EditorFor and DisplayFor when using custom templates and IEnumerables

MvcExtensions.cs

 public static class MvcExtensions
    {
        public static MvcHtmlString EditorForEnumerable<TModel, TValue>(this HtmlHelper<TModel> html, Expression<Func<TModel, IEnumerable<TValue>>> expression, string templateName)
        {
            var fieldName = html.NameFor(expression).ToString();
            var items = expression.Compile()(html.ViewData.Model);
            return new MvcHtmlString(string.Concat(items.Select((item, i) => html.EditorFor(m => item, templateName, fieldName + '[' + i + ']'))));
        }

        public static MvcHtmlString DisplayForEnumerable<TModel, TValue>(this HtmlHelper<TModel> html, Expression<Func<TModel, IEnumerable<TValue>>> expression, string templateName)
        {
            var fieldName = html.NameFor(expression).ToString();
            var items = expression.Compile()(html.ViewData.Model);
            return new MvcHtmlString(string.Concat(items.Select((item, i) => html.DisplayFor(m => item, templateName, fieldName + '[' + i + ']'))));
        }
    }