[alkonaut]

I still don't understand that. Function.prototype.toString() wouldn't break because the parser stripped the comments, it would just output the source without comments? Does any code anywhere depend on the comments being preserved?

[spullara]

People literally toString functions and parse them to implement features. Those features depend on there being comment text in the function that they parse. Pretty much a terrible hack but it is true that you can't remove the comments without breaking current code.

[alkonaut]

Wow. That's just something that should be an obvious fix in a future ES. Not only does it hurt the optimizer, it also seems to imply that the content of comments sometimes has semantic meaning in the code, such as people having invented directives etc.

Surely this must be undocumented features of the language spec?