async.swift

// RUN: %target-typecheck-verify-swift -target %target-swift-5.1-abi-triple

// REQUIRES: concurrency

// Parsing function declarations with 'async'
func asyncGlobal1()async{}
func asyncGlobal2()asyncthrows{}

func asyncGlobal3()throwsasync{} // expected-error{{'async' must precede 'throws'}}{{28-34=}}{{21-21=async }}

func asyncGlobal3(fn:()throws->Int)rethrowsasync{} // expected-error{{'async' must precede 'rethrows'}}{{50-56=}}{{41-41=async }}

func asyncGlobal4()->Intasync{} // expected-error{{'async' may only occur before '->'}}{{28-34=}}{{21-21=async }}

func asyncGlobal5()->Intasyncthrows{}
// expected-error@-1{{'async' may only occur before '->'}}{{28-34=}}{{21-21=async }}
// expected-error@-2{{'throws' may only occur before '->'}}{{34-41=}}{{21-21=throws }}

func asyncGlobal6()->Intthrowsasync{}
// expected-error@-1{{'throws' may only occur before '->'}}{{28-35=}}{{21-21=throws }}
// expected-error@-2{{'async' may only occur before '->'}}{{35-41=}}{{21-21=async }}

func asyncGlobal7()throws->Intasync{} // expected-error{{'async' may only occur before '->'}}{{35-41=}}{{21-21=async }}

func asyncGlobal8()asyncthrowsasync->async Int async{}
// expected-error@-1{{'async' has already been specified}} {{34-40=}}
// expected-error@-2{{'async' has already been specified}} {{43-49=}}
// expected-error@-3{{'async' has already been specified}} {{53-59=}}

classX{
init()async{}

deinitasync{} // expected-error{{deinitializers cannot have a name}}

func f()async{}

 subscript(x:Int)async->Int{ // expected-error{{expected '->' for subscript element type}}
 // expected-error@-1{{single argument function types require parentheses}}
 // expected-error@-2{{cannot find type 'async' in scope}}
 // expected-note@-3{{cannot use module 'async' as a type}}
get{
return0
}

setasync{ // expected-error{{'set' accessor cannot have specifier 'async'}}
}
}
}

// Parsing function types with 'async'.
typealiasAsyncFunc1=()async->()
typealiasAsyncFunc2=()asyncthrows->()
typealiasAsyncFunc3=()throwsasync->() // expected-error{{'async' must precede 'throws'}}{{34-40=}}{{27-27=async }}

// Parsing type expressions with 'async'.
func testTypeExprs(){
let _ =[()async->()]()
let _ =[()asyncthrows->()]()
let _ =[()throwsasync->()]() // expected-error{{'async' must precede 'throws'}}{{22-28=}}{{15-15=async }}

let _ =[()->async()]() // expected-error{{'async' may only occur before '->'}}{{18-24=}}{{15-15=async }}
}

// Parsing await syntax.
structMyFuture{
func await()->Int{0}
}

func testAwaitExpr()async{
let _ =awaitasyncGlobal1()
letmyFuture=MyFuture()
let _ = myFuture.await()
}

func getIntSomeday()async->Int{5}

func testAsyncLet()async{
asyncletx=awaitgetIntSomeday()
 _ =await x
}

asyncfunc asyncIncorrectly(){} // expected-error{{'async' must be written after the parameter list of a function}}{{1-7=}}{{30-30= async}}