Struct AccessedSet 

pub struct AccessedSet(/* private fields */);

Tracks accessed fields and extensions with snapshot/rollback support for union parsing.

The internal state is a stack where the last item is always the current working state. Items before it are snapshots (save points) for rollback.

Invariant: stack is never empty.

Stack visualization

Initial:        [current]
push_snapshot:  [snapshot, current]  (snapshot = copy of current)
modify:         [snapshot, current'] (current' has changes)
restore:        [snapshot, snapshot] (current reset to snapshot)
pop_restore:    [snapshot]           (current removed, snapshot is new current)
pop_no_restore: [current']           (snapshot removed, keep modified current)

Implementations

impl AccessedSet

pub fn new() -> Self

Create a new empty set.

pub fn add_field(&self, field: impl Into<String>)

Add a field to the accessed set.

pub fn add_ext(&self, ext: Identifier)

Add an extension to the accessed set.

pub fn has_field(&self, field: &str) -> bool

Check if a field has been accessed.

pub fn has_ext(&self, ext: &Identifier) -> bool

Check if an extension has been accessed.

pub fn push_snapshot(&self)

Push a snapshot (call at start of union parsing). Inserts a copy of current BEFORE current, so current can be modified.

pub fn restore_to_current_snapshot(&self)

Restore current to the snapshot (call when variant fails). Resets current (last) to match the snapshot (second-to-last).

pub fn capture_current_state(&self) -> AccessedSnapshot

Capture the current state (for non-priority variants).

pub fn restore_to_state(&self, state: AccessedSnapshot)

Restore to a previously captured state.

pub fn pop_and_restore(&self)

Pop and restore (call when union fails/ambiguous). Removes current, snapshot becomes new current.

pub fn pop_without_restore(&self)

Pop without restore (call when union succeeds). Removes the snapshot, keeps current.

Trait Implementations

impl Clone for AccessedSet

fn clone(&self) -> AccessedSet

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AccessedSet

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for AccessedSet

fn default() -> Self

Returns the “default value” for a type.