outsourcing some code. custom types definition change

src/Utils.js

@@ -0,0 +1,100 @@
+
+var GeneratorFunction = (function*(){}).constructor;//eslint-disable-line
+
+class EventHandler { //eslint-disable-line
+  constructor (onevent) {
+    this.waiting = [];
+    this.awaiting = 0;
+    this.onevent = onevent;
+    this.userEventListeners = [];
+  }
+  receivedOp (op) {
+    if (this.awaiting <= 0) {
+      this.onevent([op]);
+    } else {
+      this.waiting.push(copyObject(op));
+    }
+  }
+  awaitAndPrematurelyCall (ops) {
+    this.awaiting++;
+    this.onevent(ops);
+  }
+  addUserEventListener (f) {
+    this.userEventListeners.push(f);
+  }
+  removeUserEventListener (f) {
+    this.userEventListeners = this.userEventListeners.filter(function(g){
+      return f !== g;
+    });
+  }
+  removeAllUserEventListeners () {
+    this.userEventListeners = [];
+  }
+  callUserEventListeners (event) {
+    for (var i in this.userEventListeners) {
+      try {
+        this.userEventListeners[i](event);
+      } catch (e) {
+        console.log("User events must not throw Errors!");//eslint-disable-line
+      }
+    }
+  }
+  awaitedLastInserts (n) {
+    var ops = this.waiting.splice(this.waiting.length - n);
+    for (var oid = 0; oid < ops.length; oid++) {
+      var op = ops[oid];
+      for (var i = this.waiting.length - 1; i >= 0; i--) {
+        let w = this.waiting[i];
+        if (compareIds(op.left, w.id)) {
+          // include the effect of op in w
+          w.right = op.id;
+          // exclude the effect of w in op
+          op.left = w.left;
+        } else if (compareIds(op.right, w.id)) {
+          // similar..
+          w.left = op.id;
+          op.right = w.right;
+        }
+      }
+    }
+    this.tryCallEvents();
+  }
+  awaitedLastDeletes (n, newLeft) {
+    var ops = this.waiting.splice(this.waiting.length - n);
+    for (var j in ops) {
+      var del = ops[j];
+      if (newLeft != null) {
+        for (var i in this.waiting) {
+          let w = this.waiting[i];
+          // We will just care about w.left
+          if (compareIds(del.target, w.left)) {
+            del.left = newLeft;
+          }
+        }
+      }
+    }
+    this.tryCallEvents();
+  }
+  tryCallEvents () {
+    this.awaiting--;
+    if (this.awaiting <= 0 && this.waiting.length > 0) {
+      var events = this.waiting;
+      this.waiting = [];
+      this.onevent(events);
+    }
+  }
+}
+
+class CustomType { //eslint-disable-line
+  constructor (def) {
+    if (def.createType == null
+      || def.initType == null
+      || def.class == null
+    ) {
+      throw new Error("Custom type was not initialized correctly!");
+    }
+    this.createType = def.createType;
+    this.initType = def.initType;
+    this.class = def.class;
+  }
+}