/jEdit/tags/jedit-4-0-pre5/bsh/BSHType.java

/*****************************************************************************
 *                                                                           *
 *  This file is part of the BeanShell Java Scripting distribution.          *
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 *  Sun Public License Notice:                                               *
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 *  The contents of this file are subject to the Sun Public License Version  *
 *  1.0 (the "License"); you may not use this file except in compliance with *
 *  the License. A copy of the License is available at http://www.sun.com    * 
 *                                                                           *
 *  The Original Code is BeanShell. The Initial Developer of the Original    *
 *  Code is Pat Niemeyer. Portions created by Pat Niemeyer are Copyright     *
 *  (C) 2000.  All Rights Reserved.                                          *
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 *  GNU Public License Notice:                                               *
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 *                                                                           *
 *  Patrick Niemeyer (pat@pat.net)                                           *
 *  Author of Learning Java, O'Reilly & Associates                           *
 *  http://www.pat.net/~pat/                                                 *
 *                                                                           *
 *****************************************************************************/


package bsh;

import java.lang.reflect.Array;

class BSHType extends SimpleNode 
	implements BshClassManager.Listener
{
	/**
		baseType is used during evaluation of full type and retained for the
		case where we are an array type.
		In the case where we are not an array this will be the same as type.
	*/
	private Class baseType;
	/** 
		If we are an array type this will be non zero and indicate the 
		dimensionality of the array.  e.g. 2 for String[][];
	*/
    private int arrayDims;

	/** 
		Internal cache of the fully expressed type. 
		i.e. primtive, class, or array.  Cleared on classloader change.
	*/
    private Class type;

    BSHType(int id) { 
		super(id); 
		BshClassManager.addCMListener(this);
	}

	/**
		Used by the grammar to indicate dimensions of array types 
		during parsing.
	*/
    public void addArrayDimension() { 
		arrayDims++; 
	}

    /**
		 Returns a class for the type
	*/
    public Class getType( NameSpace namespace ) 
		throws EvalError
    {
        // return cached type if available
		if (type != null)
			return type;

        //  first node will either be PrimitiveType or AmbiguousName
        SimpleNode node = (SimpleNode)jjtGetChild(0);

        if(node instanceof BSHPrimitiveType)
            baseType = ((BSHPrimitiveType)node).getType();
        else 
            baseType = ((BSHAmbiguousName)node).toClass( namespace );

        if(arrayDims > 0) {
            try {
                // Get the type by constructing a prototype array with
				// arbitrary (zero) length in each dimension.
                int[] dims = new int[arrayDims]; // int array default zeros
                Object obj = Array.newInstance(baseType, dims);
                type = obj.getClass(); 
            } catch(Exception e) {
                throw new EvalError("Couldn't construct array type", this);
            }
        } else
            type = baseType;

        return type;
    }

	/**
		baseType is used during evaluation of full type and retained for the
		case where we are an array type.
		In the case where we are not an array this will be the same as type.
	*/
	public Class getBaseType() {
		return baseType;
	}
	/** 
		If we are an array type this will be non zero and indicate the 
		dimensionality of the array.  e.g. 2 for String[][];
	*/
	public int getArrayDims() {
		return arrayDims;
	}

	public void classLoaderChanged() {
		type = null;
		baseType = null;
	}
}