Use ES2015 destructuring assignment to swap variables #4674
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This commit uses ES2015 destructuring assignment to swap two variables instead of using a tmp var. Flow has an open issue (facebook/flow#183) with this feature, though, so // $FlowFixMe is used to temporarily suppress the error.
| this.deps = this.newDeps | ||
| this.newDeps = tmp | ||
| // $FlowFixMe | ||
| [this.depIds, this.newDepIds] = [this.newDepIds, this.depIds] |
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Maybe leading semicolon is better for []? Since the change is packed in one line so it is harder for one to forget adding semicolon.
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If they forget, the lint/test process will certainly remind them, right?
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Checked the output in Buble and it uses an intermediate Array for the purpose: https://buble.surge.sh/#%5Bthis.depIds%2C%20this.newDepIds%5D%20%3D%20%5Bthis.newDepIds%2C%20this.depIds%5D - which leads to more allocation than necessary - and this part is pretty perf-sensitive. P.S. personally I'm not really a fan of this syntax's readability :/ |
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Oh damn! Well, the more you know...
…On Friday, January 13, 2017, Evan You ***@***.***> wrote:
Closed #4674 <#4674>.
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This commit uses ES2015 destructuring assignment to swap two variables instead of using a
tmpvar. Flow has an open issue (facebook/flow#183) with this feature, though, so// $FlowFixMeis used to temporarily suppress the error.