From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=0.6 required=5.0 tests=BAYES_00,TO_NO_BRKTS_FROM_MSSP autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,6cc2d0131145e263 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-08-10 06:16:04 PST Path: archiver1.google.com!newsfeed.google.com!newsfeed.stanford.edu!feed.textport.net!newsranger.com!www.newsranger.com!not-for-mail Newsgroups: comp.lang.ada From: Ted Dennison References: <3B72C23E.62F7B3D2@san.rr.com> <871ymk480x.fsf@deneb.enyo.de> Subject: Re: Question about Message-ID: X-Abuse-Info: When contacting newsranger.com regarding abuse please X-Abuse-Info: forward the entire news article including headers or X-Abuse-Info: else we will not be able to process your request X-Complaints-To: abuse@newsranger.com NNTP-Posting-Date: Fri, 10 Aug 2001 09:15:14 EDT Organization: http://www.newsranger.com Date: Fri, 10 Aug 2001 13:15:14 GMT Xref: archiver1.google.com comp.lang.ada:11755 Date: 2001-08-10T13:15:14+00:00 List-Id: In article , Larry Kilgallen says... > >I have not worked with streams, but was wondering if anyone had tried >using ASN.1 to achieve interoperability. It solves endian problems >and the DER representation is rather firm about "only one way to express >something". Is it? For instance, data can be encoded with lengths, or with an "End-of-Contents" octet. The copy I have here is about 16 years old, and I don't have a "DER", just a BER. My memory from when I did it was that there were indeed multiple ways to encode most anything, but again that was many moons ago. I'd think the big problems with ASN.1 streams would be: o ASN.1 is too damn complicated. o The encoding data structures are too flexible to map directly into Ada. o Some ASN.1 types have no direct Ada analog. o Some Ada types have multipe possible ASN.1 analogs. o Since its type-based, you couldn't just do the job with a custom stream. You'd also have to recode every type to output ASN.1 from its stream attributes. The last is a bit of a problem for *any* custom stream in Ada. If you care about the internal data types or things like record boundries, then you end up having to rewrite all the type stream attributes. This is a lot of work. It also prevents people from using just any type with your stream, and it prevents anyone from using those types with any other streams that you may have lying around. --- T.E.D. homepage - http://www.telepath.com/dennison/Ted/TED.html home email - mailto:dennison@telepath.com