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

AstonJ
Currently a hot topic in the BEAM world, let’s start a thread for it (as suggested by @crowdhailer here) :smiley: What are your current...
New
DevotionGeo
Some time ago I read somewhere that Rocket will work with stable versions of Rust. The previous version’s changelog says, “Core: Removed...
New
New
First poster: bot
This Python script mimics Babbage’s Difference Engine. In Use this Python script to simulate Babbage’s Difference Engine, Python offered...
New
First poster: bot
What's so exciting about Postgres? with Craig Kerstiens (The Changelog #417). PostgreSQL aficionado Craig Kerstiens joins Jerod to talk ...
New
AstonJ
Just discovered Fika - looks pretty neat! fn sum(a: Int, b: Int) : Float do a + b end I quite like the syntax, though would probably ...
New
Exadra37
Finishing my app to take notes on Videos: I am aiming to put it online on my playground by this weekend. Edit: It’s up https://video...
New
lucasvegi
Hello guys! Perhaps some of you have already seen this invitation on other channels in the Elixir community or even responded to our surv...
New
geo
I found a collection of code snippets for getting visitor ip address from api.geoipapi.com/json for blocking malicious ip addresses or ha...
New
NKTgLaw
Hi everyone :waving_hand:, I’ve been experimenting with a physics-inspired principle called the NKTg Law of Variable Inertia. It connec...
New

Other popular topics Top

AstonJ
If it’s a mechanical keyboard, which switches do you have? Would you recommend it? Why? What will your next keyboard be? Pics always w...
New
PragmaticBookshelf
Machine learning can be intimidating, with its reliance on math and algorithms that most programmers don't encounter in their regular wor...
New
PragmaticBookshelf
Free and open source software is the default choice for the technologies that run our world, and it’s built and maintained by people like...
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
Rainer
My first contact with Erlang was about 2 years ago when I used RabbitMQ, which is written in Erlang, for my job. This made me curious and...
New
PragmaticBookshelf
Rails 7 completely redefines what it means to produce fantastic user experiences and provides a way to achieve all the benefits of single...
New
PragmaticBookshelf
Build efficient applications that exploit the unique benefits of a pure functional language, learning from an engineer who uses Haskell t...
New
AstonJ
If you want a quick and easy way to block any website on your Mac using Little Snitch simply… File > New Rule: And select Deny, O...
New
New
pragdave
Build robust LLM-powered apps, chatbots, and agents while mastering AI engineering principles that will help you outlast the tools and th...
New