pairs of separators from a string

[Marc Chantreux]

hello,

i would like to get the list of opening (α) and closing
(ω) separators from this string:

    &""''(){}[]

too many years of perl made me think about this solution
or something alike but it didn't work.

my (\α,\ω) =| map
    { .[0,2…∞], .[1,3…∞] },
    q&""''(){}[]&.comb;

fixing this is important to me because it illustrate how bad i am to
comprehend how raku flatten things.

regards,
marc