On 11 Aug 2014, at 22:15, koko <k...@highrolls.net> wrote: > In computing, the modulo (sometimes called modulus) operation finds the > remainder of division of one number by another. > Given two positive numbers, a (the dividend) and n (the divisor), a modulo n > (abbreviated as a mod n) is the remainder of theEuclidean division of a by n. > For instance, the expression "5 mod 2" would evaluate to 1 because 5 divided > by 2 leaves aquotient of 2 and a remainder of 1, while "9 mod 3" would > evaluate to 0 because the division of 9 by 3 has a quotient of 3 and leaves a > remainder of 0; there is nothing to subtract from 9 after multiplying 3 times > 3. (Note that doing the division with a calculator won't show the result > referred to here by this operation; the quotient will be expressed as a > decimal fraction.) > Although typically performed with a and n both being integers, many computing > systems allow other types of numeric operands. The range of numbers for an > integer modulo of n is 0 to n − 1. (n mod 1 is always 0; n mod 0 is > undefined, possibly resulting in a "Division by zero" error in computer > programming languages) See modular arithmetic for an older and related > convention applied in number theory. > When either a or n is negative, the naive definition breaks down and > programming languages differ in how these values are defined.
Well put! In my mind, the logical thing to do is to return the reverse sequence as per mod function I copied. This makes more sense when using Cocoa because it means you can easily treat NSArray’s as circular lists without having to worry about edge conditions. Cheers Dave _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
