com.canoo.webtest.util
Class Expression

java.lang.Object
  com.canoo.webtest.util.Expression

public class Expression
extends Object

Evaluates a mathematical expression.

Author:

Paul King, Rob Nielsen

Constructor Summary

Expression()
Constructs a new blank expression

Expression(Evaluator eval)
Constructor for the Expression object

Method Summary

double	evaluate(String exp) Evaluates the expression string and returns the result (which is also available with getValue()).
static double	evaluateExpression(String s) Evaluates a string expression without requiring the creation of an instance.
static double	evaluateExpression(String s, Evaluator eval) Evaluates a string expression without requiring the creation of an instance.
protected double	evaluateString(String s) Evaluates a string found in the expression which isn't an arithmetic expression.
void	setEvaluator(Evaluator evaluator) Sets the Evaluator attribute of the Expression object

Methods inherited from class java.lang.Object

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

Constructor Detail

Expression

public Expression()

Constructs a new blank expression

Expression

public Expression(Evaluator eval)

Constructor for the Expression object

Parameters:

eval - the fEvaluator to use for unknown expressions

Method Detail

setEvaluator

public void setEvaluator(Evaluator evaluator)

Sets the Evaluator attribute of the Expression object

Parameters:

evaluator - The new Evaluator value

evaluate

public double evaluate(String exp)

Evaluates the expression string and returns the result (which is also available with getValue()). Any parse errors will throw a IllegalArgumentException

Parameters:

exp - the string to parse

Returns:

the double value of the expression

Throws:

IllegalArgumentException

evaluateString

protected double evaluateString(String s)

Evaluates a string found in the expression which isn't an arithmetic expression. Calls out to the given fEvaluator.

Parameters:

s - the substring to evaluate

Returns:

the double value of the evaluation

evaluateExpression

public static double evaluateExpression(String s)

Evaluates a string expression without requiring the creation of an instance.

Parameters:

s - the expression to evaluate

Returns:

the double value of the expression

evaluateExpression

public static double evaluateExpression(String s,
                                        Evaluator eval)

Evaluates a string expression without requiring the creation of an instance.

Parameters:

s - the expression to evaluate

eval - the fEvaluator to parse special values

Returns:

the double value of the expression