Tutorials

Learn jaala's query language by asking questions about a small Go service: what it imports, what's tested, who owns what.

These tutorials teach jaala’s query language one idea at a time, all against the same small fact set, deps, a Go-style service with ten packages, what each one imports, its tests, which team owns each package, and how many lines each has. Every example on these pages runs on jaala when the site is built, so the answers you see are the engine’s.

  1. A first query covers facts, goals and variables, and the order answers come back in.
  2. Rules and recursion derives new relations and follows imports all the way down.
  3. Negation asks what isn’t there, and explains the two rules that keep that well defined.
  4. Aggregation counts, sums and lists, in the answer and in a rule.
  5. Embedding jaala in Go serves facts from Go and runs the same queries from a program.

The facts ΒΆ

The datasets page shows every relation of deps as a table, with the facts as written. cache and config import each other on purpose, because the second tutorial needs a cycle.