ref: 初步迁移部分枚举扩展

Extensions/Enumerable.cs

@@ -0,0 +1,142 @@
+using System;
+using System.Collections.Generic;
+
+namespace MeloongCore.Extensions {
+    public static class EnumerableExtensions {
+
+        /// <summary>
+        /// 去重。
+        /// </summary>
+        public static List<T> Distinct<T>(this IList<T> Arr, Func<T, T, bool> IsEqual) {
+            var ResultArray = new List<T>();
+            for (int i = 0; i <= Arr.Count - 1; i++) {
+                for (int ii = i + 1; ii <= Arr.Count - 1; ii++) {
+                    if (IsEqual(Arr[i], Arr[ii])) { goto NextElement; }
+                }
+                ResultArray.Add(Arr[i]);
+NextElement:;
+            }
+            return ResultArray;
+        }
+
+        /// <summary>
+        /// 判断这是否是仅有一个元素的集合。
+        /// </summary>
+        public static bool IsSingle<T>(this IEnumerable<T> Source) {
+            if (Source == null) {
+                return false;
+            } else if (Source is IList<T> list) {
+                return list.Count == 1;
+            } else {
+                using (var Enumerator = Source.GetEnumerator()) {
+                    if (!Enumerator.MoveNext()) { return false; }
+                    if (Enumerator.MoveNext()) { return false; }
+                    return true;
+                }
+            }
+        }
+
+        /// <summary>
+        /// 对集合的每个元素执行指定操作。
+        /// </summary>
+        public static IEnumerable<T> ForEach<T>(this IEnumerable<T> Collection, Action<T> Action) {
+            foreach (T Item in Collection) {
+                Action(Item);
+            }
+            return Collection;
+        }
+
+        /// <summary>
+        /// 选择所有最大值对应的对象。
+        /// 若没有元素则返回空列表。
+        /// </summary>
+        public static List<T> MaxByAll<T, C>(this IEnumerable<T> Source, Func<T, C> Selector) where C : IComparable<C> {
+            var Results = new List<T>();
+            using (var Enumerator = Source.GetEnumerator()) {
+                if (!Enumerator.MoveNext()) { return Results; }
+                T MaxItem = Enumerator.Current;
+                C MaxValue = Selector(MaxItem);
+                Results.Add(MaxItem);
+                while (Enumerator.MoveNext()) {
+                    T CurrentItem = Enumerator.Current;
+                    C CurrentValue = Selector(CurrentItem);
+                    int Comparison = CurrentValue.CompareTo(MaxValue);
+                    if (Comparison > 0) {
+                        MaxValue = CurrentValue;
+                        Results.Clear();
+                        Results.Add(CurrentItem);
+                    } else if (Comparison == 0) {
+                        Results.Add(CurrentItem);
+                    }
+                }
+            }
+            return Results;
+        }
+
+        /// <summary>
+        /// 选择所有最小值对应的对象。
+        /// 若没有元素则返回空列表。
+        /// </summary>
+        public static List<T> MinByAll<T, C>(this IEnumerable<T> List, Func<T, C> Selector) where C : IComparable<C> {
+            var Results = new List<T>();
+            using (var Enumerator = List.GetEnumerator()) {
+                if (!Enumerator.MoveNext()) { return Results; }
+                T MinItem = Enumerator.Current;
+                C MinValue = Selector(MinItem);
+                Results.Add(MinItem);
+                while (Enumerator.MoveNext()) {
+                    T CurrentItem = Enumerator.Current;
+                    C CurrentValue = Selector(CurrentItem);
+                    int Comparison = CurrentValue.CompareTo(MinValue);
+                    if (Comparison < 0) {
+                        MinValue = CurrentValue;
+                        Results.Clear();
+                        Results.Add(CurrentItem);
+                    } else if (Comparison == 0) {
+                        Results.Add(CurrentItem);
+                    }
+                }
+            }
+            return Results;
+        }
+
+        /// <summary>
+        /// 选择最大值对应的对象。
+        /// 若没有元素则返回 Nothing。
+        /// </summary>
+        public static T MaxBy<T, C>(this IEnumerable<T> Source, Func<T, C> Selector) where C : IComparable<C> {
+            using (var Enumerator = Source.GetEnumerator()) {
+                if (!Enumerator.MoveNext()) { return default(T); }
+                T MaxItem = Enumerator.Current;
+                C MaxValue = Selector(MaxItem);
+                while (Enumerator.MoveNext()) {
+                    C Value = Selector(Enumerator.Current);
+                    if (Value.CompareTo(MaxValue) <= 0) { continue; }
+                    MaxItem = Enumerator.Current;
+                    MaxValue = Value;
+                }
+                return MaxItem;
+            }
+        }
+
+        /// <summary>
+        /// 选择最小值对应的对象。
+        /// 若没有元素则返回 Nothing。
+        /// </summary>
+        public static T MinBy<T, C>(this IEnumerable<T> List, Func<T, C> Selector) where C : IComparable<C> {
+            using (var Enumerator = List.GetEnumerator()) {
+                if (!Enumerator.MoveNext()) { return default; }
+                T MinItem = Enumerator.Current;
+                C MinValue = Selector(MinItem);
+                while (Enumerator.MoveNext()) {
+                    C Value = Selector(Enumerator.Current);
+                    if (Value.CompareTo(MinValue) >= 0) { continue; }
+                    MinItem = Enumerator.Current;
+                    MinValue = Value;
+                }
+                return MinItem;
+            }
+        }
+
+    }
+}

General/Extensions.cs → Extensions/String.cs

@@ -1,10 +1,8 @@
 using System;
 using System.Runtime.CompilerServices;
 
-namespace MeloongCore {
-    public static class Extensions {
-
-        #region String
+namespace MeloongCore.Extensions {
+    public static class StringExtensions {
 
         /// <summary>
         /// 高速的 StartsWith。
@@ -28,7 +26,7 @@ namespace MeloongCore {
         /// </summary>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static bool ContainsIgnoreCase(this string value, string subString) {
-            return value.IndexOf(subString,StringComparison.OrdinalIgnoreCase) >= 0;
+            return value.IndexOf(subString, StringComparison.OrdinalIgnoreCase) >= 0;
         }
 
         /// <summary>
@@ -61,7 +59,5 @@ namespace MeloongCore {
             return value.LastIndexOf(subString, startIndex, ignoreCase ? StringComparison.OrdinalIgnoreCase : StringComparison.Ordinal);
         }
 
-        #endregion
-
     }
 }

General/PathUtils.cs

@@ -1,4 +1,5 @@
-using System.IO;
+using MeloongCore.Extensions;
+using System.IO;
 using System.Runtime.InteropServices;
 using System.Text;