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1 package gnu.xquery.util;
2 import gnu.kawa.functions.Convert;
3 import gnu.bytecode.*;
4 import gnu.expr.*;
5 import gnu.kawa.xml.*;
6 import gnu.kawa.reflect.Invoke;
7 import gnu.kawa.reflect.OccurrenceType;
8 import gnu.mapping.Values;
9
10 public class CastAs extends Convert
11 {
12 public static final CastAs castAs = new CastAs();
13
14 public Object  apply2 (Object arg1, Object arg2)
15 {
16 Type type = (Type) arg1;
17 if (type instanceof XDataType)
18 return ((XDataType) type).cast(arg2);
19 if (type instanceof OccurrenceType)
20 {
21 OccurrenceType occ = (OccurrenceType) type;
22 Type base = occ.getBase();
23 if (base instanceof XDataType)
24 {
25 int min = occ.minOccurs();
26 int max = occ.maxOccurs();
27 if (arg2 instanceof Values)
28 {
29 if (arg2 == Values.empty && min == 0)
30 return arg2;
31 Values vals = (Values) arg2;
32 int pos = vals.startPos();
33 int n = 0;
34 Values result = new Values();
35 for (;;)
36 {
37 pos = vals.nextPos(pos);
38 if (pos == 0)
39 {
40 if (n >= min && (max < 0 || n <= max))
41 return result.canonicalize();
42 break;
43 }
44 Object value = vals.getPosPrevious(pos);
45 value = ((XDataType) base).cast(value);
46 result.writeObject(value);
47 n++;
48 }
49 }
50 else
51 {
52 if (min <= 1 && max != 0)
53 return ((XDataType) base).cast(arg2);
54 }
55 throw new ClassCastException ("cannot cast "+arg2
56 +" to "+arg1);
57 }
58 }
59 return super.apply2(arg1, arg2);
60 }
61
62 static final ClassType typeXDataType =
63 ClassType.make("gnu.kawa.xml.XDataType");
64 static final Method castMethod = typeXDataType.getDeclaredMethod("cast", 1);
65
66 public Expression inline (ApplyExp exp, ExpWalker walker)
67 {
68 exp = Invoke.inlineClassName(exp, 0, (InlineCalls) walker);
69 Expression[] args = exp.getArgs();
70 if (args.length != 2 || ! (args[0] instanceof QuoteExp))
71 return exp;
72 Object type = ((QuoteExp) args[0]).getValue();
73 if (type instanceof XDataType)
74 {
75 XDataType xtype = (XDataType) type;
76 return new ApplyExp(castMethod, args);
77 }
78 return exp;
79 }
80
81 public void compile (ApplyExp exp, Compilation comp, Target target)
82 {
83 ApplyExp.compile(exp, comp, target);
84 }
85 }
86 |
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