class Crass::Scanner

def marked
  # Extract the marked text using byte offsets rather than character
  # offsets. Slicing the original string by character offset is O(n) on
  # multi-byte input (Ruby must translate the character index into a byte
  # index), which makes tokenizing non-ASCII input superlinear. Byte slicing
  # is O(length) regardless of how far into the string we are.
  @string.byteslice(@byte_marker, @scanner.pos - @byte_marker) || ''
end