Programming

The series ‘(def random)’ assembles video episodes dedicated to computer programming. Here, you’ll find explanations and examples of using the Clojure language, and over time, other programming languages as well.

Last night I received an e-mail in which one of my visitors asked me a few questions after reading the post about parsing phone numbers in Clojure. The question was seemingly simple and concerned a technical detail of software construction, but in reality the reader touched on a very important subject that I had been pondering years ago, and I decided to summarise it here.

Bindings let source-level names denote values and reference objects, while namespaces organize top-level Vars, Java classes, and aliases. In this installment, we will learn how these mechanisms shape resolution, scope, and visibility in Clojure.

Data types allow us to classify values according to various characteristics and to establish relations between the resulting classes. This helps the programmer define operations performed on data of different kinds, and it helps language mechanisms manage memory and detect certain kinds of errors. In Clojure, we deal with several interrelated type systems that we can extend, and by leveraging their polymorphic mechanisms, we are able to abstract data management and build unified information exchange interfaces.

Data structures, alongside algorithms expressed as operations, are a fundamental component of every computer program. When building applications, we choose structures that will be best suited for processing data within our adopted model.

The specific syntax of Lisp dialects allows one to precisely define and distinguish basic constructs, add new syntactic elements, and transform program forms as data during macro expansion. This stems from the use of simple yet well-thought-out ways of organizing and representing source code.