Microsoft/TypeScript

Unoptimized destructuring compilation

Aperta

#11.779 aperta il 21 ott 2016

 (6 commenti) (1 reazione) (0 assegnatari)TypeScript (13.395 fork)batch import
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Descrizione

TypeScript Version: 2.0

Code

// source ts code
let i = 1000;
while (i--) {
  let [a, b, c] = [1, 2, 3];
}

Expected behavior:

// compiled by babel
var i = 1000;
while (i--) {
  var a = 1;
  var b = 2;
  var c = 3;
}

Actual behavior:

// compiled by tsc
var i = 1000;
while (i--) {
    var _a = [1, 2, 3], a = _a[0], b = _a[1], c = _a[2];
}

On each iteration tsc creates new unnecessary array _a.

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