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|
{-# LANGUAGE Unsafe #-}
{-# LANGUAGE NoImplicitPrelude, RoleAnnotations #-}
{-# OPTIONS_GHC -funbox-strict-fields #-}
{-# OPTIONS_HADDOCK not-home #-}
-----------------------------------------------------------------------------
-- |
-- Module : GHC.IOArray
-- Copyright : (c) The University of Glasgow 2008
-- License : see libraries/base/LICENSE
--
-- Maintainer : cvs-ghc@haskell.org
-- Stability : internal
-- Portability : non-portable (GHC Extensions)
--
-- The IOArray type
--
-----------------------------------------------------------------------------
module GHC.IOArray (
IOArray(..),
newIOArray, unsafeReadIOArray, unsafeWriteIOArray,
readIOArray, writeIOArray,
boundsIOArray
) where
import GHC.Base
import GHC.IO
import GHC.Arr
-- ---------------------------------------------------------------------------
-- | An 'IOArray' is a mutable, boxed, non-strict array in the 'IO' monad.
-- The type arguments are as follows:
--
-- * @i@: the index type of the array (should be an instance of 'Ix')
--
-- * @e@: the element type of the array.
--
--
newtype IOArray i e = IOArray (STArray RealWorld i e)
-- index type should have a nominal role due to Ix class. See also #9220.
type role IOArray nominal representational
-- explicit instance because Haddock can't figure out a derived one
-- | @since 4.1.0.0
instance Eq (IOArray i e) where
IOArray x == IOArray y = x == y
-- |Build a new 'IOArray'
newIOArray :: Ix i => (i,i) -> e -> IO (IOArray i e)
{-# INLINE newIOArray #-}
newIOArray lu initial = stToIO $ do {marr <- newSTArray lu initial; return (IOArray marr)}
-- | Read a value from an 'IOArray'
unsafeReadIOArray :: IOArray i e -> Int -> IO e
{-# INLINE unsafeReadIOArray #-}
unsafeReadIOArray (IOArray marr) i = stToIO (unsafeReadSTArray marr i)
-- | Write a new value into an 'IOArray'
unsafeWriteIOArray :: IOArray i e -> Int -> e -> IO ()
{-# INLINE unsafeWriteIOArray #-}
unsafeWriteIOArray (IOArray marr) i e = stToIO (unsafeWriteSTArray marr i e)
-- | Read a value from an 'IOArray'
readIOArray :: Ix i => IOArray i e -> i -> IO e
readIOArray (IOArray marr) i = stToIO (readSTArray marr i)
-- | Write a new value into an 'IOArray'
writeIOArray :: Ix i => IOArray i e -> i -> e -> IO ()
writeIOArray (IOArray marr) i e = stToIO (writeSTArray marr i e)
{-# INLINE boundsIOArray #-}
boundsIOArray :: IOArray i e -> (i,i)
boundsIOArray (IOArray marr) = boundsSTArray marr
|
