Struct Graph 

pub struct Graph {
    pub nodes: Vec<GraphNode>,
    pub names: BTreeMap<usize, String>,
}

The traced computational graph: a list of GraphNodes plus optional node names.

Fields

nodes: Vec<GraphNode>

The graph’s nodes, in the order they were recorded.

names: BTreeMap<usize, String>

Node index → dotted name captured from [crate::name_scope] at recording time.

Implementations

impl Graph

pub fn new() -> Self

Creates an empty graph.

pub fn add_node( &mut self, op: Op, inputs: Vec<usize>, dtype: DtypeRepr, shape: Shape, ) -> usize

Appends a new node to the graph, returning its index.

pub fn topological_sort(&self) -> Vec<usize>

Returns node indices in topological order (producers before consumers) using Kahn’s algorithm. Panics if the graph contains a cycle.

pub fn optimise(&self) -> Graph

Rewrite the graph by fusing compatible op sequences into single fused ops.

Currently recognises: Conv2d(no bias) → BatchNorm2d → Silu and replaces the triple with a single Conv2dBnSilu node.

Nodes that are absorbed into a fused node are removed from the output graph; remaining node indices are renumbered contiguously.

This does not include Graph::fuse_elementwise_chains — that pass produces Op::Fused nodes, and folding it in here would silently change what every existing optimise() caller lowers to. Call it separately once the target lowering backend actually knows how to compile Op::Fused.

pub fn fuse_elementwise_chains(&self) -> Graph

Rewrite the graph by fusing adjacent, single-input/single-output elementwise chains (see is_fusable_elementwise) into Op::Fused nodes.

Separate from Graph::optimise on purpose: producing Op::Fused only helps once a lowering backend knows how to compile it (concatenate each member’s kernel source and synthesize an entry point that runs them in sequence — see the Op::Fused doc comment). Call this explicitly once that backend support exists; don’t fold it into optimise(), which every existing caller already depends on producing today’s set of ops.

Iterates Graph::fuse_elementwise_chain_pass to a fixed point: each call only merges one adjacent pair, so a chain longer than two nodes grows by one member per iteration until nothing more merges.

Trait Implementations

impl Clone for Graph

fn clone(&self) -> Graph

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Graph

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Graph

fn default() -> Graph

Returns the “default value” for a type.