intl/plural-exp.h

   1 /* Expression parsing and evaluation for plural form selection.
   2    Copyright (C) 2000, 2001, 2002, 2005, 2007 Free Software Foundation, Inc.
   3    Written by Ulrich Drepper <drepper@cygnus.com>, 2000.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _PLURAL_EXP_H
  21 #define _PLURAL_EXP_H
  22
  23 #ifndef PARAMS
  24 # if __STDC__ || defined __GNUC__ || defined __SUNPRO_C || defined __cplusplus || __PROTOTYPES
  25 #  define PARAMS(args) args
  26 # else
  27 #  define PARAMS(args) ()
  28 # endif
  29 #endif
  30
  31 #ifndef internal_function
  32 # define internal_function
  33 #endif
  34
  35 #ifndef attribute_hidden
  36 # define attribute_hidden
  37 #endif
  38
  39
  40 /* This is the representation of the expressions to determine the
  41    plural form.  */
  42 struct expression
  43 {
  44   int nargs;                    /* Number of arguments.  */
  45   enum operator
  46   {
  47     /* Without arguments:  */
  48     var,                        /* The variable "n".  */
  49     num,                        /* Decimal number.  */
  50     /* Unary operators:  */
  51     lnot,                       /* Logical NOT.  */
  52     /* Binary operators:  */
  53     mult,                       /* Multiplication.  */
  54     divide,                     /* Division.  */
  55     module,                     /* Modulo operation.  */
  56     plus,                       /* Addition.  */
  57     minus,                      /* Subtraction.  */
  58     less_than,                  /* Comparison.  */
  59     greater_than,               /* Comparison.  */
  60     less_or_equal,              /* Comparison.  */
  61     greater_or_equal,           /* Comparison.  */
  62     equal,                      /* Comparison for equality.  */
  63     not_equal,                  /* Comparison for inequality.  */
  64     land,                       /* Logical AND.  */
  65     lor,                        /* Logical OR.  */
  66     /* Ternary operators:  */
  67     qmop                        /* Question mark operator.  */
  68   } operation;
  69   union
  70   {
  71     unsigned long int num;      /* Number value for `num'.  */
  72     struct expression *args[3]; /* Up to three arguments.  */
  73   } val;
  74 };
  75
  76 /* This is the data structure to pass information to the parser and get
  77    the result in a thread-safe way.  */
  78 struct parse_args
  79 {
  80   const char *cp;
  81   struct expression *res;
  82 };
  83
  84
  85 /* Names for the libintl functions are a problem.  This source code is used
  86    1. in the GNU C Library library,
  87    2. in the GNU libintl library,
  88    3. in the GNU gettext tools.
  89    The function names in each situation must be different, to allow for
  90    binary incompatible changes in 'struct expression'.  Furthermore,
  91    1. in the GNU C Library library, the names have a __ prefix,
  92    2.+3. in the GNU libintl library and in the GNU gettext tools, the names
  93          must follow ANSI C and not start with __.
  94    So we have to distinguish the three cases.  */
  95 #ifdef _LIBC
  96 # define FREE_EXPRESSION __gettext_free_exp
  97 # define PLURAL_PARSE __gettextparse
  98 # define GERMANIC_PLURAL __gettext_germanic_plural
  99 # define EXTRACT_PLURAL_EXPRESSION __gettext_extract_plural
 100 #elif defined (IN_LIBINTL)
 101 # define FREE_EXPRESSION libintl_gettext_free_exp
 102 # define PLURAL_PARSE libintl_gettextparse
 103 # define GERMANIC_PLURAL libintl_gettext_germanic_plural
 104 # define EXTRACT_PLURAL_EXPRESSION libintl_gettext_extract_plural
 105 #else
 106 # define FREE_EXPRESSION free_plural_expression
 107 # define PLURAL_PARSE parse_plural_expression
 108 # define GERMANIC_PLURAL germanic_plural
 109 # define EXTRACT_PLURAL_EXPRESSION extract_plural_expression
 110 #endif
 111
 112 extern void FREE_EXPRESSION PARAMS ((struct expression *exp))
 113      internal_function;
 114 extern int PLURAL_PARSE PARAMS ((void *arg));
 115 extern const struct expression GERMANIC_PLURAL attribute_hidden;
 116 extern void EXTRACT_PLURAL_EXPRESSION PARAMS
 117   ((const char *nullentry, const struct expression **pluralp,
 118     unsigned long int *npluralsp)) internal_function;
 119
 120 #if !defined (_LIBC) && !defined (IN_LIBINTL)
 121 extern unsigned long int plural_eval PARAMS ((const struct expression *pexp,
 122                                               unsigned long int n));
 123 #endif
 124
 125 #endif /* _PLURAL_EXP_H */