Question

I’m still new to functional programming so if I can’t figure out how to do something I revert back to procedural style. I found a way to get around having to convert to a list but I’d still like to know how.

Here is my attempt to convert a two dimensional array to a list.

let board = Array2.init 10 20 (fun i j -> pull(i, j))  let mutable pieces = []  board |> Array2.mapi (fun i j a -> transform(i, j, a)) |> Array2.iter (fun a -> (pieces <- a :: pieces)) 

Answer 1

Apparently in .Net, multi-dimensional arrays are IEnumerable (non-generic), and thus this works:

let a2 = Array2.init 2 3 (fun x y -> (x+1)*(y+1)) let l = a2 |> Seq.cast<int> |> Seq.fold (fun l n -> n :: l) [] printfn '%A' l 

EDIT: As Noldorin points out in a comment, this is even better:

let l = a2 |> Seq.cast<int> |> Seq.toList