What's a conditerator?
tierratemplates.com
tierratemplates.com
Conditional markup is necessary somewhere in the system - this puts it in the templates in more compact form that won't break like the multi-line block in the example.
If you put the markup in the controller then you blur the line in the MVC architecture.
{@ users ? before: "<div id='users'>Users<ol>" each: "<li>{fullname}</li>" after: "</ol></div>" else: "No users found" @}
I prefer to use something that is more readable, even it is more lines of code.