Recipe Rollup Primer
How Meridian bundles multiple transforms into a single atomic execution unit — the recipe rollup.
What is a rollup?
A rollup is a directed acyclic graph of transforms that Meridian compiles into one fused pass. Instead of dispatching each transform individually — paying decode, dispatch, and memory round-trip costs per step — the rollup merges them into a single traversal of the payload.
Why it matters
- One allocation, one pass — zero intermediate buffers.
- Dependency edges resolve automatically; no manual wiring.
- Rollups are cacheable — same input hash, same output, zero work.
Structure
Each rollup declares its entry node, a set of interior transforms, and a terminal sink. Meridian topologically sorts the graph, fuses adjacent compatible operations, and emits a single execution plan. The plan is then handed to the runtime, which streams the payload through the fused pipeline without materializing intermediate results.
Next steps
Read the recipe authoring guide to learn how to define transforms and wire them into rollups, or jump to the execution model for details on how the fused pass actually runs.