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
Which server-side languages are you most interested in right now? Anything new or relatively new that’s caught your eye? Maybe an older l...
New
New
First poster: bot
The Emerging Architectures for Modern Data Infrastructure. Five years ago, if you were building a system, it was a result of the code yo...
New
DevotionGeo
How Dgraph was running out of memory for some users, and how Go’s Garbage collector wasn’t enough, and Dgraph team used jemalloc to manag...
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
AstonJ
In case anyone else is wondering why Ruby 3 doesn’t show when you do asdf list-all ruby :man_facepalming: do this first: asdf plugin-upd...
New
jaeyson
Hi all!, anybody tried this Elixir quiz from @Tetiana? She’s the one who made Elixircards.
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
Hi everyone, Does anyone know when will “Agile Web Development in Rails 8” by Pragmatic Bookshelf release. I’m eager to dive into the la...
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

Other popular topics Top

dasdom
No chair. I have a standing desk. This post was split into a dedicated thread from our thread about chairs :slight_smile:
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
PragmaticBookshelf
Learn different ways of writing concurrent code in Elixir and increase your application's performance, without sacrificing scalability or...
New
Margaret
Hello everyone! This thread is to tell you about what authors from The Pragmatic Bookshelf are writing on Medium.
1147 29994 760
New
New
PragmaticBookshelf
Build modern server-driven web applications using htmx. Whatever programming language you use, you’ll write less (and cleaner) code. ...
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
PragmaticBookshelf
Leverage your existing Rails codebase to build iOS and Android apps with Hotwire Native – no Swift or Kotlin experience necessary. J...
New
AstonJ
Curious what kind of results others are getting, I think actually prefer the 7B model to the 32B model, not only is it faster but the qua...
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