dartfmt line wrapping bypass option support.

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;
 
 
-/// DEBUG flag indicating whether to use the experimental line-breaker
-const _USE_LINE_BREAKER = false;
-
 
 class Line {
 
   final tokens = <LineToken>[];
   final bool useTabs;
   final int spacesPerIndent;
   final int indent;
   final LinePrinter printer;
 
   Line({this.indent: 0, this.useTabs: false, this.spacesPerIndent: 2,
@@ skipping 265 matching lines @@
   Line currentLine;
 
   final String lineSeparator;
   int indentCount = 0;
 
   LinePrinter linePrinter;
   LineToken _lastToken;
 
   SourceWriter({this.indentCount: 0, this.lineSeparator: NEW_LINE,
       bool useTabs: false, int spacesPerIndent: 2, int maxLineLength: 80}) {
-    if (_USE_LINE_BREAKER) {
+    if (maxLineLength > -1) {

[Brian Wilkerson, 2014/01/27 20:14:50]

Will the SimpleLineBreaker work if the line length is zero? If not, consider
changing the test to "maxLineLength > 0".

[lukechurch, 2014/01/27 20:39:44]

I agree (+1 seems loaded in this context ;))

Zero should be supported to also disable the line breaker

[pquitslund, 2014/01/27 22:23:37]

Good call.  Done!

[pquitslund, 2014/01/27 22:23:37]

Done.

       linePrinter = new SimpleLineBreaker(maxLineLength, (n) =>
           getIndentString(n, useTabs: useTabs, spacesPerIndent: spacesPerIndent));
     } else {
       linePrinter = new SimpleLinePrinter();
     }
     currentLine = new Line(indent: indentCount, printer: linePrinter);
   }
 
   LineToken get lastToken => _lastToken;
 
@@ skipping 100 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();
 }