Fn0 is now Callable

jnape · jnape · commit 1e7ab1f0b36f · 2018-11-03T22:33:35.000-05:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -16,7 +16,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
 - `Concat` monoid can now fold infinite iterables
 - all `Function<? super XXX, Boolean>` are now `Function<? super XXX, ? extends Boolean>` for better compatibility  
 - `Either#diverge` returns a `Choice3`
-- `Maybe` is now a `CoProduct2` of `Unit` and `A`  
+- `Maybe` is now a `CoProduct2` of `Unit` and `A`    
+- `Fn0` now additionally implements `Callable`
 
 ### Added
 - `Predicate#predicate` static factory method
diff --git a/src/main/java/com/jnape/palatable/lambda/functions/Fn0.java b/src/main/java/com/jnape/palatable/lambda/functions/Fn0.java
@@ -4,6 +4,7 @@
 import com.jnape.palatable.lambda.functor.Applicative;
 import com.jnape.palatable.lambda.monad.Monad;
 
+import java.util.concurrent.Callable;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
@@ -16,9 +17,10 @@
  * @param <A> the result type
  * @see Fn1
  * @see Supplier
+ * @see Callable
  */
 @FunctionalInterface
-public interface Fn0<A> extends Fn1<Unit, A>, Supplier<A> {
+public interface Fn0<A> extends Fn1<Unit, A>, Supplier<A>, Callable<A> {
 
     A apply();
 
@@ -85,7 +87,12 @@ default <B> Fn0<B> andThen(Function<? super A, ? extends B> after) {
 
     @Override
     default A get() {
-        return apply(UNIT);
+        return apply();
+    }
+
+    @Override
+    default A call() {
+        return apply();
     }
 
     /**
