[Fontconfig] matching multiple families in <alias> and <test>

[Raimund Steger]

Akira TAGOH wrote:
> On Thu, May 3, 2012 at 9:48 AM, Raimund Steger<rs at mytum.de>  wrote:
>> [...]
>>
>> i. e. prepend/append occurs around the leftmost/rightmost actually matching
>> family of the list that was specified in the original pattern.
>
> Aha. that looks reasonable to me. particularly if the result is
> considered as the intersection of the given pattern and the string
> sets in<test>.

Right, that was the word :-)
But I don't think it's a good idea anymore, because I can't think of any 
way to consistently deal with "assign" edits then.

>> What I can also think of (at least for<alias>), is to not use FcOpComma,
>> but create as many FcTest objects (and add all of them with FcConfigAddEdit)
>> in FcParseAlias as there are families in the upper part of<alias>, thus
>> simulating what a user would do creating separate rules for all of them.
>
> Sure. that would be an idea though, as it's documented,<alias>  has to
> be kept as a syntactic sugar. so needs to change the behavior of
> FcOpComma then.

True, it's not a good approach to invalidate existing user-knowledge 
about the relationship of <alias> and <match>.

Maybe when going through the FcOpComma operands, one could tag the 
matching FcValueList's somehow and loop precisely over them for the 
following prepend/append/assign edits.

Raimund