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Re: Reasons, why Miss Scheme should collect her garbage beforeshutdown.

> garbage collection is used for managing memory, not for managing
> other resources
... because: ...
> even when your object is finalised you can't guarantee when that
> will happen.

This finally makes me understand and is so logical ... blindness must
have struck me before!
Besides, what triggers garbage-collection?

> Better is to provide an explicit means of freeing/closing resources.
> A common idiom in Common Lisp and Dylan is to do a 'with...' style
> macro:
>   with-open-file(fs = "blah.txt")
>     do-something(fs);
>   end;
> The macro frees or closes the resources at the end of the scope.

I see: I should use a defmacro or a syntax-case-macro to transform
something like this:

(with-external-objects ((obj (make-external-object args)))
  (operate-on-external-object obj)

... into this:

(let ((obj (make-external-object args)))
  (operate-on-external-object obj)
  (clear-external-object obj))

... or this:

(let ((obj (make-external-object args)))
     (lambda () #f)
     (lambda ()
        (operate-on-external-object obj)
     (lambda () (clear-external-object obj))))

The second variant should clear the external object if a continuation
is used to jump out of the scope of the 'with-...'-form. Though I'm
not quite sure if this is absolutely 'continuation-proof', the
external object will at least never remain un-freed.

I will redo my program in this fashion and then it shall be simpler
and more robust.