Implementing a new numeric comparator to work with roulette wheel selector. #30

src/core/de.evoal.core.main/src/main/java/de/evoal/core/main/comparator/NumericOptimisationComparator.java

+package de.evoal.core.main.comparator;
+
+import de.evoal.core.api.optimisation.OptimisationValue;
+import de.evoal.core.api.optimisation.OptimisationValueComparator;
+import de.evoal.languages.model.el.DoubleLiteral;
+import de.evoal.languages.model.instance.Array;
+import de.evoal.languages.model.instance.Instance;
+import de.evoal.languages.model.instance.LiteralValue;
+
+import javax.enterprise.context.Dependent;
+import javax.inject.Named;
+
+@Dependent
+@Named("numeric-comparator")
+public class NumericOptimisationComparator implements OptimisationValueComparator {
+    @Override
+    public OptimisationValue toValue(final double[] fitnessValues) {
+        return NumericOptimisationValue.of(fitnessValues);
+    }
+
+    @Override
+    public OptimisationValueComparator init(final Instance config) {
+        return this;
+    }
+}

src/core/de.evoal.core.main/src/main/java/de/evoal/core/main/comparator/NumericOptimisationValue.java

+package de.evoal.core.main.comparator;
+
+import de.evoal.core.api.optimisation.OptimisationValue;
+import de.evoal.core.api.utils.Requirements;
+import lombok.Getter;
+import lombok.NonNull;
+
+import java.util.Arrays;
+
+public class NumericOptimisationValue extends Number implements OptimisationValue {
+    @Getter
+    private final Number fitnessValue;
+    private NumericOptimisationValue(final @NonNull Number[] fitnessValues) {
+        Requirements.requireEqual(fitnessValues.length, 1);
+
+        this.fitnessValue = fitnessValues[0];
+    }
+
+    public static OptimisationValue of(final double [] fitnessValues) {
+        return new NumericOptimisationValue(
+                Arrays.stream(fitnessValues)
+                      .mapToObj(Double::valueOf)
+                      .toArray(s -> new Number [s]));
+    }
+
+    @Override
+    public int compareTo(final OptimisationValue other) {
+        if(!(other instanceof NumericOptimisationValue)) {
+            throw new IllegalArgumentException("Only allowed to compare NumericOptimisationValue");
+        }
+
+        return Double.compare(this.fitnessValue.doubleValue(), ((NumericOptimisationValue) other).fitnessValue.doubleValue());
+    }
+
+    @Override
+    public String toString() {
+    	return "NumericOptimisationValue [" + fitnessValue + "]";
+    }
+
+    @Override
+    public Object[] toStatistics() {
+        return new Object [] {fitnessValue};
+    }
+
+    @Override
+    public int intValue() {
+        return fitnessValue.intValue();
+    }
+
+    @Override
+    public long longValue() {
+        return fitnessValue.longValue();
+    }
+
+    @Override
+    public float floatValue() {
+        return floatValue();
+    }
+
+    @Override
+    public double doubleValue() {
+        return fitnessValue.doubleValue();
+    }
+}