[PATCH] Add new lisp function length= with bytecode support

[Constantin Kulikov]

Why not `length-cmp' which will -1 if less, 0 if equal, 1 if greater?

(defun length-cmp (seq n)

  (let* ((len (if seq (if (consp seq)

                          (let ((tlen 0))

                            (while (and seq (< tlen (1+ n)))

                              (incf tlen) (setq seq (cdr seq)))

                            tlen)

                        (length seq))

                0)))

    (if (< len n) -1 (if (> len n) 1 0))))

All other functions can be build on top of it.