Swift Measures

A Swift package for defining, converting, and composing units of measure.

Overview

Measures provides strongly typed values and units for physical dimensions. It includes SI base and derived units, metric and binary prefixes, commonly used customary and imperial units, and dimensional composition for related units such as area, volume, speed, force, energy, and electrical quantities.

Applications can define domain-specific dimensions by creating a unit type that conforms to Measurable. Values can then be represented with Measure, converted between compatible units, or converted automatically with Converted.

Requirements

• Swift 6.3+

Measures is written in Swift and avoids platform-specific APIs where possible.

Installation

1. Add Measures to the dependencies in your Package.swift file:

   let package: Package = .init(
       ...
       dependencies: [
           .package(
               url: "https://github.com/bikecalc/swift-measures.git",
               from: "2.0.0"
           )
       ],
       ...
   )

2. Add the Measures product to the dependencies of the target that will import it. Replace YourTarget with the name of that target:

   let package: Package = .init(
       ...
       targets: [
           .target(
               name: "YourTarget",
               dependencies: [
                   .product(
                       name: "Measures",
                       package: "swift-measures"
                   )
               ]
           )
       ],
       ...
   )

3. Import the package in your source code:

   import Measures

Demonstration

Keep a Measure in one unit while calculating with another:

@Converted(to: .metersPerSecond)
var speed: Measure<Speed> = .init(36, .kilometersPerHour)
print(speed)
// Prints "10.0 m/s"

speed += .init(18, .kilometersPerHour)
print(speed)
// Prints "15.0 m/s"

speed *= 2
print(speed)
// Prints "30.0 m/s"

print(speed.converted(to: .kilometersPerHour))
// Prints "108.0 km/h"

Beyond the operations shown here, Measure also supports subtraction, division by a scalar, and comparisons.

Documentation

You can read more about this package by visiting the documentation.

Contributing

Everyone is welcome to contribute to Measures. See the Contributing guide to get started.

If you find a bug, please create an issue. Security vulnerabilities should be reported using the instructions in the Security Policy.

Code of Conduct

This project follows a Code of Conduct.

License

Distributed under Apache License v2.0 with Runtime Library Exception. See the License for more information.