Struct ControlU64 

pub struct ControlU64 {
    pub name: String,
    /* private fields */
}

Read a dynamic control’s current value and cast to u64.

Signature: control_u64(name: const str) -> u64. Resolves the control by walk-up from the session root, reads its reified-gauge f64 projection and casts to u64 (saturating at 0 for negatives). Missing / gauge-less controls return 0. For integer-valued controls (concurrency, max_retries) read as a cycle-time parameter — no need to pipe control("…") through f64_to_u64.

Authored via #[polydat::polydat_node] (SRD-80b) — purity is the hygienic attribute below. Nondeterministic because the control value changes over the run (operator edits, SRD-86 servo retargets, per-coordinate reruns): the node is never const-folded, re-evaluated on every pull, and the compiler propagates that volatility to every downstream wire, so load := control_u64("concurrency") tracks the live value without the author flagging volatile.

Fields

name: String

The name argument, as given at construction.

Implementations

impl ControlU64

pub fn new(name: String) -> Self

A control_u64 node with the given constant arguments.

Trait Implementations

impl PolydatNode for ControlU64

fn meta(&self) -> &NodeMeta

Return this node’s metadata (port names and types).

fn eval(&self, inputs: &[Value], outputs: &mut [Value])

Evaluate the node: read from inputs, write to outputs.

fn compiled_u64(&self) -> Option<CompiledU64Op>

Return a compiled u64-only evaluation closure, if this node operates entirely in u64 space.

fn jit_constants(&self) -> Vec<u64>

Return assembly-time constants for JIT compilation.

fn purity(&self) -> Purity

Declare this node’s purity status per the runtime_model.md’s D2 axiom. Default: Purity::Pure. Override to declare an observable side channel (Purity::SideChannel) or eval-call-spanning state (Purity::Nondeterministic).

fn scratch_layout(&self) -> Vec<ScratchElem>

The scratch entries a state owns for this node’s evaluation (axiom S3), one per entry in the order the node expects them in Self::eval_in. Empty for a node that evaluates over Values alone, which is every node but a native cone.

fn eval_in( &self, scratch: &mut [ScratchBuf], inputs: &[Value], outputs: &mut [Value], )

Self::eval with the node’s scratch, which the evaluating state owns and hands in: storage belongs to the state, never to the node, which is shared by every state of the program.

fn commutativity(&self) -> Commutativity

Declare which inputs are interchangeable for this node.

fn accepts_none_inputs(&self) -> bool

True iff this node should receive Value::None inputs directly rather than have the kernel propagate None through it. Default: false — most nodes follow none_semantics.md Rule 1 (None in → None out, no eval invocation).

fn compiled_slot( &self, _wire_types: &[PortType], _engine: Engine, ) -> Option<CompiledSlotKit>

Return a slot-compiled closure for nodes with typed-slice ports (§8.4 layer 3): slice inputs read (ptr, len) slot pairs; vector outputs write into kernel-owned scratch. Checked by the compiled-kernel builders AFTER Self::compiled_u64 — pure-scalar nodes never need it. Default None: the node stays on typed eval.

fn simd_variant(&self) -> Option<SimdVariant>

Explicit SIMD-native implementation of this scalar node, if one has been registered with a semantic contract.

fn fusion_subgraph(&self) -> Option<FusionSubgraph<'_>>

A synthetic fusion node’s view of the subgraph it stands in for (cone extraction, engines.md §2). Program-identity hashing (PolydatProgram::canonical_hash) walks THROUGH fusion nodes into this subgraph, so identity is invariant to the engine mix: jit=off and jit=auto compiles of the same source hash identically, and resume-skip matching survives mode changes. Default None: ordinary nodes hash as themselves.