W3C home > Mailing lists > Public > www-style@w3.org > April 1996

'legal' / 'important' and cascading order

From: Chris Lilley <Chris.Lilley@sophia.inria.fr>
Date: Mon, 22 Apr 1996 15:49:01 +0200
Message-Id: <199604221349.PAA29780@www47.inria.fr>
To: rieger@bse.de (Wolfgang Rieger)
Cc: www-style@w3.org
Wolfgang Rieger writes:
 > The following example shows a problem connected with the use of
 > 'legal'or 'important' and the cascading order:
 > 
 > Example:
 > 
 > Rule 1:
 > 
 > spec1 { prop1 : value1 !important;
 > 	prop2 : value2; }
 > Rule 2:
 > 
 > spec2 { prop1 : value1;
 > 	prop2 : value2 !important; }
 > [...]
 > However, IMHO there is no big use in being able to specify weight on
 > the declaration level. As far as I can see, it would be sufficient to
 > specify weight on the rule level. 

Yes, in effect

 > In this case, one would have instead
 > of the example given above the following rules:
 > 
 > spec1 { prop1 : value1; !important }
 > spec1 { prop2 : value2; }
 > spec2 { prop1 : value1; }
 > spec2 { prop2 : value2; !important }

Surely this can be generated very easily (without placing the
semicolon before the ! ) from the foregoing. In other words, one
performs a sort of macro expansion preprocessing step such that

  sel { decl1; decl2; decl3 }

expands to the exactly equivalent

  sel {decl1 }
  sel {decl2 }
  sel {decl3 }

Where sel is some selection term and decl is some declaration
property: value plus optional !weight.

[ Whether a particular implementation actually performs this step or
simply behaves as if it had been done, is of course up to the
implementor. Thus, a semicolon could be taken to mean, write the
current selector and the current declaration (property, value, weight)
into the internal table, retain the current selector, and continue. ]

Advantage: the formal grammar need not be changed. People can still
write the short forms.

I believe this macro expansion concept was proposed earlier in
connection with the font shorthand notation, although I cannot find
the reference at present.

--
Chris Lilley, W3C                          [ http://www.w3.org/ ]
http://www.w3.org/people/chris/                       INRIA/W3C
chris@w3.org                       2004 Rt des Lucioles / BP 93
+33 93 65 79 87            06902 Sophia Antipolis Cedex, France
Received on Monday, 22 April 1996 09:52:31 GMT

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