[notnullorvoid]

Macros don't really make sense in JS runtime spec. Since you can mostly already achieve macro level features by using eval or new Function, but it's not very efficient. Macros make most sense at build time, and there have been a few attempts at generalized build macros with various bundlers / transpiler plugins. I think the space needs more time to mature. I'm optimistic that we'll eventually see some sort of (un)official macro spec emerge.