A demo implementation of a simple dependently-typed language for OPLSS (Used in 2022, 2014 and 2013)
The goal of this project is to bring up the design issues that occur in the implementation of the type checkers of languages like Agda, Coq, Epigram, Idris, etc. Of course, it can't cover everything, but this code is a starting point for discussion.
As its main purpose is didactic, the code itself has been written for clarity, not for speed. The point of this implementation is an introduction to practical issues of language design and how specific features interact with each other.
Compiling pi-forall requires GHC and stack
Recommended tools (see links for instructions):
The gchup tool is an installer for general purpose Haskell tools, including GHC, Cabal, Stack and the Haskell language server (HLS). You'll want to install the recommended versions of all of these tools.
There are several versions of pi-forall in the repository. See the
documentation for an extended description of what parts of the language
are covered by each version.
Each implementation has the following structure:
<version>/
pi/*.pi example pi-forall files
src/*.hs source code
app/Main.hs entry point
README.md (this file)
LICENSE
pi-forall.cabal
stack.yaml
To build each version, go to that directory and type:
stack build
and to typecheck a source file:
stack exec -- pi-forall <sourcefile>
Some of this code was adapted from the 'zombie-trellys' implementation by the Trellys team. The Trellys team includes Aaron Stump, Tim Sheard, Stephanie Weirich, Garrin Kimmell, Harley D. Eades III, Peng Fu, Chris Casinghino, Vilhelm Sjöberg, Nathan Collins, and Ki Yung Ahn.
This material is based upon work supported by the National Science Foundation under Grant Number 0910786. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.