This all depends on how much support you like to have from your editor. Personally I'm usually happy with just syntax highlighting, which is already covered for

This all depends on how much support you like to have from your editor. Personally I'm usually happy with just syntax highlighting, which is already covered for me[0]. That said, I haven't had the occasion to really make use of Hack. [0] https://github.com/hhvm/vim-hack https://github.com/hhvm/vim-hack