[Oberon] Type guard: unnecessary?

[Srinivas Nayak]

Many thanks Jorg,

I never thought SYSTEM.VAL can do the job.



With thanks and best regards,

Yours sincerely,
Srinivas Nayak

Home: http://www.mathmeth.com/sn/
Blog: http://srinivas-nayak.blogspot.in/

On 10/08/2016 03:31 PM, Jörg Straube wrote:
> Hi Srinivas
>
> Strictly speaking it is not necessary, as this statement with type guard
>    r := p(Circle).radius;
>
> could be te-written as
>    IF p IS Circle THEN
>       c := SYSTEM.VAL(Circle, p);
>       r := c.radius
>    END;
>
> Jörg
>
>> Am 08.10.2016 um 11:01 schrieb Srinivas Nayak <sinu.nayak2001 at gmail.com>:
>>
>> Any help please?
>>
>>
>> With thanks and best regards,
>>
>> Yours sincerely,
>> Srinivas Nayak
>>
>> Home: http://www.mathmeth.com/sn/
>> Blog: http://srinivas-nayak.blogspot.in/
>>
>>> On 09/29/2016 06:58 PM, Srinivas Nayak wrote:
>>> Dear All,
>>>
>>> In the Programming in Oberon (Tutorial) rev. 5.10.2015, in section 23.2 last paragraph we read:
>>> "The simple designator p.radius would not be acceptable, because p is of type Figure."
>>> In section 23.4 last but one paragraph we read:
>>> "The further facility of the type guard is merely one of convenience."
>>>
>>> Is type guard not necessary?
>>>
>>>
>>> With thanks and best regards,
>>>
>>> Yours sincerely,
>>> Srinivas Nayak
>>>
>>> Home: http://www.mathmeth.com/sn/
>>> Blog: http://srinivas-nayak.blogspot.in/
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