Re: Concrete syntax for pattern synonym type signatures

On Sat, 8 Nov 2014, Richard Eisenberg wrote:

On Nov 8, 2014, at 11:23 AM, "Dr. ERDI Gergo" wrote:

...

So we would need to add a way of parsing (T1, T2, ..., Tn; U1, U2, ..., Um) into a type, which would then require rejecting everywhere else where we really do mean a type... Sounds painful. Also painful: rewriting the whole context parsing code :/

I actually think this wouldn't be all that hard. The same parse-as-wrong-AST-node-and-then-fix-it-up-later trick happens in plenty of places, patterns (parsed as expressions) being one of the biggest. Harder than my proposal, probably, but I don't think it's terrible.

Right, but the issue in this case is if we add this artifical constructor to HsType just so we can fix it up into a pair of contexts, this constructor would permeate everything else that has to do with HsTypes; if nothing else, it'd need a `panic "foo: HsContextPair"` branch for all type-related renamer/typechecker functions. Unless I'm missing some shortcut. I hope I do! Bye, Gergo