How do you do modulo or remainder in Erlang?
The erlang modulo operator is rem
Eshell V5.6.4 (abort with ^G)
1> 97 rem 10.
7
In Erlang, 5 rem 3.
gives 2
, and -5 rem 3.
gives -2
. If I understand your question, you would want -5 rem 3.
to give 1 instead, since -5 = -2 * 3 + 1.
Does this do what you want?
mod(X,Y) when X > 0 -> X rem Y;
mod(X,Y) when X < 0 -> Y + X rem Y;
mod(0,Y) -> 0.
I used the following in elixir:
defp mod(x,y) when x > 0, do: rem(x, y);
defp mod(x,y) when x < 0, do: rem(x, y) + y;
defp mod(0,_y), do: 0
According to this blog post, it's rem
.