MeEd
Title: Effective Haskell (Page 31)
At the bottom of page 31 when let is added to the example greeting I cannot get the example to work. I’ve tried rechecking spacing inside the example, made sure I copied the example correctly and put in hours trying to get the example to work. I get different errors every time I try to run it in ghci.
First Post!
RebeccaSkinner
Author of Effective Haskell
Hey, sorry you’re having a problem! Here’s a working version of the example you can copy and paste:
module Main where
makeGreeting salutation person =
let messageWithTrailingSpace = salutation <> " "
in messageWithTrailingSpace <> person
extendedGreeting person =
let hello = makeGreeting "Hello" person
goodDay = makeGreeting "I hope you have a nice afternoon" person
goodBye = makeGreeting "see you later" person
in hello <> "\n" <> goodDay <> "\n" <> goodBye
main = print $ extendedGreeting "George"
If you can paste your code and the output of the errors I’d be happy to help you spot what’s going on!
Popular Pragmatic Bookshelf topics
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
Dear Sophie.
I tried to do the “Authorization” exercise and have two questions:
When trying to plug in an email-service, I found the ...
New
The book has the same “Problem space/Solution space” diagram on page 18 as is on page 17. The correct Problem/Solution space diagrams ar...
New
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, ...
New
Hi, I have just acquired Michael Fazio’s “Kotlin and Android Development” to learn about game programming for Android. I have a game in p...
New
I found an issue in Chapter 7 regarding android:backgroundTint vs app:backgroundTint.
How to replicate:
load chapter-7 from zipfile i...
New
When installing Cards as an editable package, I get the following error:
ERROR: File “setup.py” not found. Directory cannot be installe...
New
When trying to run tox in parallel as explained on page 151, I got the following error:
tox: error: argument -p/–parallel: expected one...
New
It seems the second code snippet is missing the code to set the current_user:
current_user: Accounts.get_user_by_session_token(session["...
New
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 ...
New
Other popular topics
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
Stop developing web apps with yesterday’s tools. Today, developers are increasingly adopting Clojure as a web-development platform. See f...
New
Learn from the award-winning programming series that inspired the Elixir language, and go on a step-by-step journey through the most impo...
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
I ended up cancelling my Moonlander order as I think it’s just going to be a bit too bulky for me.
I think the Planck and the Preonic (o...
New
Intensively researching Erlang books and additional resources on it, I have found that the topic of using Regular Expressions is either c...
New
Was just curious to see if any were around, found this one:
I got 51/100:
Not sure if it was meant to buy I am sure at times the b...
New
Author Spotlight
Mike Riley
@mriley
This month, we turn the spotlight on Mike Riley, author of Portable Python Projects. Mike’s book ...
New
Author Spotlight:
VM Brasseur
@vmbrasseur
We have a treat for you today! We turn the spotlight onto Open Source as we sit down with V...
New
Jan | Rethink the Computer.
Jan turns your computer into an AI machine by running LLMs locally on your computer. It’s a privacy-focus, l...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /wasm
- /ruby
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /java
- /emacs
- /haskell
- /svelte
- /typescript
- /onivim
- /kotlin
- /c-plus-plus
- /crystal
- /tailwind
- /react
- /gleam
- /ocaml
- /elm
- /flutter
- /vscode
- /ash
- /html
- /opensuse
- /zig
- /deepseek
- /centos
- /php
- /scala
- /react-native
- /lisp
- /textmate
- /sublime-text
- /nixos
- /debian
- /agda
- /django
- /deno
- /kubuntu
- /arch-linux
- /nodejs
- /spring
- /ubuntu
- /revery
- /manjaro
- /lua
- /diversity
- /julia
- /markdown
- /c









