Trait Tracer 

pub trait Tracer {
    // Required methods
    fn trace_instruction(&mut self, ip: u16, instr: &Instruction<'_>);
    fn trace_nav(&mut self, nav: Nav, node: Node<'_>);
    fn trace_nav_failure(&mut self, nav: Nav);
    fn trace_match_success(&mut self, node: Node<'_>);
    fn trace_match_failure(&mut self, node: Node<'_>);
    fn trace_field_success(&mut self, field_id: NonZero<u16>);
    fn trace_field_failure(&mut self, node: Node<'_>);
    fn trace_effect(&mut self, effect: &RuntimeEffect<'_>);
    fn trace_effect_suppressed(&mut self, opcode: EffectOpcode, payload: usize);
    fn trace_suppress_control(&mut self, opcode: EffectOpcode, suppressed: bool);
    fn trace_call(&mut self, target_ip: u16);
    fn trace_return(&mut self);
    fn trace_checkpoint_created(&mut self, ip: u16);
    fn trace_backtrack(&mut self);
    fn trace_enter_entrypoint(&mut self, target_ip: u16);
    fn trace_enter_preamble(&mut self);
}

Tracer trait for VM execution instrumentation.

All methods receive raw data (IDs, nodes) that the VM already has. Formatting and name resolution happen in the tracer implementation.

Each method is called at a specific point during execution:

• trace_instruction - before executing an instruction
• trace_nav - after navigation succeeds
• trace_match_success/failure - after type check
• trace_field_success/failure - after field check
• trace_effect - after emitting an effect
• trace_call - when entering a definition
• trace_return - when returning from a definition
• trace_checkpoint_created - when a checkpoint is pushed
• trace_backtrack - when restoring a checkpoint
• trace_enter_entrypoint - when entering an entrypoint (for labels)

Required Methods

fn trace_instruction(&mut self, ip: u16, instr: &Instruction<'_>)

Called before executing an instruction.

fn trace_nav(&mut self, nav: Nav, node: Node<'_>)

Called after navigation succeeds.

fn trace_nav_failure(&mut self, nav: Nav)

Called when navigation fails (no child/sibling exists).

fn trace_match_success(&mut self, node: Node<'_>)

Called after type check succeeds.

fn trace_match_failure(&mut self, node: Node<'_>)

Called after type check fails.

fn trace_field_success(&mut self, field_id: NonZero<u16>)

Called after field check succeeds.

fn trace_field_failure(&mut self, node: Node<'_>)

Called after field check fails.

fn trace_effect(&mut self, effect: &RuntimeEffect<'_>)

Called after emitting an effect.

fn trace_effect_suppressed(&mut self, opcode: EffectOpcode, payload: usize)

Called when an effect is suppressed (inside @_ capture).

fn trace_suppress_control(&mut self, opcode: EffectOpcode, suppressed: bool)

Called for SuppressBegin/SuppressEnd control effects. suppressed is true if already inside another suppress scope.

fn trace_call(&mut self, target_ip: u16)

Called when entering a definition via Call.

fn trace_return(&mut self)

Called when returning from a definition.

fn trace_checkpoint_created(&mut self, ip: u16)

Called when a checkpoint is created.

fn trace_backtrack(&mut self)

Called when backtracking occurs.

fn trace_enter_entrypoint(&mut self, target_ip: u16)

Called when entering an entrypoint (for section labels).

fn trace_enter_preamble(&mut self)

Called when entering the preamble (bootstrap wrapper).

Implementors

impl Tracer for PrintTracer<'_>