Re: procedural variables

[jls@yoda.Rational.COM (Jim Showalter)]

>>Could anybody explain what the rationale for not including procedural
>>variables in Ada is (I have heard it has been discussed and dismissed again
>>in the past few years) ?

They were deemed unsafe, because it is possible to get all fouled up
with lifetime issues. Consider this example:

    procedure outer (...) is

        type some_procedure_type is ...

        foo : some_procedure_type;

        procedure middle (...) is
        
            procedure short_lifetime (...) is -- MATCHES some_procedure_type
            begin
                ...
            end short_lifetime;

        begin
            foo := short_lifetime;
        end middle;

    begin
        middle (...);
        foo; -- WHAT SHOULD HAPPEN HERE?
    end outer;

Anyway, 9x looks like it will have these puppies. How they get around
problems like the above I don't know--I suggest raising program_error
whenever it occurs.
--
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