Is the last read byte matches the S production?

Property definitions

saxophonit $ XophonLexer :: is_s
	# Is the last read byte matches the `S` production?
	fun is_s:Bool do
		return last_char == 32 or last_char == 9 or last_char == 10
	end
lib/saxophonit/lexer.nit:101,2--104,4