com.eteks.parser.node
Class ConstantNode

java.lang.Object
  |
  +--com.eteks.parser.node.ConstantNode

All Implemented Interfaces:

ExpressionNode, java.io.Serializable

Direct Known Subclasses:

BinaryOperatorNode, CommonFunctionNode, UnaryOperatorNode

public class ConstantNode

extends java.lang.Object

implements ExpressionNode

Node matching a constant.

Since:

Jeks 1.0

Version:

1.0

Author:

Emmanuel Puybaret

See Also:

Serialized Form

Field Summary

static double	FALSE_DOUBLE The double constant matching the constant FALSE (equal to 0).
static double	TRUE_DOUBLE The double constant matching the constant TRUE (equal to 1).

Constructor Summary

ConstantNode(java.lang.Object key)
Creates the node of a constant.

Method Summary

double	computeExpression(double[] parametersValue) Returns the double value of this constant.
java.lang.Object	computeExpression(Interpreter interpreter, java.lang.Object[] parametersValue) Returns the value returned by the getConstantValue () method of interpreter with the key of this constant as parameter.
java.lang.Object	getKey() Returns the syntactic key of this node.

Methods inherited from class java.lang.Object

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

Field Detail

FALSE_DOUBLE

public static final double FALSE_DOUBLE

The double constant matching the constant FALSE (equal to 0).

TRUE_DOUBLE

public static final double TRUE_DOUBLE

The double constant matching the constant TRUE (equal to 1).

Constructor Detail

ConstantNode

public ConstantNode(java.lang.Object key)

Creates the node of a constant.

Parameters:

key - the key of a constant of Syntax.

Method Detail

getKey

public java.lang.Object getKey()

Returns the syntactic key of this node.

Returns:

a key of Syntax.

computeExpression

public java.lang.Object computeExpression(Interpreter interpreter,
                                          java.lang.Object[] parametersValue)

Returns the value returned by the getConstantValue () method of interpreter with the key of this constant as parameter.

Specified by:

computeExpression in interface ExpressionNode

Parameters:

interpreter - runtime interpreter.

parametersValue - not used.

Returns:

the interpreted value of this constant. The type of the returned value depends on the implementation of the interpreter.

See Also:

Interpreter.getConstantValue(java.lang.Object)

computeExpression

public double computeExpression(double[] parametersValue)

Returns the double value of this constant. The value FALSE_DOUBLE is returned for the CONSTANT_FALSE constant key, and the value TRUE_DOUBLE is returned for the CONSTANT_TRUE constant key.

Specified by:

computeExpression in interface ExpressionNode

Parameters:

parametersValue - not used.

Returns:

the value of this constant.