chickadee » generalized-arrays » array-shape

array-shape arrayprocedure

Returns the shape of a given array. The shape of an array is the default interval up to the maximum length of each dimension of the array or view. Unlike array-interval, the shape of an array always starts at the default (zero) index, and ends at the maximum dimension of the array.

In almost all instances, array-shape is the way one should get the full interval of indices in a given array. While array-interval provides the actual interval used to index into the storage-object of the array, array-shape is more useful when using most array APIs (e.g. array-ref); of which, these APIs will expect an array that is in the bounds of the shape rather than the interval, which is meant to be a tool for developers who are operating on the raw, underlying array structure directly.

(import generalized-arrays)

(define a
  (make-array vector-storage-class
              #(3 3)

(test "Shape of array a"
      (make-interval #(0 0) #(3 3))
      (array-shape a))

(define b
  (array-slice a #(1 1) #(2 3)))

(test "Interval of array b"
      (make-interval #(1 1) #(2 3))
      (array-interval b))

(test "Shape of array b"
      (make-interval #(0 0) #(1 2))
      (array-shape b))