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*To*: Thomas Bushnell BSG <tb@xxxxxxxxxx>*Subject*: Re: arithmetic issues*From*: "John.Cowan" <jcowan@xxxxxxxxxxxxxxxxx>*Date*: Sun, 23 Oct 2005 12:02:47 -0400*Cc*: bear <bear@xxxxxxxxx>, Aubrey Jaffer <agj@xxxxxxxxxxxx>, srfi-77@xxxxxxxxxxxxxxxxx*Delivered-to*: srfi-77@xxxxxxxxxxxxxxxxx*In-reply-to*: <87r7adv5ii.fsf@xxxxxxxxxxxxxxxxx>*References*: <20051021145326.816C11B77BB@xxxxxxxxxxxxxxxxxxxxx> <20051021155906.GC16464@NYCMJCOWA2> <Pine.LNX.4.58.0510210910130.18969@xxxxxxxxxxxxxx> <20051022020312.GB5632@NYCMJCOWA2> <87mzl2mhd3.fsf@xxxxxxxxxxxxxxxxx> <20051022023824.GD5632@NYCMJCOWA2> <87r7adv5ii.fsf@xxxxxxxxxxxxxxxxx>*User-agent*: Mutt/1.4.2.1i

Thomas Bushnell BSG scripsit: > > Thomas Bushnell BSG scripsit: > > > >> > Can you live with 2^24? > >> > >> No. Have you heard of sparse arrays? They need indices too. > > > > Sparse arrays are not a fundamental R[56]RS type like strings and vectors. > > The question is whether these native types need to be Really Really Big. > > Huh? Sparse arrays are an *implementation* not a datatype. Granted, Scheme vectors could be implemented as sparse arrays (and Scheme strings as cords). For that matter, both could be implemented as lists, given a magic first cell that makes them disjoint from Scheme lists. And for that mattter, Scheme lists could be implemented as machine-level vectors, provided you are willing to live with all the behind-the-scenes copying that would be required. Numbers could be Church numerals, and so on. But if Scheme vectors don't have O(1) performance (actually O(log k) on modern hardware) in a given implementation, users are likely to vote with their feet. -- A rabbi whose congregation doesn't want John Cowan to drive him out of town isn't a rabbi, http://www.ccil.org/~cowan and a rabbi who lets them do it jcowan@xxxxxxxxxxxxxxxxx isn't a man. --Jewish saying http://www.reutershealth.com

**Follow-Ups**:**Re: arithmetic issues***From:*Thomas Bushnell BSG

**References**:**arithmetic issues***From:*Aubrey Jaffer

**Re: arithmetic issues***From:*John.Cowan

**Re: arithmetic issues***From:*bear

**Re: arithmetic issues***From:*John.Cowan

**Re: arithmetic issues***From:*Thomas Bushnell BSG

**Re: arithmetic issues***From:*John.Cowan

**Re: arithmetic issues***From:*Thomas Bushnell BSG

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