hunt.concurrency.Promise source code

1 /*
2  * Hunt - A refined core library for D programming language.
3  *
4  * Copyright (C) 2018-2019 HuntLabs
5  *
6  * Website: https://www.huntlabs.net/
7  *
8  * Licensed under the Apache-2.0 License.
9  *
10  */
11 
12 module hunt.concurrency.Promise;
13 
14 import hunt.Exceptions;
15 
16 /**
17  * <p>A callback abstraction that handles completed/failed events of asynchronous operations.</p>
18  *
19  * @param <C> the type of the context object
20  */
21 interface Promise(C) {
22 
23     string id();
24 
25     /**
26      * <p>Callback invoked when the operation completes.</p>
27      *
28      * @param result the context
29      * @see #failed(Throwable)
30      */
31     void succeeded(C result);
32 
33     /**
34      * <p>Callback invoked when the operation fails.</p>
35      *
36      * @param x the reason for the operation failure
37      */
38     void failed(Exception x) ;
39 
40     /**
41      * <p>Empty implementation of {@link Promise}.</p>
42      *
43      * @param (U) the type of the result
44      */
45     class Adapter(U) : Promise!U {
46 
47         void succeeded(C result){
48             
49         }
50         
51         void failed(Throwable x) {
52 
53         }
54     }
55 }
56 
57 
58 class DefaultPromise(C) : Promise!C
59 {
60     string id() { return "default"; }
61 
62     void succeeded(C result) {
63     }
64     
65     void failed(Exception x) {
66     }
67 }
68