optimized map method to include Wrap check (#2995)

typelevel · Aug 20, 2019 · a97bb9a · a97bb9a
1 parent 241a7b9
commit a97bb9a
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/core/src/main/scala/cats/data/Chain.scala b/core/src/main/scala/cats/data/Chain.scala
@@ -137,8 +137,10 @@ sealed abstract class Chain[+A] {
   /**
    * Applies the supplied function to each element and returns a new Chain.
    */
-  final def map[B](f: A => B): Chain[B] =
-    fromSeq(iterator.map(f).toVector)
+  final def map[B](f: A => B): Chain[B] = this match {
+    case Wrap(seq) => Wrap(seq.map(f))
+    case _         => fromSeq(iterator.map(f).toVector)
+  }
 
   /**
    * Applies the supplied function to each element and returns a new Chain from the concatenated results