On 01/05/14 13:57, Devon Schudy wrote: > John Cowan wrote: >> Note also that fixnums often go up to 2^60 these days. > > 60-bit fixnums satisfy almost all of the practical need for bignums, > so they'd be a reasonable minimum. That would force 32-bit > implementations to provide bignums or at least fixed-precision boxed > integers (e.g. Java.lang.Long), but avoid unnecessary work for 64-bit > ones.
The situations in which I need integers beyond 2^30 or so are generally: 1) Sizes of files or other byte-vectors. 2) Cryptographic algorithms - the internals thereof, and useful return values such as hashes - often use 32-bit or 64-bit or similar sizes. They're arguably bit vectors rather than numbers, however. 3) Because I'm reading some file format/protocol which has 32-bit or 64-bit fields in it, and need to pass them on. Likewise. The latter suggest the need for some kind of fixed-precision bit vector type, which might support some integer operations defined in terms of twos-complement, perhaps... Which would take the strain off of fixnums. ABS -- Alaric Snell-Pym http://www.snell-pym.org.uk/alaric/
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