;;; -*-scheme-*-

;;; Mes --- Maxwell Equations of Software
;;; Copyright © 2016 Jan Nieuwenhuizen <janneke@gnu.org>
;;;
;;; quasiquote.mes: This file is part of Mes.
;;;
;;; Mes is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; Mes is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with Mes.  If not, see <http://www.gnu.org/licenses/>.

(define-macro (works-but-sloooooow-quasiquote x)
  (define (check x)
    (cond ((pair? (cdr x)) (cond ((null? (cddr x)))
                                 (#t (error (car x) "invalid form ~s" x))))))
  (define (loop x)
    ;;(display "LOOP") (newline)
    (cond
     ((not (pair? x)) (cons 'quote (cons x '())))
     ((eq? (car x) 'quasiquote) (check x) (loop (loop (cadr x))))
     ((eq? (car x) 'unquote) (check x) (cadr x))
     ((eq? (car x) 'unquote-splicing)
      (error 'unquote-splicing "invalid context for ~s" x))
     (;;(and (pair? (car x)) (eq? (caar x) 'unquote-splicing))
      (cond ((pair? (car x)) (eq? (caar x) 'unquote-splicing))
            (#t #f))
      (check (car x))
      ;; (let ((d (loop (cdr x))))
      ;;   (cond ((equal? d '(quote ())) (cadar x))
      ;;         ;;(#t `(append ,(cadar x) ,d))
      ;;         (#t (list 'append (cadar x) d))
      ;;         ))
      ((lambda (d)
         (list 'append (cadar x) d))
       (loop (cdr x))))
     (#t
      ;; (let ((a (loop (car x)))
      ;;       (d (loop (cdr x))))
      ;;   (cond ((pair? d)
      ;;          (cond ((eq? (car d) 'quote)
      ;;                 (cond ((and (pair? a) (eq? (car a) 'quote))
      ;;                        `'(,(cadr a) . ,(cadr d)))
      ;;                       (#t (cond ((null? (cadr d))
      ;;                                  `(list ,a))
      ;;                                 (#t `(cons* ,a ,d))))))
      ;;                (#t (cond ((memq (car d) '(list cons*))
      ;;                           `(,(car d) ,a ,@(cdr d)))
      ;;                          (#t `(cons* ,a ,d))))))
      ;;         (#t `(cons* ,a ,d))))

      ((lambda (a d)
         ;;(display "LAMBDA AD") (newline)
         (cond ((pair? d)
                (cond ((eq? (car d) 'quote)
                       (cond (;;(and (pair? a) (eq? (car a) 'quote))
                              (cond ((pair? a) (eq? (car a) 'quote))
                                    (#t #f))
                              (list 'quote (cons (cadr a) (cadr d))))
                             (#t (cond ((null? (cadr d))
                                        (list 'list a))
                                       (#t (list 'cons* a d))))))
                      (#t (cond ((memq (car d) '(list cons*))
                                 ;;`(,(car d) ,a ,@(cdr d))
                                 (cons (car d) (cons a (cdr d)))
                                 )
                                ;;(#t `(cons* ,a ,d))
                                (#t (list 'cons* a d))
                                ))))
               ;;(#t `(cons* ,a ,d))
               (#t (list 'cons* a d))
               ))
       (loop (car x))
       (loop (cdr x)))

      )))
  (loop x))