Module Map

All library modules live under lib/ChainFollower/. The top-level ChainFollower module re-exports the public API types.

Modules

Module	Purpose
ChainFollower	Top-level re-exports: Follower, Intersector, ProgressOrRewind
ChainFollower.Backend	CPS backend interface: Restoring, Following, Init, lifting functions
ChainFollower.Runner	State machine: Phase, processBlock, rollbackTo
ChainFollower.Rollbacks.Types	Core types: Operation, inverseOf, RollbackPoint
ChainFollower.Rollbacks.Store	Transaction-level rollback operations: store, query, rollback, prune, armageddon
ChainFollower.Rollbacks.Column	RollbackColumn GADT, RollbackKV and RollbackCol type aliases
ChainFollower.MockChain	BlockTree, ChainEvent, DFS walk, canonical path extraction
ChainFollower.Laws	Testable backend laws: BackendHarness, three QuickCheck properties

Dependency Diagram

graph TD
    CF["ChainFollower"]
    B["ChainFollower.Backend"]
    R["ChainFollower.Runner"]
    RT["ChainFollower.Rollbacks.Types"]
    RS["ChainFollower.Rollbacks.Store"]
    RC["ChainFollower.Rollbacks.Column"]
    MC["ChainFollower.MockChain"]
    L["ChainFollower.Laws"]

    R --> B
    R --> RS
    R --> RC
    R --> RT
    RS --> RC
    RS --> RT
    RC --> RT
    L --> B
    L --> MC
    L --> R
    L --> RS
    L --> RT
    L --> RC

Layer Structure

The modules form three layers:

Core types -- Rollbacks.Types and Rollbacks.Column define the data model with no runtime dependencies.

Storage -- Rollbacks.Store provides cursor-based operations over the rollback column, using kv-transactions.

Orchestration -- Runner is the state machine that ties Backend and Store together. Backend defines the CPS interface that user code implements.

Testing -- MockChain and Laws sit outside the runtime path. They provide generators and testable properties for verifying backend implementations.