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1 package gnu.q2.lang;
2 import gnu.kawa.lispexpr.*;
3 import gnu.expr.QuoteExp;
4 import gnu.text.*;
5 import gnu.mapping.*;
6 import gnu.lists.*;
7 import gnu.expr.Keyword;
8 import gnu.kawa.xml.MakeAttribute;
9
10
11
12 public class Q2Read extends LispReader
13 {
14 void init()
15 {
16 initialColonIsKeyword = false;
17 ((InPort) port).readState = ' ';
18 }
19
20 public Q2Read(InPort port)
21 {
22 super(port);
23 init();
24 }
25
26 public Q2Read(InPort port, SourceMessages messages)
27 {
28 super(port, messages);
29 init();
30 }
31
32 int skipIndentation ()
33 throws java.io.IOException  , SyntaxException
34 {
35 int numTabs = 0, numSpaces = 0;
36 int ch = port.read();
37 while (ch == '\t')
38 {
39 numTabs++;
40 ch = port.read();
41 }
42 while (ch == ' ')
43 {
44 numSpaces++;
45 ch = port.read();
46 }
47 if (ch < 0)
48 return -1;
49 port.unread();
50 return (numTabs << 16) + numSpaces;
51 }
52
53 boolean singleLine()
54 {
55 return interactive && nesting == 0;
56 }
57
58 public Object readCommand ()
59 throws java.io.IOException , SyntaxException
60 {
61 return readCommand(false);
62 }
63
64 public Object readCommand (boolean forceList)
65 throws java.io.IOException , SyntaxException
66 {
67 int line = port.getLineNumber();
68 int startColumn = port.getColumnNumber();
69 int lastColumn = startColumn;
70 Object obj = LList.Empty;
71 PairWithPosition pair = null, last = null;
72 for (;;)
73 {
74 int ch = read();
75 if (ch < 0)
76 break;
77 if (ch == ' ' || ch == '\t')
78 continue;
79 unread();
80 if (ch == ')')
81 break;
82 line = port.getLineNumber();
83 int column = port.getColumnNumber();
84 while (ch == '\r' || ch == '\n')
85 {
86 if (singleLine())
87 return obj;
88 ch = read();
89 skipIndentation(); column = port.getColumnNumber();
91 ch = peek();
92 if (column <= startColumn)
93 break;
94 }
95 if (column <= startColumn && last != null)
96 break;
97 Object next;
98 if (column == lastColumn && last != null)
99 next = readCommand();
100 else if (column < lastColumn && last != null)
101 {
102 PairWithPosition p = pair;
103 for (;;)
104 {
105 Object n = p.cdr;
106 if (n == LList.Empty)
107 break;
108 PairWithPosition np = (PairWithPosition) n;
109 int pColumn = np.getColumnNumber()-1;
110 if (pColumn >= column)
111 {
112 if (pColumn > column)
113 error('e', "some tokens on previous line indented more than current line");
114 n = np.cdr;
115 if (n != LList.Empty)
116 {
117 if (((PairWithPosition) n).getColumnNumber()-1==column)
118 {
119 p = (PairWithPosition) n;
120 continue;
121 }
122 last = (PairWithPosition)
123 makePair(np, port.getLineNumber(), column);
124 p.cdr = last;
125 }
126 break;
127 }
128 p = np;
129 }
130 next = readCommand();
131 }
132 else
133 next = readObject();
134 if (next == Sequence.eofValue)
135 break;
136 lastColumn = column;
137 String filename = port.getName();
138 PairWithPosition cur = PairWithPosition.make(next, LList.Empty,
139 filename, line+1, column+1);
140 if (last == null)
141 {
142 pair = cur;
143 obj = cur;
144 }
145 else if (last.car instanceof Keyword)
146 {
147 Object name = new QuoteExp(((Keyword) last.car).getName());
148 last.car
149 = new PairWithPosition(last, MakeAttribute.makeAttribute,
150 new PairWithPosition(last, name, cur));
151 continue;
152 }
153 else
154 last.cdr = cur;
155 last = cur;
156 }
157 if (! forceList)
158 {
159 if (obj == last)
160 obj = last.car;
161 else if (last == null)
162 obj = QuoteExp.voidExp;
163 }
164 return obj;
165 }
166
167 public static Object readObject(InPort port)
168 throws java.io.IOException , SyntaxException
169 {
170 return (new Q2Read(port)).readObject();
171 }
172
173
174 String expressionStartFile;
175 int expressionStartLine;
176 int expressionStartColumn;
177
178 void saveExpressionStartPosition()
179 {
180 expressionStartFile = port.getName();
181 expressionStartLine = port.getLineNumber();
182 expressionStartColumn = port.getColumnNumber();
183 }
184 }
185
186 class Q2ReaderParens extends ReaderDispatchMisc
187 {
188 public Object read (Lexer in, int ch, int count)
189 throws java.io.IOException , SyntaxException
190 {
191 Q2Read reader = (Q2Read) in;
192 char saveReadState = reader.pushNesting('(');
193 try
194 {
195 Object result = reader.readCommand(true);
196
197 LineBufferedReader port = reader.getPort();
198 if (port.read() != ')')
199 reader.error("missing ')'");
200 return result;
201 }
202 finally
203 {
204 reader.popNesting(saveReadState);
205 }
206 }
207
208 }
209 |
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