PragProg Customers

Effective Haskell: Chapter 1 “Creating New Variables”

pennychase

pennychase

Effective Haskell: Chapter 1 “Creating New Variables”

@RebeccaSkinner

In the “Creating New Variables” section of Chapter 1, it says that you can’t reassign variables once defined. But new Haskellers might try things out in ghci and discover they can redefine a variable. It probably makes sense to point out that there’s some magic in ghci without explaining monads and do notation :slight_smile:

1 comment
#suggestion/book-effective-haskell
1 468 1

First Post!

RebeccaSkinner

RebeccaSkinner

Author of Effective Haskell

Great callout. I updated it and called it “a concession to usability”

Post #2

Where Next?

View thread on forum
View Effective Haskell'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
#suggestion/book-effective-haskell
1 468 1
Last post

Popular Pragmatic Bookshelf topics Top

abtin
PragProg Customers

Distributed Services With Go - gogoproto on linux
page 20: … protoc command… I had to additionally run the following go get commands in order to be able to compile protobuf code using go...
#errata/book-distributed-services-with-go
14 2953 7
New
iPaul
PragProg Customers

The Definitive ANTLR 4 Reference: Program deprecation warning
page 37 ANTLRInputStream input = new ANTLRInputStream(is); as of ANTLR 4 .8 should be: CharStream stream = CharStreams.fromStream(i...
#errata/book-the-definitive-antlr-4-reference
4 987 0
New
telemachus
PragProg Customers

Warnings in Python Testing With Pytest Chapter 2
Python Testing With Pytest - Chapter 2, warnings for “unregistered custom marks” While running the smoke tests in Chapter 2, I get these...
#pragprog#errata/book-python-testing-with-pytest
5 2081 1
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
jdufour
PragProg Customers

The Cucumber for Java Book:
Hello! On page xix of the preface, it says there is a community forum "… for help if your’re stuck on one of the exercises in this book… ...
#question/book-the-cucumber-for-java-book
3 1143 1
New
herminiotorres
PragProg Customers

Programming Phoenix LiveView: Typo
Hi! I know not the intentions behind this narrative when called, on page XI: mount() |> handle_event() |> render() but the correc...
#errata/book-programming-phoenix-liveview
3 1307 17
New
Charles
PragProg Customers

Programming Phoenix LiveView: book not updated to version 1.6 (p. 18)
In general, the book isn’t yet updated for Phoenix version 1.6. On page 18 of the book, the authors indicate that an auto generated of ro...
#errata/book-programming-phoenix-liveview
9 2051 12
New
adamwoolhether
PragProg Customers

Powerful Command-Line Applications in Go: Exercise Solutions (many pages)
Is there any place where we can discuss the solutions to some of the exercises? I can figure most of them out, but am having trouble with...
#question/book-powerful-command-line-applications-in-go
17 1396 9
New
EdBorn
PragProg Customers

Agile Web Development with Rails 7: (page 70)
Title: Agile Web Development with Rails 7: (page 70) I am running windows 11 pro with rails 7.0.3 and ruby 3.1.2p20 (2022-04-12 revision...
#question/book-agile-web-development-with-rails-7
0 1129 1
New
NaplesDave
PragProg Customers

PragProg Customers Kotlin and Android Development: pg. 8 Build Gradle error: Could not get unknown property 'kotlin_version'
I am using Android Studio Chipmunk | 2021.2.1 Patch 2 Build #AI-212.5712.43.2112.8815526, built on July 10, 2022 Runtime version: 11.0....
#question/book-kotlin-and-android-development-featuring-jetpack
0 1456 2
New

Other popular topics Top

PragmaticBookshelf
Backend>Learning Resources

Web Development with Clojure, Third Edition
Stop developing web apps with yesterday’s tools. Today, developers are increasingly adopting Clojure as a web-development platform. See f...
pragprog.com
#pragprog#web-development/clojure#published-book/book-web-development-with-clojure-third-edition
5 4584 1
New
PragmaticBookshelf
General Dev>Learning Resources

The Pragmatic Programmer, 20th Anniversary Edition
Andy and Dave wrote this influential, classic book to help their clients create better software and rediscover the joy of coding. Almost ...
pragprog.com
#pragprog#published-book/book-the-pragmatic-programmer-20th-anniversary-edition
4 4782 0
New
dasdom
General Dev>Dev Chat

Standing Desks
No chair. I have a standing desk. This post was split into a dedicated thread from our thread about chairs :slight_smile:
#workspace#opinions
177 9886 77
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
Exadra37
Linux>Chat

RancherOS is in end of life
Oh just spent so much time on this to discover now that RancherOS is in end of life but Rancher is refusing to mark the Github repo as su...
#linux#rancheros
10 6358 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
AstonJ
AI>Chat

How to: Run DeepSeek on Mac, Windows, and Linux!
This is a very quick guide, you just need to: Download LM Studio: https://lmstudio.ai/ Click on search Type DeepSeek, then select the o...
#macs/deepseek#guides#lm-studio
14 9328 10
New
PragmaticBookshelf
Backend>Learning Resources

Elixir Patterns
This book forgoes the abstract and instead provides concrete examples to help you better leverage the unique properties of Elixir, Erlang...
pragprog.com
#pragprog/elixir/erlang#published-book#beam/book-elixir-patterns
2 3476 2
New
PragmaticBookshelf
General Dev>Learning Resources

Write Better with Vale
Lint your docs like code: turn any style guide into enforceable rules with Vale and publish clear, consistent content every time. ...
pragprog.com
#pragprog#published-book#vale/book-write-better-with-vale
8 9973 5
New
PragmaticBookshelf
Backend>Learning Resources

Programming Clojure, Fourth Edition
Quickly turn complex problems into simple, working solutions using functional programming, safe concurrency, and the expressive tools of ...
pragprog.com
#pragprog
4 1975 3
New
Back to top

Latest in Effective Haskell

Effective Haskell 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