On Sep 15, 2013, at 5:44 PM, Joachim Breitner
not really; if you type ":info Coercible" you see that there are no instances created. Just the type-checking of uses of coerce is a bit special.
Even stranger, I think. I understand that there aren't really any instances of Coercible, but it certainly looks like there is, to users.
foo :: Coercible a b => a -> b -> () foo = undefined bar = foo 'a' 'b'
will certainly compile. For an ordinary class, that would mean that we should expect Coercible Char Char to exist (or perhaps Coercible a a, or something similar). But it won't. This would appear to be quite strange. To be clear, I'm not asking for an explanation for me -- I think I know what's going on here. I just think that this behavior requires a small section in the user manual, because it's a user-visible change to the language that GHC compiles. I would say the haddock docs could point to the user manual, to avoid the duplication (which I similarly dislike, for sure!) Richard
I think the question is rather: Where would the user search for documentation. And given that there are identifiers related to the feature (Coercible, coercion), the haddocks for that are the natural place to search. And as I’d like to avoid duplication, I’d not put the docs somewhere else again.
I don’t mind adding a pointer from the “Special built-in functions” section to the haddock docs, though, if you think it would be helpful.
Greetings, Joachim -- Joachim Breitner e-Mail: mail@joachim-breitner.de Homepage: http://www.joachim-breitner.de ICQ#: 74513189 Jabber-ID: nomeata@joachim-breitner.de _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://www.haskell.org/mailman/listinfo/ghc-devs