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
Python Testing With Pytest - Chapter 2, warnings for “unregistered custom marks”
While running the smoke tests in Chapter 2, I get these...
New
Title: Web Development with Clojure, Third Edition, pg 116
Hi - I just started chapter 5 and I am stuck on page 116 while trying to star...
New
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...
New
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:
...
New
Hi,
build fails on:
bracket-lib = “~0.8.1”
when running on Mac Mini M1 Rust version 1.5.0:
Compiling winit v0.22.2
error[E0308]: mi...
New
Hi! I know not the intentions behind this narrative when called, on page XI:
mount() |> handle_event() |> render()
but the correc...
New
I’m running Android Studio “Arctic Fox” 2020.3.1 Patch 2, and I’m embarrassed to admit that I only made it to page 8 before running into ...
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 am getting an error I cannot figure out on my test.
I have what I think is the exact code from the book, other than I changed “us...
New
Hello faithful readers! If you have tried to follow along in the book, you are asked to start up the dev environment via dx/build and ar...
New
Other popular topics
I know that these benchmarks might not be the exact picture of real-world scenario, but still I expect a Rust web framework performing a ...
New
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...
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
A few weeks ago I started using Warp a terminal written in rust. Though in it’s current state of development there are a few caveats (tab...
New
This is going to be a long an frequently posted thread.
While talking to a friend of mine who has taken data structure and algorithm cou...
New
Rails 7 completely redefines what it means to produce fantastic user experiences and provides a way to achieve all the benefits of single...
New
Build efficient applications that exploit the unique benefits of a pure functional language, learning from an engineer who uses Haskell t...
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
Get the comprehensive, insider information you need for Rails 8 with the new edition of this award-winning classic.
Sam Ruby @rubys
...
New
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...
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
- /flutter
- /elm
- /vscode
- /ash
- /html
- /opensuse
- /zig
- /centos
- /deepseek
- /php
- /scala
- /react-native
- /lisp
- /textmate
- /sublime-text
- /nixos
- /debian
- /agda
- /django
- /deno
- /kubuntu
- /arch-linux
- /nodejs
- /revery
- /ubuntu
- /manjaro
- /spring
- /julia
- /diversity
- /lua
- /markdown
- /c









