Unsigned integral types

This module provides unsigned integer types of unspecified width (Word) and fixed widths (Word8, Word16, Word32 and Word64). All arithmetic is performed modulo 2^n, where n is the number of bits in the type.

For coercing between any two integer types, use fromIntegral. Coercing word types to and from integer types preserves representation, not sign.

The rules that hold for Enum instances over a bounded type such as Int (see the section of the Haskell language report dealing with arithmetic sequences) also hold for the Enum instances over the various Word types defined here.

Right and left shifts by amounts greater than or equal to the width of the type result in a zero result. This is contrary to the behaviour in C, which is undefined; a common interpretation is to truncate the shift count to the width of the type, for example 1 << 32 == 1 in some C implementations.