structure DynamicLink =
  struct
    type lib (= boxed)
    datatype mode = LAZY | NOW
    datatype scope = GLOBAL | LOCAL
    val default : unit -> lib
    val dlclose : lib -> unit
    val dlopen  : string -> lib
    val dlopen’ : string * scope * mode -> lib
    val dlsym : lib * string -> codeptr
    val dlsym’ : lib * string -> unit ptr
    val next : unit -> lib
  end

• •

  lib An abstract type representing an internal handle of opened dynamic link library.

• •

  mode Open mode for dlopen’ primitive. NOW indicates that the library file is opened when dlopen’ is called. LAZY indicate that dlopen’ checks and only prepares to open the library file, which will be opened when some reference will be made at runtime.