= MLtonArray

[source,sml]
----
signature MLTON_ARRAY =
   sig
      val unfoldi: int * 'b * (int * 'b -> 'a * 'b) -> 'a array * 'b
   end
----

* `unfoldi (n, b, f)`
+
constructs an array _a_ of length `n`, whose elements _a~i~_ are
determined by the equations __b~0~ = b__ and
__(a~i~, b~i+1~) = f (i, b~i~)__.
