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Message-ID:  <4E596725.5050900@morningstar2.co.uk>
Date:         Sat, 27 Aug 2011 22:52:37 +0100
Reply-To: Mailing list for the LaTeX3 project
              <LATEX-L@listserv.uni-heidelberg.de>
Sender: Mailing list for the LaTeX3 project <LATEX-L@listserv.uni-heidelberg.de>
From: Joseph Wright <joseph.wright@MORNINGSTAR2.CO.UK>
Subject: Re: couple of l3keys notes
To: LATEX-L@listserv.uni-heidelberg.de
In-Reply-To:  <dscoakqlizrv$.dlg@nililand.de>
Precedence: list
Status: R

On 23/08/2011 18:29, Ulrike Fischer wrote:
>>> So keys like "fig / encoding" look quite natural, but it would be
>>> quite useful if a user could set keys also like this:
>>>
>>> set-all, family=...
>>>
>>> set-fig, family=...  , size= ...
> 
>> At a technical level, this can be supported. However, my concern is more
>> at the conceptual level. In most programming languages, keyval input is
>> used to replace positional parameters by named ones. On the other hand,
>> the pgfkeys approach inter-mixes named parameters with executed items.
> 
> chessboard is doing it too. Once I got the knack on defining keys it
> came quite naturally to use them not only to set width or size but
> also to put and remove pieces, declare a color in one key, and with
> the next key draw a rule in this color.
> 
> I realized only at the end that this was an quite unusual use of
> keyval syntax. 
> 
> A "change path" command would be really useful here. Currently every
> key must have an unique name, and this can give quite long names. 
> 
> 
>> At present, the approach in l3keys when setting keys is rather more
>> toward the 'named parameters' approach.
> 
> This is also the case with xkeyval and it could be used for the
> other approach too ;-) I think l3keys is very powerful and quite fun
> to use. 

I suspect that we may want the 'executable' key idea, for example .cd,
at some stage. This plus '.style' is part of why pgfkeys works so well.
I will probably look to add this in as experimental stuff to l3keys at
some stage (soon-ish).
--
Joseph Wright