[DL-Learner SVN] SF.net SVN: dl-learner:[4177] trunk/components-core/src/main/java/org/ dllearner/algorithms/isle/index/TokenTree.java

[<dfl...@us...>]

Revision: 4177
          http://sourceforge.net/p/dl-learner/code/4177
Author:   dfleischhacker
Date:     2013-12-02 12:51:30 +0000 (Mon, 02 Dec 2013)
Log Message:
-----------
Add TokenTree class

Added Paths:
-----------
    trunk/components-core/src/main/java/org/dllearner/algorithms/isle/index/TokenTree.java

Added: trunk/components-core/src/main/java/org/dllearner/algorithms/isle/index/TokenTree.java
===================================================================
--- trunk/components-core/src/main/java/org/dllearner/algorithms/isle/index/TokenTree.java	                        (rev 0)
+++ trunk/components-core/src/main/java/org/dllearner/algorithms/isle/index/TokenTree.java	2013-12-02 12:51:30 UTC (rev 4177)
@@ -0,0 +1,111 @@
+package org.dllearner.algorithms.isle.index;
+
+import org.dllearner.core.owl.Entity;
+
+import java.util.*;
+
+/**
+ * Tree for finding longest matching Token sequence
+ *
+ * @author Daniel Fleischhacker
+ */
+public class TokenTree {
+    private HashMap<Token, TokenTree> children;
+    private Set<Entity> entities;
+
+    public TokenTree() {
+        this.children = new HashMap<>();
+        this.entities = new HashSet<>();
+    }
+
+    /**
+     * Adds all given entities to the end of the path resulting from the given tokens.
+     *
+     * @param tokens   tokens to locate insertion point for entities
+     * @param entities entities to add
+     */
+    public void add(List<Token> tokens, Set<Entity> entities) {
+        TokenTree curNode = this;
+        for (Token t : tokens) {
+            TokenTree nextNode = curNode.children.get(t);
+            if (nextNode == null) {
+                nextNode = new TokenTree();
+                curNode.children.put(t, nextNode);
+            }
+            curNode = nextNode;
+        }
+        curNode.entities.addAll(entities);
+    }
+
+    /**
+     * Adds the given entity to the tree.
+     *
+     * @param tokens tokens to locate insertion point for entities
+     * @param entity entity to add
+     */
+    public void add(List<Token> tokens, Entity entity) {
+        add(tokens, Collections.singleton(entity));
+    }
+
+    /**
+     * Returns the set of entities located by the given list of tokens.
+     *
+     * @param tokens tokens to locate the information to get
+     * @return located set of entities or null if token sequence not contained in tree
+     */
+    public Set<Entity> get(List<Token> tokens) {
+        TokenTree curNode = this;
+        for (Token t : tokens) {
+            TokenTree nextNode = curNode.children.get(t);
+            if (nextNode == null) {
+                return null;
+            }
+            curNode = nextNode;
+        }
+        return curNode.entities;
+    }
+
+    /**
+     * Returns the list of tokens which are the longest match with entities assigned in this tree.
+     *
+     * @param tokens list of tokens to check for longest match
+     * @return list of tokens being the longest match, sublist of {@code tokens} anchored at the first token
+     */
+    public List<Token> getLongestMatch(List<Token> tokens) {
+        List<Token> fallbackTokenList = new ArrayList<>();
+        TokenTree curNode = this;
+
+        for (Token t : tokens) {
+            TokenTree nextNode = curNode.children.get(t);
+            if (nextNode == null) {
+                return fallbackTokenList;
+            }
+            curNode = nextNode;
+            fallbackTokenList.add(t);
+        }
+        return fallbackTokenList;
+    }
+
+    /**
+     * Returns the set of entities assigned to the longest matching token subsequence of the given token sequence.
+     * @param tokens    token sequence to search for longest match
+     * @return set of entities assigned to the longest matching token subsequence of the given token sequence
+     */
+    public Set<Entity> getEntitiesForLongestMatch(List<Token> tokens) {
+        TokenTree fallback = this.entities.isEmpty() ? null : this;
+        TokenTree curNode = this;
+
+        for (Token t : tokens) {
+            TokenTree nextNode = curNode.children.get(t);
+            if (nextNode == null) {
+                return fallback == null ? null : fallback.entities;
+            }
+            curNode = nextNode;
+            if (!curNode.entities.isEmpty()) {
+                fallback = curNode;
+            }
+        }
+
+        return fallback.entities;
+    }
+}

This was sent by the SourceForge.net collaborative development platform, the world's largest Open Source development site.