Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Elegant Objects and Cactoos
Search
Filipe Freire
December 21, 2017
Programming
0
190
Elegant Objects and Cactoos
Overview of the EO paradigm and small overview of the Cactoos library for Porto Codes Meetup
Filipe Freire
December 21, 2017
Tweet
Share
More Decks by Filipe Freire
See All by Filipe Freire
Deep Testing
filipe
0
75
Finding Tranquility
filipe
0
67
Quality Foundations
filipe
0
60
Tacit CSS Framework
filipe
0
250
Quality from the start
filipe
0
110
Tacit
filipe
0
130
Waiting is boring
filipe
0
390
You don't need a DevOps to "be DevOps"
filipe
0
260
Other Decks in Programming
See All in Programming
入門 AWS Amplify Gen2 / Introduction to AWS Amplify Gen2
genkiogasawara
1
330
コードレビューで学ぶ!Kotlinオブジェクト指向デザインパターン
akkie76
2
200
スキーマ駆動開発による品質とスピードの両立 - 私達は何故、スキーマを書くのか
kentaroutakeda
0
170
Rubyでたのしむクリエイティブコーディング/Enjoy Creative coding with Ruby
chobishiba
1
180
Tailwind CSSを本気でカスタマイズする方法
fsubal
13
5.2k
Azure OpenAI Serviceのプロンプトエンジニアリング入門
tomokusaba
3
670
大規模Reactアプリのリアーキテクチャ~8万行のTanStack Query移行の軌跡~
kj455
4
940
Komplexe Oberflächen mit SVG und der Web Animation API
joergneumann
0
670
if constexpr文はテンプレート世界のラムダ式である
faithandbrave
3
640
Fragment Composition of GraphQL
quramy
3
400
VS Code をプロダクトにどう取り込むか
onomax
1
350
Rethinking UI building strategies @ SFI 2024
letelete
0
270
Featured
See All Featured
What's new in Ruby 2.0
geeforr
337
31k
Refactoring Trust on Your Teams (GOTO; Chicago 2020)
rmw
25
2.3k
Ruby is Unlike a Banana
tanoku
96
10k
Bootstrapping a Software Product
garrettdimon
PRO
302
110k
Mobile First: as difficult as doing things right
swwweet
216
8.6k
Six Lessons from altMBA
skipperchong
21
3k
Large-scale JavaScript Application Architecture
addyosmani
504
110k
Into the Great Unknown - MozCon
thekraken
10
990
A Philosophy of Restraint
colly
197
16k
The Power of CSS Pseudo Elements
geoffreycrofte
60
5k
Adopting Sorbet at Scale
ufuk
68
8.6k
Optimising Largest Contentful Paint
csswizardry
8
2.4k
Transcript
Elegant objects & Cactoos Filipe Freire 21 December 2017
Quick intro Learner, tester, developer, husband OSS contributor 2y work
as a “coding” tester 1y work as a developer Currently @ filfreire.com 2
Elegant Objects 3
It’s an OOP paradigm 4
Book Yegor Bugayenko @yegor256 www.yegor256.com 5
Book Yegor Bugayenko @yegor256 www.yegor256.com Set of recommendations: - Cleaner
code - Better classes - Visible architecture 6
Disclaimer: You can find out more at yegor256.com Youtube @yegor256
and on the EO books. 7
So, what are the recommendations? 8
Getters Setters Mutable objects Static methods Annotations Data Objects Type
Casting Etc. 9
Getters Setters Mutable objects Static methods Annotations Data Objects Type
Casting Etc. 10
Don’t treat objects as data structures bags of data.
Ever. 11
Maintainability > everything else 12
“Objects as living beings” Birth Working life Retirement 13
Some examples… 14
Birth 15
Code Free Constructors 16
17
“Object’s name != job title” 18
Object’s name != job title Meaning: Avoid the use of
“-ER” 19
Helper, Handler, Writer, Reader, Converter, Observer, Listener, Sorter, Encoder, Decoder,
… 20
Helper, Handler, Writer, Reader, Converter, Observer, Listener, Sorter, Encoder, Decoder,
… 21
An object isn’t: 1) A link between worlds 2) A
collection of procedures plus data 22
An object is: 1) Self-sufficient 2) Representative of encapsulated
data 23
A Finder of Prime Numbers vs A List of numbers
that returns only primes 24
Education & Work life 25
No Getters and Setters. Not even once. 26
No Getters and Setters ?! ?! 27
Again, don’t treat objects as bags of data. Ever.
28
Computer-style: 29
Human-style: 30
“An object works by contracts” 31
“An object works by contracts” Always use interfaces 32
Example “I want results for a Tennis match” Tennis_31Feb.xlsx TENNIS.txt
tennis_res.json Sources: … 33
Example “I want results for a Tennis match” Tennis_31Feb.xlsx TENNIS.txt
tennis_res.json Sources: … ExcelTennisMatch TextTennisMatch JsonTennisMatch 34
Example “I want results for a Tennis match” ExcelTennisMatch TextTennisMatch
JsonTennisMatch TennisMatch GameMatch implement extends 35
Excel, Text, Json, etc. Contract stays the same More Decoupling
and more Maintainability 36
“A good object should never change his encapsulated state.” 37
“A good object should never change his encapsulated state.” 38
Be immutable
This can change State is the same 39
Some benefits Thread Safety Avoiding Temporal Coupling Avoiding side effects
Avoiding identity mutability (more at http://yegor256.com/2014/06/09/objects-should-be-immutable.html) 40
Retirement 41
Don’t accept null arguments Don’t return null 42
- Hello, is it a software department? - Yes. -
Let me talk to your employee "Jeffrey" please. - Hold the line please... - Hello. - … 43
- Hello, is it a software department? - Yes. -
Let me talk to your employee "Jeffrey" please. - Hold the line please... - Hello. - Are you NULL? (more at http://www.yegor256.com/2014/05/13/why-null-is-bad.html) 44
There’s more to it, Let’s save it for another talk
45
https://github.com/yegor256/cactoos 46
Useful building blocks from Guava, Apache Commons, JDK + EO
paradigm 47
Meaning… No null No code in constructors No getters and
setters No mutable objects No static methods, not even private ones (among other stuff) 48
Example 1 49
Example 2 50
Example 3 51
Summing up 52
Maintainability 53
–W. Edwards Deming "Build quality into the product rather than
trying to test it in later." 54
Quality from the start Force strict control of code quality.
Ex: Static Analysis -> mandatory 55
Thank you. Questions? filfreire filrfreire filfreire.com 56