[xsl] Use of fictitious types in the F & O spec considered unsatisfactory

[Dimitre Novatchev <dnovatchev@xxxxxxxxx>]

The use of the so called "numeric" type in defining the op:numericXXX
operators in the Functions and Opertors spec results in unwanted
confusion and complexity of the document.

Firstly, it uses an undefined type.

Secondly, this results in a special rule that some "system" functions
and operators *only* can have overloads with the same number of
arguments.

The solution is obvious: define the type "numeric" and support it as a
builtin type. This is not unprecedented, as we already have such types
as xdt:anyAtomicType and xdt:untypedAtomic

I propose that there should be an xdt:numeric defined builtin type in
Xpath 2.0. This may also unify and make more simple or intuitive the
rules for conversion between different numeric types.


Cheers,

Dimitre Novatchev.