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{-# LANGUAGE BangPatterns #-}
module Data.MinMaxPSQ where
import Data.Ord
import qualified Data.Wrapper.PSQ as PSQ
;import Data.Wrapper.PSQ as PSQ hiding (insert, insert', null, size)
import Prelude hiding (null, take)
data MinMaxPSQ' k p v = MinMaxPSQ !(PSQ' k p v) !(PSQ' k (Down p) v)
type MinMaxPSQ k p = MinMaxPSQ' k p ()
empty :: MinMaxPSQ' k p v
empty = MinMaxPSQ PSQ.empty PSQ.empty
null :: MinMaxPSQ' k p v -> Bool
null (MinMaxPSQ nq xq) = PSQ.null nq
size :: MinMaxPSQ' k p v -> Int
size (MinMaxPSQ nq xq) = PSQ.size nq
toList :: (PSQKey k, Ord p) => MinMaxPSQ' k p v -> [Binding' k p v]
toList (MinMaxPSQ nq xq) = PSQ.toList nq
fromList :: (PSQKey k, Ord p) => [Binding' k p v] -> MinMaxPSQ' k p v
fromList kps = MinMaxPSQ (PSQ.fromList kps)
(PSQ.fromList $ map (\(Binding k v p) -> Binding k v (Down p)) kps)
findMin :: (PSQKey k, Ord p) => MinMaxPSQ' k p v -> Maybe (Binding' k p v)
findMin (MinMaxPSQ nq xq) = PSQ.findMin nq
findMax :: (PSQKey k, Ord p) => MinMaxPSQ' k p v -> Maybe (Binding' k p v)
findMax (MinMaxPSQ nq xq) = fmap (\(Binding k v (Down p)) -> Binding k v p) $ PSQ.findMin xq
insert :: (PSQKey k, Ord p) => k -> p -> MinMaxPSQ k p -> MinMaxPSQ k p
insert k p (MinMaxPSQ nq xq) = MinMaxPSQ (PSQ.insert k p nq)
(PSQ.insert k (Down p) xq)
insert' :: (PSQKey k, Ord p) => k -> v -> p -> MinMaxPSQ' k p v -> MinMaxPSQ' k p v
insert' k v p (MinMaxPSQ nq xq) = MinMaxPSQ (PSQ.insert' k v p nq)
(PSQ.insert' k v (Down p) xq)
delete :: (PSQKey k, Ord p) => k -> MinMaxPSQ' k p v -> MinMaxPSQ' k p v
delete k (MinMaxPSQ nq xq) = MinMaxPSQ (PSQ.delete k nq) (PSQ.delete k xq)
deleteMin :: (PSQKey k, Ord p) => MinMaxPSQ' k p v -> MinMaxPSQ' k p v
deleteMin (MinMaxPSQ nq xq) = case PSQ.minView nq of
Just (Binding k _ _, nq') -> MinMaxPSQ nq' (PSQ.delete k xq)
Nothing -> MinMaxPSQ nq xq
deleteMax :: (PSQKey k, Ord p) => MinMaxPSQ' k p v -> MinMaxPSQ' k p v
deleteMax (MinMaxPSQ nq xq) = case PSQ.minView xq of
Just (Binding k _ _, xq') -> MinMaxPSQ (PSQ.delete k nq) xq'
Nothing -> MinMaxPSQ nq xq
minView :: (PSQKey k, Ord p) => MinMaxPSQ' k p v -> Maybe (Binding' k p v, MinMaxPSQ' k p v)
minView (MinMaxPSQ nq xq) = fmap (\(Binding k v p, nq') -> (Binding k v p, MinMaxPSQ nq' (PSQ.delete k xq)))
$ PSQ.minView nq
maxView :: (PSQKey k, Ord p) => MinMaxPSQ' k p v -> Maybe (Binding' k p v, MinMaxPSQ' k p v)
maxView (MinMaxPSQ nq xq) = fmap (\(Binding k v (Down p), xq') -> (Binding k v p, MinMaxPSQ (PSQ.delete k nq) xq'))
$ PSQ.minView xq
-- | Maintains a bounded 'MinMaxPSQ' by deleting the maximum element if the
-- insertion would cause the queue to have too many elements.
insertTake :: (PSQKey k, Ord p) => Int -> k -> p -> MinMaxPSQ k p -> MinMaxPSQ k p
insertTake n k p q = take n $ insert k p q
-- | Maintains a bounded 'MinMaxPSQ\'' by deleting the maximum element if the
-- insertion would cause the queue to have too many elements.
insertTake' :: (PSQKey k, Ord p) => Int -> k -> v -> p -> MinMaxPSQ' k p v -> MinMaxPSQ' k p v
insertTake' n k v p q = take n $ insert' k v p q
-- | Truncate the 'MinMaxPSQ' to the given number of lowest priority elements.
take :: (PSQKey k, Ord p) => Int -> MinMaxPSQ' k p v -> MinMaxPSQ' k p v
take !n !q | (size q <= n) = q
| null q = q
| otherwise = take n $ deleteMax q
|
