Struct StateAdd 

pub struct StateAdd;

Additive state cell for forward references (Using before Tag).

On the first forward call, the graph auto-zeros the state, so stream + zeros = stream (pass-through). On subsequent calls, the accumulated state is added to the current stream.

FlowBuilder::from(embed)
    .through(StateAdd)
    .using(&["memory"])
    .tag("memory")
    .build()

Trait Implementations

impl Module for StateAdd

fn name(&self) -> &str

Human-readable type name used as node ID prefix in graph visualization. Override to return a lowercase identifier (e.g., “linear”, “gelu”).

fn forward(&self, input: &Variable) -> Result<Variable>

Run the forward pass on input and return the result.

fn as_named_input(&self) -> Option<&dyn NamedInputModule>

Upcast to NamedInputModule for multi-input graphs. Override in types that implement NamedInputModule to enable receiving additional named inputs via graph using().

fn parameters(&self) -> Vec<Parameter>

Return this module’s learnable parameters. Default: recursively collects from sub_modules() with pointer dedup. Leaf modules should override to return their own parameters.

fn buffers(&self) -> Vec<Buffer>

Return this module’s non-learnable persistent buffers (e.g., running stats). Default: recursively collects from sub_modules() with pointer dedup. Leaf modules should override to return their own buffers.

fn sub_modules(&self) -> Vec<Rc<dyn Module>>

Return direct child modules for recursive tree walks. Override in composite modules (loops, switches, gates).

fn move_to_device(&self, _device: Device)

Move all parameters and buffers to the given device. Override in modules like BatchNorm that hold non-parameter state.

fn set_training(&self, _training: bool)

Set training/eval mode. Affects Dropout, BatchNorm, etc. Override in modules with mode-dependent behavior.

fn train(&self)

Set training mode. Shorthand for set_training(true).

fn eval(&self)

Set eval mode. Shorthand for set_training(false).

fn trace(&self) -> Option<Variable>

Return per-iteration side output for loop tracing. Override in loop body modules that capture trajectory data (e.g., attention fixation points). Returns None by default. When Some, the loop executor collects traces accessible via Graph::traces().

fn as_loop_body(&self) -> Option<&dyn LoopBody>

Upcast to LoopBody for loop bodies that publish named per-iteration traces. Override in types that implement LoopBody to enable multi-output trace publishing via TraceEmit::publish. Default returns None, in which case the loop runner falls back to the legacy Module::trace path.

fn as_graph(&self) -> Option<&Graph>

Upcast to Graph for hierarchical tree composition. Override in Graph to enable subgraph nesting with label-path addressing.

fn structural_hash(&self) -> Option<String>

SHA-256 hex hash of module architecture for checkpoint validation. Override in composite modules (Graph) that compute a deterministic hash from their topology and parameter shapes.

fn reset(&self)

Reset internal state (e.g. recurrent hidden state) between sequences. Called by loops before iterating to clear stale tensors whose grad_fns may reference freed saved tensors. Override in stateful modules.

fn detach_state(&self)

Detach internal state from the computation graph (for truncated BPTT). Called between training steps to break gradient chains on state carried across forward passes (e.g., recurrent hidden state). Override in stateful modules.

impl NamedInputModule for StateAdd

fn forward_named( &self, input: &Variable, refs: &HashMap<String, Variable>, ) -> Result<Variable>

Forward pass with additional named inputs from tagged graph nodes. refs maps tag names to their current values, as wired by FlowBuilder::using().