Runtime & Layout¶

Rezi's runtime turns state into frames through a deterministic pipeline. This page is an index for the runtime internals and the layout model used across widgets.

Runtime pipeline¶

flowchart LR
  State["State"] --> View["view(state)"]
  View --> VNode["VNode Tree"]
  VNode --> Reconcile
  Reconcile --> Layout
  Layout --> Drawlist["ZRDL Drawlist"]
  Drawlist --> Backend["Backend Submit"]
  Backend --> Events["ZREV Event Batch"]
  Events --> Update["update()"]
  Update --> State

Runtime phases¶

Reconciliation: compares the new VNode tree to the previous one and computes changes.
Layout: resolves sizes and positions in terminal cell units.
Rendering: builds ZRDL drawlists and submits them to the backend.
Event dispatch: parses ZREV batches and routes input to widgets or global handlers.

Layout model¶

Layout is cell-based and deterministic. Stacks (row, column) and constraints (width, height, flex) are the core primitives.

Layout guide

Input & focus¶

Focus routing and key handling are part of the runtime contract.

Update contract¶

Update batching, commit points, and runtime error codes are defined in the lifecycle guide.

Lifecycle & updates

Protocol boundary¶

The runtime talks to the engine over ZRDL and ZREV.