utils.py 文件源码

def _step(time, sequence_length, min_sequence_length, max_sequence_length, zero_logit, generate_logit):
  # Step 1: determine whether we need to call_cell or not
  empty_update = lambda: zero_logit
  logit = control_flow_ops.cond(
    time < max_sequence_length, generate_logit, empty_update)

  # Step 2: determine whether we need to copy through state and/or outputs
  existing_logit = lambda: logit

  def copy_through():
    # Use broadcasting select to determine which values should get
    # the previous state & zero output, and which values should get
    # a calculated state & output.
    copy_cond = (time >= sequence_length)
    return math_ops.select(copy_cond, zero_logit, logit)

  logit = control_flow_ops.cond(
    time < min_sequence_length, existing_logit, copy_through)
  logit.set_shape(logit.get_shape())
  return logit