se.lth.cs.nlp.nlputils.pstree
Class PSTree

java.lang.Object
  se.lth.cs.nlp.nlputils.pstree.PSTree

public class PSTree
extends Object

A phrase structure tree.

Author:

Richard Johansson (richard@cs.lth.se)

Field Summary

ArrayList<Node>	heads The heads.
ArrayList<Node>	nodes The nodes.
ArrayList<TokenNode>	tokens The tokens.
Node	topnode The top node.

Constructor Summary

PSTree()

Method Summary

static PSTree	collinsTree(String line) Creates a parse tree from a string containing a tree in Collins' format, that is a phrase structure tree with heads.
int	countEndPunc(Node n) Returns the number of punctuation tokens that the node n ends with.
static PSTree	pennTree(String line) Creates a parse tree from a string containing a tree in the Penn Treebank format.
static PSTree	pennTreeWithLemmas(String line) Creates a parse tree from a string containing a tree in the Penn Treebank format with lemmas.
String	tabbedOutput() Returns an indented string representing this tree.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

topnode

public Node topnode

The top node.

tokens

public ArrayList<TokenNode> tokens

The tokens.

heads

public ArrayList<Node> heads

The heads.

nodes

public ArrayList<Node> nodes

The nodes.

Constructor Detail

PSTree

PSTree()

Method Detail

collinsTree

public static PSTree collinsTree(String line)

Creates a parse tree from a string containing a tree in Collins' format, that is a phrase structure tree with heads.

Parameters:

line - the string.

Returns:

the constructed tree.

pennTree

public static PSTree pennTree(String line)

Creates a parse tree from a string containing a tree in the Penn Treebank format. Uses Collins' head finder to find the heads.

Parameters:

line - the string.

Returns:

the constructed tree.

pennTreeWithLemmas

public static PSTree pennTreeWithLemmas(String line)

Creates a parse tree from a string containing a tree in the Penn Treebank format with lemmas. Uses Collins' head finder to find the heads.

Parameters:

line - the string.

Returns:

the constructed tree.

toString

public String toString()

Overrides:

toString in class Object

countEndPunc

public int countEndPunc(Node n)

Returns the number of punctuation tokens that the node n ends with.

Parameters:

n - the node.

Returns:

the number of punctuation tokens.

tabbedOutput

public String tabbedOutput()

Returns an indented string representing this tree.

Returns:

the indented string.