length

  the length of a piece of text in unicode code points.  This is usually, but not
  always, the same as the length of the text in user-perceived characters.

Examples:

  length('hello')
  -- Result: "5"

  length("\u00e1") -- composed 'á'
  -- Result: "1"

  length("a\u0301") -- decomposed 'á'
  -- Result: "2"

text -> number