FastString's Show instance might prove problematic for DataKinds's Haddock representation
Consider the following reproducer:
{- Movie.hs -}
{-# LANGUAGE DataKinds #-}
module Movie where
type Movies = '["借りぐらしのアリエッティ", "海猿" ]
The following Haddock invocation haddock --html Movie.hs
gives us the following representation:
This ticket conversation by @Fuuzetsu and @alexbiehl seem to point that the culprit would be FastString
's Show
instance, defined as:
instance Show FastString where
show fs = show (unpackFS fs)
and the pprIfaceTyLit
function that uses show
.
This is a direct consequence of the mechanisms at play described in CLC Proposal #26.
Where can we go from here?