libguile/feature.c

   1 /*      Copyright (C) 1995, 1996, 1998, 1999 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/eval.h"
  51 #include "libguile/ports.h"
  52 #include "libguile/procprop.h"
  53 #include "libguile/root.h"
  54 #include "libguile/smob.h"
  55 #include "libguile/strings.h"
  56
  57 #include "libguile/validate.h"
  58 #include "libguile/feature.h"
  59
  60 #ifdef HAVE_STRING_H
  61 #include <string.h>
  62 #endif
  63 \f
  64
  65 static SCM *scm_loc_features;
  66
  67 void
  68 scm_add_feature (const char *str)
  69 {
  70   *scm_loc_features = scm_cons (SCM_CAR (scm_intern (str, strlen (str))),
  71                                 *scm_loc_features);
  72 }
  73
  74
  75 \f
  76
  77 SCM_DEFINE (scm_program_arguments, "program-arguments", 0, 0, 0,
  78            (),
  79 "")
  80 #define FUNC_NAME s_scm_program_arguments
  81 {
  82   return scm_progargs;
  83 }
  84 #undef FUNC_NAME
  85
  86 /* Set the value returned by program-arguments, given ARGC and ARGV.
  87
  88    If FIRST is non-zero, make it the first element; we do this in
  89    situations where other code (like getopt) has parsed out a few
  90    arguments, but we still want the script name to be the first
  91    element.  */
  92 void
  93 scm_set_program_arguments (int argc, char **argv, char *first)
  94 {
  95   scm_progargs = scm_makfromstrs (argc, argv);
  96   if (first)
  97     scm_progargs = scm_cons (scm_makfrom0str (first), scm_progargs);
  98 }
  99
 100
 101 \f
 102 /* Hooks
 103  *
 104  * A hook is basically a list of procedures to be called at well defined
 105  * points in time.
 106  *
 107  * Hook name and arity are not full members of this type and therefore
 108  * lack accessors.  They are added to aid debugging and are not
 109  * intended to be used in programs.
 110  *
 111  */
 112
 113 long scm_tc16_hook;
 114
 115
 116 static SCM
 117 make_hook (SCM name, SCM n_args, const char *subr)
 118 {
 119   int n;
 120   SCM_ASSERT (SCM_FALSEP (name) || (SCM_SYMBOLP (name)),
 121               name,
 122               SCM_ARG1,
 123               subr);
 124   if (SCM_UNBNDP (n_args))
 125     n = 0;
 126   else
 127     {
 128       SCM_ASSERT (SCM_INUMP (n_args), n_args, SCM_ARGn, subr);
 129       n = SCM_INUM (n_args);
 130     }
 131   SCM_ASSERT (n >= 0 && n <= 16, n_args, SCM_OUTOFRANGE, subr);
 132   SCM_RETURN_NEWSMOB (scm_tc16_hook + (n << 16), SCM_UNPACK (SCM_LIST1 (name)));
 133 }
 134
 135
 136 static int
 137 print_hook (SCM hook, SCM port, scm_print_state *pstate)
 138 {
 139   SCM ls, name;
 140   scm_puts ("#<hook ", port);
 141   if (SCM_NFALSEP (SCM_HOOK_NAME (hook)))
 142     {
 143       scm_iprin1 (SCM_HOOK_NAME (hook), port, pstate);
 144       scm_putc (' ', port);
 145     }
 146   scm_intprint (SCM_HOOK_ARITY (hook), 10, port);
 147   scm_putc (' ', port);
 148   scm_intprint (SCM_UNPACK (hook), 16, port);
 149   ls = SCM_HOOK_PROCEDURES (hook);
 150   while (SCM_NIMP (ls))
 151     {
 152       scm_putc (' ', port);
 153       name = scm_procedure_name (SCM_CAR (ls));
 154       if (SCM_NFALSEP (name))
 155         scm_iprin1 (name, port, pstate);
 156       else
 157         scm_putc ('?', port);
 158       ls = SCM_CDR (ls);
 159     }
 160   scm_putc ('>', port);
 161   return 1;
 162 }
 163
 164
 165 SCM
 166 scm_create_hook (const char* name, int n_args)
 167 {
 168   SCM vcell = scm_sysintern0 (name);
 169   SCM hook = make_hook (SCM_CAR (vcell), SCM_MAKINUM (n_args),
 170                         "scm_create_hook");
 171   SCM_SETCDR (vcell, hook);
 172   scm_protect_object (vcell);
 173   return hook;
 174 }
 175
 176
 177 /* This function is deprecated.  It will be removed in next release. */
 178 SCM
 179 scm_make_named_hook (const char* name, int n_args)
 180 {
 181   return scm_create_hook (name, n_args);
 182 }
 183
 184
 185 SCM_DEFINE (scm_make_hook_with_name, "make-hook-with-name", 1, 1, 0,
 186             (SCM name, SCM n_args),
 187 "")
 188 #define FUNC_NAME s_scm_make_hook_with_name
 189 {
 190   return make_hook (name, n_args, FUNC_NAME);
 191 }
 192 #undef FUNC_NAME
 193
 194
 195 SCM_DEFINE (scm_make_hook, "make-hook", 0, 1, 0,
 196             (SCM n_args),
 197 "")
 198 #define FUNC_NAME s_scm_make_hook
 199 {
 200   return make_hook (SCM_BOOL_F, n_args, FUNC_NAME);
 201 }
 202 #undef FUNC_NAME
 203
 204
 205 SCM_DEFINE (scm_hook_p, "hook?", 1, 0, 0,
 206             (SCM x),
 207 "")
 208 #define FUNC_NAME s_scm_hook_p
 209 {
 210   return SCM_BOOL(SCM_HOOKP (x));
 211 }
 212 #undef FUNC_NAME
 213
 214
 215 SCM_DEFINE (scm_hook_empty_p, "hook-empty?", 1, 0, 0,
 216             (SCM hook),
 217 "")
 218 #define FUNC_NAME s_scm_hook_empty_p
 219 {
 220   SCM_VALIDATE_HOOK (1,hook);
 221   return SCM_BOOL(SCM_NULLP (SCM_HOOK_PROCEDURES (hook)));
 222 }
 223 #undef FUNC_NAME
 224
 225
 226 SCM_DEFINE (scm_add_hook_x, "add-hook!", 2, 1, 0,
 227             (SCM hook, SCM proc, SCM append_p),
 228 "")
 229 #define FUNC_NAME s_scm_add_hook_x
 230 {
 231   SCM arity, rest;
 232   int n_args;
 233   SCM_VALIDATE_HOOK (1,hook);
 234   SCM_ASSERT (SCM_NFALSEP (arity = scm_i_procedure_arity (proc)),
 235               proc, SCM_ARG2, FUNC_NAME);
 236   n_args = SCM_HOOK_ARITY (hook);
 237   if (SCM_INUM (SCM_CAR (arity)) > n_args
 238       || (SCM_FALSEP (SCM_CADDR (arity))
 239           && (SCM_INUM (SCM_CAR (arity)) + SCM_INUM (SCM_CADR (arity))
 240               < n_args)))
 241     scm_wrong_type_arg (FUNC_NAME, 2, proc);
 242   rest = scm_delq_x (proc, SCM_HOOK_PROCEDURES (hook));
 243   SCM_SET_HOOK_PROCEDURES (hook,
 244                            (!SCM_UNBNDP (append_p) && SCM_NFALSEP (append_p)
 245                             ? scm_append_x (SCM_LIST2 (rest, SCM_LIST1 (proc)))
 246                             : scm_cons (proc, rest)));
 247   return SCM_UNSPECIFIED;
 248 }
 249 #undef FUNC_NAME
 250
 251
 252 SCM_DEFINE (scm_remove_hook_x, "remove-hook!", 2, 0, 0,
 253             (SCM hook, SCM proc),
 254 "")
 255 #define FUNC_NAME s_scm_remove_hook_x
 256 {
 257   SCM_VALIDATE_HOOK (1,hook);
 258   SCM_SET_HOOK_PROCEDURES (hook,
 259                            scm_delq_x (proc, SCM_HOOK_PROCEDURES (hook)));
 260   return SCM_UNSPECIFIED;
 261 }
 262 #undef FUNC_NAME
 263
 264
 265 SCM_DEFINE (scm_reset_hook_x, "reset-hook!", 1, 0, 0,
 266             (SCM hook),
 267 "")
 268 #define FUNC_NAME s_scm_reset_hook_x
 269 {
 270   SCM_VALIDATE_HOOK (1,hook);
 271   SCM_SET_HOOK_PROCEDURES (hook, SCM_EOL);
 272   return SCM_UNSPECIFIED;
 273 }
 274 #undef FUNC_NAME
 275
 276
 277 SCM_DEFINE (scm_run_hook, "run-hook", 1, 0, 1,
 278             (SCM hook, SCM args),
 279 "")
 280 #define FUNC_NAME s_scm_run_hook
 281 {
 282   SCM_VALIDATE_HOOK (1,hook);
 283   if (SCM_UNBNDP (args))
 284     args = SCM_EOL;
 285   if (scm_ilength (args) != SCM_HOOK_ARITY (hook))
 286     SCM_MISC_ERROR ("Hook ~S requires ~A arguments",
 287                     SCM_LIST2 (hook,SCM_MAKINUM (SCM_HOOK_ARITY (hook))));
 288   scm_c_run_hook (hook, args);
 289   return SCM_UNSPECIFIED;
 290 }
 291 #undef FUNC_NAME
 292
 293
 294 void
 295 scm_c_run_hook (SCM hook, SCM args)
 296 {
 297   SCM procs = SCM_HOOK_PROCEDURES (hook);
 298   while (SCM_NIMP (procs))
 299     {
 300       scm_apply (SCM_CAR (procs), args, SCM_EOL);
 301       procs = SCM_CDR (procs);
 302     }
 303 }
 304
 305
 306 SCM_DEFINE (scm_hook_to_list, "hook->list", 1, 0, 0,
 307             (SCM hook),
 308 "")
 309 #define FUNC_NAME s_scm_hook_to_list
 310 {
 311   SCM_VALIDATE_HOOK (1,hook);
 312   return scm_list_copy (SCM_HOOK_PROCEDURES (hook));
 313 }
 314 #undef FUNC_NAME
 315
 316
 317 \f
 318
 319 void
 320 scm_init_feature()
 321 {
 322   scm_loc_features = SCM_CDRLOC (scm_sysintern ("*features*", SCM_EOL));
 323 #ifdef SCM_RECKLESS
 324   scm_add_feature("reckless");
 325 #endif
 326 #ifndef _Windows
 327   scm_add_feature("system");
 328 #endif
 329 #ifdef vms
 330   scm_add_feature(s_ed);
 331 #endif
 332 #ifdef SICP
 333   scm_add_feature("sicp");
 334 #endif
 335 #ifndef GO32
 336   scm_add_feature("char-ready?");
 337 #endif
 338 #ifndef CHEAP_CONTINUATIONS
 339   scm_add_feature ("full-continuation");
 340 #endif
 341 #ifdef USE_THREADS
 342   scm_add_feature ("threads");
 343 #endif
 344
 345   scm_sysintern ("char-code-limit", SCM_MAKINUM (SCM_CHAR_CODE_LIMIT));
 346
 347   scm_tc16_hook = scm_make_smob_type ("hook", 0);
 348   scm_set_smob_mark (scm_tc16_hook, scm_markcdr);
 349   scm_set_smob_print (scm_tc16_hook, print_hook);
 350
 351 #include "libguile/feature.x"
 352 }
 353
 354 /*
 355   Local Variables:
 356   c-file-style: "gnu"
 357   End:
 358 */