Method eval

src/bsh/BSHSwitchStatement.java:35–101

( CallStack callstack, Interpreter interpreter )

	public BSHSwitchStatement(int id) { super(id); }

    public Object eval( CallStack callstack, Interpreter interpreter )
		throws EvalError
	{
		int numchild = jjtGetNumChildren();
		int child = 0;
		SimpleNode switchExp = ((SimpleNode)jjtGetChild(child++));
		Object switchVal = switchExp.eval( callstack, interpreter );

		/*
			Note: this could be made clearer by adding an inner class for the
			cases and an object context for the child traversal.
		*/
		// first label
		BSHSwitchLabel label;
		Object node;
		ReturnControl returnControl=null;

		// get the first label
		if ( child >= numchild )
			throw new EvalError("Empty switch statement.", this, callstack );
		label = ((BSHSwitchLabel)jjtGetChild(child++));

		// while more labels or blocks and haven't hit return control
		while ( child < numchild && returnControl == null ) 
		{
			// if label is default or equals switchVal
			if ( label.isDefault 
				|| primitiveEquals( 
					switchVal, label.eval( callstack, interpreter ), 
					callstack, switchExp )
				)
			{
				// execute nodes, skipping labels, until a break or return
				while ( child < numchild ) 
				{
					node = jjtGetChild(child++);
					if ( node instanceof BSHSwitchLabel )
						continue;
					// eval it
					Object value = 
						((SimpleNode)node).eval( callstack, interpreter ); 

					// should check to disallow continue here?
					if ( value instanceof ReturnControl ) {
						returnControl = (ReturnControl)value;
						break;
					}
				}
			} else 
			{
				// skip nodes until next label
				while ( child < numchild ) 
				{
					node = jjtGetChild(child++);
					if ( node instanceof BSHSwitchLabel ) {
						label = (BSHSwitchLabel)node;
						break;
					}