
nappa85
Rust Brain Teasers - How long is a String? (page 22)
The phrase
Unicode string character by character can consume a lot more memory
than you expected. The string love: ❤ is 7 characters long, requires 12
bytes of storage in a String—and 32 bytes of memory when processed as
individual characters. This may seem like a small amount of memory,
but if your reader enters the entirety of War and Peace into your program’s
input box, per-character parsing may require more resources than you
expected
gives, in my humble opinion, the wrong idea that iterators allocate memory.
What’s written is true if I do my_string.chars().collect::<Vec<char>>()
, but only iterating overs chars won’t consume any memory, the single chars are transmuted from original string bytes.
I suggest to reformulate the example clarifing that iterators won’t allocate memory
First Post!

herbert
Author of Hands-on Rust
Thank you! I agree - the iterator text should be clarified. I’ve added this to the Beta-2 list.
Popular Pragmatic Bookshelf topics

Following the steps described in Chapter 6 of the book, I’m stuck with running the migration as described on page 84:
bundle exec sequel...
New

I thought that there might be interest in using the book with Rails 6.1 and Ruby 2.7.2. I’ll note what I needed to do differently here.
...
New

On the page xv there is an instruction to run bin/setup from the main folder. I downloaded the source code today (12/03/21) and can’t see...
New

The generated iex result below should list products instead of product for the metadata. (page 67)
iex> product = %Product{}
%Pento....
New

When trying to generate the protobuf .go file, I receive this error:
Unknown flag: --go_opt
libprotoc 3.12.3
MacOS 11.3.1
Googling ...
New

When I run the coverage example to report on missing lines, I get:
pytest --cov=cards --report=term-missing ch7
ERROR: usage: pytest [op...
New

When installing Cards as an editable package, I get the following error:
ERROR: File “setup.py” not found. Directory cannot be installe...
New

Hi,
I completed chapter 6 but am getting the following error when running:
thread 'main' panicked at 'Failed to load texture: IoError(O...
New

The markup used to display the uploaded image results in a Phoenix.LiveView.HTMLTokenizer.ParseError error.
lib/pento_web/live/product_l...
New

When running the program in chapter 8, “Implementing Combat”, the printout Health before attack was never printed so I assumed something ...
New
Other popular topics

Hello Devtalk World!
Please let us know a little about who you are and where you’re from :nerd_face:
New

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

Thanks to @foxtrottwist’s and @Tomas’s posts in this thread: Poll: Which code editor do you use? I bought Onivim! :nerd_face:
https://on...
New

“Finding the Boundaries” Hero’s Journey with Noel Rappin @noelrappin
Even when you’re ultimately right about what the future ho...
New

I am asking for any distro that only has the bare-bones to be able to get a shell in the server and then just install the packages as we ...
New

Here’s the story how one of the world’s first production deployments of LiveView came to be - and how trying to improve it almost caused ...
New

Biggest jackpot ever apparently! :upside_down_face:
I don’t (usually) gamble/play the lottery, but working on a program to predict the...
New

Author Spotlight
Jamis Buck
@jamis
This month, we have the pleasure of spotlighting author Jamis Buck, who has written Mazes for Prog...
New

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

This is cool!
DEEPSEEK-V3 ON M4 MAC: BLAZING FAST INFERENCE ON APPLE SILICON
We just witnessed something incredible: the largest open-s...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /wasm
- /ruby
- /erlang
- /phoenix
- /keyboards
- /rails
- /js
- /python
- /security
- /go
- /swift
- /vim
- /clojure
- /java
- /emacs
- /haskell
- /onivim
- /svelte
- /typescript
- /crystal
- /c-plus-plus
- /kotlin
- /tailwind
- /gleam
- /react
- /flutter
- /elm
- /ocaml
- /ash
- /vscode
- /opensuse
- /centos
- /php
- /deepseek
- /html
- /zig
- /scala
- /textmate
- /debian
- /sublime-text
- /nixos
- /lisp
- /agda
- /react-native
- /kubuntu
- /arch-linux
- /revery
- /ubuntu
- /django
- /manjaro
- /spring
- /diversity
- /nodejs
- /lua
- /slackware
- /c
- /julia
- /markdown