On Feb 6, 2008 9:39 AM, Miguel Mitrofanov <[EMAIL PROTECTED]> wrote: > > How can I define this for an arbitrary Monad m? > > Such as Identity?
An arbirtrary monad can't be inverted, however there's Error and ErrorT that provide throwing and catching abilities. I guess your parser is a monad transformer, so *maybe* the solution is to require MonadError from the inner monad. Cheers, -- Felipe. _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
