PragProg Customers

From Ruby to Elixir:

yba

yba

From Ruby to Elixir:

@sb8244

From Ruby to Elixir -
iex(1)> Enum.reduce([1, 2, 3], 0, fn num, ac → if num > max, do: num, else: ac end)
error: undefined variable “max”
└─ iex:6
** (CompileError) cannot compile code (errors have been logged)
command not working (page 42)

1 comment
#errata/book-from-ruby-to-elixir
1 234 1

First Post!

sb8244

sb8244

Author of From Ruby to Elixir and Real-Time Phoenix

Oof, thanks for this! I will make sure it’s fixed (and have an action item to go through every code entry in book to make sure it works properly.)

If it’s not clear, the ac variable should be called max here. I originally called it accumulator, but I find max easier to understand as that represents the purpose of the accumulation.

Post #2

Where Next?

View thread on forum
View From Ruby To Elixir's book portal
Post errata for this book
Post a suggestion for this book
Post a question about this book
Post a review about this book
Home PragProg Customers
#errata/book-from-ruby-to-elixir
1 234 1
Last post

Popular Pragmatic Bookshelf topics Top

mikecargal
PragProg Customers

Hands-On Rust: Wrong multiplier for 8x8 console in main.rs
Title: Hands-On Rust (Chap 8 (Adding a Heads Up Display) It looks like ​.with_simple_console_no_bg​(SCREEN_WIDTH*2, SCREEN_HEIGHT*2...
#errata/book-hands-on-rust
9 2026 5
New
lirux
PragProg Customers

The Ray Tracer Challenge: "Computing the normal on a transformed sphere" ebook test
Hi Jamis, I think there’s an issue with a test on chapter 6. I own the ebook, version P1.0 Feb. 2019. This test doesn’t pass for me: ...
#errata/book-the-ray-tracer-challenge
10 1461 5
New
frasette
PragProg Customers

A Common-Sense Guide to Data Structures and Algorithms, Second Edition: erroneous extra space complexity (page400)
A Common-Sense Guide to Data Structures and Algorithms, Second Edition by Jay Wengrow @jaywengrow Hi, I have the paperback version of t...
#errata/book-a-common-sense-guide-to-data-structures-and-algorithms-second-edition
4 1180 2
New
adamwoolhether
PragProg Customers

Distributed Services with Go: receiving Unknown flag: --go_opt when compiling protobuf (page 20)
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 ...
/book-distributed-services-with-go
0 4924 3
New
brian-m-ops
PragProg Customers

Python Testing with pytest, Second Edition: cards pip install error (page 12)
#book-python-testing-with-pytest-second-edition Hi. Thanks for writing the book. I am just learning so this might just of been an issue ...
#errata/book-python-testing-with-pytest-second-edition
4 1191 3
New
fynn
PragProg Customers

Build a Weather Station with Elixir and Nerves: SGP30 vs SGP40
This is as much a suggestion as a question, as a note for others. Locally the SGP30 wasn’t available, so I ordered a SGP40. On page 53, ...
#suggestion/book-build-a-weather-station-with-elixir-and-nerves
0 1292 2
New
adamwoolhether
PragProg Customers

Distributed Services With Go: Unable to pass readiness/liveness checks. (page 210, 215)
I’m not quite sure what’s going on here, but I’m unable to have to containers successfully complete the Readiness/Liveness checks. I’m im...
/book-distributed-services-with-go
5 1420 5
New
hgkjshegfskef
PragProg Customers

The Ray Tracer Challenge: cannot pass scaling test (page 69-70)
The test is as follows: Scenario: Intersecting a scaled sphere with a ray Given r ← ray(point(0, 0, -5), vector(0, 0, 1)) And s ← sphere...
#question/book-the-ray-tracer-challenge
1 1093 4
New
akraut
PragProg Customers

Programming Phoenix LiveView: Display Image Uploads (pdf p142)
The markup used to display the uploaded image results in a Phoenix.LiveView.HTMLTokenizer.ParseError error. lib/pento_web/live/product_l...
#errata/book-programming-phoenix-liveview
2 2102 9
New
creminology
PragProg Customers

Real Time Phoenix Errata P17: Getting first sample working with Phoenix 1.6.x
Skimming ahead, much of the following is explained in Chapter 3, but new readers (like me!) will hit a roadblock in Chapter 2 with their ...
#errata/book-real-time-phoenix
6 1116 5
New

Other popular topics Top

AstonJ
General Dev>Hardware

Which keyboard do you have?
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...
#hardware/keyboards#sticky#mechanical-keyboards
144 9115 50
New
AstonJ
General Dev>Code Editors

Poll: Which code editor do you use?
You might be thinking we should just ask who’s not using VSCode :joy: however there are some new additions in the space that might give V...
#community#polls/vim/emacs#code-editors/vscode#notepad/sublime-text#atom/textmate#codespaces#brackets/onivim#geany
121 5796 61
New
AstonJ
General Dev>Dev Chat

How fast do you type? Check your WPM here!
Do the test and post your score :nerd_face: :keyboard: If possible, please add info such as the keyboard you’re using, the layout (Qw...
typing-speed-test.aoeu.eu
/keyboards
82 7682 31
New
AstonJ
Backend>Chat

How to install Ruby 3 with ASDF
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...
/ruby#asdf
11 5961 4
New
PragmaticBookshelf
Backend>Learning Resources

Programming WebRTC
Use WebRTC to build web applications that stream media and data in real time directly from one user to another, all in the browser. ...
pragprog.com
#pragprog#published-book/js#webrtc/book-programming-webrtc
27 6969 6
New
PragmaticBookshelf
Community>In The Spotlight

Spotlight: Jamis Buck (Author) Interview and AMA!
Author Spotlight Jamis Buck @jamis This month, we have the pleasure of spotlighting author Jamis Buck, who has written Mazes for Prog...
#author-spotlight/ruby/book-the-ray-tracer-challenge/book-mazes-for-programmers
21 6352 9
New
PragmaticBookshelf
Backend>Learning Resources

Programming Ruby 3.2 (5th Edition)
Programming Ruby is the most complete book on Ruby, covering both the language itself and the standard library as well as commonly used t...
twitter.com
#pragprog/ruby/rails#published-book/book-programming-ruby-3-2-5th-edition
28 8550 13
New
DevotionGeo
General Dev>Questions

Do you prefer regular mechanical keyboards or low profile mechanical keyboards and why?
I have always used antique keyboards like Cherry MX 1800 or Cherry MX 8100 and almost always have modified the switches in some way, like...
/keyboards#mechanical-keyboards
27 3877 9
New
Fl4m3Ph03n1x
AI>Questions

What are the best text-to-speech ai generation tools that you can run locally?
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...
#ai#text-to-speech
6 8411 3
New
xiji2646-netizen
AI>Chat

Claude Code's entire source just leaked (512K lines) - anyone else digging through it?
Woke up to this today: Claude Code’s complete source code exposed via npm source map. Not a snippet. All 512,000 lines. 1,900 TypeScript ...
#claude
1 5903 4
New
Back to top

Latest in From Ruby to Elixir

From Ruby to Elixir Portal ❯

PragProg Customers

Pragmatic Bookshelf PragProg Customers ❯

Latest on Devtalk

Devtalk ❯

We ❤️ helpful members!

We reward our most helpful members via our MOTM scheme - by giving away a whopping 25 books per year!

Member of the Month

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

Categories:

Sub Categories:

Popular Portals

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

We're in Beta

About us Mission Statement See our Roadmap