Re: [wsbpel] local variables overriding enclosing scope

[Danny van der Rijn <dannyv@tibco.com>]

I've submitted it as a new issue.

----- Original Message ----- 
From: "Yaron Y. Goland" <ygoland@bea.com>
To: "Yuzo Fujishima" <fujishima@bc.jp.nec.com>
Cc: "Ugo Corda" <UCorda@SeeBeyond.com>; "Danny van der Rijn"
<dannyv@tibco.com>; <wsbpel@lists.oasis-open.org>
Sent: Thursday, March 04, 2004 1:17 PM
Subject: Re: [wsbpel] local variables overriding enclosing scope


> Yeah, this one has really confused me too. I don't understand why it is
> necessary. There doesn't appear to be any possibility of ambiguity and
> the behavior does appear inconsistent with scoping behavior in other
> languages. Why don't we just remove this sentence?
>
> Thanks,
>
> Yaron
>
> Yuzo Fujishima wrote:
>
> > I think an inner-scope variable must override any outer-scope
> > variables of the same name regardless of their type.
> > I believe most, if not all, developers expect that semantics
> > because I don't know any scope-aware languages that don't
> > use the semantics.
> >
> > Yuzo Fujishima
> > NEC Corporation
> >
> > ----- Original Message -----
> > From: "Ugo Corda" <UCorda@SeeBeyond.com>
> > To: "Danny van der Rijn" <dannyv@tibco.com>;
<wsbpel@lists.oasis-open.org>
> > Sent: Thursday, March 04, 2004 9:23 AM
> > Subject: RE: [wsbpel] local variables overriding enclosing scope
> >
> >
> > I was just trying to expose the naming and visibility rules that seem to
> > be behind the 9.2 statement.
> >
> > But you seem to be arguing with those rules, more than with the
> > statement itself. Well, I guess we are defining the language and we are
> > free to define our naming and visibility rules the way we want, as long
> > as they are reasonable and helpful when using the language. In
> > particular, it is up to us to determine what type of declaration can
> > hide others. Evidently the criteria for hiding must be related to how
> > much we consider the declarations to be "the same". Variable name is
> > clearly a way to define their sameness, but type could be an additional
> > criterion.
> >
> > I personally don't have any strong feeling one way or another. Maybe the
> > original author can provide some use cases to illustrate the merits of
> > their choice.
> >
> > Ugo
> >
> >  > -----Original Message-----
> >  > From: Danny van der Rijn [mailto:dannyv@tibco.com]
> >  > Sent: Wednesday, March 03, 2004 4:10 PM
> >  > To: wsbpel@lists.oasis-open.org
> >  > Subject: Re: [wsbpel] local variables overriding enclosing scope
> >  >
> >  >
> >  > this appears to be a circular argument.
> >  >
> >  > "It is not permitted to have variables with same name but
> >  > different messageType/type/element within an enclosing scope
> >  > hierarchy..." "...because an innermost declaration cannot
> >  > hide outer declarations having different messageType/type/element"
> >  >
> >  > the inner variable name unambiguously hides the outer one.
> >  > why should its messageType/type/element matter?
> >  >
> >  > ----- Original Message -----
> >  > From: "Ugo Corda" <UCorda@SeeBeyond.com>
> >  > To: "Danny van der Rijn" <dannyv@tibco.com>;
> >  > <wsbpel@lists.oasis-open.org>
> >  > Sent: Wednesday, March 03, 2004 4:02 PM
> >  > Subject: RE: [wsbpel] local variables overriding enclosing scope
> >  >
> >  >
> >  > I would imagine that the rationale is the following:
> >  >
> >  > - in the case a variable is referenced in a scope, when
> >  > multiple declarations of the same variable with same
> >  > messageType/type/element exist in the enclosing scope
> >  > hierarchy, the reference is unambiguous because the innermost
> >  > declaration hides any outer declarations (it's as if there
> >  > was only one declaration and all the others were hidden).
> >  >
> >  > - in the case a variable is referenced in a scope, when
> >  > multiple declarations of the same variable with different
> >  > messageType/type/element exist in the enclosing scope
> >  > hierarchy, the reference is ambiguous because an innermost
> >  > declaration cannot hide outer declarations having different
> >  > messageType/type/element, and it is then unclear which
> >  > declaration the variable reference is referring to.
> >  >
> >  > Ugo
> >  >
> >  >
> >  > > -----Original Message-----
> >  > > From: Danny van der Rijn [mailto:dannyv@tibco.com]
> >  > > Sent: Wednesday, March 03, 2004 3:31 PM
> >  > > To: wsbpel@lists.oasis-open.org
> >  > > Subject: [wsbpel] local variables overriding enclosing scope
> >  > >
> >  > >
> >  > > in 9.2, it says: "It is not permitted to have variables
> >  > with same name
> >  > > but different messageType/type/element within an enclosing scope
> >  > > hierarchy."
> >  > >
> >  > > can someone explain to me why it is necessary to have this
> >  > > restriction?
> >  > >
> >  > >
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