Ruby Metaprogramming Examples

You may have read about ruby metaprogramming before.

Ruby metaprogramming examples.

1st review the built in read only variable self. Metaprogramming is writing programs that write programs. In this article toptal engineer nikola todorovic demystifies. Let s begin with a basic example.

All of them use some form of metaprogramming. This involves inspecting and modifying a program as it runs using constructs exposed by the language. It is because of this very feature that many gems such as rspec and activerecord can work the way they do. In the example below here are some of the meta changes we re making to the program.

I m going to start with an example from the ruby on rails framework. Nov 20 th 2015 10 34 am. Quote from the ruby object model. Add a method named foldl to ruby s native array class.

Self quote from programming ruby 1 9. That s why in this article. 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.

Let s start learning ruby metaprogramming. Metaprogramming is the act of writing code that operates on code rather than on data. Obviously the ruby on rails framework doesn t know what columns that you re going to have for the. We re going to look at some popular open source projects using ruby metaprogramming.

Please refer our accompanying study notes and examples. Examples of metaprogramming a basic example. But it can be a bit confusing if you don t have a few specific examples. 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.

Imagine that you have a database table for users that have columns such as name and email. Read the following articles. 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. 2nd review singleton.

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. For example when a user model is defined in rails with email as an attribute a method called find by email will be generated. Ruby metaprogramming one of the most interesting aspects of ruby enables the programming language to achieve an extreme level of expressiveness. Self the current default object.