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/*
* Copyright (C) 1999, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2011
* Free Software Foundation, Inc.
*
* This file is part of GNU libmatheval
*
* GNU libmatheval is free software: you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* GNU libmatheval 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU libmatheval. If not, see
* <http://www.gnu.org/licenses/>.
*/
%{
/*
* Copyright (C) 1999, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2011
* Free Software Foundation, Inc.
*
* GNU libmatheval is free software: you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* GNU libmatheval 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU libmatheval. If not, see
* <http://www.gnu.org/licenses/>.
*/
#if HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdlib.h>
#include "node.h"
/* Variables used to communicate with code using parser. */
extern Node* root; /* Root of tree representation of function. */
extern SymbolTable *symbol_table; /* Evaluator symbol table. */
extern int ok; /* Flag representing success of parsing. */
/* Report parsing error. */
int yyerror (char *s);
/* Function used to tokenize string representing function (this function
* is generated by scanner generator). */
extern int yylex (void);
/* Function used to reset string representing function (this function is
* generated by scanner generator). */
extern void input_reset (void);
%}
/* Parser semantic values type. */
%union {
Node *node;
Record *record;
}
/* Grammar terminal symbols. */
%token <node> NUMBER CONSTANT VARIABLE
%token <record> FUNCTION
%left '-' '+'
%left '*' '/'
%left NEG
%left '^'
%token END
/* Grammar non-terminal symbols. */
%type <node> expression
/* Grammar start non-terminal. */
%start input
%%
input
: expression '\n' {
root = $1;
}
;
expression
: NUMBER
| CONSTANT
| VARIABLE
| expression '+' expression {
/* Create addition binary operation node. */
$$ = node_create ('b', '+', $1, $3);
}
| expression '-' expression {
/* Create subtraction binary operation node. */
$$ = node_create ('b', '-', $1, $3);
}
| expression '*' expression {
/* Create multiplication binary operation node. */
$$ = node_create ('b', '*', $1, $3);
}
| expression '/' expression {
/* Create division binary operation node. */
$$ = node_create ('b', '/', $1, $3);
}
| '-' expression %prec NEG {
/* Create minus unary operation node. */
$$ = node_create ('u', '-', $2);
}
| expression '^' expression {
/* Create exponentiation unary operation node. */
$$ = node_create ('b', '^', $1, $3);
}
| FUNCTION '(' expression ')' {
/* Create function node. */
$$ = node_create ('f', $1, $3);
}
| '(' expression ')' {
$$ = $2;
}
;
%%
int yyerror(char* s)
{
/* Indicate parsing error through appropriate flag, reset input
* string and stop parsing. */
ok = 0;
input_reset();
return 0;
}
|
