adding Tuple2/3/4/5#fill to fill each tuple instance with a given value

jnape · jnape · commit 538b6454b8ef · 2017-01-08T14:08:53.000-06:00
diff --git a/src/main/java/com/jnape/palatable/lambda/adt/hlist/Tuple2.java b/src/main/java/com/jnape/palatable/lambda/adt/hlist/Tuple2.java
@@ -57,8 +57,8 @@ public _2 _2() {
      * Destructure and apply this tuple to a function accepting the same number of arguments as this tuple's
      * slots. This can be thought of as a kind of dual to uncurrying a function and applying a tuple to it.
      *
-     * @param fn the function to apply
-     * @param <R>        the return type of the function
+     * @param fn  the function to apply
+     * @param <R> the return type of the function
      * @return the result of applying the destructured tuple to the function
      */
     public <R> R into(BiFunction<? super _1, ? super _2, ? extends R> fn) {
@@ -115,4 +115,14 @@ public static <K, V> Tuple2<K, V> fromEntry(Map.Entry<K, V> entry) {
         return new Tuple2<>(entry.getKey(), singletonHList(entry.getValue()));
     }
 
+    /**
+     * Given a value of type <code>A</code>, produced an instance of this tuple with each slot set to that value.
+     *
+     * @param a   the value to fill the tuple with
+     * @param <A> the value type
+     * @return the filled tuple
+     */
+    public static <A> Tuple2<A, A> fill(A a) {
+        return tuple(a, a);
+    }
 }
diff --git a/src/main/java/com/jnape/palatable/lambda/adt/hlist/Tuple3.java b/src/main/java/com/jnape/palatable/lambda/adt/hlist/Tuple3.java
@@ -98,4 +98,16 @@ public <_2Prime, _3Prime> Tuple3<_1, _2Prime, _3Prime> biMap(Function<? super _2
                                                                  Function<? super _3, ? extends _3Prime> rFn) {
         return new Tuple3<>(_1(), tail().biMap(lFn, rFn));
     }
+
+    /**
+     * Given a value of type <code>A</code>, produced an instance of this tuple with each slot set to that value.
+     *
+     * @param a   the value to fill the tuple with
+     * @param <A> the value type
+     * @return the filled tuple
+     * @see Tuple2#fill
+     */
+    public static <A> Tuple3<A, A, A> fill(A a) {
+        return tuple(a, a, a);
+    }
 }
diff --git a/src/main/java/com/jnape/palatable/lambda/adt/hlist/Tuple4.java b/src/main/java/com/jnape/palatable/lambda/adt/hlist/Tuple4.java
@@ -110,4 +110,16 @@ public <_3Prime, _4Prime> Tuple4<_1, _2, _3Prime, _4Prime> biMap(Function<? supe
                                                                      Function<? super _4, ? extends _4Prime> rFn) {
         return new Tuple4<>(_1(), tail().biMap(lFn, rFn));
     }
+
+    /**
+     * Given a value of type <code>A</code>, produced an instance of this tuple with each slot set to that value.
+     *
+     * @param a   the value to fill the tuple with
+     * @param <A> the value type
+     * @return the filled tuple
+     * @see Tuple2#fill
+     */
+    public static <A> Tuple4<A, A, A, A> fill(A a) {
+        return tuple(a, a, a, a);
+    }
 }
diff --git a/src/main/java/com/jnape/palatable/lambda/adt/hlist/Tuple5.java b/src/main/java/com/jnape/palatable/lambda/adt/hlist/Tuple5.java
@@ -108,4 +108,16 @@ public <_4Prime, _5Prime> Tuple5<_1, _2, _3, _4Prime, _5Prime> biMap(Function<?
                                                                          Function<? super _5, ? extends _5Prime> rFn) {
         return new Tuple5<>(_1(), tail().biMap(lFn, rFn));
     }
+
+    /**
+     * Given a value of type <code>A</code>, produced an instance of this tuple with each slot set to that value.
+     *
+     * @param a   the value to fill the tuple with
+     * @param <A> the value type
+     * @return the filled tuple
+     * @see Tuple2#fill
+     */
+    public static <A> Tuple5<A, A, A, A, A> fill(A a) {
+        return tuple(a, a, a, a, a);
+    }
 }
diff --git a/src/test/java/com/jnape/palatable/lambda/adt/hlist/Tuple2Test.java b/src/test/java/com/jnape/palatable/lambda/adt/hlist/Tuple2Test.java
@@ -61,6 +61,11 @@ public void into() {
         assertEquals("foo1", tuple.into((s, i) -> s + i));
     }
 
+    @Test
+    public void fill() {
+        assertEquals(tuple("foo", "foo"), Tuple2.fill("foo"));
+    }
+
     @Test
     public void functorProperties() {
         assertEquals(new Tuple2<>(1, new SingletonHList<>("2")), tuple2.fmap(Object::toString));
diff --git a/src/test/java/com/jnape/palatable/lambda/adt/hlist/Tuple3Test.java b/src/test/java/com/jnape/palatable/lambda/adt/hlist/Tuple3Test.java
@@ -60,6 +60,11 @@ public void into() {
         assertEquals("foo12.0", tuple.into((s, i, d) -> s + i + d));
     }
 
+    @Test
+    public void fill() {
+        assertEquals(tuple("foo", "foo", "foo"), Tuple3.fill("foo"));
+    }
+
     @Test
     public void functorProperties() {
         assertEquals(new Tuple3<>(1, new Tuple2<>("2", new SingletonHList<>("3"))), tuple3.fmap(Object::toString));
diff --git a/src/test/java/com/jnape/palatable/lambda/adt/hlist/Tuple4Test.java b/src/test/java/com/jnape/palatable/lambda/adt/hlist/Tuple4Test.java
@@ -63,6 +63,11 @@ public void into() {
         assertEquals("foo12.0false", tuple.into((s, i, d, b) -> s + i + d + b));
     }
 
+    @Test
+    public void fill() {
+        assertEquals(tuple("foo", "foo", "foo", "foo"), Tuple4.fill("foo"));
+    }
+
     @Test
     public void functorProperties() {
         assertEquals(new Tuple4<>(1, new Tuple3<>("2", new Tuple2<>('3', new SingletonHList<>(true)))), tuple4.fmap(x -> !x));
diff --git a/src/test/java/com/jnape/palatable/lambda/adt/hlist/Tuple5Test.java b/src/test/java/com/jnape/palatable/lambda/adt/hlist/Tuple5Test.java
@@ -61,6 +61,11 @@ public void randomAccess() {
         verifyNoMoreInteractions(spiedTail);
     }
 
+    @Test
+    public void fill() {
+        assertEquals(tuple("foo", "foo", "foo", "foo", "foo"), Tuple5.fill("foo"));
+    }
+
     @Test
     public void functorProperties() {
         assertEquals(new Tuple5<>(1, new Tuple4<>("2", new Tuple3<>('3', new Tuple2<>(false, new SingletonHList<>("5"))))),
