As the Haskell community has grown, and emphasis on development has moved from language to libraries, the need for a more formalised process for contributing to libraries has emerged. This page documents our 'best practices' for proposing changes to library interfaces (e.g. new modules or functions, removing functions), especially for modules in the base package.
In essence, we don't want proposals to go unnoticed, but changes to basic interfaces also need thorough consideration.
Under the old ad hoc system, unless a proposal meets with a chorus of approval, the only way to get a decision is from SimonM or unilateral action by some committer. This slowed development.
Creating a proposal
In order to ensure we have something concrete to discuss, please follow the following guidelines:
- Patch. The patch must compile against the head branch of the relevant library.
- Style. Follow the conventions in the library you are modifying.
- Documentation. It must include valid Haddock documentation.
- Tests. Code should also come with tests for the testsuite.
- Pure code should also come with QuickCheck properties.
- Impure code should have unit tests.
- Portability. Code should be portable. If it is not portable, reasons should be given. Ensure the code runs in at least Hugs and GHC, Windows and Linux.
Submitting the proposal
- Tracking. Add a Trac ticket of type proposal for the appropriate library component, with a timescale for consideration (to focus the community's attention).
- Submission. Create a darcs patch of the library sources using darcs record, including the Trac ticket number and a rationale, and submit the patch to firstname.lastname@example.org. (You can do this with darcs send.)
Here are the proposals currently under consideration.
At the end of the discussion period
- The proposer adds to the ticket a summary of the relevant parts of the discussion. (The summary is needed for anyone wondering about the change later: it's not reasonable to point people at a 50-message thread.)
- If consensus was achieved, the change is made, with the commit message referring back to the ticket.
- The ticket is closed (usually as fixed or wontfix).
A deeply held disagreement at this point may require some form of government (voting, dictatorship, etc). This should be a rare event.
Here are the archived past proposals.
- GHC Working Conventions, including guidelines for submitting patches via darcs.
- Notes on programming style