I was wrong about this. Case is a macro (a special-cased macro even, defined at https://github.com/elixir-lang/elixir/blob/4def31f8abea5fba44d2d92b11a72f3f9c855

I was wrong about this. Case is a macro (a special-cased macro even, defined at https://github.com/elixir-lang/elixir/blob/4def31f8abea5fba44d2d92b11a72f3f9c855efd/lib/elixir/src/elixir_clauses.erl#L236 https://github.com/elixir-lang/elixir/blob/4def31f8abea5fba4...), not a function. It works with pipes because in the AST it's a call, unlike in Haskell where case is its own thing.