1 /* Expression parsing and evaluation for plural form selection.
2    Copyright (C) 2000-2022 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 <https://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) attribute_hidden;
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      attribute_hidden;
111 
112 #if !defined (_LIBC) && !defined (IN_LIBINTL) && !defined (IN_LIBGLOCALE)
113 extern unsigned long int plural_eval (const struct expression *pexp,
114 				      unsigned long int n);
115 #endif
116 
117 
118 #ifdef __cplusplus
119 }
120 #endif
121 
122 #endif /* _PLURAL_EXP_H */
123