@trwnh @hongminhee i'm not entirely sure on what you mean (it's about 3am here) but compaction isnt that cheap.flattening and especially framing are the most expensive, and expansion is the cheapest especially since all the other algorithms depend on it (though if you do expand manually before it'll take a fast path out)my argument here is that, if you know the structure you're serializing to (i.e. if you're a contemporary AP implementation that isn't doing anything too fancy), you can directly serialize in compacted form and skip constructing a tree of JSON objects in your library and running the compaction algorithm over it. depending on how clever you(r libraries) get you may be able to directly write the JSON string directly, even.from some brief profiling i've done this does show up as a hot code path in iceshrimp.net, one of my goals with Eventually replacing dotNetRdf with my own impl mentioned above is to, given i'm gonna have to mess with serialization anyhow, remove the JSON-LD bits there and serialize directly to compacted form which should help with large boosts and other bursts
