Unused variable warnings when deriving (Data)

[Simon Peyton-Jones]

Good point. I've fixed this.

Simon

| -----Original Message-----
| From: glasgow-haskell-bugs-bounces at haskell.org
[mailto:glasgow-haskell-bugs-
| bounces at haskell.org] On Behalf Of Tomasz Zielonka
| Sent: 27 April 2005 10:09
| To: GHC-bugs
| Subject: Unused variable warnings when deriving (Data)
| 
| Hello!
| 
| When I compile the following module with "ghc -W -c A.hs" I see
several
| unnecessary warning messages:
| 
| $ ghc --version
| The Glorious Glasgow Haskell Compilation System, version 6.4
| $ ghc -no-recomp -W -c A.hs
| 
| <no location info>: Warning: Defined but not used: `k'
| 
| <no location info>: Warning: Defined but not used: `k'
| 
| <no location info>: Warning: Defined but not used: `k'
| 
| Adding parameters to data constructors makes the warnings disappear,
| example:
| data T = A Int | B Char
| 
| ---------------- A.hs -------------------
| 
| {-# OPTIONS -fglasgow-exts #-}
| 
| module A where
| 
| import Data.Generics
| 
| data T = A | B
|     deriving (Typeable, Data)
| 
| -----------------------------------------
| 
| Best regards
| Tomasz
| _______________________________________________
| Glasgow-haskell-bugs mailing list
| Glasgow-haskell-bugs at haskell.org
| http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs