;**************************************
    ; Name: asc-list-sorter
    ; Description:This program accepts a lis
    ;     t of as*ociation lists and searches the 
    ;     lists retrieving the elements that the u
    ;     ser specifies. The program then takes th
    ;     ese elements and places them in a two el
    ;     ement list, the first element in the lis
    ;     t is the element identifier (e.g. 8 for 
    ;     layer name) and the second element in th
    ;     e list is a list of the element 8's data
    ;     for all of the as*ociation lists searche
    ;     d. If the user specifies, duplicate entr
    ;     ies will be deleted from the list. I hav
    ;     e included a commented out test function
    ;     with this code so that you can run it an
    ;     d see exactly how the code functions.
    ; By: Greg Whitaker
    ;
    ; Inputs:1) a list of association lists 
    ;     (NOTE: if using entity data lists for th
    ;     ese the -1 and 330 elements must be remo
    ;     ved because they contain invalid cdrs).
    2) a list of sort elements to retrieve the data for. For example, say you want to retrieve the 0,8 and 11 elements from a list of entity lists, you would simply supply this list '(0 8 11).
    3) A boolean to tell the program whether to remove duplicate elements or not. Supply a "t" if you would like the duplicates elements removed or a "nil" if you would like them left in the lists.
    ;
    ; Returns:This program returns a list of
    ;     lists. Each list within the master list 
    ;     has the same format which is as follows:
    ;     (sort element (list of data retrieved fo
    ;     r that sort element from the as*ociation
    ;     lists)). For example if I was collecting
    ;     the number 8 element from a set of two e
    ;     ntity data lists that had differing laye
    ;     r names, "girt" and "purlin", this progr
    ;     am would return the following: ((8 ("gir
    ;     t" "purlin")))
    ;
    ; Assumes:This program assumes that it i
    ;     s being supplied correct association lis
    ;     ts. That means if you are supplying enti
    ;     ty data lists that contain the -1 and 33
    ;     0 elements that you would get from makin
    ;     g a call to entget, the program will not
    ;     function correctly. You must remove the 
    ;     -1 and 330 elements beforing supplying t
    ;     hem to this function.
    ;
    ;This code is copyrighted and has    ; limited warranties.Please see http://w
    ;     ww.Planet-Source-Code.com/vb/scripts/Sho
    ;     wCode.asp?txtCodeId=59&lngWId;=13    ;for details.    ;**************************************
    
    (defun asc-list-sorter (alists sort-list remove-duplicates? / master-list tmp-lst match nlist)
    (setq tmp-lst (list))
    (foreach sorter sort-list
    (foreach lst alists
    (foreach element lst
    	(if (equal (car element) sorter)
    	 (setq tmp-lst (append tmp-lst (list (cdr element))))
    	 )
    	)
    )
    (if remove-duplicates?
    (setq tmp-lst (remove-duplicates tmp-lst))
    )
    (if master-list
    (setq master-list (append master-list (list (list sorter tmp-lst))))
    (setq master-list (list (list sorter tmp-lst)))
    )
    (setq tmp-lst (list))
    )
    master-list
    )
    (defun remove-duplicates (lst / nlist match)
    (foreach element lst
    (if nlist
    (progn
    	(setq match nil)
    	(foreach mbr nlist
    	 (cond ((null match)
    		 (if (equal element mbr)
    		(setq match t)
    		)
    		 )
    		)
    	 )
    	(if (null match)
    	 (setq nlist (append nlist (list element)))
    	 )
    	)
    (setq nlist (list element))
    )
    )
    nlist
    )
    ; Test function to give you an example o
    ;     f how this program works
    ; 
    ;(defun c:test ()
    ; (asc-list-sorter '(((0 . "LINE") (5 . 
    ;     "2B") (100 . "AcDbEntity") (67 . 0) (410
    ;     . "Model") (8 . "0")
    ;		 (100 . "AcDbLine") (10 4.02739 2.978
    ;     62 0.0) (11 10.8895 5.92974 0.0) (210 0.
    ;     0 0.0 1.0))
    ;		 ((0 . "TEXT") (5 . "2B") (100 . "AcD
    ;     bEntity") (67 . 0) (410 . "Model") (8 . 
    ;     "GIRT")
    ;		 (100 . "AcDbLine") (10 4.02739 2.978
    ;     62 0.0) (11 10.8895 5.92974 0.0) (210 0.
    ;     0 0.0 1.0))
    ;		 ((0 . "LINE") (5 . "2B") (100 . "AcD
    ;     bEntity") (67 . 0) (410 . "Model") (8 . 
    ;     "PURLIN")
    ;		 (100 . "AcDbLine") (10 4.02739 2.978
    ;     62 0.0) (11 10.9999 5.92974 0.0) (210 0.
    ;     0 0.0 1.0))
    ;		 )
    ;'(0 8 11)
    ;t)
    ; )