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Date: Tue, 10 Aug 2010 10:21:32 +0200
From: Georg Bauhaus <rm-host.bauhaus@maps.futureapps.de>
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Subject: Re: S-expression I/O in Ada
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Date: 2010-08-10T10:21:33+02:00
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On 8/9/10 9:18 PM, Robert A Duff wrote:

>> case {T0 x T1 x T3} is
>>   when ... =>  ...

>> Experimenting further, what will be a useful type of
>> case_statement_alternative's discrete choice list, then?
>> One that can be explored programmatically?
>
> Any non-limited type, I guess.

I was fancying effects that programmers might want to inject into
the switching machinery of the case statement?  In the sense of
what I think they are calling aspect oriented programming.

   type C is  ...  record ... end record;
   type D is new C and Aspects with null record;  -- for case
     -- or use aspect notation for D?

   x : D := (C with null record);

   case x is
    when D'(comp_1, ..., comp_n) => ...


Generalizing, could we have aspects of types permitting the
specification of effects to be triggered, for example when
a primitive op is called?  (Much like SNOBOL-4's TRACE feature
works.)


Georg