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 external length : string -> int = "%string_length" external get : string -> int -> char = "%string_safe_get" external set : bytes -> int -> char -> unit = "%string_safe_set" external create : int -> bytes = "caml_create_string" val make : int -> char -> string val init : int -> f:(int -> char) -> string val copy : string -> string val sub : string -> pos:int -> len:int -> string val fill : bytes -> pos:int -> len:int -> char -> unit val blit : src:string -> src_pos:int -> dst:bytes -> dst_pos:int -> len:int -> unit val concat : sep:string -> string list -> string val iter : f:(char -> unit) -> string -> unit val iteri : f:(int -> char -> unit) -> string -> unit val map : f:(char -> char) -> string -> string val mapi : f:(int -> char -> char) -> string -> string val trim : string -> string val escaped : string -> string val index : string -> char -> int val rindex : string -> char -> int val index_from : string -> int -> char -> int val rindex_from : string -> int -> char -> int val contains : string -> char -> bool val contains_from : string -> int -> char -> bool val rcontains_from : string -> int -> char -> bool val uppercase : string -> string val lowercase : string -> string val capitalize : string -> string val uncapitalize : string -> string type t = string val compare : StringLabels.t -> StringLabels.t -> int external unsafe_get : string -> int -> char = "%string_unsafe_get" external unsafe_set : bytes -> int -> char -> unit = "%string_unsafe_set" external unsafe_blit : src:string -> src_pos:int -> dst:bytes -> dst_pos:int -> len:int -> unit = "caml_blit_string" "noalloc" external unsafe_fill : bytes -> pos:int -> len:int -> char -> unit = "caml_fill_string" "noalloc" end