Ruby是否支持条件正则表达式 [英] Does Ruby support conditional regular expressions

问题描述

只是一个语言功能问题，我知道有很多方法可以在正则表达式之外（或具有多个正则表达式）进行操作。

Just a language feature question, I know there's plenty of ways to do this outside of regexes (or with multiple regexes).

红宝石支持条件正则表达式？基本上，是一个正则表达式中的IF-THEN-ELSE分支，其中IF的谓词是表达式中捕获的组的存在（或不存在）。

Does ruby support conditional regular expressions? Basically, an IF-THEN-ELSE branch inside a regular expression, where the predicate for the IF is the presence (or absense) of a captured group in the expression.

在perl中，语法为（？（predicate）yes-pattern | no-pattern），如

In perl, the syntax is (?(predicate)yes-pattern|no-pattern) as in

/(?:y|(x))(?(1)y|x)/

在浏览过的任何ruby文档中，我都找不到与之类似的引用，但我想我要在这里确保，以防万一我正在搜索

I haven't been able to find any reference to anything like it in any ruby docs that I've browsed, but I figured I'd ask here to make sure, in case I was searching for the wrong words, or it was elided from the docs.

推荐答案

不，ruby不支持（在1.8和1.9中都不支持）

No, ruby does not support that (neither in 1.8 nor 1.9).

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