The issue you had with applications of the [] type seems to be more
insidious than my last email made it out to be. This expression
( $(return $ ConE (mkName "[]")) ::
$(return $ ConT (mkName "[]") `AppT` ConT ''Char)
)
fails with "[] is applied to too many arguments". I'm thinking that
the "[]" in the type is being resolved somehow to the the [] data
constructor, not the [] type constructor.
This seems specific to []; the following works for tuples, even though
the data and type constructor also share a string name.
$(return $ ConE (mkName "(,)") `AppE` LitE (CharL 'c') `AppE` LitE
(CharL 'a')) ::
$(return $ ConT (mkName "(,)") `AppT` ConT ''Char `AppT` ConT ''Char)
I haven't yet narrowed down where the mkName'd string is
(inappropriately?) resolved in the GHC source.
Eric, special-casing for ArrowT probably avoids this problem for you.
The only thing to glean from this email is that you ideally wouldn't
need to worry about the special-casing for your current application —
I think there's a TH bug at play, though I haven't found an open GHC
ticket for it and it may very well still be a known issue.
On Sun, Oct 7, 2012 at 10:15 AM, Eric M. Pashman
Nicolas, thanks for the welcome, and thanks for pointing out the additional 'Type' constructors!
I'd looked over the available constructors, but apparently not very well. The 'ListT', 'TupleT', 'ArrowT', etc., constructors are precisely what I need to make this work in a straightforward fashion.
So I don't actually have a problem making the right 'Name' value, just a problem reading the TH source. Well, that's that. ...
Many thanks,
Eric
My pleasure. However,