System.Xml.Xsl.IlGen.XmlILVisitor.VisitLength C# (CSharp) Method

        protected override QilNode VisitLength(QilUnary ndSetLen) {
            Label lblOnEnd = this.helper.DefineLabel();
            OptimizerPatterns patt = OptimizerPatterns.Read(ndSetLen);

            if (CachesResult(ndSetLen.Child)) {
                NestedVisitEnsureStack(ndSetLen.Child);
                this.helper.CallCacheCount(this.iterNested.Storage.ItemStorageType);
            }
            else {
                // length = 0;
                this.helper.Emit(OpCodes.Ldc_I4_0);

                StartNestedIterator(ndSetLen.Child, lblOnEnd);

                // foreach (item in expr) {
                Visit(ndSetLen.Child);

                // Pop values of SetLength expression from the stack if necessary
                this.iterCurr.EnsureNoCache();
                this.iterCurr.DiscardStack();

                // length++;
                this.helper.Emit(OpCodes.Ldc_I4_1);
                this.helper.Emit(OpCodes.Add);

                if (patt.MatchesPattern(OptimizerPatternName.MaxPosition)) {
                    // Short-circuit rest of loop if max position has been exceeded
                    this.helper.Emit(OpCodes.Dup);
                    this.helper.LoadInteger((int) patt.GetArgument(OptimizerPatternArgument.MaxPosition));
                    this.helper.Emit(OpCodes.Bgt, lblOnEnd);
                }

                // }
                this.iterCurr.LoopToEnd(lblOnEnd);

                EndNestedIterator(ndSetLen.Child);
            }

            this.iterCurr.Storage = StorageDescriptor.Stack(typeof(int), false);

            return ndSetLen;
        }