New syntax » Named capture comparison

There are several different syntaxes in the wild for named capture, and although Python was the first to implement the feature, most libraries have adopted .NET's alternative syntax. The following comparison chart includes every regex library with named capture support that I am aware of. It is included to highlight the differences and similarities of named capture in XRegExp and libraries you might already be familiar with. XRegExp's syntax is listed first.

Library	Capture	Backref in regex	Backref in replacement	Stored at	Backref numbering
XRegExp	`(?<name>⋯)`	`\k<name>`	`${name}`	`result.name`	Sequential
.NET	`(?<name>⋯)` `(?'name'⋯)`	`\k<name>` `\k'name'`	`${name}`	`matcher.Groups('name')`	Unnamed first, then named
Perl 5.10	`(?<name>⋯)` `(?'name'⋯)` `(?P<name>⋯)`	`\k<name>` `\k'name'` `\k{name}` `\g{name}` `(?P=name)`	`$+{name}`	`$+{name}`	Sequential
PCRE 7.2	`(?<name>⋯)` `(?'name'⋯)` `(?P<name>⋯)`	`\k<name>` `\k'name'` `\k{name}` `\g{name}` `(?P=name)`	N/A		Sequential
PCRE 7	`(?<name>⋯)` `(?'name'⋯)` `(?P<name>⋯)`	`\k<name>` `\k'name'` `(?P=name)`	N/A		Sequential
PCRE 4	`(?P<name>⋯)`	`(?P=name)`	N/A		Sequential
Python	`(?P<name>⋯)`	`(?P=name)`	`\g<name>`	`result.group('name')`	Sequential
Oniguruma 1.8.4	`(?<name>⋯)` `(?'name'⋯)`	`\k<name>` `\k'name'`	`\k<name>` `\k'name'`	N/A	Unnamed groups default to noncapturing when mixed with named groups
Java 7	`(?<name>⋯)`	`\k<name>`	`${name}`	`matcher.group('name')`	Sequential
JGsoft	`(?<name>⋯)` `(?'name'⋯)` `(?P<name>⋯)`	`\k<name>` `\k'name'` `(?P=name)`	`${name}` `\g<name>`	N/A	.NET and Python styles, depending on capture syntax
Boost.Regex	`(?<name>⋯)` `(?'name'⋯)`	`\k<name>` `\g{name}`	?	?	?
RE2	`(?P<name>⋯)`	N/A			?
JRegex	`({name}⋯)`	`{\name}`	`${name}`	`matcher.group('name')`	?

XRegExp

The one of a kind JavaScript regular expression library

New syntax » Named capture comparison