feat(ui): add type filter toggles

node_modules/dagre/lib/data/list.js

@@ -0,0 +1,56 @@
+/*
+ * Simple doubly linked list implementation derived from Cormen, et al.,
+ * "Introduction to Algorithms".
+ */
+
+module.exports = List;
+
+function List() {
+  var sentinel = {};
+  sentinel._next = sentinel._prev = sentinel;
+  this._sentinel = sentinel;
+}
+
+List.prototype.dequeue = function() {
+  var sentinel = this._sentinel;
+  var entry = sentinel._prev;
+  if (entry !== sentinel) {
+    unlink(entry);
+    return entry;
+  }
+};
+
+List.prototype.enqueue = function(entry) {
+  var sentinel = this._sentinel;
+  if (entry._prev && entry._next) {
+    unlink(entry);
+  }
+  entry._next = sentinel._next;
+  sentinel._next._prev = entry;
+  sentinel._next = entry;
+  entry._prev = sentinel;
+};
+
+List.prototype.toString = function() {
+  var strs = [];
+  var sentinel = this._sentinel;
+  var curr = sentinel._prev;
+  while (curr !== sentinel) {
+    strs.push(JSON.stringify(curr, filterOutLinks));
+    curr = curr._prev;
+  }
+  return "[" + strs.join(", ") + "]";
+};
+
+function unlink(entry) {
+  entry._prev._next = entry._next;
+  entry._next._prev = entry._prev;
+  delete entry._next;
+  delete entry._prev;
+}
+
+function filterOutLinks(k, v) {
+  if (k !== "_next" && k !== "_prev") {
+    return v;
+  }
+}