On Fri, 2007-01-26 at 15:40 +0100, Arie Peterson wrote: > Hello, > > > Donald Bruce Stewart wrote: > > > Ok, I forgot one point. It is possible to automatically derive instances > > of Binary for your custom types, if they inhabit Data and Typeable, > > using an SYB trick. Load tools/derive/BinaryDerive.hs into ghci, and > > bring your type into scope, then run: > > > > *Main> mapM_ putStrLn . lines $ derive (undefined :: Drinks) > > It would seem that one needs to rerun the script every time the type is > changed. That would be unfortunate. Perhaps I could have a go at writing a > template haskell function to derive those instances? > > I also fear that the existing script does not handle types with more than > 256 constructors correctly. While uncommon, those are not unrealistic.
Feel free to send in a patch. All it needs to do is check if there are more than 2^8 constructors and if so encode the tag in a Word16 rather than Word8. Duncan _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
