13 files changed, 788 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/AverageAccumulator.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/AverageAccumulator.java
new file mode 100644
index 00000000..2c09ede1
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/AverageAccumulator.java
@@ -0,0 +1,24 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2018, 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;
+
+/**
+ * @since 2.0
+ */
+class AverageAccumulator<Domain> {
+    Domain value;
+    long count;
+
+    public AverageAccumulator(Domain value, long count) {
+        super();
+        this.value = value;
+        this.count = count;
+    }
+    
+}
\ No newline at end of file
diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/DoubleAverageOperator.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/DoubleAverageOperator.java
new file mode 100644
index 00000000..e8a26afd
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/DoubleAverageOperator.java
@@ -0,0 +1,82 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2018, 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 java.util.OptionalDouble;
+import java.util.stream.Stream;
+
+import tools.refinery.viatra.runtime.matchers.psystem.aggregations.IMultisetAggregationOperator;
+
+/**
+ * @author Zoltan Ujhelyi
+ * @since 2.0
+ */
+public class DoubleAverageOperator implements IMultisetAggregationOperator<Double, AverageAccumulator<Double>, Double> {
+
+    public static final DoubleAverageOperator INSTANCE = new DoubleAverageOperator();
+    
+    private DoubleAverageOperator() {
+        // Singleton, do not call.
+    }
+    
+    @Override
+    public String getShortDescription() {
+        return "avg<Integer> incrementally computes the average of java.lang.Integer values";
+    }
+
+    @Override
+    public String getName() {
+        return "avg<Integer>";
+    }
+
+    @Override
+    public AverageAccumulator<Double> createNeutral() {
+        return new AverageAccumulator<Double>(0d, 0l);
+    }
+
+    @Override
+    public boolean isNeutral(AverageAccumulator<Double> result) {
+        return result.count == 0l;
+    }
+
+    @Override
+    public AverageAccumulator<Double> update(AverageAccumulator<Double> oldResult, Double updateValue,
+            boolean isInsertion) {
+        if (isInsertion) {
+            oldResult.value += updateValue;
+            oldResult.count++;
+        } else {
+            oldResult.value -= updateValue;
+            oldResult.count--;
+        }
+        return oldResult;
+    }
+
+    @Override
+    public Double getAggregate(AverageAccumulator<Double> result) {
+        return (result.count == 0)
+                ? null
+                : result.value/result.count;
+    }
+
+    @Override
+    public Double aggregateStream(Stream<Double> stream) {
+        final OptionalDouble averageOpt = stream.mapToDouble(Double::doubleValue).average();
+        return averageOpt.isPresent() ? averageOpt.getAsDouble() : null;
+    }
+    
+    /**
+     * @since 2.4
+     */
+    @Override
+    public AverageAccumulator<Double> clone(AverageAccumulator<Double> original) {
+        return new AverageAccumulator<Double>(original.value, original.count);
+    }
+    
+}
\ No newline at end of file
diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/DoubleSumOperator.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/DoubleSumOperator.java
new file mode 100644
index 00000000..744b0cd1
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/DoubleSumOperator.java
@@ -0,0 +1,62 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2016, Gabor Bergmann, IncQueryLabs 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 java.util.stream.Stream;
+
+import tools.refinery.viatra.runtime.matchers.psystem.aggregations.AbstractMemorylessAggregationOperator;
+
+/**
+ * Incrementally computes the sum of java.lang.Double values
+ * @author Gabor Bergmann
+ * @since 1.4
+ */
+public class DoubleSumOperator extends AbstractMemorylessAggregationOperator<Double, Double> {
+    public static final DoubleSumOperator INSTANCE = new DoubleSumOperator();
+    
+    private DoubleSumOperator() {
+        // Singleton, do not call.
+    }
+
+    @Override
+    public String getShortDescription() {
+        return "sum<Double> incrementally computes the sum of java.lang.Double values";
+    }
+    @Override
+    public String getName() {
+        return "sum<Double>";
+    }
+    
+    @Override
+    public Double createNeutral() {
+        return 0d;
+    }
+
+    @Override
+    public boolean isNeutral(Double result) {
+        return createNeutral().equals(result);
+    }
+
+    @Override
+    public Double update(Double oldResult, Double updateValue, boolean isInsertion) {
+        return isInsertion ? 
+                oldResult + updateValue : 
+                oldResult - updateValue;
+    }
+
+    /**
+     * @since 2.0
+     */
+    @Override
+    public Double aggregateStream(Stream<Double> stream) {
+        return stream.mapToDouble(Double::doubleValue).sum();
+    }
+    
+    
+}
diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/ExtremumOperator.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/ExtremumOperator.java
new file mode 100644
index 00000000..ee4ceeb8
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/ExtremumOperator.java
@@ -0,0 +1,135 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2016, Gabor Bergmann, IncQueryLabs 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 java.util.Comparator;
+import java.util.SortedMap;
+import java.util.TreeMap;
+import java.util.stream.Stream;
+
+import tools.refinery.viatra.runtime.matchers.psystem.aggregations.IMultisetAggregationOperator;
+
+/**
+ * Incrementally computes the minimum or maximum of java.lang.Comparable values, using the default comparison
+ * 
+ * @author Gabor Bergmann
+ * @since 1.4
+ */
+public class ExtremumOperator<T extends Comparable<T>>
+        implements IMultisetAggregationOperator<T, SortedMap<T, Integer>, T> {
+    
+    public enum Extreme {
+        MIN, MAX;
+        
+        /**
+         * @since 2.0
+         */
+        public <T> T pickFrom(SortedMap<T, Integer> nonEmptyMultiSet) {
+            switch(this) {
+            case MIN: 
+                return nonEmptyMultiSet.firstKey(); 
+            case MAX:
+                return nonEmptyMultiSet.lastKey();
+            default:
+                return null;
+            }
+        }
+    }
+
+    private static final ExtremumOperator MIN_OP = new ExtremumOperator<>(Extreme.MIN);
+    private static final ExtremumOperator MAX_OP = new ExtremumOperator<>(Extreme.MAX);
+
+    public static <T extends Comparable<T>> ExtremumOperator<T> getMin() {
+        return MIN_OP;
+    }
+    public static <T extends Comparable<T>> ExtremumOperator<T> getMax() {
+        return MAX_OP;
+    }
+    
+    Extreme extreme;
+    private ExtremumOperator(Extreme extreme) {
+        super();
+        this.extreme = extreme;
+    }
+
+    @Override
+    public String getShortDescription() {
+        String opName = getName();
+        return String.format(
+                "%s incrementally computes the %simum of java.lang.Comparable values, using the default comparison",
+                opName, opName);
+    }
+
+    @Override
+    public String getName() {
+        return extreme.name().toLowerCase();
+    }
+
+    /**
+     * @since 2.0
+     */
+    @Override
+    public SortedMap<T, Integer> createNeutral() {
+        return new TreeMap<>();
+    }
+
+    /**
+     * @since 2.0
+     */
+    @Override
+    public boolean isNeutral(SortedMap<T, Integer> result) {
+        return result.isEmpty();
+    }
+
+    /**
+     * @since 2.0
+     */
+    @Override
+    public SortedMap<T, Integer> update(SortedMap<T, Integer> oldResult, T updateValue, boolean isInsertion) {
+        oldResult.compute(updateValue, (value, c) -> {
+            int count = (c == null) ? 0 : c;
+            int result = (isInsertion) ? count+1 : count-1;  
+            return (result == 0) ? null : result;
+        });
+        return oldResult;
+    }
+
+    /**
+     * @since 2.0
+     */
+    @Override
+    public T getAggregate(SortedMap<T, Integer> result) {
+        return result.isEmpty() ? null : 
+            extreme.pickFrom(result);
+    }
+    
+    /**
+     * @since 2.0
+     */
+    @Override
+    public T aggregateStream(Stream<T> stream) {
+        switch (extreme) {
+        case MIN:
+            return stream.min(Comparator.naturalOrder()).orElse(null);
+        case MAX:
+            return stream.max(Comparator.naturalOrder()).orElse(null);
+        default:
+            return null;
+        }
+    }
+    
+    /**
+     * @since 2.4
+     */
+    @Override
+    public SortedMap<T, Integer> clone(SortedMap<T, Integer> original) {
+        return new TreeMap<T, Integer>(original);
+    }
+    
+}
diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/IntegerAverageOperator.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/IntegerAverageOperator.java
new file mode 100644
index 00000000..bf422476
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/IntegerAverageOperator.java
@@ -0,0 +1,82 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2018, 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 java.util.OptionalDouble;
+import java.util.stream.Stream;
+
+import tools.refinery.viatra.runtime.matchers.psystem.aggregations.IMultisetAggregationOperator;
+
+/**
+ * @author Zoltan Ujhelyi
+ * @since 2.0
+ */
+public class IntegerAverageOperator implements IMultisetAggregationOperator<Integer, AverageAccumulator<Integer>, Double> {
+
+    public static final IntegerAverageOperator INSTANCE = new IntegerAverageOperator();
+    
+    private IntegerAverageOperator() {
+        // Singleton, do not call.
+    }
+    
+    @Override
+    public String getShortDescription() {
+        return "avg<Integer> incrementally computes the average of java.lang.Integer values";
+    }
+
+    @Override
+    public String getName() {
+        return "avg<Integer>";
+    }
+
+    @Override
+    public AverageAccumulator<Integer> createNeutral() {
+        return new AverageAccumulator<Integer>(0, 0l);
+    }
+
+    @Override
+    public boolean isNeutral(AverageAccumulator<Integer> result) {
+        return result.count == 0l;
+    }
+
+    @Override
+    public AverageAccumulator<Integer> update(AverageAccumulator<Integer> oldResult, Integer updateValue,
+            boolean isInsertion) {
+        if (isInsertion) {
+            oldResult.value += updateValue;
+            oldResult.count++;
+        } else {
+            oldResult.value -= updateValue;
+            oldResult.count--;
+        }
+        return oldResult;
+    }
+
+    @Override
+    public Double getAggregate(AverageAccumulator<Integer> result) {
+        return (result.count == 0)
+                ? null
+                : ((double)result.value)/result.count;
+    }
+
+    @Override
+    public Double aggregateStream(Stream<Integer> stream) {
+        final OptionalDouble averageOpt = stream.mapToInt(Integer::intValue).average();
+        return averageOpt.isPresent() ? averageOpt.getAsDouble() : null;
+    }
+    
+    /**
+     * @since 2.4
+     */
+    @Override
+    public AverageAccumulator<Integer> clone(AverageAccumulator<Integer> original) {
+        return new AverageAccumulator<Integer>(original.value, original.count);
+    }
+    
+}
\ No newline at end of file
diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/IntegerSumOperator.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/IntegerSumOperator.java
new file mode 100644
index 00000000..18584256
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/IntegerSumOperator.java
@@ -0,0 +1,61 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2016, Gabor Bergmann, IncQueryLabs 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 java.util.stream.Stream;
+
+import tools.refinery.viatra.runtime.matchers.psystem.aggregations.AbstractMemorylessAggregationOperator;
+
+/**
+ * Incrementally computes the sum of java.lang.Integer values
+ * @author Gabor Bergmann
+ * @since 1.4
+ */
+public class IntegerSumOperator extends AbstractMemorylessAggregationOperator<Integer, Integer> {
+    public static final IntegerSumOperator INSTANCE = new IntegerSumOperator();
+    
+    private IntegerSumOperator() {
+        // Singleton, do not call.
+    }
+
+    @Override
+    public String getShortDescription() {
+        return "sum<Integer> incrementally computes the sum of java.lang.Integer values";
+    }
+    @Override
+    public String getName() {
+        return "sum<Integer>";
+    }
+    
+    @Override
+    public Integer createNeutral() {
+        return 0;
+    }
+
+    @Override
+    public boolean isNeutral(Integer result) {
+        return createNeutral().equals(result);
+    }
+
+    @Override
+    public Integer update(Integer oldResult, Integer updateValue, boolean isInsertion) {
+        return isInsertion ? 
+                oldResult + updateValue : 
+                oldResult - updateValue;
+    }
+
+    /**
+     * @since 2.0
+     */
+    @Override
+    public Integer aggregateStream(Stream<Integer> stream) {
+        return stream.mapToInt(Integer::intValue).sum();
+    }
+
+}
diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/LongAverageOperator.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/LongAverageOperator.java
new file mode 100644
index 00000000..d56c9507
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/LongAverageOperator.java
@@ -0,0 +1,82 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2018, 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 java.util.OptionalDouble;
+import java.util.stream.Stream;
+
+import tools.refinery.viatra.runtime.matchers.psystem.aggregations.IMultisetAggregationOperator;
+
+/**
+ * @author Zoltan Ujhelyi
+ * @since 2.0
+ */
+public class LongAverageOperator implements IMultisetAggregationOperator<Long, AverageAccumulator<Long>, Double> {
+
+    public static final LongAverageOperator INSTANCE = new LongAverageOperator();
+    
+    private LongAverageOperator() {
+        // Singleton, do not call.
+    }
+    
+    @Override
+    public String getShortDescription() {
+        return "avg<Integer> incrementally computes the average of java.lang.Integer values";
+    }
+
+    @Override
+    public String getName() {
+        return "avg<Integer>";
+    }
+
+    @Override
+    public AverageAccumulator<Long> createNeutral() {
+        return new AverageAccumulator<Long>(0l, 0l);
+    }
+
+    @Override
+    public boolean isNeutral(AverageAccumulator<Long> result) {
+        return result.count == 0l;
+    }
+
+    @Override
+    public AverageAccumulator<Long> update(AverageAccumulator<Long> oldResult, Long updateValue,
+            boolean isInsertion) {
+        if (isInsertion) {
+            oldResult.value += updateValue;
+            oldResult.count++;
+        } else {
+            oldResult.value -= updateValue;
+            oldResult.count--;
+        }
+        return oldResult;
+    }
+
+    @Override
+    public Double getAggregate(AverageAccumulator<Long> result) {
+        return (result.count == 0)
+                ? null
+                : ((double)result.value)/result.count;
+    }
+
+    @Override
+    public Double aggregateStream(Stream<Long> stream) {
+        final OptionalDouble averageOpt = stream.mapToLong(Long::longValue).average();
+        return averageOpt.isPresent() ? averageOpt.getAsDouble() : null;
+    }
+    
+    /**
+     * @since 2.4
+     */
+    @Override
+    public AverageAccumulator<Long> clone(AverageAccumulator<Long> original) {
+        return new AverageAccumulator<Long>(original.value, original.count);
+    }
+    
+}
\ No newline at end of file
diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/LongSumOperator.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/LongSumOperator.java
new file mode 100644
index 00000000..29ded090
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/LongSumOperator.java
@@ -0,0 +1,61 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2016, Gabor Bergmann, IncQueryLabs 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 java.util.stream.Stream;
+
+import tools.refinery.viatra.runtime.matchers.psystem.aggregations.AbstractMemorylessAggregationOperator;
+
+/**
+ * Incrementally computes the sum of java.lang.Long values
+ * @author Gabor Bergmann
+ * @since 1.4
+ */
+public class LongSumOperator extends AbstractMemorylessAggregationOperator<Long, Long> {
+    public static final LongSumOperator INSTANCE = new LongSumOperator();
+    
+    private LongSumOperator() {
+        // Singleton, do not call.
+    }
+
+    @Override
+    public String getShortDescription() {
+        return "sum<Long> incrementally computes the sum of java.lang.Long values";
+    }
+    @Override
+    public String getName() {
+        return "sum<Long>";
+    }
+    
+    @Override
+    public Long createNeutral() {
+        return 0L;
+    }
+
+    @Override
+    public boolean isNeutral(Long result) {
+        return createNeutral().equals(result);
+    }
+
+    @Override
+    public Long update(Long oldResult, Long updateValue, boolean isInsertion) {
+        return isInsertion ? 
+                oldResult + updateValue : 
+                oldResult - updateValue;
+    }
+
+    /**
+     * @since 2.0
+     */
+    @Override
+    public Long aggregateStream(Stream<Long> stream) {
+        return stream.mapToLong(Long::longValue).sum();
+    }
+    
+}
diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/avg.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/avg.java
new file mode 100644
index 00000000..c25678aa
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/avg.java
@@ -0,0 +1,39 @@
+/*******************************************************************************
+ * 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;
+
+/**
+ * This aggregator calculates the average of the values of a selected aggregate parameter of a called pattern. The aggregate
+ * parameter is selected with the '#' symbol; the aggregate parameter must not be used outside the aggregator call. The
+ * other parameters of the call might be bound or unbound; bound parameters limit the matches to consider for the
+ * summation.
+ * 
+ * @since 2.0
+ *
+ */
+@AggregatorType(
+        parameterTypes = {Integer.class, Double.class, Long.class},
+        returnTypes = {Double.class, Double.class, Double.class})
+public final class avg implements IAggregatorFactory {
+
+    @Override
+    public BoundAggregator getAggregatorLogic(Class<?> domainClass) {
+        if (Integer.class.equals(domainClass))
+            return new BoundAggregator(IntegerAverageOperator.INSTANCE, Integer.class, Double.class);
+        if (Double.class.equals(domainClass))
+            return new BoundAggregator(DoubleAverageOperator.INSTANCE, Double.class, Double.class);
+        if (Long.class.equals(domainClass))
+            return new BoundAggregator(LongAverageOperator.INSTANCE, Long.class, Double.class);
+        else throw new IllegalArgumentException();
+    }
+}
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();
+    }
+
+
+}
diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/max.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/max.java
new file mode 100644
index 00000000..e0236223
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/max.java
@@ -0,0 +1,44 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2016, Gabor Bergmann, IncQueryLabs 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 java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.Calendar;
+import java.util.Date;
+
+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;
+
+/**
+ * This aggregator calculates the maximum value of a selected aggregate parameter of a called pattern. The aggregate
+ * parameter is selected with the '#' symbol; the aggregate parameter must not be used outside the aggregator call. The
+ * other parameters of the call might be bound or unbound; bound parameters limit the matches to consider for the
+ * minimum calculation.
+ * 
+ * @since 1.4
+ * @author Gabor Bergmann
+ */
+@AggregatorType(
+        // TODO T extends Comparable?
+        parameterTypes = {BigDecimal.class, BigInteger.class, Boolean.class, Byte.class, Calendar.class, Character.class, 
+                Date.class, Double.class, Enum.class, Float.class, Integer.class, Long.class, Short.class, String.class},
+        returnTypes = {BigDecimal.class, BigInteger.class, Boolean.class, Byte.class, Calendar.class, Character.class, 
+                Date.class, Double.class, Enum.class, Float.class, Integer.class, Long.class, Short.class, String.class})
+public final class max implements IAggregatorFactory {
+
+    @Override
+    public BoundAggregator getAggregatorLogic(Class<?> domainClass) {
+        if (Comparable.class.isAssignableFrom(domainClass))
+            return new BoundAggregator(ExtremumOperator.getMax(), domainClass, domainClass);
+        else throw new IllegalArgumentException();
+    }
+
+}
diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/min.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/min.java
new file mode 100644
index 00000000..6408c57b
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/min.java
@@ -0,0 +1,44 @@
+/*******************************************************************************
+ * 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 java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.Calendar;
+import java.util.Date;
+
+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;
+
+/**
+ * This aggregator calculates the minimum value of a selected aggregate parameter of a called pattern. The aggregate
+ * parameter is selected with the '#' symbol; the aggregate parameter must not be used outside the aggregator call. The
+ * other parameters of the call might be bound or unbound; bound parameters limit the matches to consider for the
+ * minimum calculation.
+ * 
+ * @since 1.4
+ *
+ */
+@AggregatorType(
+        // TODO T extends Comparable?
+        parameterTypes = {BigDecimal.class, BigInteger.class, Boolean.class, Byte.class, Calendar.class, Character.class, 
+                Date.class, Double.class, Enum.class, Float.class, Integer.class, Long.class, Short.class, String.class},
+        returnTypes = {BigDecimal.class, BigInteger.class, Boolean.class, Byte.class, Calendar.class, Character.class, 
+                Date.class, Double.class, Enum.class, Float.class, Integer.class, Long.class, Short.class, String.class})
+public final class min implements IAggregatorFactory {
+    
+    @Override
+    public BoundAggregator getAggregatorLogic(Class<?> domainClass) {
+        if (Comparable.class.isAssignableFrom(domainClass))
+            return new BoundAggregator(ExtremumOperator.getMin(), domainClass, domainClass);
+        else throw new IllegalArgumentException();
+    }
+
+}
diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/sum.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/sum.java
new file mode 100644
index 00000000..69ff2e75
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/aggregators/sum.java
@@ -0,0 +1,39 @@
+/*******************************************************************************
+ * 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;
+
+/**
+ * This aggregator calculates the sum of the values of a selected aggregate parameter of a called pattern. The aggregate
+ * parameter is selected with the '#' symbol; the aggregate parameter must not be used outside the aggregator call. The
+ * other parameters of the call might be bound or unbound; bound parameters limit the matches to consider for the
+ * summation.
+ * 
+ * @since 1.4
+ *
+ */
+@AggregatorType(
+        parameterTypes = {Integer.class, Double.class, Long.class},
+        returnTypes = {Integer.class, Double.class, Long.class})
+public final class sum implements IAggregatorFactory {
+
+    @Override
+    public BoundAggregator getAggregatorLogic(Class<?> domainClass) {
+        if (Integer.class.equals(domainClass))
+            return new BoundAggregator(IntegerSumOperator.INSTANCE, Integer.class, Integer.class);
+        if (Double.class.equals(domainClass))
+            return new BoundAggregator(DoubleSumOperator.INSTANCE, Double.class, Double.class);
+        if (Long.class.equals(domainClass))
+            return new BoundAggregator(LongSumOperator.INSTANCE, Long.class, Long.class);
+        else throw new IllegalArgumentException();
+    }
+}