[Parse] Rename Lexer::State to LexerState

Author: rintaro

include/swift/Parse/Lexer.h

@@ -20,6 +20,7 @@
 #include "swift/AST/DiagnosticEngine.h"
 #include "swift/Basic/SourceLoc.h"
 #include "swift/Basic/SourceManager.h"
+#include "swift/Parse/LexerState.h"
 #include "swift/Parse/Token.h"
 #include "swift/Syntax/References.h"
 #include "swift/Syntax/Trivia.h"
@@ -59,13 +60,15 @@ enum class ConflictMarkerKind {
   /// separated by 4 "="s, and terminated by 4 "<"s.
   Perforce
 };
-  
+
 class Lexer {
   const LangOptions &LangOpts;
   const SourceManager &SourceMgr;
   DiagnosticEngine *Diags;
   const unsigned BufferID;
 
+  using State = LexerState;
+
   /// Pointer to the first character of the buffer, even in a lexer that
   /// scans a subrange of the buffer.
   const char *BufferStart;
@@ -128,28 +131,6 @@ class Lexer {
   /// `TriviaRetentionMode::WithTrivia`.
   syntax::TriviaList TrailingTrivia;
 
-public:
-  /// \brief Lexer state can be saved/restored to/from objects of this class.
-  class State {
-  public:
-    State() {}
-
-    bool isValid() const {
-      return Loc.isValid();
-    }
-
-    State advance(unsigned Offset) const {
-      assert(isValid());
-      return State(Loc.getAdvancedLoc(Offset));
-    }
-
-  private:
-    explicit State(SourceLoc Loc) : Loc(Loc) {}
-    SourceLoc Loc;
-    friend class Lexer;
-  };
-
-private:
   Lexer(const Lexer&) = delete;
   void operator=(const Lexer&) = delete;
 

include/swift/Parse/LexerState.h

@@ -0,0 +1,45 @@
+//===--- LexerState.h - Lexer State -----------------------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2017 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
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the LexerState object.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_LEXERSTATE_H
+#define SWIFT_LEXERSTATE_H
+
+#include "swift/Basic/SourceLoc.h"
+
+namespace swift {
+  class Lexer;
+
+/// \brief Lexer state can be saved/restored to/from objects of this class.
+class LexerState {
+public:
+  LexerState() {}
+
+  bool isValid() const { return Loc.isValid(); }
+
+  LexerState advance(unsigned Offset) const {
+    assert(isValid());
+    return LexerState(Loc.getAdvancedLoc(Offset));
+  }
+
+private:
+  explicit LexerState(SourceLoc Loc) : Loc(Loc) {}
+  SourceLoc Loc;
+  friend class Lexer;
+};
+
+} // end namespace swift
+
+#endif

include/swift/Parse/Parser.h

@@ -368,10 +368,10 @@ class Parser {
     }
 
   private:
-    ParserPosition(Lexer::State LS, SourceLoc PreviousLoc):
+    ParserPosition(LexerState LS, SourceLoc PreviousLoc):
         LS(LS), PreviousLoc(PreviousLoc)
     {}
-    Lexer::State LS;
+    LexerState LS;
     SourceLoc PreviousLoc;
     friend class Parser;
   };

lib/Parse/ParseExpr.cpp

@@ -1926,13 +1926,13 @@ ParserResult<Expr> Parser::parseExprStringLiteral() {
       TmpContext.setDiscard();
 
       // Create a temporary lexer that lexes from the body of the string.
-      Lexer::State BeginState =
+      LexerState BeginState =
           L->getStateForBeginningOfTokenLoc(Segment.Loc);
       // We need to set the EOF at r_paren, to prevent the Lexer from eagerly
       // trying to lex the token beyond it. Parser::parseList() does a special
       // check for a tok::EOF that is spelled with a ')'.
       // FIXME: This seems like a hack, there must be a better way..
-      Lexer::State EndState = BeginState.advance(Segment.Length-1);
+      LexerState EndState = BeginState.advance(Segment.Length-1);
       Lexer LocalLex(*L, BeginState, EndState);
 
       // Temporarily swap out the parser's current lexer with our new one.
@@ -2235,8 +2235,8 @@ Expr *Parser::parseExprEditorPlaceholder(Token PlaceholderTok,
       SourceLoc TypeStartLoc = PlaceholderTok.getLoc().getAdvancedLoc(Offset);
       SourceLoc TypeEndLoc = TypeStartLoc.getAdvancedLoc(TyStr.size());
 
-      Lexer::State StartState = L->getStateForBeginningOfTokenLoc(TypeStartLoc);
-      Lexer::State EndState = L->getStateForBeginningOfTokenLoc(TypeEndLoc);
+      LexerState StartState = L->getStateForBeginningOfTokenLoc(TypeStartLoc);
+      LexerState EndState = L->getStateForBeginningOfTokenLoc(TypeEndLoc);
 
       // Create a lexer for the type sub-string.
       Lexer LocalLex(*L, StartState, EndState);