Math ugliness.
in [JavaScript]
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From: Jorge on 16 Feb 2010 18:23 Hi, Do you think -as I do- that the Math object is an ugly artifact ? Well, here's a nice way of getting rid of it : Number.prototype.sin= function () { return Math.sin(+this); }; Number.prototype.asin= function () { return Math.asin(+this); }; Number.prototype.pow= function (p) { return Math.pow(+this, p); }; Number.prototype.sqrt= function () { return Math.sqrt(+this); }; Number.prototype.rnd= function () { return this*Math.random(); } etc.. x= 16; x.sqrt() --> 4 x="256"; (+x).pow(2) //be sure to call the right .proto --> 65536 (1.234).sin().asin() --> 1.234 1..asin() * 2 -> 3.141592653589793 (2).pow(10) --> 1024 2..pow(10).sqrt() --> 32 (100).rnd() -> 0 <= n < 100 -- Jorge.
From: Cody Haines on 16 Feb 2010 20:29 Jorge <jorge(a)jorgechamorro.com> wrote: > Hi, > > Do you think -as I do- that the Math object is an ugly artifact ? > Well, here's a nice way of getting rid of it : > > Number.prototype.sin= function () { return Math.sin(+this); }; > Number.prototype.asin= function () { return Math.asin(+this); }; > Number.prototype.pow= function (p) { return Math.pow(+this, p); }; > Number.prototype.sqrt= function () { return Math.sqrt(+this); }; > Number.prototype.rnd= function () { return this*Math.random(); } > > etc.. > > x= 16; > x.sqrt() > --> 4 > > x="256"; > (+x).pow(2) //be sure to call the right .proto > --> 65536 > > (1.234).sin().asin() > --> 1.234 > > 1..asin() * 2 > -> 3.141592653589793 > > (2).pow(10) > --> 1024 > > 2..pow(10).sqrt() > --> 32 > > (100).rnd() > -> 0 <= n < 100 > -- > Jorge. > Just out of curiosity, does IE support this? I don't see why it wouldn't, just making sure -- --Cody Haines
From: kangax on 16 Feb 2010 23:44 On 2/16/10 10:10 PM, RobG wrote: > On Feb 17, 9:23 am, Jorge<jo...(a)jorgechamorro.com> wrote: >> Hi, >> >> Do you think -as I do- that the Math object is an ugly artifact ? >> Well, here's a nice way of getting rid of it : >> >> Number.prototype.sin= function () { return Math.sin(+this); }; > > I'm curious about the use of unary +. Presumably the identifier is > resolved to a number primitive in the first place, otherwise x.sin > wouldn't resolve to Number.prototype.sin. I was curious about this too. I'm guessing ToNumber conversion is there to make method intentionally generic, similar to, say, `String.prototype.trim` from ES5, which passes its this value through ToString before trimming a value. [...] -- kangax
From: RobG on 16 Feb 2010 22:10 On Feb 17, 9:23 am, Jorge <jo...(a)jorgechamorro.com> wrote: > Hi, > > Do you think -as I do- that the Math object is an ugly artifact ? > Well, here's a nice way of getting rid of it : > > Number.prototype.sin= function () { return Math.sin(+this); }; I'm curious about the use of unary +. Presumably the identifier is resolved to a number primitive in the first place, otherwise x.sin wouldn't resolve to Number.prototype.sin. Or have I missed something? [...] > x="256"; > (+x).pow(2) //be sure to call the right .proto > --> 65536 So if x must be a number in order for the right property to be found, why must it also be converted inside the function? -- Rob
From: Thomas 'PointedEars' Lahn on 17 Feb 2010 00:14
Cody Haines wrote: > Jorge <jorge(a)jorgechamorro.com> wrote: >> Do you think -as I do- that the Math object is an ugly artifact ? >> Well, here's a nice way of getting rid of it : >> >> Number.prototype.sin= function () { return Math.sin(+this); }; >> Number.prototype.asin= function () { return Math.asin(+this); }; >> Number.prototype.pow= function (p) { return Math.pow(+this, p); }; >> Number.prototype.sqrt= function () { return Math.sqrt(+this); }; >> Number.prototype.rnd= function () { return this*Math.random(); } >> >> etc.. >> >> x= 16; >> x.sqrt() >> --> 4 >> >> x="256"; >> (+x).pow(2) //be sure to call the right .proto >> --> 65536 >> >> (1.234).sin().asin() >> --> 1.234 >> >> 1..asin() * 2 >> -> 3.141592653589793 >> >> (2).pow(10) >> --> 1024 >> >> 2..pow(10).sqrt() >> --> 32 >> >> (100).rnd() >> -> 0 <= n < 100 >> [...] > > Just out of curiosity, does IE support this? I don't see why it > wouldn't, just making sure JScript 5.6.6626 as of IE 6.0.2800.1106 supports this. It stands to reason that later versions of JScript and Internet Explorer, therefore other MSHTML-based browsers, would also support this (I cannot test them here yet). In fact, given that, according to Editions 3 and 5 of the ECMAScript Language Specification, when evaluating the CallExpression's /MemberExpression/ any primitive value would be converted into an appropriate value of type Object (ES3/5, 11.2.3, 11.2.1, and 9.9), this SHOULD work everywhere where `Number.prototype' is supported (which AFAIK excludes only JavaScript 1.0 as of Netscape 2.x, and JScript 1.0 as of IE 3.0 and IIS 3.0 ).¹ Tests with JavaScript, Apple JSC, Opera ECMAScript, and KJS confirmed this a while ago; I could also confirm it for Google V8 2.0 as of Chrome 5.0.307.7 by now. (In fact, this idea is anything but original.) However, the better question is: Does it make sense to do this? You could lose the explicit type conversion to begin with (as it is done implicitly by the algorithms of the built-in methods of `Math'; see ES3/5, 15.8.2). Still, with regard to memory efficiency your stack would be one level higher than without it, and with regard to runtime efficiency you would be paying for one call more than without it. Stack space being a scarce resource, and calls being rather expensive, this approach does not appear to make much sense. PointedEars ___________ ¹ To be sure of that, I have debugged the algorithms of ECMAScript Ed. 5, and compared with Ed. 3; I can post more detailed results of my research if anyone is interested. -- var bugRiddenCrashPronePieceOfJunk = ( navigator.userAgent.indexOf('MSIE 5') != -1 && navigator.userAgent.indexOf('Mac') != -1 ) // Plone, register_function.js:16 |