Struct DatasetOpen 

pub struct DatasetOpen { /* private fields */ }

dataset_open(source: str, facet: str) -> Handle

The single resolver node. Provenance follows its two wire inputs; when both are scope-extern constants (the iter-var case), this evaluates exactly once at iteration entry and stays cached for every cycle in that iteration. When source or facet is cycle-time, it re-evaluates accordingly.

All per-cycle accessors take the resulting handle on a wire — the catalog/HTTP/mmap path is never on the cycle hot path.

Resolve failures used to fall through silently as Value::None so a downstream op wrapper could lift them. That pattern also let comprehension clause evaluation degrade silently (catalog miss → None → downstream handle_of panic → caught + swallowed → literal-list fallback splits the spec on a comma → garbage iter-var). We now panic with the underlying error: the engine’s enrich_eval_panic adds node provenance, eval_const_expr traps the panic into Result::Err, and evaluate_spec propagates it as a clean clause-level diagnostic.

Implementations

impl DatasetOpen

pub fn new() -> Self

A dataset_open node with the given constant arguments.

Trait Implementations

impl Default for DatasetOpen

fn default() -> Self

Returns the “default value” for a type.

impl PolydatNode for DatasetOpen

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 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 SRD-74 Rule 1 (None in → None out, no eval invocation).

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

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

fn compiled_slot(&self, _wire_types: &[PortType]) -> 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 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 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 (SRD-105 cone extraction). 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.