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|
module Grasp.Types.IP (
IP,
singleton,
empty,
isEmpty,
peek,
push,
pop,
shift,
toList
) where
import Grasp.Graph( Node )
newtype IP = IP [Node]
deriving (Eq, Show)
singleton :: Node -> IP
singleton n = IP [n]
empty :: IP
empty = IP []
isEmpty :: IP -> Bool
isEmpty (IP p) = (length p == 0)
peek :: IP -> Maybe Node
peek (IP p) = if (length p == 0) then Nothing else Just (head p)
push :: Node -> IP -> IP
push n (IP p) = IP (n:p)
pop :: IP -> IP
pop (IP p) = if (length p == 0) then empty else IP (tail p)
shift :: Node -> IP -> IP
shift n (IP p) = if (length p == 0) then empty else IP (n:(tail p))
toList :: IP -> [Node]
toList (IP p) = p
|
