We can play with Glean using the shell. You can do this directly from the Docker image if you want, or Build Glean from source first.
To try experiments we can work with a local schema definition and local database (as opposed to connecting to a Glean server). If you want to play along with the examples, you can do so as follows:
glean shell --db-root /tmp/glean/db --schema /tmp/glean/schema
Put the example
/tmp/glean/schema/example.angle and the example
/tmp/glean/facts.glean. Then reload schema and create a database from the example
:load <file> in the shell:
reloading schema [2 schemas, 7 predicates]
> :load /tmp/glean/facts.glean
Now head over to Angle Guide to try some example queries and learn about how the query language works.