Bitwise operators in GLua

README.md

Implementation of bitwise operators in GLua

Just for variety.

As for performance, it's obviously slower, but not that much.

With JIT it's somehow faster sometimes.

Demo

print( (1) '<<' (0) ) -- 1
print( (1) '<<' (1) ) -- 2
print( (1) '<<' (2) ) -- 4

local flags = (2) '|' (4, 8, 256, 512)

if ( flags '&' (512) ~= 0 ) then
	print( 'flag 512 is set' )
end

implement_bitwise_operators.lua

local lshift = bit.lshift
local rshift = bit.rshift
local bor = bit.bor
local band = bit.band


local numberToManipulate


local function operator_lshift( shiftCount )

	return lshift( numberToManipulate, shiftCount )

end

local function operator_rshift( shiftCount )

	return rshift( numberToManipulate, shiftCount )

end

local function operator_bor( ... )

	return bor( numberToManipulate, ... )

end

local function operator_band( ... )

	return band( numberToManipulate, ... )

end


debug.setmetatable( 0, {

	__call = function( thisNumber, operator )

		numberToManipulate = thisNumber

		if ( operator == '<<' ) then
			return operator_lshift
		elseif ( operator == '>>' ) then
			return operator_rshift
		elseif ( operator == '|' ) then
			return operator_bor
		elseif ( operator == '&' ) then
			return operator_band
		end

	end;

} )