Creates the evaluator registered under a name or alias. The highest-priority registration wins,
so a host can replace a built-in by registering its own class under the same name.
Throws, listing the registered names, when nothing is registered under it.
Creates the evaluator registered under a name or alias. The highest-priority registration wins, so a host can replace a built-in by registering its own class under the same name. Throws, listing the registered names, when nothing is registered under it.