I am not a nim developer, but as far as I know user defined precedence and
associativity do not work very well with macros.
macro foobar(arg: untyped): stmt =
# bla bla
foobar(foo |> foo |> 123)
now the structure of the ast wich is supposed to be contexd independent, because it is an untyped ast, depends on the context again, in this case the associativity. So to answer your question, I doubt that nim can introduce user defined percedence and associativity.
