On 11 January 2005 17:35, Ross Paterson wrote:

To re-iterate an old suggestion: how about using a custom data type like

data ParseResult a = ParseFailed PError | ParseOk a

instead of Either for parse results, thus removing the dependency on mtl, which will help with bootstrapping. I know there is Distribution.Compat.Error, but that defines a Monad instance for Either, so if one uses that there'll be trouble later if some program includes both Cabal and mtl.

Go for it... I'll fix up anything that depends on it in GHC. Cheers, Simon