Move Bidi functions into methods to make the docs look better

pkg/intl/lib/bidi_formatter.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Bidi stands for Bi-directional text.
  * According to [Wikipedia](http://en.wikipedia.org/wiki/Bi-directional_text):
  * Bi-directional text is text containing text in both text directionalities,
  * both right-to-left (RTL) and left-to-right (LTR). It generally involves text
  * containing different types of alphabets, but may also refer to boustrophedon,
@@ skipping 137 matching lines @@
    * do not allow markup, e.g. an 'option' tag.
    * This function does *not* do HTML-escaping regardless of the value of
    * [isHtml]. [isHtml] is used to designate if the text contains HTML (escaped
    * or unescaped).
    */
   String wrapWithUnicode(String text, [bool isHtml=false, bool resetDir=true,
                      TextDirection direction]) {
     if (direction == null) direction = estimateDirection(text, isHtml);
     var result = text;
     if (contextDirection.isDirectionChange(direction)) {
-      result = '''${direction == TextDirection.RTL ? RLE : LRE}$text$PDF''';
+      var marker = direction == TextDirection.RTL ? Bidi.RLE : Bidi.LRE;
+      result = "${marker}$text${Bidi.PDF}";
+
     }
     return result.concat(resetDir? _resetDir(text, direction, isHtml) : '');
   }
 
   /**
    * Estimates the directionality of [text] using the best known
    * general-purpose method (using relative word counts). A
    * TextDirection.UNKNOWN return value indicates completely neutral input.
    * [isHtml] is true if [text] HTML or HTML-escaped.
    */
   TextDirection estimateDirection(String text, [bool isHtml=false]) {
-    return estimateDirectionOfText(text, isHtml); //TODO~!!!
+    return Bidi.estimateDirectionOfText(text, isHtml); //TODO~!!!
   }
 
   /**
    * Returns a unicode BiDi mark matching the surrounding context's [direction]
    * (not necessarily the direction of [text]). The function returns an LRM or
    * RLM if the overall directionality or the exit directionality of [text] is
    * opposite the context directionality. Otherwise
    * return the empty string. [isHtml] is true if [text] is HTML or
    * HTML-escaped.
    */
   String _resetDir(String text, TextDirection direction, bool isHtml) {
     // endsWithRtl and endsWithLtr are called only if needed (short-circuit).
     if ((contextDirection == TextDirection.LTR &&
           (direction == TextDirection.RTL ||
-           endsWithRtl(text, isHtml))) ||
+           Bidi.endsWithRtl(text, isHtml))) ||
         (contextDirection == TextDirection.RTL &&
           (direction == TextDirection.LTR ||
-           endsWithLtr(text, isHtml)))) {
+           Bidi.endsWithLtr(text, isHtml)))) {
       if (contextDirection == TextDirection.LTR) {
-        return LRM;
+        return Bidi.LRM;
       } else {
-        return RLM;
+        return Bidi.RLM;
       }
     } else {
       return '';
     }
   }
 }