Structures | Signatures | Identifiers

Signature VECTOR

Operations on polymorphic vectors.

structure Vector : VECTOR

signature VECTOR = 
  sig
    type 'a vector = 'a vector

    val maxLen   : int

    val fromList : 'a list -> 'a vector
    val tabulate : int * (int -> 'a) -> 'a vector

    val length   : 'a vector -> int
    val sub      : 'a vector * int -> 'a
    val update   : 'a vector * int * 'a -> 'a vector
    val concat   : 'a vector list -> 'a vector
                                     
    val appi     : (int * 'a -> unit) -> 'a vector -> unit
    val app      : ('a -> unit) -> 'a vector -> unit
                                                
    val mapi     : (int * 'a -> 'b) -> 'a vector -> 'b vector
    val map      : ('a -> 'b) -> 'a vector -> 'b vector
                                              
    val foldli   : (int * 'a * 'b -> 'b) -> 'b -> 'a vector -> 'b
    val foldri   : (int * 'a * 'b -> 'b) -> 'b -> 'a vector -> 'b
                                                               
    val foldl    : ('a * 'b -> 'b) -> 'b -> 'a vector -> 'b
    val foldr    : ('a * 'b -> 'b) -> 'b -> 'a vector -> 'b
                                                         
    val findi    : (int * 'a -> bool) -> 'a vector -> (int * 'a) option
    val find     : ('a -> bool) -> 'a vector -> 'a option
    val exists   : ('a -> bool) -> 'a vector -> bool
    val all      : ('a -> bool) -> 'a vector -> bool
    val collate  : ('a * 'a -> order) -> 'a vector * 'a vector -> order 
  end

[maxLen]

The maximum length of vectors supported by this implementation. Attempts to create larger vectors will result in the Size exception being raised.

[fromList l]

creates a new vector from l, whose length is length l and with the i(th) element of l used as the i(th) element of the vector. If the length of the list is greater than maxLen, then the Size exception is raised.

[tabulate (n, f)]

creates a vector of n elements, where the elements are defined in order of increasing index by applying f to the element's index. This is equivalent to the expression (fromList (List.tabulate (n, f))). If n < 0 or maxLen < n, then the Size exception is raised.

[length vec]

returns |vec|, the length of the vector vec.

[sub (vec, i)]

returns the i(th) element of the vector vec. If i < 0 or |vec| <= i, then the Subscript exception is raised.

[update (vec, i, x)]

returns a new vector, identical to vec, except the i(th) element of vec is set to x. If i < 0 or |vec| <= i, then the Subscript exception is raised.

[concat l]

returns the vector that is the concatenation of the vectors in the list l. If the total length of these vectors exceeds maxLen, then the Size exception is raised.

[appi f vec]

[app f vec]

These apply the function f to the elements of a vector in left to right order (i.e., in order of increasing indices). The more general appi function supplies both the element and the element's index to the function f. These are respectively equivalent to:

      List.app f (foldri (fn (i,a,l) => (i,a)::l) [] vec)
      List.app f (foldr (fn (a,l) => a::l) [] vec)

[mapi f vec]

[map f vec]

These functions produce new vectors by mapping the function f from left to right over the argument vector. The more general form mapi supplies f with the vector index of an element along with the element. These are respectively equivalent to:

      fromList (List.map f (foldri (fn (i,a,l) => (i,a)::l) [] vec))
      fromList (List.map f (foldr (fn (a,l) => a::l) [] vec))

[foldli f init vec]

[foldri f init vec]

[foldl f init vec]

[foldr f init vec]

These fold the function f over all the elements of a vector, using the value init as the initial value. The functions foldli and foldl apply the function f from left to right (increasing indices), while the functions foldri and foldr work from right to left (decreasing indices). The more general functions foldli and foldri supply both the element and the element's index to the function f. See the MONO_ARRAY manual pages for reference implementations of the indexed versions. The last two expressions are respectively equivalent to:

      foldli (fn (_, a, x) => f(a, x)) init vec
      foldri (fn (_, a, x) => f(a, x)) init vec

[findi f vec]

[find f vec]

These apply f to each element of the vector vec, from left to right (i.e., increasing indices), until a true value is returned. If this occurs, the functions return the element; otherwise, they return NONE. The more general version findi also supplies f with the vector index of the element and, upon finding an entry satisfying the predicate, returns that index with the element.

[exists f vec]

applies f to each element x of the vector vec, from left to right (i.e., increasing indices), until f(x) evaluates to true; it returns true if such an x exists and false otherwise.

[all f vec]

applies f to each element x of the vector vec, from left to right (i.e., increasing indices), until f(x) evaluates to false; it returns false if such an x exists and true otherwise. It is equivalent to not(exists (not o f ) vec)).

[collate f (v1, v2)]

performs lexicographic comparison of the two vectors using the given ordering f on elements.