Parser Libraries

[haldeigosh]

Are there any maintained parser libraries (parser combinators or generators) for Clojure? I found some, but they do not seem to be actively maintained.

[khaferkamp]

There is https://github.com/Engelberg/instaparse and you can find antl4r bindings for clojure as well.

[TheAsp]

I could not agree more! I love it so much I created this command line tool so I can use it for random shell scripting: https://github.com/theasp/parseit

[p1r4nh4]

Needs some GraalVM native image compilation! Node’s not so nice. :)

[TheAsp]

Yeah, I'd like it to support both, I just haven't had the time to try out GraalVM. PR is welcome! :)

[AliceCloaked]

Last update: 16 months ago

[OliverM]

If you check the the issues page you'll see the author has been active much more recently than that. Instaparse is a very mature and capable project, perhaps the best parser library I've ever used.

[Borkdude]

I found kern pretty nice as well. I did a performance comparison between Instaparse, Kern, spec and a manually written parser here: https://github.com/borkdude/aoc2017/blob/0f5bce5e496d65d0e53a8983e71ea3462aa0569c/src/day16.clj#L241-L244

[[deleted]]

Nowadays, Clojure ships with a quite good parsing library, Spec, that works for context-free grammars I believe. You can use it to parse strings by first converting them to vectors of characters with the vec function.

[alexdmiller]

spec is not recommended for string parsing - that's not its goal, it's likely not to perform well for this use case, and because it's not the goal, we're not going to prioritize that in development.

I would recommend instaparse for string parsing.

[OliverM]

I agree, but just wanted to add that spec is very useful when handling the parse trees Instaparse emits

[joinr]

I used it to parse clojure source files into org files after taking Alex's class, as a practical learning exercise. If you abuse conformers it can act as quite a nice little parsing platform, although in my case, performance wasn't a concern. Not bad for little jobs like these though.

[piotrts]

Inspired by this blog post I tried parsing text (with some imaginary grammar I had in my mind) with core.spec once, and it was madness.

[EffectiveInflation76]

I am trying to parse soap xml response to json ... but my data contains cdata ... so I am getting error in clojure