* This routine attempts to rewrite the DOM to maximize tag overlap
and thus minimize tag uses.
* This takes as input a set of tags which participate in the
minimization.
* Tested on the following example
<b><i><u><s>BIUS</s></u></i></b><b><i><s>BIS</s></i></b><b><u><s>BUS</s></u></b><u><i>UI</i></u>
with multiple combinations of the 2^4 possible variations of i,b,u,s
tags: [], ['i','b','u','s'], ['i'], ['b','s'], ['i','b','u']
- But, I am not fully sure if this implements the right behavior when
only a subset of inline tags are provided. Needs discussion and tweaking
as necessary.
* Also tested on few others:
<b>B</b><b><i>BI</i></b><b><i><u>BIU</u></i></b><b><i><u><s>BIUS</s></u></i></b>
<s><i><b>SIB</s></i></b><s><i><u>SIU</u></i></s><i><u>IU</u></i><i>I</i>
* The previous pairwise tag rewriting version fails on several of these
examples, so this new version is a definite improvement.
* No change in parserTests run (203 passing before and after).
* Possible improvements that could/should be undertaken:
- get rid of useless/idempotent add/remove of nodes that don't change
the DOM.
- ensure that node attributes post-restructuring are correct.
Change-Id: Ib4a8b39583fa96a2be880a77021ca81cefa06484
- This is implemented as a post-processing pass.
- Might require additional checks to verify rewriteability.
- Implemented as a pair-wise tag DOM minimization strategy,
i.e. it takes tag pairs (B, I) for ex, and attempts to
normalize the tree just for those tag pairs. Normalizing
across multiple tags is implemented as pairwise rewriting
across all pairs: Ex:(b,i), (b,u),(i,u) for (b,i,u)
- Copied over attributes as part of rewriting, but some of the
attributes lose their meaning on rewriting since tags are
reordered (ex: sourcePosn, sourceTagPosn). How do we handle this?
Output examples and possible issues to fix:
<i><b><u>biu</u></b></i><b><u>bu</u></b><u>u</u>
gets rewritten to:
<u><b><i>biu</i>bu</b>u</u>
But, the equivalent wikitext form:
'''''<u>biu</u>''''''''<u>bu</u>'''<u>u</u>
does not get rewritten because of parsing differences.
This wikitext gets parsed into:
<i><b><u>biu</u>'''</b></i><u>bu<b>u</b></u>
The extra ''' token in the middle thwarts DOM rewriting.
However, a slightly different version:
"'''''<u>biu</u>''<u>bu</u>'''<u>u</u>"
gets properly normalized to:
<u>'''''biu''bu'''u</u>
An alternative, but fun strategy to play with is to use the following
two normalization primitives: S(wap) and M(erge).
- S rewrites T1(T2(x)) into T2(T1(x))
(ex: <b><i>foo</i></b> ==> <i><b>foo</b></i>)
- M rewrites (T(x),T(y)) into (T(x,y)).
(ex: <b>foo</b><b>bar</b> ==> <b>foobar</b>)
The current rewriting strategy could possibly be re-implemented as S-M
rewriting. The problem to solve there would be to find an efficient
rewriting strategy that is guaranteed to lead to a normal form. I may
not play with it now, but just documenting it for later (to play with
in my spare time).
This commit is just as a record of fun/experimental code where I get to
learn details of JS, wikitext, parsing, and DOM manipulation. Next
version of this code will attempt to introduce minimal DOM restructuring
across multiple tags at once which can be more efficient.
gwicke: Removed now passing test from whitelist, and updated another whitelist
entry which is now improved.
Change-Id: Ie97bcb164eb62c34ba61aa76ba2f4c232aa713d8
* All parser pipelines including tokenizer and DOM stuff are now constructed
from a 'recipe' data structure in a ParserPipelineFactory.
* All sub-pipelines of these can now be cached
* Event registrations to a pipeline are directly forwarded to the last
pipeline member to save relatively expensive event forwarding.
* Some APIs for on-demand expansion / format conversion of parameters from
parser functions are added:
param.to('tokens/expanded', cb)
param.to('text/wiki', cb) (this does not work yet)
All parameters are additionally wrapped into a Param object that provides
method for positional parameter naming (.named() or conversion to a dict
(.dict()).
* The async token transform manager is now separated from a frame object, with
the frame holding arguments, an on-demand expansion method and loop checks.
* Only keys of template parameters are now expanded. Parser functions or
template arguments trigger an expansion on-demand. This (unsurprisingly)
makes a big performance difference with typical switch-heavy template
systems.
* Return values from async transforms are no longer used in favor of plain
callbacks. This saves the complication of having to maintain two code paths.
A trick in transformTokens still avoids the construction of unneeded
TokenAccumulators.
* The results of template expansions are no longer buffered.
* 301 parser tests are passing
Known issues:
* Cosmetic cleanup remains to do
* Some parser functions do not support async expansions yet, and need to be
modified.
Change-Id: I1a7690baffbe8141cadf67270904a1b2e1df879a
serialized into a single data-mw-rt attribute if present. Update parserTests
to ignore this attribute for comparisons with expected parser output.
A few more tweaks and notes are thrown into this commit too. 233 tests are
passing now.
html markup handling.
* Remove global 'use strict' declarations from html5 parser.
* Add trailing whitespace handling in dt
Overall, 55 parser tests are now passing.
