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
3.2k
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
GitHub Actions × RAGでコードレビューの検証の結果
sho_000
0
280
コミュニティ駆動 AWS CDK ライブラリ「Open Constructs Library」 / community-cdk-library
gotok365
2
180
ARA Ansible for the teams
kksat
0
160
Djangoにおける複数ユーザー種別認証の設計アプローチ@DjangoCongress JP 2025
delhi09
PRO
4
400
第3回 Snowflake 中部ユーザ会- dbt × Snowflake ハンズオン
hoto17296
4
380
さいきょうのレイヤードアーキテクチャについて考えてみた
yahiru
3
770
AIの力でお手軽Chrome拡張機能作り
taiseiue
0
180
Lottieアニメーションをカスタマイズしてみた
tahia910
0
130
Code smarter, not harder - How AI Coding Tools Boost Your Productivity | Angular Meetup Berlin
danielsogl
0
100
color-scheme: light dark; を完全に理解する
uhyo
7
470
CI改善もDatadogとともに
taumu
0
180
『品質』という言葉が嫌いな理由
korimu
0
180
Featured
See All Featured
XXLCSS - How to scale CSS and keep your sanity
sugarenia
248
1.3M
Site-Speed That Sticks
csswizardry
4
390
ReactJS: Keep Simple. Everything can be a component!
pedronauck
666
120k
Put a Button on it: Removing Barriers to Going Fast.
kastner
60
3.7k
RailsConf 2023
tenderlove
29
1k
jQuery: Nuts, Bolts and Bling
dougneiner
63
7.7k
Responsive Adventures: Dirty Tricks From The Dark Corners of Front-End
smashingmag
251
21k
Practical Orchestrator
shlominoach
186
10k
The Language of Interfaces
destraynor
156
24k
Unsuck your backbone
ammeep
669
57k
Cheating the UX When There Is Nothing More to Optimize - PixelPioneers
stephaniewalter
280
13k
Designing on Purpose - Digital PM Summit 2013
jponch
117
7.1k
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