Editing Regular expression (section)

===Possessive matching===
In Java and Python 3.11+,<ref>[https://github.com/python/cpython/issues/34627/ SRE: Atomic Grouping (?>...) is not supported #34627]</ref> quantifiers may be made ''possessive'' by appending a plus sign, which disables backing off (in a backtracking engine), even if doing so would allow the overall match to succeed:<ref name=es-re>{{cite web |title=Essential classes: Regular Expressions: Quantifiers: Differences Among Greedy, Reluctant, and Possessive Quantifiers |url=https://docs.oracle.com/javase/tutorial/essential/regex/quant.html#difs |website=The Java Tutorials |publisher=[[Oracle Corporation|Oracle]] |access-date=23 December 2016 |archive-date=7 October 2020 |archive-url=https://web.archive.org/web/20201007183203/https://docs.oracle.com/javase/tutorial/essential/regex/quant.html#difs |url-status=live}}</ref> While the regex <code>".*"</code> applied to the string

"Ganymede," he continued, "is the largest moon in the Solar System."

matches the entire line, the regex <code>".*+"</code> does {{em|not match at all}}, because <code>.*+</code> consumes the entire input, including the final <code>"</code>. Thus, possessive quantifiers are most useful with negated character classes, e.g. <code>"[^"]*+"</code>, which matches <code>"Ganymede,"</code> when applied to the same string.

Another common extension serving the same function is atomic grouping, which disables backtracking for a parenthesized group. The typical syntax is {{mono|1=(?&gt;group)}}. For example, while {{mono|1=^(wi{{!}}w)i$}} matches both {{mono|wi}} and {{mono|wii}}, {{mono|1=^(?&gt;wi{{!}}w)i$}} only matches {{mono|wii}} because the engine is forbidden from backtracking and so cannot try setting the group to "w" after matching "wi".<ref>{{cite web |title=Atomic Grouping |url=https://www.regular-expressions.info/atomic.html |website=Regex Tutorial |access-date=24 November 2019 |archive-date=7 October 2020 |archive-url=https://web.archive.org/web/20201007183204/https://www.regular-expressions.info/atomic.html |url-status=live}}</ref>

Possessive quantifiers are easier to implement than greedy and lazy quantifiers, and are typically more efficient at runtime.<ref name=es-re/>