flow like the river

VISUALIZACION/node_modules/d3-binarytree/src/add.js

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+export default function(d) {
+  const x = +this._x.call(null, d);
+  return add(this.cover(x), x, d);
+}
+
+function add(tree, x, d) {
+  if (isNaN(x)) return tree; // ignore invalid points
+
+  var parent,
+      node = tree._root,
+      leaf = {data: d},
+      x0 = tree._x0,
+      x1 = tree._x1,
+      xm,
+      xp,
+      right,
+      i,
+      j;
+
+  // If the tree is empty, initialize the root as a leaf.
+  if (!node) return tree._root = leaf, tree;
+
+  // Find the existing leaf for the new point, or add it.
+  while (node.length) {
+    if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
+    if (parent = node, !(node = node[i = +right])) return parent[i] = leaf, tree;
+  }
+
+  // Is the new point is exactly coincident with the existing point?
+  xp = +tree._x.call(null, node.data);
+  if (x === xp) return leaf.next = node, parent ? parent[i] = leaf : tree._root = leaf, tree;
+
+  // Otherwise, split the leaf node until the old and new point are separated.
+  do {
+    parent = parent ? parent[i] = new Array(2) : tree._root = new Array(2);
+    if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
+  } while ((i = +right) === (j = +(xp >= xm)));
+  return parent[j] = node, parent[i] = leaf, tree;
+}
+
+export function addAll(data) {
+  if (!Array.isArray(data)) data = Array.from(data);
+  const n = data.length;
+  const xz = new Float64Array(n);
+  let x0 = Infinity,
+      x1 = -Infinity;
+
+  // Compute the points and their extent.
+  for (let i = 0, x; i < n; ++i) {
+    if (isNaN(x = +this._x.call(null, data[i]))) continue;
+    xz[i] = x;
+    if (x < x0) x0 = x;
+    if (x > x1) x1 = x;
+  }
+
+  // If there were no (valid) points, abort.
+  if (x0 > x1) return this;
+
+  // Expand the tree to cover the new points.
+  this.cover(x0).cover(x1);
+
+  // Add the new points.
+  for (let i = 0; i < n; ++i) {
+    add(this, xz[i], data[i]);
+  }
+
+  return this;
+}