S-expression的使用

解析(a (b c))
+----+------+-------+
|LIST|list=o|next=o--->NULL
+----+-----|+-------+
           |
   +-------+
   |
   v
+-----+-------+-------+  +----+------+-------+
|VALUE|val="a"|next=o--->|LIST|list=o|next=o--->NULL
+-----+-------+-------+  +----+-----|+-------+
                                    |
                         +----------+
                         |
                         v
                     +-----+-------+-------+  +-----+-------+-------+
                     +VALUE|val="b"|next=o--->|VALUE|val="c"|next=o--->NULL
                     +-----+-------+-------+  +-----+-------+-------+

(note: o---> represents a pointer)

上图转自：http://sexpr.sourceforge.net/

s-expression用于对字符串中信息的提取。