Hello, I apologize in case this is not the right place to bring this question/proposal up. Some time ago I stumbled upon the Selection Monad [1] (also referred to as Search from the search package on hackage). Its relation to the Continuation Monad and the usefulness demonstrated in [1] made me wonder whether it would be nice to include Selection Monad in the core libraries along the Continuation Monad (in mtl and transformers) with all the business of selections attaining continuations. I can imagine the pattern to be too little recognised to justify such an addition, yet the theoretical connection to the Continuation Monad seems to be an interesting one and worth being addressed. Best, Jakub Daniel [1] Jules Hedges. *Monad transformers for backtracking search*. In *Proceedings of MSFP 2014. *https://arxiv.org/abs/1406.2058