insertRight method
Insert new node to the right
Implementation
ZipperLocation<ZR, ZI, ZS> insertRight(ZR r) {
if (path is TopPath) {
throw Exception("insert of top");
}
final p = path as NodePath<ZS, ZR>;
return update(
node: node,
path: NodePath(
left: p.left,
parentPath: p.parentPath,
parentNode: p.parentNode,
right: List.unmodifiable([r, ...p.right]),
),
);
}