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1 package kawa.standard;
2 import gnu.text.Char;
3 import gnu.lists.*;
4 import java.io.Reader  ;
5 import java.io.InputStream ;
6 import gnu.mapping.Procedure0or1;
7 import gnu.mapping.WrongType;
8 import gnu.mapping.InPort;
9
10 public class readchar extends Procedure0or1
11 {
12 public static final readchar readChar = new readchar(false);
13 public static final readchar peekChar = new readchar(true);
14
15 boolean peeking;
16 public readchar(boolean peeking)
17 {
18 super(peeking ? "peek-char" : "read-char");
19 this.peeking = peeking;
20 }
21
22 final Object readChar (InPort port)
23 {
24 try
25 {
26 int ch = peeking ? port.peek() : port.read();
27 if (ch < 0)
28 return Sequence.eofValue;
29 return Char.make (ch);
30 }
31 catch (java.io.IOException e)
32 {
33 throw new RuntimeException ("IO Exception caught");
34 }
35 }
36
37 final Object readChar (Reader port)
38 {
39 try
40 {
41 int ch;
42 if (peeking)
43 {
44 port.mark(1);
45 ch = port.read();
46 port.reset();
47 }
48 else
49 ch = port.read();
50 if (ch < 0)
51 return Sequence.eofValue;
52 return Char.make (ch);
53 }
54 catch (java.io.IOException e)
55 {
56 throw new RuntimeException ("IO Exception caught");
57 }
58 }
59
60 final Object readChar (InputStream port)
61 {
62 try
63 {
64 int ch;
65 if (peeking)
66 {
67 port.mark(1);
68 ch = port.read();
69 port.reset();
70 }
71 else
72 ch = port.read();
73 if (ch < 0)
74 return Sequence.eofValue;
75 return Char.make (ch);
76 }
77 catch (java.io.IOException e)
78 {
79 throw new RuntimeException ("IO Exception caught");
80 }
81 }
82
83 public final Object apply0 ()
84 {
85 return readChar (InPort.inDefault());
86 }
87
88 public final Object apply1 (Object arg1)
89 {
90 if (arg1 instanceof InPort)
91 return readChar ((InPort) arg1);
92 if (arg1 instanceof Reader )
93 return readChar ((Reader ) arg1);
94 if (arg1 instanceof InputStream )
95 return readChar ((InputStream ) arg1);
96 throw new WrongType (this, 1, arg1, "<input-port>");
97 }
98 }
99 |
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