Simple mathematical concepts I: Induction.

After reading this and this I realized something is really, really wrong about mathematical concepts out there. Proof by induction is a really, really simple yet powerful proof method.  In this post, I will talk about induction for natural numbers. Induction is based on two steps, usually called basis and inductive step. I will proof …

Read moreSimple mathematical concepts I: Induction.

Writing your own JRuby extension. Part II: Creating your first class.

What’s the point of coding a JRuby extension if you don’t create classes? Well, I cannot think of any case, but if you find one, please, let me know. Do you remember Java’s classes hierarchy? If so, you’ll realize  that Java objects inherit from java.lang.Object by default but that is not actually what we need. …

Read moreWriting your own JRuby extension. Part II: Creating your first class.

Writing your own JRuby extension. First problem.

Maybe, when requiring your just created extension, you get a LoadError. If it is the first time you require it, it is quite likely that you have not followed JRuby requiring conventions. If you want to know how require works, you can find the best documentation ever about it in the comment before org.jruby.runtime.load.LoadService class. …

Read moreWriting your own JRuby extension. First problem.

Writing your own JRuby extension. Part I: BasicLibraryService.

Note: not code in this post, but you can see the code in Github. Follow the links! Writing a JRuby extension is very easy, but there are almost not post out there about it. As far as I know, there is only one, Ola’s. It is a really good tutorial indeed, but it lacks some …

Read moreWriting your own JRuby extension. Part I: BasicLibraryService.

Do you wanna help us with pure-Java Nokogiri?

First things first, if you wanna help, you’ll need to clone the git repo. Just: git clone git://github.com/tenderlove/nokogiri.git cd nokogiri git checkout –track -b java origin/java Install the dependencies. Just: rake install:deps Because it uses some native libraries, you’ll need to do that with MRI. Finally, you’ll need to generate some files, just run jruby …

Read moreDo you wanna help us with pure-Java Nokogiri?

Final Status Update (or How to get Nokogiri in JRuby without FFI)

Hi, all, sorry for the silence all these months, but I’ve been working hard on Nokogiri. First things first, it is not complete yet. Anyway, I’m gonna tell you how to build a gem and start working with it. photo credit: Matthew Byrne Clone the repo and checkout the java branch. git clone git://github.com/tenderlove/nokogiri.git git …

Read moreFinal Status Update (or How to get Nokogiri in JRuby without FFI)

Status Update: RMagick4J, Nokogiri, ruby2java and a possible MagickWand4J

It’s been long time since last status update, but there are some things to tell, so here I am. Thankfully, this year I’m a GSoC student again (and my mentor is Tom too). The main part of my project would be porting Nokogiri to JRuby, so I haven’t code for RMagick for a while now. …

Read moreStatus Update: RMagick4J, Nokogiri, ruby2java and a possible MagickWand4J