[audreyt]

Although similar in expressive power, Colm offers instruction logging to auto-reverse global state changes upon backtracking, something Perl 6 grammars does not (yet) support; at the moment we need to manually manage them with embedded blocks.

[chocolateboy]

Re: "reverse global state changes upon backtracking": this sounds similar to the (manual) "undo actions" supported by the Kelbt parser [1], perhaps unsurprisingly as it was developed by the same author :-)

[1] http://www.complang.org/kelbt/

[colomon]

Thanks!