Add Supplier -> OpRunner support

gselzer · ctrueden · commit 3b028dda8fc0 · 2019-09-22T17:22:16.000+02:00
diff --git a/src/main/java/org/scijava/ops/transform/FunctionalToOpRunnerTransformer.java b/src/main/java/org/scijava/ops/transform/FunctionalToOpRunnerTransformer.java
@@ -37,6 +37,7 @@
 import java.util.List;
 import java.util.function.BiFunction;
 import java.util.function.Function;
+import java.util.function.Supplier;
 import java.util.stream.Stream;
 
 import org.scijava.ops.OpService;
@@ -137,6 +138,7 @@ private static OpRunner computerToRunner(final Object src, final Class<?> srcFun
 	private static OpRunner functionToRunner(final Object src, final Class<?> srcFunctionalRawType)
 		throws OpTransformationException
 	{
+		if (src instanceof Supplier) return OpRunners.Functions.toRunner((Supplier<?>) src);
 		if (src instanceof Function) return OpRunners.Functions.toRunner((Function<?, ?>) src);
 		if (src instanceof BiFunction) return OpRunners.Functions.toRunner((BiFunction<?, ?, ?>) src);
 		if (src instanceof Function3) return OpRunners.Functions.toRunner((Function3<?, ?, ?, ?>) src);
diff --git a/src/main/java/org/scijava/ops/util/OpRunners.java b/src/main/java/org/scijava/ops/util/OpRunners.java
@@ -2,6 +2,7 @@
 
 import java.util.function.BiFunction;
 import java.util.function.Function;
+import java.util.function.Supplier;
 
 import org.scijava.ops.core.computer.BiComputer;
 import org.scijava.ops.core.computer.Computer;
@@ -26,6 +27,28 @@
 // 2. Improve the matcher to respect the ops that implement KnowsTypes
 public class OpRunners {
 	public static class Functions {
+		
+		public static <O> OpRunner toRunner(Supplier<O> function) {
+			return new OpRunner() {
+				
+				@Override
+				public Object getAdaptedOp() {
+					return function;
+				}
+
+				@Override
+				public Nil<?>[] inTypes() {
+					return new Nil<?>[] {};
+				}
+
+				@SuppressWarnings("unchecked")
+				@Override
+				public O run(Object[] args) {
+					return function.get();
+				}
+
+			};
+		}
 
 		public static <I, O> OpRunner toRunner(Function<I, O> function) {
 			return new OpRunner() {
