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jseanj/JSONParser

Created September 29, 2014 08:34
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  1. jseanj created this gist Sep 29, 2014.
    97 changes: 97 additions & 0 deletions JSONParser
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,97 @@
    import UIKit
    import XCPlayground

    XCPSetExecutionShouldContinueIndefinitely()

    typealias JSON = AnyObject
    typealias JSONDictionary = [String: JSON]
    typealias JSONArray = [JSON]

    let url = "http://api.openweathermap.org/data/2.5/weather?q=London,uk"
    let request = NSURLRequest(URL: NSURL.URLWithString(url))

    final class Box<A> {
    let value: A
    init(_ value: A) {
    self.value = value
    }
    }

    struct Weather {
    let id: Int
    let name: String

    static func create(id: Int)(name: String) -> Weather {
    return Weather(id: id, name: name)
    }
    }

    enum Result<A> {
    case Error(NSError)
    case Value(Box<A>)
    }

    func JSONString(object: JSON?) -> String? {
    return object as? String
    }

    func JSONInt(object: JSON?) -> Int? {
    return object as? Int
    }

    func JSONObject(object: JSON?) -> JSONDictionary? {
    return object as? JSONDictionary
    }

    infix operator >>> {associativity left precedence 150}
    func >>><A, B>(a: A?, f: A->B?) -> B? {
    if let x = a {
    return f(x)
    } else {
    return .None
    }
    }

    func getData(request: NSURLRequest, callback: (Result<Weather>) -> ()) {
    let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
    data, urlResponse, error in
    if let err = error {
    callback(Result.Error(err))
    return
    }

    var jsonErrorOptional: NSError?
    let jsonOptional: JSON! = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions(0), error: &jsonErrorOptional)

    // println(jsonOptional)

    if let err = jsonErrorOptional {
    callback(Result.Error(err))
    return
    }

    if let json = jsonOptional >>> JSONObject {
    if let id = json["id"] >>> JSONInt {
    if let name = json["name"] >>> JSONString {
    let weather = Weather(id: id, name: name)
    callback(Result.Value(Box(weather)))
    return
    }
    }
    }

    }
    task.resume()
    }

    getData(request) {
    result in
    switch result {
    case let .Error(error):
    println(error)
    case let .Value(boxedUser):
    let weather = boxedUser.value
    println(weather.id)
    println(weather.name)
    }
    }