Tool Demonstration: An IDE for Programming and Proving in Idris

Dependently typed programming languages have a rich type system, which enables developers to combine proofs with programs, sometimes even eroding the boundary between the activities of proving and programming. This introduces new challenges for integrated development environments that must support this boundary. Instead of reimplementing large parts of a compiler, such as a type checker and a totality checker, we extended the Idris compiler with a structured, machine-readable protocol for interacting with other programs. Furthermore, we developed an IDE for Idris in Emacs, which uses this structured input and output mode, that attempts to combine features from both proof assistant interfaces and rich programming environments such as SLIME. The Idris extension turned out to be generally useful, and has been used in applications such as an IRC bot, an interactive website for trying out Idris, and support for other editors.