F# collections with Option module

22-4_collections-options.fsx

let tryLoadCustomerWithOption customerId =
    // customerId // does not work as function is expecting an option type
    Some customerId // unwrap value first
    |> Option.filter(fun x -> x >= 2 && x <= 7)
    |> Option.map(fun x -> sprintf "Customer %i" x)

let tryLoadCustomer customerId =
    if customerId >= 2 && customerId <= 7 then Some(sprintf "Customer %i" customerId)
    else None

let customerIds = [ 0 .. 10 ]
customerIds |> List.choose tryLoadCustomer