It's been a bit of a disappointment for me to discover that AsciiDoc's grammar is so complex that they didn't even describe it in a spec. Their spec is a collection of tests.
This must be contributing a lot to the adoption difficulty (at least for resource-limited open-source projects). There's a good chance you will not find an AsciiDoc parser library for your favourite programming language.
If you mean libasciidoc for Go, it does not support all the AsciiDoc features [1]. The JS parser is transpiled [2] from the Ruby implementation (which is not a bad thing, it's just something most languages can't have).
My favourites are Rust and Haskell. Neither of them had a parcer until recently (even though the original implementation has been around for a few years now). Both are at early development stages at the moment.
This must be contributing a lot to the adoption difficulty (at least for resource-limited open-source projects). There's a good chance you will not find an AsciiDoc parser library for your favourite programming language.