Thursday, January 8, 2004

Why Groovy and not JRuby? There's some discussion on why Groovy exists and why we didn't just use JRuby. Its a good question. Here's my attempt at an answer... FWIW I really like Ruby. Before I started working on Groovy I was leaning a bit more towards Python, as the Perliness of Ruby put me off a little bit. Though the more I worked on Groovy the more I liked the Ruby way of doing things and the less I liked Python (I think its something so trivial as all those underscores & self parameters, it just doesn't really feel OO).  I also found you could kinda pretend the Perliness wasn't there in Ruby :) So apart from a few fairly minor syntax changes (to make Groovy easier to learn & more familiar for Java developers) Groovy syntax today is fairly similar to Ruby (though without the global variable perliness of Ruby :). So why did we do Groovy? I think the main reasons are I've been a Java developer for many years now and I didn't want to throw away all the code & tools & platform and use a completely new language & platform & tools. Java sits on a JVM so I wanted to bring the neat Ruby/Python stuff into the JVM. I didn't wanna move to a new API (Ruby and Python have their own equivalents of the JDK which Jython and JRuby have to implement, since they are a Java port of the original languages). I wanted to keep the JDK but just make it more groovy. I wanted to use a language which created normal Java classes that Java developers could use, but still gain from all the neat Ruby/Python goodness without requiring Java developers throw away the whole JDK and start to learn another one. i.e. code written in Groovy is immediately available to Java developers as normal Java classes and vice versa It seemed like a fun thing to do :) So the main difference between JRuby and Groovy is that Groovy is specificially designed to sit on the JVM, to work seamlessly with existing Java code and for all the JDK & J2EE APIs to 'poke through'. JRuby is a port of Ruby and so tries to be Ruby implemented in Java. i.e. Groovy is the smallest possible addition to make Java development Ruby-ish - while also still supporting working in a statically typed environment as well. Groovy supports both static and dynamic typing so Java objects are seamlessly available in Groovy and vice versa. I can derive/overload Java classes in Groovy that are available to Java developers. i.e. Groovy is Java really; just using a Ruby-ish syntax.  So we're using the JVM's method dispatching rules (overload methods based on the types of the parameters), support Java interfaces and if you want to restrict some public APIs (method signatures) to certain types to implement Java interfaces & work nicely with Java objects you can. To make Groovy more Ruby-ish, we've added some Ruby-esque APIs to the JDK / J2EE APIs themselves. So for any String, Collection, Map, Array, File, Regex Matcher you can use closures to iterate and so forth [1, 2, 3].each { println(it) } Some comments on the above article talked about things going belly-up - well I don't see Ruby, Python or Groovy going away any time soon. Its just a question of using the right tool for the job. If you're a Java developer or working on a Java / J2EE project and need a more concise, easier & fun language to get things done, try Groovy (or JRuby or Jython). Even if you just use it for writing JUnit test cases or glue code you might like it. The neat thing about Groovy is that everything your Java-developer colleagues do is available to you in Groovy and vice versa since both languages just create Java classes & bytecode. So there's no need to 'switch' platforms or wholesale convince everyone you work with to switch languages. If you're not working with Java and (say) just need some simple unix scripts to do neat things well you'll probably find Ruby/Python a good choice. Use whichever you prefer - its about choice. 9:28:24 AM    comment []

Groovy Logo Contest heating up - fancy having a go? The Groovy logo contest is hotting up. Are you a budding artist / graphic designer kinda person? Come on, have a go, you'll have fun :) 8:56:34 AM    comment []