Refactor syntax node manipulation to use variable setters

This commit replaces the use of 'with' method for syntax node manipulation in SwiftSyntax examples with direct variable setters for better clarity and readability.

Author: Matejkob

Examples/Sources/AddOneToIntegerLiterals/AddOneToIntegerLiterals.swift

@@ -31,7 +31,8 @@ private class AddOneToIntegerLiterals: SyntaxRewriter {
     let int = Int(integerText)!
 
     // Create a new integer literal token with `int + 1` as its text.
-    let newIntegerLiteralToken = token.with(\.tokenKind, .integerLiteral("\(int + 1)"))
+    var newIntegerLiteralToken = token
+    newIntegerLiteralToken.tokenKind = .integerLiteral("\(int + 1)")
 
     // Return the new integer literal.
     return newIntegerLiteralToken

Examples/Sources/MacroExamples/Implementation/ComplexMacros/DictionaryIndirectionMacro.swift

@@ -21,10 +21,7 @@ extension DictionaryStorageMacro: MemberMacro {
     providingMembersOf declaration: some DeclGroupSyntax,
     in context: some MacroExpansionContext
   ) throws -> [DeclSyntax] {
-    let storage: DeclSyntax = "var _storage: [String: Any] = [:]"
-    return [
-      storage.with(\.leadingTrivia, [.newlines(1), .spaces(2)])
-    ]
+    return ["\n  var _storage: [String: Any] = [:]"]
   }
 }
 
@@ -43,11 +40,11 @@ extension DictionaryStorageMacro: MemberAttributeMacro {
 
     return [
       AttributeSyntax(
+        leadingTrivia: [.newlines(1), .spaces(2)],
         attributeName: IdentifierTypeSyntax(
           name: .identifier("DictionaryStorageProperty")
         )
       )
-      .with(\.leadingTrivia, [.newlines(1), .spaces(2)])
     ]
   }
 }

Examples/Sources/MacroExamples/Implementation/Expression/AddBlocker.swift

@@ -27,7 +27,7 @@ public struct AddBlocker: ExpressionMacro {
       _ node: InfixOperatorExprSyntax
     ) -> ExprSyntax {
       // Identify any infix operator + in the tree.
-      if let binOp = node.operator.as(BinaryOperatorExprSyntax.self) {
+      if var binOp = node.operator.as(BinaryOperatorExprSyntax.self) {
         if binOp.operator.text == "+" {
           // Form the warning
           let messageID = MessageID(domain: "silly", id: "addblock")
@@ -72,17 +72,9 @@ public struct AddBlocker: ExpressionMacro {
             )
           )
 
-          return ExprSyntax(
-            node.with(
-              \.operator,
-              ExprSyntax(
-                binOp.with(
-                  \.operator,
-                  binOp.operator.with(\.tokenKind, .binaryOperator("-"))
-                )
-              )
-            )
-          )
+          binOp.operator.tokenKind = .binaryOperator("-")
+
+          return ExprSyntax(node.with(\.operator, ExprSyntax(binOp)))
         }
       }
 

Examples/Sources/MacroExamples/Implementation/Expression/FontLiteralMacro.swift

@@ -35,14 +35,12 @@ private func replaceFirstLabel(
   of tuple: LabeledExprListSyntax,
   with newLabel: String
 ) -> LabeledExprListSyntax {
-  guard let firstElement = tuple.first else {
+  if tuple.isEmpty {
     return tuple
   }
 
   var tuple = tuple
-  tuple[tuple.startIndex] =
-    firstElement
-    .with(\.label, .identifier(newLabel))
-    .with(\.colon, .colonToken())
+  tuple[tuple.startIndex].label = .identifier(newLabel)
+  tuple[tuple.startIndex].colon = .colonToken()
   return tuple
 }

Examples/Sources/MacroExamples/Implementation/MemberAttribute/WrapStoredPropertiesMacro.swift

@@ -48,11 +48,11 @@ public struct WrapStoredPropertiesMacro: MemberAttributeMacro {
 
     return [
       AttributeSyntax(
+        leadingTrivia: [.newlines(1), .spaces(2)],
         attributeName: IdentifierTypeSyntax(
           name: .identifier(wrapperName.content.text)
         )
       )
-      .with(\.leadingTrivia, [.newlines(1), .spaces(2)])
     ]
   }
 }

Examples/Sources/MacroExamples/Implementation/Peer/AddAsyncMacro.swift

@@ -30,7 +30,7 @@ public struct AddAsyncMacro: PeerMacro {
   ) throws -> [DeclSyntax] {
 
     // Only on functions at the moment.
-    guard let funcDecl = declaration.as(FunctionDeclSyntax.self) else {
+    guard var funcDecl = declaration.as(FunctionDeclSyntax.self) else {
       throw CustomError.message("@addAsync only works on functions")
     }
 
@@ -42,7 +42,7 @@ public struct AddAsyncMacro: PeerMacro {
     }
 
     // This only makes sense void functions
-    if funcDecl.signature.returnClause?.type.with(\.leadingTrivia, []).with(\.trailingTrivia, []).description != "Void" {
+    if funcDecl.signature.returnClause?.type.as(IdentifierTypeSyntax.self)?.name.text != "Void" {
       throw CustomError.message(
         "@addAsync requires an function that returns void"
       )
@@ -58,7 +58,7 @@ public struct AddAsyncMacro: PeerMacro {
     }
 
     // Completion handler needs to return Void
-    if completionHandlerParameter.returnClause.type.with(\.leadingTrivia, []).with(\.trailingTrivia, []).description != "Void" {
+    if completionHandlerParameter.returnClause.type.as(IdentifierTypeSyntax.self)?.name.text != "Void" {
       throw CustomError.message(
         "@addAsync requires an function that has a completion handler that returns Void"
       )
@@ -72,9 +72,11 @@ public struct AddAsyncMacro: PeerMacro {
     // Remove completionHandler and comma from the previous parameter
     var newParameterList = funcDecl.signature.parameterClause.parameters
     newParameterList.removeLast()
-    let newParameterListLastParameter = newParameterList.last!
+    var newParameterListLastParameter = newParameterList.last!
     newParameterList.removeLast()
-    newParameterList.append(newParameterListLastParameter.with(\.trailingTrivia, []).with(\.trailingComma, nil))
+    newParameterListLastParameter.trailingTrivia = []
+    newParameterListLastParameter.trailingComma = nil
+    newParameterList.append(newParameterListLastParameter)
 
     // Drop the @addAsync attribute from the new declaration.
     let newAttributeList = funcDecl.attributes.filter {
@@ -121,42 +123,36 @@ public struct AddAsyncMacro: PeerMacro {
 
       """
 
-    let newFunc =
-      funcDecl
-      .with(
-        \.signature,
-        funcDecl.signature
-          .with(
-            \.effectSpecifiers,
-            FunctionEffectSpecifiersSyntax(
-              leadingTrivia: .space,
-              asyncSpecifier: .keyword(.async),
-              throwsSpecifier: isResultReturn ? .keyword(.throws) : nil
-            )  // add async
-          )
-          .with(
-            \.returnClause,
-            successReturnType != nil ? ReturnClauseSyntax(leadingTrivia: .space, type: successReturnType!.with(\.leadingTrivia, .space)) : nil
-          )  // add result type
-          .with(
-            \.parameterClause,
-            funcDecl.signature.parameterClause.with(\.parameters, newParameterList)  // drop completion handler
-              .with(\.trailingTrivia, [])
-          )
-      )
-      .with(
-        \.body,
-        CodeBlockSyntax(
-          leftBrace: .leftBraceToken(leadingTrivia: .space),
-          statements: CodeBlockItemListSyntax(
-            [CodeBlockItemSyntax(item: .expr(newBody))]
-          ),
-          rightBrace: .rightBraceToken(leadingTrivia: .newline)
-        )
-      )
-      .with(\.attributes, newAttributeList)
-      .with(\.leadingTrivia, .newlines(2))
+    // add async
+    funcDecl.signature.effectSpecifiers = FunctionEffectSpecifiersSyntax(
+      leadingTrivia: .space,
+      asyncSpecifier: .keyword(.async),
+      throwsSpecifier: isResultReturn ? .keyword(.throws) : nil
+    )
+
+    // add result type
+    if let successReturnType {
+      funcDecl.signature.returnClause = ReturnClauseSyntax(leadingTrivia: .space, type: successReturnType.with(\.leadingTrivia, .space))
+    } else {
+      funcDecl.signature.returnClause = nil
+    }
+
+    // drop completion handler
+    funcDecl.signature.parameterClause.parameters = newParameterList
+    funcDecl.signature.parameterClause.trailingTrivia = []
+
+    funcDecl.body = CodeBlockSyntax(
+      leftBrace: .leftBraceToken(leadingTrivia: .space),
+      statements: CodeBlockItemListSyntax(
+        [CodeBlockItemSyntax(item: .expr(newBody))]
+      ),
+      rightBrace: .rightBraceToken(leadingTrivia: .newline)
+    )
+
+    funcDecl.attributes = newAttributeList
+
+    funcDecl.leadingTrivia = .newlines(2)
 
-    return [DeclSyntax(newFunc)]
+    return [DeclSyntax(funcDecl)]
   }
 }

Examples/Sources/MacroExamples/Implementation/Peer/AddCompletionHandlerMacro.swift

@@ -25,20 +25,22 @@ public struct AddCompletionHandlerMacro: PeerMacro {
   ) throws -> [DeclSyntax] {
     // Only on functions at the moment. We could handle initializers as well
     // with a bit of work.
-    guard let funcDecl = declaration.as(FunctionDeclSyntax.self) else {
+    guard var funcDecl = declaration.as(FunctionDeclSyntax.self) else {
       throw CustomError.message("@addCompletionHandler only works on functions")
     }
 
     // This only makes sense for async functions.
     if funcDecl.signature.effectSpecifiers?.asyncSpecifier == nil {
-      let newEffects: FunctionEffectSpecifiersSyntax
+      var newEffects: FunctionEffectSpecifiersSyntax
       if let existingEffects = funcDecl.signature.effectSpecifiers {
-        newEffects = existingEffects.with(\.asyncSpecifier, .keyword(.async))
+        newEffects = existingEffects
+        newEffects.asyncSpecifier = .keyword(.async)
       } else {
         newEffects = FunctionEffectSpecifiersSyntax(asyncSpecifier: .keyword(.async))
       }
 
-      let newSignature = funcDecl.signature.with(\.effectSpecifiers, newEffects)
+      var newSignature = funcDecl.signature
+      newSignature.effectSpecifiers = newEffects
       let messageID = MessageID(domain: "MacroExamples", id: "MissingAsync")
 
       let diag = Diagnostic(
@@ -73,7 +75,9 @@ public struct AddCompletionHandlerMacro: PeerMacro {
     }
 
     // Form the completion handler parameter.
-    let resultType: TypeSyntax? = funcDecl.signature.returnClause?.type.with(\.leadingTrivia, []).with(\.trailingTrivia, [])
+    var resultType = funcDecl.signature.returnClause?.type
+    resultType?.leadingTrivia = []
+    resultType?.trailingTrivia = []
 
     let completionHandlerParam =
       FunctionParameterSyntax(
@@ -85,14 +89,12 @@ public struct AddCompletionHandlerMacro: PeerMacro {
     // Add the completion handler parameter to the parameter list.
     let parameterList = funcDecl.signature.parameterClause.parameters
     var newParameterList = parameterList
-    if let lastParam = parameterList.last {
+    if var lastParam = parameterList.last {
       // We need to add a trailing comma to the preceding list.
       newParameterList.removeLast()
+      lastParam.trailingComma = .commaToken(trailingTrivia: .space)
       newParameterList += [
-        lastParam.with(
-          \.trailingComma,
-          .commaToken(trailingTrivia: .space)
-        ),
+        lastParam,
         completionHandlerParam,
       ]
     } else {
@@ -136,35 +138,28 @@ public struct AddCompletionHandlerMacro: PeerMacro {
       return attributeType.name.text != nodeType.name.text
     }
 
-    let newFunc =
-      funcDecl
-      .with(
-        \.signature,
-        funcDecl.signature
-          .with(
-            \.effectSpecifiers,
-            funcDecl.signature.effectSpecifiers?.with(\.asyncSpecifier, nil)  // drop async
-          )
-          .with(\.returnClause, nil)  // drop result type
-          .with(
-            \.parameterClause,  // add completion handler parameter
-            funcDecl.signature.parameterClause.with(\.parameters, newParameterList)
-              .with(\.trailingTrivia, [])
-          )
-      )
-      .with(
-        \.body,
-        CodeBlockSyntax(
-          leftBrace: .leftBraceToken(leadingTrivia: .space),
-          statements: CodeBlockItemListSyntax(
-            [CodeBlockItemSyntax(item: .expr(newBody))]
-          ),
-          rightBrace: .rightBraceToken(leadingTrivia: .newline)
-        )
-      )
-      .with(\.attributes, newAttributeList)
-      .with(\.leadingTrivia, .newlines(2))
+    // drop async
+    funcDecl.signature.effectSpecifiers?.asyncSpecifier = nil
+
+    // drop result type
+    funcDecl.signature.returnClause = nil
+
+    // add completion handler parameter
+    funcDecl.signature.parameterClause.parameters = newParameterList
+    funcDecl.signature.parameterClause.trailingTrivia = []
+
+    funcDecl.body = CodeBlockSyntax(
+      leftBrace: .leftBraceToken(leadingTrivia: .space),
+      statements: CodeBlockItemListSyntax(
+        [CodeBlockItemSyntax(item: .expr(newBody))]
+      ),
+      rightBrace: .rightBraceToken(leadingTrivia: .newline)
+    )
+
+    funcDecl.attributes = newAttributeList
+
+    funcDecl.leadingTrivia = .newlines(2)
 
-    return [DeclSyntax(newFunc)]
+    return [DeclSyntax(funcDecl)]
   }
 }

Examples/Sources/MacroExamples/Playground/PeerMacrosPlayground.swift

@@ -54,7 +54,7 @@ func runPeerMacrosPlayground() {
     var value = 0
   }
 
-  let counter = Counter()
+  _ = Counter()
 
   //  print("Peer value with suffix name for \(Counter.self): \(String(describing: Counter_peer))")
 }