flow like the river

BACK_BACK/node_modules/d3-binarytree/src/visitAfter.js

@@ -0,0 +1,19 @@
+import Half from "./half.js";
+
+export default function(callback) {
+  var halves = [], next = [], q;
+  if (this._root) halves.push(new Half(this._root, this._x0, this._x1));
+  while (q = halves.pop()) {
+    var node = q.node;
+    if (node.length) {
+      var child, x0 = q.x0, x1 = q.x1, xm = (x0 + x1) / 2;
+      if (child = node[0]) halves.push(new Half(child, x0, xm));
+      if (child = node[1]) halves.push(new Half(child, xm, x1));
+    }
+    next.push(q);
+  }
+  while (q = next.pop()) {
+    callback(q.node, q.x0, q.x1);
+  }
+  return this;
+}