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Get introduced to the concept of metaprogramming. Learn how to level up your programming skills by discovering the full potential of the macro system in Elixir. Understand the ins and outs of metaprogramming at a fundamental level and write incredible libraries by doing more with less code.

Metaprogramming in Elixir

```
<div class\"row\"><h1> DSL </h1><article>Welcome!</article>
</div>
```

```
<div class\"row\"><h1> DSL </h1><article><p>Welcome!</p></article>
</div>
```

```
<div><h1> DSL </h1><article><p>Welcome!</p></article>
</div>
```

What will be the output of the following Elixir DSL for HTML?
```
markup do
  tag :div, class: "row" do
    tag :h2 do 
      text "DSL"
    end
    tag :article do
      tag :p, do: text "Welcome!" 
    end
  end
end
```

<p>What will be the output of the following Elixir DSL for HTML?</p>
<pre><code>markup do
  tag :div, class: &quot;row&quot; do
    tag :h2 do 
      text &quot;DSL&quot;
    end
    tag :article do
      tag :p, do: text &quot;Welcome!&quot; 
    end
  end
end
</code></pre>


```
<h1 class\"first\"><p> DSL </p><span><p>Hello User!</p></span>
</h1>
```

```
<p class\"first\"><p> DSL </p><span>Hello User!</span>
<p>
```

```
<h1 class\"row\">DSL<span><p>Hello User!</p></span>
</h1>
```

What will be the output of the following Elixir DSL for HTML?
```
markup do
  tag :h1, class: "first" do
    tag :p do 
      text "DSL"
    end
    tag :span do
      tag :p, do: text "Hello User!" 
    end
  end
end
```

<p>What will be the output of the following Elixir DSL for HTML?</p>
<pre><code>markup do
  tag :h1, class: &quot;first&quot; do
    tag :p do 
      text &quot;DSL&quot;
    end
    tag :span do
      tag :p, do: text &quot;Hello User!&quot; 
    end
  end
end
</code></pre>


What would be the buffer state at line 6?

> __Note__: The buffer states at other lines are added as comments.
```
1. markup do           // buff = ""
2.   div do            // buff = buff <> "<div>"
3.     h1 do           // buff = buff <> "<h1>"
4.      text "hello"  // buff = buff <> "hello"
5.     end            // buff = buff <> "</h1>"
6.   end              /* Guess the buffer state here */
7. end             // buff
```

<p>What would be the buffer state at line 6?</p>
<blockquote>
<p><strong>Note</strong>: The buffer states at other lines are added as comments.</p>
</blockquote>
<pre><code>1. markup do           // buff = &quot;&quot;
2.   div do            // buff = buff &lt;&gt; &quot;&lt;div&gt;&quot;
3.     h1 do           // buff = buff &lt;&gt; &quot;&lt;h1&gt;&quot;
4.      text &quot;hello&quot;  // buff = buff &lt;&gt; &quot;hello&quot;
5.     end            // buff = buff &lt;&gt; &quot;&lt;/h1&gt;&quot;
6.   end              /* Guess the buffer state here */
7. end             // buff
</code></pre>


What would be the buffer state at line 4?

> __Note__: The buffer states at other lines are added as comments.
```
1. markup do           // buff = ""
2.   span do            // buff = buff <> "<span>"
3.     h1 do           // buff = buff <> "<h1>"
4.       text "DSL is fun"  /* Guess the buffer state here */
5.     end            // buff = buff <> "</h1>"
6.   end              // buff = buff <> "</span>" 
7. end             // buff
```

<p>What would be the buffer state at line 4?</p>
<blockquote>
<p><strong>Note</strong>: The buffer states at other lines are added as comments.</p>
</blockquote>
<pre><code>1. markup do           // buff = &quot;&quot;
2.   span do            // buff = buff &lt;&gt; &quot;&lt;span&gt;&quot;
3.     h1 do           // buff = buff &lt;&gt; &quot;&lt;h1&gt;&quot;
4.       text &quot;DSL is fun&quot;  /* Guess the buffer state here */
5.     end            // buff = buff &lt;&gt; &quot;&lt;/h1&gt;&quot;
6.   end              // buff = buff &lt;&gt; &quot;&lt;/span&gt;&quot; 
7. end             // buff
</code></pre>


Introduction

The Language of Macros

Extending Elixir with Metaprogramming

Advanced Compile-Time Code Generation

Code Generation from Git API

How to Test Macros

Create an HTML Domain-Specific Language

With Great Power Comes Great Responsibility (and Fun!)

Test Your Knowledge!