message: Renamed _processStack to stack. Also cleaned up #process to clone _preprocessStack into stack and work with just stack.
diff: @@ -266,7 +266,7 @@ class PlaybackTree {
  constructor(stack) {
  this.inputStack = stack;
  this._preprocessStack = [];
  - this._processStack = [];
  + this.stack = [];
  }
  preprocess() {
  @@ -306,23 +306,23 @@ class PlaybackTree {
  }
  process() {
  - let _preprocessStack = this._preprocessStack;
  - let _processStack = this._processStack;
  + Object.assign(this.stack, this._preprocessStack);
  + let stack = this.stack;
  let nextNodeAtSameLevel = this.nextNodeAtSameLevel;
  let nextEndNode = this.nextEndNode;
  let previousOpeningNode = this.previousOpeningNode;
  - _preprocessStack.forEach(function(currentCommandNode, index) {
  - let nextCommandNode = _preprocessStack[index + 1];
  + stack.forEach(function(currentCommandNode, currentCommandIndex) {
  + let nextCommandNode = stack[currentCommandIndex + 1];
  if (nextCommandNode) {
  if (currentCommandNode.command.isControlFlowCommand() &&
  !currentCommandNode.command.isEnd()) {
  currentCommandNode.right = nextCommandNode;
  - currentCommandNode.left = nextNodeAtSameLevel(_preprocessStack, index, currentCommandNode.level);
  + currentCommandNode.left = nextNodeAtSameLevel(stack, currentCommandIndex, currentCommandNode.level);
  } else if (nextCommandNode.command.isControlFlowCommand()) {
  let openingNode;
  - openingNode = previousOpeningNode(_preprocessStack, index, currentCommandNode.level);
  + openingNode = previousOpeningNode(stack, currentCommandIndex, currentCommandNode.level);
  if (openingNode && !openingNode.command.isLoop()) {
  - currentCommandNode.next = nextEndNode(_preprocessStack, index, openingNode.level);
  + currentCommandNode.next = nextEndNode(stack, currentCommandIndex, openingNode.level);
  } else {
  currentCommandNode.next = openingNode;
  }
  @@ -330,9 +330,8 @@ class PlaybackTree {
  currentCommandNode.next = nextCommandNode;
  }
  }
  - _processStack.push(currentCommandNode);
  });
  - return this._processStack;
  + return this.stack;
  }
  }
  