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);
206 /* Have OBJ, a newly created vtable, inherit flags from VTABLE. VTABLE is a
207 vtable-vtable and OBJ is an instance of VTABLE. */
209 scm_i_struct_inherit_vtable_magic (SCM vtable
, SCM obj
)
210 #define FUNC_NAME "%inherit-vtable-magic"
212 /* Verily, what is the deal here, you ask? Basically, we need to know a couple
213 of properties of structures at runtime. For example, "is this structure a
214 vtable of vtables (a metaclass)?"; also, "is this structure applicable?".
215 Both of these questions also imply a certain layout of the structure. So
216 instead of checking the layout at runtime, what we do is pre-verify the
217 layout -- so that at runtime we can just check the applicable flag and
218 dispatch directly to the Scheme procedure in slot 0. */
221 /* Verify that OBJ is a valid vtable. */
222 if (scm_is_false (scm_symbol_p (SCM_VTABLE_LAYOUT (obj
))))
223 scm_misc_error (FUNC_NAME
, "invalid layout for new vtable",
224 scm_list_1 (SCM_VTABLE_LAYOUT (obj
)));
226 set_vtable_layout_flags (obj
);
228 /* If OBJ's vtable is compatible with the required vtable (class) layout, it
230 olayout
= scm_symbol_to_string (SCM_VTABLE_LAYOUT (obj
));
231 if (scm_is_true (scm_leq_p (scm_string_length (required_vtable_fields
),
232 scm_string_length (olayout
)))
233 && scm_is_true (scm_string_eq (olayout
, required_vtable_fields
,
235 scm_string_length (required_vtable_fields
),
237 scm_string_length (required_vtable_fields
))))
238 SCM_SET_VTABLE_FLAGS (obj
, SCM_VTABLE_FLAG_VTABLE
);
240 /* Finally, if OBJ is an applicable class, verify that its vtable is
241 compatible with the required applicable layout. */
242 if (SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_SETTER_VTABLE
))
244 if (scm_is_false (scm_string_eq (olayout
, required_applicable_with_setter_fields
,
248 scm_from_size_t (4))))
249 scm_misc_error (FUNC_NAME
, "invalid applicable-with-setter struct layout",
250 scm_list_1 (olayout
));
251 SCM_SET_VTABLE_FLAGS (obj
, SCM_VTABLE_FLAG_APPLICABLE
| SCM_VTABLE_FLAG_SETTER
);
253 else if (SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_APPLICABLE_VTABLE
))
255 if (scm_is_false (scm_string_eq (olayout
, required_applicable_fields
,
259 scm_from_size_t (2))))
260 scm_misc_error (FUNC_NAME
, "invalid applicable struct layout",
261 scm_list_1 (olayout
));
262 SCM_SET_VTABLE_FLAGS (obj
, SCM_VTABLE_FLAG_APPLICABLE
);
269 scm_struct_init (SCM handle
, SCM layout
, size_t n_tail
,
270 size_t n_inits
, scm_t_bits
*inits
)
275 vtable
= SCM_STRUCT_VTABLE (handle
);
276 mem
= SCM_STRUCT_DATA (handle
);
278 if (SCM_UNPACK (vtable
) != 0
279 && SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_SIMPLE
)
281 && n_inits
== SCM_STRUCT_DATA_REF (vtable
, scm_vtable_index_size
))
282 /* The fast path: HANDLE has N_INITS "p" fields. */
283 memcpy (mem
, inits
, n_inits
* sizeof (SCM
));
286 scm_t_wchar prot
= 0;
287 int n_fields
= scm_i_symbol_length (layout
) / 2;
290 size_t inits_idx
= 0;
298 prot
= scm_i_symbol_ref (layout
, i
+1);
299 if (SCM_LAYOUT_TAILP (prot
))
302 prot
= prot
== 'R' ? 'r' : prot
== 'W' ? 'w' : 'o';
303 *mem
++ = (scm_t_bits
)n_tail
;
304 n_fields
+= n_tail
- 1;
309 switch (scm_i_symbol_ref (layout
, i
))
312 if ((prot
!= 'r' && prot
!= 'w') || inits_idx
== n_inits
)
316 *mem
= scm_to_ulong (SCM_PACK (inits
[inits_idx
]));
322 if ((prot
!= 'r' && prot
!= 'w') || inits_idx
== n_inits
)
323 *mem
= SCM_UNPACK (SCM_BOOL_F
);
326 *mem
= inits
[inits_idx
];
333 *mem
= SCM_UNPACK (handle
);
344 SCM_DEFINE (scm_struct_p
, "struct?", 1, 0, 0,
346 "Return @code{#t} iff @var{x} is a structure object, else\n"
348 #define FUNC_NAME s_scm_struct_p
350 return scm_from_bool(SCM_STRUCTP (x
));
354 SCM_DEFINE (scm_struct_vtable_p
, "struct-vtable?", 1, 0, 0,
356 "Return @code{#t} iff @var{x} is a vtable structure.")
357 #define FUNC_NAME s_scm_struct_vtable_p
361 && SCM_STRUCT_VTABLE_FLAG_IS_SET (x
, SCM_VTABLE_FLAG_VTABLE
));
366 /* Finalization: invoke the finalizer of the struct pointed to by PTR. */
368 struct_finalizer_trampoline (GC_PTR ptr
, GC_PTR unused_data
)
370 SCM obj
= PTR2SCM (ptr
);
371 scm_t_struct_finalize finalize
= SCM_STRUCT_FINALIZER (obj
);
377 /* All struct data must be allocated at an address whose bottom three
378 bits are zero. This is because the tag for a struct lives in the
379 bottom three bits of the struct's car, and the upper bits point to
380 the data of its vtable, which is a struct itself. Thus, if the
381 address of that data doesn't end in three zeros, tagging it will
384 I suppose we should make it clear here that, the data must be 8-byte aligned,
385 *within* the struct, and the struct itself should be 8-byte aligned. In
386 practice we ensure this because the data starts two words into a struct.
388 This function allocates an 8-byte aligned block of memory, whose first word
389 points to the given vtable data, then a data pointer, then n_words of data.
392 scm_i_alloc_struct (scm_t_bits
*vtable_data
, int n_words
)
395 ret
= (scm_t_bits
)scm_gc_malloc (sizeof (scm_t_bits
) * (n_words
+ 2), "struct");
396 SCM_SET_CELL_WORD_0 (SCM_PACK (ret
), (scm_t_bits
)vtable_data
| scm_tc3_struct
);
397 SCM_SET_CELL_WORD_1 (SCM_PACK (ret
),
398 (scm_t_bits
)SCM_CELL_OBJECT_LOC (SCM_PACK (ret
), 2));
400 /* vtable_data can be null when making a vtable vtable */
401 if (vtable_data
&& vtable_data
[scm_vtable_index_instance_finalize
])
403 /* Register a finalizer for the newly created instance. */
404 GC_finalization_proc prev_finalizer
;
405 GC_PTR prev_finalizer_data
;
406 GC_REGISTER_FINALIZER_NO_ORDER ((void*)ret
,
407 struct_finalizer_trampoline
,
410 &prev_finalizer_data
);
413 return SCM_PACK (ret
);
418 scm_c_make_structv (SCM vtable
, size_t n_tail
, size_t n_init
, scm_t_bits
*init
)
419 #define FUNC_NAME "make-struct"
425 SCM_VALIDATE_VTABLE (1, vtable
);
427 layout
= SCM_VTABLE_LAYOUT (vtable
);
428 basic_size
= scm_i_symbol_length (layout
) / 2;
432 SCM layout_str
, last_char
;
437 SCM_MISC_ERROR ("tail array not allowed unless layout ends R, W, or O", SCM_EOL
);
440 layout_str
= scm_symbol_to_string (layout
);
441 last_char
= scm_string_ref (layout_str
,
442 scm_from_size_t (2 * basic_size
- 1));
443 if (! SCM_LAYOUT_TAILP (SCM_CHAR (last_char
)))
447 obj
= scm_i_alloc_struct (SCM_STRUCT_DATA (vtable
), basic_size
+ n_tail
);
449 scm_struct_init (obj
, layout
, n_tail
, n_init
, init
);
451 /* only check things and inherit magic if the layout was passed as an initarg.
452 something of a hack, but it's for back-compatibility. */
453 if (SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_VTABLE
)
454 && scm_is_true (SCM_VTABLE_LAYOUT (obj
)))
455 scm_i_struct_inherit_vtable_magic (vtable
, obj
);
462 scm_c_make_struct (SCM vtable
, size_t n_tail
, size_t n_init
, scm_t_bits init
, ...)
468 v
= alloca (sizeof (scm_t_bits
) * n_init
);
470 va_start (foo
, init
);
471 for (i
= 0; i
< n_init
; i
++)
474 init
= va_arg (foo
, scm_t_bits
);
478 return scm_c_make_structv (vtable
, n_tail
, n_init
, v
);
481 SCM_DEFINE (scm_make_struct
, "make-struct", 2, 0, 1,
482 (SCM vtable
, SCM tail_array_size
, SCM init
),
483 "Create a new structure.\n\n"
484 "@var{type} must be a vtable structure (@pxref{Vtables}).\n\n"
485 "@var{tail-elts} must be a non-negative integer. If the layout\n"
486 "specification indicated by @var{type} includes a tail-array,\n"
487 "this is the number of elements allocated to that array.\n\n"
488 "The @var{init1}, @dots{} are optional arguments describing how\n"
489 "successive fields of the structure should be initialized. Only fields\n"
490 "with protection 'r' or 'w' can be initialized, except for fields of\n"
491 "type 's', which are automatically initialized to point to the new\n"
492 "structure itself. Fields with protection 'o' can not be initialized by\n"
493 "Scheme programs.\n\n"
494 "If fewer optional arguments than initializable fields are supplied,\n"
495 "fields of type 'p' get default value #f while fields of type 'u' are\n"
496 "initialized to 0.\n\n"
497 "For more information, see the documentation for @code{make-vtable-vtable}.")
498 #define FUNC_NAME s_scm_make_struct
504 SCM_VALIDATE_VTABLE (1, vtable
);
505 ilen
= scm_ilength (init
);
507 SCM_MISC_ERROR ("Rest arguments do not form a proper list.", SCM_EOL
);
509 n_init
= (size_t)ilen
;
511 /* best to use alloca, but init could be big, so hack to avoid a possible
514 v
= alloca (n_init
* sizeof(scm_t_bits
));
516 v
= scm_gc_malloc (n_init
* sizeof(scm_t_bits
), "struct");
518 for (i
= 0; i
< n_init
; i
++, init
= SCM_CDR (init
))
519 v
[i
] = SCM_UNPACK (SCM_CAR (init
));
521 return scm_c_make_structv (vtable
, scm_to_size_t (tail_array_size
), n_init
, v
);
527 SCM_DEFINE (scm_make_vtable_vtable
, "make-vtable-vtable", 2, 0, 1,
528 (SCM user_fields
, SCM tail_array_size
, SCM init
),
529 "Return a new, self-describing vtable structure.\n\n"
530 "@var{user-fields} is a string describing user defined fields of the\n"
531 "vtable beginning at index @code{vtable-offset-user}\n"
532 "(see @code{make-struct-layout}).\n\n"
533 "@var{tail-size} specifies the size of the tail-array (if any) of\n"
535 "@var{init1}, @dots{} are the optional initializers for the fields of\n"
537 "Vtables have one initializable system field---the struct printer.\n"
538 "This field comes before the user fields in the initializers passed\n"
539 "to @code{make-vtable-vtable} and @code{make-struct}, and thus works as\n"
540 "a third optional argument to @code{make-vtable-vtable} and a fourth to\n"
541 "@code{make-struct} when creating vtables:\n\n"
542 "If the value is a procedure, it will be called instead of the standard\n"
543 "printer whenever a struct described by this vtable is printed.\n"
544 "The procedure will be called with arguments STRUCT and PORT.\n\n"
545 "The structure of a struct is described by a vtable, so the vtable is\n"
546 "in essence the type of the struct. The vtable is itself a struct with\n"
547 "a vtable. This could go on forever if it weren't for the\n"
548 "vtable-vtables which are self-describing vtables, and thus terminate\n"
550 "There are several potential ways of using structs, but the standard\n"
551 "one is to use three kinds of structs, together building up a type\n"
552 "sub-system: one vtable-vtable working as the root and one or several\n"
553 "\"types\", each with a set of \"instances\". (The vtable-vtable should be\n"
554 "compared to the class <class> which is the class of itself.)\n\n"
556 "(define ball-root (make-vtable-vtable \"pr\" 0))\n\n"
557 "(define (make-ball-type ball-color)\n"
558 " (make-struct ball-root 0\n"
559 " (make-struct-layout \"pw\")\n"
560 " (lambda (ball port)\n"
561 " (format port \"#<a ~A ball owned by ~A>\"\n"
565 "(define (color ball) (struct-ref (struct-vtable ball) vtable-offset-user))\n"
566 "(define (owner ball) (struct-ref ball 0))\n\n"
567 "(define red (make-ball-type 'red))\n"
568 "(define green (make-ball-type 'green))\n\n"
569 "(define (make-ball type owner) (make-struct type 0 owner))\n\n"
570 "(define ball (make-ball green 'Nisse))\n"
571 "ball @result{} #<a green ball owned by Nisse>\n"
573 #define FUNC_NAME s_scm_make_vtable_vtable
575 SCM fields
, layout
, obj
;
576 size_t basic_size
, n_tail
, i
, n_init
;
580 SCM_VALIDATE_STRING (1, user_fields
);
581 ilen
= scm_ilength (init
);
583 SCM_MISC_ERROR ("Rest arguments do not form a proper list.", SCM_EOL
);
585 n_init
= (size_t)ilen
+ 1; /* + 1 for the layout */
587 /* best to use alloca, but init could be big, so hack to avoid a possible
590 v
= alloca (n_init
* sizeof(scm_t_bits
));
592 v
= scm_gc_malloc (n_init
* sizeof(scm_t_bits
), "struct");
594 fields
= scm_string_append (scm_list_2 (required_vtable_fields
,
596 layout
= scm_make_struct_layout (fields
);
597 basic_size
= scm_i_symbol_length (layout
) / 2;
598 n_tail
= scm_to_size_t (tail_array_size
);
601 v
[i
++] = SCM_UNPACK (layout
);
602 for (; i
< n_init
; i
++, init
= SCM_CDR (init
))
603 v
[i
] = SCM_UNPACK (SCM_CAR (init
));
605 SCM_CRITICAL_SECTION_START
;
606 obj
= scm_i_alloc_struct (NULL
, basic_size
+ n_tail
);
607 /* Make it so that the vtable of OBJ is itself. */
608 SCM_SET_CELL_WORD_0 (obj
, (scm_t_bits
) SCM_STRUCT_DATA (obj
) | scm_tc3_struct
);
609 SCM_CRITICAL_SECTION_END
;
611 scm_struct_init (obj
, layout
, n_tail
, n_init
, v
);
612 SCM_SET_VTABLE_FLAGS (obj
, SCM_VTABLE_FLAG_VTABLE
);
619 SCM_DEFINE (scm_make_vtable
, "make-vtable", 1, 1, 0,
620 (SCM fields
, SCM printer
),
621 "Create a vtable, for creating structures with the given\n"
624 "The optional @var{printer} argument is a function to be called\n"
625 "@code{(@var{printer} struct port)} on the structures created.\n"
626 "It should look at @var{struct} and write to @var{port}.")
627 #define FUNC_NAME s_scm_make_vtable
629 if (SCM_UNBNDP (printer
))
630 printer
= SCM_BOOL_F
;
632 return scm_make_struct (scm_standard_vtable_vtable
, SCM_INUM0
,
633 scm_list_2 (scm_make_struct_layout (fields
),
639 /* Return true if S1 and S2 are equal structures, i.e., if their vtable and
640 contents are the same. Field protections are honored. Thus, it is an
641 error to test the equality of structures that contain opaque fields. */
643 scm_i_struct_equalp (SCM s1
, SCM s2
)
644 #define FUNC_NAME "scm_i_struct_equalp"
646 SCM vtable1
, vtable2
, layout
;
647 size_t struct_size
, field_num
;
649 SCM_VALIDATE_STRUCT (1, s1
);
650 SCM_VALIDATE_STRUCT (2, s2
);
652 vtable1
= SCM_STRUCT_VTABLE (s1
);
653 vtable2
= SCM_STRUCT_VTABLE (s2
);
655 if (!scm_is_eq (vtable1
, vtable2
))
658 layout
= SCM_STRUCT_LAYOUT (s1
);
659 struct_size
= scm_i_symbol_length (layout
) / 2;
661 for (field_num
= 0; field_num
< struct_size
; field_num
++)
666 /* We have to use `scm_struct_ref ()' here so that fields are accessed
667 consistently, notably wrt. field types and access rights. */
668 s_field_num
= scm_from_size_t (field_num
);
669 field1
= scm_struct_ref (s1
, s_field_num
);
670 field2
= scm_struct_ref (s2
, s_field_num
);
672 /* Self-referencing fields (type `s') must be skipped to avoid infinite
674 if (!(scm_is_eq (field1
, s1
) && (scm_is_eq (field2
, s2
))))
675 if (scm_is_false (scm_equal_p (field1
, field2
)))
679 /* FIXME: Tail elements should be tested for equality. */
689 SCM_DEFINE (scm_struct_ref
, "struct-ref", 2, 0, 0,
690 (SCM handle
, SCM pos
),
691 "Access the @var{n}th field of @var{struct}.\n\n"
692 "If the field is of type 'p', then it can be set to an arbitrary value.\n\n"
693 "If the field is of type 'u', then it can only be set to a non-negative\n"
694 "integer value small enough to fit in one machine word.")
695 #define FUNC_NAME s_scm_struct_ref
697 SCM vtable
, answer
= SCM_UNDEFINED
;
701 SCM_VALIDATE_STRUCT (1, handle
);
703 vtable
= SCM_STRUCT_VTABLE (handle
);
704 data
= SCM_STRUCT_DATA (handle
);
705 p
= scm_to_size_t (pos
);
707 if (SCM_LIKELY (SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_SIMPLE
)
708 && p
< SCM_STRUCT_DATA_REF (vtable
, scm_vtable_index_size
)))
709 /* The fast path: HANDLE is a struct with only "p" fields. */
710 answer
= SCM_PACK (data
[p
]);
714 size_t layout_len
, n_fields
;
715 scm_t_wchar field_type
= 0;
717 layout
= SCM_STRUCT_LAYOUT (handle
);
718 layout_len
= scm_i_symbol_length (layout
);
719 n_fields
= layout_len
/ 2;
721 if (SCM_LAYOUT_TAILP (scm_i_symbol_ref (layout
, layout_len
- 1)))
722 n_fields
+= data
[n_fields
- 1];
724 SCM_ASSERT_RANGE (1, pos
, p
< n_fields
);
726 if (p
* 2 < layout_len
)
729 field_type
= scm_i_symbol_ref (layout
, p
* 2);
730 ref
= scm_i_symbol_ref (layout
, p
* 2 + 1);
731 if ((ref
!= 'r') && (ref
!= 'w') && (ref
!= 'h'))
733 if ((ref
== 'R') || (ref
== 'W'))
736 SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos
));
739 else if (scm_i_symbol_ref (layout
, layout_len
- 1) != 'O')
740 field_type
= scm_i_symbol_ref(layout
, layout_len
- 2);
742 SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos
));
747 answer
= scm_from_ulong (data
[p
]);
752 answer
= scm_from_long (data
[p
]);
756 answer
= scm_make_real (*((double *)&(data
[p
])));
762 answer
= SCM_PACK (data
[p
]);
767 SCM_MISC_ERROR ("unrecognized field type: ~S",
768 scm_list_1 (SCM_MAKE_CHAR (field_type
)));
777 SCM_DEFINE (scm_struct_set_x
, "struct-set!", 3, 0, 0,
778 (SCM handle
, SCM pos
, SCM val
),
779 "Set the slot of the structure @var{handle} with index @var{pos}\n"
780 "to @var{val}. Signal an error if the slot can not be written\n"
782 #define FUNC_NAME s_scm_struct_set_x
788 SCM_VALIDATE_STRUCT (1, handle
);
790 vtable
= SCM_STRUCT_VTABLE (handle
);
791 data
= SCM_STRUCT_DATA (handle
);
792 p
= scm_to_size_t (pos
);
794 if (SCM_LIKELY (SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_SIMPLE
)
795 && SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_SIMPLE_RW
)
796 && p
< SCM_STRUCT_DATA_REF (vtable
, scm_vtable_index_size
)))
797 /* The fast path: HANDLE is a struct with only "pw" fields. */
798 data
[p
] = SCM_UNPACK (val
);
802 size_t layout_len
, n_fields
;
803 scm_t_wchar field_type
= 0;
805 layout
= SCM_STRUCT_LAYOUT (handle
);
806 layout_len
= scm_i_symbol_length (layout
);
807 n_fields
= layout_len
/ 2;
809 if (SCM_LAYOUT_TAILP (scm_i_symbol_ref (layout
, layout_len
- 1)))
810 n_fields
+= data
[n_fields
- 1];
812 SCM_ASSERT_RANGE (1, pos
, p
< n_fields
);
814 if (p
* 2 < layout_len
)
817 field_type
= scm_i_symbol_ref (layout
, p
* 2);
818 set_x
= scm_i_symbol_ref (layout
, p
* 2 + 1);
819 if (set_x
!= 'w' && set_x
!= 'h')
820 SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos
));
822 else if (scm_i_symbol_ref (layout
, layout_len
- 1) == 'W')
823 field_type
= scm_i_symbol_ref (layout
, layout_len
- 2);
825 SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos
));
830 data
[p
] = SCM_NUM2ULONG (3, val
);
835 data
[p
] = SCM_NUM2LONG (3, val
);
839 *((double *)&(data
[p
])) = scm_num2dbl (val
, (char *)SCM_ARG3
);
844 data
[p
] = SCM_UNPACK (val
);
848 SCM_MISC_ERROR ("self fields immutable", SCM_EOL
);
851 SCM_MISC_ERROR ("unrecognized field type: ~S",
852 scm_list_1 (SCM_MAKE_CHAR (field_type
)));
861 SCM_DEFINE (scm_struct_vtable
, "struct-vtable", 1, 0, 0,
863 "Return the vtable structure that describes the type of @var{struct}.")
864 #define FUNC_NAME s_scm_struct_vtable
866 SCM_VALIDATE_STRUCT (1, handle
);
867 return SCM_STRUCT_VTABLE (handle
);
872 SCM_DEFINE (scm_struct_vtable_tag
, "struct-vtable-tag", 1, 0, 0,
874 "Return the vtable tag of the structure @var{handle}.")
875 #define FUNC_NAME s_scm_struct_vtable_tag
877 SCM_VALIDATE_VTABLE (1, handle
);
878 return scm_from_ulong (((unsigned long)SCM_STRUCT_DATA (handle
)) >> 3);
882 /* {Associating names and classes with vtables}
884 * The name of a vtable should probably be stored as a slot. This is
885 * a backward compatible solution until agreement has been achieved on
886 * how to associate names with vtables.
890 scm_struct_ihashq (SCM obj
, unsigned long n
, void *closure
)
892 /* The length of the hash table should be a relative prime it's not
893 necessary to shift down the address. */
894 return SCM_UNPACK (obj
) % n
;
898 scm_struct_create_handle (SCM obj
)
900 SCM handle
= scm_hash_fn_create_handle_x (scm_struct_table
,
904 (scm_t_assoc_fn
) scm_sloppy_assq
,
906 if (scm_is_false (SCM_CDR (handle
)))
907 SCM_SETCDR (handle
, scm_cons (SCM_BOOL_F
, SCM_BOOL_F
));
911 SCM_DEFINE (scm_struct_vtable_name
, "struct-vtable-name", 1, 0, 0,
913 "Return the name of the vtable @var{vtable}.")
914 #define FUNC_NAME s_scm_struct_vtable_name
916 SCM_VALIDATE_VTABLE (1, vtable
);
917 return SCM_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable
)));
921 SCM_DEFINE (scm_set_struct_vtable_name_x
, "set-struct-vtable-name!", 2, 0, 0,
922 (SCM vtable
, SCM name
),
923 "Set the name of the vtable @var{vtable} to @var{name}.")
924 #define FUNC_NAME s_scm_set_struct_vtable_name_x
926 SCM_VALIDATE_VTABLE (1, vtable
);
927 SCM_VALIDATE_SYMBOL (2, name
);
928 SCM_SET_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable
)),
930 return SCM_UNSPECIFIED
;
938 scm_print_struct (SCM exp
, SCM port
, scm_print_state
*pstate
)
940 if (scm_is_true (scm_procedure_p (SCM_STRUCT_PRINTER (exp
))))
941 scm_printer_apply (SCM_STRUCT_PRINTER (exp
), exp
, port
, pstate
);
944 SCM vtable
= SCM_STRUCT_VTABLE (exp
);
945 SCM name
= scm_struct_vtable_name (vtable
);
946 scm_puts ("#<", port
);
947 if (scm_is_true (name
))
949 scm_display (name
, port
);
950 scm_putc (' ', port
);
954 if (SCM_VTABLE_FLAG_IS_SET (vtable
, SCM_VTABLE_FLAG_VTABLE
))
955 scm_puts ("vtable:", port
);
957 scm_puts ("struct:", port
);
958 scm_uintprint (SCM_UNPACK (vtable
), 16, port
);
959 scm_putc (' ', port
);
960 scm_write (SCM_VTABLE_LAYOUT (vtable
), port
);
961 scm_putc (' ', port
);
963 scm_uintprint (SCM_UNPACK (exp
), 16, port
);
965 if (SCM_STRUCT_APPLICABLE_P (exp
))
967 if (scm_is_true (SCM_STRUCT_PROCEDURE (exp
)))
969 scm_puts (" proc: ", port
);
970 if (scm_is_true (scm_procedure_p (SCM_STRUCT_PROCEDURE (exp
))))
971 scm_write (SCM_STRUCT_PROCEDURE (exp
), port
);
973 scm_puts ("(not a procedure?)", port
);
975 if (SCM_STRUCT_SETTER_P (exp
))
977 scm_puts (" setter: ", port
);
978 scm_write (SCM_STRUCT_SETTER (exp
), port
);
981 scm_putc ('>', port
);
988 /* The first word of a struct is equal to `SCM_STRUCT_DATA (vtable) +
989 scm_tc3_struct', and `SCM_STRUCT_DATA (vtable)' is 2 words after VTABLE by
991 GC_REGISTER_DISPLACEMENT (2 * sizeof (scm_t_bits
) + scm_tc3_struct
);
993 /* In the general case, `SCM_STRUCT_DATA (obj)' points 2 words after the
994 beginning of a GC-allocated region; that region is different from that of
995 OBJ once OBJ has undergone class redefinition. */
996 GC_REGISTER_DISPLACEMENT (2 * sizeof (scm_t_bits
));
998 scm_struct_table
= scm_make_weak_key_hash_table (scm_from_int (31));
999 required_vtable_fields
= scm_from_locale_string (SCM_VTABLE_BASE_LAYOUT
);
1000 required_applicable_fields
= scm_from_locale_string (SCM_APPLICABLE_BASE_LAYOUT
);
1001 required_applicable_with_setter_fields
= scm_from_locale_string (SCM_APPLICABLE_WITH_SETTER_BASE_LAYOUT
);
1003 scm_standard_vtable_vtable
=
1004 scm_make_vtable_vtable (scm_nullstr
, SCM_INUM0
, SCM_EOL
);
1006 scm_applicable_struct_vtable_vtable
=
1007 scm_make_struct (scm_standard_vtable_vtable
, SCM_INUM0
,
1008 scm_list_1 (scm_make_struct_layout (required_vtable_fields
)));
1009 SCM_SET_VTABLE_FLAGS (scm_applicable_struct_vtable_vtable
,
1010 SCM_VTABLE_FLAG_APPLICABLE_VTABLE
);
1011 scm_c_define ("<applicable-struct-vtable>", scm_applicable_struct_vtable_vtable
);
1013 scm_applicable_struct_with_setter_vtable_vtable
=
1014 scm_make_struct (scm_standard_vtable_vtable
, SCM_INUM0
,
1015 scm_list_1 (scm_make_struct_layout (required_vtable_fields
)));
1016 SCM_SET_VTABLE_FLAGS (scm_applicable_struct_with_setter_vtable_vtable
,
1017 SCM_VTABLE_FLAG_APPLICABLE_VTABLE
| SCM_VTABLE_FLAG_SETTER_VTABLE
);
1018 scm_c_define ("<applicable-struct-with-setter-vtable>", scm_applicable_struct_with_setter_vtable_vtable
);
1020 scm_c_define ("vtable-index-layout", scm_from_int (scm_vtable_index_layout
));
1021 scm_c_define ("vtable-index-printer",
1022 scm_from_int (scm_vtable_index_instance_printer
));
1023 scm_c_define ("vtable-offset-user", scm_from_int (scm_vtable_offset_user
));
1024 #include "libguile/struct.x"