[Haskell-cafe] Re: Haddock: Documentation of instances with un-documentable type arguments

[Johannes Waldmann]

> In this case, the class is one defined inside that module and used
> solely for those two data types; it isn't exported, and the only way
> you can tell it exists is that Haddock mentions the instances.

OK. 

I was confused because the text of the posting
mentioned MonadReader and MonadState (and their methods set/get/ask/...), 
which are globally known.

J.W.