Module fuser 

2026-09-28: The fuser: cover a circuit’s nodes with rule groups for one mode and row count.

Greedy and deterministic. Rules are tried by priority (highest first, then id), and each rule scans the nodes in execution order; a node joins at most one group. A rule is skipped when its mode or rows do not apply, a kernel is absent, a capability is missing, a policy setting it names differs, or its differs lever is not opted in.

Owner: metrale-circuit. Invariants:

• Every node of the mode’s section ends in exactly one group, or fuse returns FuseError::Uncovered; no node is left to an implicit kernel.
• A policy must state every setting any rule reads (FuseError::PolicyMissing).
• The plan is a pure function of its inputs; FusionPlan::digest changes exactly when what the plan runs changes (see crate::digest).

Structs

AvailableKernels

2026-09-28: The kernels and capabilities a target provides (the boot probe’s answer).

FusionPlan

2026-09-28: The fused plan of one circuit for one mode and row count.

Group

2026-09-28: One launch group.

Policy

2026-09-28: What the recipe decides: opt-in levers for differs rules, and the settings (kv_cache_dtype, row_tiers, …) that when clauses read.

Enums

EdgeState

2026-09-28: Whether an edge is written to memory or stays inside one kernel.

FuseError

2026-09-28: Why no plan was produced.

Functions

fuse

2026-09-28: Fuse circuit for mode at rows padded rows. A verify_batch plan needs a row table: fuse_table.

fuse_table

2026-09-30: Fuse circuit for a batched verify of table.

group_io

2026-09-28: The edges a group reads from outside itself and the ones it writes, in edge order. Used by the renderers and the buffer planner.

section_of

2026-09-28: The section a mode runs.