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

/*****************************************************************************
 *                                                                           *
 *  This file is part of the BeanShell Java Scripting distribution.          *
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 *  The contents of this file are subject to the Sun Public License Version  *
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 *  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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 *                                                                           *
 *  Patrick Niemeyer (pat@pat.net)                                           *
 *  Author of Learning Java, O'Reilly & Associates                           *
 *  http://www.pat.net/~pat/                                                 *
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 *****************************************************************************/


package bsh;

import java.util.Vector;

/*
	This shouldn't have to be public.	
	We should add to bsh.This allowing us to invoke a method.
	If we do that we should probably use it in Reflect.java

	Note: caching of the structure is done in BshMethod
	no caching need be done here or in formal param, etc.
*/
class BSHMethodDeclaration extends SimpleNode
{
	String name;
	BSHFormalParameters params;
	BSHBlock block;
	Object returnType; 	// null (none), Primitive.VOID, or a Class

	BSHMethodDeclaration(int id)
	{
		super(id);
	}

	/**
		Evaluate the declaration of the method.  That is, determine the
		structure of the method and install it into the caller's namespace.
	
		Since the structure of the method is only determined by type evaluation
		(through eval of BSHFormalParameters) we do not need the interpreter 
		or callstack.
	*/
	public Object eval( NameSpace namespace )  
		throws EvalError
	{
		if ( block == null ) 
		{
			// We will allow methods to be re-written.
			/*  
			if( namespace has method )
				throw new EvalError(
				"Method: " + name + " already defined in scope", this);
			*/

			if(jjtGetNumChildren() == 3)
			{
				returnType = 
					((BSHReturnType)jjtGetChild(0)).getReturnType( namespace );
				params = (BSHFormalParameters)jjtGetChild(1);
				block = (BSHBlock)jjtGetChild(2);
			}
			else
			{
				params = (BSHFormalParameters)jjtGetChild(0);
				block = (BSHBlock)jjtGetChild(1);
			}
			params.eval( namespace );

			// if strictJava mode, check for loose parameters and return type
			if ( Interpreter.strictJava )
			{
				for(int i=0; i<params.argTypes.length; i++)
					if ( params.argTypes[i] == null )
						throw new EvalError(
					"(Strict Java Mode) Undeclared argument type, parameter: " +
						params.argNames[i] + " in method: " 
						+ name, this );

				if ( returnType == null )
					throw new EvalError(
					"(Strict Java Mode) Undeclared return type for method: "
						+ name, this );
			}
		}

		// Install an *instance* of this method in the namespace.
		// See notes in BshMethod 

// This is not good...
// need a way to update eval without re-installing...
// so that we can re-eval params, etc. when classloader changes
// look into this
		namespace.setMethod( name, new BshMethod( this, namespace ) );

		return Primitive.VOID;
	}

	public String toString() {
		return "MethodDeclaration: "+name;
	}
}