|
1
4 package gnu.kawa.reflect;
5 import gnu.bytecode.*;
6 import gnu.mapping.Procedure;
7 import gnu.mapping.Values;
8 import gnu.lists.*;
9 import java.io.*;
10 import gnu.expr.*;
11
12
13
14 public class OccurrenceType extends ObjectType
15 implements Externalizable, TypeValue
16 {
17 Type base;
18 int minOccurs;
19 int maxOccurs;
20
21 public Type getBase () { return base; }
22 public int minOccurs() { return minOccurs; }
23 public int maxOccurs() { return maxOccurs; }
24
25 public OccurrenceType (Type base, int minOccurs, int maxOccurs)
26 {
27 this.base = base;
28 this.minOccurs = minOccurs;
29 this.maxOccurs = maxOccurs;
30 }
31
32 public static Type getInstance (Type base, int minOccurs, int maxOccurs)
33 {
34 if (minOccurs == 1 && maxOccurs == 1)
35 return base;
36 if (minOccurs == 0 && maxOccurs < 0
37 && (base == SingletonType.instance || base == Type.pointer_type))
38 return Type.pointer_type;
39 return new OccurrenceType(base, minOccurs, maxOccurs);
40 }
41
42 public static final Type emptySequenceType =
43 OccurrenceType.getInstance(SingletonType.instance, 0, 0);
44
45 public Type getImplementationType()
46 {
47 return Type.pointer_type;
48 }
49
50 public int compare(Type other)
51 {
52 if (other instanceof OccurrenceType)
53 {
54 OccurrenceType occOther = (OccurrenceType) other;
55 if (minOccurs == occOther.minOccurs
56 && maxOccurs == occOther.maxOccurs)
57 return base.compare(occOther.getBase());
58 }
59
64 return -2;
65 }
66
67 public Object  coerceFromObject (Object obj)
68 {
69 if (obj instanceof Values)
70 {
71 }
72 else
73 {
74 if (minOccurs <= 1 && maxOccurs != 0)
76 return base.coerceFromObject(obj);
77 }
78 if (! isInstance(obj))
80 throw new ClassCastException ();
81 return obj;
82 }
83
84 public boolean isInstance (Object obj)
85 {
86 if (obj instanceof Values)
87 {
88 Values vals = (Values) obj;
89 int pos = vals.startPos();
90 int n = 0;
91 if (base instanceof ElementPredicate)
92 {
93 ElementPredicate pred = (ElementPredicate) base;
94 for (;;)
95 {
96 boolean matches;
97 matches = pred.isInstancePos(vals, pos);
98 pos = vals.nextPos(pos);
99 if (pos == 0)
100 {
101 return n >= minOccurs
102 && (maxOccurs < 0 || n <= maxOccurs);
103 }
104 if (! matches)
105 return false;
106 n++;
107 }
108 }
109 else
110 {
111
112 for (;;)
113 {
114 pos = vals.nextPos(pos);
115 if (pos == 0)
116 {
117 return n >= minOccurs
118 && (maxOccurs < 0 || n <= maxOccurs);
119 }
120 Object value = vals.getPosPrevious(pos);
121 if (! base.isInstance(value))
122 return false;
123 n++;
124 }
125 }
126 }
127 else
128 {
129 if (minOccurs > 1 || maxOccurs == 0)
130 return false;
131 return base.isInstance(obj);
132 }
133 }
134
135 public void emitTestIf(Variable incoming, Declaration decl,
136 Compilation comp)
137 {
138 CodeAttr code = comp.getCode();
139 if (incoming != null)
140 code.emitLoad(incoming);
141 if (decl != null)
142 {
143 code.emitDup();
144 decl.compileStore(comp);
145 }
146 comp.compileConstant(this);
147 code.emitSwap();
148 code.emitInvokeVirtual(isInstanceMethod);
149 code.emitIfIntNotZero();
150 }
151
152 public void emitIsInstance(Variable incoming,
153 Compilation comp, Target target)
154 {
155 gnu.kawa.reflect.InstanceOf.emitIsInstance(this, incoming, comp, target);
156 }
157
158 public Procedure getConstructor ()
159 {
160 return null;
161 }
162
163
167 public static int itemCountRange (Type type)
168 {
169 if (type instanceof SingletonType)
170 return (1 << 12) | 1;
171 if (type instanceof OccurrenceType)
172 {
173 OccurrenceType occ = (OccurrenceType) type;
174 int min = occ.minOccurs();
175 int max = occ.maxOccurs();
176 int bnum = itemCountRange(occ.getBase());
177 if ((min == 1 && max == 1)
178 || bnum == 0)
179 return bnum;
180 if (max > 0xfffff)
181 max = -1;
182 if (max == 0)
183 return 0;
184 int bmin = bnum & 0xfff;
185 int bmax = bnum >> 12;
186 if (bnum != 0x1001)
187 {
188 if (min > 0xfff)
189 min = 0xfff;
190 min = min * bmin;
191 if (min > 0xfff)
192 min = 0xfff;
193 if (max < 0 || bmax < 0)
194 max = -1;
195 else
196 max = max * bmax;
197 if (max > 0xfffff)
198 max = -1;
199 }
200 return (max << 12) | min;
201 }
202 if (type instanceof PrimType)
203 return type.isVoid() ? 0 : 0x1001;
204 if (type instanceof ArrayType)
205 return 0x1001;
206 if (type instanceof ObjectType)
207 {
208 int cmp = type.compare(Compilation.typeValues);
209 if (cmp == -3)
210 return 0x1001;
211 }
212 return -1 << 12;
213 }
214
215
222 public static char itemCountCode (Type type)
223 {
224 int num = itemCountRange(type);
225 int min = num & 0xFFF;
226 int max = num >> 12;
227 return max == 0 ? '0'
228 : min == 0 ? (max == 1 ? '?' : '*')
229 : min == 1 && max == 1 ? '1' : '+';
230 }
231
232 public static boolean itemCountIsZeroOrOne (Type type)
233 {
234 return (itemCountRange(type) >> 13) == 0;
236 }
237
238 public static boolean itemCountIsOne (Type type)
239 {
240 return itemCountRange(type) == 0x1001;
241 }
242
243
245 public static Type itemPrimeType (Type type)
246 {
247 while (type instanceof OccurrenceType)
248 type = ((OccurrenceType) type).getBase();
249 return itemCountIsOne(type) ? type : SingletonType.instance;
250
251 }
252
253 public void writeExternal(ObjectOutput out) throws IOException
254 {
255 out.writeObject(base);
256 out.writeInt(minOccurs);
257 out.writeInt(maxOccurs);
258 }
259
260 public String toString ()
261 {
262 String b = base.toString();
263 boolean parens = b == null || b.indexOf(' ') >= 0;
264 StringBuffer sbuf = new StringBuffer ();
265 if (parens)
266 sbuf.append('(');
267 sbuf.append(b);
268 if (parens)
269 sbuf.append(')');
270 if (minOccurs == 1 && maxOccurs == 1)
271 ;
272 else if (minOccurs == 0 && maxOccurs == 1)
273 sbuf.append('?');
274 else if (minOccurs == 1 && maxOccurs == -1)
275 sbuf.append('+');
276 else if (minOccurs == 0 && maxOccurs == -1)
277 sbuf.append('*');
278 else
279 {
280 sbuf.append('{');
281 sbuf.append(minOccurs);
282 sbuf.append(',');
283 if (maxOccurs >= 0)
284 sbuf.append(maxOccurs);
285 else
286 sbuf.append('*');
287 sbuf.append('}');
288 }
289 return sbuf.toString();
290 }
291
292 public void readExternal(ObjectInput in)
293 throws IOException, ClassNotFoundException
294 {
295 base = (Type) in.readObject();
296 minOccurs = in.readInt();
297 maxOccurs = in.readInt();
298 }
299
300 public static final ClassType typeOccurrenceType
301 = ClassType.make("gnu.kawa.reflect.OccurrenceType");
302 static final Method isInstanceMethod
303 = typeOccurrenceType.getDeclaredMethod("isInstance", 1);
304 }
305 |
Popular Tags |
Java API By Example, From Geeks To Geeks.