{-# 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