subscribe_last for RxLua.Observable

rx-subscribe_last.lua

local rx = require("rx")
rx.Observable.subscribe_last = function(self, callback)
  local original_onNext = self.onNext
  self.onNext = function(self, ...)
    original_onNext(self, ...)
    callback(...)
  end
  return rx.Subscription.create(function()
    self.onNext = original_onNext
  end)
end

rx-subscribe_last.moon

rx  = require "rx"

rx.Observable.subscribe_last = (callback) =>
  original_onNext = @onNext
  @onNext = (...) =>
    original_onNext @, ...
    callback ...
  rx.Subscription.create ->
    -- undo
    @onNext = original_onNext