From: Jacob Sparre Andersen <jacob@jacob-sparre.dk>
Subject: Re: Making sense of predicates
Date: Tue, 22 Oct 2013 09:35:02 +0200
Date: 2013-10-22T09:35:02+02:00 [thread overview]
Message-ID: <87eh7drc61.fsf@adaheads.sparre-andersen.dk> (raw)
In-Reply-To: 1830ad81-00dc-4639-922a-771a01cd06ec@googlegroups.com
Shark8 <onewingedshark@gmail.com> writes:
> Agreed; I was disappointed the following doesn't work:
>
> Subtype Digit_Character is Character range '0'..'9';
>
> Subtype Part_Number is String
> with Static_Predicate => (for all C in Part_Number => C in Digit_Character);
>
> As it would be nice to basically subtype out [further-constrain] the
> element-type just as we can do to the index (e.g. "Subtype
> Phone_Digits is String(1..7);", which is equivalent to "subtype
> phone_range is Positive range 1..7; Subtype Phone_Digits is
> String(Phone_Range);", where 'phone_range' is an anonymous subtype.)
If you did it right, it would work:
package Parts is
subtype Digit_Character is Character range '0' .. '9';
subtype Part_Number is String
with Dynamic_Predicate => (for all C of Part_Number
=> C in Digit_Character);
end Parts;
with Parts;
procedure Use_Parts is
Work : Parts.Part_Number := "1234";
Fail : Parts.Part_Number := "fail";
begin
null;
end Use_Parts;
% ./use_parts
raised SYSTEM.ASSERTIONS.ASSERT_FAILURE : Dynamic_Predicate failed at use_parts.adb:6
%
Greetings,
Jacob
--
Photos from the Faroe Islands:
http://billeder.sparre-andersen.dk/The_Faroe_Islands/
next prev parent reply other threads:[~2013-10-22 7:35 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-21 19:51 Making sense of predicates Dmitry A. Kazakov
2013-10-22 4:35 ` Randy Brukardt
2013-10-22 8:19 ` Dmitry A. Kazakov
2013-10-22 12:53 ` Georg Bauhaus
2013-10-22 13:38 ` Dmitry A. Kazakov
2013-10-22 20:38 ` Georg Bauhaus
2013-10-24 4:03 ` Randy Brukardt
2013-10-24 7:26 ` Dmitry A. Kazakov
2013-10-22 7:14 ` Shark8
2013-10-22 7:35 ` Jacob Sparre Andersen [this message]
2013-10-22 17:26 ` Shark8
2013-10-23 7:56 ` Jacob Sparre Andersen
2013-10-24 3:58 ` Randy Brukardt
2013-10-22 8:11 ` Dmitry A. Kazakov
2013-10-22 7:20 ` Jacob Sparre Andersen
2013-10-22 7:57 ` Dmitry A. Kazakov
2013-10-22 14:52 ` Dan'l Miller
2013-10-22 16:30 ` Dmitry A. Kazakov
2013-10-22 17:15 ` Dan'l Miller
2013-10-22 19:26 ` Dmitry A. Kazakov
2013-10-22 19:49 ` J-P. Rosen
2013-10-22 21:30 ` Dan'l Miller
2013-10-23 9:25 ` Dmitry A. Kazakov
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