static void RotateOpeator(BinaryExpression node, AstNodeList 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;
}
}
void PossiblyBreakExpressionList(BinaryExpression node, BlockStatement parentBlock, AstNodeList 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);
}
}
static AstNode CreateSplitNodeFromEnd(AstNodeList nodeList, int ndx)
{
AstNode 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 CommaExpression(left.Context.FlattenToStart())
{
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.
AstNodeList right;
if (ndx == 0)
{
right = nodeList;
}
else
{
right = new AstNodeList(nodeList[ndx].Context.FlattenToStart());
while (ndx < nodeList.Count)
{
var temp = nodeList[ndx];
nodeList.RemoveAt(ndx);
right.Append(temp);
}
}
newNode = new CommaExpression(left.Context.FlattenToStart())
{
Operand1 = left,
Operand2 = right
};
}
return(newNode);
}
