{-# OPTIONS_LHC -N -funboxed-tuples -fffi #-}
module Lhc.Array where

import Lhc.Basics
import Lhc.IO
import Lhc.Int



data MutArray__ :: * -> #
data Array__ :: * -> #

foreign import primitive newMutArray__      :: Int__ -> a -> UIO (MutArray__ a)
foreign import primitive newBlankMutArray__ :: Int__ -> UIO (MutArray__ a)
foreign import primitive copyArray__        :: Int__ -> Int__ -> Int__ -> Array__ a -> MutArray__ a -> UIO_
foreign import primitive copyMutArray__     :: Int__ -> Int__ -> Int__ -> MutArray__ a -> MutArray__ a -> UIO_
foreign import primitive readArray__        :: MutArray__ a -> Int__ -> UIO a
foreign import primitive writeArray__       :: MutArray__ a -> Int__ -> a -> UIO_
foreign import primitive indexArray__       :: Array__ a -> Int__ -> (# a #)

-- these basically cast from a mutable to an immutable array and back again
foreign import primitive unsafeFreezeArray__ :: MutArray__ a -> UIO (Array__ a)
foreign import primitive unsafeThawArray__ :: Array__ a -> UIO (MutArray__ a)

foreign import primitive newWorld__ :: a -> World__

newArray :: a -> Int -> [(Int,a)] -> Array__ a
newArray init n xs = case unboxInt n of
    n' -> case newWorld__ (init,n,xs) of
     w -> case newMutArray__ n' init w of
      (# w, arr #) -> let
        f :: MutArray__ a -> World__ -> [(Int,a)] -> World__
        f arr w [] = w
        f arr w ((i,v):xs) = case unboxInt i of i' -> case writeArray__ arr i' v w of w -> f arr w xs
            in case f arr w xs of w -> case unsafeFreezeArray__ arr w  of (# _, r #) -> r