Yeah, if you treat it as javascript vs python they're likely correct (I'm not that familiar with js). The article and original comment were about function vs imperative though, so I assumed half decent runtimes for both.

It's not? How could that possibly work when the lambda could throw and it could throw on the nth invocation and your stack trace has to be correct?

If I run this in the JS console I get two anonymous stack frames. The first being the console itself.

    [1, 2, 3].filter(x => [][0]())

True, but now you're relying on a specific implementation and optimization of the compiler, unless the language semantics explicitly say that lambdas will be inlined.