Method enter

crates/vm/src/recursion.rs:12–23

Returns None if the guard against 'obj' is still held otherwise returns the guard. The guard which is released if dropped.

(vm: &'vm VirtualMachine, obj: &PyObject)

    /// Returns None if the guard against 'obj' is still held otherwise returns the guard. The guard
    /// which is released if dropped.
    pub fn enter(vm: &'vm VirtualMachine, obj: &PyObject) -> Option<Self> {
        let mut guards = vm.repr_guards.borrow_mut();

        // Should this be a flag on the obj itself? putting it in a global variable for now until it
        // decided the form of PyObject. https://github.com/RustPython/RustPython/issues/371
        let id = obj.get_id();
        if guards.contains(&id) {
            return None;
        }
        guards.insert(id);
        Some(ReprGuard { vm, id })
    }
}

impl Drop for ReprGuard<'_> {