Bertram,
Oh I see. The items passed to the devName’ constructor must be constructors too.
I guess I did not think of that way. I thought of them as filling holes in constructor, thus values.
Too much OO in my past :-(
I’m slowly rebuilding those old neurons into something better.
Mike
On Mar 12, 2015, at 5:05 AM, Bertram Felgenhauer
Dear Michael,
Michael Jones wrote:
I’m stuck getting a TH expansion to compile. When I take the generated code and compile it directly, it is fine. But when expanding and compiling, it fails.
The problem seems related to instanceD, where I provide the type as:
(appT (appT (conT devName') (varT $ mkName "Word8")) (varT $ mkName "BV”))
[...]
Illegal type variable name: ‘BV’
Indeed BV is the name of a type *constructor*, not a type *variable*, so you need to use `conT` instead of `varT`:
(appT (appT (conT devName') (conT $ mkName "Word8")) (conT $ mkName "BV”))
HTH,
Bertram _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe