libguile/struct.h

   1 /* classes: h_files */
   2
   3 #ifndef STRUCTH
   4 #define STRUCTH
   5 /*      Copyright (C) 1995, 1997 Free Software Foundation, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2, or (at your option)
  10  * any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this software; see the file COPYING.  If not, write to
  19  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20  * Boston, MA 02111-1307 USA
  21  *
  22  * As a special exception, the Free Software Foundation gives permission
  23  * for additional uses of the text contained in its release of GUILE.
  24  *
  25  * The exception is that, if you link the GUILE library with other files
  26  * to produce an executable, this does not by itself cause the
  27  * resulting executable to be covered by the GNU General Public License.
  28  * Your use of that executable is in no way restricted on account of
  29  * linking the GUILE library code into it.
  30  *
  31  * This exception does not however invalidate any other reasons why
  32  * the executable file might be covered by the GNU General Public License.
  33  *
  34  * This exception applies only to the code released by the
  35  * Free Software Foundation under the name GUILE.  If you copy
  36  * code from other Free Software Foundation releases into a copy of
  37  * GUILE, as the General Public License permits, the exception does
  38  * not apply to the code that you add in this way.  To avoid misleading
  39  * anyone as to the status of such modified files, you must delete
  40  * this exception notice from them.
  41  *
  42  * If you write modifications of your own for GUILE, it is your choice
  43  * whether to permit this exception to apply to your modifications.
  44  * If you do not wish that, delete this exception notice.  */
  45 \f
  46
  47 #include "libguile/__scm.h"
  48 #include "libguile/print.h"
  49
  50 \f
  51
  52 /* Number of words with negative index */
  53 #define scm_struct_n_extra_words 3
  54
  55 /* These are how the initial words of a vtable are allocated. */
  56 #define scm_struct_i_ptr        -3 /* start of block (see alloc_struct) */
  57 #define scm_struct_i_n_words    -2 /* How many words allocated to this struct? */
  58 #define scm_struct_i_tag        -1 /* A unique tag for this type.. */
  59 #define scm_vtable_index_layout  0 /* A symbol describing the physical arrangement of this type. */
  60 #define scm_vtable_index_vcell   1 /* An opaque word, managed by the garbage collector.  */
  61 #define scm_vtable_index_vtable  2 /* A pointer to the handle for this vtable. */
  62 #define scm_vtable_index_printer 3 /* A printer for this struct type. */
  63 #define scm_vtable_offset_user   4 /* Where do user fields start? */
  64
  65
  66 #define SCM_STRUCTP(X)                  (SCM_TYP3(X) == scm_tc3_cons_gloc)
  67 #define SCM_STRUCT_DATA(X)              ((SCM*)(SCM_CDR(X)))
  68 #define SCM_STRUCT_VTABLE_DATA(X)       ((SCM *)(SCM_CAR(X) - 1))
  69 #define SCM_STRUCT_LAYOUT(X)            (SCM_STRUCT_VTABLE_DATA(X)[scm_vtable_index_layout])
  70 #define SCM_STRUCT_VTABLE(X)            (SCM_STRUCT_VTABLE_DATA(X)[scm_vtable_index_vtable])
  71 #define SCM_STRUCT_PRINTER(X)           (SCM_STRUCT_VTABLE_DATA(X)[scm_vtable_index_printer])
  72 /* Efficiency is important in the following macro, since it's used in GC */
  73 #define SCM_LAYOUT_TAILP(X)             (((X) & 32) == 0) /* R, W or O */
  74
  75
  76 \f
  77
  78 extern SCM scm_make_struct_layout SCM_P ((SCM fields));
  79 extern SCM scm_struct_p SCM_P ((SCM x));
  80 extern SCM scm_struct_vtable_p SCM_P ((SCM x));
  81 extern SCM scm_make_struct SCM_P ((SCM vtable, SCM tail_array_size, SCM init));
  82 extern SCM scm_make_vtable_vtable SCM_P ((SCM extra_fields, SCM tail_array_size, SCM init));
  83 extern SCM scm_struct_ref SCM_P ((SCM handle, SCM pos));
  84 extern SCM scm_struct_set_x SCM_P ((SCM handle, SCM pos, SCM val));
  85 extern SCM scm_struct_vtable SCM_P ((SCM handle));
  86 extern SCM scm_struct_vtable_tag SCM_P ((SCM handle));
  87 extern void scm_print_struct SCM_P ((SCM exp, SCM port, scm_print_state *));
  88 extern void scm_init_struct SCM_P ((void));
  89
  90 #endif  /* STRUCTH */