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

Michael Sperber sperber at informatik.uni-tuebingen.de
Mon Jan 29 07:57:59 EST 2007


John Cowan <cowan at ccil.org> writes:

> Peter Gavin scripsit:
>
>> 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.

I believe the reason is that otherwise, parens always mark a compound
form where the first subform somehow identifies the operator.
Generally, Scheme seems to often favor uniformity over convenience.

-- 
Cheers =8-} Mike
Friede, Völkerverständigung und überhaupt blabla



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