libguile/keywords.c

   1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001 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
  43 \f
  44
  45 #include <string.h>
  46
  47 #include "libguile/_scm.h"
  48 #include "libguile/ports.h"
  49 #include "libguile/root.h"
  50 #include "libguile/smob.h"
  51 #include "libguile/hashtab.h"
  52
  53 #include "libguile/validate.h"
  54 #include "libguile/keywords.h"
  55 \f
  56
  57 scm_t_bits scm_tc16_keyword;
  58
  59 static int
  60 keyword_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
  61 {
  62   SCM symbol = SCM_KEYWORDSYM (exp);
  63
  64   scm_puts ("#:", port);
  65   scm_print_symbol_name (SCM_SYMBOL_CHARS (symbol) + 1,
  66                          SCM_SYMBOL_LENGTH (symbol) - 1,
  67                          port);
  68   scm_remember_upto_here_1 (symbol);
  69   return 1;
  70 }
  71
  72 SCM_DEFINE (scm_make_keyword_from_dash_symbol, "make-keyword-from-dash-symbol", 1, 0, 0,
  73             (SCM symbol),
  74             "Make a keyword object from a @var{symbol} that starts with a dash.")
  75 #define FUNC_NAME s_scm_make_keyword_from_dash_symbol
  76 {
  77   SCM keyword;
  78
  79   SCM_ASSERT (SCM_SYMBOLP (symbol)
  80               && ('-' == SCM_SYMBOL_CHARS(symbol)[0]),
  81               symbol, SCM_ARG1, FUNC_NAME);
  82
  83   SCM_DEFER_INTS;
  84   keyword = scm_hashq_ref (scm_keyword_obarray, symbol, SCM_BOOL_F);
  85   if (SCM_FALSEP (keyword))
  86     {
  87       SCM_NEWSMOB (keyword, scm_tc16_keyword, SCM_UNPACK (symbol));
  88       scm_hashq_set_x (scm_keyword_obarray, symbol, keyword);
  89     }
  90   SCM_ALLOW_INTS;
  91   return keyword;
  92 }
  93 #undef FUNC_NAME
  94
  95 SCM
  96 scm_c_make_keyword (char *s)
  97 {
  98   char *buf = scm_malloc (strlen (s) + 2);
  99   SCM symbol;
 100
 101   buf[0] = '-';
 102   strcpy (buf + 1, s);
 103   symbol = scm_str2symbol (buf);
 104   free (buf);
 105
 106   return scm_make_keyword_from_dash_symbol (symbol);
 107 }
 108
 109 SCM_DEFINE (scm_keyword_p, "keyword?", 1, 0, 0,
 110             (SCM obj),
 111             "Return @code{#t} if the argument @var{obj} is a keyword, else\n"
 112             "@code{#f}.")
 113 #define FUNC_NAME s_scm_keyword_p
 114 {
 115   return SCM_BOOL (SCM_KEYWORDP (obj));
 116 }
 117 #undef FUNC_NAME
 118
 119
 120 SCM_DEFINE (scm_keyword_dash_symbol, "keyword-dash-symbol", 1, 0, 0,
 121             (SCM keyword),
 122             "Return the dash symbol for @var{keyword}.\n"
 123             "This is the inverse of @code{make-keyword-from-dash-symbol}.")
 124 #define FUNC_NAME s_scm_keyword_dash_symbol
 125 {
 126   SCM_VALIDATE_KEYWORD (1, keyword);
 127   return SCM_KEYWORDSYM (keyword);
 128 }
 129 #undef FUNC_NAME
 130
 131
 132
 133 void
 134 scm_init_keywords ()
 135 {
 136   scm_tc16_keyword = scm_make_smob_type ("keyword", 0);
 137   scm_set_smob_mark (scm_tc16_keyword, scm_markcdr);
 138   scm_set_smob_print (scm_tc16_keyword, keyword_print);
 139
 140   scm_keyword_obarray = scm_c_make_hash_table (256);
 141 #ifndef SCM_MAGIC_SNARFER
 142 #include "libguile/keywords.x"
 143 #endif
 144 }
 145
 146
 147 /*
 148   Local Variables:
 149   c-file-style: "gnu"
 150   End:
 151 */