Added collectFirstSome to Chain and NonEmptyChain. Overrided collectF…

…irst and collectFirstSome in the Foldable instances of Chain and NonEmptyChain.
LMnet · Apr 18, 2019 · e78385d · e78385d
1 parent 92fc8b3
commit e78385d
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Showing 2 changed files with 27 additions and 6 deletions.
diff --git a/core/src/main/scala/cats/data/Chain.scala b/core/src/main/scala/cats/data/Chain.scala
@@ -146,9 +146,9 @@ sealed abstract class Chain[+A] {
     }
 
   /**
-    * Finds the first element of this `Chain` for which the given partial
-    * function is defined, and applies the partial function to it.
-    */
+   * Finds the first element of this `Chain` for which the given partial
+   * function is defined, and applies the partial function to it.
+   */
   final def collectFirst[B](pf: PartialFunction[A, B]): Option[B] = {
     var result: Option[B] = None
     foreachUntil { a =>
@@ -162,6 +162,13 @@ sealed abstract class Chain[+A] {
     result
   }
 
+  /**
+   * Like `collectFirst` from `scala.collection.Traversable` but takes `A => Option[B]`
+   * instead of `PartialFunction`s.
+   */
+  final def collectFirstSome[B](f: A => Option[B]): Option[B] =
+    collectFirst(Function.unlift(f))
+
   /**
    * Remove elements not matching the predicate
    */
@@ -577,6 +584,8 @@ sealed abstract private[data] class ChainInstances extends ChainInstances1 {
       override def forall[A](fa: Chain[A])(p: A => Boolean): Boolean = fa.forall(p)
       override def find[A](fa: Chain[A])(f: A => Boolean): Option[A] = fa.find(f)
       override def size[A](fa: Chain[A]): Long = fa.length
+      override def collectFirst[A, B](fa: Chain[A])(pf: PartialFunction[A, B]): Option[B] = fa.collectFirst(pf)
+      override def collectFirstSome[A, B](fa: Chain[A])(f: A => Option[B]): Option[B] = fa.collectFirstSome(f)
 
       def coflatMap[A, B](fa: Chain[A])(f: Chain[A] => B): Chain[B] = {
         @tailrec def go(as: Chain[A], res: ListBuffer[B]): Chain[B] =

diff --git a/core/src/main/scala/cats/data/NonEmptyChain.scala b/core/src/main/scala/cats/data/NonEmptyChain.scala
@@ -240,11 +240,17 @@ class NonEmptyChainOps[A](private val value: NonEmptyChain[A]) extends AnyVal {
   final def collect[B](pf: PartialFunction[A, B]): Chain[B] = toChain.collect(pf)
 
   /**
-    * Finds the first element of this `NonEmptyChain` for which the given partial
-    * function is defined, and applies the partial function to it.
-    */
+   * Finds the first element of this `NonEmptyChain` for which the given partial
+   * function is defined, and applies the partial function to it.
+   */
   final def collectFirst[B](pf: PartialFunction[A, B]): Option[B] = toChain.collectFirst(pf)
 
+  /**
+   * Like `collectFirst` from `scala.collection.Traversable` but takes `A => Option[B]`
+   * instead of `PartialFunction`s.
+   */
+  final def collectFirstSome[B](f: A => Option[B]): Option[B] = toChain.collectFirstSome(f)
+
   /**
    * Filters all elements of this chain that do not satisfy the given predicate.
    */
@@ -479,6 +485,12 @@ sealed abstract private[data] class NonEmptyChainInstances extends NonEmptyChain
 
       override def toNonEmptyList[A](fa: NonEmptyChain[A]): NonEmptyList[A] =
         fa.toNonEmptyList
+
+      override def collectFirst[A, B](fa: NonEmptyChain[A])(pf: PartialFunction[A, B]): Option[B] =
+        fa.collectFirst(pf)
+
+      override def collectFirstSome[A, B](fa: NonEmptyChain[A])(f: A => Option[B]): Option[B] =
+        fa.collectFirstSome(f)
     }
 
   implicit def catsDataOrderForNonEmptyChain[A: Order]: Order[NonEmptyChain[A]] =