properties - How to declare in Swift a function parameter that is a property name -

i want have class can access specified property in class @ runtime. guessing possible if pass closure or function in parameter. example:

class x {      let pointfunction : (thing) -> (cgpoint)      init(pointfunction : (thing) -> (cgpoint)) {         self.pointfunction = pointfunction     }      func action(#thing : thing) {         var p = pointfunction(thing)         ...     } } 

and

class func getposition(thing : thing) -> cgpoint {     return thing.whereami } 

then pass getposition when creating x.

but there syntax can pass in whereami function name? then, in action method can do:

thing.pointfunction 

you need thing->cgpoint. function literal function there:

let x = x(pointfunction: {$0.whereami}) 

if promise whereami method rather property, other tricks (see http://oleb.net/blog/2014/07/swift-instance-methods-curried-functions/), works methods. inexplicably imo swift properties not methods. if were, pass thing.whereami.

that said, you'd have change init take thing -> () -> cgpoint, little more awkward anyway, or you'd have have 2 inits this:

init(pointfunction : (thing) -> (cgpoint)) {     self.pointfunction = pointfunction } convenience init(pointmethod : thing -> () -> cgpoint) {     self.init(pointfunction: {pointmethod($0)()}) } 

so really, {$0.whereami} approach easier work in cases curried approach, , i'd recommend here.