Comments on: ActionScript 3 MultiMap Class

By: sascha

sascha — Sun, 21 Sep 2008 04:52:39 +0000

Sev, yes thanks for the tip. I might be rewriting the class anyway soon so I will try using tables.

By: Sev

Sev — Sun, 21 Sep 2008 01:51:17 +0000

Hmm.. looking through your code makes me wonder why you don’t use hash tables to store the array hash/map? I usually do sth like that (shortened, simplified):

_map : Object;

function setValue( key : String , value : * ) : void {
if ( _map[key] == undefined ) _map[key] = [];
_map[key].push(value);
}

That way you don’t have to iterate through all lists which is MUCH faster. All methods in your class would be feasible with that data structure (I think). Or is there sth I’m not getting?

By: Randall Salas

Randall Salas — Fri, 13 Jun 2008 19:31:41 +0000

Hi All:
I wonder if next thing if possible:
If more than one key is accepted, it will return values based on:
Key1, key2, key3, etc.

And if just one key is entered, it should return all values that match that key.

Thx.

Randall

By: Sascha

Sascha — Fri, 28 Sep 2007 02:25:36 +0000

Gaston, there’s an example of how to use it in the class comment. Or did you mean something else?

By: Gaston

Gaston — Thu, 27 Sep 2007 16:07:21 +0000

how do i implement it? can i see an example? tk.

By: Eduardo

Eduardo — Sat, 25 Aug 2007 17:29:34 +0000

Hey! Thxs for the reply!

I think I gave the wrong mail now it’s the correct! thanxS!!!

By: AS3 Datenstrukturen at flash und so…

AS3 Datenstrukturen at flash und so… — Wed, 22 Aug 2007 19:42:41 +0000

[...] MultiMap ist eine Erweiterung der Hash-Tabelle von polygonal. [...]

By: Actionscript Classes » MultiMap

Actionscript Classes » MultiMap — Wed, 22 Aug 2007 16:53:58 +0000

[...] http://blog.hexagonstar.com/as3_multimap_class/ [...]

By: sascha

sascha — Mon, 11 Jun 2007 03:53:37 +0000

Hi Michael, adding a getValues method that always returns an array is a good idea. But it makes me thinking about if in that case changing the getValue method to always return an array makes sense. If the user doesn’t provide a valueIndex an Array should always be expected so how about this …
Adding the getValues method and in the getValue method at the beginning use this:

if (valueIndex < 0) return getValues(key);

That way always an Array is returned if valueIndex was omitted. But then again it is questionable if valueIndex should be an optional or obligatory parameter.
Interesting to mention that your find method is still faster than the getValues method even though they are virtually the same. In fact typing the entry variable inside the for loop provides a small performance boost for my method.

By: Michael

Michael — Mon, 11 Jun 2007 00:26:03 +0000

ah I forgot to mention, when you omit the valueIndex parameter in the getValue() function and the entry has multiple items you don’t know if the function returns an array or an object/primitive. Maybe it would be better to always return an array (even if it contains only one item) or feed it with an empty array and the function fills out the array elements and instead returns the number of items:
var data:Array = []; var numItems:int = getValues(myKey, []);

By: Michael

Michael — Sun, 10 Jun 2007 23:38:19 +0000

Nice work Perhaps I would add a function that just retrieves all stored values at a given key perhaps like so:

public function getValues(key:*):Array { ... for (...) { if (entry.key === key) { return entry.data; } } return null; }

This would be a a little bit faster when often processing a bunch of values at a key.