Struct PassRegistry 

pub struct PassRegistry { /* private fields */ }

A registry of Pathfinders and Optimizers, driven lock-step by Self::run_lockstep. Mirrors fuel_graph::opt::RuleRegistry: a Vec<Box<dyn …>> of passes built up with with_* builders and run through one driver method. Keeping the same shape means the future passes the constitution names (fusion, algebraic, dtype-lowering) register exactly as the two shipped passes do.

Implementations

impl PassRegistry

pub fn new() -> Self

Empty registry. Use Self::with_pathfinder / Self::with_optimizer to add passes, or Self::default_passes for the shipped configuration.

pub fn with_pathfinder(self, p: Box<dyn Pathfinder>) -> Self

Append a pathfinder. Returns self for builder-style chaining.

pub fn with_optimizer(self, o: Box<dyn Optimizer>) -> Self

Append an optimizer. Returns self for builder-style chaining.

pub fn default_passes() -> Self

The shipped Phase-B configuration: the PR-A4 PlacementForkPathfinder (the one pathfinder that records an Op::Branch per genuine multi-placement fork) and the FrontierConvergenceOptimizer (duplicate-path convergence + the per-device-frontier invariant guards). This is exactly the pre-B3 hardcoded sequence re-expressed as registered passes.

pub fn default_passes_with_runtime_fusion() -> Self

Self::default_passes plus runtime fusion: the crate::runtime_fused_pathfinder::RuntimeFusedArmPathfinder runs FIRST (before placement — placement must see the fused arms it emits; the fork seed can’t double-fork them because ctx.plan/ctx.order predate the drive and don’t contain the appended arm nodes).

A separate constructor rather than a change to default_passes so the bare registry never scans the process-global runtime-fused sidecar — non-adopting tests stay hermetic by construction, not by reset discipline (dd-shapes coordination, 2026-07-08). Transitional, like the sidecar itself: both collapse when runtime entries fold into the one binding registry (10-decisions-log, runtime-fused-sidecar entry).

pub fn pathfinder_count(&self) -> usize

Number of registered pathfinders.

pub fn optimizer_count(&self) -> usize

Number of registered optimizers.

pub fn run_lockstep( &self, graph: &mut Graph, ctx: &OptimizationContext<'_>, ) -> Result<()>

Drive the passes lock-step / prune-as-you-go: for each registered pathfinder, ADD its candidate paths, then immediately run every registered optimizer to MERGE/DISCARD over the region that pathfinder just touched, before moving to the next pathfinder.

This is the constitution’s bound: the merge/discard optimizers run after each pathfinder step, not once at the end, so the working set never explodes-then-extracts. Ordering is enforced by construction — an optimizer can only ever see the paths the pathfinders before it in this drive added.

Returns Result; the first failing pass aborts the drive (build-time validation, never a panic).

Trait Implementations

impl Default for PassRegistry

fn default() -> Self

Returns the “default value” for a type.