rexcfnghk

class Monad m where
  return :: a -> m a
  (>>=) :: m a -> (a -> m b) -> m b

rexcfnghk

module CompositionRoot

    let findPlayerNames' = 
        findPlayerNames "Data Source=localhost; Initial Catalog=MyDb; Integrated Security = True"
  
 module Program
 
     let main _ =
        // Database queried once
        let playerNames1 = findPlayerNames' () |> Seq.toList

rexcfnghk

open System.Data.SqlClient

let findPlayerNames dbConnectionString =
    fun () ->
        use sqlConnection = new SqlConnection (dbConnectionString)
        use sqlCommand = new SqlCommand ("SELECT [Name] FROM Players", sqlConnection)
        use reader = sqlCommand.ExecuteReader ()
        seq { while reader.HasRows do yield reader.["Name"] :?> string }

rexcfnghk

open System.Data.SqlClient

let findPlayerNames dbConnectionString () =
    use sqlConnection = new SqlConnection (dbConnectionString)
    use sqlCommand = new SqlCommand ("SELECT [Name] FROM Players", sqlConnection)
    use reader = sqlCommand.ExecuteReader ()
    seq { while reader.HasRows do yield reader.["Name"] :?> string }

rexcfnghk

var makeObject = function () {
  var s = 1;
  return {
    getState: function() { return s; },
    increment: function() {
      s++;
    }
  };
};

rexcfnghk

function MyObject() {
  this.state = 1;
}

MyObject.prototype.getState = function () {
  return this.state;
};

MyObject.prototype.increment = function () {
  this.state++;

rexcfnghk

void Foo()
{
    var list = new[] { 1, 2, 3, 4, 5 };
    
    for (int i = 0; i < list.Length; i++)
    {
        list[i] *= 2;
    }
    
    // i is not visible here anymore

rexcfnghk

void Foo()
{
    var list = new[] { 1, 2, 3, 4, 5 };
    
    int i = 0;
    while (i < list.Length)
    {
        list[i] *= 2;
        i++;
    }

rexcfnghk

void Foo()
{
    var list = new[] { 1, 2, 3, 4, 5 };
    
    for (int i = 0; i < list.Length; i++)
    {
        list[i] *= 2;
    }
}

rexcfnghk

void Foo()
{
    var list = new[] { 1, 2, 3, 4, 5 };
    
    int i = 0;
    while (i < list.Length)
    {
        list[i] *= 2;
        i++;
    }