Add editor place holder type

Author: kimdv

CodeGeneration/Sources/SyntaxSupport/SyntaxNodeKind.swift

@@ -112,6 +112,7 @@ public enum SyntaxNodeKind: String, CaseIterable {
   case editorPlaceholderDecl
   case editorPlaceholderExpr
   case editorPlaceholderPattern
+  case editorPlaceholderType
   case effectsAttributeArgumentList
   case enumCaseDecl
   case enumCaseElement

CodeGeneration/Sources/SyntaxSupport/TypeNodes.swift

@@ -530,4 +530,28 @@ public let TYPE_NODES: [Node] = [
     ]
   ),
 
+  Node(
+    kind: .editorPlaceholderType,
+    base: .type,
+    nameForDiagnostics: "editor placeholder",
+    documentation: """
+      An editor placeholder, e.g. `<#Type#>` that is used in a position that expects a type.
+      """,
+    children: [
+      Child(
+        name: "placeholder",
+        kind: .token(choices: [.token(.identifier)]),
+        documentation: """
+          The actual editor placeholder that starts with `<#` and ends with `#>`.
+          """
+      ),
+      Child(
+        name: "genericArgumentClause",
+        kind: .node(kind: .genericArgumentClause),
+        documentation: "Generic arguments that is attatched to the type.",
+        isOptional: true
+      ),
+    ]
+  ),
+
 ]

Release Notes/510.md

@@ -26,6 +26,11 @@
   - Issue: https://github.com/apple/swift-syntax/issues/2147
   - Pull Request: https://github.com/apple/swift-syntax/pull/2150
 
+- New type node `EditorPlaceholderTypeSyntax`
+  - Description: This node type will be placeholder that is used in a position that expects a type.
+  - Issue: https://github.com/apple/swift-syntax/issues/2156
+  - Pull Request: https://github.com/apple/swift-syntax/pull/2150
+
 ## API Behavior Changes
 
 ## Deprecations

Sources/SwiftParser/Types.swift

@@ -349,14 +349,25 @@ extension Parser {
       generics = nil
     }
 
-    return RawTypeSyntax(
-      RawIdentifierTypeSyntax(
-        unexpectedBeforeName,
-        name: name,
-        genericArgumentClause: generics,
-        arena: self.arena
+    if name.tokenText.isEditorPlaceholder {
+      return RawTypeSyntax(
+        RawEditorPlaceholderTypeSyntax(
+          placeholder: name,
+          genericArgumentClause: generics,
+          arena: self.arena
+        )
       )
-    )
+    } else {
+      return RawTypeSyntax(
+        RawIdentifierTypeSyntax(
+          unexpectedBeforeName,
+          name: name,
+          genericArgumentClause: generics,
+          arena: self.arena
+        )
+      )
+    }
+
   }
 
   /// Parse the existential `Any` type.
@@ -938,7 +949,9 @@ extension Parser {
 
 extension Parser {
   mutating func parseResultType() -> RawTypeSyntax {
-    if self.at(prefix: "<") {
+    if self.at(prefix: "<#") {
+      return self.parseTypeIdentifier()
+    } else if self.at(prefix: "<") {
       let generics = self.parseGenericParameters()
       let baseType = self.parseType()
       return RawTypeSyntax(

Sources/SwiftParserDiagnostics/generated/SyntaxKindNameForDiagnostics.swift

@@ -145,6 +145,8 @@ extension SyntaxKind {
       return "editor placeholder"
     case .editorPlaceholderPattern:
       return "editor placeholder"
+    case .editorPlaceholderType:
+      return "editor placeholder"
     case .effectsAttributeArgumentList:
       return "@_effects arguments"
     case .enumCaseDecl:

Sources/SwiftSyntax/Documentation.docc/generated/SwiftSyntax.md

@@ -191,6 +191,7 @@ These articles are intended for developers wishing to contribute to SwiftSyntax
 - <doc:SwiftSyntax/ClassRestrictionTypeSyntax>
 - <doc:SwiftSyntax/CompositionTypeSyntax>
 - <doc:SwiftSyntax/DictionaryTypeSyntax>
+- <doc:SwiftSyntax/EditorPlaceholderTypeSyntax>
 - <doc:SwiftSyntax/FunctionTypeSyntax>
 - <doc:SwiftSyntax/IdentifierTypeSyntax>
 - <doc:SwiftSyntax/ImplicitlyUnwrappedOptionalTypeSyntax>

Sources/SwiftSyntax/generated/ChildNameForKeyPath.swift

@@ -1083,6 +1083,16 @@ public func childName(_ keyPath: AnyKeyPath) -> String? {
     return "placeholder"
   case \EditorPlaceholderPatternSyntax.unexpectedAfterPlaceholder:
     return "unexpectedAfterPlaceholder"
+  case \EditorPlaceholderTypeSyntax.unexpectedBeforePlaceholder:
+    return "unexpectedBeforePlaceholder"
+  case \EditorPlaceholderTypeSyntax.placeholder:
+    return "placeholder"
+  case \EditorPlaceholderTypeSyntax.unexpectedBetweenPlaceholderAndGenericArgumentClause:
+    return "unexpectedBetweenPlaceholderAndGenericArgumentClause"
+  case \EditorPlaceholderTypeSyntax.genericArgumentClause:
+    return "genericArgumentClause"
+  case \EditorPlaceholderTypeSyntax.unexpectedAfterGenericArgumentClause:
+    return "unexpectedAfterGenericArgumentClause"
   case \EnumCaseDeclSyntax.unexpectedBeforeAttributes:
     return "unexpectedBeforeAttributes"
   case \EnumCaseDeclSyntax.attributes:

Sources/SwiftSyntax/generated/SyntaxAnyVisitor.swift

@@ -784,6 +784,14 @@ open class SyntaxAnyVisitor: SyntaxVisitor {
     visitAnyPost(node._syntaxNode)
   }
 
+  override open func visit(_ node: EditorPlaceholderTypeSyntax) -> SyntaxVisitorContinueKind {
+    return visitAny(node._syntaxNode)
+  }
+  
+  override open func visitPost(_ node: EditorPlaceholderTypeSyntax) {
+    visitAnyPost(node._syntaxNode)
+  }
+  
   override open func visit(_ node: EffectsAttributeArgumentListSyntax) -> SyntaxVisitorContinueKind {
     return visitAny(node._syntaxNode)
   }

Sources/SwiftSyntax/generated/SyntaxBaseNodes.swift

@@ -1299,7 +1299,7 @@ public struct TypeSyntax: TypeSyntaxProtocol, SyntaxHashable {
 
   public init?(_ node: some SyntaxProtocol) {
     switch node.raw.kind {
-    case .arrayType, .attributedType, .classRestrictionType, .compositionType, .dictionaryType, .functionType, .identifierType, .implicitlyUnwrappedOptionalType, .memberType, .metatypeType, .missingType, .namedOpaqueReturnType, .optionalType, .packElementType, .packExpansionType, .someOrAnyType, .suppressedType, .tupleType:
+    case .arrayType, .attributedType, .classRestrictionType, .compositionType, .dictionaryType, .editorPlaceholderType, .functionType, .identifierType, .implicitlyUnwrappedOptionalType, .memberType, .metatypeType, .missingType, .namedOpaqueReturnType, .optionalType, .packElementType, .packExpansionType, .someOrAnyType, .suppressedType, .tupleType:
       self._syntaxNode = node._syntaxNode
     default:
       return nil
@@ -1329,6 +1329,7 @@ public struct TypeSyntax: TypeSyntaxProtocol, SyntaxHashable {
           .node(ClassRestrictionTypeSyntax.self),
           .node(CompositionTypeSyntax.self),
           .node(DictionaryTypeSyntax.self),
+          .node(EditorPlaceholderTypeSyntax.self),
           .node(FunctionTypeSyntax.self),
           .node(IdentifierTypeSyntax.self),
           .node(ImplicitlyUnwrappedOptionalTypeSyntax.self),
@@ -1488,6 +1489,7 @@ extension Syntax {
           .node(EditorPlaceholderDeclSyntax.self),
           .node(EditorPlaceholderExprSyntax.self),
           .node(EditorPlaceholderPatternSyntax.self),
+          .node(EditorPlaceholderTypeSyntax.self),
           .node(EffectsAttributeArgumentListSyntax.self),
           .node(EnumCaseDeclSyntax.self),
           .node(EnumCaseElementListSyntax.self),

Sources/SwiftSyntax/generated/SyntaxEnum.swift

@@ -106,6 +106,7 @@ public enum SyntaxEnum {
   case editorPlaceholderDecl(EditorPlaceholderDeclSyntax)
   case editorPlaceholderExpr(EditorPlaceholderExprSyntax)
   case editorPlaceholderPattern(EditorPlaceholderPatternSyntax)
+  case editorPlaceholderType(EditorPlaceholderTypeSyntax)
   case effectsAttributeArgumentList(EffectsAttributeArgumentListSyntax)
   case enumCaseDecl(EnumCaseDeclSyntax)
   case enumCaseElementList(EnumCaseElementListSyntax)
@@ -482,6 +483,8 @@ public extension Syntax {
       return .editorPlaceholderExpr(EditorPlaceholderExprSyntax(self)!)
     case .editorPlaceholderPattern:
       return .editorPlaceholderPattern(EditorPlaceholderPatternSyntax(self)!)
+    case .editorPlaceholderType:
+      return .editorPlaceholderType(EditorPlaceholderTypeSyntax(self)!)
     case .effectsAttributeArgumentList:
       return .effectsAttributeArgumentList(EffectsAttributeArgumentListSyntax(self)!)
     case .enumCaseDecl:

Sources/SwiftSyntax/generated/SyntaxKind.swift

@@ -106,6 +106,7 @@ public enum SyntaxKind: CaseIterable {
   case editorPlaceholderDecl
   case editorPlaceholderExpr
   case editorPlaceholderPattern
+  case editorPlaceholderType
   case effectsAttributeArgumentList
   case enumCaseDecl
   case enumCaseElementList
@@ -603,6 +604,8 @@ public enum SyntaxKind: CaseIterable {
       return EditorPlaceholderExprSyntax.self
     case .editorPlaceholderPattern:
       return EditorPlaceholderPatternSyntax.self
+    case .editorPlaceholderType:
+      return EditorPlaceholderTypeSyntax.self
     case .effectsAttributeArgumentList:
       return EffectsAttributeArgumentListSyntax.self
     case .enumCaseDecl:

Sources/SwiftSyntax/generated/SyntaxRewriter.swift

@@ -717,6 +717,13 @@ open class SyntaxRewriter {
     return PatternSyntax(visitChildren(node))
   }
 
+  /// Visit a ``EditorPlaceholderTypeSyntax``.
+  ///   - Parameter node: the node that is being visited
+  ///   - Returns: the rewritten node
+  open func visit(_ node: EditorPlaceholderTypeSyntax) -> TypeSyntax {
+    return TypeSyntax(visitChildren(node))
+  }
+  
   /// Visit a ``EffectsAttributeArgumentListSyntax``.
   ///   - Parameter node: the node that is being visited
   ///   - Returns: the rewritten node
@@ -2467,6 +2474,10 @@ open class SyntaxRewriter {
       return {
         self.visitImpl($0, EditorPlaceholderPatternSyntax.self, self.visit)
       }
+    case .editorPlaceholderType:
+      return {
+        self.visitImpl($0, EditorPlaceholderTypeSyntax.self, self.visit)
+      }
     case .effectsAttributeArgumentList:
       return {
         self.visitImpl($0, EffectsAttributeArgumentListSyntax.self, self.visit)
@@ -3403,6 +3414,8 @@ open class SyntaxRewriter {
       return visitImpl(node, EditorPlaceholderExprSyntax.self, visit)
     case .editorPlaceholderPattern:
       return visitImpl(node, EditorPlaceholderPatternSyntax.self, visit)
+    case .editorPlaceholderType:
+      return visitImpl(node, EditorPlaceholderTypeSyntax.self, visit)
     case .effectsAttributeArgumentList:
       return visitImpl(node, EffectsAttributeArgumentListSyntax.self, visit)
     case .enumCaseDecl:

Sources/SwiftSyntax/generated/SyntaxTransform.swift

@@ -475,6 +475,11 @@ public protocol SyntaxTransformVisitor {
   ///   - Returns: the sum of whatever the child visitors return.
   func visit(_ node: EditorPlaceholderPatternSyntax) -> ResultType
 
+  /// Visiting ``EditorPlaceholderTypeSyntax`` specifically.
+  ///   - Parameter node: the node we are visiting.
+  ///   - Returns: the sum of whatever the child visitors return.
+  func visit(_ node: EditorPlaceholderTypeSyntax) -> ResultType
+  
   /// Visiting ``EffectsAttributeArgumentListSyntax`` specifically.
   ///   - Parameter node: the node we are visiting.
   ///   - Returns: the sum of whatever the child visitors return.
@@ -2048,6 +2053,13 @@ extension SyntaxTransformVisitor {
     visitAny(Syntax(node))
   }
 
+  /// Visiting ``EditorPlaceholderTypeSyntax`` specifically.
+  ///   - Parameter node: the node we are visiting.
+  ///   - Returns: nil by default.
+  public func visit(_ node: EditorPlaceholderTypeSyntax) -> ResultType {
+    visitAny(Syntax(node))
+  }
+  
   /// Visiting ``EffectsAttributeArgumentListSyntax`` specifically.
   ///   - Parameter node: the node we are visiting.
   ///   - Returns: nil by default.
@@ -3536,6 +3548,8 @@ extension SyntaxTransformVisitor {
       return visit(derived)
     case .editorPlaceholderPattern(let derived):
       return visit(derived)
+    case .editorPlaceholderType(let derived):
+      return visit(derived)
     case .effectsAttributeArgumentList(let derived):
       return visit(derived)
     case .enumCaseDecl(let derived):

Sources/SwiftSyntax/generated/SyntaxVisitor.swift

@@ -1126,6 +1126,18 @@ open class SyntaxVisitor {
   open func visitPost(_ node: EditorPlaceholderPatternSyntax) {
   }
 
+  /// Visiting ``EditorPlaceholderTypeSyntax`` specifically.
+  ///   - Parameter node: the node we are visiting.
+  ///   - Returns: how should we continue visiting.
+  open func visit(_ node: EditorPlaceholderTypeSyntax) -> SyntaxVisitorContinueKind {
+    return .visitChildren
+  }
+  
+  /// The function called after visiting ``EditorPlaceholderTypeSyntax`` and its descendants.
+  ///   - node: the node we just finished visiting.
+  open func visitPost(_ node: EditorPlaceholderTypeSyntax) {
+  }
+  
   /// Visiting ``EffectsAttributeArgumentListSyntax`` specifically.
   ///   - Parameter node: the node we are visiting.
   ///   - Returns: how should we continue visiting.
@@ -3784,6 +3796,10 @@ open class SyntaxVisitor {
       return {
         self.visitImpl($0, EditorPlaceholderPatternSyntax.self, self.visit, self.visitPost)
       }
+    case .editorPlaceholderType:
+      return {
+        self.visitImpl($0, EditorPlaceholderTypeSyntax.self, self.visit, self.visitPost)
+      }
     case .effectsAttributeArgumentList:
       return {
         self.visitImpl($0, EffectsAttributeArgumentListSyntax.self, self.visit, self.visitPost)
@@ -4723,6 +4739,8 @@ open class SyntaxVisitor {
       visitImpl(node, EditorPlaceholderExprSyntax.self, visit, visitPost)
     case .editorPlaceholderPattern:
       visitImpl(node, EditorPlaceholderPatternSyntax.self, visit, visitPost)
+    case .editorPlaceholderType:
+      visitImpl(node, EditorPlaceholderTypeSyntax.self, visit, visitPost)
     case .effectsAttributeArgumentList:
       visitImpl(node, EffectsAttributeArgumentListSyntax.self, visit, visitPost)
     case .enumCaseDecl:

Sources/SwiftSyntax/generated/raw/RawSyntaxNodesEF.swift

@@ -199,6 +199,76 @@ public struct RawEditorPlaceholderPatternSyntax: RawPatternSyntaxNodeProtocol {
   }
 }
 
+@_spi(RawSyntax)
+public struct RawEditorPlaceholderTypeSyntax: RawTypeSyntaxNodeProtocol {
+  @_spi(RawSyntax)
+  public var layoutView: RawSyntaxLayoutView {
+    return raw.layoutView!
+  }
+  
+  public static func isKindOf(_ raw: RawSyntax) -> Bool {
+    return raw.kind == .editorPlaceholderType
+  }
+  
+  public var raw: RawSyntax
+  
+  init(raw: RawSyntax) {
+    precondition(Self.isKindOf(raw))
+    self.raw = raw
+  }
+  
+  private init(unchecked raw: RawSyntax) {
+    self.raw = raw
+  }
+  
+  public init?(_ other: some RawSyntaxNodeProtocol) {
+    guard Self.isKindOf(other.raw) else {
+      return nil
+    }
+    self.init(unchecked: other.raw)
+  }
+  
+  public init(
+      _ unexpectedBeforePlaceholder: RawUnexpectedNodesSyntax? = nil, 
+      placeholder: RawTokenSyntax, 
+      _ unexpectedBetweenPlaceholderAndGenericArgumentClause: RawUnexpectedNodesSyntax? = nil, 
+      genericArgumentClause: RawGenericArgumentClauseSyntax?, 
+      _ unexpectedAfterGenericArgumentClause: RawUnexpectedNodesSyntax? = nil, 
+      arena: __shared SyntaxArena
+    ) {
+    let raw = RawSyntax.makeLayout(
+      kind: .editorPlaceholderType, uninitializedCount: 5, arena: arena) { layout in
+      layout.initialize(repeating: nil)
+      layout[0] = unexpectedBeforePlaceholder?.raw
+      layout[1] = placeholder.raw
+      layout[2] = unexpectedBetweenPlaceholderAndGenericArgumentClause?.raw
+      layout[3] = genericArgumentClause?.raw
+      layout[4] = unexpectedAfterGenericArgumentClause?.raw
+    }
+    self.init(unchecked: raw)
+  }
+  
+  public var unexpectedBeforePlaceholder: RawUnexpectedNodesSyntax? {
+    layoutView.children[0].map(RawUnexpectedNodesSyntax.init(raw:))
+  }
+  
+  public var placeholder: RawTokenSyntax {
+    layoutView.children[1].map(RawTokenSyntax.init(raw:))!
+  }
+  
+  public var unexpectedBetweenPlaceholderAndGenericArgumentClause: RawUnexpectedNodesSyntax? {
+    layoutView.children[2].map(RawUnexpectedNodesSyntax.init(raw:))
+  }
+  
+  public var genericArgumentClause: RawGenericArgumentClauseSyntax? {
+    layoutView.children[3].map(RawGenericArgumentClauseSyntax.init(raw:))
+  }
+  
+  public var unexpectedAfterGenericArgumentClause: RawUnexpectedNodesSyntax? {
+    layoutView.children[4].map(RawUnexpectedNodesSyntax.init(raw:))
+  }
+}
+
 @_spi(RawSyntax)
 public struct RawEffectsAttributeArgumentListSyntax: RawSyntaxNodeProtocol {
   @_spi(RawSyntax)

Sources/SwiftSyntax/generated/raw/RawSyntaxNodesTUVWXYZ.swift

@@ -1306,7 +1306,7 @@ public struct RawTypeSyntax: RawTypeSyntaxNodeProtocol {
 
   public static func isKindOf(_ raw: RawSyntax) -> Bool {
     switch raw.kind {
-    case .arrayType, .attributedType, .classRestrictionType, .compositionType, .dictionaryType, .functionType, .identifierType, .implicitlyUnwrappedOptionalType, .memberType, .metatypeType, .missingType, .namedOpaqueReturnType, .optionalType, .packElementType, .packExpansionType, .someOrAnyType, .suppressedType, .tupleType:
+    case .arrayType, .attributedType, .classRestrictionType, .compositionType, .dictionaryType, .editorPlaceholderType, .functionType, .identifierType, .implicitlyUnwrappedOptionalType, .memberType, .metatypeType, .missingType, .namedOpaqueReturnType, .optionalType, .packElementType, .packExpansionType, .someOrAnyType, .suppressedType, .tupleType:
       return true
     default:
       return false