SemigroupK consistency and fix; added compose tests. #751
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+ Renamed SemigroupK composedWith to compose for consistency with Applicative, Foldable, Reducible. + Fixed non-termination bug in SemigroupK compose(dWith). + Added tests for Applicative, Foldable, Reducible, SemigroupK composition.
| @@ -31,9 +31,9 @@ import simulacrum.{op, typeclass} | |||
| /** | |||
| * Compose two SemigroupK intsances. | |||
| */ | |||
| def composedWith[G[_]: SemigroupK]: SemigroupK[λ[α => F[G[α]]]] = | |||
| def compose[G[_]: SemigroupK]: SemigroupK[λ[α => F[G[α]]]] = | |||
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We have Alternative which extends both Applicative and MonoidK. Not that calling it composedWith is a particularly elegant solution, but do we run the risk of overloading ambiguities/annoyances with both composes being on the same instance?
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I think the right thing to do here is to add a compose to Alternative which composes a pair of Alternatives to an Alternative. I can add that to this PR or follow up afterwards.
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That sounds like a good solution to me. It might also mean we want to add something similar to MonoidK. I'm okay with that either going into this PR or a follow up one.
Current coverage is
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| new SemigroupK[λ[α => F[G[α]]]] { | ||
| def combine[A](x: F[G[A]], y: F[G[A]]): F[G[A]] = combine(x, y) | ||
| def combine[A](x: F[G[A]], y: F[G[A]]): F[G[A]] = self.combine(x, y) |
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👍 As mentioned here, there are probably some additional |
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I'll do a couple of follow up PRs for the issues that @ceedubs raised. |
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I agree with @ceedubs' comments, and also his 👍 Thanks! |
SemigroupK consistency and fix; added compose tests.
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Thanks, @milessabin! |
Applicative, Foldable, Reducible.
composition.