Here's a use case: I have objects that register themselves as listeners for system notifications. When an object registers, I want to make sure we don't add that object twice. If the listener list is an array, then I have to iterate through the array every time we add a listener, which is expensive with a lot of listeners. If I could instead store the listeners in a hash, the add operation would just have to check if the object exists in the hash instead of looping through the entire array of listeners to check equality. I found this group because I'm looking for such a solution without having to implement toHashKey().
On Sep 11, 9:05 am, Allen Madsen <bla...@gmail.com> wrote: > I'm with kangax on this one. I have never needed this functionality. > > Allen Madsenhttp://www.allenmadsen.com > > On Fri, Sep 11, 2009 at 11:59 AM, James Aimonetti > > <james.aimone...@gmail.com> wrote: > > > My interest was piqued when reading > >http://www.timdown.co.uk/jshashtable/index.htmlif that helps further > > discussion of including the feature. > > > kangax wrote: > > >> On Sep 11, 7:08 am, "T.J. Crowder" <t...@crowdersoftware.com> wrote: > >> [...] > > >>> @Jim: > > >>>> Yep, this is Java-esque but that doesn't *always* equal evil! > > >>> Hardly ever! I'd say hashCode has a place. > > >>> Let's step back and ask the question: What are the use cases for a > >>> hash keyed by non-string objects? Are they compelling? (I'm not > >>> saying they aren't, just saying that before running off on an idea, we > >>> need to ask the question.) > > >> I would actually like to hear about use cases too. Developing web apps > >> for 3 years now I haven't ever needed to use hash with arbitrary keys. > >> It doesn't mean such thing is not useful; I'm just failing to see how > >> (and where) it can be applied in practice (especially in a context of > >> web apps). > > >> [...] > > >> -- > >> kangax > > > -- > > James Aimonetti > > mobile: 314.809.6307 > > work: 540.459.2220 > > email: james.aimone...@gmail.com > > website:http://jamesaimonetti.com --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Prototype: Core" group. To post to this group, send email to prototype-core@googlegroups.com To unsubscribe from this group, send email to prototype-core-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/prototype-core?hl=en -~----------~----~----~----~------~----~------~--~---
