Move FutureImpl and CompleterImpl from coreimpl to core, while also making them private.

lib/coreimpl/future_implementation.dart

-// Copyright 2012 Google Inc. All Rights Reserved.
-// Dart core library.
-
-class FutureImpl<T> implements Future<T> {
-
-  bool _isComplete = false;
-
-  /**
-   * Value that was provided to this Future by the Completer
-   */
-  T _value;
-
-  /**
-   * Exception that occured, if there was a problem providing
-   * Value.
-   */
-  Object _exception;
-
-  /**
-   * Stack trace associated with [_exception], if one was provided.
-   */
-  Object _stackTrace;
-
-  /**
-   * true, if any onException handler handled the exception.
-   */
-  bool _exceptionHandled = false;
-
-  /**
-   * Listeners waiting to receive the value of this future.
-   */
-  final List<Function> _successListeners;
-
-  /**
-   * Exception handlers waiting for exceptions.
-   */
-  final List<Function> _exceptionHandlers;
-
-  /**
-   * Listeners waiting to be called when the future completes.
-   */
-  final List<Function> _completionListeners;
-
-  FutureImpl()
-    : _successListeners = [],
-      _exceptionHandlers = [],
-      _completionListeners = [];
-
-  factory FutureImpl.immediate(T value) {
-    final res = new FutureImpl();
-    res._setValue(value);
-    return res;
-  }
-
-  T get value {
-    if (!isComplete) {
-      throw new FutureNotCompleteException();
-    }
-    if (_exception !== null) {
-      throw new FutureUnhandledException(_exception, stackTrace);
-    }
-    return _value;
-  }
-
-  Object get exception {
-    if (!isComplete) {
-      throw new FutureNotCompleteException();
-    }
-    return _exception;
-  }
-
-  Object get stackTrace {
-    if (!isComplete) {
-      throw new FutureNotCompleteException();
-    }
-    return _stackTrace;
-  }
-
-  bool get isComplete {
-    return _isComplete;
-  }
-
-  bool get hasValue {
-    return isComplete && _exception === null;
-  }
-
-  void then(void onSuccess(T value)) {
-    if (hasValue) {
-      onSuccess(value);
-    } else if (!isComplete) {
-      _successListeners.add(onSuccess);
-    } else if (!_exceptionHandled) {
-      throw new FutureUnhandledException(_exception, stackTrace);
-    }
-  }
-
-  void handleException(bool onException(Object exception)) {
-    if (_exceptionHandled) return;
-    if (_isComplete) {
-       if (_exception != null) {
-         _exceptionHandled = onException(_exception);
-       }
-    } else {
-      _exceptionHandlers.add(onException);
-    }
-  }
-
-  void onComplete(void complete(Future<T> future)) {
-    if (_isComplete) {
-      try {
-        complete(this);
-      } catch (e) {}
-    } else {
-      _completionListeners.add(complete);
-    }
-  }
-
-  void _complete() {
-    _isComplete = true;
-
-    try {
-      if (_exception !== null) {
-        for (Function handler in _exceptionHandlers) {
-          // Explicitly check for true here so that if the handler returns null,
-          // we don't get an exception in checked mode.
-          if (handler(_exception) == true) {
-            _exceptionHandled = true;
-            break;
-          }
-        }
-      }
-
-      if (hasValue) {
-        for (Function listener in _successListeners) {
-          listener(value);
-        }
-      } else {
-        if (!_exceptionHandled && _successListeners.length > 0) {
-          throw new FutureUnhandledException(_exception, stackTrace);
-        }
-      }
-    } finally {
-      for (Function listener in _completionListeners) {
-        try {
-          listener(this);
-        } catch (e) {}
-      }
-    }
-  }
-
-  void _setValue(T value) {
-    if (_isComplete) {
-      throw new FutureAlreadyCompleteException();
-    }
-    _value = value;
-    _complete();
-  }
-
-  void _setException(Object exception, Object stackTrace) {
-    if (exception === null) {
-      // null is not a legal value for the exception of a Future.
-      throw new ArgumentError(null);
-    }
-    if (_isComplete) {
-      throw new FutureAlreadyCompleteException();
-    }
-    _exception = exception;
-    _stackTrace = stackTrace;
-    _complete();
-  }
-
-  Future transform(Function transformation) {
-    final completer = new Completer();
-
-    _forwardException(this, completer);
-
-    then((v) {
-      var transformed = null;
-      try {
-        transformed = transformation(v);
-      } catch (e, stackTrace) {
-        completer.completeException(e, stackTrace);
-        return;
-      }
-      completer.complete(transformed);
-    });
-
-    return completer.future;
-  }
-
-  Future chain(Function transformation) {
-    final completer = new Completer();
-
-    _forwardException(this, completer);
-    then((v) {
-      var future = null;
-      try {
-        future = transformation(v);
-      } catch (ex, stackTrace) {
-        completer.completeException(ex, stackTrace);
-        return;
-      }
-
-      _forward(future, completer);
-    });
-    return completer.future;
-  }
-
-  Future transformException(transformation(Object exception)) {
-    final completer = new Completer();
-
-    handleException((ex) {
-      try {
-        final result = transformation(ex);
-
-        // If the transformation itself returns a future, then we will
-        // complete to what that completes to.
-        if (result is Future) {
-          _forward(result, completer);
-        } else {
-          completer.complete(result);
-        }
-      } catch (innerException, stackTrace) {
-        completer.completeException(innerException, stackTrace);
-      }
-      return true;
-    });
-
-    then(completer.complete);
-
-    return completer.future;
-  }
-
-  /**
-   * Forwards the success or error completion from [future] to [completer].
-   */
-  _forward(Future future, Completer completer) {
-    _forwardException(future, completer);
-    future.then(completer.complete);
-  }
-
-  /**
-   * Forwards the exception completion from [future] to [completer].
-   */
-  _forwardException(Future future, Completer completer) {
-    future.handleException((e) {
-      completer.completeException(e, future.stackTrace);
-      return true;
-    });
-  }
-}
-
-class CompleterImpl<T> implements Completer<T> {
-
-  final FutureImpl<T> _futureImpl;
-
-  CompleterImpl() : _futureImpl = new FutureImpl() {}
-
-  Future<T> get future {
-    return _futureImpl;
-  }
-
-  void complete(T value) {
-    _futureImpl._setValue(value);
-  }
-
-  void completeException(Object exception, [Object stackTrace]) {
-    _futureImpl._setException(exception, stackTrace);
-  }
-}