There is indeed something tricky going on: Elm uses persistent data structures behind the scenes. See this previous HN discussion about Elm's persistent data s

There is indeed something tricky going on: Elm uses persistent data structures behind the scenes. See this previous HN discussion about Elm's persistent data structures: https://news.ycombinator.com/item?id=7686272 https://news.ycombinator.com/item?id=7686272