Dear hackers,
I am submitting a patch to expand the label requirements for ltree.
The current format is restricted to alphanumeric characters, plus _. Unfortunately, for non-English labels, this set is insufficient. Rather than figure out how to expand this set to include characters beyond the ASCII limit, I have instead opted to provide users with some mechanism for storing encoded UTF-8 characters which is widely used: punycode (
https://en.wikipedia.org/wiki/Punycode).
The punycode range of characters is the exact same set as the existing ltree range, with the addition of a hyphen (-). Within this system, any human language can be encoded using just A-Za-z0-9-.
On top of this, I added support for two more characters: # and ;, which are used for HTML entities. Note that & and % have special significance in the existing ltree logic; users would have to encode items as #20; (rather than %20). This seems a fair compromise.
Since the encoding could make a regular slug even longer, I have also doubled the character limit, from 256 to 512.
Please let me know if I can provide any more information or changes.
Very sincerely,
Garen
