/// Removes the edge with the given index.  The edges are counted according
/// to the in-order traversal of the tree.
Removes the edge with the given index.  The edges are counted according
to the in-order traversal of the tree.
Removes the edge with the given index . The edges are counted according to the in - order traversal of the tree .
fn remove_edge_at_index(t: &mut RoseHashTree, idx: usize) -> Option<(Path, RoseHashTree)> {
        fn go_rec(
            t: &mut RoseHashTree,
            idx: usize,
            path: &mut Path,
        ) -> Result<(Path, RoseHashTree), usize> {
            match t {
                RoseHashTree::Leaf(_) => Err(idx),
                RoseHashTree::Fork { children, .. } => {
                    let mut i = idx;
                    let mut removed_child = None;
                    for (label, mut child) in children.iter_mut() {
                        if i == 0 {
                            removed_child = Some(label.clone());
                            break;
                        }
                        i -= 1;
                        path.push(label.clone());
                        match go_rec(&mut child, i, path) {
                            Ok(result) => return Ok(result),
                            Err(new_index) => i = new_index,
                        }
                        path.pop();
                    }
                    match removed_child {
                        Some(label) => {
                            let t = children.remove(&label).unwrap();
                            path.push(label);
                            Ok((path.clone(), t))
                        }
                        None => Err(i),
                    }
                }
            }
        }
        let mut path = Path::new(vec![]);
        match go_rec(t, idx, &mut path) {
            Ok(result) => {
                rehash(t);
                Some(result)
            }
            Err(_) => None,
        }
    }
fn remove_edge_at_index ( t : & mut RoseHashTree , idx : usize ) -> Option < ( Path , RoseHashTree ) > { fn go_rec ( t : & mut RoseHashTree , idx : usize , path : & mut Path , ) -> Result < ( Path , RoseHashTree ) , usize > { match t { RoseHashTree :: Leaf ( _ ) => Err ( idx ) , RoseHashTree :: Fork { children , .. } => { let mut i = idx ; let mut removed_child = None ; for ( label , mut child ) in children . iter_mut ( ) { if i == 0 { removed_child = Some ( label . clone ( ) ) ; break ; } i -= 1 ; path . push ( label . clone ( ) ) ; match go_rec ( & mut child , i , path ) { Ok ( result ) => return Ok ( result ) , Err ( new_index ) => i = new_index , } path . pop ( ) ; } match removed_child { Some ( label ) => { let t = children . remove ( & label ) . unwrap ( ) ; path . push ( label ) ; Ok ( ( path . clone ( ) , t ) ) } None => Err ( i ) , } } } } let mut path = Path :: new ( vec ! [ ] ) ; match go_rec ( t , idx , & mut path ) { Ok ( result ) => { rehash ( t ) ; Some ( result ) } Err ( _ ) => None , } }
Removes the edge with the given index.
Removes the edge with the given index .
t
&mut RoseHashTree
idx
usize