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Macros were withdrawn in around 1990! They were without doubt a step in the
wrong direction!
John L
Robin Berjon wrote:
> tpassin@c... wrote:
>
>> According to some things I have read or been told, ASN.1 was
>> originally developed for people - people communication, to let them
>> explain schemas to each other. Probably because of that, it turned
>> out to be a bear to parse. I do not know if the residue of this
>> still plays a role, but full ASN.1 has an awful lot of syntax
>> features.
>
>
> Yes, ASN.1 became quite hard to parse at some point, notably when they
> added macros that could be used before they were defined and had no
> termination marker -- it was impossible to get right. But I was led to
> believe that some of the later edits to the specs tried to make things a
> bit easier.
>
>> Maybe it is like XML Schema - no one has yet implemented every
>> feature correctly (or have they by now?).
>
>
> Well that's a cause for concern, if no one has implemented XML Schema
> correctly, and no open source implementation of ASN.1 exists, then X.694
> which bridges both worlds will be unavailable to those of us who can't
> shell out the cash :/
>
>> I think that some of the sophisticated encodings like PER are very
>> hard to get right and complete, too (I have never looked into these
>> encodings, so have no first-hand experience here).
>
>
> I don't think PER qualifies as "very hard", but yes it certainly
> qualifies as much harder than BER.
>
--
Prof John Larmouth
Larmouth T&PDS Ltd
(Training and Protocol Development Services Ltd)
1 Blueberry Road
Bowdon j.larmouth@s...
Cheshire WA14 3LS
England
Tel: +44 161 928 1605 Fax: +44 161 928 8069
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