On Sun, Dec 27, 2009 at 01:30:18AM -0800, Ovid wrote: > > my $config = Config::Tiny::Grammar.parse($text); > #say $config ?? 'yes' || 'no'; > say $config.perl; >
> Currently this matches, but if I add a \s* before the final \n > in the section token, it fails to match. I don't know why > this is and I'm unsure of how to debug Perl 6 regexes. Any \s* will end up matching the final \n, and since quantifiers in tokens default to "non backtracking", \s* \n in a token will always fail. (In P5, it'd be like "(?>\s*)\n".) Perhaps \h* \n would do what you want here? Alternatively, you can force backtracking by using \s*! instead. The new version of Rakudo (the "ng" branch) provides a debugging mode that provides some tracing of the grammar as its matching. I don't know that it would've found the above yet -- it still needs some work. > my $config = Config::Tiny::Grammar.parse($text); > #say $config ?? 'yes' || 'no'; > say $config.perl; > > Also, if I uncomment that 'say $config ??' line, I get the > following strange error: > > ResizablePMCArray: Can't pop from an empty array! > in Main (file <unknown>, line <unknown>) It's a parsing error in Rakudo at the moment -- it *should* be telling you that it found a '??' but no '!!'. Again, the new version (arriving in a week or so) should be better about such messages. Pm
