| //===----------------------------------------------------------------------===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 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 |
| |
| /// A `Measurement` is a model type that holds a `Double` value associated with a `Unit`. |
| /// |
| /// Measurements support a large set of operators, including `+`, `-`, `*`, `/`, and a full set of comparison operators. |
| public struct Measurement<UnitType : Unit> : ReferenceConvertible, Comparable, Equatable, CustomStringConvertible { |
| public typealias ReferenceType = NSMeasurement |
| |
| /// The unit component of the `Measurement`. |
| public let unit: UnitType |
| |
| /// The value component of the `Measurement`. |
| public var value: Double |
| |
| /// Create a `Measurement` given a specified value and unit. |
| public init(value: Double, unit: UnitType) { |
| self.value = value |
| self.unit = unit |
| } |
| |
| public var hashValue: Int { |
| return Int(bitPattern: _CFHashDouble(value)) |
| } |
| |
| public var description: String { |
| return "\(value) \(unit.symbol)" |
| } |
| |
| public var debugDescription: String { |
| return "\(value) \(unit.symbol)" |
| } |
| } |
| |
| /// When a `Measurement` contains a `Dimension` unit, it gains the ability to convert between the kinds of units in that dimension. |
| extension Measurement where UnitType : Dimension { |
| /// Returns a new measurement created by converting to the specified unit. |
| /// |
| /// - parameter otherUnit: A unit of the same `Dimension`. |
| /// - returns: A converted measurement. |
| public func converted(to otherUnit: UnitType) -> Measurement<UnitType> { |
| if unit.isEqual(otherUnit) { |
| return Measurement(value: value, unit: otherUnit) |
| } else { |
| let valueInTermsOfBase = unit.converter.baseUnitValue(fromValue: value) |
| if otherUnit.isEqual(type(of: unit).baseUnit()) { |
| return Measurement(value: valueInTermsOfBase, unit: otherUnit) |
| } else { |
| let otherValueFromTermsOfBase = otherUnit.converter.value(fromBaseUnitValue: valueInTermsOfBase) |
| return Measurement(value: otherValueFromTermsOfBase, unit: otherUnit) |
| } |
| } |
| } |
| |
| /// Converts the measurement to the specified unit. |
| /// |
| /// - parameter otherUnit: A unit of the same `Dimension`. |
| public mutating func convert(to otherUnit: UnitType) { |
| self = converted(to: otherUnit) |
| } |
| |
| } |
| |
| /// Add two measurements of the same Unit. |
| /// - precondition: The `unit` of `lhs` and `rhs` must be `isEqual`. |
| /// - returns: A measurement of value `lhs.value + rhs.value` and unit `lhs.unit`. |
| public func +<UnitType>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Measurement<UnitType> { |
| if lhs.unit.isEqual(rhs.unit) { |
| return Measurement(value: lhs.value + rhs.value, unit: lhs.unit) |
| } else { |
| fatalError("Attempt to add measurements with non-equal units") |
| } |
| } |
| |
| /// Add two measurements of the same Dimension. |
| /// |
| /// If the `unit` of the `lhs` and `rhs` are `isEqual`, then this returns the result of adding the `value` of each `Measurement`. If they are not equal, then this will convert both to the base unit of the `Dimension` and return the result as a `Measurement` of that base unit. |
| /// - returns: The result of adding the two measurements. |
| public func +<UnitType : Dimension>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Measurement<UnitType> { |
| if lhs.unit.isEqual(rhs.unit) { |
| return Measurement(value: lhs.value + rhs.value, unit: lhs.unit) |
| } else { |
| let lhsValueInTermsOfBase = lhs.unit.converter.baseUnitValue(fromValue: lhs.value) |
| let rhsValueInTermsOfBase = rhs.unit.converter.baseUnitValue(fromValue: rhs.value) |
| return Measurement(value: lhsValueInTermsOfBase + rhsValueInTermsOfBase, unit: type(of: lhs.unit).baseUnit()) |
| } |
| } |
| |
| /// Subtract two measurements of the same Unit. |
| /// - precondition: The `unit` of `lhs` and `rhs` must be `isEqual`. |
| /// - returns: A measurement of value `lhs.value - rhs.value` and unit `lhs.unit`. |
| public func -<UnitType>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Measurement<UnitType> { |
| if lhs.unit.isEqual(rhs.unit) { |
| return Measurement(value: lhs.value - rhs.value, unit: lhs.unit) |
| } else { |
| fatalError("Attempt to subtract measurements with non-equal units") |
| } |
| } |
| |
| /// Subtract two measurements of the same Dimension. |
| /// |
| /// If the `unit` of the `lhs` and `rhs` are `==`, then this returns the result of subtracting the `value` of each `Measurement`. If they are not equal, then this will convert both to the base unit of the `Dimension` and return the result as a `Measurement` of that base unit. |
| /// - returns: The result of adding the two measurements. |
| public func -<UnitType : Dimension>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Measurement<UnitType> { |
| if lhs.unit == rhs.unit { |
| return Measurement(value: lhs.value - rhs.value, unit: lhs.unit) |
| } else { |
| let lhsValueInTermsOfBase = lhs.unit.converter.baseUnitValue(fromValue: lhs.value) |
| let rhsValueInTermsOfBase = rhs.unit.converter.baseUnitValue(fromValue: rhs.value) |
| return Measurement(value: lhsValueInTermsOfBase - rhsValueInTermsOfBase, unit: type(of: lhs.unit).baseUnit()) |
| } |
| } |
| |
| /// Multiply a measurement by a scalar value. |
| /// - returns: A measurement of value `lhs.value * rhs` with the same unit as `lhs`. |
| public func *<UnitType>(lhs: Measurement<UnitType>, rhs: Double) -> Measurement<UnitType> { |
| return Measurement(value: lhs.value * rhs, unit: lhs.unit) |
| } |
| |
| /// Multiply a scalar value by a measurement. |
| /// - returns: A measurement of value `lhs * rhs.value` with the same unit as `rhs`. |
| public func *<UnitType>(lhs: Double, rhs: Measurement<UnitType>) -> Measurement<UnitType> { |
| return Measurement(value: lhs * rhs.value, unit: rhs.unit) |
| } |
| |
| /// Divide a measurement by a scalar value. |
| /// - returns: A measurement of value `lhs.value / rhs` with the same unit as `lhs`. |
| public func /<UnitType>(lhs: Measurement<UnitType>, rhs: Double) -> Measurement<UnitType> { |
| return Measurement(value: lhs.value / rhs, unit: lhs.unit) |
| } |
| |
| /// Divide a scalar value by a measurement. |
| /// - returns: A measurement of value `lhs / rhs.value` with the same unit as `rhs`. |
| public func /<UnitType>(lhs: Double, rhs: Measurement<UnitType>) -> Measurement<UnitType> { |
| return Measurement(value: lhs / rhs.value, unit: rhs.unit) |
| } |
| |
| /// Compare two measurements of the same `Unit`. |
| /// - returns: `true` if `lhs.value == rhs.value && lhs.unit == rhs.unit`. |
| public func ==<UnitType>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Bool { |
| return lhs.value == rhs.value && lhs.unit == rhs.unit |
| } |
| |
| /// Compare two measurements of the same `Dimension`. |
| /// |
| /// If `lhs.unit == rhs.unit`, returns `lhs.value == rhs.value`. Otherwise, converts `rhs` to the same unit as `lhs` and then compares the resulting values. |
| /// - returns: `true` if the measurements are equal. |
| public func ==<UnitType : Dimension>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Bool { |
| if lhs.unit == rhs.unit { |
| return lhs.value == rhs.value |
| } else { |
| let rhsInLhs = rhs.converted(to: lhs.unit) |
| return lhs.value == rhsInLhs.value |
| } |
| } |
| |
| /// Compare two measurements of the same `Unit`. |
| /// - note: This function does not check `==` for the `unit` property of `lhs` and `rhs`. |
| /// - returns: `lhs.value < rhs.value` |
| public func <<UnitType>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Bool { |
| return lhs.value < rhs.value |
| } |
| |
| /// Compare two measurements of the same `Dimension`. |
| /// |
| /// If `lhs.unit == rhs.unit`, returns `lhs.value < rhs.value`. Otherwise, converts `rhs` to the same unit as `lhs` and then compares the resulting values. |
| /// - returns: `true` if `lhs` is less than `rhs`. |
| public func <<UnitType : Dimension>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Bool { |
| if lhs.unit == rhs.unit { |
| return lhs.value < rhs.value |
| } else { |
| let rhsInLhs = rhs.converted(to: lhs.unit) |
| return lhs.value < rhsInLhs.value |
| } |
| } |
| |
| /// Compare two measurements of the same `Unit`. |
| /// - note: This function does not check `==` for the `unit` property of `lhs` and `rhs`. |
| /// - returns: `lhs.value > rhs.value` |
| public func ><UnitType>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Bool { |
| return lhs.value > rhs.value |
| } |
| |
| /// Compare two measurements of the same `Dimension`. |
| /// |
| /// If `lhs.unit == rhs.unit`, returns `lhs.value > rhs.value`. Otherwise, converts `rhs` to the same unit as `lhs` and then compares the resulting values. |
| /// - returns: `true` if `lhs` is greater than `rhs`. |
| public func ><UnitType : Dimension>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Bool { |
| if lhs.unit == rhs.unit { |
| return lhs.value > rhs.value |
| } else { |
| let rhsInLhs = rhs.converted(to: lhs.unit) |
| return lhs.value > rhsInLhs.value |
| } |
| } |
| |
| /// Compare two measurements of the same `Unit`. |
| /// - note: This function does not check `==` for the `unit` property of `lhs` and `rhs`. |
| /// - returns: `lhs.value <= rhs.value` |
| public func <=<UnitType>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Bool { |
| return lhs.value <= rhs.value |
| } |
| |
| /// Compare two measurements of the same `Dimension`. |
| /// |
| /// If `lhs.unit == rhs.unit`, returns `lhs.value < rhs.value`. Otherwise, converts `rhs` to the same unit as `lhs` and then compares the resulting values. |
| /// - returns: `true` if `lhs` is less than or equal to `rhs`. |
| public func <=<UnitType : Dimension>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Bool { |
| if lhs.unit == rhs.unit { |
| return lhs.value <= rhs.value |
| } else { |
| let rhsInLhs = rhs.converted(to: lhs.unit) |
| return lhs.value <= rhsInLhs.value |
| } |
| } |
| |
| /// Compare two measurements of the same `Unit`. |
| /// - note: This function does not check `==` for the `unit` property of `lhs` and `rhs`. |
| /// - returns: `lhs.value >= rhs.value` |
| public func >=<UnitType>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Bool { |
| return lhs.value >= rhs.value |
| } |
| |
| /// Compare two measurements of the same `Dimension`. |
| /// |
| /// If `lhs.unit == rhs.unit`, returns `lhs.value >= rhs.value`. Otherwise, converts `rhs` to the same unit as `lhs` and then compares the resulting values. |
| /// - returns: `true` if `lhs` is greater or equal to `rhs`. |
| public func >=<UnitType : Dimension>(lhs: Measurement<UnitType>, rhs: Measurement<UnitType>) -> Bool { |
| if lhs.unit == rhs.unit { |
| return lhs.value >= rhs.value |
| } else { |
| let rhsInLhs = rhs.converted(to: lhs.unit) |
| return lhs.value >= rhsInLhs.value |
| } |
| } |
| |
| // Implementation note: similar to NSArray, NSDictionary, etc., NSMeasurement's import as an ObjC generic type is suppressed by the importer. Eventually we will need a more general purpose mechanism to correctly import generic types. |
| |
| extension Measurement : _ObjectTypeBridgeable { |
| public static func _isBridgedToObjectiveC() -> Bool { |
| return true |
| } |
| |
| @_semantics("convertToObjectiveC") |
| public func _bridgeToObjectiveC() -> NSMeasurement { |
| return NSMeasurement(doubleValue: value, unit: unit) |
| } |
| |
| public static func _forceBridgeFromObjectiveC(_ source: NSMeasurement, result: inout Measurement?) { |
| result = Measurement(value: source.doubleValue, unit: source.unit as! UnitType) |
| } |
| |
| public static func _conditionallyBridgeFromObjectiveC(_ source: NSMeasurement, result: inout Measurement?) -> Bool { |
| if let u = source.unit as? UnitType { |
| result = Measurement(value: source.doubleValue, unit: u) |
| return true |
| } else { |
| return false |
| } |
| } |
| |
| public static func _unconditionallyBridgeFromObjectiveC(_ source: NSMeasurement?) -> Measurement { |
| let u = source!.unit as! UnitType |
| return Measurement(value: source!.doubleValue, unit: u) |
| } |
| } |