There’s two parts to this. There’s the elixir parser, which requires you to write correct elixir syntax. Otherwise it cannot parse the code. Once the code is parsed by the parser (into AST) macros can come in and change their input AST – could be code blowing up when trying to be executed – to some different output AST – which hopefully runs just fine when executed.
MyStruct my_var = isn’t valid elixir syntax – quote do: MyStruct my_var = 1 doesn’t succeed, so there’s nothing a macro could do here.
Not really sure why you’d like this to change the syntax here. If you want the structs be listed why not write %MyStruct{} = my_var = …? That just works and can even help out editor autocomplete.
