SE-0246 Generic Math(s) Functions

Transcript

1. SE-0246:

   GENERIC MATH(S) FUNCTIONS
   OTEMACHI.SWIFT #3
   

   View Slide

2. SE-0246: GENERIC MATH(S) FUNCTIONS
   ࣗݾ঺հ
   ▸ S_Shimotori
   ▸ ඍੵ΋ઢܗ΋Ͱ͖ͳ͔ͬͨΑ…
   

   View Slide

3. SE-0246:

   GENERIC MATH(S) FUNCTIONS
   

   View Slide

4. View Slide

5. ਺ֶͬΆ͍ܭࢉ͕
   ͍Ζ͍ΖͰ͖Δ༧ײʂʂʂʂ
   

   View Slide

6. SE-0246: GENERIC MATH(S) FUNCTIONS
   ࠓ೔࿩͢͜ͱ
   ▸ SE-0246ͷ಺༰
   ▸ with modificationsͬͯͳʹ
   ▸ Ϟδϡʔϧ໊Ͳ͏͢Δ໰୊
   ▸ logؔ਺ͷ໊લͲ͏͢Δ໰୊
   

   View Slide

7. SE-0246ͷ಺༰
   

   View Slide

8. SE-0246: GENERIC MATH(S) FUNCTIONS
   SE-0246ͷϞνϕ
   ▸ C mathϥΠϒϥϦͷݺͼग़͕͠Πέͯͳ͍
   ▸ Darwin͔GNU C͔Ͱimportʹ෼ذ͕ൃੜ͢Δ
   ▸ protocol (Binary)FloatingPoint͕Πέͯͳ͍
   ▸ CGFloat, Double, Float, Float80 \in BinaryFloatingPoint
   ▸ ͜ͷprotocolΛ࢖ͬͯ਺஋ܭࢉΛߟ͑Δͷ͸ෆศ
   

   View Slide

9. SE-0246: GENERIC MATH(S) FUNCTIONS
   SE-0246ͰఏҊ͞Εͨ͜ͱ
   ▸ protocol ElementaryFunctionsͱprotocol RealΛ࡞Δ
   ▸ ॳ౳ؔ਺ηοτ \subset ࣮ؔ਺ηοτ
   ▸ staticؔ਺ͷ͔ͨͪͰܭࢉͰ͖ΔΑ͏ʹ͢Δprotocol
   ▸ ͜ΕͰࠓޙ΋ͬͱ֦ு͍͚ͯ͠Δͧʂ
   ▸ ෳૉ਺ͱ͔SIMDͱ͔
   ▸ IEEE 754ͷ࣮૷͓͢͢Ίؔ਺Λίϯϓ͢Δͱ͔
   

   View Slide

10. SE-0246: GENERIC MATH(S) FUNCTIONS
    ৽چൺֱ - SINؔ਺Λ࢖͏
    // 今のSwift
    
    let value: CGFloat = 0
    
    sin(value)
    
    // SE-0246
    
    // extension CGFloat: ElementaryFunction
    
    CGFloat.sin(0)
    

    View Slide

11. SE-0246: GENERIC MATH(S) FUNCTIONS
    ৽چൺֱ - SIGMOIDؔ਺Λఆٛ͢Δ
    // エラー。全浮動小数点数型を一括で扱えない
    
    func sigmoid(_ x: T) -> T {
    
    return 1/(1 + exp(-x))
    
    }
    
    // SE-0246ならElementaryFunctionsと一言書けばよくなる
    
    func sigmoid(_ x: T) -> T {
    
    return 1/(1 + T.exp(-x))
    
    }
    σ(x) =
    1
    1 + e−x
    ※γάϞΠυؔ਺
    

    View Slide

12. View Slide

13. View Slide

14. WITH MODIFICATION

    ͬͯͳʹ
    

    View Slide

15. SE-0246: GENERIC MATH(S) FUNCTIONS
    ACCEPTED **WITH MODIFICATIONS**
    ▸ Կ͔ٞ࿦Λͨ͠ܗ੻͕͋Δʂ
    

    View Slide

16. SE-0246: GENERIC MATH(S) FUNCTIONS
    ACCEPT͞ΕΔ·Ͱʹมߋ͞Εͨ͜ͱ
    ▸ Ұ෦ͷؔ਺͕ॳ౳ؔ਺͔Β࣮ؔ਺ߦ͖ʹ͞Εͨ
    ▸ atan2͸ඇ࣮਺ΛҾ਺ʹऔΒͳ͍
    ▸ erf, erfc, gamma, logGamma͸Ұ෦؀ڥͰ࢖͑ͳ͍͠ɺਖ਼֬ʹ͸

    ॳ౳ؔ਺͡Όͳ͍
    ▸ ࣮ؔ਺ʹ௥Ճ: hypot
    ▸ ໊લۭؒͷมߋ
    ▸ ؔ਺Λ“Math”Լʹ·ͱΊΑ͏ͱࢥ͚ͬͯͨͲ΍Ίͨ
    

    View Slide

17. Ϟδϡʔϧ
    Ͳ͏͢Δ໰୊
    

    View Slide

18. SE-0246: GENERIC MATH(S) FUNCTIONS
    ϞδϡʔϧͲ͏͢Δ໰୊
    ▸ MathϞδϡʔϧͰimport໰୊Λղܾ͢Δͭ΋Γ…ͩͬͨ
    ▸ αʔυύʔςΟϥΠϒϥϦͰ͢ͰʹMathͷ໊Λ࢖͍ͬͯΔ
    ▸ SwiftϞδϡʔϧʹ͢ͰʹmathͬΆ͍ؔ਺͕͋Δ
    ↓
    ͱΓ͋͑ͣࠓճ͸Swiftʹ௚઀ಥͬࠐΉ͚ͩʹ͠Α͏ͥʂ
    

    View Slide

19. LOGؔ਺ͷ໊લ

    Ͳ͏͢Δ໰୊
    

    View Slide

20. SE-0246: GENERIC MATH(S) FUNCTIONS
    ֤ݴޠͷର਺ؔ਺ͷ໊લ
    ࣗવର਺ ৗ༻ର਺ ΧελϜ
    Swift log log10 N/A
    log log10 N/A
    java.lang.Math log log10 N/A
    kotlin.math ln log10 log
    

    View Slide

21. SE-0246: GENERIC MATH(S) FUNCTIONS
    ͰɺͲ͏ͯ͠SWIFT͸LNͰ͸ͳ͘LOGʹͨ͠ͷ
    ▸ C++͕ͦ͏͔ͩΒ
    ▸ lnͩͱ໊લ͕୹͗͢Δ͔Β
    ▸ inͱฆΒΘ͍͔͠Β
    { x in ln(x) }
    
    { x in log(x) }
    

    View Slide

22. ·ͱΊ
    

    View Slide

23. SE-0246: GENERIC MATH(S) FUNCTIONS
    SE-0246͸͜Μͳײ͡ʂ
    ▸ ͍Ζ͍Ζͳܭࢉ͕Ͱ͖ΔΑ͏ʹͳΔΑ
    ▸ ࠓޙ͞ΒʹͰ͖Δ͜ͱ͕૿͑ͦ͏ͩΑ
    ▸ ࣮ͬͦ͘͞૷͚ͨ͠Ͳޓ׵ੑςετʁͰࣦഊ͔ͨ͠Βෆे෼
    

    View Slide

24. SE-0246: GENERIC MATH(S) FUNCTIONS
    ࢀߟจݙͱ͔ͦ͏͍͏ͷ
    ▸ swift-evolution/0246-mathable.md at master · apple/swift-evolution
    ▸ Math functions for Swift by stephentyrone · Pull Request #23140 · apple/swift
    ▸ Revert SE-0246 by stephentyrone · Pull Request #23800 · apple/swift
    ▸ SE-0246: Generic Math(s) Functions - Proposal Reviews - Swift Forums
    ▸ [Accepted with Modifications] SE-0246: Generic Math Functions -
    Announcements - Swift Forums
    ▸ Generic “math functions” - Pitches - Swift Forums
    ▸ apple/swift-source-compat-suite: The infrastructure and project index
    comprising the Swift source compatibility suite.
    

    View Slide

25. SE-0246: GENERIC MATH(S) FUNCTIONS
    ࢀߟจݙͱ͔ͦ͏͍͏ͷ
    ▸ 754-2008 - IEEE Standard for Floating-Point Arithmetic - IEEE Standard
    ▸ (math.h) - C++ Reference
    ▸ Math (Java SE 12 & JDK 12 )
    ▸ kotlin.math - Kotlin Programming Language
    

    View Slide