Solution for question 3 Koan of Edx F# Module 2

fsharp-module-2.fs

open System

let readIntValue () : int =
    let canparse, keyin = Int32.TryParse(Console.ReadLine())
    if canparse then keyin
    else 0

let readPerson (index : int) : (string * int) =
    Console.WriteLine("info of person number {0}", index)
    Console.WriteLine("Enter name: ")
    let name = Console.ReadLine()
    Console.WriteLine("Enter age: ")
    let age = readIntValue()
    ( name, age )

let messageDependingOfAge (name : string, age : int) : string =
    if (age <= 13) then name + " is a kid or child"
    elif (age < 20) then name + " is a teenager"
    else name + " is no longer a teenager"

[<EntryPoint>]    
let main argv =
    Console.WriteLine("How many people will you enter ?")
    let repeatCount = Console.ReadLine()
    let repeatCount = int repeatCount

    Console.WriteLine("You will enter {0} person(s)", repeatCount)
    let listOfPerson = [ for i in 1..repeatCount do yield readPerson(i) ]
    for (name, age) in listOfPerson do
        Console.WriteLine(messageDependingOfAge(name, age))

    let c = Console.ReadKey()
    0 // return an integer exit code