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/jEdit/tags/jedit-4-0-pre3/bsh/BlockNameSpace.java

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Java | 77 lines | 18 code | 8 blank | 51 comment | 2 complexity | e895356117caa8ef99101247d45d8bd8 MD5 | raw file
 1/*****************************************************************************
 2 *                                                                           *
 3 *  This file is part of the BeanShell Java Scripting distribution.          *
 4 *  Documentation and updates may be found at http://www.beanshell.org/      *
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 6 *  Sun Public License Notice:                                               *
 7 *                                                                           *
 8 *  The contents of this file are subject to the Sun Public License Version  *
 9 *  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 *
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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 *****************************************************************************/
33
34
35package	bsh;
36
37/**
38    A specialized namespace	for Blocks, e.g. the body of a "for" statement.
39	The Block acts like a child namespace but only for typed variables 
40	declared within it.  Elsewhere variable assignment (including untyped
41	variable usage) acts like it is part of the containing block.  
42	<p>
43
44	Note: It *must* remain possible for a BlockNameSpace to be a child of
45	another BlockNameSpace and have variable propogation pass all the way
46	through.  (This happens naturally and simply here). This is used in 
47	BSHForStatement (see notes there).
48*/
49class BlockNameSpace extends NameSpace 
50{
51
52    public BlockNameSpace( NameSpace parent ) 
53		throws EvalError
54	{
55		super( parent, parent.name + "/BlockNameSpace" );
56    }
57
58	/**
59		Override the standard namespace behavior.
60		If the variables exists in our namespace assign it there,
61		otherwise in the parent space.
62		i.e. only allow typed var declaration to happen in this namespace.
63		Typed vars are handled in the ordinary way... local scope.
64	*/
65    public void	setVariable(String name, Object	o) throws EvalError {
66		if ( weHaveVar( name ) ) 
67			super.setVariable( name, o );
68		else
69			getParent().setVariable( name, o );
70    }
71
72	boolean weHaveVar( String name ) {
73		return super.getVariableImpl( name, false ) != null;
74	}
75
76}
77