Some questions about Private Name Objects

[Rick Waldron]

On Thu, Sep 13, 2012 at 1:46 PM, Dean Landolt <dean at deanlandolt.com> wrote:

>
>
> On Thu, Sep 13, 2012 at 12:09 PM, Erik Arvidsson <erik.arvidsson at gmail.com
> > wrote:
>
>> On Thu, Sep 13, 2012 at 8:37 AM, Kevin Smith <khs4473 at gmail.com> wrote:
>> > 1) Is method name-collision a practical problem, or just a theoretical
>> > problem?  If it's just a theoretical problem, then we don't need unique
>> > names, and in teaching the language we can simply guide users away from
>> > trying to create "private methods".  In fact, without supporting syntax
>> it's
>> > unlikely that users would even bother trying to create them in the first
>> > place.
>>
>> Yes. This is a real problem.
>>
>> It is a common problem that we see a lot with "private" members using
>> naming conventions.
>>
>> class Base {
>>   constructor() {
>>     this._element = ...;
>>   }
>> }
>>
>> class Derived extends Base {
>>   constructor() {
>>     this._element = ...;  // OOPS!
>>   }
>> }
>>
>
>
> Another good example where this is a problem is on prototype chains, a
> good example of which you parenthetically noted (iterators). With unique
> names it becomes feasible to hang any properties and methods you want off
> of prototypes without worrying about collision. For instance, imagine an
> persistance lib with a Record.prototype.save method:
>
>     var rec = new Record({ save: 'whoops' });
>     rec.save() // TypeError: Property 'save' is not a function
>
> And thus we all fall back to the lovely Record.prototype.save.call(rec)
> pattern. Unique names neatly sidestep this, giving us back our prototype
> chains.
>

This could also be designed to use a WeakMap as the "store" for the data :)

https://gist.github.com/3716743


Rick


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