combobulate.lisp

(defun f. (&rest r)
  (if (cdr r)
      (progn (apply 'format t      r) (terpri) (cadr r))
      (progn (apply 'format t "~s" r) (terpri) (car  r))))
(defvar x0 '((0 (format t "[~s]~%" 101))))
(defvar x1 '((0 (if t \:))
	     (1 (format t "[~s]~%" 102))
	     (1 (format t "[~s]~%" 103))
	     ))
(defvar xx '((0 nil)))
(defvar x2 '((0 (if t \:))
	     (1     (format t "[~s]~%" 104))
	     (1     (format t "[~s]~%" 105))
	     (1     (if t \:))
	     (2         (format t "[~s]~%" 106))
	     (2         (format t "[~s]~%" 107))
	     (1     (format t "[~s]~%" 108))
	     (0 (format t "[~s]~%" 109))
	     ))
(defun next-stmt (x)
  (labels ((ewc  (x) (eq '\: (car (last x))))
	   (blk  (n) (if (eq (caar x) n) (append (stmt) (blk n))))
	   (stmt ()  (if x (let* ((y (pop x))
				  (z (pop y))
				  (w (pop y)))
			     (if (null (ewc w)) (list w)
				 (list (append
					(butlast w)
					(list (cons 'progn (blk (caar x)))))))))))
    (let* ((a (stmt)))
      (if (member (caar x) (list nil 0)) (values a x)
	  (error "indent error")))))
(f. "------------------------------1")
(f. (next-stmt x0))
(f. "------------------------------2")
(f. (next-stmt x1))
(f. "------------------------------3")
(f. (next-stmt x2))
(f. "------------------------------4")
(f. (next-stmt xx))
(f. "------------------------------5")
(f. (next-stmt nil))
(f. "------------------------------6")

Makefile

combobulate:
  sbcl --script $*.lisp
  ecl -load $*.lisp -eval '(quit)'
  ccl64 --load $*.lisp --eval '(quit)'