Re: [Scheme-reports] Current tickets for the 5th ballot - 281

[John Cowan <cowan@x>]

Andre van Tonder scripsit:

> > Does it really? Can anyone point to an implementation of EVAL that can't
> > cope with this?
> 
> I don't think Larceny's eval can cope with this.

In fact, Larceny has no trouble with a quoted procedure object in the
car of a form.  Scheme48/scsh is the only implementation that does,
and not (so far as I can judge) because of any internal limitation:
it just checks and blows up.

(define e (interaction-environment))
(define y (list (list 'quote 'cons) 1 2))
(set-car! (cdar y) cons)
(eval x e) => (1 . 2)

-- 
John Cowan  cowan@x  http://ccil.org/~cowan
The competent programmer is fully aware of the strictly limited size of his own
skull; therefore he approaches the programming task in full humility, and among
other things he avoids clever tricks like the plague.  --Edsger Dijkstra

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