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Java > Open Source Codes > bsh > BSHCastExpression


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33
34
35 package bsh;
36
37 /**
38     Implement casts.
39
40     I think it should be possible to simplify some of the code here by
41     using the Types.getAssignableForm() method, but I haven't looked
42     into it.
43 */
44 class BSHCastExpression extends SimpleNode {
45
46     public BSHCastExpression(int id) { super(id); }
47
48     /**
49         @return the result of the cast.
50     */
51     public Object JavaDoc eval(
52         CallStack callstack, Interpreter interpreter ) throws EvalError
53     {
54         NameSpace namespace = callstack.top();
55         Class JavaDoc toType = ((BSHType)jjtGetChild(0)).getType(
56             callstack, interpreter );
57         SimpleNode expression = (SimpleNode)jjtGetChild(1);
58
59         // evaluate the expression
60 Object JavaDoc fromValue = expression.eval(callstack, interpreter);
61         Class JavaDoc fromType = fromValue.getClass();
62
63         // TODO: need to add isJavaCastable() test for strictJava
64 // (as opposed to isJavaAssignable())
65 try {
66             return Types.castObject( fromValue, toType, Types.CAST );
67         } catch ( UtilEvalError e ) {
68             throw e.toEvalError( this, callstack );
69         }
70     }
71
72 }
73
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