Question

Is there some way to convert between F# List and F# Tuple?

For example:

[1;2;3] -> (1,2,3)    
(1,2,3,4) -> [1;2;3;4]

I need two Functions to do that:

let listToTuple list = ...
let tupleToList tuple = ...

Thank you in advance.

Answer 1

Besides listToTuple then pblasucci has the right answer.
But you wont be happy with the result unless you know something about type types involved, or if you wan’t to do a lot of boxing and unboxing.

let tupleToList t = 
    if Microsoft.FSharp.Reflection.FSharpType.IsTuple(t.GetType()) 
        then Some (Microsoft.FSharp.Reflection.FSharpValue.GetTupleFields t |> Array.toList)
        else None

let listToTuple l =
    let l' = List.toArray l
    let types = l' |> Array.map (fun o -> o.GetType())
    let tupleType = Microsoft.FSharp.Reflection.FSharpType.MakeTupleType types
    Microsoft.FSharp.Reflection.FSharpValue.MakeTuple (l' , tupleType)