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
290
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
100
Finding Tranquility
filipe
0
89
Quality Foundations
filipe
0
96
Tacit CSS Framework
filipe
0
340
Quality from the start
filipe
0
140
Tacit
filipe
0
160
Waiting is boring
filipe
0
570
You don't need a DevOps to "be DevOps"
filipe
0
320
Other Decks in Programming
See All in Programming
プログラミング教育のコスパの話
superkinoko
0
100
もっと大きなデータを送りませんか? エラーがゴロゴロ出るようなデータです
sublimer
0
170
Devin , 正しい付き合い方と使い方 / Living and Working with Devin
yukinagae
1
470
보일러플레이트 코드가 진짜 나쁜 건가요?
gaeun5744
0
340
ステートソーシング型イベント駆動の視点で捉えるCQRS+ES
shinnosuke0522
0
270
安全に倒し切るリリースをするために:15年来レガシーシステムのフルリプレイス挑戦記
sakuraikotone
5
1.9k
AtCoder Heuristic First-step Vol.1 講義スライド
terryu16
2
690
Compose Navigation実装の見通しを良くする
hiroaki404
0
120
PHPによる"非"構造化プログラミング入門 -本当に熱いスパゲティコードを求めて- #phperkaigi
o0h
PRO
0
700
RailsでCQRS/ESをやってみたきづき
suzukimar
2
1.4k
ニックトレイン登壇資料
ryotakurokawa
0
120
신입 안드로이드 개발자의 AI 스타트업 생존기 (+ Native C++ Code를 Android에서 사용해보기)
dygames
0
460
Featured
See All Featured
CoffeeScript is Beautiful & I Never Want to Write Plain JavaScript Again
sstephenson
160
15k
Why Our Code Smells
bkeepers
PRO
336
57k
Understanding Cognitive Biases in Performance Measurement
bluesmoon
27
1.6k
Facilitating Awesome Meetings
lara
53
6.3k
Docker and Python
trallard
44
3.3k
GitHub's CSS Performance
jonrohan
1030
460k
The Invisible Side of Design
smashingmag
299
50k
How to train your dragon (web standard)
notwaldorf
91
5.9k
It's Worth the Effort
3n
184
28k
Reflections from 52 weeks, 52 projects
jeffersonlam
349
20k
Visualization
eitanlees
146
15k
Six Lessons from altMBA
skipperchong
27
3.7k
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