Question

this is example code in C# :

class exampleClass
{
    struct exampleStruct
    {
        public int number;
    }

    private exampleStruct[,] e;                    
    private enum exampleMove { Up, Down, Right, Left, Enter, Escape };
    Stack<int> returnPath;
    bool returntoBeg;
    int numRandomMoves;

    public exampleClass()
    {
        e = new exampleStruct[5, 5];
        exampleStruct ex;
        returntoBeg = false;
        returnPath = new Stack<int>();
        numRandomMoves = 0;

        for (int y = 0; y < 5; y++)
        {
            for (int x = 0; x < 5; x++)
            {
                ex = new exampleStruct();
                ex.number = 0

                e[x, y] = ex;
            }
        }
    }
}

I have an example code like above, i want to translate it into F#. But the problem is, when i make a class using F# and define struct in it, it shows errors and pointing that i can’t declare type inside class type. Any help?

Answer 1

I think the following is a good workaround for nested types.

namespace MyNamespace

module private PrivateTypes =
  [<Struct>]
  type ExampleStruct(number: int) =
    member __.Number = number

open PrivateTypes

type ExampleClass() =
  let e = Array2D.init 5 5 (fun y x -> ExampleStruct(0))
  //other members

ExampleStruct is nested under PrivateTypes, which is only visible in the same file.