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    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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #ifndef _PLURAL_EXP_H
  22 #define _PLURAL_EXP_H
  23
  24 #ifndef PARAMS
  25 # if __STDC__ || defined __GNUC__ || defined __SUNPRO_C || defined __cplusplus || __PROTOTYPES
  26 #  define PARAMS(args) args
  27 # else
  28 #  define PARAMS(args) ()
  29 # endif
  30 #endif
  31
  32 #ifndef internal_function
  33 # define internal_function
  34 #endif
  35
  36 #ifndef attribute_hidden
  37 # define attribute_hidden
  38 #endif
  39
  40
  41 /* This is the representation of the expressions to determine the
  42    plural form.  */
  43 struct expression
  44 {
  45   int nargs;                    /* Number of arguments.  */
  46   enum operator
  47   {
  48     /* Without arguments:  */
  49     var,                        /* The variable "n".  */
  50     num,                        /* Decimal number.  */
  51     /* Unary operators:  */
  52     lnot,                       /* Logical NOT.  */
  53     /* Binary operators:  */
  54     mult,                       /* Multiplication.  */
  55     divide,                     /* Division.  */
  56     module,                     /* Modulo operation.  */
  57     plus,                       /* Addition.  */
  58     minus,                      /* Subtraction.  */
  59     less_than,                  /* Comparison.  */
  60     greater_than,               /* Comparison.  */
  61     less_or_equal,              /* Comparison.  */
  62     greater_or_equal,           /* Comparison.  */
  63     equal,                      /* Comparison for equality.  */
  64     not_equal,                  /* Comparison for inequality.  */
  65     land,                       /* Logical AND.  */
  66     lor,                        /* Logical OR.  */
  67     /* Ternary operators:  */
  68     qmop                        /* Question mark operator.  */
  69   } operation;
  70   union
  71   {
  72     unsigned long int num;      /* Number value for `num'.  */
  73     struct expression *args[3]; /* Up to three arguments.  */
  74   } val;
  75 };
  76
  77 /* This is the data structure to pass information to the parser and get
  78    the result in a thread-safe way.  */
  79 struct parse_args
  80 {
  81   const char *cp;
  82   struct expression *res;
  83 };
  84
  85
  86 /* Names for the libintl functions are a problem.  This source code is used
  87    1. in the GNU C Library library,
  88    2. in the GNU libintl library,
  89    3. in the GNU gettext tools.
  90    The function names in each situation must be different, to allow for
  91    binary incompatible changes in 'struct expression'.  Furthermore,
  92    1. in the GNU C Library library, the names have a __ prefix,
  93    2.+3. in the GNU libintl library and in the GNU gettext tools, the names
  94          must follow ANSI C and not start with __.
  95    So we have to distinguish the three cases.  */
  96 #ifdef _LIBC
  97 # define FREE_EXPRESSION __gettext_free_exp
  98 # define PLURAL_PARSE __gettextparse
  99 # define GERMANIC_PLURAL __gettext_germanic_plural
 100 # define EXTRACT_PLURAL_EXPRESSION __gettext_extract_plural
 101 #elif defined (IN_LIBINTL)
 102 # define FREE_EXPRESSION libintl_gettext_free_exp
 103 # define PLURAL_PARSE libintl_gettextparse
 104 # define GERMANIC_PLURAL libintl_gettext_germanic_plural
 105 # define EXTRACT_PLURAL_EXPRESSION libintl_gettext_extract_plural
 106 #else
 107 # define FREE_EXPRESSION free_plural_expression
 108 # define PLURAL_PARSE parse_plural_expression
 109 # define GERMANIC_PLURAL germanic_plural
 110 # define EXTRACT_PLURAL_EXPRESSION extract_plural_expression
 111 #endif
 112
 113 extern void FREE_EXPRESSION PARAMS ((struct expression *exp))
 114      internal_function;
 115 extern int PLURAL_PARSE PARAMS ((void *arg));
 116 extern struct expression GERMANIC_PLURAL attribute_hidden;
 117 extern void EXTRACT_PLURAL_EXPRESSION PARAMS ((const char *nullentry,
 118                                                struct expression **pluralp,
 119                                                unsigned long int *npluralsp))
 120      internal_function;
 121
 122 #if !defined (_LIBC) && !defined (IN_LIBINTL)
 123 extern unsigned long int plural_eval PARAMS ((struct expression *pexp,
 124                                               unsigned long int n));
 125 #endif
 126
 127 #endif /* _PLURAL_EXP_H */