tango.io.stream.Delimiters source code

1 /*******************************************************************************
2 
3         copyright:      Copyright (c) 2004 Kris Bell. All rights reserved
4 
5         license:        BSD style: $(LICENSE)
6 
7         version:        Initial release: January 2006
8 
9         author:         Kris
10 
11 *******************************************************************************/
12 
13 module tango.io.stream.Delimiters;
14 
15 private import tango.io.model.IConduit;
16 private import tango.io.stream.Iterator;
17 
18 /*******************************************************************************
19 
20         Iterate across a set of text patterns.
21 
22         Each pattern is exposed to the client as a slice of the original
23         content, where the slice is transient. If you need to retain the
24         exposed content, then you should .dup it appropriately.
25 
26         The content exposed via an iterator is supposed to be entirely
27         read-only. All current iterators abide by this rule, but it is
28         possible a user could mutate the content through a get() slice.
29         To enforce the desired read-only aspect, the code would have to
30         introduce redundant copying or the compiler would have to support
31         read-only arrays.
32 
33         See Lines, Patterns, Quotes.
34 
35 *******************************************************************************/
36 
37 class Delimiters(T) : Iterator!(T)
38 {
39         private const(T)[] delim;
40 
41         /***********************************************************************
42 
43                 Construct an uninitialized iterator. For example:
44                 ---
45                 auto lines = new Lines!(char);
46 
47                 void somefunc (InputStream stream)
48                 {
49                         foreach (line; lines.set(stream))
50                                  Cout (line).newline;
51                 }
52                 ---
53 
54                 Construct a streaming iterator upon a stream:
55                 ---
56                 void somefunc (InputStream stream)
57                 {
58                         foreach (line; new Lines!(char) (stream))
59                                  Cout (line).newline;
60                 }
61                 ---
62 
63                 Construct a streaming iterator upon a conduit:
64                 ---
65                 foreach (line; new Lines!(char) (new File ("myfile")))
66                          Cout (line).newline;
67                 ---
68 
69         ***********************************************************************/
70 
71         this (const(T)[] delim, InputStream stream = null)
72         {
73                 this.delim = delim;
74                 super (stream);
75         }
76 
77         /***********************************************************************
78 
79         ***********************************************************************/
80 
81         protected override size_t scan (const(void)[] data)
82         {
83                 auto content = (cast(const(T)*) data.ptr) [0 .. data.length / T.sizeof];
84 
85                 if (delim.length is 1)
86                    {
87                    foreach (i, T c; content)
88                             if (c is delim[0])
89                                 return found (set (content.ptr, 0, i, i));
90                    }
91                 else
92                    foreach (i, T c; content)
93                             if (has (delim, c))
94                                 return found (set (content.ptr, 0, i, i));
95 
96                 return notFound();
97         }
98 }
99 
100 
101 
102 /*******************************************************************************
103 
104 *******************************************************************************/
105 
106 debug(UnitTest)
107 {
108         private import tango.io.device.Array;
109 
110         unittest
111         {
112                 auto p = new Delimiters!(char) (", ", new Array("blah".dup));
113         }
114 }