The proposed `remove` here is actually in-place. And this really is not unlike this proposal of mine [1], which is also in place.
The reason it belongs in the standard library is because you can optimize it *way* better using vector instructions and it's among one of the most common cases for `.filter` - how often have you done `array.filter(x => x !== value)`? With my `Array.prototype.delete`, you could do `array.slice().delete(value, true)` for practically the same thing (it's 3 extra characters), just done a bit faster thanks to not needing the overhead. - For deleting a single value* from a dense array, you could optimize it much like `array.indexOf` followed by `array.copyWithin` + `array.length -= 1` if the value exists. - For deleting multiple values* from a dense array, you'd do it similarly, just you'd keep a separate offset that you'd increment on each hit, subtracting that for the stores. - In each case, your search would be a mix of SIMD with horizontal reductions, things most modern processors make easy. * With a few exceptions, of course. Doubles in V8 and 32-bit SpiderMonkey are one of them, since they are boxed and compared by their contents. Multi-character strings are another big exception. The reason I called mine `delete` instead of `remove` is to align with `Set.prototype.delete` and `Map.prototype.delete`, which operate similarly. [1]: https://github.com/isiahmeadows/es-stdlib-proposals/blob/master/proposals/array/delete.md ----- Isiah Meadows cont...@isiahmeadows.com www.isiahmeadows.com On Mon, Feb 4, 2019 at 1:40 AM Jordan Harband <ljh...@gmail.com> wrote: > > Why "remove" and not `.filter`, to produce a new array? > > On Sun, Feb 3, 2019 at 9:56 PM #!/JoePea <j...@trusktr.io> wrote: >> >> I sometimes find myself doing things like >> >> ```js >> this.children.splice(this.children.indexOf(child), 1) >> ``` >> >> but it seems that it will iterate the array twice. Maybe a new method can be >> introduced so engines can optimize it: >> >> ```js >> this.children.remove(child) >> // or >> this.children.remove(...childrenToRemove) >> ``` >> _______________________________________________ >> es-discuss mailing list >> es-discuss@mozilla.org >> https://mail.mozilla.org/listinfo/es-discuss > > _______________________________________________ > es-discuss mailing list > es-discuss@mozilla.org > https://mail.mozilla.org/listinfo/es-discuss _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
