private void LengthChangedHandler(Rope sender, int newLength)
{
if (Object.Equals(sender, Left))
{
LeftLengthCache = newLength;
}
if (Object.Equals(sender, Right))
{
RightLengthCache = newLength;
}
LengthChangedAction?.Invoke(this, LeftLengthCache + RightLengthCache);
}
public Rope Remove(int start, int length)
{
if (IsLeaf)
{
if (Leaf.Length < start)
{
throw new ArgumentOutOfRangeException("Start is after the length of this string. Cant remove");
}
if (start + length < Leaf.Length)
{
//need to split the leaf into left and right
var newRight = new Rope {
Leaf = new LeafSection(Leaf.Base, Leaf.Start + start + length, Leaf.Length - (start + length)), LengthChangedAction = LengthChangedHandler
};
var newLeft = new Rope {
Leaf = new LeafSection(Leaf.Base, Leaf.Start, start), LengthChangedAction = LengthChangedHandler
};
this.Right = newRight;
this.Left = newLeft;
}
else if (start == 0)
{
//need to remove the begining
Leaf.Start += length;
Leaf.Length -= length;
}
else
{
//need to remove the end
Leaf.Length = start;
}
LengthChangedAction?.Invoke(this, Length);
}
else
{
var leftLen = LeftLength();
if (start < leftLen)
{
var lenInLeft = Math.Min(leftLen - start, length);
Left.Remove(start, lenInLeft);
if (lenInLeft < length)
{
Right.Remove(0, length - lenInLeft);
}
}
else
{
Right.Remove(start - leftLen, length);
}
if (Right?.Length == 0)
{
Right = null;
}
if (Left?.Length == 0)
{
//if left is empty then move right to left
if (Right == null)
{
Left = null;
}
else
{
Left = Right; Right = null;
}
}
}
return(this);
}
