Re: Array property of custom object

On Monday, May 2, 2016 at 8:08:32 PM UTC+3, Boris Zbarsky wrote:
> On 5/2/16 8:07 AM, Mihai Dobrescu wrote:
> > So, to be clear, I would expect to have a callback with the index of the array as parameter too... I guess here starts my confusion?
> 
> OK.  Can you please back up and clearly describe what you're trying to do?
> 
> If your object is `o` and script does `o.arr`, what sort of thing should 
> it get?  Should it get an actual JS Array in the Array.isArray() sense? 
>   Should it get something that allows indexing into it (more details 
> below) but isn't actually an Array?  Something else?
> 
> When script does `var x = o.arr[5]`, what should happen? Should the 
> value just be read directly out of the storage of `o.arr` (whatever that 
> is)? Should some code you control run and allow you to provide the value 
> being returned? Something else?
> 
> When script does `o.arr[5] = 7`, what should happen?  Should the value 
> just be written into the storage of `o.arr` (whatever that is)?  Should 
> some code you control run and do something with the value being 
> provided?  Something else?
> 
> -Boris

OK, I use objects with private data. For instance a structure instance defined like (this is a simple example) :

typedef struct S {
	int id;	
	char info[100];
} Data;

In my case, I access "info" as char array (due to some API specs I wrap).

For "id" I use JS_PSGS macro to define it as a property for an object "jsData". It is used a wrapper of type jsInt with private data int.
The Set/Get methods will always work with the private data.

For "info", I need some Array wrapper for objects of type jsChar (it is not a string). jsChar will have some private data of type char.

So, I expect to access somehow a "jsData"'s property named "info", of type Array, in order to individually set or get each array's element.
I could write functions for that, but it is not natural. It is possible to need to loop through the array's elements too.