typelevel/cats

typeclass-based collections implementations

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#4,147 opened on Mar 9, 2022

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 (28 comments) (2 reactions) (0 assignees)Scala (1,241 forks)batch import
enhancementhelp wanted

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Description

This is a recurring idea, most recently by @johnynek in https://github.com/typelevel/cats/pull/4118#issuecomment-1022714696.

i.e. we should work towards having a typeclass based implementation of HashSet, SortedSet, HashMap, SortedMap that use only typeclasses, not the instance methods.

Although the issue comes up in Cats since this is where we house instances for Scala stdlib, this might be a better PR for cats-collections.

Contributor guide

Research direction
Study existing typeclass based implementations in cats collections or other libraries, then implement a typeclass for maps and sets based on the discussion in the issue.
Tech stack
scala
Domain
backend
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Scalatypeclasses
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
35