# `Monty.Simulators.Recording.SensorModule`
[🔗](https://github.com/d-led/ex.tbp.monty/blob/v0.1.0/packages/ex_tbp_monty_core/lib/monty/simulators/recording/sensor_module.ex#L1)

A sensor that replays a recording instead of sensing.

A recorded episode is a sequence of percepts, one per step the real sensor had
something to say — already in the cortical messaging protocol, because they
were taken from Monty's own module input. There is nothing to sense and
nothing to extract: this hands them back in order, one per step, and the
runtime cannot tell the difference between it and a sensor looking at a world.

It is a simulator-side module, like `Monty.Simulators.Synthetic.SensorModule`,
so it is not part of the module map. What it is for is the one comparison a
simulator cannot make: whether the *runtime*, not just the learning module,
reproduces an episode Monty ran.

A recording has more steps than it has percepts — the sensor is silent while
the agent moves — so the queue holds a `nil` for every silent step, and
`reset/1` rewinds to the beginning, which is how an episode can be replayed.

# `state`

```elixir
@type state() :: %{
  sensor_module_id: atom() | String.t(),
  recorded: [Monty.Cmp.Message.t() | nil],
  percepts: [Monty.Cmp.Message.t() | nil]
}
```

# `new`

```elixir
@spec new(atom() | String.t(), [Monty.Cmp.Message.t() | nil]) :: state()
```

A sensor that says what `percepts` says, in order, one step at a time.

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*Consult [api-reference.md](api-reference.md) for complete listing*