Unify most of our utf8 implementations. This takes the implementation

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.
 
-#library("unicode_core");
+/**
+ * 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 frog/dartc
+  // (http://code.google.com/p/dart/issues/detail?id=1357). Consider
+  // removing after this issue is resolved.
+  if (_is16BitCodeUnit()) {
+    codepoints = _utf16CodeUnitsToCodepoints(str.charCodes());
+  } else {
+    codepoints = str.charCodes();
+  }
+  return codepoints;
+}
+
+/**
+ * Generate a string from the provided Unicode codepoints.
+ */
+String codepointsToString(List<int> codepoints) {
+  // TODO _is16BitCodeUnit() is used to work around a bug with frog/dartc
+  // (http://code.google.com/p/dart/issues/detail?id=1357). Consider
+  // removing after this issue is resolved.
+  if (_is16BitCodeUnit()) {
+    return new String.fromCharCodes(
+        _codepointsToUtf16CodeUnits(codepoints));
+  } else {
+    return new String.fromCharCodes(codepoints);
+  }
+}
 
 /*
  * Test for presence of bug related to the use of UTF-16 code units for
  * Dart compiled to JS.
  */
 bool _test16BitCodeUnit = null;
-// TODO is16BitCodeUnit() is used to work around a bug with frog/dartc
+// TODO _is16BitCodeUnit() is used to work around a bug with frog/dartc
 // (http://code.google.com/p/dart/issues/detail?id=1357). Consider
 // removing after this issue is resolved.
-bool is16BitCodeUnit() {
+bool _is16BitCodeUnit() {
   if (_test16BitCodeUnit == null) {
     _test16BitCodeUnit = (new String.fromCharCodes([0x1D11E])) ==
         (new String.fromCharCodes([0xD11E]));
   }
   return _test16BitCodeUnit;
 }
 
 /**
  * Invalid codepoints or encodings may be substituted with the value U+fffd.
  */
@@ skipping 10 matching lines @@
 final int UNICODE_UTF16_RESERVED_HI = 0xdfff;
 final int UNICODE_UTF16_OFFSET = 0x10000;
 final int UNICODE_UTF16_SURROGATE_UNIT_0_BASE = 0xd800;
 final int UNICODE_UTF16_SURROGATE_UNIT_1_BASE = 0xdc00;
 final int UNICODE_UTF16_HI_MASK = 0xffc00;
 final int UNICODE_UTF16_LO_MASK = 0x3ff;
 
 /**
  * Encode code points as UTF16 code units.
  */
-List<int> codepointsToUtf16CodeUnits(
+List<int> _codepointsToUtf16CodeUnits(
     List<int> codepoints, [int offset = 0, int length,
     int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) {
 
-  ListRange<int> listRange = new ListRange<int>(codepoints, offset, length);
+  _ListRange<int> listRange = new _ListRange<int>(codepoints, offset, length);
   int encodedLength = 0;
   for (int value in listRange) {
     if ((value >= 0 && value < UNICODE_UTF16_RESERVED_LO) ||
         (value > UNICODE_UTF16_RESERVED_HI && value <= UNICODE_PLANE_ONE_MAX)) {
       encodedLength++;
     } else if (value > UNICODE_PLANE_ONE_MAX &&
         value <= UNICODE_VALID_RANGE_MAX) {
       encodedLength += 2;
     } else {
       encodedLength++;
@@ skipping 18 matching lines @@
     } else {
       throw new IllegalArgumentException("Invalid encoding");
     }
   }
   return codeUnitsBuffer;
 }
 
 /**
  * Decodes the utf16 codeunits to codepoints.
  */
-List<int> utf16CodeUnitsToCodepoints(
+List<int> _utf16CodeUnitsToCodepoints(
     List<int> utf16CodeUnits, [int offset = 0, int length,
     int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) {
-  ListRangeIterator<int> source =
-      (new ListRange<int>(utf16CodeUnits, offset, length)).iterator();
+  _ListRangeIterator<int> source =
+      (new _ListRange<int>(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()) {
     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;
   }
 }
 
 /**
  * An Iterator<int> of codepoints built on an Iterator of UTF-16 code units.
  * The parameters can override the default Unicode replacement character. Set
  * the replacementCharacter to null to throw an IllegalArgumentException
  * rather than replace the bad value.
  */
 class Utf16CodeUnitDecoder implements Iterator<int> {
-  final ListRangeIterator<int> utf16CodeUnitIterator;
+  final _ListRangeIterator<int> utf16CodeUnitIterator;
   final int replacementCodepoint;
 
   Utf16CodeUnitDecoder(List<int> utf16CodeUnits, [int offset = 0, int length,
       int this.replacementCodepoint =
       UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) :
-      utf16CodeUnitIterator = (new ListRange(utf16CodeUnits, offset, length))
+      utf16CodeUnitIterator = (new _ListRange(utf16CodeUnits, offset, length))
           .iterator();
 
   Utf16CodeUnitDecoder.fromListRangeIterator(
-      ListRangeIterator<int> this.utf16CodeUnitIterator,
+      _ListRangeIterator<int> this.utf16CodeUnitIterator,
       int this.replacementCodepoint);
 
   Iterator<int> iterator() => this;
 
   bool hasNext() => utf16CodeUnitIterator.hasNext();
 
   int next() {
     int value = utf16CodeUnitIterator.next();
     if (value < 0) {
       if (replacementCodepoint != null) {
@@ skipping 31 matching lines @@
     } else if (replacementCodepoint != null) {
       return replacementCodepoint;
     } else {
       throw new IllegalArgumentException(
           "Invalid UTF16 at ${utf16CodeUnitIterator.position}");
     }
   }
 }
 
 /**
- * ListRange in an internal type used to create a lightweight Interable on a
+ * _ListRange in an internal type used to create a lightweight Interable on a
  * range within a source list. DO NOT MODIFY the underlying list while
  * iterating over it. The results of doing so are undefined.
  */
-class ListRange<T> implements Iterable<T> {
+class _ListRange<T> implements Iterable<T> {
   final List<T> _source;
   final int _offset;
   final int _length;
 
-  ListRange(List<T> source, [int offset = 0, int length]) :
+  _ListRange(List<T> source, [int offset = 0, int length]) :
       this._source = source, this._offset = offset,
       this._length = (length == null ? source.length - offset : length) {
     if (_offset < 0 || _offset > _source.length) {
       throw new IndexOutOfRangeException("offset out of range (< 0)");
     }
     if (_length != null && (_length < 0)) {
       throw new IndexOutOfRangeException("length out of range (< 0)");
     }
     if (_length + _offset > _source.length) {
       throw new IndexOutOfRangeException("offset + length > source.length");
     }
   }
 
-  ListRangeIterator<T> iterator() =>
-      new ListRangeIteratorImpl(_source, _offset, _offset + _length);
+  _ListRangeIterator<T> iterator() =>
+      new _ListRangeIteratorImpl(_source, _offset, _offset + _length);
 
   int get length() => _length;
 }
 
 /**
- * The ListRangeIterator provides more capabilities than a standard iterator,
+ * 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.
  */
-interface ListRangeIterator<T> extends Iterator<T> {
+interface _ListRangeIterator<T> extends Iterator<T> {
   bool hasNext();
   T next();
   int get position();
   void backup([int by]);
   int get remaining();
   void skip([int count]);
 }
 
-class ListRangeIteratorImpl<T> implements ListRangeIterator<T> {
+class _ListRangeIteratorImpl<T> implements _ListRangeIterator<T> {
   final List<T> _source;
   int _offset;
   final int _end;
 
-  ListRangeIteratorImpl(List<T> source, int offset, int end) :
+  _ListRangeIteratorImpl(List<T> source, int offset, int end) :
       _source = source, _offset = offset, _end = end;
 
   bool hasNext() => _offset < _end;
   T 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;
   }
 }
+