More than anyone really wants to know about tuples and closures/functions

gistfile1.txt

import UIKit

typealias Tupletype = (a:Int, b:String, c:Double)
let params1 = (1, "Params1", 2.4) // anonymous tuple
let params2 : Tupletype = (1, "Params2", 2.4) // named parameter tuple

// Standard tuple: var myclosure: (Int, String, Double) -> ()
var myclosure = {(a:Int, b:String, c:Double)->() in println("\(a) \(b) \(c)")}
myclosure(params1) // works
// myclosure(params2) // does not work

// Using tuple type: var myclosure2: Tupletype -> ()
var myclosure2:Tupletype->() = {println("\($0.a) \($0.b) \($0.c)")}
myclosure2(params1) // works
myclosure2(params2) // works

// Extra argument in call, expects a tuple argument
// myclosure2(5, "Anonymous Params", 9.8) // does not work
// myclosure2(a:5, b:"Bye", c:9.8) // does not work

// But when passed a proper tuple it works
myclosure2((a:5, b:"ParamTuple", c:9.8)) // works
myclosure2((5, "AnonymousTuple", 9.8)) // works

// Mismatched argument list, does not work
// myclosure2((x:5, y:"Anonymous tuple", z:9.8)) // does not work

// And now onto functions

// Standard function, expects 3 arguments
func myfunction(a: Int, b:String, c:Double){println("\(a) \(b) \(c)")}
myfunction(5, "Whatever", 9.8) // works because this is the standard way to call it
// myfunction(a:5, b:"Bye", c:9.8) // does not work because extraneous argument labels

myfunction(params1) // works when passed a non-labeled tuple
// myfunction(params2) // does not work when passed a parameterized tuple, even though the parameters match

// Function with tuple argument
func myfunction2(tuple:Tupletype){println("\(tuple.a) \(tuple.b) \(tuple.c)")}
myfunction2((5, "AnonymousTuple", 9.8)) // works as expected
myfunction2((a:5, b:"ParamTuple", c:9.8)) // and works with matching tuple names
myfunction2(params1) // works with anonymous tuple
myfunction2(params2) // works with typed labeled tuple
// myfunction2((x:5, y:"MismatchTuple", z:9.8)) // does not work because mismatched param labels