parsii.eval

Class Expression

java.lang.Object

parsii.eval.Expression

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

BinaryOperation, Constant, FunctionCall, VariableReference

public abstract class Expression
extends Object
implements Serializable

Represents the result of a parsed expression.

Can be evaluated to return a double value. If an error occurs Double.NaN will be returned.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
Expression()

Method Summary

Modifier and Type	Method and Description
abstract double	evaluate() Evaluates the expression to a double number.
boolean	isConstant() Determines the this expression is constant
Expression	simplify() Returns a simplified version of this expression.

Methods inherited from class java.lang.Object

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

Constructor Detail

Expression

public Expression()

Method Detail

evaluate

public abstract double evaluate()

Evaluates the expression to a double number.

Returns:

the double value as a result of evaluating this expression. Returns NaN if an error occurs

simplify

public Expression simplify()

Returns a simplified version of this expression.

Returns:

a simplified version of this expression or this if the expression cannot be simplified

isConstant

public boolean isConstant()

Determines the this expression is constant

Returns:

true if the result of evaluate will never change and does not depend on external state like variables