Boost C++ Libraries: Ticket #13080: Boost Xpressive ignores capture placeholders

status changed; resolution set

Eric Niebler — Thu, 22 Jun 2017 21:34:32 GMT

status new → closed
resolution → invalid

After the match, m has no sub_matches. It does, however, have nested results that correspond to the nested regexes in uri_re. Please read [^1] for more information.

[^1]: http://www.boost.org/doc/libs/1_64_0/doc/html/xpressive/user_s_guide.html#boost_xpressive.user_s_guide.grammars_and_nested_matches.nested_regexes_and_sub_match_scoping

Thu, 22 Jun 2017 22:34:14 GMT

Thank you, overlooked indeed. A bit unexpected though.

Any way to flatten the matching results? Breaking into set of regexps, here, should be considered as simplifying final expression for human reading, not declaring any recursive grammars.

Thu, 22 Jun 2017 22:36:26 GMT

Addition, I see that iterating through tree gives the flatten view over nested results, I am mostly about keeping original index based syntax, where s1= .. match will be accessed via m[1] index later on.

Eric Niebler — Thu, 22 Jun 2017 23:34:20 GMT

It can't. There could be a 0^th submatch in two nested regexes. They would stomp each other. The nested_results keeps them separate.