This is from MarpaX::Demo::JSONParser, right? That gives you a choice
of two grammars, and if you chose mine, it was written for benchmarking
with long input strings, so I wasn't optimizing for repeated parses of
short strings. There's also Peter Stuifzand's grammar, and Peter's
intentions were probably more practical.
MarpaX::Demo::JSONParser is now Ron Savage's module, so if you're
interested in changes to it, you should talk to Ron.
--jeffrey
On 01/18/2014 03:00 AM, Ruslan Shvedov wrote:
Is it intended that the JSON grammar is not reused? The script would 2
times faster if it were.
On Thu, Jan 16, 2014 at 8:53 PM, Jeffrey Kegler
<jeffreykeg...@jeffreykegler.com
<mailto:jeffreykeg...@jeffreykegler.com>> wrote:
$naif_recce->value() is being called to parse the JSON grammar, as
opposed to the JSON itself. Note that with short strings, as in
your examples, start-up costs play a greater role. -- jeffrey
On 01/16/2014 08:26 AM, rns wrote:
Devel::NYTProf says that both scripts spend much time in
Marpa::R2::Recognizer::value — is it expected with ASF's?
sl_json_asf
Calls P F Exclusive
Time Inclusive
Time Subroutine
13 1 1 203ms 272ms Marpa::R2::Recognizer::value
sl_json_no_trace
Calls P F Exclusive
Time Inclusive
Time Subroutine
26 1 1 231ms 312ms Marpa::R2::Recognizer::value
1152 1 1 105ms 152ms
Marpa::R2::Internal::Grammar::add_user_rule
On Thursday, January 16, 2014 5:55:55 PM UTC+2, rns wrote:
I once thought that traversing ASF's can be a faster way of
doing semantics because ASF's /value() /is not called
(actions are not applied) and grammar can be absolutely
syntactic, so I decided to try it with /sl_json.t/ from Marpa
test suite (latest dev version, cygwin, 5.14.2).
Changes made to original sl_json.t from the test suite
removed tracing test and code
Writing semantics via ASF is like this: first I got the
default action that produced results as Perl data structure,
dumped with YAML to see what's there as needed and then added
handlers via if/else. AST semantics is easier because many
handlers can be left to default.
Changes made to the grammar after converting semantics to ASF
remove all action adverbs
removed events and changed read()/resume() loop to just
read()
removed round brackets around literals
removed bless_package
The net result is that sl_json_asf.t
<https://gist.github.com/rns/8456567> is a bit slower than
sl_json_no_trace.t <https://gist.github.com/rns/8456626> when
measured with /time/ and is equal within 2-3% when quickly
and dirtily Benchmark-ed [1]. So, now it looks like Perl
overhead over libmarpa is pretty much constant across all
ways of doing semantics in Marpa::R2.
Is it as expected or I missed something?
I'm thinking about cheaper ASF traversing like the low-level
synopsis code in Marpa::R2::Glade. Makes sense?
Good news, though, is that ASF semantics is not much slower,
if a bit harder to write.
[1]
use Benchmark qw{ cmpthese };
cmpthese(500, {
'json_asf' => q{ eval `cat sl_json_asf.t` },
'json_no_trace' => q{ eval `cat sl_json_no_trace.t` },
});
--
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 marpa-parser+unsubscr...@googlegroups.com
<mailto:marpa-parser+unsubscr...@googlegroups.com>.
For more options, visit https://groups.google.com/groups/opt_out.
--
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 marpa-parser+unsubscr...@googlegroups.com
<mailto:marpa-parser%2bunsubscr...@googlegroups.com>.
For more options, visit https://groups.google.com/groups/opt_out.
--
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 marpa-parser+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.
--
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 marpa-parser+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.
