Development on a Shoestring

Archive for the ‘General’ Category

image(via Simon Job) Google Maps now has maximum resolution images for Sydney.  Not just Sydney actually, here’s the Penrith Regatta Centre.  How about the Three Sisters at KatoombaNewcastle’s covered too, and it looks like everywhere in between is covered too!  This is a huge update.  Doesn’t goes so far south though, the high res layers seem to stop at Waterfall.

Cool things we can now see:

Oh and sorry, but Melbourne doesn’t have this yet.

Comparing two arrays (or IEnumerables) in C#

Much to my surprise I found that .NET 3.5 doesn’t seem to have a native method for comparing two arrays or collections of any type.  The LINQ extension methods offer a whole lot of added functionality for IEnumerable<T> collections, but not native comparison.  The Equals method is still the base object.Equals method that does a reference equality (i.e. Are these two the same object?) not a value equality (do they contain the same values?)

So, finding myself needing an equality comparison between two arrays, I’ve written the following extension method:

   1: /// <summary>
   2: /// Checks whether a collection is the same as another collection
   3: /// </summary>
   4: /// <param name="value">The current instance object</param>
   5: /// <param name="compareList">The collection to compare with</param>
   6: /// <param name="comparer">The comparer object to use to compare each item in the collection.  If null uses EqualityComparer(T).Default</param>
   7: /// <returns>True if the two collections contain all the same items in the same order</returns>
   8: public static bool IsEqualTo<TSource>(this IEnumerable<TSource> value, IEnumerable<TSource> compareList, IEqualityComparer<TSource> comparer)
   9: {
  10:     if (value == compareList)
  11:     {
  12:         return true;
  13:     }
  14:     else if (value == null || compareList == null)
  15:     {
  16:         return false;
  17:     }
  18:     else
  19:     {
  20:         if (comparer == null)
  21:         {
  22:             comparer = EqualityComparer<TSource>.Default;
  23:         }
  24:  
  25:         IEnumerator<TSource> enumerator1 = value.GetEnumerator();
  26:         IEnumerator<TSource> enumerator2 = compareList.GetEnumerator();
  27:  
  28:         bool enum1HasValue = enumerator1.MoveNext();
  29:         bool enum2HasValue = enumerator2.MoveNext();
  30:  
  31:         try
  32:         {
  33:             while (enum1HasValue && enum2HasValue)
  34:             {
  35:                 if (!comparer.Equals(enumerator1.Current, enumerator2.Current))
  36:                 {
  37:                     return false;
  38:                 }
  39:  
  40:                 enum1HasValue = enumerator1.MoveNext();
  41:                 enum2HasValue = enumerator2.MoveNext();
  42:             }
  43:  
  44:             return !(enum1HasValue || enum2HasValue);
  45:         }
  46:         finally
  47:         {
  48:             if (enumerator1 != null) enumerator1.Dispose();
  49:             if (enumerator2 != null) enumerator2.Dispose();
  50:         }
  51:     }
  52: }
  53:  
  54: public static bool IsEqualTo<TSource>(this IEnumerable<TSource> value, IEnumerable<TSource> compareList)
  55: {
  56:     return IsEqualTo(value, compareList, null);
  57: }
  58:  
  59: public static bool IsEqualTo(this IEnumerable value, IEnumerable compareList)
  60: {
  61:     return IsEqualTo<object>(value.OfType<object>(), compareList.OfType<object>());
  62: }

Updated: Jugen (see comment below) made some quality suggestions that I’ve used to improve the code here.  To see the state of the code when the comment was made, see here.

It gives you an extension methods on any collection that implements IEnumerable<T>.  There is an optional parameter of type IEqualityComparer<TSource> which if not null will be used to compare each item in the collections.  Otherwise it will use the default comparer for TSource. It will also work for untyped IEnumerable collections, the overloaded method passes the collections through to the IsEqualTo<TSource> method with object as the TSource.  This is really just there for backwards compatibility.

As far as speed goes, I ran a test with 2 collections of 10,000,000 (I stopped there because I started getting out of memory exceptions when I was populating the test collections after that!) items & it took 0.89 seconds, so I think that’d do for most scenarios.  If you want to use this code you can grab a copy of it here.

Sweet.  I didn’t see this before, but Firebug has a new beta version too, which means that it works in Firefox 3 beta 4.  Grab it from the releases page under the Firebug 1.1 Betas heading.  Possibly the single most useful Firefox plugin for me, the fact that it wasn’t working in the beta releases of FF3 was what was stopping me from switching to the beta. No more excuses now, the Adblock Plus plugin even works.

Mozilla Firefox 3 beta 4 available

Mozilla has released the 4th beta of the upcoming Firefox 3 browser.  Check out the review of the new beta by Mozilla Links.  Updates in this release:

  • Improvements to the user interface: better search support in the Download Manager, ability to zoom entire page or just the text, continuing look and feel improvements on Windows Vista, Windows XP, Mac OS X and Linux.
  • Richer personalization through: location bar that uses an algorithm based on site visit recency and frequency (called “frecency”) to provide better matches against your history and bookmarks for URLs and page titles, as well as an adaptive learning algorithm which tunes itself to your browsing habits.
  • Improved platform features such as: support for HTML5’s window.postMessage and window.messageEvent, JavaScript 1.8 improvements, and offline data storage for web applications.
  • Performance improvements: changes to our JavaScript engine as well as profile guided optimization resulted in significant gains over previous releases in the popular SunSpider test from Apple, web applications like Google Mail and Zoho Office run much faster, and continued improvements to memory usage drastically reduce the amount of memory consumed over long web browsing sessions.

There’s a link to the download site at the bottom of this page.

It has also been announced that there will be a 5th beta release, with the code freeze on the 18th of March, which means the beta should be available around March 31st. Or they may release it on 1st April just to screw with everyone :)

Google adds site search underneath site links

imageI hadn’t noticed this before, but Google has added a site search box underneath the site links in their results.  

Not sure what criteria they’re using to generate this, because it doesn’t work for every site.  The SMH gets it, but Drive doesn’t.  It seems to be based on sites that are listed on Google News and their size.  That’s a total guess just based on the couple of dozen of searches I’ve checked out.

Not sure how I missed this seeing as it was posted on the official blog site.  The official word on what sites it will show up for is:

This feature will now occur when we detect a high probability that a user wants more refined search results within a specific site. Like the rest of our snippets, the sites that display the site search box are chosen algorithmically based on metrics that measure how useful the search box is to users

Not sure what that means in real terms, but as I said, I’ve only seen it show up for sites that exist in Google News.  That may simply be coincidental though, as people are often searching those sites too.

Update: Strike my theory. The search box shows up for gimp.org & ubuntu.org & they’re not in Google News.  I guess it’s just down to the pigeons then.

Windows Update doesn’t work in IE8

So I installed IE8 and checked out a few sites.  Plenty of sites look a bit strange, but possibly most surprising is that the windows update site doesn’t work:

image

But but 8 is later than 5 isn’t it?????

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