CheckedRunnable and CheckedSupplier convenience/conversion methods

jnape · jnape · commit 150d9e6b0130 · 2018-03-10T16:54:53.000-06:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -27,6 +27,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
 - `Both`, for dually applying two functions and producing a `Tuple2` of their results
 - `Lens#both`, for dually focusing with two lenses at once
 - `IfThenElse`, an expression form for `if` statements
+- `CheckedRunnable` and `CheckedSupplier` conversion and convenience methods
 
 ### Deprecated
 - `Either#trying` in favor of `Try#trying` 
diff --git a/src/main/java/com/jnape/palatable/lambda/functions/specialized/checked/CheckedFn1.java b/src/main/java/com/jnape/palatable/lambda/functions/specialized/checked/CheckedFn1.java
@@ -26,5 +26,12 @@ default B apply(A a) {
         }
     }
 
+    /**
+     * A version of {@link Fn1#apply} that can throw checked exceptions.
+     *
+     * @param a the function argument
+     * @return the application of the argument to the function
+     * @throws T any exception that can be thrown by this method
+     */
     B checkedApply(A a) throws T;
 }
diff --git a/src/main/java/com/jnape/palatable/lambda/functions/specialized/checked/CheckedRunnable.java b/src/main/java/com/jnape/palatable/lambda/functions/specialized/checked/CheckedRunnable.java
@@ -1,5 +1,8 @@
 package com.jnape.palatable.lambda.functions.specialized.checked;
 
+import com.jnape.palatable.lambda.adt.Unit;
+
+import static com.jnape.palatable.lambda.adt.Unit.UNIT;
 import static com.jnape.palatable.lambda.functions.specialized.checked.Runtime.throwChecked;
 
 /**
@@ -21,5 +24,35 @@ default void run() {
         }
     }
 
+    /**
+     * A version of {@link Runnable#run()} that can throw checked exceptions.
+     *
+     * @throws T any exception that can be thrown by this method
+     */
     void checkedRun() throws T;
+
+    /**
+     * Convert this {@link CheckedRunnable} to a {@link CheckedSupplier} that returns {@link Unit}.
+     *
+     * @return the checked supplier
+     */
+    default CheckedSupplier<T, Unit> toSupplier() {
+        return () -> {
+            run();
+            return UNIT;
+        };
+    }
+
+    /**
+     * Convenience static factory method for constructing a {@link CheckedRunnable} without an explicit cast or type
+     * attribution at the call site.
+     *
+     * @param runnable the checked runnable
+     * @param <T>      the inferred Throwable type
+     * @return the checked runnable
+     */
+    static <T extends Throwable> CheckedRunnable<T> checked(CheckedRunnable<T> runnable) {
+        return runnable::run;
+    }
+
 }
diff --git a/src/main/java/com/jnape/palatable/lambda/functions/specialized/checked/CheckedSupplier.java b/src/main/java/com/jnape/palatable/lambda/functions/specialized/checked/CheckedSupplier.java
@@ -31,4 +31,26 @@ default A get() {
      * @throws T any exception that can be thrown by this method
      */
     A checkedGet() throws T;
+
+    /**
+     * Convert this {@link CheckedSupplier} to a {@link CheckedRunnable}.
+     *
+     * @return the checked runnable
+     */
+    default CheckedRunnable<T> toRunnable() {
+        return this::get;
+    }
+
+    /**
+     * Convenience static factory method for constructing a {@link CheckedSupplier} without an explicit cast or type
+     * attribution at the call site.
+     *
+     * @param supplier the checked supplier
+     * @param <T>      the inferred Throwable type
+     * @param <A>      the supplier return type
+     * @return the checked supplier
+     */
+    static <T extends Throwable, A> CheckedSupplier<T, A> checked(CheckedSupplier<T, A> supplier) {
+        return supplier::get;
+    }
 }

Original file line number	Diff line number	Diff line change
`@@ -26,5 +26,12 @@ default B apply(A a) {`
`26`	`26`	`}`
`27`	`27`	`}`
`28`	`28`
	`29`	`+ /**`
	`30`	`+ * A version of {@link Fn1#apply} that can throw checked exceptions.`
	`31`	`+ *`
	`32`	`+ * @param a the function argument`
	`33`	`+ * @return the application of the argument to the function`
	`34`	`+ * @throws T any exception that can be thrown by this method`
	`35`	`+ */`
`29`	`36`	`B checkedApply(A a) throws T;`
`30`	`37`	`}`