Here you can find the source and exercises of the book Swift in Depth, published by Manning.
Each chapter has a playground which can be opened with Xcode. You may find the source and exercises here.
You need Xcode 10 and Swift 4.2.
If you don't see the pages, press cmd+1 to open Xcode's file inspector.
For a better view in Xcode, make sure rendered markedup is enabled. You can do this by going to Editor > Show Rendered Markup.
Enjoy and good luck with the exercises!