doc/guide/src/MLtonVector.adoc

   1 MLtonVector
   2 ===========
   3
   4 [source,sml]
   5 ----
   6 signature MLTON_VECTOR =
   7    sig
   8       val create: int -> {done: unit -> 'a vector,
   9                           sub: int -> 'a,
  10                           update: int * 'a -> unit}
  11       val unfoldi: int * 'b * (int * 'b -> 'a * 'b) -> 'a vector * 'b
  12    end
  13 ----
  14
  15 * `create n`
  16 +
  17 initiates the construction a vector _v_ of length `n`, returning
  18 functions to manipulate the vector.  The `done` function may be called
  19 to return the created vector; it is an error to call `done` before all
  20 entries have been initialized; it is an error to call `done` after
  21 having called `done`.  The `sub` function may be called to return an
  22 initialized vector entry; it is not an error to call `sub` after
  23 having called `done`.  The `update` function may be called to
  24 initialize a vector entry; it is an error to call `update` after
  25 having called `done`.  One must initialize vector entries in order
  26 from lowest to highest; that is, before calling `update (i, x)`, one
  27 must have already called `update (j, x)` for all `j` in `[0, i)`.  The
  28 `done`, `sub`, and `update` functions are all constant-time
  29 operations.
  30
  31 * `unfoldi (n, b, f)`
  32 +
  33 constructs a vector _v_ of length `n`, whose elements __v~i~__ are
  34 determined by the equations __b~0~ = b__ and
  35 __(v~i~, b~i+1~) = f (i, b~i~)__.