Simple Ruby-esque option/hash value passing.

Option.cs

        class Option
        {
            public string Name { get; private set; }
            public string Value { get; private set; }

            private Option(Expression<Func<string, string>> action)
            {
                this.Name = ToCommand(action.Parameters[0].Name);
                if (this.Name == "klass")
                    this.Name = "class";
                this.Value = action.Compile()(null);
            }

            private static string ToCommand(string name)
            {
                return new Regex("[a-z][A-Z]").Replace(name, match => match.Value.Substring(0,1) + "-" + match.Value.Substring(1,1).ToLower());
            }

            public static implicit operator Option(Expression<Func<string, string>> action)
            {
                return new Option(action);
            }
        }

SampleUsage.cs

// WriteTag("script", script => { }, text => "text/javascript", id => "script_id");

        public void WriteTag(string tagName, Action<HtmlReportWriter> contents = null, params Expression<Func<string, string>>[] attributes)
        {
            _writer.WriteStartElement(tagName);

            foreach (Option attribute in attributes)
                _writer.WriteAttributeString(attribute.Name, attribute.Value);

            if (contents != null)
                contents(this);

            _writer.WriteEndElement();
        }

That's pretty clever. Yet simple. I like it :) I'll have to remember this ^_^

You should send this to ASP.NET MVC team. It will make writing the option things they have where they use anonymous types much nicer to read :D

Thanks. A word of warning... this technique should only be used with simple types/values i.e. no actual functions for options as the code generated for it may have some major performance issues.