dtonhofer
Functional Programming in Java, Second Edition: Chapter 3: Add an example of a filter negation
The filter stream operation appears on several places in Chapter 2 and Chapter 3, so it’s difficult to say where to put this, but there should be an example of “filtering by a negated predicate”, maybe on page 60:
The code presented:
Files.list(Paths.get("."))
.filter(Files::isDirectory)
.forEach(System.out::println);
But what if we want to have everything EXCEPT directories while using the method reference?
This would of course work:
Files.list(Paths.get("."))
.filter(file -> !Files.isDirectory(file))
.forEach(System.out::println);
But nicer is this application of “predicate composition”
Files.list(Paths.get("."))
.filter(Predicate.not(file -> Files.isDirectory(file)))
.forEach(System.out::println);
which simplifies to
Files.list(Paths.get("."))
.filter(Predicate.not(Files::isDirectory))
.forEach(System.out::println);
Popular Pragmatic Bookshelf topics
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
The following is cross-posted from the original Ray Tracer Challenge forum, from a post by garfieldnate. I’m cross-posting it so that the...
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
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...
New
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
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
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...
New
@parrt
In the context of Chapter 4.3, the grammar Java.g4, meant to parse Java 6 compilation units, no longer passes ANTLR (currently 4....
New
I am using Android Studio Chipmunk | 2021.2.1 Patch 2
Build #AI-212.5712.43.2112.8815526, built on July 10, 2022
Runtime version: 11.0....
New
Getting an error when installing the dependencies at the start of this chapter:
could not compile dependency :exla, "mix compile" failed...
New
Other popular topics
Hello Devtalk World!
Please let us know a little about who you are and where you’re from :nerd_face:
New
Curious to know which languages and frameworks you’re all thinking about learning next :upside_down_face:
Perhaps if there’s enough peop...
New
New
Do the test and post your score :nerd_face:
:keyboard:
If possible, please add info such as the keyboard you’re using, the layout (Qw...
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
Author Spotlight
Rebecca Skinner
@RebeccaSkinner
Welcome to our latest author spotlight, where we sit down with Rebecca Skinner, auth...
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
Hair Salon Games for Girls Fun
Girls Hair Saloon game is mainly developed for kids. This game allows users to select virtual avatars to ...
New
Use advanced functional programming principles, practical Domain-Driven Design techniques, and production-ready Elixir code to build scal...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /wasm
- /ruby
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /emacs
- /java
- /haskell
- /svelte
- /onivim
- /typescript
- /kotlin
- /c-plus-plus
- /crystal
- /tailwind
- /react
- /gleam
- /ocaml
- /flutter
- /elm
- /vscode
- /ash
- /html
- /opensuse
- /zig
- /centos
- /deepseek
- /php
- /scala
- /react-native
- /lisp
- /sublime-text
- /textmate
- /nixos
- /debian
- /agda
- /django
- /deno
- /kubuntu
- /arch-linux
- /nodejs
- /revery
- /ubuntu
- /manjaro
- /spring
- /lua
- /diversity
- /julia
- /markdown
- /slackware









