"Jukka K. Korpela" <jk******@cs.tut.fiwrites:
Scripsit Jon Fairbairn:
>Actually there's already a kind of collapsing of characters
in some browsers (using some rendering engines): some
character pairs (fi for example) are displayed as ligatures
(fi).
Well, it's a quite different kind of collapse, isn't it,
Indeed.
but this makes me curious: which browsers do such things,
for which character combinations?
I'm using
firefox Mozilla/5.0 (X11; U; Linux x86_64; en-GB;
rv:1.8.1.12) Gecko/20080208 Fedora/2.0.0.12-1.fc7
Firefox/2.0.0.12 On Fedora. I think it uses pango.
But it seems I was mistaken. What fooled me was that if I
type into a text area the spacing of the characters changes
suddenly once one of the fi fl ffi ffl combinations is
entered. This is disconcerting, so I looked closely and saw
something that looked like a ligature. As far as I can tell
it doesn't do this in page bodies.
>I don't think we would want to mandate that that didn't
happen either.
That's debatable. I might want that. For example, if I write
my E-mail address, I don't want any wowser to display the
".fi" part using an "fi" ligature.
It's not clear to me what the problem with that is, as long
as selecting the text gave you the right sequence of
characters (and perhaps something clever happened to permit
selection without the final i, though I can't see why that
would be what someone really wanted).
Generally, use of ligatures (at least for Latin
characters) would be something _unexpected_.
No, I don't think so. I saw it because I was expecting it!
In printed typography, use of ligatures is the norm; the
ligatures are used simply to improve appearance -- eg "fi"
either looks too spaced out or the dot on the top of the "i"
crashes into the kern of the f.
So I think ligature rendering should be off by
default. But this is (at least currently) a quality of
implementation issue, not something required *n HTML specs.
That's what I meant by not mandating that it doesn't
happen. It's certainly the sort of thing that a user might
turn off, but (as long as it was done right), I think the
HTML (or CSS) specs shouldn't say that it mustn't be done.
If you want ligatures, you can explicitly ask for them using
a control character or, more effectively, replacing a
sequence of characters by a compatibility character
representing their ligature, such as fi.
The trouble with that is that it turns a presentation issue
into content. If my site is called "Waffle shop" I might
reasonably hope that (given a capable output device) the ffl
is displayed as nicely as possible, but I certainly want a
user to get 11 characters if they copy and paste it, and I
want it to match those eleven characters in web searches.
--
Jón Fairbairn
Jo***********@cl.cam.ac.uk