Oni2/OniSplit/Utils.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;
using System.Xml;
using System.Reflection;

namespace Oni
{
#if !NETFX4
    internal delegate void Action();
    internal delegate void Action<T>(T arg1);
    internal delegate void Action<T1, T2>(T1 arg1, T2 args);
    internal delegate TResult Func<T1, TResult>(T1 arg1);
    internal delegate TResult Func<T1, T2, TResult>(T1 arg1, T2 arg2);
    internal delegate TResult Func<T1, T2, T3, TResult>(T1 arg1, T2 arg2, T3 arg3);
#endif

    internal static class Utils
    {
        private static string version;

        public static string Version
        {
            get
            {
                if (version == null)
                {
#if NETCORE
                    version = typeof(Utils).GetTypeInfo().Assembly.GetName().Version.ToString();
#else
                    version = typeof(Utils).Assembly.GetName().Version.ToString();
#endif
                }

                return version;
            }
        }

        public static string TagToString(int tag)
        {
            var chars = new char[4];

            chars[0] = (char)((tag >> 00) & 0xff);
            chars[1] = (char)((tag >> 08) & 0xff);
            chars[2] = (char)((tag >> 16) & 0xff);
            chars[3] = (char)((tag >> 24) & 0xff);

            return new string(chars);
        }

        public static int Align4(int value) => (value + 0x03) & ~0x03;
        public static int Align32(int value) => (value + 0x1f) & ~0x1f;

        public static short ByteSwap(short value)
        {
            return (short)((value >> 8) | (value << 8));
        }

        public static int ByteSwap(int value)
        {
            value = (value >> 16) | (value << 16);
            return ((value >> 8) & 0x00ff00ff) | ((value & 0x00ff00ff) << 8);
        }

        public static bool ArrayEquals<T>(T[] a1, T[] a2)
        {
            if (a1 == a2)
                return true;

            if (a1 == null || a2 == null)
                return false;

            if (a1.Length != a2.Length)
                return false;

            var comparer = EqualityComparer<T>.Default;

            for (int i = 0; i < a1.Length; i++)
            {
                if (!comparer.Equals(a1[i], a2[i]))
                    return false;
            }

            return true;
        }

        public static string CleanupTextureName(string name)
        {
            name = name.Replace('/', '_');

            if (name == "<none>")
                name = "none";

            return name;
        }

        private static readonly char[] wildcards = { '*', '?', '.' };

        private static void WildcardToRegex(string wexp, StringBuilder regexp)
        {
            for (int startIndex = 0; startIndex < wexp.Length;)
            {
                int i = wexp.IndexOfAny(wildcards, startIndex);

                if (i == -1)
                {
                    regexp.Append(wexp, startIndex, wexp.Length - startIndex);
                    break;
                }

                regexp.Append(wexp, startIndex, i - startIndex);

                if (wexp[i] == '.')
                    regexp.Append("\\.");
                if (wexp[i] == '*')
                    regexp.Append(".*");
                else if (wexp[i] == '?')
                    regexp.Append('.');

                startIndex = i + 1;
            }
        }

        public static Regex WildcardToRegex(string wexp)
        {
            if (string.IsNullOrEmpty(wexp))
                return null;

            var regexp = new StringBuilder();
            WildcardToRegex(wexp, regexp);
            return new Regex(regexp.ToString(), RegexOptions.Singleline);
        }

        public static Regex WildcardToRegex(List<string> wexps)
        {
            if (wexps.Count == 0)
                return null;

            var regex = new StringBuilder();

            foreach (var wexp in wexps)
            {
                if (regex.Length != 0)
                    regex.Append('|');

                regex.Append('(');
                WildcardToRegex(wexp, regex);
                regex.Append(')');
            }

            Console.WriteLine(regex.ToString());

            return new Regex(regex.ToString(), RegexOptions.Singleline);
        }

        private static byte[] buffer1;
        private static byte[] buffer2;

        public static bool AreFilesEqual(string filePath1, string filePath2)
        {
            if (buffer1 == null)
            {
                buffer1 = new byte[32768];
                buffer2 = new byte[32768];
            }

            using (var s1 = File.OpenRead(filePath1))
            using (var s2 = File.OpenRead(filePath2))
            {
                if (s1.Length != s2.Length)
                    return false;

                while (true)
                {
                    int r1 = s1.Read(buffer1, 0, buffer1.Length);
                    int r2 = s2.Read(buffer2, 0, buffer2.Length);

                    if (r1 != r2)
                        return false;

                    if (r1 == 0)
                        return true;

                    for (int i = 0; i < r1; i++)
                    {
                        if (buffer1[i] != buffer2[i])
                            return false;
                    }
                }
            }
        }

        
        public static bool IsFlagsEnum(Type enumType)
        {
#if NETCORE
            return (enumType.GetTypeInfo().GetCustomAttributes(typeof(FlagsAttribute), false).Any());
#else
            return (enumType.GetCustomAttributes(typeof(FlagsAttribute), false).Length > 0);
#endif
        }

        public static void WriteEnum(Type enumType)
        {
            bool isFlags = IsFlagsEnum(enumType);
            Type underlyingType = Enum.GetUnderlyingType(enumType);

            if (isFlags)
                Console.WriteLine("flags {0}", enumType.Name);
            else
                Console.WriteLine("enum {0}", enumType.Name);

            foreach (string name in Enum.GetNames(enumType))
            {
                object value = Enum.Parse(enumType, name);

                if (isFlags)
                {
                    if (underlyingType == typeof(ulong))
                        Console.WriteLine("\t{0} = 0x{1:X16}", name, Convert.ToUInt64(value));
                    else
                        Console.WriteLine("\t{0} = 0x{1:X8}", name, Convert.ToUInt32(value));
                }
                else
                {
                    if (underlyingType == typeof(ulong))
                        Console.WriteLine("\t{0} = {1}", name, Convert.ToUInt64(value));
                    else
                        Console.WriteLine("\t{0} = {1}", name, Convert.ToInt32(value));
                }
            }

            Console.WriteLine();
        }

        public static IEnumerable<T> Reverse<T>(this IList<T> list)
        {
            for (int i = list.Count - 1; i >= 0; i--)
                yield return list[i];
        }

        public static T First<T>(this IList<T> list) => list[0];

        public static T Last<T>(this IList<T> list) => list[list.Count - 1];

        public static T LastOrDefault<T>(this List<T> list)
        {
            if (list.Count == 0)
                return default(T);

            return list[list.Count - 1];
        }

        public static float[] Negate(this float[] values)
        {
            float[] result = new float[values.Length];

            for (int i = 0; i < values.Length; i++)
                result[i] = -values[i];

            return result;
        }

        public static string CommonPrefix(List<string> strings)
        {
            string first = strings[0];

            for (int prefixLength = 0; prefixLength < first.Length; prefixLength++)
            {
                for (int i = 1; i < strings.Count; i++)
                {
                    string s = strings[i];

                    if (prefixLength >= s.Length || first[prefixLength] != s[prefixLength])
                        return first.Substring(0, prefixLength);
                }
            }

            return first;
        }

        public static void SkipSequence(this XmlReader xml, string name)
        {
            while (xml.IsStartElement(name))
                xml.Skip();
        }

        public static bool SkipEmpty(this XmlReader xml)
        {
            if (!xml.IsEmptyElement)
                return false;

            xml.Skip();
            return true;
        }

        //public static int CommonPrefixLength(string s1, string s2)
        //{
        //    int length = Math.Min(s1.Length, s2.Length);

        //    for (int i = 0; i < length; i++)
        //    {
        //        if (s1[i] != s2[i])
        //            return i;
        //    }

        //    return length;
        //}
    }

    /// <summary>
    /// A couple of IEnumerable extensions so we can run even on .NET 2.0
    /// </summary>
    internal static class Enumerable
    {
        public static bool Any<T>(this IEnumerable<T> source)
        {
            foreach (var t in source)
                return true;

            return false;
        }

        public static bool Any<T>(this IEnumerable<T> source, Func<T, bool> predicate)
        {
            foreach (var t in source)
            {
                if (predicate(t))
                    return true;
            }

            return false;
        }

        public static bool All<T>(this IEnumerable<T> source, Func<T, bool> predicate)
        {
            foreach (var t in source)
            {
                if (!predicate(t))
                    return false;
            }

            return true;
        }

        public static IEnumerable<T> OfType<T>(this System.Collections.IEnumerable source)
            where T : class
        {
            foreach (var obj in source)
            {
                var t = obj as T;

                if (t != null)
                    yield return t;
            }
        }

        public static IEnumerable<T> Distinct<T>(this IEnumerable<T> source)
            where T : class
        {
            var set = new Dictionary<T, bool>();
            bool hasNull = false;

            foreach (var t in source)
            {
                if (t == null)
                {
                    if (!hasNull)
                    {
                        hasNull = true;
                        yield return null;
                    }
                }
                else if (!set.ContainsKey(t))
                {
                    set.Add(t, true);
                    yield return t;
                }
            }
        }

        public static int Count<T>(this IEnumerable<T> source, Func<T, bool> predicate)
        {
            var count = 0;

            foreach (var t in source)
                if (predicate(t))
                    count++;

            return count;
        }

        public static IEnumerable<T> Concatenate<T>(this IEnumerable<T> first, IEnumerable<T> second)
        {
            foreach (var t in first)
                yield return t;

            foreach (var t in second)
                yield return t;
        }

        public static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> predicate)
        {
            foreach (var t in source)
            {
                if (predicate(t))
                    yield return t;
            }
        }

        public static bool IsEmpty<T>(this IEnumerable<T> source)
        {
            foreach (var t in source)
                return true;

            return false;
        }

        public static T First<T>(this IEnumerable<T> source)
        {
            foreach (var t in source)
                return t;

            throw new InvalidOperationException();
        }

        public static T First<T>(this IEnumerable<T> source, Func<T, bool> predicate)
        {
            foreach (var t in source)
            {
                if (predicate(t))
                    return t;
            }

            throw new InvalidOperationException();
        }

        public static T FirstOrDefault<T>(this IEnumerable<T> source)
        {
            foreach (var t in source)
                return t;

            return default(T);
        }

        public static T FirstOrDefault<T>(this IEnumerable<T> source, Func<T, bool> predicate)
        {
            foreach (var t in source)
            {
                if (predicate(t))
                    return t;
            }

            return default(T);
        }

        public static IEnumerable<TOut> Select<TIn, TOut>(this IEnumerable<TIn> source, Func<TIn, TOut> selector)
        {
            foreach (var t in source)
                yield return selector(t);
        }

        public static IEnumerable<TOut> SelectMany<TIn, TOut>(this IEnumerable<TIn> source, Func<TIn, IEnumerable<TOut>> selector)
        {
            foreach (var tin in source)
            {
                foreach (var tout in selector(tin))
                    yield return tout;
            }
        }

        public static float Max(this IEnumerable<float> source)
        {
            var max = float.MinValue;

            foreach (var value in source)
                max = Math.Max(max, value);

            return max;
        }

        public static float Min<T>(this IEnumerable<T> source, Func<T, float> selector)
        {
            var min = float.MaxValue;

            foreach (var value in source)
                min = Math.Min(min, selector(value));

            return min;
        }

        public static int Min<T>(this IEnumerable<T> source, Func<T, int> selector)
        {
            var min = int.MaxValue;

            foreach (var value in source)
                min = Math.Min(min, selector(value));

            return min;
        }

        public static float Min(this IEnumerable<float> source)
        {
            var min = float.MaxValue;

            foreach (var value in source)
                min = Math.Min(min, value);

            return min;
        }

        public static float Max<T>(this IEnumerable<T> source, Func<T, float> selector)
        {
            var max = float.MinValue;

            foreach (var value in source)
                max = Math.Max(max, selector(value));

            return max;
        }

        public static int Max(this IEnumerable<int> source)
        {
            int max = int.MinValue;

            foreach (var value in source)
            {
                if (value > max)
                    max = value;
            }

            return max;
        }

        public static int Max<T>(this IEnumerable<T> source, Func<T, int> selector)
        {
            int max = int.MinValue;

            foreach (var item in source)
            {
                var value = selector(item);

                if (value > max)
                    max = value;
            }

            return max;
        }

        public static TOutput[] ConvertAll<TInput, TOutput>(this TInput[] input, Func<TInput, TOutput> converter)
        {
            var output = new TOutput[input.Length];

            for (int i = 0; i < output.Length; i++)
                output[i] = converter(input[i]);

            return output;
        }

        public static int Sum<T>(this IEnumerable<T> source, Func<T, int> selector)
        {
            int sum = 0;

            foreach (var value in source)
                sum += selector(value);

            return sum;
        }

        public static IEnumerable<T> Repeat<T>(T value, int count)
        {
            for (int i = 0; i < count; i++)
                yield return value;
        }

        public static T[] ToArray<T>(this IEnumerable<T> source)
        {
            var collection = source as ICollection<T>;

            if (collection != null)
            {
                var result = new T[collection.Count];
                collection.CopyTo(result, 0);
                return result;
            }

            return new List<T>(source).ToArray();
        }

        public static List<T> ToList<T>(this IEnumerable<T> source) => new List<T>(source);

        public static IEnumerable<T> Ring<T>(this IEnumerable<T> source)
        {
            foreach (T t in source)
            {
                yield return t;
            }

            foreach (T t in source)
            {
                yield return t;
                break;
            }
        }

        public static IEnumerable<T> Skip<T>(this IEnumerable<T> source, int count)
        {
            foreach (T t in source)
            {
                if (count <= 0)
                    yield return t;

                count--;
            }
        }
    }

    internal struct EmptyArray<T>
    {
        public static readonly T[] Value = new T[0];
    }

    internal struct ReadOnlyArray<T>
    {
        private readonly T[] array;

        public ReadOnlyArray(T[] array)
        {
            this.array = array;
        }

        public int Length => array.Length;
        public T this[int index] => array[index];
    }

    internal class TreeIterator<T> : IEnumerable<T>
    {
        private readonly IEnumerable<T> roots;
        private readonly Func<T, IEnumerable<T>> children;

        public TreeIterator(IEnumerable<T> roots, Func<T, IEnumerable<T>> children)
        {
            this.roots = roots;
            this.children = children;
        }

        public class Enumerator : IEnumerator<T>
        {
            public bool MoveNext()
            {
                throw new NotImplementedException();
            }

            public T Current
            {
                get { throw new NotImplementedException(); }
            }

            object IEnumerator.Current => Current;

            public void Dispose()
            {
            }

            public void Reset()
            {
                throw new NotSupportedException();
            }
        }

        public IEnumerator<T> GetEnumerator() => new Enumerator();
        IEnumerator IEnumerable.GetEnumerator() => new Enumerator();
    }
}

#if !NETFX4
namespace System.Runtime.CompilerServices
{
    [AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
    internal sealed class ExtensionAttribute : Attribute
    {
    }
}
#endif
Revision:	1114
Committed:	Wed Jan 22 14:08:57 2020 UTC (5 years, 9 months ago) by iritscen
File size:	19216 byte(s)
Log Message:	Adding OniSplit source code (v0.9.99.0). Many thanks to Neo for all his work over the years.
#	Content
1	using System;
2	using System.Collections;
3	using System.Collections.Generic;
4	using System.IO;
5	using System.Text;
6	using System.Text.RegularExpressions;
7	using System.Xml;
8	using System.Reflection;
9
10	namespace Oni
11	{
12	#if !NETFX4
13	internal delegate void Action();
14	internal delegate void Action<T>(T arg1);
15	internal delegate void Action<T1, T2>(T1 arg1, T2 args);
16	internal delegate TResult Func<T1, TResult>(T1 arg1);
17	internal delegate TResult Func<T1, T2, TResult>(T1 arg1, T2 arg2);
18	internal delegate TResult Func<T1, T2, T3, TResult>(T1 arg1, T2 arg2, T3 arg3);
19	#endif
20
21	internal static class Utils
22	{
23	private static string version;
24
25	public static string Version
26	{
27	get
28	{
29	if (version == null)
30	{
31	#if NETCORE
32	version = typeof(Utils).GetTypeInfo().Assembly.GetName().Version.ToString();
33	#else
34	version = typeof(Utils).Assembly.GetName().Version.ToString();
35	#endif
36	}
37
38	return version;
39	}
40	}
41
42	public static string TagToString(int tag)
43	{
44	var chars = new char[4];
45
46	chars[0] = (char)((tag >> 00) & 0xff);
47	chars[1] = (char)((tag >> 08) & 0xff);
48	chars[2] = (char)((tag >> 16) & 0xff);
49	chars[3] = (char)((tag >> 24) & 0xff);
50
51	return new string(chars);
52	}
53
54	public static int Align4(int value) => (value + 0x03) & ~0x03;
55	public static int Align32(int value) => (value + 0x1f) & ~0x1f;
56
57	public static short ByteSwap(short value)
58	{
59	return (short)((value >> 8) \| (value << 8));
60	}
61
62	public static int ByteSwap(int value)
63	{
64	value = (value >> 16) \| (value << 16);
65	return ((value >> 8) & 0x00ff00ff) \| ((value & 0x00ff00ff) << 8);
66	}
67
68	public static bool ArrayEquals<T>(T[] a1, T[] a2)
69	{
70	if (a1 == a2)
71	return true;
72
73	if (a1 == null \|\| a2 == null)
74	return false;
75
76	if (a1.Length != a2.Length)
77	return false;
78
79	var comparer = EqualityComparer<T>.Default;
80
81	for (int i = 0; i < a1.Length; i++)
82	{
83	if (!comparer.Equals(a1[i], a2[i]))
84	return false;
85	}
86
87	return true;
88	}
89
90	public static string CleanupTextureName(string name)
91	{
92	name = name.Replace('/', '_');
93
94	if (name == "<none>")
95	name = "none";
96
97	return name;
98	}
99
100	private static readonly char[] wildcards = { '*', '?', '.' };
101
102	private static void WildcardToRegex(string wexp, StringBuilder regexp)
103	{
104	for (int startIndex = 0; startIndex < wexp.Length;)
105	{
106	int i = wexp.IndexOfAny(wildcards, startIndex);
107
108	if (i == -1)
109	{
110	regexp.Append(wexp, startIndex, wexp.Length - startIndex);
111	break;
112	}
113
114	regexp.Append(wexp, startIndex, i - startIndex);
115
116	if (wexp[i] == '.')
117	regexp.Append("\\.");
118	if (wexp[i] == '*')
119	regexp.Append(".*");
120	else if (wexp[i] == '?')
121	regexp.Append('.');
122
123	startIndex = i + 1;
124	}
125	}
126
127	public static Regex WildcardToRegex(string wexp)
128	{
129	if (string.IsNullOrEmpty(wexp))
130	return null;
131
132	var regexp = new StringBuilder();
133	WildcardToRegex(wexp, regexp);
134	return new Regex(regexp.ToString(), RegexOptions.Singleline);
135	}
136
137	public static Regex WildcardToRegex(List<string> wexps)
138	{
139	if (wexps.Count == 0)
140	return null;
141
142	var regex = new StringBuilder();
143
144	foreach (var wexp in wexps)
145	{
146	if (regex.Length != 0)
147	regex.Append('\|');
148
149	regex.Append('(');
150	WildcardToRegex(wexp, regex);
151	regex.Append(')');
152	}
153
154	Console.WriteLine(regex.ToString());
155
156	return new Regex(regex.ToString(), RegexOptions.Singleline);
157	}
158
159	private static byte[] buffer1;
160	private static byte[] buffer2;
161
162	public static bool AreFilesEqual(string filePath1, string filePath2)
163	{
164	if (buffer1 == null)
165	{
166	buffer1 = new byte[32768];
167	buffer2 = new byte[32768];
168	}
169
170	using (var s1 = File.OpenRead(filePath1))
171	using (var s2 = File.OpenRead(filePath2))
172	{
173	if (s1.Length != s2.Length)
174	return false;
175
176	while (true)
177	{
178	int r1 = s1.Read(buffer1, 0, buffer1.Length);
179	int r2 = s2.Read(buffer2, 0, buffer2.Length);
180
181	if (r1 != r2)
182	return false;
183
184	if (r1 == 0)
185	return true;
186
187	for (int i = 0; i < r1; i++)
188	{
189	if (buffer1[i] != buffer2[i])
190	return false;
191	}
192	}
193	}
194	}
195
196
197	public static bool IsFlagsEnum(Type enumType)
198	{
199	#if NETCORE
200	return (enumType.GetTypeInfo().GetCustomAttributes(typeof(FlagsAttribute), false).Any());
201	#else
202	return (enumType.GetCustomAttributes(typeof(FlagsAttribute), false).Length > 0);
203	#endif
204	}
205
206	public static void WriteEnum(Type enumType)
207	{
208	bool isFlags = IsFlagsEnum(enumType);
209	Type underlyingType = Enum.GetUnderlyingType(enumType);
210
211	if (isFlags)
212	Console.WriteLine("flags {0}", enumType.Name);
213	else
214	Console.WriteLine("enum {0}", enumType.Name);
215
216	foreach (string name in Enum.GetNames(enumType))
217	{
218	object value = Enum.Parse(enumType, name);
219
220	if (isFlags)
221	{
222	if (underlyingType == typeof(ulong))
223	Console.WriteLine("\t{0} = 0x{1:X16}", name, Convert.ToUInt64(value));
224	else
225	Console.WriteLine("\t{0} = 0x{1:X8}", name, Convert.ToUInt32(value));
226	}
227	else
228	{
229	if (underlyingType == typeof(ulong))
230	Console.WriteLine("\t{0} = {1}", name, Convert.ToUInt64(value));
231	else
232	Console.WriteLine("\t{0} = {1}", name, Convert.ToInt32(value));
233	}
234	}
235
236	Console.WriteLine();
237	}
238
239	public static IEnumerable<T> Reverse<T>(this IList<T> list)
240	{
241	for (int i = list.Count - 1; i >= 0; i--)
242	yield return list[i];
243	}
244
245	public static T First<T>(this IList<T> list) => list[0];
246
247	public static T Last<T>(this IList<T> list) => list[list.Count - 1];
248
249	public static T LastOrDefault<T>(this List<T> list)
250	{
251	if (list.Count == 0)
252	return default(T);
253
254	return list[list.Count - 1];
255	}
256
257	public static float[] Negate(this float[] values)
258	{
259	float[] result = new float[values.Length];
260
261	for (int i = 0; i < values.Length; i++)
262	result[i] = -values[i];
263
264	return result;
265	}
266
267	public static string CommonPrefix(List<string> strings)
268	{
269	string first = strings[0];
270
271	for (int prefixLength = 0; prefixLength < first.Length; prefixLength++)
272	{
273	for (int i = 1; i < strings.Count; i++)
274	{
275	string s = strings[i];
276
277	if (prefixLength >= s.Length \|\| first[prefixLength] != s[prefixLength])
278	return first.Substring(0, prefixLength);
279	}
280	}
281
282	return first;
283	}
284
285	public static void SkipSequence(this XmlReader xml, string name)
286	{
287	while (xml.IsStartElement(name))
288	xml.Skip();
289	}
290
291	public static bool SkipEmpty(this XmlReader xml)
292	{
293	if (!xml.IsEmptyElement)
294	return false;
295
296	xml.Skip();
297	return true;
298	}
299
300	//public static int CommonPrefixLength(string s1, string s2)
301	//{
302	// int length = Math.Min(s1.Length, s2.Length);
303
304	// for (int i = 0; i < length; i++)
305	// {
306	// if (s1[i] != s2[i])
307	// return i;
308	// }
309
310	// return length;
311	//}
312	}
313
314	/// <summary>
315	/// A couple of IEnumerable extensions so we can run even on .NET 2.0
316	/// </summary>
317	internal static class Enumerable
318	{
319	public static bool Any<T>(this IEnumerable<T> source)
320	{
321	foreach (var t in source)
322	return true;
323
324	return false;
325	}
326
327	public static bool Any<T>(this IEnumerable<T> source, Func<T, bool> predicate)
328	{
329	foreach (var t in source)
330	{
331	if (predicate(t))
332	return true;
333	}
334
335	return false;
336	}
337
338	public static bool All<T>(this IEnumerable<T> source, Func<T, bool> predicate)
339	{
340	foreach (var t in source)
341	{
342	if (!predicate(t))
343	return false;
344	}
345
346	return true;
347	}
348
349	public static IEnumerable<T> OfType<T>(this System.Collections.IEnumerable source)
350	where T : class
351	{
352	foreach (var obj in source)
353	{
354	var t = obj as T;
355
356	if (t != null)
357	yield return t;
358	}
359	}
360
361	public static IEnumerable<T> Distinct<T>(this IEnumerable<T> source)
362	where T : class
363	{
364	var set = new Dictionary<T, bool>();
365	bool hasNull = false;
366
367	foreach (var t in source)
368	{
369	if (t == null)
370	{
371	if (!hasNull)
372	{
373	hasNull = true;
374	yield return null;
375	}
376	}
377	else if (!set.ContainsKey(t))
378	{
379	set.Add(t, true);
380	yield return t;
381	}
382	}
383	}
384
385	public static int Count<T>(this IEnumerable<T> source, Func<T, bool> predicate)
386	{
387	var count = 0;
388
389	foreach (var t in source)
390	if (predicate(t))
391	count++;
392
393	return count;
394	}
395
396	public static IEnumerable<T> Concatenate<T>(this IEnumerable<T> first, IEnumerable<T> second)
397	{
398	foreach (var t in first)
399	yield return t;
400
401	foreach (var t in second)
402	yield return t;
403	}
404
405	public static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> predicate)
406	{
407	foreach (var t in source)
408	{
409	if (predicate(t))
410	yield return t;
411	}
412	}
413
414	public static bool IsEmpty<T>(this IEnumerable<T> source)
415	{
416	foreach (var t in source)
417	return true;
418
419	return false;
420	}
421
422	public static T First<T>(this IEnumerable<T> source)
423	{
424	foreach (var t in source)
425	return t;
426
427	throw new InvalidOperationException();
428	}
429
430	public static T First<T>(this IEnumerable<T> source, Func<T, bool> predicate)
431	{
432	foreach (var t in source)
433	{
434	if (predicate(t))
435	return t;
436	}
437
438	throw new InvalidOperationException();
439	}
440
441	public static T FirstOrDefault<T>(this IEnumerable<T> source)
442	{
443	foreach (var t in source)
444	return t;
445
446	return default(T);
447	}
448
449	public static T FirstOrDefault<T>(this IEnumerable<T> source, Func<T, bool> predicate)
450	{
451	foreach (var t in source)
452	{
453	if (predicate(t))
454	return t;
455	}
456
457	return default(T);
458	}
459
460	public static IEnumerable<TOut> Select<TIn, TOut>(this IEnumerable<TIn> source, Func<TIn, TOut> selector)
461	{
462	foreach (var t in source)
463	yield return selector(t);
464	}
465
466	public static IEnumerable<TOut> SelectMany<TIn, TOut>(this IEnumerable<TIn> source, Func<TIn, IEnumerable<TOut>> selector)
467	{
468	foreach (var tin in source)
469	{
470	foreach (var tout in selector(tin))
471	yield return tout;
472	}
473	}
474
475	public static float Max(this IEnumerable<float> source)
476	{
477	var max = float.MinValue;
478
479	foreach (var value in source)
480	max = Math.Max(max, value);
481
482	return max;
483	}
484
485	public static float Min<T>(this IEnumerable<T> source, Func<T, float> selector)
486	{
487	var min = float.MaxValue;
488
489	foreach (var value in source)
490	min = Math.Min(min, selector(value));
491
492	return min;
493	}
494
495	public static int Min<T>(this IEnumerable<T> source, Func<T, int> selector)
496	{
497	var min = int.MaxValue;
498
499	foreach (var value in source)
500	min = Math.Min(min, selector(value));
501
502	return min;
503	}
504
505	public static float Min(this IEnumerable<float> source)
506	{
507	var min = float.MaxValue;
508
509	foreach (var value in source)
510	min = Math.Min(min, value);
511
512	return min;
513	}
514
515	public static float Max<T>(this IEnumerable<T> source, Func<T, float> selector)
516	{
517	var max = float.MinValue;
518
519	foreach (var value in source)
520	max = Math.Max(max, selector(value));
521
522	return max;
523	}
524
525	public static int Max(this IEnumerable<int> source)
526	{
527	int max = int.MinValue;
528
529	foreach (var value in source)
530	{
531	if (value > max)
532	max = value;
533	}
534
535	return max;
536	}
537
538	public static int Max<T>(this IEnumerable<T> source, Func<T, int> selector)
539	{
540	int max = int.MinValue;
541
542	foreach (var item in source)
543	{
544	var value = selector(item);
545
546	if (value > max)
547	max = value;
548	}
549
550	return max;
551	}
552
553	public static TOutput[] ConvertAll<TInput, TOutput>(this TInput[] input, Func<TInput, TOutput> converter)
554	{
555	var output = new TOutput[input.Length];
556
557	for (int i = 0; i < output.Length; i++)
558	output[i] = converter(input[i]);
559
560	return output;
561	}
562
563	public static int Sum<T>(this IEnumerable<T> source, Func<T, int> selector)
564	{
565	int sum = 0;
566
567	foreach (var value in source)
568	sum += selector(value);
569
570	return sum;
571	}
572
573	public static IEnumerable<T> Repeat<T>(T value, int count)
574	{
575	for (int i = 0; i < count; i++)
576	yield return value;
577	}
578
579	public static T[] ToArray<T>(this IEnumerable<T> source)
580	{
581	var collection = source as ICollection<T>;
582
583	if (collection != null)
584	{
585	var result = new T[collection.Count];
586	collection.CopyTo(result, 0);
587	return result;
588	}
589
590	return new List<T>(source).ToArray();
591	}
592
593	public static List<T> ToList<T>(this IEnumerable<T> source) => new List<T>(source);
594
595	public static IEnumerable<T> Ring<T>(this IEnumerable<T> source)
596	{
597	foreach (T t in source)
598	{
599	yield return t;
600	}
601
602	foreach (T t in source)
603	{
604	yield return t;
605	break;
606	}
607	}
608
609	public static IEnumerable<T> Skip<T>(this IEnumerable<T> source, int count)
610	{
611	foreach (T t in source)
612	{
613	if (count <= 0)
614	yield return t;
615
616	count--;
617	}
618	}
619	}
620
621	internal struct EmptyArray<T>
622	{
623	public static readonly T[] Value = new T[0];
624	}
625
626	internal struct ReadOnlyArray<T>
627	{
628	private readonly T[] array;
629
630	public ReadOnlyArray(T[] array)
631	{
632	this.array = array;
633	}
634
635	public int Length => array.Length;
636	public T this[int index] => array[index];
637	}
638
639	internal class TreeIterator<T> : IEnumerable<T>
640	{
641	private readonly IEnumerable<T> roots;
642	private readonly Func<T, IEnumerable<T>> children;
643
644	public TreeIterator(IEnumerable<T> roots, Func<T, IEnumerable<T>> children)
645	{
646	this.roots = roots;
647	this.children = children;
648	}
649
650	public class Enumerator : IEnumerator<T>
651	{
652	public bool MoveNext()
653	{
654	throw new NotImplementedException();
655	}
656
657	public T Current
658	{
659	get { throw new NotImplementedException(); }
660	}
661
662	object IEnumerator.Current => Current;
663
664	public void Dispose()
665	{
666	}
667
668	public void Reset()
669	{
670	throw new NotSupportedException();
671	}
672	}
673
674	public IEnumerator<T> GetEnumerator() => new Enumerator();
675	IEnumerator IEnumerable.GetEnumerator() => new Enumerator();
676	}
677	}
678
679	#if !NETFX4
680	namespace System.Runtime.CompilerServices
681	{
682	[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
683	internal sealed class ExtensionAttribute : Attribute
684	{
685	}
686	}
687	#endif