1 files changed, 50 insertions, 0 deletions

diff --git a/subprojects/interpreter/src/main/java/tools/refinery/interpreter/matchers/tuple/VolatileMaskedTuple.java b/subprojects/interpreter/src/main/java/tools/refinery/interpreter/matchers/tuple/VolatileMaskedTuple.java
new file mode 100644
index 00000000..c47a1b89
--- /dev/null
+++ b/subprojects/interpreter/src/main/java/tools/refinery/interpreter/matchers/tuple/VolatileMaskedTuple.java
@@ -0,0 +1,50 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2017, Zoltan Ujhelyi, IncQuery Labs Ltd.
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-v20.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *******************************************************************************/
+package tools.refinery.interpreter.matchers.tuple;
+
+import tools.refinery.interpreter.matchers.util.Preconditions;
+
+/**
+ * This class provides a volatile tuple view with a given mask of a given tuple instance. If the masked tuple changes,
+ * the view updates as well.
+ *
+ * @author Zoltan Ujhelyi
+ * @since 1.7
+ *
+ */
+public class VolatileMaskedTuple extends VolatileTuple {
+
+    protected final TupleMask mask;
+    protected ITuple source;
+
+    public VolatileMaskedTuple(ITuple source, TupleMask mask) {
+        this.source = source;
+        this.mask = mask;
+    }
+
+    public VolatileMaskedTuple(TupleMask mask) {
+        this(null, mask);
+    }
+
+    public void updateTuple(ITuple newSource) {
+        source = newSource;
+    }
+
+    @Override
+    public Object get(int index) {
+        Preconditions.checkState(source != null, "Source tuple is not set.");
+        return mask.getValue(source, index);
+    }
+
+    @Override
+    public int getSize() {
+        return mask.getSize();
+    }
+
+}