Design Pattern

In an older post, I described Execute Around Pattern. In this post, let's understand how this pattern simplifies the solution while reading from files and writing to files. Suppose we have a text file that contains a few names one name per line. We want our program to

In my previous post, we saw how languages with higher order functions make the implementation of Command Pattern very trivial. With a slight modification, we can achieve the Execute Around pattern. Suppose we have two types of transactions (atomic operations). Let's represent them using closures transactionOne and transactionTwo

Command Pattern is one of the design patterns published in the GoF book. Command pattern is essentially encapsulating various types of request under a unified interface. The goal here is to minimise the coupling between executor and the client, with the system retaining the ability to evolve with new commands.

Suppose we have a list of numbers. def numbers = [1, 2, 3, 4, 5, 6, -1] We are asked to do the following 1. Find out all the even numbers in the list 2. Find out all the numbers divisible by 3 3. Find out all the negative numbers in