MegaBites-AI/Windows-powershell

1// Copyright (c) Microsoft Corporation.2// Licensed under the MIT License.3 4using System.Dynamic;5using System.Management.Automation.Language;6using System.Runtime.CompilerServices;7 8namespace System.Management.Automation9{10    /// <summary>11    /// Define type for a reference object in PowerShell scripting language.12    /// </summary>13    /// <remarks>14    /// This class is used to describe both kinds of references:15    ///     a. reference to a value: _value will be holding the value being referenced.16    ///     b. reference to a variable: _value will be holding a PSVariable instance for the variable to be referenced.17    ///18    /// A reference is created in following ways,19    ///     a. value reference20    ///         $a = [ref] 321    ///         [ref] $a = 322    ///         [ref] $a = $b23    ///     b. variable reference24    ///         $a = [ref] $b25    /// </remarks>26    public class PSReference27    {28        private object _value;29 30        /// <summary>31        /// Create an instance of PSReference.32        /// </summary>33        /// <param name="value"></param>34        public PSReference(object value)35        {36            _value = value;37        }38 39        /// <summary>40        /// Get and set value of PSReference.41        /// </summary>42        /// <remarks>43        /// If underlining object is a value, the object itself will be operated on.44        /// If underlining object is a variable, the variable will be operated on.45        /// </remarks>46        public object Value47        {48            get49            {50                PSVariable variable = _value as PSVariable;51 52                if (variable != null)53                {54                    return variable.Value;55                }56 57                return _value;58            }59 60            set61            {62                PSVariable variable = _value as PSVariable;63 64                if (variable != null)65                {66                    variable.Value = value;67                    return;68                }69 70                _value = value;71            }72        }73 74        internal static readonly CallSite<Func<CallSite, object, object, object>> CreatePsReferenceInstance =75                CallSite<Func<CallSite, object, object, object>>.Create(PSCreateInstanceBinder.Get(new CallInfo(1), null));76 77        internal static PSReference CreateInstance(object value, Type typeOfValue)78        {79            Type psReferType = typeof(PSReference<>).MakeGenericType(typeOfValue);80            return (PSReference)CreatePsReferenceInstance.Target.Invoke(CreatePsReferenceInstance, psReferType, value);81        }82    }83 84    internal class PSReference<T> : PSReference85    {86        public PSReference(object value) : base(value)87        {88        }89    }90}91