MegaBites-AI/Windows-powershell

1// Copyright (c) Microsoft Corporation.2// Licensed under the MIT License.3 4using System.Collections.Generic;5using System.Text;6 7using Dbg = System.Management.Automation;8 9namespace System.Management.Automation10{11    /// <summary>12    /// Performs enum minimum disambiguation.13    /// </summary>14    internal static class EnumMinimumDisambiguation15    {16        #region Constructors17 18        /// <summary>19        /// Initialize the dictionary for special cases of minimum disambiguation.20        /// </summary>21        static EnumMinimumDisambiguation()22        {23            // Add special minimum disambiguation cases here for certain enum types.24            // The current implementation assumes that special names in each type can be25            // differentiated by their first letter.26            s_specialDisambiguateCases.Add(27                typeof(System.IO.FileAttributes),28                new string[] { "Directory", "ReadOnly", "System" });29        }30 31        #endregion32 33        /// <summary>34        /// Perform disambiguation on enum names.35        /// </summary>36        /// <returns>Complete enum name after disambiguation.</returns>37        internal static string EnumDisambiguate(string text, Type enumType)38        {39            // Get all enum names in the given enum type40            string[] enumNames = Enum.GetNames(enumType);41 42            // Get all names that matches the given prefix.43            List<string> namesWithMatchingPrefix = new List<string>();44            foreach (string name in enumNames)45            {46                if (name.StartsWith(text, StringComparison.OrdinalIgnoreCase))47                {48                    namesWithMatchingPrefix.Add(name);49                }50            }51 52            // Throw error when no match is found.53            if (namesWithMatchingPrefix.Count == 0)54            {55                throw InterpreterError.NewInterpreterException(null, typeof(RuntimeException),56                    null, "NoEnumNameMatch", EnumExpressionEvaluatorStrings.NoEnumNameMatch, text, EnumAllValues(enumType));57            }58            // Return the result if there is only one match.59            else if (namesWithMatchingPrefix.Count == 1)60            {61                return namesWithMatchingPrefix[0];62            }63            // multiple matches situation64            else65            {66                // test for exact match67                foreach (string matchName in namesWithMatchingPrefix)68                {69                    if (matchName.Equals(text, StringComparison.OrdinalIgnoreCase))70                    {71                        return matchName;72                    }73                }74                // test for special cases match75                string[] minDisambiguateNames;76                if (s_specialDisambiguateCases.TryGetValue(enumType, out minDisambiguateNames))77                {78                    foreach (string tName in minDisambiguateNames)79                    {80                        if (tName.StartsWith(text, StringComparison.OrdinalIgnoreCase))81                        {82                            return tName;83                        }84                    }85                }86                // No special cases match, throw error for multiple matches.87                StringBuilder matchListSB = new StringBuilder(namesWithMatchingPrefix[0]);88                const string separator = ", ";89                for (int i = 1; i < namesWithMatchingPrefix.Count; i++)90                {91                    matchListSB.Append(separator);92                    matchListSB.Append(namesWithMatchingPrefix[i]);93                }94 95                throw InterpreterError.NewInterpreterException(null, typeof(RuntimeException),96                    null, "MultipleEnumNameMatch", EnumExpressionEvaluatorStrings.MultipleEnumNameMatch,97                    text, matchListSB.ToString());98            }99        }100 101        /// <summary>102        /// Produces a string that contains all the enumerator names in an enum type.103        /// </summary>104        /// <param name="enumType"></param>105        /// <returns></returns>106        internal static string EnumAllValues(Type enumType)107        {108            string[] names = Enum.GetNames(enumType);109            const string separator = ", ";110            StringBuilder returnValue = new StringBuilder();111            if (names.Length != 0)112            {113                for (int i = 0; i < names.Length; i++)114                {115                    returnValue.Append(names[i]);116                    returnValue.Append(separator);117                }118 119                returnValue.Remove(returnValue.Length - separator.Length, separator.Length);120            }121 122            return returnValue.ToString();123        }124 125        private static readonly Dictionary<Type, string[]> s_specialDisambiguateCases = new Dictionary<Type, string[]>();126    }127}128