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

DevotionGeo
For me it’s the semicolon, because I stopped using a semicolon in JavaScript, two other of my favorite languages, Elixir and Go don’t hav...
New
bot
Announcing the Error Handling Project Group | Inside Rust Blog. Want to follow along with Rust development? Curious how you might get in...
New
AstonJ
If you are experiencing Rails console using 100% CPU on your dev machine, then updating your development and test gems might fix the issu...
New
Jsdr3398
I really need developers to help create my messaging platform but I’m not sure how much they want etc. I’ve never hired anyone before :s...
New
New
DevotionGeo
What do you people do for reading Erlang docs? Is there something like Ruby’s ri? I installed manual pages for Erlang under /usr/local/...
New
almokhtar
Howdy, folks i have this question about it is ok to learn two different programming languages same time, well my story is i joined a comp...
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
KnowledgeIsPower
Do you just use plain Terraform alone? Do you use CDK for Terraform or other supporting tools (e.g. Terraform Cloud ) for Terraform?
New
apoorv-2204
I’m experimenting with Hexagonal / Clean Architecture in Elixir. The classic Behaviour + Impl split works great for mocking and isolating...
New

Other popular topics Top

Devtalk
Reading something? Working on something? Planning something? Changing jobs even!? If you’re up for sharing, please let us know what you’...
1052 22171 400
New
PragmaticBookshelf
Learn from the award-winning programming series that inspired the Elixir language, and go on a step-by-step journey through the most impo...
New
DevotionGeo
I know that -t flag is used along with -i flag for getting an interactive shell. But I cannot digest what the man page for docker run com...
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
AstonJ
We’ve talked about his book briefly here but it is quickly becoming obsolete - so he’s decided to create a series of 7 podcasts, the firs...
New
AstonJ
Was just curious to see if any were around, found this one: I got 51/100: Not sure if it was meant to buy I am sure at times the b...
New
PragmaticBookshelf
Author Spotlight: Peter Ullrich @PJUllrich Data is at the core of every business, but it is useless if nobody can access and analyze ...
New
sir.laksmana_wenk
I’m able to do the “artistic” part of game-development; character designing/modeling, music, environment modeling, etc. However, I don’t...
New
NewsBot
Node.js v22.14.0 has been released. Link: Release 2025-02-11, Version 22.14.0 'Jod' (LTS), @aduh95 · nodejs/node · GitHub
New
Fl4m3Ph03n1x
Background Lately I am in a quest to find a good quality TTS ai generation tool to run locally in order to create audio for some videos I...
New