From: Simon Wright <simon@pushface.org>
Subject: Re: type conversion
Date: Mon, 13 Oct 2014 08:26:48 +0100
Date: 2014-10-13T08:26:48+01:00 [thread overview]
Message-ID: <ly61fozayv.fsf@pushface.org> (raw)
In-Reply-To: m1f1gi$ooh$1@dont-email.me
Georg Bauhaus <bauhaus@futureapps.invalid> writes:
> On 12.10.14 11:37, Pascal Obry wrote:
>> To control the message or the exception to be raised one can use the
>> Predicate_Failure aspect:
>>
>> subtype Integer_String is new String
>> with Dynamic_Predicate => Integer'Value (Integer_String) in Integer,
>> Predicate_Failure => "not an integer string";
>
> Is Predicate_Failure a new aspect in GNAT? My RM does not list it,
> and GNAT GPL 2014 rejects it. GNAT does, however, accept
>
> subtype Integer_String is String
> with Dynamic_Predicate => Integer'Value (Integer_String) in Integer
> or else raise Assertion_Error with "not an integer string";
>
> (And warns that one should use 'Valid instead of a membership test,
> even though there is no object to which one could apply 'Valid.)
Unfortunately using 'Valid would make no difference, because if
Integer_String is say "foo" you get
Exception name: CONSTRAINT_ERROR
Message: bad input for 'Value: "foo"
next prev parent reply other threads:[~2014-10-13 7:26 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-11 23:56 type conversion compguy45
2014-10-12 0:07 ` compguy45
2014-10-12 0:25 ` compguy45
2014-10-12 0:33 ` Jeffrey Carter
2014-10-12 0:38 ` compguy45
2014-10-12 3:45 ` Jeffrey Carter
2014-10-12 2:32 ` Shark8
2014-10-12 4:53 ` Anh Vo
2014-10-12 4:57 ` Shark8
2014-10-12 5:41 ` Anh Vo
2014-10-12 6:38 ` Jeffrey Carter
2014-10-12 9:37 ` Pascal Obry
2014-10-12 11:54 ` compguy45
2014-10-12 23:05 ` Georg Bauhaus
2014-10-13 5:40 ` Pascal Obry
2014-10-13 7:26 ` Simon Wright [this message]
2014-10-13 22:36 ` Randy Brukardt
2014-10-12 9:16 ` Simon Wright
2014-10-12 21:05 ` Shark8
2014-10-12 9:31 ` Simon Wright
-- strict thread matches above, loose matches on Subject: below --
1998-11-01 0:00 Type Conversion Heather Wright
1998-11-01 0:00 ` Tucker Taft
1998-11-01 0:00 ` dewarr
1998-11-02 0:00 ` Michael Kaufman
1998-11-03 0:00 ` Arun Mangalam
1998-11-06 0:00 ` Niklas Holsti
1998-11-02 0:00 ` Marin David Condic
1997-12-08 0:00 Nick Davies
1997-12-08 0:00 ` John English
1997-12-09 0:00 ` Stephen Leake
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