Fl4m3Ph03n1x
Background
I few days ago I was checking some code from a co-worker and I was drawn to his usage of spec:
@spec hello(String.t(), String.t(), integer(), map()) :: any()
#function code here ....
We came together and he asked me why my usage of specs was different (I don’t use parenthesis):
# No parenthesis
@spec hello(String.t, String.t, integer, map) :: any
To which I responded:
"Well, the compiler will realize this is a function and will expand it automatically. So in reality, adding the extra parenthesis everywhere just adds more noise to your code without any real value and for functions with many arguments it makes the code harder to read. Also, since I am using the 80 characters per column limit, I find it that doing it this way is more compact while still delivering me the same amount of information. "
To which he replied:
Yeah but … in the official docs they use parenthesis everywhere. Why do they do it then?
Weerrmmmm… I have no idea.
Questions
- Do you use parenthesis in your
speccalls? - If so, why? (or why not?)
- Why does the documentation uses parenthesis every where?
- Are there any tangible benefits to using the parenthesis?
- What is the community standard on this matter ?
Where Next?
Trending in Questions
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
- #ai
- #full-time-contract
- #podcasts-by-brainlid
- #ecto-query
- #blog-post
- #elixirconf-us
- #elixir-ls
- #phoenix_html
- #iex
- #graphql
- #genstage
- #websockets
- #supervisor
- #advent-of-code
- #distillery
- #processes
- #elixirconf-eu
- #api
- #forms
- #security
- #metaprogramming
Our Sponsors
Supporting innovation across the BEAM ecosystem.
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!
Practical resources that improve the lives of professional developers.
Master modern tools, write cleaner code, and tackle real-world challenges.
Producing high quality Elixir screencasts since 2017.
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 2- Show Best Posts
- Show All (oldest first)
- Show All (newest first)
NobbZ
I use them in my
@specs for the very same reason I use them for zero-arity functions in my code. It removes ambiguity.If the parens are missing, I’ve always to check whether or not there is a
whenthat describes the item.lucaong
I noticed that the
mix formattask will add parentheses for all theModule.type()types likeString.t()orGenServer.server(), but does not for basic types likemaporinteger. So I tent to use the same convention in my code, but I don’t really know the reason. Possibly just consistency with the format of function calls, where the formatter also preferselems |> Enum.join()toelems |> Enum.jointo disambiguate between functions and special forms?Functionally they should be the same.