On Jul 18, 2011, at 5:31 PM, Bob Nystrom wrote:
> class Point {
> constructor(x, y) {
> this.x = x;
> this.y = y;
> }
>
> zero() {
> return new Point(0, 0);
> }
>
> unit() {
> return new Point(1, 1);
> }
>
> prototype {
> manhattanDistance() {
> return Math.abs(this.x) + Math.abs(this.y);
> }
> }
> }
>
> Pros:
> 1. Makes it abundantly clear that prototype members are just that.
But that's not a good in itself, and your argument about many other languages
putting "instance methods" at the level that this approach uses for class
methods goes against.
> 2. Makes it clearer (I think?) that members on the constructor ("class") are
> that. Basically, the name of the surrounding curly ("prototype" or "class")
> tells you where the member goes.
This is a fair point but I think it is outweighed by the Cons (mine plus yours).
> Cons:
> 1. Prototype members, the most common case, are the most verbose and suffer
> two levels of indentation.
That's a problem too (in addition to the strangeness compared to other
languages with 'class' syntax).
> 2. constructor() is in weird limbo. Should it be under prototype or class?
It binds a prototype property (MyDate.prototype.constructor), absent more magic
to make that alias. It does not bind a class property (e.g.,
MyDate.constructor).
> 3. Lots'o'curlies.
This is a pain, but so are lots o' statics -- but generally class methods are
few, so it could be a wash.
> There may be a good solution hiding in here somewhere, but I'm not sure.
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