You could use it in code that's operating in the list monad, you just wouldn't be able to stitch the computation in using the monad interface. But you could ru

You could use it in code that's operating in the list monad, you just wouldn't be able to stitch the computation in using the monad interface. But you could run it and get a Maybe back, and look at the Maybe, and turn it into something you can stitch in. `maybe (fail "got back a Nothing") pure` is probably the most generic way, but it may or may not be what you want.