Attempt to re-commit Dartdoc exports.

sdk/lib/_internal/dartdoc/lib/src/dartdoc/utils.dart

Index: sdk/lib/_internal/dartdoc/lib/src/dartdoc/utils.dart
diff --git a/sdk/lib/_internal/dartdoc/lib/src/dartdoc/utils.dart b/sdk/lib/_internal/dartdoc/lib/src/dartdoc/utils.dart
index 470c9f2046c7157189b4426b4631088717cce672..02b7de7db648e0c9f37d85aae61b03361c4913ed 100644
--- a/sdk/lib/_internal/dartdoc/lib/src/dartdoc/utils.dart
+++ b/sdk/lib/_internal/dartdoc/lib/src/dartdoc/utils.dart
@@ -2,9 +2,18 @@
 // 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.
 
-part of dartdoc;
-
 // Generic utility functions.
+library utils;
+
+import 'dart:io';
+import 'dart:uri';
+import 'dart:math' as math;
+
+import 'package:pathos/path.dart' as pathos;
+
+import '../../../../compiler/implementation/mirrors/mirrors.dart';
+
+import '../export_map.dart';
 
 /** Turns [name] into something that's safe to use as a file name. */
 String sanitize(String name) => name.replaceAll(':', '_').replaceAll('/', '_');
@@ -40,7 +49,7 @@ String repeat(String text, int count, {String separator}) {
 /** Removes up to [indentation] leading whitespace characters from [text]. */
 String unindent(String text, int indentation) {
   var start;
-  for (start = 0; start < min(indentation, text.length); start++) {
+  for (start = 0; start < math.min(indentation, text.length); start++) {
     // Stop if we hit a non-whitespace character.
     if (text[start] != ' ') break;
   }
@@ -77,3 +86,76 @@ void writeString(File file, String text) {
   randomAccessFile.writeStringSync(text);
   randomAccessFile.closeSync();
 }
+
+/**
+ * Converts [uri], which should come from a Dart import or export, to a local
+ * filesystem path. [basePath] is the base directory to use when converting
+ * relative URIs; without it, relative URIs will not be converted. [packageRoot]
+ * is the `packages` directory to use when converting `package:` URIs; without
+ * it, `package:` URIs will not be converted.
+ *
+ * If a URI cannot be converted, this will return `null`.
+ */
+String importUriToPath(Uri uri, {String basePath, String packageRoot}) {
+  if (uri.scheme == 'file') return fileUriToPath(uri);
+
+  if (basePath != null && uri.scheme == '') {
+    return pathos.normalize(pathos.absolute(pathos.join(basePath, uri.path)));
+  }
+
+  if (packageRoot != null && uri.scheme == 'package') {
+    return pathos.normalize(pathos.absolute(
+        pathos.join(packageRoot, uri.path)));
+  }
+
+  // Ignore unsupported schemes.
+  return null;
+}
+
+/** Converts a `file:` [Uri] to a local path string. */
+String fileUriToPath(Uri uri) {
+  if (uri.scheme != 'file') {
+    throw new ArgumentError("Uri $uri must have scheme 'file:'.");
+  }
+  if (Platform.operatingSystem != 'windows') return pathos.normalize(uri.path);
+  return pathos.normalize(uri.path.replaceFirst("/", "").replaceAll("/", "\\"));
+}
+
+/** Converts a local path string to a `file:` [Uri]. */
+Uri pathToFileUri(String path) {
+  path = pathos.absolute(path);
+  if (Platform.operatingSystem != 'windows') {
+    return Uri.parse('file://$path');
+  } else {
+    return Uri.parse('file:///${path.replaceAll("\\", "/")}');
+  }
+}
+
+/**
+ * If [map] contains an [Export] under [key], this merges that with [export].
+ * Otherwise, it sets [key] to [export].
+ */
+void addOrMergeExport(Map<String, Export> map, String key, Export export) {
+  if (map.containsKey(key)) {
+    map[key] = map[key].merge(export);
+  } else {
+    map[key] = export;
+  }
+}
+
+/// A pair of values.
+class Pair<E, F> {
+  E first;
+  F last;
+
+  Pair(this.first, this.last);
+
+  String toString() => '($first, $last)';
+
+  bool operator==(other) {
+    if (other is! Pair) return false;
+    return other.first == first && other.last == last;
+  }
+
+  int get hashCode => first.hashCode ^ last.hashCode;
+}