regex

Balancing groups (?<name>) and (?<-name>) turn a .NET regex capture group into a stack, so one pattern can match arbitrarily nested parentheses or <div> tags. The full pattern, how the stack works, inner-content capture with (?<inner-open>), and the gotchas verified on .NET 11 RC1: the empty-stack check, catastrophic backtracking, NonBacktracking, and mixed bracket types.

A complete guide to converting new Regex(pattern, RegexOptions.Compiled) into [GeneratedRegex] in .NET 11: the mechanical rewrite, partial methods vs partial properties, measured startup and throughput numbers, the SYSLIB1040-1045 diagnostics, and the two patterns where the generator silently falls back to a cached Regex.

.NET 11 Preview 3 adds RegexOptions.AnyNewLine so ^, $, \Z, and . recognize every Unicode newline sequence, including \r\n, NEL, LS, and PS, with \r\n treated as one atomic break.