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_entity_p, "entity?", 1, 0, 0, scm_entity_p);
  60
  61 SCM
  62 scm_entity_p (SCM obj)
  63 {
  64   return (SCM_NIMP (obj) && SCM_STRUCTP (obj) && SCM_I_ENTITYP (obj)
  65           ? SCM_BOOL_T
  66           : SCM_BOOL_F);
  67 }
  68
  69 SCM_PROC (s_set_object_procedure_x, "set-object-procedure!", 1, 0, 1, scm_set_object_procedure_x);
  70
  71 SCM
  72 scm_set_object_procedure_x (SCM obj, SCM procs)
  73 {
  74   SCM proc[4], *pp, p, setp, arity;
  75   int i, a, r;
  76   SCM_ASSERT (SCM_NIMP (obj) && SCM_STRUCTP (obj)
  77               && ((SCM_CLASS_FLAGS (obj) & SCM_CLASSF_OPERATOR)
  78                   || SCM_I_ENTITYP (obj)),
  79               obj,
  80               SCM_ARG1,
  81               s_set_object_procedure_x);
  82   for (i = 0; i < 4; ++i)
  83     proc[i] = SCM_BOOL_F;
  84   i = 0;
  85   while (SCM_NIMP (procs))
  86     {
  87       if (i == 4)
  88         scm_wrong_num_args (scm_makfrom0str (s_set_object_procedure_x));
  89       p = SCM_CAR (procs);
  90       setp = 0;
  91       SCM_ASSERT (SCM_NIMP (p), p, SCM_ARG2 + i, s_set_object_procedure_x);
  92       if (SCM_CLOSUREP (p))
  93         {
  94           arity = scm_procedure_property (p, scm_sym_arity);
  95           a = SCM_INUM (SCM_CAR (arity));
  96           /* Closures have zero optional args */
  97           r = SCM_NFALSEP (SCM_CADDR (arity));
  98           if (a == 1 || (a <= 1 && r))
  99             {
 100               if (SCM_NFALSEP (proc[0]))
 101                 goto ambiguous;
 102               proc[0] = setp = p;
 103             }
 104           if (a == 2 || (a <= 2 && r))
 105             {
 106               if (SCM_NFALSEP (proc[1]))
 107                 goto ambiguous;
 108               proc[1] = setp = p;
 109             }
 110           if (a == 3 || (a <= 3 && r))
 111             {
 112               if (SCM_NFALSEP (proc[2]))
 113                 goto ambiguous;
 114               proc[2] = setp = p;
 115             }
 116           if (a <= 4 && r)
 117             {
 118               if (SCM_NFALSEP (proc[3]))
 119                 goto ambiguous;
 120               proc[3] = setp = p;
 121             }
 122         }
 123       else if (SCM_TYP7 (p) == scm_tc7_subr_1)
 124         {
 125           if (SCM_NFALSEP (proc[0]))
 126             goto ambiguous;
 127           proc[0] = setp = p;
 128         }
 129       else if (SCM_TYP7 (p) == scm_tc7_subr_2)
 130         {
 131           if (SCM_NFALSEP (proc[1]))
 132             goto ambiguous;
 133           proc[1] = setp = p;
 134         }
 135       else if (SCM_TYP7 (p) == scm_tc7_subr_3)
 136         {
 137           if (SCM_NFALSEP (proc[2]))
 138             goto ambiguous;
 139           proc[2] = setp = p;
 140         }
 141       else if (SCM_TYP7 (p) == scm_tc7_lsubr_2)
 142         {
 143           if (SCM_NFALSEP (proc[3]))
 144             {
 145             ambiguous:
 146               SCM_ASSERT (0, p, "Ambiguous procedure arities",
 147                           s_set_object_procedure_x);
 148             }
 149           proc[3] = setp = p;
 150         }
 151       SCM_ASSERT (setp, p, SCM_ARG2 + i, s_set_object_procedure_x);
 152       ++i;
 153       procs = SCM_CDR (procs);
 154     }
 155   pp = (SCM_I_ENTITYP (obj)
 156         ? &SCM_ENTITY_PROC_0 (obj)
 157         : &SCM_OPERATOR_CLASS (obj)->proc0);
 158   for (i = 0; i < 4; ++i)
 159     *pp++ = proc[i];
 160   return SCM_UNSPECIFIED;
 161 }
 162
 163 SCM
 164 scm_i_make_class_object (SCM meta,
 165                          SCM layout_string,
 166                          unsigned long flags)
 167 {
 168   SCM c;
 169   SCM layout = scm_make_struct_layout (layout_string);
 170   c = scm_make_struct (meta,
 171                        SCM_INUM0,
 172                        SCM_LIST4 (layout, SCM_BOOL_F, SCM_EOL, SCM_EOL));
 173   SCM_SET_CLASS_FLAGS (c, flags);
 174   return c;
 175 }
 176
 177 SCM_PROC (s_make_class_object, "make-class-object", 2, 0, 0, scm_make_class_object);
 178
 179 SCM
 180 scm_make_class_object (SCM metaclass, SCM layout)
 181 {
 182   unsigned long flags = 0;
 183   SCM_ASSERT (SCM_NIMP (metaclass) && SCM_STRUCTP (metaclass),
 184               metaclass, SCM_ARG1, s_make_class_object);
 185   SCM_ASSERT (SCM_NIMP (layout) && SCM_STRINGP (layout),
 186               layout, SCM_ARG2, s_make_class_object);
 187   if (metaclass == scm_metaclass_operator)
 188     flags = SCM_CLASSF_OPERATOR;
 189   return scm_i_make_class_object (metaclass, layout, flags);
 190 }
 191
 192 SCM_PROC (s_make_subclass_object, "make-subclass-object", 2, 0, 0, scm_make_subclass_object);
 193
 194 SCM
 195 scm_make_subclass_object (SCM class, SCM layout)
 196 {
 197   SCM pl;
 198   SCM_ASSERT (SCM_NIMP (class) && SCM_STRUCTP (class),
 199               class,
 200               SCM_ARG1,
 201               s_make_subclass_object);
 202   SCM_ASSERT (SCM_NIMP (layout) && SCM_STRINGP (layout),
 203               layout,
 204               SCM_ARG2,
 205               s_make_subclass_object);
 206   pl = SCM_STRUCT_DATA (class)[scm_vtable_index_layout];
 207   /* Convert symbol->string */
 208   pl = scm_makfromstr (SCM_CHARS (pl), (scm_sizet) SCM_LENGTH (pl), 0);
 209   return scm_i_make_class_object (SCM_STRUCT_VTABLE (class),
 210                                   scm_string_append (SCM_LIST2 (pl, layout)),
 211                                   SCM_CLASS_FLAGS (class));
 212 }
 213
 214 void
 215 scm_init_objects ()
 216 {
 217   SCM ms = scm_makfrom0str (SCM_METACLASS_STANDARD_LAYOUT);
 218   SCM ml = scm_make_struct_layout (ms);
 219   SCM mt = scm_make_vtable_vtable (ml, SCM_INUM0,
 220                                    SCM_LIST3 (SCM_BOOL_F, SCM_EOL, SCM_EOL));
 221
 222   SCM os = scm_makfrom0str (SCM_METACLASS_OPERATOR_LAYOUT);
 223   SCM ol = scm_make_struct_layout (os);
 224   SCM ot = scm_make_vtable_vtable (ol, SCM_INUM0,
 225                                    SCM_LIST3 (SCM_BOOL_F, SCM_EOL, SCM_EOL));
 226
 227   SCM es = scm_makfrom0str (SCM_ENTITY_LAYOUT);
 228   SCM el = scm_make_struct_layout (es);
 229   SCM et = scm_make_struct (mt, SCM_INUM0,
 230                             SCM_LIST4 (el, SCM_BOOL_F, SCM_EOL, SCM_EOL));
 231
 232   scm_sysintern ("<class>", mt);
 233   scm_metaclass_standard = mt;
 234   scm_sysintern ("<operator-class>", ot);
 235   scm_metaclass_operator = ot;
 236   SCM_SET_CLASS_FLAGS (et, SCM_CLASSF_OPERATOR | SCM_CLASSF_ENTITY);
 237   scm_sysintern ("<entity>", et);
 238
 239 #include "objects.x"
 240 }