use debug_tree::*; fn factors(x: usize) { add_branch!("{}", x); // <~ THE MAGIC LINE for i in 1..x { if x % i == 0 { factors(i); } } } fn main() { // output to file at the end of this block defer_write!("examples/out/fibonacci.txt"); add_branch!("A Fibonacci Tree"); factors(6); add_leaf!("That's All Folks!"); }