Qqwy
I stumbled across the following curious tidbit of how Elixir’s parser/compiler works:
defmodule Example do
def {} do
"Yes, this is allowed!"
end
end
iex> Example.{}
"Yes, this is allowed!"
I cannot imagine any serious use-case for this, but it is curious.
I believe the cause is that :{} is a special atom that Elixir uses in its AST-definition to describe tuples with more than two elements.
Where Next?
Trending in Discussions
Other Trending Topics
Latest on Elixir Forum
Sponsor Spotlight
Supporting innovation across the BEAM ecosystem.
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #library
- #deployment
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #elixirconf
- #channels
- #exunit
- #discussion
- #code-sync
- #podcasts
- #javascript
- #onsite
- #dialyzer
- #docker
- #authentication
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ecto-query
- #elixirconf-us
- #ai
- #blog-post
- #elixir-ls
- #phoenix_html
- #iex
- #graphql
- #genstage
- #websockets
- #supervisor
- #advent-of-code
- #distillery
- #processes
- #api
- #forms
- #hex
- #security
- #metaprogramming
Our Sponsors
Build Elixir applications with speed and confidence.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Error tracking, logs, uptime, and Just Enough APM. Built for developers.
Elixir, Erlang & BEAM conferences from Code Sync - join us in 2026!
Master modern tools, write cleaner code, and tackle real-world challenges.
Bringing learning, work and compliance together since 1987.
**Building the future of software with AI, trust, and human connection.**
The team behind Membrane, Popcorn, LiveDebugger. Available for hire.
Courses that'll move you from confusion to "Aha, now I get it!"
Showing Posts 1 to 3- Show Best Posts
- Show All (oldest first)
- Show All (newest first)
ityonemo
henrik
Not the same, but here’s another fun one: How to "expect(…).to" in Elixir – The Pug Automatic
Qqwy
It is impossible to import the
Examplemodule in this case, however, because that will make Elixir complain that you are attempting to override one of its special forms.That said, it is possible to wrap any piece of Elixir AST in a macro that alters how the code that is passed to it is expanded. In this way you are able to alter even the behaviour of Elixir’s special forms.
One place where I’ve used this in the past is the Solution library, where the clauses of
withandcase-statements are overridden to have slightly extended support for tuples.Another is e.g. the experiment I wrote late yesterday evening which allows bare captures to exist in pipes.
@henrik Thanks for sharing that piece of code! Tuple calls are indeed a strange historic artifact.