Haskell
Introduction
Nix recipes for Haskellers aims to get a beginner comfortable managing simple Haskell programs and projects using Nix.
Scripting
Here's an example using nix-shell to get a redistributable Haskell script that you can run on any Nix system with `./my-script.hs`:
#!/usr/bin/env nix-shell #!nix-shell --pure -i runghc -p "haskellPackages.ghcWithPackages (pkgs: [ pkgs.turtle ])" main = do # do stuff putStrLn "Hello world from a distributable Haskell script!"
FAQ
Limitations
When using cabal2nix
, Nix does not pull a cabal package by respecting the constraint specified in the cabal file (see example). Issue is discussed here. You should be using `callCabal2nix` anyway.
IFD and Haskell
callCabal2nix
, which is implicitly used for building Haskell projects, uses IFD.[1][2]. This means that since IFD is disabled by default in certain nix commands,[3] the following commands will be broken for Haskell projects whose flake output specifies multiple system attributes:
nix flake show
nix flake check