Swift: get self.description in self.description

Question

I'm trying to modify description output for ErrorProtocol. But this snippet, gives me infinite loop.

enum GeneralError: ErrorProtocol, CustomStringConvertible {
      case NoMemory

      var description: String {
          return String(self).lowercased()
      }
 }

Changing to self.dynamic type gives me a "generalerror".

Is there any way how to get just "nomemory"? Without using conditionals.

I think you will end up needing conditionals for this. – keithbhunter Jun 28 '16 at 15:30 — keithbhunter, Jun 28 '16 at 15:30

score 4 · Accepted Answer · edited May 23 '17 at 12:24

Swift: Convert enum value to String? isn't an exact match for your question, but it really covers the guts of it. In your case, you'll want to change it up a little bit:

enum Error : String, ErrorProtocol, CustomStringConvertible {
    case NoMemory

    var description : String {
        return self.rawValue.lowercaseString
    }
}

This works because the default rawValue for enum cases where the associated type is String is the name of the case.

Alexander · Answer 2 · 2016-06-28T15:51:54.617

0

When you call String(self) in GeneralError.description, you're making the String initializer use your object (self) as a CustomStringConvertible to make a new string. Internally, it does this by calling description on it, hence the recursion

What exactly are you trying to achieve?

edited Jun 28 '16 at 15:51

answered Jun 28 '16 at 15:40

Alexander

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That explains the "why", but I asked for the "what" – Alexander Jun 28 '16 at 15:58

Swift: get self.description in self.description

2 Answers2