> I don't care a fig what any standard says, it's foolish.

+1

  - Andreas

> -----Original Message-----
> From: squeak-dev-bounces at lists.squeakfoundation.org 
> [mailto:squeak-dev-bounces at lists.squeakfoundation.org] On 
> Behalf Of Tim Rowledge
> Sent: Sunday, October 12, 2003 11:03 PM
> To: squeak-dev at lists.squeakfoundation.org
> Subject: Re: [FIX] ClassVarsFix-petervr (was: 
> Sharedvariablesbinding/lookupbug)
> 
> 
> "Peter van Rooijen" <squeak at vanrooijen.com> wrote:
> 
> > What exactly do you mean by "it", which you consider so dangerous?
> > 
> > Is it the fact that class variables shadow pool variables 
> shadow global
> > variables (i.e., part of the Smalltalk shared variable scope rules)?
> Yes. I think it's a really stupid thing to do. It doesn't matter if it
> is technically within any 'standard rules'. It's just plain dumb t do
> it.
> 
> > > Worse yet it makes a
> > > possibility that two bits of code that look very similar 
> can refer to
> > > quite different variables.
> > 
> > That is indeed how Smalltalk works, yes.
> You don't need to lecture me on how Smalltalk works. I've been making
> it professionally for twenty years.
> 
> > 
> > > Even worse, the time-order of compiling
> > > methods could result in some refering to the global and 
> some to the
> > > classvariable.
> > 
> > No, it can't, unless there are bugs in the implementation 
> (which currently
> > probably do exist because it seems that this has not been 
> given attention
> > before). The scope rules are unambiguous. So, what you are 
> saying is not a
> > complaint against the scope rules.
> 
> Compile a method referring to a Foo global.
> Add a class variable Foo to the same class. (Squeak objects 
> to this, I'm
> happy to see.)
> Compile another method referring to 'Foo'.
> 
> What do you expect to be the result?
> 
> > 
> > > All in all, a terribly bad thing.
> > 
> > In your view, is it so terribly bad that you would also 
> want to prohibit
> > people from defining globals with the same name as an existing class
> > variable or pool variable?
> Until and unless there is a clearly visible way to differentiate them,
> yes I would like to prevent it.
> 
> Consider another situation:-
> Class A has a method referring to Foo, a global.
> Class B, a subclass of A, adds a class variable Foo.
> A method in B refers to Foo, which clearly you claim binds to 
> the class
> variable. It also sends a message which resolves to the method in A
> which refers to Foo the global.
> 
> Now try to make any internal sense of this when you have to debug or
> refactor this code. Yes, I'm sure that a compiler can be made to cope
> with it but our brains are not compilers (and I don't care what the
> Forth guys claim) and I feel pretty sure such code would present a
> major cognitive clash.
> 
> I don't care a fig what any standard says, it's foolish.
> 
> tim
> --
> Tim Rowledge, tim at sumeru.stanford.edu, http://sumeru.stanford.edu/tim
> Disc space, the final frontier!
>