(a -> b) -> (a, a) -> (b, b) +array
Returns a new array derived from the original array by applying a function to each of the indices.
Returns a new array derived from the original array by applying a function to each of the elements.
Constructs a new array derived from the original array by applying a function to each of the elements.
Constructs a new array derived from the original array by applying a function to each of the indices.