@spec as_of() :: DateTime.t() | nil

Returns the active travel instant, or nil outside travel.

@spec rewrite(Ecto.Query.t()) :: Ecto.Query.t()

Rewrites live sources to temporal views while travelling, changing names only.

@spec temporal?(module()) :: boolean()

Returns whether schema was defined with temporal_schema/2.

@spec travel(Ecto.Repo.t(), DateTime.t(), (-> result), keyword()) ::
  {:ok, result} | {:error, term()}
when result: term()

Runs fun in a read-only transaction resolving temporal schemas at instant. Returns the repository transaction result.

@spec travel!(Ecto.Repo.t(), DateTime.t(), (-> result), keyword()) :: result
when result: term()

Runs travel/4 and returns the callback result.

Raises SysTime.RollbackError if the callback explicitly rolls back the read-only transaction.

@spec travelling?() :: boolean()

Returns whether the calling process is inside travel/4.