What you have in your example is a simple "left-most match wins" behavior, which is common to both NFA and DFA engines (and their variants): the match that begins earliest wins.

In Perl 6, you have two types of alternations (with || and |): one in which the order of the regex alternates matter, and one in which the longest match wins, but, even then, that applies only to matches that start on the same atom; you still have with both alternation variants the overriding rule that it is the match that begins earliest which wins.

Perl (and PCRE) has had an NFA engine for very long, and I don't think there has been any change to that.

The mere fact that you can have lazy (or frugal or non-greedy) quantifiers is an almost certain proof that it is a traditional NFA engine, because they are just not possible with a DFA engine.

In reply to Re: Is RegEx in Perl not NFA anymore? by Laurent_R
in thread Is RegEx in Perl not NFA anymore? by redbull2012

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