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Re: [Chicken-users] Bignums in core
From: |
John Cowan |
Subject: |
Re: [Chicken-users] Bignums in core |
Date: |
Sun, 4 Oct 2009 01:39:41 -0400 |
User-agent: |
Mutt/1.5.13 (2006-08-11) |
Kon Lovett scripsit:
> I am not defending the lack of bignums in Chicken. Just trying to
> understand the need.
I think at this point it's about what people expect from a Scheme.
Of the pre-R6RS implementations I tested, all of PLT, Gauche, MIT Scheme,
Gambit, Bigloo, Scheme48/scsh, Guile, Kawa, SISC, Chez, SCM, STklos,
and even tiny Chibi provide bignums. In effect, bignums have become
part of what a Scheme is. Most of these systems limit bignums in one
way or another to a size far less than all of memory, but all of them
AFAIK handle numbers up to at least 2^(2^15).
Scraping the bottom of the implementation barrel, SigScheme has 28-bit
fixnums and signals an error if you overflow them; however, bignum
literals are interpreted as flonums. SXM and S7, which are extremely
minimal, wrap at 31 bits and 64 bits respectively, which is not even
R5RS-conformant; SXM actually crashes if it reads a bignum literal.
Chicken and only Chicken converts fixnum operations to flonums on
overflow. This behavior is certainly licensed by R5RS, but it doesn't
fit very well into the Scheme ecology. The numbers egg just isn't a
substitute for bignums in the core (and particularly in the FFI).
--
Normally I can handle panic attacks on my own; John Cowan <address@hidden>
but panic is, at the moment, a way of life. http://www.ccil.org/~cowan
- Re: [Chicken-users] set-file-position! only works with fixnums, Thomas Bushnell BSG, 2009/10/01
- Re: [Chicken-users] set-file-position! only works with fixnums, John Cowan, 2009/10/01
- Re: [Chicken-users] set-file-position! only works with fixnums, Kon Lovett, 2009/10/01
- Re: [Chicken-users] set-file-position! only works with fixnums, John Cowan, 2009/10/02
- Re: [Chicken-users] set-file-position! only works with fixnums, Thomas Bushnell BSG, 2009/10/02
- Re: [Chicken-users] set-file-position! only works with fixnums, Kon Lovett, 2009/10/02
- [Chicken-users] Bignums in core, Kon Lovett, 2009/10/02
- Re: [Chicken-users] Bignums in core, John Cowan, 2009/10/03
- Re: [Chicken-users] Bignums in core, Kon Lovett, 2009/10/03
- Re: [Chicken-users] Bignums in core,
John Cowan <=
- Re: [Chicken-users] Bignums in core, Nicholas \"Indy\" Ray, 2009/10/04
- Re: [Chicken-users] Bignums in core, Thomas Bushnell BSG, 2009/10/04
- Re: [Chicken-users] Bignums in core, Nicholas \"Indy\" Ray, 2009/10/04
- Re: [Chicken-users] Bignums in core, John Cowan, 2009/10/04
- Re: [Chicken-users] Bignums in core, Ivan Raikov, 2009/10/04
- Re: [Chicken-users] Bignums in core, Kon Lovett, 2009/10/05
- Re: [Chicken-hackers] Re: [Chicken-users] Bignums in core, Peter Bex, 2009/10/06
- Re: [Chicken-hackers] Re: [Chicken-users] Bignums in core, John Cowan, 2009/10/06
- Re: [Chicken-users] Bignums in core, Thomas Bushnell BSG, 2009/10/04
- [Chicken-users] Re: Bignums in core, Thomas Bushnell BSG, 2009/10/04