The import statement.

  import Foo
  --> Import "Foo Nothing Nothing


  import Foo.Bar
  --> Import "Foo.Bar" Nothing Nothing


  import Foo as F
  --> Import "Foo" (Just "F") Nothing


  import Foo exposing (..)
  --> Import "Foo" Nothing (Just ExposingAll)


  import Foo as F exposing (..)
  --> Import "Foo" (Just "F") (Just ExposingAll)