Many changes, including bug fixes and documentation improvements can be implemented and reviewed via the normal GitHub pull request workflow.
Some changes though are "substantial", and we ask that these be put through a bit of a design process and produce a consensus among the Pony community and committers.
The "RFC" (request for comments) process is intended to provide a consistent and controlled path for new features to enter the language and standard libraries, so that all stakeholders can be confident about the direction the language is evolving in.
You need to follow this process if you intend to make "substantial" changes to Pony. What constitutes a "substantial" change is evolving based on community norms and varies depending on what part of the ecosystem you are proposing to change, but may include the following.
Some changes do not require an RFC:
What is a bugfix?
Bugfixes do not have to go through the RFC process. The definition of "bugfix" is still evolving. Some things we consider to be bug fixes:
As we move forward, we will add more rules to our list of "items that don't need an RFC". If there is doubt about whether a change/addition requires an RFC, the issue will be resolved by a quorum vote of active committers to the project.
If you submit a pull request to implement a new feature without going through the RFC process, it may be closed with a polite request to submit an RFC first. If you believe that your PR falls under one the exemptions above, please raise that in the initial PR.
A hastily-proposed RFC can hurt its chances of acceptance. Low quality proposals, proposals for previously-rejected features, or those that don't fit into the near-term roadmap, may be quickly rejected, which can be demotivating for the unprepared contributor. Laying some groundwork ahead of the RFC can make the process smoother.
Although there is no single way to prepare for submitting an RFC, it is generally a good idea to pursue feedback from other project developers beforehand, to ascertain that the RFC may be desirable: having a consistent impact on the project requires concerted effort toward consensus-building.
The most common preparations for writing and submitting an RFC include talking the idea over at the weekly Pony sync meeting or discussing on the pony+dev mailing.
As a rule of thumb, receiving encouraging feedback from long-standing project developers.
In short, to get a major feature added to Pony, one must first get the RFC merged into the RFC repo as a markdown file. At that point the RFC is 'active' and may be implemented with the goal of eventual inclusion into Pony.
text/0000-my-feature.md(where 'my-feature' is descriptive. don't assign an RFC number yet).
Once an RFC becomes active then authors may implement it and submit the feature as a pull request to the Pony repo. Being 'active' is not a rubber stamp, and in particular still does not mean the feature will ultimately be merged; it does mean that in principle all the major stakeholders have agreed to the feature and are amenable to merging it.
Furthermore, the fact that a given RFC has been accepted and is 'active' implies nothing about what priority is assigned to its implementation, nor does it imply anything about whether a Pony developer has been assigned the task of implementing the feature. While it is not necessary that the author of the RFC also write the implementation, it is by far the most effective way to see an RFC through to completion: authors should not expect that other project developers will take on responsibility for implementing their accepted feature.
Modifications to active RFC's can be done in follow-up PR's. We strive to write each RFC in a manner that it will reflect the final design of the feature; but the nature of the process means that we cannot expect every merged RFC to actually reflect what the end result will be at the time of the next major release.
In general, once accepted, RFCs should not be substantially changed. Only very minor changes should be submitted as amendments. More substantial changes should be new RFCs, with a note added to the original RFC. Exactly what counts as a "very minor change" is up to the committers to decide.
While the RFC PR is up, we may schedule meetings with the author and/or relevant stakeholders to discuss the issues in greater detail. A summary from the meeting will be posted back to the RFC pull request.
We will make final decisions about RFCs after the benefits and drawbacks are well understood. These decisions can be made at any time. When a decision is made, the RFC PR will either be merged or closed.
Some accepted RFC's represent vital features that need to be implemented right away. Other accepted RFC's can represent features that can wait until some arbitrary developer feels like doing the work. Every accepted RFC has an associated issue tracking its implementation in the Pony repository; thus that associated issue can be assigned a priority via the triage process that the team uses for all issues in the Pony repository.
The author of an RFC is not obligated to implement it. Of course, the RFC author (like any other developer) is welcome to post an implementation for review after the RFC has been accepted.
If you are interested in working on the implementation for an 'active' RFC, but cannot determine if someone else is already working on it, feel free to ask (e.g. by leaving a comment on the associated issue).