[fredemmott]

There's also https://github.com/hhvm/hack-codegen/tree/master/examples/do..., along with the article at https://engineering.fb.com/2015/08/20/open-source/writing-co...

This is modern Hack code, but not representative of the state of the Ent framework nowadays - ent/ent is closer design-wise, but not usable from Hack.