Imperative vs. Declarative Excerpts

DeclarativeExcerpt.cs

return parser.ServiceNode.Nodes.OfType<TreeNode>()
		     .SelectMany(n => n.Nodes.OfType<TreeNode>())
		     .Single(n => n.Text == Protocol.Values[(int)protocol])
		     .Nodes.OfType<TreeNode>();

ImperativeExcerpt.cs

var endpoints = new List<TreeNode>();
foreach (var service in parser.ServiceNode.Nodes.OfType<TreeNode>())
{
    foreach (var acceptedProtocol in service.Nodes.OfType<TreeNode>())
    {
        if (acceptedProtocol.Text == Protocol.Values[(int)protocol])
        {
            if (foundProtocol)
            {
                throw new DuplicateProtocolException(String.Format("Protocol {0} found more than once.", acceptedProtocol.Text)); //==Linq's .Single()
            }

            foundProtocol = true;
            endpoints.AddRange(acceptedProtocol.Nodes.OfType<TreeNode>());
        }
    }
}
return endpoints;