Ted

Ted

Getting Clojure: 'compute-area' does not compile (page 89)

The top of page 89 states:

and we also got the calculation wrong:

user=> (defn compute-area [diameter]
  #_=> (* PI radius (/ diameter 2.0)))
#'user/compute-area

The code above does not compile:

Unable to resolve symbol: radius in this context

The intended code is probably something like:

(defn compute-area [diameter]
  (let [radius (/ diameter 2.0)]
    (* PI radius radius)))

Where Next?

Popular Pragmatic Bookshelf topics Top

belgoros
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
brianokken
Many tasks_proj/tests directories exist in chapters 2, 3, 5 that have tests that use the custom markers smoke and get, which are not decl...
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...
New
mikecargal
Title: Hands-On Rust (Chapter 11: prefab) Just played a couple of amulet-less games. With a bit of debugging, I believe that your can_p...
New
JohnS
I can’t setup the Rails source code. This happens in a working directory containing multiple (postgres) Rails apps. With: ruby-3.0.0 s...
New
swlaschin
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
adamwoolhether
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
s2k
Hi all, currently I wonder how the Tailwind colours work (or don’t work). For example, in app/views/layouts/application.html.erb I have...
New
bjnord
Hello @herbert ! Trying to get the very first “Hello, Bracket Terminal!" example to run (p. 53). I develop on an Amazon EC2 instance runn...
New
dachristenson
@mfazio23 Android Studio will not accept anything I do when trying to use the Transformations class, as described on pp. 140-141. Googl...
New

Other popular topics Top

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...
New
DevotionGeo
The V Programming Language Simple language for building maintainable programs V is already mentioned couple of times in the forum, but I...
New
mafinar
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
gagan7995
API 4 Path: /user/following/ Method: GET Description: Returns the list of all names of people whom the user follows Response [ { ...
New
rustkas
Intensively researching Erlang books and additional resources on it, I have found that the topic of using Regular Expressions is either c...
New
Maartz
Hi folks, I don’t know if I saw this here but, here’s a new programming language, called Roc Reminds me a bit of Elm and thus Haskell. ...
New
PragmaticBookshelf
Author Spotlight Jamis Buck @jamis This month, we have the pleasure of spotlighting author Jamis Buck, who has written Mazes for Prog...
New
Help
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
AnfaengerAlex
Hello, I’m a beginner in Android development and I’m facing an issue with my project setup. In my build.gradle.kts file, I have the foll...
New
AstonJ
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

Sub Categories: