Roll Observatory packages and add a roll script

path/lib/src/parsed_path.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 path.parsed_path;
-
-import 'internal_style.dart';
-import 'style.dart';
-
-class ParsedPath {
-  /// The [InternalStyle] that was used to parse this path.
-  InternalStyle style;
-
-  /// The absolute root portion of the path, or `null` if the path is relative.
-  /// On POSIX systems, this will be `null` or "/". On Windows, it can be
-  /// `null`, "//" for a UNC path, or something like "C:\" for paths with drive
-  /// letters.
-  String root;
-
-  /// Whether this path is root-relative.
-  ///
-  /// See [Context.isRootRelative].
-  bool isRootRelative;
-
-  /// The path-separated parts of the path. All but the last will be
-  /// directories.
-  List<String> parts;
-
-  /// The path separators preceding each part.
-  ///
-  /// The first one will be an empty string unless the root requires a separator
-  /// between it and the path. The last one will be an empty string unless the
-  /// path ends with a trailing separator.
-  List<String> separators;
-
-  /// The file extension of the last non-empty part, or "" if it doesn't have
-  /// one.
-  String get extension => _splitExtension()[1];
-
-  /// `true` if this is an absolute path.
-  bool get isAbsolute => root != null;
-
-  factory ParsedPath.parse(String path, InternalStyle style) {
-    // Remove the root prefix, if any.
-    var root = style.getRoot(path);
-    var isRootRelative = style.isRootRelative(path);
-    if (root != null) path = path.substring(root.length);
-
-    // Split the parts on path separators.
-    var parts = <String>[];
-    var separators = <String>[];
-
-    var start = 0;
-
-    if (path.isNotEmpty && style.isSeparator(path.codeUnitAt(0))) {
-      separators.add(path[0]);
-      start = 1;
-    } else {
-      separators.add('');
-    }
-
-    for (var i = start; i < path.length; i++) {
-      if (style.isSeparator(path.codeUnitAt(i))) {
-        parts.add(path.substring(start, i));
-        separators.add(path[i]);
-        start = i + 1;
-      }
-    }
-
-    // Add the final part, if any.
-    if (start < path.length) {
-      parts.add(path.substring(start));
-      separators.add('');
-    }
-
-    return new ParsedPath._(style, root, isRootRelative, parts, separators);
-  }
-
-  ParsedPath._(
-      this.style, this.root, this.isRootRelative, this.parts, this.separators);
-
-  String get basename {
-    var copy = this.clone();
-    copy.removeTrailingSeparators();
-    if (copy.parts.isEmpty) return root == null ? '' : root;
-    return copy.parts.last;
-  }
-
-  String get basenameWithoutExtension => _splitExtension()[0];
-
-  bool get hasTrailingSeparator =>
-      !parts.isEmpty && (parts.last == '' || separators.last != '');
-
-  void removeTrailingSeparators() {
-    while (!parts.isEmpty && parts.last == '') {
-      parts.removeLast();
-      separators.removeLast();
-    }
-    if (separators.length > 0) separators[separators.length - 1] = '';
-  }
-
-  void normalize() {
-    // Handle '.', '..', and empty parts.
-    var leadingDoubles = 0;
-    var newParts = <String>[];
-    for (var part in parts) {
-      if (part == '.' || part == '') {
-        // Do nothing. Ignore it.
-      } else if (part == '..') {
-        // Pop the last part off.
-        if (newParts.length > 0) {
-          newParts.removeLast();
-        } else {
-          // Backed out past the beginning, so preserve the "..".
-          leadingDoubles++;
-        }
-      } else {
-        newParts.add(part);
-      }
-    }
-
-    // A relative path can back out from the start directory.
-    if (!isAbsolute) {
-      newParts.insertAll(0, new List.filled(leadingDoubles, '..'));
-    }
-
-    // If we collapsed down to nothing, do ".".
-    if (newParts.length == 0 && !isAbsolute) {
-      newParts.add('.');
-    }
-
-    // Canonicalize separators.
-    var newSeparators = new List<String>.generate(
-        newParts.length, (_) => style.separator, growable: true);
-    newSeparators.insert(0, isAbsolute &&
-        newParts.length > 0 &&
-        style.needsSeparator(root) ? style.separator : '');
-
-    parts = newParts;
-    separators = newSeparators;
-
-    // Normalize the Windows root if needed.
-    if (root != null && style == Style.windows) {
-      root = root.replaceAll('/', '\\');
-    }
-    removeTrailingSeparators();
-  }
-
-  String toString() {
-    var builder = new StringBuffer();
-    if (root != null) builder.write(root);
-    for (var i = 0; i < parts.length; i++) {
-      builder.write(separators[i]);
-      builder.write(parts[i]);
-    }
-    builder.write(separators.last);
-
-    return builder.toString();
-  }
-
-  /// Splits the last non-empty part of the path into a `[basename, extension`]
-  /// pair.
-  ///
-  /// Returns a two-element list. The first is the name of the file without any
-  /// extension. The second is the extension or "" if it has none.
-  List<String> _splitExtension() {
-    var file = parts.lastWhere((p) => p != '', orElse: () => null);
-
-    if (file == null) return ['', ''];
-    if (file == '..') return ['..', ''];
-
-    var lastDot = file.lastIndexOf('.');
-
-    // If there is no dot, or it's the first character, like '.bashrc', it
-    // doesn't count.
-    if (lastDot <= 0) return [file, ''];
-
-    return [file.substring(0, lastDot), file.substring(lastDot)];
-  }
-
-  ParsedPath clone() => new ParsedPath._(style, root, isRootRelative,
-      new List.from(parts), new List.from(separators));
-}