1 files changed, 82 insertions, 0 deletions
diff --git a/src/de/lmu/ifi/dbs/elki/utilities/pairs/FCPair.java b/src/de/lmu/ifi/dbs/elki/utilities/pairs/FCPair.java
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+++ b/src/de/lmu/ifi/dbs/elki/utilities/pairs/FCPair.java
@@ -0,0 +1,82 @@
+package de.lmu.ifi.dbs.elki.utilities.pairs;
+/*
+This file is part of ELKI:
+Environment for Developing KDD-Applications Supported by Index-Structures
+
+Copyright (C) 2011
+Ludwig-Maximilians-Universität München
+Lehr- und Forschungseinheit für Datenbanksysteme
+ELKI Development Team
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program 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 Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+import de.lmu.ifi.dbs.elki.utilities.ClassGenericsUtil;
+
+/**
+ * Pair that can <em>only</em> be compared by it's first component.
+ * 
+ * @author Erich Schubert
+ * 
+ * @param <FIRST> first type (comparable)
+ * @param <SECOND> second type
+ */
+public class FCPair<FIRST extends Comparable<? super FIRST>, SECOND> extends Pair<FIRST, SECOND> implements Comparable<FCPair<FIRST, SECOND>> {
+  /**
+   * Initialize pair
+   * 
+   * @param first first parameter
+   * @param second second parameter
+   */
+  public FCPair(FIRST first, SECOND second) {
+    super(first, second);
+  }
+
+  /**
+   * Generic derived compare function.
+   * 
+   * @param other Object to compare to
+   * @return comparison result
+   */
+  @Override
+  public int compareTo(FCPair<FIRST, SECOND> other) {
+    // try comparing by first
+    if(this.first != null) {
+      if(other.first == null) {
+        return -1;
+      }
+      int delta1 = this.first.compareTo(other.first);
+      if(delta1 != 0) {
+        return delta1;
+      }
+    }
+    else if(other.first != null) {
+      return +1;
+    }
+    return 0;
+  }
+
+  /**
+   * Array constructor for generics
+   * 
+   * @param <F> First type
+   * @param <S> Second type
+   * @param size Size of array to be constructed
+   * @return New array of requested size
+   */
+  public static final <F extends Comparable<? super F>, S> FCPair<F, S>[] newArray(int size) {
+    Class<FCPair<F,S>> paircls = ClassGenericsUtil.uglyCastIntoSubclass(FCPair.class);    
+    return ClassGenericsUtil.newArrayOfNull(size, paircls);
+  }
+}
+\ No newline at end of file