intl/plural-exp.h

   1 /* Expression parsing and evaluation for plural form selection.
   2    Copyright (C) 2000-2017 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
   6    it under the terms of the GNU Lesser General Public License as published by
   7    the Free Software Foundation; either version 2.1 of the License, or
   8    (at your option) 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
  13    GNU Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _PLURAL_EXP_H
  19 #define _PLURAL_EXP_H
  20
  21 #ifndef attribute_hidden
  22 # define attribute_hidden
  23 #endif
  24
  25 #ifdef __cplusplus
  26 extern "C" {
  27 #endif
  28
  29
  30 enum expression_operator
  31 {
  32   /* Without arguments:  */
  33   var,                          /* The variable "n".  */
  34   num,                          /* Decimal number.  */
  35   /* Unary operators:  */
  36   lnot,                         /* Logical NOT.  */
  37   /* Binary operators:  */
  38   mult,                         /* Multiplication.  */
  39   divide,                       /* Division.  */
  40   module,                       /* Modulo operation.  */
  41   plus,                         /* Addition.  */
  42   minus,                        /* Subtraction.  */
  43   less_than,                    /* Comparison.  */
  44   greater_than,                 /* Comparison.  */
  45   less_or_equal,                /* Comparison.  */
  46   greater_or_equal,             /* Comparison.  */
  47   equal,                        /* Comparison for equality.  */
  48   not_equal,                    /* Comparison for inequality.  */
  49   land,                         /* Logical AND.  */
  50   lor,                          /* Logical OR.  */
  51   /* Ternary operators:  */
  52   qmop                          /* Question mark operator.  */
  53 };
  54
  55 /* This is the representation of the expressions to determine the
  56    plural form.  */
  57 struct expression
  58 {
  59   int nargs;                    /* Number of arguments.  */
  60   enum expression_operator operation;
  61   union
  62   {
  63     unsigned long int num;      /* Number value for `num'.  */
  64     struct expression *args[3]; /* Up to three arguments.  */
  65   } val;
  66 };
  67
  68 /* This is the data structure to pass information to the parser and get
  69    the result in a thread-safe way.  */
  70 struct parse_args
  71 {
  72   const char *cp;
  73   struct expression *res;
  74 };
  75
  76
  77 /* Names for the libintl functions are a problem.  This source code is used
  78    1. in the GNU C Library library,
  79    2. in the GNU libintl library,
  80    3. in the GNU gettext tools.
  81    The function names in each situation must be different, to allow for
  82    binary incompatible changes in 'struct expression'.  Furthermore,
  83    1. in the GNU C Library library, the names have a __ prefix,
  84    2.+3. in the GNU libintl library and in the GNU gettext tools, the names
  85          must follow ANSI C and not start with __.
  86    So we have to distinguish the three cases.  */
  87 #ifdef _LIBC
  88 # define FREE_EXPRESSION __gettext_free_exp
  89 # define PLURAL_PARSE __gettextparse
  90 # define GERMANIC_PLURAL __gettext_germanic_plural
  91 # define EXTRACT_PLURAL_EXPRESSION __gettext_extract_plural
  92 #elif defined (IN_LIBINTL)
  93 # define FREE_EXPRESSION libintl_gettext_free_exp
  94 # define PLURAL_PARSE libintl_gettextparse
  95 # define GERMANIC_PLURAL libintl_gettext_germanic_plural
  96 # define EXTRACT_PLURAL_EXPRESSION libintl_gettext_extract_plural
  97 #else
  98 # define FREE_EXPRESSION free_plural_expression
  99 # define PLURAL_PARSE parse_plural_expression
 100 # define GERMANIC_PLURAL germanic_plural
 101 # define EXTRACT_PLURAL_EXPRESSION extract_plural_expression
 102 #endif
 103
 104 extern void FREE_EXPRESSION (struct expression *exp);
 105 extern int PLURAL_PARSE (struct parse_args *arg);
 106 extern const struct expression GERMANIC_PLURAL attribute_hidden;
 107 extern void EXTRACT_PLURAL_EXPRESSION (const char *nullentry,
 108                                        const struct expression **pluralp,
 109                                        unsigned long int *npluralsp);
 110
 111 #if !defined (_LIBC) && !defined (IN_LIBINTL) && !defined (IN_LIBGLOCALE)
 112 extern unsigned long int plural_eval (const struct expression *pexp,
 113                                       unsigned long int n);
 114 #endif
 115
 116
 117 #ifdef __cplusplus
 118 }
 119 #endif
 120
 121 #endif /* _PLURAL_EXP_H */