It looks similar to stackish and BON (binary object notation) https://github.com/bon-org/bon-doc/blob/master/README.asciidoc https://github.com/bon-org/bon-doc/

It looks similar to stackish and BON (binary object notation) https://github.com/bon-org/bon-doc/blob/master/README.asciidoc https://github.com/bon-org/bon-doc/blob/master/README.asciid... BON is compatible with json+ and erlang data type, in specific, it allows any data type for the map key. Json only allows string as map key.