Simplified mutable values

simplified-mutable-values.fs

// old approach - need a `ref` value
let sumSquares n =
    let total = ref 0
    { 1 .. n } |> Seq.iter (fun i ->
        total := !total + i*i
    )
    !total

// new approach - `mutable` just works
let sumSquares' n =
    let mutable total = 0
    { 1 .. n } |> Seq.iter (fun i ->
        total <- total + i*i
    )
    total