[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: ASN.1 is an XML Schema Language (Fix those lists!) and Bin
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. > >Like > 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 Standards 2) CORBA 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 service Perhaps CORBA-IDL is the new ASN.2 and nobody knows that. François Perrad.
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