class Crass::Scanner

def peek(length = 1)

_length_ if the end of the string is reached.
doesn't consume them. The number of characters returned may be less than
Returns up to _length_ characters starting at the current position, but 
def peek(length = 1)
  # Grab the bytes for up to _length_ characters and then take the first
  # _length_ characters. A UTF-8 character is at most four bytes, so `length
  # * 4` bytes always contains at least _length_ whole characters when that
  # many remain. This avoids the O(n) character-offset slice that
  # `@string[pos, length]` would otherwise perform on multi-byte input.
  @string.byteslice(@scanner.pos, length * 4).slice(0, length) || ''
end