Standard Library
Below is the API for the OCaml standard library. It's directly copied over from the OCaml Manual, formatted to the Reason syntax and styled accordingly. The API docs are work-in-progress; we'll be polishing these gradually!
If you're targeting JavaScript, the API docs for BuckleScript includes all of below, plus JS-specific APIs.
sig type num = Int of int | Big_int of Big_int.big_int | Ratio of Ratio.ratio val ( +/ ) : Num.num -> Num.num -> Num.num val add_num : Num.num -> Num.num -> Num.num val minus_num : Num.num -> Num.num val ( -/ ) : Num.num -> Num.num -> Num.num val sub_num : Num.num -> Num.num -> Num.num val ( */ ) : Num.num -> Num.num -> Num.num val mult_num : Num.num -> Num.num -> Num.num val square_num : Num.num -> Num.num val ( // ) : Num.num -> Num.num -> Num.num val div_num : Num.num -> Num.num -> Num.num val quo_num : Num.num -> Num.num -> Num.num val mod_num : Num.num -> Num.num -> Num.num val ( **/ ) : Num.num -> Num.num -> Num.num val power_num : Num.num -> Num.num -> Num.num val abs_num : Num.num -> Num.num val succ_num : Num.num -> Num.num val pred_num : Num.num -> Num.num val incr_num : Num.num Pervasives.ref -> unit val decr_num : Num.num Pervasives.ref -> unit val is_integer_num : Num.num -> bool val integer_num : Num.num -> Num.num val floor_num : Num.num -> Num.num val round_num : Num.num -> Num.num val ceiling_num : Num.num -> Num.num val sign_num : Num.num -> int val ( =/ ) : Num.num -> Num.num -> bool val ( </ ) : Num.num -> Num.num -> bool val ( >/ ) : Num.num -> Num.num -> bool val ( <=/ ) : Num.num -> Num.num -> bool val ( >=/ ) : Num.num -> Num.num -> bool val ( <>/ ) : Num.num -> Num.num -> bool val eq_num : Num.num -> Num.num -> bool val lt_num : Num.num -> Num.num -> bool val le_num : Num.num -> Num.num -> bool val gt_num : Num.num -> Num.num -> bool val ge_num : Num.num -> Num.num -> bool val compare_num : Num.num -> Num.num -> int val max_num : Num.num -> Num.num -> Num.num val min_num : Num.num -> Num.num -> Num.num val string_of_num : Num.num -> string val approx_num_fix : int -> Num.num -> string val approx_num_exp : int -> Num.num -> string val num_of_string : string -> Num.num val int_of_num : Num.num -> int val num_of_int : int -> Num.num val nat_of_num : Num.num -> Nat.nat val num_of_nat : Nat.nat -> Num.num val num_of_big_int : Big_int.big_int -> Num.num val big_int_of_num : Num.num -> Big_int.big_int val ratio_of_num : Num.num -> Ratio.ratio val num_of_ratio : Ratio.ratio -> Num.num val float_of_num : Num.num -> float end