Elixir allows overloading the operators or creating custom ones, but only certain symbols are recognized in the parser, to add new operators the Elixir parser needs to be changed.

You can see them here https://github.com/elixir-lang/elixir/blob/master/lib/elixir...

Not all of them are defined in the language, the list of the unused infix operator includes

    \\, <-, |, ~>>, <<~, ~>, <~, <~>, <|>, <<<, >>>, |||, &&&, and ^^^

to define a custom infix operator you can use this syntax

    def left <|> right do
      IO.puts("#{left} <|> #{right}")
    end

    # usage
    left MyModule.<|> right

    # or
    import MyModule
    left <|> right

if the operator is already defined in Kernel, you can exclude it from import and use your own

    import Kernel, except: [{:+, 2}]
    import MyModule

    left + right

as you can see @ is not among them, @ it's not a binary operator and is defined as Kernel.@/1