A hard to spot runtime error results if you try to embed the key < in a dictionary. But when converting plain text for embedding in XML, that's one character you need to substitute.
property list
You want to read in a property list to structured data in Swift. The solution – in Swift 4 – is in a Coder, as explained here.
Dictionaries are valuable, perhaps vital for working with property lists, but seldom as flat as examples suggest. Here are some nested examples in real code.
Got a setting that you just can’t get to stick properly? Here’s a listing of preference files for Sierra, and pointers to all sorts of other settings too.
This new version improves control behaviours in the preferences sheet. Is it ready for final release now?
How much more difficult is it to write your own code to handle user preferences, rather than letting UserDefaults handle them?
Adds the ability to export and import libraries of custom predicates, styles, and filters to property list files, independently of preferences – a leap forward.
Implementing file save and file open for Property Lists using Swift 3.
How HelpHelp accesses a large nested Property List files, handles its data as arrays, and uses NSHelpManager.
How to set your Energy Saver sleep settings to what you want, rather than what Apple might want you to.
The Eclectic Light Company 