[Haskell-cafe] ErrorT and catchError question

Adam Smyczek adam.smyczek at gmail.com
Tue Jan 15 00:28:20 EST 2008


I'm trying to use ErrorT transformer based
on Don Stewart's Shell example:
It's probably a trivial question, but I cannot figure out
how to implement the catchError function in:

instance MonadError String Shell where
	throwError      = error . ("Shell failed: "++)
	catchError l h = ???

Thanks for help,

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