1 files changed, 32 insertions, 4 deletions
diff --git a/src/runtime/java/org/grammaticalframework/sg/SG.java b/src/runtime/java/org/grammaticalframework/sg/SG.java
index 631b38ff7..278dd8117 100644
--- a/src/runtime/java/org/grammaticalframework/sg/SG.java
+++ b/src/runtime/java/org/grammaticalframework/sg/SG.java
@@ -1,12 +1,40 @@
 package org.grammaticalframework.sg;
 
 import java.io.Closeable;
-import org.grammaticalframework.pgf.Expr;
+import org.grammaticalframework.pgf.*;
 
 public class SG implements Closeable {
-	public static native SG openSG(String path);
-	public native void close();
-	public native TripleResult queryTriple(Expr subj, Expr pred, Expr obj);
+	/** Opens a new database file */
+	public static native SG openSG(String path) throws SGError;
+	
+	/** Closes an already opened database */
+	public native void close() throws SGError;
+
+	/** Reads a triple in the format <expr,expr,expr> and returns it as an array */
+	public static native Expr[] readTriple(String s) throws PGFError;
+
+	/** Simple triple queries. Each of the arguments subj, pred and obj
+	 * could be null. In that case the argument is interpreted as a wild card.
+	 * If one of the arguments is not null then only triples with matching values
+	 * will be retrieved.  
+	 * 
+	 * @return An iterator over the matching triples
+	 */
+	public native TripleResult queryTriple(Expr subj, Expr pred, Expr obj) throws SGError;
+
+	/** Start a new transaction */
+	public native void beginTrans() throws SGError;
+	
+	/** Commits the transaction */
+	public native void commit() throws SGError;
+	
+	/** Rollbacks all changes made in the current transaction */
+	public native void rollback() throws SGError;
+
+	/** Inserts a new triple.
+	 * @return an unique id that identifies this triple in the database
+	 */
+	public native long insertTriple(Expr subj, Expr pred, Expr obj) throws SGError;
 
 	//////////////////////////////////////////////////////////////////
 	// private stuff