Comments on: Variance Basics in Java and Scala http://oldfashionedsoftware.com/2008/08/26/variance-basics-in-java-and-scala/ Wed, 25 Jan 2012 15:21:25 +0000 hourly 1 http://wordpress.com/ By: Santiago Basulto http://oldfashionedsoftware.com/2008/08/26/variance-basics-in-java-and-scala/#comment-727 Mon, 09 Jan 2012 14:22:32 +0000 http://matthewmalone.wordpress.com/?p=118#comment-727 Great post brother. Thanks a lot!

]]> By: senthil http://oldfashionedsoftware.com/2008/08/26/variance-basics-in-java-and-scala/#comment-711 Sat, 20 Aug 2011 09:49:26 +0000 http://matthewmalone.wordpress.com/?p=118#comment-711 Very useful. Thanks

]]> By: Arun http://oldfashionedsoftware.com/2008/08/26/variance-basics-in-java-and-scala/#comment-652 Tue, 19 Oct 2010 19:18:00 +0000 http://matthewmalone.wordpress.com/?p=118#comment-652 nice intro .. thanks

]]> By: Ming http://oldfashionedsoftware.com/2008/08/26/variance-basics-in-java-and-scala/#comment-632 Sun, 21 Mar 2010 17:49:56 +0000 http://matthewmalone.wordpress.com/?p=118#comment-632 thanks for this blog. It really helps!

]]> By: Self Help « Matt Malone’s Old-Fashioned Software Development Blog http://oldfashionedsoftware.com/2008/08/26/variance-basics-in-java-and-scala/#comment-601 Thu, 10 Dec 2009 17:25:17 +0000 http://matthewmalone.wordpress.com/?p=118#comment-601 [...] The Time and Length classes extend Dimension and are concrete, so they must implement the addition operator. The operators have the same signature as the one from Dimension except for the return type. When creating a subtype, we are allowed to narrow the return types, so I made them more specific. Time.+ returns not merely a Dimension as in the supertype but a Time. Parameters, on the other hand, can only have their types widened in subtypes, so they remain Dimension. This is because the return type is a covariant position and the parameter type is a contravariant position. If you don’t know what variance is, I have an article on it. [...]

]]> By: startingscala http://oldfashionedsoftware.com/2008/08/26/variance-basics-in-java-and-scala/#comment-69 Tue, 30 Sep 2008 15:26:44 +0000 http://matthewmalone.wordpress.com/?p=118#comment-69 again i have to say: This was very usefull to me! :)

im very curious how good i can apply that in some more complex environment to solve problems efficiently.

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