[SCL] Abstract Syntax, ISO 8824/8825

[Tanel Tammet]

Jim Farrugia wrote:

> I just did a search on "abstract syntax" and found out that there is
> an ISO standard dealing with asbtract syntax. The standard is ISO 8824/8825, and
> it deals with ASN.1, with "ASN" short for "Abstract Syntax Notation".
> 
> Some info is available from the non-broken links on
> 
> http://www.usrconsult.be/Reference_Documents/ISO_8824_8825.shtml
> 
> Also, http://www.isi.salford.ac.uk//books/osi/chap8.html gives some
> kind of overview.
> 
> I can't tell if this standard is or will be relevant to some of your efforts.
> A glance at the latter URL should tell you pretty quickly, I would guess.

Thanks!

This confirmed my suspicions that ALL the syntaxes we have
considered so far for SCL are hugely abstract.

The ISO "abstract syntax" is pretty concrete in comparison,
containing (observe: SYNTHETIC!) examples like

       Month ::= INTEGER (1..12)
       Day ::= INTEGER (1..31)
       Daily-temperatures ::= SEQUENCE SIZE (31) OF INTEGER
       Name ::= PrintableString (SIZE (1..20 ))


       SEQUENCE
           {first-field INTEGER (0..7),
            second-field BOOLEAN,
            third-field  INTEGER (0..3)
            fourth-field SEQUENCE
                          {fourA  BOOLEAN,
                          fourB  BOOLEAN} }


Regards,
         Tanel