How to get the struct type in Elixir

Article autor
August 12, 2021
How to get the struct type in Elixir
Elixir Newsletter
Join Elixir newsletter

Subscribe to receive Elixir news to your inbox every two weeks.

Oops! Something went wrong while submitting the form.
Elixir Newsletter
Expand your skills

Download free e-books, watch expert tech talks, and explore open-source projects. Everything you need to grow as a developer - completely free.

Table of contents

So you don’t know what’s the type of struct you’re passing somewhere? Maybe it can be one of few types and you have to distinguish them? Or any other reason… But it’s about checking the struct type. Just use one of the coolest Elixir features - pattern matching!

Check this out:

iex(1)> some_struct = %MyApp.User{}
iex(2)> %type{} = some_struct
iex(3)> type
MyApp.User

That’s just a hook point for a bunch of cool facilities, like function call by module type:

defmodule Chess.Bishop do
  def move(piece), do: move_diagonally(piece)
end

defmodule Chess.Rook do
  def move(piece), do: move_straight(piece)
end

defmodule Chess.Pawn do
  def move(piece), do: move_forward(piece)
end

And then in console:

iex(1)> piece = get_chess_piece()
iex(2)> %module{} = piece
iex(3)> module.move(piece)

Have fun! If you'd like to learn more about structs in Elixir, check this blog post: Elixir Trickery: Cheating on Structs, And Why It Pays Off.

Work with a team that keeps learning and building better software every day.

Related posts

Dive deeper into this topic with these related posts

No items found.

You might also like

Discover more content from this category

Skip file changes tracking in git

So, you’re changing this one file for local development purposes only. Maybe it’s config, maybe some source file, but one thing is certain - you don’t want those changes to be committed. And what’s worse, .gitignore doesn’t work.

How to check if an Elixir map has a given key in a guard?

Today's Advent of Code puzzle inspired me to create this TIL. It may sound trivial, but in fact, it's tricky if you are unfamiliar with the nuances of guards' functioning.

How to copy and paste within a terminal in macOS or Linux?

Sometimes we want to store some piece of information while using a terminal, for example, a result of an executed command. We usually save it into some temporary file which is going to be deleted after all. There’s a better way.