MBrooks

MBrooks

Programming Clojure, Third Edition: "import" for MidiNote protocol does not work (page 186)

On page 186 (last page of chapter 7) it says “The first thing we need to do is import (not use or require) our MidiNote protocol from the examples.midi namespace”.

I could not find a reason for why import, rather than use or require, should be used in this case. I am very new to Clojure but as far as I can tell, “import” is used only for importing Java classes.

When I tried using generator.clj from the REPL by running:

user=> (require '[examples.generator :refer :all])

, the “import” did not work: I got the following error:

CompilerException java.lang.ClassNotFoundException: examples.midi.MidiNote, compiling:(examples/generator.clj:11:1)

I removed the import statement and added the following require to the ns statement at the top of generator.clj:

(:require [examples.midi :refer [MidiNote key-number perform to-msec]])

After this change I was able to run generator.clj from the REPL successfully.

Where Next?

Popular Pragmatic Bookshelf topics Top

leonW
I ran this command after installing the sample application: $ cards add do something --owner Brian And got a file not found error: Fil...
New
patoncrispy
I’m new to Rust and am using this book to learn more as well as to feed my interest in game dev. I’ve just finished the flappy dragon exa...
New
jskubick
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
jskubick
I think I might have found a problem involving SwitchCompat, thumbTint, and trackTint. As entered, the SwitchCompat changes color to hol...
New
New
oaklandgit
Hi, I completed chapter 6 but am getting the following error when running: thread 'main' panicked at 'Failed to load texture: IoError(O...
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
taguniversalmachine
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
tkhobbes
After some hassle, I was able to finally run bin/setup, now I have started the rails server but I get this error message right when I vis...
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
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
AstonJ
We have a thread about the keyboards we have, but what about nice keyboards we come across that we want? If you have seen any that look n...
New
PragmaticBookshelf
Rust is an exciting new programming language combining the power of C with memory safety, fearless concurrency, and productivity boosters...
New
Margaret
Hello content creators! Happy new year. What tech topics do you think will be the focus of 2021? My vote for one topic is ethics in tech...
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...
New
gagan7995
API 4 Path: /user/following/ Method: GET Description: Returns the list of all names of people whom the user follows Response [ { ...
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
PragmaticBookshelf
Author Spotlight Mike Riley @mriley This month, we turn the spotlight on Mike Riley, author of Portable Python Projects. Mike’s book ...
New
PragmaticBookshelf
Author Spotlight Rebecca Skinner @RebeccaSkinner Welcome to our latest author spotlight, where we sit down with Rebecca Skinner, auth...
New
First poster: bot
Large Language Models like ChatGPT say The Darnedest Things. The Errors They MakeWhy We Need to Document Them, and What We Have Decided ...
New

Sub Categories: