
  $ cat > nested_variants.ml << "EOF"
  > type tt =
  >   | A of
  >       int
  >   | B of
  >       string
  >   | C of
  >       float
  >   | D of
  >       char
  > 
  > type tt = [
  >   | `a of int
  >   | `blskdjf of
  >       float
  >   | `problem_cause of [ `more_brackets ]
  >   | `problematic_case of
  >       string
  > ]
  > EOF

  $ ocp-indent nested_variants.ml
  type tt =
    | A of
        int
    | B of
        string
    | C of
        float
    | D of
        char
  
  type tt = [
    | `a of int
    | `blskdjf of
        float
    | `problem_cause of [ `more_brackets ]
    | `problematic_case of
        string
  ]
