C# RubyClass.ForEachAncestor方法代码示例

        /// <summary>
        /// There are basically 4 cases:
        /// 1) CLR method of the given name is not defined in the specified type.
        ///    Do nothing, the method will be found as we traverse the hierarhy towards the Kernel module.
        /// 2) Otherwise
        ///    1) There is no RubyMemberInfo of given <c>name</c> present in the (type..Kernel] ancestors.
        ///       We need to search all types in (type..Object] for CLR method overloads.
        ///    2) There is a RubyMemberInfo in a class, say C, in (type..Kernel]. 
        ///       We need to get CLR methods from (type..C) in addition to the members in the type.
        ///        1) C.HidesInheritedOverloads == true
        ///           All overloads of the method we look for are in [type..C).
        ///        2) C.HidesInheritedOverloads == false
        ///           All overloads of the method we look for are in [type..C) and in the RubyMemberInfo.
        /// </summary>
        internal bool TryGetClrMethod(RubyClass/*!*/ cls, Type/*!*/ type, BindingFlags bindingFlags, string/*!*/ name, string/*!*/ clrName, out RubyMemberInfo method) {

            // declared only:
            MemberInfo[] initialMembers = GetDeclaredClrMethods(type, bindingFlags, clrName);
            int initialVisibleMemberCount = GetVisibleMethodCount(initialMembers);
            if (initialVisibleMemberCount == 0) {
                // case [1]
                method = null;
                return false;
            }

            // inherited overloads:
            List<RubyClass> ancestors = new List<RubyClass>();
            RubyMemberInfo inheritedRubyMember = null;
            bool skipHidden = false;

            cls.ForEachAncestor((module) => {
                if (module != cls) {
                    if (module.TryGetDefinedMethod(name, ref skipHidden, out inheritedRubyMember) && !inheritedRubyMember.IsSuperForwarder) {
                        return true;
                    }

                    // Skip classes that have no tracker, e.g. Fixnum(tracker) <: Integer(null) <: Numeric(null) <: Object(tracker).
                    // Skip interfaces, their methods are not callable => do not include them into a method group.
                    // Skip all classes once hidden sentinel is encountered (no CLR overloads are visible since then).
                    if (!skipHidden && module.TypeTracker != null && module.IsClass) {
                        ancestors.Add((RubyClass)module);
                    }
                }

                // continue:
                return false;
            });

            _allMethods = null;
            if (inheritedRubyMember != null) {
                // case [2.2.2]: add CLR methods from the Ruby member:
                var inheritedGroup = inheritedRubyMember as RubyMethodGroupInfo;
                if (inheritedGroup != null) {
                    AddMethodsOverwriteExisting(inheritedGroup.MethodBases, inheritedGroup.OverloadOwners);
                }
            }

            // populate classes in (type..Kernel] or (type..C) with method groups:
            for (int i = ancestors.Count - 1; i >= 0; i--) {
                var declared = GetDeclaredClrMethods(ancestors[i].TypeTracker.Type, bindingFlags, clrName);
                if (declared.Length != 0 && AddMethodsOverwriteExisting(declared, null)) {
                    // There is no cached method that needs to be invalidated.
                    //
                    // Proof:
                    // Suppose the group being created here overridden an existing method that is cached in a dynamic site invoked on some target class.
                    // Then either the target class is above all ancestors[i] or below some. If it is above then the new group doesn't 
                    // invalidate validity of the site. If it is below then the method resolution for the cached method would create
                    // and store to method tables all method groups in between the target class and the owner of the cached method, including the 
                    // one that contain overloads of ancestors[i]. But no module below inheritedRubyMember contains a method group of the name 
                    // being currently resolved.
                    ancestors[i].AddMethodNoCacheInvalidation(name, MakeAllMethodsGroup(ancestors[i]));
                }
            }

            if (_allMethods != null) {
                // add members declared in self:
                AddMethodsOverwriteExisting(initialMembers, null);

                // return the group, it will be stored in the method table by the caller:
                method = MakeAllMethodsGroup(cls);
            } else {
                method = MakeSingleOwnerGroup(cls, initialMembers, initialVisibleMemberCount);
            }

            return true;
        }

        private bool IsMethodVisible(RubyMemberInfo/*!*/ method, RubyModule/*!*/ owner, RubyClass visibilityContext, bool foundCallerSelf) {
            // call with implicit self => all methods are visible
            if (visibilityContext == RubyClass.IgnoreVisibility) {
                return true;
            } 
            
            if (method.Visibility == RubyMethodVisibility.Protected) {
                // A protected method is visible if the caller's self immediate class is a descendant of the method owner.
                if (foundCallerSelf) {
                    return true;
                }
                // walk ancestors from caller's self class (visibilityContext)
                // until the method owner is found or this module is found (this module is a descendant of the owner):
                return visibilityContext.ForEachAncestor((module) => module == owner || module == this);
            } 

            return method.Visibility == RubyMethodVisibility.Public;
        }