Fix precedence of ternary operators in polymer expressions

pkg/polymer_expressions/lib/parser.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 polymer_expressions.parser;
 
 import 'tokenizer.dart';
 import 'expression.dart';
 
 const _UNARY_OPERATORS = const ['+', '-', '!'];
@@ skipping 48 matching lines @@
           left = _astFactory.index(left, indexExpr);
         } else {
           break;
         }
       } else if (_token.kind == DOT_TOKEN) {
         _advance();
         var right = _parseUnary();
         left = _makeInvokeOrGetter(left, right);
       } else if (_token.kind == KEYWORD_TOKEN && _token.value == 'in') {
         left = _parseComprehension(left);
-      } else if (_token.kind == OPERATOR_TOKEN && _token.value == '?') {
-        left = _parseTernary(left);
       } else if (_token.kind == OPERATOR_TOKEN
           && _token.precedence >= precedence) {
-        left = _parseBinary(left);
+        left = _token.value == '?' ? _parseTernary(left) : _parseBinary(left);
       } else {
         break;
       }
     }
     return left;
   }
 
   // invoke or getter
   Expression _makeInvokeOrGetter(left, right) {
     if (right is Identifier) {
@@ skipping 210 matching lines @@
     return value;
   }
 
   Literal<double> _parseDecimal([String prefix = '']) {
     var value = _astFactory.literal(double.parse('$prefix${_token.value}'));
     _advance();
     return value;
   }
 
 }