ios - Store generics in class properties in Swift -

i have own small library doing http requests our api server. have paginated responses want library handle them nicely. desire have array.reduce(). ideally this:

get("http://myapi.com/somedata")   .onpage(initialvalue: [string](), combine: {valuesofar /*[string]*/, jsondata in     if let arrayofstrings = jsondata as? [string] {       string in arrayofstrings {         valuesofar.append(string)       }     }     return valuesofar   })   .oncomplete({finalvalue in     //do stuff finalvalue   }) 

i can't figure out how define though. far have looks this:

func get(url: string) -> session {return session(url)}  class session {   var pagecallback: /*what goes here?*/   var completecallback: /*what goes here?*/   var valuesofar: /*what goes here?*/    func onpage<t>(initialvalue: t, combine: (t, json) -> t) -> session {     valuesofar = initialvalue     pagecallback = combine     return self   }    func oncomplete<t>(callback: (t) -> void) -> session {     completecallback = callback     return self   }    func calledwhennewpagefromserver(jsondata: json) {     valuesofar = pagecallback(valuesofar, jsondata)     if nomorepages {completecallback(valuesofar)}   } } 

i can't figure out type signatures generic properties should be.