RP's output is the same as ParseTree's output: s-expressions using ruby's arrays and base types.
RP的输出与语法分析树的输出相同：用ruby中的数组以及基本类型来表达的s-expression。
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In my opinion, the density of Perl 5's regular expressions is one of the reasons why the language is so powerful, while at the same time fairly hard to maintain.
Regular expressions: search word (s) will be regarded as a regular expression (in keyword search words will be treated as a sequence of regular expressions).