/jEdit/tags/jedit-4-2-pre4/bsh/BSHMethodDeclaration.java

/*****************************************************************************
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 *  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/                                                 *
 *                                                                           *
 *****************************************************************************/


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;
	// Unsafe caching of type here.
	Object returnType; 	// null (none), Primitive.VOID, or a Class

	Modifiers modifiers;
	int numThrows = 0;

	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.
	*/
	public Object eval( CallStack callstack, Interpreter interpreter )
		throws EvalError
	{
		if ( block == null ) 
			evalNodes( callstack, interpreter );

		// 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 namespace = callstack.top();
		BshMethod bshMethod = new BshMethod( this, namespace, modifiers );
		try {
			namespace.setMethod( name, bshMethod );
		} catch ( UtilEvalError e ) {
			throw e.toEvalError(this,callstack);
		}

		return Primitive.VOID;
	}

	private void evalNodes( CallStack callstack, Interpreter interpreter ) 
		throws EvalError
	{
		// We will allow methods to be re-written.
		/*  
		if( namespace has method )
			throw new EvalError(
			"Method: " + name + " already defined in scope", this);
		*/

		Object firstNode = jjtGetChild(0);
		int firstThrows = 1;
		if ( firstNode instanceof BSHReturnType )
		{
			returnType = ((BSHReturnType)firstNode).getReturnType( 
				callstack, interpreter );
			params = (BSHFormalParameters)jjtGetChild(1);
			block = (BSHBlock)jjtGetChild(2+numThrows); // skip throws
			++firstThrows;
		}
		else
		{
			params = (BSHFormalParameters)jjtGetChild(0);
			block = (BSHBlock)jjtGetChild(1+numThrows); // skip throws
		}
		
		// validate that the throws names are class names
		for(int i=firstThrows; i<numThrows+firstThrows; i++)
			((BSHAmbiguousName)jjtGetChild(i)).toClass( 
				callstack, interpreter );

		params.eval( callstack, interpreter );

		// if strictJava mode, check for loose parameters and return type
		if ( interpreter.getStrictJava() )
		{
			for(int i=0; i<params.argTypes.length; i++)
				if ( params.argTypes[i] == null )
					// Warning: Null callstack here.  Don't think we need
					// a stack trace to indicate how we sourced the method.
					throw new EvalError(
				"(Strict Java Mode) Undeclared argument type, parameter: " +
					params.argNames[i] + " in method: " 
					+ name, this, null );

			if ( returnType == null )
				// Warning: Null callstack here.  Don't think we need
				// a stack trace to indicate how we sourced the method.
				throw new EvalError(
				"(Strict Java Mode) Undeclared return type for method: "
					+ name, this, null );
		}
	}

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