This is a little suspicious: /(:?aaa)?/ ...because /(?:aaa)?/ would be non-capturing parentheses. What you have instead is a capturing parenthesis expression that begins with an optional colon. Is that what you meant?

As to your question, your entire expression is optional (i.e., /(aaa)?/), so it doesn't really require Perl to match anything. In my little fooling around, I didn't find a way to get it to find the optional string while still keeping it optional, but there probably is a way.

In reply to Re: Regex: succeeds, but parens don't collect... by kyle
in thread Regex: succeeds, but parens don't collect... by Wiggins

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