On Wed, Feb 17, 2016 at 10:51 AM, Andreas Rossberg <[email protected]> wrote:
> On 17 February 2016 at 09:40, Benjamin Gruenbaum <[email protected]> > wrote: > >> If you starve a generator it's not going to get completed, just like >>> other control flow won't. >>> >> >> I'm not sure starving is what I'd use here - I definitely do see users do >> a pattern similar to: >> >> ```js >> function getResults*() { >> try { >> var resource = acquire(); >> for(const item of resource) yield process(item); >> } finally { >> release(resource); >> } >> } >> ``` >> > > Yes, exactly the kind of pattern I was referring to as "bogus forms of > resource management". This is an anti-pattern in ES6. It won't work > correctly. We should never have given the illusion that it does. > What is or is not an anti-pattern is debatable. Technically if you call `.return` it will run the finally block and release the resources (although if the finally block itself contains `yield` those will also run). Effectively, this will have the same sort of consequences that "acquire()" and "release()" had to begin with - so I would not say it makes things worse but I definitely agree that it creates a form of false expectation. Still - I'm very curious why languages like Python have chosen to call `finally` blocks in this case - this was not a hindsight and according to the PEP. They debated it and explicitly decided to call `release`. I'll see if I can email the people involved and ask about it. > garbage collection is a form of automatic resource management. > > > Most GC experts would strongly disagree, if by resource you mean anything > else but memory. > Memory is most certainly a resource. Languages that are not GCd like C++ really don't make the distinction we make :) Garbage collection can and does in fact manage resources in JavaScript host environments right now. For example, an XMLHttpRequest *may *abort the underlying HTTP request if the XMLHttpObject is not referenced anywhere and gets garbage collected.
_______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
