Re: Me no understand scoping

["Neil Jerram" <neiljerram@googlemail.com>]

2008/8/2 Maciek Godek <pstrychuj@gmail.com>:
>> 1. IMO this could be really beautifully done in GOOPS, by defining
>> custom metaclasses and slot types.
>
> I've been considering that, and I'm still having doubts.
> The main reason is that there's no documented way
> of accessing GOOPS objects from C (except from using
> scm_c_eval_string etc.), or at least I couldn't find any
> documentation for that.

Yes, that's a fair point.  And one that keeps coming up.  I hope we
can remedy this some time soon.

> Besides (which is the matter of personal taste), I don't
> like the idea of using generics and trashing the global
> namespace with them. (I mean, the sole idea of generics
> is fine, but I wouldn't want to be forced to use them)

They can of course be confined to modules, like any other names.

> I also get this unpleasant feeling that all these 'getters'
> and 'setters' are entities multiplied beyond necessity
> (even the infamous C++ doesn't explicate them)

I don't understand you here.  And in any case, getters and setters are
optional.  You can just use slot-ref and slot-set! if you prefer.

> I'm really trying to get close
> to the classical OOP notation: object.method() -- and
> it's probably why I explore the potential of using these
> "poor man's objects"

Unfortunately that's only "classical" for non-Lisp-like languages!
Still, I'd take your point if you said you wanted to write something
that would be familiar to OO programmers in non-Lisp languages.

> But the point is that I saw that there is a 'make-hash-table' function
> available in lisp -- and this lead me to the conclusion that it's probably
> because the scopes/closures/environments implicitly use hash
> tables to store their bindings

Right (more or less).

> (and the same mechanism was given
> explicitly to the programmer).

You mean in the sense that can one create and manipulate a hash table
where the keys are symbols?  I'd certainly agree with that.

> And so I never stopped to believe that (define x 5) is more or
> less equivalent to (hash-set! global-scope 'x 5).

Well yes.... but I'm afraid I'm still not sure how that leads us to
local-eval !  Sorry if I'm being dumb about this!

Regards,
         Neil