add methods for try and pair

Author: johnynek

core/src/main/scala/cats/instances/try.scala

@@ -120,6 +120,36 @@ trait TryInstances extends TryInstances1 {
 
       override def map[A, B](ta: Try[A])(f: A => B): Try[B] = ta.map(f)
 
+      override def as[A, B](ta: Try[A], b: B): Try[B] =
+        ta match {
+          case Success(_)    => Success(b)
+          case err: Failure[?] => castFailure[B](err)
+        }
+
+      override def tupleLeft[A, B](ta: Try[A], b: B): Try[(B, A)] =
+        ta match {
+          case Success(a)    => Success((b, a))
+          case err: Failure[?] => castFailure[(B, A)](err)
+        }
+
+      override def tupleRight[A, B](ta: Try[A], b: B): Try[(A, B)] =
+        ta match {
+          case Success(a)    => Success((a, b))
+          case err: Failure[?] => castFailure[(A, B)](err)
+        }
+
+      override def fproduct[A, B](ta: Try[A])(f: A => B): Try[(A, B)] =
+        ta match {
+          case Success(a)    => Success((a, f(a)))
+          case err: Failure[?] => castFailure[(A, B)](err)
+        }
+
+      override def fproductLeft[A, B](ta: Try[A])(f: A => B): Try[(B, A)] =
+        ta match {
+          case Success(a)    => Success((f(a), a))
+          case err: Failure[?] => castFailure[(B, A)](err)
+        }
+
       override def reduceLeftToOption[A, B](fa: Try[A])(f: A => B)(g: (B, A) => B): Option[B] =
         fa.map(f).toOption
 
@@ -165,6 +195,12 @@ trait TryInstances extends TryInstances1 {
           case Success(a) => a :: Nil
         }
 
+      override def unzip[A, B](fab: Try[(A, B)]): (Try[A], Try[B]) =
+        fab match {
+          case Success((a, b)) => (Success(a), Success(b))
+          case err: Failure[?]   => (castFailure[A](err), castFailure[B](err))
+        }
+
       override def isEmpty[A](fa: Try[A]): Boolean = fa.isFailure
 
       override def catchNonFatal[A](a: => A)(implicit ev: Throwable <:< Throwable): Try[A] = Try(a)

core/src/main/scala/cats/instances/tuple.scala

@@ -50,6 +50,27 @@ private[instances] trait Tuple2InstancesBinCompat0 {
 
   implicit val catsDataFunctorForPair: Functor[λ[P => (P, P)]] = new Functor[λ[P => (P, P)]] {
     override def map[A, B](fa: (A, A))(f: A => B): (B, B) = (f(fa._1), f(fa._2))
+
+    override def as[A, B](fa: (A, A), b: B): (B, B) = (b, b)
+
+    override def tupleLeft[A, B](fa: (A, A), b: B): ((B, A), (B, A)) =
+      ((b, fa._1), (b, fa._2))
+
+    override def tupleRight[A, B](fa: (A, A), b: B): ((A, B), (A, B)) =
+      ((fa._1, b), (fa._2, b))
+
+    override def fproduct[A, B](fa: (A, A))(f: A => B): ((A, B), (A, B)) =
+      ((fa._1, f(fa._1)), (fa._2, f(fa._2)))
+
+    override def fproductLeft[A, B](fa: (A, A))(f: A => B): ((B, A), (B, A)) =
+      ((f(fa._1), fa._1), (f(fa._2), fa._2))
+
+    override def unzip[A, B](fab: ((A, B), (A, B))): ((A, A), (B, B)) =
+      ((fab._1._1, fab._2._1), (fab._1._2, fab._2._2))
+
+    private val unit: (Unit, Unit) = ((), ())
+
+    override def void[A](fa: (A, A)): (Unit, Unit) = unit
   }
 }