Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Representable instance for Tuple2K #3832

Merged
merged 3 commits into from
Mar 29, 2021
Merged

Representable instance for Tuple2K #3832

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
36feaad
Representable instance for Tuple2K
TimWSpence Mar 19, 2021
8207ed1
:heart: scala 2.12 implicit resolution
TimWSpence Mar 19, 2021
c1baaac
Remove unnecessary implicits
TimWSpence Mar 24, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
22 changes: 22 additions & 0 deletions core/src/main/scala/cats/data/Tuple2K.scala
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -96,6 +96,28 @@ sealed abstract private[data] class Tuple2KInstances1 extends Tuple2KInstances2
def F: Foldable[F] = FF
def G: Foldable[G] = GF
}

implicit def catsDataRepresentableForTuple2K[F[_], G[_]](implicit
FF: Representable[F],
GG: Representable[G]
): Representable.Aux[Tuple2K[F, G, *], Either[FF.Representation, GG.Representation]] =
new Representable[Tuple2K[F, G, *]] {
type Representation = Either[FF.Representation, GG.Representation]

val F = new Tuple2KFunctor[F, G] {
val F = FF.F
val G = GG.F
}

def index[A](f: Tuple2K[F, G, A]): Representation => A = {
case Left(i) => FF.index(f.first)(i)
case Right(i) => GG.index(f.second)(i)
}

def tabulate[A](f: Representation => A): Tuple2K[F, G, A] =
Tuple2K(FF.tabulate((x: FF.Representation) => f(Left(x))), GG.tabulate((x: GG.Representation) => f(Right(x))))
}

}

sealed abstract private[data] class Tuple2KInstances2 extends Tuple2KInstances3 {
Expand Down
32 changes: 32 additions & 0 deletions tests/src/test/scala/cats/tests/Tuple2KSuite.scala
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@ import cats.laws.discipline.arbitrary._
import cats.laws.discipline.eq._
import cats.laws.discipline.SemigroupalTests.Isomorphisms
import cats.syntax.eq._
import org.scalacheck.{Arbitrary, Cogen}
import org.scalacheck.Prop._

class Tuple2KSuite extends CatsSuite {
Expand Down Expand Up @@ -41,6 +42,37 @@ class Tuple2KSuite extends CatsSuite {

checkAll("Show[Tuple2K[Option, Option, Int]]", SerializableTests.serializable(Show[Tuple2K[Option, Option, Int]]))

{
type Pair[A] = (A, A)

//Scala 2.12 implicit resolution absolutely loses its mind here
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

do these need to be implicit if you are passing them explicitly? Can we just make them normal vals?

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yep, good call! 👍

implicit val help_scala2_12: Representable.Aux[Tuple2K[Pair, Pair, *], Either[Boolean, Boolean]] =
Tuple2K.catsDataRepresentableForTuple2K[Pair, Pair]
implicit val a: Arbitrary[Int] = Arbitrary.arbInt
implicit val b: Arbitrary[Tuple2K[Pair, Pair, Int]] =
catsLawsArbitraryForTuple2K[Pair, Pair, Int]
implicit val c: Arbitrary[Either[Boolean, Boolean]] = Arbitrary.arbEither(Arbitrary.arbBool, Arbitrary.arbBool)
implicit val d: Arbitrary[(Either[Boolean, Boolean]) => Int] =
Arbitrary.arbFunction1(Arbitrary.arbInt, Cogen.cogenEither(Cogen.cogenBoolean, Cogen.cogenBoolean))
implicit val e: Eq[Tuple2K[Pair, Pair, Int]] = Tuple2K.catsDataEqForTuple2K[Pair, Pair, Int]
implicit val f: Eq[Int] = Eq.catsKernelInstancesForInt

checkAll(
"Representable[Tuple2K[Pair, Pair, *]]",
RepresentableTests[Tuple2K[Pair, Pair, *], Either[Boolean, Boolean]].representable[Int](
a,
b,
c,
d,
e,
f
)
)
checkAll("Representable[Tuple2K[Pair, Pair, *]]",
SerializableTests.serializable(Representable[Tuple2K[Pair, Pair, *]])
)
}

{
implicit val monoidK: MonoidK[ListWrapper] = ListWrapper.monoidK
checkAll("Tuple2K[ListWrapper, ListWrapper, *]", MonoidKTests[Tuple2K[ListWrapper, ListWrapper, *]].monoidK[Int])
Expand Down