Ruby Metaprogramming Examples

Self quote from programming ruby 1 9.

Ruby metaprogramming examples.

Ruby is an interpreted high level general purpose programming language it was designed and developed in the mid 1990s by yukihiro matz matsumoto in japan. It is because of this very feature that many gems such as rspec and activerecord can work the way they do. I m going to start with an example from the ruby on rails framework. In ruby the term metaprogramming refers to the dynamic nature of the language which allows you to define and redefine methods and classes at runtime.

Please refer our accompanying study notes and examples. This involves inspecting and modifying a program as it runs using constructs exposed by the language. Imagine that you have a database table for users that have columns such as name and email. In ruby the term metaprogramming refers to the dynamic nature of the language which allows you to define and redefine methods and classes at runtime.

Metaprogramming is often presented as a very nebulous and dangerous concept one that is difficult to explain and hard. For example when a user model is defined in rails with email as an attribute a method called find by email will be generated. Obviously the ruby on rails framework doesn t know what columns that you re going to have for the. 2nd review singleton.

Ruby is dynamically typed and uses garbage collection it supports multiple programming paradigms including procedural object oriented and functional programming according to the creator ruby was influenced by perl smalltalk eiffel. Nov 20 th 2015 10 34 am. Quote from the ruby object model. But it can be a bit confusing if you don t have a few specific examples.

Metaprogramming is the act of writing code that operates on code rather than on data. Metaprogramming is often presented as a very nebulous and dangerous concept one that is difficult to explain and hard to wrap your head around and thus should be avoided. Let s begin with a basic example. 1st review the built in read only variable self.

Let s start learning ruby metaprogramming. Self the current default object. You may have read about ruby metaprogramming before. Ruby metaprogramming one of the most interesting aspects of ruby enables the programming language to achieve an extreme level of expressiveness.

Metaprogramming is writing programs that write programs. Ruby metaprogramming by example. That s why in this article. We re going to look at some popular open source projects using ruby metaprogramming.

When does self change. All of them use some form of metaprogramming. Read the following articles. Add a method named foldl to ruby s native array class.