removed reduceRightK

typelevel · Dec 7, 2017 · 7796307 · 7796307
1 parent 9410809
commit 7796307
Show file tree

Hide file tree

Showing 4 changed files with 6 additions and 30 deletions.
diff --git a/build.sbt b/build.sbt
@@ -320,9 +320,7 @@ def mimaSettings(moduleName: String) = Seq(
       exclude[ReversedMissingMethodProblem]("cats.MonadError.rethrow"),
       exclude[ReversedMissingMethodProblem]("cats.syntax.MonadErrorSyntax.catsSyntaxMonadErrorRethrow"),
       exclude[DirectMissingMethodProblem]("cats.data.CokleisliArrow.id"),
-      exclude[IncompatibleResultTypeProblem]("cats.data.CokleisliArrow.id"),
-      exclude[ReversedMissingMethodProblem]("cats.Foldable.reduceRightK"),
-      exclude[ReversedMissingMethodProblem]("cats.Foldable#Ops.reduceRightK")
+      exclude[IncompatibleResultTypeProblem]("cats.data.CokleisliArrow.id")
     )
   }
 )

diff --git a/core/src/main/scala/cats/Foldable.scala b/core/src/main/scala/cats/Foldable.scala
@@ -244,24 +244,6 @@ import Foldable.sentinel
       A.combine(acc, a)
     }
 
-  /**
-   * Like `foldK` but from the right side.
-   * One use case would be endo functions (`A => A`) chaining
-   * because the default MonoidK instance for endo functions
-   * is using `compose` rather than the `andThen`
-   * {{{
-   * scala> import cats.implicits._, cats.Endo
-   * scala> val l: List[Endo[Int]] = List(_ * 2, _ + 3)
-   * scala> val f = l.reduceRightK //using `compose` to chain the functions
-   * scala> f(1)
-   * res0: Int = 5
-   * }}}
-   */
-  def reduceRightK[G[_], A](fga: F[G[A]])(implicit G: MonoidK[G]): G[A] =
-    foldRight(fga, Eval.now(G.empty[A])) { (ga, ega) =>
-      ega.map(rga => G.combineK(rga, ga))
-    }.value
-
   /**
    * Alias for [[fold]].
    */

diff --git a/tests/src/test/scala/cats/tests/FoldableSuite.scala b/tests/src/test/scala/cats/tests/FoldableSuite.scala
@@ -11,8 +11,7 @@ import cats.laws.discipline.arbitrary._
 
 abstract class FoldableSuite[F[_]: Foldable](name: String)(
   implicit ArbFInt: Arbitrary[F[Int]],
-     ArbFString: Arbitrary[F[String]],
-     ArbFListString: Arbitrary[F[List[String]]]) extends CatsSuite with PropertyChecks {
+     ArbFString: Arbitrary[F[String]]) extends CatsSuite with PropertyChecks {
 
   def iterator[T](fa: F[T]): Iterator[T]
 
@@ -36,12 +35,6 @@ abstract class FoldableSuite[F[_]: Foldable](name: String)(
     }
   }
 
-  test("Foldable#reduceRightK") {
-    forAll { (fi: F[List[String]]) =>
-      fi.reduceRightK should === (fi.foldRight(Eval.now(List.empty[String]))((l, el) => el.map(_ ++ l)).value)
-    }
-  }
-
   test("Foldable#partitionEither consistent with List#partition") {
     forAll { (fi: F[Int], f: Int => Either[String, String]) =>
       val list = Foldable[F].toList(fi)

diff --git a/tests/src/test/scala/cats/tests/ReducibleSuite.scala b/tests/src/test/scala/cats/tests/ReducibleSuite.scala
@@ -70,7 +70,10 @@ class ReducibleSuiteAdditional extends CatsSuite {
 
 }
 
-abstract class ReducibleSuite[F[_]: Reducible](name: String)(implicit ArbFInt: Arbitrary[F[Int]], ArbFString: Arbitrary[F[String]], ArbFListString: Arbitrary[F[List[String]]]) extends FoldableSuite[F](name) {
+abstract class ReducibleSuite[F[_]: Reducible](name: String)(
+  implicit ArbFInt: Arbitrary[F[Int]],
+    ArbFString: Arbitrary[F[String]]) extends FoldableSuite[F](name) {
+
   def range(start: Long, endInclusive: Long): F[Long]
 
   test(s"Reducible[$name].reduceLeftM stack safety") {