Mach IDE

Mach IDE is a private macOS editor with a SwiftUI preview that does not compile the file. It reads the source and draws the views with real SwiftUI. It is not a compiler, and it does not produce a release build.

A normal preview sends every edit through compile and type-check. That wait is the tax. I wanted to see the view by walking the source instead of waiting for a compiler to bless it. Unknown views become placeholders so the rest of the file can still draw.

On 23 August 2026 I ran it against a real production SwiftUI iOS app of 397 files. It evaluated 289 of them all the way through, 73 percent, in a session that could see more than one file. That is the latest dated coverage number I have. About 108 files still do not evaluate. Counting the whole app at once is still too slow. The editor preview of one file is the path I actually use.

The idea is closer to reading a recipe than lighting an oven. A stack with a title and a button becomes a real stack, title, and button on the preview. If the file uses a view Mach does not know yet, that piece shows as a placeholder and the rest can still draw. That is why some files come through and some do not. I am not claiming this is fast. I am claiming that on that August day, most of a real app’s files could be drawn this way.

I keep this on my own machine. There is no public download and no public source. The remaining work is the files that still fail, and a whole-app count that I cannot finish in a sitting. I will update the coverage number when I have a newer dated run.