/// <summary>
/// Prepends a value to the random access list.
/// </summary>
/// <param name="value">
/// The value to prepend to the list.
/// </param>
/// <returns>
/// A new random access list with the specified value prepended to the
/// list.
/// </returns>
public RandomAccessList Cons(object value)
{
RandomAccessList result;
// If the list is empty, or there is only one tree in the list, or
// the first tree is smaller than the second tree.
if (Count == 0 ||
first.NextNode == null ||
first.Root.Count < first.NextNode.Root.Count)
{
// Create a new first node with the specified value.
RalTreeNode newRoot = new RalTreeNode(value, null, null);
// Create a new random access list.
result = new RandomAccessList(
new RalTopNode(newRoot, first),
Count + 1);
}
// Else the first and second trees in the list are the same size.
else
{
Debug.Assert(first.Root.Count == first.NextNode.Root.Count);
// Create a new first node with the old first and second node
// as the left and right children respectively.
RalTreeNode newRoot = new RalTreeNode(
value,
first.Root,
first.NextNode.Root);
// Create a new random access list.
result = new RandomAccessList(
new RalTopNode(newRoot, first.NextNode.NextNode),
Count + 1);
}
return(result);
}
/// <summary>
/// Prepends a value to the random access list.
/// </summary>
/// <param name="value">
/// The value to prepend to the list.
/// </param>
/// <returns>
/// A new random access list with the specified value prepended to the
/// list.
/// </returns>
public RandomAccessList Cons(object value)
{
RandomAccessList result;
// If the list is empty, or there is only one tree in the list, or
// the first tree is smaller than the second tree.
if(Count == 0 ||
first.NextNode == null ||
first.Root.Count < first.NextNode.Root.Count)
{
// Create a new first node with the specified value.
RalTreeNode newRoot = new RalTreeNode(value, null, null);
// Create a new random access list.
result = new RandomAccessList(
new RalTopNode(newRoot, first),
Count + 1);
}
// Else the first and second trees in the list are the same size.
else
{
Debug.Assert(first.Root.Count == first.NextNode.Root.Count);
// Create a new first node with the old first and second node
// as the left and right children respectively.
RalTreeNode newRoot = new RalTreeNode(
value,
first.Root,
first.NextNode.Root);
// Create a new random access list.
result = new RandomAccessList(
new RalTopNode(newRoot, first.NextNode.NextNode),
Count + 1);
}
return result;
}
