cats foldable syntax unnecessarity has Foldable implicit in its signature
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Description
when you import:
cats.syntax.foldable._
You got two methods which look very similar in terms in what they do:
.foldMap[B](f: A => B)(implicit B: Monoid[B]): B
.collectFold[B](f: A => B)(implicit F: Foldable[F], M: Monoid[M]): B
In case of a second one, it captures Foldable at the point of invocation not necessarily. Because Foldable typeclass was already established prior to this point. It also makes providing monoid instance explicitly harder because of additional Foldable instance that I have also supply.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start at the cats.syntax.foldable._ entry point and locate the collectFold method and its current implicit parameters. Review the issue discussion to resolve the proposed signature change, then verify that the resulting API and its behavior meet the agreed design.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- scala
- Domain
- backend-api-design
- Issue type
- Refactor
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 30/100