prototype shorthand (A::) sticks to 'then' and 'when'

[dbrans]

for k of A:: when k isnt constructor then 

compiles to

var k;
for (k in A.prototype.when(k !== constructor)) {}

and

if A:: then 2

produces a parse error

[satyr]

Usability aside, this is because you can access a property using any identifier, including reserved ones.

$ coffee -bpe 'A :: when'
A.prototype.when;

$ coffee -bpe 'A . prototype . when'
A.prototype.when;

[ghost]

for k of (A::) when k isnt constructor then 

[michaelficarra]

We could require the :: operator to be pushed up against its operands. It's not like anyone intentionally puts whitespace there anyway, do they?

[jashkenas]

For the record, the :: was never intended to be used without a right-hand connection. It's like writing object. standalone. Hence the syntax error.

[ghost]

@jaskenas

What about doing things like
Object.defineProperty A:: ...stuff...

[jashkenas]

Object.defineProperty A.prototype

... honestly, it might be worth getting rid of standalone @ while we're at it.

[TrevorBurnham]

I think people have grown attached to standalone @. The style I use in the book is to use standalone this instead (and @x), but I wonder if that may have been the wrong decision. After all, it makes perfect sense to highlight the specialness of this, that oh-so-common source of bugs. @ really pops out. In fact, I think I'd rather get rid of standalone this than standalone @. (Not a serious suggestion; obviously the same reasoning applies to this as to && and ||).

I'm indifferent to A::.

[GeoffreyBooth]

Not sure what the issue is here. if A:: then 2 should produce a parse error.