What (regarding SPDX) does this help with?

(This is a request for docu, in the README)

Looking at the README, my guess is that this is an parser + AST for SPDX license expressions. is it anything else, anything more, or is this assumption wrong?

Personally, I am looking for a way to convert SPDX-license-expressions into their RDF equivalent.

... even if it is "just" the parser + AST, it would already be very cool and helpful though; thank you! :-)
either way though, I would wish for it to be clear from the README.