Elixir Eval AST

When working with Elixir, there may be times when you need to programmatically access the Abstract Syntax Tree (AST) of some code. This is where the Elixir eval ast function comes in.

What is the AST?

In Elixir, the AST is a tree-like data structure that represents the syntactic structure of a piece of Elixir code. It is used internally by the Elixir compiler to generate bytecode, and can also be useful for metaprogramming and other advanced use-cases.

How to use the Elixir eval ast function

The Elixir eval ast function takes a string containing some Elixir code, and returns the AST of that code as a data structure. Here's an example:

iex> ast = Code.string_to_quoted("defmodule MyModule do\n  def my_function(a, b) do\n    a + b\n  end\nend\n")
iex> IO.inspect(ast, pretty: true)
{:__block__, [],
 [
   {defmodule, [context: Elixir, line: 1],
    [{:MyModule, [line: 1], Elixir}], nil},
   {def, [context: Elixir, line: 2],
    [{:my_function, [line: 2], [{:a, [], Elixir}, {:b, [], Elixir}]}],
    [
      do: {:+, [context: Elixir, line: 3], [{:a, [], Elixir}, {:b, [], Elixir}]}
    ]}
 ]}

As you can see, the ast variable contains the AST of the code we passed in. We can now manipulate this data structure programmatically to achieve various tasks.

Why use the Elixir eval ast function?

The Elixir eval ast function can be useful for a variety of tasks, such as:

• Building macros that generate Elixir code based on some input
• Analyzing code to look for bugs or optimization opportunities
• Building tools that automatically generate documentation or other artifacts based on Elixir code

Overall, the Elixir eval ast function provides a powerful tool for working with Elixir code at a low-level, and can be incredibly useful for advanced Elixir programmers.