# maps
resource "aws_instance" "foo" {
    for_each = {
        a = "thing"
        b = "another thing"
      =>c = "yet another thing"
    }
    num = "3"
}

# sets
resource "aws_instance" "bar" {
    for_˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ces
resource "aws_instance" "boo" {
a"]t" {
    for_each = {
        my_key = aws_instance.boo.foo
    }
    foo = each.value
}