class Parser::Lexer

def source_buffer=(source_buffer)
  @source_buffer = source_buffer
  if @source_buffer
    source = @source_buffer.source
    # Force UTF8 unpacking even if JS works with UTF-16/UCS-2
    # See: https://mathiasbynens.be/notes/javascript-encoding
    @source_pts = source.unpack('U*')
  else
    @source_pts = nil
  end
  # Since parser v3.2.1 Parser::Lexer has @strings
  if @strings
    @strings.source_buffer = @source_buffer
    @strings.source_pts = @source_pts
  end
end