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);
}
public Rope Insert(string value, int position)
{
if (this.IsLeaf)
{
if (position == 0)
{
//Insert before this
Right = new Rope {
Leaf = Leaf, LengthChangedAction = LengthChangedHandler
};
Left = new Rope(value)
{
LengthChangedAction = LengthChangedHandler
};
}
else if (position == Length)
{
//Insert after this
Left = new Rope {
Leaf = Leaf, LengthChangedAction = LengthChangedHandler
};
Right = new Rope(value)
{
LengthChangedAction = LengthChangedHandler
};
}
else
{
//its in the middle of this bit
var newLeft = new Rope();
var newLeftLen = position;
newLeft.Left = new Rope {
Leaf = new LeafSection(Leaf.Base, Leaf.Start, newLeftLen), LengthChangedAction = LengthChangedHandler
};
newLeft.Right = new Rope(value)
{
LengthChangedAction = LengthChangedHandler
};
var newRightStart = Leaf.Start + newLeftLen;
Right = new Rope {
Leaf = new LeafSection(Leaf.Base, newRightStart, Leaf.Length - newRightStart), LengthChangedAction = LengthChangedHandler
};
Left = newLeft;
}
}
else
{
var leftLen = LeftLength();
if (position < leftLen)
{
Left.Insert(value, position);
}
else
{
if (Right == null)
{
Right = new Rope(value)
{
LengthChangedAction = LengthChangedHandler
};
}
else
{
Right.Insert(value, position - leftLen);
}
}
}
return(this);
}
