  This paper proposes a message-passing mechanism to address language
modelling. A new layer type is introduced that aims to substitute
self-attention for unidirectional sequence generation tasks. The system is
shown to be competitive with existing methods: Given N tokens, the
computational complexity is O(N logN) and the memory complexity is O(N) under
reasonable assumptions. In the end, the Dispatcher layer is seen to achieve
comparable perplexity to prior results while being more efficient.
