public void TestNullComparer_BuildComparer()
{
Random random = new Random();
// build a list of random dates
var dates = new List <DateTime>(getRandomDates(random));
// randomly choose which order to sort the components by
string[] propertyNames = { "Year", "Month", "Day", "Hour", "Minute", "Second" };
randomShuffle(propertyNames, random);
// build a comparer based on the order of the components
IComparer <DateTime> dateComparer = NullComparer <DateTime> .Default;
foreach (string propertyName in propertyNames)
{
string current = propertyName; // avoids non-local lambda problem
Func <DateTime, object> getter = (DateTime d) => typeof(DateTime).GetProperty(current).GetValue(d, null);
bool ascending = random.Next() % 2 == 0;
if (ascending)
{
dateComparer = dateComparer.ThenBy(getter);
}
else
{
dateComparer = dateComparer.ThenByDescending(getter);
}
}
// now we can sort the dates accordingly
dates.Sort(dateComparer);
}
/// <summary>
/// Returns a comparer that uses a key comparer if the source comparer determines the objects are equal.
/// </summary>
/// <typeparam name="T">The type of objects being compared.</typeparam>
/// <typeparam name="TKey">The type of key objects being compared.</typeparam>
/// <param name="source">The source comparer. If this is <c>null</c>, the default comparer is used.</param>
/// <param name="selector">The key selector. May not be <c>null</c>.</param>
/// <param name="comparerFactory">The definition of the key comparer. May not be <c>null</c>.</param>
/// <param name="specialNullHandling">A value indicating whether <c>null</c> values are passed to <paramref name="selector"/>. If <c>false</c>, then <c>null</c> values are considered less than any non-<c>null</c> values and are not passed to <paramref name="selector"/>. This value is ignored if <typeparamref name="T"/> is a non-nullable type.</param>
/// <param name="descending">A value indicating whether the sorting is done in descending order. If <c>false</c> (the default), then the sort is in ascending order.</param>
/// <returns>A comparer that uses a key comparer if the source comparer determines the objects are equal.</returns>
public static IFullComparer <T> ThenBy <T, TKey>(this IComparer <T>?source, Func <T, TKey> selector, Func <ComparerBuilderFor <TKey>, IComparer <TKey> > comparerFactory, bool specialNullHandling = false, bool descending = false)
{
_ = comparerFactory ?? throw new ArgumentNullException(nameof(comparerFactory));
var comparer = comparerFactory(ComparerBuilder.For <TKey>());
return(source.ThenBy(selector, comparer, specialNullHandling, descending));
}
public void ThenByWithProjection()
{
var data = SampleType.SampleData;
IComparer <SampleType> primary = ProjectionComparer <SampleType> .Create(t => t.First);
data.Sort(primary.ThenBy(t => t.Second));
Assert.IsTrue(new[] { 2, 10, 5 }.SequenceEqual(data.Select(x => x.Second)));
}
public void ThenByIsAppliedAsTieBreaker()
{
IComparer <Person> thenByComparer = ComparerBuilder.For <Person>().OrderBy(p => p.FirstName);
IComparer <Person> defaultComparer = ComparerBuilder.For <Person>().Default();
IComparer <Person> fullComparer = defaultComparer.ThenBy(thenByComparer);
Assert.True(defaultComparer.Compare(AbeAbrams, WilliamAbrams) == 0);
Assert.True(thenByComparer.Compare(AbeAbrams, WilliamAbrams) < 0);
Assert.True(fullComparer.Compare(AbeAbrams, WilliamAbrams) < 0);
}
private IComparer <DataRow> InsertOrderByType(IComparer <DataRow> orderBy)
{
if (orderBy == null || orderBy == OrderBy)
{
return(orderBy);
}
IComparer <DataRow> result = DataRow.OrderBy(_.Type, SortDirection.Ascending);
return(result.ThenBy(orderBy));
}
public void ThenByIsAppliedAsTieBreaker()
{
IComparer <Person> thenByComparer = Compare <string> .Default().SelectFrom((Person p) => p.FirstName);
IComparer <Person> defaultComparer = Compare <Person> .Default();
IComparer <Person> fullComparer = defaultComparer.ThenBy(thenByComparer);
Assert.IsTrue(defaultComparer.Compare(AbeAbrams, WilliamAbrams) == 0);
Assert.IsTrue(thenByComparer.Compare(AbeAbrams, WilliamAbrams) < 0);
Assert.IsTrue(fullComparer.Compare(AbeAbrams, WilliamAbrams) < 0);
}
public void SubstitutesCompareDefaultForNull()
{
IComparer <Person> thenByComparer = ComparerBuilder.For <Person>().OrderBy(p => p.FirstName);
IComparer <Person> source = null;
var comparer = source.ThenBy(thenByComparer);
Assert.Equal(ComparerBuilder.For <Person>().Default().ThenBy(thenByComparer).ToString(), comparer.ToString());
var list = new List <Person> {
AbeAbrams, WilliamAbrams, CaseyJohnson, JackAbrams
};
list.Sort(comparer);
Assert.Equal(new[] { AbeAbrams, JackAbrams, WilliamAbrams, CaseyJohnson }, list);
}
public void SubstitutesCompareDefaultForNull()
{
IComparer <Person> thenByComparer = Compare <string> .Default().SelectFrom((Person p) => p.FirstName);
IComparer <Person> source = null;
var comparer = source.ThenBy(thenByComparer);
Assert.AreSame(Compare <Person> .Default(), (comparer as CompoundComparer <Person>).Source);
var list = new List <Person> {
AbeAbrams, WilliamAbrams, CaseyJohnson, JackAbrams
};
list.Sort(comparer);
CollectionAssert.AreEqual(new[] { AbeAbrams, JackAbrams, WilliamAbrams, CaseyJohnson }, list);
}
/// <summary>
/// Returns a comparer that uses a key comparer if the source comparer determines the objects are equal.
/// </summary>
/// <typeparam name="T">The type of objects being compared.</typeparam>
/// <typeparam name="TKey">The type of key objects being compared.</typeparam>
/// <param name="source">The source comparer. If this is <c>null</c>, the default comparer is used.</param>
/// <param name="selector">The key selector. May not be <c>null</c>.</param>
/// <param name="keyComparer">The key comparer. Defaults to <c>null</c>. If this is <c>null</c>, the default comparer is used.</param>
/// <param name="specialNullHandling">A value indicating whether <c>null</c> values are passed to <paramref name="selector"/>. If <c>false</c>, then <c>null</c> values are considered less than any non-<c>null</c> values and are not passed to <paramref name="selector"/>. This value is ignored if <typeparamref name="T"/> is a non-nullable type.</param>
/// <param name="descending">A value indicating whether the sorting is done in descending order. If <c>false</c> (the default), then the sort is in ascending order.</param>
/// <returns>A comparer that uses a key comparer if the source comparer determines the objects are equal.</returns>
public static IFullComparer <T> ThenBy <T, TKey>(this IComparer <T> source, Func <T, TKey> selector, IComparer <TKey> keyComparer = null, bool specialNullHandling = false, bool descending = false)
{
var selectComparer = new SelectComparer <T, TKey>(selector, keyComparer, specialNullHandling);
return(source.ThenBy(selectComparer, descending));
}
protected override IComparer <UserOperation> GetUniqueComparer(IComparer <UserOperation> comparer) => comparer.ThenBy(CompareUserOperationsByHash.Instance);
protected override IComparer <MevBundle> GetGroupComparer(IComparer <MevBundle> comparer) //compares two bundles with same block # => comparer.ThenBy(CompareMevBundleByHash.Default);
public static IComparer <T> Prefer <T>(this IComparer <T> first, Predicate <T> test) => first.ThenBy(new TestComparer <T>(test));
protected override IComparer <MevBundle> GetUniqueComparer(IComparer <MevBundle> comparer) //compares all the bundles to evict the worst one => comparer.ThenBy(CompareMevBundleByHash.Default);
public static IComparer <Transaction> GetPoolUniqueTxComparer(this IComparer <Transaction> comparer) => comparer .ThenBy(ByHashTxComparer.Instance); // in order to sort properly and not lose transactions we need to differentiate on their identity which provided comparer might not be doing
/// <summary>
/// Returns a comparer that uses a key comparer if the source comparer determines the objects are equal.
/// </summary>
/// <typeparam name="T">The type of objects being compared.</typeparam>
/// <typeparam name="TKey">The type of key objects being compared.</typeparam>
/// <param name="source">The source comparer. If this is <c>null</c>, the default comparer is used.</param>
/// <param name="selector">The key selector. May not be <c>null</c>.</param>
/// <param name="comparerFactory">The definition of the key comparer. May not be <c>null</c>.</param>
/// <param name="specialNullHandling">A value indicating whether <c>null</c> values are passed to <paramref name="selector"/>. If <c>false</c>, then <c>null</c> values are considered less than any non-<c>null</c> values and are not passed to <paramref name="selector"/>. This value is ignored if <typeparamref name="T"/> is a non-nullable type.</param>
/// <param name="descending">A value indicating whether the sorting is done in descending order. If <c>false</c> (the default), then the sort is in ascending order.</param>
/// <returns>A comparer that uses a key comparer if the source comparer determines the objects are equal.</returns>
public static IFullComparer <T> ThenBy <T, TKey>(this IComparer <T> source, Func <T, TKey> selector, Func <ComparerBuilderFor <TKey>, IComparer <TKey> > comparerFactory, bool specialNullHandling = false, bool descending = false)
{
var comparer = comparerFactory(ComparerBuilder.For <TKey>());
return(source.ThenBy(selector, comparer, specialNullHandling, descending));
}
/// <summary>
/// Returns a comparer that uses a key comparer if the source comparer determines the objects are equal.
/// </summary>
/// <typeparam name="T">The type of objects being compared.</typeparam>
/// <typeparam name="TKey">The type of key objects being compared.</typeparam>
/// <param name="source">The source comparer. If this is <c>null</c>, the default comparer is used.</param>
/// <param name="selector">The key selector. May not be <c>null</c>.</param>
/// <param name="keyComparer">The key comparer. Defaults to <c>null</c>. If this is <c>null</c>, the default comparer is used.</param>
/// <param name="allowNulls">A value indicating whether <c>null</c> values are passed to <paramref name="selector"/>. If <c>false</c>, then <c>null</c> values are considered less than any non-<c>null</c> values and are not passed to <paramref name="selector"/>.</param>
/// <param name="descending">A value indicating whether the sorting is done in descending order. If <c>false</c> (the default), then the sort is in ascending order.</param>
/// <returns>A comparer that uses a key comparer if the source comparer determines the objects are equal.</returns>
public static IFullComparer <T> ThenBy <T, TKey>(this IComparer <T> source, Func <T, TKey> selector, IComparer <TKey> keyComparer = null, bool allowNulls = false, bool descending = false)
{
Contract.Requires(selector != null);
Contract.Ensures(Contract.Result <IFullComparer <T> >() != null);
return(source.ThenBy(keyComparer.SelectFrom(selector, allowNulls), descending));
}
internal static IComparer <Transaction> GetPoolUniqueTxComparer(IComparer <Transaction> comparer) => comparer .ThenBy(DistinctCompareTx.Instance); // in order to sort properly and not loose transactions we need to differentiate on their identity which provided comparer might not be doing
