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Diffstat (limited to 'intl/plural.y')
| -rw-r--r-- | intl/plural.y | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/intl/plural.y b/intl/plural.y new file mode 100644 index 0000000..fe79112 --- /dev/null +++ b/intl/plural.y @@ -0,0 +1,381 @@ +%{ +/* Expression parsing for plural form selection. + Copyright (C) 2000-2001, 2003 Free Software Foundation, Inc. + Written by Ulrich Drepper <drepper@cygnus.com>, 2000. + + This program is free software; you can redistribute it and/or modify it + under the terms of the GNU Library General Public License as published + by the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, + USA. */ + +/* The bison generated parser uses alloca. AIX 3 forces us to put this + declaration at the beginning of the file. The declaration in bison's + skeleton file comes too late. This must come before <config.h> + because <config.h> may include arbitrary system headers. */ +#if defined _AIX && !defined __GNUC__ + #pragma alloca +#endif + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <stddef.h> +#include <stdlib.h> +#include "plural-exp.h" + +/* The main function generated by the parser is called __gettextparse, + but we want it to be called PLURAL_PARSE. */ +#ifndef _LIBC +# define __gettextparse PLURAL_PARSE +#endif + +#define YYLEX_PARAM &((struct parse_args *) arg)->cp +#define YYPARSE_PARAM arg +%} +%pure_parser +%expect 7 + +%union { + unsigned long int num; + enum operator op; + struct expression *exp; +} + +%{ +/* Prototypes for local functions. */ +static int yylex (YYSTYPE *lval, const char **pexp); +static void yyerror (const char *str); + +/* Allocation of expressions. */ + +static struct expression * +new_exp (int nargs, enum operator op, struct expression * const *args) +{ + int i; + struct expression *newp; + + /* If any of the argument could not be malloc'ed, just return NULL. */ + for (i = nargs - 1; i >= 0; i--) + if (args[i] == NULL) + goto fail; + + /* Allocate a new expression. */ + newp = (struct expression *) malloc (sizeof (*newp)); + if (newp != NULL) + { + newp->nargs = nargs; + newp->operation = op; + for (i = nargs - 1; i >= 0; i--) + newp->val.args[i] = args[i]; + return newp; + } + + fail: + for (i = nargs - 1; i >= 0; i--) + FREE_EXPRESSION (args[i]); + + return NULL; +} + +static inline struct expression * +new_exp_0 (enum operator op) +{ + return new_exp (0, op, NULL); +} + +static inline struct expression * +new_exp_1 (enum operator op, struct expression *right) +{ + struct expression *args[1]; + + args[0] = right; + return new_exp (1, op, args); +} + +static struct expression * +new_exp_2 (enum operator op, struct expression *left, struct expression *right) +{ + struct expression *args[2]; + + args[0] = left; + args[1] = right; + return new_exp (2, op, args); +} + +static inline struct expression * +new_exp_3 (enum operator op, struct expression *bexp, + struct expression *tbranch, struct expression *fbranch) +{ + struct expression *args[3]; + + args[0] = bexp; + args[1] = tbranch; + args[2] = fbranch; + return new_exp (3, op, args); +} + +%} + +/* This declares that all operators have the same associativity and the + precedence order as in C. See [Harbison, Steele: C, A Reference Manual]. + There is no unary minus and no bitwise operators. + Operators with the same syntactic behaviour have been merged into a single + token, to save space in the array generated by bison. */ +%right '?' /* ? */ +%left '|' /* || */ +%left '&' /* && */ +%left EQUOP2 /* == != */ +%left CMPOP2 /* < > <= >= */ +%left ADDOP2 /* + - */ +%left MULOP2 /* * / % */ +%right '!' /* ! */ + +%token <op> EQUOP2 CMPOP2 ADDOP2 MULOP2 +%token <num> NUMBER +%type <exp> exp + +%% + +start: exp + { + if ($1 == NULL) + YYABORT; + ((struct parse_args *) arg)->res = $1; + } + ; + +exp: exp '?' exp ':' exp + { + $$ = new_exp_3 (qmop, $1, $3, $5); + } + | exp '|' exp + { + $$ = new_exp_2 (lor, $1, $3); + } + | exp '&' exp + { + $$ = new_exp_2 (land, $1, $3); + } + | exp EQUOP2 exp + { + $$ = new_exp_2 ($2, $1, $3); + } + | exp CMPOP2 exp + { + $$ = new_exp_2 ($2, $1, $3); + } + | exp ADDOP2 exp + { + $$ = new_exp_2 ($2, $1, $3); + } + | exp MULOP2 exp + { + $$ = new_exp_2 ($2, $1, $3); + } + | '!' exp + { + $$ = new_exp_1 (lnot, $2); + } + | 'n' + { + $$ = new_exp_0 (var); + } + | NUMBER + { + if (($$ = new_exp_0 (num)) != NULL) + $$->val.num = $1; + } + | '(' exp ')' + { + $$ = $2; + } + ; + +%% + +void +internal_function +FREE_EXPRESSION (struct expression *exp) +{ + if (exp == NULL) + return; + + /* Handle the recursive case. */ + switch (exp->nargs) + { + case 3: + FREE_EXPRESSION (exp->val.args[2]); + /* FALLTHROUGH */ + case 2: + FREE_EXPRESSION (exp->val.args[1]); + /* FALLTHROUGH */ + case 1: + FREE_EXPRESSION (exp->val.args[0]); + /* FALLTHROUGH */ + default: + break; + } + + free (exp); +} + + +static int +yylex (YYSTYPE *lval, const char **pexp) +{ + const char *exp = *pexp; + int result; + + while (1) + { + if (exp[0] == '\0') + { + *pexp = exp; + return YYEOF; + } + + if (exp[0] != ' ' && exp[0] != '\t') + break; + + ++exp; + } + + result = *exp++; + switch (result) + { + case '0': case '1': case '2': case '3': case '4': + case '5': case '6': case '7': case '8': case '9': + { + unsigned long int n = result - '0'; + while (exp[0] >= '0' && exp[0] <= '9') + { + n *= 10; + n += exp[0] - '0'; + ++exp; + } + lval->num = n; + result = NUMBER; + } + break; + + case '=': + if (exp[0] == '=') + { + ++exp; + lval->op = equal; + result = EQUOP2; + } + else + result = YYERRCODE; + break; + + case '!': + if (exp[0] == '=') + { + ++exp; + lval->op = not_equal; + result = EQUOP2; + } + break; + + case '&': + case '|': + if (exp[0] == result) + ++exp; + else + result = YYERRCODE; + break; + + case '<': + if (exp[0] == '=') + { + ++exp; + lval->op = less_or_equal; + } + else + lval->op = less_than; + result = CMPOP2; + break; + + case '>': + if (exp[0] == '=') + { + ++exp; + lval->op = greater_or_equal; + } + else + lval->op = greater_than; + result = CMPOP2; + break; + + case '*': + lval->op = mult; + result = MULOP2; + break; + + case '/': + lval->op = divide; + result = MULOP2; + break; + + case '%': + lval->op = module; + result = MULOP2; + break; + + case '+': + lval->op = plus; + result = ADDOP2; + break; + + case '-': + lval->op = minus; + result = ADDOP2; + break; + + case 'n': + case '?': + case ':': + case '(': + case ')': + /* Nothing, just return the character. */ + break; + + case ';': + case '\n': + case '\0': + /* Be safe and let the user call this function again. */ + --exp; + result = YYEOF; + break; + + default: + result = YYERRCODE; +#if YYDEBUG != 0 + --exp; +#endif + break; + } + + *pexp = exp; + + return result; +} + + +static void +yyerror (const char *str) +{ + /* Do nothing. We don't print error messages here. */ +} |