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1 package gnu.jemacs.buffer;
2 import gnu.mapping.*;
3 import java.io.*;
4 import gnu.lists.CharBuffer;
5
6 public class BufferReader extends InPort
7 {
8 CharBuffer content;
9 int rangeStart;
10 int rangeLength;
11
12 public BufferReader(CharBuffer content, String  name, int start, int count)
13 {
14 super(gnu.text.NullReader.nullReader, name);
15 this.content = content;
16 buffer = content.getArray();
17 rangeStart = start;
18 rangeLength = count;
19 if (start < content.gapStart)
20 {
21 pos = start;
22 limit = start + count;
23 if (limit > content.gapStart)
24 limit = content.gapStart;
25 }
26 else
27 {
28 int gapSize = content.gapEnd - content.gapStart;
29 pos = start + gapSize;
30 int length = content.getArray().length;
31 limit = pos + count > length ? length : pos + count;
32 }
33 }
34
35 public int read ()
36 {
37 if (pos < limit)
38 return buffer[pos++];
39 if (limit == content.gapStart)
40 {
41 int gapSize = content.gapEnd - content.gapStart;
42 pos = content.gapEnd;
43 int count = rangeLength - (content.gapStart - rangeStart);
44 int length = content.getArray().length;
45 limit = pos + count > length ? length : pos + count;
46 if (pos < limit)
47 return buffer[pos++];
48 }
49 return -1;
50 }
51
52
56 public void reset () throws IOException
57 {
58 if (readAheadLimit <= 0)
59 throw new IOException ("mark invalid");
60 if (pos >= content.gapEnd && markPos <= content.gapStart)
61 limit = content.gapEnd;
62 pos = markPos;
63 readAheadLimit = 0;
64 }
65
66 public int getLineNumber ()
67 {
68 throw new Error ("BufferReader.getLineNumber - not implemented");
69 }
70
71 public int getColumnNumber ()
72 {
73 throw new Error ("BufferReader.getColumnNumber - not implemented");
74 }
75
76 }
77 |
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