Re: [sv-ec] Re: Type parameters, typedefs, and general BNF semantics

Mark Hartoog wrote:
>
> There already is a BNF rule, type_identifier, that specifies where
> type parameters and typedefs can be used.
>
Hello all,

Aren't we straying pretty far from reality here? The BNF describes the 
grammar in terms of what lexical tokens constitute valid sentences in 
SystemVerilog's syntax. As such, both *class_identifier* and 
*type_identifier* derive the same rule (not surprisingly, named simply 
*identifier*) in section A.9.3. Syntactially, *class_identifier* and 
*type_identifier* are interchangeable.

The distinctions being discussed here are semantic in nature and derive 
from the normative text, not the BNF. It seems to me that either 
interpretation is /syntactically /legal, according to the BNF. The 
discussion should be what interpretation is /semantically /legal, and if 
ambiguous or inconsistent, what's the appropriate remedy.

-randy.

Mark Hartoog wrote:
>
> I think this kind of catch all language in the LRM is a very bad idea.
> There already is a BNF rule, type_identifier, that specifies where
> type parameters and typedefs can be used. If there are places where it
> needs to be added, then we should consider those proposals. This
> proposal
> is so vague that no one can understand what they might be enabling by
> approving this. You want to allow typedefs and type parameters anywhere
> "unless otherwise restricted". What exactly does that phase mean.
>
> Consider a class declaration:
>
> class_declaration ::= // from A.1.2
>        [ virtual ] class [ lifetime ] class_identifier [
> parameter_port_list ]
>        [ extends class_type [ ( list_of_arguments ) ] ];
>        { class_item }
> endclass [ : class_identifier]
>
> Surely you are not suggesting that the declaration name of the class can
> be a typedef or type parameter. Where is the restriction for this? Is it
> just
> that it makes no sense?
>
> I think this change would only further confuse the issue.
>
> > -----Original Message-----
> > From: owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org] On
> > Behalf Of Gordon Vreugdenhil
> > Sent: Monday, October 08, 2007 3:13 PM
> > To: SV_EC List; Mehdi Mohtashemi
> > Subject: [sv-ec] Re: Type parameters, typedefs, and general
> > BNF semantics
> >
> >
> >
> > Gordon Vreugdenhil wrote:
> > [...]
> > > I'll follow-up to this a bit later today with a Mantis item and
> > > proposal to address what I think is the more consistent and correct
> > > way in which to read the intent of the LRM in this area.
> >
> >
> > I have filed Mantis 2087 on this issue and attached a proposal.
> >
> > Mehdi, given the potential for substantial impact on the
> > overall LRM if this proposal does not express the intent of
> > the committee, could we address this at the next EC meeting?
> >
> > Gord.
> > --
> > --------------------------------------------------------------------
> > Gordon Vreugdenhil                                503-685-0808
> > Model Technology (Mentor Graphics)                gordonv@model.com
> >
> >
> > --
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