foreach.swift

// RUN: %target-parse-verify-swift

// Bad containers and ranges
struct BadContainer1 {
}

func bad_containers_1(bc: BadContainer1) {
  for e in bc { } // expected-error{{type 'BadContainer1' does not conform to protocol 'SequenceType'}}
}

struct BadContainer2 : SequenceType { // expected-error{{type 'BadContainer2' does not conform to protocol 'SequenceType'}}
  var generate : Int
}

func bad_containers_2(bc: BadContainer2) {
  for e in bc { }
}

struct BadContainer3 : SequenceType { // expected-error{{type 'BadContainer3' does not conform to protocol 'SequenceType'}}
  func generate() { } // expected-note{{inferred type '()' (by matching requirement 'generate()') is invalid: does not conform to 'GeneratorType'}}
}

func bad_containers_3(bc: BadContainer3) {
  for e in bc { }
}

struct BadGeneratorType1 {
  
}

struct BadContainer4 : SequenceType { // expected-error{{type 'BadContainer4' does not conform to protocol 'SequenceType'}}
  typealias Generator = BadGeneratorType1 // expected-note{{possibly intended match 'Generator' (aka 'BadGeneratorType1') does not conform to 'GeneratorType'}}
  func generate() -> BadGeneratorType1 { }
}

func bad_containers_4(bc: BadContainer4) {
  for e in bc { }
}

// Pattern type-checking

struct GoodRange<Int> : SequenceType, GeneratorType {
  typealias Element = Int
  func next() -> Int? {}

  typealias Generator = GoodRange<Int>
  func generate() -> GoodRange<Int> { return self }
}

struct GoodTupleGeneratorType : SequenceType, GeneratorType {
  typealias Element = (Int, Float)
  func next() -> (Int, Float)? {}

  typealias Generator = GoodTupleGeneratorType
  func generate() -> GoodTupleGeneratorType {}
}

func patterns(gir: GoodRange<Int>, gtr: GoodTupleGeneratorType) {
  var sum : Int
  var sumf : Float
  for i : Int in gir { sum = sum + i }
  for i in gir { sum = sum + i }
  for f : Float in gir { sum = sum + f } // expected-error{{'Int' is not convertible to 'Float'}}

  for (i, f) : (Int, Float) in gtr { sum = sum + i }

  for (i, f) in gtr {
    sum = sum + i
    sumf = sumf + f
    sum = sum + f  // expected-error{{cannot convert value of type 'Float' to expected argument type 'Int'}}
  }

  for (i, _) : (Int, Float) in gtr { sum = sum + i }

  for (i, _) : (Int, Int) in gtr { sum = sum + i } // expected-error{{'Element' (aka '(Int, Float)') is not convertible to '(Int, Int)'}}

  for (i, f) in gtr {}
}

func slices(i_s: [Int], ias: [[Int]]) {
  var sum = 0
  for i in i_s { sum = sum + i }

  for ia in ias {
    for i in ia {
      sum = sum + i
    }
  }
}

func discard_binding() {
  for _ in [0] {}
}

struct X<T> { 
  var value: T
}

struct Gen<T> : GeneratorType {
  func next() -> T? { return nil }
}

struct Seq<T> : SequenceType {
  func generate() -> Gen<T> { return Gen() }
}

func getIntSeq() -> Seq<Int> { return Seq() }

func getOvlSeq() -> Seq<Int> { return Seq() } // expected-note{{found this candidate}}
func getOvlSeq() -> Seq<Double> { return Seq() } // expected-note{{found this candidate}}
func getOvlSeq() -> Seq<X<Int>> { return Seq() } // expected-note{{found this candidate}}

func getGenericSeq<T>() -> Seq<T> { return Seq() }

func getXIntSeq() -> Seq<X<Int>> { return Seq() }

func getXIntSeqIUO() -> Seq<X<Int>>! { return nil }

func testForEachInference() {
  for i in getIntSeq() { }

  // Overloaded sequence resolved contextually
  for i: Int in getOvlSeq() { }
  for d: Double in getOvlSeq() { }

  // Overloaded sequence not resolved contextually
  for v in getOvlSeq() { } // expected-error{{ambiguous use of 'getOvlSeq()'}}

  // Generic sequence resolved contextually
  for i: Int in getGenericSeq() { }
  for d: Double in getGenericSeq() { }
  
  // Inference of generic arguments in the element type from the
  // sequence.
  for x: X in getXIntSeq() { 
    let z = x.value + 1
  }

  for x: X in getOvlSeq() { 
    let z = x.value + 1
  }

  // Inference with implicitly unwrapped optional
  for x: X in getXIntSeqIUO() {
    let z = x.value + 1
  }

  // Range overloading.
  for i: Int8 in 0..<10 { }
  for i: UInt in 0...10 { }
}

func testMatchingPatterns() {
  // <rdar://problem/21428712> for case parse failure
  let myArray : [Int?] = []
  for case .Some(let x) in myArray {
    _ = x
  }

  // <rdar://problem/21392677> for/case/in patterns aren't parsed properly
  class A {}
  class B : A {}
  class C : A {}
  let array : [A] = [A(), B(), C()]
  for case (let x as B) in array {
    _ = x
  }
}

// <rdar://problem/21662365> QoI: diagnostic for for-each over an optional sequence isn't great
func testOptionalSequence() {
  let array : [Int]? = nil
  for x in array {  // expected-error {{value of optional type '[Int]?' not unwrapped; did you mean to use '!' or '?'?}} {{17-17=!}}
  }
}