edu.stanford.nlp.parser.lexparser.HookChart Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of stanford-parser Show documentation
Show all versions of stanford-parser Show documentation
Stanford Parser processes raw text in English, Chinese, German, Arabic, and French, and extracts constituency parse trees.
package edu.stanford.nlp.parser.lexparser;
import java.util.*;
import edu.stanford.nlp.util.Generics;
/**
* A HookChart is a chart data structure designed for use with the efficient
* O(n^4) chart parsing mechanisms targetted at lexicalized parsing, which
* were introduced by Eisner and Satta.
*
* @author Dan Klein
*/
class HookChart {
private Map> registeredPreHooks = Generics.newHashMap();
private Map> registeredPostHooks = Generics.newHashMap();
private Map> registeredEdgesByLeftIndex = Generics.newHashMap();
private Map> registeredEdgesByRightIndex = Generics.newHashMap();
private Map> realEdgesByL = Generics.newHashMap();
private Map> realEdgesByR = Generics.newHashMap();
private Set builtLIndexes = Generics.newHashSet();
private Set builtRIndexes = Generics.newHashSet();
private Interner interner = new Interner();
private static class ChartIndex {
public int state;
public int head;
public int tag;
public int loc; // either the start or end of an edge
@Override
public int hashCode() {
return state ^ (head << 8) ^ (tag << 16) ^ (loc << 24);
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o instanceof ChartIndex) {
ChartIndex ci = (ChartIndex) o;
return state == ci.state && head == ci.head && tag == ci.tag && loc == ci.loc;
}
return false;
}
} // end class ChartIndex
private static class WeakChartIndex {
public int state;
public int loc; // either the start or end of an edge
@Override
public int hashCode() {
return state ^ (loc << 16);
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o instanceof WeakChartIndex) {
WeakChartIndex ci = (WeakChartIndex) o;
return state == ci.state && loc == ci.loc;
}
return false;
}
}
private static final Collection empty = Collections.emptyList();
private static final Collection emptyHooks = Collections.emptyList();
private ChartIndex tempIndex = new ChartIndex(); // used in many methods to decrease new's
private WeakChartIndex tempWeakIndex = new WeakChartIndex(); // used to decrease new's
public void registerEdgeIndexes(Edge edge) {
tempIndex.state = edge.state;
tempIndex.head = edge.head;
tempIndex.tag = edge.tag;
tempIndex.loc = edge.start;
ChartIndex index = (ChartIndex) interner.intern(tempIndex);
builtLIndexes.add(index);
if (index == tempIndex) {
tempIndex = new ChartIndex();
tempIndex.state = edge.state;
tempIndex.head = edge.head;
tempIndex.tag = edge.tag;
}
//System.out.println("Edge registered: "+edge);
tempIndex.loc = edge.end;
index = (ChartIndex) interner.intern(tempIndex);
if (index == tempIndex) {
tempIndex = new ChartIndex();
}
builtRIndexes.add(index);
}
public void registerRealEdge(Edge edge) {
tempWeakIndex.state = edge.state;
tempWeakIndex.loc = edge.start;
WeakChartIndex index = (WeakChartIndex) interner.intern(tempWeakIndex);
insert(realEdgesByL, index, edge);
if (index == tempWeakIndex) {
tempWeakIndex = new WeakChartIndex();
tempWeakIndex.state = edge.state;
}
tempWeakIndex.loc = edge.end;
index = (WeakChartIndex) interner.intern(tempWeakIndex);
insert(realEdgesByR, index, edge);
if (index == tempWeakIndex) {
tempWeakIndex = new WeakChartIndex();
}
}
public boolean isBuiltL(int state, int start, int head, int tag) {
tempIndex.state = state;
tempIndex.head = head;
tempIndex.tag = tag;
tempIndex.loc = start;
return builtLIndexes.contains(tempIndex);
}
public boolean isBuiltR(int state, int end, int head, int tag) {
tempIndex.state = state;
tempIndex.head = head;
tempIndex.tag = tag;
tempIndex.loc = end;
return builtRIndexes.contains(tempIndex);
}
public Collection getRealEdgesWithL(int state, int start) {
tempWeakIndex.state = state;
tempWeakIndex.loc = start;
Collection edges = realEdgesByL.get(tempWeakIndex);
if (edges == null) {
return empty;
}
return edges;
}
public Collection getRealEdgesWithR(int state, int end) {
tempWeakIndex.state = state;
tempWeakIndex.loc = end;
Collection edges = realEdgesByR.get(tempWeakIndex);
if (edges == null) {
return empty;
}
return edges;
}
public Collection getPreHooks(Edge edge) {
tempIndex.state = edge.state;
tempIndex.head = edge.head;
tempIndex.tag = edge.tag;
tempIndex.loc = edge.end;
Collection result = registeredPreHooks.get(tempIndex);
if (result == null) {
result = emptyHooks;
}
//System.out.println("For "+edge+" returning "+result.size()+" pre hooks");
return result;
}
public Collection getPostHooks(Edge edge) {
tempIndex.state = edge.state;
tempIndex.head = edge.head;
tempIndex.tag = edge.tag;
tempIndex.loc = edge.start;
Collection result = registeredPostHooks.get(tempIndex);
if (result == null) {
result = emptyHooks;
}
//System.out.println("For "+edge+" returning "+result.size()+" post hooks");
return result;
}
public Collection getEdges(Hook hook) {
tempIndex.state = hook.subState;
tempIndex.head = hook.head;
tempIndex.tag = hook.tag;
Collection result;
if (hook.isPreHook()) {
tempIndex.loc = hook.start;
result = registeredEdgesByRightIndex.get(tempIndex);
} else {
tempIndex.loc = hook.end;
result = registeredEdgesByLeftIndex.get(tempIndex);
}
if (result == null) {
result = empty;
}
//System.out.println("For "+hook+" returning "+result.size()+" edges");
return result;
}
// This hacks up a CollectionValuedMap. Maybe convert to using that class?
private static void insert(Map> map, K index, V item) {
List list = map.get(index);
if (list == null) {
// make default size small: many only ever contain 1 or 2 items
list = new ArrayList(3);
map.put(index, list);
}
list.add(item);
// System.err.println("#### HookChart list length is " + list.size());
}
public void addEdge(Edge edge) {
tempIndex.state = edge.state;
tempIndex.head = edge.head;
tempIndex.tag = edge.tag;
// left index
tempIndex.loc = edge.start;
ChartIndex index = (ChartIndex) interner.intern(tempIndex);
insert(registeredEdgesByLeftIndex, index, edge);
if (index == tempIndex) {
tempIndex = new ChartIndex();
tempIndex.state = edge.state;
tempIndex.head = edge.head;
tempIndex.tag = edge.tag;
}
tempIndex.loc = edge.end;
index = (ChartIndex) interner.intern(tempIndex);
insert(registeredEdgesByRightIndex, index, edge);
if (index == tempIndex) {
tempIndex = new ChartIndex();
}
}
public void addHook(Hook hook) {
Map> map;
tempIndex.state = hook.subState;
tempIndex.head = hook.head;
tempIndex.tag = hook.tag;
if (hook.isPreHook()) {
tempIndex.loc = hook.start;
map = registeredPreHooks;
} else {
tempIndex.loc = hook.end;
map = registeredPostHooks;
}
ChartIndex index = (ChartIndex) interner.intern(tempIndex);
insert(map, index, hook);
if (index == tempIndex) {
tempIndex = new ChartIndex();
}
}
} // end class HookChart