Depth-first searching of a tree using generators.

DFSgenerators.js

class Tree {
 constructor(value = null, children = []) {
   this.value = value;
   this.children = children;
 }
  
  *printValues() {
    yield this.value;
    for(let child of this.children) {
      yield* child.printValues; 
    }
  }
}

const tree = new Tree(1, [
  new Tree(2, [new Tree(4)]),
  new Tree(3)
]);

const values = [];
for (let value of tree.printValues()) {
  values.push(value); 
}

// [1, 2, 4, 3]