Private/Get-RPSUserSelection.ps1

function Get-RPSUserSelection
{
    [CmdletBinding()]
    [Alias()]
    [OutputType([Choice])]
    Param
    (
    )

    Begin
    {
    }
    Process
    {
        do
        {
            $userChoice = Read-Host -Prompt 'Enter choice: (R)ock, (P)aper, (S)cissors';
            switch ($userChoice)
            {
                'R'{ return [Choice]::Rock } 
                'P'{ return [Choice]::Paper }
                'S'{ return [Choice]::Scissors }
                default {}
            }
        }
        while ( $userChoice -notcontains @('R','P','S') )
    }
    End
    {
    }
}
enum Choice
{
    Rock = 0
    Paper = 1
    Scissors = 2

}