parsii.eval

Class Constant

java.lang.Object

parsii.eval.Constant

All Implemented Interfaces:

Expression

public class Constant
extends Object
implements Expression

Represents a constant numeric expression.

Field Summary

Fields

Modifier and Type	Field and Description
static Constant	EMPTY Used as dummy expression by the parser if an error occurs while parsing.

Constructor Summary

Constructors

Constructor and Description
Constant(double value)

Method Summary

Modifier and Type	Method and Description
double	evaluate() Evaluates the expression to a double number.
boolean	isConstant() Determines the this expression is constant
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface parsii.eval.Expression

simplify

Field Detail

EMPTY

public static final Constant EMPTY

Used as dummy expression by the parser if an error occurs while parsing.

Constructor Detail

Constant

public Constant(double value)

Method Detail

evaluate

public double evaluate()

Description copied from interface: Expression

Evaluates the expression to a double number.

Specified by:

evaluate in interface Expression

Returns:

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

isConstant

public boolean isConstant()

Description copied from interface: Expression

Determines the this expression is constant

Specified by:

isConstant in interface Expression

Returns:

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

toString

public String toString()

Overrides:

toString in class Object