Hi João! I have adjusted the code according to your advise and the FAQ and it is now working for me. Here is the update: //---------------- cpp_code_block_text = anychar_p-(ch_p('{')|ch_p('}')); cpp_code_block_begin_p = ch_p('{'); cpp_code_block_end_p = ch_p('}'); cpp_code_block_p = cpp_code_block_begin_p >> *(cpp_code_block_p|cpp_code_block_text) >> cpp_code_block_end_p; At the first sight the boost::spirit seems to be difficult to use but with more experience I recognize that it is realy nice/good tool. Thank you João. On 17/01/06, João Abecasis <jpabecasis@gmail.com> wrote:
Hi!
elviin wrote:
I created this parser and it is working for me except the detail:
[snip code]
And the problem is in repeat_p (0, 100). I'd like to use * instead but it does not work for me because the parser runs forever. 100 means the number of blocks cpp_code_block_p or cpp_code_block_text.
Where is the problem?
The code sample you provided can be summarized as
continuation = *(anychar_p - (begin|end)); all = begin >> *continuation >> end;
Which, substituting continuation, is the same as:
all = begin >> *(*(anychar_p - (begin|end))) >> end;
The problem here is the double kleene star. The outer kleene will continue matching, in an infinite loop, as long as the inner one returns matches -- even if they're zero matches. Btw, this is a FAQ and is addressed here http://tinyurl.com/art36.
When you substitute the outer * for repeat_p(0, 100) you only limit the loop. You still get 100 matches, even if they're all empty.
The solution is pretty simple, and it is to remove one of the */repeat_p. For instance,
continuation = *(anychar_p - (begin|end)); all = begin >> continuation >> end;
Best regards,
João
_______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users