Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.utils.datastructures / src / org / simantics / utils / datastructures / Pair.java

diff --git a/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/Pair.java b/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/Pair.java
new file mode 100644 (file)
index 0000000..35d2dee
--- /dev/null
+++ b/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/Pair.java
@@ -0,0 +1,73 @@
+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ *     VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.utils.datastructures;\r
+\r
+\r
+/**\r
+ * A generic Pair (2-tuple) structure for containing two object instances of\r
+ * chosen types.\r
+ * \r
+ * @param <T1> type of first element\r
+ * @param <T2> type of second element\r
+ */\r
+public final class Pair<T1, T2> implements Comparable<Pair<T1, T2>> {\r
+    public final T1 first;\r
+    public final T2 second;\r
+    private final int hash;\r
+\r
+    public static <T1, T2> Pair<T1, T2> make(T1 t1, T2 t2) {\r
+        return new Pair<T1, T2>(t1, t2);\r
+    }\r
+\r
+    public Pair(T1 first, T2 second) {\r
+        //assert(first != null);\r
+        //assert(second != null);\r
+        \r
+        this.first = first;\r
+        this.second = second;\r
+        this.hash = makeHash();\r
+    }\r
+    \r
+    @Override\r
+    public boolean equals(Object obj) {\r
+        if (obj == null)\r
+            return false;\r
+        if (!(obj.getClass().equals(this.getClass())))\r
+            return false;\r
+        Pair<?, ?> other = (Pair<?, ?>) obj;\r
+        if (other.first != first && (other.first == null || !other.first.equals(first)))\r
+            return false;\r
+        if (other.second != second && (other.second == null || !other.second.equals(second)))\r
+            return false;\r
+        return true;\r
+    }\r
+    \r
+    @Override\r
+    public int hashCode() {\r
+        return hash;\r
+    }\r
+    \r
+    @Override\r
+    public String toString() {\r
+        return "<"+first+", "+second+">";\r
+    }\r
+    \r
+    private int makeHash() {\r
+        return (first == null ? 0 : first.hashCode()) + (second == null ? 0 : second.hashCode())*31;\r
+    }\r
+\r
+       @Override\r
+       public int compareTo(Pair<T1, T2> arg0) {\r
+               return hash - arg0.hash;\r
+       }\r
+       \r
+}\r