- From: Jonathan Kew <jfkthame@gmail.com>
- Date: Wed, 10 Sep 2014 09:59:16 +0100
- To: www-style@w3.org
On 10/9/14 08:37, Tab Atkins Jr. wrote: > On Tue, Sep 9, 2014 at 6:16 PM, John Daggett <jdaggett@mozilla.com> wrote: >> Tab Atkins wrote: >>>> For example, I don't see any reason why the two pieces of markup >>>> below should be shaped differently: >>>> >>>> <span>A</span><span>W</span> >>>> <sup>A</sup><sup>W</sup> >>>> >>>> I don't see any reason why the kerning applied between the letters >>>> in adjacent spans should not be used between adjacent superscript >>>> elements. >>> >>> Because they're effectively different words, semantically. And >>> this is far more than kerning - you don't want those two to >>> ligaturize, or affect character shapes in Arabic, etc. >> >> I don't really see how "semantically" different somehow implies >> coalescing can occur in one case but not in another. Worse, using a >> presentation attribute like 'vertical-align' is a poor way to infer >> that somehow inlines are distinct. >> >> Example - a simple 1px bump in the baseline breaks kerning and ligatures: >> >> .shift-up span { vertical-align: 1px; } >> >> <p><span>A</span><span>W</span> <span>f</span><span>i</span></p> >> <p class="shift-up"><span>A</span><span>W</span> <span>f</span><span>i</span></p> >> >> Why should kerning and ligatures be used in one of these but not the other? >> >> I don't think there's any real use case that you're solving by >> introducing this "non-baseline values of vertical-align disables >> coalescing" rule. In the absence of a real need, CSS should strive >> to avoid special-case rules like this that complicate >> implementations unnecessarily and result in odd behavior for authors. > > There is a very real need. Words sometimes have multiple > superscripts. In languages where it matters, these should not join. > For example, say you have multiple footnotes at one point, and you're > using letters as footnote indicators, like foo^ABC in English. In > Arabic, each of the letters should be using the "isolated" shape, but > if superscripts aren't automatically a break, they'll instead form a > word, with A, B, and C being in initial/medial/final shapes instead; > it'll look nonsensical. I don't find this very convincing. If there are multiple superscripts, they would/should normally be separated or delimited somehow, in English just as much as in Arabic; I'd expect to see commas between them, or a thin space, or something like that. Consider the case of numeric superscripts: Does foo<sup>1</sup><sup>2</sup><sup>3</sup> mean foo^{123} or foo^{1,2,3}? ISTM it should mean the latter. Something like sup + sup::before { content: ','; } could achieve this, and a similar approach would be equally applicable to alphabetic superscripts, whether English or Arabic. JK
Received on Wednesday, 10 September 2014 08:59:45 UTC