Sujet : Re: Church numerals in early lisp implementations?
De : alan (at) *nospam* csail.mit.edu (Alan Bawden)
Groupes : comp.lang.lispDate : 12. May 2024, 03:43:22
Autres entêtes
Organisation : ITS Preservation Society
Message-ID : <86frun24at.fsf@williamsburg.bawden.org>
References : 1
User-Agent : Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux)
Julieta Shem <
jshem@yaxenu.org> writes:
McCarthy wrote this in ``History of Lisp''.
> Numbers were originally implemented in LISP I as lists of atoms, and
> this proved too slow for all but the simplest computations.
Was that Church numerals?
Certainly not.
The "atoms" is question were probably machine words containing the
digits of the number in some suitable base. I would guess base 2^36 or
2^35, depending on how they chose to represent negative numbers --
similar to the way GMP still works today. But I don't know for sure.
I've never seen this documented anywhere.
- Alan