System.Xml.Xsl.IlGen.OptimizerPatterns.AddPattern C# (CSharp) Method

        public void AddPattern(OptimizerPatternName pattern) {
            Debug.Assert(Enum.IsDefined(typeof(OptimizerPatternName), pattern));
            Debug.Assert((int) pattern < 32);
            Debug.Assert(!this.isReadOnly, "This OptimizerPatterns instance is read-only.");
            this.patterns |= (1 << (int) pattern);
        }

        /// <summary>
        /// Get OptimizerPatterns annotation for the specified node.  Lazily create if necessary.
        /// </summary>
        public static OptimizerPatterns Read(QilNode nd)
        {
            XmlILAnnotation   ann     = nd.Annotation as XmlILAnnotation;
            OptimizerPatterns optPatt = (ann != null) ? ann.Patterns : null;

            if (optPatt == null)
            {
                if (!nd.XmlType.MaybeMany)
                {
                    // Expressions with ZeroOrOne cardinality should always report IsDocOrderDistinct and NoContainedNodes
                    if (s_zeroOrOneDefault == null)
                    {
                        optPatt = new OptimizerPatterns();
                        optPatt.AddPattern(OptimizerPatternName.IsDocOrderDistinct);
                        optPatt.AddPattern(OptimizerPatternName.SameDepth);
                        optPatt._isReadOnly = true;

                        s_zeroOrOneDefault = optPatt;
                    }
                    else
                    {
                        optPatt = s_zeroOrOneDefault;
                    }
                }
                else if (nd.XmlType.IsDod)
                {
                    if (s_dodDefault == null)
                    {
                        optPatt = new OptimizerPatterns();
                        optPatt.AddPattern(OptimizerPatternName.IsDocOrderDistinct);
                        optPatt._isReadOnly = true;

                        s_dodDefault = optPatt;
                    }
                    else
                    {
                        optPatt = s_dodDefault;
                    }
                }
                else
                {
                    if (s_maybeManyDefault == null)
                    {
                        optPatt             = new OptimizerPatterns();
                        optPatt._isReadOnly = true;

                        s_maybeManyDefault = optPatt;
                    }
                    else
                    {
                        optPatt = s_maybeManyDefault;
                    }
                }
            }

            return(optPatt);
        }