fido.grammar
Class AlwaysExpression

java.lang.Object
  |
  +--fido.grammar.AlwaysExpression

All Implemented Interfaces:

BooleanTreeNode, Expression

public class AlwaysExpression

extends java.lang.Object

implements Expression

The special node for a grammar string is a compliment for an optional expressionn. When building a grammar tree, if an expression is optional, the expression is placed on the left side of an OR, with an AlwaysNode on the right. Therefore, even if the expression does not show up during parsing, the expresssion will evaluate to true.

Constructor Summary

AlwaysExpression()
Creates an ALWAYS_TYPE node.

Method Summary

AlwaysExpression

cloneExpression() Creates a new AlwaysExpression.

Methods inherited from class java.lang.Object

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

Constructor Detail

AlwaysExpression

public AlwaysExpression()

Creates an ALWAYS_TYPE node. This node in the grammar is alwasy true. It is used for optional expressions.

Method Detail

cloneExpression

public AlwaysExpression cloneExpression()

Creates a new AlwaysExpression.

Returns:

a new AlwaysExpression