Merge pull request swiftlang#232 from google/format-swift5

Update to the Swift 5.0 version of SwiftSyntax.

Author: dabelknap

Package.resolved

@@ -6,17 +6,17 @@
         "repositoryURL": "https://github.com/apple/swift-package-manager.git",
         "state": {
           "branch": null,
-          "revision": "6983434787dec4e543e9d398a0a9acf63ccd4da1",
-          "version": "0.2.1"
+          "revision": "235aacc514cb81a6881364b0fedcb3dd083228f3",
+          "version": "0.3.0"
         }
       },
       {
         "package": "SwiftSyntax",
         "repositoryURL": "https://github.com/apple/swift-syntax",
         "state": {
           "branch": null,
-          "revision": "f20c0bcbfb4b07e107c9851350217cb2217f0cb4",
-          "version": "0.40200.0"
+          "revision": "43aa4a19b8105a803d8149ad2a86aa53a77efef3",
+          "version": "0.50000.0"
         }
       }
     ]

Package.swift

@@ -23,7 +23,7 @@ let package = Package(
   ],
   dependencies: [
     .package(url: "https://github.com/apple/swift-package-manager.git", from: "0.1.0"),
-    .package(url: "https://github.com/apple/swift-syntax", from: "0.40200.0"),
+    .package(url: "https://github.com/apple/swift-syntax", from: "0.50000.0"),
   ],
   targets: [
     .target(

Sources/SwiftFormat/SwiftLinter.swift

@@ -71,7 +71,7 @@ public final class SwiftLinter {
     let pipeline = LintPipeline(context: context)
     populate(pipeline)
 
-    pipeline.visit(syntax as Syntax)
+    syntax.walk(pipeline)
 
     // Perform whitespace linting by comparing the input source text with the output of the
     // pretty-printer.

Sources/SwiftFormatCore/LintPipeline.swift

@@ -14,6 +14,11 @@ import SwiftSyntax
 
 /// Manages a registry of lint rules to apply to specific kinds of nodes.
 public final class LintPipeline: SyntaxVisitor, Pipeline {
+  private enum Pass {
+    case linter(SyntaxLintRule)
+    case formatter(SyntaxFormatRule)
+  }
+
   private let context: Context
 
   /// Creates a Pipeline with the provided Context and Mode.
@@ -27,7 +32,7 @@ public final class LintPipeline: SyntaxVisitor, Pipeline {
   private var fileRules = [FileRule]()
 
   /// A mapping between syntax types and closures that will perform linting operations over them.
-  private var passMap = [SyntaxType: [(Syntax) -> Void]]()
+  private var passMap = [SyntaxType: [Pass]]()
 
   /// Adds a file-based rule to be run before format rules.
   ///
@@ -46,7 +51,7 @@ public final class LintPipeline: SyntaxVisitor, Pipeline {
   public func addLinter(_ lintRule: SyntaxLintRule.Type, for syntaxTypes: Syntax.Type...) {
     for type in syntaxTypes {
       let rule = lintRule.init(context: context)
-      passMap[SyntaxType(type: type), default: []].append(rule.visit)
+      passMap[SyntaxType(type: type), default: []].append(.linter(rule))
     }
   }
 
@@ -59,17 +64,20 @@ public final class LintPipeline: SyntaxVisitor, Pipeline {
   public func addFormatter(_ formatRule: SyntaxFormatRule.Type, for syntaxTypes: Syntax.Type...) {
     for type in syntaxTypes {
       let rule = formatRule.init(context: context)
-      passMap[SyntaxType(type: type), default: []].append {
-        _ = rule.visit($0)
-      }
+      passMap[SyntaxType(type: type), default: []].append(.formatter(rule))
     }
   }
 
   public override func visitPre(_ node: Syntax) {
     let syntaxType = SyntaxType(type: type(of: node))
     guard let passes = passMap[syntaxType] else { return }
     for pass in passes {
-      pass(node)
+      switch pass {
+      case .linter(let visitor):
+        node.walk(visitor)
+      case .formatter(let rewriter):
+        _ = rewriter.visit(node)
+      }
     }
   }
 }

Sources/SwiftFormatCore/Syntax+Convenience.swift

@@ -103,4 +103,51 @@ extension Syntax {
     }
     return nil
   }
+
+  /// Sequence of tokens that are part of this Syntax node.
+  public var tokens: TokenSequence {
+    return TokenSequence(self)
+  }
+}
+
+/// Sequence of tokens that are part of the provided Syntax node.
+public struct TokenSequence: Sequence {
+  public struct Iterator: IteratorProtocol {
+    var nextToken: TokenSyntax?
+    let endPosition: AbsolutePosition
+
+    init(_ token: TokenSyntax?, endPosition: AbsolutePosition) {
+      self.nextToken = token
+      self.endPosition = endPosition
+    }
+
+    public mutating func next() -> TokenSyntax? {
+      guard let token = self.nextToken else { return nil }
+      self.nextToken = token.nextToken
+      // Make sure we stop once we reach the end of the containing node.
+      if let nextTok = self.nextToken, nextTok.position >= self.endPosition {
+        self.nextToken = nil
+      }
+      return token
+    }
+  }
+
+  let node: Syntax
+
+  public init(_ node: Syntax) {
+    self.node = node
+  }
+
+  public func makeIterator() -> Iterator {
+    return Iterator(node.firstToken, endPosition: node.endPosition)
+  }
+}
+
+extension AbsolutePosition: Comparable {
+  public static func <(lhs: AbsolutePosition, rhs: AbsolutePosition) -> Bool {
+    return lhs.utf8Offset < rhs.utf8Offset
+  }
+  public static func ==(lhs: AbsolutePosition, rhs: AbsolutePosition) -> Bool {
+    return lhs.utf8Offset == rhs.utf8Offset
+  }
 }