Comments on: Extend a Generic List to Provide Dictionary-Like Lookups http://www.alvinashcraft.com/2008/09/22/extend-a-generic-list-to-provide-dictionary-like-lookups/ .NET Development Resources from a Progressive.NET Perspective Thu, 11 Mar 2010 08:48:50 -0800 http://wordpress.org/?v=2.9.2 hourly 1 By: Weekly Link Post 61 « Rhonda Tipton’s WebLog http://www.alvinashcraft.com/2008/09/22/extend-a-generic-list-to-provide-dictionary-like-lookups/comment-page-1/#comment-594 Weekly Link Post 61 « Rhonda Tipton’s WebLog Sun, 28 Sep 2008 23:49:35 +0000 http://www.alvinashcraft.com/2008/09/22/extend-a-generic-list-to-provide-dictionary-like-lookups/#comment-594 [...] Ashcraft shows us how to Extend a Generic List to Provide Dictionary-Like Lookups. “This is an abstracted example of what I did to simplify and centralize that code in a [...] [...] Ashcraft shows us how to Extend a Generic List to Provide Dictionary-Like Lookups. “This is an abstracted example of what I did to simplify and centralize that code in a [...]

]]> By: Jean-Philippe Leconte http://www.alvinashcraft.com/2008/09/22/extend-a-generic-list-to-provide-dictionary-like-lookups/comment-page-1/#comment-591 Jean-Philippe Leconte Tue, 23 Sep 2008 20:10:35 +0000 http://www.alvinashcraft.com/2008/09/22/extend-a-generic-list-to-provide-dictionary-like-lookups/#comment-591 Linq has an extension method to do exactly this. From a List : list.ToLookup ( k => k.ID ); From a List : list.ToLookup ( k => ( (IHasIdentifier) k).ID ); Linq has an extension method to do exactly this.

From a List :
list.ToLookup ( k => k.ID );

From a List :
list.ToLookup ( k => ( (IHasIdentifier) k).ID );

]]> By: Alvin Ashcraft http://www.alvinashcraft.com/2008/09/22/extend-a-generic-list-to-provide-dictionary-like-lookups/comment-page-1/#comment-589 Alvin Ashcraft Tue, 23 Sep 2008 10:27:21 +0000 http://www.alvinashcraft.com/2008/09/22/extend-a-generic-list-to-provide-dictionary-like-lookups/#comment-589 Thanks for the feedback Jamie. I think you are correct about creating a FindByID delegate for use with the Find method. Thanks for the feedback Jamie. I think you are correct about creating a FindByID delegate for use with the Find method.

]]> By: Jamie Ide http://www.alvinashcraft.com/2008/09/22/extend-a-generic-list-to-provide-dictionary-like-lookups/comment-page-1/#comment-588 Jamie Ide Tue, 23 Sep 2008 01:59:09 +0000 http://www.alvinashcraft.com/2008/09/22/extend-a-generic-list-to-provide-dictionary-like-lookups/#comment-588 I'm sorry, but I think this is poor advice. You should be using the List.Find method to do this, which will give you O(n) lookup performance, the same as iterating. I don't recall trying this, but you may be able to create a generic FindById delegate to pass to the Find method. If you need faster lookup, you should copy the elements to a Dictionary which will give you 0(1) performance. I’m sorry, but I think this is poor advice. You should be using the List.Find method to do this, which will give you O(n) lookup performance, the same as iterating. I don’t recall trying this, but you may be able to create a generic FindById delegate to pass to the Find method. If you need faster lookup, you should copy the elements to a Dictionary which will give you 0(1) performance.

]]>