Brr_ocaml_poke_ui.HistoryPrompt history data structure.
v ~prev initializes the toplevel with previous entries prev (later elements are older).
val empty : tempty is an empty history.
prev h current makes current the next entry of the resulting history and returns the previous entry of h (if any).
next h current makes current the previous entry of the resulting history and returns the next entry of h (if any).
to_string ~sep t is a string with the entries of t separated by lines that contain sep.