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Re: XSL Errata document updated

From: Nikolai Grigoriev <grig@renderx.com>
Date: Sat, 26 Oct 2002 12:41:42 +0400
Message-ID: <005001c27ccb$84e71fe0$7f01000a@grig>
To: <www-xsl-fo@w3.org>
Cc: <xsl-editors@w3.org>

Paul,

> It is true that src="url('TH0317A.jpg')" would probably 
> make a better example. 

A strange thing: by the letter of the spec, this expression
should be deemed as invalid. The only production in Section 5.9
of the spec that matches is [3] Function Call; and, as you have
correct;y noticed, 'url' is not a valid function name. Looks like
the strict interpretation of the spec makes double quoting
obligatory.

> However, I believe src="'url(TH0317A.jpg)'" should 
> also be valid.  The double quotes are just part of being 
> an XML attribute, and then the single quotes make the 
> attribute value a string.  The uri-specification datatype 
> says it's a sequence of characters, so a string should be 
> a valid value, ...

Let's see what happens if we apply this approach to <integer> 
data type. A quote from XSL Rec, [5.11. Property Datatypes]:

XSL>  <integer>
XSL>    A signed integer value which consists of an optional 
XSL>    '+' or '-' character followed by a sequence of digits. 

An integer is defined to be _a sequence of digits_; the valid 
syntax to set column-count to 1 is therefore column-count="'1'". 
Looks like integers should also be additionally quoted :-).

The overall impression is that the respective part of the spec
is still underdeveloped: XPath-like expression syntax is mixed
to CSS data types, but no tight integration was made. Data type 
definitions in Section 5.11 (copied from CSS) refer to the string 
representation of data tokens as if there were no expressions 
at all: there is no information about mapping of productions 
in 5.9 to property data types. 

Therefore, I am inclined to believe that extra quotes shall be
excluded in both integers and URIs. "'url(...)'" is a Literal
whose value is 'url(...)'; it naturally maps to <string> datatype
that is a different datatype fom <uri-specification>. Unless
a conversion is explicitly permitted by the spec, these two 
should be kept separate.

Best regards,
Nikolai Grigoriev
RenderX
Received on Saturday, 26 October 2002 04:42:59 GMT

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