The modulo operation should always return positive values:
mod(-1, 8) = 7
mod(-9, 8) = 6
While the remainder operation can return negative values:
-1%8 = -1
-9%8 = -1
Construct and it's documentation seems to treat both as the same thing, and only provides us with the remainder operation, unless I'm missing something... Would be cool to see the actual modulo operation in a future version.~
Oh and for a workaround, in able to "convert" the existing remainder operation to a modulo operation you can use this expression:
(a%b + b) % b[/code:oeckpjgt]
This will return mod(a, b), always an integer between 0 and b-1.