1 files changed, 42 insertions, 0 deletions
diff --git a/src/jrummikub/ai/fdsolver/constraint/ComparatorPropagator.java b/src/jrummikub/ai/fdsolver/constraint/ComparatorPropagator.java
new file mode 100644
index 0000000..b3a3089
--- /dev/null
+++ b/src/jrummikub/ai/fdsolver/constraint/ComparatorPropagator.java
@@ -0,0 +1,42 @@
+package jrummikub.ai.fdsolver.constraint;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+
+import jrummikub.ai.fdsolver.Propagator;
+import jrummikub.ai.fdsolver.Var;
+
+public class ComparatorPropagator<T> implements Propagator {
+	private Var<T> x, y;
+	private Comparator<T> comparator;
+	private boolean allowEqual;
+	public ComparatorPropagator(Comparator<T> comparator, boolean allowEqual, Var<T> x, Var<T> y) {
+		this.comparator = comparator;
+		this.allowEqual = allowEqual;
+		this.x = x;
+		this.y = y;
+	}
+
+	@Override
+	public Collection<Var<?>> getWatchedVars() {
+		return Arrays.<Var<?>>asList(y);
+	}
+
+	@Override
+	public void propagate() {
+		T maxY = Collections.max(y.getRange(), comparator);
+		
+		for(Iterator<T> i = x.iterator(); i.hasNext();) {
+			T value = i.next();
+			int comparision = comparator.compare(value, maxY);
+			if (comparision > 0 || comparision == 0 && !allowEqual) {
+				i.remove();
+			}
+		}
+	}
+}