on int_2_string_twos_complement(i, base, bit_length)
	-- check for range
	set i to i as integer
	if i >= 2 ^ (bit_length - 1) then
		error "Can not convert integer to string integer too high for given bit length" number 1700
	end if
	if i < -(2 ^ (bit_length - 1)) then
		error "Can not convert integer to string integer too low for given bit length" number 1700
	end if
	if i < 0 then
		set i to i + 2 ^ bit_length
	end if
	set res to int_2_string(i, base)
	-- filling with zeroes
	-- calculate number of digitsset 
	set dc to (length of int_2_string(2 ^ bit_length - 1, base))
	repeat while length of res < dc
		set res to "0" & res
	end repeat
	return res
end int_2_string_twos_complement