class ActionView::Template::Handlers::ERB

def offset_source_tokens(source_tokens)
  source_offset = 0
  with_offset = source_tokens.filter_map do |name, str|
    result = [:CODE, str, source_offset] if name == :CODE || name == :PLAIN
    result = [:TEXT, str, source_offset] if name == :TEXT
    source_offset += str.bytesize
    result
  end
  with_offset << [:EOS, nil, source_offset]
end