tvl-depot/buildHaskell/default.nix
William Carroll 4ea55dd013 Support buildHaskell
Use Nix and Briefcase to easily create Haskell executables.

I'd eventually like to support something like: briefcase.buildHaskell.project
that let me define a few top-level values (e.g. ghcExtensions) and would give me
a ghci environment with the proper `.ghci` settings so that my development
environment mirrored my build environment... baby steps, though.
2020-08-12 16:26:17 +01:00

31 lines
1 KiB
Nix

{ pkgs, ... }:
{
# Create a nix-shell for Haskell development.
shell = { deps }: let
ghc = pkgs.haskellPackages.ghcWithPackages (hpkgs: deps hpkgs);
in pkgs.mkShell {
buildInputs = [ghc];
};
# Build a Haskell executable. This assumes a project directory with a
# top-level Main.hs. It also applies a few commonly used language extensions.
# Here is an overview of the arguments:
# - `name`: You can find the result at ./result/$name
# - `srcs`: Will be passed to `srcs` field of `pkgs.stdenv.mkDerivation`.
# - `deps`: A function that accepts `hpkgs` and returns a list of Haskell
# dependencies.
program = { name, srcs, deps, ghcExtensions }: let
ghc = pkgs.haskellPackages.ghcWithPackages (hpkgs: deps hpkgs);
in pkgs.stdenv.mkDerivation {
name = name;
buildInputs = [];
srcs = srcs;
buildPhase = ''
${ghc}/bin/ghc -Wall Main.hs ${pkgs.lib.concatMapStrings (x: "-X${x} ") ghcExtensions}
'';
installPhase = ''
mkdir -p $out && mv Main $out/${name}
'';
};
}