guest271314 at gmail.com (2019-06-28T01:16:48.824Z)
> then the proposal is `array.find(.requestFrame)`. > > Since `.prop` is defined to be identically semantically to `o => o.prop`, yes, the function `.prop` applied to an object with no property named `prop` returns `undefined`. Has the opposite, ```!``` and ```!!``` preceding ```.prop```, ```const d = [a, b].find(!.c);``` or ```const d = [a, b].find(!(.c));``` been considered? And ```async``` functions ```const d = [a, b].find(async(await(.c)));```?
guest271314 at gmail.com (2019-06-28T01:16:14.636Z)
> then the proposal is `array.find(.requestFrame)`. > > Since `.prop` is defined to be identically semantically to `o => o.prop`, yes, the function `.prop` applied to an object with no property named `prop` returns `undefined`. Has the opposite, ```!``` and ```!!``` preceding ```.prop```, ```const d = [a, b].find(!.c);``` or ```const d = [a, b].find(!(.c));``` been considered? And ```async``` functions ```const d = [a, b].find(async (await(.c)));```?
> then the proposal is `array.find(.requestFrame)`. > > Since `.prop` is defined to be identically semantically to `o => o.prop`, yes, the function `.prop` applied to an object with no property named `prop` returns `undefined`. Has the opposite, ```!``` and ```!!``` preceding ```.prop```, ```const d = [a, b].find(!.c);``` or ```const d = [a, b].find(!(.c));``` been considered? And ```async``` functions ```const d = [a, b].find(async (await(.c)));```? On Fri, Jun 28, 2019 at 12:48 AM Bob Myers <rtm at gol.com> wrote: > If the intent is to find the first entry with a truthy value for the > `requestFrame` property, then the proposal is `array.find(.requestFrame)`. > If the "wildcard" syntax is used, then it would be > `array.find(?.requestFrame)`. > > On Thu, Jun 27, 2019 at 5:30 PM guest271314 <guest271314 at gmail.com> wrote: > >> How can the Selector/Select Expression be used with >> `Array.prototype.find()`? What happens when the property is not defined? >> >> For example using the same code for more than one browser >> >> ``` >> const stream = [canvasStream, videoTrack].find(({requestFrame: _}) => _); >> ``` >> >> the property `requestFrame` is either defined or not defined at >> ```canvasStream``` or ```videoTrack``` depending on the implementation. >> Although the assigned variable can be reduced to 1 character at >> destructuring assignment, there is still the redundancy of writing ```_``` >> again on the right side of ```=>```. >> >> If the property is not found, is the result ```undefined```? >> > > Since `.prop` is defined to be identically semantically to `o => o.prop`, > yes, the function `.prop` applied to an object with no property named > `prop` returns `undefined`. > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.mozilla.org/pipermail/es-discuss/attachments/20190628/14a6e9f4/attachment.html>