System.Xml.Xsl.Qil.QilPatternFactory.Filter C# (CSharp) Method

        public QilNode Filter(QilIterator variable, QilNode expr) {
            if (! debug) {
                //((Filter (For $Binding) (True ) ) => ($binding))
                if (expr.NodeType == QilNodeType.True) {
                    return variable.Binding;
                }
                // The following optimization is not safe if the iterator has side effects
                //((Filter (For $Binding) (False) ) => (Sequence))
            }
            return f.Filter(variable, expr);
        }