use tree_sitter::{Node, TreeCursor};
pub struct BoundedCursor<'tree> {
cursor: TreeCursor<'tree>,
bounds: Vec<Node<'tree>>,
exhausted: bool,
}
impl<'tree> BoundedCursor<'tree> {
pub fn new(node: Node<'tree>) -> Self {
Self {
cursor: node.walk(),
bounds: Vec::new(),
exhausted: false,
}
}
pub fn current_node(&self) -> Option<Node<'tree>> {
if self.exhausted {
None
} else {
Some(self.cursor.node())
}
}
pub fn push(&mut self) {
assert!(!self.exhausted);
self.bounds.push(self.cursor.node());
}
pub fn pop(&mut self) -> bool {
let bound = self.bounds.pop().unwrap();
while self.cursor.node() != bound {
assert!(self.cursor.goto_parent());
}
self.skip()
}
pub fn goto_next_node(&mut self) -> bool {
if self.cursor.goto_first_child() {
return true;
}
self.skip()
}
pub fn skip(&mut self) -> bool {
loop {
if self.cursor.goto_next_sibling() {
self.exhausted = false;
return true;
}
if !self.cursor.goto_parent() {
assert!(self.bounds.is_empty(), "{:#?}", self.bounds);
self.exhausted = true;
return false;
}
if self.at_current_bound() {
self.exhausted = true;
return false;
}
}
}
fn at_current_bound(&self) -> bool {
self.bounds
.last()
.is_some_and(|&bound| bound == self.cursor.node())
}
}