01: /*****************************************************************************
02: * *
03: * This file is part of the BeanShell Java Scripting distribution. *
04: * Documentation and updates may be found at http://www.beanshell.org/ *
05: * *
06: * Sun Public License Notice: *
07: * *
08: * The contents of this file are subject to the Sun Public License Version *
09: * 1.0 (the "License"); you may not use this file except in compliance with *
10: * the License. A copy of the License is available at http://www.sun.com *
11: * *
12: * The Original Code is BeanShell. The Initial Developer of the Original *
13: * Code is Pat Niemeyer. Portions created by Pat Niemeyer are Copyright *
14: * (C) 2000. All Rights Reserved. *
15: * *
16: * GNU Public License Notice: *
17: * *
18: * Alternatively, the contents of this file may be used under the terms of *
19: * the GNU Lesser General Public License (the "LGPL"), in which case the *
20: * provisions of LGPL are applicable instead of those above. If you wish to *
21: * allow use of your version of this file only under the terms of the LGPL *
22: * and not to allow others to use your version of this file under the SPL, *
23: * indicate your decision by deleting the provisions above and replace *
24: * them with the notice and other provisions required by the LGPL. If you *
25: * do not delete the provisions above, a recipient may use your version of *
26: * this file under either the SPL or the LGPL. *
27: * *
28: * Patrick Niemeyer (pat@pat.net) *
29: * Author of Learning Java, O'Reilly & Associates *
30: * http://www.pat.net/~pat/ *
31: * *
32: *****************************************************************************/package bsh;
33:
34: class BSHIfStatement extends SimpleNode {
35: BSHIfStatement(int id) {
36: super (id);
37: }
38:
39: public Object eval(CallStack callstack, Interpreter interpreter)
40: throws EvalError {
41: Object ret = null;
42:
43: if (evaluateCondition((SimpleNode) jjtGetChild(0), callstack,
44: interpreter))
45: ret = ((SimpleNode) jjtGetChild(1)).eval(callstack,
46: interpreter);
47: else if (jjtGetNumChildren() > 2)
48: ret = ((SimpleNode) jjtGetChild(2)).eval(callstack,
49: interpreter);
50:
51: if (ret instanceof ReturnControl)
52: return ret;
53: else
54: return Primitive.VOID;
55: }
56:
57: public static boolean evaluateCondition(SimpleNode condExp,
58: CallStack callstack, Interpreter interpreter)
59: throws EvalError {
60: Object obj = condExp.eval(callstack, interpreter);
61: if (obj instanceof Primitive) {
62: if (obj == Primitive.VOID)
63: throw new EvalError("Condition evaluates to void type",
64: condExp, callstack);
65: obj = ((Primitive) obj).getValue();
66: }
67:
68: if (obj instanceof Boolean)
69: return ((Boolean) obj).booleanValue();
70: else
71: throw new EvalError(
72: "Condition must evaluate to a Boolean or boolean.",
73: condExp, callstack);
74: }
75: }
|