1 files changed, 126 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/classpath/Pair.java b/libjava/classpath/gnu/classpath/Pair.java
new file mode 100644
index 00000000000..57af37a7464
--- /dev/null
+++ b/libjava/classpath/gnu/classpath/Pair.java
@@ -0,0 +1,126 @@
+/* Pair.java -- A heterogenous pair of objects.
+   Copyright (C) 2006
+   Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package gnu.classpath;
+
+/**
+ * A container for a pair of heterogenous objects.
+ *
+ * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
+ */
+public class Pair<A,B>
+{
+
+  /**
+   * The left-hand side of the pair.
+   */
+  private A left;
+
+  /**
+   * The right-hand side of the pair.
+   */
+  private B right;
+
+  /**
+   * Constructs a new pair using the given left and
+   * right values.
+   *
+   * @param left the left-hand side of the pair.
+   * @param right the right-hand side of the pair.
+   */
+  public Pair(A left, B right)
+  {
+    this.left = left;
+    this.right = right;
+  }
+
+  /**
+   * Returns the left-hand side of the pair.
+   *
+   * @return the left-hand value.
+   */
+  public A getLeft()
+  {
+    return left;
+  }
+
+  /**
+   * Returns the right-hand side of the pair.
+   *
+   * @return the right-hand value.
+   */
+  public B getRight()
+  {
+    return right;
+  }
+
+  /**
+   * Returns true if the specified object is also a
+   * pair with equivalent left and right values.
+   *
+   * @param obj the object to compare.
+   * @return true if the two are equal.
+   */
+  public boolean equals(Object obj)
+  {
+    if (obj instanceof Pair)
+      {
+	Pair<A,B> p = (Pair<A,B>) obj;
+	A lp = p.getLeft();
+	B rp = p.getRight(); 
+	return (lp == null ? left == null : lp.equals(left)) &&
+	  (rp == null ? right == null : rp.equals(right));
+      }
+    return false;
+  }
+
+  /**
+   * Returns a hashcode for the pair, created by the
+   * summation of the hashcodes of the left and right
+   * hand values.
+   *
+   * @return a hashcode for the pair.
+   */
+  public int hashCode()
+  {
+    return (left == null ? 0 : left.hashCode())
+      + (right == null ? 0 : right.hashCode());
+  }
+
+}