libguile/values.c

   1 /* Copyright (C) 2000, 2001, 2006, 2008 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
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library 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 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 02110-1301 USA
  16  */
  17
  18 #ifdef HAVE_CONFIG_H
  19 # include <config.h>
  20 #endif
  21
  22 #include "libguile/_scm.h"
  23 #include "libguile/eval.h"
  24 #include "libguile/feature.h"
  25 #include "libguile/gc.h"
  26 #include "libguile/numbers.h"
  27 #include "libguile/ports.h"
  28 #include "libguile/root.h"
  29 #include "libguile/strings.h"
  30 #include "libguile/struct.h"
  31 #include "libguile/validate.h"
  32
  33 #include "libguile/values.h"
  34
  35 SCM scm_values_vtable;
  36
  37 static SCM
  38 print_values (SCM obj, SCM pwps)
  39 {
  40   SCM values = scm_struct_ref (obj, SCM_INUM0);
  41   SCM port = SCM_PORT_WITH_PS_PORT (pwps);
  42   scm_print_state *ps = SCM_PRINT_STATE (SCM_PORT_WITH_PS_PS (pwps));
  43
  44   scm_puts ("#<values ", port);
  45   scm_iprin1 (values, port, ps);
  46   scm_puts (">", port);
  47
  48   return SCM_UNSPECIFIED;
  49 }
  50
  51 SCM_DEFINE (scm_values, "values", 0, 0, 1,
  52             (SCM args),
  53             "Delivers all of its arguments to its continuation.  Except for\n"
  54             "continuations created by the @code{call-with-values} procedure,\n"
  55             "all continuations take exactly one value.  The effect of\n"
  56             "passing no value or more than one value to continuations that\n"
  57             "were not created by @code{call-with-values} is unspecified.")
  58 #define FUNC_NAME s_scm_values
  59 {
  60   long n;
  61   SCM result;
  62
  63   SCM_VALIDATE_LIST_COPYLEN (1, args, n);
  64   if (n == 1)
  65     result = SCM_CAR (args);
  66   else
  67     {
  68       result = scm_make_struct (scm_values_vtable, SCM_INUM0,
  69                                 scm_list_1 (args));
  70     }
  71
  72   return result;
  73 }
  74 #undef FUNC_NAME
  75
  76 void
  77 scm_init_values (void)
  78 {
  79   SCM print = scm_c_define_subr ("%print-values", scm_tc7_subr_2,
  80                                  print_values);
  81
  82   scm_values_vtable
  83     = scm_permanent_object (
  84         scm_make_vtable_vtable (scm_from_locale_string ("pr"),
  85                                 SCM_INUM0, SCM_EOL));
  86
  87   SCM_SET_STRUCT_PRINTER (scm_values_vtable, print);
  88
  89   scm_add_feature ("values");
  90
  91 #include "libguile/values.x"
  92 }
  93
  94 /*
  95   Local Variables:
  96   c-file-style: "gnu"
  97   End:
  98 */