fido.grammar
Class NodeExpression

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

All Implemented Interfaces:

BooleanTreeNode, Expression

public class NodeExpression

extends java.lang.Object

implements Expression

The basic component for a grammar string. Each node contains a String value for the name of the node, a direction the expression links to, whether the node can match multiple nodes, and the next expression node in the full expression.

In the expression, A+ & B-, each A+ and B- would create an NodeExpression class, where A would create a class with the string 'A' as the name, and DIR_RIGHT as the direction.

Field Summary

static int	DIR_LEFT Value for Direction indicating the expression will link to the left
static int	DIR_RIGHT Value for Direction indicating the expression will link to the right

Constructor Summary

NodeExpression(java.lang.String name, int direction, boolean multi)
Creates a NODE_TYPE node.

Method Summary

NodeExpression	cloneExpression() Creates a new NodeExpression with the same values as this expression.
int	getDirection() Returns the direction the expression will match.
java.lang.String	getExpressionName() Returns the link name of the expression.
boolean	isMultiNodeUsed() Returns if the node has been used at least once, which makes it valid.
boolean	isNodeMulti() Returns true if the node is a multi node.
void	setMultiNode() Sets the node to be a multi node, which means it can match one to many nodes in a grammar.
void	setMultiNodeUsed() Sets this node as used at least once in a grammar.

Methods inherited from class java.lang.Object

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

Field Detail

DIR_LEFT

public static final int DIR_LEFT

Value for Direction indicating the expression will link to the left

See Also:

Constant Field Values

DIR_RIGHT

public static final int DIR_RIGHT

Value for Direction indicating the expression will link to the right

See Also:

Constant Field Values

Constructor Detail

NodeExpression

public NodeExpression(java.lang.String name,
                      int direction,
                      boolean multi)

Creates a NODE_TYPE node.

Method Detail

isNodeMulti

public boolean isNodeMulti()

Returns true if the node is a multi node.

Returns:

true if the node is a multi node.

setMultiNode

public void setMultiNode()

Sets the node to be a multi node, which means it can match one to many nodes in a grammar.

isMultiNodeUsed

public boolean isMultiNodeUsed()

Returns if the node has been used at least once, which makes it valid.

Returns:

true if the node has been used at least once.

See Also:

setMultiNodeUsed()

setMultiNodeUsed

public void setMultiNodeUsed()

Sets this node as used at least once in a grammar.

See Also:

isMultiNodeUsed()

getDirection

public int getDirection()

Returns the direction the expression will match.

• DIR_LEFT - matches an expression previously.
• DIR_RIGHT - places this expression on the stack to match later.

See Also:

DIR_LEFT, DIR_RIGHT

getExpressionName

public java.lang.String getExpressionName()

Returns the link name of the expression.

Returns:

String containing the link name of the expression.

cloneExpression

public NodeExpression cloneExpression()

Creates a new NodeExpression with the same values as this expression.

Returns:

a new NodeExpression containing the same values