vl-sort (AutoLISP)

(vl-sort list comparison-function)

Arguments

list

Any list.

comparison-function

A comparison function. This can be any function that accepts two arguments and returns T (or any non-nil value) if the first argument precedes the second in the sort order. The comparison-function value can take one of the following forms:

• A symbol (function name)
• '(LAMBDA (A1 A2) ...)
• (FUNCTION (LAMBDA (A1 A2) ...))

Return Values

A list containing the elements of list in the order specified by comparison-function. Duplicate elements may be eliminated from the list.

Examples

Sort a list of numbers:

(vl-sort '(3 2 1 3) '<)
(1 2 3)

Note that the result list contains only one 3.

Sort a list of 2D points by Y coordinate:

(vl-sort '((1 3) (2 2) (3 1))              (function (lambda (e1 e2)                          (< (cadr e1) (cadr e2)) ) ) )
((3 1) (2 2) (1 3))

Sort a list of symbols:

(vl-sort    '(a d c b a)    '(lambda (s1 s2)     (< (vl-symbol-name s1) (vl-symbol-name s2)) ) )
(A B C D)       ;  Note that only one A remains in the result list