One example of a data structure implementing faceted classification would be the multitree [0]. Unfortunately multitrees seem to receive far less support than 2

One example of a data structure implementing faceted classification would be the multitree [0]. Unfortunately multitrees seem to receive far less support than 2 other data structures it intermediates: trees and DAGs. k-d trees [1] are close but use cases seem to predominantly target data with inherently ordinal (rather than nominal) dimensions. Further abstraction could lead to the knowledge graph [2] or graph databases. In all cases, the availability of "low-code" tools (in the domain of single-user personal information management, at least) seems sparse. I have been looking for some time, but the search continues. [0]: https://en.wikipedia.org/wiki/Multitree https://en.wikipedia.org/wiki/Multitree [1]: https://en.wikipedia.org/wiki/K-d_tree https://en.wikipedia.org/wiki/K-d_tree [2]: https://github.com/JeffreyBenjaminBrown/hode https://github.com/JeffreyBenjaminBrown/hode