typelevel / typelevel/cats

Add support for Java 8 data types

Open
#1,281 6 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
Scala
Stars
5.5k
Forks
1.2k
Avg merge
2d 10h
Merged PRs (30d)
5

Description

Hello,

It would be nice to have support for Java 8 (semi) functional data types as they keep showing up more and more in third party libraries

specifically:

  • Monoid instance for Optional, Function and Stream
  • Bijection between Java Optional and Scala Option. Java Function and Scala function
  • Java 8 Stream has both pure and flatMap method so it maybe possible to provide monad instance for that?

Thanks

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

No files, tests, or entry points are named. Start by reviewing the existing typeclass instances and Java/Scala conversion patterns, then determine the intended scope for Optional, Function, and Stream support. Done means the agreed instances and bijections are implemented with coverage for the listed Java 8 types.

Written by the indexing model from the issue text.

Assessment

Tech stack
java, scala
Domain
tooling
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
25/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.