Translating English into useful data structures
val parse_int : string -> int
parse_int s: Like standard int_of_string, but try to convert the first twenty english numbers (eg. "one", "two", ... "twenty")

parse_int "thirteen" - : int = 13

parse_int "5296" - : int = 5296

parse_int "twenty five" Exception: (Failure int_of_string).

parse_date s: Convert a date in plain english (eg. "yesterday," "tomorrow," etc.) to a Date.t

parse_date "Yesterday" parse_date "6 8 2010" parse_date "4 days hence" parse_date "24 weekdays ago"

val parse_date : string -> Core.Std.Date.t
val parse_time : string -> Core.Std.Time.t