Supporting syntax `x not in y` as alias for `!(x in y)`

Internals & Design
30

You are wrong:

julia> :( for i in itr end )
:(for i = itr
      #= REPL[1]:1 =#
      #= REPL[1]:1 =#
  end)

julia> :( (x for x in itr) )
:((x for x = itr))

(sorry, I’m sure this isn’t what you meant :wink: )