Re: Ada.Execution_Time

[Keith Thompson <kst-u@mib.org>]

"Randy Brukardt" <randy@rrsoftware.com> writes:
> "Adam Beneschan" <adam@irvine.com> wrote in message 
> news:dfcf048b-bb6e-4993-b62a-9147bad3a6ff@j32g2000prh.googlegroups.com...
> On Dec 15, 2:52 pm, Keith Thompson <ks...@mib.org> wrote:
> ...
>>> So, um, why is Assert a pragma rather than a statement?
>>>
>>> if Debug_Mode then
>>> assert Is_Good(X);
>>> end if;
> ...
>>Somebody on the ARG might have a more authoritative answer.  My
>>reading of AI95-286 is that a number of Ada compilers had already
>>implemented the Assert pragma and there was a lot of code using it.
>>Of course, those compilers couldn't have added "assert" as a statement
>>on their own, but adding an implementation-defined pragma is OK.
>
> That's one reason. The other is that you can't put a statement into a 
> declarative part (well, you can, but you need to use a helper generic and a 
> helper procedure, along with an instantiation, which is insane -- although 
> it is not that unusual to see that done in a program). A lot of asserts fit 
> most naturally into the declarative part (precondition ones, for instance, 
> although those will be better defined separately in Ada 2012).

So add an assert operator that always yields True:

    declare
        Dummy: constant Boolean := assert some_expression; -- assert operator
    begin
        assert some_other_expression; -- assert statement
    end;

Though the use of "Assert" as an identifier in existing code is
certainly an issue.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Nokia
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"