Roll Observatory packages and add a roll script

utf/lib/src/util.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 utf.util;
-
-import 'constants.dart';
-import 'list_range.dart';
-import 'utf_16_code_unit_decoder.dart';
-
-/**
- * Decodes the utf16 codeunits to codepoints.
- */
-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.moveNext()) {
-    codepoints[i++] = decoder.current;
-  }
-  if (i == codepoints.length) {
-    return codepoints;
-  } else {
-    List<int> codepointTrunc = new List<int>(i);
-    codepointTrunc.setRange(0, i, codepoints);
-    return codepointTrunc;
-  }
-}
-
-/**
- * Encode code points as UTF16 code units.
- */
-List<int> codepointsToUtf16CodeUnits(
-    List<int> codepoints,
-    [int offset = 0,
-     int length,
-     int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) {
-
-  ListRange listRange = new ListRange(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++;
-    }
-  }
-
-  List<int> codeUnitsBuffer = new List<int>(encodedLength);
-  int j = 0;
-  for (int value in listRange) {
-    if ((value >= 0 && value < UNICODE_UTF16_RESERVED_LO) ||
-        (value > UNICODE_UTF16_RESERVED_HI && value <= UNICODE_PLANE_ONE_MAX)) {
-      codeUnitsBuffer[j++] = value;
-    } else if (value > UNICODE_PLANE_ONE_MAX &&
-        value <= UNICODE_VALID_RANGE_MAX) {
-      int base = value - UNICODE_UTF16_OFFSET;
-      codeUnitsBuffer[j++] = UNICODE_UTF16_SURROGATE_UNIT_0_BASE +
-          ((base & UNICODE_UTF16_HI_MASK) >> 10);
-      codeUnitsBuffer[j++] = UNICODE_UTF16_SURROGATE_UNIT_1_BASE +
-          (base & UNICODE_UTF16_LO_MASK);
-    } else if (replacementCodepoint != null) {
-      codeUnitsBuffer[j++] = replacementCodepoint;
-    } else {
-      throw new ArgumentError("Invalid encoding");
-    }
-  }
-  return codeUnitsBuffer;
-}