libguile/boolean.c

   1 /*      Copyright (C) 1995, 1996, 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 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/validate.h"
  28 #include "libguile/boolean.h"
  29 #include "libguile/lang.h"
  30 #include "libguile/tags.h"
  31
  32 \f
  33
  34
  35 SCM_DEFINE (scm_not, "not", 1, 0, 0,
  36             (SCM x),
  37             "Return @code{#t} iff @var{x} is @code{#f}, else return @code{#f}.")
  38 #define FUNC_NAME s_scm_not
  39 {
  40   return scm_from_bool (scm_is_false (x) || SCM_NILP (x));
  41 }
  42 #undef FUNC_NAME
  43
  44
  45 SCM_DEFINE (scm_boolean_p, "boolean?", 1, 0, 0,
  46            (SCM obj),
  47             "Return @code{#t} iff @var{obj} is either @code{#t} or @code{#f}.")
  48 #define FUNC_NAME s_scm_boolean_p
  49 {
  50   return scm_from_bool (scm_is_bool (obj) || SCM_NILP (obj));
  51 }
  52 #undef FUNC_NAME
  53
  54 int
  55 scm_is_bool (SCM x)
  56 {
  57   return scm_is_eq (x, SCM_BOOL_F) || scm_is_eq (x, SCM_BOOL_T);
  58 }
  59
  60 int
  61 scm_to_bool (SCM x)
  62 {
  63   if (scm_is_eq (x, SCM_BOOL_F))
  64     return 0;
  65   else if (scm_is_eq (x, SCM_BOOL_T))
  66     return 1;
  67   else
  68     scm_wrong_type_arg (NULL, 0, x);
  69 }
  70
  71 void
  72 scm_init_boolean ()
  73 {
  74 #include "libguile/boolean.x"
  75 }
  76
  77
  78 /*
  79   Local Variables:
  80   c-file-style: "gnu"
  81   End:
  82 */