MegaBites-AI/Windows-powershell

1// Copyright (c) Microsoft Corporation.2// Licensed under the MIT License.3 4using System.Collections.Generic;5using System.Linq;6using System.Reflection;7using System.Runtime.CompilerServices;8 9namespace System.Management.Automation10{11    internal static class ExtensionMethods12    {13        public static void SafeInvoke(this EventHandler eventHandler, object sender, EventArgs eventArgs)14        {15            eventHandler?.Invoke(sender, eventArgs);16        }17 18        public static void SafeInvoke<T>(this EventHandler<T> eventHandler, object sender, T eventArgs) where T : EventArgs19        {20            eventHandler?.Invoke(sender, eventArgs);21        }22    }23 24    internal static class EnumerableExtensions25    {26        internal static IEnumerable<T> Prepend<T>(this IEnumerable<T> collection, T element)27        {28            yield return element;29            foreach (T t in collection)30                yield return t;31        }32 33        internal static int SequenceGetHashCode<T>(this IEnumerable<T> xs)34        {35            // algorithm based on https://stackoverflow.com/questions/263400/what-is-the-best-algorithm-for-an-overridden-system-object-gethashcode36            if (xs == null)37            {38                return 82460653; // random number39            }40 41            unchecked42            {43                int hash = 41; // 41 is a random prime number44                foreach (T x in xs)45                {46                    hash *= 59; // 59 is a random prime number47                    if (x != null)48                    {49                        hash += x.GetHashCode();50                    }51                }52 53                return hash;54            }55        }56    }57 58    /// <summary>59    /// The type extension methods within this partial class are used/shared by both FullCLR and CoreCLR powershell.60    ///61    /// * If you want to add an extension method that will be used by both FullCLR and CoreCLR powershell, please add it here.62    /// * If you want to add an extension method that will be used only by CoreCLR powershell, please add it to the partial63    ///   'PSTypeExtensions' class in 'CorePsExtensions.cs'.64    /// </summary>65    internal static class PSTypeExtensions66    {67        /// <summary>68        /// Check does the type have an instance default constructor with visibility that allows calling it from subclass.69        /// </summary>70        /// <param name="type">Type.</param>71        /// <returns>True when type has a default ctor.</returns>72        internal static bool HasDefaultCtor(this Type type)73        {74            var ctor = type.GetConstructor(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, Type.EmptyTypes, null);75            if (ctor != null)76            {77                if (ctor.IsPublic || ctor.IsFamily || ctor.IsFamilyOrAssembly)78                {79                    return true;80                }81            }82 83            return false;84        }85 86        internal static bool IsNumeric(this Type type)87        {88            return LanguagePrimitives.IsNumeric(LanguagePrimitives.GetTypeCode(type));89        }90 91        internal static bool IsNumericOrPrimitive(this Type type)92        {93            return type.IsPrimitive || LanguagePrimitives.IsNumeric(LanguagePrimitives.GetTypeCode(type));94        }95 96        internal static bool IsSafePrimitive(this Type type)97        {98            return type.IsPrimitive && (type != typeof(IntPtr)) && (type != typeof(UIntPtr));99        }100 101        internal static bool IsFloating(this Type type)102        {103            return LanguagePrimitives.IsFloating(LanguagePrimitives.GetTypeCode(type));104        }105 106        internal static bool IsInteger(this Type type)107        {108            return LanguagePrimitives.IsInteger(LanguagePrimitives.GetTypeCode(type));109        }110 111        [MethodImpl(MethodImplOptions.AggressiveInlining)]112        internal static TypeCode GetTypeCode(this Type type)113        {114            return Type.GetTypeCode(type);115        }116 117        internal static IEnumerable<T> GetCustomAttributes<T>(this Type type, bool inherit)118            where T : Attribute119        {120            return from attr in type.GetCustomAttributes(typeof(T), inherit)121                   where attr is T122                   select (T)attr;123        }124    }125 126    internal static class WeakReferenceExtensions127    {128        internal static bool TryGetTarget<T>(this WeakReference weakReference, out T target) where T : class129        {130            var t = weakReference.Target;131            target = t as T;132            return (target != null);133        }134    }135}136