Re: Why Number(symbol) crashes?

> On Oct 14, 2016, at 11:02 AM, Claude Pache wrote: > > >> Le 11 oct. 2016 à 11:07, medikoo a écrit : >> >> I was searching the archived but wasn't able to find the answer. >> >> What's the reasoning behind having Number(symbol) crash

User-defined literals

I haven't seen this discussed on ESDiscuss before. For those not familiar with user-defined literals: Essentially, they allow certain literals (e.g. 123.45, "hello") to produce a user-defined object by marking the literal with a user-defined suffix. They were introduced in C++11 [1], and I'm

Re: Why Number(symbol) crashes?

> Le 11 oct. 2016 à 11:07, medikoo a écrit : > > I was searching the archived but wasn't able to find the answer. > > What's the reasoning behind having Number(symbol) crash instead of returning > NaN (as it's in case all other non-coercible values?). It feels

Re: Try/Catch always needed for await?

Just one thought: > Of course, in the top-level invocation it might be a good idea to use a `catch` after years of engine developers advocating "avoid try/catch as much as possible because it de-opts and slow down code and JIT and you name it", above suggestion doesn't really look like an "of

Re: Try/Catch always needed for await?

To perhaps clarify this point a bit, it is very important to `.catch()` and react appropriately at the ends of promise chains. If synchronous code fails for an unexpected reason, a visible crash will definitely happen. This is not the case for promises, because there’s no way for the runtime to

Re: Power operator, why does -2**3 throws?

> Le 14 oct. 2016 à 16:52, Rick Waldron a écrit : > > Python is also inconsistent: > > >>> pow(-2, 2) > 4 > >>> -2 ** 2 > -4 > >>> This is not inconsistency, but that follows from operator precedence rules (those used in mathematics, not in C). In the same vein, you

Re: Power operator, why does -2**3 throws?

Here's some more specific notes: On Fri, Oct 14, 2016 at 7:31 AM Cyril Auburtin wrote: > I would expect `-2**3` to return -8, or `-2**2 == -4`, since it should be > like `-(2**3)` > Math.pow(-2, 3) === -8 Math.pow(-2, 2) === 4 To get -4: -Math.pow(-2, 2) > Firefox

Re: Power operator, why does -2**3 throws?

On Fri, Oct 14, 2016 at 7:31 AM Cyril Auburtin wrote: > I would expect `-2**3` to return -8, or `-2**2 == -4`, since it should be > like `-(2**3)` > This was discussed extensively during the design process and determined that requiring user code to be explicit about

Re: Making Object Literals a sub-class of Object

On Fri, Oct 14, 2016 at 9:05 AM Brian Ninni wrote: > I did a quick search and didn't find any recent mentions of this topic. > > On more than one occasion I've had to determine whether something was a > plain old Object, or some other class. This involves checking that the

Re: Making Object Literals a sub-class of Object

Object literals (object initializers) are just a convenient way to create a new ordinary object which (initially) inherits from `Object.prototype`, and populate it with some properties. I don't think you should be able to distinguish them from similar objects not created using object

Re: Making Object Literals a sub-class of Object

> > `({}).toString.call(o);` This does work for all Native class, but still returns "[object Object] " for user created classes `Object.getPrototypeOf({}) === Object.prototype // true` Did not know of that method. Seems like a roundabout way, but it works.

Re: Making Object Literals a sub-class of Object

I wrote: Brian Ninni wrote: On more than one occasion I've had to determine whether something was a plain old Object, or some other class. This involves checking that the given object was NOT an instanceof any other acceptable class. `Object.prototype.isPrototypeOf(o)` should do that (if you

Re: Try/Catch always needed for await?

Jordan Rome schrieb: My apologies if this has already been discussed but what is the "preferred" pattern for using await ? Since await, which runs on promises, will now throw if the promise is rejected (preventing execution of code after the await and killing the process in Node), is it

Re: Making Object Literals a sub-class of Object

Brian Ninni wrote: On more than one occasion I've had to determine whether something was a plain old Object, or some other class. This involves checking that the given object was NOT an instanceof any other acceptable class. `Object.prototype.isPrototypeOf(o)` should do that (if you don't

Re: Making Object Literals a sub-class of Object

If you want to check that your variable is a plain old object and not some other class, you can use `Object.getPrototypeOf(x) === Object.prototype` `Object.getPrototypeOf({}) === Object.prototype // true` `Object.getPrototypeOf(new Map()) === Object.prototype // false` Le ven. 14 oct. 2016 à

Re: Making Object Literals a sub-class of Object

2016-10-14 15:05 GMT+02:00 Brian Ninni : > I did a quick search and didn't find any recent mentions of this topic. > > On more than one occasion I've had to determine whether something was a > plain old Object, or some other class. This involves checking that the > given

Making Object Literals a sub-class of Object

I did a quick search and didn't find any recent mentions of this topic. On more than one occasion I've had to determine whether something was a plain old Object, or some other class. This involves checking that the given object was NOT an instanceof any other acceptable class. Array, RegExp,

Re: Power operator, why does -2**3 throws?

I was testing something https://caub.github.io/misc/calculator, and I didn't see how it would be a problem to have the precedence of ** higher than unaries. But at least I'm happy something like (2).pow(3) wasn't chosen. Thanks anyway and sorry for discussing something already frozen in spec

Re: Power operator, why does -2**3 throws?

Ah, ok, a bit sad because all more scientific languages, and python too, all math books, all will use `-e^3` for meaning `-(e^3)` (^ or **), because it's just `-exp(3)` or `-pow(E, 3)` and `(-1)^n` otherwise, when we want to take the signs with. If you wanted to avoid any confusion you could

Re: Power operator, why does -2**3 throws?

Cyril Auburtin schrieb: I would expect `-2**3` to return -8, or `-2**2 == -4`, since it should be like `-(2**3)` You would, others would not. -2 ** 2 clearly should return 4, shouldn't it? Is there a reason for this restriction? Python does it `-2**3` fine Because of the ambiguity it has

Re: Power operator, why does -2**3 throws?

What does it change if it handles floats? I just checked https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence unary + is 16, while exponentiation is 15, so the opposite order that I thought 2016-10-14 13:37 GMT+02:00 J Decker : >

Re: Power operator, why does -2**3 throws?

probably because it's floating point native not integer like you'd think, so -2.0001 ** 3 is hard? On Fri, Oct 14, 2016 at 4:30 AM, Cyril Auburtin wrote: > I would expect `-2**3` to return -8, or `-2**2 == -4`, since it should be > like `-(2**3)` > > Firefox gives

Power operator, why does -2**3 throws?

I would expect `-2**3` to return -8, or `-2**2 == -4`, since it should be like `-(2**3)` Firefox gives a clearer error then Chrome with: > SyntaxError: unparenthesized unary expression can't appear on the left-hand side of '**' Is there a reason for this restriction? Python does it `-2**3` fine