libguile/procprop.c

   1 /*      Copyright (C) 1995,1996,1998, 2000 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
  42 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
  43    gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
  44
  45 \f
  46
  47 #include <stdio.h>
  48 #include "libguile/_scm.h"
  49
  50 #include "libguile/alist.h"
  51 #include "libguile/eval.h"
  52 #include "libguile/procs.h"
  53 #include "libguile/gsubr.h"
  54 #include "libguile/objects.h"
  55 #include "libguile/smob.h"
  56 #include "libguile/root.h"
  57 #include "libguile/vectors.h"
  58
  59 #include "libguile/validate.h"
  60 #include "libguile/procprop.h"
  61 \f
  62
  63 SCM_GLOBAL_SYMBOL (scm_sym_system_procedure, "system-procedure");
  64 SCM_GLOBAL_SYMBOL (scm_sym_arity, "arity");
  65
  66 SCM
  67 scm_i_procedure_arity (SCM proc)
  68 {
  69   int a = 0, o = 0, r = 0;
  70   if (SCM_IMP (proc))
  71     return SCM_BOOL_F;
  72  loop:
  73   switch (SCM_TYP7 (proc))
  74     {
  75     case scm_tc7_subr_1o:
  76       o = 1;
  77     case scm_tc7_subr_0:
  78       break;
  79     case scm_tc7_subr_2o:
  80       o = 1;
  81     case scm_tc7_subr_1:
  82     case scm_tc7_cxr:
  83       a += 1;
  84       break;
  85     case scm_tc7_subr_2:
  86       a += 2;
  87       break;
  88     case scm_tc7_subr_3:
  89       a += 3;
  90       break;
  91     case scm_tc7_asubr:
  92     case scm_tc7_rpsubr:
  93     case scm_tc7_lsubr:
  94       r = 1;
  95       break;
  96     case scm_tc7_lsubr_2:
  97       a += 2;
  98       r = 1;
  99       break;
 100     case scm_tc7_smob:
 101       if (SCM_SMOB_APPLICABLE_P (proc))
 102         {
 103           int type = SCM_SMOB_DESCRIPTOR (proc).gsubr_type;
 104           a += SCM_GSUBR_REQ (type);
 105           o = SCM_GSUBR_OPT (type);
 106           r = SCM_GSUBR_REST (type);
 107           break;
 108         }
 109       else
 110         {
 111           return SCM_BOOL_F;
 112         }
 113     case scm_tc7_cclo:
 114       if (SCM_EQ_P (SCM_CCLO_SUBR (proc), scm_f_gsubr_apply))
 115         {
 116           int type = SCM_INUM (SCM_GSUBR_TYPE (proc));
 117           a += SCM_GSUBR_REQ (type);
 118           o = SCM_GSUBR_OPT (type);
 119           r = SCM_GSUBR_REST (type);
 120           break;
 121         }
 122       else
 123         {
 124           proc = SCM_CCLO_SUBR (proc);
 125           a -= 1;
 126           goto loop;
 127         }
 128     case scm_tc7_pws:
 129       proc = SCM_PROCEDURE (proc);
 130       goto loop;
 131     case scm_tcs_closures:
 132       proc = SCM_CAR (SCM_CODE (proc));
 133       if (SCM_IMP (proc))
 134         break;
 135       while (SCM_CONSP (proc))
 136         {
 137           ++a;
 138           proc = SCM_CDR (proc);
 139         }
 140       if (SCM_NIMP (proc))
 141         r = 1;
 142       break;
 143     case scm_tcs_cons_gloc:
 144       if (SCM_OBJ_CLASS_FLAGS (proc) & SCM_CLASSF_PURE_GENERIC)
 145         {
 146           r = 1;
 147           break;
 148         }
 149       else if (!SCM_I_OPERATORP (proc))
 150         return SCM_BOOL_F;
 151       proc = (SCM_I_ENTITYP (proc)
 152               ? SCM_ENTITY_PROCEDURE (proc)
 153               : SCM_OPERATOR_PROCEDURE (proc));
 154       a -= 1;
 155       goto loop;
 156     default:
 157       return SCM_BOOL_F;
 158     }
 159   return SCM_LIST3 (SCM_MAKINUM (a),
 160                     SCM_MAKINUM (o),
 161                     SCM_BOOL(r));
 162 }
 163
 164 static SCM
 165 scm_stand_in_scm_proc(SCM proc)
 166 {
 167   SCM answer;
 168   answer = scm_assoc (proc, scm_stand_in_procs);
 169   if (SCM_FALSEP (answer))
 170     {
 171       answer = scm_closure (scm_listify (SCM_EOL, SCM_BOOL_F, SCM_UNDEFINED),
 172                             SCM_EOL);
 173       scm_stand_in_procs = scm_cons (scm_cons (proc, answer),
 174                                      scm_stand_in_procs);
 175     }
 176   else
 177     answer = SCM_CDR (answer);
 178   return answer;
 179 }
 180
 181 SCM_DEFINE (scm_procedure_properties, "procedure-properties", 1, 0, 0,
 182            (SCM proc),
 183             "Return @var{obj}'s property list.")
 184 #define FUNC_NAME s_scm_procedure_properties
 185 {
 186   SCM_VALIDATE_PROC (1,proc);
 187   return scm_acons (scm_sym_arity, scm_i_procedure_arity (proc),
 188                     SCM_PROCPROPS (SCM_CLOSUREP (proc)
 189                                    ? proc
 190                                    : scm_stand_in_scm_proc (proc)));
 191 }
 192 #undef FUNC_NAME
 193
 194 SCM_DEFINE (scm_set_procedure_properties_x, "set-procedure-properties!", 2, 0, 0,
 195            (SCM proc, SCM new_val),
 196             "Set @var{obj}'s property list to @var{alist}.")
 197 #define FUNC_NAME s_scm_set_procedure_properties_x
 198 {
 199   if (!SCM_CLOSUREP (proc))
 200     proc = scm_stand_in_scm_proc(proc);
 201   SCM_VALIDATE_CLOSURE (1,proc);
 202   SCM_SETPROCPROPS (proc, new_val);
 203   return SCM_UNSPECIFIED;
 204 }
 205 #undef FUNC_NAME
 206
 207 SCM_DEFINE (scm_procedure_property, "procedure-property", 2, 0, 0,
 208            (SCM p, SCM k),
 209             "Return the property of @var{obj} with name @var{key}.")
 210 #define FUNC_NAME s_scm_procedure_property
 211 {
 212   SCM assoc;
 213   if (SCM_EQ_P (k, scm_sym_arity))
 214     {
 215       SCM arity;
 216       SCM_ASSERT (SCM_NFALSEP (arity = scm_i_procedure_arity (p)),
 217                   p, SCM_ARG1, FUNC_NAME);
 218       return arity;
 219     }
 220   SCM_VALIDATE_PROC (1,p);
 221   assoc = scm_sloppy_assq (k,
 222                            SCM_PROCPROPS (SCM_CLOSUREP (p)
 223                                           ? p
 224                                           : scm_stand_in_scm_proc (p)));
 225   return (SCM_NIMP (assoc) ? SCM_CDR (assoc) : SCM_BOOL_F);
 226 }
 227 #undef FUNC_NAME
 228
 229 SCM_DEFINE (scm_set_procedure_property_x, "set-procedure-property!", 3, 0, 0,
 230            (SCM p, SCM k, SCM v),
 231             "In @var{obj}'s property list, set the property named @var{key} to\n"
 232             "@var{value}.")
 233 #define FUNC_NAME s_scm_set_procedure_property_x
 234 {
 235   SCM assoc;
 236   if (!SCM_CLOSUREP (p))
 237     p = scm_stand_in_scm_proc(p);
 238   SCM_VALIDATE_CLOSURE (1,p);
 239   if (SCM_EQ_P (k, scm_sym_arity))
 240     SCM_MISC_ERROR ("arity is a read-only property", SCM_EOL);
 241   assoc = scm_sloppy_assq (k, SCM_PROCPROPS (p));
 242   if (SCM_NIMP (assoc))
 243     SCM_SETCDR (assoc, v);
 244   else
 245     SCM_SETPROCPROPS (p, scm_acons (k, v, SCM_PROCPROPS (p)));
 246   return SCM_UNSPECIFIED;
 247 }
 248 #undef FUNC_NAME
 249
 250 \f
 251
 252
 253 void
 254 scm_init_procprop ()
 255 {
 256 #ifndef SCM_MAGIC_SNARFER
 257 #include "libguile/procprop.x"
 258 #endif
 259 }
 260
 261
 262 /*
 263   Local Variables:
 264   c-file-style: "gnu"
 265   End:
 266 */