Up to date syntax documentation?

[Philippe Marschall]

Hi

I'm looking for an up to date syntax documentation for the 
module-info.java. Specifically I'm looking for the syntax for optional 
dependencies and specifying the main class. The most up to date 
information I could find was [1] but this doesn't cover optional 
dependencies. Googling suggests the following syntax

require optional module-name;

But this doesn't seem to work. Googling also suggests there is/was 
syntax for specifying the main class but none of the example seem to 
work anymore.

  [1] http://openjdk.java.net/projects/jigsaw/quick-start

Cheers
Philippe