Add comment about slightly incorrect error message

2021-11-18 13:50:21 +01:00 · 2021-11-18 13:50:21 +01:00 · 75cb9ac246
parent aab7e0d5dd
commit 75cb9ac246
1 changed files with 4 additions and 0 deletions
--- a/servant-server/src/Servant/Server/Internal.hs
+++ b/servant-server/src/Servant/Server/Internal.hs
@ -859,6 +859,10 @@ type HasServerArrowTypeError a b =
    ':$$: 'ShowType b

 -- Erroring instances for 'HasServer' for unknown API combinators
+
+-- XXX: This omits the @context@ parameter, e.g.:
+--
+-- "There is no instance for HasServer (Bool :> …)". Do we care ?
 instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub HasServer ty) => HasServer (ty :> sub) context

 instance {-# OVERLAPPABLE #-} TypeError (NoInstanceFor (HasServer api context)) => HasServer api context