{--
JVM-Bridge -- bridge from FP languages and others to the Java VM
Copyright (C) 2001 Ashley Yakeley <ashley@semantic.org>

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
--}

module Data.Bytes where
	{
	import Data.Word;
	import Data.Int;
	import Data.Bits;
	
	lo8 :: Word16 -> Word8;
	lo8 = fromIntegral;
	
	hi8 :: Word16 -> Word8;
	hi8 x = fromIntegral (shiftR x 8);
	
	lo16 :: Word32 -> Word16;
	lo16 = fromIntegral;
	
	hi16 :: Word32 -> Word16;
	hi16 x = fromIntegral (shiftR x 16);
	
	lo32 :: Word64 -> Word32;
	lo32 = fromIntegral;
	
	hi32 :: Word64 -> Word32;
	hi32 x = fromIntegral (shiftR x 32);
	
	toWord8 :: Int8 -> Word8;
	toWord8 = fromIntegral;
	
	toWord16 :: Int16 -> Word16;
	toWord16 = fromIntegral;
	
	toInt16 :: Word16 -> Int16;
	toInt16 = fromIntegral;
	
	toWord32 :: Int32 -> Word32;
	toWord32 = fromIntegral;
	
	toWord64 :: Int64 -> Word64;
	toWord64 = fromIntegral;
	
	downInt8 :: Int16 -> Maybe Int8;
	downInt8 n = if ((hib == 0) || (hib == 0xFF80)) then (Just (fromIntegral n)) else Nothing where
		{
		hib = n .&. 0xFF80;
		};
	
	upInt16 :: Int8 -> Int16;
	upInt16 = fromIntegral;
	
	upWord16 :: Word8 -> Word16;
	upWord16 = fromIntegral;
	
	downInt16 :: Int32 -> Maybe Int16;
	downInt16 n = if ((hib == 0) || (hib == 0xFFFF8000)) then (Just (fromIntegral n)) else Nothing where
		{
		hib = n .&. 0xFFFF8000;
		};
	}