libguile/procprop.c

   1 /* Copyright (C) 1995,1996,1998,2000,2001 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 "libguile/_scm.h"
  48
  49 #include "libguile/alist.h"
  50 #include "libguile/eval.h"
  51 #include "libguile/procs.h"
  52 #include "libguile/gsubr.h"
  53 #include "libguile/objects.h"
  54 #include "libguile/smob.h"
  55 #include "libguile/root.h"
  56 #include "libguile/vectors.h"
  57
  58 #include "libguile/validate.h"
  59 #include "libguile/procprop.h"
  60 \f
  61
  62 SCM_GLOBAL_SYMBOL (scm_sym_system_procedure, "system-procedure");
  63 SCM_GLOBAL_SYMBOL (scm_sym_arity, "arity");
  64
  65 SCM
  66 scm_i_procedure_arity (SCM proc)
  67 {
  68   int a = 0, o = 0, r = 0;
  69   if (SCM_IMP (proc))
  70     return SCM_BOOL_F;
  71  loop:
  72   switch (SCM_TYP7 (proc))
  73     {
  74     case scm_tc7_subr_1o:
  75       o = 1;
  76     case scm_tc7_subr_0:
  77       break;
  78     case scm_tc7_subr_2o:
  79       o = 1;
  80     case scm_tc7_subr_1:
  81     case scm_tc7_cxr:
  82       a += 1;
  83       break;
  84     case scm_tc7_subr_2:
  85       a += 2;
  86       break;
  87     case scm_tc7_subr_3:
  88       a += 3;
  89       break;
  90     case scm_tc7_asubr:
  91     case scm_tc7_rpsubr:
  92     case scm_tc7_lsubr:
  93       r = 1;
  94       break;
  95     case scm_tc7_lsubr_2:
  96       a += 2;
  97       r = 1;
  98       break;
  99     case scm_tc7_smob:
 100       if (SCM_SMOB_APPLICABLE_P (proc))
 101         {
 102           int type = SCM_SMOB_DESCRIPTOR (proc).gsubr_type;
 103           a += SCM_GSUBR_REQ (type);
 104           o = SCM_GSUBR_OPT (type);
 105           r = SCM_GSUBR_REST (type);
 106           break;
 107         }
 108       else
 109         {
 110           return SCM_BOOL_F;
 111         }
 112     case scm_tc7_cclo:
 113       if (SCM_EQ_P (SCM_CCLO_SUBR (proc), scm_f_gsubr_apply))
 114         {
 115           int type = SCM_INUM (SCM_GSUBR_TYPE (proc));
 116           a += SCM_GSUBR_REQ (type);
 117           o = SCM_GSUBR_OPT (type);
 118           r = SCM_GSUBR_REST (type);
 119           break;
 120         }
 121       else
 122         {
 123           proc = SCM_CCLO_SUBR (proc);
 124           a -= 1;
 125           goto loop;
 126         }
 127     case scm_tc7_pws:
 128       proc = SCM_PROCEDURE (proc);
 129       goto loop;
 130     case scm_tcs_closures:
 131       proc = SCM_CLOSURE_FORMALS (proc);
 132       if (SCM_NULLP (proc))
 133         break;
 134       while (SCM_CONSP (proc))
 135         {
 136           ++a;
 137           proc = SCM_CDR (proc);
 138         }
 139       if (!SCM_NULLP (proc))
 140         r = 1;
 141       break;
 142     case scm_tcs_cons_gloc:
 143       if (SCM_OBJ_CLASS_FLAGS (proc) & SCM_CLASSF_PURE_GENERIC)
 144         {
 145           r = 1;
 146           break;
 147         }
 148       else if (!SCM_I_OPERATORP (proc))
 149         return SCM_BOOL_F;
 150       proc = (SCM_I_ENTITYP (proc)
 151               ? SCM_ENTITY_PROCEDURE (proc)
 152               : SCM_OPERATOR_PROCEDURE (proc));
 153       a -= 1;
 154       goto loop;
 155     default:
 156       return SCM_BOOL_F;
 157     }
 158   return scm_list_3 (SCM_MAKINUM (a), SCM_MAKINUM (o), SCM_BOOL(r));
 159 }
 160
 161 static SCM
 162 scm_stand_in_scm_proc(SCM proc)
 163 {
 164   SCM answer;
 165   answer = scm_assoc (proc, scm_stand_in_procs);
 166   if (SCM_FALSEP (answer))
 167     {
 168       answer = scm_closure (scm_list_2 (SCM_EOL, SCM_BOOL_F), SCM_EOL);
 169       scm_stand_in_procs = scm_acons (proc, answer, scm_stand_in_procs);
 170     }
 171   else
 172     answer = SCM_CDR (answer);
 173   return answer;
 174 }
 175
 176 SCM_DEFINE (scm_procedure_properties, "procedure-properties", 1, 0, 0,
 177            (SCM proc),
 178             "Return @var{obj}'s property list.")
 179 #define FUNC_NAME s_scm_procedure_properties
 180 {
 181   SCM_VALIDATE_PROC (1,proc);
 182   return scm_acons (scm_sym_arity, scm_i_procedure_arity (proc),
 183                     SCM_PROCPROPS (SCM_CLOSUREP (proc)
 184                                    ? proc
 185                                    : scm_stand_in_scm_proc (proc)));
 186 }
 187 #undef FUNC_NAME
 188
 189 SCM_DEFINE (scm_set_procedure_properties_x, "set-procedure-properties!", 2, 0, 0,
 190            (SCM proc, SCM new_val),
 191             "Set @var{obj}'s property list to @var{alist}.")
 192 #define FUNC_NAME s_scm_set_procedure_properties_x
 193 {
 194   if (!SCM_CLOSUREP (proc))
 195     proc = scm_stand_in_scm_proc(proc);
 196   SCM_VALIDATE_CLOSURE (1,proc);
 197   SCM_SETPROCPROPS (proc, new_val);
 198   return SCM_UNSPECIFIED;
 199 }
 200 #undef FUNC_NAME
 201
 202 SCM_DEFINE (scm_procedure_property, "procedure-property", 2, 0, 0,
 203            (SCM p, SCM k),
 204             "Return the property of @var{obj} with name @var{key}.")
 205 #define FUNC_NAME s_scm_procedure_property
 206 {
 207   SCM assoc;
 208   if (SCM_EQ_P (k, scm_sym_arity))
 209     {
 210       SCM arity;
 211       SCM_ASSERT (SCM_NFALSEP (arity = scm_i_procedure_arity (p)),
 212                   p, SCM_ARG1, FUNC_NAME);
 213       return arity;
 214     }
 215   SCM_VALIDATE_PROC (1,p);
 216   assoc = scm_sloppy_assq (k,
 217                            SCM_PROCPROPS (SCM_CLOSUREP (p)
 218                                           ? p
 219                                           : scm_stand_in_scm_proc (p)));
 220   return (SCM_NIMP (assoc) ? SCM_CDR (assoc) : SCM_BOOL_F);
 221 }
 222 #undef FUNC_NAME
 223
 224 SCM_DEFINE (scm_set_procedure_property_x, "set-procedure-property!", 3, 0, 0,
 225            (SCM p, SCM k, SCM v),
 226             "In @var{obj}'s property list, set the property named @var{key} to\n"
 227             "@var{value}.")
 228 #define FUNC_NAME s_scm_set_procedure_property_x
 229 {
 230   SCM assoc;
 231   if (!SCM_CLOSUREP (p))
 232     p = scm_stand_in_scm_proc(p);
 233   SCM_VALIDATE_CLOSURE (1,p);
 234   if (SCM_EQ_P (k, scm_sym_arity))
 235     SCM_MISC_ERROR ("arity is a read-only property", SCM_EOL);
 236   assoc = scm_sloppy_assq (k, SCM_PROCPROPS (p));
 237   if (SCM_NIMP (assoc))
 238     SCM_SETCDR (assoc, v);
 239   else
 240     SCM_SETPROCPROPS (p, scm_acons (k, v, SCM_PROCPROPS (p)));
 241   return SCM_UNSPECIFIED;
 242 }
 243 #undef FUNC_NAME
 244
 245 \f
 246
 247
 248 void
 249 scm_init_procprop ()
 250 {
 251 #ifndef SCM_MAGIC_SNARFER
 252 #include "libguile/procprop.x"
 253 #endif
 254 }
 255
 256
 257 /*
 258   Local Variables:
 259   c-file-style: "gnu"
 260   End:
 261 */