dtonhofer
Functional Programming in Java, Second Edition: p. 55 "Compare.java" can be further simplified
On page 55, we see Compare.java
final Function<Person, String> byName = person -> person.getName();
people.stream()
.sorted(comparing(byName));
However, this can be further simplified to:
people.stream()
.sorted(comparing(Person::getName));
On the same page, more from Compare.java:
final Function<Person, Integer> byAge = person -> person.getAge();
final Function<Person, String> byTheirName = person -> person.getName();
printPeople("Sorted in ascending order by age, then name: ",
people.stream()
.sorted(comparing(byAge).thenComparing(byTheirName))
.collect(toList());
which can be simplified similarly to:
printPeople("Sorted in ascending order by age, then name: ",
people.stream()
sorted(comparing(Person::getAge).thenComparing(Person::getName))
.collect(toList());
but which would be even better by separating the list generation and output tasks:
List<Person> asc =
people.stream()
.sorted(comparing(Person::getAge).thenComparing(Person::getName))
.collect(toList());
printPeople("Sorted in ascending order by age, then name: ", asc);
…all according to the JavaDoc for Comparator:
P.S.
Would it be clearer to explicitly write the class from which comparing() comes instead of assuming it has been imported statically? Like this:
people.stream()
.sorted(Comparator.comparing(Person::getName));
instaed of
people.stream()
.sorted(comparing(Person::getName));
Note that the collect()call
people.stream()
.sorted(comparing(byAge).thenComparing(byTheirName))
.collect(toList()));
…also assume a statically imported toList(). On the other hand, compare/fpij/OlderThan20.java on page 58 is explicit:
List<Person> olderThan20 =
people.stream()
.filter(person -> person.getAge() > 20)
.collect(Collectors.toList());
Popular Pragmatic Bookshelf topics
page 20: … protoc command…
I had to additionally run the following go get commands in order to be able to compile protobuf code using go...
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
A Common-Sense Guide to Data Structures and Algorithms, Second Edition by Jay Wengrow @jaywengrow
Hi,
I have the paperback version of t...
New
Dear Sophie.
I tried to do the “Authorization” exercise and have two questions:
When trying to plug in an email-service, I found the ...
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
This is as much a suggestion as a question, as a note for others.
Locally the SGP30 wasn’t available, so I ordered a SGP40. On page 53, ...
New
The allprojects block listed on page 245 produces the following error when syncing gradle:
“org.gradle.api.GradleScriptException: A prob...
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
@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
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
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...
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
This looks like a stunning keycap set :orange_heart:
A LEGENDARY KEYBOARD LIVES ON
When you bought an Apple Macintosh computer in the e...
New
Small essay with thoughts on macOS vs. Linux:
I know @Exadra37 is just waiting around the corner to scream at me “I TOLD YOU SO!!!” but I...
New
Use WebRTC to build web applications that stream media and data in real time directly from one user to another, all in the browser.
...
New
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...
New
Programming Ruby is the most complete book on Ruby, covering both the language itself and the standard library as well as commonly used t...
New
zig/http.zig at 7cf2cbb33ef34c1d211135f56d30fe23b6cacd42 · ziglang/zig.
General-purpose programming language and toolchain for maintaini...
New
Jan | Rethink the Computer.
Jan turns your computer into an AI machine by running LLMs locally on your computer. It’s a privacy-focus, l...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /wasm
- /ruby
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /java
- /emacs
- /haskell
- /svelte
- /typescript
- /onivim
- /kotlin
- /c-plus-plus
- /crystal
- /tailwind
- /react
- /gleam
- /ocaml
- /elm
- /flutter
- /ash
- /vscode
- /html
- /opensuse
- /zig
- /centos
- /deepseek
- /php
- /scala
- /react-native
- /lisp
- /textmate
- /sublime-text
- /nixos
- /debian
- /agda
- /django
- /deno
- /kubuntu
- /arch-linux
- /nodejs
- /spring
- /revery
- /ubuntu
- /manjaro
- /lua
- /diversity
- /julia
- /markdown
- /c









