# Read a string until the end of the line.
	#
	# The line terminator '\n' and '\r\n', if any, is removed in each line.
	#
	# ~~~
	# var txt = "Hello\n\nWorld\n"
	# var i = new StringReader(txt)
	# assert i.read_line == "Hello"
	# assert i.read_line == ""
	# assert i.read_line == "World"
	# assert i.eof
	# ~~~
	#
	# Only LINE FEED (`\n`), CARRIAGE RETURN & LINE FEED (`\r\n`), and
	# the end or file (EOF) is considered to delimit the end of lines.
	# CARRIAGE RETURN (`\r`) alone is not used for the end of line.
	#
	# ~~~
	# var txt2 = "Hello\r\n\n\rWorld"
	# var i2 = new StringReader(txt2)
	# assert i2.read_line == "Hello"
	# assert i2.read_line == ""
	# assert i2.read_line == "\rWorld"
	# assert i2.eof
	# ~~~
	#
	# NOTE: Use `append_line_to` if the line terminator needs to be preserved.
	fun read_line: String
	do
		if last_error != null then return ""
		if eof then return ""
		var s = new FlatBuffer
		append_line_to(s)
		return s.to_s.chomp
	end