Override list.Add()

ID:1468778
 
Jan 11 2014, 4:23 pm
(See the best response by Ter13.)
Is there a way to override list.Add() to add some custom behavior to it?

And as a side question, if I do list+=something, will that still call list.Add() like list.Add(something) would?
Jan 11 2014, 4:27 pm
No. You'll have to make your own global proc, or something.

What is the custom behavior you want?
Jan 11 2014, 4:27 pm
Best response
No.

You are probably going to want to wrap a list in a datum to handle this kind of behavior:

collection
    var/list/data = list()
    proc
        Add(item)
            data += item
        Remove(item)
            return data.Remove(item)
        Index(pos)
            return data[pos]


Unfortunately, this will not permit you to use operators with the collection anymore, so you should use collection.data directly if you have a lot of non-specialized transactions, otherwise you are going to see a speed hit compared to using a normal list.

This is good for things like keeping a list ordered.
Jan 11 2014, 4:30 pm
In response to Kaiochao
Kaiochao wrote:
No. You'll have to make your own global proc, or something.

What is the custom behavior you want?

To remove all null references in the list from atoms that have ceased to exist
Jan 11 2014, 4:35 pm
Someone in the other thread took the time to give you a link that shows you how to do this:

http://www.byond.com/forum/?post=1468645#comment8253922
Jan 11 2014, 6:36 pm
In response to Ter13
Ter13 wrote:
Someone in the other thread took the time to give you a link that shows you how to do this:

http://www.byond.com/forum/?post=1468645#comment8253922

Yes and I tried this:

datum/Del()
    for(var/list/L) L-=src
    return ..()


But it shoots world.cpu to like 200% so it is unusable.

Jan 11 2014, 6:38 pm
Not to talk badly about the dead, but if Falacy wrote it... Probably best to ignore it. Falacy is partially to blame for a large number of the bad habits floating about here.

Use Lummox's example from that thread, not Falacy's.
Jan 11 2014, 7:00 pm
I would but I don't understand where or in what context he is saying to use it.
Jan 11 2014, 7:12 pm
Well, it's not going to happen automatically. With any kind of ease. You are going to need to set up Lummox's approach in some type of a list cleaning function, and you are going to want to call that before you interact with the list after a specified delay.

The cleanest approach I can think of to automatically handle this behavior would involve circular references, which are probably a bad idea as they can cause the garbage collector to fail.