From 9dd3b61620faefec451a3d936044949581433f91 Mon Sep 17 00:00:00 2001
From: LMnet <lmnet89@gmail.com>
Date: Wed, 1 May 2019 14:15:47 +0700
Subject: [PATCH] Benchmarks for collectFirst on Chain

---
 .../cats/bench/ChainCollectFirstBench.scala   | 108 ++++++++++++++++++
 core/src/main/scala/cats/data/Chain.scala     |  15 ++-
 2 files changed, 121 insertions(+), 2 deletions(-)
 create mode 100644 bench/src/main/scala/cats/bench/ChainCollectFirstBench.scala

diff --git a/bench/src/main/scala/cats/bench/ChainCollectFirstBench.scala b/bench/src/main/scala/cats/bench/ChainCollectFirstBench.scala
new file mode 100644
index 0000000000..b718667a05
--- /dev/null
+++ b/bench/src/main/scala/cats/bench/ChainCollectFirstBench.scala
@@ -0,0 +1,108 @@
+package cats.bench
+
+import cats.Foldable
+import cats.data.Chain
+import org.openjdk.jmh.annotations.{Benchmark, Scope, State}
+
+@State(Scope.Thread)
+class ChainCollectFirstBench {
+
+  private val foldableChain = Foldable[Chain]
+
+  private val small = Chain(1, 2, 3, 4, 5)
+  private val smallLast = 5
+
+  private val medium = (0 to 10)
+    .foldLeft(Chain.empty[Int])((acc, _) => acc ++ Chain.fromSeq(0 to 10))
+  private val mediumLast = 10 * 10
+
+  private val large = (0 to 1000)
+    .foldLeft(Chain.empty[Int])((acc, _) => acc ++ Chain.fromSeq(0 to 1000))
+  private val largeLast = 1000 * 1000
+
+  @Benchmark
+  def collectFirstSmallNew: Option[Int] = small.collectFirst {
+    case x if x == smallLast => x
+  }
+
+  @Benchmark
+  def collectFirstSmallFoldable: Option[Int] = foldableChain.collectFirst(small) {
+    case x if x == smallLast => x
+  }
+
+  @Benchmark
+  def collectFirstMediumNew: Option[Int] = medium.collectFirst {
+    case x if x == mediumLast => x
+  }
+
+  @Benchmark
+  def collectFirstMediumFoldable: Option[Int] = foldableChain.collectFirst(medium) {
+    case x if x == mediumLast => x
+  }
+
+  @Benchmark
+  def collectFirstLargeNew: Option[Int] = medium.collectFirst {
+    case x if x == largeLast => x
+  }
+
+  @Benchmark
+  def collectFirstLargeFoldable: Option[Int] = foldableChain.collectFirst(medium) {
+    case x if x == largeLast => x
+  }
+
+
+
+  @Benchmark
+  def collectFirstSomeSmallNew: Option[Int] = small.collectFirstSome {
+    case x if x == smallLast => Some(x)
+    case _ => None
+  }
+
+  @Benchmark
+  def collectFirstSome2SmallNew: Option[Int] = small.collectFirstSome2 {
+    case x if x == smallLast => Some(x)
+    case _ => None
+  }
+
+  @Benchmark
+  def collectFirstSomeSmallFoldable: Option[Int] = foldableChain.collectFirstSome(small) {
+    case x if x == smallLast => Some(x)
+    case _ => None
+  }
+
+  @Benchmark
+  def collectFirstSomeMediumNew: Option[Int] = medium.collectFirstSome {
+    case x if x == mediumLast => Some(x)
+    case _ => None
+  }
+
+  @Benchmark
+  def collectFirstSome2MediumNew: Option[Int] = medium.collectFirstSome2 {
+    case x if x == mediumLast => Some(x)
+    case _ => None
+  }
+
+  @Benchmark
+  def collectFirstSomeMediumFoldable: Option[Int] = foldableChain.collectFirstSome(medium) {
+    case x if x == mediumLast => Some(x)
+    case _ => None
+  }
+
+  @Benchmark
+  def collectFirstSomeLargeNew: Option[Int] = medium.collectFirstSome {
+    case x if x == largeLast => Some(x)
+    case _ => None
+  }
+
+  @Benchmark
+  def collectFirstSome2LargeNew: Option[Int] = medium.collectFirstSome2 {
+    case x if x == largeLast => Some(x)
+    case _ => None
+  }
+
+  @Benchmark
+  def collectFirstSomeLargeFoldable: Option[Int] = foldableChain.collectFirstSome(medium) {
+    case x if x == largeLast => Some(x)
+    case _ => None
+  }
+}
diff --git a/core/src/main/scala/cats/data/Chain.scala b/core/src/main/scala/cats/data/Chain.scala
index d15fd4e138..faff843952 100644
--- a/core/src/main/scala/cats/data/Chain.scala
+++ b/core/src/main/scala/cats/data/Chain.scala
@@ -169,6 +169,19 @@ sealed abstract class Chain[+A] {
   final def collectFirstSome[B](f: A => Option[B]): Option[B] =
     collectFirst(Function.unlift(f))
 
+  final def collectFirstSome2[B](f: A => Option[B]): Option[B] = {
+    var result: Option[B] = None
+    foreachUntil { a =>
+      val x = f(a)
+      if (x.isDefined) {
+        result = x
+        true
+      } else false
+    }
+    result
+  }
+
+
   /**
    * Remove elements not matching the predicate
    */
@@ -584,8 +597,6 @@ 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] =