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1
8
9 package net.sourceforge.chaperon.process.extended;
10
11 public class CharBuffer
12 {
13 public CharBufferEntry head = null;
14 public CharBufferEntry tail = null;
15 public CharBufferEntry current = null;
16 public int position;
17
18 public void push(char[] text, int position, int length)
19 {
20 if (head==null)
21 {
22 head = new CharBufferEntry(text, position, length, null);
23 tail = head;
24 current = head;
25 this.position = position;
26 }
27 else
28 {
29 tail = new CharBufferEntry(text, position, length, tail);
30
31 if ((this.position==(current.position+current.length)) && (current.next==tail))
32 {
33 current = current.next;
34 this.position = current.position;
35 }
36 }
37 }
38
39 public char read()
40 {
41 if ((position<(current.position+current.length)) && (current!=null))
42 {
43 char c = current.text[position];
44
45 position++;
46 if ((position==(current.position+current.length)) && (current.next!=null))
47 {
48 current = current.next;
49 position = current.position;
50 }
51
52 return c;
53 }
54 else
55 throw new IllegalStateException  ("Buffer is empty");
56 }
57
58 public char peek()
59 {
60 if ((position<(current.position+current.length)) && (current!=null))
61 return current.text[position];
62 else
63 throw new IllegalStateException ("Buffer is empty");
64 }
65
66 public boolean available()
67 {
68 return (current!=null) && (position<(current.position+current.length));
69 }
70
71 public int remaining()
72 {
73 int remaining = (current.position+current.length)-position;
74 CharBufferEntry next = current.next;
75 while (next!=null)
76 {
77 remaining += next.length;
78 next = next.next;
79 }
80
81 return remaining;
82 }
83
84 public void back()
85 {
86 if (position>current.position)
87 position--;
88 else if (current.previous!=null)
89 {
90 current = current.previous;
91 position = (current.position+current.length)-1;
92 }
93 else
94 throw new IllegalStateException ("Couldn't move back");
95 }
96
97 public void clear()
98 {
99 head = null;
100 tail = null;
101 current = null;
102 }
103
104 public class CharBufferEntry
105 {
106 public char[] text;
107 public int position;
108 public int length;
109 public CharBufferEntry previous = null;
110 public CharBufferEntry next = null;
111
112 public CharBufferEntry(char[] text, int position, int length, CharBufferEntry previous)
113 {
114 this.text = text;
115 this.position = position;
116 this.length = length;
117 this.previous = previous;
118 if (previous!=null)
119 previous.next = this;
120 }
121 }
122 }
123 |
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