Re: Class Selectors Extension Proposals

Alberto Pacheco wrote:

> Tacus ( is a presentational
> language based on CSS (and is part of ExpoVision system)  where the user can
> define macros like:
> "@1()=bic(red,white)"
> If we have the macro-call: "@1(blue)" it is expanded to: "bic(blue,white)"

I failed to learn much from the document that you referenced, so my understanding of 
Tacus and of ExpoVision comes only from your message to www-style.  In any case, 
without meaning to give offense, it is not the job of the CSS community, much less of the  
W3C, to solve ExpoVision problems.

As I understand ExpoVision, users are allowed to create arbitrary markup and arbitrary 
style macros, but not plain CSS rule sets.  And that is the real problem.  Trying to style 
documents of arbitrary structure is a futile task; the author of a style sheet should be 
familiar with the markup.  In ExpoVision it is the user who is familiar with the markup and 
so it is the user who should write the style sheet.

> Note: Is impractical to define all posible user styles for any Tacus
> presentation document

So let the user define the styles as appropriate for the user.  The user already has the 
ability to write macros; why not give the user the ability to write whole style sheets?

> The dilemma is: To give the user a set of pre-defined styles (like classes
> "i" and "b") but to give him/her freedom to use his/her favorite/personal
> style attributes values (like he/she did with colors of class "c")

This seems like a great opportunity for the separatist approach: clean, semantically rich 
markup paired with a collection of thoughtful style sheets.

I would not first ask how to get a 'span' element to have blue text, but rather what the 
blue means.  Why should that element have that presentation?  Once we know the 
fundamental meaning we can write the proper markup, choosing element types or 
classes to match the meaning.  When the structure is known, it is then a simple step to 
write a basic style sheet for general application to the given class of documents and to 
let users write their private style sheets.

Etan Wexler <>

Received on Tuesday, 4 June 2002 15:11:48 UTC