module Readline:Interactive line editing.sig..end
   This implements very basic readline abilities: backspace, left and right
   arrows work as expected.
   There's also a history that can be browsed through the up and down arrows.
typecompleter =left:string -> right:string -> string list
module History:sig..end
val input_line : ?history:History.t ->
       ?prompt:string ->
       ?text:string -> ?tab_completion:completer -> unit -> string optionNone on EOF (i.e. the user typed ctrl + d)history : the mutable value used as a history. The deault value is
   History.default. If you don't want any history ou should use History.nullprompt : the string to use as a prompt (default value ">")tab_completion : the function use to complete on tab. By default there
   is no completion.val input_line_eof : ?history:History.t ->
       ?prompt:string ->
       ?text:string -> ?tab_completion:completer -> unit -> stringval password : ?prompt:string -> unit -> string optionNone on EOFval confirm : ?prompt:string -> string -> boolval choice : (string * 'a) list -> 'a option