Consider an API like this:

[CEReactions]
void foo(long arg);

A call to foo would normally consist of two things:

1. Coercing the first arg to long.
2. Whatever the actual work is that foo does.

Is "the algorithm" for purposes of https://html.spec.whatwg.org/multipage/scripting.html#cereactions both 1 and 2, or just 2? Or does it not matter in practice? I haven't really wrapped my head around the custom element reactions stuff yet to tell whether it matters....

@domenic @annevk