Remove the with<childName> functions on syntax nodes

Instead, provide a single `with` function that takes a key path of the child you want to replace. This significatnly reduces the amout of code that is being generated for SwiftSyntax.

While at it, also remove the `without(Leading|Trailing)?Trivia` functions

Author: ahoppen

CodeGeneration/Sources/generate-swiftsyntax/templates/swiftsyntax/SyntaxCollectionsFile.swift

@@ -290,69 +290,6 @@ let syntaxCollectionsFile = SourceFileSyntax(leadingTrivia: [.blockComment(gener
         }
         """)
 
-      FunctionDeclSyntax("""
-        /// Returns a new `\(raw: node.name)` with its leading trivia replaced
-        /// by the provided trivia.
-        public func withLeadingTrivia(_ leadingTrivia: Trivia) -> \(raw: node.name) {
-          return \(raw: node.name)(data.withLeadingTrivia(leadingTrivia, arena: SyntaxArena()))
-        }
-        """)
-      
-      FunctionDeclSyntax("""
-        /// Returns a new `\(raw: node.name)` with its trailing trivia replaced
-        /// by the provided trivia.
-        public func withTrailingTrivia(_ trailingTrivia: Trivia) -> \(raw: node.name) {
-          return \(raw: node.name)(data.withTrailingTrivia(trailingTrivia, arena: SyntaxArena()))
-        }
-        """)
-      
-      FunctionDeclSyntax("""
-        /// Returns a new `\(raw: node.name)` with its leading trivia removed.
-        public func withoutLeadingTrivia() -> \(raw: node.name) {
-          return withLeadingTrivia([])
-        }
-        """)
-      
-      
-      FunctionDeclSyntax("""
-        /// Returns a new `\(raw: node.name)` with its trailing trivia removed.
-        public func withoutTrailingTrivia() -> \(raw: node.name) {
-          return withTrailingTrivia([])
-        }
-        """)
-      
-      
-      FunctionDeclSyntax("""
-        /// Returns a new `\(raw: node.name)` with all trivia removed.
-        public func withoutTrivia() -> \(raw: node.name) {
-          return withoutLeadingTrivia().withoutTrailingTrivia()
-        }
-        """)
-      
-      VariableDeclSyntax("""
-        /// The leading trivia (spaces, newlines, etc.) associated with this `\(raw: node.name)`.
-        public var leadingTrivia: Trivia? {
-          get {
-            return raw.formLeadingTrivia()
-          }
-          set {
-            self = withLeadingTrivia(newValue ?? [])
-          }
-        }
-        """)
-      
-      VariableDeclSyntax("""
-        /// The trailing trivia (spaces, newlines, etc.) associated with this `\(raw: node.name)`.
-        public var trailingTrivia: Trivia? {
-          get {
-            return raw.formTrailingTrivia()
-          }
-          set {
-            self = withTrailingTrivia(newValue ?? [])
-          }
-        }
-        """)
-      
       FunctionDeclSyntax("""
         public func childNameForDiagnostics(_ index: SyntaxChildrenIndex) -> String? {
           return nil

CodeGeneration/Sources/generate-swiftsyntax/templates/swiftsyntax/SyntaxTraitsFile.swift

@@ -24,10 +24,22 @@ let syntaxTraitsFile = SourceFileSyntax {
       """) {
 
       for child in trait.children {
-        VariableDeclSyntax("var \(raw: child.swiftName): \(raw: child.typeName)\(raw: child.isOptional ? "?" : "") { get }")
-        FunctionDeclSyntax("func with\(raw: child.name)(_ newChild: \(raw: child.typeName)\(raw: child.isOptional ? "?" : "")) -> Self")
+        VariableDeclSyntax("var \(raw: child.swiftName): \(raw: child.typeName)\(raw: child.isOptional ? "?" : "") { get set }")
       }
     }
+
+    ExtensionDeclSyntax("public extension \(trait.traitName)Syntax") {
+      FunctionDeclSyntax("""
+      /// Without this function, the `with` function defined on `SyntaxProtocol`
+      /// does not work on existentials of this protocol type.
+      @_disfavoredOverload
+      func with<T>(_ keyPath: WritableKeyPath<\(raw: trait.traitName)Syntax, T>, _ newChild: T) -> \(raw: trait.traitName)Syntax {
+        var copy: \(raw: trait.traitName)Syntax = self
+        copy[keyPath: keyPath] = newChild
+        return copy
+      }
+      """)
+    }
 
     ExtensionDeclSyntax("public extension SyntaxProtocol") {
       FunctionDeclSyntax("""

Sources/SwiftParserDiagnostics/DiagnosticExtensions.swift

@@ -77,10 +77,10 @@ extension FixIt.Changes {
   ) -> Self {
     var presentNode = PresentMaker().visit(Syntax(node))
     if let leadingTrivia = leadingTrivia {
-      presentNode = presentNode.withLeadingTrivia(leadingTrivia)
+      presentNode = presentNode.with(\.leadingTrivia, leadingTrivia)
     }
     if let trailingTrivia = trailingTrivia {
-      presentNode = presentNode.withTrailingTrivia(trailingTrivia)
+      presentNode = presentNode.with(\.trailingTrivia, trailingTrivia)
     }
     if node.shouldBeInsertedAfterNextTokenTrivia,
       let nextToken = node.nextToken(viewMode: .sourceAccurate),
@@ -89,7 +89,7 @@ extension FixIt.Changes {
       return [
         .replace(
           oldNode: Syntax(node),
-          newNode: Syntax(presentNode).withLeadingTrivia(nextToken.leadingTrivia)
+          newNode: Syntax(presentNode).with(\.leadingTrivia, nextToken.leadingTrivia)
         ),
         .replaceLeadingTrivia(token: nextToken, newTrivia: []),
       ]
@@ -105,7 +105,7 @@ extension FixIt.Changes {
       return [
         .replace(
           oldNode: Syntax(node),
-          newNode: Syntax(presentNode).withLeadingTrivia(.space)
+          newNode: Syntax(presentNode).with(\.leadingTrivia, .space)
         )
       ]
     } else {
@@ -123,7 +123,7 @@ extension FixIt.Changes {
     if let previousToken = token.previousToken(viewMode: .sourceAccurate) {
       var presentToken = PresentMaker().visit(token)
       if !previousToken.trailingTrivia.isEmpty {
-        presentToken = presentToken.withTrailingTrivia(previousToken.trailingTrivia)
+        presentToken = presentToken.with(\.trailingTrivia, previousToken.trailingTrivia)
       }
       return [
         .replaceTrailingTrivia(token: previousToken, newTrivia: []),

Sources/SwiftParserDiagnostics/MissingNodesError.swift

@@ -33,8 +33,8 @@ fileprivate enum NodesDescriptionPart {
         tokens = tokens.map({ BasicFormat().visit($0) })
       }
       if !tokens.isEmpty {
-        tokens[0] = tokens[0].withLeadingTrivia([])
-        tokens[tokens.count - 1] = tokens[tokens.count - 1].withTrailingTrivia([])
+        tokens[0] = tokens[0].with(\.leadingTrivia, [])
+        tokens[tokens.count - 1] = tokens[tokens.count - 1].with(\.trailingTrivia, [])
       }
       let tokenContents = tokens.map(\.description).joined()
       return "'\(tokenContents)'"

Sources/SwiftParserDiagnostics/ParseDiagnosticsGenerator.swift

@@ -525,7 +525,7 @@ public class ParseDiagnosticsGenerator: SyntaxAnyVisitor {
 
           let negatedAvailabilityKeyword = availability.availabilityKeyword.negatedAvailabilityKeyword
           let negatedCoditionElement = ConditionElementSyntax(
-            condition: .availability(availability.withAvailabilityKeyword(negatedAvailabilityKeyword)),
+            condition: .availability(availability.with(\.availabilityKeyword, negatedAvailabilityKeyword)),
             trailingComma: conditionElement.trailingComma
           )
           addDiagnostic(

Sources/SwiftParserDiagnostics/SyntaxExtensions.swift

@@ -71,7 +71,7 @@ extension SyntaxProtocol {
   /// diagnostic message), return that.
   /// Otherwise, return a generic message that describes the tokens in this node.
   var shortSingleLineContentDescription: String {
-    let contentWithoutTrivia = self.withoutLeadingTrivia().withoutTrailingTrivia().description
+    let contentWithoutTrivia = self.trimmedDescription
     if self.children(viewMode: .sourceAccurate).allSatisfy({ $0.as(TokenSyntax.self)?.tokenKind == .rightBrace }) {
       if self.children(viewMode: .sourceAccurate).count == 1 {
         return "brace"

Sources/SwiftRefactor/AddSeparatorsToIntegerLiteral.swift

@@ -51,7 +51,7 @@ public struct AddSeparatorsToIntegerLiteral: RefactoringProvider {
     formattedText += value.byAddingGroupSeparators(at: lit.idealGroupSize)
     return
       lit
-      .withDigits(lit.digits.withKind(.integerLiteral(formattedText)))
+      .with(\.digits, lit.digits.withKind(.integerLiteral(formattedText)))
   }
 }
 

Sources/SwiftRefactor/FormatRawStringLiteral.swift

@@ -49,15 +49,15 @@ public struct FormatRawStringLiteral: RefactoringProvider {
     guard maximumHashes > 0 else {
       return
         lit
-        .withOpenDelimiter(lit.openDelimiter?.withKind(.rawStringDelimiter("")))
-        .withCloseDelimiter(lit.closeDelimiter?.withKind(.rawStringDelimiter("")))
+        .with(\.openDelimiter, lit.openDelimiter?.withKind(.rawStringDelimiter("")))
+        .with(\.closeDelimiter, lit.closeDelimiter?.withKind(.rawStringDelimiter("")))
     }
 
     let delimiters = String(repeating: "#", count: maximumHashes + 1)
     return
       lit
-      .withOpenDelimiter(lit.openDelimiter?.withKind(.rawStringDelimiter(delimiters)))
-      .withCloseDelimiter(lit.closeDelimiter?.withKind(.rawStringDelimiter(delimiters)))
+      .with(\.openDelimiter, lit.openDelimiter?.withKind(.rawStringDelimiter(delimiters)))
+      .with(\.closeDelimiter, lit.closeDelimiter?.withKind(.rawStringDelimiter(delimiters)))
   }
 }
 

Sources/SwiftRefactor/MigrateToNewIfLetSyntax.swift

@@ -51,12 +51,12 @@ public struct MigrateToNewIfLetSyntax: RefactoringProvider {
         binding.initializer = nil
         // ... and remove whitespace before the comma (in `if` statements with multiple conditions).
         if index != node.conditions.count - 1 {
-          binding.pattern = binding.pattern.withoutTrailingTrivia()
+          binding.pattern = binding.pattern.with(\.trailingTrivia, [])
         }
         conditionCopy.condition = .optionalBinding(binding)
       }
       return conditionCopy
     }
-    return StmtSyntax(node.withConditions(ConditionElementListSyntax(newConditions)))
+    return StmtSyntax(node.with(\.conditions, ConditionElementListSyntax(newConditions)))
   }
 }

Sources/SwiftRefactor/OpaqueParameterToGeneric.swift

@@ -48,7 +48,7 @@ fileprivate class SomeParameterRewriter: SyntaxRewriter {
     let colon: TokenSyntax?
     if node.baseType.description != "Any" {
       colon = .colonToken()
-      inheritedType = node.baseType.withLeadingTrivia(.space)
+      inheritedType = node.baseType.with(\.leadingTrivia, .space)
     } else {
       colon = nil
       inheritedType = nil
@@ -143,8 +143,8 @@ public struct OpaqueParameterToGeneric: RefactoringProvider {
       // Add a trailing comma to the prior generic parameter, if there is one.
       if let lastNewGenericParam = newGenericParams.last {
         newGenericParams[newGenericParams.count - 1] =
-          lastNewGenericParam.withTrailingComma(.commaToken())
-        newGenericParams.append(newGenericParam.withLeadingTrivia(.space))
+          lastNewGenericParam.with(\.trailingComma, .commaToken())
+        newGenericParams.append(newGenericParam.with(\.leadingTrivia, .space))
       } else {
         newGenericParams.append(newGenericParam)
       }
@@ -153,7 +153,8 @@ public struct OpaqueParameterToGeneric: RefactoringProvider {
     let newGenericParamSyntax = GenericParameterListSyntax(newGenericParams)
     let newGenericParamClause: GenericParameterClauseSyntax
     if let genericParams = genericParams {
-      newGenericParamClause = genericParams.withGenericParameterList(
+      newGenericParamClause = genericParams.with(
+        \.genericParameterList,
         newGenericParamSyntax
       )
     } else {
@@ -166,7 +167,7 @@ public struct OpaqueParameterToGeneric: RefactoringProvider {
     }
 
     return (
-      params.withParameterList(rewrittenParams),
+      params.with(\.parameterList, rewrittenParams),
       newGenericParamClause
     )
   }
@@ -188,8 +189,8 @@ public struct OpaqueParameterToGeneric: RefactoringProvider {
 
       return DeclSyntax(
         funcSyntax
-          .withSignature(funcSyntax.signature.withInput(newInput))
-          .withGenericParameterClause(newGenericParams)
+          .with(\.signature, funcSyntax.signature.with(\.input, newInput))
+          .with(\.genericParameterClause, newGenericParams)
       )
     }
 
@@ -206,8 +207,8 @@ public struct OpaqueParameterToGeneric: RefactoringProvider {
 
       return DeclSyntax(
         initSyntax
-          .withSignature(initSyntax.signature.withInput(newInput))
-          .withGenericParameterClause(newGenericParams)
+          .with(\.signature, initSyntax.signature.with(\.input, newInput))
+          .with(\.genericParameterClause, newGenericParams)
       )
     }
 
@@ -224,8 +225,8 @@ public struct OpaqueParameterToGeneric: RefactoringProvider {
 
       return DeclSyntax(
         subscriptSyntax
-          .withIndices(newIndices)
-          .withGenericParameterClause(newGenericParams)
+          .with(\.indices, newIndices)
+          .with(\.genericParameterClause, newGenericParams)
       )
     }
 

Sources/SwiftRefactor/RefactoringProvider.swift

@@ -32,7 +32,7 @@ import SwiftSyntax
 /// syntax trees. The SwiftSyntax API provides a natural, easy-to-use,
 /// and compositional set of updates to the syntax tree. For example, a
 /// refactoring action that wishes to exchange the leading trivia of a node
-/// would call `withLeadingTrivia(_:)` against its input syntax and return
+/// would call `with(\.leadingTrivia, _:)` against its input syntax and return
 /// the resulting syntax node. For compound syntax nodes, entire sub-trees
 /// can be added, exchanged, or removed by calling the corresponding `with`
 /// API.

Sources/SwiftRefactor/RemoveSeparatorsFromIntegerLiteral.swift

@@ -32,8 +32,6 @@ public struct RemoveSeparatorsFromIntegerLiteral: RefactoringProvider {
       return lit
     }
     let formattedText = lit.digits.text.filter({ $0 != "_" })
-    return
-      lit
-      .withDigits(lit.digits.withKind(.integerLiteral(formattedText)))
+    return lit.with(\.digits, lit.digits.withKind(.integerLiteral(formattedText)))
   }
 }

Sources/SwiftSyntax/Documentation.docc/Resources/Formatter.step11.swift

@@ -50,8 +50,8 @@ import Foundation
       case .import(_, let statement):
         return
           statement
-          .withLeadingTrivia(offset == 0 ? [] : .newline)
-          .withTrailingTrivia([])
+          .with(\.leadingTrivia, offset == 0 ? [] : .newline)
+          .with(\.trailingTrivia, [])
       case .other(let statement):
         return statement
       }

Sources/SwiftSyntax/Documentation.docc/Tutorials/SwiftSyntax By Example.tutorial

@@ -212,14 +212,14 @@
 
       @Step {
         Normalize the whitespace of all the imports by calling the trivia 
-        manipulation functions `withLeadingTrivia(_:)` and 
-        `withTrailingTrivia(_:)` on import items.
+        manipulation functions `with(\.leadingTrivia, _:)` and 
+        `with(\.trailingTrivia, _:)` on import items.
 
         SwiftSyntax does not automatically format whitespace and trivia when
         items are moved around. SwiftSyntax provides a convenient way of 
         manipulating whitespace by calling the 
-        `withLeadingTrivia(_:)` and 
-        `withTrailingTrivia(_:)` methods. By normalizing all
+        `with(\.leadingTrivia, _:)` and 
+        `with(\.trailingTrivia, _:)` methods. By normalizing all
         of the whitespace to a single leading newline we can fix bug #1. And
         by removing all trailing whitespace we can fix bug #2.