private static void RotateOpeator(JsBinaryOperator node, JsAstNodeList rightSide)
{
if (rightSide.Count == 0)
{
// the list is empty -- remove the node altogether
node.Parent.ReplaceChild(node, null);
}
else if (rightSide.Count == 1)
{
// the list has only one item -- replace the node with the one item
node.Parent.ReplaceChild(node, rightSide[0]);
}
else if (rightSide.Count == 2)
{
// there are only two items -- rotate the first to the left-hand side
// and replace the right-hand side with the second item
node.Operand1 = rightSide[0];
node.Operand2 = rightSide[1];
}
else
{
// there will still be more than one left in the list after we peel off the
// first one. rotate the first item to the left-hand side
var temp = rightSide[0];
rightSide.RemoveAt(0);
node.Operand1 = temp;
}
}
public override bool ReplaceChild(JsAstNode oldNode, JsAstNode newNode)
{
// if the old node isn't our element list, ignore the cal
if (oldNode == Elements)
{
if (newNode == null)
{
// we want to remove the list altogether
Elements = null;
return(true);
}
else
{
// if the new node isn't an AstNodeList, then ignore the call
JsAstNodeList newList = newNode as JsAstNodeList;
if (newList != null)
{
// replace it
Elements = newList;
return(true);
}
}
}
return(false);
}
public override void Visit(JsAstNodeList node)
{
if (node != null && node.Count > 0)
{
// this is really only ever not-ed when it's the right-hand operand
// of a comma operator, which we flattened to decrease stack recursion.
// so to logical-not this element, we only need to not the last item
// in the list (because all the others are comma-separated)
node[node.Count - 1].Accept(this);
}
}
public void Visit(JsAstNodeList node)
{
if (node != null)
{
// don't bother setting the order of the list itself, just the items
for (var ndx = 0; ndx < node.Count; ++ndx)
{
var item = node[ndx];
if (item != null)
{
item.Accept(this);
}
}
}
}
public void Visit(JsAstNodeList node)
{
if (node != null)
{
for (var ndx = 0; ndx < node.Count; ++ndx)
{
if (ndx > 0)
{
m_writer.Write(',');
}
if (node[ndx] != null)
{
node[ndx].Accept(this);
}
}
}
}
public override bool ReplaceChild(JsAstNode oldNode, JsAstNode newNode)
{
if (Expression == oldNode)
{
Expression = newNode;
return(true);
}
if (Cases == oldNode)
{
JsAstNodeList newList = newNode as JsAstNodeList;
if (newNode == null || newList != null)
{
// remove it
Cases = newList;
return(true);
}
}
return(false);
}
/// <summary>
/// an astlist is equivalent to another astlist if they both have the same number of
/// items, and each item is equivalent to the corresponding item in the other
/// </summary>
/// <param name="otherNode"></param>
/// <returns></returns>
public override bool IsEquivalentTo(JsAstNode otherNode)
{
bool isEquivalent = false;
JsAstNodeList otherList = otherNode as JsAstNodeList;
if (otherList != null && m_list.Count == otherList.Count)
{
// now assume it's true unless we come across an item that ISN'T
// equivalent, at which case we'll bail the test.
isEquivalent = true;
for (var ndx = 0; ndx < m_list.Count; ++ndx)
{
if (!m_list[ndx].IsEquivalentTo(otherList[ndx]))
{
isEquivalent = false;
break;
}
}
}
return(isEquivalent);
}
public void Visit(JsAstNodeList node)
{
// shoudn't get here
Debug.Fail("shouldn't get here");
}
public void Visit(JsAstNodeList node)
{
// not applicable; terminate
}
public static JsAstNode CombineWithComma(JsContext context, JsParser parser, JsAstNode operand1, JsAstNode operand2)
{
var comma = new JsCommaOperator(context, parser);
// if the left is a comma-operator already....
var leftBinary = operand1 as JsBinaryOperator;
var rightBinary = operand2 as JsBinaryOperator;
if (leftBinary != null && leftBinary.OperatorToken == JsToken.Comma)
{
// the left-hand side is already a comma operator. Instead of nesting these, we're
// going to combine them
// move the old list's left-hand side to our left-hand side
comma.Operand1 = leftBinary.Operand1;
JsAstNodeList list;
if (rightBinary != null && rightBinary.OperatorToken == JsToken.Comma)
{
// the right is ALSO a comma operator. Create a new list, append all the rest of the operands
// and set our right-hand side to be the list
list = new JsAstNodeList(null, parser);
list.Append(leftBinary.Operand2).Append(rightBinary.Operand1).Append(rightBinary.Operand2);
}
else
{
// the right is not a comma operator.
// see if the left-hand side already has a list we can use
list = leftBinary.Operand2 as JsAstNodeList;
if (list == null)
{
// it's not a list already
// create a new list with the left's right and our right and set it to our right
list = new JsAstNodeList(null, parser);
list.Append(leftBinary.Operand2);
}
// and add our right-hand operand to the end of the list
list.Append(operand2);
}
// set the list on the right
comma.Operand2 = list;
}
else if (rightBinary != null && rightBinary.OperatorToken == JsToken.Comma)
{
// the left hand side is NOT a comma operator.
comma.Operand1 = operand1;
// the right-hand side is already a comma-operator, but the left is not.
// see if it already has a list we can reuse
var rightList = rightBinary.Operand2 as JsAstNodeList;
if (rightList != null)
{
// it does. Prepend its right-hand operand and use the list
rightList.Insert(0, rightBinary.Operand1);
}
else
{
// it's not -- create a new list containing the operands
rightList = new JsAstNodeList(rightBinary.Context, parser);
rightList.Append(rightBinary.Operand1);
rightList.Append(rightBinary.Operand2);
}
comma.Operand2 = rightList;
}
else
{
comma.Operand1 = operand1;
comma.Operand2 = operand2;
}
return(comma);
}
private void PossiblyBreakExpressionList(JsBinaryOperator node, JsBlock parentBlock, JsAstNodeList nodeList)
{
// if the first item can be broken, then we an break it and be done.
// otherwise we're going to have to walk until we find a breaking place
if (CanBeBroken(nodeList[0]))
{
// break the first item. insert the left-hand side at our position and
// recurse it. Then rotate the node.
var index = parentBlock.IndexOf(node);
var temp = node.Operand1;
RotateOpeator(node, nodeList);
parentBlock.Insert(index, temp);
// assumes nothing will cause the node to be deleted, because then it
// would cause us to miss the following item
temp.Accept(this);
}
else
{
// the first one can't be broken, so find the first one that can (if any)
for (var ndx = 1; ndx < nodeList.Count; ++ndx)
{
if (CanBeBroken(nodeList[ndx]))
{
if (ndx == 1)
{
// the second item is where we are breaking it, so we're going to pull
// the first item, replace the list with that first item, then insert
// a new comma operator after the current node
var temp = nodeList[0];
nodeList.RemoveAt(0);
node.Operand2 = temp;
// if there's nothing left, then let it die. Otherwise split off
// the remainder and insert after the current item.
if (nodeList.Count > 0)
{
parentBlock.InsertAfter(node, CreateSplitNodeFromEnd(nodeList, 0));
}
}
else
{
// split off items from the index where we want to split, and insert
// it after the current node and leave the node list where it is.
parentBlock.InsertAfter(node, CreateSplitNodeFromEnd(nodeList, ndx));
}
// and now that we've broken it, bail.
break;
}
}
// regardless if anything changed, recurse this node now
base.Visit(node);
}
}
private static JsAstNode CreateSplitNodeFromEnd(JsAstNodeList nodeList, int ndx)
{
JsAstNode newNode;
if (ndx == nodeList.Count - 1)
{
// the LAST one can be broken. Pull it off the list and we will just
// insert it after the current node.
newNode = nodeList[ndx];
nodeList.RemoveAt(ndx);
}
else if (ndx == nodeList.Count - 2)
{
// the PENULTIMATE item can be broken. So create a new comma operator
// with the just the last two item and we'll insert it after the current node
var left = nodeList[ndx];
nodeList.RemoveAt(ndx);
var right = nodeList[ndx];
nodeList.RemoveAt(ndx);
newNode = new JsCommaOperator(null, nodeList.Parser)
{
Operand1 = left,
Operand2 = right
};
}
else
{
// at least three items will be pulled off, which means there will
// be at least two items on the right, so we'll create a new astlist to
// insert those items into a new comma operator
var left = nodeList[ndx];
nodeList.RemoveAt(ndx);
// if we were passed zero, then just reuse the node list.
// otherwise we need to create a new one and move the items
// from the index position over.
JsAstNodeList right;
if (ndx == 0)
{
right = nodeList;
}
else
{
right = new JsAstNodeList(null, nodeList.Parser);
while (ndx < nodeList.Count)
{
var temp = nodeList[ndx];
nodeList.RemoveAt(ndx);
right.Append(temp);
}
}
newNode = new JsCommaOperator(null, nodeList.Parser)
{
Operand1 = left,
Operand2 = right
};
}
return(newNode);
}
