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
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
The following is cross-posted from the original Ray Tracer Challenge forum, from a post by garfieldnate. I’m cross-posting it so that the...
New
When I try the command to create a pair of migration files I get an error.
user=> (create-migration "guestbook")
Execution error (Ill...
New
Hi! I know not the intentions behind this narrative when called, on page XI:
mount() |> handle_event() |> render()
but the correc...
New
A Common-Sense Guide to Data Structures and Algorithms, Second Edition by Jay Wengrow @jaywengrow
Hi,
I have the paperback version of t...
New
Hello! Thanks for the great book.
I was attempting the Trie (chap 17) exercises and for number 4 the solution provided for the autocorre...
New
Running mix deps.get in the sensor_hub directory fails with the following error:
** (Mix) No SSH public keys found in ~/.ssh. An ssh aut...
New
I found an issue in Chapter 7 regarding android:backgroundTint vs app:backgroundTint.
How to replicate:
load chapter-7 from zipfile i...
New
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...
New
On page 78 the following code appears:
<%= link_to ‘Destroy’, product,
class: ‘hover:underline’,
method: :delete,
data: { confirm...
New
Other popular topics
A thread that every forum needs!
Simply post a link to a track on YouTube (or SoundCloud or Vimeo amongst others!) on a separate line an...
New
New
I’m thinking of buying a monitor that I can rotate to use as a vertical monitor?
Also, I want to know if someone is using it for program...
New
SpaceVim seems to be gaining in features and popularity and I just wondered how it compares with SpaceMacs in 2020 - anyone have any thou...
New
Rust is an exciting new programming language combining the power of C with memory safety, fearless concurrency, and productivity boosters...
New
New
This looks like a stunning keycap set :orange_heart:
A LEGENDARY KEYBOARD LIVES ON
When you bought an Apple Macintosh computer in the e...
New
Author Spotlight
Dmitry Zinoviev
@aqsaqal
Today we’re putting our spotlight on Dmitry Zinoviev, author of Data Science Essentials in ...
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
Develop, deploy, and debug BEAM applications using BEAMOps: a new paradigm that focuses on scalability, fault tolerance, and owning each ...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /ruby
- /wasm
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /emacs
- /java
- /haskell
- /svelte
- /onivim
- /typescript
- /kotlin
- /crystal
- /c-plus-plus
- /tailwind
- /react
- /gleam
- /ocaml
- /elm
- /flutter
- /vscode
- /ash
- /html
- /opensuse
- /zig
- /centos
- /deepseek
- /php
- /scala
- /react-native
- /sublime-text
- /textmate
- /lisp
- /nixos
- /debian
- /agda
- /django
- /kubuntu
- /deno
- /arch-linux
- /nodejs
- /revery
- /ubuntu
- /manjaro
- /spring
- /lua
- /diversity
- /markdown
- /julia
- /c








