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) in packages that list email@example.com as maintainer. We have been using it since October 2006.
In essence, we don't want proposals to go unnoticed, but changes to basic interfaces also need thorough consideration.
Creating a proposal
In order to ensure we have something concrete to discuss, please follow the following guidelines:
- Currency. Make your changes against a copy of the HEAD branch of the relevant library, and make sure it compiles.
- Portability. Code should be portable. If it is not portable, reasons should be given. At the very least ensure the code runs in Hugs and GHC, and on Windows and Linux.
- Style. Follow the conventions in the library you are modifying.
- Documentation. It must include valid Haddock documentation.
- Tests. Code should ideally also come with suitable tests for the testsuite. There's currently some disagreement about what this means. Discussion of where we may want to head is in the library tests page.
Submitting the proposal
- Patch. Create a darcs patch of your change using darcs record, including a rationale for the change. Save the patch to a file, using darcs send --output.
- Tracking. Add a Trac ticket of type proposal for the appropriate library component, with a timescale for consideration (to focus the community's attention for a limited period), adding the patch file as an attachment.
- Submission. Send an email containing the Trac ticket number and description to firstname.lastname@example.org, which you need to subscribe before posting. (In the future this should happen when you record the ticket, but we haven't set it up yet.) You may wish to include a pointer to updated Haddock documentation, if relevant.
If someone has done all this, they are entitled to expect feedback; silence during the discussion period can be interpreted as consent.
Here are the proposals currently under consideration.
At the end of the discussion period
- Add 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 (but please do include a link to the thread in the list archives too, so that people can review it if they wish)).
- If consensus was achieved, revise the patch as necessary, including the Trac ticket number, and commit it (or set the ticket state to "patch" so that someone will commit it for you).
- Close the ticket (usually as fixed or wontfix).
A deeply held disagreement at this point may require some form of governance (voting, dictatorship, etc). This should be a rare event.
Here are the archived past proposals.
Here is an example of how to summarise a successful submission.
- GHC Working Conventions, including guidelines for submitting patches via darcs.
- Notes on programming style