Unclear text in the UBA (UAX#9) of Unicode 6.3

Eli Zaretskii eliz at gnu.org
Mon Apr 21 03:01:13 CDT 2014


> From: James Clark <jjc at jclark.com>
> Date: Mon, 21 Apr 2014 08:54:34 +0700
> Cc: Eli Zaretskii <eliz at gnu.org>, unicode at unicode.org, Kenneth Whistler <ken at unicode.org>
> 
> >    X6. For all types besides B, BN, RLE, LRE, RLO, LRO, PDF, RLI, LRI,
> >        FSI, and PDI:
> >
> >        . Set the current character’s embedding level to the embedding
> >          level of the last entry on the directional status stack.
> >
> >     [...]
> >
> >    Note that the current embedding level is not changed by this rule.
> >
> > What does this last sentence mean by "the current embedding level"?
> > The first bullet of X6 mandates that "the current character’s
> > embedding level" _is_ changed by this rule, so what other "current
> > embedding level" is alluded to here?
> >
> >  I'm punting on that one - can someone else answer this?
> >
> 
> I assume "current embedding level" here meant "the embedding level of the
> last entry on the directional status stack".

Thanks, that was my guess as well, but I wanted to be sure.

IMO, the unfortunate wording here is that the same phrase ("current
embedding level") was used just before the problematic sentence to
mean something completely different.  Having identical phrases close
to one another always tricks readers into thinking they are describing
the same thing; when they aren't, confusion settles in.  So I would
suggest to reword one or both of these references to the "current
embedding level".

Btw, why is that note, about the current embedding level not being
changed by X6, important?  Why would someone mistakenly think the
contrary?



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