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1
21
22 package org.armedbear.lisp;
23
24 import java.io.StringWriter  ;
25
26 public final class StringOutputStream extends Stream
27 {
28 private final StringWriter stringWriter;
29
30 public StringOutputStream()
31 {
32 this(Symbol.CHARACTER);
33 }
34
35 private StringOutputStream(LispObject elementType)
36 {
37 this.elementType = elementType;
38 isInputStream = false;
39 isOutputStream = true;
40 isCharacterStream = true;
41 isBinaryStream = false;
42 setWriter(stringWriter = new StringWriter ());
43 }
44
45 public LispObject typeOf()
46 {
47 return Symbol.STRING_OUTPUT_STREAM;
48 }
49
50 public LispClass classOf()
51 {
52 return BuiltInClass.STRING_OUTPUT_STREAM;
53 }
54
55 public LispObject typep(LispObject type) throws ConditionThrowable
56 {
57 if (type == Symbol.STRING_OUTPUT_STREAM)
58 return T;
59 if (type == Symbol.STRING_STREAM)
60 return T;
61 if (type == BuiltInClass.STRING_OUTPUT_STREAM)
62 return T;
63 if (type == BuiltInClass.STRING_STREAM)
64 return T;
65 return super.typep(type);
66 }
67
68 public void _writeChar(char c) throws ConditionThrowable
69 {
70 if (elementType == NIL)
71 writeError();
72 super._writeChar(c);
73 }
74
75 public void _writeChars(char[] chars, int start, int end)
76 throws ConditionThrowable
77 {
78 if (elementType == NIL)
79 writeError();
80 super._writeChars(chars, start, end);
81 }
82
83 public void _writeString(String s) throws ConditionThrowable
84 {
85 if (elementType == NIL)
86 writeError();
87 super._writeString(s);
88 }
89
90 public void _writeLine(String s) throws ConditionThrowable
91 {
92 if (elementType == NIL)
93 writeError();
94 super._writeLine(s);
95 }
96
97 private void writeError() throws ConditionThrowable
98 {
99 signal(new TypeError("Attempt to write to a string output stream of element type NIL."));
100 }
101
102 protected long _getFilePosition() throws ConditionThrowable
103 {
104 if (elementType == NIL)
105 return 0;
106 return stringWriter.toString().length();
107 }
108
109 public LispObject getString() throws ConditionThrowable
110 {
111 if (elementType == NIL)
112 return new NilVector(0);
113 StringBuffer sb = stringWriter.getBuffer();
114 SimpleString s = new SimpleString(sb);
115 sb.setLength(0);
116 return s;
117 }
118
119 public String toString()
120 {
121 return unreadableString("STRING-OUTPUT-STREAM");
122 }
123
124 private static final Primitive1 MAKE_STRING_OUTPUT_STREAM =
127 new Primitive1("%make-string-output-stream", PACKAGE_SYS, false,
128 "element-type")
129 {
130 public LispObject execute(LispObject arg) throws ConditionThrowable
131 {
132 return new StringOutputStream(arg);
133 }
134 };
135
136 private static final Primitive1 GET_OUTPUT_STREAM_STRING =
139 new Primitive1("get-output-stream-string", "string-output-stream")
140 {
141 public LispObject execute(LispObject arg) throws ConditionThrowable
142 {
143 try {
144 return ((StringOutputStream)arg).getString();
145 }
146 catch (ClassCastException e) {
147 return signal(new TypeError(this, Symbol.STRING_OUTPUT_STREAM));
148 }
149 }
150 };
151 }
152 |
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