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   RE: [xml-dev] ASN.1 is an XML Schema Language (Fix those lists!) and Bin

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At 19:32 04/11/2003 +0000, you wrote:
> > I remember the SGML and ASN wars over a decade ago but
> > had no personal involvements.  I do remember some smart
> > folks at the time in the SGML camp saying that ASN was
> > a well-conceived technology but overbuilt for the documentation
> > market.  Is is an XML Schema language?  Sure.  And?
> >
> > It seems to me that XML took the market because:
> >
> > 1.  Simpler.
> > 2.  Smelled like HTML.
> > 3.  Had a ready made market from the SGML community.
> > 4.  Smelled like HTML.
> > 5.  Had the W3C to bless it.... eventually.
> > 6.  Had the SGML community's experience with hypermedia
> >     gained during the CALS era.
> > 7.  Smelled like HTML.
> >
> > There may be others.
>   0.  XML parser @ $0.00 vs. ASN.1 parser @ $50,000.00
>The other reasons are completely irrelevant.
>Michael Kay

The interest of the discussion about ASN.1 is to show some lacks of XML 
(binary format, language binding, ...).
I don't think that ASN.1 is the solution.
But remember that ASN.1 is only a part of the triad :
         concret syntax, abstract syntax, transfert syntax

Now consider these 3 "worlds" : ASN.1 (OSI), CORBA (OMG) and XML (W3C).
1) ASN.1
abstract syntax : ASN.1 (ISO 8824-x / ITU-T X.68x)
transfert syntax : BER, DER, PER (ISO 8825-x / ITU-T X.69x)
concret syntax : exists for Java, C++, C or COBOL but not as International 

abstract syntax : IDL (OMG-CORBA / ISO 14750)
transfert syntax : CDR (OMG-CORBA-IIOP)
concret syntax : Mapping for Java, C++, C, Ada, COBOL, Lisp, SmallTalk, 
Python (OMG-CORBA)

3) XML
abstract syntax : DTD (W3C), Schemas (W3C), RELAX NG (OASIS)
transfert syntax : XML (W3C)
concret syntax : ???, some endeavors like JAXB

For historical reasons, the XML world is transfert syntax centric.
Both ASN.1 and CORBA try to take advantage of the XML success, ASN.1 with 
XER (ITU-T X.693) and CORBA with the specification "CORBA to WSDL/SOAP - 
January 2003" that allows the transformation from IDL to W3C Schema.

In XML data-oriented applications, ASN.1 and IDL want to be more than a new 
schema (ie an abstract syntax) for validation. The goal is the generation 
of codec  between a XML stream and some concret languages like JAVA.

I'm more confident in CORBA-IDL for the following reasons :
         - IDL is very easy to learn
         - writing an IDL compiler is easy (the grammar is ready for yacc)
         - a lot of Open Source ORB already exist
         - all of CORBA specifications are freely available (on www.omg.org)
         - IDL defines types and *operations* that could be mapped to SOAP 

Perhaps CORBA-IDL is the new ASN.2 and nobody knows that.

François Perrad.


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