2012/12/14 Allen Wirfs-Brock al...@wirfs-brock.com
BTW, I think there are probably other related issues that need to be
discussed/resolved at that level. For example, is SameValue really want we
want for Map/Set equivalence (the -0 different from +0 issue), did we agree
to parameterize the
On 14 December 2012 16:39, Allen Wirfs-Brock al...@wirfs-brock.com wrote:
No, the whole point of Number.isNaN is to provide a definitively test for
NaN number values which cannot be tested for in the usual way using ===.
The definitiveness of the test would be lost if other values such a
Le 18/12/2012 14:43, gaz Heyes a écrit :
On 14 December 2012 16:39, Allen Wirfs-Brock al...@wirfs-brock.com
mailto:al...@wirfs-brock.com wrote:
No, the whole point of Number.isNaN is to provide a definitively
test for NaN number values which cannot be tested for in the
usual way
On Fri, Dec 14, 2012 at 2:43 AM, Andreas Rossberg rossb...@google.com wrote:
On 14 December 2012 06:46, John-David Dalton
john.david.dal...@gmail.com wrote:
Axel Rauschmayer:
Honest question: I have yet to see boxed values in practice. Are there any
real use cases?
See Modernizr:
No, the whole point of Number.isNaN is to provide a definitively test for NaN
number values which cannot be tested for in the usual way using ===. The
definitiveness of the test would be lost if other values such a Number wrapper
instance also returned true when passed as the argument for
No, the whole point of Number.isNaN is to provide a definitively test
for NaN number values which cannot be tested for in the usual way using
===.
Wat? This seems to be a good reason to allow `Object(NaN)` and use the
NumberWrapper brand as it cannot be tested via the normal way of `myNaN
Wat? This seems to be a good reason to allow `Object(NaN)` and use the
NumberWrapper brand as it cannot be tested via the normal way of
`myNaN !== myNaN`.
But `myNaN === myNaN` is true if `myNaN = Object(NaN)`. Testing against the
object is different. Nothing breaks.
var myNaN =
But `myNaN === myNaN` is true if `myNaN = Object(NaN)`.
That's my point. Normally testing for NaN can be done via `myNaN !== myNaN`
but `Object(NaN)` throws a wrench in that.
It would be great if there was 1 function that was able to detect NaN,
instead of having libs step up and do it.
-JDD
EcmaScript koan:
NaN is NotANumber.
NaN is a number.
Object(NaN) is not a number.
Thus, Object(NaN) isn't NotANumber.
On Fri, Dec 14, 2012 at 9:22 AM, John-David Dalton
john.david.dal...@gmail.com wrote:
But `myNaN === myNaN` is true if `myNaN = Object(NaN)`.
That's my point. Normally
That is deep.
On Friday, December 14, 2012, Mark S. Miller wrote:
EcmaScript koan:
NaN is NotANumber.
NaN is a number.
Object(NaN) is not a number.
Thus, Object(NaN) isn't NotANumber.
___
es-discuss mailing list
es-discuss@mozilla.org
John-David Dalton wrote:
But `myNaN === myNaN` is true if `myNaN = Object(NaN)`.
That's my point. Normally testing for NaN can be done via `myNaN !==
myNaN` but `Object(NaN)` throws a wrench in that.
It would be great if there was 1 function that was able to detect NaN,
instead of having
From: es-discuss-boun...@mozilla.org [es-discuss-boun...@mozilla.org] on
behalf of Nathan Wall [nathan.w...@live.com]
Sent: Friday, December 14, 2012 13:34
On another note, I do sort of wonder why `Number.isNaN` is coming into the
language now at the same time as the `is` operator and
Bendan Eich wrote:
Your modernizr true-wrapping Boolean example is both a WTFJS moment,
easily avoided by using a truthy object as Sam pointed out, and nothing to
do with NaN.
The Modernizr example was in response to Axel's request for an example of
boxed values being used in real world
On another note, I do sort of wonder why `Number.isNaN` is coming into the
language now at the same time as the `is` operator and `Object.is`. It
seems teaching people (and getting them to remember long-term) the nuances
of `isNaN` and `Number.isNaN` will be more difficult than just
On Dec 14, 2012, at 10:45 AM, Domenic Denicola wrote:
From: es-discuss-boun...@mozilla.org [es-discuss-boun...@mozilla.org] on
behalf of Nathan Wall [nathan.w...@live.com]
Sent: Friday, December 14, 2012 13:34
On another note, I do sort of wonder why `Number.isNaN` is coming into the
Speaking of SameValue, it's unnecessary in many/most of the places it's
used in the spec. Like in IsEquivelentDescriptor the only comparison that
needs to use SameValue is comparing the [[Value]] field.
On Fri, Dec 14, 2012 at 2:02 PM, Allen Wirfs-Brock al...@wirfs-brock.comwrote:
On Dec 14,
Domenic Denicola wrote:
From: es-discuss-boun...@mozilla.org [es-discuss-boun...@mozilla.org] on behalf
of Nathan Wall [nathan.w...@live.com]
Sent: Friday, December 14, 2012 13:34
On another note, I do sort of wonder why `Number.isNaN` is coming into the
language now at the same time as the
I apologize for the duplicate post, but I think my reply got lost in its
formatting.
The Modernizr example was in response to Axel's request for an example of
boxed values being used in real world projects.
Popular libs like jQuery, Dojo, MooTools, Prototype, and Underscore have
`isXyz` methods
This boxed-primitive equation is a sore point, and perhaps some API
should be standardized, but Number.isNaN is not that API. That's point
#1, please ack it: we must have a predicate that applies only to true
NaN primitives.
Point #2 is that we haven't heard the demand for such APIs until
On Fri, Dec 14, 2012 at 2:02 PM, Allen Wirfs-Brock al...@wirfs-brock.comwrote:
On Dec 14, 2012, at 10:45 AM, Domenic Denicola wrote:
From: es-discuss-boun...@mozilla.org [es-discuss-boun...@mozilla.org] on
behalf of Nathan Wall [nathan.w...@live.com]
Sent: Friday, December 14, 2012 13:34
From: es-discuss-boun...@mozilla.org [mailto:es-discuss-boun...@mozilla.org]
On Behalf Of John-David Dalton
Subject: Number.isNaN
I noticed that ES6 `Number.isNaN` checks `Type(number)` of Number, would it
make sense to instead check that the [[BuiltinBrand]] is
BuiltinNumberWrapper
On Thu, Dec 13, 2012 at 7:50 PM, Luke Hoban lu...@microsoft.com wrote:
From: es-discuss-boun...@mozilla.org
[mailto:es-discuss-boun...@mozilla.org] On Behalf Of John-David Dalton
Subject: Number.isNaN
I noticed that ES6 `Number.isNaN` checks `Type(number)` of Number, would
it make sense
The current draft spec [0] uses a ToNumber coercion and checks whether
this results is NaN. So Number.isNaN(Object(NaN)) will return true.
Global's isNaN uses ToNumber, but Number.isNaN doesn't do it because type
coercion makes confused result, such as `isNaN(Object(NaN))` = true [0]
So
From: Mark S. Miller [mailto:erig...@google.com]
In that case, the current spec is wrong. The purpose of introducing
Number.isNaN is to repair the following bug in the global isNaN:
isNaN(foo) // returns true
Indeed, as Yusuke noted on the other reply, I referred to the wrong
Yap yap, so thoughts on `BuiltinNumberWrapper` instead of `Type(…)`? It
would still prevent the global `isNaN('foo')` confusion. Though
`Object.is(NaN, Object(NaN))` currently returns `false` too. Was this just
an oversight? I know `Object(NaN)` is totally edge case but it still has
the brand of
Honest question: I have yet to see boxed values in practice. Are there any real
use cases?
[[[Sent from a mobile device. Please forgive brevity and typos.]]]
Dr. Axel Rauschmayer
a...@rauschma.de
Home: http://rauschma.de
Blog: http://2ality.com
On 14.12.2012, at 05:18, Luke Hoban
On Thu, Dec 13, 2012 at 8:25 PM, John-David Dalton
john.david.dal...@gmail.com wrote:
Yap yap, so thoughts on `BuiltinNumberWrapper` instead of `Type(…)`? It
would still prevent the global `isNaN('foo')` confusion. Though
`Object.is(NaN, Object(NaN))` currently returns `false` too. Was this
No. Object.is correctly reports that these are different.
Ah yap, I've had my head in lib code for a while. I'm used to the behavior
of `_.isEqual(3, Object(3)); // = true`
but you're right the current behavior of `Object.is(3, Object(3)); //
false` so yap it makes sense that it's that way for
Honest question: I have yet to see boxed values in practice. Are there
any real use cases?
See Modernizr:
https://github.com/Modernizr/Modernizr/blob/master/feature-detects/video.js#L23
-JDD
On Thu, Dec 13, 2012 at 8:26 PM, Axel Rauschmayer a...@rauschma.de wrote:
Honest question: I have
On 14 December 2012 06:46, John-David Dalton
john.david.dal...@gmail.com wrote:
Axel Rauschmayer:
Honest question: I have yet to see boxed values in practice. Are there any
real use cases?
See Modernizr:
https://github.com/Modernizr/Modernizr/blob/master/feature-detects/video.js#L23
I think
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