Not sure if I remember correctly, but is not the modBy 0 1 runtime exception an expected behavior? I think this was left as it is for performances reason. If performance is not needed, it is possible to wrap it in a safeModBy that adds a check for the parameter to be non-zero.
safeModBy : Int -> Int -> Maybe Int
safeModBy a b =
if a == 0 then
Nothing
else
Just (modBy a b)
Maybe unsafeModBy could be a better name for modBy?
It would be interesting to prioritize issues based on several factors. For example: do they have a workaround? How expensive is it? How popular is the package/function with the issue?