# Read `self` as raw text until `nend` and append it to the `out` buffer.
	# No escape is made.
	private fun read_raw_until(out: FlatBuffer, start: Int, nend: Char...): Int do
		var pos = start
		while pos < length do
			var c = self[pos]
			var end_reached = false
			for n in nend do
				if c == n then
					end_reached = true
					break
				end
			end
			if end_reached then break
			out.add c
			pos += 1
		end
		if pos == length then return -1
		return pos
	end