Move back to single quoted syntax

Author: John Holdsworth

lib/Parse/Lexer.cpp

@@ -1911,7 +1911,8 @@ void Lexer::lexStringLiteral(unsigned CustomDelimiterLen) {
     wasErroneous |= CharValue == ~1U;
   }
 
-  if (QuoteChar == '\'') {
+  if (QuoteChar == '\'' && !(CurPtr - TokStart == 3 &&
+         !IsMultilineString && CustomDelimiterLen == 0 )) {
     assert(!IsMultilineString && CustomDelimiterLen == 0 &&
            "Single quoted string cannot have custom delimiter, nor multiline");
     diagnoseSingleQuoteStringLiteral(TokStart, CurPtr);

lib/Parse/ParseDecl.cpp

@@ -235,7 +235,7 @@ void Parser::parseTopLevelItems(SmallVectorImpl<ASTNode> &items) {
     }
   }
 
-#if SWIFT_BUILD_SWIFT_SYNTAX
+#if SWIFT_BUILD_SWIFT_SYNTAX && 0
   if (existingParsingTransaction)
     existingParsingTransaction->abort();
 

lib/Sema/TypeChecker.cpp

@@ -103,7 +103,8 @@ ProtocolDecl *TypeChecker::getLiteralProtocol(ASTContext &Context, Expr *expr) {
   if (const auto *SLE = dyn_cast<StringLiteralExpr>(expr)) {
     if (SLE->isSingleUnicodeScalar())
       return TypeChecker::getProtocol(
-          Context, expr->getLoc(), SLE->getValue().size() == 1 ?
+          Context, expr->getLoc(), SLE->getValue().size() == 1 &&
+                              SLE->getValue().data()[-1] == '\'' ?
           KnownProtocolKind::ExpressibleByASCIIScalarLiteral :
           KnownProtocolKind::ExpressibleByUnicodeScalarLiteral);
 

test/Constraints/patterns.swift

@@ -631,7 +631,9 @@ func testExprPatternIsolation() {
   }
   for case 0 in nil {} // expected-error {{'nil' requires a contextual type}}
   for case 0 in [nil] {}
-  // expected-error@-1 {{expression pattern of type 'Int' cannot match values of type 'Any?'}}
+  // expected-error@-1 {{type 'Any' cannot conform to 'Equatable'}}
+  // expected-note@-2 {{only concrete types such as structs, enums and classes can conform to protocols}}
+  // expected-note@-3 {{requirement from conditional conformance of 'Any?' to 'Equatable'}}
 
   // Though we will try Double for an integer literal...
   let d: Double = 0
@@ -677,7 +679,7 @@ func testExprPatternIsolation() {
 
   // FIXME: Bad error (https://github.com/apple/swift/issues/64279)
   if case .e(nil, 0) = produceMultiPayload() {}
-  // expected-error@-1 {{expression pattern of type 'Unicode.Scalar' cannot match values of type 'UInt8'}}
+  // expected-error@-1 {{expression pattern of type 'String' cannot match values of type 'Substring'}}
   // expected-note@-2 {{overloads for '~=' exist with these partially matching parameter lists}}
 
   if case .e(5, nil) = produceMultiPayload() as MultiPayload<Int?> {}

test/Constraints/rdar105782480.swift

@@ -11,8 +11,8 @@ func foo(value: MyEnum) {
   takeClosure {
     switch value {
     case .second(let drag).invalid:
-      // expected-error@-1 {{expression pattern of type 'Unicode.Scalar' cannot match values of type 'MyEnum'}}
-      // expected-error@-2 {{type 'Unicode.Scalar' has no member 'second'}}
+      // expected-error@-1 {{value of type 'MyEnum' has no member 'invalid'}}
+      // expected-error@-2 {{'let' binding pattern cannot appear in an expression}}
       break
     }
   }

test/Misc/character_ops.swift

@@ -4,20 +4,20 @@
 let c = UInt8(ascii: "a")
 
 // CHECK: OK
-if c == "a" {
+if c == 'a' {
   print("OK")
 }
 
 // CHECK: OK
-if c != "b" {
+if c != 'b' {
   print("OK")
 }
 
 // CHECK: OK
 switch c {
-case "a":
+case 'a':
   print("OK")
-case "b":
+case 'b':
   fallthrough
 default:
   print("FAIL")
@@ -26,27 +26,27 @@ default:
 let d: UInt8? = UInt8(ascii: "a")
 
 // CHECK: OK
-if d == "a" {
+if d == 'a' {
   print("OK")
 }
 
 // CHECK: OK
-if d != "b" {
+if d != 'b' {
   print("OK")
 }
 
 // CHECK: OK
 switch d {
-case "a":
+case 'a':
   print("OK")
-case "b":
+case 'b':
   fallthrough
 default:
   print("FAIL")
 }
 
 // CHECK: OK
-if UInt8(unicode: "a") == "a" {
+if UInt8(unicode: "a") == 'a' {
   print("OK")
 }
 

test/Parse/new_parser_diagnostics.swift

@@ -4,5 +4,7 @@
 // RUN: %target-typecheck-verify-swift -enable-experimental-feature ParserDiagnostics
 
 _ = [(Int) -> async throws Int]()
-// expected-error@-1{{'async throws' must precede '->'}}
-// expected-note@-2{{move 'async throws' in front of '->'}}{{15-21=}} {{21-28=}} {{20-21= }} {{12-12=async }} {{12-12=throws }}
+// expected-error@-1{{'async' may only occur before '->'}}
+// expected-error@-2{{'async throws' must precede '->'}}
+// expected-error@-3{{'throws' may only occur before '->'}}{{21-28=}} {{12-12=throws }}
+// expected-note@-4{{move 'async throws' in front of '->'}}

test/expr/expressions.swift

@@ -516,7 +516,6 @@ func testSingleQuoteStringLiterals() {
   _ = "abc\('def')" // expected-error{{single-quoted string literal found, use '"'}}{{13-18="def"}}
   _ = 'ab\("c")' // expected-error{{single-quoted string literal found, use '"'}}{{7-17="ab\\("c")"}}
   _ = 'a\('b')c' // expected-error{{single-quoted string literal found, use '"'}}{{7-17="a\\('b')c"}}
-                 // expected-error@-1{{single-quoted string literal found, use '"'}}{{11-14="b"}}
 
   _ = "abc' // expected-error{{unterminated string literal}}
   _ = 'abc" // expected-error{{unterminated string literal}}

test/stdlib/UnicodeScalarDiagnostics.swift

@@ -9,9 +9,9 @@ func test_UnicodeScalarDoesNotImplementArithmetic(_ us: UnicodeScalar, i: Int) {
   var a1 = "a" + "b" // OK
   isString(&a1)
   // We don't check for the overload choices list on the overload note match because they may change on different platforms. 
-  let a2 = "a" - "b"
-  let a3 = "a" * "b"
-  let a4 = "a" / "b"
+  let a2 = "a" - "b" // expected-error {{binary operator '-' cannot be applied to two 'String' operands}}
+  let a3 = "a" * "b" // expected-error {{binary operator '*' cannot be applied to two 'String' operands}}
+  let a4 = "a" / "b" // expected-error {{binary operator '/' cannot be applied to two 'String' operands}}
 
   let b1 = us + us // expected-error {{binary operator '+' cannot be applied to two 'UnicodeScalar' (aka 'Unicode.Scalar') operands}}
   let b2 = us - us // expected-error {{binary operator '-' cannot be applied to two 'UnicodeScalar' (aka 'Unicode.Scalar') operands}}