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[Caml-list] Integer arithmetic: mod
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Kai Kaminski
- Chris Hecker
- John Max Skaller
- Xavier Leroy
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| Date: | -- (:) |
| From: | John Max Skaller <skaller@m...> |
| Subject: | Re: [Caml-list] Integer arithmetic: mod |
Kai Kaminski wrote: > > Hi, > > I have a question regarding the 'mod' operator in OCaml. While playing > around with the toplevel, I found that > > -1 mod 10 = -1 instead of -1 mod 10 = 9. > The reason is that whenever such a behaviour is platform-dependent, you > can't use it at all, as long as you want to have your programs portable. Yes you can: it works for non-negative arguments. And you can always roll your own function that works as you desire for negative ones: let mymod x y = if ((x mod y) as r) < 0 then r + y else r which works for negative x provided the result is in the range y .. -1 This way, YOU choose whether you want a deterministic result for non-negative values (use mod, its fast), or are willing to pay extra for determinism for negative values. But I agree with you anyhow. :-) -- John (Max) Skaller, mailto:skaller@maxtal.com.au 10/1 Toxteth Rd Glebe NSW 2037 Australia voice: 61-2-9660-0850 New generation programming language Felix http://felix.sourceforge.net Literate Programming tool Interscript http://Interscript.sourceforge.net ------------------- Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr