Lisp 在一行上漂亮地打印对象

Question

我正在将列表的列表写入 .dot 文件以生成树。 lisp 中的 pretty-print 似乎在输出中插入了新行，因此当我执行点文件时，新行使得生成的图形难以读取。

我查看了format 文档，但我还不能很好地利用它。

这是一个应该打印的示例列表:

(((TOWER 'D 'C ^LEFT '0 ^RIGHT '2 ^BOTTOM '4 ^TOP '8)
  (TOWER 'C 'B ^LEFT '0 ^RIGHT '2 ^BOTTOM '2 ^TOP '6)
  (TOWER 'B 'A ^LEFT '0 ^RIGHT '2 ^BOTTOM '0 ^TOP '4) (ON 'D 'C)
  (ON 'C 'B) (ON 'B 'A))
 ((TOWER 'D 'C ^LEFT '0 ^RIGHT '2 ^BOTTOM '4 ^TOP '8)
  (TOWER 'C 'B ^LEFT '0 ^RIGHT '2 ^BOTTOM '2 ^TOP '6)
  (TOWER 'B 'A ^LEFT '0 ^RIGHT '2 ^BOTTOM '0 ^TOP '4) (ON 'D 'C)
  (ON 'C 'B) (ON 'B 'A))
 ((TOWER 'D 'C ^LEFT '0 ^RIGHT '2 ^BOTTOM '4 ^TOP '8)
  (TOWER 'C 'B ^LEFT '0 ^RIGHT '2 ^BOTTOM '2 ^TOP '6)
  (TOWER 'B 'A ^LEFT '0 ^RIGHT '2 ^BOTTOM '0 ^TOP '4) (ON 'D 'C)
  (ON 'C 'B) (ON 'B 'A))
 ((TOWER 'D 'C ^LEFT '0 ^RIGHT '2 ^BOTTOM '4 ^TOP '8)
  (TOWER 'C 'B ^LEFT '0 ^RIGHT '2 ^BOTTOM '2 ^TOP '6)
  (TOWER 'B 'A ^LEFT '0 ^RIGHT '2 ^BOTTOM '0 ^TOP '4) (ON 'D 'C)
  (ON 'C 'B) (ON 'B 'A))
 ((TOWER 'D 'C ^LEFT '0 ^RIGHT '2 ^BOTTOM '4 ^TOP '8)
  (TOWER 'C 'B ^LEFT '0 ^RIGHT '2 ^BOTTOM '2 ^TOP '6)
  (TOWER 'B 'A ^LEFT '0 ^RIGHT '2 ^BOTTOM '0 ^TOP '4) (ON 'D 'C)
  (ON 'C 'B) (ON 'B 'A))
 ((TOWER 'D 'C ^LEFT '0 ^RIGHT '2 ^BOTTOM '4 ^TOP '8)
  (TOWER 'C 'B ^LEFT '0 ^RIGHT '2 ^BOTTOM '2 ^TOP '6)
  (TOWER 'B 'A ^LEFT '0 ^RIGHT '2 ^BOTTOM '0 ^TOP '4) (ON 'D 'C)
  (ON 'C 'B) (ON 'B 'A)))

下面是列表如何打印到文件中:

(((TOWER 'D 'C
^LEFT '0
^RIGHT '2
^BOTTOM '4
^TOP '8)
(TOWER 'C 'B
^LEFT '0
^RIGHT '2
^BOTTOM '2
^TOP '6)
(TOWER 'B 'A
^LEFT '0
^RIGHT '2
^BOTTOM '0
^TOP '4)
(ON 'D 'C)
(ON 'C 'B)
(ON 'B 'A))
((TOWER 'D 'C
^LEFT '0
^RIGHT '2
^BOTTOM '4
^TOP '8)
(TOWER 'C 'B
^LEFT '0
^RIGHT '2
^BOTTOM '2
^TOP '6)
(TOWER 'B 'A
^LEFT '0
^RIGHT '2
^BOTTOM '0
^TOP '4)
(ON 'D 'C)
(ON 'C 'B)
(ON 'B 'A))
((TOWER 'D 'C
^LEFT '0
^RIGHT '2
^BOTTOM '4
^TOP '8)
(TOWER 'C 'B
^LEFT '0
^RIGHT '2
^BOTTOM '2
^TOP '6)
(TOWER 'B 'A
^LEFT '0
^RIGHT '2
^BOTTOM '0
...
...
...

应该使用什么 format 指令来获得正确格式化的输出？

这是我正在使用的代码

(format stream "~A [shape=record, label=\"{~A|~A|~A}\"];~%" a b c d)

Answer 1

如果你设置*print-right-margin*对于非常大的数字， pretty-print 不应该插入任何换行符。

它默认为 nil 表示设备(例如，您的显示器)的宽度。