Polyglot::Regexen

A module to enable use of non-Raku flavors of regex directly in Raku code.

Why?

Because copy and paste. Also, there are lots of little gotchas when going between different flavors. What counts for \s, \d, ., or even $ can vary substantially or in quite subtle ways. If you have a battle-tested regex, don't worry about rewriting it. Just use it as is!

The goal of this module is to provide a variety of ways for you to use your favor flavors in Raku scripts — even in grammars!
When using regexen from this module, you can be assured that capture ordering is preserved, the meaning of whitespace won't get changed, etc.

Support

The support for different flavors is shown below in a table, followed by a discussion on any (hopefully temporary) deviations from the standard. The meaning of the columns is the following:

• In grammars: these can be used inside of grammars. Just declare the regex with the psuedo-adverb. Since } will necessarily be the terminating character, you may need to escape it in some way.
• Bare quoted: just as you can use rx/foo/ for regular regexes, these allow you to prefix with, e.g., rx:ecma/foo/
• Lexical scope: these are defined by my/our scoping, e.g. my regex:ecma { … }

Flavor	In grammars	Bare quoted (substitution)	Lexical scoped	adverb
ECMA-262 (Javascript)	✓	✓ (𐄂)	✓	ecma
Python	𐄂	𐄂 (𐄂)	𐄂	py
Ruby	𐄂	𐄂 (𐄂)	𐄂	ruby
PHP	𐄂	𐄂 (𐄂)	𐄂	php

(At the moment, only Javascript is supported. The others are aspirational.)

Support Caveats

• General

  • Non-slash delimiters are not currently planned

• ECMA-262 (Javascript)

  • Not all options are currently available (right now, just s, m, and i).
  • In block form (defined with regex:ecma { … }, leading and trailing white space is ignored).
  • To add options in block form, use a colon: regex:ecma:i { … }
  • Unicode option is effectively always on. More testing will be required to tease out if/when that makes a difference

Version History

• v0.0.1
  • Fixed ECMA262 positional match counting
  • Added support for named back references in ECMA262
  • RakuAST-ified for much better maintenance
  • Reorganized tests and added many new and detailed tests
  • Changed naming convention
• v0.0.1 * Initial public release with most of ECMA262 (JavaScript) regex supported