//найти в словаре значение и вернуть его ключ
mutable vv = -1;
foreach(k in Card.ValencyDict.Keys)
{
    when( Card.ValencyDict[k] == v )
    {
        vv = k;
        break;
    }

def vv():int {
   -1;
   foreach(k when Card.ValencyDict[k] == v in Card.ValencyDict.Keys)
   {
      k;
   }
}
Valency = vv();

MAM>//найти в словаре значение и вернуть его ключ
MAM>mutable vv = -1;
MAM>foreach(k in Card.ValencyDict.Keys)
MAM>{
MAM>    when( Card.ValencyDict[k] == v )
MAM>    {
MAM>        vv = k;
MAM>        break;
MAM>    }
MAM>

def vv = res: {
  foreach (k in Card.ValencyDict.Keys)
    when (Card.ValencyDict[k] == v)
      res(v);
  -1 // default value
};

def vv =  Card.ValencyDict.Find(kv => kv.Value == v).WithDefault(-1);

STD>def vv =  Card.ValencyDict.Find(kv => kv.Value == v).WithDefault(-1);
STD>

def vv = if(Card.ValencyDict.Find(kv => kv.Value == v) is Some(kv)) kv.Value else -1;

def vv = Card.ValencyDict.Select(_.Value).Find(_ == v).WithDefault(-1);

STD>def vv = Card.ValencyDict.Select(_.Value).Find(_ == v).WithDefault(-1);
STD>

    def vv = res : {
        foreach(k in Card.ValencyDict.Keys)
            when( Card.ValencyDict[k] == v )
                res(k);
        -1;
    }

        def dict = Hashtable.[int, string]();
        def v    = "sd";
        def vv   = dict.Find(kv => kv.Value == v).Map(_.Key).WithDefault(-1);
        def vv   = if(dict.Find(kv => kv.Value == v) is Some(x)) x.Key else -1;
        def vv   = dict.Where(kv => kv.Value == v).Select(_.Key).DefaultIfEmpty(-1).First();
        def vv   = dict.MapLazyFiltered(kv => kv.Value == v, _.Key).DefaultIfEmpty(-1).First();

def vv = find (e when e.Value == v in Card.ValencyDict) k notfound -1;