Re: [Haskell-cafe] Re: Array copying

[Andrew Coppin]

ChrisK wrote:
For GHC 6.6 I created
  
foreign import ccall unsafe "memcpy"
    memcpy :: MutableByteArray# RealWorld -> MutableByteArray# RealWorld -> Int# 
-> IO ()
    

  
{-# INLINE copySTU #-}
copySTU :: (Show i,Ix i,MArray (STUArray s) e (ST s)) => STUArray s i e -> 
STUArray s i e -> ST s ()
copySTU (STUArray _ _ msource) (STUArray _ _ mdest) =
-- do b1 <- getBounds s1
--  b2 <- getBounds s2
--  when (b1/=b2) (error ("\n\nWTF copySTU: "++show (b1,b2)))
  ST $ \s1# ->
    case sizeofMutableByteArray# msource        of { n# ->
    case unsafeCoerce# memcpy mdest msource n# s1# of { (# s2#, () #) ->
    (# s2#, () #) }}
    

To allow efficient copying of STUArrays.
  

So... that copies the entire array into another array of the same size? 
(I'm having a lot of trouble understanding the code...)
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