Re: fail on osx between 2/4/2009 and 2/5/2009

[YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>]

>>>>> On Thu, 12 Feb 2009 20:42:42 +0200, Adrian Robert <adrian.b.robert@gmail.com> said:

> When I first implemented the Cocoa font back-end, the list and match  
> APIs were mainly based around the font-entity structure, which  
> contained the following information:

> foundry, family, adstyle, registry, weight, slant, width, size, dpi,  
> spacing, avgwidth

Both the list and match are designed to take a font spec and returns
either font entities or a font entity.  So the knowledge of font specs
as well as font entities were necessary to implement them properly in
the first place.

> Display of characters in multiple scripts was handled by the existing  
> emacs "fontset" structure.  The "kludge" Yamamoto Mitsuharu refers to  
> was designed to allow this mechanism to work under NS without the  
> user or distributor needing to manually define a font set.  It works  
> reasonably well, judging by the HELLO screen.  Of course, users /  
> distributors always had the option to fall back to manual fontset  
> definitions to get better results as in other emacsen.

Also, the existence of script-representative-chars you used in the
kludge implies there were already some mechanisms such as the :script
property in the font specs for selecting appropriate fonts without
needing manual definition of fontsets.  You could have noticed that if
you read the implementations of other font backend drivers.

In general, you should consider/propose platform-independent ways of
solving problems/adding features rather than doing that by adding
platform-specific kludges, unless they are inherently
platform-specific matters.  Such kludges might be acceptable for
unofficial distributions, but not for the official Emacs distribution,
I think.

				     YAMAMOTO Mitsuharu
				mituharu@math.s.chiba-u.ac.jp