[wg11] Extending enumeration datatypes and implicit interfacing

[Phil Spiby]

Andy,

You have a point here which needs fixing!
Enumeration items follow the visibility rules, in particular rule (f) under
10.2. Which talks about the enumeration in which they were declared. This
needs amendment to cover the extensible enumeration case like your example
e1 is not visible in s3 (because it is implicitly interfaced) however i1 is
a valid value in e1, e2 and e3 and therefore should be visible in s3.

Based on this we may also need to add a note to 12.7.2 prefixed identifiers
to clarify that in s3 we can refer to e2.i1 and e3.i1.

Phil 

-----Original Message-----
From: wg11-bounces at steptools.com [mailto:wg11-bounces at steptools.com] On
Behalf Of Andy Carpenter
Sent: 10 August 2005 10:19
To: 'WG11'
Subject: Re: [wg11] Extending enumeration datatypes and implicit interfacing


Phil,

    Having looked at example 3 in Clause 8.4.1, the rule that the based-on
datatype of enumeration datatypes is implicitly interfaced is what I would
expect.

    What I'm not sure about is what happens to the enumeration items of
implicitly interfaced enumerations. In the example below from the viewpoint
of s3, e1 is implicitly interfaced. In this case is the item i1 available in
the viewpoint? i.e. is the v1 local variable declaration valid?

    Andy.

schema s1;
type e1 = enumeration of (i1);
end_type;
end_schema;

schema s2;
reference from s1 (e1);
type e2 = enumeration based_on e1 with (i2);
end_type;
end_schema;

schema s3;
reference from s2(e2);
type e3 = enumeration based_on e2 with (i3);
end_type;
procedure p1;
  local
    v1 : e3 := i1;
    v2 : e3 := i2;
    v3 : e3 := i3;
  end_local;
end_procedure;
end_schema;

----- Original Message ----- 
From: "Phil Spiby" <Phil.Spiby at Eurostep.com>
To: "'Andy Carpenter'" <Andy.Carpenter at manchester.ac.uk>; "'WG11'"
<wg11 at steptools.com>
Sent: 09 August 2005 16:34
Subject: RE: [wg11] Extending enumeration datatypes and implicit interfacing


> Andy,
>
> Based_on for select and enumeration should be implicitly interfaced. 
> If it doesn't say so under clause 11 then there is a problem there 
> which should
be
> fixed.
>
> Phil
>
> -----Original Message-----
> From: wg11-bounces at steptools.com [mailto:wg11-bounces at steptools.com] 
> On Behalf Of Andy Carpenter
> Sent: 09 August 2005 14:42
> To: WG11
> Subject: [wg11] Extending enumeration datatypes and implicit 
> interfacing
>
>
> Does the based-on datatype of an enumeration get implicitly interfaced
when
> the enumeration datatype which references it gets interfaced? Clause 
> 11 of the standard makes no statement that it does, which implies that 
> no
implicit
> interfacing happens.
>
> The based-on type for select datatypes is implicitly interfaced. This 
> produces an inconsistency between the two uses of based-on, which 
> seems surprising.
>
>     thanks
>         Andy.
>
> -- 
> ----------------------------------------------------------------------
> -
--
> Dr Andy Carpenter
> School of Computer Science,
> University of Manchester, Manchester M13 9PL, UK
> Email: Andy.Carpenter at manchester.ac.uk
> Tel: +44 161 275 6168
> Fax: +44 161 275 6280
>
> _______________________________________________
> wg11 mailing list
> wg11 at steptools.com http://lists.steptools.com/mailman/listinfo/wg11
>

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