Comments on: Stream-based Parsing Made Easy

By: Sehe

Sehe — Tue, 17 May 2011 00:40:32 +0000

Note that it is slow; I have ran this comparison (1000x repeated parses of about 60 different files <100k, boost 1.46.1/Spirit 2042 and fully optimized release builds):

#if 1 std::string contents = read(spec); return do_parse_attempt(contents.begin(), contents.end(), handler); #else std::ifstream in(spec.c_str()); in.unsetf(std::ios::skipws); // No white space skipping!


    // wrap istream into iterator

    boost::spirit::istream_iterator begin(in);

    boost::spirit::istream_iterator end;

return do_parse_attempt(begin, end, handler); #endif

(read() defined below)

The copying/allocating version (using the read() helper) was done in 6.1s, the spirit::istream_iterator version in 10.9s

That is with read(…) defined as braindead:

std::string read(const std::string& spec) { std::ifstream in(spec.c_str()); in.unsetf(std::ios::skipws); std::string storage; std::copy( std::istream_iterator(in), std::istream_iterator(), std::back_inserter(storage)); return storage; }

By: Hartmut Kaiser

Hartmut Kaiser — Fri, 22 Jan 2010 16:16:45 +0000

Mark,

the release schedule is all I can refer to only as well. But I know that beta1 has been posted today, so it seems we’re still on schedule.

Regards Hartmut

By: Mark Jarvin

Mark Jarvin — Fri, 22 Jan 2010 15:45:33 +0000

When is Boost 1.42 due to be released? Am I right in guessing early February 2010? I’m extrapolating from here: http://www.boost.org/community/review_schedule.html

Thanks!

By: Hartmut Kaiser

Hartmut Kaiser — Fri, 15 Jan 2010 19:41:34 +0000

Felix,

The only reason why these have not been ported yet is that nobody invested time doing it .
But these iterators are still usable with Spirit 2.x (even if they live in namespace spirit::classic), so there is no real rush to port/rewrite them.

Regards Hartmut

By: Felix

Felix — Fri, 15 Jan 2010 19:21:41 +0000

The input stream iterator is definitely a useful feature.
What about other Classic Spirit iterators?
Is there a reason why File Iterator and Position Iterator are not part of Sprit 2.x?

By: Hartmut Kaiser

Hartmut Kaiser — Tue, 05 Jan 2010 22:54:07 +0000

Thanks Marshall! I added this to the code above.

Regards Hartmut

By: Marshall

Marshall — Tue, 05 Jan 2010 21:01:57 +0000

Helpful bit:

#include