laser.regularlanguage.util
Class MarkerNode<L extends LabelInterface>

java.lang.Object
  extended by laser.regularlanguage.regularexpression.TreeNode<L>
      extended by laser.regularlanguage.util.MarkerNode<L>
Type Parameters:
L - The type of Label associated with this regular expression
All Implemented Interfaces:
java.io.Serializable, REConstants

public class MarkerNode<L extends LabelInterface>
extends TreeNode<L>

MarkerNode is the special end of regular expression node that is needed in the RE to DFA algorithm. It is a leaf node and is represented by "#".

NOTE: If the root node is the MarkerNode, then this specifies the empty language.

Author:
Jamieson M. Cobleigh (laser-software@cs.umass.edu)
See Also:
Serialized Form

Field Summary
static java.lang.String MARKER
          The string representation of the marker
 
Fields inherited from class laser.regularlanguage.regularexpression.TreeNode
LS
 
Fields inherited from interface laser.regularlanguage.regularexpression.REConstants
CHOICE, COMMA, COMMENT_PREFIX, CONCATENATION, DOT, EMPTY, EPSILON, EXPONENT, KLEENE_PLUS, KLEENE_STAR, LBRACE, LBRACKET, LPAREN, NOT, OPTION, RANGE, RBRACE, RBRACKET, RPAREN
 
Constructor Summary
MarkerNode()
          Creates a new MarkerNode
 
Method Summary
 void apply(REVisitor<L> visitor, java.lang.Object context)
          Applies the given REVisitor to this TreeNode.
 MarkerNode<L> copyTree()
          Returns a copy of the Tree rooted at this node.
 java.util.List<TreeNode<L>> getChildren()
          Returns a List of the children of this TreeNode.
 java.util.Set<L> getLabelsUsed()
          Returns a Set of the labels used by this TreeNode.
 java.lang.String print(java.lang.String prefix)
          Prints the Tree rooted at this node.
 
Methods inherited from class laser.regularlanguage.regularexpression.TreeNode
equalsTree, toString, trace
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

MARKER

public static final java.lang.String MARKER
The string representation of the marker

See Also:
Constant Field Values
Constructor Detail

MarkerNode

public MarkerNode()
Creates a new MarkerNode

Method Detail

apply

public void apply(REVisitor<L> visitor,
                  java.lang.Object context)
           throws REVisitorException
Applies the given REVisitor to this TreeNode.

Specified by:
apply in class TreeNode<L extends LabelInterface>
Parameters:
visitor - The REVisitor to be applied
context - The calling context
Throws:
REVisitorException - if an error occurs

copyTree

public MarkerNode<L> copyTree()
Returns a copy of the Tree rooted at this node. This will fail to terminate if the tree becomes a cyclic graph.

Specified by:
copyTree in class TreeNode<L extends LabelInterface>
Returns:
a copy of the Tree rooted at this node

getChildren

public java.util.List<TreeNode<L>> getChildren()
Returns a List of the children of this TreeNode.

Specified by:
getChildren in class TreeNode<L extends LabelInterface>
Returns:
A List of the children of this TreeNode

getLabelsUsed

public java.util.Set<L> getLabelsUsed()
Returns a Set of the labels used by this TreeNode.

Specified by:
getLabelsUsed in class TreeNode<L extends LabelInterface>
Returns:
A Set of the labels used by this TreeNode

print

public java.lang.String print(java.lang.String prefix)
Prints the Tree rooted at this node. This will fail to terminate if the tree becomes a cyclic graph.

Specified by:
print in class TreeNode<L extends LabelInterface>
Parameters:
prefix - The string to be appended before everything printed for this level. Should be a String of spaces
Returns:
A string representation of this TreeNode