Java Code Examples for com.google.javascript.rhino.Node#detachChildren()

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.isCall()) {
    Node target = n.getFirstChild();
    // TODO(johnlenz): add this to the coding convention
    // so we can remove goog.reflect.sinkValue as well.
    if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
      Node expr = n.getLastChild();
      n.detachChildren();
      parent.replaceChild(n, expr);
    }
  }
}
 

/**
 * Try to fold an array join: ['a', 'b', 'c'].join('') -> 'abc';
 */
void tryFoldStringJoin(NodeTraversal t, Node n, Node left, Node right,
                       Node parent) {
  if (!NodeUtil.isGetProp(left) || !NodeUtil.isImmutableValue(right)) {
    return;
  }

  Node arrayNode = left.getFirstChild();
  Node functionName = arrayNode.getNext();

  if ((arrayNode.getType() != Token.ARRAYLIT) ||
      !functionName.getString().equals("join")) {
    return;
  }

  String joinString = NodeUtil.getStringValue(right);
  List<Node> arrayFoldedChildren = Lists.newLinkedList();
  StringBuilder sb = new StringBuilder();
  int foldedSize = 0;
  Node elem = arrayNode.getFirstChild();
  // Merges adjacent String nodes.
  while (elem != null) {
    if (NodeUtil.isImmutableValue(elem)) {
      if (sb.length() > 0) {
        sb.append(joinString);
      }
      sb.append(NodeUtil.getStringValue(elem));
    } else {
      if (sb.length() > 0) {
        // + 2 for the quotes.
        foldedSize += sb.length() + 2;
        arrayFoldedChildren.add(Node.newString(sb.toString()));
        sb = new StringBuilder();
      }
      foldedSize += InlineCostEstimator.getCost(elem);
      arrayFoldedChildren.add(elem);
    }
    elem = elem.getNext();
  }

  if (sb.length() > 0) {
    // + 2 for the quotes.
    foldedSize += sb.length() + 2;
    arrayFoldedChildren.add(Node.newString(sb.toString()));
  }
  // one for each comma.
  foldedSize += arrayFoldedChildren.size() - 1;

  int originalSize = InlineCostEstimator.getCost(n);
  switch (arrayFoldedChildren.size()) {
    case 0:
      Node emptyStringNode = Node.newString("");
      parent.replaceChild(n, emptyStringNode);
      break;

    case 1:
      Node foldedStringNode = arrayFoldedChildren.remove(0);
      if (foldedSize > originalSize) {
        return;
      }
      arrayNode.detachChildren();
      if (foldedStringNode.getType() != Token.STRING) {
        // If the Node is not a string literal, ensure that
        // it is coerced to a string.
        Node replacement = new Node(Token.ADD,
            Node.newString(""), foldedStringNode);
        foldedStringNode = replacement;
      }
      parent.replaceChild(n, foldedStringNode);
      break;

    default:
      // No folding could actually be performed.
      if (arrayFoldedChildren.size() == arrayNode.getChildCount()) {
        return;
      }
      int kJoinOverhead = "[].join()".length();
      foldedSize += kJoinOverhead;
      foldedSize += InlineCostEstimator.getCost(right);
      if (foldedSize > originalSize) {
        return;
      }
      arrayNode.detachChildren();
      for (Node node : arrayFoldedChildren) {
        arrayNode.addChildToBack(node);
      }
      break;
  }
  t.getCompiler().reportCodeChange();
}
 

/**
 *
 * @param expr The conditional expression to extract.
 * @param injectionPoint The before which extracted expression, would be
 *     injected.
 * @param needResult  Whether the result of the expression is required.
 * @return The node that contains the logic of the expression after
 *     extraction.
 */
private Node extractConditional(
    Node expr, Node injectionPoint, boolean needResult) {
  Node parent = expr.getParent();
  String tempName = getTempValueName();

  // Break down the conditional.
  Node first = expr.getFirstChild();
  Node second = first.getNext();
  Node last = expr.getLastChild();

  // Isolate the children nodes.
  expr.detachChildren();

  // Transform the conditional to an IF statement.
  Node cond = null;
  Node trueExpr = IR.block().srcref(expr);
  Node falseExpr = IR.block().srcref(expr);
  switch (expr.getType()) {
    case Token.HOOK:
      // a = x?y:z --> if (x) {a=y} else {a=z}
      cond = first;
      trueExpr.addChildToFront(NodeUtil.newExpr(
          buildResultExpression(second, needResult, tempName)));
      falseExpr.addChildToFront(NodeUtil.newExpr(
          buildResultExpression(last, needResult, tempName)));
      break;
    case Token.AND:
      // a = x&&y --> if (a=x) {a=y} else {}
      cond = buildResultExpression(first, needResult, tempName);
      trueExpr.addChildToFront(NodeUtil.newExpr(
          buildResultExpression(last, needResult, tempName)));
      break;
    case Token.OR:
      // a = x||y --> if (a=x) {} else {a=y}
      cond = buildResultExpression(first, needResult, tempName);
      falseExpr.addChildToFront(NodeUtil.newExpr(
          buildResultExpression(last, needResult, tempName)));
      break;
    default:
      // With a valid tree we should never get here.
      throw new IllegalStateException("Unexpected.");
  }

  Node ifNode;
  if (falseExpr.hasChildren()) {
    ifNode = IR.ifNode(cond, trueExpr, falseExpr);
  } else {
    ifNode = IR.ifNode(cond, trueExpr);
  }
  ifNode.copyInformationFrom(expr);

  if (needResult) {
    Node tempVarNode = NodeUtil.newVarNode(tempName, null)
        .copyInformationFromForTree(expr);
    Node injectionPointParent = injectionPoint.getParent();
    injectionPointParent.addChildBefore(tempVarNode, injectionPoint);
    injectionPointParent.addChildAfter(ifNode, tempVarNode);

    // Replace the expression with the temporary name.
    Node replacementValueNode = IR.name(tempName);
    parent.replaceChild(expr, replacementValueNode);
  } else {
    // Only conditionals that are the direct child of an expression statement
    // don't need results, for those simply replace the expression statement.
    Preconditions.checkArgument(parent.isExprResult());
    Node gramps = parent.getParent();
    gramps.replaceChild(parent, ifNode);
  }

  return ifNode;
}