Trustfall: How to Query (Almost) Everything
Trustfall author here, pleasantly surprised to find this posted!The goal of Trustfall is to be the LLVM of data sources. GraphQL, OpenAPI, JSON (with JSON schema or not), SQL, RDF/SPARQL -- and none of them can natively talk to each other. Sure, you can stick JSON into Postgres, or compile GraphQL to SQL -- I've done both in production and it's always ultimately a poor fit because you're cramming one system into another when it was never originally designed to support that.Here's an example: tell me the GitHub or Twitter accounts of HN users that have commented on HN stories about OpenAI. The data is available from the HN APIs on Firebase (for item lookup) and Algolia (for search). I know all of us could write a script to do it -- but would we? Or is it too annoying and difficult, and not worth it? That "activation energy" barrier is something I want to eliminate. Here's that same query in the Trustfall Playground, where it took just a minute or two to put together: https://play.predr.ag/hackernews#?f=1&q=IyBDcm9zcyBBUEkgcXVl...Trustfall is designed for interoperation from day 1. It separates the queries from the data providers, allowing the infrastructure to evolve and change how it serves queries without any of the queries noticing anything except faster execution. In practice, that means you don't have to rewrite your product to make it run faster -- which makes both the product side and the infra side happier :)Here's a real-world example of that. The `cargo-semver-checks` Rust semantic versioning linter implements its lints as Trustfall queries over JSON files describing the package API, and I recently was able to speed up its execution by over 2000x without changing a single query -- just by changing how those queries execute under the hood. More details in my blog post here: https://predr.ag/blog/speeding-up-rust-semver-checking-by-ov...AMA, I guess :)