752 lines
27 KiB
Swift
752 lines
27 KiB
Swift
// from https://github.com/Jitsusama/UInt128/blob/master/Sources/UInt128.swift
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//
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// UInt128.swift
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//
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// An implementation of a 128-bit unsigned integer data type not
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// relying on any outside libraries apart from Swift's standard
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// library. It also seeks to implement the entirety of the
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// UnsignedInteger protocol as well as standard functions supported
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// by Swift's native unsigned integer types.
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//
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// Copyright 2017 Joel Gerber
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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// MARK: Error Type
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/// An `ErrorType` for `UInt128` data types. It includes cases
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/// for errors that can occur during string
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/// conversion.
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public enum UInt128Errors : Error {
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/// Input cannot be converted to a UInt128 value.
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case invalidString
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}
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// MARK: - Data Type
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/// A 128-bit unsigned integer value type.
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/// Storage is based upon a tuple of 2, 64-bit, unsigned integers.
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public struct UInt128 {
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// MARK: Instance Properties
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/// Internal value is presented as a tuple of 2 64-bit
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/// unsigned integers.
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internal var value: (upperBits: UInt64, lowerBits: UInt64)
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/// Counts up the significant bits in stored data.
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public var significantBits: UInt128 {
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return UInt128(UInt128.bitWidth - leadingZeroBitCount)
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}
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/// Undocumented private variable required for passing this type
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/// to a BinaryFloatingPoint type. See FloatingPoint.swift.gyb in
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/// the Swift stdlib/public/core directory.
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internal var signBitIndex: Int {
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return 127 - leadingZeroBitCount
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}
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// MARK: Initializers
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/// Designated initializer for the UInt128 type.
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public init(upperBits: UInt64, lowerBits: UInt64) {
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value.upperBits = upperBits
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value.lowerBits = lowerBits
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}
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public init() {
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self.init(upperBits: 0, lowerBits: 0)
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}
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public init(_ source: UInt128) {
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self.init(upperBits: source.value.upperBits,
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lowerBits: source.value.lowerBits)
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}
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/// Initialize a UInt128 value from a string.
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///
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/// - parameter source: the string that will be converted into a
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/// UInt128 value. Defaults to being analyzed as a base10 number,
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/// but can be prefixed with `0b` for base2, `0o` for base8
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/// or `0x` for base16.
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public init(_ source: String) throws {
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guard let result = UInt128._valueFromString(source) else {
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throw UInt128Errors.invalidString
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}
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self = result
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}
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}
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// MARK: - FixedWidthInteger Conformance
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extension UInt128 : FixedWidthInteger {
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// MARK: Instance Properties
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public var nonzeroBitCount: Int {
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return value.lowerBits.nonzeroBitCount + value.upperBits.nonzeroBitCount
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}
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public var leadingZeroBitCount: Int {
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if value.upperBits == 0 {
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return UInt64.bitWidth + value.lowerBits.leadingZeroBitCount
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}
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return value.upperBits.leadingZeroBitCount
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}
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/// Returns the big-endian representation of the integer, changing the byte order if necessary.
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public var bigEndian: UInt128 {
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#if arch(i386) || arch(x86_64) || arch(arm) || arch(arm64)
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return self.byteSwapped
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#else
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return self
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#endif
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}
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/// Returns the little-endian representation of the integer, changing the byte order if necessary.
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public var littleEndian: UInt128 {
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#if arch(i386) || arch(x86_64) || arch(arm) || arch(arm64)
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return self
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#else
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return self.byteSwapped
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#endif
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}
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/// Returns the current integer with the byte order swapped.
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public var byteSwapped: UInt128 {
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return UInt128(upperBits: self.value.lowerBits.byteSwapped,
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lowerBits: self.value.upperBits.byteSwapped)
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}
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// MARK: Initializers
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/// Creates a UInt128 from a given value, with the input's value
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/// truncated to a size no larger than what UInt128 can handle.
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/// Since the input is constrained to an UInt, no truncation needs
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/// to occur, as a UInt is currently 64 bits at the maximum.
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public init(_truncatingBits bits: UInt) {
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self.init(upperBits: 0, lowerBits: UInt64(bits))
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}
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/// Creates an integer from its big-endian representation, changing the
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/// byte order if necessary.
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public init(bigEndian value: UInt128) {
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self = value.bigEndian
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}
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/// Creates an integer from its little-endian representation, changing the
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/// byte order if necessary.
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public init(littleEndian value: UInt128) {
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self = value.littleEndian
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}
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// MARK: Instance Methods
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public func addingReportingOverflow(_ rhs: UInt128) -> (partialValue: UInt128, overflow: Bool) {
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var resultOverflow = false
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let (lowerBits, lowerOverflow) = self.value.lowerBits.addingReportingOverflow(rhs.value.lowerBits)
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var (upperBits, upperOverflow) = self.value.upperBits.addingReportingOverflow(rhs.value.upperBits)
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// If the lower bits overflowed, we need to add 1 to upper bits.
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if lowerOverflow {
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(upperBits, resultOverflow) = upperBits.addingReportingOverflow(1)
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}
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return (partialValue: UInt128(upperBits: upperBits, lowerBits: lowerBits),
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overflow: upperOverflow || resultOverflow)
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}
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public func subtractingReportingOverflow(_ rhs: UInt128) -> (partialValue: UInt128, overflow: Bool) {
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var resultOverflow = false
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let (lowerBits, lowerOverflow) = self.value.lowerBits.subtractingReportingOverflow(rhs.value.lowerBits)
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var (upperBits, upperOverflow) = self.value.upperBits.subtractingReportingOverflow(rhs.value.upperBits)
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// If the lower bits overflowed, we need to subtract (borrow) 1 from the upper bits.
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if lowerOverflow {
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(upperBits, resultOverflow) = upperBits.subtractingReportingOverflow(1)
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}
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return (partialValue: UInt128(upperBits: upperBits, lowerBits: lowerBits),
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overflow: upperOverflow || resultOverflow)
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}
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public func multipliedReportingOverflow(by rhs: UInt128) -> (partialValue: UInt128, overflow: Bool) {
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let multiplicationResult = self.multipliedFullWidth(by: rhs)
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let overflowEncountered = multiplicationResult.high > 0
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return (partialValue: multiplicationResult.low,
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overflow: overflowEncountered)
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}
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public func multipliedFullWidth(by other: UInt128) -> (high: UInt128, low: UInt128.Magnitude) {
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// Bit mask that facilitates masking the lower 32 bits of a 64 bit UInt.
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let lower32 = UInt64(UInt32.max)
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// Decompose lhs into an array of 4, 32 significant bit UInt64s.
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let lhsArray = [
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self.value.upperBits >> 32, /*0*/ self.value.upperBits & lower32, /*1*/
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self.value.lowerBits >> 32, /*2*/ self.value.lowerBits & lower32 /*3*/
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]
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// Decompose rhs into an array of 4, 32 significant bit UInt64s.
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let rhsArray = [
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other.value.upperBits >> 32, /*0*/ other.value.upperBits & lower32, /*1*/
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other.value.lowerBits >> 32, /*2*/ other.value.lowerBits & lower32 /*3*/
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]
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// The future contents of this array will be used to store segment
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// multiplication results.
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var resultArray = [[UInt64]](
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repeating: [UInt64](repeating: 0, count: 4), count: 4
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)
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// Loop through every combination of lhsArray[x] * rhsArray[y]
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for rhsSegment in 0 ..< rhsArray.count {
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for lhsSegment in 0 ..< lhsArray.count {
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let currentValue = lhsArray[lhsSegment] * rhsArray[rhsSegment]
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resultArray[lhsSegment][rhsSegment] = currentValue
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}
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}
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// Perform multiplication similar to pen and paper in 64bit, 32bit masked increments.
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let bitSegment8 = resultArray[3][3] & lower32
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let bitSegment7 = UInt128._variadicAdditionWithOverflowCount(
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resultArray[2][3] & lower32,
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resultArray[3][2] & lower32,
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resultArray[3][3] >> 32) // overflow from bitSegment8
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let bitSegment6 = UInt128._variadicAdditionWithOverflowCount(
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resultArray[1][3] & lower32,
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resultArray[2][2] & lower32,
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resultArray[3][1] & lower32,
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resultArray[2][3] >> 32, // overflow from bitSegment7
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resultArray[3][2] >> 32, // overflow from bitSegment7
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bitSegment7.overflowCount)
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let bitSegment5 = UInt128._variadicAdditionWithOverflowCount(
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resultArray[0][3] & lower32,
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resultArray[1][2] & lower32,
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resultArray[2][1] & lower32,
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resultArray[3][0] & lower32,
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resultArray[1][3] >> 32, // overflow from bitSegment6
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resultArray[2][2] >> 32, // overflow from bitSegment6
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resultArray[3][1] >> 32, // overflow from bitSegment6
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bitSegment6.overflowCount)
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let bitSegment4 = UInt128._variadicAdditionWithOverflowCount(
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resultArray[0][2] & lower32,
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resultArray[1][1] & lower32,
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resultArray[2][0] & lower32,
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resultArray[0][3] >> 32, // overflow from bitSegment5
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resultArray[1][2] >> 32, // overflow from bitSegment5
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resultArray[2][1] >> 32, // overflow from bitSegment5
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resultArray[3][0] >> 32, // overflow from bitSegment5
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bitSegment5.overflowCount)
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let bitSegment3 = UInt128._variadicAdditionWithOverflowCount(
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resultArray[0][1] & lower32,
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resultArray[1][0] & lower32,
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resultArray[0][2] >> 32, // overflow from bitSegment4
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resultArray[1][1] >> 32, // overflow from bitSegment4
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resultArray[2][0] >> 32, // overflow from bitSegment4
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bitSegment4.overflowCount)
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let bitSegment1 = UInt128._variadicAdditionWithOverflowCount(
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resultArray[0][0],
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resultArray[0][1] >> 32, // overflow from bitSegment3
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resultArray[1][0] >> 32, // overflow from bitSegment3
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bitSegment3.overflowCount)
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// Shift and merge the results into 64 bit groups, adding in overflows as we go.
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let lowerLowerBits = UInt128._variadicAdditionWithOverflowCount(
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bitSegment8,
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bitSegment7.truncatedValue << 32)
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let upperLowerBits = UInt128._variadicAdditionWithOverflowCount(
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bitSegment7.truncatedValue >> 32,
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bitSegment6.truncatedValue,
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bitSegment5.truncatedValue << 32,
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lowerLowerBits.overflowCount)
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let lowerUpperBits = UInt128._variadicAdditionWithOverflowCount(
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bitSegment5.truncatedValue >> 32,
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bitSegment4.truncatedValue,
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bitSegment3.truncatedValue << 32,
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upperLowerBits.overflowCount)
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let upperUpperBits = UInt128._variadicAdditionWithOverflowCount(
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bitSegment3.truncatedValue >> 32,
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bitSegment1.truncatedValue,
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lowerUpperBits.overflowCount)
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// Bring the 64bit unsigned integer results together into a high and low 128bit unsigned integer result.
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return (high: UInt128(upperBits: upperUpperBits.truncatedValue, lowerBits: lowerUpperBits.truncatedValue),
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low: UInt128(upperBits: upperLowerBits.truncatedValue, lowerBits: lowerLowerBits.truncatedValue))
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}
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/// Takes a variable amount of 64bit Unsigned Integers and adds them together,
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/// tracking the total amount of overflows that occurred during addition.
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///
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/// - Parameter addends:
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/// Variably sized list of UInt64 values.
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/// - Returns:
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/// A tuple containing the truncated result and a count of the total
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/// amount of overflows that occurred during addition.
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private static func _variadicAdditionWithOverflowCount(_ addends: UInt64...) -> (truncatedValue: UInt64, overflowCount: UInt64) {
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var sum: UInt64 = 0
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var overflowCount: UInt64 = 0
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addends.forEach { addend in
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let interimSum = sum.addingReportingOverflow(addend)
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if interimSum.overflow {
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overflowCount += 1
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}
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sum = interimSum.partialValue
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}
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return (truncatedValue: sum, overflowCount: overflowCount)
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}
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public func dividedReportingOverflow(by rhs: UInt128) -> (partialValue: UInt128, overflow: Bool) {
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guard rhs != 0 else {
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return (self, true)
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}
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let quotient = self.quotientAndRemainder(dividingBy: rhs).quotient
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return (quotient, false)
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}
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public func dividingFullWidth(_ dividend: (high: UInt128, low: UInt128)) -> (quotient: UInt128, remainder: UInt128) {
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return self._quotientAndRemainderFullWidth(dividingBy: dividend)
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}
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public func remainderReportingOverflow(dividingBy rhs: UInt128) -> (partialValue: UInt128, overflow: Bool) {
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guard rhs != 0 else {
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return (self, true)
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}
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let remainder = self.quotientAndRemainder(dividingBy: rhs).remainder
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return (remainder, false)
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}
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public func quotientAndRemainder(dividingBy rhs: UInt128) -> (quotient: UInt128, remainder: UInt128) {
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return rhs._quotientAndRemainderFullWidth(dividingBy: (high: 0, low: self))
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}
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/// Provides the quotient and remainder when dividing the provided value by self.
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internal func _quotientAndRemainderFullWidth(dividingBy dividend: (high: UInt128, low: UInt128)) -> (quotient: UInt128, remainder: UInt128) {
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let divisor = self
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let numeratorBitsToWalk: UInt128
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if dividend.high > 0 {
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numeratorBitsToWalk = dividend.high.significantBits + 128 - 1
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} else if dividend.low == 0 {
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return (0, 0)
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} else {
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numeratorBitsToWalk = dividend.low.significantBits - 1
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}
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// The below algorithm was adapted from:
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// https://en.wikipedia.org/wiki/Division_algorithm#Integer_division_.28unsigned.29_with_remainder
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precondition(self != 0, "Division by 0")
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var quotient = UInt128.min
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var remainder = UInt128.min
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for numeratorShiftWidth in (0...numeratorBitsToWalk).reversed() {
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remainder <<= 1
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remainder |= UInt128._bitFromDoubleWidth(at: numeratorShiftWidth, for: dividend)
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if remainder >= divisor {
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remainder -= divisor
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quotient |= 1 << numeratorShiftWidth
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}
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}
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return (quotient, remainder)
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}
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/// Returns the bit stored at the given position for the provided double width UInt128 input.
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///
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/// - parameter at: position to grab bit value from.
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/// - parameter for: the double width UInt128 data value to grab the
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/// bit from.
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/// - returns: single bit stored in a UInt128 value.
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internal static func _bitFromDoubleWidth(at bitPosition: UInt128, for input: (high: UInt128, low: UInt128)) -> UInt128 {
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switch bitPosition {
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case 0:
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return input.low & 1
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case 1...127:
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return input.low >> bitPosition & 1
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case 128:
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return input.high & 1
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default:
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return input.high >> (bitPosition - 128) & 1
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}
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}
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}
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// MARK: - BinaryInteger Conformance
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extension UInt128 {
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// MARK: Instance Properties
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public static var bitWidth : Int { return 128 }
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}
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extension UInt128 : BinaryInteger {
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// MARK: Instance Methods
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public var words: [UInt] {
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return Array(value.lowerBits.words) + Array(value.upperBits.words)
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}
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public var trailingZeroBitCount: Int {
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if value.lowerBits == 0 {
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return UInt64.bitWidth + value.upperBits.trailingZeroBitCount
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}
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return value.lowerBits.trailingZeroBitCount
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}
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// MARK: Initializers
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public init?<T : BinaryFloatingPoint>(exactly source: T) {
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if source.isZero {
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self = UInt128()
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}
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else if source.exponent < 0 || source.rounded() != source {
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return nil
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}
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else {
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self = UInt128(UInt64(source))
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}
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}
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public init<T : BinaryFloatingPoint>(_ source: T) {
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self.init(UInt64(source))
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}
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// MARK: Type Methods
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public static func /(lhs: UInt128, rhs: UInt128) -> UInt128 {
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let result = lhs.dividedReportingOverflow(by: rhs)
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return result.partialValue
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}
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public static func /=(lhs: inout UInt128, rhs: UInt128) {
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lhs = lhs / rhs
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}
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public static func %(lhs: UInt128, rhs: UInt128) -> UInt128 {
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let result = lhs.remainderReportingOverflow(dividingBy: rhs)
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return result.partialValue
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}
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public static func %=(lhs: inout UInt128, rhs: UInt128) {
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lhs = lhs % rhs
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}
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/// Performs a bitwise AND operation on 2 UInt128 data types.
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public static func &=(lhs: inout UInt128, rhs: UInt128) {
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let upperBits = lhs.value.upperBits & rhs.value.upperBits
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let lowerBits = lhs.value.lowerBits & rhs.value.lowerBits
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lhs = UInt128(upperBits: upperBits, lowerBits: lowerBits)
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}
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/// Performs a bitwise OR operation on 2 UInt128 data types.
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public static func |=(lhs: inout UInt128, rhs: UInt128) {
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let upperBits = lhs.value.upperBits | rhs.value.upperBits
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let lowerBits = lhs.value.lowerBits | rhs.value.lowerBits
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lhs = UInt128(upperBits: upperBits, lowerBits: lowerBits)
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}
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/// Performs a bitwise XOR operation on 2 UInt128 data types.
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public static func ^=(lhs: inout UInt128, rhs: UInt128) {
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let upperBits = lhs.value.upperBits ^ rhs.value.upperBits
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let lowerBits = lhs.value.lowerBits ^ rhs.value.lowerBits
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lhs = UInt128(upperBits: upperBits, lowerBits: lowerBits)
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}
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/// Perform a masked right SHIFT operation self.
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///
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/// The masking operation will mask `rhs` against the highest
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/// shift value that will not cause an overflowing shift before
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/// performing the shift. IE: `rhs = 128` will become `rhs = 0`
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/// and `rhs = 129` will become `rhs = 1`.
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public static func &>>=(lhs: inout UInt128, rhs: UInt128) {
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let shiftWidth = rhs.value.lowerBits & 127
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switch shiftWidth {
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case 0: return // Do nothing shift.
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case 1...63:
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let upperBits = lhs.value.upperBits >> shiftWidth
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let lowerBits = (lhs.value.lowerBits >> shiftWidth) + (lhs.value.upperBits << (64 - shiftWidth))
|
|
lhs = UInt128(upperBits: upperBits, lowerBits: lowerBits)
|
|
case 64:
|
|
// Shift 64 means move upper bits to lower bits.
|
|
lhs = UInt128(upperBits: 0, lowerBits: lhs.value.upperBits)
|
|
default:
|
|
let lowerBits = lhs.value.upperBits >> (shiftWidth - 64)
|
|
lhs = UInt128(upperBits: 0, lowerBits: lowerBits)
|
|
}
|
|
}
|
|
|
|
/// Perform a masked left SHIFT operation on self.
|
|
///
|
|
/// The masking operation will mask `rhs` against the highest
|
|
/// shift value that will not cause an overflowing shift before
|
|
/// performing the shift. IE: `rhs = 128` will become `rhs = 0`
|
|
/// and `rhs = 129` will become `rhs = 1`.
|
|
public static func &<<=(lhs: inout UInt128, rhs: UInt128) {
|
|
let shiftWidth = rhs.value.lowerBits & 127
|
|
|
|
switch shiftWidth {
|
|
case 0: return // Do nothing shift.
|
|
case 1...63:
|
|
let upperBits = (lhs.value.upperBits << shiftWidth) + (lhs.value.lowerBits >> (64 - shiftWidth))
|
|
let lowerBits = lhs.value.lowerBits << shiftWidth
|
|
lhs = UInt128(upperBits: upperBits, lowerBits: lowerBits)
|
|
case 64:
|
|
// Shift 64 means move lower bits to upper bits.
|
|
lhs = UInt128(upperBits: lhs.value.lowerBits, lowerBits: 0)
|
|
default:
|
|
let upperBits = lhs.value.lowerBits << (shiftWidth - 64)
|
|
lhs = UInt128(upperBits: upperBits, lowerBits: 0)
|
|
}
|
|
}
|
|
}
|
|
|
|
// MARK: - UnsignedInteger Conformance
|
|
|
|
extension UInt128 : UnsignedInteger {}
|
|
|
|
// MARK: - Hashable Conformance
|
|
|
|
extension UInt128 : Hashable {
|
|
public var hashValue: Int {
|
|
return self.value.lowerBits.hashValue ^ self.value.upperBits.hashValue
|
|
}
|
|
}
|
|
|
|
// MARK: - Numeric Conformance
|
|
|
|
extension UInt128 : Numeric {
|
|
public static func +(lhs: UInt128, rhs: UInt128) -> UInt128 {
|
|
precondition(~lhs >= rhs, "Addition overflow!")
|
|
let result = lhs.addingReportingOverflow(rhs)
|
|
return result.partialValue
|
|
}
|
|
public static func +=(lhs: inout UInt128, rhs: UInt128) {
|
|
lhs = lhs + rhs
|
|
}
|
|
public static func -(lhs: UInt128, rhs: UInt128) -> UInt128 {
|
|
precondition(lhs >= rhs, "Integer underflow")
|
|
let result = lhs.subtractingReportingOverflow(rhs)
|
|
return result.partialValue
|
|
}
|
|
public static func -=(lhs: inout UInt128, rhs: UInt128) {
|
|
lhs = lhs - rhs
|
|
}
|
|
public static func *(lhs: UInt128, rhs: UInt128) -> UInt128 {
|
|
let result = lhs.multipliedReportingOverflow(by: rhs)
|
|
precondition(!result.overflow, "Multiplication overflow!")
|
|
return result.partialValue
|
|
}
|
|
public static func *=(lhs: inout UInt128, rhs: UInt128) {
|
|
lhs = lhs * rhs
|
|
}
|
|
}
|
|
|
|
// MARK: - Equatable Conformance
|
|
|
|
extension UInt128 : Equatable {
|
|
/// Checks if the `lhs` is equal to the `rhs`.
|
|
public static func ==(lhs: UInt128, rhs: UInt128) -> Bool {
|
|
if lhs.value.lowerBits == rhs.value.lowerBits && lhs.value.upperBits == rhs.value.upperBits {
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
}
|
|
|
|
// MARK: - ExpressibleByIntegerLiteral Conformance
|
|
|
|
extension UInt128 : ExpressibleByIntegerLiteral {
|
|
public init(integerLiteral value: IntegerLiteralType) {
|
|
self.init(upperBits: 0, lowerBits: UInt64(value))
|
|
}
|
|
}
|
|
|
|
// MARK: - CustomStringConvertible Conformance
|
|
|
|
extension UInt128 : CustomStringConvertible {
|
|
// MARK: Instance Properties
|
|
|
|
public var description: String {
|
|
return self._valueToString()
|
|
}
|
|
|
|
// MARK: Instance Methods
|
|
|
|
/// Converts the stored value into a string representation.
|
|
/// - parameter radix:
|
|
/// The radix for the base numbering system you wish to have
|
|
/// the type presented in.
|
|
/// - parameter uppercase:
|
|
/// Determines whether letter components of the outputted string will be in
|
|
/// uppercase format or not.
|
|
/// - returns:
|
|
/// String representation of the stored UInt128 value.
|
|
internal func _valueToString(radix: Int = 10, uppercase: Bool = true) -> String {
|
|
precondition((2...36) ~= radix, "radix must be within the range of 2-36.")
|
|
// Simple case.
|
|
if self == 0 {
|
|
return "0"
|
|
}
|
|
|
|
// Will store the final string result.
|
|
var result = String()
|
|
|
|
// Used as the check for indexing through UInt128 for string interpolation.
|
|
var divmodResult = (quotient: self, remainder: UInt128(0))
|
|
// Will hold the pool of possible values.
|
|
let characterPool = uppercase ? "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" : "0123456789abcdefghijklmnopqrstuvwxyz"
|
|
// Go through internal value until every base position is string(ed).
|
|
repeat {
|
|
divmodResult = divmodResult.quotient.quotientAndRemainder(dividingBy: UInt128(radix))
|
|
let index = characterPool.index(characterPool.startIndex, offsetBy: Int(divmodResult.remainder))
|
|
result.insert(characterPool[index], at: result.startIndex)
|
|
} while divmodResult.quotient > 0
|
|
return result
|
|
}
|
|
}
|
|
|
|
// MARK: - CustomDebugStringConvertible Conformance
|
|
|
|
extension UInt128 : CustomDebugStringConvertible {
|
|
public var debugDescription: String {
|
|
return self.description
|
|
}
|
|
}
|
|
|
|
// MARK: - Comparable Conformance
|
|
|
|
extension UInt128 : Comparable {
|
|
public static func <(lhs: UInt128, rhs: UInt128) -> Bool {
|
|
if lhs.value.upperBits < rhs.value.upperBits {
|
|
return true
|
|
} else if lhs.value.upperBits == rhs.value.upperBits && lhs.value.lowerBits < rhs.value.lowerBits {
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
}
|
|
|
|
// MARK: - ExpressibleByStringLiteral Conformance
|
|
|
|
extension UInt128 : ExpressibleByStringLiteral {
|
|
// MARK: Initializers
|
|
|
|
public init(stringLiteral value: StringLiteralType) {
|
|
self.init()
|
|
|
|
if let result = UInt128._valueFromString(value) {
|
|
self = result
|
|
}
|
|
}
|
|
|
|
// MARK: Type Methods
|
|
|
|
internal static func _valueFromString(_ value: String) -> UInt128? {
|
|
let radix = UInt128._determineRadixFromString(value)
|
|
let inputString = radix == 10 ? value : String(value.dropFirst(2))
|
|
|
|
return UInt128(inputString, radix: radix)
|
|
}
|
|
|
|
internal static func _determineRadixFromString(_ string: String) -> Int {
|
|
switch string.prefix(2) {
|
|
case "0b": return 2
|
|
case "0o": return 8
|
|
case "0x": return 16
|
|
default: return 10
|
|
}
|
|
}
|
|
}
|
|
|
|
// MARK: - Codable Conformance
|
|
|
|
extension UInt128 : Codable {
|
|
private enum CodingKeys : String, CodingKey {
|
|
case upperBits = "upperBits", lowerBits = "lowerBits"
|
|
}
|
|
|
|
public init(from decoder: Decoder) throws {
|
|
let container = try decoder.container(keyedBy: CodingKeys.self)
|
|
let upperBits = try container.decode(UInt64.self, forKey: .upperBits)
|
|
let lowerBits = try container.decode(UInt64.self, forKey: .lowerBits)
|
|
self.init(upperBits: upperBits, lowerBits: lowerBits)
|
|
}
|
|
|
|
public func encode(to encoder: Encoder) throws {
|
|
var container = encoder.container(keyedBy: CodingKeys.self)
|
|
try container.encode(value.upperBits, forKey: .upperBits)
|
|
try container.encode(value.lowerBits, forKey: .lowerBits)
|
|
}
|
|
}
|
|
|
|
// MARK: - Deprecated API
|
|
|
|
extension UInt128 {
|
|
/// Initialize a UInt128 value from a string.
|
|
///
|
|
/// - parameter source: the string that will be converted into a
|
|
/// UInt128 value. Defaults to being analyzed as a base10 number,
|
|
/// but can be prefixed with `0b` for base2, `0o` for base8
|
|
/// or `0x` for base16.
|
|
@available(swift, deprecated: 3.2, renamed: "init(_:)")
|
|
public static func fromUnparsedString(_ source: String) throws -> UInt128 {
|
|
return try UInt128(source)
|
|
}
|
|
}
|
|
|
|
// MARK: - BinaryFloatingPoint Interworking
|
|
|
|
extension BinaryFloatingPoint {
|
|
public init(_ value: UInt128) {
|
|
precondition(value.value.upperBits == 0, "Value is too large to fit into a BinaryFloatingPoint until a 128bit BinaryFloatingPoint type is defined.")
|
|
self.init(value.value.lowerBits)
|
|
}
|
|
|
|
public init?(exactly value: UInt128) {
|
|
if value.value.upperBits > 0 {
|
|
return nil
|
|
}
|
|
self = Self(value.value.lowerBits)
|
|
}
|
|
}
|
|
|
|
// MARK: - String Interworking
|
|
|
|
extension String {
|
|
/// Creates a string representing the given value in base 10, or some other
|
|
/// specified base.
|
|
///
|
|
/// - Parameters:
|
|
/// - value: The UInt128 value to convert to a string.
|
|
/// - radix: The base to use for the string representation. `radix` must be
|
|
/// at least 2 and at most 36. The default is 10.
|
|
/// - uppercase: Pass `true` to use uppercase letters to represent numerals
|
|
/// or `false` to use lowercase letters. The default is `false`.
|
|
public init(_ value: UInt128, radix: Int = 10, uppercase: Bool = false) {
|
|
self = value._valueToString(radix: radix, uppercase: uppercase)
|
|
}
|
|
}
|