|
1
4 package gnu.xquery.util;
5 import gnu.mapping.*;
6 import gnu.lists.*;
7 import gnu.math.Numeric;
8 import gnu.math.RealNum;
9 import gnu.kawa.xml.UntypedAtomic;
10 import gnu.expr.*;
11 import gnu.bytecode.Type;
12 import gnu.kawa.xml.XDataType;
13 import gnu.xquery.lang.XQuery;
14
15 public class BooleanValue extends Procedure1 implements CanInline
16 {
17 public static final BooleanValue booleanValue =
18 new BooleanValue("boolean-value");
19
20 public BooleanValue (String  name)
21 {
22 super(name);
23 }
24
25 public static boolean booleanValue(Object value)
26 {
27 if (value instanceof Boolean )
28 return ((Boolean ) value).booleanValue();
29 if (value instanceof Number
30 && (value instanceof RealNum || ! (value instanceof Numeric)))
31 {
32 double d = ((Number ) value).doubleValue();
33 return d != 0 && ! Double.isNaN(d);
34 }
35 if (value instanceof SeqPosition)
36 return true;
37 if (value instanceof String
38
39 || value instanceof java.net.URI
40
41 || value instanceof UntypedAtomic)
42 return value.toString().length() > 0;
43 if (value instanceof Values)
44 {
45 Values values = (Values) value;
46 Object value1 = values.getPosNext(0);
47 if (value1 == Sequence.eofValue)
48 return false;
49 int next = values.nextDataIndex(0);
50 if (next < 0)
51 return booleanValue(value1);
52 if (value1 instanceof SeqPosition)
53 return true;
54 }
55 throw new WrongType("fn:boolean", 1, value, "boolean-convertible-value");
56 }
57
58 public static boolean not(Object value)
59 {
60 return ! booleanValue(value);
61 }
62
63 public Object apply1(Object arg)
64 {
65 return booleanValue(arg) ? Boolean.TRUE : Boolean.FALSE;
66 }
67
68 public Expression inline (ApplyExp exp, ExpWalker walker)
69 {
70 Expression[] args = exp.getArgs();
71 if (args.length == 1)
72 {
73 Expression arg = args[0];
74 Type type = arg.getType();
75 if (type == XDataType.booleanType)
76 return arg;
77 if (type == null)
78 exp.setType(XDataType.booleanType);
79 if (arg instanceof QuoteExp)
80 {
81 Object value = ((QuoteExp) arg).getValue();
82 try
83 {
84 return booleanValue(value) ? XQuery.trueExp : XQuery.falseExp;
85 }
86 catch (Throwable ex)
87 {
88 String message = "cannot convert to a boolean";
89 walker.getMessages().error('e', message);
90 return new ErrorExp(message);
91 }
92 }
93 }
94 return exp;
95 }
96 }
97 |
Popular Tags |
Java API By Example, From Geeks To Geeks.