# `Statifier.Invoke.Types`
[🔗](https://github.com/riddler/statifier-ex/blob/v2.0.0/lib/statifier/invoke/types.ex#L1)

A caller-declared, point-in-time claim about which `<invoke type>` values
this deployment implements beyond the built-in `scxml` handler (ADR-0051
decision 2) - a plain value in `Statifier.Invoke`'s namespace, mirroring
`Statifier.Send.Routes`'s own shape and moduledoc posture.

This is a claim, not an observation: it is stamped once per session via
`Statifier.MachineState.new/2`'s `:invoke_types` option (not per drive -
the registered set is fixed for the session's lifetime, unlike
`Statifier.Send.Routes`) and carries no obligation to track anything
between writes.

`registered?/2` is the single shared classifier ADR-0047 decision 4 and
ADR-0051 decision 3 require: both `Statifier.Interpreter`'s
`maybe_record_active_invocation/5` and
`Statifier.Session.Effects.plan_invoke/2` answer "is this type registered"
by calling it, so the two sites cannot drift. Built-in membership -
`nil`, `"scxml"`, and the bare `http://www.w3.org/TR/scxml/` URI - keeps
delegating to `Statifier.Send.Target.supported_invoke_type?/1` rather than
being reimplemented here, so 6.4's short-form and long-URI reasoning stays
in exactly one place.

# `t`

```elixir
@type t() :: %Statifier.Invoke.Types{types: MapSet.t(String.t())}
```

# `new`

```elixir
@spec new(opts :: keyword()) :: t()
```

Builds a snapshot from `opts`: `:types` (default empty, a `MapSet` or any
`Enum` of registered `<invoke type>` strings - `MapSet.new/1` accepts
either).

# `registered?`

```elixir
@spec registered?(types :: t() | nil, type :: String.t() | nil) :: boolean()
```

Whether `type` is registered against `types`.

`types` may be `nil` - "no declaration made", the same meaning `nil`
carries on `%Statifier.MachineState{}.invoke_types` itself - in which case
this answers exactly what `Statifier.Send.Target.supported_invoke_type?/1`
answers today: `true` for `nil`, `"scxml"`, and the bare
`http://www.w3.org/TR/scxml/` URI; `false` for everything else, including
the `#SCXMLEventProcessor` URI.

A non-`nil` snapshot answers `true` for the built-in set unioned with the
declared set - declaring types adds to the built-ins, it never replaces
them.

---

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