Mimick atomic grouping and possessive quantifiers with capturing LookAheads.
Embeds validly-named capturing groups and references, Java 7-style ((?<name>expr) and (\k<name>)).
Group name simplifier for Flavors that support limited group names.
Prevents usage of local mode modifiers (NCG flags like (?-i:sub-expression))
Prevents usage of LookAround.
Prevents usage of LookBehind.
Prevents usage of Unicode categories.
Prevents usage of Unicode: single characters, categories.
Translates a Possessive quantifier into a Greedy one wrapped into an AtomicGroup: a++ becomes (?>a+).
Strips inline-named capturing groups and references, Java 6-style ((expr) and (\n)).
․NET flavor
Java ≤ 6 Flavor.
Java ≥ 7 Flavor.
Vanilla JavaScript / ECMA-262 flavor, with very limited Unicode support
Legacy Ruby <= 1․8 flavor, which does not support Unicode (at all) nor LookBehind.
PCRE Flavor (C, PHP, Ruby 1.