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// RUN: %target-typecheck-verify-swift -enable-bare-slash-regex -disable-availability-checking -enable-experimental-feature ThenStatements
// Required for experimental features
// REQUIRES: asserts
// Required for regex
// REQUIRES: swift_swift_parser
func then(_: Int = 0, x: Int = 0, fn: () -> Void = {}) {}
func testThenStmt(_ x: Int) {
// These are statements
then x // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
then () // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
then (1) // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
then (1, 2) // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
then "" // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
then []
// expected-error@-1 {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
// expected-error@-2 {{empty collection literal requires an explicit type}}
then [0] // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
then if .random() { 0 } else { 1 }
// expected-error@-1 {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
// expected-error@-2 {{'if' may only be used as expression in return, throw, or as the source of an assignment}}
then -1 // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
then ~1 // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
then /abc/ // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
let x: Int = if .random() {
then .zero
} else {
then 0
}
let y = if .random() { then x } else { then 1 }
let _ = if .random() { (); then y } else { then 1 }
// We don't allow labels on 'then' statements.
let _ = switch Bool.random() {
case true:
a: then 0 // expected-error {{labels are only valid on loops, if, and switch statements}}
case false:
then 1
}
}
func testThenFunctionCalls() {
// These should all be treated as function calls.
then()
then(0)
then(x: 0)
then{}
then {}
}
func testThenLabel() {
then: for then in [0] { // expected-warning {{immutable value 'then' was never used; consider replacing with '_' or removing it}}
break then
continue then
}
}
struct S {
var then: Int
func then(_ x: Int) {}
subscript(x: Int) -> Void { () }
mutating func testThenAsMember() -> Int {
do {
then // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
} // expected-error {{expected expression after 'then'}}
then // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
0 // expected-warning {{expression following 'then' is treated as an argument of the 'then'}}
// expected-note@-1 {{indent the expression to silence this warning}}
// Indented is okay.
then // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
0
then;
// expected-error@-1 {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
// expected-error@-2 {{expected expression after 'then'}}
then . foo
// expected-error@-1 {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
// expected-error@-2 {{reference to member 'foo' cannot be resolved without a contextual type}}
// These are expressions.
let _ = then
let _ = self.then
then + 1 // expected-warning {{result of operator '+' is unused}}
then = 2
(then) // expected-warning {{property is accessed but result is unused}}
then is Int
// expected-warning@-1 {{'is' test is always true}}
// expected-warning@-2 {{expression of type 'Bool' is unused}}
then as Int
// expected-warning@-1 {{expression of type 'Int' is unused}}
then as? Int
// expected-warning@-1 {{conditional cast from 'Int' to 'Int' always succeeds}}
// expected-warning@-2 {{expression of type 'Int?' is unused}}
then as! Int
// expected-warning@-1 {{forced cast of 'Int' to same type has no effect}}
// expected-warning@-2 {{expression of type 'Int' is unused}}
then ? 0 : 1 // expected-error {{type 'Int' cannot be used as a boolean; test for '!= 0' instead}}
then! // expected-error {{cannot force unwrap value of non-optional type 'Int'}}
then? // expected-error {{cannot use optional chaining on non-optional value of type 'Int'}}
then.bitWidth // expected-warning {{expression of type 'Int' is unused}}
then?.bitWidth // expected-error {{cannot use optional chaining on non-optional value of type 'Int'}}
then!.bitWidth // expected-error {{cannot force unwrap value of non-optional type 'Int'}}
// This is tricky because the lexer considers '/^' to be an infix operator.
then /^ then/
// expected-error@-1 {{cannot find operator '/^' in scope}}
// expected-error@-2 {{'/' is not a postfix unary operator}}
self.then(0)
return then
}
func testThenSubscript() {
let then = self
then[0]
}
}
func testOutOfPlace() -> Int {
if .random() {
guard .random() else {
then 0 // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
}
if .random() {
then 0 // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
} else {
then 1 // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
}
then 0 // expected-error {{'then' may only appear as the last statement in an 'if', 'switch', or 'do' expression}}
then 0
} else {
then 1
}
}
func testNested1() -> Int {
if .random() {
if .random() {
then 1
} else {
then 2
}
} else {
switch Bool.random() {
case true:
then 0
case false:
then 1
}
}
}
func testNested2() -> Int {
if .random() {
then if .random() {
then 1
} else {
then 2
}
} else {
then switch Bool.random() {
case true:
then 0
case false:
then 1
}
}
}
func testNested3() -> Int {
if .random() {
print("hello")
then if .random() {
then 1
} else {
then 2
}
} else {
()
()
then switch Bool.random() {
case true:
then 0
case false:
then 1
}
}
}
func throwingFn() throws -> Int { 0 }
func testTryOnThen() throws -> Int {
switch 0 {
case 1:
then try throwingFn() // okay
default:
try then() // expected-warning {{no calls to throwing functions occur within 'try' expression}}
try then{} // expected-warning {{no calls to throwing functions occur within 'try' expression}}
try then {} // expected-warning {{no calls to throwing functions occur within 'try' expression}}
try then throwingFn()
// expected-error@-1 {{'try' must be placed on the produced expression}} {{5-9=}} {{14-14=try }}
}
}
func testReturnTryThen(_ then: Int) -> Int {
return try then // expected-warning {{no calls to throwing functions occur within 'try' expression}}
}
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