edu.stanford.nlp.trees
Class Trees

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

public class Trees
extends Object

Various utilities for the Tree class.

Author:

Roger Levy

Constructor Summary

Trees()

Method Summary

static Tree	applyToProjections(TreeVisitor v, Tree head, Tree root, HeadFinder hf)
static Tree	getPreTerminal(Tree tree, int n) gets the nth preterminal in tree.
static Tree	getTerminal(Tree tree, int n) gets the nth terminal in tree.
static boolean	heads(Tree head, Tree node, HeadFinder hf) returns true iff head (transitively) heads node
static List	leaves(Tree t) returns the leaves in a Tree in the order that they're found.
static int	leftEdge(Tree t, Tree root) Returns the positional index of the left edge of a tree t within a given root, as defined by the size of the yield of all material preceding t.
static Tree	lexicalize(Tree t, HeadFinder hf) Returns a lexicalized Tree whose Labels are CategoryWordTag instances, all corresponds to the input tree.
static List	localTreeAsCatList(Tree t) returns the syntactic category of the tree as a list of the syntactic categories of the mother and the daughters
static Tree	maximalProjection(Tree head, Tree root, HeadFinder hf) returns the maximal projection of head in root given a HeadFinder
static int	objectEqualityIndexOf(Tree parent, Tree daughter) Returns the index of daughter in parent by ==.
static int	rightEdge(Tree t, Tree root) Returns the positional index of the right edge of a tree t within a given root, as defined by the size of the yield of all material preceding t plus all the material contained in t.

Methods inherited from class java.lang.Object

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

Constructor Detail

Trees

public Trees()

Method Detail

leftEdge

public static int leftEdge(Tree t,
                           Tree root)

Returns the positional index of the left edge of a tree t within a given root, as defined by the size of the yield of all material preceding t.

rightEdge

public static int rightEdge(Tree t,
                            Tree root)

Returns the positional index of the right edge of a tree t within a given root, as defined by the size of the yield of all material preceding t plus all the material contained in t.

lexicalize

public static Tree lexicalize(Tree t,
                              HeadFinder hf)

Returns a lexicalized Tree whose Labels are CategoryWordTag instances, all corresponds to the input tree.

leaves

public static List leaves(Tree t)

returns the leaves in a Tree in the order that they're found.

heads

public static boolean heads(Tree head,
                            Tree node,
                            HeadFinder hf)

returns true iff head (transitively) heads node

maximalProjection

public static Tree maximalProjection(Tree head,
                                     Tree root,
                                     HeadFinder hf)

returns the maximal projection of head in root given a HeadFinder

applyToProjections

public static Tree applyToProjections(TreeVisitor v,
                                      Tree head,
                                      Tree root,
                                      HeadFinder hf)

getTerminal

public static Tree getTerminal(Tree tree,
                               int n)

gets the nth terminal in tree. The first terminal is number zero.

getPreTerminal

public static Tree getPreTerminal(Tree tree,
                                  int n)

gets the nth preterminal in tree. The first terminal is number zero.

localTreeAsCatList

public static List localTreeAsCatList(Tree t)

returns the syntactic category of the tree as a list of the syntactic categories of the mother and the daughters

objectEqualityIndexOf

public static int objectEqualityIndexOf(Tree parent,
                                        Tree daughter)

Returns the index of daughter in parent by ==. Returns -1 if daughter not found.