Re: Question about name resolution

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

"Michael B." <michaelb@example.com> writes:

> The following example does not compile because the call to "P" is ambiguous:
>
> procedure Main is
>
>    procedure P is
>    begin
>       null;
>    end P;
>
>    procedure P (I : Integer := 0) is
>    begin
>       null;
>    end P;
>
> begin
>    P;
> end Main;
>
> What syntax is needed to call the first "P" without parameters?

The correct syntax is as follows:

procedure Main is

   procedure Some_Other_Name is
   begin
      null;
   end Some_Other_Name;

   procedure P (I : Integer := 0) is
   begin
      null;
   end P;

begin
   P;
end Main;

There are three ways to resolve overloading ambiguities:

    1. Change the names (use less overloading).
    2. Use qualified expressions (e.g. String'(F(X))).
    3. Use expanded names (e.g. Package_Name.Procedure_Name).

Only 1 works here.

If the things are declared in third-party libraries that you can't
change (or don't want to), then only 2 and 3 work.  Otherwise, if you're
getting a lot of ambiguities, 1 is often (usually?) the right way.

- Bob