libguile/boolean.c

   1 /*      Copyright (C) 1995, 1996, 2000, 2001 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  16  */
  17
  18
  19 \f
  20
  21 #include "libguile/_scm.h"
  22
  23 #include "libguile/validate.h"
  24 #include "libguile/boolean.h"
  25 #include "libguile/lang.h"
  26 #include "libguile/tags.h"
  27
  28 \f
  29
  30
  31 SCM_DEFINE (scm_not, "not", 1, 0, 0,
  32             (SCM x),
  33             "Return @code{#t} iff @var{x} is @code{#f}, else return @code{#f}.")
  34 #define FUNC_NAME s_scm_not
  35 {
  36   return scm_from_bool (scm_is_false (x) || SCM_NILP (x));
  37 }
  38 #undef FUNC_NAME
  39
  40
  41 SCM_DEFINE (scm_boolean_p, "boolean?", 1, 0, 0,
  42            (SCM obj),
  43             "Return @code{#t} iff @var{obj} is either @code{#t} or @code{#f}.")
  44 #define FUNC_NAME s_scm_boolean_p
  45 {
  46   return scm_from_bool (scm_is_bool (obj) || SCM_NILP (obj));
  47 }
  48 #undef FUNC_NAME
  49
  50 int
  51 scm_is_bool (SCM x)
  52 {
  53   return scm_is_eq (x, SCM_BOOL_F) || scm_is_eq (x, SCM_BOOL_T);
  54 }
  55
  56 int
  57 scm_to_bool (SCM x)
  58 {
  59   if (scm_is_eq (x, SCM_BOOL_F))
  60     return 0;
  61   else if (scm_is_eq (x, SCM_BOOL_T))
  62     return 1;
  63   else
  64     scm_wrong_type_arg (NULL, 0, x);
  65 }
  66
  67 void
  68 scm_init_boolean ()
  69 {
  70 #include "libguile/boolean.x"
  71 }
  72
  73
  74 /*
  75   Local Variables:
  76   c-file-style: "gnu"
  77   End:
  78 */