Implement minified MirrorSystem.getName.

dart/sdk/lib/_internal/lib/js_names.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 dart._js_names;
+
+import 'dart:_foreign_helper' show JS;
+
+/// No-op method that is called to inform the compiler that unmangled named
+/// must be preserved.
+preserveNames() {}
+
+/// A map from mangled names to "reflective" names, that is, unmangled names
+/// with some additional information, such as, number of required arguments.
+/// This map is for mangled names used as instance members.
+final Map<String, String> mangledNames =
+    computeMangledNames(JS('', 'init.mangledNames'));
+
+/// A map from "reflective" names to mangled names (the reverse of
+/// [mangledNames]).
+final Map<String, String> reflectiveNames =
+    computeReflectiveNames(mangledNames);
+
+/// A map from mangled names to "reflective" names (see [mangledNames]).  This
+/// map is for globals, that is, static and top-level members.
+final Map<String, String> mangledGlobalNames =
+    computeMangledNames(JS('', 'init.mangledGlobalNames'));
+
+/// A map from "reflective" names to mangled names (the reverse of
+/// [mangledGlobalNames]).
+final Map<String, String> reflectiveGlobalNames =
+    computeReflectiveNames(mangledGlobalNames);
+
+/// [jsMangledNames] is a JavaScript object literal.  The keys are the mangled
+/// names, and the values are the "reflective" names.
+Map<String, String> computeMangledNames(jsMangledNames) {
+  preserveNames();
+  var keys = extractKeys(jsMangledNames);
+  var result = <String, String>{};
+  for (String key in keys) {
+    result[key] = JS('String', '#[#]', jsMangledNames, key);
+  }
+  return result;
+}
+
+Map<String, String> computeReflectiveNames(Map<String, String> map) {
+  preserveNames();
+  var result = <String, String>{};
+  map.forEach((String mangledName, String reflectiveName) {
+    result[reflectiveName] = mangledName;
+  });
+  return result;
+}
+
+List extractKeys(victim) {
+  return JS('List', '''
+(function(victim, hasOwnProperty) {
+  var result = [];
+  for (var key in victim) {
+    if (hasOwnProperty.call(victim, key)) result.push(key);
+  }
+  return result;
+})(#, Object.prototype.hasOwnProperty)''', victim);
+}