module Mail::ContentDisposition

def _nt_value
  start_index = index
  if node_cache[:value].has_key?(index)
    cached = node_cache[:value][index]
    @index = cached.interval.end if cached
    return cached
  end
  i0 = index
  r1 = _nt_quoted_string
  r1.extend(Value0)
  if r1
    r0 = r1
  else
    s2, i2 = [], index
    loop do
      i3 = index
      r4 = _nt_token
      if r4
        r3 = r4
      else
        if has_terminal?('\G[\\x3d]', true, index)
          r5 = true
          @index += 1
        else
          r5 = nil
        end
        if r5
          r3 = r5
        else
          @index = i3
          r3 = nil
        end
      end
      if r3
        s2 << r3
      else
        break
      end
    end
    if s2.empty?
      @index = i2
      r2 = nil
    else
      r2 = instantiate_node(SyntaxNode,input, i2...index, s2)
    end
    if r2
      r0 = r2
    else
      @index = i0
      r0 = nil
    end
  end
  node_cache[:value][start_index] = r0
  r0
end