Generate Format using SwiftSyntaxBuilder

Sources/SwiftSyntaxBuilder/VariableDeclConvenienceInitializers.swift

@@ -15,12 +15,13 @@ import SwiftSyntax
 extension VariableDecl {
   public init(
     leadingTrivia: Trivia = [],
+    modifiers: ModifierList? = nil,
     _ letOrVarKeyword: TokenSyntax,
     name: ExpressibleAsIdentifierPattern,
     type: ExpressibleAsTypeAnnotation? = nil,
     initializer: ExpressibleAsInitializerClause? = nil
   ) {
-    self.init(leadingTrivia: leadingTrivia, letOrVarKeyword: letOrVarKeyword) {
+    self.init(leadingTrivia: leadingTrivia, modifiers: modifiers, letOrVarKeyword: letOrVarKeyword) {
       PatternBinding(
         pattern: name,
         typeAnnotation: type,

Sources/SwiftSyntaxBuilder/Format.swift → Sources/SwiftSyntaxBuilder/generated/Format.swift

@@ -1,3 +1,6 @@
+
+//// Automatically Generated by generate-swift-syntax-builder
+//// Do Not Edit Directly!
 //===----------------------------------------------------------------------===//
 //
 // This source file is part of the Swift.org open source project
@@ -11,24 +14,19 @@
 //===----------------------------------------------------------------------===//
 
 import SwiftSyntax
-
 public struct Format {
   public let indentWidth: Int
-
   private var indents: Int = 0
-
-  public init(indentWidth: Int = 4) {
+  public init (indentWidth: Int = 4) {
     self.indentWidth = indentWidth
   }
 }
-
 extension Format {
   public func _indented() -> Format {
     var copy = self
     copy.indents += 1
     return copy
   }
-
   public func _makeIndent() -> Trivia {
     return indents == 0 ? .zero : Trivia.spaces(indents * indentWidth)
   }

Sources/generate-swift-syntax-builder/Templates/FormatFile.swift

@@ -0,0 +1,106 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2022 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
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import Foundation
+import SwiftSyntax
+import SwiftSyntaxBuilder
+
+let formatFile = SourceFile {
+  ImportDecl(
+    leadingTrivia: .docLineComment(copyrightHeader),
+    path: "SwiftSyntax"
+  )
+
+  StructDecl(modifiers: [TokenSyntax.public], identifier: "Format") {
+    VariableDecl(
+      modifiers: [TokenSyntax.public],
+      .let,
+      name: "indentWidth",
+      type: "Int"
+    )
+
+    VariableDecl(
+      modifiers: [TokenSyntax.private],
+      .var,
+      name: "indents",
+      type: "Int",
+      initializer: IntegerLiteralExpr(0)
+    )
+
+    InitializerDecl(
+      modifiers: [TokenSyntax.public],
+      signature: FunctionSignature(
+        input: ParameterClause {
+          FunctionParameter(
+            firstName: .identifier("indentWidth"),
+            colon: .colon,
+            type: "Int",
+            defaultArgument: IntegerLiteralExpr(4)
+          )
+        }
+      )
+    ) {
+      SequenceExpr {
+        MemberAccessExpr(base: "self", name: "indentWidth")
+        AssignmentExpr()
+        "indentWidth"
+      }
+    }
+  }
+
+  ExtensionDecl(extendedType: "Format") {
+    FunctionDecl(
+      modifiers: [TokenSyntax.public],
+      identifier: .identifier("_indented"),
+      signature: FunctionSignature(
+        input: ParameterClause(),
+        output: "Format"
+      )
+    ) {
+      VariableDecl(.var, name: "copy", initializer: "self")
+      SequenceExpr {
+        MemberAccessExpr(base: "copy", name: "indents")
+        BinaryOperatorExpr("+=")
+        IntegerLiteralExpr(1)
+      }
+      ReturnStmt(expression: "copy")
+    }
+
+    FunctionDecl(
+      modifiers: [TokenSyntax.public],
+      identifier: .identifier("_makeIndent"),
+      signature: FunctionSignature(
+        input: ParameterClause(),
+        output: "Trivia"
+      )
+    ) {
+      // TODO: Use sugared TernaryExpr once https://github.com/apple/swift-syntax/pull/610 is merged
+      ReturnStmt(expression: TernaryExpr(
+        conditionExpression: SequenceExpr {
+          "indents"
+          BinaryOperatorExpr("==")
+          IntegerLiteralExpr(0)
+        },
+        questionMark: .infixQuestionMark.withLeadingTrivia(.space).withTrailingTrivia(.space),
+        firstChoice: MemberAccessExpr(name: "zero"),
+        colonMark: .colon.withLeadingTrivia(.space).withTrailingTrivia(.space),
+        secondChoice: FunctionCallExpr(MemberAccessExpr(base: "Trivia", name: "spaces")) {
+          TupleExprElement(expression: SequenceExpr {
+            "indents"
+            BinaryOperatorExpr("*")
+            "indentWidth"
+          })
+        }
+      ))
+    }
+  }
+}

Sources/generate-swift-syntax-builder/main.swift

@@ -20,6 +20,7 @@ let sourceTemplates = [
   (buildableCollectionNodesFile, "BuildableCollectionNodes.swift"),
   (buildableNodesFile, "BuildableNodes.swift"),
   (expressibleAsProtocolsFile, "ExpressibleAsProtocols.swift"),
+  (formatFile, "Format.swift"),
   (tokensFile, "Tokens.swift"),
   (tokenSyntaxFile, "TokenSyntax.swift"),
 ]