intl/plural-exp.h

   1 /* Expression parsing and evaluation for plural form selection.
   2    Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
   3    Written by Ulrich Drepper <drepper@cygnus.com>, 2000.
   4
   5    This program is free software; you can redistribute it and/or modify it
   6    under the terms of the GNU Library General Public License as published
   7    by the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with this program; if not, write to the Free Software
  17    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301,
  18    USA.  */
  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 struct expression GERMANIC_PLURAL attribute_hidden;
 116 extern void EXTRACT_PLURAL_EXPRESSION PARAMS ((const char *nullentry,
 117                                                struct expression **pluralp,
 118                                                unsigned long int *npluralsp))
 119      internal_function;
 120
 121 #if !defined (_LIBC) && !defined (IN_LIBINTL)
 122 extern unsigned long int plural_eval PARAMS ((struct expression *pexp,
 123                                               unsigned long int n));
 124 #endif
 125
 126 #endif /* _PLURAL_EXP_H */