A sample implementation of grouped(by:) and keyed(by:). See the tests for details.
- Pitch: https://forums.swift.org/t/pitch-sequence-grouped-by-and-keyed-by/65511
- Proposal: https://github.com/apple/swift-evolution/pull/2078
Don't import this package. It's going to soon be deleted.
This code is being up-streamed into swift-algorithms in this PR