libguile/procprop.c

   1 /* Copyright (C) 1995,1996,1998,2000,2001, 2003 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
  43 \f
  44
  45 #include "libguile/_scm.h"
  46
  47 #include "libguile/alist.h"
  48 #include "libguile/eval.h"
  49 #include "libguile/procs.h"
  50 #include "libguile/gsubr.h"
  51 #include "libguile/objects.h"
  52 #include "libguile/smob.h"
  53 #include "libguile/root.h"
  54 #include "libguile/vectors.h"
  55
  56 #include "libguile/validate.h"
  57 #include "libguile/procprop.h"
  58 \f
  59
  60 SCM_GLOBAL_SYMBOL (scm_sym_system_procedure, "system-procedure");
  61 SCM_GLOBAL_SYMBOL (scm_sym_arity, "arity");
  62
  63 SCM
  64 scm_i_procedure_arity (SCM proc)
  65 {
  66   int a = 0, o = 0, r = 0;
  67   if (SCM_IMP (proc))
  68     return SCM_BOOL_F;
  69  loop:
  70   switch (SCM_TYP7 (proc))
  71     {
  72     case scm_tc7_subr_1o:
  73       o = 1;
  74     case scm_tc7_subr_0:
  75       break;
  76     case scm_tc7_subr_2o:
  77       o = 1;
  78     case scm_tc7_subr_1:
  79     case scm_tc7_cxr:
  80       a += 1;
  81       break;
  82     case scm_tc7_subr_2:
  83       a += 2;
  84       break;
  85     case scm_tc7_subr_3:
  86       a += 3;
  87       break;
  88     case scm_tc7_asubr:
  89     case scm_tc7_rpsubr:
  90     case scm_tc7_lsubr:
  91       r = 1;
  92       break;
  93     case scm_tc7_lsubr_2:
  94       a += 2;
  95       r = 1;
  96       break;
  97     case scm_tc7_smob:
  98       if (SCM_SMOB_APPLICABLE_P (proc))
  99         {
 100           int type = SCM_SMOB_DESCRIPTOR (proc).gsubr_type;
 101           a += SCM_GSUBR_REQ (type);
 102           o = SCM_GSUBR_OPT (type);
 103           r = SCM_GSUBR_REST (type);
 104           break;
 105         }
 106       else
 107         {
 108           return SCM_BOOL_F;
 109         }
 110     case scm_tc7_cclo:
 111       if (SCM_EQ_P (SCM_CCLO_SUBR (proc), scm_f_gsubr_apply))
 112         {
 113           int type = SCM_INUM (SCM_GSUBR_TYPE (proc));
 114           a += SCM_GSUBR_REQ (type);
 115           o = SCM_GSUBR_OPT (type);
 116           r = SCM_GSUBR_REST (type);
 117           break;
 118         }
 119       else
 120         {
 121           proc = SCM_CCLO_SUBR (proc);
 122           a -= 1;
 123           goto loop;
 124         }
 125     case scm_tc7_pws:
 126       proc = SCM_PROCEDURE (proc);
 127       goto loop;
 128     case scm_tcs_closures:
 129       proc = SCM_CLOSURE_FORMALS (proc);
 130       if (SCM_NULLP (proc))
 131         break;
 132       while (SCM_CONSP (proc))
 133         {
 134           ++a;
 135           proc = SCM_CDR (proc);
 136         }
 137       if (!SCM_NULLP (proc))
 138         r = 1;
 139       break;
 140     case scm_tcs_struct:
 141       if (SCM_OBJ_CLASS_FLAGS (proc) & SCM_CLASSF_PURE_GENERIC)
 142         {
 143           r = 1;
 144           break;
 145         }
 146       else if (!SCM_I_OPERATORP (proc))
 147         return SCM_BOOL_F;
 148       proc = (SCM_I_ENTITYP (proc)
 149               ? SCM_ENTITY_PROCEDURE (proc)
 150               : SCM_OPERATOR_PROCEDURE (proc));
 151       a -= 1;
 152       goto loop;
 153     default:
 154       return SCM_BOOL_F;
 155     }
 156   return scm_list_3 (SCM_MAKINUM (a), SCM_MAKINUM (o), SCM_BOOL(r));
 157 }
 158
 159 static SCM
 160 scm_stand_in_scm_proc(SCM proc)
 161 {
 162   SCM answer;
 163   answer = scm_assq (proc, scm_stand_in_procs);
 164   if (SCM_FALSEP (answer))
 165     {
 166       answer = scm_closure (scm_list_2 (SCM_EOL, SCM_BOOL_F), SCM_EOL);
 167       scm_stand_in_procs = scm_acons (proc, answer, scm_stand_in_procs);
 168     }
 169   else
 170     answer = SCM_CDR (answer);
 171   return answer;
 172 }
 173
 174 SCM_DEFINE (scm_procedure_properties, "procedure-properties", 1, 0, 0,
 175            (SCM proc),
 176             "Return @var{obj}'s property list.")
 177 #define FUNC_NAME s_scm_procedure_properties
 178 {
 179   SCM_VALIDATE_PROC (1, proc);
 180   return scm_acons (scm_sym_arity, scm_i_procedure_arity (proc),
 181                     SCM_PROCPROPS (SCM_CLOSUREP (proc)
 182                                    ? proc
 183                                    : scm_stand_in_scm_proc (proc)));
 184 }
 185 #undef FUNC_NAME
 186
 187 SCM_DEFINE (scm_set_procedure_properties_x, "set-procedure-properties!", 2, 0, 0,
 188            (SCM proc, SCM new_val),
 189             "Set @var{obj}'s property list to @var{alist}.")
 190 #define FUNC_NAME s_scm_set_procedure_properties_x
 191 {
 192   if (!SCM_CLOSUREP (proc))
 193     proc = scm_stand_in_scm_proc(proc);
 194   SCM_VALIDATE_CLOSURE (1, proc);
 195   SCM_SETPROCPROPS (proc, new_val);
 196   return SCM_UNSPECIFIED;
 197 }
 198 #undef FUNC_NAME
 199
 200 SCM_DEFINE (scm_procedure_property, "procedure-property", 2, 0, 0,
 201            (SCM p, SCM k),
 202             "Return the property of @var{obj} with name @var{key}.")
 203 #define FUNC_NAME s_scm_procedure_property
 204 {
 205   SCM assoc;
 206   if (SCM_EQ_P (k, scm_sym_arity))
 207     {
 208       SCM arity;
 209       SCM_ASSERT (SCM_NFALSEP (arity = scm_i_procedure_arity (p)),
 210                   p, SCM_ARG1, FUNC_NAME);
 211       return arity;
 212     }
 213   SCM_VALIDATE_PROC (1, p);
 214   assoc = scm_sloppy_assq (k,
 215                            SCM_PROCPROPS (SCM_CLOSUREP (p)
 216                                           ? p
 217                                           : scm_stand_in_scm_proc (p)));
 218   return (SCM_NIMP (assoc) ? SCM_CDR (assoc) : SCM_BOOL_F);
 219 }
 220 #undef FUNC_NAME
 221
 222 SCM_DEFINE (scm_set_procedure_property_x, "set-procedure-property!", 3, 0, 0,
 223            (SCM p, SCM k, SCM v),
 224             "In @var{obj}'s property list, set the property named @var{key} to\n"
 225             "@var{value}.")
 226 #define FUNC_NAME s_scm_set_procedure_property_x
 227 {
 228   SCM assoc;
 229   if (!SCM_CLOSUREP (p))
 230     p = scm_stand_in_scm_proc(p);
 231   SCM_VALIDATE_CLOSURE (1, p);
 232   if (SCM_EQ_P (k, scm_sym_arity))
 233     SCM_MISC_ERROR ("arity is a read-only property", SCM_EOL);
 234   assoc = scm_sloppy_assq (k, SCM_PROCPROPS (p));
 235   if (SCM_NIMP (assoc))
 236     SCM_SETCDR (assoc, v);
 237   else
 238     SCM_SETPROCPROPS (p, scm_acons (k, v, SCM_PROCPROPS (p)));
 239   return SCM_UNSPECIFIED;
 240 }
 241 #undef FUNC_NAME
 242
 243 \f
 244
 245
 246 void
 247 scm_init_procprop ()
 248 {
 249 #include "libguile/procprop.x"
 250 }
 251
 252
 253 /*
 254   Local Variables:
 255   c-file-style: "gnu"
 256   End:
 257 */