Hpack is a format for Haskell packages. It is a modern alternative
to the Cabal package format and follows different design principles.

The guiding design principles for Hpack are:

* Don't require the user to state the obvious,
  make sensible assumptions by default
* Give the user 100% control when needed
* Don't require the user to repeat things, facilitate DRYness

Hpack packages are described in a file named package.yaml. Both cabal2nix
and stack support package.yaml natively. For other build tools the hpack
executable can be used to generate a .cabal file from package.yaml.