remove Data.FunctorM and Data.Queue

[ghc-base.git] / Data / Queue.hs

diff --git a/Data/Queue.hs b/Data/Queue.hs
deleted file mode 100644 (file)
index 55abe39..0000000
--- a/Data/Queue.hs
+++ /dev/null
@@ -1,86 +0,0 @@
------------------------------------------------------------------------------
--- |
--- Module      :  Data.Queue
--- Copyright   :  (c) The University of Glasgow 2002
--- License     :  BSD-style (see the file libraries/base/LICENSE)
--- 
--- Maintainer  :  libraries@haskell.org
--- Stability   :  experimental
--- Portability :  portable
---
--- NOTE: This module is DEPRECATED.
--- The data structure in "Data.Sequence" is a faster queue and also
--- supports a wider variety of operations.
---
--- Queues with constant time operations, from
--- /Simple and efficient purely functional queues and deques/,
--- by Chris Okasaki, /JFP/ 5(4):583-592, October 1995.
---
------------------------------------------------------------------------------
-
-module Data.Queue
-{-# DEPRECATED "Use Data.Sequence instead: it's faster and has more operations" #-}
-       (Queue,
-       -- * Primitive operations
-       -- | Each of these requires /O(1)/ time in the worst case.
-       emptyQueue, addToQueue, deQueue,
-       -- * Queues and lists
-       listToQueue, queueToList
-    ) where
-
-import Prelude -- necessary to get dependencies right
-import Data.Typeable
-
--- | The type of FIFO queues.
-data Queue a = Q [a] [a] [a]
-
-#include "Typeable.h"
-INSTANCE_TYPEABLE1(Queue,queueTc,"Queue")
-
--- Invariants for Q xs ys xs':
---     length xs = length ys + length xs'
---     xs' = drop (length ys) xs       -- in fact, shared (except after fmap)
--- The queue then represents the list xs ++ reverse ys
-
-instance Functor Queue where
-       fmap f (Q xs ys xs') = Q (map f xs) (map f ys) (map f xs')
-       -- The new xs' does not share the tail of the new xs, but it does
-       -- share the tail of the old xs, so it still forces the rotations.
-       -- Note that elements of xs' are ignored.
-
--- | The empty queue.
-emptyQueue :: Queue a
-emptyQueue = Q [] [] []
-
--- | Add an element to the back of a queue.
-addToQueue :: Queue a -> a -> Queue a
-addToQueue (Q xs ys xs') y = makeQ xs (y:ys) xs'
-
--- | Attempt to extract the front element from a queue.
--- If the queue is empty, 'Nothing',
--- otherwise the first element paired with the remainder of the queue.
-deQueue :: Queue a -> Maybe (a, Queue a)
-deQueue (Q [] _ _) = Nothing
-deQueue (Q (x:xs) ys xs') = Just (x, makeQ xs ys xs')
-
--- Assuming
---     length ys <= length xs + 1
---     xs' = drop (length ys - 1) xs
--- construct a queue respecting the invariant.
-makeQ :: [a] -> [a] -> [a] -> Queue a
-makeQ xs ys [] = listToQueue (rotate xs ys [])
-makeQ xs ys (_:xs') = Q xs ys xs'
-
--- Assuming length ys = length xs + 1,
---     rotate xs ys zs = xs ++ reverse ys ++ zs
-rotate :: [a] -> [a] -> [a] -> [a]
-rotate [] (y:_) zs = y : zs            -- the _ here must be []
-rotate (x:xs) (y:ys) zs = x : rotate xs ys (y:zs)
-
--- | A queue with the same elements as the list.
-listToQueue :: [a] -> Queue a
-listToQueue xs = Q xs [] xs
-
--- | The elements of a queue, front first.
-queueToList :: Queue a -> [a]
-queueToList (Q xs ys _) = xs ++ reverse ys