2 files changed, 43 insertions, 0 deletions
diff --git a/src/runtime/java/org/grammaticalframework/pgf/Concr.java b/src/runtime/java/org/grammaticalframework/pgf/Concr.java
index af814b4a9..4f082eac8 100644
--- a/src/runtime/java/org/grammaticalframework/pgf/Concr.java
+++ b/src/runtime/java/org/grammaticalframework/pgf/Concr.java
@@ -39,6 +39,10 @@ public class Concr {
 		return new Completer(this, startCat, s, prefix);
 	}
 
+	public Iterable<ExprProb> lookupSentence(String startCat, String s) {
+		return new SentenceExtractor(this, startCat, s);
+	}
+
 	/** Computes the linearization of the abstract expression. */
 	public native String linearize(Expr expr);
 
diff --git a/src/runtime/java/org/grammaticalframework/pgf/SentenceExtractor.java b/src/runtime/java/org/grammaticalframework/pgf/SentenceExtractor.java
new file mode 100644
index 000000000..28aa12682
--- /dev/null
+++ b/src/runtime/java/org/grammaticalframework/pgf/SentenceExtractor.java
@@ -0,0 +1,39 @@
+package org.grammaticalframework.pgf;
+
+import java.util.*;
+
+class SentenceExtractor implements Iterable<ExprProb> {
+	private Concr concr;
+	private String s;
+	private String startCat;
+	private double heuristics;
+	private Map<String,LiteralCallback> callbacks;
+	private ExprIterator iter;
+
+	public SentenceExtractor(Concr concr, String startCat, String s) {
+		this.concr    = concr;
+		this.startCat = startCat;
+		this.s        = s;
+		this.iter     = doExtract();
+	}
+
+	public Iterator<ExprProb> iterator() {
+		if (iter == null) {
+			// If someone has asked for a second iterator over
+			// the same parse results then we have to parse again.
+			return doExtract();
+		} else {
+			ExprIterator tmp_iter = iter;
+			iter = null;
+			return tmp_iter;
+		}
+	}
+
+	private ExprIterator doExtract()
+	{
+		Pool pool = new Pool();
+		return lookupSentence(concr, startCat, s, pool);
+	}
+
+	static native ExprIterator lookupSentence(Concr concr, String startCat, String s, Pool pool);
+}