(define-module (language python module bisect)
  #:use-module (oop pf-objects)
  #:use-module (language python list)
  #:use-module (language python def)
  #:use-module (language python try)
  #:use-module (language python exceptions)
  #:export (insort_right insort bisect bisect_right
			 bisect_left insort_left))

(def (insort_right a x (= lo 0) (= hi None))
    "Insert item x in list a, and keep it sorted assuming a is sorted.

    If x is already in a, insert it to the right of the rightmost x.

    Optional args lo (default 0) and hi (default len(a)) bound the
    slice of a to be searched.
    "

    (if (< lo 0)
        (raise ValueError "lo must be non-negative"))
    (if (eq? hi None)
        (set! hi (len a)))

    (call-with-values
	(lambda ()
	  (let lp ((lo lo) (hi hi))
	    (if (< lo hi)
		(let ((mid (quotient (+ lo hi) 2)))
		  (if (< x (pylist-ref a mid))
		      (lp lo        mid)
		      (lp (+ mid 1) hi )))
		(values lo hi))))
      (lambda (lo hi)
	(pylist-insert! a lo x))))

(define insort insort_right)

(def (bisect_right a x (= lo 0) (= hi None))
    "Return the index where to insert item x in list a, assuming a is sorted.

    The return value i is such that all e in a[:i] have e <= x, and all e in
    a[i:] have e > x.  So if x already appears in the list, a.insert(x) will
    insert just after the rightmost x already there.

    Optional args lo (default 0) and hi (default len(a)) bound the
    slice of a to be searched.
    "

    (if (< lo 0)
        (raise ValueError "lo must be non-negative"))
    (if (eq? hi None)
        (set! hi (len a)))

    (call-with-values
	(lambda ()
	  (let lp ((lo lo) (hi hi))
	    (if (< lo hi)
		(let ((mid (quotient (+ lo hi) 2)))
		  (if (< x (pylist-ref a mid))
		      (lp lo        mid)
		      (lp (+ mid 1) hi )))
		(values lo hi))))
      (lambda (lo hi)
	lo)))

(define bisect bisect_right)

(def (insort_left a x (= lo 0) (= hi None))
    "Insert item x in list a, and keep it sorted assuming a is sorted.

    If x is already in a, insert it to the left of the leftmost x.

    Optional args lo (default 0) and hi (default len(a)) bound the
    slice of a to be searched.
    "
     
    (if (< lo 0)
        (raise ValueError "lo must be non-negative"))
    (if (eq? hi None)
        (set! hi (len a)))

    (call-with-values
	(lambda ()
	  (let lp ((lo lo) (hi hi))
	    (if (< lo hi)
		(let ((mid (quotient (+ lo hi) 2)))
		  (if (< (pylist-ref a mid) x)
		      (lp (+ mid 1) hi )
		      (lp lo        mid)))
		      
		(values lo hi))))
      (lambda (lo hi)
	(pylist-insert! a lo x))))


(def (bisect_left a x (= lo 0) (= hi None))
    "Return the index where to insert item x in list a, assuming a is sorted.

    The return value i is such that all e in a[:i] have e < x, and all e in
    a[i:] have e >= x.  So if x already appears in the list, a.insert(x) will
    insert just before the leftmost x already there.

    Optional args lo (default 0) and hi (default len(a)) bound the
    slice of a to be searched.
    "

    (if (< lo 0)
        (raise ValueError "lo must be non-negative"))
    (if (eq? hi None)
        (set! hi (len a)))

    (call-with-values
	(lambda ()
	  (let lp ((lo lo) (hi hi))
	    (if (< lo hi)
		(let ((mid (quotient (+ lo hi) 2)))
		  (if (< (pylist-ref a mid) x)
		      (lp (+ mid 1) hi )
		      (lp lo        mid)))
		      
		(values lo hi))))
      (lambda (lo hi)
	lo)))