AstonJ

AstonJ

Do you say 'unpack' or 'destructure'?

Consider this Erlang code:

Rectangle = {rectangle, 20, 10}.
{rectangle, Width, Height} = Rectangle.
> Width.
20
> Height.
10

When I was watching an Elixir video the person kept calling this ‘destructuring’ (which I think is what they say in the JS world?) but Joe Armstrong, in his book Programming Erlang, calls this ‘unpacking’ - so I am curious, how do you refer to it when using a BEAM language?

  • Unpack
  • Destructure
  • Use the terms interchangeably depending on the language
  • Something else - please say in thread!

0 voters

Most Liked

chriseyre2000

chriseyre2000

Technically it’s pattern matching since we can be more specific by repeating a variable to ensure that it is used in multiple places.

Eiji

Eiji

Object : typeof instance === "object". Special non-data but Structural type for any constructed object instance also used as data structures: new Object, new Array, new Map, new Set, new WeakMap, new WeakSet, new Date and almost everything made with new keyword;

Source: JavaScript data types and data structures - JavaScript | MDN

This quote shows us that equivalent/similar data types across languages are implemented and therefore grouped differently which means that we can’t use exactly same naming. Different naming forces new developer to think: Why it's named like that? and that ends up with looking for it’s definition.

The destructuring assignment syntax is a JavaScript expression that makes it possible to unpack values from arrays, or properties from objects, into distinct variables.

Source: Destructuring assignment - JavaScript | MDN

Having in mind that both destructure and unpack are used only for arrays and objects it’s confusing to use them in Elixir for other data types like for example string. Destructure naming could also be confusing for newbies as we have structs.

Destructure and unpack antonyms suggest that we have something structured or packed which is not always true. While it’s common to say that we are unpacking bits from string still we can’t say that we are unpacking something from literal like for example: 5 = variable.

Generally i.e. for all data types I prefer to think about some connection of assignment, fetch, pattern and take words (which are most common) like taking by pattern or something like that.

@AstonJ Considering your Erlang code we can say that we are taking items: rectangle, Width and Height by 3-element tuple pattern of Rectangle variable. What do you think about it?

Where Next?

Popular Backend topics Top

New
New
First poster: bot
The Complete AWS Lambda Handbook for Beginners (Part 1). In the first part of our Complete AWS Lambda Handbook for Beginners, we explain...
New
First poster: bot
proposal: Go 2: permit types to say they may only be created by containing package · Issue #43123 · golang/go. It would be useful to per...
New
mafinar
I did not add this to a “this weekend I’ll learn” like my few other journals as I am decided on using this in the long term. Last I work...
New
AstonJ
And the blog: Rails has been unapologetically full stack since the beginning. We’ve continuously sought to include ever-more default an...
New
Cellane
Phoenix 1.6.0 got released last week, with built-in authentication and mailer generators, a whole new HEEx (HTML-aware Embedded Elixir) e...
New
jaeyson
Hi all!, anybody tried this Elixir quiz from @Tetiana? She’s the one who made Elixircards.
New
Reinis
I’ve been diving into Bridgetown (a Jekyll successor) and learning about writing a more maintainable CSS.
New
pillaiindu
Cross posting from Elixir Forum. Build it with Phoenix is a nice course by Geoffrey Lessel @geo. But if you start with Phoenix 1.7.2 or ...
New

Other popular topics Top

New
PragmaticBookshelf
Design and develop sophisticated 2D games that are as much fun to make as they are to play. From particle effects and pathfinding to soci...
New
AstonJ
We have a thread about the keyboards we have, but what about nice keyboards we come across that we want? If you have seen any that look n...
New
dimitarvp
Small essay with thoughts on macOS vs. Linux: I know @Exadra37 is just waiting around the corner to scream at me “I TOLD YOU SO!!!” but I...
New
Exadra37
Oh just spent so much time on this to discover now that RancherOS is in end of life but Rancher is refusing to mark the Github repo as su...
New
PragmaticBookshelf
Build highly interactive applications without ever leaving Elixir, the way the experts do. Let LiveView take care of performance, scalabi...
New
hilfordjames
There appears to have been an update that has changed the terminology for what has previously been known as the Taskbar Overflow - this h...
New
PragmaticBookshelf
Develop, deploy, and debug BEAM applications using BEAMOps: a new paradigm that focuses on scalability, fault tolerance, and owning each ...
New
AstonJ
This is a very quick guide, you just need to: Download LM Studio: https://lmstudio.ai/ Click on search Type DeepSeek, then select the o...
New
PragmaticBookshelf
Use advanced functional programming principles, practical Domain-Driven Design techniques, and production-ready Elixir code to build scal...
New