A total recursion scheme library for Dhall
A total recursion scheme library for Dhall
Recursion schemes allow you to separate recursion from your business logic – making your own operations simpler, more modular, and less error-prone. This library also provides tools for combining your operations in ways that reduce the number of passes over your data and is designed to encourage total (that is, successfully terminating) functions.
API docs are on GitHub Pages.
We recommend the following steps to make working in this repository as easy as possible.
direnv allow
This command ensures that any work you do within this repository happens within a consistent reproducible environment. That environment provides various debugging tools, etc. When you leave this directory, you will leave that environment behind, so it doesn’t impact anything else on your system.
git config --local include.path ../.cache/git/config
This will apply our repository-specific Git configuration to git
commands run against this repository. It’s lightweight (you should definitely look at it before applying this command) – it does things like telling git blame
to ignore formatting-only commits.
Especially if you are unfamiliar with the Dhall or Haskell ecosystems, there is a Nix build (both with and without a flake). If you are unfamiliar with Nix, Nix adjacent can help you get things working in the shortest time and least effort possible.
nix
installednix build
will build and test the project fully.
nix develop
will put you into an environment where the traditional build tooling works. If you also have direnv
installed, then you should automatically be in that environment when you're in a directory in this project.
The Haskell part of this project is built with Cabal. Individual packages will work with older versions, but ./cabal.package requires Cabal 3.6+.
In the absolute, almost every change is a breaking change. This section describes how we mitigate that to offer minor updates and revisions.
Here are some common Haskell changes that can have unintended effects:
To mitigate some of those issues for versioning, we assume the following usage:
PackageImports
, so that adding modules is a minor change;-Werror
can cause this to fail, but published libraries shouldn't be compiled with -Werror
.Other projects similar to this one, and how they differ.