how-to-add-a-new-trait.md

How-to: add a new trait

This is the suggested approach to adding a new trait to embedded-hal

Research / Discussion

Ideally, before proposing a new trait, or set of traits, you should check for an existing issue suggesting the need for the trait, as well as any related works / use cases / requirements that are useful to consider in the design of the trait.

These issues will be labeled as discussion in the issue tracker.

Implementation / Demonstration

Proposed traits should then be implemented and demonstrated, either by forking embedded-hal or by creating a new crate with the intent of integrating this into embedded-hal once the traits have stabilized. You may find cargo workspaces and patch useful for the forking approach.

Traits should be demonstrated with at least two implementations on different platforms and one generic driver built on the trait. Where it is possible we suggest an implementation on a microcontroller, and implementation for linux, and a driver (or drivers where requirements are more complex) with bounds using the trait.

Proposing a trait

Once the trait has been demonstrated a PR should be opened to merge the new trait(s) into embedded-hal. This should include a link to the previous discussion issue.

If there is determined to be more than one alternative then there should be further discussion to try to single out the best option. Once there is consensus this will be merged into the embedded-hal repository.

These issues / PRs will be labeled as proposals in the issue tracker.