libguile/keywords.c

   1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2003, 2004, 2006, 2008, 2009, 2011 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 <string.h>
  26 #include <stdarg.h>
  27
  28 #include "libguile/_scm.h"
  29 #include "libguile/async.h"
  30 #include "libguile/ports.h"
  31 #include "libguile/root.h"
  32 #include "libguile/smob.h"
  33 #include "libguile/hashtab.h"
  34
  35 #include "libguile/validate.h"
  36 #include "libguile/keywords.h"
  37 #include "libguile/strings.h"
  38
  39 \f
  40
  41 static SCM keyword_obarray;
  42
  43 scm_t_bits scm_tc16_keyword;
  44
  45 #define KEYWORDP(X)     (SCM_SMOB_PREDICATE (scm_tc16_keyword, (X)))
  46 #define KEYWORDSYM(X)   (SCM_SMOB_OBJECT (X))
  47
  48 static int
  49 keyword_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
  50 {
  51   scm_puts_unlocked ("#:", port);
  52   scm_display (KEYWORDSYM (exp), port);
  53   return 1;
  54 }
  55
  56 SCM_DEFINE (scm_keyword_p, "keyword?", 1, 0, 0,
  57             (SCM obj),
  58             "Return @code{#t} if the argument @var{obj} is a keyword, else\n"
  59             "@code{#f}.")
  60 #define FUNC_NAME s_scm_keyword_p
  61 {
  62   return scm_from_bool (KEYWORDP (obj));
  63 }
  64 #undef FUNC_NAME
  65
  66 SCM_DEFINE (scm_symbol_to_keyword, "symbol->keyword", 1, 0, 0,
  67             (SCM symbol),
  68             "Return the keyword with the same name as @var{symbol}.")
  69 #define FUNC_NAME s_scm_symbol_to_keyword
  70 {
  71   SCM keyword;
  72
  73   SCM_ASSERT_TYPE (scm_is_symbol (symbol), symbol, 0, NULL, "symbol");
  74
  75   SCM_CRITICAL_SECTION_START;
  76   /* njrev: NEWSMOB and hashq_set_x can raise errors */
  77   keyword = scm_hashq_ref (keyword_obarray, symbol, SCM_BOOL_F);
  78   if (scm_is_false (keyword))
  79     {
  80       SCM_NEWSMOB (keyword, scm_tc16_keyword, SCM_UNPACK (symbol));
  81       scm_hashq_set_x (keyword_obarray, symbol, keyword);
  82     }
  83   SCM_CRITICAL_SECTION_END;
  84   return keyword;
  85 }
  86 #undef FUNC_NAME
  87
  88 SCM_DEFINE (scm_keyword_to_symbol, "keyword->symbol", 1, 0, 0,
  89             (SCM keyword),
  90             "Return the symbol with the same name as @var{keyword}.")
  91 #define FUNC_NAME s_scm_keyword_to_symbol
  92 {
  93   scm_assert_smob_type (scm_tc16_keyword, keyword);
  94   return KEYWORDSYM (keyword);
  95 }
  96 #undef FUNC_NAME
  97
  98 int
  99 scm_is_keyword (SCM val)
 100 {
 101   return KEYWORDP (val);
 102 }
 103
 104 SCM
 105 scm_from_locale_keyword (const char *name)
 106 {
 107   return scm_symbol_to_keyword (scm_from_locale_symbol (name));
 108 }
 109
 110 SCM
 111 scm_from_locale_keywordn (const char *name, size_t len)
 112 {
 113   return scm_symbol_to_keyword (scm_from_locale_symboln (name, len));
 114 }
 115
 116 SCM
 117 scm_from_latin1_keyword (const char *name)
 118 {
 119   return scm_symbol_to_keyword (scm_from_latin1_symbol (name));
 120 }
 121
 122 SCM
 123 scm_from_utf8_keyword (const char *name)
 124 {
 125   return scm_symbol_to_keyword (scm_from_utf8_symbol (name));
 126 }
 127
 128 SCM_SYMBOL (scm_keyword_argument_error, "keyword-argument-error");
 129
 130 void
 131 scm_c_bind_keyword_arguments (const char *subr, SCM rest,
 132                               scm_t_keyword_arguments_flags flags, ...)
 133 {
 134   va_list va;
 135
 136   if (SCM_UNLIKELY (!(flags & SCM_ALLOW_NON_KEYWORD_ARGUMENTS)
 137                     && scm_ilength (rest) % 2 != 0))
 138     scm_error (scm_keyword_argument_error,
 139                subr, "Odd length of keyword argument list",
 140                SCM_EOL, SCM_BOOL_F);
 141
 142   while (scm_is_pair (rest))
 143     {
 144       SCM kw_or_arg = SCM_CAR (rest);
 145       SCM tail = SCM_CDR (rest);
 146
 147       if (scm_is_keyword (kw_or_arg) && scm_is_pair (tail))
 148         {
 149           SCM kw;
 150           SCM *arg_p;
 151
 152           va_start (va, flags);
 153           for (;;)
 154             {
 155               kw = va_arg (va, SCM);
 156               if (SCM_UNBNDP (kw))
 157                 {
 158                   /* KW_OR_ARG is not in the list of expected keywords.  */
 159                   if (!(flags & SCM_ALLOW_OTHER_KEYS))
 160                     scm_error (scm_keyword_argument_error,
 161                                subr, "Unrecognized keyword",
 162                                SCM_EOL, SCM_BOOL_F);
 163                   break;
 164                 }
 165               arg_p = va_arg (va, SCM *);
 166               if (scm_is_eq (kw_or_arg, kw))
 167                 {
 168                   /* We found the matching keyword.  Store the
 169                      associated value and break out of the loop.  */
 170                   *arg_p = SCM_CAR (tail);
 171                   break;
 172                 }
 173             }
 174           va_end (va);
 175
 176           /* Advance REST.  */
 177           rest = SCM_CDR (tail);
 178         }
 179       else
 180         {
 181           /* The next argument is not a keyword, or is a singleton
 182              keyword at the end of REST.  */
 183           if (!(flags & SCM_ALLOW_NON_KEYWORD_ARGUMENTS))
 184             scm_error (scm_keyword_argument_error,
 185                        subr, "Invalid keyword",
 186                        SCM_EOL, SCM_BOOL_F);
 187
 188            /* Advance REST.  */
 189            rest = tail;
 190         }
 191     }
 192 }
 193
 194 /* njrev: critical sections reviewed so far up to here */
 195 void
 196 scm_init_keywords ()
 197 {
 198   scm_tc16_keyword = scm_make_smob_type ("keyword", 0);
 199   scm_set_smob_print (scm_tc16_keyword, keyword_print);
 200
 201   keyword_obarray = scm_c_make_hash_table (0);
 202 #include "libguile/keywords.x"
 203 }
 204
 205
 206 /*
 207   Local Variables:
 208   c-file-style: "gnu"
 209   End:
 210 */