Augmenting Number.prototype with the functions from Math

Allen Wirfs-Brock allen at wirfs-brock.com
Wed Jan 25 16:40:48 PST 2012


On Jan 25, 2012, at 3:47 PM, Andrea Giammarchi wrote:

> Number.prototype.pow = function pow(radix) {
>   return Math.pow(this, radix);
> };
> 
> //alert(2.pow(3)); // error, decimal point, not property accessor
> alert(2..pow(3));  // 8
> alert(NaN.pow(0)); // 1

The last case is strictly in conformance with IEEE 754.  See http://en.wikipedia.org/wiki/NaN#Quiet_NaN (and in particular, the "Function definition" section) for an explanation.

Allen


> 
> until numbers are valid as digit. I don't see any advance on using Number.prototype for anything
> until NaN is not instanceof Number but NaN.__proto__ is === Number.prototype, I don't see methods useful in the Number.prototype
> 
> Last, but not least, I agree these are easy to implement through pure JS, no need to specs this stuff or make it native ( since after last 2 points I don't see common use cases in any case for polluted Number.prototype )
> 
> my 2 cents,
> br
> 
> On Wed, Jan 25, 2012 at 8:53 PM, Xavier MONTILLET <xavierm02.net at gmail.com> wrote:
> About Object.method vs Object.prototype.method, I think it's something
> they adopted for *objects* because on objects, if you put these
> methods on the prototype, they might get shadowed. But since I'm
> talking about numbers, there is no such problem.
> 
> And I know I can make polyfills but I'd prefer to have it in the
> language itself because I'd be sure to have the same API in every
> environment and I wouldn't have to have a polyfill I have to include
> every single time. Plus I think this is generic enough to be part of
> core.
> 
> On Wed, Jan 25, 2012 at 8:36 PM, Jussi Kalliokoski
> <jussi.kalliokoski at gmail.com> wrote:
> > You can get emulate that kind of a feature quite simply in ES5+ (and
> > earlier, if you have enough polyfills, or make compromises) if you like it,
> > see https://gist.github.com/1678065 .
> >
> > Cheers,
> > Jussi
> >
> >
> > On Wed, Jan 25, 2012 at 8:49 PM, Herby Vojčík <herby at mailbox.sk> wrote:
> >>
> >> I see more a "cultural" question here. There are lots of functions in ES
> >> which would make perfect (and probably better) sense if called on object
> >> than from outside (definePrototype & Co., maybe even isArray), but it is
> >> probably seen more "Javascriptic" to put them statically into Object,
> >> Number, Array, whatever.
> >>
> >> I think it has something with feeling they should not be dynamic part of
> >> object's contract, but on the contrary, they should be "decoupled" into safe
> >> managerial havens of Object, Array etc.
> >>
> >> But I can't say for sure.
> >>
> >> As I see it, in ES this is the way. Even if I don't like it, and it seems
> >> to me cumbersome to always do Object.fooBarBazAndMore(x, ...), I accept it
> >> as "Javascriptic" way to go.
> >>
> >> Moving just pow would create more confusion, I think. Moving more would
> >> also create lot of confusion (in actual state, only hasOwnProperty is the
> >> case which seems to not align with this way, being in Object.prototype; and
> >> you often see code like var hasOwn = Object.prototype.hasOwnProperty; or
> >> even var hasOwn =
> >> Function.prototype.call.bind(Object.prototype.hasOwnProperty) just to bring
> >> it back to "external actors" domain).
> >>
> >> Herby
> >>
> >>
> >> Xavier MONTILLET wrote:
> >>>
> >>> Hi,
> >>>
> >>> I think it'd be nice to have the functions available in Math in
> >>> Number.prototype.
> >>> e.g.
> >>>
> >>> Number.prototype.pow = function ( p ) {
> >>>     return Math.pow( this, p );
> >>> };
> >>>
> >>> Since pow is supposed to be an operator, I feel better when writing
> >>> a.pow( b ) than Math.pow( a, b );
> >>>
> >>> About the other methods, I'm not sure. They really are "functions" in
> >>> maths so it doesn't feel that weird calling them with Math.f( ).
> >>> Moreover if you store them in local variables.
> >>> But I still find doing a.abs( ).ceil( ) is way more convenient than
> >>> Math.ceil( Math.abs( a ) ).
> >>>
> >>> So since numbers are litterals and therefore extending the prototype
> >>> won't break anything, why not add it?
> >>> _______________________________________________
> >>> es-discuss mailing list
> >>> es-discuss at mozilla.org
> >>> https://mail.mozilla.org/listinfo/es-discuss
> >>
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> >
> >
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