These provide N-dimensional, zero-based arrays and
are in the structure arrays.
The array interface is derived from one invented by Alan Bawden.
(make-array value dimension0 ...) -> array
(array dimensions element0 ...) -> array
(copy-array array) -> array
Make-array makes a new array with the given dimensions, each of which
must be a non-negative integer.
Every element is initially set to value.
Array Returns a new array with the given dimensions and elements.
Dimensions must be a list of non-negative integers,
The number of elements should be the equal to the product of the
dimensions.
The elements are stored in row-major order.
(make-array 'a 2 3)->{Array 2 3} (array '(2 3) 'a 'b 'c 'd 'e 'f)->{Array 2 3}
Copy-array returns a copy of array.
The copy is identical to the array but does not share storage with it.
#t if value is an array.
(array-ref array index0 ...) -> value
(array-set! array value index0 ...)
(array->vector array) -> vector
(array-dimensions array) -> list
Array-ref returns the specified array element and array-set!
replaces the element with value.
(let ((a (array '(2 3) 'a 'b 'c 'd 'e 'f)))
(let ((x (array-ref a 0 1)))
(array-set! a 'g 0 1)
(list x (array-ref a 0 1))))
-> '(b g)
Array->vector returns a vector containing the elements of array
in row-major order.
Array-dimensions returns the dimensions of
the array as a list.
Make-shared-array makes a new array that shares storage with array
and uses linear-map to map indexes to elements.
Linear-map must accept as many arguments as the number of
dimensions given and must return a list of non-negative integers
that are valid indexes into array.
<
(array-ref (make-shared-array a f i0 i1 ...)
j0 j1 ...)
(apply array-ref a (f j0 j1 ...))
As an example, the following function makes the transpose of a two-dimensional array:
(define (transpose array)
(let ((dimensions (array-dimensions array)))
(make-shared-array array
(lambda (x y)
(list y x))
(cadr dimensions)
(car dimensions))))
(array->vector
(transpose
(array '(2 3) 'a 'b 'c 'd 'e 'f)))
-> '(a d b e c f)