Curious why is_not_null doesn't work in this query?

[u9g]

Was messing around on the query playground, but this query seems to fail:

query {
  Latest {
    comment {
      reply @recurse(depth: 10) {
        byUser {
          link {
            url @filter(op: "is_not_null") @output
          }
        }
      }
    }
  }
}

with error:

Incompatible types encountered in @filter.

I also found this query that uses is_not_null that fails with the same error: https://github.com/obi1kenobi/trustfall/blob/main/trustfall/examples/hackernews/README.md#example-jobs-in-the-top-50-items . Maybe a problem with is_not_null, not sure. Is there some other way to do this that I am not seeing?

Anyways, I'm having a blast messing around with queries, thanks for releasing such a cool tool, would love to hear back.

[obi1kenobi]

I'm sorry, that's a terrible error message. It's supposed to show the underlying error text as well — fixing in #278.

In the playground query you posted, that url property is defined as non-nullable in the schema — note the ! in its type:

Filtering for non-null doesn't really make sense on properties that are already guaranteed to be non-null by the schema, hence the error.

Thanks for flagging the bad example query as well. If you'd like to make a PR to fix it, I'd happily merge it and you'll get a shout-out in the next release notes for the contribution :)

[obi1kenobi]

In retrospect I should have just opened that PR way earlier instead of continuing to try and try to replicate the problem 😅

Thanks for the fix! I've queued it up and it should get merged shortly.

Out of curiosity, mind if I ask how you found Trustfall and what drew you to it?

[u9g]

Yeah absolutely, I saw your tweet about you going to new york and looking for people and then linked this project. I took a look at the project and saw your intro video and was stunned. This is like the coolest thing ever, this is what I think the internet should be about, connecting little bits of data together to form a big web of data that people can use.

In any event, more immediately, I kind of want to make some adapters for some things I mess around with manually in js but having trouble finding my way around the codebase/understanding the edges stuff so I thought I'd mess around more with the playground.

Is there a discord or community somewhere?

[obi1kenobi]

Thank you for the kind words 😊 What kinds of stuff are you looking to automate, any examples you don't mind sharing?

I'm looking into setting up a Discord, I'm just worried about spam and such (e.g. what happened to the Rust Community Discord) and it'll be another month or so before I can really dig into the moderation tools enough to feel comfortable making a community server.

In the meantime, I'm in several Rust / systems-themed Discords, so perhaps you can find me there? I'm also on Twitter, Mastodon, and Bluesky, and obviously here in the Discussions tab.

I look forward to seeing what you build! Please post them as show-and-tell items here in Discussions :) And if anything isn't clear in the docs, or in the code, or just in general with the project, please feel free to ask questions and I'll do my best to answer.

[u9g]

I'm in college now, so I have to look for new classes each semester. I'd love to be able to crosscheck classes I need with ratemyprofessor grade for the professor in a composable way. Although, to be honest I am just having fun in general adding sources at the moment to the example, as this project is blowing up what I thought was possible with coding.

That's completely understandable, I've added you on discord so I may ask some things over there in the future, and am super excited to build stuff, thanks for making this open source and being so helpful!

[obi1kenobi]

Awesome! That's exactly the sort of use case Trustfall is meant for: cases where you "technically have the data" and yet without Trustfall, the next best option would be either a completely bespoke one-off script or just doing it all manually by clicking around a bunch.

I'm happy to help, and I'd be thrilled to see what you build — please do share screenshots, experiences, queries, anything you deem interesting to point out!