1 files changed, 30 insertions, 0 deletions

diff --git a/src/uk/ac/ox/cs/pagoda/query/GapTupleIterator.java b/src/uk/ac/ox/cs/pagoda/query/GapTupleIterator.java
new file mode 100644
index 0000000..58303bb
--- /dev/null
+++ b/src/uk/ac/ox/cs/pagoda/query/GapTupleIterator.java
@@ -0,0 +1,30 @@
+package uk.ac.ox.cs.pagoda.query;
+
+import java.util.Iterator;
+
+import uk.ac.ox.cs.JRDFox.JRDFStoreException;
+import uk.ac.ox.cs.JRDFox.store.DataStore;
+
+public abstract class GapTupleIterator<T> implements Iterator<T> {
+        
+        public static final String gapPredicateSuffix = "_AUXg"; 
+        
+        public static final String getGapPredicate(String predicateIRI) {
+                if (predicateIRI.startsWith("<"))
+                        return predicateIRI.replace(">", gapPredicateSuffix + ">"); 
+                return predicateIRI + gapPredicateSuffix;
+        }
+        
+        public void compile(String programText) throws JRDFStoreException {}
+        
+        public abstract boolean isValid();
+        
+        public abstract void save(String file); 
+        
+        public abstract void addBackTo() throws JRDFStoreException;
+        
+        public abstract void addTo(DataStore store) throws JRDFStoreException;
+        
+        public abstract void clear();
+
+}