Merge pull request #2950 from amritpan/method-keypaths

Author: amritpan

CodeGeneration/Sources/SyntaxSupport/ExperimentalFeatures.swift

@@ -21,6 +21,7 @@ public enum ExperimentalFeature: String, CaseIterable {
   case coroutineAccessors
   case valueGenerics
   case abiAttribute
+  case keypathWithMethodMembers
 
   /// The name of the feature as it is written in the compiler's `Features.def` file.
   public var featureName: String {
@@ -41,6 +42,8 @@ public enum ExperimentalFeature: String, CaseIterable {
       return "ValueGenerics"
     case .abiAttribute:
       return "ABIAttribute"
+    case .keypathWithMethodMembers:
+      return "KeypathWithMethodMembers"
     }
   }
 
@@ -63,6 +66,8 @@ public enum ExperimentalFeature: String, CaseIterable {
       return "value generics"
     case .abiAttribute:
       return "@abi attribute"
+    case .keypathWithMethodMembers:
+      return "keypaths with method members"
     }
   }
 

CodeGeneration/Sources/SyntaxSupport/ExprNodes.swift

@@ -1208,6 +1208,11 @@ public let EXPR_NODES: [Node] = [
             name: "property",
             kind: .node(kind: .keyPathPropertyComponent)
           ),
+          Child(
+            name: "method",
+            kind: .node(kind: .keyPathMethodComponent),
+            experimentalFeature: .keypathWithMethodMembers
+          ),
           Child(
             name: "subscript",
             kind: .node(kind: .keyPathSubscriptComponent)
@@ -1312,6 +1317,33 @@ public let EXPR_NODES: [Node] = [
     ]
   ),
 
+  Node(
+    kind: .keyPathMethodComponent,
+    base: .syntax,
+    experimentalFeature: .keypathWithMethodMembers,
+    nameForDiagnostics: "key path method component",
+    documentation: "A key path component like `.method()`, `.method(10)`, or `.method(val: 10)`.",
+    children: [
+      Child(
+        name: "declName",
+        kind: .node(kind: .declReferenceExpr)
+      ),
+      Child(
+        name: "leftParen",
+        kind: .token(choices: [.token(.leftParen)])
+      ),
+      Child(
+        name: "arguments",
+        kind: .collection(kind: .labeledExprList, collectionElementName: "Argument"),
+        nameForDiagnostics: "arguments"
+      ),
+      Child(
+        name: "rightParen",
+        kind: .token(choices: [.token(.rightParen)])
+      ),
+    ]
+  ),
+
   Node(
     kind: .macroExpansionExpr,
     base: .expr,

CodeGeneration/Sources/SyntaxSupport/SyntaxNodeKind.swift

@@ -182,6 +182,7 @@ public enum SyntaxNodeKind: String, CaseIterable, IdentifierConvertible, TypeCon
   case keyPathOptionalComponent
   case keyPathPropertyComponent
   case keyPathSubscriptComponent
+  case keyPathMethodComponent
   case labeledExpr
   case labeledExprList
   case labeledSpecializeArgument

CodeGeneration/Tests/ValidateSyntaxNodes/ValidateSyntaxNodes.swift

@@ -570,6 +570,10 @@ class ValidateSyntaxNodes: XCTestCase {
         ),
         ValidationFailure(node: .lifetimeTypeSpecifier, message: "could conform to trait 'Parenthesized' but does not"),
         ValidationFailure(node: .codeBlockFile, message: "could conform to trait 'WithCodeBlock' but does not"),
+        ValidationFailure(
+          node: .keyPathMethodComponent,
+          message: "could conform to trait 'Parenthesized' but does not"
+        ),
       ]
     )
   }

Sources/SwiftParser/Expressions.swift

@@ -11,9 +11,9 @@
 //===----------------------------------------------------------------------===//
 
 #if compiler(>=6)
-@_spi(RawSyntax) internal import SwiftSyntax
+@_spi(RawSyntax) @_spi(ExperimentalLanguageFeatures) internal import SwiftSyntax
 #else
-@_spi(RawSyntax) import SwiftSyntax
+@_spi(RawSyntax) @_spi(ExperimentalLanguageFeatures) import SwiftSyntax
 #endif
 
 extension TokenConsumer {
@@ -1127,11 +1127,54 @@ extension Parser {
         continue
       }
 
-      // Check for a .name or .1 suffix.
+      // Check for a .name, .1, .name(), .name("Kiwi"), .name(fruit:),
+      // .name(_:), .name(fruit: "Kiwi) suffix.
       if self.at(.period) {
         let (unexpectedPeriod, period, declName, generics) = parseDottedExpressionSuffix(
           previousNode: components.last?.raw ?? rootType?.raw ?? backslash.raw
         )
+
+        // If fully applied method component, parse as a keypath method.
+        if self.experimentalFeatures.contains(.keypathWithMethodMembers)
+          && self.at(.leftParen)
+        {
+          var (unexpectedBeforeLParen, leftParen) = self.expect(.leftParen)
+          if let generics = generics {
+            unexpectedBeforeLParen = RawUnexpectedNodesSyntax(
+              (unexpectedBeforeLParen?.elements ?? []) + [RawSyntax(generics)],
+              arena: self.arena
+            )
+          }
+          let args = self.parseArgumentListElements(
+            pattern: pattern,
+            allowTrailingComma: true
+          )
+          let (unexpectedBeforeRParen, rightParen) = self.expect(.rightParen)
+
+          components.append(
+            RawKeyPathComponentSyntax(
+              unexpectedPeriod,
+              period: period,
+              component: .method(
+                RawKeyPathMethodComponentSyntax(
+                  declName: declName,
+                  unexpectedBeforeLParen,
+                  leftParen: leftParen,
+                  arguments: RawLabeledExprListSyntax(
+                    elements: args,
+                    arena: self.arena
+                  ),
+                  unexpectedBeforeRParen,
+                  rightParen: rightParen,
+                  arena: self.arena
+                )
+              ),
+              arena: self.arena
+            )
+          )
+          continue
+        }
+        // Else, parse as a property.
         components.append(
           RawKeyPathComponentSyntax(
             unexpectedPeriod,
@@ -1152,7 +1195,6 @@ extension Parser {
       // No more postfix expressions.
       break
     }
-
     return RawKeyPathExprSyntax(
       unexpectedBeforeBackslash,
       backslash: backslash,

Sources/SwiftParser/generated/ExperimentalFeatures.swift

@@ -49,6 +49,9 @@ extension Parser.ExperimentalFeatures {
   /// Whether to enable the parsing of @abi attribute.
   public static let abiAttribute = Self (rawValue: 1 << 7)
 
+  /// Whether to enable the parsing of keypaths with method members.
+  public static let keypathWithMethodMembers = Self (rawValue: 1 << 8)
+
   /// Creates a new value representing the experimental feature with the
   /// given name, or returns nil if the name is not recognized.
   public init?(name: String) {
@@ -69,6 +72,8 @@ extension Parser.ExperimentalFeatures {
       self = .valueGenerics
     case "ABIAttribute":
       self = .abiAttribute
+    case "KeypathWithMethodMembers":
+      self = .keypathWithMethodMembers
     default:
       return nil
     }

Sources/SwiftParserDiagnostics/generated/ChildNameForDiagnostics.swift

@@ -207,6 +207,8 @@ private func childNameForDiagnostics(_ keyPath: AnyKeyPath) -> String? {
     return "generic where clause"
   case \KeyPathExprSyntax.root:
     return "root"
+  case \KeyPathMethodComponentSyntax.arguments:
+    return "arguments"
   case \KeyPathSubscriptComponentSyntax.arguments:
     return "arguments"
   case \LabeledExprSyntax.label:

Sources/SwiftParserDiagnostics/generated/SyntaxKindNameForDiagnostics.swift

@@ -250,6 +250,8 @@ extension SyntaxKind {
       return "key path component"
     case .keyPathExpr:
       return "key path"
+    case .keyPathMethodComponent:
+      return "key path method component"
     case .keyPathOptionalComponent:
       return "key path optional component"
     case .keyPathPropertyComponent:

Sources/SwiftSyntax/generated/ChildNameForKeyPath.swift

@@ -1952,6 +1952,24 @@ public func childName(_ keyPath: AnyKeyPath) -> String? {
     return "components"
   case \KeyPathExprSyntax.unexpectedAfterComponents:
     return "unexpectedAfterComponents"
+  case \KeyPathMethodComponentSyntax.unexpectedBeforeDeclName:
+    return "unexpectedBeforeDeclName"
+  case \KeyPathMethodComponentSyntax.declName:
+    return "declName"
+  case \KeyPathMethodComponentSyntax.unexpectedBetweenDeclNameAndLeftParen:
+    return "unexpectedBetweenDeclNameAndLeftParen"
+  case \KeyPathMethodComponentSyntax.leftParen:
+    return "leftParen"
+  case \KeyPathMethodComponentSyntax.unexpectedBetweenLeftParenAndArguments:
+    return "unexpectedBetweenLeftParenAndArguments"
+  case \KeyPathMethodComponentSyntax.arguments:
+    return "arguments"
+  case \KeyPathMethodComponentSyntax.unexpectedBetweenArgumentsAndRightParen:
+    return "unexpectedBetweenArgumentsAndRightParen"
+  case \KeyPathMethodComponentSyntax.rightParen:
+    return "rightParen"
+  case \KeyPathMethodComponentSyntax.unexpectedAfterRightParen:
+    return "unexpectedAfterRightParen"
   case \KeyPathOptionalComponentSyntax.unexpectedBeforeQuestionOrExclamationMark:
     return "unexpectedBeforeQuestionOrExclamationMark"
   case \KeyPathOptionalComponentSyntax.questionOrExclamationMark:

Sources/SwiftSyntax/generated/SyntaxAnyVisitor.swift

@@ -1325,6 +1325,16 @@ open class SyntaxAnyVisitor: SyntaxVisitor {
     visitAnyPost(node._syntaxNode)
   }
 
+  @_spi(ExperimentalLanguageFeatures)
+  override open func visit(_ node: KeyPathMethodComponentSyntax) -> SyntaxVisitorContinueKind {
+    return visitAny(node._syntaxNode)
+  }
+
+  @_spi(ExperimentalLanguageFeatures)
+  override open func visitPost(_ node: KeyPathMethodComponentSyntax) {
+    visitAnyPost(node._syntaxNode)
+  }
+
   override open func visit(_ node: KeyPathOptionalComponentSyntax) -> SyntaxVisitorContinueKind {
     return visitAny(node._syntaxNode)
   }