The DynamicArrayFn functor

The DynamicArrayFn functor provides dynamically sized monomorphic arrays. Each array has an associated default value, which is covers those elements that have not been explicitly initialized (conceptually, one can view an array as having an infinite size). Thus, reads from indices above the bound will return the default value. The bound of an array is the highest index of an initialized element (or ~1 if there are no initialized elements). The defined range of the array are the elements in the positions indexed from zero to the bound.

Synopsis

signature MONO_DYNAMIC_ARRAY
functor DynamicArrayFn (A : MONO_ARRAY) : MONO_DYNAMIC_ARRAY

Functor Argument Interface

A : MONO_ARRAY

Functor Argument Description

A : MONO_ARRAY

A structure that implements the MONO_ARRAY signature from the SML Basis Library.

Interface

type elem
type array

val array : (int * elem) -> array

val subArray : array * int * int -> array

val fromList : elem list * elem -> array
val toList : array -> elem list

val tabulate: int * (int -> elem) * elem -> array

val default : array -> elem

val sub : array * int -> elem

val update : array * int * elem -> unit

val bound : array -> int

val truncate : array * int -> unit

Interface Description

type elem

The type of array elements.

type array

The type of dynamic arrays.

val array : (int * elem) -> array

array (sz, dflt) returns a new array with bound ~1 and default value dflt. The sz argument, which must be non-negative, is used as a hint of the potential range of indices. This function raises the Size exception if sz < 0.

val subArray : array * int * int -> array

subArray (arr, lo, hi) returns a new array with the same default as arr, and whose values in the range [0, hi-lo] are equal to the values in arr in the range [lo, hi]. This function raises the Size exception if lo > hi.

val fromList : elem list * elem -> array

fromList (lst, dflt) returns a new array created from the elements of lst and with default value dflt. The bound of the array will be length lst - 1.

val toList : 'a array -> 'a list

toList arr returns a list of the array’s contents. The resulting list will have the array’s bound plus one elements.

val tabulate: int * (int -> elem) * elem -> array

tabulate (sz, init, dflt) returns a new array with the first sz elements initialized using the function init and the default value dflt. This function raises the Size exception if sz < 0.

val default : array -> elem

default arr returns the default value for the array.

val sub : array * int -> elem

sub (arr, ix) returns the value of the array at index ix. If that value has not been explicitly set, then it returns the array’s default value. This function raises the Subscript exception if ix < 0.

val update : array * int * elem -> unit

update (arr, ix, v) sets the value at index ix of the array to v. If ix is greater than the current bound of the array, then the bound is set to ix. This function raises the Subscript exception if ix < 0.

val bound : array -> int

bound arr returns the current bound of the array, which is the highest index that has been explicitly set (e.g., by update).

val truncate : array * int -> unit

truncate (arr, sz) sets every entry with index greater or equal to sz to the array’s default value.