/// <summary>
/// Adds a child without performing any safety checks.
/// </summary>
internal void AddChildUnsafe(AstNode child, Role role)
{
child.parent = this;
child.SetRole(role);
if (firstChild == null)
{
lastChild = firstChild = child;
}
else
{
lastChild.nextSibling = child;
child.prevSibling = lastChild;
lastChild = child;
}
}
void InsertChildBeforeUnsafe(AstNode nextSibling, AstNode child, Role role)
{
child.parent = this;
child.SetRole(role);
child.nextSibling = nextSibling;
child.prevSibling = nextSibling.prevSibling;
if (nextSibling.prevSibling != null)
{
Debug.Assert(nextSibling.prevSibling.nextSibling == nextSibling);
nextSibling.prevSibling.nextSibling = child;
}
else
{
Debug.Assert(firstChild == nextSibling);
firstChild = child;
}
nextSibling.prevSibling = child;
}
/// <summary>
/// Replaces this node with the new node.
/// </summary>
public void ReplaceWith(AstNode newNode)
{
if (newNode == null || newNode.IsNull)
{
Remove();
return;
}
if (newNode == this)
{
return; // nothing to do...
}
if (parent == null)
{
throw new InvalidOperationException(this.IsNull ? "Cannot replace the null nodes" : "Cannot replace the root node");
}
ThrowIfFrozen();
// Because this method doesn't statically check the new node's type with the role,
// we perform a runtime test:
if (!this.Role.IsValid(newNode))
{
throw new ArgumentException(string.Format("The new node '{0}' is not valid in the role {1}", newNode.GetType().Name, this.Role.ToString()), "newNode");
}
if (newNode.parent != null)
{
// newNode is used within this tree?
if (newNode.Ancestors.Contains(this))
{
// e.g. "parenthesizedExpr.ReplaceWith(parenthesizedExpr.Expression);"
// enable automatic removal
newNode.Remove();
}
else
{
throw new ArgumentException("Node is already used in another tree.", "newNode");
}
}
if (newNode.IsFrozen)
{
throw new ArgumentException("Cannot add a frozen node.", "newNode");
}
newNode.parent = parent;
newNode.SetRole(this.Role);
newNode.prevSibling = prevSibling;
newNode.nextSibling = nextSibling;
if (prevSibling != null)
{
Debug.Assert(prevSibling.nextSibling == this);
prevSibling.nextSibling = newNode;
}
else
{
Debug.Assert(parent.firstChild == this);
parent.firstChild = newNode;
}
if (nextSibling != null)
{
Debug.Assert(nextSibling.prevSibling == this);
nextSibling.prevSibling = newNode;
}
else
{
Debug.Assert(parent.lastChild == this);
parent.lastChild = newNode;
}
parent = null;
prevSibling = null;
nextSibling = null;
}