Your example here:
%{foo: :bar, "yes, this compiles": :"also an atom"}
Both of them are atoms; :“also an atom” and :“yes, this compiles” are both atoms. Your syntax hilighter thinks that “yes, this compiles” is a string.
iex(1)> %{ "yes, this compiles": :"also an atom" } |> Enum.map(fn {key, val} -> is_atom key end)
[true]
