refactor the whole damn thing

src/Type/YArray.js

@@ -0,0 +1,87 @@
+import Type from '../Struct/Type'
+import ItemJSON from '../Struct/ItemJSON'
+
+export default class YArray extends Type {
+  forEach (f) {
+    let pos = 0
+    let n = this._start
+    while (n !== null) {
+      let content = n._getContent()
+      for (let i = 0; i < content.length; i++) {
+        pos++
+        let c = content[i]
+        if (!c._deleted) {
+          f(content[i], pos, this)
+        }
+      }
+      n = n._right
+    }
+  }
+  [Symbol.iterator] () {
+    return {
+      next: function () {
+        while (this._item !== null && (this._item._deleted || this._item._content.length <= this._itemElement)) {
+          // item is deleted or itemElement does not exist (is deleted)
+          this._item = this._item._right
+          this._itemElement = 0
+        }
+        if (this._item === null) {
+          return {
+            done: true
+          }
+        } else {
+          return {
+            value: [this._count, this._item._content[this._itemElement++]],
+            done: false
+          }
+        }
+      },
+      _item: this._start,
+      _itemElement: 0,
+      _count: 0
+    }
+  }
+  insert (pos, content) {
+    let left = this._start
+    let right
+    let count = 0
+    while (left !== null && !left._deleted) {
+      if (pos < count + left._content.length) {
+        [left, right] = left._splitAt(pos - count)
+        break
+      }
+      left = left.right
+    }
+    if (pos > count) {
+      throw new Error('Position exceeds array range!')
+    }
+    let prevJsonIns = null
+    for (let i = 0; i < content.length; i++) {
+      let c = content[i]
+      if (c instanceof Type) {
+        if (prevJsonIns === null) {
+          prevJsonIns._integrate(this._y)
+          prevJsonIns = null
+        }
+        c._left = left
+        c._origin = left
+        c._right = right
+        c._parent = this
+      } else {
+        if (prevJsonIns === null) {
+          prevJsonIns = new ItemJSON()
+          prevJsonIns._origin = left
+          prevJsonIns._left = left
+          prevJsonIns._right = right
+          prevJsonIns._parent = this
+          prevJsonIns._content = []
+        }
+        prevJsonIns._content.push(c)
+      }
+    }
+  }
+  _logString () {
+    let s = super._logString()
+    return 'YArray: ' + s
+  }
+}