Add nullary computer + test

Treiblesschorle · ctrueden · commit 3abef667045c · 2019-04-18T12:02:50.000-05:00
diff --git a/src/main/java/org/scijava/ops/NullaryComputer.java b/src/main/java/org/scijava/ops/NullaryComputer.java
@@ -0,0 +1,13 @@
+package org.scijava.ops;
+
+import java.util.function.Consumer;
+
+@FunctionalInterface
+public interface NullaryComputer<O> extends Consumer<O> {
+	void compute(O out);
+
+	@Override
+	default void accept(O u) {
+		compute(u);
+	}
+}
diff --git a/src/main/java/org/scijava/ops/math/Zero.java b/src/main/java/org/scijava/ops/math/Zero.java
@@ -0,0 +1,28 @@
+package org.scijava.ops.math;
+
+import java.util.stream.IntStream;
+
+import org.scijava.ops.NullaryComputer;
+import org.scijava.ops.Op;
+import org.scijava.param.Parameter;
+import org.scijava.plugin.Plugin;
+import org.scijava.struct.ItemIO;
+
+public class Zero {
+
+	public interface MathZeroOp extends Op {
+	}
+	
+	// --------- Computers ---------
+
+	@Plugin(type = MathZeroOp.class)
+	@Parameter(key = "resultArray", type = ItemIO.BOTH)
+	public static class MathParallelPointwiseZeroDoubleArrayComputer implements MathZeroOp, NullaryComputer<double[]> {
+		@Override
+		public void compute(double[] out) {
+			IntStream.range(0, out.length).parallel().forEach(i -> {
+				out[i] = 0.0;
+			});
+		}
+	}
+}
diff --git a/src/test/java/org/scijava/ops/OpsTest.java b/src/test/java/org/scijava/ops/OpsTest.java
@@ -37,6 +37,7 @@
 import org.scijava.ops.math.Add.MathAddOp;
 import org.scijava.ops.math.Power.MathPowerOp;
 import org.scijava.ops.math.Sqrt.MathSqrtOp;
+import org.scijava.ops.math.Zero.MathZeroOp;
 import org.scijava.ops.types.Nil;
 
 public class OpsTest extends AbstractTestEnvironment {
@@ -99,6 +100,19 @@ public void binaryFunction() {
 		assert 86.0 == addFunction.apply(10.0, 76.0);
 	}
 
+	@Test
+	public void nullaryComputer() {
+		NullaryComputer<double[]> sqrtComputer = ops().findOp( //
+				MathZeroOp.class, new Nil<NullaryComputer<double[]>>() {
+				}, //
+				new Nil[] { nilDoubleArray }, //
+				nilDoubleArray//
+		);
+		double[] result = new double[] { 1.2323, 13231.1232, 37373773};
+		sqrtComputer.compute(result);
+		assert arrayEquals(result, 0.0, 0.0, 0.0);
+	}
+	
 	@Test
 	@SuppressWarnings("unchecked")
 	public void unaryComputer() {
