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
Ruby Metaprogramming
Search
Sergio Gil
March 25, 2012
Programming
11
2.7k
Ruby Metaprogramming
Slides from my talk at #codemotion #es (Madrid, March 24th 2012).
http://codemotion.es/
Sergio Gil
March 25, 2012
Tweet
Share
More Decks by Sergio Gil
See All by Sergio Gil
Understanding Unix pipes with Ruby
porras
0
180
Crystal
porras
4
330
Enumerator.is_an(Enumerable) [es]
porras
0
160
5 hidden gems of the Ruby Standard Library
porras
2
240
Enumerator is an Enumerable 💃
porras
3
130
Queue and SizedQueue: hidden gems in the Ruby standard library
porras
0
180
Laziness
porras
3
230
Standing on the shoulders of giants
porras
0
220
I used to be a writer (love letter to Ruby)
porras
2
240
Other Decks in Programming
See All in Programming
つよそうにふるまい、つよい成果を出すのなら、つよいのかもしれない
irof
1
300
レガシーシステムの機能調査・開発におけるAI利活用
takuya_ohtonari
0
610
「ElixirでIoT!!」のこれまでとこれから
takasehideki
0
370
The Evolution of Enterprise Java with Jakarta EE 11 and Beyond
ivargrimstad
1
860
関数型まつりレポート for JuliaTokai #22
antimon2
0
140
GraphRAGの仕組みまるわかり
tosuri13
7
470
イベントストーミング図からコードへの変換手順 / Procedure for Converting Event Storming Diagrams to Code
nrslib
1
200
既存デザインを変更せずにタップ領域を広げる方法
tahia910
1
240
20250628_非エンジニアがバイブコーディングしてみた
ponponmikankan
0
190
生成AIで日々のエラー調査を進めたい
yuyaabo
0
630
FormFlow - Build Stunning Multistep Forms
yceruto
1
190
Webの外へ飛び出せ NativePHPが切り拓くPHPの未来
takuyakatsusa
1
200
Featured
See All Featured
Six Lessons from altMBA
skipperchong
28
3.8k
We Have a Design System, Now What?
morganepeng
53
7.6k
Adopting Sorbet at Scale
ufuk
77
9.4k
Connecting the Dots Between Site Speed, User Experience & Your Business [WebExpo 2025]
tammyeverts
4
200
The Power of CSS Pseudo Elements
geoffreycrofte
77
5.8k
Templates, Plugins, & Blocks: Oh My! Creating the theme that thinks of everything
marktimemedia
31
2.4k
JavaScript: Past, Present, and Future - NDC Porto 2020
reverentgeek
48
5.4k
Rebuilding a faster, lazier Slack
samanthasiow
81
9k
Designing Experiences People Love
moore
142
24k
Code Reviewing Like a Champion
maltzj
524
40k
Visualization
eitanlees
146
16k
Unsuck your backbone
ammeep
671
58k
Transcript
Ruby Metaprogramming Sergio Gil (@porras)
None
require 'excel' require 'sql' Excel.load('file.xls').each do |row| SQL.insert(row) end
None
require 'html' require 'http' page = HTML.load(HTTP.get('http://example.com/')) page.links.each do |link|
HTTP.get(link).save end
class Company def projects HTTP::Request.new('/projects').get end def people HTTP::Request.new('/people').get end
def clients HTTP::Request.new('/clients').get end ... end
Yukihiro Matsumoto ‘Matz’, Ruby creator
None
Metaprogramming
defining metaprogramming
None
None
None
None
Classes Instances Methods Variables Constants Modules
Classes Instances Methods Variables Constants Modules
Memory
Classes Instances Methods Variables Constants Modules
None
>> str = "hola" => "hola"
>> str = "hola" => "hola" >> str.methods => [...,
:reverse, ...]
>> str = "hola" => "hola" >> str.methods => [...,
:reverse, ...] >> def str.reverse "adios" end
>> str = "hola" => "hola" >> str.methods => [...,
:reverse, ...] >> def str.reverse "adios" end >> str.reverse
>> str = "hola" => "hola" >> str.methods => [...,
:reverse, ...] >> def str.reverse "adios" end >> str.reverse => "adios"
Ruby Object Model: The Musical
None
None
None
None
None
It’s all about DRYness
class Company def projects HTTP::Request.new('/projects').get end def people HTTP::Request.new('/people').get end
... end
class Company def projects get('/projects') end def people get('/people') end
... private def get(url) HTTP::Request.new(url).get end end
Is that all?
Let Ruby create your methods for you
class Company [:projects, :people, ...].each do |method| eval %Q{ def
#{method} HTTP::Request.new('/#{method}').get end } end end
class Company [:projects, :people, ...].each do |method| define_method method do
HTTP::Request.new("/#{method}").get end end end
None
It’s all about expresivity
None
module HTTP def get(*methods) methods.each do |method| define_method method do
HTTP::Request.new("/#{method}").get end end end end
module HTTP def get(*methods) methods.each do |method| define_method method do
HTTP::Request.new("/#{method}").get end end end end class Company extend HTTP get :projects, :people, ... end
“I Taw a Putty DSL...”
class Company extend HTTP get :projects, :people, ... end
It’s all about flexibility
class Company def method_missing(method, *args, &blk) HTTP::Request.new("/#{method}").get end end
class Company def method_missing(method, *args, &blk) HTTP::Request.new("/#{method}").get end end
It’s all common sense
metaprogramming == programming
same trade-offs apply
None
None
None
“Cleverness cannot win. The only weapons we have are simplicity
and convention” http://alarmingdevelopment.org/?p=422
Thank you :)