-/* Copyright (C) 1996 Free Software Foundation, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this software; see the file COPYING. If not, write to
- * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- * As a special exception, the Free Software Foundation gives permission
- * for additional uses of the text contained in its release of GUILE.
- *
- * The exception is that, if you link the GUILE library with other files
- * to produce an executable, this does not by itself cause the
- * resulting executable to be covered by the GNU General Public License.
- * Your use of that executable is in no way restricted on account of
- * linking the GUILE library code into it.
- *
- * This exception does not however invalidate any other reasons why
- * the executable file might be covered by the GNU General Public License.
- *
- * This exception applies only to the code released by the
- * Free Software Foundation under the name GUILE. If you copy
- * code from other Free Software Foundation releases into a copy of
- * GUILE, as the General Public License permits, the exception does
- * not apply to the code that you add in this way. To avoid misleading
- * anyone as to the status of such modified files, you must delete
- * this exception notice from them.
- *
- * If you write modifications of your own for GUILE, it is your choice
- * whether to permit this exception to apply to your modifications.
- * If you do not wish that, delete this exception notice.
- */
-\f
-
-#include <stdio.h>
-#include "_scm.h"
-
-#ifdef HAVE_STRING_H
-#include <string.h>
-#endif
-
-\f
-
-static SCM required_vtable_fields = SCM_BOOL_F;
-static int struct_num = 0;
-
-\f
-SCM_PROC (s_struct_make_layout, "make-struct-layout", 1, 0, 0, scm_make_struct_layout);
-#ifdef __STDC__
-SCM
-scm_make_struct_layout (SCM fields)
-#else
-SCM
-scm_make_struct_layout (fields)
- SCM fields;
-#endif
-{
- SCM new_sym;
- SCM_ASSERT (SCM_NIMP (fields) && SCM_ROSTRINGP (fields),
- fields, SCM_ARG1, s_struct_make_layout);
-
- {
- char * field_desc;
- int len;
- int x;
-
- len = SCM_ROLENGTH (fields);
- field_desc = SCM_ROCHARS (fields);
- SCM_ASSERT (!(len & 1), fields, "odd length field specification", s_struct_make_layout);
-
- for (x = 0; x < len; x += 2)
- {
- switch (field_desc[x])
- {
- case 'u':
- case 'p':
-#if 0
- case 'i':
- case 'd':
-#endif
- case 's':
- break;
- default:
- SCM_ASSERT (0, SCM_MAKICHR (field_desc[x]) , "unrecognized field type", s_struct_make_layout);
- }
-
- switch (field_desc[x + 1])
- {
- case 'w':
- SCM_ASSERT ((field_desc[x] != 's'), SCM_MAKICHR (field_desc[x + 1]),
- "self fields not writable", s_struct_make_layout);
-
- case 'r':
- case 'o':
- break;
- default:
- SCM_ASSERT (0, SCM_MAKICHR (field_desc[x]) , "unrecognized ref specification", s_struct_make_layout);
- }
-#if 0
- if (field_desc[x] == 'd')
- {
- SCM_ASSERT (field_desc[x + 2] == '-', SCM_MAKINUM (x / 2), "missing dash field", s_struct_make_layout);
- x += 2;
- goto recheck_ref;
- }
-#endif
- }
- new_sym = SCM_CAR (scm_intern_obarray (field_desc, len, SCM_BOOL_F));
- }
- return scm_return_first (new_sym, fields);
-}
-
-\f
-
-
-#ifdef __STDC__
-static void
-init_struct (SCM handle, SCM tail_elts, SCM inits)
-#else
-static void
-init_struct (handle, tail_elts, inits)
- SCM handle;
- SCM tail_elts;
- SCM inits;
-#endif
-{
- SCM layout;
- SCM * data;
- unsigned char * fields_desc;
- int n_fields;
- SCM * mem;
-
- layout = SCM_STRUCT_LAYOUT (handle);
- data = SCM_STRUCT_DATA (handle);
- fields_desc = (unsigned char *)SCM_CHARS (layout);
- n_fields = SCM_LENGTH (layout) / 2;
- mem = SCM_STRUCT_DATA (handle);
- while (n_fields)
- {
- switch (*fields_desc)
- {
-#if 0
- case 'i':
- if ( ((fields_desc[1] != 'r') && (fields_desc[1] != 'w'))
- || ((inits == SCM_EOL) || !SCM_NUMBERP (SCM_CAR (inits))))
- *mem = 0;
- else
- {
- *mem = scm_num2long (SCM_CAR (inits), SCM_ARGn, "init_struct");
- inits = SCM_CDR (inits);
- }
- break;
-#endif
-
- case 'u':
- if ( ((fields_desc[1] != 'r') && (fields_desc[1] != 'w'))
- || ((inits == SCM_EOL) || !SCM_NUMBERP (SCM_CAR (inits))))
- *mem = 0;
- else
- {
- *mem = scm_num2ulong (SCM_CAR (inits), SCM_ARGn, "init_struct");
- inits = SCM_CDR (inits);
- }
- break;
-
- case 'p':
- if ( ((fields_desc[1] != 'r') && (fields_desc[1] != 'w'))
- || (inits == SCM_EOL))
- *mem = SCM_EOL;
- else
- {
- *mem = SCM_CAR (inits);
- inits = SCM_CDR (inits);
- }
-
- break;
-
-#if 0
- case 'd':
- if ( ((fields_desc[1] != 'r') && (fields_desc[1] != 'w'))
- || ((inits == SCM_EOL) || !SCM_NUMBERP (SCM_CAR (inits))))
- *((double *)mem) = 0.0;
- else
- {
- *mem = scm_num2dbl (SCM_CAR (inits), "init_struct");
- inits = SCM_CDR (inits);
- }
- fields_desc += 2;
- break;
-#endif
-
- case 's':
- *mem = handle;
- break;
- }
-
- fields_desc += 2;
- n_fields--;
- mem++;
- }
-}
-
-
-SCM_PROC (s_struct_p, "struct?", 1, 0, 0, scm_struct_p);
-#ifdef __STDC__
-SCM
-scm_struct_p (SCM x)
-#else
-SCM
-scm_struct_p (x)
- SCM x;
-#endif
-{
- return ((SCM_NIMP (x) && SCM_STRUCTP (x))
- ? SCM_BOOL_T
- : SCM_BOOL_F);
-}
-
-SCM_PROC (s_struct_vtable_p, "struct-vtable?", 1, 0, 0, scm_struct_vtable_p);
-#ifdef __STDC__
-SCM
-scm_struct_vtable_p (SCM x)
-#else
-SCM
-scm_struct_vtable_p (x)
- SCM x;
-#endif
-{
- SCM layout;
- SCM * mem;
-
- if (SCM_IMP (x))
- return SCM_BOOL_F;
-
- if (!SCM_STRUCTP (x))
- return SCM_BOOL_F;
-
- layout = SCM_STRUCT_LAYOUT (x);
-
- if (SCM_LENGTH (layout) < SCM_LENGTH (required_vtable_fields))
- return SCM_BOOL_F;
-
- if (strncmp (SCM_CHARS (layout), SCM_CHARS (required_vtable_fields),
- SCM_LENGTH (required_vtable_fields)))
- return SCM_BOOL_F;
-
- mem = SCM_STRUCT_DATA (x);
-
- if (mem[1] != 0)
- return SCM_BOOL_F;
-
- if (SCM_IMP (mem[0]))
- return SCM_BOOL_F;
-
- return (SCM_SYMBOLP (mem[0])
- ? SCM_BOOL_T
- : SCM_BOOL_F);
-}
-
-SCM_PROC (s_make_struct, "make-struct", 2, 0, 1, scm_make_struct);
-#ifdef __STDC__
-SCM
-scm_make_struct (SCM vtable, SCM tail_array_size, SCM init)
-#else
-SCM
-scm_make_struct (vtable, tail_array_size, init)
- SCM vtable;
- SCM tail_array_size;
- SCM init;
-#endif
-{
- SCM layout;
- int basic_size;
- int tail_elts;
- SCM * data;
- SCM handle;
-
- SCM_ASSERT ((SCM_BOOL_F != scm_struct_vtable_p (vtable)),
- vtable, SCM_ARG1, s_make_struct);
- SCM_ASSERT (SCM_INUMP (tail_array_size), tail_array_size, SCM_ARG2, s_make_struct);
-
- layout = SCM_STRUCT_DATA (vtable)[scm_struct_i_layout];
- basic_size = SCM_LENGTH (layout) / 2;
- tail_elts = SCM_INUM (tail_array_size);
- SCM_NEWCELL (handle);
- SCM_DEFER_INTS;
- data = (SCM*)scm_must_malloc (sizeof (SCM) * (2 + basic_size + tail_elts), "structure");
- *data = (SCM)(2 + basic_size + tail_elts);
- data[1] = struct_num++;
- data += 2;
- SCM_SETCDR (handle, data);
- SCM_SETCAR (handle, ((SCM)SCM_STRUCT_DATA (vtable)) + 1);
- init_struct (handle, tail_elts, init);
- SCM_ALLOW_INTS;
- return handle;
-}
-
-
-
-SCM_PROC (s_make_vtable_vtable, "make-vtable-vtable", 2, 0, 1, scm_make_vtable_vtable);
-#ifdef __STDC__
-SCM
-scm_make_vtable_vtable (SCM extra_fields, SCM tail_array_size, SCM init)
-#else
-SCM
-scm_make_vtable_vtable (extra_fields, tail_array_size, init)
- SCM extra_fields;
- SCM tail_array_size;
- SCM init;
-#endif
-{
- SCM fields;
- SCM layout;
- int basic_size;
- int tail_elts;
- SCM * data;
- SCM handle;
-
- SCM_ASSERT (SCM_NIMP (extra_fields) && SCM_ROSTRINGP (extra_fields),
- extra_fields, SCM_ARG1, s_make_vtable_vtable);
- SCM_ASSERT (SCM_INUMP (tail_array_size), tail_array_size, SCM_ARG3, s_make_vtable_vtable);
-
-
- fields = scm_string_append (scm_listify (required_vtable_fields,
- extra_fields,
- SCM_UNDEFINED));
- layout = scm_make_struct_layout (fields);
- basic_size = SCM_LENGTH (layout) / 2;
- tail_elts = SCM_INUM (tail_array_size);
- SCM_NEWCELL (handle);
- SCM_DEFER_INTS;
- data = (SCM*)scm_must_malloc (sizeof (SCM) * (2 + basic_size + tail_elts), "structure");
- *data = (SCM)(2 + basic_size + tail_elts);
- data[1] = struct_num++;
- data += 2;
- SCM_SETCDR (handle, data);
- SCM_SETCAR (handle, ((SCM)data) + 1);
- SCM_STRUCT_LAYOUT (handle) = layout;
- init_struct (handle, tail_elts, scm_cons (layout, init));
- SCM_ALLOW_INTS;
- return handle;
-}
-
-\f
-
-
-SCM_PROC (s_struct_ref, "struct-ref", 2, 0, 0, scm_struct_ref);
-#ifdef __STDC__
-SCM
-scm_struct_ref (SCM handle, SCM pos)
-#else
-SCM
-scm_struct_ref (handle, pos)
- SCM handle;
- SCM pos;
-#endif
-{
- SCM answer;
- SCM * data;
- SCM layout;
- int p;
- int n_fields;
- unsigned char * fields_desc;
- unsigned char field_type;
-
-
- SCM_ASSERT (SCM_NIMP (handle) && SCM_STRUCTP (handle), handle,
- SCM_ARG1, s_struct_ref);
- SCM_ASSERT (SCM_INUMP (pos), pos, SCM_ARG2, s_struct_ref);
-
- layout = SCM_STRUCT_LAYOUT (handle);
- data = SCM_STRUCT_DATA (handle);
- p = SCM_INUM (pos);
-
- fields_desc = (unsigned char *)SCM_CHARS (layout);
- n_fields = SCM_LENGTH (layout) / 2;
-
- SCM_ASSERT (p <= n_fields, pos, SCM_OUTOFRANGE, s_struct_ref);
-
- field_type = fields_desc[p * 2];
- {
- unsigned char ref;
- ref = fields_desc [p * 2 + 1];
- if ((ref != 'r') && (ref != 'w'))
- {
- if ((ref == 'R') || (ref == 'W'))
- field_type = 'u';
- else
- SCM_ASSERT (0, pos, "ref denied", s_struct_ref);
- }
- }
- switch (field_type)
- {
- case 'u':
- answer = scm_ulong2num (data[p]);
- break;
-
-#if 0
- case 'i':
- answer = scm_long2num (data[p]);
- break;
-
- case 'd':
- answer = scm_makdbl (*((double *)&(data[p])), 0.0);
- break;
-#endif
-
- case 's':
- case 'p':
- answer = data[p];
- break;
-
-
- default:
- SCM_ASSERT (0, SCM_MAKICHR (field_type), "unrecognized field type", s_struct_ref);
- break;
- }
-
- return answer;
-}
-
-
-SCM_PROC (s_struct_set_x, "struct-set!", 3, 0, 0, scm_struct_set_x);
-#ifdef __STDC__
-SCM
-scm_struct_set_x (SCM handle, SCM pos, SCM val)
-#else
-SCM
-scm_struct_set_x (handle, pos, val)
- SCM handle;
- SCM pos;
- SCM val;
-#endif
-{
- SCM * data;
- SCM layout;
- int p;
- int n_fields;
- unsigned char * fields_desc;
- unsigned char field_type;
-
-
-
- SCM_ASSERT (SCM_NIMP (handle) && SCM_STRUCTP (handle), handle,
- SCM_ARG1, s_struct_ref);
- SCM_ASSERT (SCM_INUMP (pos), pos, SCM_ARG2, s_struct_ref);
-
- layout = SCM_STRUCT_LAYOUT (handle);
- data = SCM_STRUCT_DATA (handle);
- p = SCM_INUM (pos);
-
- fields_desc = (unsigned char *)SCM_CHARS (layout);
- n_fields = SCM_LENGTH (layout) / 2;
-
- SCM_ASSERT (p <= n_fields, pos, SCM_OUTOFRANGE, s_struct_set_x);
-
- field_type = fields_desc[p * 2];
- {
- unsigned char set_x;
- set_x = fields_desc [p * 2 + 1];
- if (set_x != 'w')
- SCM_ASSERT (0, pos, "set_x denied", s_struct_set_x);
- }
- switch (field_type)
- {
- case 'u':
- data[p] = (SCM)scm_num2ulong (val, (char *)SCM_ARG3, s_struct_set_x);
- break;
-
-#if 0
- case 'i':
- data[p] = scm_num2long (val, (char *)SCM_ARG3, s_struct_set_x);
- break;
-
- case 'd':
- *((double *)&(data[p])) = scm_num2dbl (val, (char *)SCM_ARG3);
- break;
-#endif
-
- case 'p':
- data[p] = val;
- break;
-
- case 's':
- SCM_ASSERT (0, SCM_MAKICHR (field_type), "self fields immutable", s_struct_set_x);
- break;
-
- default:
- SCM_ASSERT (0, SCM_MAKICHR (field_type), "unrecognized field type", s_struct_set_x);
- break;
- }
-
- return val;
-}
-
-
-SCM_PROC (s_struct_vtable, "struct-vtable", 1, 0, 0, scm_struct_vtable);
-#ifdef __STDC__
-SCM
-scm_struct_vtable (SCM handle)
-#else
-SCM
-scm_struct_vtable (handle)
- SCM handle;
-#endif
-{
- SCM_ASSERT (SCM_NIMP (handle) && SCM_STRUCTP (handle), handle,
- SCM_ARG1, s_struct_vtable);
- return SCM_STRUCT_VTABLE (handle);
-}
-
-
-SCM_PROC (s_struct_vtable_tag, "struct-vtable-tag", 1, 0, 0, scm_struct_vtable_tag);
-#ifdef __STDC__
-SCM
-scm_struct_vtable_tag (SCM handle)
-#else
-SCM
-scm_struct_vtable_tag (handle)
- SCM handle;
-#endif
-{
- SCM_ASSERT (SCM_NIMP (handle) && (SCM_BOOL_F != scm_struct_vtable_p (handle)),
- handle, SCM_ARG1, s_struct_vtable_tag);
- return scm_long2num (SCM_STRUCT_DATA (handle)[-1]);
-}
-
-
-\f
-
-#ifdef __STDC__
-void
-scm_init_struct (void)
-#else
-void
-scm_init_struct ()
-#endif
-{
- required_vtable_fields = SCM_CAR (scm_intern_obarray ("pruosr", sizeof ("pruosr") - 1, SCM_BOOL_F));
- scm_permanent_object (required_vtable_fields);
- scm_sysintern ("struct-vtable-offset", SCM_MAKINUM (scm_struct_i_vtable_offset));
-#include "struct.x"
-}
-
+/* Copyright (C) 1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this software; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307 USA
+ *
+ * As a special exception, the Free Software Foundation gives permission
+ * for additional uses of the text contained in its release of GUILE.
+ *
+ * The exception is that, if you link the GUILE library with other files
+ * to produce an executable, this does not by itself cause the
+ * resulting executable to be covered by the GNU General Public License.
+ * Your use of that executable is in no way restricted on account of
+ * linking the GUILE library code into it.
+ *
+ * This exception does not however invalidate any other reasons why
+ * the executable file might be covered by the GNU General Public License.
+ *
+ * This exception applies only to the code released by the
+ * Free Software Foundation under the name GUILE. If you copy
+ * code from other Free Software Foundation releases into a copy of
+ * GUILE, as the General Public License permits, the exception does
+ * not apply to the code that you add in this way. To avoid misleading
+ * anyone as to the status of such modified files, you must delete
+ * this exception notice from them.
+ *
+ * If you write modifications of your own for GUILE, it is your choice
+ * whether to permit this exception to apply to your modifications.
+ * If you do not wish that, delete this exception notice. */
+
+
+\f
+
+#include "libguile/_scm.h"
+#include "libguile/chars.h"
+#include "libguile/eval.h"
+#include "libguile/alist.h"
+#include "libguile/weaks.h"
+#include "libguile/hashtab.h"
+#include "libguile/ports.h"
+#include "libguile/strings.h"
+
+#include "libguile/validate.h"
+#include "libguile/struct.h"
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+
+\f
+
+static SCM required_vtable_fields = SCM_BOOL_F;
+SCM scm_struct_table;
+
+\f
+SCM_DEFINE (scm_make_struct_layout, "make-struct-layout", 1, 0, 0,
+ (SCM fields),
+ "Return a new structure layout object.\n\n"
+ "@var{fields} must be a string made up of pairs of characters\n"
+ "strung together. The first character of each pair describes a field\n"
+ "type, the second a field protection. Allowed types are 'p' for\n"
+ "GC-protected Scheme data, 'u' for unprotected binary data, and 's' for\n"
+ "a field that points to the structure itself. Allowed protections\n"
+ "are 'w' for mutable fields, 'r' for read-only fields, and 'o' for opaque\n"
+ "fields. The last field protection specification may be capitalized to\n"
+ "indicate that the field is a tail-array.")
+#define FUNC_NAME s_scm_make_struct_layout
+{
+ SCM new_sym;
+ SCM_VALIDATE_STRING (1, fields);
+
+ { /* scope */
+ char * field_desc;
+ size_t len;
+ int x;
+
+ len = SCM_STRING_LENGTH (fields);
+ if (len % 2 == 1)
+ SCM_MISC_ERROR ("odd length field specification: ~S",
+ scm_list_1 (fields));
+
+ field_desc = SCM_STRING_CHARS (fields);
+
+ for (x = 0; x < len; x += 2)
+ {
+ switch (field_desc[x])
+ {
+ case 'u':
+ case 'p':
+#if 0
+ case 'i':
+ case 'd':
+#endif
+ case 's':
+ break;
+ default:
+ SCM_MISC_ERROR ("unrecognized field type: ~S",
+ scm_list_1 (SCM_MAKE_CHAR (field_desc[x])));
+ }
+
+ switch (field_desc[x + 1])
+ {
+ case 'w':
+ if (field_desc[x] == 's')
+ SCM_MISC_ERROR ("self fields not writable", SCM_EOL);
+ case 'r':
+ case 'o':
+ break;
+ case 'R':
+ case 'W':
+ case 'O':
+ if (field_desc[x] == 's')
+ SCM_MISC_ERROR ("self fields not allowed in tail array",
+ SCM_EOL);
+ if (x != len - 2)
+ SCM_MISC_ERROR ("tail array field must be last field in layout",
+ SCM_EOL);
+ break;
+ default:
+ SCM_MISC_ERROR ("unrecognized ref specification: ~S",
+ scm_list_1 (SCM_MAKE_CHAR (field_desc[x + 1])));
+ }
+#if 0
+ if (field_desc[x] == 'd')
+ {
+ if (field_desc[x + 2] != '-')
+ SCM_MISC_ERROR ("missing dash field at position ~A",
+ scm_list_1 (SCM_MAKINUM (x / 2)));
+ x += 2;
+ goto recheck_ref;
+ }
+#endif
+ }
+ new_sym = scm_mem2symbol (field_desc, len);
+ }
+ return scm_return_first (new_sym, fields);
+}
+#undef FUNC_NAME
+
+\f
+
+
+
+static void
+scm_struct_init (SCM handle, SCM layout, scm_t_bits * mem, int tail_elts, SCM inits)
+{
+ unsigned char * fields_desc = (unsigned char *) SCM_SYMBOL_CHARS (layout) - 2;
+ unsigned char prot = 0;
+ int n_fields = SCM_SYMBOL_LENGTH (layout) / 2;
+ int tailp = 0;
+
+ while (n_fields)
+ {
+ if (!tailp)
+ {
+ fields_desc += 2;
+ prot = fields_desc[1];
+ if (SCM_LAYOUT_TAILP (prot))
+ {
+ tailp = 1;
+ prot = prot == 'R' ? 'r' : prot == 'W' ? 'w' : 'o';
+ *mem++ = tail_elts;
+ n_fields += tail_elts - 1;
+ if (n_fields == 0)
+ break;
+ }
+ }
+
+ switch (*fields_desc)
+ {
+#if 0
+ case 'i':
+ if ((prot != 'r' && prot != 'w') || inits == SCM_EOL)
+ *mem = 0;
+ else
+ {
+ *mem = scm_num2long (SCM_CAR (inits), SCM_ARGn, "scm_struct_init");
+ inits = SCM_CDR (inits);
+ }
+ break;
+#endif
+
+ case 'u':
+ if ((prot != 'r' && prot != 'w') || SCM_NULLP (inits))
+ *mem = 0;
+ else
+ {
+ *mem = scm_num2ulong (SCM_CAR (inits),
+ SCM_ARGn,
+ "scm_struct_init");
+ inits = SCM_CDR (inits);
+ }
+ break;
+
+ case 'p':
+ if ((prot != 'r' && prot != 'w') || SCM_NULLP (inits))
+ *mem = SCM_UNPACK (SCM_BOOL_F);
+ else
+ {
+ *mem = SCM_UNPACK (SCM_CAR (inits));
+ inits = SCM_CDR (inits);
+ }
+
+ break;
+
+#if 0
+ case 'd':
+ if ((prot != 'r' && prot != 'w') || inits == SCM_EOL)
+ *((double *)mem) = 0.0;
+ else
+ {
+ *mem = scm_num2dbl (SCM_CAR (inits), "scm_struct_init");
+ inits = SCM_CDR (inits);
+ }
+ fields_desc += 2;
+ break;
+#endif
+
+ case 's':
+ *mem = SCM_UNPACK (handle);
+ break;
+ }
+
+ n_fields--;
+ mem++;
+ }
+}
+
+
+SCM_DEFINE (scm_struct_p, "struct?", 1, 0, 0,
+ (SCM x),
+ "Return @code{#t} iff @var{x} is a structure object, else\n"
+ "@code{#f}.")
+#define FUNC_NAME s_scm_struct_p
+{
+ return SCM_BOOL(SCM_STRUCTP (x));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_struct_vtable_p, "struct-vtable?", 1, 0, 0,
+ (SCM x),
+ "Return @code{#t} iff @var{x} is a vtable structure.")
+#define FUNC_NAME s_scm_struct_vtable_p
+{
+ SCM layout;
+ scm_t_bits * mem;
+
+ if (!SCM_STRUCTP (x))
+ return SCM_BOOL_F;
+
+ layout = SCM_STRUCT_LAYOUT (x);
+
+ if (SCM_SYMBOL_LENGTH (layout) < SCM_STRING_LENGTH (required_vtable_fields))
+ return SCM_BOOL_F;
+
+ if (strncmp (SCM_SYMBOL_CHARS (layout), SCM_STRING_CHARS (required_vtable_fields),
+ SCM_STRING_LENGTH (required_vtable_fields)))
+ return SCM_BOOL_F;
+
+ mem = SCM_STRUCT_DATA (x);
+
+ return SCM_BOOL (SCM_SYMBOLP (SCM_PACK (mem[scm_vtable_index_layout])));
+}
+#undef FUNC_NAME
+
+
+/* All struct data must be allocated at an address whose bottom three
+ bits are zero. This is because the tag for a struct lives in the
+ bottom three bits of the struct's car, and the upper bits point to
+ the data of its vtable, which is a struct itself. Thus, if the
+ address of that data doesn't end in three zeros, tagging it will
+ destroy the pointer.
+
+ This function allocates a block of memory, and returns a pointer at
+ least scm_struct_n_extra_words words into the block. Furthermore,
+ it guarantees that that pointer's least three significant bits are
+ all zero.
+
+ The argument n_words should be the number of words that should
+ appear after the returned address. (That is, it shouldn't include
+ scm_struct_n_extra_words.)
+
+ This function initializes the following fields of the struct:
+
+ scm_struct_i_ptr --- the actual start of the block of memory; the
+ address you should pass to 'free' to dispose of the block.
+ This field allows us to both guarantee that the returned
+ address is divisible by eight, and allow the GC to free the
+ block.
+
+ scm_struct_i_n_words --- the number of words allocated to the
+ block, including the extra fields. This is used by the GC.
+
+ Ugh. */
+
+
+scm_t_bits *
+scm_alloc_struct (int n_words, int n_extra, const char *what)
+{
+ int size = sizeof (scm_t_bits) * (n_words + n_extra) + 7;
+ void * block = scm_gc_malloc (size, what);
+
+ /* Adjust the pointer to hide the extra words. */
+ scm_t_bits * p = (scm_t_bits *) block + n_extra;
+
+ /* Adjust it even further so it's aligned on an eight-byte boundary. */
+ p = (scm_t_bits *) (((scm_t_bits) p + 7) & ~7);
+
+ /* Initialize a few fields as described above. */
+ p[scm_struct_i_free] = (scm_t_bits) scm_struct_free_standard;
+ p[scm_struct_i_ptr] = (scm_t_bits) block;
+ p[scm_struct_i_n_words] = n_words;
+ p[scm_struct_i_flags] = 0;
+
+ return p;
+}
+
+void
+scm_struct_free_0 (scm_t_bits * vtable SCM_UNUSED,
+ scm_t_bits * data SCM_UNUSED)
+{
+}
+
+void
+scm_struct_free_light (scm_t_bits * vtable, scm_t_bits * data)
+{
+ size_t n = vtable [scm_struct_i_size] & ~SCM_STRUCTF_MASK;
+ scm_gc_free (data, n, "struct");
+}
+
+void
+scm_struct_free_standard (scm_t_bits * vtable SCM_UNUSED, scm_t_bits * data)
+{
+ size_t n = (data[scm_struct_i_n_words] + scm_struct_n_extra_words)
+ * sizeof (scm_t_bits) + 7;
+ scm_gc_free ((void *) data[scm_struct_i_ptr], n, "heavy struct");
+}
+
+void
+scm_struct_free_entity (scm_t_bits * vtable SCM_UNUSED, scm_t_bits * data)
+{
+ size_t n = (data[scm_struct_i_n_words] + scm_struct_entity_n_extra_words)
+ * sizeof (scm_t_bits) + 7;
+ scm_gc_free ((void *) data[scm_struct_i_ptr], n, "entity struct");
+}
+
+static void *
+scm_struct_gc_init (void *dummy1 SCM_UNUSED,
+ void *dummy2 SCM_UNUSED,
+ void *dummy3 SCM_UNUSED)
+{
+ scm_structs_to_free = SCM_EOL;
+ return 0;
+}
+
+static void *
+scm_free_structs (void *dummy1 SCM_UNUSED,
+ void *dummy2 SCM_UNUSED,
+ void *dummy3 SCM_UNUSED)
+{
+ SCM newchain = scm_structs_to_free;
+ do
+ {
+ /* Mark vtables in GC chain. GC mark set means delay freeing. */
+ SCM chain = newchain;
+ while (!SCM_NULLP (chain))
+ {
+ SCM vtable = SCM_STRUCT_VTABLE (chain);
+ if (SCM_STRUCT_GC_CHAIN (vtable) != 0 && vtable != chain)
+ SCM_SETGCMARK (vtable);
+ chain = SCM_STRUCT_GC_CHAIN (chain);
+ }
+ /* Free unmarked structs. */
+ chain = newchain;
+ newchain = SCM_EOL;
+ while (!SCM_NULLP (chain))
+ {
+ SCM obj = chain;
+ chain = SCM_STRUCT_GC_CHAIN (chain);
+ if (SCM_GCMARKP (obj))
+ {
+ SCM_CLRGCMARK (obj);
+ SCM_SET_STRUCT_GC_CHAIN (obj, newchain);
+ newchain = obj;
+ }
+ else
+ {
+ /* XXX - use less explicit code. */
+ scm_t_bits word0 = SCM_CELL_WORD_0 (obj) - scm_tc3_struct;
+ scm_t_bits * vtable_data = (scm_t_bits *) word0;
+ scm_t_bits * data = SCM_STRUCT_DATA (obj);
+ scm_t_struct_free free_struct_data
+ = ((scm_t_struct_free) vtable_data[scm_struct_i_free]);
+ SCM_SET_CELL_TYPE (obj, scm_tc_free_cell);
+ free_struct_data (vtable_data, data);
+ }
+ }
+ }
+ while (!SCM_NULLP (newchain));
+ return 0;
+}
+
+SCM_DEFINE (scm_make_struct, "make-struct", 2, 0, 1,
+ (SCM vtable, SCM tail_array_size, SCM init),
+ "Create a new structure.\n\n"
+ "@var{type} must be a vtable structure (@pxref{Vtables}).\n\n"
+ "@var{tail-elts} must be a non-negative integer. If the layout\n"
+ "specification indicated by @var{type} includes a tail-array,\n"
+ "this is the number of elements allocated to that array.\n\n"
+ "The @var{init1}, @dots{} are optional arguments describing how\n"
+ "successive fields of the structure should be initialized. Only fields\n"
+ "with protection 'r' or 'w' can be initialized, except for fields of\n"
+ "type 's', which are automatically initialized to point to the new\n"
+ "structure itself; fields with protection 'o' can not be initialized by\n"
+ "Scheme programs.\n\n"
+ "If fewer optional arguments than initializable fields are supplied,\n"
+ "fields of type 'p' get default value #f while fields of type 'u' are\n"
+ "initialized to 0.\n\n"
+ "Structs are currently the basic representation for record-like data\n"
+ "structures in Guile. The plan is to eventually replace them with a\n"
+ "new representation which will at the same time be easier to use and\n"
+ "more powerful.\n\n"
+ "For more information, see the documentation for @code{make-vtable-vtable}.")
+#define FUNC_NAME s_scm_make_struct
+{
+ SCM layout;
+ int basic_size;
+ int tail_elts;
+ scm_t_bits * data;
+ SCM handle;
+
+ SCM_VALIDATE_VTABLE (1, vtable);
+ SCM_VALIDATE_INUM (2, tail_array_size);
+ SCM_VALIDATE_REST_ARGUMENT (init);
+
+ layout = SCM_PACK (SCM_STRUCT_DATA (vtable) [scm_vtable_index_layout]);
+ basic_size = SCM_SYMBOL_LENGTH (layout) / 2;
+ tail_elts = SCM_INUM (tail_array_size);
+ SCM_DEFER_INTS;
+ if (SCM_STRUCT_DATA (vtable)[scm_struct_i_flags] & SCM_STRUCTF_ENTITY)
+ {
+ data = scm_alloc_struct (basic_size + tail_elts,
+ scm_struct_entity_n_extra_words,
+ "entity struct");
+ data[scm_struct_i_procedure] = SCM_UNPACK (SCM_BOOL_F);
+ data[scm_struct_i_setter] = SCM_UNPACK (SCM_BOOL_F);
+ }
+ else
+ data = scm_alloc_struct (basic_size + tail_elts,
+ scm_struct_n_extra_words,
+ "struct");
+ handle = scm_double_cell ((((scm_t_bits) SCM_STRUCT_DATA (vtable))
+ + scm_tc3_struct),
+ (scm_t_bits) data, 0, 0);
+ scm_struct_init (handle, layout, data, tail_elts, init);
+ SCM_ALLOW_INTS;
+ return handle;
+}
+#undef FUNC_NAME
+
+
+
+SCM_DEFINE (scm_make_vtable_vtable, "make-vtable-vtable", 2, 0, 1,
+ (SCM user_fields, SCM tail_array_size, SCM init),
+ "Return a new, self-describing vtable structure.\n\n"
+ "@var{user-fields} is a string describing user defined fields of the\n"
+ "vtable beginning at index @code{vtable-offset-user}\n"
+ "(see @code{make-struct-layout}).\n\n"
+ "@var{tail-size} specifies the size of the tail-array (if any) of\n"
+ "this vtable.\n\n"
+ "@var{init1}, @dots{} are the optional initializers for the fields of\n"
+ "the vtable.\n\n"
+ "Vtables have one initializable system field---the struct printer.\n"
+ "This field comes before the user fields in the initializers passed\n"
+ "to @code{make-vtable-vtable} and @code{make-struct}, and thus works as\n"
+ "a third optional argument to @code{make-vtable-vtable} and a fourth to\n"
+ "@code{make-struct} when creating vtables:\n\n"
+ "If the value is a procedure, it will be called instead of the standard\n"
+ "printer whenever a struct described by this vtable is printed.\n"
+ "The procedure will be called with arguments STRUCT and PORT.\n\n"
+ "The structure of a struct is described by a vtable, so the vtable is\n"
+ "in essence the type of the struct. The vtable is itself a struct with\n"
+ "a vtable. This could go on forever if it weren't for the\n"
+ "vtable-vtables which are self-describing vtables, and thus terminate\n"
+ "the chain.\n\n"
+ "There are several potential ways of using structs, but the standard\n"
+ "one is to use three kinds of structs, together building up a type\n"
+ "sub-system: one vtable-vtable working as the root and one or several\n"
+ "\"types\", each with a set of \"instances\". (The vtable-vtable should be\n"
+ "compared to the class <class> which is the class of itself.)\n\n"
+ "@lisp\n"
+ "(define ball-root (make-vtable-vtable \"pr\" 0))\n\n"
+ "(define (make-ball-type ball-color)\n"
+ " (make-struct ball-root 0\n"
+ " (make-struct-layout \"pw\")\n"
+ " (lambda (ball port)\n"
+ " (format port \"#<a ~A ball owned by ~A>\"\n"
+ " (color ball)\n"
+ " (owner ball)))\n"
+ " ball-color))\n"
+ "(define (color ball) (struct-ref (struct-vtable ball) vtable-offset-user))\n"
+ "(define (owner ball) (struct-ref ball 0))\n\n"
+ "(define red (make-ball-type 'red))\n"
+ "(define green (make-ball-type 'green))\n\n"
+ "(define (make-ball type owner) (make-struct type 0 owner))\n\n"
+ "(define ball (make-ball green 'Nisse))\n"
+ "ball @result{} #<a green ball owned by Nisse>\n"
+ "@end lisp")
+#define FUNC_NAME s_scm_make_vtable_vtable
+{
+ SCM fields;
+ SCM layout;
+ int basic_size;
+ int tail_elts;
+ scm_t_bits * data;
+ SCM handle;
+
+ SCM_VALIDATE_STRING (1, user_fields);
+ SCM_VALIDATE_INUM (2, tail_array_size);
+ SCM_VALIDATE_REST_ARGUMENT (init);
+
+ fields = scm_string_append (scm_list_2 (required_vtable_fields,
+ user_fields));
+ layout = scm_make_struct_layout (fields);
+ basic_size = SCM_SYMBOL_LENGTH (layout) / 2;
+ tail_elts = SCM_INUM (tail_array_size);
+ SCM_DEFER_INTS;
+ data = scm_alloc_struct (basic_size + tail_elts,
+ scm_struct_n_extra_words,
+ "struct");
+ handle = scm_double_cell ((scm_t_bits) data + scm_tc3_struct,
+ (scm_t_bits) data, 0, 0);
+ data [scm_vtable_index_layout] = SCM_UNPACK (layout);
+ scm_struct_init (handle, layout, data, tail_elts, scm_cons (layout, init));
+ SCM_ALLOW_INTS;
+ return handle;
+}
+#undef FUNC_NAME
+
+\f
+
+
+SCM_DEFINE (scm_struct_ref, "struct-ref", 2, 0, 0,
+ (SCM handle, SCM pos),
+ "@deffnx {Scheme Procedure} struct-set! struct n value\n"
+ "Access (or modify) the @var{n}th field of @var{struct}.\n\n"
+ "If the field is of type 'p', then it can be set to an arbitrary value.\n\n"
+ "If the field is of type 'u', then it can only be set to a non-negative\n"
+ "integer value small enough to fit in one machine word.")
+#define FUNC_NAME s_scm_struct_ref
+{
+ SCM answer = SCM_UNDEFINED;
+ scm_t_bits * data;
+ SCM layout;
+ int p;
+ scm_t_bits n_fields;
+ char * fields_desc;
+ char field_type = 0;
+
+
+ SCM_VALIDATE_STRUCT (1, handle);
+ SCM_VALIDATE_INUM (2, pos);
+
+ layout = SCM_STRUCT_LAYOUT (handle);
+ data = SCM_STRUCT_DATA (handle);
+ p = SCM_INUM (pos);
+
+ fields_desc = SCM_SYMBOL_CHARS (layout);
+ n_fields = data[scm_struct_i_n_words];
+
+ SCM_ASSERT_RANGE(1, pos, p < n_fields);
+
+ if (p * 2 < SCM_SYMBOL_LENGTH (layout))
+ {
+ char ref;
+ field_type = fields_desc[p * 2];
+ ref = fields_desc[p * 2 + 1];
+ if ((ref != 'r') && (ref != 'w'))
+ {
+ if ((ref == 'R') || (ref == 'W'))
+ field_type = 'u';
+ else
+ SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos));
+ }
+ }
+ else if (fields_desc[SCM_SYMBOL_LENGTH (layout) - 1] != 'O')
+ field_type = fields_desc[SCM_SYMBOL_LENGTH (layout) - 2];
+ else
+ SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos));
+
+ switch (field_type)
+ {
+ case 'u':
+ answer = scm_ulong2num (data[p]);
+ break;
+
+#if 0
+ case 'i':
+ answer = scm_long2num (data[p]);
+ break;
+
+ case 'd':
+ answer = scm_make_real (*((double *)&(data[p])));
+ break;
+#endif
+
+ case 's':
+ case 'p':
+ answer = SCM_PACK (data[p]);
+ break;
+
+
+ default:
+ SCM_MISC_ERROR ("unrecognized field type: ~S",
+ scm_list_1 (SCM_MAKE_CHAR (field_type)));
+ }
+
+ return answer;
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_struct_set_x, "struct-set!", 3, 0, 0,
+ (SCM handle, SCM pos, SCM val),
+ "Set the slot of the structure @var{handle} with index @var{pos}\n"
+ "to @var{val}. Signal an error if the slot can not be written\n"
+ "to.")
+#define FUNC_NAME s_scm_struct_set_x
+{
+ scm_t_bits * data;
+ SCM layout;
+ int p;
+ int n_fields;
+ char * fields_desc;
+ char field_type = 0;
+
+ SCM_VALIDATE_STRUCT (1, handle);
+ SCM_VALIDATE_INUM (2, pos);
+
+ layout = SCM_STRUCT_LAYOUT (handle);
+ data = SCM_STRUCT_DATA (handle);
+ p = SCM_INUM (pos);
+
+ fields_desc = SCM_SYMBOL_CHARS (layout);
+ n_fields = data[scm_struct_i_n_words];
+
+ SCM_ASSERT_RANGE (1, pos, p < n_fields);
+
+ if (p * 2 < SCM_SYMBOL_LENGTH (layout))
+ {
+ char set_x;
+ field_type = fields_desc[p * 2];
+ set_x = fields_desc [p * 2 + 1];
+ if (set_x != 'w')
+ SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos));
+ }
+ else if (fields_desc[SCM_SYMBOL_LENGTH (layout) - 1] == 'W')
+ field_type = fields_desc[SCM_SYMBOL_LENGTH (layout) - 2];
+ else
+ SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos));
+
+ switch (field_type)
+ {
+ case 'u':
+ data[p] = SCM_NUM2ULONG (3, val);
+ break;
+
+#if 0
+ case 'i':
+ data[p] = SCM_NUM2LONG (3, val);
+ break;
+
+ case 'd':
+ *((double *)&(data[p])) = scm_num2dbl (val, (char *)SCM_ARG3);
+ break;
+#endif
+
+ case 'p':
+ data[p] = SCM_UNPACK (val);
+ break;
+
+ case 's':
+ SCM_MISC_ERROR ("self fields immutable", SCM_EOL);
+
+ default:
+ SCM_MISC_ERROR ("unrecognized field type: ~S",
+ scm_list_1 (SCM_MAKE_CHAR (field_type)));
+ }
+
+ return val;
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_struct_vtable, "struct-vtable", 1, 0, 0,
+ (SCM handle),
+ "Return the vtable structure that describes the type of @var{struct}.")
+#define FUNC_NAME s_scm_struct_vtable
+{
+ SCM_VALIDATE_STRUCT (1, handle);
+ return SCM_STRUCT_VTABLE (handle);
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_struct_vtable_tag, "struct-vtable-tag", 1, 0, 0,
+ (SCM handle),
+ "Return the vtable tag of the structure @var{handle}.")
+#define FUNC_NAME s_scm_struct_vtable_tag
+{
+ SCM_VALIDATE_VTABLE (1, handle);
+ return scm_long2num ((long) SCM_STRUCT_DATA (handle) >> 3);
+}
+#undef FUNC_NAME
+
+/* {Associating names and classes with vtables}
+ *
+ * The name of a vtable should probably be stored as a slot. This is
+ * a backward compatible solution until agreement has been achieved on
+ * how to associate names with vtables.
+ */
+
+unsigned long
+scm_struct_ihashq (SCM obj, unsigned long n)
+{
+ /* The length of the hash table should be a relative prime it's not
+ necessary to shift down the address. */
+ return SCM_UNPACK (obj) % n;
+}
+
+SCM
+scm_struct_create_handle (SCM obj)
+{
+ SCM handle = scm_hash_fn_create_handle_x (scm_struct_table,
+ obj,
+ SCM_BOOL_F,
+ scm_struct_ihashq,
+ scm_sloppy_assq,
+ 0);
+ if (SCM_FALSEP (SCM_CDR (handle)))
+ SCM_SETCDR (handle, scm_cons (SCM_BOOL_F, SCM_BOOL_F));
+ return handle;
+}
+
+SCM_DEFINE (scm_struct_vtable_name, "struct-vtable-name", 1, 0, 0,
+ (SCM vtable),
+ "Return the name of the vtable @var{vtable}.")
+#define FUNC_NAME s_scm_struct_vtable_name
+{
+ SCM_VALIDATE_VTABLE (1, vtable);
+ return SCM_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable)));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_set_struct_vtable_name_x, "set-struct-vtable-name!", 2, 0, 0,
+ (SCM vtable, SCM name),
+ "Set the name of the vtable @var{vtable} to @var{name}.")
+#define FUNC_NAME s_scm_set_struct_vtable_name_x
+{
+ SCM_VALIDATE_VTABLE (1, vtable);
+ SCM_VALIDATE_SYMBOL (2, name);
+ SCM_SET_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable)),
+ name);
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+
+\f
+
+void
+scm_print_struct (SCM exp, SCM port, scm_print_state *pstate)
+{
+ if (SCM_NFALSEP (scm_procedure_p (SCM_STRUCT_PRINTER (exp))))
+ scm_printer_apply (SCM_STRUCT_PRINTER (exp), exp, port, pstate);
+ else
+ {
+ SCM vtable = SCM_STRUCT_VTABLE (exp);
+ SCM name = scm_struct_vtable_name (vtable);
+ scm_puts ("#<", port);
+ if (SCM_NFALSEP (name))
+ scm_display (name, port);
+ else
+ scm_puts ("struct", port);
+ scm_putc (' ', port);
+ scm_intprint (SCM_UNPACK (vtable), 16, port);
+ scm_putc (':', port);
+ scm_intprint (SCM_UNPACK (exp), 16, port);
+ scm_putc ('>', port);
+ }
+}
+
+void
+scm_struct_prehistory ()
+{
+ scm_c_hook_add (&scm_before_mark_c_hook, scm_struct_gc_init, 0, 0);
+ scm_c_hook_add (&scm_after_sweep_c_hook, scm_free_structs, 0, 0);
+}
+
+void
+scm_init_struct ()
+{
+ scm_struct_table
+ = scm_permanent_object (scm_make_weak_key_hash_table (SCM_MAKINUM (31)));
+ required_vtable_fields = scm_makfrom0str ("prsrpw");
+ scm_permanent_object (required_vtable_fields);
+ scm_c_define ("vtable-index-layout", SCM_MAKINUM (scm_vtable_index_layout));
+ scm_c_define ("vtable-index-vtable", SCM_MAKINUM (scm_vtable_index_vtable));
+ scm_c_define ("vtable-index-printer",
+ SCM_MAKINUM (scm_vtable_index_printer));
+ scm_c_define ("vtable-offset-user", SCM_MAKINUM (scm_vtable_offset_user));
+#include "libguile/struct.x"
+}
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/