[Issue 350] Modulo for negative values is undefined

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=350





------- Comment #2 from deewiant at gmail.com  2006-09-17 01:35 -------
import std.stdio : writefln;
import std.stdio : writefln;

void main() {
        writefln(-1 % 10);
        writefln(-1 % 5);
        writefln(-1 % 3);
        writefln(-1 % 2);
        writefln(-2 % 8);
        writefln(-28 % 7);
        writefln(-1 % -1);
        writefln(-2 % -2);
        writefln(-9 % -2);
        writefln(8 % -2);
        writefln(16 % -2);
        writefln(9 % -2);
        writefln(5 % -4);
}
--
Where both values are negative, it gives the correct answer.

Where only the dividend or divisor is negative, it appears to return
(remainder-divisor) instead of just the remainder. Following your link, it
seems that this is the so-called "trunc-mod", common in many other programming
languages.

I'm sorry, I was in a bit of a hurry when I posted this report and couldn't be
bothered to take a detailed look at the issue.

Anyhoo, a mention in the spec would be nice.


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