There are a lot of interesting things to pull on here, but I'll reply first with a comment I just wrote that linked back to this thread. https://news.ycombinat

There are a lot of interesting things to pull on here, but I'll reply first with a comment I just wrote that linked back to this thread. https://news.ycombinator.com/item?id=22157587 https://news.ycombinator.com/item?id=22157587 A tentative slogan is "bijections that aren't really bijections", i.e. to describe the "fallacy" of (bytes on disk -> data structure in memory -> bytes). Hence the (slice, data structure) representation. That's the correctness aspect. I also think there's a big performance aspect, e.g. it appears to me that the performance of many/most parsers is dominated by object allocation. Some vaguely related stuff here: https://github.com/oilshell/oil/wiki/Compact-AST-Representation https://github.com/oilshell/oil/wiki/Compact-AST-Representat... Anyway I don't think this will make it into Oil any time in the next year, but I think there is room for it in programming languages, and lots of other people are barking up that tree (e.g. FlatBuffers relate to a big part of it). I would be happy to continue batting around ideas in non-nested HN thread :) So as mentioned elsewhere, feel free to send me a mail or ping me on Zulip! I'm looking at Dercuano but I'm confused why it's a tarball and not a live website :)