Require Or instances for givens (#486)

typelevel · May 30, 2022 · bdd47fa · bdd47fa
1 parent 21c41a3
commit bdd47fa
Show file tree

Hide file tree

Showing 2 changed files with 8 additions and 4 deletions.
diff --git a/core/src/main/scala-3/cats/derived/DerivedEmptyK.scala b/core/src/main/scala-3/cats/derived/DerivedEmptyK.scala
@@ -30,9 +30,9 @@ object DerivedEmptyK:
     new EmptyK[[x] =>> F[G[x]]]:
       def empty[A] = F.unify.empty
 
-  given [F[_], G[_]](using NotGiven[Or[F]])(using F: Pure[F], G: Or[G]): DerivedEmptyK[[x] =>> F[G[x]]] =
+  given [F[_], G[_]](using NotGiven[Or[F]])(using F: DerivedPure.Or[F], G: Or[G]): DerivedEmptyK[[x] =>> F[G[x]]] =
     new EmptyK[[x] =>> F[G[x]]]:
-      def empty[A] = F.pure(G.unify.empty)
+      def empty[A] = F.unify.pure(G.unify.empty)
 
   given product[F[_]](using inst: K1.ProductInstances[Or, F]): DerivedEmptyK[F] =
     new EmptyK[F]:

diff --git a/core/src/main/scala-3/cats/derived/DerivedFunctor.scala b/core/src/main/scala-3/cats/derived/DerivedFunctor.scala
@@ -26,8 +26,12 @@ object DerivedFunctor:
   given [F[_], G[_]](using F: Or[F], G: Or[G]): DerivedFunctor[[x] =>> F[G[x]]] =
     F.unify.compose(G.unify)
 
-  given [F[_], G[_]](using F: Contravariant[F], G: Contravariant[G]): DerivedFunctor[[x] =>> F[G[x]]] =
-    F.compose(G)
+  given [F[_], G[_]](using
+      F: DerivedContravariant.Or[F],
+      G: DerivedContravariant.Or[G]
+  ): DerivedFunctor[[x] =>> F[G[x]]] =
+    given Contravariant[G] = G.unify
+    F.unify.compose[G]
 
   given [F[_]](using inst: => K1.Instances[Or, F]): DerivedFunctor[F] =
     given K1.Instances[Functor, F] = inst.unify