offset_source_tokens

# File actionview/lib/action_view/template/handlers/erb.rb, line 177
        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