implementing from 1003.2

[Arnold Robbins]

Submitted-by: arnold%audiofax.com at mathcs.emory.edu (Arnold Robbins)

In article <132258 at uunet.UU.NET> andrew at alice.att.com (Andrew Hume) writes:
>	Can someone help clear up my misconceptions?
>I recently read someone complain about difficulties implementing
>bc from the spec in 1003.2 and some quick reponse from the author
>of that spec. What puzzled me is the underlying assumption that
>you are supposed to be able to implement from the 1003.2 description.
>Is this supposed to be true? (it obviously isn't for make, for example.)
>I thought 1003.2 simply described stuff so you can use it, not implement it.

I'm not sure what the "official" goal of the standard is wrt being able
to implement from it, but at least unofficially, this is something the
working  and balloting groups are aiming at.  Lot of peoples, notably UCB
and GNU, are using the standard as their spec for their implementations.

If one wishes to create a system that is both posix conforming and
at&t-source-code-free, then a spec that can be implemented from is a
necessity.

Of course, one could also argue that if the spec is good enough to implement
from, then it is certainly good enough to describe how to use the utility.
In some cases, like bc, awk, yacc, and lex, the spec for use is complicated
enough anyway that it becomes a spec good enough for implementing by.
(How do I know that	awk 'BEGIN { print "hi" } ; END { print "bye" }'
is legal while		awk 'BEGIN { print "hi" }   END { print "bye" }'
isn't?  Presenting a grammar for the language is almost a necessity...)
-- 
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2000 Powers Ferry Road, Suite 200 / Marietta, GA. 30067 | lack of an idea.
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Volume-Number: Volume 23, Number 63