Yeah but actually it’s really a keyword artefact in that case. It’s more surprising that with all the emphases in the doc about readability, it will stick to an identifier like "arrow", when "which", "that" or "through" would make it far approachable. At least I would guess so.

  -- what we don’t care to use later, we brush under the mat/rug [2,3]
  local mat = 5
      -- nub, as the essence or core of an issue, argument etc. [1]
      % through(function(nub) return -nub end)
      ^ through(function(nub) return nub + 10 end)
      ^ through(function(nub) return nub * nub end)
      ^ through(print)  -- 25

[2] https://dictionary.cambridge.org/dictionary/english/sweep-un...

[3] https://idioms.thefreedictionary.com/brush+(something)+under...