Re: The Dreaded "Missing Subunits"

[Robert A Duff <bobduff@shell01.TheWorld.com>]

Preben Randhol <randhol+news@pvv.org> writes:

> I didn't say you did if you see above. I am wondering what makes it
> different to with a package before the body of another package versus
> before the spec of another package.

If you say:

    with Pack_1;
    package Mumble is
        ...
    end Mumble;

    with Pack_2;
    package body Mumble is
        ...
    end Mumble;

then the name "Pack_1" is visible in both the spec and the body of
Mumble.  The name "Pack_2" is visible in the body of Mumble
(but not in the spec of Mumble).

It doesn't matter whether the above text is stored in one source file or
two.  (Some compilers don't *allow* it to be stored in one source file,
without jumping through hoops (e.g., gnatchop), but that's not a
language issue.)

Another point is that the spec of Pack_1 cannot say "with Mumble;"
because that would introduce a circularity, which is (annoyingly)
illegal in Ada.  The body of Pack_1 could say "with Mumble;",
as could the spec or body of Pack_2.  Again, this has nothing to do with
source files.

Does this answer your question?

Also, look at the syntax rules for "compilation" and "compilation_unit".

- Bob