Re: Why is it Called a Package?

["Samuel T. Harris" <samuel_t_harris@Raytheon.com>]

Pascal Obry wrote:
> 
> Brian Rogoff <bpr@shell5.ba.best.com> a écrit dans le message :
> Pine.BSF.4.21.0004061305320.6588-100000@shell5.ba.best.com...
> > I think if the syntax were to be redone I'd like the issue of "()" versus
> > "[]" for array indexing to be reexamined. Then we could also think about
> > some syntactic sugar for overloading "[]" as in C++. The restrictions on
> > the character set that were part of the original Ada requirements don't
> > make a lot of sense to me now, though the restriction to ASCII is OK.
> 
> I don't think we want that. A very nice consequence here is that you can
> easily change an abstraction from:
> 
>    package P is
>       Some_Value : array (1 .. 10) of Integer;
>       --  first quick implementation using basic array
>    end P;
> 
> to
> 
>    package P is
>       function Some_Value (N : in Positive) return Integer;
>       --  real implementation using a complex structure
>    end P;
> 
> (or the other way around) without modifying all client code.
> 
> I really don't see what would be gained by using "[]"... a more
> C/C++ syntax :)

I'd rather see [] and {} be allowed as substitutions for ()
in a similar way that ! of allowed for |, % is allowed for ",
and : is allowed for #. Of course, just as %'s substituded for "
have to be paired, so would {} and [] substitutions.

I see no compelling reason why array indexing
must be syntactically different from function calls. I do see
that some Ada code, especially when building complex aggregates,
starts to look like LISP (Lots of Insane Silly Parentheses).
I'd like to be able to use {} and [] for different levels
of (). If one then wants to make a style guide issue out of using
[] for indexing and {} to bracket all aggregates, then fine.

This is a very easy and backward compatible change to the
language definition. I suppose Apex would have a problem since
it uses [] for statement prompts. OTOH there are still many
more characters it can use for statement prompt delimiters.

-- 
Samuel T. Harris, Principal Engineer
Raytheon, Aerospace Engineering Services
"If you can make it, We can fake it!"