org.mmbase.util

Class ExprCalc

java.lang.Object

org.mmbase.util.ExprCalc

public class ExprCalc
extends Object

Class to calculate expressions. It implements a simple LL(1) grammar to calculate simple expressions with the basic operators +,-,*,/ and brackets.
The grammar in EBNF notation:
<expr> -> <term> { '+' <term> } | <term> { '-' <term> }
<term> -> <fact> { '*' <fact> } | <fact> { '/' <fact> }
<fact> -> <nmeral> | '(' <expr> ')'

Version:

$Id$

Author:

Arnold Beck

Constructor Summary

Constructors

Constructor and Description
ExprCalc(String input) Constructor of ExrpCalc

Method Summary

Modifier and Type	Method and Description
double	getResult() Returns the calculated value of the expression

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ExprCalc

public ExprCalc(String input)

Constructor of ExrpCalc

Parameters:

input - a String representing the expression

Method Detail

getResult

public double getResult()

Returns the calculated value of the expression