[Haskell-cafe] csv one-liner

[Derek Elkins]

On Wed, 2008-10-01 at 10:15 +0200, Ketil Malde wrote:
> Derek Elkins <derek.a.elkins at gmail.com> writes:
> 
> >> parseCSVFromFile "in.csv" >>= return . either (const "error!")
> 
> > Whenever you see this >>= return . f pattern think liftM or fmap or <$>.
> 
> ...and "return . f >>= action" is just "action . f", no?


Well actually that's \x -> action (return (f x)) x via the (r ->)
instance of Monad.  I think what you wanted was
\x -> return (f x) >>= action which is
\x -> action (f x)
action . f via the monad laws.