Macros Inject Code
Explore how Elixir macros enable code injection and manipulation through defmacro, quote, and unquote. Understand the compile-time behavior, code representation, and module loading needed to effectively use macros in functional programming.
We'll cover the following...
Introduction
Let’s pretend we’re the Elixir compiler. We read a module’s source top to bottom and generate a representation of the code we find. That representation is a nested Elixir tuple.
If we want to support macros, we need a way to tell the compiler that we’d like to manipulate a part of that tuple. We do that using defmacro, quote, and unquote.
In the same way that def defines a function, defmacro defines a macro. We’ll see what it looks like shortly. However, the interesting part starts not when we define a macro but when we use one.
When we pass parameters to a macro, Elixir ...