Groovy Cookbook

Groovy Regular Expressions - The Definitive Guide

I’ve never enjoyed working with regular expressions in Java. It was always very error-prone. You had to remember to escape backslashes, and a very simple match elements check required writing at least 5 lines of code. Booooring. However, Groovy solved most of these issues, and today we are going to take a closer look at features like pattern operator, find operator or exact match operator. We will focus on learning the new syntax, as well as measuring and comparing its performance. Let’s begin!

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Groovy Cookbook

Tail-recursive methods in Groovy

Most of the object-oriented programmers prefer constructing algorithms using imperative style over using recursion. This is pretty obvious in the JVM ecosystem, where imperative iteration is much more efficient than recursive function call chain. However, what if I tell you that in Groovy you can take advantage of clean tail-recursive functions without sacrificing performance? Interested? Let’s deep dive into it.

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Programming tips

What is the most efficient way to iterate collection in Groovy? Let's play with JMH!

I guess you may heard about Groovy’s Collection.each(Closure cl) method - it was introduced 15 years ago [1] and it was a great alternative for a good old for-loop, for-each or even using an iterator approach. You may also heard, that you should not overuse it, because creating a closure to do such simple operation like collection iteration is an overhead. But what if I tell you that nothing could be further from the truth - Groovy’s each method may be faster than iterator or Java’s for-each. Sounds interesting? Enjoy the reading!

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How to

Divide a list to lists of n size in Java 8

Every Java developer works with lists daily. There are many popular list (or collection) operations implemented in the standard Java 8 library, but there is one that is useful and commonly used, yet missing - partitioning. In this blog post, I would like to show you how you can split any list into chunks of fixed size without using any 3rd party library. Let’s start!

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