Nemerle

def x = 1;           // int
def myList = List(); // generic List[T], type T is deduced from the usage in the next line
myList.Add(x);       // compiler deduces type of T as int making myList type of List[int]

def x =
  { // similar to x = 3
    def y = 1;
    def z = 2;
    y + z   // this last statement is a block return value
  };

def x =
  if (DateTime.Now.DayOfWeek == DayOfWeek.Monday)  // if, using, try are also expressions
    "Monday"
  else
    "other day";

def x = try int.Parse(someString)
        catch { | FormatException() => 0 };

def x = returnBlock : 
  {
    foreach (i in [1, 2, 3])
      when (i > 2)
        returnBlock(true); // exit block (x = true)

    false // x = false
  };

def k = (1, "one"); // k : (int * string)
def (a, b) = k; // a = 1, b = "one"

def result = match (number)
{
  | 0            => "zero"
  | 1            => "one"
  | x when x < 0 => "negative"
  | _            => "more than one"
}

using System.Console; // classes and modules (static classes) can be put in namespaces
def next(x) { x + 1 }; // the type of x argument and other function arguments can be deduced from usage

def mult(x, y) { x * y };

def fibonacci(i)
{
  | 0     => 0
  | 1     => 1
  | other => fibonacci(i - 1) + fibonacci(i - 2)
};

WriteLine(next(9));        // 10  similar to "Console.WriteLine(next(9));" 
WriteLine(mult(2, 2));     // 4
WriteLine(fibonacci(10)); // 55

 variant RgbColor {
   | Red
   | Yellow
   | Green
   | Different {
       red : float;
       green : float;
       blue : float;
     }
 }

macro @if (cond, e1, e2)
syntax ("if", "(", cond, ")", e1, Optional (";"), "else", e2)
{
  /*
    <[ ]> defines an area of quasi-quotation, the Nemerle compiler transforms the code in it 
    to an AST, such transformations are somewhat similar to an Expression compiling in C#
  */
  <[
    match ($cond : bool)
    {
      | true => $e1
      | _ => $e2
    }
  ]>
}

// using this macro in code:
def max = if (a > b) a else b;
// during a compile time the upper line will be transformed to this:
def max = match (a > b)
{
  | true => a
  | _    => b
}

using System.Console;

[Qux]
class FooBar {
  public static Main(): void {
    WriteLine("Hello")
  }

  static Foo (x: int): void {
    if (x == 3) {
      def y = x * 42;
      Foo (x)
    } else {
      [x].Map (fun (x) {
        x * 2
      })
    }
  }

  static Bar(): int {
    def foo = 2 + 7 * 13;
    foo
  }
}

using System.Console;

[Qux] \
class FooBar
  public static Main(): void
    WriteLine("Hello")

  static Foo (x: int): void
    if (x == 3) 
      def y = x * 42;
      Foo (x)
    else
      [x].Map (fun (x) {
        x * 2
      })

  static Bar(): int
    def foo = 2 + 7 * 13
    foo

// This will not compile ...

static Bar(): int
  def foo = 2 
     + 7 
     * 13
  foo

match (s)
  | "a"
  | "aa" => 1
  | "b"
  | "bb" => 2
  | _ => 0
 
// But this will:

static Bar(): int
  def foo = 2 \ 
     + 7 \
     * 13
  foo

match (s)
  | "a" \
  | "aa" => 1
  | "b" \
  | "bb" => 2
  | _ => 0

class Hello
{
  static Main () : void
  {
    System.Console.WriteLine ("Hello, world!");
  }
}

System.Console.WriteLine("Hello, world!");

def s = $"The number is $i"; //insert the value of the variable i where $i is placed 
def s = $"$x + $y = $(x+y)"; // $(...) can be used to make calculations or access members

[StructuralEquality] // Implement IEquatable[Sample] .Net interface using by element comparison equality.
class Sample
{
   [Memoize]  // remember first evaluation result 
   public static SomeLongEvaluations() : int  
   {
       MathLib.CalculateNthPrime(10000000)
   }

   [DependencyProperty] // WPF dependency property
   public DependencyPropertySample { get; set; }
   
   public static Main() : void
   {
/* syntax macro "json" generates code: 
JObject.Object([("a", JValue.Number(SomeLongEvaluations())), ("b", JValue.Number(SomeLongEvaluations() + 1))])
*/
       def jObject = json { a: SomeLongEvaluations(); b: (SomeLongEvaluations() + 1)} 
// object initialization macro "<-" is development of C# curly brackets object initialization
       def k = Diagnostics.Process() <- 
       {
          StartInfo <- // can init inner objects properties without ctor call
          {
              FileName = "calc.exe";
              UseShellExecute = true;
          }   
          Exited += () => WriteLine("Calc done"); // events and delegates
       }

       ReadLine();
   }
}

ExecuteReaderLoop("SELECT firstname, lastname FROM employee WHERE firstname = $myparm", dbcon,
  {
    WriteLine ($"Name: $firstname $lastname")
  });

string sql = "SELECT firstname, lastname FROM employee WHERE firstname = :a";
using (NpgsqlCommand dbcmd = new NpgsqlCommand (sql, dbcon, dbtran))
{
  dbcmd.Parameters.Add("a", myparm);

  using (NpgsqlReader reader = dbcmd.ExecuteReader())
  {
     while(reader.Read()) 
     {
        var firstname = reader.GetString (0);
        var lastname = reader.GetString (1);
        Console.WriteLine ("Name: {0} {1}", firstname, lastname)
     }
  }
}

macro ReverseFor (i, begin, body)
syntax("ford", "(", i, ";", begin, ")", body)
{
   <[ for ($i = $begin; $i >= 0; $i--) $body ]>
}