I have imported the parser implementation to the repository:
http://svn.wikimedia.org/svnroot/mediawiki/trunk/parsers/libmwparser
Dependencies:
* antlr snapshot. Be sure to apply the patch to the C runtime.
* libtre. Regexp library for wide character strings. (Not actually
used yet.)
There is no php integration yet.
Below is a list of cases I'm awaro of where the behavior differs from
Parser.php. (libmwparser doesn't actually output html at the moment,
but in the below examples I've converted the traces to html in the
obvious way for comparison.)
- Definition lists:
;; item
Parser.php: <dl><dt></dt><dl><dt> item
</dt></dl></dl>
libmwparser: <dl><dl><dt> item</dt></dl></dl>
- Html/table attributes:
{| id='a class='b'
| col1
|}
Parser.php: <table class='b'><tbody><tr><td> col1
</td></tr></tbody></table>
libmwparser: <table><tbody><tr><td> col1
</td></tr></tbody></table>
(libmwparser does not backtrack to the space character to try to find
a valid attribute, it just considers id='a class='<junk characters> to
be garbage altoghether.)
- libmwparser restricts some block elements tokens to the correct
block contexts.
- inline formatting:
<b>'''bold'''</b>
Parser.php: <b><b>bold</b></b>
libmwparser: <b>bold</b>
- long term formatting is applied to all inline text:
<i>text
{|
| col1
|}
text</i>
Parser.php:
<p><i>text</i></p><table><tbody><tr><td>
col1
</td></tr></tbody></table><p><i>text</i></p>
libmwparser:
<p><i>text</i></p><table><tbody><tr><td><i>
col1</i></td></tr></tbody></table><p><i>text</i></p>
- internal links are treated as long term formatting:
[[Link|text
{|
| col1
|}
text]]
Parser.php: <p><a
href="...">text</p><table><tbody><tr><td> col1
</td></tr></tbody></table><p>text</a></p>
libmwparser: <p><a
href="...">text</a></p><table><tbody><tr><td><a
href="...">
col1</a></td></tr></tbody></table><p><a
href="...">text</a></p>
- In general, any case that cause Parser.php to generate invalid html is
likely to differ in libmwparser.
Some benchmarking:
The performance isn't very impressive.
I've tried very quickly to make a comparison:
Parser.php:
* Mediawiki 1.15.0 running on a 2.2GhZ AMD Opteron 275
* I'm measuring from just before internalParse to right after
doBlockLevels.
libmwparse:
* 2.5GhZ core 2 duo
* The time for outputting the traces to /dev/null is included
128kB of plain text:
Parser.php: 170ms
libmwparser: 180ms
The page
http://en.wikipedia.org/wiki/Wikipedia (templates not
installed at the mediawiki test server) size 124kB
Parser.php: 720ms
libmwparser: 190ms
As expected, Parser.php will take more time the more markup on the
page, while libmwparser maintains a fairly constant pace.
/Andreas