Visualize tree like data in Lisp

Published on 4月 28, 2012

lisp中的特殊列表结构

  • 点状列表
  • pair
  • circular list

可视化lisp数据

用graphviz把lisp中数据可视化的方法,代码如下:

    ;;切换到工作目录
    (cd "/home/reverland/Documents/lisp/")
    ;;;有向图
    ;;定义节点及描述
    (defparameter *wizard-nodes* '((living-room (you are in the living-room.
                             a wizard is snoring loudly on the couch.))
                       (garden (you are in a beautiful garden.
                        w
                           )
                    (attic (you are in the attic. there
                        is a giant welding torch in the corner.)))))
    ;;定义节点与边
    (defparameter *wizard-edges* '((living-room (garden west door)
                    (attic upstairs ladder))
                       (garden (living-room east door))
                       (attic (living-room downstairs ladder))))
      ;;转换名函数
    (defun dot-name (exp)
     (substitute-if #\_ (complement #'alphanumericp) (prin1-to-string exp)))
      ;将非字母数字的字符转化为下划线 
      ;;定义标签长度
    (defparameter *max-label-length* 30)
      ;;处理位置描述
    (defun dot-label (exp)
     (if exp
      (let ((s (write-to-string exp :pretty nil))); :pretty防止换行或加入tab
       (if (> (length s) *max-label-length*)
        (concatenate 'string 
         (subseq s 0 (- *max-label-length* 3)) "...")
        ;如果标签长度比最长值长,将超长的替换成...
        s))
      ""));strange,why not nil?
      ;;定义节点和标签函数
    (defun nodes->dot (nodes)
     (mapc (lambda (node);mapc不返回列表
        (fresh-line)
        (princ (dot-name (car node)))
        (princ "[label=\"")
        (princ (dot-label node))
        (princ "\"];"))
      nodes))
      ;;定义遍历edges中每个元素,再对每个元素进行遍历
      (defun edges->dot (edges)
       (mapc (lambda (node)
          (mapc (lambda (edge)
             (fresh-line)
             (princ (dot-name (car node)))
             (princ "->")
             (princ (dot-name (car edge)))
             (princ "[label=\"")
             (princ (dot-label (cdr edge)))
             (princ "\"];"))
           (cdr node)))
        edges))
      ;;生成dot文件内容
    (defun graph->dot (nodes edges)
     (princ "digraph{")
     (nodes->dot nodes)
     (edges->dot edges)
     (princ "}"))
      ;;接受一个trunk,得到trunk的输出而非函数的值
      ;;to keep this dot->png function as reusable as possible, the graph->dot
      ;;function isn’t called directly. Instead, we write dot->png to accept a thunk
    (defun dot->png (fname thunk)
     (with-open-file (*standard-output*;类比与let
              fname ;输入到fname文件
              :direction :output;keyword symbol即本身,方向输出
              :if-exists :supersede);如果存在覆盖
      (funcall thunk));nully function
     (ext:shell (concatenate 'string "dot -Tpng -O " fname)))
    ;it's an O actually!it's not zero!
    ;;最后一步
    (defun graph->png (fname nodes edges)
     (dot->png fname
      (lambda ();relay funcion
       (graph->dot nodes edges))));which is the trunk,I am not clear.
      ;;最后执行
      (graph->png "wizard.dot" *wizard-nodes* *wizard-edges*)
      ;;;无方向图
    (defun uedges->dot (edges)
     (maplist (lambda (lst);遍历剩下的元素
           (mapc (lambda (edge)
              (unless (assoc (car edge) (cdr lst));除非以下不再出现这个位置
               (fresh-line)
               (princ (dot-name (caar lst)))
               (princ "--")
               (princ (dot-name (car edge)))
               (princ "[label=\"")
               (princ (dot-label (cdr edge)))
               (princ "\"];")))
            (cdar lst)))
      edges))
    (defun ugraph->dot (nodes edges)
     (princ "graph{")
     (nodes->dot nodes)
     (uedges->dot edges)
     (princ "}"))
    (defun ugraph->png (fname nodes edges)
     (dot->png fname
      (lambda ()
       (ugraph->dot nodes edges))))
      ;;执行命令
      (ugraph->png "uwizard.dot" *wizard-nodes* *wizard-edges*)

结合上回处理文本,觉得lisp在处理列表和文本时挺方便,虽然没有正则什么的。然后学习到lisp和unix环境交互还是比较方便的。

学会了一个生成文本数据的技术,把打印到终端而易于调试的输出包装成一个thunk,传递给其它函数。

学到了很多命令:

  • cd(ext)
  • substitute-if
  • complement
  • alphanumericp
  • write-to-string
  • subseq
  • mapc
  • maplist
  • with-open-file
  • funcall