This is an implementation of Specter's core features without any of the optimizations. This is intended as a reference to understand the basics of how Specter works. As you can see from the library, the core of Specter is only about 30 lines of code. Most of the full Specter implementation is optimizations to make it fast.
Most of Specter's selectors are not included in this reference. Also, this does not implement value collection or precompilation.