1 files changed, 69 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/tuple/Tuple.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/tuple/Tuple.java
new file mode 100644
index 00000000..d94f545f
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/tuple/Tuple.java
@@ -0,0 +1,69 @@
+/*******************************************************************************
+ * Copyright (c) 2004-2008 Gabor Bergmann and Daniel Varro
+ * 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.viatra.runtime.matchers.tuple;
+
+/**
+ * Immutable tuple. Obtain instances via utility class {@link Tuples}.
+ * @author Gabor Bergmann
+ * 
+ */
+public abstract class Tuple extends AbstractTuple {
+
+    /**
+     * Caches precalculated hash value
+     */
+    protected int cachedHash;
+
+    /**
+     * Creates a Tuple instance Derivatives should call calcHash()
+     */
+    protected Tuple() {
+        // calcHash();
+    }
+
+    /**
+     * Hash calculation. Overrides should keep semantics.
+     */
+    void calcHash() {
+        cachedHash = doCalcHash();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj instanceof ITuple) {
+            final ITuple other = (ITuple) obj;
+            return cachedHash == other.hashCode() && internalEquals(other);
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        // Calculated by #calcHash
+        return cachedHash;
+    }
+
+    public Tuple replaceAll(Object obsolete, Object replacement) {
+        Object[] oldElements = getElements();
+        Object[] newElements = new Object[oldElements.length];
+        for (int i = 0; i < oldElements.length; ++i) {
+            newElements[i] = obsolete.equals(oldElements[i]) ? replacement : oldElements[i];
+        }
+        return Tuples.flatTupleOf(newElements);
+    }
+
+    @Override
+    public Tuple toImmutable() {
+        return this;
+    }
+
+}