test/type/protocol_composition.swift - third_party/swift - Git at Google

 // RUN: %target-typecheck-verify-swift -swift-version 4

 func canonical_empty_protocol() -> Any {
   return 1
 }

 protocol P1 {
   func p1()
   func f(_: Int) -> Int
 }

 protocol P2 : P1 {
   func p2()
 }

 protocol P3 {
   func p3()
 }

 protocol P4 : P3 {
   func p4()
   func f(_: Double) -> Double
 }

 typealias Any1 = protocol<> // expected-error {{'protocol<>' syntax has been removed; use 'Any' instead}}
 typealias Any2 = protocol< > // expected-error {{'protocol<>' syntax has been removed; use 'Any' instead}}

 // Okay to inherit a typealias for Any type.
 protocol P5 : Any { }
 protocol P6 : protocol<> { } // expected-error {{'protocol<>' syntax has been removed; use 'Any' instead}}
 typealias P7 = Any & Any1

 extension Int : P5 { }

 typealias Bogus = P1 & Int // expected-error{{non-protocol, non-class type 'Int' cannot be used within a protocol-constrained type}}

 func testEquality() {
   // Remove duplicates from protocol-conformance types.
   let x1 : (_ : P2 & P4) -> ()
   let x2 : (_ : P3 & P4 & P2 & P1) -> ()
   x1 = x2
   _ = x1

   // Singleton protocol-conformance types, after duplication, are the same as
   // simply naming the protocol type.
   let x3 : (_ : P2 & P1) -> ()
   let x4 : (_ : P2) -> ()
   x3 = x4
   _ = x3

   // Empty protocol-conformance types are empty.
   let x5 : (_ : Any) -> ()
   let x6 : (_ : Any2) -> ()
   x5 = x6
   _ = x5

   let x7 : (_ : P1 & P3) -> ()
   let x8 : (_ : P2) -> ()
   x7 = x8 // expected-error{{cannot assign value of type '(P2) -> ()' to type '(P1 & P3) -> ()'}}
   _ = x7
 }

 // Name lookup into protocol-conformance types
 func testLookup() {
   let x1 : P2 & P1 & P4
   x1.p1()
   x1.p2()
   x1.p3()
   x1.p4()
   var _ : Int = x1.f(1)
   var _ : Double = x1.f(1.0)
 }

 protocol REPLPrintable {
   func replPrint()
 }

 protocol SuperREPLPrintable : REPLPrintable {
   func superReplPrint()
 }

 protocol FooProtocol {
   func format(_ kind: Unicode.Scalar, layout: String) -> String
 }

 struct SuperPrint : REPLPrintable, FooProtocol, SuperREPLPrintable {
   func replPrint() {}
   func superReplPrint() {}
   func format(_ kind: Unicode.Scalar, layout: String) -> String {}
 }

 struct Struct1 {}
 extension Struct1 : REPLPrintable, FooProtocol {
   func replPrint() {}
   func format(_ kind: Unicode.Scalar, layout: String) -> String {}
 }

 func accept_manyPrintable(_: REPLPrintable & FooProtocol) {}

 func return_superPrintable() -> FooProtocol & SuperREPLPrintable {}

 func testConversion() {
   // Conversions for literals.
   var x : REPLPrintable & FooProtocol = Struct1()
   accept_manyPrintable(Struct1())

   // Conversions for nominal types that conform to a number of protocols.
   let sp : SuperPrint
   x = sp
   accept_manyPrintable(sp)

   // Conversions among existential types.
   var x2 : protocol<SuperREPLPrintable, FooProtocol> // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{12-53=SuperREPLPrintable & FooProtocol}}
   x2 = x // expected-error{{value of type 'FooProtocol & REPLPrintable' does not conform to 'FooProtocol & SuperREPLPrintable' in assignment}}
   x = x2

   // Subtyping
   var _ : () -> FooProtocol & SuperREPLPrintable = return_superPrintable

   // FIXME: closures make ABI conversions explicit. rdar://problem/19517003
   var _ : () -> protocol<FooProtocol, REPLPrintable> = { return_superPrintable() } // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{17-53=FooProtocol & REPLPrintable}}
 }

 // Test the parser's splitting of >= into > and =.
 var x : protocol<P5>= 17 // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{9-22=P5=}} expected-error {{'=' must have consistent whitespace on both sides}}
 var y : protocol<P5, P7>= 17 // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{9-26=P5 & P7=}} expected-error {{'=' must have consistent whitespace on both sides}}
 var z : protocol<P5, P7>?=17 // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{9-27=(P5 & P7)?=}}

 typealias A1 = protocol<> // expected-error {{'protocol<>' syntax has been removed; use 'Any' instead}} {{16-26=Any}}
 typealias A2 = protocol<>? // expected-error {{'protocol<>' syntax has been removed; use 'Any' instead}} {{16-27=Any?}}
 typealias B1 = protocol<P1,P2> // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{16-31=P1 & P2}}
 typealias B2 = protocol<P1, P2> // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{16-32=P1 & P2}}
 typealias B3 = protocol<P1 ,P2> // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{16-32=P1 & P2}}
 typealias B4 = protocol<P1 , P2> // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{16-33=P1 & P2}}
 typealias C1 = protocol<Any, P1> // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{16-33=P1}}
 typealias C2 = protocol<P1, Any> // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{16-33=P1}}
 typealias D = protocol<P1> // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{15-27=P1}}
 typealias E = protocol<Any> // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{15-28=Any}}
 typealias F = protocol<Any, Any> // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{15-33=Any}}
 typealias G = protocol<P1>.Type // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{15-27=P1}}
 typealias H = protocol<P1>! // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{15-28=P1!}}
 // expected-warning@-1 {{using '!' is not allowed here; treating this as '?' instead}}
 typealias J = protocol<P1, P2>.Protocol // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{15-31=(P1 & P2)}}
 typealias K = protocol<P1, P2>? // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{15-32=(P1 & P2)?}}

 typealias T01 = P1.Protocol & P2 // expected-error {{non-protocol, non-class type 'P1.Protocol' cannot be used within a protocol-constrained type}}
 typealias T02 = P1.Type & P2 // expected-error {{non-protocol, non-class type 'P1.Type' cannot be used within a protocol-constrained type}}
 typealias T03 = P1? & P2 // expected-error {{non-protocol, non-class type 'P1?' cannot be used within a protocol-constrained type}}
 typealias T04 = P1 & P2! // expected-error {{non-protocol, non-class type 'P2?' cannot be used within a protocol-constrained type}}
 // expected-warning@-1 {{using '!' is not allowed here; treating this as '?' instead}}
 typealias T05 = P1 & P2 -> P3 // expected-error {{single argument function types require parentheses}} {{17-17=(}} {{24-24=)}}
 typealias T06 = P1 -> P2 & P3 // expected-error {{single argument function types require parentheses}} {{17-17=(}} {{19-19=)}}
 typealias T07 = P1 & protocol<P2, P3> // expected-error {{protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{22-38=P2 & P3}}
 func fT07(x: T07) -> P1 & P2 & P3 { return x } // OK, 'P1 & protocol<P2, P3>' is parsed as 'P1 & P2 & P3'.
 let _: P1 & P2 & P3 -> P1 & P2 & P3 = fT07 // expected-error {{single argument function types require parentheses}} {{8-8=(}} {{20-20=)}}

 struct S01: P5 & P6 {}
 struct S02: P5? & P6 {} // expected-error {{non-protocol, non-class type 'P5?' cannot be used within a protocol-constrained type}}
 struct S03: Optional<P5> & P6 {} // expected-error {{non-protocol, non-class type 'Optional<P5>' cannot be used within a protocol-constrained type}}
 struct S04<T : P5 & (P6)> {}
 struct S05<T> where T : P5? & P6 {} // expected-error 2{{non-protocol, non-class type 'P5?' cannot be used within a protocol-constrained type}}

 // SR-3124 - Protocol Composition Often Migrated Incorrectly
 struct S3124<T: protocol<P1, P3>> {} // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{17-34=P1 & P3>}}
 func f3124_1<U where U: protocol<P1, P3>>(x: U)  {} // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{25-42=P1 & P3>}} // expected-error {{'where' clause}}
 func f3124_2<U : protocol<P1>>(x: U)  {} // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{18-31=P1>}}

 // Make sure we correctly form compositions in expression context
 func takesP1AndP2(_: [AnyObject & P1 & P2]) {}

 takesP1AndP2([AnyObject & P1 & P2]())
 takesP1AndP2([Swift.AnyObject & P1 & P2]())
 takesP1AndP2([AnyObject & protocol_composition.P1 & P2]())
 takesP1AndP2([AnyObject & P1 & protocol_composition.P2]())
 takesP1AndP2([DoesNotExist & P1 & P2]()) // expected-error {{use of unresolved identifier 'DoesNotExist'}}
 takesP1AndP2([Swift.DoesNotExist & P1 & P2]()) // expected-error {{module 'Swift' has no member named 'DoesNotExist'}}

 typealias T08 = P1 & inout P2 // expected-error {{'inout' may only be used on parameters}}
 typealias T09 = P1 & __shared P2 // expected-error {{'__shared' may only be used on parameters}}
 typealias T10 = P1 & __owned P2 // expected-error {{'__owned' may only be used on parameters}}
	// RUN: %target-typecheck-verify-swift -swift-version 4

	func canonical_empty_protocol() -> Any {
	return 1
	}

	protocol P1 {
	func p1()
	func f(_: Int) -> Int
	}

	protocol P2 : P1 {
	func p2()
	}

	protocol P3 {
	func p3()
	}

	protocol P4 : P3 {
	func p4()
	func f(_: Double) -> Double
	}

	typealias Any1 = protocol<> // expected-error {{'protocol<>' syntax has been removed; use 'Any' instead}}
	typealias Any2 = protocol< > // expected-error {{'protocol<>' syntax has been removed; use 'Any' instead}}

	// Okay to inherit a typealias for Any type.
	protocol P5 : Any { }
	protocol P6 : protocol<> { } // expected-error {{'protocol<>' syntax has been removed; use 'Any' instead}}
	typealias P7 = Any & Any1

	extension Int : P5 { }

	typealias Bogus = P1 & Int // expected-error{{non-protocol, non-class type 'Int' cannot be used within a protocol-constrained type}}

	func testEquality() {
	// Remove duplicates from protocol-conformance types.
	let x1 : (_ : P2 & P4) -> ()
	let x2 : (_ : P3 & P4 & P2 & P1) -> ()
	x1 = x2
	_ = x1

	// Singleton protocol-conformance types, after duplication, are the same as
	// simply naming the protocol type.
	let x3 : (_ : P2 & P1) -> ()
	let x4 : (_ : P2) -> ()
	x3 = x4
	_ = x3

	// Empty protocol-conformance types are empty.
	let x5 : (_ : Any) -> ()
	let x6 : (_ : Any2) -> ()
	x5 = x6
	_ = x5

	let x7 : (_ : P1 & P3) -> ()
	let x8 : (_ : P2) -> ()
	x7 = x8 // expected-error{{cannot assign value of type '(P2) -> ()' to type '(P1 & P3) -> ()'}}
	_ = x7
	}

	// Name lookup into protocol-conformance types
	func testLookup() {
	let x1 : P2 & P1 & P4
	x1.p1()
	x1.p2()
	x1.p3()
	x1.p4()
	var _ : Int = x1.f(1)
	var _ : Double = x1.f(1.0)
	}

	protocol REPLPrintable {
	func replPrint()
	}

	protocol SuperREPLPrintable : REPLPrintable {
	func superReplPrint()
	}

	protocol FooProtocol {
	func format(_ kind: Unicode.Scalar, layout: String) -> String
	}

	struct SuperPrint : REPLPrintable, FooProtocol, SuperREPLPrintable {
	func replPrint() {}
	func superReplPrint() {}
	func format(_ kind: Unicode.Scalar, layout: String) -> String {}
	}

	struct Struct1 {}
	extension Struct1 : REPLPrintable, FooProtocol {
	func replPrint() {}
	func format(_ kind: Unicode.Scalar, layout: String) -> String {}
	}

	func accept_manyPrintable(_: REPLPrintable & FooProtocol) {}

	func return_superPrintable() -> FooProtocol & SuperREPLPrintable {}

	func testConversion() {
	// Conversions for literals.
	var x : REPLPrintable & FooProtocol = Struct1()
	accept_manyPrintable(Struct1())

	// Conversions for nominal types that conform to a number of protocols.
	let sp : SuperPrint
	x = sp
	accept_manyPrintable(sp)

	// Conversions among existential types.
	var x2 : protocol<SuperREPLPrintable, FooProtocol> // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{12-53=SuperREPLPrintable & FooProtocol}}
	x2 = x // expected-error{{value of type 'FooProtocol & REPLPrintable' does not conform to 'FooProtocol & SuperREPLPrintable' in assignment}}
	x = x2

	// Subtyping
	var _ : () -> FooProtocol & SuperREPLPrintable = return_superPrintable

	// FIXME: closures make ABI conversions explicit. rdar://problem/19517003
	var _ : () -> protocol<FooProtocol, REPLPrintable> = { return_superPrintable() } // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{17-53=FooProtocol & REPLPrintable}}
	}

	// Test the parser's splitting of >= into > and =.
	var x : protocol<P5>= 17 // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{9-22=P5=}} expected-error {{'=' must have consistent whitespace on both sides}}
	var y : protocol<P5, P7>= 17 // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{9-26=P5 & P7=}} expected-error {{'=' must have consistent whitespace on both sides}}
	var z : protocol<P5, P7>?=17 // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{9-27=(P5 & P7)?=}}

	typealias A1 = protocol<> // expected-error {{'protocol<>' syntax has been removed; use 'Any' instead}} {{16-26=Any}}
	typealias A2 = protocol<>? // expected-error {{'protocol<>' syntax has been removed; use 'Any' instead}} {{16-27=Any?}}
	typealias B1 = protocol<P1,P2> // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{16-31=P1 & P2}}
	typealias B2 = protocol<P1, P2> // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{16-32=P1 & P2}}
	typealias B3 = protocol<P1 ,P2> // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{16-32=P1 & P2}}
	typealias B4 = protocol<P1 , P2> // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{16-33=P1 & P2}}
	typealias C1 = protocol<Any, P1> // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{16-33=P1}}
	typealias C2 = protocol<P1, Any> // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{16-33=P1}}
	typealias D = protocol<P1> // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{15-27=P1}}
	typealias E = protocol<Any> // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{15-28=Any}}
	typealias F = protocol<Any, Any> // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{15-33=Any}}
	typealias G = protocol<P1>.Type // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{15-27=P1}}
	typealias H = protocol<P1>! // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{15-28=P1!}}
	// expected-warning@-1 {{using '!' is not allowed here; treating this as '?' instead}}
	typealias J = protocol<P1, P2>.Protocol // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{15-31=(P1 & P2)}}
	typealias K = protocol<P1, P2>? // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{15-32=(P1 & P2)?}}

	typealias T01 = P1.Protocol & P2 // expected-error {{non-protocol, non-class type 'P1.Protocol' cannot be used within a protocol-constrained type}}
	typealias T02 = P1.Type & P2 // expected-error {{non-protocol, non-class type 'P1.Type' cannot be used within a protocol-constrained type}}
	typealias T03 = P1? & P2 // expected-error {{non-protocol, non-class type 'P1?' cannot be used within a protocol-constrained type}}
	typealias T04 = P1 & P2! // expected-error {{non-protocol, non-class type 'P2?' cannot be used within a protocol-constrained type}}
	// expected-warning@-1 {{using '!' is not allowed here; treating this as '?' instead}}
	typealias T05 = P1 & P2 -> P3 // expected-error {{single argument function types require parentheses}} {{17-17=(}} {{24-24=)}}
	typealias T06 = P1 -> P2 & P3 // expected-error {{single argument function types require parentheses}} {{17-17=(}} {{19-19=)}}
	typealias T07 = P1 & protocol<P2, P3> // expected-error {{protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{22-38=P2 & P3}}
	func fT07(x: T07) -> P1 & P2 & P3 { return x } // OK, 'P1 & protocol<P2, P3>' is parsed as 'P1 & P2 & P3'.
	let _: P1 & P2 & P3 -> P1 & P2 & P3 = fT07 // expected-error {{single argument function types require parentheses}} {{8-8=(}} {{20-20=)}}

	struct S01: P5 & P6 {}
	struct S02: P5? & P6 {} // expected-error {{non-protocol, non-class type 'P5?' cannot be used within a protocol-constrained type}}
	struct S03: Optional<P5> & P6 {} // expected-error {{non-protocol, non-class type 'Optional<P5>' cannot be used within a protocol-constrained type}}
	struct S04<T : P5 & (P6)> {}
	struct S05<T> where T : P5? & P6 {} // expected-error 2{{non-protocol, non-class type 'P5?' cannot be used within a protocol-constrained type}}

	// SR-3124 - Protocol Composition Often Migrated Incorrectly
	struct S3124<T: protocol<P1, P3>> {} // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{17-34=P1 & P3>}}
	func f3124_1<U where U: protocol<P1, P3>>(x: U) {} // expected-error {{'protocol<...>' composition syntax has been removed; join the protocols using '&'}} {{25-42=P1 & P3>}} // expected-error {{'where' clause}}
	func f3124_2<U : protocol<P1>>(x: U) {} // expected-error {{'protocol<...>' composition syntax has been removed and is not needed here}} {{18-31=P1>}}

	// Make sure we correctly form compositions in expression context
	func takesP1AndP2(_: [AnyObject & P1 & P2]) {}

	takesP1AndP2([AnyObject & P1 & P2]())
	takesP1AndP2([Swift.AnyObject & P1 & P2]())
	takesP1AndP2([AnyObject & protocol_composition.P1 & P2]())
	takesP1AndP2([AnyObject & P1 & protocol_composition.P2]())
	takesP1AndP2([DoesNotExist & P1 & P2]()) // expected-error {{use of unresolved identifier 'DoesNotExist'}}
	takesP1AndP2([Swift.DoesNotExist & P1 & P2]()) // expected-error {{module 'Swift' has no member named 'DoesNotExist'}}

	typealias T08 = P1 & inout P2 // expected-error {{'inout' may only be used on parameters}}
	typealias T09 = P1 & __shared P2 // expected-error {{'__shared' may only be used on parameters}}
	typealias T10 = P1 & __owned P2 // expected-error {{'__owned' may only be used on parameters}}