Hello Brian, Thursday, January 4, 2007, 10:00:05 PM, you wrote:
deeper, the programmer is burdened more and more by the need to cut-and-paste method definitions between instances because Haskell doesn't allow a superclass (or ancestor class) method default to be redefined in a subclass.
i've runned into this problem with Streams library. finally i've decided to wrote bodies of such methods outside of class: getLineBody :: (CharStream h) => h -> IO String getLineBody h = do c <- getChar .... instance LineStream File where getLine = getLineBody instance LineStream MemBuf where getLine = getLineBody where File and MemBuf, of course, are CharStream instances -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com