edu.stanford.nlp.trees
Class RecursiveTreeTransformer

java.lang.Object
  edu.stanford.nlp.trees.RecursiveTreeTransformer

All Implemented Interfaces:

TreeTransformer

Direct Known Subclasses:

BasicCategoryTreeTransformer

public abstract class RecursiveTreeTransformer
extends java.lang.Object
implements TreeTransformer

A tool to recursively alter a tree in various ways. For example, BasicCategoryTreeTransformer turns all the non-leaf labels of a tree into their basic categories given a set of treebank parameters which describe how to turn the basic categories.
There are three easy places to override and implement the needed behavior. transformTerminalLabel changes the labels of the terminals, transformNonterminalLabel changes the labels of the non-terminals, and transformLabel changes all labels. If the tree needs to be changed in different ways, transformTerminal or transformNonterminal can be used instead.

Author:

John Bauer

Constructor Summary

RecursiveTreeTransformer()

Method Summary

Tree	transformHelper(Tree tree)
Label	transformLabel(Tree tree)
Tree	transformNonterminal(Tree tree)
Label	transformNonterminalLabel(Tree tree)
Tree	transformTerminal(Tree tree)
Label	transformTerminalLabel(Tree tree)
Tree	transformTree(Tree tree) Does whatever one needs to do to a particular tree.

Methods inherited from class java.lang.Object

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

Constructor Detail

RecursiveTreeTransformer

public RecursiveTreeTransformer()

Method Detail

transformTree

public Tree transformTree(Tree tree)

Description copied from interface: TreeTransformer

Does whatever one needs to do to a particular tree. This routine is passed a whole Tree, and could itself work recursively, but the canonical usage is to invoke this method via the Tree.transform() method, which will apply the transformer in a bottom-up manner to each local Tree, and hence the implementation of TreeTransformer should merely examine and change a local (one-level) Tree.

Specified by:

transformTree in interface TreeTransformer

Parameters:

tree - A tree. Classes implementing this interface can assume that the tree passed in is not null.

Returns:

the transformed Tree

transformHelper

public Tree transformHelper(Tree tree)

transformTerminal

public Tree transformTerminal(Tree tree)

transformNonterminal

public Tree transformNonterminal(Tree tree)

transformTerminalLabel

public Label transformTerminalLabel(Tree tree)

transformNonterminalLabel

public Label transformNonterminalLabel(Tree tree)

transformLabel

public Label transformLabel(Tree tree)