Re: Philosophy of XML datatypes (was: What is an integer? (was: Re: [xml-dev] XML Quiz))

Previously Roger wrote:

The value of the <num> element -- 44 -- represents an integer.

Peter Flynn responded:

No, the *value* of the <num> element *is* an integer. It's the '44' that *represents* an integer.

Ghislain Fourny followed up with:

Formally, in XML Schema, this is captured by types having a value space and a lexical space.

The value space of xs:integer is the set of the actual mathematical integers, so Z.

The lexical space of xs:integer is the set of strings corresponding to the decimal representation of an integer.  Roger: The set of strings matching this regex: [+-]?[0-9]+ 

The lexical mapping of xs:integer maps each string representation (also called a literal, this is what appears in XML as text) to an integer value in the value space.

Fantastic! Thank you!