libguile/procprop.c

   1 /* Copyright (C) 1995,1996,1998,2000,2001,2003,2004, 2006, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public License
   5  * as published by the Free Software Foundation; either version 3 of
   6  * the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  16  * 02110-1301 USA
  17  */
  18
  19
  20 \f
  21 #ifdef HAVE_CONFIG_H
  22 # include <config.h>
  23 #endif
  24
  25 #include "libguile/_scm.h"
  26
  27 #include "libguile/alist.h"
  28 #include "libguile/eval.h"
  29 #include "libguile/procs.h"
  30 #include "libguile/gsubr.h"
  31 #include "libguile/smob.h"
  32 #include "libguile/root.h"
  33 #include "libguile/vectors.h"
  34 #include "libguile/hashtab.h"
  35 #include "libguile/programs.h"
  36
  37 #include "libguile/validate.h"
  38 #include "libguile/procprop.h"
  39 \f
  40
  41 SCM_GLOBAL_SYMBOL (scm_sym_system_procedure, "system-procedure");
  42 SCM_GLOBAL_SYMBOL (scm_sym_name, "name");
  43
  44 static SCM overrides;
  45 static scm_i_pthread_mutex_t overrides_lock = SCM_I_PTHREAD_MUTEX_INITIALIZER;
  46
  47 int
  48 scm_i_procedure_arity (SCM proc, int *req, int *opt, int *rest)
  49 {
  50   while (!SCM_PROGRAM_P (proc))
  51     {
  52       if (SCM_IMP (proc))
  53         return 0;
  54       switch (SCM_TYP7 (proc))
  55         {
  56         case scm_tc7_smob:
  57           if (!SCM_SMOB_APPLICABLE_P (proc))
  58             return 0;
  59           proc = scm_i_smob_apply_trampoline (proc);
  60           break;
  61         case scm_tcs_struct:
  62           if (!SCM_STRUCT_APPLICABLE_P (proc))
  63             return 0;
  64           proc = SCM_STRUCT_PROCEDURE (proc);
  65           break;
  66         default:
  67           return 0;
  68         }
  69     }
  70   return scm_i_program_arity (proc, req, opt, rest);
  71 }
  72
  73 SCM_DEFINE (scm_procedure_minimum_arity, "procedure-minimum-arity", 1, 0, 0,
  74            (SCM proc),
  75             "Return the \"minimum arity\" of a procedure.\n\n"
  76             "If the procedure has only one arity, that arity is returned\n"
  77             "as a list of three values: the number of required arguments,\n"
  78             "the number of optional arguments, and a boolean indicating\n"
  79             "whether or not the procedure takes rest arguments.\n\n"
  80             "For a case-lambda procedure, the arity returned is the one\n"
  81             "with the lowest minimum number of arguments, and the highest\n"
  82             "maximum number of arguments.\n\n"
  83             "If it was not possible to determine the arity of the procedure,\n"
  84             "@code{#f} is returned.")
  85 #define FUNC_NAME s_scm_procedure_minimum_arity
  86 {
  87   int req, opt, rest;
  88
  89   if (scm_i_procedure_arity (proc, &req, &opt, &rest))
  90     return scm_list_3 (scm_from_int (req),
  91                        scm_from_int (opt),
  92                        scm_from_bool (rest));
  93   else
  94     return SCM_BOOL_F;
  95 }
  96 #undef FUNC_NAME
  97
  98 SCM_DEFINE (scm_procedure_properties, "procedure-properties", 1, 0, 0,
  99            (SCM proc),
 100             "Return @var{obj}'s property list.")
 101 #define FUNC_NAME s_scm_procedure_properties
 102 {
 103   SCM ret;
 104
 105   SCM_VALIDATE_PROC (1, proc);
 106
 107   scm_i_pthread_mutex_lock (&overrides_lock);
 108   ret = scm_hashq_ref (overrides, proc, SCM_BOOL_F);
 109   scm_i_pthread_mutex_unlock (&overrides_lock);
 110
 111   if (scm_is_false (ret))
 112     {
 113       if (SCM_PROGRAM_P (proc))
 114         ret = scm_i_program_properties (proc);
 115       else
 116         ret = SCM_EOL;
 117     }
 118
 119   return ret;
 120 }
 121 #undef FUNC_NAME
 122
 123 SCM_DEFINE (scm_set_procedure_properties_x, "set-procedure-properties!", 2, 0, 0,
 124            (SCM proc, SCM alist),
 125             "Set @var{proc}'s property list to @var{alist}.")
 126 #define FUNC_NAME s_scm_set_procedure_properties_x
 127 {
 128   SCM_VALIDATE_PROC (1, proc);
 129
 130   scm_i_pthread_mutex_lock (&overrides_lock);
 131   scm_hashq_set_x (overrides, proc, alist);
 132   scm_i_pthread_mutex_unlock (&overrides_lock);
 133
 134   return SCM_UNSPECIFIED;
 135 }
 136 #undef FUNC_NAME
 137
 138 SCM_DEFINE (scm_procedure_property, "procedure-property", 2, 0, 0,
 139            (SCM proc, SCM key),
 140             "Return the property of @var{proc} with name @var{key}.")
 141 #define FUNC_NAME s_scm_procedure_property
 142 {
 143   SCM_VALIDATE_PROC (1, proc);
 144
 145   return scm_assq_ref (scm_procedure_properties (proc), key);
 146 }
 147 #undef FUNC_NAME
 148
 149 SCM_DEFINE (scm_set_procedure_property_x, "set-procedure-property!", 3, 0, 0,
 150            (SCM proc, SCM key, SCM val),
 151             "In @var{proc}'s property list, set the property named @var{key} to\n"
 152             "@var{val}.")
 153 #define FUNC_NAME s_scm_set_procedure_property_x
 154 {
 155   SCM props;
 156
 157   SCM_VALIDATE_PROC (1, proc);
 158
 159   props = scm_procedure_properties (proc);
 160
 161   scm_i_pthread_mutex_lock (&overrides_lock);
 162   scm_hashq_set_x (overrides, proc, scm_assq_set_x (props, key, val));
 163   scm_i_pthread_mutex_unlock (&overrides_lock);
 164
 165   return SCM_UNSPECIFIED;
 166 }
 167 #undef FUNC_NAME
 168
 169 \f
 170
 171
 172 void
 173 scm_init_procprop ()
 174 {
 175   overrides = scm_make_weak_key_hash_table (SCM_UNDEFINED);
 176 #include "libguile/procprop.x"
 177 }
 178
 179
 180 /*
 181   Local Variables:
 182   c-file-style: "gnu"
 183   End:
 184 */