1 files changed, 33 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/count.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/count.java
new file mode 100644
index 00000000..8310a0ce
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/count.java
@@ -0,0 +1,33 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2016, Zoltan Ujhelyi, IncQuery Labs Ltd.
+ * 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.aggregators;
+
+import tools.refinery.viatra.runtime.matchers.psystem.aggregations.AggregatorType;
+import tools.refinery.viatra.runtime.matchers.psystem.aggregations.BoundAggregator;
+import tools.refinery.viatra.runtime.matchers.psystem.aggregations.IAggregatorFactory;
+
+/**
+ * An aggregator to count the number of matches a pattern has. The return of the aggregator is an non-negative integer
+ * number.
+ * 
+ * @since 1.4
+ *
+ */
+@AggregatorType(parameterTypes = {Void.class}, returnTypes = {Integer.class})
+public final class count implements IAggregatorFactory {
+
+    @Override
+    public BoundAggregator getAggregatorLogic(Class<?> domainClass) {
+        if (Void.class.equals(domainClass))
+            return new BoundAggregator(null, Void.class, Integer.class);
+        else throw new IllegalArgumentException();
+    }
+
+
+}