Coerce bidimensional array into list

[Ferreira]

I know I can use the coerce function to make a list from a given array, However, when I give it a multidimensional array I get a list of all elements.

Is there any "easy way" to get ((1 2) (3 4)) from #((1 2) (3 4))?

Thanks in advance.

[ramarren]

Is there any "easy way" to get ((1 2) (3 4)) from #((1 2) (3 4))?

Actually, #((1 2) (3 4)) is a vector of two elements, both of which are lists, so you can:

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[1]> #((1 2)(3 4))
#((1 2) (3 4))
[2]> (coerce #((1 2)(3 4)) 'list)
((1 2) (3 4))

Real two dimensional arrays (with read syntax like #2A((1 2)(3 4)) ) are not sequences, and so as far as I know there is no built in way to transform them into nested list. But it is easy enough with a simple nested loop, like for example:

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(defun to-list (2d-array)
  (loop for i from 0 below (array-dimension 2d-array 0)
        collect (loop for j from 0 below (array-dimension 2d-array 1)
                      collect (aref 2d-array i j))))

CL-USER> (to-list #2A((1 2)(3 4)))

((1 2) (3 4))

[dmitry_vk]

I know I can use the coerce function to make a list from a given array, However, when I give it a multidimensional array I get a list of all elements.

Is there any "easy way" to get ((1 2) (3 4)) from #((1 2) (3 4))?

Thanks in advance.

You can use :initial-contents keyword argument for make-array:

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(make-array '(2 2) :initial-contents '((1 2) (3 4)))
=>
#2A((1 2) (3 4))