Sift up (source code)

= Sift up

After inserting or lowering a key in a minimum-oriented <binary heap>, compare it with its <parent in a rooted tree>. Exchange them while the moving key is smaller, then continue at its new index. Stop at the <root of a tree> or when the <heap order> is satisfied. This repair assumes the rest of the <binary heap> was valid before the insertion or key decrease.