libguile/feature.c

   1 /*      Copyright (C) 1995,1996,1998 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 #include <stdio.h>
  44 #include "_scm.h"
  45
  46 #include "eval.h"
  47 #include "procprop.h"
  48
  49 #include "feature.h"
  50
  51 #ifdef HAVE_STRING_H
  52 #include <string.h>
  53 #endif
  54 \f
  55
  56 static SCM *scm_loc_features;
  57
  58 void
  59 scm_add_feature (str)
  60      const char* str;
  61 {
  62   *scm_loc_features = scm_cons (SCM_CAR (scm_intern (str, strlen (str))),
  63                                 *scm_loc_features);
  64 }
  65
  66
  67 \f
  68 SCM_PROC(s_program_arguments, "program-arguments", 0, 0, 0, scm_program_arguments);
  69
  70 SCM
  71 scm_program_arguments ()
  72 {
  73   return scm_progargs;
  74 }
  75
  76 /* Set the value returned by program-arguments, given ARGC and ARGV.
  77
  78    If FIRST is non-zero, make it the first element; we do this in
  79    situations where other code (like getopt) has parsed out a few
  80    arguments, but we still want the script name to be the first
  81    element.  */
  82 void
  83 scm_set_program_arguments (argc, argv, first)
  84      int argc;
  85      char **argv;
  86      char *first;
  87 {
  88   scm_progargs = scm_makfromstrs (argc, argv);
  89   if (first)
  90     scm_progargs = scm_cons (scm_makfrom0str (first), scm_progargs);
  91 }
  92
  93
  94 \f
  95 /* Hooks */
  96
  97 SCM_SYMBOL (scm_sym_hook, "hook");
  98
  99 SCM_PROC (s_make_hook, "make-hook", 0, 1, 0, scm_make_hook);
 100
 101 SCM
 102 scm_make_hook (SCM n_args)
 103 {
 104   if (SCM_UNBNDP (n_args))
 105     n_args = SCM_INUM0;
 106   else
 107     SCM_ASSERT (SCM_INUMP (n_args), n_args, SCM_ARG1, s_make_hook);
 108   return scm_cons2 (scm_sym_hook, n_args, SCM_EOL);
 109 }
 110
 111 SCM
 112 scm_make_named_hook (char* name, int n_args)
 113 {
 114   SCM hook = scm_make_hook (SCM_MAKINUM (n_args));
 115   scm_permanent_object (scm_sysintern (name, hook));
 116   return hook;
 117 }
 118
 119 SCM_PROC (s_add_hook_x, "add-hook!", 2, 1, 0, scm_add_hook_x);
 120
 121 SCM
 122 scm_add_hook_x (SCM hook, SCM proc, SCM append_p)
 123 {
 124   SCM arity, rest;
 125   int n_args;
 126   SCM_ASSERT (SCM_NIMP (hook) && SCM_CONSP (hook)
 127               && SCM_CAR (hook) == scm_sym_hook
 128               && SCM_NIMP (SCM_CDR (hook)) && SCM_CONSP (SCM_CDR (hook))
 129               && SCM_INUMP (SCM_CADR (hook))
 130               && scm_ilength (SCM_CDDR (hook)) >= 0,
 131               hook, SCM_ARG1, s_add_hook_x);
 132   SCM_ASSERT (SCM_NFALSEP (arity = scm_i_procedure_arity (proc)),
 133               proc, SCM_ARG2, s_add_hook_x);
 134   n_args = SCM_INUM (SCM_CADR (hook));
 135   if (SCM_INUM (SCM_CAR (arity)) > n_args
 136       || (SCM_FALSEP (SCM_CADDR (arity))
 137           && (SCM_INUM (SCM_CAR (arity)) + SCM_INUM (SCM_CADR (arity))
 138               < n_args)))
 139     scm_misc_error (s_add_hook_x,
 140                     "This hook requires %s arguments",
 141                     SCM_LIST1 (SCM_CADR (hook)));
 142   rest = scm_delq_x (proc, SCM_CDDR (hook));
 143   SCM_SETCDR (SCM_CDR (hook),
 144               (!SCM_UNBNDP (append_p) && SCM_NFALSEP (append_p)
 145                ? scm_append_x (SCM_LIST2 (rest, SCM_LIST1 (proc)))
 146                : scm_cons (proc, rest)));
 147   return SCM_UNSPECIFIED;
 148 }
 149
 150 SCM_PROC (s_remove_hook_x, "remove-hook!", 2, 0, 0, scm_remove_hook_x);
 151
 152 SCM
 153 scm_remove_hook_x (SCM hook, SCM thunk)
 154 {
 155   SCM_ASSERT (SCM_NIMP (hook) && SCM_CONSP (hook)
 156               && SCM_CAR (hook) == scm_sym_hook
 157               && SCM_NIMP (SCM_CDR (hook)) && SCM_CONSP (SCM_CDR (hook))
 158               && SCM_INUMP (SCM_CADR (hook))
 159               && scm_ilength (SCM_CDDR (hook)) >= 0,
 160               hook, SCM_ARG1, s_remove_hook_x);
 161   SCM_SETCDR (SCM_CDR (hook), scm_delq_x (thunk, SCM_CDDR (hook)));
 162   return SCM_UNSPECIFIED;
 163 }
 164
 165 SCM_PROC (s_reset_hook_x, "reset-hook!", 1, 0, 0, scm_reset_hook_x);
 166
 167 SCM
 168 scm_reset_hook_x (SCM hook)
 169 {
 170   SCM_ASSERT (SCM_NIMP (hook) && SCM_CONSP (hook)
 171               && SCM_CAR (hook) == scm_sym_hook
 172               && SCM_NIMP (SCM_CDR (hook)) && SCM_CONSP (SCM_CDR (hook))
 173               && SCM_INUMP (SCM_CADR (hook))
 174               && scm_ilength (SCM_CDDR (hook)) >= 0,
 175               hook, SCM_ARG1, s_reset_hook_x);
 176   SCM_SETCDR (SCM_CDR (hook), SCM_EOL);
 177   return SCM_UNSPECIFIED;
 178 }
 179
 180 SCM_PROC (s_run_hook, "run-hook", 1, 0, 1, scm_run_hook);
 181
 182 SCM
 183 scm_run_hook (SCM hook, SCM args)
 184 {
 185   SCM_ASSERT (SCM_NIMP (hook) && SCM_CONSP (hook)
 186               && SCM_CAR (hook) == scm_sym_hook
 187               && SCM_NIMP (SCM_CDR (hook)) && SCM_CONSP (SCM_CDR (hook))
 188               && SCM_INUMP (SCM_CADR (hook))
 189               && scm_ilength (SCM_CDDR (hook)) >= 0,
 190               hook, SCM_ARG1, s_run_hook);
 191   if (SCM_UNBNDP (args))
 192     args = SCM_EOL;
 193   if (scm_ilength (args) != SCM_INUM (SCM_CADR (hook)))
 194     scm_misc_error (s_add_hook_x,
 195                     "This hook requires %s arguments",
 196                     SCM_LIST1 (SCM_CADR (hook)));
 197   hook = SCM_CDR (hook);
 198   while (SCM_NIMP (hook = SCM_CDR (hook)))
 199     scm_apply (SCM_CAR (hook), args, SCM_EOL);
 200   return SCM_UNSPECIFIED;
 201 }
 202
 203 \f
 204
 205 void
 206 scm_init_feature()
 207 {
 208   scm_loc_features = SCM_CDRLOC (scm_sysintern ("*features*", SCM_EOL));
 209 #ifdef SCM_RECKLESS
 210   scm_add_feature("reckless");
 211 #endif
 212 #ifndef _Windows
 213   scm_add_feature("system");
 214 #endif
 215 #ifdef vms
 216   scm_add_feature(s_ed);
 217 #endif
 218 #ifdef SICP
 219   scm_add_feature("sicp");
 220 #endif
 221 #ifndef GO32
 222   scm_add_feature("char-ready?");
 223 #endif
 224 #ifndef CHEAP_CONTINUATIONS
 225   scm_add_feature ("full-continuation");
 226 #endif
 227 #ifdef USE_THREADS
 228   scm_add_feature ("threads");
 229 #endif
 230
 231   scm_sysintern ("char-code-limit", SCM_MAKINUM (SCM_CHAR_CODE_LIMIT));
 232 #include "feature.x"
 233 }