#841 - Add Monoid instances #942
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| interface EitherMonoidInstance<L, R> : EitherSemigroupInstance<L, R>, Monoid<Either<L, R>> { | ||
| fun MO(): Monoid<R> | ||
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| override fun SG(): Semigroup<R> { |
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style nit pick, favor simple expressions whenever possible:
override fun SG(): Semigroup<R> = MO()| interface TryMonoidInstance<A> : TrySemigroupInstance<A>, Monoid<Try<A>> { | ||
| fun MO(): Monoid<A> | ||
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| override fun SG(): Semigroup<A> { |
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style nit pick, favor simple expressions whenever possible:
override fun SG(): Semigroup<A> = MO()
| is Either.Left -> this | ||
| is Either.Right -> { val x = this.b; when (b) { | ||
| is Either.Left -> b | ||
| is Either.Right -> Either.Right(SG().run { x.combine(b.b) }) |
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Could this be done without the intermediate variable as this.b.combine(b.b)?
| fun SG(): Semigroup<A> | ||
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| override fun Try<A>.combine(b: Try<A>): Try<A> = | ||
| when (this) { |
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I'd move these functions to the datatype, reference them here instead.
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I couldn't find a way to do that given the dependency on SG and the semigroup interface. Is there a good example to follow given that core doesn't import typeclasses to avoid a circular dependency?
| @@ -1,11 +1,56 @@ | |||
| package arrow.instances | |||
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| import arrow.Kind | |||
| import arrow.core.* | |||
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I'm not sure why my editor is making that change, but I can revert if you'd like?
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Sure, although it isn't a blocker.
Codecov Report
@@ Coverage Diff @@
## master #942 +/- ##
===========================================
+ Coverage 45.42% 45.52% +0.1%
Complexity 647 647
===========================================
Files 309 309
Lines 7975 7997 +22
Branches 859 869 +10
===========================================
+ Hits 3623 3641 +18
Misses 4035 4035
- Partials 317 321 +4
Continue to review full report at Codecov.
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add semigrouplaws tests add tests for combine
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So far so good. Tell us when it's ready to review! |
Adding this as a WIP for now. Would there be more required for Try/Either?