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Quantifiers and Backtracking: Greedy, Lazy, Possessive and Atomic Groups

A greedy quantifier first takes all it can and gives characters back one by one when the rest of the pattern fails; a lazy one takes little and adds one at a time, yet both spend steps searching for the delimiter, and the correct and fastest option is usually a negated class. We compare greedy, lazy, possessive and atomic groups with PCRE2 step counts and extract endpoint, status and duration from Bookstore's access log with .NET, JavaScript and sed.