On Wed, Jun 17, 2015 at 10:35 PM, Andrea Giammarchi < [email protected]> wrote:
> OK **that one** I've no idea what supposes to improve exactly ... I should > have tried to realize your proposal better, apologies. > > After seeing that, I probably agree with Allen at this point we don't > really need that kind of syntax around JS (still IMHO, of course) > To each their own. :) I personally really like the bind syntax and have received a tremendously positive feedback on it - the Trine project alone has received over 1000 stars on GitHub, in under a week since release (last Thursday), and it's just showcasing a part of the power of the proposed syntax. > > Best Regards > > On Wed, Jun 17, 2015 at 6:01 PM, Jussi Kalliokoski < > [email protected]> wrote: > >> >> >> On Wed, Jun 17, 2015 at 7:13 PM, Allen Wirfs-Brock <[email protected] >> > wrote: >> >>> >>> On Jun 17, 2015, at 8:09 AM, Andrea Giammarchi wrote: >>> >>> Mostly every Array extra in ES5 would work with those functions, e.g. >>> >>> ```js >>> function multiplyPoints (_p2) { >>> var { x1: x, y1: y } = this; >>> var { x2: x, y2: y } = _p2; >>> return { x: x1 * x2, y: y1 * y2 }; >>> } >>> >>> var multiplied = manyPoints.map(multiplyPoints, centralPoint); >>> ``` >>> >>> It's not that common pattern but it gives you the ability to recycle >>> functions as both methods or filters or mappers or forEachers and >>> vice-versa. >>> >>> I personally use those kind of functions quite a lot to be honest, most >>> developers keep ignoring Array extra second parameter as context though, >>> they probably use a wrapped fat arrow within an IFI with call(context) :D >>> >>> >>> It seems to me that we already can quite nicely express in ES6 the use >>> of a function as a method: >>> >>> ```js >>> function multiplyPoints({x1, y1}, {x2,y2}) { >>> return { x: x1 * x2, y: y1 * y2 } >>> } >>> >>> class Point { >>> multiply(p2) {return multiplyPoints(this, p2)} >>> } >>> ``` >>> >>> or, perhaps a bit more OO >>> >>> ```js >>> class Point { >>> static multiply({x1, y1}, {x2,y2}) { >>> return new Point(x1 * x2, y1 * y2 ) //or new this(...) if you >>> care about subclassing Point >>> } >>> >>> multiply(p2) {return Point.multiply(this, p2)} >>> >>> constructor(x,y) { >>> this.x = x; >>> this.x = y; >>> } >>> } >>> ``` >>> >>> Regardless of how you express it, if you want the same function to be >>> used both as a standalone function and as an method, you are going to have >>> to have a line or two of code to install the function as a method. To me, >>> the one-line method definitions used above are about as concise and much >>> clearer in intent than `Point.prototype.multiply=multiplyPoints;` or >>> whatever other expression you would use to install such a function as a >>> method. And I would expect any high perf JIT to use inlining to completely >>> eliminate the indirection so, where it matters, there probably wound't be >>> any performance difference. >>> >>> Many JS programmers have historically been confused about the JS >>> semantics of `this` because it is over-exposed in non-method functions. >>> Things like the current proposal increases rather than mitigates the >>> potential for such confusion. if you are programming in a functional style, >>> don't write functions that use `this`. If you need to transition from >>> to/from OO and functional styles, be explicit as shown above. >>> >>> `this` is an OO concept. FP people, `this` is not for you; don't use >>> it, don't try to "fix it". >>> >> >> But I already am [1][1], and it allows for a much nicer syntax than >> functions that don't use `this`, and also composes well with built-ins >> (other than Object.*) This proposal is building on the proposed function >> bind syntax [2][2]. >> >> More examples of the power of the bind syntax can be found in the links, >> but the bind syntax combined with my proposal would for example allow this: >> >> ```JS >> function add (&a, b) { return a + b; } >> >> 2::add(3) // 5 >> ``` >> >> [1]: https://github.com/jussi-kalliokoski/trine >> [2]: https://github.com/zenparsing/es-function-bind >> >>> >>> Allen >>> >>> >>> >>> _______________________________________________ >>> es-discuss mailing list >>> [email protected] >>> https://mail.mozilla.org/listinfo/es-discuss >>> >>> >> >
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