| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2016 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See http://swift.org/LICENSE.txt for license information |
| // See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| // |
| |
| import CoreFoundation |
| |
| public var NSDecimalMaxSize: Int32 { return 8 } |
| // Give a precision of at least 38 decimal digits, 128 binary positions. |
| |
| public var NSDecimalNoScale: Int32 { return Int32(Int16.max) } |
| |
| public struct Decimal { |
| fileprivate static let maxSize: UInt32 = UInt32(NSDecimalMaxSize) |
| fileprivate var __exponent: Int8 |
| fileprivate var __lengthAndFlags: UInt8 |
| fileprivate var __reserved: UInt16 |
| public var _exponent: Int32 { |
| get { |
| return Int32(__exponent) |
| } |
| set { |
| __exponent = Int8(truncatingIfNeeded: newValue) |
| } |
| } |
| // length == 0 && isNegative -> NaN |
| public var _length: UInt32 { |
| get { |
| return UInt32((__lengthAndFlags & 0b0000_1111)) |
| } |
| set { |
| guard newValue <= maxMantissaLength else { |
| fatalError("Attempt to set a length greater than capacity \(newValue) > \(maxMantissaLength)") |
| } |
| __lengthAndFlags = |
| (__lengthAndFlags & 0b1111_0000) | |
| UInt8(newValue & 0b0000_1111) |
| } |
| } |
| public var _isNegative: UInt32 { |
| get { |
| return UInt32(((__lengthAndFlags) & 0b0001_0000) >> 4) |
| } |
| set { |
| __lengthAndFlags = |
| (__lengthAndFlags & 0b1110_1111) | |
| (UInt8(newValue & 0b0000_0001 ) << 4) |
| } |
| } |
| public var _isCompact: UInt32 { |
| get { |
| return UInt32(((__lengthAndFlags) & 0b0010_0000) >> 5) |
| } |
| set { |
| __lengthAndFlags = |
| (__lengthAndFlags & 0b1101_1111) | |
| (UInt8(newValue & 0b0000_00001 ) << 5) |
| } |
| } |
| public var _reserved: UInt32 { |
| get { |
| return UInt32(UInt32(__lengthAndFlags & 0b1100_0000) << 10 | UInt32(__reserved)) |
| } |
| set { |
| __lengthAndFlags = |
| (__lengthAndFlags & 0b0011_1111) | |
| UInt8(UInt32(newValue & (0b11 << 16)) >> 10) |
| __reserved = UInt16(newValue & 0b1111_1111_1111_1111) |
| } |
| } |
| public var _mantissa: (UInt16, UInt16, UInt16, UInt16, UInt16, UInt16, UInt16, UInt16) |
| public init() { |
| self._mantissa = (0,0,0,0,0,0,0,0) |
| self.__exponent = 0 |
| self.__lengthAndFlags = 0 |
| self.__reserved = 0 |
| } |
| |
| fileprivate init(length: UInt32, mantissa: (UInt16, UInt16, UInt16, UInt16, UInt16, UInt16, UInt16, UInt16)) { |
| self._mantissa = mantissa |
| self.__exponent = 0 |
| self.__lengthAndFlags = 0 |
| self.__reserved = 0 |
| self._length = length |
| } |
| |
| public init(_exponent: Int32, _length: UInt32, _isNegative: UInt32, _isCompact: UInt32, _reserved: UInt32, _mantissa: (UInt16, UInt16, UInt16, UInt16, UInt16, UInt16, UInt16, UInt16)){ |
| self._mantissa = _mantissa |
| self.__exponent = Int8(truncatingIfNeeded: _exponent) |
| self.__lengthAndFlags = UInt8(_length & 0b1111) |
| self.__reserved = 0 |
| self._isNegative = _isNegative |
| self._isCompact = _isCompact |
| self._reserved = _reserved |
| } |
| } |
| |
| extension Decimal { |
| public static let leastFiniteMagnitude = Decimal( |
| _exponent: 127, |
| _length: 8, |
| _isNegative: 1, |
| _isCompact: 1, |
| _reserved: 0, |
| _mantissa: (0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff) |
| ) |
| public static let greatestFiniteMagnitude = Decimal( |
| _exponent: 127, |
| _length: 8, |
| _isNegative: 0, |
| _isCompact: 1, |
| _reserved: 0, |
| _mantissa: (0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff) |
| ) |
| public static let leastNormalMagnitude = Decimal( |
| _exponent: -127, |
| _length: 1, |
| _isNegative: 0, |
| _isCompact: 1, |
| _reserved: 0, |
| _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000) |
| ) |
| public static let leastNonzeroMagnitude = Decimal( |
| _exponent: -127, |
| _length: 1, |
| _isNegative: 0, |
| _isCompact: 1, |
| _reserved: 0, |
| _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000) |
| ) |
| public static let pi = Decimal( |
| _exponent: -38, |
| _length: 8, |
| _isNegative: 0, |
| _isCompact: 1, |
| _reserved: 0, |
| _mantissa: (0x6623, 0x7d57, 0x16e7, 0xad0d, 0xaf52, 0x4641, 0xdfa7, 0xec58) |
| ) |
| public var exponent: Int { |
| get { |
| return Int(self.__exponent) |
| } |
| } |
| public var significand: Decimal { |
| get { |
| return Decimal(_exponent: 0, _length: _length, _isNegative: _isNegative, _isCompact: _isCompact, _reserved: 0, _mantissa: _mantissa) |
| } |
| } |
| public init(sign: FloatingPointSign, exponent: Int, significand: Decimal) { |
| self.init(_exponent: Int32(exponent) + significand._exponent, _length: significand._length, _isNegative: sign == .plus ? 0 : 1, _isCompact: significand._isCompact, _reserved: 0, _mantissa: significand._mantissa) |
| } |
| public init(signOf: Decimal, magnitudeOf magnitude: Decimal) { |
| self.init(_exponent: magnitude._exponent, _length: magnitude._length, _isNegative: signOf._isNegative, _isCompact: magnitude._isCompact, _reserved: 0, _mantissa: magnitude._mantissa) |
| } |
| public var sign: FloatingPointSign { |
| return _isNegative == 0 ? FloatingPointSign.plus : FloatingPointSign.minus |
| } |
| public static var radix: Int { |
| return 10 |
| } |
| public var ulp: Decimal { |
| if !self.isFinite { return Decimal.nan } |
| return Decimal(_exponent: _exponent, _length: 8, _isNegative: 0, _isCompact: 1, _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000)) |
| } |
| public func isEqual(to other: Decimal) -> Bool { |
| return self.compare(to: other) == .orderedSame |
| } |
| public func isLess(than other: Decimal) -> Bool { |
| return self.compare(to: other) == .orderedAscending |
| } |
| public func isLessThanOrEqualTo(_ other: Decimal) -> Bool { |
| let comparison = self.compare(to: other) |
| return comparison == .orderedAscending || comparison == .orderedSame |
| } |
| public func isTotallyOrdered(belowOrEqualTo other: Decimal) -> Bool { |
| // Notes: Decimal does not have -0 or infinities to worry about |
| if self.isNaN { |
| return false |
| } else if self < other { |
| return true |
| } else if other < self { |
| return false |
| } |
| // fall through to == behavior |
| return true |
| } |
| public var isCanonical: Bool { |
| return true |
| } |
| public var nextUp: Decimal { |
| return self + Decimal(_exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1, _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000)) |
| } |
| public var nextDown: Decimal { |
| return self - Decimal(_exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1, _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000)) |
| } |
| } |
| |
| extension Decimal : Hashable, Comparable { |
| internal var doubleValue: Double { |
| var d = 0.0 |
| if _length == 0 && _isNegative == 1 { |
| return Double.nan |
| } |
| |
| d = d * 65536 + Double(_mantissa.7) |
| d = d * 65536 + Double(_mantissa.6) |
| d = d * 65536 + Double(_mantissa.5) |
| d = d * 65536 + Double(_mantissa.4) |
| d = d * 65536 + Double(_mantissa.3) |
| d = d * 65536 + Double(_mantissa.2) |
| d = d * 65536 + Double(_mantissa.1) |
| d = d * 65536 + Double(_mantissa.0) |
| |
| if _exponent < 0 { |
| for _ in _exponent..<0 { |
| d /= 10.0 |
| } |
| } else { |
| for _ in 0..<_exponent { |
| d *= 10.0 |
| } |
| } |
| return _isNegative != 0 ? -d : d |
| } |
| public var hashValue: Int { |
| return Int(bitPattern: __CFHashDouble(doubleValue)) |
| } |
| public static func ==(lhs: Decimal, rhs: Decimal) -> Bool { |
| if lhs.isNaN { |
| return rhs.isNaN |
| } |
| if lhs.__exponent == rhs.__exponent && lhs.__lengthAndFlags == rhs.__lengthAndFlags && lhs.__reserved == rhs.__reserved { |
| if lhs._mantissa.0 == rhs._mantissa.0 && |
| lhs._mantissa.1 == rhs._mantissa.1 && |
| lhs._mantissa.2 == rhs._mantissa.2 && |
| lhs._mantissa.3 == rhs._mantissa.3 && |
| lhs._mantissa.4 == rhs._mantissa.4 && |
| lhs._mantissa.5 == rhs._mantissa.5 && |
| lhs._mantissa.6 == rhs._mantissa.6 && |
| lhs._mantissa.7 == rhs._mantissa.7 { |
| return true |
| } |
| } |
| var lhsVal = lhs |
| var rhsVal = rhs |
| return NSDecimalCompare(&lhsVal, &rhsVal) == .orderedSame |
| } |
| public static func <(lhs: Decimal, rhs: Decimal) -> Bool { |
| var lhsVal = lhs |
| var rhsVal = rhs |
| return NSDecimalCompare(&lhsVal, &rhsVal) == .orderedAscending |
| } |
| } |
| |
| extension Decimal : ExpressibleByFloatLiteral { |
| public init(floatLiteral value: Double) { |
| self.init(value) |
| } |
| } |
| |
| extension Decimal : ExpressibleByIntegerLiteral { |
| public init(integerLiteral value: Int) { |
| self.init(value) |
| } |
| } |
| |
| extension Decimal : SignedNumeric { |
| public var magnitude: Decimal { |
| return Decimal(_exponent: _exponent, _length: _length, _isNegative: 0, _isCompact: _isCompact, _reserved: 0, _mantissa: _mantissa) |
| } |
| |
| // FIXME(integers): implement properly |
| public init?<T : BinaryInteger>(exactly source: T) { |
| fatalError() |
| } |
| |
| public static func +=(_ lhs: inout Decimal, _ rhs: Decimal) { |
| var leftOp = lhs |
| var rightOp = rhs |
| _ = NSDecimalAdd(&lhs, &leftOp, &rightOp, .plain) |
| } |
| |
| public static func -=(_ lhs: inout Decimal, _ rhs: Decimal) { |
| var leftOp = lhs |
| var rightOp = rhs |
| _ = NSDecimalSubtract(&lhs, &leftOp, &rightOp, .plain) |
| } |
| |
| public static func *=(_ lhs: inout Decimal, _ rhs: Decimal) { |
| var leftOp = lhs |
| var rightOp = rhs |
| _ = NSDecimalMultiply(&lhs, &leftOp, &rightOp, .plain) |
| } |
| |
| public static func /=(_ lhs: inout Decimal, _ rhs: Decimal) { |
| var leftOp = lhs |
| var rightOp = rhs |
| _ = NSDecimalDivide(&lhs, &leftOp, &rightOp, .plain) |
| } |
| |
| public static func +(lhs: Decimal, rhs: Decimal) -> Decimal { |
| var answer = lhs |
| answer += rhs |
| return answer; |
| } |
| |
| public static func -(lhs: Decimal, rhs: Decimal) -> Decimal { |
| var answer = lhs |
| answer -= rhs |
| return answer; |
| } |
| |
| public static func /(lhs: Decimal, rhs: Decimal) -> Decimal { |
| var answer = lhs |
| answer /= rhs |
| return answer; |
| } |
| |
| public static func *(lhs: Decimal, rhs: Decimal) -> Decimal { |
| var answer = lhs |
| answer *= rhs |
| return answer; |
| } |
| |
| public mutating func negate() { |
| guard _length != 0 else { return } |
| _isNegative = _isNegative == 0 ? 1 : 0 |
| } |
| } |
| |
| extension Decimal { |
| @available(swift, obsoleted: 4, message: "Please use arithmetic operators instead") |
| @_transparent |
| public mutating func add(_ other: Decimal) { |
| self += other |
| } |
| |
| @available(swift, obsoleted: 4, message: "Please use arithmetic operators instead") |
| @_transparent |
| public mutating func subtract(_ other: Decimal) { |
| self -= other |
| } |
| |
| @available(swift, obsoleted: 4, message: "Please use arithmetic operators instead") |
| @_transparent |
| public mutating func multiply(by other: Decimal) { |
| self *= other |
| } |
| |
| @available(swift, obsoleted: 4, message: "Please use arithmetic operators instead") |
| @_transparent |
| public mutating func divide(by other: Decimal) { |
| self /= other |
| } |
| } |
| |
| extension Decimal : Strideable { |
| public func distance(to other: Decimal) -> Decimal { |
| return self - other |
| } |
| public func advanced(by n: Decimal) -> Decimal { |
| return self + n |
| } |
| } |
| |
| extension Decimal { |
| public typealias RoundingMode = NSDecimalNumber.RoundingMode |
| public typealias CalculationError = NSDecimalNumber.CalculationError |
| public init(_ value: UInt8) { |
| self.init(UInt64(value)) |
| } |
| public init(_ value: Int8) { |
| self.init(Int64(value)) |
| } |
| public init(_ value: UInt16) { |
| self.init(UInt64(value)) |
| } |
| public init(_ value: Int16) { |
| self.init(Int64(value)) |
| } |
| public init(_ value: UInt32) { |
| self.init(UInt64(value)) |
| } |
| public init(_ value: Int32) { |
| self.init(Int64(value)) |
| } |
| public init(_ value: Double) { |
| if value.isNaN { |
| self = Decimal.nan |
| } else if value == 0.0 { |
| self = Decimal() |
| } else { |
| self = Decimal() |
| let negative = value < 0 |
| var val = negative ? -1 * value : value |
| var exponent = 0 |
| while val < Double(UInt64.max - 1) { |
| val *= 10.0 |
| exponent -= 1 |
| } |
| while Double(UInt64.max - 1) < val { |
| val /= 10.0 |
| exponent += 1 |
| } |
| var mantissa = UInt64(val) |
| |
| var i = Int32(0) |
| // this is a bit ugly but it is the closest approximation of the C initializer that can be expressed here. |
| while mantissa != 0 && i < NSDecimalMaxSize { |
| switch i { |
| case 0: |
| _mantissa.0 = UInt16(truncatingIfNeeded:mantissa) |
| case 1: |
| _mantissa.1 = UInt16(truncatingIfNeeded:mantissa) |
| case 2: |
| _mantissa.2 = UInt16(truncatingIfNeeded:mantissa) |
| case 3: |
| _mantissa.3 = UInt16(truncatingIfNeeded:mantissa) |
| case 4: |
| _mantissa.4 = UInt16(truncatingIfNeeded:mantissa) |
| case 5: |
| _mantissa.5 = UInt16(truncatingIfNeeded:mantissa) |
| case 6: |
| _mantissa.6 = UInt16(truncatingIfNeeded:mantissa) |
| case 7: |
| _mantissa.7 = UInt16(truncatingIfNeeded:mantissa) |
| default: |
| fatalError("initialization overflow") |
| } |
| mantissa = mantissa >> 16 |
| i += 1 |
| } |
| _length = UInt32(i) |
| _isNegative = negative ? 1 : 0 |
| _isCompact = 0 |
| _exponent = Int32(exponent) |
| self.compact() |
| } |
| } |
| public init(_ value: UInt64) { |
| self.init(Double(value)) |
| } |
| public init(_ value: Int64) { |
| self.init(Double(value)) |
| } |
| public init(_ value: UInt) { |
| self.init(UInt64(value)) |
| } |
| public init(_ value: Int) { |
| self.init(Int64(value)) |
| } |
| public var isSignalingNaN: Bool { |
| return false |
| } |
| public static var nan: Decimal { |
| return quietNaN |
| } |
| public static var quietNaN: Decimal { |
| var quiet = Decimal() |
| quiet._isNegative = 1 |
| return quiet |
| } |
| public var floatingPointClass: FloatingPointClassification { |
| if _length == 0 && _isNegative == 1 { |
| return .quietNaN |
| } else if _length == 0 { |
| return .positiveZero |
| } |
| if _isNegative == 1 { |
| return .negativeNormal |
| } else { |
| return .positiveNormal |
| } |
| } |
| public var isSignMinus: Bool { |
| return _isNegative != 0 |
| } |
| public var isNormal: Bool { |
| return !isZero && !isInfinite && !isNaN |
| } |
| public var isFinite: Bool { |
| return !isNaN |
| } |
| public var isZero: Bool { |
| return _length == 0 && _isNegative == 0 |
| } |
| public var isSubnormal: Bool { |
| return false |
| } |
| public var isInfinite: Bool { |
| return false |
| } |
| public var isNaN: Bool { |
| return _length == 0 && _isNegative == 1 |
| } |
| public var isSignaling: Bool { |
| return false |
| } |
| } |
| |
| extension Decimal : CustomStringConvertible { |
| public init?(string: String, locale: Locale? = nil) { |
| let scan = Scanner(string: string) |
| var theDecimal = Decimal() |
| if !scan.scanDecimal(&theDecimal) { |
| return nil |
| } |
| self = theDecimal |
| } |
| public var description: String { |
| if self.isNaN { |
| return "NaN" |
| } |
| if _length == 0 { |
| return "0" |
| } |
| var copy = self |
| let ZERO : CChar = 0x30 // ASCII '0' == 0x30 |
| let decimalChar : CChar = 0x2e // ASCII '.' == 0x2e |
| let MINUS : CChar = 0x2d // ASCII '-' == 0x2d |
| |
| let bufferSize = 200 // max value : 39+128+sign+decimalpoint |
| var buffer = Array<CChar>(repeating: 0, count: bufferSize) |
| |
| var i = bufferSize - 1 |
| while copy._exponent > 0 { |
| i -= 1 |
| buffer[i] = ZERO |
| copy._exponent -= 1 |
| } |
| |
| if copy._exponent == 0 { |
| copy._exponent = 1 |
| } |
| |
| while copy._length != 0 { |
| var remainder: UInt16 = 0 |
| if copy._exponent == 0 { |
| i -= 1 |
| buffer[i] = decimalChar |
| } |
| copy._exponent += 1 |
| (remainder,_) = divideByShort(©, 10) |
| i -= 1 |
| buffer[i] = Int8(remainder) + ZERO |
| } |
| if copy._exponent <= 0 { |
| while copy._exponent != 0 { |
| i -= 1 |
| buffer[i] = ZERO |
| copy._exponent += 1 |
| } |
| i -= 1 |
| buffer[i] = decimalChar |
| i -= 1 |
| buffer[i] = ZERO |
| } |
| if copy._isNegative != 0 { |
| i -= 1 |
| buffer[i] = MINUS |
| } |
| return String(cString: Array(buffer.suffix(from:i))) |
| } |
| } |
| |
| fileprivate func divideByShort<T:VariableLengthNumber>(_ d: inout T, _ divisor:UInt16) -> (UInt16,NSDecimalNumber.CalculationError) { |
| if divisor == 0 { |
| d._length = 0 |
| return (0,.divideByZero) |
| } |
| // note the below is not the same as from length to 0 by -1 |
| var carry: UInt32 = 0 |
| for i in (0..<d._length).reversed() { |
| let accumulator = UInt32(d[i]) + carry * (1<<16) |
| d[i] = UInt16(accumulator / UInt32(divisor)) |
| carry = accumulator % UInt32(divisor) |
| } |
| d.trimTrailingZeros() |
| return (UInt16(carry),.noError) |
| } |
| |
| fileprivate func multiplyByShort<T:VariableLengthNumber>(_ d: inout T, _ mul:UInt16) -> NSDecimalNumber.CalculationError { |
| if mul == 0 { |
| d._length = 0 |
| return .noError |
| } |
| var carry: UInt32 = 0 |
| // FIXME handle NSCalculationOverflow here? |
| for i in 0..<d._length { |
| let accumulator: UInt32 = UInt32(d[i]) * UInt32(mul) + carry |
| carry = accumulator >> 16 |
| d[i] = UInt16(truncatingIfNeeded: accumulator) |
| } |
| if carry != 0 { |
| if d._length >= Decimal.maxSize { |
| return .overflow |
| } |
| d[d._length] = UInt16(truncatingIfNeeded: carry) |
| d._length += 1 |
| } |
| return .noError |
| } |
| |
| fileprivate func addShort<T:VariableLengthNumber>(_ d: inout T, _ add:UInt16) -> NSDecimalNumber.CalculationError { |
| var carry:UInt32 = UInt32(add) |
| for i in 0..<d._length { |
| let accumulator: UInt32 = UInt32(d[i]) + carry |
| carry = accumulator >> 16 |
| d[i] = UInt16(truncatingIfNeeded: accumulator) |
| } |
| if carry != 0 { |
| if d._length >= Decimal.maxSize { |
| return .overflow |
| } |
| d[d._length] = UInt16(truncatingIfNeeded: carry) |
| d._length += 1 |
| } |
| return .noError |
| } |
| |
| public func NSDecimalIsNotANumber(_ dcm: UnsafePointer<Decimal>) -> Bool { |
| return dcm.pointee.isNaN |
| } |
| |
| /*************** Operations ***********/ |
| public func NSDecimalCopy(_ destination: UnsafeMutablePointer<Decimal>, _ source: UnsafePointer<Decimal>) { |
| destination.pointee.__lengthAndFlags = source.pointee.__lengthAndFlags |
| destination.pointee.__exponent = source.pointee.__exponent |
| destination.pointee.__reserved = source.pointee.__reserved |
| destination.pointee._mantissa = source.pointee._mantissa |
| } |
| |
| public func NSDecimalCompact(_ number: UnsafeMutablePointer<Decimal>) { |
| number.pointee.compact() |
| } |
| |
| // NSDecimalCompare:Compares leftOperand and rightOperand. |
| public func NSDecimalCompare(_ leftOperand: UnsafePointer<Decimal>, _ rightOperand: UnsafePointer<Decimal>) -> ComparisonResult { |
| let left = leftOperand.pointee |
| let right = rightOperand.pointee |
| return left.compare(to: right) |
| } |
| |
| fileprivate extension UInt16 { |
| func compareTo(_ other: UInt16) -> ComparisonResult { |
| if self < other { |
| return .orderedAscending |
| } else if self > other { |
| return .orderedDescending |
| } else { |
| return .orderedSame |
| } |
| } |
| } |
| |
| fileprivate func mantissaCompare<T:VariableLengthNumber>( |
| _ left: T, |
| _ right: T) -> ComparisonResult { |
| |
| if left._length > right._length { |
| return .orderedDescending |
| } |
| if left._length < right._length { |
| return .orderedAscending |
| } |
| let length = left._length // == right._length |
| for i in (0..<length).reversed() { |
| let comparison = left[i].compareTo(right[i]) |
| if comparison != .orderedSame { |
| return comparison |
| } |
| } |
| return .orderedSame |
| } |
| |
| fileprivate func fitMantissa(_ big: inout WideDecimal, _ exponent: inout Int32, _ roundingMode: NSDecimalNumber.RoundingMode) -> NSDecimalNumber.CalculationError { |
| |
| if big._length <= Decimal.maxSize { |
| return .noError |
| } |
| |
| var remainder: UInt16 = 0 |
| var previousRemainder: Bool = false |
| |
| // Divide by 10 as much as possible |
| while big._length > Decimal.maxSize + 1 { |
| if remainder != 0 { |
| previousRemainder = true |
| } |
| (remainder,_) = divideByShort(&big,10000) |
| exponent += 4 |
| } |
| |
| while big._length > Decimal.maxSize { |
| if remainder != 0 { |
| previousRemainder = true |
| } |
| (remainder,_) = divideByShort(&big,10) |
| exponent += 1 |
| } |
| |
| // If we are on a tie, adjust with previous remainder. |
| // .50001 is equivalent to .6 |
| if previousRemainder && (remainder == 0 || remainder == 5) { |
| remainder += 1 |
| } |
| |
| if remainder == 0 { |
| return .noError |
| } |
| |
| // Round the result |
| switch roundingMode { |
| case .down: |
| break |
| case .bankers: |
| if remainder == 5 && (big[0] & 1) == 0 { |
| break |
| } |
| fallthrough |
| case .plain: |
| if remainder < 5 { |
| break |
| } |
| fallthrough |
| case .up: |
| let originalLength = big._length |
| // big._length += 1 ?? |
| _ = addShort(&big,1) |
| if originalLength > big._length { |
| // the last digit is == 0. Remove it. |
| _ = divideByShort(&big, 10) |
| exponent += 1 |
| } |
| } |
| return .lossOfPrecision; |
| } |
| |
| fileprivate func integerMultiply<T:VariableLengthNumber>(_ big: inout T, |
| _ left: T, |
| _ right: Decimal) -> NSDecimalNumber.CalculationError { |
| if left._length == 0 || right._length == 0 { |
| big._length = 0 |
| return .noError |
| } |
| |
| if big._length == 0 || big._length > left._length + right._length { |
| big._length = min(big.maxMantissaLength,left._length + right._length) |
| } |
| |
| big.zeroMantissa() |
| |
| var carry: UInt16 = 0 |
| |
| for j in 0..<right._length { |
| var accumulator: UInt32 = 0 |
| carry = 0 |
| |
| for i in 0..<left._length { |
| if i + j < big._length { |
| let bigij = UInt32(big[i+j]) |
| accumulator = UInt32(carry) + bigij + UInt32(right[j]) * UInt32(left[i]) |
| carry = UInt16(truncatingIfNeeded:accumulator >> 16) |
| big[i+j] = UInt16(truncatingIfNeeded:accumulator) |
| } else if carry != 0 || (right[j] == 0 && left[j] == 0) { |
| return .overflow |
| } |
| } |
| |
| if carry != 0 { |
| if left._length + j < big._length { |
| big[left._length + j] = carry |
| } else { |
| return .overflow |
| } |
| } |
| } |
| |
| big.trimTrailingZeros() |
| |
| return .noError |
| } |
| |
| fileprivate func integerDivide<T:VariableLengthNumber>(_ r: inout T, |
| _ cu: T, |
| _ cv: Decimal) -> NSDecimalNumber.CalculationError { |
| // Calculate result = a / b. |
| // Result could NOT be a pointer to same space as a or b. |
| // resultLen must be >= aLen - bLen. |
| // |
| // Based on algorithm in The Art of Computer Programming, Volume 2, |
| // Seminumerical Algorithms by Donald E. Knuth, 2nd Edition. In addition |
| // you need to consult the erratas for the book available at: |
| // |
| // http://www-cs-faculty.stanford.edu/~uno/taocp.html |
| |
| var u = WideDecimal(true) |
| var v = WideDecimal(true) // divisor |
| |
| // Simple case |
| if cv.isZero { |
| return .divideByZero; |
| } |
| |
| // If u < v, the result is approximately 0... |
| if cu._length < cv._length { |
| for i in 0..<cv._length { |
| if cu[i] < cv[i] { |
| r._length = 0 |
| return .noError; |
| } |
| } |
| } |
| |
| // Fast algorithm |
| if cv._length == 1 { |
| r = cu |
| let (_,error) = divideByShort(&r, cv[0]) |
| return error |
| } |
| |
| u.copyMantissa(from: cu) |
| v.copyMantissa(from: cv) |
| |
| u._length = cu._length + 1 |
| v._length = cv._length + 1 |
| |
| // D1: Normalize |
| // Calculate d such that d*highest_digit of v >= b/2 (0x8000) |
| // |
| // I could probably use something smarter to get d to be a power of 2. |
| // In this case the multiply below became only a shift. |
| let d: UInt32 = UInt32((1 << 16) / Int(cv[cv._length - 1] + 1)) |
| |
| // This is to make the whole algorithm work and u*d/v*d == u/v |
| _ = multiplyByShort(&u, UInt16(d)) |
| _ = multiplyByShort(&v, UInt16(d)) |
| |
| u.trimTrailingZeros() |
| v.trimTrailingZeros() |
| |
| // Set a zero at the leftmost u position if the multiplication |
| // does not have a carry. |
| if u._length == cu._length { |
| u[u._length] = 0 |
| u._length += 1 |
| } |
| |
| v[v._length] = 0; // Set a zero at the leftmost v position. |
| // the algorithm will use it during the |
| // multiplication/subtraction phase. |
| |
| // Determine the size of the quotient. |
| // It's an approximate value. |
| let ql:UInt16 = UInt16(u._length - v._length) |
| |
| // Some useful constants for the loop |
| // It's used to determine the quotient digit as fast as possible |
| // The test vl > 1 is probably useless, since optimizations |
| // up there are taking over this case. I'll keep it, just in case. |
| let v1:UInt16 = v[v._length-1] |
| let v2:UInt16 = v._length > 1 ? v[v._length-2] : 0 |
| |
| // D2: initialize j |
| // On each pass, build a single value for the quotient. |
| for j in 0..<ql { |
| |
| // D3: calculate q^ |
| // This formula and test for q gives at most q+1; See Knuth for proof. |
| |
| let ul = u._length |
| let tmp:UInt32 = UInt32(u[ul - UInt32(j) - UInt32(1)]) << 16 + UInt32(u[ul - UInt32(j) - UInt32(2)]) |
| var q:UInt32 = tmp / UInt32(v1) // Quotient digit. could be a short. |
| var rtmp:UInt32 = tmp % UInt32(v1) |
| |
| // This test catches all cases where q is really q+2 and |
| // most where it is q+1 |
| if q == (1 << 16) || UInt32(v2) * q > (rtmp<<16) + UInt32(u[ul - UInt32(j) - UInt32(3)]) { |
| q -= 1 |
| rtmp += UInt32(v1) |
| |
| if (rtmp < (1 << 16)) && ( (q == (1 << 16) ) || ( UInt32(v2) * q > (rtmp<<16) + UInt32(u[ul - UInt32(j) - UInt32(3)])) ) { |
| q -= 1 |
| rtmp += UInt32(v1) |
| } |
| } |
| |
| // D4: multiply and subtract. |
| |
| var mk:UInt32 = 0 // multiply carry |
| var sk:UInt32 = 1 // subtraction carry |
| var acc:UInt32 |
| |
| // We perform a multiplication and a subtraction |
| // during the same pass... |
| for i in 0...v._length { |
| let ul = u._length |
| let vl = v._length |
| acc = q * UInt32(v[i]) + mk // multiply |
| mk = acc >> 16 // multiplication carry |
| acc = acc & 0xffff; |
| acc = 0xffff + UInt32(u[ul - vl + i - UInt32(j) - UInt32(1)]) - acc + sk; // subtract |
| sk = acc >> 16; |
| u[ul - vl + i - UInt32(j) - UInt32(1)] = UInt16(truncatingIfNeeded:acc) |
| } |
| |
| // D5: test remainder |
| // This test catches cases where q is still q + 1 |
| if sk == 0 { |
| // D6: add back. |
| var k:UInt32 = 0 // Addition carry |
| |
| // subtract one from the quotient digit |
| q -= 1 |
| for i in 0...v._length { |
| let ul = u._length |
| let vl = v._length |
| acc = UInt32(v[i]) + UInt32(u[UInt32(ul) - UInt32(vl) + UInt32(i) - UInt32(j) - UInt32(1)]) + k |
| k = acc >> 16; |
| u[UInt32(ul) - UInt32(vl) + UInt32(i) - UInt32(j) - UInt32(1)] = UInt16(truncatingIfNeeded:acc) |
| } |
| // k must be == 1 here |
| } |
| |
| r[UInt32(ql - j - UInt16(1))] = UInt16(q) |
| // D7: loop on j |
| } |
| |
| r._length = UInt32(ql); |
| |
| r.trimTrailingZeros() |
| |
| return .noError; |
| } |
| |
| fileprivate func integerMultiplyByPowerOf10<T:VariableLengthNumber>(_ result: inout T, _ left: T, _ p: Int) -> NSDecimalNumber.CalculationError { |
| var power = p |
| if power == 0 { |
| result = left |
| return .noError |
| } |
| let isNegative = power < 0 |
| if isNegative { |
| power = -power |
| } |
| result = left |
| |
| let maxpow10 = pow10.count - 1 |
| var error:NSDecimalNumber.CalculationError = .noError |
| |
| while power > maxpow10 { |
| var big = T() |
| |
| power -= maxpow10 |
| let p10 = pow10[maxpow10] |
| |
| if !isNegative { |
| error = integerMultiply(&big,result,p10) |
| } else { |
| error = integerDivide(&big,result,p10) |
| } |
| |
| if error != .noError && error != .lossOfPrecision { |
| return error; |
| } |
| |
| for i in 0..<big._length { |
| result[i] = big[i] |
| } |
| |
| result._length = big._length |
| } |
| |
| var big = T() |
| |
| // Handle the rest of the power (<= maxpow10) |
| let p10 = pow10[Int(power)] |
| |
| if !isNegative { |
| error = integerMultiply(&big, result, p10) |
| } else { |
| error = integerDivide(&big, result, p10) |
| } |
| |
| for i in 0..<big._length { |
| result[i] = big[i] |
| } |
| |
| result._length = big._length |
| |
| return error; |
| } |
| |
| public func NSDecimalRound(_ result: UnsafeMutablePointer<Decimal>, _ number: UnsafePointer<Decimal>, _ scale: Int, _ roundingMode: NSDecimalNumber.RoundingMode) { |
| NSDecimalCopy(result,number) // this is unnecessary if they are the same address, but we can't test that here |
| result.pointee.round(scale: scale,roundingMode: roundingMode) |
| } |
| // Rounds num to the given scale using the given mode. |
| // result may be a pointer to same space as num. |
| // scale indicates number of significant digits after the decimal point |
| |
| public func NSDecimalNormalize(_ a: UnsafeMutablePointer<Decimal>, _ b: UnsafeMutablePointer<Decimal>, _ roundingMode: NSDecimalNumber.RoundingMode) -> NSDecimalNumber.CalculationError { |
| var diffexp = a.pointee.__exponent - b.pointee.__exponent |
| var result = Decimal() |
| |
| // |
| // If the two numbers share the same exponents, |
| // the normalisation is already done |
| // |
| if diffexp == 0 { |
| return .noError |
| } |
| |
| // |
| // Put the smallest of the two in aa |
| // |
| var aa: UnsafeMutablePointer<Decimal> |
| var bb: UnsafeMutablePointer<Decimal> |
| |
| if diffexp < 0 { |
| aa = b |
| bb = a |
| diffexp = -diffexp |
| } else { |
| aa = a |
| bb = b |
| } |
| |
| // |
| // Build a backup for aa |
| // |
| var backup = Decimal() |
| |
| NSDecimalCopy(&backup,aa) |
| |
| // |
| // Try to multiply aa to reach the same exponent level than bb |
| // |
| |
| if integerMultiplyByPowerOf10(&result, aa.pointee, Int(diffexp)) == .noError { |
| // Succeed. Adjust the length/exponent info |
| // and return no errorNSDecimalNormalize |
| aa.pointee.copyMantissa(from: result) |
| aa.pointee._exponent = bb.pointee._exponent |
| return .noError; |
| } |
| |
| // |
| // Failed, restart from scratch |
| // |
| NSDecimalCopy(aa, &backup); |
| |
| // |
| // What is the maximum pow10 we can apply to aa ? |
| // |
| let logBase10of2to16 = 4.81647993 |
| let aaLength = aa.pointee._length |
| let maxpow10 = Int8(floor(Double(Decimal.maxSize - aaLength) * logBase10of2to16)) |
| |
| // |
| // Divide bb by this value |
| // |
| _ = integerMultiplyByPowerOf10(&result, bb.pointee, Int(maxpow10 - diffexp)) |
| |
| bb.pointee.copyMantissa(from: result) |
| bb.pointee._exponent -= Int32(maxpow10 - diffexp); |
| |
| // |
| // If bb > 0 multiply aa by the same value |
| // |
| if !bb.pointee.isZero { |
| _ = integerMultiplyByPowerOf10(&result, aa.pointee, Int(maxpow10)) |
| aa.pointee.copyMantissa(from: result) |
| aa.pointee._exponent -= Int32(maxpow10) |
| } else { |
| bb.pointee._exponent = aa.pointee._exponent; |
| } |
| |
| // |
| // the two exponents are now identical, but we've lost some digits in the operation. |
| // |
| return .lossOfPrecision; |
| } |
| |
| public func NSDecimalAdd(_ result: UnsafeMutablePointer<Decimal>, _ leftOperand: UnsafePointer<Decimal>, _ rightOperand: UnsafePointer<Decimal>, _ roundingMode: NSDecimalNumber.RoundingMode) -> NSDecimalNumber.CalculationError { |
| if leftOperand.pointee.isNaN || rightOperand.pointee.isNaN { |
| result.pointee.setNaN() |
| return .overflow |
| } |
| if leftOperand.pointee.isZero { |
| NSDecimalCopy(result, rightOperand) |
| return .noError |
| } else if rightOperand.pointee.isZero { |
| NSDecimalCopy(result, leftOperand) |
| return .noError |
| } else { |
| var a = Decimal() |
| var b = Decimal() |
| var error:NSDecimalNumber.CalculationError = .noError |
| |
| NSDecimalCopy(&a,leftOperand) |
| NSDecimalCopy(&b,rightOperand) |
| |
| let normalizeError = NSDecimalNormalize(&a, &b,roundingMode) |
| |
| if a.isZero { |
| NSDecimalCopy(result,&b) |
| return normalizeError |
| } |
| if b.isZero { |
| NSDecimalCopy(result,&a) |
| return normalizeError |
| } |
| |
| result.pointee._exponent = a._exponent |
| |
| if a.isNegative == b.isNegative { |
| var big = WideDecimal() |
| result.pointee.isNegative = a.isNegative |
| |
| // No possible error here. |
| _ = integerAdd(&big,&a,&b) |
| |
| if big._length > Decimal.maxSize { |
| var exponent:Int32 = 0 |
| error = fitMantissa(&big, &exponent, roundingMode) |
| |
| let newExponent = result.pointee._exponent + exponent |
| |
| // Just to be sure! |
| if newExponent > Int32(Int8.max) { |
| result.pointee.setNaN() |
| return .overflow |
| } |
| result.pointee._exponent = newExponent |
| } |
| let length = min(Decimal.maxSize,big._length) |
| for i in 0..<length { |
| result.pointee[i] = big[i] |
| } |
| result.pointee._length = length |
| } else { // not the same sign |
| let comparison = mantissaCompare(a,b) |
| |
| switch comparison { |
| case .orderedSame: |
| result.pointee.setZero() |
| case .orderedAscending: |
| _ = integerSubtract(&result.pointee,&b,&a) |
| result.pointee.isNegative = b.isNegative |
| case .orderedDescending: |
| _ = integerSubtract(&result.pointee,&a,&b) |
| result.pointee.isNegative = a.isNegative |
| } |
| } |
| result.pointee._isCompact = 0 |
| NSDecimalCompact(result) |
| return error == .noError ? normalizeError : error |
| } |
| } |
| |
| fileprivate func integerAdd(_ result: inout WideDecimal, _ left: inout Decimal, _ right: inout Decimal) -> NSDecimalNumber.CalculationError { |
| var i:UInt32 = 0 |
| var carry:UInt16 = 0 |
| var accumulator:UInt32 = 0 |
| |
| let c:UInt32 = min(left._length, right._length) |
| |
| while i < c { |
| let li = UInt32(left[i]) |
| let ri = UInt32(right[i]) |
| accumulator = li + ri + UInt32(carry) |
| carry = UInt16(truncatingIfNeeded:accumulator >> 16) |
| result[i] = UInt16(truncatingIfNeeded:accumulator) |
| i += 1 |
| } |
| |
| while i < left._length { |
| if carry != 0 { |
| let li = UInt32(left[i]) |
| accumulator = li + UInt32(carry) |
| carry = UInt16(truncatingIfNeeded:accumulator >> 16) |
| result[i] = UInt16(truncatingIfNeeded:accumulator) |
| i += 1 |
| } else { |
| while i < left._length { |
| result[i] = left[i] |
| i += 1 |
| } |
| break |
| } |
| } |
| while i < right._length { |
| if carry != 0 { |
| let ri = UInt32(right[i]) |
| accumulator = ri + UInt32(carry) |
| carry = UInt16(truncatingIfNeeded:accumulator >> 16) |
| result[i] = UInt16(truncatingIfNeeded:accumulator) |
| i += 1 |
| } else { |
| while i < right._length { |
| result[i] = right[i] |
| i += 1 |
| } |
| break |
| } |
| } |
| |
| if carry != 0 { |
| if result._length < i { |
| result._length = i |
| return .overflow |
| } else { |
| result[i] = carry |
| i += 1 |
| } |
| } |
| result._length = i; |
| return .noError; |
| } |
| |
| // integerSubtract: Subtract b from a, put the result in result, and |
| // modify resultLen to match the length of the result. |
| // Result may be a pointer to same space as a or b. |
| // resultLen must be >= Max(aLen,bLen). |
| // Could return NSCalculationOverflow if b > a. In this case 0 - result |
| // give b-a... |
| // |
| fileprivate func integerSubtract(_ result: inout Decimal, _ left: inout Decimal, _ right: inout Decimal) -> NSDecimalNumber.CalculationError { |
| var i:UInt32 = 0 |
| var carry:UInt16 = 1 |
| var accumulator:UInt32 = 0 |
| |
| let c:UInt32 = min(left._length, right._length) |
| |
| while i < c { |
| let li = UInt32(left[i]) |
| let ri = UInt32(right[i]) |
| accumulator = 0xffff + li - ri + UInt32(carry) |
| carry = UInt16(truncatingIfNeeded:accumulator >> 16) |
| result[i] = UInt16(truncatingIfNeeded:accumulator) |
| i += 1 |
| } |
| |
| while i < left._length { |
| if carry != 0 { |
| let li = UInt32(left[i]) |
| accumulator = 0xffff + li // + no carry |
| carry = UInt16(truncatingIfNeeded:accumulator >> 16) |
| result[i] = UInt16(truncatingIfNeeded:accumulator) |
| i += 1 |
| } else { |
| while i < left._length { |
| result[i] = left[i] |
| i += 1 |
| } |
| break |
| } |
| } |
| while i < right._length { |
| let ri = UInt32(right[i]) |
| accumulator = 0xffff - ri + UInt32(carry) |
| carry = UInt16(truncatingIfNeeded:accumulator >> 16) |
| result[i] = UInt16(truncatingIfNeeded:accumulator) |
| i += 1 |
| } |
| |
| if carry != 0 { |
| return .overflow |
| } |
| result._length = i; |
| |
| result.trimTrailingZeros() |
| |
| return .noError; |
| } |
| |
| // Exact operations. result may be a pointer to same space as leftOperand or rightOperand |
| |
| public func NSDecimalSubtract(_ result: UnsafeMutablePointer<Decimal>, _ leftOperand: UnsafePointer<Decimal>, _ rightOperand: UnsafePointer<Decimal>, _ roundingMode: NSDecimalNumber.RoundingMode) -> NSDecimalNumber.CalculationError { |
| var r = rightOperand.pointee |
| r.negate() |
| return NSDecimalAdd(result, leftOperand, &r, roundingMode) |
| } |
| // Exact operations. result may be a pointer to same space as leftOperand or rightOperand |
| |
| public func NSDecimalMultiply(_ result: UnsafeMutablePointer<Decimal>, _ leftOperand: UnsafePointer<Decimal>, _ rightOperand: UnsafePointer<Decimal>, _ roundingMode: NSDecimalNumber.RoundingMode) -> NSDecimalNumber.CalculationError { |
| |
| if leftOperand.pointee.isNaN || rightOperand.pointee.isNaN { |
| result.pointee.setNaN() |
| return .overflow |
| } |
| if leftOperand.pointee.isZero || rightOperand.pointee.isZero { |
| result.pointee.setZero() |
| return .noError |
| } |
| |
| var big = WideDecimal() |
| var calculationError:NSDecimalNumber.CalculationError = .noError |
| |
| calculationError = integerMultiply(&big,WideDecimal(leftOperand.pointee),rightOperand.pointee) |
| |
| result.pointee._isNegative = (leftOperand.pointee._isNegative + rightOperand.pointee._isNegative) % 2 |
| |
| var newExponent = leftOperand.pointee._exponent + rightOperand.pointee._exponent |
| |
| if big._length > Decimal.maxSize { |
| var exponent:Int32 = 0 |
| calculationError = fitMantissa(&big, &exponent, roundingMode) |
| newExponent += exponent |
| } |
| |
| for i in 0..<big._length { |
| result.pointee[i] = big[i] |
| } |
| result.pointee._length = big._length |
| result.pointee._isCompact = 0 |
| |
| if newExponent > Int32(Int8.max) { |
| result.pointee.setNaN() |
| return .overflow |
| } |
| result.pointee._exponent = newExponent |
| NSDecimalCompact(result) |
| return calculationError |
| } |
| // Exact operations. result may be a pointer to same space as leftOperand or rightOperand |
| |
| public func NSDecimalDivide(_ result: UnsafeMutablePointer<Decimal>, _ leftOperand: UnsafePointer<Decimal>, _ rightOperand: UnsafePointer<Decimal>, _ roundingMode: NSDecimalNumber.RoundingMode) -> NSDecimalNumber.CalculationError { |
| |
| if leftOperand.pointee.isNaN || rightOperand.pointee.isNaN { |
| result.pointee.setNaN() |
| return .overflow |
| } |
| if rightOperand.pointee.isZero { |
| result.pointee.setNaN() |
| return .divideByZero |
| } |
| if leftOperand.pointee.isZero { |
| result.pointee.setZero() |
| return .noError |
| } |
| var a = Decimal() |
| var b = Decimal() |
| var big = WideDecimal() |
| var exponent:Int32 = 0 |
| |
| NSDecimalCopy(&a, leftOperand) |
| NSDecimalCopy(&b, rightOperand) |
| |
| /* If the precision of the left operand is much smaller |
| * than that of the right operand (for example, |
| * 20 and 0.112314123094856724234234572), then the |
| * difference in their exponents is large and a lot of |
| * precision will be lost below. This is particularly |
| * true as the difference approaches 38 or larger. |
| * Normalizing here looses some precision on the |
| * individual operands, but often produces a more |
| * accurate result later. I chose 19 arbitrarily |
| * as half of the magic 38, so that normalization |
| * doesn't always occur. */ |
| if (19 <= Int(a._exponent - b._exponent)) { |
| _ = NSDecimalNormalize(&a, &b, roundingMode); |
| /* We ignore the small loss of precision this may |
| * induce in the individual operands. */ |
| |
| /* Sometimes the normalization done previously is inappropriate and |
| * forces one of the operands to 0. If this happens, restore both. */ |
| if a.isZero || b.isZero { |
| NSDecimalCopy(&a, leftOperand); |
| NSDecimalCopy(&b, rightOperand); |
| } |
| } |
| |
| _ = integerMultiplyByPowerOf10(&big, WideDecimal(a), 38) // Trust me, it's 38 ! |
| _ = integerDivide(&big, big, b) |
| _ = fitMantissa(&big, &exponent, .down) |
| |
| let length = min(big._length,Decimal.maxSize) |
| for i in 0..<length { |
| result.pointee[i] = big[i] |
| } |
| |
| result.pointee._length = length |
| |
| result.pointee.isNegative = a._isNegative != b._isNegative |
| |
| exponent = a._exponent - b._exponent - 38 + exponent |
| if exponent < Int32(Int8.min) { |
| result.pointee.setNaN() |
| return .underflow |
| } |
| if exponent > Int32(Int8.max) { |
| result.pointee.setNaN() |
| return .overflow; |
| } |
| result.pointee._exponent = Int32(exponent) |
| result.pointee._isCompact = 0 |
| NSDecimalCompact(result) |
| return .noError |
| } |
| // Division could be silently inexact; |
| // Exact operations. result may be a pointer to same space as leftOperand or rightOperand |
| |
| public func NSDecimalPower(_ result: UnsafeMutablePointer<Decimal>, _ number: UnsafePointer<Decimal>, _ power: Int, _ roundingMode: NSDecimalNumber.RoundingMode) -> NSDecimalNumber.CalculationError { |
| |
| if number.pointee.isNaN { |
| result.pointee.setNaN() |
| return .overflow |
| } |
| NSDecimalCopy(result,number) |
| return result.pointee.power(UInt(power), roundingMode:roundingMode) |
| } |
| |
| public func NSDecimalMultiplyByPowerOf10(_ result: UnsafeMutablePointer<Decimal>, _ number: UnsafePointer<Decimal>, _ power: Int16, _ roundingMode: NSDecimalNumber.RoundingMode) -> NSDecimalNumber.CalculationError { |
| NSDecimalCopy(result,number) |
| return result.pointee.multiply(byPowerOf10: power) |
| } |
| |
| public func NSDecimalString(_ dcm: UnsafePointer<Decimal>, _ locale: Any?) -> String { |
| guard locale == nil else { |
| fatalError("Locale not supported: \(locale!)") |
| } |
| return dcm.pointee.description |
| } |
| |
| private func multiplyBy10(_ dcm: inout Decimal, andAdd extra:Int) -> NSDecimalNumber.CalculationError { |
| let backup = dcm |
| |
| if multiplyByShort(&dcm, 10) == .noError && addShort(&dcm, UInt16(extra)) == .noError { |
| return .noError |
| } else { |
| dcm = backup // restore the old values |
| return .overflow // this is the only possible error |
| } |
| } |
| |
| fileprivate protocol VariableLengthNumber { |
| var _length: UInt32 { get set } |
| init() |
| subscript(index:UInt32) -> UInt16 { get set } |
| var isZero:Bool { get } |
| mutating func copyMantissa<T:VariableLengthNumber>(from other:T) |
| mutating func zeroMantissa() |
| mutating func trimTrailingZeros() |
| var maxMantissaLength: UInt32 { get } |
| } |
| |
| extension Decimal: VariableLengthNumber { |
| var maxMantissaLength:UInt32 { |
| return Decimal.maxSize |
| } |
| fileprivate mutating func zeroMantissa() { |
| for i in 0..<Decimal.maxSize { |
| self[i] = 0 |
| } |
| } |
| internal mutating func trimTrailingZeros() { |
| if _length > Decimal.maxSize { |
| _length = Decimal.maxSize |
| } |
| while _length != 0 && self[_length - 1] == 0 { |
| _length -= 1 |
| } |
| } |
| fileprivate mutating func copyMantissa<T : VariableLengthNumber>(from other: T) { |
| if other._length > maxMantissaLength { |
| for i in maxMantissaLength..<other._length { |
| guard other[i] == 0 else { |
| fatalError("Loss of precision during copy other[\(i)] \(other[i]) != 0") |
| } |
| } |
| } |
| let length = min(other._length, maxMantissaLength) |
| for i in 0..<length { |
| self[i] = other[i] |
| } |
| self._length = length |
| self._isCompact = 0 |
| } |
| } |
| |
| // Provides a way with dealing with extra-length decimals, used for calculations |
| fileprivate struct WideDecimal : VariableLengthNumber { |
| var maxMantissaLength:UInt32 { |
| return _extraWide ? 17 : 16 |
| } |
| |
| fileprivate mutating func zeroMantissa() { |
| for i in 0..<maxMantissaLength { |
| self[i] = 0 |
| } |
| } |
| fileprivate mutating func trimTrailingZeros() { |
| while _length != 0 && self[_length - 1] == 0 { |
| _length -= 1 |
| } |
| } |
| init() { |
| self.init(false) |
| } |
| |
| fileprivate mutating func copyMantissa<T : VariableLengthNumber>(from other: T) { |
| let length = other is Decimal ? min(other._length,Decimal.maxSize) : other._length |
| for i in 0..<length { |
| self[i] = other[i] |
| } |
| self._length = length |
| } |
| |
| var isZero: Bool { |
| return _length == 0 |
| } |
| |
| var __length: UInt16 |
| var _mantissa: (UInt16, UInt16, UInt16, UInt16, UInt16, UInt16, UInt16, UInt16, |
| UInt16, UInt16, UInt16, UInt16, UInt16, UInt16, UInt16, UInt16, UInt16) |
| // Most uses of this class use 16 shorts, but integer division uses 17 shorts |
| var _extraWide: Bool |
| var _length: UInt32 { |
| get { |
| return UInt32(__length) |
| } |
| set { |
| guard newValue <= maxMantissaLength else { |
| fatalError("Attempt to set a length greater than capacity \(newValue) > \(maxMantissaLength)") |
| } |
| __length = UInt16(newValue) |
| } |
| } |
| init(_ extraWide:Bool = false) { |
| __length = 0 |
| _mantissa = (UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0)) |
| _extraWide = extraWide |
| } |
| init(_ decimal:Decimal) { |
| self.__length = UInt16(decimal._length) |
| self._extraWide = false |
| self._mantissa = (decimal[0],decimal[1],decimal[2],decimal[3],decimal[4],decimal[5],decimal[6],decimal[7],UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0),UInt16(0)) |
| } |
| subscript(index:UInt32) -> UInt16 { |
| get { |
| switch index { |
| case 0: return _mantissa.0 |
| case 1: return _mantissa.1 |
| case 2: return _mantissa.2 |
| case 3: return _mantissa.3 |
| case 4: return _mantissa.4 |
| case 5: return _mantissa.5 |
| case 6: return _mantissa.6 |
| case 7: return _mantissa.7 |
| case 8: return _mantissa.8 |
| case 9: return _mantissa.9 |
| case 10: return _mantissa.10 |
| case 11: return _mantissa.11 |
| case 12: return _mantissa.12 |
| case 13: return _mantissa.13 |
| case 14: return _mantissa.14 |
| case 15: return _mantissa.15 |
| case 16 where _extraWide: return _mantissa.16 // used in integerDivide |
| default: fatalError("Invalid index \(index) for _mantissa") |
| } |
| } |
| set { |
| switch index { |
| case 0: _mantissa.0 = newValue |
| case 1: _mantissa.1 = newValue |
| case 2: _mantissa.2 = newValue |
| case 3: _mantissa.3 = newValue |
| case 4: _mantissa.4 = newValue |
| case 5: _mantissa.5 = newValue |
| case 6: _mantissa.6 = newValue |
| case 7: _mantissa.7 = newValue |
| case 8: _mantissa.8 = newValue |
| case 9: _mantissa.9 = newValue |
| case 10: _mantissa.10 = newValue |
| case 11: _mantissa.11 = newValue |
| case 12: _mantissa.12 = newValue |
| case 13: _mantissa.13 = newValue |
| case 14: _mantissa.14 = newValue |
| case 15: _mantissa.15 = newValue |
| case 16 where _extraWide: _mantissa.16 = newValue |
| default: fatalError("Invalid index \(index) for _mantissa") |
| } |
| } |
| } |
| func toDecimal() -> Decimal { |
| var result = Decimal() |
| result._length = self._length |
| for i in 0..<_length { |
| result[i] = self[i] |
| } |
| return result |
| } |
| } |
| |
| // == Internal (Swifty) functions == |
| |
| extension Decimal { |
| fileprivate var isCompact: Bool { |
| get { |
| return _isCompact != 0 |
| } |
| set { |
| _isCompact = newValue ? 1 : 0 |
| } |
| } |
| fileprivate var isNegative: Bool { |
| get { |
| return _isNegative != 0 |
| } |
| set { |
| _isNegative = newValue ? 1 : 0 |
| } |
| } |
| fileprivate mutating func compact() { |
| if isCompact || isNaN || _length == 0 { |
| return |
| } |
| var newExponent = self._exponent |
| var remainder: UInt16 = 0 |
| // Divide by 10 as much as possible |
| repeat { |
| (remainder,_) = divideByShort(&self,10) |
| newExponent += 1 |
| } while remainder == 0 |
| // Put the non-empty remainder in place |
| _ = multiplyByShort(&self,10) |
| _ = addShort(&self,remainder) |
| newExponent -= 1 |
| // Set the new exponent |
| while newExponent > Int32(Int8.max) { |
| _ = multiplyByShort(&self,10) |
| newExponent -= 1 |
| } |
| _exponent = newExponent |
| isCompact = true |
| } |
| fileprivate mutating func round(scale:Int, roundingMode:RoundingMode) { |
| // scale is the number of digits after the decimal point |
| var s = Int32(scale) + _exponent |
| if s == NSDecimalNoScale || s >= 0 { |
| return |
| } |
| s = -s |
| var remainder: UInt16 = 0 |
| var previousRemainder = false |
| |
| let negative = _isNegative != 0 |
| var newExponent = _exponent + s |
| while s > 4 { |
| if remainder != 0 { |
| previousRemainder = true |
| } |
| (remainder,_) = divideByShort(&self, 10000) |
| s -= 4 |
| } |
| while s > 0 { |
| if remainder != 0 { |
| previousRemainder = true |
| } |
| (remainder,_) = divideByShort(&self, 10) |
| s -= 1 |
| } |
| // If we are on a tie, adjust with premdr. .50001 is equivalent to .6 |
| if previousRemainder && (remainder == 0 || remainder == 5) { |
| remainder += 1; |
| } |
| if remainder != 0 { |
| if negative { |
| switch roundingMode { |
| case .up: |
| break |
| case .bankers: |
| if remainder == 5 && (self[0] & 1) == 0 { |
| remainder += 1 |
| } |
| fallthrough |
| case .plain: |
| if remainder < 5 { |
| break |
| } |
| fallthrough |
| case .down: |
| _ = addShort(&self, 1) |
| } |
| if _length == 0 { |
| _isNegative = 0; |
| } |
| } else { |
| switch roundingMode { |
| case .down: |
| break |
| case .bankers: |
| if remainder == 5 && (self[0] & 1) == 0 { |
| remainder -= 1 |
| } |
| fallthrough |
| case .plain: |
| if remainder < 5 { |
| break |
| } |
| fallthrough |
| case .up: |
| _ = addShort(&self, 1) |
| } |
| } |
| } |
| _isCompact = 0; |
| |
| while newExponent > Int32(Int8.max) { |
| newExponent -= 1; |
| _ = multiplyByShort(&self, 10); |
| } |
| _exponent = newExponent; |
| self.compact(); |
| } |
| internal func compare(to other:Decimal) -> ComparisonResult { |
| // NaN is a special case and is arbitrary ordered before everything else |
| // Conceptually comparing with NaN is bogus anyway but raising or |
| // always returning the same answer will confuse the sorting algorithms |
| if self.isNaN { |
| return other.isNaN ? .orderedSame : .orderedAscending |
| } |
| if other.isNaN { |
| return .orderedDescending |
| } |
| // Check the sign |
| if self._isNegative > other._isNegative { |
| return .orderedAscending |
| } |
| if self._isNegative < other._isNegative { |
| return .orderedDescending |
| } |
| // If one of the two is == 0, the other is bigger |
| // because 0 implies isNegative = 0... |
| if self.isZero && other.isZero { |
| return .orderedSame |
| } |
| if self.isZero { |
| return .orderedAscending |
| } |
| if other.isZero { |
| return .orderedDescending |
| } |
| var selfNormal = self |
| var otherNormal = other |
| _ = NSDecimalNormalize(&selfNormal, &otherNormal, .down) |
| let comparison = mantissaCompare(selfNormal,otherNormal) |
| if selfNormal._isNegative == 1 { |
| if comparison == .orderedDescending { |
| return .orderedAscending |
| } else if comparison == .orderedAscending { |
| return .orderedDescending |
| } else { |
| return .orderedSame |
| } |
| } |
| return comparison |
| } |
| fileprivate subscript(index:UInt32) -> UInt16 { |
| get { |
| switch index { |
| case 0: return _mantissa.0 |
| case 1: return _mantissa.1 |
| case 2: return _mantissa.2 |
| case 3: return _mantissa.3 |
| case 4: return _mantissa.4 |
| case 5: return _mantissa.5 |
| case 6: return _mantissa.6 |
| case 7: return _mantissa.7 |
| default: fatalError("Invalid index \(index) for _mantissa") |
| } |
| } |
| set { |
| switch index { |
| case 0: _mantissa.0 = newValue |
| case 1: _mantissa.1 = newValue |
| case 2: _mantissa.2 = newValue |
| case 3: _mantissa.3 = newValue |
| case 4: _mantissa.4 = newValue |
| case 5: _mantissa.5 = newValue |
| case 6: _mantissa.6 = newValue |
| case 7: _mantissa.7 = newValue |
| default: fatalError("Invalid index \(index) for _mantissa") |
| } |
| } |
| } |
| fileprivate mutating func setNaN() { |
| _length = 0 |
| _isNegative = 1 |
| } |
| fileprivate mutating func setZero() { |
| _length = 0 |
| _isNegative = 0 |
| } |
| fileprivate mutating func multiply(byPowerOf10 power:Int16) -> CalculationError { |
| if isNaN { |
| return .overflow |
| } |
| if isZero { |
| return .noError |
| } |
| let newExponent = _exponent + Int32(power) |
| if newExponent < Int32(Int8.min) { |
| setNaN() |
| return .underflow |
| } |
| if newExponent > Int32(Int8.max) { |
| setNaN() |
| return .overflow |
| } |
| _exponent = newExponent |
| return .noError |
| } |
| fileprivate mutating func power(_ p:UInt, roundingMode:RoundingMode) -> CalculationError { |
| if isNaN { |
| return .overflow |
| } |
| var power = p |
| if power == 0 { |
| _exponent = 0 |
| _length = 1 |
| _isNegative = 0 |
| self[0] = 1 |
| _isCompact = 1 |
| return .noError |
| } else if power == 1 { |
| return .noError |
| } |
| |
| var temporary = Decimal(1) |
| var error:CalculationError = .noError |
| |
| while power > 1 { |
| if power % 2 == 1 { |
| let previousError = error |
| var leftOp = temporary |
| error = NSDecimalMultiply(&temporary, &leftOp, &self, roundingMode) |
| |
| if previousError != .noError { // FIXME is this the intent? |
| error = previousError |
| } |
| |
| if error == .overflow || error == .underflow { |
| setNaN() |
| return error |
| } |
| power -= 1 |
| } |
| if power != 0 { |
| let previousError = error |
| var leftOp = self |
| var rightOp = self |
| error = NSDecimalMultiply(&self, &leftOp, &rightOp, roundingMode) |
| |
| if previousError != .noError { // FIXME is this the intent? |
| error = previousError |
| } |
| |
| if error == .overflow || error == .underflow { |
| setNaN() |
| return error |
| } |
| power /= 2 |
| } |
| } |
| let previousError = error |
| var rightOp = self |
| error = NSDecimalMultiply(&self, &temporary, &rightOp, roundingMode) |
| |
| if previousError != .noError { // FIXME is this the intent? |
| error = previousError |
| } |
| |
| if error == .overflow || error == .underflow { |
| setNaN() |
| return error |
| } |
| |
| return error |
| } |
| } |
| |
| fileprivate let pow10 = [ |
| /*^00*/ Decimal(length: 1, mantissa:( 0x0001,0,0,0,0,0,0,0)), |
| /*^01*/ Decimal(length: 1, mantissa:( 0x000a,0,0,0,0,0,0,0)), |
| /*^02*/ Decimal(length: 1, mantissa:( 0x0064,0,0,0,0,0,0,0)), |
| /*^03*/ Decimal(length: 1, mantissa:( 0x03e8,0,0,0,0,0,0,0)), |
| /*^04*/ Decimal(length: 1, mantissa:( 0x2710,0,0,0,0,0,0,0)), |
| /*^05*/ Decimal(length: 2, mantissa:( 0x86a0, 0x0001,0,0,0,0,0,0)), |
| /*^06*/ Decimal(length: 2, mantissa:( 0x4240, 0x000f,0,0,0,0,0,0)), |
| /*^07*/ Decimal(length: 2, mantissa:( 0x9680, 0x0098,0,0,0,0,0,0)), |
| /*^08*/ Decimal(length: 2, mantissa:( 0xe100, 0x05f5,0,0,0,0,0,0)), |
| /*^09*/ Decimal(length: 2, mantissa:( 0xca00, 0x3b9a,0,0,0,0,0,0)), |
| /*^10*/ Decimal(length: 3, mantissa:( 0xe400, 0x540b, 0x0002,0,0,0,0,0)), |
| /*^11*/ Decimal(length: 3, mantissa:( 0xe800, 0x4876, 0x0017,0,0,0,0,0)), |
| /*^12*/ Decimal(length: 3, mantissa:( 0x1000, 0xd4a5, 0x00e8,0,0,0,0,0)), |
| /*^13*/ Decimal(length: 3, mantissa:( 0xa000, 0x4e72, 0x0918,0,0,0,0,0)), |
| /*^14*/ Decimal(length: 3, mantissa:( 0x4000, 0x107a, 0x5af3,0,0,0,0,0)), |
| /*^15*/ Decimal(length: 4, mantissa:( 0x8000, 0xa4c6, 0x8d7e, 0x0003,0,0,0,0)), |
| /*^16*/ Decimal(length: 4, mantissa:( 0x0000, 0x6fc1, 0x86f2, 0x0023,0,0,0,0)), |
| /*^17*/ Decimal(length: 4, mantissa:( 0x0000, 0x5d8a, 0x4578, 0x0163,0,0,0,0)), |
| /*^18*/ Decimal(length: 4, mantissa:( 0x0000, 0xa764, 0xb6b3, 0x0de0,0,0,0,0)), |
| /*^19*/ Decimal(length: 4, mantissa:( 0x0000, 0x89e8, 0x2304, 0x8ac7,0,0,0,0)), |
| /*^20*/ Decimal(length: 5, mantissa:( 0x0000, 0x6310, 0x5e2d, 0x6bc7, 0x0005,0,0,0)), |
| /*^21*/ Decimal(length: 5, mantissa:( 0x0000, 0xdea0, 0xadc5, 0x35c9, 0x0036,0,0,0)), |
| /*^22*/ Decimal(length: 5, mantissa:( 0x0000, 0xb240, 0xc9ba, 0x19e0, 0x021e,0,0,0)), |
| /*^23*/ Decimal(length: 5, mantissa:( 0x0000, 0xf680, 0xe14a, 0x02c7, 0x152d,0,0,0)), |
| /*^24*/ Decimal(length: 5, mantissa:( 0x0000, 0xa100, 0xcced, 0x1bce, 0xd3c2,0,0,0)), |
| /*^25*/ Decimal(length: 6, mantissa:( 0x0000, 0x4a00, 0x0148, 0x1614, 0x4595, 0x0008,0,0)), |
| /*^26*/ Decimal(length: 6, mantissa:( 0x0000, 0xe400, 0x0cd2, 0xdcc8, 0xb7d2, 0x0052,0,0)), |
| /*^27*/ Decimal(length: 6, mantissa:( 0x0000, 0xe800, 0x803c, 0x9fd0, 0x2e3c, 0x033b,0,0)), |
| /*^28*/ Decimal(length: 6, mantissa:( 0x0000, 0x1000, 0x0261, 0x3e25, 0xce5e, 0x204f,0,0)), |
| /*^29*/ Decimal(length: 7, mantissa:( 0x0000, 0xa000, 0x17ca, 0x6d72, 0x0fae, 0x431e, 0x0001,0)), |
| /*^30*/ Decimal(length: 7, mantissa:( 0x0000, 0x4000, 0xedea, 0x4674, 0x9cd0, 0x9f2c, 0x000c,0)), |
| /*^31*/ Decimal(length: 7, mantissa:( 0x0000, 0x8000, 0x4b26, 0xc091, 0x2022, 0x37be, 0x007e,0)), |
| /*^32*/ Decimal(length: 7, mantissa:( 0x0000, 0x0000, 0xef81, 0x85ac, 0x415b, 0x2d6d, 0x04ee,0)), |
| /*^33*/ Decimal(length: 7, mantissa:( 0x0000, 0x0000, 0x5b0a, 0x38c1, 0x8d93, 0xc644, 0x314d,0)), |
| /*^34*/ Decimal(length: 8, mantissa:( 0x0000, 0x0000, 0x8e64, 0x378d, 0x87c0, 0xbead, 0xed09, 0x0001)), |
| /*^35*/ Decimal(length: 8, mantissa:( 0x0000, 0x0000, 0x8fe8, 0x2b87, 0x4d82, 0x72c7, 0x4261, 0x0013)), |
| /*^36*/ Decimal(length: 8, mantissa:( 0x0000, 0x0000, 0x9f10, 0xb34b, 0x0715, 0x7bc9, 0x97ce, 0x00c0)), |
| /*^37*/ Decimal(length: 8, mantissa:( 0x0000, 0x0000, 0x36a0, 0x00f4, 0x46d9, 0xd5da, 0xee10, 0x0785)), |
| /*^38*/ Decimal(length: 8, mantissa:( 0x0000, 0x0000, 0x2240, 0x098a, 0xc47a, 0x5a86, 0x4ca8, 0x4b3b)) |
| /*^39 is on 9 shorts. */ |
| ] |
| |
| // Copied from Scanner.swift |
| private func decimalSep(_ locale: Locale?) -> String { |
| if let loc = locale { |
| if let sep = loc._bridgeToObjectiveC().object(forKey: .decimalSeparator) as? NSString { |
| return sep._swiftObject |
| } |
| return "." |
| } else { |
| return decimalSep(Locale.current) |
| } |
| } |
| |
| // Copied from Scanner.swift |
| private func isADigit(_ ch: unichar) -> Bool { |
| struct Local { |
| static let set = CharacterSet.decimalDigits |
| } |
| return Local.set.contains(UnicodeScalar(ch)!) |
| } |
| |
| // Copied from Scanner.swift |
| private func numericValue(_ ch: unichar) -> Int { |
| if (ch >= unichar(unicodeScalarLiteral: "0") && ch <= unichar(unicodeScalarLiteral: "9")) { |
| return Int(ch) - Int(unichar(unicodeScalarLiteral: "0")) |
| } else { |
| return __CFCharDigitValue(UniChar(ch)) |
| } |
| } |
| |
| // Could be silently inexact for float and double. |
| extension Scanner { |
| |
| public func scanDecimal(_ dcm: inout Decimal) -> Bool { |
| if let result = scanDecimal() { |
| dcm = result |
| return true |
| } else { |
| return false |
| } |
| |
| } |
| public func scanDecimal() -> Decimal? { |
| |
| var result = Decimal() |
| |
| let string = self._scanString |
| let length = string.length |
| var buf = _NSStringBuffer(string: string, start: self._scanLocation, end: length) |
| |
| let ds_chars = decimalSep(locale).utf16 |
| let ds = ds_chars[ds_chars.startIndex] |
| buf.skip(_skipSet) |
| var neg = false |
| |
| if buf.currentCharacter == unichar(unicodeScalarLiteral: "-") || buf.currentCharacter == unichar(unicodeScalarLiteral: "+") { |
| neg = buf.currentCharacter == unichar(unicodeScalarLiteral: "-") |
| buf.advance() |
| buf.skip(_skipSet) |
| } |
| guard isADigit(buf.currentCharacter) else { |
| return nil |
| } |
| |
| var tooBig = false |
| |
| // build the mantissa |
| repeat { |
| let numeral = numericValue(buf.currentCharacter) |
| if numeral == -1 { |
| break |
| } |
| |
| if tooBig || multiplyBy10(&result,andAdd:numeral) != .noError { |
| tooBig = true |
| if result._exponent == Int32(Int8.max) { |
| repeat { |
| buf.advance() |
| } while isADigit(buf.currentCharacter) |
| return Decimal.nan |
| } |
| result._exponent += 1 |
| } |
| buf.advance() |
| } while isADigit(buf.currentCharacter) |
| |
| // get the decimal point |
| if buf.currentCharacter == ds { |
| buf.advance() |
| // continue to build the mantissa |
| repeat { |
| let numeral = numericValue(buf.currentCharacter) |
| if numeral == -1 { |
| break |
| } |
| if tooBig || multiplyBy10(&result,andAdd:numeral) != .noError { |
| tooBig = true |
| } else { |
| if result._exponent == Int32(Int8.min) { |
| repeat { |
| buf.advance() |
| } while isADigit(buf.currentCharacter) |
| return Decimal.nan |
| } |
| result._exponent -= 1 |
| } |
| buf.advance() |
| } while isADigit(buf.currentCharacter) |
| } |
| |
| if buf.currentCharacter == unichar(unicodeScalarLiteral: "e") || buf.currentCharacter == unichar(unicodeScalarLiteral: "E") { |
| var exponentIsNegative = false |
| var exponent: Int32 = 0 |
| |
| buf.advance() |
| if buf.currentCharacter == unichar(unicodeScalarLiteral: "-") { |
| exponentIsNegative = true |
| buf.advance() |
| } else if buf.currentCharacter == unichar(unicodeScalarLiteral: "+") { |
| buf.advance() |
| } |
| |
| repeat { |
| let numeral = numericValue(buf.currentCharacter) |
| if numeral == -1 { |
| break |
| } |
| exponent = 10 * exponent + Int32(numeral) |
| guard exponent <= 2*Int32(Int8.max) else { |
| return Decimal.nan |
| } |
| |
| buf.advance() |
| } while isADigit(buf.currentCharacter) |
| |
| if exponentIsNegative { |
| exponent = -exponent |
| } |
| exponent += result._exponent |
| guard exponent >= Int32(Int8.min) && exponent <= Int32(Int8.max) else { |
| return Decimal.nan |
| } |
| result._exponent = exponent |
| } |
| |
| result.isNegative = neg |
| |
| // if we get to this point, and have NaN, then the input string was probably "-0" |
| // or some variation on that, and normalize that to zero. |
| if result.isNaN { |
| result = Decimal(0) |
| } |
| |
| result.compact() |
| self._scanLocation = buf.location |
| return result |
| } |
| } |
| |
| extension Decimal : Codable { |
| private enum CodingKeys : Int, CodingKey { |
| case exponent |
| case length |
| case isNegative |
| case isCompact |
| case mantissa |
| } |
| |
| public init(from decoder: Decoder) throws { |
| let container = try decoder.container(keyedBy: CodingKeys.self) |
| let exponent = try container.decode(CInt.self, forKey: .exponent) |
| let length = try container.decode(CUnsignedInt.self, forKey: .length) |
| let isNegative = try container.decode(Bool.self, forKey: .isNegative) |
| let isCompact = try container.decode(Bool.self, forKey: .isCompact) |
| |
| var mantissaContainer = try container.nestedUnkeyedContainer(forKey: .mantissa) |
| var mantissa: (CUnsignedShort, CUnsignedShort, CUnsignedShort, CUnsignedShort, |
| CUnsignedShort, CUnsignedShort, CUnsignedShort, CUnsignedShort) = (0,0,0,0,0,0,0,0) |
| mantissa.0 = try mantissaContainer.decode(CUnsignedShort.self) |
| mantissa.1 = try mantissaContainer.decode(CUnsignedShort.self) |
| mantissa.2 = try mantissaContainer.decode(CUnsignedShort.self) |
| mantissa.3 = try mantissaContainer.decode(CUnsignedShort.self) |
| mantissa.4 = try mantissaContainer.decode(CUnsignedShort.self) |
| mantissa.5 = try mantissaContainer.decode(CUnsignedShort.self) |
| mantissa.6 = try mantissaContainer.decode(CUnsignedShort.self) |
| mantissa.7 = try mantissaContainer.decode(CUnsignedShort.self) |
| |
| self.init(_exponent: exponent, |
| _length: length, |
| _isNegative: CUnsignedInt(isNegative ? 1 : 0), |
| _isCompact: CUnsignedInt(isCompact ? 1 : 0), |
| _reserved: 0, |
| _mantissa: mantissa) |
| } |
| |
| public func encode(to encoder: Encoder) throws { |
| var container = encoder.container(keyedBy: CodingKeys.self) |
| try container.encode(_exponent, forKey: .exponent) |
| try container.encode(_length, forKey: .length) |
| try container.encode(_isNegative == 0 ? false : true, forKey: .isNegative) |
| try container.encode(_isCompact == 0 ? false : true, forKey: .isCompact) |
| |
| var mantissaContainer = container.nestedUnkeyedContainer(forKey: .mantissa) |
| try mantissaContainer.encode(_mantissa.0) |
| try mantissaContainer.encode(_mantissa.1) |
| try mantissaContainer.encode(_mantissa.2) |
| try mantissaContainer.encode(_mantissa.3) |
| try mantissaContainer.encode(_mantissa.4) |
| try mantissaContainer.encode(_mantissa.5) |
| try mantissaContainer.encode(_mantissa.6) |
| try mantissaContainer.encode(_mantissa.7) |
| } |
| } |
