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: ExprCalc.java,v 1.12 2004/09/29 14:29:24 pierre Exp $

Author:

Arnold Beck

Constructor Summary

ExprCalc(String input)
Constructor of ExrpCalc

Method Summary

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