Roll Observatory packages and add a roll script

package_config/lib/src/util.dart

-// Copyright (c) 2015, 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.
-
-/// Utility methods used by more than one library in the package.
-library package_config.util;
-
-import "package:charcode/ascii.dart";
-
-// All ASCII characters that are valid in a package name, with space
-// for all the invalid ones (including space).
-const String _validPackageNameCharacters =
-    r"                                 !  $ &'()*+,-. 0123456789 ; =  "
-    r"@ABCDEFGHIJKLMNOPQRSTUVWXYZ    _ abcdefghijklmnopqrstuvwxyz   ~ ";
-
-/// Tests whether something is a valid Dart package name.
-bool isValidPackageName(String string) {
-  return _findInvalidCharacter(string) < 0;
-}
-
-/// Check if a string is a valid package name.
-///
-/// Valid package names contain only characters in [_validPackageNameCharacters]
-/// and must contain at least one non-'.' character.
-///
-/// Returns `-1` if the string is valid.
-/// Otherwise returns the index of the first invalid character,
-/// or `string.length` if the string contains no non-'.' character.
-int _findInvalidCharacter(String string) {
-  // Becomes non-zero if any non-'.' character is encountered.
-  int nonDot = 0;
-  for (int i = 0; i < string.length; i++) {
-    var c = string.codeUnitAt(i);
-    if (c > 0x7f || _validPackageNameCharacters.codeUnitAt(c) <= $space) {
-      return i;
-    }
-    nonDot += c ^ $dot;
-  }
-  if (nonDot == 0) return string.length;
-  return -1;
-}
-
-/// Validate that a Uri is a valid package:URI.
-String checkValidPackageUri(Uri packageUri) {
-  if (packageUri.scheme != "package") {
-    throw new ArgumentError.value(packageUri, "packageUri",
-                                  "Not a package: URI");
-  }
-  if (packageUri.hasAuthority) {
-    throw new ArgumentError.value(packageUri, "packageUri",
-                                  "Package URIs must not have a host part");
-  }
-  if (packageUri.hasQuery) {
-    // A query makes no sense if resolved to a file: URI.
-    throw new ArgumentError.value(packageUri, "packageUri",
-                                  "Package URIs must not have a query part");
-  }
-  if (packageUri.hasFragment) {
-    // We could leave the fragment after the URL when resolving,
-    // but it would be odd if "package:foo/foo.dart#1" and
-    // "package:foo/foo.dart#2" were considered different libraries.
-    // Keep the syntax open in case we ever get multiple libraries in one file.
-    throw new ArgumentError.value(packageUri, "packageUri",
-                                  "Package URIs must not have a fragment part");
-  }
-  if (packageUri.path.startsWith('/')) {
-    throw new ArgumentError.value(packageUri, "packageUri",
-                                  "Package URIs must not start with a '/'");
-  }
-  int firstSlash = packageUri.path.indexOf('/');
-  if (firstSlash == -1) {
-    throw new ArgumentError.value(packageUri, "packageUri",
-        "Package URIs must start with the package name followed by a '/'");
-  }
-  String packageName = packageUri.path.substring(0, firstSlash);
-  int badIndex = _findInvalidCharacter(packageName);
-  if (badIndex >= 0) {
-    if (packageName.isEmpty) {
-      throw new ArgumentError.value(packageUri, "packageUri",
-          "Package names mus be non-empty");
-    }
-    if (badIndex == packageName.length) {
-      throw new ArgumentError.value(packageUri, "packageUri",
-          "Package names must contain at least one non-'.' character");
-    }
-    assert(badIndex < packageName.length);
-    int badCharCode = packageName.codeUnitAt(badIndex);
-    var badChar = "U+" + badCharCode.toRadixString(16).padLeft(4, '0');
-    if (badCharCode >= 0x20 && badCharCode <= 0x7e) {
-      // Printable character.
-      badChar = "'${packageName[badIndex]}' ($badChar)";
-    }
-    throw new ArgumentError.value(packageUri, "packageUri",
-        "Package names must not contain $badChar");
-  }
-  return packageName;
-}