#region License
// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Reflection;
using System.Text;
using System.Collections;
using System.Linq;
using System.Globalization;
namespace Newtonsoft.Json.Utilities{
internal static class CollectionUtils
{
public static IEnumerable<T> CastValid<T>(this IEnumerable enumerable)
{
ValidationUtils.ArgumentNotNull(enumerable, "enumerable");
return enumerable.Cast<object>().Where(o => o is T).Cast<T>();
}
public static List<T> CreateList<T>(params T[] values)
{
return new List<T>(values);
}
/// <summary>
/// Determines whether the collection is null or empty.
/// </summary>
/// <param name="collection">The collection.</param>
/// <returns>
/// <c>true</c> if the collection is null or empty; otherwise, <c>false</c>.
/// </returns>
public static bool IsNullOrEmpty(ICollection collection)
{
if (collection != null)
{
return (collection.Count == 0);
}
return true;
}
/// <summary>
/// Determines whether the collection is null or empty.
/// </summary>
/// <param name="collection">The collection.</param>
/// <returns>
/// <c>true</c> if the collection is null or empty; otherwise, <c>false</c>.
/// </returns>
public static bool IsNullOrEmpty<T>(ICollection<T> collection)
{
if (collection != null)
{
return (collection.Count == 0);
}
return true;
}
/// <summary>
/// Determines whether the collection is null, empty or its contents are uninitialized values.
/// </summary>
/// <param name="list">The list.</param>
/// <returns>
/// <c>true</c> if the collection is null or empty or its contents are uninitialized values; otherwise, <c>false</c>.
/// </returns>
public static bool IsNullOrEmptyOrDefault<T>(IList<T> list)
{
if (IsNullOrEmpty<T>(list))
return true;
return ReflectionUtils.ItemsUnitializedValue<T>(list);
}
/// <summary>
/// Makes a slice of the specified list in between the start and end indexes.
/// </summary>
/// <param name="list">The list.</param>
/// <param name="start">The start index.</param>
/// <param name="end">The end index.</param>
/// <returns>A slice of the list.</returns>
public static IList<T> Slice<T>(IList<T> list, int? start, int? end)
{
return Slice<T>(list, start, end, null);
}
/// <summary>
/// Makes a slice of the specified list in between the start and end indexes,
/// getting every so many items based upon the step.
/// </summary>
/// <param name="list">The list.</param>
/// <param name="start">The start index.</param>
/// <param name="end">The end index.</param>
/// <param name="step">The step.</param>
/// <returns>A slice of the list.</returns>
public static IList<T> Slice<T>(IList<T> list, int? start, int? end, int? step)
{
if (list == null)
throw new ArgumentNullException("list");
if (step == 0)
throw new ArgumentException("Step cannot be zero.", "step");
List<T> slicedList = new List<T>();
// nothing to slice
if (list.Count == 0)
return slicedList;
// set defaults for null arguments
int s = step ?? 1;
int startIndex = start ?? 0;
int endIndex = end ?? list.Count;
// start from the end of the list if start is negitive
startIndex = (startIndex < 0) ? list.Count + startIndex : startIndex;
// end from the start of the list if end is negitive
endIndex = (endIndex < 0) ? list.Count + endIndex : endIndex;
// ensure indexes keep within collection bounds
startIndex = Math.Max(startIndex, 0);
endIndex = Math.Min(endIndex, list.Count - 1);
// loop between start and end indexes, incrementing by the step
for (int i = startIndex; i < endIndex; i += s)
{
slicedList.Add(list[i]);
}
return slicedList;
}
/// <summary>
/// Group the collection using a function which returns the key.
/// </summary>
/// <param name="source">The source collection to group.</param>
/// <param name="keySelector">The key selector.</param>
/// <returns>A Dictionary with each key relating to a list of objects in a list grouped under it.</returns>
public static Dictionary<K, List<V>> GroupBy<K, V>(ICollection<V> source, Func<V, K> keySelector)
{
if (keySelector == null)
throw new ArgumentNullException("keySelector");
Dictionary<K, List<V>> groupedValues = new Dictionary<K, List<V>>();
foreach (V value in source)
{
// using delegate to get the value's key
K key = keySelector(value);
List<V> groupedValueList;
// add a list for grouped values if the key is not already in Dictionary
if (!groupedValues.TryGetValue(key, out groupedValueList))
{
groupedValueList = new List<V>();
groupedValues.Add(key, groupedValueList);
}
groupedValueList.Add(value);
}
return groupedValues;
}
/// <summary>
/// Adds the elements of the specified collection to the specified generic IList.
/// </summary>
/// <param name="initial">The list to add to.</param>
/// <param name="collection">The collection of elements to add.</param>
public static void AddRange<T>(this IList<T> initial, IEnumerable<T> collection)
{
if (initial == null)
throw new ArgumentNullException("initial");
if (collection == null)
return;
foreach (T value in collection)
{
initial.Add(value);
}
}
public static void AddRange(this IList initial, IEnumerable collection)
{
ValidationUtils.ArgumentNotNull(initial, "initial");
ListWrapper<object> wrapper = new ListWrapper<object>(initial);
wrapper.AddRange(collection.Cast<object>());
}
public static List<T> Distinct<T>(List<T> collection)
{
List<T> distinctList = new List<T>();
foreach (T value in collection)
{
if (!distinctList.Contains(value))
distinctList.Add(value);
}
return distinctList;
}
public static List<List<T>> Flatten<T>(params IList<T>[] lists)
{
List<List<T>> flattened = new List<List<T>>();
Dictionary<int, T> currentList = new Dictionary<int, T>();
Recurse<T>(new List<IList<T>>(lists), 0, currentList, flattened);
return flattened;
}
private static void Recurse<T>(IList<IList<T>> global, int current, Dictionary<int, T> currentSet, List<List<T>> flattenedResult)
{
IList<T> currentArray = global[current];
for (int i = 0; i < currentArray.Count; i++)
{
currentSet[current] = currentArray[i];
if (current == global.Count - 1)
{
List<T> items = new List<T>();
for (int k = 0; k < currentSet.Count; k++)
{
items.Add(currentSet[k]);
}
flattenedResult.Add(items);
}
else
{
Recurse(global, current + 1, currentSet, flattenedResult);
}
}
}
public static List<T> CreateList<T>(ICollection collection)
{
if (collection == null)
throw new ArgumentNullException("collection");
T[] array = new T[collection.Count];
collection.CopyTo(array, 0);
return new List<T>(array);
}
public static bool ListEquals<T>(IList<T> a, IList<T> b)
{
if (a == null || b == null)
return (a == null && b == null);
if (a.Count != b.Count)
return false;
EqualityComparer<T> comparer = EqualityComparer<T>.Default;
for (int i = 0; i < a.Count; i++)
{
if (!comparer.Equals(a[i], b[i]))
return false;
}
return true;
}
#region GetSingleItem
public static bool TryGetSingleItem<T>(IList<T> list, out T value)
{
return TryGetSingleItem<T>(list, false, out value);
}
public static bool TryGetSingleItem<T>(IList<T> list, bool returnDefaultIfEmpty, out T value)
{
return MiscellaneousUtils.TryAction<T>(delegate { return GetSingleItem(list, returnDefaultIfEmpty); }, out value);
}
public static T GetSingleItem<T>(IList<T> list)
{
return GetSingleItem<T>(list, false);
}
public static T GetSingleItem<T>(IList<T> list, bool returnDefaultIfEmpty)
{
if (list.Count == 1)
return list[0];
else if (returnDefaultIfEmpty && list.Count == 0)
return default(T);
else
throw new Exception("Expected single {0} in list but got {1}.".FormatWith(CultureInfo.InvariantCulture, typeof(T), list.Count));
}
#endregion
public static IList<T> Minus<T>(IList<T> list, IList<T> minus)
{
ValidationUtils.ArgumentNotNull(list, "list");
List<T> result = new List<T>(list.Count);
foreach (T t in list)
{
if (minus == null || !minus.Contains(t))
result.Add(t);
}
return result;
}
public static IList CreateGenericList(Type listType)
{
ValidationUtils.ArgumentNotNull(listType, "listType");
return (IList)ReflectionUtils.CreateGeneric(typeof(List<>), listType);
}
public static IDictionary CreateGenericDictionary(Type keyType, Type valueType)
{
ValidationUtils.ArgumentNotNull(keyType, "keyType");
ValidationUtils.ArgumentNotNull(valueType, "valueType");
return (IDictionary)ReflectionUtils.CreateGeneric(typeof(Dictionary<,>), keyType, valueType);
}
public static bool IsListType(Type type)
{
ValidationUtils.ArgumentNotNull(type, "type");
if (type.IsArray)
return true;
if (typeof(IList).IsAssignableFrom(type))
return true;
if (ReflectionUtils.ImplementsGenericDefinition(type, typeof(IList<>)))
return true;
return false;
}
public static bool IsCollectionType(Type type)
{
ValidationUtils.ArgumentNotNull(type, "type");
if (type.IsArray)
return true;
if (typeof(ICollection).IsAssignableFrom(type))
return true;
if (ReflectionUtils.ImplementsGenericDefinition(type, typeof(ICollection<>)))
return true;
return false;
}
public static bool IsDictionaryType(Type type)
{
ValidationUtils.ArgumentNotNull(type, "type");
if (typeof(IDictionary).IsAssignableFrom(type))
return true;
if (ReflectionUtils.ImplementsGenericDefinition(type, typeof (IDictionary<,>)))
return true;
return false;
}
public static IWrappedCollection CreateCollectionWrapper(object list)
{
ValidationUtils.ArgumentNotNull(list, "list");
Type collectionDefinition;
if (ReflectionUtils.ImplementsGenericDefinition(list.GetType(), typeof(ICollection<>), out collectionDefinition))
{
Type collectionItemType = ReflectionUtils.GetCollectionItemType(collectionDefinition);
// Activator.CreateInstance throws AmbiguousMatchException. Manually invoke constructor
Func<Type, IList<object>, object> instanceCreator = (t, a) =>
{
ConstructorInfo c = t.GetConstructor(new[] { collectionDefinition });
return c.Invoke(new[] { list });
};
return (IWrappedCollection)ReflectionUtils.CreateGeneric(typeof(CollectionWrapper<>), new[] { collectionItemType }, instanceCreator, list);
}
else if (list is IList)
{
return new CollectionWrapper<object>((IList)list);
}
else
{
throw new Exception("Can not create ListWrapper for type {0}.".FormatWith(CultureInfo.InvariantCulture, list.GetType()));
}
}
public static IWrappedList CreateListWrapper(object list)
{
ValidationUtils.ArgumentNotNull(list, "list");
Type listDefinition;
if (ReflectionUtils.ImplementsGenericDefinition(list.GetType(), typeof(IList<>), out listDefinition))
{
Type collectionItemType = ReflectionUtils.GetCollectionItemType(listDefinition);
// Activator.CreateInstance throws AmbiguousMatchException. Manually invoke constructor
Func<Type, IList<object>, object> instanceCreator = (t, a) =>
{
ConstructorInfo c = t.GetConstructor(new[] {listDefinition});
return c.Invoke(new[] { list });
};
return (IWrappedList)ReflectionUtils.CreateGeneric(typeof(ListWrapper<>), new[] { collectionItemType }, instanceCreator, list);
}
else if (list is IList)
{
return new ListWrapper<object>((IList)list);
}
else
{
throw new Exception("Can not create ListWrapper for type {0}.".FormatWith(CultureInfo.InvariantCulture, list.GetType()));
}
}
public static IWrappedDictionary CreateDictionaryWrapper(object dictionary)
{
ValidationUtils.ArgumentNotNull(dictionary, "dictionary");
Type dictionaryDefinition;
if (ReflectionUtils.ImplementsGenericDefinition(dictionary.GetType(), typeof(IDictionary<,>), out dictionaryDefinition))
{
Type dictionaryKeyType = ReflectionUtils.GetDictionaryKeyType(dictionaryDefinition);
Type dictionaryValueType = ReflectionUtils.GetDictionaryValueType(dictionaryDefinition);
// Activator.CreateInstance throws AmbiguousMatchException. Manually invoke constructor
Func<Type, IList<object>, object> instanceCreator = (t, a) =>
{
ConstructorInfo c = t.GetConstructor(new[] { dictionaryDefinition });
return c.Invoke(new[] { dictionary });
};
return (IWrappedDictionary)ReflectionUtils.CreateGeneric(typeof(DictionaryWrapper<,>), new[] { dictionaryKeyType, dictionaryValueType }, instanceCreator, dictionary);
}
else if (dictionary is IDictionary)
{
return new DictionaryWrapper<object, object>((IDictionary)dictionary);
}
else
{
throw new Exception("Can not create DictionaryWrapper for type {0}.".FormatWith(CultureInfo.InvariantCulture, dictionary.GetType()));
}
}
public static object CreateAndPopulateList(Type listType, Action<IList, bool> populateList)
{
ValidationUtils.ArgumentNotNull(listType, "listType");
ValidationUtils.ArgumentNotNull(populateList, "populateList");
IList list;
Type collectionType;
bool isReadOnlyOrFixedSize = false;
if (listType.IsArray)
{
// have to use an arraylist when creating array
// there is no way to know the size until it is finised
list = new List<object>();
isReadOnlyOrFixedSize = true;
}
else if (ReflectionUtils.InheritsGenericDefinition(listType, typeof(ReadOnlyCollection<>), out collectionType))
{
Type readOnlyCollectionContentsType = collectionType.GetGenericArguments()[0];
Type genericEnumerable = ReflectionUtils.MakeGenericType(typeof(IEnumerable<>), readOnlyCollectionContentsType);
bool suitableConstructor = false;
foreach (ConstructorInfo constructor in listType.GetConstructors())
{
IList<ParameterInfo> parameters = constructor.GetParameters();
if (parameters.Count == 1)
{
if (genericEnumerable.IsAssignableFrom(parameters[0].ParameterType))
{
suitableConstructor = true;
break;
}
}
}
if (!suitableConstructor)
throw new Exception("Read-only type {0} does not have a public constructor that takes a type that implements {1}.".FormatWith(CultureInfo.InvariantCulture, listType, genericEnumerable));
// can't add or modify a readonly list
// use List<T> and convert once populated
list = CreateGenericList(readOnlyCollectionContentsType);
isReadOnlyOrFixedSize = true;
}
else if (typeof(IList).IsAssignableFrom(listType))
{
if (ReflectionUtils.IsInstantiatableType(listType))
list = (IList)Activator.CreateInstance(listType);
else if (listType == typeof(IList))
list = new List<object>();
else
list = null;
}
else if (ReflectionUtils.ImplementsGenericDefinition(listType, typeof(ICollection<>)))
{
if (ReflectionUtils.IsInstantiatableType(listType))
list = CreateCollectionWrapper(Activator.CreateInstance(listType));
else
list = null;
}
else
{
list = null;
}
if (list == null)
throw new Exception("Cannot create and populate list type {0}.".FormatWith(CultureInfo.InvariantCulture, listType));
populateList(list, isReadOnlyOrFixedSize);
// create readonly and fixed sized collections using the temporary list
if (isReadOnlyOrFixedSize)
{
if (listType.IsArray)
list = ToArray(((List<object>)list).ToArray(), ReflectionUtils.GetCollectionItemType(listType));
else if (ReflectionUtils.InheritsGenericDefinition(listType, typeof(ReadOnlyCollection<>)))
list = (IList)ReflectionUtils.CreateInstance(listType, list);
}
else if (list is IWrappedCollection)
{
return ((IWrappedCollection) list).UnderlyingCollection;
}
return list;
}
public static Array ToArray(Array initial, Type type)
{
if (type == null)
throw new ArgumentNullException("type");
Array destinationArray = Array.CreateInstance(type, initial.Length);
Array.Copy(initial, 0, destinationArray, 0, initial.Length);
return destinationArray;
}
public static bool AddDistinct<T>(this IList<T> list, T value)
{
return list.AddDistinct(value, EqualityComparer<T>.Default);
}
public static bool AddDistinct<T>(this IList<T> list, T value, IEqualityComparer<T> comparer)
{
if (list.ContainsValue(value, comparer))
return false;
list.Add(value);
return true;
}
// this is here because LINQ Bridge doesn't support Contains with IEqualityComparer<T>
public static bool ContainsValue<TSource>(this IEnumerable<TSource> source, TSource value, IEqualityComparer<TSource> comparer)
{
if (comparer == null)
comparer = EqualityComparer<TSource>.Default;
if (source == null)
throw new ArgumentNullException("source");
foreach (TSource local in source)
{
if (comparer.Equals(local, value))
return true;
}
return false;
}
public static bool AddRangeDistinct<T>(this IList<T> list, IEnumerable<T> values)
{
return list.AddRangeDistinct(values, EqualityComparer<T>.Default);
}
public static bool AddRangeDistinct<T>(this IList<T> list, IEnumerable<T> values, IEqualityComparer<T> comparer)
{
bool allAdded = true;
foreach (T value in values)
{
if (!list.AddDistinct(value, comparer))
allAdded = false;
}
return allAdded;
}
public static int IndexOf<T>(this IEnumerable<T> collection, Func<T, bool> predicate)
{
int index = 0;
foreach (T value in collection)
{
if (predicate(value))
return index;
index++;
}
return -1;
}
}
}
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