Method eval

src/bsh/Interpreter.java:627–738

( 
		Reader in, NameSpace nameSpace, String sourceFileInfo
			/*, CallStack callstack */ )

	*/

	public Object eval( 
		Reader in, NameSpace nameSpace, String sourceFileInfo
			/*, CallStack callstack */ ) 
		throws EvalError 
	{
		Object retVal = null;
		if ( Interpreter.DEBUG ) debug("eval: nameSpace = "+nameSpace);

		/* 
			Create non-interactive local interpreter for this namespace
			with source from the input stream and out/err same as 
			this interpreter.
		*/
		Interpreter localInterpreter = 
			new Interpreter( 
				in, out, err, false, nameSpace, this, sourceFileInfo  );

		CallStack callstack = new CallStack( nameSpace );

		SimpleNode node = null;
		boolean eof = false;
		while(!eof)
		{
			try
			{
				eof = localInterpreter.Line();
				if (localInterpreter.get_jjtree().nodeArity() > 0)
				{
					if( node != null )
						node.lastToken.next = null;  // prevent OutOfMemoryError

					node = (SimpleNode)localInterpreter.get_jjtree().rootNode();
					// quick filter for when we're running as a compiler only
					if ( getSaveClasses()
						&& !(node instanceof BSHClassDeclaration)
						&& !(node instanceof BSHImportDeclaration )
						&& !(node instanceof BSHPackageDeclaration )
					)
						continue;

					// nodes remember from where they were sourced
					node.setSourceFile( sourceFileInfo );

					if ( TRACE )
						println( "// " +node.getText() );

					retVal = node.eval( callstack, localInterpreter );

					// sanity check during development
					if ( callstack.depth() > 1 )
						throw new InterpreterError(
							"Callstack growing: "+callstack);

					if ( retVal instanceof ReturnControl ) {
						retVal = ((ReturnControl)retVal).value;
						break; // non-interactive, return control now
					}