var sha1Bytes = SHA1Managed().ComputeHash(UTF8Encoding().GetBytes(String.Format("{0}{1}", param1, param2));
var stringBuilder = StringBuilder();
for (var i = 0; i < sha1Bytes.Length; i++) 
    stringBuilder.Append(sha1Bytes[i].ToString("x2"));
var sha1 = stringBuilder.ToString();

def sha1 = $<#..$(SHA1Managed().ComputeHash(UTF8Encoding().GetBytes($"$param1$param2")); ""; _.ToString("x2"))#>;

KV>def sha1 = $<#..$(SHA1Managed().ComputeHash(UTF8Encoding().GetBytes($"$param1$param2")); ""; _.ToString("x2"))#>;
KV>

string sha1 = string.Join("", SHA1Managed().ComputeHash(UTF8Encoding().GetBytes(string.Format("{0}{1}", param1, param2)), x=>x.ToString("x2"));

Dictionary<int, int> VeryLongPureEvaluationCache = new Dictionary<int, int>();
int VeryLongPureEvaluation(int arg)
{
   if (VeryLongPureEvaluationCache.ContainsKey(arg))
     return VeryLongPureEvaluationCache[arg];

   // evaluation

   VeryLongPureEvaluationCache[arg] = result;

   return result;
}

[Memoize]
VeryLongPureEvaluation(arg : int) : int
{
   // evaluation
}

Z>[Memoize]
Z>VeryLongPureEvaluation(arg : int) : int
Z>{
Z>   // evaluation
Z>}
Z>

readonly LazyCache<int, int> VeryLongPureEvaluationCache = new LazyCache<int, int>((arg) => 
  {
    // evaluation 
  }
);

int VeryLongPureEvaluation(int arg)
{
  return VeryLongPureEvaluationCache.GetOrCalc(arg);
}

regexp match (str) {
    | "a+.*" => printf ("a\n");
    | @"(?<num : int>\d+)-\w+" => printf ("%d\n", num + 3);
    | "(?<name>(Ala|Kasia))? ma kota" =>
         match (name) {
             | Some (n) => printf ("%s\n", n)
             | None => printf ("noname?\n")
         }
    | _ => printf ("default\n");
}

if (str == null)
{
    Console.WriteLine("default");
}
else
{
    var regexObj = new Regex(@"(?<g1>^a+.*$)|(?<g2>^(?<num>\d+)-\w+$)|(?<g3>^(?<name>(Ala|Kasia))? ma kota$)", RegexOptions.ExplicitCapture | RegexOptions.Compiled);
    var match = regexObj.Match(str);
    if (match.Success)
    {
        if (match.Groups["g3"].Success)
        {
            if (!(match.Groups["name"].Success))
            {
                Console.WriteLine("noname?");
            }
            else
            {
                Console.WriteLine(match.Groups["name"].Value);
            }
        }
        else if (match.Groups["g2"].Success)
        {
            Console.WriteLine(int.Parse(match.Groups["num"].ToString()) + 3);
        }
        else
        {
            Console.WriteLine("a");
        }
    }
    else
    {
        Console.WriteLine("default");
    }
}