modernize build system

1 files changed, 31 insertions, 0 deletions

diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..48d4bf4
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,31 @@
+{ compiler ? "default"
+, nixpkgs ? import <nixpkgs> {}
+}: let
+
+  inherit (nixpkgs) lib pkgs;
+
+  haskellPackages =
+    if compiler == "default" then
+      pkgs.haskellPackages
+    else
+      pkgs.haskell.packages.${compiler};
+
+  drv = haskellPackages.callPackage (import ./package.nix) {};
+
+in
+
+  lib.overrideDerivation drv.env (oldAttrs: {
+    buildInputs = [
+      pkgs.cabal-install
+    ];
+    shellHook = ''
+      CABAL_BUILD_DIR=$HOME/tmp/cache/${drv.pname}
+      cabal() {
+        command=$1; shift
+        ${pkgs.cabal-install}/bin/cabal \
+            "$command" \
+            --builddir="$CABAL_BUILD_DIR" \
+            "$@"
+      }
+    '';
+  })