1 | #Region "Microsoft.VisualBasic::258dc4860a8137aec93da96af2701d48, Microsoft.VisualBasic.Core\Language\Language\Python\Collection.vb" |
2 | |
3 | ' Author: |
4 | ' |
5 | ' asuka (amethyst.asuka@gcmodeller.org) |
6 | ' xie (genetics@smrucc.org) |
7 | ' xieguigang (xie.guigang@live.com) |
8 | ' |
9 | ' Copyright (c) 2018 GPL3 Licensed |
10 | ' |
11 | ' |
12 | ' GNU GENERAL PUBLIC LICENSE (GPL3) |
13 | ' |
14 | ' |
15 | ' This program is free software: you can redistribute it and/or modify |
16 | ' it under the terms of the GNU General Public License as published by |
17 | ' the Free Software Foundation, either version 3 of the License, or |
18 | ' (at your option) any later version. |
19 | ' |
20 | ' This program is distributed in the hope that it will be useful, |
21 | ' but WITHOUT ANY WARRANTY; without even the implied warranty of |
22 | ' MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
23 | ' GNU General Public License for more details. |
24 | ' |
25 | ' You should have received a copy of the GNU General Public License |
26 | ' along with this program. If not, see <http://www.gnu.org/licenses/>. |
27 | |
28 | |
29 | |
30 | ' /********************************************************************************/ |
31 | |
32 | ' Summaries: |
33 | |
34 | ' Module Collection |
35 | ' |
36 | ' Function: slice |
37 | ' |
38 | ' |
39 | ' /********************************************************************************/ |
40 | |
41 | #End Region |
42 | |
43 | Imports System.Runtime.CompilerServices |
44 | |
45 | Namespace Language.Python |
46 | |
47 | Public Module Collection |
48 | |
49 | ''' <summary> |
50 | ''' 将序列之中的指定区域的内容取出来 |
51 | ''' </summary> |
52 | ''' <typeparam name="T"></typeparam> |
53 | ''' <param name="[set]"></param> |
54 | ''' <param name="start"></param> |
55 | ''' <param name="[stop]"> |
56 | ''' 可以接受负数,如果为负数,则表示终止的下标为长度将去这个stop值的结果,即从后往前数 |
57 | ''' </param> |
58 | ''' <param name="[step]"></param> |
59 | ''' <returns></returns> |
60 | <Extension> |
61 | Public Iterator Function slice(Of T)([set] As IEnumerable(Of T), start%, stop%, Optional step% = 1) As IEnumerable(Of T) |
62 | Dim array As T() = [set].Skip(start).ToArray |
63 | |
64 | If [stop] < 0 Then |
65 | [stop] = array.Length + [stop] |
66 | End If |
67 | |
68 | [stop] -= start |
69 | [stop] -= 1 |
70 | |
71 | For i As Integer = 0 To [stop] Step [step] |
72 | Yield array(i) |
73 | Next |
74 | End Function |
75 | End Module |
76 | End Namespace |