I was going to mention C#'s using statement as well... though I do like the use of a symbol over Ron's proposal, I think using might be a better approach.
-- Michael J. Ryan 480-270-4509 https://www.tracker1.info/ [email protected] [email protected] On Mon, Oct 15, 2018 at 11:50 AM Till Schneidereit < [email protected]> wrote: > Ron Buckton has a proposal that's quite similar to what you're talking > about: https://github.com/tc39/proposal-using-statement > > On Mon, Oct 15, 2018 at 11:40 AM Dan Aprahamian <[email protected]> > wrote: > >> Hello all! First time posting here. I was curious if there was ever talk >> about adding something similar to python's with syntax to JS. Obviously we >> already have a "with" keyword, but I figure we could probably use "use" as >> the keyword instead. I was thinking something like >> >> // Some user defined resource that can be "entered" and "exited" >> class MyResource { >> // Function called when entered >> async [Symbol.enter]() { >> } >> >> // Function called when exited >> [Symbol.exit]() { >> } >> } >> >> const resource = new MyResource(); >> >> async function useResource() { >> use myResource { >> // Inside here, resource has had "acquire" called on it >> >> await doSomethingAsync(); >> // Once this block is finished executing (including async) >> // release is called >> } >> // Release has been called now >> } >> >> Use would effectively be the equivalent of: >> >> async function use(resource, body) { >> await resource[Symbol.enter](); >> try { >> await body(); >> } finally { >> await resource[Symbol.exit](); >> } >> } >> >> Has something like this been considered before? >> >> Thanks, >> Dan >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss >
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