[Haskell-cafe] ErrorT vs Either

Gracjan Polak gracjanpolak at gmail.com
Mon May 16 22:56:25 CEST 2011


Hi all,

A why question: Why:

Control.Monad.Error Prelude> runErrorT (fail "msg") :: IO (Either String Int)
Left "msg"

but

Control.Monad.Error Prelude> (fail "msg") :: (Either String Int)
*** Exception: msg

?

-- 
Gracjan





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