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pkg/dev_compiler/tool/input_sdk/lib/core/annotations.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.
-
-part of dart.core;
-
-/**
- * The annotation `@Deprecated('expires when')` marks a feature as deprecated.
- *
- * The annotation `@deprecated` is a shorthand for deprecating until
- * an unspecified "next release".
- *
- * The intent of the `@Deprecated` annotation is to inform users of a feature
- * that they should change their code, even if it is currently still working
- * correctly.
- *
- * A deprecated feature is scheduled to be removed at a later time, possibly
- * specified as the "expires" field of the annotation.
- * This means that a deprecated feature should not be used, or code using it
- * will break at some point in the future. If there is code using the feature,
- * that code should be rewritten to not use the deprecated feature.
- *
- * A deprecated feature should document how the same effect can be achieved,
- * so the programmer knows how to rewrite the code.
- *
- * The `@Deprecated` annotation applies to libraries, top-level declarations
- * (variables, getters, setters, functions, classes and typedefs),
- * class-level declarations (variables, getters, setters, methods, operators or
- * constructors, whether static or not), named optional arguments and
- * trailing optional positional parameters.
- *
- * Deprecation is transitive:
- *
- *  - If a library is deprecated, so is every member of it.
- *  - If a class is deprecated, so is every member of it.
- *  - If a variable is deprecated, so are its implicit getter and setter.
- *
- *
- * A tool that processes Dart source code may report when:
- *
- * - the code imports a deprecated library.
- * - the code exports a deprecated library, or any deprecated member of
- *   a non-deprecated library.
- * - the code refers statically to a deprecated declaration.
- * - the code dynamically uses a member of an object with a statically known
- *   type, where the member is deprecated on the static type of the object.
- * - the code dynamically calls a method with an argument where the
- *   corresponding optional parameter is deprecated on the object's static type.
- *
- *
- * If the deprecated use is inside a library, class or method which is itself
- * deprecated, the tool should not bother the user about it.
- * A deprecated feature is expected to use other deprecated features.
- */
-class Deprecated {
-  /**
-   * A description of when the deprecated feature is expected to be retired.
-   */
-  final String expires;
-
-  /**
-   * Create a deprecation annotation which specifies the expiration of the
-   * annotated feature.
-   *
-   * The [expires] argument should be readable by programmers, and should state
-   * when an annotated feature is expected to be removed.
-   * This can be specified, for example, as a date, as a release number, or
-   * as relative to some other change (like "when bug 4418 is fixed").
-   */
-  const Deprecated(String expires) : this.expires = expires;
-
-  String toString() => "Deprecated feature. Will be removed $expires";
-}
-
-class _Override {
-  const _Override();
-}
-
-/**
- * Marks a feature as [Deprecated] until the next release.
- */
-const Deprecated deprecated = const Deprecated("next release");
-
-/**
- * The annotation `@override` marks an instance member as overriding a
- * superclass member with the same name.
- *
- * The annotation applies to instance methods, getters and setters, and to
- * instance fields, where it means that the implicit getter and setter of the
- * field is marked as overriding, but the field itself is not.
- *
- * The intent of the `@override` notation is to catch situations where a
- * superclass renames a member, and an independent subclass which used to
- * override the member, could silently continue working using the
- * superclass implementation.
- *
- * The editor, or a similar tool aimed at the programmer, may report if no
- * declaration of an annotated member is inherited by the class from either a
- * superclass or an interface.
- *
- * Use the `@override` annotation judiciously and only for methods where
- * the superclass is not under the programmer's control, the superclass is in a
- * different library or package, and it is not considered stable.
- * In any case, the use of `@override` is optional.
- *
- * For example, the annotation is intentionally not used in the Dart platform
- * libraries, since they only depend on themselves.
- */
-const Object override = const _Override();
-
-class _Proxy {
-  const _Proxy();
-}
-
-/**
- * The annotation `@proxy` marks a class as implementing members dynamically
- * through `noSuchMethod`.
- *
- * The annotation applies to any class. It is inherited by subclasses from both
- * superclass and interfaces.
- *
- * If a class is annotated with `@proxy`, or it implements any class that is
- * annotated, then the class is considered to implement any member with regard
- * to static type analysis.
- * As such, it is not a static type warning to access any member of the object
- * which is not implemented by the class, or to call a method with a different
- * number of parameters than it is declared with.
- *
- * The annotation does not change which classes the annotated class implements,
- * and does not prevent static warnings for assigning an object to a variable
- * with a static type not implemented by the object.
- *
- * The suppression of warnings only affect static type warnings about
- * member access.
- * The runtime type of the object is unaffected.
- * It is not considered to implement any special interfaces,
- * so assigning it to a typed variable may fail in checked mode,
- * and testing it with the `is` operator
- * will only return true for types it actually implements or extends.
- * Accessing a member which isn't implemented by the class
- * will cause the `noSuchMethod` method to be called normally,
- * the `@proxy` annotation merely states the intent to handle (some of) those
- * `noSuchMethod` calls gracefully.
- *
- * A class that marked as `@proxy` should override the `noSuchMethod`
- * declared on [Object].
- *
- * The intent of the `@proxy` notation is to create objects that implement a
- * type (or multiple types) that are not known at compile time. If the types
- * are known at compile time, a class can be written that implements these
- * types.
- */
-const Object proxy = const _Proxy();