[Haskell-beginners] problem with type
morel.pisum at googlemail.com
Sun Jun 17 09:08:06 CEST 2012
What you want is probably
checkNode :: String -> [String] -> Bool
checkNode s nodes = and (map (==s) nodes)
which returns True iff all nodes equal s.
> Am a bit stuck here,... please, what is wrong with this?
> checkNode :: String -> [String] -> Bool
> checkNode s nodes =
> [s == node | node <- nodes ]
> Couldn't match expected type `Bool' with actual type `[t0]'
> [1 of 1] Compiling Main ( src/me.hs, interpreted )
> In the expression: [s == node | node <- nodes]
> Failed, modules loaded: none.
> In an equation for `checkNode':
> checkNode s nodes = [s == node | node <- nodes]
More information about the Beginners