(define-module (language python class)
  #:export (class_+ class_- class_* class_// class_%
		    class_power class_<< class_>> class_ior
		    class_xor class_band))

(define-syntax-rule (class-ref x) (struct-ref x 0))
(define-syntax-rule (class-num x) (struct-ref x 1))
(define-syntax-rule (class-log x) (struct-ref x 2))
(define-syntax-rule (class-map x) (struct-ref x 3))

(define-syntax-rule (mkref +-ref n)
  (define-syntax-rule (+-ref x)     (vector-ref x n)))

(mkref +-ref     0)
(mkref --ref     1)
(mkref *-ref     2)
(mkref /-ref     3)
(mkref //-ref    4)
(mkref %-ref     5)
(mkref **-ref    6)
(mkref <<-ref    7)
(mkref >>-ref    8)

(mkref ior-ref   0)
(mkref xor-ref   1)
(mkref and-ref   2)

(define-syntax-rule (class-lookup class key )
  (hashq-ref (class-map class) key #f))

(define-syntax-rule (meta-mk mk-num class-num)
(define-syntax-rule (mk-num class_+ __add__ __radd__ +-ref  err)
  (define (class_+ x y)
    (let* ((cl (class-ref  x))
	   (r  (class-num cl)))
      (define (f)
	(let ((rrr (class-lookup cl '__add__)))
	  (if rrr
	      (rrr x y)
	      (if (class? y)
		  (let* ((cl   (class-ref y))
			 (rrrr (class-lookup cl '__radd__)))
		    (if rrrr
			(rrrr y x)
			(err)))
		  (err)))))
	 
      (if r
          (let ((rr (+-ref r)))
            (if rr
                (rr x y)
                (f)))
	  (f))))))
			    
(meta-mk mk-num class-num)
(meta-mk mk-log class-log)

(define (err) (error "could not do artithmetic ops"))

(mk-num class_+      __add__      __radd__         +-ref  err)
(mk-num class_-      __sub__      __rsub__         --ref  err)
(mk-num class_*      __mul__      __rmul__         *-ref  err)
(mk-num class_/      __div__      __rdiv__         /-ref  err)
(mk-num class_//     __floordiv__ __rfloordiv__    //-ref err)
(mk-num class_%      __divmod__   __rdivmod__      %-ref  err)
(mk-num class_power  __pow__      __rpow__         **-ref err)
(mk-num class_<<     __lshift__   __rlshift__      <<-ref err)
(mk-num class_>>     __rshift__   __rrshift__      >>-ref err)
(mk-log class_ior    __or__       __ror__         ior-ref err)
(mk-log class_xor    __xor__      __rxor__        xor-ref err)
(mk-log class_band   __and__      __rand__        and-ref err)