写一个lisp 函数ssget选择 选择圆和闭合的LWPOLYLINE,POLYLINE

在LISP中，你可以创建一个函数来过滤特定类型的几何对象，如圆（CIRCLE）和闭合的线框（LWPOLYLINE或POLYLINE）。这里是一个简单的示例函数，假设你正在使用一种基于 Common Lisp 的图形库，比如 Alexandria 或 ECL：

(defun ss-get-closed-lwpolyline-or-polylines (geom-list)
  "选择并返回只包含圆和闭合线框的列表."
  (let ((filtered-geoms '()))
    (dolist (geom geom-list)
      (when (or (and (typep geom 'circle) (closed-polygon? geom))
                (typep geom 'lwpolyline) (closed-polygon? geom))
        (push geom filtered-geoms)))
    filtered-geoms))

(defun closed-polygon? (polygon)
  "检查给定的线框是否封闭（所有顶点相连形成闭环）"
  (every #'(lambda (pair) (= pair (first pair))) polygon-points polygon))

; 示例用法：
(let ((shapes '(CIRCLE :center (point 0 0) :radius 5
                    LWPOLYLINE :vertices '((0 0) (5 0) (5 5) (0 5))
                    POLYGON :vertices '((1 1) (4 1) (4 4) (1 4)))))
  (ss-get-closed-lwpolyline-or-polylines shapes)))