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Re: Case Sensitivity in CSS [I18N-ACTION-171]

From: John Daggett <jdaggett@mozilla.com>
Date: Wed, 16 Jan 2013 01:25:41 -0800 (PST)
To: "CSS WWW Style (www-style@w3.org)" <www-style@w3.org>
Cc: WWW International <www-international@w3.org>
Message-ID: <2002801610.11974407.1358328341941.JavaMail.root@mozilla.com>

Tab Atkins wrote:

> > Huh?  Counters are matched case sensitively across all user agents
> > now.  ASCII case insensitivity is used for situations where an ASCII
> > keyword is matched, which is a different case altogether from a
> > user-defined string.  An author can use whatever casing they like for
> > their own identifiers, what huge utility is there to caseless matching
> > of these identifiers that warrants introducing a *third* type of case
> > matching to web platform?!?
> 
> This was established very early on, at the last f2f: using CS matching
> for user idents makes it confusing when you mix language-defined and
> user-defined idents in the same namespace, such as custom property
> names and counter-style names.

I don't see any discussion about this specific point in the minutes of
the last F2F [1], nor the one before that [2].  Maybe there was a telcon
during June/July you're thinking about?  You and fantasai put together
a wiki page where you note this point:

  http://wiki.csswg.org/topics/custom-ident-case-sensitivity

>From that page:

  So, we resolved to make user-defined identifiers (like
  counter-names and namespace prefixes) case-sensitive to
  avoid dealing with Unicode case-folding and other
  complications.

  This is fine for things that are entirely user-defined,
  like counters and namespace prefixes, but Tab noticed that
  it presents a problem when we get to counter-styles: all
  our styles right now are predefined keywords, and are thus
  case-insensitive ASCII. When we use @counter-style to
  define counter styles, we will be allowing users to create
  their own counter styles. Will those be case-sensitive?
  What if the user redefines an existing counter-style?

I think you can have case sensitive user identifiers and still match
existing keywords case insensitively.  I don't see that as being that
confusing to authors.  The flip side is if you make counters match
case insensitively, why don't class names match case insensitively?
They are both completely user defined.  That seems more incongruent
for those just learning CSS.  Other than keyword matching, CSS is
already mostly case sensitive, as is HTML5. In the case of user
defined identifiers, users can pick any casing style they desire, I
don't see a strong use case for introducing a third type of case
sensitivity to the web platform as a whole, which is effectively
what you're proposing.

Regards,

John

[1] http://lists.w3.org/Archives/Public/www-style/2012Nov/0263.html
[2] http://lists.w3.org/Archives/Public/www-style/2012Aug/0899.html
Received on Wednesday, 16 January 2013 09:26:11 GMT

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