OLD | NEW |
1 # Copyright 2014 The Chromium Authors. All rights reserved. | 1 # Copyright 2014 The Chromium Authors. All rights reserved. |
2 # Use of this source code is governed by a BSD-style license that can be | 2 # Use of this source code is governed by a BSD-style license that can be |
3 # found in the LICENSE file. | 3 # found in the LICENSE file. |
4 | 4 |
5 """ | 5 """ |
6 Promise used by the python bindings. | 6 Promise used by the python bindings. |
7 | 7 |
8 The API is following the ECMAScript 6 API for promises. | 8 The API is following the ECMAScript 6 API for promises. |
9 """ | 9 """ |
10 | 10 |
| 11 import sys |
| 12 |
11 | 13 |
12 class Promise(object): | 14 class Promise(object): |
13 """The promise object.""" | 15 """The promise object.""" |
14 | 16 |
15 STATE_PENDING = 0 | 17 STATE_PENDING = 0 |
16 STATE_FULLFILLED = 1 | 18 STATE_FULLFILLED = 1 |
17 STATE_REJECTED = 2 | 19 STATE_REJECTED = 2 |
18 STATE_BOUND = 3 | 20 STATE_BOUND = 3 |
19 | 21 |
20 def __init__(self, generator_function): | 22 def __init__(self, generator_function): |
21 """ | 23 """ |
22 Constructor. | 24 Constructor. |
23 | 25 |
24 Args: | 26 Args: |
25 generator_function: A function taking 2 arguments: resolve and reject. | 27 generator_function: A function taking 2 arguments: resolve and reject. |
26 When |resolve| is called, the promise is fullfilled with the given value. | 28 When |resolve| is called, the promise is fullfilled with the given value. |
27 When |reject| is called, the promise is rejected with the given value. | 29 When |reject| is called, the promise is rejected with the given value. |
28 A promise can only be resolved or rejected once, all following calls will | 30 A promise can only be resolved or rejected once, all following calls will |
29 have no effect. | 31 have no effect. |
30 """ | 32 """ |
31 self._onCatched = [] | 33 self._onCatched = [] |
32 self._onFulfilled = [] | 34 self._onFulfilled = [] |
33 self._onRejected = [] | 35 self._onRejected = [] |
34 self._state = Promise.STATE_PENDING | 36 self._state = Promise.STATE_PENDING |
35 self._result = None | 37 self._result = None |
36 if generator_function: | 38 try: |
37 generator_function(self._Resolve, self._Reject) | 39 generator_function(self._Resolve, self._Reject) |
| 40 except Exception as e: |
| 41 # Adding traceback similarly to python 3.0 (pep-3134) |
| 42 e.__traceback__ = sys.exc_info()[2] |
| 43 self._Reject(e) |
38 | 44 |
39 @staticmethod | 45 @staticmethod |
40 def Resolve(value): | 46 def Resolve(value): |
41 """ | 47 """ |
42 If value is a promise, make a promise that have the same behavior as value, | 48 If value is a promise, make a promise that have the same behavior as value, |
43 otherwise make a promise that fulfills to value. | 49 otherwise make a promise that fulfills to value. |
44 """ | 50 """ |
45 if isinstance(value, Promise): | 51 if isinstance(value, Promise): |
46 return value | 52 return value |
47 return Promise(lambda x, y: x(value)) | 53 return Promise(lambda x, y: x(value)) |
(...skipping 129 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
177 | 183 |
178 | 184 |
179 def _Delegate(resolve, reject, action): | 185 def _Delegate(resolve, reject, action): |
180 def _Run(x): | 186 def _Run(x): |
181 try: | 187 try: |
182 if action: | 188 if action: |
183 resolve(action(x)) | 189 resolve(action(x)) |
184 else: | 190 else: |
185 resolve(x) | 191 resolve(x) |
186 except Exception as e: | 192 except Exception as e: |
| 193 # Adding traceback similarly to python 3.0 (pep-3134) |
| 194 e.__traceback__ = sys.exc_info()[2] |
187 reject(e) | 195 reject(e) |
188 return _Run | 196 return _Run |
OLD | NEW |