An executable specification will be developed alongside Reia
itself. This specification will be self-hosted, to the point that
alternative implementations of the core language should be able to
run the testing tool and with it self-hosted tests for various
language behaviors.
This specification will simultaneously provide written
descriptions of how the language should behave, automated testing
for regressions when the standard implementation changes, and allow
for third-party Reia implementations to test if they're providing
the correct behaviors.