Syntax Definition Language used in W3C XML page

[muchan]

A simple question. (Sorry, if it's already in FAQ)

What is the syntax definition language used in the XML 1.0 page of the W3C <http://www.w3.org/TR/REC-xml/>?

I searched some syntax definition lanugages, and found that EBNF (ISO/IEC 14977 : 1966(E)) to be the most standard one, but after reading through the EBNF pecification, I found that W3C page uses '::=' for difining-symbol, where EBNF uses just '='.


Is W3C using basically EBNF syntax, but just ::= as defining-symbol? Or is there some other spec that W3C offcially decided to use? Or is there somewhere a summary what W3C's difinition standard differs from EBNF?

Thanks in advance.

muchan

 

[dr7tbien]

A simple question. (Sorry, if it's already in FAQ)

What is the syntax definition language used in the XML 1.0 page
of the W3C <http://www.w3.org/TR/REC-xml/>?

I searched some syntax definition lanugages, and found that
EBNF (ISO/IEC 14977 : 1966(E)) to be the most standard one,
but after reading through the EBNF pecification, I found that
W3C page uses '::=' for difining-symbol, where EBNF uses just '='.


Is W3C using basically EBNF syntax, but just ::= as defining-symbol?
Or is there some other spec that W3C offcially decided to use?
Or is there somewhere a summary what W3C's difinition standard differs
from EBNF?

Thanks in advance.

muchan

 

[Andy Dingley]

What is the syntax definition language used in the XML 1.0 page of the W3C <http://www.w3.org/TR/REC-xml/>?

BNF (Backus-Naur Format), the original flavour, which dates back to around 1960 and the Algol 60 language spec (the oldest ref I've ever used with it). This is probably the most common variant.

The defining symbol is "::="

If you read
http://www.cl.cam.ac.uk/~mgk25/iso-14977.pdf it might explain some of the reasoning behind the later EBNF, where the defining symbol changed to "=". I forget why, I've rarely seen this syntax used and I've never written it.

 

[muchan]

BNF (Backus-Naur Format), the original flavour, which dates back to around 1960 and the Algol 60 language spec (the oldest ref I've ever used with it). This is probably the most common variant.

The defining symbol is "::="

If you read
http://www.cl.cam.ac.uk/~mgk25/iso-14977.pdf it might explain some of the reasoning behind the later EBNF, where the defining symbol changed to "=". I forget why, I've rarely seen this syntax used and I've never written it.

Thank you very much.

I read the iso-14977.pdf prior to asking question, but didn't know that original BNF used "::=". The document tells about the reason to extend BNF, but doesn't explain muchan about the reason to have changed the symbols.

muchan