Tom Booster wrote:
> I attempting to implement classes in scheme with using
> (let-lambda-let-lambda) this isn't too difficult. My problem is
> attempting to implement this.* of every object.
> For example I can code a function to increment my class variables.
> (set! this.counter (+ this.counter 1))
> Does anyone have a clue of how to implement this class in scheme?
> Thanks Tom
Scheme doesn't actually have 'classes'; what you're using is instead a
'closure.' A closure captures its current environment and uses it in
its body, to produce things like instance variables. To capture a
'class variable,' (quoted because it's not really a 'class variable' in
the OO sense) you might use:
(let ((default 0))
(let ((x default) (y default))
<instance message dispatcher>))))
Here the make-point function captures 'default.'
Because, however, Scheme doesn't have 'classes,' it doesn't have a dot
syntax; you would merely reference 'default' with 'default'.
By the way, this should be on c.l.scheme, not c.l.s.scsh, as it's not