System.Xml.Schema.Compiler.CompileSubstitutionGroup C# (CSharp) Method

        private void CompileSubstitutionGroup(XmlSchemaSubstitutionGroup substitutionGroup) {
            if (substitutionGroup.IsProcessing) {
                foreach (XmlSchemaElement element in substitutionGroup.Members) {
                    SendValidationEvent(Res.Sch_SubstitutionCircularRef, element);
                    return;
                }
            }
            XmlSchemaElement examplar = (XmlSchemaElement)elements[substitutionGroup.Examplar];
            Debug.Assert(examplar != null); //Headelement presence is checked while building subst groups
            if (substitutionGroup.Members.Contains(examplar)) {// already checked
                return;
            }
            substitutionGroup.IsProcessing = true;
            try {
                if (examplar.FinalResolved == XmlSchemaDerivationMethod.All) {
                    SendValidationEvent(Res.Sch_InvalidExamplar, examplar);
                }
                //Build transitive members
                ArrayList newMembers = null;
                foreach (XmlSchemaElement element in substitutionGroup.Members) {
                    //Chain to other head's that are members of this head's substGroup
                    XmlSchemaSubstitutionGroup g = (XmlSchemaSubstitutionGroup)examplars[element.QualifiedName];
                    if (g != null) {
                        CompileSubstitutionGroup(g);
                        foreach (XmlSchemaElement element1 in g.Members) {
                            if (element1 != element) { //Exclude the head
                                if (newMembers == null) {
                                    newMembers = new ArrayList();
                                }
                                newMembers.Add(element1);
                            }
                        }
                    }
                }
                if (newMembers != null) {
                    foreach (XmlSchemaElement newMember in newMembers) {
                        substitutionGroup.Members.Add(newMember);
                    }
                }
                substitutionGroup.Members.Add(examplar); // Compiled mark
            }
            finally {
                substitutionGroup.IsProcessing = false;              
            }
        }