27 Dec
                
                    2007
                
            
            
                27 Dec
                
                '07
                
            
            
            
        
    
                9:59 a.m.
            
        Simon Peyton-Jones wrote:
As others have pointed out, GHC allows you to put a context on any data constructor. I prefer this "where" syntax:
But, in 6.8.x, you will need -XGADTS to permit this. 6.6.x permitted it anyway, arguably in error. http://hackage.haskell.org/trac/ghc/ticket/1901 Jules