Simon Marlow simonmar at microsoft.com
Wed Jan 12 08:14:45 EST 2005

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.


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