#groovy 2.0

[gingeyorke]

[bloidonia]

Groovy Common Extensions on Maven

Last week I pushed my groovy-common-extensions project to maven via sonatype using the brilliant Gradle Nexus plugin by @bmuschko

More extensions are described on the project page, and thanks to André Steingress and Dan Woods for their contributions!

@tim_yates

[bloidonia]

What's new in Groovy 2.0: inject with default initialValue

Traditionally in Groovy, the inject method takes an initial value and a Closure to execute over all elements in the delegate.  For example to calculate the product of a series of Integers, you would need to set the initial value to 1 so that then multiplying this with each element in turn gets you the desired result, ie:

In Groovy 2.0 (and also 1.8.7) there is another form of inject which will take the first element in the collection as the initialValue, and then iterate over the rest of the collection.

This means that the above code can now be written as:

This becomes more useful and readable when you consider the example of trying to find the intersection for a list of lists.  With the old method, you'd need to do something like:

But this can now be written as:

Have fun!

@tim_yates

[bloidonia]

What's new in Groovy 2.0: takeWhile and dropWhile

There are loads of major changes in Groovy 2.0 such as Static type-checking, Static Compilation, Modularity and invokeDynamic.  For a run down on these and the other major changes and additions, you can read Guillaume Laforge's article on InfoQ here.

I'm going to briefly cover some of the smaller additions that might not get publicity elsewhere.

First up, we have the two new Collection methods from Andrew Taylor; takeWhile and dropWhile which have also been added to Groovy 1.8.7.

Both of these methods are available on the types List, Iterable, Map, ArrayList, Iterator and CharSequence (though the CharSequence method is not available in Groovy 1.8.7)

Here's an example of their usage:

And as you can see (for Groovy 2.0 at least) they also work on CharSequences

@tim_yates