https://github.com/tc39/proposal-record-tuple/issues/10#issuecomment-573845975

hash.js

const r1 = #{
  a: 1,
  b: 2,
  c: 3,
};

const r2 = #{
  a: #{
    b: #{
      c: 123,
    },
    d: 456,
  },
  e: 789,
};

const t1 = #[];

const t2 = #[1,2,3];

const t3 = #[1, #[2, 3, #[4], 5], 6];

pipe.js

const r1 = {|
  a: 1,
  b: 2,
  c: 3,
|};

const r2 = {|
  a: {|
    b: {|
      c: 123,
    |},
    d: 456,
  |},
  e: 789,
|};

const t1 = [||];

const t2 = [|1,2,3|];

const t3 = [|1, [|2, 3, [|4|], 5|], 6|];