1 files changed, 48 insertions, 0 deletions

diff --git a/Solvers/VIATRA-Solver/hu.bme.mit.inf.dslreasoner.viatrasolver.reasoner/src/hu/bme/mit/inf/dslreasoner/viatrasolver/reasoner/optimization/QueryBasedObjective.xtend b/Solvers/VIATRA-Solver/hu.bme.mit.inf.dslreasoner.viatrasolver.reasoner/src/hu/bme/mit/inf/dslreasoner/viatrasolver/reasoner/optimization/QueryBasedObjective.xtend
new file mode 100644
index 00000000..d355f5be
--- /dev/null
+++ b/Solvers/VIATRA-Solver/hu.bme.mit.inf.dslreasoner.viatrasolver.reasoner/src/hu/bme/mit/inf/dslreasoner/viatrasolver/reasoner/optimization/QueryBasedObjective.xtend
@@ -0,0 +1,48 @@
+package hu.bme.mit.inf.dslreasoner.viatrasolver.reasoner.optimization
+
+import org.eclipse.viatra.dse.base.ThreadContext
+import org.eclipse.viatra.query.runtime.api.IPatternMatch
+import org.eclipse.viatra.query.runtime.api.IQuerySpecification
+import org.eclipse.viatra.query.runtime.api.ViatraQueryMatcher
+
+class QueryBasedObjective extends DirectionalThresholdObjective {
+        val IQuerySpecification<? extends ViatraQueryMatcher<? extends IPatternMatch>> querySpecification
+        ViatraQueryMatcher<? extends IPatternMatch> matcher
+
+        new(IQuerySpecification<? extends ViatraQueryMatcher<? extends IPatternMatch>> querySpecification,
+                ObjectiveKind kind, ObjectiveThreshold threshold, int level) {
+                super(querySpecification.simpleName + " objective", kind, threshold, level)
+                if (querySpecification.parameters.size != 1) {
+                        throw new IllegalArgumentException("Objective query must have a single parameter")
+                }
+                this.querySpecification = querySpecification
+        }
+
+        override createNew() {
+                new QueryBasedObjective(querySpecification, kind, threshold, level)
+        }
+
+        override init(ThreadContext context) {
+                matcher = querySpecification.getMatcher(context.queryEngine)
+        }
+
+        override protected getRawFitness(ThreadContext context) {
+                val iterator = matcher.allMatches.iterator
+                if (!iterator.hasNext) {
+                        return invalidValue
+                }
+                val value = iterator.next.get(0)
+                if (iterator.hasNext) {
+                        throw new IllegalStateException("Multiple matches for objective query")
+                }
+                if (value instanceof Number) {
+                        value.doubleValue
+                } else {
+                        throw new IllegalStateException("Objective value is not an instance of Number")
+                }
+        }
+
+        private def getInvalidValue() {
+                kind.invalidValue
+        }
+}