Remove Control.Parallel*, now in package parallel

[haskell-directory.git] / Data / Set.hs

diff --git a/Data/Set.hs b/Data/Set.hs
index 9eb30a4..04d0100 100644 (file)
--- a/Data/Set.hs
+++ b/Data/Set.hs
@@ -9,10 +9,11 @@
 --
 -- An efficient implementation of sets.
 --
--- This module is intended to be imported @qualified@, to avoid name
--- clashes with "Prelude" functions.  eg.
+-- Since many function names (but not the type name) clash with
+-- "Prelude" names, this module is usually imported @qualified@, e.g.
 --
--- >  import Data.Set as Set
+-- >  import Data.Set (Set)
+-- >  import qualified Data.Set as Set
 --
 -- The implementation of 'Set' is based on /size balanced/ binary trees (or
 -- trees of /bounded balance/) as described by:
@@ -78,6 +79,8 @@ module Data.Set  (
             , deleteMax
             , deleteFindMin
             , deleteFindMax
+            , maxView
+            , minView
 
             -- * Conversion
 
@@ -95,21 +98,6 @@ module Data.Set  (
             , showTree
             , showTreeWith
             , valid
-
-       -- * Old interface, DEPRECATED
-       ,emptySet,       -- :: Set a
-       mkSet,          -- :: Ord a => [a]  -> Set a
-       setToList,      -- :: Set a -> [a] 
-       unitSet,        -- :: a -> Set a
-       elementOf,      -- :: Ord a => a -> Set a -> Bool
-       isEmptySet,     -- :: Set a -> Bool
-       cardinality,    -- :: Set a -> Int
-       unionManySets,  -- :: Ord a => [Set a] -> Set a
-       minusSet,       -- :: Ord a => Set a -> Set a -> Set a
-       mapSet,         -- :: Ord a => (b -> a) -> Set b -> Set a
-       intersect,      -- :: Ord a => Set a -> Set a -> Set a
-       addToSet,       -- :: Ord a => Set a -> a -> Set a
-       delFromSet,     -- :: Ord a => Set a -> a -> Set a
             ) where
 
 import Prelude hiding (filter,foldr,null,map)
@@ -206,8 +194,7 @@ member x t
 
 -- | /O(log n)/. Is the element not in the set?
 notMember :: Ord a => a -> Set a -> Bool
-notMember x t = not $ Data.Set.member x t
-
+notMember x t = not $ member x t
 
 {--------------------------------------------------------------------
   Construction
@@ -353,7 +340,16 @@ hedgeDiff cmplo cmphi t (Bin _ x l r)
   Intersection
 --------------------------------------------------------------------}
 -- | /O(n+m)/. The intersection of two sets.
--- Elements of the result come from the first set.
+-- Elements of the result come from the first set, so for example
+--
+-- > import qualified Data.Set as S
+-- > data AB = A | B deriving Show
+-- > instance Ord AB where compare _ _ = EQ
+-- > instance Eq AB where _ == _ = True
+-- > main = print (S.singleton A `S.intersection` S.singleton B,
+-- >               S.singleton B `S.intersection` S.singleton A)
+--
+-- prints @(fromList [A],fromList [B])@.
 intersection :: Ord a => Set a -> Set a -> Set a
 intersection Tip t = Tip
 intersection t Tip = Tip
@@ -757,6 +753,18 @@ deleteFindMax t
       Bin _ x l r   -> let (xm,r') = deleteFindMax r in (xm,balance x l r')
       Tip           -> (error "Set.deleteFindMax: can not return the maximal element of an empty set", Tip)
 
+-- | /O(log n)/. Retrieves the minimal key of the set, and the set stripped from that element
+-- @fail@s (in the monad) when passed an empty set.
+minView :: Monad m => Set a -> m (a, Set a)
+minView Tip = fail "Set.minView: empty set"
+minView x = return (deleteFindMin x)
+
+-- | /O(log n)/. Retrieves the maximal key of the set, and the set stripped from that element
+-- @fail@s (in the monad) when passed an empty set.
+maxView :: Monad m => Set a -> m (a, Set a)
+maxView Tip = fail "Set.maxView: empty set"
+maxView x = return (deleteFindMax x)
+
 
 {--------------------------------------------------------------------
   [balance x l r] balances two trees with value x.
@@ -1139,72 +1147,3 @@ prop_List :: [Int] -> Bool
 prop_List xs
   = (sort (nub xs) == toList (fromList xs))
 -}
-
-{--------------------------------------------------------------------
-  Old Data.Set compatibility interface
---------------------------------------------------------------------}
-
-{-# DEPRECATED emptySet "Use empty instead" #-}
--- | Obsolete equivalent of 'empty'.
-emptySet :: Set a
-emptySet = empty
-
-{-# DEPRECATED mkSet "Use fromList instead" #-}
--- | Obsolete equivalent of 'fromList'.
-mkSet :: Ord a => [a]  -> Set a
-mkSet = fromList
-
-{-# DEPRECATED setToList "Use elems instead." #-}
--- | Obsolete equivalent of 'elems'.
-setToList :: Set a -> [a] 
-setToList = elems
-
-{-# DEPRECATED unitSet "Use singleton instead." #-}
--- | Obsolete equivalent of 'singleton'.
-unitSet :: a -> Set a
-unitSet = singleton
-
-{-# DEPRECATED elementOf "Use member instead." #-}
--- | Obsolete equivalent of 'member'.
-elementOf :: Ord a => a -> Set a -> Bool
-elementOf = member
-
-{-# DEPRECATED isEmptySet "Use null instead." #-}
--- | Obsolete equivalent of 'null'.
-isEmptySet :: Set a -> Bool
-isEmptySet = null
-
-{-# DEPRECATED cardinality "Use size instead." #-}
--- | Obsolete equivalent of 'size'.
-cardinality :: Set a -> Int
-cardinality = size
-
-{-# DEPRECATED unionManySets "Use unions instead." #-}
--- | Obsolete equivalent of 'unions'.
-unionManySets :: Ord a => [Set a] -> Set a
-unionManySets = unions
-
-{-# DEPRECATED minusSet "Use difference instead." #-}
--- | Obsolete equivalent of 'difference'.
-minusSet :: Ord a => Set a -> Set a -> Set a
-minusSet = difference
-
-{-# DEPRECATED mapSet "Use map instead." #-}
--- | Obsolete equivalent of 'map'.
-mapSet :: (Ord a, Ord b) => (b -> a) -> Set b -> Set a
-mapSet = map
-
-{-# DEPRECATED intersect "Use intersection instead." #-}
--- | Obsolete equivalent of 'intersection'.
-intersect :: Ord a => Set a -> Set a -> Set a
-intersect = intersection
-
-{-# DEPRECATED addToSet "Use 'flip insert' instead." #-}
--- | Obsolete equivalent of @'flip' 'insert'@.
-addToSet :: Ord a => Set a -> a -> Set a
-addToSet = flip insert
-
-{-# DEPRECATED delFromSet "Use `flip delete' instead." #-}
--- | Obsolete equivalent of @'flip' 'delete'@.
-delFromSet :: Ord a => Set a -> a -> Set a
-delFromSet = flip delete