org.yawlfoundation.yawl.cost.data

Class ExpressionParser

java.lang.Object

org.yawlfoundation.yawl.cost.data.ExpressionParser

public class ExpressionParser
extends java.lang.Object

Parses and evaluates a numeric expression. Valid operators are + - * and \ (note the backslash for division). Sub-expressions may be parenthesised to any level.

Author:

Michael Adams

Created/Last Date:

15/11/11

Constructor Summary

Constructors

Constructor and Description
ExpressionParser()
ExpressionParser(java.lang.String expr, java.util.Map<java.lang.String,java.lang.String> vars) Creates a new parser

Method Summary

Modifier and Type	Method and Description
double	evaluate() Evaluates a previously added expression
double	evaluate(java.lang.String expr) Evaluates an expression
static void	main(java.lang.String[] args) Unit tests the class with expressions entered from the command line
void	setExpression(java.lang.String expr) Sets the primary expression for this parser
void	setVariables(java.util.Map<java.lang.String,java.lang.String> vars) sets the map of variables and their values for this parser

Methods inherited from class java.lang.Object

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

Constructor Detail

ExpressionParser

public ExpressionParser()

ExpressionParser

public ExpressionParser(java.lang.String expr,
                        java.util.Map<java.lang.String,java.lang.String> vars)

Creates a new parser

Parameters:

expr - the expression to parse

vars - a set of variables and their values

Method Detail

setVariables

public void setVariables(java.util.Map<java.lang.String,java.lang.String> vars)

sets the map of variables and their values for this parser

Parameters:

vars - the map of variables and their values

setExpression

public void setExpression(java.lang.String expr)

Sets the primary expression for this parser

Parameters:

expr - the expression to parse

evaluate

public double evaluate()

Evaluates a previously added expression

Returns:

the result of the evaluation

Throws:

java.lang.NumberFormatException - if the expression is malformed

evaluate

public double evaluate(java.lang.String expr)

Evaluates an expression

Parameters:

expr - the expression to evaluate

Returns:

the result of the evaluation

Throws:

java.lang.NumberFormatException - if the expression is malformed

main

public static void main(java.lang.String[] args)

Unit tests the class with expressions entered from the command line

Parameters:

args - runtime arguments - none required