Struct FrameMarker 

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

A 64-bit packed activation record marker that lives in the value stack slot base-1 of any Lua frame (LJ_FR2 model). Carries the frame kind (lower 3 bits) + PC-or-delta payload (upper 61 bits).

Construction goes through FrameMarker::new_lua / FrameMarker::new_cont which encode their args correctly; destruction goes through FrameMarker::kind / FrameMarker::payload.

Internally a u64 so it round-trips through Value::Int(i64) safely without losing bits — luna’s Value::Int is a full i64 (no NaN boxing), so the bit pattern survives the stack store/load cleanly.

Implementations

impl FrameMarker

pub fn new_lua(pc: u32) -> Self

Build a FrameKind::Lua marker with the given PC. PC must fit in 61 bits (a u32 always does). Panics in debug mode on overflow; production code is expected to pass a u32.

pub fn new_cont(delta: u32) -> Self

Build a FrameKind::Cont marker with the given frame delta (slots between this frame’s base and the previous frame’s base). Delta must fit in 61 bits.

pub fn kind(self) -> Option<FrameKind>

Read the frame kind (lower 3 bits).

pub fn payload(self) -> u32

Read the PC/delta payload (upper 61 bits, shifted down). For Lua frames this is the bytecode PC; for Cont frames the caller-base delta.

pub fn to_raw(self) -> i64

Raw bits, suitable for storing in a Value::Int(i64) slot. The reverse direction is FrameMarker::from_raw.

pub fn from_raw(raw: i64) -> Self

Reconstruct a FrameMarker from raw bits read out of a value stack slot. The caller is responsible for ensuring the slot actually held a marker (otherwise the kind decode may fail).

Trait Implementations

impl Clone for FrameMarker

fn clone(&self) -> FrameMarker

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FrameMarker

impl Debug for FrameMarker

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

Formats the value using the given formatter.

impl Eq for FrameMarker

impl PartialEq for FrameMarker

fn eq(&self, other: &FrameMarker) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for FrameMarker