| // Copyright (c) 2015, 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. |
| |
| /// Declarations for variable arguments support |
| /// (rest params and spread operator). |
| /// |
| /// These are currently *not* supported by dart2js or Dartium. |
| library js.varargs; |
| |
| class _Rest { |
| const _Rest(); |
| } |
| |
| /// Annotation to tag ES6 rest parameters (https://goo.gl/r0bJ1K). |
| /// |
| /// This is *not* supported by dart2js or Dartium (yet). |
| /// |
| /// This is meant to be used by the Dart Dev Compiler |
| /// when compiling helper functions of its runtime to ES6. |
| /// |
| /// The following function: |
| /// |
| /// foo(a, b, @rest others) { ... } |
| /// |
| /// Will be compiled to ES6 code like the following: |
| /// |
| /// function foo(a, b, ...others) { ... } |
| /// |
| /// Which is roughly equivalent to the following ES5 code: |
| /// |
| /// function foo(a, b/*, ...others*/) { |
| /// var others = [].splice.call(arguments, 2); |
| /// ... |
| /// } |
| /// |
| const _Rest rest = _Rest(); |
| |
| /// Intrinsic function that maps to the ES6 spread operator |
| /// (https://goo.gl/NedHKr). |
| /// |
| /// This is *not* supported by dart2js or Dartium (yet), |
| /// and *cannot* be called at runtime. |
| /// |
| /// This is meant to be used by the Dart Dev Compiler when |
| /// compiling its runtime to ES6. |
| /// |
| /// The following expression: |
| /// |
| /// foo(a, b, spread(others)) |
| /// |
| /// Will be compiled to ES6 code like the following: |
| /// |
| /// foo(a, b, ...others) |
| /// |
| /// Which is roughly equivalent to the following ES5 code: |
| /// |
| /// foo.apply(null, [a, b].concat(others)) |
| /// |
| dynamic spread(args) { |
| throw StateError('The spread function cannot be called, ' |
| 'it should be compiled away.'); |
| } |