StructureSwift5.9.0
Mirror
A representation of the substructure and display style of an instance of any type.
struct MirrorA mirror describes the parts that make up a particular instance, such as the instance’s stored properties, collection or tuple elements, or its active enumeration case. Mirrors also provide a “display style” property that suggests how this mirror might be rendered.
Playgrounds and the debugger use the Mirror type to display representations of values of any type. For example, when you pass an instance to the dump(_:_:_:_:) function, a mirror is used to render that instance’s runtime contents.
struct Point {
let x: Int, y: Int
}
let p = Point(x: 21, y: 30)
print(String(reflecting: p))
// Prints "▿ Point
// - x: 21
// - y: 30"To customize the mirror representation of a custom type, add conformance to the CustomReflectable protocol.
Citizens in Swift
Conformances
protocol CustomReflectableA type that explicitly supplies its own mirror.
protocol CustomStringConvertibleA type with a customized textual representation.
Members
init<Subject, C>(Subject, children: C, displayStyle: Mirror.DisplayStyle?, ancestorRepresentation: Mirror.AncestorRepresentation) Creates a mirror representing the given subject with a specified structure.
init<Subject>(Subject, children: KeyValuePairs<String, Any>, displayStyle: Mirror.DisplayStyle?, ancestorRepresentation: Mirror.AncestorRepresentation) Creates a mirror representing the given subject using a dictionary literal for the structure.
init<Subject, C>(Subject, unlabeledChildren: C, displayStyle: Mirror.DisplayStyle?, ancestorRepresentation: Mirror.AncestorRepresentation) Creates a mirror representing the given subject with unlabeled children.
init(reflecting: Any) Creates a mirror that reflects on the given instance.
let children: Mirror.ChildrenA collection of
Childelements describing the structure of the reflected subject.var customMirror: Mirrorvar description: Stringlet displayStyle: Mirror.DisplayStyle?A suggested display style for the reflected subject.
let subjectType: Any.TypeThe static type of the subject being reflected.
var superclassMirror: Mirror?A mirror of the subject’s superclass, if one exists.
func descendant(MirrorPath, MirrorPath...) -> Any? Returns a specific descendant of the reflected subject, or
nilif no such descendant exists.enum AncestorRepresentationThe representation to use for ancestor classes.
enum DisplayStyleA suggestion of how a mirror’s subject is to be interpreted.
typealias ChildAn element of the reflected instance’s structure.
typealias ChildrenThe type used to represent substructure.