From 1f60bda44172f1dedaf30785c88163ba6c36a0b9 Mon Sep 17 00:00:00 2001
From: Kristóf Marussy <kris7topher@gmail.com>
Date: Sat, 18 May 2019 14:25:00 -0400
Subject: Interval hull aggregation operator

---
 .../interval/IntervalHullAggregatorOperator.xtend  | 87 ++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 Solvers/VIATRA-Solver/hu.bme.mit.inf.dslreasoner.viatrasolver.logic2viatra/src/hu/bme/mit/inf/dslreasoner/viatrasolver/logic2viatra/interval/IntervalHullAggregatorOperator.xtend

(limited to 'Solvers/VIATRA-Solver/hu.bme.mit.inf.dslreasoner.viatrasolver.logic2viatra/src/hu/bme/mit/inf/dslreasoner/viatrasolver/logic2viatra/interval/IntervalHullAggregatorOperator.xtend')

diff --git a/Solvers/VIATRA-Solver/hu.bme.mit.inf.dslreasoner.viatrasolver.logic2viatra/src/hu/bme/mit/inf/dslreasoner/viatrasolver/logic2viatra/interval/IntervalHullAggregatorOperator.xtend b/Solvers/VIATRA-Solver/hu.bme.mit.inf.dslreasoner.viatrasolver.logic2viatra/src/hu/bme/mit/inf/dslreasoner/viatrasolver/logic2viatra/interval/IntervalHullAggregatorOperator.xtend
new file mode 100644
index 00000000..ce48eca1
--- /dev/null
+++ b/Solvers/VIATRA-Solver/hu.bme.mit.inf.dslreasoner.viatrasolver.logic2viatra/src/hu/bme/mit/inf/dslreasoner/viatrasolver/logic2viatra/interval/IntervalHullAggregatorOperator.xtend
@@ -0,0 +1,87 @@
+package hu.bme.mit.inf.dslreasoner.viatrasolver.logic2viatra.interval
+
+import java.math.BigDecimal
+import java.math.MathContext
+import java.util.SortedMap
+import java.util.TreeMap
+import java.util.stream.Stream
+import org.eclipse.viatra.query.runtime.matchers.psystem.aggregations.IMultisetAggregationOperator
+
+abstract class IntervalHullAggregatorOperator<T extends Comparable<T>> implements IMultisetAggregationOperator<T, SortedMap<T, Integer>, Interval> {
+	protected new() {
+	}
+	
+	override getName() {
+		"intervalHull"
+	}
+
+	override getShortDescription() {
+		"Calculates the interval hull of a set of numbers"
+	}
+
+	override createNeutral() {
+		new TreeMap
+	}
+
+	override getAggregate(SortedMap<T, Integer> result) {
+		if (result.neutral) {
+			Interval.EMPTY
+		} else {
+			toInterval(result.firstKey, result.lastKey)
+		}
+	}
+	
+	protected abstract def BigDecimal toBigDecimal(T value, MathContext mc)
+	
+	private def toInterval(T min, T max) {
+		Interval.of(min.toBigDecimal(Interval.ROUND_DOWN), max.toBigDecimal(Interval.ROUND_UP))
+	}
+
+	override isNeutral(SortedMap<T, Integer> result) {
+		result.empty
+	}
+
+	override update(SortedMap<T, Integer> oldResult, T updateValue, boolean isInsertion) {
+		if (isInsertion) {
+			oldResult.compute(updateValue) [ key, value |
+				if (value === null) {
+					1
+				} else if (value > 0) {
+					value + 1
+				} else {
+					throw new IllegalStateException("Invalid count: " + value)
+				}
+			]
+		} else {
+			oldResult.compute(updateValue) [ key, value |
+				if (value === 1) {
+					null
+				} else if (value > 1) {
+					value - 1
+				} else {
+					throw new IllegalStateException("Invalid count: " + value)
+				}
+			]
+		}
+		oldResult
+	}
+
+	override aggregateStream(Stream<T> stream) {
+		val iterator = stream.iterator
+		if (!iterator.hasNext) {
+			return Interval.EMPTY
+		}
+		var min = iterator.next
+		var max = min
+		while (iterator.hasNext) {
+			val element = iterator.next
+			if (element.compareTo(min) < 0) {
+				min = element
+			}
+			if (element.compareTo(max) > 0) {
+				max = element
+			}
+		}
+		toInterval(min, max)
+	}
+}
-- 
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