--- /dev/null
+/* Copyright (C) 1996,1997,1998,1999,2000,2001, 2003, 2004, 2006, 2007 Free Software Foundation, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+\f
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "libguile/_scm.h"
+#include "libguile/async.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"
+
+#include "libguile/eq.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 */
+ const char * field_desc;
+ size_t len;
+ int x;
+
+ len = scm_i_string_length (fields);
+ if (len % 2 == 1)
+ SCM_MISC_ERROR ("odd length field specification: ~S",
+ scm_list_1 (fields));
+
+ field_desc = scm_i_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_from_int (x / 2)));
+ x += 2;
+ goto recheck_ref;
+ }
+#endif
+ }
+ new_sym = scm_string_to_symbol (fields);
+ }
+ scm_remember_upto_here_1 (fields);
+ return new_sym;
+}
+#undef FUNC_NAME
+
+\f
+
+
+
+static void
+scm_struct_init (SCM handle, SCM layout, scm_t_bits * mem, int tail_elts, SCM inits)
+{
+ unsigned const char *fields_desc =
+ (unsigned const char *) scm_i_symbol_chars (layout) - 2;
+ unsigned char prot = 0;
+ int n_fields = scm_i_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_to_long (SCM_CAR (inits));
+ inits = SCM_CDR (inits);
+ }
+ break;
+#endif
+
+ case 'u':
+ if ((prot != 'r' && prot != 'w') || scm_is_null (inits))
+ *mem = 0;
+ else
+ {
+ *mem = scm_to_ulong (SCM_CAR (inits));
+ inits = SCM_CDR (inits);
+ }
+ break;
+
+ case 'p':
+ if ((prot != 'r' && prot != 'w') || scm_is_null (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_from_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;
+ int tmp;
+
+ if (!SCM_STRUCTP (x))
+ return SCM_BOOL_F;
+
+ layout = SCM_STRUCT_LAYOUT (x);
+
+ if (scm_i_symbol_length (layout)
+ < scm_i_string_length (required_vtable_fields))
+ return SCM_BOOL_F;
+
+ tmp = strncmp (scm_i_symbol_chars (layout),
+ scm_i_string_chars (required_vtable_fields),
+ scm_i_string_length (required_vtable_fields));
+ scm_remember_upto_here_1 (required_vtable_fields);
+ if (tmp)
+ return SCM_BOOL_F;
+
+ mem = SCM_STRUCT_DATA (x);
+
+ return scm_from_bool (scm_is_symbol (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_i_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_i_structs_to_free;
+ do
+ {
+ /* Mark vtables in GC chain. GC mark set means delay freeing. */
+ SCM chain = newchain;
+ while (!scm_is_null (chain))
+ {
+ SCM vtable = SCM_STRUCT_VTABLE (chain);
+ if (SCM_STRUCT_GC_CHAIN (vtable) != 0 && vtable != chain)
+ SCM_SET_GC_MARK (vtable);
+ chain = SCM_STRUCT_GC_CHAIN (chain);
+ }
+ /* Free unmarked structs. */
+ chain = newchain;
+ newchain = SCM_EOL;
+ while (!scm_is_null (chain))
+ {
+ SCM obj = chain;
+ chain = SCM_STRUCT_GC_CHAIN (chain);
+ if (SCM_GC_MARK_P (obj))
+ {
+ SCM_CLEAR_GC_MARK (obj);
+ SCM_SET_STRUCT_GC_CHAIN (obj, newchain);
+ newchain = obj;
+ }
+ else
+ {
+ scm_t_bits * vtable_data = SCM_STRUCT_VTABLE_DATA (obj);
+ 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_is_null (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;
+ size_t basic_size;
+ size_t tail_elts;
+ scm_t_bits * data;
+ SCM handle;
+
+ SCM_VALIDATE_VTABLE (1, vtable);
+ SCM_VALIDATE_REST_ARGUMENT (init);
+
+ layout = SCM_PACK (SCM_STRUCT_DATA (vtable) [scm_vtable_index_layout]);
+ basic_size = scm_i_symbol_length (layout) / 2;
+ tail_elts = scm_to_size_t (tail_array_size);
+
+ /* A tail array is only allowed if the layout fields string ends in "R",
+ "W" or "O". */
+ if (tail_elts != 0)
+ {
+ SCM layout_str, last_char;
+
+ if (basic_size == 0)
+ {
+ bad_tail:
+ SCM_MISC_ERROR ("tail array not allowed unless layout ends R, W, or O", SCM_EOL);
+ }
+
+ layout_str = scm_symbol_to_string (layout);
+ last_char = scm_string_ref (layout_str,
+ scm_from_size_t (2 * basic_size - 1));
+ if (! SCM_LAYOUT_TAILP (SCM_CHAR (last_char)))
+ goto bad_tail;
+ }
+
+ /* In guile 1.8.5 and earlier, everything below was covered by a
+ CRITICAL_SECTION lock. This can lead to deadlocks in garbage
+ collection, since other threads might be holding the heap_mutex, while
+ sleeping on the CRITICAL_SECTION lock. There does not seem to be any
+ need for a lock on the section below, as it does not access or update
+ any globals, so the critical section has been removed. */
+
+ 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);
+
+ 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;
+ size_t basic_size;
+ size_t tail_elts;
+ scm_t_bits *data;
+ SCM handle;
+
+ SCM_VALIDATE_STRING (1, user_fields);
+ 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_i_symbol_length (layout) / 2;
+ tail_elts = scm_to_size_t (tail_array_size);
+ SCM_CRITICAL_SECTION_START;
+ 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_CRITICAL_SECTION_END;
+ return handle;
+}
+#undef FUNC_NAME
+
+
+static SCM scm_i_vtable_vtable_no_extra_fields;
+
+SCM_DEFINE (scm_make_vtable, "make-vtable", 1, 1, 0,
+ (SCM fields, SCM printer),
+ "Create a vtable, for creating structures with the given\n"
+ "@var{fields}.\n"
+ "\n"
+ "The optional @var{printer} argument is a function to be called\n"
+ "@code{(@var{printer} struct port)} on the structures created.\n"
+ "It should look at @var{struct} and write to @var{port}.")
+#define FUNC_NAME s_scm_make_vtable
+{
+ if (SCM_UNBNDP (printer))
+ printer = SCM_BOOL_F;
+
+ return scm_make_struct (scm_i_vtable_vtable_no_extra_fields, SCM_INUM0,
+ scm_list_2 (scm_make_struct_layout (fields),
+ printer));
+}
+#undef FUNC_NAME
+
+
+/* Return true if S1 and S2 are equal structures, i.e., if their vtable and
+ contents are the same. Field protections are honored. Thus, it is an
+ error to test the equality of structures that contain opaque fields. */
+SCM
+scm_i_struct_equalp (SCM s1, SCM s2)
+#define FUNC_NAME "scm_i_struct_equalp"
+{
+ SCM vtable1, vtable2, layout;
+ size_t struct_size, field_num;
+
+ SCM_VALIDATE_STRUCT (1, s1);
+ SCM_VALIDATE_STRUCT (2, s2);
+
+ vtable1 = SCM_STRUCT_VTABLE (s1);
+ vtable2 = SCM_STRUCT_VTABLE (s2);
+
+ if (!scm_is_eq (vtable1, vtable2))
+ return SCM_BOOL_F;
+
+ layout = SCM_STRUCT_LAYOUT (s1);
+ struct_size = scm_i_symbol_length (layout) / 2;
+
+ for (field_num = 0; field_num < struct_size; field_num++)
+ {
+ SCM s_field_num;
+ SCM field1, field2;
+
+ /* We have to use `scm_struct_ref ()' here so that fields are accessed
+ consistently, notably wrt. field types and access rights. */
+ s_field_num = scm_from_size_t (field_num);
+ field1 = scm_struct_ref (s1, s_field_num);
+ field2 = scm_struct_ref (s2, s_field_num);
+
+ /* Self-referencing fields (type `s') must be skipped to avoid infinite
+ recursion. */
+ if (!(scm_is_eq (field1, s1) && (scm_is_eq (field2, s2))))
+ if (scm_is_false (scm_equal_p (field1, field2)))
+ return SCM_BOOL_F;
+ }
+
+ /* FIXME: Tail elements should be tested for equality. */
+
+ return SCM_BOOL_T;
+}
+#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;
+ size_t layout_len;
+ size_t p;
+ scm_t_bits n_fields;
+ const char *fields_desc;
+ char field_type = 0;
+
+
+ SCM_VALIDATE_STRUCT (1, handle);
+
+ layout = SCM_STRUCT_LAYOUT (handle);
+ data = SCM_STRUCT_DATA (handle);
+ p = scm_to_size_t (pos);
+
+ fields_desc = scm_i_symbol_chars (layout);
+ layout_len = scm_i_symbol_length (layout);
+ if (SCM_STRUCT_VTABLE_FLAGS (handle) & SCM_STRUCTF_LIGHT)
+ /* no extra words */
+ n_fields = layout_len / 2;
+ else
+ n_fields = data[scm_struct_i_n_words];
+
+ SCM_ASSERT_RANGE(1, pos, p < n_fields);
+
+ if (p * 2 < layout_len)
+ {
+ 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[layout_len - 1] != 'O')
+ field_type = fields_desc[layout_len - 2];
+ else
+ SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos));
+
+ switch (field_type)
+ {
+ case 'u':
+ answer = scm_from_ulong (data[p]);
+ break;
+
+#if 0
+ case 'i':
+ answer = scm_from_long (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;
+ size_t layout_len;
+ size_t p;
+ int n_fields;
+ const char *fields_desc;
+ char field_type = 0;
+
+ SCM_VALIDATE_STRUCT (1, handle);
+
+ layout = SCM_STRUCT_LAYOUT (handle);
+ data = SCM_STRUCT_DATA (handle);
+ p = scm_to_size_t (pos);
+
+ fields_desc = scm_i_symbol_chars (layout);
+ layout_len = scm_i_symbol_length (layout);
+ if (SCM_STRUCT_VTABLE_FLAGS (handle) & SCM_STRUCTF_LIGHT)
+ /* no extra words */
+ n_fields = layout_len / 2;
+ else
+ n_fields = data[scm_struct_i_n_words];
+
+ SCM_ASSERT_RANGE (1, pos, p < n_fields);
+
+ if (p * 2 < layout_len)
+ {
+ 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[layout_len - 1] == 'W')
+ field_type = fields_desc[layout_len - 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_from_ulong (((unsigned 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_is_false (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_is_true (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_is_true (name))
+ scm_display (name, port);
+ else
+ scm_puts ("struct", port);
+ scm_putc (' ', port);
+ scm_uintprint (SCM_UNPACK (vtable), 16, port);
+ scm_putc (':', port);
+ scm_uintprint (SCM_UNPACK (exp), 16, port);
+ scm_putc ('>', port);
+ }
+}
+
+void
+scm_struct_prehistory ()
+{
+ scm_i_structs_to_free = SCM_EOL;
+ scm_c_hook_add (&scm_before_sweep_c_hook, scm_struct_gc_init, 0, 0);
+ /* With the new lazy sweep GC, the point at which the entire heap is
+ swept is just before the mark phase. */
+ scm_c_hook_add (&scm_before_mark_c_hook, scm_free_structs, 0, 0);
+}
+
+void
+scm_init_struct ()
+{
+ scm_struct_table
+ = scm_permanent_object (scm_make_weak_key_hash_table (scm_from_int (31)));
+ required_vtable_fields = scm_from_locale_string ("prsrpw");
+ scm_permanent_object (required_vtable_fields);
+
+ scm_i_vtable_vtable_no_extra_fields =
+ scm_permanent_object
+ (scm_make_vtable_vtable (scm_nullstr, SCM_INUM0, SCM_EOL));
+
+ scm_c_define ("vtable-index-layout", scm_from_int (scm_vtable_index_layout));
+ scm_c_define ("vtable-index-vtable", scm_from_int (scm_vtable_index_vtable));
+ scm_c_define ("vtable-index-printer",
+ scm_from_int (scm_vtable_index_printer));
+ scm_c_define ("vtable-offset-user", scm_from_int (scm_vtable_offset_user));
+#include "libguile/struct.x"
+}
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/
projects / lilypond.git / blobdiff