the unpack half of the efrt library.
See that repo for full documentation.
npm install efrt-unpack<script src="https://unpkg.com/efrt@latest/builds/efrt-unpack.min.js"></script>
<script>
const compressedTrie = 'true¦denmark,o0scandanavia;h0ntar0;io'
const p = unpack(compressedTrie)
console.log(p.hasOwnProperty('ohio'))
// true
</script>MIT