fixes #40, extension methods for primitive types

test/generated_sdk/lib/_internal/compiler/js_lib/native_helper.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.
 
 part of _js_helper;
 
 
 // TODO(ngeoffray): stop using this method once our optimizers can
 // change str1.contains(str2) into str1.indexOf(str2) != -1.
 bool contains(String userAgent, String name) {
@@ skipping 22 matching lines @@
 
 void propertySet(var object, String property, var value) {
   JS('var', '#[#] = #', object, property, value);
 }
 
 getPropertyFromPrototype(var object, String name) {
   return JS('var', 'Object.getPrototypeOf(#)[#]', object, name);
 }
 
 /**
- * Returns a String tag identifying the type of the native object, or `null`.
- * The tag is not the name of the type, but usually the name of the JavaScript
- * constructor function.  Initialized by [initHooks].
- */
-Function getTagFunction;
-
-/**
- * If a lookup via [getTagFunction] on an object [object] that has [tag] fails,
- * this function is called to provide an alternate tag.  This allows us to fail
- * gracefully if we can make a good guess, for example, when browsers add novel
- * kinds of HTMLElement that we have never heard of.  Initialized by
- * [initHooks].
- */
-Function alternateTagFunction;
-
-/**
- * Returns the prototype for the JavaScript constructor named by an input tag.
- * Returns `null` if there is no such constructor, or if pre-patching of the
- * constructor is to be avoided.  Initialized by [initHooks].
- */
-Function prototypeForTagFunction;
-
-
-String toStringForNativeObject(var obj) {
-  // TODO(sra): Is this code dead?
-  // [getTagFunction] might be uninitialized, but in usual usage, toString has
-  // been called via an interceptor and initialized it.
-  String name = getTagFunction == null
-      ? '<Unknown>'
-      : JS('String', '#', getTagFunction(obj));
-  return 'Instance of $name';
-}
-
-int hashCodeForNativeObject(object) => Primitives.objectHashCode(object);
-
-/**
  * Sets a JavaScript property on an object.
  */
 void defineProperty(var obj, String property, var value) {
   JS('void',
       'Object.defineProperty(#, #, '
           '{value: #, enumerable: false, writable: true, configurable: true})',
       obj,
       property,
       value);
 }
-
-
-// Is [obj] an instance of a Dart-defined class?
-bool isDartObject(obj) {
-  // Some of the extra parens here are necessary.
-  return JS('bool', '((#) instanceof (#))', obj, JS_DART_OBJECT_CONSTRUCTOR());
-}
-
-/**
- * A JavaScript object mapping tags to the constructors of interceptors.
- * This is a JavaScript object with no prototype.
- *
- * Example: 'HTMLImageElement' maps to the ImageElement class constructor.
- */
-get interceptorsByTag => JS_EMBEDDED_GLOBAL('=Object', INTERCEPTORS_BY_TAG);
-
-/**
- * A JavaScript object mapping tags to `true` or `false`.
- *
- * Example: 'HTMLImageElement' maps to `true` since, as there are no subclasses
- * of ImageElement, it is a leaf class in the native class hierarchy.
- */
-get leafTags => JS_EMBEDDED_GLOBAL('=Object', LEAF_TAGS);
-
-String findDispatchTagForInterceptorClass(interceptorClassConstructor) {
-  return JS('', r'#.#',
-            interceptorClassConstructor, NATIVE_SUPERCLASS_TAG_NAME);
-}
-
-/**
- * Cache of dispatch records for instances.  This is a JavaScript object used as
- * a map.  Keys are instance tags, e.g. "!SomeThing".  The cache permits the
- * sharing of one dispatch record between multiple instances.
- */
-var dispatchRecordsForInstanceTags;
-
-/**
- * Cache of interceptors indexed by uncacheable tags, e.g. "~SomeThing".
- * This is a JavaScript object used as a map.
- */
-var interceptorsForUncacheableTags;
-
-
-lookupInterceptor(String tag) {
-  return propertyGet(interceptorsByTag, tag);
-}
-
-
-// Dispatch tag marks are optional prefixes for a dispatch tag that direct how
-// the interceptor for the tag may be cached.
-
-/// No caching permitted.
-const UNCACHED_MARK = '~';
-
-/// Dispatch record must be cached per instance
-const INSTANCE_CACHED_MARK = '!';
-
-/// Dispatch record is cached on immediate prototype.
-const LEAF_MARK = '-';
-
-/// Dispatch record is cached on immediate prototype with a prototype
-/// verification to prevent the interceptor being associated with a subclass
-/// before a dispatch record is cached on the subclass.
-const INTERIOR_MARK = '+';
-
-/// A 'discriminator' function is to be used. TBD.
-const DISCRIMINATED_MARK = '*';
-
-
-/**
- * Returns the interceptor for a native object, or returns `null` if not found.
- *
- * A dispatch record is cached according to the specification of the dispatch
- * tag for [obj].
- */
-lookupAndCacheInterceptor(obj) {
-  assert(!isDartObject(obj));
-  String tag = getTagFunction(obj);
-
-  // Fast path for instance (and uncached) tags because the lookup is repeated
-  // for each instance (or getInterceptor call).
-  var record = propertyGet(dispatchRecordsForInstanceTags, tag);
-  if (record != null) return patchInstance(obj, record);
-  var interceptor = propertyGet(interceptorsForUncacheableTags, tag);
-  if (interceptor != null) return interceptor;
-
-  // This lookup works for derived dispatch tags because we add them all in
-  // [initNativeDispatch].
-  var interceptorClass = lookupInterceptor(tag);
-  if (interceptorClass == null) {
-    tag = alternateTagFunction(obj, tag);
-    if (tag != null) {
-      // Fast path for instance and uncached tags again.
-      record = propertyGet(dispatchRecordsForInstanceTags, tag);
-      if (record != null) return patchInstance(obj, record);
-      interceptor = propertyGet(interceptorsForUncacheableTags, tag);
-      if (interceptor != null) return interceptor;
-
-      interceptorClass = lookupInterceptor(tag);
-    }
-  }
-
-  if (interceptorClass == null) {
-    // This object is not known to Dart.  There could be several reasons for
-    // that, including (but not limited to):
-    //
-    // * A bug in native code (hopefully this is caught during development).
-    // * An unknown DOM object encountered.
-    // * JavaScript code running in an unexpected context.  For example, on
-    //   node.js.
-    return null;
-  }
-
-  interceptor = JS('', '#.prototype', interceptorClass);
-
-  var mark = JS('String|Null', '#[0]', tag);
-
-  if (mark == INSTANCE_CACHED_MARK) {
-    record = makeLeafDispatchRecord(interceptor);
-    propertySet(dispatchRecordsForInstanceTags, tag, record);
-    return patchInstance(obj, record);
-  }
-
-  if (mark == UNCACHED_MARK) {
-    propertySet(interceptorsForUncacheableTags, tag, interceptor);
-    return interceptor;
-  }
-
-  if (mark == LEAF_MARK) {
-    return patchProto(obj, makeLeafDispatchRecord(interceptor));
-  }
-
-  if (mark == INTERIOR_MARK) {
-    return patchInteriorProto(obj, interceptor);
-  }
-
-  if (mark == DISCRIMINATED_MARK) {
-    // TODO(sra): Use discriminator of tag.
-    throw new UnimplementedError(tag);
-  }
-
-  // [tag] was not explicitly an interior or leaf tag, so
-  var isLeaf = JS('bool', '(#[#]) === true', leafTags, tag);
-  if (isLeaf) {
-    return patchProto(obj, makeLeafDispatchRecord(interceptor));
-  } else {
-    return patchInteriorProto(obj, interceptor);
-  }
-}
-
-patchInstance(obj, record) {
-  setDispatchProperty(obj, record);
-  return dispatchRecordInterceptor(record);
-}
-
-patchProto(obj, record) {
-  setDispatchProperty(JS('', 'Object.getPrototypeOf(#)', obj), record);
-  return dispatchRecordInterceptor(record);
-}
-
-patchInteriorProto(obj, interceptor) {
-  var proto = JS('', 'Object.getPrototypeOf(#)', obj);
-  var record = makeDispatchRecord(interceptor, proto, null, null);
-  setDispatchProperty(proto, record);
-  return interceptor;
-}
-
-
-makeLeafDispatchRecord(interceptor) {
-  var fieldName = JS_IS_INDEXABLE_FIELD_NAME();
-  bool indexability = JS('bool', r'!!#[#]', interceptor, fieldName);
-  return makeDispatchRecord(interceptor, false, null, indexability);
-}
-
-makeDefaultDispatchRecord(tag, interceptorClass, proto) {
-  var interceptor = JS('', '#.prototype', interceptorClass);
-  var isLeaf = JS('bool', '(#[#]) === true', leafTags, tag);
-  if (isLeaf) {
-    return makeLeafDispatchRecord(interceptor);
-  } else {
-    return makeDispatchRecord(interceptor, proto, null, null);
-  }
-}
-
-/**
- * [proto] should have no shadowing prototypes that are not also assigned a
- * dispatch rescord.
- */
-setNativeSubclassDispatchRecord(proto, interceptor) {
-  setDispatchProperty(proto, makeLeafDispatchRecord(interceptor));
-}
-
-String constructorNameFallback(object) {
-  return JS('String', '#(#)', _constructorNameFallback, object);
-}
-
-
-var initNativeDispatchFlag;  // null or true
-
-void initNativeDispatch() {
-  if (true == initNativeDispatchFlag) return;
-  initNativeDispatchFlag = true;
-  initNativeDispatchContinue();
-}
-
-void initNativeDispatchContinue() {
-
-  dispatchRecordsForInstanceTags = JS('', 'Object.create(null)');
-  interceptorsForUncacheableTags = JS('', 'Object.create(null)');
-
-  initHooks();
-
-  // Try to pro-actively patch prototypes of DOM objects.  For each of our known
-  // tags `TAG`, if `window.TAG` is a (constructor) function, set the dispatch
-  // property if the function's prototype to a dispatch record.
-  var map = interceptorsByTag;
-  var tags = JS('JSMutableArray', 'Object.getOwnPropertyNames(#)', map);
-
-  if (JS('bool', 'typeof window != "undefined"')) {
-    var context = JS('=Object', 'window');
-    var fun = JS('=Object', 'function () {}');
-    for (int i = 0; i < tags.length; i++) {
-      var tag = tags[i];
-      var proto = prototypeForTagFunction(tag);
-      if (proto != null) {
-        var interceptorClass = JS('', '#[#]', map, tag);
-        var record = makeDefaultDispatchRecord(tag, interceptorClass, proto);
-        if (record != null) {
-          setDispatchProperty(proto, record);
-          // Ensure the modified prototype is still fast by assigning it to
-          // the prototype property of a function object.
-          JS('', '#.prototype = #', fun, proto);
-        }
-      }
-    }
-  }
-
-  // [interceptorsByTag] maps 'plain' dispatch tags.  Add all the derived
-  // dispatch tags to simplify lookup of derived tags.
-  for (int i = 0; i < tags.length; i++) {
-    var tag = JS('String', '#[#]', tags, i);
-    if (JS('bool', '/^[A-Za-z_]/.test(#)', tag)) {
-      var interceptorClass = propertyGet(map, tag);
-      propertySet(map, INSTANCE_CACHED_MARK + tag, interceptorClass);
-      propertySet(map, UNCACHED_MARK + tag, interceptorClass);
-      propertySet(map, LEAF_MARK + tag, interceptorClass);
-      propertySet(map, INTERIOR_MARK + tag, interceptorClass);
-      propertySet(map, DISCRIMINATED_MARK + tag, interceptorClass);
-    }
-  }
-}
-
-
-/**
- * Initializes [getTagFunction] and [alternateTagFunction].
- *
- * These functions are 'hook functions', collectively 'hooks'.  They initialized
- * by applying a series of hooks transformers.  Built-in hooks transformers deal
- * with various known browser behaviours.
- *
- * Each hook tranformer takes a 'hooks' input which is a JavaScript object
- * containing the hook functions, and returns the same or a new object with
- * replacements.  The replacements can wrap the originals to provide alternate
- * or modified behaviour.
- *
- *     { getTag: function(obj) {...},
- *       getUnknownTag: function(obj, tag) {...},
- *       prototypeForTag: function(tag) {...},
- *       discriminator: function(tag) {...},
- *      }
- *
- * * getTag(obj) returns the dispatch tag, or `null`.
- * * getUnknownTag(obj, tag) returns a tag when [getTag] fails.
- * * prototypeForTag(tag) returns the prototype of the constructor for tag,
- *   or `null` if not available or prepatching is undesirable.
- * * discriminator(tag) returns a function TBD.
- *
- * The web site can adapt a dart2js application by loading code ahead of the
- * dart2js application that defines hook transformers to be after the built in
- * ones.  Code defining a transformer HT should use the following pattern to
- * ensure multiple transformers can be composed:
- *
- *     (dartNativeDispatchHooksTransformer =
- *      window.dartNativeDispatchHooksTransformer || []).push(HT);
- *
- *
- * TODO: Implement and describe dispatch tags and their caching methods.
- */
-void initHooks() {
-  // The initial simple hooks:
-  var hooks = JS('', '#()', _baseHooks);
-
-  // Customize for browsers where `object.constructor.name` fails:
-  var _fallbackConstructorHooksTransformer =
-      JS('', '#(#)', _fallbackConstructorHooksTransformerGenerator,
-          _constructorNameFallback);
-  hooks = applyHooksTransformer(_fallbackConstructorHooksTransformer, hooks);
-
-  // Customize for browsers:
-  hooks = applyHooksTransformer(_firefoxHooksTransformer, hooks);
-  hooks = applyHooksTransformer(_ieHooksTransformer, hooks);
-  hooks = applyHooksTransformer(_operaHooksTransformer, hooks);
-  hooks = applyHooksTransformer(_safariHooksTransformer, hooks);
-
-  hooks = applyHooksTransformer(_fixDocumentHooksTransformer, hooks);
-
-  // TODO(sra): Update ShadowDOM polyfil to use
-  // [dartNativeDispatchHooksTransformer] and remove this hook.
-  hooks = applyHooksTransformer(_dartExperimentalFixupGetTagHooksTransformer,
-      hooks);
-
-  // Apply global hooks.
-  //
-  // If defined, dartNativeDispatchHookdTransformer should be a single function
-  // of a JavaScript Array of functions.
-
-  if (JS('bool', 'typeof dartNativeDispatchHooksTransformer != "undefined"')) {
-    var transformers = JS('', 'dartNativeDispatchHooksTransformer');
-    if (JS('bool', 'typeof # == "function"', transformers)) {
-      transformers = [transformers];
-    }
-    if (JS('bool', '#.constructor == Array', transformers)) {
-      for (int i = 0; i < JS('int', '#.length', transformers); i++) {
-        var transformer = JS('', '#[#]', transformers, i);
-        if (JS('bool', 'typeof # == "function"', transformer)) {
-          hooks = applyHooksTransformer(transformer, hooks);
-        }
-      }
-    }
-  }
-
-  var getTag = JS('', '#.getTag', hooks);
-  var getUnknownTag = JS('', '#.getUnknownTag', hooks);
-  var prototypeForTag = JS('', '#.prototypeForTag', hooks);
-
-  getTagFunction = (o) => JS('String|Null', '#(#)', getTag, o);
-  alternateTagFunction =
-      (o, String tag) => JS('String|Null', '#(#, #)', getUnknownTag, o, tag);
-  prototypeForTagFunction =
-      (String tag) => JS('', '#(#)', prototypeForTag, tag);
-}
-
-applyHooksTransformer(transformer, hooks) {
-  var newHooks = JS('=Object|Null', '#(#)', transformer, hooks);
-  return JS('', '# || #', newHooks, hooks);
-}
-
-// JavaScript code fragments.
-//
-// This is a temporary place for the JavaScript code.
-//
-// TODO(sra): These code fragments are not minified.  They could be generated by
-// the code emitter, or JS_CONST could be improved to parse entire functions and
-// take care of the minification.
-
-const _baseHooks = const JS_CONST(r'''
-function() {
-  function typeNameInChrome(o) {
-    var constructor = o.constructor;
-    if (constructor) {
-      var name = constructor.name;
-      if (name) return name;
-    }
-    var s = Object.prototype.toString.call(o);
-    return s.substring(8, s.length - 1);
-  }
-  function getUnknownTag(object, tag) {
-    // This code really belongs in [getUnknownTagGenericBrowser] but having it
-    // here allows [getUnknownTag] to be tested on d8.
-    if (/^HTML[A-Z].*Element$/.test(tag)) {
-      // Check that it is not a simple JavaScript object.
-      var name = Object.prototype.toString.call(object);
-      if (name == "[object Object]") return null;
-      return "HTMLElement";
-    }
-  }
-  function getUnknownTagGenericBrowser(object, tag) {
-    if (self.HTMLElement && object instanceof HTMLElement) return "HTMLElement";
-    return getUnknownTag(object, tag);
-  }
-  function prototypeForTag(tag) {
-    if (typeof window == "undefined") return null;
-    if (typeof window[tag] == "undefined") return null;
-    var constructor = window[tag];
-    if (typeof constructor != "function") return null;
-    return constructor.prototype;
-  }
-  function discriminator(tag) { return null; }
-
-  var isBrowser = typeof navigator == "object";
-
-  return {
-    getTag: typeNameInChrome,
-    getUnknownTag: isBrowser ? getUnknownTagGenericBrowser : getUnknownTag,
-    prototypeForTag: prototypeForTag,
-    discriminator: discriminator };
-}''');
-
-
-/**
- * Returns the name of the constructor function for browsers where
- * `object.constructor.name` is not reliable.
- *
- * This function is split out of [_fallbackConstructorHooksTransformerGenerator]
- * as it is called from both the dispatch hooks and via
- * [constructorNameFallback] from objectToString.
- */
-const _constructorNameFallback = const JS_CONST(r'''
-function getTagFallback(o) {
-  var constructor = o.constructor;
-  if (typeof constructor == "function") {
-    var name = constructor.name;
-    // If the name is a non-empty string, we use that as the type name of this
-    // object.  There are various cases where that does not work, so we have to
-    // detect them and fall through to the toString() based implementation.
-
-    if (typeof name == "string" &&
-
-        // Sometimes the string is empty.  This test also catches minified
-        // shadow dom polyfil wrapper for Window on Firefox where the faked
-        // constructor name does not 'stick'.  The shortest real DOM object
-        // names have three characters (e.g. URL, CSS).
-        name.length > 2 &&
-
-        // On Firefox we often get "Object" as the constructor name, even for
-        // more specialized DOM objects.
-        name !== "Object" &&
-
-        // This can happen in Opera.
-        name !== "Function.prototype") {
-      return name;
-    }
-  }
-  var s = Object.prototype.toString.call(o);
-  return s.substring(8, s.length - 1);
-}''');
-
-
-const _fallbackConstructorHooksTransformerGenerator = const JS_CONST(r'''
-function(getTagFallback) {
-  return function(hooks) {
-    // If we are not in a browser, assume we are in d8.
-    // TODO(sra): Recognize jsshell.
-    if (typeof navigator != "object") return hooks;
-
-    var ua = navigator.userAgent;
-    // TODO(antonm): remove a reference to DumpRenderTree.
-    if (ua.indexOf("DumpRenderTree") >= 0) return hooks;
-    if (ua.indexOf("Chrome") >= 0) {
-      // Confirm constructor name is usable for dispatch.
-      function confirm(p) {
-        return typeof window == "object" && window[p] && window[p].name == p;
-      }
-      if (confirm("Window") && confirm("HTMLElement")) return hooks;
-    }
-
-    hooks.getTag = getTagFallback;
-  };
-}''');
-
-
-const _ieHooksTransformer = const JS_CONST(r'''
-function(hooks) {
-  var userAgent = typeof navigator == "object" ? navigator.userAgent : "";
-  if (userAgent.indexOf("Trident/") == -1) return hooks;
-
-  var getTag = hooks.getTag;
-
-  var quickMap = {
-    "BeforeUnloadEvent": "Event",
-    "DataTransfer": "Clipboard",
-    "HTMLDDElement": "HTMLElement",
-    "HTMLDTElement": "HTMLElement",
-    "HTMLPhraseElement": "HTMLElement",
-    "Position": "Geoposition"
-  };
-
-  function getTagIE(o) {
-    var tag = getTag(o);
-    var newTag = quickMap[tag];
-    if (newTag) return newTag;
-    // Patches for types which report themselves as Objects.
-    if (tag == "Object") {
-      if (window.DataView && (o instanceof window.DataView)) return "DataView";
-    }
-    return tag;
-  }
-
-  function prototypeForTagIE(tag) {
-    var constructor = window[tag];
-    if (constructor == null) return null;
-    return constructor.prototype;
-  }
-
-  hooks.getTag = getTagIE;
-  hooks.prototypeForTag = prototypeForTagIE;
-}''');
-
-const _fixDocumentHooksTransformer = const JS_CONST(r'''
-function(hooks) {
-  var getTag = hooks.getTag;
-  var prototypeForTag = hooks.prototypeForTag;
-  function getTagFixed(o) {
-    var tag = getTag(o);
-    if (tag == "Document") {
-      // Some browsers and the polymer polyfill call both HTML and XML documents
-      // "Document", so we check for the xmlVersion property, which is the empty
-      // string on HTML documents. Since both dart:html classes Document and
-      // HtmlDocument share the same type, we must patch the instances and not
-      // the prototype.
-      if (!!o.xmlVersion) return "!Document";
-      return "!HTMLDocument";
-    }
-    return tag;
-  }
-
-  function prototypeForTagFixed(tag) {
-    if (tag == "Document") return null;  // Do not pre-patch Document.
-    return prototypeForTag(tag);
-  }
-
-  hooks.getTag = getTagFixed;
-  hooks.prototypeForTag = prototypeForTagFixed;
-}''');
-
-const _firefoxHooksTransformer = const JS_CONST(r'''
-function(hooks) {
-  var userAgent = typeof navigator == "object" ? navigator.userAgent : "";
-  if (userAgent.indexOf("Firefox") == -1) return hooks;
-
-  var getTag = hooks.getTag;
-
-  var quickMap = {
-    "BeforeUnloadEvent": "Event",
-    "DataTransfer": "Clipboard",
-    "GeoGeolocation": "Geolocation",
-    "Location": "!Location",               // Fixes issue 18151
-    "WorkerMessageEvent": "MessageEvent",
-    "XMLDocument": "!Document"};
-
-  function getTagFirefox(o) {
-    var tag = getTag(o);
-    return quickMap[tag] || tag;
-  }
-
-  hooks.getTag = getTagFirefox;
-}''');
-
-
-const _operaHooksTransformer = const JS_CONST(r'''
-function(hooks) { return hooks; }
-''');
-
-
-const _safariHooksTransformer = const JS_CONST(r'''
-function(hooks) { return hooks; }
-''');
-
-
-const _dartExperimentalFixupGetTagHooksTransformer = const JS_CONST(r'''
-function(hooks) {
-  if (typeof dartExperimentalFixupGetTag != "function") return hooks;
-  hooks.getTag = dartExperimentalFixupGetTag(hooks.getTag);
-}''');