libguile/objects.c

   1 /*      Copyright (C) 1995,1996 Free Software Foundation, Inc.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2, or (at your option)
   6  * any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this software; see the file COPYING.  If not, write to
  15  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  16  * Boston, MA 02111-1307 USA
  17  *
  18  * As a special exception, the Free Software Foundation gives permission
  19  * for additional uses of the text contained in its release of GUILE.
  20  *
  21  * The exception is that, if you link the GUILE library with other files
  22  * to produce an executable, this does not by itself cause the
  23  * resulting executable to be covered by the GNU General Public License.
  24  * Your use of that executable is in no way restricted on account of
  25  * linking the GUILE library code into it.
  26  *
  27  * This exception does not however invalidate any other reasons why
  28  * the executable file might be covered by the GNU General Public License.
  29  *
  30  * This exception applies only to the code released by the
  31  * Free Software Foundation under the name GUILE.  If you copy
  32  * code from other Free Software Foundation releases into a copy of
  33  * GUILE, as the General Public License permits, the exception does
  34  * not apply to the code that you add in this way.  To avoid misleading
  35  * anyone as to the status of such modified files, you must delete
  36  * this exception notice from them.
  37  *
  38  * If you write modifications of your own for GUILE, it is your choice
  39  * whether to permit this exception to apply to your modifications.
  40  * If you do not wish that, delete this exception notice.  */
  41 \f
  42
  43 /* This file and objects.h contains those minimal pieces of the Guile
  44  * Object Oriented Programming System which need to be included in
  45  * libguile.  See the comments in objects.h.
  46  */
  47
  48 #include "_scm.h"
  49
  50 #include "struct.h"
  51 #include "procprop.h"
  52
  53 #include "objects.h"
  54 \f
  55
  56 SCM scm_metaclass_standard;
  57 SCM scm_metaclass_operator;
  58
  59 SCM_PROC (s_set_object_procedure_x, "set-object-procedure!", 1, 0, 1, scm_set_object_procedure_x);
  60
  61 SCM
  62 scm_set_object_procedure_x (SCM obj, SCM procs)
  63 {
  64   SCM proc[4], *pp, p, setp, arity;
  65   int i, a, r;
  66   SCM_ASSERT (SCM_NIMP (obj) && SCM_STRUCTP (obj)
  67               && ((SCM_CLASS_FLAGS (obj) | SCM_CLASSF_OPERATOR)
  68                   || SCM_I_ENTITYP (obj)),
  69               obj,
  70               SCM_ARG1,
  71               s_set_object_procedure_x);
  72   for (i = 0; i < 4; ++i)
  73     proc[i] = SCM_BOOL_F;
  74   i = 0;
  75   while (SCM_NIMP (procs))
  76     {
  77       if (i == 4)
  78         scm_wrong_num_args (scm_makfrom0str (s_set_object_procedure_x));
  79       p = SCM_CAR (procs);
  80       setp = 0;
  81       SCM_ASSERT (SCM_NIMP (p), p, SCM_ARG2 + i, s_set_object_procedure_x);
  82       if (SCM_CLOSUREP (p))
  83         {
  84           arity = scm_procedure_property (p, scm_sym_arity);
  85           a = SCM_INUM (SCM_CAR (arity));
  86           /* Closures have zero optional args */
  87           r = SCM_NFALSEP (SCM_CADDR (arity));
  88           if (a == 1 || (a <= 1 && r))
  89             {
  90               if (SCM_NFALSEP (proc[0]))
  91                 goto ambiguous;
  92               proc[0] = setp = p;
  93             }
  94           if (a == 2 || (a <= 2 && r))
  95             {
  96               if (SCM_NFALSEP (proc[1]))
  97                 goto ambiguous;
  98               proc[1] = setp = p;
  99             }
 100           if (a == 3 || (a <= 3 && r))
 101             {
 102               if (SCM_NFALSEP (proc[2]))
 103                 goto ambiguous;
 104               proc[2] = setp = p;
 105             }
 106           if (a <= 4 && r)
 107             {
 108               if (SCM_NFALSEP (proc[3]))
 109                 goto ambiguous;
 110               proc[3] = setp = p;
 111             }
 112         }
 113       else if (SCM_TYP7 (p) == scm_tc7_subr_1)
 114         {
 115           if (SCM_NFALSEP (proc[0]))
 116             goto ambiguous;
 117           proc[0] = setp = p;
 118         }
 119       else if (SCM_TYP7 (p) == scm_tc7_subr_2)
 120         {
 121           if (SCM_NFALSEP (proc[1]))
 122             goto ambiguous;
 123           proc[1] = setp = p;
 124         }
 125       else if (SCM_TYP7 (p) == scm_tc7_subr_3)
 126         {
 127           if (SCM_NFALSEP (proc[2]))
 128             goto ambiguous;
 129           proc[2] = setp = p;
 130         }
 131       else if (SCM_TYP7 (p) == scm_tc7_lsubr_2)
 132         {
 133           if (SCM_NFALSEP (proc[3]))
 134             {
 135             ambiguous:
 136               SCM_ASSERT (0, p, "Ambiguous procedure arities",
 137                           s_set_object_procedure_x);
 138             }
 139           proc[3] = setp = p;
 140         }
 141       SCM_ASSERT (setp, p, SCM_ARG2 + i, s_set_object_procedure_x);
 142       ++i;
 143       procs = SCM_CDR (procs);
 144     }
 145   pp = (SCM_I_ENTITYP (obj)
 146         ? &SCM_ENTITY_PROC_0 (obj)
 147         : &SCM_OPERATOR_CLASS (obj)->proc0);
 148   for (i = 0; i < 4; ++i)
 149     *pp++ = proc[i];
 150   return SCM_UNSPECIFIED;
 151 }
 152
 153 static SCM
 154 make_class_object (SCM meta,
 155                    SCM pl,
 156                    SCM layout,
 157                    unsigned long flags,
 158                    char* subr)
 159 {
 160   SCM c;
 161   SCM_ASSERT (SCM_NIMP (meta) && SCM_STRUCTP (meta), meta, SCM_ARG1, subr);
 162   SCM_ASSERT (SCM_NIMP (layout) && SCM_STRINGP (layout),
 163               layout,
 164               SCM_ARG2,
 165               subr);
 166   layout = scm_make_struct_layout (scm_string_append (SCM_LIST2 (pl, layout)));
 167   c = scm_make_struct (meta,
 168                        SCM_INUM0,
 169                        SCM_LIST4 (layout, SCM_BOOL_F, SCM_EOL, SCM_EOL));
 170   SCM_SET_CLASS_FLAGS (c, flags);
 171   return c;
 172 }
 173
 174 SCM_PROC (s_make_class_object, "make-class-object", 2, 0, 0, scm_make_class_object);
 175
 176 SCM
 177 scm_make_class_object (SCM metaclass, SCM layout)
 178 {
 179   unsigned long flags = 0;
 180   if (metaclass == scm_metaclass_operator)
 181     flags = SCM_CLASSF_OPERATOR;
 182   return make_class_object (metaclass,
 183                             scm_nullstr,
 184                             layout,
 185                             flags,
 186                             s_make_class_object);
 187 }
 188
 189 SCM_PROC (s_make_subclass_object, "make-subclass-object", 2, 0, 0, scm_make_subclass_object);
 190
 191 SCM
 192 scm_make_subclass_object (SCM class, SCM layout)
 193 {
 194   SCM pl;
 195   SCM_ASSERT (SCM_NIMP (class) && SCM_STRUCTP (class),
 196               class,
 197               SCM_ARG1,
 198               s_make_subclass_object);
 199   pl = SCM_STRUCT_DATA (class)[scm_vtable_index_layout];
 200   pl = scm_makfromstr (SCM_CHARS (pl), (scm_sizet) SCM_LENGTH (pl), 0);
 201   return make_class_object (scm_metaclass_standard,
 202                             pl,
 203                             layout,
 204                             SCM_CLASS_FLAGS (class),
 205                             s_make_subclass_object);
 206 }
 207
 208 void
 209 scm_init_objects ()
 210 {
 211   SCM ms = scm_makfrom0str (SCM_METACLASS_STANDARD_LAYOUT);
 212   SCM ml = scm_make_struct_layout (ms);
 213   SCM mt = scm_make_vtable_vtable (ml, SCM_INUM0,
 214                                    SCM_LIST3 (SCM_BOOL_F, SCM_EOL, SCM_EOL));
 215
 216   SCM os = scm_makfrom0str (SCM_METACLASS_OPERATOR_LAYOUT);
 217   SCM ol = scm_make_struct_layout (os);
 218   SCM ot = scm_make_vtable_vtable (ol, SCM_INUM0,
 219                                    SCM_LIST3 (SCM_BOOL_F, SCM_EOL, SCM_EOL));
 220
 221   SCM es = scm_makfrom0str (SCM_ENTITY_LAYOUT);
 222   SCM el = scm_make_struct_layout (es);
 223   SCM et = scm_make_struct (mt, SCM_INUM0,
 224                             SCM_LIST4 (el, SCM_BOOL_F, SCM_EOL, SCM_EOL));
 225
 226   scm_sysintern ("<standard-metaclass>", mt);
 227   scm_metaclass_standard = mt;
 228   scm_sysintern ("<operator-metaclass>", ot);
 229   scm_metaclass_operator = ot;
 230   SCM_SET_CLASS_FLAGS (et, SCM_CLASSF_OPERATOR | SCM_CLASSF_ENTITY);
 231   scm_sysintern ("<entity-class>", et);
 232
 233 #include "objects.x"
 234 }