Bart De Smet just wrote a long post about LINQ predicates that can be defined without returning a boolean value.

This is something I partially evaluated writing the Programming Microsoft LINQ book, but in his post Bart goes very deep on this topic and shows a lot of interesting details and ideas.

Originally appeared on: http://sqlblog.com/blogs/marco_russo/archive/2008/09/15/non-boolean-linq-predicates.aspx