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
Goに無名関数の糖衣構文いれたらどうなるの? / Considering the introd...
Search
yuroyoro
October 28, 2019
Programming
4
3.5k
Goに無名関数の糖衣構文いれたらどうなるの? / Considering the introduction of the anonymous function syntax sugar into Go
GoCon 2019 LT
yuroyoro
October 28, 2019
Tweet
Share
More Decks by yuroyoro
See All by yuroyoro
関数の話
yuroyoro
20
18k
Scala で 作る奇妙なプログラミング言語??
yuroyoro
4
16k
Other Decks in Programming
See All in Programming
Serena MCPのすすめ
wadakatu
4
1k
デミカツ切り抜きで面倒くさいことはPythonにやらせよう
aokswork3
0
250
Devvox Belgium - Agentic AI Patterns
kdubois
1
130
あなたとKaigi on Rails / Kaigi on Rails + You
shimoju
0
170
Go言語はstack overflowの夢を見るか?
logica0419
0
370
AI Agent 時代的開發者生存指南
eddie
3
1.8k
非同期jobをtransaction内で 呼ぶなよ!絶対に呼ぶなよ!
alstrocrack
0
980
What Spring Developers Should Know About Jakarta EE
ivargrimstad
0
210
アメ車でサンノゼを走ってきたよ!
s_shimotori
0
230
技術的負債の正体を知って向き合う
irof
0
180
タスクの特性や不確実性に応じた最適な作業スタイルの選択(ペアプロ・モブプロ・ソロプロ)と実践 / Optimal Work Style Selection: Pair, Mob, or Solo Programming.
honyanya
3
180
『毎日の移動』を支えるGoバックエンド内製開発
yutautsugi
2
250
Featured
See All Featured
[RailsConf 2023] Rails as a piece of cake
palkan
57
5.9k
Save Time (by Creating Custom Rails Generators)
garrettdimon
PRO
32
1.6k
Bootstrapping a Software Product
garrettdimon
PRO
307
110k
Easily Structure & Communicate Ideas using Wireframe
afnizarnur
194
16k
How to Think Like a Performance Engineer
csswizardry
27
2k
The Art of Programming - Codeland 2020
erikaheidi
56
14k
How to Ace a Technical Interview
jacobian
280
24k
Creating an realtime collaboration tool: Agile Flush - .NET Oxford
marcduiker
34
2.3k
We Have a Design System, Now What?
morganepeng
53
7.8k
Intergalactic Javascript Robots from Outer Space
tanoku
273
27k
Fireside Chat
paigeccino
40
3.7k
Designing Dashboards & Data Visualisations in Web Apps
destraynor
231
53k
Transcript
Considering the introduction of the anonymous function syntax sugar into
Go !ZVSPZPSP (Pʹແ໊ؔͷҥߏจ͍ΕͨΒͲ͏ͳΔͷʁ
(Pͷແ໊ؔ var f = func(x int) int { return x
* 2 }
͍ΘΏΔ"SSPX'VODUJPO͕΄͍͠ var f = (x int) int => { return
x * 2 }
ಈతܕ͖ͳݴޠͰʁ const f = (x) => { return x *
2 } +BWB4DSJQU 1ZUIPO f = lambda x: x * 2 3VCZ f = ->(x) { x * 2 }
੩తܕ͖ͳݴޠͰʁ const f = (x:number): number => { return x
* 2 } 5ZQF4DSJQU +BWB 4DBMB Function<Integer, Integer> f = (Integer x) -> { return x * 2; }; val f: (Int) => Int = (x) => { x * 2 }
(PͰ͜ΜͳܗͷߏจʹͳΓͦ͏ (name type, …) type => { function body }
ྫ͑͜Μͳ;͏ʹ (x int) int => { return x * 2
}
(PίϯύΠϥΛվ͠Α͏ʂ src/cmd/compile/ https://github.com/golang/go
ίϯύΠϥʹͭͷϑΣʔζ͕͋Δ 1. Parsing 2. Type-checking and AST transformations 3. Generic
SSA 4. Generating machine code TSDDNEDPNQJMF3&"%.&NE
ҥߏจͷՃͳͷͰɺ1BSTFSΛมߋ 1. Parsing 2. Type-checking and AST transformations 3. Generic
SSA 4. Generating machine code TSDDNEDPNQJMF3&"%.&NE
(Pͷߏจղੳ LL(1)
͍͍ͤͥͻͱͭઌͷτʔΫϯ͔͠ઌಡΈ͠ͳ͍ var f = ( x * 2 ) ↑
current: ( : _Lparen next : x : _Name
ͷ࣍ʹ໊લ͕དྷͨΒɺࣜ &YQS ʹܾ·Δ var f = ( x * 2
) ↑ current: ( : _Lparen next : x : _Name Expr
"SSPX'VODUJPO͕ೖΔͱʜʜ var f = ( x int ) int =>
{ … } ↑ current: ( : _Lparen next : x : _Name
ͷ࣍ʹ໊લ͕དྷͯɺࣜ &YQS ͔ؔ 'VOD5ZQF ͔ Θ͔Βͳ͍ var f = (
x int ) int => { … } ↑ current: ( : _Lparen next : x : _Name Expr or FuncType?
Ͳ͏ʹ͔ͳΒͳ͍
ߏจΛม͑ͯΈΑ͏ ->(name type, …) type { function body }
3VCZͬΆ͘ ͜ΕͳΒύʔεͰ͖Δͧ ->(x int) int => { return x *
2 }
AGVODAΛAAʹม͑Δ͚ͩ ->(x int) int => { return x * 2
} func(x int) int => { return x * 2 } ↓
ॻ͍ͯΈͨ src/cmd/compile/internal/syntax/parser.go | 2 +- src/cmd/compile/internal/syntax/scanner.go | 7 ++++++- src/cmd/compile/internal/syntax/token_string.go
| 4 ++-- src/cmd/compile/internal/syntax/tokens.go | 1 + 4 files changed, 10 insertions(+), 4 deletions(-)
ؔͷܕͰ͔͚ΔΑ͏ʹ͠Α͏ var f: ->(int) int = ->(x int) int {
return x * 2 }
%FNP package main import "fmt" func main() { f :=
->(x int, y int) int { return x + y } fmt.Printf("%d\n", f(3, 4)) fmt.Printf("%d", higherFunc(f)) } func higherFunc(f ->(x int, y int) int) int { return f(1, 2) }
Ͱɺ͑ͦ͏ʁ
ΈΜͳେ͖IUUQ4FSWFS http.HandleFunc("/", ->(w http.ResponseWriter, r *http.Request) { ... })
͠(Pʹ(FOFSJDT͕ೖͬͨΒ var arr = [1, 2, 3] arr.map( ->(x int)
int { return x * 2 })
AGVODAΑΓจࣈݮͬͨ
͋Μ·ΓมΘΒͳ͍ͷͰʜʜ
ͨͱ͑ɺ+BWBͰҾͷܕએݴΛ লུͰ͖Δ ↓ +BWB Function<Integer, Integer> f = (Integer x)
-> { return x * 2; }; Function<Integer, Integer> f = (x) -> { return x * 2; };
4DBMBͰฦΓܕΛਪͯ͘͠ΕΔ ↓ 4DBMB val f: Int => Int = (x:
Int) => { x * 2 } val f = (x: Int) => { x * 2 }
SFUVSOΛলུͰ͖Δݴޠଟ͍ ↓ +BWB Function<Integer, Integer> f = (x) -> {
return x * 2; }; Function<Integer, Integer> f = (x) -> { x * 2; };
͕ؔΘΕΔॴͷܕ͕Θ͔͍ͬͯΔ߹ ؔࣗମͷҾฦΓΛলུͰ͖Δ 4DBMB val arr = Array(1, 2) // Array<Int>#mapͷҾ
// (Int) => AͳͷͰҾ͕Intͱਪɺ // ؔຊମ͔ΒฦΓ͕Intͱਪ arr.map((x) => { x * 2 })
ແ໊Ҿ1MBDFIPMEFSͳͲɺ ͬͱলུͰ͖Δֻ͚ʜ 4DBMB val arr = Array(1, 2) // ແ໊ؔͷҾΛ
_ Ͱड͚Δ arr.map(_ * 2)
ແ໊ؔΛ؆ܿ໌ྎʹॻͨ͘Ίʹ ҥߏจͷଞʹ֤छͷলུه๏ - Argument Type Inference - Return Type Inference
- implicit return statement - anonymous argument placeholder
ͦͦͦ͜·Ͱলུ͍ͨ͠
Α͏͢Δʹ Conclusion
ؾ࣋ͪΑ͘ແ໊ؔΛॻͨ͘Ίʹ ߟ͑Δ͜ͱ͕ଟ͍ - Syntax - Type Inference - etc
(Pʹ͋ͬͨจ๏ͲΜͳܗ͕Α͍͔ɺ Ұॹʹߟ͑ͯΈ·ͤΜ͔