libguile/keywords.c

   1 /* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004,
   2  *   2006, 2008, 2009, 2011, 2013, 2015 Free Software Foundation, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public License
   6  * as published by the Free Software Foundation; either version 3 of
   7  * the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301 USA
  18  */
  19
  20
  21 \f
  22 #ifdef HAVE_CONFIG_H
  23 # include <config.h>
  24 #endif
  25
  26 #include <string.h>
  27 #include <stdarg.h>
  28
  29 #include "libguile/_scm.h"
  30 #include "libguile/async.h"
  31 #include "libguile/ports.h"
  32 #include "libguile/root.h"
  33 #include "libguile/smob.h"
  34 #include "libguile/hashtab.h"
  35
  36 #include "libguile/validate.h"
  37 #include "libguile/keywords.h"
  38 #include "libguile/strings.h"
  39
  40 \f
  41
  42 static SCM keyword_obarray;
  43
  44 #define SCM_KEYWORDP(x) (SCM_HAS_TYP7 (x, scm_tc7_keyword))
  45 #define SCM_KEYWORD_SYMBOL(x) (SCM_CELL_OBJECT_1 (x))
  46
  47 SCM_DEFINE (scm_keyword_p, "keyword?", 1, 0, 0,
  48             (SCM obj),
  49             "Return @code{#t} if the argument @var{obj} is a keyword, else\n"
  50             "@code{#f}.")
  51 #define FUNC_NAME s_scm_keyword_p
  52 {
  53   return scm_from_bool (SCM_KEYWORDP (obj));
  54 }
  55 #undef FUNC_NAME
  56
  57 SCM_DEFINE (scm_symbol_to_keyword, "symbol->keyword", 1, 0, 0,
  58             (SCM symbol),
  59             "Return the keyword with the same name as @var{symbol}.")
  60 #define FUNC_NAME s_scm_symbol_to_keyword
  61 {
  62   SCM keyword;
  63
  64   SCM_ASSERT_TYPE (scm_is_symbol (symbol), symbol, 0, NULL, "symbol");
  65
  66   SCM_CRITICAL_SECTION_START;
  67   /* Note: `scm_cell' and `scm_hashq_set_x' can raise an out-of-memory
  68      error.  */
  69   keyword = scm_hashq_ref (keyword_obarray, symbol, SCM_BOOL_F);
  70   if (scm_is_false (keyword))
  71     {
  72       keyword = scm_cell (scm_tc7_keyword, SCM_UNPACK (symbol));
  73       scm_hashq_set_x (keyword_obarray, symbol, keyword);
  74     }
  75   SCM_CRITICAL_SECTION_END;
  76   return keyword;
  77 }
  78 #undef FUNC_NAME
  79
  80 SCM_DEFINE (scm_keyword_to_symbol, "keyword->symbol", 1, 0, 0,
  81             (SCM keyword),
  82             "Return the symbol with the same name as @var{keyword}.")
  83 #define FUNC_NAME s_scm_keyword_to_symbol
  84 {
  85   SCM_VALIDATE_KEYWORD (1, keyword);
  86   return SCM_KEYWORD_SYMBOL (keyword);
  87 }
  88 #undef FUNC_NAME
  89
  90 int
  91 scm_is_keyword (SCM val)
  92 {
  93   return SCM_KEYWORDP (val);
  94 }
  95
  96 SCM
  97 scm_from_locale_keyword (const char *name)
  98 {
  99   return scm_symbol_to_keyword (scm_from_locale_symbol (name));
 100 }
 101
 102 SCM
 103 scm_from_locale_keywordn (const char *name, size_t len)
 104 {
 105   return scm_symbol_to_keyword (scm_from_locale_symboln (name, len));
 106 }
 107
 108 SCM
 109 scm_from_latin1_keyword (const char *name)
 110 {
 111   return scm_symbol_to_keyword (scm_from_latin1_symbol (name));
 112 }
 113
 114 SCM
 115 scm_from_utf8_keyword (const char *name)
 116 {
 117   return scm_symbol_to_keyword (scm_from_utf8_symbol (name));
 118 }
 119
 120 SCM_SYMBOL (scm_keyword_argument_error, "keyword-argument-error");
 121
 122 void
 123 scm_c_bind_keyword_arguments (const char *subr, SCM rest,
 124                               scm_t_keyword_arguments_flags flags, ...)
 125 {
 126   va_list va;
 127
 128   if (SCM_UNLIKELY (!(flags & SCM_ALLOW_NON_KEYWORD_ARGUMENTS)
 129                     && scm_ilength (rest) % 2 != 0))
 130     scm_error (scm_keyword_argument_error,
 131                subr, "Odd length of keyword argument list",
 132                SCM_EOL, SCM_BOOL_F);
 133
 134   while (scm_is_pair (rest))
 135     {
 136       SCM kw_or_arg = SCM_CAR (rest);
 137       SCM tail = SCM_CDR (rest);
 138
 139       if (scm_is_keyword (kw_or_arg) && scm_is_pair (tail))
 140         {
 141           SCM kw;
 142           SCM *arg_p;
 143
 144           va_start (va, flags);
 145           for (;;)
 146             {
 147               kw = va_arg (va, SCM);
 148               if (SCM_UNBNDP (kw))
 149                 {
 150                   /* KW_OR_ARG is not in the list of expected keywords.  */
 151                   if (!(flags & SCM_ALLOW_OTHER_KEYS))
 152                     scm_error_scm (scm_keyword_argument_error,
 153                                    scm_from_locale_string (subr),
 154                                    scm_from_latin1_string
 155                                    ("Unrecognized keyword"),
 156                                    SCM_EOL, scm_list_1 (kw_or_arg));
 157                   break;
 158                 }
 159               arg_p = va_arg (va, SCM *);
 160               if (scm_is_eq (kw_or_arg, kw))
 161                 {
 162                   /* We found the matching keyword.  Store the
 163                      associated value and break out of the loop.  */
 164                   *arg_p = SCM_CAR (tail);
 165                   break;
 166                 }
 167             }
 168           va_end (va);
 169
 170           /* Advance REST.  */
 171           rest = SCM_CDR (tail);
 172         }
 173       else
 174         {
 175           /* The next argument is not a keyword, or is a singleton
 176              keyword at the end of REST.  */
 177           if (!(flags & SCM_ALLOW_NON_KEYWORD_ARGUMENTS))
 178             scm_error_scm (scm_keyword_argument_error,
 179                            scm_from_locale_string (subr),
 180                            scm_from_latin1_string ("Invalid keyword"),
 181                            SCM_EOL, scm_list_1 (kw_or_arg));
 182
 183            /* Advance REST.  */
 184            rest = tail;
 185         }
 186     }
 187 }
 188
 189 void
 190 scm_init_keywords ()
 191 {
 192   keyword_obarray = scm_c_make_hash_table (0);
 193 #include "libguile/keywords.x"
 194 }
 195
 196
 197 /*
 198   Local Variables:
 199   c-file-style: "gnu"
 200   End:
 201 */