Fix output type mismatch with RegexBuilder

Package.swift

@@ -8,6 +8,10 @@ let availabilityDefinition = PackageDescription.SwiftSetting.unsafeFlags([
     "-define-availability",
     "-Xfrontend",
     "SwiftStdlib 5.7:macOS 9999, iOS 9999, watchOS 9999, tvOS 9999",
+    "-Xfrontend",
+    "-define-availability",
+    "-Xfrontend",
+    "SwiftStdlib 5.8:macOS 9999, iOS 9999, watchOS 9999, tvOS 9999",
 ])
 
 /// Swift settings for building a private stdlib-like module that is to be used
@@ -87,7 +91,7 @@ let package = Package(
             name: "RegexBuilderTests",
             dependencies: ["_StringProcessing", "RegexBuilder", "TestSupport"],
             swiftSettings: [
-                .unsafeFlags(["-Xfrontend", "-disable-availability-checking"])
+                availabilityDefinition
             ]),
         .testTarget(
             name: "DocumentationTests",

Sources/RegexBuilder/DSL.swift

@@ -508,3 +508,65 @@ extension Regex.Match {
 internal func makeFactory() -> _RegexFactory {
   _RegexFactory()
 }
+
+/// These are special `accumulate` methods that wrap one or both components in
+/// a node that indicates that that their output types shouldn't be included in
+/// the resulting strongly-typed output type. This is required from a
+/// `buildPartialBlock` call where a component's output type is either ignored
+/// or not included in the resulting type. For example:
+///
+///     static func buildPartialBlock<W0, W1, C1, R0: RegexComponent, R1: RegexComponent>(
+///       accumulated: R0, next: R1
+///     ) -> Regex<(Substring, C1)>  where R0.RegexOutput == W0, R1.RegexOutput == (W1, C1)
+///
+/// In this `buildPartialBlock` overload, `W0` isn't included in the
+/// resulting output type, even though it can match any output type, including
+/// a tuple. When `W0` matches a tuple type that doesn't match another overload
+/// (because of arity or labels) we need this "ignoring" variant so that we
+/// don't have a type mismatch when we ultimately cast the type-erased output
+/// to the expected type.
+@available(SwiftStdlib 5.7, *)
+extension _RegexFactory {
+  /// Concatenates the `left` and `right` component, wrapping `right` to
+  /// indicate that its output type shouldn't be included in the resulting
+  /// strongly-typed output type.
+  @_alwaysEmitIntoClient
+  internal func accumulate<Output>(
+    _ left: some RegexComponent,
+    ignoringOutputTypeOf right: some RegexComponent
+  ) -> Regex<Output> {
+    if #available(macOS 9999, iOS 9999, watchOS 9999, tvOS 9999, *) {
+      return accumulate(left, ignoreCapturesInTypedOutput(right))
+    }
+    return accumulate(left, right)
+  }
+
+  /// Concatenates the `left` and `right` component, wrapping `left` to
+  /// indicate that its output type shouldn't be included in the resulting
+  /// strongly-typed output type.
+  @_alwaysEmitIntoClient
+  internal func accumulate<Output>(
+    ignoringOutputTypeOf left: some RegexComponent,
+    _ right: some RegexComponent
+  ) -> Regex<Output> {
+    if #available(macOS 9999, iOS 9999, watchOS 9999, tvOS 9999, *) {
+      return accumulate(ignoreCapturesInTypedOutput(left), right)
+    }
+    return accumulate(left, right)
+  }
+
+  /// Concatenates the `left` and `right` component, wrapping both sides to
+  /// indicate that their output types shouldn't be included in the resulting
+  /// strongly-typed output type.
+  @_alwaysEmitIntoClient
+  internal func accumulate<Output>(
+    ignoringOutputTypeOf left: some RegexComponent,
+    andAlso right: some RegexComponent
+  ) -> Regex<Output> {
+    if #available(macOS 9999, iOS 9999, watchOS 9999, tvOS 9999, *) {
+      return accumulate(
+        ignoreCapturesInTypedOutput(left), ignoreCapturesInTypedOutput(right))
+    }
+    return accumulate(left, right)
+  }
+}

Sources/RegexBuilder/Variadics.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2021-2022 Apple Inc. and the Swift project authors
+// Copyright (c) 2021-2023 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -20,7 +20,7 @@ extension RegexComponentBuilder {
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C1)>  where R0.RegexOutput == W0, R1.RegexOutput == (W1, C1) {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(ignoringOutputTypeOf: accumulated, next)
   }
 }
 @available(SwiftStdlib 5.7, *)
@@ -30,7 +30,7 @@ extension RegexComponentBuilder {
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C1, C2)>  where R0.RegexOutput == W0, R1.RegexOutput == (W1, C1, C2) {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(ignoringOutputTypeOf: accumulated, next)
   }
 }
 @available(SwiftStdlib 5.7, *)
@@ -40,7 +40,7 @@ extension RegexComponentBuilder {
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C1, C2, C3)>  where R0.RegexOutput == W0, R1.RegexOutput == (W1, C1, C2, C3) {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(ignoringOutputTypeOf: accumulated, next)
   }
 }
 @available(SwiftStdlib 5.7, *)
@@ -50,7 +50,7 @@ extension RegexComponentBuilder {
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C1, C2, C3, C4)>  where R0.RegexOutput == W0, R1.RegexOutput == (W1, C1, C2, C3, C4) {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(ignoringOutputTypeOf: accumulated, next)
   }
 }
 @available(SwiftStdlib 5.7, *)
@@ -60,7 +60,7 @@ extension RegexComponentBuilder {
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C1, C2, C3, C4, C5)>  where R0.RegexOutput == W0, R1.RegexOutput == (W1, C1, C2, C3, C4, C5) {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(ignoringOutputTypeOf: accumulated, next)
   }
 }
 @available(SwiftStdlib 5.7, *)
@@ -70,7 +70,7 @@ extension RegexComponentBuilder {
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C1, C2, C3, C4, C5, C6)>  where R0.RegexOutput == W0, R1.RegexOutput == (W1, C1, C2, C3, C4, C5, C6) {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(ignoringOutputTypeOf: accumulated, next)
   }
 }
 @available(SwiftStdlib 5.7, *)
@@ -80,7 +80,7 @@ extension RegexComponentBuilder {
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C1, C2, C3, C4, C5, C6, C7)>  where R0.RegexOutput == W0, R1.RegexOutput == (W1, C1, C2, C3, C4, C5, C6, C7) {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(ignoringOutputTypeOf: accumulated, next)
   }
 }
 @available(SwiftStdlib 5.7, *)
@@ -90,7 +90,7 @@ extension RegexComponentBuilder {
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C1, C2, C3, C4, C5, C6, C7, C8)>  where R0.RegexOutput == W0, R1.RegexOutput == (W1, C1, C2, C3, C4, C5, C6, C7, C8) {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(ignoringOutputTypeOf: accumulated, next)
   }
 }
 @available(SwiftStdlib 5.7, *)
@@ -100,7 +100,7 @@ extension RegexComponentBuilder {
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C1, C2, C3, C4, C5, C6, C7, C8, C9)>  where R0.RegexOutput == W0, R1.RegexOutput == (W1, C1, C2, C3, C4, C5, C6, C7, C8, C9) {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(ignoringOutputTypeOf: accumulated, next)
   }
 }
 @available(SwiftStdlib 5.7, *)
@@ -110,7 +110,7 @@ extension RegexComponentBuilder {
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C1, C2, C3, C4, C5, C6, C7, C8, C9, C10)>  where R0.RegexOutput == W0, R1.RegexOutput == (W1, C1, C2, C3, C4, C5, C6, C7, C8, C9, C10) {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(ignoringOutputTypeOf: accumulated, next)
   }
 }
 @available(SwiftStdlib 5.7, *)
@@ -565,123 +565,112 @@ extension RegexComponentBuilder {
 }
 @available(SwiftStdlib 5.7, *)
 extension RegexComponentBuilder {
-  @available(SwiftStdlib 5.7, *)
   @_alwaysEmitIntoClient
   public static func buildPartialBlock<W0, R0: RegexComponent, R1: RegexComponent>(
     accumulated: R0, next: R1
   ) -> Regex<Substring> where R0.RegexOutput == W0  {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(ignoringOutputTypeOf: accumulated, andAlso: next)
   }
 }
 @available(SwiftStdlib 5.7, *)
 extension RegexComponentBuilder {
-  @available(SwiftStdlib 5.7, *)
   @_alwaysEmitIntoClient
   public static func buildPartialBlock<W0, C0, R0: RegexComponent, R1: RegexComponent>(
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C0)> where R0.RegexOutput == (W0, C0)  {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(accumulated, ignoringOutputTypeOf: next)
   }
 }
 @available(SwiftStdlib 5.7, *)
 extension RegexComponentBuilder {
-  @available(SwiftStdlib 5.7, *)
   @_alwaysEmitIntoClient
   public static func buildPartialBlock<W0, C0, C1, R0: RegexComponent, R1: RegexComponent>(
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C0, C1)> where R0.RegexOutput == (W0, C0, C1)  {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(accumulated, ignoringOutputTypeOf: next)
   }
 }
 @available(SwiftStdlib 5.7, *)
 extension RegexComponentBuilder {
-  @available(SwiftStdlib 5.7, *)
   @_alwaysEmitIntoClient
   public static func buildPartialBlock<W0, C0, C1, C2, R0: RegexComponent, R1: RegexComponent>(
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C0, C1, C2)> where R0.RegexOutput == (W0, C0, C1, C2)  {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(accumulated, ignoringOutputTypeOf: next)
   }
 }
 @available(SwiftStdlib 5.7, *)
 extension RegexComponentBuilder {
-  @available(SwiftStdlib 5.7, *)
   @_alwaysEmitIntoClient
   public static func buildPartialBlock<W0, C0, C1, C2, C3, R0: RegexComponent, R1: RegexComponent>(
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C0, C1, C2, C3)> where R0.RegexOutput == (W0, C0, C1, C2, C3)  {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(accumulated, ignoringOutputTypeOf: next)
   }
 }
 @available(SwiftStdlib 5.7, *)
 extension RegexComponentBuilder {
-  @available(SwiftStdlib 5.7, *)
   @_alwaysEmitIntoClient
   public static func buildPartialBlock<W0, C0, C1, C2, C3, C4, R0: RegexComponent, R1: RegexComponent>(
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C0, C1, C2, C3, C4)> where R0.RegexOutput == (W0, C0, C1, C2, C3, C4)  {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(accumulated, ignoringOutputTypeOf: next)
   }
 }
 @available(SwiftStdlib 5.7, *)
 extension RegexComponentBuilder {
-  @available(SwiftStdlib 5.7, *)
   @_alwaysEmitIntoClient
   public static func buildPartialBlock<W0, C0, C1, C2, C3, C4, C5, R0: RegexComponent, R1: RegexComponent>(
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C0, C1, C2, C3, C4, C5)> where R0.RegexOutput == (W0, C0, C1, C2, C3, C4, C5)  {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(accumulated, ignoringOutputTypeOf: next)
   }
 }
 @available(SwiftStdlib 5.7, *)
 extension RegexComponentBuilder {
-  @available(SwiftStdlib 5.7, *)
   @_alwaysEmitIntoClient
   public static func buildPartialBlock<W0, C0, C1, C2, C3, C4, C5, C6, R0: RegexComponent, R1: RegexComponent>(
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C0, C1, C2, C3, C4, C5, C6)> where R0.RegexOutput == (W0, C0, C1, C2, C3, C4, C5, C6)  {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(accumulated, ignoringOutputTypeOf: next)
   }
 }
 @available(SwiftStdlib 5.7, *)
 extension RegexComponentBuilder {
-  @available(SwiftStdlib 5.7, *)
   @_alwaysEmitIntoClient
   public static func buildPartialBlock<W0, C0, C1, C2, C3, C4, C5, C6, C7, R0: RegexComponent, R1: RegexComponent>(
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C0, C1, C2, C3, C4, C5, C6, C7)> where R0.RegexOutput == (W0, C0, C1, C2, C3, C4, C5, C6, C7)  {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(accumulated, ignoringOutputTypeOf: next)
   }
 }
 @available(SwiftStdlib 5.7, *)
 extension RegexComponentBuilder {
-  @available(SwiftStdlib 5.7, *)
   @_alwaysEmitIntoClient
   public static func buildPartialBlock<W0, C0, C1, C2, C3, C4, C5, C6, C7, C8, R0: RegexComponent, R1: RegexComponent>(
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C0, C1, C2, C3, C4, C5, C6, C7, C8)> where R0.RegexOutput == (W0, C0, C1, C2, C3, C4, C5, C6, C7, C8)  {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(accumulated, ignoringOutputTypeOf: next)
   }
 }
 @available(SwiftStdlib 5.7, *)
 extension RegexComponentBuilder {
-  @available(SwiftStdlib 5.7, *)
   @_alwaysEmitIntoClient
   public static func buildPartialBlock<W0, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, R0: RegexComponent, R1: RegexComponent>(
     accumulated: R0, next: R1
   ) -> Regex<(Substring, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9)> where R0.RegexOutput == (W0, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9)  {
     let factory = makeFactory()
-    return factory.accumulate(accumulated, next)
+    return factory.accumulate(accumulated, ignoringOutputTypeOf: next)
   }
 }
 
@@ -6884,7 +6873,3 @@ extension TryCapture {
     self.init(factory.captureOptional(componentBuilder(), reference._raw, transform))
   }
 }
-
-
-
-// END AUTO-GENERATED CONTENT

Sources/VariadicsGenerator/VariadicsGenerator.swift

@@ -132,7 +132,7 @@ struct VariadicsGenerator: ParsableCommand {
       //
       // This source file is part of the Swift.org open source project
       //
-      // Copyright (c) 2021-2022 Apple Inc. and the Swift project authors
+      // Copyright (c) 2021-2023 Apple Inc. and the Swift project authors
       // Licensed under Apache License v2.0 with Runtime Library Exception
       //
       // See https://swift.org/LICENSE.txt for license information
@@ -262,7 +262,20 @@ struct VariadicsGenerator: ParsableCommand {
           accumulated: R0, next: R1
         ) -> \(regexTypeName)<\(matchType)> \(whereClause) {
           let factory = makeFactory()
+
+      """)
+    if leftArity == 0 {
+      output("""
+          return factory.accumulate(ignoringOutputTypeOf: accumulated, next)
+
+      """)
+    } else {
+      output("""
           return factory.accumulate(accumulated, next)
+
+      """)
+    }
+    output("""
         }
       }
 
@@ -274,7 +287,6 @@ struct VariadicsGenerator: ParsableCommand {
     output("""
       \(defaultAvailableAttr)
       extension \(concatBuilderName) {
-        \(defaultAvailableAttr)
         @_alwaysEmitIntoClient
         public static func buildPartialBlock<W0
       """)
@@ -308,7 +320,20 @@ struct VariadicsGenerator: ParsableCommand {
     output("""
         {
           let factory = makeFactory()
-          return factory.accumulate(accumulated, next)
+
+      """)
+    if leftArity == 0 {
+      output("""
+          return factory.accumulate(ignoringOutputTypeOf: accumulated, andAlso: next)
+
+      """)
+    } else {
+      output("""
+          return factory.accumulate(accumulated, ignoringOutputTypeOf: next)
+
+      """)
+    }
+    output("""
         }
       }