Extractors Reference

Extractors auto-generate TLX spec skeletons from existing code. Each extractor targets a specific module type and produces a result map that feeds into OTP patterns or TLX.Importer.Codegen.

Extraction Tiers (ADR-0012)

Confidence Levels

Extractors annotate each transition with a confidence level:

When all transitions are :high confidence, the mix task generates a pattern module. Otherwise it falls back to codegen (defspec) format.

Extractor Output Formats

State machine extractors

gen_statem, Erlang gen_fsm, Ash.StateMachine produce:

%{
  behavior: :gen_statem | :gen_fsm | :ash_state_machine,
  states: [:idle, :running, ...],
  initial: :idle,
  transitions: [
    %{event: :start, from: :idle, to: :running, guard: nil, confidence: :high}
  ],
  warnings: []
}

Multi-field extractors

GenServer, LiveView produce:

%{
  behavior: :gen_server | :live_view,
  fields: [status: :idle, count: 0],
  calls: [%{name: :check, next: [status: :in_sync], guard: [], confidence: :high}],
  casts: [...],
  infos: [...],
  warnings: []
}

LiveView uses events (from handle_event/3) instead of calls.

Workflow extractors

Reactor produces:

%{
  behavior: :reactor,
  inputs: [:url],
  steps: [%{name: :fetch, depends_on: [{:input, :url}], async: true, max_retries: :infinity}],
  return: :fetch,
  graph: %{fetch: []},
  warnings: []
}

Broadway produces:

%{
  behavior: :broadway,
  producers: [%{module: Broadway.DummyProducer, concurrency: 1, rate_limiting: false}],
  processors: [%{name: :default, concurrency: 2}],
  batchers: [%{name: :sqs, concurrency: 1, batch_size: 10, batch_timeout: 1000}],
  callbacks: %{handle_message: 1, handle_batch: 2},
  warnings: []
}

Limitations