private static IEnumerable<string> Template(string source, Match[] matches)
{
if (matches.Length == 0)
yield return source;
else
{
var head = matches.First();
var tail = matches.Skip(1).ToArray();
var items = head.Result("$1").Split(',').Select(x => x.Trim()).ToList();
var templates = Template(source, tail).ToList();
foreach (var template in templates)
foreach (var item in items)
yield return template.Remove(head.Index, head.Length).Insert(head.Index, item);
}
}
