typelevel / typelevel/cats

No Bifoldable for cats.data.ValidatedNec

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Scala
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Description

@ (v: List[ValidatedNec[Error, Any]]).separate 
cmd8.sc:1: Could not find an instance of Bifoldable for cats.data.ValidatedNec
val res8 = (v: List[ValidatedNec[Error, Any]]).separate

But it works for the unaliased type:

@ (v: List[Validated[NonEmptyChain[Error], Any]]).separate 
res10: (List[NonEmptyChain[Error]], List[Any]) = (List(Singleton(a = Error(a = "a")), Append(leftNE = Singleton(a = Error(a = "b")), rightNE = Singleton(a = Error(a = "c")))), List())

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First steps

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Research direction

Reproduce the two ValidatedNec and Validated[NonEmptyChain] snippets and compare the available Bifoldable instances for those types. Trace the typeclass lookup for the alias and verify that the alias supports separate with the same result as the unaliased type.

Written by the indexing model from the issue text.

Assessment

Tech stack
scala
Domain
backend
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
42/100

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