From 14fe4c4d6b5a29be94ecfc0572e0f9a9a081e795 Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Mon, 30 Apr 2018 09:03:46 -0400 Subject: fix broken SemigroupMonoid transition <> Turns out that with ghc 8.2.2, the instructions given on the page don't work. And the cppless variant that I had compiles, but into effectively mappend = mappend so it loops. The only way I can see to make it work without cpp is to use mappend = (Sem.<>) which is ugly and a land mine waiting to explode if someone changes it to a nicer mappend = (<>) with a newer version of ghc which will compile it and work ok, while breaking it with 8.2.2. Sigh. I posted to haskell-cafe about this. --- src/Propellor/Types/Core.hs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/Propellor/Types/Core.hs') diff --git a/src/Propellor/Types/Core.hs b/src/Propellor/Types/Core.hs index cd3e09c5..88c749b3 100644 --- a/src/Propellor/Types/Core.hs +++ b/src/Propellor/Types/Core.hs @@ -62,7 +62,7 @@ instance Sem.Semigroup (Propellor Result) where instance Monoid (Propellor Result) where mempty = return NoChange - mappend = (<>) + mappend = (Sem.<>) -- | An action that Propellor runs at the end, after trying to satisfy all -- properties. It's passed the combined Result of the entire Propellor run. -- cgit v1.2.3