Idris2-boot/CONTRIBUTING.md

Contributing to Idris 2

Contributions are welcome! The most important things needed at this stage, beyond work on the language core, are (in no particular order):

• CI integration.
• Documentation string support (at the REPL and IDE mode).
• A better REPL, including:
  • readline and tab completion
  • :search and :apropos
  • help commands
• Further library support (please add initially into contrib/)
• Partial evaluation, especially for specialisation of interface implementations.
• An alternative, high performance, back end. OCaml seems worth a try.
• JS and Node back ends would be nice.

Some language extensions from Idris 1 have not yet been implemented. Most notably:

• Type providers
  • Perhaps consider safety - do we allow arbitrary IO operations, or is there a way to restrict them so that they can't, for example, delete files or run executables.
• Elaborator reflection
  • This will necessarily be slightly different from Idris 1 since the elaborator works differently. It would also be nice to extend it with libraries and perhaps syntax for deriving implementations of interfaces.

Other contributions are also welcome, but I (@edwinb) will need to be confident that I'll be able to maintain them!

Some syntax that hasn't yet been implemented but will be:

• Range syntax (e.g. [1..10], [1,3..10], [1..] etc) [needs some thought about what should go in the Prelude and exactly how to implement]
• Idiom brackets
• !-notation [needs some thought about the exact rules]

Some things from Idris 1 definitely won't be implemented:

• Uniqueness types (instead, Idris 2 is based on QTT and supports linearity)
• Some esoteric syntax experiments, such as match applications
• Syntax extensions (at least in the unrestricted form from Idris 1)
• DSL blocks (probably) unless someone has a compelling use case that can't be done another way