Re: Elaboration order handling (Was: Bug in 'gnatmake')

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

Jeffrey Carter <spam.jrcarter.not@spam.not.acm.org> writes:

> (By "statement", I mean something with a terminator semicolon that I
> count as a statement when counting statements, which includes
> declarations. By "null statement" I mean a statement identical to Ada's
> null statement, even if it's a declaration. So, yes, the language could
> require a null statement in a declarative part.)

Interesting.  You are very close to agreeing with me that statements and
declarations are more-or-less the same thing (syntactically), and
wherever one is allowed, so should the other.  What's wrong with
statements in a package spec (or body decl part)?  If you allow "null;"
in a declarative part, then why not allow an assignment statement, or a
procedure call?  And if you do that, there's no point at all to the
"begin" that appears in the middle of a procedure body.

Once in a while, I want to initialize an object using statements,
because the "X: T := ...;" syntax doesn't work for some reason.

    package body P is
        X : ...;

        package Dummy is end;
        package body Dummy is
        begin
            for I in ... loop
                X(I) := ...;
            end loop;
        end Dummy;
        ... -- 1000 more lines of code

That extra Dummy package doesn't aid readability.  The other choice,
moving the initialization way down into the "begin...end P;" part
is also bad, because the initialization is far away from the
declaration, and there's lots of opportunity to use uninitialized
variables in between.

- Bob