A type that supplies a custom description for playground logging.
- Xcode 9.3+
- Swift Standard Library
Playground logging can generate, at a minimum, a structured description of any type. If you want to provide a custom description of your type to be logged in place of the default description, conform to the
Playground logging generates a richer, more specialized description of core types. For example, the contents of a
String are logged, as are the components of an
UIColor. The current playground logging implementation logs specialized descriptions of at least the following types:
UInt, and the other standard library integer types
Playground logging may also be able to support specialized descriptions of other types.
Conforming to the CustomPlaygroundDisplayConvertible Protocol
Custom conformance to your custom type, implement the
playground property. If your implementation returns an instance of one of the types above, that type’s specialized description is used. If you return any other type, a structured description is generated.
If your type has value semantics, the
playground should be unaffected by subsequent mutations, if possible.
If your type’s
playground returns an instance which itself conforms to
Custom, then that type’s
playground will be used, and so on. To prevent infinite loops, playground logging implementations can place a reasonable limit on this kind of chaining.