about summary refs log tree commit diff
path: root/haskell-overlay.nix
diff options
context:
space:
mode:
authorGriffin Smith <root@gws.fyi>2019-11-30T03·57-0500
committerGriffin Smith <root@gws.fyi>2019-11-30T03·57-0500
commit7d8ce026a2acc5a4d208110750be188f0ce5591c (patch)
tree7a2fc4080eae2b4c1280977fb0ea25b26b25ce96 /haskell-overlay.nix
parent0abcd8c9581f0017cb2bd59a09e93800ea8f3b1f (diff)
Add DerivingVia newtype for generic arbitrary
Add a newtype, GenericArbitrary, which can be used with -XDerivingVia to
derive Arbitrary instances for types with Generic, via patching
generic-arbitrary to expose the underlying typeclass it uses for
surfacing the type information.
Diffstat (limited to 'haskell-overlay.nix')
-rw-r--r--haskell-overlay.nix7
1 files changed, 7 insertions, 0 deletions
diff --git a/haskell-overlay.nix b/haskell-overlay.nix
new file mode 100644
index 000000000000..90ba35c6af6e
--- /dev/null
+++ b/haskell-overlay.nix
@@ -0,0 +1,7 @@
+{ nixpkgs ? import ./nixpkgs.nix {} }:
+let inherit (nixpkgs) pkgs;
+in self: super: rec {
+  generic-arbitrary = pkgs.haskell.lib.appendPatch
+    super.generic-arbitrary
+    [ ./generic-arbitrary-export-garbitrary.patch ];
+}