Installing Swift

Sprout's logic can be tried in minutes, but only once Swift is on your machine. The good news is that there is one obvious route per computer. The catch is that the Swift language and the SwiftUI screens do not have quite the same requirements.

The rule

Language anywhere; SwiftUI screens need a Mac with Xcode.

The Swift language installs almost everywhere:

• Mac: install Xcode from the Mac App Store. It brings the Swift compiler, the iPhone simulator, and live SwiftUI previews.
• Linux and Windows: download the Swift toolchain from swift.org using the installer for your system.
• iPad or Mac, no setup: the Swift Playgrounds app lets you write and run Swift straight away.

Check that it worked from a terminal:

Then run a single file of Swift directly:

For anything bigger than one file, make a package and let Swift build and run it:

SwiftUI is different. It is one of Apple's frameworks, so building and previewing SwiftUI screens for iPhone needs a Mac with Xcode. On Linux you can write and run plain Swift, but not an iPhone app.

The shortcut

Ask one question: am I writing logic, or drawing screens? Logic (Sprout's streak maths, its rules for a missed day) runs wherever Swift is installed. Screens need Xcode on a Mac.

The common mistake is expecting a Windows or Linux install to preview an iPhone screen. The compiler is the same language; the Apple frameworks are not there.

Drills

Answer fast — trust the rule.

Remember

• Language anywhere; SwiftUI screens need a Mac with Xcode.
• Ask: am I writing logic, or drawing screens?
• swift --version checks; swift file.swift runs one file; swift run runs a package.