module Bitwise exposing
  ( and, or, xor, complement
  , shiftLeftBy, shiftRightBy, shiftRightZfBy
  )

{-| Library for [bitwise operations](http://en.wikipedia.org/wiki/Bitwise_operation).

# Basic Operations
@docs and, or, xor, complement

# Bit Shifts
@docs shiftLeftBy, shiftRightBy, shiftRightZfBy
-}

import Native.Bitwise


{-| Bitwise AND
-}
and : Int -> Int -> Int
and =
  Native.Bitwise.and


{-| Bitwise OR
-}
or : Int -> Int -> Int
or =
  Native.Bitwise.or


{-| Bitwise XOR
-}
xor : Int -> Int -> Int
xor =
  Native.Bitwise.xor


{-| Flip each bit individually, often called bitwise NOT
-}
complement : Int -> Int
complement =
  Native.Bitwise.complement


{-| Shift bits to the left by a given offset, filling new bits with zeros.
This can be used to multiply numbers by powers of two.

    shiftLeftBy 1 5 == 10
    shiftLeftBy 5 1 == 32
-}
shiftLeftBy : Int -> Int -> Int
shiftLeftBy =
  Native.Bitwise.shiftLeftBy


{-| Shift bits to the right by a given offset, filling new bits with
whatever is the topmost bit. This can be used to divide numbers by powers of two.

    shiftRightBy 1  32 == 16
    shiftRightBy 2  32 == 8
    shiftRightBy 1 -32 == -16

This is called an [arithmetic right shift][ars], often written (>>), and
sometimes called a sign-propagating right shift because it fills empty spots
with copies of the highest bit.

[ars]: http://en.wikipedia.org/wiki/Bitwise_operation#Arithmetic_shift
-}
shiftRightBy : Int -> Int -> Int
shiftRightBy =
  Native.Bitwise.shiftRightBy


{-| Shift bits to the right by a given offset, filling new bits with zeros.

    shiftRightZfBy 1  32 == 16
    shiftRightZfBy 2  32 == 8
    shiftRightZfBy 1 -32 == 2147483632

This is called an [logical right shift][lrs], often written (>>>), and
sometimes called a zero-fill right shift because it fills empty spots with
zeros.

[lrs]: http://en.wikipedia.org/wiki/Bitwise_operation#Logical_shift
-}
shiftRightZfBy : Int -> Int -> Int
shiftRightZfBy =
  Native.Bitwise.shiftRightZfBy