Struct NullWireSource 

pub struct NullWireSource;

Empty WireSource — every get returns None, names is empty. Used as the default for ExecCtx::new so callers that don’t yet have a kernel handle don’t need to construct a real implementation. Migration call sites switch to ExecCtx::with_wires when they own a kernel reference (see SRD-68 Push 2 and beyond).

Trait Implementations

impl WireSource for NullWireSource

fn get(&self, _name: &str) -> Option<Value>

Look up name in this kernel’s scope. Returns the current value (cloned, owned) or None when the name is not declared here. Callers do not retry against another kernel — a None is the resolution result, full stop.

fn names(&self) -> Box<dyn Iterator<Item = String> + '_>

Iterate declared names. Order is implementation-defined. Used by validators and diagnostic renderers.

fn write(&self, _name: &str, _value: Value) -> WriteOutcome

Write value into the named input slot of this kernel. Returns WriteOutcome::Stored when the slot exists and the value was written, WriteOutcome::NoSlot when the kernel’s program has no input slot named name.

fn reset(&self, _name: &str) -> WriteOutcome

Reset the named input slot to its DECLARED initial value — the author’s identity element for that wire. The capture layer uses this for min/max-of-nothing (SRD-93-era fold totality): an empty measurement restores the wire to its declared unit rather than parking Value::None on a typed slot, where every downstream consumer would have to be None-aware. Default impl returns NoSlot (read-only sources have nothing to reset).

fn advance(&self, _coord: u64)

Advance the underlying kernel state to coordinate coord and invalidate any memoized pulls so subsequent get calls produce values for this coord.