From: mortee <mortee.lists@...>
Date: 2007-09-19T15:07:00+09:00
Subject: Re: capturing access to array elements

>> Unfortunately, there isn't a single method that accesses the value at
>> a particular index. For example, see the following code. Note that the
>> #[] method isn't called by the other methods, including each. (Note
>> also that the following is not an exhaustive list, but does give you a
>> starting point for experimentally determining which method might call
>> others.)
> 
> Having said that it's probably easier to use Delegator to intercept
> method calls.  Maybe there's also another approach to solving this.
> Mortee, what are you trying to achieve?

Actually it's indifferent if I use Delegator or not. In my scenario, I
get an array of record from a library function, and I want to have those
records automatically extended with a module's methods, without any
extra work on the array's user's part (aside from once handling the
array itself).

But I don't want to traverse the array right when I do this action in
question on the array: I'd like to leave it that to the time the
elements are actually accessed. This is because I want to have records
added to the array afterwards be extended also; and it may take
time-consuming actions for the "array" to fetch its elements, so I don't
want to access them if not necessary.

That's why I opted to override its element-accessor methods. I guess the
main principle would be the same whether I override the methods of the
array object in question itself, or I use a delegator object which wraps
the array's methods (currently I use the latter, but I'd prefer the
former anyway).

mortee