Re: Encountered absent arg

2010-04-07 Thread Max Bolingbroke
On 7 April 2010 00:23, Louis Wasserman wasserman.lo...@gmail.com wrote: biggest sources of angst!)  Looking at ghc-core, my code appears to always give the exception Oops!  Entered absent arg ww_s9eC{v} [lid] predmain:Data.Algebra.Ring.Ring{tc r2tU} c{tv a8Os} [tv] Is this typical?  Where

Deriving regression or bad code?

2010-04-07 Thread Ron Alford
I've attached the simplest example of my code that used to compile in GHC 6.10 now gives the error in GHC 6.12.1: baddata.hs:33:14: No instances for (Data Const, Data Var) arising from the 'deriving' clause of a data type declaration at baddata.hs:33:14-17 Possible