Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!lamaster
From: lamaster@ames.arc.nasa.gov (Hugh LaMaster)
Newsgroups: comp.arch
Subject: Re: Endian wars
Message-ID: <21666@ames.arc.nasa.gov>
Date: 10 Feb 89 21:01:11 GMT
References: <6133@columbia.edu> <186@aucsv.UUCP> <21557@ames.arc.nasa.gov> <9468@cit-vax.Caltech.Edu> <21609@ames.arc.nasa.gov> <8475@louie.udel.EDU>
Organization: NASA - Ames Research Center
Lines: 33

In article <8475@louie.udel.EDU> new@udel.EDU (Darren New) writes:

>If you are really looking for a COMMON interchange format, ASN.1 is the way to
>go. XDR is nice when you are working with C, but defining something like a font

>etc as big as you want. Unfortunately, it does not at this time have a single,
>standard floating-point format, but this is easy to add on an application

But floating point IS my problem.  Yes, it IS easy to add on an application
basis, just not on a hundreds-of-applications basis.  (Text data is easy to
convert on an application basis also between character sets of different types.
But when you want to create text files that can be read by a large number of
applications you are going to write in the future, you use ASCII.  In the
future, perhaps you will be able to use ASN.1 data streams.)  It also
can be expensive, even though it is "easy", when you need to translate large
quantities of data between different data types.  (End of sermon :-) )

Anyway, does ASN.1 define some kind of file structure?  (Since this is USENET,
we won't use the R-word (a logical r*c*rd for you old-timers over thirty)).  
Are the data types defined in the structure somewhere, so that a conversion 
program can figure out what it is converting from/to?  Is there a well
defined library with C and Fortran bindings that an applications programmer
can use to read and write ASN.1 files with?  Will the cost of using ASN.1
structured data approach zero as the structures become large (arrays of 10000
floating point numbers, for example)?  If the answer is yes to all these
questions, I would like to know more.


-- 
  Hugh LaMaster, m/s 233-9,  UUCP ames!lamaster
  NASA Ames Research Center  ARPA lamaster@ames.arc.nasa.gov
  Moffett Field, CA 94035     
  Phone:  (415)694-6117