[r6rs-discuss] [Formal] Expand the set of self-evaluating datums

R. Kent Dybvig dyb at cs.indiana.edu
Sat Jan 27 15:07:05 EST 2007


> > I don't think the empty list should be self-evaluating.  No other list
> > in scheme is self-evaluating, so why should the empty one be?
>
> Because it can be neither syntax (which must have a keyword) nor a function call
> (which must have at least one form).  Making () self-evaluating also represents
> a return to Lisp tradition; it would be interesting to know why it was made
> *not* self-evaluating in RRRS.

As I recall, those who wanted the potential expression () not to be
self-evaluating considered it the "empty application" and, as such,
syntactically malformed.

Kent



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