# Returns self as a stream of bits (0 and 1)
	#
	# ~~~
	# var b = "abcd".to_bytes
	# assert b.binarydigest == "01100001011000100110001101100100"
	# assert b.binarydigest.binarydigest_to_bytes == b
	# ~~~
	fun binarydigest: String do
		var elen = length * 8
		var ns = new CString(elen)
		var i = 0
		var oi = 0
		while i < length do
			var c = self[i]
			var b = 128
			while b > 0 do
				if c & b == 0 then
					ns[oi] = u'0'
				else
					ns[oi] = u'1'
				end
				oi += 1
				b = b >> 1
			end
			i += 1
		end
		return new FlatString.full(ns, elen, 0, elen)
	end