func doLength
  fvar(s)
  s = 'len(' && Text && ')'
  if(linked(Result))
    println(len, ' = ', s)
    event(onLength, len)
  else  
    event(onLength, s)
  end
end

func Result
  if(linked(doLength))
    return(len)
  else
    return('len(' && Text && ')')  
  end
end