there would also be room for infix...
but i just thought about that this actually looks like another kind of split operation, instead of spliting on certain elements this will split on positions.
prefix would be split(foo, 17)[0]; postfix would be split(foo, 17)[1];
but you could split on any number of positions: [pre, in1, in2, post] = split(foo, 5, 7, 17);
greetings, martin.