From: Curtis Clark (firstname.lastname@example.org)
Date: Thu Mar 31 2005 - 14:31:40 CST
I am not arguing against encoding chemical bonds, and I think Jukka
raises some good points, but it's not all that simple.
on 2005-03-31 09:29 Jukka K. Korpela wrote:
> 1. It is illogical to use characters with fairly definite semantics
> for something completely different.
Of course it is. It also happens all the time, as we all recently
noticed with the visual ambiguation of apostrophe and right quote in
English, say, but not in French. I think the semantic argument is the
strongest for encoding these bonds, but it certainly doesn't end the
> 2. The glyphs are not of the same width except by accident, but the
> meaning of bond symbols would rather naturally call for glyphs
> of the same width.
The bonds themselves are not of the same length. They vary based on the
atoms bonded, the type of bond, the number of bonds, and the nature of
atoms adjacent to the atoms bonded. I point this out simply to
empphasize that making the glyphs the same width is *purely* a
typographic decision, and has nothing to do with the underlying semantics.
> 3. The glyphs for the four characters are not very suitable for
> use as bond symbols. They should be wider. Or, to put it
> milder, the bond symbols should be coded separately to _allow_
> font design that makes them wider, or otherwise different
> from em dash etc.
This is IMO the second-strongest argument for separate encoding. The
other side of the coin, though, is that virtually all fonts already
contain glyphs that can be used for single and double bonds, and many
fonts already include the triple. If the bonds are disambiguated from
the existing signs, it will take a while for them to appear in fonts,
which will mean even more documents that use the old methods.
Another argument *for* encoding the bonds is that they can be given the
same properties, and be treated the same wrt word breaks and such (I
could make an argument that they should be non-breaking, since the
semantics of a chemical formula strongly support keeping it in one piece).
-- Curtis Clark http://www.csupomona.edu/~jcclark/ Web Coordinator, Cal Poly Pomona +1 909 979 6371 Professor, Biological Sciences +1 909 869 4062
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