Re: "use" clauses and Ada 95 OOP

[jamess1889@aol.com (JamesS1889)]

In article <JSA.96Jul19191630@alexandria>, jsa@alexandria (Jon S Anthony)
writes:

>What do either of you mean by "the function that is associated with X
>at runtime" here?  In the environment we are talking about here there
>is no "_the_ func associated with X".  X contains a value which will
>have a type indicator which will provide access to the proper jump
>table entry.  Since the value of X can change (e.g., in C++ or Java up
>level assignments) the func "associated" with X can change (and not
>necessarily be the one defined in the class of which X was a declared
>instance).  Seems pretty much like the exact same issue.

You are speaking of the value of X, and you are treating func as if it
were a specific function.  I believe Mitch was speaking NOT of the value
of X but of X as an object, and I believe he was speaking of func as "any
function".  At least that is what I took it as.

In C++ and Java, functions that operate on objects are defined
syntactically within the definition of the object, on the same level with
the attributes of the object.  The corollary in Ada (which would be
illegal) would to all function definitions to appear between the "type x
is tagged record..." and the "end record;" - sort of like what Ada95 DOES
do with protected objects.

In C++ and Java, you can write x.func.  In Ada95, you have to write
Pkg2.Func(x), UNLESS you use the "use clause", which is the question this
whole thread is about.

Now, do you understand?

James Squire                                      
mailto:ja_squire@csehp3.mdc.com
MDA Avionics Tools & Processes
McDonnell Douglas Aerospace              http://www.mdc.com
Opinions expressed here are my own and NOT my company's
"Only one Earth Captain has ever survived battle with a Minbari fleet.  He
is behind me.
You are in front of me.  If you value your lives, be somewhere else!"
           -- Delenn, "Severed Dreams"