Here is an explanation by the author (Jeffrey) -- http://irclog.perlgeek.de/marpa/2015-05-19#i_10626590 -- fell free hang on IRC to get more info.
On Fri, Nov 20, 2015 at 10:07 AM, Cev Ing <[email protected]> wrote: > Am Donnerstag, 19. November 2015 20:25:19 UTC+1 schrieb rns: >> >> [a-zA-Z0-9_]+ is a quantified rule RHS and it just needs its own LHS as >> you did above with identifier_extend, otherwise it is a SLIF DSL syntax >> error. >> >> Note that RHS primary can't be a quantified character class -- there are >> quantified rules for that -- >> https://metacpan.org/pod/distribution/Marpa-R2/pod/Scanless/DSL.pod#Quantified-rule >> <https://www.google.com/url?q=https%3A%2F%2Fmetacpan.org%2Fpod%2Fdistribution%2FMarpa-R2%2Fpod%2FScanless%2FDSL.pod%23Quantified-rule&sa=D&sntz=1&usg=AFQjCNE2elwoh6QgqnUMdydmPV0KdA17ig> >> > > I already have learned this limitation. > > On Thu, Nov 19, 2015 at 11:07 AM, <[email protected]> wrote: >> >>> The following grammar part works fine: >>> >>> limited_identifier ~ [a-zA-Z_] identifier_extend >>> identifier_extend ~ [a-zA-Z0-9_]+ >>> >>> >>> But this one throws the error: >>> >>> limited_identifier ~ [a-zA-Z_] [a-zA-Z0-9_]+ >>> >>> >>> For me there is no difference. But there seems to be a difference for >>> Marpa. >>> >>> What is the difference? >>> >> > The question is why does this limitation exist, because it looks a bit > odd. As far as I know lexing is normally done by regular expressions. And > regular expression typically do not have such a limitation. So where does > it come from? > > > -- > 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.
