babel7とTC39のproposalをゴチャマゼで!

Transcript

1. 2.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Ba a 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53 camp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22 53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Na 2.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Ba a 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53 camp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22 53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Na 2.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Ba a 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53 camp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22 53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Na 2.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Ba a 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53 camp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22 53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Na 2.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Ba a 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53 camp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22 53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Na 2.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Ba a 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53 camp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22 53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Na 2.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Ba a 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53 camp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22 53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Na 2.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Ba a 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53 camp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22 53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Na 2.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Ba a 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53 camp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22 53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Na 2.0"N 136°53’14.7"E Basecamp Nagoya 35°10'22.0"N 136°53’14.7"E Ba Nagoya 35°10'22.0"N 136°53’14.7"E Basecamp Nagoya CBCFMͱ5$ͷ QSPQPTBMΛΰνϟϚθͰʂ 
   !
   /BHPZBKT
   
2. "HFOEB  Θͨ͘͠ʹ͍ͭͯ
    CBCFM͕ʹͳͬͨ
    ͜ͷػձʹTUBHF9Λݟ͍ͯ͜͏
    ͦͷଞؾʹͳΔωλ
    ͓·͚
3. Θͨ͘͠ʹ͍ͭͯ { "@context": "http://schema.org", "@type": "Person", "name": "Kyousuke Abe", "alternateName": "安部亨佑", "birthPlace": "Iwata, Shizuoka", "birthDate": "1982.9.24", "height": "181 cm", "weight": "68 kg", "gender": "male", "worksFor": "FRAME LUNCH Inc.", "workLocation": "Ohsu, Nagoya-shi”, "jobTitle": "Web engineer", "nationality": "Japanese", "url": "https://kaave.github.io", "sameAs": [ "https://twitter.com/junkjunctions", "https://github.com/kaave" ] } { "likes": [ "Vim-style key binding", "Emacs-style key binding", "ErgoDox", "Macbook Pro", "TypeScript", "React", "PostCSS", "fish shell", "Twitter", "Music", "Football", "Casual cycling”, "Bodyweight Workout", "Spicy foods", "Dried fruit", "American coffee" ] }
4. CBCFM͕ʹͳͬͨ
5. ઴͕͘ग़ͨ  ओͳʜͱ͍͏͔
 ๻͕ோΊͯ΄ʔΜͱࢥͬͨมߋ఺  4DPQFE
   NPEVMF ໊લۭؒ Խ
    es20XX͕ऴྃ preset-envʹू໿
    stage-X͕ऴྃ
    5ZQF4DSJQU ҰԠ ରԠ
    zbabel.config.jszͰ΋ઃఆͰ͖ΔΑ͏ʹ ˠৄࡉ͸ϚΠάϨʔγϣϯΨΠυ͓͢͢Ί
6. ৽نҊ݅ -1 Ͱૣ଎  ͬ͟ͱશ෦ʹͨ͠
    ઃఆϑΝΠϧΛzbabel.config.jsz΁
    process.env.NODE_ENV === ‘production`͕ͱ ΕΔ
    preset-env + polyfillͷઃఆมߋ
    useBuiltIns: ‘usage’
   ʜ͸࢒೦ϋϚͬͨͷ Ͱ‘entry`΁
7. ·͊؆୯ͩ͠ɺ
 ͸΍Ίʹ΍ͬͱ͖·͠ΐ͏ʂ
 ੾Ӌ٧·Δલʹʂ
8. ͜ͷػձʹ
   TUBHF9Λݟ͍ͯ͜͏
9. ˞CBCFMެࣜϓϥάΠϯͷ͋ Δ΋ͷʹݶͬͯݟ͖ͯ·͢
10. ͍·͞Β͚ͩͲ
 TUBHF9ͱ͸ ࠓޙͷ+4ʹೖΔ ͔΋͠Εͳ͍ ػೳͷάϨʔυ
 TUBHF͸ͷஈ֊  4UBHF
    ΞΠσΞ
     4UBHF
    ఏҊ
     4UBHF
    ࢓༷ॻυϥϑτ࡞੒ࡁ
     4UBHF
    ΄΅׬੒
    '#ٻΊͯΔ
     4UBHF
    ܾ·Γཌ೥ͷ&499ೖ
11. ༨ஊ΋͍͍ͱ͜Ͱ͕͢ɺ DTTECͷݴ͍ճ͕͠޷͖  4UBHF
    5IJT
    JT
    B
    DSB[Z
    JEFB
     4UBHF
    5IJT
    JEFB
    NJHIU
    OPU
    CF
    DSB[Z
     4UBHF
    5IJT
    JEFB
    JT
    OPU
    DSB[Z
     4UBHF
    5IJT
    JEFB
    JT
    CFDPNJOH
    QBSU
    PG
    UIF
    XFC
     4UBHF
    5IJT
    JEFB
    JT
    QBSU
    PG
    UIF
    XFC
12. v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 v.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 Lv.3 <<
    TUBHF
    >>
13. ͢Ͱʹ݁ߏݟΔͳʔͬͯ ͷ΋νϥϗϥ  !CBCFMQMVHJOTZOUBYEZOBNJD JNQPSU
     !CBCFMQMVHJOTZOUBYJNQPSUNFUB
     !CBCFMQMVHJOQSPQPTBMDMBTT QSPQFSUJFT
     !CBCFMQMVHJOQSPQPTBMKTPO TUSJOHT
14. !CBCFMQMVHJOTZOUBYEZOBNJDJNQPSU
    *NQPSU
    999
    GSPN
    ʜ
    ͱ͕ͪͬͯɺ
 ֘౰ίʔυͷҐஔ·Ͱ౸ୡͨ͠ΒίʔυΛಡΈࠐΉ async function initializeDevServer(expressApp: Express) { const { default: webpack } = await import('webpack'); const { default: webpackHotMiddleware } = await import('webpack-hot-middleware'); const { default: webpackDevMiddleware } = await import('webpack-dev-middleware'); const { default: webpackClientConfig } = await import('../../tools/webpack/client/ development'); const compiler = webpack(webpackClientConfig as any); expressApp.use(webpackHotMiddleware(compiler)); expressApp.use( webpackDevMiddleware(compiler, { noInfo: true, publicPath: webpackClientConfig.output.publicPath, }), ); } ˠEFW͚࣌ͩ͜ͷؔ਺ΛಡΉΑ͏ʹͯ͠ɺແବʹ XFCQBDLࠐΈͷCVOEMF࡞Βͳ͍Α͏ʹͯ͠·͢
15. !CBCFMQMVHJOTZOUBYJNQPSUNFUB ݴޠ࢓༷ʹೖΒͳ͍ϗετґଘͷϝλ৘ใΛϞ δϡʔϧ಺෦ʹ౉͢໾ׂΛ͢ΔಛघͳϓϩύςΟ
 IUUQTUFQQFJTIBUFOBCMPHDPNFOUSZFTNPEVMFTJOOPEFKT import.meta.url // これでこのモジュールのURLが動的にとれる ˠ/PEFͷ@@EJSOBNFΈ͍ͨͩͳ͊ͱࢥͬͨΒͦ ͏ॻ͍ͯ͋ͬͨʜ
16. !CBCFMQMVHJOQSPQPTBMDMBTT QSPQFSUJFT
    DMBTTͷϝϯόม਺Λఆٛଈ୅ೖ class User { name = 'Kyousuke Abe' gender = 'man'; birthday = new Date(1982, 9 - 1, 24); getAge = () => Math.floor((new Date() - new Date(1982, 9 - 1, 24)) / 1000 / 60 / 60 / 24 / 365); } class User { constructor() { this.name = 'Kyousuke Abe' this.gender = 'man'; this.birthday = new Date(1982, 9 - 1, 24); this.getAge = this.getAge.bind(this); } getAge() { return Math.floor((new Date() - new Date(1982, 9 - 1, 24)) / 1000 / 60 / 60 / 24 / 365); } }
17. !CBCFMQMVHJOQSPQPTBMKTPOTUSJOHT AaVaVAͱ͍͏ϒϥ΢βࡴ͠ͷ
 ΍͹͍஋ΛΤεέʔ ϓ // before const ex = "before after"; // after const ex = "before\u2028after"; ˠೖΕͱ͍ͯࠔΔ͜ͱ͸ͳͦ͞͏͚ͩͲɺ͜ͷखͷ ͸֎෦͔Β౉͞ΕΔ஋ΛνΣοΫ͢Μͷ͕େࣄͰ͢ ΑͶ
18. v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 v.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 Lv.2 <<
    TUBHF
    >>
19. ༗໊ॴ͸EFDPSBUPS
 ͦΕҎ֎ʹ΋͍Ζ͍Ζ  !CBCFMQMVHJOQSPQPTBMEFDPSBUPST
     !CBCFMQMVHJOQSPQPTBMGVODUJPOTFOU
     !CBCFMQMVHJOQSPQPTBMFYQPSU OBNFTQBDFGSPN
     !CBCFMQMVHJOQSPQPTBMOVNFSJD TFQBSBUPS
     !CBCFMQMVHJOQSPQPTBMUISPX FYQSFTTJPOT
20. !CBCFMQMVHJOQSPQPTBMEFDPSBUPST Ϋϥε͕ΒΈͷ͋Ε͜ΕʹҰωλ࢓ࠐΉ
 ର৅͸Ϋϥεͦͷ΋ͷɺϝιουͦͷଞ
 "OHVMBS࢖ͬͯΔਓ͸ඞਢ ͋Μ·ৄ͘͠ͳͯ͘ʜ @annotation class MyClass { } function annotation(target) { target.annotated = true; } ˠ޷͖ͳΜ͚ͩͲɺQSFUUJFS΍MJOUFSͱͷ૬ੑ͕೉ ͍͠ʜɻ
21. !CBCFMQMVHJOQSPQPTBMGVODUJPOTFOU
    δΣωϨʔλͷதͰ
 ௚ۙʹૹΒΕͨ஋ΛಘΒΕΔωλ function* generator() { console.log("Sent", function.sent); console.log("Yield", yield); } const iterator = generator(); iterator.next(1); // Logs "Sent 1" iterator.next(2); // Logs "Yield 2" ˠ࿩ඈͿΜͰ͕͢δΣωϨʔλͬͯॻ͍ͯ·͢ʁ
 SFEVYTBHBҎ֎Ͱ࢖ͬͯΔͷ஌Βͳ͍ʜɻ
22. !CBCFMQMVHJOQSPQPTBMFYQPSU OBNFTQBDFGSPN JNQPSUͨ͠ωλΛ໊લ͚ͭͯ·Δ͝ͱFYQPSU export * as ns from 'mod'; import { ns } from './ns'; ˠࡶͳίϝϯτͰ͕͢ɺ
 ͜Ε͘Β͍ͳΒ͍͍Μ͡Όͳ͍ʁ
23. !CBCFMQMVHJOQSPQPTBMOVNFSJD TFQBSBUPS 1ZUIPOͱ͔ʹ͋Δɺ
 ਺஋Λ@Ͱݟ΍͘͢͢Δ΍ͭ 1_000_000_000_000 0b1010_0001_1000_0101 0xa0_b0_c0 ˠຊ೔ͷʮ͋ͬͨΒخ͍͚͠Ͳ
 ͳͯ͘΋ͦΜͳʹࠔΒͳ͍ʯେ৆ީิͰ͸ʁ
24. !CBCFMQMVHJOQSPQPTBMUISPX FYQSFTTJPOT ྫ֎ΛࣜͷதͰ౤͛ΕΔ function save(filename = throw new TypeError("Argument required")) { } function getEncoder(encoding) { const encoder = encoding === "utf8" ? new UTF8Encoder() : encoding === "utf16le" ? new UTF16Encoder(false) : encoding === "utf16be" ? new UTF16Encoder(true) : throw new Error("Unsupported encoding"); } ˠ͋Μ·௚ײత͡Όͳ͍ؾ͕͢Δ
25. v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 v.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 Lv.1 LV.1 <<
    TUBHF
    >>
26. ͕͢͞ʹ
    ઑͬͨͷ͕ଟ͍  !CBCFMQMVHJOQSPQPTBMFYQPSUEFGBVMUGSPN
     !CBCFMQMVHJOQSPQPTBMMPHJDBMBTTJHONFOU PQFSBUPST
     !CBCFMQMVHJOQSPQPTBMPQUJPOBMDIBJOJOH
     !CBCFMQMVHJOQSPQPTBMQJQFMJOFPQFSBUPS
     !CBCFMQMVHJOQSPQPTBMOVMMJTIDPBMFTDJOH PQFSBUPS
     !CBCFMQMVHJOQSPQPTBMEPFYQSFTTJPOT
27. !CBCFMQMVHJOQSPQPTBMFYQPSU EFGBVMUGSPN EFGBVMU
    FYQPSU͞Εͨ΍ͭΛ
 ໊લ͚ͭͯ଎߈FYQPSU w w w w w export someIdentifier from "someModule"; export someIdentifier, { namedIdentifier } from "someModule"; ˠͦ΋ͦ΋EFGBVMU
    FYQPSUࣗମ࠷ۙ͸Ξϯνύλʔϯʁ ͨ·ʹͦ͏͍͏هࣄݟ·͢ΑͶ
    ๻΋΍Ί·ͨ͠
28. !CBCFMQMVHJOQSPQPTBMMPHJDBM BTTJHONFOUPQFSBUPST Ͳ͔ͬͰݟͨ୅ೖʹศརͳԋࢉࢠ
 ๻͸φϯ೥લ1FSMͰݟ͕֮ͨ͑ʜ
 ࠨล͕cc
    
    ͩͬͨΒӈลΛ୅ೖ a ||= b; // a || a = b a &&= b; // a && a = b a ??= b; // a ?? a = b ˠ࠶୅ೖ༻ͷԋࢉࢠ͕͸ͨͯ͠GMVYޙͷ+4γʔϯ ʹඞཁ͔ͳ͊ʁ
29. !CBCFMQMVHJOQSPQPTBMPQUJPOBM DIBJOJOH /VMM VOEFGJOFE νΣοΫ͕֨ஈʹָʹͳΔΞϨ
 TXJGU
    LPUMJO΍Δͱྑ͕͞Θ͔Γ·͢ΑͶʜ const obj = { foo: { bar: { baz: 42, }, }, }; const baz = obj?.foo?.bar?.baz; // 42 const safe = obj?.qux?.baz; // undefined const err = obj.qux.baz; // Error!!! ˠ͸΍͍ͱ͜͸͍Μͳ͍͔ͳʜɻ
30. !CBCFMQMVHJOQSPQPTBMQJQFMJOF PQFSBUPS 'ͱ͔&MJYJSͱ͔ʹ͋ΔΞϨ
    γΣϧͬΆ͍ͱ΋ function add(a, b) { return a + b; } function pow(a, b) { return a ** b; } pow(add(1, 2), 3); // 27 1 |> add(2) |> pow(3) // 27 ˠ͖ͨͬʂ͜Ε΋ͥͻͥͻདྷͯ΄͍͠ʜ
 ͚Ͳɺʮྑ͍ίʔυʯͷఆ͕ٛมΘΓ͗͢Δ͔Β
 ৻ॏʹͳΔΑͶʜɻ
31. !CBCFMQMVHJOQSPQPTBMOVMMJTI DPBMFTDJOHPQFSBUPS ͜Ε΋Αͦͷݴޠʹ͋Δ΍ͭ
 OVMM
    PS
    VOEFGJOFEͩͬͨΒ͜ͷ஋Ͷɺͬͯԋࢉࢠ
 ๻͸$Ͱॻ͍ͯ·ͨ͠ const foo = object.foo ?? 'default'; const foo = object.foo !== null && object.foo !== undefined ? object.foo : 'default'; ˠ"1*͍ͨͨͨͱ͖ͷ໭Γ஋Λύʔε͢Δͱ͖ͱ ͔ʹ࢖͑ͦ͏ͳΜͰೖͬͯ΄͍͠ʜ
32. !CBCFMQMVHJOQSPQPTBMEP FYQSFTTJPOT )BTLFMMͰݟͨ͜ͱ͋Δ΍ͭ
 EP
    ͰϒϩοΫείʔ ϓ࡞Δͱ࠷ޙͷ஋͕໭Γ஋ʹ let a = do { if(x > 10) { 'big'; } else { 'small'; } }; // is equivalent to: let a = x > 10 ? 'big' : 'small'; ˠࠓߋ҉໧తͳφχΨγ૿΍͢ͷͲ͏͔ͳʔͱ ࢥ͏
33. Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero Lv.zero <<
    TUBHF
    >>
34. ೥݄ݱࡏ
 CBCFMʹऔΓࠐ·ΕͯΔͷ͸ͭʂ  !CBCFMQMVHJOQSPQPTBMGVODUJPO CJOE
35. !CBCFMQMVHJOQSPQPTBMGVODUJPOCJOE ஌ͬͯΔਓ͸ଟ͍͚ͲʜͳΞϨ
    Ԇʑͷ·· import { map, takeWhile, forEach } from "iterlib"; getPlayers() ::map(x => x.character()) ::takeWhile(x => x.strength > 100) ::forEach(x => console.log(x)); ˠͥΜͥΜਐΜͰͳ͍ཧ༝͸͜ͷล Ͳ͏ͳΔ CJOE
    PQFSBUPS
    QSPQPTBM ʹৄ͍͠
36. ͦͷଞؾʹͳΔωλ
37. .BUI
    &YUFOTJPOT
    4UBHF
     ͓ͳ͡Έ.BUI
    ʹ৭ʑศརͳͷ௥Ճ  .BUISBEJBOT
    .BUIEFHSFFT
     .BUIDMBNQ
     .BUITDBMF
38. (FUUJOH
    MBTU
    FMFNFOU
    PG
    "SSBZ
    4UBHF
     "SSBZͷ຤ඌͷཁૉΠϯσοΫεΛ
 ҾͬுΔ  "SSBZQSPUPUZQFMBTU*UFN
     "SSBZQSPUPUZQFMBTU*OEFY
39. 1BUUFSO
    .BUDIJOH
    4UBHF
     &MJYJSͱ͔ʹ͋Δ΍ͭ
 ৚݅෼ذ৽ύλʔϯͱ͍͏͔
 TXJUDIͷѥछͬΆ͍ͱ͍͏͔ const res = await fetch(jsonService) case (res) { when {status: 200, headers: {'Content-Length': s}} -> { console.log(`size is ${s}`) } when {status: 404} -> { console.log('JSON not found') } when {status} if (status >= 400) -> { throw new RequestError(res) } }
40. 4MJDF
    OPUBUJPO
    4UBHF
     1ZUIPOͱ͔ͷ഑ྻൣғࢦఆͷύΫϦ
    ͋ͬͯ΋͑͑Μ͡Όͳ͍͔ͳ͋ʜ
 ͳͯ͘΋ͦΜͳ͜·Μͳ͍͚Ͳʜ const arr = ['a', 'b', 'c', 'd']; arr[1:3]; // ['b', 'c'] arr.slice(1, 3); // ['b', 'c'] const str = 'hello world'; str[6:]; // 'world' str.slice(6); // ‘world'
41. %FDJNBM
    4UBHF
     ͍ͭʹ+4Ͱ΋͋Δఔ౓৴པͰ͖Δܭࢉ͕Ͱ ͖ΔΑ͏ʹͳΔʜͷ͔ʁ
 'MPBUҎ֎ͷ਺஋ܕͱ͍͏ҙຯͰ΋ըظత 0.1 + 0.2 = 0.30000000000000004 0.1m + 0.2m = 0.3m
42. +BWB4DSJQU
    4UBOEBSE
    -JCSBSZ
    4UBHF
     ͍ͭ΋࢖͏͋Ε͜ΕΛόʔδϣϯࢦఆ͠ ͯJNQPSUͯ͠࢖͑ΔΑ͏ʹ͠Α·͍ʂ
    ͱ͍͏ωλɻࠓߋͰ͖ΔΜ͔ͳʁ import { Date } from "std:Date"; import { Date } from "std:Date+2.1.6-alpha.1"; const d = new Date(2018, 7, 1);
43. ͓·͚
44. &4ͳͷʹ
 FOWʹೖͬͯͳ͍΋ͷ
45. 3FH&YQ
    /BNFE
    $BQUVSF
    (SPVQT Ϛονཁૉʹ໊લΛ͚ͭͯࢀর͠΍͘͢
 ྫʹΑͬͯଞͷݴޠͰݟ·͢ const regex = /(?<year>[0-9]{4})-(?<month>[0-9]{1,2})-(? <date>[0-9]{1,2})/; const matcher = '2018-10-28'.match(regex); console.log(`${matcher.groups.year}年$ {matcher.groups.month}月${matcher.groups.date}日`); ˠ!CBCFM഑ԼͰ͸͋Γ·ͤ͵͕ɺϓϥάΠϯ͋ Γ·͢
46. 3FH&YQ
    MPPLCFIJOE
    BTTFSUJPOT ޙํࢀর
 ͦͷલ·Ͱ͕ϗχϟϥϥͩͬͨΒɺͱ͍͏৚݅ 'abcdef'.match(/(?<=abc)def/) // 'def' 'foodef'.match(/(?<=abc)def/) // null 'abcdef'.match(/(?<!abc)def/) // null 'foodef'.match(/(?<!abc)def/) // 'def' ˠϓϥάΠϯ͸ݟ͚ͭΒΕͳ͔ͬͨͰ͢
    ·͊ɺ ࣮૷೉ͦ͠͏Ͱ͢΋ΜͶ
47. ଞʹ΋͋Δ͚Ͳ
 ௕͘ͳΓ͗͢ΔΜͰҎ্ʂ
48. ͓͠·͍ Ͳ͏΋Ͱͨ͠
 ࣭໰͋ͬͨΒ͍ͭͰ΋Ͳ͏ͧ
    (JU)VC
    LBBWF
 5XJUUFS
    !KVOLKVODUJPOT
 8FC
    IUUQTLBBWFHJUIVCJP