a === b -> identical(a, b)

sdk/lib/io/string_stream.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.
 
 // Interface for decoders decoding binary data into string data. The
 // decoder keeps track of line breaks during decoding.
 abstract class _StringDecoder {
   // Add more binary data to be decoded. The ownership of the buffer
   // is transfered to the decoder and the caller most not modify it any more.
   int write(List<int> buffer);
@@ skipping 406 matching lines @@
     _input.onError = callback;
     _decoder.onError = (e) {
       _clientCloseHandler = null;
       _input.close();
       callback(e);
     };
   }
 
   void _onData() {
     _readData();
-    if (!_decoder.isEmpty && _clientDataHandler !== null) {
+    if (!_decoder.isEmpty && _clientDataHandler != null) {
       _clientDataHandler();
     }
-    if (_decoder.lineBreaks > 0 && _clientLineHandler !== null) {
+    if (_decoder.lineBreaks > 0 && _clientLineHandler != null) {
       _clientLineHandler();
     }
     _checkScheduleCallback();
     _checkInstallDataHandler();
   }
 
   void _onClosed() {
     _inputClosed = true;
     if (_decoder.isEmpty && _clientCloseHandler !=  null) {
       _clientCloseHandler();
     } else {
       _checkScheduleCallback();
     }
   }
 
   void _readData() {
     List<int> data = _input.read();
-    if (data !== null) {
+    if (data != null) {
       _decoder.write(data);
     }
   }
 
   void _checkInstallDataHandler() {
     if (_inputClosed ||
-        (_clientDataHandler === null && _clientLineHandler === null)) {
+        (_clientDataHandler == null && _clientLineHandler == null)) {
       _input.onData = null;
-    } else if (_clientDataHandler !== null) {
+    } else if (_clientDataHandler != null) {
       if (_decoder.isEmpty) {
         _input.onData = _onData;
       } else {
         _input.onData = null;
       }
     } else {
-      assert(_clientLineHandler !== null);
+      assert(_clientLineHandler != null);
       if (_decoder.lineBreaks == 0) {
         _input.onData = _onData;
       } else {
         _input.onData = null;
       }
     }
   }
 
   // TODO(sgjesse): Find a better way of scheduling callbacks from
   // the event loop.
   void _checkScheduleCallback() {
     void issueDataCallback(Timer timer) {
       _scheduledDataCallback = null;
-      if (_clientDataHandler !== null) {
+      if (_clientDataHandler != null) {
         _clientDataHandler();
         _checkScheduleCallback();
       }
     }
 
     void issueLineCallback(Timer timer) {
       _scheduledLineCallback = null;
-      if (_clientLineHandler !== null) {
+      if (_clientLineHandler != null) {
         _clientLineHandler();
         _checkScheduleCallback();
       }
     }
 
     void issueCloseCallback(Timer timer) {
       _scheduledCloseCallback = null;
       if (!_closed) {
-        if (_clientCloseHandler !== null) _clientCloseHandler();
+        if (_clientCloseHandler != null) _clientCloseHandler();
         _closed = true;
       }
     }
 
     if (!_closed) {
       // Schedule data callback if string data available.
       if (_clientDataHandler != null &&
           !_decoder.isEmpty &&
           _scheduledDataCallback == null) {
         if (_scheduledLineCallback != null) {
@@ skipping 27 matching lines @@
   bool _inputClosed = false;  // Is the underlying input stream closed?
   bool _closed = false;  // Is this stream closed.
   bool _eof = false;  // Has all data been read from the decoder?
   Timer _scheduledDataCallback;
   Timer _scheduledLineCallback;
   Timer _scheduledCloseCallback;
   Function _clientDataHandler;
   Function _clientLineHandler;
   Function _clientCloseHandler;
 }