public DekiScriptOutputBuffer.Range Visit(DekiScriptDiscard expr, DekiScriptExpressionEvaluationState state)
        {
            int marker = state.Buffer.Marker;

            try {
                expr.Value.VisitWith(this, state);
            } finally {
                state.Buffer.Reset(marker);
            }
            return(DekiScriptOutputBuffer.Range.Empty);
        }
 public DekiScriptExpression Visit(DekiScriptDiscard expr, DekiScriptExpressionEvaluationState state)
 {
     // TODO (steveb): missing partial evaluation rule
     return(expr);
 }