Add array lift for functions and test

Treiblesschorle · ctrueden · commit af212a96150f · 2019-04-18T12:16:31.000-05:00
diff --git a/src/main/java/org/scijava/ops/util/Maps.java b/src/main/java/org/scijava/ops/util/Maps.java
@@ -1,5 +1,6 @@
 package org.scijava.ops.util;
 
+import java.lang.reflect.Array;
 import java.util.Iterator;
 import java.util.List;
 import java.util.function.Function;
@@ -28,6 +29,13 @@ public static <I, O> Function<Iterable<I>, Iterable<O>> bothFlat(final Function<
 			}
 		}
 		
+		public interface Arrays {
+			@SuppressWarnings("unchecked")
+			public static <I, O> Function<I[], O[]> liftBoth(final Function<I, O> function, Class<O> cls) {
+				return is -> java.util.Arrays.stream(is).map(function).toArray(size -> (O[])Array.newInstance(cls, size));
+			}
+		}
+		
 		public interface Lists {
 			public static <I, O> Function<List<I>, List<O>> liftBoth(final Function<I, O> function) {
 				return iter -> iter.stream().map(function).collect(Collectors.toList());
diff --git a/src/test/java/org/scijava/ops/LiftTest.java b/src/test/java/org/scijava/ops/LiftTest.java
@@ -59,8 +59,11 @@ public void testliftFunction() throws ValidityException {
 
 		Function<Iterable<Double>, Iterable<Double>> liftedToIterable = Maps.Functions.Iterables.liftBoth(powFunction);
 		Iterable<Double> res2 = liftedToIterable.apply(Arrays.asList(1.0, 2.0, 3.0, 4.0));
-
 		arrayEquals(toArray(res2), 1.0, 4.0, 9.0, 16.0);
+		
+		Function<Double[], Double[]> liftedToArray = Maps.Functions.Arrays.liftBoth(powFunction, Double.class);
+		Double[] res3 = liftedToArray.apply(new Double[]{1.0, 2.0, 3.0, 4.0});
+		arrayEquals(Arrays.stream(res3).mapToDouble(d -> d).toArray(), 1.0, 4.0, 9.0, 16.0);
 	}
 
 	private static double[] toArray(Iterable<Double> iter) {
