Re: Reify and separating renamer+TH from type-checking

FYI, metaocaml runs into the same problem [for different reasons]. There the design decision was to not allow using a data-type in the same file as its definition. Separate compilation then solves the problem. This is a minor pain. But in Haskell, this would lead to orphan instances when using TH to derive instances, which is likely to be thought of as a rather bigger pain. Jacques On 2016-01-08 6:08 PM, Simon Peyton Jones wrote:

Bother. That's true. And it's a vital feature. Otherwise how do we do

data T = T1 | T2 $(makeLenses 'T)

So we can't separate the two after all. Sorry -- I totally forgot about that. Very annoying.

Simon

| -----Original Message----- | From: Edward Z. Yang [mailto:ezyang@mit.edu] | Sent: 08 January 2016 19:40 | To: Simon Peyton Jones | Cc: ghc-devs | Subject: Reify and separating renamer+TH from type-checking | | I implemented the refactoring to run the renamer and TH splices all | first before doing any type-checking, but actually there's a problem: | Template Haskell splices can call 'reify', which needs the type | information in order to supply the information about the identifiers | in question. I can't think of any good way around this problem. | | Edward _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs