Ruby blocks, Procs and methods
Ruby provides the programmer with a set of very powerful features borrowed from the domain of functional programming, namely closures, high–order functions and first–class functions [1]. These features are implemented in Ruby by means of code blocks, Proc objects and methods (that are also objects) – concepts that are closely related and yet differ in subtle ways. In fact I found myself quite confused about this topic, having a difficulty to understand the difference between blocks, procs and methods and unsure about the best practices of using them. Additionally, having some background in Lisp and years of Perl experience, I was unsure of how the Ruby concepts map to similar idioms from other programming languages, like Lisp’s functions and Perl’s subroutines. Sifting through hundreds of newsgroup posts, I saw that I’m not the only one with this problem, and in fact quite a lot of ”Ruby Nubies” struggle with the same ideas.
In this article I lay out my understanding of this facet of Ruby, which comes as a result of extensive research of Ruby books, documentation and comp.lang.ruby, in sincere hope that other people will find it useful as well.
Posted by Administrator on Wednesday, November 01, 2006
