LispEngine.Evaluation.LexicalEnvironment.checkCached C# (CSharp) Метод

        private static Binding checkCached(LexicalEnvironment e, Symbol symbol)
        {
            if (symbol.Env == null)
                return null;
            while(e != null)
            {
                if (ReferenceEquals(symbol.Env, e))
                    return symbol.CachedBinding;
                e = e.parent;
            }
            return null;
        }