (data
[p
]);
806 SCM_MISC_ERROR ("unrecognized field type: ~S",
807 scm_list_1 (SCM_MAKE_CHAR (field_type
)));
816 SCM_DEFINE (scm_struct_set_x
, "struct-set!", 3, 0, 0,
817 (SCM handle
, SCM pos
, SCM val
),
818 "Set the slot of the structure @var{handle} with index @var{pos}\n"
819 "to @var{val}. Signal an error if the slot can not be written\n"
821 #define FUNC_NAME s_scm_struct_set_x
827 SCM_VALIDATE_STRUCT (1, handle
);
829 vtable
= SCM_STRUCT_VTABLE (handle
);
830 data
= SCM_STRUCT_DATA (handle
);
831 p
= scm_to_size_t (pos
);
833 if (SCM_LIKELY (SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_SIMPLE
)
834 && SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_SIMPLE_RW
)
835 && p
< SCM_STRUCT_DATA_REF (vtable
, scm_vtable_index_size
)))
836 /* The fast path: HANDLE is a struct with only "pw" fields. */
837 data
[p
] = SCM_UNPACK (val
);
841 size_t layout_len
, n_fields
;
842 scm_t_wchar field_type
= 0;
844 layout
= SCM_STRUCT_LAYOUT (handle
);
845 layout_len
= scm_i_symbol_length (layout
);
846 n_fields
= layout_len
/ 2;
848 if (SCM_LAYOUT_TAILP (scm_i_symbol_ref (layout
, layout_len
- 1)))
849 n_fields
+= data
[n_fields
- 1];
851 SCM_ASSERT_RANGE (1, pos
, p
< n_fields
);
853 if (p
* 2 < layout_len
)
856 field_type
= scm_i_symbol_ref (layout
, p
* 2);
857 set_x
= scm_i_symbol_ref (layout
, p
* 2 + 1);
858 if (set_x
!= 'w' && set_x
!= 'h')
859 SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos
));
861 else if (scm_i_symbol_ref (layout
, layout_len
- 1) == 'W')
862 field_type
= scm_i_symbol_ref (layout
, layout_len
- 2);
864 SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos
));
869 data
[p
] = SCM_NUM2ULONG (3, val
);
874 data
[p
] = SCM_NUM2LONG (3, val
);
878 *((double *)&(data
[p
])) = scm_num2dbl (val
, (char *)SCM_ARG3
);
883 data
[p
] = SCM_UNPACK (val
);
887 SCM_MISC_ERROR ("self fields immutable", SCM_EOL
);
890 SCM_MISC_ERROR ("unrecognized field type: ~S",
891 scm_list_1 (SCM_MAKE_CHAR (field_type
)));
900 SCM_DEFINE (scm_struct_vtable
, "struct-vtable", 1, 0, 0,
902 "Return the vtable structure that describes the type of @var{struct}.")
903 #define FUNC_NAME s_scm_struct_vtable
905 SCM_VALIDATE_STRUCT (1, handle
);
906 return SCM_STRUCT_VTABLE (handle
);
911 SCM_DEFINE (scm_struct_vtable_tag
, "struct-vtable-tag", 1, 0, 0,
913 "Return the vtable tag of the structure @var{handle}.")
914 #define FUNC_NAME s_scm_struct_vtable_tag
916 SCM_VALIDATE_VTABLE (1, handle
);
917 return scm_from_ulong (((unsigned long)SCM_STRUCT_DATA (handle
)) >> 3);
921 /* {Associating names and classes with vtables}
923 * The name of a vtable should probably be stored as a slot. This is
924 * a backward compatible solution until agreement has been achieved on
925 * how to associate names with vtables.
929 scm_struct_ihashq (SCM obj
, unsigned long n
, void *closure
)
931 /* The length of the hash table should be a relative prime it's not
932 necessary to shift down the address. */
933 return SCM_UNPACK (obj
) % n
;
937 scm_struct_create_handle (SCM obj
)
939 SCM handle
= scm_hash_fn_create_handle_x (scm_struct_table
,
943 (scm_t_assoc_fn
) scm_sloppy_assq
,
945 if (scm_is_false (SCM_CDR (handle
)))
946 SCM_SETCDR (handle
, scm_cons (SCM_BOOL_F
, SCM_BOOL_F
));
950 SCM_DEFINE (scm_struct_vtable_name
, "struct-vtable-name", 1, 0, 0,
952 "Return the name of the vtable @var{vtable}.")
953 #define FUNC_NAME s_scm_struct_vtable_name
955 SCM_VALIDATE_VTABLE (1, vtable
);
956 return SCM_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable
)));
960 SCM_DEFINE (scm_set_struct_vtable_name_x
, "set-struct-vtable-name!", 2, 0, 0,
961 (SCM vtable
, SCM name
),
962 "Set the name of the vtable @var{vtable} to @var{name}.")
963 #define FUNC_NAME s_scm_set_struct_vtable_name_x
965 SCM_VALIDATE_VTABLE (1, vtable
);
966 SCM_VALIDATE_SYMBOL (2, name
);
967 SCM_SET_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable
)),
969 return SCM_UNSPECIFIED
;
977 scm_print_struct (SCM exp
, SCM port
, scm_print_state
*pstate
)
979 if (scm_is_true (scm_procedure_p (SCM_STRUCT_PRINTER (exp
))))
980 scm_printer_apply (SCM_STRUCT_PRINTER (exp
), exp
, port
, pstate
);
983 SCM vtable
= SCM_STRUCT_VTABLE (exp
);
984 SCM name
= scm_struct_vtable_name (vtable
);
985 scm_puts ("#<", port
);
986 if (scm_is_true (name
))
988 scm_display (name
, port
);
989 scm_putc (' ', port
);
993 if (SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_VTABLE
))
994 scm_puts ("vtable:", port
);
996 scm_puts ("struct:", port
);
997 scm_uintprint (SCM_UNPACK (vtable
), 16, port
);
998 scm_putc (' ', port
);
999 scm_write (SCM_VTABLE_LAYOUT (vtable
), port
);
1000 scm_putc (' ', port
);
1002 scm_uintprint (SCM_UNPACK (exp
), 16, port
);
1004 if (SCM_STRUCT_APPLICABLE_P (exp
))
1006 if (scm_is_true (SCM_STRUCT_PROCEDURE (exp
)))
1008 scm_puts (" proc: ", port
);
1009 if (scm_is_true (scm_procedure_p (SCM_STRUCT_PROCEDURE (exp
))))
1010 scm_write (SCM_STRUCT_PROCEDURE (exp
), port
);
1012 scm_puts ("(not a procedure?)", port
);
1014 if (SCM_STRUCT_SETTER_P (exp
))
1016 scm_puts (" setter: ", port
);
1017 scm_write (SCM_STRUCT_SETTER (exp
), port
);
1020 scm_putc ('>', port
);
1027 /* The first word of a struct is equal to `SCM_STRUCT_DATA (vtable) +
1028 scm_tc3_struct', and `SCM_STRUCT_DATA (vtable)' is 2 words after VTABLE by
1030 GC_REGISTER_DISPLACEMENT (2 * sizeof (scm_t_bits
) + scm_tc3_struct
);
1032 /* In the general case, `SCM_STRUCT_DATA (obj)' points 2 words after the
1033 beginning of a GC-allocated region; that region is different from that of
1034 OBJ once OBJ has undergone class redefinition. */
1035 GC_REGISTER_DISPLACEMENT (2 * sizeof (scm_t_bits
));
1037 scm_struct_table
= scm_make_weak_key_hash_table (scm_from_int (31));
1038 required_vtable_fields
= scm_from_locale_string (SCM_VTABLE_BASE_LAYOUT
);
1039 required_applicable_fields
= scm_from_locale_string (SCM_APPLICABLE_BASE_LAYOUT
);
1040 required_applicable_with_setter_fields
= scm_from_locale_string (SCM_APPLICABLE_WITH_SETTER_BASE_LAYOUT
);
1042 scm_standard_vtable_vtable
=
1043 scm_make_vtable_vtable (scm_nullstr
, SCM_INUM0
, SCM_EOL
);
1045 scm_applicable_struct_vtable_vtable
=
1046 scm_make_struct (scm_standard_vtable_vtable
, SCM_INUM0
,
1047 scm_list_1 (scm_make_struct_layout (required_vtable_fields
)));
1048 SCM_SET_VTABLE_FLAGS (scm_applicable_struct_vtable_vtable
,
1049 SCM_VTABLE_FLAG_APPLICABLE_VTABLE
);
1050 scm_c_define ("<applicable-struct-vtable>", scm_applicable_struct_vtable_vtable
);
1052 scm_applicable_struct_with_setter_vtable_vtable
=
1053 scm_make_struct (scm_standard_vtable_vtable
, SCM_INUM0
,
1054 scm_list_1 (scm_make_struct_layout (required_vtable_fields
)));
1055 SCM_SET_VTABLE_FLAGS (scm_applicable_struct_with_setter_vtable_vtable
,
1056 SCM_VTABLE_FLAG_APPLICABLE_VTABLE
| SCM_VTABLE_FLAG_SETTER_VTABLE
);
1057 scm_c_define ("<applicable-struct-with-setter-vtable>", scm_applicable_struct_with_setter_vtable_vtable
);
1059 scm_c_define ("vtable-index-layout", scm_from_int (scm_vtable_index_layout
));
1060 scm_c_define ("vtable-index-printer",
1061 scm_from_int (scm_vtable_index_instance_printer
));
1062 scm_c_define ("vtable-offset-user", scm_from_int (scm_vtable_offset_user
));
1063 #include "libguile/struct.x"