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
RecordDotSyntaxのあれこれ
Search
lotz
December 11, 2019
Programming
2
1.1k
RecordDotSyntaxのあれこれ
lotz
December 11, 2019
Tweet
Share
More Decks by lotz
See All by lotz
Recursion Schemesで考える並べ替えアルゴリズム
lotz84
6
2k
関数と型で理解する自動微分
lotz84
6
3k
Other Decks in Programming
See All in Programming
リバースエンジニアリング新時代へ! GhidraとClaude DesktopをMCPで繋ぐ/findy202507
tkmru
3
970
商品比較サービス「マイベスト」における パーソナライズレコメンドの第一歩
ucchiii43
0
180
ご注文の差分はこちらですか? 〜 AWS CDK のいろいろな差分検出と安全なデプロイ
konokenj
3
580
ニーリーにおけるプロダクトエンジニア
nealle
0
950
Python型ヒント完全ガイド 初心者でも分かる、現代的で実践的な使い方
mickey_kubo
1
240
チームのテスト力を総合的に鍛えて品質、スピード、レジリエンスを共立させる/Testing approach that improves quality, speed, and resilience
goyoki
5
1.1k
NEWT Backend Evolution
xpromx
1
140
AI コーディングエージェントの時代へ:JetBrains が描く開発の未来
masaruhr
1
200
おやつのお供はお決まりですか?@WWDC25 Recap -Japan-\(region).swift
shingangan
0
140
型で語るカタ
irof
0
700
状態遷移図を書こう / Sequence Chart vs State Diagram
orgachem
PRO
2
210
SQLアンチパターン第2版 データベースプログラミングで陥りがちな失敗とその対策 / Intro to SQL Antipatterns 2nd
twada
PRO
15
2k
Featured
See All Featured
Build your cross-platform service in a week with App Engine
jlugia
231
18k
Imperfection Machines: The Place of Print at Facebook
scottboms
267
13k
CSS Pre-Processors: Stylus, Less & Sass
bermonpainter
357
30k
BBQ
matthewcrist
89
9.7k
Visualizing Your Data: Incorporating Mongo into Loggly Infrastructure
mongodb
47
9.6k
The Success of Rails: Ensuring Growth for the Next 100 Years
eileencodes
45
7.5k
Code Review Best Practice
trishagee
69
19k
The Pragmatic Product Professional
lauravandoore
35
6.7k
Site-Speed That Sticks
csswizardry
10
700
Mobile First: as difficult as doing things right
swwweet
223
9.7k
Fantastic passwords and where to find them - at NoRuKo
philnash
51
3.3k
Intergalactic Javascript Robots from Outer Space
tanoku
271
27k
Transcript
Record Dot Syntax ͷ͋Ε͜Ε By lotz 2019/12/11 ୈ2ճGHCษڧձ @ IIJ-II
RecordDotSyntax https://github.com/shayne-fletcher-da/ghc-proposals/blob/record-dot-syntax/proposals/0000-record-dot-syntax.md#motivation
RecordDotSyntaxͷجຊ https://github.com/shayne-fletcher-da/ghc-proposals/blob/record-dot-syntax/proposals/0000-record-dot-syntax.md#recorddotsyntax-language-extension
RecordDotSyntaxͷੜߏจ https://github.com/shayne-fletcher-da/ghc-proposals/blob/record-dot-syntax/proposals/0000-record-dot-syntax.md#recorddotsyntax-language-extension
Recordվળͷ্ʹ͋Δ ()$֦ு1SPQPTBM ()$7FSTJPO %VQMJDBUF3FDPSE'JFMET 0WFSMPBEFE-BCFMT 0WFSMPBEFE3FDPSE'JFMET "EETFU'JFMEUP)BT'JFME
/P'JFME4FMFDUPST "DDFQUFE 3FDPSE%PU4ZOUBY /&8
DAMLͰͷ࣮͋Γ • DAMLHaskell/ScalaͰ։ൃ͞Ε͍ͯΔɺ εϚʔτίϯτϥΫτهड़ݴޠ • DAMLͷ։ൃʹ͓͍ͯGHC Pluginsͱ͍͏ܗͰ RecordDotSyntaxͱ΄΅ಉ͡ػೳ͕ΘΕ͍ͯΔ
ఏҊͯ͠ΔͷDAMLͷਓ https://github.com/ghc-proposals/ghc-proposals/pull/282
PRͷԠ https://github.com/ghc-proposals/ghc-proposals/pull/282#issuecomment-540968106 *TUSPOHMZTVQQPSUUIFEJSFDUJPOPG USBWFMPGUIJTQSPQPTBM
PRͷԠ 5IFMPTTPGQPMZNPSQIJDVQEBUFJT BIVHFQSPCMFN JNP https://github.com/ghc-proposals/ghc-proposals/pull/282#issuecomment-541111003
PRͷԠ 5IJTQSPQPTBMJTGVMMPGVUUFSOPOTFOTF https://github.com/ghc-proposals/ghc-proposals/pull/282#issuecomment-541460439
> :t (.age) (.age) :: Person -> Int > :t
(. age) (. age) :: (Int -> c) -> Person -> c ۭനͷ༗Γແ͠Ͱ͜͜·Ͱҙຯ͕มΘΔͷ ॳ৺ऀʹ͘͠ͳ͍ʁ
ࠓͷεςʔλε https://github.com/ghc-proposals/ghc-proposals/pull/282#issuecomment-559259994 8JUIUIFUIDPNNFOU BGUFSSFBDUJPOTPOUIFJOJUJBM QPTU QBSUJDJQBOUTBOEBUMFBTUQPMMTPGVTFSTFOUJNFOU *EMJLFUPUVSOUIJTPWFSUPUIFDPNNJUUFF
ະղܾ https://twitter.com/ndm_haskell/status/1190680324495302658
͋Ε͜Ε
f a.b.c x ͷύʔε f a.foo.bar.baz.quux 12 f (a.foo.bar.baz.quux)
12 ͱධՁ͞ΕΔ ((f a).foo.bar.baz.quux) 12Ͱͳ͍ https://github.com/shayne-fletcher-da/ghc-proposals/blob/record-dot-syntax/proposals/0000-record-dot-syntax.md#record-selection
Lensʁ • f $ record ^. field ͕ f record.field
ͱॻ͚Δ • Lensෳࡶա͗Δ… • Lensͱ໊લۭ͕ؒҟͳΔͷͰҰॹʹ͑Δ https://github.com/shayne-fletcher-da/ghc-proposals/blob/record-dot-syntax/proposals/0000-record-dot-syntax.md#alternatives-to-this-proposal
͜͏͍͏දهແ͍ • ߋ৽ʹؔ͢Δߏจ • a{field * 2} • a{field <-
(*2)} • a{field * = 2} • ߋ৽ʹؔ͢ΔηΫγϣϯ • ({a=}) • ({a=b}) • (.lbl=) https://github.com/shayne-fletcher-da/ghc-proposals/blob/record-dot-syntax/proposals/0000-record-dot-syntax.md#alternatives-within-this-proposal
Ҏ্