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SE-0246:
GENERIC MATH(S) FUNCTIONS
OTEMACHI.SWIFT #3
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SE-0246: GENERIC MATH(S) FUNCTIONS
ࣗݾհ
▸ S_Shimotori
▸ ඍੵઢܗͰ͖ͳ͔ͬͨΑ…
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SE-0246:
GENERIC MATH(S) FUNCTIONS
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ֶͬΆ͍ܭࢉ͕
͍Ζ͍ΖͰ͖Δ༧ײʂʂʂʂ
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SE-0246: GENERIC MATH(S) FUNCTIONS
ࠓ͢͜ͱ
▸ SE-0246ͷ༰
▸ with modificationsͬͯͳʹ
▸ Ϟδϡʔϧ໊Ͳ͏͢Δ
▸ logؔͷ໊લͲ͏͢Δ
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SE-0246ͷ༰
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SE-0246: GENERIC MATH(S) FUNCTIONS
SE-0246ͷϞνϕ
▸ C mathϥΠϒϥϦͷݺͼग़͕͠Πέͯͳ͍
▸ Darwin͔GNU C͔Ͱimportʹذ͕ൃੜ͢Δ
▸ protocol (Binary)FloatingPoint͕Πέͯͳ͍
▸ CGFloat, Double, Float, Float80 \in BinaryFloatingPoint
▸ ͜ͷprotocolΛͬͯܭࢉΛߟ͑Δͷෆศ
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SE-0246: GENERIC MATH(S) FUNCTIONS
SE-0246ͰఏҊ͞Εͨ͜ͱ
▸ protocol ElementaryFunctionsͱprotocol RealΛ࡞Δ
▸ ॳؔηοτ \subset ࣮ؔηοτ
▸ staticؔͷ͔ͨͪͰܭࢉͰ͖ΔΑ͏ʹ͢Δprotocol
▸ ͜ΕͰࠓޙͬͱ֦ு͍͚ͯ͠Δͧʂ
▸ ෳૉͱ͔SIMDͱ͔
▸ IEEE 754ͷ࣮͓͢͢ΊؔΛίϯϓ͢Δͱ͔
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SE-0246: GENERIC MATH(S) FUNCTIONS
৽چൺֱ - SINؔΛ͏
// 今のSwift
let value: CGFloat = 0
sin(value)
// SE-0246
// extension CGFloat: ElementaryFunction
CGFloat.sin(0)
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SE-0246: GENERIC MATH(S) FUNCTIONS
৽چൺֱ - SIGMOIDؔΛఆٛ͢Δ
// 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
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WITH MODIFICATION
ͬͯͳʹ
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SE-0246: GENERIC MATH(S) FUNCTIONS
ACCEPTED **WITH MODIFICATIONS**
▸ Կ͔ٞΛͨ͠ܗ͕͋Δʂ
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SE-0246: GENERIC MATH(S) FUNCTIONS
ACCEPT͞ΕΔ·Ͱʹมߋ͞Εͨ͜ͱ
▸ Ұ෦ͷ͕ؔॳ͔ؔΒ࣮ؔߦ͖ʹ͞Εͨ
▸ atan2ඇ࣮ΛҾʹऔΒͳ͍
▸ erf, erfc, gamma, logGammaҰ෦ڥͰ͑ͳ͍͠ɺਖ਼֬ʹ
ॳؔ͡Όͳ͍
▸ ࣮ؔʹՃ: hypot
▸ ໊લۭؒͷมߋ
▸ ؔΛ“Math”Լʹ·ͱΊΑ͏ͱࢥ͚ͬͯͨͲΊͨ
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Ϟδϡʔϧ
Ͳ͏͢Δ
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SE-0246: GENERIC MATH(S) FUNCTIONS
ϞδϡʔϧͲ͏͢Δ
▸ MathϞδϡʔϧͰimportΛղܾ͢ΔͭΓ…ͩͬͨ
▸ αʔυύʔςΟϥΠϒϥϦͰ͢ͰʹMathͷ໊Λ͍ͬͯΔ
▸ SwiftϞδϡʔϧʹ͢ͰʹmathͬΆ͍͕ؔ͋Δ
↓
ͱΓ͋͑ͣࠓճSwiftʹಥͬࠐΉ͚ͩʹ͠Α͏ͥʂ
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LOGؔͷ໊લ
Ͳ͏͢Δ
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SE-0246: GENERIC MATH(S) FUNCTIONS
֤ݴޠͷରؔͷ໊લ
ࣗવର ৗ༻ର ΧελϜ
Swift log log10 N/A
log log10 N/A
java.lang.Math log log10 N/A
kotlin.math ln log10 log
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SE-0246: GENERIC MATH(S) FUNCTIONS
ͰɺͲ͏ͯ͠SWIFTLNͰͳ͘LOGʹͨ͠ͷ
▸ C++͕ͦ͏͔ͩΒ
▸ lnͩͱ໊લ͕͗͢Δ͔Β
▸ inͱฆΒΘ͍͔͠Β
{ x in ln(x) }
{ x in log(x) }
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·ͱΊ
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SE-0246: GENERIC MATH(S) FUNCTIONS
SE-0246͜Μͳײ͡ʂ
▸ ͍Ζ͍Ζͳܭࢉ͕Ͱ͖ΔΑ͏ʹͳΔΑ
▸ ࠓޙ͞ΒʹͰ͖Δ͜ͱ͕૿͑ͦ͏ͩΑ
▸ ࣮͚ͬͦͨ͘͞͠ͲޓੑςετʁͰࣦഊ͔ͨ͠Βෆे
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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.
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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