双方向再帰層

public typealias Input = [Cell.TimeStepInput]

public typealias Output = [Cell.TimeStepOutput]

public typealias MergeFunction = @differentiable (Cell.TimeStepOutput, Cell.TimeStepOutput) -> Cell.TimeStepOutput

public var forward: RecurrentLayer<Cell>

public var backward: RecurrentLayer<Cell>

@noDerivative
public var mergeFunction: MergeFunction { get }

public init(_ cell: @autoclosure () -> Cell, mergeFunction: @escaping MergeFunction = concatenate)

@differentiable
public func callAsFunction(
  _ inputs: Input,
  initialForwardLayerState: Cell.State,
  initialBackwardLayerState: Cell.State
) -> Output

@differentiable
public func callAsFunction(_ inputs: Input) -> Output

@differentiable
public func lastOutput(
  from inputs: Input,
  initialForwardLayerState: Cell.State,
  initialBackwardLayerState: Cell.State
) -> Cell.TimeStepOutput

@differentiable
public func lastOutput(from inputs: Input) -> Cell.TimeStepOutput