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 val zero : int64 val one : int64 val minus_one : int64 external neg : int64 -> int64 = "%int64_neg" external add : int64 -> int64 -> int64 = "%int64_add" external sub : int64 -> int64 -> int64 = "%int64_sub" external mul : int64 -> int64 -> int64 = "%int64_mul" external div : int64 -> int64 -> int64 = "%int64_div" external rem : int64 -> int64 -> int64 = "%int64_mod" val succ : int64 -> int64 val pred : int64 -> int64 val abs : int64 -> int64 val max_int : int64 val min_int : int64 external logand : int64 -> int64 -> int64 = "%int64_and" external logor : int64 -> int64 -> int64 = "%int64_or" external logxor : int64 -> int64 -> int64 = "%int64_xor" val lognot : int64 -> int64 external shift_left : int64 -> int -> int64 = "%int64_lsl" external shift_right : int64 -> int -> int64 = "%int64_asr" external shift_right_logical : int64 -> int -> int64 = "%int64_lsr" external of_int : int -> int64 = "%int64_of_int" external to_int : int64 -> int = "%int64_to_int" external of_float : float -> int64 = "caml_int64_of_float" external to_float : int64 -> float = "caml_int64_to_float" external of_int32 : int32 -> int64 = "%int64_of_int32" external to_int32 : int64 -> int32 = "%int64_to_int32" external of_nativeint : nativeint -> int64 = "%int64_of_nativeint" external to_nativeint : int64 -> nativeint = "%int64_to_nativeint" external of_string : string -> int64 = "caml_int64_of_string" val to_string : int64 -> string external bits_of_float : float -> int64 = "caml_int64_bits_of_float" external float_of_bits : int64 -> float = "caml_int64_float_of_bits" type t = int64 val compare : Int64.t -> Int64.t -> int external format : string -> int64 -> string = "caml_int64_format" end