In converting XML instance A to XML instance B, this property mustbe pre

["Costello, Roger L." <costello@mitre.org>]

Hi Folks,

 

This hex string is the EBCDIC encoding of the uppercase letter A:

 

                C1

 

This hex string is the ASCII encoding of the uppercase letter A:

 

                41

 

Suppose we create a tool that converts EBCDIC text to ASCII text. The main aspect of the conversion is that the input has a property called semantics – its “meaning” – which must be preserved by the process. For example, the conversion must preserve this semantics: “uppercase letter A.”

 

Next, consider this XML which expresses the location of Boston’s Logan airport, using an ICAO code:

 

                <Airport>

                      <ICAO>KBOS</ICAO>

                </Airport>

 

This XML expresses the location of Boston’s Logan airport, using latitude/longitude:

 

                <Airport>

                      <Latitude>42.3631° N</Latitude>

                      <Longitude>71.0064° W</Longitude>

                </Airport>

 

Suppose we create a tool that converts ICAO locations to latitude/longitude locations. The main aspect of the conversion is that the input has a property called semantics – its “meaning” – which must be preserved by the process. For example, the conversion must preserve this semantics: “location of Boston’s Logan airport.”

 

But wait! Haven’t we stated that XML doesn’t have semantics? If XML doesn’t have semantics, how can a conversion process preserve semantics?

 

I’m confused.

 

Question: An XML instance document has semantics:

 

(a)    Yes

(b)   No

 

/Roger