MegaBites-AI/Windows-powershell

1// Copyright (c) Microsoft Corporation.2// Licensed under the MIT License.3 4using System.Collections;5using System.Collections.Generic;6 7namespace System.Management.Automation8{9    internal sealed class SessionStateScopeEnumerator : IEnumerator<SessionStateScope>, IEnumerable<SessionStateScope>10    {11        /// <summary>12        /// Constructs an enumerator for enumerating through the session state scopes13        /// using the appropriate scoping rules (default to dynamic scoping).14        /// </summary>15        /// <param name="scope">16        ///   The starting scope to start the enumeration from.17        /// </param>18        internal SessionStateScopeEnumerator(SessionStateScope scope)19        {20            Diagnostics.Assert(scope != null, "Caller to verify scope argument");21            _initialScope = scope;22        }23 24        /// <summary>25        /// Uses the proper scoping rules to get the next scope to do the lookup in.26        /// </summary>27        /// <returns>28        /// True if the enumerator was advanced to the next scope, or false otherwise.29        /// </returns>30        public bool MoveNext()31        {32            // On the first call to MoveNext the enumerator should be before33            // the first scope in the lookup and then advance to the first34            // scope in the lookup35 36            _currentEnumeratedScope = _currentEnumeratedScope == null ? _initialScope : _currentEnumeratedScope.Parent;37 38            // If the current scope is the global scope there is nowhere else39            // to do the lookup, so return false.40            return (_currentEnumeratedScope != null);41        }42 43        /// <summary>44        /// Sets the enumerator to before the first scope.45        /// </summary>46        public void Reset()47        {48            _currentEnumeratedScope = null;49        }50 51        /// <summary>52        /// Gets the current lookup scope.53        /// </summary>54        /// <exception cref="InvalidOperationException">55        /// The enumerator is positioned before the first element of the56        /// collection or after the last element.57        /// </exception>58        SessionStateScope IEnumerator<SessionStateScope>.Current59        {60            get61            {62                if (_currentEnumeratedScope == null)63                {64                    throw PSTraceSource.NewInvalidOperationException();65                }66 67                return _currentEnumeratedScope;68            }69        }70 71        object IEnumerator.Current72        {73            get74            {75                return ((IEnumerator<SessionStateScope>)this).Current;76            }77        }78 79        /// <summary>80        /// Gets the IEnumerator for this class.81        /// </summary>82        /// <returns>83        /// The IEnumerator interface for this class.84        /// </returns>85        System.Collections.Generic.IEnumerator<SessionStateScope> System.Collections.Generic.IEnumerable<SessionStateScope>.GetEnumerator()86        {87            return this;88        }89 90        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()91        {92            return this;93        }94 95        public void Dispose()96        {97            Reset();98        }99 100        private readonly SessionStateScope _initialScope;101        private SessionStateScope _currentEnumeratedScope;102    }103}104