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
Snake Snacks: Function Composition, The Dumb Way
Search
Brian Hicks
September 07, 2017
Technology
0
110
Snake Snacks: Function Composition, The Dumb Way
Brian Hicks
September 07, 2017
Tweet
Share
More Decks by Brian Hicks
See All by Brian Hicks
Esperanto
brianhicks
0
120
Make Snacks: Yet Another JavaScript Build System
brianhicks
0
74
State of Elm 2017
brianhicks
1
490
µKanren: A Minimal Functional Core for Relational Programming
brianhicks
0
400
Terraform All The Things!
brianhicks
2
360
Kubernetes for the Mesos User
brianhicks
1
92
ch-ch-ch-ch-changes in Elm 0.17.0
brianhicks
2
1.8k
State of Elm 2016
brianhicks
3
510
Mesos + Consul = Developer Happiness (JUG)
brianhicks
1
120
Other Decks in Technology
See All in Technology
スキルだけでは満たせない、 “組織全体に”なじむオンボーディング/Onboarding that fits “throughout the organization” and cannot be satisfied by skills alone
bitkey
0
170
ウォンテッドリーのデータパイプラインを支える ETL のための analytics, rds-exporter / analytics, rds-exporter for ETL to support Wantedly's data pipeline
unblee
0
120
AWS Well-Architected Frameworkで学ぶAmazon ECSのセキュリティ対策
umekou
2
140
OPENLOGI Company Profile for engineer
hr01
1
20k
プロダクトエンジニア 360°フィードバックを実施した話
hacomono
PRO
0
140
NFV基盤のOpenStack更新 ~9世代バージョンアップへの挑戦~
vtj
0
340
AWSアカウントのセキュリティ自動化、どこまで進める? 最適な設計と実践ポイント
yuobayashi
7
520
偏光画像処理ライブラリを作った話
elerac
1
170
Snowflakeの開発・運用コストをApache Icebergで効率化しよう!~機能と活用例のご紹介~
sagara
1
420
Exadata Database Service on Cloud@Customer セキュリティ、ネットワーク、および管理について
oracle4engineer
PRO
2
1.5k
脳波を用いた嗜好マッチングシステム
hokkey621
0
280
php-conference-nagoya-2025
fuwasegu
0
150
Featured
See All Featured
Measuring & Analyzing Core Web Vitals
bluesmoon
6
250
How STYLIGHT went responsive
nonsquared
98
5.4k
Making Projects Easy
brettharned
116
6k
Into the Great Unknown - MozCon
thekraken
35
1.6k
How GitHub (no longer) Works
holman
314
140k
Typedesign – Prime Four
hannesfritz
40
2.5k
Building Better People: How to give real-time feedback that sticks.
wjessup
367
19k
The Art of Programming - Codeland 2020
erikaheidi
53
13k
Building Your Own Lightsaber
phodgson
104
6.2k
Raft: Consensus for Rubyists
vanstee
137
6.8k
Designing for humans not robots
tammielis
250
25k
Automating Front-end Workflow
addyosmani
1368
200k
Transcript
Snake Snacks FUNCTION COMPOSITION, THE DUMB WAY
WHAT WE WANT def inc(n): return n + 1 def
double(n): return n * 2 # in the REPL >>> (inc >> double)(2) 6 >>> (double >> inc)(2) 5
HOW ARE WE GONNA GET THERE? The Worst Way Possible™
DOUBLE UNDERSCORE METHODS
DOUBLE UNDERSCORE METHODS
DUNDER METHODS
DUNDER MIFFLIN
DUNDER METHODS, THE NICE WAY class Boss(object): def __init__(self, name):
self.name = name def __str__(self): return self.name def __repr__(self): return '<%s: %s>' % (self.__class__.__name__, self) def introduce(self): return "Please meet my boss, %s" % self
DUNDER METHODS, THE NICE WAY >>> b = Boss("Michael Scott")
>>> b <Boss: Michael Scott> >>> str(b) 'Michael Scott' >>> b.introduce() 'Please meet my boss, Michael Scott'
! DECORATORS "
DECORATORS, THE NICE WAY def memoize(fn): cache = {} def
inner(*args, **kwargs): key = str((args, kwargs)) if key not in cache: cache[key] = fn(*args, **kwargs) return cache[key] return inner
DECORATORS, THE NICE WAY @memoize def hype(stuff): return "OH YEAH,
IT'S %s" % stuff.upper() # is the same as... hype = memoize(lambda stuff: "OH YEAH, IT'S %s" % stuff.upper())
DECORATORS, THE NICE WAY >>> hype("cheese") "OH YEAH, IT'S CHEESE"
>>> hype("a moose") "OH YEAH, IT'S A MOOSE"
BUT… OBJECTS! class memoize(object): def __init__(self, fn): self.cache = {}
self.fn = fn def __call__(self, *args, **kwargs): key = str((args, kwargs)) if key not in self.cache: self.cache[key] = self.fn(*args, **kwargs) return self.cache[key]
BUT… OBJECTS! >>> hype("cheese") "OH YEAH, IT'S CHEESE" >>> hype("a
moose") "OH YEAH, IT'S A MOOSE" >>> hype.cache {"(('a moose',), {})": "OH YEAH, IT'S A MOOSE", "(('cheese',), {})": "OH YEAH, IT'S CHEESE"}
__gt__ class ChessPlayer(object): def __init__(self, name, elo): self.name = name
self.elo = elo def __gt__(self, other): return self.elo > other.elo
__gt__ >>> carlsen = ChessPlayer("Carlsen, Magnus", 2827) >>> almasi =
ChessPlayer("Almasi, Zoltan", 2707) >>> carlsen > almasi True >>> carlsen < almasi False
OUR FIRST TRY! class composable(object): def __init__(self, fn): self.fn =
fn def __call__(self, *args, **kwargs): return self.fn(*args, **kwargs) def __gt__(self, other): return self.__class__( lambda *args, **kwargs: other(self.fn(*args, **kwargs)) )
OUR FIRST TRY! @composable def inc(n): return n + 1
@composable def double(n): return n * 2 @composable def triple(n): return n * 3
OUR FIRST TRY! >>> (inc > inc)(0) 2 >>> (inc
> inc > inc)(0) 2
OUR FIRST TRY! ! 1 > 2 > 3 #
is equivalent to 1 > 2 and 2 > 3 # NOT (1 > 2) > 3
__rshift__ TO THE RESCUE! class composable(object): def __init__(self, fn): self.fn
= fn def __call__(self, *args, **kwargs): return self.fn(*args, **kwargs) def __rshift__(self, other): return self.__class__( lambda *args, **kwargs: other(self.fn(*args, **kwargs)) )
__rshift__ TO THE RESCUE! >>> (inc >> inc)(0) 2 >>>
(inc >> inc >> inc)(0) 3
__rshift__ TO THE RESCUE! >>> (inc >> double)(2) 6 >>>
(double >> inc)(2) 5 >>> (inc >> double >> triple)(2) 18
THANK YOU I'M SORRY