Re: Why is -1 mod 5 not equal to 4? (it is -1)

[cantanima]

Actually, you ask 2 questions, the title is only the 1st. ;-)

The answer to the first question is that `mod` translates to C's `%`, and the 
specification for `%` in C is that negative numbers gives negative results; 
that is, `-5 % 4 == 1` in C.

I can think of more than one answer to the second question. The simplest (?) is 
probably to take the absolute value before computing the modulus: 
    
    
    var a = -5
    var b = 4
    echo a mod b # gives -1
    echo abs(a) mod b # gives 1
    
    
    Run