molleweide

molleweide

Effective Haskell: Left and Right on page 321

Hi Rebecca,

On page 321 you use Left and Right in the function showLeftRight and I think that you should explain explicitly what Left and Right does because it is not obvious to me how they are used to select the type application.

0 384 2

First Post!

molleweide

molleweide

I mean, I can see in your example that Left is used to select the first type application, and Right the second one, (I THINK), but I am still unsure.

Where Next?

Popular Pragmatic Bookshelf topics Top

johnp
Running the examples in chapter 5 c under pytest 5.4.1 causes an AttributeError: ‘module’ object has no attribute ‘config’. In particula...
5 3547 1
New
GilWright
Working through the steps (checking that the Info,plist matches exactly), run the demo game and what appears is grey but does not fill th...
11 1077 5
New
ianwillie
Hello Brian, I have some problems with running the code in your book. I like the style of the book very much and I have learnt a lot as...
0 1500 3
New
Alexandr
Hi everyone! There is an error on the page 71 in the book “Programming machine learning from coding to depp learning” P. Perrotta. You c...
5 1334 4
New
mikecargal
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...
9 2012 5
New
mikecargal
Title: Hands-on Rust: question about get_component (page 295) (feel free to respond. “You dug you’re own hole… good luck”) I have somet...
1 1160 5
New
leonW
I ran this command after installing the sample application: $ cards add do something --owner Brian And got a file not found error: Fil...
5 4369 7
New
curtosis
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...
2 1442 3
New
mert
AWDWR 7, page 152, page 153: Hello everyone, I’m a little bit lost on the hotwire part. I didn’t fully understand it. On page 152 @rub...
0 1225 4
New
mcpierce
@mfazio23 I’ve applied the changes from Chapter 5 of the book and everything builds correctly and runs. But, when I try to start a game,...
0 1160 10
New

Other popular topics Top

wolf4earth
@AstonJ prompted me to open this topic after I mentioned in the lockdown thread how I started to do a lot more for my fitness. https://f...
193 4510 82
New
axelson
I’ve been really enjoying obsidian.md: It is very snappy (even though it is based on Electron). I love that it is all local by defaul...
38 4062 19
New
Rainer
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...
195 6396 95
New
AstonJ
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...
11 5382 4
New
AstonJ
Seems like a lot of people caught it - just wondered whether any of you did? As far as I know I didn’t, but it wouldn’t surprise me if I...
190 3839 79
New
New
foxtrottwist
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...
52 4894 22
New
AstonJ
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...
4 3745 1
New
PragmaticBookshelf
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...
16 4113 11
New
PragmaticBookshelf
Author Spotlight: Karl Stolley @karlstolley Logic! Rhetoric! Prag! Wow, what a combination. In this spotlight, we sit down with Karl ...
31 3800 16
New

Sub Categories: