Comments for dherman at mozilla

Comment on Now that’s a nice ‘stache by FremyCompany

FremyCompany — Sat, 03 Dec 2011 17:40:02 +0000

Another good solution would be to FIX the ASI to automatically insert a semicolon EXCEPT if the statement on current line doesn’t make sense (there’s a parenthesis open, it ends with an operator, …) OR if the next line starts with a binary operator OR a dot.

This is the way VB.NET does it, I really like it. I almost never have problems when using Autmatic Line Continuation (and, BTW, most statements are written in one single line).

var a = function() { // doesn't make sense, continue to next line // ... } // makes sense; the next line doesn't start by operator or dot -> stop parsing statement and create a new one (a || b) // make sense, but next line starts with a dot .doSomething() // make sense, but next line starts with a dot .doSomethingElse()

Current ASI behavior is broken. We seriously need to fix that a day or another.

Comment on Now that’s a nice ‘stache by dherman

dherman — Fri, 02 Dec 2011 23:20:08 +0000

@Neil:

Fair enough — good food for thought.

Comment on Now that’s a nice ‘stache by Neil Rashbrook

Neil Rashbrook — Fri, 02 Dec 2011 17:51:27 +0000

I did consider assignment syntax but I couldn’t see how that would extend to getters and setters.

Comment on Now that’s a nice ‘stache by dherman

dherman — Fri, 02 Dec 2011 17:25:14 +0000

@allesio:

I agree that it can be abused, but I feel the same way about excessive amounts of method chaining. IMO, this simply provides a clearer way of doing what people currently do, but distinguishing when you’re using method chaining for side effect (with a method that returns this), and when you’re using it to get a new value. But if you don’t like the style of lots of nested method chaining, you certainly don’t have to use it. Taste in programming style is always going to vary.

As for backwards compatibility, you bet — we are always vigilant about compatibility.

Comment on Now that’s a nice ‘stache by dherman

dherman — Fri, 02 Dec 2011 17:21:29 +0000

@Neil:

Definitely useful for prototypes. For regular methods, I would just use assignment instead of mixing it up with function declaration syntax:

foo.prototype.{
neg = function() { this._bar = -this._bar; }
};

I could see adding a get syntax. Interesting thoughts, definitely worth considering. Thanks!

Comment on Now that’s a nice ‘stache by alessioalex

alessioalex — Fri, 02 Dec 2011 15:02:27 +0000

In my opinion this code looks really ugly I hope at least that backwords compatibility is kept if this code is implemented.

Comment on Now that’s a nice ‘stache by Neil Rashbrook

Neil Rashbrook — Fri, 02 Dec 2011 11:10:39 +0000

This looks like it could be extended into a sane method for defining prototypes. Currently we can either do something like
function foo(bar) { this._bar = bar; } foo.prototype = { neg: function neg() { this._bar = -this._bar; }, get bar() { return this._bar; } };
but that destroys properties on the existing prototype, such as foo.prototype.constructor, which is bad for potential inheritance, or
function foo(bar) { this._bar = bar; } foo.prototype.neg = function neg() { this._bar = -this._bar; }; foo.prototype.__defineGetter__("bar", function() { return this._bar; });
which is longwinded despite using SpiderMonkey-specific syntax. Instead I would like to see this:
function foo(bar) { this._bar = bar; } foo.prototype.{ function neg() { this._bar = -this._bar; } get bar () { return this._bar; }; };

Comment on Now that’s a nice ‘stache by Justin Dolske

Justin Dolske — Fri, 02 Dec 2011 05:23:16 +0000

Just came here to say hooray for nattybo! \o/

Comment on Now that’s a nice ‘stache by dherman

dherman — Fri, 02 Dec 2011 05:18:35 +0000

@Mook:

I suggested a reformed with using the prefix dot-notation like your suggestion a long time ago, and it has a really bad interaction with semicolon insertion: notice how in the assignments in your example, they end with an expression, and the next line starts with a dot? That means that there’s no inserted semicolon! Semicolons are only inserted if it can’t parse, and 17.bar and “hello”.baz parse just fine.

Comment on Now that’s a nice ‘stache by Mook

Mook — Fri, 02 Dec 2011 05:03:10 +0000

Sounds like it actually really wants to be with(); if you merge the first example and your proposed syntax, you get something unambiguous (though a little wordy):
array.{ .pop() .pop() .pop() } path.{ .moveTo(10, 10) .stroke("red") .fill("blue") .ellipse(50, 50) } this.{ .foo = 17 .bar = "hello" .baz = true }

(I’m assuming automatic semicolon insertion here to match your examples; I’d personally prefer to be explicit, though.) Yes, that’s basically copying the VB with syntax – but hey, if it manged to do something right, why not learn from it? This way we can use other variables too:
this.{ alert("dimensions are " + .width + " x " + .height); }
(Let’s assume the deepest mono-stache wins when you nest them, or something…)