Conversion: Algebraic - Polish - Reverse Polish - LISP ?

[John Keith]

(11-01-2024 07:08 PM)Thomas Klemm Wrote:  It turned out to be easier than I expected.
Save the following program in →PN:

Code:

« OBJ→
  IF OVER
  THEN → n f
    « 1 n
      FOR i
        IF DUP TYPE 9 SAME
        THEN →PN
        END 1 →LIST n ROLLD
      NEXT
      IF n 1 >
      THEN 2 n
        START +
        NEXT
      END f SWAP +
    »
  ELSE 1 →LIST SWAP DROP
  END
»

Very neat program! One question: Is there a reason that the first loop is a FOR loop rather than a START loop? I don't see a reference to i anywhere in the program.