[Fwd: ]

["Peter B. West" <pb...@powerup.com.au>]

Fellow FOPs,

I just sent this enquiry to the XSL editors.

Peter


The editors,

I am puzzled by aspects of the datatype <string>.

Section "5.9 Expressions" has

"All property value specifications in attributes within an XSL
stylesheet can be expressions."

This persuades me that I should be able to pass every raw value from an
attribute on an FO element to the expression parser.

Section "5.9.8 Strings" has

"Strings are represented either as literals or as an enumeration token.
All properties contexts allow conversion from enumeration tokens to
strings."

(On the other hand, the discussion of <string> in 5.11 Property
Datatypes has only "<string>  A sequence of characters," which caused me
a great deal of distress.)

5.9.11 Lexical Structure
   Expression Lexical Structure
has
[26]   EnumerationToken   ::=   NCName

So, if I understand this correctly, a <string> is either an NCName or a
literal.

There are two properties on which <string> is defined, which I cannot
reconcile with this understanding.


7.8.2 font-family, has

'<family-name>
      The name of a font-family of choice. In the previous example [in
the CSS2 Recommendation], "Baskerville", "Heisi Mincho W3", and "Symbol"
are font families. Font family names containing whitespace should be
quoted. If quoting is omitted, any whitespace characters before and
after the font name are ignored and any sequence of whitespace
characters inside the font name is converted to a single space.'

'<generic-family>
      The following generic families are defined: "serif", "sans-serif",
"cursive", "fantasy", and "monospace". Please see the section on generic
font families for descriptions of these families. Generic font family
names are keywords, and therefore must not be quoted.'

...

'XSL modifications to the CSS definition:

'<string>
      The names are syntactically expressed as strings.'

I am assuming that the "names" referred to in the comment on <string>
are both <family-name>s and <generic-family>s.  <generic-family> values
look more like enumeration tokens than keywords, and Expression Lexical
Structure in 5.9.11 Lexical Structure, has

[24]   Keyword   ::=   'inherit'

as the only instance of a keyword.

However, <family-name> does not fit into an NCName/literal definition
because the font family names may be unquoted and yet contain whitespace
characters, and be enclosed in whitespace.


7.28.1 content-type
'<string>

      'A specification of the content-type in terms of either a mime-type
or a namespace.

      'A mime-type specification has the form "content-type:" followed by
a mime content-type, e.g., content-type="content-type:xml/svg".

      'A namespace specification has the form "namespace-prefix:"
followed by a declared namespace prefix, e.g.,
content-type="namespace-prefix:svg". If the namespace prefix is null,
the content-type refers to the default namespace.'

The examples given are unquoted and yet are not NCNames.


Your clarifications on these matters will be most welcome.

Peter West
-- 
Peter B. West  pbwest@powerup.com.au  http://powerup.com.au/~pbwest
"Lord, to whom shall we go?"


-- 
Peter B. West  pbwest@powerup.com.au  http://powerup.com.au/~pbwest
"Lord, to whom shall we go?"


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