|Portability||portable (depends on GHC)|
A persistent index into a tree model.
RowReference is an index into a
TreeModel that is persistent even if
rows are inserted, deleted or reordered.
Tree Row Reference : like a
TreePath it points to a subtree or node, but
it is persistent. It identifies the same node (so long as it exists) even
when items are added, removed, or reordered.
Creates a row reference based on a path. This reference will keep pointing
to the node pointed to by the given path, so long as it exists. Returns
Nothing if there is no node at the given path.
Returns a path that the row reference currently points to.
- The returned path may be the empty list if the reference was invalid.