Function exception_group_projection

crates/vm/src/exceptions.rs:2939–2956

Project orig onto keep list, preserving nested structure. Returns an exception group containing only the exceptions from orig that are also in the keep list.

(
    orig: &PyObjectRef,
    keep: &[PyObjectRef],
    vm: &VirtualMachine,
)

/// Returns an exception group containing only the exceptions from orig
/// that are also in the keep list.
fn exception_group_projection(
    orig: &PyObjectRef,
    keep: &[PyObjectRef],
    vm: &VirtualMachine,
) -> PyResult {
    if keep.is_empty() {
        return Ok(vm.ctx.none());
    }

    // Collect all leaf IDs from keep list
    let mut leaf_ids = HashSet::new();
    for e in keep {
        collect_exception_group_leaf_ids(e, &mut leaf_ids, vm);
    }

    // Split orig by matching leaf IDs, preserving structure
    split_by_leaf_ids(orig, &leaf_ids, vm)
}

/// Recursively split an exception (group) by leaf IDs.
/// Returns the projection containing only matching leaves with preserved structure.