Break up a list of numbers into groups of 2

[lfe011969]

My job took me away from AutoCAD for a good while but I'm back behind a desk and I'm really rusty with my AutoLISP.

How can I take a list of numbers and put them of groups of two? For example, if my list is this:

(1 2 3 4 5 6 7 8)

How can I get it to look like this:

(1 2)(3 4)(5 6)(7 8)

or even this:

(1 . 2)(3 . 4)(5 . 6)(7 . 8)

As always, any help would be appreciated.

[Lee Mac]

(defun f ( l ) (if l (cons (list (car l) (cadr l)) (f (cddr l)))))

(defun g ( l ) (if l (cons (cons (car l) (cadr l)) (g (cddr l)))))

Generic function.

[lfe011969]

I guess I should've known you would already have a solution. Thanks!

[David Bethel]

Or maybe:

(defun test (l / tmp)
  (and (zerop (rem (length l) 2)
       (while (< (length l) 1)
              (setq tmp (cons (list (car l) (cadr l)) tmp)
              (setq l (cddr l)) 
     tmp))

-David

[pBe]

Or maybe:

(defun test (l / tmp)....

-David

something missing David? .. perhaps

(defun test (l / tmp)
  (and (zerop (rem (length l) 2))
       (while (> (length l) 1)
              (setq tmp (cons (list (car l) (cadr l)) tmp)
                l (cddr l))
             ))
     (reverse tmp)
      )

(defun _relist  (l n / x ln ls)
      (if (zerop (rem (length l) n))
            (repeat (/ (setq ln (length l)) n)
                  ((lambda (j)
                         (repeat j
                               (setq x (cons (nth (setq ln (1- ln))  l)
                                             x) )))
                        n)
                  (setq ls (cons x ls)
                        x  nil)
                  ))
      ls)

(_relist '(1 2 3 4 5 6 7 8 9 10) 1)
((1) (2) (3) (4) (5) (6) (7) (8 ) (9) (10))
(_relist '(1 2 3 4 5 6 7 8 9 10) 2)
((1 2) (3 4) (5 6) (7 8 ) (9 10))
(_relist '(1 2 3 4 5 6 7 8 9 10) 3)
nil
(_relist '(1 2 3 4 5 6 7 8 9 10) 4)
nil
(_relist '(1 2 3 4 5 6 7 8 9 10) 5)
((1 2 3 4 5) (6 7 8 9 10))