list challenge
Always integers only, and always in order? Would there ever be more than one of the same integer value included?
I'm on a no-AutoCAD computer, so I can't check, but does that assume their original list is always going to start with 0, or that if it doesn't, they want all the slots from 0 up covered? That is, given a list like:
'(12 14 15 17)
wouldn't it return:
(nil nil nil nil nil nil nil nil nil nil nil nil 12 nil 14 15 nil 17)
? And what if there are any negative numbers?
@Moshe-A , do you want only the positions within the range of your original numbers? If so, and for a list of integers only [including negative], maybe something like [untested]:
(defun nilgaps (lst / n result)
(repeat (- (setq n (1+ (apply 'max lst))) (apply 'min lst))
(setq result (cons (if (member (setq n (1- n)) lst) n nil) result))
)
)
That [if it works...] would not require a list already in numerical order, but would sort the list in the process. However, it would not account properly for multiple instances of the same integer in the source list, if that's a possibility.
EDIT: Tested now, and it works for me, including the self-sorting and negative-number aspects.
(defun hak_vz:fillnil (lst / ret a b)
(setq lst (vl-sort lst '<) a (1-(car lst) ) b (last lst) ret (list))
(while (<= (setq a (1+ a)) b)(if (not (member a lst)) (setq ret (append ret (list nil)))(setq ret (append ret (list a)))))
)Command: (HAK_VZ:FILLNIL '(3 5 8))
(3 nil 5 nil nil 8)
Command: (HAK_VZ:FILLNIL '(6 2 7 2))
(2 nil nil nil 6 7)Miljenko Hatlak
Did your question get successfully answered? Then click on the ACCEPT SOLUTION button.
That has the same issue as @john.uhden 's if the list doesn't include 0 -- it reaches down that far anyway:
Command: (:niltomissing '(8 10 15 17))
(nil nil nil nil nil nil nil nil 8 nil 10 nil nil nil nil 15 nil 17)
And it doesn't like negative numbers [it only reaches down as far as 0]:
Command: (:niltomissing '(-3 0 2))
(0 nil 2)
Mine is made to handle those situations:
Command: (nilgaps '(8 10 15 17))
(8 nil 10 nil nil nil nil 15 nil 17)
Command: (nilgaps '(-3 0 2))
(-3 nil nil 0 nil 2)
And sorts for itself -- you can give it an unsorted list:
Command: (nilgaps '(-95 -92 -97))
(-97 nil -95 nil nil -92)
I have written my code at 2 am. I left my computer turned on, checked the forum and stayed to write the code.
What I didn't get from @Moshe-A : do list has to start with 0 or with smallest list member? Are there duplicates and negative values? Code can be optimized and we have here some nice solutions.
Miljenko Hatlak
Did your question get successfully answered? Then click on the ACCEPT SOLUTION button.
@ВeekeeCZ wrote:
...You know that it's simple to fix.
(defun :niltomissing (o / n i) (repeat (- (setq i (1+ (last o))) (car o)) (setq n (cons (car (member (setq i (1- i)) o)) n))))Btw, your result needs to be localized.
That's the same approach to the range of values as mine, except for requiring the list to be sorted in order [which maybe it always will be -- we haven't heard back from the OP on that].
And yes, I realized at the time of my last Reply that the result should be localized, and had put that in. But that may not be true if such a function becomes incorporated into a larger operation, depending on what that is, what use is to be made of the result, and whether it will be needed to feed into something other function or routine and maybe should be localized there instead.
