Heresy! Combining type systems with PHP
Josh Watzman, engineer at Facebook.
Hack is Facebook's dialect of PHP. One of the major features of Hack is its strong, static type system. This technical talk describes how Hack adds a type system onto a dynamic, untyped language like PHP. The talk goes into detail on both the type system as well as the static typechecker that enforces it. In particular, the talk focuses on how Hack does all of these things without compromising the core of what makes PHP an incredibly productive language to work in.