Make hasNext a getter instead of a method.

lib/utf/utf_core.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.
 
 /**
  * Provide a list of Unicode codepoints for a given string.
  */
 List<int> stringToCodepoints(String str) {
   List<int> codepoints;
   // TODO _is16BitCodeUnit() is used to work around a bug with dart2js
@@ skipping 106 matching lines @@
  */
 List<int> _utf16CodeUnitsToCodepoints(
     List<int> utf16CodeUnits, [int offset = 0, int length,
     int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) {
   _ListRangeIterator source =
       (new _ListRange(utf16CodeUnits, offset, length)).iterator();
   Utf16CodeUnitDecoder decoder = new Utf16CodeUnitDecoder
       .fromListRangeIterator(source, replacementCodepoint);
   List<int> codepoints = new List<int>(source.remaining);
   int i = 0;
-  while (decoder.hasNext()) {
+  while (decoder.hasNext) {
     codepoints[i++] = decoder.next();
   }
   if (i == codepoints.length) {
     return codepoints;
   } else {
     List<int> codepointTrunc = new List<int>(i);
     codepointTrunc.setRange(0, i, codepoints);
     return codepointTrunc;
   }
 }
@@ skipping 13 matching lines @@
       UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) :
       utf16CodeUnitIterator = (new _ListRange(utf16CodeUnits, offset, length))
           .iterator();
 
   Utf16CodeUnitDecoder.fromListRangeIterator(
       _ListRangeIterator this.utf16CodeUnitIterator,
       int this.replacementCodepoint);
 
   Iterator<int> iterator() => this;
 
-  bool hasNext() => utf16CodeUnitIterator.hasNext();
+  bool get hasNext => utf16CodeUnitIterator.hasNext;
 
   int next() {
     int value = utf16CodeUnitIterator.next();
     if (value < 0) {
       if (replacementCodepoint != null) {
         return replacementCodepoint;
       } else {
         throw new ArgumentError(
             "Invalid UTF16 at ${utf16CodeUnitIterator.position}");
       }
     } else if (value < UNICODE_UTF16_RESERVED_LO ||
         (value > UNICODE_UTF16_RESERVED_HI && value <= UNICODE_PLANE_ONE_MAX)) {
       // transfer directly
       return value;
     } else if (value < UNICODE_UTF16_SURROGATE_UNIT_1_BASE &&
-        utf16CodeUnitIterator.hasNext()) {
+        utf16CodeUnitIterator.hasNext) {
       // merge surrogate pair
       int nextValue = utf16CodeUnitIterator.next();
       if (nextValue >= UNICODE_UTF16_SURROGATE_UNIT_1_BASE &&
           nextValue <= UNICODE_UTF16_RESERVED_HI) {
         value = (value - UNICODE_UTF16_SURROGATE_UNIT_0_BASE) << 10;
         value += UNICODE_UTF16_OFFSET +
             (nextValue - UNICODE_UTF16_SURROGATE_UNIT_1_BASE);
         return value;
       } else {
         if (nextValue >= UNICODE_UTF16_SURROGATE_UNIT_0_BASE &&
@@ skipping 46 matching lines @@
 
   int get length => _length;
 }
 
 /**
  * The _ListRangeIterator provides more capabilities than a standard iterator,
  * including the ability to get the current position, count remaining items,
  * and move forward/backward within the iterator.
  */
 abstract class _ListRangeIterator implements Iterator<int> {
-  bool hasNext();
+  bool hasNext;
   int next();
   int get position;
   void backup([by]);
   int get remaining;
   void skip([count]);
 }
 
 class _ListRangeIteratorImpl implements _ListRangeIterator {
   final List<int> _source;
   int _offset;
   final int _end;
 
   _ListRangeIteratorImpl(this._source, this._offset, this._end);
 
-  bool hasNext() => _offset < _end;
+  bool get hasNext => _offset < _end;
 
   int next() => _source[_offset++];
 
   int get position => _offset;
 
   void backup([int by = 1]) {
     _offset -= by;
   }
 
   int get remaining => _end - _offset;
 
   void skip([int count = 1]) {
     _offset += count;
   }
 }