Indent fix for trailing comments (dartbug.com/16383).

pkg/analyzer/lib/src/services/writer.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library source_writer;
 
 
 
 class Line {
 
-  final tokens = <LineToken>[];
+  final List<LineToken> tokens = <LineToken>[];
   final bool useTabs;
   final int spacesPerIndent;
-  final int indent;
+  final int indentLevel;
   final LinePrinter printer;
 
-  Line({this.indent: 0, this.useTabs: false, this.spacesPerIndent: 2,
+  Line({this.indentLevel: 0, this.useTabs: false, this.spacesPerIndent: 2,
       this.printer: const SimpleLinePrinter()}) {
-    if (indent > 0) {
-      _indent(indent);
+    if (indentLevel > 0) {
+      indent(indentLevel);
     }
   }
 
   void addSpace() {
     addSpaces(1);
   }
 
   void addSpaces(int n, {breakWeight: DEFAULT_SPACE_WEIGHT}) {
     if (n > 0) {
       tokens.add(new SpaceToken(n, breakWeight: breakWeight));
     }
   }
 
   void addToken(LineToken token) {
     tokens.add(token);
   }
 
+  bool isEmpty() => tokens.isEmpty;
+
   bool isWhitespace() => tokens.every((tok) => tok is SpaceToken);
 
-  void _indent(int n) {
-    tokens.add(useTabs ? new TabToken(n) : new SpaceToken(n * spacesPerIndent));
+  void indent(int n) {
+    tokens.insert(0,
+        useTabs ? new TabToken(n) : new SpaceToken(n * spacesPerIndent));
   }
 
   String toString() => printer.printLine(this);
 
 }
 
 
 /// Base class for line printers
 abstract class LinePrinter {
 
@@ skipping 20 matching lines @@
     if (indenter == null) {
       indenter = NO_OP_INDENTER;
     }
   }
 
   String printLine(Line line) {
     var buf = new StringBuffer();
     var chunks = breakLine(line);
     for (var i = 0; i < chunks.length; ++i) {
       if (i > 0) {
-        buf.write(indent(chunks[i], line.indent));
+        buf.write(indent(chunks[i], line.indentLevel));
       } else {
         buf.write(chunks[i]);
       }
     }
     return buf.toString();
   }
 
   String indent(Chunk chunk, int level) =>
       '\n' + indenter(level + 2) + chunk.toString();
 
@@ skipping 209 matching lines @@
   LineToken _lastToken;
 
   SourceWriter({this.indentCount: 0, this.lineSeparator: NEW_LINE,
       bool useTabs: false, int spacesPerIndent: 2, int maxLineLength: 80}) {
     if (maxLineLength > 0) {
       linePrinter = new SimpleLineBreaker(maxLineLength, (n) =>
           getIndentString(n, useTabs: useTabs, spacesPerIndent: spacesPerIndent));
     } else {
       linePrinter = new SimpleLinePrinter();
     }
-    currentLine = new Line(indent: indentCount, printer: linePrinter);
+    currentLine = newLine();
   }
 
   LineToken get lastToken => _lastToken;
 
   _addToken(LineToken token) {
     _lastToken = token;
     currentLine.addToken(token);
   }
 
   void indent() {
     ++indentCount;
+    // Rather than fiddle with deletions/insertions just start fresh
+    if (currentLine.isWhitespace()) {
+      currentLine = newLine();
+    }
   }
 
   void newline() {
     if (currentLine.isWhitespace()) {
       currentLine.tokens.clear();
     }
     _addToken(new NewlineToken(this.lineSeparator));
     buffer.write(currentLine.toString());
-    currentLine = new Line(indent: indentCount, printer: linePrinter);
+    currentLine = newLine();
   }
 
   void newlines(int num) {
     while (num-- > 0) {
       newline();
     }
   }
 
-  void print(x) {
+  void write(x) {
     _addToken(new LineToken(x));
   }
 
-  void println(String s) {
-    print(s);
+  void writeln(String s) {
+    write(s);
     newline();
   }
 
   void space() {
     spaces(1);
   }
 
   void spaces(n, {breakWeight: DEFAULT_SPACE_WEIGHT}) {
     currentLine.addSpaces(n, breakWeight: breakWeight);
   }
 
   void unindent() {
     --indentCount;
+    // Rather than fiddle with deletions/insertions just start fresh
+    if (currentLine.isWhitespace()) {
+      currentLine = newLine();
+    }
   }
 
+  Line newLine() => new Line(indentLevel: indentCount, printer: linePrinter);
+
   String toString() {
     var source = new StringBuffer(buffer.toString());
     if (!currentLine.isWhitespace()) {
       source.write(currentLine);
     }
     return source.toString();
   }
 
 }
 
@@ skipping 45 matching lines @@
 
 String getTabs(int n) => n < TABS.length ? TABS[n] : repeat('\t', n);
 
 String repeat(String ch, int times) {
   var sb = new StringBuffer();
   for (var i = 0; i < times; ++i) {
     sb.write(ch);
   }
   return sb.toString();
 }