On Thu, Mar 13, 2014 at 7:18 AM, Thomas Winant
However, we have the impression that no Hole should remain unfilled, whereas using a partial type signature doesn't necessarily mean the program is incomplete. A partial type signature can still be a (stylistic) choice.
Yes, this is the main hold up I was thinking of. Thinking about it a little more, one way to resolve it perhaps would be to do something similar to we did to typed holes at the term level: make 'holes' at the type level an error by default, which when encountered spit out the error containing the type each hole was instantiated to, and what the partial type signatures would be inferred as. Then, if you enable -XPartialTypeSignatures, these would cease to be errors providing the compiler can infer the types sensibly (and it wouldn't alert you in that case). That might be a half baked idea (I just sat here for about 5 minutes), but either way I say again I do support -XPartialTypeSignatures anyway, and it sounds like a step in the right direction. :) -- Regards, Austin Seipp, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/