flake.nix

   1 {
   2 # Reuse any local nixpkgs, at cost of reproductibility
   3 #inputs.nixpkgs.url = "flake:nixpkgs";
   4 # Can be overriden by passing --override-input nixpkgs flake:nixpkgs to nix
   5 inputs.nixpkgs.url = "github:NixOS/nixpkgs/8585991bfb629edda1e42c191bef935d9d70d690";
   6 inputs.flake-utils.url = "github:numtide/flake-utils";
   7 outputs = inputs: inputs.flake-utils.lib.eachDefaultSystem (system: let
   8   pkgs = inputs.nixpkgs.legacyPackages.${system};
   9   ghc = null; # Use default ghc, but could have been ghc901
  10   haskellPackages =
  11     if ghc == null
  12     then pkgs.haskellPackages
  13     else pkgs.haskell.packages.${ghc};
  14   hs = haskellPackages.extend (with pkgs.haskell.lib; hfinal: hprev: {
  15     "AoC202004" = hfinal.callCabal2nix "AoC2020" ./Day04 {};
  16   });
  17   in rec {
  18     devShell = hs.shellFor {
  19       packages = p: [ p."AoC202004" ];
  20       withHoogle = false;
  21       nativeBuildInputs = [
  22         hs.cabal-install
  23         hs.haskell-language-server
  24         #hs.hpc
  25       ];
  26       buildInputs = [
  27         #hs.ghcid
  28         #hs.ormolu
  29         #hs.hlint
  30         #pkgs.nixpkgs-fmt
  31       ];
  32     };
  33     packages = {
  34       "Day04" = hs."AoC202004";
  35     };
  36     defaultApp = {
  37       type = "app";
  38       program = (pkgs.writeShellScript "run" ''
  39         cd ${inputs.self}
  40         ${pkgs.gnumake}/bin/make run
  41       '').outPath;
  42     };
  43     apps = pkgs.lib.genAttrs [
  44         "Day04"
  45       ] (day: {
  46         type = "app";
  47         program = "${packages.Day04}/bin/Day";
  48       }
  49     );
  50   }
  51 );
  52 }