Navigate from a node to its previous sibling N times to reach the Nth sibling left of the focus, or throw an exception if the focus index is less than N.
When n is zero, the zipper is returned unchanged.
n
Will throw an exception on negative indexes.
Unsafe version of tryPreviousN.
The underlying type of the tree.
The zipper that will be navigated.
Number of siblings to skip to the left.
An updated zipper pointing at a new focus.
Navigate from a node to its previous sibling N times to reach the Nth sibling left of the focus, or throw an exception if the focus index is less than N.
When
nis zero, the zipper is returned unchanged.Will throw an exception on negative indexes.
Unsafe version of tryPreviousN.
Type Param: A
The underlying type of the tree.
Param: self
The zipper that will be navigated.
Param: n
Number of siblings to skip to the left.
Returns
An updated zipper pointing at a new focus.