In a surprise announcement during today's WWDC keynote, Apple senior vice president of software engineering, Craig Federighi, unveiled Swift, a new programming language for coding Mac OS X and iOS applications in Cocoa and Cocoa Touch.
Swift works on its own or side by side with the object-oriented language Objective-C, which dates back to the 1980s and first debuted on NeXT hardware. For the past few decades, developers have programmed Mac OS X and iOS apps in Objective-C, so this could herald the beginning of a new era of app development.
Federighi said that Swift is fast, modern, and like "Objective-C without the C." During the keynote, Federighi showed several slides demonstrating Apple's claimed performance boosts for common programming tasks over their equivalents in both Python and Objective-C.
According to Apple's developer notes, Swift can replace entire lines of code with a single character, while named parameters brought forward from Objective-C are "expressed in a clean syntax" that makes APIs in Swift easier to read and maintain. It eliminates entire classes of unsafe code to prevent overflows, while simpler three-character keywords define a variable or constant. On stage, Federighi also spent time introducing Metal, SpriteKit, and SceneKit, all of which are new developer tools for cobbling together animation quickly and easily for console game-like performance.
Still, one of Swift's flashiest features has to be what it calls interactive Playgrounds, which are places that interpret your code in real time and show the results. For example, you can code a loop, and then watch the loop run in a timeline assistant, complete with a graph, and it can also display an animated SpriteKit scene.
Xcode's debugging console now features an interactive language of Swift built in, which lets you evaluate and interact with your app as it runs, or write new code to see how it works in a scripting-like environment.
Interested developers can download Swift immediately by downloading Xcode 6 beta and following the tutorials in the included documentation. Apple says that it will begin accepting submissions for apps coded in Swift this fall on the release of OS X Yosemite and iOS 8. You can also download The Swift Programming Language book for free in the iBooks Store.
Apple today also showed off iOS 8 and Mac OS X Yosemite, both of which will be released in the fall.