Marpa::R2's SLIF only supports the character class part of Perl's RE's: https://metacpan.org/pod/distribution/Marpa-R2/pod/Scanless/DSL.pod#Character-classes
The SLIF has its own mechanisms for doing the equivalent of lookahead. One in particular is pre-lexeme events: https://metacpan.org/pod/distribution/Marpa-R2/pod/Event.pod#Pre-lexeme-events On Sun, Dec 13, 2015 at 2:25 PM, Thomas Weigert <[email protected]> wrote: > Dear all, > > I am struggling with which parts of Perl's regular expression syntax is > supported in lexeme rules and which are not. For example, I was trying to > write a simple rule with zero-width look ahead, but marpa does not like it: > > PICSINGLEDOT ~ [.](?=\.) > > The manual seems to imply that whatever is in Perl is ok, but that seems > far from true. > > Does anybody have any guidance to offer here? > > Thanks, Th. > > -- > You received this message because you are subscribed to the Google Groups > "marpa parser" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "marpa parser" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
