Swift Equatable Protocol
I was folling this tutorial for Swift: https://www.raywenderlich.com/125311/make-game-like-candy-crush-spritekit-swift-part-1 and came across this code:
func == (lhs: Cookie, rhs: Cookie) -> Bool {
return lhs.column == rhs.column && lhs.row == rhs.row
}
I wrote exactly that, but Xcode is giving my these errors:
Consecutive declarations on a line must be separated by ';'
Expected declaration operators are only allowed at global scope
I found this code from apple's documentation: https://developer.apple.com/documentation/swift/equatable
Which is very similar to what I wrote. Whats wrong? This seems like a bug to me. I am using Xcode 6 Beta 2
EDIT:
This is my whole Cookie class:
class Cookie: Printable, Hashable {
var column: Int
var row: Int
let cookieType: CookieType
let sprite: SKSpriteNode?
init(column: Int, row: Int, cookieType: CookieType) {
self.column = column
self.row = row
self.cookieType = cookieType
}
var description: String {
return "type:\(cookieType) square:(\(column),\(row))"
}
var hashValue: Int {
return row * 10 + column
}
func ==(lhs: Cookie, rhs: Cookie) -> Bool {
return lhs.column == rhs.column && lhs.row == rhs.row
}
}
Solution 1:
Move this function
func == (lhs: Cookie, rhs: Cookie) -> Bool {
return lhs.column == rhs.column && lhs.row == rhs.row
}
Outside of the cookie class. It makes sense this way since it's overriding the == operator at the global scope when it is used on two Cookies.
Solution 2:
SWIFT 2:
As in swift 2 NSObject
already conforms to Equatable
.You don't need conformance at the top so it's like
class Cookie: NSObject {
...
}
And you need to override isEqual
method as
class Cookie:NSObject{
var column: Int
var row: Int
//..........
override func isEqual(object: AnyObject?) -> Bool {
guard let rhs = object as? Cookie else {
return false
}
let lhs = self
return lhs.column == rhs.column
}
}
This time isEqual
method is inside the class. :)
EDIT for SWIFT 3: Change this method as
override func isEqual(_ object: AnyObject?) -> Bool {
guard let rhs = object as? Cookie else {
return false
}
let lhs = self
return lhs.column == rhs.column
}
Solution 3:
making the class an NSObject solved the equatable problems for me...
class Cookie: NSObject {
...
}
(got the tip from the iOS apprentice tutorials)