billboswell
Effective Haskell: Chapter 9 - Monad instance error (page 357)
Creating the instance of Monad Outlaw described in the text results in error:
• No instance for (Applicative Outlaw)
arising from the superclasses of an instance declaration
• In the instance declaration for ‘Monad Outlaw’
Resolved by adding Applicative instance:
Instance Applicative Outlaw where
pure = return
First Post!
RebeccaSkinner
Author of Effective Haskell
Good catch, thanks. I’ll add an errata item about this.
Popular Pragmatic Bookshelf topics
page 37
ANTLRInputStream input = new ANTLRInputStream(is);
as of ANTLR 4 .8 should be:
CharStream stream = CharStreams.fromStream(i...
New
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...
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
Hi Travis! Thank you for the cool book! :slight_smile:
I made a list of issues and thought I could post them chapter by chapter. I’m rev...
New
Title: Web Development with Clojure, Third Edition, vB17.0 (p9)
The create table guestbook syntax suggested doesn’t seem to be accepted ...
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
The allprojects block listed on page 245 produces the following error when syncing gradle:
“org.gradle.api.GradleScriptException: A prob...
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
Hi, I need some help, I’m new to rust and was learning through your book. but I got stuck at the last stage of distribution. Whenever I t...
New
Book: Programming Phoenix LiveView, page 142 (157/378), file lib/pento_web/live/product_live/form_component.ex, in the function below:
d...
New
Other popular topics
I am thinking in building or buy a desktop computer for programing, both professionally and on my free time, and my choice of OS is Linux...
New
I’ve been hearing quite a lot of comments relating to the sound of a keyboard, with one of the most desirable of these called ‘thock’, he...
New
Just done a fresh install of macOS Big Sur and on installing Erlang I am getting:
asdf install erlang 23.1.2
Configure failed.
checking ...
New
I am asking for any distro that only has the bare-bones to be able to get a shell in the server and then just install the packages as we ...
New
Crystal recently reached version 1. I had been following it for awhile but never got to really learn it. Most languages I picked up out o...
New
I am trying to crate a game for the Nintendo switch, I wanted to use Java as I am comfortable with that programming language. Can you use...
New
If you want a quick and easy way to block any website on your Mac using Little Snitch simply…
File > New Rule:
And select Deny, O...
New
Author Spotlight:
David Bryant Copeland
@davetron5000
We’re so happy to bring you another Author Spotlight, a series where we sit dow...
New
Author Spotlight:
Peter Ullrich
@PJUllrich
Data is at the core of every business, but it is useless if nobody can access and analyze ...
New
zig/http.zig at 7cf2cbb33ef34c1d211135f56d30fe23b6cacd42 · ziglang/zig.
General-purpose programming language and toolchain for maintaini...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /wasm
- /ruby
- /erlang
- /phoenix
- /keyboards
- /rails
- /js
- /python
- /security
- /go
- /swift
- /vim
- /clojure
- /emacs
- /haskell
- /java
- /onivim
- /svelte
- /typescript
- /crystal
- /kotlin
- /c-plus-plus
- /tailwind
- /gleam
- /ocaml
- /react
- /elm
- /flutter
- /vscode
- /ash
- /opensuse
- /centos
- /html
- /php
- /deepseek
- /zig
- /scala
- /textmate
- /lisp
- /sublime-text
- /nixos
- /debian
- /react-native
- /agda
- /kubuntu
- /arch-linux
- /revery
- /django
- /ubuntu
- /manjaro
- /spring
- /nodejs
- /diversity
- /lua
- /julia
- /slackware
- /c
- /markdown
Devtalk Sponsors
Practical resources that improve the lives of professional developers.
We build trusted fault-tolerant systems that scale to billions of users.
Real-time error tracking, performance insights, and observability for devs.
Develop your skills with books, videos, and courses.
Catch errors, track performance, monitor hosts and more.
Enabling companies to succeed by building software people love.
Courses that move you from confusion to "Aha, now I get it!"