Update README

README.md

@@ -14,3 +14,186 @@ To represent 10 minutes.
 
 ## Usage
 
+#### Showcase
+
+```swift
+import Time
+
+let tenMinutes = 10.minutes
+let afterTenMinutes = Date() + 10.minutes
+let tenMinutesAndSome = 10.minutes + 15.seconds
+let tenMinutesInSeconds = 10.minutes.inSeconds
+if 10.minutes > 500.seconds {
+    print("That's right")
+}
+```
+
+#### Basics
+
+**Time** is not just a bunch of `Double` conversion functions. The main advantage of it is that all time units are _strongly-typed_. So, for example:
+
+```swift
+let tenMinutes = 10.minutes
+```
+
+Here `tenMinutes` will actually be of type `TimeInterval<Minute>` (not to be confused with **Foundation**'s `TimeInterval`). There are seven time units available, from nanoseconds to days:
+
+```swift
+public extension Double {
+
+    var seconds: TimeInterval<Second> {
+        return TimeInterval<Second>(self)
+    }
+
+    var minutes: TimeInterval<Minute> {
+        return TimeInterval<Minute>(self)
+    }
+
+    var milliseconds: TimeInterval<Millisecond> {
+        return TimeInterval<Millisecond>(self)
+    }
+
+    var microseconds: TimeInterval<Microsecond> {
+        return TimeInterval<Microsecond>(self)
+    }
+
+    var nanoseconds: TimeInterval<Nanosecond> {
+        return TimeInterval<Nanosecond>(self)
+    }
+
+    var hours: TimeInterval<Hour> {
+        return TimeInterval<Hour>(self)
+    }
+
+    var days: TimeInterval<Day> {
+        return TimeInterval<Day>(self)
+    }
+
+}
+```
+
+#### Operations
+
+You can perform all basic arithmetic operations on time intervals, even of different units:
+
+```swift
+let interval = 10.minutes + 15.seconds - 3.minutes + 2.hours // TimeInterval<Minute>
+let doubled = interval * 2
+
+let seconds = 10.seconds + 3.minutes // TimeInterval<Second>
+```
+
+You can also use these operations on `Date`:
+
+```swift
+let oneHourAfter = Date() + 1.hours
+```
+
+#### Conversions
+
+Time intervals are easily convertible:
+
+```swift
+let twoMinutesInSeconds = 2.minutes.inSeconds // TimeInterval<Second>
+```
+
+You can also convert time interval to **Foundation**'s `TimeInterval`, if needed:
+
+```swift
+let timeInterval = 5.minutes.timeInterval
+```
+
+You can also use `converted(to:)` method:
+
+```swift
+let fiveSecondsInHours = 5.seconds.converted(to: Hour.self)
+// or
+let fiveSecondsInHours: TimeInterval<Hour> = 5.seconds.converted()
+```
+
+Although, in my opinion, you would rarely need to.
+
+#### Comparison
+
+You can compare different time units as well
+
+```swift
+50.minutes < 1.hour
+```
+
+#### Creating your own time units
+
+If, for some reason, you need to create your own time unit, that's super easy to do:
+
+```swift
+public enum Week : TimeUnit {
+
+    public static var toTimeIntervalRatio: Double {
+        return 604800
+    }
+
+}
+```
+
+Now you can use it as any other time unit:
+
+```swift
+let fiveWeeks = TimeInterval<Week>(5)
+```
+
+For the sake of convenience, don't forget to write those handy extensions:
+
+
+```swift
+extension Time.TimeInterval {
+
+    public var inWeeks: Time.TimeInterval<Week> {
+        return converted()
+    }
+
+}
+
+extension Double {
+
+    public var weeks: Time.TimeInterval<Week> {
+        return Time.TimeInterval<Week>(self)
+    }
+
+}
+
+extension Int {
+
+    public var weeks: Time.TimeInterval<Week> {
+        return Time.TimeInterval<Week>(Double(self))
+    }
+
+}
+```
+
+`Time.` prefix is not to confuse the compiler with **Foundation**.
+
+## Disclaimer
+
+**Time** is in very early stage. Some stuff will probably be broken at some point.
+
+## Installation
+
+**Time** is available through [Carthage][carthage-url]. To install, just write into your Cartfile:
+
+```ruby
+github "dreymonde/Time" ~> 0.0.1
+```
+
+You can also use SwiftPM. Just add to your `Package.swift`:
+
+```swift
+import PackageDescription
+
+let package = Package(
+    dependencies: [
+        .Package(url: "https://github.com/dreymonde/Time.git", majorVersion: 0, minor: 0),
+    ]
+)
+```
+
+[carthage-url]: https://github.com/Carthage/Carthage

Tests/TimeTests/TimeTests.swift

@@ -6,9 +6,9 @@
 //  Copyright © 2017 Time. All rights reserved.
 //
 
+import Time
 import Foundation
 import XCTest
-import Time
 
 public enum Week : TimeUnit {
 
@@ -18,6 +18,30 @@ public enum Week : TimeUnit {
 
 }
 
+extension Time.TimeInterval {
+
+    public var inWeeks: Time.TimeInterval<Week> {
+        return converted()
+    }
+
+}
+
+extension Double {
+
+    public var weeks: Time.TimeInterval<Week> {
+        return Time.TimeInterval<Week>(self)
+    }
+
+}
+
+extension Int {
+
+    public var weeks: Time.TimeInterval<Week> {
+        return Time.TimeInterval<Week>(Double(self))
+    }
+
+}
+
 class TimeTests: XCTestCase {
 
     func testSome() {