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Comment by gsnedders | Hacker News Reader

How can you fix the global scope without breaking almost all existing JS code? Browsers will never ship anything that breaks large numbers of existing websites (users don't use browsers that don't work with the web!).

Adding an integer type is far easier said than done. It was decided to leave that hard problem to ES7; integer type (or types!) are certainly coming.

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>> How can you fix [X] without breaking almost all existing [Y] code?

For most cases of X, some form of declaration that is scope bound.

Look at e.g. Perl, it changes quickly in this way, with very good backwards compatibility. [Also see strict mode, of course.]

Edit: That said, new keywords like those let/const/module/extends etc should work fine. Please give me them today.

Edit 2: I have been cursing the lack of multiple returns this week. It is a pain returning a hash/object or an array. That really isn't supported, from browsing the standard? :-(

> Edit 2: I have been cursing the lack of multiple returns this week. It is a pain returning a hash/object or an array.

Why is that?

  let rational = (a, b) => [a, b];
  let [numerator, denominator] = rational(38, 4);
  let reduced = rational(numerator/2, denominator/2);

PS. The above code works in stable Firefox.

>> Why is that?

<Cough> Obviously because I'm blind? :-) Thanks.

There's an unwillingness to introduce too many opt-ins into JS as it quickly leads to ever increasing implementation complexity. Note that Perl is one of the few notable languages to have such sort of opt-ins.

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