Re: Environment variables

[Stephen Leake <Stephen.Leake@gsfc.nasa.gov>]

Bob Duff wrote:
> 
> "Robert, you have a strange definition of "extension".  I would say: This
> *is* an extension to the language.  Any Ada compiler can provide
> extensions of this nature (additional useful packages).  Other
> extensions that are explicitly allowed by the RM are additional pragmas
> and attributes.  Most extensions are of course DISallowed by the RM.
> 
> [snip]
> 
Robert Dewar wrote:

> This is just a matter of terminology of course, but by your definition ANY
> package provided with a compiler is an extension (there is nothing special
> about calling a package Ada.xxxx.yyy from this point of view). I do not
> find it useful to use the word extension in conjunction with packages (is
> it an extension of C if you allow C programs to call sockets stuff?)
> 
> [snip]

As the one that started this thread (by asking whether
Ada.Command_Line.Environment was an `extension'), I'd like to say I
agree with Robert Dewar's definition of `extension'; I was being sloppy.
On the other hand, I think it would be reasonable to say that
Ada.Command_Line.Environment is an extension of the "Ada 95 Predefined
Language Environment", which is defined in Annex A of the RM; obviously,
any package could be described this way, so it's not a very useful
description. 

In any case, as Laurent pointed, out, it IS possible to tell from the
sources that Ada.Command_Line.Environment is NOT defined by the Ada 95
RM, which is what I really wanted to know. However, it requires knowing
what the commenting style is in packages that are defined in the RM. I
think compiler-provided packages that are NOT defined by the RM should
be more clearly labeled as such, to make it easier to know when we are
being non-portable.

-- 
- Stephe